JPH1017338A - Intermediate film for laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the intermediate film which is excellent in blocking resistance during storage of the film and in handleability at the time of interposing the film between two glass plates and further, in property with respect to degassing of the film in a preliminary pressure joining process. SOLUTION: In this intermediate film consisting of a thermoplastic resin sheet on each of the both surfaces of which an embossed pattern comprising fine ruggedness is formed, the surface roughness of at least one of the surfaces having their respective embossed pattern is set so as to meet the relational expressions, 0<Rvk /Rz <=0.25 and Mr2 >=90%, wherein Rz is a value specified in DIN(Deutshe Industrie Norm) 4768; and Rvk and Mr2 are values obtained from an Abbot's load curve specified in DIN 4762 and 4776. Particularly, in addition to these conditions, the bearing ratios at 5% and 10% profile section levels are preferably set to <=2% and <=5% respectively, in the Abbots load curve.

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 on which an emboss having fine irregularities is formed.

[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 demands, the intermediate film is usually formed with embosses having fine irregularities on both surfaces thereof. As the form of the fine unevenness, various uneven patterns composed of a number of protrusions and concave portions corresponding to the protrusions, or various uneven patterns formed of a number of convex lines and concave grooves corresponding to the convex lines are disclosed ( For example,
No. 76).

[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 difficult to uniformly form the shape of the unevenness, the depth and the height of the unevenness over the entirety, and the unevenness is more or less uneven, and the deaeration is insufficient. 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-mentioned problems, and its object is to provide excellent blocking resistance during storage and excellent handling workability when an intermediate film is sandwiched between glass plates, and to provide a preliminary press-bonding step. An object of the present invention is to provide an interlayer film for laminated glass having excellent degassing properties.

[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,
This can be achieved by an interlayer film for laminated glass characterized by satisfying Mr2 ≧ 90%.

[0010] Here, Rz (μm) is DIN 4768.
And Rvk is DIN 47
Represents the reduced valley depth (μm) obtained from the Abbott load curves defined in 62 and 4776, and Mr2 represents the material component (%) obtained from the above Abbott load curves.

As the thermoplastic resin sheet used in the present invention, a sheet used for a conventional interlayer film of laminated glass is used. For example, plasticized polyvinyl acetal resin sheet, polyurethane resin sheet, ethylene-
Examples include a vinyl acetate resin sheet, an ethylene-ethyl acrylate resin sheet, and a plasticized vinyl chloride 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 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 is particularly preferably 0.2 to 2 mm.

Then, embosses having fine irregularities satisfying the conditions of 0 <Rvk / Rz ≦ 0.25 and Mr2 ≧ 90% are formed on both surfaces of the thermoplastic resin sheet. In order to form such an emboss, an emboss roll method, a calender roll method, a profile extrusion method, an extrusion lip emboss method using a melt fracture, or the like is employed. In particular, the embossing roll method is suitable for quantitatively obtaining embosses having constant fine irregularities.

The embossed concavo-convex pattern is not particularly limited as long as it satisfies the above specific conditions. In general,
Various fine uneven patterns composed of a large number of protrusions and a large number of concave portions corresponding to these protrusions are formed, and these uneven patterns may be distributed regularly and irregularly, and may be randomly and irregularly. It may be distributed. Further, the heights of the projections may be all the same or different, and the depths of the recesses with respect to the projections may be different even if they are all the same depth. You may.

The shapes of the protrusions and recesses are not particularly limited as long as they satisfy the specific conditions.
In general, pyramids such as triangular pyramids, quadrangular pyramids, and cones, truncated triangular pyramids,
It is composed of truncated cones such as truncated quadrangular pyramids and truncated cones, a number of projections consisting of pseudo cones with a mountain-shaped or hemispherical head, and a number of depressions corresponding to these projections. It is a concave and convex pattern,
In particular, a concavo-convex pattern composed of a number of projections formed of cones, mountain-shaped or hemispherical pseudo-cones, and a number of depressions corresponding to these projections is preferable.

The dimensions of these embossed concavo-convex patterns are not particularly limited as long as they satisfy the above-mentioned specific conditions. Generally, the interval between the protrusions is about 10 to 2
It is preferably in the range of 000 μm, especially in the range of 200 to 1000 μm. The height of the protrusion is generally 5 to 5
It is preferably in the range of 00 μm, especially in the range of 20 to 100 μm. Also, the length of the base of the protrusion is approximately 30 to 9
Those having a range of 00 μm are preferred.

In the present invention, the Abbott load curve is:
By measuring the surface roughness of the embossed sheet using a surface roughness meter, for example, a roughness curve as shown in FIG. 1 is obtained, and a load length ratio [(bearing) is obtained from the roughness curve.
ratio tp = material component
nt (material ratio) Mr], for example, as shown in FIG. 2, this load length ratio is shown on the horizontal axis, and the cutting level is shown on the vertical axis. It is a cumulative probability distribution of roughness.

Here, the load length ratio is obtained by extracting the roughness curve from the roughness curve in the direction of the average line by an evaluation length (lm), and converting the roughness curve of the extracted portion to a cutting level (p) parallel to the peak line.
sum (load length) (b ₁ + b) of the cutting lengths obtained when cutting at the profile section level
₂ + b _i ... B _n ) to the evaluation length (lm) in percentage. The cutting level is set such that the peak line of the roughness curve has a cutting level of 0% and the bottom line of the roughness curve has a cutting level of 100% (DIN 4762 and 47).
76).

The Abbott load curve two-dimensionally represents the average shape of the emboss. As shown in FIG. 3, the position of the cutting line (profile section line) is used.
material as a function of deposition
real component Mr), and is divided into three regions (Rk, Rpk, Rvk). Where R
k (μm) is the central region of the roughness, Rpk (μm) is the converted peak height (the average height of the peak protruding from the central region), R
vk (μm) represents the converted valley depth (the average depth of the valley portion falling from the central region), Mr1 (%) is the material component (ratio of the ridge portion), and Mr2 (%) is the material component (the valley portion) (The ratio of the portion excluding).

In order to measure the surface roughness parameters (Rz, Rvk, Mr2, etc.) of the emboss, for example, a surface roughness meter (trade name: Perthometer S manufactured by Feinpuf Perthen GmbH, Germany) is used.
3P) and a surface shape analyzer of this Perthometer S3P specification (trade name: SAS-2010, manufactured by Meishin Koki Co., Ltd.) can be easily measured.

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. Further, Mr2 (the material component, that is, the ratio of the portion excluding the valley portion) is not only a resistance to the movement of air, but also has a close relationship with the crushability of the emboss during the joining process.

Therefore, as a result of various studies, 0 <Rvk / Rz
It was found that, when ≦ 0.25 and Mr2 ≧ 90%, the degassing property at the time of preliminary pressure bonding was excellent. 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, and Rvk / Rz becomes large.
An emboss of z = 0 is not preferred because it is actually difficult to form and is locally degassed. On the other hand, when Mr2 is less than 90%, the width of the concave portion becomes very wide, so that a large amount of air tends to remain in this portion, and the convex portion is easily crushed before reaching the pre-crimping condition. Also, the deaeration in the pre-compression bonding step becomes insufficient.

In particular, in addition to the above conditions, in the Abbott load curve, the load length ratio at a cutting level of 5% is 2%.
Hereinafter, it is preferable that the load length ratio at a cutting level of 10% is 5% or less. The reason is as follows.

That is, when the interlayer is sandwiched between the glass plates, there is a problem of slipperiness between the glass plate and the interlayer, which is closely related to the contact area between the glass plate and the interlayer.
If the load length ratio at a cutting level of 5% is 2% or less, the slip between the glass plate and the interlayer is improved, and operations such as positioning when the interlayer is sandwiched between the glass plates are facilitated. I found it. If the load length ratio at a cutting level of 5% exceeds 2%, the contact area between the glass and the interlayer increases, and the slip between the glass plate and the interlayer decreases.

On the other hand, the blocking between the interlayer films depends on the number of interlayer films stacked during storage, but usually the interlayer film only needs to take into account its own weight of 500 to 1000 sheets. If the load length ratio at a cutting level of 10% is 5% or less, the blocking resistance between the interlayers is improved, and the handling operation during storage and when the interlayer is sandwiched between glass plates is facilitated. I found it. Cutting level 10%
When the load length ratio in the above exceeds 5%, the contact area between the intermediate films becomes large, and the blocking resistance of the intermediate film decreases.

In the intermediate film of the present invention, it is preferable that both surfaces have the above-mentioned specific surface roughness, but only one surface has the above-mentioned specific surface roughness and the other surface has the conventional surface roughness. May be formed with an embossment formed of fine irregularities. Thus, the interlayer film for laminated glass of 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 intermediate film is sandwiched between two transparent inorganic glass plates, and the laminate is passed through a nip roll, for example, at 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 under the conditions (handling degassing method), or placing the above-mentioned laminate in a rubber bag, connecting the rubber bag to the exhaust system, and applying about -400 to -7
A method (vacuum degassing method) is adopted in which the temperature is increased while suction and pressure is reduced to a vacuum of 50 mmHg (absolute pressure: 360 to 10 mmHg), and pre-compression bonding is performed at about 50 to 100 ° C.

Next, the pre-pressed laminate is subjected to a conventional method using an autoclave or a press.
The final compression bonding is performed at a temperature of about 120 to 150 ° C. and a pressure of about 10 to 15 kg / cm ² . Thus, a laminated glass is manufactured.

As the above 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.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention will be described below. Example 1 A surface of a metal roll was subjected to blasting using an alumina-based abrasive, and then lapping was performed by vertical grinding, thereby producing an embossed roll having irregularly shaped mountain-shaped irregularities.

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.

By using the embossing roll and the polyvinyl butyral sheet, irregularities of mountain shape are irregularly formed on both surfaces of the polyvinyl butyral sheet, and embosses having fine irregularities satisfying the requirements of the invention of claim 2 are formed. An interlayer for laminated glass was manufactured.

Example 2 An engraving mill (mother mill) for forming an emboss was pressed against the surface of a metal roll, and the metal roll and the engraving mill were rotated to transfer the concavo-convex pattern of the engraving mill to the metal roll. In the same operation as above, the embossing roll is transferred to the metal roll, and the embossing roll in which hemispherical irregularities are formed irregularly is shifted in the axial direction of the metal roll in order of the arrangement unit of the uneven pattern. Produced.

Other than using this embossing roll,
In the same manner as in Example 1, an interlayer film for laminated glass in which hemispherical irregularities are irregularly formed on both surfaces of the polyvinyl butyral sheet and embosses formed of fine irregularities satisfying the requirements of the invention of Claim 2 are formed. Manufactured.

Example 3 An engraving mill (mother mill) for forming an emboss was pressed against the surface of a metal roll, and the metal roll and the engraving mill were rotated to transfer the concavo-convex pattern of the engraving mill to the metal roll. By shifting in the axial direction of the metal roll in order of the arrangement unit of the concave and convex pattern, the concave and convex pattern of the engraving mill is transferred to the metal roll by the same operation as above, and the embossing roll in which hemispherical irregularities are regularly formed. Produced.

Other than using this embossing roll,
In the same manner as in Example 1, an interlayer film for laminated glass in which hemispherical irregularities are regularly formed on both surfaces of the polyvinyl butyral sheet and embosses formed of fine irregularities satisfying the requirements of the invention of claim 1 is obtained. Manufactured.

COMPARATIVE EXAMPLE 1 An engraving mill (mother mill) for embossing was pressed against the surface of a metal roll, and the metal roll and the engraving mill were rotated to transfer the concavo-convex pattern of the engraving mill to the metal roll. In the same manner as above, the embossing mill was transferred to the metal roll by the same operation as described above to produce an embossing roll in which hemispherical irregularities were regularly formed. did.

Other than using this embossing roll,
In the same manner as in Example 1, for a laminated glass in which hemispherical irregularities are irregularly formed on both surfaces of a polyvinyl butyral sheet, and embosses formed of fine irregularities that do not satisfy the requirements of the inventions of Claims 1 and 2. An intermediate film was manufactured.

Comparative Example 2 The surface of a metal roll was subjected to blasting using an alumina-based abrasive, and then lapping was performed by vertical grinding to produce an embossed roll in which mountain-shaped irregularities were formed irregularly. .

Other than using this embossing roll,
In the same manner as in Example 1, for a laminated glass in which hemispherical irregularities are irregularly formed on both surfaces of a polyvinyl butyral sheet, and embosses formed of fine irregularities that do not satisfy the requirements of the inventions of Claims 1 and 2. An intermediate film was manufactured.

Comparative Example 3 Using two metal press plates, an embossed press plate having square pyramid-shaped irregularities regularly formed on the inner surface of each metal press plate was produced.

Using the embossed press plate and the polyvinyl butyral sheet described in Example 1, square pyramid irregularities are regularly formed on both surfaces of the polyvinyl butyral sheet by press working. An interlayer film for laminated glass having an embossment formed of fine irregularities not meeting the requirements was manufactured.

With respect to the interlayer film for laminated glass obtained in each of the above Examples and Comparative Examples, the parameters of the surface roughness of the emboss (Rz, Rvk, Mr2 and the ratio of the load length), the film slip were obtained by the following methods. A test and a blocking resistance test were performed to evaluate the handling workability and self-adhesion of the interlayer film. Furthermore, 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 Tables 1 and 2.

(1) Emboss Surface Roughness Parameter
Measurement Feinpuf Perthen GmbH, Germany
Surface roughness meter (trade name: Perthometer)
S3P) and an Rz (μm), Rvk (μm
), Mr2 (%)), the load length ratio (%) at a cutting level of 5%, and the load length ratio (%) at a cutting level of 10%.

(2) Membrane Slip Test The intermediate film was cut into 50 cm × 50 cm, placed horizontally on a glass plate having a smooth surface (50 cm long × 50 cm wide), and placed on the glass plate for sliding (10 cm long). × width 10cm × thickness 2.5
mm) was placed, and after 30 seconds, the sliding glass plate was pulled horizontally through a spring balance, and its maximum frictional resistance (g) was measured from the reading of the spring balance (number of repetitions: 5). The measurement was performed under the conditions of a temperature of 20 ° C. and a humidity of 40% RH. The smaller the maximum frictional resistance, the better the slip between the glass plate and the interlayer, the easier the alignment between the glass plate and the interlayer, etc.,
Excellent handling workability.

(3) Blocking resistance test The intermediate film was cut into 15 cm × 15 cm, two of them were superimposed, a 13 kg weight was placed thereon, and was left at room temperature for 24 hours. 180 minutes per minute
A peel test was performed to measure the peel force (g) (5 repetitions). As the peel force is smaller, the interlayer films are less likely to adhere to each other, and the handling workability during storage or when the interlayer film is sandwiched between glass plates is excellent.

(4) Bake test Preliminary pressure bonding was performed by the following method (handling degassing method and reduced pressure degassing method), and then main pressure bonding was performed to produce a laminated glass.

(A) Handling deaeration method The interlayer film is sandwiched between two transparent float glass plates (30 cm long × 30 cm wide × 3 mm thick), and the protruding portion is cut out. In the heating oven, the temperature of the laminate (preliminary compression temperature) is 60 ° C., 70 ° C., respectively.
Heat to 80 ° C, then nip roll (air cylinder pressure 3.5 kg / cm ² , linear velocity 10m /
Min) to perform pre-compression bonding.

(B) Vacuum Degassing Method The interlayer film is sandwiched between two transparent float glass plates (length 30 cm × width 30 cm × thickness 3 mm), and the protruding portion is cut out. It is transferred into a rubber bag, and the rubber bag is connected to a suction decompression system, heated at the outside air heating temperature and kept at the same time under reduced pressure of -600 mmHg (absolute pressure 160 mmHg) for 10 minutes. Heating was performed to 60 ° C., 80 ° C., and 100 ° C., and thereafter, the pressure was returned to the atmospheric pressure, and the preliminary pressure bonding was completed.

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 the pressure was returned to atmospheric pressure. Upon completion, 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.

[0053]

[Table 1]

[0054]

[Table 2]

[0055]

As described above, in the interlayer film for laminated glass in which the embossment composed of fine irregularities is formed on both surfaces of the thermoplastic resin sheet, at least one surface of the embossed surface roughness is 0 <Rvk / Rz ≦ 0. .25, Mr2 ≧ 90% (R
z is a value specified in DIN 4768, Rvk and Mr2 are values obtained from an Abbott load curve specified in DIN 4762 and 4776) to prevent blocking during storage and to prevent an interlayer film from being sandwiched between glass plates. In addition to the excellent workability of air handling, the air interposed between the glass plate and the interlayer in the pre-compression bonding process is smoothly discharged,
It can be sufficiently degassed. 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, particularly, in the Abbott load curve, the cutting level is 5%.
By setting the load length ratio at 2% or less and the load length ratio at a cutting level of 10% to 5% or less, the blocking property during storage and the handling workability when sandwiching the interlayer between glass plates are improved. It is possible to obtain an interlayer film for laminated glass which is more excellent and has excellent deaeration in the preliminary pressure bonding step (the invention of claim 2).

Therefore, when a laminated glass is manufactured using the interlayer film of the present invention, even if a laminated glass having a large area, a laminated glass having a large curvature, or a productivity of the 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 (2)

[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 <.
An interlayer film for laminated glass, wherein Rvk / Rz ≦ 0.25 and Mr2 ≧ 90% are satisfied. Here, Rz (μm)
Represents the ten-point average roughness defined in DIN 4768,
Rvk represents the reduced valley depth (μm) obtained from the Abbott load curves specified in DIN 4762 and 4776,
Mr2 represents a material component (%) obtained from the above Abbott load curve. 2. The Abbott load curve according to claim 1, wherein a load length ratio at a cutting level of 5% is 2% or less, and a load length ratio at a cutting level of 10% is 5% or less.
The interlayer film for a laminated glass as described above.