JPH10231150A - Interlayer for laminated sheet glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an interlayer for laminated sheet glass excellent in blocking resistance during the storage, handling operating efficiency when inserting the interlayer and deaerating properties in a preliminary press-bonding step by forming fine embossments having a specified surface roughness, recessed parts of a specified shape and protruding parts having a specified height and a specified base area on both surfaces of a thermoplastic resin sheet. SOLUTION: This interlayer for laminated sheet glass is obtained by forming embossments composed of fine unevennesses on both surfaces of a thermoplastic resin sheet such as a plasticized polyvinyl acetal. At this time, the surface roughness of the embossments on at least one surface is regulated to 0<Rvk / Rz <=0.25. The Rz (μm) is the average roughness of 10 points specified by DIN4768 and the Rvk is a converted valley depth determined from the Abbot's load curve specified by DIN4762 and 4776. The valley bottom of the recessed parts is a smooth plane and the sum total of the base area of the protruding parts having 20-100μm height is 25-55% based on the base area. The maximum diametral length of the base surface is preferably <=10 times based on the height and the diametral length intersecting the diametral length at right angles is preferably >=0.2 thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlayer film for laminated glass, which has an embossed surface having fine irregularities on its surface and is particularly excellent in deaeration in a pre-compression bonding step.

[0002]

2. Description of the Related Art Laminated glass obtained by sandwiching an interlayer made of a thermoplastic resin sheet such as plasticized polyvinyl butyral between glass plates and bonding them together is widely used for window glasses of automobiles, aircraft, buildings and the like. I have.

[0003] In this kind of laminated glass, usually, an intermediate film is sandwiched between glass plates and handled by passing through a nip roll or put in a rubber bag and suctioned under reduced pressure to remain between the glass plate and the intermediate film. Pre-crimp while removing air,
Next, it is manufactured by heating and pressurizing in an autoclave to perform main pressure bonding.

The interlayer of the laminated glass has adhesiveness,
In addition to good basic performance such as weather resistance, penetration resistance, transparency, etc., interlayer films do not block during storage, and handling workability when sandwiching interlayer films between glass plates is good. Further, in order to eliminate air entrapment, it is required that the deaeration in the pre-compression bonding step be good.

[0005] In order to satisfy such requirements, the intermediate film is formed with embosses having fine irregularities on both surfaces thereof. As the form of the fine unevenness, various uneven patterns composed of a large number of independent convex portions and concave portions corresponding to the convex portions are usually employed (for example, Japanese Patent Publication No. 1-32766).
Reference).

[0006]

However, in the above-mentioned conventional interlayer, blocking resistance during storage, workability and deaeration during the pre-compression bonding step are considerably improved. In the case of manufacturing a laminated glass having a large diameter, a laminated glass having a large curvature, or increasing the productivity of a laminated glass, the degassing property is not sufficiently satisfactory, and there is still room for improvement.

That is, in the conventional intermediate film, it is actually difficult to uniformly form the shape, depth, and height of the unevenness over the whole, and it is formed more or less unevenly, and the degassing property is insufficient. Becomes If the degassing property is insufficient, bubbles remain between the glass plate and the interlayer after the pressure bonding, the adhesiveness becomes insufficient, and a completely transparent laminated glass cannot be obtained. When used under severe conditions (accelerated test at high temperature), foaming occurs.

The present invention solves the above problems,
The purpose thereof is to provide an interlayer film for laminated glass which is excellent in blocking resistance during storage and handling workability when an interlayer film is sandwiched between glass plates, and is particularly excellent in deaeration in a pre-compression bonding step. It is in.

[0009]

An object of the present invention is to provide an interlayer film for laminated glass in which embosses composed of fine irregularities are formed on both surfaces of a thermoplastic resin sheet, and the surface roughness of the emboss on at least one surface is 0 <. Rvk / Rz ≦ 0.25, the valley bottom of the concave portion is formed of a substantially smooth flat surface, and the sum of the base areas of the convex portions whose height of the convex portion is in the range of 20 to 100 μm is 25 of the total base area. This can be achieved by an interlayer film for laminated glass characterized by occupying about 55% (the invention of claim 1).

[0010] Here, Rz (μm) is DIN 4768.
And Rvk is DIN 47
It represents the reduced valley depth (μm) obtained from the Abbott load curves defined in 62 and 4776.

As the thermoplastic resin sheet used in the present invention, a sheet used for a conventional interlayer film of laminated glass is used. Examples include a plasticized polyvinyl acetal resin sheet, a polyurethane-based resin sheet, an ethylene-vinyl acetate-based resin sheet, an ethylene-ethyl acrylate-based resin sheet, and a plasticized vinyl chloride-based resin sheet. These sheets have excellent basic performance required for laminated glass, such as adhesion, weather resistance, penetration resistance, and transparency.

Particularly, a plasticized polyvinyl acetal resin sheet represented by a plasticized polyvinyl butyral resin sheet is preferable. The film thickness of these thermoplastic resin sheets is determined in consideration of the penetration resistance and the like required as a laminated glass, and is approximately the same as that of a conventional interlayer film, and particularly, 0.2 to 2 mm.
It is preferred that

On both sides of the thermoplastic resin sheet, 0 <Rvk / Rz ≦ 0.25 is satisfied, the valley bottom of the concave portion is a substantially smooth flat surface, and the peak height is 20 to 100 μm.
An emboss is formed of fine irregularities in which the sum of the base areas of the respective projections in the range of m occupies 25 to 55% of the total base area.

In order to form such an emboss, in order to obtain an emboss consisting of quantitatively constant fine irregularities,
An embossing roll method using an embossing roll is preferred. As the embossing roll, for example, an embossing roll produced by using an engraving mill (mother mill) and transferring this uneven pattern to a metal roll is preferably used. In addition, an embossing roll produced by an etching method (etching) is preferably used.

The embossed concavo-convex pattern is not particularly limited as long as it satisfies the above-mentioned specific conditions, and may be distributed regularly and regularly or irregularly and irregularly. Further, the heights of the respective convex portions may be all the same or different.

The shape of the projection is not particularly limited as long as it satisfies the above specific conditions. Generally, it consists of cones such as triangular pyramids, quadrangular pyramids and cones, truncated cones such as truncated triangular pyramids, truncated quadrangular pyramids, and truncated cones, and pseudo-pyramids with a mountain-shaped or hemispherical head. An uneven pattern having a large number of convex portions, particularly a large number of convex portions formed of a mountain-shaped or hemispherical pseudo-cone is preferable.

Also, the valley bottom of the concave portion may be formed of a substantially smooth plane, and all the valley bottom planes may be planes of the same level or planes of vertically different levels. Is also good. Further, the plane of each valley bottom may be a horizontal plane, or may be an inclined plane slightly inclined with respect to the horizontal plane.

Further, these embossed concavo-convex patterns are also:
What is necessary is just to satisfy the said specific condition, and it is not specifically limited. Generally, the interval between each convex portion is approximately 10 to 20.
It is preferably in the range of 00 μm, particularly in the range of 200 to 1000 μm. In addition, the height of each convex portion is approximately 5 to 2
It is preferably in the range of 00 μm, particularly preferably in the range of 20 to 100 μm. In addition, the maximum transfer length of the base surface of each projection is
Those having a range of about 30 to 900 μm are preferred.

In the present invention, the Abbott load curve is obtained, for example, by measuring the surface roughness of an embossed thermoplastic resin sheet using a surface roughness meter to obtain a roughness curve as shown in FIG. From this roughness curve, the load length ratio [(bearing ratio tp = material)
ial component (material ra
tio) Mr], for example, as shown in FIG.
This is a curve obtained by expressing the load length ratio on the horizontal axis and the cutting level on the vertical axis, and is a cumulative probability distribution of the surface roughness.

Here, the load length ratio is determined by extracting an evaluation length (lm) from the roughness curve in the direction of the average line, and converting the roughness curve of the extracted portion to a cutting level (profile) parallel to the peak line. Sum of cutting lengths obtained when cutting at section level (load length) (b ₁
+ B ₂ + b _i ... B _n ) to the evaluation length (lm) in percentage. The cutting level is such that the top line of the roughness curve is at a cutting level of 0% and the bottom line of the roughness curve is at a cutting level of 100% (see DIN 4762 and 4776).

The Abbott load curve two-dimensionally represents the average shape of the emboss. For example, as shown in FIG. 3, the position of the cutting line (profile section) is used.
It is represented by a material component (Mr) as a function of the line position and is divided into three regions (Rk, Rpk, Rvk).
Here, Rk (μm) is the central region of roughness, and Rpk (μm)
Is the converted peak height (average height of the peak protruding from the central region), Rvk (μm) represents the converted valley depth (average depth of the valley lowered from the central region), and Mr1 (%) is Material component 1 (ratio of peak), Mr2 (%) is material component 2.
(The ratio of the portion excluding the valley portion).

In order to measure the parameters of the surface roughness (Rz, Rpk, Rvk, Mr1, Mr2, etc.) of the emboss, for example, Feinpuf Perthe, Germany
n Surface roughness meter manufactured by GmbH (trade name: Pertho)
meter S3P) and this Perthometer
S3P specification surface shape analyzer (trade name: SAS-2)
010, manufactured by Meishin Koki Co., Ltd.).

In such an Abbott load curve, R
vk (converted valley depth, that is, the average depth of the valley portion falling from the center region) is an air passage in the pre-compression bonding step between the glass plate and the intermediate film, and air is released during degassing. There is a close relationship with ease. On the other hand, the size and the distribution density of the projections are not only a resistance to the movement of air, but also have a close relationship with the crushability of the emboss during the alignment processing.

Therefore, as a result of various studies, 0 <Rvk / Rz
≤ 0.25, the valley bottom of the concave portion is formed of a substantially smooth flat surface, and the sum of the base areas of the convex portions having a height in the range of 20 to 100 µm occupies 25 to 55% of the total base area. It has been found that the formation of such embossments with fine irregularities provides excellent degassing during pre-compression bonding (the invention of claim 1).

When Rvk / Rz exceeds 0.25, the depth of the concave portion becomes very deep, so that air is easily trapped in this portion during degassing. Is not preferred because it is difficult to form and is locally degassed.

Here, the expression that the valley bottom of the concave portion is a substantially smooth plane means that, for example, in a roughness curve as shown in FIG. 1, the valley bottom has a substantially smooth horizontal plane or inclined plane or a horizontal plane and an inclined plane. Means that a surface in which both are mixed is formed. Here, “substantially” means that the smoothness of the plane (horizontal plane or inclined plane) of each valley bottom is acceptable as long as it is small irregularities or steps up to 5 μm.

[0027] The bottom of the recess does not form a substantially smooth plane, for example, the bottom of the recess has a V-shape, or even if a plane is formed, the plane is substantially If the surface is not smooth, the air interposed between the glass plate and the interlayer film during the pre-compression process receives much resistance at the valley bottom of the concave portion, making it difficult for the air to be smoothly discharged from the concave portion. Temper becomes insufficient.

The sum of the base areas of the projections whose height is in the range of 20 to 100 μm is 25% of the total base area.
If the pressure is less than 1, especially when the curvature of the glass plate becomes large and pressure is locally applied, the convex portion is crushed before the pre-compression and the seal precedes, and air is unevenly distributed in the preceding seal portion. It will accumulate. Conversely, if the sum of the base areas of the projections whose height of the projections is in the range of 20 to 100 μm exceeds 55% of the total base area, the curvature of the glass plate becomes particularly large and the glass plate is locally localized. In the case where a misalignment occurs, the protrusions remain without being crushed after the preliminary press-bonding, resulting in a poor seal. At the time of the final press-bonding, air enters into the autoclave and foaming occurs.

Here, the height and the base area of each projection are determined by observing the cross section and plane of the embossed sheet with an optical microscope, for example, an optical microscope having an observation range of 2.5 mm × 1.8 mm. The height of the part (vertical distance from the base line to the peak) and its basal area can be measured. This base line is determined by a conventional method (a method called a so-called baseline method) representing and connecting lines at the bottoms of the convex portions. The total base area is the total area of the base areas of all the convex portions and the area of the valley bottom plane of the concave portions.

For example, when the valley bottom of each concave portion is a substantially smooth plane and a plane of the same level, the base line of each convex portion has a cutting level 1 in the roughness curve as shown in FIG.
Corresponds to the 00% line. And the base area of each convex part is
The area of the valley bottom plane of each concave portion corresponds to the cut area of each convex portion in the line at the cut level of 100%.
This corresponds to the valley bottom area of each recess at the 0% line.

In particular, in addition to the requirements of the first aspect of the present invention, the maximum transfer length of the base surface of each convex portion having a height of 20 to 100 μm is determined by the height of the convex portion. Of 10
It is preferable that the interlayer film for laminated glass is twice or less (the invention of claim 2). The reason is as follows.

That is, the height of the projection is 20 to 100 μm
If the maximum crossover length of the base surface of each convex portion in the range of 10 exceeds 10 times the height of the convex portion, an extremely protruding convex portion will be included. The raised part is
This is because during pre-compression bonding, the protrusions are less likely to be crushed than other protrusions, remain uncrushed after pre-compression bonding, and the seal becomes defective, and air tends to enter the autoclave during the final compression bonding and foaming is likely to occur. . Here, the maximum transfer length of the base surface means the longest distance among the distances from one end to the other end of the base surface.

[0033] In addition to the requirements according to the first or second aspect of the present invention, in addition to the requirements of the invention of claim 1 or 2, the height of the projections is in the range of 20 to 100 µm and the maximum length of the base surface of each projection orthogonal to the maximum length. However, it is preferable that the interlayer film for laminated glass has a maximum length of 0.2 times or more the maximum cross length of the base surface (the invention of claim 3). The reason is as follows.

That is, the height of the projection is 20 to 100 μm
In the range of less than 0.2 times the maximum transfer length of the base surface of each convex portion in the range and less than 0.2 times the maximum transfer length of the base surface, an extremely elongated mountain-shaped convex portion. The extremely long mountain-shaped projections, as described above, have a large resistance to the movement of air during pre-compression bonding, especially in the case of using a deaeration method using a roll. Because you do.

In the intermediate film of the present invention, it is preferable that both surfaces form the specific surface (the requirements of claims 1, 2 and 3), but only one surface forms the specific surface. On the other hand, the other surface may be formed with a conventional embossment formed of fine irregularities. Thus,
The interlayer film for laminated glass according to the present invention is obtained.

In order to produce a laminated glass using the interlayer film of the present invention, pre-compression bonding and main compression bonding are performed in the same manner as in a conventional method for producing laminated glass. For example, when an intermediate film made of a plasticized polyvinyl butyral resin sheet is used, specifically, pre-compression bonding and main compression bonding are performed as follows.

That is, in the pre-compression bonding, an interlayer is sandwiched between two transparent inorganic glass plates, and the laminate is passed through a nip roll, for example, under the conditions of a pressure of about ^{2 to} 10 kg / cm ² and a temperature of about 50 to 80 ° C. Preliminary pressure bonding while handling and degassing (handling degassing method), or placing the above-mentioned laminate in a rubber bag, connecting the rubber bag to the exhaust system, and approx.
750mmHg vacuum (absolute pressure 360 ~ 10mmH
g) While raising the temperature while reducing the pressure by suction, about 50-100 ° C
(Pressure-reducing degassing method).

Next, the pre-pressed laminate is subjected to a conventional method using an autoclave or a press.
Temperature of about 120-150 ° C, about 10-15 kg / cm ²
This pressure is applied. Thus, a laminated glass is manufactured.

As the glass plate, not only an inorganic glass plate but also an organic glass plate such as a polycarbonate plate and a polymethyl methacrylate plate can be used. The laminated structure of the laminated glass may be not only a three-layer structure of a glass plate / interlayer / glass plate, but also a multilayer structure such as a glass plate / interlayer / glass plate / interlayer / glass plate. it can.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention will be described below. Example 1 An engraving mill (mother mill) for forming an emboss was pressed against the surface of two metal rolls, and the metal roll and the engraving mill were rotated to transfer the concavo-convex pattern of the engraving mill to the metal roll. The arrangement of the concavo-convex pattern was shifted in the axial direction of the metal roll in order, and the concavo-convex pattern of the engraving mill was transferred to the metal roll by the same operation as described above to produce a pair of embossing rolls. In the engraving mill (mother mill), the projections of the concavo-convex pattern were about 100 μm (diameter).
Which were regularly arranged at intervals of 160 μm.

On the other hand, 100 parts by weight of a polyvinyl butyral resin (average degree of polymerization: 1700, residual acetyl group: 1 mol%, butyralization degree: 65 mol%) were mixed with 40 parts by weight of triethylene glycol-di-2-ethyl butyrate as a plasticizer. And 0.2 parts by weight of magnesium acetate as an adhesive force adjuster were mixed, and the mixture was melt-kneaded by an extruder and extruded into a sheet shape from an extrusion die to form a polyvinyl butyral sheet having a thickness of 0.76 mm.

Using the pair of embossing rolls and the polyvinyl butyral sheet, a large number of hemispherical projections are regularly formed on both sides of the polyvinyl butyral sheet, and the valleys of the recesses are made of a smooth flat glass. An intermediate film was manufactured.

Example 2 An engraving mill (mother mill) for forming an emboss was pressed against the surface of two metal rolls, and the metal roll and the engraving mill were rotated to transfer the concavo-convex pattern of the engraving mill to the metal roll. The engraving mill was sequentially shifted in the axial direction of the metal roll by the arrangement unit of the concavo-convex pattern, and the concavo-convex pattern of the engraving mill was transferred to the metal roll by the same operation as described above to produce a pair of embossing rolls. In the engraving mill (mother mill), the projections of the concavo-convex pattern were about 100 μm (diameter).
Used were irregularly arranged at intervals of 20 to 200 μm.

Except for using this pair of embossing rolls, the same procedure as in Example 1 was carried out, and a large number of hemispherical convex portions were formed irregularly on both surfaces of the polyvinyl butyral sheet. Was produced.

Example 3 A pair of embossing rolls having irregularities with a depth of about 40 μm (embossing depth) arranged irregularly on the surfaces of two metal rolls were produced. In this case, a concavo-convex pattern in which the maximum crossover length of the base surface is relatively long with respect to the height of the protrusion is intentionally provided.

Except for using this pair of embossing rolls, the same procedure as in Example 1 was repeated to form a large number of irregular portions on both surfaces of the polyvinyl butyral sheet, and the valley bottoms of the concave portions were substantially flat. Was produced.

Example 4 A pair of emboss rolls having irregularities of about 40 μm (emboss depth) irregularly arranged on the surfaces of two metal rolls were produced by etching. Note that, in this case, a concavo-convex pattern was intentionally provided such that the transfer length orthogonal to the maximum transfer length of the base surface of the convex portion was relatively short.

Except for using this pair of embossing rolls, the same procedure as in Example 1 was carried out to form a large number of irregular portions on both surfaces of the polyvinyl butyral sheet, and the valley bottom of the concave portion was a substantially smooth flat surface. Was produced.

COMPARATIVE EXAMPLE 1 Two metal press plates were used to produce a pair of embossed press plates in which square pyramid-shaped irregularities were regularly formed on the inner surface of each metal press plate.

This pair of embossed press plates and Example 1
By using the polyvinyl butyral sheet described in 1 above, an interlayer film for laminated glass in which square pyramid-shaped irregularities were regularly formed on both surfaces of the polyvinyl butyral sheet was produced by press working.

With respect to the interlayer film for laminated glass obtained in each of the above Examples and Comparative Examples, the parameters of the embossed surface roughness (Rvk / Rz and height 20 to 1) were obtained by the following method.
(The ratio of the sum of the base areas of the respective protrusions of 00 μm to the total base area), the ratio of the maximum transfer length of the base surface of each of the protrusions having a height of 20 to 100 μm to the height of the protrusion, and the height of 20 to 100 μm. 100 μm
(The ratio of the maximum transfer length of the base surface to the maximum transfer length orthogonal to the maximum transfer length of the base surface of each projection). In addition, for each laminated glass using these interlayer films,
A bake test was performed by the following method, and the deaeration in the preliminary pressure bonding step was evaluated. The results are summarized in Table 1.

(1) Measurement of the parameter of the surface roughness of the embossment Feinpuf Perthen GmbH, Germany
Surface roughness meter (trade name: Perthometer)
S3P) and Rz (μm) and Rvk (μ) of the intermediate film using a surface shape analyzer (trade name: SAS-2010, manufactured by Meishin Koki Co., Ltd.) of this Perthometer S3P specification.
m) was measured.

(2) Measurement of the ratio (referred to as area ratio) of the sum of the base areas of the projections having a height of 20 to 100 μm to the total base area (observation range: 2.5 mm × 1.8 mm) ), The height and the base area of each projection of the interlayer were measured on a monitor via a CCD camera and VIDEO GAUGE,
The sum of the base areas and the total base area (2.5 mm × 1.8 m) of each protrusion having a height in the range of 20 to 100 μm.
m) was calculated.

(3) Measurement of the ratio (referred to as height ratio) between the maximum cross length of the base surface of each convex portion having a height of 20 to 100 μm and the height of the convex portion Optical microscope (observation range: 2.5 mm × 1.8 mm), the height of each convex portion of the intermediate film and the maximum transfer length of the base surface were measured on a monitor via a CCD camera and VIDEO GAUGE, and the height was in the range of 20 to 100 μm. Table 1 shows the ratio (height ratio) in which the ratio of the maximum transfer length of each base surface corresponding to the height of a certain convex portion is the largest.

(4) The ratio of the maximum transfer length of the base surface of each projection having a height of 20 to 100 μm, which is orthogonal to the maximum transfer length, and the maximum transfer length of the base surface (referred to as the transfer length ratio). Measurement Using an optical microscope (observation range: 2.5 mm × 1.8 mm), the maximum transfer length of the base surface of each convex portion of the intermediate film and the maximum difference orthogonal to this on a monitor via a CCD camera and VIDEO GAUGE on a monitor. Measurement of the passing length, height 20
With respect to the maximum transfer length of the base surface of each convex portion in the range of 100 μm, the one having the smallest maximum transfer length ratio perpendicular to this (the transfer length ratio) is entered in Table 1. did.

(5) Bake test Preliminary compression was performed by the following method (handling deaeration method and reduced pressure deaeration method), and then final compression was performed to produce a laminated glass.

(A) Handling and deaeration method The interlayer film is made of two transparent float glass plates (length 30 cm ×
We sandwich between 30cm in width X 3mm in thickness and cut off protruding part
Remove the laminate thus obtained in a heating oven,
The temperature of the laminate (preliminary compression temperature) is 60 ° C. and 70 ° C., respectively.
℃, 80 ℃, then nip roll
(Air cylinder pressure 3.5kg / cm ^Two, Linear velocity 1
0 m / min) to perform pre-compression bonding.

(B) Vacuum degassing method The interlayer film is formed of two transparent float glass plates (length 30 cm ×
(Weight 30 cm x thickness 3 mm), cut off the protruding part, transfer the thus obtained laminate into a rubber bag, connect the rubber bag to a suction decompression system, and heat at the outside air heating temperature and simultaneously -600 mmHg. (Absolute pressure 160m
The temperature was maintained for 10 minutes under a reduced pressure of mHg), and the laminate was heated so that the temperature (preliminary pressure bonding temperature) became 60 ° C., 80 ° C., and 100 ° C., respectively, and then returned to the atmospheric pressure to complete the preliminary pressure bonding.

The thus obtained laminate was kept in an autoclave at a temperature of 140 ° C. and a pressure of 13 kg / cm ² for 10 minutes, and then the temperature was lowered to 50 ° C. and returned to the atmospheric pressure, thereby completing the final pressure bonding. Thus, a laminated glass was produced.

The laminated glass was heated in an oven at 140 ° C. for 2 hours, taken out of the oven and cooled for 3 hours, and the number of foams (bubbles) generated in the laminated glass was examined to evaluate the degassing property. The test number was 100 sheets. The smaller the number of foams, the better the deaeration.

[0061]

[Table 1]

[0062]

As described above, in the interlayer film for laminated glass in which the embossment having fine irregularities is formed on both surfaces of the thermoplastic resin sheet, at least one surface of the embossment has a surface roughness of 0 <Rvk / Rz ≦ 0. .25 (Rz is DIN 4
The value specified in 768, Rvk is DIN 4762 and 4
(Value obtained from the Abbott load curve specified in 776)
, The valley bottom of the recess consists of a substantially smooth plane,
By using an intermediate film in which the sum of the base areas of the projections whose height of the projections is in the range of 20 to 100 μm occupies 25 to 55% of the total base area, the blocking property during storage and the interlayer between the glass plates are obtained. In addition to being excellent in handling workability when sandwiching, the air interposed between the glass plate and the intermediate film in the pre-compression bonding step is particularly smoothly discharged and sufficiently deaerated. Therefore, it is possible to obtain a laminated glass having good adhesion between the glass plate and the interlayer and having excellent transparency (the invention of claim 1).

In such an interlayer film for laminated glass, in particular, the maximum cross length of the base surface of each projection having a height in the range of 20 to 100 μm is set to be 1 height of the height of the projection.
0 times or less and / or the height of the projection is 20 to 10
In particular, the pre-press-bonding step is performed by setting the cross-over length orthogonal to the maximum cross-over length of the basal plane of each projection in the range of 0 μm to 0.2 times or more of the maximum cross-over length of the basal plane. Thus, it is possible to obtain an interlayer film for laminated glass which is more excellent in degassing properties (the inventions of claims 2 and 3).

Therefore, when a laminated glass is manufactured using the interlayer film of the present invention, even when a laminated glass having a large area, a laminated glass having a large curvature, or a productivity of a laminated glass is to be increased, the laminated glass can be removed. Is performed sufficiently, the layer of the interlayer film is smoothed well along the surface of the glass plate, and has excellent transparency, especially when used under severe conditions, without foaming and good quality. A laminated glass can be manufactured with good workability.

[Brief description of the drawings]

FIG. 1 shows an example of a roughness curve of an intermediate film made of an embossed sheet.

FIG. 2 shows an example of an Abbott load curve of an intermediate film made of an embossed sheet, and shows a relationship between a cutting level and a load length ratio.

FIG. 3 shows an example of an Abbott load curve of an intermediate film made of an embossed sheet, and shows a relationship between a position of a cutting line and a material component.

Claims (3)

[Claims] 1. An intermediate film for laminated glass having an embossment having fine irregularities formed on both surfaces of a thermoplastic resin sheet, wherein at least one surface has an emboss surface roughness of 0 <.
Rvk / Rz ≦ 0.25, the valley bottom of the concave portion is formed of a substantially smooth flat surface, and the sum of the base areas of the convex portions whose height of the convex portion is in the range of 20 to 100 μm is 25 of the total base area.
An interlayer film for laminated glass, wherein the interlayer film occupies about 55%. Here, Rz (μm) represents the ten-point average roughness specified in DIN 4768, and Rvk represents the converted valley depth (μm) obtained from the Abbott load curves specified in DIN 4762 and 4776. 2. The maximum crossover length of the base surface of each projection having a height of the projections in the range of 20 to 100 μm is not more than 10 times the height of the projections. Item 10. The interlayer film for laminated glass according to Item 1. 3. The maximum length of the base portion of each projection having a height in the range of 20 to 100 μm is orthogonal to the maximum length of the base surface. The interlayer film for laminated glass according to claim 1 or 2, wherein the thickness is twice or more.