JPH05286010A - Method and device for manufacturing thermoplastic resin sheet - Google Patents

Abstract

PURPOSE:To prevent uneven molding from being produced in an interface between a first resin layer and a second resin layer in a device for manufacturing a thermoplastic resin sheet wherein the second resin layer formed from a second thermoplastic resin is embedded in the first resin layer formed from a first thermoplastic resin, both the resins having different melt viscosities. CONSTITUTION:A conduit 2, through which a second thermoplastic resin can be fed, is disposed in a manifold 3 of a mold 1, into which a first thermoplastic resin (a) is supplied. The conduit 2 has a second resin feed passage, through which the second resin is fed, and a slit section. A heat insulating portion is provided around the second passage. By means of the portion, the second resin fed into the second passage is thermally insulated from the first resin (a) fed into the manifold 3. Consequently, the second resin having proper viscosity can be forced into the manifold 3 from the slit section of the conduit 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 a thermoplastic resin sheet having two resin layers embedded in one resin layer by extrusion molding two types of thermoplastic resins, and a method thereof. The present invention relates to a thermoplastic resin sheet manufacturing apparatus preferably used for the above, and more particularly to a thermoplastic resin sheet manufacturing method and a manufacturing apparatus thereof, in which two types of thermoplastic resins having different melt viscosities are extrusion-molded.

[0002]

2. Description of the Related Art Windshield glass used for automobiles and airplanes, and laminated glass used for windows of buildings are polyvinyl butyral resins plasticized between two glass plates facing each other. It is constituted by sandwiching an intermediate film consisting of.

In order to impart various functions to the intermediate film used in such a laminated glass, a second resin layer is formed in the first resin layer.
An intermediate film having a multi-layer structure formed by embedding the above resin layer has been studied. For example, by using polyvinyl butyral resin as the thermoplastic resin forming the first resin layer and polyvinyl hexanal as the thermoplastic resin forming the second resin layer, an interlayer film having excellent sound insulation properties can be obtained. ..

As a technique relating to the thermoplastic resin sheet having such a multilayer structure, for example, USP 3,32
No. 1,804 discloses a manufacturing apparatus having a structure in which a conduit for forming an intermediate layer is arranged in a mold manifold, and USP 3,40,099 discloses a manufacturing apparatus. A method of manufacturing a sheet of three kinds and five layers by disposing a conduit having a double cylinder structure in a manifold is disclosed.

[0005]

However, in any of the above techniques, the second thermoplastic resin (hereinafter referred to as the second resin) extruded from the conduit is the first thermoplastic resin (hereinafter referred to as the first resin). The second resin cannot be extruded at an appropriate temperature because the extrusion temperature of the second resin is close to the temperature of the first resin due to the influence of the temperature of the second resin.

Therefore, for example, when a resin having a different melt viscosity from the first resin is used as the second resin, the second resin can be extruded with an appropriate molding viscosity (for example, with substantially the same viscosity as the first resin). Therefore, the interface between the first resin layer formed of the first resin and the second resin layer formed of the second resin is disturbed, and as a result, the transparency of the obtained intermediate film is deteriorated. However, there were problems such as optical distortion.

The present invention has been made by paying attention to the above points, and an object of the present invention is to embed a second resin layer in a first resin layer by using two kinds of resins having different melt viscosities. It is another object of the present invention to provide a method for manufacturing a thermoplastic resin sheet and an apparatus for the same, which can prevent the disturbance at the interface between both layers when manufacturing the filled thermoplastic resin sheet.

[0008]

The apparatus for producing a thermoplastic resin sheet according to the present invention comprises a first resin layer formed of a first thermoplastic resin and embedded in the first resin layer. Second
A second resin layer formed of a thermoplastic resin, and a device for producing a thermoplastic resin sheet, the device comprising an extrusion molding die and a conduit, the extrusion molding die comprising: First
Of the thermoplastic resin, a first resin supply path for supplying the first thermoplastic resin into the manifold, and the first thermoplastic resin extruded from the manifold to the outside of the first resin. A slit-shaped die orifice in which a layer is formed, and a land portion provided between the manifold and the slit-shaped die orifice, the conduit being disposed in the manifold, Second
A second resin supply path to which the thermoplastic resin of
The resin supply passage has a laterally long slit portion that opens into the manifold, and a heat insulating portion provided around the second resin supply passage, thereby achieving the above object.

In the method for producing a thermoplastic resin sheet of the present invention, the first and second thermoplastic resins having different melt viscosities are supplied to the first resin supply path and the second resin by using the above-mentioned production apparatus. It is characterized in that each is supplied from a supply path, and thereby the above-mentioned object is achieved.

1 and 2 show an example of an apparatus for producing a thermoplastic resin sheet according to the present invention.

The apparatus has an extrusion mold 1 and a conduit 2. The mold 1 includes a manifold 3 in which a conduit 2 is arranged, side plates 15 and 16 respectively provided in the width direction of the manifold 3, and a resin supply for supplying a molten first resin a into the manifold 3. It has a passage 4, a slit-shaped die orifice 6 as an extruded sheet outlet, and a land portion 7 as a resin passage through which the first resin a is sent from the manifold 3 to the die orifice 6.

The manifold 3 has a substantially circular cross section, and is provided over substantially the entire width of the mold 1. The resin supply passage 4 connected to the substantially central portion of the manifold 3 is connected to a resin extrusion device (not shown) so that the first resin a is supplied from the device through the resin supply passage 4 into the manifold 3. It is configured.

A conduit 2 arranged in the manifold 3
As shown in FIG. 3, is formed of a tubular member having a closed tip. The conduit 2 is a second pipe to which the second resin b is supplied.
The resin supply passage 5, the second resin supply passage 5 has a slit portion 8 that opens into the manifold 3, and a land portion 13.

The slit portion 8 is formed laterally long so as to face the land portion 7 of the mold 1. And the second
A heat insulating section 10 is provided around the resin supply path 5.

As shown in FIG. 5, the heat insulating portion 10 has a second
It is provided on the outer peripheral portion of the conduit 2 so as to surround the resin supply path 5. The heat insulating portion 10 may be formed of a vacuum or reduced pressure space portion, a gas filled portion such as air, and a filled portion of a heat insulating material such as asbestos or glass wool.

In the example shown in FIGS. 3 to 5, the heat insulating portion 10 is formed of a decompression space portion, and the decompression space portion 10 is connected to a decompression device (not shown) for decompressing the inside thereof. 11 is provided.

The resin supply path 5 of the conduit 2 is connected to a supply device for the second resin b, and the second resin b flows into the manifold 3 through the resin supply path 5 and the slit portion 8. ..

Next, a method for producing a thermoplastic resin sheet using the above-mentioned apparatus of the present invention will be described.

The first resin a sent from the resin supply passage 4 into the manifold 3 fills the inside of the manifold 3 and is pushed out from the slit-shaped die orifice 6 through the land portion 7. On the other hand, the second resin b supplied into the resin supply passage 5 of the conduit 2 is pushed out into the manifold 3 through the land portion 13 and the slit portion 8 of the conduit 2. And
The second resin layer formed of the second resin b is the first resin a
A thermoplastic resin sheet having a three-layer structure is molded by being embedded in the first resin layer formed in.

Since the second resin supply passage 5 of the conduit 2 is surrounded by the heat insulating portion 10, the second resin supply passage 5 in the conduit 2 is
The resin b is not affected by the temperature of the first resin a in the manifold 3, so that the first resin a and the second resin b are resins having different melt viscosities and their proper molding temperatures are set. Even if it is, the second resin b is extruded into the manifold 3 from the slit portion 8 of the conduit 2 with a desired melt viscosity.

The first resin a and the second resin b used in the present invention are different thermoplastic resins, and the first resin a and the second resin b are, for example, polyethylene, polypropylene, polystyrene, polycarbonate, vinyl chloride. Examples include resins, nylon resins, polyvinyl acetals, acrylic resins, acetal resins, polyester resins and the like. A plasticizer, a filler and the like may be added to these thermoplastic resins.

The conduit used in the apparatus for producing a thermoplastic resin sheet may be constructed as shown in FIGS. The conduit 20 is provided with a temperature adjusting pipe 12 such as a jacket through which a heat medium passes in the second resin supply passage 5. The heat medium supplied into the temperature adjusting tube 12 is at a molding temperature of the second resin b. As the heat medium, steam or oil can be used.

Further, the conduit used in the apparatus for producing a thermoplastic resin sheet may be constructed as shown in FIG.
In addition to the conduit 20 having the configuration shown in FIGS. 6 to 8, the conduit 30 is provided with a temperature adjusting pipe 14 such as a jacket through which a heating medium passes also outside the second resin supply passage 5.
The heat medium supplied into the temperature adjusting tube 14 is set to the molding temperature of the second resin b, and steam, oil or the like can be used as the heat medium.

When the conduits 20 and 30 having these structures are used, the temperature of the second resin b in the second resin supply passage 5 is influenced by the temperature adjusting tubes 12 and 14, and the molding temperature of the second resin b is affected. Therefore, the temperature of the first resin a is not affected. Therefore, the second resin b can be extruded into the manifold 3 from the slit portion 8 of the conduit 2 with an appropriate melt viscosity, and a three-layer structure having a uniform molding at the interface between the first resin layer and the second resin layer can be obtained. A thermoplastic resin sheet can be manufactured.

Although the apparatus for manufacturing the T-die has been described above, the present invention can be implemented in the apparatus for the L-die. Furthermore, the present invention can be applied not only to a thermoplastic resin sheet having a three-layer structure, but also to a case where a thermoplastic resin sheet having four or more layers is manufactured.

[0026]

Since the heat insulating portion is provided around the second resin supply passage of the conduit, the second resin supply passage and the manifold are insulated. Therefore, the temperature of the second resin in the conduit is not influenced by the temperature of the first resin in the manifold, and the second resin can be extruded into the manifold from the slit portion of the conduit with a desired melt viscosity. Therefore, the first
Even if the resin and the second resin have different melt viscosities, no disturbance occurs at the interface between the first resin layer and the second resin layer.

[0027]

EXAMPLES The present invention will be described below with reference to examples and comparative examples.

Example 1 Using the apparatus shown in FIGS. 1 to 5, a thermoplastic resin sheet was extruded under the following conditions.

<Mold for Extrusion Molding> The dimensions of each member of the extrusion molding die used are as follows.

Width of die orifice 6: 800 mm Diameter of manifold 3: R30 mm Diameter of conduit 2: R15 mm Length of land 7: 50 mm Clearance of land 7: 0.5 mm <Extrusion condition> Resin amount ratio: first resin : Second resin = 30 kg / Hr: 9
kg / Hr Resin temperature: First resin: 170 ° C. Second resin: 190 ° C. Type of resin used: First resin: polyvinyl butyral resin Second resin: polyvinyl hexanal resin As shown in FIG. 3, the land portion of the conduit is gold. Set the conduit in the mold manifold close to the land of the mold, connect the vacuum pump to the heat insulation part (vacuum part) provided in the conduit, and depressurize the vacuum part (-760 mmHg). The 1st resin and the 2nd resin were extruded to form a thermoplastic resin sheet.

A laminated glass produced by using the obtained thermoplastic resin sheet as an intermediate film was evaluated to examine the relationship with the temperature of the first resin. The laminated glass was evaluated by observing its appearance for optical distortion. The temperature of the second resin was measured by inserting a thermocouple into the second resin supply passage of the conduit.

As a result, the second resin temperature was 188 ° C., and no optical distortion was observed in the laminated glass.

Example 2 A thermoplastic resin was prepared under the same conditions as in Example 1 except that in the apparatus shown in FIG. 1, a heat insulating section filled with glass wool was used instead of the heat insulating section having a vacuum section. The sheet was extruded.

The thermoplastic resin sheet thus obtained was evaluated in the same manner as in Example 1.

As a result, the second resin temperature was 185 ° C., and slight optical distortion was observed in the laminated glass.

Example 3 A thermoplastic resin sheet was extruded under the same conditions as in Example 1 except that the conduit shown in FIG. 9 was used.

Oil having a constant temperature (190 ° C.) was circulated through the temperature adjusting pipe 12 in the central portion of the conduit and the temperature adjusting pipe 14 in the outer peripheral portion.

The thermoplastic resin sheet thus obtained was evaluated in the same manner as in Example 1.

As a result, the second resin temperature was 189 ° C., and no optical distortion was observed in the laminated glass.

Example 4 A thermoplastic resin sheet was extruded under the same conditions as in Example 3 except that a heat insulating part filled with glass wool was used instead of the heat insulating part having a vacuum part.

The thermoplastic resin sheet thus obtained was evaluated in the same manner as in Example 1.

As a result, the second resin temperature was 187 ° C., and no optical distortion was observed in the laminated glass.

Example 5 A thermoplastic resin sheet was used under the same conditions as in Example 1 except that the conduit shown in FIG. 10 was used and a mold having a manifold having an elliptical cross section was used according to the outer shape of the conduit. Was extruded. Since the cross section of the conduit 2 is a vertically long ellipse,
The angle θ formed by the extension line of the slit portion 8 and the outer peripheral line of the conduit 2 is about 120 degrees. Therefore, the second
The contact angle when the resin is embedded in the first resin also becomes an obtuse angle, and the stress generated at the interface between the second resin and the first resin becomes small. As a result, the interface disorder between the second resin layer and the first resin layer was further reduced, and no distortion was observed in the obtained laminated glass. In addition, it is preferable to determine the degree of the ellipse of the conduit 2 so that the angle θ is about 110 to 150 degrees.

Comparative Example In the apparatus shown in FIG. 1, a thermoplastic resin sheet was extruded under the same conditions as in Example 1 except that a conduit having no heat insulating section was used.

The thermoplastic resin sheet thus obtained was evaluated in the same manner as in Example 1.

As a result, the second resin temperature was 180 ° C., and a large optical distortion was observed in the laminated glass.

[0047]

According to the present invention, the first of the different melt viscosities is used.
Even when a thermoplastic resin sheet is manufactured using a resin and a second resin, the thermoplastic resin sheet having an intermediate film does not cause disturbance at the interface between the first resin layer and the second resin layer. Does not deteriorate in transparency or cause optical distortion. Therefore, for example, if a polyvinyl butyral resin is used as the first resin and polyvinyl hexanal is used as the second resin, it is possible to produce a laminated glass that is excellent in sound insulation, is transparent, and has no optical distortion.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view of an embodiment of the thermoplastic resin sheet manufacturing apparatus of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3 is a partially cutaway plan view of a conduit used in the manufacturing apparatus of FIG.

4 is a partially cutaway front view of a conduit used in the manufacturing apparatus of FIG.

5 is a cross-sectional view of the conduit shown in FIG.

FIG. 6 is a partially cutaway plan view of another embodiment of a conduit.

FIG. 7 is a partially cutaway front view of another embodiment of a conduit.

8 is a cross-sectional view of the conduit shown in FIG.

FIG. 9 is a cross-sectional view of yet another embodiment of a conduit.

FIG. 10 is a cross-sectional view of yet another embodiment of a conduit.

[Explanation of symbols]

 1 Extrusion Mold 2 Conduit 3 Manifold 4 First Resin Supply Channel 5 Second Resin Supply Channel 6 Slit-shaped Die Orifice 7 Land Part 8 Slit Part 10 Heat Insulation Part 12 Temperature Control Pipe 13 Conduit Land Part 14 Temperature Control Pipe 15 Side plate 16 Side plate a First thermoplastic resin b Second thermoplastic resin

Claims (2)

[Claims] 1. A first resin layer formed of a first thermoplastic resin, and a second resin layer embedded in the first resin layer and formed of a second thermoplastic resin. An apparatus for producing a thermoplastic resin sheet, comprising: an extrusion mold and a conduit, wherein the extrusion mold is a manifold to which a first thermoplastic resin is supplied; A first resin supply path for supplying a first thermoplastic resin into the manifold;
A slit-shaped die orifice in which the first thermoplastic resin is extruded from the manifold to form the first resin layer, and a land portion provided between the manifold and the slit-shaped die orifice, And the conduit is disposed in the manifold, the conduit is provided with a second resin supply passage to which the second thermoplastic resin is supplied, and a lateral direction in which the second resin supply passage is opened in the manifold. A long slit portion, and a heat insulating portion provided around the second resin supply passage,
For manufacturing a thermoplastic resin sheet having a. 2. The manufacturing apparatus according to claim 1, wherein the first thermoplastic resin and the second thermoplastic resin having different melt viscosities are respectively supplied from the first resin supply passage and the second resin supply passage. A method for producing a thermoplastic resin sheet, which comprises supplying the thermoplastic resin sheet.