JP3597317B2 - Spiral die and method of manufacturing laminate using the same - Google Patents

Description

【００４６】
（押出条件）
【００４７】
【表２】

【００４８】
（用いたスパイラルダイの仕様）

［駆動部］
・駆動用モーター ３．０ＫＷ ＥＳサーボモーター
・減速機 ウオーム減速機
・駆動方式 チェーン方式
［測定方法］
１．破断応力、破断伸度、降伏点応力
ＪＩＳ Ｋ−７１２７に準拠し、オリエンテック（株）製テンシロン型万能試験機ＲＴＭ−１００を用いて、以下の条件で測定した。
【００４９】
・試料長（つかみ具間距離） ５０ｍｍ
・試料幅 １０ｍｍ
・クロスヘッド速度 ５００ｍｍ／ｍｉｎ
・試験温度 ２３℃
・試験湿度 ５０％相対湿度
２．ヤング率
ＪＩＳ Ｋ ７１２７に準拠し、オリエンテック（株）製テンシロン万能試験機ＲＴＭ−１００を用いて以下の条件で測定した。
【００５０】
・試料長（つかみ具間距離） １００ｍｍ
・試料幅 ２０ｍｍ
・クロスヘッド速度 １０ｍｍ／ｍｉｎ
・試験温度 ２３℃
・試験湿度 ５０％相対湿度
【００５１】
【発明の効果】
上記表１を見れば明らかなように、固定スパイラルダイを用いる比較例１においては、厚み方向積層数が１４〜１５層であったのに対し、本発明の回転スパイラルダイを用いて−０．１ｒｐｍ〜＋４ｒｐｍまで回転数を変化させた実施例１〜５においては、厚み方向積層数を１０〜１１層から５５〜５７層まで幅広く増減可能であり、それに伴い得られる積層フィルムの破断応力、破断伸度、ヤング率、降伏点応力の調整も可能であることが判かる。
【図面の簡単な説明】
【図１】従来の多層用スパイラルダイの断面図および製品フィルム断面図。
【図２】図１のスパイラルダイを用いて得られる積層樹脂フィルムの斜視図および二方向断面図。
【図３】先に開発された固定スパイラルダイの一例の断面図および製品フィルムの断面図。
【図４】図３のスパイラルダイの要部の模式斜視図。
【図５】図３のスパイラルダイにより製造された積層樹脂フィルムの一例の斜視図および二方向断面図。
【図６】本発明の回転スパイラルダイを含む装置系の一例の模式断面図および製品フィルムの断面図。
【図７】図６のＸ−Ｘ部における内側ダイリングの拡大斜視図。
【図８】図７よりも内側の樹脂Ａの分配部流路構造図。
【図９】図８よりも内側の樹脂Ｂの分配部流路構造図。
【図１０】図６の回転スパイラルダイの軸方向断面図。
【図１１】図６〜図１０の回転スパイラルダイにより得られる積層フィルムの一例の斜視図および二方向断面図。
【図１２】本発明の回転スパイラルダイを含む装置系の別の一例の模式断面図。
【符号の説明】
１：積層樹脂フィルム（１ａ、１ｂ：その主たる二表面）
Ａ、Ｂ：構成樹脂種
１０ａ、１０ｂ、１０ｃ、２０ａ、２０ｂ：押出機
１１、２１：スパイラルダイ
１２１：回転スパイラルダイ
１２ａ、１２ｂ、２２ａ、２２ｂ：ダイリング
１２２ａ：回転内側ダイリング
１２２ｂ：固定外側ダイリング
２２ａｂ：内外ダイリング間間隙流路
１３ａ、２３ａ１、２３ａ２、２３ａ３、２３ｂ１、２３ｂ２、２３ｂ３：トーナメント分岐部
１４ａ、２４ａ、２４ｂ：スパイラル流路溝
１５ａ、１５ｂ、１５ｃ、２５：筒状流路
１６：合流点
１７、２７：ダイリップ
２８ａ、２８ｂ：分配部最終流路
３１：スプロケット
３２：チェーン
３３：モータ
３４：回転流路カバー
３５：ベアリング
３６：樹脂漏らし口
３７：シャフト部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a spiral die for extruding a laminated resin tubular body and a method for producing a laminated body using the same.
[0002]
[Prior art]
In order to obtain characteristics that cannot be obtained with a single resin film, formation of a laminated resin film is widely performed. As a typical example of such a laminated resin film, a gas barrier resin layer which is difficult to stretch by itself and an adhesive which imparts stretchability to the gas barrier resin layer and adheres to the gas barrier resin layer And a laminated film of a resin layer having good properties. A preferred method for producing such a laminated resin film is a multilayer inflation method. The performance of the laminated resin film is particularly affected by the number of laminations, and as long as they have the same composition ratio, the larger the number of laminations, the smaller the Young's modulus is. It is desired to increase the number of laminated layers for the purpose of controlling the physical properties of the obtained laminated resin film. However, the number of laminated layers of the laminated resin film obtained by the conventional method is generally up to about 10 layers. However, it has not been realized due to an increase in the size of the die due to an increase in the number of resin flow paths in the above.
[0003]
Generally, each resin to be laminated is melt-kneaded by an individual extruder and then supplied to a molding die used in a multilayer inflation method through respective pipe-shaped flow paths.
[0004]
As the molding die, there are molding die of not only basic type such as (1) spider type, (2) spiral type, (3) crosshead type, (4) manifold type, but also a combination type of these. Regardless of the method, in the die, each resin is molded into a thin cylindrical shape by itself according to the respective flow path method, and after the thickness is adjusted, the resin is similarly molded into a thin cylindrical shape. And merges with another flowing cylindrical resin flow, and is laminated to form a multilayer tube shape, which is extruded from a die lip. In such a die, a cylindrical resin flow path corresponding to the required number of laminations is required, and if the number of laminations is increased to improve the function of the laminated inflation film, the die becomes correspondingly complicated and large in size. It is clear that manufacturing and assembling the die become complicated, and the dies require enormous costs, and there are many problems in assembling and disassembling the die.
[0005]
Some proposals have been made to obtain a laminate with a simpler die structure. For example, Japanese Patent Publication No. 55-23733 proposes a method in which another molten resin is supplied from the inside to the middle of the flow path of the spiral die to obtain a laminate. Japanese Patent Application Laid-Open No. 1-261426 proposes a method in which an auxiliary thermoplastic resin is passed through a so-called static mixer into a base thermoplastic resin to be dispersed in a film form. However, these methods are still not satisfactory from the viewpoint of obtaining a multilayer laminate using a simpler resin flow path or maintaining a laminating effect.
[0006]
On the other hand, in the production of a multilayer blown film, a spiral die is commonly used. However, since the molten resin is molded into a thin-walled cylindrical shape with less unevenness in thickness, the number of spiral die (the number of spiral flow grooves) should be as small as possible. It is desirable to increase. In order to uniformly distribute the molten resin in the grooves formed in such a multi-strand, a method of uniformly distributing the molten resin supplied from the side direction by the (reverse) tournament-shaped branch grooves provided on the peripheral surface of the die ring. (Japanese Patent Publication No. 58-29209). However, the (reverse) tournament branching method is a method for achieving uniform distribution of a single (single) molten resin.
[0007]
As a result of studying in consideration of the above-described circumstances, the present inventors have studied a spiral die having a simple structure capable of efficiently manufacturing a multilayer laminate of a plurality of resins. Using the (reverse) tournament branching method, which has been used for the uniform distribution of resin, for distributing a plurality of resins in a fixed order, and introducing the distributed resins to a multi-layered spiral flow channel. As a result, it has been found that a laminate in which the plural resins are regularly laminated can be effectively obtained, and a spiral die for molding a laminate having a simple structure has already been developed. That is, the spiral die for forming a laminate has a plurality (m; where m is a natural number) of spirals whose depth gradually decreases between the inner die ring and the outer die ring arranged in a fitting relationship with each other. A flow channel is formed, and a plurality (n; n is a natural number and n <m) of molten resin flows composed of different resins are formed in a predetermined order in the plurality (m) of spiral flow channels. Distributing grooves for distributing and introducing are provided, and before the individual resin flows advance in the spiral flow grooves to form a uniform cylindrical flow in the die axial direction, the plurality of molten resin flows are spread in the spiral flow grooves. (See Japanese Patent Application Laid-Open No. H8-90362).
[0008]
[Problems to be solved by the invention]
The spiral die for forming a laminate (fixed spiral die) developed as described above is extremely effective in that a multilayer laminate can be formed with a simple structure, and the characteristics of a product film or sheet are obtained. Can be increased to some extent in a narrow range such as the melt viscosity of the inflow resin and the melt viscosity ratio. However, if you want to change the number of layers more, you need to change the design of the spiral flow channel and prepare a separate spiral die. Was impossible to control.
[0009]
Accordingly, a main object of the present invention is to provide a spiral die capable of forming a multilayer laminate having a different number of laminates from a combination of a plurality of resins, and a method of manufacturing a laminate using the spiral die.
[0010]
[Means for Solving the Problems]
As a result of further research for the above-mentioned purpose, the present inventors have changed the configuration of the previously developed spiral die (fixed spiral die) to rotate at least one of the inner die ring and the outer die ring. By adjusting the rotation direction and speed or the rotating portion, the design of the spiral flow channel using the same combination of plural resins as used in the case of using the fixed spiral die is the same as the fixed spiral die. It has been found that even when extrusion molding is performed from a die, a laminate having a different number of laminates can be formed.
[0011]
The spiral die (rotating spiral die) for forming a laminate according to the present invention is based on such findings, and more specifically, the inner die ring and the outer die ring are fitted with each other, and at least one of them. A plurality (m; m is a natural number) of spiral flow grooves of which one is rotatably arranged and the depth of which is gradually reduced on the inner die side between the inner die and the outer die. And a plurality (n; n is a natural number and n <m) of molten resin flows composed of different resins are distributed and introduced into the plurality (m) of spiral flow grooves in a predetermined order. Before the individual resin flows supplied from the inner die ring through the distribution grooves progress through the spiral flow grooves to form a uniform cylindrical flow in the die axis direction, the plurality of melts are formed. Tree Flow is characterized in that is configured to stack in a certain order as a leakage flow from the spiral flow path groove.
[0012]
According to another aspect of the present invention, the inner die ring and the outer die ring are fitted in each other, and at least one of the inner die ring and the outer die ring is rotatably arranged. A plurality of (m; m is a natural number) spiral flow grooves, each having a gradually decreasing depth, formed on the inner die side between the plurality of (m) spiral flows. While rotating at least one of the die rings, a flow of a molten resin made of a plurality of different resins (n; n is a natural number and n <m) from the inner die ring to the inner groove while rotating at least one of the die rings. The plurality of molten resin flows are distributed and introduced in a certain order through the distribution grooves provided in the ring, and before the individual resin flows advance in the spiral flow channel to form a uniform cylindrical flow in the die axis direction. Said By laminating in a certain order as the leakage flow from the radial flow channel, a laminated tubular body is obtained, in which a plurality of the resins are obliquely laminated in a circumferential cross section thereof. You.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be specifically described mainly based on Comparative Examples and Examples in which a laminated cylindrical body of a gas barrier resin A and a resin B having excellent stretchability and adhesiveness is obtained.
[0014]
First, FIG. 1A is a schematic cross-sectional view of a conventional general spiral die for multilayer molding. First, the resin B extruded from the extruder 10a (not shown) and introduced into the spiral die 11 is a so-called (reverse) tournament type branch disposed near the outer periphery of the first die ring (innermost ring) 12a. While being uniformly branched by the passage 13a (only one is shown), it is introduced into a plurality of spiral flow grooves 14a provided on the outer peripheral surface of the first die ring 12a. Each of the spiral flow channel grooves 14a has a groove depth that gradually decreases as the spiral flow groove 14a moves in the traveling direction (upward), and the flow of the molten resin B passing therethrough causes leakage from the groove overflowing the gap with the second die ring 12b. The flow proceeds spirally upward while forming a flow, and finally progresses upward as a uniform axial cylindrical flow through the groove-free cylindrical flow path 15 a to reach a junction 16. On the other hand, the flow of the molten resin A extruded from the extruder 10b is similarly branched, and passes through a spiral flow accompanied by a leak flow, becomes a uniform axial cylindrical flow passing through the cylindrical flow path 15b, and reaches a junction 16. Similarly, the flow of the molten resin B extruded by the extruder 10c also forms a uniform axial cylindrical flow passing through the cylindrical flow path 15c through a spiral flow accompanied by a branch flow and a leak flow, and reaches the junction 16. At the junction 16, these three cylindrical flows are laminated and extruded from the die lip 17 as a laminated cylindrical body. As shown in FIG. 1 (b), the laminated tubular body extruded from the die lip 17 has a gas-barrier resin layer A as an intermediate layer and an adhesive and stretchable resin layer B on both sides thereof. This constitutes a cylindrical laminate.
[0015]
The thus-formed tubular laminate is subjected to an inflation process for enlarging and thinning as necessary, and then, generally, a sheet or film (hereinafter referred to as a sheet or film) obtained by cutting in a direction parallel to an axis. 2 ((a) is a schematic perspective view, (b) is a vertical (MD) direction cross-section parallel to the axis, and (b) is a schematic perspective view without specifically limiting the thickness). c) is a film having a uniform three-layer structure in which a resin A layer is laminated on two resin B layers as shown in the TD direction (a cross-sectional view in a direction orthogonal to the MD).
[0016]
On the other hand, FIG. 3A is a schematic cross-sectional view of a fixed spiral die 21 previously developed by the present inventors, and is extruded from the extruders 20a and 20b and introduced into the spiral die 21 respectively. Each of the flows of the resins A and B is branched by a (reverse) tournament-type branch path (not shown, described later) similar to 13a in FIG. It is introduced into the flow channels 24a, 24b. Thereafter, as a spiral flow accompanied by a leakage flow along these spiral flow grooves, the molten resin A and the molten resin A are formed while traveling upward through a single cylindrical flow path between the inner die ring 22a and the outer die ring 22b. B are alternately stacked obliquely and extruded from the die lip 27 through the cylindrical flow path 25 having no spiral flow path groove. As shown in FIG. 3 (b), the extruded laminated cylindrical body has a circumferential cross section (cross section perpendicular to the axis (TD) direction) in which resins A and B are alternately laminated obliquely. Become.
[0017]
FIG. 4 is a schematic perspective view of a frame III portion surrounded by a dashed line in FIG. 3A for describing the distribution-stacking of the molten resin flows A and B in more detail. That is, the molten resin flows A and B introduced into the spiral die 21 through the extruders 20a and 20b first reach the tournament branch points 23a1 and 23b1, and then further branch through the branch points 23a2, 23b2. Are repeatedly introduced after passing the final branch points 23a3, 23b3 into the distribution section final flow paths 28a, 28b, 28a, 28b,..., And from there into the spiral flow path grooves 24a, 24b, 24a, 24b,. The resin flows A and B alternately flow. Here, the starting points of the spiral flow grooves 24a, 24b, 24a, 24b... (The end points of the distribution part final flow paths 28a, 28b, 28a, 28b...) Are substantially the same as the inner die ring 22a. Located on the circumference. The resin flows A and B entering the spiral flow grooves 24a and 24b initially proceed exclusively as spiral flows along the spiral flow grooves 24a and 24b, but gradually the inner die ring 22a, particularly the spiral ridges. In the flow path 22ab, which is the gap between the outer die ring 22b and the outer die ring 22aa, a leakage flow that passes over the spiral ridge 22aa occurs along the flow path (that is, upward). That is, the flow films of the resin A and the resin B flow out of the spiral flow grooves as if they were formed in the circumferential direction. Then, the flow films of the resin A and the resin B thus formed are respectively formed on the flow film of the resin B and the resin A flowing out of the spiral grooves 24b and 24a on the downstream side, that is, the flow film A and the flow film B are respectively formed. They are stacked so as to cover each other alternately. The stacking angle matches the development angle ω of the resin leaking from each spiral flow channel (FIG. 3B). That is, the starting point of the spiral flow channel forms the outer surface side, moves toward the inner surface side as the layers are stacked, and reaches the inner surface when moved by the development angle ω. As described above, the resin A and the resin B are stacked in an inclined state by the respective development angles ω (FIG. 3B). The development angle ω can be controlled by the initial depth of the spiral channel grooves 24a and 24b formed for each of the resins A and B, and the rate of gradually decreasing the depth, but is generally in the range of 60 ° to 720 °, Preferably it is in the range of 80 ° to 360 °, more preferably in the range of 130 ° to 230 °.
[0018]
Returning to FIG. 3, the laminated tubular body extruded from the die lip may be cut in a direction generally parallel to the axis through an inflation process for enlarging and reducing the thickness, if necessary, to thereby adjust the shape of the film. Is done.
[0019]
The laminated resin film thus obtained has a structure as shown in FIGS. 5 (a) to 5 (c), corresponding to FIGS. 2 (a) to 2 (c). In particular, as is clear from FIGS. 5B and 5C, the laminated resin film 1 has a cross section in the MD direction in which the resin layers A and B are alternately laminated in parallel (FIG. 5B). ), In the cross section in the TD direction, the respective resin layers A and B are alternately stacked diagonally so as to reach the two main surfaces 1a and 1b (FIG. 5C). However, the angle θ between the individual resin layers A and B and the two main surfaces 1a and 1b of the laminated resin film 1 is not so large as shown in FIG. 5C, and generally exceeds 0 ° and is 4 °. It is in the following range, especially in the range of 0.001 ° to 0.4 °. The angle θ can be represented by the following relational expression.
[0020]
tan θ = [film thickness (mm)] / [length of the entire circumference of the film (mm) × development angle (ω) / 360 °]
As can be seen from the above description, the fixed spiral die described with reference to FIGS. 3 and 4 developed earlier by the present inventors has a simple structure, for example, from a combination of two resins A and B. , Having a very characteristic effect that a multilayer laminate having the number of laminations of 10 to 20 can be easily formed. However, as described above, the number of layers is determined by the combination of resins for a specific spiral die, and it is not easy to increase or decrease the number even if it is possible to some extent. Cost. On the other hand, the rotating spiral die of the present invention has a structure in which at least one of the inner die ring and the outer die ring is rotatable, and the operating conditions are changed such that the rotation speed, the rotation direction, and the rotation part are changed. Thus, it is possible to relatively easily change the number of laminations relatively easily. Hereinafter, the embodiment will be further described with reference to the drawings.
[0021]
FIGS. 6 to 10 illustrate a preferred embodiment of the rotary spiral die of the present invention, in which an inner die ring is rotatable and an outer die ring is fixed (non-rotating). FIG. 6 is an overall explanatory view including a drive system; FIG. 7 is an enlarged view of an inner die ring (spiral mandrel portion) 122a of a portion surrounded by a dotted line X in FIG. 6, and FIGS. FIG. 5 is a view showing a state in which a cover of a distribution groove provided in a distribution unit is further removed one by one. FIG. 10 is a cross-sectional view including the axis of the rotary spiral die 121 formed by combining the inner die ring 122a and the outer die ring 122b. In FIG. 6 and subsequent figures, parts similar to those in FIGS. 3 and 4 are denoted by similar reference numerals. 6 to 9, the spiral die 121 is shown wider than FIG. 10 for convenience of explanation, but the actual aspect ratio is closer in FIG.
[0022]
Compared to the fixed spiral die 21 described with reference to FIGS. 3 and 4, the rotary spiral die 121 has a chain 32 wound around a sprocket 31 (FIG. 10) provided below the inner die ring 122 a, The difference is that the die ring 22a is configured to be rotatable.
[0023]
The flows of the resins A and B introduced into the rotary spiral die 121 by the extruders 20a and 20b basically change the flow of the resins A and B introduced into the fixed spiral die 21 described with reference to FIGS. Same as flow. 8 mainly shows the flow path structure of the resin A in the distribution section, that is, the branch points 23a1, 23a2,..., And the flow path 28a. FIG. 9 shows one layer corresponding to the flow path of the resin A from FIG. Except further, the flow path structure of the resin B provided inside, that is, the branch portions 23b1, 23b2,..., And the flow path 28b are shown. However, the resin A flow path structure shown in FIG. 8 further rotates integrally with the inner die ring 122a and is covered with a cover 34 that provides a rotational sliding surface with the outer die ring 122b. 28a is exposed on the sliding surface with the outer die ring 122b so that the distribution of the resin A (and the regular lamination with the resin B layer) is not hindered. The rotation of the inner die ring 122 a with respect to the shaft portion 37 is supported by the bearing 35.
[0024]
According to the present invention, when the inner die ring 122a is rotated with respect to the fixed outer die ring 122b, by changing the rotation direction and the rotation speed, the development angle of the resin leaking from each spiral flow channel 24a, 24b. ω (FIG. 6B) changes. That is, the inner die ring 122a is rotated in the forward direction (the direction in which the screws are loosened by comparing the spiral flow grooves 24a and 24b with a screw), and the distance between the start point of the spiral flow groove and the inner surface arrival position becomes equal to the inner direction. If the die ring 122a is longer than when the die ring 122a is stationary, the development angle ω increases, and if the distance is reduced by rotating in the negative direction, the development angle ω decreases. Such a mechanism makes it possible to increase or decrease the development angle of the leaking resin by changing the rotation direction of the inner die ring 122a. As a result, the number of layers in the thickness direction of the film at a specific plane position Can be increased or decreased. The degree of the increase / decrease can be increased by increasing the rotation speed of the inner die ring 122a.
[0025]
When the laminated cylindrical body extruded from the die lip 27 (FIG. 4) of the rotary spiral die 121 as described above is torn in a direction parallel to the axis similarly to the case of the fixed spiral die 21 of FIG. 3, FIG. Corresponding to (a) to (c), a laminated film having a structure as shown in FIGS. 11 (a) to (c) is obtained. In the cross section in the MD direction (FIG. 5B), the laminated film shown in FIGS. 5B and 5C has a layer arrangement in which the resin A layer and the resin B layer are almost parallel to the main surface, Only the cross section in the TD direction (FIG. 5C) shows an inclination, whereas the cross section in the MD direction (FIG. 11B) and the cross section in the TD direction (FIG. 11C) have an inclination angle θ. ₁ And θ ₂ It is characteristic that both are inclined. In general, 0 ゜ <θ ₁ , Θ ₂ The inclination angle is in the range of ≤4 °.
[0026]
Another characteristic is that, for example, the design of the spiral flow grooves 24a and 24b of the resin A and the resin B (the full width and the full depth of the spiral flow grooves) is the same. η _A Viscosity η of resin and resin B _B Is η _A > Η _B In the case of (1), as shown in FIGS. 11B and 11C, the resin A forms a surface layer on the inner surface side, and the resin B forms the surface layer on the outer surface. Where η _A = Η _B In the case of (1), as shown in FIG. 5 (c), the two resin layers A and B reach the two main surfaces, and give a striped exposed pattern of the resins A and B on both surfaces. That is, it is possible to change the surface state by changing the spiral flow path design and the melt viscosity of the inflowing resin according to the physical properties of the surface required for the obtained laminate.
[0027]
Each of these resins A and B (which may be a resin mixture or a single resin, respectively) has a melt viscosity at the processing temperature of 100 to 5000 Pa · s, preferably 300 to 2000 Pa · s, more preferably 400 to 1200 Pa.・ S is desirable.
[0028]
In the case of forming an alternating diagonal laminate using the rotating spiral die of the present invention, the resin A and the resin B have a volume ratio of the resin introduced into the spiral die of 1: 0.05 to 1:20, The ratio is preferably 1: 0.3 to 1: 3, more preferably 1: 0.6 to 1: 1.5. In addition, this volume ratio is an example in the case where spirals having substantially the same groove depth and width at the start point and end point of the spiral flow channel into which the resin A is introduced and the spiral flow channel into which the resin B is introduced are used. The volume ratio changes due to the change in the spiral flow path design including these.
[0029]
Further, it is desirable that the resin A and the resin B introduced into the spiral die have similar melt viscosities, for example, the start of the spiral channel groove in which the mixed resin is introduced and the spiral channel groove in which the single resin is introduced. When a spiral having substantially the same groove depth or width at the point and the end point is used, the melt viscosity ratio at the processing temperature is 1: 0.5 to 1: 2.0, more preferably 1: 0.6 to 1 : 1.5, particularly preferably in the range of 1: 0.7 to 1: 1.3. However, the optimum ratio of the melt viscosity can be changed by changing the spiral flow channel design such as the depth and width of the spiral flow channel.
[0030]
On the other hand, the rotation speed of the spiral mandrel (inner die ring) 122a, which is a die rotation part, is 0.05 to 100 rotations / minute, preferably 0.05 to 50 rotations / minute, and more preferably 0.1 to 20 rotations / minute. Revolutions per minute. If the number of rotations is less than 0.05 rotations / minute, it is difficult to increase or decrease the number of laminations, and it is difficult to control the number of rotations. There is a risk of galling (meshing and stuck).
[0031]
Further, the rotation direction of the spiral mandrel (inner die ring), which is the die rotating portion, may be either the positive direction or the negative direction (reverse direction) as described above, whereby the number of laminations can be increased or decreased.
[0032]
In the spiral die of the present invention, as the rotating portion, both the inner die ring 122a and the die lip 27 may be rotated, or only the inner die ring 122a may be rotated. Alternatively, only the outer die ring 122b may be rotated, or both the outer die ring 122b and the inner die ring 122a, or all of the outer die ring 122b, the inner die ring 122a, and the die lip 27 may be rotated. In particular, it is particularly preferable to rotate both the inner die ring 122a and the die lip 27, or only the inner die ring 122a, from the viewpoint of controlling the number of layers and miniaturizing the apparatus. Note that the rotation speed and the rotation direction when rotating the outer die ring may be controlled in the same manner as when rotating the inner die ring. In addition, in order to prevent metal-metal galling on the sliding surface between the inner die ring 122a and the outer die ring 122b, a difference in hardness may be provided between metal materials used for the inner die ring and the outer die ring, and a bearing may be provided. May be provided. For the same purpose, it is also preferable to provide a resin leakage port 36 (FIG. 10) so that a small amount of molten resin always leaks to the outside.
[0033]
As a method of driving the die ring, as shown in FIG. 6, instead of a method of attaching the sprocket 31 to the inner die ring 122a and connecting the sprocket 31 to the side of the spiral die with a motor 33 and rotating by a chain 32, FIG. A method in which the inner die ring 122a and the motor 33 are directly connected and rotated as shown in FIG. 12 is also used, and any of these methods may be selected as necessary. FIGS. 6 and 12 show only the method of rotating the inner die ring, but the present invention is not limited to this, and the outer die ring can be driven in the same manner.
[0034]
In the above, the alternate laminated structure (A / B / A / B / A / B...) Of two types of resins A and B has been described. However, the order of lamination of the various resin layers is arbitrary. For example, with respect to the two types of resins A and B, A / B / B / A / B / B / A... Or A / B / B / A / A / A repeating structure such as B / B / A... Is also possible. In order to obtain a laminated resin film having uniform properties as a whole, it is preferable to repeatedly perform lamination in a certain order to obtain a laminated resin molded product. It is also possible to laminate three or more resins. For example, the following is an example of the lamination order for the three resins, A, B and C.
[0035]
A / B / C / A / B / C / A ...
A / B / C / B / A / B / C / B / A ...
A / B / A / B / C / A / B / A / B / C ...,
A / B / C / B / A / B / C / B / A ...
[0036]
When a laminate is formed in accordance with the method of the present invention, the number of different resins (n; n is a natural number) different from each other, that is, the number of resin types (n) for lamination is 2 to 4, while the number of resins (m; m is a natural number and n <m) spiral channel grooves, that is, spiral channel grooves 24a, 24b, etc., the total number of spiral channel grooves (m), in other words, the number of layers (m) is 4 to It is preferable to have about 256 grooves (layers), more preferably about 8 to 128 grooves (layers), and especially about 16 to 64 grooves (layers). It is preferable to have about 500 layers. The number of layers in the thickness direction is determined as m × ω / 360 from the number m of spiral flow grooves (number of spiral grooves) and the development angle ω. The overall thickness of the laminated resin molded article can be controlled quite widely, but is preferably, for example, about 10 μm to 1 mm, particularly preferably about 15 to 200 μm. Further, at least one surface of the obtained oblique laminated resin film as shown in FIGS. 11A to 11C may be further coated with one or more resin layers of different types or the same type (with the constituent resin of the oblique laminated resin film). Preferred in many cases.
[0037]
For the purpose as described above, the spiral die of the present invention is also provided with another resin for flowing and laminating inside or outside or on both sides of the resin flow path of the spiral die of the present invention forming a laminate. It is also possible to newly provide a resin flow path. The newly provided resin flow path may be a normal non-rotating spiral die ring or a previously developed fixed spiral die for forming a laminate. In addition, the rotatable spiral die ring of the present invention can be provided inside or outside the resin flow path or on both sides thereof, and a plurality of rotating die rings may be simultaneously rotated.
[0038]
Hereinafter, a production example and a comparative example of a laminated resin film using a die corresponding to an example of the present invention will be described.
[0039]
(Example 1)
As shown in FIG. 6A and FIG. 10, a spiral die 121 for forming an oblique molded body (m = m) capable of alternately flowing two kinds of resins and rotating the inner die ring 122a in both forward and reverse directions. 32) (note that the outer die ring is fixed and non-rotating), and is co-extruded into a cylindrical shape (extrusion temperature: 180 to 210 ° C., die temperature: 200 ° C.), oblique length of 244 mm in circumference, 200 μm in thickness A laminate was produced. The extrusion temperature of each resin is shown in Table 2. At this time, the number of rotations of the inner die ring was set to 0.5 rotation / minute (rpm) in the forward direction (in the case where the spiral groove was compared to a screw, in the direction of loosening the screw). The structure of the obtained oblique laminate is such that a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as “EVOH”) is used as the resin A, and a copolymer of nylon 6 and nylon 12 (hereinafter “Ny6-12”) is used as the resin B. ), And the thickness ratio of each was EVOH = 100 μm (total thickness), Ny6-12 = 100 μm (total thickness), and the number of layers was 21 to 23. EVOH has an ethylene content of 44 mol%, a saponification degree of 99.4%, and a melt viscosity (200 ° C., 25 sec.) ^-1 ) = 901 Pa · s manufactured by Kuraray “EVAL EPE105A”. Ny6-12 has a melt viscosity (200 ° C., 25 sec.) ^-1 ) = 814 Pa · s Amilan CM6541X3 manufactured by Toray. With respect to the obtained oblique laminate, yield point stress, rupture stress, rupture elongation, and Young's modulus were measured, and the results are shown in Table 1.
[0040]
(Example 2)
An oblique laminate was manufactured in exactly the same manner as in Example 1 except that the rotation speed of the inner die ring 122a during the manufacture of the oblique laminate was set to 1 rpm in the positive direction. The number of laminations of the obtained oblique laminate was 29 to 31 layers. With respect to the obtained oblique laminate, yield point stress, rupture stress, rupture elongation, and Young's modulus were measured, and the results are shown in Table 1.
[0041]
(Example 3)
An oblique laminate was manufactured in exactly the same manner as in Example 1 except that the rotation speed of the inner die ring 122a during the manufacture of the oblique laminate was set to 2 rpm in the positive direction. The number of layers of the obtained oblique laminate was 45 to 47 layers. With respect to the obtained oblique laminate, yield point stress, rupture stress, rupture elongation, and Young's modulus were measured, and the results are shown in Table 1.
[0042]
(Example 4)
An oblique laminate was manufactured in exactly the same manner as in Example 1 except that the rotation speed of the inner die ring during the manufacture of the oblique laminate was set to 4 rpm in the positive direction. The lamination number of the obtained oblique laminate was 55 to 57 layers. With respect to the obtained oblique laminate, yield point stress, rupture stress, rupture elongation, and Young's modulus were measured, and the results are shown in Table 1.
[0043]
(Example 5)
An oblique laminate was manufactured in exactly the same manner as in Example 1 except that the rotation speed of the inner die ring during the manufacture of the oblique laminate was set to 0.1 rpm in the reverse direction. The number of layers of the obtained oblique laminate was 10 to 11 layers. With respect to the obtained oblique laminate, yield point stress, rupture stress, rupture elongation, and Young's modulus were measured, and the results are shown in Table 1.
[0044]
(Comparative Example 1)
As shown in FIGS. 3 and 4, the embodiment is performed except that a spiral die for forming an oblique molded body (m = 32, the inner die ring 22a cannot be rotated) capable of alternately inflow-molding two kinds of resins is used. An oblique laminate was manufactured in the same manner as in Example 1. The number of laminations of the obtained oblique laminate was 14 to 15 layers. With respect to the obtained oblique laminate, yield point stress, rupture stress, rupture elongation, and Young's modulus were measured, and the results are shown in Table 1.
[0045]
[Table 1]

[0046]
(Extrusion conditions)
[0047]
[Table 2]

[0048]
(Specification of spiral die used)

[Drive part]
・ Drive motor 3.0KW ES servo motor
・ Reducer worm reducer
・ Drive method Chain method
[Measuring method]
1. Breaking stress, breaking elongation, yield point stress
Based on JIS K-7127, it was measured under the following conditions using a Tensilon universal tester RTM-100 manufactured by Orientec Co., Ltd.
[0049]
・ Sample length (distance between grips) 50mm
・ Sample width 10mm
・ Cross head speed 500mm / min
・ Test temperature 23 ℃
・ Test humidity 50% relative humidity
2. Young's modulus
Based on JIS K 7127, it was measured under the following conditions using a Tensilon universal tester RTM-100 manufactured by Orientec Co., Ltd.
[0050]
・ Sample length (distance between grips) 100mm
・ Sample width 20mm
・ Crosshead speed 10mm / min
・ Test temperature 23 ℃
・ Test humidity 50% relative humidity
[0051]
【The invention's effect】
As is clear from Table 1 above, in Comparative Example 1 using the fixed spiral die, the number of layers in the thickness direction was 14 to 15 layers. In Examples 1 to 5 in which the number of rotations was changed from 1 rpm to +4 rpm, the number of laminations in the thickness direction could be widely increased and decreased from 10 to 11 layers to 55 to 57 layers, and the breaking stress and rupture of the resulting laminated film were accordingly increased. It can be seen that elongation, Young's modulus and yield point stress can be adjusted.
[Brief description of the drawings]
FIG. 1 is a sectional view of a conventional spiral die for a multilayer and a sectional view of a product film.
FIG. 2 is a perspective view and a cross-sectional view of a laminated resin film obtained by using the spiral die of FIG.
FIG. 3 is a cross-sectional view of an example of a previously developed fixed spiral die and a cross-sectional view of a product film.
FIG. 4 is a schematic perspective view of a main part of the spiral die of FIG. 3;
FIG. 5 is a perspective view and a two-way cross-sectional view of an example of a laminated resin film manufactured by the spiral die of FIG. 3;
FIG. 6 is a schematic sectional view of an example of an apparatus system including the rotating spiral die of the present invention and a sectional view of a product film.
FIG. 7 is an enlarged perspective view of an inner die ring in a portion XX of FIG. 6;
FIG. 8 is a structural diagram of a distribution section flow path of resin A inside of FIG. 7;
9 is a structural diagram of a flow path of a distribution part of the resin B inside of FIG. 8;
FIG. 10 is an axial sectional view of the rotary spiral die of FIG. 6;
FIG. 11 is a perspective view and a two-directional cross-sectional view of an example of a laminated film obtained by the rotating spiral die of FIGS. 6 to 10;
FIG. 12 is a schematic cross-sectional view of another example of the device system including the rotating spiral die of the present invention.
[Explanation of symbols]
1: laminated resin film (1a, 1b: two main surfaces thereof)
A, B: constituent resin types
10a, 10b, 10c, 20a, 20b: Extruder
11, 21: Spiral die
121: Rotating spiral die
12a, 12b, 22a, 22b: die ring
122a: Rotating inner die ring
122b: fixed outer die ring
22ab: gap flow path between inner and outer die ring
13a, 23a1, 23a2, 23a3, 23b1, 23b2, 23b3: tournament branch
14a, 24a, 24b: spiral flow channel
15a, 15b, 15c, 25: cylindrical channel
16: junction
17, 27: Die lip
28a, 28b: distribution section final flow path
31: Sprocket
32: Chain
33: Motor
34: Rotating channel cover
35: Bearing
36: Resin leak
37: Shaft

Claims (6)

The inner die and the outer die are arranged in a fitting relationship with each other, and at least one of them is rotatably arranged. A plurality (m; m is a natural number) of spiral flow grooves whose depth is reduced is formed, and a plurality (n; where n is a natural number and n <m) is formed in the plurality of (m) spiral flow grooves. Is provided in order to distribute and introduce the molten resin flows composed of different resins in a predetermined order, and the individual resin flows supplied from the inner die ring through the distribution grooves advance in the spiral flow channel. A stacked body, wherein the plurality of molten resin flows are stacked in a certain order as a leakage flow from the spiral flow channel before forming a uniform cylindrical flow in the die axial direction. Molding tool Irarudai. The spiral die according to claim 1, wherein the inner die ring is rotatable. 3. The spiral die according to claim 1, wherein m is 4 to 256 and n is 2 to 4. The spiral die according to any one of claims 1 to 3, wherein the distribution groove is provided on the inner die ring so as not to be exposed on a sliding surface with the outer die ring facing the same. The inner die and the outer die are arranged in a fitting relationship with each other, and at least one of them is rotatably arranged. At least one of the die rings is rotated in the plurality of (m) spiral flow grooves of a spiral die having a plurality of (m; m is a natural number) spiral flow grooves having a reduced depth. Then, a plurality of (n; n is a natural number, n <m) molten resin flows composed of different resins are distributed in a certain order from the inner die ring through the distribution grooves provided in the inner die ring. Introduced, before the individual resin flow proceeds in the spiral flow channel to form a uniform cylindrical flow in the die axis direction, the plurality of molten resin flows as a leakage flow from the spiral flow channel. By laminating serial in a certain order, the laminate manufacturing process, wherein the plurality resin in its circumferential cross section to obtain a laminated tubular body formed by laminating at an angle. The method according to claim 5, further comprising an inflation step for expanding and reducing the thickness of the laminated tubular body.

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