JP4574260B2 - Manufacturing method of resin film and edge pinning device for resin film molding - Google Patents

Description

The present invention uses an edge pinning device to control the neck-in of the molten resin extruded from the T-die, to ensure tight adhesion to the cooling roll, and to make a film or sheet excellent in surface gloss, transparency, etc. The present invention relates to a method for producing a resin film and an edge pinning device used therefor.

  As one of the manufacturing methods (molding methods) for thermoplastic resin films, the film extrusion molding method in which molten resin is extruded into a film form from a flat die (T-die) such as a straight mold or a coat hanger mold is a high-speed moldability. Widely used because it is excellent and has excellent thickness accuracy and transparency, and is widely used for the production of films such as single-layer and multi-layer films, and extrusion laminate molding that laminates molten resin on a substrate. Yes.

  By the way, when the molten resin is extruded (flowed down) from the die, a phenomenon called neck-in occurs. This neck-in is generated by the combined action of surface tension, melt elasticity, and tensile stress (take-off speed) in the take-up direction of the molten resin extruded from the die. It is a phenomenon that always occurs, although there are some differences depending on the type, molecular weight, and molecular weight distribution.

In addition, with this neck-in, an ear shaking phenomenon occurs in which both ends of the extruded molten resin undulate.
Controlling the neck-in generated during the production of the thermoplastic resin film, that is, keeping the width of the neck-in constant is an important item for improving the productivity of the film, especially at the start of film production, or When a trouble occurs, it is important how to stabilize the amount of neck-in that occurs quickly.

  As an apparatus for stabilizing such a neck-in, for example, as shown in Patent Document 1 (Japanese Patent Laid-Open No. 61-246035), a neck-in control apparatus having an induction guide at a resin extrusion port of a flat die, or a flat An apparatus for stably adhering the molten resin to the surface of the cooling roll by blowing air onto the surface of the cooling roll from a thin pipe and / or a pipe having a large number of small holes at the tip to both ends of the molten resin extruded from the die ( Edge pinning devices) have been proposed. For example, as shown in FIG. 7, this edge pinning device can move back and forth with respect to the cooling roll 103 on a base 101 having a nozzle position adjustment function that can move in the width direction and up and down of the cooling roll 103. The nozzle position adjusting device 105 is provided, and the nozzle position adjusting device 105 holds the three-dimensional movable pipe 107 and the three-dimensional movable porous nozzle 109 so that the molten resin 112 extruded from the T die 110 reaches the cooling roll 103. At that time, air is blown to both ends of the molten resin 112 to reduce the neck-in of the molten resin.

However, since such a neck-in control device creates a gap between the attraction guide and the cooling roll, the neck-in width may fluctuate when surging occurs during extrusion of the molten resin. In addition, a device that blows air from the thin pipe and / or the pipe having many small holes at the tip to the surface of the cooling roll to stably adhere the molten resin to the surface of the cooling roll can be used when the molding is stable. There is no problem, but when surging occurs at the start of molding or when the molten resin is extruded, the molten resin is arranged so that the molten resin is stabilized on the surface of the cooling roll. This adjustment is very difficult, and there is a problem that this adjustment requires skill.
JP-A-61-246035

In the present invention, when the molten resin is wound around a rotating cooling roll and formed into a film shape, the type of the molten resin, the forming speed is changed, or the air outlet position of the edge pinning device is appropriately changed at the start of forming. Another object of the present invention is to provide a variable edge pinning device capable of stabilizing the direction of gas flow so that the molten resin can be stably adhered to the surface of the cooling roll.

  Another object of the present invention is to provide a method for stably producing a resin film by bringing a molten resin extruded from a die in a stable state as described above into close contact with a cooling roll.

The production method of the resin film of the present invention, when the molten resin extruded from the die is taken on the outer peripheral surface of the cooling roll and cooled and solidified to produce a resin film,
Extension of a straight line (G) connecting the contact point (a) of the cooling roll to which the molten resin adheres and the rotational axis center point (P) of the cooling roll at a position where the tip is a nozzle. An adhesive force is provided along the straight line (G) from the tip of the nozzle so that the molten resin film is brought into close contact with the surface of the cooling roll by the gas flow flowing along the straight line (G) from the tip of the nozzle. And holding the nozzle at the tip of the adhesion force forming means so as to be movable back and forth along the straight line (G) toward the rotational axis center point (P) of the cooling roll. Using an edge pinning device having a holding member that holds a virtual arc centered at the center point (P) so as to be movable along the outer peripheral surface of the cooling roll, and an arc direction position adjusting member that the holding member moves,
At least a part of both ends in the width direction of the molten resin film is brought into close contact with the surface of the cooling roll by an adhesive force directed from the nozzle at the working tip of the edge pinning device toward the center point (P) of the cooling roll. It is characterized by cooling while.

In the method for producing a resin film of the present invention, the tip of the adhesion forming means for bringing the molten resin into close contact with the surface of the cooling roll is a nozzle, and the gas flows flowing along the straight line (G) from the tip of the nozzle. It is characterized in that the resin is brought into close contact with the surface of the cooling roll .

Moreover, in the manufacturing method of the resin film of this invention, it is desirable that the gas flow which flows along a straight line (G) from the front-end | tip of the said nozzle is air.

The edge pinning device of the present invention is
A base arranged to form a predetermined gap in the cooling roll;
A width direction position adjusting member formed on the base so as to be movable in the width direction of the cooling roll;
An arc direction position adjusting member which is erected on the width direction position adjusting member and has a moving region on a concentric circle with the rotation axis center point (P) of the cooling roll;
A holding member that moves within the moving region;
The tip part coupled to the holding member has an adhesion forming means that is a nozzle,
The position of the tip is provided at a position on an extension line of a straight line (G) connecting the contact point (a) of the cooling roll to which the molten resin film adheres and the rotation axis center point (P) of the cooling roll , The tip is held movably back and forth,
The gas flow ejected from the tip of the action consisting of the nozzle at the tip of the contact force forming means causes the contact point (a) of the cooling roll to be in close contact with the molten resin film and the rotational axis center point (P) of the cooling roll. The gas flow which is on the extended line of the connecting straight line (G) and which is ejected from the nozzle at the working tip is at least one at both ends in the width direction of the molten resin film toward the rotation shaft center point (P) of the cooling roll. It is characterized in that it is formed so as to be able to impart adhesion to at least a part of both ends of the molten resin film .

In the edge pinning device of the present invention, the adhesion force forming means is preferably a perforated nozzle that sprays a gas flow onto the molten resin .

In the method for producing a resin film of the present invention, an arc direction position adjusting member having a moving region formed concentrically with the cooling roll so as to always press the molten resin toward the rotation axis center point (P) of the cooling roll. Since it is arranged and moved along this arc direction position adjusting member, and both ends in the width direction of the molten resin are pinned using an edge pinning device having a holding body for holding the adhesion forming means, be moved porous nozzle is adhesion formation means when the porous nozzle positioning is adhesion formation means, adhesion to a cooling roll from the porous nozzle or is this adhesion forming means is always a cooling roll It develops toward the rotation axis center point (P). In addition, the arc direction position adjusting member of the edge pinning device has a moving region formed concentrically with the rotational axis center point (P) of the cooling roll, and a holding member in which the adhesion force forming means is fixed in the moving region. Therefore, no matter how this holding member is moved in the moving region, the contact force applied to the surface of the cooling roll from the porous nozzle or contact force forming means is always the contact point (a ) And the rotation axis center point (P) of the cooling roll, and acts on the molten resin as an adhesion force toward the rotation axis center point (P) of the cooling roll without deviating from the extension line of the straight line (G). Therefore, the positioning of the adhesive force forming means can be easily performed without requiring special skills, and the resin film is efficiently manufactured while properly suppressing the necking generated at the end of the molten resin extruded from the die. can do.
The molten resin extruded from the die by the gas flow from the perforated nozzle which is such an adhesion force forming means adheres to the surface of the cooling roll by the adhesion force toward the rotation axis center point (P) of the cooling roll. In is easily controlled, and even if surging occurs when extruding the molten resin, fluctuations in the width of the neck in can be reduced.

In the method for producing a resin film of the present invention, by using an edge pinning device, it is possible to quickly cope with troubles during the production of the film, such as neck-in and ear shaking.

Next, the edge pinning apparatus of this invention and the manufacturing method of the resin film of this invention which uses this edge pinning apparatus are demonstrated concretely.
FIG. 1 and FIG. 3 are diagrams showing an edge pinning device having a porous nozzle that is one of the adhesion forming means used in the present invention and the manufacturing method of the present invention, a cooling roll, and the surrounding state. FIGS. 2 and 4 are views showing the relationship between an electrode and a cooling roll, which are adhesion force forming means that may be used in combination with the apparatus of the present invention that uses a nozzle as the adhesion force forming means . FIG. 5 is a diagram showing an example of a holding member that moves in a moving region formed on the holding member and the arc direction position adjusting member in the edge pinning device used in the present invention and the manufacturing method of the present invention.

  First, the edge pinning device of the present invention and the method for producing the resin film of the present invention using the edge pinning device will be described with reference to the case where the adhesion forming means is a porous nozzle. FIG. 1 and FIG. As shown, in the method for producing a resin film of the present invention, the molten resin 12 extruded from the die 10 is taken on the outer peripheral surface of the cooling roll 20 and cooled and solidified to produce a resin film 12a.

The molten resin 12 extruded from the die 10 has its both end portions entering the central portion in the width direction due to its surface tension and the like, causing a reduction in width. This is so-called neck-in. Such a neck-in always occurs as long as the resin is extruded from the die 10 in a molten state. However, in order to stabilize the neck-in width and reduce the film loss, the molten resin 12 is used for a short time. The resin film is cooled to obtain a resin film, and both end portions in the width direction of the molten resin 12 are extruded from the die 10 and brought into close contact with the cooling roll 20 to be cooled. In the present invention, for this edge pinning, for example, an edge for spraying a gas flow using a porous nozzle at both ends in the width direction of a molten resin to be necked in as shown in FIGS. 1 and 3 Use a pinning device.

  In the edge pinning device of the present invention, a base 30 and a width direction position adjusting member 31 for moving the position of the porous nozzle 50 in the width direction of the cooling roll 20 are formed. Further, the width direction position adjusting member 31 is provided with a handle 32 for moving the position of the multi-hole nozzle 50 in the width direction of the cooling roll 20. The handle 32 is connected to the handle 32 by rotating the handle 32. A rotating spiral groove (not shown) rotates. The rotating spiral groove is screwed into a spiral groove (not shown) formed on the moving base 33 on which the arc direction position adjusting member 40 is erected, and the rotating spiral groove is formed by rotating the handle 32. By rotating, the moving base 33 on which the arc direction position adjusting member 40 is erected can be moved in the width direction of the cooling roll 20.

  An arc direction position adjusting member 40 is erected on the moving base 33, and the arc direction position adjusting member 40 is formed with a moving region 42 for the holding member 45 to move. The moving area 42 is a space formed between the holding body guide members 43A and 43B, and the moving area 42 is formed in an arc shape concentric with the rotational axis center point (P) of the cooling roll 20. ing. That is, since the holding body guide members 43A and 43B are formed so as to be concentrically curved with the cooling roll 20, the movement consideration area 42 formed between the holding body guide members 43A and 43B is also the same. It becomes a curve having a concentric curve with the cooling roll 20. A spiral groove is usually formed on the opposing edges 44A and 44B of the holding body guide members 43A and 43B so as to be screwed with a moving gear 46 provided on the holding member 45.

As shown in FIG. 1 and FIG. 5, the holding member 45 disposed in the moving region 42 is a housing 47 and a movement that is pivotally supported with respect to the housing 47 inside the housing 47. A driving gear 49 for rotating the moving gear 46 by rotating a handle 48 for rotating the moving gear 46, and support gears 51 a and 51 b for holding the moving gear 46. is doing. The moving gear 46 is formed so as to be able to move the holding member 45 in the moving region 42 by screwing with a spiral groove formed on the edges 44A and 44B of the holding body guide members 43A and 43B forming the moving region 42. Yes. That is, the driving gear 49 is rotated by rotating the handle 48, and the moving gear 46 is rotated by this rotation, and the holding member 45 can be moved to an arbitrary position in the moving region 42. The housing 47 constituting the holding member 45 is formed with a stopper member 56 for fixing the holding member 45 to the arcuate position adjusting member 40 after the holding member 45 is moved. The housing 47 of the holding member 45 is formed so as to fix and hold the conduit 52 having the porous nozzle 50 bonded to the tip. The conduit 52 is provided with a forward / backward moving member 53 so that the position of the multi- hole nozzle 50 can be moved back and forth toward the cooling roll 20. The forward / backward moving member 53 is usually composed of an outer tube 53a and an inner tube 53b inserted into the outer tube 53a. The outer tube 53a is fixed to the casing 47, and the inner tube 53b. Can be moved back and forth with respect to the cooling roll 20 of the porous nozzle 50 . The inner tube 53b can be fixed to the outer tube 53b by a seal fixing member 53c provided at the tip of the outer tube 53a.

Further, a gas introducing flexible tube 54 is joined to the other end portion where the conduit 52 of the front-and-rear moving member 53 is not disposed. The gas introducing flexible tube 53 includes a barometer 55 and a gas flow rate adjustment. The valve 57 is connected to a compressor (not shown) .

  As shown in FIG. 3, the multi-hole nozzle 50 provided at the tip of the conduit 52 fixed to the holding member 45 has a large number of jets 60. As shown in FIG. The gas ejected from the large number of ejection ports 60 is arranged so as to go to the rotation shaft center point (P) of the cooling roll 20. That is, the porous nozzle 50 is disposed so that the gas flow 61 ejected from the jet nozzle 60 formed in the porous nozzle 50 is directed to the rotation shaft center point (P) of the cooling roll 20. The gas flow 61 is sprayed toward the contact point (a) of the molten resin 12 on the surface of the cooling roll 20. A perforated nozzle 50 is disposed on an extension line of the straight line G connecting the contact point (a) of the molten resin 12 on the surface of the cooling roll 20 and the rotational axis center point (P) of the cooling roll 20. By forming the gas flow 61 along the extension line, the gas flow 61 can be sprayed at right angles to the tangential line 62 imaginary on the surface of the cooling roll at the contact point (a). The surface of the cooling roll 20 can be brought into close contact with the rotation axis center point (P) of the cooling roll 20. Therefore, the molten resin 12 that has been extruded from the die 10 and has contacted the cooling roll 20 while being necked in somewhat, immediately after contacting the cooling roll 20, is rotated along the straight line G of the cooling roll 20 at the contact point (a). The gas flow 61 toward the point (P) is pressed against the surface of the cooling roll 20 to be cooled, and neck-in due to the surface tension of the molten resin 12 is stopped. That is, the multi-hole nozzle 50 is formed with a large number of jet ports 60 and forms a gas flow zone composed of a gas flow 61 from the large number of jet ports 60 toward the rotational axis center point (P) of the cooling roll 20. Then, the molten resin 12 is pressed against the surface of the cooling roll 20 with the width of the gas flow band from both side ends of the molten resin, and comes into close contact. Since the neck-in occurs at both ends of the molten resin, the both ends are melted at both ends by being in close contact with the surface of the cooling roll 20 at the contact point (a) by the gas flow zone. Resin neck-in can be stopped. Moreover, the gas flow zone is a set of gas flows 61 directed toward the rotational axis center point (P) of the cooling roll 20, and the gas flow 61 is tangent 62 imaginary at the spraying point (a) of the gas flow of the cooling roll 20. Therefore, the molten resin 12 can be pressed against the surface of the cooling roll 20 from directly above, and neck-in can be prevented more efficiently.

  The gas flow 61 formed here presses the molten resin 12 against the surface of the cooling roll 20 as described above, and is usually an air flow, but is not suitable for the molten resin 12 such as nitrogen or argon. An active gas can also be used.

  Such a gas flow 61 is to press both side ends of the molten resin 12 against the surface of the cooling roll 20 to be brought into close contact with each other, and usually has a pressure of 0.4 to 1.2 MPa, preferably 0.8 to 1.0 MPa. Can be formed using an adjusted gas.

  Further, in the edge pinning device of the present invention, it is preferable to dispose a three-dimensional movable pipe 70 and to spray the gas flow 71 toward the contact point (b) on the molten resin 12 outside the nozzle 60. The three-dimensional movable pipe 70 is also preferably arranged so that the gas flow 71 is directed to the rotation axis center point (P) of the cooling roll 20.

The three-dimensional movable pipe 70 is fixed to the holding member 45 in the same manner as the nozzle 60, and the gas flow from the three-dimensional movable pipe 70 is always directed toward the rotational axis center point (P) of the cooling roll 20. And is sprayed at right angles to the virtual tangent line 72 at the spray point of the gas flow 71. Therefore, both ends of the molten resin 12 on the surface of the cooling roll 20 are pressed against the cooling roll 20 to be cooled. The gas flow 71 ejected from the three-dimensional movable pipe 70 is usually an air flow, but a gas inert to the molten resin 12 such as nitrogen or argon can also be used. Such a gas flow 71 from the three-dimensional movable pipe 70 is outside the perforated nozzle 50 and presses both end portions of the molten resin 12 against the surface of the cooling roll 20, and is usually 0. It can be formed using a gas whose pressure is adjusted to 1 to 0.4 MPa, preferably 0.2 to 0.3 MPa. The pressure applied by the gas flow 71 from the three-dimensional movable pipe 70 is preferably lower than the pressure applied by the gas flow 61 from the nozzle 50.

  The three-dimensional movable pipe 70 is also fixed to the holding member 45 in the same manner as the multi-hole nozzle 50, and moves together with the multi-hole nozzle 50 by moving the nozzle holding member 45. The relative positional relationship is constant. Further, since the holding member 45 moves in the moving region 42 on the concentric circle of the cooling roll 20, the three-dimensional movable pipe 70 fixed to the holding member 45 is connected to the rotation axis center point (P) of the cooling roll 20. It always moves on a virtual arc 79 virtually concentric to the rotation roll center point (P) of the cooling roll. Therefore, the gas flow 61 and the gas flow 71 fixed to the holding member 45 and ejected from the three-dimensional movable pipe 70 are always formed toward the rotational axis center point (P) of the cooling roll 20.

In the method for producing a resin film of the present invention, both ends in the width direction of the molten resin 12 can be pinned by the gas flow 61 ejected from the porous nozzle 50 as described above .
Further, the nipping device in the present invention uses a gas flow ejected from the nozzle, and in addition, as shown in FIGS. 2 and 4, the molten resin 12 is electrostatically brought into close contact with the cooling roll 20. Can also be used together. That is, 75.75 is arranged as an adhesion forming means in the vicinity of both end portions of the molten resin 12 extruded from the die 10 and in contact with the cooling roll 20, and a voltage is applied between the cooling roll 20 and each of them. Thus, the molten resin 12 can be charged and electrostatically brought into close contact with the cooling roll 20 electrostatically. The applied voltage at this time is usually 10 to 50 kV, preferably 10 to 20 KV. Thus, the neck-in can be further reduced by bringing the molten resin 12 into close contact with the cooling roll 20 electrically. As an apparatus for bringing the molten resin 12 into close contact with the cooling roll 20, for example, a PST-2005N type charging apparatus manufactured by Kasuga Electric Co., Ltd. can be cited.

That is, as shown in FIG. 2 and FIG. 4, the edge pinning device using the gas flow described above and the edge pinning device in which the electrode 75 that can be used in combination with the edge pinning device is further used. By applying a voltage of usually 10 to 50 KV, preferably 10 to 20 KV in between, the molten resin 12 is charged and adheres to the surface of the cooling roll 12. Here, 75 is arranged on the extended line of the straight line G connecting the contact point (a) of the molten resin 12 in the cooling roll 20 and the rotational axis center point (P) of the cooling roll, whereby the width of the molten resin 12 is increased. The molten resin 12 can be brought into close contact with the cooling drum while pinning both ends. This 75 is fixed to the holding body 45 in the same manner as the porous nozzle 50 described above, and this 75 is joined to the wiring 77 through the conduit 52, and this wiring 77 is joined to the controller 78. And a cooling roll 20 are connected so that a desired voltage can be applied.

Furthermore, in the manufacturing method of the resin film of the present invention using the edge pinning apparatus of the present invention as described above, the molten resin 12 extruded from the die 10 is surely wound around the cooling roll 20, and the resin film 12a obtained is In order to improve surface glossiness and transparency, for example, as shown in FIG. 6, a resin film can be produced using a resin film suction chamber device 80 in combination. FIG. 6 is a view showing the vicinity of a die and a cooling roll provided with a suction chamber device that can be used in the present invention.

The suction chamber apparatus that can be used in the present invention is not particularly limited, and a conventionally used suction chamber apparatus can be used. In the present invention, for example, a suction chamber apparatus 80 as shown in FIG. By using it, the molten resin 12 can be reliably wound around the cooling roll 20, and air is not entrained when the molten resin 12 is wound around the cooling roll 20, and is contained in the molten resin 12. It is possible to prevent the cooling roll 20 from being contaminated by the low-boiling substance, so that the gloss of the surface is not impaired, and further, the cooling roll 20 is prevented from being contaminated, so that the transparency of the resin film 12a is excellent. Become.

A suction chamber device 80 that can be preferably used in the present invention includes a suction chamber main body 81, a lower surface of the die 10, and a U-shape adjacent to the lower surface of the die 10 of the suction chamber main body 81 as shown in FIG. The U-shaped seal packing 86 interposed between the edges of the mold opening, the suction port manifold 89, and the plurality of suction ports 84 and the suction port manifold 89 provided in the suction chamber body 81 are connected. A vacuum pipe hose 88 and a suction blower 95 connected to the suction outlet manifold 89.

  In this suction chamber device 80, the suction chamber body 81 is arranged on the upstream side in the moving direction of the cooling surface by the rotation of the cooling roll 20, and the upper plate 81a from which the side close to the die 10 is removed, the side wall 81b, 81c, the back plate 81d, and the plurality of suction ports 84 are integrated, and have a half-box shape in which the lower side facing the cooling roll 20 is opened. A receiving plate 82 and a perforated plate 83 are provided on the back plate 81d and the side walls 81b and 81c. A portion surrounded by the lower surface of the die 10, the circumferential surface of the cooling roll 20, and the tips of the side walls 81b and 81c forms a suction space having a suction port 90 and a suction air passage. The lower surface of the die 10 is exposed to this suction space. A U-shaped seal packing 86 is formed by the seal packing 85 at the edge of the upper plate 81a of the suction chamber body 81 and the seal packing at the upper edges of the side walls 81b and 81c. The lower edges of the side walls 81b and 81c and the back plate 81d are provided with cooling rolls so that when the suction chamber body 81 is placed at a predetermined position and sucked, excessive air does not enter the suction chamber body 81. It is adjusted to a position away from 20 by a slight distance (usually 1 to 2 mm). Further, on both sides of the die 10, rectifying guide plates 87 for preventing stagnation of the sucked air are arranged.

When the molten resin 12 is extruded from the die 10 into a sheet shape and wound around the cooling roll 20 that rotates at a predetermined peripheral speed, the molten resin 12 and the cooling roll 20 In order to prevent air from being caught in between, the air in this portion is sucked from the suction port 90. The air sucked in this way is sucked out by the suction blower 95 from the suction port 84 of the casting device 80 through the hose 88 and the suction port manifold 89.
The air sucked in this way contains gases of volatile components such as low molecular weight components and additives contained in the molten resin 12, and the aggregate of such components becomes a contamination source on the surface of the cooling roll 20. . However, in the suction chamber device 80 shown in FIG. 6, there is no upper plate portion of the housing like the suction chamber body 81, and the lower surface of the die 10 sealed by the seal packings 85 and 86 is formed in the suction chamber body 81. Since the die 10 is heated to melt the resin, there is no possibility that the gas of the volatile component condenses in this portion. Volatile components and low molecular weight components contained in the sucked air are likely to condense in the vicinity of the upper plate 81a on the back plate 81d side of the suction chamber body 81. However, the condensed components are received by the tray 82, so that they are cooled. The surface of the roll 20 is not contaminated. Such a suction chamber apparatus is described in JP-A-2002-355882.

The resin used in the production method of the present invention using the edge pinning apparatus of the present invention is not particularly limited as long as it is a thermoplastic resin that can be formed into a film. Specific examples of such thermoplastic resins include homo- or copolymers of α-olefins such as ethylene, propylene, butene-1, hexene-1, 4-methyl pentene-1 and octene-1, low pressure method low density Polyethylene, linear low density polyethylene (so-called LLDPE), high density polyethylene, polypropylene, polypropylene random copolymer, polybutene, poly-4-methyl pentene-1, low crystalline or amorphous ethylene / propylene random copolymer , An ethylene / butene-1 random copolymer, a polyolefin such as propylene / butene-1 random copolymer, or a composition of two or more, ethylene / vinyl acetate copolymer (EVA) or EV
A composition of A and polyolefin, polyester such as polyethylene phthalate, polybutylene phthalate and polyethylene naphthalate, polyamide inorganic compound (B) such as nylon 6, nylon 66 and polymetaxylene adipamide, and thermoplastic resin such as polystyrene It can be illustrated.

  Among these thermoplastic resins, the method for producing the resin film of the present invention is preferably polyolefin, more preferably high pressure method low density polyethylene or linear low density polyethylene, particularly preferably linear low density polyethylene resin film. Suitable for manufacturing.

In the present invention, for example, as a high-pressure method low density polyethylene, the density is usually 0.910 to 0.935 g / cm ³ , preferably 0.920 to 0.935 g / cm ³ , MFR (ASTM D1238; load 2160 g). , A temperature of 190 ° C.) is usually 1 to 30 g / 10 minutes, preferably 1 to 10 g / 10 minutes, and a homopolymer of ethylene polymerized under a high pressure, or other α-olefin of 5% by weight or less, or vinyl acetate Copolymers with vinyl compounds such as can be used.

The linear low density polyethylene has a density of usually 0.905 to 0.940 g / cm ³ , preferably 0.910 to 0.935 g / cm ³ , MFR (ASTM D1238;
A load of 2160 g and a temperature of 190 ° C. is usually 0.5 to 20 g / 10 minutes, preferably 1 to 10 g / 10 minutes of ethylene and an α-olefin having 3 to 10 carbon atoms (eg, propylene, butene-1, Random copolymers with heptene-1, hexene-1, octene-1, 4-methyl-pentene-1). Such a linear low density polyethylene has a molecular weight distribution (weight average molecular weight: Mw, number average molecular weight: Mn, ratio expressed by Mw / Mn) is usually 1.5 to 4.0, preferably 1. In the range of .8 to 3.5. In the present invention, Mw / Mn is a value measured by gel permeation chromatography (GPC).

  The linear low density polyethylene preferably used in the present invention has one or more sharp peaks obtained from an endothermic curve measured using a differential scanning calorimeter (DSC) under a temperature rising rate of 10 ° C./min. There can be used a linear low density polyethylene having a peak maximum temperature, that is, a melting point of usually 70 to 130 ° C, preferably 80 to 120 ° C.

  The linear low density polyethylene as described above can be prepared by a conventionally known production method using a single site catalyst. For example, linear low density polyethylene can be prepared using a catalyst containing a metallocene compound of a transition metal. The catalyst containing the metallocene compound is preferably formed from (a) a transition metal metallocene compound, (b) an organoaluminum oxy compound, and (c) a carrier, and if necessary, these components and (D) It may be formed from an organoaluminum compound and / or an organoboron compound.

  An olefin polymerization catalyst containing such a metallocene compound and a method for preparing linear low density polyethylene using such a catalyst are described in, for example, JP-A-8-269270.

The resin as described above is heated to extrude the molten resin 12 having a desired thickness from the die 10. The thickness of the extruded molten resin is usually 10 to 200 μm, preferably 20 to 150 μm. The molten resin 12 thus extruded from the die 10 is taken up by the cooling roll 20 and cooled to become the resin film 12a. The molten resin 12 is in contact with the cooling roll 20 from the die 10 and before the molten resin is cooled. In this case, a so-called neck-in that narrows in the width direction occurs due to the surface tension of the molten resin. In order to reduce this neck-in, it is necessary to cool the molten resin 12 as early as possible. For this reason, the molten resin 12 is cooled by being brought into close contact with the surface of the cooling roll 20 immediately after being extruded from the die 10. On the surface of the roll 20, the molten resin 12 on the surface of the cooling roll 20 is removed from the porous nozzle 50 and, if necessary, the three-dimensional movable pipe 70, in order to prevent both ends of the molten resin 12 in the width direction from shrinking inward in the width direction. 12 is sprayed with gas flows 61 and 71 directed toward the rotational axis center point (P) of the cooling roll 20 to cool the melted resin 12 at an early stage while suppressing shrinkage, or in combination with them. A voltage is applied to the possible electrode 75 to charge the molten resin 12 and bring it into close contact with the cooling roll 12. Further, the suction chamber device 80 may be disposed on the side opposite to the surface of the molten resin 12 on which the electrode 75 or the porous nozzle 50 and, if necessary, the three-dimensional movable pipe 70 are disposed. The suction chamber device 80 is originally intended to remove low molecular weight components and volatile components contained in the molten resin, but sucks air between the molten resin 12 and the suction chamber device 80. Therefore, the back surface side of the extruded molten resin 12 (the surface in contact with the cooling roll 20) is somewhat depressurized, and the extruded molten resin 12 becomes easier to adhere to the cooling roll 20 sooner.

  In this way, at both ends in the width direction of the molten resin 12 in contact with the surface of the cooling roll 20, the multi-hole nozzle 50 and, if necessary, the three-dimensional movable nozzle 70, toward the rotation axis center point (P) of the cooling roll 20. Since the gas flow is sprayed and both end portions of the molten resin 12 are pressed against and brought into close contact with the surface of the cooling roll 20, occurrence of neck-in at both end portions in the width direction of the molten resin 12 can be reduced.

In addition, the present invention uses a nozzle as the adhesion forming means. However, even when an electrode 75 that can be used in combination with the nozzle 75 is disposed and a voltage is applied, the rotational axis center point of the cooling roll 20 is similarly applied. Since the molten resin 12 comes into close contact with the surface of the cooling roll 20 due to the adhesive force toward (P), occurrence of neck-in at both ends in the width direction of the molten resin 12 can be reduced.

Further, the multi-hole nozzle 50 used as described above and the three-dimensional movable pipe 70 used as necessary, or the electrode 75 that can be used in combination therewith, are directed to the rotation axis center point (P) of the cooling roll 20. It is fixed to the holding member 45 in a state in which the direction of the tip of the adhesion force forming means is determined in advance so as to form a gas flow or an adhesion force, and the holding member 45 is concentrically with the cooling roll 20. It moves in the formed movement area 42. Therefore, since the movement of the holding member 45 in the circumferential direction of the cooling roll 20 is limited to be concentric with the rotation axis center point (P) of the cooling roll 20, the porous nozzle 50 fixed to the holding member 45 and the three-dimensional movable The tip portion of the adhesive force forming means, which is the pipe 70 or the electrode 75 that can be used in combination therewith, is always virtually concentric with the rotational axis center point (P) of the cooling roll along the outer peripheral surface of the cooling roll 20. Move on the virtual arc 79. Moreover, the adhesion force that is manifested by applying a voltage to the gas flow 61, 71 ejected from the multi-hole nozzle 50 and the three-dimensional movable pipe 70, or to the electrode 75 that can be used in combination with the gas flow 61, 71 is always the rotational axis of the cooling roll. It goes to the center point (P). Movement position in the width direction of the cooling roll 20 of the multi-hole nozzle 50 and the three-dimensional movable pipe 70 from the prior art, can be set relatively easily by using a width direction position adjusting member 31, the porous nozzle 50 and the three-dimensional It has been said that a high level of skill is required to set the movement position of the movable pipe 70 or the circumferential direction of the cooling roll 20 of the electrode 75 that can be used in combination therewith. However, by using the edge pinning device of the present invention, the position of the perforated nozzle 50 and the cooling roll 20 of the three-dimensional movable pipe 70 , or the position of the electrode 75 that can be used in combination with these , is optimal for preventing neck-in. It can always be given to the molten resin 12 as an adhesion force toward the rotational axis center point (P) of the cooling roll 20.

In particular, by using the edge pinning device of the present invention, it becomes possible to quickly respond to a neck-in that occurs at the start of film production or when trouble occurs and stabilize the amount of neck-in. . In addition, according to the method of the present invention, it is possible to quickly cope with ear shaking that occurs during the production of a resin film.

  The resin film 12a obtained by using the edge pinning device of the present invention has a stable neck-in amount and can also reduce ear shaking. The production method of the present invention can be applied to the production of a film using the above-described resin. This resin film may be an unstretched film, or may be a uniaxially stretched film or a raw film of a biaxially stretched film.

In the present invention, the perforated nozzle 50 and the electrode 75 do not particularly exclude the combined use in the present invention, and the combined use thereof is also possible. That is, a nozzle 50 such as a perforated nozzle is used as the adhesion force forming means, and a voltage application device that forms a potential difference with the cooling roll to electrostatically adhere the molten resin to the cooling roll is also used. Is possible.
[Example]

EXAMPLES Next, the present invention will be described in more detail with reference to examples of the present invention, but the present invention is not limited thereto.
[Example 1]
Linear low density polyethylene (density: 0.920 g / cm ³ , MFR: 4 g / 10 min, DS
C melting point: After melting the main peak 118 ° C. (having sub-peaks at 105 ° C. and 122 ° C.), the molten resin 12 was extruded from the die 10 onto the cooling roll 20 to produce a linear low density polyethylene film having a thickness of 40 μm. .

  An edge pinning device having a width direction nozzle position adjusting member and an arc direction position adjusting member as shown in FIGS. 1, 3 and 5 is disposed downstream of the molten resin 12 in the flow direction. As shown in FIG. 3, the gas flows 61 and 71 formed by the multi-hole nozzle 50 and the three-dimensional movable pipe 70 fixed to the holding member 45 of the pinning device are at the rotational axis center point (P) of the cooling roll 20. It is arranged to face. The handle 32 of the edge pinning device is rotated to determine the positions of the porous nozzle 50 and the three-dimensional movable pipe 70 in the width direction, and then the handle 48 formed on the nozzle holding member 45 is rotated to rotate the porous nozzle 50. And the three-dimensional movable pipe 70 was positioned in the circumferential direction of the cooling roll 20. The gas flow rate adjustment valves of the multi-hole nozzle 50 and the three-dimensional movable pipe 70 are adjusted (applied pressure; 1.0 MPa), the air flow rate from the multi-hole nozzle 50 is 2.8 liters / second, and the air from the three-dimensional movable pipe 70 The flow rate was adjusted to 0.8 liter / second. The porous nozzle 50 is formed with eleven ejection holes 60. The porous nozzle 50 is installed so that the tip thereof is positioned at 5.0 mm from the cooling roll 20, and the three-dimensional movable pipe 70 is provided. Was placed so that its tip was 10 mm from the cooling roll 20.

  Further, a suction chamber device 80 shown in FIG. 6 is arranged on the back surface side of the molten resin 12 extruded as described above, and the blower 95 is driven to drive the molten resin 12 and the suction chamber device 80. The air in between was sucked in at an amount of 1 kiloliter / minute.

Each apparatus was arranged as described above, and a linear low density polyethylene film having a thickness of 50 μm was continuously produced for 4 days.
The production of the film was stable throughout, and the amount of neck-in could be controlled to 3.5% or less of the whole produced film. In addition, the neck-in sometimes increased due to surging during film production, but by operating the handle 48 formed on the nozzle holding member 45, it was possible to achieve a stable state in a very short time.
[Reference example]
Instead of the edge pinning device used in the first embodiment, an edge pinning device having a width direction position adjusting member and a circumferential direction position adjusting member at the tip (charging pinning) as shown in FIG. 2, FIG. 4 and FIG. Was used to produce a linear low density polyethylene film having a thickness of 50 μm.

  At that time, the electrode (tip portion of the charging pinning) was disposed at a position of 5.0 mm from the cooling roll, and a voltage of 12 KV was applied between the cooling roll and the electrode. Similarly to Example 1, a suction chamber is disposed on the back side of the molten resin to be extruded, and the blower is driven to reduce the air between the molten resin and the suction chamber to 1 kiloliter / minute. Aspirated by volume.

  The production of the film was stable throughout, and the amount of neck-in could be controlled to 3.5% or less of the whole produced film. Further, the neck-in sometimes increased due to surging during film production, but it was possible to obtain a stable state in a very short time by operating the handle formed on the nozzle holding member.

  The edge pinning apparatus of the present invention is not limited to the production of a single layer film but can be suitably used for the production of a film produced using a T-die, including the production of a laminated film or an extruded laminated film. Moreover, the edge pinning apparatus of this invention can be used not only for manufacture of an unstretched (non-stretched) film but for manufacture of a stretched film.

  In addition, the method for producing a resin film of the present invention using the edge pinning apparatus of the present invention is excellent in high-speed stability, especially in the production of an unstretched (non-stretched) film, and the quality of the obtained resin film is also stable. Therefore, the obtained resin film can be used for various applications including packaging films.

FIG. 1 is a view showing an example of an edge pinning device of the present invention having a porous nozzle and a method for producing a resin film of the present invention using the edge pinning device, and showing a state of the porous nozzle and its surroundings. . FIG. 2 shows an example of an edge pinning device having an electrode that can be used in combination with the edge pinning device of the present invention and a method for producing a resin film of the present invention using the edge pinning device. It is a figure which shows a state. FIG. 3 is an enlarged view showing an example of an edge pinning device having a porous nozzle, which is an example of the edge pinning device of the present invention, and a porous nozzle that is a working tip in an adhesion forming means of the edge pinning device. FIG. 4 is an enlarged view of an example of an edge pinning device having an electrode that can be used in combination with the edge pinning device of the present invention, and an example of a portion that is a working tip in the adhesion forming means of the edge pinning device. FIG. 5 is a view showing an example of a holding member for moving in a moving region formed in an arc shape of an arc direction position adjusting member in an edge pinning device having a porous nozzle as an example of the edge pinning device of the present invention. is there. FIG. 6 is a diagram showing an example of a suction chamber device arranged in the vicinity of a die and a cooling roll having an edge pinning device having a porous nozzle as an example of the edge pinning device of the present invention. FIG. 7 is a diagram showing a conventional edge pinning device.

DESCRIPTION OF SYMBOLS 10 ... Die 12 ... Molten resin 12a ... Resin film 20 ... Cooling roll 30 ... Base 31 ... Width direction position adjustment member 32 ... Handle 33 ... Moving base 40: Arc direction position adjusting member 42: Moving spaces 43A, 43B ... Holding body guide members 44A, 44B ... Edge 45 ... Holding member 46 ... Moving gear 47 ... Housing 48 ... handle 49 ... driving gear 50 ... perforated nozzles 51a, 51b ... support gear 52 ... conduit 53 ... forward / backward moving member 53a ... outer tube 53b ... inside Pipe 53c ... Seal fixing member 54 ... Flexible tube 55 for introducing gas ... Barometer 56 ... Stopper member 57 ... Gas flow rate adjusting valve 60 ... Jet port 61 ... Gas flow 62 ... Virtual tangent line 70 ... 3D Moving pipe 71 ... Gas flow 75 ... Electrode 77 ... Electrical wiring 78 ... Controller 79 ... Virtual arc 80 concentric with the rotation axis center point (P) ... Casting device 81 ... · Suction chamber body 81a · · · upper plate 81b, 81c · · · side wall 81d · · · back plate 84 · · · suction port 85 · · · seal packing 86 · · · seal packing 87 · · · guide plate 88 · .... Hose 89 ... Suction outlet manifold 90 ... Suction port 95 ... Suction blower 101 ... Base 103 ... Cooling roll 105 ... Nozzle position adjusting device 107 ... Three-dimensional movable pipe 109 ... 3D movable porous nozzle
more than

Claims (10)

When producing the resin film by taking the molten resin extruded from the die on the outer peripheral surface of the cooling roll and cooling and solidifying it,
Extension of a straight line (G) connecting the contact point (a) of the cooling roll to which the molten resin adheres and the rotational axis center point (P) of the cooling roll at a position where the tip is a nozzle. An adhesive force is provided along the straight line (G) from the tip of the nozzle so that the molten resin film is brought into close contact with the surface of the cooling roll by the gas flow flowing along the straight line (G) from the tip of the nozzle. And holding the nozzle at the tip of the adhesion force forming means so as to be movable back and forth along the straight line (G) toward the rotational axis center point (P) of the cooling roll. Using an edge pinning device having a holding member that holds a virtual arc centered at the center point (P) so as to be movable along the outer peripheral surface of the cooling roll, and an arc direction position adjusting member that the holding member moves,
At least a part of both ends in the width direction of the film made of the molten resin is brought into close contact with the surface of the cooling roll by an adhesive force directed from the nozzle at the working tip of the edge pinning device to the rotation roller center point (P). A method for producing a resin film, characterized by cooling while cooling. The gas blown toward the outer peripheral surface of the cooling roll toward the center point (P) of the rotation axis of the cooling roll is a gas flow ejected from the perforated nozzle, and the gas flow moves back and forth in the vicinity of the outer peripheral surface of the cooling roll. A perforated nozzle provided in a possible manner, a gas introduction pipe for sending gas to the perforated nozzle, a holding member for holding the gas introduction pipe, and the rotational axis center of the cooling roll along the outer peripheral surface of the cooling roll. An arc direction position adjustment member having an arc-shaped moving region formed concentrically with the point (P) as a center point, and a width direction position adjustment that enables the arc direction position adjustment member to move in the width direction of the cooling roll 2. The method for producing a resin film according to claim 1, wherein the gas flow is ejected from a porous nozzle of an edge pinning device having a member. The edge pinning device has a large number of nozzles for ejecting gas, and the gas is substantially perpendicular to the virtual tangent at the gas spray point (b) outside the porous nozzle in the width direction of the formed resin film. A method for producing a resin film according to claim 1 or 2 , wherein a three-dimensional movable gas jet port for spraying is formed. The method for producing a resin film according to any one of claims 1 to 3 , wherein the gas is air. The method for producing a resin film according to any one of claims 1 to 4 , wherein the resin is a polyolefin. 6. The method for producing a resin film according to claim 5 , wherein the polyolefin is linear low density polyethylene. A base arranged to form a predetermined gap in the cooling roll;
A width direction position adjusting member formed on the base so as to be movable in the width direction of the cooling roll;
An arc direction position adjusting member which is erected on the width direction position adjusting member and has a moving region on a concentric circle with the rotation axis center point (P) of the cooling roll;
A holding member that moves within the moving region;
The tip portion fixed to the holding member has an adhesion forming means that is a nozzle,
The position of the tip is provided at a position on an extension line of a straight line (G) connecting the contact point (a) of the cooling roll to which the molten resin is in close contact and the rotation shaft center point (P) of the cooling roll. The part is held movably back and forth,
The gas flow ejected from the working tip composed of the nozzle at the tip of the contact force forming means connects the contact point (a) of the cooling roll where the molten resin is in close contact with the rotational axis center point (P) of the cooling roll. The gas flow which is on the extension line of the straight line (G) and is ejected from the nozzle at the working tip is at least one of both ends in the width direction of the film of the molten resin toward the rotation axis center point (P) of the cooling roll. An edge pinning device characterized by being formed so as to be sprayed onto a portion so as to be able to impart adhesion to at least a part of both ends of the molten resin film . In the edge pinning device, the width direction position adjustment member, the holding member, the arc direction position adjustment member, and the adhesion force forming means are independently arranged so that both ends of the molten resin in the width direction are in close contact with the cooling roll. The edge pinning device according to claim 7, wherein the edge pinning device is provided. The adhesion force forming means has a porous nozzle that blows a gas flow onto the molten resin, and gas is formed at a substantially right angle to the virtual tangent at the gas blowing point outside the width direction of the resin film in which the porous nozzle is formed. The three-dimensional movable gas jet outlet is held by a holding member in the same manner as the perforated nozzle, along the arc direction position adjusting member, and along the straight line (G). 8. The edge pinning device according to claim 7 , wherein the holding member is moved so as to be movable back and forth so that gas can be sprayed substantially perpendicular to the virtual tangent of the cooling roll. . The edge pinning device according to any one of claims 7 to 9, wherein the edge pinning device is provided with a suction chamber device.

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