Interlayer for laminated glass, and laminated glass

Abstract

The interlayer film for a laminated glass according to the present invention contains at least one graphene-based material selected from the group consisting of graphene and graphite.

Description

Technical Field

[0001] The present invention relates to an interlayer film for laminated glass and a laminated glass having the interlayer film for laminated glass.

Background Art

[0002] Laminated glass is widely used for window glass of various vehicles such as automobiles and window glass of buildings because it is safe with less scattering of glass fragments even when damaged by an external impact. As laminated glass, a structure in which an interlayer film for laminated glass containing a resin component such as polyvinyl acetal resin is interposed between a pair of glasses and integrated is widely known. There is a demand for the interlayer film for laminated glass to be colored black in order to impart light-shielding property, anti-glare property, design property, and heat-shielding property to window glass. Generally, carbon black is often used for coloring black (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, carbon black has insufficient infrared cut performance, and it is difficult to enhance the heat-shielding property of the laminated glass interlayer film with carbon black alone. Furthermore, since carbon black is not achromatic black but has a reddish color, there is room for improvement in terms of design property. Therefore, an object of the present invention is to provide an interlayer film for laminated glass capable of easily enhancing heat-shielding performance and design property.

Means for Solving the Problems

[0005] As a result of intensive studies, the inventors of the present invention have found that the above problems can be solved by using graphene or graphite in the interlayer film for laminated glass, and have completed the following present invention. That is, the present invention provides the following [1] to

[11] . [1] An interlayer film for laminated glass containing at least one graphene-based material selected from the group consisting of graphene and graphite. [2] The interlayer film for laminated glass according to [1] above, wherein the average particle size of the graphene-based material is 40 μm or less. [3] The interlayer film for laminated glass according to [1] or [2] above, wherein the thickness of the graphene-based material is 1 μm or less. [4] The interlayer film for laminated glass according to any one of [1] to [3] above, wherein the degree of oxidation of the graphene-based material is 50% or less. [5] The interlayer film for laminated glass according to any one of [1] to [4] above, wherein the content of the graphene-based material is 0.0005% by mass or more and 1% by mass or less. [6] The interlayer film for laminated glass according to any one of [1] to [5] above, comprising a resin and a colored resin layer containing the graphene-based material. [7] The interlayer film for laminated glass according to [6] above, wherein the colored resin layer contains polyvinyl acetal resin as the resin. [8] Comprising a first resin layer, a second resin layer provided on one surface side of the first resin layer, and a third resin layer provided on the other surface side of the first resin layer, [9] The interlayer film for laminated glass according to [6] or [7] above, wherein the first resin layer is the colored resin layer. [9] The total solar transmittance (Tts) and visible light transmittance (Tv) measured in laminated glass produced by bonding two clear glass plates, each having a thickness of 2.5 mm and measured in accordance with JIS R 3106:1998 with a visible light transmittance of 90.5%, a solar radiation transmittance of 87.3%, and a solar radiation reflectance of 8.3%, through the interlayer film for laminated glass according to any one of [1] to [8] above, satisfy the following formula (1). (Tts-31) / Tv < 0.6 (1)

[10] Two clear glass plates each having a thickness of 2.5 mm and a visible light transmittance of 90.5% measured in accordance with JIS R 3106:1998 and a chroma of 0.6 measured in accordance with JIS Z 8781 are bonded through the above-mentioned laminated glass intermediate film disposed therebetween. The chroma (C) and visible light transmittance (Tv) measured in the laminated glass thus produced satisfy the following formula (2). The laminated glass intermediate film according to any one of the above items [1] to [9]. (C - 16) / Tv < -0.15 (2)

[11] The average particle size of the graphene-based material is 0.001 μm or more and 4 μm or less. The laminated glass intermediate film according to any one of the above items [1] to

[10] .

[12] The average particle size of the graphene-based material is 1 μm or less. The laminated glass intermediate film according to any one of the above items [1] to

[11] .

[13] The thickness of the graphene-based material is 0.001 μm or more and 0.1 μm or less. The laminated glass intermediate film according to any one of the above items [1] to

[12] .

[14] The thickness of the graphene-based material is 0.01 μm or less. The laminated glass intermediate film according to any one of the above items [1] to

[13] .

[15] The degree of oxidation of the graphene-based material is 0.01% or more and 30% or less. The laminated glass intermediate film according to any one of the above items [1] to

[14] .

[16] The degree of oxidation of the graphene-based material is 1% or less. The laminated glass intermediate film according to any one of the above items [1] to

[15] .

[17] The content of the graphene-based material is 0.005% by mass or more and 0.3% by mass or less. The graphene-based material is contained in the entire region of the laminated glass intermediate film. The laminated glass intermediate film according to any one of the above items [1] to

[16] .

[18] The graphene-based material is contained in a partial region of the laminated glass intermediate film. The laminated glass intermediate film according to any one of the above items [1] to

[17] .

[19] The interlayer film for laminated glass according to any one of [1] to

[17] above, wherein the graphene-based material is contained in the entire region of the interlayer film for laminated glass.

[20] The interlayer film for laminated glass according to any one of [1] to

[19] above, comprising a resin and a colored resin layer containing the graphene-based material, and further containing a colorant other than the graphene-based material in the colored resin layer.

[21] The interlayer film for laminated glass according to any one of [1] to

[20] above, comprising a resin and a colored resin layer containing the graphene-based material, wherein the content of the graphene-based material in the colored resin layer is 0.0005% by mass or more and 5% by mass or less.

[22] A laminated glass comprising the interlayer film for laminated glass according to any one of [1] to

[21] above and two glass plates, wherein the interlayer film for laminated glass is disposed between the two glass plates.

Advantages of the Invention

[0006] According to the interlayer film for laminated glass of the present invention, the heat insulation performance and the design property can be easily enhanced.

Brief Description of the Drawings

[0007]

Figure 1

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Figure 9

Mode for Carrying Out the Invention

[0008] <Interlayer Film for Laminated Glass> Hereinafter, the present invention will be described in detail using embodiments. The interlayer film for laminated glass of the present invention (hereinafter sometimes simply referred to as "interlayer film") contains at least one graphene-based material selected from the group consisting of graphene and graphite.

[0009] [Graphene-Based Material] The graphene-based material used in the present invention is graphene or graphite. Graphene or graphite is achromatic black. Therefore, when the interlayer film of the present invention is not used in combination with other colorants or the like, it can be colored black with low chroma. Also, when used in combination with other colorants, the color of the combined colorant can be easily reflected in the interlayer film, which may enhance the designability. Further, since graphene or graphite can increase the infrared absorption rate, it is easy to improve the heat insulation property of the interlayer film.

[0010] Note that graphene generally refers to a single-layer hexagonal lattice structure composed of carbon, while graphite refers to a structure in which multiple layers of hexagonal lattice structures are stacked. However, even if multiple layers of hexagonal lattice structures are stacked, if the number of stacked layers is small (for example, 20 layers or less), it may be referred to as graphene, and the terms "graphene" and "graphite" are not always clearly distinguished and used. Therefore, in this specification, graphene and graphite may be collectively described as graphene-based materials.

[0011] The average particle size of the graphene-based material is, for example, 40 μm or less. By setting the average particle size to 40 μm or less, the dispersibility with respect to the resin constituting the intermediate film can be improved, light scattering by the graphene-based material can be suppressed, and the laminated glass can be made less likely to fog. From the viewpoint of making the intermediate film and the laminated glass less likely to fog, the smaller the average particle size of the graphene-based material, the better. Preferably it is 4 μm or less, more preferably 1 μm or less, still more preferably 0.5 μm or less, even more preferably 0.1 μm or less, even more preferably 0.05 μm or less, and particularly preferably 0.025 μm or less. Also, the lower limit of the average particle size of the graphene-based material is not particularly limited, but from the viewpoint of ease of production, it is, for example, 0.001 μm.

[0012] The thinner the graphene-based material, the more it can suppress scattering at the edge portion, and the less likely the laminated glass is to fog. Also, the fewer the number of layers and the thinner the thickness of the graphene-based material, the less likely it is to have a metallic luster and the easier it is to ensure transparency. Therefore, it is preferable that the thickness of the graphene is below a certain level. From such a viewpoint, the thickness of the graphene material is, for example, 1 μm or less, preferably 0.1 μm or less, more preferably 0.05 μm or less, still more preferably 0.01 μm or less, and even more preferably 0.003 μm or less. Also, if the thickness of the graphene-based material is 0.001 μm or more, the handleability is improved. Note that graphene-based materials are prone to aggregation when they are thin, and folding of graphene may also occur, which may cause cloudiness in laminated glass or the like. However, cloudiness can be prevented by appropriately dispersing them in a resin. The shape of the graphene-based material is not particularly limited and may be spherical, plate-like, or any other shape, but it is preferably plate-like in order to reduce the thickness as described above. The average particle diameter and thickness of graphene are the arithmetic mean values of 30 points measured from a photograph taken with a transmission electron microscope, and the specific measurement method is as described in the examples.

[0013] Graphene may be graphene oxide or reduced graphene. Graphene oxide has oxygen-based functional groups such as oxygen and carboxylic acid on its surface, while reduced graphene does not have oxygen-based functional groups on its surface. Graphene has a higher visible light transmittance and a lower infrared light transmittance, and thus exhibits good heat shielding performance, as the degree of oxidation is lower and the degree of reduction is higher. In addition, as the degree of oxidation is lower, the color tone when added to the intermediate film becomes closer to achromatic from black with a strong red tint, so the design property is also excellent. The same applies to graphite. From the above viewpoints, the degree of oxidation of the graphene-based material is preferably 50% or less, more preferably 30% or less, still more preferably 10% or less, and even more preferably 1% or less. The degree of oxidation in the graphene-based material is not particularly limited, but it may be, for example, 0.01% or more or 0.1% or more. Although the number of functional groups decreases as the degree of oxidation of the graphene-based material decreases, having a degree of oxidation equal to or higher than a certain value can ensure a certain number of functional groups, and the dispersibility in the intermediate film tends to be good as described above. Note that the degree of oxidation of the graphene-based material can be measured from the weight loss when measuring TG-TDA in a nitrogen atmosphere and an oxygen atmosphere.

[0014] The lower the content rate of the graphene-based material in the intermediate film, the less likely it is for the intermediate film to become cloudy. Also, the visible light transmittance (Tv) described later can be adjusted according to the content rate. From such a perspective, the content rate of the graphene-based material in the intermediate film is preferably 5% by mass or less, more preferably 1% by mass or less, still more preferably 0.3% by mass or less, even more preferably 0.1% by mass or less, and particularly preferably 0.05% by mass or less. Also, from the perspective of enhancing the red light absorbency to improve the heat insulation property and also enhancing the design property, the content rate of the graphene-based material in the intermediate film is preferably 0.0005% by mass or more, and more preferably 0.005% by mass or more.

[0015] Note that the content rate of the graphene-based material in the intermediate film means, in both the case where the intermediate film has a single-layer structure and the case where it has a multilayer structure, the content rate of the graphene-based material with respect to the entire single-layer structure or multilayer structure (that is, in the total thickness including the resin layer that does not contain the graphene-based material if any). Also, as described later, in the case of having a non-colored region and a colored region, it means the content rate of the graphene-based material in the colored region. Further, in the case where the content rate changes for each position, such as when the colored region has a gradation region, it is the content rate of the graphene-based material at the position where the content rate of the graphene-based material is the highest. Also, the content rate of graphene in the intermediate film can be measured from the weight loss when measuring TG-TDA.

[0016] The manufacturing method of the graphene-based material is not particularly limited. For example, graphene oxide can be manufactured by the Hummers method. Also, reduced graphene can be obtained by reducing graphene oxide by a known method. Also, graphite can be obtained by exfoliating graphite such as natural graphite, artificial graphite, and expanded graphite. The average particle size of the graphene-based material can be adjusted, for example, by refining graphene or graphite. For example, the average particle size can be reduced by mechanically crushing with a crusher. The thickness can be reduced by dispersing in an appropriate solvent and then irradiating with ultrasonic waves to cause interlayer delamination.

[0017] Whether or not the intermediate film contains a graphene-based material can be detected by an XRD apparatus. Specifically, the intermediate film is placed on a non-reflective Si substrate and measured with an XRD apparatus (Rigaku's "SmartLab"). The measurement conditions are: X-ray light source is Cu Kα line (λ = 0.154 nm), tube voltage is 9 kW (45 kV × 200 mA), optical system is the focusing method (D / TeX), measurement range is 5° to 100°, measurement step is 0.02°, and operation speed is 40 deg / min. Then, the diffraction intensity of 2θ is calculated from the measurement results, and it can be determined that it contains if it has a peak at any of 26.5° ± 0.3, 54.0° ± 0.3, 77.6° ± 0.3°. In the identification / qualitative analysis of diffraction peaks, it is effective to utilize a crystal structure database such as ICDD (JCPDS). Also, the presence or absence of the graphene-based material can be confirmed by observing with a microscope such as a transmission electron microscope. Specifically, an ultra-thin section is cut out from the intermediate film by the microtome method, and observed with a transmission electron microscope ("JEM-2100", manufactured by JEOL Ltd.) under the condition of an acceleration voltage of 200 kV. It can also be determined from the fact that the cross-section of the plate-like particles contained in the ultra-thin section has a stacked structure of carbon hexagonal meshes.

[0018] [Resin layer] The intermediate film of the present invention includes one or more resin layers, and each resin layer contains a resin. The resin used in the resin layer is preferably a thermoplastic resin. By containing a thermoplastic resin, the resin layer is likely to function as an adhesive layer, and the adhesiveness with the glass plate becomes good. In the interlayer film of the present invention, at least one of the plurality of resin layers contains the above-described graphene-based material in addition to the resin. In the specification, a resin layer containing a graphene-based material is referred to as a "colored resin layer", and a resin layer colored only with materials other than the "graphene-based material" is not regarded as a "colored resin layer". In the colored resin layer, the graphene-based material is dispersed in the resin.

[0019] The content of the graphene-based material in the colored resin layer only needs to be such that the content ratio of the graphene-based material in the above interlayer film is within the above range, but preferably 5% by mass or less, more preferably 1% by mass or less, still more preferably 0.5% by mass or less, even more preferably 0.2% by mass or less, and particularly preferably 0.1% by mass or less. Also, the content of the graphene-based material in the colored resin layer is preferably 0.0005% by mass or more, and more preferably 0.005% by mass or more.

[0020] The thermoplastic resin in each resin layer is not particularly limited, and examples thereof include polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ionomer resin, polyurethane resin, thermoplastic elastomer, acrylic resin, acrylic-vinyl acetate copolymer resin, polyvinyl alcohol resin, polyolefin resin, polyvinyl acetate resin, and polystyrene resin. By using these resins, it becomes easier to ensure adhesiveness to the glass plate. In the interlayer film of the present invention, the thermoplastic resin may be used alone or in combination of two or more. Among these, at least one selected from polyvinyl acetal resin and ethylene-vinyl acetate copolymer resin is preferable, and particularly, polyvinyl acetal resin is more preferable from the viewpoint of exhibiting excellent adhesiveness to glass when used in combination with a plasticizer. Therefore, the resin in the above colored resin layer is also preferably at least one selected from polyvinyl acetal resin and ethylene-vinyl acetate copolymer resin, and polyvinyl acetal resin is more preferable.

[0021] In addition, when having a plurality of resin layers, the resin constituting each resin layer may be appropriately selected from the resins listed above. Also, the resins constituting each resin layer may be different from each other, but are preferably the same as each other. Therefore, when having a plurality of resin layers, it is preferable that all of the resins constituting each resin layer are polyvinyl acetal resin or ethylene-vinyl acetate copolymer resin, and it is more preferable that all of them are polyvinyl acetal resin.

[0022] (Polyvinyl acetal resin) The polyvinyl acetal resin is not particularly limited as long as it is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The aldehyde is not particularly limited, but generally, aldehydes having 1 to 10 carbon atoms are preferably used. The aldehydes having 1 to 10 carbon atoms are not particularly limited, and examples include n-butyl aldehyde, isobutyl aldehyde, n-valeraldehyde, 2-ethylbutyl aldehyde, n-hexyl aldehyde, n-octyl aldehyde, n-nonyl aldehyde, n-decyl aldehyde, formaldehyde, acetaldehyde, benzaldehyde and the like. These aldehydes may be used alone or in combination of two or more. Among the above, n-butyl aldehyde, n-hexyl aldehyde, and n-valeraldehyde are preferable, and n-butyl aldehyde is more preferable. Therefore, the polyvinyl acetal resin is preferably polyvinyl butyral resin.

[0023] Polyvinyl alcohol (PVA) can be obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The saponification degree of polyvinyl alcohol is generally 70 to 99.9 mol%. The polyvinyl acetal resin may be used alone or in combination of two or more. The average degree of polymerization of PVA is preferably 200 or more, more preferably 500 or more, still more preferably 1000 or more, and even more preferably 1500 or more. When the average degree of polymerization is at least the above lower limit, the penetration resistance of the laminated glass increases. Also, the average degree of polymerization of PVA is preferably 5000 or less, more preferably 4000 or less, still more preferably 3500 or less, and even more preferably 2500 or less. The average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Test Methods for Polyvinyl Alcohol".

[0024] The amount of hydroxyl groups in the polyvinyl acetal resin is preferably 15 mol% or more and preferably 38 mol% or less. By setting the amount of hydroxyl groups to 15 mol% or more, the adhesiveness tends to be good, and it also tends to improve the penetration resistance of the laminated glass. Also, by setting the amount of hydroxyl groups to 38 mol% or less, it is possible to prevent the laminated glass from becoming too hard. From the viewpoint of adhesiveness to the glass plate and the like, the above amount of hydroxyl groups is more preferably 20 mol% or more, and still more preferably 25 mol% or more. Also, the above amount of hydroxyl groups is more preferably 35% or less, and still more preferably 33 mol% or less. When using polyvinyl butyral resin as the polyvinyl acetal resin, from the same viewpoint, the amount of hydroxyl groups is 15 mol% or more, preferably 38 mol% or less, more preferably 20 mol% or more, still more preferably 25 mol% or more, more preferably 35 mol% or less, and still more preferably 33 mol% or less. The amount of hydroxyl groups in the polyvinyl acetal resin is a value obtained by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain and expressing the molar fraction as a percentage. The amount of ethylene groups to which the above hydroxyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Test Methods for Polyvinyl Butyral".

[0025] The degree of acetalization of the above polyvinyl acetal resin is preferably 47 mol% or more, and preferably 85 mol% or less. The degree of acetalization is more preferably 55 mol% or more, still more preferably 60 mol% or more, and also more preferably 80 mol% or less, still more preferably 75 mol% or less. The degree of acetalization means the degree of butyralization when the acetal group is a butyral group and the polyvinyl acetal resin (A) is a polyvinyl butyral resin.

[0026] The degree of acetalization is a value obtained by dividing, by the total amount of ethylene groups in the main chain, the value obtained by subtracting the amount of ethylene groups to which a hydroxyl group is bonded and the amount of ethylene groups to which an acetyl group is bonded from the total amount of ethylene groups in the main chain, and expressing the resulting mole fraction as a percentage. The degree of acetalization (degree of butyralization) may be calculated from the results measured by a method conforming to, for example, JIS K6728 "Test Methods for Polyvinyl Butyral".

[0027] The degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, and even more preferably 2 mol% or less. When the degree of acetylation is below the above upper limit, the moisture resistance of the intermediate film and the laminated glass is increased. The degree of acetylation is not particularly limited, but is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more. The degree of acetylation is a value obtained by expressing, as a percentage, the mole fraction obtained by dividing the amount of ethylene groups to which an acetyl group is bonded by the total amount of ethylene groups in the main chain. The amount of ethylene groups to which the acetyl group is bonded can be measured, for example, in accordance with JIS K6728 "Test Methods for Polyvinyl Butyral".

[0028] (Ethylene-vinyl acetate copolymer resin) As the ethylene-vinyl acetate copolymer resin, a non-crosslinked ethylene-vinyl acetate copolymer resin or a high-temperature crosslinked ethylene-vinyl acetate copolymer resin may be used. Further, as the ethylene-vinyl acetate copolymer resin, ethylene-vinyl acetate modified resin such as saponified ethylene-vinyl acetate copolymer and hydrolyzate of ethylene-vinyl acetate can also be used. The vinyl acetate content of the ethylene-vinyl acetate copolymer resin, which is preferably 10 to 50% by mass, more preferably 20 to 40% by mass, is measured in accordance with JIS K 6730 "Test Methods for Ethylene-Vinyl Acetate Resins" or JIS K 6924-2:1997. By setting the vinyl acetate content to be not less than these lower limit values, the adhesiveness to glass increases, and the penetration resistance of the laminated glass tends to be good. Also, by setting the vinyl acetate content to be not more than these upper limit values, the breaking strength of the interlayer film increases, and the impact resistance of the laminated glass becomes good.

[0029] (Ionomer resin) There is no particular limitation on the ionomer resin, and various ionomer resins can be used. Specifically, ethylene-based ionomers, styrene-based ionomers, perfluorocarbon-based ionomers, telechelic ionomers, polyurethane ionomers, etc. can be mentioned. Among these, ethylene-based ionomers are preferred in terms of the good mechanical strength, durability, transparency, etc. of the laminated glass and the excellent adhesiveness to glass.

[0030] As the ethylene-based ionomer, an ionomer of an ethylene-unsaturated carboxylic acid copolymer is preferably used because of its excellent transparency and toughness. The ethylene-unsaturated carboxylic acid copolymer is a copolymer having at least a structural unit derived from ethylene and a structural unit derived from an unsaturated carboxylic acid, and may have a structural unit derived from another monomer. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, etc., with acrylic acid and methacrylic acid being preferred, and methacrylic acid being particularly preferred. Examples of other monomers include acrylic acid esters, methacrylic acid esters, 1-butene, etc. As for the ethylene-unsaturated carboxylic acid copolymer, when the total constitutional units of the copolymer are 100 mol%, it preferably has 75 to 99 mol% of the constitutional units derived from ethylene and preferably has 1 to 25 mol% of the constitutional units derived from the unsaturated carboxylic acid. The ionomer of the ethylene-unsaturated carboxylic acid copolymer is an ionomer resin obtained by neutralizing or crosslinking at least a part of the carboxyl groups of the ethylene-unsaturated carboxylic acid copolymer with metal ions. The degree of neutralization of the carboxyl groups is usually 1 to 90%, preferably 5 to 85%.

[0031] Examples of the ion source in the ionomer resin include alkali metals such as lithium, sodium, potassium, rubidium, cesium, and polyvalent metals such as magnesium, calcium, zinc, etc., with sodium and zinc being preferred.

[0032] The production method of the ionomer resin is not particularly limited, and it can be produced by a conventionally known production method. For example, when using an ionomer of an ethylene-unsaturated carboxylic acid copolymer as the ionomer resin, for example, ethylene and an unsaturated carboxylic acid are subjected to radical copolymerization under high temperature and high pressure to produce an ethylene-unsaturated carboxylic acid copolymer. Then, by reacting the ethylene-unsaturated carboxylic acid copolymer with a metal compound containing the above ion source, an ionomer of the ethylene-unsaturated carboxylic acid copolymer can be produced.

[0033] (Polyurethane resin) Examples of the polyurethane resin include polyurethanes obtained by reacting an isocyanate compound with a diol compound, and polyurethanes obtained by reacting an isocyanate compound with a diol compound and a chain extender such as a polyamine. The polyurethane resin may contain a sulfur atom. In that case, part or all of the above diol is preferably selected from polythiol and sulfur-containing polyol. The polyurethane resin can improve the adhesiveness to organic glass. Therefore, it is preferably used when the glass plate is organic glass.

[0034] (Thermoplastic elastomer) Examples of the thermoplastic elastomer include styrenic thermoplastic elastomers and aliphatic polyolefins. The styrenic thermoplastic elastomer is not particularly limited, and known ones can be used. The styrenic thermoplastic elastomer generally has a styrene monomer polymer block serving as a hard segment and a conjugated diene compound polymer block or a hydrogenated block thereof serving as a soft segment. Specific examples of the styrenic thermoplastic elastomer include styrene-isoprene diblock copolymer, styrene-butadiene diblock copolymer, styrene-isoprene-styrene triblock copolymer, styrene-butadiene / isoprene-styrene triblock copolymer, styrene-butadiene-styrene triblock copolymer, and hydrogenated products thereof. The above aliphatic polyolefin may be a saturated aliphatic polyolefin or an unsaturated aliphatic polyolefin. The above aliphatic polyolefin may be a polyolefin having a chain olefin as a monomer or a polyolefin having a cyclic olefin as a monomer. From the viewpoint of effectively enhancing the storage stability and sound insulation of the interlayer film, the above aliphatic polyolefin is preferably a saturated aliphatic polyolefin. Examples of the aliphatic polyolefin material include ethylene, propylene, 1-butene, trans-2-butene, cis-2-butene, 1-pentene, trans-2-pentene, cis-2-pentene, 1-hexene, trans-2-hexene, cis-2-hexene, trans-3-hexene, cis-3-hexene, 1-heptene, trans-2-heptene, cis-2-heptene, trans-3-heptene, cis-3-heptene, 1-octene, trans-2-octene, cis-2-octene, trans-3-octene, cis-3-octene, trans-4-octene, cis-4-octene, 1-nonene, trans-2-nonene, cis-2-nonene, trans-3-nonene, cis-3-nonene, trans-4-nonene, cis-4-nonene, 1-decene, trans-2-decene, cis-2-decene, trans-3-decene, cis-3-decene, trans-4-decene, cis-4-decene, trans-5-decene, cis-5-decene, 4-methyl-1-pentene, and vinylcyclohexane, etc.

[0035] (Plasticizer) When each resin layer in the intermediate film contains a thermoplastic resin, it may further contain a plasticizer. By containing a plasticizer, the intermediate film becomes flexible, and as a result, the flexibility of the laminated glass is improved, and the penetration resistance is also improved. Furthermore, it is also possible to exhibit high adhesiveness to the glass plate. It is particularly effective to contain a plasticizer when using a polyvinyl acetal resin as the thermoplastic resin. It is also preferable that the above-described colored resin layer contains a plasticizer, and it is more preferable to contain a polyvinyl acetal resin and a plasticizer. Examples of the plasticizer include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, and phosphoric acid plasticizers such as organic phosphoric acid plasticizers and organic phosphorous acid plasticizers. Among them, organic ester plasticizers are preferable.

[0036] Organic ester plasticizers include, for example, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, 1,2-butylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, diisononyl adipate, heptyl nonyl adipate, dibutyl sebacate, oil-modified sebacic acid alkyd, a mixture of a phosphate ester and an adipic acid ester, a mixed adipic acid ester, and the like. Examples of the mixed adipic acid ester include adipic acid esters prepared from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms. Among the above plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferably used.

[0037] The content of the plasticizer in each resin layer of the interlayer film is not particularly limited, but is preferably 10 parts by mass or more, and preferably 100 parts by mass or less, based on 100 parts by mass of the thermoplastic resin constituting each resin layer. When the content of the plasticizer is 10 parts by mass or more, the laminated glass becomes moderately flexible and the penetration resistance and the like become good. Further, when the content of the plasticizer is 100 parts by mass or less, separation of the plasticizer from the interlayer film is prevented. The content of the plasticizer is more preferably 20 parts by mass or more, still more preferably 30 parts by mass or more, still more preferably 35 parts by mass or more, and more preferably 70 parts by mass or less, still more preferably 63 parts by mass or less. Further, in each resin layer constituting the interlayer film, resin, or resin and plasticizer are the main components, and the total amount of the thermoplastic resin and the plasticizer in each resin layer is usually 70% by mass or more, preferably 80% by mass or more, still more preferably 90% by mass or more and less than 100% by mass, based on the total amount of each resin layer. By setting the total amount to less than 100% by mass, each resin layer can contain additives such as graphene-based materials.

[0038] (Other components) The interlayer film of the present invention may contain at least one of a heat insulating agent and a colorant other than the graphene-based material. These may be contained in any resin layer constituting the interlayer film. The heat insulating agent and the colorant other than the graphene-based material are dispersed in the resin in the resin layer.

[0039] Heat insulating agents other than graphene-based materials include heat insulating particles. The heat insulating particles are made of inorganic materials, and specific examples thereof include metal oxide particles and particles other than metal oxide particles such as lanthanum hexaboride (LaB6) particles. Examples of the metal oxide particles include tin oxide particles such as aluminum-doped tin oxide particles, indium-doped tin oxide particles, and antimony-doped tin oxide particles (ATO particles), zinc oxide particles such as gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), tin-doped zinc oxide particles, and silicon-doped zinc oxide particles, titanium oxide particles such as niobium-doped titanium oxide particles, indium oxide particles such as tin-doped indium oxide particles (ITO particles), sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles (CWO particles), thallium-doped tungsten oxide particles, and rubidium-doped tungsten oxide particles. Further, heat insulating particles other than these may be used.

[0040] In addition, heat insulating agents also include heat insulating compounds. The heat insulating compounds are organic materials or organic-inorganic composite materials that can absorb infrared rays, and are also referred to as near-infrared absorbers. The near-infrared absorber has an absorption maximum in the near-infrared region, and among the absorption maxima existing in the region of a wavelength of 380 nm to 2500 nm, it shows the maximum absorption. Specifically, it has the maximum absorption in a wavelength region of 720 nm or more, preferably 750 nm or more and 2000 nm or less. Examples of the heat insulating compounds include one or more compounds selected from phthalocyanine compounds, naphthalocyanine compounds, and anthracyanine compounds. The phthalocyanine compound is phthalocyanine or a phthalocyanine derivative having a phthalocyanine skeleton, and preferably contains a metal atom therein. The naphthalocyanine compound is naphthalocyanine or a naphthalocyanine derivative having a naphthalocyanine skeleton, and preferably contains a metal atom therein. The anthracyanine compound is anthracyanine or an anthracyanine derivative having an anthracyanine skeleton, and preferably contains a metal atom therein. In these compounds, the metal atom serves as the central metal of the naphthalocyanine skeleton, naphthalocyanine skeleton, and anthracyanine skeleton. The heat insulation material may be used alone or in combination of two or more kinds.

[0041] In addition, the colorant used is not particularly limited, and dyes conventionally incorporated into the interlayer film can be used, such as dyes of blue, yellow, red, green, purple, white, etc. Pigments, dyes, etc. can be used as the dye. By using a colorant, the interlayer film can be colored in a desired color. As described above, the interlayer film can be made into a low-chroma black by containing a graphene-based material, but by further containing a colorant other than black, it can be colored into a black having a desired color according to the colorant. The colorant is not particularly limited, but for example, it may be contained in a resin layer containing a graphene-based material, that is, a colored resin layer.

[0042] Examples of the pigment include copper phthalocyanine pigments such as pigment blue, phthalocyanine-based pigments such as cobalt phthalocyanine pigments, anthraquinone-based pigments, perylene pigments, diketopyrrolopyrrole-based pigments, quinacridone-based pigments, perinone-based pigments, thioindigo-based pigments, isoindoline-based pigments, isoindolinone-based pigments, quinophthalone-based pigments, fluorene-based pigments, dioxazine-based pigments, pyricoline-based pigments, fluorubine-based pigments, azo-based pigments, titanium oxide-based pigments, calcium carbonate-based pigments, metal oxide-based pigments, Ni complex-based pigments, and other metal complex-based pigments. In addition, examples include azo dyes, cyanine dyes, triphenylmethane dyes, phthalocyanine dyes, anthraquinone dyes, naphthoquinone dyes, quinoneimine dyes, methine dyes, azomethine dyes, squarylium dyes, acridine dyes, styryl dyes, coumarin dyes, quinoline dyes, nitro dyes, etc. The dye may be a disperse dye. The pigments and dyes constituting the above-described colorant may be directly incorporated into the resin, or may be incorporated into the resin after being in the form of ink, toner, or the like.

[0043] In addition to the graphene-based material, light-shielding agent, and colorant, the interlayer film may also contain additives such as ultraviolet absorbers, antioxidants, light stabilizers, adhesion modifiers, fluorescent brighteners, and crystal nucleating agents as necessary.

[0044] <Layer structure> Hereinafter, the layer structure of the interlayer film of the present invention will be described in more detail. (Single-layer structure) In the present invention, the interlayer film may be composed of a single resin layer (also referred to as the "first resin layer"). When the interlayer film is composed of a single resin layer, the resin layer becomes a colored resin layer containing a graphene-based material. Note that both surfaces of the single resin layer may be adhered to the glass plates constituting the laminated glass. The entire region of the interlayer film with a single-layer structure may be a region containing a graphene-based material (colored region). Hereinafter, for convenience, the region colored by the graphene-based material is referred to as the "colored region" in this specification, and the region colored only by materials other than the "graphene-based material" shall not be referred to as the "colored region".

[0045] (Multi-layer structure) As described above, the interlayer film may have a multi-layer structure including a plurality of resin layers. The multi-layer structure composed of a plurality of resin layers may be a two-layer structure in which two resin layers are laminated in the thickness direction, a three-layer structure in which three resin layers are laminated, or a structure in which four or more resin layers are laminated. Among these, it is preferable to have a two-layer to five-layer structure, more preferably a three-layer to five-layer structure, and even more preferably a three-layer structure. In the case of a multi-layer structure, at least one resin layer becomes a colored resin layer containing a graphene-based material.

[0046] Hereinafter, specific examples in the case where the interlayer film has a multi-layer structure will be described using the first to seventh embodiments shown in FIGS. 1 to 7. The interlayer film 10 of the first embodiment shown in FIG. 1 is an interlayer film having a two-layer structure, and has a first resin layer 11 and a second resin layer 12, and the second resin layer 12 is provided on one surface side of the first resin layer 11. In the case of laminated glass, the intermediate film 10 with a two-layer structure may have the first resin layer 11 adhered to one glass plate and the second resin layer adhered to the other glass plate. Either the first resin layer 11 or the second resin layer 11 may be a colored resin layer, or both may be colored resin layers. Note that as shown in FIG. 1, the entire region of the intermediate film 10 with a two-layer structure may consist of a two-layer structure and the entire region may be a colored region.

[0047] The intermediate film 10 of the second embodiment shown in FIG. 2 is an intermediate film with a three-layer structure, having first to third resin layers 11, 12, and 13. The second resin layer 12 is provided on one side surface of the first resin layer 11, and the third resin layer 13 is provided on the other side surface of the first resin layer 11. In the laminated glass, the second resin layer 11 of the intermediate film 10 of the third embodiment may be adhered to one glass plate and the third resin layer 13 may be adhered to the other glass plate. At least one of the first to third resin layers 11, 12, and 13 contains a graphene-based material and becomes a colored resin layer. Specifically, among the first to third resin layers 11, 12, and 13, only the first resin layer 11 may become a colored resin layer, or only one of the second and third resin layers 12 and 13, or both of them may become colored resin layers. Further, the first resin layer 11 and one of the second and third resin layers 12 and 13 may become colored resin layers. Also, all of the first to third resin layers 11, 12, and 13 may become colored resin layers. Among the above, preferably at least the first resin layer 11 becomes a colored resin layer. When the first resin layer 11 is a colored resin layer, by containing an ultraviolet absorber in the second resin layer, ultraviolet rays can be effectively shielded, and the durability of the graphene contained in the first resin layer 11 can be enhanced.

[0048] When the intermediate film has a multilayer structure, as shown in FIGS. 1 and 2, the entire region of the intermediate film may be a colored region, or a part of the region may be a colored region. Specifically, when having three resin layers 11, 12, and 13 and a three-layer structure like the intermediate film 10 shown in the third embodiment shown in FIG. 3, in a part of the region 21 (the first region 21), the first resin layer 11 may be disposed between the second and third resin layers 12 and 13 and have a structure embedded between these resin layers 12 and 13. Here, in the first region 21, the thickness of the first resin layer 11 is a region (gradation region) where it continuously decreases along the direction orthogonal to the thickness direction (that is, one direction in the plane direction) from the thickest part 21A at the end of the intermediate film 10, and has a tapered shape along the direction orthogonal to the thickness direction. And in the region beyond the tip of the tapered shape (that is, the second region 22 adjacent to the first region 21), the second and third resin layers 12 and 13 may be directly laminated and integrated to form one resin layer 25.

[0049] Here too, as described above, at least one of the first to third resin layers 11, 12, and 13 may be a colored resin layer, but among them, it is preferable that the first resin layer 11 is a colored resin layer. When the first resin layer 11 is a colored resin layer, as going from the thickest part 21A toward the second region 22, the shading gradually changes and the visible light transmittance also gradually increases, and an intermediate film with excellent designability can be provided. Further, when the first resin layer 11 is a colored resin layer, it is preferable that each of the second and third resin layers 12 and 13 does not contain a graphene-based material, or the mass ratio of the graphene-based material in each of the resin layers 12 and 13 is lower than the mass ratio in the first resin layer 11. Thereby, the first region 21 can be a colored region, the second region 22 can be a non-colored region, or a low-colored region that is a colored region but has a lower degree of coloring by graphene than the first region 21. Here, the non-colored region means a region that does not contain a graphene-based material and is not colored by the graphene-based material, and the low-colored region is a region where the amount per unit area of the graphene-based material is relatively small. The low-colored region and the non-colored region are typically regions where the visible light transmittance is relatively high, that is, the visible light transmittance of the second region 22 is preferably higher than that of the first region.

[0050] In addition, as shown in the intermediate film 10 of the third embodiment described above, in the first region 21, when the first resin layer 11 is disposed between the second and third resin layers 12 and 13 and has a structure embedded between these resin layers 12 and 13, the configuration of the first region 21 is not limited to the above. For example, like the intermediate film 10 of the fourth embodiment shown in FIG. 4, the first region 21 may include a region 21X having a constant thickness and a region (gradation region) 21Y that is connected to the region 21X and whose thickness continuously decreases along a direction orthogonal to the thickness direction. In this case, on the tip side of the tapered shape of the region 21Y, the second and third resin layers 12 and 13 are directly laminated in the same manner as in the third embodiment, and these are integrated to form a resin layer 25. In the fourth embodiment (FIG. 4) as well, at least one of the first to third resin layers 11, 12, and 13 may be a colored resin layer, but it is particularly preferable that the first resin layer 11 is a colored resin layer. When the first resin layer 11 is a colored resin layer, the thickest part 21A becomes a region 21X having a certain area. For example, the area of a portion with high light-shielding properties can be increased, and it is easy to enhance the heat insulation properties of the intermediate film. In addition, in the fourth embodiment, the configuration for which the description is omitted is as described in the third embodiment.

[0051] Also, in the above-described third and fourth embodiments, only one first region 21 was provided, but as shown in the fifth embodiment of FIG. 5, a plurality of first regions 21 may be provided. That is, in the above description, the first region 21 was provided only at one end in the direction orthogonal to the thickness direction, but it may be provided at both ends like the intermediate film of the fifth embodiment. Also in the fifth embodiment, at least one of the first to third resin layers 11, 12, 13 may be a colored resin layer, and among them, it is preferable that the first resin layer 11 is a colored resin layer. When the first resin layer 11 is a colored resin layer, colored regions composed of the first region 21 are provided at both ends of the intermediate film 10, and both ends of the intermediate film 10 become light-shielding portions with light-shielding properties, and the heat-shielding properties of the intermediate film can be enhanced. Note that in the intermediate film of the fifth embodiment, the other configurations are the same as those of the intermediate film of the third embodiment, and thus the description thereof is omitted. Also, in the fifth embodiment, each first region 21 is composed of a gradation region, but similar to the fourth embodiment, it may be composed of a region 21X having a constant thickness and a region 21Y composed of a gradation region.

[0052] Furthermore, the first region 21 in which the first resin layer 11 is embedded between the first and second resin layers 12 and 13 may be provided at a position other than the end, for example, as shown in the sixth embodiment of FIG. 6, it may be provided between both ends (central portion). Here, the first region 21 is composed of a region 21X having a constant thickness and regions (gradation regions) 21Y, 21Y that connect to both ends of the region 21X and whose thickness continuously decreases along the direction orthogonal to the thickness direction. Also, a second region 22 is provided on the tapered end side of each region 21Y, similar to the third to fifth embodiments. In the second region 22, the second resin layers 12 and the third resin layer 13 are directly laminated, and these become integrated to form a resin layer 25. In the sixth embodiment as well, at least one of the first to third resin layers 11, 12, and 13 may be a colored resin layer, and among them, it is preferable that the first resin layer 11 is a colored resin layer. When the first resin layer 11 is a colored resin layer, the central portion of the intermediate film 10 becomes a colored region (light-shielding portion formed of the first region 21), and the heat shielding property of the intermediate film can be enhanced. Note that in the intermediate film of the sixth embodiment, since other configurations are the same as those of the intermediate film of the third embodiment, the description thereof is omitted.

[0053] Of course, the resin layer may have four or more layers. In the intermediate film, in addition to the first to third resin layers described with reference to the second to sixth embodiments (FIGS. 2 to 6), a fourth resin layer, or fourth and fifth resin layers may be provided. In this case, the intermediate film may have a laminated structure provided in the order of, for example, the third, first, second, and fourth resin layers. Similarly, when the fourth and fifth resin layers are provided, it is preferable to have a laminated structure provided in the order of, for example, the third, first, second, fourth, and fifth resin layers.

[0054] A preferred embodiment of the laminated structure in which the first to fifth resin layers are provided will be described as the seventh embodiment with reference to FIG. 7. When having the first to fifth resin layers, similar to the third to sixth embodiments described above, the first resin layer is preferably provided in a partial region of the entire region of the intermediate film. As shown in FIG. 7, in a partial region (the first region 21), the first resin layer 11 is disposed between the second and third resin layers 12 and 13 and has a structure embedded between these resin layers 12 and 13. In the other region (the second region 22), the first resin layer 11 is not provided, and the second and third resin layers 12 and 13 are directly laminated to be integrated into one resin layer 25. The fourth resin layer 14 and the fifth resin layer 15 may be provided in this order on the surface of the second resin layer 12. The intermediate film 10 having such a configuration can be formed by appropriately imparting functions to the intermediate film 10 by the fourth resin layer 14 and the fifth resin layer 15.

[0055] In the seventh embodiment (FIG. 7) as well, as described in the third embodiment, at least one of the first to third resin layers 11, 12, and 13 may contain a graphene-based material to form a colored resin layer. However, also in this embodiment, preferably at least the first resin layer 11 is a colored resin layer. When the first resin layer 11 is a colored resin layer, as going from the thickest portion 21A toward the second region 22, the shading gradually changes and the visible light transmittance can also gradually increase, enabling the provision of an intermediate film with excellent design properties. Furthermore, a colored region can be formed partially in the intermediate film 10. Of course, one or both of the fourth resin layers 14 and 15 may contain a graphene-based material. Note that, for example, when the fourth resin layer 14 and the fifth resin layer 15 are provided, the shapes and layer configurations of the first to third resin layers 11, 12, and 13 do not necessarily need to be the same as those in the third embodiment (FIG. 3), and may be the same as those in the fourth to sixth embodiments (FIGS. 4 to 6). Of course, they may also be the same as those in the second embodiment (FIG. 2).

[0056] In the third to seventh embodiments described above, in the first region 21, the resin layers adjacent in the thickness direction (for example, the third and first resin layers 13, 11, and the first and second resin layers 11, 12, and additionally the second and fourth resin layers 12, 14, and the fourth and fifth resin layers 14, 15) may have different compositions from each other. On the other hand, the second resin layer 12 and the third resin layer 13 both have the same composition, and in the second region 22, these two resin layers 12 and 13 are integrated and described on the premise of becoming one layer (the first layer 25). However, the two resin layers 12 and 13 may have different compositions from each other and may form a multilayer structure with the two resin layers 12 and 13 instead of becoming one layer in the second region 22. Similarly, in the second embodiment, the resin layers adjacent in the thickness direction in the entire region (for example, the third and first resin layers 13, 11, and the first and second resin layers 11, 12) may have different compositions from each other. On the other hand, the third resin layer 13 and the second resin layer 12 may have different compositions from each other or may be the same as each other. Note that the laminated structure described above is an example of the laminated structure of the intermediate film of the present invention and is not limited to these structures.

[0057] In each of the above laminate structures, the details of the resin and the plasticizer in each resin layer are as described above, and it is preferable that each resin layer has a configuration as described above as appropriate. For example, in the case of a multilayer structure having the first to third resin layers 11 to 13 as in the second to sixth embodiments, and the first to third resin layers 11 to 13 containing polyvinyl acetal resin as the resin constituting each resin layer, the details of the polyvinyl acetal resin constituting the first to third resin layers 11, 12, 13, and the details of the plasticizer are as described above. Similarly, for example, in the case of a multilayer structure having the first to fifth resin layers 11 to 15 as in the seventh embodiment, and the first to fifth resin layers 11 to 15 containing polyvinyl acetal resin as the resin constituting each resin layer, the details of the polyvinyl acetal resin constituting the first to fifth resin layers 11 to 15, and the details of the plasticizer are as described above.

[0058] However, for example, in the second embodiment, the content of the polyvinyl acetal resin and the plasticizer contained in each of the first to third resin layers 11, 12, 13 is preferably the following configuration. By adjusting the content of the polyvinyl acetal resin and the plasticizer according to the following description, the first resin layer 11 can easily exhibit its function as a sound insulation layer, enhance the adhesiveness of the intermediate film 10 to the glass plate, and improve the sound insulation performance. In the following description, the polyvinyl acetal resins contained in each of the first to third resin layers 11, 12, 13 will be described as polyvinyl acetal resins (1), (2), and (3). Also, the content of the plasticizer with respect to 100 parts by mass of the resin in each resin layer (for example, each of the first to third resin layers 11, 12, 13) will be described as content (1), (2), and (3).

[0059] That is, from the viewpoint of enhancing the sound insulation property of the first resin layer 11 while maintaining the adhesiveness of the second and third resin layers 12 and 13 to the glass plate, the hydroxyl group content of the polyvinyl acetal resin (1) is preferably lower than the hydroxyl group content of the polyvinyl acetal resin (2). Similarly, the hydroxyl group content of the polyvinyl acetal resin (1) is preferably lower than the hydroxyl group content of the polyvinyl acetal resin (3). The absolute value of the difference between the hydroxyl group content of the polyvinyl acetal resin (1) and the hydroxyl group contents of the polyvinyl acetal resins (2) and (3) is preferably 1 mol% or more, respectively. Thereby, the sound insulation property can be further enhanced. From such a viewpoint, the difference in each hydroxyl group content is more preferably 5 mol% or more. The absolute value of the difference in each hydroxyl group content is preferably 20 mol% or less.

[0060] The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (1) is preferably 15 mol% or more, more preferably 17 mol% or more, and for example, 35 mol% or less, preferably 33 mol% or less. When the hydroxyl group content is at least the above lower limit, the bending rigidity of the interlayer film becomes high, and the productivity and the like are excellent. Further, from the viewpoint of the polyvinyl acetal resin (1) absorbing a plasticizer to enhance the sound insulation property of the laminated glass, it is more preferably 30 mol% or less, still more preferably 25 mol% or less.

[0061] The respective hydroxyl group contents of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) are, for example, 20 mol% or more, preferably 25 mol% or more. When the hydroxyl group content is at least the above lower limit, the bending rigidity can be made higher while maintaining the sound insulation property, and the adhesiveness can also be enhanced. Further, from the viewpoint of further enhancing the adhesiveness to the glass plate, it is more preferably 28 mol% or more. The respective hydroxyl group contents of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) are preferably 38 mol% or less, more preferably 35 mol% or less, and still more preferably 33 mol% or less. When the hydroxyl group content is at or below the above upper limit, the polyvinyl acetal resin is likely to precipitate during the synthesis of the polyvinyl acetal resin.

[0062] The degree of acetalization of the polyvinyl acetal resin (1) is preferably 47 mol% or more, more preferably 55 mol% or more, still more preferably 60 mol% or more, and preferably 85 mol% or less, more preferably 80 mol% or less, still more preferably 75 mol% or less. When the degree of acetalization is at least the above lower limit, the compatibility between the polyvinyl acetal resin (1) and the plasticizer becomes high. When the degree of acetalization is at most the above upper limit, the amount of residual aldehyde in the resin can be reduced.

[0063] The degree of acetalization of each of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) (the degree of butyralization in the case of the polyvinyl butyral resin) is preferably 47 mol% or more, more preferably 55 mol% or more, still more preferably 60 mol% or more, and preferably 85 mol% or less, more preferably 80 mol% or less, still more preferably 75 mol% or less. When the degree of acetalization is at least the above lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer becomes high. When the degree of acetalization is at most the above upper limit, the amount of residual aldehyde in the resin can be reduced.

[0064] The degree of acetylation (acetyl group amount) of the polyvinyl acetal resin (1) is preferably 0.01 mol% or more, more preferably 0.1 mol% or more. Also, from the viewpoint of enhancing the compatibility between the polyvinyl acetal resin and the plasticizer and facilitating the incorporation of a large amount of the plasticizer, the degree of acetylation is more preferably 7 mol% or more, particularly preferably 9 mol% or more. Also, the degree of acetylation of the polyvinyl acetal resin (1) is preferably 30 mol% or less, more preferably 25 mol% or less, still more preferably 20 mol% or less. When the degree of acetylation is at most the above upper limit, the moisture resistance of the intermediate film and the laminated glass becomes high.

[0065] The degree of acetylation of each of polyvinyl acetal resin (2) and polyvinyl acetal resin (3) is preferably 10 mol% or less, more preferably 2 mol% or less. When the degree of acetylation is at or below the above upper limit, the moisture resistance of the interlayer film and the laminated glass increases. Although not particularly limited, it is preferably 0.01 mol% or more, more preferably 0.1 mol% or more.

[0066] Also, when the PVA for obtaining polyvinyl acetal resins (1), (2), and (3) is described as PVA(1), (2), and (3), the average degree of polymerization of PVA(1), (2), and (3) is as described for the above PVA. However, when increasing the content of the plasticizer, it is preferable to increase the average degree of polymerization of PVA. Therefore, in the first resin layer 11, for example, when the content (1) of the plasticizer is 55 parts by mass or more, it is also preferable to set the average degree of polymerization of PVA(1) to 2000 or more. From the same viewpoint, it is preferable that the average degree of polymerization of PVA(1) is equal to or higher than the average degrees of polymerization of PVA(2) and (3). Thus, when the average degree of polymerization of PVA(1) is increased, in the first resin layer, for example, even when the content of the plasticizer is increased, various performances are likely to be maintained.

[0067] The content (1) of the plasticizer is, for example, 20 parts by mass or more, preferably 30 parts by mass or more, more preferably 35 parts by mass or more. When the content (1) is at or above the above lower limit, the flexibility of the interlayer film increases and the handling of the interlayer film becomes easier. Also, from the viewpoint of sound insulation, it is preferable to make the content (1) higher. From such a viewpoint, the content (1) is more preferably 55 parts by mass or more, and even more preferably 60 parts by mass or more. Also, the content (1) is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, still more preferably 85 parts by mass or less, and particularly preferably 80 parts by mass or less. When the content (1) is at or below the above upper limit, the penetration resistance of the laminated glass becomes even higher.

[0068] The content of the plasticizer (2) and the content of the plasticizer (3) are each preferably 10 parts by mass or more. When the content (2) and the content (3) are not less than the above lower limits, the flexibility of the intermediate film becomes high and the handling of the intermediate film becomes easy. Further, from these viewpoints, the content (2) and the content (3) are each more preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, and particularly preferably 24 parts by mass or more. Also, each of the content (2) and the content (3) is preferably 70 parts by mass or less, more preferably 63 parts by mass or less, still more preferably 54 parts by mass or less, and even more preferably 50 parts by mass or less. When each of the content (2) and the above content (3) is not more than the above upper limit, the mechanical properties such as the bending rigidity of the intermediate film become good.

[0069] In order to enhance the sound insulation property of the laminated glass, the content of the plasticizer (1) is preferably more than the content (2), preferably more than the above content (3), and more preferably more than both of the above content (2) and (3). Also, from the viewpoint of further enhancing the sound insulation property of the laminated glass, the absolute value of the difference between the content (1) and the content (2), and the absolute value of the difference between the content (1) and the content (3) are each preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and still more preferably 25 parts by mass or more. The absolute value of the difference between the above content (1) and the above content (2), and the absolute value of the difference between the above content (1) and the above content (3) are each preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and still more preferably 60 parts by mass or less.

[0070] Also, the content of the polyvinyl acetal resin and the plasticizer contained in each of the first to fifth resin layers 11 to 15 is preferably configured as follows. By adjusting the content of the polyvinyl acetal resin and the plasticizer according to the following description, the fourth resin layer 14 can easily exhibit its function as a sound insulation layer, and while enhancing the adhesiveness of the intermediate film 10 to the glass plate, the sound insulation property can be enhanced.

[0071] That is, let the polyvinyl acetal resin contained in the fourth resin layer 14 be polyvinyl acetal resin (A), and the polyvinyl acetal resin contained in the fifth resin layer 15 be polyvinyl acetal resin (B). Further, let the polyvinyl acetal resin contained in each of the second and third resin layers 12 and 13 be polyvinyl acetal resin (C). In such a case, polyvinyl acetal resin (A) may be the polyvinyl acetal resin (1) described above, polyvinyl acetal resin (B) may be the polyvinyl acetal resin (2) described above, and polyvinyl acetal resin (C) may be the polyvinyl acetal resin (3) described above. Also, let the content of the plasticizer with respect to 100 parts by mass of the thermoplastic resin in the fourth resin layer 14 be content (A), and the content of the plasticizer with respect to 100 parts by mass of the thermoplastic resin in the fifth resin layer 15 be content (B). Further, if the content of the plasticizer with respect to 100 parts by mass of the thermoplastic resin in each of the second and third resin layers 12 and 13 is content (C), then content (A), (B), and (C) may each be the content (1), (2), and (3) described above.

[0072] In the five-layer structure as in the seventh embodiment, by adjusting the content of the resin and the plasticizer in the second and third resin layers 12 and 13, the fourth resin layer 14, and the fifth resin layer 15 as described above, the fourth resin layer 14 is more likely to have the function as a sound insulation layer, and while enhancing the adhesion of the intermediate film 10 to the glass plate, the sound insulation can also be enhanced. Also, as described above, if the first resin layer 11 is a colored resin layer, an intermediate film excellent in design can be provided, and furthermore, a colored region can be partially formed in the intermediate film 10. Note that the content of the polyvinyl acetal resin and the plasticizer in the first resin layer 11 is not particularly limited, and it is not necessary to use polyvinyl acetal resins (1), (2), (3) or contents (1), (2), (3), but it is advisable to appropriately design according to the preferred ranges of the content of the polyvinyl acetal resin and the plasticizer described above.

[0073] [Thickness of each layer] The thickness of the intermediate film is preferably 0.2 mm or more and 2.0 mm or less. By adjusting the content ratio of the graphene-based material as described above and setting the thickness within these ranges, it becomes easier to adjust the heat insulation property, visible light transmittance, chroma, etc. within desired ranges. The thickness of the intermediate film is more preferably 0.25 mm or more and 1.0 mm or less, and even more preferably 0.3 mm or more and 0.9 mm or less.

[0074] In the multilayer structure, the thickness of the colored resin layer is not particularly limited, but the thickness ratio (colored resin layer / total thickness) is, for example, 0.01 or more and 1 or less, preferably 0.03 or more and 0.75 or less, and more preferably 0.05 or more and 0.45 or less with respect to the total thickness of the intermediate film. Also, the specific thickness of the colored resin layer in the multilayer structure is not particularly limited, but is, for example, 0.02 mm or more and 1 mm or less, preferably 0.03 mm or more and 0.8 mm or less, and even more preferably 0.04 mm or more and 0.5 mm or less. By setting the thickness of the colored resin layer to 0.02 mm or more and 1 mm or less, it becomes easier to impart the heat insulation property and design property of the intermediate film without making the intermediate film larger than necessary. Note that the thickness of the colored resin layer means the total thickness when there are two or more colored resin layers. Also, the thickness of the colored resin layer is the thickness of the colored resin layer at the hottest part (thickest part) of the colored resin layer.

[0075] As described above, when the first to third resin layers are contained in the multilayer structure, it is preferable that the first resin layer is a colored resin layer. In such a case, the thickness of the first resin layer (colored resin layer) is not particularly limited, but is 0.02 mm or more and 1 mm or less, preferably 0.03 mm or more and 0.8 mm or less, and even more preferably 0.04 mm or more and 0.5 mm or less. Also, the thickness of each of the second and third resin layers is not particularly limited, but is, for example, 0.1 mm or more and 0.7 mm or less, more preferably 0.15 mm or more and 0.6 mm or less, and even more preferably 0.2 mm or more and 0.5 mm or less. In addition, when the fourth and fifth resin layers are provided, the thicknesses of the fourth and fifth resin layers are not particularly limited, but for example, they are 0.1 mm or more and 0.7 mm or less, more preferably 0.15 mm or more and 0.6 mm or less, and still more preferably 0.2 mm or more and 0.5 mm or less. As described above, the thickness of the first resin layer may vary, and the thicknesses of each layer may also vary. However, the thicknesses of the first to fifth resin layers are the thicknesses of each resin layer at the portion where the thickness of the first resin layer is the largest (thickest portion).

[0076] [Optical properties of the interlayer film] On one side, the visible light transmittance (Tv) of the interlayer film of the present invention is preferably 70% or more. The visible light transmittance (Tv) of the interlayer film and the total solar energy transmittance (Tts) described later are values measured in a laminated glass produced by bonding two reference glass plates (1) through the interlayer film disposed therebetween. The reference glass plate (1) is a clear glass plate with a thickness of 2.5 mm each, having a visible light transmittance of 90.5%, a solar energy transmittance of 87.3%, and a solar energy reflectance of 8.3% measured in accordance with JIS R 3106:1998. However, regarding the visible light transmittance (Tv) of the interlayer film in the following formulas (2), (2-1), and (2-2), it is a value measured in a laminated glass produced by bonding two reference glass plates (2) described later through the interlayer film disposed therebetween.

[0077] In addition, the chroma (C) of the interlayer film described later is a value measured in a laminated glass produced by bonding two reference glass plates (2) through the interlayer film disposed therebetween. The reference glass plate (2) is a clear glass plate with a thickness of 2.5 mm each, having a visible light transmittance of 90.5% measured in accordance with JIS R 3106:1998 and a chroma of 0.6 measured in accordance with JIS Z 8781.

[0078] In addition, the intermediate film may have a colored region containing a graphene-based material and a non-colored region not containing a graphene-based material. In that case, unless otherwise specified, the visible light transmittance (Tv), the global solar transmittance (Tts) described later, and the chroma (C) refer to the visible light transmittance (Tv), the global solar transmittance (Tts), and the chroma (C) in the colored region. Further, the colored region has a gradation region, and the content rate of the graphene-based material in the total thickness of the intermediate film may change, and the visible light transmittance and the like may also change. In that case, it is preferable to measure the visible light transmittance, the global solar transmittance (Tts), and the chroma (C) at the position where the visible light transmittance is the lowest.

[0079] When the visible light transmittance (Tv) of the above-described intermediate film is 70% or more, the transparency of the obtained laminated glass is increased, and it is preferably used for applications where an observation object is visually recognized through the laminated glass. For example, it can be suitably used for windshield glass (front glass). From the viewpoint of enhancing transparency and visibility, the visible light transmittance (Tv) of the intermediate film is more preferably 75% or more, and even more preferably 80% or more. The visible light transmittance is not particularly limited, but is, for example, 90% or less from the viewpoint of ensuring a certain heat shielding property.

[0080] Further, in another aspect, the visible light transmittance (Tv) of the intermediate film of the present invention may be less than 70%. When the visible light transmittance (Tv) is less than 70%, the laminated glass can use the colored region as a light shielding portion. From the viewpoint of suitably using the colored region as a light shielding portion, the visible light transmittance (Tv) of the intermediate film is preferably 30% or less, more preferably 10% or less, even more preferably 5% or less, and still more preferably 2% or less. Carbon black, which is widely used as a black coloring agent, is recognized as a black with a strong red tint when the transmittance is lowered, but a black close to achromatic color can be maintained by using a graphene-based material. Further, when the visible light transmittance is lowered as described above, the infrared transmittance can also be further lowered, and the heat shielding performance can be enhanced. In another aspect, the lower the visible light transmittance of the intermediate film, the better, and the lower limit is 0%.

[0081] In addition, when the interlayer film of the present invention has a non-colored region, the visible light transmittance (Tv) of the non-colored region is preferably higher than the visible light transmittance (Tv) in the colored region described above, preferably 75% or more, more preferably 80% or more, still more preferably 85% or more, and although not particularly limited, for example, it is 95% or less.

[0082] Further, the total solar energy transmittance (Tts) and the visible light transmittance (Tv) of the interlayer film preferably satisfy the requirements of the following formula (1). (Tts - 31) / Tv < 0.6 (1) By satisfying the requirements shown in the above formula (1), compared with the case where the same visible light transmittance is obtained using carbon black, which is a commonly used colorant, the interlayer film of the present invention means that the total solar energy transmittance (Tts) is significantly lower, and it means that it has excellent heat insulation properties. From the above viewpoints, it is more preferable that the total solar energy transmittance (Tts) and the visible light transmittance (Tv) of the interlayer film of the present invention satisfy the requirements of the following formula (1-1). (Tts - 29.5) / Tv < 0.6 (1-1) More preferably, it satisfies the requirements of the following formula (1-2), and most preferably, it satisfies the requirements of the following formula (1-3). (Tts - 27.5) / Tv < 0.6 (1-2) (Tts - 26.0) / Tv < 0.6 (1-3)

[0083] Furthermore, the chroma (C) and the visible light transmittance (Tv) of the interlayer film preferably satisfy the requirements of the following formula (2). (C - 16) / Tv < -0.15 (2) By satisfying the requirements shown in the above formula (2), compared with the case where the same visible light transmittance is obtained using carbon black, which is a commonly used colorant, the interlayer film of the present invention means that the chroma (C) is significantly lower, and it means that it has excellent design properties. From the above viewpoints, it is more preferable that the total solar energy transmittance (Tts) and the visible light transmittance (Tv) of the interlayer film of the present invention satisfy the requirements of the following formula (2-1). (C - 9) / Tv < -0.06 (2 - 1) More preferably, the following formula (2 - 2) is satisfied. (C - 4) / Tv < -0.001 (2 - 2)

[0084] Also, the chroma (C) of the intermediate film is not particularly limited, but preferably 15 or less, more preferably 10 or less, still more preferably 8 or less, even more preferably 6 or less, and most preferably 3 or less. When the chroma (C) is made small, it becomes easier to make the intermediate film achromatic black. The lower the chroma (C) of the intermediate film, the more achromatic it becomes, and it may be 0 or more.

[0085] (Manufacturing method of the intermediate film) The intermediate film of the present invention is not particularly limited. When it has a single - layer structure, for example, components constituting the intermediate film such as resin, graphene - based materials, and additives blended as necessary are mixed, and the obtained resin composition may be formed by extrusion molding, press molding, etc. Note that, from the viewpoint of enhancing the dispersibility in the resin composition, for example, when using a plasticizer, the graphene - based material may be blended with the plasticizer and sufficiently dispersed in the plasticizer, and then mixed with the resin. At this time, a dispersant or the like may be appropriately added to the plasticizer. As the dispersant, a surfactant or a polymer compound is used. As the polymer compound, amphiphilic polymer compounds such as polyvinyl alcohol and polyvinyl butyral resin are suitable. Particularly, polyvinyl butyral is preferable. Polymer compounds such as polyvinyl butyral used as the dispersant may be used as part of the resin constituting the intermediate film as it is. Also, as the dispersant, a cationic compound such as an aliphatic amine and its salt may be used.

[0086] Even when the intermediate film has a multilayer structure, it may be formed by extrusion molding, press molding, etc., in the same manner as in the case of a single - layer structure. For example, a method of preparing two or more extruders and attaching a feed block for multilayer to the tip of the plurality of extruders and co - extruding is preferable. For example, it is preferable to prepare a plurality of extruders, supply the components constituting each resin layer to each extruder, and attach a feed block for multilayer to the tip of each of these extruders for coextrusion. Further, when a plurality of resin layers are provided and there are two or more resin layers having the same composition (for example, the second and third resin layers), two or more resin layers having the same composition may be extruded from one extruder. Furthermore, each resin layer may have a thickness that changes along a direction orthogonal to the thickness direction. In that case, for example, the thickness may be changed by adjusting the supply amount of the resin or the like.

[0087] <Laminated glass> The present invention further provides laminated glass. The laminated glass includes two glass plates and an intermediate film disposed between these glass plates, and the two glass plates are adhered via the intermediate film. One surface of the intermediate film adheres to one glass plate, and the other surface adheres to the other glass plate. The laminated glass may be manufactured by disposing the above-described intermediate film between two glass plates and integrating them by pressure bonding or the like.

[0088] (Glass plate) As the glass plate used for the laminated glass, either inorganic glass or organic glass may be used, but inorganic glass is preferable. The inorganic glass is not particularly limited, and examples thereof include clear glass, float plate glass, polished plate glass, patterned plate glass, wired glass, lined glass, and green glass. As the organic glass, what is generally called resin glass is used and is not particularly limited, and examples thereof include organic glass composed of resins such as polycarbonate, acrylic resin, acrylic copolymer resin, and polyester. The two glass plates may be composed of the same kind of material as each other, or may be composed of different materials. For example, one may be inorganic glass and the other may be organic glass, but it is preferable that both of the two glass plates are inorganic glass or organic glass. Also, the thickness of each glass plate is not particularly limited. For example, it is about 0.1 to 15 mm, preferably 0.5 to 5 mm. The thicknesses of the respective glass plates may be the same as or different from each other, but it is preferable that they are the same.

[0089] [Optical properties of laminated glass] The laminated glass of the present invention preferably has optical properties similar to those of the intermediate film described above. Specifically, the laminated glass of the present invention preferably has a visible light transmittance of 70% or more, preferably 75% or more, and more preferably 80% or more on one side, in the same manner as the above intermediate film. Also, the visible light transmittance is not particularly limited, but is, for example, 90% or less. Also, the laminated glass of the present invention may have a visible light transmittance of less than 70% on another side, in the same manner as the above intermediate film. On another side, the visible light transmittance of the laminated glass is preferably 30% or less, more preferably 10% or less, still more preferably 5% or less, and even more preferably 2% or less. On another side, the lower the visible light transmittance of the laminated glass, the better, and the lower limit is 0%.

[0090] Note that the visible light transmittance (Tv) of the laminated glass, the total solar energy transmittance (Tts) of the laminated glass described later, and the chroma (C) of the laminated glass mean the visible light transmittance (Tv), the total solar energy transmittance (Tts), and the chroma (C) in the colored region, unless otherwise specified. Also, the colored region is preferably the region where the visible light transmittance is the lowest, and the visible light transmittance, the total solar energy transmittance (Tts), and the chroma (C) are measured.

[0091] When the intermediate film of the laminated glass of the present invention has a non-colored region, the visible light transmittance (Tv) in the non-colored region is preferably higher than the visible light transmittance (Tv) in the colored region described above, preferably 75% or more, more preferably 80% or more, still more preferably 85% or more, and is not particularly limited, but is, for example, 95% or less.

[0092] Also, similar to the intermediate film, the total solar energy transmittance (Tts) and visible light transmittance (Tv) of the laminated glass preferably satisfy the requirements of the following formula (1), more preferably satisfy the requirements of the following formula (1-1), even more preferably satisfy the requirements of the following formula (1-2), and even more preferably satisfy the requirements of the following (1-3). (Tts - 31) / Tv < 0.6 (1) (Tts - 29.5) / Tv < 0.6 (1-1) (Tts - 27.5) / Tv < 0.6 (1-2) (Tts - 26.0) / Tv < 0.6 (1-3) Furthermore, similar to the intermediate film, the colorfulness (C) and visible light transmittance (Tv) of the laminated glass preferably satisfy the requirements of the following formula (2), more preferably satisfy the requirements of the following formula (2-1), and even more preferably satisfy the requirements of the following formula (2-2). (C - 16) / Tv < -0.15 (2) (C - 9) / Tv < -0.06 (2-1) (C - 4) / Tv < -0.001 (2-1) Note that the visible light transmittance (Tv), total solar energy transmittance (Tts), and colorfulness (C) of the laminated glass can be measured for the obtained laminated glass according to the method described in the examples below.

[0093] Also, from the same viewpoint as the colorfulness (C) of the intermediate film, the colorfulness (C) of the laminated glass is not particularly limited, but is preferably 15 or less, more preferably 10 or less, even more preferably 8 or less, and even more preferably 6 or less. Also, the colorfulness (C) of the laminated glass may be 0 or more.

[0094] The laminated glass of the present invention can be used as window glass for various vehicles such as automobiles, airplanes, ships, buildings, etc., but is preferably used as laminated glass for automobiles. The laminated glass for automobiles may be any of windshield glass (front glass), side glass, rear glass, and roof glass. When used as automotive laminated glass, the entire surface of the laminated glass may be a colored region, or a part of it may be a colored region. For example, in any of the front glass, side glass, rear glass, and roof glass, according to the configurations of the third and fourth embodiments (Figs. 3 and 4), etc., a colored region may be provided at the upper part to form a sunshade, and an uncolored region may be provided at the lower part. Also, according to the configurations of the fifth embodiment (Fig. 5), etc., in any of the side glass, rear glass, and roof glass, colored regions may be provided at the upper and lower parts to form a sunshade, and an uncolored region may be provided at the central part. Furthermore, for example, in the roof glass and side glass, the entire surface may be a colored region according to a single-layer structure or the configurations of the first and second embodiments (Figs. 1 and 2). Note that the laminated glass for an automotive roof only needs to have at least a part thereof disposed on the roof. For example, the glass disposed across the roof and the rear is also regarded as the laminated glass for an automotive roof.

Examples

[0095] The present invention will be described in more detail with reference to examples, but the present invention is not limited by these examples.

[0096] The measurement method and evaluation method in this example are as follows. (Thickness of each layer) The intermediate film was cut with a single-edge razor (「FAS-10」manufactured by Feather Safety Razor Co., Ltd.) perpendicular to the thickness direction to expose the cross-section, and the cross-section was observed with a microscope (「DSX-100」manufactured by Olympus Corporation) to measure the thickness. Note that when the first resin layer has a gradation region and the thickness changes along the direction orthogonal to the thickness direction, the thickness of each layer at the thickest part of the first resin layer is measured.

[0097] (Measurement of visible light transmittance (Tv)) In accordance with JIS R3212(2015), the visible light transmittance (Tv) was measured using a spectrophotometer ("U-4100" manufactured by Hitachi High-Technologies Corporation). During the measurement, an alignment glass was placed at a position 13 cm away from the integrating sphere on the optical path between the light source and the integrating sphere and parallel to the normal of the optical axis so that only the parallel light transmitted through the alignment glass was received by the integrating sphere, and the spectral transmittance was measured. The visible light transmittance was calculated from the obtained spectral transmittance. The measurement conditions were a scan speed of 300 nm / min and a slit width of 8 nm, and the other conditions were measured in accordance with JIS R 3212(2015).

[0098] [L*, a*, b*, Chroma (C)] The spectral spectrum was measured using a spectrophotometer ("U-4100" manufactured by Hitachi High-Technologies Corporation). During the measurement, an alignment glass was placed at a position 13 cm away from the integrating sphere on the optical path between the light source and the integrating sphere and parallel to the normal of the optical axis so that only the parallel light transmitted through the alignment glass was received by the integrating sphere, and the spectral transmittance was measured. The visible light transmittance was calculated from the obtained spectral transmittance. The measurement conditions were a scan speed of 300 nm / min and a slit width of 8 nm, and for the other measurement conditions, L*, a*, and b* were measured using the CIE standard illuminant D65 and the 10° field-of-view color matching function as defined in JIS Z 8781-1(2012), JIS Z 8781-2(2012), and JIS Z 8781-4(2013). The chroma (C) was obtained from the measured a* and b* using the following formula. C = ((a*) 2 +(b*) 2 ) 0.5

[0099] [Total solar transmittance (Tts)] The total solar transmittance (Tts:Total Solar Transmittance) is Measured in accordance with ISO13837 using a spectrophotometer ("U-4100" manufactured by Hitachi High-Technologies Corporation). The measurement conditions were a scan speed of 300 nm / min and a slit width of 8 nm. In addition, when measuring the visible light transmittance (Tv), L*, a*, b*, and global solar transmittance (Tts), if there are colored areas and non-colored areas, the measurements were performed in each of the colored areas and non-colored areas. Further, in the colored area, if there is a gradation area, the visible light transmittance (Tv), L*, a*, b*, and global solar transmittance (Tts) were measured at the position where the visible light transmittance is the lowest.

[0100] [Particle Size and Thickness of Graphene-Based Material] Ultra-thin slices were cut out from the film by the microtome method, and observed using a transmission electron microscope (JEM-2100, manufactured by JEOL Ltd.) under the condition of an acceleration voltage of 200 kV. From the observation photos, the major axis and minor axis of the graphene-based material were measured. In addition, the thickness of the graphene-based material was determined by measuring the stacked structure of the carbon hexagonal network plane in the graphene-based material from the transmission electron microscope photos. Thirty measurements were taken for each, and the arithmetic mean was calculated. The arithmetic mean value of the major axis was taken as the average particle size.

[0101] (Cloudiness) The obtained laminated glass was visually observed, and the degree of cloudiness was evaluated according to the following evaluation criteria. A: When a 270-lumen LED light source in a dark room illuminates the glass 30 cm away from the light source, five or more out of ten people judge that there is no cloudiness due to the light source on the laminated glass. B: When illuminating the glass with an LED light source in a dark room, five or fewer out of ten people judge that there is no cloudiness due to the light source on the laminated glass. C: When illuminating the glass with an LED light source under a fluorescent lamp, five or more out of ten people judge that the glass is cloudy. D: When looking at a fluorescent lamp through the laminated glass, five or more out of ten people judge that the laminated glass is cloudy.

[0102] In addition, the respective components used in the examples and comparative examples are as follows. (1) Resin Resin 1: Polyvinyl butyral resin, degree of acetalization 69 mol%, amount of hydroxyl groups 30 mol%, degree of acetylation 1 mol%, degree of polymerization 1700 (2) Plasticizer 3GO: Triethylene glycol di-2-ethylhexanoate (3) Graphene-based material Graphene-based material A: It can be produced in the same manner as the method for producing a exfoliated graphite-resin composite material described in International Publication No. 2014 / 034156. Specifically, the partially exfoliated exfoliated graphite can be obtained by preparing a composition of graphite and a resin and thermally decomposing the resin contained in the composition. Graphene-based material B: N002-PDE manufactured by Angstron Materials Graphene-based material C: N002-PD manufactured by Angstron Materials Graphene-based material D: Gi-PW-F031 manufactured by Angston Materials Graphene-based material E: Graphene-based material D was pulverized for 90 minutes using an extreme mill (MX-1200X TM, manufactured by WARING) to obtain graphene-based material E. Graphene-based material F: Graphene-based material D was dispersed in ethanol and irradiated with ultrasonic waves for 120 minutes under the condition of a frequency of 20 kHz using a desktop digital ultrasonic homogenizer (SFX250, manufactured by BRANSON) to obtain graphene-based material F. (4) Carbon black Carbon black pigment, Pigment Black 7 (5) Other colorants Red pigment: Perylene compound Pigment Red 149 (CAS No 4948-15-6) Yellow dye: Anthraquinone compound Solvent Yellow 163 (CAS No 13676-91-0)

[0103] [Example 1] (Preparation of intermediate film) First, a graphene-based material was added to 40 parts by mass of a plasticizer so that the content in the intermediate film was as shown in Table 1, and ultrasonic waves at 40 Hz were irradiated for 30 minutes using an ultrasonic disperser ("PR-1" manufactured by THINKY Corporation) to mix them sufficiently, thereby mixing the graphene-based material in the plasticizer to obtain a mixed solution. Next, the entire amount of the obtained mixed solution was added to 100 parts by mass of polyvinyl butyral resin (PVB), and melt-kneaded at 150°C for 10 minutes using a pressure kneader to obtain a resin composition. The obtained resin composition was extruded using an extruder to obtain an intermediate film with a thickness of 760 μm. The intermediate film was an intermediate film composed of a single resin layer. The intermediate film composed of a single resin layer is shown as "Configuration 1" in Table 1.

[0104] (Manufacture of laminated glass) Two clear glasses, each with a size of 30 mm in length × 30 mm in width × 2.5 mm in thickness, having a visible light transmittance of 90.5%, a solar radiation transmittance of 87.3%, a solar radiation reflectance of 8.3%, and a chromaticity of 0.6 measured in accordance with JIS R 3106:1998, were prepared. After holding the intermediate film obtained above under constant temperature and humidity conditions of 23°C and 28% RH for 4 hours, it was sandwiched between the two clear glasses to form a laminate. The obtained laminate was placed in a rubber bag, depressurized using a vacuum pump, and then heated in an oven until the glass temperature reached 90°C for temporary pressure bonding. The temporarily pressure-bonded laminate was pressure-bonded using an autoclave under the conditions of 135°C and a pressure of 1.2 MPa for 20 minutes to manufacture laminated glass. The optical properties of the obtained laminated glass were measured and shown in Table 1 as the properties of the intermediate film and the laminated glass.

[0105] [Examples 2 to 14] The same procedure as in Example 1 was carried out except that the type and addition amount of the graphene-based material were changed as shown in Table 1.

[0106] [Examples 15 and 17] First, a graphene-based material was added to 40 parts by mass of a plasticizer so that the addition amounts in each resin layer were as shown in Table 1, and thoroughly mixed to obtain a mixed solution in which the graphene-based material was mixed in the plasticizer. Next, the entire amount of the obtained mixed solution was added to 100 parts by mass of polyvinyl butyral resin (PVB), and melt-kneaded at 150°C for 10 minutes using a pressure kneader to obtain a resin composition. The first resin composition was obtained by melt-kneading at 200°C using a first extruder. Also, 40 parts by mass of a plasticizer and 100 parts by mass of polyvinyl butyral resin (PVB) were put into a second extruder to obtain a second resin composition. A multilayer feed block was attached to the tips of the first extruder and the second extruder, and a second resin layer made of the second resin composition, a first resin layer made of the first resin composition, and a third resin layer made of the second resin composition were extruded and laminated to have the thickness shown in Table 1 to obtain an intermediate film. The first to third resin layers had the same thickness in all regions of the intermediate film, and the obtained intermediate film had the configuration shown in FIG. 2. The intermediate film having the configuration shown in FIG. 2 is denoted as "Configuration 2" in Table 1.

[0107] [Example 16] The first and second resin compositions were prepared in the same manner as in Example 16, except that the addition amount of the graphene-based material was adjusted to be as shown in Table 1. A multilayer feed block was attached to the tips of the first extruder and the second extruder, and co-extrusion was performed while adjusting the amount of the extruded resin composition. As a result, as shown in FIG. 3, an intermediate film was obtained that had a first resin layer 11 embedded between the second and third resin layers 12 and 13 in the first region 21 and a resin layer 25 in which the second and third resin layers 12 and 13 were integrated in the second region 22. Thus, the intermediate film having the configuration shown in FIG. 3 is denoted as "Configuration 3" in Table 1.

[0108] [Examples 18 and 19] In addition to the graphene-based material during the preparation of the mixed solution, a colorant other than the graphene-based material was further added, and the type and addition amount of the graphene-based material and the type and addition amount of the organic pigment were adjusted to be as shown in Table 1, and the procedure was carried out in the same manner as in Example 1.

[0109] [Comparative Examples 1 - 5] The procedure of Example 1 was repeated, except that carbon black (Pigment Black 7) was used instead of the graphene - based material, and the amount of carbon black added was adjusted so that the content in the intermediate film was as shown in Table 1.

[0110] [Comparative Example 6] The procedure of Example 16 was repeated, except that carbon black was used instead of the graphene - based material, the amount of carbon black added was adjusted so that the content in the intermediate film was as shown in Table 1, and the thickness of each resin layer was adjusted to be as shown in Table 1.

[0111] [Table 1]

[0112] ※In Table 1, the content of the colorant in the colored region is the ratio to the total thickness of the intermediate film. Note that the colorant is a graphene - based material in Examples 1 - 17, the sum of the graphene - based material and other colorants in Examples 18 and 19, and carbon black in the comparative examples. ※CG in Table 1 means clear glass. The particle size means the average particle size.

[0113] As shown in FIG. 8, it can be understood that the intermediate films and laminated glasses of Examples 1 - 19 containing the graphene - based material have a lower total solar transmittance (Tts) and improved heat insulation properties compared to the comparative examples having the same visible light transmittance using carbon black instead of the graphene - based material. Note that, as is clear from FIG. 8, all of Examples 1 - 19 satisfied the requirements shown in the above - mentioned formula (1). Also, as shown in FIG. 9, it can be understood that the intermediate films and laminated glasses of Examples 1 - 19 have a lower chroma (C) and improved design properties compared to the comparative examples having the same visible light transmittance. Note that, as is clear from FIG. 9, all of Examples 1 - 19 satisfied the requirements shown in the above - mentioned formula (2).

Explanation of Symbols

[0114] 10 Intermediate film 11 First layer 12 Second layer 13 Third layer 14 Fourth layer 15 Fifth layer 21 First region 22 Second region 21A Thickest part 21X Region with constant thickness 21Y Gradation region

Claims

1. An interlayer film for laminated glass, comprising at least one graphene-based material selected from the group consisting of graphene and graphite, wherein the degree of oxidation of the graphene-based material is 50% or less.

2. The interlayer film for laminated glass according to Claim 1, wherein the content of the graphene-based material is 0.0005% by mass or more and 1% by mass or less.

3. The interlayer film for laminated glass according to Claim 1 or 2, comprising a resin and a colored resin layer containing the graphene-based material.

4. In a laminated glass produced by bonding two clear glass plates, each having a thickness of 2.5 mm, through the interlayer film for laminated glass, the total solar transmittance (Tts) and the visible light transmittance (Tv) measured in accordance with JIS R 3106:1998 are 90.5% for the visible light transmittance, 87.3% for the solar transmittance, and 8.3% for the solar reflectance, and satisfy the following formula (1). The interlayer film for laminated glass according to any one of Claims 1 to 3. (Tts - 31) / Tv < 0.6 (1)

5. In a laminated glass produced by bonding two clear glass plates, each having a thickness of 2.5 mm, through the interlayer film for laminated glass, the chroma (C) and the visible light transmittance (Tv) measured in accordance with JIS R 3106:1998 are 90.5% for the visible light transmittance and 0.6 for the chroma measured in accordance with JIS Z8781, and satisfy the following formula (2). The interlayer film for laminated glass according to any one of Claims 1 to 4. (C - 16) / Tv < -0.15 (2)

6. An interlayer film for laminated glass, comprising at least one graphene-based material selected from the group consisting of graphene and graphite, wherein the content of the graphene-based material is 0.0005% by mass or more and 1% by mass or less.

7. The interlayer film for laminated glass according to Claim 6, comprising a resin and a colored resin layer containing the graphene-based material.

8. Measured with a thickness of 2.5 mm each and in accordance with JIS R 3106:1998, the visible light transmittance is 90.5%, the solar radiation transmittance is 87.3%, and the solar radiation reflectance is 8.3%. In the laminated glass produced by bonding two clear glass plates through the intermediate film for laminated glass disposed therebetween, the total solar radiation transmittance (Tts) and the visible light transmittance (Tv) satisfy the following formula (1). The intermediate film for laminated glass according to claim 6 or 7. (Tts - 31) / Tv < 0.6 (1)

9. Measured with a thickness of 2.5 mm each and in accordance with JIS R 3106:1998, the visible light transmittance is 90.5%, and measured in accordance with JIS Z8781, the chroma is 0.

6. In the laminated glass produced by bonding two clear glass plates through the intermediate film for laminated glass disposed therebetween, the chroma (C) and the visible light transmittance (Tv) satisfy the following formula (2). The intermediate film for laminated glass according to any one of claims 6 to 8. (C - 16) / Tv < -0.15 (2)

10. An intermediate film for laminated glass containing at least one graphene-based material selected from the group consisting of graphene and graphite, Measured with a thickness of 2.5 mm each and in accordance with JIS R 3106:1998, the visible light transmittance is 90.5%, the solar radiation transmittance is 87.3%, and the solar radiation reflectance is 8.3%. In the laminated glass produced by bonding two clear glass plates through the intermediate film for laminated glass disposed therebetween, the total solar radiation transmittance (Tts) and the visible light transmittance (Tv) satisfy the following formula (1). The intermediate film for laminated glass. (Tts - 31) / Tv < 0.6 (1)

11. Measured with a thickness of 2.5 mm each and in accordance with JIS R 3106:1998, the visible light transmittance is 90.5%, and measured in accordance with JIS Z8781, the chroma is 0.

6. In the laminated glass produced by bonding two clear glass plates through the intermediate film for laminated glass disposed therebetween, the chroma (C) and the visible light transmittance (Tv) satisfy the following formula (2). The intermediate film for laminated glass according to claim 10. (C - 16) / Tv < -0.15 (2)

12. An interlayer film for laminated glass containing at least one graphene-based material selected from the group consisting of graphene and graphite, In a laminated glass produced by adhering two clear glass plates, each having a thickness of 2.5 mm and a visible light transmittance measured in accordance with JIS R 3106:1998 of 90.5% and a chroma measured in accordance with JIS Z8781 of 0.6, through the interlayer film for laminated glass, the chroma (C) and the visible light transmittance (Tv) satisfy the following formula (2). The interlayer film for laminated glass. (C - 16) / Tv < -0.15 (2)

13. The interlayer film for laminated glass according to any one of claims 1 to 12, comprising a resin and a colored resin layer containing the graphene-based material.

14. The interlayer film for laminated glass according to claim 13, wherein the colored resin layer contains a polyvinyl acetal resin as the resin.

15. Comprising a first resin layer, a second resin layer provided on one surface side of the first resin layer, and a third resin layer provided on the other surface side of the first resin layer, The interlayer film for laminated glass according to claim 13 or 14, wherein the first resin layer is the colored resin layer.

16. The interlayer film for laminated glass according to any one of claims 1 to 15, wherein the average particle size of the graphene-based material is 40 μm or less.

17. The interlayer film for laminated glass according to any one of claims 1 to 16, wherein the thickness of the graphene-based material is 1 μm or less.

18. An interlayer film for laminated glass according to any one of claims 1 to 17, and two glass plates, A laminated glass, wherein the interlayer film for laminated glass is disposed between the two glass plates.

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