JPH1135348A - Production of intermediate film for laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an intermediate film for preventing the blocking of multilayer resin films with each other, capable of attaining excellent workability or deaerating property at the time of being laminated on a glass plate and free from the generation of optical stress by applying many fine embosses at a specific linear velocity on the surface of the multilayer resin film specified in the film thickness of an outermost layer. SOLUTION: Many fine embosses preferably having 30-1000 μm base diameter or base length and 100-1000 μm pitch is applied with an embossing roll preferably having 20-60 μm surface roughness at 1-20 m/min liner velocity, which is a passing speed of the multilayer resin layer passing through the embossing roll, at least on one surface of the multilayer resin film (e.g. a three layer resin film of polyvinyl butyral resin film/vinyl chloride-ethylene-glycidyl methacrylate film/polyvinyl butyral resin film) having 45-720 μm thickness of the outermost layer and, for example, of 0.1-2 mm total film thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an interlayer film for laminated glass.

[0002]

2. Description of the Related Art Conventionally, between two transparent glass plates,
A laminated glass in which an adhesive resin film (hereinafter referred to as an intermediate film) typified by plasticized polyvinyl butyral resin is sandwiched, has a large strength and is hard to break, and even in the case of a broken glass, a fragile piece is hard to be scattered. As a material, for example, it has been widely used for window glasses of automobiles, aircrafts, and buildings. In such a laminated glass, an interlayer film represented by a plasticized polyvinyl butyral resin is inserted between two transparent glass plates, and the obtained laminate is pre-pressed to remove gas such as air remaining between the layers. After deaeration, the laminate is completely pressure-bonded to completely adhere the laminate, thereby producing the laminate.

The above-mentioned interlayer film for laminated glass is stored by winding a long sheet. However, the so-called blocking phenomenon in which the wound interlayer films are not adhered to each other during storage, that is, a so-called blocking phenomenon does not occur. It is required that the workability at the time of weighing the substrate and the intermediate film be good, and that the deaeration in the pre-compression bonding step be good. In particular, the deaeration during pre-pressing affects the quality of the laminated glass.If the deaeration is insufficient, the resulting laminated glass will have poor light transmission, or if accelerated tests by exposure to ultraviolet light will cause bubbles to form. May occur.

[0004] The overall performance of the interlayer film for laminated glass including the above-mentioned degassing properties depends on the type of thermoplastic resin such as plasticized polyvinyl butyral resin and the physical properties such as viscoelasticity. When the physical properties are fixed, the surface shape of the interlayer film is a major factor in determining its overall performance.

[0005] In particular, it is known that the formation of a large number of fine irregularities called embossments on the surface of an intermediate film is effective in preventing the above-mentioned intermediate films from blocking, workability, degassing, and the like. Is used on the surface. Examples of the form of the emboss include, for example, those in which irregularities having random sizes and shapes are formed, and those in which a large number of lattice-shaped grooves are formed.

As an intermediate film having such an embossed surface, for example, an embossed film having a specific arrangement direction formed on the front and back surfaces of the intermediate film (Japanese Patent Laid-Open No. 6-1279).
No. 83, Japanese Unexamined Patent Publication No. 5-294679) and the like, with respect to prevention of a blocking phenomenon between interlayer films, improvement in workability when weighing a glass plate and an interlayer film, and deaeration in a pre-compression bonding step. The effect has been recognized.

On the other hand, in recent years, the use of laminated glass has been diversified, and the added value of laminated glass, such as decorativeness, heat insulation, and lamination, has been widely required to be improved. For this reason, it is difficult to satisfy all the required items only with a single-layer intermediate film composed of a single resin film, and instead, a multilayer intermediate film composed of a multilayer resin film has attracted attention. For example, Japanese Patent Application Laid-Open No. 4-254444 proposes an intermediate film composed of at least two resin films, which is formed by laminating two types of plasticized polyvinyl acetal resin films.

[0008]

However, when the above-mentioned multilayer interlayer having an embossed surface to prevent blocking, improve workability or improve deaeration is used for laminated glass, optical distortion often occurs. However, this causes a phenomenon that the image to be seen through is distorted.

The present inventors examined the relationship between the emboss and the optical distortion of the above-mentioned multilayer intermediate film, and found that when the outermost layer of the multilayer intermediate film had a thickness of 720 μm or less, it was applied to the resin film of the outermost layer. In some cases, the influence of embossing is not limited to the outermost layer, but also affects the interface between the second and subsequent resin layers constituting the multilayer intermediate film. In such a case, fine deformation of the unevenness according to the embossing may occur. In the laminated glass using such a multilayer interlayer, the transmitted light is complicatedly refracted by the deformation of the fine irregularities generated at the interface between the second and subsequent resin layers, and the optically The inventors have found that distortion has occurred, and have conducted intensive research on an embossing method that does not cause optical distortion of the multilayer interlayer film, thereby completing the present invention.

[0010] The present invention has been made in view of the above-mentioned facts, and has as its object to prevent blocking between interlayer films, and furthermore, work for weighing a glass plate and an interlayer film. It is an object of the present invention to provide a method for producing a laminated glass interlayer having good properties and degassing properties, and free from optical distortion.

[0011]

According to the present invention, there is provided a method for manufacturing a laminated glass intermediate film comprising a multilayer resin film having an outermost layer having a thickness of 45 to 720 μm, wherein at least one surface of the multilayer resin film has a linear velocity of 1 to 50 μm. A gist of the present invention is a method for manufacturing a laminated glass interlayer, in which a large number of fine embossings are applied at 20 m / min.

The resin used for the multilayer resin film in the present invention is:
The material is not particularly limited as long as it can form an optically uniform transparent resin film having good adhesiveness with a glass plate or the like to be used, for example, plastics conventionally used for laminated glass Polyvinyl butyral-based resin,
Examples thereof include a vinyl chloride resin, an ethylene-vinyl acetate copolymer resin, and a urethane resin. To these resins, if necessary, additives such as an ultraviolet absorber, an antioxidant, an adhesion regulator, and a coloring agent may be added, or the resin film may be added with these additives. Good.

Each of the resin films made of the above-mentioned resins or the resin films to which the above-mentioned additives are adhered has weather resistance, penetration resistance, scattering prevention of glass shards, transparency, and optical properties that hardly cause optical distortion. The basic performance required for an interlayer film for laminated glass, such as homogeneity, is excellent.

The number of laminated layers of the multilayer resin film used in the present invention is not particularly limited as long as it is two or more.
The outermost layer of the multilayer resin film has a thickness of 45 to 720 μm.
m. When the thickness of the outermost layer is less than 45 μm, the thickness is too small, so that a large molding distortion occurs in the resin film at the time of molding and lamination with the thick intermediate layer,
This may remain as optical distortion and deteriorate the transparency, and if the thickness exceeds 720 μm, the gap between the thickness of the intermediate layer and the intermediate layer increases, so that the same molding distortion as described above occurs at the time of lamination and the transparency is deteriorated. There is a risk.

The number and thickness of the resin films constituting the intermediate layer of the multilayer resin film are not particularly limited, and the thickness of the multilayer resin film is appropriately set according to the use as the intermediate film. It is generally 0.1 to
2 mm.

The bottom diameter or bottom side length, interval (pitch), etc. of the emboss applied to the multilayer resin film are determined by the air accumulation limit and the adhesion (deaeration) when the glass plate and the intermediate film are weighed. It is appropriately set in consideration of appropriate slipperiness between the glass plate and the intermediate film (workability and anti-blocking property during storage). For example, preferably, the bottom diameter or the base length of the emboss is 30 to 900 μm. , Pitch is 100-1000
μm.

In the present invention, the height or depth (hereinafter referred to as surface roughness) of the surface unevenness of the embossing roll for embossing the multilayer resin film is preferably 20 to 6.
0 μm. If the surface roughness is less than 20 μm, the above-mentioned embossing effect cannot be sufficiently obtained. If the surface roughness exceeds 60 μm, the effect of the emboss applied to the outermost resin film of the multilayer resin film does not stop at the outermost layer. It may also affect the interface of each resin layer after the layer, as described above fine deformation of the unevenness according to the emboss occurs at the interface,
In a laminated glass using such a multilayer intermediate film, there is a possibility that transmitted light is refracted in a complicated manner due to the deformation of fine irregularities generated at the interface between the second and subsequent resin layers, causing optical distortion. .

The surface roughness of the embossing roll is determined according to JIS
In accordance with B0601, it is represented by 10-point average roughness,
In the part extracted by the reference length from the cross-sectional curve, the average value of the highest to fifth peak heights measured in the direction of the vertical magnification from the straight line parallel to the average line and not crossing the cross-sectional curve and It is calculated as the difference from the average value of the altitude of the valley bottom up to the fifth.

In the present invention, the linear velocity at the time of embossing is limited to 1 to 20 m / min. If the linear velocity is less than 1 m / min, the influence of the emboss applied to the outermost resin film of the multilayer resin film may not stop at the outermost layer but also affect the interface between the second and subsequent resin layers. As described above, fine deformation of the unevenness according to the emboss occurs at the interface, and the laminated glass using such a multilayer interlayer film occurs at the interface between the second and subsequent resin layers. The transmitted light is refracted intricately by the deformation of minute irregularities,
There is a possibility that optical distortion occurs, and if it exceeds 20 m / min, the above-mentioned emboss effect cannot be sufficiently obtained.

The linear velocity refers to the speed at which the multilayer resin film passes through an embossing roll for embossing, and is determined by the roll diameter and the number of rotations.

The factors involved in the embossing of the multilayer resin film include the temperature of the multilayer resin film and the surface temperature of the embossing roll. These temperatures depend on the type of resin used in the multilayer resin film and the outermost layer. Is appropriately set depending on the thickness of the resin film of, for example, in the case of plasticized polyvinyl butyral resin, preferably the temperature of the resin film is 100 to 120
° C and the surface temperature of the embossing roll are set to 120 to 130 ° C, but the present invention is not particularly limited to these temperatures.

The pressing pressure of the embossing roll is preferably, for example, 3 to 5 in a linear pressure when the multilayer resin film is mainly composed of a plasticized polyvinyl butyral resin.
It is 12 kgf / cm.

In order to manufacture a laminated glass using the interlayer film for a laminated glass thus obtained, for example,
The intermediate film is sandwiched between two transparent inorganic glass plates or an organic glass plate such as a highly rigid polycarbonate plate and a polymethyl methacrylate plate and laminated in a sandwich form. While being pre-pressed at about 70 to 110 ° C., and then in an autoclave or using a press molding machine, for example, when the multilayer resin film is mainly composed of plasticized polyvinyl butyral resin, preferably about 120 ~
The final pressure bonding is performed at a temperature of 150 ° C. and a pressure of about 10 to 15 kg / cm ² .

In the method for producing an interlayer film for laminated glass of the present invention, as described above, a large number of fine embossments are applied at a linear velocity of 1 to 20 m / min. Even if it is an interlayer film for laminated glass composed of a multilayer resin film having a thickness of 45 to 720 μm, the distance between each resin film of the multilayer resin film,
Above all, it is possible to suppress the occurrence of optical distortion due to minute disturbance of the resin in the interface between the outermost layer and the second layer and the resin in the resin layer,
In addition, a large number of fine embosses applied to the surface of the outermost resin film can sufficiently exhibit an embossing effect such as an anti-blocking property between work pieces, workability, and degassing property.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to Examples of the present invention, but the present invention is not limited to these Examples.

[Preparation of Each Resin Film] Resin film A: polyvinyl butyral resin (polymerization degree 170
0, residual acetic acid group 99 mol%, butyralization degree 66 mol%, in Table 1, abbreviated as PVB. ) 100 parts by weight and 40 parts by weight of a plasticizer (triethylene glycol di-2-ethyl butyrate) were sufficiently melted and kneaded with a mixing roll, and then press-molded, and a resin film having each film thickness shown in Table 1 was obtained. A was obtained.

Resin film B: vinyl chloride resin (vinyl chloride-ethylene-glycidyl methacrylate copolymer, Table 1)
Medium is abbreviated as PVC. ) 100 parts by weight and a plasticizer (2
-Ethylhexyl phthalate) was sufficiently melt-kneaded with a mixing roll and press-molded.
As a result, a resin film B having each thickness shown in FIG.

Resin film C: polyurethane resin (4,4-
Copolymer of diisocyanate dicyclohexylmethane and polytetramethylene glycol, abbreviated as PU in Table 1. ) 100 parts by weight were sufficiently melt-kneaded with a mixing roll and then press-molded to form a resin film C having a thickness of 280 μm.
I got

(Examples 1 to 3 and Comparative Examples 1 and 2) Three layers of the resin films A to C were superimposed on each other in the order shown in the column of the lamination structure of the intermediate film in Table 1 and heated by a press molding machine. The multilayer resin film having the thickness shown in Table 1 as a total thickness of the intermediate film was obtained by pressing and integrating. Next, using an embossing roll having a roll surface roughness of 30 μm, the obtained multilayer resin film was embossed at a pressing linear pressure of 8 kgf / cm and an embossing linear velocity shown in Table 1 to form a multilayer interlayer film for laminated glass. Manufactured.

In order to evaluate the performance of the multilayer interlayer films for laminated glass obtained in Examples 1 to 3 and Comparative Examples 1 and 2, transparent float glass (length 30 cm × 30 cm) was placed on both sides of each multilayer interlayer film for laminated glass. (30 cm wide x 3 mm thick), sandwiched and laminated in a sandwich shape, placed in a rubber bag for lamination, degassed for 20 minutes at a vacuum of 20 torr, and kept at 90 ° C. Hold for a minute and vacuum press. The laminate preliminarily pressed in this way was put into an autoclave at 135 ° C. under a pressure of 12 kg.
/ Cm ² for 20 minutes to obtain a laminated glass.

About the obtained laminated glass,
Optical distortion and overall evaluation were tested by the methods shown below. The test results are shown in Table 1.

1. Deaeration: Observed visually for the occurrence of air bubbles in the obtained laminated glass and the laminated glass after irradiation for 1000 hours with a sunshine weatherometer.
Evaluation was made in two stages: one in which no air bubbles were generated, and X: one in which air bubbles were generated.

2. Optical distortion: Applying the principle of the CCD of a video camera, magnify the optical distortion of the laminated glass, project a white / black pattern on the screen, classify the appearance of the white / black pattern into five levels, and 0: completely No white / black pattern appears, 5: White / black pattern appears about 5% of the screen (appears to be slightly distorted of the perspective image by visual inspection), 2, 3, 4 : Based on the in-house standard in which the state of pattern 5 and the state of pattern 0 were divided into three to form a white / black pattern, patterns 0 to 2 were evaluated as ○, and pattern 5 was evaluated as ×. . In this test, there was no sample corresponding to patterns 3 and 4.

3. Comprehensive evaluation: All two items were evaluated comprehensively taking into account workability during the production of laminated glass.

[0035]

[Table 1]

[0036]

The method for manufacturing an interlayer film for laminated glass according to the present invention is configured as described above, so that the occurrence of optical distortion due to minute disturbance of the resin between the resin films of the multilayer resin film is suppressed. And a large number of fine embossments applied to the surface of the outermost resin film can sufficiently exert an embossing effect such as anti-blocking property between interlayer films, workability and degassing property. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 33/00 B32B 33/00

Claims (1)

[Claims] 1. A method of manufacturing an interlayer film for laminated glass comprising a multilayer resin film having an outermost layer having a thickness of 45 to 720 μm, wherein at least one surface of the multilayer resin film has a linear velocity of 1 to
A method for producing an interlayer film for laminated glass, wherein a large number of fine embossings are applied at 20 m / min.