Polyvinyl acetal resin, interlayer for laminated glass, laminate, and laminated glass

Abstract

This polyvinyl acetal resin contains a prescribed structural unit (a), a prescribed structural unit (b), and a prescribed structural unit (c). The integrated value of a peak of a methylene C atom belonging to a predetermined position of the constituent unit (a), the integrated value of a peak of a methylene C atom belonging to a predetermined position of the constituent unit (b), and the integrated value of a peak of a methylene C atom belonging to a predetermined position of the constituent unit (c) in the 13C-NMR map satisfy a predetermined relationship. The degree of acetalization of the polyvinyl acetal resin is 65 mol% or more and less than 75 mol%. According to the invention, according to the present invention, it is possible to provide: a polyvinyl acetal resin with which it is possible to produce an interlayer for laminated glass, said interlayer being capable of suppressing the remaining of air and indentations during crimping without going through an autoclave step under high-temperature and high-pressure conditions; an interlayer for laminated glass comprising the polyvinyl acetal resin; and a laminate comprising the interlayer for laminated glass. And a laminated glass provided with the interlayer for laminated glass or the laminate.

Description

Technical Field

[0001] The present invention relates to a polyvinyl acetal resin, an interlayer film for laminated glass using the polyvinyl acetal resin, a laminate including the interlayer film for laminated glass, and a laminated glass including the interlayer film for laminated glass or the laminate thereof. Background Art

[0002] Conventionally, laminated glass in which an interlayer film is interposed between two glass plates and integrated is well known. The interlayer film is mostly formed of a plasticized polyvinyl acetal in which a plasticizer is blended in a polyvinyl acetal resin. Laminated glass is safe because even if it is broken by an external impact, glass fragments rarely scatter, and thus it is widely used as window glass for vehicles such as automobiles, airplanes, buildings, and the like. As the polyvinyl acetal resin for the interlayer film, for example, the polyvinyl acetal resins described in Patent Documents 1 and 2 can be cited.

[0003] Laminated glass usually has an interlayer film disposed between two glass plates, and after a pre-degassing process, it is heated and pressed 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 film for manufacturing.

[0004] In addition, various studies and improvements have been made on the interlayer film for laminated glass, and Patent Document 1 shows an interlayer film for laminated glass in which the amount of change in thickness during a compression creep test is within a certain range (for example, refer to Patent Document 3).

[0005] In recent years, laminated glass has sometimes been required to have various functions. For example, a functional film such as a light control body may sometimes be disposed between two glass plates. When a functional film such as a light control body is assembled in laminated glass, an interlayer film is disposed between the functional film and each glass plate so that the two glass plates and the functional film are integrated via the interlayer film (for example, refer to Patent Document 4).

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2011-127117

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2019-513865

[0010] Patent Document 3: International Publication No. 2021 / 117596

[0011] Patent Document 4: International Publication No. 2019 / 066042 Summary of the Invention

[0012] Problems to be Solved by the Invention

[0013] However, functional films such as light control films have weak resistance to heat and pressure. When a glass plate, an interlayer film, and a functional film are pressed under the conventional high-temperature and high-pressure conditions using an autoclave, the problem of inactivation of the functional film often occurs. In addition, there are also problems such as the need to heat to a high temperature and a large amount of carbon dioxide emissions. On the other hand, if the autoclave process is not performed or the pressing is carried out using an autoclave at a low temperature, air and indentations may sometimes remain between the interlayer film and the glass plate and between the interlayer film and the functional film during pressing, and the transparency of the laminated glass obtained by pressing deteriorates.

[0014] Therefore, the subject of the present invention is to provide a polyvinyl acetal resin that improves fluidity, flexibility, etc. and improves the thermocompression bonding property at low temperatures. For example, even when the autoclave process under high-temperature and high-pressure conditions is not performed during the manufacture of laminated glass, etc., the remaining of air and indentations during pressing can be suppressed. Another subject of the present invention is to provide an interlayer film for laminated glass containing the polyvinyl acetal resin, a laminate containing the interlayer film for laminated glass, and a laminated glass having the interlayer film for laminated glass or the laminate.

[0015] Means for Solving the Subject

[0016] The inventors of the present invention conducted in-depth research and found that by using a polyvinyl acetal resin having a specified 13 13C-NMR spectrum and a specified degree of acetalization, the above-mentioned subject can be solved, and thus the following present invention has been completed. That is, the present invention provides the following [1] to

[29] .

[0017] [1] A polyvinyl acetal resin containing a structural unit (a) represented by the following formula (a), a structural unit (b) represented by the following formula (b), and a structural unit (c) represented by the following formula (c). When the integral value of the peak of the methylene C atom at the (a)' position attributed to the structural unit (a) in the 13 13C-NMR (nuclear magnetic resonance) measurement is denoted as I(a)', the integral value of the peak of the methylene C atom at the (b)' position attributed to the structural unit (b) is denoted as I(b)', and the integral value of the peak of the methylene C atom at the (c)' position attributed to the structural unit (c) is denoted as I(c)', the following formula (1) is satisfied, and the degree of acetalization of the polyvinyl acetal resin is 65 mol% or more and less than 75 mol%. 13

[0018]

[0019] I(a)' / (I(b)' + I(c)') < 0.30 (1)

[0020] In formulas (b) and (c), R 1 、R​2 and R 3 Each is hydrogen or a hydrocarbon group having 1 to 9 carbon atoms.

[0021] [2] The polyvinyl acetal resin according to [1] above, wherein R 1 , R 2 and R 3 Each of them is an alkyl group having 1 to 6 carbon atoms.

[0022] [3] The polyvinyl acetal resin according to [2] above, wherein R 1 , R 2 and R 3 They are respectively n-propyl.

[0023] [4] The polyvinyl acetal resin according to any one of [1] to [3] above, comprising a structural unit (d) represented by the following formula (d) and a structural unit (e) represented by the following formula (e),

[0024] In will pass 13 C-NMR (nuclear magnetic resonance) 13 When the integral value of the peak of the methine C atom at the (d)' position of the structural unit (d) in the C-NMR spectrum is denoted as I(d)', and the integral value of the peak of the methine C atom at the (e)' position of the structural unit (e) is denoted as I(e)', the following formula (2) is satisfied:

[0025]

[0026] I(d)' / (I(d)'+I(e)')<0.763 (2)

[0027] R in formula (d) and formula (e) 4 and R 5 Each is hydrogen or a hydrocarbon group having 1 to 9 carbon atoms.

[0028] [5] The polyvinyl acetal resin according to any one of [1] to [4], comprising a structural unit (f) represented by the following formula (f), a structural unit (g) represented by the following formula (g), a structural unit (h) represented by the following formula (h), a structural unit (i) represented by the following formula (i), a structural unit (j) represented by the following formula (j), and a structural unit (k) represented by the following formula (k),

[0029] In will pass 13 C-NMR (nuclear magnetic resonance) 13In the \(^{13}\)C-NMR spectrum, the integral value of the peak of the methine C atom at the (f)' position attributed to the structural unit (f) is denoted as I(f)', the integral value of the peak of the methine C atom at the (g)' position attributed to the structural unit (g) is denoted as I(g)', the integral value of the peak of the methine C atom at the (h)'2 position attributed to the structural unit (h) is denoted as I(h)'2, the integral value of the peak of the methine C atom at the (i)' position attributed to the structural unit (i) is denoted as I(i)', the integral value of the peak of the methine C atom at the (j)' position attributed to the structural unit (j) is denoted as I(j)', and the integral value of the peak of the methine C atom at the (k)' position attributed to the structural unit (k) is denoted as I(k)'. When this is the case, the following formula (3) is satisfied:

[0030]

[0031]

[0032] (I(f)'+I(g)'+I(h)'2) / (I(f)'+I(g)'+I(h)'2+I(i)'+I(j)'+I(k)') < 0.23 (3)

[0033] R in formula (i), formula (j), and formula (k) 6 ~R 9 are each hydrogen or a hydrocarbon group having 1 or more and 9 or less carbon atoms.

[0034] [6] The polyvinyl acetal resin according to any one of the above [1] to [5], wherein the weight average molecular weight (Mw) is 220,000 or more.

[0035] [7] The polyvinyl acetal resin according to any one of the above [1] to [6], wherein the polyvinyl acetal resin is produced by a method including a mixing step of mixing polyvinyl alcohol and an aldehyde and a curing step of curing the mixture obtained in the mixing step, and the curing temperature in the curing step is 30°C or more and 65°C or less.

[0036] [8] The polyvinyl acetal resin according to the above [7], wherein the curing temperature is 40°C or more and 57°C or less.

[0037] [9] A method for producing a polyvinyl acetal resin, which includes a mixing step of mixing polyvinyl alcohol and an aldehyde and a curing step of curing the mixture obtained in the mixing step, and the curing temperature in the curing step is 30°C or more and 65°C or less.

[0038]

[10] The method for producing a polyvinyl acetal resin according to the above [9], wherein the curing temperature is 40°C or more and 58°C or less.

[0039]

[11] An interlayer film for laminated glass, which is an interlayer film for laminated glass having a single-layer structure or a multi-layer structure, and at least includes a polyvinyl acetal resin layer containing the polyvinyl acetal resin described in any one of the above [1] to [8].

[0040]

[12] For the interlayer film for laminated glass described in the above

[11] , after compression in a compression creep test carried out under the following conditions, the thickness change amount of the polyvinyl acetal resin layer is 80 μm or more.

[0041] (Compression creep test conditions)

[0042] A specimen with a diameter of 8 mm and a thickness of 700 - 900 μm made of the above polyvinyl acetal resin layer is compressed for 30 minutes under a load of 410 g and at a temperature of 30 °C, and then the thickness (T1) of the specimen is measured. Then, while maintaining a load of 410 g, the temperature is raised from 30 °C to 90 °C at a heating rate of 6 °C / minute. Then, after compression for 5 minutes under a load of 410 g and at a temperature of 90 °C, the thickness (T2) of the specimen is measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the specimen is set as the thickness change amount.

[0043]

[13] For the interlayer film for laminated glass described in the above

[12] , the above thickness change amount is 600 μm or less.

[0044]

[14] For the interlayer film for laminated glass described in any one of the above

[11] to

[13] , the above polyvinyl acetal resin layer further contains a plasticizer.

[0045]

[15] For the interlayer film for laminated glass described in the above

[14] , based on 100 parts by mass of the polyvinyl acetal resin contained in the above polyvinyl acetal resin layer, the content of the plasticizer is 10 parts by mass or more and 100 parts by mass or less.

[0046]

[16] For the interlayer film for laminated glass described in the above

[14] or

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

[0047]

[17] For the interlayer film for laminated glass as described in the above

[16] , the plasticizer is at least one plasticizer selected from triethylene glycol-di-ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glycerol ether, polyoxypropylene diglycerol ether, or derivatives in which a part of the hydrogen atoms of their terminal hydroxyl groups are substituted by alkyl groups.

[0048]

[18] The thermoplastic resin film according to any one of

[11] to

[17] above, wherein the thickness of the polyvinyl acetal resin layer is 100 μm or more and 2000 μm or less.

[0049]

[19] A laminate comprising the interlayer film for laminated glass according to any one of

[11] to

[18] above and a functional layer different from the interlayer film for laminated glass.

[0050]

[20] The laminate according to

[19] above, wherein the functional layer is at least one film selected from a light control film, a display element film, a polarizing film, a retardation film, and an antireflection film.

[0051]

[21] The laminate according to

[19] or

[20] above, wherein the functional layer includes an electronic component.

[0052]

[22] The laminate according to any one of

[19] to

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

[0053]

[23] A laminated glass comprising: a first laminated glass member, a second laminated glass member, and the interlayer film for laminated glass according to any one of

[19] to

[22] above disposed between the first and second laminated glass members.

[0054]

[24] A laminated glass comprising: a first laminated glass member, a second laminated glass member, and the laminate according to

[22] above disposed between the first and second laminated glass members.

[0055]

[25] A method for manufacturing a laminated glass, which is a method for manufacturing the laminated glass according to

[23] or

[24] above, wherein at least a thermoplastic resin film or a laminate is disposed between the first transparent substrate and the second transparent substrate, and they are pressed and bonded to obtain the laminated glass.

[0056]

[26] The method for manufacturing a laminated glass according to

[25] above, wherein the thermoplastic resin film contains a polyvinyl acetal resin, and the polyvinyl acetal resin is manufactured by a method including a mixing step of mixing the polyvinyl alcohol and the aldehyde and a curing step of curing the mixture obtained in the mixing step, and the curing temperature in the curing step is 30 °C or more and 65 °C or less.

[0057]

[27] The method for manufacturing a laminated glass according to

[26] above, wherein the curing temperature is 40 °C or more and 57 °C or less.

[0058]

[28] The manufacturing method of the laminated glass according to any one of

[25] to

[27] above, wherein the optical laminate is obtained by crimping at a temperature of 110°C or lower.

[0059]

[29] The manufacturing method of the laminated glass according to any one of

[25] to

[28] above, wherein the laminated glass is obtained by crimping under a pressure condition of 1.2 MPa or lower.

[0060] Advantages of the Invention

[0061] According to the present invention, it is possible to provide a polyvinyl acetal resin, and an interlayer film for laminated glass capable of suppressing the remaining air and indentation during crimping can be produced without passing through an autoclave process under high temperature and high pressure conditions. In addition, an interlayer film for laminated glass containing the polyvinyl acetal resin, a laminate containing the interlayer film for laminated glass, and a laminated glass having the interlayer film for laminated glass or the laminate can also be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a diagram showing the layer structure of the laminated glass in the first embodiment of the present invention.

[0063] Figure 2 It is a diagram showing the layer structure of the laminated glass in the second embodiment of the present invention.

[0064] Figure 3 (a) to (c) are respectively photographs showing an example of the laminated glass disposed on a dark screen.

[0065] Figure 4 It is a diagram showing the 13 C-NMR spectrum of the polyvinyl acetal resin of Example 2.

[0066] Figure 5 It is a diagram showing the 13 C-NMR spectrum of the polyvinyl acetal resin of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0067] <Polyvinyl Acetal Resin>

[0068] The polyvinyl acetal resin of the present invention contains a structural unit (a) represented by the following formula (a), a structural unit (b) represented by the following formula (b), and a structural unit (c) represented by the following formula (c). And the following formula (1) is satisfied. It should be noted that I(a)' in the formula (1) is obtained by 13 measured by C-NMR (nuclear magnetic resonance) 13 the integral value of the peak of the methylene C atom at the (a)' position attributed to the structural unit (a) in the C-NMR spectrum. In addition, I(b)' in the formula (1) is 13The integral value of the peak attributable to the methylene C atom at the (b)' position of the structural unit (b) in the C-NMR spectrum. 13 The integral value of the peak attributable to the methylene C atom at the (c)' position of the structural unit (c) in the C-NMR spectrum. The degree of acetalization of the polyvinyl acetal resin of the present invention is 65 mol% or more and less than 75 mol%.

[0069]

[0070] It should be noted that R in formula (b) and formula (c) 1 , R 2 and R 3 Each is hydrogen or a hydrocarbon group having 1 to 9 carbon atoms.

[0071] I(a)' / (I(b)'+I(c)')<0.30 (1)

[0072] ( 13 C-NMR spectrum)

[0073] As described above, the polyvinyl acetal resin of the present invention satisfies the above formula (1). When the polyvinyl acetal resin does not satisfy the above formula (1), it is difficult to improve the fluidity and softness of the polyvinyl acetal resin at low temperatures, and it is difficult to improve the thermal compression bonding at low temperatures. Therefore, in an autoclave at low temperatures or in a method other than an autoclave, when an intermediate film for laminated glass made using polyvinyl acetal resin is pressed onto a laminated glass component or a functional layer to produce laminated glass, sometimes air or indentations remain between the intermediate film for laminated glass and the laminated glass component or the functional layer, and the transparency of the laminated glass deteriorates. Therefore, for example, in the case of producing laminated glass using an intermediate film for laminated glass made using polyvinyl acetal resin, in order to prevent the residue of air or indentations, an autoclave under high temperature and high pressure conditions is required.

[0074] From this viewpoint, the polyvinyl acetal resin of the present invention preferably satisfies the following formula (1-a), more preferably satisfies the following formula (1-b), further preferably satisfies the following formula (1-c), further preferably satisfies the following formula (1-d), and particularly preferably satisfies the following formula (1-e).

[0075] I(a)' / (I(b)'+I(c)')≤0.295(1-a)

[0076] I(a)' / (I(b)'+I(c)')≤0.290(1-b)

[0077] I(a)' / (I(b)'+I(c)')≤0.285(1-c)

[0078] I(a)’ / (I(b)’ + I(c)’) ≤ 0.280(1 - d)

[0079] I(a)’ / (I(b)’ + I(c)’) ≤ 0.274(1 - e)

[0080] The lower limit of the range of the value of I(a)’ / (I(b)’ + I(c)’) in the polyvinyl acetal resin of the present invention is not particularly limited. For example, it is 0.10, preferably 0.15, more preferably 0.20, and further preferably 0.23.

[0081] I(a)’ is, for example, the integrated value in the range of 44.6 to 46 ppm of the peak of the methylene C atom at the (a)’ position belonging to the structural unit (a). In addition, I(b)’ is, for example, the integrated value in the range of 43 to 44.6 ppm of the peak of the methylene C atom at the (b)’ position belonging to the structural unit (b). Further, I(c)’ is, for example, the integrated value in the range of 43 to 44.6 ppm of the peak of the methylene C atom at the (c)’ position belonging to the structural unit (c). The peaks of the methylene C atoms at the (b)’ position belonging to the above structural unit (b) and the (c)’ position belonging to the above structural unit (c) both exist in the range of 43 to 44.6 ppm. Therefore, (I(b)’ + I(c)’) is the integrated value of the peaks existing in the range of 43 to 44.6 ppm.

[0082] It should be noted that, based on the value of I(a)’ / (I(b)’ + I(c)’) of the polyvinyl acetal resin, the distribution state of the hydroxyl groups in the polyvinyl acetal resin can be known. For example, if the value of I(a)’ / (I(b)’ + I(c)’) is large, it can be considered that the hydroxyl groups are concentrated in the polyvinyl acetal resin. If the value of I(a)’ / (I(b)’ + I(c)’) is small, it can be considered that the hydroxyl groups exist randomly. Moreover, it can be considered that by making the hydroxyl groups in the polyvinyl acetal resin exist randomly, the fluidity, flexibility, etc. of the polyvinyl acetal resin at low temperatures are improved. As described above, the thermocompression bonding property, etc. at low temperatures become good.

[0083] The value of I(a)’ / (I(b)’ + I(c)’) in the polyvinyl acetal resin of the present invention can be adjusted by manufacturing conditions, etc. during the manufacture of the polyvinyl acetal resin. Specifically, as described later, the above value can be adjusted by the curing temperature in the curing process performed during the manufacture of the polyvinyl acetal resin. For example, it can be considered that by setting the curing temperature to a relatively low temperature, the conversion of the polyvinyl acetal resin from the racemic structure to the meso structure can be suppressed. As a result, the existence of the hydroxyl groups in the polyvinyl acetal resin becomes random and the value of I(a)’ / (I(b)’ + I(c)’) becomes low.

[0084] In the polyvinyl acetal resin of the present invention, 13 The 13C-NMR spectrum can be measured, for example, by the method described in the examples.

[0085] The polyvinyl acetal resin of the present invention preferably contains a structural unit (d) represented by the following formula (d) and a structural unit (e) represented by the following formula (e). And it preferably satisfies the following formula (2). It should be noted that I(d)' in formula (2) is 13 The integral value of the peak of the methylene C atom at the (d)' position attributed to the structural unit (d) in the 13C-NMR spectrum. In addition, I(e)' in formula (2) is 13 The integral value of the peak of the methylene C atom at the (e)' position attributed to the structural unit (e) in the 13C-NMR spectrum.

[0086]

[0087]

[0088] It should be noted that R in formula (d) and formula (e) 4 and R 5 are each hydrogen or a hydrocarbon group having 1 or more and 9 or less carbon atoms.

[0089] I(d)' / (I(d)' + I(e)') < 0.763 (2)

[0090] When the polyvinyl acetal resin satisfies the above formula (2), the fluidity, flexibility, etc. of the polyvinyl acetal resin at low temperature are likely to become good, and it is easier to improve the thermal bonding property at low temperature. Therefore, the interlayer film for laminated glass made of the polyvinyl acetal resin can be more easily laminated with the laminated glass component and the functional layer by an autoclave at low temperature or a method other than an autoclave to produce laminated glass. That is, when producing laminated glass by laminating the interlayer film for laminated glass with the laminated glass component and the functional layer by an autoclave at low temperature or a method other than an autoclave, it is possible to further suppress: air remaining between the interlayer film for laminated glass and the laminated glass component or the functional layer, and the transparency of the laminated glass deteriorating due to indentations. From such a viewpoint, the polyvinyl acetal resin of the present invention more preferably satisfies the following formula (2-a), further preferably satisfies the following formula (2-b), and particularly preferably satisfies the following formula (2-c).

[0091] I(d)' / (I(d)' + I(e)') ≤ 0.761 (2-a)

[0092] I(d)' / (I(d)' + I(e)') ≤ 0.757 (2-b)

[0093] I(d)’ / (I(d)’ + I(e)’) ≤ 0.754(2 - c)

[0094] There is no particular limitation on the lower limit value of the range of the value of I(d)’ / (I(d)’ + I(e)’) in the polyvinyl acetal resin of the present invention. For example, it is 0.50, preferably 0.60, more preferably 0.65, and further preferably 0.70.

[0095] I(d)’ is, for example, the integrated value in the range of 98.5 to 101.4 ppm of the peak of the methylene C atom at the (d)’ position attributed to the structural unit (d). In addition, I(e)’ is, for example, the integrated value in the range of 92.5 to 94.5 ppm of the peak of the methylene C atom at the (e)’ position attributed to the structural unit (e).

[0096] The value of I(d)’ / (I(d)’ + I(e)’) in the polyvinyl acetal resin represents the ratio of the meso form structure in the polyvinyl acetal resin. Moreover, it can be considered that if the ratio of the meso form structure in the polyvinyl acetal resin becomes smaller, acetalization proceeds under mild reaction conditions, and as a result, it is difficult for hydroxyl groups to exist in an aggregated (block) form, and the flexibility of the polyvinyl acetal resin is improved.

[0097] The value of I(d)’ / (I(d)’ + I(e)’) in the polyvinyl acetal resin of the present invention can be adjusted by manufacturing conditions, etc. when manufacturing the polyvinyl acetal resin. Specifically, as described later, the above value can be adjusted by the curing temperature in the curing process when manufacturing the polyvinyl acetal resin. For example, it can be considered that by setting the curing temperature to a relatively low temperature, the conversion of the polyvinyl acetal resin from the racemic form structure to the meso form structure can be suppressed, and as a result, the value of I(d)’ / (I(d)’ + I(e)’) in the polyvinyl acetal resin can be reduced.

[0098] The polyvinyl acetal resin of the present invention preferably contains a structural unit (f) represented by the following formula (f), a structural unit (g) represented by the following formula (g), a structural unit (h) represented by the following formula (h), a structural unit (i) represented by the following formula (i), a structural unit (j) represented by the following formula (j), and a structural unit (k) represented by the following formula (k). And, it preferably satisfies the following formula (3). In addition, I(f)’ in formula (3) is 13 the integrated value of the peak of the methine C atom at the (f)’ position attributed to the structural unit (f) in the C - NMR spectrum. In addition, I(g)’ in formula (3) is 13 the integrated value of the peak of the methine C atom at the (g)’ position attributed to the structural unit (g) in the C - NMR spectrum. Furthermore, I(h)’2 in formula (3) is 13The integral value of the peak of the methine C atom at the (h)'2 position attributed to the structural unit (h) in the 13C-NMR spectrum. Additionally, I(i)' in formula (3) is 13 The integral value of the peak of the methine C atom at the (i)' position attributed to the structural unit (i) in the 13C-NMR spectrum. Further, I(j)' in formula (3) is 13 The integral value of the peak of the methine C atom at the (j)' position attributed to the structural unit (j) in the 13C-NMR spectrum. Additionally, I(k)' in formula (3) is 13 The integral value of the peak of the methine C atom at the (k)' position attributed to the structural unit (k) in the 13C-NMR spectrum.

[0099]

[0100]

[0101] It should be noted that R in formula (i), formula (j), and formula (k) 6 ~R 9 are each hydrogen or a hydrocarbon group having 1 or more and 9 or less carbon atoms.

[0102] (I(f)’ + I(g)’ + I(h)’2) / (I(f)’ + I(g)’ + I(h)’2 + I(i)’ + I(j)’ + I(k)’) < 0.23 (3)

[0103] When the polyvinyl acetal resin satisfies the above formula (3), the fluidity, flexibility, etc. of the polyvinyl acetal resin at low temperatures are likely to become good, and it is easier to improve the thermocompression bonding property at low temperatures. Therefore, the interlayer film for laminated glass made of the polyvinyl acetal resin can be more easily laminated with the laminated glass component and the functional layer by an autoclave at low temperature or a method other than an autoclave to produce laminated glass. That is, when producing laminated glass by laminating the interlayer film for laminated glass with the laminated glass component and the functional layer by an autoclave at low temperature or a method other than an autoclave, it is possible to further suppress: air remaining between the interlayer film for laminated glass and the laminated glass component or the functional layer, and the transparency of the laminated glass deteriorating due to indentations. From this perspective, the polyvinyl acetal resin of the present invention more preferably satisfies the following formula (3-a), further preferably satisfies the following formula (3-b), and particularly preferably satisfies the following formula (3-c).

[0104] (I(f)’ + I(g)’ + I(h)’2) / (I(f)’ + I(g)’ + I(h)’2 + I(i)’ + I(j)’ + I(k)’) ≤ 0.225 (3-a)

[0105] (I(f)’ + I(g)’ + I(h)’2) / (I(f)’ + I(g)’ + I(h)’2 + I(i)’ + I(j)’ + I(k)’) ≤ 0.222(3 - b)

[0106] (I(f)’ + I(g)’ + I(h)’2) / (I(f)’ + I(g)’ + I(h)’2 + I(i)’ + I(j)’ + I(k)’) ≤ 0.220(3 - c)

[0107] The lower limit value of the range of the value of (I(f)’ + I(g)’ + I(h)’2) / (I(f)’ + I(g)’ + I(h)’2 + I(i)’ + I(j)’ + I(k)’) in the polyvinyl acetal resin of the present invention is not particularly limited. For example, it is 0.10, preferably 0.15, and more preferably 0.17.

[0108] I(f)’ is, for example, the integrated value in the range of 64.0 to 64.8 ppm of the peak of the methylene C atom at the (f)’ position attributed to the structural unit (f). In addition, I(g)’ is, for example, the integrated value in the range of 65.8 to 66.6 ppm of the peak of the methylene C atom at the (g)’ position attributed to the structural unit (g). Furthermore, I(h)’2 is, for example, the integrated value of the peak calculated by the following formula (4). The peaks of the methylene C atom at the (h)’2 position attributed to the structural unit (h) and the methylene C atom at the (h)’1 position attributed to the structural unit (e) are both in the range of 66.6 to 70.0 ppm. Therefore, although the cumulative value of the sum of I(h)’1 and I(h)’2 can be measured, it is difficult to measure only I(h)’2. Therefore, I(h)’2 is preferably calculated by the following formula (4). In addition, I(i)’ is, for example, the integrated value in the range of 61.7 to 63.1 ppm of the peak of the methylene C atom at the (i)’ position attributed to the structural unit (i). In addition, I(j)’ is, for example, the integrated value in the range of 64.8 to 65.8 ppm of the peak of the methylene C atom at the (j)’ position attributed to the structural unit (j). Furthermore, I(k)’ is, for example, the integrated value in the range of 63.1 to 64.0 ppm of the peak of the methylene C atom at the (k)’ position attributed to the structural unit (k).

[0109] I(h)’2 = (I(h)’1 + I(h)’2) - I(l)’ × (I(e)’ ÷ I(d)’) (4)

[0110] In the formula, the integral value of the peak of the methylene C atom at the (h)'1 position belonging to the structural unit (e) is I(h)'1. The value of (I(h)'1 + I(h)'2) is the integral value of the peak existing in the range of 66.6 to 70.0 ppm. I(l)' is, for example, the integral value in the range of 71.0 to 74.5 ppm, which is the position of the peak of the methylene C atom at the (l)' position belonging to the structural unit (d). As described above, I(d)' is, for example, the integral value in the range of 98.5 to 101.4 ppm, which is the peak of the methylene C atom at the (d)' position belonging to the structural unit (d). In addition, I(e)' is, for example, the integral value in the range of 92.5 to 94.5 ppm, which is the peak of the methylene C atom at the (e)' position belonging to the structural unit (e).

[0111] The value of (I(f)' + I(g)' + I(h)'2) / (I(f)' + I(g)' + I(h)'2 + I(i)' + I(j)' + I(k)') in the polyvinyl acetal resin represents the proportion of the hydroxyl groups of three consecutive structures in the polyvinyl acetal resin. Moreover, it can be considered that by reducing the proportion of the hydroxyl groups of three consecutive structures in the polyvinyl acetal resin, the flexibility and fluidity of the polyvinyl acetal resin are improved, and the thermocompression bonding property at low temperature becomes good.

[0112] The value of (I(f)' + I(g)' + I(h)'2) / (I(f)' + I(g)' + I(h)'2 + I(i)' + I(j)' + I(k)') in the polyvinyl acetal resin of the present invention can be adjusted according to the manufacturing conditions and the like when manufacturing the polyvinyl acetal resin. Specifically, as described later, the above value can be adjusted by the curing temperature in the curing process when manufacturing the polyvinyl acetal resin. For example, it can be considered that by making the curing temperature a lower temperature, the transition of the polyvinyl acetal resin from the racemic structure to the meso structure is suppressed. As a result, the presence of hydroxyl groups in the polyvinyl acetal resin becomes random. And it can be considered that the value of (I(f)' + I(g)' + I(h)'2) / (I(f)' + I(g)' + I(h)'2 + I(i)' + I(j)' + I(k)') decreases. Moreover, it can be considered that the generation of hydroxyl groups of three consecutive structures in the polyvinyl acetal resin is suppressed, and the above value becomes smaller.

[0113] The above R in the above formulas (b) to (e), (i), (j) and (k) 1 ~R 9Examples thereof include n-propyl, isopropyl, n-butyl, 1-ethylpropyl, n-pentyl, n-heptyl, n-octyl, n-nonyl, hydrogen, methyl, aryl, etc. Among these, alkyl groups having about 1 to 6 carbon atoms such as n-propyl, n-butyl, and n-pentyl are preferred, and n-propyl is more preferred. Therefore, the polyvinyl acetal resin is preferably polyvinyl butyral resin.

[0114] (Degree of acetalization)

[0115] The degree of acetalization of the polyvinyl acetal resin of the present invention is 65 mol% or more and less than 75 mol%. When the degree of acetalization of the polyvinyl acetal resin is less than 65 mol%, the number of hydroxyl groups in the polyvinyl acetal resin increases, and in addition, the distribution of hydroxyl groups becomes less likely to be random, and sometimes the flexibility of the polyvinyl acetal resin becomes insufficient. On the other hand, if it is 75 mol% or more, the adhesiveness to glass and the like becomes low, and it is sometimes difficult to improve the thermocompression bonding property. Therefore, when the degree of acetalization is outside the above range, when manufacturing laminated glass by laminating an interlayer film for laminated glass with a laminated glass component and a functional layer using an autoclave at low temperature or a method other than an autoclave, air or indentations may remain between the interlayer film for laminated glass and the laminated glass component or the functional layer, and the transparency of the laminated glass deteriorates.

[0116] From such a viewpoint, the degree of acetalization of the polyvinyl acetal resin of the present invention is preferably 67 mol to 74 mol, more preferably 68 mol to 73 mol, and further preferably 69 mol to 72 mol.

[0117] It should be noted that the degree of acetalization refers to the degree of butyralization when the acetal group is a butyral group and the polyvinyl acetal resin (A) is polyvinyl butyral resin.

[0118] The above degree of acetalization is a value obtained by dividing the value obtained by subtracting the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups from the total amount of ethylene groups in the main chain by the total amount of ethylene groups in the main chain and expressing it as a mole fraction in percentage. The degree of acetalization (degree of butyralization) only needs to be calculated based on the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups obtained by the steps described in the examples.

[0119] (Weight average molecular weight)

[0120] The weight-average molecular weight (Mw) of the polyvinyl acetal resin of the present invention is preferably 220,000 or more. When the weight-average molecular weight (Mw) of the polyvinyl acetal resin is 220,000 or more, it is possible to suppress the generation of air bubbles in the peripheral portion of the interlayer film for laminated glass produced using the polyvinyl acetal resin during the lamination of the interlayer film for laminated glass. It should be noted that if air bubbles are generated in the peripheral portion of the interlayer film for laminated glass during lamination, it will cause poor appearance of the laminated glass. From this perspective, the weight-average molecular weight (Mw) of the polyvinyl acetal resin of the present invention is more preferably 230,000 or more, and further preferably 240,000 or more. In addition, the weight-average molecular weight (Mw) of the polyvinyl acetal resin of the present invention is preferably 310,000 or less. When the weight-average molecular weight (Mw) of the polyvinyl acetal resin is 310,000 or less, the interlayer film for laminated glass produced using the polyvinyl acetal resin has sufficient flexibility. From this perspective, the weight-average molecular weight (Mw) of the polyvinyl acetal resin of the present invention is more preferably 305,000 or less, and further preferably 300,000 or less.

[0121] It should be noted that the weight-average molecular weight (Mw) of the polyvinyl acetal resin is measured by gel permeation chromatography.

[0122] (aldehyde)

[0123] The polyvinyl acetal resin of the present invention is preferably a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol (PVA) with an aldehyde.

[0124] The above-mentioned aldehyde is not particularly limited, and aldehydes having 1 to 10 carbon atoms are usually preferably used. The aldehydes having 1 to 10 carbon atoms are not particularly limited, and examples thereof include n-butanal, isobutanal, n-pentanal, 2-ethylbutanal, n-hexanal, n-octanal, n-nonanal, n-decanal, formaldehyde, acetaldehyde, benzaldehyde, etc. These aldehydes can be used alone or in combination of two or more.

[0125] Among the above, n-butanal, n-hexanal, and n-pentanal are preferred, and n-butanal is more preferred. Therefore, the polyvinyl acetal resin is preferably polyvinyl butyral resin.

[0126] (polyvinyl alcohol (PVA))

[0127] Polyvinyl alcohol (PVA) is obtained, for example, by saponifying polyvinyl esters such as polyvinyl acetate. The saponification degree of polyvinyl alcohol is usually 70 to 99.9 mol%.

[0128] The average degree of polymerization of PVA is preferably 200 or more, more preferably 500 or more, still more preferably 1000 or more, and even more preferably 1500 or more. If the average degree of polymerization is set to be above the above lower limit, the penetration resistance of the laminated glass is improved when used in the laminated glass. In addition, the average degree of polymerization of PVA is preferably 5000 or less, more preferably 4000 or less, still more preferably 3500 or less, and even more preferably 2500 or less.

[0129] It should be noted that the average degree of polymerization of polyvinyl alcohol is determined by the method according to JIS K6726 "Test Methods for Polyvinyl Alcohol". In addition, when using two or more kinds of polyvinyl alcohol as raw materials, the average degree of polymerization of polyvinyl alcohol can be estimated by calculation based on the average degree of polymerization of each polyvinyl alcohol.

[0130] As the polyvinyl alcohol used as the raw material of the polyvinyl acetal resin, two or more kinds of polyvinyl alcohol with different average degrees of polymerization can be used. In this case, it is preferable to use a substance in which two or more kinds of polyvinyl alcohol are mixed as the raw material, and the polyvinyl acetal resin is produced by the production method described below.

[0131] When using two or more kinds of polyvinyl alcohol, for example, it is preferable to use a first polyvinyl alcohol with an average degree of polymerization of 1500 or more and a second polyvinyl alcohol with an average degree of polymerization of 1000 or less. By using two or more kinds of polyvinyl alcohol with different average degrees of polymerization, it is easy to increase the thickness change amount described below.

[0132] 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. In addition, the average degree of polymerization of the second polyvinyl alcohol is preferably 200 or more and 1000 or less, more preferably 300 or more and 900 or less, still more preferably 400 or more and 700 or less.

[0133] When using the first and second polyvinyl alcohols, the mixing ratio of the first polyvinyl alcohol and the second polyvinyl alcohol is not particularly limited. The blending amount of the second polyvinyl alcohol is preferably 1% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 40% by mass or less, still more preferably 3% by mass or more and 30% by mass or less, and even more preferably 5% by mass or more and 15% by mass or less, based on the total amount of the first and second polyvinyl alcohols.

[0134] (Hydroxyl amount)

[0135] The hydroxyl group content of the polyvinyl acetal resin of the present invention is preferably 15 mol% or more, and more preferably 38 mol% or less. By setting the hydroxyl group content to 15 mol% or more, the adhesiveness is likely to be good. In addition, when used for laminated glass, the through-resistance of the laminated glass is likely to be good. Further, by setting the hydroxyl group content to 38 mol% or less, flexibility is easily ensured, and it is possible to prevent the laminated glass from becoming too hard or the thickness change amount described later from becoming low.

[0136] The above-mentioned hydroxyl group content is more preferably 20 mol% or more, and further preferably 25 mol% or more. In addition, the above-mentioned hydroxyl group content is more preferably 35.0 mol% or less, and further preferably 33 mol% or less.

[0137] When using polyvinyl butyral resin as the polyvinyl acetal resin, from the same viewpoint, the hydroxyl group content is 15 mol% or more, and more preferably 38 mol% or less, more preferably 20 mol% or more, further preferably 25 mol% or more, more preferably 35 mol% or less, and further preferably 33 mol% or less.

[0138] The hydroxyl group content of the polyvinyl acetal resin is a value expressed as a percentage of the mole fraction obtained by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain.

[0139] The amount of ethylene groups to which the above-mentioned hydroxyl groups are bonded can be measured by the steps described in the examples.

[0140] (Degree of acetylation)

[0141] The degree of acetylation of the polyvinyl acetal resin of the present invention is preferably 30 mol% or less, more preferably 20 mol% or less, further preferably 10 mol% or less, and even more preferably 2 mol% or less. If the above-mentioned degree of acetylation is below the above upper limit, the moisture resistance of the polymer film becomes high. In addition, the above-mentioned degree of acetylation is not particularly limited, and is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more.

[0142] The above-mentioned degree of acetylation is a value expressed as a percentage of the mole fraction obtained by dividing the amount of ethylene groups to which acetyl groups are bonded by the total amount of ethylene groups in the main chain. The amount of ethylene groups to which the above-mentioned acetyl groups are bonded can be measured by the steps described in the examples.

[0143] (Modified polyvinyl acetal resin)

[0144] The polyvinyl acetal resin of the present invention can be an unmodified polyvinyl acetal resin or a modified polyvinyl acetal resin.

[0145] The modified polyvinyl acetal resin has a structure other than an acetal group, a hydroxyl group, and an acetyl group (modifying group), and preferably has a modifying group in the side chain. Examples of the modifying group include a group having a polyalkylene oxide structure in the side chain, a group having an alkyl group other than an acetal group and an acetyl group (for example, an alkyl group having about 2 to 30 carbon atoms) in the side chain, and the like.

[0146] The amount of modification is not particularly limited, and is, for example, 0.1 mol% or more and about 10 mol%. It should be noted that the amount of modification represents the ratio of the functional group to all vinyl monomer units constituting the polyvinyl acetal resin.

[0147] (Method for producing polyvinyl acetal resin)

[0148] The polyvinyl acetal resin of the present invention is preferably produced by a production method including a mixing step of mixing the above-mentioned polyvinyl alcohol and the above-mentioned aldehyde and a curing step of curing the mixture obtained in the mixing step.

[0149] In the mixing step, polyvinyl alcohol and aldehyde can be mixed according to a conventional method. In addition, a catalyst such as an acid catalyst for promoting the acetalization reaction can be further added in addition to polyvinyl alcohol and aldehyde. For example, aldehyde can be added to a mixture in which an acid catalyst is added to polyvinyl alcohol under low-temperature conditions of about 0 to 40°C. In addition, a solvent such as water is usually added. In addition, when two or more kinds of polyvinyl alcohol are used (for example, when two or more kinds of polyvinyl alcohol having different molecular weights are used), two or more kinds of polyvinyl alcohol can be mixed with aldehyde.

[0150] As the above-mentioned curing step, there is no particular limitation. For example, a catalyst such as an acid catalyst can be added to the mixture (reaction mixture) obtained by the above-mentioned mixing step, heated to the curing temperature, and maintained at the curing temperature for a certain period of time. In this production method, acetalization of polyvinyl alcohol is carried out in the mixing step and the curing step to obtain a polyvinyl acetal resin.

[0151] The reaction mixture can be appropriately cooled after being maintained at the above-mentioned curing temperature for a certain period of time, then neutralized, and then washed with water, dried, etc. as needed.

[0152] Examples of the acid catalyst added in the above-mentioned mixing step and curing step include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, and boric acid. In addition, in the curing step, the concentration of the acid catalyst can be adjusted to, for example, 0.5% by mass or more and 5% by mass or less, preferably adjusted to a concentration of 1% by mass or more and 2.5% by mass or less.

[0153] The curing temperature in the curing process can be carried out at a relatively low temperature, for example, above 30°C and below 65°C, preferably above 35°C and below 60°C, more preferably above 40°C and below 58°C. In addition, the time maintained at the above curing temperature (curing time) only needs to be longer than a certain time, for example, above 75 minutes and below 180 minutes, preferably above 90 minutes and below 150 minutes, more preferably above 100 minutes and below 140 minutes.

[0154] It is speculated that if the above curing temperature and curing time are set within the above desired ranges, the hydroxyl groups in the polyvinyl acetal resin are likely to be evenly distributed in the molecule. Thus, the polyvinyl acetal resin of the present invention easily satisfies the requirements of the above formula (1).

[0155] <Interlayer film for laminated glass>

[0156] The interlayer film for laminated glass of the present invention has a single-layer structure or a multi-layer structure and at least includes a polyvinyl acetal resin layer containing the polyvinyl acetal resin of the present invention.

[0157] (Polyvinyl acetal resin layer)

[0158] As described above, the polyvinyl acetal resin layer contains the polyvinyl acetal resin of the present invention. The content of the polyvinyl acetal resin in the polyvinyl acetal resin layer 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% based on the total amount of the thermoplastic resin contained in the polyvinyl acetal resin layer. Therefore, the thermoplastic resin contained in the polyvinyl acetal resin layer can be composed only of the polyvinyl acetal resin.

[0159] As long as the polyvinyl acetal resin layer exhibits the effects of the present invention, it may contain a thermoplastic resin other than the polyvinyl acetal resin of the present invention as the thermoplastic resin. Examples of the thermoplastic resin other than the polyvinyl acetal resin of the present invention include: (meth)acrylic resins, polyvinyl acetal resins other than the polyvinyl acetal resin of the present invention, polyvinyl alcohol resins (PVA), polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymers (EVOH), ethylene-methyl methacrylate copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, styrene-butadiene copolymer resins, etc. These thermoplastic resins can be used alone or in combination of two or more.

[0160] Among the thermoplastic resins other than the polyvinyl acetal resin of the present invention, from the viewpoint of achieving both moisture and heat resistance and impact resistance, polyvinyl acetal resins other than the polyvinyl acetal resin of the present invention, polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymers (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and styrene-butadiene copolymer resins are preferred.

[0161] The amount of thickness change during compression in the compression creep test performed under the following conditions for the polyvinyl acetal resin layer is preferably 80 μm or more.

[0162] (Compression creep test)

[0163] First, a specimen with a diameter of 8 mm and a thickness of 700 - 900 μm (e.g., 800 μm) is made from the polyvinyl acetal resin layer. Then, after compressing the specimen under a load of 410 g and at 30°C for 30 minutes, the thickness (T1) of the specimen is measured. Then, while maintaining the load of 410 g, the temperature is raised from 30°C to 90°C at a heating rate of 6°C / minute. Then, after compressing under a load of 410 g and at 90°C for 5 minutes, the thickness (T2) of the specimen is measured. The absolute value of the difference between the thickness (T1) and the thickness (T2) of the specimen is taken as the amount of thickness change.

[0164] It should be noted that the specimen can be made as follows: When the thickness of the polyvinyl acetal resin layer is less than 700 μm, two or more polyvinyl acetal resin layers are overlapped, and are appropriately heat-pressed and bonded, etc., and are adjusted to a thickness of 700 - 900 μm by pressing, etc., and then are cut, etc. to form a cylindrical shape with a diameter of 8 mm.

[0165] In addition, regarding the specimen, when the thickness of the polyvinyl acetal resin layer exceeds 900 μm, it can be adjusted to a thickness of 700 - 900 μm by heat-pressing, etc. as needed, and then is cut, etc. to form a cylindrical shape with a diameter of 8 mm, thereby making the specimen.

[0166] It should be noted that when the interlayer film for laminated glass is a multi-layer structure, the polyvinyl acetal resin layer is peeled off from other layers, and the polyvinyl acetal resin layer is taken out. In addition, when the interlayer film for laminated glass is a multi-layer structure and the intermediate layer is a polyvinyl acetal resin layer, only the skin layer is peeled off, and only the skin layer is used to make a specimen with a pressed film thickness of 700 - 900 μm.

[0167] In addition, in the case where there are irregularities such as indentations on the surface of the specimen, the specimen can be adjusted to have a flat surface by appropriately performing hot pressing or the like on the specimen, and then cut or the like so as to form a cylindrical shape with a diameter of 8 mm, thereby producing the specimen.

[0168] When the above-mentioned thickness change amount of the polyvinyl acetal resin layer is 80 μm or more, when manufacturing laminated glass by laminating an interlayer film for laminated glass with a laminated glass component and a functional layer using an autoclave at low temperature or a method other than an autoclave, it is possible to suppress the remaining air and indentations between the interlayer film for laminated glass and the laminated glass component or the functional layer.

[0169] From such a viewpoint, the thickness change amount of the polyvinyl acetal resin layer is more preferably 90 μm or more, further preferably 100 μm or more, and still further preferably 110 μm or more. If the thickness change amount becomes larger in this way, the amount of remaining air and indentations during lamination can be further reduced, and the transparency of the laminated glass can be improved.

[0170] The thickness change amount of the polyvinyl acetal resin layer is, for example, 600 μm or less, preferably 550 μm or less, more preferably 500 μm or less, and still further preferably 450 μm or less. If the thickness change amount is set to a certain value or less, it is possible to further suppress the generation of bubbles in the peripheral portion of the interlayer film for laminated glass during lamination.

[0171] The thickness change amount can be adjusted, for example, according to the polyvinyl acetal resin contained in the polyvinyl acetal resin layer. Moreover, the thickness change amount can be further adjusted according to the amount, type, etc. of the plasticizer contained in the polyvinyl acetal resin layer. For example, if the amount of the plasticizer is increased, the thickness change amount tends to become larger.

[0172] (Plasticizer)

[0173] The polyvinyl acetal resin layer preferably contains a plasticizer. By containing a plasticizer, the polyvinyl acetal resin layer becomes softer, and the adhesiveness, penetration resistance, etc. of the polyvinyl acetal resin layer to various adherends can be further improved. In addition, the thickness change amount is easily increased.

[0174] Examples of the plasticizer include: organic ester plasticizers, and organic phosphorus-based plasticizers such as organic phosphoric acid ester plasticizers and organic phosphite plasticizers, organic ether-based plasticizers such as polyalkylene glycol-based plasticizers, and alcohol-based plasticizers.

[0175] The plasticizer can be used alone as 1 type, or 2 or more types can be used in combination. Among the above, organic ester plasticizers and organic ether-based plasticizers are preferred.

[0176] As preferred organic ester plasticizers, mention may be made of mono-carboxylic acid esters and poly-carboxylic acid esters. As the mono-carboxylic acid ester, mention may be made of esters formed from diols and mono-carboxylic acids. As the diols, mention may be made of polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms, and the number of repetitions of the alkylene unit is 2 to 10, preferably 2 to 4. In addition, as the diol, it may be a monoalkylene glycol having 2 to 4 carbon atoms, preferably 2 or 3 carbon atoms (i.e., the repeating unit is 1).

[0177] Specifically, as the diols, mention may be made of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, butylene glycol, and the like.

[0178] As the mono-carboxylic acid, mention may be made of organic acids having 3 to 10 carbon atoms. Specifically, mention may be made of butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, enanthic acid, n-octanoic acid, 2-ethylhexanoic acid, n-nonanoic acid, decanoic acid, and the like.

[0179] As specific mono-carboxylic acid esters, mention may be made of triethylene glycol bis(2-ethylbutyrate), triethylene glycol bis(2-ethylhexanoate), triethylene glycol dicaprylate, triethylene glycol bis(n-octanoate), triethylene glycol bis(n-heptanoate), tetraethylene glycol bis(n-heptanoate), tetraethylene glycol bis(2-ethylhexanoate), diethylene glycol bis(2-ethylbutyrate), diethylene glycol bis(2-ethylhexanoate), dipropylene glycol bis(2-ethylbutyrate), triethylene glycol bis(2-ethylvalerate), tetraethylene glycol bis(2-ethylbutyrate), diethylene glycol didecanoate, triethylene glycol bis(n-heptanoate), tetraethylene glycol bis(n-heptanoate), triethylene glycol bis(2-ethylbutyrate), ethylene glycol bis(2-ethylbutyrate), 1,2-propylene glycol bis(2-ethylbutyrate), 1,3-propylene glycol bis(2-ethylbutyrate), 1,4-butylene glycol bis(2-ethylbutyrate), 1,2-butylene glycol bis(2-ethylbutyrate), and the like.

[0180] In addition, as the poly-carboxylic acid esters, mention may be made of ester compounds formed from dicarboxylic acids having 4 to 12 carbon atoms such as adipic acid, sebacic acid, 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.

[0181] Specific examples include dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, diisononyl adipate, heptyl nonyl adipate, dibutyl carbitol adipate, and mixed adipates. Additionally, it can also be oil-modified sebacic acid alkyd resin, etc. As the mixed adipates, adipates prepared from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms can be cited.

[0182] As the organic ester plasticizer, it is not limited to the complete esters of the above-mentioned various esters, and partial esters can also be used. For example, it can be a partial ester formed by a diol and a monobasic organic acid, or a partial ester formed by a dibasic organic acid and an alcohol. Specifically, triethylene glycol mono-2-ethylhexanoate, etc., can be cited.

[0183] Furthermore, it can be a partial ester formed by an alcohol having three or more hydroxyl groups, such as glycerol, and a monobasic organic acid. As the monobasic organic acid, monobasic organic acids having 3 to 24 carbon atoms, preferably 6 to 18 carbon atoms, can be cited. Specific examples of the partial ester formed by an alcohol having three or more hydroxyl groups and a monobasic organic acid include the monoester or diester of glycerol and stearic acid, the monoester or diester of glycerol and 2-ethylhexanoic acid, etc.

[0184] Among the above, triethylene glycol di-2-ethylhexanoate (3GO) is particularly preferably used as the organic ester plasticizer.

[0185] As the organic phosphorus plasticizer, phosphate esters such as tributoxyethyl phosphate, isodecyl phenyl phosphate, and triisopropyl phosphate can be cited.

[0186] As the polyalkylene glycol plasticizer, polyalkylene glycol compounds having a polyoxyalkylene structure can be cited. Specifically, polyhydric alcohol compounds such as diols, ester compounds of diols and monobasic or polybasic organic acids, ether compounds of monohydric or polyhydric alcohols and polyoxyalkylene, etc., can be cited. Here, as the diol, polyoxyalkylene glycol or its derivatives, etc., can be cited. As the polyoxyalkylene, polyoxyethylene, polyoxypropylene, polyoxybutylene, their random copolymers or block copolymers, etc., can be cited. The polyoxyalkylene compound can be a polyhydric alcohol compound as described above, can be an ester compound, can be an ether compound, or can be a compound other than these.

[0187] As the polyoxyalkylene compound, polyoxyalkylene or its derivatives can be cited. More specifically, polyoxyalkylene glycols composed of the above polyoxyalkylene, ether compounds of polyoxyalkylene and polyhydric alcohols, etc., can be cited. All of their terminals can be hydroxyl groups, but it can also be a derivative in which part or all of the hydrogen atoms of the terminal hydroxyl groups are substituted by an alkyl group or an acyl group. It should be noted that the number of carbon atoms of the alkyl group and the acyl group is not particularly limited, and it can be about 1 to 8, preferably 1 to 4.

[0188] Examples of the polyoxyalkylene glycol include polyoxyethylene glycol (polyoxyethylene glycol), polyoxypropylene glycol (polyoxypropylene glycol), poly(oxyethylene / oxypropylene) block copolymer, poly(oxyethylene / oxypropylene) random copolymer, and other polyoxyethylene polyoxypropylene glycols, and polytetramethylene glycol.

[0189] Examples of the ether compound formed from polyoxyalkylene and polyol include ether compounds formed from polyols such as glycerol, diglycerol, trimethylolpropane, erythritol, pentaerythritol, and bisphenol A and polyoxyalkylene. Specifically, examples include polyoxyethylene glycerol ether, polyoxypropylene glycerol ether, polyoxyethylene diglycerol ether, polyoxypropylene diglycerol ether, and polyoxyalkylene pentaerythritol ether. In addition, as derivatives in which part or all of the hydrogen atoms of the terminal hydroxyl groups are substituted with an alkyl group or an acyl group, derivatives in which part or all of the hydrogen atoms of the terminal hydroxyl groups of the above polyoxyalkylene glycols and ether compounds are substituted with an alkyl group or an acyl group can be cited. Specifically, examples include polyoxyethylene glycol monomethyl ether, polyoxyethylene glycol dimethyl ether, polyoxypropylene glycol monomethyl ether, polyoxypropylene glycol dimethyl ether, polyoxyethylene polyoxypropylene glycol monomethyl ether, polyoxyethylene polyoxypropylene glycol dimethyl ether, polyoxyethylene glycol monobutyl ether, polyoxypropylene glycol monobutyl ether, and polyoxyethylene polyoxypropylene monobutyl ether.

[0190] Among the above, the polyoxyalkylene-based compound preferably has a polyoxyethylene, polyoxypropylene, or polyoxyethylene polyoxypropylene structure, and among them, a compound having a polyoxypropylene or polyoxyethylene polyoxypropylene structure is more preferred. Specifically, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glycerol ether, polyoxypropylene diglycerol ether, or a derivative in which part of the hydrogen atoms of their terminal hydroxyl groups are substituted with an alkyl group is preferred.

[0191] Examples of the alcohol-based plasticizer include various polyols such as butanediol, hexanediol, trimethylolpropane, and pentaerythritol. Among them, trimethylolpropane is preferred.

[0192] The above plasticizers can be used alone or in combination of two or more. Among the above plasticizers, triethylene glycol - di - 2 - ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glycerol ether, polyoxypropylene diglycerol ether, or a derivative in which part of the hydrogen atoms of their terminal hydroxyl groups are substituted with an alkyl group is preferred, and triethylene glycol - di - 2 - ethylhexanoate (3GO) is more preferred.

[0193] The content of the plasticizer in the polyvinyl acetal resin layer is not particularly limited, and is preferably 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the polyvinyl acetal resin. If the content of the plasticizer is 10 parts by mass or more, the polyvinyl acetal resin layer becomes moderately soft, and the adhesiveness of the polyvinyl acetal resin layer and the penetration resistance of the laminated glass become good. Furthermore, the amount of thickness change also tends to be large.

[0194] On the other hand, if the content of the plasticizer is 100 parts by mass or less, separation of the plasticizer from the polyvinyl acetal resin layer can be prevented. In addition, it is also possible to prevent the amount of thickness change from becoming too large.

[0195] The above content of the plasticizer is more preferably 20 parts by mass or more, further preferably 25 parts by mass or more, still further preferably 30 parts by mass or more, and in addition, more preferably 70 parts by mass or less, further preferably 60 parts by mass or less, still further preferably 50 parts by mass or less.

[0196] In addition to the plasticizer, the polyvinyl acetal resin layer may appropriately contain known additives used in combination with the polyvinyl acetal resin. That is, the polyvinyl acetal resin layer may be composed of a polyvinyl acetal resin or composed of a polyvinyl acetal resin and a plasticizer, and in addition, additives other than the incorporated plasticizer may be contained as needed.

[0197] Specific examples of additives other than the plasticizer include: ultraviolet absorbers, infrared absorbers, antioxidants, light stabilizers, adhesion regulators, colorants (pigments or dyes), fluorescent brighteners, crystal nucleating agents, lubricants, etc.

[0198] <Colorant>

[0199] The above thermoplastic resin layer (A) may contain a colorant or may not contain a colorant. By using the above colorant, the laminated glass can be well colored to a desired hue. The above colorant may be used alone or in combination of two or more. The above thermoplastic resin layer (A) may contain only one kind of colorant, may contain two or more kinds, may contain three or more kinds, may contain ten or less kinds, and may also contain five or less kinds.

[0200] Examples of the above colorant include pigments and dyes. The above colorant may be a pigment, may be a dye, or may be both a pigment and a dye. In addition, there are colorants classified as both pigments and dyes.

[0201] Pigment: The above colorant may contain a pigment or may be a pigment. The above thermoplastic resin layer (A) may contain a pigment or may not contain a pigment. The above pigment may be used alone or in combination of two or more. The above thermoplastic resin layer (A) may contain only one kind of pigment, or may contain two or more kinds, may contain three or more kinds, may contain ten or less kinds, or may contain five or less kinds.

[0202] Examples of the above pigment include perylene compounds, Threne compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, violanthrone compounds, phthalocyanine compounds, Indanthrene compounds, indigo compounds, isoindolinone compounds, nickel complex compounds, methine compound dyes, methimine compounds, dioxazines, azo compounds, and carbon black.

[0203] When the above thermoplastic resin layer (A) contains a pigment, in 100% by mass of the above thermoplastic resin layer (A), the content of the above pigment is preferably 0.0001% by mass or more, more preferably 0.01% by mass or more, further preferably 0.02% by mass or more, preferably 0.15% by mass or less, and more preferably 0.12% by mass or less. When the content of the above pigment is above the above lower limit and below the above upper limit, the effects of the present invention can be more effectively exerted.

[0204] Dye: The above colorant may contain a dye or may be a dye. The above thermoplastic resin layer (A) may contain a dye or may not contain a dye. The above dye may be used alone or in combination of two or more. The above thermoplastic resin layer (A) may contain only one kind of dye, or may contain two or more kinds, may contain three or more kinds, may contain ten or less kinds, or may contain five or less kinds.

[0205] Examples of the above dye include perylene compounds, Threne compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, violanthrone compounds, phthalocyanine compounds, Indanthrene compounds, indigo compounds, isoindolinone compounds, nickel complex compounds, methine compounds, methimine compounds, dioxazines, and azo compounds.

[0206] When the above thermoplastic resin layer (A) contains a dye, in 100% by mass of the above thermoplastic resin layer (A), the content of the above dye is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, further preferably 0.001% by mass or more, preferably less than 0.015% by mass, and more preferably 0.01% by mass or less. If the content of the above dye is above the above lower limit and below the above upper limit (or less than the above upper limit), the effects of the present invention can be more effectively exerted.

[0207] When the above-mentioned thermoplastic resin layer (A) contains a colorant, in 100% by mass of the above-mentioned thermoplastic resin layer (A), the content of the above-mentioned colorant is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, further preferably 0.001% by mass or more, preferably 0.15% by mass or less, and more preferably 0.12% by mass or less. If the content of the above-mentioned colorant is above the above lower limit and below the above upper limit (or less than the above upper limit), the effects of the present invention can be more effectively exerted.

[0208] The thickness of the polyvinyl acetal resin layer is not particularly limited. For example, it is 100 μm or more and 2000 μm or less, preferably 150 μm or more and 1300 μm or less, and more preferably 200 μm or more and 1000 μm or less. By making the thickness of the polyvinyl acetal resin layer above the above lower limit value, the impact resistance can be improved, and it is also easy to ensure the adhesiveness to laminated glass members and the like. On the other hand, by setting it below the above upper limit value, it is possible to prevent the thickness of the laminated glass from becoming too thick.

[0209] 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, a part of the layers thereof may be a polyvinyl acetal resin layer, or all the layers may be a polyvinyl acetal resin layer. In addition, when the interlayer film for laminated glass has a multi-layer structure, it is preferable that any one of the outermost layers is a polyvinyl acetal resin layer, and more preferably both of the outermost layers are polyvinyl acetal resin layers. By making the two outermost layers be polyvinyl acetal resin layers, it is easy to suppress the remaining of air and indentations when press-bonded to laminated glass members and the like. On the other hand, in the case of a single-layer structure, the interlayer film for laminated glass may be composed of a single layer of the above-mentioned polyvinyl acetal resin layer.

[0210] When the interlayer film for laminated glass is, for example, a two-layer structure, any one of the layers may be a polyvinyl acetal resin layer, but it is preferable that both layers are polyvinyl acetal resin layers.

[0211] In addition, when the interlayer film for laminated glass is a three-layer structure having two outermost layers and a middle layer, any one of the two outermost layers may be a polyvinyl acetal resin layer, but it is preferable that the two outermost layers are polyvinyl acetal resin layers. At this time, the middle layer may be composed of a polyvinyl acetal resin layer or a substance other than the polyvinyl acetal resin layer.

[0212] In addition, the interlayer film for laminated glass may also have two outermost layers and two or more middle layers, having a structure of four or more layers. At this time, either of the two outermost layers may be a polyvinyl acetal resin layer, but preferably both are polyvinyl acetal resin layers. In addition, each middle layer may be composed of a polyvinyl acetal resin layer or a layer other than the polyvinyl acetal resin layer.

[0213] In addition, when the interlayer film for laminated glass of the present invention has a plurality of polyvinyl acetal resin layers, the polyvinyl acetal resin layers may have the same composition or different compositions. For example, among the plurality of polyvinyl acetal resin layers, the types and contents of the polyvinyl acetal resins constituting the layers may be the same as or different from each other.

[0214] In addition, when the interlayer film for laminated glass has a layer other than the polyvinyl acetal resin layer, such a layer only needs to be a thermoplastic resin layer other than the polyvinyl acetal resin layer. The type of the thermoplastic resin used in the thermoplastic resin layer other than the polyvinyl acetal resin layer is not particularly limited, and the thermoplastic resins listed as the thermoplastic resins that can be used in the above polyvinyl acetal resin layer can be appropriately selected and used. The types of resins that can be preferably used are also the same. Therefore, it is particularly preferred to use polyvinyl acetal resins.

[0215] In the interlayer film for laminated glass, the thickness of the polyvinyl acetal resin layer is not particularly limited, and it is preferably in a proportion of a certain amount or more in the total thickness of the interlayer film for laminated glass. Specifically, the proportion of the thickness of the polyvinyl acetal resin layer to the total thickness of the interlayer film for laminated glass may be, for example, a proportion of 0.1 or more and 1 or less, preferably 0.3 or more and 1 or less, more preferably 0.5 or more and 1 or less, and further preferably 0.75 or more and 1 or less. It should be noted that the thickness of the polyvinyl acetal resin layer here, when there are two or more polyvinyl acetal resin layers, is the total thickness thereof. By containing the polyvinyl acetal resin layer in a certain thickness proportion or more in the interlayer film for laminated glass, it is easy to suppress the remaining of air, indentation, and foaming at the peripheral part during pressing.

[0216] The thickness of each specific polyvinyl acetal resin layer is not particularly limited. For example, it is 50 μm or more and 1500 μm or less, preferably 100 μm or more and 1000 μm or less, more preferably 150 μm or more and 900 μm or less. By having a thickness of a certain amount or more, the polyvinyl acetal resin layer is easy to suppress the remaining of air and indentation during pressing. In addition, by setting the thickness to a certain amount or less, it is possible to prevent the interlayer film of laminated glass from becoming too thick.

[0217] The manufacturing method of the interlayer film for laminated glass is not particularly limited and can be manufactured by conventionally known methods. For example, it can be manufactured by extrusion molding, press molding, etc., and preferably by extrusion molding.

[0218] In addition, the interlayer film for laminated glass may have uneven shapes on one or both surfaces. The method for forming the uneven shapes is not particularly limited, and examples thereof include a lip indentation method, an indentation roll method, a calender roll method, etc.

[0219] <Laminated body>

[0220] The laminated body of the present invention includes the interlayer film for laminated glass of the present invention and a functional layer different from the interlayer film for laminated glass of the present invention. By using the interlayer film for laminated glass having the polyvinyl acetal resin layer of the present invention in the laminated body, when assembling the functional layer in laminated glass or the like, an autoclave process under high temperature and high pressure conditions is not required, and thus inactivation of the functional layer can be suppressed. The functional layer is preferably disposed between a pair of interlayer films for laminated glass of the present invention. However, the functional layer may also be disposed between the interlayer film for laminated glass of the present invention and an interlayer film for laminated glass other than the above-mentioned interlayer film for laminated glass of the present invention. In addition, the layer structure of the laminated body is not limited to the structure in which the functional layer is disposed between a pair of interlayer films for laminated glass, and various modes can be adopted as described later.

[0221] (Functional layer)

[0222] The functional layer used in the laminated body of the present invention is not particularly limited as long as it is a layer having a specified function. As the functional layer used in the laminated body of the present invention, for example, a functional film can be used. The functional film can be a dimming film, a display element film, or an optical film such as a polarizing film, a retardation film, an antireflection film, a heat ray reflection film, a visible light reflection film, a solar cell film, etc. In addition, the functional film can also be a film that imparts a sealing function to the laminated body. Moreover, a laminated body can also be used as a sealing material. In addition, a solar cell element can also be used as the functional layer.

[0223] In addition, among the above-mentioned functional films, the functional film is preferably a film having electronic components such as a dimming film and a display element film. If the film having electronic components is integrated by an autoclave under high temperature and high pressure conditions, its function is likely to deteriorate or inactivate. However, according to the present invention, it is not necessary to press-bond the interlayer film for laminated glass to the functional layer in the autoclave process under high temperature and high pressure conditions, and thus the functional layer can be assembled in the laminated body such as laminated glass without inactivation. Therefore, even a film having electronic components can be assembled in the laminated body in a practically usable manner.

[0224] In addition, for a dimming film or a display element film, if laminated glass having any one of them is assembled into various window glasses, window glasses with high added value can be provided. Therefore, in the present invention, it is preferable to use any one of them as a functional layer.

[0225] A dimming film is a film-like component 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 bonding surface of the dimming film with the thermoplastic resin layer becomes a resin material, and the bonding strength with respect to the polyvinyl acetal resin layer is likely to be high. The resin film used in the dimming element is not particularly limited, and examples thereof include polyester resin films such as PET films and PEN films, (meth)acrylic resin films, TAC films, PES resin films, and polyimide resin films. Among them, from the viewpoints of processability and the like, a polyester resin film is preferable, and a PET film is more preferable. In addition, a conductive layer constituting an electrode is provided on the surface of each of the two resin films on the side of the dimming layer.

[0226] The dimming layer is a layer that changes the visible light transmittance by switching the application and non-application of a voltage between the conductive layers of the two resin films. The dimming layer may be composed of a liquid crystal layer such as a polymer dispersed liquid crystal (PDLC), and the dimming film may be a PDLC film. In addition, the dimming film may also be an SPD (Suspended Particle Device) film, an electrochromic film, an electrophoretic film device, a GHLC (Guest-Host Liquid Crystal) film, or the like. Therefore, the dimming layer may be an SPD layer including a resin matrix and a dimming suspension dispersed in the resin matrix, or may be an electrochromic material layer. In addition, it may also be an electrophoretic layer including electrophoretic particles and a dispersant for dispersing the electrophoretic particles. In addition, it may also be a layer composed of a host molecule and a guest molecule.

[0227] A display element film is a film-like component having a display element. Examples of the display element film include a display element film including a resin film and a display element mounted on the resin film. The display element film may also be a film in which a display element is disposed between a pair of resin films. According to such a structure, when disposed between a pair of interlayer films for laminated glass and incorporated into the laminated glass, it can be bonded to the interlayer film for laminated glass with high adhesiveness. It should be noted that as the resin film used in the display element film, the resin films listed in the dimming film can be appropriately selected and used.

[0228] In addition, in the display element film, a conductive layer constituting an electrode may also be provided on the surface of the resin film on the side of the display element. Examples of the display element include an organic EL element, an LED display, a segment display, etc., and an organic EL element is preferable.

[0229] It should be noted that the functional film with electronic components is not limited to the above-mentioned display element film and dimming film, and can also be other functional films. However, the electronic components can be installed on the resin film in the same way as the display element film and the dimming film, and preferably in a manner where the electronic components are arranged between a pair of resin films.

[0230] By using a solar cell element as a functional layer, it is possible to provide laminated glass for a building-integrated photovoltaics (BIPV) device.

[0231] The solar cell element is not particularly limited as long as it is a solar cell element used in a building-integrated power generation device (BIPV). For example, crystalline or thin-film silicon-based solar cell elements can be cited; compound semiconductor-based solar cell elements such as CIS, CIGS, CdTe, and GaAs; organic solar cell elements such as dye-sensitized, organic thin-film, and perovskite solar cell elements, etc.

[0232] The laminate can be manufactured by, for example, thermocompression bonding the functional layer and the interlayer film for laminated glass. Additionally, when the laminate is incorporated into the laminated glass, thermocompression bonding can also be performed by first thermocompression bonding the functional layer and the interlayer film for laminated glass to form a laminate, and then pressing the laminate against the laminated glass component to form the laminated glass. Alternatively, the functional layer and the interlayer film for laminated glass before pressing can be arranged between the laminated glass components, and the functional layer and the interlayer film can be pressed together during the process of pressing the laminated glass component and the interlayer film for laminated glass.

[0233] <Laminated Glass>

[0234] The laminated glass of the present invention includes: a first laminated glass component, a second laminated glass component, and the interlayer film for laminated glass of the present invention or the laminate of the present invention disposed between the first laminated glass component and the second laminated glass component.

[0235] (First and Second Laminated Glass Components)

[0236] As the first laminated glass component and the second laminated glass component used in the laminated glass of the present invention, for example, glass plates can be cited. The glass plate can be either inorganic glass or organic glass, and inorganic glass is preferred. As the inorganic glass, there is no particular limitation, and examples include transparent glass, float plate glass, tempered glass, colored glass, polished plate glass, embossed glass, wired plate glass, UV-absorbing plate glass, IR-reflective plate glass, IR-absorbing plate glass, green glass, etc.

[0237] In addition, as the plexiglass, the plexiglass generally known as resin glass can be used, and examples thereof include polycarbonate plates, (meth)acrylic acid-based plates such as polymethyl methacrylate plates, acrylonitrile styrene copolymer plates, acrylonitrile butadiene styrene copolymer plates, polyester plates such as polyethylene terephthalate plates, fluorine-based resin plates, polyvinyl chloride plates, chlorinated polyvinyl chloride plates, polypropylene plates, polystyrene plates, polysulfone plates, epoxy resin plates, phenolic resin plates, unsaturated polyester resin plates, polyimide resin plates, and various other plexiglass plates. The organic resin plates can be appropriately subjected to surface treatment and the like.

[0238] The first laminated glass component and the second laminated glass component can be made of the same type of material as each other, or can be made of different materials. For example, one can be inorganic glass and the other can be organic glass, but it is preferred that both the first laminated glass component and the second laminated glass component are inorganic glass or organic glass.

[0239] In addition, the thickness of each glass plate used as the first laminated glass component and the second laminated glass component is not particularly limited, for example, it is about 0.1 to 15 mm, preferably 0.5 to 5 mm. The thicknesses of the respective glass plates can be the same as each other or different.

[0240] The laminated glass component can be composed of the glass plate itself, or other components can be mounted on the glass plate. The laminated glass component can be provided with functional components on the glass plate to endow various functions.

[0241] Other components can be, for example, as long as they are components constituting electronic devices, optical components, etc., and are preferably components constituting a display device. As the display device, it can be a liquid crystal display device, an organic EL display device, an LED display device, a segment display device, etc. Among these, the display device is preferably a liquid crystal display device.

[0242] The display device can be, for example, a display panel having a glass plate as a substrate, and a display layer such as a liquid crystal layer or an organic EL layer, a light-emitting element, etc. provided on the substrate, but the glass plate serving as the substrate of the display panel can also be used as the laminated glass component.

[0243] In addition, sometimes a conductive layer, an antireflection layer, a hard coating, and other functional layers constituting a functional film, an electrode, a sensor, etc. described later are laminated on the glass plate, but the laminated glass component can also be a glass plate laminated with such a functional film or functional layer.

[0244] Therefore, the bonding surface of the laminated glass intermediate film directly laminated with the laminated glass intermediate film can be the glass plate itself or the surface of the functional film or functional layer.

[0245] When two or more interlayers for laminated glass are provided in the laminate, as described above, it is preferable that all the interlayers for laminated glass are the interlayers for laminated glass of the present invention, but a part of the interlayers for laminated glass may be a film other than the interlayer for laminated glass of the present invention. In addition, other layers such as an adhesive layer may be appropriately provided between the functional layer and the interlayer for laminated glass.

[0246] (Layer structure of laminated glass)

[0247] Next, with reference to the drawings, the layer structure of the laminated glass will be described in detail with reference to the embodiments. As Figure 1 shown, in the first embodiment of the present invention, the laminated glass 1A is a laminated glass in which one interlayer for laminated glass (polyvinyl acetal resin layer) 10 is provided between a first laminated glass member 20 and a second laminated glass member 30. In the laminated glass 1A, the interlayer for laminated glass 10 is bonded to both the first laminated glass member 20 and the second laminated glass member 30, thereby joining them.

[0248] In the first embodiment, as described above, at least one of the first laminated glass member 20 and the second laminated glass member 30 may be provided with other components. Specifically, functional components constituting electronic devices such as display devices, optical components, etc. may be installed, or the above-mentioned functional films, functional layers, etc. may be laminated.

[0249] Among them, it is preferable that at least one of the first laminated glass member 20 and the second laminated glass member 30 is provided with components constituting a display device, particularly a liquid crystal display device. That is, at least one of the first laminated glass member 20 and the second laminated glass member 30 may be a glass plate constituting a display device, and a display device having at least one of the first laminated glass member 20 and the second laminated glass member 30 as a substrate may be provided in the laminated glass 1A.

[0250] In the first embodiment, by using an interlayer containing the polyvinyl acetal resin of the present invention as the interlayer for laminated glass 10, even without passing through the autoclave process under high temperature and high pressure conditions to integrate the first laminated glass member 20, the second laminated glass member 30, and the interlayer for laminated glass 10, it is possible to suppress appearance defects caused by residual air and residual indentation during crimping. On the other hand, even if a functional component is provided in one of the first laminated glass member 20 and the second laminated glass member 30, it is possible to perform crimping and integration without passing through the autoclave process under high temperature and high pressure conditions, so that the functional component installed in the laminated glass 1A can be prevented from deteriorating or deactivating.

[0251] In addition, as another preferred embodiment, an interlayer film for laminated glass composed of a plurality of thermoplastic resin layers may also be provided between the first laminated glass component and the second laminated glass component. When the interlayer film for laminated glass is composed of a plurality of thermoplastic resin layers, at least one of the plurality of thermoplastic resin layers may be the polyvinyl acetal resin layer described above, and preferably all of the plurality of thermoplastic resin layers are the polyvinyl acetal resin layers described above. When a plurality of thermoplastic resin layers are provided, it is preferable that all of the thermoplastic resin layers are the above-mentioned polyvinyl acetal resin layers. Thus, even without passing through the autoclave process under high temperature and high pressure conditions to integrate the first laminated glass component, the second laminated glass component, and the interlayer film for laminated glass, it is easy to appropriately suppress appearance defects caused by foaming and the like due to residual air, residual indentation during crimping, and use in a high-temperature environment.

[0252] An embodiment of the laminated glass in the case where a plurality of thermoplastic resin layers are provided is shown as the second embodiment in Figure 2 . As Figure 2 shown, in the laminated glass 1B of the second embodiment, a pair of interlayer films 10 for laminated glass are provided between the first laminated glass component 20 and the second laminated glass component 30, and a functional layer 40 is also provided between the pair of interlayer films 10 for laminated glass. That is, in the laminated glass 1B of the second embodiment, a laminate 50 in which the functional layer 40 is provided between the pair of interlayer films 10 for laminated glass is provided between the first laminated glass component 20 and the second laminated glass component 30. The pair of interlayer films 10 for laminated glass are preferably both the above-mentioned polyvinyl acetal resin layers.

[0253] In the laminated glass 1B, one interlayer film 10 for laminated glass is bonded to both the first laminated glass component 20 and the functional layer 40 to join them, and the other interlayer film 10 for laminated glass is bonded to both the second laminated glass component 30 and the functional layer 40 to join them. Thus, the first laminated glass component 20 and the second laminated glass component 30 are integrated with the functional layer 40 through the interlayer film 10 for laminated glass which is a polyvinyl acetal resin layer.

[0254] In the second embodiment, the laminated glass 1B may also be integrated through the autoclave process under high temperature and high pressure conditions. However, even without passing through the autoclave process under high temperature and high pressure conditions, by using the interlayer film 10 for laminated glass having the above-mentioned polyvinyl acetal resin layer, it is possible to prevent appearance defects caused by foaming and the like due to residual air, residual indentation during crimping, and use in a high-temperature environment. In addition, by integrating the laminated glass 1B at a low temperature, it is also possible to prevent the functional layer 40 from deteriorating or deactivating.

[0255] It should be noted that in the second embodiment, a method of providing two interlayers for laminated glass 10 and one functional layer 40 in the laminate is shown. However, three or more interlayers for laminated glass and two or more functional layers may also be provided in the laminate. In this case, in the first laminated glass and the second laminated glass, the interlayers for laminated glass and the functional layers may be alternately arranged. Moreover, the interlayers for laminated glass can be arranged at the positions closest to the first laminated glass component and the second laminated glass component.

[0256] For example, in the case of providing three interlayers for laminated glass 10 and two functional layers, they can be arranged in the order of the first laminated glass component / interlayer for laminated glass / functional layer / interlayer for laminated glass / functional layer / interlayer for laminated glass / second laminated glass component.

[0257] In addition, in the case of providing three or more interlayers for laminated glass, the above-mentioned polyvinyl acetal resin layer can be used as each interlayer for laminated glass.

[0258] It should be noted that in the case of providing a plurality of interlayers for laminated glass in the laminated glass, the structures of the respective interlayers for laminated glass may be the same or different.

[0259] (Manufacturing method of laminated glass)

[0260] The laminated glass of the present invention can be manufactured by the following manufacturing method: at least an interlayer for laminated glass or a laminate is arranged between the first laminated glass component and the second laminated glass component, and they are pressed and bonded to obtain the laminated glass. In addition, the components constituting the laminate can also be prepared, and the components constituting the laminate are arranged between the first laminated glass component and the second laminated glass component, and they are pressed and bonded to produce the laminated glass assembled with the laminate.

[0261] In the above manufacturing method, first, the first laminated glass component, the second laminated glass component, and the components to be arranged between the first laminated glass component and the second laminated glass component (such as an interlayer for laminated glass or a laminate) are prepared.

[0262] Here, the components arranged between the first laminated glass component and the second laminated glass component can be appropriately selected according to the structure of the obtained laminated glass. For example, in the first embodiment, only the interlayer for laminated glass itself needs to be prepared. In addition, for example, in the second embodiment, only the laminate composed of two interlayers for laminated glass and one functional layer needs to be prepared.

[0263] In addition, as described above, in laminated glass, at least one of the first laminated glass member and the second laminated glass member is sometimes provided with a functional member, and the functional member can be installed on the laminated glass member before integration with the laminated glass. Therefore, in the above manufacturing method, at least one of the first laminated glass member and the second laminated glass member may be prepared as a laminated glass member provided with a functional member. For example, as described above, when the laminated glass member constitutes the substrate of the display device, at least one of the first laminated glass member and the second laminated glass member may be prepared as the display device.

[0264] In this manufacturing method, as described above, an interlayer film or laminate for laminated glass may be disposed between the first laminated glass member and the second laminated glass member, and the laminated glass may be obtained by bonding and integrating them. Alternatively, a member constituting the laminate may be disposed between the first laminated glass member and the second laminated glass member, and the laminated glass assembled with the laminate may be obtained by bonding and integrating them.

[0265] Here, the interlayer film or laminate for laminated glass may be disposed according to the layer structure of the obtained laminated glass. For example, in the second embodiment, it may be disposed between the first and second laminated glass members in the order of the interlayer film for laminated glass, the functional layer, and the interlayer film for laminated glass.

[0266] The above bonding may be performed by a vacuum bag, by an autoclave under low-temperature conditions, or by a press other than these. Among them, it is preferably performed in a vacuum bag. In addition, before performing the above bonding, temporary crimping may be performed using a rubber roller or the like.

[0267] In this manufacturing method, the above bonding needs to be performed under low-temperature conditions. Specifically, crimping may be performed at a temperature of 110°C or lower. In addition, the above bonding is preferably performed under low temperature and low pressure. Specifically, it is preferably performed at a temperature of 110°C or lower and a pressure of 1.0 MPa or lower. Thus, by performing the bonding under low-temperature and low-pressure conditions, it is possible to prevent the functional layer and the functional members (such as display devices) installed on the first laminated glass member and the second laminated glass member from deteriorating and deactivating.

[0268] From the viewpoint of more reliably preventing the deterioration and deactivation of the functional members, the temperature during bonding is preferably 100°C or lower, and from the viewpoint of preventing the generation of residual air, residual indentations, and foaming, it is preferably 60°C or higher, more preferably 70°C or higher.

[0269] In addition, from the perspective of more reliably preventing the deterioration and inactivation of functional components, the pressure during lamination is preferably 1.2 MPa or less. In addition, in the case of performing under negative pressure as in the case of using a vacuum bag, for example, it can be 0.095 MPa or less, preferably 0.08 MPa or less, and more preferably 0.06 MPa or less.

[0270] The lower limit of the pressure during lamination is not particularly limited. For example, in the case of performing under pressure such as in an autoclave, it is preferably 0.5 MPa or more, and more preferably 0.7 MPa or more. In addition, in the case of performing under negative pressure as in the case of using a vacuum bag, it is preferably 0.001 MPa or more, and more preferably 0.005 MPa or more.

[0271] In addition, the time for lamination at the above temperature and pressure is not particularly limited. For example, it is 5 to 120 minutes, preferably 10 to 60 minutes.

[0272] The laminated glass of the present invention is not particularly limited and can be used for various purposes. For example, the laminated glass of the present invention is used for various transportation means such as vehicles (e.g., automobiles, trams), ships, airplanes, or various buildings such as buildings, apartments, single-family houses, halls, gymnasiums, or as window glass for machine tools such as cutting and grinding machines, construction machinery such as excavators and cranes, or partitions inside various transportation means and various buildings. Among them, vehicle uses such as automobiles are preferred, and it is preferably used for vehicle window glass.

[0273] In addition, for example, when the laminated glass of the present invention constitutes a display device from laminated glass components, it can be used for various display purposes. As display purposes, the above-mentioned window glass and partition can be used as displays.

[0274] In addition, the laminated glass can also be used as a cover glass for various displays, etc. For example, it can also be applied to in-vehicle displays, etc.

[0275] Examples

[0276] The present invention will be described in more detail by way of examples, but the present invention is not limited by any of these examples. It should be noted that the measurement methods and evaluation methods for each physical property value in the present invention are as described below.

[0277] < 13 Measurement of C-NMR spectrum

[0278] Using a nuclear magnetic resonance (NMR) apparatus (manufactured by Bruker Corporation, trade name "AVANCE III HD"), implemented using a spectrometer of 400 MHz 1313C-NMR measurement. PVB was dissolved in deuterated dimethyl sulfoxide (DMSO) to a concentration of 12% by mass. The NMR measurement was carried out by the inverse gated decoupling method at a temperature of 80 °C. The horizontal axis represents the chemical shift in ppm, and the reference for the chemical shift is 39.5 ppm for DMSO-d6. 13 The range of the integral value of the peak of the methylene C atom or methine C atom at the above position attributed to the above structural unit in the 13C-NMR spectrum is shown in Table 1.

[0279] Table 1

[0280]

[0281] <Degree of acetalization, hydroxyl value, and degree of acetylation>

[0282] · Determination of the content (mass %) of the ethylene group bonded to the hydroxyl group

[0283] Accurately weigh 0.4 g of the sample into a 200 mL stoppered Erlenmeyer flask. After adding 10.0 mL of a pyridine-acetic anhydride mixture to the sample, heat it on a water bath at a bath temperature of 90 °C and irradiate it with ultrasonic waves to dissolve the sample in the pyridine-acetic anhydride mixture. Install a reflux condenser on the Erlenmeyer flask and heat it under reflux on the water bath for 120 minutes. After the reaction, wash the condenser with 25 mL of pyridine and cool the sample solution after the reaction to room temperature. Add 20 mL of 1,2-dichloroethane to the cooled sample solution, mix it by shaking, then further add 50 mL of water, mix it by shaking, and let it stand at room temperature for 30 minutes. Then, perform potentiometric titration on the sample solution with a 0.5 mol / L (0.5 N) sodium hydroxide solution. Perform a blank test in the same manner except without using the sample, and calculate the content (mass %) of the ethylene group bonded to the hydroxyl group in the sample based on the following formula.

[0284] [Equation 1]

[0285]

[0286] In the formula, W OH is the content (mass %) of the ethylene group bonded to the hydroxyl group, V BL is the volume (mL) of the sodium hydroxide solution used in the blank test, V sp is the volume (mL) of the sodium hydroxide solution used in the titration of the sample, f NaOH is the factor of the 0.5 mol / L sodium hydroxide solution actually used in the potentiometric titration, and m is the mass (g) of the sample.

[0287] · Determination of the content (mass %) of the ethylene group bonded to the acetyl group

[0288] Precisely weigh 0.4 g of the test sample into a 200 mL stoppered Erlenmeyer flask. After adding 100.0 mL of ethanol to the test sample, heat it on a water bath at a bath temperature of 90 °C and irradiate with ultrasonic waves to dissolve the test sample in ethanol. While shaking and mixing the Erlenmeyer flask, add 10.0 mL of 0.2 mol / L (0.2 N) sodium hydroxide. Attach a reflux condenser to the Erlenmeyer flask and heat under reflux in the water bath for 60 minutes. After the reaction, wash the condenser with 25 mL of ethanol and cool the resulting test sample solution to room temperature. Add 10.0 mL of 0.2 mol / L (0.2 N) hydrochloric acid to the cooled test sample solution, shake and mix well, and let it stand at room temperature for 30 minutes. Then, perform potentiometric titration of the test sample solution with a 0.1 mol / L (0.1 N) sodium hydroxide solution. Conduct a blank test in the same manner except without using the test sample, and calculate the content (mass %) of the ethylidene group bonded to the acetyl group in the test sample based on the following formula.

[0289] [Equation 2]

[0290]

[0291] In the formula, W Ac is the content (mass %) of the ethylidene group bonded to the acetyl group, V BL is the volume (mL) of the sodium hydroxide solution used in the blank test, V sp is the volume (mL) of the sodium hydroxide solution used in the titration of the test sample, f NaOH is the factor of the 0.1 mol / L sodium hydroxide solution actually used in the potentiometric titration, and m is the mass (g) of the test sample.

[0292] ·Determination of the content (mass %) of the ethylidene group bonded to the butyraldehyde group

[0293] Based on the content (mass %) of the ethylidene group bonded to the hydroxyl group and the content (mass %) of the ethylidene group bonded to the acetyl group obtained by the above method, the content (mass %) of the ethylidene group bonded to the butyraldehyde group was calculated based on the following formula.

[0294] [Equation 3]

[0295] W Bu = 100 - (W OH + W Ac )

[0296] In the formula, W Bu is the content (mass %) of the ethylidene group bonded to the butyraldehyde group, W OH is the content (mass %) of the ethylidene group bonded to the hydroxyl group, and W Ac is the content (mass %) of the ethylidene group bonded to the acetyl group.

[0297] ·Amount of hydroxyl group, degree of acetylation, degree of acetalization (degree of butyralization)

[0298] Using the ethylene group content bonded to the hydroxyl group, the ethylene group content bonded to the acetyl group, and the ethylene group content bonded to the butyral group obtained by the above method, calculate the hydroxyl group amount (mol%), the degree of acetylation (mol%), and the degree of acetalization (mol%) based on the following formula.

[0299] [Equation 4]

[0300]

[0301] [Equation 5]

[0302]

[0303] [Equation 6]

[0304]

[0305] <Weight-average molecular weight>

[0306] Dissolve the thermoplastic resins used in the examples and comparative examples in an N-methyl-2-pyrrolidone solution containing 10 mM lithium bromide at a concentration of 0.05% by mass. After filtering using a syringe filter (manufactured by Merck, Millex-LH 0.45 μm), measure the molecular weight using gel permeation chromatography (manufactured by Waters, e2690). Calculate the number-average molecular weight (Mn) and the weight-average molecular weight (Mw) using the molecular weight calibration curve prepared from a monodisperse polystyrene standard sample, and also determine the molecular weight distribution (Mw / Mn). In addition, use a Shodex GPC KF-806L column (manufactured by Showa Denko K.K.) and use an N-methyl-2-pyrrolidone solution added with lithium bromide to a concentration of 10 mM as the eluent.

[0307] <Amount of thickness change during compression creep test>

[0308] Cut out the interlayer films for laminated glass of each example and comparative example according to the method described in the instruction manual, and prepare specimens with a diameter of 8 mm. Using the prepared specimens, determine the amount of thickness change according to the method described in the instruction manual.

[0309] <Residual air and residual indentation after lamination>

[0310] Place the obtained laminated glass on a dark screen and visually evaluate the transparency of the laminated glass according to the following three grades.

[0311] A: Entire surface is transparent

[0312] B: Partially opaque

[0313] C: Mostly opaque

[0314] It should be noted that for reference, Figure 3 (a) shows an example of laminated glass disposed on a dark screen and evaluated as "A", Figure 3 (b) shows an example of laminated glass disposed on a dark screen and evaluated as "B", Figure 3 (c) shows an example of laminated glass disposed on a dark screen and evaluated as "C".

[0315] <Peripheral foaming>

[0316] The obtained laminated glass is disposed on a dark screen, and the presence or absence of foaming at the end is evaluated visually according to the following three grades.

[0317] A: No peripheral foaming

[0318] B: Slight peripheral foaming

[0319] C: Many peripheral foaming

[0320] [Example 1]

[0321] (Synthesis of polyvinyl butyral resin)

[0322] 1800 mL of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 98 mol%) are added to a reactor equipped with a stirring device, and dissolved by heating with stirring to obtain a polyvinyl alcohol solution. Then, 30% hydrochloric acid as a catalyst is added to this solution to make the hydrochloric acid concentration 0.2% by mass. After adjusting the temperature to 15°C, n-butyraldehyde is added while stirring so as to be 10 mol%. Then, n-butyraldehyde is added so as to be 60 mol%, and as a result, white granular polyvinyl butyral resin precipitates. Ten minutes after precipitation, 30% hydrochloric acid is added so that the hydrochloric acid concentration becomes 1.8% by mass, and then the temperature is raised to 52°C, and it is cured for 2 hours at a curing temperature of 52°C.

[0323] Next, after cooling and neutralizing the solution, the polyvinyl butyral resin is washed with water and dried, thereby obtaining Resin 1 (polyvinyl butyral resin, hydroxyl amount 27.4 mol%, acetalization degree 70.7 mol%, acetylation degree 1.9 mol%, degree of polymerization 1700).

[0324] (Production of laminated glass)

[0325] 40 parts by mass of a plasticizer (triethylene glycol - di-2-ethylhexanoate: 3GO) is mixed with 100 parts by mass of the polyvinyl butyral resin to obtain a resin composition. Using a hydraulic press and a spacer with a thickness of 800 μm, an interlayer film for laminated glass composed of a single layer of a polyvinyl butyral resin layer with a film thickness of 800 μm is produced. In addition, two pieces of 2.5 mm transparent glass are prepared.

[0326] Next, an interlayer film for laminated glass is overlapped on a transparent glass, and another transparent glass is further overlapped on the interlayer film for laminated glass to obtain a laminate. The obtained laminate is placed in a rubber bag used as a vacuum bag and degassed for 5 minutes under a vacuum degree of 1325 Pa or less. Next, the laminate is placed in an oven in a degassed state and gradually heated to a glass surface temperature of 90 °C. After the glass surface temperature reaches 90 °C, it is held at 90 °C for 15 minutes for formal pressing, and then cooled to 35 °C. Next, the pressure is restored to normal pressure to obtain the laminated glass of Example 1.

[0327] [Example 2]

[0328] (Synthesis of polyvinyl acetal resin)

[0329] 1800 mL of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 98 mol%) are added to a reactor equipped with a stirring device, and heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Next, 30% hydrochloric acid as a catalyst is added to this solution to make the hydrochloric acid concentration 0.2% by mass. After adjusting the temperature to 15 °C, n-butyraldehyde is added while stirring to make it 10 mol%. Then, n-butyraldehyde is added to make it 60 mol%, and as a result, white granular polyvinyl butyral resin is precipitated. Ten minutes after precipitation, 30% hydrochloric acid is added to make the hydrochloric acid concentration 1.8% by mass, and then the temperature is raised to 53 °C and cured at a curing temperature of 53 °C for 2 hours.

[0330] Next, after the solution is cooled and neutralized, the polyvinyl butyral resin is washed with water and dried to obtain Resin 2 (polyvinyl butyral resin, hydroxyl amount 27.3 mol%, acetalization degree 71.9 mol%, acetylation degree 0.9 mol%, degree of polymerization 1700).

[0331] (Fabrication of laminated glass)

[0332] Except for changing the amount and type of the resin used and the amount of the plasticizer as described in Table 2, it is carried out in the same manner as in Example 1.

[0333] [Example 3]

[0334] (Synthesis of polyvinyl acetal resin)

[0335] In a reactor equipped with a stirring device, 1800 mL of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) were added, and the mixture was heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Then, 30% hydrochloric acid as a catalyst was added to this solution to make the hydrochloric acid concentration 0.2% by mass. After adjusting the temperature to 15°C, n-butyraldehyde was added while stirring to make it 10 mol%. Then, n-butyraldehyde was added to make it 60 mol%, and as a result, white granular polyvinyl butyral resin was precipitated. Ten minutes after precipitation, 30% hydrochloric acid was added to make the hydrochloric acid concentration 1.8% by mass, and then the temperature was raised to 53°C, and it was cured at a curing temperature of 53°C for 2 hours.

[0336] Next, after cooling and neutralizing the solution, the polyvinyl butyral resin was washed with water and dried to obtain Resin 3 (polyvinyl butyral resin, hydroxyl amount 27.5 mol%, degree of acetalization 71.5 mol%, degree of acetylation 1.0 mol%, degree of polymerization 1700).

[0337] (Fabrication of laminated glass)

[0338] Except for changing the amount and type of the resin used and the amount of the plasticizer as described in Table 2, it was carried out in the same manner as in Example 1.

[0339] [Example 4]

[0340] (Synthesis of polyvinyl acetal resin)

[0341] In a reactor equipped with a stirring device, 1800 mL of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) were added, and the mixture was heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Then, 30% hydrochloric acid as a catalyst was added to this solution to make the hydrochloric acid concentration 0.2% by mass. After adjusting the temperature to 15°C, n-butyraldehyde was added while stirring to make it 10 mol%. Then, n-butyraldehyde was added to make it 60 mol%, and as a result, white granular polyvinyl butyral resin was precipitated. Ten minutes after precipitation, 30% hydrochloric acid was added to make the hydrochloric acid concentration 1.8% by mass, and then the temperature was raised to 57.5°C, and it was cured at a curing temperature of 57.5°C for 2 hours.

[0342] Next, after cooling and neutralizing the solution, the polyvinyl butyral resin was washed with water and dried to obtain Resin 4 (polyvinyl butyral resin, hydroxyl amount 28.2 mol%, degree of acetalization 71.0 mol%, degree of acetylation 0.8 mol%, degree of polymerization 1700).

[0343] (Fabrication of laminated glass)

[0344] Except for changing the amount and type of the resin used and the amount of the plasticizer as described in Table 2, it was carried out in the same manner as in Example 1.

[0345] [Example 5]

[0346] (Synthesis of polyvinyl acetal resin)

[0347] 1800 mL of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization: 1700, degree of saponification: 99 mol%) were added to a reactor equipped with a stirring device, and heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Then, 30% hydrochloric acid as a catalyst was added to this solution to make the hydrochloric acid concentration 0.2% by mass. After adjusting the temperature to 15°C, n-butyraldehyde was added while stirring to make it 10 mol%. Then, n-butyraldehyde was added to make it 60 mol%, and as a result, white granular polyvinyl butyral resin was precipitated. Ten minutes after the precipitation, 30% hydrochloric acid was added to make the hydrochloric acid concentration 1.8% by mass, and then the temperature was raised to 52.5°C, and it was cured at a curing temperature of 52.5°C for 2 hours.

[0348] Then, after cooling and neutralizing the solution, the polyvinyl butyral resin was washed with water and dried to obtain Resin 5 (polyvinyl butyral resin, hydroxyl amount: 28.6 mol%, degree of acetalization: 70.9 mol%, degree of acetylation: 0.6 mol%, degree of polymerization: 1700).

[0349] (Production of laminated glass)

[0350] Except for changing the amount and type of the resin used and the amount of the plasticizer as described in Table 2, it was carried out in the same manner as in Example 1.

[0351] [Comparative Example 1]

[0352] (Synthesis of polyvinyl acetal resin)

[0353] In a reactor equipped with a stirring device, 1800 mL of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) were added, and the mixture was heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Subsequently, 30% hydrochloric acid as a catalyst was added to this solution to make the hydrochloric acid concentration 0.2% by mass. After adjusting the temperature to 15°C, n-butyraldehyde was added while stirring to make it 10 mol%. Then, n-butyraldehyde was added to make it 60 mol%, and as a result, white granular polyvinyl butyral resin was precipitated. Ten minutes after precipitation, 30% hydrochloric acid was added to make the hydrochloric acid concentration 1.8% by mass, and then the temperature was raised to 66°C, and it was cured at a curing temperature of 66°C for 2 hours. Then, after cooling and neutralizing the solution, the polyvinyl butyral resin was washed with water and dried, whereby the polyvinyl acetal resin of Comparative Example 1 (polyvinyl butyral resin, hydroxyl group amount 27.2 mol%, acetalization degree 72.3 mol%, acetylation degree 0.6 mol%, degree of polymerization 1700) was obtained.

[0354] (Fabrication of laminated glass)

[0355] Except for changing the amount and type of the resin used and the amount of the plasticizer as described in Table 2, it was carried out in the same manner as in Example 1.

[0356] [Comparative Example 2]

[0357] (Synthesis of polyvinyl acetal resin)

[0358] In a reactor equipped with a stirring device, 1800 mL of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 98 mol%) were added, and the mixture was heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Subsequently, 30% hydrochloric acid as a catalyst was added to this solution to make the hydrochloric acid concentration 0.2% by mass. After adjusting the temperature to 15°C, n-butyraldehyde was added while stirring to make it 10 mol%. Then, n-butyraldehyde was added to make it 60 mol%, and as a result, white granular polyvinyl butyral resin was precipitated. Ten minutes after precipitation, 30% hydrochloric acid was added to make the hydrochloric acid concentration 1.8% by mass, and then the temperature was raised to 66°C, and it was cured at a curing temperature of 66°C for 2 hours. Then, after cooling and neutralizing the solution, the polyvinyl butyral resin was washed with water and dried, whereby the polyvinyl acetal resin of Comparative Example 2 (polyvinyl butyral resin, hydroxyl group amount 27.4 mol%, acetalization degree 71.8 mol%, acetylation degree 0.8 mol%, degree of polymerization 1700) was obtained.

[0359] (Fabrication of laminated glass)

[0360] Except for changing the amount and type of the resin used and the amount of the plasticizer as described in Table 2, it was carried out in the same manner as in Example 1.

[0361] The plasticizers used in the examples and comparative examples are as described below.

[0362] 3GO: Triethylene glycol - di - 2 - ethylhexanoate

[0363] The 13 C - NMR spectrum of the polyvinyl acetal resin of Example 2 is shown in Figure 4 , and the 13 C - NMR spectrum of the polyvinyl acetal resin of Comparative Example 1 is shown in Figure 5 . In addition, the evaluation results of Examples 1 - 5 and Comparative Examples 1 - 2 are shown in Table 2.

[0364] Table 2

[0365]

[0366] ※1 I(h)'2 = (I(h)'1 + I(h)'2) - I(I)' * (I(e)' / I(d)')

[0367] ※2 R = [(I(f)' + I(g)' + I(h)'2) / (I(f)' + I(g)' + I(h)'2 + I(i)' + I(j)' + I(k)')]

[0368] (Examples 6 - 8)

[0369] As described in Table 3, the amounts and types of the resins used and the amount of the plasticizer were changed, and further the following pigments were contained. Except for this, it was carried out in the same manner as in Example 1.

[0370] Example 6:

[0371] Phthalocyanine pigment (P.B.15 - 1): An amount of 0.0142% by mass in the obtained resin layer

[0372] Perylene pigment (P.R.149): An amount of 0.0030% by mass in the obtained resin layer

[0373] Phthalocyanine pigment (P.G.7): An amount of 0.0015% by mass in the obtained resin layer

[0374] Carbon black pigment (P.Bk.7): An amount of 0.0300% by mass in the obtained resin layer

[0375] Example 7:

[0376] Phthalocyanine pigment (P.B.15 - 1): An amount of 0.0148% by mass in the obtained resin layer

[0377] Perylene-based pigment (P.R.149): Amount of 0.0054% by mass in the obtained resin layer

[0378] Phthalocyanine-based pigment (P.G.7): Amount of 0.0060% by mass in the obtained resin layer

[0379] Carbon black-based pigment (P.Bk.7): Amount of 0.0280% by mass in the obtained resin layer

[0380] Example 8:

[0381] Phthalocyanine-based pigment (P.B.15-1): Amount of 0.0159% by mass in the obtained resin layer

[0382] Perylene-based pigment (P.R.149): Amount of 0.0062% by mass in the obtained resin layer

[0383] Phthalocyanine-based pigment (P.G.7): Amount of 0.0020% by mass in the obtained resin layer

[0384] Carbon black-based pigment (P.Bk.7): Amount of 0.0160% by mass in the obtained resin layer

[0385] Table 3

[0386]

[0387] ※1 I(h)'2 = (I(h)'1 + I(h)'2) - I(I)' * (I(e)' / I(d)')

[0388] ※2 R = [(I(f)' + I(g)' + I(h)'2) / (I(f)' + I(g)' + I(h)'2 + I(i)' + I(j)' + I(k)')]

[0389] The laminated glass of Examples 1 to 5 above was produced using a polyvinyl butyral resin that satisfies the above formula (1) and has an acetalization degree of 65 mol% or more and less than 75 mol%. As a result, although the bonding conditions were low temperature and low pressure, the residual amount of air and the residual indentation during bonding were small, and the laminated glass had high transparency. In addition, almost no foaming occurred in the peripheral portion of the interlayer film for laminated glass. Furthermore, the film-forming property of the interlayer film for laminated glass was good.

[0390] In contrast, the laminated glass of Comparative Examples 1 and 2 was produced using a polyvinyl butyral resin that does not satisfy the above formula (1), so there was a lot of residual air and indentation during bonding. As a result, the laminated glass had poor transparency.

[0391] Explanation of reference numerals

[0392] 1A, 2B laminated glass

[0393] 10 Interlayer film for laminated glass (polyvinyl acetal resin layer)

[0394] 20 First laminated glass component

[0395] 30 Second laminated glass component

[0396] 40 Functional layer

[0397] 50 Laminate.

Claims

1. A polyvinyl acetal resin, which contains a structural unit (a) represented by the following formula (a), a structural unit (b) represented by the following formula (b), and a structural unit (c) represented by the following formula (c), In will pass 13 C-NMR nuclear magnetic resonance measurement 13 When the integral value of the peak of the methylene C atom at the (a)' position of the structural unit (a) in the C-NMR spectrum is denoted as I(a)', the integral value of the peak of the methylene C atom at the (b)' position of the structural unit (b) is denoted as I(b)', and the integral value of the peak of the methylene C atom at the (c)' position of the structural unit (c) is denoted as I(c)', the following formula (1) is satisfied: The degree of acetalization of the polyvinyl acetal resin is 65 mol% or more and less than 75 mol%, I(a)’ / (I(b)’ +I(c)’ )<0.30 (1) R in formula (b) and formula (c) 1 , R 2 and R 3 are each hydrogen or a hydrocarbon group having 1 or more and 9 or less carbon atoms.

2. The polyvinyl acetal resin according to claim 1, which contains a structural unit (d) represented by the following formula (d) and a structural unit (e) represented by the following formula (e), In the case of using the 13 C-NMR nuclear magnetic resonance measurement result, 13 when the integral value of the peak of the methine C atom at the (d)' position attributed to the structural unit (d) in the C-NMR spectrum is denoted as I(d)', and the integral value of the peak of the methine C atom at the (e)' position attributed to the structural unit (e) is denoted as I(e)', the following formula (2) is satisfied. I(d)’ / (I(d)’ +I(e)’ )<0.763 (2) R in formula (d) and formula (e) 4 and R 5 are each hydrogen or a hydrocarbon group having 1 or more and 9 or less carbon atoms, respectively.

3. The polyvinyl acetal resin according to claim 1 or 2, which contains a structural unit (f) represented by the following formula (f), a structural unit (g) represented by the following formula (g), a structural unit (h) represented by the following formula (h), a structural unit (i) represented by the following formula (i), a structural unit (j) represented by the following formula (j), and a structural unit (k) represented by the following formula (k), In will pass 13 C-NMR nuclear magnetic resonance measurement 13 When, in the C-NMR spectrum, the integral value of the peak of the methine C atom at the (f)' position of the structural unit (f) is represented by I(f)', the integral value of the peak of the methine C atom at the (g)' position of the structural unit (g) is represented by I(g)', the integral value of the peak of the methine C atom at the (h)'2 position of the structural unit (h) is represented by I(h)'2, the integral value of the peak of the methine C atom at the (i)' position of the structural unit (i) is represented by I(i)', the integral value of the peak of the methine C atom at the (j)' position of the structural unit (j) is represented by I(j)', and the integral value of the peak of the methine C atom at the (k)' position of the structural unit (k) is represented by I(k)', the following formula (3) is satisfied: (I(f)’+I(g)’+I(h)’2) / (I(f)’+I(g)’+I(h)’2+I(i)’+I(j)’ +I(k)’ )<0.23 (3) R in formula (i), formula (j) and formula (k) 6 ~R 9 are each hydrogen or a hydrocarbon group having 1 to 9 carbon atoms.

4. The polyvinyl acetal resin according to any one of claims 1 to 3, having a weight average molecular weight Mw of 220,000 or more.

5. An interlayer film for laminated glass, which is an interlayer film for laminated glass having a single-layer structure or a multi-layer structure, and the interlayer film at least comprises a polyvinyl acetal resin layer containing the polyvinyl acetal resin according to any one of claims 1 to 4.

6. The interlayer film for laminated glass according to claim 5, after compression by a compression creep test carried out under the following conditions, the thickness change amount of the polyvinyl acetal resin layer is 80 μm or more, Compression creep test conditions: A specimen with a diameter of 8 mm and a thickness of 700 - 900 μm made of the polyvinyl acetal resin layer is compressed for 30 minutes under a load of 410 g and at a temperature of 30 °C, then the thickness T1 of the specimen is measured. Then, while maintaining a load of 410 g, the temperature is raised from 30 °C to 90 °C at a heating rate of 6 °C / minute, and then compressed for 5 minutes under a load of 410 g and at a temperature of 90 °C, and the thickness T2 of the specimen is measured. The absolute value of the difference between the thickness T1 and the thickness T2 of the specimen is taken as the thickness change amount.

7. The interlayer film for laminated glass according to claim 5 or 6, the polyvinyl acetal resin layer further contains a plasticizer.

8. The interlayer film for laminated glass according to claim 7, the plasticizer is at least one plasticizer selected from triethylene glycol - bis - 2 - ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glycerol ether, polyoxypropylene diglycerol ether, or derivatives in which a part of the hydrogen atoms of the terminal hydroxyl groups are substituted by alkyl groups.

9. A laminate comprising the interlayer film for laminated glass according to any one of claims 5 to 8, and a functional layer different from the interlayer film for laminated glass.

10. A laminated glass comprising a first laminated glass member, a second laminated glass member, and the interlayer film for laminated glass according to any one of claims 5 to 8 disposed between the first laminated glass member and the second laminated glass member.

11. A laminated glass comprising a first laminated glass member, a second laminated glass member, and the laminate according to claim 9 disposed between the first laminated glass member and the second laminated glass member.

Images