JP4882826B2 - Film production method - Google Patents

Description

  The present invention relates to a method for producing a film.

As films used for packaging foods, pharmaceuticals, industrial products and the like, films made of synthetic resins such as polyethylene resins and polypropylene resins are often used. These films are required to have blocking resistance and slipperiness in order to improve workability when forming a film or packaging an object to be packaged.
As one method for producing a film made of a synthetic resin, a T-die is obtained by melt-extruding a resin from a T-die into a film shape and bringing the melt-extruded film-like resin into close contact with the roll surface of a cooling roll and cooling it. Film forming methods are known. In this T-die film molding method, an anti-blocking agent is usually blended with the resin in order to improve blocking resistance and slipperiness, but the molten resin blended with the anti-blocking agent is adhered to the roll surface of the cooling roll. The effect of blending the anti-blocking agent may not be sufficient.
Therefore, the film after molding is coated with a fine powder such as starch, an anti-blocking agent is blended with low-density polyethylene, and the thickness of the layer made of the low-density polyethylene is made thinner than the average particle size of the anti-blocking agent. To form a T-die film (see Patent Document 1), and to form a T-die film by blending a surface-hydrophobized anti-blocking agent into low-density polyethylene (see Patent Document 2). It has been proposed as a method for improving blocking resistance and slipperiness.

JP 11-179778 A JP 2002-225197 A

However, in the method in which a fine powder such as starch is applied to the film, the fine powder is detached from the film, so that the fine powder adheres to the package or the film is poorly sealed. Moreover, the method of blending the anti-blocking agent with the resin is not always satisfactory in terms of blocking resistance and slipperiness.
Under such circumstances, the problem to be solved by the present invention is a method for producing a T-die film, which provides a method for producing a film excellent in blocking resistance, slipperiness and anti-blocking agent desorption resistance. There is to do.

The present invention includes a step of melt-extruding a resin from a T-die into a film, a step of spraying an anti-blocking agent on the roll surface of a cooling roll at an area average spray amount of 0.5 to 3 g / m ² , And a step of pressure-bonding the extruded film-like molten resin to the roll surface of a cooling roll sprayed with a powder of an anti-blocking agent.

  According to the present invention, it is possible to provide a method for producing a T-die film, which is excellent in blocking resistance, slipperiness and anti-blocking agent desorption resistance.

  The method for producing a film of the present invention includes a step of melt-extruding a resin from a T die into a film.

  Examples of the resin used in the present invention include polyolefin resin, polyamide resin, polyester resin, ethylene-vinyl alcohol copolymer, ionomer resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyimide resin, etc. The one that can be manufactured is used.

  As said polyolefin-type resin, the polymer which contains 50 weight% or more of 1 type, or 2 or more types of monomer units based on C2-C10 olefins, such as ethylene, propylene, 1-butene, and 1-hexene And a polyethylene resin which is a polymer containing 50% by weight or more of monomer units based on ethylene, a polypropylene resin which is a polymer containing 50% by weight or more of monomer units based on propylene, and the like. .

  Examples of the polyethylene resin include ethylene homopolymer, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, and ethylene-1. Ethylene-α-olefin copolymers such as butene-1-hexene copolymer; ethylene-vinyl ester copolymers such as ethylene-vinyl acetate copolymer; ethylene-methyl acrylate copolymer, ethylene-acrylic acid Examples include ethyl copolymers, ethylene-butyl acrylate copolymers, ethylene-methyl methacrylate copolymers, ethylene-unsaturated carboxylic acid ester copolymers such as ethylene-ethyl methacrylate copolymers, These are used alone or in combination of two or more. These polyethylene resins are produced by a known method.

  Examples of the polypropylene resin include propylene homopolymer, propylene-ethylene copolymer, propylene-1-butene copolymer, propylene-1-hexene copolymer, propylene-ethylene-1-butene copolymer, propylene. -Ethylene-1-hexene copolymer, etc. are mentioned, These are used 1 type or in combination of 2 or more types. Further, these polypropylene resins are produced by a known method.

  The polyolefin-based resin is preferably a polyethylene-based resin, and the content of the monomer unit based on ethylene in the polyethylene-based resin is 100% by weight of the polyethylene-based resin, preferably 70% by weight or more. Yes, more preferably 80% by weight or more, still more preferably 90% by weight or more.

  As the melt flow rate of the polyolefin resin, in the case of a polyethylene resin, the melt flow rate measured under the conditions of a load of 21.18 N and a temperature of 190 ° C. according to the method defined in JIS K7210-1995 is preferably 1 to 100 g / 10 min, more preferably 1.5-50 g / 10 min. In the case of polypropylene resin, measured under conditions of a load of 21.18 N and a temperature of 230 ° C. according to the method defined in JIS K7210-1995. The melt flow rate is preferably 1 to 100 g / 10 minutes, more preferably 1.5 to 50 g / 10 minutes.

  A known additive such as an antioxidant, a neutralizing agent, an antistatic agent, an antifogging agent, or a lubricant may be blended with the resin, if necessary, and other resins may be blended.

  When the resin is melt-extruded, it may be melt-extruded in a single layer, or may be melt-extruded in multiple layers such as co-extrusion.

  The temperature at which the resin is melt-extruded (the temperature immediately below the die) is preferably 150 ° C. or higher, more preferably 180 ° C. or higher, in the case of a polyolefin-based resin, from the viewpoint of improving desorption resistance. Moreover, 340 degrees C or less is preferable and 320 degrees C or less is more preferable from a viewpoint of reducing the fumes at the time of melt extrusion, and the odor of a film, and improving blocking resistance.

  The manufacturing method of the film of this invention has the process of carrying out powder spraying of the antiblocking agent on the roll surface of a cooling roll.

  Examples of the anti-blocking agent used in the present invention include inorganic anti-blocking agents such as natural silica, synthetic silica, zeolite, calcium carbonate, talc, and glass powder; polymethacrylic acid resin, cross-linked polystyrene resin, and cross-linked polymethyl methacrylate. Examples thereof include organic anti-blocking agents such as resins and copolymer resins of cross-linked methyl methacrylate and styrene. Furthermore, anti-blocking powders for gravure films, laminates, and printing made of corn starch starch (for example, Nikka Ricco Co., Ltd.) can be used.

  Anti-blocking agent powder can be sprayed onto the roll surface of the cooling roll using powder from anti-blocking agent powder, such as spray for electrostatic powder coating, anti-blocking powder spreader, and dust generator for dust performance test. There is a method of spraying on the roll surface of the cooling roll by the body spray device.

The above-mentioned spray for electrostatic powder coating is to charge the powder to be sprayed and spray the powder onto a grounded object by air or the like. As a method of charging the powder, Examples include a charging method using a corona and a charging method using friction. As the spray for electrostatic powder coating, a commercially available one can be used, and as a corona charger type electrostatic powder coating spray for performing corona charging, for example, Optigun A (X) manufactured by Landsburg Industry Co., Ltd. Examples include GX70000L manufactured by Nippon Parkerizing Co., Ltd. An example of the friction charging type electrostatic powder coating spray that performs friction charging is a tribomatic 500 hand gun manufactured by Nordson Corporation. In the powder spraying of the anti-blocking agent by the spray for electrostatic powder coating, the input air pressure is usually 0.6 to 1.0 MPa, and the spray amount per unit time of one spray is 1 to 50 g / min. The output air amount is usually 1 to 10 m ³ / hour. From the viewpoint of selectively spraying the powder onto the body to be sprayed, the output air amount is preferably 8 m ³ / hour or less, and from the viewpoint of improving the blocking resistance and slipping property of the film, the output air amount is 2 m. It is preferably ³ / hour or more. The set voltage is usually 20 to 150 kV, and the set current is 40 to 150 μA. From the viewpoint of spraying economically, the set voltage is preferably 120 kV or less, and the set voltage is preferably 120 μA or less, and from the viewpoint of selectively spraying powder onto an object to be sprayed, the set voltage is 40 kV or more, The set voltage is preferably 60 μA or more. Moreover, when the width | variety which performs the powder spray on the cooling roll surface is long, a plurality of sprays for electrostatic powder coating can be arranged in the width direction and used simultaneously. Further, the spray may be appropriately enclosed so that the powder is not scattered around.

  The above-mentioned anti-blocking powder spreader is a powder storage tank having an opening provided with a roller at the bottom, and rotates the roller to adhere the powder in the powder storage tank to the roller. At the same time, the adhering powder is released from the roller by corona discharge or the like, and sprayed onto the sprayed body passing under the roller. As the anti-blocking powder spreader, commercially available ones can be used, for example, Nikka Spray K-III manufactured by Nikka Corporation, Nikka Spray K-V manufactured by Nikka Corporation having a scattering prevention function, and the like. In the powder spraying of the anti-blocking agent by the anti-blocking powder spreader, the spray amount of the powder can be controlled by appropriately adjusting the roller speed of the spreader. Usually, the roller speed is 0.2 to 20 rpm. Further, the spreader may be appropriately enclosed so that the powder is not scattered around.

The dust generator for dust performance test described above is for spraying powder at a desired powder concentration and rated amount by stirring the powder with air or the like with a mixer. As a dust generator for a dust performance test, a commercially available device can be used, and examples thereof include Alpha Dust Departure DDP-1000. In the powder spraying of the anti-blocking agent by the dust generator for dust performance test, the dust concentration is usually 1 to 100 g / m ³ and the rated air amount is 0.1 to 1.0 m ³ / min. Further, the apparatus may be appropriately enclosed or a collection facility may be provided so that the powder does not scatter around.

The area average spray amount of the anti-blocking agent on the roll surface of the cooling roll is 0.5 g / m ² or more. If the area average spray amount is too small, the slipping property and antiblocking property may be lowered. Preferably it is 1 g / m ² or more. The area average spray amount is 3 g / m ² or less. If the area average spray amount is too large, the desorption resistance may be lowered. Preferably it is 2.5 g / m ² or less. The area average spray amount is the amount of powder sprayed onto the roll surface, and is a value per unit area of the portion sprayed with the powder. When the film-like molten resin continuously melt-extruded as in the continuous molding method is continuously pressed and cooled on the roll surface while rotating the cooling roll, and the film is taken up, the area average spray amount is Can be obtained by the following equation.
C = g / (W × V)
C: Area average spray amount (unit: g / m ² )
g: Amount of powder sprayed onto the roll surface per unit time (g / min)
W: Length in the roll width direction of the portion sprayed with powder on the surface of the cooling roll (unit: m)
V: Circumferential speed of roll by rotation of cooling roll (unit: m / min)

  The manufacturing method of the film of this invention has the process of crimping | bonding the melt-extruded film-form molten resin to the roll surface of the cooling roll by which the anti-blocking agent was spray-sprayed.

  Examples of a method for pressure-bonding the melt-extruded film-shaped molten resin to the roll surface of the cooling roll include a method of pressing the molten resin against the roll surface of the cooling roll using a pressure-bonding roll. As the pressure-bonding roll, a rubber roll made of silicon or neoprene, a flexible metal roll (for example, a flex roll made by Sumitomo Heavy Industries Modern) is used.

  The pressure at which the melt-extruded film-like molten resin is pressure-bonded to the roll surface of the cooling roll is preferably 4.9 kN / m or more from the viewpoint of improving desorption resistance as the pressing roll linear pressure. More preferably, it is 15 kN / m or more. Moreover, from a viewpoint of improving blocking resistance and slipperiness, it is preferably 24.5 kN / m or less, more preferably 24 kN / m or less.

  When the melt-extruded film-like molten resin is pressure-bonded to the roll surface of the cooling roll, for example, a base film is fed out to the pressure roll side of the molten resin and arranged in the order of cooling roll / molten resin / base film / crimp roll And it is good also as a multilayer film which press-bonds molten resin to the roll surface of a cooling roll with a press roll through this base film, and has the layer which consists of base materials.

  As the base film, a resin film, paper, woven fabric, metal foil or the like is used. Examples of the resin used for the substrate include polyamide resin, polyester resin, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polypropylene resin, polyethylene resin, ionomer resin, cellophane, polyvinylidene chloride, polystyrene, polychlorinated resin. Examples thereof include vinyl, polycarbonate, polymethyl methacrylate, polyurethane, fluororesin, polyacrylonitrile, polybutene resin, polyimide resin, polyarylate resin, and acetylcellulose. Moreover, as a base film, a multilayer film may be sufficient and the bonding film of paper, a textile fabric, metal foil, etc. and resin may be sufficient.

  The temperature of the roll surface of a cooling roll is the temperature which can cool the melt-extruded film-form molten resin, and is normally 5-80 degreeC. The temperature is preferably 15 ° C. or higher from the viewpoint of enhancing desorption resistance, blocking resistance, and slipperiness, and is preferably 40 ° C. or lower from the viewpoint of improving the roll release property of the film.

  As an apparatus for melt-extruding a resin from a T-die into a film shape and crimping the melt-extruded film-shaped molten resin to the roll surface of a cooling roll, an extruder with a T-die, a cooling roll, a pressure roll, a take-up machine, etc. A known T-die film forming apparatus provided can be used.

  When the present invention is performed by a continuous molding method, that is, a resin is continuously melt-extruded from a T-die in a film shape, and the continuously melt-extruded film-shaped molten resin is rotated on a roll surface while rotating a cooling roll. When the film is taken down and cooled, and the film is taken out, the line speed (cooling roll rotation speed (circumferential speed), take-up speed) is usually 20 to 200 m / min.

（Ｌｘ：Ｘ軸方向の基準長さ、 Ｌｙ：Ｙ軸方向の基準長さ） The arithmetic average roughness (Ra) of the surface on the cooling roll side of the film obtained by the production method of the present invention is 0.2 μm or more when having a base film from the viewpoint of enhancing blocking resistance and slipperiness. When it does not have a film, it is preferable that it is 0.3 micrometer or more, and it is preferable that it is 0.6 micrometer or less from a viewpoint of improving desorption resistance. The arithmetic average roughness (Ra) is such that the X-axis and the Y-axis are perpendicular to the average surface direction of the roughness curved surface, the Z-axis is taken in the longitudinal magnification direction (direction perpendicular to the average surface), When a roughness curved surface having a reference length in the X-axis direction and a reference length in the Y-axis direction is extracted from the roughness curved surface, and the extracted roughness curved surface is expressed by z = f (x, y), Is a value expressed in μm.

(Lx: reference length in the X-axis direction, Ly: reference length in the Y-axis direction)

  The arithmetic average roughness (Ra) is adjusted by appropriately changing the temperature at which the resin is melt-extruded, the roll surface temperature of the cooling roll, the area average spray amount of the antiblocking agent, the pressing roll linear pressure, the take-up speed, and the like. The

  The antiblocking agent occupancy ratio on the surface of the cooling roll side of the film obtained by the production method of the present invention is preferably 10% or more, and more preferably 13% or more, from the viewpoint of enhancing blocking resistance and slipperiness. Moreover, from a viewpoint of improving desorption resistance, 30% or less is preferable and 27% or less is more preferable. The anti-blocking agent occupancy is the ratio of the area occupied by the anti-blocking agent on the film surface, and the morphological image of the film surface is measured with a microscope or the like, and the morphological image of the film surface derived from the anti-blocking agent is obtained from the morphological image. An area is calculated | required by calculating the ratio of the area of the form image of the film surface derived from an antiblocking agent with respect to the whole area (100%) of a form image.

  The film obtained by the production method of the present invention is excellent in blocking resistance, slipperiness and anti-blocking agent desorption resistance. Moreover, transparency is also favorable. Therefore, it is used for various packaging materials such as food packaging materials, pharmaceutical packaging materials, and industrial materials.

Hereinafter, the present invention will be described with reference to examples and comparative examples.
Measurement of physical properties and evaluation in the examples were performed by the following methods.

(1) Density (Unit: kg / m ³ )
It measured according to the method prescribed | regulated to A method among JISK7112-1980. The sample was annealed according to JIS K6760-1995.

(2) Melt flow rate (MFR, unit: g / 10 minutes)
According to the method defined in JIS K7210-1995, the measurement was performed under the conditions of a load of 21.18 N and a temperature of 190 ° C.

(3) Sliding property (dynamic friction coefficient μk)
According to JIS K7125-1987, the dynamic friction coefficient between the surfaces on the cooling roll side of the film was measured. The smaller this value, the better the slipperiness. In addition, about the sample which does not slip, it described as "it does not slip."

(4) Blocking resistance (unit: g / 100 cm ² )
A test coater (manufactured by Yasui Seiki Co., Ltd.) was stacked with two films sampled in a strip of 10 cm width x 25 cm length so that the surface on the cooling roll side and the surface on the anti-cooling roll side were in contact with each other. ), And pressure bonding was performed under the conditions of roll temperature: 60 ° C., set pressure: 0.49 MPa, and processing speed: 0.5 m / min. The superposed film (effective measurement surface: width 10 cm × length 10 cm) was vertically tested using a Mackenzie blocking tester (manufactured by Shimadzu Corporation) in an atmosphere at a temperature of 23 ° C. and a humidity of 50% at a peeling load rate of 20 g / min. The load required to peel in the direction (without applying a shear force) was measured. The smaller this value, the better the blocking resistance.

(5) Desorption resistance The surface on the cooling roll side of the film was rubbed with a finger, and evaluation was performed in the following categories.
○: The anti-blocking agent hardly adheres to the finger.
Δ: The anti-blocking agent slightly adheres to the finger.
X: An anti-blocking agent adheres to a finger.

(6) Arithmetic mean roughness (Ra, unit: μm)
[Preparation of measurement sample]
After the surface of the cooling roll side of the film is washed with acetone, cut into a size of about 4 cm × 2 cm, and then pasted onto the slide glass with a double-sided tape so that the surface of the cooling roll side of the film becomes the measurement surface A measurement sample was obtained.
[Measurement]
Using an ultra-deep shape measuring microscope (VK-8510 manufactured by Keyence Co., Ltd., VK-8550 manufactured by Keyence Co., Ltd.), the height was measured under the following measurement conditions. In the measurement, it was confirmed that the measurement range in the height direction (DISTANCE) was sufficiently larger than the maximum height in the obtained height data.
<Measurement conditions>
-RUN MODE: Ultra-deep color-VIEW MODE: Light intensity data-Objective lens: CF IC EPI Plan 50x
(Nikon Corporation, magnification 50 times, numerical aperture 0.3, working distance 16.5 mm)
・ Optical zoom: x1
・ Digital zoom: x1
Measurement area: 66752 μm ² (298 μm (X axis) × 224 μm (Y axis))
-Number of pixels in the measurement area: 1024 pixels (X axis) x 768 pixels (Y axis)
・ DISTANCE: 65μm
・ PITCH: 0.02μm
[Calculation of arithmetic mean roughness]
Ra was obtained from the height data obtained by the measurement using the “surface roughness” measurement function of the analysis software (VK shape analysis application VK-H1W Ver.1.06 manufactured by Keyence Corporation). Prior to the measurement, the height data was smoothed (size: 7 × 7, number of executions: once).

(7) Occupancy rate of anti-blocking agent (unit:%)
Using an ultra-deep shape measuring microscope (VK-8510 manufactured by Keyence Co., Ltd., VK-8550 manufactured by Keyence Co., Ltd.), a morphological image on the film surface was measured under the same conditions as the above (6) arithmetic average roughness. The ratio of the area of the antiblocking agent to the film surface 66752 μm ² (298 μm (X axis) × 224 μm (Y axis)) was calculated. In the calculation, the “area (free line)” of the “measurement analysis” function of the analysis software (VK shape analysis application VK-H1W Ver.1.06 manufactured by Keyence Corporation) is used. By selecting the contour of the anti-blocking agent, the area of the film surface formed by the anti-blocking agent was determined.

Example 1
Using a T-die film forming apparatus [manufactured by Sumitomo Heavy Industries Modern Co., Ltd.], a polyethylene resin [Sumikasen CE4506 (MFR = 7 g / 10 min, density = 917 kg / m ³ )] manufactured by Sumitomo Chemical Co., Ltd.] (500 mm width) is continuously melt-extruded in a film form, and then the molten resin that has been melt-extruded into a film form is rotated on the roll surface of a cooling roll rotated at a circumferential speed of 30 m / min. : Silicon rubber) and continuously cooled by pressure bonding, and taken at 30 m / min to obtain a single-layer film having a thickness of 30 μm. In the film processing, the temperature of the molten resin immediately below the die was 250 ° C., the air gap was 150 mm, the cooling roll temperature was 20 ° C., and the pressing roll linear pressure was 19.6 kN / m. In film processing, electrostatic powder coating spray [Landsburg Industry Co., Ltd.] is positioned 800 mm vertically upward and 300 mm in the horizontal anti-T-die direction starting from the center of the cooling roll (diameter: 600 mm). Installed nozzle of Optigun A (X) automatic powder gun GA01: with 40mm nozzle], and inorganic anti-blocking using trace powder feeder [Alpha Millifeeder Macro C-60G (with bridge breaker)] Agent [inorganic anti-blocking agent (manufactured by Mizusawa Chemical Co., Ltd., synthetic aluminosilicate anti-blocking agent JC-50 (particle size = 5.0 μm))] is quantitatively supplied to the spray, and a gun controller [manufactured by the company] With the Optitronic powder gun controller CG03], spray conditions are changed to the following conditions And integer, from a nozzle of the spray towards the center of the cooling roll, the range of the width 330mm roll surface of a cooling roll, a powder spray was performed in an area-average spraying amount 2.0 g / m ^2. Table 1 shows the physical property evaluation results of the obtained single-layer film.
<Spraying conditions>
Setting voltage: 100 kV
Setting current: 100μA
Total air volume: 2.5m ³ / hour Air rate: 90%

Comparative Example 1
The same procedure as in Example 1 was conducted except that the anti-blocking agent was not sprayed with powder. Table 1 shows the physical property evaluation results of the obtained single-layer film.

Comparative Example 2
The same operation as in Example 1 was performed except that the pressure bonding was not performed. Table 1 shows the physical property evaluation results of the obtained single-layer film.

Example 2
Using a T-die film forming device [manufactured by Sumitomo Heavy Industries Modern Co., Ltd.], a polyethylene resin [Sumikasen L705 (MFR = 7 g / 10 min, density = 919 kg / m ³ )] manufactured by Sumitomo Chemical Co., Ltd.] (500 mm width) was continuously melt extruded into a film. A biaxially stretched polyamide film [Emblem ON, manufactured by Unitika Ltd., thickness = 16 μm] is fed to the pressure roll side of the molten resin melt-extruded into a film, and the molten resin melt-extruded into a film has a circumferential speed of 50 m. The roll surface of the cooling roll rotated at / min is cooled by continuously pressing with a press roll (material: silicon rubber) through a biaxially stretched polyamide film, taken up at a rate of 50 m / min, and having a thickness of 35 μm. A film (polyethylene resin / polyamide) was obtained. In the processing of the film, the temperature of the molten resin immediately below the die was 300 ° C., the air gap was 150 mm, the cooling roll temperature was 20 ° C., and the pressing roll linear pressure was 19.6 kN / m. In film processing, electrostatic powder coating spray [Landsburg Industry Co., Ltd.] is positioned 800 mm vertically upward and 300 mm in the horizontal anti-T-die direction starting from the center of the cooling roll (diameter: 600 mm). Installed Optigun A (X) Automatic Powder Gun GA01: 40mm Nozzle] nozzle and inorganic anti-blocking using trace powder feeder [Alpha Millifeeder Macro C-60G (with Bridge Breaker)] Agent [inorganic anti-blocking agent (manufactured by Mizusawa Chemical Co., Ltd., synthetic aluminosilicate anti-blocking agent JC-50 (particle size = 5.0 μm))] is quantitatively supplied to the spray, and a gun controller [manufactured by the company] With the Optitronic powder gun controller CG03], spray conditions are changed to the following conditions And integer, from a nozzle of the spray towards the center of the cooling roll, the range of the width 330mm roll surface of a cooling roll, a powder spray was performed in an area-average spraying amount 1.2 g / m ^2. Table 2 shows the physical property evaluation results of the obtained multilayer film.
<Spraying conditions>
Setting voltage: 100 kV
Setting current: 100μA
Total air volume: 2.5m ³ / hour Air rate: 90%

Example 3
The same procedure as in Example 2 was performed except that the area-average spray amount of the anti-blocking agent was 2.0 g / m ² and the circumferential speed and take-up speed of the cooling roll were 30 m / min. Table 2 shows the physical property evaluation results of the obtained multilayer film.

Comparative Example 3
The same procedure as in Example 2 was performed except that the anti-blocking agent was not sprayed and the circumferential speed and take-up speed of the cooling roll were set to 30 m / min. Table 2 shows the physical property evaluation results of the obtained multilayer film.

Comparative Example 4
The same procedure as in Example 2 was performed except that the area-average spray amount of the anti-blocking agent was 4.0 g / m ² and the circumferential speed and take-up speed of the cooling roll were 15 m / min. Table 2 shows the physical property evaluation results of the obtained multilayer film.

Comparative Example 5
Instead of the inorganic anti-blocking agent, an organic anti-blocking agent (Nippon Shokubai Co., Ltd., spherical fine particles, E-poster MA1010 (polymethyl methacrylate cross-linked product, particle size = 9.7 μm)) was used. The same operation as in Example 2 was performed except that the average spray amount was 0.38 g / m ² and the circumferential speed and take-up speed of the cooling roll were 80 m / min. Table 2 shows the physical property evaluation results of the obtained multilayer film.

Example 4
Another commercially available polyethylene resin [Sumikasen L211 (MFR = 2 g / 10 min, density = 924 kg / m ³ )] manufactured by Sumitomo Chemical Co., Ltd. was used as the polyethylene resin, and the circumferential speed and take-up speed of the cooling roll were set to 30 m / The same procedure as in Example 2 was conducted except that the powder spray amount of the anti-blocking agent was 2.0 g / m ² . Table 3 shows the physical property evaluation results of the obtained multilayer film.

Example 5
The same procedure as in Example 4 was performed except that an organic anti-blocking agent (Epaster MA1010) was used as the anti-blocking agent and the area average spray amount of the anti-blocking agent was 1.0 g / m ² . Table 3 shows the physical property evaluation results of the obtained multilayer film.

Comparative Example 6
The same procedure as in Example 4 was performed except that the anti-blocking agent was not sprayed with powder. Table 3 shows the physical property evaluation results of the obtained multilayer film.

Example 6
Using a T-die film forming device [manufactured by Sumitomo Heavy Industries Modern Co., Ltd.], a polyethylene resin [Sumikasen L705 (MFR = 7 g / 10 min, density = 919 kg / m ³ )] manufactured by Sumitomo Chemical Co., Ltd.] (500 mm width) was continuously melt extruded into a film. A biaxially stretched polyamide film [Emblem ON, manufactured by Unitika Co., Ltd., thickness = 16 μm] is fed to the pressure roll side of the molten resin melt-extruded into a film shape, and the molten resin melt-extruded into a film shape has a circumferential speed of 20 m. The roll surface of the cooling roll rotated at / min is cooled by continuously pressing with a press roll (material: silicon rubber) via a biaxially stretched polyamide film, taken up at a rate of 20 m / min, and a thickness of 35 μm A multilayer film (polyethylene resin / polyamide) was obtained. In the processing of the film, the temperature of the molten resin immediately below the die was 300 ° C., the air gap was 150 mm, the cooling roll temperature was 20 ° C., and the pressing roll linear pressure was 19.6 kN / m. In film processing, an anti-blocking powder spreader [Nikka Spray III manufactured by Nikka Corporation] is placed at a position 600 mm vertically upward from the center of the cooling roll (diameter: 600 mm) and 100 mm in the horizontal anti-T-die direction. ], The inorganic anti-blocking agent JC-50 is directed to the cooling roll at a rotation speed of the spreader roller of 20 rpm, and the area of the roll surface of the cooling roll is 300 mm wide. Powder spraying was performed at an average spray amount of 2.58 g / m ² . Table 4 shows the physical property evaluation results of the obtained multilayer film.

Example 7
The same procedure as in Example 6 was performed except that the circumferential speed and take-up speed of the cooling roll were 80 m / min and the powder spray amount of the antiblocking agent was 0.65 g / m ² . Table 4 shows the physical property evaluation results of the obtained multilayer film.

Comparative Example 7
Example 6 except that the circumferential speed and take-up speed of the cooling roll were 80 m / min, the rotation speed of the roller of the spreader was 8.5 rpm, and the powder spray amount of the antiblocking agent was 0.33 g / m ^2. The same was done. Table 4 shows the physical property evaluation results of the obtained multilayer film.

Comparative Example 8
Example 6 except that the circumferential speed and take-up speed of the cooling roll were 80 m / min, the rotation speed of the roller of the spreader was 2.0 rpm, and the powder spray amount of the anti-blocking agent was 0.10 g / m ^2. The same was done. Table 4 shows the physical property evaluation results of the obtained multilayer film.

Example 8
An organic anti-blocking agent (Eposter MA1010) was used as an anti-blocking agent, except that the circumferential speed and take-off speed of the cooling roll were 80 m / min, and the area average spray amount of the anti-blocking agent was 0.88 g / m ² . The same operation as in Example 6 was performed. Table 5 shows the physical property evaluation results of the obtained multilayer film.

Comparative Example 9
The same procedure as in Example 6 was performed except that an organic antiblocking agent (Eposter MA1010) was used as the antiblocking agent and the area average spray amount of the antiblocking agent was 3.51 g / m ² . Table 5 shows the physical property evaluation results of the obtained multilayer film.

Comparative Example 10
An organic anti-blocking agent (Eposter MA1010) is used as an anti-blocking agent, the circumferential speed and take-up speed of the cooling roll is 80 m / min, the rotation speed of the roller of the spreader is 2.0 rpm, and the area average spray amount of the anti-blocking agent Was carried out in the same manner as in Example 6 except that 0.08 g / m ² was set. Table 5 shows the physical property evaluation results of the obtained multilayer film.

Claims (5)

A step of melt-extruding a resin from a T-die into a film, a step of spraying an anti-blocking agent on the roll surface of a cooling roll at an area average spray amount of 0.5 to 3 g / m ² , a melt-extruded film-like A method for producing a film, comprising the step of pressure-bonding a molten resin to a roll surface of a cooling roll sprayed with a powder of an antiblocking agent.   The method for producing a film according to claim 1, wherein the resin is a polyolefin resin.   The temperature at which the resin is melt-extruded is 150 to 340 ° C., and the melt-extruded film-like molten resin is pressure-bonded to the roll surface with a pressing roll linear pressure of 4.9 to 24.5 kN / m. Item 3. The method for producing a film according to Item 1 or 2.   The method for producing a film according to any one of claims 1 to 3, wherein the anti-blocking agent is sprayed on the roll surface by spraying for electrostatic powder coating.   The method for producing a film according to any one of claims 1 to 3, wherein the anti-blocking agent is sprayed onto the surface of the roll by means of an anti-blocking powder spreader.