JPH05309655A - Method for recovering interlayer from laminated glass - Google Patents

Abstract

PURPOSE:To provide a method for recycling waste laminated glass without disposing the waste. CONSTITUTION:By grinding laminated glass, which is produced by arranging an interlayer between a pair of glass plates, the interlayer, to which pieces of glass are adhered, is obtained. Next, the interlayer is charged in an agitator 3, in which water is housed and which has agitating bars 5, so as to rotate a rotating shaft 4 in order to give shearing force to the interlayer under the condition that the speed difference between the interlayer and the water is larger than 1.8m/sec while the interlayer is being swollen, resulting in removing the pieces of glass from the interlayer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering an interlayer film from a laminated glass, which can be reused by separating the interlayer film from the glass in a laminated glass used for vehicles or construction. Regarding the method.

[0002]

2. Description of the Related Art Laminated glass used for safety glass such as building window glass and automobile windshield is
It is formed by disposing an interlayer film for laminated glass between two glass plates. As the intermediate film, a film made of a thermoplastic resin such as polyvinyl butyral resin is generally used.

Laminated glass, which is no longer needed due to size and appearance problems, is collected from the market, and most of it is buried in the ground because the glass plate and the interlayer cannot be easily separated. Or, the intermediate film to which the glass pieces adhere after crushing the glass plate is burned or otherwise disposed of.

[0004]

As described above, burying unnecessary laminated glass causes a problem of environmental destruction.
Further, when burning the interlayer film to which the glass pieces are attached, there is a problem that unmelted glass becomes glass dust and pollutes the atmosphere. On the other hand, there is a problem that the molten glass accumulates on the stoker in the combustion furnace and interferes with the combustion device.

The present invention is intended to solve the above-mentioned drawbacks, and an object of the present invention is to provide a method capable of reusing unused laminated glass without discarding it.

[0006]

A method for recovering laminated glass from an intermediate film according to the present invention is a method in which an intermediate film formed by disposing an intermediate film between a pair of glass plates is crushed to form an intermediate film having glass pieces attached thereto. The method includes a step of obtaining a membrane, a step of immersing the intermediate membrane in water, and applying a shearing force to the intermediate membrane so that a speed difference with water is 1.8 m / sec or more. Can be achieved.

[0007] In a preferred embodiment, the step of applying a shearing force to the intermediate film is to rotate the intermediate film.

[0008] In a preferred embodiment, the step of applying a shearing force to the intermediate film is to apply a water stream to the intermediate film.

Next, the present invention will be described in detail.

The laminated glass is formed by placing an intermediate film 2 between two glass plates 1 and 1 as shown in FIG. 1 (a). The glass plate is usually a transparent, semi-transparent, opaque, or colored plate glass, but may be a plastic plate, or those having a heat ray reflective layer such as a metal layer formed on the inner surface thereof. good.
Further, the two glass plates 1 and 1 may be of the same type or of different types. The thickness and size of the glass 1 are not limited, and may be generally commercially available. Specifically, the thickness is 1 to 20 mm.

The resin for forming the intermediate film 2 is usually
A thermoplastic resin, a conventionally known resin used for a laminated glass of this type, for example, polyvinyl butyral, polyurethane, ethylene-vinyl acetate copolymer and the like can be mentioned. Particularly, polyvinylidized by adding a plasticizer. Butyral and polyurethane are preferred. Also,
An ultraviolet absorber, an antioxidant, etc. may be blended in the intermediate film.

In order to recover the intermediate film from the unnecessary laminated glass on the market, first, the unnecessary laminated glass is crushed and the glass piece 1 is crushed as shown in FIG. 1 (b).
The intermediate film 2 to which a is attached is obtained.

As a method of crushing laminated glass, a mechanical crushing method using a press roll and a hammer ring device can be adopted. By this crushing of the laminated glass, most of the glass plate 1 is removed from the intermediate film 2. However, since the glass plate 1 is mechanically hit and crushed, the glass plate 1 cannot be completely removed from the intermediate film 2, and as shown in FIG. 1B, glass fragments 1a (including fine powder and the like) are included. Part of () adheres in a state of being embedded in the intermediate film 2. The degree of removal of the glass plate 1 from the intermediate film 2 can be adjusted by crushing conditions such as pressure of a press roll, roll clearance, and hammering speed. Normally, 2 to 20% by weight of the glass piece 1a with respect to the intermediate film 2 is attached to the intermediate film 2.

Since there are various types of laminated glass depending on the color of the glass plate, the color of the intermediate film 2, and the like, it is preferable to sort the unnecessary laminated glass by each color before crushing it.

Next, the intermediate film 2 to which the glass piece 1a is attached is immersed in water.

This step is intended to make it easier to remove the attached glass piece 1a from the intermediate film 2 by swelling the surface of the intermediate film 2 and reducing the adhesive force of the intermediate film 2. The water temperature is preferably 5 ° C to 20 ° C, and the immersion time is
It is preferable that the intermediate film 2 has sufficient time to swell.

A shearing force is applied to the intermediate film 2 to which the glass piece 1a is attached, at the same time as the intermediate film 2 is immersed in water or after a predetermined time.

This step is for completely removing the glass piece 1a from the intermediate film 2 by applying a physical force to the intermediate film 2.

The shearing force applied to the intermediate film 2 is a force such that the speed difference between the intermediate film 2 and water is 1.8 m / sec or more, and preferably 2.0 m / sec or more. When the speed difference between the intermediate film 2 and water is less than 1.8 m / sec, the glass piece 1a cannot be completely removed from the intermediate film 2 because the force exerted by the water on the glass piece 1a is small.

As a method of applying a shearing force to the intermediate film 2 to which the glass piece 1a is attached, there are, for example, a method of rotating the intermediate film 2 and a method of applying a water stream to the intermediate film 2.

As a method of rotating the intermediate film 2 having the glass 1a attached thereto, for example, a stirring rod 5 as shown in FIG.
There is a method of rotating the intermediate film 2 having the glass piece 1a attached thereto while entwining it with the stirring rod 5 by using the stirrer 3 having.
In the case of the stirrer 3 shown in FIG. 2, the stirring rods 5 are horizontally extended from the rotary shaft 4 on both sides, and are provided at the upper, middle, and lower stages, respectively. Furthermore, the rotating intermediate film 2
In order to prevent the detachment, the projections 6 projecting in the upside-down direction are provided at both ends thereof. The number, thickness, length, shape, and direction and position of the stirring bar 5 provided on the center bar are not limited. The position of the protrusion 6 is not limited to the tip of the stirring rod 5, and the number thereof may be plural in one stirring rod. Further, the direction may be either up or down. The size is not limited. The protrusion 6 may not be provided depending on the shape of the stirring rod 5.

The direction of rotation of the stirring rod 5 is not limited, and it may be rotated in one direction and then in another direction. Further, regarding the number of rotations of the rotating shaft 4, the speed difference between the intermediate film 2 and water is 1.
The rotation speed is 8 m / sec or more, and the intermediate film 2
It depends on the size and thickness. Further, the number of rotations of the central shaft 4 is appropriately set depending on the length of the stirring rod 5. For example, in the case of the stirrer 3 of FIG. 2, the rotation speed of the central shaft 4 is about 700 r.
pm or more, preferably 800 rpm or more.

As a method of applying a water stream to the intermediate film 2 to which the glass piece 1a adheres, for example, there is a method of ejecting water at a high speed from a nozzle 7 and applying a jet water stream using an apparatus as shown in FIG. In this case, the velocity of the water flow is
It is 1.8 m / sec or more. In the case of the device shown in FIG.
Two nozzles 7 are provided, and the water flow direction thereof is preferably parallel to the surface of the intermediate film 2. The number of nozzles 7 is not limited, and the water flow direction is not limited. Furthermore, the water flow velocity of each of the nozzles 7 may be the same or different.

In the present invention, the time for applying the shearing force to the intermediate film 2 is the time for removing the glass 1a from the intermediate film 2.

[0025]

Function: The intermediate film having the glass pieces adhered is soaked in water, and a shearing force is applied to the intermediate film so that the speed difference with water is 1.8 m / sec or more. The glass piece can be removed from the intermediate film by imparting a physical shearing force to the glass piece at the same time as swelling with water to reduce the adhesive force of the glass piece to the intermediate film.

[0026]

EXAMPLES Next, the present invention will be described with reference to examples.

Example 1 A thickness of 0.7 was set between two sheets of float plate glass having a thickness of 2.5 mm.
A transparent laminated glass of 150 mm × 300 mm was prepared by sandwiching an interlayer film made of 6 mm polyvinyl butyral. This laminated glass was attached to an automatic hammering device. This automatic hammer ring device has a bottom with a radius of 5
Curved surface with a curvature of 0 mm and an effective impact diameter of 5 m
The hammer head weighs 240 m and weighs 240 g, and the impact force of the hammer head can be adjusted with a spring screw. Then, the entire surface of the laminated glass was uniformly hit with a hammer head to crush the glass plate, and the glass piece and the intermediate film were separated. Glass pieces were still attached to the interlayer film.

Next, this intermediate film is immersed in water having a water temperature of 20 ° C., and the stirrer 3 (the length a of the stirring rod 5 is a = 5) as shown in FIG.
00 mm, c = 100 mm, d = 200 mm, protrusion height b = 20 mm, diameter t of stirring rod 5 = 10 mm), entangle the intermediate film with stirring rod 5 and move all stirring rods in the same direction. The glass pieces were removed from the intermediate film by rotating at a rotation speed of 800 rpm and applying a shearing force with a speed difference between the intermediate film and water of 2.0 m / sec.

In this way, the interlayer film from which the glass pieces were removed was kneaded with a heating roll and remolded. This interlayer film was sandwiched between two sheets of float plate glass having a thickness of 2.5 mm and thermocompression bonded to produce a laminated glass.

Example 2 Example 1 is different from Example 1 except that the rotation of the stirring rod is reversed (right rotation and left rotation are alternately performed for 1 minute each).
A glass piece was removed from the intermediate film in the same manner as in 1. and a laminated glass was prepared in the same manner as in Example 1 using this intermediate film.

Example 3 Example 1 was repeated except that the apparatus shown in FIG. 3 was used instead of the stirrer shown in FIG. 2 and the jet water flow from the nozzle was alternately applied to the interlayer film. A glass piece was removed from the intermediate film in the same manner as in 1. and a laminated glass was prepared in the same manner as in Example 1 using this intermediate film.

Comparative Example 1 In Example 1, a glass piece was removed from the interlayer film by the same method as in Example 1 except that the interlayer film was not treated with water using a stirrer, and this interlayer film was used. Example 1
A laminated glass was prepared in the same manner as in.

Comparative Example 2 Same as Example 1 except that the stirring rod 5 was rotated at 400 rpm and a shearing force was applied so that the speed difference between the intermediate film and water was 1.0 m / sec. A glass piece was removed from the intermediate film by the method of 1. and a laminated glass was prepared by the same method as in Example 1 using this intermediate film.

Comparative Example 3 The same as Example 1 except that the stirring rod 5 was rotated at 600 rpm and a shearing force was applied so that the speed difference between the intermediate film and water was 1.5 m / sec. A glass piece was removed from the intermediate film by the method of 1. and a laminated glass was prepared by the same method as in Example 1 using this intermediate film.

The optical properties of the laminated glass obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were measured according to JIS3212. The results are shown in Table 1.

[0036]

[Table 1]

From Table 1, it can be seen that the laminated glasses obtained in Examples 1 to 3 have a high light transmittance and a low haze value.

[0038]

As is apparent from the above description, according to the present invention, the glass can be completely removed from the interlayer film of the laminated glass that is no longer needed, and the interlayer film can be recovered. Therefore, this intermediate film can be reused. Furthermore, these interlayer films can be used for new applications such as transparent diffused glass. Furthermore, the plasticizer is separated from the intermediate film, and the intermediate film is bonded with an adhesive or
This can be emulsified and used as a soil agent.

[Brief description of drawings]

FIG. 1A is a cross-sectional view of laminated glass, and FIG.
It is sectional drawing of the intermediate film after crushing the laminated glass of (a) and removing glass.

FIG. 2 is a schematic sectional view of a stirrer used in one embodiment of the present invention.

FIG. 3 is a top view of a device capable of discharging water at high speed, which is used in another embodiment of the present invention.

[Explanation of symbols]

 1 Glass 1a Glass Piece 2 Intermediate Film 3 Stirrer 4 Rotating Shaft 5 Stirring Rod 6 Protrusion 7 Nozzle

Claims (3)

[Claims] 1. A step of crushing a laminated glass formed by arranging an intermediate film between a pair of glass plates to obtain an intermediate film having glass pieces adhered thereto, dipping the intermediate film in water, and ,
A method for regenerating an interlayer film for laminated glass, which comprises a step of applying a shearing force such that the speed difference with water is 1.8 m / sec or more. 2. The method for recovering an interlayer film from a laminated glass according to claim 1, wherein the step of applying a shearing force to the interlayer film is rotating the interlayer film. 3. The method for recovering an interlayer film from a laminated glass according to claim 1, wherein the step of applying a shearing force to the interlayer film is applying a water stream to the interlayer film.