Laminated glass structure, film, and laminated film

Abstract

The present disclosure provides a laminated glass structure which can exhibit a function derived from a functional layer, in which occurrence of deflection or distortion is sufficiently suppressed, and which has good appearance and high safety. The present disclosure also provides a laminated film composed of the first interlayer film, the functional layer, and the second interlayer film included in such a laminated glass structure, and a film composed of the first interlayer film.SOLUTION: A laminated glass structure comprising a first glass plate, a first interlayer film, a functional layer, a second interlayer film, and a second glass plate in this order, wherein the first interlayer film has a compliance per layer at 90 °C. of 6.0 * 10 - 5Pa - 1 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to laminated glass constructs, films and laminated films. [Background technology]

[0002] Conventionally, laminated glass structures have been widely known, in which two glass sheets are integrated by interposing an interlayer film between them. Laminated glass structures are safe because they rarely scatter glass fragments even when broken by external impact, and are therefore widely used in vehicles such as automobiles, aircraft, ships, buildings, etc.

[0003] In recent years, laminated glass structures have been required to have various functions, for example, a functional layer such as a light control film disposed between two glass sheets. Patent Document 1 discloses laminated glass having an interlayer film and a light control element encapsulated in the interlayer film between two glass sheets. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 153998 Summary of the Invention [Problem to be solved by the invention]

[0005] Laminated glass structures are generally manufactured by placing an interlayer between two glass sheets, followed by a preliminary degassing process, followed by an autoclave process in which the glass sheets and the interlayer are pressure-bonded under high-temperature and high-pressure conditions, such as a temperature of approximately 130 to 140°C and a pressure of approximately 1.3 MPa. However, when a functional layer such as a light control film is further placed between the two glass sheets, the functional layer is likely to have complex steps (thickness differences) due to the inclusion of electronic wiring, occlusion printed areas, etc., and pressure unevenness during pressure bonding. As a result, air remains or bubbles form between the interlayer and the glass sheets or functional layer during pressure bonding, resulting in insufficient transparency in the obtained laminated glass structure, distortion or wrinkles in the functional layer, and distortion or warping of the obtained laminated glass structure, resulting in an unsatisfactory appearance.

[0006] In laminated glass structures including a functional layer such as a light control film, a frame-shaped intermediate layer (also referred to as a gap filler) is placed around the periphery of the functional layer for the purpose of protecting the edges of the functional layer from the external environment, and this is sandwiched between a pair of intermediate layers, which is then further sandwiched between a pair of glass plates (see, for example, Patent Document 1, etc.). If a laminated glass structure including a functional layer is manufactured without using a gap filler, in order to improve work efficiency, air may remain or bubbles may form, which may result in an unsatisfactory appearance in the laminated glass structure and may also result in lower impact resistance compared to when a gap filler is used.

[0007] The present disclosure has been made in view of the above-described current situation, and aims to provide a laminated glass structure that can exhibit the functions inherent in the functional layer, is sufficiently suppressed in terms of the occurrence of deflection and distortion, has a good appearance, and is highly safe. Another aim of the present disclosure is to provide a laminated film that is included in such a laminated glass structure and that is composed of a first interlayer film, a functional layer, and a second interlayer film, and a film composed of the first interlayer film. [Means for solving the problem]

[0008] The present inventors have conducted extensive research into laminated glass structures including a functional layer such as a light control film, and have found that in a laminated glass structure including a first glass sheet, a first interlayer film, a functional layer, a second interlayer film, and a second glass sheet in this order, if at least one of the interlayer films has a predetermined creep characteristic, residual air and foaming during pressure bonding can be suppressed, even without the use of a gap filler, resulting in a laminated glass structure with a good appearance. Such a laminated glass structure can preferably exhibit the effects of the functional layer, and can also exhibit impact resistance comparable to that of a structure using a gap filler. Even if the glass structure is broken, scattering and penetration of glass fragments are suppressed, making it safe. Thus, the present inventors have completed the laminated glass structure and the like of the present disclosure. Specifically, the present disclosure relates to the following laminated glass structures and the like.

[0009] Disclosure 1 provides a glass sheet having a first glass plate, a first interlayer film, a functional layer, a second interlayer film, and a second glass plate in this order, wherein the first interlayer film has a creep compliance of 6.0 × 10 per layer at 90°C. -5 Pa -1 The laminated glass structure is as described above. Disclosure 2 discloses a method for manufacturing a laminated laminated laminated to a laminated sheet, the creep compliance of which is 8.0×10 at 90°C per layer. -5 Pa -1 Over 5.0 x 10 -4 Pa -1 The laminated glass structure of the present disclosure 1 is as follows. Disclosure 3 is the laminated glass structure of Disclosure 1 or 2, wherein the first interlayer film contains a thermoplastic resin. Disclosure 4 is the laminated glass structure according to any one of Disclosures 1 to 3, wherein the first interlayer film contains a polyvinyl acetal resin. Disclosure 5 is the laminated glass structure according to Disclosure 4, wherein the polyvinyl acetal resin has a weight-average molecular weight of 220,000 to 310,000. Disclosure 6 is the laminated glass structure according to any one of Disclosures 3 to 5, wherein the first interlayer film further contains a plasticizer. Disclosure 7 is the laminated glass structure according to Disclosure 6, 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 thereof in which some of the hydrogen atoms of their terminal hydroxyl groups have been substituted with alkyl groups. The present disclosure 8 is the laminated glass structure according to any one of the present disclosures 1 to 7, wherein the functional layer is at least one selected from the group consisting of a light control film and a display element film. Disclosure 9 is the laminated glass structure according to any one of Disclosures 1 to 8, wherein the functional layer is a light control film, and the light control film comprises at least one selected from the group consisting of a polymer dispersed liquid crystal (PDLC), a guest-host crystal (GHLC), a suspended particle device (SPD), an electrochemical device, and an electrophoretic film device. Disclosure 10 is a laminated film comprising the first interlayer film, the functional layer, and a second interlayer film, which is included in the laminated glass structure of any one of Disclosures 1 to 9. Disclosure 11 of the present invention is a film composed of the first interlayer film provided in the laminated glass structure of any one of Disclosures 1 to 9 of the present invention. Disclosure 12 is the laminated glass structure of any one of Disclosures 1 to 9, produced without using a gap filler. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a laminated glass structure that can exhibit the functions inherent to the functional layer, is sufficiently suppressed in occurrence of deflection or distortion, has a good appearance, and is highly safe. Furthermore, according to the present disclosure, it is also possible to provide a laminated film comprising a first interlayer film, a functional layer, and a second interlayer film, and a film comprising the first interlayer film, which are included in such a laminated glass structure. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of a layer structure of a laminated glass structure. [Figure 2] 1 is a schematic side view of the layer structure of a laminate 1 in Example 1. FIG. [Figure 3] 1 is a schematic plan view of a laminate 1 in Example 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The laminated glass structure of the present disclosure comprises, in this order, a first glass sheet, a first interlayer film, a functional layer, a second interlayer film, and a second glass sheet. The laminated glass structure may further comprise one or more optional layers between the respective layers, or may comprise two or more functional layers as described below.

[0013] [Glass plate] The laminated glass structure has a first glass plate and a second glass plate. Each glass plate may be, for example, inorganic glass or organic glass, but is preferably inorganic glass. The first glass plate and the second glass plate may be made of the same material or 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.

[0014] The inorganic glass is not particularly limited, but examples thereof include clear glass, float glass, tempered glass, colored glass, polished glass, patterned glass, wired glass, striped glass, ultraviolet absorbing glass, infrared reflecting glass, infrared absorbing glass, and green glass.

[0015] As the organic glass, what is generally called resin glass is used, and examples thereof include various organic glass plates such as polycarbonate plate, (meth)acrylic plate such as polymethyl methacrylate plate, acrylonitrile styrene copolymer plate, acrylonitrile butadiene styrene copolymer plate, polyester plate such as polyethylene terephthalate plate, fluorine-based resin plate, polyvinyl chloride plate, chlorinated polyvinyl chloride plate, polypropylene plate, polystyrene plate, polysulfone plate, epoxy resin plate, phenolic resin plate, unsaturated polyester resin plate, polyimide resin plate, etc. The resin plate may be subjected to a surface treatment or the like as appropriate.

[0016] The thickness of each glass plate is not particularly limited, but is preferably about 0.1 to 15 mm, more preferably 0.5 to 5 mm, for example. The thickness of each glass plate may be the same as or different from that of the first glass plate and the second glass plate.

[0017] 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 and second glass plates, imparting various functions to the glass plate. The other members are preferably members constituting electronic devices or optical components, and more preferably members constituting display devices. Examples of display devices include liquid crystal display devices, organic EL display devices, LED display devices, and segment display devices, among which liquid crystal display devices are preferred. Examples of display devices include display panels using a glass plate as a substrate on which a display layer such as a liquid crystal layer or an organic EL layer, and light-emitting elements, etc. are provided. The glass plate as a substrate may be used as the first glass plate and / or the second glass plate. Each glass plate may also be laminated with various functional layers, such as a functional film (described below); a conductive layer constituting an electrode, sensor, etc.; an antireflection layer; or a hard coat layer.

[0018] [Interlayer] The laminated glass structure has at least a pair of interlayer films arranged to sandwich a functional layer. One of the pair of interlayer films is referred to as a first interlayer film, and the other is referred to as a second interlayer film. The first interlayer film and the second interlayer film may have the same configuration or may be different from each other.

[0019] The first interlayer film and the second interlayer film may each be a single-layer film having a single-layer structure, or a multilayer film having a multilayer structure. When the first interlayer film and / or the second interlayer film has multiple layers, the multiple layers may have the same structure or different structures. For example, the types and contents of the constituent materials (e.g., thermoplastic resins) of the multiple layers may be the same or different. When the first interlayer film has multiple layers, the number of layers is not particularly limited, but may be, for example, two or three. When the second interlayer film has multiple layers, the number of layers is not particularly limited, but may be, for example, two or three.

[0020] The first interlayer has a creep compliance of 6.0 x 10 per layer at 90°C. -5 Pa -1 That's all. Such an interlayer film has high fluidity under lamination conditions, so a laminated glass structure can be suitably obtained even without disposing a gap filler around the functional layer. That is, when the interlayer film and the functional layer are disposed between a pair of glass plates and pressure-bonded, peeling at the layer interface and the generation of residual air or bubbles are sufficiently suppressed. Furthermore, even if this pressure-bonding is performed under low-temperature conditions, residual air or bubbles are sufficiently suppressed. Furthermore, even if this pressure-bonding is performed under low-pressure conditions, residual air or bubbles are sufficiently suppressed. Therefore, the laminated glass structure of the present disclosure has excellent transparency and a good appearance. The creep compliance is 8.0 × 10 -5 Pa -1 It is preferable that the value is equal to or greater than 1.0×10 -4 Pa -1 More preferably, it is 1.3×10 or more. -4 Pa -1 The upper limit of the creep compliance is more preferably 1.0×10-3 Pa -1 Preferably, it is 7.0 x 10 or less. -4 Pa -1 Less than 5.0 x 10 is preferable. -4 Pa -1 It is more preferable that the creep compliance is 6.0×10 or less. -5 Pa -1 Over 1.0 x 10 -3 Pa -1 Preferably, it is 6.0 x 10 or less. -5 Pa -1 Over 7.0 x 10 -4 Pa -1 More preferably, it is 6.0×10 or less. -5 Pa -1 Over 5.0 x 10 -4 Pa -1 More preferably, it is 8.0×10 or less. -5 Pa -1 Over 5.0 x 10 -4 Pa -1 More preferably, it is 1.0×10 or less. -4 Pa -1 Over 5.0 x 10 -4 Pa -1 It is particularly preferable that the value is 1.3×10 or less. -4 Pa -1 Over 5.0 x 10 -4 Pa -1 Most preferably, the following:

[0021] The creep compliance at 90° C. per layer is determined as follows. <Method for measuring creep compliance> The measurement device used was the Anton Paar MCR702e MultiDrive dynamic viscoelasticity measurement system (purchased in 2023). Using this measurement device, a circular sample made from one layer of interlayer film, 8 mm in diameter and 0.76 mm thick, was subjected to a shear stress of 400 Pa for 15 minutes at a measurement temperature of 90°C to obtain the creep compliance J(t). The value of the obtained creep compliance J(t) after 10 minutes was taken as the "creep compliance per layer at 90°C" value.

[0022] Here, if the thickness of the sample (interlayer film) to be measured is less than 0.76 mm, several samples may be stacked and press-molded or the like to make the samples uniform in thickness, or if the physical properties of the sample change due to heat pressing, the sample may be measured at its original thickness without being pressed. Furthermore, if the sample thickness is thicker than 0.76 mm, the thickness may be made uniform by press-molding or the like, or the sample may be measured at its original thickness. From the viewpoint of measurement accuracy, the measured sample thickness is preferably 0.3 mm or more, and preferably 3 mm or less.

[0023] When setting the sample in the measurement device, the gap is set at room temperature to a pressure of 5 to 10 N to ensure sufficient compression between the sample and the jig, and then the sample is heated to 140°C with the gap fixed. Two minutes after reaching 140°C, the temperature begins to drop to the measurement temperature, and after reaching the measurement temperature, the temperature is held for two minutes before creep compliance measurement begins. Stainless steel parallel plates with a diameter of 8 mm are used as the measurement jig.

[0024] In the laminated glass structure of the present disclosure, it is sufficient that at least one (first interlayer film) of a pair of interlayer films arranged to sandwich the functional layer satisfies the above creep compliance value. For example, if the first interlayer film is a multilayer film, it is sufficient that at least one layer thereof satisfies the above creep compliance value. However, considering, for example, the adhesion between the glass sheet and the first interlayer film, it is preferable that the layer constituting the first interlayer film adjacent to the glass sheet satisfies the above creep compliance value. Furthermore, considering the adhesion between the first interlayer film and the functional layer, it is preferable that the layer constituting the first interlayer film adjacent to the functional layer satisfies the above creep compliance value, and it is more preferable that all layers satisfy the above creep compliance value.

[0025] From a similar viewpoint, it is preferable that the second interlayer film also satisfies the above creep compliance value. When the second interlayer film is a multilayer film, it is sufficient that at least one layer thereof satisfies the above creep compliance value, but, for example, in consideration of the adhesion between the glass plate and the second interlayer film, it is preferable that the layer constituting the second interlayer film that is adjacent to the glass plate satisfies the above creep compliance value, and in consideration of the adhesion between the second interlayer film and the functional layer, it is preferable that the layer constituting the second interlayer film that is adjacent to the functional layer satisfies the above creep compliance value, and it is more preferable that all layers satisfy the above creep compliance value.

[0026] The first interlayer film and / or the second interlayer film preferably have a glass transition temperature (Tg) of -10°C or higher. When Tg is within this range, penetration resistance and impact resistance are further improved. Tg is more preferably 0°C or higher, even more preferably 10°C or higher, and particularly preferably 15°C or higher. Tg is also preferably 50°C or lower. When Tg is within this range, adhesion to glass plates and the like is more likely to be improved. Tg is more preferably 40°C or lower, and even more preferably 30°C or lower.

[0027] The Tg of the interlayer film can be determined by measuring viscoelasticity. Specifically, it can be determined, for example, as follows. <Method for Measuring Tg> Store the test piece to be measured in an environment of room temperature 23 ± 2°C and humidity 25 ± 5% for 12 hours. Then, use a viscoelasticity measuring device "ARES-G2" manufactured by TA Instruments to measure the viscoelasticity. Use a parallel plate with a diameter of 8 mm as the jig, and measure 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 defined as the glass transition temperature Tg (°C).

[0028] (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 above 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 above creep compliance value is the above resin layer. In addition, 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.

[0029] Examples of thermoplastic resins include (meth)acrylic resins, polyvinyl acetal resins, polyvinyl alcohol resins, polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymer (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and styrene-butadiene copolymer resins. Among these, from the viewpoint of achieving both moist heat resistance and impact resistance, the thermoplastic resin is preferably polyvinyl acetal resins, polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymer (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and / or styrene-butadiene copolymer resins. Among these, the thermoplastic resin is more preferably polyvinyl acetal resins.

[0030] As described above, the resin layer preferably contains a polyvinyl acetal resin. That is, the first interlayer film preferably contains a polyvinyl acetal resin. The second interlayer film also preferably contains a polyvinyl acetal resin. By providing an interlayer film containing a polyvinyl acetal resin, the laminated glass structure has better impact resistance and the interlayer film has better adhesion to various adherends (e.g., functional layers, glass plates, etc.). The polyvinyl acetal resin will be described in detail below.

[0031] Polyvinyl acetal resins are obtained by acetalizing polyvinyl alcohol with an aldehyde. Each of the raw materials for the polyvinyl acetal resins may be used alone or in combination of two or more.

[0032] The aldehyde is not particularly limited, but for example, an aldehyde having 1 to 10 carbon atoms is preferably used. The aldehyde having 1 to 10 carbon atoms is not particularly limited, and examples thereof include n-butylaldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, formaldehyde, acetaldehyde, and benzaldehyde. Among these, the aldehyde is preferably n-butylaldehyde, n-hexylaldehyde, or n-valeraldehyde, and more preferably n-butylaldehyde. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin.

[0033] Polyvinyl alcohol can be obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate, etc. The degree of saponification of polyvinyl alcohol is generally 70 to 99.9 mol %.

[0034] The average polymerization degree of the polyvinyl alcohol is preferably 1000 to 3000. By using such a polyvinyl alcohol, the polyvinyl acetal resin tends to have a preferred weight-average molecular weight, which will be described later. The average polymerization degree of the polyvinyl alcohol is more preferably 1100 to 2500, further preferably 1200 to 2000, and particularly preferably 1300 to 1700.

[0035] Two or more types of polyvinyl alcohols having different average degrees of polymerization may be used as the polyvinyl alcohol. In this case, it is preferable to produce the polyvinyl acetal resin using a mixture of two or more types of polyvinyl alcohols as a raw material.

[0036] When two or more polyvinyl alcohols are used, it is preferable to use, for example, 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 even more preferably 1600 to 2000. The average degree of polymerization of the second polyvinyl alcohol is preferably 200 to 1200, more preferably 300 to 900, and even more preferably 400 to 850.

[0037] When the first polyvinyl alcohol and the second polyvinyl alcohol are used in combination, their blending ratio is not particularly limited. For example, the blending amount of the second polyvinyl alcohol is preferably 1 to 50 mass%, more preferably 3 to 40 mass%, even more preferably 5 to 35 mass%, and particularly preferably 10 to 30 mass%, relative to 100 mass% of the total amount of the first polyvinyl alcohol and the second polyvinyl alcohol.

[0038] The average degree of polymerization of polyvinyl alcohol is determined by a method conforming to JIS K6726 (1994) "Testing Method for Polyvinyl Alcohol." When two or more types of polyvinyl alcohol are used as raw materials, the average degree of polymerization of polyvinyl alcohol can be estimated by calculation from the average degree of polymerization of each polyvinyl alcohol.

[0039] The polyvinyl acetal resin preferably has a weight-average molecular weight of 100,000 to 300,000. This further improves the adhesion of the interlayer film to various substrates and the penetration resistance of the laminated glass structure. Furthermore, using a polyvinyl acetal resin having a weight-average molecular weight within the above range makes it easier to adjust the creep compliance per interlayer film layer within the above range. The lower limit of the weight-average molecular weight of the polyvinyl acetal resin is more preferably 180,000 or more, even 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, even more preferably 260,000 or less, and particularly preferably 250,000 or less. The weight average molecular weight of the polyvinyl acetal resin is more preferably in the range of 180,000 to 280,000, further preferably 210,000 to 260,000, and particularly preferably 220,000 to 250,000.

[0040] The weight average molecular weight of the polyvinyl acetal resin can be determined, for example, by the following measurement method using gel permeation chromatography. <Method for measuring molecular weight> Polyvinyl acetal resin is dissolved in N-methyl-2-pyrrolidone solution containing lithium bromide to a concentration of 10 mM to obtain a solution with a polyvinyl acetal resin concentration of 0.05% by mass. The resulting solution is filtered using a syringe filter (Millex-LH 0.45 μm, manufactured by Merck) and then the molecular weight is measured using gel permeation chromatography (e2690, manufactured by Waters). The weight-average molecular weight (Mw) is calculated using a molecular weight calibration curve prepared using monodisperse polystyrene standard samples. The column used is Shodex GPC KF-806L (Showa Denko KK), and the eluent used is an N-methyl-2-pyrrolidone solution containing lithium bromide added to a concentration of 10 mM.

[0041] The hydroxyl group content of the polyvinyl acetal resin is preferably 15 mol% or more. This tends to improve the adhesion of the interlayer film to various substrates, and the resulting laminated glass structure has excellent penetration resistance and other properties. The hydroxyl group content of the polyvinyl acetal resin is preferably 38 mol% or less. This improves the flexibility of the interlayer film and prevents the resulting laminated glass structure from becoming too hard. Furthermore, when the hydroxyl group content of the polyvinyl acetal resin is within the above range, the generation of bubbles during use in a high-temperature environment is sufficiently suppressed, further improving the high-temperature heat resistance of the interlayer film. The lower limit of the hydroxyl group content is more preferably 20 mol% or more, and even more preferably 25 mol% or more. The upper limit of the hydroxyl group content is more preferably 35% or less, and even more preferably 33 mol% or less.

[0042] When a polyvinyl butyral resin is used 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 even more preferably 25 mol% or more, and 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 even more preferably 33 mol% or less.

[0043] The amount of hydroxyl groups in a polyvinyl acetal resin is the molar fraction calculated by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain, expressed as a percentage. The amount of ethylene groups to which hydroxyl groups are bonded can be measured, for example, in accordance with JIS K6728 (1977) "Testing Methods for Polyvinyl Butyral."

[0044] The degree of acetalization of the polyvinyl acetal resin is preferably 47 mol% or more, more preferably 55 mol% or more, and even 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 even more preferably 75 mol% or less. Note that when the acetal group is a butyral group and the polyvinyl acetal resin is a polyvinyl butyral resin, the degree of acetalization refers to the degree of butyralization.

[0045] The degree of acetalization of a polyvinyl acetal resin is a molar fraction calculated by subtracting the number of ethylene groups having hydroxyl groups and the number of ethylene groups having acetyl groups from the total number of ethylene groups in the main chain, and dividing the result by the total number of ethylene groups in the main chain, and the percentage of the molar fraction is expressed as a percentage. The degree of acetalization can be calculated, for example, from the results of measurements performed according to JIS K6728 (1977) "Testing Methods for Polyvinyl Butyral."

[0046] The degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less. This improves the moisture resistance of the interlayer film. The upper limit of the degree of acetylation is more preferably 20 mol% or less, even 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, more preferably 0.1 mol% or more.

[0047] The degree of acetylation of a polyvinyl acetal resin is the molar fraction calculated by dividing the amount of ethylene groups bonded to acetyl groups by the total amount of ethylene groups in the main chain, and is expressed as a percentage. The amount of ethylene groups bonded to acetyl groups can be measured, for example, in accordance with JIS K6728 (1977) "Testing Methods for Polyvinyl Butyral."

[0048] The polyvinyl acetal resin is preferably an unmodified polyvinyl acetal resin, but may also be a modified polyvinyl acetal resin. A modified polyvinyl acetal resin is one having a structure (modifying group) other than an acetal group, a hydroxyl group, and an acetyl group, and preferably has a modifying group on its side chain. Examples of the modifying group include those having a polyalkylene oxide structure on the side chain, and those having an alkyl group (e.g., having about 2 to 30 carbon atoms) other than an acetal group or an acetyl group on the side chain. The modification amount is not particularly limited, but is, for example, about 0.1 mol % to 10 mol %. The modification amount refers to the ratio of functional groups to all vinyl monomer units constituting the polyvinyl acetal resin.

[0049] When the first interlayer film and / or the second interlayer film contains a polyvinyl acetal resin, the interlayer film may further contain a thermoplastic resin other than a polyvinyl acetal resin. Examples of thermoplastic resins other than a polyvinyl acetal resin are as described above. However, it is preferable that the main component of the resin constituting the interlayer film is a polyvinyl acetal resin. Specifically, out of the total 100% by mass of the resin components constituting the resin layers constituting each interlayer film (or each resin layer if each interlayer film has multiple resin layers), the polyvinyl acetal resin preferably accounts for 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and most preferably 100% by mass. In other words, it is most preferable that the resin constituting each interlayer film is only a polyvinyl acetal resin.

[0050] The polyvinyl acetal resin is preferably produced by a production method including, for example, a mixing step of mixing polyvinyl alcohol with an aldehyde and a aging step of aging the mixture obtained in the mixing step. The acetalization of polyvinyl alcohol proceeds through the mixing step and the aging step, thereby producing the polyvinyl acetal resin. Note that, for example, 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.

[0051] In the mixing step, polyvinyl alcohol and aldehyde may be mixed according to a conventional method. In addition to polyvinyl alcohol and aldehyde, a catalyst such as an acid catalyst may be added to promote the acetalization reaction. For example, the aldehyde may be added to a mixture of polyvinyl alcohol and an acid catalyst at a low temperature of about 0 to 40°C. When two or more polyvinyl alcohols are used in combination (for example, when two or more polyvinyl alcohols having different molecular weights are used), the two or more polyvinyl alcohols may be mixed with the aldehyde.

[0052] In the aging step, for example, a catalyst such as an acid catalyst is added to the mixture (reaction mixture) obtained in the mixing step, followed by heating to an aging temperature and maintaining the mixture at the aging temperature for a certain period of time. After maintaining the reaction mixture at the aging temperature for a certain period of time, the reaction mixture may be appropriately cooled or neutralized, and then washed with water, dried, or the like, as necessary.

[0053] Examples of acid catalysts that can be added in the mixing step and the aging step include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, boric acid, sulfuric acid, etc. In the aging step, the concentration of the acid catalyst is preferably adjusted to, for example, about 0.5% by mass to about 5% by mass, and more preferably about 1% by mass to about 2.5% by mass.

[0054] The aging temperature in the aging step may be relatively low, for example, preferably 40°C to 60°C, more preferably 35°C to 60°C, and even more preferably 40°C to 57°C. The time for which the aging temperature is maintained (aging time) may be longer than a certain period, for example, preferably 75 minutes to 180 minutes, more preferably 90 minutes to 150 minutes, and even more preferably 100 minutes to 140 minutes. It is presumed that when the aging temperature and aging time are within the above ranges, hydroxyl groups in the polyvinyl acetal resin are more likely to be uniformly distributed throughout the molecule, which is thought to result in fewer low-molecular-weight components and a narrower molecular weight distribution.

[0055] (plasticizer) When the first interlayer film and / or the second interlayer film contains a thermoplastic resin, the interlayer film preferably further contains a plasticizer. That is, the resin layer preferably further contains a plasticizer. When the interlayer film further contains a plasticizer in addition to a thermoplastic resin, the interlayer film becomes more flexible, thereby improving the adhesion of the interlayer film to various substrates and the penetration resistance of a laminated glass structure obtained using the interlayer film. Furthermore, adjusting the type and content of the plasticizer makes it easier to adjust the creep compliance per interlayer film layer within a predetermined range.

[0056] Preferred examples of the plasticizer include organic ester plasticizers, organic phosphate ester plasticizers such as organic phosphate ester plasticizers and organic phosphite ester plasticizers, organic ether plasticizers such as polyalkylene glycol plasticizers, and alcohol plasticizers. Among these, the plasticizer is preferably an organic ester plasticizer and / or an organic ether plasticizer.

[0057] Preferred examples of the organic ester plasticizer include monobasic organic acid esters and polybasic organic acid esters.

[0058] Examples of monobasic organic acid esters include esters of glycols and monobasic organic acids. The glycol is preferably a polyalkylene glycol or a monoalkylene glycol. The number of carbon atoms in each alkylene unit constituting the polyalkylene glycol or monoalkylene glycol is preferably 2 to 4, more preferably 2 or 3. In addition, the number of repeating alkylene units in the polyalkylene glycol is preferably 2 to 10, more preferably 2 to 4. Specific examples of glycols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and butylene glycol. In addition, examples of monobasic organic acids include organic acids having 3 to 10 carbon atoms, such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, n-nonylic acid, and decylic acid.

[0059] Specific examples of the monobasic organic acid ester include 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 Examples of the diethylene glycol di-2-ethyl butyrate include glycerol di-2-ethylpentanoate, tetraethylene glycol di-2-ethyl butyrate, diethylene glycol dicaprylate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethyl butyrate, ethylene glycol di-2-ethyl butyrate, 1,2-propylene glycol di-2-ethyl butyrate, 1,3-propylene glycol di-2-ethyl butyrate, 1,4-butylene glycol di-2-ethyl butyrate, and 1,2-butylene glycol di-2-ethyl butyrate.

[0060] Examples of polybasic organic acid esters include ester compounds of dibasic organic acids having 4 to 12 carbon atoms and alcohols having 4 to 10 carbon atoms. Examples of dibasic organic acids having 4 to 12 carbon atoms include adipic acid, sebacic acid, and azelaic acid. The alcohols having 4 to 10 carbon atoms may be linear, have a branched structure, or have a cyclic structure.

[0061] Specific examples of polybasic organic acid esters include dibutyl sebacate, dioctyl azelaate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl carbitol adipate, and mixed adipates. The polybasic organic acid ester may also be an oil-modified alkyd sebacate. Examples of mixed adipates include adipates 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.

[0062] The organic ester plasticizer is not limited to a complete ester of each of the above esters, but may also be a partial ester. For example, the organic ester plasticizer may be 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 triethylene glycol-mono-2-ethylhexanoate.

[0063] The organic ester plasticizer may also be a partial ester of a trivalent or higher alcohol such as glycerin with a monobasic organic acid. The number of carbon atoms in the monobasic organic acid is preferably 3 to 24, and more preferably 6 to 18. Specific examples include a mono- or diester of glycerin and stearic acid, and a mono- or diester of glycerin and 2-ethylhexyl acid.

[0064] Among the above-mentioned organic ester plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferably used.

[0065] Preferred examples of the organic phosphorus plasticizer include organic phosphate ester plasticizers, organic phosphite ester plasticizers, etc. Specific examples of the organic phosphorus plasticizer include phosphate esters such as tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

[0066] A preferred example of an organic ether-based plasticizer is a polyalkylene glycol-based plasticizer. Examples of polyalkylene glycol-based plasticizers include polyoxyalkylene compounds having a polyoxyalkylene structure, specifically polyhydric alcohol compounds such as glycol; ester compounds of glycol with a monobasic organic acid or a polybasic organic acid; and ether compounds of a monohydric or polyhydric alcohol with a polyoxyalkylene. Examples of glycols include polyoxyalkylene glycols and their derivatives, and examples of polyoxyalkylenes include polyoxyethylene, polyoxypropylene, polyoxybutylene, and random or block copolymers thereof. The polyoxyalkylene compound may be a polyhydric alcohol compound, an ester compound, an ether compound, or other compounds, as described above.

[0067] Examples of polyoxyalkylene compounds include polyoxyalkylene and its derivatives. More specifically, examples include polyoxyalkylene glycols composed of polyoxyalkylene, and ether compounds of polyoxyalkylene and polyhydric alcohols. All of these compounds may have hydroxyl groups at their terminals, or may be derivatives in which some or all of the hydrogen atoms at the terminal hydroxyl groups have been substituted with alkyl groups or acyl groups. The number of carbon atoms in the alkyl and acyl groups is not particularly limited, but may be about 1 to 8, preferably 1 to 4.

[0068] Examples of polyoxyalkylene glycols include polyoxyethylene polyoxypropylene glycols such as polyethylene glycol (polyoxyethylene glycol), polypropylene glycol (polyoxypropylene glycol), poly(ethylene oxide / propylene oxide) block copolymers and poly(ethylene oxide / propylene oxide) random copolymers, and polyoxybutylene glycols such as polytetramethylene glycol.

[0069] Examples of ether compounds of polyoxyalkylenes and polyhydric alcohols include ether compounds of polyoxyalkylenes with polyhydric alcohols such as glycerol, diglycerol, trimethylolpropane, erythritol, pentaerythritol, and bisphenol A, specifically polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, etc. Examples of derivatives in which some or all of the hydrogen atoms of terminal hydroxyl groups have been substituted with alkyl groups or acyl groups include the above-mentioned polyoxyalkylene glycols and derivatives in which some or all of the hydrogen atoms of terminal hydroxyl groups of ether compounds have been substituted with alkyl groups or acyl groups. Specific 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, and polyoxyethylene polyoxypropylene monobutyl ether.

[0070] Among the above-mentioned polyoxyalkylene compounds, compounds having a polyoxyethylene structure, a polyoxypropylene structure, or a polyoxyethylene polyoxypropylene structure are preferred, and among these, 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 thereof in which some of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups.

[0071] Preferred examples of the alcohol-based plasticizer include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, pentaerythritol, etc. Among these, trimethylolpropane is preferred.

[0072] 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 thereof in which some of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups, and 3GO is more preferred.

[0073] When the resin layer further contains a plasticizer, the content of the plasticizer (total amount when two or more types are contained) is preferably, for example, 10 parts by mass or more per 100 parts by mass of the thermoplastic resin contained in the resin layer (one layer). This makes the interlayer film moderately flexible, further improving the adhesion of the interlayer film to various substrates and the penetration resistance of the laminated glass structure. The content of the plasticizer per 100 parts by mass of the thermoplastic resin is more preferably 15 parts by mass or more, even more preferably 30 parts by mass or more, and particularly preferably 35 parts by mass or more. The content of the plasticizer is also preferably 100 parts by mass or less per 100 parts by mass of the thermoplastic resin. This sufficiently prevents the plasticizer from separating from the interlayer film. The content of the plasticizer per 100 parts by mass of the thermoplastic resin is more preferably 70 parts by mass or less, even 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.

[0074] (Other additives) The first interlayer film and / or the second interlayer film may also contain known additives that can be used in combination with thermoplastic resins. That is, for example, the resin layer may contain known additives. Examples of additives other than plasticizers include ultraviolet absorbers, heat shielding agents, colorants, infrared absorbers, antioxidants, light stabilizers, adhesion modifiers, fluorescent whitening agents, and crystal nucleating agents. Each of the additives may be used alone or in combination of two or more.

[0075] (ultraviolet absorber) When the interlayer film contains an ultraviolet absorber, deterioration of the functional layer due to ultraviolet rays is sufficiently suppressed. For example, it is preferable that the resin layer of at least one of the first interlayer film and the second interlayer film further contains an ultraviolet absorber.

[0076] The ultraviolet absorber is not particularly limited, and examples thereof include 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, and compounds having an indole structure. Among these, the ultraviolet absorber is preferably a compound having a benzotriazole structure from the viewpoint of excellent compatibility with thermoplastic resins and weather resistance. Examples of commercially available compounds having a benzotriazole structure include Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 640, and Tinuvin 928 (manufactured by BAF), and Eversorb 88 and Eversorb 109 (manufactured by Everlight Chemical).

[0077] When the resin layer contains an ultraviolet absorber, the content of the ultraviolet absorbers (the total amount when two or more types are contained) is, for example, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, based on 100% by mass of the total amount of materials constituting the resin layer (one layer). The content of the ultraviolet absorbers is also preferably 5% by mass or less, more preferably 3% by mass or less, based on 100% by mass of the total amount of materials constituting the resin layer (one layer).

[0078] (heat shielding agent) When the interlayer film contains a heat-shielding agent, deterioration of the functional layer due to heat is sufficiently suppressed. For example, it is preferable that the resin layer of at least one of the first interlayer film and the second interlayer film further contains a heat-shielding agent. Furthermore, at least one of the first interlayer film and the second interlayer film may have, separately from or in addition to the resin layer, a layer made of a heat-shielding agent (for example, a layer made of heat-shielding particles described below) or a layer containing a heat-shielding agent.

[0079] The heat-shielding agent is a material capable of absorbing infrared rays (also called heat rays) of 780 nm or more. Specifically, the heat-shielding agent is preferably heat-shielding particles. The heat-shielding 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 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 and cesium-doped tungsten oxide particles (CWO particles); and tungsten oxide particles such as thallium-doped tungsten oxide particles and rubidium-doped tungsten oxide particles. Heat-shielding particles other than these may also be used. Among these, from the viewpoint of high heat ray shielding function, the heat shielding 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 more preferably ITO particles and / or CWO particles.

[0080] The lower limit of the average particle size of the heat-shielding particles is preferably 10 nm or more, and more preferably 20 nm or more. When the average particle size is within this range, the heat-shielding particles have an even greater ability to shield against heat rays. Furthermore, the upper limit of the average particle size of the heat-shielding particles is preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 50 nm or less. When the average particle size is within this range, the heat-shielding particles are less able to shield against visible light. Note that the "average particle size" referred to here refers to the volume-average particle size. The average particle size can be measured using a particle size distribution analyzer ("UPA-EX150" manufactured by Nikkiso Co., Ltd.) or the like.

[0081] 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, which are also near-infrared absorbers. Near-infrared absorbers have an absorption maximum in the near-infrared region, and this absorption maximum is the largest among the absorption maximums present in the wavelength region of 380 nm to 2500 nm. Specifically, near-infrared absorbers have a maximum absorption in the wavelength region of 720 nm or more, preferably in the wavelength region of 750 nm or more and 2000 nm or less.

[0082] The heat-shielding compound is preferably at least one selected from the group consisting of a phthalocyanine compound, a naphthalocyanine compound, and an anthracyanine compound. The phthalocyanine compound is phthalocyanine or a phthalocyanine derivative having a phthalocyanine skeleton, and preferably contains a metal atom. The naphthalocyanine compound is naphthalocyanine or a naphthalocyanine derivative having a naphthalocyanine skeleton, and preferably contains a metal atom. The anthracyanine compound is an anthracyanine or an anthracyanine derivative having an anthracyanine skeleton, and preferably contains a metal atom. In the phthalocyanine compound, the naphthalocyanine compound, and the anthracyanine compound, the metal atom is the central metal of the naphthalocyanine skeleton, the naphthalocyanine skeleton, and the anthracyanine skeleton, respectively.

[0083] Among the above, the heat-shielding compound is preferably at least one selected from the group consisting of phthalocyanine compounds and naphthalocyanine compounds, and more preferably a phthalocyanine compound. Furthermore, the metal atom is preferably a vanadium atom. Therefore, the heat-shielding compound is particularly preferably a phthalocyanine compound containing a vanadium atom. The vanadium atom generally exists in a state where an oxygen atom is bonded to it (V=O). Furthermore, it is also preferable to use tungsten oxide particles and a phthalocyanine compound in combination as the heat-shielding agent, and it is more preferable to use CWO particles and a phthalocyanine compound in combination.

[0084] When the resin layer contains a heat-shielding agent, the content of the heat-shielding agent (total amount when two or more types are contained) is, for example, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.15% by mass or more, based on 100% by mass of the total amount of 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 even more preferably 0.9% by mass or less, based on 100% by mass of the total amount of materials constituting the resin layer (one layer).

[0085] (coloring agent) When the interlayer film contains a colorant, the laminated glass structure is well colored to a desired color tone, improving the design. For example, it is preferable that the resin layer of at least one of the first interlayer film and the second interlayer film further contains a colorant. Examples of the colorant include pigments and dyes, and both pigments and dyes may be used in combination. Note that there are also colorants that are classified as both pigments and dyes.

[0086] Examples of pigments 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, dioxazines, azo compounds, and carbon black.

[0087] Examples of dyes 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, dioxazines, and azo compounds.

[0088] When the resin layer contains a colorant, the content of the colorant (the total amount when two or more types are contained) is, for example, preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, and even more preferably 0.001% by mass or more, based on 100% by mass of the total amount of 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, based on 100% by mass of the total amount of materials constituting the resin layer (one layer).

[0089] When the interlayer film contains a pigment as a colorant, the pigment content (total amount when two or more types are contained) is, for example, preferably 0.0001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.02% by mass or more, based on 100% by mass of the total amount of materials constituting the resin layer (one layer). The pigment content is also preferably 0.15% by mass or less, more preferably 0.12% by mass or less, based on 100% by mass of the total amount of materials constituting the resin layer. The interlayer film may contain only one type of pigment, two or more types, three or more types, or ten or fewer types, or five or fewer types.

[0090] When the interlayer film contains a dye as a colorant, the dye content (total amount when two or more types are contained) is, for example, preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, and even more preferably 0.001% by mass or more, based on 100% by mass of the total amount of materials constituting the resin layer (one layer). The dye content 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 materials constituting one resin layer. The interlayer film may contain only one type of dye, but may also contain two or more types, three or more types, or ten or fewer types, or five or fewer types.

[0091] (Thickness) The thickness of the first interlayer film in the laminated glass structure is not particularly limited, but the layer thickness of the interlayer film (meaning the total thickness in the case of a multilayer film) is preferably 100 μm or more, more preferably 200 μm or more, and even 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 (meaning the total thickness in the case of a multilayer film) is preferably 100 μm or more, more preferably 200 μm or more, and even more preferably 300 μm or more. When each interlayer film has a certain thickness or more, residual air and bubbles are more sufficiently suppressed when the glass sheets are pressure-bonded to each other.

[0092] The film thickness (total thickness) of the first interlayer film is preferably 2000 μm or less, more preferably 1300 μm or less, even 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, even more preferably 1000 μm or less, and particularly preferably 800 μm or less. By ensuring that the thickness of each interlayer film is a certain value or less, the laminated glass structure is prevented from becoming thicker than necessary.

[0093] In the first interlayer film, it is preferable that the thickness of the layer that satisfies the above creep compliance value accounts for a certain percentage or more of the total thickness of the first interlayer film. This more sufficiently suppresses residual air and bubbles when the first interlayer film is pressed against the glass plate. For example, when the first interlayer film is a multilayer film, when the film thickness (total thickness) of the first interlayer film is taken as 100%, the thickness of the layer that satisfies the above creep compliance value is preferably 10 to 100%, more preferably 30 to 100%, even more preferably 50 to 100%, particularly preferably 75 to 100%, and most preferably 100%.

[0094] In the second interlayer film, it is also preferable that the thickness of the layer that satisfies the above creep compliance value accounts for a certain percentage or more of the total thickness of the second interlayer film. This more sufficiently suppresses residual air and bubbles when the second interlayer film is pressed against the glass plate. For example, when the second interlayer film is a multilayer film, when the film thickness (total thickness) of the second interlayer film is taken as 100%, the thickness of the layer that satisfies the above creep compliance value is preferably 10 to 100%, more preferably 30 to 100%, even more preferably 50 to 100%, particularly preferably 75 to 100%, and most preferably 100%.

[0095] Furthermore, when the total thickness of the laminated glass structure is taken as 100%, the thickness of the layer that satisfies the above creep compliance value (the total thickness when two or more such layers are included) is preferably 10 to 50%, more preferably 20 to 40%.

[0096] (Uneven shape) For at least one of the first interlayer film and the second interlayer film, it is preferable that at least one surface of the interlayer film has an uneven shape. More specifically, it is preferable that at least one surface of the interlayer film has a plurality of recesses and a plurality of protrusions, and it is more preferable that both surfaces of the interlayer film have a plurality of recesses and a plurality of protrusions. Furthermore, when the first interlayer film and / or the second interlayer film is a multilayer film, it is preferable that one or both surfaces of the outermost layer of the interlayer film have an uneven shape.

[0097] The recesses preferably have a groove shape with a continuous bottom. A groove shape with a continuous bottom is also referred to as a "ruled line" shape. Therefore, for at least one of the first interlayer film and the second interlayer film, it is preferable that at least one surface of the interlayer film has a ruled line-shaped recess, and it is more preferable that both surfaces of the interlayer film have ruled line-shaped recesses. For example, when attempting to pre-bond a glass plate and an interlayer film using a rubber bag to obtain a laminated glass structure, the edges are temporarily bonded first, which can make it difficult for air to escape from near the center. However, if the surface of the interlayer film has ruled line-shaped recesses, air can also easily escape from near the center, improving adhesion during pre-bonding.

[0098] For at least one of the first interlayer film and the second interlayer film, it is preferable that at least one surface of the interlayer film has a plurality of ruled recesses. In this case, it is preferable that the ruled recesses are arranged in parallel, and it is even more preferable that adjacent ruled recesses are arranged in a regular, parallel arrangement. The ease with which air escapes (also referred to as degassing ability) when a laminate film in which an interlayer film is laminated between a pair of glass plates is pressure-bonded is closely related to the interconnectedness and smoothness of the bottoms of the recesses on the interlayer film surface. By forming the irregular shape of at least one surface of the interlayer film in a shape in which adjacent ruled recesses are arranged in a regular, parallel arrangement, the interconnectedness of the bottoms is improved, and degassing ability is further improved.

[0099] The spacing Sm between adjacent ruled recesses is preferably 100 μm or more and preferably 500 μm or less. When the spacing Sm between the ruled recesses is within this range, even better degassing properties are exhibited. The lower limit of the spacing Sm between the ruled recesses 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 spacing Sm between the ruled recesses is determined by observing the first and second surfaces of the interlayer film (observation area 20 mm × 20 mm) using an optical microscope (SONIC Corporation, "BS-D8000III"), measuring the spacing between adjacent recesses, and then calculating the average of the shortest distances between the bottoms of adjacent recesses.

[0100] In the regularly arranged parallel ruled recesses, adjacent ruled recesses are preferably parallel and equally spaced, but the intervals between all adjacent ruled recesses do not have to be equal. The ruled recesses do not need to have a continuous groove shape across the entire bottom, and may have a dividing wall in part of the bottom. Furthermore, as long as adjacent recesses are parallel and regularly arranged, the groove shape at the bottom does not have to be linear. For example, the groove shape at the bottom may be wavy or zigzag.

[0101] In an interlayer film having an uneven surface on at least one side, the surface roughness (RzJIS94) of the uneven surface is preferably 10 to 80 μm. When the surface roughness is within this range, the interlayer film can exhibit excellent degassing properties. The surface roughness is more preferably 20 to 65 μm, and even more preferably 20 to 50 μm.

[0102] Surface roughness (RzJIS94) can be measured in accordance with JIS B0601 (1994). When the concave portions of the surface texture are in the form of scribed lines, measurements are taken perpendicular to the direction in which the concave portions of the scribed lines continue. For example, a measuring instrument such as the "Surfcorder SE300" manufactured by Kosaka Laboratory Co., Ltd. is used. The cutoff value during 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 palpation needle feed rate is 0.5 mm / sec, and the palpation needle shape has a tip radius of 2 μm and a tip angle of 60°. The measurement is performed in an environment of 23°C and 30% RH. The interlayer film to be measured is allowed to stand in the measurement environment for at least 3 hours before measurement.

[0103] Furthermore, in an interlayer film having an uneven surface on at least one side, the surface roughness (Rc) of the uneven surface is preferably 10 to 40 μm. When the surface roughness is within this range, the interlayer film can exhibit excellent degassing properties. The surface roughness (Rc) is more preferably 15 to 35 μm, and even more preferably 19 to 30 μm. The surface roughness (Rc) can be measured in accordance with JIS B0601 (2013).

[0104] Each interlayer film can be produced by, for example, extrusion molding or press molding, but extrusion molding is preferred. Methods for forming a textured surface on the interlayer film include, for example, an embossing roll method, a calendar roll method, a profile extrusion method, and a melt fracture method. Among these, the embossing roll method is preferably used.

[0105] The first interlayer film included in the laminated glass structure of the present disclosure (i.e., an interlayer film having the creep compliance per interlayer film within the predetermined range) itself was discovered by the present inventors. In other words, a film composed of the first interlayer film included in the laminated glass structure is also included in the present disclosure.

[0106] [Functional layer] The laminated glass structure has a functional layer located between a first interlayer film and a second interlayer film. The functional layer is not particularly limited as long as it has a predetermined function, but is preferably a functional film. The functional film is preferably, for example, a light control film, a display element film, a hologram film, or an optical film, and examples of the optical film include a polarizing film, a retardation film, and an antireflection film. The functional layer may also be a solar cell element, as described below.

[0107] The functional film is more preferably a film including electronic components such as a light control film or a display element film, and even more preferably a light control film or a display element film. That is, the functional layer is preferably at least one selected from the group consisting of a light control film and a display element film.

[0108] Typically, films equipped with electronic components tend to deteriorate or lose their functionality when subjected to autoclaving under high-temperature and high-pressure conditions. However, the laminated glass structure of the present disclosure can be suitably produced even by autoclaving at low temperatures, allowing the functional layer to be incorporated into the laminated glass structure without being deactivated. Therefore, the laminated glass structure of the present disclosure can effectively exhibit the functionality inherent to the functional layer. Furthermore, films equipped with electronic components are prone to complex steps (thickness differences) due to the inclusion of electronic wiring, shielding printed portions, etc., which can easily result in air remaining between the interlayer film and the glass plate or functional layer or bubbles forming during pressure bonding. However, in the present disclosure, such air remaining and bubbles are sufficiently suppressed even when pressure bonding is performed at low temperatures, resulting in the obtained laminated glass structure having excellent transparency and a good appearance. Furthermore, laminated glass structures (e.g., window glass) incorporating a light control film or a display element film have high added value, such as excellent design.

[0109] A light control film is a film-like component equipped with a light control element. Specifically, a light control film preferably comprises two resin films and a light control layer disposed between the two resin films. A light control film having such a configuration has resin materials on the surfaces that contact the first interlayer film and the second interlayer film, which can improve adhesion to these interlayer films.

[0110] The resin film used in the light-control film is not particularly limited, but examples thereof include 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. Among these, from the viewpoint of ease of handling, the resin film is preferably a polyester resin film, and more preferably a PET film. Each of the two resin films may have a conductive layer that forms an electrode on the surface facing the light-control layer.

[0111] The light-controlling layer changes its visible light transmittance by switching between the application and non-application of a voltage between the conductive layers provided on each of the two resin films. Preferred examples of the light-controlling layer include liquid crystal layers such as polymer-dispersed liquid crystal (PDLC) and guest-host crystal (GHLC); suspended particle device (SPD) layers containing a resin matrix and a light-controlling suspension dispersed therein; electrochromic material layers; and electrophoretic layers containing electrophoretic particles and a dispersant for dispersing the electrophoretic particles. Therefore, the light-controlling film preferably includes at least one material selected from the group consisting of PDLC, GHLC, SPD, electrochromic devices, and electrophoretic film devices. In other words, the functional layer preferably includes at least one material selected from the group consisting of PDLC films, GHLC films, SPD films, electrochromic films, and electrophoretic film devices.

[0112] The display element film is a film-like member including a display element. Specifically, the display element film preferably includes a resin film and a display element mounted on the resin film, and more preferably includes two resin films and a display element disposed between the two resin films. A display element film having such a configuration can have improved adhesion to the first interlayer film and the second interlayer film. Note that the resin film used in the display element film can be appropriately selected from the resin films described above with respect to the light control film. Furthermore, the resin film constituting the display element film may be provided with a conductive layer constituting an electrode on the surface facing the display element.

[0113] The film having electronic components is not limited to a light control film or a display element film, but may be other functional films. In other functional films, the electronic components may be mounted on the resin film in the same manner as in the light control film and the display element film, but a preferred embodiment is one in which the electronic components are disposed between a pair of resin films.

[0114] The functional layer may also be a solar cell element. By using a solar cell element in the functional layer, the laminated glass structure of the present disclosure can provide laminated glass for building-integrated photovoltaics (BIPV). The solar cell element is not particularly limited as long as it is a solar cell element used in BIPV, and examples thereof include crystalline or thin-film silicon solar cell elements; compound semiconductor solar cell elements such as CIS, CIGS, CdTe, and GaAs; and organic solar cell elements such as dye-sensitized, organic thin-film, and perovskite solar cells.

[0115] The laminated glass structure of the present disclosure, which is provided with a laminated film comprising a first interlayer film, a functional layer, and a second interlayer film, is useful for a variety of applications in addition to applications in which laminated glass structures are provided, and such laminated films comprising a first interlayer film, a functional layer, and a second interlayer film are included in the present disclosure.

[0116] The laminated film can be produced by, for example, thermocompression bonding a first interlayer film, a functional layer, and a second interlayer film. When incorporating the laminated film into a laminated glass structure, the thermocompression bonding may be performed by first thermocompression bonding the first interlayer film, the functional layer, and the second interlayer film to form a laminated film, and then pressing the laminated film to a glass plate to form a laminated glass structure. Alternatively, the first interlayer film, the functional layer, and the second interlayer film before pressing may be disposed between two glass plates, and when pressing the glass plate and the laminated film together, the first interlayer film, the functional layer, and the second interlayer film may also be pressed together.

[0117] Here, it is preferable to use a functional layer having a smaller planar area than each interlayer film, and to arrange the first interlayer film, functional layer, and second interlayer film so that each interlayer film is present around the functional layer in a plan view (see, for example, Figures 2 and 3 described below). In this case, it is not necessary to arrange a gap filler around the periphery of the functional layer. The laminated glass structure of the present disclosure can be suitably produced without using a gap filler.

[0118] [Layer composition] A laminated glass structure includes a pair of glass sheets (i.e., a first glass sheet and a second glass sheet) and a pair of interlayer films (i.e., a first interlayer film and a second interlayer film) sandwiching a functional layer between them. For example, it is preferable that the first interlayer film is adhered to the first glass sheet and the functional layer, and the second interlayer film is adhered to the second glass sheet and the functional layer, and thus bond these together. This results in a unified structure of the pair of glass sheets, the pair of interlayer films, and the functional layer. The layer structure of this embodiment is represented by G1 / F1 / Z / F2 / G2 (see FIG. 1 ). G1 represents the first glass sheet, G2 represents the second glass sheet, F1 represents the first interlayer film, F2 represents the second interlayer film, and Z represents the functional layer. FIG. 1 is a schematic diagram showing an example of the layer structure of a laminated glass structure.

[0119] Although the above example illustrates an embodiment in which two interlayer films and one functional layer are provided between a pair of glass sheets, three or more interlayer films and two or more functional layers may be provided between the pair of glass sheets. In this case, it is preferable that the interlayer films and the functional layers are alternately arranged, and it is preferable that an interlayer film is provided at the position closest to each glass sheet. For example, when three or more interlayer films and two or more functional layers are provided between a pair of glass sheets, the layer structure of the laminated glass structure is preferably G1 / F3 / Z1 / F4 / Z2 / F5 / G2. Z1 and Z2 may be the same or different and represent functional layers. F3, F4, and F5 may be the same or different and represent interlayer films. At least one of the interlayer films F3, F4, and F5 may be the first interlayer film described above (i.e., an interlayer film whose creep compliance per interlayer film falls within a predetermined range), and the other interlayer films may be the second interlayer film described above.

[0120] [Various physical properties] In the laminated glass structure of the present disclosure, the first glass sheet, the first interlayer film, the functional layer, the second interlayer film, and the second glass sheet preferably have curved shapes such that they all have convex portions in the same direction. For example, taking the laminated glass structure shown in FIG. 1 as an example, the above-mentioned shape refers to a shape in which the glass sheets G1 and G2, the interlayer films F1 and F2, and the functional layer all have convex portions in the same direction (e.g., downward in FIG. 1). Because the laminated glass structure has the first interlayer film with low rigidity and high flexibility as described above, various shapes can be realized. Furthermore, it is preferable that the radius of curvature of the inner surface (i.e., concave surface) of each glass sheet, each interlayer film, and functional layer is 1,000 to 20,000 mm.

[0121] It is also preferable that the thickness of the edge of the laminated glass structure is 99% or less of the thickness of the center of the laminated glass structure, where the thickness of the center is 100%. The center of the laminated glass structure means the centroid (the center in a plan view) of the laminated glass structure. This sufficiently prevents moisture from entering from the edge, making the laminated glass structure highly moisture-resistant and allowing the functions of the functional layer to be exhibited more effectively. When the glass plates, interlayer film, and functional layer are arranged so that the centroids of the respective components overlap, the center of the laminated glass structure corresponds to the center (b) of the region having the functional layer described above.

[0122] It is preferable that the visible light transmittance at a wavelength of 390 nm of the region (a) of the laminated glass structure that does not have a functional layer is lower than the visible light transmittance at a wavelength of 390 nm of the central portion (b) of the region of the laminated glass structure that has a functional layer. This further improves the appearance of the laminated glass structure. A laminated glass structure of this embodiment can be easily obtained, for example, by manufacturing it without using a gap filler. The visible light transmittance can be measured in accordance with JIS R3106 (1998).

[0123] Here, the region (a) of the laminated glass structure that does not have a functional layer refers to a portion (e.g., an edge of the laminated glass structure) where no functional layer is arranged when the laminated glass structure, each interlayer film, and a functional layer having a smaller planar size than these are arranged so that their centroids overlap in a plan view, as described below (see FIGS. 2 and 3). For example, the thickness and transmittance of the region (a) refer to the thickness and transmittance of a portion 30 to 70% away from the intersection point Y1 when the horizontal length between the intersection points Y1 and Y2 is taken as 100% in a plan view of the laminated glass structure. The intersection point Y1 is the point where a center line passing through the center (b) of the region of the laminated glass structure that has the functional layer intersects with the edge of the region having the functional layer. The intersection point Y2 is the point where the center line intersects with the edge of the laminated glass structure.

[0124] The central portion (b) of the region having the functional layer in the laminated glass structure is the central portion of the region where the functional layer is disposed when the laminated glass structure having the functional layer is viewed in plan (i.e., the centroid of the functional layer). The thicknesses are measured using, for example, a multilayer film thickness measuring device, "OptiGauge," manufactured by Lumetrics, Inc., USA. Furthermore, when it is difficult to measure using optical methods, such as when it is difficult to energize the light control film, the laminated glass structure may be appropriately cut out and the thickness measured using a vernier caliper or the like.

[0125] The laminated glass structure preferably has a maximum ultraviolet transmittance of 30% or less at wavelengths of 370 to 400 nm. More precisely, the "maximum ultraviolet transmittance at wavelengths of 370 to 400 nm" refers to the highest transmittance measured at each wavelength from 370 to 400 nm. When the ultraviolet transmittance is within the above range, deterioration of the functional layer due to ultraviolet rays is more sufficiently suppressed. The maximum ultraviolet transmittance is more preferably 20% or less. The ultraviolet transmittance can be measured in accordance with JIS R3106 (1998).

[0126] [Method for producing laminated glass structure] The laminated glass structure of the present disclosure is preferably produced by a method in which the laminated film is disposed between a pair of glass sheets and pressure-bonded to obtain a laminated glass structure. As described above, the use of the first interlayer film sufficiently prevents peeling at the layer interface, residual air, and bubbles from forming, even without the use of a gap filler. Therefore, in the above production method, it is preferable to pressure-bond the glass sheets and the laminated film without disposing a gap filler on the periphery of the functional layer. In this case, the above production method omits the step of disposing a gap filler, thereby simplifying the production process and sufficiently suppressing, for example, a decrease in yield due to shrinkage of the gap filler. Furthermore, the cost of materials used in the gap filler is eliminated, making it extremely useful industrially. Furthermore, the absence of a gap filler can reduce the film thickness at the edges of the laminated glass structure, sufficiently suppressing moisture penetration into the laminated glass structure and effectively demonstrating the effects of the functional layer.

[0127] In the above manufacturing method, first, a first glass plate, a second glass plate, and the laminate film or each member constituting the laminate film (each interlayer film and functional layer) to be disposed between these glass plates are prepared.

[0128] As described above, a functional member may be attached to at least one of the first glass plate and the second glass plate. However, it is preferable that the functional member is attached to the glass plate before it is integrated into the laminated glass structure. Therefore, a glass plate having a functional member attached thereto may be prepared as at least one of the first glass plate and the second glass plate used in the above-mentioned manufacturing method. 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.

[0129] In the above-mentioned manufacturing method, it is preferable to next place the laminate film between a first glass plate and a second glass plate and bond them together to form an integrated laminated glass structure. It is also preferable to place each component constituting the laminate film (i.e., each interlayer film and functional layer) between the first glass plate and the second glass plate and bond them together to form an integrated laminated glass structure incorporating the laminate film. Here, each component constituting the laminate film may be arranged according to the layer structure of the resulting laminated glass structure. For example, the first interlayer film, the functional layer, and the second interlayer film may be arranged in this order between the first glass plate and the second glass plate.

[0130] The lamination (also referred to as lamination or main lamination) may be performed in a two-stage process of preliminary lamination followed by main lamination, or in one stage, but two stages are preferred. The preliminary lamination may be performed using a vacuum bag, a ring bag, a nipper roll, or a press other than these. The main lamination is preferably performed in an autoclave, but may also be performed using other presses. When laminating in one stage, lamination is preferably performed using a vacuum bag or a ring bag, but may also be performed using other presses.

[0131] In the above-mentioned manufacturing method, the lamination may be carried out at a low temperature depending on the heat resistance of the functional layer. As described above, the interlayer film has excellent fluidity, so even if a laminated glass structure is produced by lamination at a low temperature or low pressure, the resulting laminated glass structure can exhibit high safety. Note that, by carrying out the lamination at a low temperature or low pressure, deterioration or deactivation of the functional layer is sufficiently prevented. Furthermore, even if a functional member or the like is attached to the glass plate, deterioration or deactivation of the member is sufficiently prevented.

[0132] From the viewpoint of more reliably preventing deterioration or deactivation of the functional layer, etc., the temperature during lamination is preferably 110° C. or lower, more preferably 100° C. or lower. Furthermore, from the viewpoint of more reliably preventing the generation of residual air and foaming, the temperature during lamination is preferably 60° C. or higher, more preferably 70° C. or higher.

[0133] Similarly, the pressure when performing the lamination is preferably 1.2 MPa or less, more preferably 0.8 MPa or less, from the viewpoint of more reliably preventing deterioration or deactivation of the functional layer, etc. The lower limit of the pressure when performing the lamination is not particularly limited, but when performing the lamination under pressure, for example, in an autoclave, the pressure is preferably 0.05 MPa or more, more preferably 0.1 MPa or more.

[0134] The time for which lamination is carried out at the above temperature and / or pressure is not particularly limited, but is preferably 1 to 120 minutes, and more preferably 5 to 60 minutes.

[0135] In the above manufacturing method, it is preferable to perform preliminary bonding (also referred to as preliminary lamination or temporary pressure bonding) before the lamination, as described above, which can sufficiently suppress a decrease in transmittance and adhesive strength that may occur during the autoclave process under low-temperature conditions.

[0136] Depending on the type of functional layer, etc., the preliminary bonding may be performed under low temperature conditions, or under low temperature and low pressure conditions, in order to further prevent deterioration or deactivation. In this case, for example, the temperature during preliminary bonding is preferably 110°C or lower, more preferably 100°C or lower. Furthermore, in order to further prevent the generation of residual air and foaming, the temperature during preliminary bonding is preferably 60°C or higher, more preferably 70°C or higher. The pressure during preliminary bonding is preferably 0.6 MPa or lower. Furthermore, when preliminary bonding is performed under negative pressure, such as when using a vacuum bag, the pressure during preliminary bonding is preferably 0.3 MPa or lower, more preferably 0.095 MPa or lower, and even more preferably 0.09 MPa or lower. When preliminary bonding is performed under pressure, the pressure is preferably 0.01 MPa or higher, more preferably 0.05 MPa or higher.

[0137] The time for which preliminary bonding is carried out at the above temperature and / or pressure is not particularly limited, but is preferably 0 to 60 minutes, and more preferably 0 to 30 minutes, for example.

[0138] [Application] The laminated glass structure of the present disclosure can be used in a wide variety of applications. For example, the laminated glass structure of the present disclosure is used as window glass for vehicles such as automobiles and trains, various vehicles such as ships and airplanes, various buildings such as buildings, condominiums, detached houses, halls, and gymnasiums, machine tools for cutting and polishing, construction machinery such as shovels and cranes, and partitions inside various vehicles and buildings. Among these, the laminated glass structure is preferably used for vehicles such as automobiles and trains, or for buildings. Thus, both laminated glass for vehicles and laminated glass for buildings composed of the laminated glass structure of the present disclosure have been discovered by the present inventors. The laminated glass structure is particularly preferably used as window glass for vehicles or BIPV, and is particularly preferably used as window glass for vehicles. The window glass for vehicles is preferably the windshield, side glass, rear glass, or roof glass of an automobile or train.

[0139] 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 displays. The laminated glass structure of the present disclosure can also be used as cover glass, etc. for various displays. For example, the laminated glass structure may be applied to in-vehicle displays, etc. [Example]

[0140] The present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass." The weight-average molecular weight of the resin, the Tg of the membrane, and the creep compliance at 90°C per membrane layer were determined according to the methods described above.

[0141] <Materials, etc.> The materials or members used in the examples and comparative examples are as follows. (1) Glass plate Glass plate: Sanshiba Glass Co., Ltd., product name "float plate glass", size 30cm x 30cm x 3mm

[0142] (2) Light-controlling film Light control film 1 A 0.4 mm thick light-control film (referred to as light-control film 1) was used as one of the PDLC films. Light-control film 1 has a structure in which a layer of ITO formed on a PET substrate, a PDLC layer, and a layer of ITO formed on a PET substrate are laminated in this order. Here, the thickness of the PDLC layer is 20 μm. A layer of ITO formed on a PET substrate (thickness 188 μm) was used as the transparent electrode layer.

[0143] Light Control Film 2 A 0.17 mm thick light-control film (referred to as light-control film 2) was used as one of the PDLC films. Light-control film 1 has a structure in which a PET layer with ITO formed thereon, a PDLC layer, and a PET layer with ITO formed thereon are laminated in this order. The PDLC layer is 20 μm thick. In addition, a layer in which ITO is formed on a PET substrate (thickness 188 μm) was used as the transparent electrode layer.

[0144] (3) PET substrate for laminated glass distortion evaluation Toray Industries, product name "Lumirror (registered trademark) T60", film thickness 188 μm

[0145] (4)Thermoplastic resin Preparation Example A1 (Resin 1) A reactor equipped with a stirrer was charged with 1800 ml of ion-exchanged water, 150 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol%), and 50 g of polyvinyl alcohol B (average degree of polymerization 800, degree of saponification 99 mol%). The mixture was heated and dissolved with stirring to obtain a polyvinyl alcohol solution. The solution was then cooled and adjusted to 40°C. 30% hydrochloric acid was added as a catalyst to a hydrochloric acid concentration of 0.9% by mass. The temperature was then adjusted to 20°C, and n-butyl aldehyde was added with stirring to a concentration of 15 mol%. The solution was then adjusted to 13°C, and n-butyl aldehyde was added to a concentration of 54.7 mol%, resulting in the precipitation of a white granular polyvinyl butyral resin. Twenty minutes after the second addition of n-butyl aldehyde, 30% hydrochloric acid was added to a hydrochloric acid concentration of 1.1% by mass. The temperature was then raised to 48°C, and the mixture was aged at this aging temperature for 2 hours. Next, the solution was cooled and neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 1 (polyvinyl butyral resin, hydroxyl group content 30.9 mol%, acetalization degree 68.1 mol%, acetylation degree 0.99 mol%, weight average molecular weight 245,000).

[0146] Preparation example A2 (resin 2) A reactor equipped with a stirrer was charged with 1800 ml of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol%), and the mixture was heated and dissolved while stirring to obtain a polyvinyl alcohol solution. Next, 30% hydrochloric acid was added as a catalyst to this solution so that the hydrochloric acid concentration was 0.2% by mass. The temperature was then adjusted to 15°C, and n-butyl aldehyde was added to 10 mol% while stirring. Subsequently, n-butyl aldehyde was added to 60 mol%, resulting in the precipitation of a white granular polyvinyl butyral resin. Ten minutes after the precipitation, 30% hydrochloric acid was added so that the hydrochloric acid concentration was 1.8% by mass. The temperature was then raised to 53°C, and the mixture was aged at this aging temperature for 2 hours. Next, the solution was cooled and neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 2 (polyvinyl butyral resin, hydroxyl group content 31.5 mol%, acetalization degree 67.8 mol%, acetylation degree 0.7 mol%, weight average molecular weight 267,000).

[0147] Preparation Example A3 (Resin 3): Resin 3 was aged for 2 hours at 63°C instead of 53°C as in Resin 2. Resin 3 was obtained in the same manner as Preparation Example A2 (Resin 2), except that it was aged for 2 hours at 63°C. Resin 3 (polyvinyl butyral resin, hydroxyl group content 30.1 mol%, acetalization degree 69.2 mol%, acetylation degree 0.67 mol%, weight average molecular weight 262,000) was obtained.

[0148] (5) Plasticizers 3GO: Triethylene glycol-bis-(2-ethylhexanoate), manufactured by Sekisui Chemical Co., Ltd., molecular weight 402 TG-1000R: Polyoxypropylene glyceryl ether, NOF Corporation, trade name "Uniol TG-1000R", molecular weight 1000

[0149] (6) Interlayer Preparation example B1 (membrane 1) A resin composition was obtained by mixing 40 parts of plasticizer (3GO) with 100 parts of resin 1. The obtained resin composition was fed into a twin-screw extruder to produce a film-like membrane 1 having a thickness of 760 μm. The Tg and creep compliance J(t) per layer at 90°C of the obtained membrane 1 were measured. The results are shown in Table 1.

[0150] Preparation example B2 (membrane 2) A film-like membrane 2 having a thickness of 760 μm was produced in the same manner as in Preparation Example B1, except that resin 2 was used instead of resin 1. The Tg and creep compliance J(t) at 90° C. of the obtained membrane 2 were measured. The results are shown in Table 1.

[0151] Preparation example B3 (membrane 3) A film-like membrane 3 having a thickness of 760 μm was produced in the same manner as in Preparation Example B1, except that resin 3 was used instead of resin 1. The Tg and creep compliance J(t) at 90° C. of the obtained membrane 3 were measured. The results are shown in Table 1.

[0152] [Table 1]

[0153] Example 1 Two glass plates, two films 1, and a light control film 1 were prepared. One film 1, the light control film 1, 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 that to obtain a laminate 1. As shown in Figures 2 and 3, the glass plate and film 1 each had a planar size of 300 mm x 300 mm, and the light control film 1 had a planar size of 200 mm x 200 mm. They were arranged so that the centroids of the glass plate, film 1, and light control film 1 overlapped in plan view. Figure 2 is a schematic side view of the layer structure of the laminate 1, and Figure 3 is a schematic plan view of the laminate 1.

[0154] The laminate 1 was placed in a vacuum laminator "LAMINATOR 0505S" manufactured by Nisshinbo Mechatronics Inc. and degassed at 90°C and a vacuum of 4 kPa for 5 minutes. Next, while still degassed at 90°C, a pressure of 100 kPa was applied to the laminate 1 using a medium-speed press (pressure increase rate: 2 kPa / s), and then the laminate was held at 90°C and 100 kPa for 3 minutes. Subsequently, pressure bonding was performed for 20 minutes using an autoclave under conditions of 140°C and 1.3 MPa, thereby obtaining a laminated glass structure 1. The laminated glass structure 1 had a good appearance and was highly transparent.

[0155] <Example 2> A laminated glass structure 2 was obtained in the same manner as in Example 1, except that light control film 2 was used instead of light control film 1. The laminated glass structure 2 also had a good appearance and high transparency.

[0156] Example 3 Two glass plates, a film 1, a film 3, and a light control film 2 were prepared. The film 1, the light control film 2, and the film 3 were laminated in this order on one of the glass plates, and the other glass plate was then laminated thereon to obtain a laminate 3. Thereafter, the laminated glass structure 3 was obtained in the same manner as in Example 1. The laminated glass structure 3 also had a good appearance and high transparency.

[0157] Example 4 A laminated glass structure 4 was obtained in the same manner as in Example 2, except that film 2 was used instead of film 1 disposed on both sides of the light control film 2. The laminated glass structure 4 also had a good appearance and high transparency.

[0158] <Comparative Example 1> A laminated glass structure C1 was obtained in the same manner as in Example 1, except that instead of the film 1 disposed on both sides of the light control film 1, a film 3 was used.

[0159] <Evaluation test> The following evaluation tests were carried out using each of the laminated glass structures obtained in the Examples and Comparative Examples. The results are shown in Table 2. Table 2 also lists the types of interlayer films and functional layers constituting each laminated glass structure (glass plates are omitted).

[0160] (Evaluation of distortion and deflection of laminated glass) Laminated glass assemblies corresponding to the laminated glass assemblies obtained in the Examples or Comparative Examples were prepared (see also Figures 2 and 3). Here, a PET substrate was used instead of the light control film because using the light control film as is would make the measurement complicated. That is, the PET substrate, which accounts for most of the thickness of light control film 1 or 2, was used as light control film 1 or 2. A PET substrate (188 μm) was used instead of light control film 1 (thickness 200 μm), and a laminate of two PET substrates (188 μm) was used instead of light control film 2 (thickness 400 μm). The planar size of the PET substrate was the same as that of light control films 1 and 2. Therefore, the layer structure of the laminated glass assemblies used in this evaluation test corresponds to the functional layer Z in Figures 2 and 3 replaced with one or two PET substrates.

[0161] Then, assuming the refractive index of each layer to be 1.5, the thickness of each layer was measured using a multilayer film thickness measuring device "OptiGauge" manufactured by Lumetrics, Inc., USA, and then the thickness difference X was calculated. Note that when it is difficult to conduct electricity through the light control film or when measurement using an optical method is difficult, the laminated glass structure may be appropriately cut out and the actual thickness of each layer may be measured using a vernier caliper to calculate the thickness difference X.

[0162] Specifically, for example, in the case of the laminated glass structure 1 obtained in Example 1, the thicknesses of the first layer film 1, the second layer PET substrate (substitute for light control film 1), and the third layer film 1 of the laminated film excluding the glass plate were measured. Then, as shown in FIG. 3, in the region p having the light control film 1 (PET substrate) in the laminated glass structure 10, the thicknesses of portions p1 and p2 of the first layer (film 1) that contact both ends of the light control film 1 in the width direction and the thickness of portion p3 of the first layer (film 1) that contacts the center of the second layer (PET substrate) in the width direction were measured. The average values ​​of the thicknesses of portions p1 and p2 were then calculated, and the difference X (absolute value) between this average value and the thickness of portion p3 was calculated. Based on this thickness difference X, evaluation was performed according to the following criteria. It can be said that the smaller the thickness difference, the more distortion and deflection are suppressed in the laminated glass structure. A: The thickness difference X is less than 50 μm. C: The thickness difference X is 50 μm or more.

[0163] For convenience, an example where X = 0 is shown in Fig. 2. That is, Fig. 2 shows p1, p2, and p3 as being positioned at approximately the same thickness direction (vertical direction in Fig. 2). However, in reality, the positions of portions p1 and p3 in the thickness direction may differ from each other, and the positions of portions p2 and p3 in the thickness direction may also differ from each other, so that the thickness difference X may exceed 0 mm.

[0164] [Table 2] [Explanation of symbols]

[0165] 10: Laminated glass structure G1, G2, G: Glass plates F1, F2, F: Intermediate film Z: Functional layer

Claims

1. a first glass plate; a first interlayer film; and A functional layer; a second interlayer; and a second glass plate, in this order; The first interlayer film has a creep compliance of 6.0 × 10 at 90 ° C. per layer. －５ Pa －１ That's all A laminated glass structure characterized by:

2. The creep compliance at 90°C per layer is 8.0 x 10 －５ Pa －１ Above 5.0 x 10 －４ Pa －１ 2. The laminated glass structure of claim 1, wherein:

3. The first interlayer film contains a thermoplastic resin.

2. The laminated glass structure according to claim 1.

4. The first interlayer film contains a polyvinyl acetal resin.

2. The laminated glass structure according to claim 1.

5. The polyvinyl acetal resin has a weight average molecular weight of 220,000 to 310,000.

5. The laminated glass structure according to claim 4.

6. The first interlayer film further contains a plasticizer.

4. The laminated glass structure according to claim 3.

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 thereof in which some of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups.

7. The laminated glass structure according to claim 6.

8. The functional layer is at least one selected from the group consisting of a light control film and a display element film.

2. The laminated glass structure according to claim 1.

9. the functional layer is a light control film, The light management film comprises at least one selected from the group consisting of a polymer dispersed liquid crystal (PDLC), a guest host liquid crystal (GHLC), a suspended particle device (SPD), an electrochemical device, and an electrophoretic film device.

2. The laminated glass structure according to claim 1.

10. The laminated glass structure according to any one of claims 1 to 9, comprising the first interlayer film, the functional layer, and a second interlayer film. Laminated film.

11. The laminated glass structure according to any one of claims 1 to 9 is constituted by the first interlayer film. A membrane characterized by:

12. Fabricated without gap filler 10. The laminated glass structure according to claim 1.

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