JPH10113985A - Manufacture of thermoplastic film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize no uneven thickness and the evasion of troubles such as the blocking between thin film layers by a method wherein a stretchingly laminated film after stretched and thermally fixed is simultaneously separated into respective layers under the state that a separating point is substantially fixed by a nip between a pair of rolls and then wound up by individual winders. SOLUTION: A stretchingly laminated film after stretched and thermally fixed is cooled by a roll 13 and then is peeled off and separated into a front layer film A, an intermediate separated film B and the other front layer film C under the state being pressed by a pair of rolls 14 and 14' or held by a slight gap between the rolls 14 and 14'. The above-mentioned peel forces are respectively given to the film by the peripheral speed differences between driving nip rolls 15, 16 and 17 and the roll 14 and, at the same time, cut the tensional change at the winding-up and in a grinding chamber, resulting in realizing a stable peeling off. The widthwise thickness distribution of the front layer film A after the peeling-off is measured with a thickness meter 19 and fed back in response to the deviation from the object thickness through a controlling device 29 to the controller of a die so as to control to obtain a uniform film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing two or more thermoplastic films at once, and more particularly to a method for producing two or more thermoplastic films at once.
The present invention relates to a method for producing a thermoplastic film that avoids troubles such as blocking between thin film layers when winding a film coated with a thin film, particularly an easily adhesive thin film, with at least one film having no thickness unevenness.

[0002]

2. Description of the Related Art As a method for producing a plurality of films made of a thermoplastic resin all at once for the purpose of improving productivity, a method of stretching an amorphous laminated film coextruded with a peeling spacer as an intermediate layer and then peeling the film into each layer. (For example, Japanese Patent Application No. 49-1
No. 04564, JP-A-61-31236) and a method using no spacer (JP-A-6-305016) are known.

However, it is difficult to recover the film edge by the method disclosed in Japanese Patent Application Laid-Open No. 61-31236, it is difficult to control the thickness unevenness by the method disclosed in Japanese Patent Application No. 49-104564. However, the method (1) has a problem in that a plurality of films are manufactured using separate dies and cooling drums, and the degree of crystallinity is controlled.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to
In order to solve the above-mentioned problems of the prior art, there is no unevenness of thickness, and when winding a film coated with a thin film, particularly an easily adhesive thin film, two or more thermoplastic films are simultaneously used to avoid troubles such as blocking between thin film layers. It is to provide a manufacturing method.

[0005]

According to the present invention, it is an object of the present invention to laminate and extrude mutually incompatible thermoplastic resins and rapidly cool them to form an amorphous laminated film, which is uniaxially stretched or biaxially stretched. Stretching, heat-fixing and taking over, stretching,
Producing a thermoplastic film, wherein the stretched laminated film after heat setting is substantially fixed at a peeling point between a pair of rolls, and the respective layers are simultaneously peeled off, and then each single-layer film is wound up by an individual winder. Achieved by the method.

In the present invention, mutually incompatible thermoplastic resins are co-exposed so that a product film layer and an incompatible resin layer (separation spacer) are alternately laminated. The film is extruded and quenched to form an amorphous laminated film, which is then stretched and heat-set. Preferably, the co-extrusion die is capable of independently controlling the thickness of each layer in the width direction. Further, it is preferable that the extrusion amount of the molten thermoplastic resin in each layer can be controlled independently. In addition, the stretched laminated film that has been stretched and heat-set is peeled at a nip point of a pair of rolls or at a relatively narrow gap point of a pair of rolls at substantially the same time and a plurality of films are peeled off. It is preferable to measure the thickness profile in the width direction and feed back the deviation of the target thickness to the above-mentioned thickness control die to make the thickness uniform.

[0007] In the present invention, each layer is peeled after stretching and heat setting. This makes it possible to recover the edge of the product film as before, and the entire amount of the film extruded as a spacer can be recovered, so that it can be effectively reused. It becomes possible. Furthermore, in the present invention, in the case of a three-layer film in which a product film is extruded on both surface layers of one release spacer,
It is also preferable that the unstretched laminated film or the uniaxially stretched laminated film is subjected to easy adhesion in-line coating on both sides and wound. Generally, when a film having an easy-adhesion layer on both sides is wound up, a phenomenon in which the easy-adhesion layers adhere to each other is observed, but in the present invention, since the film is peeled off as a single-layer film as described above, it is easily wound. Since the adhesive layers and the non-easily adhesive layers are alternately arranged, the sticking phenomenon is eliminated and the two product films are simultaneously subjected to one-side coating, so that a significant improvement in productivity can be realized.

In the present invention, the thermoplastic resin may be any resin as long as it can be extruded into a sheet or a film. For example, polyolefins such as polyethylene and polypropylene, and chlorine-containing polymers such as polyvinyl chloride and polyvinylidene chloride. Polyamide such as nylon 6, nylon 66, polyester such as polyethylene terephthalate, polyethylene naphthalate, polyether resin such as polycarbonate, polyetherketone, polyetheretherketone, and sulfone resin such as polysulfone sulfide. Can be mentioned. As the incompatible resin to be combined with these resins, polyamide, polyester, polyether, and polysulfone are preferable as the incompatible resin for polyolefin, and for the chlorine-containing polymer, polyamide, polyester, polyether, and polysulfone are preferable. Sulfone is preferred, and for polyamide, polyolefin, polyester, polyether and polysulfone are preferred,
For polyester, polyolefin, polyamide,
Polyether and polysulfone are preferable, and polyolefin, polyamide, polyester and polysulfone are preferable as the polyether resin. The laminated film of these combinations in which a combination of a polyester and a polyolefin is particularly preferable is that the film is adhered without peeling in the co-extrusion step and the subsequent uniaxial stretching and biaxial stretching steps. It is desirable that the film be easily peeled in a peeling step for use as a film. The preferable peel tension is 0.1 g / cm or more and 50 g / cm or less.

For the peeling after stretching and heat fixing in the present invention, a stable method is required which does not cause static electricity damage such as breakage or peeling electrification against a certain high adhesive force. For this purpose, it is preferable that the peeling points of the respective layers are peeled off in a horizontal line in the width direction, and it is necessary to use a press roll for mechanically fixing the peeling points as described above. Further, it is preferable that the take-up tension of each layer film after peeling is slightly higher than the adhesion between the layers. If the tension is too low, the peeling point moves downstream, and the peeling point shifts in the width direction, leading to a tearing phenomenon of the film, which is not preferable. If the peeling tension is sufficiently higher than the adhesion between the films, the peeling point is fixed at the roll nip point.However, in the case of a thin film, high tension may be cut indiscriminately. is there. In this case, it is preferable to blow pressurized air between the film layers toward the peeling point so that the peeling point is stably fixed even if the peeling tension is slightly higher than the adhesion force.

[0010] When a highly insulating resin film is peeled off, peeling charging generally occurs, causing an electrostatic failure such as an electrolet. As a countermeasure for this, it is effective to blow the pressurized air with ionized air, thereby effectively removing the peeling charge.

Hereinafter, the present invention will be further described with reference to the drawings. FIG. 1 is a side view of a manufacturing process of a laminated film showing one embodiment of the present invention, and FIG. 2 is a cross-sectional view of an extrusion die capable of adjusting the thickness in the width direction of each layer of the laminated film.

In FIG. 1, 1 is an extruder for extruding a product film, 2 is a first filter, and 3 and 3 'are metering pumps for controlling the discharge amount of each surface layer. (Thickness or different thickness). In addition, 3, 3 'can be replaced with a throttle valve. Reference numerals 4 and 4 ′ denote surface second filters. Reference numeral 5 denotes a release film extruder, 6 denotes a metering pump, and 7 denotes a filter. Reference numeral 8 denotes an extrusion die, which has a function of laminating a product film and a release film and controlling the thickness of each layer in the width direction.

The extrusion die will be described in more detail with reference to FIG. 2. Reference numeral 31 denotes a release resin manifold. The flow rate adjustment in the width direction is performed by pushing and pulling the thin plate forming the flow gap 32 by the heat bolt type thermal expansion / contraction actuator 33, and a plurality of the thin plates can be installed in the die width direction to adjust the thickness. Reference numeral 33 'denotes a similar heat bolt type actuator which is arranged opposite to or in a zigzag manner.

The thermoplastic resin as a product film flows to the manifolds 35 and 35 ', and the gap of the gap 36 may be adjusted by a heat bolt as described above, or by changing the resin viscosity according to the temperature as shown in FIG. When adjusting the flow rate, the heater 37 close to the gap 36, 36 ',
37 'can be adjusted by arranging a plurality of 37' in the die width direction. It is preferable that the flow path after the molten resin joins in layers is shorter, and therefore, the resin outlet 39 from the junction 38 of each layer is preferred.
Is preferably as short as possible, specifically 0 mm
From about 20 mm. When the distance is long, the adjustment effects of the respective layers interfere with each other, and the adjustment ability is reduced.

Referring back to FIG. 1, the laminated film is rapidly cooled to a non-crystalline state by a cooling drum 9 and then longitudinally stretched 10, transversely stretched 12, and thermally fixed. In this example, an example is shown in which coatings 11 and 11 'are applied to both surfaces of the laminated film after longitudinal stretching, but in the case of simultaneous biaxial stretching in the vertical and horizontal directions, the unstretched film before stretching may be coated. The stretched laminated film after stretching heat setting is roll 13
After being cooled, the film is separated and separated into a surface film A, an intermediate release film B, and another surface film C by a pair of rolls 14 and 14 ′ while pressing or having a slight gap. This peeling tension is imparted by the peripheral speed difference between the drive nip rolls 15, 16, 17 and the roll 14, respectively, and at the same time, the fluctuation in the tension from winding and grinding in the post-process is cut to enable stable peeling. In addition, when the laminated film is peeled, generally, strong peeling charge is often generated, which causes electrostatic damage such as irregular discharge marks.
For this reason, it is preferable that the ion-exhausting ion wind is blown into the respective peeling points by the nozzles 18 and 18 'toward the film peeling points. The thickness distribution of the surface film A in the width direction is thereafter measured by a thickness gauge 19 (for example, a β-ray thickness gauge), and is fed back to the die controller 37 ′ via the control device 29 in accordance with the deviation of the target thickness, and is uniform. Can be adjusted to a suitable film. The film A is wound by a winder 21 after cutting the edge 20. In addition, a case is shown in which the spacer film B is recovered without being commercialized after peeling. Since this film does not become a product, the thickness uniformity does not need to be as strict as the product level.However, if there is a large thickness deviation in the spacer film during stretching heat setting, a temperature difference will occur in the heating and cooling process, and it will adhere to this. The temperature distribution of the product film also changes, resulting in non-uniform physical properties such as orientation physical properties and crystallinity, so that a certain degree of thickness control is required. In this example, the optical interference film thickness meter 22 is installed so as to be able to scan in the width direction, and the control output is changed according to the measured thickness deviation to the thickness of the middle layer of the die.
To adjust the thickness profile in the width direction. The spacer film may be once wound up, but as an example of efficiently collecting and regenerating, the suction ejector 25 shown in FIG.
, It is preferable to transport directly to a pulverizer or a regenerated granulator. When the spacer film is wide, it may be difficult to convey the film if it is a full-width film. It is preferable that the film is appropriately cut in the width direction, bent or bundled, and then conveyed. For this reason, the cutter 23 and the squeeze guide 24 are illustrated in this example. The other product surface film C is measured by the thickness gauge 26 in the same manner as the film A, and the deviation is adjusted by the die control heater 37 in FIG. The film C is wound up by a winder 28 after the edge trimming of 27.

FIG. 1 shows an example of peeling of a three-layer laminate. For example, a five-layer laminate film in which two release films and three product films are alternately sandwiched is stretched and heat-fixed, and peeled into a single-layer film. Separation is also useful as one embodiment of the present invention.

According to the present invention, a plurality of thermoplastic films can be manufactured at once as described above. Further, even when a plurality of product films are rolled up without unevenness in thickness and easily applied and coated, In addition, it is possible to avoid defects due to blocking between coating layers and the like, and it is possible to produce a high-quality film while securing significant productivity.

A feature of the present invention is that a great effect can be obtained by first peeling and winding the film after stretching as described above. Next, the thickness of the product film can be easily measured by forming the product film into a single-layer film, and a product film having a small thickness deviation can be obtained by combining with a die capable of adjusting the thickness distribution of each layer. Further, the film edge can be easily collected as before. Further, a major feature of the present invention is that, for example, a product film is extruded on both sides of a release film to form a three-layer film, and the unstretched or uniaxially stretched film is coated with easy-adhesion on both sides.
Although the product film after peeling is a one-sided coating, it can be coated at the same time, and a large improvement in productivity can be obtained. Further, generally, the easily adhesive coat layer has a problem that when the coat layers are pressed by winding or the like, they easily adhere to each other and cause a blocking phenomenon. However, according to the method of the present invention, the product film When is wound, the adhesive layer and the non-adhesive layer are opposed to each other, so that there is no blocking phenomenon, and a production system that is compatible with high productivity and high quality can be provided.

On the other hand, as a method for treating a release film (spacer film) of an intermediate layer which does not become a product, it may be wound up as it is, but it is preferable from the viewpoint of environmental conservation to collect or recycle these films without discarding them. . Therefore, it is preferable to directly convey and collect in a step of directly grinding or granulating and regenerating without winding.

[0020]

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

Example 1 Polyethylene-2,6-naphthalate (PEN) was used for both surface layers, and polypropylene (P
A three-layer film having P) as an intermediate layer is co-extruded with a three-layer die shown in FIG. 2, quenched to form an amorphous laminated film, and then stretched 3.6-fold at 110 ° C. in one axis direction. Both sides are coated with an easy-coating agent, and the stretching temperature is 1
The film was stretched 4.7 times in the transverse direction at 30 ° C., and further heat-set at 210 ° C. to obtain a three-layer thin film-coated stretched laminated film having a thickness of 5.5 μm / 3.5 μm / 5.5 μm. The peeling tension of the surface layer PEN was 1 kg / m and the peeling tension of the middle layer PP was 0.5 kg / m.
m, and ionized pressurized air was separated under the condition of blowing at a wind speed of 15 m / sec to obtain a good product roll of a PEN film without breakage or static electricity damage. At the above-mentioned heat setting temperature, the polypropylene film of the intermediate layer becomes nearly non-oriented and easily breaks. However, by reducing the take-up tension of the polypropylene film after peeling to 0.3 Kg / m after the nip roll 16, breakage may occur. And stable transport was possible, and suction was possible with the ejector.

[Comparative Example 1] A biaxially oriented three-layer film coated with the same double-sided adhesive film as in Example 1 was wound up into three sheets without being peeled off. The films partially adhered and blocked, resulting in significant quality defects.

[0023]

According to the present invention, a plurality of thermoplastic films can be manufactured at once, and furthermore, a plurality of films can be easily trimmed without unevenness in thickness, loss of resin material is small, and Troubles such as blocking between the coating agents can be avoided even when the film coated with the easy-to-adhesive film is wound up, and a high-quality film can be manufactured while securing significant productivity.

[Brief description of the drawings]

FIG. 1 is a side view of a film manufacturing apparatus showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view of a die for laminating a three-layer film showing one embodiment of the present invention.

[Explanation of symbols]

 1: Extruder for product film 2: First filter 3: Metering pump 4: Second filter 5: Extruder for spacer film 6: Metering pump 7: Filter 8: Die 9: Cooling drum 10: Vertical stretching machine 11: Inline Coater 12: Horizontal stretching machine 13: Cooling roll 14: Peeling roll 15, 16, 17: Peeling tension control roll 18: Ion wind nozzle 19: Thickness gauge 20: Edge trim film 21: Winder 22: Optical interference thickness gauge 23: Cutting Blade 24: Squeeze guide 25: Suction ejector 26: Thickness gauge 27: Edge trim film 28: Winder 29: Thickness controller 31: Release resin manifold 32: Thickness adjustment gap 33: Heat bolt actuator 35: Product resin manifold 36: Thickness Adjustment gap 37: Thickness control heater 3 : Confluence 39: laminated resin exit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B29D 7/00 B29D 7/00 // B29K 101: 12 105: 26 B29L 7:00 (72) Inventor Masahiro Niguchi Sagamihara, Kanagawa 3-37-19 Koyama-shi, Sagamihara Research Center, Teijin Limited

Claims (5)

[Claims] 1. An mutually incompatible thermoplastic resin is alternately laminated and extruded and rapidly cooled to form an amorphous laminated film, which is stretched uniaxially or biaxially, and then heat-fixed to draw it. A method for producing a thermoplastic film, wherein the stretched laminated film after fixing is peeled at the same time with a pair of rolls substantially fixing a peeling point and each layer is simultaneously peeled off, and then each single-layer film is wound up by an individual winder. . 2. Laminate extrusion of a thermoplastic resin is performed by an extrusion die having a function of adjusting the amount of extrusion and the thickness in the width direction independently of each layer, and after the stretched laminated film is peeled into a single layer, the thickness distribution in the width direction of each single-layer film. The method for producing a thermoplastic film according to claim 1, wherein the thickness is controlled by a function of adjusting the extrusion amount of each layer and / or the thickness in the width direction of each layer with respect to a deviation from a target value. 3. A thin film forming coating solution is applied to both sides of an amorphous laminated film or a uniaxially stretched laminated film, and then dried,
The method for producing a thermoplastic film according to claim 1 or 2, wherein the film is stretched and heat-set to form a thin film-coated stretched laminated film, and then the stretched laminated film is peeled into a single layer. 4. The method for producing a thermoplastic film according to claim 1, wherein at least one single-layer film, which is not a product, is recovered for re-extrusion of the plurality of single-layer films peeled from the stretched laminated film. 5. A plurality of single-layer films peeled off from the stretched laminated film, wherein at least one single-layer film not formed as a product is sucked and conveyed or wound up without winding, granulated as required, and re-extruded. The method for producing a thermoplastic film according to claim 1, wherein the thermoplastic film is recovered for use.