Laminated glass structure

Abstract

To provide a laminated glass structure having superior anti-crime performance.SOLUTION: A laminated glass structure including first and second glasses and an interlayer film (A) having one or more resin layers between the first and second glasses, wherein the laminated glass structure has at least one of a light-control film and a colored layer, at least one of the first and second glasses has a Mohs hardness of 5.5 or more, the interlayer film (A) includes a polyvinyl acetal resin, and a storage modulus of the interlayer film (A) at 90°C is 1.0×105 Pa or more and 2.9×105 Pa or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a laminated glass structure comprising first and second glass sheets and an interlayer film disposed therebetween. [Background technology]

[0002] Conventionally, laminated glass structures have been widely known, in which two glass sheets are integrated with an interlayer film interposed between them. The interlayer film is often made of plasticized polyvinyl acetal, which is a polyvinyl acetal resin blended with a plasticizer. Laminated glass structures are safe because even if they are broken by external impact, few glass fragments are scattered, and therefore they are widely used as window glass in vehicles such as automobiles, aircraft, buildings, etc. (See, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-063006 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been an increase in car break-ins, in which car thefts are committed by breaking the window glass of automobiles, and there is a demand for anti-theft measures for laminated glass structures used in automobile windows. Known methods of car theft include smashing the window glass with a hammer or the "burning" method. Even if the glass of a laminated glass structure is smashed, it is not easily penetrated because the glass adheres to the interlayer film surface, so it can be said that the laminated glass structure has a certain degree of anti-theft performance against smashing with a hammer or the like.

[0005] On the other hand, "fire-breaking" is a method that utilizes the phenomenon in which heat is applied to the glass surface with a burner or the like to cause thermal expansion, and then rapid cooling causes the heated area to contract rapidly, breaking the glass. Fire-breaking is popular among thieves because it is quieter than smashing with a hammer or the like and can be done in a short amount of time. Furthermore, because laminated glass structures have high security against smashing as mentioned above, it is necessary to take measures against fire-breaking.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a laminated glass structure having excellent crime prevention properties. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that, in recent years, laminated glass structures have been developed that incorporate colored layers or light-control films to enhance design. However, because such laminated glass structures are often used in luxury vehicles, they are often targeted by thieves. Furthermore, they have found that, although the glass itself breaks during firebreaking, the interlayer film is flexible and cannot be penetrated, requiring a separate glass cutter or similar tool to cut it. In this case, if the hardness of the glass and the interlayer film differs, two different cutters are required, which increases the time required for penetration. Furthermore, they have found that, during firebreaking, the glass surface is heated to several hundred degrees Celsius using a burner or similar tool, but the interlayer film is only heated to around 100 degrees Celsius due to the low thermal conductivity of the glass, and that resistance to firebreaking depends on the flexibility of the interlayer film at 90 degrees Celsius. Based on this finding, they have completed the present invention, which is described below. Specifically, the present invention provides the following [1] to [5].

[0008] [1] A laminated glass structure comprising first and second glass panes and an interlayer film (A) having at least one resin layer between the first and second glass panes, wherein the laminated glass structure has at least one of a light control film and a colored layer; At least one of the first and second glasses has a Mohs hardness of 5.5 or more, the interlayer film (A) contains a polyvinyl acetal resin, and the storage modulus of the interlayer film (A) at 90°C is 1.0 × 105 Pa or more 2.9×10 5 The laminated glass structure has a resistance of 0.05 Pa or less. [2] The laminated glass structure according to the above [1], wherein the polyvinyl acetal resin has a glass transition temperature of −10° C. or higher and 50° C. or lower. [3] The laminated glass structure according to [1] or [2] above, wherein the softening point of the polyvinyl acetal resin is 50°C or higher and 120°C or lower. [4] The laminated glass structure according to any one of the above [1] to [3], wherein the light control film has a PET film. [5] The laminated glass structure according to any one of the above [1] to [4], wherein the first and second glasses are not heat-absorbing glasses. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a laminated glass structure having excellent crime prevention properties. [Brief explanation of the drawings]

[0010] [Figure 1] 1 shows a laminated glass structure according to a first embodiment of the present invention. [Figure 2] 3 shows a laminated glass structure according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The laminated glass structure of the present invention is a laminated glass structure comprising first and second glass sheets and an interlayer film (A) disposed between the first and second glass sheets. The laminated glass structure of the present invention has at least one of a light control film and a colored layer. Laminated glass structures having at least one of a light control film and a colored layer are often used in luxury cars with enhanced design, making them easy targets for thieves. However, in the present invention, as will be described later, the storage modulus and Mohs hardness at 90°C can be set within a predetermined range to improve security. When the laminated glass structure of the present invention has a colored layer, the interlayer film (A) may contain the colored layer, or a film other than the interlayer film (A) may have the colored layer, as described below.

[0012] <Interlayer film (A)> The interlayer film (A) of the present invention has at least one resin layer and contains a polyvinyl acetal resin. The structure of the interlayer film (A) will be described in detail below.

[0013] [Storage modulus at 90℃] The interlayer film (A) of the present invention has a storage modulus at 90°C of 1.0 x 10 5 Pa or more 2.9×10 5 In the present invention, by increasing the Mohs hardness as described below and setting the storage modulus to a certain value or less as described above, it becomes difficult to cut the laminated glass structure with a single type of glass cutter after fire-breaking, and the anti-theft properties are excellent. On the other hand, the interlayer (A) is 2.9 × 10 5 If the pressure is higher than 1.0×10 Pa, the interlayer film (A) will also be easily cut by the glass cutter used to cut the first and second glass panes after burning and breaking, making it difficult to sufficiently improve the security. 5 If the resistance is less than Pa, the interlayer (A) becomes too soft at around 100°C, making it easier to penetrate after burning, and reducing the security. The storage modulus at 90°C is set to 1.1 x 10 5 Pa or more is preferable, 1.2 × 10 5 Pa or more is more preferable, 1.3 × 10 5 Pa or more is more preferable, and 1.4 × 10 5 Pa or more is particularly preferable, and 2.7 × 10 5 Pa or less is preferable, and 2.4 × 10 5 Pa or less is more preferable, and 2.0×10 5 Pa or less is more preferable. The storage modulus is a shear storage modulus, and can be measured under the measurement conditions described in the examples below.

[0014] [Thickness change amount] The interlayer film (A) preferably has a thickness change of 80 μm or more when compressed in a compression creep test carried out under the following conditions. (Compression creep test) First, a test sample with a diameter of 8 mm and a thickness of 800 μm is prepared from the interlayer film (A). Next, the test sample is compressed for 5 minutes under conditions of a load of 410 g and 30°C, and the thickness (T1) of the test sample is measured. Then, while maintaining the load of 410 g, the temperature is increased from 30°C to 90°C at a heating rate of 6°C / min. Then, after 5 minutes of compression under conditions of a load of 410 g and 90°C, the thickness (T2) of the test sample is measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the test sample is defined as the thickness change.

[0015] If the thickness of the interlayer film (A) is less than 800 μm, the test sample may be prepared by stacking two or more interlayer films (A), pressing them together by suitable means such as hot pressing, adjusting the thickness to 800 μm by pressing, and then cutting it into a cylindrical shape with a diameter of 8 mm. Furthermore, when the thickness of the interlayer film (A) is 800 μm or more, the test sample may be prepared by adjusting the thickness to 800 μm by hot pressing or the like, if necessary, and then cutting it into a cylindrical shape with a diameter of 8 mm. If the surface of the test sample has irregularities such as embossing, the test sample may be adjusted to make the surface flat by, for example, hot pressing the test sample, and then cut into a cylindrical shape with a diameter of 8 mm to produce the test sample.

[0016] When the thickness change of the interlayer film (A) is 80 μm or more, even when the first and second glasses are integrated by autoclaving at low pressure and low temperature or by other means, residual air or bubbles are unlikely to form between the glasses or the light control film (described later) and the interlayer film (A), which would cause poor appearance. The thickness change of the interlayer film (A) is preferably 90 μm or more, more preferably 120 μm or more, and even more preferably 140 μm or more. The thickness change of the interlayer film (A) is, for example, 400 μm or less, preferably 320 μm or less, more preferably 220 μm or less, and even more preferably 180 μm or less. Keeping the thickness change at a certain value or less prevents the interlayer film (A) from becoming too soft, and prevents, for example, gas dissolved in the interlayer film (A) from being released to the outside and forming bubbles, thereby preventing poor appearance.

[0017] The thickness change and storage modulus at 90°C can be adjusted appropriately by the polyvinyl acetal resin used in the interlayer film (A). For example, they can be adjusted by the molecular weight and molecular weight distribution (Mw / Mn) of the polyvinyl acetal resin. Specifically, a smaller molecular weight or a larger molecular weight distribution (Mw / Mn) with an increased content of low molecular weight components reduces the storage modulus at 90°C and increases the thickness change. The storage modulus and thickness change at 90°C can also be adjusted by the production conditions when producing the polyvinyl acetal resin. Specifically, as will be described later, the storage modulus and thickness change at 90°C can be adjusted by the aging conditions in the aging step performed when producing the polyvinyl acetal resin. It can also be adjusted by the amount and type of plasticizer contained in the interlayer film (A). For example, increasing the amount of plasticizer tends to decrease the storage modulus at 90°C. On the other hand, the thickness change tends to increase. Furthermore, when an ether-based plasticizer such as a polyoxyalkylene ether-based plasticizer or a polyoxyalkylene ether-based plasticizer is used as the plasticizer, the storage modulus at 90°C is less likely to decrease, while the thickness change tends to increase.

[0018] [Weight average molecular weight] The interlayer film (A) preferably has a weight average molecular weight (Mw) of 200,000 or more and 310,000 or less. When the Mw of the interlayer film (A) is equal to or more than the above lower limit, the storage modulus at 90°C tends to be high, and the strength of the interlayer film (A) tends to be improved. On the other hand, when the Mw of the interlayer film (A) is equal to or less than the above upper limit, the flexibility of the interlayer film (A) tends to be ensured, and the storage modulus at 90°C tends to be equal to or less than the above-mentioned specified upper limit. The weight average molecular weight (Mw) of the interlayer film (A) is more preferably 220,000 or more and 300,000 or less, and preferably 230,000 or more and 270,000 or less.

[0019] [Molecular weight distribution] The interlayer film (A) preferably has a molecular weight distribution, expressed as the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), of 3.0 or less. A molecular weight distribution (Mw / Mn) of 3.0 or less can suppress the amount of low molecular weight components contained in the interlayer film (A), thereby preventing the storage modulus from becoming too low. The molecular weight distribution (Mw / Mn) of the interlayer film (A) is more preferably 2.5 or less, even more preferably 2.4 or less, and even more preferably 2.0 or less. The lower the molecular weight distribution (Mw / Mn) of the interlayer film (A), the better; a value of 1.0 or more is sufficient, but in practice it may be 1.1 or more, or 1.3 or more. The weight average molecular weight (Mw) and number average molecular weight (Mn) of the interlayer film (A) are measured by gel permeation chromatography. The weight average molecular weight and molecular weight distribution of the interlayer film (A) are values ​​obtained by measuring the molecular weight of the interlayer film (A). Therefore, the interlayer film (A) may contain components other than the polyvinyl acetal resin described below, such as plasticizers, and in such cases, the Mw and Mn values ​​will take into account the components other than the polyvinyl acetal resin.

[0020] (Polyvinyl acetal resin) The interlayer film (A) of the present invention contains a polyvinyl acetal resin. By containing the polyvinyl acetal resin, the storage modulus of the interlayer film (A) can be easily adjusted to a predetermined range. This makes the interlayer film (A) less likely to be cut with a glass cutter used to cut glass, which tends to improve security. Furthermore, the interlayer film (A) can be easily improved in moist heat resistance and impact resistance, and can also be easily improved in adhesion to inorganic glass and the like.

[0021] The polyvinyl acetal resin is a thermoplastic resin. There are no particular limitations on the polyvinyl acetal resin, as long as it is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The aldehyde is not particularly limited, but generally, an aldehyde having 1 to 10 carbon atoms is suitably used. The aldehyde having 1 to 10 carbon atoms is not particularly limited, and examples thereof include n-butylaldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, formaldehyde, acetaldehyde, benzaldehyde, etc. These aldehydes may be used alone or in combination of two or more. Among the above, n-butylaldehyde, n-hexylaldehyde, and n-valeraldehyde are preferred, and n-butylaldehyde is more preferred. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin.

[0022] Polyvinyl alcohol (PVA) can be obtained by saponifying a polyvinyl ester such as polyvinyl acetate, etc. The degree of saponification of polyvinyl alcohol is generally 70 to 99.9 mol %. The average degree of polymerization of the PVA is preferably 200 or more, more preferably 500 or more, even more preferably 1000 or more, and even more preferably 1500 or more. When the average degree of polymerization is equal to or greater than the above-mentioned lower limit, the penetration resistance of the laminated glass structure is improved when the PVA is used in the laminated glass structure. The average degree of polymerization of the PVA is preferably 5000 or less, more preferably 4000 or less, even more preferably 3500 or less, and even more preferably 2500 or less. The average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Testing method for polyvinyl alcohol."

[0023] Two or more polyvinyl alcohols having different average degrees of polymerization may be used as the polyvinyl alcohol raw material for the polyvinyl acetal resin. In this case, it is preferable to use a mixture of two or more polyvinyl alcohols as the raw material to produce the polyvinyl acetal resin by the production method described below. When two or more types of polyvinyl alcohols are used, it is preferable to use, for example, a first polyvinyl alcohol having an average degree of polymerization of 1500 or more and a second polyvinyl alcohol having an average degree of polymerization of 1000 or less. By using two or more types of polyvinyl alcohols having different average degrees of polymerization, it becomes easier to reduce the storage modulus at 90°C. It also becomes easier to increase the amount of thickness change. The average degree of polymerization of the first polyvinyl alcohol is preferably 1500 or more and 3500 or less, more preferably 1600 or more and 2500 or less, and even more preferably 1600 or more and 2000 or less. The average degree of polymerization of the second polyvinyl alcohol is preferably 200 or more and 1000 or less, more preferably 300 or more and 900 or less, and even more preferably 400 or more and 700 or less. When the first and second polyvinyl alcohols are used, the blending ratio of the first polyvinyl alcohol to the second polyvinyl alcohol is not particularly limited, but the blending amount of the second polyvinyl alcohol relative to the total amount of the first and second polyvinyl alcohols is, for example, 1% by mass or more and 70% by mass or less, preferably 3% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less. Two or more polyvinyl alcohols having different average degrees of polymerization may be used as the polyvinyl alcohol raw material for the polyvinyl acetal resin. In this case, it is preferable to use a mixture of two or more polyvinyl alcohols as the raw material to produce the polyvinyl acetal resin by the production method described below.

[0024] The amount of hydroxyl groups in the polyvinyl acetal resin is preferably 15 mol% or more, and preferably 38 mol% or less. By setting the amount of hydroxyl groups to 15 mol% or more, good adhesion is likely to be achieved, and the penetration resistance of the laminated glass structure is likely to be good. Furthermore, it is easy to achieve a storage modulus at 90°C of a certain value or more. Furthermore, by setting the amount of hydroxyl groups to 38 mol% or less, flexibility is easily ensured, the laminated glass structure is prevented from becoming too hard, and the storage modulus at 90°C is also easily reduced. Furthermore, adjusting the amount of hydroxyl groups within the above range makes it easy to adjust the amount of thickness change within a desired range. The amount of hydroxyl groups is more preferably 20 mol % or more, and even more preferably 25 mol % or more, and more preferably 35 mol % or less, and even more preferably 33 mol % or less. When a polyvinyl butyral resin is used as the polyvinyl acetal resin, from the same viewpoint, the amount of hydroxyl groups is 15 mol% or more, and preferably 38 mol% or less, more preferably 20 mol% or more, even more preferably 25 mol% or more, more preferably 35 mol% or less, and even more preferably 33 mol% or less. The amount of hydroxyl groups in the polyvinyl acetal resin is the molar fraction calculated by dividing the amount of ethylene groups having hydroxyl groups by the total amount of ethylene groups in the main chain, and is expressed as a percentage. The amount of ethylene groups having hydroxyl groups can be measured by the procedure described in the Examples.

[0025] The degree of acetalization of the polyvinyl acetal resin is preferably 47 mol% or more and preferably 85 mol% or less, more preferably 55 mol% or more, even more preferably 60 mol% or more, and more preferably 80 mol% or less, even more preferably 75 mol% or less. The degree of acetalization means the degree of butyralization when the acetal group is a butyral group and the polyvinyl acetal resin (A) is a polyvinyl butyral resin.

[0026] The degree of acetalization is a molar fraction calculated by subtracting the amount of ethylene groups having hydroxyl groups and the amount of ethylene groups having acetyl groups from the total amount of ethylene groups in the main chain, and dividing the result by the total amount of ethylene groups in the main chain. The degree of acetalization (degree of butyralization) can be calculated based on the amount of ethylene groups having hydroxyl groups and the amount of ethylene groups having acetyl groups, which are calculated by the procedures described in the Examples.

[0027] The acetylation degree of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, and even more preferably 2 mol% or less. When the acetylation degree is equal to or less than the upper limit, the moisture resistance of the polymer film is improved. Furthermore, the acetylation degree is not particularly limited, but is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more. The degree of acetylation is a molar fraction calculated by dividing the amount of ethylene groups having acetyl groups bonded thereto by the total amount of ethylene groups in the main chain, and is expressed as a percentage. The amount of ethylene groups having acetyl groups bonded thereto can be measured by the procedure described in the Examples.

[0028] The polyvinyl acetal resin is preferably an unmodified polyvinyl acetal resin, but may also be a modified polyvinyl acetal resin. The modified polyvinyl acetal resin has a structure (modifying group) other than an acetal group, a hydroxyl group, and an acetyl group, and preferably has a modifying group in a side chain. Examples of the modifying group include those having a polyalkylene oxide structure in the side chain, and those having an alkyl group (e.g., having about 2 to 30 carbon atoms) other than an acetal group or an acetyl group in the side chain. The modification amount is not particularly limited, but is, for example, about 0.1 mol % to 10 mol %. The modification amount represents the ratio of functional groups to all vinyl monomer units constituting the polyvinyl acetal resin. In the interlayer film (A), the polyvinyl acetal resin may be used alone or in combination of two or more kinds.

[0029] (glass transition temperature) The glass transition temperature (Tg) of the polyvinyl acetal resin is preferably -10°C or higher. Having a glass transition temperature equal to or higher than the above lower limit prevents the interlayer film from becoming too soft at around 100°C. As a result, after being burned through, the interlayer film is less likely to be penetrated easily, which tends to improve security. The glass transition temperature (Tg) of the polyvinyl acetal resin is more preferably -5°C or higher, even more preferably 0°C or higher, and particularly preferably 5°C or higher. The glass transition temperature (Tg) of the polyvinyl acetal resin is preferably 50° C. or lower, more preferably 40° C. or lower, even more preferably 30° C. or lower, still more preferably 25° C. or lower, and particularly preferably 20° C. or lower. When the glass transition temperature of the polyvinyl acetal resin is the above upper limit or lower, the adhesiveness to glass and the like tends to be good. The glass transition temperature of the polyvinyl acetal resin can be determined by measuring the viscoelasticity using a dynamic viscoelasticity measuring device and reading the peak temperature of the loss tangent tanδ obtained from the viscoelasticity measurement results. The detailed measurement conditions are as described in the Examples.

[0030] (softening point) The softening point of the polyvinyl acetal resin is preferably 50°C or higher. Having a softening point equal to or higher than the above lower limit prevents the interlayer film from becoming too soft at around 100°C. As a result, after being burned through, the interlayer film is less likely to be penetrated easily, and the anti-theft performance is likely to be improved. The softening point of the polyvinyl acetal resin is more preferably 60°C or higher, and even more preferably 70°C or higher. The softening point of the polyvinyl acetal resin is preferably 120°C or lower, more preferably 110°C or lower, even more preferably 100°C or lower, and even more preferably 90°C or lower. When the softening point of the polyvinyl acetal resin is equal to or lower than the above upper limit, the interlayer film can be easily bonded to the first and second glass sheets by thermocompression bonding or the like. The softening point of the polyvinyl acetal resin refers to the Vicat softening temperature, and can be measured by the method described in the examples below.

[0031] The interlayer film (A) may contain a thermoplastic resin other than polyvinyl acetal resin, as long as the effects of the present invention are achieved. Examples of thermoplastic resins other than polyvinyl acetal resin include (meth)acrylic resins, polyvinyl acetal resins, polyvinyl alcohol resins (PVA), polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymers (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and styrene-butadiene copolymer resins. These thermoplastic resins may be used alone or in combination of two or more. However, it is preferable that the interlayer film (A) contains a polyvinyl acetal resin as the main component. Specifically, the content of the polyvinyl acetal resin is, for example, 40 mass% or more, preferably 50 mass% or more, more preferably 60 mass% or more, and most preferably 65 mass% based on the total mass of the interlayer film (A). Therefore, the thermoplastic resin contained in the interlayer film (A) of the present invention may consist solely of a polyvinyl acetal resin.

[0032] (Method for producing polyvinyl acetal resin) The polyvinyl acetal resin is preferably produced by a production method including a mixing step of mixing the polyvinyl alcohol and the aldehyde, and an aging step of aging the mixture obtained in the mixing step.

[0033] In the mixing step, polyvinyl alcohol and aldehyde may be mixed according to a conventional method. In addition to polyvinyl alcohol and aldehyde, a catalyst such as an acid catalyst may be added to promote the acetalization reaction. For example, the aldehyde may be added to a mixture of polyvinyl alcohol and an acid catalyst at a low temperature of about 0 to 20°C. A solvent such as water is also typically added. When two or more types of polyvinyl alcohols are used in combination (for example, when two or more types of polyvinyl alcohols with different molecular weights are used), it is advisable to mix the two or more types of polyvinyl alcohols with an aldehyde.

[0034] The aging step is not particularly limited, but may be carried out, for example, by adding a catalyst such as an acid catalyst to the mixture (reaction mixture) obtained by the mixing step, heating the mixture to a aging temperature, and maintaining the mixture at the aging temperature for a certain period of time. In this production method, acetalization of polyvinyl alcohol proceeds in the mixing step and the aging step, thereby producing a polyvinyl acetal resin. The reaction mixture is maintained at the aging temperature for a certain period of time, and then cooled appropriately and neutralized, and may then be washed with water, dried, or the like, as necessary.

[0035] Examples of the acid catalyst added in the mixing step and the aging step include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, etc. In the aging step, the concentration of the acid catalyst may be adjusted to, for example, about 0.5% by mass or more and 5% by mass or less, and preferably about 1% by mass or more and 2.5% by mass or less. The aging temperature in the aging step may be relatively low, for example, 30° C. to 65° C., preferably 35° C. to 60° C., and more preferably 40° C. to 57° C. The time for which the aging temperature is maintained (aging time) may be longer than a certain time, for example, 75 minutes to 180 minutes, preferably 90 minutes to 150 minutes, and more preferably 100 minutes to 140° C. It is believed that setting the aging temperature and aging time within the desired ranges above facilitates uniform distribution of hydroxyl groups within the molecules of the polyvinyl acetal resin, thereby facilitating adjustment of the storage modulus at 90°C within the desired range. It also enables a large thickness change. Furthermore, the amount of low molecular weight components decreases, which tends to lower the molecular weight distribution (Mw / Mn). While the reason for the decrease in low molecular weight components is unclear, it is believed to be due to the promotion of intermolecular crosslinking.

[0036] (plasticizer) The interlayer film (A) preferably contains a plasticizer. The inclusion of a plasticizer makes the interlayer film (A) flexible, which can improve the adhesion of the interlayer film (A) to various adherends and the penetration resistance. In addition, the storage modulus at 90°C can be reduced and the thickness change can be increased.

[0037] Examples of the plasticizer include organic ester plasticizers, organic phosphorus-based plasticizers such as organic phosphate ester plasticizers and organic phosphite ester plasticizers, organic ether-based plasticizers such as polyalkylene glycol-based plasticizers and polyoxyalkylene ether-based plasticizers, and alcohol-based plasticizers. The plasticizers may be used alone or in combination of two or more. Among the above, organic ester plasticizers and organic ether plasticizers are preferred.

[0038] Preferred organic ester plasticizers include monobasic organic acid esters and polybasic organic acid esters. Examples of monobasic organic acid esters include esters of glycols and monobasic organic acids. Examples of glycols include polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the number of repeating alkylene units is 2 to 10, preferably 2 to 4. The glycol may also be a monoalkylene glycol having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms (i.e., one repeating unit). Specific examples of glycols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and butylene glycol. Examples of monobasic organic acids include organic acids having 3 to 10 carbon atoms, and specific examples thereof include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, n-nonylic acid, and decylic acid.

[0039] Specific monobasic organic acids include triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, and triethylene glycol. Di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, ethylene glycol di-2-ethylbutyrate, 1,2-propylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, 1,2-butylene glycol di-2-ethylbutyrate, and the like.

[0040] Furthermore, examples of polybasic organic acid esters include ester compounds of dibasic organic acids having 4 to 12 carbon atoms, such as adipic acid, sebacic acid, and azelaic acid, with alcohols having 4 to 10 carbon atoms. The alcohols having 4 to 10 carbon atoms may be linear, have a branched structure, or have a cyclic structure. Specific examples include dibutyl sebacate, dioctyl azelaate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl carbitol adipate, and mixed adipates. Oil-modified alkyd sebacate is also acceptable. Examples of mixed adipates include adipates prepared from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms.

[0041] The organic ester plasticizer is not limited to the complete esters of the above-mentioned esters, but may also be a partial ester. For example, it may be a partial ester of glycol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol. Specific examples include triethylene glycol-mono-2-ethylhexanoate. Furthermore, it may be a partial ester of a monobasic organic acid with a trihydric or higher alcohol such as glycerin. Examples of the monobasic organic acid include monobasic organic acids having 3 to 24 carbon atoms, preferably 6 to 18 carbon atoms. Specific examples of the partial ester of a trihydric or higher alcohol with a monobasic organic acid include a mono- or diester of glycerin and stearic acid, and a mono- or diester of glycerin and 2-ethylhexyl acid. Of the organic ester plasticizers mentioned above, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferably used.

[0042] Examples of the organic phosphorus plasticizer include phosphoric acid esters such as tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

[0043] Examples of polyalkylene glycol plasticizers include polyoxyalkylene compounds having a polyoxyalkylene structure, specifically polyhydric alcohol compounds such as glycol, ester compounds of glycol with a monobasic organic acid or a polybasic organic acid, and ether compounds of a monohydric or polyhydric alcohol with a polyoxyalkylene. Examples of glycols include polyoxyalkylene glycols and their derivatives. Examples of polyoxyalkylenes include polyoxyethylene, polyoxypropylene, polyoxybutylene, and random or block copolymers thereof. The polyoxyalkylene compounds may be polyhydric alcohol compounds, ester compounds, ether compounds, or other compounds, as described above.

[0044] Examples of polyoxyalkylene compounds include polyoxyalkylenes and derivatives thereof. More specifically, examples include polyoxyalkylene glycols composed of the above-mentioned polyoxyalkylenes, and ether compounds of polyoxyalkylenes and polyhydric alcohols. All of these compounds may have hydroxyl groups at their terminals, or may be derivatives in which some or all of the hydrogen atoms of the terminal hydroxyl groups have been substituted with alkyl groups or acyl groups. The number of carbon atoms in the alkyl and acyl groups is not particularly limited, but may be about 1 to 8, preferably 1 to 4.

[0045] Examples of polyoxyalkylene glycols include polyoxyethylene polyoxypropylene glycols such as polyethylene glycol (polyoxyethylene glycol), polypropylene glycol (polyoxypropylene glycol), poly(ethylene oxide / propylene oxide) block copolymers and poly(ethylene oxide / propylene oxide) random copolymers, and polyoxybutylene glycols such as polytetramethylene glycol.

[0046] Examples of ether compounds of polyoxyalkylenes and polyhydric alcohols include ether compounds of polyoxyalkylenes and polyhydric alcohols such as glycerol, diglycerol, trimethylolpropane, erythritol, pentaerythritol, and bisphenol A, specifically polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, etc. Examples of derivatives in which some or all of the hydrogen atoms of terminal hydroxyl groups have been substituted with alkyl groups or acyl groups include the above-mentioned polyoxyalkylene glycols and derivatives in which some or all of the hydrogen atoms of terminal hydroxyl groups of ether compounds have been substituted with alkyl groups or acyl groups. Specific examples include polyoxyethylene glycol monomethyl ether, polyoxyethylene glycol dimethyl ether, polyoxypropylene glycol monomethyl ether, polyoxypropylene glycol dimethyl ether, polyoxyethylene polyoxypropylene glycol monomethyl ether, polyoxyethylene polyoxypropylene glycol dimethyl ether, polyoxyethylene glycol monobutyl ether, polyoxypropylene glycol monobutyl ether, and polyoxyethylene polyoxypropylene monobutyl ether.

[0047] Among the above-mentioned polyoxyalkylene compounds, those having a polyoxyethylene, polyoxypropylene, or polyoxyethylene polyoxypropylene structure are preferred, and among these, those having a polyoxypropylene or polyoxyethylene polyoxypropylene structure are more preferred. Specifically, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or derivatives thereof in which some of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups are preferred.

[0048] Examples of alcohol-based plasticizers include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, pentaerythritol, etc. Among these, trimethylolpropane is preferred.

[0049] The above plasticizers can be used alone or in combination of two or more. Among the above plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or derivatives thereof in which some of the hydrogen atoms of the terminal hydroxyl groups have been substituted with alkyl groups are preferred, and triethylene glycol-di-2-ethylhexanoate (3GO) is more preferred.

[0050] The content of the plasticizer in the interlayer film (A) is not particularly limited, but is preferably 10 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the polyvinyl acetal resin. When the content of the plasticizer is 10 parts by mass or more, the interlayer film (A) becomes appropriately flexible, improving the adhesiveness of the interlayer film (A) and the penetration resistance of the laminated glass structure. Furthermore, the storage modulus at 90°C tends to be low, and the thickness change tends to be large. On the other hand, when the content of the plasticizer is 100 parts by mass or less, separation of the plasticizer from the interlayer film (A) is prevented, and an excessive decrease in storage modulus and an excessive increase in thickness change can be prevented. The above content of plasticizer is more preferably 15 parts by mass or more, even more preferably 22 parts by mass or more, even more preferably 30 parts by mass or more, and more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, even more preferably 50 parts by mass or less, and particularly preferably 45 parts by mass or less.

[0051] The interlayer film (A) may contain, in addition to the plasticizer, any known additives that are used in combination with polyvinyl acetal resins. That is, the interlayer film (A) may be made of a thermoplastic resin such as a polyvinyl acetal resin, or a thermoplastic resin and a plasticizer, and may also contain additives other than plasticizers that are blended as necessary. Specific examples of additives other than plasticizers include ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, adhesion modifiers, colorants, fluorescent brighteners, and crystal nucleating agents.

[0052] The thickness of the interlayer film (A) is not particularly limited, but is, for example, 100 μm or more and 2000 μm or less, preferably 200 μm or more and 1300 μm or less, and more preferably 300 μm or more and 1000 μm or less. When the thickness of the interlayer film (A) is equal to or greater than the above-mentioned lower limit, it becomes more difficult to cut with a glass cutter, and crime prevention is improved. In addition, impact resistance can be improved, and adhesion to glass and the like can be easily ensured. On the other hand, when the thickness is equal to or less than the above-mentioned upper limit, the thickness of the laminated glass structure can be prevented from becoming thicker than necessary.

[0053] The interlayer film (A) may be a single-layer film having a single layer structure. When the interlayer film (A) is composed of a single layer, the interlayer film (A) of the single layer structure is composed of one resin layer, and this resin layer may have the composition as described above for the interlayer film (A). That is, the resin layer constituting the single-layer interlayer film (A) contains the above-mentioned polyvinyl acetal resin and, if necessary, may contain a plasticizer, and may also contain additives other than the plasticizer and a thermoplastic resin other than the polyvinyl acetal resin as appropriate.

[0054] The interlayer film (A) may be a multilayer film of two or more layers. The multilayer film may have any composition as long as the overall film has the same composition as that described for the interlayer film (A) above. It is preferable that each resin layer (hereinafter also referred to as the "first resin layer") has the same composition as that described for the interlayer film (A). That is, each first resin layer contains a polyvinyl acetal resin, as described for the interlayer film (A), and may optionally contain a plasticizer and may contain additives other than the plasticizer as appropriate. Each first resin layer may optionally further contain a thermoplastic resin other than the polyvinyl acetal resin. Details of the polyvinyl acetal resin, plasticizer, thermoplastic resin other than the polyvinyl acetal resin, additives, and the content of each component in each first resin layer of the multilayer film are as described for the interlayer film (A) above. However, the polyvinyl acetal resin and the total amount of the interlayer film (A) that serve as the basis for the content are the polyvinyl acetal resin contained in each first resin layer and the total amount of the first resin layer, respectively. Each first resin layer should satisfy the above-mentioned storage modulus, and, if necessary, should also satisfy other physical properties (weight average molecular weight, molecular weight distribution, thickness change) besides the storage modulus. In the multilayer film, each first resin layer may have the same composition or different compositions. The multilayer film may also be a laminate of the first resin layer described above and a layer other than the first resin layer (hereinafter also referred to as a "second resin layer"). Specific examples include a three-layer structure of first resin layer / second resin layer / first resin layer. In the layer structure of first resin layer / second resin layer / first resin layer, the second resin layer may be provided in multiple layers. The second resin layer may be a thermoplastic resin layer. The second resin layer may be a thermoplastic resin layer containing a thermoplastic resin other than the above-described polyvinyl acetal resin, for example. The first resin layers preferably occupy a certain proportion of the total thickness of the interlayer film (A). Specifically, the total thickness of the first layers is preferably 0.3 to 1, more preferably 0.5 to 1, and even more preferably 0.75 to 1, of the total thickness of the interlayer film (A).

[0055] The interlayer film (A) may contain a colored layer as described above. When the interlayer film (A) has a single-layer structure, the resin layer (first resin layer) constituting the interlayer film (A) may be a colored layer. When the interlayer film (A) has a multi-layer structure, any of the first resin layers described above may be a colored layer, but any of the second resin layers may also be a colored layer. For example, when the interlayer film (A) has a multilayer structure and includes colored layers, the central first resin layer may be a colored layer, and in this case, the first resin layers on both sides may be clear layers that do not substantially contain a colorant. Furthermore, when the interlayer film (A) has a multilayer structure and includes colored layers, the interlayer film (A) may have a layer structure of clear layer / colored layer / clear layer, for example.

[0056] Furthermore, in the multilayer interlayer film (A) as described above, the colored layer does not need to be provided over the entire region of the interlayer film (A) and may be provided over only a portion of the region. When the colored layer is provided over only a portion of the region, for example, the portion of the region may have a layer structure of clear layer / colored layer / clear layer, and the remaining region may have a laminated structure of clear layer / clear layer. In this case, in the region where the colored layer is not provided, the two second resin layers (clear layers) may be integrated to form a single second resin layer (clear layer).

[0057] The colored layer preferably contains a colorant. The colorant used in the colored layer is not particularly limited, and pigments that have traditionally been incorporated into interlayer films can be used, such as blue, yellow, red, green, purple, white, and black. Pigments, dyes, and the like can be used as the pigment. By using a colorant in the interlayer film (A), the interlayer film (A) can be colored to a desired color, thereby enhancing the design properties of the interlayer film (A).

[0058] Examples of pigments used in the interlayer film (A) include carbon black, copper phthalocyanine pigments such as pigment blue, phthalocyanine pigments such as cobalt phthalocyanine pigments, anthraquinone pigments, perylene pigments, diketopyrrolopyrrole pigments, quinacridone pigments, perinone pigments, thioindigo pigments, isoindoline pigments, isoindolinone pigments, quinophthalone pigments, threne pigments, dioxazine pigments, pyrrocholine pigments, fluorubine pigments, azo pigments, titanium oxide pigments, calcium carbonate pigments, metal oxide pigments, Ni complex pigments, and other metal complex pigments. Examples of the dye include azo dyes, cyanine dyes, triphenylmethane dyes, phthalocyanine dyes, anthraquinone dyes, naphthoquinone dyes, quinoneimine dyes, methine dyes, azomethine dyes, squarylium dyes, acridine dyes, styryl dyes, coumarin dyes, quinoline dyes, and nitro dyes. The dye may be a disperse dye. The pigments and dyes constituting the colorants described above may be blended directly into the resin, or may be blended into the resin in the form of ink, toner, or the like. The content of the colorant in the colored layer is, for example, 0.0001% by mass or more and 2% by mass or less, preferably 0.005% by mass or more and 1% by mass or less, more preferably 0.01% by mass or more and 0.5% by mass or less, and even more preferably 0.02% by mass or more and 0.3% by mass or less, based on the total amount of the colored layer.

[0059] In this specification, a layer that does not substantially contain a colorant may be referred to as a clear layer as described above. The clear layer means that no colorant is intentionally blended, and the specific colorant content in the clear layer is, for example, less than 0.0001% by mass in total, preferably less than 0.00001% by mass, and most preferably 0% by mass.

[0060] The method for producing the interlayer film (A) is not particularly limited, and it may be produced by a conventionally known method, such as extrusion molding or press molding, but production by extrusion molding is preferred. The interlayer film (A) may also have an uneven shape on one or both surfaces. The method for forming the uneven shape is not particularly limited, and examples thereof include lip embossing, embossing roll, and calender roll.

[0061] <First and second glass> In the laminated glass structure of the present invention, at least one of the first and second glasses has a Mohs hardness of 5.5 or more. If the Mohs hardness of both the first and second glasses is less than 5.5, the laminated glass structure can be easily cut with a glass cutter after being broken by fire, making it difficult to achieve excellent burglary prevention. From the viewpoint of improving burglary prevention, it is preferable that both the first and second glasses have a Mohs hardness of 5.5 or more. From the viewpoint of security, it is preferable that the Mohs hardness of at least one of the first and second glasses is 6.0 or higher, and more preferably 6.5 or higher. While it is sufficient for either one of the first and second glasses to be equal to or higher than the lower limit, it is more preferable that both be equal to or higher than the lower limit. The upper limit of the Mohs hardness is not particularly limited, but is, for example, 8. The Mohs hardness can be adjusted as appropriate by, for example, the glass material or the surface treatment of the glass.

[0062] Mohs hardness can be measured using a Mohs hardness scale. Standard materials are set for integer values ​​from 1 to 10, and when the material being tested is scratched with the standard material, the relative hardness (number) can be determined based on whether or not a scratch is left. The Mohs hardness can be determined by measuring the Mohs hardness of one of the glass surfaces. In the case of window glass for vehicles such as automobiles, it is preferable that at least the surface of the glass facing the exterior (i.e., the vehicle exterior) has the above-mentioned Mohs hardness. Therefore, it is more preferable that the Mohs hardness of the glass surfaces facing the same direction of the first and second glass panes is within the above-mentioned predetermined range. In the first and second embodiments described below, for example, it is more preferable that the Mohs hardness of the outer surface 11A of the first glass pane 11 and the inner surface 12B of the second glass pane 12 is at least within the above-mentioned predetermined range (see FIGS. 1 and 2). However, it is even more preferable that the Mohs hardness of both the first and second glass panes 11 and 12 is within the above-mentioned range.

[0063] Glass plates can be used as the first and second glasses. The glass plates may be either inorganic glass or organic glass, but inorganic glass is preferred from the viewpoint of improving Mohs hardness. Examples of inorganic glass include, but are not limited to, various types of tempered glass such as clear glass, float glass, and tempered float glass, colored glass, polished plate glass, figured glass, wired plate glass, ultraviolet absorbing glass, heat ray reflecting glass, heat ray absorbing glass, and green glass. Among these, glass other than heat-absorbing glass is preferred from the viewpoint of high resistance to breakage by fire. Furthermore, these inorganic glasses may be subjected to a surface treatment such as glass coating as appropriate. The surface treatment makes it easier to increase the Mohs hardness.

[0064] As the organic glass, what is generally called resin glass is used, and examples thereof include various organic glass plates such as polycarbonate plates, (meth)acrylic plates such as polymethyl methacrylate plates, polyester plates such as acrylonitrile-styrene copolymer plates, acrylonitrile-butadiene-styrene copolymer plates, polyethylene terephthalate plates, fluorine-based resin plates, polyvinyl chloride plates, chlorinated polyvinyl chloride plates, polypropylene plates, polystyrene plates, polysulfone plates, epoxy resin plates, phenolic resin plates, unsaturated polyester resin plates, polyimide resin plates, etc. The organic resin plates may be subjected to appropriate surface treatments, etc.

[0065] The first and second glasses may be made of the same material or different materials, for example, one may be inorganic glass and the other organic glass, but it is more preferable that both the first and second glasses are inorganic glasses. The thickness of each of the glass plates used for the first and second glasses is not particularly limited, but is, for example, about 0.1 to 15 mm, preferably 0.5 to 5 mm. The thicknesses of the glass plates may be the same or different from each other.

[0066] At least one of the first and second glasses may have a colored layer. The colored layer is a coating formed on the surface of at least one of the first and second glasses, and may take any form as long as it contains a colorant. The coating may contain a binder component such as a thermosetting resin or a thermoplastic resin, as necessary, and may further contain additives as appropriate. Details of the colorant are as described above. However, in the laminated glass structure, the colored layer may be provided on a layer other than the first and second glasses and the interlayer film (A). For example, the colored layer may be provided as a layer separate from the interlayer film (A). For example, the colored layer may be provided on an interlayer film other than the interlayer film (A).

[0067] <Light control film> The laminated glass structure of the present invention may contain a light control film as described above. The light control film is a film-like component having a light control element. The light control element preferably comprises a resin film and a light control layer, and more specifically, the light control film preferably comprises two resin films and a light control layer disposed between the two resin films. Therefore, the adhesive surface of the light control film with the interlayer film (A) is preferably made of a resin material (resin film), which tends to increase the adhesive strength to the interlayer film (A). Resin films used in light-control elements are not particularly limited, but examples include polyester resin films such as PET (polyethylene terephthalate resin) film and PEN (polyethylene naphthalate resin) film, (meth)acrylic resin film, TAC film, PES resin film, and polyimide resin film. Among these, polyester resin films are preferred from the viewpoint of ease of handling, and PET film is more preferred. The PET film enhances versatility, while its hardness makes it difficult to cut with a glass cutter, thereby improving security. In addition, each of the two resin films is preferably provided with a conductive layer that forms an electrode on the surface facing the light-control layer.

[0068] The light-controlling layer changes its visible light transmittance by switching between applying and not applying a voltage between the conductive layers of two resin films. The light-controlling layer is composed of a liquid crystal layer such as a polymer-dispersed liquid crystal (PDLC), and the light-controlling film may be a PDLC film. The light-controlling film may also be an SPD (Suspended Particle Device) film, an electrochromic film, an electrophoretic film device, a GHLC (Guest-Host Liquid Crystal) film, or the like. Therefore, the light-controlling layer may be an SPD layer containing a resin matrix and a light-controlling suspension dispersed in the resin matrix, an electrochromic material layer, or an electrophoretic layer containing electrophoretic particles and a dispersant for dispersing the electrophoretic particles. Alternatively, the light-controlling layer may be a layer composed of host molecules and guest molecules. When the laminated glass structure has a light control layer, the light control layer is preferably disposed between two interlayer films, as described below. The thickness of the light control film is not particularly limited, but is, for example, 0.01 mm or more and 0.50 mm or less, preferably 0.01 mm or more and 0.20 mm or less, and more preferably 0.02 mm or more and 0.10 mm or less.

[0069] [Layer structure of laminated glass structure] Next, the layer structure of the laminated glass structure will be described in detail with reference to the drawings and embodiments. As shown in Fig. 1, in a first embodiment of the present invention, the laminated glass structure is a laminated glass structure 10 in which an interlayer film 13 is provided between first and second glass panes 11 and 12. In the laminated glass structure 10, the interlayer film 13 is adhered to both the first and second glass panes 11 and 12 to join them together. In this embodiment, the interlayer film 13 is the interlayer film (A) described above.

[0070] In this embodiment, it is preferable that at least one of the interlayer film 13 and the first and second glass panes 11 and 12 has a colored layer. Therefore, at least one of the first and second glass panes 11 and 12 may have a colored layer. In this case, the colored layer may be provided on the surface of the first and second glass panes 11 and 12 facing the interlayer film 13 (inner surfaces 11B and 12B), or on the surface of the glass panes 11 and 12 opposite the surface facing the interlayer film 13 (outer surfaces 11A and 12A). In this embodiment, the interlayer film (A) may of course have a colored layer. The design of the laminated glass structure can be improved by having a colored layer.

[0071] In another preferred embodiment, the laminated glass structure may have a plurality of interlayer films provided between the first and second glass panes. When a plurality of interlayer films are provided, it is preferable that all of the interlayer films are the above-described interlayer film (A) from the viewpoint of further enhancing security. However, it is also possible that at least one interlayer film is the above-described interlayer film (A) and the remaining interlayer films are not the above-described interlayer film (A). That is, it is also possible that at least one interlayer film has a storage modulus at 90°C of 1.0 × 10 5 Pa or more 2.9×10 5 The storage modulus of the remaining interlayer at 90°C is 1.0 × 10 5 Pa or more 2.9×10 5 It does not have to be less than Pa. The storage modulus at 90°C of the interlayer films other than interlayer film (A) was 1.0 × 10 5 Pa or more 2.9×10 5 There are no particular limitations on the film thickness as long as it is not more than Pa, and any known film may be used, but a thermoplastic resin film is preferred, and a film using polyvinyl acetal resin as the thermoplastic resin in the thermoplastic resin film is preferred.

[0072] One embodiment of a laminated glass structure in which multiple interlayer films are provided is shown as a second embodiment in Figure 2. As shown in Figure 2, a laminated glass structure 20 according to the second embodiment has interlayer films 13A and 13B provided between first and second panes 11 and 12, and a light control film 14 further provided between the interlayer films 13A and 13B. As described above, it is preferable that both interlayer films 13A and 13B be the above-mentioned interlayer film (A), but either one of them does not have to be the interlayer film (A). In the laminated glass structure 20, the interlayer 13A is adhered to both the first glass 11 and the light control film 14, joining them together, and the interlayer 13B is adhered to both the second glass 12 and the light control film 14, joining them together. As a result, the first and second glass sheets 11, 12, together with the light control film 14, are integrated by the interlayers 13A, 13B.

[0073] In the second embodiment, two interlayer films and one light control film are provided, but three or more interlayer films and two or more light control films may be provided. In this case, the interlayer films and the light control films may be arranged alternately in the first and second glass. In this case, all of the interlayer films may be the above-mentioned interlayer film (A), but some of the interlayer films may be the above-mentioned interlayer film (A) and the remaining interlayer films may be interlayer films other than the interlayer film (A). When a plurality of interlayer films are provided in the laminated glass structure, the configurations of the interlayer films may be the same or different.

[0074] <Method of manufacturing laminated glass structure> The laminated glass structure of the present invention may be produced by a production method in which at least an interlayer film (A) is placed between a first glass sheet and a second glass sheet, and these sheets are bonded together by pressure to obtain a laminated glass structure.

[0075] In the above manufacturing method, first, first and second glass sheets and a member to be placed between the first and second glass sheets (for example, an interlayer film, or a light control film and an interlayer film) are prepared. Here, the member placed between the first and second glass panes may be selected appropriately depending on the structure of the resulting laminated glass structure; for example, in the first embodiment, a single interlayer film may be prepared. Also, in the second embodiment, for example, two interlayer films and one light control film may be prepared. When a light control film is used, the light control film and the interlayer film may be placed between the first and second glass panes as separate members, or they may be integrated by pressing or the like beforehand and placed between the first and second glass panes.

[0076] In the present manufacturing method, an interlayer film, or an interlayer film and a light control film, or the like, is disposed between the first glass and the second glass as described above, and these are bonded together to form an integrated laminated glass structure. Here, the interlayer film, or the interlayer film and the light control film, may be arranged according to the layer structure of the resulting laminated glass structure. For example, in the second embodiment, the interlayer film, the light control film, and the interlayer film may be arranged between the first and second glass panes in this order.

[0077] The lamination may be performed using a vacuum bag, an autoclave, or a press other than these, but among these, the vacuum bag is preferred. Furthermore, before the lamination, temporary pressure bonding may be performed using a rubber roll or the like.

[0078] In the present production method, the lamination is preferably carried out under low-temperature, low-pressure conditions, specifically, preferably at a temperature of 110°C or less and a pressure of 1.2 MPa or less. By laminating under low-temperature, low-pressure conditions in this way, it is possible to prevent the light control film from deteriorating or becoming inactive. Furthermore, in the present invention, even when the films are integrated at low temperature and low pressure, if an interlayer film (A) with a large amount of thickness change is used as described above, it is possible to prevent poor or deteriorated appearance due to remaining air or bubbles.

[0079] The temperature during lamination is preferably 100°C or lower from the viewpoint of more reliably preventing deterioration or deactivation of the light-controlling film, and is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of preventing the generation of residual air or foaming. Furthermore, the pressure during lamination is preferably 1.0 MPa or less from the viewpoint of more reliably preventing deterioration or deactivation of the light control film. When lamination is performed under negative pressure, such as when using a vacuum bag, the pressure may be, for example, 0.095 MPa or less, preferably 0.08 MPa or less, and more preferably 0.06 MPa or less. The lower limit of the pressure when laminating is not particularly limited, but when laminating under pressure such as in an autoclave, the pressure is preferably 0.5 MPa or more, more preferably 0.7 MPa or more. When laminating under negative pressure such as in a vacuum bag, the pressure is preferably 0.001 MPa or more, more preferably 0.005 MPa or more. The time for lamination under the above temperature and pressure is not particularly limited, but is, for example, 5 to 120 minutes, and preferably 10 to 60 minutes. However, the temperature, pressure, and time when laminating are not limited to those described above, and lamination may be carried out under conventional lamination conditions for interlayer films as appropriate.

[0080] The laminated glass structure of the present invention can be used for a variety of purposes without any particular limitation, but is used as window glass for various vehicles such as automobiles and trains, ships, and airplanes, various buildings such as buildings, condominiums, detached houses, halls, and gymnasiums, machine tools for cutting and polishing, construction machines such as shovels and cranes, and partitions inside various vehicles and buildings. Among these, it is preferably used for purposes requiring crime prevention, and particularly for vehicle applications such as automobiles, and more preferably used as window glass for vehicles, particularly automobiles. Furthermore, in automobiles, the structure for laminated glass of the present invention may be applied to any of windshield, rear glass, side glass, and roof glass, but is preferably applied to glass to which a light control film or a colored layer is suitably applied. Therefore, the structure for laminated glass is preferably applied to any of rear glass, side glass, and roof glass among these, and more preferably applied to roof glass attached to the roof of an automobile. [Example]

[0081] The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The methods for measuring and evaluating the various physical properties in the present invention are as follows.

[0082] <Amount of hydroxyl groups, degree of acetylation, degree of acetalization> Measurement of ethylene group content (mass%) with hydroxyl groups 0.4 g of sample was weighed into a 200 mL Erlenmeyer flask with a stopper. 10.0 mL of pyridine-acetic anhydride mixture was added to the sample, and the mixture was heated and sonicated in a 90°C water bath to dissolve the sample in the pyridine-acetic anhydride mixture. A reflux condenser was attached to the Erlenmeyer flask, and the mixture was heated and refluxed in the water bath for 120 minutes. After the reaction, the condenser was rinsed with 25 mL of pyridine, and the reaction solution was cooled to room temperature. 20 mL of 1,2-dichloroethane was added to the cooled sample solution, followed by shaking. 50 mL of water was then added, followed by shaking, and the mixture was left at room temperature for 30 minutes. The sample solution was then potentiometrically titrated with 0.5 mol / L (0.5 N) sodium hydroxide solution. A blank test was performed in the same manner, except that no sample was used. The content (mass %) of ethylene groups bound to hydroxyl groups in the sample was calculated using the following formula:

number

[0083] Measurement of ethylene group content (mass%) with acetyl groups 0.4 g of sample was weighed into a 200 mL Erlenmeyer flask with a stopper. 100 mL of ethanol was added to the sample, and the sample was dissolved in ethanol by heating and ultrasonication in a water bath at 90 °C. While shaking the Erlenmeyer flask, 10 mL of 0.2 mol / L (0.2 N) sodium hydroxide was added. A reflux condenser was attached to the Erlenmeyer flask, and the mixture was heated and refluxed in a water bath for 60 minutes. After the reaction, the condenser was rinsed with 25 mL of ethanol, and the reacted sample solution was cooled to room temperature. 10 mL of 0.2 mol / L (0.2 N) hydrochloric acid was added to the cooled sample solution, shaken well, and allowed to stand at room temperature for 30 minutes. The sample solution was then subjected to potentiometric titration with 0.1 mol / L (0.1 N) sodium hydroxide solution. A blank test was performed in the same manner, except that no sample was used. The content (mass%) of acetyl-bonded ethylene groups in the sample was calculated using the following formula:

number

[0084] Measurement of the content (mass%) of ethylene groups bound to butyral groups The content (mass%) of ethylene groups bonded to butyral groups was calculated based on the following formula using the content (mass%) of ethylene groups bonded to hydroxyl groups and the content (mass%) of ethylene groups bonded to acetyl groups determined by the above-mentioned methods.

number

[0085] Hydroxyl group amount, acetylation degree, acetalization degree (butyralization degree) The hydroxyl group amount (mol %), acetylation degree (mol %), and acetalization degree (mol %) were calculated based on the following formulas using the content of ethylene groups bonded to hydroxyl groups, the content of ethylene groups bonded to acetyl groups, and the content of ethylene groups bonded to butyral groups determined by the above-mentioned methods.

number

number

number

[0086] <Thickness change when compressive creep test is performed> According to the method described in the specification, the interlayer film of each example and comparative example was cut out to prepare a test sample with a diameter of 8 mm. The thickness change of the prepared test sample was determined according to the method described in the specification.

[0087] <Storage modulus> The interlayer films obtained in the examples and comparative examples were stored for 12 hours in an environment with a room temperature of 23±2°C and a humidity of 25±5%, and the viscoelasticity was measured under the following measurement conditions using a dynamic viscoelasticity device (manufactured by TA Instruments, product name "ARES-G2", jig "8 mm diameter parallel plate") to determine the shear storage modulus (G') at 90°C. (Measurement conditions) Deformation mode: shear mode, measurement temperature: -10℃~100℃, heating rate: 3℃ / min, measurement frequency: 1Hz, strain: 1%

[0088] <Glass transition temperature (Tg)> The obtained polyvinyl acetal resin was molded into a film 10 mm long and 5 mm wide using a heat press, and the viscoelasticity was measured under the following measurement conditions using a dynamic viscoelasticity measuring device (manufactured by IT Measurement & Control Co., Ltd., product name "DVA-200"). The peak temperature of the loss tangent tanδ obtained from the viscoelasticity measurement results was read. The first peak temperature counting from the low temperature side in the temperature range of -50 to 150°C was taken as the glass transition temperature (Tg) of the polyvinyl acetal resin. (Measurement conditions) Deformation mode: shear mode, measurement temperature: -50℃ to 200℃, heating rate: 5℃ / min, measurement frequency: 1Hz, strain: 1%

[0089] <Softening point> The softening point of the obtained polyvinyl acetal resin was measured in accordance with JIS K7206 under conditions of a temperature rise rate of 50°C / hour and a test load of 50N.

[0090] <Molecular weight (Mw, Mn)> The interlayer film used in each example and comparative example was dissolved at a concentration of 0.05% by mass in N-methyl-2-pyrrolidone solution to which lithium bromide had been added to make a 10 mM solution. The solution was filtered using a syringe filter (Merck, Millex-LH 0.45 μm) and then subjected to molecular weight measurement using gel permeation chromatography (Waters, e2690). The number-average molecular weight (Mn) and weight-average molecular weight (Mw) were calculated using a molecular weight calibration curve prepared using monodisperse polystyrene standard samples, and the molecular weight distribution (Mw / Mn) was also determined. A Shodex GPC KF-806L (Showa Denko) column was used, and N-methyl-2-pyrrolidone solution to which lithium bromide had been added to make a 10 mM solution was used as the eluent.

[0091] <Evaluation: Crime prevention> For the laminated glass structures obtained in the Examples and Comparative Examples, heat was applied to the glass surface with a burner to cause thermal expansion, and then rapid cooling was performed to shrink the laminated glass structure and break the glass, and the security properties were evaluated. After breaking the glass, pieces that were difficult to cut with one type of glass cutter (GIYAMAN's "Glass Cutter PRO" blade uses tungsten, Mohs hardness 7.5) were rated as "A," pieces that could be cut with one type of glass cutter but took time were rated as "B," and pieces that could be cut easily with one type of glass cutter were rated as "C."

[0092] The thermoplastic resins used in the examples and comparative examples were prepared as follows. (Resin 1) A reactor equipped with a stirrer was charged with 1800 ml of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol%), and the mixture was heated and dissolved while stirring to obtain a polyvinyl alcohol solution. Next, 30% hydrochloric acid was added as a catalyst to this solution so that the hydrochloric acid concentration was 0.2% by mass. The temperature was then adjusted to 15°C, and n-butyl aldehyde was added with stirring so that the concentration was 10 mol%. Subsequently, n-butyl aldehyde was added so that the concentration was 60 mol%, resulting in the precipitation of a white granular polyvinyl butyral resin. Ten minutes after the precipitation, 30% hydrochloric acid was added so that the hydrochloric acid concentration was 1.8% by mass. The temperature was then raised to 53°C, and the mixture was aged at this aging temperature for 2 hours. Next, the solution was cooled and neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 1 (polyvinyl butyral resin, hydroxyl group content 30.3 mol%, acetalization degree 68.5 mol%, acetylation degree 1.2 mol%).

[0093] (Resin 2) Instead of blending 200 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol%), 140 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol%) and 60 g of polyvinyl alcohol B (average degree of polymerization 500, degree of saponification 99 mol%) were blended. Otherwise, resin 2 (polyvinyl butyral resin, hydroxyl group content 30.4 mol%, degree of acetalization 68.8 mol%, degree of acetylation 0.8 mol%) was obtained in the same manner as resin 1.

[0094] (Resin 3:EVA) Ethylene-vinyl acetate copolymer resin (product name "EV40W" manufactured by DuPont-Mitsui Chemicals Co., Ltd., vinyl acetate content 41% by mass) (Resin 4: Acrylic resin) An acrylic resin prepared by the method shown in Comparative Example 3 below was used.

[0095] The plasticizers used in the examples and comparative examples are as follows. 3GO: Triethylene glycol-di-2-ethylhexanoate DGP: Polyoxypropylene diglyceryl ether, "Unilube DGP-700", manufactured by NOF Corporation, number average molecular weight 700 PPG: Polypropylene Glygol, "PPG1000", manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., hereinafter referred to as "PPG1000", number average molecular weight is 1000

[0096] The light control films used in the examples and comparative examples were as follows. Dimming 1: SPD film, "LCF-1103DHA30", manufactured by Showa Denko Dimming 2: SPD film, "LCF-1103DHA90," manufactured by Showa Denko Dimming 3: PDLC film, "MIYO Film" manufactured by Kyushu Nanotec Optics Co., Ltd. Dimming 4: PDLC film, "LCMSGIC," manufactured by Toppan Printing Co., Ltd.

[0097] The glasses used in the examples and comparative examples were as follows: Glass 1: Float glass, Mohs hardness 6.0 (both sides) Glass 2: Tempered float glass, Mohs hardness 5.5 (both sides) Glass 3: Tempered float glass, Mohs hardness 5.0 (both sides)

[0098] Example 1 A resin composition was obtained by mixing 100 parts by mass of resin 1 with 40 parts by mass of plasticizer (triethylene glycol-di-2-ethylhexanoate: 3GO). The obtained resin composition was used in a hydraulic press and an 800 μm-thick spacer to produce an interlayer film with a thickness of 800 μm. Two 2.5 mm sheets of glass 1 and the light control film shown in Table 1 were also prepared. Next, an interlayer film (first interlayer film), a light control film, and an interlayer film (second interlayer film) were laminated in this order on one of the glasses 1, and the other glass 1 was then laminated on top of the interlayer film to obtain a laminate. The laminate was pressed under the following lamination conditions to obtain a laminated glass structure.

[0099] (Lamination conditions) The laminate was placed in a rubber bag, which was a vacuum bag, and degassed for 5 minutes at a vacuum pressure of 0.09 MPa. Next, while still degassed, the laminate was heated to 90°C at a heating rate of 1°C / min, held at 90°C for 30 minutes, and then cooled to 30°C. Next, the pressure was returned to normal, and a laminated glass structure was obtained.

[0100] Examples 2 to 4 The same procedure as in Example 1 was carried out except that the light-control film was changed as shown in Table 1.

[0101] Examples 5 to 7 The same procedure as in Example 1 was carried out except that the amount and type of plasticizer used were changed as shown in Table 1.

[0102] (Examples 8 to 11) The same procedures as in Examples 1 to 4 were carried out except that the thermoplastic resin used was changed to Resin 2.

[0103] (Example 12, Comparative Example 1) The same procedure as in Example 8 was carried out, except that the glass shown in Table 1 was used instead of Glass 1.

[0104] (Comparative Example 2) Except for changing the resin used to Resin 3 and not using a plasticizer, an interlayer film with a thickness of 800 μm was produced in the same manner as in Example 8. Using the obtained interlayer film, a laminated glass structure consisting of Glass 1 / Interlayer film (first interlayer film) / Light control film / Interlayer film (second interlayer film) / Glass 1 was produced.

[0105] (Comparative Example 3) 20 parts by mass of n-butyl acrylate (BA), 78 parts by mass of 2-ethylhexyl acrylate (EHA), 2 parts by mass of acrylic acid (Aac), and 5 parts by mass of 2-methacryloyloxyethyl isocyanate (MOI) were mixed in a stirring vessel. The mixture was stirred at 2000 rpm for 9 minutes using a planetary centrifugal mixer (Thinky Corporation's "Awatori Rentaro ARE-310"), and then degassed for 3 minutes at 2200 rpm. This process was repeated until the mixture became homogeneous, yielding a liquid curable resin material.

[0106] A PET release film (product name "PET50x1-C", manufactured by Nippa Corporation) was adhered to the top surface of the coated glass with ethyl acetate, with the release-treated side facing up. The curable resin material obtained above was applied to the release-treated side of the PET release film, and then spacers were placed on two edges of the PET release film so that the cured product would have a predetermined thickness. An ultraviolet-transmitting glass of the same size as the coated glass was prepared, and the film was adhered to the ultraviolet-transmitting glass with ethyl acetate, so that the release-treated side of the PET release film was also exposed on the ultraviolet-transmitting glass. The curable resin material and spacers were sandwiched between the coated glass and the ultraviolet-transmitting glass, and the ultraviolet-transmitting glass was placed on top of the curable resin material with the release-treated side of the PET release film facing inward. Then, an ultraviolet irradiator was used to apply an illuminance of 3 mW / cm2 from above the ultraviolet-transmitting glass. 2 The irradiation dose is 900mJ / cm 2The curable resin material was cured by irradiating it with ultraviolet light so that the curable resin material was cured to obtain an interlayer film. The thickness of the interlayer film was 0.8 mm. Using the obtained interlayer film, a laminated glass structure consisting of glass 1 / interlayer film (first interlayer film) / light control film / interlayer film (second interlayer film) / glass 1 was produced.

[0107] [Table 1]

[0108] The laminated glass structures of Examples 1 to 12 described above have glass Mohs hardness of 5.5 or more, interlayer films containing polyvinyl acetal resin, and storage moduli at 90°C of 1.0 × 10 5 Pa or more 2.9×10 5 Since the strength was less than 100 Pa, even if the laminated glass structure was broken by burning it took time for the structure to break, providing excellent security against crime. In contrast, in Comparative Example 1, the Mohs hardness of the glass was lower than 5.5, so the interlayer film was easily cut with a glass cutter, and it did not take long for the laminated glass structure to break, resulting in poor security. In addition, Comparative Examples 2 and 3 had a storage modulus of 1.0 × 10 at 90°C. 5 Pa or more 2.9×10 5 Since the strength was outside the range of tensile strength (Pa) or less, the interlayer film was easily cut with a glass cutter. Therefore, it did not take long for the laminated glass structure to break, and the anti-theft performance was not good. [Explanation of symbols]

[0109] 10, 20 Laminated glass structure 11, 12 Glass 13, 13A, 13B Intermediate film 14 Light control film

Claims

1. A laminated glass structure comprising first and second glass panes, and an interlayer film (A) having at least one resin layer between the first and second glass panes, wherein the laminated glass structure has at least one of a light control film and a colored layer; At least one of the first and second glasses has a Mohs hardness of 5.5 or more, the interlayer film (A) contains a polyvinyl acetal resin, and the storage modulus of the interlayer film (A) at 90°C is 1.0 × 10 ５ Pa or more 2.9×10 ５ Pa or less.

2. 2. The laminated glass structure according to claim 1, wherein the polyvinyl acetal resin has a glass transition temperature of −10° C. or higher and 50° C. or lower.

3. 3. The laminated glass structure according to claim 1, wherein the polyvinyl acetal resin has a softening point of 50°C or higher and 120°C or lower.

4. The laminated glass structure according to claim 1 or 2, wherein the light management film comprises a PET film.

5. 3. The laminated glass structure according to claim 1, wherein the first and second glass sheets are not heat-absorbing glass sheets.

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