JPH09314776A - Separation of multilayer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the peeling and the separation of thin film to be stably performed without causing breaking and qualitative defect by holding or fixing a separable spot with the help of a pair of rolls in a method for separating one of the adjacent faces of a multilayer film. SOLUTION: A raw film 1 for a multilayer film is caused to pass through a scroll 2 and a tension detecting roll 3 for detecting a feed tension and adjusting a brake torque. In addition, a drive roll 4 for fixing a separation point and a nip roll 5 are provided. From a formed nip A point, three pieces of film are peeled as a finished product 1, an intermediate model film 2 comprising a non-compatible resin and another finished product 3. The tension of each of these three pieces of the film is preferably higher than an interlayer adhesion between the pieces of the film. Further, the tension of the film 1 is given by a difference in the peripheral speed between the roll 4 and a roll 6. Besides, the tension of the film 2 is likewise set by a difference in the peripheral speed between the roll 4 and a roll 7 and the tension of the finished product 3 is set by a difference in the peripheral sped between the roll 4 and a roll 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for separating a multi-layer film, and more particularly to a method for separating a plurality of single-layer films and / or multi-layer films from the multi-layer film. In particular, even if the single-layer film and / or the multi-layer film separated from the multi-layer film is a thin film having a thickness of several tens of μm or less, there are obstacles such as breakage during film take-up and wrinkles during film winding. The present invention relates to a method capable of preventing damage due to static electricity charged on a film or a film and enabling high-speed and efficient separation.

[0002]

2. Description of the Related Art A multilayer film made of a thermoplastic resin is formed by various methods such as a coextrusion method and a laminating method. The purpose of such a multilayer film is, for example, to obtain a so-called dual surface in which a magnetic layer is flattened and a running surface is roughened in a base film for a magnetic recording tape, and in a packaging film, a layer having a barrier property and low temperature easy adhesion It is possible to cite a method of obtaining a film having both sides with a layer having a property.

In recent years, thin films having a thickness of several tens of μm or less have been used as a base film in applications such as capacitors, stencil printing and printer thermal printing ribbons. Since there is a tendency for breakage to occur, the productivity is extremely low.
In order to improve such defects, a thin film of interest and a multilayer film of a thermoplastic film incompatible with it are produced by coextrusion, and the thin film of interest is peeled and separated from the obtained multilayer film. Method (for example, JP-A-58-5226, JP-A-60-163419)
JP-A-58-132520, JP-A-58-52520
-136417, JP-A-57-176125 and JP-A-52-37982) have been proposed.

However, in these methods, when the thin film is peeled and separated from the multi-layer film, the peeling may not be smoothly performed due to the fluctuation of the peel strength and the fluctuation of the film thickness. Defects such as wrinkles occur, and, if significant, defects such as breakage of the thin film occur.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide a method for separating a multi-layer film which has improved the above-mentioned drawbacks, that is, to cause breakage and quality defects in a thin film obtained by peeling and separating from the multi-layer film. An object of the present invention is to provide a method capable of stably performing peeling separation without using the method.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
According to the present invention, a multilayer film having at least one layer of the (A) layer made of the thermoplastic resin A and at least one layer of the (B) layer made of the thermoplastic resin B is adjacent to the adjacent layer. In the method for separating at least one surface of the above, the method for separating a multilayer film is characterized in that the place where the adjacent surface separates is substantially gripped or fixed by a pair of rolls.

Hereinafter, the present invention will be described in more detail.

[Thermoplastic Resin] The thermoplastic resin A and the thermoplastic resin B in the present invention may be any resins as long as they can be extruded into a sheet or a film, for example, a polyolefin resin such as polyethylene or polypropylene. Resins containing chlorine, such as polyvinyl chloride, polyvinylidene chloride, nylon 6, nylon 66
Such as polyamide resin, polyethylene terephthalate, polyester resin such as polyethylene naphthalate, polycarbonate resin, polyether ketone, polyether resin such as polyether ether ketone, polysulfone resin such as polyphenyl sulfone, poly (p-phenylene) Examples thereof include polyarylene sulfide resins such as sulfide) and resins obtained by copolymerizing a copolymerization component with these resins.

The thermoplastic resin A (hereinafter abbreviated as "resin A") and the thermoplastic resin B (hereinafter abbreviated as "resin B") in the present invention can be selected from the above resins and the like. The resin B is preferably a thermoplastic resin which is substantially incompatible with the resin A.

For example, when a polyolefin resin is used as the resin A, a polyamide resin, a polyester resin, a polyether resin or a polysulfone resin which is incompatible with polyolefin can be preferably used as the resin B.

When a resin containing chlorine is used as the resin A, a polyamide resin, a polyester resin,
It is preferable to use a polyether resin polysulfone resin, and when a polyamide resin is used as the resin A,
Polyolefin resin, polyester resin,
It is preferable to use a polyether resin or a polysulfone resin.

When a polyester resin is used as the resin A, it is preferable to use a polyolefin resin, a polyamide resin, a polyether resin or a polysulfone resin as the resin B.

[Multilayer Film] As the multilayer film in the present invention, those obtained by a conventionally known method (for example, a coextrusion feed block method, an extrusion laminating method, etc.) can be used. The adjacent surfaces of the (A) layer and the (B) layer in these multilayer films adhere to each other without peeling in each step such as the coextrusion step or the extrusion laminating step and the subsequent uniaxial stretching step and biaxial stretching step. In the peeling step for separating a plurality of single-layer films and / or multi-layer films from the multilayer film, the adjacent surfaces of the (A) layer and the (B) layer can be easily peeled off. Is desirable. As such a multilayer film, (A)
Adhesion between the layer and the adjacent surface of the layer (B) is 0.1 to 20 g / cm
It is preferable that

[Separation Method] In the present invention, at least one of the adjacent surfaces is separated from a multilayer film having an adjacent surface where at least one layer (A) and at least one layer (B) are adjacent to each other. In doing so, a portion where the adjacent surfaces are separated is substantially gripped or fixed by a pair of rolls (roll nip).

By substantially gripping or fixing the separated portions with a pair of rolls, a multilayer film manufacturing process, for example, a coextrusion process or an extrusion laminating process,
In each of the subsequent uniaxial stretching step, biaxial stretching step and the like, even if the adjacent surfaces of the (A) layer and the (B) layer have such adhesiveness that they do not peel off, the film is stably broken or peeled off. It is possible to separate a plurality of single-layer films and / or multi-layer films from a multilayer film without causing electrostatic troubles such as charging. In addition, the peeling point of each layer can be peeled in a horizontal line in the width direction by substantially gripping or fixing the separation point with a pair of rolls.

The take-up tension of each layer after separation is preferably higher than the adhesion between the layers. If the take-up tension of each layer is lower than the adhesion force between the layers, the separation point moves to the downstream side (the film advancing direction), and the separation point shifts in the width direction, leading to the phenomenon that the film is torn, which is not preferable. . If the separation tension is sufficiently higher than the adhesive force between the films, the peeling point is fixed at the roll nip point, but if the separated film is thin,
If the separation tension is excessively increased, the film may be cut, and it is necessary to set the tension moderately.

In the present invention, it is preferable to blow the pressurized air toward the location where the adjacent surfaces are separated. By blowing the pressurized air, the separation point is stably fixed even if the separation tension is slightly higher than the adhesive force between the films. In addition, it is preferable that the pressurized air is blown toward the separation point of the film from the traveling direction side of the film.

Further, when the highly insulating resin film is separated, peeling charging generally occurs, and this charging causes electrostatic trouble such as electrolet. As a solution to this, by blowing the pressurized air into ionized air, the peeling charge can be effectively eliminated.

As an application of the present invention, it is possible to secure a dramatic productivity by slitting a film into slits to a desired product width and length and simultaneously performing peeling and slitting.

Further, as a method for treating a single-layer film separated from a multi-layer film and / or a film which does not become a product in a multi-layer film, it is preferable to collect or recycle without discarding it in view of environmental protection. As such a treatment method, the film may be wound up as it is, but it is preferable to directly convey the film to the step of directly crushing or granulating without winding the film and effectively collect the film.

The present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a multi-layer film separating apparatus showing one embodiment of the present invention, and FIG. 2 is a partial plan view of a part of the separating apparatus seen from above.

In FIG. 1, reference numeral 1 is an original film of a multilayer film. In this example, a three-layer multilayer film is illustrated. Reference numeral 2 is a wrinkle-rolling roll, and 3 is a tension detection roll for detecting the unwinding tension and adjusting the brake torque and the like of 1.
Reference numerals 4 and 5 are a drive roll and a nip roll for fixing the separation point of the present invention. From the nip point A formed by 4 and 5, the three films are peeled off to the other product of the product and the intermediate release film made of an incompatible resin. It is preferable that each of the film tensions of, and is higher than the adhesive force between the film layers. The tension of the film is applied by the difference in peripheral speed between the roll 4 and the roll 6. Similarly, the tension of the film is set by the rolls 4 and 7, and the tension of the film is set by the peripheral speed difference between the rolls 4 and 8. In addition, between the film and the layer, by the ionized pressurized air nozzle 9,
The film is blown over the entire width toward the separation point A. This effectively prevents the charging that occurs during peeling.
Furthermore, when the peeling tension of each film is broken, etc., if it cannot be applied sufficiently, the peeling point tends to shift to the downstream,
The effect of blowing this up and fixing it at point A can be imparted.
As a result, even a thin film that is easily broken can be separated very stably with a relatively low tension. The product film moves to the winding after passing through the roll 6 which gives the peeling tension, but because the tension is cut with the winding, the pressing roll 6a is installed on the 6 rolls. Next, the film is wound by the product winding shaft 13 via the winding tension detecting roll 11 and the winding air squeeze roll 12.

In this example, the film is wound in the full width, but it may be wound in plural while slitting in the width direction as shown in FIG. FIG. 4 is a partial plan view of FIG. 3 looking up from below. 22 shows a slit blade. Similarly, the other product film is wound around the product winding shaft 16 via the peeling tension imparting roll 8, the tension cutting nip 8a, the winding tension detecting roll 14, and the air squeeze roll 15. The intermediate layer film passes through the peeling tension imparting roll 7, is once cut into a small width by the cutters 17a and 17b, and is taken up by the suction ejector 20 through the transfer rolls 18 and 18a. The reason why it is cut into a small width is to smoothly carry out suction transfer, as shown in FIG. 2, so that the suction ports 21a, 21b, 21c can be easily inserted, and the film is converged by the squeeze guides 19a, b, c. Is also good. After the suction ejector is transferred, it is recycled through a crusher, a granulator, or a recycling extruder (not shown). In some cases, the intermediate film can be used as a product, and it can be wound in the same manner as the product film without being recycled. This separating device uses rubber rolls and press rolls 6a, 8a, 12, 15
Since static electricity is generally easily generated at the exit of this roll, it is preferable to install a static eliminator on each of them.

Although FIG. 1 shows an example in which three sheets are peeled off, it is also possible to separate four layers of original fabric by a combination of 1 sheet + 1 sheet + 2 sheets. For example, in FIG. 1, the product can be separately wound in a state of one layer, one layer, and two layers. Further, it is also possible as an application of the present invention to separate a five-layer original sheet into a single layer as shown in FIG.

According to the method for separating a laminated film of the present invention, particularly a thin film having a thickness of 20 μm or less can be separated at high speed without breakage or electrostatic damage, and a great improvement in productivity can be obtained.

[0027]

The present invention will be further described with reference to the following examples.

[Example 1] Polypropylene-2,6-naphthalate (hereinafter abbreviated as "PEN") was used as both surface layers, and polypropylene (hereinafter abbreviated as "PP").
The three-layer film having the layer consisting of 3 as an intermediate layer was coextruded on a rotating cooling roll using a three-layer coextrusion extruder as a feed block for an extruder to obtain a three-layer unstretched film.
Then, this unstretched film is stretched in the machine direction and in the cross direction.
The thickness of each layer is 3.5 μm /
A 3.5 μm / 3.5 μm three-layer multilayer film was obtained.

Next, from the obtained multilayer film, both PE
The N layer and the PP layer were separated by the separating device shown in FIG. 1 so that the unwinding tension was 1 Kg / m and the peeling tension between both PEN layers was 0.5 Kg / m.
m, and the air velocity of the ionized pressurized air was 15 m / sec, and both PEN layers were wound into a roll as a PEN single layer film. Moreover, the single layer film of the PP layer was sucked by an ejector and further crushed in a crushing step.

In separating the above-mentioned multilayer film, good PEN can be obtained without causing film breakage or electrostatic damage.
A roll (product) of a single layer film was obtained. At the stretching temperature and heat setting temperature suitable for PEN, the polypropylene of the intermediate layer is close to non-oriented and easily broken in a thin film.
The peeling tension of the P layer was set to 0.3 kg / m and the action of blowing the pressurized air enabled stable separation without breakage, and the suction by the ejector could be carried out without any problem.

[0031]

According to the method for separating a multilayer film of the present invention, a single-layer thin film (product film) can be stably peeled and separated from the multilayer film without causing breakage or quality defects, and the productivity of the thin film can be improved. Can be significantly improved. Further, the winding form of the resin film can be changed according to the purpose of the next step, and the unnecessary intermediate film can be separated without any trouble.

[Brief description of drawings]

FIG. 1 is a side view of a separation device showing one embodiment of the present invention.

FIG. 2 is a partial plan view of a portion for taking up the intermediate layer in FIG.

FIG. 3 is a side view of an embodiment with another slit of the separation device of FIG.

FIG. 4 is a partial plan view of the separation device of FIG.

FIG. 5 is a side view of a five-layer film separating device showing one embodiment of the present invention.

[Explanation of symbols]

 1: Original fabric of laminated film 2: Wrinkle straightening roll 3: Release tension detecting roll 4: Separation roll 5: Separation point fixing nip roll 6, 7, 8: Peeling tension imparting roll 6a, 7a, 8a: Pressing roll 9, 10: Ionized pressurized air blowing nozzle 11, 14: Winding tension detecting roll 12, 15: Air squeeze roll 13, 16: Product winding shaft 17: Intermediate layer film cutter 18: Transfer roll 18a: Transfer roll nip 19: Squeeze guide 20: Suction ejector 21: Ejector suction port 22: Slit blade 23: Roll with groove, transfer drive roll 25, 28: Rolling tension detecting roll 26, 29: Air squeeze roll 27, 30: Product winding shaft: Product film: Intermediate separation Mold film: Product film: Intermediate release film: Product film Beam

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Niguchi 3-37-19 Koyama, Sagamihara-shi, Kanagawa Teijin Limited Sagamihara Research Center

Claims (11)

[Claims] 1. A multi-layer film having at least one adjoining surface in which at least one layer (A) made of a thermoplastic resin A and at least one layer (B) made of a thermoplastic resin B are adjacent to each other. In a method of separating at least one side,
A method for separating a multilayer film, characterized in that a portion where the adjacent surfaces are separated is substantially gripped or fixed by a pair of rolls. 2. The method for separating a multilayer film according to claim 1, wherein the thermoplastic resin B is a thermoplastic resin which is substantially incompatible with the thermoplastic resin A. 3. At least one layer of the (A) layer and / or the (B) layer is a non-oriented film, a uniaxially stretched film and 2
The method for separating a multilayer film according to claim 1, which is one of the films selected from the group consisting of axially stretched films. 4. The method for separating a multilayer film according to claim 1, wherein the thickness of at least one of the layer (A) and / or the layer (B) is 20 μm or less. 5. The method for separating a multilayer film according to claim 1, wherein pressurized air is blown toward a position where the adjacent surfaces are separated. 6. The method for separating a multilayer film according to claim 5, wherein the pressurized air is ionized pressurized air. 7. The method for separating a multi-layer film according to claim 1, wherein at least one of the single-layer film and the multi-layer film separated from the multi-layer film is wound with a width substantially the same as that of the multi-layer film. 8. The method for separating a multilayer film according to claim 1, wherein at least one of the single-layer film or the multilayer film separated from the multilayer film is slit into a film having a width narrower than the width of the multilayer film and then wound. 9. At least one selected from the group consisting of a suction conveyance process, a take-up pulverization process, a granulation recovery process and an extrusion regeneration process without winding at least one of a single-layer film or a multi-layer film separated from a multilayer film. The method for separating a multilayer film according to claim 1, wherein one treatment is performed. 10. The method for separating a multi-layer film according to claim 7, wherein at least one of the single-layer film or the multi-layer film separated from the multi-layer film is subjected to static elimination treatment from the peeled portion to the winding. 11. Without winding at least one of a monolayer or multilayer film separated from a multilayer film,
10. The method for separating a multilayer film according to claim 9, wherein the static elimination treatment is performed before at least one treatment selected from the group consisting of suction conveyance treatment, take-up pulverization treatment, granulation collection treatment and extrusion regeneration treatment.