JPH0584803A - Production equipment of thermoplastic resin sheet - Google Patents

Abstract

PURPOSE:To manufacture thermoplastic resin sheet, in which the boundary between the end part of first resin layer and second resin layer is unclear, in a production equipment of the thermoplastic resin sheet, which is produced by imbedding the second resin layer in the first resin layer. CONSTITUTION:An insert nozzle 2, through which second thermoplastic resin (b) can be fed, is arranged in the manifold 3, to which first thermoplastic resin (a) is fed, of a mold 1. The insert nozzle 2 is supported in a cantilever shape to the mold 1. and has a second resin feed passage 5, through which the second thermoplastic resin (b) is fed, and a slit 8. Since the resin (b), which is extruded from the tip 8a of the slit 8 in the manifold 3, tends to laterally flow more easily than the resin (b), which is extruded from the base 8b of the slit 8 in the manifold 3, the boundary between the first resin layer and the end part, which is formed by the resin (b) extruded from the tip 8a, of the second resin layer becomes unclear.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a thermoplastic resin sheet in which two kinds of thermoplastic resins are extrusion-molded and the other resin layer is embedded in the other resin layer.

[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 manufacture an interlayer film used for such laminated glass, generally, polyvinyl butyral resin heated and melted in a cylinder is fed to an extrusion molding die and extruded from the extrusion molding die. A method for obtaining a thin film intermediate film is known. The interlayer film thus obtained is colorless and transparent and allows most of the light rays to pass therethrough. Therefore, in order to limit the transmission of the light rays, attempts have been made to provide a belt-shaped colored portion in a part of the width of the interlayer film.

For example, in a thermoplastic resin sheet used for a windshield of an automobile, it has been considered to provide a colored zone having a concentration gradient in the upper region of the sheet, and such a colored zone allows a driver to pass through the windshield. The sun rays that illuminate the sun can be reduced. In addition, in vehicles and residential windows, products having translucent parts, opaque parts and band parts having different light refractive indices due to colorants and fillers are desired in order to provide light-improving properties and blinding effects. ing.

As a method of manufacturing a sheet having such a three-layer structure, for example, in USP 3,400,190, a probe type nozzle for supplying a colored resin is provided so as to project inside the manifold, and There has been proposed a method of embedding a colored resin extruded from a nozzle in a supplied mainstream resin.

[0006]

However, in the above method, since the colored resin is extruded in the same direction as the flow direction of the mainstream resin, the end of the colored band embedded in the mainstream resin is not clear in the mainstream resin. is there. As a result, for example, it is not possible to obtain a sheet in which the density of the colored band gradually decreases.

By making the orifice of the nozzle into a wedge shape, the cross-sectional shape of the colored band becomes a wedge shape,
Although it is possible to make the edges of the colored band slightly obscure, there is a demand for a sheet whose boundaries are more obscure.

The present invention has been made by paying attention to the above points, and an object of the present invention is to provide a heat treatment in which the boundary between the end portion of the second resin layer and the first resin layer is unclear as compared with the prior art. Another object of the present invention is to provide a thermoplastic resin sheet manufacturing apparatus capable of obtaining a thermoplastic resin sheet.

[0009]

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 having a predetermined width formed of the thermoplastic resin of
An apparatus for producing a thermoplastic resin sheet, comprising: an extrusion molding die; and an insert nozzle, the extrusion molding die being 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; A land portion provided between the manifold and the slit-shaped die orifice, the insert nozzle is disposed in the manifold, and a base portion of the insert nozzle is supported by a mold in a cantilever manner. The insert nozzle has a second resin supply path to which the second thermoplastic resin is supplied, and a laterally long slit portion in which the second resin supply path opens into the manifold,
The opening edge of the front portion of the slit portion is located on the rear side of the manifold as compared with the opening edge of the base portion of the slit portion, thereby achieving the above object.

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 molding die 1 and an insert nozzle 2. The mold 1 is an insert nozzle 2
A manifold 3 in which is disposed, and a manifold 3
Side plates 15 and 16 respectively provided in the width direction of the die, the die adapter 11, the resin supply passage 4 for supplying the molten first thermoplastic resin a (hereinafter referred to as the first resin) into the manifold 3, and the extrusion. Slit-shaped die orifice 6 as a sheet outlet, and manifold 3 to die orifice 6
Land portion 7 as a resin passage through which the first resin a is sent to
And have.

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 is connected to a resin extrusion device (not shown), and the first resin a is supplied from the device to the manifold 3 through the resin supply passage 4.

The insert nozzle 2 arranged in the manifold 3 is formed of a tubular member having a closed tip. The insert nozzle 2 is formed to have a length that is substantially half the width direction of the manifold 3, and the base portion thereof is disposed in the manifold 3 in a cantilevered state supported by the die adapter 11.

A second resin supply passage 5 for supplying a second thermoplastic resin (hereinafter referred to as a second resin) b is formed in the insert nozzle 2, and the second resin supply passage 5 is formed at the tip of the insert nozzle 2. A slit portion 8 is formed so that the resin supply passage 5 opens in the manifold 3. The insert nozzle 2
The resin supply passage 5 is connected to a resin supply device (not shown) for the second resin b, and the second resin b flows into the manifold 3 through the resin supply passage 5 and the slit portion 8.

As shown in FIG. 1, the slit portion 8 is a mold 1
It is formed to be long in the lateral direction so as to face the inside of the manifold 3 from a position corresponding to the inside of the side plate 15. The opening edge of the tip portion 8a of the slit portion 8 is located on the far side of the manifold 3 as compared with the opening edge of the base portion (side plate side) 8b of the slit portion 8. That is, the base portion 8b of the slit portion 8 is close to the land portion 7 side, and the opening edge of the slit portion 8 is inclined in plan view so that the base portion 8b of the slit portion 8 is gradually positioned on the back side of the manifold 3 as it goes to the tip portion 8a side of the slit portion 8. ing. The gap between the base portion 8b of the slit portion 8 and the land portion 7 is preferably 2 to 5 mm.

As the insert nozzle 2, for example, as shown in FIGS. 3 (a) and 3 (b), the tip portion 8a of the slit portion 8 is formed.
The inclined portion 18 may be provided only on the slit portion 8, or the inclined portion 18 may be provided over the entire slit portion 8. further,
As shown in FIG. 3B, a radius 19 may be provided at the tip of the slit 8 in order to reduce the resistance due to the flow of the first resin a.

Further, as shown in FIG. 4B, an insert nozzle 2 having an elliptical cross section is used such that the outer diameter of the base portion of the insert nozzle 2 is long in the depth direction of the manifold 3 and the outer diameter of its tip portion is short. Thus, the slit portion 8 formed in the insert nozzle 2 may be provided with an inclined portion.

3 (a) and 4 (a), the width dimension L1 of the slit portion 8 is preferably 100 to 300 mm, and the difference L3 between the base portion 8b of the slit portion 8 and the opening edge of the tip portion 8a is 5 to 5. 10 mm is preferable, L2 is 20 to 100 mm
Is preferable, and H is preferably 2 to 4 mm.

The insert nozzle 2 is a die adapter 1.
Alternatively, the die adapter 11 may be provided with a through hole, and the insert nozzle 2 may be slidably supported by inserting the insert nozzle 2 into the through hole via a packing.

When the insert nozzle 2 is slidably supported by the die adapter 11, the position of the slit portion 8 in the manifold 3 can be freely changed even during the production of the thermoplastic resin sheet. The width dimension of the resin layer formed in b can be arbitrarily changed.

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 sequentially fills the inside of the manifold 3 from the resin supply passage 4 side, 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 path 5 of the insert nozzle 2 is pushed out into the manifold 3 from the slit portion 8 of the insert nozzle 2. Then, the second resin layer B formed of the second resin b and having a predetermined width is embedded in the first resin layer A formed of the first resin a, and the slit portion 8 is formed as shown in FIG. On the side, the thermoplastic resin sheet 9 having a three-layer structure is molded.

Here, in the state where the first resin a is supplied into the manifold 3 and is pushed out from the slit-shaped die orifice 6, the vector of the flow of the first resin a (the flow direction and flow velocity of the resin). ) Depends on the position in the manifold 3. The direction of the vector of the flow of the first resin a is a combination of the width direction of the manifold 3 and the sheet extrusion direction. Normally, on the inner side of the manifold 3, the component of the resin flow vector in the width direction of the manifold 3 is relatively large, and the component in the sheet extrusion direction is small. On the side of the land portion 7 of the manifold 3, the component of the resin flow vector in the width direction of the manifold 3 is small and the component in the sheet extrusion direction is large. In the land portion 7, there is almost no resin flow in the width direction of the manifold 3, and only resin flow in the sheet extrusion direction exists.

On the other hand, the second part sent out from the slit part 8
The resin b flows out in the feeding direction (almost the sheet pushing direction). As described above, since the vector of the flow of the first resin a has the flow component in the width direction of the manifold 3, the first resin of the second resin b depends on the position of the slit portion 8.
The influence of the resin a is different.

For example, the second resin b extruded from the base portion 8b of the slit portion 8 becomes less susceptible to the flow of the first resin a in the width direction, and the second resin b extruded from the tip portion 8a of the slit portion 8 is It is greatly affected by the widthwise flow of the first resin a. Therefore, the cross-sectional shape of the thermoplastic resin sheet 9 immediately after being extruded from the slit portion 8 has a second resin layer B having a cross-sectional shape similar to the shape of the slit portion 8 as shown in FIG. Thus, the cross-sectional shape of the thermoplastic resin sheet 9 extruded from the die orifice 6 has a second resin layer B having a gradation portion formed at the front end as shown in FIG. 5B. ..

Examples of the first resin a or the second resin b used in the present invention include polyethylene, polypropylene, polystyrene, polycarbonate, vinyl chloride resin, nylon resin, polyvinyl acetal, acrylic resin, acetal resin, polyester resin and the like. Can be given. A plasticizer, a filler and the like may be added to these thermoplastic resins.

It is sufficient that the first resin a and the second resin b are different thermoplastic resins. For example, a transparent thermoplastic resin is used as the first resin a, and a pigment is added to the first resin as the second resin b. It is also possible to use one in which a coloring agent such as a dye is mixed, or to use the first resin a and the second resin b having different optical refractive indexes. Further, the shape of the slit portion 8 can be variously changed according to the use and purpose.

[0028]

[Operation] The insert nozzle is supported in a cantilever manner in the manifold, and a slit portion which is long in the lateral direction is formed in the slit portion, and the opening edge of the tip portion of the slit portion is compared with the opening edge of the base portion of the slit portion. The second resin pushed out from the slit portion by being positioned on the inner side of the manifold is
Since the influence of the lateral flow from the first resin gradually increases from the base to the tip of the slit, it is possible to manufacture a thermoplastic resin sheet in which the end of the first resin layer is unclear.

That is, since the base of the slit and the tip of the slit have different positions in the depth direction in the manifold, the base of the slit is less affected by the lateral flow of the first resin, and the tip of the slit is smaller. In the portion, the influence of the lateral flow of the first resin is large. As a result, the width dimension of the tip portion of the resin layer formed of the second resin extruded through the slit portion is widened and the thickness thereof is gradually reduced to form a second resin layer having a very thin tip portion. It

[0030]

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

Example 1 A thermoplastic resin sheet was extruded under the following conditions using the apparatus shown in FIGS.

<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 Length of land 7: 50 mm Clearance of land 7: 0.5 mm <Shape of insert nozzle> FIGS. 3 (a) and 4
In (a), the dimensions of each part are as follows. L1
= 200mm, L2 = 50mm, L3 = 5mm, L4 = 40mm,
L5 = 28mm, H = 2.2mm.

<Extrusion conditions> Extruded resin amount ratio: transparent resin: colored resin = 10: 1 Resin temperature: transparent resin: 170 ° C, colored resin: 170 ° C Type of resin used: transparent resin: polyvinyl butyral resin Colored resin: polyvinyl Butyral resin (colored with dye) The width dimension of the colored band and the color ratio of the colored band portion of the obtained thermoplastic resin sheet were measured, and the relationship therebetween is shown in FIG. 8 (indicated by ● in FIG. 8).

The color ratio was calculated by the following formula.

Color ratio = b / (2a + b) However, as shown in FIG. 6, a represents the thickness dimension of the transparent resin layer A formed of the transparent resin, and b represents the thickness dimension of the colored band B.

Example 2 A thermoplastic resin sheet was extruded under the same conditions as in Example 1 except that the insert nozzle was moved to the 50 mm die adapter side and fixed.

The width dimension of the colored band and the color ratio of the colored band portion of the obtained thermoplastic resin sheet were measured and the relationship therebetween is shown in FIG. 8 (indicated by □ in FIG. 8).

From this result, by changing the mounting position of the insert nozzle 2, the width of the colored band changes,
In addition, it was confirmed to have a gradation part.

Comparative Example A thermoplastic resin sheet was extruded under the same conditions as in Example 1 except that the insert nozzle 12 shown in FIG. 7 was used.

<Shape of Insert Nozzle> In FIG. 7, the dimensions of each part are as follows. L11 = 200mm,
L14 = 40 mm, L15 = 28 mm, gap H between slits 13
= 2.2 mm.

The width dimension of the colored band and the color ratio of the colored band portion of the obtained thermoplastic resin sheet were measured and the relationship therebetween is shown in FIG. 8 (indicated by ◯ in FIG. 8).

From these results, it was confirmed that the gradation portion was not formed when the conventional insert nozzle was used.

In addition, Table 1 summarizes the width dimensions of the colored bands of the thermoplastic resin sheets obtained in Examples 1 and 2 and Comparative Example, the state of the gradation portion, and whether or not the boundary portion is clear.

[0045]

[Table 1]

[0046]

According to the present invention, it is possible to manufacture a thermoplastic resin sheet in which the boundary between the end of the second resin layer and the first resin layer is unclear by utilizing the flow of the mainstream resin. , For example, in the manufacture of an antiglare interlayer film used for a windshield of an automobile, it is possible to increase the commercial value by making the boundary of the end portion of the colored band unclear to reduce the gradation density in gradation. .. By thus forming the gradation thickness of the colored band, it is possible to obtain the aesthetic appearance of the boundary portion of the colored band of the intermediate film SDF.

Further, by using an insert nozzle having an appropriate shape, the thickness of a single sheet molding die can be adjusted by the balance between the effect of the inner deckle and the amount of the second resin extruded from the slit portion. A multilayer sheet can be easily obtained without need. Further, even if a single resin is extruded by removing the insert nozzle, a sheet having a uniform thickness can be obtained without adjustment.

[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 (a) and 3 (b) are cross-sectional views of a main part of another embodiment of the insert nozzle.

FIG. 4A is a sectional view of an insert nozzle.
(B) is sectional drawing of other Examples of an insert nozzle.

FIG. 5A is a sectional view of a main part of the thermoplastic resin sheet at a slit portion. FIG. 3B is a cross-sectional view of a main part of the thermoplastic resin sheet at the die orifice.

FIG. 6 is a sectional view of a main part of a thermoplastic resin sheet.

FIG. 7 is a sectional view of a main part of an insert nozzle used in a comparative example.

FIG. 8 is a graph showing the relationship between the widthwise dimension of the colored bands and the color ratio of the thermoplastic resin sheets obtained in Examples 1 and 2 and Comparative Example.

[Explanation of symbols]

 1 Extrusion Mold 2 Insert Nozzle 3 Manifold 4 First Resin Supply Channel 5 Second Resin Supply Channel 6 Slit Die Orifice 7 Land 8 Slit 9 Thermoplastic Resin Sheet 11 Die Adapter 15 Side Plate 16 Side Plate a First Thermoplastic resin b Second thermoplastic resin A First resin layer B Second resin layer

Claims (1)

[Claims] 1. A first resin layer formed of a first thermoplastic resin and a second resin layer embedded in the first resin layer and having a predetermined width formed of a second thermoplastic resin. A device for producing a thermoplastic resin sheet having a resin layer, the device comprising an extrusion molding die and an insert nozzle, the extrusion molding die being supplied with a first thermoplastic resin. , A first resin supply path for supplying the first thermoplastic resin into the manifold, and a slit shape in which the first thermoplastic resin is extruded from the manifold to form the first resin layer. A die orifice, and a land portion provided between the manifold and the slit-shaped die orifice, the insert nozzle is disposed in the manifold, and its base is cantilevered in a mold. Supported by the insert nozzle The second resin supply passage to which the second thermoplastic resin is supplied, and the slit portion that is long in the lateral direction and opens in the manifold, and the opening edge of the front end of the slit portion are provided. Is a device for manufacturing a thermoplastic resin sheet, which is located on the far side of the manifold from the opening edge of the base of the slit portion.