Intermediate film and laminate

Abstract

This intermediate film has a glass transition temperature of at least 50°C and provides a puncture stroke of at least 18.6 mm in a puncture impact test performed on laminated glass obtained by bonding two 2.75 mm-thick float glass sheets with the intermediate film.

Description

Interlayers and laminates

[0001] This invention relates to an interlayer used in laminated glass and the like, and to a laminate having an interlayer.

[0002] Laminated glass is safer because, even if it breaks due to external impact, the glass fragments are less likely to scatter. Therefore, it is widely used in windows of various vehicles such as automobiles, railway cars, aircraft, and ships, as well as in buildings. Laminated glass is generally known to consist of two panes of glass with an interlayer made of thermoplastic resin or similar material sandwiched between them. When used in buildings, laminated glass is used not only for windows but also for glass floors and curtain walls. In these applications, it is sometimes produced in large sizes and used as structural glazing.

[0003] Ionomer resins have conventionally been used as interlayers for laminated glass. Known ionomer resins used as interlayers for laminated glass include ethylene-unsaturated carboxylic acid copolymers, such as ethylene-(meth)acrylic acid copolymers, in which at least some of the carboxyl groups of the side chains are crosslinked between molecular chains by metal cations (see, for example, Patent Documents 1 to 3).

[0004] International Publication No. 2022 / 065146, Japanese Patent Publication No. 2014-58409, International Publication No. 2019 / 054363

[0005] In architectural applications, laminated glass requires good static rigidity regardless of changes in outside temperature. Furthermore, from the perspective of safety during strong winds such as typhoons and hurricanes, resistance to high-speed impacts is also required. Additionally, resistance to high-speed impacts is sometimes required from a security standpoint.

[0006] However, when using the ionomer resins described in Patent Documents 1 to 3, the resulting laminated glass may have insufficient rigidity due to changes in ambient temperature, or it may have problems with resistance to high-speed impacts, and therefore cannot fully satisfy the above-mentioned performance requirements.

[0007] Therefore, the object of the present invention is to provide an interlayer film and a laminate that can ensure high static rigidity over a wide temperature range while also providing good resistance to high-speed impacts.

[0008] As a result of diligent research, the inventors have found that the above problems can be solved by raising both the puncture stroke amount and the glass transition temperature in the puncture impact test to a certain value or higher, and have completed the present invention relating to the following first aspect. That is, the first aspect of the present invention provides the following [1] to

[16] .

[0009] [1] An interlayer having a glass transition temperature of 50°C or higher, and a puncture stroke of 18.6 mm or more in a puncture impact test performed on laminated glass obtained by bonding two 2.75 mm thick float glass plates with an interlayer in between. [2] The interlayer according to [1], wherein the bending rigidity at 50°C of the laminated glass obtained by bonding two 2.75 mm thick float glass plates with an interlayer in between is 700 N / mm or more. [3] The interlayer according to [1] or [2], which contains an ionomer resin. [4] The interlayer according to [3], wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the total content of constituent units (A) derived from (meth)acrylic acid and constituent units (B) derived from (meth)acrylic acid neutralized product is 10% by mass or more and 25% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin. [5] The interlayer film according to [3] or [4] above, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units (B) derived from (meth)acrylic acid neutralized is 4% by mass or more and 17.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin. [6] The interlayer film according to any one of [3] to [5] above, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units (A) derived from (meth)acrylic acid is 0% by mass or more and 11.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin. [7] The interlayer according to any one of [3] to [6] above, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units derived from alkyl (meth)acrylate is 0% by mass or more and 4.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin. [8] The interlayer according to any one of [3] to [7] above, wherein the ionomer resin contains constituent units (A) derived from (meth)acrylic acid, constituent units (B) derived from (meth)acrylic acid neutralized product, and constituent units (C) derived from ethylene.[9] The interlayer film according to [8], wherein the constituent unit (B) comprises at least one of magnesium and zinc.

[10] The interlayer film according to any one of [3] to [9], further comprising a silane coupling agent, wherein the content of the silane coupling agent is 0.1% by mass or less based on the total mass of the interlayer film.

[11] The interlayer film according to any one of [1] to

[10] , wherein the glass transition temperature is 50°C or higher and 77°C or lower.

[12] A laminate comprising the interlayer film according to any one of [1] to

[11] and two substrates, wherein the interlayer film is disposed between the two substrates.

[13] The laminate according to

[12] , wherein the substrate is glass.

[14] A structural glazing for buildings, comprising the laminate according to

[12] or

[13] .

[15] A laminate comprising an interlayer and two substrates, wherein the interlayer is disposed between the two substrates, the glass transition temperature of the interlayer being 50°C or higher, and the puncture stroke in a puncture impact test performed on the laminate being 18.6 mm or higher.

[16] The laminate according to

[15] , wherein the interlayer contains an ionomer resin.

[0010] As a result of diligent research, the inventors have found that the above problems can be solved by lowering the glass transition temperature of the interlayer to below a certain value and raising the complex viscosity of the interlayer, measured at a measurement temperature of 200°C and a frequency of 1 Hz, to above a certain value, and have completed the present invention relating to the following second aspect. That is, the second aspect of the present invention provides the following

[17] to

[31] .

[17] An interlayer having a glass transition temperature of 50°C or more and a complex viscosity of 800 Pa·s or more, measured at a measurement temperature of 200°C and a frequency of 1 Hz.

[18] The interlayer according to

[17] , wherein the laminated glass obtained by placing the interlayer between two float glass plates with a thickness of 2.75 mm has a bending rigidity of 700 N / mm or more at 50°C.

[19] The interlayer according to

[17] or

[18] , which contains an ionomer resin.

[20] The interlayer film according to

[19] , wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the total content of constituent units (A) derived from (meth)acrylic acid and constituent units (B) derived from (meth)acrylic acid neutralized product is 10% by mass or more and 25% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin.

[21] The interlayer film according to

[19] or

[20] , wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units (B) derived from (meth)acrylic acid neutralized product is 4% by mass or more and 17.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin.

[22] The interlayer film according to any one of

[19] to

[21] above, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units (A) derived from (meth)acrylic acid is 0% by mass or more and 11.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin.

[23] An interlayer according to any one of

[19] to

[22] , wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units derived from alkyl (meth)acrylate is 0% by mass or more and 4.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin.

[24] An interlayer according to any one of

[19] to

[23] , wherein the ionomer resin contains constituent units (A) derived from (meth)acrylic acid, constituent units (B) derived from (meth)acrylic acid neutralized product, and constituent units (C) derived from ethylene.

[25] An interlayer according to

[24] , wherein the constituent unit (B) contains at least one of magnesium and zinc.

[26] An interlayer according to any one of

[19] to

[25] , further comprising a silane coupling agent, wherein the content of the silane coupling agent is 1% by mass or less based on the total mass of the interlayer.

[27] A laminate comprising an interlayer film as described in any of

[17] to

[26] above and two substrates, wherein the interlayer film is disposed between the two substrates.

[28] The laminate according to

[27] above, wherein the substrate is glass.

[29] A structural glazing for building buildings, comprising the laminate according to

[27] or

[28] above.

[30] A laminate comprising an interlayer film and two substrates, wherein the interlayer film is disposed between the two substrates, wherein the glass transition temperature of the interlayer film is 50°C or higher and 65°C or lower, and the complex viscosity of the interlayer film measured at a measurement temperature of 200°C and a frequency of 1 Hz is 800 Pa·s or higher.

[31] The laminate according to

[30] above, wherein the interlayer film contains an ionomer resin.

[0011] As a result of diligent research, the inventors have found that the above problems can be solved by setting the glass transition temperature to 58°C or higher and the Pammel value to less than 9.0, and have completed the present invention relating to the following third aspect. That is, the third aspect of the present invention provides the following

[32] to

[47] .

[32] An interlayer having a glass transition temperature of 58°C or higher and a Pammel value of less than 9.0.

[33] The interlayer according to

[32] , wherein the bending rigidity at 50°C of the laminated glass obtained by bonding two float glass plates with a thickness of 2.75 mm via the interlayer is 700 N / mm or higher.

[34] The interlayer according to

[32] or

[33] , which contains an ionomer resin.

[35] The interlayer film according to

[34] , wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the total content of constituent units (A) derived from (meth)acrylic acid and constituent units (B) derived from (meth)acrylic acid neutralized is 10% by mass or more and 25% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin.

[36] The interlayer film according to

[34] or

[35] , wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units (B) derived from (meth)acrylic acid neutralized is 4% by mass or more and 17.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin.

[37] The intermediate film according to any one of

[34] to

[36] above, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units (A) derived from (meth)acrylic acid is 0% by mass or more and 11.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin.

[38] The intermediate film according to any one of

[34] to

[37] above, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units derived from alkyl (meth)acrylate is 0% by mass or more and 4.5% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin.

[39] An interlayer according to any one of

[34] to

[38] , wherein the ionomer resin comprises a constituent unit (A) derived from (meth)acrylic acid, a constituent unit (B) derived from (meth)acrylic acid neutralized product, and a constituent unit (C) derived from ethylene.

[40] An interlayer according to

[39] , wherein the constituent unit (B) comprises at least one of magnesium and zinc.

[41] An interlayer according to any one of

[32] to

[40] , further comprising a silane coupling agent, wherein the content of the silane coupling agent is 0.15% by mass or less based on the total mass of the interlayer.

[42] An interlayer according to any one of

[32] to

[41] , wherein the glass transition temperature is 58°C or higher and 75°C or lower.

[43] A laminate comprising an interlayer according to any one of

[32] to

[42] , and two substrates, wherein the interlayer is disposed between the two substrates.

[44] The laminate according to

[43] , wherein the substrate is glass.

[45] A structural glazing for building buildings, comprising the laminate described in

[43] or

[44] above.

[46] A laminate comprising an interlayer and two substrates, wherein the interlayer is disposed between the two substrates, the glass transition temperature of the interlayer is 58°C or higher and the Pummel value is less than 9.0.

[47] The laminate described in

[46] above, wherein the interlayer contains an ionomer resin.

[0012] According to the interlayer film and laminate of the present invention, high static rigidity can be ensured over a wide temperature range while providing good resistance to high-speed impacts.

[0013] This is a schematic diagram illustrating the method for measuring bending stiffness. It is also a diagram illustrating the maximum test force.

[0014] The present invention will be described below with reference to embodiments. In the following description, the first aspect described above will be referred to as the first embodiment, the second aspect as the second embodiment, and the third aspect as the third embodiment. [First Embodiment] The interlayer according to the first embodiment of the present invention will be described below. <Interlayer> The interlayer according to the first embodiment of the present invention has a glass transition temperature of 50°C or higher and a puncture stroke of 18.6 mm or higher in a puncture impact test. By having the above configuration, the interlayer can ensure high static rigidity over a wide temperature range while providing good resistance to high-speed impact. The interlayer according to the first embodiment of the present invention will be described in detail below.

[0015] [Glass Transition Temperature (Tg)] As described above, the glass transition temperature (Tg) of the interlayer according to the first embodiment of the present invention is 50°C or higher. If the Tg of the interlayer is less than 50°C, the bending stiffness at high temperatures, for example around 50°C, will be low, making it difficult to ensure high static stiffness over a wide temperature range. From the viewpoint of suppressing a decrease in bending stiffness at high temperatures, the glass transition temperature (Tg) of the interlayer is preferably 55°C or higher, more preferably 58°C or higher, and even more preferably 60°C or higher. In addition, in the first embodiment, the glass transition temperature (Tg) of the interlayer is preferably 77°C or lower, more preferably 75°C or lower, even more preferably 73°C or lower, and even more preferably 71°C or lower. Setting the glass transition temperature (Tg) to be below the above upper limit makes it easier to impart a certain degree of flexibility to the interlayer. It also makes it easier to increase the puncture energy, which will be described later, and to further improve resistance to high-speed impacts. Therefore, in the first embodiment, the glass transition temperature (Tg) of the interlayer is, for example, 50°C to 77°C, preferably 55°C to 77°C, more preferably 58°C to 75°C, even more preferably 60°C to 73°C, and even more preferably 60°C to 71°C.

[0016] The glass transition temperature can be adjusted by the composition of the resin constituting the interlayer. For example, in the ionomer resin described later, it is easier to raise the temperature by increasing the degree of neutralization and thus increasing the amount of constituent units (B) of the unsaturated carboxylic acid neutralization product. Furthermore, it is easier to raise the temperature by using specific metal ions contained in constituent units (B). In addition, it is easier to raise the temperature by reducing the amount of constituent units derived from alkyl (meth)acrylate. The glass transition temperature can be detected by performing viscoelasticity measurements using a dynamic viscoelasticity measuring device and reading the peak temperature of the loss tangent tanδ obtained from the viscoelasticity measurement results. Details of the measurement conditions are as described in the examples. Furthermore, as described later, the interlayer may be a multilayer film with two or more layers. In this case, multiple peak temperatures of loss tangent tanδ may be measured. When multiple peak temperatures of loss tangent tanδ are measured, the highest peak temperature among them is taken as the glass transition temperature of the interlayer.

[0017] [Puncture Stroke] The interlayer according to the first embodiment of the present invention has a puncture stroke of 18.6 mm or more in a puncture impact test. If the puncture stroke is less than 18.6 mm, the resistance to high-speed impact will be low, and for example, safety in strong winds may not be sufficiently ensured. From the viewpoint of increasing resistance to high-speed impact, a higher puncture stroke in the puncture impact test is preferable, preferably 19.5 mm or more, and more preferably 21.0 mm or more. Furthermore, the upper limit of the puncture stroke is not particularly limited, and may be, for example, 35 mm, or 30 mm. Therefore, the puncture stroke in the puncture impact test is, for example, 18.6 mm or more and 35 mm or less, preferably 19.5 mm or more and 35 mm or less, and more preferably 21.0 mm or more and 30 mm or less.

[0018] The puncture stroke value can be adjusted by the composition of the resin constituting the interlayer and the thickness of the interlayer. For example, when using the ionomer resin described later, the puncture stroke value can be increased by appropriately adjusting the degree of neutralization and setting the proportion of constituent units (A) derived from unsaturated carboxylic acid within a predetermined range. Furthermore, the puncture stroke value can be increased by using specific metal ions contained in constituent units (B). It can also be adjusted by the molecular weight of the resin, the presence or absence of crosslinking, and the presence or absence of fillers. Normally, increasing the puncture stroke value tends to lower the glass transition temperature. However, in this invention, both the puncture stroke value and the glass transition temperature can be increased by using specific metal ions contained in constituent units (B) and appropriately adjusting the proportion of constituent units (A) derived from unsaturated carboxylic acid and the proportion of constituent units (B) of the unsaturated carboxylic acid neutralized product.

[0019] The resistance of the interlayer of the present invention to high-speed impact can be evaluated, for example, by puncture energy. When the interlayer has high resistance to high-speed impact, the puncture energy in the puncture impact test is usually also high. When the resistance of the interlayer of the first embodiment of the present invention to high-speed impact is evaluated by puncture energy, the puncture energy in the puncture impact test is, for example, 50 J or more, preferably 70 J or more, and more preferably 75 J or more. The value of the puncture energy can be appropriately adjusted depending on the composition of the resin constituting the interlayer, the thickness of the interlayer, the glass transition temperature, etc.

[0020] The puncture stroke and puncture energy are values ​​measured by performing a puncture impact test on laminated glass obtained by bonding two pieces of glass with a thickness of 2.75 mm (measured value, nominal value 3 mm) with an interlayer in between. Here, the measuring device used is, for example, the "Puncture Impact Tester HITS-PX" manufactured by Shimadzu Corporation. The measurement conditions are as follows: striker diameter φ20 mm, striker tip shape φ20 mm cylindrical (contact surface is flat), receiving-holding plate diameter φ100 mm, set speed 10 m / sec, sampling interval 0.5 μsec, temperature 25 °C, and clamp pressure of the test piece 0.7 MPa. Puncture point: Referring to JIS K7211, the puncture point is defined as the point where the test force value decreases to half of the maximum test force of the interlayer of the test piece. Puncture stroke: The stroke value at the puncture point is defined as the puncture stroke. Puncture energy: The integral value of the force-stroke diagram from the starting point to the puncture point is defined as the puncture energy. Details of the method for manufacturing the laminated glass used in the puncture impact test are also described in the examples. Furthermore, the glass used in the puncture impact test, with a thickness of 2.75 mm (measured value, nominal value 3 mm), is float glass, and its details are shown in the examples. In this specification, the measured value of the glass thickness can be determined using a micrometer in accordance with JIS B7502.

[0021] [Bending Stiffness] In the first embodiment of the present invention, the interlayer obtained by bonding two 2.75 mm thick glass sheets together via an interlayer for laminated glass preferably has a bending stiffness of 700 N / mm or more at 50°C. A bending stiffness of 700 N / mm or more at 50°C ensures high static stiffness regardless of ambient temperature, making it suitable for use in building applications. A bending stiffness of 800 N / mm or more at 50°C is more preferable, and 900 N / mm or more is even more preferable. While a higher bending stiffness of the interlayer at 50°C is desirable, from the viewpoint of ensuring a certain degree of flexibility in the interlayer, it may be, for example, 3000 N / mm or less, or 2000 N / mm or less. Therefore, the bending stiffness at 50°C is preferably 700 N / mm or more and 3000 N / mm or less, more preferably 800 N / mm or more and 3000 N / mm or less, and even more preferably 900 N / mm or more and 2000 N / mm or less.

[0022] Furthermore, in the first embodiment of the present invention, the interlayer obtained by bonding two 2.75 mm thick glass sheets together via the interlayer preferably has a bending rigidity of 1000 N / mm or more at 25°C. A bending rigidity of 1000 N / mm or more at 25°C ensures high static rigidity around 25°C, making it suitable for use in building applications. A bending rigidity of 1200 N / mm or more at 25°C is more preferably, 1300 N / mm or more is even more preferably, and 1400 N / mm or more is even more preferably. While a higher bending rigidity of the interlayer at 25°C is desirable, from the viewpoint of ensuring a certain degree of flexibility in the interlayer, it may be, for example, 4000 N / mm or less, 3000 N / mm or less, 2300 N / mm or less, or 2000 N / mm or less. Therefore, the bending stiffness at 25°C is preferably 1000 N / mm or more and 4000 N / mm or less, more preferably 1200 N / mm or more and 3000 N / mm or less, even more preferably 1300 N / mm or more and 2300 N / mm or less, and still more preferably 1400 N / mm or more and 2000 N / mm or less.

[0023] The interlayer according to the first embodiment of the present invention has a bending stiffness reduction rate calculated by the following formula, preferably 50% or less, more preferably 45% or less, even more preferably 40% or less, and even more preferably 38% or less. A low bending stiffness reduction rate makes it easier to ensure high static stiffness over a wide temperature range. The bending stiffness reduction rate may be 0% or more, but in practical terms it may be 5% or more, or even 10% or more. Bending stiffness reduction rate (%) = [(Bending stiffness at 25°C - Bending stiffness at 50°C) / Bending stiffness at 25°C] × 100

[0024] Bending stiffness can be adjusted by the type of resin, the composition of the monomers constituting the resin, the glass transition temperature (Tg) of the interlayer, and the thickness of the interlayer. For example, increasing the glass transition temperature (Tg) of the interlayer can increase the bending stiffness at 50°C. Furthermore, using ionomer resins makes it easier to increase bending stiffness, and using high-Tg monomers in the ionomer resin while reducing the low-Tg component or increasing the degree of neutralization also makes it easier to increase the bending stiffness at 50°C. In addition, when other resin components are included in addition to the ionomer resin, reducing the content of the other resin components makes it easier to maintain high bending stiffness, especially at high temperatures.

[0025] The bending stiffness at 50°C or 25°C mentioned above is best measured by pre-bonding two 2.75 mm thick glass sheets with an interlayer, then performing the final bonding in an autoclave to obtain a laminated glass sheet for measurement, curing it for one week, and then measuring it in an environment of 25°C or 50°C. The manufacturing conditions for the laminated glass sheet for measurement should be as shown in the manufacturing method of laminated glass described in the examples below. The 2.75 mm thick glass used for bending stiffness measurement is float glass, and its details are as shown in the examples.

[0026] [Complex Viscosity] The interlayer film according to the first embodiment of the present invention preferably has a complex viscosity of 800 Pa·s or more, measured at a measurement temperature of 200°C and a frequency of 1 Hz. A complex viscosity of 800 Pa·s or more prevents a decrease in puncture energy, improves resistance to high-speed impact, and makes it easier to ensure high static rigidity over a wide temperature range. In the first embodiment of the present invention, flexibility tends to decrease as the glass transition temperature increases as described above, but even if flexibility decreases, the interlayer film is prevented from becoming brittle, and static rigidity and resistance to high-speed impact are further improved. The complex viscosity of the interlayer film is more preferably 1000 Pa·s or more, and even more preferably 1300 Pa·s or more. Furthermore, from the viewpoint of moldability and handling, the complex viscosity of the interlayer film is preferably 3000 Pa·s or less, more preferably 2500 Pa·s or less, and even more preferably 2000 Pa·s or less. The method for measuring the complex viscosity is as described in the examples. Therefore, the complex viscosity is preferably 800 Pa·s to 3000 Pa·s, more preferably 1000 Pa·s to 2500 Pa·s, and even more preferably 1300 Pa·s to 2000 Pa·s. The complex viscosity of the interlayer can be adjusted, for example, by controlling the molecular weight of the resin used in the interlayer, and, in the case of an ionomer resin, by controlling the content of each constituent unit that makes up the ionomer resin in addition to the above.

[0027] [Pammel Value] The pammel value of the interlayer according to the first embodiment may be 1 or more and 9 or less, but from the viewpoint of improving the adhesion of the interlayer to the glass, a higher value is preferable, preferably 3 or more and 9 or less, more preferably 5 or more and 9 or less, and even more preferably 7 or more and 9 or less. By increasing the pammel value, the interlayer can be suitably used in laminated glass for building applications. The pammel value can be determined by measuring it on laminated glass obtained by bonding two pieces of glass with a thickness of 2.75 mm (measured value, nominal value 3 mm) via an interlayer. Details of the method for measuring the pammel value and the method for manufacturing the laminated glass used for measuring the pammel value are shown in the examples. The 2.75 mm glass used for measuring the pammel value is float glass, and details thereof are also shown in the examples.

[0028] The Pammel value can be adjusted by the composition of the resin constituting the interlayer and the additives contained in the interlayer. For example, in the ionomer resin described later, the Pammel value can be easily increased by lowering the degree of neutralization and increasing the proportion of constituent units (A) derived from carboxylic acid. In addition, the Pammel value can be easily increased by including a silane coupling agent, described later, in the interlayer and increasing its content.

[0029] (Second Embodiment) Next, an interlayer according to the second embodiment of the present invention will be described. <Interlayer> The interlayer according to the second embodiment of the present invention has a glass transition temperature of 50°C or more and 65°C or less, and a complex viscosity of 800 Pa·s or more measured at a measurement temperature of 200°C and a frequency of 1 Hz. By having the above configuration, the interlayer of the present invention can ensure high static rigidity over a wide temperature range while providing good resistance to high-speed impact. The interlayer according to the second embodiment of the present invention will be described in detail below.

[0030] [Glass Transition Temperature (Tg)] As described above, the glass transition temperature (Tg) of the interlayer in the second embodiment of the present invention is 50°C or higher and 65°C or lower. If the glass transition temperature (Tg) of the interlayer is higher than 65°C, the interlayer loses flexibility and becomes brittle, resulting in a decrease in puncture energy and reduced resistance to high-speed impact. From this viewpoint, the glass transition temperature (Tg) of the interlayer of the present invention is preferably 64°C or lower. Alternatively, the glass transition temperature (Tg) of the interlayer of the present invention is 50°C or higher. If the glass transition temperature (Tg) of the interlayer is less than 50°C, the rate of decrease in bending stiffness increases, and it may become difficult to ensure high static stiffness over a wide temperature range. From this viewpoint, in the second embodiment, the glass transition temperature (Tg) of the interlayer is preferably 55°C or higher, more preferably 58°C or higher, and even more preferably 60°C or higher. Therefore, the glass transition temperature (Tg) of the interlayer according to the second embodiment is preferably 55°C to 64°C, more preferably 58°C to 64°C, and even more preferably 60°C to 64°C. The method for adjusting and measuring the glass transition temperature is as described in the first embodiment. Furthermore, as will be described later, the interlayer may be a multilayer film of two or more layers, in which case the glass transition temperature is also as described above.

[0031] [Complex Viscosity] The complex viscosity of the interfilm according to the second embodiment of the present invention, measured at a measurement temperature of 200°C and a frequency of 1 Hz, is 800 Pa·s or more. If the complex viscosity is less than 800 Pa·s, the puncture energy decreases, resulting in reduced resistance to high-speed impacts and making it difficult to ensure high static rigidity over a wide temperature range. The complex viscosity of the interfilm according to the second embodiment, measured at a measurement temperature of 200°C and a frequency of 1 Hz, is more preferably 1000 Pa·s or more, and even more preferably 1300 Pa·s or more. Furthermore, the complex viscosity of the interfilm at 200°C is preferably 3000 Pa·s or less, more preferably 2500 Pa·s or less, and even more preferably 2000 Pa·s or less, from the viewpoint of moldability and handling. Therefore, in the second embodiment, the complex viscosity is preferably 800 Pa·s to 3000 Pa·s, more preferably 1000 Pa·s to 2500 Pa·s, and even more preferably 1300 Pa·s to 2000 Pa·s. The method for measuring the complex viscosity is as described in the examples. The method for adjusting the complex viscosity of the interlayer film is as described in the first embodiment.

[0032] [Bending Stiffness] The interlayer of the second embodiment of the present invention has bending stiffness at 50°C and 25°C as described in the first embodiment, obtained by bonding two 2.75 mm thick glass sheets together via an interlayer for laminated glass. The interlayer of the second embodiment of the present invention has a bending stiffness reduction rate calculated by the above formula preferably of 60% or less, more preferably of 55% or less, even more preferably of 47% or less, and even more preferably of 45% or less. A low bending stiffness reduction rate makes it easier to ensure high static stiffness over a wide temperature range. The bending stiffness reduction rate may be 0% or more, but practically it may be 5% or more, or even 10% or more. The method for adjusting and measuring bending stiffness is as described in the first embodiment, and the manufacturing conditions for the laminated glass for measurement may also be as shown in the method for manufacturing laminated glass shown in the examples described later. The 2.75 mm glass used when measuring bending stiffness is float glass, and its details are as shown in the examples.

[0033] [Puncture Stroke and Pammel Value] In the interlayer according to the second embodiment of the present invention, it is preferable that the puncture stroke in the puncture impact test is 18.6 mm or more. When the puncture stroke is 18.6 mm or more, it becomes easier to increase the puncture energy, and as a result, the resistance to high-speed impact is further increased, and safety in strong winds, for example, can be more sufficiently ensured. From the viewpoint of further increasing the resistance to high-speed impact, a higher puncture stroke in the puncture impact test is preferable, more preferably 19.5 mm or more, and even more preferably 21.0 mm or more. Furthermore, the upper limit of the puncture stroke is not particularly limited, and may be, for example, 35 mm, or 30 mm.

[0034] The resistance of the interlayer film to high-speed impact according to the second embodiment of the present invention can be evaluated, for example, by puncture energy, the details of which are described in the first embodiment. In the second embodiment, it is easier to increase the puncture energy, thereby further improving the resistance to high-speed impact. The puncture energy in the puncture impact test in the second embodiment is, for example, 50 J or more, preferably 70 J or more, more preferably 75 J or more, and even more preferably 78 J or more. The method for measuring the puncture stroke and puncture energy, and the method for adjusting the value of the puncture stroke are as described in the first embodiment. The puncture value of the interlayer film according to the second embodiment is also as described in the first embodiment, and the details of its explanation are omitted.

[0035] [Third Embodiment] Next, an interlayer according to the third embodiment of the present invention will be described. <Interlayer> The interlayer according to the third embodiment of the present invention has a glass transition temperature of 58°C or higher and a Pammel value of less than 9.0. By having the above configuration, the interlayer can ensure high static rigidity over a wide temperature range while providing good resistance to high-speed impacts. The interlayer according to the third embodiment of the present invention will be described in detail below.

[0036] [Glass Transition Temperature (Tg)] As described above, the glass transition temperature (Tg) of the interlayer according to the third embodiment of the present invention is 58°C or higher. If the Tg of the interlayer is less than 58°C, the bending stiffness at high temperatures (for example, around 50-60°C) will be low, making it difficult to ensure high static stiffness over a wide temperature range. From the viewpoint of suppressing the decrease in bending stiffness at high temperatures, the glass transition temperature (Tg) of the interlayer according to the third embodiment is preferably 59°C or higher, more preferably 60°C or higher, and even more preferably 62°C or higher. Furthermore, the glass transition temperature (Tg) of the interlayer according to the third embodiment is preferably 75°C or lower, more preferably 73°C or lower, and even more preferably 70°C or lower. By setting the glass transition temperature (Tg) to or below the above upper limit, it becomes easier to impart a certain degree of flexibility to the interlayer. Therefore, the interlayer according to the third embodiment preferably has a glass transition temperature (Tg) of, for example, 58°C to 75°C, 59°C to 75°C, more preferably 60°C to 73°C, and even more preferably 62°C to 70°C. The method for adjusting and measuring the glass transition temperature is as described in the first embodiment. Furthermore, as will be described later, the interlayer may be a multilayer film of two or more layers, in which case the glass transition temperature is also as described above.

[0037] [Pamell value] The intermediate film according to the third embodiment of the present invention has a Pamell value of less than 9.0. If the Pamell value is 9.0 or more, the resistance to high-speed impact will be low, and for example, the safety during strong winds may not be sufficiently ensured. From the viewpoint of making the resistance to high-speed impact higher, the Pamell value is preferably 8.5 or less, more preferably 8.0 or less, and even more preferably 7.5 or less. Also, in the third embodiment, the Pamell value is preferably 1 or more, more preferably 3 or more, even more preferably 5 or more, and even more preferably 7 or more from the viewpoint of enhancing the adhesion between the intermediate film and the glass and preventing peeling, foaming, etc. Therefore, the intermediate film according to the third embodiment has, for example, a Pamell value of 1 or more and less than 9.0, preferably 1 or more and 8.5 or less, more preferably 3 or more and 8.0 or less, and even more preferably 5 or more and 7.5 or less. The Pamell value can be obtained by measuring a laminated glass obtained by bonding two pieces of glass with a thickness of 2.75 mm (measured value, nominal value is 3 mm) via the intermediate film. The details of the method for measuring the Pamell value and the method for producing the laminated glass used for measuring the Pamell value are as shown in the examples. Also, the glass with a thickness of 2.75 mm used for measuring the Pamell value is float plate glass, and the details are also as shown in the examples.

[0038] As described in the first embodiment, the Pamell value can be adjusted according to the types of resins and additives contained in the intermediate film. When an ionomer resin is used for the intermediate film, generally, it is difficult to adjust the Pamell value to be higher (for example, in the range of 7 or more and less than 9.0). In order to obtain such a range, it is necessary to appropriately adjust the molecular structure of the ionomer resin and the composition of the intermediate film (types and amounts of additives, etc.).

[0039] [Bending Stiffness] The interlayer in the third embodiment of the present invention is a laminated glass obtained by bonding two 2.75 mm thick glass sheets together via an interlayer for laminated glass, and its bending stiffness at 50°C and 25°C is as described in the first embodiment. The interlayer in the third embodiment of the present invention has a bending stiffness reduction rate calculated by the above formula that is preferably 55% or less, more preferably 50% or less, even more preferably 45% or less, and even more preferably 40% or less. The low bending stiffness reduction rate of the interlayer makes it easier to ensure high static stiffness over a wide temperature range. The bending stiffness reduction rate should be 0% or more, but practically it may be 5% or more, or even 10% or more. The method for adjusting and measuring bending stiffness is as described in the first embodiment, and the manufacturing conditions for the laminated glass for measurement should also be as shown in the method for manufacturing laminated glass shown in the examples described later. In addition, the 2.75 mm glass used when measuring bending stiffness in the third embodiment is float glass, and its details are as shown in the examples. The thickness of 2.75 mm is an actual measured value.

[0040] [Complex Viscosity] The complex viscosity of the interlayer film according to the third embodiment of the present invention, measured at a measurement temperature of 200°C and a frequency of 1 Hz, is as described in the first embodiment above. The method for measuring the complex viscosity is as described in the examples, and the method for adjusting the complex viscosity of the interlayer film is as described in the first embodiment above.

[0041] [Resin] Next, the composition of the interlayer film according to each embodiment of the present invention will be described. The interlayer film according to each embodiment of the present invention preferably contains a resin. The resin used for the interlayer film is preferably a thermoplastic resin. By using a thermoplastic resin for the interlayer film, it becomes easier to adhere two base materials or two glasses to each other by thermocompression bonding through the interlayer film. In addition, examples of the resin used for the interlayer film include polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ionomer resin, polyurethane resin, and thermoplastic elastomer. Among these, an ionomer resin is preferable. By using an ionomer resin, for example, in the first and second embodiments, it becomes easier to increase both the glass transition temperature and the value of the punch stroke in the puncture impact test. Also, for example, in the third embodiment, by using an ionomer resin, it becomes easier to increase the glass transition temperature while adjusting the panmel value to be below a certain level.

[0042] [Ionomer Resin] Hereinafter, the ionomer resin used in each embodiment of the present invention will be described in more detail. Examples of the ionomer resin include ionomer resins of ethylene / unsaturated carboxylic acid copolymers. An ionomer resin is typically a resin obtained by neutralizing an ethylene / unsaturated carboxylic acid copolymer with metal ions. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, 2-ethylacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, monomethyl maleate, monoethyl maleate, and the like. In the ionomer resin, the unsaturated carboxylic acid may be used alone or in combination of two or more. Among these, acrylic acid and methacrylic acid are preferable. Therefore, the ionomer resin is preferably an ionomer resin of an ethylene / (meth)acrylic acid copolymer. Note that (meth)acrylic acid means at least either methacrylic acid or acrylic acid, and the same applies to the following similar terms.

[0043] In each embodiment, examples of metal ions include lithium, potassium, sodium, silver, copper, calcium, magnesium, titanium, zinc, aluminum, barium, beryllium, strontium, tin, lead, iron, cobalt, nickel, cadmium, and mercury. Among these, in the first embodiment, at least one of magnesium and zinc is preferred, and magnesium is particularly preferred. In each embodiment, one metal ion may be used alone, or two or more may be used in combination. In the first embodiment, using at least one of magnesium and zinc, particularly magnesium, as the metal ion makes it easier to form an appropriate crosslinked structure, increasing the puncture stroke value while also increasing the glass transition temperature of the interlayer, and making it easier to increase the bending stiffness at both 25 and 50°C. In the second embodiment, at least one of sodium, magnesium, and zinc is preferred as the metal ion, and magnesium is particularly preferred. As for the metal ion, using at least one of sodium, magnesium, and zinc, and especially magnesium, makes it easier to form an appropriate crosslinking structure, thereby increasing the glass transition temperature of the interlayer and increasing the complex viscosity of the interlayer at 200°C. Furthermore, in the third embodiment, among the above, at least one of magnesium and zinc is preferred as the metal ion, and magnesium is particularly preferred. Using at least one of magnesium and zinc, and especially magnesium, as the metal ion makes it easier to form an appropriate crosslinking structure, thereby increasing the glass transition temperature of the interlayer while lowering the Pammel value, and making it easier to increase the bending stiffness at both 25°C and 50°C.

[0044] When the ionomer resin is an ethylene-unsaturated carboxylic acid copolymer, it typically contains constituent units (A) derived from the unsaturated carboxylic acid, constituent units (B) derived from the neutralized unsaturated carboxylic acid, and constituent units (C) derived from ethylene. In particular, when the ionomer resin is an ethylene-(meth)acrylic acid copolymer, it typically contains constituent units (constituent unit (A)) derived from (meth)acrylic acid, constituent units (constituent unit (B)) derived from the neutralized (meth)acrylic acid, and constituent units (C) derived from ethylene. By containing these constituent units (A), (B), and (C), the ionomer resin, for example in the first embodiment, makes it easier to improve the glass transition temperature and puncture stroke, and to achieve excellent bending stiffness at 25°C and 50°C. Furthermore, for example in the second embodiment, by containing these constituent units (A), (B), and (C), the ionomer resin makes it easier to lower the glass transition temperature of the interlayer while increasing the complex viscosity of the interlayer at 200°C. Furthermore, in the third embodiment, for example, the inclusion of these constituent units (A), (B), and (C) in the ionomer resin makes it easier to adjust the glass transition temperature and Pammel value to a desired range, and makes it easier to achieve excellent bending stiffness at 25°C and 50°C, and resistance to high-speed impact.

[0045] The monomer constituting unit (A) is not particularly limited as long as it is an unsaturated carboxylic acid, but it is preferably at least one of acrylic acid and methacrylic acid. Of these, methacrylic acid is more preferable from the viewpoint of bending rigidity and adhesiveness. Unit (A) is a unit that has not been neutralized by a metal ion. Unit (B) is a neutralized product of the unit derived from the above unsaturated carboxylic acid, but it is preferably a neutralized product of a unit derived from at least one of acrylic acid and methacrylic acid, and more preferably a unit of a methacrylic acid neutralized product. Unit (B) is a unit in which the hydrogen ion of the carboxyl group in the unsaturated carboxylic acid is replaced with a metal ion. That is, the unsaturated carboxylic acid neutralized product in unit (B) is a metal salt of the unsaturated carboxylic acid. The metal ion in the metal salt is as described above, but at least one of magnesium and zinc is preferred. Furthermore, as described above, the glass transition temperature (Tg) of the interlayer film according to the first and second embodiments is high at 50°C or above. From the viewpoint of making it easier to raise the glass transition temperature (Tg) of the interlayer film according to the first and second embodiments, magnesium is particularly preferred as the metal ion in the metal salt. Similarly, in the third embodiment, magnesium is particularly preferred as the metal ion in the metal salt from the viewpoint of raising the glass transition temperature of the interlayer film. Therefore, in each embodiment, it is preferable that the constituent unit (B) contains at least one of magnesium and zinc, and it is particularly preferable that it contains magnesium.

[0046] The ionomer resin may be obtained by neutralizing a copolymer of ethylene and an unsaturated carboxylic acid with metal ions, or by neutralizing a copolymer of ethylene, an unsaturated carboxylic acid, and monomers other than ethylene and an unsaturated carboxylic acid with metal ions. Therefore, in addition to constituent units (A), (B), and (C), the ionomer resin may also contain constituent units other than constituent units (A), (B), and (C) (hereinafter also referred to as "other constituent units").

[0047] Other constituent units include constituent unit (D) derived from alkyl (meth)acrylate. The presence of constituent unit (D) allows for adjustment of the glass transition temperature (Tg) of, for example, ionomer resins. Examples of alkyl (meth)acrylates include alkyl (meth)acrylates with approximately 1 to 10 carbon atoms in the alkyl group, such as methyl (meth)acrylate, ethyl (meth)acrylate, isobutyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.

[0048] The ionomer resin has a melt mass flow rate (MFR) measured in accordance with JIS K7210:1999 under conditions of 190°C and a 2160g load, which, from the viewpoint of processability and mechanical strength, is, for example, 0.01 g / 10 min to 150 g / 10 min, preferably 0.01 g / 10 min to 50 g / 10 min, more preferably 0.1 g / 10 min to 30 g / 10 min, and even more preferably 0.1 g / 10 min to 10 g / 10 min.

[0049] In each embodiment, the ionomer resin content in the interlayer is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 78% by mass or more, and even more preferably 88% by mass or more, when the entire interlayer is considered to be 100% by mass. By setting the ionomer resin content to be above the above lower limit, the rigidity and interlayer adhesion of the resulting laminated glass can be improved. It also becomes easier to increase the puncture energy and improve impact resistance. Furthermore, the ionomer resin content in the interlayer may be 100% by mass or less when the entire interlayer is considered to be 100% by mass or less, but from the viewpoint of including a certain amount or more of additives, it may be, for example, 99.99% by mass or less, or 99.9% by mass or less. In addition, when the interlayer contains other resin components described later, it is preferable to keep the ionomer resin content in the interlayer below a certain amount, for example, in the first embodiment, it may be 98% by mass or less, 97% by mass or less, or 96% by mass or less. Furthermore, in the second embodiment, for example, it may be 98% by mass or less, preferably 97% by mass or less, more preferably 96% by mass or less, and even more preferably 92% by mass or less. Furthermore, in the third embodiment, for example, it may be 98% by mass or less, 95% by mass or less, or 90% by mass or less.

[0050] The method for producing ionomer resins is not particularly limited and can be produced by known methods. For example, an ethylene-unsaturated carboxylic acid copolymer can be obtained by radical copolymerizing each monomer component under high temperature and high pressure, and then reacting the copolymer with a metal compound.

[0051] [Other Resin Components] In each embodiment, the interlayer may contain other resin components in addition to the ionomer resin. The ionomer resin may become too viscous during kneading, reducing its moldability, such as extrudeability. However, by including other resin components in the interlayer, it becomes easier to improve the moldability, such as extrudeability. Furthermore, by including other resin components in the interlayer, it becomes easier to adjust the complex viscosity measured at a measurement temperature of 200°C and a frequency of 1 Hz, for example, in the second embodiment. The other resin component is preferably a resin that is compatible with the ionomer resin. From the viewpoint of compatibility with the ionomer resin, an ethylene-unsaturated carboxylic acid copolymer is preferred as the other resin component. Here, the unsaturated carboxylic acid used in the ethylene-unsaturated carboxylic acid copolymer is as described above, with (meth)acrylic acid being preferred, and methacrylic acid being more preferred. Therefore, an ethylene-(meth)acrylic acid copolymer is preferred as the other resin.

[0052] Ethylene-unsaturated carboxylic acid copolymers, such as ethylene-(meth)acrylic acid copolymers used as other resins, can also be described as copolymers containing constituent units (A) derived from unsaturated carboxylic acids (typically, constituent units (A) derived from (meth)acrylic acid) and constituent units (C) derived from ethylene. Furthermore, ethylene-unsaturated carboxylic acid copolymers used as other resins may contain constituent units other than (A) and (C) (other constituent units). Examples of other constituent units include constituent units (D) derived from alkyl (meth)acrylate. Therefore, ethylene-unsaturated carboxylic acid copolymers may consist only of constituent units (A) and (C), but they may also contain constituent units (D) derived from alkyl (meth)acrylate in addition to constituent units (A) and (C). Details of alkyl (meth)acrylate are as described above.

[0053] The ionomer resin may also contain other constituent units other than constituent units (A), (B), (C), and (D), for example, it may have constituent units derived from vinyl esters such as vinyl acetate and vinyl propionate.

[0054] From the viewpoint of compatibility and extrudeability, it is preferable that the other resin components be copolymers of the same type as those used in the ionomer resin, and more preferably that the resin be used before neutralization with metal ions to obtain the ionomer resin. Therefore, if the ionomer resin is an ionomer resin of ethylene-(meth)acrylic acid copolymer, it is preferable that the other resin components be ethylene-(meth)acrylic acid copolymers. Also, if the ionomer resin is an ionomer resin of ethylene-methacrylic acid copolymer, it is preferable that the other resin components be ethylene-methacrylic acid copolymers.

[0055] In each embodiment, the content of other resin components is preferably 1.5% by mass or more and 25% by mass or less, based on 100% by mass of the entire interlayer. By setting the content of other resin components to 1.5% by mass or more, the complex viscosity of the ionomer resin is reduced, making it easier to improve extrudeability. Furthermore, by setting it to 25% by mass or less, it is possible to prevent a decrease in bending rigidity even when other resin components are included. In the first embodiment, the content of other resin components is more preferably 2.5% by mass or more and 18% by mass or less, and even more preferably 3.5% by mass or more and 11% by mass or less, based on 100% by mass of the entire interlayer. In the second embodiment, the content of other resin components is more preferably 3% by mass or more and 23% by mass or less, and even more preferably 7% by mass or more and 21% by mass or less, based on 100% by mass of the entire interlayer. Furthermore, in the third embodiment, the content of other resin components is more preferably 2.5% by mass or more and 20% by mass or less, and even more preferably 3.5% by mass or more and 15% by mass or less, based on 100% by mass of the entire interlayer. However, in each embodiment of the interlayer, other resin components may not be used, and the resin component in the interlayer may be made of an ionomer resin.

[0056] Furthermore, while interlayers generally contain polyvinyl acetal resin, it is preferable that the interlayers in each embodiment of the present invention do not contain polyvinyl acetal resin, and it is especially preferable that the interlayers in each embodiment of the present invention do not contain polyvinyl acetal resin when they contain ionomer resin. By not including polyvinyl acetal resin, the bending rigidity is increased, which tends to lead to higher static rigidity and resistance to high-speed impacts. Moreover, in each embodiment, if the interlayer contains polyvinyl acetal resin in addition to ionomer resin, the transparency of the interlayer decreases, so from this viewpoint as well, it is preferable that the interlayers in each embodiment of the present invention, when they contain ionomer resin, do not contain polyvinyl acetal resin.

[0057] The content of the resin component (for example, the total amount of ionomer resin and ethylene-(meth)acrylic acid copolymer) in the interlayer film according to each embodiment is not particularly limited when the entire interlayer film is considered to be 100% by mass, but is, for example, 60% by mass or more and 100% by mass or less, preferably 70% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, and even more preferably 90% by mass or more and 100% by mass or less.

[0058] (Degree of Neutralization) In the first and second embodiments, the degree of neutralization of the ethylene-unsaturated carboxylic acid copolymer and its ionomer resin contained in the interlayer is, for example, 30% or more, but preferably more than 40%, more preferably 45% or more, even more preferably 50% or more, and even more preferably 55% or more. For example, in the first embodiment, a certain degree of neutralization tends to increase the glass transition temperature and the bending stiffness, particularly the bending stiffness at 50°C. Similarly, in the second embodiment, for example, a higher degree of neutralization tends to increase the bending stiffness, particularly the bending stiffness at 50°C, and also tends to increase the puncture energy. Furthermore, in the first embodiment of the present invention, by containing at least one of magnesium and zinc (particularly magnesium) in the constituent unit (B) and increasing the degree of neutralization, both the glass transition temperature and the puncture stroke tend to be increased. Furthermore, in the second embodiment, by including at least one of magnesium and zinc (particularly magnesium) in the constituent unit (B) and increasing the degree of neutralization, it becomes easier to increase both the complex viscosity and glass transition temperature of the interlayer film at 200°C.

[0059] Furthermore, the degree of neutralization of the ethylene-unsaturated carboxylic acid copolymer and its ionomer resin is not particularly limited, but is preferably 80% or less, more preferably 75% or less, even more preferably 70% or less, and even more preferably 65% ​​or less. For example, in the first embodiment, by setting the degree of neutralization to a certain value or less and including a certain amount or more of the constituent unit (A), it becomes easier to increase the puncture stroke value. Also, by setting the degree of neutralization to a certain value or less, the glass transition temperature tends to fall within the desired range, and the flexibility, adhesion, mechanical strength, processability, etc. of the interlayer can be improved. Also, for example, in the second embodiment, by setting the degree of neutralization to a certain value or less and including a certain amount or more of the constituent unit (A), it becomes easier to prevent the glass transition temperature and complex viscosity from becoming too high. In the first and second embodiments, the degree of neutralization is, for example, 30% or more and 80% or less, but is preferably more than 40% and 80% or less, more preferably 45% or more and 75% or less, even more preferably 50% or more and 70% or less, and even more preferably 55% or more and 65% or less.

[0060] In the third embodiment, the degree of neutralization of the ethylene-unsaturated carboxylic acid copolymer and its ionomer resin contained in the interlayer is, for example, 30% or more, preferably 40% or more, more preferably 45% or more, even more preferably 50% or more, and even more preferably 55% or more. A higher degree of neutralization leads to a higher glass transition temperature, which in turn tends to increase the bending stiffness, particularly the bending stiffness at 50°C. Furthermore, in the third embodiment of the present invention, by containing at least one of magnesium and zinc (particularly magnesium) in the constituent unit (B) and increasing the degree of neutralization, it becomes easier to adjust the Pammel value to a certain level or less while increasing the glass transition temperature. Furthermore, in the third embodiment, the degree of neutralization of the ethylene-unsaturated carboxylic acid copolymer and its ionomer resin is not particularly limited, but is preferably 95% or less, more preferably 90% or less, even more preferably 80% or less, and even more preferably 75% or less. By keeping the degree of neutralization below a certain value and including a certain amount or more of the constituent unit (A), the flexibility, adhesion, mechanical strength, processability, etc. of the interlayer film can be further improved. Therefore, the degree of neutralization in the third embodiment is, for example, 30% to 95%, but is preferably 40% to 95%, more preferably 45% to 90%, even more preferably 50% to 80%, and even more preferably 55% to 75%.

[0061] In this specification, the degree of neutralization refers to the percentage (%) of all carboxyl groups contained in the ethylene-unsaturated carboxylic acid copolymer and its ionomer resin contained in the interlayer that are neutralized by metal ions.

[0062] (Content of constituent units) In each embodiment below, when an ionomer resin of an ethylene-(meth)acrylic acid copolymer is used as the ionomer resin, the content of constituent units (A) derived from (meth)acrylic acid, constituent units (B) derived from (meth)acrylic acid neutralized product, and constituent units (C) derived from ethylene in the interlayer will be described. Note that the constituent units (A) derived from (meth)acrylic acid described below include not only ionomer resin but also constituent units (A) derived from ethylene-(meth)acrylic acid copolymers that are not ionomer resins. Similarly, the constituent units (C) derived from ethylene include not only ionomer resin but also constituent units (C) derived from ethylene-(meth)acrylic acid copolymers that are not ionomer resins. Furthermore, the constituent units (D) derived from alkyl (meth)acrylate also include constituent units (D) derived from ethylene-(meth)acrylic acid copolymers that are not ionomer resins. Furthermore, the content of each constituent unit is based on the total amount of ethylene-(meth)acrylic acid copolymer ionomer resin and ethylene-(meth)acrylic acid copolymer, as explained below. However, the interlayer does not need to contain ethylene-(meth)acrylic acid copolymer as described above.

[0063] In the interlayer film of each embodiment, the total content of constituent units (A) derived from (meth)acrylic acid and constituent units (B) derived from (meth)acrylic acid neutralized product is preferably 10% by mass or more and 25% by mass or less, based on the total amount of ethylene-(meth)acrylic acid copolymer and its ionomer resin. When the total content of constituent units (A) and (B) is 10% by mass or more, the transparency, heat resistance, and mechanical strength of the interlayer film can be improved. When it is 25% by mass or less, flexibility, processability, and adhesion can be improved. Furthermore, when the total content is within the above range, for example in the first embodiment, it becomes easier to adjust the glass transition temperature to a desired range while improving the puncture stroke. Also, when the total content is within the above range, for example in the second embodiment, it becomes easier to increase the complex viscosity of the interlayer film at 200°C while lowering the glass transition temperature of the interlayer film. Furthermore, for example in the third embodiment, when the total content is within the above range, the glass transition temperature can be increased, and it becomes easier to adjust the Pammel value to below a certain level. In the first embodiment, the total content of constituent units (A) and (B) is more preferably 12% by mass or more and 23% by mass or less, even more preferably 15% by mass or more and 20% by mass or less, and even more preferably 15% by mass or more and 19% by mass or less. In the second embodiment, the total content of constituent units (A) and (B) is more preferably 12% by mass or more and 23% by mass or less, even more preferably 14% by mass or more and 21% by mass or less, and even more preferably 15% by mass or more and 20% by mass or less. In the third embodiment, the total content of constituent units (A) and (B) is more preferably 12% by mass or more and 23% by mass or less, even more preferably 15% by mass or more and 22% by mass or less, and even more preferably 15% by mass or more and 20% by mass or less.

[0064] In the interlayer film according to each embodiment, the content of constituent unit (B) derived from (meth)acrylic acid neutralized is, for example, 4% by mass or more and 17.5% by mass or less, based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin. When the content of constituent unit (B) is 4% by mass or more, for example in the first and third embodiments, the degree of crosslinking of the ionomer resin is increased, making it easier to raise the glass transition temperature and to increase the bending stiffness, especially the bending stiffness at 50°C. Also, for example in the second embodiment, the degree of crosslinking of the ionomer resin is increased, making it easier to raise the complex viscosity of the interlayer film at 200°C while adjusting the glass transition temperature of the interlayer film within a desired range. Furthermore, when the content of constituent unit (B) is 4% by mass or more in each embodiment, it is easier to increase transparency and heat resistance. Also, by setting the content of constituent unit (B) to 17.5% by mass or less, it is easier to improve the flexibility, adhesion, mechanical strength, processability, etc. of the interlayer film. In each embodiment, the content of constituent unit (B) derived from (meth)acrylic acid neutralized is preferably 6% by mass or more and 17% by mass or less, more preferably 7% by mass or more and 16% by mass or less, even more preferably 10% by mass or more and 16% by mass or less, and even more preferably 11% by mass or more and 15% by mass or less.

[0065] In the interlayer film according to each embodiment, the content of ethylene-derived constituent units (C) is preferably 70% by mass or more, more preferably 75% by mass or more, even more preferably 80% by mass or more, and even more preferably 82% by mass or more, based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin, from the viewpoint of easily improving the impact resistance of the ionomer resin. Furthermore, the content of ethylene-derived constituent units (C) is preferably 90% by mass or less, more preferably 89% by mass or less, even more preferably 88% by mass or less, and even more preferably 85% by mass or less, from the viewpoint of transparency, mechanical strength, and moldability.

[0066] The content of constituent unit (A) derived from (meth)acrylic acid is, in the first embodiment, from the viewpoint of making it easier to improve both the glass transition temperature and the puncture stroke, and in the second embodiment, from the viewpoint of making it easier to lower the glass transition temperature of the interlayer while increasing the complex viscosity of the interlayer at 200°C, for example, 0% by mass or more and 11.5% by mass or less, preferably 3% by mass or more and 10% by mass or less, more preferably 4% by mass or more and 9% by mass or less, even more preferably 5% by mass or more and 8% by mass or less, and even more preferably 6% by mass or more and 8% by mass or less, based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin. Furthermore, in the third embodiment, from the viewpoint of increasing transparency, increasing the glass transition temperature, and keeping the Pammel value below a certain level, the content of constituent unit (A) derived from (meth)acrylic acid is, for example, 0% by mass or more and 11.5% by mass or less, preferably 3% by mass or more and 10% by mass or less, more preferably 4% by mass or more and 9% by mass or less, even more preferably 4.5% by mass or more and 9% by mass or less, and even more preferably 5% by mass or more and 9% by mass or less, based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin.

[0067] As described above, in the first and second embodiments, the ionomer resin may contain constituent units (D) derived from alkyl (meth)acrylate. Similarly, in the third embodiment, the ionomer resin may also contain constituent units (D) derived from alkyl (meth)acrylate, from the viewpoint of improving both the transparency and flexibility of the interlayer. In each embodiment, from the viewpoint of not lowering the glass transition temperature of the interlayer more than necessary, the content of constituent units (D) derived from alkyl (meth)acrylate is preferably 11.5% by mass or less, more preferably 8% by mass or less, even more preferably 4.5% by mass or less, and even more preferably 2% by mass or less, based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin. Furthermore, from the viewpoint of increasing rigidity at high temperatures without lowering the glass transition temperature, the less the content of constituent units (D), the better, and it is preferable that the ionomer resin does not contain constituent units (D).

[0068] Furthermore, while isobutyl (meth)acrylate, and especially isobutyl acrylate, is generally preferred as the alkyl (meth)acrylate in ionomer resins, in each embodiment of the present invention, it is preferable that the ionomer resin does not contain any constituent units derived from isobutyl (meth)acrylate, or contains only a small amount. Therefore, in the interlayer film, the content of constituent units derived from isobutyl (meth)acrylate is preferably 11.5% by mass or less, more preferably 8% by mass or less, even more preferably 4.5% by mass or less, and even more preferably 2% by mass or less, relative to the total content of the ethylene-(meth)acrylic acid copolymer and its ionomer resin. Moreover, the content of constituent units derived from isobutyl (meth)acrylate may be 0% by mass or more, and it is preferable that the ionomer resin does not contain any constituent units derived from isobutyl (meth)acrylate.

[0069] The degree of neutralization can be determined from IR measurements before and after hydrochloric acid treatment. The specific measurement method is as described in the examples below. Furthermore, the content of each constituent unit in the interlayer film can be determined by mass spectrometry and １ This can be calculated by performing 1H-NMR measurements and analyzing the integrated intensity ratio of the hydrogen peaks originating from each monomer, as well as the degree of neutralization.

[0070] [Silane Coupling Agent] In each embodiment, the interlayer may contain additives. In each embodiment, it is preferable that the interlayer contains, for example, a silane coupling agent as an additive. By containing a silane coupling agent, the interlayer can easily improve its adhesion to substrates, glass, etc., and for example, its Pammel value can easily be increased. A silane coupling agent is a compound having a Si atom, a reactive group Y selected from organic functional groups such as vinyl groups, epoxy groups, amino groups, (meth)acryloyl groups, and mercapto groups, and a hydrolysis group OR selected from methoxy groups, ethoxy groups, etc. (OR may all be the same or different, and n is 0 to 2), as shown in the general formula (1) below. More specifically, silane coupling agents include those having groups containing polymerizable carbon-carbon double bonds such as vinyl groups and (meth)acryloyl groups, organic functional groups such as amino groups and epoxy groups, and alkoxy groups. Of course, the interlayer does not have to contain a silane coupling agent.

[0071] Examples of silane coupling agents having polymerizable carbon-carbon double bonds include vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, and 3-acryloxypropyltriethoxysilane. Examples of silane coupling agents having an amino group include N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and hydrochloride salts of N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane. Examples of silane coupling agents having an epoxy group include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. The interlayer may contain one silane coupling agent alone, or it may contain two or more silane coupling agents.

[0072] Among these, silane coupling agents having an amino group are preferred from the viewpoint of improving adhesion to glass and substrates, and among them, silane coupling agents having an ethylenediamine structure such as N-(2-aminoethyl)-3-aminopropyltrimethoxysilane are preferred.

[0073] The content of the silane coupling agent in the interlayer film according to the first and second embodiments is, from the viewpoint of improving adhesion to glass and substrates, for example, 0.001% by mass or more, preferably 0.005% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.03% by mass or more, and also, for example, 1% by mass or less, preferably 0.5% by mass or less, more preferably 0.2% by mass or less, even more preferably 0.15% by mass or less, and even more preferably 0.1% by mass or less, when the entire interlayer film is considered as 100% by mass. The interlayer film according to the first and second embodiments does not necessarily have to contain a silane coupling agent. Therefore, the content of the silane coupling agent in the interlayer film according to the first and second embodiments is, for example, 0% by mass or more and 1% by mass or less, preferably 0.001% by mass or more and 0.5% by mass or less, more preferably 0.005% by mass or more and 0.2% by mass or less, even more preferably 0.01% by mass or more and 0.15% by mass or less, and even more preferably 0.03% by mass or more and 0.1% by mass or less, when the entire interlayer film is considered to be 100% by mass.

[0074] In the third embodiment, the content of the silane coupling agent in the interlayer film is, from the viewpoint of improving adhesion to glass and substrates, for example, 0.001% by mass or more, preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.03% by mass or more, when the entire interlayer film is considered to be 100% by mass. Furthermore, in the third embodiment, the content of the silane coupling agent in the interlayer film is, from the viewpoint of lowering the Pammel value, for example, 1% by mass or less, preferably 0.5% by mass or less, more preferably 0.3% by mass or less, even more preferably 0.2% by mass or less, even more preferably 0.15% by mass or less, and even more preferably 0.1% by mass or less, when the entire interlayer film is considered to be 100% by mass. Note that, from the viewpoint of lowering the Pammel value, the interlayer film does not need to contain a silane coupling agent. Therefore, the content of the silane coupling agent in the interlayer according to the third embodiment is, for example, 0% by mass or more and 1% by mass or less, preferably 0.001% by mass or more and 0.5% by mass or less, more preferably 0.005% by mass or more and 0.3% by mass or less, even more preferably 0.01% by mass or more and 0.2% by mass or less, even more preferably 0.03% by mass or more and 0.15% by mass or less, and even more preferably 0.03% by mass or more and 0.1% by mass or less, when the entire interlayer is considered to be 100% by mass.

[0075] [Additives] In each embodiment, the intermediate film may contain at least one of the following additives in addition to the silane coupling agent: an ultraviolet absorber, an antioxidant, and other known additives. Examples of ultraviolet absorbers include conventionally known ultraviolet absorbers such as compounds having a malonic acid ester structure, compounds having an oxalic acid anilide structure, compounds having a benzotriazole structure, compounds having a benzophenone structure, compounds having a triazine structure, compounds having a benzoate structure, and compounds having a hindered amine structure. One type of ultraviolet absorber may be used alone, or two or more types may be used in combination. The ultraviolet absorber absorbs ultraviolet rays contained in sunlight, etc., preventing the intermediate film from deteriorating due to irradiation with sunlight, etc., and improving durability. In each embodiment, the content of the ultraviolet absorber in the intermediate film is preferably 0.01% by mass or more and 3% by mass or less, more preferably 0.05% by mass or more and 2% by mass or less, and even more preferably 0.1% by mass or more and 1.5% by mass or less, based on 100% by mass of the entire intermediate film.

[0076] Examples of antioxidants include phenolic compounds, phosphoric acid compounds, and sulfur compounds. Antioxidants prevent oxidative degradation of the interlayer film, thereby improving durability. Antioxidants may be used individually or in combination of two or more types.

[0077] The interlayer may contain known additives other than those listed above, such as plasticizers, light stabilizers, antistatic agents, surfactants, colorants, foaming agents, lubricants, crystal nucleating agents, crystallization accelerators, crystallization retarders, catalyst deactivators, heat absorbers, heat reflectors, heat dissipators, inorganic fillers, organic fillers, impact resistance modifiers, slip agents, crosslinking agents, crosslinking aids, tackifiers, processing aids, mold release agents, hydrolysis inhibitors, antiblocking agents, antifogging agents, flame retardants, flame retardant aids, light diffusing agents, antibacterial agents, antifungal agents, dispersants, etc. From the viewpoint of design, it is preferable that the interlayer contains a colorant. From the viewpoint of transparency, it is preferable that the interlayer does not contain a colorant.

[0078] (Thickness) The thickness of the interlayer in each embodiment is not particularly limited, but is, for example, 0.2 mm or more and 7.6 mm or less, preferably 0.6 mm or more and 4.5 mm or less, more preferably 1.5 mm or more and 3.6 mm or less, and even more preferably 2.0 mm or more and 3.6 mm or less. Setting the thickness of the interlayer above a certain level makes it easier to improve resistance to high-speed impacts, for example, in the first and second embodiments, by increasing the puncture stroke. It also makes it easier to improve the bending rigidity of the interlayer. Furthermore, in the third embodiment, for example, setting the thickness of the interlayer above a certain level makes it easier to improve resistance to high-speed impacts. It also makes it easier to improve the bending rigidity and adhesion of the interlayer. Furthermore, by setting the thickness below the above upper limit in each embodiment, it is possible to prevent the interlayer from becoming unnecessarily thick, and it becomes easier to manufacture it in a general manner. It also makes it easier to ensure transparency.

[0079] The interlayers according to each embodiment of the present invention preferably have a width of 1 m or more. A width of 1 m or more allows the interlayer to be suitably used in large-format laminated glass and laminated glass for building structures. A width of 2 m or more is more preferable. The interlayer is not particularly limited, but from the viewpoint of improving productivity, a width of 5 m or less is preferable, and 4 m or less is more preferable. It is preferable that the interlayer is an extruded product obtained by extrusion molding, which will be described later. Being an extruded product makes it easy to industrially mass-produce large-format interlayers with a width of 1 m or more, as described above.

[0080] Each embodiment of the present invention consists of a single layer and is preferably composed of a single-layer film. The layers constituting the single-layer film may consist of a resin composition having the composition described above. That is, the layers constituting the single-layer film may consist of a resin composition containing a resin component such as an ionomer resin and, if necessary, additives as appropriate. Furthermore, each embodiment of the interlayer may also be a multilayer film of two or more layers. In a multilayer film, the overall composition of the interlayer may be as described above for the interlayer, but it is preferable that the resin composition constituting each layer has the composition described above for the interlayer. That is, each layer may consist of a resin composition containing a resin such as an ionomer resin and, if necessary, additives as appropriate, as described above for the interlayer. In a multilayer film, the compositions of each layer may be different from each other or the same. Furthermore, in the case of a multilayer film, as will be described later, multiple interlayers may be laminated together to form an interlayer of a multilayer film. Furthermore, in single-layer or multi-layer films, the content of ionomer resin, the content of other resin components, and the content of each additive in the resin composition constituting each layer may be as described above. However, while the standard for the content of each component described above was based on 100% by mass of the interlayer, in the resin composition constituting each layer, the standard for the content of each component shall be 100% by mass of the resin composition instead of 100% by mass of the interlayer.

[0081] [Method for Manufacturing Interlayer Films] In each embodiment, the interlayer film may be obtained by obtaining a resin composition for forming the interlayer film and then molding the interlayer film from the resin composition. If the interlayer film consists of one component, that component (i.e., a resin component such as an ionomer resin) may be appropriately heated and melted and formed into a film by extrusion molding, press molding, roll molding, etc. to form the interlayer film. If the resin composition consists of two or more components, the resin components and additives, which may be added as needed, may be mixed to obtain a resin composition, and the obtained resin composition may be appropriately heated and melted and formed into a film by extrusion molding, press molding, roll molding, etc. to obtain the interlayer film. The method for mixing each component to obtain the resin composition is not particularly limited, but a method of kneading using an extruder is preferred. If the interlayer film consists of multiple layers, resin compositions for forming each layer may be prepared, the obtained resin compositions may be appropriately heated and melted and formed into films by extrusion molding, press molding, roll molding, etc. to form each layer, and the interlayer film may be obtained by laminating each layer. If the interlayer film consists of multiple layers, co-extrusion may be used for extrusion molding. Among the above methods, the interlayer is preferably formed by extrusion molding. By employing extrusion molding, a wide interlayer can be efficiently manufactured. Furthermore, in each embodiment of the present invention, as shown in the method for manufacturing the laminate described later, multiple interlayers may be placed between two substrates and integrated between the two substrates to form a single interlayer.

[0082] The interlayer may be manufactured using a so-called masterbatch. The masterbatch consists of a mixture (hereinafter sometimes referred to as mixture (A)) obtained by mixing an additive with a resin component, and the resin component can be at least one of an ionomer resin and other resin components other than ionomer resins. The other resin component other than the ionomer resin is preferably one of the other resin components mentioned above, and more preferably an ethylene-(meth)acrylic acid copolymer. By using a masterbatch, the additive can be easily mixed with the ionomer resin. Furthermore, by including the other resin component such as an ethylene-(meth)acrylic acid copolymer in mixture (A), the viscosity of the resin composition is effectively reduced, making it possible to easily knead the resin composition in an extruder or the like. The additive contained in mixture (A) may be one or more selected from the above-mentioned additives, and preferably contains at least one of a silane coupling agent, an ultraviolet absorber, and an antioxidant, but may also contain other additives. The form of mixture (A) is not particularly limited, but is typically in the form of particles such as pellets.

[0083] In each embodiment, the interlayer is preferably used by being placed between two substrates, and more preferably used as a laminate, as will be described later. The interlayer may also be used to bond two components, i.e., two substrates, together. The interlayer is particularly preferably a laminated glass interlayer used in laminated glass. The two substrates may be the same or different.

[0084] <Laminate> Each embodiment of the present invention comprises an interlayer and two substrates, wherein the interlayer is placed between the two substrates. The two substrates may be the same or different. In the laminate, the two substrates are preferably bonded together via the interlayer. In the laminate, the interlayer placed between the two substrates may be a single layer, or multiple interlayers may be placed and integrated between the two substrates to form a single interlayer. By placing multiple interlayers between the two substrates, even when it is necessary to increase the thickness of the interlayer between two glass sheets, such as in laminated glass for building structures, this can be accommodated with an interlayer of a general-purpose thickness. The multiple interlayers are preferably integrated between the substrates, and the two substrates are preferably bonded together via the integrated interlayer. The total thickness of the interlayer film between substrates in the laminate is not particularly limited, but is, for example, 0.2 mm or more and 7.6 mm or less, preferably 0.6 mm or more and 4.5 mm or less, more preferably 1.5 mm or more and 3.6 mm or less, and even more preferably 2.0 mm or more and 3.6 mm or less.

[0085] A separate layer may be provided between the interlayer and the substrate, but it is preferable that no separate layer is provided and the interlayer is in direct contact with the substrate. Furthermore, when using multiple interlayers, a separate layer may be provided between the multiple interlayers, but it is preferable that no separate layer is provided and the interlayers are directly bonded to each other to form a single integrated interlayer. Examples of the separate layer include resin films other than the interlayer of the present invention described above.

[0086] The substrates used in laminates include resin films and glass, but glass is preferred among these. By using glass as both substrates in a laminate, the laminate becomes laminated glass.

[0087] Examples of resin films used as substrates include polyester resin films such as (meth)acrylic resin films, polycarbonate films, polyethylene terephthalate (PET) films, and polyethylene naphthalate (PEN) films, as well as polyolefin resin films such as polyethylene films and polypropylene films, cyclic polyolefin (COP) films, triacetylcellulose (TAC) films, polyethersulfone (PES) resin films, and polyimide resin films. The resin film may consist of a single layer or two or more layers laminated together. Functional layers such as a hard coat layer may be provided on the surface of the resin film as appropriate, and electrodes, sensors, etc., may be attached. The thickness of the resin film used as a substrate is not particularly limited, but is preferably 30 μm or more, more preferably 50 μm or more, and also, for example, 1 mm or less, but preferably 500 μm or less, and more preferably 450 μm or less.

[0088] Furthermore, glass sheets can be used as the glass. The glass sheets may be either inorganic glass or organic glass, but inorganic glass is preferred. Inorganic glass is not particularly limited, but examples include clear glass, float glass, tempered float glass and other types of tempered glass, colored glass, polished glass, patterned glass, wired glass, reinforced glass, ultraviolet absorbing glass, infrared reflective glass, infrared absorbing glass, green glass, etc. Among these, float glass is preferred from the viewpoint of versatility, and tempered glass is preferred from the viewpoint of high resistance to high-speed impact. As for organic glass, what is generally called resin glass is used, and is not particularly limited, but examples include organic glass composed of polycarbonate sheets, polymethyl methacrylate sheets, polyester sheets, etc. The two glass sheets may be composed of the same material or of different materials. For example, one may be inorganic glass and the other may be organic glass, but it is preferable that both glass sheets are inorganic glass or organic glass, and it is more preferable that both glass sheets are inorganic glass. The thickness of each of the above-mentioned glass elements is not particularly limited, but is, for example, 0.5 mm to 20 mm, preferably 1 mm to 15 mm, more preferably 2 mm to 12 mm, and even more preferably 3 mm to 10 mm. By setting the thickness of the glass to a certain value or higher, it becomes easier to improve the resistance of the laminate to high-speed impacts. Also, by setting the thickness to below the above upper limit, it is possible to prevent the laminate from becoming unnecessarily thick.

[0089] In one embodiment of the first aspect of the present invention, the laminate has a puncture stroke of 18.6 mm or more in a puncture impact test, and the interlayer has a glass transition temperature of 50°C or more as described above. The laminate having the above configuration can ensure high static rigidity over a wide temperature range while providing good resistance to high-speed impacts. In the first embodiment, the puncture stroke of the laminate is preferably 19.5 mm or more, and more preferably 21.0 mm or more. The upper limit of the puncture stroke is not particularly limited and may be, for example, 35 mm or 30 mm. In the first embodiment, the higher the puncture energy of the laminate, the better; for example, 40 J or more is sufficient, preferably 60 J or more, more preferably 70 J or more, and even more preferably 75 J or more. The puncture stroke and puncture energy of the laminate are values ​​measured by performing a puncture impact test on the laminate. The conditions for the puncture impact test are as described above, and the details of the test method are as described in the examples. Furthermore, the glass transition temperature of the interlayer is as described above, and a detailed explanation is omitted.

[0090] Furthermore, if the laminate is laminated glass, the Pammel value of the laminated glass according to the first embodiment may be 1 or more and 9 or less, but from the viewpoint of improving adhesion, a higher Pammel value is preferable, preferably 3 or more and 9 or less, more preferably 5 or more and 9 or less, and even more preferably 7 or more and 9 or less. Note that the Pammel value is a value measured relative to the laminated glass. Details of the method for measuring the Pammel value are shown in the examples.

[0091] Furthermore, in one embodiment of the second embodiment of the present invention, the laminate comprises an interlayer and two substrates, wherein the interlayer is positioned between the two substrates, the glass transition temperature of the interlayer is 50°C to 65°C, and the complex viscosity of the interlayer, measured at a measurement temperature of 200°C and a frequency of 1 Hz, is 800 Pa·s or more. A laminate having the above configuration can ensure high static rigidity over a wide temperature range while providing good resistance to high-speed impacts.

[0092] In the second embodiment, the glass transition temperature of the interlayer in the laminate, the measurement temperature of 200°C, and the complex viscosity of the interlayer measured at a frequency of 1 Hz are the same as those of the interlayer according to the second embodiment of the present invention, so their explanation will be omitted.

[0093] In the puncture impact test of the laminate according to the second embodiment of the present invention, the higher the puncture energy, the better; for example, 50 J or more is preferable, preferably 70 J or more, more preferably 75 J or more, and even more preferably 78 J or more. Furthermore, the puncture stroke in the puncture impact test is preferably 18.6 mm or more, preferably 19.5 mm or more, and more preferably 21.0 mm or more. The upper limit of the puncture stroke is not particularly limited; for example, it may be 35 mm or 30 mm.

[0094] In the case where the laminate according to the second embodiment is laminated glass, the Pammel value of the laminated glass may be, for example, 1 or more and 9 or less, but from the viewpoint of improving adhesion, a higher Pammel value is preferable, preferably 3 or more and 9 or less, more preferably 5 or more and 9 or less, and even more preferably 7 or more and 9 or less. Note that the Pammel value is a value measured relative to the laminated glass. Details of the method for measuring the Pammel value are shown in the examples.

[0095] Furthermore, in one aspect of the third embodiment of the present invention, the laminate has a Pummel value of less than 9.0, and the interlayer in the laminate has a glass transition temperature of 58°C or higher as described above. A laminate having the above configuration can ensure high static rigidity over a wide temperature range while providing good resistance to high-speed impact. In one aspect of the third embodiment, the Pummel value of the laminate is preferably 8.5 or less, more preferably 8.0 or less, and even more preferably 7.5 or less. Also, from the viewpoint of preventing delamination, foaming, etc., the Pummel value of the laminate is preferably 1 or more, preferably 3 or more, even more preferably 5 or more, and even more preferably 7 or more. Note that the Pummel value is a value measured relative to the laminate. The measurement conditions for the Pummel value are as described above, and the details of the test method are as described in the examples. Furthermore, the glass transition temperature of the interlayer in one aspect of the third embodiment is as described above, and a detailed explanation thereof is omitted.

[0096] (Method for Manufacturing Laminates) Laminates according to each embodiment of the present invention can be manufactured, for example, by preparing two substrates and one or more interlayer films, placing one or more interlayer films or multiple overlapping interlayer films between the two substrates, and then pressing them together. If the laminate has another layer other than the interlayer film of the present invention, a resin film or the like that constituting the other layer may be placed together with the interlayer film between the two substrates. The pressing is not particularly limited, but it is preferable to press while heating. Alternatively, pre-bonding may be performed at a relatively low pressure and temperature, and then the final bonding may be performed at a higher pressure, temperature, or both than the pre-bonding. When multiple interlayer films are placed between two substrates, it is preferable to integrate the multiple interlayer films during the pressing process.

[0097] Furthermore, in the case of laminated glass, for example, one or more interlayer films are placed between two sheets of glass, and the air remaining between the two sheets of glass and the interlayer film is removed by passing them through a pressure roll or by placing them in a rubber bag and applying reduced pressure and suction. Then, a laminated intermediate is obtained by pre-bonding at approximately 70 to 110°C. Next, the laminated intermediate is placed in an autoclave or pressed and bonded at approximately 120 to 150°C and a pressure of 1 to 1.5 MPa to complete the bonding process. In this way, laminated glass can be obtained. When multiple interlayer films are placed between two sheets of glass, it is preferable to integrate the multiple interlayer films by either pre-bonding or complete bonding.

[0098] The interlayers and laminates according to each embodiment of the present invention can be used in a variety of fields, including electronic devices such as displays, vehicles such as automobiles, railway vehicles, aircraft, and ships, and various building structures such as buildings, apartments, detached houses, halls, and gymnasiums. Among these, use in vehicles and building structures is preferred, and use in building structures is more preferred. In vehicles and building structures, it is preferable to use laminated glass. In vehicle applications, it is often used as window glass; for example, in automobiles, it can be used as the windshield, rear window, or side window. In building structures, it can be used as window glass, glass floor, curtain wall, etc. Laminated glass may be made into large sheets or used as structural glazing, but in the present invention, as described above, it has high static rigidity and resistance to high-speed impact, so it can be suitably used in building structures.

[0099] The present invention will be described in more detail by reference to examples, but the present invention is not limited in any way by these examples.

[0100] <First Embodiment> First, an embodiment according to the first embodiment will be described. The measurement and evaluation of various physical properties were performed as follows. Unless otherwise specified, the terms used herein are defined by the measurement and evaluation methods described below.

[0101] [Thickness of the intermediate film] The thickness of the intermediate film was measured by averaging 10 points using a microscope "DSX500" manufactured by Olympus Corporation.

[0102] [Content and neutralization degree of each constituent unit] The mass percentages of each constituent unit in the ethylene-(meth)acrylic acid copolymer and its ionomer resin were determined after performing the following hydrochloric acid treatment. １ H-NMR and IR measurements were performed. In addition, for the measurement of the content and neutralization degree of each of the following constituent units, when the intermediate film contains an ethylene-unsaturated carboxylic acid copolymer and its ionomer resin, a mixture obtained by mixing these at the blending ratio in each intermediate film was used as the sample. Also, when no ethylene-unsaturated carboxylic acid copolymer is contained and only the ionomer resin is used, the ionomer resin used in each intermediate film was used as the sample. (Hydrochloric acid treatment) For 100 mg of the sample cryogenically pulverized using JFC-2000 (manufactured by Nippon Analytical Industry Co., Ltd.), 500 μL of ethanol and 1 mL of hydrochloric acid were added, and the mixture was stirred at 60 °C for 48 hours. Then, it was washed three times with ultrapure water to remove hydrochloric acid, and dried by heating.

[0103] (Neutralization degree) The neutralization degree was determined by performing IR measurements on the samples before and after the hydrochloric acid treatment. Based on the peak height of methylene at 1460 cm －１ before and after the hydrochloric acid treatment, it was calculated by the following formula from the peak height of carboxylic acid at 1700 cm －１ . In the following formula, the denominator represents the peak height at 1700 cm －１ / the peak height at 1460 cm －１ of the sample after the hydrochloric acid treatment, and the numerator represents the peak height at 1700 cm －１ / the peak height at 1460 cm －１ of the sample before the hydrochloric acid treatment.

[0104] ( １ H-NMR measurement) The sample after the hydrochloric acid treatment was dissolved in a solvent (tetrachloroethane:dimethyl sulfoxide = 5:2) to a concentration of about 1 to 3% by mass to prepare a measurement solution. Regarding the measurement solution １¹H-NMR measurements were performed (instrument: AVANCE 400 (PRODIGY), spectrometer: AVANCE III HD). The measurement conditions were 8 cumulative measurements at a temperature of 120°C. In the analysis, the integral value of H originating from the methyl group of methacrylic acid was used as the reference value, set to 3.00. At that time, the total mass % of constituent units (A) and (B) and the mass % of constituent unit (C) derived from ethylene were calculated from the integral intensity ratio of the H peaks originating from methylene that appear between 1.15 and 1.62 ppm. Furthermore, the respective contents of constituent units (A) and (B) were calculated from the degree of neutralization.

[0105] [Complex Viscosity] 1 g of interlayer film was placed in a mold (2 cm long x 2 cm wide x 0.76 mm thick) positioned between two polyethylene terephthalate (PET) films, at a temperature of 150°C and a press pressure of 0 kg / cm². ２ After preheating for 10 minutes, set the temperature to 150°C and the load capacity to 80 kg / cm². ２ The interlayer was press-molded for 15 minutes. Then, the press-molded interlayer was placed in a hand press machine pre-set to 20°C and cooled by pressing at 10 MPa for 10 minutes. Next, one PET film was peeled from the mold placed between the two PET films and stored for 24 hours in a constant temperature and humidity chamber (humidity 30% (±3%) RH, temperature 23°C). Viscoelasticity was then measured and complex viscosity was determined using an ARES-G2 manufactured by TA INSTRUMENTS, in accordance with JIS K7244-10 (ISO 6721-10). An 8 mm diameter parallel plate was used as a jig for viscoelasticity measurement. Viscoelasticity measurements were performed at a measurement temperature of 200°C, with a frequency of 1 Hz and a strain of 5%. In the case of multilayer interlayers, the layers constituting the interlayer were separated, and the complex viscosity of each layer was measured. The highest complex viscosity was taken as the complex viscosity of the interlayer.

[0106] [Glass Transition Temperature (Tg)] The glass transition temperature (Tg) was measured by DMA (dynamic viscoelasticity measurement). Specifically, the interlayer films obtained in the examples and comparative examples were cut to a length of 10 mm and a width of 5 mm, and their viscoelasticity was measured using a dynamic viscoelasticity measuring device (TA Instruments Co., Ltd., product name "ARES-G2") under the following measurement conditions. The sample was placed under conditions of 100°C, and viscoelasticity measurements were performed while the temperature was decreased, and the peak temperature of the loss tangent tanδ obtained from the results was read. Among the above peak temperatures in the temperature range of 0 to 100°C, the peak temperature at which tanδ was at its maximum value was defined as the glass transition temperature. In the case of a multilayer interlayer film, the layers constituting the interlayer film were separated, and the glass transition temperature of each layer was measured, and the highest glass transition temperature was defined as the glass transition temperature of that interlayer film. (Measurement conditions) Deformation mode: shear mode, Measurement temperature: temperature decrease from 100°C to 0°C, Cooling rate: 3°C / min, Measurement frequency: 1 Hz, Strain: 1%, 8 mm parallel plate

[0107] [Pammel Value] The obtained laminated glass was left to stand for 16 hours at a temperature of 23°C ± 0.6°C and a humidity of 25 ± 5% RH. After standing, the central part of the laminated glass (150 mm x 150 mm) was struck with a hammer with a head of 0.45 kg until the glass particle size was 6 mm or less. The other side was struck with the hammer the same number of times. The degree of exposure of the film after partial delamination of the glass was measured, and the pammel value was determined according to Table 1 below. Measurements were performed on two pieces of laminated glass for each example, and the average value was calculated by taking the arithmetic mean of the four values ​​obtained from the measurement: the pammel value of the surface and the pammel value of the back surface. The pammel value is a value that examines the degree of adhesion between the interlayer and the glass plate, and is defined by the degree of exposure (area %) of the film after partial delamination of the glass, as defined in Table 1. A higher pammel value indicates higher adhesion of the interlayer.

[0108] [Puncture Impact Test] A puncture impact test was conducted using the "HITS-PX High-Speed ​​Impact Tester" manufactured by Shimadzu Corporation as the measuring device. The measurement conditions for the puncture impact test are as follows: <Measurement Conditions> Striker diameter: φ20 mm Striker tip shape: φ20 mm cylindrical shape (contact surface is flat) Receiving-holding plate diameter: φ100 mm Set speed: 10 m / sec Sampling interval: 0.5 μsec Temperature: 25°C The puncture point was determined in accordance with JIS K7211-2:2006, and was defined as the point in the force-stroke diagram obtained by the puncture impact test where the test force decreased to half of the maximum test force. The maximum test force was defined as the maximum test force in the force-stroke diagram where the test force of the interlayer increased, and the interlayer was destroyed, causing the test force to decrease. For example, in the force-stroke diagram shown in Figure 2, the circled portion was defined as the maximum test force. The stroke value at the puncture point was defined as the puncture stroke. Furthermore, the integral value of the force-stroke diagram from the start point of the test to the puncture point was defined as the puncture energy. The puncture impact test was conducted using the following procedure: 1. Set the test specimen in the clamp. 2. Clamp the test specimen. (Air pressure during clamping is 0.7 MPa) 3. Apply oil to the striker. 4. Check that the punch at the tip of the striker is not loose. 5. Close the constant temperature chamber door of the testing machine to prevent scattering. 6. Conduct the test. 7. Collect the test specimen. 8. Clean the clamp and striker. 9. Return to "1".

[0109] [Bending Stiffness] The bending stiffness of laminated glass was evaluated using the test method schematically shown in Figure 1. As the measuring device, an Instron "Type 5965 Universal Tester" fitted with a three-point bending test fixture was used. The measurement conditions were as follows: distance D1 between supports was 13.2 cm, sample length D2 was 20 cm, width was 8 cm, and the sample thickness was the value measured for each sample. Deformation was applied to the laminated glass 20 in the direction F at a displacement rate of 1 mm / min, and the stress was measured when either a displacement of 0.6 mm was reached or a force of 500 N was applied, and the bending stiffness was calculated. When calculating the bending stiffness, data with an indentation depth of 0.2 mm or more was used. The bending stiffness was measured in environments of 25°C and 50°C. Three samples were prepared at each level, the bending stiffness of each was measured, and the arithmetic mean of the three was used. The bending stiffness (N / mm) is the slope of the straight line on a graph plotted with the indentation depth (mm) on the horizontal axis and the load (N) on the vertical axis. The laminated glass obtained in each example and comparative example was cured for one week after manufacturing by being left in an environment of 23°C and 50% RH before the bending stiffness was measured. A bending stiffness of 1000 N / mm or more at 25°C was judged as "A", and a bending stiffness of less than 1000 N / mm was judged as "B". Similarly, a bending stiffness of 700 N / mm or more at 50°C was judged as "A", and a bending stiffness of less than 700 N / mm was judged as "B".

[0110] (Ratio of stiffness reduction) The ratio of stiffness reduction was determined from the bending stiffness of the laminated glass at 25°C and 50°C, and evaluated for each example and comparative example. The ratio of stiffness reduction was calculated using the following formula: Ratio of stiffness reduction (%) = [(Bending stiffness at 25°C - Bending stiffness at 50°C) / Bending stiffness at 25°C] × 100 A ratio of 50% or less was judged as "A", and a ratio exceeding 50% was judged as "B".

[0111] [Missile Test] Missile tests were conducted in accordance with the "Test Method for Impact of Flying Objects on Architectural Glass in Stormy Weather" specified in JIS R 3109:2018. Tests were performed on impactors C, JD, and D. Those that passed the impact test were marked OK, and those that failed were marked NG. Pressure loading tests were not performed. Those that passed all impactors were marked "AA", those that did not pass impactor D but passed impactors C and JD were marked "A", and those that failed impactor C or JD were marked "B".

[0112] [Overall Assessment] For bending stiffness, stiffness reduction rate, and missile testing, if all assessment results were "AA" or "A", the overall assessment was given as "A". If at least one result was "B", the overall assessment was given as "B".

[0113] The components used in the following examples and comparative examples were as follows: Ionomer 1A: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions. In the ionomer resin, constituent units (A) derived from methacrylic acid = 6.1% by mass, constituent units (B) derived from neutralized methacrylic acid = 11.8% by mass, and constituent units (C) derived from ethylene = 82.1% by mass, degree of neutralization = 73%. Ionomer 2A: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with sodium ions. In the ionomer resin, constituent units (A) derived from methacrylic acid = 9.7% by mass, constituent units (B) derived from neutralized methacrylic acid = 10.5% by mass, and constituent units (C) derived from ethylene = 79.8% by mass, degree of neutralization = 52% Copolymer 1A: Ethylene-methacrylic acid copolymer, constituent units (A) derived from methacrylic acid = 17.9% by mass, and constituent units (C) derived from ethylene = 82.1% by mass Silane coupling agent (SiCp): "KBM-602", manufactured by Shin-Etsu Chemical Co., Ltd., N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane

[0114] [Example 1A] (Preparation of interlayer film) 90 parts by mass of ionomer 1A, 10 parts by mass of ethylene-methacrylic acid copolymer, and 0.05 parts by mass of silane coupling agent were placed in an extruder, kneaded at 170°C, and extruded to obtain an interlayer film with a thickness of 0.76 mm and a width of 2.0 m.

[0115] (Preparation of Laminated Glass) Two sheets of glass (15 cm long x 15 cm wide x 2.75 mm thick (measured value, nominal value 3 mm), float glass (manufactured by Sanshiba Glass Materials Co., Ltd.)) and three interlayer films measuring 15 cm long x 15 cm wide x 0.76 mm thick were prepared. The three interlayer films were sandwiched between the two sheets of float glass to obtain a laminated intermediate. This laminated intermediate was placed in a rubber bag and degassed at a vacuum of 0.08 MPa for 20 minutes. Then, while still degassed, it was transferred to an oven and held at 90°C for 30 minutes to vacuum press and temporarily bond the laminated intermediate. The temporarily bonded laminated intermediate was pressed in an autoclave at 140°C and a pressure of 1.3 MPa for 20 minutes to obtain laminated glass in which two sheets of glass were bonded together with an interlayer film with a thickness of 2.28 mm. A puncture test was performed using the obtained laminated glass. In the fabrication of the laminated glass, the bottom surface (tin side) of each float glass sheet was adjusted to serve as the bonding surface with the interlayer. Furthermore, the laminated glass was fabricated in the same manner as described above, except that 5mm thick float glass (manufactured by Sanshiba Glass Co., Ltd.) was used as the glass material, and missile tests were conducted in accordance with JIS R 3109:2018.

[0116] (Preparation of laminated glass for Pammel value measurement) Two pieces of float glass (manufactured by Sanshiba Glass Co., Ltd.) measuring 30 cm in length, 15 cm in width, and 2.75 mm in thickness (measured value, nominal value 3 mm) were prepared, along with one interlayer measuring 30 cm in length, 15 cm in width, and 0.76 mm in thickness. The interlayer was sandwiched between the two pieces of float glass to obtain a laminated intermediate. Subsequently, laminated glass was prepared using the same method as described above, and the Pammel value was measured using the obtained laminated glass. In the preparation of the laminated glass for Pammel value measurement, the bottom surface (tin side) of each float glass was adjusted to become the bonding surface with the interlayer. Note that the Pammel value does not change even if the thickness of the interlayer is changed, so the value for an interlayer thickness of 0.76 mm is shown as a reference value.

[0117] (Preparation of Laminated Glass for Bending Stiffness Measurement) Two pieces of float glass (manufactured by Sanshiba Glass Co., Ltd.) measuring 20 cm in length, 8 cm in width, and 2.75 mm in thickness were prepared, along with three interlayer films measuring 20 cm in length, 8 cm in width, and 0.76 mm in thickness. The three interlayer films were sandwiched between the two pieces of float glass to obtain a laminated intermediate. Subsequently, laminated glass was prepared using the same method as described above, and the bending stiffness was measured using the obtained laminated glass. In the preparation of the laminated glass for bending stiffness measurement, the bottom surface (tin side) of each float glass was adjusted to become the bonding surface with the interlayer film.

[0118] [Example 2A] The procedure was carried out in the same manner as in Example 1A, except that 95 parts by mass of ionomer 1A and 5 parts by mass of ethylene-methacrylic acid copolymer were put into the extruder when preparing the interlayer film.

[0119] [Comparative Example 1A] The procedure was the same as in Example 1A, except that only ionomer 2A was put into the extruder when preparing the interlayer film.

[0120] [Comparative Examples 2A to 4A] In Comparative Examples 2A to 4A, interlayers with a thickness of 0.76 mm were prepared using the same methods as in Examples 1A, 2A, and Comparative Example 1A. In each comparative example, instead of three interlayers, one interlayer was sandwiched between two sheets of float glass, and laminated glass for puncture testing, missile testing, and bending stiffness measurement was prepared in the same manner as in Examples 1A, 2A, and Comparative Example 1A. Furthermore, the Pummel value was measured by preparing laminated glass by bonding two sheets of glass together using one interlayer with a thickness of 0.76 mm, in the same manner as in Examples 1A, 2A, and Comparative Example 1A.

[0121] [Comparative Example 5A] Laminated glass was prepared in the same manner as in Comparative Example 2A, except that a polyvinyl butyral resin sheet (Eastman Corporation, product name DG-41, thickness 0.76 mm) was used as the interlayer.

[0122] *The Pammel values ​​for Examples 1A, 2A, and Comparative Example 1A are data obtained when the interlayer thickness is 0.76 mm, and are shown as reference values.

[0123] In each of the above examples, the puncture stroke value was high and the glass transition temperature was also high, resulting in sufficiently high bending stiffness at 25°C and 50°C, a low rate of bending stiffness reduction, and high static stiffness over a wide temperature range. Furthermore, the results of the missile test were also good, and resistance to high-speed impact was good. In contrast, in Comparative Examples 1A and 5A, although the puncture stroke value was high, the glass transition temperature was low, resulting in low bending stiffness at 50°C and a high rate of bending stiffness reduction, as well as low bending stiffness at 25°C and 50°C, making it impossible to ensure high static stiffness over a wide temperature range. In Comparative Examples 2A and 3A, although the glass transition temperature was high, the puncture stroke value was low, making it impossible to obtain good results in the missile test. In Comparative Example 4A, both the glass transition temperature and puncture stroke values ​​were low, resulting in low bending stiffness at 50°C and a high rate of bending stiffness reduction, making it impossible to ensure high static stiffness over a wide temperature range, and furthermore, the results of the missile test were also unsatisfactory.

[0124] <Second Embodiment> Next, an embodiment according to the second embodiment will be described. The measurement and evaluation of various physical properties were carried out in the same manner as in the embodiment according to the first embodiment. However, the missile test was omitted. In addition, for the evaluation of the bending stiffness reduction rate, a stiffness reduction rate of 45% or less was evaluated as "A", a rate between 45% and 50% was evaluated as "B", and a rate above 50% was evaluated as "C". In addition, for the evaluation of puncture energy, 78 J or more was evaluated as "A", 75 J or more and less than 78 J was evaluated as "B", and less than 75 J was evaluated as "C". Furthermore, the overall evaluation in the second embodiment was carried out as follows.

[0125] [Overall Judgment] For stiffness reduction rate and puncture energy, the overall judgment was "A" for all judgment results, the overall judgment was "B" for those with at least one judgment result of "B" and no judgment results of "C", and the overall judgment was "C" for those with at least one judgment result of "C".

[0126] The components used in the examples and comparative examples of the second embodiment were as follows: Ionomer 1B: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions. In the ionomer resin, constituent units (A) derived from methacrylic acid = 6.1% by mass, constituent units (B) derived from neutralized methacrylic acid = 11.8% by mass, and constituent units (C) derived from ethylene = 82.1% by mass, degree of neutralization = 73% Ionomer 2B: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with sodium ions. In the ionomer resin, constituent units (A) derived from methacrylic acid = 9.7% by mass, constituent units (B) derived from neutralized methacrylic acid = 10.5% by mass, and constituent units (C) derived from ethylene = 79.8% by mass, degree of neutralization = 52% Ionomer 3B: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions. In the ionomer resin, constituent units (A) derived from methacrylic acid = 5.5% by mass, constituent units (B) derived from neutralized methacrylic acid = 14.2% by mass, and constituent units (C) derived from ethylene = 80.3% by mass, degree of neutralization = 72% Ionomer 4B: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions. In the ionomer resin, constituent units (A) derived from methacrylic acid = 6.4% by mass, constituent units (B) derived from neutralized methacrylic acid = 12.4% by mass, and constituent units (C) derived from ethylene = 81.2% by mass, degree of neutralization = 66% Ionomer 5B: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions. In the ionomer resin, constituent units (A) derived from methacrylic acid = 7.7% by mass, constituent units (B) derived from neutralized methacrylic acid = 11.2% by mass, and constituent units (C) derived from ethylene = 81.1% by mass, degree of neutralization = 59%. Ionomer 6B: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions.In the ionomer resin, constituent units (A) derived from methacrylic acid = 4.3% by mass, constituent units (B) derived from neutralized methacrylic acid = 14.5% by mass, and constituent units (C) derived from ethylene = 81.2% by mass, degree of neutralization = 77% Copolymer 1B: Ethylene-methacrylic acid copolymer, constituent units (A) derived from methacrylic acid = 19.7% by mass, and constituent units (C) derived from ethylene = 80.3% by mass Silane coupling agent (SiCp): "KBM-602", manufactured by Shin-Etsu Chemical Co., Ltd., N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane.

[0127] [Example 1B] 90 parts by mass of ionomer 3B and 10 parts by mass of ethylene-methacrylic acid copolymer were placed in an extruder, kneaded at 170°C, and extruded to obtain an interlayer film with a thickness of 0.76 mm and a width of 2.0 m.

[0128] (Laminated Glass Fabrication) Two sheets of glass (15 cm long x 15 cm wide x 2.75 mm thick (measured value, nominal value 3 mm), float glass) and three interlayer films measuring 15 cm long x 15 cm wide x 0.76 mm thick were prepared. The three interlayer films were sandwiched between the two sheets of float glass to obtain a laminated intermediate. This laminated intermediate was placed in a rubber bag and degassed at a vacuum of 0.08 MPa for 20 minutes. Then, while still degassed, it was transferred to an oven and held at 90°C for 30 minutes to vacuum press and temporarily bond the laminated intermediate. The temporarily bonded laminated intermediate was pressed in an autoclave at 140°C and a pressure of 1.3 MPa for 20 minutes to obtain laminated glass with two sheets of glass bonded together by an interlayer film with a thickness of 2.28 mm. A puncture test was performed using the obtained laminated glass. Furthermore, in the fabrication of the laminated glass, the bottom surface (tin side) of each float glass plate was adjusted to become the bonding surface with the interlayer.

[0129] (Preparation of laminated glass for Pammel value measurement) Two pieces of float glass measuring 30 cm in length, 15 cm in width, and 2.75 mm in thickness (measured value, nominal value 3 mm) were prepared, along with one interlayer measuring 30 cm in length, 15 cm in width, and 0.76 mm in thickness. The interlayer was sandwiched between the two pieces of float glass to obtain a laminated intermediate. Subsequently, laminated glass was prepared using the same method as described above, and the Pammel value was measured using the obtained laminated glass. In the preparation of the laminated glass for Pammel value measurement, the bottom surface (tin side) of each piece of float glass was adjusted to become the bonding surface with the interlayer.

[0130] (Preparation of Laminated Glass for Bending Stiffness Measurement) Two pieces of float glass (manufactured by Sanshiba Glass Co., Ltd.) measuring 20 cm in length, 8 cm in width, and 2.75 mm in thickness were prepared, along with three interlayer films measuring 20 cm in length, 8 cm in width, and 0.76 mm in thickness. The three interlayer films were sandwiched between the two pieces of float glass to obtain a laminated intermediate. Subsequently, laminated glass was prepared using the same method as described above, and the bending stiffness was measured using the obtained laminated glass. In the preparation of the laminated glass for bending stiffness measurement, the bottom surface (tin side) of each float glass was adjusted to become the bonding surface with the interlayer film.

[0131] [Examples 2B to 5B and Comparative Examples 1B to 6B] The procedure was carried out in the same manner as in Example 1B, except that the amounts of ionomer 1B, ionomer 2B, ionomer 3B, ionomer 4B, ionomer 5B, ionomer 6B, copolymer 1, and silane coupling agent were changed as shown in Table 3 when preparing the interlayer film.

[0132]

[0133] The interlayers of Examples 1B to 5B had a glass transition temperature of 50°C to 65°C, and a complex viscosity of 800 Pa·s or higher measured at a temperature of 200°C and a frequency of 1 Hz. Therefore, the rate of stiffness reduction was small, and the puncture energy was large. This indicates that the interlayers of Examples 1B to 5B can ensure high static stiffness over a wide temperature range while exhibiting good resistance to high-speed impacts. The interlayers of Comparative Examples 1B, 4B, and 5B had glass transition temperatures greater than 65°C, resulting in low puncture energy. Therefore, it was found that the interlayers of Comparative Examples 1B, 4B, and 5B did not exhibit sufficiently high resistance to high-speed impacts. The interlayers of Comparative Examples 2B and 3B had complex viscosity less than 800 Pa·s measured at a temperature of 200°C and a frequency of 1 Hz. Therefore, it was found that the interlayers of Comparative Examples 2B and 3B could not ensure high static stiffness over a wide temperature range, and their resistance to high-speed impacts was not sufficiently high.

[0134] <Third Embodiment> Next, an embodiment according to the third embodiment will be described. The measurement and evaluation of various physical properties were carried out in the same manner as in the first embodiment, except for the penetration resistance test described below. However, the missile test and puncture test were omitted. Furthermore, for the evaluation of bending stiffness, a bending stiffness of 1000 N / mm or more at 25°C was judged as "A", and a stiffness of less than 1000 N / mm was judged as "B". Furthermore, for the evaluation of the stiffness reduction rate, a stiffness reduction rate of 50% or less was judged as "A", and a stiffness reduction rate exceeding 50% was judged as "B".

[0135] [Penetration Resistance: MBH] Penetration resistance was evaluated in accordance with JIS R3212. Penetration resistance was determined according to the following criteria. Specifically, a steel ball with a mass of 2260 ± 20 g and a diameter of approximately 82 mm was selected. The steel ball was placed at an arbitrary height from the surface of laminated glass set on a horizontal plane, and the steel ball was dropped towards the center of the laminated glass without applying any force from a stationary position. The laminated glass was made using two sheets of glass with a thickness of 2.75 mm (2.75 mm is the measured value, the nominal value is 3 mm). The steel ball was dropped towards the center of the laminated glass from an arbitrary height, i.e., the distance from the surface of the laminated glass to the steel ball was set to X m. The test was performed on six sheets of laminated glass, and if penetration occurred, the distance was reduced by -0.5 m, and if it did not penetrate, the distance was increased by +0.5 m, and the test was repeated. As a result of the six tests, an approximate straight line was drawn using Excel with the probability of penetration of the laminated glass on the horizontal axis and the height of the dropped ball on the vertical axis. The point on the approximate straight line where the probability of penetration is 50% was defined as MBH. If the MBH was 4m or more, it was classified as "A," and if the MBH was less than 4m, it was classified as "B."

[0136] [Overall Assessment] For bending stiffness, stiffness reduction rate, and MBH (penetration resistance), all assessment results were "A" for the overall assessment, and for at least one assessment result was "B" for the overall assessment.

[0137] The components used in the examples and comparative examples of this embodiment were as follows:

[0138] ・Ionomer 1C: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions. In the ionomer resin, constituent units derived from methacrylic acid (A) = 5.5% by mass, constituent units derived from neutralized methacrylic acid (B) = 14.2% by mass, and constituent units derived from ethylene (C) = 80.3% by mass, degree of neutralization = 72% ・Ionomer 2C: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with magnesium ions. In the ionomer resin, constituent units derived from methacrylic acid (A) = 5.1% by mass, constituent units derived from neutralized methacrylic acid (B) = 12.8% by mass, and constituent units derived from ethylene (C) = 82.1% by mass, degree of neutralization = 72% ・Ionomer 3C: Ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with sodium ions. In the ionomer resin, the constituent units (A) derived from methacrylic acid = 9.7% by mass, the constituent units (B) derived from neutralized methacrylic acid = 10.5% by mass, and the constituent units (C) derived from ethylene = 79.8% by mass, with a degree of neutralization of 52%. Ionomer 4C: An ionomer resin obtained by neutralizing an ethylene-methacrylic acid copolymer with zinc ions. In the ionomer resin, the constituent units (A) derived from methacrylic acid = 10.9% by mass, the constituent units (B) derived from neutralized methacrylic acid = 9.3% by mass, and the constituent units (C) derived from ethylene = 79.8% by mass, with a degree of neutralization of 46%. • Copolymer 1C: Ethylene-methacrylic acid copolymer, constituent units (A) derived from methacrylic acid = 19.7% by mass, and constituent units (C) derived from ethylene = 80.3% by mass, MFR = 500 g / 10 min • Copolymer 2C: Ethylene-methacrylic acid copolymer, constituent units (A) derived from methacrylic acid = 19.7% by mass, and constituent units (C) derived from ethylene = 80.3% by mass, MFR = 60 g / 10 min - Polyvinyl butyral resin (PVB1C): Average degree of polymerization 3300, hydroxyl group content 30.8 mol%, degree of acetylation 0.8 mol%, degree of acetalization 68.4 mol% - Silane coupling agent (SiCp): "KBM-602", manufactured by Shin-Etsu Chemical Co., Ltd., N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane

[0139] [Examples 1C to 10C, Comparative Examples 1C to 12C] Each component listed in Tables 4 and 5 was put into an extruder, kneaded at 170°C, and extruded to obtain an interlayer film with a thickness of 0.76 mm and a width of 2.0 m. The composition of the resin and additives constituting the obtained interlayer film is shown in Tables 4 and 5. Using this interlayer film, laminated glass for various evaluations was prepared as follows, and various evaluations were performed. For Comparative Examples 9C to 12C, the amount of Mg salt (magnesium butyrate) added was adjusted within a known range to obtain interlayer films with different Pammel values.

[0140] (Preparation of laminated glass for Pammel value measurement) Two pieces of float glass (manufactured by Sanshiba Glass Materials Co., Ltd.) measuring 30 cm in length, 15 cm in width, and 2.75 mm in thickness (2.75 mm is the measured value, the nominal value is 3 mm) were prepared, along with one interlayer film measuring 30 cm in length, 15 cm in width, and 0.76 mm in thickness. The interlayer film was sandwiched between the two pieces of float glass to obtain a laminated intermediate. This laminated intermediate was placed in a rubber bag and degassed at a vacuum of 0.08 MPa for 20 minutes. Then, while still degassed, it was transferred to an oven and held at 90°C for 30 minutes to vacuum press and temporarily bond the laminated intermediate. The temporarily bonded laminated intermediate was pressed in an autoclave at 140°C and a pressure of 1.3 MPa for 20 minutes to obtain laminated glass with the two pieces of glass bonded together by the interlayer film (thickness 0.76 mm). The Pammel value was measured using the obtained laminated glass. Furthermore, the top surface of each float glass plate (the surface opposite the tin surface) was adjusted to become the bonding surface with the interlayer.

[0141] (Preparation of Laminated Glass for Bending Stiffness Measurement) Two pieces of float glass (manufactured by Sanshiba Glass Materials Co., Ltd.) measuring 20 cm in length, 8 cm in width, and 2.75 mm in thickness (2.75 mm is the measured value, the nominal value is 3 mm) were prepared, along with one interlayer measuring 20 cm in length, 8 cm in width, and 0.76 mm in thickness. The interlayer was sandwiched between the two pieces of float glass to obtain a laminated intermediate. This laminated intermediate was placed in a rubber bag and degassed at a vacuum of 0.08 MPa for 20 minutes. Then, while still degassed, it was transferred to an oven and held at 90°C for 30 minutes to vacuum press and temporarily bond the laminated intermediate. The temporarily bonded laminated intermediate was pressed in an autoclave at 140°C and a pressure of 1.3 MPa for 20 minutes to obtain laminated glass with the two pieces of glass bonded together by the interlayer (thickness 0.76 mm). The bending stiffness was measured using the obtained laminated glass. Furthermore, the top surface of each float glass plate (the surface opposite the tin surface) was adjusted to become the bonding surface with the interlayer.

[0142] (Preparation of laminated glass for MBH measurement) Two pieces of float glass (manufactured by Sanshiba Glass Materials Co., Ltd.) measuring 30 cm x 30 cm x 2.75 mm thick (2.75 mm is the measured value, the nominal value is 3 mm) were prepared, along with one interlayer measuring 30 cm x 30 cm x 0.76 mm thick. The interlayer was sandwiched between the two pieces of float glass to obtain a laminated intermediate. This laminated intermediate was placed in a rubber bag and degassed at a vacuum of 0.08 MPa for 20 minutes. Then, while still degassed, it was transferred to an oven and held at 90°C for 30 minutes to vacuum press and temporarily bond the laminated intermediate. The temporarily bonded laminated intermediate was pressed in an autoclave at 140°C and a pressure of 1.3 MPa for 20 minutes to obtain laminated glass with the two pieces of glass bonded together by the interlayer (thickness 0.76 mm). MBH was measured using the obtained laminated glass. Furthermore, the top surface of each float glass plate (the surface opposite the tin surface) was adjusted to become the bonding surface with the interlayer.

[0143]

[0144]

[0145] The interlayers of each example had a glass transition temperature of 58°C or higher and a Pummel value of less than 9.0, resulting in high bending stiffness and a low rate of bending stiffness reduction, ensuring high static stiffness over a wide temperature range. Furthermore, they also had high MBH values ​​and good resistance to high-speed impacts. In contrast, the interlayers of Comparative Examples 3C-6C and 9C had a Pummel value of 9.0, resulting in low MBH values ​​and poor resistance to high-speed impacts. Comparative Examples 1C-2C, 7C-8C, and 10C-12C had a Pummel value of less than 9.0, and although their MBH values ​​were high, their glass transition temperatures were below 58°C, resulting in low bending stiffness values ​​and the inability to ensure high static stiffness over a wide temperature range.

[0146] Although this disclosure describes only a limited number of embodiments, those skilled in the art who have access to this disclosure will understand that various other embodiments can be derived without departing from the scope of the invention. Accordingly, the scope of the invention is limited only by the appended claims.

Claims

1. An interlayer having a glass transition temperature of 50°C or higher, and exhibiting a puncture stroke of 18.6 mm or more in a puncture impact test performed on laminated glass obtained by bonding two 2.75 mm thick float glass plates together via an interlayer.

2. An interlayer having a glass transition temperature of 50°C to 65°C, and a complex viscosity of 800 Pa·s or more, measured at a measurement temperature of 200°C and a frequency of 1 Hz.

3. An interlayer having a glass transition temperature of 58°C or higher and a Pammel value of less than 9.

0.

4. The interlayer according to claim 1, wherein the glass transition temperature is 50°C or higher and 77°C or lower.

5. The interlayer according to claim 3, wherein the glass transition temperature is 58°C or higher and 75°C or lower.

6. The interlayer according to any one of claims 1 to 5, wherein the bending rigidity at 50°C of the laminated glass obtained by bonding two float glass plates with a thickness of 2.75 mm via an interlayer is 700 N / mm or more.

7. An interlayer according to any one of claims 1 to 5, comprising an ionomer resin.

8. The interlayer film according to claim 7, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the total content of constituent units (A) derived from (meth)acrylic acid and constituent units (B) derived from (meth)acrylic acid neutralized product is 10% by mass or more and 25% by mass or less based on the total amount of the ethylene-(meth)acrylic acid copolymer and its ionomer resin.

9. The interlayer film according to claim 7, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units (B) derived from (meth)acrylic acid neutralized product is 4% by mass or more and 17.5% by mass or less, based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin.

10. The interlayer film according to claim 7, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units (A) derived from (meth)acrylic acid is 0% by mass or more and 11.5% by mass or less, based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin.

11. The interlayer film according to claim 7, wherein the ionomer resin is an ionomer resin of an ethylene-(meth)acrylic acid copolymer, and the content of constituent units derived from alkyl (meth)acrylate is 0% by mass or more and 4.5% by mass or less, based on the total amount of the ethylene-(meth)acrylic acid copolymer and the ionomer resin.

12. The interlayer according to claim 7, wherein the ionomer resin comprises a constituent unit (A) derived from (meth)acrylic acid, a constituent unit (B) derived from (meth)acrylic acid neutralized product, and a constituent unit (C) derived from ethylene.

13. The interlayer film according to claim 12, wherein the constituent unit (B) comprises at least one of magnesium and zinc.

14. The interlayer according to claim 7, further comprising a silane coupling agent, wherein the content of the silane coupling agent is 0.1% by mass or less based on the total mass of the interlayer.

15. The interlayer according to claim 7, further comprising a silane coupling agent, wherein the content of the silane coupling agent is 1% by mass or less based on the total mass of the interlayer.

16. The interlayer according to claim 7, further comprising a silane coupling agent, wherein the content of the silane coupling agent is 0.15% by mass or less based on the total mass of the interlayer.

17. A laminate comprising an interlayer film according to any one of claims 1 to 5 and two substrates, wherein the interlayer film is disposed between the two substrates.

18. The laminate according to claim 17, wherein the substrate is glass.

19. A structural glazing for buildings, having the laminate described in claim 17.

20. A laminate comprising an interlayer and two substrates, wherein the interlayer is disposed between the two substrates, the glass transition temperature of the interlayer is 50°C or higher, and the puncture stroke in a puncture impact test performed on the laminate is 18.6 mm or higher.

21. A laminate comprising an interlayer film and two substrates, wherein the interlayer film is disposed between the two substrates, the glass transition temperature of the interlayer film is 50°C or higher and 65°C or lower, and the complex viscosity of the interlayer film, measured at a measurement temperature of 200°C and a frequency of 1 Hz, is 800 Pa·s or higher.

22. A laminate comprising an interlayer film and two substrates, wherein the interlayer film is disposed between the two substrates, and the glass transition temperature of the interlayer film is 58°C or higher, and the Pummel value is less than 9.

0.

23. The laminate according to any one of claims 20 to 22, wherein the interlayer comprises an ionomer resin.

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