Composite film and method for manufacturing the same

Abstract

To provide a laminated film with a high laminate property and with an excellent processability.SOLUTION: A laminated film includes a resin film (X) and a substrate (Y) with a function Z. The resin film (X) has a surface A and a surface B and there are at least an adhesion part and an air gap between the surface B and the substrate (Y). An adhesion force between the surface B and the substrate (Y) is 0.2 N / cm or more.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a composite film, a method for manufacturing the same, an interlayer film for laminated glass including the composite film, laminated glass including the interlayer film for laminated glass, and a roll formed by winding the composite film or the like.

Background Art

[0002] As glass for buildings or vehicles, laminated glass having a structure in which a pair of glass plates are adhered and integrated by an intermediate adhesive layer is known. Since icing or clouding occurs on this glass, as a method for removing it, a method of imparting conductivity to the laminated glass and removing it by energization has been proposed. Thus, there is a need for a technique for imparting functionality (for example, conductivity, heat ray shielding property, design property, light ray reflectivity, light ray absorptivity, etc.) to laminated glass.

[0003] As a method for manufacturing functional laminated glass, for example, a plastic film having such a function is sandwiched between two resin interlayer films, inserted between a pair of glass plates, and heat-sealed by the resin interlayer film by subjecting it to high-temperature and high-pressure treatment using an autoclave or the like. In this case, since a three-layer film is used, there is a concern about a decrease in productivity in the laminated glass manufacturing process. As a method for solving such a problem, Patent Document 1 describes handling it as a composite film in which a plastic film such as a resin interlayer film or a PET film is laminated in advance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, laminated glass formed using a composite film like that described in Patent Document 1 does not have sufficient lamination properties, and when exposed to high-temperature environments, surface defects such as air bubbles occur. On the other hand, if one attempts to improve lamination properties, the process passability decreases, and delamination between the resin interlayer and the plastic film becomes more likely while the composite film is being transported on rolls or the like. Thus, according to the inventors' research, lamination properties and process passability are inversely related, and it has been found that it is difficult to achieve both lamination properties and process passability at a high level.

[0006] Accordingly, the object of the present invention is to provide a composite film having high lamination properties and excellent process passability, a method for manufacturing the same, an interlayer for laminated glass containing the composite film, laminated glass containing the interlayer for laminated glass, and a roll on which the composite film, etc., is wound. [Means for solving the problem]

[0007] In order to solve the above problems, the inventors have conducted detailed studies on composite films comprising a resin film (X) and a substrate (Y) having function Z, and have completed the present invention. Specifically, the present invention includes the following preferred embodiments.

[0008] [1] A composite film comprising a resin film (X) and a substrate (Y) having function Z, wherein the resin film (X) has a surface A and a surface B, and at least an adhesive portion and a void exist between surface B and the substrate (Y), and the adhesion force between surface B and the substrate (Y) is 0.2 N / cm or more. [2] The composite film according to [1], wherein when a cross-section of the composite film along the width direction, over a 10 cm range in the central part of the width direction, is observed with a microscope, it has multiple adhesive parts and gaps with two adjacent adhesive parts at both ends, and more than 90% of all gaps have a width of 2.0 mm or less. [3] The composite film according to [1] or [2], wherein when a cross-section of the central 10 cm area along the width direction of the composite film is observed with a microscope, it has a plurality of adhesive parts and voids with two adjacent adhesive parts at both ends, and the average height of the voids is 0.1 μm or more and 50 μm or less. [4] The composite film according to any one of [1] to [3], comprising a substrate layer having a tensile storage modulus E'(40) of 0.1 GPa or more at 40°C, wherein the substrate (Y) is a substrate layer. [5] Formula (1): 10 <RzB×100 / RzA<140 (1) [In the formula, RzA represents the average value of the ten-point average roughness of surface A measured at any five locations in accordance with JIS B0601:1994, and RzB represents the average value of the ten-point average roughness of surface B measured at any five locations in accordance with JIS B0601:1994.] A composite film according to any of [1] to [4] that satisfies the following conditions. [6] The composite film according to any one of [1] to [5], wherein the adhesion force between surface B of the resin film (X) and the substrate (Y) is 1.3 N / cm or more. [7] The composite film according to any one of [1] to [6], wherein the substrate (Y) comprises at least one selected from the group consisting of polyvinyl acetal resin, ionomer resin, poly(meth)acrylic resin, polyolefin resin, and polycarbonate resin. [8] The composite film according to any one of [1] to [7], wherein the amount of plasticizer contained in the base material (Y) is 20% by mass or less. [9] A composite film according to any of [1] to [8], wherein the thickness of the substrate (Y) is 1 μm or more and 100 μm or less.

[10] The composite film according to any one of [1] to [9], wherein function Z is at least one selected from the group consisting of colorability, light absorption, light reflection, sound insulation, light scattering, luminescence, conductivity, double image prevention, and light transmission.

[11] A composite film according to any one of [1] to

[10] , wherein function Z is conductive, and the substrate (Y) comprises at least one selected from the group consisting of gold, silver, copper, metal oxides, organic conductive materials and carbon compounds.

[12] The composite film according to any one of [1] to

[11] , wherein function Z is conductive, and the substrate (Y) has a conductive structure formed by at least one method selected from the group consisting of etching, printing, coating and vapor deposition.

[13] A composite film as described in any of [1] to

[12] , wherein the average value RzA of the ten-point average roughness of surface A measured at any five locations in accordance with JIS B0601:1994 is 0.1 μm or more and 50 μm or less.

[14] A composite film as described in any of [1] to

[13] , wherein the average value RzB of the ten-point average roughness of surface B measured at any five locations in accordance with JIS B0601:1994 is 0.1 μm or more and 50 μm or less.

[15] A composite film as described in any of [1] to

[14] , wherein the average value of the ten-point average roughness measured at any five arbitrary locations on the surface of the substrate (Y) that is not in contact with the resin film (X), in accordance with JIS B0601:1994, is 0.1 μm or more and 20 μm or less.

[16] The composite film according to any one of [1] to

[15] , wherein the resin film (X) comprises a polyvinyl acetal resin and / or an ionomer resin.

[17] A composite film according to any one of [1] to

[16] , further comprising an adhesive layer (U), wherein the adhesive layer (U) is adjacent to a resin film (X) or a substrate (Y).

[18] A composite film according to any one of [1] to

[17] , wherein the base material (Y) is a base material comprising a base material layer (Y') and a functional layer having function Z, or a base material comprising a base material layer (Y") having function Z, and optionally comprising an adhesive layer (U), wherein the adhesive layer is U, the base material layer (Y') is Y', the base material layer (Y") is Y'', the functional layer having function Z is Z, and the resin film (X) is X, and the layers are laminated in the following order: X / Y", X / Z / Y', X / Z / Y' / U, X / Y' / Z, X / Y' / Z / U, X / Z / Y' / Z, / Z / Y', U / Z / Y' / X / Z / Y', U / Y' / Z / X / Z / Y' / U, U / Z / Y' / X / Z / Y' / U, Z / Y' / X / Y' / Z, U / Y' / Z / X / Y' / Z, U / Z / Y' / X / Y' / Z / U, Z / Y' / Z / X / Z / Y', Z / Y' / Z / X / Y' / Z, U / Z / Y' / Z / X / Z / Y', U / Z / Y' / Z / X / Y' / Z, U / Z / Y' / Z / X / Z / Y' / U, U / Z / Y' / Z / X / Y' / Z / U, Z / Y' / Z / X / Z / Y' / Z, U / Z / Y' / Z / X / Z / Y' / Z, U / Z / Y' / Z / X / Z / Y' / Z / U, and layer configurations in which two or more of these are stacked via X A composite film having any of the following: An interlayer for laminated glass, comprising a composite film as described in any of

[19] [1] to

[18] . Laminated glass in which the interlayer for laminated glass described in

[20]

[19] is sandwiched between two or more sheets of glass. A roll made by winding one of the composite films described in

[21] [1] to

[18] . A roll in which a composite film described in any of

[22] [1] to

[18] is wound together with a laminating sheet or an anti-blocking film. A method for manufacturing a composite film according to any one of

[23] [1] to

[18] , comprising a thermocompression step of passing a raw material composite film, which is made by layering at least a resin film (X) and a substrate (Y) having function Z, between a first roll and a second roll in an orientation such that the resin film (X) is closer to the first roll than the substrate (Y), wherein formula (2); 20 <T1-T2<140 (2) [In the formula, T1 represents the surface temperature (°C) of the first roll, and T2 represents the surface temperature (°C) of the second roll.] A method to satisfy the requirements.

[24] The method according to

[23] , wherein in the heat-sealing process, when the raw material composite film passes between the first roll and the second roll, it is pressurized with a linear pressure of 0.01 MPa or more and less than 2.0 MPa. [Advantages of the Invention

[0009] The composite film of the present invention has high laminating properties and excellent process passing properties. Therefore, it can be suitably used as a resin interlayer film capable of imparting functionality to laminated glass. [Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is a photograph obtained by observing a cross-section obtained by cutting the composite film according to an embodiment of the present invention along the width direction with a microscope. [Figure 2] FIG. 2 is an enlarged photograph of a void portion in a photograph obtained by observing a cross-section obtained by cutting the composite film according to an embodiment of the present invention along the width direction with a microscope. [Modes for Carrying Out the Invention

[0011] [Composite Film The composite film of the present invention includes a resin film (X) and a base material (Y) having a function Z. The resin film (X) has a surface A and a surface B, and at least an adhesion part and a void exist between the surface B and the base material (Y), and the adhesion force between the surface B and the base material (Y) is 0.2 N / cm or more.

[0012] The inventor has found that, in a composite film including a resin film (X) and a base material (Y) having a function Z, by providing at least an adhesion part and a void between the surface B and the base material (Y) and adjusting the adhesion force between the surface B and the base material (Y) to 0.2 N / cm or more, surprisingly, it is possible to achieve both high laminating properties during the production of laminated glass and excellent process passing properties. Specifically, the composite film of the present invention has high laminating properties during the production of laminated glass. Therefore, even when laminated glass made using this composite film is exposed to high-temperature environments, the occurrence of appearance defects such as air bubbles can be effectively suppressed. Furthermore, it has excellent processability, which prevents delamination between the resin film (X) and the substrate (Y) during the manufacturing process of the composite film. This is presumed to be because, during the production of laminated glass, high degassing performance can be achieved between the glass and the composite film due to predetermined voids, and at the adhesion area, an adhesion force of a predetermined value or higher is applied between surface B and the substrate (Y), thereby improving delamination resistance during the manufacturing process.

[0013] <Substrate (Y) having function Z> The composite film of the present invention includes a substrate (Y) having function Z (sometimes simply referred to as substrate (Y)). The substrate (Y) is not particularly limited as long as it has function Z, and may be a single layer or a laminate. The substrate (Y) preferably includes a substrate layer, and if it is a single layer, it preferably consists of a substrate layer, and if it is a laminate, it preferably includes a substrate layer and other layers. The substrate (Y) may contain one substrate layer and one other layer, or two or more of each.

[0014] In one embodiment of the present invention, when the substrate (Y) consists of a substrate layer, preferably the substrate layer has function Z. Furthermore, when the substrate (Y) comprises a substrate layer and other layers, the substrate layer may have function Z, the other layers may have function Z, or both may have function Z. In this specification, when the substrate layer has function Z, it is referred to as a substrate layer having function Z, and when the other layers have function Z, it is referred to as a functional layer having function Z, simply a functional layer, or a Z layer. From the viewpoint of easily imparting various functions Z to the substrate (Y), it is preferable to impart function Z to the substrate (Y) by providing at least a Z layer to the substrate (Y). Function Z can be imparted to the substrate (Y) by selecting the type of resin or additive contained in the substrate (Y), or by providing a Z layer, etc.

[0015] The base material (Y) (preferably the base material layer) preferably contains a resin. The resin contained in the base material (Y) is not particularly limited, but examples include polyvinyl acetal resin, ionomer resin, poly(meth)acrylic resin, polyolefin resin, polycarbonate resin, polyvinyl alcohol resin, polythiocarbonate resin, polyester resin, polyacetal resin, polyamide resin, polyimide resin, polyamideimide resin, polyetherimide resin, polyacrylonitrile resin, polyphenylene ether resin, polysulfone resin, polyphenylene sulfide resin, polyetherketone resin, thermoplastic elastomer, phenol resin, amino resin, furan resin, epoxy resin, polyurethane resin, silicone resin, diallyl phthalate resin, vinyl ester resin, aniline resin, acetone-formaldehyde resin, alkyd resin, maleimide resin, maleimide-cyanate ester resin, cyanate ester resin, benzoxazine resin, polybenzimidazole resin, polycarbodiimide resin, styrene resin, rubber resin, fluororesin, and the like. Among these, thermoplastic resins are preferred from the viewpoint of easily improving lamination and process passability, and at least one selected from the group consisting of polyvinyl acetal resin, ionomer resin, poly(meth)acrylic resin, polyolefin resin, and polycarbonate resin is more preferred, with polyvinyl acetal resin being even more preferred. The substrate (Y) may contain these resins individually or in combination of two or more. Note that poly(meth)acrylic resin refers to polyacrylic resin or polymethacrylic resin.

[0016] Examples of function Z include colorability, light absorption (e.g., UV absorption, infrared absorption, electromagnetic wave absorption), light reflectivity (e.g., infrared reflectivity, electromagnetic wave reflectivity), sound insulation, light scattering, luminescence, conductivity, double image prevention, and light transmission (e.g., infrared transmission, electromagnetic wave transmission). It is preferable that function Z is at least one selected from the group consisting of colorability, light absorption, light reflectivity, sound insulation, light scattering, luminescence, conductivity, double image prevention, and light transmission, and more preferably at least one selected from the group consisting of light absorption and conductivity. Function Z may consist of two or more different functions.

[0017] In a preferred embodiment of the present invention, the substrate (Y) (preferably the substrate layer) contains a polyvinyl acetal resin. By including a polyvinyl acetal resin in the substrate (Y), the adhesion between surface B and the substrate (Y) can be increased even when heat-pressed under relatively mild conditions, making it easier to maintain the void between surface B and the substrate (Y) after heat-pressing. As a result, it is easier to improve the lamination properties during the production of laminated glass while improving process passability, and it is easier to effectively suppress the occurrence of appearance defects such as bubbles even when the resulting laminated glass is exposed to a high-temperature environment.

[0018] Polyvinyl acetal resin is a resin produced by acetalizing polyvinyl alcohol-based resins such as polyvinyl alcohol or ethylene vinyl alcohol copolymer.

[0019] In a preferred embodiment of the present invention, the base material (Y) may contain one polyvinyl acetal resin, or it may contain two or more polyvinyl acetal resins in which one or more of the following are different: viscosity-average degree of polymerization, degree of acetalization, content of vinyl acetate units, content of alcohol units, ethylene content, molecular weight of the aldehyde used for acetalization, and chain length.

[0020] Polyvinyl acetal resin can be produced by, for example, the following method, but is not limited to this. First, an aqueous solution of polyvinyl alcohol or ethylene vinyl alcohol copolymer at a concentration of 3 to 30% by mass is held at a temperature range of 80 to 100°C and then gradually cooled over 10 to 60 minutes. When the temperature has dropped to -10 to 30°C, an aldehyde and an acid catalyst are added, and the acetalization reaction is carried out for 30 to 300 minutes while maintaining a constant temperature. Next, the reaction solution is heated to a temperature of 20 to 80°C over 30 to 200 minutes and held at that temperature for 30 to 300 minutes. After that, the reaction solution is filtered as necessary, neutralized with the addition of a neutralizing agent such as an alkali, and the resin is filtered, washed with water, and dried to produce polyvinyl acetal resin.

[0021] The acid catalyst used in the acetalization reaction is not particularly limited, and both organic and inorganic acids can be used. Examples of such acid catalysts include acetic acid, p-toluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid. Among these, hydrochloric acid, sulfuric acid, and nitric acid are preferred from the viewpoint of acid strength and ease of removal during washing.

[0022] From the viewpoint of easily obtaining a polyvinyl acetal resin having a suitable breaking energy, the aldehyde or keto compound used in the production of the polyvinyl acetal resin is preferably linear, branched, or cyclic, having 2 to 10 carbon atoms, and more preferably linear or branched. This results in a corresponding linear or branched acetal group. Alternatively, the polyvinyl acetal resin may be obtained by acetalizing polyvinyl alcohol or ethylene vinyl alcohol copolymer with a mixture of multiple aldehyde or keto compounds.

[0023] The polyvinyl acetal resin is preferably produced by the reaction of at least one polyvinyl alcohol with one or more aliphatic unbranched aldehydes having 2 to 10 carbon atoms. From the viewpoint of easily obtaining a polyvinyl acetal resin with a suitable fracture energy, n-butyraldehyde is preferred as such an aldehyde. The content of n-butyraldehyde in the aldehyde used for acetalization is preferably 50% by mass or more, more preferably 80% by mass or more, even more preferably 95% by mass or more, particularly preferably 99% by mass or more, and may also be 100% by mass.

[0024] The polyvinyl alcohol or ethylene vinyl alcohol copolymer used to produce polyvinyl acetal resin may be a single material or a mixture of polyvinyl alcohol or ethylene vinyl alcohol copolymers with different viscosity-average degrees of polymerization or degrees of hydrolysis.

[0025] The viscosity-average degree of polymerization of polyvinyl alcohol, which is the raw material for polyvinyl acetal resin, is preferably 100 or higher, more preferably 300 or higher, even more preferably 400 or higher, even more preferably 600 or higher, particularly preferably 700 or higher, and extremely preferably 750 or higher. When the viscosity-average degree of polymerization of polyvinyl alcohol is above the lower limit above, deformation and disconnection of the functional layer during the production of laminated glass are easily suppressed, and the phenomenon of glass shifting due to heat in the resulting laminated glass is easily prevented. Furthermore, the viscosity-average degree of polymerization of polyvinyl alcohol is preferably 5000 or lower, more preferably 3000 or lower, even more preferably 2500 or lower, particularly preferably 2300 or lower, and extremely preferably 2000 or lower. When the viscosity-average degree of polymerization of polyvinyl alcohol is below the upper limit above, good film-forming properties are easily obtained. Furthermore, when the viscosity-average degree of polymerization is below the upper limit above, laminating properties and process passability are easily improved. The viscosity-average degree of polymerization of polyvinyl alcohol can be measured, for example, according to JIS K 6726 "Test Method for Polyvinyl Alcohol". Commercially available polyvinyl alcohol resin may also be used.

[0026] The preferred lower and upper limits for the viscosity-average degree of polymerization of polyvinyl acetal resin are the same as the preferred lower and upper limits for the viscosity-average degree of polymerization of polyvinyl alcohol described above. When the substrate (Y) contains two or more polyvinyl acetal resins with different substrates, it is preferable that the viscosity-average degree of polymerization of at least one polyvinyl acetal resin is above the lower limit and below the upper limit. The viscosity-average degree of polymerization of polyvinyl acetal resin can be determined, for example, by JIS K6728 (1977) "Test method for polyvinyl butyral".

[0027] The content of vinyl acetate units (also called acetyl group content) in polyvinyl acetal resin is preferably 0.1 to 20 mol%, more preferably 0.5 to 3 mol% (e.g., 1 mol% or less) or 5 to 8 mol%, based on the ethylene units of the main chain of the polyvinyl acetal resin. The content of vinyl acetate units can be adjusted to the above range by appropriately adjusting the degree of saponification of the raw material polyvinyl alcohol-based resin. The content of vinyl acetate units affects the polarity of the polyvinyl acetal resin, which can change the plasticizer compatibility and mechanical strength of the polyvinyl acetal resin film. When the content of vinyl acetate units is within the above range, it is easier to improve the adhesion between the substrate (Y) and the resin film (X), and to achieve a reduction in optical distortion, etc. When the substrate (Y) contains two or more different polyvinyl acetal resins, it is preferable that the content of vinyl acetate units in at least one of the polyvinyl acetal resins is within the above range. In this specification, "based on the ethylene units of the main chain of the polyvinyl acetal resin" means the content of the target constituent unit in all constituent units, when a unit consisting of two carbon atoms in the main chain of polyvinyl alcohol, which is the raw material for the production of polyvinyl acetal resin (for example, a vinyl alcohol unit, a vinyl acetate unit, an ethylene unit, etc.) is considered as one constituent unit. By appropriately adjusting the degree of saponification of the raw material polyvinyl alcohol-based resin, the amount of vinyl acetate units (acetyl group amount) can be adjusted to within the above range.

[0028] In one embodiment of the present invention, the degree of acetalization of the polyvinyl acetal resin is not particularly limited. The degree of acetalization is preferably 40 mol% or more, more preferably 45 mol% or more, even more preferably 50 mol% or more, even more preferably 60 mol% or more, particularly preferably 68 mol% or more, preferably 86 mol% or less, more preferably 84 mol% or less, and even more preferably 82 mol% or less. By appropriately adjusting the amount of aldehyde used when acetalizing the polyvinyl alcohol resin, the degree of acetalization of the polyvinyl acetal resin can be adjusted to the above range. When the degree of acetalization is within the above range, the mechanical strength of the substrate (Y) tends to be sufficient. In addition, the lamination properties and process passability of the composite film tend to be improved. When the substrate (Y) contains two or more different polyvinyl acetal resins, it is preferable that the degree of acetalization of at least one polyvinyl acetal resin is within the above range.

[0029] In one embodiment of the present invention, the content of vinyl alcohol units in the polyvinyl acetal resin is preferably 6 to 26% by mass, more preferably 12 to 24% by mass, even more preferably 15 to 22% by mass, and even more preferably 18 to 21% by mass, based on the mass of ethylene units in the main chain of the polyvinyl acetal resin. Furthermore, the content of vinyl alcohol units in the polyvinyl acetal resin is preferably 9 to 36 mol%, more preferably 18 to 34 mol%, even more preferably 22 to 34 mol%, even more preferably 26 to 34 mol%, particularly preferably 26 to 31 mol%, and most preferably 26 to 30 mol%, based on the ethylene units in the main chain of the polyvinyl acetal resin. When the content of vinyl alcohol units is within the above range, if the resin film (X) or the adhesive layer (U) described later is a plasticized polyvinyl acetal resin layer, the refractive index difference between the plasticized polyvinyl acetal resin layer and the substrate (Y) becomes smaller, making it easier to obtain laminated glass with less optical unevenness. On the other hand, when further sound insulation performance is to be imparted to the base material (Y), the content of vinyl alcohol units in the polyvinyl acetal resin is preferably 6 to 20% by mass, more preferably 8 to 18% by mass, even more preferably 10 to 15% by mass, and particularly preferably 11 to 13% by mass, based on the mass of ethylene units in the main chain of the polyvinyl acetal resin. Furthermore, based on the ethylene units in the main chain of the polyvinyl acetal resin, it is preferably 9 to 29 mol%, more preferably 12 to 26 mol%, even more preferably 15 to 23 mol%, and particularly preferably 16 to 20 mol%. The content of vinyl alcohol units can be adjusted within the above range by adjusting the amount of aldehyde used when acetalizing polyvinyl alcohol. When the content of vinyl alcohol units is within the above range, the refractive index difference with the resin film (X) becomes smaller, making it easier to reduce optical unevenness in the laminated glass including the composite film. When the base material (Y) contains two or more different polyvinyl acetal resins, it is preferable that the content of vinyl alcohol units in at least one of the polyvinyl acetal resins is within the above range.

[0030] Polyvinyl acetal resin is typically composed of acetal group units, vinyl alcohol units, and vinyl acetate units. The amount of each of these units can be measured, for example, by JIS K 6728 "Test Method for Polyvinyl Butyral" or by nuclear magnetic resonance (NMR).

[0031] If polyvinyl acetal resin contains units other than acetal group units, vinyl alcohol units, and vinyl acetate group units, the amount of vinyl alcohol units and vinyl acetate units can be measured, and the amount of the remaining other units can be calculated by subtracting both of these amounts from the amount of acetal group units.

[0032] In one embodiment of the present invention, the viscosity of a 10% by mass toluene / ethanol = 1 / 1 (mass ratio) solution of polyvinyl acetal resin, measured using a Brookfield type (Type B) viscometer at 20°C and 30 rpm, is preferably 100 mPa·s or more, more preferably 120 mPa·s or more, even more preferably 150 mPa·s or more, and may be 200 mPa·s or more, 240 mPa·s or more, or 265 mPa·s or more. By using or combining a polyvinyl acetal resin manufactured using polyvinyl alcohol with a high viscosity-average degree of polymerization as a raw material or as part of a raw material, the viscosity of the polyvinyl acetal resin can be adjusted to be above the above lower limit. When the polyvinyl acetal resin consists of a mixture of multiple resins, it is preferable that the viscosity of such mixture is above the above lower limit. When the viscosity of the polyvinyl acetal resin is above the above lower limit, deformation and disconnection of the functional layer are easily suppressed during the manufacture of laminated glass, and the phenomenon of glass shifting due to heat in the resulting laminated glass is easily prevented. From the viewpoint of obtaining good film-forming properties, the viscosity is, for example, 2000 mPa·s or less, preferably 1500 mPa·s or less, more preferably 1000 mPa·s or less, even more preferably 800 mPa·s or less, even more preferably 500 mPa·s or less, particularly preferably 450 mPa·s or less, and particularly more preferably 400 mPa·s or less.

[0033] In one embodiment of the present invention, the peak-top molecular weight of the polyvinyl acetal resin is preferably 115,000 to 200,000, more preferably 120,000 to 160,000, and even more preferably 130,000 to 150,000. By using or combining a polyvinyl acetal resin manufactured using polyvinyl alcohol with a high viscosity-average degree of polymerization as a raw material or as part of a raw material, the peak-top molecular weight of the polyvinyl acetal resin can be adjusted to the above range. When the peak-top molecular weight of the polyvinyl acetal resin is within the above range, the lamination and process passability of the composite film are easily improved. Furthermore, film properties such as creep resistance and tensile strength are also easily improved. The molecular weight distribution of the polyvinyl acetal resin, that is, the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn) (Mw / Mn), is preferably 2.7 or higher, more preferably 2.8 or higher, and particularly preferably 2.9 or higher. For example, the molecular weight distribution of the polyvinyl acetal resin can be adjusted to be above the lower limit by acetalizing a mixture of polyvinyl alcohols with different viscosity-average degrees of polymerization, or by mixing acetalized polyvinyl alcohols with different viscosity-average degrees of polymerization. When the molecular weight distribution of the polyvinyl acetal resin is above the lower limit, the laminating properties and process passability of the composite film are easily improved. Furthermore, film properties such as creep resistance and tensile strength are also easily improved. The upper limit of the molecular weight distribution is not particularly limited, but from the viewpoint of ease of film formation, it is usually 10 or less, preferably 5 or less. When the substrate (Y) contains two or more polyvinyl acetal resins with different properties, it is preferable that the peak top molecular weight and molecular weight distribution of at least one polyvinyl acetal resin are within the above range. The peak top molecular weight and molecular weight distribution can be determined, for example, using gel permeation chromatography (GPC), with polystyrene of known molecular weight as a standard.

[0034] In one embodiment of the present invention, the substrate (Y) preferably contains an uncrosslinked polyvinyl acetal from the viewpoint of easily obtaining good film-forming properties. The substrate (Y) may also contain a crosslinked polyvinyl acetal. Methods for crosslinking polyvinyl acetal are described, for example, in EP 1527107B1 and WO 2004 / 063231 A1 (Thermal self-crosslinking of carboxyl group-containing polyvinyl acetal), EP 1606325 A1 (Polyvinyl acetal crosslinked with polyaldehyde), and WO 2003 / 020776 A1 (Polyvinyl acetal crosslinked with glyoxylic acid). Furthermore, it is also a useful method to control the amount of intermolecular acetal bonds generated or the degree of blocking of residual hydroxyl groups by appropriately adjusting the acetalization reaction conditions.

[0035] The base material (Y) may contain an ionomer resin. Examples of ionomer resins include resins having constituent units derived from ethylene and constituent units derived from α,β-unsaturated carboxylic acids, wherein at least a portion of the constituent units derived from α,β-unsaturated carboxylic acids are neutralized by metal ions such as sodium ions. In the ethylene-α,β-unsaturated carboxylic acid copolymer before neutralization by metal ions, the content of constituent units derived from α,β-unsaturated carboxylic acids is preferably 2% by mass or more, and more preferably 5% by mass or more, based on the mass of the ethylene-α,β-unsaturated carboxylic acid copolymer. Furthermore, the content of the above α,β-unsaturated carboxylic acid constituent units is preferably 30% by mass or less, and more preferably 20% by mass or less. Examples of constituent units derived from α,β-unsaturated carboxylic acids that the above ionomer resin has include constituent units derived from acrylic acid, methacrylic acid, maleic acid, monomethyl maleate, monoethyl maleate, and maleic anhydride, among which constituent units derived from acrylic acid or methacrylic acid are particularly preferred. From the viewpoint of availability, ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers are more preferred as the above-mentioned ionomer resins, and zinc ionomers of ethylene-acrylic acid copolymers, sodium ionomers of ethylene-acrylic acid copolymers, zinc ionomers of ethylene-methacrylic acid copolymers, and sodium ionomers of ethylene-methacrylic acid copolymers are particularly preferred.

[0036] The substrate (Y) (preferably the substrate layer) may contain a plasticizer. The amount of plasticizer in the substrate (Y) is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less, relative to the mass of the substrate (Y) (or substrate layer). It may also be 3% by mass or less or 1% by mass or less, and may substantially contain no plasticizer. When the amount of plasticizer is below the above upper limit, it is easier to manufacture a substrate (Y) with excellent film-forming properties and handling properties, and deformation of the functional layer during the production of the resulting laminated glass is easily suppressed, resulting in the effective expression of the functional layer. In addition, it is easier to improve the lamination properties and process passability of the composite film. The amount of plasticizer in the substrate (Y) is usually 0% by mass or more. If a plasticizer is included, the lower limit may be 0.1% by mass or more.

[0037] Preferably, one or more compounds from the following group can be used as plasticizers. • Esters of polyvalent aliphatic or aromatic acids. Examples of such esters include dialkyl adipates (e.g., dihexyl adipate, di-2-ethylbutyl adipate, dioctyl adipate, di-2-ethylhexyl adipate, hexylcyclohexyl adipate, a mixture of heptyl adipate and nonyl adipate, diisononyl adipate, heptylnonyl adipate); esters of adipic acid with alcohols containing alicyclic ester alcohols or ether compounds (e.g., di(butoxyethyl) adipate, di(butoxyethoxyethyl) adipate); dialkyl sebacates (e.g., dibutyl sebacate); esters of sebatic acid with alcohols containing alicyclic or ether compounds; esters of phthalic acid (e.g., butyl benzyl phthalate, bis-2-butoxyethyl phthalate); and esters of alicyclic polycarboxylic acids with aliphatic alcohols (e.g., 1,2-cyclohexanedicarboxylic acid diisononyl ester). • Esters or ethers of polyhydric aliphatic or aromatic alcohols or oligoether glycols having one or more aliphatic or aromatic substituents. Examples of such esters or ethers include esters of glycerin, diglycol, triglycol, tetraglycol, etc., with linear or branched aliphatic or alicyclic carboxylic acids. More specifically, examples include diethylene glycol-bis-(2-ethylhexanoate), triethylene glycol-bis-(2-ethylhexanoate), triethylene glycol-bis-(2-ethylbutanoate), tetraethylene glycol-bis-n-heptanoate, triethylene glycol-bis-n-heptanoate, triethylene glycol-bis-n-hexanoate, tetraethylene glycol dimethyl ether, and dipropylene glycol benzoate. • Phosphate esters of aliphatic or aromatic ester alcohols. Examples of such phosphate esters include tris(2-ethylhexyl) phosphate (TOF), triethyl phosphate, diphenyl-2-ethylhexyl phosphate, and tricresyl phosphate. • Esters of citric acid, succinic acid, and / or fumaric acid.

[0038] Furthermore, polyesters or oligoesters composed of polyhydric alcohols and polyhydric carboxylic acids, their terminal esterified or etherified products, polyesters or oligoesters composed of lactones or hydroxycarboxylic acids, or their terminal esterified or etherified products may be used as plasticizers.

[0039] When a plasticizer is included in the substrate (Y), it is preferable to use the same plasticizer as that included in the resin film (X), or a plasticizer that does not impair the properties of the resin film (X) (e.g., heat resistance, light resistance, transparency, and plasticization efficiency), from the viewpoint of suppressing problems associated with the migration of the plasticizer between the substrate (Y) and the resin film (X) (e.g., problems such as changes in physical properties over time). From this viewpoint, it is preferable that the plasticizer includes triethylene glycol-bis-(2-ethylhexanoate) (3GO or 3G8), triethylene glycol-bis(2-ethylbutanoate), tetraethylene glycol-bis-(2-ethylhexanoate), and tetraethylene glycol-bisheptanoate, and it is particularly preferable that it includes triethylene glycol-bis-(2-ethylhexanoate) (3GO or 3G8).

[0040] The substrate (Y) (preferably the substrate layer) may contain other additives. Examples of such additives include water, ultraviolet absorbers, antioxidants, adhesion modifiers, whitening agents or fluorescent whitening agents, stabilizers, dyes, processing aids, impact resistance modifiers, flowability modifiers, crosslinking agents, pigments, luminescent materials, refractive index modifiers, heat shielding materials, organic or inorganic nanoparticles, calcined silicic acid, and surfactants. These additives can be used individually or in combination of two or more. Functional Z may be imparted by incorporating additives into the substrate layer and / or Z layer contained in the substrate (Y). For example, tin-doped indium oxide (ITO) can be incorporated into the substrate layer to impart infrared absorption. When the substrate (Y) contains additives, the content of the additives is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, relative to the mass of the substrate (Y). When the additives are contained in the substrate layer within the substrate (Y), the content of the additives may be based on the substrate layer.

[0041] In the composite film of the present invention, the method for manufacturing the substrate (Y) having function Z is not particularly limited. For example, if the substrate (Y) consists of a substrate layer having function Z, a resin forming the substrate layer and optionally an additive, preferably a resin forming the substrate layer and an additive capable of imparting function Z, may be blended, mixed, for example, uniformly kneaded, and then a film or sheet (layer) may be produced by known film-forming methods such as extrusion, calendering, pressing, casting, or inflation, and this can be used as the substrate (Y). Alternatively, for example, if the substrate (Y) is a substrate in which a Z layer is laminated on a substrate layer, it can be obtained by forming a substrate layer from a resin or resin composition, and then laminating the Z layer on the substrate layer using a conventional method such as lamination. In this specification, a mixture of a resin with additives added is referred to as a resin composition. Furthermore, embossing or the like may be applied to the surface of the substrate (Y) for the purpose of creating voids in the composite film or adjusting the size of the voids, surface roughness, etc.

[0042] In the production of a substrate (Y) having function Z, among known methods, a method of producing a film or sheet (layer) using an extruder is particularly preferred. The resin temperature during extrusion can be appropriately selected depending on the type of resin or resin composition. For example, if the resin is polyvinyl acetal resin, 150 to 250°C is preferred, and 170 to 230°C is more preferred. If the resin temperature is below the above upper limit, the decomposition of the polyvinyl acetal resin can be suppressed, and the content of volatile substances can be reduced. Also, if the resin temperature is above the above lower limit, the content of volatile substances can be reduced. In order to efficiently remove volatile substances, it is preferable to remove them by reducing the pressure from the vent port of the extruder. When producing the substrate (Y) using an extruder, the substrate layer may be melt-extruded onto a metal foil, as will be described later.

[0043] In a composite film according to one embodiment of the present invention, the function Z is conductive, and the substrate (Y) preferably contains at least one selected from the group consisting of gold, silver, copper, metal oxides, organic conductive materials, and carbon compounds. Such a composite film is suitable because, when laminated glass is made using the composite film, ice and fogging that occur on the laminated glass can be efficiently removed. Examples of the substrate (Y) in such embodiments include a substrate comprising a substrate layer that is conductive and contains at least one selected from the group consisting of gold, silver, copper, metal oxides, organic conductive materials, and carbon compounds, or a substrate comprising a Z layer that is conductive and contains at least one selected from the group consisting of gold, silver, copper, metal oxides, organic conductive materials, and carbon compounds, and a substrate layer that is not conductive. Alternatively, both the substrate layer and the Z layer may be conductive and contain at least one selected from the group consisting of gold, silver, copper, metal oxides, organic conductive materials, and carbon compounds.

[0044] In a composite film according to one embodiment of the present invention, function Z is conductive, and the substrate (Y) preferably has a conductive structure formed by at least one method selected from the group consisting of etching, printing, coating, and vapor deposition. The substrate (Y) in such an embodiment is preferably a substrate having a substrate layer and a conductive structure formed by at least one method selected from the group consisting of etching, printing, coating, and vapor deposition, and more preferably a substrate on which the conductive structure is disposed on the substrate layer. The etching, printing, coating, and vapor deposition methods for forming the conductive structure can each be carried out by conventional methods.

[0045] Specific examples of a substrate (Y) having function Z as conductivity include a substrate having a conductive structure on the surface of a substrate layer or between two substrate layers, either by a printing method using conductive ink or a conductive structure based on metal foil. A substrate having a conductive structure on the surface of a substrate layer by a printing method using conductive ink may be manufactured, for example, by printing a conductive ink containing conductive particles and / or conductive fibers onto the surface of a substrate layer using screen printing, flexographic printing, or gravure printing. A substrate having a conductive structure based on metal foil on the surface of a substrate layer may be manufactured, for example, by overlapping a substrate layer and a metal foil and heat-pressing them together, or by melt-extruding a substrate layer onto a metal foil and then fabricating a conductive structure using a photolithography method.

[0046] A substrate having a conductive structure printed with conductive ink or a conductive structure based on metal foil between two substrate layers may be manufactured by superimposing another substrate layer onto the surface of the conductive structure of the substrate layer having the conductive structure manufactured as described above and heat-pressing it, or by melt-extruding the resin or resin composition constituting the other substrate layer onto the surface of the conductive structure, or by coating the substrate layer onto the surface of the conductive structure by a casting method. The resin or resin composition constituting the substrate layer that is first joined to the metal foil and the resin or resin composition constituting the substrate layer that is later joined to the metal foil may have the same composition or different compositions.

[0047] When manufacturing a substrate (Y) by layering a substrate layer and a metal foil and then thermally bonding them together, followed by fabricating a conductive structure using photolithography, the process of joining the substrate layer and the metal foil can be carried out, for example, by the following method. • A method of layering a substrate layer and a metal foil and heat-pressing them together. - A method of joining a metal foil by coating it with a molten resin or resin composition constituting the base layer, for example, a method of melt-extruding the resin or resin composition onto the metal foil, or a method of applying the resin or resin composition onto the metal foil by knife coating or the like, A method of bonding a metal foil and a substrate layer by applying a solvent, or a solution or dispersion of a resin composition containing the resin and solvent that constitute the substrate layer, to one or both of the metal foil and the substrate layer, or by injecting it between the metal foil and the substrate layer.

[0048] The bonding temperature during thermocompression bonding depends on the type of resin that makes up the base layer, but is usually 70 to 180°C, preferably 90 to 170°C, more preferably 100 to 165°C, and even more preferably 110 to 160°C. Good bonding strength is easily obtained when the bonding temperature is within the above range. As mentioned earlier, the resin temperature during extrusion is preferably 150-250°C, more preferably 170-230°C, from the viewpoint of reducing the content of volatile substances in the substrate layer. Furthermore, in order to efficiently remove volatile substances, it is preferable to remove them by reducing the pressure from the vent port of the extruder. Furthermore, it is preferable to use a plasticizer that is commonly used in resins constituting the base layer as the solvent. Examples of such plasticizers include those exemplified above.

[0049] The process of forming a conductive structure from the obtained metal foil substrate layer can be carried out using a known photolithography technique. This process can be carried out, for example, as described in a later example, by laminating a dry film resist onto the metal foil of the metal foil substrate layer, forming an etching resistance pattern using a photolithography technique, then immersing the substrate layer with the etching resistance pattern in a copper etching solution to form a conductive structure, and finally removing the remaining photoresist layer by a known method.

[0050] A method for manufacturing a substrate (Y) having such function Z can easily and simply form a conductive structure of a desired shape, thereby significantly improving production efficiency when imparting a conductive structure to a substrate layer.

[0051] In one embodiment of the present invention, the thickness of the conductive structure is preferably 1 to 30 μm, more preferably 2 to 20 μm, even more preferably 3 to 15 μm, and particularly preferably 3 to 13 μm, from the viewpoint of reducing light reflection and easily obtaining the required amount of heat. The thickness of the conductive structure can be measured, for example, using a thickness gauge or a laser microscope.

[0052] From the viewpoint of forward visibility and ease of obtaining the required amount of heat, the conductive structure preferably has a linear, grid-like, or mesh-like shape. Here, examples of linear shapes include straight lines, wavy lines, and zigzag shapes. A single conductive structure may have a single shape or a mixture of multiple shapes.

[0053] The line width of the conductive structure forming a linear, grid-like, or mesh-like shape is preferably 1 to 50 μm, more preferably 2 to 30 μm, and particularly preferably 3 to 20 μm. When the line width of the conductive structure is within the above range, sufficient heat generation is easily ensured, and the desired forward visibility is easily obtained.

[0054] From the viewpoint of suppressing corrosion of conductive structures, the substrate (Y), preferably the substrate layer, may contain a corrosion inhibitor. When a corrosion inhibitor is contained, the amount of corrosion inhibitor contained in the substrate (Y) is preferably 0.005 to 5% by mass, based on the mass of the substrate (Y). Examples of corrosion inhibitors include substituted or unsubstituted benzotriazoles.

[0055] In one embodiment of the present invention, the thickness of the substrate (Y) is preferably 1 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, even more preferably 15 μm or more, particularly preferably 20 μm or more, preferably 100 μm or less, more preferably 95 μm or less, even more preferably 90 μm or less, even more preferably 85 μm or less, particularly preferably 80 μm or less, and particularly preferably 75 μm or less. If the thickness of the substrate (Y) is above the lower limit above, problems such as distortion in the conductive structure due to shrinkage or deformation of the substrate (Y) are less likely to occur. If the thickness of the substrate (Y) is below the upper limit above, when the resin film (X) contains a plasticizer, the amount of plasticizer transfer from the resin film (X) to the substrate (Y) is reduced, and the decrease in the amount of plasticizer in the resin film (X) is suppressed, so problems such as increased head impact during collisions of vehicles equipped with vehicle glass using the composite film of the present invention are less likely to occur. In addition, if the substrate (Y) is within the above range, the lamination and process passability of the composite film are easily improved. The thickness of the substrate (Y) can be measured using a thickness gauge or a laser microscope.

[0056] In one embodiment of the present invention, the substrate (Y) preferably includes a substrate layer having a tensile storage modulus E'(40) at 40°C, preferably 0.1 GPa or more. The tensile storage modulus E'(40) of the substrate layer is more preferably 0.2 GPa or more, even more preferably 0.5 GPa or more, even more preferably 0.7 GPa or more, particularly preferably 1.0 GPa or more, preferably 10 GPa or less, more preferably 5.0 GPa or less, and even more preferably 3.0 GPa or less. If the tensile storage modulus E'(40) is above the lower limit above, deformation due to heating in the bonding process is easily suppressed, and if the tensile storage modulus E'(40) is below the upper limit above, wrinkles and the like are easily suppressed in the manufacturing process of laminated glass. The tensile storage modulus E'(40) of the substrate (Y) can be measured using a dynamic viscoelastic device, for example, by the method described in the examples.

[0057] In one embodiment of the present invention, the average value of the ten-point average roughness (sometimes denoted as RzY) measured at any five locations on the surface of the substrate (Y) that is not in contact with the resin film (X), in accordance with JIS B 0601:1994, is preferably 0.1 μm or more, more preferably 0.5 μm or more, even more preferably 1.0 μm or more, even more preferably 1.5 μm or more, particularly preferably 2.0 μm or more, particularly more preferably 3.0 μm or more, preferably 20 μm or less, more preferably 18 μm or less, and even more preferably 15 μm or less. If the average value RzY of the ten-point average roughness is above the lower limit above, it is easier to improve the degassing performance in the glass lamination process of the composite film, and if it is below the upper limit above, it is easier to improve the lamination properties of the composite film. The average value RzY of the ten-point average roughness is obtained by cutting out strips of the composite film from the center point of the substrate Y in the width direction, with the strips measuring 10 mm in the width direction and 200 mm in the length direction, at five locations (designated as A, B, C (center), D, and E, in order) that are continuous in the width direction; then, for each of the samples (test pieces) B, C, and D, the resin film (X) is peeled off from the composite film, and the surface of the substrate (Y) that is not in contact with the resin film (X) is measured using a surface roughness meter at five arbitrary locations in accordance with JIS B0601:1994, and the average value of the ten-point average roughness is obtained, for example, by the method described in the examples. The average value RzY of the ten-point average roughness can be adjusted to the above range by appropriately adjusting the composition of the substrate (Y), such as the type and content of resins and additives contained in the substrate (Y); the surface roughness and void size of the substrate (Y) before composite formation (e.g., before the heat compression process); the manufacturing conditions of the substrate (Y); and the manufacturing conditions of the composite film. For example, the above range can be adjusted by using the above preferred resins and functional Z as the substrate (Y), or by appropriately adjusting the surface temperature and linear pressure of the rolls in the manufacturing conditions of the composite film described later.Furthermore, if the surface of the substrate (Y) has an adhesive layer (U) on a side that is not in contact with the resin film (X), and the adhesive layer (U) is the outermost layer, it is preferable that the average value of the ten-point average roughness measured at any five locations on the surface of the adhesive layer (U) that is not in contact with the substrate (Y), in accordance with JIS B 0601:1994, is within the above range.

[0058] <Resin film (X)> The composite film of the present invention comprises a resin film (X). The resin film (X) has a surface A and a surface B, where surface B is the side that is in close contact with the substrate (Y), and surface A is the side that is not in close contact with the substrate (Y).

[0059] The resin film (X) preferably contains a resin. Examples of the resin include those listed in the section <Substrate (Y) having function Z>, and among these, thermoplastic resins are preferred from the viewpoint of easily improving laminating properties and process passability, at least one selected from the group consisting of polyvinyl acetal resin, ionomer resin, poly(meth)acrylic resin, polyolefin resin, and polycarbonate resin is more preferred, and polyvinyl acetal resin and / or ionomer resin is even more preferred.

[0060] The polyvinyl acetal resin that may be included in the resin film (X) can be the same as the polyvinyl alcohol resin described in the section <Substrate (Y) having function Z>, and preferably the same as the polyvinyl alcohol resin described in the section <Substrate (Y) having function Z>, except that the range of acetalization degree, alcohol unit content, and vinyl acetate unit content is within the range of the preferred embodiment described below.

[0061] In a preferred embodiment of the present invention, the content of vinyl alcohol units in the polyvinyl acetal resin that may be contained in the resin film (X) is preferably 6 mol% or more, more preferably 12 mol% or more, even more preferably 15 mol% or more, even more preferably 18 mol% or more, preferably 45 mol% or less, more preferably 40 mol% or less, even more preferably 35 mol% or less, and even more preferably 31 mol% or less, based on the ethylene units of the polyvinyl acetal main chain. The content of vinyl alcohol units can be adjusted to the above range by adjusting the amount of aldehyde used when acetalizing the polyvinyl alcohol resin. When the content of vinyl alcohol units is within the above range, laminated glass with excellent puncture resistance, adhesion, or sound insulation is easily obtained. In addition, the lamination and process passability of the composite film are easily improved. When the resin film (X) contains two or more different polyvinyl acetal resins, it is preferable that the content of vinyl alcohol units of at least one polyvinyl acetal resin is within the above range.

[0062] In a preferred embodiment of the present invention, the degree of acetalization of the polyvinyl acetal resin that may be contained in the resin film (X) is not particularly limited, but is preferably 40 mol% or more, more preferably 45 mol% or more, even more preferably 50 mol% or more, even more preferably 60 mol% or more, particularly preferably 65 mol% or more, preferably 86 mol% or less, more preferably 84 mol% or less, even more preferably 82 mol% or less, and even more preferably 78 mol% or less. By appropriately adjusting the amount of aldehyde used when acetalizing the polyvinyl alcohol resin, the degree of acetalization of the polyvinyl acetal resin can be adjusted to the above range. When the degree of acetalization is within the above range, it is easier to improve the penetration resistance or adhesion to glass when laminated glass is made from the composite film. It is also easier to improve the lamination and process passability of the composite film. When the resin film (X) contains two or more different polyvinyl acetal resins, it is preferable that the degree of acetalization of at least one of the polyvinyl acetal resins is within the above range.

[0063] In a preferred embodiment of the present invention, the content of vinyl acetate units in the polyvinyl acetal resin that may be contained in the resin film (X) is preferably 0.05 mol% or more, more preferably 0.1 mol% or more, even more preferably 0.2 mol% or more, even more preferably 0.5 mol% or more, preferably 20 mol% or less, more preferably 10 mol% or less, even more preferably 5 mol% or less, and even more preferably 3 mol% or less, based on the ethylene units of the polyvinyl acetal main chain. The content of vinyl acetate units can be adjusted to the above range by appropriately adjusting the degree of saponification of the raw material polyvinyl alcohol. When a polyvinyl acetal resin with a vinyl acetate unit content within the above range is included, it is easier to obtain a film with excellent compatibility with plasticizers when plasticizers are used. It is also easier to improve the lamination and process passability of the composite film. When the resin film (X) contains two or more different polyvinyl acetal resins, it is preferable that the content of vinyl acetate units of at least one of the polyvinyl acetal resins is within the above range.

[0064] The ionomer resin that may be included in the resin film (X) is, for example, the same as the ionomer resin described in the section on <Substrate (Y) having function Z>.

[0065] The resin film (X) may contain a plasticizer, and it is preferable that it contains a plasticizer from the viewpoint of easily improving lamination and process passability. As the plasticizer, the plasticizer described in the section <Substrate (Y) having function Z> can be used. When the resin film (X) contains a plasticizer, the plasticizer content in the state before the composite film is made (before lamination with the substrate (Y)) is preferably 16.0% by mass or more, more preferably 16.1% by mass or more, even more preferably 22.0% by mass or more, even more preferably 26.0% by mass or more, preferably 36.0% by mass or less, more preferably 32.0% by mass or less, and even more preferably 30.0% by mass or less, based on the mass of the resin film (X). When the plasticizer content is within the above range, laminated glass with excellent impact resistance is easily obtained. In addition, the lamination and process passability of the composite film are easily improved. Furthermore, a resin film (X) having sound insulation function can also be used as the resin film (X). In that case, the plasticizer content, in the state before the composite film is made (before lamination with the substrate (Y)), is preferably 30% by mass or more, more preferably 30-50% by mass, even more preferably 31-40% by mass, and particularly preferably 32-35% by mass, relative to the mass of the resin film (X).

[0066] In one embodiment of the present invention, when the base material (Y) and the resin film (X) each contain polyvinyl acetal resin, the difference between the content of vinyl alcohol units in the polyvinyl acetal resin constituting the base material (Y) and the content of vinyl alcohol units in the polyvinyl acetal resin constituting the resin film (X) is preferably 4% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. When the polyvinyl acetal resin constituting the base material (Y) and / or the polyvinyl acetal resin constituting the resin film (X) consists of a mixture of multiple resins, it is preferable that the difference between the content of vinyl alcohol units in at least one polyvinyl acetal resin constituting the base material (Y) and the content of vinyl alcohol units in at least one polyvinyl acetal resin constituting the resin film (X) is less than or equal to the upper limit. When the difference is less than or equal to the upper limit, the difference in refractive index between the base material (Y) and the resin film (X) becomes small in the equilibrium state after the plasticizer has migrated in the composite film, which is preferable because it makes it difficult to see the boundary between the base material (Y) and the resin film (X) when they are used, even when they are different in size. On the other hand, one preferred embodiment is to make the content of vinyl alcohol units in the polyvinyl acetal resin constituting the base material (Y) lower than the content of vinyl alcohol units in the polyvinyl acetal resin constituting the resin film (X), thereby making the average amount of plasticizer in the base material (Y) at equilibrium after the plasticizer has migrated in the composite film 30% by mass or more. In this case, the content of vinyl alcohol units in the polyvinyl acetal resin constituting the base material (Y) is preferably 5% by mass or more lower than the content of vinyl alcohol units in the polyvinyl acetal resin constituting the resin film (X), and more preferably 8% by mass or more lower. It is preferable that the difference in the content of vinyl alcohol units is above the lower limit, as this allows for a sufficiently high amount of plasticizer in the base material (Y) at equilibrium, making it easier to obtain laminated glass with sound insulation function.

[0067] The resin film (X) may optionally contain the additives described in the section <Substrate (Y) having function Z>. If the resin film (X) contains additives, the amount of additives is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, relative to the mass of the resin film (X).

[0068] The resin film (X) may be a single-layer film or a laminated film, but it is preferable that it be a single-layer film.

[0069] The method for manufacturing the resin film (X) is not particularly limited, but for example, it is the same as the method for manufacturing the substrate (Y) described in the section on <Substrate (Y) having function Z>. For example, after mixing or kneading the resin constituting the resin film (X) and optionally a plasticizer and / or additive, a film or sheet (layer) can be produced by known film-forming methods such as extrusion, calendering, pressing, casting, or inflation, and this can be made into the resin film (X). Furthermore, embossing or the like may be applied to the surface of the resin film (X) for the purpose of creating voids in the composite film or adjusting the size of the voids, surface roughness, etc.

[0070] The thickness of the resin film (X) is preferably 50 μm or more, more preferably 100 μm or more, even more preferably 300 μm or more, even more preferably 500 μm or more, particularly preferably 700 μm or more, preferably 1600 μm or less, more preferably 1200 μm or less, and even more preferably 1100 μm or less. The resin film (X) may also have regions where the cross-sectional shape in the thickness direction is wedge-shaped. When the thickness of the resin film (X) is within the above range, it is easy to obtain excellent puncture resistance. It is also easy to improve the lamination and process passability of the composite film. The above thickness can be measured using a thickness gauge or a laser microscope.

[0071] In one embodiment of the present invention, in the resin film (X) included in the composite film of the present invention, the average value RzA of the ten-point average roughness of surface A measured at any five locations in accordance with JIS B0601:1994 is preferably 0.1 μm or more, more preferably 1 μm or more, even more preferably 5 μm or more, even more preferably 10 μm or more, particularly preferably 15 μm or more, particularly more preferably 20 μm or more, preferably 50 μm or less, more preferably 45 μm or less, even more preferably 42 μm or less, and even more preferably 40 μm or less. When the average value RzA of the ten-point average roughness of surface A is within the above range, the lamination properties of the composite film are easily improved. The average value RzA of the ten-point average roughness is obtained by cutting out strips of the composite film from the center point of the substrate Y in the width direction, with the strips measuring 10 mm in the width direction and 200 mm in the length direction, at five locations (designated as A, B, C (center), D, and E, in order) that are continuous in the width direction; then, for each of the samples (test pieces) B, C, and D, the resin film (X) is peeled off from the composite film, and the surface A of the resin film (X) is measured using a surface roughness meter at five arbitrary locations in accordance with JIS B0601:1994, and the average value of the ten-point average roughness is obtained, for example, by the method described in the examples.

[0072] In one embodiment of the present invention, the average value RzB of the ten-point average roughness of surface B of the resin film (X) included in the composite film of the present invention, measured in accordance with JIS B0601:1994, is preferably 0.1 μm or more, more preferably 1 μm or more, even more preferably 3 μm or more, even more preferably 5 μm or more, particularly preferably 7 μm or more, particularly more preferably 9 μm or more, extremely preferably 10 μm or more, preferably 50 μm or less, more preferably 45 μm or less, even more preferably 42 μm or less, and even more preferably 40 μm or less. If the average value RzB of the ten-point average roughness of surface B is above the lower limit above, the laminating properties of the composite film are easily improved, and if it is below the upper limit above, the process passability of the composite film is easily improved. In particular, the larger the average value RzB of the ten-point average roughness, the larger the size of the void (especially the void height) between surface B of the resin film (X) and the substrate (Y), and it is considered that laminating properties are easily improved. The average value RzB of the ten-point average roughness is obtained by cutting out five strips of the composite film (designated A, B, C (center), D, and E in order) from the center point of the substrate Y in the width direction, with the center point being 10 mm in the width direction and 200 mm in the length direction, so as to be continuous in the width direction; then, for each of the samples (test pieces) B, C, and D, the resin film (X) is peeled off from the composite film, and the surface B of the resin film (X) is measured using a surface roughness meter at five arbitrary locations in accordance with JIS B0601:1994, and the average value of the ten-point average roughness is obtained, for example, by the method described in the examples. The average values ​​RzA and RzB of the ten-point average roughness can be adjusted to the above range by appropriately adjusting the composition of the resin film (X), such as the type and content of resins and additives contained in the resin film (X); the surface roughness and void size of the resin film (X) before composite formation (e.g., before the heat compression process); the manufacturing conditions of the resin film (X); and the manufacturing conditions of the composite film. For example, the above range can be adjusted by using the above preferred resins and additives as the resin film (X), or by appropriately adjusting the surface temperature and linear pressure of the roll in the manufacturing conditions of the composite film described later.

[0073] In one embodiment of the present invention, the composite film of the present invention is of formula (1): 10 <RzB×100 / RzA<140 (1) [In the formula, RzA represents the average value of the ten-point average roughness of surface A measured at any five locations in accordance with JIS B0601:1994, and RzB represents the average value of the ten-point average roughness of surface B measured at any five locations in accordance with JIS B0601:1994.] It is preferable that the following conditions are met. When RzA and RzB satisfy the relationship in equation (1), the lamination and process passability of the composite film are easily improved.

[0074] RzB×100 / RzA is preferably 20 or more, more preferably 40 or more, even more preferably 60 or more, even more preferably 80 or more, particularly preferably 90 or more, and especially more preferably 100 or more, and preferably 135 or less, more preferably 130 or less, even more preferably 120 or less, and even more preferably 110 or less. When RzB×100 / RzA is within the lower range above, the lamination properties of the composite film are easily improved.

[0075] <Composite film> The composite film of the present invention comprises a resin film (X) and a substrate (Y) having the function Z, wherein at least an adhesive portion and a void exist between surface B of the resin film (X) and the substrate (Y), and the adhesion force between surface B and the substrate (Y) is 0.2 N / cm or more. If there is no void between surface B of the resin film (X) and the substrate (Y), the lamination properties of the composite film are insufficient, and if the adhesion force between surface B and the substrate (Y) is less than 0.2 N / cm, the process passability of the composite film is insufficient. Since the composite film of the present invention has the adhesive portion and the void and the adhesion force is 0.2 N / cm or more, it can achieve both high lamination properties and excellent process passability. Therefore, the composite film of the present invention can be suitably used as a resin interlayer that can impart functionality to laminated glass. In this specification, the process passability of a composite film refers to its ability to suppress or prevent delamination between the resin film (X) and the substrate (Y) during the manufacturing process of the composite film, and the higher the process passability or the better the process passability, the easier it is to suppress or prevent such delamination. Furthermore, in this specification, the laminating properties of a composite film refer to its laminating properties when making laminated glass, and more specifically, it refers to its ability to suppress or prevent the occurrence of appearance defects such as bubbles when laminated glass made using a composite film is exposed to a high-temperature environment, and the higher the laminating properties or the better the laminating properties, the easier it is to suppress or prevent the occurrence of appearance defects such as bubbles. Therefore, the laminating properties of a composite film can also be said to be the heat resistance of laminated glass made using a composite film.

[0076] One method for investigating whether there are adhesive areas and voids between the surface B of the resin film (X) and the substrate (Y) is to cut the composite film along its width and observe the cut surface with a microscope. For example, Figure 1 is a photograph of a cross-section obtained by cutting a composite film according to one embodiment of the present invention along its width and observing it with a microscope, and Figure 2 is a magnified photograph of the void portion in the same photograph obtained by cutting a composite film according to one embodiment of the present invention along its width and observing it with a microscope. Figures 1 and 2 show one embodiment of the present invention, and the present invention is not limited to these embodiments. As shown in Figures 1 and 2, it can be confirmed that a gap 3 and an adhesive portion 4 exist between the surface B of the resin film 1 and the substrate 2. Both ends of the gap 3 are composed of two adhesive portions 4.

[0077] In this specification, the width of the void represents the distance between the centers of two adhesive portions that make up both ends of the void (also referred to as the distance between the two adhesive portions), and the height of the void represents the distance between the surface B of the resin film (X) and the substrate (Y) in the center of the void. Furthermore, the center of the void represents the center between the two adhesive portions. For example, as shown in Figure 2, the width 5 of the void 3 is the distance between the centers of the two adhesive portions 4 that make up both ends, and the height 6 of the void 3 is the distance between the surface B of the resin film 1 and the substrate 2 in the center of the void 3.

[0078] In one embodiment of the present invention, when a cross-section of the composite film in the width direction, over a 10 cm range in the central part of the width direction, is observed with a microscope, it is found to have multiple adhering portions and voids existing at both ends, with 90% or more of all voids having a width of preferably 2.0 mm or less, more preferably 1.5 mm or less, even more preferably 1.0 mm or less, even more preferably 0.7 mm or less, particularly preferably 0.5 mm or less, preferably 0.01 mm or more, more preferably 0.05 mm or more, and even more preferably 0.1 mm or more. When the width of 90% or more of all voids is within the above range, the laminating properties are easily improved. The width of the voids is as defined above, and whether the width of 90% or more of all voids is within the above range can be measured, for example, by the method described in the examples.

[0079] In one embodiment of the present invention, when the cross-section of the composite film of the present invention is observed with a microscope along the width direction of the composite film in a 10 cm range in the central part of the width direction, it has a plurality of adhering portions and voids with two adjacent adhering portions at both ends, and the average width of the voids is preferably 10 μm or more, more preferably 50 μm or more, even more preferably 100 μm or more, even more preferably 150 μm or more, particularly preferably 200 μm or more, preferably 1500 μm or less, more preferably 1000 μm or less, even more preferably 700 μm or less, even more preferably 500 μm or less, particularly preferably 400 μm or less. When the average width of the voids is within the above range, it is easier to improve lamination properties. The average width of the voids in the cross-section of the 10 cm range in the central part of the width direction of the composite film represents the average value of the void widths of all voids present in the cross-section, and can be measured, for example, by the method described in the examples.

[0080] In one embodiment of the present invention, when the cross-section of the composite film in the width direction of the composite film is observed with a microscope in a 10 cm range in the central part of the width direction, it has a plurality of adhesive parts and voids with two adjacent adhesive parts at both ends, and the average height of the voids is preferably 0.1 μm or more, more preferably 1 μm or more, even more preferably 3 μm or more, even more preferably 5 μm or more, particularly preferably 7 μm or more, particularly more preferably 9 μm or more, extremely preferably 10 μm or more, preferably 50 μm or less, more preferably 45 μm or less, even more preferably 42 μm or less, and even more preferably 40 μm or less. When the average height of the voids is within the above range, it is easier to improve lamination properties. The average height of the voids in the cross-section of the width direction of the composite film in a 10 cm range in the central part of the width direction represents the average value of the void heights of 10 consecutive voids in the cross-section, and can be measured, for example, by the method described in the examples. The average width and height of the voids can be adjusted to the above range by appropriately adjusting the composition of the resin film (X) and substrate (Y), for example, the type and content of resins and additives contained in the resin film (X) and substrate (Y); the surface roughness and void size of the resin film (X) and substrate (Y) before composite formation (for example, before the heat compression process); the manufacturing conditions of the resin film (X) and substrate (Y); and the manufacturing conditions of the composite film. For example, the above range can be adjusted by using the above preferred resins and functional Z as the resin film (X) and substrate (Y), and by appropriately adjusting the surface temperature and linear pressure of the roll in the manufacturing conditions of the composite film described later.

[0081] In the composite film of the present invention, the adhesion force between surface B of the resin film (X) and the substrate (Y) is 0.2 N / cm or more. Preferably, the adhesion force is 0.3 N / cm or more, more preferably 0.5 N / cm or more, even more preferably 1.0 N / cm or more, even more preferably 1.3 N / cm or more, particularly preferably 1.5 N / cm or more, and particularly more preferably 1.8 N / cm or more. When the adhesion force is above the lower limit of the above, it is easier to improve process passability. Furthermore, the upper limit of the adhesion force is not particularly limited and may be, for example, 30 N / cm or less or 20 N / cm or less. The adhesion force between surface B of the resin film (X) and the substrate (Y) indicates the peel strength between surface B of the resin film (X) and the substrate (Y), and can be measured by the peel test described in JIS K6854-3, for example, by the method described in the examples.

[0082] The thickness of the composite film of the present invention is preferably 55 μm or more, more preferably 120 μm or more, even more preferably 350 μm or more, even more preferably 500 μm or more, particularly preferably 600 μm or more, preferably 2000 μm or less, more preferably 1500 μm or less, and even more preferably 1200 μm or less. When the thickness of the composite film is within the above range, it is easier to improve lamination properties, process passability, and puncture resistance. The above thickness can be measured using a thickness gauge or a laser microscope.

[0083] The composite film of the present invention may include layers other than the resin film (X) and the substrate (Y). Examples of these other layers include an adhesive layer (U), an infrared reflective layer, an ultraviolet reflective layer, a color correction layer, an infrared absorbing layer, an ultraviolet absorbing layer, a fluorescent / emissive layer, a sound insulation layer, an electrochromic layer, a thermochromic layer, a photochromic layer, a decorative layer, or a high modulus layer. These other layers can be used individually or in combination of two or more types.

[0084] The adhesive layer (U) may contain a resin and optionally additives. Examples of resins include acrylic resin, urethane resin, epoxy resin, vinyl acetate resin, ethylene-vinyl acetate resin, vinyl chloride resin, silicone resin, nitrile cellulose resin, phenolic resin, polyvinyl alcohol resin, polyvinyl butyral resin, melamine resin, and styrene resin. Among these, polyvinyl butyral resin is preferred from the viewpoint of easily improving adhesion. The polyvinyl butyral resin exemplified above can be suitably used as the polyvinyl butyral resin.

[0085] In one embodiment of the present invention, the composite film of the present invention includes an adhesive layer (U), and from the viewpoint of laminated glass formation, the adhesive layer (U) is preferably adjacent to the resin film (X) or the substrate (Y), and is preferably laminated on the surface of either of the surfaces that is not in contact with the resin film.

[0086] The layer structure of the composite film of the present invention is not particularly limited as long as it includes a resin film (X) and a substrate (Y), but it is preferable to have one of the following layer structures in which layers are laminated in the order below. Such a layer structure makes it easier to improve the lamination and process passability of the composite film of the present invention. When the substrate (Y) is a substrate that includes a substrate layer (Y') and a functional layer having function Z, the substrate layer (Y') is denoted as Y' and the functional layer as Z. When the substrate (Y) is a substrate that includes a substrate layer (Y") having function Z, the substrate layer (Y") is denoted as Y''. Also, the adhesive layer is denoted as U and the resin film (X) as X. X / Y", X / Z / Y', X / Z / Y' / U, X / Y' / Z, X / Y' / Z / U, X / Z / Y' / Z, / Z / Y', U / Z / Y' / X / Z / Y', U / Y' / Z / X / Z / Y' / U, U / Z / Y' / X / Z / Y' / U, Z / Y' / X / Y' / Z, U / Y' / Z / X / Y' / Z, U / Z / Y' / X / Y' / Z / U, Z / Y' / Z / X / Z / Y', Z / Y' / Z / X / Y' / Z, U / Z / Y' / Z / X / Z / Y', U / Z / Y' / Z / X / Y' / Z, U / Z / Y' / Z / X / Z / Y' / U, U / Z / Y' / Z / X / Y' / Z / U, Z / Y' / Z / X / Z / Y' / Z, U / Z / Y' / Z / X / Z / Y' / Z, U / Z / Y' / Z / X / Z / Y' / Z / U, and a layered structure in which two or more of these are laminated via X. Furthermore, other layers may be included between the layers of these layer configurations. Also, if the composite film includes two or more resin films (X), each resin film (X) may be the same or different. The same applies when the composite film includes two or more base layers (Y'), base layers (Y"), functional Z layers, and adhesive layers (U).

[0087] [Method for manufacturing composite films] The method for manufacturing the composite film of the present invention is not particularly limited, but a preferred method includes a heat-sealing step in which a raw material composite film, which is made by layering at least a resin film (X) and a substrate (Y) having function Z, is passed between a first roll and a second roll in an orientation such that the resin film (X) is closer to the first roll than the substrate (Y). Including such a heat-sealing step makes it easier to manufacture a composite film with excellent lamination properties and process passability.

[0088] The raw material composite film is a film obtained by layering at least the resin film (X) and a substrate (Y) having the function Z. When manufacturing a composite film that includes other layers such as an adhesive layer (U), the other layers can be laminated to achieve the desired layer configuration. Furthermore, a protective film may be laminated on one or both sides of the raw material composite film from the viewpoint of suppressing defects during the manufacturing process. Examples of protective films include polyester resin films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resin films such as polyethylene and polypropylene films; and acrylic resin films. The protective film may also have an adhesive layer. From the viewpoint of heat resistance, polyester resin films are preferred.

[0089] In the thermocompression bonding process, the resin film (X) is passed between the first and second rolls in an orientation such that it is closer to the first roll than the substrate (Y). In the thermocompression bonding process, the following equation (2): 20 <T1-T2<140 (2) [In the formula, T1 represents the surface temperature (°C) of the first roll, and T2 represents the surface temperature (°C) of the second roll.] It is preferable that the following conditions are met. When the surface temperature of the first roll and the surface temperature of the second roll satisfy the relationship given by equation (2), it is easier to manufacture a composite film with excellent laminating properties and processability.

[0090] T1-T2 is preferably 25°C or higher, more preferably 30°C or higher, even more preferably 40°C or higher, even more preferably 45°C or higher, preferably 130°C or lower, more preferably 115°C, even more preferably 100°C or lower, even more preferably 80°C or lower, particularly preferably 65°C or lower, and particularly more preferably 60°C or lower. When T1-T2 is within the above range, the lamination and processability of the resulting composite film are easily improved.

[0091] T1 is preferably 180°C or lower, more preferably 150°C or lower, even more preferably 130°C or lower, even more preferably 110°C or lower, particularly preferably 90°C or lower, preferably 40°C or higher, more preferably 50°C or higher, even more preferably 60°C or higher, and even more preferably 70°C or higher. When T1 is below the above upper limit, lamination is easily improved, and when T1 is above the above lower limit, process passability is easily improved.

[0092] T2 is preferably 160°C or lower, more preferably 130°C or lower, even more preferably 110°C or lower, even more preferably 80°C or lower, particularly preferably 60°C or lower, particularly more preferably 50°C or lower, preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, even more preferably 20°C or higher, and particularly preferably 25°C or higher. When T2 is below the above upper limit, lamination is easily improved, and when T2 is above the above lower limit, process passability is easily improved.

[0093] In the heat-sealing process, it is preferable to apply a linear pressure of 0.01 MPa or more and less than 2.0 MPa when the raw material composite film passes between the first and second rolls. More preferably, this linear pressure is 0.05 MPa or more, even more preferably 0.1 MPa or more, even more preferably 1.5 MPa or less, even more preferably 1.0 MPa or less, even more preferably 0.5 MPa or less, and particularly preferably 0.35 MPa or less. When the linear pressure is within the above range, it is easier to improve the lamination and processability of the resulting composite film.

[0094] In the heat-sealing process, the speed at which the raw material composite film passes between the first and second rolls is preferably 0.01 m / min or more, more preferably 0.05 m / min or more, even more preferably 0.1 m / min or more, particularly preferably 0.2 m / min or more, preferably 2.0 m / min or less, more preferably 1.5 m / min or less, even more preferably 1.0 m / min or less, and even more preferably 0.8 m / min or less. When the speed is within the above range, it is easier to improve the laminating properties and process passability of the resulting composite film.

[0095] The equipment used in the heat-sealing process can be conventional equipment used in a roll-to-roll system. Furthermore, if a protective film is laminated on one or both sides of the raw material composite film, the composite film can be obtained by peeling off the protective film after the heat-sealing process.

[0096] [roll] The present invention includes a roll on which the composite film of the present invention is wound. Preferably, the roll of the present invention is made by winding the elongated composite film into a roll shape. Elongated refers to a film in which the length direction is greater than the width direction. The size of the roll of the present invention is not particularly limited, but the length of the composite film is, for example, 100 to 4000 m, and the width of the composite film is, for example, 300 to 1800 mm. Because the roll of the present invention includes the composite film, delamination between the resin film (X) and the substrate (Y) can be effectively suppressed when winding it into a roll shape. Furthermore, since the roll of the present invention has excellent laminating properties when making laminated glass, even if the resulting laminated glass is exposed to a high-temperature environment, the occurrence of appearance defects such as air bubbles can be effectively suppressed or prevented.

[0097] The roll of the present invention may contain paper or film other than the composite film. The film is not particularly limited and conventional films can be used, such as anti-blocking films, anti-static films, and protective films. In one embodiment of the present invention, from the viewpoint of effectively preventing blocking, the roll of the present invention includes a lamination sheet or an anti-blocking film, and preferably the composite film is wound together with the lamination sheet or anti-blocking film.

[0098] [Interlayers for laminated glass and laminated glass] The present invention includes an interlayer for laminated glass, which comprises the composite film of the present invention. Because the interlayer for laminated glass of the present invention comprises the composite film, it can effectively prevent delamination between layers and has excellent workability and lamination properties during the manufacture of laminated glass. The interlayer for laminated glass may contain films other than the composite film. The film is not particularly limited, and conventional films can be used.

[0099] The present invention includes laminated glass in which the interlayer for laminated glass of the present invention is sandwiched between two or more sheets of glass. Because the laminated glass of the present invention includes the interlayer for laminated glass containing the composite film of the present invention, it exhibits excellent degassing properties during the manufacturing of the laminated glass, and can effectively suppress or prevent the occurrence of appearance defects such as bubbles even when exposed to high-temperature environments.

[0100] Examples of glass materials include, from the viewpoint of transparency, weather resistance, and mechanical strength, inorganic glass; or organic glass such as methacrylic resin sheets, polycarbonate resin sheets, polystyrene resin sheets, polyester resin sheets, or polycycloolefin resin sheets; more preferably inorganic glass, methacrylic resin sheets, or polycarbonate resin sheets, and particularly preferably inorganic glass. Examples of inorganic glass include float glass, tempered glass, semi-tempered glass, chemically strengthened glass, green glass, or quartz glass.

[0101] In a laminated glass according to one embodiment of the present invention, if the substrate (Y) having function Z includes a conductive layer (or conductive structure), the conductive layer may be in contact with the glass. However, if the conductive layer is in direct contact with the glass, the sealing of the conductive layer may be insufficient, allowing moisture to penetrate and cause corrosion of the conductive layer, or air may remain during the manufacturing of the laminated glass, leading to the retention of air bubbles or peeling. Therefore, an adhesive layer (U) may be used partially or entirely in areas where sealing is insufficient. Furthermore, since moisture may penetrate from the edges of the laminated glass and cause corrosion of the conductive layer, it is preferable that the conductive layer be positioned at least 1 cm inward from the edges of the laminated glass. Moreover, in the laminated glass of the present invention, the distance between the conductive layer and the inner surface of at least one of the glasses is preferably less than 200 μm, more preferably 100 μm or less, and even more preferably 50 μm or less. When the distance between the conductive layer and the inner surface of at least one of the glasses is within the above range, the heating efficiency of the glass surface is improved, and high heat generation can be obtained.

[0102] The layer configuration of the laminated glass of the present invention includes a layer configuration in which glass is laminated on both surfaces of the layer configuration described in the <Composite Film> section.

[0103] The laminated glass of the present invention can be used as laminated glass in buildings or vehicles. Vehicle glass refers to windshields, rear windows, roof windows, or side windows, etc., for vehicles such as trains, trams, automobiles, ships, or aircraft.

[0104] In a laminated glass according to one embodiment of the present invention, if the resin film (X) and / or substrate (Y) contain a plasticizer, the plasticizer usually migrates over time to the other layer that does not contain a plasticizer or to the other layer that contains a relatively small amount of plasticizer, so that the amount of plasticizer contained in the resin film (X) and the amount of plasticizer contained in the substrate (Y) become approximately the same. In the present invention, this average amount of plasticizer is preferably 18 to 35% by mass, more preferably 20 to 30% by mass, and particularly preferably 25 to 29% by mass. When the average amount of plasticizer is within the above range, desired properties of the laminated glass are more easily obtained, such as mitigating the impact on the head of a person riding in the vehicle during a collision. The average amount of plasticizer can be calculated after the plasticizer migration according to the following formula.

number

[0105] The average amount of plasticizer can be adjusted to within the above range by adjusting the amount of plasticizer contained in the resin film (X), the thickness of the resin film (X), the amount of plasticizer contained in the substrate (Y), and the thickness of the substrate (Y).

[0106] The laminated glass of the present invention can be manufactured by methods known to those skilled in the art. For example, the composite film can be placed on top of a glass, another glass can be placed on top of that, and then the composite film can be fused to the glass, either entirely or locally, by raising the temperature in a preliminary bonding step, and then the process can be carried out in an autoclave to produce the laminated glass.

[0107] The above-mentioned preliminary crimping process can be described as a method of degassing under reduced pressure using a vacuum bag, vacuum ring, or vacuum laminator, a method of degassing using a nip roll, or a method of compression molding at high temperature, from the viewpoint of removing excess air or performing light bonding between adjacent layers.

[0108] For example, the vacuum bag method or vacuum ring method described in EP 1235683 B1 is, for example, approximately 2 × 10 4 The procedure is performed at Pa and 130-145°C.

[0109] A vacuum laminator consists of a heatable and vacuum chamber, in which laminated glass is formed within a time frame of approximately 20 to 60 minutes. Typically, the pressure range is 1 Pa to 3 × 10⁻¹⁶. 4 A reduced pressure of Pa and a temperature of 100°C to 200°C, especially 130°C to 160°C, are effective. When using a vacuum laminator, autoclaving may not be necessary depending on the temperature and pressure.

[0110] Autoclave processing is, for example, about 1 x 10 6 Pa ~ approx. 1.5×10 6 The procedure is carried out at a pressure of Pa and a temperature of approximately 100°C to 145°C for about 20 minutes to 2 hours. [Examples]

[0111] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by such examples.

[0112] [Evaluation items and evaluation methods] <Measurement of Tensile Storage Modulus> The tensile storage modulus E'(40) of the polyvinyl butyral resin film (substrate layer) contained in the substrate (Y) used in the examples and comparative examples was measured by the following method. A polyvinyl butyral resin film (substrate layer) contained in the substrate (Y) was cut to dimensions of 3 mm in width and 3 cm in length to prepare a sample for dynamic viscoelasticity measurement. Using a dynamic viscoelasticity analyzer (Rheogel-E4000, manufactured by UBM Co., Ltd.), analysis was performed with a 20 mm chuck distance, a frequency of 0.3 Hz, automatic strain control (10 μm, 0.05%), automatic static load control (minimum static load 25 g, automatic control value 200%), a heating rate of 3 °C / min from -100 °C to 140 °C, and in tensile mode.

[0113] <Measurement of average value of ten-point average roughness (Rz) and adhesion strength> In the composite films obtained in the examples and comparative examples, the center point was taken from the midpoint of the substrate Y in the width direction. From this midpoint, five strips of the composite film were cut out, each 10 mm wide and 200 mm long, in a continuous manner in the width direction (i.e., within a 50 mm area in the midpoint). These five samples (test pieces) were designated A, B, C (midpoint), D, and E, respectively. For the central sample C, a peel test described in JIS K6854-3 was performed using an Autograph (manufactured by Shimadzu Corporation, "AG-IS") under the conditions of a chuck distance of 50 mm and a test speed of 100 mm / min. The peel strength between the resin film (X) and the substrate (Y) was defined as the adhesion force (N / cm). After peeling the resin film (X) from the substrate (Y), the ten-point average roughness was measured using a surface roughness meter on surfaces A and B of the peeled resin film (X), and on the surface of the substrate (Y) that was not in contact with the resin film (X), in accordance with JIS B0601:1994, under the conditions of λc = 0.8 mm, λs = 2.5 μm, and 0.25 mm / s. Here, for samples B, C, and D, the ten-point average roughness was measured at five arbitrary locations on the sample surface, and the average value of these measurements was taken as the average ten-point average roughness Rz. In Example 5, Comparative Example 1, and Comparative Example 2, instead of the surface of the substrate (Y) that was not in contact with the resin film (X), the ten-point average roughness was measured on the surface of the adhesive layer (U) that was not in contact with the substrate (Y), using the method described above. In Example 3, instead of measuring the ten-point average roughness of the surface of the substrate (Y) that is not in contact with the resin film (X) using the method described above, the thickness of the conductive structure was measured using a microscope (Keyence Corporation, "VHX-5000", 200x magnification, coaxial incident light) and is shown in Table 1.

[0114] <Measurement of average width and average height of voids> The composite film obtained in the examples and comparative examples was cut into strips of 10 cm in width (i.e., a 10 cm range in the center of the width direction), with the center of the width direction of the composite film as the center point. The cut strips were then held in a sample holder so that the cross-sectional portion corresponding to the width direction could be observed, and measured with a microscope (Keyence Corporation, "VHX-5000", 200x magnification, coaxial reflected light). At the two adhesive parts that form both ends of the dark area, which is a void, between surface B of the resin film (X) and layer Z in the substrate (Y), the distance from the center of one adhesive part to the center of the other adhesive part (distance between the two adhesive parts) was measured and defined as the void width of one void. It was then confirmed that the void width of all voids present in the 10 cm cross-section in the width direction of the strip (i.e., a 10 cm range in the center of the width direction) was 2.0 mm or less. The average value of the void widths of all these voids was defined as the "average void width" of the composite film. Furthermore, the distance between surface B of the resin film (X) and layer Z in the substrate (Y) at the center of a single void was defined as the void height in that void, and the average value of the void heights in 10 consecutive voids was defined as the "average void height" of the composite film.

[0115] <Measuring thickness> The thickness of the resin film, substrate, and composite film was determined by taking the average value measured every 3 cm within a 10 cm width range using a constant-pressure thickness measuring instrument conforming to JIS K6250.

[0116] <Measurement of acetalization degree and vinyl acetate unit content> The degree of acetalization and vinyl acetate unit content of the polyvinyl butyral resin used in the examples and comparative examples were measured in accordance with JIS K 6726 "Test Method for Polyvinyl Alcohol".

[0117] <Viscosity measurement of polyvinyl butyral resin> The viscosity of the polyvinyl butyral resins used in the examples and comparative examples was determined by adding each polyvinyl acetal resin to a toluene / ethanol mixed solution to a concentration of 10% by mass, dissolving it, and measuring the viscosity of the resulting solution using a Brookfield type (Type B) viscometer at 20°C and 30 rpm.

[0118] <Laminating properties> The composite films obtained in the examples and comparative examples were laminated between two sheets of glass measuring 300 mm in length, 300 mm in width, and 2 mm in thickness, placed in a vacuum bag, and left to stand at 100°C for 30 minutes while under vacuum. The contents were removed from the vacuum bag and then left to stand in an autoclave at 140°C for 60 minutes to obtain laminated glass. Next, the obtained laminated glass was visually inspected. Furthermore, after sequential heat treatment in a constant temperature bath at 100°C for 16 hours, 110°C for 1 hour, 120°C for 1 hour, 130°C for 1 hour, 140°C for 1 hour, and 150°C for 1 hour, the area excluding the 10 mm edge of the glass was visually inspected for the occurrence of bubbles and evaluated according to the following criteria. A: No external defects such as bubbles were observed after autoclaving or heat treatment. B: No external defects such as bubbles were observed after autoclaving and after heating at 140°C, but five or fewer defects were found after heating at 150°C. C: No external defects such as bubbles are observed after autoclaving, but external defects can be confirmed after heating at 100°C.

[0119] <Process passability> Using an adhesive roll cleaner ("Elep Cleaner SDR-10-160" manufactured by Nitto Denko Corporation), the surface of the resin film (X) of the composite film obtained in the examples and comparative examples was passed over with a hand roller. The evaluation was as follows: if no interfacial delamination occurred between the resin film (X) and the functional layer substrate (Y) of the composite film, it was evaluated as A; if partial delamination occurred, it was evaluated as B; and if delamination occurred, it was evaluated as C.

[0120] [Example 1] 72% by mass of polyvinyl butyral resin and 28% by mass of triethylene glycol-bis-(2-ethylhexanoate), which have an acetalization degree of 69-71 mol%, a vinyl acetate unit content of 1 mol% or less, and a viscosity of 1400-1500 mPa·s in a toluene / ethanol = 1 / 1 solution with a concentration of 10% by mass, were melt-kneaded in a twin-screw extruder and extruded into a film from a T-die to obtain a plasticized polyvinyl butyral resin film with an average value of ten-point average roughness (Rz) of 25 μm and a thickness of 760 μm, which was used as resin film (X).

[0121] Polyvinyl butyral resin (A) with an acetalization degree of 69-71 mol%, vinyl acetate unit content of 1 mol% or less, and a viscosity of 150-160 mPa·s in a 10% by mass toluene / ethanol = 1 / 1 solution, and polyvinyl butyral resin (B) with an acetalization degree of 69-71 mol%, vinyl acetate unit content of 1 mol% or less, and a viscosity of 1400-1500 mPa·s in a 10% by mass toluene / ethanol = 1 / 1 solution, were melt-kneaded in a ratio of 75:25, extruded into strands, and pelletized. The obtained pellets were melt-extruded using a single-screw extruder and a T-die under the following conditions, and a polyvinyl butyral resin film was obtained using a metal elastic roll and a rubber elastic roll. The obtained polyvinyl butyral resin film had a smooth surface on one side, an average value Rz of the ten-point average roughness of the other surface of 7.1 μm, and a thickness of 52 μm. Melt extrusion conditions Extruder setting temperature (melting temperature of resin material): 200℃, T-die width: 500mm, T-die lip opening: 0.5mm, Molten resin discharge rate from T-die: 15 kg / h

[0122] A 12 μm thick copper foil, with one side blackened, was placed on the polyvinyl butyral resin film obtained by the above method, with the blackened side (hereinafter sometimes referred to as the blackened side) in contact with the smooth surface of the polyvinyl butyral resin film. Next, the laminate of the polyvinyl butyral resin film and copper foil was sandwiched between 50 μm thick PET films, passed through a heat-sealing roll set to 120°C (pressure: 0.2 MPa, speed: 0.5 m / min), and then the PET film was removed to obtain a polyvinyl butyral resin film with the copper foil laminated on top.

[0123] After laminating a dry film resist onto the copper foil of the obtained polyvinyl butyral resin film with laminated copper foil, an etched resistance pattern was formed using photolithography. Next, the polyvinyl butyral resin film with laminated copper foil and the etched resistance pattern formed on it was immersed in a copper etching solution to form a conductive structure. Then, the remaining photoresist layer was removed by conventional methods, and a conductive structure, which is an etched copper foil structure, was formed on the surface of the polyvinyl butyral resin film. The conductive structure was formed such that copper wires (main conductive fine wires) with a line width of 10 μm were arranged in a corrugated pattern at 2.0 mm intervals inside a square of 18 cm by 18 cm in length and width, so that the ends of each copper wire reach the top and bottom edges of the square. Simultaneously with the formation of this conductive structure, copper wires with a width of 20 mm and a length of 18 cm, corresponding to main busbars, were formed at the top and bottom edges of the square to electrically connect with the ends of each copper wire. A conductive structure was fabricated by laminating a 50 cm long adhesive copper tape (3M, "1245") onto the main busbar. This resulted in a polyvinyl butyral resin film having a conductive structure on its surface, i.e., a substrate (Y) consisting of a substrate layer having a conductive structure. This substrate (Y) is a substrate having the function Z of conductivity. The average value Rz of the ten-point average roughness of the surface of the substrate (Y) that does not have a conductive structure was 5.1 μm.

[0124] The obtained resin film (X) and substrate (Y) were laminated with the conductive structure in contact with the resin film (X), sandwiched between 50 μm thick PET films, and passed between thermocompression rolls set to 80°C on the resin film (X) side and 30°C on the substrate (Y) side (pressure: 0.2 MPa, speed: 0.3 m / min). After removing the PET films, a composite film was obtained. The thickness of the obtained composite film was 810 μm, the thickness of the resin film (X) in the composite film was 760 μm, and the thickness of the substrate (Y) was 50 μm.

[0125] [Example 2] In the preparation of the base material (Y), a resin film (X), a polyvinyl butyral resin film, a base material (Y), and a composite film were obtained in the same manner as in Example 1, except that 95% by mass of a mixture of polyvinyl butyral resins (A) and (B) (A:B=75:25) and 5% by mass of triethylene glycol-bis-(2-ethylhexanoate) were melt-kneaded, extruded into strands, and pelletized. Before lamination with copper foil, the polyvinyl butyral resin film had one smooth surface, the average value Rz of the ten-point average roughness of the other surface was 7.2 μm, and the thickness was 52 μm. Before lamination with resin film (X), the average value Rz of the ten-point average roughness of the surface of the base material (Y) that did not have a conductive structure was 5.1 μm. The thickness of the obtained composite film was 810 μm, and the thickness of the base material (Y) in the composite film was 50 μm.

[0126] [Example 3] In the preparation of the composite film, the resin film (X) and the substrate (Y) were laminated in the same manner as in Example 1, except that the conductive structure was not in contact with the resin film (X). A resin film (X), a polyvinyl butyral resin film, a substrate (Y), and a composite film were obtained by the same method as in Example 1. The thickness of the obtained composite film was 810 μm, the thickness of the resin film (X) in the composite film was 760 μm, and the thickness of the substrate (Y) was 50 μm.

[0127] [Example 4] In the preparation of the composite film, the resin film (X), polyvinyl butyral resin film, substrate (Y), and composite film were obtained in the same manner as in Example 1, except that the resin film (X) side was passed between heat-sealing rolls set to 100°C and the substrate (Y) side to 30°C (pressure: 0.4 MPa, speed: 0.3 m / min). The thickness of the obtained composite film was 805 μm, the thickness of the resin film (X) in the composite film was 777 μm, and the thickness of the substrate (Y) was 48 μm.

[0128] [Example 5] 99.7% by mass of polymethyl methacrylate (hereinafter sometimes referred to as PMMA) film (manufactured by Kuraray Co., Ltd., "PARAPURE® JS") and 0.3% by mass of tin-doped indium oxide (hereinafter sometimes referred to as ITO) were melt-kneaded in a twin-screw extruder, extruded into strands, and pelletized. The obtained pellets were melt-extruded using a single-screw extruder and a T-die, and a PMMA film was produced using a metal elastic roll. The PMMA film was smooth on both sides and had a thickness of 100 μm. The PMMA film is a substrate (Y) consisting of a substrate layer having infrared absorption properties, that is, a substrate (Y) having the function Z of infrared absorption.

[0129] Next, a 10% by mass ethanol solution of polyvinyl butyral resin (manufactured by Kuraray Co., Ltd., "Mowital® B60H") was prepared and applied to one side of the substrate (Y) to a thickness of 20 μm, and then dried. Subsequently, a substrate (Y) consisting of a substrate layer with an adhesive layer (U) laminated on one side was prepared using an embossing roll. The average value Rz of the ten-point average roughness of the side of the substrate (Y) without the adhesive layer (U) was 5.0 μm. After preparing a resin film (X) in the same manner as in Example 1, the resin film (X) and a substrate (Y) having an adhesive layer (U) were laminated in the order X / Y / U, sandwiched between 50 μm thick PET films, and passed between thermocompression rolls set to 140°C on the resin film (X) side and 30°C on the adhesive layer (U) side (pressure: 0.4 MPa, speed: 0.3 m / min). After removing the PET film, a composite film was obtained. The thickness of the obtained composite film was 870 μm, the thickness of the resin film (X) in the composite film was 750 μm, and the total thickness of the substrate (Y) and adhesive layer (U) was 120 μm.

[0130] [Comparative Example 1] A composite film was obtained in the same manner as in Example 5, except that the resin film (X) side was set to 80°C and the adhesive layer (U) side to 30°C, and the film was passed between these heat-sealing rolls (pressure: 0.2 MPa, speed: 0.3 m / min).

[0131] [Comparative Example 2] A composite film was obtained in the same manner as in Example 5, except that a colored PET film (manufactured by Nichiei Shinka Co., Ltd., "Black Coat 50-SN", 50 μm thick) was used as the substrate (Y) having function Z.

[0132] [Comparative Example 3] A composite film was obtained in the same manner as in Example 1, except that the resin film (X) side was set to 140°C and the substrate (Y) side to 100°C and passed between the heat-sealing rolls (pressure: 0.4 MPa, speed: 0.3 m / min).

[0133] Table 1 shows the results of measuring the adhesion strength (N / cm) and evaluating the lamination properties and process passability of the composite films obtained in the examples and comparative examples. Table 1 also shows the results of measuring the type of resin and plasticizer content (mass%) contained in the resin film (X), substrate (Y), and adhesive layer (U), respectively; the tensile storage modulus E' (40) of the substrate layer constituting the substrate (Y); the function Z; the layer structure of the composite film; the average values ​​of the ten-point average roughness of surfaces A and (B) of the resin film (X) (RzA, RzB); the average value of the ten-point average roughness of the substrate (Y) on the surface not in contact with the resin film (X) (RzY), B / A × 100 (%); and the average width (mm) and average height (μm) of the voids in the composite film.

[0134] [Table 1] Furthermore, in the composite films of Examples 1 to 5, the width of all voids present in a 10 cm cross-section in the width direction (i.e., the central 10 cm range in the width direction) was 2.0 mm or less.

[0135] As shown in Table 1, the composite films of Examples 1-3 received an A rating for both lamination and process passability, while the composite films of Examples 4 and 5 received a B rating for lamination and an A rating for process passability. In contrast, Comparative Example 2 received a B rating for both lamination and process passability, while Comparative Examples 1 and 3 received a C rating for one of them. Therefore, the composite film of the present invention can maintain high lamination while possessing excellent process passability. [Explanation of Symbols]

[0136] 1… Resin film 2...Base material 3...Void 4… Close contact area 5…Width of the gap 6… Height of the void

Claims

1. A composite film comprising a resin film (X) and a substrate (Y) having function Z, wherein the resin film (X) has surfaces A and B, and at least an adhesive portion and a void exist between surface B and the substrate (Y), and the adhesion force between surface B and the substrate (Y) is 0.2 N / cm or more. In accordance with JIS B0601:1994, the average value RzB of the ten-point average roughness of surface B measured at any five locations is between 0.1 μm and 50 μm. When a microscope was used to observe a cross-section of the composite film along its width, specifically a 10 cm section in the central part of the width, it was observed that the film had multiple adhering sections and gaps existing at both ends, with two adjacent adhering sections at the ends. More than 90% of all voids have a width of 2.0 mm or less. The average height of the voids is between 0.1 μm and 50 μm. Composite film.

2. The composite film according to claim 1, wherein the base material (Y) includes a base material layer having a tensile storage modulus E'(40) of 0.1 GPa or more at 40°C.

3. Formula (1): 10<RzB×100 / RzA<140 (1) [In the formula, RzA represents the average value of the ten-point average roughness of surface A measured at any five locations in accordance with JIS B0601:1994, and RzB represents the average value of the ten-point average roughness of surface B measured at any five locations in accordance with JIS B0601:1994.] A composite film according to claim 1 or 2, satisfying the requirements.

4. The composite film according to any one of claims 1 to 3, wherein the adhesion force between surface B of the resin film (X) and the substrate (Y) is 1.3 N / cm or more.

5. The composite film according to any one of claims 1 to 4, wherein the base material (Y) comprises at least one selected from the group consisting of polyvinyl acetal resin, ionomer resin, poly(meth)acrylic resin, polyolefin resin, and polycarbonate resin.

6. The composite film according to any one of claims 1 to 5, wherein the amount of plasticizer contained in the base material (Y) is 20% by mass or less.

7. The composite film according to any one of claims 1 to 6, wherein the thickness of the substrate (Y) is 1 μm or more and 100 μm or less.

8. The composite film according to any one of claims 1 to 7, wherein function Z is at least one selected from the group consisting of colorability, light absorption, light reflection, sound insulation, light scattering, luminescence, conductivity, double image prevention, and light transmission.

9. The composite film according to any one of claims 1 to 8, wherein function Z is conductive, and the substrate (Y) comprises at least one selected from the group consisting of gold, silver, copper, metal oxides, organic conductive materials, and carbon compounds.

10. The composite film according to any one of claims 1 to 9, wherein function Z is conductive, and the substrate (Y) has a conductive structure formed by at least one method selected from the group consisting of etching, printing, coating, and vapor deposition.

11. A composite film according to any one of claims 1 to 10, wherein the average value RzA of the ten-point average roughness of surface A measured at any five locations in accordance with JIS B0601:1994 is 0.1 μm or more and 50 μm or less.

12. The composite film according to any one of claims 1 to 11, wherein the average value of the ten-point average roughness measured at any five arbitrary locations on the surface of the substrate (Y) that is not in contact with the resin film (X), in accordance with JIS B0601:1994, is 0.1 μm or more and 20 μm or less.

13. The composite film according to any one of claims 1 to 12, wherein the resin film (X) comprises a polyvinyl acetal resin and / or an ionomer resin.

14. The composite film according to any one of claims 1 to 13, further comprising an adhesive layer (U), wherein the adhesive layer (U) is adjacent to a resin film (X) or a substrate (Y).

15. A composite film according to any one of claims 1 to 14, wherein the base material (Y) is a base material comprising a base material layer (Y') and a functional layer having function Z, or a base material comprising a base material layer (Y'') having function Z, and optionally comprising an adhesive layer (U), wherein the adhesive layer is U, the base material layer (Y') is Y', the base material layer (Y'') is Y'', the functional layer having function Z is Z, and the resin film (X) is X, and the layers are laminated in the following order: X / Y", X / Z / Y', X / Z / Y' / U, X / Y' / Z, X / Y' / Z / U, X / Z / Y' / Z, / Z / Y', U / Z / Y' / X / Z / Y', U / Y' / Z / X / Z / Y' / U, U / Z / Y' / X / Z / Y' / U, Z / Y' / X / Y' / Z, U / Y' / Z / X / Y' / Z, U / Z / Y' / X / Y' / Z / U, Z / Y' / Z / X / Z / Y', Z / Y' / Z / X / Y' / Z, U / Z / Y' / Z / X / Z / Y', U / Z / Y' / Z / X / Y' / Z, U / Z / Y' / Z / X / Z / Y' / U, U / Z / Y' / Z / X / Y' / Z / U, Z / Y' / Z / X / Z / Y' / Z, U / Z / Y' / Z / X / Z / Y' / Z, U / Z / Y' / Z / X / Z / Y' / Z / U, and a layered structure in which two or more of these are laminated via X A composite film having any of the following:

16. An interlayer for laminated glass, comprising the composite film described in any one of claims 1 to 15.

17. A laminated glass in which the interlayer for laminated glass described in claim 16 is sandwiched between two or more sheets of glass.

18. A roll on which the composite film according to any one of claims 1 to 15 is wound.

19. A roll in which the composite film according to any one of claims 1 to 15 is wound together with a laminating sheet or an anti-blocking film.

20. A method for manufacturing a composite film according to any one of claims 1 to 15, comprising a thermocompression bonding step of passing a raw material composite film, which is made by layering at least a resin film (X) and a substrate (Y) having function Z, between a first roll and a second roll in an orientation such that the resin film (X) is closer to the first roll than the substrate (Y), wherein formula (2); 20<T1-T2<140 (2) [In the formula, T1 represents the surface temperature (°C) of the first roll, and T2 represents the surface temperature (°C) of the second roll.] A method to satisfy the requirements.

21. The method according to claim 20, wherein, in the heat-sealing process, when the raw material composite film passes between the first roll and the second roll, pressure is applied with a linear pressure of 0.01 MPa or more and less than 2.0 MPa.

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