JP2010538859A - Extrusion mold and manifold for extrusion mold - Google Patents

Abstract

The present invention relates to an extrusion die for producing an extruded material of a thermoplastic resin material. The extrusion mold includes a mold outlet through which a melt flow of the thermoplastic resin is extruded, a supply side injection port that communicates with a supply side distribution unit that divides the thermoplastic resin material into the first part and the second part, A cross flow manifold. The crossflow manifold includes a first crossflow manifold portion that receives the first portion of the thermoplastic resin material, a second passage that communicates with the first passage, and a third passage that communicates with the second passage. It is equipped with.

[Selection] Figure 1

Description

  The present invention generally relates to an extrusion apparatus for producing a film or sheet of a thermoplastic resin.

  Extrusion molds are used in manufacturing processes that make a variety of products. For example, certain extrusion molds are used to form plastic materials into thin films, sheets, or extended shapes. Two or more different materials that make up separate molten layers (e.g., thermoplastic materials) are integrated in an extrusion mold under pressure to make up as a single laminate material A technique of melt lamination molding method including a process has been developed. Such a process uses laminar flow theory that allows two or more molten layers to be integrated under suitable operating conditions in a common flow path without being mixed at the contact interface. Such multi-layer extrusion systems have come to be used as a convenient method for forming multi-layer materials of the same or different materials of molten polymer.

  Various extrusion dies have been made from molten polymers for extruding multilayer films. A common form of such an apparatus is one that uses a first mold part that integrates layers of various materials. The integrated material is then planarized and extruded through the second mold part. An example of such a type of device is disclosed in US Pat. No. 5,316,703, which is hereby incorporated by reference in its entirety. When manufacturing a multilayer sheet or a multilayer film, there is a demand for having a uniform thickness in the width direction or the lateral direction (TD) of the extruded sheet. There was a limit to the effectiveness of the device.

  The mold assembly for extruding the molten polymer can be modularized and is typically assembled from multiple parts, forming a mold station as an integrated device. For example, the mold assembly can be composed of a first mold part and a second mold part. The first mold part and the second mold part constitute a component that allows fluid to be taken into the mold assembly and further pushed out of the mold assembly. The first mold part is provided with a first mold lip part, and the second mold part is provided with a second mold lip part. A feed gap (gap for extruding the molten polymer) that determines the thickness of the fluid film extruded from the mold assembly is formed between the first and second mold lip portions.

  The central feed type extrusion die is generally used in today's resin industry association. The flow of molten polymer entering the manifold branches and, as a result of the branching, is divided into tributaries that flow in opposite directions towards the ends of the manifold. Each tributary flows from the center of the manifold to each end of the manifold, resulting in a pressure drop.

  Typically, a central feed extrusion mold is a teardrop-like flat manifold (which may be in the form of a coat hanger manifold), a tail fin manifold, or T A mold manifold is provided. In order to overcome the pressure drop and ensure that the flow volume is substantially uniform over the entire width of the flow, this type of mold is provided with a transition region flow path to compensate for fluid pressure. Further, it is known that the extrusion die of the center feed type includes a flow path in a transient region for compensating for a two-stage fluid pressure. Such devices are exemplified in U.S. Patent No. 4,372,739 (Vetter et al.) And U.S. Patent No. 5,256,052 (Cloeren).

  The mold assembly for extruding the molten polymer can be a fixed extrusion gap or a flexible extrusion gap. In the case of a fixed extrusion gap, the mold lip portions do not move relative to each other, and the thickness dimension of the extrusion gap is always the same. In the case of a flexible extrusion gap, in order to be able to adjust the thickness dimension of the flexible extrusion gap over the width direction of the mold assembly, the mold lip on one side is connected to the mold lip on the other side. It can be moved relative to the part. Generally, the flexible extrusion gap is such that the first mold part is flexible between the rear part and the front part of the first mold part (the first mold lip part comes into contact with this part). This is realized by assembling the first mold part so as to have a web part. The flexible extrusion gap is also realized by means for moving the front part of the first mold part in a local region. By moving the front part, the mold lip part is adjusted relative to the other mold lip part, so that the thickness of the extrusion gap in the desired local area is adjusted. become.

  By utilizing a flexible extrusion gap, a conventional mold assembly design usually allows local adjustment of the extrusion gap to adapt to specific operating conditions. However, once the adjustment is made for the first time (i.e., the movable lip has moved from its initial position), it is easy to say that it is possible to return the lip to the known base position. Not that. Also, it is difficult to adjust the extrusion gap of a standard flexible mold used in the industry without using a clean mold and special equipment, and to adjust to a known high-precision gap dimension. is there.

  With respect to the production of special films such as microporous polyolefin membranes, there are additional requirements in the design of extrusion dies for producing such films. Microporous polyolefin membranes are primary batteries, lithium ion secondary batteries, lithium polymer secondary batteries, nickel / hydrogen secondary batteries, nickel / cadmium secondary batteries, nickel / zinc secondary batteries, silver / zinc secondary batteries. It is useful as a separator for secondary batteries such as batteries. When microporous polyolefin membranes are used as battery separators, especially when used as lithium ion battery separators, the performance of the membrane has a very strong impact on battery properties, productivity, and safety. Therefore, the microporous polyolefin film needs to have appropriately balanced permeability, mechanical characteristics, dimensional stability, shutdown characteristics, melting characteristics, and the like. Here, the term “balanced” means that optimizing one of these properties does not significantly degrade another property.

  As is well known, separators with a relatively low shutdown temperature and a relatively high melting temperature are required to improve battery safety, particularly for batteries that are exposed to high temperatures during use. Uniform dimensional characteristics, such as film thickness, are essential for high performance films. A separator having high mechanical strength is desirable for a high-performance battery assembly and a battery having high-performance reliability. In order to improve the characteristics of the microporous polyolefin film, it has been proposed so far to optimize the material composition, molding and stretching conditions, heat treatment conditions, and the like.

  In general, microporous polyolefin membranes are substantially composed of polyethylene (i.e., this material is composed solely of polyethylene without significant inclusion of other materials) and has a relatively low melting temperature. have. Therefore, in order to increase the melting temperature, a microporous polyolefin film made from a polymer solution containing a mixture of polyethylene and polypropylene resin and a multiporous microporous polyolefin film having a polyethylene layer and a polypropylene layer have been proposed. . Using a polymer solution containing a mixture of such resins, or producing a multi-layered film with different polyolefin layers, produces a film with uniform dimensional characteristics such as film thickness. Making it difficult to do.

  Japanese utility model JP U3048972 proposes an extrusion die for reducing the divergence of the molten polymer flow in the manifold of the extrusion die. In the proposed extrusion mold design, two manifolds are provided to form two slit streams. Molten polymer is fed to the first inlet at the end of the first manifold and the second inlet at the end of the second manifold located opposite the first inlet. ing. The two slit flows are merged inside the mold. It has been theorized that the flow distribution within the mold can be made uniform by preventing the molten polymer flow from diverging in the manifold. Thereby, the uniformity of the plate | board thickness in the horizontal direction of a film or a sheet | seat can be improved.

  JP7-216118A in Japan discloses a battery separator formed of a porous film comprising at least two microporous layers having different polyethylene contents and comprising polyethylene and polypropylene as essential constituent elements. Yes. The polyethylene content is 0 to 20% by weight for one microporous layer, 21 to 60% by weight for the other microporous layer, and 2 to 40% by weight for the entire film. The battery separator has a relatively high shutdown start temperature and mechanical strength.

  In WO 2004/089627, composed of two or more layers, the polypropylene content in at least one surface layer is 50% or more by mass, 95% or more, or less, and the polyethylene content in the entire film is by mass, A microporous polyolefin membrane made from polyethylene and polypropylene, from 50% to 95%, is disclosed.

  WO 2005/113657 discloses a conventional microporous polyolefin film having shutdown characteristics, melting characteristics, dimensional stability, and high-temperature strength characteristics. This membrane is manufactured using a polyolefin composition comprising (a) a composition comprising low molecular weight polyethylene and high molecular weight polyethylene and (b) polypropylene. This microporous polyolefin film is manufactured by a so-called “wet process”.

  Despite the advantages of the prior art described here, there remains a need for high quality films or sheets made from extrusion molds and manifold systems, polymer solutions that can produce microporous polyolefin membranes. strong.

The invention disclosed herein relates to an extrusion mold for producing an extruded material composed of a polymer and a diluent using a mixture composed of a polymer and a diluent. Extrusion mold is
A mold outlet through which the polymer and diluent mixture is extruded;
A supply-side inlet in communication with a supply-side distributor that diverts the polymer and diluent mixture into the first part and the second part;
With cross flow manifold,
The cross flow manifold
A first cross-flow manifold portion for receiving a first portion of the mixture, the first passage having a first axis disposed in a first plane of the extrusion mold, and a second of the extrusion mold A second axis disposed in the plane of the second path, a second path communicating with the first path, a third axis disposed in the third plane of the extrusion mold, the second axis A third passage in communication with the passage, the third passage in communication with the mold outlet, and a first cross flow manifold portion,
A second cross-flow manifold portion that receives a second portion of the mixture, the first passage having a first axis disposed in a third plane of the extrusion mold, and a second passage of the extrusion mold. A second axis arranged in the plane of 4, a second path communicating with the first path, a third axis arranged in the first plane of the extrusion mold, the second axis A second cross-flow manifold portion including a third passage communicating with the first passage and a third passage communicating with the mold outlet.

In another aspect, a process is provided for producing an extrusion made of a polymer and a diluent. This process
Mixing at least one polyolefin and a diluent (e.g., a solvent) to prepare a polyolefin solution;
Extruding a polyolefin solution through an extrusion mold to form an extruded material, the extrusion mold comprising:
(1) a mold outlet where the molten stream of polyolefin solution is extruded as a film or sheet;
(2) a supply-side inlet that communicates with a supply-side distributor that divides the polyolefin solution into the first part and the second part;
(3) Equipped with a cross flow manifold.
The cross flow manifold
A first cross-flow manifold portion for receiving a first portion of the mixture, the first passage having a first axis disposed in a first plane of the extrusion mold, and a second of the extrusion mold A second axis disposed in the plane of the second path, a second path communicating with the first path, a third axis disposed in the third plane of the extrusion mold, the second axis A third passage in communication with the passage, the third passage in communication with the mold outlet, and a first cross flow manifold portion,
A second cross-flow manifold portion that receives a second portion of the mixture, the first passage having a first axis disposed in a third plane of the extrusion mold, and a second passage of the extrusion mold. A second axis arranged in the plane of 4, a second path communicating with the first path, a third axis arranged in the first plane of the extrusion mold, the second axis A second cross-flow manifold portion including a third passage communicating with the first passage and a third passage communicating with the mold outlet.

  The shape memory properties of the polymer in the polymer and diluent mixture have been found to be a factor in maintaining the thickness uniformity of the film or sheet exiting the extrusion mold. It has been observed that such a shape memory effect occurs in thermoplastic materials extruded from polymer solutions such as solutions containing polyolefins and diluents. This result was a great surprise because it was believed that if the diluent was present (although it would never disappear), the extruded material would not have a significant shape memory effect. In polymer solutions, the shape memory effect is not very large, which was thought to be due to the smaller amount of polymer (compared to the molten polymer), resulting in less polymer chain entanglement and improved rheological properties. .

  As a result, the present invention is based on the finding that the extrusion mold manifold design is affected by the shape memory phenomenon that occurs during the extrusion of the polymer solution. For this reason, in the embodiment disclosed herein, the cross flow manifold has a sufficiently long flow to minimize or substantially eliminate the shape memory effect of the thermoplastic material. It has a road.

  Furthermore, in another embodiment disclosed herein, each of the first and second crossflow manifold portions of the crossflow manifold traverses over a length at least twice the width of the extrusion mold. The flow path is provided.

  In another embodiment disclosed herein, the mold outlet is a mold outlet provided with a first mold lip portion and a second mold lip portion, and provided with a slot. The first mold lip portion has a flexible lip bar provided with driving means arranged along the width direction of the lip portion.

  Further, in another embodiment disclosed herein, the driving means of the first mold lip portion includes a plurality of lip bolts that effectively change the width of the slotted mold outlet in the region adjacent to the adjusting means. It has.

  These and other advantages, features, and characteristics of the extrusion mold and manifold system disclosed herein, as well as their effective application and / or use, depend on what is described in detail below. In particular, it will become clear by referring to the figures attached hereto.

FIG. 1 is an exploded perspective view of an extrusion mold equipped with a cross flow manifold system for producing an extruded material of a thermoplastic resin material. FIG. 2 shows a part of an exploded perspective view of an extrusion mold provided with the cross flow manifold system shown in FIG. 1, and shows a pair of end face plates arranged in the mold. FIG. 3 shows an outline of an extrusion mold for producing an extruded material of a thermoplastic resin material, and shows individual flow paths of the thermoplastic resin material. FIG. 4 is a side view of an extrusion mold for producing a surface layer of an extruded material of a thermoplastic resin material, and shows a flexible lip bar having a driving means. FIG. 5 is a perspective view of a coat hanger type extrusion mold, and shows a flow path of a thermoplastic resin material. FIG. 6 is a perspective view of a cross flow extrusion mold, and shows a flow path of a thermoplastic resin material.

  Hereinafter, a description will be given with reference to FIGS. In these drawings, the same parts are denoted by the same reference numerals.

  First, referring to FIG. 1-3, there is shown an extrusion die 10 for producing an extruded material made of a thermoplastic material made of, for example, a polymer and a diluent. The extrusion die 10 is provided with a die outlet 12 as shown in the figure, and the mixture of the polymer and the diluent is extruded as a film or a sheet (also called an extruded material) through the die outlet 12. It is like that. The mold outlet 12 may be a mold outlet provided with a slot. In one form, the extrusion mold 10 is provided with a first mold part 14, a second mold part 16, and a third mold part 18, and further the first mold part. 14, a cross flow manifold 20 is provided that is disposed across a plurality of passages formed in the second mold part 16 and the third mold part 18. As can also be seen from the figure, the machine of the crossflow manifold 20 by using an extrusion mold 10 having a first mold part 14, a second mold part 16, and a third mold part 18. Processing and cleaning can be performed easily.

  As shown in detail in FIG. 1, the cross-flow manifold 20 has a supply-side inlet 22 and a supply-side distributor 24 for supplying polymer to a plurality of passages of the cross-flow manifold 20 communicating with the mold outlet 12. Is provided. During operation, the polymer solution feed stream F is divided into a first feed stream S1 and a second feed stream S2. Then, the first supply flow S1 flows to the first cross flow manifold portion 26, and the second supply flow S2 flows to the second cross flow manifold portion 28.

  The first mold portion 14 is provided with a first side surface 30, a second side surface 32, a first end surface 34, and a second end surface 36, and these surfaces have the cross flow manifold 20 Each part is provided. The second mold portion 16 is provided with an inner side surface 38, the third mold portion 18 is provided with an inner side surface 40, and each portion of the cross flow manifold 20 is provided on these surfaces. In addition, as can be assumed from FIG. 2, the first end face plate 42 and the second end face plate 44 are also provided with respective portions of the cross flow manifold 20.

  In one form, the first cross-flow manifold portion 26 includes a first plane 50 formed between the first side 30 of the first mold portion 14 and the inner side 38 of the second mold portion 16. Formed between the first passage 26a with the first shaft disposed therein, the first end face 34 of the first mold portion 14 and the first end face plate 42 (see FIG. 2). A second passage 26b with a second axis disposed in the second plane 52, a second side 32 of the first mold part 14 and an inner side 40 of the third mold part 18. And a third passage 26c having a third shaft disposed in a third plane 54 formed therebetween. As can be assumed from FIG. 1, a part of the flow of the polymer solution flows so as to traverse downward directly from the third passage 26c. And a fourth shaft disposed in a third plane 54 formed between the second side surface 32 of the first mold part 14 and the inner side surface 40 of the third mold part 18 It balances across the fourth passage 26d.

  Similarly, the second crossflow manifold portion 28 is within a third plane 54 formed between the second side 32 of the first mold portion 14 and the inner side 40 of the third mold portion 18. A first passage 28a having a first shaft disposed therein, a fourth passage formed between the second end face 36 of the first mold part 14 and the second end face plate 44 (see FIG. 2). Between the second passage 28b with a second axis disposed in the plane 56 of the first mold portion 14, the first side surface 30 of the first mold portion 14 and the inner side surface 38 of the second mold portion 16. And a third passage 28c having a third axis disposed in the formed first plane 50. As can be assumed from FIG. 1, a part of the flow of the polymer solution flows so as to traverse downward directly from the third passage 28c. And a fourth shaft disposed in a first plane 50 formed between the first side face 30 of the first mold part 14 and the inner side face 38 of the second mold part 16. The fourth passage 28d is crossed and balanced.

  In one form, each of the first cross-flow manifold portion 26 of the cross-flow manifold 20 and the second cross-flow manifold portion 28 of the cross-flow manifold 20 includes pressure manifolds 26d and 28 that communicate with the mold outlets, respectively. .

  As shown in the figure, in one embodiment, the first plane and the third plane, and the second plane and the fourth plane are arranged substantially in parallel. As used herein, “substantially parallel” means that the surfaces facing each other (that is, the first plane and the third plane, and the second plane and the fourth plane) are extrusion molds. This means that there is no crossing inside the outer contour.

  As described below, when forming microporous membrane films and sheets from polymer solutions, the surprising properties of these materials are the inherent properties of shape memory that occur when extruding molten polymers. Indicates. Other films and sheets formed from other polymers other than the molten polymer of polyolefin similarly exhibit such characteristics. As is known in the art, shape memory plastics have two phases: a thermoplastic phase and a freezing phase. The initial shape is memorized in the freezing phase and has the shape memory effect of returning from its shape to its original shape even if the plastic is deformed to a temporary shape. As is well known, the polymer chain of the polymer has an ideal three-dimensional shape (Gaussian coil) in solution in the molten state or in the unperturbed state. For example, when the polymer is deformed by an external force such as a shear flow, the polymer shape is relaxed by expanding the polymer in the axial direction of the polymer, and the ideal Gaussian coil state is restored. This relaxation time is strongly dependent on the number of entanglements. Therefore, the longer the relaxation time is required, the higher the molecular weight of the polymer and the higher the polymer concentration in the solution.

  The shape memory effect of a mixture of a polyolefin and a diluent (eg, a polyolefin solution) has an effect on maintaining uniformity of the film thickness in the width direction of the film or sheet as it exits the extrusion mold. It becomes one element. And it was found that the design of the manifold affects this phenomenon, and this phenomenon can be corrected depending on the design method. In one form, each of the first crossflow manifold portion 26 and the second crossflow manifold portion 28 of the crossflow manifold 20 substantially changes the shape memory characteristics of the thermoplastic material. Has a flow path long enough to substantially remove the.

  In one form during operation of the extrusion mold, a mixture of polymer (eg, polyolefin) and diluent is added to the first crossflow manifold portion 26 of the crossflow manifold 20 and the second crossflow manifold portion 28 of the crossflow manifold 20. Flows across the extrusion die over a distance of one or more times the width of the extrusion die.

  In another form, each of the first crossflow manifold portion 26 and the second crossflow manifold portion 28 of the crossflow manifold 20 extends over at least twice the width of the extrusion die 10. It is equipped with a channel that crosses 10.

  In particular, as shown in FIG. 4, the mold outlet 12 of the extrusion mold 10 includes a first mold lip portion 46 and a second mold lip portion 48, and the first mold lip portion 46 includes Is provided with a flexible lip bar 60 having external drive means 62 arranged over the entire width of the first mold lip 46. The mold outlet 12 may be provided with a slot. As shown, the external drive means 62 comprises a plurality of individually arranged lip bolts 64, each lip bolt 64 effectively reducing the width of the mold outlet 12 provided with a slot in the area adjacent to the adjustment position. It can be changed to.

  The extrusion mold and manifold system disclosed herein presents difficulties in extruding a polyolefin solution from a mold in a variety of processes, including the process of forming a “wet”, microporous polyolefin film or sheet. Can solve various problems. As shown in FIG. 5, the difficult problem here is that the mold (CH) 100 equipped with a coat hanger type manifold extrudes a single-layer microporous polyolefin film or sheet 102. When used for this purpose, the thickness of the extruded material becomes non-uniform in the lateral direction due to the shape memory effect produced in the extruded material. As can be appreciated, the shape memory effect in the extruded material tends to act perpendicular to the flow S in the manifold 104 of the polyolefin solution mold. In the mold 100 provided with the coat hanger type manifold, the main direction of the flow in the manifold is directed toward the mold lip 106, so that the shape memory effect is likely to occur in the lateral direction of the extruded material. For this reason, redistribution of the material in the extruded material occurs, and the material tends to gather in the central direction along the lateral direction of the extruded material.

  Referring now to the single layer extrusion mold shown in FIG. 6, this problem can be solved by using a mold 200 with a crossflow manifold (CF). Here, the polymer and diluent mixture crosses the entire width of the mold manifold 204 before the polyolefin solution S approaches the mold lip 206. As can be understood, by doing so, most of the polyolefin solution S in the manifold portion of the mold flows parallel to the mold lip 206. As a result, the shape memory effect mainly occurs in the machine direction (longitudinal direction), and a more uniform plate thickness distribution can be obtained in the lateral direction of the extruded material.

  As described above, the extrusion mold and the manifold system disclosed herein are useful for forming a microporous polyolefin film or sheet. These films and sheets are used particularly in the severe environment of battery separators. The multilayer films and sheets described below use a single layer mold and a manifold system of the type described above to create a single layer film or sheet, and then add another layer to the single layer using conventional techniques. It can manufacture by the method of doing. Coextrusion techniques can be used, in which case the synthetic mold (eg, a mold having at least two mold outlets in close proximity) is provided with at least one of the manifolds of the present invention. It has a mold part.

  In one form, the multi-layer, microporous membrane is composed of two layers. The first layer (e.g., membrane skin layer, outer layer, upper layer) is made of the material of the first microporous layer, and the second layer (e.g., membrane bottom layer, lower layer, core layer) is And made of the material of the second microporous layer. For example, when viewed from above the axis approximately perpendicular to the lateral and longitudinal (mechanical) directions of the membrane, the membrane can see a flat upper layer and the flat bottom layer of the membrane is hidden behind the upper layer and cannot be seen. . The extrusion mold described here is a single layer microporous membrane, for example a single layer polyethylene microporous membrane and / or PCT International Publication No. WO2007 / 132942 (hereby incorporated by reference) It is also useful in the production of single layer polyolefin membranes disclosed in (which form part of this specification).

  As another form, in the case of a multi-layered microporous film having three or more layers, the outer layer (or surface layer or skin layer) is made of the material of the first microporous layer. The at least one core side layer or intermediate layer is made of the material of the second microporous layer. A related form is a multi-layer, microporous polyolefin film, in a two-layer film, the first layer is made of the material of the first microporous layer, and the second layer is the second layer. The material of the microporous layer. Further, as a related form, in the case of a multi-layered, microporous polyolefin film comprising three or more layers, the outer layer is made of the material of the first microporous layer, and at least One intermediate layer is made of the material of the second microporous layer. Such membranes are described in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389. And by quoting these publications here, these publications form a part of this specification.

The starting materials useful for the production of the aforementioned film or sheet are described below. Suitable polymers, solvents and their amounts are described, for example, in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389. As will be appreciated by those skilled in the art, the choice of starting material is not critical as long as a manifold system utilizing the principles of extrusion molds and crossflow manifolds is used. In one form, the material of the first and second microporous layers includes polyethylene. In one form, the material of the first microporous layer includes a first polyethylene (PE-1) having an Mw value of about 1 × 10 ⁶ or less or a second having an Mw value of at least about 1 × 10 ⁶ . Of polyethylene (UHMWPE-1). In one form, the material of the first microporous layer includes first polypropylene (PP-1). In one form, the material of the first microporous layer is (1) polyethylene (PE), (2) ultra high molecular weight polyethylene (UHMWPE), (3) PE-1 and PP-1, (4) PE- 1, composed of either UHMWPE-1 or PP-1.

(2) and (4) In one embodiment, UHMWPE preferably has an Mw value in the range of about 1 x 10 ⁶ to about 15 x 10 ⁶ , or in the range of about 1 x 10 ⁶ to about 5 x 10 ⁶ More desirable are those having an Mw value of about 1 x 10 ⁶ to about 3 x 10 ⁶ . In order to obtain a microporous layer having a hybrid structure as described in PCT International Publication No. WO2008 / 016174, UHMWPE-1 is about 1% by weight with respect to the total amount of PE-1 and UHMWPE-1. % Or more is more desirable, or more preferably about 15% to about 40% by weight, and may be at least either a homopolymer or a copolymer. In one embodiment of the above (3) and (4), PP-1 may be at least either a homopolymer or a copolymer, and about 25% by weight or less based on the total amount of the material of the first microporous layer. The content of is desirable. In one form, the Mw value of the polyolefin in the material of the first microporous layer may be about 1 × 10 ⁶ or less to obtain a microporous layer having a hybrid structure as defined later. It may range from about 1 × 10 ⁵ to about 3 × 10 ⁶ , or from about 2 × 10 ⁵ to about 3 × 10 ⁶ . In one form, PE-1 preferably has an Mw value in the range of about 1 x 10 ⁴ to about 5 x 10 ⁵ , or an Mw value in the range of about 2 x 10 ⁵ to about 4 x 10 ^5. What it has is further desirable. It may be one or more of high density polyethylene, medium density polyethylene, branched low density polyethylene, or linear low density polyethylene, and may be at least either a homopolymer or a copolymer.

In one form, the material of the second microporous layer is (1) a fourth polyethylene (UHMWPE-2) having an Mw value of at least about 1 × 10 ⁶ , and (2) an Mw value of 1 × 10 ⁶ or less. The third polyethylene and UHMWPE-2, as well as the fourth polyethylene, wherein the fourth polyethylene comprises at least about 8% by weight based on the total weight of the third polyethylene and the fourth polyethylene; 3) Consists of one of UHMWPE-2 and PP-2, (4) PE-2, UHMWPE-2, and PP-2. In the forms of (2), (3), and (4) described above, UHMWPE-2 is used to produce a microporous polyolefin film that is a relatively strong multilayer material. And at least about 8%, alternatively at least about 20%, alternatively at least about 25% by weight relative to the total amount of PP-2. In the above forms (3) and (4), PP-2 may be at least either a homopolymer or a copolymer, and is 25% by weight or less based on the total amount of materials of the second microporous layer, Alternatively, an amount in the range of about 2% to about 15% by weight, or in the range of about 3% to about 10% by weight can be included. In one embodiment, preferred PE-2 can be the same as PE-1, but can also be selected independently. In one embodiment, preferred UHMWPE-2 can be the same as UHMWPE-1, but can also be selected independently.

In addition to the first, second, third, fourth polyethylene and the first, second polypropylene, each of the first and second layer materials may optionally include one or more added polyolefins, And / or polyethylene wax (eg, having a Mw value in the range of about 1 × 10 ³ to about 1 × 10 ⁴ as described in US2008 / 0057388).

  In one form, a process for producing a two-layer microporous polyolefin membrane is provided, in which an extrusion mold and manifold system of the type disclosed herein is used. In another form, the microporous polyolefin membrane has at least a three-layer construction and is manufactured using an extrusion mold and manifold system of the type disclosed herein. The production of a microporous polyolefin film will be described mainly as a film having a two-layer structure and a three-layer structure.

  In one embodiment, the microporous polyolefin film having a three-layer structure is provided between the first and third microporous layers forming the outer layer of the microporous polyolefin film and the first and third layers (optional). And a second layer (core layer) disposed in contact with the substrate. In another form, the first layer and the third layer are made from a first polyolefin solution and the second layer (core layer) is made from a second polyolefin solution.

In one embodiment, a method for producing a microporous polyolefin film having a multilayer structure is provided. The manufacturing method is
(1) To prepare a first mixture of polyolefin and diluent (first polyolefin solution), a first polyolefin composition and at least one diluent (e.g., a film-forming solvent) (e.g., melted) Mixing (by blending);
(2) To prepare a second mixture of polyolefin and diluent (second polyolefin solution), a second polyolefin composition and at least a second diluent (for example, a second film-forming solvent) Mixing, and
(3) extruding first and second polyolefin solutions from at least one mold of the type disclosed herein to form a multi-layer extruded material;
(4) optionally cooling the multi-layered extruded material to form a cooled extruded material;
(5) removing at least a portion of the film-forming solvent from the extruded or cooled extruded material to form a multilayered film;
(6) Preferably, the method includes a step of removing at least a volatile substance from the multi-layered film.
The step (7) of stretching the optional extruded material and the step (8) of treating the optional extruded material with a heated solvent are performed between steps (4) and (5) if necessary. After step (6), optionally stretching (9) a multi-layered microporous film, optionally heat-treating the multi-layered microporous film (10), and optionally ionizing radiation The step (11) of crosslinking by, the step (12) of hydrophilic treatment as an option, etc. can be carried out.

  The first polyolefin composition is composed of a polyolefin resin as described above and is mixed with a suitable film forming solvent, for example, by dry blending or melt blending, to create a first polyolefin solution. As an option, for example, as disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389, the first polyolefin solution may include one or more antioxidants, silicate fine powder ( An additive such as a pore forming material may also be included.

  The first and second diluents can be solvents that are in a liquid state at room temperature. Suitable diluents are disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389.

In one form, the resin or the like used to produce the first polyolefin composition is melt blended in an extruder or blender using two screw members. For example, conventionally used extruders (or blenders and blender-extruders), such as an extruder using two screw members, use a resin or the like to form the first polyolefin composition. Can be used when mixing. Diluents can be added to the polyolefin composition (or the resin used to create the polyolefin composition) at a convenient point in the process. For example, in one form, the first polyolefin composition and the first diluent (film forming solvent) are melt blended and the solvent is
(1) Before starting melt blending,
(2) During melt blending of the first polyolefin composition, or
(3) Can be added to the polyolefin composition (or its components) at any stage after melt blending. And this is, for example, melt blended or partially melt blended in a region located downstream of the extruder used to melt blend the polyolefin composition or in a second extruder. The first film-forming solvent is supplied to the polyolefin composition.

  Suitable methods for blending the polymer and diluent are disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389.

  The amount of the first polyolefin composition in the first polyolefin solution is not critical. In one form, the amount of the first polyolefin composition in the first polyolefin solution can range from about 1 wt% to about 75 wt%, for example, about 1 wt%, based on the weight of the polyolefin solution. It may be in the range of 20 wt% to about 70 wt%. The remaining part of the polyolefin solution is solvent. For example, the polyolefin solution may include from about 30% to about 80% by weight solvent (or diluent) based on the weight of the polyolefin solution.

  The second polyolefin solution can be prepared by the same method used in preparing the first polyolefin solution. For example, the second polyolefin solution can be prepared by melt blending the second polyolefin composition and the second film-forming solvent.

  The amount of the second polyolefin composition in the second polyolefin solution is not critical. In one form, the amount of the second polyolefin composition in the second polyolefin solution can range from about 1 wt% to about 75 wt%, based on the weight of the second polyolefin solution, For example, it may be in the range of about 20 wt% to about 70 wt%. The remaining part of the polyolefin solution is solvent. For example, the polyolefin solution may include from about 30% to about 80% by weight solvent (or diluent) based on the weight of the polyolefin solution.

  Conveniently, an extrusion die of the type disclosed herein is used to form an extrusion that can be coextruded or laminated. As one form, the extrusion metal mold | die which can be arrange | positioned in parallel or arrange | positioned together is used in order to form a some extrusion material. The first and second sheet molds are connected to the first and second extruders, respectively. Here, the first extruder is provided with the first polyolefin solution, and the second extruder is provided with the second polyolefin solution. While not critical, when laminating, it is generally easy to do laminating when the extruded first and second polyolefin solutions are still near the extrusion temperature.

  In another form, first, second, and third molds are connected to the first, second, and third extruders. Here, the first and third molds are provided with the first polyolefin solution, and the second mold is provided with the second polyolefin solution. In this form, the laminated extruded material is formed to constitute two outer layers made of the extruded first polyolefin solution and one intermediate layer made of the extruded second polyolefin solution.

  In yet another form, first, second, and third molds are connected to the first, second, and third extruders. Here, the second mold includes the first polyolefin solution, and the first and third molds include the second polyolefin solution. In this form, the laminated extruded material is formed to constitute two outer layers composed of the extruded second polyolefin solution and one intermediate layer composed of the extruded first polyolefin solution.

  In general, the gap size of the mold is not particularly critical. For example, an extrusion mold of the type disclosed herein can have a mold gap dimension between about 0.1 mm and about 5 mm. Mold temperature and extrusion rate are also non-critical parameters. For example, during extrusion, the mold temperature can be heated to be in the range of about 140 ° C to about 250 ° C. The extrusion rate can be, for example, in the range of about 0.2 m / min to about 15 m / min. The thickness of the layer of the extruded material having a laminated structure can be set independently. For example, the sheet finally obtained can have a relatively thick skin layer or surface layer compared to the thickness of the intermediate layer of the extruded material having a laminated structure.

  Optionally, the multi-layer extrusion can be cooled. The cooling rate and cooling temperature are not particularly critical. Suitable cooling methods are disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389.

  In one form, at least the first and second film-forming solvents are removed from the multilayered extruded material to form a multilayered microporous film. Suitable solvent (diluent) removal methods are disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389. For example, a cleaning solvent is used.

  In one form, at least volatile material (eg, cleaning solvent) left on the film is removed. Suitable methods for removing volatile materials are disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389.

  Prior to the step for removing the film-forming solvent, the extruded material can be stretched to obtain an extruded material with directionality. Methods for drawing extruded or cooled extruded materials are disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389.

  Although not required, the extruded material can be treated with a high temperature solvent as disclosed in PCT International Publication No. WO2000 / 20493.

  As one form, the microporous film can be stretched in at least one axial direction after removing at least the diluent. The selected stretching method is not critical and conventional stretching methods such as the tenter method can be used. As described herein, when the extruded material is stretched, stretching a microporous polyolefin film in a dry state is called dry stretching, re-stretching, or dry orientation. Appropriate stretching methods are disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389.

  The amount of stretching when stretching is not a critical issue. For example, the amount of stretch of the microporous membrane can range from about 1.1 to about 2.5, or from about 1.1 to about 2.0, in at least one in-plane direction. Biaxial stretching is also possible, and in this case, the amount of stretching need not be symmetrical (the same for each axis).

  In one form, the microporous film can be heat treated and / or annealed. Microporous membranes can be cross-linked if necessary (eg, by irradiation with ionizing radiation such as a-rays [3-rays, 7-rays, electron beams, etc.]). Further, a hydrophilic treatment can be applied to the microporous membrane. (That is, this hydrophilic treatment makes the microporous olefin membrane more hydrophilic. [Eg, monomer affinity treatment, surfactant treatment, corona discharge treatment, etc.]) Heat treatment of membrane, annealing, Suitable methods for treatments such as crosslinking are disclosed in PCT International Publication Nos. WO2008 / 016174, US2008 / 0057388, and US2008 / 0057389.

  In addition, the microporous film manufacturing method disclosed in PCT International Publication No. WO2008 / 016174 (multilayer film) and No. WO2007 / 132942 (single layer film) can also be used.

  All patents, test procedures, and other documents cited herein, including the document on which priority is claimed, are hereby incorporated by reference in their entirety to the extent they are not contradictory. And this should be allowed in all jurisdictions.

  Although the embodiments disclosed herein have been described as specific, it is possible for those skilled in the art to make various improvements without departing from the technical idea of the present invention. It is self-evident and it can be easily implemented. Therefore, the scope of claims (claims) attached to the present specification is not limited to the examples and descriptions described in the present specification. It should be construed as including all the patentable novel technical features described therein, and all such technical features shall be deemed equivalent by those skilled in the art to which this invention belongs. Should be handled.

  In this specification, when an upper limit numerical value and a lower limit numerical value are described, it is intended to include a range from the lower limit to the upper limit.

Claims (22)

An extrusion mold for producing a thermoplastic resin extrusion material from a mixture of a polymer and a diluent,
(1) a mold outlet through which a thermoplastic resin extruded material is extruded as a film or sheet;
(2) a supply-side inlet communicating with a supply-side distributor that diverts the mixture into the first part and the second part;
(3) Cross flow manifold
(a) a first cross-flow manifold portion that receives a first portion of the mixture, the first passage having a first shaft disposed in a first plane of the extrusion mold, and the extrusion die A second axis disposed in the second plane of the mold, a second path communicating with the first path, and a third axis disposed in the third plane of the extrusion mold A first cross-flow manifold portion comprising a third passage in communication with the second passage and a third passage in communication with the mold outlet;
(b) a second cross-flow manifold portion that receives a second portion of the mixture, the first passage having a first axis disposed in a third plane of the extrusion mold, and the extrusion die A second axis disposed in the fourth plane of the mold, a second path communicating with the first path, and a third axis disposed in the first plane of the extrusion mold A second passage that communicates with the second passage, the third passage comprising a third passage that communicates with the mold outlet,
An extrusion mold characterized by comprising:   2. The extrusion die according to claim 1, wherein the first plane and the third plane, and the second plane and the fourth plane are arranged substantially parallel to each other. Extrusion mold characterized by.   3. The extrusion die according to claim 1 or 2, wherein the first cross flow manifold portion includes a fourth shaft disposed in a third plane of the extrusion die, and communicates with the third passage. And an extrusion die further comprising a fourth passage communicating with the die outlet. The extrusion mold according to claim 3,
The second cross-flow manifold portion includes a fourth shaft disposed in the first plane of the extrusion mold, and further includes a fourth passage communicating with the third passage and communicating with the mold outlet. An extrusion mold characterized by comprising. The extrusion mold according to any one of claims 1 to 4,
The mold outlet is a mold outlet provided with a slot having a first mold lip portion and a second mold lip portion, and the first mold lip portion is a width of the lip portion. An extrusion die comprising a flexible lip bar having driving means arranged along a direction.   6. The extrusion mold according to claim 5, wherein the driving means includes a plurality of individual lip bolts, and the individual lip bolts have a width of a mold outlet provided with a slot in a region adjacent to the adjustment member. Extrusion mold characterized in that it can be changed.   The extrusion mold according to any one of claims 1 to 6, wherein the melt flow of the mixture is obtained by passing a first crossflow manifold portion of the crossflow manifold and a second crossflow manifold portion of the crossflow manifold. An extrusion die characterized in that it traverses a distance substantially equal to a length equal to or more than one length in the width direction of the extrusion die.   The extrusion mold according to any one of claims 1 to 7, wherein each of the first crossflow manifold portion of the crossflow manifold and the second crossflow manifold portion of the crossflow manifold has a width of the extrusion die. An extrusion die comprising a flow channel adapted to substantially traverse a length at least twice the directional length.   9. The extrusion mold according to claim 1, wherein each of the first crossflow manifold portion of the crossflow manifold and the second crossflow manifold portion of the crossflow manifold is made of a thermoplastic resin material. An extrusion die comprising a flow path having a length sufficient to substantially reduce shape memory characteristics.   10. The extrusion mold according to claim 1, wherein each of the first crossflow manifold portion of the crossflow manifold and the second crossflow manifold portion of the crossflow manifold is provided at the mold outlet. An extrusion die having a pressure manifold in communication. A method for producing an extruded material made of thermoplastic resin,
(1) mixing at least one polymer and at least one diluent;
(2) extruding the mixed polymer and diluent through an extrusion mold to form an extruded material, and
The extrusion mold is
(a) a mold exit where the mixed polymer and diluent are to be extruded as a multi-layered film or sheet;
(b) a supply-side inlet communicating with a supply-side distributor that diverts the mixed polymer and diluent into the first part and the second part;
(c) Equipped with a cross flow manifold,
The cross flow manifold
A first cross-flow manifold portion that receives a first portion of the mixed polymer and diluent, the first passage having a first axis disposed in a first plane of the extrusion mold; A second axis disposed in the second plane of the extrusion mold, the second path communicating with the first path, and a third axis disposed in the third plane of the extrusion mold A first cross-flow manifold portion comprising a third passage communicating with the second passage and a third passage communicating with the mold outlet;
A second cross-flow manifold portion that receives a second portion of the mixed polymer and diluent, and a first passage with a first axis disposed in a third plane of the extrusion mold; A second axis disposed in the fourth plane of the extrusion mold, a second path communicating with the first path, and a third axis disposed in the first plane of the extrusion mold A second cross flow manifold portion comprising a third passage in communication with the second passage and a third passage in communication with the mold outlet;
A method comprising:   12. The method according to claim 11, wherein the first plane and the third plane, and the second plane and the fourth plane are arranged so as to be substantially parallel to each other. And how to. The method according to claim 11 or 12, comprising:
The first cross-flow manifold portion includes a fourth shaft disposed in a third plane of the extrusion mold, and further includes a fourth passage communicating with the third passage and communicating with the mold outlet. A method characterized by comprising. 14. A method according to claim 13, comprising
The second cross-flow manifold portion includes a fourth shaft disposed in the first plane of the extrusion mold, and further includes a fourth passage communicating with the third passage and communicating with the mold outlet. A method characterized by comprising. 15. A method according to any of claims 11 to 14, comprising
The mold outlet is a mold outlet provided with a slot having a first mold lip portion and a second mold lip portion, and the first mold lip portion is a width of the lip portion. A method comprising a flexible lip bar with drive means arranged along a direction.   16. The method according to claim 15, wherein the means for driving the mold outlet provided with the slot of the extrusion mold includes a plurality of individual lip bolts, the individual lip bolts being located in a region adjacent to the adjusting member. A method characterized in that the width of the mold outlet provided with the slot can be changed.   17. The method according to any one of claims 11 to 16, wherein the melt flow of the thermoplastic resin material passes between a first cross flow manifold portion of the cross flow manifold and a second cross flow manifold portion of the cross flow manifold. A method of traversing over a distance substantially equal to a length of 1 or more times the length of the extrusion die in the width direction.   18. The method according to claim 11, wherein each of the first cross flow manifold portion of the cross flow manifold and the second cross flow manifold portion of the cross flow manifold has a length in a width direction of the extrusion die. Comprising a channel adapted to substantially traverse at least twice as long.   The method according to any one of claims 11 to 18, wherein each of the first crossflow manifold portion of the crossflow manifold and the second crossflow manifold portion of the crossflow manifold has a shape memory characteristic of the extruded material. A method comprising providing a flow path long enough to substantially reduce.   20. The method according to any one of claims 11 to 19, wherein each of the first crossflow manifold portion of the crossflow manifold and the second crossflow manifold portion of the crossflow manifold communicates with the mold outlet. A method comprising a pressure manifold.   A co-extrusion die for producing an extruded material having a multilayer structure, comprising the extrusion die according to claim 1 and at least a second extrusion die. The coextrusion die according to claim 21, wherein the second extrusion die is
(1) a mold outlet for extruding a mixture of polymer and diluent to mold a thermoplastic resin material;
(2) a supply-side inlet communicating with a supply-side distributor that diverts the mixture into the first part and the second part;
(3) Cross flow manifold
(a) a first cross-flow manifold portion that receives a first portion of the mixture, the first passage having a first shaft disposed in a first plane of the extrusion mold, and the extrusion die A second axis disposed in the second plane of the mold, a second path communicating with the first path, and a third axis disposed in the third plane of the extrusion mold A first cross-flow manifold portion comprising a third passage in communication with the second passage and a third passage in communication with the mold outlet;
(b) a second cross-flow manifold portion that receives a second portion of the mixture, the first passage having a first axis disposed in a third plane of the extrusion mold, and the extrusion die A second axis disposed in the fourth plane of the mold, a second path communicating with the first path, and a third axis disposed in the first plane of the extrusion mold A second passage that communicates with the second passage, the third passage comprising a third passage that communicates with the mold outlet,
A coextrusion mold characterized by comprising:

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