JP2010280157A - Extrusion molding mold and extrusion molding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold and an extrusion molding method for executing extrusion molding of a resin film that prevent the interface shape between resins constituting a resin laminate from being largely distorted, allow the width of a resin layer at the end of the resin laminate to be continuously changed, prevent foreign matter or the like from being mixed in the resin film, and are rich in recyclability and convenience. <P>SOLUTION: An extrusion molding mold is configured as follows. Resin introduction parts 31, 32 are provided on the same end side of a mold 10. A resin supplied from each resin introduction part continuously flows from the end side to the lip-opening 14 side inside a manifold 12. Each resin forms a region for each resin in a direction orthogonal to the resin flow direction. There is provided an extrusion molding technique, using the extrusion molding mold, for a resin film or a resin sheet that prevents the interface shape between resins constituting a resin laminate from being largely distorted, allows the width of a resin layer at the end of the resin laminate to be continuously changed, prevents foreign matter or the like from being mixed in the resin film or in the resin sheet, and is rich in recyclability and convenience. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to the production of a resin laminate, and more particularly to a mold used in extrusion molding.

In general, when a film or sheet is formed by extrusion, there is a problem that a neck-in phenomenon occurs.
Here, the neck-in phenomenon means that the width of the produced film or sheet is reduced at the die outlet due to the shrinkage in the width direction that occurs when the resin extruded in the molten state is stretched in the flow direction by its own weight or take-off. This phenomenon is narrower than the width.

  When the neck-in phenomenon occurs, wrinkles occur on the end side of the generated resin laminate or the thickness on the end side becomes non-uniform, so that both ends of the formed film or sheet are defective areas. It may be excised.

In addition, when a film or sheet is formed by extrusion molding, when a resin unstable to heat, such as heat deterioration, is used, the resin extruded from the end of the mold has a residence time in the mold. There is a problem that the resin composition at both ends is long.
Because of such problems and stretching, the both ends of the molded resin film may be cut off for the convenience of subsequent processes.

Therefore, there is a method to reduce the economic burden at the time of excision by placing inexpensive resin such as recycled resin on both ends of the resin film and molding the area to be excised with inexpensive resin or resin that is easy to recycle. It is done.
In addition, when a film or sheet is formed using a resin that is easily deteriorated by heat, the resin film is multilayered in the width direction, and a resin that is not easily deteriorated by heat is disposed on the end side of the resin film. A method for stabilizing the forming of the sheet is conceivable.

  As a technique for multilayering such a resin film in the width direction, there are inventions disclosed in Patent Documents 1 and 2.

Here, the invention disclosed in Patent Document 1 is provided with a feed block for merging the resin at the upper part of the mold, and by changing the feed block to be used according to the resin to be used, the resin and end of the central part are changed. This is an apparatus or method for stabilizing the resin interface of the part.
Furthermore, in the invention disclosed in Patent Document 2, a portion for adjusting the width of the flow path is provided inside the mold, and the width of the flow path is determined to flow the resin. Is a method of reliably laminating at a desired width.

JP 2004-181753 A JP-A-7-76038

  However, as in the invention disclosed in Patent Document 1, when the feed block (flow path) is changed in accordance with the production conditions such as the type of resin, the shape of the boundary line between the resin at the end and the other resin is changed. Although it can be stabilized, there is a problem in that it is not convenient because cleaning and measures against foreign matter are required every time the flow path is changed.

Then, as in the invention disclosed in Patent Document 2, when a portion for adjusting the width of the flow path is provided inside the mold and is slid, the resin is changed when the width of the end is changed during production. In some cases, the product burns and foreign matter is mixed into the product.
In addition, as shown in Comparative Example 1 described later, there is a problem that it is difficult to control the thickness when the width of the end portion is widened.
In addition, there is a problem that the structure of the mold becomes complicated and expensive.

  Therefore, the present invention is capable of continuously changing the width of the resin layer at the end without greatly distorting the interface shape between the resins constituting the resin laminate, and is less likely to be contaminated with foreign matters. Another object of the present invention is to provide a resin film extrusion technique that is highly convenient.

  In order to solve the above-mentioned problems, the invention according to claim 1 is an extrusion mold having an opening for extruding a molten resin into a sheet or a film, and the molten mold is formed in the mold. In an extrusion mold having a resin introduction part for introducing resin and a manifold part for widening the flow of molten resin, the resin introduction part communicates with the manifold part. And at least one of the resin introduction portions is a main resin introduction portion that supplies main resin to the center side of the manifold portion, and at least one of the resin introduction portions has an auxiliary resin in the width direction of the manifold portion. An extrusion molding die characterized in that it is an auxiliary resin introduction portion supplied to the side portion side.

  In the extrusion mold according to the present invention, since two or more resin introduction portions on the upstream side of the resin flow are provided, it is possible to introduce separate resins into the mold from the respective introduction portions. Therefore, it is easy to adjust the introduction speed and introduction amount of the introduced resin for each resin. Furthermore, a main resin introduction part that supplies main resin to the center side of the manifold part and an auxiliary resin introduction part that supplies auxiliary resin to the side part side of the manifold part are arranged. Therefore, it is easy to join each introduced resin at the manifold part, and when the joined resin flows, it is possible to form a region (layer) of each resin in the width direction of the mold. is there.

  The invention described in claim 2 assumes an imaginary line that is perpendicular to the direction of extrusion of the resin to the outside of the mold and is a half straight line from the connection position of the auxiliary resin introduction part toward the main resin introduction part, 2. The extrusion according to claim 1, wherein the auxiliary resin introduction portion is connected to the manifold portion so that an angle formed by a connection direction between the virtual line and the auxiliary resin introduction portion is greater than 0 degree and equal to or less than 120 degrees. This is a molding die.

  In the mold for extrusion molding of the present invention, the joining angle when the resin joins is greater than 0 degree and 120 degrees or less. Therefore, the joining between the resins is performed smoothly, and the resin flow can be stabilized.

  The invention described in claim 3 has three or more resin introduction portions, and two of the resin introduction portions are auxiliary resin introduction portions that supply auxiliary resin to both sides of the manifold portion, respectively. The extrusion mold according to claim 1 or 2, wherein the mold is for extrusion molding.

  In the extrusion mold according to the present invention, both ends of the resin laminate can be formed of an inexpensive resin or a resin that is easy to recycle, so that the production cost when both ends are cut when the resin laminate is produced is further reduced. be able to.

  The invention described in claim 4 is an extrusion molding method in which a main resin and an auxiliary resin are introduced into the extrusion mold according to any one of claims 1 to 3, which is introduced into the manifold portion. In addition, the tangent line of the interface between the main resin and the auxiliary resin in the vicinity of the auxiliary resin introduction portion is orthogonal to the extrusion direction of the resin to the outside of the mold and from the connection position of the auxiliary resin introduction portion to the side portion side. This is an extrusion molding method characterized by adjusting the introduction amounts of the main resin and the auxiliary resin so that the angle formed with the phantom line which is a half straight line exceeds 0 degree and becomes 90 degrees or less.

In the extrusion molding method of the present invention, each resin introduced into the mold from two or more resin introduction portions upstream of the resin flow is in the width direction of the mold (perpendicular to the extrusion direction of the resin out of the mold). In the direction where the resin flows). In the joined resin, one resin (for example, a resin that forms the central portion) flows toward the lip opening, and the other resin (for example, a resin that forms the end portion) flows along the flow. As a result, regions in which the respective resins flow are formed in the mold, and regions (layers) made of the respective resins are formed in the width direction of the mold in the extruded resin laminate.
As a result, the position of the boundary line between the joined resins is determined by the ratio of the flow rates of the respective resins constituting the resin laminate (for example, between the resin forming the central portion and the resin forming the end portion). In order to change the width of the resin layer at the end, there is no need to change the position or angle of the flow path. Moreover, since the width | variety of the resin layer of an edge part can be changed continuously by changing the ratio of the introduction amount of each resin, it is highly convenient. Further, since the shape of the resin flow path in the mold is not complicated, the joining interface is not greatly distorted. Furthermore, since there is no mechanism such as a sliding part, the problem of foreign matter contamination due to resin scorching is reduced.

  According to the present invention, it is possible to continuously change the width of the resin layer at the end without greatly distorting the interface shape between the resins constituting the resin laminate, and there is little problem of contamination such as foreign matters. It is possible to provide a mold and an extrusion molding method for carrying out extrusion molding of a resin film or a resin sheet rich in properties and convenience.

It is a perspective view of the metal mold | die in 1st embodiment of this invention. It is a perspective view which shows the internal space of the metal mold | die in 1st embodiment of this invention. It is a front view which shows the state which poured resin into the internal space of the metal mold | die of FIG. It is an enlarged view of the junction part of the metal mold | die of FIG. It is explanatory drawing when resin extruded from the metal mold | die is shape | molded. It is a perspective view which shows the internal space of the metal mold | die in 2nd embodiment of this invention. It is a front view which shows the state which poured resin into the internal space of the metal mold | die of FIG. It is a perspective view which shows the internal space of the metal mold | die in 3rd embodiment of this invention. It is a front view which shows the state which poured resin into the internal space of the metal mold | die of FIG. It is a perspective view which shows the internal space of the state which changed the position of the main resin introduction part of the metal mold | die of FIG. It is a perspective view which shows the internal space of a metal mold | die when not providing an auxiliary resin introduction part in the upstream of the flow of resin.

  Hereinafter, specific embodiments of the present invention will be described. The mold 10 (extrusion mold) in the first embodiment of the present invention has an internal space 11 as shown in FIGS. Then, the resin passes through the internal space 11 and molding is performed. More specifically, the resin (main resin 40, auxiliary resin 41) introduced into the mold 10 spreads in the width direction at the manifold portion 12 provided in the internal space 11, passes through the land portion 13, and then opens the lip. The laminated sheet 91 is extruded from the portion 14.

As shown in FIGS. 1 and 2, the mold 10 includes an internal space 11, a manifold portion 12, a land portion 13, a lip opening portion 14, a resin introduction portion 31 (main resin introduction portion), and a resin introduction portion 32 (auxiliary resin). Introduction part) is provided. More specifically, resin introduction portions 31 and 32 are arranged on the upstream side of the internal space 11 (upper side in FIG. 2 in the resin flow direction S), and the land portion 13 faces the resin introduction portions 31 and 32. An opening (not numbered) through which resin can be extruded is provided. The shape of the internal space 11 excluding the resin introduction portions 31 and 32 is a substantially rectangular parallelepiped shape, and the resin introduction portions 31 and 32 protrude so as to protrude upstream from the substantially rectangular parallelepiped portion. Is provided.
In addition, although the metal mold | die 10 of this embodiment is comprised from the at least 2 metal mold | die piece similarly to the normal thing, the line which shows the boundary of each metal mold | die piece is abbreviate | omitted in FIG. The outer shape of the mold 10 is the same as a general extrusion mold.

The manifold portion 12 is a space where the resin that has entered from inlets 31a and 32a, which will be described later, spreads in the width direction (direction indicated by W in FIG. 2). Specifically, as shown in FIG. 2, the space is surrounded by a front surface 12a, side surfaces 12b and 12c, an upper surface 12d, a lower surface 12e, and a back surface 12f.
Here, the upper surface 12d is a surface that forms at least the upstream side where the resin introduction portion 32 is provided, and the lower surface 12e is a surface that forms the downstream side where an opening for sending resin to the land portion 13 is provided. is there. Furthermore, the front surface 12a is a surface on the near side in FIG. 2 and is a surface extending in the width direction W direction. The back surface 12f has the same shape as the front surface 12a and is a surface provided at a position facing the front surface 12a. The side surfaces 12b and 12c are surfaces arranged at positions where the upper surface 12d and the lower surface 12e are connected to each other on the end side in the width direction.
And since the lower surface 12e vicinity of the manifold part 12 is restrict | squeezed according to the inlet (not numbered) of the land part 13, it is thin compared with another part. (The distance from the front surface to the back surface in the thickness direction T in FIG. 2 becomes shorter as the land portion 13 is approached.)
The manifold portion 12 has an introduction portion 33 and a merging portion 34. Here, the introduction part 33 is a part where the resin introduction part 31 is connected to the manifold part 12, and the joining part 34 is where the resin introduced from the resin introduction part 31 and the resin introduced from the resin introduction part 32 merge. Part.

  The land portion 13 is a flow passage having a rectangular cross section, and guides the resin developed in the width direction by the manifold portion 12 to the lip opening portion 14.

  The lip opening 14 is an opening for discharging the molded resin, and shapes the molded product.

The resin introduction part 31 (main resin introduction part) and the resin introduction part 32 (auxiliary resin introduction part) are square columnar spaces (passages), and introduction ports 31a and 32a are arranged at one end respectively. The other end is connected to the manifold portion 12. The position where the resin introduction part 31 is connected is near the center in the width direction W of the manifold part 12.
The introduction ports 31a and 32a are individually connected to an apparatus installed for the purpose of laminating resins such as an extruder and a feed block, and the main resin 40 constituting the resin laminate can be introduced from the introduction port 31a. The auxiliary resin 41 can be introduced from the introduction port 32a.
The introduction port 31a has a larger diameter (area) than the introduction port 32a, and the resin introduction part 31 can introduce a larger amount of resin than the resin introduction part 32.

Next, a method for manufacturing a sheet, a film, and the like using the mold 10 according to the first embodiment of the present invention will be described.
First, the main resin 40 and the auxiliary resin 41, which are molten resins, are respectively introduced from an extruder (not shown) or a member (not shown) such as a nozzle or a feed block connected to the extruder, It introduces into the introduction port 32a.

  Here, the main resin 40 and the auxiliary resin 41 used in this embodiment are thermoplastic resins, and specifically, ultra-low density polyethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, High density polyethylene, ethylene vinyl chloride copolymer, polyvinyl alcohol, polyvinyl butyral, ethylene vinyl acetate copolymer, ethylene ethyl acrylate, polyvinyl acetate, polypropylene, polybutene, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polystyrene, maleimide, polysulfone, polyethersulfur A thermoplastic resin such as phon, polyvinylidene fluoride, poly (meth) acrylate, cellulose ester, polynorbornene, or the like can be used. In addition, additives, such as a plasticizer and a ultraviolet absorber, may be added to the thermoplastic resin, and resins other than those described above may be used.

  Each resin introduced from the inlet 31a and the inlet 32a flows through the resin inlets 31 and 32, respectively. Then, the resin that has passed through the resin introduction part 31 flows through the manifold part 12 and spreads in the width direction (left and right direction in FIG. 3), and collides with the resin that has passed through the resin introduction part 32 at the junction part 34 and each resin is Join.

  Here, it is desirable that the merging portion 34 be in the vicinity of the upper surface 12d of the manifold portion 12 (upper side in FIG. 3). If the main resin 40 is introduced from the upper surface 12d and the auxiliary resin 41 is introduced into the manifold portion 12 from the rear surface 12f as shown in FIG. 11, the main resin 40 may be covered by the auxiliary resin 41 or the main resin 40 may be covered. The flow of the auxiliary resin 41 may be hindered. This is because the joining interface 35 may be greatly distorted or the auxiliary resin 41 may not flow to the end of the resin laminate (laminated sheet 91).

As described above, the joining portion 34 is desirably on the side opposite to the side connected to the land portion 13 of the manifold portion 12, but the position in the width direction W is not particularly limited. However, it is necessary to join the auxiliary resin 41 so as to follow the flow of the main resin 40 in the manifold portion 12.
Therefore, as shown in FIG. 4, the angle C formed by the tangent line E of the merging interface 35 and the virtual line D (hereinafter referred to as the merging angle) is desirably 90 degrees or less, and more desirably 60 degrees or less. .
This is because if the angle of merging is too large, the force applied by the flow of the auxiliary resin 41 to the flow of the main resin 40 becomes larger than necessary, causing the merging interface 35 to be disturbed.
In addition, as shown in FIG. 5, it is desirable that the distance W1 from the end of the manifold portion 12 to the joining portion 34 is larger than the width W2 of the end of the resin laminate (laminated sheet 91). This is because, if W1 is smaller than W2, it is necessary to cause the flow of the auxiliary resin 41 to push back the flow of the main resin 40, so that it is difficult to adjust the introduction amount and viscosity of each resin.

Regions formed by the auxiliary resin 41 are formed along the boundary lines of the regions formed by the main resin 40 in the respective resins that have collided with each other at the merge portion 34, and each resin is directed toward the land portion 13. Flowing. That is, the flow by the auxiliary resin 41 is pushed by the flow by the main resin 40 and flows on the side of the manifold portion 12. (The auxiliary resin 41 is swept away toward the end of the manifold portion 12.) In this embodiment, the side portion of the manifold portion 12 refers to the space near the upper surface 12d and the side surface 12b of the manifold portion 12. Point to.
More specifically, the main resin 40 introduced into the manifold portion 12 spreads in the width direction W (FIG. 2) and collides with the auxiliary resin 41 introduced from the introduction port 32a.
Here, since the main resin 40 and the auxiliary resin 41 are respectively extruded from an extruder (not shown), the downstream direction (the downward direction of the resin flow direction S in FIG. 2) and the width direction W are respectively provided. In the direction of spreading in the direction of the thickness of the manifold portion 12 (thickness direction T in FIG. 2). That is, it tries to fill the manifold portion 12. Therefore, the flow by the main resin 40 and the flow by the auxiliary resin 41 are pressed against each other. However, since the introduction amount of the main resin 40 is larger than that of the auxiliary resin 41, the flow of the auxiliary resin 41 is pushed to the side by the flow of the main resin 40, so that the auxiliary resin 41 is in the manifold portion 12. Flowing on the side of the. Then, the flow by the main resin 40 and the flow by the auxiliary resin 41 flow in the downstream direction while pushing against each other in the width direction W and are pushed out to the land portion 13.

Each resin extruded to the land portion 13 passes through the land portion 13 and is discharged as a laminated sheet 91 from the lip opening 14.
At this time, while the flow from the manifold portion 12 to the land portion 13 is continued, the forces pushing each other in the width direction W are gradually balanced and stabilized, so that the interface of the resin region is stabilized.

Then, as shown in FIG. 5, the discharged laminated sheet 91 is cut off at the end by a conventionally known cutter 92 and wound while being cooled by a winder 93. That is, manufacturing is completed by cooling the discharged laminated sheet 91 and stretching it as necessary or winding it into a film or sheet.
Here, the cooling and winding means can be executed by any means. For example, the laminated sheet 91 may be cooled with a chill roll while roll-stretching, or the resin laminate may be pressed against the chill roll using an air knife, a touch roll, or electrostatic pinning. It may be immersed in a water tank and cooled.

  As described above, when the mold 10 according to the present embodiment is used, the merging is performed smoothly at the merging portion 34, and the auxiliary resin 41 after the merging flows to the end portion of the manifold portion 12, and the end portion of the resin laminate is used. Can be formed. Further, if the joining portion 34 is provided in the width direction W in advance from the maximum width of the resin laminate, the end portion of the resin laminate can be obtained only by changing the flow ratio of the auxiliary resin 41 and the main resin 40 even during production. The width of can be changed. Further, since the flow does not become complicated after the auxiliary resin 41 joins, the joining interface 35 is not greatly distorted. Further, since the mold 10 does not have a sliding part like the mold disclosed in Patent Document 2 or a complicated mechanism, there are few troubles such as scorching of resin due to the operation of the sliding part.

Moreover, when the main resin introduction part and the auxiliary resin introduction part are open on the same end side as in the mold 10 of the present embodiment, it is possible to ensure a long distance from each resin introduction part to the opening part. it can. As a result, when the resin flows toward the opening, the unstable interface at the joining portion becomes parallel and linear to the resin flow direction, and the interface is more reliably stabilized in a straight state. .
Specifically, at the junction, the main resin and the auxiliary resin collide with each other, and the flow of each resin interferes with the flow of the other resin, so that the junction interface becomes unstable. However, as each resin flows toward the opening and the force exerted by the resin flow on the other resin flow is balanced, the merge interface is linear and parallel to the resin flow direction. It is easy to be in a state. Therefore, it becomes easy to make the cut width of the produced resin film or resin sheet constant.

And there exist the following as an embodiment which changed only resin introduction parts, such as resin introduction part 32, etc. to metallic mold 10 in a 1st embodiment, and laminate sheet 91 is fabricated using these. be able to.
In these embodiments, the auxiliary resin 41 is laminated on the end side in the width direction of the main resin 40 as in the first embodiment.
In the following description, unless otherwise specified, the same structure as that of the mold 10 in the first embodiment is denoted by the same reference numeral and description thereof is omitted.

In the mold 20 (extrusion mold) in the second embodiment of the present invention, as shown in FIGS. 6 and 7, the resin introduction part 32 is bent in the vicinity of the manifold part 12, The merging angle (the angle at which the auxiliary resin 41 is introduced) is adjusted.
The angle A at which the manifold portion 12 and the resin introduction portion 32 merge is in the range of more than 0 degrees and 120 degrees or less.
As a result, the smoother main resin 40 and auxiliary resin 41 are merged at the merge portion 34, and the merge interface 35 is further less likely to be distorted, enabling stable production.
Here, the resin introduction part 32 is preferably bent so that A is 10 degrees or more and 90 degrees or less, and more preferably is bent so that A is 30 degrees or more and 60 degrees or less. desirable. This is because if the angle A is too small, the resin is clogged in the resin introduction portion 32, or the resin accumulated near the corner of the end of the manifold portion 12a (the corner of the upper end formed by the side surface 12b and the upper surface 12d) hardly flows. Problems are likely to occur. On the other hand, if the angle A is too large, the flow of the auxiliary resin 41 presses the flow of the main resin 40 more than necessary, and the merging interface 35 is not stabilized.

The mold 21 (extrusion mold) in the third embodiment of the present invention has three resin introduction portions 31, 32, and 36, as shown in FIGS. The resin introducing portions 32 and 36 are bent toward the side of the manifold portion 12 near the manifold 12.
Then, the main resin 40 and the auxiliary resin 41 are merged at the merge portion 34, and the auxiliary resin 42 introduced into the resin introduction portion 36 (auxiliary resin introduction portion) is merged at the main resin 40 and the merge portion 37. Further, the merging angle A between the resin introduction part 32 and the manifold part 12 for forming the merging part 34 and the merging part 37 and the merging angle B between the resin introduction part 36 and the manifold part 12 are both greater than 0 degree and 120 degrees. It is in the following range.
Thereby, the auxiliary resins 41 and 42 can be laminated on both ends of the main resin 40. Therefore, even in the case of molding in which both ends of a film or sheet molded with a mold must be cut off, the recyclability can be further improved by using the mold 21 of the third embodiment of the present invention. .

Next, experiments conducted for confirming the effects of the present invention will be described.
In Examples and Comparative Examples, multilayer molding was performed in the width direction inside the mold, and the resin that came out of the mold was taken up by a chill roll. And the thickness distribution of this molded article and the shape of the merged interface were evaluated.

  In the above-described embodiment, the shapes of the internal spaces of the molds 10, 20, and 21 (the shapes of the manifold portion 12, the land portion 13, and the lip opening portion 14) are generally used shapes. The shape of the internal space is not limited to this. A shape like a so-called coat hanger die or a shape like a straight manifold die may be used. The point is that the resin to be laminated in the manifold portion 12 can be merged, laminated by the flow of the resin, and the resin may flow to the lip opening 14 in the laminated state.

In the above-described embodiment, the resin introduction part 31 (main resin introduction part) is provided on the upper surface 12d of the manifold part 12. However, the position where the resin introduction part 31 is provided is not limited to this, and the drawings of the front surface 12a and the back surface 12f. 2 may be provided on the upper side.
If it demonstrates concretely, as shown in FIG. 10, you may provide the resin introduction part 31 in the back surface 12f side, for example.
In short, when the main resin 40 and the auxiliary resin 41 collide with each other in the manifold portion 12, a region formed by the auxiliary resin 41 is formed along the boundary line of the region formed by the main resin 40. In addition, each resin may flow toward the land portion 13 together.

  In the above-described embodiment, all of the resin introduction portions 31, 32, and 33 are provided so as to protrude from the manifold portion 12, and each has an introduction port. However, the shape of the resin introduction portion is not limited to this. Absent. For example, an opening may be provided directly in the manifold part, and resin may be introduced into the manifold part therefrom. That is, the resin introduced in the manifold section 12 of the mold to be used can be merged, and the other resin only needs to flow along the flow of one resin.

Example 1
A two-layer film in the width direction of Example 1 was molded using the mold 20 shown in FIGS. The mold width was 1700 mm, and the position of the merging portion 34 was 250 mm from the end of the manifold portion.
Further, the extrusion amount, which is the amount of resin to be supplied, is kept constant at 80 kg per hour without changing the total extrusion amount, and the ratio of the main resin 40 and the auxiliary resin 41 is changed. The width was changed to 40 mm, 80 mm, and 120 mm.
As the main resin 40 and the auxiliary resin 41, polyvinyl butyral (PVB) was adopted, and the zero shear viscosity was 2000 Pa · s.
The shear viscosity was measured with a mechanical spectrometer (RMS800) manufactured by Rheometric Scientific F.E., and the shear viscosity at a shear rate of 0.05 / s was defined as zero shear viscosity.

(Comparative Example 1)
The test was performed under the same conditions as in Example 1 except that the conventional merging method in the mold described in Patent Document 2 was used.
The same mold was used at 1700 mm, and the same manifold shape and land shape were used.

  Table 1 shows whether the thickness of the two-layer film formed in Example 1 and Comparative Example 1 varies depending on the width of the end portion in the width direction, and whether the shape of the merged interface is good or bad.

  As shown in Table 1, although the thickness of the two-layer film of Example 1 was not varied and the shape of the merged interface was not disturbed, the thickness of the two-layer film of Comparative Example 1 was increased when the end resin width was 120 cm. A variation occurred.

  From the above, it was shown that by using the mold 20 of the present embodiment, a sheet or film having a uniform thickness at the end of the width direction laminated sheet (two-layer film) to be generated can be generated.

10, 20, 21 Mold (mold for extrusion molding)
11 Internal space 12 Manifold part 13 Land part 14 Lip opening part 31 Resin introduction part (main resin introduction part)
31a Introduction port 32, 36 Resin introduction part (auxiliary resin introduction part)
32a, 36a Inlet 35 Merge interface 40 Main resin 41, 42 Auxiliary resin

Claims (4)

An extrusion mold having an opening for extruding molten resin into a sheet or film, and introducing a molten resin into the mold, and widening the flow of the molten resin An extrusion mold in which the resin introduction portion communicates with the manifold portion.
There are two or more resin introduction parts, and at least one of the resin introduction parts is a main resin introduction part that supplies main resin to the central side of the manifold part, and at least one of the resin introduction parts is auxiliary An extrusion molding die, which is an auxiliary resin introduction portion that supplies resin to a side portion in the width direction of the manifold portion.   Assuming an imaginary line that is orthogonal to the direction of extrusion of the resin to the outside of the mold and that is a semi-straight line from the connection position of the auxiliary resin introduction part toward the main resin introduction part, the connection between the imaginary line and the auxiliary resin introduction part The extrusion molding die according to claim 1, wherein the auxiliary resin introduction portion is connected to the manifold portion so that the angle formed by the direction exceeds 0 degree and becomes 120 degrees or less.   2 or 3 or more, wherein two of the resin introduction portions are auxiliary resin introduction portions for supplying auxiliary resin to both sides of the manifold portion, respectively. 2. A mold for extrusion molding according to 2. An extrusion molding method carried out by introducing a main resin and an auxiliary resin into the extrusion mold according to any one of claims 1 to 3,
The tangent of the interface in the vicinity of the auxiliary resin introduction portion between the main resin and the auxiliary resin introduced into the manifold portion is orthogonal to the direction of extrusion of the resin out of the mold and from the connection position of the auxiliary resin introduction portion. Extrusion molding characterized by adjusting the amount of introduction of the main resin and the auxiliary resin so that the angle formed with the imaginary line that is a semi-straight line toward the side is more than 0 degree and not more than 90 degrees Method.

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