WO2022112045A1

WO2022112045A1 - Interlayer films for use in laminated glass and laminated glass

Info

Publication number: WO2022112045A1
Application number: PCT/EP2021/081725
Authority: WO
Inventors: Hiroyuki Arishima; Stephen Bennison
Original assignee: Kuraray Europe Gmbh
Priority date: 2020-11-27
Filing date: 2021-11-15
Publication date: 2022-06-02

Abstract

The provision of an interlayer film for use in laminated glass having high sound proofing and good followability of the curvature of transparent substrates properties.

Description

Interlayer films for use in laminated glass and laminated glass

The present invention relates to an interlayer film for use in laminated glass, and laminated glass.

It is known that glass plates used for window glass and the like has excellent durability and visible light transmittivity, but the damping performance (tan d in respect of flexural vibration) is very poor. Thus, a decrease in sound insulation due to resonance caused by the similarity of the vibration of the glass and the incident sound wave, giving rise to significantly reduced transmittance losses, that is, a coincidence effect, can occur.

On the other hand, in recent years, efforts have been made to reduce the weight of laminated glass to reduce the weight of vehicles (for example, automobiles) and improve fuel efficiency. Although the weight of the laminated glass can be generally reduced by reducing the thickness of the laminated glass, the sound insulation decreases in accordance with the degree of the weight reduction. Thus, to enable a weight reduction, a means to compensate for the sound insulation decrease is required.

As a method of increasing sound insulation, there is a method in which an interlayer film for use in laminated glass (hereinafter, also simply referred to as "the interlayer film") having excellent damping performance is used. The interlayer film is capable of converting vibration energy into heat energy to absorb the vibration energy. As examples of such an interlayer film, an interlayer film for use in laminated glass comprising polyvinyl butyral and having a certain level of impact resistance and sound insulation has been proposed (see, for example, Patent Document 1), an interlayer film comprising a resin film A and a resin film B in which the resin film A comprises a copolymer of polystyrene and a rubber based resin sandwiched and fixed between a resin film B comprised of a plasticized polyvinyl acetal resin (see, for example, Patent Document 2), and an interlayer film having a laminate in which 10 or more first layers containing polyvinyl acetal and a plasticizer are laminated (see, for example, Patent Document 3). Moreover, there have also been proposals to employ two or more interlayer films, and to sandwich glass in laminated glass in order to ameliorate the soundproofing thereof (for example, refer to Patent Documents 4 and 5).

PRIOR ART DOCUMENTS

• Patent Document 1 : Laid-open international patent application WO 2005/018969

• Patent Document 2: Japanese laid open unexamined patent JPA-2007-91491

• Patent Document 3: Laid-open international patent application WO 2013/031884

• Patent Document 4: Laid-open international patent application WO 2017/094884

• Patent Document 5: Laid-open international patent application WO 2018/057287 However, even when interlayer films for use in laminated glass as described in the above-mentioned Patent Documents 1 - 3 are used, the sound insulation properties of a laminated glass are not quite satisfactory, and further improvement in sound insulation properties is required due to requirements and the like for increased comfort of the environment in vehicles, or for improvement in fuel efficiency of automobiles by weight reduction of a laminated glass. Furthermore, in configurations sandwiching glass between a pair of outermost layers of glass in the laminated glass disclosed in the above described patent documents 4 - 5, while good sound insulation is easily derivable, because there is the difficulty arising from the processes of matching the positions of an interlayer film or glass, in the process of disposing glass between a pair of glass sheets, soundproofed glass with a simple configuration comprised of one sheet of interlayer film and a pair of outer layer glass sheets is preferable from the perspective of the simplicity of the manufacturing process.

In patent document 5, there is the proposal of using a rigid polymer instead of glass sandwiched between a pair of outermost layers of glass, but as will be described later, when rigid polymers are employed in the laminated glass manufacturing process, there is the issue of the difficulty of making the interlayer film follow the curved glass surface in high curvature laminated glass configurations.

Thus, the object of the present invention is to propose an interlayer film for use in laminated glass which follows the transparent substrate surface curvature, as well having high sound insulation properties.

As a result of intensive studies in relation to interlayer films for use in laminated glass, the inventors arrived at the present invention to resolve the issues described above. In other words, the present invention encompasses the following preferred embodiments.

[1] An interlayer film for use in laminated glass comprising layer B, layer A, layer C, layer A, layer B in that order, wherein that layer A comprises a first thermoplastic resin layer, and the resin material comprising layer A has a peak at which the tan d, measured by performing a complex shear viscosity test under the conditions of a frequency of 1 Hz according to JIS K 7244-10: 2005, is maximum in a range of -30°C or more and 10°C or less, and height of the peak of tan d is 1 .5 or more, and layer B is a layer comprising a second thermoplastic resin, configured from a different resin material to the resin material configuring layer A, and the resin material configuring layer B has a tensile storage elasticity modulus equal to or greater than 20 MPa and less than or equal to 1 .2 GPa when measured at 20°C in the conduct of a dynamic viscoelastic test at a frequency of 0.3 Hz in accordance with JIS K 7244-4:1999, and the thickness of layer B is equal to or greater than 100 pm and less than or equal to 2.0 mm, and layer C is a layer comprising a third thermoplastic resin, which is a different resin material to that configuring layer A, and may be configured from a resin material which is the same or different than the resin material configuring layer B, and the resin material configuring layer C has a tensile storage elasticity modulus of equal to or greater than 20 MPa and less than or equal to 1 .2 GPa when measured at 20°C in the conduct of a dynamic viscoelastic test at a frequency of 0.3 Hz in accordance with JIS K 7244-4:1999, and the thickness of layer C is equal to or greater than 100 miti and less than or equal to 2.0 mm, and the thickness of either one of layer B and layer C is equal to or greater than 900 miti and less than or equal to 2.0 mm.

[2] The interlayer film for use in laminated glass according to [1] above, wherein layer A comprises a hydrogenated product of a block copolymer having a block polymer (a) containing 60 mol% or more of an aromatic vinyl monomer unit and a block polymer (b) containing 60 mol% or more of a conjugated diene monomer unit as the first thermoplastic resin, and the hydrogenated product of the block copolymer has a content of the block polymer (a) of 25 wt% or less based on the total mass of the hydrogenated product of the block copolymer.

[3] The interlayer film for use in laminated glass according to [1] or [2] above, wherein the at least one of the layers B comprises a polyvinyl acetal resin or an ionomer resin as the second thermoplastic resin.

[4] The interlayer film for use in laminated glass according to [3] above, wherein layer B comprises the earlier mentioned polyvinyl acetal resin and the content of plasticizer is 50 parts weight or less relative to 100 parts weight of the polyvinyl acetal resin.

[5] The interlayer film for use in laminated glass according to [4] above, wherein the plasticizer is an ester- based plasticizer or an ether-based plasticizer having a fusion point of 30°C or less and a hydroxyl group value of 15 to 450 mg KOH/g.

[6] The interlayer film for use in laminated glass according to any one of [1] to [5] above, wherein the third thermoplastic resin of layer C comprises any one of acrylic resin, ionomer resin or polyvinyl acetal resin.

[7] The interlayer film for use in laminated glass according to [6] above wherein the C layer comprises the polyvinyl acetal resin and the content of plasticizer is equal to or greater than 15 parts weight and less than or equal to 55 parts weight in relation to 100 parts weight of the polyvinyl acetal resin.

[8] The interlayer film for use in laminated glass according to [7] above, wherein the plasticizer contained in layer C is an ester-based plasticizer or an ether-based plasticizer having a fusion point of 30°C or less and a hydroxyl group value of 15 to 450 mg KOH/g.

[9] The interlayer film for use in laminated glass according to any one of [1] to [8] above, wherein the total thickness of layer B and layer C is 2.5 mm or less. [10] The interlayer film for use in laminated glass according to any one of [1] to [9] above wherein the laminated glass derived by sandwiching the interlayer film for use in laminated glass employs two sheets of float glass having a length of 300 mm, a width of 25 mm, and a thickness of 1 .9 mm and the loss factor at a secondary resonance frequency measured by the center excitation method at 20°C is 0.58 or more.

[11] The laminated glass sandwiching an interlayer film for use in laminated glass according to any one of [1] to [10] above between two sheets of translucent substrate, wherein at least one sheet of the translucent substrates is inorganic glass having a thickness of 3.0 - 10.0 mm.

[12] The interlayer film for use in laminated glass according to [11] above, which is a windshield for a vehicle, a side window for a vehicle, a sunroof for a vehicle, a rear window for a vehicle, or a glass for a head up display.

[13] The laminated glass sandwiching an interlayer film for use in laminated glass according to one of [1] to [10] above between two sheets of translucent substrate, wherein at least one sheet of the translucent substrates is inorganic glass having a thickness of 1 .2 - 3.0 mm.

[14] Laminated glass according to [13] above which is glass for use in architecture.

According to the present invention, the provision of laminated glass providing not only an interlayer film having high sound insulation properties, but also an interlayer film for use in laminated glass which has good followability to the curvature of the transparent substrate thereof is enabled.

Fig. 1 shows a schematic sectional view showing a structure of one embodiment of an interlayer film for use in laminated glass of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the gist of the present invention.

The interlayer film for use in laminated glass of the present invention is an interlayer film comprising at least five layers including the sequence layer B, layer A, layer C, layer A and layer B.

Layer A is a layer containing the first thermoplastic resin, and the resin materials configuring layer A have a peak at which the tan d, measured by performing a complex shear viscosity test under the conditions of a frequency of 1 Hz according to JIS K 7244-10: 2005, is maximum in a range of -30°C or more and 10°C or less, (Hereafter this temperature is simply referred to as “The tan d peak temperatures”) and the height of the peak of tan d is 1 .5 or more.

Layer B is a layer comprising a second thermoplastic resin, configured from a different resin material to the resin material configuring layer A, and the resin material configuring layer B has a tensile storage elasticity modulus which is equal to or greater than 20 MPa and less than or equal to 1 .2 GPa when measured at 20°C in the conduct of a dynamic viscoelastic test at a frequency of 0.3 Hz in accordance with JIS K 7244-4:1999, and the thickness of layer B is equal to or greater than 100 pm and less than or equal to 2.0 mm.

Layer C is a layer comprising a third thermoplastic resin, which is a different resin material to that configuring layer A, and may be configured from a resin material which is the same or different than the resin material configuring layer B, and the resin material configuring layer C has a tensile storage elasticity modulus of equal to or greater than 20 MPa and less than or equal to 1 .2 GPa when measured at 20°C in the conduct of a dynamic viscoelastic test at a frequency of 0.3 Hz in accordance with JIS K 7244-4:1999, and the thickness of layer C is equal to or greater than 100 pm and less than or equal to 2.0 mm.

The thickness of either one of layer B and layer C is equal to or greater than 900 pm and less than or equal to 2.0 mm.

< Layer A>

The interlayer film for use in laminated glass of the present invention comprises at least two A layers. The thickness of the layers, considering that layers B and C are relatively thick, provide high soundproofing to the interlayer film for use in laminated glass by means of the inclusion of the interlayer film for use in laminated glass having multiple layers of A. Layer A is comprised of either the first thermoplastic resin, or alternatively comprises a resin composition including the first thermoplastic resin.

The resin material constituting layer A has a tan d peak temperature in the range of of -30°C or more and 10°C or less. When the tan d peak temperature is in the range which is lower than -30°C, the soundproofing is significantly lowered in the frequency band from 5000 Hz to 10,000 Hz. On the other hand, when the tan d peak temperature is in the range higher than 10°C, there is significant reduction in the soundproofing of frequencies in the range from 2000 Hz to 5000 Hz. Here, tan d is also termed the loss tangent, and is the shear loss modulus, less the shear dynamic elastic modulus, and the higher it is, the higher the soundproofing can be expected to be. Now, tan d is measured by means of the method in the later described embodiments. The tan d peak temperature is preferably equal to or greater than -25°C, more preferably equal to or greater than -20°C, preferably equal to or less than 0°C, and most preferably -5°C. When the tan d peak temperature is in the range between the lower limit value and the upper limit value good sound insulation in the frequency domain from 2000 Hz to 10,000 Hz is enabled.

As the adjustment method of the tan d peak temperature, for example as later described, when hydrogenated product of the block copolymer (A) is included as the thermoplastic resin configuring the resin material of layer A, the methods of the adjustment of the content of the block polymer (a), which is the hard segment in the block copolymer (A), or the types of monomers configuring the block polymer (b) which is the soft segment, or the adjustment of the glass transition temperature and the like or bonding morphology or each segment itself may be suggested. Specifically, for example, when the content amount of the block polymer (a) in respect of the block copolymer (A) is reduced, or the polymer types or modification of the combinations configuring the block polymer (b) are modified, such that the tan d peak temperature is adjusted (increased) are all available as options.

In this invention, the tan d peak height is at least 1 .5. When the tan d peak height is Less than 1 .5, it is difficult to derive the desirable soundproofing. The tan d peak height is preferably greater than 2.0, more preferably greater than 2.2, and particularly it is preferred to be in excess of 2.4. The upper limit of the tan d peak height is not particularly prescribed. The tan d peak height is normally less than 5.0.

As a method of increasing the tan d peak height, for example as later described, when hydrogenated additives are contained in the block copolymer (A), as the thermoplastic resins which are the resin material configuring layer A, micro phase separated structures form spherical structures, and we suggest that increased amounts of vinyl bonds and the like may occur in the polymeric block (b).

In relation to the resin material configuring layer A, the tensile storage elasticity modulus when measured at 20°C in the conduct of a dynamic viscoelastic test at a frequency of 0.3 Hz in accordance with JIS K 7244-4:1999 is preferably less than 20 MPa.

As long as the resin materials configuring layer A satisfied the above described tan d peak temperature and the tan d peak height conditions, there is no particular limit on the first thermoplastic resin. Preferably, as the first thermoplastic resin of layer A contains a hydrogenated product of a block copolymer having a block polymer (a) containing 60 mol% or more of an aromatic vinyl monomer unit and a block polymer (b) containing 60 mol% or more of a conjugated diene monomer unit as the first thermoplastic resin (hereinafter, also referred to as "block copolymer (A)"), and the hydrogenated product of the block copolymer has a content of the block polymer (a) of 25 wt% or less based on a total mass of the hydrogenated product of the block copolymer. Examples of the aromatic vinyl compound constituting the aromatic vinyl monomer unit include styrene, o- methylstyrene, m-methylstyrene, p-methylstyrene, a-methylstyrene, b-methytstyrene, 2,6- dimethylstyrene, indenes, and vinylnaphthalene. One aromatic vinyl compound can be used alone, or two or more aromatic vinyl compounds can be used in combination. Among them, from the viewpoint of production cost and physical property balance, styrene, a-methylstyrene, p-methylstyrene, and mixtures thereof are preferable, and styrene is more preferable.

The content of the aromatic vinyl monomer unit in the block polymer (a) is preferably 60 mol% or more, more preferably 80 mol% or more, more preferably 85 mol% or more, further preferably 90 mol% or more, particularly preferably 95 mol% or more, and can be substantially 100 mol%, based on all of the structural units constituting the block polymer (a). When the content of the aromatic vinyl monomer unit in the block polymer (a) is not less than the lower limit, good moldability or mechanical strength can be easily obtained.

The block polymer (a) can contain a structural unit derived from another unsaturated monomer, other than the aromatic vinyl monomer unit, as long as the object and effects of the present invention are not impaired. Examples of another unsaturated monomer include butadiene, isoprene, 2, 3- dimethylbutadiene, 1 , 3-pentadiene, 1 , 3-hexadiene, isobutylene, methyl methacrylate, methyl vinyl ether, N-vinylcarbazole, b-pinene, 8, 9-p-mentene, dipentene, methylene norbornene, and 2-methylene tetrahydrofuran.

The content of the other unsaturated monomer unit in the block polymer (a) is preferably less than 40 mol%, more preferably less than 20 mol%, more preferably less than 15 mol%, furthermore preferably less than 10 mol%, and particularly preferably less than 5 mol% based on all of the structural units constituting the block polymer (a). In a preferable embodiment of the present invention, the block polymer (a) substantially does not contain another unsaturated monomer unit as described above. When the block polymer (a) contains a unit derived from another unsaturated monomer described above, the bonding morphology is not particularly limited, and can be random or tapered.

The content of the aromatic vinyl monomer unit and the content of another unsaturated monomer unit in the block polymer (a) in the block copolymer (A) can be determined from the ¹H-NMR spectrum of the block copolymer (A), and can be adjusted to the desired content by adjusting the charge ratio of each monomer in the preparation of the block copolymer (A).

The block copolymer (A) need only have at least one block polymer (a). When the block copolymer (A) has two or more block polymers (a), the two or more block polymers (a) can be the same or different from each other. In the present specification, "different block polymers" means that at least one of the monomer units constituting the block polymer, the weight average molecular weight, the stereoregularity, and, in a case where the block polymer has multiple monomer units, the ratio of each monomer unit and the form of copolymerization (random, gradient, block) is different. This also applies to the block polymer (b) described later.

The weight average molecular weight (Mw) of the block polymer (a) contained in the block copolymer (A) is not particularly limited. The weight average molecular weight of at least one block polymer (a) of the block polymers (a) contained in the block copolymer (A) is preferably 3,000 to 60,000, and more preferably 4,000 to 50,000. When the block copolymer (A) has at least one block polymer (a) having a weight average molecular weight within the above-mentioned range, the mechanical strength is better and a good film-forming property can be easily obtained. The weight average molecular weight is a weight average molecular weight in terms of polystyrene determined by gel permeation chromatography (GPC) measurement.

The glass transition temperature of the block polymer (a) is preferably 120°C or less, more preferably 110°C or less, preferably 60°C or more, and more preferably 70°C or more. When the glass transition temperature of the block polymer (a) is within the range between the lower limit and the upper limit described above, the shear storage elasticity modulus of the resin material constituting layer A can be easily controlled to a specific range, which leads to improved sound insulation and increased mechanical strength of the derived interlayer film. The glass transition temperature of the block polymer (a) can be measured by the method described in embodiments below and can be adjusted to a desired range by adjusting the charge ratio of each monomer in the preparation of the block copolymer (A).

The content of the block polymer (a) in the hydrogenated product of the block copolymer (A) [the total content thereof when the block copolymer (A) has multiple block polymers (a)] is preferably 25 wt% or less based on the total mass of the hydrogenated product of the block copolymer (A). The value of a tan d tends to change depending on the morphology of the block copolymer (A), and the tan d tends to increase especially when a microphase-separated structure having a spherical structure is formed. Because the content of the block polymer (a) in the hydrogenated product of the block copolymer (A) has a great influence on the ease of formation of a spherical structure, to further improve the sound insulation of the derived interlayer film, it is very advantageous that the content of the block polymers (a), based on the total mass of the hydrogenated product of the block copolymer (A), is adjusted to preferably 25 wt% or less. The content of the block polymer (a) is preferably up to 20 wt%, more preferably up to 15 wt%, more preferably 14 wt% or less, more preferably 13 wt% or less, more preferably 12.5 wt% or less, more preferably 11 wt% or less, and particularly preferably 9 wt% or less. From the viewpoint of sound insulation, the content of the block polymer (a) is preferably 3 wt% or more, and more preferably 3.5 wt% or more. In one embodiment of the present invention, the content of the block polymer (a) is preferably 3 to 25 wt%. Meanwhile, from the viewpoint of easily improving the handleability and mechanical properties of layer A, the content of the block polymer (a) is preferably 6 to 25 wt%, more preferably 8 to 25 wt%, and particularly preferably 10 to 25 wt%. In one embodiment of the present invention, the content of the block polymer (a) is preferably 3.5 to 25 wt%, and more preferably 4 to 15 wt%, and when the content of the block polymer (a) is within the above-mentioned range, the handleability and mechanical properties of the derived layer A can be increased while ensuring high sound insulation.

Now, the content of the block polymer (a) in the hydrogenated product of the block copolymer (A) may be derived from the 1 H-NMR spectra of the hydrogenated additive of the block copolymer (A) and may be adjusted to the desired range by means of adjusting the charge ratio of each monomer in the manufacture of the block copolymer (A).

Examples of the conjugated diene compound constituting the conjugated diene monomer unit contained in the block polymer (b) include isoprene, butadiene, hexadiene, 2,3-dimethyl-1 ,3-butadiene, 1 ,3- pentadiene, and myrcene. One conjugated diene compound can be used alone, or two or more conjugated diene compounds can be used in combination. Among these, isoprene, butadiene, and a mixture of isoprene and butadiene are preferable, and isoprene is more preferable from the viewpoint of availability, versatility, controllability of the bonding morphology described later and the like.

As the conjugated diene compound, a mixture of butadiene and isoprene can be used. Although the admixture ratio [isoprene/butadiene] (mass ratio) is not particularly limited, it is preferably 5/95 to 95/5, more preferably 10/90 to 90/10, further preferably 40/60 to 70/30, and particularly preferably 45/55 to 65/35. When the admixture ratio [isoprene/butadiene] is represented by a molar ratio, it is preferably 5/95 to 95/5, more preferably 10/90 to 90/10, further preferably 40/60 to 70/30, and particularly preferably 45/55 to 55/45.

The content of the conjugated diene monomer unit in the block polymer (b) is preferably 60 mol% or more, more preferably 65 mol% or more, and particularly preferably 80 mol% or more based on all of the structural units constituting the block polymer (b). When the content of the conjugated diene monomer unit is not less than the lower limit, the amount of the segment providing the sound insulation properties can be sufficient, and an interlayer film with excellent sound insulation properties can be easily obtained. The upper limit of the content of the conjugated diene monomer unit is not particularly prescribed. The content of the conjugated diene monomer unit can be 100 mol%. The block polymer (b) can have structural units derived from one conjugated diene compound or can have structural units derived from two or more conjugated diene compounds. As described above, in the present invention, the block polymer (b) preferably contains 60 mol% or more of the conjugated diene monomer unit. The block polymer (b) preferably contains a structural unit derived from isoprene (hereinafter, may be abbreviated as "isoprene unit"), a structural unit derived from butadiene (hereinafter, may be abbreviated as "butadiene unit"), or the isoprene unit and the butadiene unit as the conjugated diene monomer unit(s) preferably in an amount of 60 mol% or more. This tends to result in an interlayer film having excellent sound insulation.

When the block polymer (b) has two or more conjugated diene monomer units, their bonding morphology can be random, tapered, completely alternating, partially block-shaped, block, or a combination of two or more thereof

The block polymer (b) can contain a structural unit derived from another polymerizable monomer other than the conjugated diene monomer unit, as long as the object and effects of the present invention are not impaired. Examples of another polymerizable monomer include styrene, a-methylstyrene, o- methylstyrene, m-methylstyrene, p-methylstyrene, p-t-butylstyrene, 2, 4-dimethylstyrene, aromatic vinyl compounds such as vinylnaphthalene and vinylanthracene, and methyl methacrylate, methyl vinyl ether, N-vinylcarbazole, b-pinene, 8, 9-p-mentene, dipentene, methylenenorbomene, 2- methylenetetrahydrofuran, 1 , 3-cyclopentadiene, 1 , 3-cyclohexadiene, 1 , 3-cycloheptadiene, and 1 , 3- cyclooctadiene. Among them, styrene, a-methylstyrene, and p-mediylstyrene are preferable, and styrene is the most preferable. When the block polymer (b) contains another polymerizable monomer unit described above, the specific combination is preferably isoprene and styrene, and butadiene and styrene, and more preferably isoprene and styrene. When the block polymer (b) contains such a combination, the tan d of the resin material constituting layer A may increase.

The content of other polymerizable monomer units in the block polymer (b) is preferably less than 40 mol%, more preferably less than 35 mol%, and particularly preferably less than 20 mol% based on all of the structural units constituting the block polymer (b). When the block polymer (b) contains another polymerizable monomer unit described above, the bonding morphology is not particularly limited, and can be random or tapered.

The content of the conjugated diene monomer unit and the content of other polymerizable monomer units in the block polymer (b) in the block copolymer (A) can be determined from the ¹H-NMR spectrum of the block copolymer (A) and can be adjusted to desired contents by adjusting the charge ratio of each monomer in the preparation of the block copolymer (A). When the structural unit constituting the block polymer (b) contains an isoprene unit or a butadiene unit, the bonding morphology of isoprene can be a 1 , 2-bond, a 3, 4-bond, or a 1 , 4-bond, and the bonding morphology of butadiene can be a 1 , 2-bond or a 1 , 4-bond.

The total content of the 3, 4-bond unit and the 1 , 2-bond unit in the block polymer (b) in the block copolymer (A) (hereinafter may be referred to as "vinyl bond content") is preferably 20 mol% or more, more preferably 40 mol% or more, and particularly preferably 50 mol% or more. Although the total vinyl bond content is not particularly limited, it is preferably 90 mol% or less, and more preferably 85 mol% or less. The vinyl bond content can be calculated by dissolving the block copolymer (A) before hydrogenation in CDCh and measuring the ¹H-NMR spectrum. When the structural unit constituting the block polymer (b) is composed only of isoprene units, the vinyl bond content is calculated from the ratio of the peak areas corresponding to the 3, 4-bond units and the 1 , 2-bond units to the total peak area of the isoprene units. When the structural unit constituting the block polymer (b) is composed only of butadiene units, the vinyl bond content is calculated from the ratio of the peak area corresponding to the 1 , 2-bond units to the total peak area of the butadiene units. When the structural unit constituting the block polymer (b) contains an isoprene unit and a butadiene unit, the vinyl bond content is calculated from the ratio of the peak areas corresponding to the 3, 4-bond unit and the 1 , 2-bond unit of the isoprene units and the 1 , 2-bond unit of the butadiene units to the total peak areas of the isoprene units and the butadiene units.

As the vinyl bond content increases, the tan d value of the resin material constituting layer A tends to increase, and the sound insulation of the derived interlayer film can be improved by controlling the peak position of the tan d within the specific temperature range. The vinyl bond content can be adjusted within the desired range, for example, by adjusting the addition amount of the organic Lewis base used in the anionic polymerization for producing the block copolymer (A).

The weight average molecular weight of the block polymer (b) contained in the block copolymer (A) in the state before hydrogenation, from the viewpoint of sound insulation and the like, is preferably 15,000 to 800,000, more preferably 50,000 to 700,000, further preferably 70,000 to 600,000, particularly preferably 90,000 to 500,000, and most preferably 130,000 to 450,000. The weight average molecular weight means the weight average molecular weight in terms of polystyrene determined by gel permeation chromatography (GPC) measurement. The weight average molecular weight of the block polymer (b) means the value calculated from the difference between the weight average molecular weight before copolymerization of the block polymer (b) and the weight average molecular weight after the copolymerization of the block polymer (b).

The glass transition temperature of the block polymer (b) is preferably 10°C or less, more preferably 0°C or less, and preferably -30°C or more, and more preferably -20°C or more. When the glass transition temperature of the block polymer (b) is within the range between the lower limit and the upper limit described above, the tan d peak temperature of the resin material constituting layer A can be easily controlled to a specific range, which leads to the improved sound insulation of the derived interlayer film. The glass transition temperature of the block polymer (b) can be measured by the method described in the embodiments described below, and can be adjusted to a desired range by adjusting the charge ratio of each monomer in the preparation of the block copolymer (A).

The block copolymer (A) need only have at least one block polymer (b) described above. When the block copolymer (A) has two or more block polymers (b), the two or more block polymers (b) can be the same or different from each other.

The content of the block polymer (b) in the hydrogenated product of the block copolymer (A) [the total content thereof when the block copolymer (A) has multiple block polymers (b)] is preferably 75 to 97 wt% based on the total mass of the hydrogenated product of the block copolymer (A). When the content of the block polymer (b) is within the above-mentioned range, the hydrogenated product of the block copolymer (A) tends to have appropriate flexibility or good moldability. Moreover, the value of a tan d tends to change depending on the morphology of the hydrogenated product of the block copolymer (A), and the tan d tends to increase especially when a microphase-separated structure having a spherical structure is formed. Because the content of the block polymer (b) in the hydrogenated product of the block copolymer (A) has a great influence on the ease of the formation of spherical structures, it is very advantageous that the content of the block polymer (b) based on the total mass of the hydrogenated product of the block polymer (A) is preferably adjusted to 75 to 97 wt% to improve the sound insulation of the derived interlayer film. The content of the block polymer (b) is more preferably 75 to 96.5 wt%, further preferably 85 to 96 wt%, and particularly preferably 90 to 96 wt%. Meanwhile, from the viewpoint of easily improving the handleability and mechanical properties of layer A, the content of the block polymer (b) is preferably 75 to 94 wt%, more preferably 75 to 92 wt%, and particularly preferably 75 to 90 wt%. In a preferable embodiment of the present invention, the content of the block polymer (b) is 75 to 96.5 wt%. When the content of the block polymer (b) is within this range, the handleability and mechanical properties of the derived layer A can be increased while ensuring good sound insulation.

The content of the block polymer (b) in the hydrogenated product of the block copolymer (A) is determined from the ¹H-NMR spectrum of the hydrogenated product of the block copolymer (A) and can be adjusted to a desired range by adjusting the charge ratio of each monomer in the preparation of the block copolymer (A).

As long as the block polymer (a) and the block polymer (b) are bound to each other in the block copolymer (A), the bonding morphology is not limited and can be linear, branched, radial, or any combination of two or more these. Among them, the bonding morphology of the block polymer (a) and the block polymer (b) is preferably linear. Examples thereof include, when the block polymer (a) is represented by a and the block polymer (b) is represented by b, a diblock copolymer represented by a-b, a triblock copolymer represented by a-b-a, a tetrablock copolymer represented by a-b-a-b, and a pentablock copolymer represented by a-b-a-b-a. Among them, a linear triblock copolymer or diblock copolymer is preferable, and an a-b-a type triblock copolymer is preferably used from the viewpoint of flexibility and ease of production.

In the present invention, as the first thermoplastic resin of layer A, at least one hydrogenated product of the block copolymer (A) (hereinafter, may be referred to as "hydrogenated block copolymer (A)") is preferably included.

From the viewpoint of heat resistance, weather resistance, and sound insulation, 80 mol% or more of the carbon-carbon double bond of the block polymer (b) is preferably hydrogenated (hereinafter, may be abbreviated as "hydrogenation"), 85 mol% or more is more preferably hydrogenated, 88 mol% or more is further preferably hydrogenated, and 90 mol% or more is particularly preferably hydrogenated (hereinafter, this value may be referred to as "hydrogenation rate"). The upper limit of the hydrogenation rate is not particularly limited. The hydrogenation rate can be 99 mol% or less, and can be 98 mol% or less. The hydrogenation rate is a value calculated from the content of carbon-carbon double bond in the conjugated diene monomer unit in the block polymer (b) determined by ¹H-NMR measurement before and after hydrogenation.

The weight average molecular weight of the hydrogenated block copolymer (A) determined in terms of standard polystyrene by gel permeation chromatography is preferably 15,000 to 800,000, more preferably 50,000 to 700,000, further preferably 70,000 to 600,000, particularly preferably 90,000 to 500,000, and most preferably 130,000 to 450,000. When the weight average molecular weight of the hydrogenated block copolymer (A) is not less than the lower limit, heat resistance tends to be high, and when the weight average molecular weight of the hydrogenated block copolymer (A) is not more than the upper limit, the moldability tends to be good.

The method for manufacturing the block copolymer (A) is not particularly limited. The block copolymer (A) can be manufactured by, for example, an anionic polymerization method, a cationic polymerization method, or a radical polymerization method.

When a conjugated diene monomer is used, the 1 , 2-bond amount and the 3, 4-bond amount of the first thermoplastic resin can be increased by addition of an organic Lewis base during anionic polymerization, and the 1 , 2-bond amount and the 3, 4-bond amount, that is, the vinyl bond content of the first thermoplastic resin can be easily controlled by adjustment of the addition amount of the organic Lewis base. As the vinyl bond content increases, the tan d value of the resin material constituting layer A tends to increase. Thus, by controlling the peak position of the tan d within a specific temperature range, the sound insulation of the derived interlayer film can be improved.

The hydrogenated block copolymer (A) can be derived by subjecting the block copolymer (A) to a hydrogenation reaction.

Examples of the method of subjecting the unhydrogenated block copolymer (A) to a hydrogenation reaction include a method in which a mixture derived by separating the unhydrogenated block copolymer (A) from the reaction liquid containing the produced block copolymer (A) and dissolving the separated unhydrogenated block copolymer (A) in a solvent which is inert to hydrogenation catalysts and reacting with hydrogen, or an unhydrogenated block copolymer (A) in the reaction liquid is reacted with hydrogen in the presence of a hydrogenation catalyst. The hydrogenation rate is preferably 80 mol% or more, more preferably 85 mol% or more, further preferably 88 mol% or more, and particularly preferably 90 mol% or more.

The resin material constituting layer A preferably contains the hydrogenated block copolymer (A) as the first thermoplastic resin in an amount of 60 wt% or more, more preferably 70 wt% or more, and further preferably 80 wt% or more based on the total mass of the resin material. The resin material constituting layer A can contain, in addition to the hydrogenated block copolymer (A), as needed, and as long as the effect of the present invention is not impaired, other thermoplastic resins (for example, hydrogenated resins such as a hydrogenated cumarone indene resin, a hydrogenated rosin resin, a hydrogenated terpene resin, and an alicyclic hydrogenated petroleum resin; adhesive-imparting resins such as aliphatic resin composed of olefin and diolefin polymer; and hydrogenated polyisoprene, hydrogenated polybutadiene, butyl rubber, polyisobutylene, polybutene, polyolefin elastomer, specifically, ethylene- propylene copolymer, ethylene-butylene copolymer, propylene-butylene copolymer, polyolefin resin, olefin polymer, and polyethylene resin). Particularly preferably, the resin material constituting layer A is composed of the hydrogenated block copolymer (A) as the first thermoplastic resin.

In the interlayer film for use in laminated glass of the present invention, the thickness of one layer A is preferably 50 pm or more and 450 pm or less. The optimum thickness of layer A varies depending on the thicknesses of other layers constituting the interlayer film (for example, layer B and the C layer described later), the storage elastic modulus of each layer and the like. As layer A becomes thicker, while the sound insulation becomes higher, the storage elastic modulus of the whole interlayer film tends to decrease. Thus, when the thickness of one layer A is more than 450 miti, the frequency range where the coincidence effect of the laminated glass occurs tends to be more than 6,000 Hz, and the decrease in sound insulation in a frequency range of 6,000 Hz or more may become significant. From the viewpoint of further increasing the sound insulation in the high frequency range, the thickness of one layer A is more preferably 350 pm or less, and particularly preferably 300 pm or less. When the thickness of layer A is less than 50 pm, the storage elastic modulus may become high, and the frequency range where the coincidence effect occurs may be in the medium frequency range. Thus, the decrease in sound insulation in a medium frequency range of 4,000 to 6,000 Hz may become significant. In particular, sound insulation in this frequency range is practically important, and the improving effect of sound insulation also decreases as the thickness of layer A decreases. Thus, the thickness of one layer A is more preferably 70 pm or more, particularly preferably 90 pm or more, and further preferably 110 pm or more. The total thickness of the multiple A layers is preferably 950 pm or less, and more preferably 700 pm or less. The thicknesses of each of the multiple A layers can be the same or different. The thickness can be measured with a thickness gauge. The multiple A layers can be composed of the same resin material or different resin materials.

The resin material constituting layer A may have an antioxidant, an ultraviolet radiation absorber, a light stabilizer, an anti-blocking agent, a pigment, a dye, a heat shield material as described below or the like added as other components, as needed. In the interlayer film for use in laminated glass of the present invention, these additives can be contained in one or more layers selected from the group consisting of multiple A layers, one layer B or multiple B layers, and one C layer or multiple C layers. When the additives are contained in two or more layers selected from the above-mentioned group, those layers can contain the same additive or different additives.

Examples of the antioxidant include a phenol-based antioxidant, a phosphorus-based antioxidant, and a sulfur type antioxidant

The amount of the antioxidant added is preferably 0.001 parts weight or more, more preferably 0.01 parts weight or more, preferably 5 parts weight or less, and more preferably 1 parts weight or less relative to 100 parts weight of the first thermoplastic resin. When the amount of the antioxidant is not less than the lower limit and not more than the upper limit, a sufficient antioxidant effect is enabled.

Examples of the ultraviolet radiation absorbers include a benzotriazole ultraviolet radiation absorber, a hindered amine ultraviolet radiation absorber, a benzoate ultraviolet radiation absorber, a triazine-based compound, a benzophenone-based compound, a malonic ester-based compound, an indole-based compound, and an anilide oxalate-based compound. One ultraviolet radiation absorber can be used alone, or two or more ultraviolet radiation absorbers can be used in combination. In one preferable embodiment of the present invention, an ultraviolet radiation absorption agent is added to at least one layer of the interlayer film for use in laminated glass, and preferably at least one of the ultraviolet absorption agents exemplified above are selected for inclusion.

The amount of the ultraviolet radiation absorber added is preferably 10 ppm or more, more preferably 100 ppm or more, preferably 50,000 ppm or less, and more preferably 10,000 ppm or less based on the mass of the first thermoplastic resin. When the addition amount of the ultraviolet radiation absorber is within the range between the lower limit and the upper limit, a sufficient ultraviolet absorbing effect can be expected.

As photostabilization agents, for example, hindered amine type photostabilization agents and the like can be suggested.

Examples of the anti-blocking agent include inorganic particles and organic particles. Examples of the inorganic particles include oxides, hydroxides, sulfides, nitrates, halides, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylates, silicates, titanates, and borates of Group IA elements, Group IIA elements, Group IVA elements, Group VIA elements, Group VI I A elements, Group VIIIA elements, Group IB elements, Group MB elements, Group NIB elements, and Group IVB elements, and hydrates thereof; and composite compounds and natural mineral particles containing them as a principal component. The principal component is a component having the highest content. Examples of the organic particles include fluroplastic resins, melamine resins, styrene-divinylbenzene copolymers, acrylictype resin silicone, and crosslinked products thereof.

By containing the heat shield material in the interlayer film for use in laminated glass, a heat shield function can be imparted to the interlayer film for use in laminated glass, and the transmittance of near- infrared light having a wavelength of about 1 ,500 nm in the laminated glass can be reduced.

In one preferred embodiment of the present invention, at least one layer of the interlayer film for use in laminated glass includes heat shielding material. In that embodiment, the heat shielding material is preferably tin-doped indium oxide, antimony-doped tin oxide, zinc antimonate, metal doped tungsten oxide, diimonium-based dye, aminium-based dye, phthalocyanine-based dye, anthraquinone-based dye, polymethine-based dye, a benzenedithiol-type ammonium-based compound, a thiourea derivatives, and thiol metal complexes. One heat shield material can be used alone, or two or more heat shield materials can be used in combination

When heat shielding particles are used as the heat shield material, the content is preferably 0.01 wt% or more, more preferably 0.05 wt% or more, further preferably 0.1 wt% or more, particularly preferably 0.2 wt% or more, preferably 5 wt% or less, and more preferably 3 wt% or less. In the present invention, the heat shield material can be contained in any of layer A, layer B which is described later, layer C which is described later (when the third thermoplastic resin is contained), and the D layer described below when it is present, and the "content" means the amount in respect of the total mass of 100 wt% of all of the resin materials constituting the A layer, the B layer, the C layer, and when the third thermoplastic resin is contained, and the D layer when it is present. The "content" of the organic dye compound described later has the same meaning. When the content of the heat shielding particles is within the range between the lower limit and the upper limit, the transmittance of the near-infrared light having a wavelength of about 1 ,500 nm can be effectively reduced without affecting the transmittance of visible light of the laminated glass comprising the derived interlayer film. From the viewpoint of transparency of the interlayer film, the average particle diameter of the heat ray shielding particles is preferably 100 nm or less, and more preferably 50 nm or less. The average particle diameter is the average particle diameter measured by a laser diffractometer.

When an organic dye compound is used as the heat shield material, the content is preferably 0.001 wt% or more, more preferably 0.005 wt% or more, further preferably 0.01 wt% or more, preferably 1 wt% or less, and more preferably 0.5 wt% or less. When the content of the organic dye compound is within the range between the lower limit and the upper limit, the transmittance of the near-infrared light having a wavelength of about 1 ,500 nm can be effectively reduced without affecting the transmittance of visible light of the laminated glass comprising the derived interlayer film.

The interlayer film for use in laminated glass of the present invention preferably comprises layer B at least on the side that comes into contact with the transparent substrate (For example, glass, etc.), and layer B is preferably a layer having adhesiveness to the transparent substrate. Layer B is a layer comprising the second thermoplastic resin and is configured from a resin material which is different from the resin material configuring layer A. In the present invention, “configured from a resin material which is different from the resin material configuring layer A” means being configured from a resin material other than the same resin material configuring layer A. The resin material configuring layer B either has a peak at which the tan d, measured by performing a complex shear viscosity test under the conditions of a frequency of 1 Hz according to JIS K 7244-10: 2005, is not maximal in a range of -30°C or more and 10°C or less, or the tan d is less than 1 .5. The resin material configuring layer B either comprises the second thermoplastic resin, or is a resin composition containing the second thermoplastic resin.

In relation to the resin material configuring layer B, the tensile storage elasticity modulus when measured at 20°C in the conduct of a dynamic viscoelastic test at a frequency of 0.3 Hz in accordance with JIS K 7244-4:1999 is preferably equal to or greater than 20 MPa and less than or equal to 1 .2 GPa. In general, the flexural rigidity of sheets shaped materials correlates tensile storage elasticity modulus and thickness. When the tensile storage elasticity modulus is greater than 1 .2 GPa, the flexural rigidity of the interlayer film can easily become elevated. Because of this, the interlayer film does not follow the curvature of the transparent substrate when laminating the transparent substrate with the interlayer film on the occasion of manufacturing the laminated glass, and the interlayer film can adopt a floating state over at least part of the concave curved surface of the transparent substrate, in addition to, the interlayer film adopting a floating state over at least part of the convex curved surface of the transparent substrate, and when strongly pressed to the transparent substrate in order to achieve a tight bonding between the transparent material and the interlayer film, problems may arise from the generation of cracks in the transparent substrate, or the generation of positional slippage in the adhesive processes thereafter. Moreover, after the adhesive process, gaps may be generated between the interlayer film and the transparent substrate. In addition, when the tensile storage elasticity modulus is less than 20 MPa, problems may be generated with the worsening of the handleability concomitant with the tackiness of the interlayer film surface, or difficulties in deriving the desired soundproofing.

That tensile storage elasticity modulus is preferably equal to or greater than 25 MPa, more preferably equal to or greater than 35 MPa, and preferably less than or equal to 1 .1 GPa, more preferably less than or equal to 1 .0 GPa. When that tensile storage elasticity modulus is in the range between the above described upper limit value and the lower limit value, the problems described above are not easily generated.

As the method of adjusting the above described tensile storage elasticity modulus, for example, the methods of the appropriate selection of the second thermoplastic resin, or the type of plasticizer adjustment of the content thereof may be suggested.

There is no particular prescription on the second thermoplastic resin, as long as the resin material configuring layer B satisfies the conditions of the above described tensile storage elasticity modulus. At least one layer of the B layers preferably comprises a polyvinyl acetal resin or an ionomer resin as the second thermoplastic resin. By layer B comprising a polyvinyl acetal resin or an ionomer resin, the glass scattering on breakage of the laminated glass manufactured using the interlayer film for use in laminated glass of the present invention can be easily reduced.

When a polyvinyl acetal resin is used as the second thermoplastic resin, the degree of acetalization of the polyvinyl acetal resin is preferably 40 mol% or more, more preferably 60 mol% or more, and preferably 90 mol% or less, more preferably 85 mol% or less, and further preferably 80 mol% or less. The degree of acetalization is the amount of an acetal-forming units on the basis of one repeating unit which is a unit consisting of two carbons of the main chain in the polyvinyl alcohol-based resin as the raw material of the polyvinyl acetal resin (for example, a vinyl alcohol unit, a vinyl acetate unit, an ethylene unit and the like). From the viewpoint of process, the degree of acetalization is preferably within the range between the lower limit and the upper limit, because, in that case, the mutual solubility of the polyvinyl acetal resin and the plasticizer tends to be good, and a resin material containing the polyvinyl acetal resin and the plasticizer can be easily obtained. The degree of acetalization of the polyvinyl acetal resin is preferably 65 mol% or more from the viewpoint of water resistance. The degree of acetalization can be adjusted by adjusting the amount of an aldehyde used in the acetalization reaction.

The content of the vinyl acetate units in the polyvinyl acetal resin is preferably 30 mol% or less, and more preferably 20 mol% or less. The content of the vinyl acetate unit is the amount of the vinyl acetate units on the basis of one repeating unit which is a unit consisting of two carbons of the main chain in the polyvinyl alcohol-based resin as a raw material of the polyvinyl acetal resin (for example, vinyl alcohol units, vinyl acetate units, ethylene units and the like). When the content of the vinyl acetate unit is not more than the upper limit, blocking is unlikely to occur during the production of the polyvinyl acetal resin, and the production is facilitated. The lower limit of the content of the vinyl acetate unit is not particularly limited. The content of the vinyl acetate unit is usually 0.3 mol% or more. The content of the vinyl acetate unit can be adjusted by appropriately adjusting the degree of saponification of the polyvinyl alcohol-based resin which is the raw material.

The content of the vinyl alcohol unit of the polyvinyl acetal resin is preferably 5 mol% or more, more preferably 10 mol% or more, further preferably 15 mol% or more, and preferably 35 mol% or less, more preferably 30 mol% or less, further preferably 25 mol% or less, and particularly preferably 20 mol% or less. The content of the vinyl alcohol unit is an amount of a vinyl alcohol unit on the basis of one repeating unit which is a unit consisting of two carbons of the main chain in the polyvinyl alcohol-based resin as a raw material of the polyvinyl acetal resin (for example, vinyl alcohol units, vinyl acetate units, ethylene units and the like). When the content of the vinyl alcohol units is above the previously described lower value limit, the control of the adhesiveness to transparent substrates, in particular glass, is enabled. Moreover, when the content of the vinyl alcohol units is less than the above described upper limit value, the penetration resistance and the impact resistance functions demanded of intermediate films of safety glass can be easily controlled. The content of the vinyl alcohol units can be adjusted by means of adjusting the amount of aldehyde used in the acetalization reaction. The polyvinyl acetal resin is usually composed of an acetal-forming unit, a vinyl alcohol unit, and a vinyl acetate unit, and the amount of each unit is measured by, for example, JIS K 6728 'Testing method for polyvinyl butyral" or nuclear magnetic resonance (NMR).

Only one type of polyvinyl acetal resin can be used alone, or two or more polyvinyl acetal resins types having different degrees of acetal ization, viscosity-average degrees of polymerization or the like can be used in combination.

The polyvinyl acetal resin can be produced by a conventional known method. Typically, it can be produced by acetalizing a polyvinyl alcohol-based resin (for example, a polyvinyl alcohol resin or an ethylene vinyl alcohol copolymer) with an aldehyde. Specifically, for example, a polyvinyl alcohol-based resin is dissolved in warm water, the derived aqueous solution is maintained at a predetermined temperature (for example, 0°C or more, preferably 10°C or more, and for example 90°C or less, preferably 20°C or less), the required acid catalyst and aldehyde are added, and the acetalization reaction is proceeded while stirring. Then, the reaction temperature is increased to about 70°C for aging to complete the reaction, and then neutralization, washing with water, and drying are performed to obtain a polyvinyl acetal resin powder.

The viscosity-average degree of polymerization of the polyvinyl alcohol-based resin, which is a raw material of the polyvinyl acetal resin is preferably 100 or more, more preferably 300 or more, more preferably 400 or more, further preferably 600 or more, particularly preferably 700 or more, and most preferably 750 or more. When the viscosity-average degree of polymerization of the polyvinyl alcohol- based resin is too low, the penetration resistance and the creep resistance, particularly the creep resistance under high temperature and high humidity conditions such as 85°C and 85% RH may decrease. The viscosity-average degree of polymerization of the polyvinyl alcohol-based resin is preferably 5,000 or less, more preferably 3,000 or less, further preferably 2,500 or less, particularly preferably 2,300 or less, and most preferably 2,000 or less. When the viscosity-average degree of polymerization of the polyvinyl alcohol-based resin is too high, the molding of layer B may be difficult

Further, to improve the laminating suitability of the derived interlayer film for use in laminated glass and obtain a laminated glass having a better appearance, the viscosity-average degree of polymerization of the polyvinyl alcohol-based resin is preferably 1 ,500 or less, more preferably 1 ,100 or less, and further preferably 1 ,000 or less.

The preferable value of the viscosity-average degree of polymerization of the polyvinyl acetal resin is the same as the preferable value of the viscosity-average degree of polymerization of the polyvinyl alcohol- based resin. To set the amount of the vinyl acetate unit of the derived polyvinyl acetal resin to 30 mol% or less, a polyvinyl alcohol-based resin having a degree of saponification of 70 mol% or more is preferably used. When the degree of saponification of the polyvinyl alcohol-based resin is not less than the lower limit, the transparency and heat resistance of the resin tend to be excellent, and the reactivity with an aldehyde is good. The degree of saponification is more preferably 95 mol% or more.

The viscosity-average degree of polymerization and the degree of saponification of the polyvinyl alcohol- based resin can be measured based on, for example, JIS K 6726 "Testing method for polyvinyl alcohol".

As the aldehyde used for acetalization of the polyvinyl alcohol-based resin, an aldehyde having one or more and 12 or less carbon atoms is preferable. When the number of carbon atoms of the aldehyde is within the above-mentioned range, the reactivity of acetalization is good, blocking of the resin is less likely to occur during the reaction, and the polyvinyl acetal resin can be easily synthesized.

The aldehyde is not particularly prescribed, and examples thereof include aliphatic, aromatic, or alicyclic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, n-hexylaldehyde, 2-ethylbutyraldehyde, n-heptylaldehyde, n-octylaldehyde, n- nonylaldehyde, n-decylaldehyde, benzaldehyde, and cinnamaldehyde. Among these, aliphatic aldehydes having two or more and six or less carbon atoms are preferable, and n-butyraldehyde is particularly preferable. Only one aldehyde can be used alone, or two or more aldehydes can be used in combination. Further, polyfunctional aldehydes, other aldehydes having a functional group or the like can be used in combination in small amounts within a range of 20 wt% or less of the total aldehyde.

As the polyvinyl acetal resin, a polyvinyl butyral resin is most preferable. As the polyvinyl butyral resin, a modified polyvinyl butyral resin derived by butyralization of a polyvinyl alcohol polymer derived by saponification of a copolymer of a vinyl ester and another monomer with butyraldehyde can be used. Examples of another monomer include ethylene, propylene, and styrene. As another monomer, a monomer having a hydroxyl group, a carboxyl group, or a carboxylate group can be used.

When layer B contains the polyvinyl butyral resin as the second thermoplastic resin, layer B can further contain a plasticizer. The plasticizer is not particularly limited. As the plasticizer, carboxylic acid ester- based plasticizers such as a monovalent carboxylic acid ester-based plasticizer and a polyvalent carboxylic acid ester-based plasticizer; polymer plasticizers such as a phosphoric acid ester-based plasticizer or a phosphorous acid ester-based plasticizer, a carboxylic acid polyester-based plasticizer, a carbonate polyester-based plasticizer, and a polyalkylene glycol-based plasticizer, or ester compounds of a hydroxycarboxylic acid with a polyhydric alcohol such as castor oil; and hydroxycarboxylic acid ester- based plasticizers such as an ester compound of a hydroxycarboxylic acid with a monohydric or polyhydric alcohol can also be used. Only one plasticizer can be used alone, or two or more plasticizers can be used in combination.

Examples of the monovalent carboxylic acid ester-based plasticizer include compounds derived by condensation reaction between monovalent carboxylic acids such as butanoic acid, isobutanoic acid, hexane acid, 2-ethylbutanoic acid, heptanoic acid, octyl acid, 2-ethylhexanoic acid, and lauric acid, and polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol, and glycerin.

Specific examples of the compounds include triethylene glycol di-2-diethylbutanoate, triethylene glycol diheptanoate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dioctanoate, tetraethylene glycol di-2-ethylbutanoate, tetraethylene glycol diheptanoate, tetraethylene glycol di-2-ethylhexanoate, tetraethylene glycol dioctanoate, diethylene glycol di-2-ethylhexanoate, PEG # 400 di-2-ethylhexanoate, triethylene glycol mono 2-ethylhexanoate, and a completely or partially esterified product of glycerin or diglycerin with 2-ethylhexanoic acid. Here, PEG #400 represents polyethylene glycol having an average molecular weight of 350 to 450.

Examples of the polyvalent carboxylic acid ester-based plasticizer include compounds derived by condensation reaction between polyvalent carboxylic acids such as adipic acid, succinic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, and trimellitic acid, and alcohols having 1 to 12 carbon atoms such as methanol, ethanol, butanol, hexanol, 2-ethylbutanol, heptanol, octanol, 2-ethylhexanol, decanol, dodecanol, butoxyethanol, butoxyethoxyethanol, and benzyl alcohol. Specific examples of the compounds include dihexyl adipate, di-2-ethylbutyl adipate, diheptyl adipate, dioctyl adipate, di-2-ethylhexyl adipate, di(butoxyethyl) adipate, di(butoxyethoxyethyl) adipate, mono(2- ethylhexyl) adipate, dibutyl sebacate, dihexyl sebacate, di-2-ethylbutyl sebacate, dibutyl phthalate, dihexyl phthalate, di(2-ethylbutyl) phthalate, dioctyl phthalate, di(2-ethylhexyl) phthalate, benzylbutyl phthalate, and didodecyl phthalate.

Examples of the phosphoric acid ester-based plasticizer or the phosphorous acid ester-based plasticizer include compounds derived by condensation reaction between phosphoric acid or phosphorous acid and alcohols having 1 to 12 carbon atoms such as methanol, ethanol, butanol, hexanol, 2-ethylbutanol, heptanol, octanol, 2-ethylhexanol, decanol, dodecanol, butoxyethanol, butoxyethoxyethanol, and benzyl alcohol. Specific examples of the compounds include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tri(butoxyethyl) phosphate, and tri(2- ethylhexyl) phosphite.

Examples of the carboxylic acid polyester-based plasticizer include carboxylic acid polyesters derived by alternating copolymerization of polyvalent carboxylic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, 1 , 2-cyclohexanedicarboxylic acid, 1 , 3- cyclohexanedicarboxylic acid, and 1 , 4-cyclohexanedicarboxylic acid, with polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1 , 2-propylene glycol, 1 ,3- propylene glycol, 1 , 2-butylene glycol, 1 , 3-butylene glycol, 1 , 4-butylene glycol, 1 , 2-pentanediol, 1 , 5- pentanediol, 2, 4-pentanediol, 1 , 2-hexanediol, 1 , 6-hexanediol, 3-methyl-1 ,5-pentanediol, 3-methyl-2, 4- pentanediol, 1 , 2-heptanediol, 1 , 7-heptanediol, 1 , 2-octanediol, 1 , 8-octanediol, 1 , 2-nonanediol, 1 , 9- nonanediol, 2-methyl-1 , 8-octanediol, 1 , 2-decanediol, 1 , 10-decanediol, 1 , 2-dodecanediol, 1 , 12- dodecanediol, 1 , 2-cyclohexanediol, 1 , 3-cyclohexanediol, 1 , 4-cyclohexanediol, 1 , 2- bis(hydroxymethyl)cyclohexane, and 1 , 3-bis(hydroxymethyl)cyclohexane, and 1 , 4- bis(hydroxymethyl)cyclohexane; polymers of hydroxycarboxylic acid (hydroxycarboxylic acid polyester) such as aliphatic hydroxycarboxylic acids (for example, glycolic acid, lactic acid, 2-hydroxybutyric acid, 3- hydroxybutyric acid, 4-hydroxybutyric acid, 6-hydroxyhexanoic acid, 8-hydroxyhexanoic acid, 10- hydroxydecanoic acid, and 12-hydroxydodecanoic acid) and aromatic ring-containing hydroxycarboxylic acid [for example, 4-hydroxybenzoic acid and 4-(2-hydroxyethyl)benzoic acid]; and carboxylic acid polyesters derived by ring-opening polymerization of lactone compounds such as aliphatic lactone compounds (for example, y-butyrolactone, y-valerolactone, d-valerolactone, p-methyl-6-valerolactone, d- hexanolactone, e-caprolactone, and lactide) and aromatic ring-containing lactone compounds (for example, phthalide). The terminal structure of the carboxylic acid polyester is not particularly limited and can be a hydroxyl group or a carboxyl group, an ester bond formed by reacting the terminal hydroxyl group with a monovalent carboxylic acid, or an ester bond formed by reacting the terminal carboxyl group with a monohydric alcohol.

Examples of the polyester carbonate plasticizer include carbonate polyesters derived by alternating copolymerization through ester exchange reaction of polyhydric alcohols such as ethylene glycol, diethylene glycol, methylene glycol, tetraethylene glycol, 1 , 2-propylene glycol, 1 , 3-propylene glycol, 1 , 2- butylene glycol, 1 , 3-butylene glycol, 1 , 4-butylene glycol, 1 , 2-pentanediol, 1 , 5-pentanediol, 2,4- pentanediol, 1 , 2-hexanediol, 1 , 6-hexanediol, 3-methyl-1 , 5-pentanediol, 3-methyl-2, 4-pentanediol, 1 , 2- heptanediol, 1 , 7-heptanediol, 1 , 2-octanediol, 1 , 8-octanediol, 1 , 2-nonanediol, 1 , 9-nonanediol, 2-methyl- 1 , 8-octanediol, 1 , 2-decanediol, 1 ,10-decanediol, 1 , 2-dodecanediol, 1 , 12-dodecanediol, 1 , 2- cyclohexanediol, 1 , 3-cyclohexanediol, 1 , 4-cyclohexanediol, 1 , 2-bis(hydroxymethyl)cyclohexane, 1 , 3- bis(hydroxymethyl)cyclohexane, and 1 , 4-bis(hydroxymethyl))cyclohexane with carbonate esters such as dimethyl carbonate and diethyl carbonate. The terminal structure of the carbonate polyester compounds is not particularly limited and is preferably a carbonate ester group or a hydroxyl group.

Examples of the polyalkylene glycol plasticizer include polymers derived by ring-opening polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, and oxetane, using a monohydric alcohol, a polyhydric alcohol, a monovalent carboxylic acid, or a polyvalent carboxylic acid as the polymerization initiator.

Examples of the hydroxycarboxylic acid ester-based plasticizers include monohydric alcohol esters of hydroxycarboxylic acids, for example, methyl ricinoleate, ethyl ricinoleate, butyl ricinoleate, methyl 6- hydroxyhexanoate, ethyl 6-hydroxyhexanoate, and butyl 6-hydroxyhexanoate; polyhydric alcohol esters of hydroxycarboxylic acids, for example, ethylene glycol di(6-hydroxyhexanoic acid) ester, diethylene glycol di(6-hydroxyhexanoic acid) ester, triethylene glycol di(6-hydroxyhexanoic acid) ester, 3-methyl-1 ,5- pentanediol di(6-hydroxyhexanoic acid) ester, 3-methyl-1 , 5-pentanediol di(2-hydroxybutyric acid) ester, 3-methyl-1 , 5-pentanediol di(3-hydroxybutyric acid) ester, 3-methyl-1 , 5-pentanediol di(4-hydroxybutyric acid) ester, triethylene glycol di(2-hydroxybutyric acid) ester, glycerin tri(ricinoleic acid) ester, and L- tartaric acid di(1 -(2-ethylhexyl)); and compounds in which some groups derived from the hydroxycarboxylic acid in castor oil or a polyhydric alcohol ester of a hydroxycarboxylic acid are replaced with groups derived from the carboxylic acid containing no hydroxyl group or with hydrogen atoms. As these hydroxycarboxylic acid esters, those derived by conventionally known methods can be used.

The plasticizers are preferably, from the viewpoint of easily increasing the compatibility with polyvinyl butyral resin, or low migration properties or no-migration properties to other layers, ester-based plasticizers or ether-based plasticizers which have a fusion point of 30°C or less and a hydroxyl value of 15 mg KOH/g or more and 450 mg KOH/g or less, or ester-based plasticizers or ether-based plasticizers which are non-crystalline and have a hydroxyl value of 15 mg KOH/g or more and 450 mg KOH/g or less. The "non-crystalline" means that no fusion point is observed at a temperature of -20°C or more. When a fusion point is observed, the fusion point is preferably 15°C or less, and particularly preferably 0°C or less. The hydroxyl value is, regardless of whether the fusion point is observed or not observed, more preferably 30 mg KOH/g or more, particularly preferably 45 mg KOH/g or more, more preferably 360 mg KOH/g or less, and particularly preferably 280 mg KOH/g or less. Examples of the ester-based plasticizers include polyesters (such as the carboxylic acid polyester-based plasticizers and carbonate polyester-based plasticizers) and hydroxycarboxylic acid ester compounds (such as the hydroxycarboxylic acid ester-based plasticizers) that satisfy the above-mentioned limitations, and examples of the ether-based plasticizers include polyether compounds that satisfy the above-mentioned limitations (such as the polyalkylene glycol-based plasticizers). The content of the plasticizer in layer B is preferably 50 parts weight or less, more preferably 45 parts weight or less, and particularly preferably 40 parts weight or less relative to 100 parts weight of the polyvinyl acetal resin. When the content of the plasticizer is not more than the upper limit, the laminated glass comprising the derived interlayer film tends to have excellent impact resistance. The lower limit of the content of the plasticizer is not particularly limited. The content of the plasticizer in layer B can be, for example, 10 parts weight or more, 5 parts weight or more, or 0 parts weight relative to 100 parts weight of the thermoplastic resin constituting the B layer.

Because compounds having a hydroxyl group have high compatibility with a polyvinyl acetal resin and low migration properties to adjacent layers (for example, layer A), the sound insulation of the laminated glass comprising the derived interlayer film can be stably exhibited, thus, as the plasticizer, compounds having a hydroxyl group are preferably used. Examples of the plasticizer compound having a hydroxyl group include polyester polyols manufactured by KURARAY CO., LTD "Kuraray Polyol P-510" and "Kuraray Polyol P-1010".

The content of the plasticizer compound having a hydroxyl group based on the total amount of the plasticizer contained in layer B is preferably 10 wt% or more, more preferably 15 wt% or more, particularly preferably 20 wt% or more, preferably 100 wt% or less, more preferably 90 wt% or less, and particularly preferably 80 wt% or less.

When an ionomer resin is used as the second thermoplastic resin contained in the B layer, the ionomer resin is not particularly limited. Examples of the ionomer resin include resins having a structural unit derived from ethylene and a structural unit derived from a, b-unsaturated carboxylic acid in which at least a part of the structural unit derived from a, b-unsaturated carboxylic acid is neutralized by a metal ion. Examples of the a, b -unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, monomethyl maleate, monoethyl maleate, and maleic anhydride, and acrylic acid or methacrylic acid is particularly preferable. Examples of the metal ion include sodium ions. In the ethylene-a, b-unsaturated carboxylic acid copolymer as the base polymer, the content of the structural unit derived from the a, b- unsaturated carboxylic acid is preferably 2 wt% or more, more preferably 5 wt% or more, and preferably 30 wt% or less, and more preferably 20 wt% or less. From the viewpoint of availability, ionomer resins of ethylene-acrylic acid copolymers and the ionomer resins of ethylene-methacrylic acid copolymers are preferable. Particularly preferable examples of the ethylene ionomer resins include a sodium ionomer resin of ethylene-acrylic acid copolymer and a sodium ionomer resin of ethylene-methacrylic acid copolymer. Only one ionomer resin can be used alone, or two or more ionomer resins can be used in combination. Layer B can also contain a resin other than the polyvinyl acetal resin and the ionomer resin. From the viewpoint of easily maintaining high adhesiveness to glass, the content of the polyvinyl acetal resin or the ionomer resin in the resin material constituting layer B is preferably 40 wt% or more, more preferably 50 wt% or more, more preferably 60 wt% or more, particularly preferably 80 wt% or more, and most preferably 90 wt% or more.

In a preferable embodiment of the interlayer film for use in laminated glass of the present invention, the resin material constituting layer B consists of an ionomer resin. Also, in the case where an ionomer resin is used as the resin material constituting layer B, by using multiple A layers having excellent sound insulation, as defined in the present invention, and employing a structure in which the layer C as described below is inserted between the multiple A layers, an interlayer film having excellent sound insulation is enabled.

The resin material constituting layer B can further contain antioxidants, ultraviolet radiation absorbers, photostabilization agents, anti-blocking agents, pigments, dyes, functional inorganic compounds, a heat shield material or the like as other components, as needed.

For the antioxidant, ultraviolet radiation absorbers, photostabilization agents, the anti-blocking agents, or the heat shield material, the same materials as those described in the description of the layer A above can be used, and the suitable agents, materials, or addition amounts in layer B can be the same as or different from the suitable agents, materials, or addition amounts in layer A.

Layer B can be a layer which controls the adhesiveness of the derived interlayer film to glass or the like, as needed. Examples of the method of controlling the adhesiveness include the methods of adding an additive used as an adhesiveness regulator for use in laminated glass to the resin material constituting the B layer, and the method of adding various additives for adjusting adhesiveness to the resin material constituting the B layer. By employing such a method, an interlayer film for use in laminated glass containing an adhesiveness regulator and/or various additives for adjusting adhesiveness is enabled.

As the adhesiveness regulator, for example, those disclosed in WO-A-03/033583 can be used. An alkali metal salt or an alkaline earth metal salt is preferably used, and examples thereof include potassium salts, sodium salts, magnesium salts and the like. Examples of the salts include salts of organic acids such as carboxylic acid (for example, octanoic acid, hexanoic acid, butyric acid, acetic acid, and formic acid); and salts of inorganic acids such as hydrochloric acid and nitric acid. When plasticizers containing hydroxyl groups are used, salts of 6 - 12 carbon carboxylic acids are preferably employed from the perspective of controlling the reproducibility of the adhesiveness of the interlayer film to glass, and examples thereof include, magnesium salts of hexanoic acid, 2-ethylheptanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, 2-ethylhexanoic acid, 2- ethyl butyric acid, 2-propylheptanoic acid, 2, 2-dimethylbutyric acid, 2, 2-dimethylpentanoic acid, 2, 2- dimethylhexanoic acid, 2, 2-dimethylhexanoic acid, 2, 2-dimethylheptanoic acid, 2, 2-dimethyloctanoic acid, 2, 2-dimethylnonanoic acid, 2, 2-dimethyldecanoic acid, neodecanoic acid, neopentanoic acid, and the like.

The optimum addition amount of the adhesiveness regulator depends on the adhesiveness regulator used. Generally, the addition amount is preferably adjusted so that the adhesion force of the derived interlayer film to glass is three or more and 10 or less in the Pummel Test (described in WO-A-03/033583 and the like), and is preferably adjusted so that the adhesion force of the derived interlayer film to glass is three or more and six or less particularly when high penetration resistance is required. When a high glass scattering prevention property is required, the adhesion force is preferably adjusted to seven or more and 10 or less. When a high glass scattering prevention property is required, no addition of an adhesiveness regulator is also a useful method.

In the interlayer film for use in laminated glass of the present invention, the thickness of one layer B is preferably 100 pm or more, and preferably 2.0 mm or less. When the thickness of layer B is less than 100 pm, and for example, the surface has embossing applied thereto, the form of that embossing is transferred to layer A, and that shape remains even after the formation of laminated glass which may give rise to the problem of the generation of optical distortion. When the thickness of anyone layer of layer B is thicker than 2.0 mm, the flexural rigidity of the interlayer film is elevated, it may give rise to problems of a lack of reliability onto a roll, or problems with a lack of following the curvature in respect of glass. The thickness of any layer of layer B is preferably equal to or greater than 150 pm, more preferably equal to or greater than 200 pm, and most preferably less than or equal to 1 .5 mm. When the thickness of any layer of layer B is within the above described range between the upper limit value in the lower limit value, the cited problems cannot easily occur.

Moreover, when the thickest layer of any one of layer B and layer C is equal to or greater than 900 pm, while the soundproofing is increased to a desirable level, when the thickness is too great, the flexural rigidity of the interlayer film may become excessive, even if the tensile storage elasticity modulus is low, and may give rise to problems of the above described laminates or adhesion. Therefore, the thickness of any one layer of either layer B or layer C must be equal to or greater than 900 pm and less than or equal to 2.0 mm, preferably 950 pm to 1 .8 mm. Moreover, the total thickness of layer B and layer C (the total of the total thickness of layers be and the total thickness of layer C) is preferably less than 2.5 mm. The thickness of notable layers of layer B maybe the same or different. The thickness is measured as the total thickness. Moreover, multiple layers of layer B may be configured from the same resin material or configured from different resin materials.

The interlayer film for use in laminated glass of the present invention comprises layer C disposed to separate multiple A layers. Layer C is a layer comprising the third thermoplastic resin. The resin material configuring layer C, while being different than the resin material configuring layer A, may be the same or different than the resin material configuring layer B. “A resin material which is different from the resin material configuring layer B” means a resin material other than the same resin material configuring layer B. For example, the second thermoplastic resin comprising layer B and the third thermoplastic resin comprising layer C may both be polyvinyl butyral resins, and if the resin material configuring layer B is not identical to the resin material configuring layer C, it may be said that layer C is configured from a resin material which is different from the resin material configuring layer B. As a specific example, if the resin material configuring layer B is a resin material comprised of 50 - 65 wt% of polyvinyl butyral resin Xi and 35 - 50 wt% of the plasticizer Yi, then the resin material configuring layer C may be a resin material comprised of 70 - 90 wt% of polyvinyl butyral resin Xi and 10 - 30 wt% of the plasticizer Yi. Moreover, for example, if the resin material configuring layer B is resin material comprised of polyvinyl butyral resin X2 with 1 - 10 mol% of vinyl alcohol units, the resin material configuring layer C may be a resin material comprised of polyvinyl butyral resin Xs with 10.1 - 30 mol% of vinyl alcohol units.

From the perspective of avoiding variation in the soundproofing as a result of temperature changes which affect the amount of plasticizer existing in each layer, as a result of the temperature dependent migration of the plasticizer between adjacent layers, either one of layer B or layer C preferably is configured from a resin material which effectively does not comprise plasticizer. For example, in respect of the resin materials configuring either one of layer B and layer C, the content of plasticizer is preferably less than or equal to 10 wt%, and more preferably less than or equal to five wt%, and even more preferably less than or equal to one wt% or even 0 wt%.

The resin material configuring layer C preferably either has a peak at which the tan d, measured by performing a complex shear viscosity test under the conditions of a frequency of 1 Hz according to JIS K 7244-10: 2005, is not maximum in the range from -30°C or more and 10°C or less, or the tan d is less than 1 .5. The resin material configuring layer C is either comprised of the third thermoplastic resin, or a resin composition containing the third thermoplastic material.

The resin material configuring layer C has a tensile storage elasticity modulus measured by performing the dynamic viscoelasticity test under the conditions of a frequency of 0.3 Hz and a temperature of 20°C according to JIS K 7244-4:1999 of equal to or greater than 20 MPa and less than or equal to 1 .2 GPa.

The greater this tensile storage elasticity module is in excess of 1 .2 GPa, it is difficult to follow the curvature of the transparent substrate, and the desired soundproofing is difficult to derive when less than 20 MPa. The tensile storage elasticity modulus of the resin material configuring layer C is preferably equal to or greater than 30 MPa, more preferably equal to or greater than 100 MPa, and preferably less than or equal to 1 .1 GPa, and more preferably less than or equal to 1 .0 GPa. The above described problems with the degree of following of the curved surface or the soundproofing cannot easily occur when that tensile storage elasticity modulus is in the range between that lower limit value and that upper limit value.

As the method of adjusting the above described tensile storage elasticity modulus, for example, the methods of the selection of the third thermoplastic resin, or the type of plasticizer, or the adjustment of the content thereof may be suggested.

There are no limitations in particular on the third thermoplastic resin as long as the resin materials configuring layer C satisfy the above described tensile storage elasticity modulus conditions. As the third thermoplastic resin, for example, polystyrene resins, acrylate resins, phenolic resins, vinyl chloride resins, AS resins, polycarbonate resins, polyester resins, ABS resins, acetal resins, polyamide resins, ionomer resins or polyvinyl acetal resins may be employed. From the perspective of transparency, cost or the ease of ductile rupture of the interlayer film, the third thermoplastic resin of layer C preferably includes acrylate resins, ionomer resins or polyvinyl acetal resins.

The acrylate resins which may be employed as the third thermoplastic resin are not particularly prescribed as long as they are resin materials satisfying the above described tensile storage elasticity modulus conditions.

The acrylic resin is a polymer of one of the monomers as exemplified below, or a copolymer of two or more of the monomers exemplified below: methyl methacrylate, methacrylic acid, acrylic acid, benzyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, stearyl (meth)acrylate, glycidyl (meth)acrylate, hydroxypropyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, acrylic (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2- (meth)acroyloxyethyl succinate, 2-(meth)acroyloxyethyl maleate, 2-(meta)acroyloxyethyl phthalate, 2- (meth)acrioyloxyethyl hexahydrophthalate, pentamethylpiperidyl (meth)acrylate, tetramethylpiperidyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate and the like. The acrylic resin can further contain a monomer copolymerizable with the above-mentioned monomers as a structural component. Such a copolymerizable monomer can be a monofunctional monomer, that is, a compound having one polymerizable carbon-carbon double bond in the molecule, or can be a polyfunctional monomer, that is, a compound having at least two polymerizable carbon-carbon double bonds in the molecule. When the acrylic resin contains a copolymerizable monomer as a structural component, either one copolymerizable monomer can be contained alone or two or more copolymerizable monomers can be contained.

Examples of the monofunctional monomer include aromatic alkenyl compounds such as styrene, a- methylstyrene, and vinyltoluene; alkenyl cyanides such as acrylonitrile and methacrylnitrile; and acrylic acid, methacrylic acid, maleic anhydride, and N-substituted maleimide. Examples of the polyfunctional monomer include polyunsaturated carboxylic acid esters of a polyhydric alcohol such as ethylene glycol dimethacrylate, butanediol dimethacrylate, and trimethylolpropane triacrylate; alkenyl esters of an unsaturated carboxylic acid such as allyl acrylate, allyl methacrylate, and allyl cinnamate; polyalkenyl esters of a polybasic acid such as diallyl phthalate, diallyl maleate, triallyl cyanurate, and triallyl isocyanurate; and aromatic polyalkenyl compounds such as divinylbenzene.

From the viewpoint of easily improving the environmental resistance (warp due to moisture absorption) of the acrylic resin, the acrylic resin is preferably a methyl methacrylate-styrene copolymer. As the methyl methacrylate-styrene copolymer, those having 30 to 95 wt% of methyl methacrylate unit and 5 to 70 wt% of styrene unit based on all the monomer structural units is usually used, those having 40 to 95 wt% of methyl methacrylate unit and 5 to 60 wt% of styrene unit based on all the monomer structural units is preferably used, and those having 50 to 90 wt% of methyl methacrylate unit and 10 to 50 wt% of styrene unit based on all the monomer structural units is more preferably used.

The acrylic resin that can be used in the present invention can be prepared by polymerizing the above- mentioned monomer components by a known method such as suspension polymerization, emulsion polymerization, and bulk polymerization. At that time, from the viewpoint of easily adjusting the glass transition temperature of the derived acrylic resin to a desired temperature or from the viewpoint of easily obtaining a viscosity that provides suitable moldability during production of an interlayer film, a chain transfer agent is preferably used during polymerization. The amount of the chain transfer agent can be appropriately determined depending on the type of the monomer component, the composition of the acrylic resin to be prepared, or the like.

There is no particular prescription for the ionomer resin to be used, as long as it is a resin material satisfying the previously outlined tensile storage elasticity modulus conditions, and those which were explained for layer B may be employed. The polyvinyl acetal resins and plasticizers explained earlier for layer B may be employed.

Therefore, in preferred embodiments, the plasticizers which may be contained in layer C are ester type plasticizers or ether type plasticizers with the fusion point at or below 30°C, a hydroxyl group value of 15 mg KOH/g or more and less than or equal to 450 mg KOH/g.

The content amount of the plasticizer may be adjusted appropriately as needed in order to keep the tensile storage elasticity modulus of the resin material configuring layer C within the desired range. In general, the content of the plasticizer is preferably less than or equal to 55 parts weight with respect to 100 parts weight of the polyvinyl acetal resin, and more preferably less than or equal to 40 parts weight, and preferably at least 15 parts weight, more preferably at least 20 parts weight.

The third thermoplastic resin configuring layer C layer can further contain antioxidants, ultraviolet radiation absorption agents, photostabilizers, anti-blocking agents, pigments, dyes, functional inorganic compounds, heat shield materials, adhesion force regulators or the like as other components, as needed.

For the antioxidant, the ultraviolet radiation absorber, the light stabilizer, the anti-blocking agent, or the heat shield material, the same materials as those described in the description of layer A or layer B above can be used, and the suitable agents, materials, or addition amounts in the C layer can be the same as or different from the suitable agents, materials, or addition amounts in the layers A or B.

Examples of the adhesion force regulator include polyolefins having an adhesive functional group such as a carboxyl group, a derivative group of a carboxyl group, an epoxy group, a boronic acid group, a derivative group of a boronic acid group, an alkoxyl group, and a derivative group of an alkoxyl group.

There are materials in the heat shielding materials which cause photo deterioration as a result of ultraviolet radiation, but if heat shielding materials are plentiful in layer C positioned relatively centrally in respect of the interlayer film cross-section, and so if a configuration wherein ultraviolet radiation absorption agents are amply included in layer A or layer B which are positioned on the outer side of layer C, the suppression of the deterioration of the heat shielding material is enabled.

The thickness of one layer of layer C is equal to or greater than 100 pm and less than or equal to 2.0 mm. It is difficult for the improved soundproofing effect to be exhibited when the thickness of one layer of layer C is less than 100 pm. When the thickness of one layer of layer C is more than 2.0 mm, the flexural rigidity of the interlayer film becomes elevated, and may generate problems in respect of the reliability to rolls or difficulties in following the curvature in respect of a transparent substrate, such as glass and the like. The thickness of one layer of layer C is preferably equal to or greater than 150 pm, and more preferably equal to or greater than 200 pm, and is preferably less than or equal to 1 .5 mm. It is unlikely that there would be problems with improving the soundproofing or following the curvature as described above when the thickness of one layer of layer C is in the range between the above specified lower limit value and upper limit value.

When there are multiple layers of C, they may all have the same thickness, or the thickness thereof may differ. The thickness is measured as the aggregate thickness. Moreover, multiple layers of C may be configured from the same resin material or may be configured from different resin material. nterlayer film for use in laminated glass>

The method for producing the interlayer film for use in laminated glass of the present invention is not particularly limited.

The interlayer film of the present invention may be manufactured by known film forming methods (for example, the extrusion method, the calendar method, the pressing method, the casting method, or the inflation method), manufacturing the A layers from the resin material constituting layer A, and manufacturing layer B from the resin material configuring layer B, and manufacturing layer C from the resin material configuring layer C, and manufacturing them by laminating using, for example, press molding and the like thereof with any other required layers (later referred to as layer D), such that they may be manufactured by means of co-extruding layer A, layer B, layer C and, if required, layer D (when layer D is comprised of a resin material).

Even among the known film manufacturing methods, the method of manufacturing the interlayer film using extruders in particular is preferred. The temperature of the resin at the time of extrusion (the temperature of the resin material) is preferably equal to or greater than 150°C and more preferably equal to or greater than 170°C, and preferably less than or equal to 250°C, and more preferably less than or equal to 230°C. When the resin temperature at the time of extrusion is in the range between that lower limit value and upper limit value, it is difficult for deterioration of the resin and the like to be generated because of the difficulty of the breakdown of the resin on the like included in the resin materials, and stable spewing from the extruder is enabled. In order to efficiently eliminate volatile materials, the volatile materials are preferably eliminated from the vent port of the extruder using reduced pressure.

The thickness of one layer each of layer A, layer B and layer C is as described above.

Of the interlayer film for use in laminated glass in the present invention may be determined appropriately depending on the usage purposes thereof. The intermediate film for use in laminated glass, for example, other than the configuration represented in figure 1 (layer B/layer a/layer C/layer A/layer B), may be a laminated configuration including additional layers A and C such as layer B/layer A/layer C/layer A/layer C/layer A/layer B.

The interlayer film for use in laminated glass of the present invention may include one or more layers other than layer a, layer B and layer C (hereafter referred to as layer D). As nonlimiting embodiments of the laminated configuration when a layer D is included in the interlayer film for use in laminated glass, there are

Layer B/layer A/layer D/layer C/layer A/layer B, layer B/layer A/layer C/layer A/layer B/layer D, layer B/layer D/layer A/layer D/layer C/layer A/layer B, layer B/layer D/layer A/layer C/layer A/layer D/layer B, layer B/layer D/layer A/layer C/layer A/layer B/layer D/, layer D/layer B/layer A/layer C/layer A/layer B/layer D, layer B/layer A/layer D/layer B/layer D/layer C/layer A/layer B, layer D/layer B/layer A/layer B/layer D/layer C/layer A/layer B, layer D/layer B/layer A/layer D/layer B/layer D/layer C/layer A/layer B, layer D/layer B/layer D/layer A/layer D/layer B/layer D/layer C/layer B/layer A/layer B etc. may be suggested. In respect of the previous described laminated configurations, when there are two or more layers of layer A, layer B, layer C and/or layer D included, while the materials constituting each of the layers A, layers B, layer C and layers D (the resin material when the material contains resin) and the thicknesses thereof may be the same or different, but when the thickness is 900 pm or more, it is preferred that there be just one layer.

The D layer that can be included in the interlayer film for use in laminated glass of the present invention can be a layer composed of a known resin. As the resin constituting the D layer, for example, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, acrylic resin, polyamide, polyacetal, polycarbonate, polyethylene terephthalate among polyesters, polybutylene terephthalate, cyclic polyolefin, polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyethersulfone, polyarylate, liquid crystal polymer, polyimide or the like can be used. The D layer can contain additives such as plasticizers, antioxidants, ultraviolet radiation absorbers, light stabilizers, anti-blocking agent, pigment, dyes, and heat shield materials, as needed, and a layer such as an inorganic multilayer and a metal conductive layer can be formed on at least a part of the D layer. Irregularities are preferably formed on the surface of the interlayer film for use in laminated glass of the present invention by a conventionally known method such as melt fracture and embossing. The shape of the irregularities is not particularly limited, and a conventionally known one can be employed.

The thickness of the interlayer film for use in laminated glass of the present invention is preferably 1 .6 mm or more, more preferably 1 .7 mm or more, and preferably 3.6 mm or less, more preferably 3.2 mm or less, and particularly preferably 2.4 mm or less. When the thickness is preferably not less than the lower limit, a structure of the laminated glass excellent in sound insulation can be easily obtained. When the thickness is preferably not more than the upper limit, the weight of the entire laminated glass can be reduced and the cost of the interlayer film can be easily reduced.

Generally, when the transparent substrates (for example, glass) of the outermost layers that sandwich the interlayer film for use in laminated glass becomes thin, the loss factor tends to be low. Thus, a structure in which the thicknesses of the two transparent substrates of the outermost layers are different and the cross section of the laminated glass is asymmetric has a decreased loss factor compared to a structure in which the thicknesses of the two transparent substrates of the outermost layers are the same and the cross section of the laminated glass is symmetrical, even when the thicknesses of the laminated glasses in both structures are the same. Meanwhile, in the laminated glass for an automobile windshield, the thickness of the glass outside the automobile is generally limited to about 1 .8 mm or more to impart chipping resistance against flying stones. Thus, although the glass inside the automobile needs to be thin to reduce the weight of the laminated glass, in such a case, there is a problem of the decrease in the loss factor as described above. The interlayer film for use in laminated glass according to the present invention is useful as a method for solving such a problem.

For the interlayer film for use in laminated glass of the present invention, a laminated glass derived by sandwiching the interlayer film for use in laminated glass between two sheets of float glass having a length of 300 mm, a width of 25 mm, and a thickness of 1 .9 mm and pressure bonding them under the conditions of a temperature of 140°C, a pressure of 1 MPa, and 60 minutes preferably has a loss factor at the secondary resonance frequency measured by damping test of the laminated glass according to a center excitation method at 20°C of 0.58 or more, more preferably 0.60 or more, and particularly preferably 0.62 or more. In the present invention, the loss factor at 20°C, which is considered to be a temperature at which the interlayer film is normally used, is employed as an index for sound insulation.

The laminated glass of the present invention comprises sandwiching the interlayer film for use in laminated glass of the present invention between the two transparent substrates. As described above, by using the interlayer film for use in laminated glass of the present invention, a laminated glass having excellent sound insulation, in particular, sound insulation in a frequency range of 2,000 Hz to 10,000 Hz can be obtained. Thus, the interlayer film for use in laminated glass of the present invention can be suitably used for the windshield for vehicles (for example, automobiles), the side window for a vehicle, the sunroof for a vehicle, the rear window for a vehicle, the glass for a head-up display or the like. Thus, in a preferable embodiment of the present invention, the laminated glass is the windshield for a vehicle, the side window for a vehicle, the sunroof for a vehicle, the rear window for a vehicle, or the glass for a head up display. The vehicle in the present invention means a train, an electric train, an automobile, a ship, an aircraft or the like. The interlayer film for use in laminated glass of the present invention can be employed to advantage in class for use in architecture (for example, window glass for use in buildings).

When a laminated glass comprising two transparent substrates sandwiched between the two transparent substrates is adapted to glass for a head up display, the shape of the cross section of the interlayer film is preferably a shape in which one end face side is thick and the other end face side is thin. In that case, the shape of the cross section can be an entirely wedge-shaped shape in which the thickness gradually decreases from one end face side to the other end face side, can be a partially wedge-shaped shape in which the thickness is same from one end face to an arbitrary position between the end face and the other end face, and gradually decreases from the arbitrary position to the other end face, or can be an arbitrary shape regardless of the position as long as it does not cause problems in production. The cross- section thicknesses of all the layers can change or the cross-section thicknesses of only some layers can change.

In the laminated glass of the present invention, two transparent substrates are usually used in the outermost position. The transparent substrate is not particularly limited, and for example, an inorganic glass, an organic glass, or a combination thereof can be used. Examples of the inorganic glass include a float plate glass, a polished plate glass, a template glass, a mesh plate glass, and a heat ray absorbing plate glass. Examples of the material constituting the organic glass include an acrylic resin (for example, polymethyl methacrylate resin) and a polycarbonate resin. The transparent substrate can be colorless, colored, transparent, or non-transparent.

In one embodiment, at least one sheet of the outermost layer of laminated glass which is a two sheet transparent substrate is preferably inorganic glass. As an example of this type of embodiment, the laminated glass may embody the use of the laminated glass in vehicles. When the laminated glass is employed in vehicles, of the two sheets of transparent substrate which is the outermost layer, at least the transparent substrate on the outer side of the vehicle is preferably inorganic glass. The thickness of the transparent substrate is not particularly limited, and is preferably 100 mm or less.

The interlayer film of the present invention has excellent sound insulation, thus high sound insulation is exhibited even when a thinner transparent substrate is used, thereby, the weight reduction of the laminated glass can be realized From the viewpoint of weight reduction, the thickness of at least one transparent substrate is preferably 3.0 mm or less, more preferably 2.5 mm or less, further preferably 2.0 mm or less, and particularly preferably 1 .8 mm or less. In particular, when the thickness of one transparent substrate is 1 .8 mm or more, the thickness of the other transparent substrate is 1 .8 mm or less, and the difference in thickness between the two transparent substrates is 0.2 mm or more, a laminated glass in which film thinning and weight reduction are realized without impairing flexural strength can be produced. The difference in thickness between the two sheets of transparent substrate is preferably equal to or greater than 0.5 mm, and may be equal to or greater than 1 .0 mm.

In a preferred embodiment, the laminated glass of the present invention sandwiches the interlayer film for use in laminated glass of the present invention between two transparent substrates, and at least one of the sheets of the transparent substrates is inorganic glass with the thickness of 1 .2 - 3.0 mm.

In a preferable embodiment, the laminated glass of the present invention sandwiches the interlayer film for use in laminated glass of the present invention between two transparent substrates, and at least one of the sheets of the transparent substrates is inorganic glass with the thickness of 3.0 - 10.0 mm.

Thus, as an interlayer film used for the laminated glass for an automobile, the interlayer film for use in laminated glass of the present invention can be suitably used In laminated glass configuring equal thicknesses of transparent substrates on the vehicle interior side and the vehicle exterior side, but even in that type of situation, an interlayer film with high soundproofing is advantageously enabled by means of the present invention.

The soundproofing of the laminated glass, as recited in the explanation of the interlayer film for use in laminated glass above, can have the loss factor thereof assessed by deriving it by means of a damping test using the central excitation method, and the higher the loss factor of the laminated glass, the higher the soundproofing of the laminated glass may be said to be.

The loss factor at the secondary resonant frequency of the laminated glass of the present invention, as measured in a damping test of the laminated glass by means of the central excitation method at 20°C, is preferably equal to or greater than 0.58, more preferably equal to or greater than 0.60, and most preferably equal to or greater than 0.62.

[0129] <Methods for producing the laminated glass>

The laminated glass of the present invention can be produced by a conventionally known method. Examples of such a method include a method in which a vacuum laminator device is used, a method in which a vacuum bag is used, a method in which a vacuum ring is used, and a method in which a nip roll is used. A method in which an autoclave step is additionally performed, after temporary pressure bonding, can also be performed.

In the method in which a vacuum laminator device is used, for example, lamination is performed at a temperature of 100°C or more and 200°C or less (in particular, 130°C or more and 170°C or less) under a reduced pressure of 1 c 10^-5 MPa or more and 3 c 10^-2 MPa or less using a known devices used in the production of a solar cell.

The method in which a vacuum bag or a vacuum ring is used is, for example, described in European Patent 1235683, and lamination is performed, for example, at a temperature of 130°C or more and 145°C or less under a pressure of about 2 c 10² MPa.

Examples of the method in which a nip roll is used include a method in which the first temporary pressure bonding is performed at a temperature equal to or lower than the flow initiation temperature of the polyvinyl acetal resin, and then pressure bonding or temporary pressure bonding is further performed under conditions closer to the flow starting temperature. Specific examples thereof include a method in which heating to 30°C or more and 100°C or less is performed with an infrared heater and the like, then degassing is performed with a roll to perform temporarily pressure bonding, further heating to 50°C or more and 150°C or less is performed, and then pressure bonding or temporarily pressure bonding is performed with a roll.

The autoclave processing additionally performed after temporary pressure bonding is, for example, performed under a pressure of 1 MPa or more and 15 MPa or less at a temperature of 120°C or more and 160°C or less for 0.5 hour or more and 2 hours or less depending on the thickness and composition of the laminated glass.

EMBODIMENTS

Hereinafter, although the present invention will be specifically described with reference to Embodiments and Comparative Embodiments the present invention is not limited to these Embodiments. In the following Embodiments, "%" means "wt%" unless otherwise specified. In the following Embodiments and Comparative Embodiments, as the polyvinyl butyral (PVB) resin, a product derived by acetalizing polyvinyl alcohol having the same viscosity-average degree of polymerization as a target viscosity-average degree of polymerization (a viscosity-average degree of polymerization measured based on JIS K 6726 "Testing method for polyvinyl alcohol") with acetalization of n-butyraldehyde using hydrochloric acid as the catalyst was used.

Measurement Methods and Assessment methods

1 . Tan d peak temperature and tan d peak height of resin material constituting layer A

A single-layer sheet having a thickness of 1 .0 mm was prepared by pressurizing a resin material constituting layer A (a hydrogenated product of a block copolymer, hereinafter also referred to as "a hydrogenated block copolymer") at a temperature of 230°C and a pressure of 10 MPa for 3 minutes. This single-layer sheet was cut into a disc shape and used as a test sheet.

The temperature of the peak at which the tan d of the resin material constituting layer A is maximum and the height of the tan d peak were determined by performing the complex shear viscosity test under a condition of a frequency of 1 Hz according to JIS K7244-10: 2005.

2. Content of block polymer (a)

The resin material constituting layer A (the hydrogenated block copolymer) was dissolved in CDCI3 to measure a ¹H-NMR spectrum [Instrument: JNM-Lambda 500 (manufactured by JEOL Ltd.), measurement temperature: 50°C], and the content of the block polymer (a) was calculated from the peak intensity derived from styrene.

3. Glass transition temperature of the resin materials constituting layer A

The glass transition temperatures of the monomer configuring block polymer (a) which is the hydrogenated block copolymer used in the embodiments and comparative embodiments , and the glass transition temperature of the monomers configuring block polymer (b) are presented. Thus, as the glass transition temperature of the hydrogenated copolymer blocks, the glass transition temperature of the polymer blocks (a) included in the hydrogenated block copolymer and the glass transition temperature of the polymer block (b) were determined by performing differential scanning calorimetry (DSC, manufactured by Seiko Instruments & Electronics Ltd.). In the measurement, the temperature was increased from -120°C to 150°C at a heating rate of 10°C/min, and the temperature at an inflection point of the measurement curve was read, and taken as the glass transition temperature of each block. 4. Measurement of tensile storage elasticity modulus of resin material constituting Layer B or C layer

The resin material constituting layer B or the C layer was pressurized at a temperature of 230°C and a pressure of 10 MPa for 10 minutes to produce samples having a thickness of 0.8 mm. These samples were cut into pieces each having a width of 3 mm, which were used as samples for dynamic viscoelasticity measurement. The tensile storage elasticity modulus at 0°C was determined by performing the dynamic viscoelasticity tests on these samples for measurement according to JIS K7244-4:1999 under the conditions of a frequency of 0.3 Hz, to derive the tensile storage elasticity modulus at 20°C.

5. Fusion point of the plasticizer the fusion point of the plasticizer was measured using DSC (differential scanning calorimetry measurement) in accordance with JIS K7121 .

6. The hydroxyl value of the plasticizer

The hydroxyl value of the plasticizer was measured in accordance with the JIS K1557.

7. Sound insulation properties (loss factor and flexural rigidity of laminated glass at the secondary resonance frequency)

Laminated glass was produced by sandwiching each interlayer film derived in the Embodiments and Comparative Embodiments, cut to the dimensions of length: 300 mm width: 25 mm between two commercially available float glasses (length: 300 mm width: 25 mm thickness: 1 .9 mm). After performing temporary bonding at the conditions of reduced pressure of 130 Pa at 100°C for 20 minutes using a vacuum lamination device, the laminated glass was manufactured by performing pressure bonding at the conditions of a temperature of 140°C, pressure of 1 .0 MPa for 60 minutes using an autoclave.

After one week had elapsed since the manufacture of the laminated glass, the central part of the lower surface of the manufactured laminated glass was fixed to the tip of an excitation force detector built into an impedance head of a vibration exciter (power amplifier/model 371 -A) in a mechanical impedance instrument (manufactured by ONO SOKKI CO., LTD; mass cancel amplifier: mass cancel amplifier MA- 5500; channel data station: DS-2100). A damping test of the laminated glass by the center excitation method was performed by applying vibration to the central part of the laminated glass in a frequency range of 0 to 10,000 Hz at 20°C and detecting the excitation force and acceleration waveform at this excitation point (the central part of the laminated glass to which vibration was applied) (In accordance with ISO 16940-2008). The mechanical impedance of the excitation point was derived based on the derived excitation force and the speed signal derived by integrating the acceleration signal, and a loss factor of the laminated glass was derived from the frequency and the half-width showing the peak in the impedance curve with the frequency on the horizontal axis and the mechanical impedance on the vertical axis.

8. The followability of the curvature of the transparent substrate

The outermost layer of laminated glass wherein two sheets of clock faces (diameter 15 cm) of commercially available Pyrex was used. Interlayer films (a size was cut so as to protrude 1 cm from the edge part of the clock faces) manufactured in the embodiments and comparative embodiments were sandwiched between the clock faces (between the lower surface of the first clock face and the upper surface of the second clock face), and was fixed using polyimide tape at four points on the outer periphery at equal spacing. This was inserted into an aluminum bag, and as the temporary pressure adhesion process, was heated up to a temperature of 100°C over approximately 15 minutes under reduced pressure (-0.095 to 0.098 MPa) and after holding at 100°C for 30 minutes, was cooled to room temperature over approximately 30 minutes, and extracted from the aluminum bag. Thereafter, as the autoclave process, it was processed at 1 .2 MPa at 135°C for 30 minutes, to derive the laminated glass. For the evaluation of the following ability of the curvature, it was assessed according to the following standards.

A: The interlayer film followed the glass, and no defects were apparent in the outer appearance.

B: There is not complete adhesion of the interlayer film to the glass, and gaps have been generated between the interlayer film and the glass.

Embodiment 1

As the resin material constituting layer A, a linear hydrogenated styrene-isoprene-styrene triblock copolymer (hydrogenation rate: 93%, weight average molecular weight 258,000, Glass transition temperature of polymer block (a) of 100°C, and a glass transition temperature of polymer block (b) of - 19°C) containing 8 wt% of a styrene unit and 92 wt% of an isoprene unit, and having a tan d peak temperature of -11 .8°C and a tan d peak height of 2.5 was used.

As a resin material constituting each B layer, a resin composition consisting of a polyvinyl butyral resin (an acetalization degree: 70 mol%, vinyl acetate unit content 0.9 mol%, a viscosity-average degree of polymerization of polyvinyl alcohol as a raw material: about 1 ,700) and a plasticizer [polyester polyol manufactured by KURARAY CO., LTD. "Kuraray Polyol P-510" (fusion point: -77°C, hydroxyl value: 213.0 to 235.0 mg KOH/g)] (the amount of the plasticizer relative to 100 parts weight of the polyvinyl butyral resin was 38.8 parts weight) was used.

Each of these resin materials was extruded to produce layer A having a thickness of 250 pm and layer B having a thickness of 250 pm and a layer C having a thickness of 1250 pm. Two sheets of the so derived layer A, two sheets of layer B and layer C were laminated in an order so as to form layer B/layer A/layer C/layer A/layer B, and press molded at 150°C to manufacture an interlayer film with the thickness of 2250 pm which was a composite film of a five layer configuration. Now, in relation to the resin materials configuring layer A, the tensile storage elasticity modulus when measured at 20°C in the conduct of the dynamic viscoelastic test at the conditions of a frequency of 0.3 Hz in accordance with JIS K7244-4:1999 was less than 20 MPa.

Interlayer film, the soundproofing and follow ability of a curved glass surface were evaluated. Those results are represented in Table 1 .

Embodiments 2 -4

Interlayer films were manufactured which were prepared in an identical manner to embodiment 1 , other than having configurations as recited in table 1 , now, as the resin material configuring layer a, and identical resin to the resin employed in embodiment 1 was employed. In respect of the resin materials configuring layers B and C, the same PVB resin and plasticizer as used in embodiment 1 were employed, but the content of the plasticizer was modified as recited in the table. Evaluations of the soundproofing and followability of a curved glass surface were performed on the derived interlayer films. Those results are represented in table 1 .

Comparative Embodiments 1 -6

Interlayer films were manufactured which were prepared in an identical manner to embodiment 1 , other than having configurations as recited in Table 2. Evaluations of the soundproofing and followability of a curved glass surface were performed on the derived interlayer films. Those results are represented in Table 2. Table 1

Table 2

On comparing the soundproofing and curved surface follow ability in tables 1 and 2, the laminated glass of embodiments 1 - 4 had high loss factors equal to or greater than 0.58, in addition to, also having superior follow ability of glass curved surfaces, while the laminated glass of comparative embodiments 1 - 6 had low loss factors, or alternatively, can be appreciated to have inferior follow ability of glass curved surfaces. These results illustrate how the interlayer film for use in laminated glass of the present invention provides both high soundproofing and good follow ability of curved glass surfaces, and laminated glass employing these types of interlayer films for use in laminated glass provide high soundproofing.

INDUSTRIAL APPLICABILITY

The interlayer film for use in laminated glass and the laminated glass of the present invention are particularly suitably used for a glass for a vehicle that requires high sound insulation (for example, window glass for a vehicle, window glass for construction).

DESCRIPTION OF REFERENCE NUMERALS

1a: Layer A 1b: Layer A 2a: Layer B 2b: Layer B 3: Layer C

Claims

Claim 1

An interlayer film for use in laminated glass comprising layer B, layer A, layer C, layer A, layer B in that order, wherein layer A comprises a first thermoplastic resin layer, and the resin material configuring layer A has a peak at which the tan d, measured by performing a complex shear viscosity test under the conditions of a frequency of 1 Hz according to JIS K 7244-10: 2005, is maximum in a range of -30°C or more and 10°C or less, and the height of the peak of tan d is 1 .5 or more, and layer B is a layer comprising a second thermoplastic resin, configured from a different resin material to the resin material configuring layer A, and the resin material configuring layer B has a tensile storage elasticity modulus equal to or greater than 20 MPa and less than or equal to 1 .2 GPa when measured at 20°C in the conduct of a dynamic viscoelastic test at a frequency of 0.3 Hz in accordance with JIS K 7244-4:1999, and the thickness of layer B is equal to or greater than 100 pm and less than or equal to 2.0 mm, and layer C is a layer comprising a third thermoplastic resin, which is a different resin material to that configuring layer A, and may be configured from a resin material which is the same or different than the resin material configuring layer B, and the resin material configuring layer C has a tensile storage elasticity modulus equal to or greater than 20 MPa and less than or equal to 1 .2 GPa when measured at 20°C in the conduct of a dynamic viscoelastic test at a frequency of 0.3 Hz in accordance with JIS K 7244-4:1999, and the thickness of layer C is equal to or greater than 100 pm and less than or equal to 2.0 mm, and the thickness of either one of layer B and layer C is equal to or greater than 900 pm and less than or equal to 2.0 mm.

Claim 2

The interlayer film for use in laminated glass according to claim 1 , wherein layer A comprises a hydrogenated product of a block copolymer having a block polymer (a) containing 60 mol% or more of an aromatic vinyl monomer unit and a block polymer (b) containing 60 mol% or more of a conjugated diene monomer unit as the first thermoplastic resin, and the hydrogenated product of the block copolymer has a content of the block polymer (a) of 25 wt% or less based on the total mass of the hydrogenated product of the block copolymer. Claim 3

The interlayer film for use in laminated glass according to claim 1 or 2, wherein at least one of the layers B comprises a polyvinyl acetal resin or an ionomer resin as the second thermoplastic resin.

Claim 4

The interlayer film for use in laminated glass according to claim 3, wherein layer B comprises the polyvinyl acetal resin and the content of plasticizer is 50 parts weight or less relative to 100 parts weight of the polyvinyl acetal resin.

Claim 5

The interlayer film for use in laminated glass according to claim 4, wherein the plasticizer is an ester- based plasticizer or an ether-based plasticizer having a fusion point of 30°C or less and a hydroxyl group value of 15 to 450 mg KOH/g.

Claim 6

The interlayer film for use in laminated glass according to any one of claims 1 to 5, wherein the third thermoplastic resin of layer C comprises any one of an acrylic resin, an ionomer resin or a polyvinyl acetal resin.

Claim 7

The interlayer film for use in laminated glass according to claim 6 wherein the C layer comprises the polyvinyl acetal resin and the content of plasticizer is equal to or greater than 15 parts weight and less than or equal to 55 parts weight in relation to 100 parts weight of the polyvinyl acetal resin.

Claim 8

The interlayer film for use in laminated glass according to claim 7, wherein the plasticizer contained in layer C is an ester-based plasticizer or an ether-based plasticizer having a fusion point of 30°C or less and a hydroxyl group value of 15 to 450 mg KOH/g.

Claim 9

The interlayer film for use in laminated glass according to any one of claims 1 to 8, wherein the total thickness of layer B and layer C is 2.5 mm or less.

Claim 10

The interlayer film for use in laminated glass according to any one of claims 1 to 9 wherein the laminated glass derived by sandwiching the interlayer film for use in laminated glass employs two sheets of float glass having a length of 300 mm, a width of 25 mm, and a thickness of 1 .9 mm and the loss factor at a secondary resonance frequency measured by the center excitation method at 20°C is 0.58 or more.

Claim 11

The laminated glass sandwiching an interlayer film for use in laminated glass according to any one of claims 1 to 10 between two sheets of translucent substrate, wherein at least one sheet of the translucent substrates is inorganic glass having a thickness of 1 . 2 to 3.0 mm.

Claim 12

The interlayer film for use in laminated glass according to claim 11 , which is a windshield for a vehicle, a side window for a vehicle, a sunroof for a vehicle, a rear window for a vehicle, or a glass for a heads-up display.

Claim 13

The laminated glass sandwiching an interlayer film for use in laminated glass according to any one of claims 1 to 10 between two sheets of translucent substrate, wherein at least one sheet of the translucent substrates is inorganic glass having a thickness of 3.0 to 10.0 mm.

Claim 14

Laminated glass according to [13] above which is glass for use in architecture.