CN113454041B

CN113454041B - Interlayer for laminated glass and laminated glass

Info

Publication number: CN113454041B
Application number: CN202080015393.7A
Authority: CN
Inventors: 有岛裕之
Original assignee: Kuraray Europe GmbH
Current assignee: Kuraray Europe GmbH
Priority date: 2019-02-25
Filing date: 2020-02-14
Publication date: 2023-06-20
Anticipated expiration: 2040-02-14
Also published as: CN113454041A; JPWO2020175178A1; WO2020175178A1; DE112020000944T5

Abstract

The present disclosure relates to an interlayer film for laminated glass, comprising at least an a layer made of a thermoplastic resin material and a B layer made of a polyvinyl acetal resin composition, wherein the thermoplastic resin material contains, as a thermoplastic resin, a hydrogenated product of a block copolymer having: a polyvinyl acetal resin composition comprising a polyvinyl acetal resin and a plasticizer having an aromatic ring in a molecular structure, the content of the polymer block (a) in a hydrogenated product of the block copolymer being 25 mass% or less relative to the total mass of the hydrogenated product of the block copolymer, the content of the plasticizer being 0.5 to 100 parts by mass relative to 100 parts by mass of the polyvinyl acetal resin, the SP value of the plasticizer being 10.0 (cal/cm ³ ) ^1/2 The above.

Description

Interlayer for laminated glass and laminated glass

Technical Field

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

Background

It is known that a glass plate used for a window glass or the like is excellent in durability and lighting property, but has very small damping performance (tan δ to bending vibration). Therefore, the vibration of the glass coincides with the vibration of the incident sound wave, and a resonance state is caused, and a phenomenon (superposition effect, coincidence effect) in which the transmission loss is significantly reduced is observed.

On the other hand, in recent years, efforts have been known to improve fuel efficiency by making a laminated glass lightweight and making an automobile lightweight. In general, the weight reduction can be achieved by reducing the thickness of the laminated glass, but the sound insulation property is reduced with the reduction in weight thereof, and therefore, in order to achieve the weight reduction, a means for compensating for the reduction in sound insulation property is required.

As a method for improving the sound insulation, there is a method of using an interlayer film for laminated glass (hereinafter, also simply referred to as "interlayer film") having excellent damping performance. The intermediate film has the ability to convert vibrational energy into thermal energy to reduce vibrational energy. As such an intermediate film, for example, patent document 1 proposes: an intermediate film for laminated glass, wherein a resin film A formed of a copolymer of polystyrene and a rubber-based resin (hereinafter referred to as "styrene-based thermoplastic elastomer") is sandwiched between resin films B formed of plasticized polyvinyl acetal-based resin.

Here, when a resin film (laminated resin film) laminated adjacent to a resin film (plasticized polyvinyl acetal resin-containing resin film) containing a polyvinyl acetal resin and a plasticizer is composed of a styrene-based thermoplastic elastomer as in the above example, a plasticizer (for example, a carboxylic acid ester compound of a polyhydric carboxylic acid and a monohydric alcohol such as dihexyl adipate or dioctyl phthalate, or a carboxylic acid ester compound of a polyhydric alcohol and a monohydric carboxylic acid such as triethylene glycol di-2-ethylhexanoate (3G 8) or triethylene glycol di-heptanoate) commonly used in interlayer film applications for laminated glass is used as the plasticizer, it is known that the plasticizer migrates from the plasticized polyvinyl acetal resin-containing resin film to the laminated resin film, resulting in a problem such as an increase in haze. Accordingly, as a plasticizer which is less likely to cause the migration, an ester plasticizer or an ether plasticizer having a hydroxyl value of 15 to 450mgKOH/g has been proposed (for example, patent document 2).

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2007-91491

Patent document 2: international publication 2011/016495 booklet

Disclosure of Invention

Problems to be solved by the invention

However, the present inventors have found that, when a layer comprising a resin composition of an ester-based plasticizer or an ether-based plasticizer having a hydroxyl value of 15 to 450mgKOH/G is formed in the production of a laminated glass in which the layer is in contact with glass, the composition has a higher hygroscopicity than when 3G8 is used as a plasticizer, and as a result, the following problems are found: it is difficult to secure sufficient adhesion between the layer and the glass depending on the atmosphere conditions, or the adhesion between the layer and the glass is lowered due to moisture absorption from the end of the intermediate film or laminated glass produced by the user. In addition, in general, the adhesiveness between the polyvinyl acetal resin layer and glass can be controlled by the amount of the adhesion regulator such as magnesium acetate, but the following problems have been found: in the polyvinyl acetal resin layer having high hygroscopicity or containing a large amount of moisture, the influence of the decrease in the adhesive force due to moisture is large, and it is difficult to control the layer with the adhesive force regulator.

Accordingly, an object of the present invention is to provide an intermediate film which can solve the above-mentioned problems, that is, an intermediate film which is sufficiently high in transparency and sound insulation and can achieve excellent adhesion to glass and control of adhesion to glass.

Solution for solving the problem

The present inventors have conducted intensive studies on an interlayer film for laminated glass to solve the above problems, and as a result, have completed the present invention. That is, the present invention includes the following suitable modes.

[1] An intermediate film for laminated glass comprising at least one layer A made of a thermoplastic resin material and at least one layer B made of a polyvinyl acetal resin composition,

the thermoplastic resin material contains, as a thermoplastic resin, a hydrogenated product of a block copolymer having: a polymer block (a) containing 60 mol% or more of an aromatic vinyl monomer unit and a polymer block (b) containing 60 mol% or more of a conjugated diene monomer unit, the content of the polymer block (a) in the hydrogenated product of the block copolymer being 25 mass% or less relative to the total mass of the hydrogenated product of the block copolymer,

the polyvinyl acetal resin composition comprises a polyvinyl acetal resin and a plasticizer having an aromatic ring in a molecular structure, wherein the content of the plasticizer is 0.5 to 100 parts by mass relative to 100 parts by mass of the polyvinyl acetal resin, and the SP value of the plasticizer is 10.0 (cal/cm ³ ) ^1/2 The above.

[2] The interlayer film for laminated glass according to the above [1], wherein the plasticizer does not have a hydroxyl group in the molecular structure.

[3]According to the above [1]]Or [2]]The interlayer film for laminated glass, wherein the plasticizer has a refractive index n _D Is 1.50 or more.

[4] The interlayer film for laminated glass according to any of the above [1] to [3], wherein the water content of the sheet-like polyvinyl acetal resin composition having a thickness of 500 μm when subjected to humidity control at 20℃for 48 hours at a relative humidity of 65% is 1.80 mass% or less.

[5] The interlayer film for laminated glass according to any of the above [1] to [4], wherein the polyvinyl acetal resin composition contains 1 or more plasticizers selected from the group consisting of benzoate esters, aromatic phosphate esters and phthalate esters as the plasticizer.

[6] The interlayer film for laminated glass according to any of the above [1] to [5], wherein the polyvinyl acetal resin composition further contains 1 or more magnesium salts selected from the group consisting of magnesium salts of carboxylic acids having 2 to 12 carbon atoms.

[7] The interlayer film for laminated glass according to any of the above [1] to [6], wherein the thermoplastic resin material has a composition according to JIS K7244-10 in a range of-30℃to 10 ℃. 2005, the peak having a maximum tan delta measured by a complex shear viscosity test at a frequency of 1Hz, the tan delta peak having a height of 1.5 or more.

[8] The interlayer film for laminated glass according to any of [1] to [7], which comprises the layer A having a thickness of 100 μm or more and 400 μm or less and the layer B having a thickness of 200 μm or more and 1500 μm or less, which is laminated on both sides of the layer A.

[9] The interlayer film for laminated glass according to any of [1] to [7], which comprises the layer A and the layer B in the order of layer B/layer A/layer B.

[10] A laminated glass comprising the interlayer film for laminated glass of any one of [1] to [9] sandwiched between 2 sheets of glass, wherein the laminated glass 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.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, an intermediate film having sufficiently high transparency and sound insulation properties and capable of achieving excellent adhesion to glass and control of adhesion to glass can be provided.

Drawings

Fig. 1 is a schematic cross-sectional view showing a configuration of an intermediate film for laminated glass according to the present disclosure.

FIG. 2 is a schematic cross-sectional view showing a configuration of an intermediate film for laminated glass according to the present disclosure

Detailed Description

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

The interlayer film for laminated glass of the present disclosure comprises at least one layer a composed of a thermoplastic resin material and at least one layer B composed of a polyvinyl acetal resin composition.

[ layer B ]

First, layer B will be described. The polyvinyl acetal resin composition constituting the layer B contains a polyvinyl acetal resin and a plasticizer having an aromatic ring in a molecular structure, wherein the content of the plasticizer is 0.5 to 100 parts by mass relative to 100 parts by mass of the polyvinyl acetal resin, and the SP value (solubility parameter ) of the plasticizer is 10.0 (cal/cm ³ ) ^1/2 The above. That is, the plasticizer has a specific SP value and has an aromatic ring in a molecular structure.

Plasticizer >

A plasticizer having a specific SP value and an aromatic ring in a molecular structure will be described. The plasticizer contained in the polyvinyl acetal resin composition constituting the B layer has an aromatic ring in a molecular structure. The aromatic ring is present in a molecular structure at a high density of a certain degree or more, so that the SP value of the plasticizer becomes 10.0 (cal/cm ³ ) ^1/2 As described above, migration of the plasticizer to an adjacent layer, for example, a layer (layer made of a thermoplastic resin material containing a hydrogenated product of an aromatic vinyl-conjugated diene block copolymer (for example, a styrene thermoplastic elastomer) as a thermoplastic resin) described later can be suppressed. When the plasticizer contains a large amount of functional groups other than aromatic rings, the SP value becomes low, and as a result, migration of the plasticizer to an adjacent layer, for example, the a layer, is likely to occur, and haze in the a layer or a decrease in the sound insulation property of the laminated glass is likely to occur. The SP value of the plasticizer in the present disclosure is preferably 10.2 (cal/cm ³ ) ^1/2 Above, more preferably 10.3 (cal/cm) ³ ) ^1/2 Above, more preferably 10.4 (cal/cm) ³ ) ^1/2 Above, particularly preferably 10.5 (cal/cm ³ ) ^1/2 The above. Here, the SP value refers to a value calculated according to the calculation method of Fedors (R.F.Fedors, polym.Eng.Sci.,14,147 (1974)).

Plasticizers having a specific SP value and an aromatic ring in the molecular structure preferably have no hydroxyl group in the molecular structure. The plasticizer containing hydroxyl groups is preferable from the viewpoint of easily suppressing migration of the plasticizer from a layer composed of a resin composition containing the plasticizer to an adjacent layer (for example, a layer a). However, since the moisture absorption of the plasticizer itself is high, the moisture absorption of the resin composition containing the plasticizer is also high, and therefore, in the case of a laminated glass using an interlayer film including a layer made of such a resin composition, in the case of a constitution in which the layer is in contact with glass, there is a possibility that problems may occur in adhesiveness with glass and adhesion control.

The hydroxyl value of the plasticizer having a specific SP value and having an aromatic ring in its molecular structure is preferably 10.0mgKOH/g or less, and also preferably 9.0mgKOH/g or less, 7.0mgKOH/g or less, or 5.0mgKOH/g or less. The hydroxyl value of the plasticizer can be measured in accordance with JIS K1557.

The plasticizer may have a refractive index n of about 1.5 or more by the presence of aromatic rings in the molecular structure at a high density of a certain or more _D . The refractive index of a layer comprising a polyvinyl acetal resin composition containing such a plasticizer is equal to that of a layer comprising 3G8 (n) _D About 1.45), and the like, is close to the refractive index of the a layer as compared with the refractive index of the layer composed of the polyvinyl acetal resin composition of the plasticizer. However, when the embossed shape is transferred to the inner layer by shaping the surface layer of the multilayer intermediate film, scattering of light due to a difference between the refractive index of the surface layer and the refractive index of the inner layer is suppressed as the refractive index difference is smaller. Therefore, from the viewpoint of easily suppressing such light scattering, the refractive index n of the plasticizer _D Preferably 1.50 or more, more preferably 1.51 or more, and particularly preferably 1.52 or more. The refractive index of the plasticizer can be measured, for example, by an Abbe refractometer.

In a preferred embodiment, the polyvinyl acetal resin composition contains 1 or more plasticizers selected from the group consisting of benzoate esters, aromatic phosphate esters, and phthalate esters as the plasticizer.

The benzoate is not particularly limited as long as it has a specific SP value, and a known benzoate can be used as the plasticizer. When the bonding group to benzoic acid is an alkylene glycol group, the repeating unit of the glycol chain is preferably 10 or less from the viewpoint of easy obtaining of low hygroscopicity. Specific examples of such benzoate esters include alkylene glycol dibenzoates such as diethylene glycol dibenzoate (DEGDB) and dipropylene glycol dibenzoate (DPGDB). As the benzoate, commercially available products can be suitably used, and examples thereof include "MonoCIZER PB-3A" and "MonoCIZER PB-10" manufactured by DIC Co., ltd., and "ADEKACIZER PN-6120" manufactured by ADEKA, co., ltd.

The aromatic phosphoric acid ester is not particularly limited as long as it has a specific SP value, and a known aromatic phosphoric acid ester can be used as the plasticizer. Specific examples thereof include triphenyl phosphate (TPP), tricresyl phosphate (TCP), and tris (xylene) phosphate (TXP).

The phthalate is not particularly limited as long as it has a specific SP value, and known phthalate can be used as a plasticizer. Specific examples thereof include diphenyl phthalate and Benzyl Butyl Phthalate (BBP).

The polyvinyl acetal resin composition of the present disclosure mainly contains, as a plasticizer, a plasticizer having a specific SP value and having an aromatic ring in a molecular structure. Such a plasticizer may be contained only 1 kind alone, or in combination of 2 or more kinds. In addition, the polyvinyl acetal resin composition of the present disclosure may further contain 1 or more plasticizers other than such plasticizers.

The plasticizer having a specific SP value and having an aromatic ring in a molecular structure is contained in an amount of 0.5 to 100 parts by mass relative to 100 parts by mass of the polyvinyl acetal resin. If the content of the plasticizer is more than 100 parts by mass, it is difficult for the laminated glass using the obtained interlayer film to have sufficient impact resistance. The content of the plasticizer is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, further preferably 43 parts by mass or less, particularly preferably 40 parts by mass or less, from the viewpoint of easy obtaining of good impact resistance of the laminated glass using the obtained interlayer. The content of the plasticizer is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more, based on 100 parts by mass of the polyvinyl acetal resin. The content of the plasticizer is also preferably 15 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more per 100 parts by mass of the polyvinyl acetal resin.

From the viewpoint of easy obtaining of low or non-migration properties of the plasticizer from the B layer to the adjacent layer (for example, a layer) and low hygroscopicity of the polyvinyl acetal resin composition constituting the B layer, the ratio of the plasticizer having a specific SP value and having an aromatic ring in the molecular structure is preferably 50 mass% or more, more preferably 70 mass% or more, still more preferably 80 mass% or more, particularly preferably 90 mass% or more, and most preferably 100 mass% with respect to the total mass of the plasticizer.

< polyvinyl acetal resin >)

The polyvinyl acetal resin composition of the present disclosure contains a polyvinyl acetal resin in addition to a plasticizer.

The acetalization degree of the polyvinyl acetal resin used in the present disclosure is preferably 40 mol% or more, more preferably 60 mol% or more, preferably 90 mol% or less, more preferably 85 mol% or less, and still more preferably 80 mol% or less. The acetalization degree is as follows; the unit formed of 2 carbons of the main chain in the polyvinyl alcohol resin (for example, a vinyl alcohol unit, a vinyl acetate unit, an ethylene unit, etc.) as a single repeating unit, and the amount of the unit forming an acetal based on the single repeating unit. When the acetalization degree is within the range of the lower limit and the upper limit, the compatibility between the polyvinyl acetal resin and the plasticizer is easy to be good, and a polyvinyl acetal resin composition containing the polyvinyl acetal resin and the plasticizer is easy to be obtained, and therefore, it is preferable from the viewpoint of the process. In addition, from the viewpoint of water resistance, the acetalization degree of the polyvinyl acetal resin is preferably 65 mol% or more. The acetalization degree can be adjusted by adjusting the amount of aldehyde used in the acetalization reaction.

The content of the vinyl acetate unit in the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less. The content of vinyl acetate units is as follows: the amount of vinyl acetate units based on one repeating unit is defined by a unit (for example, a vinyl alcohol unit, a vinyl acetate unit, a vinyl unit, etc.) formed of 2 carbons of the main chain in the polyvinyl alcohol resin as a raw material for producing the polyvinyl acetal resin. If the content of the vinyl acetate unit is not more than the above upper limit, blocking is less likely to occur in 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 vinyl acetate units is usually 0.3 mol% or more. The content of the vinyl acetate unit can be adjusted by appropriately adjusting the saponification degree of the polyvinyl alcohol resin of the raw material.

The content of the vinyl alcohol unit in the polyvinyl acetal resin is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more, preferably 35 mol% or less, more preferably 30 mol% or less, still more preferably 25 mol% or less, and particularly preferably 20 mol% or less. The content of vinyl alcohol units is as follows: the amount of a vinyl alcohol unit based on one repeating unit is defined as a unit (for example, a vinyl alcohol unit, a vinyl acetate unit, and an ethylene unit) formed of 2 carbons of the main chain in a polyvinyl alcohol resin as a raw material for producing a polyvinyl acetal resin. If the content of the vinyl alcohol unit is not less than the above lower limit, the adhesion to glass can be easily and favorably controlled. If the content of the vinyl alcohol unit is not more than the above-mentioned upper limit, the penetration resistance and impact resistance required for the interlayer film as a safety glass can be suitably controlled. The content of the vinyl alcohol unit can be adjusted by adjusting the amount of aldehyde used in the acetalization reaction.

The polyvinyl acetal resin is generally composed of acetal-forming units, vinyl alcohol units and vinyl acetate units, and the amounts of these units can be measured by, for example, JIS K6728 "polyvinyl butyral test method" or Nuclear Magnetic Resonance (NMR).

The polyvinyl acetal resin may be used alone or in combination of 2 or more kinds different in acetalization degree, viscosity average polymerization degree, and the like.

The polyvinyl acetal resin can be produced by a conventionally known method, and typically can be produced by acetalizing a polyvinyl alcohol resin (for example, a polyvinyl alcohol resin or an ethylene vinyl alcohol copolymer) with an aldehyde. Specifically, for example, a polyvinyl alcohol resin is dissolved in hot water, the aqueous solution thus obtained is kept at a predetermined temperature (for example, 0 ℃ or higher, preferably 10 ℃ or higher, for example, 90 ℃ or lower, preferably 20 ℃ or lower), and the desired acid catalyst and aldehyde are added thereto, followed by carrying out an acetalization reaction with stirring. Then, the reaction temperature was raised to about 70℃to age, and after the completion of the reaction, the powder of the polyvinyl acetal resin was obtained by neutralization, washing with water and drying.

The viscosity average polymerization degree of the polyvinyl alcohol resin as the raw material of the polyvinyl acetal resin is preferably 100 or more, more preferably 300 or more, still more preferably 400 or more, still more preferably 600 or more, particularly preferably 700 or more, and most preferably 750 or more. If the viscosity average polymerization degree of the polyvinyl alcohol resin is too low, the penetration resistance and creep resistance, in particular, the creep resistance under high temperature and high humidity conditions such as 85 ℃ and 85% rh may be lowered. The viscosity average polymerization degree of the polyvinyl alcohol resin is preferably 5000 or less, more preferably 3000 or less, further preferably 2500 or less, particularly preferably 2300 or less, and most preferably 2000 or less. If the viscosity average polymerization degree of the polyvinyl alcohol resin is too high, the layer formed from the polyvinyl acetal resin composition may be difficult to form.

Further, in order to improve the lamination (stacking) suitability of the intermediate film for laminated glass obtained and to obtain laminated glass having further excellent appearance, in one embodiment of the present disclosure, the viscosity average polymerization degree of the polyvinyl alcohol resin is preferably 1800 or less, more preferably 1600 or less, further preferably 1300 or less, further preferably 1100 or less, and particularly preferably 1000 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 resin.

In order to set the vinyl acetate unit of the obtained polyvinyl acetal resin to 30 mol% or less, a polyvinyl alcohol resin having a saponification degree of 70 mol% or more is preferably used. If the saponification degree of the polyvinyl alcohol resin is not less than the above lower limit, the resin tends to be excellent in transparency and heat resistance, and reactivity with aldehyde is also good. The saponification degree is more preferably 95 mol% or more.

The viscosity average polymerization degree and saponification degree of the polyvinyl alcohol resin can be measured, for example, based on JIS K6726 "polyvinyl alcohol test method".

The aldehyde used for acetalization of a polyvinyl alcohol resin is preferably an aldehyde having 1 to 12 carbon atoms. When the carbon number of the aldehyde is within the above range, the acetalization reaction is excellent, and the resin is less likely to be blocked during the reaction, so that the synthesis of the polyvinyl acetal resin can be easily performed.

The aldehyde is not particularly limited, and examples thereof include aliphatic, aromatic or alicyclic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, valeraldehyde, n-caproaldehyde, 2-ethylbutyraldehyde, n-heptanal, n-caprylic aldehyde, n-pelargonic aldehyde, n-capric aldehyde, benzaldehyde and cinnamaldehyde. Among these, aliphatic aldehydes having 2 to 6 carbon atoms are preferable, and n-butyraldehyde is particularly preferable. The aldehyde may be used alone or in combination of at least 2 types. Further, a polyfunctional aldehyde, an aldehyde having another functional group, or the like may be used in a small amount in a range of 20 mass% or less of the total aldehyde.

As the polyvinyl acetal resin, a polyvinyl butyral resin is most preferable. As the polyvinyl butyral resin, a polyvinyl butyral resin obtained as follows can be used: a polyvinyl butyral resin obtained by butyrally polymerizing a polyvinyl alcohol polymer obtained by saponifying a copolymer of a vinyl ester and another monomer with butyraldehyde. Examples of the other monomer include ethylene, propylene, and styrene. As the other monomer, a monomer having a hydroxyl group, a carboxyl group, or a carboxylate group can be used.

The polyvinyl acetal resin composition of the present disclosure may further contain a resin other than the polyvinyl acetal resin as a resin component. The content of the polyvinyl acetal resin in the polyvinyl acetal resin composition is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, particularly preferably 80% by mass or more, and most preferably 90% by mass or more, from the viewpoint of maintaining high adhesion to glass easily. The content of the polyvinyl acetal resin in the polyvinyl acetal resin composition is also preferably 95 mass% or more, 98 mass% or more, 99 mass% or more, 99.9 mass% or more, or 99.99 mass% or more.

< adhesive force regulator >)

The polyvinyl acetal resin composition of the present disclosure may contain, for example, an adhesive force modifier disclosed in international publication No. 03/033583 in addition to the aforementioned plasticizer and polyvinyl acetal resin. When the polyvinyl acetal resin composition contains the adhesion regulator, the polyvinyl acetal resin composition preferably contains 1 or more magnesium salts selected from the group consisting of magnesium salts of carboxylic acids having 2 to 12 carbon atoms. The magnesium salt preferably functions as an adhesion regulator for adjusting adhesion to glass. As the adhesion regulator, magnesium acetate which is generally used is also suitably used, but magnesium salts of carboxylic acids having 6 to 12 carbon atoms are preferably used from the viewpoint of easily suppressing the formation of a white layer on the wall in the film forming apparatus (for example, on the wall in the extruder, on the inner wall of the extrusion die and/or on the inner wall of the die lip). As the carboxylic acid having 6 to 12 carbon atoms, examples include caproic acid, 2-ethylbutyric acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid, undecanoic acid, dodecanoic acid, 2-ethylhexanoic acid, 2-ethylbutyric acid, 2-propylheptanoic acid, 2, 2-dimethylbutyric acid, 2-dimethylvaleric acid, 2-dimethylhexanoic acid, 2-dimethylheptanoic acid, and 2, 2-dimethyloctanoic acid, 2-dimethylnonanoic acid, 2-dimethyldecanoic acid, neodecanoic acid, and the like. Among them, carboxylic acids having 9 to 12 carbon atoms are preferable, and neodecanoic acid is more preferable.

When the magnesium salt of a carboxylic acid is added, the optimum amount to be added varies depending on the plasticizer to be used, the type of the adhesive force modifier to be added, or the type of the resin layer to be laminated. The content of magnesium ions derived from the magnesium salt of a carboxylic acid is preferably 1 to 420ppm, more preferably 2 to 300ppm, still more preferably 3 to 100ppm, relative to the total mass of the polyvinyl acetal resin composition. By properly adjusting the amount of the additive within this range, the glass scattering prevention property can be adjusted to meet the application.

As the adhesion regulator, in addition to or instead of the magnesium salt, 1 or more of additives such as modified silicone oil and organic acids may be used. Examples of the modified silicone oil include epoxy modified silicone oil, ether modified silicone oil, ester modified silicone oil, amine modified silicone oil, carboxyl modified silicone oil and the like shown in Japanese patent publication No. 55-29950. Examples of the organic acid include at least 1 organic acid having 4 to 30 carbon atoms as shown in Japanese patent application laid-open No. 2017-71760.

The polyvinyl acetal resin composition of the present disclosure may further contain an antioxidant, an ultraviolet absorber, a light stabilizer, an antiblocking agent, a pigment, a dye, a functional inorganic compound, a heat insulating material, or the like as other components as necessary.

Examples of the antioxidant include phenol antioxidants, phosphorus antioxidants, and sulfur antioxidants.

The amount of the antioxidant to be added is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, preferably 5 parts by mass or less, and still more preferably 1 part by mass or less, based on 100 parts by mass of the polyvinyl acetal resin. If the amount of the antioxidant is not less than the lower limit and not more than the upper limit, a sufficient antioxidant effect can be imparted.

Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, hindered amine-based ultraviolet absorbers, benzoate-based ultraviolet absorbers, triazine-based compounds, benzophenone-based compounds, malonate-based compounds, indole-based compounds, oxanilide-based compounds, and the like. The ultraviolet absorber may be used alone or in combination of 2 or more.

The amount of the ultraviolet absorber to be added is preferably 10ppm or more, more preferably 100ppm or more, preferably 50000ppm or less, more preferably 10000ppm or less, based on mass of the polyvinyl acetal resin. If the amount of the ultraviolet absorber is within the range of the lower limit and the upper limit, a sufficient ultraviolet absorbing effect can be expected.

Examples of the light stabilizer include hindered amine light stabilizers.

By including the heat insulating material, a heat insulating function can be imparted to the interlayer film for laminated glass, and the transmittance of near infrared light having a wavelength of about 1500nm can be reduced when forming laminated glass.

When the heat insulating material is contained, the heat insulating material is preferably at least 1 selected from the group consisting of tin-doped indium oxide, antimony-doped tin oxide, zinc antimonate, metal-doped tungsten oxide, diimmonium (diimmonium) based pigment, amine based pigment, phthalocyanine based pigment, anthraquinone based pigment, polymethine based pigment, dithiol type ammonium compound, thiourea derivative, thiol metal complex, aluminum-doped zinc oxide, tin-doped zinc oxide, silicon-doped zinc oxide, lanthanum hexaboride and vanadium oxide.

When the heat ray shielding particles are used as the heat insulating material, the content thereof is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, preferably 5% by mass or less, and more preferably 3% by mass or less. The heat insulating material of the present disclosure may be any one of the layers a and B contained in an interlayer film for laminated glass described later, and the "content" refers to an amount obtained when the total mass of the resin materials or resin compositions constituting the layers a and B is 100% by mass. The "content" of the organic pigment compound described later has the same meaning. If the content of the heat ray shielding particles is within the range of the lower limit value and the upper limit value, the transmittance of visible light of the laminated glass using the obtained interlayer film is not affected, and the transmittance of near-infrared light having a wavelength of about 1500nm is easily and effectively reduced. The average particle diameter of the heat ray-shielding particles is preferably 100nm or less, more preferably 50nm or less, from the viewpoint of transparency of the intermediate film. The average particle diameter is an average particle diameter measured by a laser diffraction device.

When the organic pigment compound is used as the heat insulating material, the content thereof is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, still more preferably 0.01% by mass or more, preferably 1% by mass or less, and still more preferably 0.5% by mass or less. If the content of the organic pigment compound is within the range of the lower limit and the upper limit, the transmittance of visible light of the laminated glass using the obtained interlayer film is not affected, and the transmittance of near-infrared light having a wavelength of about 1500nm is easily and effectively reduced.

In the interlayer film for laminated glass of the present disclosure, the thickness of the B layer 1 layer is preferably 100 μm or more, more preferably 150 μm or more, particularly preferably 200 μm or more, preferably 1500 μm or less, more preferably 1300 μm or less, particularly preferably 1200 μm or less, most preferably 1100 μm or less. If the thickness of the B layer is equal to or greater than the lower limit, the intermediate film is easily given a proper bending rigidity, the lowering of the sound insulation property in a high frequency region is easily suppressed, and the sufficient adhesion of the B layer to glass or the like is easily exhibited. If the thickness of the B layer is not more than the upper limit, the thickness of the interlayer film for laminated glass is not excessively increased, which is advantageous in weight reduction of laminated glass. When a plurality of B layers are stacked, the thicknesses thereof may be the same or different. When the thicknesses of the plurality of B layers are different, it is preferable that the thickness of at least 1B layer is within the above-mentioned suitable range. The thickness can be measured with a thickness gauge.

As described above, the intermediate film is preferably low in hygroscopicity from the viewpoints of adhesion to glass and adhesion control. The intermediate film of the present disclosure includes at least one a layer and at least one B layer, but the a layer is composed of a thermoplastic resin material containing a hydrophobic resin (hydrogenated product of an aromatic vinyl-conjugated diene block copolymer) as a resin component, and therefore, the hygroscopicity of the intermediate film greatly depends on the hygroscopicity of the B layer rather than the hygroscopicity of the a layer. Therefore, in particular, in the case of a structure in which the B layer is in contact with glass, the polyvinyl acetal resin composition constituting the B layer is preferably low in hygroscopicity. The water content of the sheet-like polyvinyl acetal resin composition having a thickness of 500 μm when subjected to humidity control for 48 hours at 20℃and a relative humidity of 20% is preferably 0.45% by mass or less, more preferably 0.35% by mass or less, and the water content when subjected to humidity control for 48 hours at 20℃and a relative humidity of 65% is preferably 1.80% by mass or less, more preferably 1.65% by mass or less, and still more preferably 1.45% by mass or less. The water content can be adjusted to the upper limit or less by selecting a plasticizer. The water content can be measured by the method described in examples described later.

[ layer A ]

Next, layer a will be described. The thermoplastic resin material constituting the layer a contains a thermoplastic resin or a resin composition containing a thermoplastic resin.

< thermoplastic resin Material >

The thermoplastic resin material constituting the layer a contains, as a thermoplastic resin, a hydrogenated product of a block copolymer (hereinafter, also referred to as "block copolymer (a)") having: a polymer block (a) containing 60 mol% or more of an aromatic vinyl monomer unit and a polymer block (b) containing 60 mol% or more of a conjugated diene monomer unit, wherein the content of the polymer block (a) in the hydrogenated product of the block copolymer is 25 mass% or less relative to the 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, α -methylstyrene, β -methylstyrene, 2, 6-dimethylstyrene, indene, and vinylnaphthalene. The aromatic vinyl compound may be used alone or in combination of 2 or more. Among them, styrene, α -methylstyrene, p-methylstyrene and mixtures thereof are preferable from the viewpoints of production cost and physical property balance, and styrene is more preferable.

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

The polymer block (a) may contain structural units derived from other unsaturated monomers in addition to the aromatic vinyl monomer units within a range that does not hinder the objects and effects of the present disclosure. Examples of the other unsaturated monomer include butadiene, isoprene, 2, 3-dimethylbutadiene, 1, 3-pentadiene, 1, 3-hexadiene, isobutylene, methyl methacrylate, methyl vinyl ether, N-vinylcarbazole, β -pinene, 8, 9-p-menthene, dipentene, methylene norbornene, and 2-methylene tetrahydrofuran.

The content of the other unsaturated monomer units in the polymer block (a) is less than 40 mol%, preferably less than 20 mol%, more preferably less than 15 mol%, still more preferably less than 10 mol%, particularly preferably less than 5 mol%, with respect to the total structural units constituting the polymer block (a). In a suitable embodiment of the present disclosure, the polymer block (a) is substantially free of other unsaturated monomer units described above. In the case where the polymer block (a) contains a unit derived from the above-mentioned other unsaturated monomer, the bonding form thereof is not particularly limited, and may be any of random and tapered forms.

The content of the aromatic vinyl monomer unit and the content of the other unsaturated monomer unit in the polymer block (a) in the block copolymer (A) are determined by the block copolymer (A) ¹ The H-NMR spectrum shows that the amount of the block copolymer (A) can be adjusted to a desired amount by adjusting the ratio of the monomers to be charged in the preparation of the block copolymer (A).

The block copolymer (A) may have at least 1 polymer block (a). In the case where the block copolymer (A) has 2 or more polymer blocks (a), these polymer blocks (a) may be the same or different from each other. In the present specification, "the polymer block is different" means that at least 1 of the monomer units constituting the polymer block, the weight average molecular weight, the stereoregularity, and the ratio of each monomer unit and the form of copolymerization (random, graft, block) when having a plurality of monomer units are different. The same applies to the polymer block (b) described later.

The weight average molecular weight (Mw) of the polymer block (a) contained in the block copolymer (A) is not particularly limited. The weight average molecular weight of at least 1 polymer block (a) of the polymer blocks (a) contained in the block copolymer (a) is preferably 3000 to 60000, more preferably 4000 to 50000. The block copolymer (A) has at least 1 polymer block (a) having a weight average molecular weight within the above range, and thus the mechanical strength is further improved, and good film forming properties can be easily obtained. The weight average molecular weight herein means a polystyrene-equivalent weight average molecular weight determined by Gel Permeation Chromatography (GPC).

The glass transition temperature of the polymer block (a) is preferably 120℃or lower, more preferably 110℃or lower, preferably 60℃or higher, more preferably 70℃or higher. When the glass transition temperature of the polymer block (a) is within the range of the lower limit and the upper limit, it becomes easy to control the shear storage modulus of the thermoplastic resin material constituting the layer a to a specific range, and the sound insulation property of the obtained intermediate film is improved, and the mechanical strength can be improved. The glass transition temperature of the polymer block (a) can be adjusted to a desired range by adjusting the ratio of the monomers to be charged in the preparation of the block copolymer (a) by the method described in examples to be described later.

The content of the polymer block (a) in the hydrogenated product of the block copolymer (a) [ the total content of the polymer blocks (a) in the case of having a plurality of polymer blocks (a) ] is 25 mass% or less relative to the total mass of the hydrogenated product of the block copolymer (a). The value of tan δ also varies depending on the morphology of the block copolymer (a), and in particular, in the case of taking a microphase-separated structure formed of a spherical structure, tan δ tends to be high. Since the content of the polymer block (a) in the hydrogenated product of the block copolymer (a) has a large influence in order to easily form a spherical structure, it is very advantageous in further improving the sound insulation property of the obtained intermediate film when the content of the block polymer (a) relative to the total mass of the hydrogenated product of the block copolymer (a) is adjusted to 25 mass% or less, preferably 20 mass% or less, more preferably 15 mass% or less. The content of the polymer block (a) is more preferably 14% by mass or less, still more preferably 13% by mass or less, still more preferably 12.5% by mass or less, still more preferably 11% by mass or less, and particularly preferably 9% by mass or less. From the viewpoint of sound insulation, the content of the polymer block (a) is preferably 3 mass% or more, more preferably 3.5 mass% or more. In one embodiment of the present disclosure, the content of the polymer block (a) is preferably 3 to 25% by mass. On the other hand, the content of the polymer block (a) is preferably 6 to 25% by mass, more preferably 8 to 25% by mass, and particularly preferably 10 to 25% by mass, from the viewpoint of easiness in improving the handleability and mechanical properties of the layer a. In one embodiment of the present disclosure, the content of the polymer block (a) is preferably 3.5 to 25 mass%, more preferably 4 to 15 mass%, and if the content of the polymer block (a) is within the above range, high sound insulation properties can be ensured, and the operability and mechanical properties of the obtained a layer can be improved.

The content of the polymer block (a) in the hydrogenated product of the block copolymer (A) is determined by the content of the hydrogenated product of the block copolymer (A) ¹ The H-NMR spectrum shows that the ratio of the monomers to be charged can be adjusted to a desired range in the preparation of the block copolymer (A).

Examples of the conjugated diene compound constituting the conjugated diene monomer unit contained in the polymer block (b) include isoprene, butadiene, hexadiene, 2, 3-dimethyl-1, 3-butadiene, 1, 3-pentadiene, myrcene and the like. The conjugated diene compound may be used alone or in combination of 2 or more. Among them, isoprene, butadiene, and a mixture of isoprene and butadiene are preferable, and isoprene is more preferable, from the viewpoints of easiness of obtaining, versatility, controllability of a bonding form to be described later, and the like.

As the conjugated diene compound, a mixture of butadiene and isoprene may also be used. The mixing ratio [ isoprene/butadiene ] (mass ratio) is not particularly limited, but is preferably 5/95 to 95/5, more preferably 10/90 to 90/10, still more preferably 40/60 to 70/30, particularly preferably 45/55 to 65/35. If the mixing ratio [ isoprene/butadiene ] is expressed as a molar ratio, it is preferably 5/95 to 95/5, more preferably 10/90 to 90/10, still more preferably 40/60 to 70/30, and particularly preferably 45/55 to 55/45.

The content of the conjugated diene monomer units in the polymer block (b) is 60 mol% or more, preferably 65 mol% or more, and more preferably 80 mol% or more, based on the total structural units constituting the polymer block (b). If the content of the conjugated diene monomer units is not less than the lower limit, the amount of segments exhibiting sound-insulating properties becomes sufficient, and an intermediate film excellent in sound-insulating properties can be easily obtained. The upper limit of the content of the conjugated diene monomer unit is not particularly limited. The content of the conjugated diene monomer units may be 100 mol%.

The polymer block (b) may have only 1 structural unit derived from a conjugated diene compound, or may have 2 or more structural units derived from a conjugated diene compound. As described above, the polymer block (b) in the present disclosure contains 60 mol% or more of conjugated diene monomer units. The polymer block (b) preferably contains 60 mol% or more of a structural unit derived from isoprene (hereinafter, sometimes simply referred to as "isoprene unit"), a structural unit derived from butadiene (hereinafter, sometimes simply referred to as "butadiene unit"), or the total amount of isoprene units and butadiene units as conjugated diene monomer units in each case. Thus, an intermediate film having excellent sound insulation properties can be easily obtained.

When the polymer block (b) has 2 or more conjugated diene monomer units, the bonding state thereof may be random, tapered, completely alternating, partially block-like, or a combination of 2 or more of them.

The polymer block (b) may contain structural units derived from other polymerizable monomers other than the conjugated diene monomer units within a range that does not hinder the object and effect of the present disclosure. Examples of the other polymerizable monomer include aromatic vinyl compounds such as styrene, α -methylstyrene, o-methylstyrene, m-methylstyrene, p-t-butylstyrene, 2, 4-dimethylstyrene, vinylnaphthalene and vinylanthracene, methyl methacrylate, methyl vinyl ether, N-vinylcarbazole, β -pinene, 8, 9-p-menthene, dipentene, methylene norbornene, 2-methylenetetrahydrofuran, 1, 3-cyclopentadiene, 1, 3-cyclohexadiene, 1, 3-cycloheptadiene and 1, 3-cyclooctadiene. Among them, styrene, α -methylstyrene and p-methylstyrene are preferable, and styrene is more preferable. When the polymer block (b) contains the other polymerizable monomer units, specific combinations thereof are preferably isoprene and styrene, and butadiene and styrene, and more preferably isoprene and styrene. When the polymer block (b) contains such a combination, the tan δ of the thermoplastic resin material constituting the layer a may be increased.

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

The content of the conjugated diene monomer unit and the content of the other polymerizable monomer unit in the polymer block (b) in the block copolymer (A) are determined by the block copolymer (A) ¹ The H-NMR spectrum shows that the amount of the block copolymer (A) can be adjusted to a desired amount by adjusting the ratio of the monomers to be charged in the preparation of the block copolymer (A).

When the structural unit constituting the polymer block (b) contains an isoprene unit or a butadiene unit, 1, 2-linkage, 3, 4-linkage or 1, 4-linkage may be used as the linkage form of isoprene, and 1, 2-linkage or 1, 4-linkage may be used as the linkage form of butadiene.

The total content of the 3, 4-bonded unit and the 1, 2-bonded unit (hereinafter, sometimes referred to as "vinyl bond amount") in the polymer block (b) in the block copolymer (a) is preferably 20 mol% or more, more preferably 40 mol% or more, particularly preferably 50 mol% or more. The total amount of vinyl bonds is preferably 90 mol% or less, more preferably 85 mol% or less, although not particularly limited. Here, the vinyl bond content is determined by dissolving the block copolymer (A) before hydrogenation in CDCl ₃ And measured ¹ H-NMR spectrum. In the case where the structural unit constituting the polymer block (b) is composed of only isoprene units, the vinyl bond amount is calculated from the ratio of the total peak area of isoprene units to the peak area corresponding to the 3, 4-bonding units and 1, 2-bonding units. StructureIn the case where the structural unit constituting the polymer block (b) is composed of only butadiene units, the vinyl bond amount is calculated from the ratio of the total peak area of butadiene units to the peak area corresponding to 1, 2-bond units. In the case where the structural units constituting the polymer block (b) contain an isoprene unit and a butadiene unit, the vinyl bond amount is calculated from the ratio of the total peak area of the isoprene unit and the butadiene unit to the peak area corresponding to the 3, 4-bonding unit and the 1, 2-bonding unit in the isoprene unit and the 1, 2-bonding unit in the butadiene unit.

The higher the vinyl bond content, the higher the tan δ value of the thermoplastic resin material constituting the a layer tends to be, and the sound insulation property of the obtained intermediate film can be improved by controlling the position of the peak of tan δ to a specific temperature range. The vinyl bond amount can be adjusted to a desired range by adjusting the addition amount of the organic lewis base used in the anionic polymerization for producing the block copolymer (a), for example.

The weight average molecular weight of the polymer block (b) contained in the block copolymer (a) is preferably 15000 to 800000, more preferably 50000 to 700000, even more preferably 70000 to 600000, particularly preferably 90000 to 500000, and most preferably 130000 ～ 450000 in a state before hydrogenation from the viewpoint of sound insulation and the like. Here, the weight average molecular weight means a polystyrene-equivalent weight average molecular weight obtained by Gel Permeation Chromatography (GPC), and the weight average molecular weight of the polymer block (b) means a value calculated from the difference between the weight average molecular weights before and after copolymerizing the polymer block (b).

The glass transition temperature of the polymer block (b) is preferably 10℃or lower, more preferably 0℃or lower, preferably-30℃or higher, more preferably-20℃or higher. When the glass transition temperature of the polymer block (b) is within the range of the above-mentioned lower limit and upper limit, it becomes easy to control the tan δ peak temperature of the thermoplastic resin material constituting the a layer to a specific range, and the sound insulation property of the obtained intermediate film is improved. The glass transition temperature of the polymer block (b) is measured by the method described in examples described later, and the ratio of the monomers to be charged in the preparation of the block copolymer (a) can be adjusted to a desired range.

The block copolymer (A) may have at least 1 polymer block (b) described above. In the case where the block copolymer (A) has 2 or more polymer blocks (b), these polymer blocks (b) may be the same or different from each other.

The content of the polymer block (b) in the hydrogenated product of the block copolymer (a) (in the case of having a plurality of polymer blocks (b), the total content thereof) is preferably 75 to 97% by mass based on the total mass of the hydrogenated product of the block copolymer (a). If the content of the polymer block (b) is within the above range, the hydrogenated product of the block copolymer (a) tends to have moderate flexibility or good moldability. The value of tan δ also varies depending on the morphology of the hydrogenated product of the block copolymer (a), and in particular, when a microphase-separated structure formed of a spherical structure is employed, tan δ tends to be high. Since the content of the polymer block (b) in the hydrogenated product of the block copolymer (a) has a large influence in order to easily form a spherical structure, it is very advantageous in further improving the sound insulation property of the obtained intermediate film when the content of the polymer block (b) relative to the total mass of the hydrogenated product of the block copolymer (a) is adjusted to preferably 75 to 97 mass%. The content of the polymer block (b) is more preferably 75 to 96.5% by mass, still more preferably 85 to 96% by mass, particularly preferably 90 to 96% by mass. On the other hand, the content of the polymer block (b) is preferably 75 to 94% by mass, more preferably 75 to 92% by mass, and particularly preferably 75 to 90% by mass, from the viewpoint of easiness in improving the handleability and mechanical properties of the layer a. In a preferred embodiment of the present disclosure, the content of the polymer block (b) is 75 to 96.5 mass%, and if the content of the polymer block (b) is within this range, high sound insulation can be ensured, and the operability and mechanical properties of the obtained layer a can be improved.

The content of the polymer block (b) in the hydrogenated product of the block copolymer (A) is determined by the content of the hydrogenated product of the block copolymer (A) ¹ The H-NMR spectrum shows that the ratio of the monomers to be charged can be adjusted to a desired range in the preparation of the block copolymer (A).

The bonding form of the polymer block (a) and the polymer block (b) in the block copolymer (a) is not limited, and may be any of linear, branched, radial, and a combination of 2 or more of them. Among them, the bonding form of the polymer block (ase:Sub>A) and the polymer block (B) is preferably linear, and examples thereof include ase:Sub>A diblock copolymer represented by A-B, ase:Sub>A triblock copolymer represented by A-B-A, ase:Sub>A tetrablock copolymer represented by A-B-A-B, and ase:Sub>A pentablock copolymer represented by A-B-A-B-A when the polymer block (ase:Sub>A) is represented by A and the polymer block (B) is represented by B. Among them, ase:Sub>A linear triblock copolymer or ase:Sub>A diblock copolymer is preferable, and an ase:Sub>A-B-ase:Sub>A type triblock copolymer is preferably used from the viewpoints of flexibility, ease of production, and the like.

In the present disclosure, the layer a preferably contains 1 or more hydrogenated product of the above block copolymer (a) [ hereinafter, also sometimes referred to as "hydrogenated block copolymer (a)") as a thermoplastic resin.

From the viewpoints of heat resistance, weather resistance and sound insulation, it is preferable that 80 mol% or more of the carbon-carbon double bonds of the polymer block (b) are hydrogenated (hereinafter, this value is also referred to as "hydrogenation rate") and more preferably 85 mol% or more, still more preferably 88 mol% or more, and particularly preferably 90 mol% or more. The upper limit of the hydrogenation rate is not particularly limited. The hydrogenation rate may be 99 mol% or less, or 98 mol% or less. The hydrogenation ratio was set as follows: passing before and after hydrogenation ¹ The content of carbon-carbon double bonds in the conjugated diene monomer units in the polymer block (b) was determined by H-NMR measurement, and the value calculated from the content thereof.

The weight average molecular weight of the hydrogenated block copolymer (a) as determined by gel permeation chromatography in terms of standard polystyrene is preferably 15000 to 800000, more preferably 50000 to 700000, still more preferably 70000 to 600000, particularly preferably 90000 to 500000, most preferably 130000 ～ 450000. When the weight average molecular weight of the hydrogenated block copolymer (A) is not less than the above-mentioned lower limit, the heat resistance tends to be high, and when it is not more than the above-mentioned upper limit, the moldability tends to be good.

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

When the conjugated diene monomer is used, the amount of 1, 2-linkage and the amount of 3, 4-linkage of the block copolymer (A) can be increased by adding the organic Lewis base during the anionic polymerization, and the amount of 1, 2-linkage and the amount of 3, 4-linkage, that is, the amount of vinyl linkage of the block copolymer (A) can be easily controlled by adjusting the amount of the organic Lewis base to be added. The higher the vinyl bond content, the higher the tan δ value of the thermoplastic resin material constituting the a layer tends to be, and the sound insulation property of the obtained intermediate film can be improved by controlling the position of the peak of tan δ to a specific temperature range.

The hydrogenated block copolymer (A) can be obtained by subjecting the block copolymer (A) to a hydrogenation reaction. Examples of the method for supplying the unhydrogenated block copolymer (a) to the hydrogenation reaction include the following methods: the unhydrogenated block copolymer (A) is separated from the reaction solution containing the produced block copolymer (A) and dissolved in a solvent inactive to the hydrogenation catalyst, or the unhydrogenated block copolymer (A) in the reaction solution is reacted with hydrogen in the presence of the hydrogenation catalyst. The hydrogenation rate is preferably 80 mol% or more, more preferably 85 mol% or more, still more preferably 88 mol% or more, particularly preferably 90 mol% or more.

In a preferred embodiment, the thermoplastic resin material constituting the layer A has a composition according to JIS K7244-10 in a range of-30 ℃ to 10 ℃:2005, the peak having the maximum tan δ (hereinafter, this temperature may be referred to as "tan δ peak temperature") measured by the complex shear viscosity test at a frequency of 1Hz, and the height of the tan δ peak (hereinafter, this temperature may be referred to as "tan δ peak height") is 1.5 or more.

The thermoplastic resin material constituting the layer a contained in the interlayer film for laminated glass of the present disclosure preferably has a tan δ peak temperature of-30 ℃ or higher, more preferably-25 ℃ or higher, and still more preferably-20 ℃ or higher. When the tan delta peak temperature is not less than the above lower limit, good sound insulation can be easily obtained in a frequency range of 5000Hz to 10000 Hz. On the other hand, the tan delta peak temperature is preferably 10℃or lower, more preferably 0℃or lower, and still more preferably-5℃or lower. When the tan delta peak temperature is not higher than the above-mentioned upper limit value, good sound insulation can be easily obtained in a medium frequency range of 2000Hz to 5000 Hz. Therefore, if the tan δ peak temperature is within the range of the above lower limit value and upper limit value, good sound insulation in the frequency range of 2000Hz to 10000Hz is easily brought about. Here, tan δ is also referred to as loss tangent, and is a value obtained by dividing the shear loss modulus by the shear storage modulus, and the higher the value, the higher the sound insulation property can be expected. tan δ is measured by the method described in examples described below.

For example, when the thermoplastic resin material constituting the layer a contains a hydrogenated product of the block copolymer (a) as the thermoplastic resin, the method of adjusting the content of the polymer block (a) as the hard segment in the block copolymer (a), the method of adjusting the type of the monomer constituting the polymer block (a) as the hard segment or the polymer block (b) as the soft segment, the bonding form, the glass transition temperature of each segment itself, and the like are mentioned as methods of adjusting the tan δ peak temperature. Specifically, for example, the tan δ peak temperature can be adjusted (increased) by decreasing the content of the polymer block (a) in the block copolymer (a), changing the kind or combination of monomers constituting the polymer block (b), or the like to increase the vinyl bond amount.

In the present disclosure, the tan δ peak height is preferably 1.5 or more, more preferably 2.0 or more, further preferably 2.2 or more, particularly preferably 2.4 or more. When the tan δ peak height is equal to or greater than the lower limit, desired sound insulation properties can be easily obtained. the upper limit value of the tan δ peak height is not particularly limited. the tan delta peak height is usually 5.0 or less.

As a method for increasing the tan δ peak height, for example, when the thermoplastic resin material constituting the a layer contains a hydrogenated product of the block copolymer (a) as the thermoplastic resin, there can be mentioned: and (b) forming the microphase-separated structure into a spherical structure, increasing the vinyl bond content in the polymer block (b), and the like.

The thermoplastic resin material constituting the layer a contains the hydrogenated block copolymer (a) as a thermoplastic resin in an amount of preferably 60 mass% or more, more preferably 70 mass% or more, still more preferably 80 mass% or more, relative to the total mass of the thermoplastic resin material. The content of the hydrogenated block copolymer (a) in the layer a is also preferably 90 mass% or more, 95 mass% or more, 99 mass% or more, 99.9 mass% or more, 99.99 mass% or more, or 100 mass% or more, based on the total mass of the thermoplastic resin material. The thermoplastic resin material constituting the layer a may contain other thermoplastic resins (for example, additives such as a crystallization nucleating agent, hydrogenated coumarone/indene resins, hydrogenated rosin-based resins, hydrogenated terpene resins, alicyclic hydrogenated petroleum resins, and other hydrogenated resins, tackifying resins such as aliphatic resins formed from olefins and diene polymers, hydrogenated polyisoprene, hydrogenated polybutadiene, butyl rubber, polyisobutylene, polybutene, polyolefin-based elastomers, specifically ethylene-propylene copolymers, ethylene-butene copolymers, propylene-butene copolymers, polyolefin-based resins, olefin-based polymers, polyethylene-based resins, and the like) in addition to the hydrogenated block copolymer (a) as needed and within a range that does not impair the effects of the present disclosure. It is particularly preferable that the thermoplastic resin material constituting the layer a is formed of the hydrogenated block copolymer (a) as the thermoplastic resin.

In the interlayer film for laminated glass of the present disclosure, the thickness of the layer 1A is preferably 100 μm or more and 400 μm or less. The optimal thickness of the a layer varies depending on the thickness of the other layers constituting the intermediate film (for example, the B layer) and the storage modulus of each layer, but the thicker the a layer is, the higher the sound insulation, and the storage modulus of the entire intermediate film tends to be lowered. Thus, if the thickness of the layer a 1 is greater than 400 μm, the frequency region due to the overlapping effect of the laminated glass tends to be higher than 6000Hz, and the sound insulation performance in the frequency region of 6000Hz or more may be significantly reduced. The thickness of the layer a layer 1 is more preferably 350 μm or less, particularly preferably 300 μm or less, from the viewpoint of further improving the sound insulation property in the high frequency region. When the thickness of the a layer is smaller than 100 μm, the sound insulation property becomes low, the energy storage modulus of the entire interlayer becomes high, and the frequency region due to the superposition effect may become a middle frequency region, and the sound insulation property may be remarkably reduced in the middle frequency region of 4000 to 6000 Hz. In particular, since the sound-insulating property in this frequency region is practically important and the effect of improving the sound-insulating property is reduced with a decrease in the thickness of the a layer, the thickness of the a layer 1 layer is more preferably 120 μm or more, particularly preferably 150 μm or more. The total thickness of the plurality of a layers is preferably 950 μm or less, more preferably 700 μm or less. The thickness of each of the plurality of a layers may be the same or different. When the thicknesses of the plurality of a layers are different, it is preferable that the thickness of at least 1 a layer is within the above-mentioned suitable range. The thickness can be measured with a thickness gauge. The plurality of a layers may be made of the same thermoplastic resin material or different thermoplastic resin materials.

The thermoplastic resin material constituting the layer a may contain, as other components, an antioxidant, an ultraviolet absorber, a light stabilizer, an antiblocking agent, a pigment, a dye, a heat insulator, or the like, as required.

As for the antioxidant, ultraviolet absorber, light stabilizer, heat insulating material, etc., the same materials as those described in the above description of the polyvinyl acetal resin composition can be used, and the appropriate agent or material in the layer a may be the same as or different from the appropriate agent or material in the polyvinyl acetal resin composition.

As the anti-blocking agent, inorganic particles and organic particles can be mentioned. Examples of the inorganic particles include oxides, hydroxides, sulfides, nitrides, halides, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylates, silicates, titanates, borates, and hydrous compounds thereof of group IA, group IIA, group IVA, group VIIA, group VIIIA, group IB, group IIB, group IIIB, and group IVB elements, and composite compounds and natural mineral particles containing the same as main components. The main component herein means the component with the highest content. Examples of the organic particles include a fluororesin, a melamine resin, a styrene-divinylbenzene copolymer, an acrylic resin silicone, and crosslinked products thereof.

In the interlayer film for laminated glass of the present disclosure, these additives may be contained in 1 or more layers selected from the group consisting of 1 or more a layers and 1 or more B layers. In the case where the additive is contained in 2 or more layers selected from the above groups, the same additive may be contained in these layers or different additives may be contained in these layers.

[ method for producing interlayer film for laminated glass ]

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

For example, in the case of a composition having a layer B laminated on both surfaces of a layer a, a layer B may be produced by uniformly kneading a polyvinyl acetal resin composition constituting the layer B, then producing the layer B by a known film-forming method (for example, extrusion, calendaring, pressurizing, casting or inflation), producing a layer a from a thermoplastic resin material constituting the layer a by the same method, and laminating them by press molding or the like, or may be produced by coextruding the layer B, the layer a and other desired layers.

In the case where the interlayer film for laminated glass of the present disclosure has a structure having a plurality of a layers and layers sandwiched between a layers are present, for example, 2 or more interlayer film sheets having a structure in which B layers are laminated on both sides of a layer can be used, and the interlayer film can be produced as follows: the polyvinyl acetal resin composition constituting the B layer is kneaded uniformly, and then the B layer is produced by the known film-forming method, the a layer is produced from the thermoplastic resin material constituting the a layer in the same manner, and these are laminated by press molding or the like, or the B layer, the a layer and other desired layers are co-extruded to produce the B layer. An interlayer film for laminated glass can also be produced by laminating the above-mentioned 2 or more interlayer film and layer 3 (layer C) according to a method of manufacturing laminated glass described later. The lamination thereof may be performed simultaneously with the lamination of the glass of the outermost layer of the laminated glass.

In addition, for example, layer 3 (layer C) may also be used. When the C layer is used, an intermediate film having a structure in which an a layer and a B layer are laminated on both sides in contact with the C layer (for example, B layer/a layer/C layer/a layer/B layer), an intermediate film having a structure in which a B layer/a layer/B layer are laminated in this order on both sides in contact with the C layer (for example, B layer/a layer/B layer/C layer/B layer/a layer/B layer), or the like may be used, and each layer may be laminated after being formed, or may be produced by coextrusion of the a layer, B layer, C layer, and other desired layers.

Among known film forming methods, a method of producing an interlayer film or an interlayer film for laminated glass using an extruder is particularly suitable. The resin temperature (temperature of the resin material or the resin composition) at the time of extrusion is preferably 150 ℃ or higher, more preferably 170 ℃ or higher, preferably 250 ℃ or lower, more preferably 230 ℃ or lower. If the resin temperature at the time of extrusion is within the range of the above-mentioned lower limit value and upper limit value, decomposition of the resin or the like contained in the resin material or the resin composition is less likely to occur, and thus degradation of the resin or the like is less likely to occur, and stable discharge from the extruder is easy. In order to effectively remove volatile substances, it is preferable to remove volatile substances from the vent of the extruder by depressurizing.

The thickness of each 1 layer of the a layer and the B layer is as described above.

In the present disclosure, the lamination configuration in the interlayer film for laminated glass can be appropriately determined according to the purpose. The laminate structure may be a laminate structure such as B layer/a layer/B layer/a layer, or B layer/a layer/B layer, as shown in fig. 1, or B layer/a layer/B layer, as shown in fig. 2. Accordingly, in one embodiment of the present disclosure, the interlayer film for laminated glass includes a layer a and a layer B in the order of B layer/a layer/B layer. In addition, 2 sets of interlayer films may be sandwiched between 3 sheets of glass.

The a layer in the present disclosure may impart sound insulation to the laminated glass. In general, the layer imparting soundproof properties has a low glass transition temperature and may have tackiness, and therefore, when the layer a is a layer imparting soundproof properties from the viewpoint of handleability of the intermediate film, it is preferable that the layer a is sandwiched between layers B. In this case, in one aspect of the present disclosure, it is preferable that the interlayer film for laminated glass includes the layer a having a thickness of 100 μm or more and 400 μm or less, and the layer B having a thickness of 200 μm or more and 1500 μm or less, which is laminated on both sides of the layer a.

In the case where the layers a, B, and/or C each include 2 or more layers, the components constituting the layers a, B, and C may be the same or different from each other, and the thicknesses may be different from each other.

The C layer that may be included in the interlayer film for laminated glass of the present disclosure may be a layer that includes a known resin as a resin component. As the resin contained in the C layer, for example, there can be used: 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, styrene-based thermoplastic elastomer, ethylene-vinyl acetate copolymer, polymethacrylic acid, or poly (meth) acrylate, ethylene- (meth) acrylate copolymer, and the like. The C layer may contain additives such as plasticizers, antioxidants, ultraviolet absorbers, light stabilizers, antiblocking agents, pigments, dyes, heat insulating materials, and the like, as needed, and an inorganic multilayer film, a metal conductive layer, and the like may be formed on at least a part of the C layer.

The C layer may be a layer such as an inorganic multilayer film or a metal conductive layer, instead of a layer containing a known resin as a resin component.

In addition, in the intermediate film for laminated glass of the present disclosure, it is preferable to form a concave-convex structure on the surface by a conventionally known method such as melt fracture or embossing. The shape of the concave-convex structure is not particularly limited, and a conventionally known shape can be adopted.

In the present disclosure, the total thickness of the interlayer film for laminated glass including the a layer and the B layer is preferably 0.4mm or more, more preferably 0.5mm or more, preferably 2.5mm or less, more preferably 2.0mm or less, and further preferably 1.5mm or less. If the total thickness is not less than the above-mentioned lower limit, the handleability in producing a laminated glass is excellent, and if the total thickness of the interlayer is not more than the above-mentioned upper limit, the weight of the laminated glass as a whole is reduced, and the cost of the interlayer can be reduced, which is preferable.

On the other hand, in the case of a 5-layer structure such as B layer/a layer/B layer, in particular, a structure excellent in sound insulation can be formed. The total thickness of the intermediate film having such a structure is preferably 0.8mm or more, more preferably 1.1mm or more, preferably 4.0mm or less, more preferably 3.0mm or less, and still more preferably 2.5mm or less. If the total thickness is not less than the above-mentioned lower limit, a composition having particularly excellent sound insulation properties of the laminated glass can be obtained, and if the total thickness of the interlayer is not more than the above-mentioned upper limit, the weight of the laminated glass as a whole is reduced, and the cost of the interlayer can be reduced, which is preferable.

[ laminated glass ]

As described above, by using the interlayer film for laminated glass of the present disclosure, laminated glass excellent in sound insulation can be obtained. Accordingly, the present disclosure also targets a laminated glass in which the interlayer film for laminated glass of the present disclosure is sandwiched between 2 sheets of glass. The laminated glass of the present disclosure is derived from the interlayer film for laminated glass of the present disclosure and has excellent sound insulation, and therefore is suitable for use as 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. Here, the vehicle in the present disclosure refers to a train, an electric car, an automobile, a ship, an airplane, or the like.

When the laminated glass of the present disclosure is used for glass for a head-up display, the cross-sectional shape of the interlayer is preferably a shape in which one end face side is thick and the other end face side is thin. In this case, the cross-sectional shape may be a shape of a wedge shape as a whole, which becomes thinner in order from one end face side to the other end face side, or a shape of a wedge shape as a part of a cross-section, which becomes thinner in order from the arbitrary position to the other end face side, with the same thickness from one end face to an arbitrary position between the end face and the other end face, and may have an arbitrary cross-sectional shape irrespective of the position, as long as it is not a problem in production. The layers with the changed section thickness may be all layers or only a part of layers.

In the laminated glass of the present disclosure, 2 sheets of glass are generally used at the outermost side. The glass is not particularly limited, and for example, inorganic glass, organic glass, or a combination thereof may be used. Examples of the inorganic glass include float glass, polished glass, embossed glass, wire glass, and heat-ray absorbing glass. Examples of the material constituting the organic glass include an acrylic resin (e.g., polymethyl methacrylate resin) and a polycarbonate resin. The glass may be any of colorless, colored, transparent, or non-transparent.

The thickness of the glass is not particularly limited, but is preferably 100mm or less. In addition, since the interlayer film of the present disclosure has excellent sound insulation, even when thinner glass is used, high sound insulation can be exhibited, and thus, weight reduction of the laminated glass can be achieved. From the viewpoint of weight reduction, the thickness of at least 1 glass is preferably 3.0mm or less, more preferably 2.5mm or less, further preferably 2.0mm or less, particularly preferably 1.8mm or less. In particular, by setting the thickness of one glass to 1.8mm or more and the thickness of the other glass to 1.8mm or less and the difference between the thicknesses of 2 glass sheets to 0.2mm or more, laminated glass can be produced in which the thickness and weight of the laminated glass are reduced without impairing the bending strength. The difference in thickness between the 2 glasses is preferably 0.5mm or more, and may be 1.0mm or more, and may be 1.5mm or less.

In the side window glass for an automobile, a laminated glass having a structure in which the thicknesses of the glass on the vehicle exterior side and the glass on the vehicle interior side are equal to each other is mainly used, and in this case, an interlayer film having high sound insulation properties of the present disclosure may be suitably used.

The sound insulation of the laminated glass can be evaluated by the loss factor obtained by the damping test of the laminated glass by the center excitation method described in examples, and it can be said that the higher the maximum loss factor at the 2-order resonance frequency of the laminated glass, the higher the sound insulation of the laminated glass.

The maximum loss factor at the 2-time resonance frequency of the laminated glass is preferably 0.30 or more, more preferably 0.40 or more, and still more preferably 0.50 or more.

[ method for producing laminated glass ]

The laminated glass of the present disclosure can be produced by a known method. Examples of such a method include a method using a vacuum laminator device, a method using a vacuum bag, a method using a vacuum ring, a method using a roll, and the like. In addition, a method of additionally putting the material into an autoclave process may be performed after the temporary press-bonding.

In the method using the vacuum laminator apparatus, for example, a known apparatus used in the manufacture of solar cells is used in a 1×10 ^-6 MPa or more and 3×10 ^-2 Laminating is performed at a temperature of 100 ℃ to 200 ℃ (particularly 130 ℃ to 170 ℃), under reduced pressure of MPa or less.

Methods using vacuum bags or vacuum rings are described, for example, in European patent No. 1235683, for example, in about 2X 10 ^-2 Lamination is performed at a pressure of 130 ℃ to 145 ℃ under MPa.

As a method of using the roll, for example, the following methods can be mentioned: after the first temporary pressure bonding is performed at a temperature equal to or lower than the flow start temperature of the polyvinyl acetal resin, the pressure bonding or temporary pressure bonding is further performed under a condition close to the flow start temperature. Specifically, for example, the following methods are mentioned: the pressure-bonding or temporary pressure-bonding is performed by heating to 30 ℃ or more and 100 ℃ or less with an infrared heater or the like, then degassing with a roller, and then temporarily pressure-bonding with the degassing, further heating to 50 ℃ or more and 150 ℃ or less, and then pressure-bonding with a roller.

The autoclave process which is performed additionally after the temporary press-bonding is performed for a time of 0.5 to 2 hours at a temperature of 120 to 160 ℃ under a pressure of 1 to 15MPa, for example, depending on the thickness and composition of the laminated glass.

Examples

Hereinafter, the present disclosure will be specifically described with reference to examples, reference examples and comparative examples, but the present disclosure is not limited to these examples. In the following examples, "%" means "% by mass" unless otherwise specified.

In the following examples, reference examples and comparative examples, as a polyvinyl butyral (hereinafter referred to as "PVB") resin, the following were used: polyvinyl alcohol having the same viscosity average degree of polymerization as the target viscosity average degree of polymerization (the viscosity average degree of polymerization measured based on JIS K6726 "polyvinyl alcohol test method") was acetalized with n-butyraldehyde in the presence of a hydrochloric acid catalyst.

Measurement method or evaluation method

1. Tan delta peak temperature and tan delta peak height of thermoplastic resin material constituting layer a

The thermoplastic resin material constituting the layer A was pressurized at 230℃and a pressure of 10MPa for 3 minutes to prepare a single-layer sheet having a thickness of 1.0 mm. The single-layer sheet was cut into a disk shape, and the disk was used as a test piece.

According to JIS K7244-10:2005, a complex shear viscosity test was performed at a frequency of 1Hz to determine the temperature of the peak at which tan δ of the thermoplastic resin material constituting the a layer becomes maximum and the height of the tan δ peak.

2. Content of Polymer Block (a)

The thermoplastic resin material (hydrogenated product of block copolymer, hereinafter also referred to as "hydrogenated block copolymer") constituting the layer A is dissolved in CDCl ₃ In (1) measuring ¹ H-NMR spectrum [ apparatus: JNM-Lambda 500 (manufactured by Japanese electronics Co., ltd.), measurement temperature: 50 DEG C]The content of the polymer block (a) contained in the hydrogenated block copolymer was calculated from the peak intensity derived from styrene.

3. Glass transition temperature of thermoplastic resin material constituting layer A

The hydrogenated block copolymer (thermoplastic resin material constituting the layer a) used in examples and comparative examples represents the glass transition temperature derived from the monomer constituting the polymer block (a) and the glass transition temperature derived from the monomer constituting the polymer block (b). Thus, differential scanning calorimetry (DSC, manufactured by Seiko Instruments Inc.) was performed to determine the glass transition temperature of the polymer block (a) and the glass transition temperature of the polymer block (b) contained in the hydrogenated block copolymer as the glass transition temperatures of the hydrogenated block copolymers, respectively. In the measurement, the temperature of the inflection point of the measurement curve was read by increasing the temperature from-120℃to 150℃at a temperature increase rate of 10℃per minute.

4. Water content of polyvinyl acetal resin composition

The polyvinyl acetal resin compositions in the form of sheets having a thickness of 500 μm prepared in each of the reference examples were subjected to humidity control at 20℃and a relative humidity of 20% for 48 hours or at 20℃and a relative humidity of 65% for 48 hours. The moisture content of the sheet-like polyvinyl acetal resin composition after the humidity adjustment was measured by Mitsubishi Chemical Analytech Co., ltd.

5. Haze of laminated glass

A laminated glass was produced in accordance with the following procedure, and the haze was measured based on JIS K7105.

Each of the intermediate films produced in examples and comparative examples was cut into 50mm in the longitudinal direction and 40mm in the transverse direction, and left standing at 20℃under an atmosphere having a relative humidity of 20% for 48 hours, and sandwiched between 2 commercially available float glasses (50 mm in the longitudinal direction and 40mm in the transverse direction and 3mm in thickness). After temporary press-bonding was performed under a reduced pressure of 30kPa at 100℃for 20 minutes by a vacuum laminator apparatus, press-bonding was performed under a pressure of 1.2MPa at 140℃for 60 minutes by an autoclave to produce laminated glass. Haze measurement was performed 1 day after and 30 days after the production of the laminated glass.

6. Sound-insulating Property (loss coefficient in 2-times resonance frequency of laminated glass)

The intermediate films produced in examples and comparative examples were cut into 300mm in the longitudinal direction and 25mm in the transverse direction, and sandwiched between 2 commercially available float glasses (300 mm in the longitudinal direction and 25mm in the transverse direction and 1.9mm in the thickness). After temporary press-bonding was performed under a reduced pressure of 30kPa at 100℃for 20 minutes by a vacuum laminator apparatus, press-bonding was performed under a pressure of 1.2MPa at 140℃for 60 minutes by an autoclave to prepare laminated glass. After the laminated glass was produced for 1 week, the center of the lower surface (300 mm. Times.25 mm surface) of the produced laminated glass was fixed to the tip of an excitation force detector built in the impedance head of an excitation device (poweramplifier/model 371-A) in a mechanical impedance device (manufactured by Kogyo corporation; mass-eliminating amplifier: masscancela-5500; channel data station: DS-2100). Vibration was applied to the center portion of the laminated glass at 20 ℃ in the frequency range of 0 to 10000Hz, and the vibration force and acceleration waveform of the vibration point (center portion of the laminated glass to which vibration was applied) were detected, thereby performing a damping test of the laminated glass by the center vibration method. The mechanical impedance of the excitation point was obtained based on the obtained excitation force and the velocity signal obtained by integrating the acceleration signal, and the loss coefficient of the laminated glass was obtained from the frequency and half-value width of the peak shown in the impedance curve obtained by taking the horizontal axis as the frequency and the vertical axis as the mechanical impedance (2 times).

7. Refractive index of plasticizer

The refractive index of the plasticizer was measured using an abbe refractometer.

Reference example 1

As the polyvinyl acetal resin composition, used are: a composition obtained by mixing 38.8 parts by mass of dipropylene glycol dibenzoate (DPGDB) as a plasticizer with 100 parts by mass of a PVB resin (degree of acetalization 70 mol%, content of vinyl acetate unit 0.9 mol%, and viscosity average polymerization degree of polyvinyl alcohol as a raw material approximately 1700). The polyvinyl acetal resin composition was extrusion molded to prepare a sheet having a thickness of 500. Mu.m.

The moisture content of the obtained sheet was measured. The results are shown in Table 1.

Reference examples 2 to 6

A sheet was produced in the same manner as in example 1, except that the plasticizer described in table 1 was used instead of dipropylene glycol dibenzoate, and the water fraction was measured. The results are shown in Table 1.

Here, PCL 205U refers to polycaprolactone diol "Praxel 205U" manufactured by Daicel Co., ltd. PCL 205U is a compound having no aromatic ring in the molecular structure and a hydroxyl group.

TABLE 1

As shown in table 1, the compositions (reference examples 1 to 4) corresponding to the polyvinyl acetal resin compositions in the present disclosure have low hygroscopicity equivalent to that of 3G8 (reference example 5) commonly used under both low humidity conditions of 20 ℃ and 20% relative humidity and high humidity conditions of 20 ℃ and 65% relative humidity. On the other hand, the polyvinyl acetal resin composition of reference example 6 had higher hygroscopicity under both low-humidity conditions and high-humidity conditions. From these results, it was found that the compositions of reference examples 1 to 4 containing a specific plasticizer provided a resin layer that was less susceptible to the effects of moisture. Such a resin layer may have excellent adhesion to glass and adhesion control.

Example 1

According to the compositions shown in table 2, as the thermoplastic resin material constituting the a layer, the following were used: a linear hydrogenated styrene/isoprene/styrene triblock copolymer having 8 mass% of styrene units and 92 mass% of isoprene units and having a tan delta peak temperature of-11.8℃and a tan delta peak height of 2.5 (hydrogenation ratio: 93 mol%, weight average molecular weight: 258000).

Further, as the polyvinyl acetal resin composition constituting the layer B, the following was used: a resin composition comprising a PVB resin (having a degree of acetalization of 70 mol%, a vinyl acetate unit content of 0.9 mol%, and a viscosity average polymerization degree of about 1700) and a plasticizer (dipropylene glycol dibenzoate; DPGDB) (the amount of the plasticizer per 100 parts by mass of the PVB resin: 38.8 parts by mass).

The thermoplastic resin material constituting the layer A and the polyvinyl acetal resin composition constituting the layer B were respectively extrusion-molded to produce 1 sheet of the layer A having a thickness of 250 μm and 2 sheets of the layer B having a thickness of 250 μm.

The layer A was sandwiched between 2 layers B, and the film was press-molded at 100℃to obtain an intermediate film having 3 layers of layer B/layer A/layer B. Table 2 shows the physical properties and the evaluation results of the obtained intermediate film.

Examples 2 to 3

An intermediate film was produced in the same manner as in example 1, except that the B layer of example 1 was replaced with a B layer having a different plasticizer as shown in table 2. Table 2 shows the physical properties and the evaluation results of the obtained intermediate film.

Example 4

The film was formed to have B layers (denoted as "B" in the table) of different thicknesses as shown in Table 2 ₂ Layer ") as a central layer, B layer/a layer/B ₂ An interlayer film was produced in the same manner as in example 1, except that the 5-layer structure of layer/a-layer/B-layer was used instead of the 3-layer structure of layer B/a-layer/B-layer. Table 2 shows the physical properties and the evaluation results of the obtained intermediate film.

Comparative examples 1 to 4

In the table, PABBE represents bis (2-butoxyethyl) phthalate, TOTM represents tris (2-ethylhexyl) trimellitate.

TABLE 2

As is clear from table 2, when a specific plasticizer was used (examples 1 to 4), the haze after 1 day of production of the laminated glass was sufficiently low, and it was possible to obtain laminated glass having good optical characteristics with no or substantially no increase in haze even with the lapse of time. It was also found that the laminated glasses of examples 1 to 4 also had high loss factors, and therefore were excellent in sound insulation. Further, as described in table 1, the polyvinyl acetal resin compositions in the present disclosure have low hygroscopicity, so that the interlayer films of examples 1 to 4 are excellent in adhesion to glass, and can also achieve adhesion control to glass.

On the other hand, when a plasticizer having no specific SP value was used (comparative examples 1 to 3), the haze increased significantly with the lapse of time. When 3G8 was used (comparative example 1), the haze after 1 day after the production of the laminated glass was also high, and the optical characteristics were poor.

In addition, when a plasticizer having a specific SP value but no aromatic ring and a hydroxyl group in the molecular structure is used (comparative example 4), the resin composition containing the plasticizer has higher hygroscopicity as described in table 1, and therefore, the interlayer film of comparative example 4 has poor adhesion to glass, and it is difficult to achieve adhesion control to glass.

Industrial applicability

The intermediate film of the present disclosure has sufficiently high transparency and sound insulation, and can achieve excellent adhesion and adhesion control between the intermediate film and glass. Such an interlayer film of the present disclosure may be suitably used for 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.

Description of the reference numerals

Layer 1a A

Layer 1b A

2a B layers

2b B layers

Layer 3B (B) ₂ Layer(s)

Claims

1. A laminated glass comprising a laminated glass interlayer film, wherein 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 is sandwiched between 2 sheets of glass,

The interlayer film for laminated glass comprises at least one layer A made of a thermoplastic resin material and at least one layer B made of a polyvinyl acetal resin composition,

the thermoplastic resin material contains, as a thermoplastic resin, a hydrogenated product of a block copolymer having: a polymer block a comprising 60 mol% or more of aromatic vinyl monomer units and a polymer block b comprising 60 mol% or more of conjugated diene monomer units, the content of the polymer block a in the hydrogenated product of the block copolymer being 25 mass% or less relative to the total mass of the hydrogenated product of the block copolymer,

the polyvinyl acetal resin composition contains a polyvinyl acetal resin and a plasticizer having an aromatic ring in a molecular structure, the content of the plasticizer is 0.5 to 100 parts by mass relative to 100 parts by mass of the polyvinyl acetal resin, and the SP value of the plasticizer is 10.0 (cal/cm ³ ) ^1/2 The plasticizer has a hydroxyl value of 10.0mgKOH/g or less.

2. The laminated glass according to claim 1, wherein the plasticizer does not have hydroxyl groups in a molecular structure.

3. The laminated glass according to claim 1 or 2, wherein the plasticizer has a refractive index n _D Is 1.50 or more.

4. The laminated glass according to claim 1 or 2, wherein the polyvinyl acetal resin composition in a sheet form having a thickness of 500 μm has a water content of 1.80 mass% or less when subjected to humidity control at 20 ℃ for 48 hours at a relative humidity of 65%.

5. The laminated glass according to claim 1 or 2, wherein the polyvinyl acetal resin composition contains 1 or more plasticizers selected from the group consisting of benzoate esters, aromatic phosphate esters, and phthalate esters as the plasticizer.

6. The laminated glass according to claim 1 or 2, wherein the polyvinyl acetal resin composition further contains 1 or more magnesium salts selected from the group consisting of magnesium salts of carboxylic acids having 2 to 12 carbon atoms.

7. The laminated glass according to claim 1 or 2, wherein the thermoplastic resin material has a composition according to JIS K7244-10 in a range of-30 ℃ or more and 10 ℃ or less: 2005, the peak having a maximum tan delta measured by a complex shear viscosity test at a frequency of 1Hz, the tan delta peak having a height of 1.5 or more.

8. The laminated glass according to claim 1 or 2, comprising the a layer having a thickness of 100 μm or more and 400 μm or less, and the B layer having a thickness of 200 μm or more and 1500 μm or less, which is laminated on both sides of the a layer and 1 layer.

9. The laminated glass according to claim 1 or 2, comprising the a layer and the B layer in the order of B layer/a layer/B layer.