Laminated glass structure, film, and laminated film

Abstract

The present disclosure provides a laminated glass structure that can exhibit functions derived from a guest-host liquid crystal (GHLC) film without losing the functions, has a good appearance, and is highly safe. The present disclosure also provides a laminated film composed of a first intermediate film, a GHLC film, and a second intermediate film, which is included in such a laminated glass structure, and a film composed of the first intermediate film. 【Solution means】A laminated glass structure comprising a first glass plate, a first intermediate film, a GHLC film, a second intermediate film, and a second glass plate in this order, wherein the first intermediate film has a creep compliance at 90°C of 6.0×10 -5 Pa -1 or more per layer.

Description

Technical Field

[0001] The present disclosure relates to a laminated glass structure, a film, and a laminated film.

Background Art

[0002] Conventionally, a laminated glass structure in which an intermediate film is interposed between two glass plates and integrated is widely known. Since the laminated glass structure is safe because glass fragments are less likely to scatter even when it is damaged by an external impact, it is widely used in, for example, vehicles such as automobiles, airplanes, ships, and buildings.

[0003] In recent years, there has been a demand for imparting various functions to the laminated glass structure. For example, a functional layer such as a dimming film may be disposed between two glass plates. Patent Document 1 discloses a laminated glass including an intermediate film and a dimming element encapsulated in the intermediate film between two glass plates.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A laminated glass structure is generally manufactured by disposing an intermediate film between two glass plates and performing an autoclave process of pressing the glass plates and the intermediate film under high temperature and high pressure conditions such as a temperature of about 130 to 140 °C and a pressure of about 1.3 MPa after a preliminary degassing process. However, when a functional layer such as a light control film is further disposed between two glass plates, since an electronic wiring, a shielding printed portion, etc. are provided in the functional layer, a complicated step (thickness difference) is likely to occur, and pressure unevenness is also likely to occur during pressing. Therefore, air remains or foams between the intermediate film and the glass plate or the functional layer during pressing, resulting in insufficient transparency in the obtained laminated glass structure, distortion or wrinkles in the functional layer, and the appearance of the obtained laminated glass structure not being good.

[0006] In a laminated glass structure including a functional layer such as a light control film, for the purpose of protecting the end portion of the functional layer from the external environment, etc., a frame-shaped intermediate layer (also referred to as a gap filler) is disposed at the peripheral portion of the functional layer, and a structure in which this is sandwiched between a pair of intermediate layers and further sandwiched between a pair of glass plates is generally adopted (see, for example, Patent Document 1, etc.). If a laminated glass structure including a functional layer is manufactured without using a gap filler from the viewpoint of improving work efficiency, etc., air may remain or foam, and not only a good appearance cannot be obtained in the laminated glass structure, but there are also concerns such as the impact resistance being likely to be lower than when a gap filler is used.

[0007] In addition, since the functional layer is vulnerable to heat and pressure, when the glass plate and the intermediate film having the functional layer are pressed under normal high temperature and high pressure conditions, the functional layer may deteriorate or become deactivated. In particular, when the functional layer contains guest-host liquid crystal (also referred to as GHLC), color unevenness occurs in the obtained laminated glass structure due to temperature changes, pressure changes, and thermal shrinkage of the intermediate film during pressing, making it unsuitable for practical use. On the other hand, if an attempt is made to perform pressing at a low temperature, air is likely to remain or foam, and in this case as well, a laminated glass structure suitable for practical use cannot be obtained.

[0008] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a laminated glass structure that can exhibit functions derived from a GHLC film without losing them, has a good appearance, and is highly safe. The present disclosure also aims to provide a laminated film composed of a first interlayer film, a GHLC film, and a second interlayer film, and a film composed of the first interlayer film, which are included in such a laminated glass structure. [Means for Solving the Problems]

[0009] In various studies on a laminated glass structure including a GHLC film, the inventors have found that in a laminated glass structure including a first glass plate, a first interlayer film, a GHLC film, a second interlayer film, and a second glass plate in this order, when at least one of the interlayer films satisfies a predetermined creep property, air remaining or foaming during pressure bonding can be suppressed without undergoing an autoclave process under high temperature and high pressure conditions, and a laminated glass structure having a good appearance can be obtained. Such a laminated glass structure can suitably exhibit functions derived from the GHLC film without losing them, and color unevenness is sufficiently suppressed. Thus, the inventors have completed the laminated glass structure and the like of the present disclosure. That is, the present disclosure relates to the following laminated glass structure and the like.

[0010] The present disclosure 1 includes a first glass plate, a first interlayer film, a GHLC film, a second interlayer film, and a second glass plate in this order, and the first interlayer film has a creep compliance at 90 °C per layer of 6.0×10 -5 Pa -1 or more, which is a laminated glass structure. The present disclosure 2 is the laminated glass structure of the present disclosure 1, in which the first interlayer film contains a thermoplastic resin. The present disclosure 3 is the laminated glass structure of the present disclosure 1 or 2, in which the first interlayer film contains a polyvinyl acetal resin. The present disclosure 4 is the laminated glass structure of the present disclosure 3, in which the polyvinyl acetal resin has a weight average molecular weight of 220000 to 310000. The present disclosure 5 is a laminated glass structure according to any one of the present disclosures 2 to 4, wherein the first intermediate film further contains a plasticizer. The present disclosure 6 is a laminated glass structure according to the present disclosure 5, wherein the plasticizer is at least one selected from the group consisting of triethylene glycol-di-2-ethylhexanoate, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, and derivatives in which some of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups. The present disclosure 7 is a laminated film comprising the first intermediate film, the GHLC film, and the second intermediate film, which is provided in the laminated glass structure according to any one of the present disclosures 1 to 6. The present disclosure 8 is a film composed of the first intermediate film provided in the laminated glass structure according to any one of the present disclosures 1 to 6. The present disclosure 9 is a laminated glass structure according to any one of the present disclosures 1 to 6, which is produced without using a gap filler.

Advantages of the Invention

[0011] According to the present disclosure, it is possible to provide a laminated glass structure that can exhibit the functions derived from the GHLC film without losing them, has a good appearance, and is highly safe. Further, according to the present disclosure, it is also possible to provide a laminated film composed of the first intermediate film, the GHLC film, and the second intermediate film, and a film composed of the first intermediate film, which are provided in such a laminated glass structure.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0013] The laminated glass structure of the present disclosure includes a first glass plate, a first intermediate film, a GHLC film, a second intermediate film, and a second glass plate in this order. The laminated glass structure may further have one or two or more arbitrary layers between each layer, or may have two or more GHLC films as described later.

[0014] 〔Glass Plate〕 The laminated glass structure has a first glass plate and a second glass plate. Each glass plate may be, for example, either inorganic glass or organic glass, but is preferably inorganic glass. Note that the first glass plate and the second glass plate may be made of the same type of material as each other, or may be made of different materials. For example, one of the first glass plate and the second glass plate may be inorganic glass and the other may be organic glass, but it is preferable that both the first glass plate and the second glass plate are inorganic glass or organic glass.

[0015] The inorganic glass is not particularly limited, and examples thereof include clear glass, float glass, tempered glass, colored glass, polished glass, patterned glass, wired glass, lined glass, ultraviolet-absorbing glass, infrared-reflecting glass, infrared-absorbing glass, green glass, and the like.

[0016] As the organic glass, what is generally called resin glass is used. Examples thereof include (meth)acrylic plates such as polycarbonate plates and polymethyl methacrylate plates, acrylonitrile styrene copolymer plates, acrylonitrile butadiene styrene copolymer plates, polyester plates such as polyethylene terephthalate plates, fluororesin plates, polyvinyl chloride plates, chlorinated polyvinyl chloride plates, polypropylene plates, polystyrene plates, polysulfone plates, epoxy resin plates, phenolic resin plates, unsaturated polyester resin plates, polyimide resin plates, and other various organic glass plates. The resin plate may be appropriately subjected to surface treatment or the like.

[0017] The thickness of each glass plate is not particularly limited, but for example, it is preferably about 0.1 to 15 mm, and more preferably 0.5 to 5 mm. The thickness of each glass plate may be the same or different between the first glass plate and the second glass plate.

[0018] Other members may be attached to each glass plate as necessary. For example, a functional member may be attached to at least one of the first glass plate and the second glass plate. In this case, various functions are imparted to the glass plate. Other members are preferably members constituting, for example, electronic devices or optical members, and more preferably members constituting a display device. Examples of the display device include a liquid crystal display device, an organic EL display device, an LED display device, and a segment display device, and among them, a liquid crystal display device is preferable. The display device includes, for example, a display panel in which a display layer such as a liquid crystal layer or an organic EL layer, a light-emitting element, etc. are provided on a glass plate as a substrate, but the glass plate as the substrate may be used as the first glass plate and / or the second glass plate. Various functional layers such as a functional film; a conductive layer constituting an electrode, a sensor, etc.; an antireflection layer; a hard coat layer; etc. may also be laminated on each glass plate.

[0019] 〔Intermediate film〕 The laminated glass structure has at least a pair of intermediate films arranged so as to sandwich the GHLC film. Of the pair of intermediate films, one is referred to as the first intermediate film and the other is referred to as the second intermediate film. The first intermediate film and the second intermediate film may have the same configuration as each other or may be different.

[0020] The first intermediate film and the second intermediate film may each be a single-layer film having a single-layer structure or a multilayer film having a multilayer structure. When the first intermediate film and / or the second intermediate film has a plurality of layers, the plurality of layers may have the same configuration as each other or different configurations. For example, in the plurality of layers, the type and content of the constituent material (e.g., thermoplastic resin) may be the same as each other or different. When the first intermediate film has a plurality of layers, the number thereof is not particularly limited, but is, for example, 2 layers or 3 layers. When the second intermediate film has a plurality of layers, the number thereof is not particularly limited, but is, for example, 2 layers or 3 layers.

[0021] The first intermediate film has a creep compliance at 90 °C of 6.0×10 -5 Pa -1 or more per layer. Since such an intermediate film has high flexibility, for example, even if this crimping is performed under low-temperature conditions, the remaining air and foaming are sufficiently suppressed. Also, for example, even when this crimping is performed under low-pressure conditions, the remaining air and foaming are sufficiently suppressed. Therefore, the laminated glass structure of the present disclosure is excellent in transparency and has a good appearance. The above creep compliance is preferably 8.0×10 -5 Pa -1 or more, more preferably 1.0×10 -4 Pa -1 or more, and still more preferably 1.3×10 -4 Pa -1 or more. The upper limit of the above creep compliance is preferably 1.0×10 -3 Pa -1 or less, more preferably 7.0×10 -4 Pa -1 or less, and still more preferably 5.0×10 -4 Pa -1 or less. In particular, the above creep compliance is preferably 6.0×10 -5 Pa -1 or more and 1.0×10 -3 Pa -1 or less, and preferably 6.0×10 -5 Pa -1 or more and 7.0×10 -4 Pa-1 More preferably, it is as follows, 6.0×10 -5 Pa -1 or more and 5.0×10 -4 Pa -1 Even more preferably, it is as follows, 8.0×10 -5 Pa -1 or more and 5.0×10 -4 Pa -1 Even more preferably, it is as follows, 1.0×10 -4 Pa -1 or more and 5.0×10 -4 Pa -1 Particularly preferably, it is as follows, 1.3×10 -4 Pa -1 or more and 5.0×10 -4 Pa -1 Most preferably, it is as follows.

[0022] The creep compliance at 90°C per layer above is determined as follows. <Measurement method of creep compliance> As a measuring device, the dynamic viscoelasticity measuring system "MCR702e MultiDrive" (purchased in 2023) manufactured by Anton Paar is used. Using this measuring device, a circular sample with a diameter of 8 mm and a thickness of 0.76 mm prepared from one layer of the intermediate film is subjected to a shear stress of 400 Pa at a measuring temperature of 90°C for 15 minutes to obtain the creep compliance J(t). The value at the 10-minute mark of the obtained creep compliance J(t) is taken as the value of the "creep compliance at 90°C per layer" above.

[0023] Here, when the thickness of the sample (interlayer film) to be measured is less than 0.76 mm, several such samples may be stacked and subjected to press molding or the like to make the thickness of the samples uniform. If the physical properties of the sample change due to hot pressing, measurement may be performed at the original thickness without pressing. Also, when the thickness of the sample is greater than 0.76 mm, the thickness may be made uniform by press molding or the like, or measurement may be performed at the original thickness. From the viewpoint of measurement accuracy, the measured thickness of the sample is preferably 0.3 mm or more and preferably 3 mm or less.

[0024] When setting the sample in the measuring device, in order to sufficiently press-bond the sample and the jig, the gap at room temperature is set to a pressure of 5 to 10 N, and then heated to 140°C with the gap fixed. Two minutes after reaching 140°C, the temperature is started to be lowered to the measurement temperature. After holding for 2 minutes after reaching the measurement temperature, the measurement of creep compliance is started. As the measuring jig, a stainless-steel parallel plate with a diameter of 8 mm is used.

[0025] In the laminated glass structure of the present disclosure, it is only necessary for one of the pair of interlayer films (the first interlayer film) arranged to sandwich the GHLC film to satisfy the above creep compliance value. For example, when the first interlayer film is a multilayer film, at least one layer thereof only needs to satisfy the above creep compliance value. However, for example, considering the adhesion between the glass plate and the first interlayer film, it is preferable that the layer adjacent to the glass plate among the layers constituting the first interlayer film satisfies the above creep compliance value. Also, considering the adhesion between the first interlayer film and the functional layer, it is preferable that the layer adjacent to the functional layer among the layers constituting the first interlayer film satisfies the above creep compliance value, and it is more preferable that all layers satisfy the above creep compliance value.

[0026] From the same perspective, it is also preferable that the second intermediate film satisfies the above creep compliance value. When the second intermediate film is a multilayer film, at least one layer thereof only needs to satisfy the above creep compliance value. However, for example, considering the adhesion between the glass plate and the second intermediate film, it is preferable that the layer adjacent to the glass plate among the layers constituting the second intermediate film satisfies the above creep compliance value. Also, considering the adhesion between the second intermediate film and the functional layer, it is preferable that the layer adjacent to the functional layer among the layers constituting the second intermediate film satisfies the above creep compliance value. More preferably, all layers satisfy the above creep compliance value.

[0027] It is preferable that the first intermediate film and / or the second intermediate film has a glass transition temperature (Tg) of -10°C or higher. When Tg is within this range, the penetration resistance and impact resistance are further improved. More preferably, Tg is 0°C or higher, still more preferably 10°C or higher, and particularly preferably 15°C or higher. Also, it is preferable that Tg is 50°C or lower. When Tg is within this range, the adhesiveness to a glass plate or the like tends to be better. More preferably, Tg is 40°C or lower, and still more preferably 30°C or lower.

[0028] The Tg of the intermediate film is determined by viscoelasticity measurement. Specifically, it is determined as follows, for example. <Measurement Method of Tg> The test piece to be measured is stored for 12 hours in an environment of room temperature 23 ± 2°C and humidity 25 ± 5%. Then, using a viscoelasticity measuring device "ARES-G2" manufactured by TA Instruments, the viscoelasticity is measured. A parallel plate with a diameter of 8 mm is used as the jig, and the measurement is carried out under the conditions of a shear mode, a temperature decrease rate of 3°C / min from 100°C to -20°C, and conditions of a frequency of 1 Hz and a strain of 1%. In the obtained measurement results, the peak temperature of the loss tangent is taken as the glass transition temperature Tg (°C).

[0029] (Thermoplastic Resin) The first intermediate film preferably contains a thermoplastic resin. The second intermediate film also preferably contains a thermoplastic resin. That is, each intermediate film preferably has a resin layer containing a thermoplastic resin. By adjusting the weight average molecular weight of the resin, the glass transition temperature of the resin, and / or the intermolecular interaction, etc., it becomes easy to adjust the creep compliance per layer within a predetermined range. When the first intermediate film or the second intermediate film is a multilayer film, it is preferable that at least the layer satisfying the creep compliance value is the resin layer. Note that each component contained in each intermediate film may be used alone as only one kind, or two or more kinds may be used in combination.

[0030] Examples of the thermoplastic resin include (meth)acrylic resins, polyvinyl acetal resins, polyvinyl alcohol resins, polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymers (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and styrene-butadiene copolymer resins, etc. Among these, from the viewpoint of achieving both heat and humidity resistance and impact resistance, the thermoplastic resin is preferably a polyvinyl acetal resin, a polyurethane resin (PU), an ethylene-vinyl acetate copolymer resin (EVA), a saponified ethylene-vinyl acetate copolymer (EVOH), an ethylene-methacrylic acid copolymer resin, an ionomer resin, an isobutylene resin, a styrene-isoprene copolymer resin, and / or a styrene-butadiene copolymer resin. Among them, the thermoplastic resin is more preferably a polyvinyl acetal resin.

[0031] Thus, the resin layer preferably contains a polyvinyl acetal resin. That is, the first intermediate film preferably contains a polyvinyl acetal resin. The second intermediate film also preferably contains a polyvinyl acetal resin. By providing an intermediate film containing a polyvinyl acetal resin, the laminated glass structure becomes more excellent in impact resistance, and the adhesiveness of the intermediate film to various adherends (for example, GHLC film, glass plate, etc.) becomes better. Hereinafter, the polyvinyl acetal resin will be described in detail.

[0032] The polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol with an aldehyde. Each raw material of the polyvinyl acetal resin may be used alone as only one kind, or two or more kinds may be used in combination.

[0033] The aldehyde is not particularly limited. For example, aldehydes having 1 to 10 carbon atoms are preferably used. The aldehydes having 1 to 10 carbon atoms are not particularly limited. For example, n-butyl aldehyde, isobutyl aldehyde, n-valeraldehyde, 2-ethylbutyl aldehyde, n-hexyl aldehyde, n-octyl aldehyde, n-nonyl aldehyde, n-decyl aldehyde, formaldehyde, acetaldehyde, and benzaldehyde can be mentioned. Among these, the above aldehyde is preferably n-butyl aldehyde, n-hexyl aldehyde, or n-valeraldehyde, and more preferably n-butyl aldehyde. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin.

[0034] Polyvinyl alcohol 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%.

[0035] The average degree of polymerization of polyvinyl alcohol is preferably 1000 to 3000. By using such polyvinyl alcohol, the polyvinyl acetal resin is likely to have a preferable weight average molecular weight described later. The average degree of polymerization of polyvinyl alcohol is more preferably 1100 to 2500, still more preferably 1200 to 2000, and particularly preferably 1300 to 1700.

[0036] As the polyvinyl alcohol, two or more polyvinyl alcohols having different average degrees of polymerization may be used. In this case, it is preferable to produce a polyvinyl acetal resin using a mixture of two or more polyvinyl alcohols as a raw material.

[0037] When using two or more polyvinyl alcohols, for example, as the polyvinyl alcohol, it is preferable to use a first polyvinyl alcohol having an average degree of polymerization of 1500 or more and a second polyvinyl alcohol having an average degree of polymerization of 1200 or less. The average degree of polymerization of the first polyvinyl alcohol is preferably 1500 to 3500, more preferably 1600 to 2500, and still more preferably 1600 to 2000. Also, the average degree of polymerization of the second polyvinyl alcohol is preferably 200 to 1200, more preferably 300 to 900, and still more preferably 400 to 850.

[0038] When using the first polyvinyl alcohol and the second polyvinyl alcohol in combination, their blending ratios are not particularly limited. For example, with respect to 100% by mass of the total amount of the first polyvinyl alcohol and the second polyvinyl alcohol, the blending amount of the second polyvinyl alcohol is preferably 1 to 50% by mass, more preferably 3 to 40% by mass, still more preferably 5 to 35% by mass, and particularly preferably 10 to 30% by mass.

[0039] The average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 (1994) "Test Methods for Polyvinyl Alcohol". Also, when two or more polyvinyl alcohols are used as raw materials, the average degree of polymerization of polyvinyl alcohol can be estimated by calculation from the average degrees of polymerization of the respective polyvinyl alcohols.

[0040] The polyvinyl acetal resin preferably has a weight average molecular weight of 100,000 to 300,000. Thereby, the adhesiveness of the interlayer film to various adherends and the penetration resistance of the laminated glass structure are further improved. Further, by using a polyvinyl acetal resin having a weight average molecular weight within the above range, it becomes easier to adjust the creep compliance per layer of the interlayer film within the above-described range. The lower limit of the weight average molecular weight of the polyvinyl acetal resin is more preferably 180,000 or more, still more preferably 210,000 or more, and particularly preferably 220,000 or more. The upper limit of the weight average molecular weight of the polyvinyl acetal resin is more preferably 280,000 or less, still more preferably 260,000 or less, and particularly preferably 250,000 or less. The range of the weight average molecular weight of the polyvinyl acetal resin is more preferably 180,000 to 280,000, still more preferably 210,000 to 260,000, and particularly preferably 220,000 to 250,000.

[0041] The weight average molecular weight of the polyvinyl acetal resin is determined, for example, by the following measuring method using gel permeation chromatography. <Measurement method of molecular weight> The polyvinyl acetal resin is dissolved in an N-methyl-2-pyrrolidone solution to which lithium bromide is added to a concentration of 10 mM to obtain a solution having a polyvinyl acetal resin concentration of 0.05% by mass. The obtained solution is filtered using a syringe filter (manufactured by Merck, Millex-LH 0.45 μm), and then the molecular weight is measured using gel permeation chromatography (manufactured by Waters, e2690). Then, the weight average molecular weight (Mw) is calculated using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample. Note that Shodex GPC KF-806L (manufactured by Showa Denko KK) is used as the column, and an N-methyl-2-pyrrolidone solution to which lithium bromide is added to a concentration of 10 mM is used as the eluent.

[0042] The hydroxyl group content of the polyvinyl acetal resin is preferably 15 mol% or more. Thereby, the adhesiveness of the interlayer film to various adherends is likely to be good, and the obtained laminated glass structure is excellent in penetration resistance and the like. The hydroxyl group content of the polyvinyl acetal resin is preferably 38 mol% or less. Thereby, the flexibility of the interlayer film becomes good, and it is possible to prevent the obtained laminated glass structure from becoming too hard. Further, when the hydroxyl group content of the polyvinyl acetal resin is within the above range, generation of bubbles during use in a high-temperature environment is sufficiently suppressed, and the high-temperature heat resistance of the interlayer film is further improved. The lower limit of the above hydroxyl group content is more preferably 20 mol% or more, and still more preferably 25 mol% or more. The upper limit of the above hydroxyl group content is more preferably 35% or less, and still more preferably 33 mol% or less.

[0043] Even when using polyvinyl butyral resin as the polyvinyl acetal resin, from the same viewpoint, the lower limit of the hydroxyl group content is preferably 15 mol% or more, more preferably 20 mol% or more, and still more preferably 25 mol% or more. The upper limit of the hydroxyl group content of the polyvinyl butyral resin is preferably 38 mol% or less, more preferably 35% or less, and still more preferably 33 mol% or less.

[0044] The hydroxyl group content of the polyvinyl acetal resin is a value obtained by expressing as a percentage the molar fraction 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. The amount of ethylene groups to which hydroxyl groups are bonded can be measured, for example, in accordance with JIS K6728 (1977) "Test Methods for Polyvinyl Butyral".

[0045] The degree of acetalization of the polyvinyl acetal resin is preferably 47 mol% or more, more preferably 55 mol% or more, and still more preferably 60 mol% or more. The degree of acetalization of the polyvinyl acetal resin is also preferably 85 mol% or less, more preferably 80 mol% or less, and still more preferably 75 mol% or less. When the acetal group is a butyral group and the polyvinyl acetal resin is a polyvinyl butyral resin, the degree of acetalization means the degree of butyralization.

[0046] The degree of acetalization of the polyvinyl acetal resin 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 can be calculated from the results measured by a method conforming to, for example, JIS K6728 (1977) "Test Methods for Polyvinyl Butyral".

[0047] The degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less. Thereby, the moisture resistance of the interlayer film is improved. The upper limit of the degree of acetylation is more preferably 20 mol% or less, still more preferably 10 mol% or less, and particularly preferably 2 mol% or less. The lower limit of the degree of acetylation is not particularly limited, but is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more.

[0048] The degree of acetylation of the polyvinyl acetal resin is a value obtained by dividing, by the total amount of ethylene groups in the main chain, the mole fraction obtained by dividing the amount of ethylene groups to which an acetyl group is bonded, and expressing the result as a percentage. The amount of ethylene groups to which an acetyl group is bonded can be measured, for example, in accordance with JIS K6728 (1977) "Test Methods for Polyvinyl Butyral".

[0049] The polyvinyl acetal resin is preferably an unmodified polyvinyl acetal resin, but a modified polyvinyl acetal resin may also be used. A modified polyvinyl acetal resin has a structure other than an acetal group, a hydroxyl group, and an acetyl group (modifying group), and preferably has the modifying group in the side chain. Examples of the modifying group include those having a polyalkylene oxide structure in the side chain and those having an alkyl group other than an acetal group and an acetyl group (for example, having about 2 to 30 carbon atoms) in the side chain. The modification amount is not particularly limited, but is, for example, about 0.1 mol% or more and about 10 mol%. The modification amount represents the ratio of the functional group to all vinyl monomer units constituting the polyvinyl acetal resin.

[0050] When the first intermediate film and / or the second intermediate film contains a polyvinyl acetal resin, the intermediate film may further contain a thermoplastic resin other than the polyvinyl acetal resin. Examples of the thermoplastic resin other than the polyvinyl acetal resin are as described above. However, it is preferable that the main component of the resin constituting the intermediate film is a polyvinyl acetal resin. Specifically, in 100% by mass of the total amount of the resin components constituting the resin layer constituting each intermediate film (when each intermediate film includes a plurality of resin layers, each resin layer), the polyvinyl acetal resin is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, and most preferably 100% by mass. That is, it is most preferable that the resin constituting each intermediate film is only a polyvinyl acetal resin.

[0051] The polyvinyl acetal resin is preferably produced by a production method including, for example, a mixing step of mixing polyvinyl alcohol and an aldehyde, and an aging step of aging the mixture obtained in the mixing step. By the above mixing step and aging step, acetalization of polyvinyl alcohol proceeds, and thus a polyvinyl acetal resin is obtained. In addition, when producing a thermoplastic resin such as a polyvinyl acetal resin, the intermolecular interaction can be adjusted by changing the reaction conditions and aging conditions.

[0052] In the above mixing step, polyvinyl alcohol and an aldehyde may be mixed according to a conventional method. Further, a catalyst such as an acid catalyst for promoting the acetalization reaction may be added in addition to polyvinyl alcohol and the aldehyde. For example, an aldehyde may be added to a mixture obtained by adding an acid catalyst to polyvinyl alcohol under low temperature conditions of about 0 to 40°C. Further, when two or more kinds of polyvinyl alcohol are used in combination (for example, when two or more kinds of polyvinyl alcohol having different molecular weights are used), the two or more kinds of polyvinyl alcohol may be mixed with the aldehyde.

[0053] In the above aging step, for example, after adding a catalyst such as an acid catalyst to the mixture (reaction mixture) obtained by the above mixing step, it is heated to the aging temperature and held at the aging temperature for a certain period of time. After the reaction mixture is held at the aging temperature for a certain period of time, it is appropriately cooled and then neutralized, and thereafter, washing with water, drying, etc. may be performed as necessary.

[0054] Examples of the acid catalyst that can be added in the above mixing step and aging step include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, boric acid, and sulfuric acid. Further, in the above aging step, the concentration of the acid catalyst is preferably adjusted to, for example, about 0.5% by mass or more and 5% by mass or less, and more preferably adjusted to about 1% by mass or more and 2.5% by mass or less.

[0055] The aging temperature in the above aging step may be relatively low. For example, 40°C or higher and 60°C or lower is preferable, 35°C or higher and 60°C or lower is more preferable, and 40°C or higher and 57°C or lower is still more preferable. The time for holding at the above aging temperature (aging time) may be longer than a certain time. For example, 75 minutes or more and 180 minutes or less is preferable, 90 minutes or more and 150 minutes or less is more preferable, and 100 minutes or more and 140 minutes or less is still more preferable. When the aging temperature and the aging time are within the above ranges respectively, it is presumed that the hydroxyl groups are likely to be uniformly distributed in the polyvinyl acetal resin molecule, and thereby, it is considered that the low molecular weight components are reduced and the molecular weight distribution becomes smaller.

[0056] (Plasticizer) When the first intermediate film and / or the second intermediate film contains a thermoplastic resin, it is preferable that the intermediate film further contains a plasticizer. That is, it is preferable that the resin layer further contains a plasticizer. By the intermediate film further containing a plasticizer in addition to the thermoplastic resin, the intermediate film becomes more flexible, and the adhesiveness of the intermediate film to various adherends and the penetration resistance of the laminated glass structure obtained using the intermediate film are further improved. Further, by adjusting the type and content of the plasticizer, it becomes easier to adjust the creep compliance per layer of the intermediate film within a predetermined range.

[0057] Examples of the plasticizer include, for example, organic ester plasticizers; organic phosphate plasticizers such as organic phosphite plasticizers; organic ether plasticizers such as polyalkylene glycol-based plasticizers; alcohol-based plasticizers; and the like. Among these, the plasticizer is preferably an organic ester plasticizer and / or an organic ether-based plasticizer.

[0058] Preferable examples of the organic ester plasticizer include monobasic organic acid esters and polybasic organic acid esters.

[0059] Examples of the monobasic organic acid ester include esters of glycol and a monobasic organic acid. The glycol is preferably a polyalkylene glycol or a monoalkylene glycol. The number of carbon atoms of each alkylene unit constituting the polyalkylene glycol and the monoalkylene glycol is preferably 2 to 4, more preferably 2 or 3. In the polyalkylene glycol, the repeating number of the alkylene unit is preferably 2 to 10, more preferably 2 to 4. Specific examples of the glycol include, for example, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, butylene glycol and the like. Examples of the monobasic organic acid include organic acids having 3 to 10 carbon atoms, specifically, for example, butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, n-octylic acid, 2-ethylhexanoic acid, n-nonanoic acid, decylic acid and the like.

[0060] Specific examples of the monobasic organic acid ester 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, 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 dicaprate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, ethylene glycol di-2-ethylbutyrate, 1,2-propylene 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, and the like.

[0061] Examples of the polybasic organic acid ester include ester compounds of a dibasic organic acid having 4 to 12 carbon atoms and an alcohol having 4 to 10 carbon atoms. Examples of the dibasic organic acid having 4 to 12 carbon atoms include adipic acid, sebacic acid, azelaic acid, and the like. The alcohol having 4 to 10 carbon atoms may have a linear structure, a branched structure, or a cyclic structure.

[0062] Specific examples of the polybasic organic acid esters include, for example, dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, diisononyl adipate, heptyl nonyl adipate, dibutyl carbitol adipate, mixed adipic acid esters, and the like. The polybasic organic acid esters may also be oil-modified sebacic acid alkyds and the like. Examples of the mixed adipic acid esters include adipic acid esters prepared from two or more alcohols selected from the group consisting of alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms.

[0063] The organic ester plasticizer is not limited to the complete esters of the above-mentioned esters and may also be a partial ester. The organic ester plasticizer may be, for example, a partial ester of a glycol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol. Specific examples include, for example, triethylene glycol-mono-2-ethylhexanoate and the like.

[0064] The organic ester plasticizer may also be a partial ester of a trivalent or higher alcohol such as glycerin and a monobasic organic acid. The number of carbon atoms of the monobasic organic acid is preferably, for example, 3 to 24, more preferably 6 to 18. Specific examples include, for example, mono- or diesters of glycerin and stearic acid, mono- or diesters of glycerin and 2-ethylhexanoic acid, and the like.

[0065] Among the above-mentioned organic ester plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferably used.

[0066] Preferred examples of the organic phosphorus plasticizers include organic phosphate plasticizers, organic phosphite plasticizers, and the like. Specific examples of the organic phosphorus plasticizers include phosphate esters such as tributoxyethyl phosphate, isodecyl phenyl phosphate, and triisopropyl phosphate.

[0067] Preferred examples of the organic ether plasticizer include polyalkylene glycol plasticizers. Examples of polyalkylene glycol plasticizers include polyoxyalkylene compounds having a polyoxyalkylene structure, specifically, polyhydric alcohol compounds such as glycols; ester compounds of glycols with monobasic or polybasic organic acids; ether compounds of monohydric or polyhydric alcohols with polyoxyalkylene; and the like. Here, examples of glycols include polyoxyalkylene glycols and their derivatives, and examples of polyoxyalkylene include polyoxyethylene, polyoxypropylene, polyoxybutylene, random copolymers or block copolymers thereof, and the like. The polyoxyalkylene compound may be a polyhydric alcohol compound, an ester compound, an ether compound, or other compounds as described above.

[0068] Examples of polyoxyalkylene compounds include polyoxyalkylene or its derivatives. More specifically, polyoxyalkylene glycols composed of polyoxyalkylene, ether compounds of polyoxyalkylene and polyhydric alcohols, and the like can be mentioned. All of these may have hydroxyl groups at all terminals, or a part or all of the terminal hydroxyl groups may be derivatives in which a hydrogen atom is substituted with an alkyl group or an acyl group. The carbon number of the alkyl group and the acyl group is not particularly limited, but may be about 1 to 8, preferably 1 to 4.

[0069] Examples of polyoxyalkylene glycols include polyoxyethylene polyoxypropylene glycols such as polyethylene glycol (polyoxyethylene glycol), polypropylene glycol (polyoxypropylene glycol), poly(ethylene oxide / propylene oxide) block copolymer, poly(ethylene oxide / propylene oxide) random copolymer, and polyoxybutylene glycols such as polytetramethylene glycol.

[0070] Examples of the ether compound of polyoxyalkylene and polyhydric alcohol include ether compounds of polyhydric alcohols such as glycerol, diglycerol, trimethylolpropane, erythritol, pentaerythritol, and bisphenol A with polyoxyalkylene. Specifically, examples include polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, and the like. Further, examples of derivatives in which some or all of the hydrogen atoms of the terminal hydroxyl group are substituted with an alkyl group or an acyl group include the above polyoxyalkylene glycols and derivatives in which some or all of the hydrogen atoms of the terminal hydroxyl group of the ether compound are substituted with an alkyl group or an acyl group. Specifically, examples include polyoxyethylene glycol monomethyl ether, polyoxyethylene glycol dimethyl ether, polyoxypropylene glycol monomethyl ether, polyoxypropylene glycol dimethyl ether, polyoxyethylene polyoxypropylene glycol monomethyl ether, polyoxyethylene polyoxypropylene glycol dimethyl ether, polyoxyethylene glycol monobutyl ether, polyoxypropylene glycol monobutyl ether, polyoxyethylene polyoxypropylene monobutyl ether, and the like.

[0071] Among the above-described polyoxyalkylene compounds, compounds having a polyoxyethylene structure, a polyoxypropylene structure, or a polyoxyethylene polyoxypropylene structure are preferred. Among them, compounds having a polyoxypropylene structure or a polyoxyethylene polyoxypropylene structure are more preferred. Specifically, the polyoxyalkylene compound is preferably polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or a derivative in which some of the hydrogen atoms of their terminal hydroxyl groups are substituted with an alkyl group.

[0072] Preferred examples of the alcohol-based plasticizer include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, pentaerythritol, etc. Among these, trimethylolpropane is preferred.

[0073] Among the above-mentioned compounds, the plasticizer is preferably at least one selected from the group consisting of triethylene glycol-di-2-ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, and derivatives in which a part of the hydrogen atoms of the terminal hydroxyl groups are substituted with an alkyl group, and 3GO is more preferred.

[0074] When the resin layer further contains a plasticizer, the content of the plasticizer (the total amount when two or more are included) is preferably 10 parts by mass or more with respect to 100 parts by mass of the thermoplastic resin contained in the resin layer (one layer). Thereby, the intermediate film becomes moderately flexible, and the adhesiveness of the intermediate film to various adherends and the penetration resistance of the laminated glass structure are further improved. The content of the plasticizer with respect to 100 parts by mass of the thermoplastic resin is more preferably 15 parts by mass or more, still more preferably 30 parts by mass or more, particularly preferably 35 parts by mass or more. The content of the plasticizer is also preferably 100 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin. Thereby, the separation of the plasticizer from the intermediate film is sufficiently prevented. The content of the plasticizer with respect to 100 parts by mass of the thermoplastic resin is more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less, particularly preferably 50 parts by mass or less, and most preferably 45 parts by mass or less.

[0075] (Other additives) The first intermediate film and / or the second intermediate film may also appropriately contain known additives that can be used in combination with the thermoplastic resin. That is, for example, the above resin layer may contain known additives. Examples of additives other than plasticizers include, for example, ultraviolet absorbers, heat insulating agents, colorants, infrared absorbers, antioxidants, light stabilizers, adhesion adjusters, fluorescent brighteners, crystal nucleating agents, and the like. Each additive may be used alone or in combination of two or more.

[0076] (Ultraviolet absorber) When the above intermediate film contains an ultraviolet absorber, deterioration of the GHLC film due to ultraviolet rays is sufficiently suppressed. For example, it is preferable that the above resin layer included in at least one of the first intermediate film and the second intermediate film further contains an ultraviolet absorber.

[0077] The ultraviolet absorber is not particularly limited. For example, compounds having a malonic acid ester structure, compounds having an oxalic acid anilide structure, compounds having a benzotriazole structure, compounds having a benzophenone structure, compounds having a triazine structure, compounds having a benzoate structure, compounds having a hindered amine structure, compounds having an indole structure, and the like can be mentioned. Among these, from the viewpoint of excellent compatibility with the thermoplastic resin and weather resistance, the ultraviolet absorber is preferably a compound having a benzotriazole structure. Examples of the compound having a benzotriazole structure include Tinuvin234, Tinuvin326, Tinuvin327, Tinuvin640, Tinuvin928 (manufactured by BAF); Eversorb88, Eversorb109 (manufactured by Everlight Chemical), etc. are commercially available.

[0078] When the above resin layer contains an ultraviolet absorber, the content of the ultraviolet absorber (the total amount in the case of containing two or more kinds) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, in 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the ultraviolet absorber is also preferably 5% by mass or less, more preferably 3% by mass or less, in 100% by mass of the total amount of the materials constituting one layer of the resin layer.

[0079] (Heat insulating agent) When the intermediate film contains a heat insulating agent, deterioration of the GHLC film due to heat can be sufficiently suppressed. For example, it is preferable that the resin layer included in at least one of the first intermediate film and the second intermediate film further contains a heat insulating agent. Further, at least one of the first intermediate film and the second intermediate film may have a layer made of a heat insulating agent (for example, a layer made of the following heat insulating particles) or a layer containing a heat insulating agent separately from or in addition to the resin layer.

[0080] The heat insulating agent is a material capable of absorbing infrared rays (also referred to as heat rays) of 780 nm or more. Specifically, the heat insulating agent is preferably heat insulating particles. The heat insulating particles are made of an inorganic material, 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); tungsten oxide particles such as thallium-doped tungsten oxide particles and rubidium-doped tungsten oxide particles; and the like. Further, heat insulating particles other than these may be used. Among these, from the viewpoint of high heat ray shielding function, the heat insulating agent is preferably metal oxide particles, more preferably at least one selected from the group consisting of ATO particles, GZO particles, ITO particles, and CWO particles, and ITO particles and / or CWO particles are more preferable.

[0081] The average particle diameter of the heat shielding particles preferably has a lower limit of 10 nm or more, more preferably 20 nm or more. When the average particle diameter is in such a range, the heat ray shielding property by the heat shielding particles is further enhanced. Further, the average particle diameter of the heat shielding particles preferably has an upper limit of 100 nm or less, more preferably 80 nm or less, and still more preferably 50 nm or less. When the average particle diameter is in such a range, it becomes difficult to shield visible light by the heat shielding particles. Note that the "average particle diameter" referred to here indicates the volume average particle diameter. The average particle diameter can be measured using a particle size distribution measuring device (such as "UPA-EX150" manufactured by Nikkiso Co., Ltd.).

[0082] The heat shielding agent may also be an organic material or an organic-inorganic composite material (also referred to as a shielding compound) capable of absorbing infrared rays, and these are also near-infrared absorbers. The near-infrared absorber has an absorption maximum in the near-infrared region, and the absorption maximum exhibits the maximum absorption among the absorption maxima existing in the region of wavelength 380 nm to 2500 nm. Specifically, the near-infrared absorber has the maximum absorption in a wavelength region of 720 nm or more, preferably in a wavelength region of 750 nm or more and 2000 nm or less.

[0083] The heat shielding compound is preferably at least one selected from the group consisting of 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 the phthalocyanine compound, naphthalocyanine compound, and anthracyanine compound, the metal atom serves as the central metal of each of the naphthalocyanine skeleton, naphthalocyanine skeleton, and anthracyanine skeleton.

[0084] Among the above, the heat shielding compound is more preferably at least one selected from the group consisting of phthalocyanine compounds and naphthalocyanine compounds, and still more preferably a phthalocyanine compound. Further, as the above metal atom, a vanadium atom is preferable. Therefore, as the heat shielding compound, a phthalocyanine compound containing a vanadium atom is particularly preferable. The vanadium atom generally exists in a state where an oxygen atom is bonded (V=O). Further, as the heat shielding agent, it is also preferable to use tungsten oxide particles and a phthalocyanine compound in combination, and more preferably to use CWO particles and a phthalocyanine compound in combination.

[0085] When the above resin layer contains a heat shielding agent, the content of the heat shielding agent (the total amount in the case of containing two or more kinds) is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.15% by mass or more, based on 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the heat shielding agent is also preferably 1.5% by mass or less, more preferably 1.2% by mass or less, and still more preferably 0.9% by mass or less, based on 100% by mass of the total amount of the materials constituting one layer of the resin layer.

[0086] (Colorant) When the above intermediate film contains a colorant, the laminated glass structure is favorably colored in a desired color tone, enhancing the design property. For example, it is preferable that the above resin layer included in at least one of the first intermediate film and the second intermediate film further contains a colorant. Examples of the colorant include pigments or dyes, etc., and both a pigment and a dye may be used in combination. Note that there are also colorants classified into both pigments and dyes.

[0087] Examples of the pigment include perylene compounds, threne compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, perinone compounds, phthalocyanine compounds, indanthrene compounds, indigo compounds, isoindolinone compounds, nickel complex compounds, methine compounds, azomethine compounds, dioxazine, azo compounds, and carbon black, etc.

[0088] Examples of the dye include perylene compounds, threne compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, perinone compounds, phthalocyanine compounds, indanthrene compounds, indigo compounds, isoindolinone compounds, nickel complex compounds, methine compounds, azomethine compounds, dioxazine, and azo compounds.

[0089] When the resin layer contains a colorant, the content of the colorant (total amount when two or more kinds are included) is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, and still more preferably 0.001% by mass or more in 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the dye is also preferably 0.15% by mass or less, more preferably 0.12% by mass or less in 100% by mass of the total amount of the materials constituting the resin layer.

[0090] When the interlayer film contains a pigment as a colorant in particular, the content of the pigment (total amount when two or more kinds are included) is preferably 0.0001% by mass or more, more preferably 0.01% by mass or more, and still more preferably 0.02% by mass or more in 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the pigment is also preferably 0.15% by mass or less, more preferably 0.12% by mass or less in 100% by mass of the total amount of the materials constituting the resin layer. Note that the pigment that can be contained in the interlayer film may be only one kind, or two or more kinds, or three or more kinds, or may be 10 kinds or less, or 5 kinds or less.

[0091] When the interlayer film contains a dye as a colorant in particular, the content of the dye (the total amount when two or more kinds are contained) is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, and still more preferably 0.001% by mass or more, based on 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the dye is also preferably less than 0.015% by mass, more preferably 0.01% by mass or less, based on 100% by mass of the total amount of the materials constituting one resin layer. Note that the dye that can be contained in the interlayer film may be only one kind, two or more kinds, three or more kinds, ten or less kinds, or five or less kinds.

[0092] (Thickness) The thickness of the first interlayer film of the laminated glass structure is not particularly limited, but the layer thickness of the interlayer film (when it is a multilayer film, it means the total thickness) is preferably 100 μm or more, more preferably 200 μm or more, and still more preferably 300 μm or more. The thickness of the second interlayer film is also not particularly limited, but the layer thickness of the interlayer film (when it is a multilayer film, it means the total thickness) is preferably 100 μm or more, more preferably 200 μm or more, and still more preferably 300 μm or more. By each interlayer film having a thickness of a certain level or more, the remaining air and foaming during the crimping with the glass plate are further sufficiently suppressed.

[0093] Also, the film thickness (total thickness) of the first interlayer film is preferably 2000 μm or less, more preferably 1300 μm or less, still more preferably 1000 μm or less, and particularly preferably 800 μm or less. The film thickness (total thickness) of the second interlayer film is also preferably 2000 μm or less, more preferably 1300 μm or less, still more preferably 1000 μm or less, and particularly preferably 800 μm or less. By the thickness of each interlayer film being a certain level or less, it is possible to prevent the laminated glass structure from becoming thicker than necessary.

[0094] In the first intermediate film, it is preferable that the thickness of the layer satisfying the above creep compliance value occupies a ratio of a certain level or more in the total thickness of the first intermediate film. Thereby, the residual air and foaming during the pressure bonding with the glass plate are further sufficiently suppressed. For example, when the first intermediate film is a multilayer film, when the film thickness (total thickness) of the first intermediate film is taken as 100%, the thickness of the layer satisfying the above creep compliance value is preferably 10 to 100%, more preferably 30 to 100%, still more preferably 50 to 100%, particularly preferably 75 to 100%, and most preferably 100%.

[0095] Also in the second intermediate film, it is preferable that the thickness of the layer satisfying the above creep compliance value occupies a ratio of a certain level or more in the total thickness of the second intermediate film. Thereby, the residual air and foaming during the pressure bonding with the glass plate are further sufficiently suppressed. For example, when the second intermediate film is a multilayer film, when the film thickness (total thickness) of the second intermediate film is taken as 100%, the thickness of the layer satisfying the above creep compliance value is preferably 10 to 100%, more preferably 30 to 100%, still more preferably 50 to 100%, particularly preferably 75 to 100%, and most preferably 100%.

[0096] Further, when the total thickness of the laminated glass structure is taken as 100%, the thickness of the layer satisfying the above creep compliance value (when including two or more layers of the layer, the total thickness thereof) is preferably 10 to 50%, and more preferably 20 to 40%.

[0097] (Uneven shape) Regarding at least one of the first intermediate film and the second intermediate film, at least one surface of the intermediate film preferably has an uneven shape. More specifically, it is preferable that at least one surface of the intermediate film has a plurality of concave portions and a plurality of convex portions, and it is more preferable that both surfaces of the intermediate film have a plurality of concave portions and a plurality of convex portions. Further, when the first intermediate film and / or the second intermediate film is a multilayer film, it is preferable that one side or both sides of the outermost layer of the intermediate film have an uneven shape.

[0098] The concave portion preferably has a groove shape with a continuous bottom. The groove shape with a continuous bottom is also referred to as a "scored line shape". Therefore, for at least one of the first intermediate film and the second intermediate film, at least one surface of the intermediate film preferably has a scored line-shaped concave portion, and more preferably both surfaces of the intermediate film have a scored line-shaped concave portion. For example, when attempting to preliminarily bond a glass plate and an intermediate film with a rubber bag to obtain a laminated glass structure, the ends may be temporarily bonded first, and the air near the center may be difficult to escape. However, when the surface of the intermediate film has a scored line-shaped concave portion, the air near the center can also escape easily, so the adhesiveness during preliminary bonding is improved.

[0099] For at least one of the first intermediate film and the second intermediate film, it is preferable that at least one surface of the intermediate film has a plurality of scored line-shaped concave portions. In this case, it is preferable that the plurality of scored line-shaped concave portions are arranged in parallel. Among them, it is more preferable that adjacent scored line-shaped concave portions are parallel and regularly arranged. The ease of air escape (also referred to as degassing property) when pressing a laminated film in which an intermediate film is laminated between a pair of glass plates is closely related to the connectivity and smoothness of the bottom of the concave portions on the surface of the intermediate film. By making the concavo-convex shape on at least one surface of the intermediate film such that adjacent scored line-shaped concave portions are parallel and regularly arranged, the connectivity of the bottom is improved, and the degassing property is further improved.

[0100] The interval Sm between adjacent scored line-shaped concave portions is preferably 100 μm or more and preferably 500 μm or less. When the interval Sm of the scored line-shaped concave portions is within this range, a more excellent degassing property is exhibited. The lower limit of the interval Sm of the scored line-shaped concave portions is more preferably 160 μm or more, and the upper limit is more preferably 350 μm or less, and even more preferably 250 μm or less. The interval Sm of the scored line-shaped concave portions is obtained by observing the first surface and the second surface (observation range: 20 mm × 20 mm) of the intermediate film using an optical microscope (manufactured by SONIC, "BS-D8000III"), measuring the interval between adjacent concave portions, and then calculating the average value of the shortest distance between the bottommost parts of adjacent concave portions.

[0101] The regularly arranged parallel notch-shaped recesses are preferably such that adjacent notch-shaped recesses are parallel and arranged in parallel at equal intervals, but the intervals between all adjacent notch-shaped recesses do not have to be equal. The notch-shaped recesses do not have to have a groove shape in which all bottoms are continuous, and may have a dividing wall in a part of the bottom. Also, if adjacent recesses are parallel and regularly arranged, the groove shape of the bottom does not have to be linear. For example, the groove shape of the bottom may be wavy or zigzag.

[0102] In the intermediate film having an uneven shape on at least one surface, the surface roughness (RzJIS94) of the surface having the uneven shape is preferably 10 to 80 μm. When the surface roughness is within this range, the intermediate film can exhibit excellent degassing properties. The above surface roughness is more preferably 20 to 65 μm, and still more preferably 20 to 50 μm.

[0103] The surface roughness (RzJIS94) can be measured in accordance with JIS B0601 (1994). Here, when the recesses of the surface uneven shape are notch-shaped, the measurement is performed in the vertical direction so as to cross the direction in which the recesses in the notch direction are continuous. For example, as a measuring instrument, "Surfcorder SE300" manufactured by Kosaka Laboratory Ltd. etc. is used, the cut-off value at the time of measurement is 2.5 mm, the reference length is 2.5 mm, the measurement length is 12.5 mm, the preliminary length is 2.5 mm, the feed speed of the touch probe is 0.5 mm / second, and the touch probe shape is one with a tip radius of 2 μm and a tip angle of 60°. Also, the environment at the time of measurement is under 23°C and 30RH%. The intermediate film to be measured is measured after being left standing for 3 hours or more in the environment at the time of measurement.

[0104] Also, in the intermediate film having an uneven shape on at least one surface, the surface roughness (Rc) of the surface having the uneven shape is preferably 10 to 40 μm. When the surface roughness is within this range, the intermediate film can exhibit excellent degassing properties. The above surface roughness (Rc) is more preferably 15 to 35 μm, and still more preferably 19 to 30 μm. Note that the surface roughness (Rc) can be measured in accordance with JIS B0601 (2013).

[0105] Each intermediate film can be manufactured, for example, by extrusion molding or press molding, etc., but it is preferably manufactured by extrusion molding. Further, as a method for forming an uneven shape on the surface of the intermediate film, for example, an embossing roll method, a calendar roll method, a profile extrusion method, a melt fracture method, etc. can be mentioned. Among them, the embossing roll method is preferably adopted.

[0106] Here, the first intermediate film (that is, the intermediate film in which the above-mentioned creep compliance per layer of the intermediate film is within a predetermined range) included in the laminated glass structure of the present disclosure itself is also something found by the inventors. That is, the film composed of the first intermediate film included in the laminated glass structure is also included in the present disclosure.

[0107] 〔GHLC film〕 The laminated glass structure has a GHLC film located between the first intermediate film and the second intermediate film.

[0108] Normally, when an autoclave under high temperature and high pressure conditions is applied to the GHLC film, its function is likely to deteriorate or deactivate. Also, due to temperature changes and pressure changes during crimping, and thermal shrinkage of the intermediate film, color unevenness occurs in the obtained laminated glass structure, making it unsuitable for practical use. However, since the laminated glass structure of the present disclosure can be preferably manufactured even by an autoclave at low temperature, the GHLC film can be incorporated into the laminated glass structure without deactivation. Therefore, the laminated glass structure of the present disclosure can effectively exhibit the functions derived from the GHLC film and sufficiently suppress the occurrence of color unevenness. Further, since the GHLC film is provided with electronic wiring, shielding printing parts, etc., complex steps (thickness differences) are likely to occur, and therefore, air is likely to remain or foam between the intermediate film and the glass plate or the GHLC film during crimping. However, in the present disclosure, even when crimping is performed at low temperature, the occurrence of such air remaining and foaming is sufficiently suppressed, so that the obtained laminated glass structure has excellent transparency and good appearance. Also, a laminated glass structure (for example, window glass) incorporating the GHLC film has high added value such as excellent design.

[0109] A GHLC film is a film-like member provided with GHLC (Guest-Host Liquid Crystal). Specifically, the GHLC film preferably includes two resin films and a GHLC layer disposed between the two resin films. Since the surfaces of the GHLC film having such a configuration that are in contact with the first intermediate film and the second intermediate film respectively are made of a resin material, the adhesiveness to these intermediate films can be improved. The GHLC layer is composed of, for example, a liquid crystal composition in which a dichroic dye is dissolved as a guest in a host liquid crystal. Since the dichroic dye has a uniaxial light absorption axis and absorbs only light vibrating in the direction of the light absorption axis, the GHLC film provided with the GHLC layer can change the orientation of the dichroic dye in accordance with the movement of the liquid crystal by an electric field and control the direction of the light absorption axis, thereby changing the transmission state of the liquid crystal layer.

[0110] The resin film used for the GHLC film is not particularly limited. For example, polyester resin films such as polyethylene terephthalate (PET) film and polyethylene naphthalate (PEN) film; (meth)acrylic resin film; triacetyl cellulose (TAC) film; polyethersulfone (PES) resin film; polyimide resin film; etc. may be mentioned. Among these, from the viewpoint of handleability and the like, the resin film is preferably a polyester resin film, and more preferably a PET film. In addition, a conductive layer for forming an electrode may be provided on the surface on the GHLC layer side of each of the two resin films.

[0111] In order to control the thickness (cell gap) of the GHLC layer, spacers may be disposed between the two resin films. The spacer is not particularly limited. For example, it may be a bead spacer or may be formed, for example, in a cylindrical shape from a photoresist. The shape of the spacer is not particularly limited, and examples thereof include a spherical shape, a cylindrical shape, and a prismatic shape.

[0112] The laminated film composed of the first interlayer film, the GHLC film, and the second interlayer film included in the laminated glass structure of the present disclosure is useful for various applications other than the application of providing the laminated glass structure. Such a laminated film composed of the first interlayer film, the GHLC film, and the second interlayer film is included in the present disclosure.

[0113] The above laminated film can be manufactured by, for example, thermocompression bonding the first interlayer film, the GHLC film, and the second interlayer film. Further, when incorporating the above laminated film into the laminated glass structure, thermocompression bonding may be performed by first thermocompression bonding the first interlayer film, the GHLC film, and the second interlayer film to form a laminated film, and then pressure bonding the laminated film to a glass plate to form the laminated glass structure. Further, when the first interlayer film, the GHLC film, and the second interlayer film before pressure bonding are arranged between two glass plates and the glass plate and the above laminated film are pressure bonded, the first interlayer film, the GHLC film, and the second interlayer film may be pressure bonded together.

[0114] Here, it is preferable to arrange the first interlayer film, the GHLC film, and the second interlayer film so that the GHLC film having a planar area smaller than each interlayer film is surrounded by each interlayer film in a plan view (see, for example, FIGS. 2 and 3 described later). At that time, it is not necessary to arrange a gap filler on the outer periphery of the GHLC film.

[0115] 〔Layer structure〕 The laminated glass structure is composed of a structure including a pair of intermediate films (i.e., a first intermediate film and a second intermediate film) sandwiching a GHLC film between a pair of glass plates (i.e., a first glass plate and a second glass plate). For example, the first intermediate film is preferably adhered to the first glass plate and the GHLC film to join them, and the second intermediate film is preferably adhered to the second glass plate and the GHLC film to join them. Thereby, the pair of glass plates, the pair of intermediate films, and the GHLC film are integrated. The layer structure in such a mode is represented by G1 / F1 / Z / F2 / G2 (see FIG. 1). G1 represents the first glass plate, G2 represents the second glass plate, F1 represents the first intermediate film, F2 represents the second intermediate film, and Z represents the GHLC film. FIG. 1 is a schematic diagram showing an example of the layer structure of the laminated glass structure.

[0116] In the above, an embodiment in which two intermediate films are provided and one GHLC film is provided between a pair of glass plates has been exemplified. However, three or more intermediate films and two or more GHLC films may be provided between a pair of glass plates. In this case, it is preferable that the intermediate films and the GHLC films are alternately arranged, and it is preferable that intermediate films are arranged at the positions closest to each glass plate. For example, when three or more intermediate films and two or more GHLC films are provided between a pair of glass plates, the layer structure of the laminated glass structure is preferably G1 / F3 / Z1 / F4 / Z2 / F5 / G2. Z1 and Z2 represent the GHLC film, which may be the same or different. F3, F4, and F5 represent the intermediate films, which may be the same or different. At least one of the intermediate films F3, F4, and F5 is the above-described first intermediate film (i.e., the intermediate film in which the above-described creep compliance per layer of the intermediate film is within a predetermined range), and the other intermediate films may be the above-described second intermediate films.

[0117] 〔Various physical properties〕 In the laminated glass structure of the present disclosure, it is preferable that the first glass plate, the first intermediate film, the GHLC film, the second intermediate film, and the second glass plate have a curved shape with convex portions in the same direction as each other. For example, when the laminated glass structure has the configuration shown in FIG. 1, the above-described shape means that the glass plates G1 and G2, the intermediate films F1 and F2, and the GHLC film are all curved so as to have convex portions in the same direction (for example, the downward direction in FIG. 1). Since the laminated glass structure has the first intermediate film with low rigidity and high flexibility as described above, various shapes can be realized. Further, it is preferable that the radius of curvature of the inner surface (i.e., the concave curved surface) of each glass plate, each intermediate film, and the GHLC film is 1000 to 20000 mm.

[0118] In the laminated glass structure, when the thickness of the central portion of the laminated glass structure is taken as 100%, it is preferable that the thickness of the end portion of the laminated glass structure is 99% or less. The central portion of the laminated glass structure means the centroid (the central portion in plan view) of the laminated glass structure. Thereby, the intrusion of moisture from the end portion is sufficiently suppressed, so that the laminated glass structure has excellent moisture resistance, and the functions derived from the GHLC film are more effectively exhibited. When arranging the glass plate, the intermediate film, and the GHLC film, if the centroids of the respective members are arranged to overlap, the central portion of the laminated glass structure corresponds to the central portion (b) of the region having the above-described GHLC film.

[0119] In the laminated glass structure, it is preferable that the maximum value of the ultraviolet transmittance at a wavelength of 370 to 400 nm is 30% or less. The "maximum value of the ultraviolet transmittance at a wavelength of 370 to 400 nm" more precisely refers to the highest transmittance among the transmittances measured at each wavelength of 370 to 400 nm. When the above ultraviolet transmittance is within the above range, the deterioration of the GHLC film due to ultraviolet rays is more sufficiently suppressed. The maximum value of the above ultraviolet transmittance is more preferably 20% or less. The ultraviolet transmittance can be measured in accordance with JIS R3106 (1998).

[0120] 〔Method for manufacturing a laminated glass structure〕 The laminated glass structure of the present disclosure is preferably manufactured by a method in which the above-described laminated film is disposed between a pair of glass plates and these are bonded together by pressure bonding to obtain a laminated glass structure.

[0121] In the above manufacturing method, first, a first glass plate, a second glass plate, and the above-described laminated film disposed between these glass plates or each member (each intermediate film and GHLC film) constituting the above-described laminated film are prepared.

[0122] As described above, a functional member may be attached to at least one of the first glass plate and the second glass plate, but the functional member is preferably attached to the glass plate before being integrated into the laminated glass structure. Therefore, as at least one of the first glass plate and the second glass plate used in the above manufacturing method, a glass plate to which a functional member is attached may be prepared. For example, as described above, when the glass plate constitutes a substrate of a display device, a display device may be prepared as at least one of the first glass plate and the second glass plate.

[0123] Next, in the above manufacturing method, it is preferable to dispose the above-described laminated film between the first glass plate and the second glass plate and bond these together to integrate them to obtain a laminated glass structure. Also, it is preferable to dispose each member (that is, each intermediate film and GHLC film) constituting the above-described laminated film between the first glass plate and the second glass plate and bond these together to integrate them to obtain a laminated glass structure in which the above-described laminated film is incorporated. Here, each member constituting the above-described laminated film may be disposed according to the layer structure of the obtained laminated glass structure. For example, they may be disposed between the first glass plate and the second glass plate in the order of the first intermediate film, the GHLC film, and the second intermediate film.

[0124] The above lamination (also referred to as bonding or main bonding) may be performed in a two-step process where pre-bonding is followed by main bonding, or it may be performed in one step, but a two-step bonding is preferred. The pre-bonding may be performed by a vacuum back, a ring back, a nipper roll, or other pressing machines. The main bonding is preferably performed in an autoclave, but may also be performed by other pressing machines. When bonding in one step, it is preferably performed by a vacuum back or a ring back, but may also be performed by other pressing machines.

[0125] In the above manufacturing method, it is preferable to perform the above lamination under low-temperature conditions, and it is more preferable to perform the above lamination under low-temperature and low-pressure conditions. By performing the lamination under low-temperature conditions or low-pressure conditions, deterioration or deactivation of the GHLC film is sufficiently prevented. Also, when a functional member or the like is attached to the glass plate, deterioration or deactivation of the member is sufficiently prevented.

[0126] From the viewpoint of more reliably preventing deterioration or deactivation of the GHLC film or the like, the temperature during the above lamination is preferably 110°C or lower, and more preferably 100°C or lower. Also, from the viewpoint of further preventing the generation and foaming of residual air, the temperature during lamination is preferably 60°C or higher, and more preferably 70°C or higher.

[0127] Similarly, from the viewpoint of more reliably preventing deterioration or deactivation of the GHLC film or the like, the pressure during the above lamination is preferably 1.2 MPa or lower, and more preferably 0.8 MPa or lower. The lower limit value of the pressure during lamination is not particularly limited, but for example, when performing the above lamination under pressure such as in an autoclave, it is preferably 0.05 MPa or higher, and more preferably 0.1 MPa or higher.

[0128] The time for performing the lamination at the above temperature and / or pressure is not particularly limited, but for example, 1 to 120 minutes is preferable, and 5 to 60 minutes is more preferable.

[0129] In the above manufacturing method, as described above, it is preferable to perform preliminary adhesion (also referred to as temporary pressure bonding or preliminary lamination) before the above lamination. Thereby, it is possible to sufficiently suppress a decrease in transmittance and a decrease in adhesive strength that may occur in the autoclave process under low-temperature conditions.

[0130] From the viewpoint of further preventing deterioration or deactivation of the GHLC film or the like, it is preferable to perform the above preliminary adhesion under low-temperature conditions, and it is more preferable to perform the above preliminary adhesion under low-temperature and low-pressure conditions. For example, the temperature at the time of performing preliminary adhesion is preferably 110 ° C or lower, and more preferably 100 ° C or lower. Further, from the viewpoint of further preventing the generation and foaming of residual air, the temperature at the time of performing preliminary adhesion is preferably 60 ° C or higher, and more preferably 70 ° C or higher. The pressure at the time of performing preliminary adhesion is preferably 0.6 MPa or lower. Further, when performing preliminary adhesion under a negative pressure as in the case of using a vacuum back, the pressure at the time of performing preliminary adhesion is preferably 0.3 MPa or lower, more preferably 0.095 MPa or lower, and still more preferably 0.09 MPa or lower. The pressure at the time of performing preliminary adhesion under pressure is also preferably 0.01 MPa or higher, and more preferably 0.05 MPa or higher.

[0131] The time for performing preliminary adhesion at the above temperature and / or pressure is not particularly limited, but for example, 0 to 60 minutes is preferable, and 0 to 30 minutes is more preferable.

[0132] 〔Use〕 The laminated glass structure of the present disclosure can be used for various applications. For example, the laminated glass structure of the present disclosure can be used for vehicles such as automobiles and trains, various vehicles such as ships and airplanes, various buildings such as buildings, condominiums, single-family houses, halls, and gymnasiums, machine tools such as cutting and grinding machines, and construction machines such as excavators and cranes. It is used for window glass and partitions inside various vehicles and various buildings. Among them, the laminated glass structure is preferably used for vehicle applications such as automobiles and trains or building applications. Thus, both the laminated glass for vehicles and the laminated glass for buildings composed of the laminated glass structure of the present disclosure are those found by the present inventors. The laminated glass structure is particularly preferably used for window glass for vehicles or BIPV, and particularly preferably used for window glass for vehicles. The window glass for vehicles is preferably a front glass, side glass, rear glass, or roof glass of an automobile or a train.

[0133] The laminated glass structure of the present disclosure is also preferably used for various display applications. For example, window glass, partitions, etc. using the laminated glass structure may be used as a display. In addition, the laminated glass structure of the present disclosure can also be used as a cover glass for various displays. For example, the laminated glass structure may be applied to an in-vehicle display or the like.

Examples

[0134] The present disclosure will be described in more detail by way of examples and the like, but the present disclosure is not limited by these examples in any way. Unless otherwise specified, "parts" represents "parts by mass", and "%" represents "% by mass". The weight average molecular weight of the resin, the Tg of the film, and the creep compliance at 90°C per layer of the film were determined according to the methods described above.

[0135] <Materials, etc.> Each material or member used in the preparation examples and the like is as follows. (1) Glass plate Glass plate: Manufactured by Misato Glass Co., Ltd., trade name "float plate glass", size 30 cm × 30 cm × 3 mm

[0136] (2) GHLC film As one of the GHLC films, a GHLC film with a thickness of 0.4 mm was used. The GHLC film has a structure in which a PET substrate, a transparent electrode layer, an LC layer, a transparent electrode layer, and a PET substrate are laminated.

[0137] (3) Thermoplastic resin Preparation Example A1 (Resin 1) Into a reactor equipped with a stirring device, 1800 ml of ion-exchanged water, 150 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%), and 50 g of polyvinyl alcohol B (average degree of polymerization 800, saponification degree 99 mol%) were added, and heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Next, this solution was cooled and adjusted to a temperature of 40 °C. Then, 30% hydrochloric acid was added as a catalyst so that the hydrochloric acid concentration became 0.9% by mass. After adjusting the temperature to 20 °C, n-butylaldehyde was added with stirring so that it became 15 mol%. Then, the solution was adjusted to 13 °C, and when n-butylaldehyde was added so that it became 54.7 mol%, white particulate polyvinyl butyral resin precipitated. 20 minutes after the second addition of n-butylaldehyde, 30% hydrochloric acid was added so that the hydrochloric acid concentration became 1.1% by mass, and then the temperature was raised to 48 °C and aged at a aging temperature of 48 °C for 2 hours. Next, the solution was cooled, neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 1 (polyvinyl butyral resin, hydroxyl group amount 30.9 mol%, acetalization degree 68.1 mol%, acetylation degree 0.99 mol%, weight average molecular weight 245000).

[0138] Preparation Example A2 (Resin 2) Into a reactor equipped with a stirring device, 1800 ml of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) were added, and the mixture was heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Next, 30% hydrochloric acid was added to this solution as a catalyst so that the hydrochloric acid concentration became 0.2% by mass. After adjusting the temperature to 15 °C, n-butylaldehyde was added while stirring so that the amount became 10 mol%. Thereafter, when n-butylaldehyde was added so that the amount became 60 mol%, white particulate polyvinyl butyral resin was precipitated. Ten minutes after the precipitation, 30% hydrochloric acid was added so that the hydrochloric acid concentration became 1.8% by mass, and then the temperature was raised to 53 °C and aged at a ripening temperature of 53 °C for 2 hours. Next, the solution was cooled, neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 2 (polyvinyl butyral resin, hydroxyl group amount 31.5 mol%, acetalization degree 67.8 mol%, acetylation degree 0.7 mol%, weight average molecular weight 267000).

[0139] Adjustment Example A3 (Resin 3) Instead of aging Resin 2 at a ripening temperature of 53 °C for 2 hours, it was aged at a ripening temperature of 63 °C for 2 hours. Otherwise, in the same manner as in Preparation Example A2 (Resin 2), Resin 3 (polyvinyl butyral resin, hydroxyl group amount 30.1 mol%, acetalization degree 69.2 mol%, acetylation degree 0.67 mol%, weight average molecular weight 262000) was obtained.

[0140] (4) Plasticizer 3GO: Triethylene glycol-bis-(2-ethylhexanoate), manufactured by Sekisui Chemical Co., Ltd., molecular weight 402

[0141] (5) Intermediate film Preparation Example B1 (Film 1) To 100 parts of Resin 1, 40 parts of a plasticizer (3GO) was mixed to obtain a resin composition. The obtained resin composition was fed to a twin-screw extruder to produce Film 1 having a film thickness of 760 μm. For the obtained Film 1, Tg and the creep compliance J(t) at 90 °C per layer were measured. The results are shown in Table 1.

[0142] Adjustment Example B2 (Film 2) A film - like Film 2 with a thickness of 760 μm was prepared in the same manner as Preparation Example B1, except that Resin 2 was used instead of Resin 1. For the obtained Film 2, Tg and the creep compliance J(t) at 90°C were measured. The results are shown in Table 1.

[0143] Preparation Example B3 (Film 3) A film - like Film 3 with a thickness of 760 μm was prepared in the same manner as Preparation Example B1, except that Resin 3 was used instead of Resin 1. For the obtained Film 3, Tg and the creep compliance J(t) at 90°C were measured. The results are shown in Table 1.

[0144]

Table 1

[0145] <Example 1> Two glass plates, two Films 1, and a GHLC film were prepared. One Film 1, the GHLC film, and the other Film 1 were stacked in this order on one glass plate, and then the other glass plate was stacked on top of them to obtain Laminate 1. As shown in FIGS. 2 and 3, the glass plates and Film 1 each had a planar size of 300 mm × 300 mm, the GHLC film had a planar size of 200 mm × 200 mm, and they were arranged such that the centers of the glass plates, Film 1, and GHLC film overlapped in plan view. FIG. 2 is a schematic view of the layer structure of Laminate 1 viewed from the side, and FIG. 3 is a plan schematic view of Laminate 1.

[0146] The obtained Laminate 1 was placed in a rubber bag which was a vacuum bag, and degassed at a vacuum degree of 0.09 MPa for 5 minutes. Then, while still degassed, Laminate 1 was heated to 75°C at a heating rate of 2°C / min and then cooled to 30°C. Then, the pressure was returned to normal pressure. After that, Laminate 1 was held in an autoclave at 100°C and 0.3 MPa for 20 minutes, and after cooling, the pressure was returned to normal pressure.

[0147] <Example 2> A combined glass structure 2 was obtained in the same manner as in Example 1, except that film 2 was used on each side instead of film 1 disposed on both sides of the GHLC film.

[0148] <Comparative Example 1> A combined glass structure C1 was obtained in the same manner as in Example 1, except that film 3 was used on each side instead of film 1 disposed on both sides of the GHLC film.

[0149] <Evaluation Test> Using each of the combined glass structures obtained in the examples or comparative examples, the following evaluation tests were conducted. The results are shown in Table 2. Table 2 also shows the types of the intermediate films and functional layers constituting each combined glass structure (the glass plates are omitted).

[0150] (1) Color unevenness The laminate after autoclaving was placed on a light table, and it was checked whether the liquid crystal of the GHLC was partially shaded. Then, it was judged according to the following criteria. No shading at all: ◎ Shading at 1 to 2 places: ○ Shading at 3 or more places: ×

[0151] (2) Appearance evaluation After storing the above laminate at normal temperature and pressure for one week, it was checked whether bubbles entered the liquid crystal and made it transparent without applying voltage. Among them, the number of bubbles of 1 mm or more was counted. Then, it was judged according to the following criteria. No bubbles at all: ◎ 1 to 2 bubbles: ○ 3 or more bubbles: ×

[0152]

Table 2

Explanation of symbols

[0153] 10: Combined glass structure G1, G2, G: Glass plate F1, F2, F: Intermediate film Z: GHLC film

Claims

1. A first glass plate, a first intermediate film, a guest-host liquid crystal (GHLC) film, a second intermediate film, and a second glass plate, provided in this order, The first intermediate film contains a polyvinyl acetal resin, and the creep compliance at 90 °C per layer is 6.0×10 －５ Pa －１ or more and 1.0×10−3 Pa−1 or less, wherein the amount of hydroxyl groups in the polyvinyl acetal resin is 30.9 mol% or more A laminated glass structure characterized by this.

2. A first glass plate, a first intermediate film, a guest-host liquid crystal (GHLC) film, a second intermediate film, and a second glass plate, provided in this order, wherein the first intermediate film contains a polyvinyl acetal resin, and the creep compliance at 90°C per layer is 8.0×10−5 Pa−1 or more and 1.0×10−3 Pa−1 or less, and the polyvinyl acetal resin has a weight average molecular weight of 245,000 or more A laminated glass structure characterized by this.

3. The creep compliance at 90°C per layer is 8.0×10−5 Pa−1 or more An intermediate film for laminated glass according to Claim 1, characterized by this.

4. The polyvinyl acetal resin has a weight average molecular weight of 220,000 to 310,000 A laminated glass structure according to Claim 1, characterized by this.

5. The polyvinyl acetal resin has a weight average molecular weight of 310,000 or less A laminated glass structure according to Claim 2, characterized by this.

6. The first intermediate film further contains a plasticizer A laminated glass structure according to Claim 1, characterized by this.

7. The plasticizer is at least one selected from the group consisting of triethylene glycol-di-2-ethylhexanoate, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, and derivatives in which a part of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups A laminated glass structure according to Claim 6, characterized by this.

8. A laminated film comprising the first intermediate film, the GHLC film, and the second intermediate film for the laminated glass structure according to any one of Claims 1 to 7

9. A film comprising the first intermediate film for the laminated glass structure according to any one of Claims 1 to 7 Characterized by this.

10. Manufactured without using a gap filler A laminated glass structure according to any one of Claims 1 to 7, characterized by this. ​

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