WO2015147218A1

WO2015147218A1 - Intermediate film for laminated glass and laminated glass

Info

Publication number: WO2015147218A1
Application number: PCT/JP2015/059496
Authority: WO
Inventors: 中村　岳博; 善永林; 加藤　昇; 成裕乾
Original assignee: 積水化学工業株式会社
Priority date: 2014-03-28
Filing date: 2015-03-26
Publication date: 2015-10-01
Also published as: JPWO2015147218A1

Abstract

Provided is an intermediate film for laminated glass, said intermediate film being capable of increasing transparency, heat-shielding properties, and toughness. This intermediate film for laminated glass comprises: a plurality of first thermoplastic resin layers containing a polyvinyl acetal resin and a plasticiser; and a plurality of second thermoplastic resin layers containing a thermoplastic resin. The intermediate film has a multi-layered structure in which the plurality of first thermoplastic resin layers and the plurality of second thermoplastic resin layers are laminated alternately in the thickness direction. The absolute value of the difference between the particular refractive indices of the first thermoplastic resin layers and the second thermoplastic resin layers is 0.1 or more, and the sum total of the plurality of first thermoplastic resin layers and the plurality of second thermoplastic resin layers laminated in the thickness direction is 500 layers or more.

Description

Laminated glass interlayer film and laminated glass

The present invention relates to an interlayer film for laminated glass used for laminated glass. Moreover, this invention relates to the laminated glass using the said intermediate film for laminated glasses.

Laminated glass is superior in safety even if it is damaged by an external impact and the amount of glass fragments scattered is small. For this reason, the said laminated glass is widely used for a motor vehicle, a rail vehicle, an aircraft, a ship, a building, etc. As the laminated glass, a laminated glass obtained by sandwiching an interlayer film for laminated glass between a pair of glass plates is known.

In recent years, there is an increasing demand for improving heat shielding properties in laminated glass for automobiles and buildings. Among the light rays, the energy amount of infrared rays having a wavelength of 780 nm or more is as small as about 10% of the energy amount of ultraviolet rays. However, the thermal effect of infrared rays is great, and when infrared rays are absorbed by a substance, the temperature rises. For this reason, infrared rays are called heat rays.

By blocking the infrared rays that have a large thermal effect on the windshields and side windows of automobiles, glass windows and glass doors of buildings, it is possible to increase the heat insulation and suppress the temperature rise inside the cars and buildings. . Therefore, a method for effectively blocking infrared rays has been studied.

For example, heat-cut glass is known as a glass that effectively blocks infrared rays having a large thermal action. This heat ray cut glass is obtained by performing a metal / metal oxide multilayer coating on the surface of a glass plate by metal vapor deposition or sputtering for the purpose of directly blocking sunlight. The multilayer coating film has low scratch resistance and inferior chemical resistance. For this reason, conventionally, for example, in order to obtain a laminated glass, a method of obtaining a laminated glass by arranging a multilayer coating film between a glass plate and an intermediate film such as a plasticized polyvinyl butyral resin film has been adopted. .

However, the laminated glass on which the multilayer coating film is disposed is expensive, the visible light transmittance is lowered due to the multilayer coating film, and the transparency is impaired, or the material constituting the multilayer coating film is visible light. There is a problem that coloring occurs due to absorption in the region. Furthermore, the adhesion between the multilayer coating film and the intermediate film may be reduced, and the intermediate film may be peeled off or whitened.

On the other hand, Patent Document 1 and Patent Document 2 disclose a laminated glass in which a polyester film obtained by thin-film coating or vapor deposition of metal and / or metal oxide is disposed between plasticized polyvinyl butyral resin films.

Also, an interlayer film in which a heat ray absorbing material such as inorganic particles is dispersed is known as an interlayer film that transmits visible light and blocks infrared rays. Patent Document 3 discloses an interlayer film for laminated glass in which metal oxide particles having heat shielding properties such as tin-doped indium oxide particles (ITO particles) or antimony-doped tin oxide particles (ATO particles) are dispersed.

JP-A-57-106543 Japanese Unexamined Patent Publication No. 64-36442 WO01 / 25162A1

In the laminated glass described in

Patent Documents

1 and 2, peeling is likely to occur at the interface between the plasticized polyvinyl butyral resin film and the polyester film. For this reason, there is a problem in adhesiveness that is important when using laminated glass as an integrated composite material.

In the laminated glass using the interlayer film described in Patent Document 3, the heat shielding property may not be sufficiently high, and further, it may turn yellow when irradiated with light, and the visible light transmittance may decrease. For this reason, it is anticipated that a problem will arise when using laminated glass for an automotive windshield that has a lower limit on the visible light transmittance. Furthermore, in an intermediate film formed of a resin having high flexibility and toughness such as polyvinyl butyral resin, mechanical properties such as toughness and adhesiveness are likely to deteriorate due to the effect of added particles, which is an important characteristic of the intermediate film. The safety that is.

An object of the present invention is to provide an interlayer film for laminated glass that can enhance transparency, heat shielding properties and toughness. Another object of the present invention is to provide a laminated glass using the interlayer film for laminated glass.

According to a wide aspect of the present invention, it comprises a plurality of first thermoplastic resin layers containing a polyvinyl acetal resin and a plasticizer, and a plurality of second thermoplastic resin layers containing a thermoplastic resin, The absolute value of the difference in intrinsic refractive index between one thermoplastic resin layer and the second thermoplastic resin layer is 0.1 or more, and the plurality of first thermoplastic resin layers and the plurality of second layers The thermoplastic resin layers are alternately laminated in the thickness direction, and the total number of laminated layers in the thickness direction of the plurality of first thermoplastic resin layers and the plurality of second thermoplastic resin layers is 500 or more. An interlayer film for laminated glass is provided.

In a specific aspect of the interlayer film for laminated glass according to the present invention, the thickness of each of the plurality of first thermoplastic resin layers is not less than 50 nm and not more than 700 nm, and the plurality of second heats. The thickness per layer of all the plastic resin layers is 50 nm or more and 700 nm or less.

In a specific aspect of the interlayer film for laminated glass according to the present invention, a first thermoplastic resin layer having a thickness different from that of one or two second thermoplastic resin layers in contact with one or both surfaces, Multi-layer structure in which one or two first thermoplastic resin layers in contact with one or both surfaces and second thermoplastic resin layers having different thicknesses are alternately stacked in total in the thickness direction. Including parts.

In a specific aspect of the interlayer film for laminated glass according to the present invention, the reflectance of incident light is 20% or less at an incident wavelength of 350 nm to 800 nm and 50% or more at an incident wavelength of 800 nm to 2500 nm.

According to a wide aspect of the present invention, the first laminated glass member, the second laminated glass member, and the interlayer film for laminated glass described above are provided, and the first laminated glass member and the second laminated glass are provided. There is provided a laminated glass in which the interlayer film for laminated glass is disposed between the members.

The interlayer film for laminated glass according to the present invention includes a plurality of first thermoplastic resin layers containing a polyvinyl acetal resin and a plasticizer, and a plurality of second thermoplastic resin layers containing a thermoplastic resin. And the absolute value of the difference in intrinsic refractive index between the first thermoplastic resin layer and the second thermoplastic resin layer is 0.1 or more, and the plurality of first thermoplastic resin layers and the plurality of first thermoplastic resin layers The second thermoplastic resin layers are alternately laminated in the thickness direction, and the number of laminated layers in the total thickness direction of the plurality of first thermoplastic resin layers and the plurality of second thermoplastic resin layers. Since it is 500 layers or more, transparency, heat insulation, and toughness can be improved.

FIG. 1 is a partially cutaway sectional view showing an interlayer film for laminated glass according to a first embodiment of the present invention. FIG. 2 is a partially cutaway sectional view showing an interlayer film for laminated glass according to a second embodiment of the present invention. FIG. 3 is a partially cutaway sectional view showing an interlayer film for laminated glass according to a third embodiment of the present invention. FIG. 4 is a partially cutaway cross-sectional view showing an interlayer film for laminated glass according to a fourth embodiment of the present invention. FIG. 5 is a partially cutaway cross-sectional view showing a laminated glass including the intermediate film shown in FIG. 6 is a partially cutaway cross-sectional view showing a laminated glass including the intermediate film shown in FIG. FIG. 7 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Example 1. FIG. 8 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Example 2. FIG. 9 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Example 3. FIG. 10 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Example 4. FIG. 11 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Example 5. FIG. 12 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Comparative Example 2. FIG. 13 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Comparative Example 3. FIG. 14 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Comparative Example 4. FIG. 15 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Comparative Example 5. FIG. 16 is a scatter diagram showing the thickness distribution per layer in the unit constituting the intermediate film obtained in Comparative Example 6. FIG. 17 is a diagram showing the shape of a right-angled test piece used for evaluation of the tear test.

Hereinafter, the present invention will be described in detail.

[Interlayer film for laminated glass]
The interlayer film for laminated glass according to the present invention (hereinafter sometimes abbreviated as an interlayer film) includes a plurality of first thermoplastic resin layers containing a polyvinyl acetal resin and a plasticizer, and a plurality of thermoplastic resins. The second thermoplastic resin layer. In the intermediate film according to the present invention, the absolute value of the difference in intrinsic refractive index between the first thermoplastic resin layer and the second thermoplastic resin layer is 0.1 or more. In the intermediate film according to the present invention, a plurality of the first thermoplastic resin layers and a plurality of the second thermoplastic resin layers are alternately laminated in the thickness direction. Therefore, the intermediate film according to the present invention has a multilayer structure in which a plurality of the first thermoplastic resin layers and a plurality of the second thermoplastic resin layers are alternately stacked in the thickness direction. In the intermediate film according to the present invention, the total number of laminated layers in the thickness direction of the plurality of first thermoplastic resin layers and the plurality of second thermoplastic resin layers is 500 layers or more.

Since the intermediate film according to the present invention has the above-described configuration, the transparency, heat shielding property and toughness of the laminated glass including the intermediate film and the intermediate film can be improved.

The intrinsic refractive indexes of the first thermoplastic resin layer and the second thermoplastic resin layer can be measured by, for example, the following methods.

The material for forming the first thermoplastic resin layer is supplied to a twin-screw extruder, melted and kneaded, introduced into a T die, widened, discharged from an opening, cooled and solidified, A thermoplastic resin sheet having a thickness of 380 μm is obtained. A sheet piece having a width of 10 mm and a length of 30 mm is cut out at the center in the width direction of the thermoplastic resin sheet. Next, using an Abbe refractometer ("ER-7MW" manufactured by ERMA), in accordance with JIS K7142, irradiating D line (wavelength 589.3 nm) at 23 ° C, the refractive index nD of the sheet piece Is measured as the intrinsic refractive index. By the same method, the intrinsic refractive index of the second thermoplastic resin layer is measured.

The absolute value of the difference between the intrinsic refractive index of the first thermoplastic resin layer and the intrinsic refractive index of the second thermoplastic resin layer may be 0.1 or more. The intrinsic refractive index of the first thermoplastic resin layer may be higher than the intrinsic refractive index of the second thermoplastic resin layer. The intrinsic refractive index of the second thermoplastic resin layer may be higher than the intrinsic refractive index of the first thermoplastic resin layer.

¡The greater the absolute value of the difference in intrinsic refractive index, the higher the heat shielding property when the interlayer structure is the same. The absolute value of the difference between the intrinsic refractive index of the first thermoplastic resin layer and the intrinsic refractive index of the second thermoplastic resin layer is preferably 0.11 or more, more preferably 0.12 or more.

Hereinafter, the present invention will be clarified by describing specific embodiments and examples of the present invention with reference to the drawings.

(First embodiment)
In FIG. 1, the intermediate film for laminated glasses which concerns on the 1st Embodiment of this invention is typically shown with a partially notched cross-sectional view.

The interlayer film 1 shown in FIG. 1 is a laminate in which a plurality of first thermoplastic resin layers 21 and a plurality of second thermoplastic resin layers 31 are alternately laminated in the thickness direction. Body 2. In FIG. 1, for convenience of illustration, the total number of layers of the first thermoplastic resin layer 21 and the second thermoplastic resin layer 31 in the thickness direction is about 20, but the first thermoplastic resin layer And the total number of layers in the thickness direction of the second thermoplastic resin layer is actually 500 or more.

The first thermoplastic resin layer 21 and the second thermoplastic resin layer 31 are laminated in the thickness direction of the intermediate film 1 and the laminate 2. The composition of the plurality of first thermoplastic resin layers 21 may be the same or different. The compositions of the plurality of first thermoplastic resin layers 21 are preferably the same. The composition of the plurality of second thermoplastic resin layers 31 may be the same or different. The compositions of the plurality of second thermoplastic resin layers 31 are preferably the same.

When the composition of the first thermoplastic resin layer is different or the composition of the second thermoplastic resin layer is different, the relationship between the intrinsic refractive index and the first thermoplastic resin layer is the same as that of the first thermoplastic resin layer. The minimum absolute value of the difference in intrinsic refractive index with the thermoplastic resin layer 2 may be 0.1 or more.

In the intermediate film 1, the plurality of first thermoplastic resin layers 21 and the plurality of second thermoplastic resin layers 31 are alternately stacked in the thickness direction. The intermediate film 1 has a portion in which the first thermoplastic resin layer 21 is sandwiched between the two second thermoplastic resin layers 31. The intermediate film 1 has a portion in which the second thermoplastic resin layer 31 is sandwiched between the two first thermoplastic resin layers 21. As described above, the first thermoplastic resin layer 21 and the second thermoplastic resin layer 31 have a multilayer structure in which the first thermoplastic resin layer 21 and the second thermoplastic resin layer 31 are alternately laminated in the thickness direction, so that the toughness and the heat shielding property of the intermediate film are increased. .

The intermediate film has a portion in which the first thermoplastic resin layer, the second thermoplastic resin layer, the first thermoplastic resin layer, and the second thermoplastic resin layer are laminated in this order. It is preferable to have a plurality of these portions.

It is not necessary that all of the first thermoplastic resin layer and the second thermoplastic resin layer laminated in total of 500 layers or more are laminated alternately and continuously. If the first thermoplastic resin layer and the second thermoplastic resin layer partially have a multilayer structure in which the first thermoplastic resin layer and the second thermoplastic resin layer are alternately laminated, the toughness and heat shielding property of the intermediate film are increased. For example, two laminates in which 250 layers of first thermoplastic resin layers and second thermoplastic resin layers are alternately and continuously laminated are prepared, and the other layers are arranged between the two laminates. Thus, even when the first thermoplastic resin layer and the second thermoplastic resin layer are laminated in a total of 500 layers in the thickness direction through other layers, the effect of the present invention can be obtained. Included in the invention.

Further, there may be a portion where the first thermoplastic resin layer is continuous, or a portion where the second thermoplastic resin layer is continuous. From the viewpoint of further enhancing the toughness and heat shielding properties of the interlayer film, all of the first thermoplastic resin layers and all of the second thermoplastic resin layers laminated in total of 500 layers or more are continuous in the thickness direction. It is preferable that the layers are alternately laminated.

When all of the first thermoplastic resin layers and all of the second thermoplastic resin layers laminated in total of 500 layers or more are not alternately laminated in the thickness direction, the first thermoplasticity In total, the resin layer and the second thermoplastic resin layer are preferably laminated in a thickness direction of 20 or more layers, more preferably 40 layers or more.

The thickness of the plurality of first thermoplastic resin layers may be the same or different. Further, the thicknesses of the plurality of second thermoplastic resin layers may be the same or different. Furthermore, the thickness of the first thermoplastic resin layer and the second thermoplastic resin layer may be the same or different.

In the intermediate film 1 shown in FIG. 1, the thicknesses of the plurality of first thermoplastic resin layers 21 are different from each other and continuously change in the thickness direction. Similarly, the thicknesses of the plurality of second thermoplastic resin layers 31 are different from each other, and continuously change in the thickness direction. Thus, it is preferable that the 1st thermoplastic resin layer and 2nd thermoplastic resin layer from which thickness differs mutually are laminated | stacked. If the 1st thermoplastic resin layer and 2nd thermoplastic resin layer from which thickness differs mutually are laminated | stacked, the thermal insulation of an intermediate film will become still higher. Since the heat shielding property of the intermediate film is further increased, it is preferable that 20 or more layers of the first thermoplastic resin layer and the second thermoplastic resin layer having different thicknesses are laminated, and 40 or more layers are laminated. More preferably.

In addition, since the heat shielding property of the intermediate film is further enhanced, the intermediate film is a first thermoplastic resin having a thickness different from that of one or two second thermoplastic resin layers in contact with one or both surfaces. Layers and one or two first thermoplastic resin layers in contact with the surface of one or both sides and second thermoplastic resin layers having different thicknesses are alternately laminated in total in the thickness direction by 20 or more layers. It is preferable that the intermediate film has a multilayer structure portion in which a total of 40 layers or more are alternately laminated in the thickness direction.

In this case, if the second thermoplastic resin layer is in contact with only one surface of the first thermoplastic resin layer, “one or two second heats in contact with one or both surfaces. The “first thermoplastic resin layer having a thickness different from that of the thermoplastic resin layer” means “a first thermoplastic resin layer having a thickness different from that of the one second thermoplastic resin layer in contact with the surface on one side”. If the second thermoplastic resin layer is in contact with the surfaces on both sides of the first thermoplastic resin layer, then “one or two second thermoplastic resin layers in contact with one or both surfaces and the thickness. "The first thermoplastic resin layer having a different" means "a first thermoplastic resin layer having a thickness different from that of the two second thermoplastic resin layers in contact with the surfaces on both sides". The same applies to “one or two second thermoplastic resin layers in contact with one or both surfaces”.

When producing a laminated glass using the intermediate film 1, the 1st surface 2a of the laminated body 2 is a surface where a laminated glass member is laminated | stacked, and is the 2nd opposite to the 1st surface 2a of the laminated body 2. The surface 2b is a surface on which laminated glass members are laminated.

(Second Embodiment)
In FIG. 2, the intermediate film for laminated glasses which concerns on the 2nd Embodiment of this invention is typically shown with partial notch sectional drawing.

The intermediate film 12 shown in FIG. 2 has 25 units 11 in the thickness direction in which about 20 layers of the first thermoplastic resin layer 21 and the second thermoplastic resin layer 31 are alternately stacked in the thickness direction in total. It is the laminated body 3 laminated | stacked above. In FIG. 2, for convenience of illustration, about three units 11 are stacked. However, in actuality, 25 or more units 11 are stacked, and as a result, the first thermoplastic resin layer 21 and the second unit 11 are stacked. A total of 500 or more thermoplastic resin layers 31 are laminated in the thickness direction.

The shape of the plurality of units 11 stacked by 25 or more may be the same or different. In the intermediate film 12 shown in FIG. 2, the thicknesses of the plurality of first thermoplastic resin layers 21 and the plurality of second thermoplastic resin layers 31 constituting the unit 11 are in the thickness direction of the intermediate film 12 and the unit 11. It is changing continuously. In addition, there may be units in which the thicknesses of the plurality of first thermoplastic resin layers and the plurality of second thermoplastic resin layers are all the same.

The first thermoplastic resin layer 21 having a thickness different from all of the other first thermoplastic resin layers 21 and all of the second thermoplastic resin layers 31 in the same unit 11 and the first thermoplastic resin layer 21 in the same unit 11 The total number of laminated second thermoplastic resin layers 31 having a thickness different from all of the thermoplastic resin layers 21 and all of the other second thermoplastic resin layers 31 is preferably 20 or more.

When the laminated glass is manufactured using the intermediate film 12, the first surface 3a of the laminated body 3 is a surface on which the laminated glass member is laminated, and is opposite to the first surface 3a of the laminated body 3. The second surface 3b is a surface on which laminated glass members are laminated.

(Third embodiment)
In FIG. 3, the intermediate film for laminated glasses which concerns on the 3rd Embodiment of this invention is typically shown with a partially notched cross-sectional view.

The intermediate film 13 illustrated in FIG. 3 is stacked on the stacked body 2 illustrated in FIG. 1, the third layer 41 stacked on the first surface 2 a of the stacked body 2, and the second surface 2 b of the stacked body 2. And a fourth layer 42. Each of the third layer 41 and the fourth layer 42 is a surface layer. The composition of the third layer 41 and the fourth layer 42 may be the same or different. One third layer 41 may be laminated only on the first surface 2a of the stacked body 2, and the fourth layer 42 may not be laminated on the second surface 2b. The two layers of the third layer 41 and the fourth layer 42 are preferably laminated one by one on the first surface 2a and the second surface 2b of the laminate 2.

An emboss is formed on the outer surface 41a opposite to the laminate 2 side of the third layer 41, although not shown. The outer surface 41a does not necessarily need to be embossed. Although not shown, embossing is formed on the outer surface 42a of the fourth layer 42 opposite to the laminate 2 side. The outer surface 42a does not necessarily have to be embossed.

When the laminated glass is produced using the intermediate film 13, the outer surface 41a of the third layer 41 is a surface on which the laminated glass member is laminated, and the outer surface 42a of the fourth layer 42 is It is the surface where a laminated glass member is laminated.

(Fourth embodiment)
In FIG. 4, the intermediate film for laminated glasses which concerns on the 4th Embodiment of this invention is typically shown with partial notch sectional drawing.

The intermediate film 14 illustrated in FIG. 4 is stacked on the stacked body 3 illustrated in FIG. 2, the third layer 41 stacked on the first surface 3 a of the stacked body 3, and the second surface 3 b of the stacked body 3. And a fourth layer 42. Each of the third layer 41 and the fourth layer 42 is a surface layer. The composition of the third layer 41 and the fourth layer 42 may be the same or different. One third layer 41 may be laminated only on the first surface 3a of the laminate 3, and the fourth layer 42 may not be laminated on the second surface 3b. The two layers of the third layer 41 and the fourth layer 42 are preferably laminated one by one on the first surface 3 a and the second surface 3 b of the laminate 3.

An emboss is formed on the outer surface 41a opposite to the laminate 3 side of the third layer 41, although not shown. The outer surface 41a does not necessarily need to be embossed. Although not shown, embosses are formed on the outer surface 42a of the fourth layer 42 opposite to the laminate 3 side. The outer surface 42a does not necessarily have to be embossed.

When the laminated glass is produced using the intermediate film 14, the outer surface 41a of the third layer 41 is a surface on which the laminated glass member is laminated, and the outer surface 42a of the fourth layer 42 is laminated glass. The surface on which the members are laminated.

As in the third and fourth embodiments, by providing the third layer, and further providing the third layer and the fourth layer, the first thermoplastic resin layer and the second layer are provided. The thickness of the third layer or the fourth layer can be made larger than each thickness of the thermoplastic resin layer, and embossing can be easily formed on the outer surface of the third layer or the fourth layer. However, each thickness of the third layer or the fourth layer may not necessarily be thicker than each thickness of the first thermoplastic resin layer and the second thermoplastic resin layer. Examples of the embossing method include a lip embossing method and a roll embossing method.

Examples of materials for the third layer and the fourth layer include ethylene-vinyl acetate copolymer resin and polyvinyl acetal resin. Since the impact resistance of the laminated glass is further increased, each of the third layer and the fourth layer preferably contains a polyvinyl acetal resin, and more preferably contains a polyvinyl butyral resin.

Hereinafter, other details of the first thermoplastic resin layer and the second thermoplastic resin layer will be described.

(First thermoplastic resin layer)
The first thermoplastic resin layer contains a polyvinyl acetal resin and a plasticizer.

Polyvinyl acetal resin contained in the first thermoplastic resin layer:
In the polyvinyl acetal resin contained in the first thermoplastic resin layer, the absolute value of the difference in intrinsic refractive index between the first thermoplastic resin layer and the second thermoplastic resin layer is 0.1 or more. Is appropriately selected. As for the said polyvinyl acetal resin, only 1 type may be used and 2 or more types may be used together.

The polyvinyl acetal resin is obtained, for example, by acetalizing polyvinyl alcohol (PVA) with an aldehyde. As for the said polyvinyl acetal resin, only 1 type may be used and 2 or more types may be used together.

The PVA can be obtained, for example, by saponifying polyvinyl acetate. The saponification degree of the PVA is generally in the range of 70 to 99.9 mol%. The degree of saponification of the PVA is preferably 80 mol% or more, preferably 99.8 mol% or less.

The average degree of polymerization of the polyvinyl acetal resin is not particularly limited. In consideration of moldability, film formability and expression of various physical properties, the average degree of polymerization of the PVA is preferably 200 or more, more preferably 500 or more, further preferably 1700 or more, preferably 5000 or less, more preferably 3000 or less. More preferably, it is 2500 or less, and particularly preferably 2300 or less. When the average polymerization degree is not less than the above lower limit and not more than the above upper limit, the toughness of the interlayer film is further increased, the penetration resistance and impact energy absorption of the laminated glass are further increased, and the moldability of the interlayer film is increased. The film formability is further enhanced, and the workability of the laminated glass is further enhanced.

The average degree of polymerization of the PVA is determined by a method based on JIS K6726 “Testing method for polyvinyl alcohol”.

The aldehyde is not particularly limited. In general, an aldehyde having 1 to 10 carbon atoms is preferably used as the aldehyde. Examples of the aldehyde having 1 to 10 carbon atoms include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, n-hexylaldehyde, 2-ethylbutyraldehyde, benzaldehyde, and n-octyl. Examples include aldehyde, n-nonyl aldehyde and n-decyl aldehyde. Of these, n-butyraldehyde, n-valeraldehyde or n-hexylaldehyde is preferable, and n-butyraldehyde is more preferable. As for the said aldehyde, only 1 type may be used and 2 or more types may be used together.

The polyvinyl acetal resin may be a copolyvinyl acetal resin in which two or more aldehydes are used in combination at the time of acetalization.

The hydroxyl group content (hydroxyl content) of the polyvinyl acetal resin is preferably 15 mol% or more, more preferably 18 mol% or more, preferably 40 mol% or less, more preferably 35 mol% or less. When the hydroxyl group content is at least the above lower limit, the adhesion of the intermediate film is further enhanced. When the hydroxyl group content is less than or equal to the above upper limit, the flexibility of the intermediate film is increased and the handleability of the intermediate film is improved. Moreover, the intrinsic refractive index of the first thermoplastic resin layer can be increased by increasing the hydroxyl group content of the polyvinyl acetal resin.

The content of hydroxyl groups in the polyvinyl acetal resin is a value obtained by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain, as a percentage (mol%). . The amount of ethylene group to which the hydroxyl group is bonded can be determined, for example, by measuring the amount of ethylene group to which the hydroxyl group of the polyvinyl acetal resin is bonded in accordance with JIS K6728 “Testing method for polyvinyl butyral”. .

The degree of acetylation (acetyl group amount) of the polyvinyl acetal resin is preferably 0.1 mol% or more, more preferably 0.3 mol% or more, still more preferably 0.5 mol% or more, preferably 30 mol% or less. More preferably, it is 25 mol% or less, More preferably, it is 20 mol% or less, Most preferably, it is 10 mol% or less. When the acetylation degree is not less than the above lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer is further enhanced. When the acetylation degree is not more than the above upper limit, the moisture resistance of the intermediate film is further enhanced. Moreover, the intrinsic refractive index of the first thermoplastic resin layer can be lowered by increasing the degree of acetylation of the polyvinyl acetal resin.

The degree of acetylation is obtained by subtracting the amount of ethylene groups to which acetal groups are bonded and the amount of ethylene groups to which hydroxyl groups are bonded from the total amount of ethylene groups of the main chain, This is a value expressed as a percentage (mol%) of the mole fraction obtained by dividing by. The amount of ethylene group to which the acetal group is bonded can be measured, for example, according to JIS K6728 “Testing method for polyvinyl butyral”.

The degree of acetalization of the polyvinyl acetal resin is preferably 40 mol% or more, more preferably 50 mol% or more, still more preferably 60 mol% or more, preferably 85 mol% or less, more preferably 75 mol% or less. When the degree of acetalization is not less than the above lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer is further enhanced. When the degree of acetalization is less than or equal to the above upper limit, the reaction time required for producing a polyvinyl acetal resin is shortened. Further, by increasing the degree of acetalization of the polyvinyl acetal resin, the intrinsic refractive index of the first thermoplastic resin layer can be increased.

The degree of acetalization is a value obtained by dividing a mole fraction obtained by dividing the amount of ethylene groups to which acetal groups are bonded by the total amount of ethylene groups in the main chain, as a percentage (mol%).

The degree of acetalization is determined by measuring the degree of acetylation (acetyl group content) and the hydroxyl group content (vinyl alcohol content) by a method based on JIS K6728 “Testing methods for polyvinyl butyral”. It can be calculated by calculating the fraction and then subtracting the degree of acetylation and the hydroxyl content from 100 mol%.

When the polyvinyl acetal resin is a polyvinyl butyral resin, the degree of acetalization (degree of butyralization) and the degree of acetylation were measured by a method according to JIS K6728 “Testing method for polyvinyl butyral” or ASTM D1396-92. It can be calculated from the result. Measurement by a method based on ASTM D1396-92 is preferred.

The polyvinyl acetal resin is preferably a polyvinyl butyral resin, more preferably a polyvinyl butyral resin obtained by butyralizing PVA with n-butyraldehyde.

Plasticizer contained in the first thermoplastic resin layer:
In the first thermoplastic resin layer, by adding a plasticizer to the polyvinyl acetal resin, the moldability, flexibility and toughness of the intermediate film are increased. Further, when the intrinsic refractive index of the second thermoplastic resin layer is higher than the intrinsic refractive index of the first thermoplastic resin layer, the first thermoplastic resin layer is added by adding a plasticizer to the polyvinyl acetal resin. Therefore, the absolute value of the difference in intrinsic refractive index between the first thermoplastic resin layer and the second thermoplastic resin layer can be further increased, and the transparency and shielding of the intermediate film can be increased. Thermal property can be further enhanced. In order to obtain this effect, the first thermoplastic resin layer contains a plasticizer and the second thermoplastic resin layer does not contain a plasticizer, or the first thermoplastic resin layer and the second heat Each of the plastic resin layers contains a plasticizer, and the content of the plasticizer with respect to 100 parts by mass of the polyvinyl acetal resin contained in the first thermoplastic resin layer is 100 masses of the thermoplastic resin contained in the second thermoplastic resin layer. It is preferable that the content of the plasticizer is larger than that of the part.

Since the plurality of first thermoplastic resin layers are alternately stacked with the plurality of second thermoplastic resin layers, the plasticizer preferably has a low molecular weight. If the plasticizer has a relatively low molecular weight, the migration of the plasticizer from the first thermoplastic resin layer to the second thermoplastic resin layer can be suppressed, and the plasticizer hardly migrates to the surface of the intermediate film. . For this reason, bleed-out is suppressed by using a plasticizer having a relatively low molecular weight. As a result, the plasticizer hardly reduces the adhesive force between the laminated glass member and the intermediate film, and the transparency of the intermediate film is further enhanced.

A conventionally known plasticizer can be used as the plasticizer. As for the said plasticizer, only 1 type may be used and 2 or more types may be used together.

Examples of the plasticizer include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, and phosphate plasticizers such as organic phosphate plasticizers and organic phosphorous acid plasticizers. It is done. Of these, organic ester plasticizers are preferred. The plasticizer is preferably a liquid plasticizer.

The monobasic organic acid ester is not particularly limited. For example, a glycol ester obtained by reaction of glycol with a monobasic organic acid, and triethylene glycol or tripropylene glycol with a monobasic organic acid. Examples include esters. Examples of the glycol include triethylene glycol, tetraethylene glycol, and tripropylene glycol. Examples of the monobasic organic acid include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, n-octylic acid, 2-ethylhexylic acid, n-nonylic acid, and decylic acid.

The polybasic organic acid ester is not particularly limited, and examples thereof include an ester compound of a polybasic organic acid and an alcohol having a linear or branched structure having 4 to 8 carbon atoms. Examples of the polybasic organic acid include adipic acid, sebacic acid, and azelaic acid.

The organic ester plasticizer is not particularly limited, and triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n- Octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethyl butyrate, 1,3-propylene glycol di -2-Ethyl butyrate, 1,4-butylene glycol di-2-ethyl butyrate, diethylene glycol di-2-ethyl butyrate, diethylene glycol di-2-ethyl hexanoate, dipropylene glycol Rudi-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, adipine Examples include a mixture of heptyl acid and nonyl adipate, diisononyl adipate, diisodecyl adipate, heptylnonyl adipate, dibutyl sebacate, alkyd oil-modified sebacic acid, and a mixture of phosphate ester and adipate. Organic ester plasticizers other than these may be used. Other adipic acid esters other than the above-mentioned adipic acid esters may be used.

The organic phosphate plasticizer is not particularly limited, and examples thereof include tributoxyethyl phosphate, isodecylphenyl phosphate, triisopropyl phosphate, and the like.

The plasticizer preferably contains a diester plasticizer represented by the following formula (1). By using this diester plasticizer, the sound insulation of the laminated glass is further enhanced.

In the above formula (1), R1 and R2 each represents an organic group having 5 to 10 carbon atoms, R3 represents an ethylene group, an isopropylene group or an n-propylene group, and p represents an integer of 3 to 10 . R1 and R2 in the above formula (1) are each preferably an organic group having 6 to 10 carbon atoms.

The plasticizer preferably contains at least one of triethylene glycol di-2-ethylhexanoate (3GO) and triethylene glycol di-2-ethylbutyrate (3GH). More preferably, it contains 2-ethylhexanoate.

The content of the plasticizer contained in the first thermoplastic resin layer is preferably 20 parts by mass or more, more preferably, with respect to 100 parts by mass of the polyvinyl acetal resin contained in the first thermoplastic resin layer. 25 parts by mass or more, more preferably 30 parts by mass or more, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 60 parts by mass or less, and particularly preferably 55 parts by mass or less. When the content of the plasticizer is not less than the above lower limit, the plasticizing effect of the polyvinyl acetal resin is further increased, the moldability of the interlayer film is further increased, and the penetration resistance of the laminated glass is further increased. When the content of the plasticizer is not more than the above upper limit, the plasticizer bleed-out hardly occurs and the transparency of the intermediate film is further enhanced.

It is preferable that the second thermoplastic resin layer does not contain a plasticizer. However, the second thermoplastic resin layer may contain a plasticizer. The content of the plasticizer contained in the second thermoplastic resin layer is preferably less than 30 parts by mass with respect to 100 parts by mass of the thermoplastic resin contained in the second thermoplastic resin layer, more preferably Less than 25 parts by weight, more preferably less than 20 parts by weight, still more preferably less than 15 parts by weight, particularly preferably less than 10 parts by weight, and most preferably less than 5 parts by weight.

(Second thermoplastic resin layer)
The second thermoplastic resin layer contains a thermoplastic resin.

Thermoplastic resin contained in the second thermoplastic resin layer:
In the thermoplastic resin contained in the second thermoplastic resin layer, the absolute value of the difference in intrinsic refractive index between the first thermoplastic resin layer and the second thermoplastic resin layer is 0.1 or more. Is appropriately selected. As for the said thermoplastic resin, only 1 type may be used and 2 or more types may be used together.

The thermoplastic resin contained in the second thermoplastic resin layer when the intrinsic refractive index of the first thermoplastic resin layer is 0.1 or more higher than the intrinsic refractive index of the second thermoplastic resin layer Is preferably a thermoplastic resin having an intrinsic refractive index lower than the intrinsic refractive index of the polyvinyl acetal resin contained in the first thermoplastic resin layer. Examples of the thermoplastic resin having an intrinsic refractive index lower than the intrinsic refractive index of the polyvinyl acetal resin included in the first thermoplastic resin layer include a fluororesin. Examples of the fluororesin include polytetrafluoroethylene.

The thermoplastic resin contained in the second thermoplastic resin layer when the intrinsic refractive index of the second thermoplastic resin layer is 0.1 or more higher than the intrinsic refractive index of the first thermoplastic resin layer Is preferably a thermoplastic resin having an intrinsic refractive index higher than that of the polyvinyl acetal resin contained in the first thermoplastic resin layer. Examples of the thermoplastic resin having an intrinsic refractive index higher than the intrinsic refractive index of the polyvinyl acetal resin contained in the first thermoplastic resin layer include polyester resins, polycarbonate resins, polyamide resins, polyurethane resins, acrylic resins, and polystyrene resins. Polypropylene resin, acetyl cellulose resin, polyvinyl chloride resin, cyclic olefin resin, styrene-butadiene copolymer resin, and the like. Since the intrinsic refractive index is relatively high, polystyrene resin, polyester resin, polycarbonate resin or styrene-butadiene copolymer resin is preferable, and polystyrene resin, polyester resin or polycarbonate resin is more preferable.

(Other ingredients)
The first thermoplastic resin layer, the second thermoplastic resin layer, the third layer, and the fourth layer are respectively an antioxidant (anti-aging agent), a thermal stabilizer, if necessary. You may contain various additives, such as a light stabilizer, a ultraviolet absorber, an adhesive force regulator, a moisture-proof agent, a lubricant, a coloring agent, a heat ray reflective agent, a heat ray absorber, an antistatic agent, and a flame retardant. As for the said additive, only 1 type may be used and 2 or more types may be used together.

(Other details of interlayer film)
The manufacturing method of the said intermediate film is not specifically limited, A conventionally well-known method can be used. For example, a material for forming a thermoplastic resin layer is supplied to an extruder, melted and kneaded, extruded from a mold attached to the tip of the extruder into a film, and then subjected to an electrostatic printing cast method, a touch roll It is possible to use a melt extrusion method in which a film is cooled and solidified on a cooling roll and formed into a long film by an air knife casting method. In addition, after casting a solution in which the material for forming the thermoplastic resin layer is dissolved in an organic solvent onto a drum or an endless belt, the organic solvent is evaporated to obtain a long film. A forming method such as a solution casting method for forming a film can be used. The melt extrusion method is preferred because it is easy to manufacture and has low manufacturing costs.

The method for producing the intermediate film is a method for producing an intermediate film in which a plurality of the first thermoplastic resins and a plurality of the second thermoplastic resin layers are laminated in the thickness direction, and the thermoplastic resin is melted. A first step of melt-kneading by an extrusion method, extending the lamination, forming into a film shape, and obtaining a molten resin laminate (hereinafter sometimes abbreviated as a resin laminate), and the molten resin laminate And a second step of obtaining an intermediate film by discharging from the die opening and cooling with a cooling roll.

The first step is a step of obtaining a molten resin laminate by melt-kneading a thermoplastic resin by a melt-extrusion method and then laminating and then expanding, or forming and forming a film by laminating after expansion. It is.

Regarding the melt extrusion method, the T-die molding method is preferable because the die lip opening must be formed in an elongated shape in order to form a film. In the T-die molding method, the T die is provided with a resin inflow portion and a manifold. The manifold is longer in the width direction than the resin inflow portion, and has a structure connected to the resin inflow portion. The resin supplied from the resin inflow portion flows so as to expand in the width direction within the manifold, and is then transported to the lip land at the die opening.

Examples of the melt extrusion method include a melt extrusion method in which a material for forming a thermoplastic resin layer is formed into a film and laminated to form a resin laminate. Examples of the melt extrusion method include a co-extrusion method. The co-extrusion method is a method in which a plurality of materials are extruded from individual molding machines in a molten state, introduced into a mold, and laminated in a molten state inside and outside the mold. The co-extrusion method is roughly classified into several types such as a feed block method, a multi-manifold method, a multi-slot die method, and a static mixer method, depending on the timing at which the extruded materials are laminated and the forming accuracy. From the viewpoint of laminating many thermoplastic resin layers with high accuracy, the above feed block method is preferable.

In the above feed block method, two or more kinds of materials are laminated in the resin inflow part, supplied to the flat die manifold, and expanded in the width direction while maintaining the laminated state in the manifold, and laminated from the die lip opening. This is a method of discharging. In the above feed block method, there is no need to provide a manifold for each thermoplastic resin layer to be laminated, so the flat die structure can be simplified compared to other methods, and therefore the operability and maintainability are improved. Excellent.

The feed block mainly has a plurality of upstream flow paths, a merging portion, and a downstream flow path. A plurality of materials flowing from the upstream flow path are divided by introducing the material (resin) into the plurality of flow paths at the junction in the feed block, and the divided materials are alternately stacked. Next, the flow paths are alternately arranged and merged in a laminated state in the thickness direction, and the merged laminated body is flowed from the downstream flow path to the downstream flow path adapter, flat die or the like to form a laminated structure. .

The thickness of all of the plurality of first thermoplastic resin layers included in the intermediate film is preferably 700 nm or less, more preferably 50 nm or more and 700 nm or less. Furthermore, the thickness of all the second thermoplastic resin layers included in the intermediate film is preferably 700 nm or less, more preferably 50 nm or more and 700 nm or less. When the thickness per layer of all of the first thermoplastic resin layer and the second thermoplastic resin layer is 700 nm or less, or 50 nm or more and 700 nm or less, a multilayer structure existing in the intermediate film Thus, visible light and infrared light can be selectively reflected or transmitted according to the wavelength, and an intermediate film that is more excellent in transparency and heat shielding properties can be obtained. The thickness per layer of the plurality of first thermoplastic resin layers contained in the intermediate film is more preferably 90 nm or more, and more preferably 350 nm or less. Furthermore, the thickness per layer of the second thermoplastic resin layers contained in the intermediate film is more preferably 90 nm or more, and more preferably 350 nm or less.

In the intermediate film, the thickness per layer of all the plurality of first thermoplastic resin layers is 700 nm or less, or 50 nm or more and 700 nm or less, and all one layer of the plurality of second thermoplastic resin layers More preferably, the total thickness of the first thermoplastic resin layer and the second thermoplastic resin layer having a per-thickness of 700 nm or less or 50 nm or more and 700 nm or less and different from each other is 20 or more. Furthermore, the thickness per layer of all of the plurality of first thermoplastic resin layers is 700 nm or less, or 50 nm or more and 700 nm or less, and the thickness per layer of all of the plurality of second thermoplastic resin layers. 700 nm or less or 50 nm or more and 700 nm or less, and one or two second thermoplastic resin layers that are in contact with the surface of one side or both sides and a first thermoplastic resin layer having a different thickness, Multi-layer structure portion in which one or two first thermoplastic resin layers in contact with the surfaces on both sides and second thermoplastic resin layers having different thicknesses are alternately stacked in a thickness direction in total of 20 layers or more It is preferable to contain. In these preferable intermediate films, since the thicknesses of the first thermoplastic resin layer and the second thermoplastic resin layer constituting the intermediate film are different from each other, reflection characteristics with respect to a wide range of light wavelengths are exhibited, and in particular, infrared light is transmitted over a wide band. It is possible to reflect with respect to the wavelength, and an intermediate film that is more excellent in transparency and heat shielding properties can be obtained.

In order to make the thicknesses of the first thermoplastic resin layer and the second thermoplastic resin layer different from each other, there may be 20 or more resin flow paths in the merging portion in the feed block, and the widths of the resin flow paths may be different from each other. preferable. In addition, the ratio of the channel width corresponds to the thickness ratio of the layers in the obtained intermediate film. Therefore, the channel width is appropriately set according to the desired layer thickness and optical characteristics.

The method of setting the number of laminated layers of the molten resin laminate to 500 or more is not particularly limited, and examples thereof include a method using a multilayer block. As the multi-layer block, the resin laminate obtained by joining in the feed block is in a direction perpendicular to the surface of the resin laminate and parallel to the flow direction of the resin laminate during production, By stacking the divided resin laminate again in the thickness direction and repeating this, a flow path block capable of obtaining a resin laminate having more layers can be used.

When using the above coextrusion method, the composition of the material forming the thermoplastic resin layer, the type of thermoplastic resin contained in the material, the thickness and film width of the target layer, the molding environment and operability, etc. The equipment specifications, methods and conditions can be selected as appropriate.

When the thermoplastic resin is an amorphous thermoplastic resin, the glass transition temperature of the amorphous thermoplastic resin is defined as Tg. In the step (1), the temperature at which the material for forming the thermoplastic resin layer is melt-kneaded is preferably (Tg + 50) or higher, preferably (Tg + 200) ° C. or lower. By melt-kneading at the above temperature, the resin fluidity at the time of extrusion molding is improved, and an intermediate film excellent in dimensional accuracy such as thickness and length can be obtained.

Tg is a glass transition temperature at the time of final temperature rise measured under the following temperature program conditions using a differential scanning calorimeter (“DSC2920 Modulated DSC” manufactured by TA Instruments).

Temperature program conditions:
The temperature is raised from room temperature (23 ° C.) to 50 ° C. at a rate of 10 ° C./min and held at 50 ° C. for 5 minutes. The temperature is raised from 50 ° C. to 200 ° C. at 10 ° C./min and held at 200 ° C. for 5 minutes. The temperature is lowered from 200 ° C. to −50 ° C. at a rate of 10 ° C./min, and held at −50 ° C. for 5 minutes. The temperature is raised from −50 ° C. to 200 ° C. at a rate of 10 ° C./min and held at 200 ° C. for 5 minutes.

The molten resin laminate is formed by the first step described above.

The first step is a step of discharging the molten resin laminate from a die opening and cooling it with a cooling roll to obtain an intermediate film. Although it does not specifically limit as a method of cooling the said molten resin laminated body with the said cooling roll, The electrostatic printing cast method, the touch roll method, and the air knife cast method are mentioned. In the second step, the resin laminate is cooled and solidified on a cooling roll and formed into a long intermediate film.

In the second step, the molten resin laminate is rapidly cooled to form an intermediate film and to obtain a substantially non-oriented intermediate film. When the said thermoplastic resin is an amorphous thermoplastic resin, let the glass transition temperature of an amorphous thermoplastic resin be Tg. The surface temperature of the cooling roll is preferably (Tg−150) ° C. or higher, preferably (Tg) ° C. or lower.

The intermediate film is formed by the second step described above.

The total number of laminated layers in the thickness direction of the first thermoplastic resin layer and the second thermoplastic resin layer of the intermediate film is 500 layers or more. When the number of laminated layers is 500 layers or more, the number of layer interfaces contributing to infrared reflection increases, so that the infrared reflectivity of the laminated glass is further increased, and the intermediate between the thermal barrier and transparency is more excellent. A membrane is obtained. From the viewpoint of expressing these performances more favorably, the total number of laminated layers in the thickness direction of the first thermoplastic resin layer and the second thermoplastic resin layer is preferably 550 layers or more, more preferably There are 650 layers or more.

The thickness of the intermediate film is not particularly limited. The thickness of the intermediate film correlates with the penetration resistance of the laminated glass. Usually, the thicker the interlayer film, the higher the penetration resistance of the laminated glass. Therefore, in consideration of the minimum necessary impact resistance, penetration resistance, transparency and economy of laminated glass, the thickness of the interlayer film is practically preferably 0.05 mm or more, preferably 3 mm or less. From the viewpoint of further improving the penetration resistance of the laminated glass, the thickness of the intermediate film is more preferably 0.1 mm or more, further preferably 0.25 mm or more, preferably 1.5 mm or less, more preferably 1.0 mm or less. It is.

The incident light reflectance of the intermediate film is preferably 20% or less, more preferably 10% or less, at an incident wavelength of 350 to 800 nm. The incident light reflectance of the intermediate film is preferably 50% or more, more preferably 80% or more at an incident wavelength of 800 to 2500 nm. When the reflectance of incident light satisfies the above-mentioned preferable values, the infrared reflectance and visible light transmittance of the laminated glass are further improved, and an intermediate film that is more excellent in heat shielding properties and transparency can be obtained. The method for measuring the reflectance of the incident light is not particularly limited, but is preferably measured according to the following procedure. After polishing the surface of the resulting multilayer film with # 400 sandpaper, a black paint is applied to obtain a measurement piece. Using “U-4100” manufactured by Hitachi High-Technology Co., Ltd., light having a wavelength of 350-2500 nm is incident at an incident angle of 5 ° from the non-polished surface of the measurement piece under the conditions of a temperature of 23 ° C. and a humidity of 50%. The reflectance is measured at 1 nm pitch. The average value of the measurement data at a wavelength of 350 to 800 nm calculated from the obtained reflectance data is defined as the reflectance.

The tear energy of the interlayer film at 23 ° C. is preferably 0.05 J / mm ² or more. When the tear energy is equal to or higher than the lower limit, the impact resistance and penetration resistance of the laminated glass are further increased, and the laminated glass can be more suitably used for vehicle use and construction use.

[Laminated glass]
The interlayer film for laminated glass according to the present invention is used for obtaining laminated glass.

FIG. 5 schematically shows an example of a laminated glass using the intermediate film 1 shown in FIG.

A laminated glass 15 shown in FIG. 5 includes a first laminated glass member 51, a second laminated glass member 52, and the intermediate film 1. The interlayer film 1 is disposed between the first laminated glass member 51 and the second laminated glass member 52 and is sandwiched.

The first laminated glass member 51 is laminated on the first surface 2a of the laminate 2 that is the intermediate film 1. The second laminated glass member 52 is laminated on the second surface 2 b of the laminate 2 that is the intermediate film 1. Therefore, the laminated glass 15 is configured by laminating the first laminated glass member 51, the laminated body 2 as the intermediate film 1, and the second laminated glass member 52 in this order.

FIG. 6 schematically shows an example of a laminated glass using the intermediate film 13 shown in FIG. 3 in a partially cutaway sectional view.

6 includes a first laminated glass member 51, a second laminated glass member 52, and an intermediate film 13. The intermediate film 13 includes a third layer 41, the stacked body 2, and a fourth layer 42. The intermediate film 13 is disposed between the first laminated glass member 51 and the second laminated glass member 52 and is sandwiched.

The first laminated glass member 51 is laminated on the outer surface 41 a of the third layer 41. The second laminated glass member 52 is laminated on the outer surface 42 a of the fourth layer 42. Therefore, the laminated glass 16 includes the first laminated glass member 51, the third layer 41, the laminated body 2, the fourth layer 42, and the second laminated glass member 52 laminated in this order. It is configured.

Examples of the laminated glass member include a glass plate and a PET (polyethylene terephthalate) film. The laminated glass includes not only laminated glass in which an intermediate film is disposed between two glass plates, but also laminated glass in which an intermediate film is disposed between a glass plate and a PET film or the like. The laminated glass is a laminate including a glass plate, and preferably at least one glass plate is used. Each of the first laminated glass member and the second laminated glass member is preferably a glass plate or a PET film, and the laminated glass is glass as at least one of the first laminated glass member and the second laminated glass member. It is preferable to provide a plate.

The glass plate may be an inorganic glass plate or an organic glass plate. Specific examples of the glass plate include, but are not limited to, inorganic glass such as float plate glass, polished plate glass, flat plate glass, curved plate glass, parallel plate glass, template plate glass, wire mesh type plate glass, and colored glass, polycarbonate resin and poly Examples thereof include organic glass formed of methyl methacrylate resin.

As the method for producing the laminated glass, the same production method as that for ordinary laminated glass can be employed. For example, in order to obtain the laminated glass, preliminary press bonding and main press bonding are performed. For example, pre-compression is performed by pre-crimping a laminate with an interlayer film sandwiched between two laminated glass members through a nip roll and degassing under conditions of a temperature of about 50 to 100 ° C. and a pressure of about 0.2 to 1 MPa. And a laminated body in which an interlayer film is sandwiched between two laminated glass members are placed in a rubber bag, the rubber bag is connected to an exhaust system, and the temperature is about 60 to 100 ° C. It is carried out by a pre-pressure bonding method (vacuum degassing method) under a pressure of about 1 to 50 Pa. Next, the pre-pressed laminate is subjected to main press bonding under the conditions of a temperature of about 120 to 170 ° C. and a pressure of about 0.2 to 15 MPa using an autoclave or a press according to a conventional method. Is obtained.

The laminated glass can be suitably used for, for example, an automobile windshield, side glass, rear glass, a glass part of a vehicle such as an aircraft or a train, a glass part of a building, and the like. The laminated glass can also be used as a functional laminated glass such as a sound insulating laminated glass having a sound insulating property by being laminated with another inorganic film or an organic film. Furthermore, the intermediate film can also be used as a damping material by laminating with a rigid body other than glass, for example, a metal or an inorganic material.

The haze value of the laminated glass is preferably 3% or less, more preferably 2% or less, even more preferably 1% or less, still more preferably 0.5% or less, and particularly preferably 0.4% or less. The haze value of the laminated glass can be measured according to JIS K7316.

Hereinafter, the present invention will be specifically described with reference to examples and comparative examples. The present invention is not limited only to the following examples.

Example 1
100 parts by mass of polyvinyl butyral resin (average polymerization degree 1700, hydroxyl group content 30.3 mol%, acetylation degree 0.7 mol%, butyralization degree 69 mol%) and triethylene glycol di-diene which is a plasticizer 40 parts by mass of 2-ethylhesanoate and an amount of magnesium to be 50 ppm in an intermediate film capable of obtaining a mixture having a mass ratio of 1: 1 of magnesium acetate / 2-ethylbutyrate, which is an adhesion modifier, It supplied to the twin-screw type extruder I, and melt-kneaded, and the material (intrinsic refractive index = 1.4809) for forming a 1st thermoplastic resin layer was obtained.

At the same time, a polyethylene terephthalate resin (polyester resin, relative viscosity 1.38, intrinsic refractive index = 1.6052) is twin screw extruder II (cylinder diameter D = 30 mm, L / D) attached to the twin screw extruder I = 45) and melt-kneaded to obtain a material for forming the second thermoplastic resin layer.

The material for forming the first thermoplastic resin layer and the material for forming the second thermoplastic resin layer are each described as a 21-layer feed block (hereinafter referred to as “FB”) via a feed pipe. The resin laminate was obtained by joining them in the FB.

The merged first thermoplastic resin layer has 11 layers, the merged second thermoplastic resin layer has 10 layers, and the first thermoplastic resin layer 11 and the second thermoplastic resin layer A total of 21 layers of 10 thermoplastic resin layers were alternately laminated in the thickness direction to prepare a resin laminate.

Further, a total of 5 sets of multi-layer blocks that can be divided into two layers can be attached to the downstream part of the FB, and the total number of layers is obtained by laminating 32 resin laminates (21 layers) in the thickness direction. 672 layers were introduced into a T-die and widened, and discharged from a die lip opening to obtain a molten resin laminate. The T die was provided with a straight manifold, the die lip opening was rectangular, the longitudinal width was 1500 mm, and the width in the direction perpendicular to the longitudinal direction was 2.5 mm.

The molten resin laminate is melt-extruded at a take-up speed of 10 m / min onto a cooling roll that is chrome-plated and temperature-adjusted to 20 ° C. from the die lip opening of the T die, and is cooled and solidified to be continuously in a sheet form. A film was formed. In the slit process, the film end was removed by slitting with a shear blade installed symmetrically from the film center. The intermediate film was wound in the form of a roll on a vinyl chloride resin core with a winding tension of 70 N / m width. In this way, an intermediate film having an average thickness in the width direction of 147 μm was produced.

The obtained intermediate film has the flow path shape and the resin extrusion amount in the FB so that the thicknesses of the first thermoplastic resin layer and the second thermoplastic resin layer become the thickness shown in FIG. Thirty-two units obtained by adjustment are stacked in the thickness direction.

(Example 2)
Polyvinyl butyral resin used as a material for forming the first thermoplastic resin layer is polyvinyl butyral resin (average polymerization degree 2300, hydroxyl group content 24 mol%, acetylation degree 15 mol%, butyralization degree 61 mol%). The intermediate film was obtained in the same manner as in Example 1 except that the intrinsic refractive index of the material for forming the first thermoplastic resin layer was changed to 1.4759.

Example 3
The number of joined first thermoplastic resin layers is 21, the number of joined second thermoplastic resin layers is 20, and the first thermoplastic resin layer 21 and the second thermoplastic resin layer A total of 41 layers of 20 thermoplastic resin layers were alternately laminated in the thickness direction, and a total of 4 sets of multilayer blocks were attached, and 16 resin laminates (41 layers) were laminated in the thickness direction. An intermediate film having an average thickness in the width direction of 175 μm was obtained in the same manner as in Example 1 except that the total number was changed to 656 layers.

The obtained intermediate film has the flow path shape and the resin extrusion amount in the FB so that the thicknesses of the first thermoplastic resin layer and the second thermoplastic resin layer become the thickness shown in FIG. Sixteen units obtained by adjustment are stacked in the thickness direction.

Example 4
The merged first thermoplastic resin layer has 18 layers, the merged second thermoplastic resin layer has 17 layers, and the first thermoplastic resin layer 18 and the second thermoplastic resin layer A total of 35 layers of 17 thermoplastic resin layers were alternately laminated in the thickness direction, and a total of 4 sets of multi-layer blocks were attached, and 16 resin laminates (35 layers) were laminated in the thickness direction. An intermediate film having an average thickness in the width direction of 187 μm was obtained in the same manner as in Example 1 except that the total number was changed to 560 layers.

(Example 5)
Example 1 except that the polyethylene terephthalate resin used for the material for forming the second thermoplastic resin layer was changed to a polycarbonate resin (“Panlite 1225L” manufactured by Teijin Chemicals Ltd., intrinsic refractive index = 1.951). In the same manner, an interlayer film was obtained.

The obtained intermediate film has the flow path shape and the resin extrusion amount in the FB so that the thicknesses of the first thermoplastic resin layer and the second thermoplastic resin layer are as shown in FIG. Thirty-two units obtained by adjustment are stacked in the thickness direction.

(Example 6)
By changing the content of the plasticizer used for the material for forming the first thermoplastic resin layer from 40 parts by mass to 25 parts by mass, the intrinsic refractive index of the material for forming the first thermoplastic resin layer An intermediate film was obtained in the same manner as in Example 1 except that was changed to 1.4715.

The obtained intermediate film has a flow path shape and resin extrusion in the FB so that the thicknesses of the first thermoplastic resin layer and the second thermoplastic resin layer are the same as those shown in FIG. 32 units obtained by adjusting the amount are stacked in the thickness direction.

(Example 7)
By changing the content of the plasticizer used for the material for forming the first thermoplastic resin layer from 40 parts by mass to 55 parts by mass, the intrinsic refractive index of the material for forming the first thermoplastic resin layer Was changed to 1.4953 in the same manner as in Example 1 to obtain an interlayer film.

(Example 8)
Polyvinyl butyral resin used as a material for forming the first thermoplastic resin layer is polyvinyl butyral resin (average polymerization degree 2000, hydroxyl group content 35.4 mol%, acetylation degree 0.6 mol%, butyralization) The intermediate film was obtained in the same manner as in Example 1, except that the intrinsic refractive index of the material for forming the first thermoplastic resin layer was changed to 1.4755. .

Example 9
Polyvinyl butyral resin used as a material for forming the first thermoplastic resin layer is polyvinyl butyral resin (average polymerization degree 2400, hydroxyl group content 36 mol%, acetylation degree 2 mol%, butyralization degree 62 mol%). The intermediate film was obtained in the same manner as in Example 1 except that the intrinsic refractive index of the material for forming the first thermoplastic resin layer was changed to 1.4874.

(Example 10)
Example 1 except that the polyethylene terephthalate resin used as the material for forming the second thermoplastic resin layer was changed to a polystyrene resin (“Toyostyrene HRM26” manufactured by Toyo Styrene Co., Ltd., intrinsic refractive index = 1.5980). In the same manner, an interlayer film was obtained.

(Example 11)
The polyethylene terephthalate resin used as the material for forming the second thermoplastic resin layer was changed to a styrene-butadiene copolymer resin (“Clurelen 530L” manufactured by Denki Kagaku Kogyo Co., Ltd., intrinsic refractive index = 1.5847). Except for this, an interlayer film was obtained in the same manner as in Example 1.

(Comparative Example 1)
An intermediate having an average thickness in the width direction of 155 μm in the same manner as in Example 1 except that the extruder II, FB and the multilayer block were not used and only the extruder I was used to obtain a single-layer intermediate film. A membrane was prepared.

(Comparative Example 2)
The material for forming the first thermoplastic resin layer is changed to 1.4692 by changing the intrinsic refractive index of the material for forming the first thermoplastic resin layer to 1.4692 without using a plasticizer. In the same manner as in Example 1, an interlayer film was obtained. As a result, the absolute value of the difference in refractive index between the first thermoplastic resin layer and the second thermoplastic resin layer was less than 0.1.

(Comparative Example 3)
A total of 3 sets of multilayer blocks were attached, and the width of the resin laminate (21 layers) was laminated in the thickness direction by laminating 8 pieces in the thickness direction to change the total number of layers to 168 layers. An intermediate film having an average thickness in the direction of 154 μm was obtained.

The obtained intermediate film has the flow path shape and the resin extrusion amount in the FB so that the thicknesses of the first thermoplastic resin layer and the second thermoplastic resin layer become the thickness shown in FIG. Eight units obtained by adjustment are stacked in the thickness direction.

(Comparative Example 4)
A total of 3 sets of multilayer blocks were attached, and the width of the resin laminate (41 layers) was changed to 328 layers by laminating 8 resin laminates (41 layers) in the thickness direction. An intermediate film having an average thickness in the direction of 368 μm was obtained.

(Comparative Example 5)
A polyethylene terephthalate resin used as a material for forming the second thermoplastic resin layer is an ethylene-vinyl acetate copolymer resin (Evaflex, EV560 manufactured by Mitsui DuPont Polychemical Co., Ltd., intrinsic refractive index = 1.4959). The intermediate film was obtained in the same manner as in Example 1 except that it was changed to (1).

(Comparative Example 6)
Except for changing the polyethylene terephthalate resin used as a material for forming the second thermoplastic resin layer to a polymethyl methacrylate resin (“Parapet HR-L, intrinsic refractive index = 1.4902” manufactured by Kuraray Co., Ltd.) An intermediate film was obtained in the same manner as in Example 1.

(Evaluation)
Intrinsic refractive index of the first thermoplastic resin layer, intrinsic refractive index of the second thermoplastic resin layer, thickness of the first thermoplastic resin layer in the unit, thickness of the second thermoplastic resin layer in the unit, Evaluation methods of haze value, reflectance, and tear energy are as follows.

(1) Intrinsic Refractive Index A material for forming the first thermoplastic resin layer is supplied to a twin screw extruder, melted and kneaded, introduced into a T die, widened, and discharged from an opening. It was melt-extruded at a take-up speed of 10 m / min on a cooling roll that had been chrome-plated and the temperature was adjusted to 20 ° C., and was cooled and solidified to obtain a 380 μm thick sheet-like thermoplastic resin sheet. A sheet piece having a width of 10 mm and a length of 30 mm was cut out from the central portion in the width direction of the obtained thermoplastic resin sheet. Using an Abbe refractometer (ERMA "ER-7MW"), the refractive index nD of the sheet piece is measured by irradiating the D-line (wavelength 589.3 nm) at 23 ° C in accordance with JIS K7142. The intrinsic refractive index of the first thermoplastic resin layer was used. Further, the intrinsic refractive index of the second thermoplastic resin layer was measured by the same method.

(2) Number of laminated intermediate films and thickness per layer per unit The central portion in the width direction of the intermediate film was cut parallel to the longitudinal direction with a microtome to expose the cross section of the intermediate film. The cross section was observed using a scanning electron microscope (SEM) (“S-4800” manufactured by Hitachi, Ltd.) or a digital microscope (“VHX-200” manufactured by Keyence Co., Ltd.). An enlarged image of the center of the direction was obtained.

From the obtained image, the number of all layers (number of layers) existing in the cross section was evaluated.

In addition, an arbitrary unit is selected from the obtained images, the thicknesses of all the layers in the unit are measured using the measurement function attached to the SEM or the digital microscope, and the obtained measurement values are scattered. Plotted according to the stacking order in the unit on the figure, the thickness distribution in the unit (FIGS. 7 to 16), and the maximum and minimum layer thicknesses in the unit are shown in Table 1 below. In the cross-sectional observation and image photographing, the SEM was used in Examples 1 to 11 and Comparative Examples 2 and 4 to 6, and the microscope was used in Comparative Examples 1 and 3.

(3) Haze value The obtained interlayer film was cut into a length of 30 mm and a width of 320 mm. Next, an interlayer film is sandwiched between two transparent float glasses (length 25 mm × width 305 mm × thickness 2.0 mm), held at 90 ° C. for 30 minutes with a vacuum laminator, and vacuum pressed to obtain a laminate. It was. In the laminated body, the intermediate film portion protruding from the glass was cut off to obtain a laminated glass.

Using a haze meter (“TC-HIII PDK” manufactured by Tokyo Denshoku), the haze value of the obtained laminated glass was measured according to JIS K7136.

(4) Reflectivity The surface of the obtained intermediate film was polished with # 400 sandpaper, and then a black paint was applied to obtain a measurement piece. Using “U-4100” manufactured by Hitachi High-Technology Co., Ltd., light having a wavelength of 350-2500 nm is incident at an incident angle of 5 ° from the non-polished surface of the measurement piece under the conditions of temperature 23 ° C. and humidity 50% The reflectance was measured at a pitch of 1 nm. The average value of the measurement data at a wavelength of 350 to 800 nm and the average value of the measurement data at a wavelength of 800 to 2500 nm calculated from the obtained reflectance data were taken as the reflectance.

(5) Tear energy Using a dumbbell cutter, the interlayer films for laminated glass obtained in Examples 1 to 11 and Comparative Examples 1 to 6 were cut out to prepare right-angle test pieces having the shape shown in FIG. In accordance with the method specified in JIS K 7128, a tear test of the above test piece was performed using “Tensilon RTG-1310” manufactured by A & D, and measurement was performed at 23 ° C. and a tensile speed of 500 mm / min. The tear energy was calculated from the tear force-strain curve.

Details and results are shown in Table 1 below. In Table 1 below, “PVB” represents a polyvinyl butyral resin, “PC resin” represents a polycarbonate resin, “EVA resin” represents an ethylene-vinyl acetate copolymer resin, and “PMMA resin” represents a polymethyl resin. Methacrylate resin is shown. In Examples 2 to 11 and Comparative Examples 1 to 6, as in Example 1, an intermediate film obtained by using a mixture of magnesium acetate / 2-ethylbutyrate as a bonding force adjusting agent in a mass ratio of 1: 1 was obtained. Among them, the amount of magnesium used is 50 ppm. In Table 1, description of the compounding quantity of the adhesive force regulator was abbreviate | omitted.

DESCRIPTION OF

SYMBOLS

1, 12, 13, 14 ...

Intermediate film

2, 3 ... Laminated body 2a, 3a ... 1st surface of a laminated body 2b, 3b ... 2nd surface of a laminated body 11 ...

Unit

15, 16 ... Laminated glass 21 ... 1st DESCRIPTION OF SYMBOLS 1 thermoplastic resin layer 31 ... 2nd thermoplastic resin layer 41 ... 3rd layer 41a ... Outer surface of 3rd layer 42 ... 4th layer 42a ... Outer surface of 4th layer 51 ... 1st 1 laminated glass member 52 ... 2nd laminated glass member

Claims

A plurality of first thermoplastic resin layers containing a polyvinyl acetal resin and a plasticizer, and a plurality of second thermoplastic resin layers containing a thermoplastic resin,
The absolute value of the difference in intrinsic refractive index between the first thermoplastic resin layer and the second thermoplastic resin layer is 0.1 or more;
A plurality of the first thermoplastic resin layers and a plurality of the second thermoplastic resin layers are alternately laminated in the thickness direction,
An interlayer film for laminated glass, wherein the total number of laminated layers in the thickness direction of the plurality of first thermoplastic resin layers and the plurality of second thermoplastic resin layers is 500 or more.
The thickness per layer of the plurality of first thermoplastic resin layers is 50 nm or more and 700 nm or less,
The interlayer film for laminated glass according to claim 1, wherein the thickness of each of the plurality of second thermoplastic resin layers is 50 nm or more and 700 nm or less.
One or two second thermoplastic resin layers in contact with the surface on one or both sides, a first thermoplastic resin layer having a different thickness from that of one or two second thermoplastic resin layers, and one or two first in contact with the surfaces on one or both sides 3. The intermediate for laminated glass according to claim 1, wherein the thermoplastic resin layer and the second thermoplastic resin layer having a different thickness include a multilayer structure portion in which a total of 20 or more layers are alternately laminated in the thickness direction. film.
The interlayer film for laminated glass according to any one of claims 1 to 3, wherein the reflectance of incident light is 20% or less at an incident wavelength of 350 nm to 800 nm and 50% or more at an incident wavelength of 800 nm to 2500 nm. .
A first laminated glass member;
A second laminated glass member;
An interlayer film for laminated glass according to any one of claims 1 to 4,
Laminated glass in which the interlayer film for laminated glass is disposed between the first laminated glass member and the second laminated glass member.