阅读说明：本技术 层合玻璃用中间膜及层合玻璃 (Interlayer film for laminated glass and laminated glass ) 是由 北野纮史 乾浩彰 片山大希 松本学 中山和彦 于 2014-08-01 设计创作，主要内容包括：本发明的目的在于提供一种层叠有2层以上的树脂层的层合玻璃用中间膜、以及包含该层合玻璃用中间膜的层合玻璃,所述层合玻璃用中间膜是在层合玻璃的制造工序中具有优异的脱气性且能过防止产生多重像的层合玻璃用中间膜。本发明的层合玻璃用中间膜是层叠有2层以上的树脂层的层合玻璃用中间膜,其中,在至少一个表面具有多个凹部及多个凸部,所述凹部具有底部连续的槽形状,相邻的所述凹部平行且规则地排列,具有所述多个凹部及多个凸部的表面中,依据JISB-0601(1994)测定的凹部的槽深(Rzg)为10～40μm,且将具备具有所述多个凹部及多个凸部的表面的树脂层从该树脂层所直接相接的树脂层剥离之后,依据JISB0601(1994)对所剥离的具备具有多个凹部及多个凸部的表面的树脂层的所述直接相接的树脂层侧的表面进行测定而得的十点平均粗糙度(Rz)小于2.7μm。(The purpose of the present invention is to provide an interlayer film for laminated glass, which has excellent degassing properties in the production process of laminated glass and is capable of preventing the occurrence of multiple images, and to provide laminated glass comprising the interlayer film for laminated glass, wherein 2 or more resin layers are laminated. The interlayer film for laminated glass of the present invention is an interlayer film for laminated glass in which 2 or more resin layers are laminated, wherein at least one surface of the interlayer film has a plurality of recesses and a plurality of projections, the recesses have a groove shape with a continuous bottom, the adjacent recesses are arranged in parallel and regularly, and the surface having the plurality of recesses and the plurality of projections has a groove depth (Rzg) of 10 to 40 [ mu ] m as measured by JIS B-0601(1994), and after a resin layer having a surface having the plurality of recesses and the plurality of projections is peeled from a resin layer directly contacting the resin layer, the surface of the peeled resin layer having a surface having the plurality of recesses and the plurality of projections on the resin layer side directly contacting the resin layer has a ten-point average roughness (Rz) of less than 2.7 [ mu ] m as measured by JIS B0601 (1994).)

1. An interlayer film for laminated glass, comprising 2 or more resin layers laminated thereon, characterized in that,

a plurality of concave portions and a plurality of convex portions are provided on at least one surface, the concave portions have a groove shape with a continuous bottom, adjacent concave portions are arranged in parallel and regularly,

the surface having a plurality of concave portions and a plurality of convex portions has a groove depth Rzg of 10 to 40 μm measured in accordance with JIS B-0601(1994), and

after the resin layer having the surface having the plurality of concave portions and the plurality of convex portions is peeled from the resin layer directly contacting the resin layer, Rz, which is a ten-point average roughness measured according to JIS B0601(1994) on the surface on the side of the directly contacting resin layer of the peeled resin layer having the surface having the plurality of concave portions and the plurality of convex portions, is less than 2.7 μm.

2. The interlayer film for laminated glass according to claim 1,

the adjacent recesses are arranged in parallel at equal intervals.

3. The interlayer film for laminated glass according to claim 1 or 2,

the resin layer contains polyvinyl acetal and a plasticizer.

4. The interlayer film for laminated glass according to claim 3,

the intermediate film for laminated glass has at least a 1 st resin layer and a 2 nd resin layer, and the amount of hydroxyl groups of polyvinyl acetal contained in the 1 st resin layer is different from the amount of hydroxyl groups of polyvinyl acetal contained in the 2 nd resin layer.

5. The interlayer film for laminated glass according to claim 3,

the content of the plasticizer in the 1 st resin layer with respect to 100 parts by mass of polyvinyl acetal is different from the content of the plasticizer in the 2 nd resin layer with respect to 100 parts by mass of polyvinyl acetal.

6. An interlayer film for laminated glass comprising a sound insulating layer laminated between 2 protective layers,

the sound insulation layer contains 45-80 parts by mass of a plasticizer per 100 parts by mass of polyvinyl acetal, the protective layer contains 20-45 parts by mass of a plasticizer per 100 parts by mass of polyvinyl acetal,

the protective layer has a plurality of concave portions and a plurality of convex portions on at least one surface thereof, the concave portions have a groove shape with a continuous bottom, the adjacent concave portions are arranged in parallel and regularly,

the protective layer has a surface having a plurality of concave portions and a plurality of convex portions, wherein the groove depth of the concave portions, measured according to JIS B-0601(1994), is Rzg, which is 10 to 40 μm, and

after the protective layer having the surface with the plurality of concave portions and the plurality of convex portions is peeled off from the sound-insulating layer, Rz, which is the ten-point average roughness, measured in accordance with JIS B0601(1994) on the surface on the sound-insulating layer side of the peeled protective layer, is less than 2.7 μm.

7. A laminated glass characterized in that,

an interlayer film for laminated glass according to claim 1, 2, 3, 4, 5 or 6 is laminated between a pair of glass plates.

Technical Field

The present invention relates to an interlayer film for laminated glass, which has excellent degassing properties in a manufacturing process of laminated glass and can prevent multiple images, and to laminated glass including the interlayer film for laminated glass, in which 2 or more resin layers are laminated.

Background

Laminated glass obtained by sandwiching and bonding an interlayer film for laminated glass containing a thermoplastic resin such as plasticized polyvinyl butyral between 2 glass sheets is widely used as window glass for automobiles, airplanes, buildings, and the like.

The interlayer film for laminated glass is not limited to 1 resin layer, and may be a laminate of 2 or more resin layers. The interlayer film for laminated glass, which has 2 or more resin layers, includes a 1 st resin layer and a 2 nd resin layer, and the 1 st resin layer and the 2 nd resin layer have different properties, can be provided with various properties that are difficult to achieve by only 1 layer.

For example, patent document 1 discloses an interlayer film for laminated glass having a 3-layer structure including a sound-insulating layer and 2 protective layers sandwiching the sound-insulating layer. The interlayer film for laminated glass of patent document 1 has excellent sound insulation properties by having a sound insulation layer containing a polyvinyl acetal resin having excellent affinity with a plasticizer and a large amount of a plasticizer. On the other hand, the protective layer prevents a large amount of plasticizer contained in the sound-insulating layer from bleeding out to deteriorate the adhesion between the interlayer film and the glass.

However, in laminated glass using such an interlayer film for laminated glass in which 2 or more resin layers are laminated, there is a problem that when external light is observed through the laminated glass, multiple images are observed in the morning or optical distortion is observed. Such occurrence of multiple images or optical distortion is particularly remarkable in the case of an interlayer film for laminated glass having excellent sound insulation properties as described in patent document 1.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2007-331959

Disclosure of Invention

Problems to be solved by the invention

The present inventors have studied the cause of multiple images when using an interlayer film for laminated glass in which 2 or more resin layers are laminated. As a result, it was found that the reason is unevenness formed on the surface of the interlayer film for laminated glass.

In the production of laminated glass, a laminate in which an interlayer film for laminated glass is laminated between at least 2 glass plates is generally pressed by a nip roll (extrusion degassing method) or placed in a rubber bag and subjected to vacuum suction (vacuum degassing method), and pressure-bonded while degassing air remaining between the glass plates and the interlayer film. Next, the laminate is pressed by heating and pressurizing in, for example, an autoclave, thereby producing a laminated glass. In the production process of laminated glass, degassing properties when laminating glass and an interlayer film for laminated glass are important. At least one surface of the interlayer film for laminated glass is formed with fine irregularities in order to ensure degassing properties in the production of laminated glass. In particular, the concave portions of the irregularities have a groove shape with a continuous bottom (hereinafter also referred to as a "score line shape") and the adjacent score line-shaped concave portions are formed in parallel and regularly, whereby extremely excellent air release properties can be exhibited.

The irregularities formed on the surface of the interlayer film for laminated glass are usually destroyed at the time of pressure bonding in the laminated glass production process, and therefore hardly cause problems in the obtained laminated glass.

However, the present inventors have found that, in the case of an interlayer film for laminated glass in which 2 or more resin layers are laminated, the influence of irregularities remains in the laminated glass obtained through the laminated glass production process, and this causes multiple images.

That is, when the surface of the interlayer film for laminated glass in which 2 or more resin layers are laminated is formed with irregularities using an emboss roller or the like, it is considered that the irregularities are not only formed on the surface of the interlayer film, but also transferred to the interface between the layers of the resin layers due to the pressure during processing, and the interface becomes uneven. In particular, if a linear recessed portion is formed on the surface, the linear recessed portion is also likely to be significantly transferred to the interface between layers. When pressure bonding is performed in the laminated glass production process, the irregularities on the surface of the interlayer film are destroyed, but the irregularities transferred to the interface between the layers remain, and therefore the optical interference phenomenon due to the irregularities formed at the interface between the layers is considered to be a cause of the generation of multiple images. In particular, in the interlayer film for laminated glass having excellent sound insulating properties as described in patent document 1, when the irregularities are formed on the surface of the hard protective layer, the irregularities are likely to be transferred between the protective layer and the soft sound insulating layer, and thus, a multiple image is particularly likely to be generated.

The generation of multiple images can be prevented unless the surface of the interlayer film for laminated glass is uneven. However, if the unevenness is not formed, degassing is not sufficiently performed in the production of the laminated glass, and bubbles are generated between the glass and the interlayer film, resulting in deterioration of the appearance of the laminated glass.

In view of the above-described situation, an object of the present invention is to provide an interlayer film for laminated glass, which has excellent degassing properties in a process for producing laminated glass and can prevent the occurrence of multiple images, and a laminated glass including the interlayer film for laminated glass, in which 2 or more resin layers are laminated.

Means for solving the problems

The present invention is an interlayer film for laminated glass having laminated 2 or more resin layers, wherein at least one surface of the interlayer film has a plurality of recessed parts and a plurality of projecting parts, the recessed parts have a groove shape with a continuous bottom, the adjacent recessed parts are arranged in parallel and regularly, and the surface having the plurality of recessed parts and the plurality of projecting parts has a groove depth (Rzg) of 10 to 40 [ mu ] m as measured according to JIS B-0601(1994), and after a resin layer having a surface having the plurality of recessed parts and the plurality of projecting parts is peeled off from a resin layer directly contacting the resin layer, the surface of the resin layer having a surface having the plurality of recessed parts and the plurality of projecting parts on the side of the directly contacting resin layer has a ten-point average roughness (Rz) of less than 2.7 [ mu ] m as measured according to JIS B0601 (1994).

In the present invention, "a plurality of concave portions and a plurality of convex portions are provided on at least one surface" means "a plurality of concave portions and a plurality of convex portions are provided on at least one surface," a concave portion has a groove shape with a continuous bottom, and adjacent concave portions are arranged in parallel and regularly "means" a concave portion has a groove shape with a continuous bottom, and adjacent concave portions are formed in parallel and regularly ".

The present invention will be described in detail below.

As a result of intensive studies, the present inventors have found that, while the roughness of the irregularities transferred to the interface between the resin layer having the surface formed with the irregularities and the resin layer directly contacting the resin layer is suppressed to a certain value or less, even in an interlayer film for laminated glass in which 2 or more resin layers are laminated, excellent degassing properties in the production of laminated glass and the prevention of the occurrence of multiple images can be achieved at the same time, and have completed the present invention.

The interlayer film for laminated glass of the present invention has a plurality of concave portions and a plurality of convex portions on at least one surface. This ensures degassing properties in the production of laminated glass.

The above-described unevenness may be provided on only one surface, but it is preferable to provide the unevenness on both surfaces of the interlayer film for laminated glass, from the viewpoint of remarkably improving the degassing property.

The shape of the above-mentioned unevenness may have at least a groove shape, and for example, a shape of unevenness usually given to the surface of the interlayer film for laminated glass, such as an engraved line shape or a mesh shape, may be used. The shape of the unevenness may be a shape transferred by the emboss roller.

The convex portion may have a planar top portion as shown in fig. 1, or may have a non-planar top portion as shown in fig. 2. When the top of the projection is planar, fine irregularities may be further formed on the planar surface of the top.

The height of the convex portion of each concave-convex portion may be the same height or different heights, and the depth of the concave portion corresponding to the convex portion may be the same depth or different depths as long as the bottom side of the concave portion is continuous.

In the interlayer film for laminated glass of the present invention, the concave portions of the irregularities on at least one surface have a groove shape (linear shape) with a continuous bottom, and the adjacent concave portions are arranged in parallel and regularly. Generally, the ease of removal of air when pressure bonding a laminate in which an interlayer film for laminated glass is laminated between 2 glass plates is closely related to the connectivity and smoothness of the bottom of the concave portion. By forming the shape of the irregularities on at least one surface of the interlayer film into a shape in which the linear recesses are arranged in parallel and regularly, the above-described connectivity of the bottom is further improved, and the outgassing property is significantly improved.

The term "regularly arranged" means that the adjacent linear recesses may be arranged in parallel at equal intervals, or the adjacent linear recesses may be arranged in parallel, but the intervals between all the adjacent linear recesses are not equal.

Fig. 1 and 2 are schematic views showing an example of an interlayer film for laminated glass in which linear recesses are arranged in parallel at equal intervals.

Fig. 3 is a schematic view showing an example of an interlayer film for laminated glass in which linear recesses are arranged in parallel at unequal intervals. In fig. 3, the interval a between the concave portions 1 and 2 and the interval B between the concave portions 1 and 3 are different.

In the surface having a plurality of concave portions and a plurality of convex portions, the depth (Rzg) of the concave portions is 10 to 40 μm. By setting the groove depth (Rzg) to 10 μm or more, extremely excellent degassing properties can be exhibited, and by setting the groove depth to 40 μm or less, the temperature at the time of producing the laminated glass can be lowered. The lower limit of the groove depth (Rzg) is preferably 15 μm, the upper limit is preferably 35 μm, the lower limit is more preferably 20 μm, and the upper limit is more preferably 30 μm.

In the present specification, the groove depth (Rzg) of the concave portion is an average value obtained by calculating a groove depth defined in JIS B-0601(1994) "surface roughness-definition and expression" and having a reference length of 2.5mm based on an average line of a roughness curve (a line set so that the sum of squares of deviations from the roughness curve is minimized) and taking the groove depth of the measured number of grooves. The number of grooves is an integer obtained by rounding up or down a decimal point obtained by dividing the reference length by the interval between the concave portions. When the number of grooves is 5 or more, the groove depths at 5 are calculated in the order of the deepest recessed portion existing in the reference length, and the average value thereof is taken as the groove depth per unit reference length. When the number of grooves is 4 or less, the groove depths of the plurality of grooves are calculated in the order of the deepest recess portion existing in the reference length, and the average value thereof is taken as the groove depth per unit reference length. At least the groove depth per unit reference length at 5 points is measured, and the average value is defined as the groove depth of the recessed portion (Rzg). The groove depth (Rzg) can be easily obtained by, for example, data processing of a digital signal measured by a surface roughness measuring instrument (Kosaka Laboratory ltd., SE1700 α).

In the present invention, examples of a method for forming a plurality of concave portions and a plurality of convex portions on at least one surface of an interlayer film for laminated glass include an embossing roll method, a calender roll method, a profile extrusion method, and an extrusion-lip embossing method (extrusion-lip embossing method) using melt fracture. Among them, the emboss roller method is preferable in that a shape in which adjacent linear depressions are arranged in parallel and regularly can be easily obtained.

As the emboss roller used in the emboss roller method, for example, there is an emboss roller having an embossed pattern (concave-convex pattern) on the roller surface by sand blasting the surface of a metal roller with an abrasive material such as alumina or silica and then polishing it with vertical polishing or the like in order to reduce excessive peaks on the surface. Further, there is also an emboss roller having an emboss pattern (concave-convex pattern) on the roller surface by transferring the emboss pattern (concave-convex pattern) of an engraver mill (mother mill) to the surface of a metal roller using the engraver mill. Further, there are an emboss roller and the like in which an emboss pattern (concave-convex pattern) is formed on the surface of the roller by etching (etching).

In the interlayer film for laminated glass of the present invention, a resin layer having a surface having a plurality of recessed portions and a plurality of projecting portions (hereinafter also referred to as a "surface uneven resin layer") is peeled off from a resin layer directly contacting the surface uneven resin layer, and then the ten-point average roughness (Rz) of the surface of the peeled surface uneven resin layer contacting the resin layer is measured in accordance with JIS B0601(1994) and is less than 2.7 μm.

As described above, the multiple images and the like are generated due to the irregularities transferred to the interface between the resin layers, but it is difficult to directly observe the irregularities of the interface between the resin layers. Instead of directly observing the irregularities of the interface between the resin layers, the irregularities transferred to the interface between the resin layers can be indirectly evaluated by peeling the directly contacting resin layers and measuring the ten-point average roughness of the surface of the resin layer after peeling, and the generation of multiple images due to the transferred irregularities can be suppressed by making the roughness of the irregularities smaller than a certain value.

The interlayer film for laminated glass of fig. 4 has a 2-layer structure in which a resin layer 20 and a resin layer 10 are laminated, and the resin layer 20 has a surface 21 having a plurality of concave portions and a plurality of convex portions. In the present invention, after the resin layer 20 was peeled from the resin layer 10 of the 2-layer substantially structured intermediate film for laminated glass, the surface ten-point average roughness (Rz) of the surface 22 of the peeled resin layer 20 on the side in contact with the resin layer 10 was measured.

The interlayer film for laminated glass of fig. 5 has a 3-layer structure in which a resin layer 20, a resin layer 10, and a resin layer 30 are sequentially laminated, and the resin layer 20 has a surface 21 having a plurality of concave portions and a plurality of convex portions. In the present invention, after the resin layer 20 was peeled from the resin layer 10 of the 3-layer interlayer for laminated glass, the ten-point average roughness (Rz) of the surface 22 of the peeled resin layer 20 on the side contacting the resin layer 10 was measured.

The resin layers directly contacting each other are peeled off at a speed of 10 to 15cm/s in an environment of 25 ℃ and 30% humidity. By making the temperature, humidity, and peeling speed constant, variations in the measured values can be suppressed. If this condition is satisfied, peeling may be performed by a machine or manually with a finger.

When the ten-point average roughness is measured immediately after the peeling of the directly-contacting resin layers, the measured value may vary. Therefore, it is preferable to measure the ten-point average roughness after standing for 2 hours in an environment of 25 ℃ and 30% humidity. After the surface uneven resin layer was peeled off under a certain condition and left to stand, the ten-point average roughness of the surface of the peeled surface uneven resin layer on the side contacting the resin layer was measured.

The ten-point average roughness in the present specification is a roughness measured according to the specification of "surface roughness-definition and expression" in JIS B0601 (1994). In addition, the ten-point average roughness can be easily measured using, for example, a high-precision shape measuring system ("KS-1100" manufactured by Keyence Corporation, front end detection head model "LT-9510 VM") or the like.

The ten-point average roughness of the surface of the peeled uneven-surface resin layer on the side in contact with the resin layer was less than 2.7 μm. By setting the ten-point average roughness to less than 2.7 μm, generation of multiple images can be suppressed. The ten-point average roughness is preferably 2.3 μm or less, more preferably 1.9 μm or less, and still more preferably 1.7 μm or less. By setting the ten-point average roughness to the above preferable upper limit or less, generation of multiple images can be further suppressed. The lower limit of the ten-point average roughness is not particularly limited, but is preferably 0.001 μm or more.

In order to make the ten-point average roughness of the surface of the peeled surface uneven resin layer on the side contacting the resin layer smaller than 2.7 μm, for example, a combination of (1) increasing the thickness of the surface uneven resin layer, (2) making the groove depth (Rzg) of the surface shallow, (3) reducing the interval between adjacent groove-like recesses (hereinafter also referred to as "interval between recesses") of the surface to disperse the pressure at the time of forming the recesses, and (4) reducing the pressing pressure or pressing line pressure at the time of forming the unevenness on the surface can be given.

When the surface unevenness is formed on the surface by using an embossing roll or the like, the thickness of the surface unevenness resin layer can be increased to reduce the pressure on the resin layer in direct contact with the embossing roll or the like, thereby suppressing transfer of the unevenness to the interface. That is, in order to set the ten-point average roughness of the surface of the peeled surface uneven resin layer on the side contacting the resin layer to less than 2.7 μm, it is preferable to increase the thickness of the surface uneven resin layer as much as possible within a range not to impair the purpose of forming a multilayer structure.

The thickness of the surface uneven resin layer for making the ten-point average roughness of the surface of the peeled surface uneven resin layer on the side contacting the resin layer smaller than 2.7 μm is not particularly limited as long as it is determined by the material of the surface uneven resin layer or the resin layer directly contacting the surface uneven resin layer, but is preferably 100 to 500 μm, more preferably 300 to 500 μm in a general interlayer film for laminated glass. For example, when the surface of the protective layer is formed with irregularities in the sound-insulating interlayer film described later, the thickness of the protective layer is preferably 100 μm or more. By setting the thickness of the protective layer to 100 μm or more, the transfer of the irregularities to the interface can be suppressed. The thickness of the protective layer is more preferably 300 μm or more, still more preferably 400 μm or more, and particularly preferably 450 μm or more. The upper limit of the thickness of the protective layer is not particularly limited, but in practice 500 μm is the upper limit in order to secure a thickness of the sound insulating layer that can achieve a sufficient degree of sound insulating property.

By making the groove depth (Rzg) shallow, the ten-point average roughness of the surface of the peeled uneven-surface resin layer on the side in contact with the resin layer can also be reduced. As described above, in order to exhibit excellent outgassing property at the time of pressure bonding, the groove depth (Rzg) needs to be 10 μm or more, and by reducing the groove depth as much as possible within a range satisfying this condition, it is possible to suppress transfer of irregularities to the interface between the resin layers.

By reducing the interval between the linear recessed portions, the ten-point average roughness of the surface of the peeled uneven-surface resin layer on the side in contact with the resin layer can be reduced.

The interval of the linear recessed portions for setting the ten-point average roughness of the surface of the peeled surface uneven resin layer on the side contacting the resin layer to less than 2.7 μm is not particularly limited as long as it is determined by the material and the like of the surface uneven resin layer or the resin layer directly contacting the surface uneven resin layer, but is preferably 500 μm or less in a general interlayer film for laminated glass. For example, when the surface of the protective layer is formed with irregularities in the sound-insulating interlayer film described later, the interval between the groove-like recesses is preferably 500 μm or less. By setting the interval between the groove-like recesses to 500 μm or less, the transfer of the irregularities to the interface between the resin layers can be suppressed. The pitch of the linear recessed portions is more preferably 400 μm or less, still more preferably 300 μm or less, and most preferably 250 μm or less. The lower limit of the interval between the linear recessed portions is also not particularly limited, but from the viewpoint of workability in producing the laminated glass, 10 μm is actually the lower limit.

In addition, the interval of the scribed line-shaped recessed portions in this specification means the shortest distance between the bottommost portions of the 2 recessed portions in the adjacent scribed line-shaped recessed portions. Specifically, with respect to the intervals of the above-described recesses, the surface (observation range 20mm × 20mm) of the interlayer film for laminated glass was observed using an optical microscope (for example, manufactured by SONIC Corporation, BS-8000III), and the shortest distance between the bottommost portions of all the observed adjacent recesses was measured. Next, the average value of the measured shortest distances is calculated, thereby obtaining the intervals of the concave portions. The maximum value of the measured shortest distance may be set as the interval between the concave portions. The interval between the concave portions may be an average value of the shortest distances or a maximum value of the shortest distances, but is preferably an average value of the shortest distances.

The ten-point average roughness of the surface of the peeled uneven-surface resin layer on the side contacting the resin layer can be reduced by adjusting the pressing pressure or pressing line pressure at the time of forming unevenness on the surface. For example, when the surface is formed with irregularities by using an emboss roller, the temperature, the roller temperature, the linear velocity, the press pressure, or the press linear pressure of the intermediate film for laminated glass is adjusted as the transfer condition. By adjusting the transfer conditions such as the pressing pressure and the pressing line pressure at this time, the transfer of the unevenness to the interface between the resin layers can be suppressed.

The interlayer film for laminated glass of the present invention comprises 2 or more resin layers laminated thereon. For example, the interlayer film for laminated glass having various properties that are difficult to realize by only 1 layer can be provided by having the 1 st resin layer and the 2 nd resin layer as the 2 or more resin layers and having different properties between the 1 st resin layer and the 2 nd resin layer. On the other hand, when 2 or more resin layers are laminated, a problem of multiple images occurs.

Preferably, the resin layer contains a thermoplastic resin.

Examples of the thermoplastic resin include polyvinylidene fluoride, polytetrafluoroethylene, a vinylidene fluoride-hexafluoropropylene copolymer, polytrifluoroethylene, an acrylonitrile-butadiene-styrene copolymer, a polyester, a polyether, a polyamide, a polycarbonate, a polyacrylate, a polymethacrylate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, a polyvinyl acetal, an ethylene-vinyl acetate copolymer, and the like. Among them, the resin layer preferably contains polyvinyl acetal or an ethylene vinyl acetate copolymer, and more preferably contains polyvinyl acetal.

Preferably, the resin layer contains polyvinyl acetal and a plasticizer.

The plasticizer is not particularly limited as long as it is a plasticizer generally used for an interlayer film for laminated glass, and examples thereof include organic plasticizers such as monobasic organic acid esters and polybasic organic acid esters, phosphoric acid plasticizers such as organic phosphoric acid compounds and organic phosphorous acid compounds, and the like.

Examples of the organic plasticizer include triethylene glycol di-2-ethylhexanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, tetraethylene glycol di-2-ethylbutyrate, tetraethylene glycol di-n-heptanoate, diethylene glycol di-2-ethylhexanoate, diethylene glycol di-2-ethylbutyrate, and diethylene glycol di-n-heptanoate. Among them, the above resin layer preferably contains triethylene glycol-di-2-ethylhexanoate, triethylene glycol-di-2-ethylbutyrate, or triethylene glycol-di-n-heptanoate, and more preferably contains triethylene glycol-di-2-ethylhexanoate.

The resin layer preferably contains an adhesive strength adjuster. In particular, when producing a laminated glass, the resin layer in contact with the glass preferably contains the above adhesion modifier.

As the adhesion modifier, for example, an alkali metal salt or an alkaline earth metal salt can be suitably used. Examples of the adhesion modifier include salts of potassium, sodium, magnesium, and the like.

Examples of the acid constituting the salt include carboxylic organic acids such as octanoic acid, hexanoic acid, 2-ethylbutyric acid, butyric acid, acetic acid, and formic acid, and inorganic acids such as hydrochloric acid and nitric acid. From the viewpoint of easily adjusting the adhesion between the glass and the resin layer in the production of the laminated glass, the resin layer in contact with the glass preferably contains a magnesium salt as an adhesion modifier.

The resin layer may contain additives such as an antioxidant, a light stabilizer, a modified silicone oil as an adhesive force adjuster, a flame retardant, an antistatic agent, a moisture resistant agent, a heat reflecting agent, and a heat absorbing agent, as required.

The interlayer film for laminated glass of the present invention preferably has at least a 1 st resin layer and a 2 nd resin layer as 2 or more resin layers, and the amount of hydroxyl groups in polyvinyl acetal (hereinafter referred to as polyvinyl acetal a) contained in the 1 st resin layer is different from the amount of hydroxyl groups in polyvinyl acetal (hereinafter referred to as polyvinyl acetal B) contained in the 2 nd resin layer.

Since polyvinyl acetal a and polyvinyl acetal B have different properties, an intermediate film for laminated glass having various properties that are difficult to achieve only by 1 layer can be provided. For example, when the 1 st resin layer is laminated between the 2 nd resin layers of the 2 layers and the amount of hydroxyl groups of the polyvinyl acetal a is smaller than the amount of hydroxyl groups of the polyvinyl acetal B, the 1 st resin layer tends to have a lower glass transition temperature than the 2 nd resin layer. As a result, the 1 st resin layer becomes softer than the 2 nd resin layer, and the interlayer film for laminated glass has higher sound insulation properties. In addition, when the 1 st resin layer is laminated between the 2 nd resin layers of the 2 layers and the hydroxyl group content of the polyvinyl acetal a is higher than that of the polyvinyl acetal B, the 1 st resin layer tends to have a higher glass transition temperature than the 2 nd resin layer. As a result, the 1 st resin layer becomes harder than the 2 nd resin layer, and the interlayer film for laminated glass has high penetration resistance.

In addition, when the 1 st resin layer and the 2 nd resin layer contain a plasticizer, the content of the plasticizer with respect to 100 parts by mass of polyvinyl acetal (hereinafter referred to as content a) in the 1 st resin layer is preferably different from the content of the plasticizer with respect to 100 parts by mass of polyvinyl acetal (hereinafter referred to as content B) in the 2 nd resin layer. For example, in the case where the 1 st resin layer is laminated between the 2 nd resin layers of the 2 layers and the content a is larger than the content B, the 1 st resin layer tends to have a lower glass transition temperature than the 2 nd resin layer. As a result, the 1 st resin layer becomes softer than the 2 nd resin layer, and the interlayer film for laminated glass has higher sound insulation properties. In addition, when the 1 st resin layer is laminated between the 2 nd resin layers of the 2 layers and the content a is smaller than the content B, the 1 st resin layer tends to have a higher glass transition temperature than the 2 nd resin layer. As a result, the 1 st resin layer becomes harder than the 2 nd resin layer, and the interlayer film for laminated glass has high penetration resistance.

As a combination of 2 or more resin layers constituting the interlayer film for laminated glass of the present invention, for example, in order to improve the sound insulation property of the laminated glass, a combination of the above-described 1 st resin layer as a sound insulation layer and the above-described 2 nd resin layer as a protective layer may be mentioned. From the viewpoint of improving the sound-insulating property of the laminated glass, it is preferable that the sound-insulating layer contains polyvinyl acetal X and a plasticizer, and the protective layer contains polyvinyl acetal Y and a plasticizer. When the sound-insulating layer is laminated between 2 protective layers, an interlayer film for laminated glass (hereinafter also referred to as a sound-insulating interlayer film) having excellent sound-insulating properties can be obtained. In the present invention, as in the sound insulating layer and the protective layer, even when resin layers having different properties are laminated, an interlayer film for laminated glass capable of preventing occurrence of multiple images can be obtained. Hereinafter, the sound-insulating interlayer will be described in more detail.

In the sound-insulating interlayer, the sound-insulating layer has a function of imparting sound-insulating properties.

The sound insulating layer preferably contains polyvinyl acetal X and a plasticizer.

The polyvinyl acetal X can be produced by acetalizing polyvinyl alcohol with an aldehyde. The polyvinyl alcohol is generally obtained by saponifying polyvinyl acetate. The average polymerization degree of the polyvinyl alcohol preferably has a lower limit of 200 and an upper limit of 5000. By setting the average polymerization degree of the polyvinyl alcohol to 200 or more, the penetration resistance of the obtained sound-insulating interlayer can be improved, and by setting the average polymerization degree to 5000 or less, the moldability of the sound-insulating layer can be ensured. A more preferable lower limit of the average polymerization degree of the polyvinyl alcohol is 500, and a more preferable upper limit thereof is 4000.

The average polymerization degree of the polyvinyl alcohol is determined by a method in accordance with JIS K6726 "polyvinyl alcohol test method".

The lower limit of the number of carbon atoms of the aldehyde for acetalizing the polyvinyl alcohol is preferably 4, and the upper limit thereof is preferably 6. By setting the number of carbon atoms of the aldehyde to 4 or more, a sufficient amount of the plasticizer can be stably contained, and excellent sound insulation performance can be exhibited. Further, the bleed-out of the plasticizer can be prevented. When the number of carbon atoms of the aldehyde is 6 or less, the polyvinyl acetal X can be easily synthesized, and productivity can be ensured.

The aldehyde having 4 to 6 carbon atoms may be a linear aldehyde or a branched aldehyde, and examples thereof include n-butyraldehyde and n-valeraldehyde.

The preferable upper limit of the amount of the hydroxyl group in the polyvinyl acetal X is 30 mol%. When the amount of the hydroxyl group in the polyvinyl acetal X is 30 mol% or less, the plasticizer can be contained in an amount necessary for exhibiting sound-insulating properties, and bleeding of the plasticizer can be prevented. The amount of the hydroxyl group in the polyvinyl acetal X is preferably 28 mol% at the upper limit, more preferably 26 mol% at the upper limit, even more preferably 24 mol% at the upper limit, more preferably 10 mol% at the lower limit, more preferably 15 mol% at the lower limit, and even more preferably 20 mol% at the lower limit.

The hydroxyl group content of the polyvinyl acetal X 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, which is expressed in percentage (mol%). The amount of the hydroxyl group-bonded ethylene group can be determined by measuring the amount of the hydroxyl group-bonded ethylene group of the polyvinyl acetal X by a method in accordance with JIS K6728 "polyvinyl butyral test method", for example.

The lower limit of the amount of acetal groups in the polyvinyl acetal X is preferably 60 mol%, and the upper limit is preferably 85 mol%. When the amount of acetal group of the polyvinyl acetal X is 60 mol% or more, the water repellency of the sound-insulating layer can be improved, and the plasticizer can be contained in an amount necessary for exhibiting sound-insulating properties, whereby bleeding or whitening of the plasticizer can be prevented. By setting the amount of acetal groups of the polyvinyl acetal X to 85 mol% or less, the synthesis of the polyvinyl acetal X can be facilitated, and productivity can be ensured. The lower limit of the amount of the acetal group in the polyvinyl acetal X is more preferably 65 mol%, and still more preferably 68 mol% or more.

The amount of acetal groups can be determined by measuring the amount of acetal groups bonded to the polyvinyl acetal X by a method in accordance with JIS K6728 "polyvinyl butyral test method".

The lower limit of the amount of the acetyl group in the polyvinyl acetal X is preferably 0.1 mol%, and the upper limit is preferably 30 mol%. When the acetyl group content of the polyvinyl acetal X is 0.1 mol% or more, the plasticizer can be contained in an amount necessary for exhibiting sound-insulating properties, and bleeding can be prevented. Further, by setting the acetyl group amount of the polyvinyl acetal X to 30 mol% or less, the hydrophobicity of the sound-insulating layer can be increased, and whitening can be prevented. The lower limit of the amount of the acetyl group is more preferably 1 mol%, the lower limit is still more preferably 5 mol%, the lower limit is particularly preferably 8 mol%, the upper limit is still more preferably 25 mol%, and the upper limit is still more preferably 20 mol%. The acetyl group amount is a value obtained by subtracting the amount of the acetal group-bonded ethylene group and the amount of the hydroxyl group-bonded ethylene group from the total amount of ethylene groups in the main chain in percentage (mol%) and dividing the value by the total amount of ethylene groups in the main chain.

In particular, from the viewpoint of easily containing the plasticizer in an amount necessary for the sound-insulating layer to exhibit sound-insulating properties, the polyvinyl acetal X is preferably a polyvinyl acetal having an acetyl group amount of 8 mol% or more, or a polyvinyl acetal having an acetyl group amount of less than 8 mol% and an acetal group amount of 65 mol% or more. More preferably, the polyvinyl acetal X is a polyvinyl acetal having an acetyl group amount of 8 mol% or more, or a polyvinyl acetal having an acetyl group amount of less than 8 mol% and an acetal group amount of 68 mol% or more.

In the sound-insulating layer, the lower limit of the content of the plasticizer is preferably 45 parts by mass and the upper limit is preferably 80 parts by mass with respect to 100 parts by mass of the polyvinyl acetal X. By setting the content of the plasticizer to 45 parts by mass or more, high sound insulation can be exhibited, and by setting the content to 80 parts by mass or less, bleeding of the plasticizer can be prevented from occurring and deterioration of transparency and adhesiveness of the interlayer film for laminated glass can be prevented. The lower limit of the content of the plasticizer is more preferably 50 parts by mass, the lower limit is more preferably 55 parts by mass, the upper limit is more preferably 75 parts by mass, and the upper limit is more preferably 70 parts by mass.

The preferable lower limit of the thickness of the above-mentioned sound-deadening layer is 50 μm. By setting the thickness of the sound insulating layer to 50 μm or more, sufficient sound insulating properties can be exhibited. A more preferable lower limit of the thickness of the soundproof layer is 80 μm. The upper limit is not particularly limited, but considering the thickness of the interlayer film for laminated glass, the upper limit is preferably 300 μm.

The protective layer has the effect of preventing the interlayer film for laminated glass from being deteriorated in adhesion to glass due to the bleed-out of a large amount of the plasticizer contained in the sound-insulating layer, and imparting penetration resistance to the interlayer film for laminated glass.

The protective layer preferably contains, for example, polyvinyl acetal Y and a plasticizer, and more preferably contains polyvinyl acetal Y having a larger hydroxyl group content than polyvinyl acetal X and a plasticizer.

The polyvinyl acetal Y can be produced by acetalizing polyvinyl alcohol with an aldehyde.

The polyvinyl alcohol is generally obtained by saponifying polyvinyl acetate.

The average polymerization degree of the polyvinyl alcohol preferably has a lower limit of 200 and an upper limit of 5000. The penetration resistance of the interlayer film for laminated glass can be improved by setting the average polymerization degree of the polyvinyl alcohol to 200 or more, and the moldability of the protective layer can be ensured by setting the average polymerization degree of the polyvinyl alcohol to 5000 or less. A more preferable lower limit of the average polymerization degree of the polyvinyl alcohol is 500, and a more preferable upper limit thereof is 4000.

The preferred lower limit of the number of carbon atoms of the aldehyde for acetalizing the polyvinyl alcohol is 3, and the preferred upper limit is 4. When the number of carbon atoms of the aldehyde is 3 or more, the penetration resistance of the interlayer film for laminated glass is increased. When the number of carbon atoms of the aldehyde is 4 or less, the productivity of the polyvinyl acetal Y is improved.

The aldehyde having 3 to 4 carbon atoms may be a linear aldehyde or a branched aldehyde, and examples thereof include n-butyraldehyde.

The preferable upper limit of the amount of the hydroxyl group in the polyvinyl acetal Y is 33 mol%, and the preferable lower limit is 28 mol%. When the amount of hydroxyl groups in the polyvinyl acetal Y is 33 mol% or less, whitening of the interlayer film for laminated glass can be prevented. When the amount of hydroxyl groups in the polyvinyl acetal Y is 28 mol% or more, the penetration resistance of the interlayer film for laminated glass is increased.

The lower limit of the amount of acetal groups in the polyvinyl acetal Y is preferably 60 mol%, and the upper limit is preferably 80 mol%. By setting the amount of the acetal group to 60 mol% or more, a plasticizer can be contained in an amount necessary for exhibiting sufficient penetration resistance. By setting the amount of acetal groups to 80 mol% or less, the adhesion between the protective layer and the glass can be secured. The lower limit of the amount of the acetal group is more preferably 65 mol% and the upper limit is more preferably 69 mol%.

The preferable upper limit of the acetyl group amount of the polyvinyl acetal Y is 7 mol%. When the acetyl group content of the polyvinyl acetal Y is 7 mol% or less, the hydrophobicity of the protective layer can be increased, and whitening can be prevented. The upper limit of the amount of the acetyl group is more preferably 2 mol%, and the lower limit is preferably 0.1 mol%. The amounts of hydroxyl groups, acetal groups and acetyl groups in the polyvinyl acetals A, B and Y can be measured by the same methods as in the polyvinyl acetal X.

In the protective layer, the lower limit of the content of the plasticizer is preferably 20 parts by mass and the upper limit thereof is preferably 45 parts by mass with respect to 100 parts by mass of the polyvinyl acetal Y. The penetration resistance can be ensured by setting the content of the plasticizer to 20 parts by mass or more, and the bleed-out of the plasticizer can be prevented and the deterioration of the transparency and adhesiveness of the interlayer film for laminated glass can be prevented by setting the content of the plasticizer to 45 parts by mass or less. The lower limit of the content of the plasticizer is more preferably 30 parts by mass, the lower limit is more preferably 35 parts by mass, the upper limit is more preferably 43 parts by mass, and the upper limit is more preferably 41 parts by mass. From the viewpoint of further improving the sound insulating property of the laminated glass, the content of the plasticizer in the protective layer is preferably smaller than the content of the plasticizer in the sound insulating layer.

From the viewpoint of further improving the sound insulating property of the laminated glass, the amount of hydroxyl groups in the polyvinyl acetal Y is preferably larger than the amount of hydroxyl groups in the polyvinyl acetal X, more preferably 1 mol% or more, still more preferably 5 mol% or more, and particularly preferably 8 mol% or more. By adjusting the amounts of hydroxyl groups in the polyvinyl acetal X and the polyvinyl acetal Y, the contents of the plasticizer in the sound-insulating layer and the protective layer can be controlled, and the glass transition temperature of the sound-insulating layer can be lowered. As a result, the sound insulation property of the laminated glass is further improved.

In addition, from the viewpoint of further improving the sound insulating property of the laminated glass, the content of the plasticizer (hereinafter, also referred to as content X) with respect to 100 parts by mass of the polyvinyl acetal X in the sound insulating layer is preferably larger than the content of the plasticizer (hereinafter, also referred to as content Y) with respect to 100 parts by mass of the polyvinyl acetal Y in the protective layer, more preferably larger than 5 parts by mass or more, further preferably larger than 15 parts by mass or more, and particularly preferably larger than 20 parts by mass or more. By adjusting the content X and the content Y, the glass transition temperature of the sound-insulating layer is lowered. As a result, the sound insulation property of the laminated glass is further improved.

The thickness of the protective layer may be adjusted within a range in which the function of the protective layer can be exerted, and is not particularly limited. However, when the protective layer has irregularities, it is preferable to increase the thickness of the protective layer to a possible extent so as to prevent the irregularities from being transferred to the interface with the sound insulating layer in direct contact therewith. Specifically, the lower limit of the thickness of the protective layer is preferably 100 μm, more preferably 300 μm, still more preferably 400 μm, and particularly preferably 450 μm. The upper limit of the thickness of the protective layer is not particularly limited, but in practice, about 500 μm is the upper limit in order to ensure the thickness of the sound insulating layer to a level that can achieve sufficient sound insulating properties.

The method for producing the sound-insulating intermediate film is not particularly limited, and examples thereof include a method in which the sound-insulating layer and the protective layer are formed into a sheet shape by a general film-forming method such as an extrusion method, a rolling method, or a pressing method, and then laminated.

An interlayer film for laminated glass in which a sound-insulating layer is laminated between 2 protective layers is also one aspect of the present invention, in the interlayer film for laminated glass, the sound insulation layer contains 45-80 parts by mass of a plasticizer per 100 parts by mass of polyvinyl acetal, the protective layer contains 20 to 45 parts by mass of a plasticizer per 100 parts by mass of polyvinyl acetal, the protective layer has a plurality of concave portions and a plurality of convex portions on at least one surface thereof, the concave portions have a groove shape with a continuous bottom, the adjacent concave portions are arranged in parallel and regularly, the protective layer has a surface having a plurality of concave portions and a plurality of convex portions, and the depth (Rzg) of the concave portions is 10 to 40 μm as measured according to JIS B-0601(1994), and the protective layer having the surface with a plurality of concave portions and a plurality of convex portions is peeled off from the sound-insulating layer, the ten-point average roughness of the surface of the peeled protective layer on the sound-proofing layer side was less than 2.7 μm as measured in accordance with JIS B0601 (1994).

In the present invention, "a plurality of concave portions and a plurality of convex portions are provided on the surface of at least one protective layer" means "a plurality of concave portions and a plurality of convex portions are provided on the surface of at least one protective layer," a concave portion has a groove shape with a continuous bottom, and adjacent concave portions are arranged in parallel and regularly "means" a concave portion has a groove shape with a continuous bottom, and adjacent concave portions are formed in parallel and regularly.

The laminated glass of the present invention is also one of the present invention, in which the interlayer film for laminated glass is laminated between a pair of glass plates.

The glass plate may be a transparent plate glass which is generally used. Examples of the inorganic glass include float glass, polished glass, embossed glass, screen glass, wired glass, colored glass, heat-absorbing glass, heat-reflecting glass, and green glass. In addition, an ultraviolet shielding glass having an ultraviolet shielding coating layer on the surface of the glass can also be used. Further, organic plastic plates such as polyethylene terephthalate, polycarbonate, and polyacrylate can also be used.

As the glass plate, 2 or more kinds of glass plates can be used. For example, a laminated glass in which the interlayer film for laminated glass of the present invention is laminated between a transparent float glass and a colored flat glass such as a green glass can be given. As the glass plate, 2 or more glass plates having different thicknesses can be used.

The method for producing the laminated glass of the present invention is not particularly limited, and conventionally known production methods can be used.

Effects of the invention

According to the present invention, it is possible to provide an interlayer film for laminated glass in which 2 or more resin layers are laminated, which has excellent degassing properties in a process of manufacturing laminated glass and can prevent the occurrence of multiple images, and a laminated glass including the interlayer film for laminated glass.

Drawings

Fig. 1 is a schematic view showing an example of an interlayer film for laminated glass in which groove-shaped recesses having continuous bottoms are arranged at equal intervals and adjacent recesses are arranged in parallel on the surface.

Fig. 2 is a schematic view showing an example of an interlayer film for laminated glass in which groove-shaped recesses having continuous bottoms are arranged at equal intervals and adjacent recesses are arranged in parallel on the surface.

Fig. 3 is a schematic view showing an example of an interlayer film for laminated glass in which groove-shaped recesses having continuous bottoms are not equally spaced, but adjacent recesses are arranged in parallel on the surface.

Fig. 4 is a schematic view illustrating a surface of the interlayer film for laminated glass having a 2-layer structure, on which ten-point average roughness (Rz) is measured.

Fig. 5 is a schematic view illustrating a surface of the interlayer film for laminated glass having a 3-layer structure, on which ten-point average roughness (Rz) is measured.

Detailed Description

The mode of the present invention will be described in further detail below with reference to examples, but the present invention is not limited to these examples.

(example 1)

(1) Preparation of resin composition for soundproof layer

100 parts by mass of polyvinyl butyral (having an acetyl group content of 12 mol%, a butyral group content of 66 mol%, and a hydroxyl group content of 22 mol%) obtained by acetalizing polyvinyl alcohol having an average polymerization degree of 2400 with n-butyl aldehyde was mixed with 60 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer and sufficiently kneaded with a kneading roll to obtain a resin composition for a sound-insulating layer.

(2) Preparation of resin composition for protective layer

100 parts by mass of polyvinyl butyral (containing 1 mol% of acetyl groups, 69 mol% of butyral groups, and 30 mol% of hydroxyl groups) obtained by acetalizing polyvinyl alcohol having an average polymerization degree of 1700 with n-butyraldehyde was sufficiently kneaded with 40 parts by mass of triethylene glycol-di-2-ethylhexanoate (3GO) as a plasticizer by a kneading roll to obtain a resin composition for a protective layer.

(3) Production of intermediate film for laminated glass

The obtained resin composition for a sound-insulating layer and the obtained resin composition for a protective layer were co-extruded by using a co-extruder, thereby obtaining a 3-layer interlayer (sound-insulating interlayer) for laminated glass having a structure in which a layer a (protective layer) having a thickness of 450 μm and formed from the resin composition for a protective layer, a layer B (sound-insulating layer) having a thickness of 100 μm and formed from the resin composition for a sound-insulating layer, and a layer C (protective layer) having a thickness of 450 μm and formed from the resin composition for a protective layer were sequentially laminated.

(4) Imparting unevenness

As the 1 st step, irregular uneven shapes are transferred to both surfaces of the interlayer film for laminated glass in the following order. First, irregular asperities are applied to the surface of an iron roll by a blasting agent, the iron roll is vertically polished, and further, fine asperities are applied to a flat portion after polishing by a finer blasting agent, whereby a pair of rolls having the same shape with a rough main embossment and a fine sub-embossment is obtained. The pair of rolls was used as a concavo-convex shape transfer device, and random concavo-convex shapes were transferred to both surfaces of the obtained intermediate film for laminated glass. The transfer conditions in this case were 80 ℃ for the interlayer film for laminated glass, 145 ℃ for the roller, 10m/min for the linear velocity, and 10 to 200kN/m for the press line pressure. The surface roughness of the shaped interlayer film for laminated glass was measured to be 16 μm as a ten-point average roughness Rz in accordance with JIS B0601 (1994). The measurement is obtained by data processing of a digital signal measured by a surface roughness measuring instrument (SE 1700 α, manufactured by Kosaka Laboratory ltd.). The measurement direction was perpendicular to the scribe line, and the measurement was performed under the conditions that the cutoff value (Cut of value) was 2.5mm, the reference length was 2.5mm, the evaluation length was 12.5mm, the radius of the tip of the stylus was 2 μm, the tip angle was 60 °, and the measurement speed was 0.5 mm/s.

In the 2 nd step, the surface of the interlayer film for laminated glass is provided with irregularities having a groove shape (linear shape) continuous at the bottom in the following order. A pair of rollers consisting of a metal roller whose surface is polished by a triangular oblique line type grinder and a rubber roller having a JIS hardness of 45-75 are used as a concavo-convex shape transfer device, and the intermediate film for laminated glass to which the irregular concavo-convex shape is transferred in the step 1 is passed through the concavo-convex shape transfer device, thereby imparting the concavo-convex shape in which the concave portions having a groove shape (ruled line shape) continuous at the bottom are arranged in parallel at equal intervals to the surface of the layer A of the intermediate film for laminated glass. The transfer conditions at this time were that the temperature of the interlayer film for laminated glass was set to room temperature, the roll temperature was set to 130 ℃, the linear velocity was set to 10m/min, the film width was set to 1.5m, and the pressing pressure was set to 500 kPa.

Next, the same operation as described above was performed on the surface of the C layer of the interlayer film for laminated glass except that metal rolls having different concave-convex shapes were used, and a concave portion having a continuous groove shape (linear shape) was provided on the bottom portion. At this time, the intersection angle between the recessed portions of the groove shape (linear shape) having continuous bottoms provided on the surface of the layer a and the recessed portions of the groove shape (linear shape) having continuous bottoms provided on the surface of the layer C was set to 10 °.

(5) Measurement of surface roughness of layer A and layer C

The surfaces of the a layer and the C layer of the obtained interlayer film for laminated glass (observation range 20mm × 20mm) were observed using an optical microscope (manufactured by SONIC Corporation, BS-8000III), and after the intervals of the adjacent concave portions were measured, the average value of the shortest distances between the bottommost portions of the adjacent concave portions was calculated, thereby obtaining the intervals of the concave portions. The interval between the recesses on the surface of the A layer was 500 μm, and the interval between the recesses on the surface of the C layer was 750 μm. The average value and the maximum value of the shortest distances are the same.

Further, with respect to the groove depths (Rzg) of the recessed portions on the surfaces of the a layer and the C layer of the obtained interlayer film for laminated glass, the groove depths specified in JIS B-0601(1994) "surface roughness-definition and expression" were calculated based on a reference length of 2.5mm and based on an average line of a roughness curve (a line set so that the sum of squares of deviations from the roughness curve was minimized), and the average value of the groove depths of the measured groove numbers was taken as the groove depth per unit reference length, and the average value at 5 points of the groove depth per unit reference length was taken. The number of grooves in the layer A is 5, and the number of grooves in the layer C is 4. The groove depths (Rzg) of the recessed portions on the surfaces of the layer a and the layer C are obtained by data processing of digital signals measured by a surface roughness measuring instrument (SE 1700 α, manufactured by Kosaka Laboratory ltd.). The measurement was performed under the conditions that the radius of the tip of the stylus was 2 μm, the tip angle was 60 °, and the measurement speed was 0.5 mm/s.

The depth (Rzg) of the recess in the surface of the layer A was 21 μm, and the depth (Rzg) of the recess in the surface of the layer C was 19 μm.

Further, the surfaces of the a layer and the C layer of the obtained interlayer film for laminated glass were measured using a surface roughness measuring instrument (SE 1700 α, manufactured by Kosaka Laboratory ltd.), thereby obtaining a ten-point average roughness (Rz). The ten-point average roughness (Rz) of the surface of the A layer was 51 μm, and the ten-point average roughness (Rz) of the surface of the C layer was 50 μm.

(6) Measurement of unevenness of interface

The obtained interlayer film for laminated glass was cut into a length of 5cm × a width of 5cm, and allowed to stand at 25 ℃ and a humidity of 30% for 2 hours.

A finger is inserted between the layer A and the layer B to peel off at a speed of 10 to 15 cm/s. After the peeling, the sheet was further left to stand at 25 ℃ and 30% humidity for 2 hours. Thereafter, the surface on the B layer side of the peeled A layer was measured by a high precision shape measuring system (manufactured by Keyence Corporation, "KS-1100" front end detection head model "LT-9510 VM") in accordance with JIS B0601(1994), thereby obtaining a ten-point average roughness (Rz). The surface on the B layer side of the peeled A layer had a ten-point average roughness (Rz) of 1.7 μm. The measurement conditions were set such that the stage moving speed was 100.0 μm/s, the measurement pitch on the X-axis was 2.0 μm, and the measurement pitch on the Y-axis was 2.0 μm.

Peeling was also performed by the same method for the B layer and the C layer, and a ten-point average roughness (Rz) of the surface on the B layer side of the peeled C layer was obtained. The surface on the B layer side of the C layer peeled off had a ten-point average roughness (Rz) of 1.9. mu.m.

(examples 2 to 5, comparative example 1)

An interlayer film for laminated glass was produced in the same manner as in example 1, except that the thickness of each layer, the interval between the recesses on the surfaces of the a layer and the C layer, the groove depth (Rzg) of the recesses, the ten-point average roughness (Rz), and the ten-point average roughness (Rz) of the surface on the B layer side of the peeled a layer and the surface on the B layer side of the peeled C layer were as shown in table 1.

In example 2, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 200 kPa.

In example 3, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 400 kPa.

In example 4, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 500 kPa.

In example 5, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 500 kPa.

In comparative example 1, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 200 kPa.

In the measurement of the intervals between the concave portions in examples 2 to 5 and comparative example 1, the average value and the maximum value of the shortest distances between the concave portions were the same.

(examples 6 and 7, comparative example 2)

An interlayer film for laminated glass was produced in the same manner as in example 1, except that the thickness of each layer, the interval between the recesses on the surfaces of the a layer and the C layer, the groove depth (Rzg) of the recesses, the ten-point average roughness (Rz), and the ten-point average roughness (Rz) of the surface on the B layer side of the peeled a layer and the surface on the B layer side of the peeled C layer were changed as shown in table 1.

In example 6, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 700 kPa.

In example 7, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 200 kPa.

In comparative example 2, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 100 kPa.

In the measurement of the intervals between the concave portions in examples 6 and 7 and comparative example 2, the average value and the maximum value of the shortest distances between the concave portions were the same.

Comparative examples 3 and 4

Will be at a discharge pressure of 50X 10⁴Pa a pair of 2 rolls, which were used as an embossing transfer device in a grapefruit peel shape (orange peel shape), from which a sandblasting material composed of alumina (# 36: a condition of 65 μm roughness under saturated conditions) was ejected for sandblasting. The interlayer film for laminated glass obtained in example 1 was passed through the emboss transfer printing apparatus having a grapefruit peel shape (orange peel shape), and embosses having a grapefruit peel shape (orange peel shape) were formed on the surfaces of the layer a and the layer C of the interlayer film for laminated glass.

The transfer conditions in this case were set such that the temperature of the interlayer film for laminated glass was normal temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 500 kPa.

In addition, the interlayer films for laminated glass obtained in comparative examples 3 and 4 were not measured for groove depth (Rzg).

(examples 8 to 10)

An interlayer film for laminated glass was produced in the same manner as in example 1, except that the thickness of each layer, the interval between the recesses on the surfaces of the a layer and the C layer, the groove depth (Rzg) of the recesses, the ten-point average roughness (Rz), and the ten-point average roughness (Rz) of the surface on the B layer side of the peeled a layer and the surface on the B layer side of the peeled C layer were as shown in table 1.

In example 8, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 200 kPa.

In example 9, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the press 23 pressure was 500 kPa.

In example 10, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the pressing pressure was 500 kPa.

In the measurement of the intervals between the concave portions in examples 8 to 10, the average value and the maximum value of the shortest distances between the concave portions were the same.

(examples 11 to 14)

An interlayer film for laminated glass was produced in the same manner as in example 1 except that the acetyl group amount, the butyral group amount, the hydroxyl group amount, and the plasticizer content of the polyvinyl butyral used for the protective layer and the sound-insulating layer were changed as shown in table 1, the thickness of each layer, the interval between the recesses on the surfaces of the a layer and the C layer, the groove depth (Rzg) of the recesses, the ten-point average roughness (Rz) of the surface on the B layer side of the peeled a layer, and the ten-point average roughness (Rz) of the surface on the B layer side of the peeled C layer were changed as shown in table 1, and the transfer conditions for imparting unevenness were changed. The polyvinyl butyral used for the protective layer and the sound insulating layer was obtained by acetalizing polyvinyl alcohol having an average polymerization degree of 1700 with n-butyl aldehyde.

In example 11, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the press line pressure was 200 kPa.

In example 12, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the press line pressure was 500 kPa.

In example 13, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the press line pressure was 500 kPa.

In example 14, the transfer conditions for imparting unevenness were set such that the temperature of the interlayer film for laminated glass was room temperature, the roll temperature was 130 ℃, the linear velocity was 10m/min, the film width was 1.5m, and the press line pressure was 550 kPa.

In the measurement of the intervals between the concave portions in examples 11 to 14, the average value and the maximum value of the shortest distances between the concave portions were the same.

(evaluation)

The interlayer films for laminated glass obtained in examples and comparative examples were evaluated by the following methods.

The results are shown in Table 1. In the table, Bu degree represents the butyraldehyde group amount, OH degree represents the hydroxyl group amount, Ac degree represents the acetyl group amount, and the plasticizer part represents the plasticizer content with respect to 100 parts by mass of the polyvinyl butyral.

(1) Evaluation of air-releasing Property

The obtained interlayer film for laminated glass having irregularities on the surface was preliminarily pressure-bonded by a reduced-pressure degassing method as described below, and then subjected to main pressure bonding to produce a laminated glass.

(vacuum degassing method)

The interlayer film was sandwiched between two transparent glass plates (30 cm in length × 30cm in width × 2.5mm in thickness), the excess was cut off, the laminated glass structure (laminate) thus obtained was moved into a rubber bag, the rubber bag was connected to an air-evacuation pressure reducer, and the laminated glass structure (laminate) was heated while being held under reduced pressure of-60 kPa (16 kPa absolute) for 10 minutes, and then heated so that the temperature (pre-press bonding temperature) of the laminated glass structure (laminate) became 70 ℃. The preliminary pressure bonding was performed under 3 conditions of a degassing start temperature of 40 ℃, 50 ℃ and 60 ℃.

(Main crimping)

The laminated glass structure (laminate) preliminarily pressure-bonded by the above method was placed in an autoclave, held at 140 ℃ and 1300kPa for 10 minutes, and then the temperature was lowered to 50 ℃ and returned to atmospheric pressure, whereby main pressure bonding was terminated to produce a laminated glass.

(baking test of laminated glass)

The obtained laminated glass was heated in an oven at 140 ℃ for 2 hours. Next, after being taken out from the oven and cooled for 3 hours, the appearance of the laminated glass was visually observed. The number of foams (bubbles) generated between the glass plate and the interlayer film for laminated glass was examined for each of 20 sheets, and evaluated as "o" when the number of foams was 5 sheets or less and "x" when the number of foams was 6 sheets or more under all conditions.

(2) Evaluation of optical distortion

A fluorescent lamp (fl32s.d manufactured by Panasonic Corporation) was placed at a position 7m from the observer, and the obtained laminated glass was obliquely disposed at a position 40cm from the observer on a straight line connecting the fluorescent lamp and the observer at an angle of 20 ° with respect to the horizontal plane. Distortion of the fluorescent lamp was observed as "x" when the laminated glass was observed, and as "o" when the laminated glass was not observed.

(3) Evaluation of multiple image Generation

The presence or absence of generation of multiple images was evaluated using 2 kinds of light sources 1 and 2 having different luminances. Here, the light source 1 is a 10W silica bulb (silica bulb) (Kyokko Electric co., Ltd, PS 55E 26110V-10W, total luminous flux 70lm), and is a light source of a normal brightness assumed to be incident on a window glass of an automobile, an airplane, a building, or the like. The light source 2 is a 40W silica bulb (LW 100V38W-W, total luminous flux 440lm, manufactured by Asahi Electric Corporation), and is assumed to have particularly high luminance among light that can be incident on a glass window of an automobile, an aircraft, a building, or the like. The obtained laminated glass was evaluated for the presence or absence of multiple images by a method in accordance with JIS R3212 (2008). As a result, the case where a single image was observed or a double image was generated within 15 minutes when both the light sources 1 and 2 were used was evaluated as "o", the case where a multiple image was generated when the light source 2 was used but a single image was observed or a double image was generated within 15 minutes when the light source 1 was used was evaluated as "o", and the case where a triple image was generated when both the light sources 1 and 2 were used was evaluated as "x".

The actual vehicle mounting angle was measured with the actual vehicle mounting angle set to 30 °. The angle formed by the linear recessed portions provided on the surface of the layer A and the horizontal direction is 5 DEG, and the angle formed by the linear recessed portions provided on the surface of the layer C and the horizontal direction is-5 deg.

The double image within 15 minutes is not an image due to an interlayer film but an image due to glass.

[ Table 1]

[ Table 2]

Industrial applicability

According to the present invention, it is possible to provide an interlayer film for laminated glass in which 2 or more resin layers are laminated, which has excellent degassing properties in a process of manufacturing laminated glass and can prevent the occurrence of multiple images, and a laminated glass including the interlayer film for laminated glass.

Description of the reference numerals

1 a recess selected arbitrarily

2 an arbitrarily selected recess adjacent to a recess

3 arbitrarily selected recess adjacent to a recess

A spacing between recess 1 and recess 2

B spacing between recess 1 and recess 3

10 resin layer

20 a resin layer having a surface with a plurality of concave portions and a plurality of convex portions

21 a surface of the resin layer 20 having a plurality of concave portions and a plurality of convex portions

22 the surface of the resin layer 20 on the side contacting the resin layer 10

30 resin layers.