Thermoplastic resin film, laminate, and optical laminate

Abstract

The present invention is a thermoplastic resin film having a single-layer structure or a multi-layer structure, the thermoplastic resin film comprising at least a thermoplastic resin layer (A), the thermoplastic resin layer (A) comprising a thermoplastic resin, and when the thermoplastic resin film has a multi-layer structure, at least one outermost layer is the thermoplastic resin layer (A). The amount of change in thickness of the thermoplastic resin layer (A) when compressed by a compression creep test performed under predetermined conditions is 80 [mu] m or more, and the storage modulus of the thermoplastic resin layer (A) at 90 DEG C is 1.4 * 105 Pa or more. A laminate (50) according to the present invention comprises the thermoplastic resin film (10) according to the present invention and a functional layer (40) different from the thermoplastic resin film (10). An optical laminate (1B) according to the present invention is provided with a first transparent substrate (20), a second transparent substrate (30), and the thermoplastic resin film (10) according to the present invention or the laminate (50) according to the present invention. According to the present invention, air residue during crimping can be suppressed without passing through a high-pressure autoclave process under high-temperature and high-pressure conditions. The present invention relates to a thermoplastic resin film which has excellent film-forming properties and which is capable of suppressing foaming of a peripheral portion during pressure bonding, a laminate comprising the thermoplastic resin film, and an optical laminate provided with the thermoplastic resin film or the laminate.

Description

Technical Field

[0001] The present invention relates to a thermoplastic resin film, a laminate including the thermoplastic resin film, and an optical laminate including the thermoplastic resin film or the laminate. Background Art

[0002] Conventionally, laminated glass in which an interlayer film is interposed between two glass plates and integrated is well known. The interlayer film is often formed of a plasticized polyvinyl acetal resin in which a plasticizer is blended. Since laminated glass is safe because even if it is broken by an external impact, the glass fragments are less scattered, it is widely used as window glass for vehicles such as automobiles, aircraft, buildings, and the like.

[0003] Laminated glass is generally manufactured by disposing an interlayer film between two glass plates, and after a pre-degassing process, heating and pressurizing in an autoclave (ACV) process under conditions of a temperature of about 130°C or higher and 140°C or lower and a pressure of about 1.3 MPa to press-bond the glass and the interlayer film.

[0004] In addition, various studies and improvements have been made on the interlayer film for laminated glass. In Patent Document 1, an interlayer film for laminated glass in which the amount of change in thickness during a compression creep test is within a certain range is shown.

[0005] In recent years, there have been demands for imparting various functions to laminated glass. For example, a functional film such as a light control body may be disposed between two glass plates. When a functional film such as a light control body is incorporated into laminated glass, it is known to dispose an interlayer film between the functional film and each glass plate to integrate the two glass plates and the functional film via the interlayer film (for example, refer to Patent Document 2).

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: International Publication No. 2021 / 117596

[0009] Patent Document 2: International Publication No. 2019 / 066042 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] However, functional films such as light control films are not heat-resistant. If a glass plate, an interlayer film, and a functional film are laminated under the conventional high-temperature and high-pressure conditions in an autoclave, problems such as inactivation of the functional film often occur. In addition, there are also problems such as the need to heat to a high temperature and a large amount of carbon dioxide emissions. On the other hand, if the autoclave process is not performed or if it is desired to laminate under low temperature conditions in an autoclave, air may sometimes remain between the interlayer film and the glass plate or between the interlayer film and the functional film during lamination, resulting in poor transparency of the laminated glass obtained by lamination. In addition, if the interlayer film is made soft to suppress the remaining air, there are also problems such as foaming of the peripheral portion of the interlayer film during lamination, resulting in poor appearance or poor film-forming properties of the laminated glass.

[0012] Therefore, an object of the present invention is to provide a thermoplastic resin film having good film-forming properties that can suppress the remaining air during lamination and can suppress foaming of the peripheral portion during lamination even without performing an autoclave process under high-temperature and high-pressure conditions, a laminate including the thermoplastic resin film, and an optical laminate including the thermoplastic resin film or the laminate.

[0013] Means for Solving the Problem

[0014] The inventors of the present invention conducted intensive research and found that by adjusting the thermoplastic resin layer so that the thickness change amount during compression in a specified compression creep test is 80 μm or more and the storage modulus at 90°C is 1.4×10 5 Pa or more, the above problems can be solved by using a thermoplastic resin film using the thermoplastic resin layer, and thus the following present invention was completed. That is, the present invention provides the following [1] to

[25] .

[0015] [1] A thermoplastic resin film having a single-layer structure or a multilayer structure,

[0016] which at least includes a thermoplastic resin layer (A), and the thermoplastic resin layer (A) includes a thermoplastic resin,

[0017] in the case where the thermoplastic resin film has a multilayer structure, at least one outermost layer is the thermoplastic resin layer (A),

[0018] the thickness change amount of the thermoplastic resin layer (A) during compression in a compression creep test performed under the following conditions is 80 μm or more,

[0019] the storage modulus of the thermoplastic resin layer (A) at 90°C is 1.4×10 5 Pa or more.

[0020] (Compression Creep Test Conditions)

[0021] A test sample with a diameter of 8 mm and a thickness of 700 - 900 μm made of the above-mentioned thermoplastic resin layer (A) was compressed for 30 minutes under a load of 410 g and at a temperature of 30 °C, and then the thickness (T1) of the test sample was measured. Then, while maintaining the load of 410 g, the temperature was raised from 30 °C to 90 °C at a rate of 6 °C per minute. Furthermore, after compressing for 5 minutes under a load of 410 g and at a temperature of 90 °C, the thickness (T2) of test sample A was measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the test sample was defined as the above-mentioned thickness change amount.

[0022] [2] For the thermoplastic resin film described in the above [1], the above-mentioned thickness change amount is 400 μm or less.

[0023] [3] For the thermoplastic resin film described in the above [1] or [2], the complex viscosity of the above-mentioned thermoplastic resin layer (A) at 200 °C is 2000 Pa·s or more.

[0024] [4] For the thermoplastic resin film described in any one of the above [1] - [3], the storage modulus of the above-mentioned thermoplastic resin layer (A) at 90 °C is 1.0×10 7 Pa or less.

[0025] [5] For the thermoplastic resin film described in any one of the above [1] - [4], the above-mentioned thermoplastic resin layer (A) contains a polyvinyl acetal resin and a plasticizer.

[0026] [6] For the thermoplastic resin film described in the above [5], the above-mentioned polyvinyl acetal resin is manufactured by a method including a mixing process of mixing polyvinyl alcohol and an aldehyde, and a curing process of curing the mixture obtained in the mixing process. The curing temperature in the above-mentioned curing process is 30 °C or more and 65 °C or less.

[0027] [7] For the thermoplastic resin film described in the above [6], the above-mentioned curing temperature is 40 °C or more and 57 °C or less.

[0028] [8] For the thermoplastic resin film described in any one of the above [5] - [7], the above-mentioned polyvinyl acetal resin is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol with an aldehyde, and the average degree of polymerization of the above-mentioned polyvinyl alcohol is 200 or more and 5000 or less.

[0029] [9] For the thermoplastic resin film described in any one of the above [5] - [8], the weight average molecular weight (Mw) of the above-mentioned polyvinyl acetal resin is 220,000 or more and 310,000 or less.

[0030]

[10] For the thermoplastic resin film according to any one of [5] to [9] above, the content of the plasticizer is 30 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the polyvinyl acetal resin.

[0031]

[11] For the thermoplastic resin film according to any one of [5] to

[10] above, the content of the plasticizer is 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin (a) contained in the thermoplastic resin layer (A).

[0032]

[12] For the thermoplastic resin film according to any one of [5] to

[11] above, the plasticizer is at least 1 kind selected from organic ester plasticizers, organic phosphate plasticizers, organic phosphite plasticizers, polyalkylene glycol-based plasticizers, polyoxyalkylene ether-based plasticizers, and alcohol-based plasticizers.

[0033]

[13] For the thermoplastic resin film according to

[12] above, the plasticizer is at least 1 kind of plasticizer selected from triethylene glycol - bis - 2 - ethylhexanoate (3GO), polypropylene glycol (PPG), and polyoxypropylene diglycerol ether.

[0034]

[14] For the thermoplastic resin film according to any one of [1] to

[13] above, the thickness of the thermoplastic resin layer (A) is 100 μm or more and 2000 μm or less.

[0035]

[15] A laminate comprising the thermoplastic resin film according to any one of [1] to

[14] above and a functional layer different from the thermoplastic resin film.

[0036]

[16] For the laminate according to

[15] above, the functional layer is at least 1 kind of film selected from a dimming film, a display element film, a polarizing film, a retardation film, and an antireflection film.

[0037]

[17] For the laminate according to

[15] or

[16] above, the functional layer includes electronic components.

[0038]

[18] For the laminate according to any one of

[15] to

[17] above, the functional layer is a solar cell element.

[0039]

[19] An optical laminate comprising a first transparent substrate, a second transparent substrate, and the thermoplastic resin film according to any one of [1] to

[14] above disposed between the first transparent substrate and the second transparent substrate.

[0040]

[20] An optical laminate comprising a first transparent substrate, a second transparent substrate, and the laminate according to any one of

[15] to

[19] above disposed between the first transparent substrate and the second transparent substrate.

[0041]

[21] A method for manufacturing an optical laminate, which is a method for manufacturing an optical laminate of the optical laminate described in the above

[19] or

[20] , and obtains an optical laminate by at least disposing a thermoplastic resin film or laminate between the first transparent substrate and the second transparent substrate and pressing and bonding them.

[0042]

[22] According to the method for manufacturing an optical laminate described in the above

[21] , the thermoplastic resin film contains a polyvinyl acetal resin, and the polyvinyl acetal resin is manufactured by a method including a mixing step of mixing the polyvinyl alcohol and the aldehyde, and a curing step of curing the mixture obtained in the mixing step. The curing temperature in the curing step is 30°C or higher and 65°C or lower.

[0043]

[23] According to the method for manufacturing an optical laminate described in the above

[22] , the curing temperature is 40°C or higher and 57°C or lower.

[0044]

[24] According to the method for manufacturing an optical laminate described in any one of the above

[21] to

[23] , an optical laminate is obtained by pressing at a temperature of 110°C or lower.

[0045]

[25] According to the method for manufacturing an optical laminate described in any one of the above

[21] to

[24] , an optical laminate is obtained by pressing under a pressure condition of 1.2 MPa or lower.

[0046] Effects of the Invention

[0047] According to the present invention, it is possible to provide a thermoplastic resin film with good film-forming properties, a laminate including the thermoplastic resin film, and an optical laminate including the thermoplastic resin film or the laminate, which can suppress the remaining air during pressing and suppress the foaming of the peripheral portion during pressing even without going through an autoclave process under high temperature and high pressure conditions. Description of the Drawings

[0048] Figure 1 A diagram showing the layer constitution of the optical laminate in the first embodiment of the present invention.

[0049] Figure 2 A diagram showing the layer constitution of the optical laminate in the second embodiment of the present invention. Detailed Description

[0050] <Thermoplastic Resin Film>

[0051] The thermoplastic resin film of the present invention has a single-layer structure or a multi-layer structure, and at least includes a thermoplastic resin layer (A). The above thermoplastic resin layer (A) contains a thermoplastic resin. When the thermoplastic resin film has a multi-layer structure, at least one outermost layer is the thermoplastic resin layer (A). Furthermore, the thickness change amount of the thermoplastic resin layer (A) when compressed by a compression creep test performed under the following conditions is 80 μm or more, and the storage modulus of the thermoplastic resin layer (A) at 90 °C is 1.4×10 5 Pa or more.

[0052] (Compression creep test)

[0053] First, a test sample with a diameter of 8 mm and a thickness of 700 - 900 μm (for example, 800 μm) is made from the thermoplastic resin layer (A). Next, after the test sample is compressed under the conditions of a load of 410 g and a temperature of 30 °C for 5 minutes, the thickness (T1) of the test sample is measured. Then, while maintaining a load of 410 g, the temperature is raised from 30 °C to 90 °C at a rate of 6 °C per minute. Furthermore, after the test sample is compressed under the conditions of a load of 410 g and a temperature of 90 °C for 5 minutes, 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 defined as the thickness change amount.

[0054] It should be noted that when the thickness of the thermoplastic resin layer (A) is less than 700 μm, the test sample is preferably made by overlapping two or more thermoplastic resin films, appropriately performing hot pressing, etc. to make them bonded, and then adjusting the thickness to 700 - 900 μm by pressing, etc., and then cutting it into a cylindrical shape with a diameter of 8 mm.

[0055] In addition, when the thickness of the thermoplastic resin layer (A) exceeds 900 μm, the test sample is preferably made by adjusting the thickness to 700 - 900 μm by hot pressing, etc. as needed, and then cutting it into a cylindrical shape with a diameter of 8 mm.

[0056] It should be noted that when the thermoplastic resin film has a multi-layer structure, the thermoplastic resin layer (A) is taken out by peeling the thermoplastic resin layer (A) from other layers.

[0057] In addition, when the surface of the test sample has irregularities such as embossing, it is preferable to appropriately adjust the test sample by hot pressing, etc. so that the surface becomes flat, and then cut it into a cylindrical shape with a diameter of 8 mm to make the test sample.

[0058] If the above-mentioned thickness variation of the thermoplastic resin layer (A) is less than 80 μm, when an optical laminate is produced by laminating a thermoplastic resin film with a transparent substrate and a functional layer using an autoclave at a low temperature or means other than an autoclave, air may sometimes remain between the thermoplastic resin film and the transparent substrate or the functional layer, and the transparency of the optical laminate may deteriorate.

[0059] From such a viewpoint, the thickness variation of the thermoplastic resin layer (A) is preferably 90 μm or more, more preferably 120 μm or more, and still more preferably 150 μm or more. If the thickness variation becomes larger in this way, the amount of air remaining during lamination can be further reduced, and the transparency of the optical laminate can be improved.

[0060] The thickness variation of the thermoplastic resin layer (A) is, for example, 500 μm or less, preferably 400 μm or less, more preferably 200 μm or less, and still more preferably 180 μm or less. If the thickness variation is made below a certain value, generation of bubbles at the peripheral portion of the thermoplastic resin film during lamination can be further suppressed.

[0061] [Storage modulus at 90°C]

[0062] The storage modulus of the thermoplastic resin layer (A) at 90°C is 1.4×10 5 Pa or more. If the storage modulus of the thermoplastic resin layer (A) is less than 1.4×10 5 Pa, bubbles may sometimes be generated at the peripheral portion of the thermoplastic resin film during lamination, thereby resulting in poor appearance. In addition, sometimes the flexibility is too high and it is difficult to convey while applying tension, and it is difficult to produce a thermoplastic resin film by extrusion molding, resulting in a decrease in film formability.

[0063] From such a viewpoint, the storage modulus of the thermoplastic resin layer (A) at 90°C is preferably 1.5×10 5 Pa or more, more preferably 1.8×10 5 Pa or more, and still more preferably 2.4×10 5 Pa or more.

[0064] In order to ensure a certain degree of flexibility, the storage modulus at 90°C is preferably below a certain value, for example, 1.0×10 7 Pa or less, preferably 1.0×10 6 Pa or less, and more preferably 3.0×10 5 Pa or less.

[0065] It should be noted that the storage modulus is the shear storage modulus and can be measured under the measurement conditions described in the examples below.

[0066] The amount of thickness change and the storage modulus at 90°C can be appropriately adjusted by the thermoplastic resin used in the thermoplastic resin layer (A) (hereinafter, the thermoplastic resin contained in the thermoplastic resin layer (A) may sometimes be referred to as "thermoplastic resin (a)"). For example, it can be adjusted by the molecular weight of the thermoplastic resin (a). Specifically, if the molecular weight becomes smaller, the amount of thickness change becomes larger. On the other hand, the storage modulus at 90°C tends to become smaller.

[0067] In addition, in the case of using a polyvinyl acetal resin, it can also be adjusted by the manufacturing conditions, etc. during the manufacture of the polyvinyl acetal resin. Specifically, the amount of thickness change and the storage modulus at 90°C can be adjusted by the curing conditions in the curing process performed when manufacturing the polyvinyl acetal resin as described later.

[0068] In addition, it can also be adjusted by the amount, type, etc. of the plasticizer contained in the thermoplastic resin layer (A). For example, if the amount of the plasticizer is increased, the amount of thickness change becomes larger. On the other hand, the storage modulus at 90°C tends to become lower. Further, if 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 prevent the storage modulus at 90°C from becoming lower while making the amount of thickness change large.

[0069] [Complex viscosity]

[0070] The complex viscosity of the thermoplastic resin layer (A) in the thermoplastic resin film of the present invention at 200°C is preferably 2000 Pa·s or more. If the complex viscosity at 200°C is 2000 Pa·s or more, it is easy to apply a certain tension during film formation, the film-forming property is improved, and molding such as extrusion molding is easy to implement. From this point of view, the complex viscosity of the thermoplastic resin layer (A) in the thermoplastic resin film of the present invention at 200°C is more preferably 3000 Pa·s or more, further preferably 4000 Pa·s or more, and even more preferably 5000 Pa·s or more. In addition, from the point of view of preventing the viscosity from being too high and appropriately extruding the thermoplastic resin, the complex viscosity of the thermoplastic resin layer (A) in the thermoplastic resin film of the present invention at 200°C is preferably 30000 Pa·s or less, more preferably 10000 Pa·s or less, and further preferably 7000 Pa·s or less.

[0071] The method for measuring the complex viscosity described above is not particularly limited. For example, it can be measured by the following method. When the thermoplastic resin film is a single-layer structure, the thermoplastic resin film is directly used for the measurement. When the thermoplastic resin film is a multi-layer structure, the thermoplastic resin layer (A) is taken out by peeling the thermoplastic resin layer (A) from other layers. In a mold frame (long 2 cm × wide 2 cm × thick 0.76 mm) disposed between two polyethylene terephthalate (PET) films, 1 g of the thermoplastic resin layer (A) is placed and preheated at a temperature of 150 °C and a pressing pressure of 0 kg / cm 2 for 10 minutes, and then compression molded at 80 kg / cm 2 for 15 minutes. Then, the compression-molded thermoplastic resin layer (A) is disposed in a hydraulic press preset to 20 °C and pressed at 10 MPa for 10 minutes to cool. Next, one PET film is peeled from the mold frame disposed between two PET films, and after being stored in a constant temperature and humidity chamber (humidity 30% (±3%), temperature 23 °C) for 24 hours, the viscoelasticity is measured using an ARES-G2 manufactured by TA INSTRUMENTS in accordance with JIS K7244-10 (ISO 6721-10), and the complex viscosity is measured. As the fixture for viscoelasticity measurement, a parallel plate with a diameter of 8 mm is used. In addition, the viscoelasticity measurement is carried out at a measurement temperature of 200 °C under the conditions of a frequency of 1 Hz and a strain of 5%. The obtained complex viscosity is read as the value of the complex viscosity of the thermoplastic resin layer (A) at 200 °C.

[0072] It should be noted that the complex viscosity of the thermoplastic resin layer (A) can be reduced, for example, by reducing the molecular weight of the thermoplastic resin (a) or increasing the content of the plasticizer contained in the thermoplastic resin layer (A).

[0073] Examples of the thermoplastic resin (a) used as the thermoplastic resin layer (A) of the present invention include (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, isobutene resins, styrene-isoprene copolymer resins, styrene-butadiene copolymer resins, etc. The thermoplastic resins can be used alone or in combination of two or more.

[0074] From the viewpoint of achieving both moisture and heat resistance and impact resistance, among the above, the thermoplastic resin (a) is preferably a polyvinyl acetal resin, a polyurethane resin (PU), an ethylene-vinyl acetate copolymer resin (EVA), a saponified ethylene-vinyl acetate copolymer (EVOH), an ethylene-methacrylic acid copolymer resin, an ionomer resin, an isobutylene resin, a styrene-isoprene copolymer resin, or a styrene-butadiene copolymer resin. Further, among the above, the thermoplastic resin is more preferably a polyvinyl acetal resin. By using a polyvinyl acetal resin, it is easy to achieve excellent impact resistance. In addition, it is easy to achieve good adhesion to various resin materials and inorganic glass. Hereinafter, the polyvinyl acetal resin used as the thermoplastic resin (a) will be described in detail.

[0075] (Polyvinyl acetal resin)

[0076] 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.

[0077] The above aldehyde is not particularly limited. Generally, an aldehyde having 1 to 10 carbon atoms is preferably used. The aldehyde having 1 to 10 carbon atoms is not particularly limited, and examples thereof include n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexanal, n-octanal, n-nonanal, n-decanal, formaldehyde, acetaldehyde, and benzaldehyde. These aldehydes can be used alone or in combination of two or more.

[0078] Among the above, n-butyraldehyde, n-hexanal, and n-valeraldehyde are preferred, and n-butyraldehyde is more preferred. Therefore, the polyvinyl acetal resin is preferably polyvinyl butyral resin.

[0079] Polyvinyl alcohol (PVA) is obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The saponification degree of polyvinyl alcohol is generally 70 to 99.9 mol%.

[0080] The average degree of polymerization of PVA is preferably 200 or more, more preferably 500 or more, further preferably 750 or more, and still more preferably 1000 or more. If the average degree of polymerization is at least the above lower limit, the penetration resistance of the optical laminate becomes high when used in an optical laminate. In addition, the average degree of polymerization of PVA is preferably 5000 or less, more preferably 4000 or less, further preferably 3500 or less, and still more preferably 2500 or less.

[0081] It should be noted that the average degree of polymerization of polyvinyl alcohol is determined by the method according to JIS K6726 "Polyvinyl Alcohol Test Method". In addition, when two or more kinds of polyvinyl alcohol are used as raw materials, the average degree of polymerization of polyvinyl alcohol can be estimated by calculation from the average degree of polymerization of each polyvinyl alcohol.

[0082] In the polyvinyl alcohol that is the raw material of the polyvinyl acetal resin, two or more kinds of polyvinyl alcohol with different average degrees of polymerization can be used. In this case, it is preferable to use the substance obtained by mixing two or more kinds of polyvinyl alcohol as the raw material, and the polyvinyl acetal resin is manufactured by the manufacturing method described later.

[0083] When two or more kinds of polyvinyl alcohol are used, for example, it is preferable to use a first polyvinyl alcohol with an average degree of polymerization of 1500 or more and a second polyvinyl alcohol with an average degree of polymerization of 1000 or less. By using two or more kinds of polyvinyl alcohol with different average degrees of polymerization, it is easy to make the thickness change large.

[0084] 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 further preferably 1600 or more and 2000 or less. In addition, 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 further preferably 400 or more and 850 or less.

[0085] When the first polyvinyl alcohol and the second polyvinyl alcohol are used, the mixing ratio of the first polyvinyl alcohol and the second polyvinyl alcohol is not particularly limited. The mixing amount of the second polyvinyl alcohol is preferably 1% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 40% by mass or less, further preferably 3% by mass or more and 30% by mass or less, and still more preferably 5% by mass or more and 25% by mass or less, based on the total amount of the first polyvinyl alcohol and the second polyvinyl alcohol.

[0086] The amount of hydroxyl groups in the polyvinyl acetal resin is preferably 15 mol% or more, and is preferably 38 mol% or less. By making the amount of hydroxyl groups 15 mol% or more, the adhesiveness is likely to be good, and in the case of use in an optical laminate, the through-resistance of the optical laminate is likely to be good. In addition, by making the amount of hydroxyl groups 38 mol% or less, it is easy to ensure flexibility, and it is possible to prevent the thermoplastic resin film from being too hard or the thickness change amount from becoming low. In addition, by adjusting the amount of hydroxyl groups to the above range, it is easy to adjust the storage modulus to the desired range. Further, by adjusting the amount of hydroxyl groups to the above range, it is possible to further suppress the generation of bubbles in the peripheral portion of the thermoplastic resin film during crimping.

[0087] The above-mentioned hydroxyl group content is more preferably 20 mol% or more, and further preferably 25 mol% or more. In addition, the above-mentioned hydroxyl group content is more preferably 35% or less, and further preferably 33 mol% or less.

[0088] When using polyvinyl butyral resin as the polyvinyl acetal resin, from the same viewpoint, the hydroxyl group content is 15 mol% or more. In addition, it is preferably 38 mol% or less, more preferably 20 mol% or more, further preferably 25 mol% or more, more preferably 35 mol% or less, and further preferably 33 mol% or less.

[0089] The hydroxyl group content of the polyvinyl acetal resin is the value of the molar fraction obtained by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain, expressed as a percentage.

[0090] The amount of ethylene groups to which the above-mentioned hydroxyl groups are bonded can be measured by the procedures described in the examples.

[0091] The acetylation degree of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, further preferably 10 mol% or less, and even more preferably 2 mol% or less. If the above-mentioned acetylation degree is below the above upper limit, the moisture resistance of the polymer film becomes high. In addition, the above-mentioned acetylation degree is not particularly limited, and is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more.

[0092] The above-mentioned acetylation degree is the value of the molar fraction obtained 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 the above-mentioned acetyl groups are bonded can be measured by the procedures described in the examples.

[0093] The acetalization degree of the above-mentioned polyvinyl acetal resin is preferably 47 mol% or more, and preferably 85 mol% or less. The above-mentioned acetalization degree is more preferably 55 mol% or more, further preferably 60 mol% or more. In addition, it is more preferably 80 mol% or less, and further preferably 75 mol% or less.

[0094] It should be noted that the acetalization degree, when the acetal group is a butyral group and the polyvinyl acetal resin (A) is a polyvinyl butyral resin, refers to the butyralization degree.

[0095] The above-mentioned acetalization degree is the value of the molar fraction obtained by dividing the value obtained by subtracting the amount of ethylene groups to which hydroxyl groups are bonded and the amount of ethylene groups to which acetyl groups are bonded from the total amount of ethylene groups in the main chain by the total amount of ethylene groups in the main chain. The acetalization degree (butyralization degree) can be calculated as long as it is based on the amount of ethylene groups to which hydroxyl groups are bonded and the amount of ethylene groups to which acetyl groups are bonded obtained by the procedures described in the examples.

[0096] The polyvinyl acetal resin is preferably an unmodified polyvinyl acetal resin, but it may also be a modified polyvinyl acetal resin.

[0097] 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 the side chain. Examples of the modifying group include a group having a polyoxyalkylene structure in the side chain and a group having an alkyl group (for example, about 2 to 30 carbon atoms) other than an acetal group and an acetyl group in the side chain.

[0098] The modification amount is not particularly limited, for example, it is 0.1 mol% or more and about 10 mol%. It should be noted that the modification amount represents the ratio of the functional group to all vinyl monomer units constituting the polyvinyl acetal resin.

[0099] It should be noted that in the thermoplastic resin layer (A), one kind of polyvinyl acetal resin can be used alone, or two or more kinds can be used in combination.

[0100] When the thermoplastic resin layer (A) uses a polyvinyl acetal resin as the thermoplastic resin (a), as long as the effects of the present invention are exhibited, it may contain a thermoplastic resin other than the polyvinyl acetal resin. The thermoplastic resin other than the polyvinyl acetal resin is as described above.

[0101] However, in the thermoplastic resin layer (A), the polyvinyl acetal resin is preferably the main component. Specifically, the content of the polyvinyl acetal resin is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass based on the total amount of the thermoplastic resin (a) contained in the thermoplastic resin layer (A). Therefore, the thermoplastic resin (a) contained in the thermoplastic resin layer (A) of the present invention may be composed only of the polyvinyl acetal resin.

[0102] The weight average molecular weight (Mw) of the polyvinyl acetal resin is preferably 220,000 or more and 310,000 or less. If the weight average molecular weight (Mw) of the polyvinyl acetal resin is 220,000 or more, the generation of bubbles in the thermoplastic resin film can be further suppressed when using the thermoplastic resin film in a high-temperature environment, and the high-temperature heat resistance of the thermoplastic resin film can be improved. If the weight average molecular weight (Mw) of the polyvinyl acetal resin is 310,000 or less, the flexibility of the thermoplastic resin film can be improved, and the thickness change amount during compression creep can be further increased. From these viewpoints, the weight average molecular weight (Mw) of the polyvinyl acetal resin is more preferably 230,000 or more and 305,000 or less, and further preferably 240,000 or more and 300,000 or less. It should be noted that the weight average molecular weight (Mw) of the polyvinyl acetal resin is measured by gel permeation chromatography.

[0103] (Manufacturing method of polyvinyl acetal resin)

[0104] The polyvinyl acetal resin is preferably manufactured by a manufacturing method including a mixing step of mixing the above-mentioned polyvinyl alcohol and the above-mentioned aldehyde, and a curing step of curing the mixture obtained in the mixing step.

[0105] In the mixing step, it is preferable to mix the polyvinyl alcohol and the aldehyde by a conventional method. In addition, catalysts such as an acid catalyst for promoting the acetalization reaction may be further added in addition to the polyvinyl alcohol and the aldehyde. For example, as long as the aldehyde is added to the mixture in which the acid catalyst is added to the polyvinyl alcohol, it may be added under low-temperature conditions of about 0 to 40 °C.

[0106] In addition, when two or more kinds are used in combination as polyvinyl alcohol (for example, when two or more kinds of polyvinyl alcohol having different molecular weights are used), it is preferable to mix two or more kinds of polyvinyl alcohol with the aldehyde.

[0107] As the above-mentioned curing step, there is no particular limitation. For example, a catalyst such as an acid catalyst is added to the mixture (reaction mixture) obtained by the above-mentioned mixing step, heated until the curing temperature, and preferably maintained at the curing temperature for a certain period of time. In this manufacturing method, acetalization of polyvinyl alcohol proceeds in the mixing step and the curing step, and a polyvinyl acetal resin is obtained.

[0108] The reaction mixture can be neutralized after being maintained at the above-mentioned curing temperature for a certain period of time and appropriately cooled, etc., and then, if necessary, washed with water, dried, etc.

[0109] Examples of the acid catalyst added in the above-mentioned mixing step and curing step include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, and boric acid. In addition, in the curing step, the concentration of the acid catalyst is preferably adjusted to a concentration of, for example, 0.5% by mass or more and 5% by mass or less, more preferably 1% by mass or more and 2.5% by mass or less.

[0110] Regarding the curing temperature in the curing step, it is preferably carried out at a lower temperature, for example, 30 °C or higher and 65 °C or lower, more preferably 35 °C or higher and 60 °C or lower, and still more preferably 40 °C or higher and 57 °C or lower. In addition, the time (curing time) maintained at the above-mentioned curing temperature may be longer than a certain time, for example, 75 minutes or longer and 180 minutes or shorter, preferably 90 minutes or longer and 150 minutes or shorter, and still more preferably 100 minutes or longer and 140 minutes or shorter.

[0111] If the above-mentioned curing temperature and curing time are within the above-mentioned desired ranges, it is presumed that the hydroxyl groups in the polyvinyl acetal resin are likely to be uniformly distributed in the molecule, and thus, the thickness change amount can be increased without significantly reducing the storage modulus at 90 °C.

[0112] Plasticizer

[0113] The thermoplastic resin layer (A) preferably contains a plasticizer. By containing a plasticizer, the thermoplastic resin layer (A) becomes soft, and the adhesiveness of the thermoplastic resin layer (A) to various adherends, the through resistance, etc. can be improved. In addition, it is easy to have a large thickness variation.

[0114] Examples of the plasticizer include organic ester plasticizers, organic phosphorus-based plasticizers such as organic phosphoric acid ester plasticizers and organic phosphite plasticizers, organic ether-based plasticizers such as polyalkylene glycol-based plasticizers, and alcohol-based plasticizers.

[0115] The plasticizer can be used alone as one kind, or two or more kinds can be used in combination. Among the above, organic ester plasticizers and organic ether-based plasticizers are preferred.

[0116] Examples of the preferred organic ester plasticizers include monobasic organic acid esters and polybasic organic acid esters. As the monobasic organic acid ester, an ester formed by a diol and a monobasic organic acid can be cited. As the diol, a polyalkylene glycol in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the number of repetitions of the alkylene unit is 2 to 10, preferably 2 to 4 can be cited. In addition, as the diol, a monoalkylene glycol having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms (i.e., the repeating unit is 1) can also be used.

[0117] Specific examples of the diol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, butylene glycol, etc.

[0118] Examples of the monobasic organic acid include organic acids having 3 to 10 carbon atoms. Specifically, butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptanoic acid, n-octanoic acid, 2-ethylhexanoic acid, n-nonanoic acid, and decanoic acid can be cited.

[0119] Specific examples of the monobasic organic acid include triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dioctanoate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylvalerate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol didecanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, ethylene glycol di-2-ethylbutyrate, 1,2-propylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, 1,2-butylene glycol di-2-ethylbutyrate, etc.

[0120] In addition, as the polybasic organic acid ester, for example, ester compounds formed from dibasic organic acids having 4 to 12 carbon atoms such as adipic acid, sebacic acid, and azelaic acid and alcohols having 4 to 10 carbon atoms can be cited. The alcohol having 4 to 10 carbon atoms can be linear, can have a branched structure, or can have a cyclic structure.

[0121] Specifically, dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, diisononyl adipate, heptyl nonyl adipate, dibutyl carbitol adipate, mixed adipates, etc. can be cited. In addition, it can be oil-modified sebacic alkyd, etc. As the mixed adipate, adipates produced from two or more kinds of alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms can be cited.

[0122] As the organic ester plasticizer, it is not limited to the complete esters of the above-mentioned respective esters, and partial esters can also be used. For example, it can be a partial ester formed from a diol and a monobasic organic acid, or a partial ester formed from a dibasic organic acid and an alcohol. Specifically, triethylene glycol-mono-2-ethylhexanoate, etc. can be cited.

[0123] Furthermore, it can also be a partial ester formed from an alcohol having 3 or more hydroxyl groups such as glycerol and a monobasic organic acid, etc. As the monobasic organic acid, monobasic organic acids having 3 to 24 carbon atoms, preferably 6 to 18 carbon atoms, can be cited. As specific examples of the partial ester formed from an alcohol having 3 or more hydroxyl groups and a monobasic organic acid, mono- or diesters formed from glycerol and stearic acid, mono- or diesters formed from glycerol and 2-ethylhexanoic acid, etc. can be cited.

[0124] Among the above, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferably used as the organic ester plasticizer.

[0125] As the organic phosphorus plasticizer, phosphate esters such as tributoxyethyl phosphate, isodecyl phenyl phosphate, and triisopropyl phosphate can be cited.

[0126] As the polyalkylene glycol plasticizer, polyalkylene oxide compounds having a polyoxyalkylene structure can be cited. Specifically, polyol compounds such as diols, ester compounds formed from diols and monobasic or polybasic organic acids, ether compounds formed from monohydric or polyhydric alcohols and polyoxyalkylene, etc. can be cited. Here, as the diol, polyoxyalkylene glycol, its derivatives, etc. can be cited. As the polyoxyalkylene, polyoxyethylene, polyoxypropylene, polyoxybutylene, their random copolymers or block copolymers, etc. can be cited. The polyalkylene oxide compound can be a polyol compound, an ester compound, an ether compound, or a compound other than these as described above.

[0127] As the polyalkylene oxide compound, polyalkylene oxide or its derivative can be cited. More specifically, polyoxyalkylene glycol formed from the above polyalkylene oxide, ether compounds formed from polyalkylene oxide and polyol, etc. can be cited. All of them may have hydroxyl groups at both ends, or derivatives obtained by substituting part or all of the hydrogen atoms of the terminal hydroxyl groups with alkyl or acyl groups. It should be noted that the number of carbon atoms of the alkyl and acyl groups is not particularly limited, as long as it is about 1 to 8, preferably 1 to 4.

[0128] As the polyoxyalkylene glycol, polyoxyethylene glycol (polyoxyethylene glycol), polypropylene glycol (polyoxypropylene glycol), poly(ethylene oxide / propylene oxide) block copolymer, poly(ethylene oxide / propylene oxide) random copolymer, etc., such as polyoxyethylene polyoxypropylene glycol, polybutylene glycol, etc. can be cited.

[0129] As the ether compound formed from polyalkylene oxide and polyol, ether compounds formed from polyols such as glycerol, diglycerol, trimethylolpropane, erythritol, pentaerythritol, bisphenol A, etc. and polyalkylene oxide can be cited. Specifically, polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, etc. can be cited. In addition, as the derivative obtained by substituting part or all of the hydrogen atoms of the terminal hydroxyl groups with alkyl or acyl groups, derivatives obtained by substituting part or all of the hydrogen atoms of the terminal hydroxyl groups of the above polyoxyalkylene glycol and ether compounds with alkyl or acyl groups can be cited. Specifically, polyoxyethylene glycol monomethyl ether, polyoxyethylene glycol dimethyl ether, polyoxypropylene glycol monomethyl ether, polyoxypropylene glycol dimethyl ether, polyoxyethylene polyoxypropylene glycol monomethyl ether, polyoxyethylene polyoxypropylene glycol dimethyl ether, polyoxyethylene glycol monobutyl ether, polyoxypropylene glycol monobutyl ether, polyoxyethylene polyoxypropylene monobutyl ether, etc. can be cited.

[0130] Among the above, the polyalkylene oxide compound preferably has a polyoxyethylene, polyoxypropylene, polyoxyethylene polyoxypropylene structure, and among them, it more preferably has a polyoxypropylene or polyoxyethylene polyoxypropylene structure. Specifically, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or derivatives obtained by substituting part of the hydrogen atoms of their terminal hydroxyl groups with alkyl groups are preferred.

[0131] As the alcohol-based plasticizer, various polyols such as butanediol, hexanediol, trimethylolpropane, pentaerythritol, etc. can be cited. Among them, trimethylolpropane is preferred.

[0132] The above plasticizers can be used singly or in combination of two or more. Among the above plasticizers, triethylene glycol di-2-ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glycerol ether, polyoxypropylene diglycerol ether, or derivatives obtained by substituting a part of the hydrogen atoms of their terminal hydroxyl groups with alkyl groups are preferred, and triethylene glycol di-2-ethylhexanoate (3GO) is more preferred.

[0133] The content of the plasticizer in the thermoplastic resin layer (A) is not particularly limited, and is preferably 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin (a). If the content of the plasticizer is 10 parts by mass or more, the thermoplastic resin layer (A) becomes moderately soft, and the adhesiveness of the thermoplastic resin layer (A) and the through-resistance of the optical laminate become good. Further, it is also easy to have a large thickness change amount.

[0134] On the other hand, if the content of the plasticizer is 100 parts by mass or less, separation of the plasticizer from the thermoplastic resin layer (A) is prevented. In addition, a decrease in the storage modulus or an excessive thickness change amount can also be prevented.

[0135] The above content of the plasticizer is more preferably 15 parts by mass or more, further preferably 22 parts by mass or more, still more preferably 30 parts by mass or more. In addition, it is more preferably 70 parts by mass or less, further preferably 60 parts by mass or less, and still more preferably 50 parts by mass or less.

[0136] In addition, when the thermoplastic resin layer (A) contains a polyvinyl acetal resin, the content of the plasticizer in the thermoplastic resin layer (A) is preferably 30 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the polyvinyl acetal resin. If the content of the plasticizer is 30 parts by mass or more, the thermoplastic resin layer (A) becomes moderately soft, and the adhesiveness of the thermoplastic resin layer (A) and the through-resistance of the optical laminate become good. Further, it is also easy to have a large thickness change amount.

[0137] On the other hand, if the content of the plasticizer is 50 parts by mass or less, separation of the plasticizer from the thermoplastic resin layer (A) is prevented. In addition, a decrease in the storage modulus or an excessive thickness change amount can also be prevented.

[0138] The above content of the plasticizer is more preferably 30 parts by mass or more. In addition, it is more preferably 45 parts by mass or less, and further preferably 40 parts by mass or less.

[0139] In addition to the plasticizer, the thermoplastic resin layer (A) may appropriately contain known additives used in combination with the thermoplastic resin (a). That is, the thermoplastic resin layer (A) may be composed of a thermoplastic resin (a) such as a polyvinyl acetal resin, or a thermoplastic resin (a) and a plasticizer. However, in addition to these, additives other than the plasticizer that are blended as needed may also be contained.

[0140] Specific examples of the additives other than the plasticizer include ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, adhesion regulators, colorants (pigments or dyes), fluorescent brighteners, crystal nucleating agents, and the like.

[0141] <Colorant>

[0142] The above-mentioned thermoplastic resin layer (A) may or may not contain a colorant. By using the above-mentioned colorant, the laminated glass can be well colored to the desired hue. The above-mentioned colorant may be used alone or in combination of two or more. The above-mentioned thermoplastic resin layer (A) may contain only one kind of colorant, may contain two or more kinds, may contain three or more kinds, may contain ten or less kinds, and may contain five or less kinds.

[0143] Examples of the above-mentioned colorant include pigments and dyes. The above-mentioned colorant may be a pigment, may be a dye, or may be both a pigment and a dye. It should be noted that there are also colorants classified as both pigments and dyes.

[0144] Pigment:

[0145] The above-mentioned colorant may contain a pigment or may be a pigment. The above-mentioned thermoplastic resin layer (A) may or may not contain a pigment. The above-mentioned pigment may be used alone or in combination of two or more. The above-mentioned thermoplastic resin layer (A) may contain only one kind of pigment, may contain two or more kinds, may contain three or more kinds, may contain ten or less kinds, and may contain five or less kinds.

[0146] Examples of the above-mentioned pigment include perylene compounds, indanthrone compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, violanthrone compounds, phthalocyanine compounds, indanthrene compounds, indigo compounds, isoindolinone compounds, nickel coordination compounds, methylene compounds, azomethine compounds, di azine, azo compounds, and carbon black, etc.

[0147] When the above-mentioned thermoplastic resin layer (A) contains a pigment, in 100% by mass of the above-mentioned thermoplastic resin layer (A), the content of the above-mentioned pigment is preferably 0.0001% by mass or more, more preferably 0.01% by mass or more, further preferably 0.02% by mass or more, preferably 0.15% by mass or less, and more preferably 0.12% by mass or less. If the content of the above-mentioned pigment is above the above-mentioned lower limit and below the above-mentioned upper limit, the effects of the present invention can be more effectively exerted.

[0148] Dye:

[0149] The above-mentioned colorant may contain a dye and may be a dye. The above-mentioned thermoplastic resin layer (A) may or may not contain a dye. Only one kind of the above-mentioned dye may be used, or two or more kinds may be used in combination. The above-mentioned thermoplastic resin layer (A) may contain only one kind of dye, may contain two or more kinds, may contain three or more kinds, may contain ten or less kinds, and may contain five or less kinds.

[0150] Examples of the above-mentioned dye include perylene compounds, indanthrene compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, violanthrone compounds, phthalocyanine compounds, indanthrone compounds, indigo compounds, isoindolinone compounds, nickel coordination compounds, methylene compounds, azomethine compounds, di azine and azo compounds, etc.

[0151] When the above-mentioned thermoplastic resin layer (A) contains a dye, in 100% by mass of the above-mentioned thermoplastic resin layer (A), the content of the above-mentioned dye is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, further preferably 0.001% by mass or more, preferably less than 0.015% by mass, and more preferably 0.01% by mass or less. If the content of the above-mentioned dye is above the above-mentioned lower limit and below the above-mentioned upper limit (or less than the above-mentioned upper limit), the effects of the present invention can be more effectively exerted.

[0152] When the above-mentioned thermoplastic resin layer (A) contains a colorant, in 100% by mass of the above-mentioned thermoplastic resin layer (A), the content of the above-mentioned colorant is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, further preferably 0.001% by mass or more, preferably 0.15% by mass or less, and more preferably 0.12% by mass or less. If the content of the above-mentioned colorant is above the above-mentioned lower limit and below the above-mentioned upper limit (or less than the above-mentioned upper limit), the effects of the present invention can be more effectively exerted.

[0153] The thickness of the thermoplastic resin film is not particularly limited. For example, it is 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. By setting the thickness of the thermoplastic resin film to be at least the above lower limit value, the impact resistance can be improved, and the adhesiveness to a transparent substrate or the like can be easily ensured. On the other hand, by setting it to be at most the above upper limit value, the thickness of the optical laminate can be prevented from becoming excessively thick.

[0154] As described above, the thermoplastic resin film of the present invention has a single-layer structure or a multilayer structure. When the thermoplastic resin film of the present invention has a multilayer structure, a part of the layers can be the thermoplastic resin layer (A), or all the layers can be the thermoplastic resin layer (A). In addition, when the thermoplastic resin film has a multilayer structure, as long as any one of the outermost layers is the thermoplastic resin layer (A), but preferably both outermost layers are the thermoplastic resin layer (A). By having both outermost layers as the thermoplastic resin layer (A), it is easy to suppress the remaining air and foaming of the peripheral portion when pressure-bonding to a transparent substrate or the like. On the other hand, in the case of a single-layer structure, it is preferable that the thermoplastic resin film is composed of a single layer of the above thermoplastic resin layer (A).

[0155] For example, in the case of a two-layer structure of the thermoplastic resin film, as long as any one of them is the thermoplastic resin layer (A), but preferably both are the thermoplastic resin layer (A).

[0156] In addition, when the thermoplastic resin film has a three-layer structure including two outermost layers and a middle layer, as long as any one of the two outermost layers is the thermoplastic resin layer (A), but preferably both outermost layers are the thermoplastic resin layer (A). In this case, the middle layer can be composed of the thermoplastic resin layer (A), but it can also be composed of a layer other than the thermoplastic resin layer (A).

[0157] In addition, the thermoplastic resin film can have two outermost layers and two or more middle layers, having a structure of four or more layers. In this case, as long as any one of the two outermost layers is the thermoplastic resin layer (A), but preferably both are the thermoplastic resin layer (A). In addition, each middle layer can be composed of the thermoplastic resin layer (A), but it can also be composed of a layer other than the thermoplastic resin layer (A).

[0158] In addition, when the thermoplastic resin film of the present invention has multiple layers of the thermoplastic resin layer (A), the thermoplastic resin layer (A) can have the same composition or different compositions. For example, among the multiple thermoplastic resin layers (A), the types and contents of the thermoplastic resins constituting them can be the same or different from each other.

[0159] In addition, in the case where the thermoplastic resin film has a layer other than the thermoplastic resin layer (A), such a layer may be a thermoplastic resin layer other than the thermoplastic resin layer (A). The type of the thermoplastic resin used for the thermoplastic resin layer other than the thermoplastic resin layer (A) is not particularly limited, and it may be used by appropriately selecting the types listed as the thermoplastic resin (a) that can be used for the above-mentioned thermoplastic resin layer (A). The types of resins that can be suitably used are the same. Therefore, it is particularly preferable to use a polyvinyl acetal resin.

[0160] In the thermoplastic resin film, the thickness of the thermoplastic resin layer (A) is not particularly limited, and it is preferably a certain proportion or more of the total thickness of the thermoplastic resin film. Specifically, the thickness of the thermoplastic resin layer (A) relative to the total thickness of the thermoplastic resin film may be, for example, a proportion of 0.1 or more and 1 or less, preferably 0.3 or more and 1 or less, more preferably 0.5 or more and 1 or less, and further preferably 0.75 or more and 1 or less. It should be noted that the thickness of the thermoplastic resin layer (A) here refers to the total thickness when the thermoplastic resin layer (A) has two or more layers. By containing the thermoplastic resin layer (A) in a thermoplastic resin film at a thickness ratio of a certain level or more, it is easy to suppress the remaining air during crimping and the foaming of the peripheral part.

[0161] The thickness of each specific thermoplastic resin layer (A) is not particularly limited. For example, it is 50 μm or more and 1500 μm or less, preferably 100 μm or more and 1000 μm or less, and more preferably 200 μm or more and 900 μm or less. By having a certain thickness or more, the thermoplastic resin layer (A) is easy to suppress the remaining air during crimping and the foaming of the peripheral part. In addition, by being a certain thickness or less, it is possible to prevent the thermoplastic resin film from becoming overly thick.

[0162] The manufacturing method of the thermoplastic resin film is not particularly limited, and it may be manufactured by a conventionally known method. For example, it may be manufactured by extrusion molding, press molding, etc., but it is preferably manufactured by extrusion molding.

[0163] In addition, the thermoplastic resin film may have an uneven shape on one or two surfaces. As a method for forming the uneven shape, there is no particular limitation, and examples thereof include a die lip embossing method, an embossing roll method, a calender roll method, etc.

[0164] [Laminate]

[0165] The laminate of the present invention includes the thermoplastic resin film of the present invention and a functional layer different from the thermoplastic resin film of the present invention. By using a thermoplastic resin film having a thermoplastic resin layer (A), when incorporating the functional layer into an optical laminate or the like, there is no need to use an autoclave process under high temperature and high pressure conditions, so inactivation of the functional layer can be suppressed. The functional layer is preferably disposed between a pair of the thermoplastic resin films of the present invention.

[0166] However, the functional layer can also be disposed between the thermoplastic resin film of the present invention and a thermoplastic resin film other than the above-mentioned thermoplastic resin film of the present invention. In addition, the layer constitution of the laminate is not limited to the constitution in which the functional layer is disposed between a pair of thermoplastic resin films, and various schemes can be adopted as described later.

[0167] [Functional layer]

[0168] The functional layer used in the laminate of the present invention is not particularly limited as long as it is a layer having a prescribed function. As the functional layer used in the laminate of the present invention, for example, a functional film can be used. The functional film can be a dimming film, a display element film, or an optical film such as a polarizing film, a retardation film, an antireflection film, etc. In addition, as the functional layer, a solar cell element can also be used.

[0169] In addition, among the above, the functional film is preferably a film having electronic components such as a dimming film and a display element film. If a film having electronic components is integrated by an autoclave under high temperature and high pressure conditions, its function is liable to deteriorate or inactivate. However, according to the present invention, there is no need to press-bond it by an autoclave process under high temperature and high pressure conditions, so the functional layer can be incorporated into an optical laminate or the like without inactivating the functional layer. Therefore, even a film having electronic components can be incorporated into the laminate in a practically usable manner.

[0170] In addition, since a window glass with high added value can be provided if an optical laminate having either a dimming film or a display element film is incorporated into various window glasses, in the present invention, it is desirable to use either of these functional films as the functional layer.

[0171] The dimming film is a film-like member having dimming elements. Specifically, the dimming element is preferably a dimming film having two resin films and a dimming layer disposed between the two resin films. Therefore, the bonding surface of the dimming film with the thermoplastic resin film becomes a resin material, and the bonding strength to the thermoplastic resin film is liable to become high. The resin film used as the dimming element is not particularly limited, and examples thereof include polyester resin films such as PET films and PEN films, (meth)acrylic resin films, TAC films, PES resin films, polyimide resin films, and the like. Among them, from the viewpoints of workability and the like, a polyester resin film is preferred, and a PET film is more preferred. Further, a conductive layer constituting an electrode is provided on the surface of each of the two resin films on the side of the dimming layer.

[0172] The dimming layer changes the visible light transmittance by switching between application and non-application of a voltage between the conductive layers of the two resin films. The dimming layer is constituted by a liquid crystal layer such as a polymer dispersed liquid crystal (PDLC), and the dimming film can be a PDLC film. Further, the dimming film can be an SPD (Suspended Particle Device) film, an electrochromic film, an electrophoretic film device, or the like. Therefore, the dimming layer can be an SPD layer including a resin matrix and a light-adjusting suspension dispersed in the resin matrix, and can be an electrochromic material layer. Further, it can be an electrophoretic layer having electrophoretic particles and a dispersant for dispersing the electrophoretic particles.

[0173] The display element film is a film-like member having a display element. Examples of the display element film include a material having a resin film and a display element mounted on the resin film. The display element film can be a material having a pair of resin films and a display element disposed therebetween. According to such a configuration, when it is disposed between a pair of thermoplastic resin films and incorporated into an optical laminate, it can be bonded to the thermoplastic resin film with high adhesiveness. It should be noted that as the resin film used for the display element film, the resin films listed in the dimming film can be appropriately selected and used.

[0174] Further, in the display element film, a conductive layer constituting an electrode can also be provided on the surface of the resin film on the side of the display element. Examples of the display element include an organic EL element, an LED display, a segment display, and the like, and among them, an organic EL element is preferred. That is, the display element film is preferably an organic EL film.

[0175] It should be noted that the functional film having an electronic component is not limited to the above-mentioned display element film and dimming film, and can be other functional films. Similarly to the display element film and the dimming film, as long as the electronic component is mounted on the resin film, a scheme in which the electronic component is disposed between a pair of resin films is preferred.

[0176] By using a solar cell element in a functional layer, it is possible to provide laminated glass for a building-integrated photovoltaics (BIPV) device.

[0177] The solar cell element is not particularly limited as long as it is a solar cell element used in a building-integrated power generation device (BIPV). Examples thereof include crystalline or thin-film silicon-based solar cell elements; compound semiconductor-based solar cell elements such as CIS, CIGS, CdTe, and GaAs; and organic-based solar cell elements such as dye-sensitized, organic thin-film, and perovskite solar cell elements.

[0178] The laminate can be manufactured by, for example, thermocompression bonding a functional layer and a thermoplastic resin film. In addition, when the laminate is incorporated into an optical laminate, for thermocompression bonding, the functional layer and the thermoplastic resin film can be thermocompression bonded in advance to form a laminate, and then the laminate can be pressure bonded to a transparent substrate to form an optical laminate. Further, in the process of disposing the functional layer and the thermoplastic resin film before bonding between the transparent substrates and pressure bonding the transparent substrate and the thermoplastic resin film, the functional layer and the intermediate film can be pressure bonded together.

[0179] [Optical laminate]

[0180] The optical laminate of the present invention includes a first transparent substrate, a second transparent substrate, and the thermoplastic resin film or the laminate of the present invention disposed between the first transparent substrate and the second transparent substrate.

[0181] [First transparent substrate and second transparent substrate]

[0182] Examples of the first transparent substrate and the second transparent substrate used in the optical laminate of the present invention include glass plates. The glass plate can be either inorganic glass or organic glass, but inorganic glass is preferred. The inorganic glass is not particularly limited, and examples thereof include transparent glass, float glass, tempered glass, colored glass, polished glass, embossed glass, wired glass, wire-embedded glass, ultraviolet-absorbing glass, infrared-reflecting glass, infrared-absorbing glass, and green glass.

[0183] In addition, as the plexiglass, substances generally known as resin glass are used, and examples thereof include polycarbonate plates, (meth)acrylic acid-based plates such as polymethyl methacrylate plates, acrylonitrile styrene copolymer plates, acrylonitrile butadiene styrene copolymer plates, polyester plates such as polyethylene terephthalate plates, fluorine-based resin plates, polyvinyl chloride plates, chlorinated polyvinyl chloride plates, polypropylene plates, polystyrene plates, polysulfone plates, epoxy resin plates, phenolic resin plates, unsaturated polyester resin plates, polyimide resin plates, and various other plexiglass plates. The organic resin plates can be appropriately surface-treated and the like.

[0184] The first transparent substrate and the second transparent substrate can be made of the same material as each other, or can be made of different materials. For example, one can be inorganic glass and the other can be organic glass, but it is preferable that both the first transparent substrate and the second transparent substrate are inorganic glass, or both are organic glass.

[0185] In addition, the thickness of each glass plate used as the first transparent substrate and the second transparent substrate is not particularly limited. For example, it is about 0.1 mm or more and 15 mm or less, preferably 0.5 mm or more and 5 mm or less. The thicknesses of the respective glass plates can be the same as each other or different.

[0186] The transparent substrate can be formed of a single glass plate, or can be a substance in which other members are installed on the glass plate. It is preferable that functional members are installed on the glass plate of the transparent substrate to impart various functions.

[0187] Other members can be, for example, members constituting electronic devices, optical members, etc., but are preferably members constituting a display device. As the display device, it can be a liquid crystal display device, an organic EL display device, an LED display device, a segment display device, etc. Among them, the display device is preferably a liquid crystal display device.

[0188] The display device is preferably a display panel in which a glass plate is used as a substrate and a display layer such as a liquid crystal layer or an organic EL layer, a light-emitting element, etc. are provided on the substrate, but it is preferable to use the glass plate that is the substrate of the display panel as the transparent substrate.

[0189] In addition, sometimes functional films, conductive layers constituting electrodes, sensors, etc., antireflection layers, hard coats, and other functional layers are laminated on the glass plate, and the transparent substrate can be a glass plate on which such functional films and functional layers are laminated.

[0190] Therefore, the bonding surface with the thermoplastic resin film to which the thermoplastic resin film is directly laminated can be the glass plate itself, or can be the surface of the functional film or the functional layer.

[0191] When two or more thermoplastic resin films are provided in the laminate, as described above, it is preferable that all the thermoplastic resin films are the thermoplastic resin films of the present invention, but a part of the thermoplastic resin films may be films other than the thermoplastic resin films of the present invention. In addition, other layers such as an adhesive layer may be appropriately provided between the functional layer and the thermoplastic resin film.

[0192] [Layer structure of the optical laminate]

[0193] Next, the layer structure of the optical laminate will be described in detail with reference to the accompanying drawings and embodiments. As Figure 1 shown, in the first embodiment of the present invention, the optical laminate 1A is an optical laminate in which one thermoplastic resin film (thermoplastic resin layer (A)) 10 is provided between a first transparent substrate 20 and a second transparent substrate 30. In the optical laminate 1A, the thermoplastic resin film 10 is bonded to both the first transparent substrate 20 and the second transparent substrate 30 to join them.

[0194] In the first embodiment, it is preferable that at least one of the first transparent substrate 20 and the second transparent substrate 30 is provided with other members as described above. Specifically, functional members constituting electronic devices such as display devices, optical members, etc. may be installed, or the above-mentioned functional films, functional layers, etc. may be laminated.

[0195] Among them, it is preferable that at least one of the first transparent substrate 20 and the second transparent substrate 30 is provided with a member constituting a display device, particularly a liquid crystal display device. That is, it is preferable that at least one of the first transparent substrate 20 and the second transparent substrate 30 is a glass plate constituting a display device, and it is preferable that a display device having at least one of the first transparent substrate 20 and the second transparent substrate 30 as a substrate is provided in the optical laminate 1A.

[0196] In the first embodiment, by using a substance containing the above-mentioned thermoplastic resin layer (A) as the thermoplastic resin film 10, even if the first transparent substrate 20, the second transparent substrate 30, and the thermoplastic resin film 10 are integrated without going through the autoclave process under high temperature and high pressure conditions, it is possible to suppress appearance defects and reduction in transparency caused by residual air and foaming. On the other hand, even if a functional member is provided in either the first transparent substrate 20 or the second transparent substrate 30, it is possible to perform press bonding and integration without going through the autoclave process under high temperature and high pressure conditions, so that the functional member installed in the optical laminate 1A can be prevented from deteriorating or deactivating.

[0197] In addition, as another preferred embodiment, a plurality of thermoplastic resin films may also be provided between the first transparent substrate and the second transparent substrate in the optical laminate. When a plurality of thermoplastic resin films are provided, each thermoplastic resin film is preferably the thermoplastic resin film of the present invention having the thermoplastic resin layer (A) described above. When a plurality of thermoplastic resin films are provided, by making all the thermoplastic resin films the above-mentioned thermoplastic resin films, even without passing through the autoclave process under high temperature and high pressure conditions to integrate the first transparent substrate, the second transparent substrate, and the thermoplastic resin film, appearance defects caused by residual air and foaming can be suppressed.

[0198] One embodiment of the optical laminate in the case where a plurality of thermoplastic resin films are provided in the laminate is shown as the second embodiment in Figure 2 as follows. As Figure 2 shown, in the optical laminate 1B according to the second embodiment, a pair of thermoplastic resin films 10 are provided between the first transparent substrate 20 and the second transparent substrate 30, and a functional layer 40 is further provided between the pair of thermoplastic resin films 10. That is, in the optical laminate 1B according to the second embodiment, a laminate 50 in which the functional layer 40 is provided between the pair of thermoplastic resin films 10 is provided between the first transparent substrate 20 and the second transparent substrate 30. It is preferable that both of the pair of thermoplastic resin films 10 are the above-mentioned thermoplastic resin films of the present invention.

[0199] In the optical laminate 1B, one thermoplastic resin film 10 is bonded to both the first transparent substrate 20 and the functional layer 40 to join them, and the other thermoplastic resin film 10 is bonded to both the second transparent substrate 30 and the functional layer 40 to join them. Thus, the first transparent substrate 20 and the second transparent substrate 30 are integrated with the functional layer 40 through the thermoplastic resin film 10.

[0200] In the second embodiment, the optical laminate 1B may also be integrated through the autoclave process under high temperature and high pressure conditions, but even without passing through the autoclave process under high temperature and high pressure conditions, by using the thermoplastic resin film 10 having the thermoplastic resin layer (A), appearance defects caused by residual air and foaming can be prevented. In addition, by integrating the optical laminate 1B at a low temperature, deterioration or inactivation of the functional layer 40 can also be prevented.

[0201] It should be noted that in the second embodiment, a scheme of providing 2 thermoplastic resin films 10 and 1 functional layer in the laminate is shown, but 3 or more thermoplastic resin films and 2 or more functional layers may also be provided in the laminate. In this case, it is preferable that the thermoplastic resin films and the functional layers are alternately arranged. Further, it is preferable that thermoplastic resin films are arranged at the positions closest to the first transparent substrate and the second transparent substrate.

[0202] For example, in the case where three thermoplastic resin films 10 are provided and two functional layers are provided, it is preferable to arrange them in the order of the first transparent substrate / thermoplastic resin film / functional layer / thermoplastic resin film / functional layer / thermoplastic resin film / second transparent substrate.

[0203] In addition, in the case where three or more thermoplastic resin films are provided, it is only necessary to use the above-mentioned thermoplastic resin film having the thermoplastic resin layer (A) as each thermoplastic resin film.

[0204] It should be noted that in the optical laminate, when a plurality of thermoplastic resin films are provided, the constitution of each thermoplastic resin film may be the same or different.

[0205] <Manufacturing method of optical laminate>

[0206] The optical laminate of the present invention is preferably manufactured by a manufacturing method of obtaining an optical laminate by at least arranging a thermoplastic resin film or a laminate between a first transparent substrate and a second transparent substrate and crimping them to bond them. In addition, it is also possible to prepare members constituting the laminate, arrange the members constituting the laminate between the first transparent substrate and the second transparent substrate, and crimp and bond them to produce an optical laminate incorporating the laminate.

[0207] In the above manufacturing method, first, a first transparent substrate, a second transparent substrate, and members (thermoplastic resin film or laminate) arranged between the first transparent substrate and the second transparent substrate are prepared.

[0208] Here, the laminate arranged between the first transparent substrate and the second transparent substrate may be appropriately selected according to the structure of the obtained optical laminate. For example, in the first embodiment, it is only necessary to prepare a single thermoplastic resin film. In addition, for example, in the second embodiment, it is only necessary to prepare a laminate composed of two thermoplastic resin films and one functional layer.

[0209] In addition, as described above, in the optical laminate, a functional member may sometimes be installed on at least one of the first transparent substrate and the second transparent substrate, but it is preferable that the functional member is installed on the transparent substrate before being integrated with the optical laminate. Therefore, in the above manufacturing method, at least one of the first transparent substrate and the second transparent substrate may be prepared as a transparent substrate on which a functional member is installed. For example, as described above, in the case where the transparent substrate constitutes the substrate of a display device, at least one of the first transparent substrate and the second transparent substrate may be prepared as a display device.

[0210] In this manufacturing method, it is preferable to obtain an optical laminate by disposing a thermoplastic resin film or laminate between a first transparent substrate and a second transparent substrate and laminating them to integrate them. In addition, it is also possible to dispose the components constituting the laminate between the first transparent substrate and the second transparent substrate, laminate them to integrate them, and obtain an optical laminate incorporating the laminate. Here, the thermoplastic resin film or laminate may be disposed according to the layer constitution of the obtained optical laminate. For example, in the second embodiment, it may be disposed between the first transparent substrate and the second transparent substrate in the order of a thermoplastic resin film, a functional layer, and a thermoplastic resin film.

[0211] The above lamination can be performed by a vacuum bag, by an autoclave under low-temperature conditions, or by a stamping machine other than these. Among them, it is preferably performed by a vacuum bag. In addition, before performing the above lamination, temporary crimping can be performed using a rubber roller or the like.

[0212] In this manufacturing method, it is necessary to perform the above lamination under low-temperature conditions. Specifically, it is preferable to perform crimping at a temperature of 110°C or lower. In addition, the above lamination is preferably performed under low temperature and low pressure. Specifically, it is preferably performed at a temperature of 110°C or lower and a pressure of 1.0 MPa or lower. In this way, by performing lamination under low-temperature and low-pressure conditions, it is possible to prevent deterioration or inactivation of the functional layer and the functional components (for example, display devices) mounted on the first transparent substrate and the second transparent substrate.

[0213] From the viewpoint of more surely preventing deterioration and inactivation of the functional components, the temperature during lamination is preferably 100°C or lower. From the viewpoint of preventing the generation and foaming of residual air, it is preferably 60°C or higher, and more preferably 70°C or higher.

[0214] In addition, from the viewpoint of more surely preventing deterioration and inactivation of the functional components, the pressure during lamination is preferably 1.2 MPa or lower. In addition, in the case of performing under negative pressure as in the case of using a vacuum bag, for example, it may be 0.095 MPa or lower, preferably 0.08 MPa or lower, and preferably 0.06 MPa or lower.

[0215] Regarding the lower limit value of the pressure during lamination, there is no particular limitation. For example, in the case of performing under pressure such as an autoclave, it is preferably 0.5 MPa or higher, and more preferably 0.7 MPa or higher. In addition, in the case of performing under negative pressure as in the case of using a vacuum bag, it is preferably 0.001 MPa or higher, and more preferably 0.005 MPa or higher.

[0216] In addition, the time for performing lamination under the above temperature and pressure is not particularly limited. For example, it is 5 to 120 minutes, and preferably 10 to 60 minutes.

[0217] The optical laminate of the present invention is not particularly limited and can be used for various purposes, and can be suitably used as laminated glass. The optical laminate of the present invention is used, for example, in various transportation means such as automobiles, trams, ships, airplanes, etc., or various buildings such as buildings, apartments, single-family houses, halls, gymnasiums, etc., or window glasses of machine tools such as cutting and grinding machines, construction machinery such as excavators and cranes, etc., partitions inside various transportation means and various buildings, etc. Among them, vehicle uses such as automobiles are preferred, and it is preferably used for vehicle window glasses.

[0218] In addition, when the optical laminate of the present invention constitutes a display device through a transparent substrate, for example, it is preferably used for various display purposes. As a display purpose, the above-mentioned window glass and partition can be used as a display.

[0219] In addition, the optical laminate can be used as a cover glass for various displays, etc. For example, it can be applied to in-vehicle displays, etc.

[0220] Examples

[0221] The present invention will be further described in detail by way of examples, but the present invention is not limited by any of these examples. It should be noted that the measurement methods and evaluation methods of each physical property value in the present invention are as described below.

[0222] <Amount of hydroxyl group, degree of acetylation, degree of acetalization>

[0223] ·Determination of the content (mass%) of ethylene group bonded to hydroxyl group

[0224] 0.4 g of the sample was precisely weighed into a 200 mL stoppered conical flask. After adding 10.0 mL of a pyridine-acetic anhydride mixed solution to the sample, the sample was dissolved in the pyridine-acetic anhydride mixed solution by heating in a water bath at a bath temperature of 90 °C and irradiating ultrasonic waves. A reflux condenser was installed on the conical flask, and it was heated under reflux in the water bath for 120 minutes. After the reaction, 25 mL of pyridine was used to wash the condenser, and the reaction sample solution was cooled to room temperature. 20 mL of 1,2-dichloroethane was added to the cooled sample solution, and after shaking, 50 mL of water was further added, shaken, and left at room temperature for 30 minutes. Then, the sample solution was subjected to potentiometric titration with a 0.5 mol / L (0.5N) sodium hydroxide solution. A blank test was carried out in the same manner except that the sample was not used, and the content (mass%) of the ethylene group bonded to the hydroxyl group in the sample was calculated based on the following formula.

[0225] [Equation 1]

[0226]

[0227] In the formula, WOH is the content of hydroxy-bound ethylene (% 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 0.5 mol / L sodium hydroxide solution actually used in the potentiometric titration, and m is the sample mass (g).

[0228] · Determination of the content of acetoxy-bound ethylene (% by mass)

[0229] Precisely weigh 0.4 g of the sample into a 200 mL stoppered conical flask. After adding 100.0 mL of ethanol to the sample, heat it on a water bath at a bath temperature of 90 °C and irradiate with ultrasonic waves to dissolve the sample in ethanol. While shaking the conical flask, add 10.0 mL of 0.2 mol / L (0.2 N) sodium hydroxide. Install a reflux condenser on the conical flask and heat it under reflux in the water bath for 60 minutes. After the reaction, wash the condenser with 25 mL of ethanol and cool the sample solution after the reaction to room temperature. Add 10.0 mL of 0.2 mol / L (0.2 N) hydrochloric acid to the cooled sample solution, shake well, and let it stand at room temperature for 30 minutes. Then, perform potentiometric titration of the sample solution with 0.1 mol / L (0.1 N) sodium hydroxide solution. Conduct a blank test in the same manner except without using the sample, and calculate the content of acetoxy-bound ethylene (% by mass) in the sample based on the following formula.

[0230] [Formula 2]

[0231]

[0232] In the formula, W Ac is the content of acetoxy-bound ethylene (% 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 0.1 mol / L sodium hydroxide solution actually used in the potentiometric titration, and m is the sample mass (g).

[0233] · Determination of the content of butyraldehyde group-bound ethylene (% by mass)

[0234] Based on the content of hydroxy-bound ethylene (% by mass) and the content of acetoxy-bound ethylene (% by mass) determined by the above method, calculate the content of butyraldehyde group-bound ethylene (% by mass) based on the following formula.

[0235] [Formula 3]

[0236] WBu = 100 - (WOH + WAc)

[0237] In the formula, W Bu is the content of ethylene groups bonded to butyral groups (mass %), W OH is the content of ethylene groups bonded to hydroxyl groups (mass %), W Ac is the content of ethylene groups bonded to acetyl groups (mass %).

[0238] · Amount of hydroxyl groups, degree of acetylation, degree of acetalization (degree of butyralization)

[0239] 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 obtained by the above method, the amount of hydroxyl groups (mol %), the degree of acetylation (mol %), and the degree of acetalization (mol %) were calculated based on the following formulas.

[0240] [Equation 4]

[0241]

[0242] [Equation 5]

[0243]

[0244] [Equation 6]

[0245]

[0246] <Amount of thickness change when compression creep test was performed>

[0247] According to the method described in the specification, test samples with a diameter of 8 mm were prepared by cutting out the thermoplastic resin films of each example and comparative example. Using the prepared test samples, the amount of thickness change was determined according to the method described in the specification.

[0248] <Storage modulus>

[0249] The thermoplastic resin films obtained in the examples and comparative examples were stored in an environment of 23 ± 2°C at room temperature and 25 ± 5% humidity for 12 hours. Using a dynamic viscoelasticity device (manufactured by TA Instruments, trade name “ARES - G2”, fixture “parallel plates with a diameter of 8 mm”), the viscoelasticity was measured under the following measurement conditions, and the shear storage modulus (G’) at 90°C was detected.

[0250] (Measurement conditions)

[0251] Deformation mode: Shear mode, measurement temperature: -20°C or higher and 100°C or lower, heating rate: 3°C / minute, measurement frequency: 1 Hz, strain: 1%

[0252] Deformation method: Shearing mode, Measurement temperature: Above 100°C and below 200°C, Heating rate: 3°C / minute, Measurement frequency: 1 Hz, Strain: 5%

[0253] <Complex viscosity at <200°C>>

[0254] According to the method described in the instruction manual, the complex viscosity at 200°C of each example and each comparative example was measured.

[0255] <Film formability>

[0256] Using HAAKE PolyLab OS RheoDrive 16 and Reomex OS (both manufactured by Thermo scientific), 100 parts by mass of a thermoplastic resin and 40 parts by mass of a plasticizer (triethylene glycol - bis-2-ethylhexanoate: 3GO) were kneaded while being heated to 200°C, and the resulting resin composition was extruded in a sheet form to obtain a thermoplastic resin film with a thickness of 0.76 mm. The film formability was evaluated in 3 grades based on this.

[0257] A: ······ Film formability is normal

[0258] B: ······ Film can be formed

[0259] C: ······ There are abnormalities in film formation or appearance

[0260] <Peripheral foaming>

[0261] The glass obtained in the examples was left standing on a light-shielding curtain, and the transparency of the optical laminate was observed visually, and it was evaluated in 3 grades according to the amount of air remaining.

[0262] A: ······ No peripheral foaming

[0263] B: ······ There is some peripheral foaming

[0264] C: ······ There is a large amount of peripheral foaming

[0265] <Residual air after lamination>

[0266] The glass obtained in the examples was left standing on a light-shielding curtain, and the transparency of the optical laminate was observed visually, and it was evaluated in 3 grades according to the amount of air remaining.

[0267] A: ······ No air remains

[0268] B: ······ There is some air remaining

[0269] C: ······ There is a large amount of air remaining

[0270] The thermoplastic resins used in the examples and comparative examples were prepared as described below.

[0271] (Resin 1)

[0272] In a reactor equipped with a stirring device, 1800 mL of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) were added, and they were heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Next, in this solution, 30% hydrochloric acid as a catalyst was added so that the hydrochloric acid concentration became 0.2% by mass. After adjusting the temperature to 15°C, n-butyraldehyde was added with stirring so that it became 10 mol%. Then, n-butyraldehyde was added so that it became 60 mol%, and as a result, white particulate polyvinyl butyral resin precipitated. Ten minutes after the precipitation, 30% hydrochloric acid was added so that the hydrochloric acid concentration became 1.8% by mass, and then the temperature was raised to 53°C and it was cured at a curing temperature of 53°C for 2 hours.

[0273] Next, the solution was cooled, neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 1 (polyvinyl butyral resin, hydroxyl amount 30.8 mol%, acetalization degree 68.4 mol%, acetylation degree 0.8 mol%, calculated degree of polymerization 1700).

[0274] (Resin 2)

[0275] Instead of blending 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%), 180 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) and 20 g of polyvinyl alcohol B (average degree of polymerization 500, saponification degree 99 mol%) were blended. Otherwise, the same operations as those for Resin 1 were carried out to obtain Resin 2 (polyvinyl butyral resin, hydroxyl amount 30.6 mol%, acetalization degree 68.5 mol%, acetylation degree 0.8 mol%, calculated degree of polymerization 1500).

[0276] (Resin 3)

[0277] Instead of blending 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%), 160 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) and 40 g of polyvinyl alcohol B (average degree of polymerization 500, saponification degree 99 mol%) were blended. Otherwise, the same operations as those for Resin 1 were carried out to obtain Resin 3 (polyvinyl butyral resin, hydroxyl amount 31.4 mol%, acetalization degree 67.7 mol%, acetylation degree 0.9 mol%, calculated degree of polymerization 1350).

[0278] (Resin 4)

[0279] Instead of blending 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%), 140 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) and 60 g of polyvinyl alcohol B (average degree of polymerization 500, saponification degree 99 mol%) were blended. Other than this, the operation was the same as that for Resin 1, and Resin 4 (polyvinyl butyral resin, hydroxyl group amount 30.4 mol%, acetalization degree 68.8 mol%, acetylation degree 0.8 mol%, calculated degree of polymerization 1150) was obtained.

[0280] (Resin 5)

[0281] Instead of curing for 2 hours at a curing temperature of 53°C, curing was carried out for 2 hours at a curing temperature of 63°C. Other than this, the operation was the same as that for Resin 1, and Resin 5 (polyvinyl butyral resin, hydroxyl group amount 30.4 mol%, acetalization degree 68.8 mol%, acetylation degree 0.8 mol%, calculated degree of polymerization 1700) was obtained.

[0282] (Resin 6)

[0283] Instead of blending 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%), 50 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) and 150 g of polyvinyl alcohol B (average degree of polymerization 500, saponification degree 99 mol%) were blended. Further, instead of curing for 2 hours at a curing temperature of 53°C, curing was carried out for 2 hours at a curing temperature of 47°C. Other than this, the operation was the same as that for Resin 1, and Resin 6 (polyvinyl butyral resin, hydroxyl group amount 30.3 mol%, acetalization degree 68.8 mol%, acetylation degree 0.9 mol%, calculated degree of polymerization 850) was obtained.

[0284] The plasticizers used in the examples and comparative examples are as described below.

[0285] 3GO: Triethylene glycol - bis - 2 - ethylhexanoate

[0286] (Example 1)

[0287] 40 parts by mass of a plasticizer (triethylene glycol - bis - 2 - ethylhexanoate: 3GO) was mixed with respect to 100 parts by mass of Resin 1 to obtain a resin composition. Using the obtained resin composition, a film - shaped thermoplastic resin film with a thickness of 800 μm was produced using a hydraulic press and a spacer with a thickness of 800 μm. Further, two pieces of transparent glass with a thickness of 2.5 mm were prepared.

[0288] Next, a thermoplastic resin film was superposed on a transparent glass, and another transparent glass was further superposed on the thermoplastic resin film to obtain a laminate. The obtained laminate was placed in a rubber bag as a vacuum bag and degassed at a vacuum degree of 0.09 MPa for 5 minutes. Next, in the degassed state, the laminate was heated by raising the temperature at a rate of 1 °C per minute until 90 °C, held at 90 °C for 30 minutes for formal crimping, and then cooled until 30 °C. Next, the normal pressure was restored to obtain the optical laminate of Example 1.

[0289] (Examples 2 to 5 and Comparative Examples 1 to 7)

[0290] The amount and type of the resin used and the amount of the plasticizer were changed as described in Table 1, and otherwise, the same procedures as in Example 1 were carried out.

[0291] [Table 1]

[0292]

[0293] (Examples 6 to 8)

[0294] The amount and type of the resin used and the amount of the plasticizer were changed as described in Table 2, and further contained the following pigments, and otherwise, the same procedures as in Example 1 were carried out.

[0295] Example 6:

[0296] Phthalocyanine pigment (P.B.15-1): an amount of 0.0142% by mass in the obtained resin layer

[0297] Perylene pigment (P.R.149): an amount of 0.0030% by mass in the obtained resin layer

[0298] Phthalocyanine pigment (P.G.7): an amount of 0.0015% by mass in the obtained resin layer

[0299] Carbon black pigment (P.Bk.7): an amount of 0.0300% by mass in the obtained resin layer

[0300] Example 7:

[0301] Phthalocyanine pigment (P.B.15-1): an amount of 0.0148% by mass in the obtained resin layer

[0302] Perylene pigment (P.R.149): an amount of 0.0054% by mass in the obtained resin layer

[0303] Phthalocyanine pigment (P.G.7): an amount of 0.0060% by mass in the obtained resin layer

[0304] Carbon black-based pigment (P.Bk.7): In the resulting resin layer, it is in an amount of 0.0280% by mass

[0305] Example 8:

[0306] Phthalocyanine-based pigment (P.B.15-1): In the resulting resin layer, it is in an amount of 0.0159% by mass

[0307] Perylene-based pigment (P.R.149): In the resulting resin layer, it is in an amount of 0.0062% by mass

[0308] Phthalocyanine-based pigment (P.G.7): In the resulting resin layer, it is in an amount of 0.0020% by mass

[0309] Carbon black-based pigment (P.Bk.7): In the resulting resin layer, it is in an amount of 0.0160% by mass

[0310] [Table 2]

[0311]

[0312] The optical laminates of Examples 1 to 8 above were produced using a thermoplastic resin film having a thickness change amount of 80 μm or more and a storage modulus at 90°C of 1.4×10 5 Pa or more when compressed by a compression creep test. As a result, even when the lamination conditions are low temperature and low pressure, the residual amount of air during lamination is small, and the transparency of the optical laminate is high. In addition, almost no foaming occurs in the peripheral portion of the thermoplastic resin film. Further, the film-forming property of the thermoplastic resin film is good.

[0313] In contrast, for the optical laminates of Comparative Examples 1 to 3, 5, and 6, since the thickness change amount of the thermoplastic resin film used when compressed by a compression creep test is less than 80 μm, there is a large amount of residual air during lamination. As a result, the transparency of the optical laminate is poor. In addition, for the optical laminates of Comparative Examples 4 and 7, since the storage modulus at 90°C of the thermoplastic resin film used is less than 1.4×10 5 Pa, a large amount of bubbles are generated in the peripheral portion of the thermoplastic resin film. In addition, it is difficult to produce the thermoplastic resin film by extrusion molding.

[0314] Explanation of symbols

[0315] 1A, 2B Optical laminate

[0316] 10 Thermoplastic resin film (thermoplastic resin layer (A))

[0317] 20 First transparent substrate

[0318] 30 Second transparent substrate

[0319] 40 Functional layer

[0320] 50 Laminate

Claims

1. A thermoplastic resin film having a single-layer structure or a multilayer structure, which at least comprises a thermoplastic resin layer (A), and the thermoplastic resin layer (A) contains a thermoplastic resin, when the thermoplastic resin film has a multilayer structure, at least one outermost layer is the thermoplastic resin layer (A), the thickness change amount of the thermoplastic resin layer (A) when compressed by a compression creep test carried out under the following conditions is 80 μm or more, The storage modulus of the thermoplastic resin layer (A) at 90 °C is 1.4×10 5 Pa or more, the compression creep test conditions are: After a test sample with a diameter of 8 mm and a thickness of 700 - 900 μm made of the thermoplastic resin layer (A) is compressed for 30 minutes under a load of 410 g and at a temperature of 30°C, the thickness T1 of the test sample is measured; then, while maintaining the load of 410 g, the temperature is raised from 30°C to 90°C at a rate of 6°C per minute; further, after being compressed for 5 minutes under a load of 410 g and at a temperature of 90°C, the thickness T2 of test sample A is measured; the absolute value of the difference between the thickness T1 and the thickness T2 of the test sample is set as the thickness change amount.

2. The thermoplastic resin film according to claim 1, wherein the complex viscosity of the thermoplastic resin layer (A) at 200°C is 2000 Pa·s or more.

3. The thermoplastic resin film according to claim 1 or 2, wherein the thermoplastic resin layer (A) contains a polyvinyl acetal resin and a plasticizer.

4. The thermoplastic resin film according to claim 3, wherein the content of the plasticizer is 30 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the polyvinyl acetal resin.

5. The thermoplastic resin film according to claim 3 or 4, wherein the plasticizer is at least one plasticizer selected from triethylene glycol - bis - 2 - ethylhexanoate (3GO), polypropylene glycol (PPG), and polyoxypropylene diglycerol ether (DGP).

6. A laminate comprising the thermoplastic resin film according to any one of claims 1 - 5 and a functional layer different from the thermoplastic resin film.

7. An optical laminate comprising a first transparent substrate, a second transparent substrate, and the thermoplastic resin film according to any one of claims 1 - 5 disposed between the first transparent substrate and the second transparent substrate.

8. An optical laminate comprising a first transparent substrate, a second transparent substrate, and the laminate according to claim 6 or 7 disposed between the first transparent substrate and the second transparent substrate.

Images