JPH0532434A - Production of intermediate membrane for light-scattering laminated glass and production of light-scattering laminated glass - Google Patents

Abstract

PURPOSE:To provide a method for production of an intermediate membrane for a light-scattering laminated glass and a method for production of a laminated glass by recycling a disused laminated glass by a relatively simple process. CONSTITUTION:The method for production of an intermediate membrane for a light-scattering laminated glass includes a process for crushing a laminated glass composed of two sheets of transparent base plates 1 and 1 and a thermoplastic resin intermediate membrane 2 sandwiched between them, a process for obtaining a resin composition containing dispersed particles 1b derived from the transparent base plates by kneading the transparent base plate 1 fragment 1a-adhering intermediate membrane 2 and a process for forming the resultant resin composition. The resultant intermediate membrane 2 shows light-scattering properties since the particles 1b of the transparent base plates are dispersed in the intermediate membrane 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an intermediate film used for laminated glass for vehicles or constructions, and a method for producing laminated glass using the intermediate film.
More specifically, the present invention relates to a method for manufacturing an interlayer film and a method for manufacturing laminated glass that recycle unnecessary laminated glass.

[0002]

2. Description of the Related Art Laminated glass for passenger cars or construction is formed by inserting an intermediate adhesive layer between two glass sheets and adhering the two glass sheets with the intermediate adhesive layer.
As such an intermediate adhesive layer, an intermediate film made of polyvinyl butyral resin is generally used.

[0003] By the way, the laminated glass, which has become unnecessary due to the deterioration of its commercial value such as a defective appearance or a different size, has conventionally been disposed of by landfilling or the like. However, in recent years, recycling of products has been screaming worldwide due to environmental problems, and the present inventor has conducted various studies for recycling the laminated glass.

For example, it is conceivable to collect unnecessary laminated glass from the market, separate the plate glass and the intermediate film by a method such as mechanical or heating, and use each. However, in such a method, if a small amount of the interlayer film component remains at the interface with the interlayer film of the plate glass, the translucency of the laminated glass is deteriorated, so that the translucency of the entire laminated glass varies. Cause Also,
For example, in the method of mechanically separating the interlayer film and the plate glass, since the adhesive strength between the interlayer film and the plate glass is strong and the impact strength of the plate glass itself is relatively low, it is not possible to employ this method commercially. Can not.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its object is to:
It is an object of the present invention to provide a method for producing an intermediate film for diffused laminated glass by recycling unnecessary laminated glass by a relatively simple method. Still another object of the present invention is to provide a method for producing a diffused laminated glass using such an intermediate film.

[0006]

A method for manufacturing an intermediate film for diffused laminated glass according to the present invention is a laminated glass formed by disposing an intermediate film made of a thermoplastic resin between two translucent substrates. A step of crushing, a step of kneading the intermediate film to which the fragments of the transparent substrate are attached to obtain a resin composition in which particles of the transparent substrate are dispersed, and a step of molding the resin composition, Thereby, the above object is achieved.

The method for producing a diffused laminated glass of the present invention comprises a step of crushing a laminated glass formed by disposing an interlayer film made of a thermoplastic resin between two translucent substrates,
A step of kneading an intermediate film on which fragments of a transparent substrate are attached to obtain a resin composition in which particles of the transparent substrate are dispersed, a step of molding the resin composition to form an intermediate film for diffused laminated glass And a step of arranging the intermediate film between two light-transmissive substrates and press-bonding the same, thereby achieving the above object.

The present invention will be described below with reference to the drawings.

The laminated glass used in the manufacturing method of the present invention is a so-called safety glass which is commercially available for automobiles or constructions. As shown in FIG. The intermediate film 2 made of a thermoplastic resin is disposed between the flexible substrates 1 and 1. The translucent substrate 1 is usually transparent or colored plate glass, but may be a plastic plate, or may have a heat ray reflective layer such as a metal layer formed on the inner surface thereof. The two transparent substrates 1 and 1 may be of the same type or of different types. The thickness and size of the translucent substrate 1 are not limited, and may be generally commercially available and typically about 1 to 20 mm.

As the thermoplastic resin forming the intermediate film 2, a conventionally known resin used for this type of laminated glass can be used. For example, α-olefin-vinyl ester copolymer and its modified product, ethylene-acrylic acid copolymer, modified ethylene copolymer, acrylic resin, block copolymer rubber, polyurethane, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer. Examples thereof include polymers, ionomers, chlorinated polyethylene, chlorinated polypropylene, polyamides, polyesters and polyvinyl acetate. In the above α-olefin-vinyl ester copolymer, α-olefin includes ethylene, butylene, 1-butene, 1
-Pentene or the like can be used, and ethylene is particularly preferable.
Examples of the vinyl ester include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate and the like, and vinyl acetate is particularly preferable.

Usually, as the thermoplastic resin, polyvinyl butyral, polyurethane, ethylene-vinyl acetate copolymer and the like are used, and plasticized polyvinyl butyral and polyurethane are particularly preferably used.

Further, the intermediate film may be blended with a plasticizer, an ultraviolet absorber, an antioxidant and the like.

Since there are various kinds of commercially available laminated glass depending on the color of the transparent substrate such as glass or the color of the interlayer film, the laminated glass is sorted according to their color before crushing. Is preferred.

Next, the laminated glass is crushed. As the crushing method, any method can be adopted as long as it can crush the laminated glass sheet such as a method using a press roll and a hammering device. In this crushing process of the laminated glass, most of the transparent substrate 1 is detached from the intermediate film 2. However, since the transparent substrate 1 is crushed by mechanically striking it as described above and separated from the intermediate film 2, the broken pieces 1a (including fine powder and the like) of the transparent substrate 1 are embedded in the intermediate film 2. The transparent substrate 1 cannot be completely separated from the intermediate film 2 because of adhesion.

The degree of separation of the transparent substrate 1 can be adjusted by setting the pressure of the press roll, the clearance of the roll, the hammering speed, etc., and the desired haze value of the intermediate film for the diffused laminated glass. Can be changed arbitrarily. Usually, as shown in FIG. 1B, 2 to 20% by weight of the fragment 1 a of the transparent substrate with respect to the intermediate film 2 is attached to the intermediate film 2.

The transparent substrate 1 separated in this way
Can be reprocessed by melting, for example.

Next, the intermediate film 2 to which the fragments 1a of the transparent substrate are attached is kneaded to obtain a resin composition in which the particles 1b of the transparent substrate are dispersed, and as shown in FIG. 1 (c). This resin composition is formed into a sheet.

The step of kneading the intermediate film and the step of molding the resin composition may be carried out separately or in series. For example, the resin composition obtained may be molded into a sheet by a molding machine after the intermediate film 2 having the pieces 1a of the transparent substrate attached thereto is kneaded into the kneading machine and sufficiently kneaded, or kneading molding The intermediate film 2 to which the fragments 1a of the transparent substrate are attached may be put into the machine and kneading and molding may be continuously performed. Examples of the molding method include conventionally known methods such as a calender roll method, die extrusion and profile extrusion.

At the time of molding the intermediate film 2, a plasticizer, a heat stabilizer, an ultraviolet absorber, an antioxidant, a dye or the like may be added to the intermediate film 2 if necessary. Further, in order to impart a high penetration resistance to the laminated glass, an adhesiveness adjusting agent such as a metal salt may be added. Further, in order to facilitate air escape during the production of the laminated glass, a fine emboss may be provided on the surface of the intermediate film 2 when forming the intermediate film 2.

The use of the intermediate film for diffused laminated glass obtained by re-shaping as described above can produce a diffused laminated glass according to a conventional method.
The intermediate film may be arranged between two translucent substrates, and the laminated body may be heated and pressure bonded. As the translucent substrate, those mentioned above can be used.

As shown in FIG. 2, the intermediate film obtained by the method of the present invention has a light-scattering property because it contains particles 1b (fragments, fine powders, etc.) composed of a light-transmissive substrate, and therefore The laminated glass using this intermediate film 2 can be used as a frosted glass-like safety glass.

Here, the degree of diffused light of the laminated glass is determined by the amount, particle size, particle size distribution, etc. of the particles 1b of the translucent substrate dispersed in the intermediate film 2, so that the above-mentioned separation conditions are changed. It can be set arbitrarily. Usually, it is preferable to set the haze value of the laminated glass to be 60 to 90%.

[0023]

[Function] The unnecessary laminated glass is crushed, and then the intermediate film having the pieces of the transparent substrate adhered thereto is kneaded to form a resin composition in which particles are dispersed. It can be used to produce a diffused interlayer film and laminated glass. Also, a transparent substrate such as glass separated from the intermediate film can be recycled.

According to this method, a part of the transparent substrate is mixed in the resin composition of the intermediate film, but this part of the transparent substrate is effectively used for light scattering to add a light scattering function. It can be used as an intermediate film or safety glass.

[0025]

EXAMPLES The present invention will be described below based on examples.

Example 1 Between two sheets of float plate glass having a thickness of 2.5 mm, a thickness of 0.
A 150 mm × 300 mm square transparent laminated glass was prepared by sandwiching a 76 mm polyvinyl butyral interlayer film. Attach this laminated glass to the automatic hammering device, hit the entire surface of the laminated glass evenly with a hammer,
The glass was crushed and separated into a glass piece and an interlayer film. This automatic hammering device has a bottom surface with a radius of curvature of 50 mm and is formed into a curved surface with a striking effective diameter of 25 mm and a weight of 240 g.
It has a hammer head and the impact force can be adjusted with a spring screw.

In this embodiment, the automatic hammering device having such a structure is used. As shown in the locus of the hammer head in FIG. 3, the spring pressure is 10 kg and the number of hits is 7
2 times / minute, horizontal feed speed 15 mm / sec, vertical feed pitch 10
When the ball was struck under the condition of mm, about 20 g of glass fragments adhered and remained on the surface of the intermediate film per 100 g of the intermediate film.
The size of the remaining glass piece was 3 mm square or less.

Next, the obtained intermediate film was roll-kneaded with a heating roll to form a sheet having a thickness of 0.76 mm. At this time, among the glass pieces remaining on the surface of the intermediate film, large ones were crushed and sufficiently kneaded while adjusting the roll clearance so as to be uniformly dispersed in the film.

In this way, the remolded interlayer film was sandwiched between two sheets of float plate glass having a thickness of 2.5 mm and heat-pressed to prepare a laminated glass.

Table 1 shows the optical characteristics of the obtained laminated glass. The total light transmittance and the haze value are JIS R
It was measured according to 3212.

Example 2 A laminated glass was prepared in the same manner as in Example 1 except that the spring pressure was changed to 8 kg in Example 1. At this time, about 30 g of glass fragments per 100 g of the intermediate film adhered and remained on the surface of the intermediate film.

Table 1 shows the optical characteristics of the obtained laminated glass.

Example 3 A laminated glass was prepared in the same manner as in Example 1 except that the spring pressure was 12 kg in Example 1. At this time, about 15 g of glass pieces adhered and remained on the surface of the intermediate film per 100 g of the intermediate film.

The optical characteristics of the obtained laminated glass are shown in Table 1.

[0035]

[Table 1]

[0036]

EFFECTS OF THE INVENTION According to the present invention, unnecessary laminated glass is crushed, and then the intermediate film having glass pieces attached is kneaded to form a resin composition in which glass particles are dispersed.
The interlayer film of laminated glass that has become unnecessary can be effectively used to manufacture a diffused interlayer film and laminated glass,
In addition, the manufacturing method is simple, and the quality of the obtained product is less uneven.

[Brief description of drawings]

1A to 1C are process diagrams showing a method for producing an intermediate film for diffused laminated glass of the present invention.

FIG. 2 is an enlarged view of part A of FIG.

FIG. 3 is a schematic plan view showing a trajectory of a hammer head in the crushing process of the present invention.

[Explanation of symbols]

1 Translucent substrate 1a Fragment of translucent substrate 1b Translucent substrate particles 2 Intermediate film

Claims (2)

[Claims] 1. A step of crushing a laminated glass formed by disposing an intermediate film made of a thermoplastic resin between two transparent substrates, and kneading the intermediate film to which the fragments of the transparent substrate adhere. A method for producing an intermediate film for light-scattering laminated glass, comprising a step of obtaining a resin composition in which particles of a transparent substrate are dispersed, and a step of molding the resin composition. 2. A step of crushing a laminated glass formed by disposing an intermediate film made of a thermoplastic resin between two transparent substrates, and kneading the intermediate film to which the fragments of the transparent substrate adhere. To obtain a resin composition in which particles of a transparent substrate are dispersed, a step of molding the resin composition to form an intermediate film for diffused laminated glass, and the intermediate film between two transparent substrates. A method for producing a diffused laminated glass, which comprises the step of arranging and pressure bonding.