WO2024122512A1 - Laminated glass and method for manufacturing same - Google Patents

Abstract

This laminated glass comprises: a first laminated glass member (11); a second laminated glass member (12); and a thermoplastic resin film (13) disposed between the first and second laminated glass members, the thermoplastic resin film (13) having a thickness change amount of 80 μm or greater when compressed in a compression creep test that is carried out under specific conditions.

Description

Laminated glass and its manufacturing method

The present invention relates to a laminated glass having first and second laminated glass members and a thermoplastic resin film disposed between them, and a method for manufacturing the laminated glass.

　Conventionally, laminated glass, which is made by inserting an interlayer between two glass sheets to bond them together, has been widely known. Interlayers are often made from plasticized polyvinyl acetal, which is a polyvinyl acetal resin mixed with a plasticizer. Laminated glass is safe because even if it is broken by external impact, few glass fragments are scattered, so it is widely used as window glass for vehicles such as automobiles, aircraft, buildings, etc.

Laminated glass is generally produced by placing two glass sheets with an interlayer film, then performing a preliminary degassing process, followed by heating and pressurizing in an autoclave (ACV) process at a temperature of about 130-140°C and a pressure of about 1.3 MPa to pressurize the glass and the interlayer film together.

In recent years, laminated glass has been required to have various functions, for example, a functional film such as a photochromic element may be placed between two glass sheets. When incorporating a functional film such as a photochromic element into laminated glass, it is known that an interlayer film is placed between the functional film and each glass sheet, and the two glass sheets and the functional film are integrated via the interlayer film (see, for example, Patent Document 2).

International Publication No. 2019/066042

However, functional films such as photochromic bodies are sensitive to heat, and when a glass plate, interlayer film, and functional film are laminated in an autoclave under conventional general temperature and pressure conditions, the functional film is often deactivated. There is also the problem that high heating is required, resulting in large amounts of carbon dioxide emissions. On the other hand, if the lamination is performed without going through the autoclave process or by autoclaving at a low temperature, air bubbles may form between the interlayer film and the glass plate or between the interlayer film and the functional film during lamination, resulting in poor appearance. There is also the problem that when the interlayer film is used in a high-temperature environment or for a long period of time, the air that was dissolved in the interlayer film may form air bubbles, which can cause the appearance to deteriorate.

The objective of the present invention is to provide laminated glass that, even when a functional component such as a photochromic element is incorporated, does not lose the function of the functional component, prevents poor appearance, and maintains a good appearance even after long-term use in a high-temperature environment, as well as a manufacturing method thereof.

After extensive research, the inventors discovered that the above problems could be solved by preparing a thermoplastic resin film so that the thickness change when compressed in a specified compression creep test is 80 μm or more, and then using the thermoplastic resin film to bond first and second laminated glass components together to form laminated glass, leading to the completion of the present invention. That is, the present invention provides the following [1] to [26].

[1] A laminated glass comprising a first laminated glass member, a second laminated glass member, and a thermoplastic resin film (A) disposed between the first and second laminated glass members, wherein the thermoplastic resin film (A) has a thickness change of 80 μm or more when compressed in a compression creep test carried out under the following conditions:
(Compression creep test conditions)
A test sample having a diameter of 8 mm and a thickness of 700 to 900 μm made from the thermoplastic resin film (A) is compressed for 5 minutes under conditions of a load of 410 g and 30° C., and then the thickness (T1) of the test sample is measured. Then, while maintaining the load of 410 g, the temperature is increased from 30° C. to 90° C. at a heating rate of 6° C./min. Then, after compressing for 5 minutes under conditions of a load of 410 g and 90° C., the thickness (T2) of the test sample A is measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the test sample is defined as the thickness change amount.
[2] The laminated glass according to the above [1], wherein the thermoplastic resin film (A) contains a polyvinyl acetal resin.
[3] The laminated glass according to the above [2], wherein the polyvinyl acetal resin is produced by a method including a mixing step of mixing polyvinyl alcohol with an aldehyde and an aging step of aging the mixture obtained in the mixing step, and the aging temperature in the aging step is 30° C. or higher and 65° C. or lower.
[4] The laminated glass according to the above [3], wherein the aging temperature is 40° C. or higher and 57° C. or lower.
[5] The laminated glass according to any one of the above [2] to [4], wherein the polyvinyl acetal resin is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol with an aldehyde, and the polyvinyl alcohol has an average degree of polymerization of 200 or more and 5,000 or less.
[6] The laminated glass according to any one of the above [1] to [5], wherein the thermoplastic resin film (A) has a storage modulus at 90° C. of 1.4×10 ⁵ Pa or more.
[7] The laminated glass according to any one of the above [1] to [6], wherein the weight average molecular weight of the thermoplastic resin film (A) is 230,000 or more and 310,000 or less.
[8] The laminated glass according to any one of the above [1] to [7], wherein the molecular weight distribution (Mw/Mn) of the thermoplastic resin film (A) is 2.5 or less.
[9] The laminated glass according to any one of the above [1] to [8], comprising a pair of thermoplastic resin films and a functional film disposed between them, wherein both of the pair of thermoplastic resin films are the thermoplastic resin films (A).
[10] The laminated glass according to the above [9], wherein the functional film is at least one of a light control film, a display element film, a polarizing film, a retardation film, and an antireflection film.
[11] The laminated glass according to the above [9] or [10], wherein the functional film is a film having an electronic component.
[12] The laminated glass according to any one of the above [1] to [11], wherein at least one of the first laminated glass member and the second laminated glass member is provided with a member constituting a display device.
[13] The laminated glass according to the above [12], wherein the display device is a liquid crystal display device.
[14] The laminated glass according to any one of the above [1] to [13], wherein the thermoplastic resin film (A) contains a plasticizer.
[15] The laminated glass according to the above [14], wherein the plasticizer is at least one selected from the group consisting of triethylene glycol di-2-ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or derivatives thereof in which some of the hydrogen atoms of terminal hydroxyl groups are substituted with alkyl groups.
[16] The laminated glass according to the above [14], wherein the plasticizer is at least one selected from the group consisting of organic ester plasticizers, polyalkylene glycol plasticizers, and alcohol-based plasticizers.
[17] The laminated glass according to any one of the above [14] to [16], wherein the content of the plasticizer is 10 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the thermoplastic resin (a) contained in the thermoplastic resin film (A).
[18] The laminated glass according to any one of the above [1] to [17], wherein the thickness of the plastic resin film (A) is 100 μm or more and 2000 μm or less.
[19] The laminated glass according to any one of the above [1] to [18], wherein the thickness change is 400 μm or less.
[20] The laminated glass according to any one of the above [1] to [19], which is pressure-bonded at a temperature of 110° C. or lower.
[21] The laminated glass according to any one of the above [1] to [20], which is pressure-bonded under a pressure condition of 1.0 MPa or less.
[22] A method for producing laminated glass, comprising disposing at least a thermoplastic resin film (A) between a first laminated glass member and a second laminated glass member, and bonding them together by pressure to obtain a laminated glass, comprising:
The method for producing laminated glass, wherein the thermoplastic resin film (A) has a thickness change of 80 μm or more when compressed in a compression creep test carried out under the following conditions:
(Compression creep test conditions)
A test sample having a diameter of 8 mm and a thickness of 700 to 900 μm made from the thermoplastic resin film (A) is compressed for 5 minutes under conditions of a load of 410 g and 30° C., and then the thickness (T1) of the test sample is measured. Then, while maintaining the load of 410 g, the temperature is increased from 30° C. to 90° C. at a heating rate of 6° C./min. Then, after compressing for 5 minutes under conditions of a load of 410 g and 90° C., the thickness (T2) of the test sample A is measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the test sample is defined as the thickness change amount.
[23] The method for producing a laminated glass according to the above [22], wherein the thermoplastic resin film (A) contains a polyvinyl acetal resin, and the polyvinyl acetal resin is produced by a method including a mixing step of mixing the polyvinyl alcohol and the aldehyde, and an aging step of aging the mixture obtained in the mixing step, and the aging temperature in the aging step is 30° C. or higher and 65° C. or lower.
[24] The method for producing a laminated glass according to the above [23], wherein the aging temperature is 40° C. or higher and 57° C. or lower.
[25] The method for producing a laminated glass according to any one of the above [22] to [24], wherein the laminated glass is obtained by pressing at a temperature of 110° C. or less.
[26] The method for producing a laminated glass according to any one of the above [22] to [25], wherein the laminated glass is obtained by pressing under a pressure condition of 1.2 MPa or less.

The present invention provides laminated glass that, even when a functional component such as a photochromic element is incorporated, does not lose the function of the functional component, prevents poor appearance, and maintains a good appearance even after long-term use in a high-temperature environment, as well as a manufacturing method thereof.

1 shows a laminated glass according to a first embodiment of the present invention. 2 shows a laminated glass according to a second embodiment of the present invention.

<Laminated glass>
The laminated glass of the present invention is a laminated glass comprising a first laminated glass member, a second laminated glass member, and a thermoplastic resin film (A) disposed between the first and second laminated glass members, wherein the thermoplastic resin film (A) changes in thickness by 80 μm or more when compressed in a compression creep test carried out under the following conditions:

(Compression creep test)
First, a test sample having a diameter of 8 mm and a thickness of 700 to 900 μm (for example, 800 μm) is prepared from the thermoplastic resin film (A). Next, the test sample is compressed for 5 minutes under conditions of a load of 410 g and 30° C., and then the thickness (T1) of the test sample is measured. Then, while maintaining the load of 410 g, the temperature is increased from 30° C. to 90° C. at a heating rate of 6° C./min. Then, after compressing for 5 minutes under conditions of a load of 410 g and 90° C., the thickness (T2) of the test sample is measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the test sample is taken as the thickness change amount.

In addition, when the thickness of the thermoplastic resin film (A) is less than 700 μm, the test sample may be prepared by stacking two or more thermoplastic resin films, appropriately pressing them together by hot pressing or the like, adjusting the thickness to 700 to 900 μm by pressing or the like, and then cutting the film into a cylindrical shape with a diameter of 8 mm.
In addition, when the thickness of the thermoplastic resin film (A) exceeds 900 μm, the test sample may be prepared by adjusting the thickness to 700 to 900 μm by hot pressing or the like as necessary, and then cutting the sample into a cylindrical shape with a diameter of 8 mm.
In addition, if the surface of the test sample has unevenness such as embossing, the test sample may be appropriately adjusted by hot pressing or the like so that the surface is flat, and then the test sample may be produced by cutting it into a cylindrical shape with a diameter of 8 mm.

If the thickness change of the thermoplastic resin film (A) is less than 80 μm, when the first and second laminated glass members are integrated by autoclaving at low pressure and low temperature or by other means, residual air or bubbles may be generated between the glass members or the functional film described below and the thermoplastic resin film (A), resulting in poor appearance. Even if no bubbles are generated immediately after the laminated glass is produced, when the laminated glass is used for a long period of time in a high temperature environment, bubbles may be generated between the glass members or the functional film and the thermoplastic resin film (A), resulting in a poor appearance.

The thickness change of the thermoplastic resin film (A) is preferably 90 μm or more, more preferably 120 μm or more, and even more preferably 140 μm or more. When the thickness change is large in this manner, the above-mentioned appearance defect or deterioration of the appearance of the laminated glass can be more appropriately prevented.
The thickness change of the thermoplastic resin film (A) is, for example, 400 μm or less, preferably 320 μm or less, more preferably 220 μm or less, and even more preferably 180 μm or less. If the thickness change is set to a certain value or less, the thermoplastic resin film (A) is prevented from becoming too soft, and for example, the gas dissolved in the thermoplastic resin film is prevented from being released to the outside and becoming bubbles. Therefore, the appearance defect or deterioration can be more appropriately prevented.

[Storage modulus at 90° C.]
The thermoplastic resin film (A) preferably has a storage modulus of 1.4×10 ⁵ Pa or more at 90° C. When the storage modulus of the thermoplastic resin film (A) is equal to or more than the lower limit, the thermoplastic resin film (A) can have a certain mechanical strength while increasing the thickness change amount. Therefore, the performance of the thermoplastic resin film (A) can be improved while preventing poor appearance or deterioration of appearance. In addition, since the thermoplastic resin film (A) has a certain mechanical strength, it becomes easy to convey the film while applying tension, and therefore the thermoplastic resin film (A) can be easily molded by, for example, extrusion molding, and the film formability is also improved.
From the above viewpoints, the storage modulus of the thermoplastic resin film (A) at 90° C. is more preferably 1.8×10 ⁵ Pa or more, further preferably 2.0×10 ⁵ Pa or more, and even more preferably 2.3×10 ⁵ Pa or more.
The storage modulus at 90° C. should be a certain value or less in order to ensure a certain degree of flexibility, for example, 1.0×10 ⁷ Pa or less, preferably 1.0×10 ⁶ Pa or less, and more preferably 5.0×10 ⁵ Pa or less.
The storage modulus is a shear storage modulus, and can be measured under the measurement conditions described in the examples below.

The thickness change and the storage modulus at 90°C can be appropriately adjusted by the thermoplastic resin used in the thermoplastic resin film (A) (hereinafter, the thermoplastic resin contained in the thermoplastic resin film (A) may be referred to as "thermoplastic resin (a)"). For example, they can be adjusted by the molecular weight and molecular weight distribution (Mw/Mn) of the thermoplastic resin (a). Specifically, when the molecular weight is small or the value of the molecular weight distribution (Mw/Mn) is large and the amount of low molecular weight components increases, the thickness change increases while the storage modulus at 90°C tends to decrease.
In addition, when a polyvinyl acetal resin is used, the thickness change amount and the storage modulus at 90° C. can be adjusted by the production conditions when the polyvinyl acetal resin is produced. Specifically, as described later, the thickness change amount and the storage modulus at 90° C. can be adjusted by the aging conditions in the aging step performed when the polyvinyl acetal resin is produced.
It can also be adjusted by the amount and type of plasticizer contained in the thermoplastic resin film (A). For example, when the amount of plasticizer is increased, the thickness change amount increases while the storage modulus at 90 ° C tends to decrease. Furthermore, when an ether-based plasticizer such as a polyoxyalkylene ether-based plasticizer or a polyoxyalkylene ether-based plasticizer is used as the plasticizer, it is easy to increase the thickness change amount while preventing the storage modulus at 90 ° C from decreasing.

[Weight average molecular weight]
The thermoplastic resin film (A) preferably has a weight average molecular weight (Mw) of 230,000 or more and 310,000 or less. When the Mw of the thermoplastic resin film (A) is equal to or more than the lower limit, bubbles are unlikely to occur and the appearance is unlikely to deteriorate even when used for a long period of time under a high temperature environment. In addition, the storage modulus at 90°C is likely to be large, and the strength of the thermoplastic resin film (A) is likely to be improved. On the other hand, when the Mw of the thermoplastic resin film (A) is equal to or less than the upper limit, the flexibility of the thermoplastic resin film (A) is likely to be secured. From these viewpoints, the weight average molecular weight (Mw) of the thermoplastic resin (a) is more preferably equal to or more than 240,000 and 300,000 or less, and more preferably equal to or more than 260,000 and 290,000 or less.

[Molecular weight distribution]
The molecular weight distribution of the thermoplastic resin film (A), which is expressed by the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), is preferably 2.5 or less. If the molecular weight distribution (Mw/Mn) is 2.5 or less, the amount of low molecular weight components contained in the thermoplastic resin film (A) can be suppressed, so that the thickness change amount can be set within a desired range while the storage modulus can be easily increased. The molecular weight distribution (Mw/Mn) of the thermoplastic resin (a) is more preferably 2.3 or less, even more preferably 2.2 or less, and even more preferably 2.0 or less. The molecular weight distribution (Mw/Mn) of the thermoplastic resin (a) is preferably as low as possible, and may be 1.0 or more, but may be 1.1 or more, or may be 1.3 or more in practical use.
The weight average molecular weight (Mw) and number average molecular weight (Mn) of the thermoplastic resin film (A) are measured by gel permeation chromatography. The weight average molecular weight and molecular weight distribution of the thermoplastic resin film (A) are values obtained by measuring the molecular weight of the thermoplastic resin film (A). Therefore, the thermoplastic resin film (A) may contain components other than the thermoplastic resin (a), such as plasticizers, and in that case, Mw and Mn are values that take into account the components other than the thermoplastic resin (a).

Thermoplastic resin (a) used in the thermoplastic resin film (A) of the present invention includes, for example, (meth)acrylic resins, polyvinyl acetal resins, polyvinyl alcohol resins (PVA), polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymers (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and styrene-butadiene copolymer resins. The thermoplastic resins may be used alone or in combination of two or more.

　Among the above, from the viewpoint of achieving both moist heat resistance and impact resistance, the thermoplastic resin (a) is preferably polyvinyl acetal resin, polyurethane resin (PU), ethylene-vinyl acetate copolymer resin (EVA), saponified ethylene-vinyl acetate copolymer (EVOH), ethylene-methacrylic acid copolymer resin, ionomer resin, isobutylene resin, styrene-isoprene copolymer resin, or styrene-butadiene copolymer resin. Furthermore, among the above, the thermoplastic resin (a) is more preferably polyvinyl acetal resin. By using polyvinyl acetal resin, it becomes easier to achieve excellent impact resistance. In addition, it becomes easier to achieve good adhesion to various resin materials and inorganic glass. Below, the polyvinyl acetal resin used in the thermoplastic resin (a) will be described in detail.

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

Polyvinyl alcohol (PVA) can be obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The degree of saponification of polyvinyl alcohol is generally 70 to 99.9 mol %.
The average polymerization degree of PVA is preferably 200 or more, more preferably 500 or more, even more preferably 1000 or more, and even more preferably 1500 or more. When the average polymerization degree is set to be equal to or more than the above lower limit, the penetration resistance of the laminated glass is increased when the PVA is used in the laminated glass. The average polymerization degree of PVA is preferably 5000 or less, more preferably 4000 or less, even more preferably 3500 or less, and even more preferably 2500 or less.
The average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Testing method for polyvinyl alcohol".

As the polyvinyl alcohol used as the raw material of the polyvinyl acetal resin, two or more kinds of polyvinyl alcohols having different average polymerization degrees may be used. In this case, it is preferable to use a mixture of two or more kinds of polyvinyl alcohols as the raw material to produce the polyvinyl acetal resin by the production method described below.
When two or more kinds of polyvinyl alcohols are used, for example, it is preferable to use a first polyvinyl alcohol having an average degree of polymerization of 1500 or more and a second polyvinyl alcohol having an average degree of polymerization of 1000 or less. By using two or more kinds of polyvinyl alcohols having different average degrees of polymerization, it becomes easier to increase the amount of thickness change.
The average degree of polymerization of the first polyvinyl alcohol is preferably 1500 or more and 3500 or less, more preferably 1600 or more and 2500 or less, and even more preferably 1600 or more and 2000 or less. The average degree of polymerization of the second polyvinyl alcohol is preferably 200 or more and 1000 or less, more preferably 300 or more and 900 or less, and even more preferably 400 or more and 700 or less.
When the first and second polyvinyl alcohols are used, the blending ratio of the first polyvinyl alcohol to the second polyvinyl alcohol is not particularly limited, but the blending amount of the second polyvinyl alcohol relative to the total amount of the first and second polyvinyl alcohols is, for example, 1 mass% or more and 70 mass% or less, preferably 3 mass% or more and 50 mass% or less, more preferably 5 mass% or more and 40 mass% or less, and even more preferably 10 mass% or more and 30 mass% or less.
As the polyvinyl alcohol used as the raw material of the polyvinyl acetal resin, two or more kinds of polyvinyl alcohols having different average polymerization degrees may be used. In this case, it is preferable to use a mixture of two or more kinds of polyvinyl alcohols as the raw material to produce the polyvinyl acetal resin by the production method described below.

The amount of hydroxyl groups in the polyvinyl acetal resin is preferably 15 mol% or more, and preferably 38 mol% or less. By making the amount of hydroxyl groups 15 mol% or more, the adhesiveness is easily improved, and when used in a laminated glass, the penetration resistance of the laminated glass is easily improved. In addition, by making the amount of hydroxyl groups 38 mol% or less, flexibility is easily ensured, and it is possible to prevent the laminated glass from becoming too hard or the thickness change amount from decreasing. In addition, by adjusting the amount of hydroxyl groups within the above range, the storage modulus is easily adjusted within a desired range.
The amount of hydroxyl groups is more preferably 20 mol % or more, and even more preferably 25 mol % or more. The amount of hydroxyl groups is more preferably 35 mol % or less, and even more preferably 33 mol % or less.
When a polyvinyl butyral resin is used as the polyvinyl acetal resin, from the same viewpoint, the amount of hydroxyl groups is 15 mol% or more, and preferably 38 mol% or less, more preferably 20 mol% or more, even more preferably 25 mol% or more, more preferably 35 mol% or less, and even more preferably 33 mol% or less.
The amount of hydroxyl groups in the 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 by the procedure described in the Examples.

The acetylation degree of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, and even more preferably 2 mol% or less. When the acetylation degree is equal to or less than the upper limit, the moisture resistance of the polymer film is increased. The acetylation degree is not particularly limited, but is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more.
The degree of acetylation is a molar fraction calculated by dividing the amount of ethylene groups to which acetyl 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 acetyl groups are bonded can be measured by the procedure described in the Examples.

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

The above-mentioned degree of acetalization is a molar fraction calculated by subtracting the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups from the total amount of ethylene groups in the main chain, and dividing the result by the total amount of ethylene groups in the main chain, expressed as a percentage. The degree of acetalization (degree of butyralization) may be calculated based on the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups, which are calculated by the procedure described in the Examples.

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

When the thermoplastic resin film (A) uses a polyvinyl acetal resin as the thermoplastic resin (a), the thermoplastic resin film (A) may contain a thermoplastic resin other than the polyvinyl acetal resin as long as the effects of the present invention are achieved. The thermoplastic resin other than the polyvinyl acetal resin is as described above.
However, it is preferable that the thermoplastic resin film (A) is mainly composed of polyvinyl acetal resin. Specifically, the content of polyvinyl acetal resin is, for example, 50 mass% or more, preferably 70 mass% or more, more preferably 90 mass% or more, and most preferably 100 mass% based on the total amount of the thermoplastic resin (a) contained in the thermoplastic resin film (A). Therefore, the thermoplastic resin (a) contained in the thermoplastic resin film (A) of the present invention may be composed only of polyvinyl acetal resin.

(Method of producing polyvinyl acetal resin)
The polyvinyl acetal resin is preferably produced by a production method including a mixing step of mixing the polyvinyl alcohol and the aldehyde, and an aging step of aging the mixture obtained in the mixing step.

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 for promoting the acetalization reaction may be further added. For example, aldehyde may be added under low temperature conditions of about 0 to 20°C to a mixture of polyvinyl alcohol and an acid catalyst. A solvent such as water is usually also added.
When two or more kinds of polyvinyl alcohols are used in combination (for example, when two or more kinds of polyvinyl alcohols having different molecular weights are used), it is advisable to mix the two or more kinds of polyvinyl alcohols with an aldehyde.

The aging step is not particularly limited, but may be, for example, a catalyst such as an acid catalyst added to the mixture (reaction mixture) obtained by the mixing step, heated to an aging temperature, and maintained at the aging temperature for a certain period of time. In this production method, acetalization of polyvinyl alcohol proceeds in the mixing step and the aging step to obtain a polyvinyl acetal resin.
The reaction mixture may be maintained at the aging temperature for a certain period of time, and then appropriately cooled and neutralized, and then washed with water and dried, if necessary.

Examples of the acid catalyst added in the mixing step and the aging step include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, etc. In the aging step, the concentration of the acid catalyst may be adjusted to, for example, about 0.5% by mass or more and 5% by mass or less, preferably about 1% by mass or more and 2.5% by mass or less.
The aging temperature in the aging step may be relatively low, for example, from 30° C. to 65° C., preferably from 35° C. to 60° C., and more preferably from 40° C. to 57° C. The time for which the aging temperature is maintained (aging time) may be longer than a certain time, for example, from 75 minutes to 180 minutes, preferably from 90 minutes to 150 minutes, and more preferably from 100 minutes to 140° C.
It is presumed that when the aging temperature and aging time are within the above desired ranges, the hydroxyl groups in the polyvinyl acetal resin tend to be uniformly distributed in the molecule, and thus the thickness change amount can be increased without significantly decreasing the storage modulus at 90°C. In addition, the amount of low molecular weight components tends to decrease, and the molecular weight distribution (Mw/Mn) tends to decrease. The reason for the decrease in the amount of low molecular weight components is unclear, but it is presumed to be due to the promotion of intermolecular crosslinking.

(Plasticizer)
The thermoplastic resin film (A) preferably contains a plasticizer. The thermoplastic resin film (A) becomes flexible by containing a plasticizer, and the adhesiveness and penetration resistance of the thermoplastic resin film (A) to various adherends can be improved. In addition, the thickness change amount can be easily increased.

Examples of the plasticizer include organic ester plasticizers, organic phosphorus-based plasticizers such as organic phosphate ester plasticizers and organic phosphite ester plasticizers, organic ether-based plasticizers such as polyalkylene glycol-based plasticizers, and alcohol-based plasticizers.
The plasticizers may be used alone or in combination of two or more. Among the above, organic ester plasticizers and organic ether plasticizers are preferred.

Preferred organic ester plasticizers include monobasic organic acid esters and polybasic organic acid esters. Examples of monobasic organic acid esters include esters of glycols and monobasic organic acids. Examples of glycols include polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the number of repeating alkylene units is 2 to 10, preferably 2 to 4. Examples of glycols may also include monoalkylene glycols having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms (i.e., one repeating unit).
Specific examples of the glycol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and butylene glycol.
Examples of the monobasic organic acid include organic acids having 3 to 10 carbon atoms, and specific examples thereof include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, n-nonyl acid, and decylic acid.

Specific examples of monobasic organic acids 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, and triethylene glycol di-n-octanoate. Examples include diethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicapryate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, ethylene glycol di-2-ethylbutyrate, 1,2-propylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, and 1,2-butylene glycol di-2-ethylbutyrate.

Examples of polybasic organic acid esters include ester compounds of dibasic organic acids having 4 to 12 carbon atoms, such as adipic acid, sebacic acid, and azelaic acid, with alcohols having 4 to 10 carbon atoms. The alcohols having 4 to 10 carbon atoms may be linear, may have a branched structure, or may have a cyclic structure.
Specific examples of the adipate include dibutyl sebacate, dioctyl azelaate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl carbitol adipate, and mixed adipates. Oil-modified alkyd sebacate may also be used. Examples of the mixed adipate include adipates made from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms.

The organic ester plasticizer is not limited to the complete esters of the above-mentioned esters, and may be a partial ester. For example, it may be a partial ester of glycol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol. A specific example is triethylene glycol-mono-2-ethylhexanoate.
Furthermore, it may be a partial ester of a monobasic organic acid with a trihydric or higher alcohol such as glycerin. Examples of the monobasic organic acid include monobasic organic acids having 3 to 24 carbon atoms, preferably 6 to 18 carbon atoms. Specific examples of the partial ester of a monobasic organic acid with a trihydric or higher alcohol include a mono- or diester of glycerin and stearic acid, and a mono- or diester of glycerin and 2-ethylhexyl acid.
Of the above-mentioned organic ester plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferably used.

Organophosphorus plasticizers include phosphate esters such as tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

Polyalkylene glycol plasticizers include polyoxyalkylene compounds having a polyoxyalkylene structure, specifically polyhydric alcohol compounds such as glycol, ester compounds of glycol and monobasic organic acid or polybasic organic acid, ether compounds of monohydric or polyhydric alcohol and polyoxyalkylene, etc. Here, glycols include polyoxyalkylene glycols and derivatives thereof. Polyoxyalkylenes include polyoxyethylene, polyoxypropylene, polyoxybutylene, random copolymers or block copolymers thereof, etc. The polyoxyalkylene compounds may be polyhydric alcohol compounds, ester compounds, ether compounds, or other compounds, as described above.

Polyoxyalkylene compounds include polyoxyalkylenes and their derivatives. More specifically, they include polyoxyalkylene glycols composed of the above-mentioned polyoxyalkylenes, and ether compounds of polyoxyalkylenes and polyhydric alcohols. All of these may have hydroxyl groups at their terminals, but they may also be derivatives in which some or all of the hydrogen atoms at the terminal hydroxyl groups have been replaced 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, and is preferably 1 to 4.

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.

Ether compounds of polyoxyalkylenes and polyhydric alcohols include ether compounds of polyhydric alcohols such as glycerol, diglycerol, trimethylolpropane, erythritol, pentaerythritol, and bisphenol A with polyoxyalkylenes, and specific examples include polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, etc. In addition, derivatives in which some or all of the hydrogen atoms of the terminal hydroxyl groups are 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 the terminal hydroxyl groups of ether compounds are 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.

Among the above, the polyoxyalkylene compounds are preferably those having a polyoxyethylene, polyoxypropylene, or polyoxyethylene polyoxypropylene structure, and more preferably those having a polyoxypropylene or polyoxyethylene polyoxypropylene structure. Specifically, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or derivatives in which some of the hydrogen atoms of the terminal hydroxyl groups of these are substituted with alkyl groups are preferred.

Alcohol-based plasticizers include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, and pentaerythritol. Of these, trimethylolpropane is preferred.

The above plasticizers can be used alone or in combination of two or more. Among the above plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or derivatives in which some of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups are preferred, with triethylene glycol-di-2-ethylhexanoate (3GO) being more preferred.

The content of the plasticizer in the thermoplastic resin film (A) is not particularly limited, but is preferably 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the thermoplastic resin (a). When the content of the plasticizer is 10 parts by mass or more, the thermoplastic resin film (A) becomes moderately flexible, and the adhesiveness of the thermoplastic resin film (A) and the penetration resistance of the laminated glass become good. Furthermore, the thickness change amount is also easily increased.
On the other hand, when the content of the plasticizer is 100 parts by mass or less, separation of the plasticizer from the thermoplastic resin film (A) is prevented, and a decrease in the storage modulus and an excessive increase in the thickness change can also be prevented.
The above content of the plasticizer is more preferably 15 parts by mass or more, even more preferably 22 parts by mass or more, even more preferably 30 parts by mass or more, and more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, and particularly preferably 45 parts by mass or less.

The thermoplastic resin film (A) may appropriately contain known additives used in combination with the thermoplastic resin (a) in addition to the plasticizer. That is, the thermoplastic resin film (A) may be composed of a thermoplastic resin (a) such as a polyvinyl acetal resin, or a thermoplastic resin (a) and a plasticizer, but may also contain additives other than the plasticizer that are mixed as necessary.
Specific examples of additives other than plasticizers include ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, adhesion regulators, colorants (pigments or dyes), fluorescent brighteners, and crystal nucleating agents.

<Coloring Agent>
The thermoplastic resin film (A) may or may not contain a colorant. By using the colorant, the laminated glass can be well colored to a desired color tone. The colorant may be used alone or in combination of two or more. The thermoplastic resin film (A) may contain only one type of colorant, two or more types, three or more types, 10 or less types, or 5 or less types.

The colorants include pigments and dyes. The colorants may be pigments, dyes, or both pigments and dyes. There are also colorants that are classified as both pigments and dyes.

Pigments:
The colorant may contain a pigment or may be a pigment. The thermoplastic resin film (A) may contain a pigment or may not contain a pigment. The pigment may be used alone or in combination of two or more. The thermoplastic resin film (A) may contain only one type of pigment, two or more types, three or more types, 10 or less types, or 5 or less types.

The above 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.

When the thermoplastic resin film (A) contains a pigment, the content of the pigment in 100% by mass of the thermoplastic resin film (A) is preferably 0.0001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, preferably 0.15% by mass or less, and more preferably 0.12% by mass or less. When the content of the pigment is equal to or more than the lower limit and equal to or less than the upper limit, the effects of the present invention can be exhibited even more effectively.

dye:
The colorant may contain a dye or may be a dye. The thermoplastic resin film (A) may contain a dye or may not contain a dye. The dye may be used alone or in combination of two or more. The thermoplastic resin film (A) may contain only one dye, two or more dyes, three or more dyes, 10 or less dyes, or 5 or less dyes.

The above 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.

When the thermoplastic resin film (A) contains a dye, the content of the dye in 100% by mass of the thermoplastic resin film (A) is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, even more preferably 0.001% by mass or more, preferably less than 0.015% by mass, and more preferably 0.01% by mass or less. When the content of the dye is equal to or more than the lower limit and equal to or less than the upper limit (or less than the upper limit), the effects of the present invention can be exhibited even more effectively.

When the thermoplastic resin film (A) contains a colorant, the content of the colorant in 100% by mass of the thermoplastic resin film (A) is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, even more preferably 0.001% by mass or more, preferably 0.15% by mass or less, and more preferably 0.12% by mass or less. When the content of the colorant is equal to or more than the lower limit and equal to or less than the upper limit (or less than the upper limit), the effects of the present invention can be exhibited even more effectively.

The thickness of the thermoplastic resin film (A) is not particularly limited, but is, for example, 100 μm or more and 2000 μm or less, preferably 200 μm or more and 1300 μm or less, and more preferably 300 μm or more and 1000 μm or less. When the thickness of the thermoplastic resin film (A) is equal to or more than the above lower limit, the impact resistance can be increased and adhesion to laminated glass members and the like can be easily ensured. On the other hand, when the thickness is equal to or less than the above upper limit, the thickness of the laminated glass can be prevented from becoming unnecessarily thick.

The thermoplastic resin film (A) may be a single-layer film having a single layer structure. When the thermoplastic resin film (A) is composed of a single layer, the single-layer thermoplastic resin film (A) may have the composition as described for the thermoplastic resin film (A) above. That is, the layer constituting the single-layer thermoplastic resin film (A) contains the thermoplastic resin (a) described above, and may contain a plasticizer as necessary, and may contain additives other than the plasticizer as appropriate.

The thermoplastic resin film (A) may be a multilayer film of two or more layers. The multilayer film may have the composition of the entire film as described in the above thermoplastic resin film (A), but each layer (hereinafter also referred to as the "first layer") may have the composition as described in the above thermoplastic resin film (A). That is, each first layer contains the thermoplastic resin (a) as described in the above thermoplastic resin film (A), and may contain a plasticizer as necessary, and may be appropriately blended with additives other than the plasticizer, and each first layer preferably contains the above polyvinyl acetal resin as the thermoplastic resin (a). The details of the thermoplastic resin (a), plasticizer, and additives in each first layer of the multilayer film, and the details of the content of each component are as described in the above thermoplastic resin film (A). However, the thermoplastic resin (a) that is the basis of the content is the thermoplastic resin (a) contained in each first layer. And each first layer may satisfy the above-mentioned physical properties (thickness change amount, storage modulus, weight average molecular weight, molecular weight distribution). In a multilayer film, each of the first layers may be of the same composition or of different composition.
The multilayer film may also be a laminate of the above-mentioned first layer and a layer other than the first layer (hereinafter also referred to as the "second layer"). Specifically, for example, a three-layer structure of the first layer/second layer/first layer can be mentioned. In the layer structure of the first layer/second layer/first layer, the second layer may be provided in a plurality of layers. The second layer may be a thermoplastic resin layer. In addition, it is preferable that the first layer occupies a certain proportion or more of the total thickness of the thermoplastic resin film (A). Specifically, the total thickness of the first layer is preferably 0.3 to 1, more preferably 0.5 to 1, and even more preferably 0.75 to 1 with respect to the total thickness of the thermoplastic resin film (A).

The method for producing the thermoplastic resin film (A) is not particularly limited, and it may be produced by a conventionally known method such as extrusion molding or press molding, but production by extrusion molding is preferred.
The thermoplastic resin film (A) may have an uneven shape on one or both surfaces. The method for forming the uneven shape is not particularly limited, and examples thereof include a lip embossing method, an embossing roll method, and a calendar roll method.

[First and second laminated glass members]
The first and second laminated glass members used in the laminated glass include glass plates. The glass plates may be either inorganic glass or organic glass, but inorganic glass is preferred. The inorganic glass is not particularly limited, but includes clear glass, float glass plate, tempered glass, colored glass, polished glass plate, figured glass, wired glass plate, lined glass plate, ultraviolet absorbing glass plate, infrared reflecting glass plate, infrared absorbing glass plate, green glass, etc.
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, polyester plate such as acrylonitrile styrene copolymer plate, acrylonitrile butadiene styrene copolymer plate, polyethylene terephthalate plate, fluorine-based resin plate, polyvinyl chloride plate, chlorinated polyvinyl chloride plate, polypropylene plate, polystyrene plate, polysulfone plate, epoxy resin plate, phenol resin plate, unsaturated polyester resin plate, polyimide resin plate, etc. The organic resin plate may be appropriately subjected to a surface treatment or the like.

The first and second laminated glass members may be made of the same material or different materials, for example, one may be inorganic glass and the other organic glass, but it is preferred that both the first and second laminated glass members are inorganic glass or organic glass.
The thickness of each of the glass plates used in the first and second laminated glass members is not particularly limited, but is, for example, about 0.1 to 15 mm, and preferably 0.5 to 5 mm. The thicknesses of the glass plates may be the same or different from each other.

The laminated glass member may be composed of a single glass plate, or may be composed of glass plates to which other members are attached. The laminated glass member may preferably have various functions provided by attaching functional members to the glass plates.
The other member may be, for example, a member constituting an electronic device, an optical member, or the like, but is preferably a member constituting a display device. The display device may be a liquid crystal display device, an organic EL display device, an LED display device, a segment display device, or the like. Of these, the display device is preferably a liquid crystal display device.

The display device may be, for example, a display panel having a glass plate as a substrate on which a display layer such as a liquid crystal layer or an organic EL layer, light-emitting elements, etc. are provided, and the glass plate that serves as the substrate of the display panel may be used as a laminated glass member.
Furthermore, functional layers such as a conductive layer constituting a functional film, electrode, sensor, etc., described below, an antireflection layer, a hard coat layer, etc., may be laminated on the glass plate, and the laminated glass member may be a glass plate on which such a functional film or functional layer is laminated.
Therefore, the bonding surface with the thermoplastic resin film (A), on which the thermoplastic resin film (A) is directly laminated, may be the glass plate itself, or it may be the surface of a functional film or a functional layer.

[Layer structure of laminated glass]
Next, the layer structure of the laminated glass will be described in detail with reference to the drawings and with reference to the embodiments. As shown in Fig. 1, in the first embodiment of the present invention, the laminated glass is a laminated glass 10 in which one thermoplastic resin film 13 is provided between first and second laminated glass members 11 and 12. In the laminated glass 10, the thermoplastic resin film 13 is bonded to both the first and second laminated glass members 11 and 12 to join them. The thermoplastic resin film 13 is the above-mentioned thermoplastic resin film (A).

In the first embodiment, as described above, at least one of the first and second laminated glass members 11, 12 may have other members attached thereto. Specifically, the laminated glass member may have a functional member constituting an electronic device such as a display device, an optical member, or the like attached thereto, or may have the above-mentioned functional film, functional layer, or the like laminated thereon.
In particular, it is preferable that a member constituting a display device, particularly a liquid crystal display device, is attached to at least one of the first and second laminated glass members 11, 12. That is, it is preferable that at least one of the first and second laminated glass members 11, 12 is a glass plate constituting a display device, and it is preferable that the laminated glass 10 is provided with a display device using at least one of the first and second laminated glass members 11, 12 as a substrate.

In the first embodiment, by using the above-mentioned thermoplastic resin film (A) as the thermoplastic resin film 13, even if the first and second laminated glass members 11 and 12 are integrated under low pressure and low temperature conditions, it is possible to suppress poor appearance or deterioration of the appearance due to remaining air or bubbles. On the other hand, even if a functional member is provided on either one of the first and second laminated glass members 11 and 12, since they are integrated by pressing under low pressure and low temperature conditions, it is possible to prevent the functional member attached to the laminated glass member from deteriorating or becoming inactive.

In another preferred embodiment, the laminated glass may have multiple thermoplastic resin films between the first and second laminated glass members. When multiple thermoplastic resin films are provided, each of the thermoplastic resin films may be the thermoplastic resin film (A) described above. When multiple thermoplastic resin films are provided, by making all of the thermoplastic resin films the thermoplastic resin film (A) described above, it is possible to suppress poor appearance or deterioration of appearance due to remaining air or bubbles, even when the first and second laminated glass members are integrated under low pressure and low temperature conditions.

One embodiment of the laminated glass in which a plurality of thermoplastic resin films are provided is shown as a second embodiment in Fig. 2. As shown in Fig. 2, in the laminated glass 20 according to the second embodiment, thermoplastic resin films 13A, 13B are provided between the first and second laminated glass members 11, 12, and a functional film 14 is further provided between the thermoplastic resin films 13A, 13B. Both of the thermoplastic resin films 13A, 13B are the above-mentioned thermoplastic resin films (A).
In the laminated glass 20, the thermoplastic resin film 13A is adhered to both the first laminated glass member 11 and the functional film 14, joining them together, and the thermoplastic resin film 13B is adhered to both the second laminated glass member 12 and the functional film 14, joining them together. As a result, the first and second laminated glass members 11, 12, together with the functional film 14, are integrated by the thermoplastic resin films 13A, 13B, which are the thermoplastic resin film (A).

In the second embodiment, the laminated glass 20 is preferably integrated at low temperature and low pressure, but even if it is integrated at low temperature and low pressure, the use of the thermoplastic resin film (A) can prevent the occurrence of poor or deteriorated appearance due to remaining air or bubbles. Furthermore, by integrating the laminated glass 20 at low temperature and low pressure, it is possible to prevent the functional film 14 from deteriorating or becoming inactive.

In the second embodiment, two thermoplastic resin films and one functional film are provided, but three or more thermoplastic resin films and two or more functional films may be provided. In this case, the thermoplastic resin films and the functional films may be arranged alternately in the first and second laminated glass members. A thermoplastic resin film may be arranged in each of the positions closest to the first and second laminated glass members (i.e., the bonding surfaces with the laminated glass members), and it is preferable that each of the thermoplastic resin films is the thermoplastic resin film (A).
For example, when three thermoplastic resin films and two functional films are provided, they may be arranged in the following order: first laminated glass member/thermoplastic resin film/functional film/thermoplastic resin film/functional film/thermoplastic resin film/second laminated glass member. When three or more thermoplastic resin films are provided, the above-mentioned thermoplastic resin film (A) may be used as each thermoplastic resin film.
When a plurality of thermoplastic resin films are provided in the laminated glass, the configuration of each thermoplastic resin film may be the same or different.

When two or more thermoplastic resin films are provided, as described above, it is preferable to use the thermoplastic resin film (A) as each thermoplastic resin film, but in the present invention, at least one thermoplastic resin film may be the above-mentioned thermoplastic resin film (A). For example, in a laminated glass having a pair of thermoplastic resin films and a functional film therebetween, one of the pair of thermoplastic resin films may be the thermoplastic resin film (A). Of course, it is preferable that both of the pair of thermoplastic resin films are the thermoplastic resin films (A).
It is preferable that a thermoplastic resin film is disposed on the bonding surfaces to the first and second laminated glass members, and it is particularly preferable that both of the bonding surfaces to the first and second laminated glass members are formed of a thermoplastic resin film (A).

[Functional film]
The functional film used in the present invention may be a light control film, a display element film, or an optical film such as a polarizing film, a retardation film, or an anti-reflection film.
The functional film may be laminated on the first and second laminated glass members as described above, but as shown in the second embodiment, it is preferable that the functional film is disposed between a pair of thermoplastic resin films in the laminated glass.

Among the above, the functional film is preferably a film having electronic components such as a light control film or a display element film. Films having electronic components tend to deteriorate or lose their functions when integrated in an autoclave under high temperature and high pressure conditions, but according to the present invention, laminated glass can be produced under low temperature and low pressure conditions without causing poor appearance. Therefore, even films having electronic components can be incorporated into laminated glass for practical use.
Furthermore, when laminated glass having either the light control film or the display element film is incorporated into various types of window glass, window glass with high added value can be provided. Therefore, in the present invention, it is desirable to use either of these as a functional film.

The light control film is a film-like member having a light control element. Specifically, the light control element is preferably a light control film having two resin films and a light control layer disposed between the two resin films. Therefore, the adhesive surface of the light control film with the thermoplastic resin film (A) becomes a resin material, and the adhesive strength to the thermoplastic resin film (A) tends to be high. The resin film used for the light control element is not particularly limited, but examples include polyester resin films such as PET film and PEN film, (meth)acrylic resin film, TAC film, PES resin film, polyimide resin film, etc. Among these, polyester resin film is preferable from the viewpoint of handling, and PET film is more preferable. In addition, a conductive layer constituting an electrode is provided on the surface of each of the two resin films facing the light control layer.

The light-controlling layer changes the visible light transmittance by switching between application and non-application of a voltage between the conductive layers of two resin films. The light-controlling layer is composed of a liquid crystal layer such as a polymer-dispersed liquid crystal (PDLC), and the light-controlling film may be a PDLC film. The light-controlling film may also be an SPD (Suspended Particle Device) film, an electrochromic film, an electrophoretic film device, a GHLC (Guest-Host Liquid Crystal) film, or the like. Thus, the light-controlling layer may be an SPD layer containing a resin matrix and a light-controlling suspension dispersed in the resin matrix, an electrochromic material layer, or an electrophoretic layer containing electrophoretic particles and a dispersant for dispersing the electrophoretic particles. It may also be a layer composed of host molecules and guest molecules.

The display element film is a film-like member having a display element. Examples of the display element film include a resin film and a display element mounted on the resin film. The display element film may be a pair of resin films with a display element provided therebetween. With such a configuration, the display element film can be easily adhered to the thermoplastic resin film with high adhesiveness. Note that the resin film used for the display element film can be appropriately selected from the resin films listed in the light control film.
In addition, in the display element film, the resin film may be provided with a conductive layer forming an electrode on the surface on the display element side. Examples of the display element include an organic EL element, an LED display, and a segment display, and among these, an organic EL element is preferable. Therefore, the organic EL film is preferable as the display element film.

In addition, the functional film having electronic components is not limited to the above-mentioned display element film and light control film, but may be other functional films. The electronic components may be mounted on the resin film in the same manner as the display element film and light control film, but a preferred embodiment is one in which the electronic components are arranged between a pair of resin films.
The thickness of the functional film is not particularly limited, but is, for example, 0.01 mm or more and 0.50 mm or less, preferably 0.01 mm or more and 0.20 mm or less, and more preferably 0.02 mm or more and 0.10 mm or less.

<Method of manufacturing laminated glass>
The laminated glass of the present invention may be produced by a production method in which at least a thermoplastic resin film (A) is placed between a first laminated glass member and a second laminated glass member, and these members are bonded together by pressure to obtain a laminated glass.

In the above-described production method, first, a first and a second laminated glass member and a member to be placed between the first and the second laminated glass members (the thermoplastic resin film (A), or a functional film and the thermoplastic resin film (A)) are prepared.
Here, the member to be placed between the first and second laminated glass members may be appropriately selected depending on the structure of the laminated glass to be obtained. For example, in the first embodiment, a single thermoplastic resin film (A) may be prepared. Also, for example, in the second embodiment, two thermoplastic resin films (A) and one functional film may be prepared. When a functional film is used, the functional film and the thermoplastic resin film (A) may be placed between the first and second laminated glass members as separate members, or may be integrated by pressing in advance and placed between the first and second laminated glass members.

As described above, in the laminated glass, a functional member may be attached to at least one of the first and second laminated glass members, and the functional member may be attached to the laminated glass member before it is integrated into the laminated glass. Therefore, in the above manufacturing method, at least one of the first and second laminated glass members may be prepared as a laminated glass member having a functional member attached thereto. For example, as described above, in the case where the laminated glass member constitutes a substrate for a display device, at least one of the first and second laminated glass members may be prepared as a display device.

In the present production method, as described above, the thermoplastic resin film (A), or the thermoplastic resin film (A) and the functional film, are disposed between the first laminated glass component and the second laminated glass component, and these are bonded together to form an integrated laminated glass.
Here, the thermoplastic resin film (A), or the thermoplastic resin film (A) and the functional film may be disposed in accordance with the layer structure of the obtained laminated glass. For example, in the second embodiment, the thermoplastic resin film (A), the functional film, and the thermoplastic resin film (A) may be disposed between the first and second laminated glass members in this order.

The lamination may be performed in a vacuum bag, an autoclave, or by a press machine other than these, but among these, it is preferable to perform it in a vacuum bag. Also, before performing the lamination, temporary pressure bonding may be performed using a rubber roll or the like.

In this manufacturing method, the above bonding needs to be performed under low temperature and low pressure conditions; specifically, it is preferable to perform compression bonding at a temperature of 110°C or less and a pressure of 1.2 MPa or less. By performing bonding under low temperature and low pressure conditions in this way, it is possible to prevent the functional film and the functional members (e.g., display devices) attached to the first and second laminated glass members from deteriorating or becoming inactive.

The temperature during lamination is preferably 100° C. or lower from the viewpoint of more reliably preventing deterioration or deactivation of the functional component, and is preferably 60° C. or higher, more preferably 70° C. or higher, from the viewpoint of preventing the generation of residual air or foaming.
In order to more reliably prevent deterioration or deactivation of the functional member, the pressure during lamination is preferably 1.0 MPa or less. When lamination is performed under negative pressure, such as when a vacuum bag is used, the pressure may be, for example, 0.095 MPa or less, preferably 0.08 MPa or less, and more preferably 0.06 MPa or less.
The pressure during lamination is not particularly limited with respect to the lower limit, but when lamination is performed under pressure such as in an autoclave, the pressure is preferably 0.5 MPa or more, more preferably 0.7 MPa or more. When lamination is performed under negative pressure such as in a vacuum bag, the pressure is preferably 0.001 MPa or more, more preferably 0.005 MPa or more.
The time for lamination under the above temperature and pressure is not particularly limited, but is, for example, 5 to 120 minutes, and preferably 10 to 60 minutes.

The laminated glass of the present invention can be used for various applications without any particular limitation, including 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 machines such as shovels and cranes, and partitions inside various vehicles and various buildings. Among these, applications for vehicles such as automobiles are preferred, and use as window glass for vehicles is more preferred.
The laminated glass of the present invention may be used for various display applications, for example, when a display device is constructed using the laminated glass member. For display applications, the above-mentioned window glass or partition may be used as a display. The laminated glass may also be used as a cover glass for various displays, for example, in an in-vehicle display.

The present invention will be explained in more detail with reference to examples, but the present invention is not limited to these examples. The measurement and evaluation methods for each physical property value in the present invention are as follows.

<Amount of Hydroxyl Groups, Degree of Acetylation, Degree of Acetalization>
Measurement of the content (mass%) of ethylene groups bonded to hydroxyl groups 0.4 g of sample was precisely weighed into a 200 mL Erlenmeyer flask with a stopper. After adding 10.0 mL of pyridine-acetic anhydride mixture to the sample, the sample was dissolved in the pyridine-acetic anhydride mixture by heating and ultrasonic irradiation on a water bath at a bath temperature of 90°C. A reflux condenser was attached to the Erlenmeyer flask, and the mixture was heated and refluxed on a water bath for 120 minutes. After the reaction, the cooling tube was washed using 25 mL of pyridine, and the sample solution after the reaction was cooled to room temperature. After cooling, 20 mL of 1,2-dichloroethane was added to the sample solution, and the mixture was shaken, and then 50 mL of water was added, and the mixture was left at room temperature for 30 minutes. Then, the sample solution was subjected to potentiometric titration with 0.5 mol/L (0.5N) sodium hydroxide solution. A blank test was performed in the same manner, except that no sample was used, and the content (mass%) of ethylene groups bonded to hydroxyl groups in the sample was calculated based on the following formula.

In the formula, W _OH is the content of ethylene groups bound to hydroxyl groups (% by mass), V _BL is the amount of sodium hydroxide solution used in the blank test (mL), V _sp is the amount of sodium hydroxide solution used in the sample titration (mL), f _NaOH is the factor of the 0.5 mol/L sodium hydroxide solution actually used in the potentiometric titration, and m is the sample mass (g).

Measurement of the ethylene group content (mass%) to which acetyl groups are bonded 0.4 g of sample was precisely weighed into a 200 mL Erlenmeyer flask with a stopper. After adding 100.0 mL of ethanol to the sample, the sample was dissolved in ethanol by heating and ultrasonic irradiation on a water bath at a bath temperature of 90 ° C. While shaking the Erlenmeyer flask, 10.0 mL of 0.2 mol/L (0.2N) sodium hydroxide was added. A reflux condenser was attached to the Erlenmeyer flask, and the mixture was heated and refluxed in a water bath for 60 minutes. After the reaction, the cooling tube was washed using 25 mL of ethanol, and the sample solution after the reaction was cooled to room temperature. To the cooled sample solution, 10.0 mL of 0.2 mol/L (0.2N) hydrochloric acid was added, shaken well, and left at room temperature for 30 minutes. Then, the sample solution was subjected to potentiometric titration with 0.1 mol/L (0.1N) sodium hydroxide solution. A blank test was performed in the same manner except that no sample was used, and the ethylene group content (mass%) to which acetyl groups are bonded in the sample was calculated based on the following formula.

In the formula, W _Ac is the content (mass%) of ethylene groups bonded to acetyl groups, V _BL is the amount (mL) of sodium hydroxide solution used in the blank test, V _sp is the amount (mL) of sodium hydroxide solution used in the sample titration, f _NaOH is the factor of the 0.1 mol/L sodium hydroxide solution actually used in the potentiometric titration, and m is the sample mass (g).

Measurement of the content (mass%) of ethylene groups bonded to butyral groups From the content (mass%) of ethylene groups bonded to hydroxyl groups and the content (mass%) of ethylene groups bonded to acetyl groups determined by the above-mentioned method, the content (mass%) of ethylene groups bonded to butyral groups was determined based on the following formula.

In the formula, W _Bu is the content (mass %) of ethylene groups bonded to butyral groups, W _OH is the content (mass %) of ethylene groups bonded to hydroxyl groups, and W _Ac is the content (mass %) of ethylene groups bonded to acetyl groups.

- Amount of hydroxyl groups, degree of acetylation, degree of acetalization (degree of butyralization)
The hydroxyl group amount (mol %), the acetylation degree (mol %) and the acetalization degree (mol %) were calculated based on the following formulas using the content of ethylene groups bonded to hydroxyl groups, the content of ethylene groups bonded to acetyl groups and the content of ethylene groups bonded to butyral groups calculated by the above-mentioned methods.

<Thickness change when compressive creep test is performed>
According to the method described in the specification, the thermoplastic resin film of each Example and Comparative Example was cut out to prepare a test sample having a diameter of 8 mm. The thickness change of the prepared test sample was determined according to the method described in the specification.

<Storage modulus>
The thermoplastic resin films obtained in the Examples and Comparative Examples were stored for 12 hours in an environment of room temperature 23±2°C and humidity 25±5%, and the viscoelasticity was measured under the following measurement conditions using a dynamic viscoelasticity device (manufactured by TA Instruments, product name "ARES-G2", jig "diameter 8 mm parallel plate") to detect the shear storage modulus (G') at 90°C.
(Measurement condition)
Deformation mode: shear mode, measurement temperature: -10°C to 100°C, heating rate: 3°C/min, measurement frequency: 1Hz, strain: 1%

<Molecular weight (Mw, Mn)>
The thermoplastic resin membrane used in each Example and Comparative Example was dissolved in an N-methyl-2-pyrrolidone solution to which lithium bromide had been added so as to become 10 mM at a concentration of 0.05% by mass, filtered using a syringe filter (Millex-LH 0.45 μm, manufactured by Merck), and then the molecular weight was measured using gel permeation chromatography (e2690, manufactured by Waters). The number average molecular weight (Mn) and weight average molecular weight (Mw) were calculated using a molecular weight calibration curve prepared using a monodisperse polystyrene standard sample, and the molecular weight distribution (Mw/Mn) was also determined. In addition, a Shodex GPC KF-806L (manufactured by Showa Denko KK) was used as the column, and an N-methyl-2-pyrrolidone solution to which lithium bromide had been added so as to become 10 mM was used as the eluent.

<Appearance of laminated glass>
The appearance of the laminated glass obtained in the Examples and Comparative Examples was evaluated according to the following criteria.
A: Fully transparent B: Includes opaque parts at the edges C: Includes opaque parts throughout the surface

<Appearance after boil test>
The laminated glass obtained in the examples and comparative examples was subjected to a boiling test. The boiling test was performed by boiling the laminated glass in boiling water at 100° C. for 2 hours. The appearance of the laminated glass after the boiling test was evaluated according to the following evaluation criteria.
A: No foaming occurs within 3 mm of the edge. B: Foaming occurs within 10 mm of the edge. C: Foaming occurs over the entire surface (area larger than 10 mm from the edge).

<Functional evaluation>
(Light control film)
When the light control film incorporated in the laminated glass was turned on, if the change (ΔTv) in visible light transmittance (Tv) was 10% or more compared to the case of OFF, it was rated as "A", and if the change (ΔTv) in visible light transmittance (Tv) was less than 10%, it was rated as "C". The visible light transmittance was measured in accordance with JIS R 3212 2015.
(Display Device)
When the power supply of the display device incorporated in the laminated glass was turned on, if it lit up, it was rated as "A", and if it did not lit up, it was rated as "C".

The thermoplastic resins used in the examples and comparative examples were prepared as follows.
(Resin 1)
In a reactor equipped with a stirrer, 1800 ml of ion-exchanged water and 200 g of polyvinyl alcohol A (average polymerization degree 1700, saponification degree 99 mol%) were placed, 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 mass%, and the temperature was adjusted to 15 ° C., and n-butyl aldehyde was added to 10 mol % while stirring. After that, n-butyl aldehyde was added to 60 mol %, and white particulate polyvinyl butyral resin was precipitated. 10 minutes after the precipitation, 30% hydrochloric acid was added so that the hydrochloric acid concentration was 1.8 mass %, and then the temperature was raised to 53 ° C. and the mixture was aged at the aging temperature of 53 ° C. 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 amount 30.3 mol%, acetalization degree 68.5 mol%, acetylation degree 1.2 mol%).

(Resin 2)
Instead of blending 200 g of polyvinyl alcohol A (average polymerization degree 1700, saponification degree 99 mol%), 140 g of polyvinyl alcohol A (average polymerization degree 1700, saponification degree 99 mol%) and 60 g of polyvinyl alcohol B (average polymerization degree 500, saponification degree 99 mol%) were blended. Otherwise, resin 2 (polyvinyl butyral resin, hydroxyl group amount 30.4 mol%, acetalization degree 68.8 mol%, acetylation degree 0.8 mol%) was obtained in the same manner as resin 1.

(Resin 3)
Instead of maturing for 2 hours at an aging temperature of 53° C., maturing was performed for 2 hours at an aging temperature of 63° C. Except for this, the procedure was the same as for Resin 1 to obtain Resin 3 (polyvinyl butyral resin, hydroxyl group amount 30.1 mol %, acetalization degree 69.2 mol %, acetylation degree 0.7 mol %).

The plasticizers used in the examples and comparative examples are as follows.
3GO: Triethylene glycol-di-2-ethylhexanoate DGP: Polyoxypropylene diglyceryl ether, "Unilube DGP-700", NOF Corporation, number average molecular weight 700
PPG: Polypropylene Grigol, "PPG1000", manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., hereinafter referred to as "PPG1000", number average molecular weight is 1000

The light control films and display devices used in the examples and comparative examples were as follows.
Light control 1: SPD film, "LCF-1103DHA30", manufactured by Showa Denko
Light control 2: SPD film, "LCF-1103DHA90", manufactured by Showa Denko
Light control 3: PDLC film, "MIYO Film" manufactured by Kyushu Nanotec Optical Co., Ltd.
Light control 4: PDLC film, "LCMSGIC", manufactured by Toppan Printing Co., Ltd. Display device: Liquid crystal panel, "LS055T1SX01A", manufactured by SHARP Co., Ltd.

<Bonding conditions>
The lamination conditions A and B in each of the examples and comparative examples were as follows.
(Lamination Condition A)
The laminates obtained in each of the Examples and Comparative Examples were placed in a rubber bag, which was a vacuum bag, and degassed for 5 minutes at a vacuum pressure of 0.09 MPa. Next, while still degassed, the laminates were heated to 90° C. at a heating rate of 1° C./min, and held at 90° C. for 30 minutes, and then cooled to 30° C. Next, the pressure was returned to normal to obtain laminated glass.
(Lamination Condition B)
The laminates obtained in each of the Examples and Comparative Examples were placed in a rubber bag, which was a vacuum bag, and degassed for 5 minutes at a vacuum pressure of 0.09 MPa. Next, while still degassed, the laminates were heated to 90°C at a heating rate of 12°C/min, held at 90°C for 5 minutes, and then cooled to 30°C for temporary pressure bonding. The temporarily pressure bonded laminates were pressure bonded for 20 minutes at 140°C and a pressure of 1.3 MPa using an autoclave to obtain laminated glass.

Example 1
A resin composition was obtained by mixing 40 parts by mass of a plasticizer (triethylene glycol-di-2-ethylhexanoate: 3GO) with 100 parts by mass of resin 1. The obtained resin composition was used in a hydraulic press and a spacer having a thickness of 800 μm to produce a thermoplastic resin film having a thickness of 800 μm. In addition, two pieces of 2.5 mm clear glass and the light control film shown in Table 1 were prepared.
Next, a thermoplastic resin film (first thermoplastic resin film), a light control film, and a thermoplastic resin film (second thermoplastic resin film) were laminated in this order on one of the clear glasses, and the other clear glass was further laminated on the thermoplastic resin film to obtain a laminate. The laminate was pressed under lamination condition A to obtain a laminated glass.

(Examples 2 to 4)
The same procedure as in Example 1 was carried out except that the light-control film was changed as shown in Table 1.

(Examples 5 to 7)
The same procedure as in Example 1 was carried out except that the amount and type of plasticizer used were changed as shown in Table 1.

(Examples 8 to 11)
The same procedures as in Examples 1 to 4 were carried out except that the thermoplastic resin used was changed to Resin 2.

(Comparative Examples 1 to 3)
The same procedures as in Examples 1 to 3 were carried out except that the thermoplastic resin used was changed to Resin 3 and the laminate was pressed under lamination condition B.

(Comparative Example 4)
The same procedure as in Example 1 was carried out, except that the thermoplastic resin used was changed to Resin 3.

Example 12
A thermoplastic resin film was produced in the same manner as in Example 1. A sheet of 2.5 mm clear glass and a liquid crystal panel as a display device were prepared. The thermoplastic resin film and the liquid crystal panel were laminated in this order on the clear glass to obtain a laminate. The laminate was pressed under lamination conditions A to obtain a laminated glass.

(Examples 13 to 15)
The same procedure as in Example 12 was carried out except that the amount and type of plasticizer used were changed as shown in Table 1.

(Example 16)
The same procedure as in Example 12 was repeated except that the thermoplastic resin used was changed to Resin 2.

(Comparative Example 5)
The same procedure as in Example 12 was repeated except that the thermoplastic resin used was changed to Resin 3.

(Comparative Example 6)
The same procedure as in Example 12 was carried out except that the thermoplastic resin used was changed to Resin 3 and the laminate was pressed under lamination conditions B.

(Examples 17 to 19)
The same procedure as in Example 1 was repeated, except that the amount and type of resin and the amount of plasticizer used were changed as shown in Table 3, and the second thermoplastic resin film contained the following pigment.
Example 17:
Phthalocyanine pigment (P.B.15-1): Amount that will result in 0.0142% by mass in the resulting resin layer Perylene pigment (P.R.149): Amount that will result in 0.0030% by mass in the resulting resin layer Phthalocyanine pigment (P.G.7): Amount that will result in 0.0015% by mass in the resulting resin layer Carbon black pigment (P.Bk.7): Amount that will result in 0.0300% by mass in the resulting resin layer Example 18:
Phthalocyanine pigment (P.B.15-1): Amount that will result in 0.0148% by mass in the resulting resin layer Perylene pigment (P.R.149): Amount that will result in 0.0054% by mass in the resulting resin layer Phthalocyanine pigment (P.G.7): Amount that will result in 0.0060% by mass in the resulting resin layer Carbon black pigment (P.Bk.7): Amount that will result in 0.0280% by mass in the resulting resin layer Example 19:
Phthalocyanine pigment (P.B.15-1): Amount that will result in 0.0159% by mass in the resulting resin layer Perylene pigment (P.R.149): Amount that will result in 0.0062% by mass in the resulting resin layer Phthalocyanine pigment (P.G.7): Amount that will result in 0.0020% by mass in the resulting resin layer Carbon black pigment (P.Bk.7): Amount that will result in 0.0160% by mass in the resulting resin layer

In the laminated glass of Examples 1 to 19 described above, the laminated glass was produced using a thermoplastic resin film that showed a large change in thickness when compressed in a compression creep test. Therefore, even though the lamination conditions were low temperature and low pressure, no residual air or bubbles were generated, and the laminated glass produced had a good appearance. In addition, the laminated glass also had a good appearance after a boil test, and was able to maintain a good appearance even when used in a high-temperature environment for a long period of time. Furthermore, because lamination was performed at low temperature and low pressure, the light control film and liquid crystal panel were not damaged.
In contrast, in Comparative Examples 1 to 3 and 6, the lamination conditions when producing the laminated glass were high temperature and high pressure, so the light control film or liquid crystal panel was damaged during lamination. Also, in Comparative Examples 4 and 5, the lamination conditions when producing the laminated glass were low temperature and low pressure, so the light control film or liquid crystal panel was not damaged, but the amount of change in thickness when compressed in the compression creep test was small, so residual air and bubbles were generated in the laminated glass, and it was not possible to obtain laminated glass with a good appearance.

10, 20 Laminated glass 11, 12 Laminated glass member 13, 13A, 13B Thermoplastic resin film 14 Functional film

Claims (13)

1. A laminated glass comprising a first laminated glass member, a second laminated glass member, and a thermoplastic resin film (A) disposed between the first and second laminated glass members, wherein the thermoplastic resin film (A) has a thickness change of 80 μm or more when compressed in a compression creep test carried out under the following conditions:
   (Compression creep test conditions)
   A test sample having a diameter of 8 mm and a thickness of 700 to 900 μm made from the thermoplastic resin film (A) is compressed for 5 minutes under conditions of a load of 410 g and 30° C., and then the thickness (T1) of the test sample is measured. Then, while maintaining the load of 410 g, the temperature is increased from 30° C. to 90° C. at a heating rate of 6° C./min. Then, after compressing for 5 minutes under conditions of a load of 410 g and 90° C., the thickness (T2) of the test sample A is measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the test sample is defined as the thickness change amount.
2. The laminated glass according to claim 1, wherein the thermoplastic resin film (A) contains a polyvinyl acetal resin.
3. 3. The laminated glass according to claim 1, wherein the thermoplastic resin film (A) has a storage modulus at 90° C. of 1.4×10 ⁵ Pa or more.
4. The laminated glass according to claim 1 or 2, wherein the weight average molecular weight of the thermoplastic resin film (A) is 230,000 or more and 310,000 or less.
5. The laminated glass according to claim 1 or 2, wherein the molecular weight distribution (Mw/Mn) of the thermoplastic resin film (A) is 2.5 or less.
6. The laminated glass according to claim 1 or 2, comprising a pair of thermoplastic resin films and a functional film disposed between them, the pair of thermoplastic resin films both being the thermoplastic resin film (A).
7. The laminated glass according to claim 1 or 2, wherein at least one of the first laminated glass member and the second laminated glass member is attached with a member constituting a display device.
8. The laminated glass according to claim 7, wherein the display device is a liquid crystal display device.
9. The laminated glass according to claim 1 or 2, wherein the thermoplastic resin film (A) contains a plasticizer.
10. The laminated glass according to claim 9, wherein the plasticizer is at least one selected from the group consisting of triethylene glycol-di-2-ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or derivatives thereof in which some of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups.
11. The laminated glass according to claim 1, which is pressure-bonded at a temperature of 110°C or less.
12. The laminated glass according to claim 1 or 11, which is bonded under pressure conditions of 1.0 MPa or less.
13. A method for producing laminated glass, comprising disposing at least a thermoplastic resin film (A) between a first laminated glass member and a second laminated glass member, and bonding them together by pressure to obtain a laminated glass, comprising the steps of:
    The method for producing laminated glass, wherein the thermoplastic resin film (A) has a thickness change of 80 μm or more when compressed in a compression creep test carried out under the following conditions:
    (Compression creep test conditions)
    A test sample having a diameter of 8 mm and a thickness of 700 to 900 μm made from the thermoplastic resin film (A) is compressed for 5 minutes under conditions of a load of 410 g and 30° C., and then the thickness (T1) of the test sample is measured. Then, while maintaining the load of 410 g, the temperature is increased from 30° C. to 90° C. at a heating rate of 6° C./min. Then, after compressing for 5 minutes under conditions of a load of 410 g and 90° C., the thickness (T2) of the test sample A is measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the test sample is defined as the thickness change amount.

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