Interlayer film for laminated glass, laminate, and optical laminate

Abstract

Provided are an interlayer film for laminated glass, a laminate including the interlayer film for laminated glass, and an optical laminate including the interlayer film for laminated glass or the laminate, which can suppress a decrease in transmittance and a decrease in adhesive strength generated by an autoclave process under low temperature conditions. 【Solution means】The present invention is an interlayer film for laminated glass having a single-layer structure or a multilayer structure, including at least a thermoplastic resin layer (A) containing a thermoplastic resin. When the interlayer film for laminated glass has a multilayer structure, at least one outermost layer is a thermoplastic resin layer (A), and the average value of the average values of the adhesive strengths of all samples in a predetermined preliminary adhesion test is 20 N or more. The laminate 50 of the present invention includes the interlayer film 10 for laminated glass of the present invention and a functional layer 40 different from the interlayer film 10 for laminated glass. The optical laminate 1B of the present invention includes a first transparent substrate 20, a second transparent substrate 30, and the interlayer film 10 for laminated glass of the present invention or the laminate 50 of the present invention.

Description

Technical Field

[0001] The present invention relates to an interlayer for laminated glass, a laminate including the interlayer for laminated glass, and an optical laminate including the interlayer for laminated glass or the laminate.

Background Art

[0002] Conventionally, laminated glass in which an interlayer is interposed between two glass plates and integrated is widely known. The interlayer is often formed of a plasticized polyvinyl acetal in which a plasticizer is blended with a polyvinyl acetal resin. Since laminated glass is safe because glass fragments are less likely to scatter even when it is damaged by an external impact, it is widely used as window glass for vehicles such as automobiles, airplanes, and buildings.

[0003] For laminated glass, an interlayer is disposed between two glass plates, and after a preliminary degassing process, it is heated and pressurized under conditions of a temperature of about 130 to 140 ° C and a pressure of about 1.3 MPa in an autoclave (ACV) process to bond the glass and the interlayer for manufacturing. In addition, various studies and improvements have been made on the interlayer for laminated glass. Patent Document 1 shows an interlayer for laminated glass in which the amount of change in thickness when a compression creep test is performed is within a certain range.

[0004] In recent years, laminated glass has sometimes been required to be provided with various functions. For example, a functional film such as a light control film may be disposed between two glass plates. When a functional film such as a light control film is incorporated into laminated glass, it is known to dispose an interlayer between the functional film and each glass plate and integrate the two glass plates and the functional film via the interlayer (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, functional films such as light control films are vulnerable to heat. When a glass plate, an intermediate film, and a functional film are pressure-bonded under conventional high-temperature and high-pressure conditions using an autoclave, the functional film often loses its activity. There is also a problem that it is necessary to heat to a high temperature and the amount of carbon dioxide emissions is large. On the other hand, if an attempt is made to perform pressure bonding using an autoclave at a low temperature, air may remain between the intermediate film and the glass plate or between the intermediate film and the functional film during pressure bonding, and the transparency of the laminated glass obtained by pressure bonding may deteriorate. Further, if an attempt is made to perform pressure bonding using an autoclave at a low temperature, the adhesive force between the intermediate film and the glass plate may be insufficient.

[0007] Therefore, an object of the present invention is to provide an intermediate film for laminated glass that can suppress a decrease in transmittance and a decrease in adhesive force generated in an autoclave process under low-temperature conditions, a laminate including the intermediate film for laminated glass, and an optical laminate including the intermediate film for laminated glass or the laminate. [Means for Solving the Problems]

[0008] As a result of intensive studies, the present inventors examined preliminary adhesion performed before the autoclave process at a low temperature. As a result, it was found that in preliminary adhesion, it is necessary to enhance the adhesiveness between the intermediate film for laminated glass and the glass plate so that no air remains between the intermediate film for laminated glass and the glass plate. Based on such findings, the present inventors have found that the above problems can be solved by using an intermediate film for laminated glass having an adhesive force measured by a predetermined preliminary adhesion force test of a predetermined value or more, and completed the following present invention. That is, the present invention provides the following [1] to [9].

[0009] [1] An interlayer for laminated glass having a single-layer structure or a multi-layer structure, at least including a thermoplastic resin layer (A) containing a thermoplastic resin, when the interlayer for laminated glass has a multi-layer structure, at least one outermost layer is the thermoplastic resin layer (A), An interlayer for laminated glass in which the average value of the adhesive forces of all samples in a preliminary adhesion test conducted under the following conditions is 20 N or more. (Preliminary adhesion test conditions) Prepare two glass plates with a size of 30 cm × 30 cm, an easy - adhesive PET film with a size of 30 cm × 42 cm having easy - adhesiveness on one side, an ultra - thin film PET film with a size of 30 cm × 15 - 17 cm, and the intermediate film for laminated glass with a size of 30 cm × 30 cm. Arrange them such that the easy - adhesive surface of the easy - adhesive PET film contacts the intermediate film for laminated glass, and the thermoplastic resin layer (A) of the intermediate film for laminated glass contacts the glass plate and the ultra - thin film PET film. At this time, in the range from the longitudinal end of the easy - adhesive PET film to a distance of 20 cm in the longitudinal direction of the easy - adhesive PET film, stack the two glass plates, the easy - adhesive PET film, the ultra - thin film PET film, and the intermediate film for laminated glass so that the structure is glass plate / easy - adhesive PET film / intermediate film for laminated glass / glass plate. In the range from the position 20 cm from the longitudinal end of the easy - adhesive PET film to the position 30 cm from the longitudinal end of the easy - adhesive PET film in the longitudinal direction of the easy - adhesive PET film, stack them so that the structure is glass plate / easy - adhesive PET film / intermediate film for laminated glass / thin film PET film / glass plate. At that time, stack them so that the tin surface of the glass contacts the intermediate film for laminated glass. Then, perform vacuum pumping at an absolute pressure of 0.09 MPa for 5 minutes at room temperature. Then, heat up at a heating rate of 6 °C / min to 90 °C, and after reaching 90 °C, cool down to room temperature. Then, after peeling the glass plate that was in contact with the easy - adhesive PET film from the easy - adhesive PET film, cut the laminated film of the easy - adhesive PET film and the intermediate film for laminated glass along the longitudinal direction of the easy - adhesive PET film so that the length in the width direction is 25 mm, and prepare 12 samples for the peel test having a width of 25 mm and adhered to the glass. Then, for each sample, perform a 180° peel test of peeling the sample from the glass plate along the longitudinal direction at a peeling speed of 300 mm / min. At this time, when the displacement at the point where the sample starts to peel from the glass plate is set to 0 mm, the average value of the adhesive force between displacements of 20 - 180 mm is taken as the adhesive force of that sample. [2] When the lower limit value of the adhesive strength between displacements of 20 to 180 mm with the displacement at the point where the sample starts to peel off from the glass plate being set to 0 mm in the preliminary adhesion test is taken as the lower limit value of the adhesive strength of the sample, in the preliminary adhesion test, the minimum value of the lower limit values of the adhesive strength of all samples is 12 N or more. The interlayer film for laminated glass according to claim 1 of the above [1]. [3] The interlayer film for laminated glass according to the above [1] or [2], which contains a colorant. [4] The interlayer film for laminated glass according to any one of the above [1] to [3], wherein the thermoplastic resin layer (A) contains a polyvinyl acetal resin and a plasticizer. [5] The interlayer film for laminated glass according to the above [4], wherein the content of the plasticizer is 30 to 55 parts by mass with respect to 100 parts by mass of the polyvinyl acetal resin. [6] The interlayer film for laminated glass according to the above [4] or [5], wherein the plasticizer is at least one plasticizer selected from the group consisting of an organic ester plasticizer and an organic ether plasticizer. [7] The interlayer film for laminated glass according to any one of the above [1] to [6], and a laminate including a functional layer different from the interlayer film for laminated glass. [8] An optical laminate including a first transparent substrate, a second transparent substrate, and the interlayer film for laminated glass according to any one of the above [1] to [6] disposed between the first and second transparent substrates. [9] An optical laminate including a first transparent substrate, a second transparent substrate, and the laminate according to the above [7] disposed between the first and second transparent substrates.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide an interlayer film for laminated glass that can suppress a decrease in transmittance and a decrease in adhesive strength generated by an autoclave process under low-temperature conditions, a laminate including the interlayer film for laminated glass, and an optical laminate including the interlayer film for laminated glass or the laminate.

Brief Description of the Drawings

[0011]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0012] <Interlayer film for laminated glass> The interlayer film for laminated glass of the present invention is a thermoplastic resin film having a single-layer structure or a multilayer structure, and at least includes a thermoplastic resin layer (A) containing a thermoplastic resin. When the thermoplastic resin film has a multilayer structure, at least one outermost layer is the thermoplastic resin layer (A). And, the interlayer film for laminated glass of the present invention has an average value of the adhesion force of all samples in the preliminary adhesion test carried out under the following conditions of 20 N or more.

[0013] (Preliminary adhesion test conditions) Prepare two glass plates sized 30 cm × 30 cm, an easy - adhesion PET film sized 30 cm × 42 cm with easy - adhesion on one side, an ultra - thin film PET film sized 30 cm × 15 - 17 cm, and an interlayer film for laminated glass sized 30 cm × 30 cm. Next, laminate the two glass plates, the easy - adhesion PET film, the ultra - thin film PET film, and the interlayer film for laminated glass. At this time, laminate them such that the thermoplastic resin layer (A) of the interlayer film for laminated glass is in contact with the glass plate and the easy - adhesion surface of the easy - adhesion PET film is in contact with the interlayer film for laminated glass. Also, in the range from the longitudinal end of the easy - adhesion PET film to a distance of 20 cm in the longitudinal direction of the easy - adhesion PET film, make the structure be glass plate / easy - adhesion PET film / interlayer film for laminated glass / glass plate. Further, in the range from the position 20 cm from the longitudinal end of the easy - adhesion PET film in the longitudinal direction of the easy - adhesion PET film to the position 30 cm from that position, laminate them to have the structure of glass plate / easy - adhesion PET film / interlayer film for laminated glass / thin - film PET film / glass plate. Then, perform vacuum pumping at an absolute pressure of 0.09 MPa for 5 minutes at room temperature. And then, heat up at a heating rate of 6 °C / min to 90 °C, and after reaching 90 °C, cool down to room temperature. Then, peel the glass plate that was in contact with the easy - adhesion PET film from the easy - adhesion PET film. After that, cut the laminated film of the easy - adhesion PET film and the interlayer film for laminated glass along the longitudinal direction of the easy - adhesion PET film so that the length in the width direction becomes 25 mm, and produce 12 samples for the peel test that have a width of 25 mm and are adhered to the glass. And for each sample, perform a 180° peel test to peel the sample from the glass plate along the longitudinal direction at a peel rate of 300 mm / min. At this time, take the average value of the adhesive force between displacements of 20 - 180 mm with the displacement at the point where the sample starts to peel from the glass plate set as 0 mm as the adhesive force of that sample.

[0014] In the preliminary adhesion test of the present invention, an ultra-thin film PET film is placed only on a part of the upper surface of one glass plate, and the adhesion surface between the intermediate film for laminated glass and one glass plate after preliminary adhesion can be peeled off by a 180° peel test, which can be said to correspond to the adhesion force between the glass plate and the intermediate film for laminated glass in preliminary adhesion. Therefore, when the average value of the above adhesion force is less than 20 N, in the case where a functional layer is provided, etc., the transparent substrate and the intermediate film for laminated glass are not sufficiently adhered by preliminary adhesion, and when laminated glass is manufactured by an autoclave process under low-temperature conditions, air may remain and the transmittance may decrease or the adhesion force may decrease. From such a viewpoint, the average value of the above adhesion force of the intermediate film for laminated glass of the present invention is preferably 23 N or more, more preferably 25 N or more. The upper limit value of the range of the average value of the above adhesion force of the intermediate film for laminated glass of the present invention is not particularly limited, but is usually 40 N.

[0015] The average value of the above adhesion force in the preliminary adhesion force test of the intermediate film for laminated glass can be adjusted, for example, by the type of resin contained in the thermoplastic resin layer (A), the embossing process on the surface, etc. It can also be adjusted by the amount, type, etc. of the plasticizer contained in the thermoplastic resin layer (A). Furthermore, when using a polyvinyl acetal resin, it can also be adjusted by the manufacturing conditions, etc. when manufacturing the polyvinyl acetal resin. Specifically, as described later, the average value of the above adhesion force in the preliminary adhesion force test of the intermediate film for laminated glass can be adjusted by the aging temperature in the aging process performed when manufacturing the polyvinyl acetal resin.

[0016] In the above preliminary adhesion test, when the displacement at the point where the sample starts to peel off from the glass is set to 0 mm, if the lower limit value of the adhesion force between 20 and 180 mm of displacement is taken as the lower limit value of the adhesion force of the sample, in the preliminary adhesion test of the interlayer film for laminated glass, the minimum value of the lower limit value of the adhesion force of all samples is preferably 12 N or more. When the minimum value of the lower limit value of the adhesion force in the preliminary adhesion test of the interlayer film for laminated glass is 13 N or more, it is possible to further suppress the decrease in transmittance and the decrease in adhesion force generated by the autoclave process under low-temperature conditions. From such a viewpoint, the minimum value of the lower limit value of the adhesion force of the interlayer film for laminated glass of the present invention is more preferably 14 N or more, and even more preferably 15 N or more. The range of the minimum value of the lower limit value of the adhesion force of the interlayer film for laminated glass of the present invention is not particularly limited, but is usually 25 N or less. The minimum value of the lower limit value of the adhesion force in the preliminary adhesion test of the interlayer film for laminated glass can be adjusted, for example, by the type of resin contained in the thermoplastic resin layer (A), the type of surface embossing process, etc. Further, it can also be adjusted by the amount and type of plasticizer contained in the thermoplastic resin layer (A). Furthermore, when using a polyvinyl acetal resin, it can also be adjusted by the manufacturing conditions when manufacturing the polyvinyl acetal resin. Specifically, as will be described later, the minimum value of the lower limit value of the adhesion force in the preliminary adhesion test of the interlayer film for laminated glass can be adjusted by the aging temperature in the aging process performed when manufacturing the polyvinyl acetal resin.

[0017] Examples of the thermoplastic resin (a) used in the thermoplastic resin layer (A) of the present invention include (meth)acrylic resins, polyvinyl acetal resins, polyvinyl alcohol resins (PVA), polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymers (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, styrene-butadiene copolymer resins, and the like. The thermoplastic resin may be used alone or in combination of two or more.

[0018] Among these, from the perspective of achieving both moisture and heat resistance and impact resistance, the thermoplastic resin (a) is preferably a polyvinyl acetal resin, a polyurethane resin (PU), an ethylene-vinyl acetate copolymer resin (EVA), a saponified ethylene-vinyl acetate copolymer (EVOH), an ethylene-methacrylic acid copolymer resin, an ionomer resin, an isobutylene resin, a styrene-isoprene copolymer resin, or a styrene-butadiene copolymer resin. Among these, the polyvinyl acetal resin is more preferable as the thermoplastic resin. By using the polyvinyl acetal resin, it is easier to obtain excellent impact resistance. Also, it is easier to achieve good adhesion to various resin materials and inorganic glass. Hereinafter, the polyvinyl acetal resin used for the thermoplastic resin (a) will be described in detail.

[0019] (Polyvinyl acetal resin) The polyvinyl acetal resin is not particularly limited as long as it is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The above aldehyde is not particularly limited, but generally, aldehydes having 1 to 10 carbon atoms are preferably used. The aldehydes having 1 to 10 carbon atoms are not particularly limited. For example, n-butyl aldehyde, isobutyl aldehyde, n-valeraldehyde, 2-ethylbutyl aldehyde, n-hexyl aldehyde, n-octyl aldehyde, n-nonyl aldehyde, n-decyl aldehyde, formaldehyde, acetaldehyde, benzaldehyde, etc. can be mentioned. These aldehydes may be used alone or in combination of two or more. Among the above, n-butyl aldehyde, n-hexyl aldehyde, and n-valeraldehyde are preferable, and n-butyl aldehyde is more preferable. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin.

[0020] Polyvinyl alcohol (PVA) can be obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The saponification degree of polyvinyl alcohol is generally 70 to 99.9 mol%. The average degree of polymerization of PVA is preferably 200 or more, more preferably 500 or more, still more preferably 750 or more, and even more preferably 1200 or more. When the average degree of polymerization is at least the above lower limit, the penetration resistance of the optical laminate becomes high when used in the optical laminate. Further, the average degree of polymerization of PVA is preferably 5000 or less, more preferably 3500 or less, still more preferably 3000 or less, and even more preferably 2000 or less. Incidentally, the average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Test Methods for Polyvinyl Alcohol". Further, when two or more kinds of polyvinyl alcohol are used as raw materials, the average degree of polymerization of polyvinyl alcohol can be estimated by calculation from the average degree of polymerization of each polyvinyl alcohol.

[0021] For the polyvinyl alcohol used as a raw material of the polyvinyl acetal resin, two or more kinds of polyvinyl alcohol having different average degrees of polymerization may be used. In this case, it is preferable to produce the polyvinyl acetal resin by the production method described later using a mixture of two or more kinds of polyvinyl alcohol as a raw material. When using two or more kinds of polyvinyl alcohol, for example, it is preferable to use a first polyvinyl alcohol having an average degree of polymerization of 1500 or more and a second polyvinyl alcohol having an average degree of polymerization of 1200 or less. 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, still more preferably 1600 or more and 2000 or less. Further, the average degree of polymerization of the second polyvinyl alcohol is preferably 200 or more and 1200 or less, more preferably 300 or more and 900 or less, still more preferably 400 or more and 850 or less. When using the first and second polyvinyl alcohols, the blending ratio of the first polyvinyl alcohol and the second polyvinyl alcohol is not particularly limited. However, the blending amount of the second polyvinyl alcohol with respect to the total amount of the first and second polyvinyl alcohols is preferably 1% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 40% by mass or less, still more preferably 5% by mass or more and 35% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less.

[0022] 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, the adhesiveness is likely to be good, and when used in an optical laminate, the penetration resistance of the optical laminate is likely to be good. Further, by setting the amount of hydroxyl groups to 38 mol% or less, flexibility can be easily ensured, and it is possible to prevent the optical laminate from becoming too hard. Further, by adjusting the amount of hydroxyl groups within the above range, the generation of bubbles due to use in a high-temperature environment can be further suppressed, and the high-temperature heat resistance of the interlayer film for laminated glass can be further improved. The above amount of hydroxyl groups is more preferably 20 mol% or more and even more preferably 25 mol% or more. Further, the above amount of hydroxyl groups is more preferably 35% or less and even more preferably 33 mol% or less. Even when using a polyvinyl butyral resin 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 a value obtained by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain and expressing the molar fraction as a percentage. The amount of ethylene groups to which the above hydroxyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Test Methods for Polyvinyl Butyral".

[0023] The degree of acetalization of the polyvinyl acetal resin is preferably 47 mol% or more, and preferably 85 mol% or less. More preferably, the degree of acetalization is 55 mol% or more, still more preferably 60 mol% or more, and more preferably 80 mol% or less, still more preferably 75 mol% or less. Note that when the acetal group is a butyral group and the polyvinyl acetal resin (A) is a polyvinyl butyral resin, the degree of acetalization means the degree of butyralization.

[0024] The above degree of acetalization is a value obtained by dividing, by the total amount of ethylene groups in the main chain, the value obtained by subtracting the amount of ethylene groups to which a hydroxyl group is bonded and the amount of ethylene groups to which an acetyl group is bonded from the total amount of ethylene groups in the main chain, and showing the mole fraction as a percentage. The degree of acetalization (degree of butyralization) may be calculated from the results measured by a method conforming to, for example, JIS K6728 "Test Methods for Polyvinyl Butyral".

[0025] The degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, and even more preferably 2 mol% or less. When the above degree of acetylation is below the above upper limit, the moisture resistance of the polymer film increases. The degree of acetylation is not particularly limited, but is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more. The above degree of acetylation is a value obtained by dividing the amount of ethylene groups to which an acetyl group is bonded by the total amount of ethylene groups in the main chain and showing the mole fraction as a percentage. The amount of ethylene groups to which the above acetyl group is bonded can be measured, for example, in accordance with JIS K6728 "Test Methods for Polyvinyl Butyral".

[0026] 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 other than an acetal group, a hydroxyl group, and an acetyl group (modified group), and preferably has the modified group in the side chain. Examples of the modified group include those having a polyalkylene oxide structure in the side chain and those having an alkyl group other than an acetal group and an acetyl group (for example, having about 2 to 30 carbon atoms) in the side chain. The modification amount is not particularly limited, but is, for example, about 0.1 mol% or more and about 10 mol%. The modification amount represents the ratio of the functional group to all vinyl monomer units constituting the polyvinyl acetal resin. In the thermoplastic resin layer (A), the polyvinyl acetal resin may be used alone or in combination of two or more.

[0027] When the polyvinyl acetal resin is used as the thermoplastic resin (a) in the thermoplastic resin layer (A), the thermoplastic resin layer (A) may contain a thermoplastic resin other than the polyvinyl acetal resin as long as the effects of the present invention are exhibited. The thermoplastic resin other than the polyvinyl acetal resin is as described above. However, in the thermoplastic resin layer (A), the polyvinyl acetal resin is preferably the main component. Specifically, the content of the polyvinyl acetal resin is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass based on the total amount of the thermoplastic resin (a) contained in the thermoplastic resin layer (A). Therefore, the thermoplastic resin (a) contained in the thermoplastic resin layer (A) of the present invention may consist only of the polyvinyl acetal resin.

[0028] (Method for producing polyvinyl acetal resin) The polyvinyl acetal resin is preferably produced by a production method including a mixing step of mixing the above polyvinyl alcohol and the above aldehyde, and an aging step of aging the mixture obtained in the mixing step.

[0029] In the mixing process, it is advisable to mix polyvinyl alcohol and aldehyde according to the conventional method. Additionally, a catalyst such as an acid catalyst for promoting the acetalization reaction may be further added in addition to polyvinyl alcohol and aldehyde. For example, aldehyde may be added to a mixture obtained by adding an acid catalyst to polyvinyl alcohol under low-temperature conditions of about 0 to 40°C. Further, when two or more types of polyvinyl alcohol are used in combination (for example, when using two or more types of polyvinyl alcohol with different molecular weights), it is advisable to mix two or more types of polyvinyl alcohol with aldehyde.

[0030] The aging process is not particularly limited. For example, a catalyst such as an acid catalyst may be added to the mixture (reaction mixture) obtained by the above mixing process, heated to the aging temperature, and held at the aging temperature for a certain period of time. In this manufacturing method, in the mixing process and the aging process, the acetalization of polyvinyl alcohol proceeds to obtain a polyvinyl acetal resin. After the reaction mixture is held at the above aging temperature for a certain period of time, it may be appropriately cooled and then neutralized, and thereafter, washed with water, dried, etc. as necessary.

[0031] Examples of the acid catalyst added in the above mixing process and aging process include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, boric acid, and sulfuric acid. Further, in the aging process, the concentration of the acid catalyst is preferably adjusted to a concentration of, for example, 0.5% by mass or more and 5% by mass or less, preferably 1% by mass or more and 2.5% by mass or less. The aging temperature in the aging process is preferably carried out at a relatively low temperature. For example, it is 40°C or higher and 60°C or lower, preferably 35°C or higher and 60°C or lower, more preferably 40°C or higher and 57°C or lower. Further, the time (aging time) held at the above aging temperature may be longer than a certain time. For example, it is 75 minutes or more and 180 minutes or less, preferably 90 minutes or more and 150 minutes or less, more preferably 100 minutes or more and 140 minutes or less.

[0032] When the post-curing temperature and the curing time are within the above-mentioned desired ranges, it is presumed that in the polyvinyl acetal resin, hydroxyl groups are likely to be uniformly distributed in the molecule, whereby it is considered that the low molecular weight components are reduced and the molecular weight distribution becomes smaller. As a result, the average value of the adhesive force in the above-mentioned preliminary adhesion test can be increased. Further, the low molecular weight components are reduced and the molecular weight distribution is likely to become smaller. The factor for the reduction of the low molecular weight components is not clear, but it is presumed that it is because the intermolecular crosslinking is promoted.

[0033] (Plasticizer) The thermoplastic resin layer (A) preferably contains a plasticizer. By containing a plasticizer, the thermoplastic resin layer (A) becomes flexible, and the adhesiveness of the thermoplastic resin layer (A) to various adherends and the penetration resistance and the like can be improved. Further, it becomes easy to increase the average value of the adhesive force in the above-mentioned preliminary adhesion test.

[0034] Examples of the plasticizer include organic ester plasticizers, organic phosphorus plasticizers such as organic phosphate plasticizers and organic phosphite plasticizers, organic ether plasticizers such as polyalkylene glycol plasticizers, and alcohol plasticizers. The plasticizer may be used alone or in combination of two or more. Among the above, organic ester plasticizers and organic ether plasticizers are preferable.

[0035] Preferable organic ester plasticizers include monobasic organic acid esters and polybasic organic acid esters. Examples of the monobasic organic acid ester include esters of glycol and monobasic organic acids. Examples of the glycol include polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the repeating number of the alkylene units is 2 to 10, preferably 2 to 4. Further, the glycol may be a monoalkylene glycol having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms (that is, the repeating unit is 1). 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, such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, n-octylic acid, 2-ethylhexanoic acid, n-nonanoic acid, and decylic acid.

[0036] Specific examples of monobasic organic acid esters include triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicapriate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, ethylene glycol di-2-ethylbutyrate, 1,2-propylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, and 1,2-butylene glycol di-2-ethylbutyrate.

[0037] 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, and alcohols having 4 to 10 carbon atoms. The alcohol having 4 to 10 carbon atoms may be linear, may have a branched structure, or may have a cyclic structure. Specifically, examples include dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, diisononyl adipate, heptyl nonyl adipate, dibutyl carbitol adipate, mixed adipic acid esters, etc. Also, oil-modified sebacic acid alkyds and the like may be used. Examples of the mixed adipic acid esters include adipic acid esters 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.

[0038] The organic ester plasticizer is not limited to the complete esters of the above-mentioned respective esters, and partial esters may also be used. For example, it may be a partial ester of a glycol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol. Specifically, examples include triethylene glycol-mono-2-ethylhexanoate. Furthermore, it may be a partial ester of a trivalent or higher alcohol such as glycerin and a monobasic organic acid. 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 trivalent or higher alcohol and a monobasic organic acid include mono- or diesters of glycerin and stearic acid, mono- or diesters of glycerin and 2-ethylhexanoic acid, and the like. Among the above, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferably used as the organic ester plasticizer.

[0039] Examples of the organic phosphorus plasticizer include phosphate esters such as tributoxyethyl phosphate, isodecyl phenyl phosphate, and triisopropyl phosphate. Examples of the polyalkylene glycol-based plasticizer include polyoxyalkylene-based compounds having a polyoxyalkylene structure. Specifically, polyhydric alcohol compounds such as glycols, ester compounds of glycols and monobasic or polybasic organic acids, ether compounds of monohydric or polyhydric alcohols and polyoxyalkylene, and the like can be mentioned. Here, examples of the glycol include polyoxyalkylene glycols and their derivatives. Examples of the polyoxyalkylene include polyoxyethylene, polyoxypropylene, polyoxybutylene, random copolymers or block copolymers thereof, and the like. The polyoxyalkylene-based compound may be a polyhydric alcohol compound, an ester compound, an ether compound, or other compounds as described above. Examples of the polyoxyalkylene-based compound include polyoxyalkylene or its derivatives. More specifically, polyoxyalkylene glycols composed of the above polyoxyalkylene, ether compounds of polyoxyalkylene and polyhydric alcohols, and the like can be mentioned. All of these may have hydroxyl groups at all terminals, or some or all of the terminal hydroxyl groups may be derivatives in which a hydrogen atom is substituted with an alkyl group or an acyl group. The number of carbon atoms of the alkyl group and the acyl group is not particularly limited, but is preferably about 1 to 8, and more preferably 1 to 4. Examples of the polyoxyalkylene glycol include polyoxyethylene polyoxypropylene glycols such as polyethylene glycol (polyoxyethylene glycol), polypropylene glycol (polyoxypropylene glycol), poly(ethylene oxide / propylene oxide) block copolymer, poly(ethylene oxide / propylene oxide) random copolymer, and polyoxybutylene glycols such as polytetramethylene glycol. Examples of the ether compound of polyoxyalkylene and polyhydric alcohol include ether compounds of polyhydric alcohols such as glycerol, diglycerol, trimethylolpropane, erythritol, pentaerythritol, bisphenol A, and polyoxyalkylene. Specifically, polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, and the like can be mentioned. Further, examples of the derivative in which part or all of the hydrogen atoms of the terminal hydroxyl group are substituted with an alkyl group or an acyl group include the above-mentioned polyoxyalkylene glycols and derivatives in which part or all of the hydrogen atoms of the terminal hydroxyl group of the ether compound are substituted with an alkyl group or an acyl group. Specifically, polyoxyethylene glycol monomethyl ether, polyoxyethylene glycol dimethyl ether, polyoxypropylene glycol monomethyl ether, polyoxypropylene glycol dimethyl ether, polyoxyethylene polyoxypropylene glycol monomethyl ether, polyoxyethylene polyoxypropylene glycol dimethyl ether, polyoxyethylene glycol monobutyl ether, polyoxypropylene glycol monobutyl ether, polyoxyethylene polyoxypropylene monobutyl ether, and the like can be mentioned. Among the above, polyoxyalkylene compounds preferably have a polyoxyethylene, polyoxypropylene, or polyoxyethylene polyoxypropylene structure, and among them, those having a polyoxypropylene or polyoxyethylene polyoxypropylene structure are more preferred. Specifically, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or a derivative in which part of the hydrogen atoms of their terminal hydroxyl groups are substituted with an alkyl group is preferred. Examples of the alcohol plasticizer include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, and pentaerythritol. Among these, trimethylolpropane is preferred. Examples of the alcohol plasticizer include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, and pentaerythritol. Among these, trimethylolpropane is preferred.

[0040] The above plasticizers can be used alone or in combination of two or more. Among the above plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO), polyoxypropylene diglyceryl ether (DGP), and polypropylene glycol (PPG) are preferred, and triethylene glycol-di-2-ethylhexanoate (3GO) is more preferred.

[0041] The content of the plasticizer in the thermoplastic resin layer (A) is not particularly limited, but is preferably 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin (a). When the content of the plasticizer is 10 parts by mass or more, the thermoplastic resin layer (A) becomes moderately flexible, and the adhesiveness of the thermoplastic resin layer (A) and the penetration resistance of the optical laminate are good. Furthermore, it becomes easy to increase the average value of the adhesive force in the above preliminary adhesion test. On the other hand, when the content of the plasticizer is 100 parts by mass or less, separation of the plasticizer from the thermoplastic resin layer (A) is prevented. The above content of the plasticizer is more preferably 15 parts by mass or more, still more preferably 30 parts by mass or more, even more preferably 35 parts by mass or more, and also more preferably 70 parts by mass or less, still more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less.

[0042] When the thermoplastic resin layer (A) contains a polyvinyl acetal resin, the content of the plasticizer in the thermoplastic resin layer (A) is preferably 30 parts by mass or more and 50 parts by mass or less among the above with respect to 100 parts by mass of the polyvinyl acetal resin. When the content of the plasticizer is 30 parts by mass or more, the thermoplastic resin layer (A) becomes moderately flexible, and the adhesiveness of the thermoplastic resin layer (A) and the penetration resistance of the optical laminate are good. Furthermore, it also becomes easy to increase the average value of the adhesive force in the above preliminary adhesion test. On the other hand, when the content of the plasticizer is 50 parts by mass or less, separation of the plasticizer from the thermoplastic resin layer (A) is prevented. The content of the plasticizer is more preferably 35 parts by mass or more, more preferably 45 parts by mass or less, and even more preferably 42 parts by mass or less.

[0043] In addition to the plasticizer, the thermoplastic resin layer (A) may appropriately contain known additives used in combination with the thermoplastic resin (a). That is, the thermoplastic resin layer (A) may be composed of a thermoplastic resin (a) such as a polyvinyl acetal resin, or a thermoplastic resin (a) and a plasticizer, but may also contain additives other than the plasticizer compounded as needed. Specific examples of the additives other than the plasticizer include ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, adhesion adjusters, colorants, fluorescent brighteners, crystal nucleating agents, and the like.

[0044] The thermoplastic resin layer (A) may contain a colorant as described above. By using the colorant, the interlayer film for laminated glass can be satisfactorily colored in a desired color tone. Only one kind of the colorant may be used, or two or more kinds may be used in combination. The thermoplastic resin layer (A) may contain only one kind of the colorant, or may contain two or more kinds.

[0045] Examples of the colorant include pigments and dyes. The colorant may be a pigment, a dye, or both a pigment and a dye. Note that there are also colorants classified as both a pigment and a dye.

[0046] Pigment: The above coloring agent may contain a pigment or may be a pigment. The above thermoplastic resin layer (A) may or may not contain a pigment. As for the above pigment, only one kind may be used, two or more kinds may be used in combination, three or more kinds may be contained, ten or less kinds may be contained, and five or less kinds may be contained. The above thermoplastic resin layer (A) may contain only one kind of pigment, two or more kinds of pigments, three or more kinds of pigments, ten or less kinds of pigments, and five or less kinds of pigments.

[0047] Examples of the above pigment include perylene compounds, threne compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, perinone compounds, phthalocyanine compounds, indanthrene compounds, indigo compounds, isoindolinone compounds, nickel complex compounds, methine compounds, azomethine compounds, dioxazine, azo compounds, and carbon black.

[0048] When the above thermoplastic resin layer (A) contains a pigment, the content of the above pigment in 100% by mass of the above thermoplastic resin layer (A) is preferably 0.0001% by mass or more, more preferably 0.01% by mass or more, still more preferably 0.02% by mass or more, preferably 0.15% by mass or less, and more preferably 0.12% by mass or less.

[0049] Dye: The above coloring agent may contain a dye or may be a dye. The above thermoplastic resin layer (A) may or may not contain a dye. As for the above dye, only one kind may be used, two or more kinds may be used in combination, three or more kinds may be contained, ten or less kinds may be contained, and five or less kinds may be contained.

[0050] Examples of the above dye include perylene compounds, threne compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, perinone compounds, phthalocyanine compounds, indanthrene compounds, indigo compounds, isoindolinone compounds, nickel complex compounds, methine compounds, azomethine compounds, dioxazine, and azo compounds.

[0051] When the above-mentioned thermoplastic resin layer (A) contains a dye, the content of the dye in 100% by mass of the above-mentioned thermoplastic resin layer (A) is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, still more preferably 0.001% by mass or more, preferably less than 0.015% by mass, and more preferably 0.01% by mass or less.

[0052] When the above-mentioned thermoplastic resin layer (A) contains a colorant, the content of the colorant in 100% by mass of the above-mentioned thermoplastic resin layer (A) is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, still more preferably 0.001% by mass or more, preferably 0.15% by mass or less, and more preferably 0.12% by mass or less.

[0053] As described above, the interlayer film for laminated glass of the present invention has a single-layer structure or a multi-layer structure. When the interlayer film for laminated glass of the present invention has a multi-layer structure, some of the layers may be the thermoplastic resin layer (A), or all of the layers may be the thermoplastic resin layer (A). Further, in the case of a multi-layer structure, any one of the outermost layers may be the thermoplastic resin layer (A), but it is preferable that both outermost layers are the thermoplastic resin layer (A). When both outer layers are the thermoplastic resin layer (A), it becomes easier to further suppress the residual air and the foaming of the peripheral portion when pressing against a transparent substrate or the like. On the other hand, in the case of a single-layer structure, the interlayer film for laminated glass may preferably consist of the single-layer of the above-mentioned thermoplastic resin layer (A).

[0054] For the interlayer film for laminated glass, for example, in the case of a two-layer structure, either one may be the thermoplastic resin layer (A), but it is preferable that both are the thermoplastic resin layer (A). Further, when the interlayer film for laminated glass has a three-layer structure having two outermost layers and a middle layer, either one of the two outermost layers may be the thermoplastic resin layer (A), but it is preferable that both outermost layers are the thermoplastic resin layer (A). In this case, the middle layer may be composed of the thermoplastic resin layer (A), or may be composed of other than the thermoplastic resin layer (A). In addition, the interlayer film for laminated glass may have two outermost layers and two or more intermediate layers, and may have a structure of four or more layers. In this case, either one of the two outermost layers may be the thermoplastic resin layer (A), but it is preferable that both are the thermoplastic resin layer (A). Also, each intermediate layer may be composed of the thermoplastic resin layer (A), or may be composed of other than the thermoplastic resin layer (A). Also, when the interlayer film for laminated glass of the present invention has a plurality of layers of the thermoplastic resin layer (A), the thermoplastic resin layers (A) may have the same configuration or different configurations. For example, in a plurality of thermoplastic resin layers (A), the types of the thermoplastic resins constituting them and their contents may be the same as each other or different from each other. Also, when the interlayer film for laminated glass has a layer other than the thermoplastic resin layer (A), such a layer may be, for example, a resin layer other than the thermoplastic resin layer.

[0055] In the interlayer film for laminated glass, the thickness of the thermoplastic resin layer (A) is not particularly limited, but it is preferable that it occupies a certain ratio or more of the total thickness of the interlayer film for laminated glass. Specifically, the thickness of the thermoplastic resin layer (A) may be, for example, a ratio of 0.1 or more and 1 or less, preferably 0.3 or more and 1 or less, more preferably 0.5 or more and 1 or less, and even more preferably 0.75 or more and 1 or less, with respect to the total thickness of the interlayer film for laminated glass. Here, the thickness of the thermoplastic resin layer (A) means the total thickness when there are two or more layers of the thermoplastic resin layer (A). By containing the thermoplastic resin layer (A) in a certain thickness ratio or more in the interlayer film for laminated glass, it becomes easier to suppress the remaining air during crimping and foaming at the peripheral portion.

[0056] The thickness of each specific thermoplastic resin layer (A) is not particularly limited, but is, for example, 10 μm or more and 2000 μm or less, preferably 20 μm or more and 1000 μm or less, and more preferably 30 μm or more and 900 μm or less. By having a certain thickness or more, the thermoplastic resin layer (A) becomes easier to suppress the remaining air during crimping. Also, by setting the thickness to a certain value or less, it is possible to prevent the interlayer film for laminated glass from becoming thicker than necessary.

[0057] The interlayer film for laminated glass of the present invention preferably has an uneven shape on one or both surfaces. In this case, in the interlayer film for laminated glass of the present invention, it is preferable that the concave portion of the unevenness on at least one of the above surfaces has a groove shape with a continuous bottom to form a notch-shaped concave portion. When pre-bonding is performed by rubber backing, the end portion is temporarily bonded first, and the air near the center may be difficult to escape. However, by forming a notch-shaped concave portion, the air near the center can also easily escape, and the adhesiveness during pre-bonding is improved. More preferably, a plurality of notch-shaped concave portions are arranged in parallel, and among them, it is even more preferable that the adjacent concave portions are regularly arranged in parallel. Generally, the ease of air escape when pressing a laminate in which an interlayer film for laminated glass is laminated between two glass plates is closely related to the connectivity and smoothness of the bottom of the above concave portion. By forming the uneven shape on at least one surface of the interlayer film into a shape in which notch-shaped concave portions are regularly arranged in parallel, the connectivity of the above bottom is excellent and the degassing property is further improved. In addition, the notch-shaped concave portions regularly arranged in parallel may have the adjacent notch-shaped concave portions arranged in parallel at equal intervals, but it is not necessary for the intervals between all the adjacent notch-shaped concave portions to be equal. Further, the concave portions on the above notch do not necessarily have a continuous groove shape at the bottom, and may have a dividing wall in a part of the bottom. Further, if the adjacent concave portions are regularly arranged in parallel, the shape of the groove at the bottom does not have to be linear, and may be, for example, wavy or zigzag.

[0058] When the interlayer film for laminated glass of the present invention has an uneven shape on the surface, the surface roughness (R zjis94 ) is preferably 10 to 80 μm. When the surface roughness (R zjis94 ) of the surface having the uneven shape of the interlayer film for laminated glass is 10 to 80 μm, excellent degassing properties can be exhibited. From such a viewpoint, the surface roughness (R zjis94 ) of the surface having the uneven shape of the interlayer film for laminated glass of the present invention is more preferably 20 to 65 μm, and even more preferably 20 to 50 μm. In addition, in this specification, the surface roughness (R zjis94) can be measured in accordance with JIS B-0601 (1994). When the uneven shape on the surface is in the form of engraved lines, it can be obtained by measuring in the vertical direction so as to cross the direction in which the concave portions in the engraved line direction are continuous. Here, as the measuring instrument, for example, "Surfcorder SE300" manufactured by Kosaka Laboratory Ltd. can be used. The cut-off value during measurement is 2.5 mm, the reference length is 2.5 mm, the measuring length is 12.5 mm, the preliminary length is 2.5 mm, the feed rate of the palpation needle is 0.5 mm / second, and the measurement can be carried out under the condition of using a probe shape with a tip radius of 2 μm and a tip angle of 60°. Also, the environment during measurement is 23°C and 30% RH. The intermediate film to be measured is measured after being left standing for 3 hours or more under the measurement environment.

[0059] The manufacturing method of the intermediate film for laminated glass is not particularly limited and may be manufactured by a conventionally known method, for example, by extrusion molding, press molding, etc., but it is preferably manufactured by extrusion molding. Also, as a method of forming a large number of concave portions and a large number of convex portions on at least one surface of the intermediate film for laminated glass, for example, an embossing roll method, a calendar roll method, a profile extrusion method, a melt fracture method, etc. can be mentioned. Among them, the embossing roll method is preferable.

[0060] [Laminated body] The laminated body of the present invention includes the intermediate film for laminated glass of the present invention and a functional layer different from the intermediate film for laminated glass of the present invention. By having the above-mentioned intermediate film for laminated glass, when the functional layer is incorporated into an optical laminated body or the like, pressure bonding by an autoclave at a low temperature can be utilized, so that it is possible to suppress the functional layer from being deactivated. In the laminated body of the present invention, the functional layer is preferably disposed between a pair of the intermediate films for laminated glass of the present invention. However, the functional layer may be disposed between the intermediate film for laminated glass of the present invention and an intermediate film for laminated glass other than the above-mentioned intermediate film for laminated glass of the present invention. Also, the layer structure of the laminated body is not limited to the structure in which the functional layer is disposed between a pair of intermediate films for laminated glass, and can take various forms as described later.

[0061] [Functional layer] In the laminate of the present invention, the functional layer to be used is not particularly limited as long as it is a layer having a predetermined function. As the functional layer used in the laminate of the present invention, for example, a functional film can be used. The functional film may be a dimming film, a display element film, or an optical film such as a polarizing film, a retardation film, an antireflection film, or the like. Further, a solar cell element can also be used as the functional layer.

[0062] Further, among the above, the functional film is preferably a film provided with electronic components such as a dimming film and a display element film. When an autoclave under high temperature and high pressure conditions is applied to a film provided with electronic components, its function is likely to deteriorate or deactivate. However, according to the present invention, it can be pressure-bonded by an autoclave at a low temperature, so that a functional layer such as an optical laminate can be incorporated without deactivating the functional layer. Therefore, even a film provided with electronic components can be incorporated into the laminate so that it can be used practically. Further, when an optical laminate having any of these is incorporated into various window glasses, a window glass with high added value can be provided. Therefore, in the present invention, it is desirable to use any of these functional films as the functional layer.

[0063] The dimming film is a film-shaped member having a dimming element. Specifically, the dimming element is preferably a dimming film including two resin films and a dimming layer disposed between the two resin films. Therefore, the adhesion surface of the dimming film to the thermoplastic resin layer becomes a resin material, and the adhesion strength to the thermoplastic resin layer (A) is likely to increase. The resin film used for the dimming element is not particularly limited, and examples include polyester resin films such as PET film and PEN film, (meth)acrylic resin film, TAC film, PES resin film, and polyimide resin film. Among these, from the viewpoint of handleability and the like, a polyester resin film is preferable, and among them, a PET film is more preferable. Further, a conductive layer constituting an electrode is provided on the surface on the dimming layer side of each of the two resin films.

[0064] The dimming layer is one in which the visible light transmittance changes by switching the application and non-application of voltage between the conductive layers of the two resin films. The dimming layer is composed of a liquid crystal layer such as a polymer dispersed liquid crystal (PDLC), and the dimming film may be a PDLC film. Further, the dimming film may be an SPD (Suspended Particle Device) film, an electrochromic film, an electrophoretic film device, or the like. Therefore, the dimming layer may be an SPD layer including a resin matrix and a light adjustment suspension dispersed in the resin matrix, or may be an electrochromic material layer. Further, it may be an electrophoretic layer including electrophoretic particles and a dispersant for dispersing the electrophoretic particles.

[0065] The display element film is a film-like member provided with a display element. Examples of the display element film include those comprising a resin film and a display element mounted on the resin film. The display element film may be composed of a pair of resin films with a display element provided therebetween. With such a configuration, when disposed between a pair of intermediate films for laminated glass and incorporated into an optical laminate, it can be adhered to the intermediate film for laminated glass with high adhesiveness. Note that as the resin film used for the display element film, the resin films listed in the light control film can be appropriately selected and used. Also, in the display element film, the resin film may be provided with a conductive layer that constitutes an electrode on the surface on the display element side. Examples of the display element include an organic EL element, an LED display, a segment display, etc., among which an organic EL element is preferable.

[0066] Note that the functional film having an electronic component is not limited to the above-described display element film and light control film, and may be other functional films. However, the electronic component may be mounted on a resin film in the same manner as the display element film and the light control film, but an aspect in which the electronic component is disposed between a pair of resin films is preferable.

[0067] By using a solar cell element in the functional layer, it is possible to provide laminated glass for building-integrated photovoltaics (BIPV). The solar cell element is not particularly limited, and any solar cell element used for building-integrated power generation equipment (BIPV) may be used. Examples thereof include crystalline or thin-film silicon-based solar cell elements; compound semiconductor-based solar cell elements such as CIS, CIGS, CdTe, and GaAs; and organic solar cell elements such as dye-sensitized, organic thin-film, and perovskite solar cell elements.

[0068] The laminate can be manufactured, for example, by thermocompression bonding a functional layer and an interlayer film for laminated glass. Also, when incorporating the laminate into an optical laminate, in thermocompression bonding, after previously thermocompression bonding the functional layer and the interlayer film for laminated glass to form a laminate, the laminate may be pressure bonded to a transparent substrate to form an optical laminate. Further, in the step of disposing the functional layer before pressure bonding and the interlayer film for laminated glass between the transparent substrates and pressure bonding the transparent substrate and the interlayer film for laminated glass, the functional layer and the interlayer film may be pressure bonded together.

[0069] [Optical laminate] The optical laminate of the present invention includes a first transparent substrate, a second transparent substrate, and the interlayer film for laminated glass of the present invention or the laminate of the present invention disposed between the first and second transparent substrates.

[0070] [First and second transparent substrates] Examples of the first and second transparent substrates used in the optical laminate of the present invention include glass plates. The glass plate may be either inorganic glass or organic glass, but inorganic glass is preferred. The inorganic glass is not particularly limited, and examples include clear glass, float plate glass, tempered glass, colored glass, polished plate glass, patterned plate glass, wired glass, lined plate glass, ultraviolet absorbing plate glass, infrared reflecting plate glass, infrared absorbing plate glass, green glass, etc. Also, as the organic glass, what is generally called resin glass is used, and various organic glass plates such as polycarbonate plates, (meth)acrylic plates such as polymethyl methacrylate plates, acrylonitrile styrene copolymer plates, acrylonitrile butadiene styrene copolymer plates, polyester plates such as polyethylene terephthalate plates, fluororesin 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. can be mentioned. The organic resin plate may be appropriately surface treated or the like.

[0071] The first and second transparent substrates may be made of the same type of material as each other, or may be made of different materials. For example, one may be inorganic glass and the other may be organic glass, but it is preferable that both the first and second transparent substrates are inorganic glass or organic glass. Also, the thickness of each glass plate used as the first and second transparent substrates is not particularly limited, but for example, it is about 0.1 to 15 mm, preferably 0.5 to 5 mm. The thicknesses of the respective glass plates may be the same as each other or different from each other.

[0072] The transparent substrate may be composed of a single glass plate, or may be a glass plate to which other members are attached. It is preferable that a functional member is attached to the glass plate to impart various functions. The other members may be, for example, members that constitute electronic devices, optical members, etc., but are preferably members that constitute a display device. Examples of the display device may include a liquid crystal display device, an organic EL display device, an LED display device, a segment display device, etc. Among these, a liquid crystal display device is preferable as the display device.

[0073] The display device may be, for example, a display panel in which a glass plate is used as a substrate and a display layer such as a liquid crystal layer or an organic EL layer, a light-emitting element, etc. are provided on the substrate, but it is preferable to use the glass plate that serves as the substrate of the display panel as the transparent substrate. Also, a functional film, a conductive layer that constitutes an electrode, a sensor, etc., an antireflection layer, a hard coat layer, etc. may be laminated on the glass plate, but the transparent substrate may be a glass plate on which such a functional film or functional layer is laminated. Therefore, the bonding surface with the interlayer film for laminated glass, on which the interlayer film for laminated glass is directly laminated, may be the glass plate itself, or may be the surface of a functional film or functional layer.

[0074] When two or more interlayer films for laminated glass are provided in the laminate, it is preferable that all the interlayer films for laminated glass are the interlayer films for laminated glass of the present invention as described above, but some of the interlayer films for laminated glass may be other than the interlayer films for laminated glass of the present invention. Further, another layer such as an adhesive layer may be appropriately provided between the functional layer and the interlayer film for laminated glass.

[0075] [Layer structure of optical laminate] Next, with reference to the drawings, the layer structure of the optical laminate will be described in detail with reference to the embodiments. As shown in FIG. 1, in the first embodiment of the present invention, the optical laminate is an optical laminate 1A in which one interlayer film for laminated glass (thermoplastic resin layer (A)) 10 is provided between first and second transparent substrates 20 and 30. In the optical laminate 1A, the interlayer film for laminated glass 10 is adhered to both the first and second transparent substrates 20 and 30 to join them.

[0076] In the first embodiment, at least one of the first and second transparent substrates 20 and 30 is preferably one to which other members are attached as described above. Specifically, functional members constituting electronic devices such as display devices and optical members may be attached, or those laminated with the above-described functional films, functional layers, etc. may be used. Among them, it is preferable that at least one of the first and second transparent substrates 20 and 30 has a member constituting a display device, particularly a liquid crystal display device, attached thereto. That is, at least one of the first and second transparent substrates 20 and 30 is preferably a glass plate constituting a display device, and a display device having at least one of the first and second transparent substrates 20 and 30 as a substrate is preferably provided in the optical laminate 1A.

[0077] In the first embodiment, by using the above-described one including the thermoplastic resin layer (A) as the interlayer film 10 for laminated glass, even when the first and second transparent substrates 20 and 30 and the interlayer film 10 for laminated glass are integrated by an autoclave process under low-temperature conditions, foaming caused by residual air during crimping or use in a high-temperature environment can be suppressed. On the other hand, even if a functional member is provided on either one of the first and second transparent substrates 20 and 30, it can be crimped and integrated by an autoclave at low temperature, so that the functional member attached to the optical laminate 1A can be prevented from deteriorating or deactivating.

[0078] Further, as another preferred embodiment, the optical laminate may be one in which an interlayer film for laminated glass composed of a plurality of thermoplastic resin layers is provided between the first and second transparent substrates. When the interlayer film for laminated glass is composed of a plurality of thermoplastic resin layers, each thermoplastic resin layer is preferably the interlayer film for laminated glass of the present invention having the thermoplastic resin layer (A) described above. When a plurality of thermoplastic resin layers are provided, by making any of the thermoplastic resin layers the above-described thermoplastic resin layer (A), even when the first and second transparent substrates and the interlayer film for laminated glass are integrated in an autoclave process under low-temperature conditions, foaming caused by residual air during crimping or use in a high-temperature environment can be suppressed.

[0079] An embodiment of the optical laminate when a plurality of thermoplastic resin layers are provided is shown in FIG. 2 as the second embodiment. As shown in FIG. 2, in the optical laminate 1B according to the second embodiment, a pair of interlayer films 10 for laminated glass are provided between the first and second transparent substrates 20 and 30, and a functional layer 40 is further provided between the pair of interlayer films 10 for laminated glass. That is, in the optical laminate 1B according to the second embodiment, a laminate 50 in which a functional layer 40 is provided between a pair of thermoplastic resin layers 10 is provided between the first and second transparent substrates 20 and 30. Both of the pair of interlayer films 10 for laminated glass are the above-described thermoplastic resin layer (A). In the optical laminate 1B, one of the interlayer films 10 for laminated glass is adhered to both the first transparent substrate 20 and the functional layer 40 to join them, and the other thermoplastic resin layer 10 is adhered to both the second transparent substrate 30 and the functional layer 40 to join them. Thereby, the first and second transparent substrates 20 and 30 are integrated with the functional layer 40 by the interlayer film 10 for laminated glass, which is a thermoplastic resin layer (A).

[0080] Also in the second embodiment, the optical laminate 1B can press-bond the interlayer film 10 for laminated glass by an autoclave at a low temperature by using the interlayer film 10 for laminated glass having the thermoplastic resin layer (A), and can suppress foaming caused by residual air during press-bonding or use in a high-temperature environment. Further, since the optical laminate 1B is integrated at a low temperature, it is possible to prevent the functional layer 40 from deteriorating or deactivating.

[0081] In the second embodiment, a mode is shown in which two interlayer films 10 for laminated glass are provided in the laminate and one functional layer 40 is provided, but three or more interlayer films for laminated glass may be provided in the laminate and two or more functional layers may be provided. In this case, in the first and second optical laminates, the interlayer film for laminated glass and the functional layer may be alternately arranged. And an interlayer film for laminated glass may be arranged at the position closest to the first and second transparent substrates. For example, when three interlayer films 10 for laminated glass are provided and two functional layers are provided, they may be arranged in the order of the first transparent substrate / interlayer film for laminated glass / functional layer / interlayer film for laminated glass / functional layer / interlayer film for laminated glass / second transparent substrate. Also, when three or more interlayer films for laminated glass are provided, the above-described thermoplastic resin layer (A) may be used as each interlayer film for laminated glass. In the optical laminate, when a plurality of interlayer films for laminated glass are provided, the configurations of the respective interlayer films for laminated glass may be the same or different.

[0082] <Method for manufacturing an optical laminate> The optical laminate of the present invention is preferably manufactured by a manufacturing method in which at least an interlayer film or laminate for laminated glass is disposed between a first transparent substrate and a second transparent substrate, and these are bonded together by pressure bonding. Further, members constituting the laminate may be prepared, and the members constituting the laminate may be disposed between the first transparent substrate and the second transparent substrate, and these may be bonded together by pressure bonding to produce an optical laminate incorporating the laminate.

[0083] In the above manufacturing method, first, the first and second transparent substrates and members (an interlayer film for laminated glass or a laminate) disposed between the first and second transparent substrates are prepared. Here, the laminate disposed between the first and second transparent substrates may be appropriately selected according to the structure of the resulting optical laminate. For example, in the first embodiment, a single interlayer film for laminated glass may be prepared. Further, for example, in the second embodiment, a laminate composed of two interlayer films for laminated glass and one functional layer may be prepared.

[0084] Also, as described above, in the optical laminate, a functional member may be attached to at least one of the first and second transparent substrates, but the functional member is preferably attached to the transparent substrate before being integrated into the optical laminate. Therefore, in the above manufacturing method, at least one of the first and second transparent substrates may be prepared as a transparent substrate to which a functional member is attached. For example, as described above, when the transparent substrate constitutes a substrate of a display device, at least one of the first and second transparent substrates may be prepared as a display device.

[0085] In this manufacturing method, as described above, an interlayer film for laminated glass or a laminate is disposed between the first transparent substrate and the second transparent substrate, and these are bonded together to be integrated to obtain an optical laminate. Further, members constituting the laminate may be disposed between the first transparent substrate and the second transparent substrate, and these may be bonded together to be integrated to obtain an optical laminate incorporating the laminate. Here, the interlayer film for laminated glass or the laminate may be arranged according to the layer structure of the resulting optical laminate. For example, in the second embodiment, the interlayer film for laminated glass, the functional layer, and the interlayer film for laminated glass may be arranged between the first and second transparent substrates in this order.

[0086] The above lamination may be performed by an autoclave.

[0087] In this manufacturing method, it is necessary to perform the above lamination under low-temperature conditions. Specifically, it is preferably pressure-bonded at a temperature of 110°C or lower. Further, the above lamination is preferably performed at low temperature and low pressure. Specifically, it is preferably pressure-bonded at a temperature of 110°C or lower and a pressure of 1.0 MPa or lower. By performing the lamination under low-temperature and low-pressure conditions in this way, it is possible to prevent the functional layer and the functional members (for example, display devices) attached to the first and second transparent substrates from deteriorating or deactivating.

[0088] From the viewpoint of more surely preventing the deterioration or deactivation of the functional members, the temperature during lamination is preferably 110°C or lower. From the viewpoint of preventing the generation of residual air and foaming, it is preferably 60°C or higher, more preferably 70°C or higher. Also, from the viewpoint of more surely preventing the deterioration or deactivation of the functional members, the pressure during lamination is preferably 1.2 MPa or lower. Regarding the lower limit value of the pressure during lamination, there is no particular limitation. However, for example, when performing under pressure such as in an autoclave, it is preferably 0.5 MPa or higher, more preferably 0.7 MPa or higher. Also, when performing under negative pressure such as when using a vacuum back, it is preferably 0.01 MPa or higher, more preferably 0.05 MPa or higher. Also, the time for performing the lamination at the above temperature and pressure is not particularly limited, but for example, it is 1 to 120 minutes, preferably 5 to 60 minutes.

[0089] In this manufacturing method, it is preferable to perform preliminary adhesion before the above-mentioned lamination. This can further suppress the decrease in transmittance and the decrease in adhesive strength caused by the autoclave process under low-temperature conditions. The preliminary adhesion may be performed by a vacuum bag, by an autoclave under low-temperature conditions, or by a press machine other than these. Among these, it is preferable to perform it by a vacuum bag. Generally, it is advisable to use a rubber bag for the vacuum bag.

[0090] In this manufacturing method, it is also necessary to perform the above-mentioned preliminary adhesion under low-temperature conditions. Specifically, it is advisable to perform pressure bonding at a temperature of 110°C or lower. Further, the above-mentioned lamination is preferably performed at low temperature and low pressure. Specifically, it is preferable to perform pressure bonding at a temperature of 110°C or lower and a pressure of 0.1 MPa or lower. In this way, by performing preliminary adhesion under low-temperature and low-pressure conditions, it is possible to prevent the functional layer and the functional members (for example, display devices) attached to the first and second transparent substrates from deteriorating or deactivating.

[0091] From the viewpoint of more reliably preventing the deterioration and deactivation of the functional members, the temperature during the preliminary adhesion is preferably 100°C or lower. From the viewpoint of preventing the generation of residual air and foaming, it is preferably 60°C or higher, more preferably 70°C or higher. Further, from the viewpoint of more reliably preventing the deterioration and deactivation of the functional members, the pressure during the preliminary adhesion is preferably 1.2 MPa or lower. When performing under negative pressure as in the case of using a vacuum bag, for example, 0.1 MPa or lower is sufficient, preferably 0.095 MPa or lower, and more preferably 0.09 MPa or lower. Regarding the lower limit value of the pressure during the preliminary adhesion, there is no particular limitation. However, for example, when performing under pressure such as in an autoclave, it is preferably 0.5 MPa or higher, more preferably 0.7 MPa or higher. When performing under negative pressure as in the case of using a vacuum bag, it is preferably 0.001 MPa or higher, more preferably 0.005 MPa or higher. In addition, the time for performing the bonding at the above temperature and pressure is not particularly limited, but for example, it is 0 second to 15 minutes, preferably 0 to 7 minutes.

[0092] The optical laminate of the present invention is not particularly limited and can be used for various applications, but can be preferably used as laminated glass. The optical laminate of the present invention can be used for various vehicles such as automobiles, trains, ships, airplanes, or various buildings such as buildings, condominiums, single-family houses, halls, stadiums, or machine tools such as cutting and grinding machines, construction machines such as shovels and cranes, etc. for window glass, and partitions inside various vehicles and various buildings. Among them, vehicle applications such as automobiles and building applications are preferred, and it is preferably used for vehicle window glass and building integrated power generation equipment (BIPV). In addition, when the optical laminate of the present invention constitutes a display device with a transparent substrate, for example, it may be used for various display applications. As display applications, the above-described window glass and partitions may be used as displays. Also, the optical laminate may be used as a cover glass for various displays, and may be applied to, for example, in-vehicle displays.

Examples

[0093] The present invention will be described in more detail with reference to examples, but the present invention is not limited by these examples. The measurement methods and evaluation methods for each physical property value in the present invention are as follows.

[0094] <Preliminary Adhesion Test> Two glass plates 110 and 120, an easily adhesive PET film 130 having easy adhesiveness on one side, an ultra-thin film PET film 140, and an interlayer film 150 for laminated glass were prepared. As shown in FIG. 3, the two glass plates 110 and 120, the easily adhesive PET film 130, the ultra-thin film PET film 140, and the interlayer film 150 for laminated glass were laminated to produce a laminate 100A. As shown in FIG. 3, in the range up to the position at a distance of 20 cm from the end 131 in the longitudinal direction (y direction), the two glass plates 110 and 120, the easily adhesive PET film 130, the ultra-thin film PET film 140, and the interlayer film 150 for laminated glass were laminated so as to have a structure of glass plate 110 / easily adhesive PET film 130 / interlayer film 150 for laminated glass / glass plate 120. Further, as shown in FIG. 3, in the range of the position from the position at a distance of 20 cm from the end 131 in the longitudinal direction (y direction) to the position at a distance of 30 cm, the two glass plates 110 and 120, the easily adhesive PET film 130, the ultra-thin film PET film 140, and the interlayer film 150 for laminated glass were laminated so as to have a structure of glass plate 110 / easily adhesive PET film 130 / interlayer film 150 for laminated glass / ultra-thin film PET film 140 / glass plate 120. In this way, the thermoplastic resin layer (A) side of the interlayer film 150 for laminated glass was arranged on the glass plate 120 side, a part of the thermoplastic resin layer (A) was brought into contact with the glass plate 120 (for 20 cm in the y direction), and the rest (for 10 cm in the y direction) was brought into contact with the ultra-thin film PET film 140. At this time, the surface having easy adhesiveness of the easily adhesive PET film 130 was brought into contact with the interlayer film 150 for laminated glass. The lamination of the glass plates 110 and 120 and the interlayer film 150 for laminated glass was carried out so that the tin surfaces of the glass plates 110 and 120 were in contact with the interlayer film 150 for laminated glass. The obtained laminate 100A was placed in a rubber bag which was a vacuum back, and degassed for 5 minutes at a vacuum degree of 0.09 MPa. Then, while keeping the degassed state, the laminate 100A was heated up to 90 °C at a heating rate of 6 °C / min and then cooled down to 30 °C. Next, it was returned to normal pressure. The glass plate 110 which had been in contact with the easy-adhesion PET film 130 was peeled off from the easy-adhesion PET film 130 to obtain the laminate 100B shown in Fig. 4. Then, as shown in Fig. 5, the laminated film 160 of the easy-adhesion PET film 130 and the interlayer film 150 for laminated glass was cut along the longitudinal direction (y direction) so that the length in the width direction (x direction) became 25 mm, and a plurality of samples 170 for peel test having a width of 25 mm and adhered to glass were prepared. And then, as shown in Fig. 6, for each sample 170, a 180° peel test was carried out to peel the sample from the glass plate along the longitudinal direction (y direction) at a peel rate of 300 mm / min. The 180° peel test was carried out at room temperature (23 °C) in accordance with JIS K6854-2 (1999) (ISO8510-2 (1990)). Measurement was carried out using a tensile testing machine (manufactured by Instron Corporation, model 5965 universal material testing machine, or its equivalent) as a measuring instrument. At this time, when the displacement at the point 151 (see Fig. 4) where the sample began to peel off from the glass plate was set to 0 mm, the average value of the adhesive force between the displacements of 20 to 180 mm was taken as the adhesive force of the sample. Also, when the displacement at the point where the sample began to peel off from the glass plate was set to 0 mm, the lower limit value of the adhesive force between the displacements of 20 to 180 mm was taken as the lower limit value of the adhesive force of the sample. And the average value of the adhesive forces of all the samples was taken as the adhesive force of the interlayer film for laminated glass in the examples and comparative examples, and the lowest value of the lower limit values of the adhesive forces of all the samples was taken as the lowest value of the adhesive force of the interlayer film for laminated glass in the examples and comparative examples. <Members Used> Glass plate: Manufactured by Misato Glass Co., Ltd., product name "Float Plate Glass", size 30 cm × 30 cm × 3 mm Easy-adhesion PET film: Manufactured by Toyobo Co., Ltd., product name "Cosmo Shine (registered trademark) A4160", size 30 cm × 42 cm × 0.100 mm Ultra-thin film PET film: Manufactured by Toray Industries, Inc., product name "Lumirror Film", size 30 cm × 15 cm × 0.025 mm

[0095] <Appearance after bonding> After maintaining the interlayer film for laminated glass obtained in the examples and comparative examples under the constant temperature and humidity conditions of 23°C and 28% RH for 4 hours, it was laminated between two clear glasses (thickness 3.0 mm) measuring 10 cm in length and 10 cm in width to obtain a laminate. It was placed in a rubber bag which is a vacuum bag and degassed for 5 minutes at a vacuum degree of 0.09 MPa. Then, while remaining degassed, the laminate was heated up to 90°C at a heating rate of 6°C / min and then cooled down to 30°C. Next, it was returned to normal pressure. The obtained optical laminate was left standing on a dark curtain, and the transparency of the optical laminate was visually observed and evaluated in four grades according to the amount of remaining air. A: ······ No remaining air B: ······ Slight remaining air C: ······ Some remaining air D: ······ A large amount of remaining air

[0096] <Adhesion test> After maintaining the interlayer film for laminated glass obtained in the examples and comparative examples under the constant temperature and humidity conditions of 23°C and 28% RH for 4 hours, it was laminated between two clear glasses (thickness 3.0 mm) measuring 10 cm in length and 10 cm in width so that the tin surface of the glass was in contact with the interlayer film for laminated glass to obtain a laminate. The obtained laminate was temporarily pressure-bonded using a heating roll at 170°C. After pressure-bonding, pressure-bonding was performed for 20 minutes using an autoclave under the conditions of 140°C and 1.3 MPa to obtain an optical laminate. The obtained optical laminate was left standing in an environment at a temperature of -18°C ± 0.6°C for 16 hours, and the central part (a part measuring 150 mm in length and 150 mm in width) of this laminated glass was struck with a hammer having a head weight of 0.45 kg until the particle size of the glass became 6 mm or less, and the exposure degree of the film after partial peeling of the glass was measured, and the Pannel value was determined according to Table 1.

[0097]

Table 1

[0098] <High temperature heat resistance> The interlayer film for laminated glass obtained in the examples and comparative examples was held for 4 hours under the constant temperature and humidity conditions of 23°C and 28% RH, and then laminated between two clear glasses (thickness 3.0 mm) measuring 10 cm in length and 10 cm in width to obtain a laminate. The obtained laminate was temporarily crimped using a heating roll at 170°C. After crimping, crimping was performed for 20 minutes using an autoclave under the conditions of 140°C and 1.3 MPa to obtain an optical laminate. After storing the obtained optical laminate in an environment of 100°C for 2000 hours, the presence or absence of foaming and yellowing in the optical laminate were visually confirmed. A: ····· No foaming, no yellowing B: ····· Slight foaming, yellowing at the edges C: ····· Many foams, overall yellowing

[0099] The thermoplastic resins used in the examples and comparative examples were prepared as follows. (Resin 1) Into a reactor equipped with a stirrer, 1800 ml of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, degree of saponification 99 mol%) were put, and heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Next, 30% hydrochloric acid was added to this solution as a catalyst so that the hydrochloric acid concentration became 0.2% by mass, and after adjusting the temperature to 15°C, n-butylaldehyde was added to 10 mol% with stirring. Then, when n-butylaldehyde was added to 60 mol%, white particulate polyvinyl butyral resin precipitated. Ten minutes after precipitation, 30% hydrochloric acid was added so that the hydrochloric acid concentration became 1.8% by mass, and then the temperature was raised to 53°C and aged at a aging temperature of 53°C for 2 hours. Next, the solution was cooled, neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 1 (polyvinyl butyral resin, hydroxyl group amount 30.8 mol%, degree of acetalization 68.4 mol%, degree of acetylation 0.8 mol%, degree of polymerization 1700).

[0100] (Resin 2) Instead of aging at 53°C for 2 hours, it was aged at 63°C for 2 hours. Otherwise, in the same manner as Resin 1, Resin 2 (polyvinyl butyral resin, hydroxyl group content 30.4 mol%, acetalization degree 68.8 mol%, acetylation degree 0.8 mol%, degree of polymerization 1700) was obtained.

[0101] The plasticizers used in the examples and comparative examples are as follows. 3GO: Triethylene glycol - di - 2 - ethylhexanoate

[0102] (Example 1) To 100 parts by mass of Resin 1, 40 parts by mass of a plasticizer (triethylene glycol - di - 2 - ethylhexanoate: 3GO) was mixed to obtain a resin composition. Using the obtained resin composition, an interlayer film for laminated glass with a thickness of 760 μm in film form was produced by an extruder. The interlayer film for laminated glass obtained using an embossing roll was embossed. Also, two 3.0 - mm clear glasses were prepared. Next, on one of the clear glasses, the interlayer film for laminated glass was superposed so that the tin surface of the glass was in contact with the interlayer film for laminated glass, and on the interlayer film for laminated glass, the other clear glass was further superposed to obtain a laminate. The obtained laminate was temporarily pressure - bonded using a heating roll at 170°C. After pressure - bonding, pressure - bonding was performed for 20 minutes using an autoclave under the conditions of 140°C and 1.3 MPa to obtain an optical laminate.

[0103] (Examples 2 - 3 and Comparative Examples 1 - 2) The amount and type of the resin used and the amount of the plasticizer were changed as shown in Table 2, and the same procedure as in Example 1 was carried out except that the embossing roll used for embossing was changed.

[0104]

Table 2

[0105] Since the average value of the adhesion force in the preliminary adhesion force test of the laminated glass interlayer films of Examples 1 to 3 above was 20 N or more, the residual air after lamination could be reduced, and as a result, the transmittance could be increased. Also, since the minimum value of the adhesion force in the preliminary adhesion force test of the laminated glass interlayer films of Examples 1 to 3 was 12 N or more, the adhesion force was high. On the other hand, since the average value of the adhesion force in the preliminary adhesion force test of the laminated glass interlayer films of Comparative Examples 1 and 2 was less than 20 N, the residual air after lamination increased, and as a result, the transmittance decreased significantly. Also, since the minimum value of the adhesion force in the preliminary adhesion force test of the laminated glass interlayer films of Comparative Examples 1 and 2 was less than 12 N, the adhesion force was low.

Explanation of Signs

[0106] 1A, 1B Optical laminate 10, 150 Intermediate film for laminated glass (thermoplastic resin layer (A)) 20 First transparent substrate 30 Second transparent substrate 40 Functional layer 50, 100A, 100B Laminate 110, 120 Glass plate 130 Easy-adhesion PET film 140 Ultra-thin film PET film 160 Laminate film 170 Sample

Claims

1. An interlayer film for laminated glass having a single-layer structure or a multi-layer structure, comprising at least a thermoplastic resin layer (A) containing a thermoplastic resin, when the interlayer film for laminated glass has a multi-layer structure, at least one outermost layer is the thermoplastic resin layer (A), the average value of the adhesion of all samples in a preliminary adhesion test conducted under the following conditions is 20 N or more, the thermoplastic resin is a polyvinyl acetal resin, the amount of hydroxyl groups in the polyvinyl acetal resin is 25 mol% or more and 33 mol% or less, the polyvinyl acetal resin is produced by a production method including an aging step of aging a mixture obtained by mixing polyvinyl alcohol and an aldehyde, an interlayer film for laminated glass, wherein the aging temperature in the aging step is 40°C or more and 57°C or less, and the aging time in the aging step is 100 minutes or more and 140 minutes or less. (Preliminary Adhesion Test Conditions) Prepare two glass plates each with a size of 30 cm × 30 cm, an easy - adhesion PET film with a size of 30 cm × 42 cm having easy - adhesion on one side, an ultra - thin film PET film with a size of 30 cm × 15 - 17 cm, and the intermediate film for laminated glass with a size of 30 cm × 30 cm. Arrange them such that the easy - adhesion surface of the easy - adhesion PET film is in contact with the intermediate film for laminated glass, and the thermoplastic resin layer (A) of the intermediate film for laminated glass is in contact with the glass plate and the ultra - thin film PET film. At this time, in the range from the longitudinal end of the easy - adhesion PET film to a distance of 20 cm in the longitudinal direction of the easy - adhesion PET film, configure it to be in the structure of glass plate / easy - adhesion PET film / intermediate film for laminated glass / glass plate. In the range from a position 20 cm away from the longitudinal end of the easy - adhesion PET film in the longitudinal direction of the easy - adhesion PET film to a position 30 cm away in the longitudinal direction, configure it to be in the structure of glass plate / easy - adhesion PET film / intermediate film for laminated glass / thin film PET film / glass plate. Stack the two glass plates, the easy - adhesion PET film, the ultra - thin film PET film, and the intermediate film for laminated glass. At that time, stack them such that the tin surface of the glass is in contact with the intermediate film for laminated glass. Then, perform vacuum pumping at an absolute pressure of 0.09 MPa for 5 minutes at room temperature. Then, heat up at a heating rate of 6 °C / min to 90 °C, and after reaching 90 °C, cool down to room temperature. Then, after peeling the glass plate that was in contact with the easy - adhesion PET film from the easy - adhesion PET film, cut the laminated film of the easy - adhesion PET film and the intermediate film for laminated glass along the longitudinal direction of the easy - adhesion PET film so that the length in the width direction becomes 25 mm, and prepare 12 samples for the peel test having a width of 25 mm and adhered to the glass. Then, for each sample, perform a 180° peel test of peeling the sample from the glass plate along the longitudinal direction at a peeling speed of 300 mm / min. At this time, when the displacement at the point where the sample starts to peel off from the glass plate is set to 0 mm, the average value of the adhesive force between displacements of 20 - 180 mm is taken as the adhesive force of that sample.

2. In the preliminary adhesion test, when the lower limit value of the adhesion force between 20 mm and 180 mm of displacement is taken as the lower limit value of the adhesion force of the sample with the displacement at the point where the sample starts to peel off from the glass plate being 0 mm, the laminated interlayer film for laminated glass according to claim 1, wherein the minimum value of the lower limit values of the adhesion forces of all samples in the preliminary adhesion test is 12 N or more.

3. The laminated interlayer film for laminated glass according to claim 1, which contains a colorant.

4. The laminated interlayer film for laminated glass according to claim 1, wherein the thermoplastic resin layer (A) further contains a plasticizer.

5. The laminated interlayer film for laminated glass according to claim 4, wherein the plasticizer is triethylene glycol - di - 2 - ethylhexanoate (3GO).

6. The laminated interlayer film for laminated glass according to claim 4, wherein the content of the plasticizer is 30 to 50 parts by mass with respect to 100 parts by mass of the polyvinyl acetal resin.

7. The laminated interlayer film for laminated glass according to any one of claims 1 to 6, and a laminate including a functional layer different from the laminated interlayer film for laminated glass.

8. The laminate according to claim 7, wherein the functional layer is at least one selected from the group consisting of a dimming film, a display element film, a polarizing film, a retardation film, an antireflection film, and a solar cell element.

9. An optical laminate including a first transparent substrate, a second transparent substrate, and the laminated interlayer film for laminated glass according to any one of claims 1 to 6 disposed between the first and second transparent substrates.

10. An optical laminate including a first transparent substrate, a second transparent substrate, and the laminate according to claim 8 disposed between the first and second transparent substrates.

Images