JP2012245708A - Resin film manufacturing device and resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin film manufacturing device capable of suppressing the generation of a defective portion and improving quality, and to provide the resin film manufactured by the manufacturing device.SOLUTION: A rubber roll 3 is formed of a roll-shaped iron core 31 and a rubber layer 32 formed on the surface of the iron core 31. The rubber layer 32 has two layers of an inner layer 32a formed at a side close to the iron core 31 and an outer layer 32b formed outside the inner layer 32a. The inner layer 32a is formed of either HTV-silicone rubber or RTV-silicone rubber whose durometer hardness is A60 to A80, and the outer layer 32b is formed of RTV-silicone rubber whose durometer hardness is A70 to A80.

Description

  The present invention relates to a resin film having optical properties and a resin film manufacturing apparatus.

  Optical sheets used for optical applications are widely used, for example, in liquid crystal cells combined with polarizing plates, retardation films, diffusion films, brightness enhancement films, and the like.

  Light transmission characteristics and reflection characteristics (hereinafter referred to as “optical characteristics”) in the optical sheet are determined by the material of the optical sheet, the state of the optical sheet surface, and the like. A resin material is often used as the material of the optical sheet. Some optical sheets have, for example, a concavo-convex shape formed on the surface of a resin film and a function of scattering light.

  The resin film having a concavo-convex shape formed on the surface thereof is generally a first cooling roll having a smooth outer peripheral surface by extruding a molten transparent resin from a die into a film shape, and a second cooling roll having an concavo-convex shape formed on the outer peripheral surface. Is obtained by transferring the concavo-convex shape of the second cooling roll and winding it around the second cooling roll, and then taking it out with a take-up roll.

  Patent Document 1 discloses a method for producing a resin film. In the method for producing a resin film disclosed in Patent Document 1, a resin material that is a pelletized thermoplastic resin is heated and melted, an extruder that extrudes the melted resin, and a molten state extruded from the extruder A resin film is manufactured using a resin film manufacturing apparatus including a die for extruding a resin into a film and a plurality of rolls that sandwich the resin extruded into a film from the die.

  Since the surface state of a plurality of rolls sandwiching the resin is reflected in the surface state of the resin film, for example, when it is desired to provide unevenness on the surface of the resin film, the surface of the roll is provided with unevenness and transferred to a plate. . In order to make the surface of the resin film flat, the roll surface is made flat.

JP 2009-196327 A

  The surface state of the roll is reflected in the surface state of the resin film. If there are unnecessary irregularities on the surface of the roll, the unnecessary irregularities are reflected on the surface of the resin film, causing defects. Will end up. Unnecessary irregularities on the roll surface may be caused by, for example, the material constituting the roll, or may be caused by the roll manufacturing process.

  The structure of the roll used for the resin film manufacturing apparatus includes a roll-shaped iron core and a rubber layer provided on the iron core surface. Further, the rubber layer is composed of two layers, and is composed of an inner layer provided on the side close to the iron core and an outer layer provided outside the inner layer.

  When the inventor of the present application uses a roll having such a configuration, a streak-like defect portion extending in the width direction is generated on the surface of the resin film, and further, the defect portion is generated at regular intervals in the flow direction of the resin film. I found a problem to do.

  The objective of this invention is providing the resin film manufactured with the manufacturing apparatus of the resin film which can suppress generation | occurrence | production of a defective part, and can improve quality, and the said manufacturing apparatus.

The present invention is a resin film manufacturing apparatus for manufacturing a resin film made of a thermoplastic resin by a melt extrusion molding method,
A film forming means for forming a film by extruding a molten thermoplastic resin into a film;
It consists of a 1st roll and a 2nd roll, and the rotating shaft of the said 1st roll and the rotating shaft of the said 2nd roll are parallel, The outer peripheral surface of the said 1st roll, and the outer periphery of the said 2nd roll It is a molding means arranged so as to abut the surface, by sandwiching the extruded film-like thermoplastic resin between the outer peripheral surface of the first roll and the outer peripheral surface of the second roll, A molding means for molding the surface shape of the film-like thermoplastic resin into a predetermined shape;
One of the first roll and the second roll is
A core made of a cylindrical or columnar metal member;
It is a rubber layer provided so as to cover the entire outer peripheral surface of the core material, and is composed of two rubber layers, an inner layer provided on the side close to the core material and an outer layer provided on the outer side of the inner layer,
The inner layer is a resin film manufacturing apparatus characterized in that it is formed of either high temperature vulcanized silicone rubber or room temperature vulcanized silicone rubber.

In the invention, it is preferable that the outer layer is made of room temperature vulcanized silicone rubber.
In the present invention, the inner layer has a durometer hardness of A60 to A80, and the outer layer has a durometer hardness of A70 to A80.

  According to the present invention, the inner layer and the outer layer are made of room temperature vulcanized silicone rubber having a durometer hardness of A70.

In the present invention, one of the first roll and the second roll is attached to the other roll so that the outer peripheral surface of the first roll and the outer peripheral surface of the second roll are in contact with each other. Further comprising a biasing device,
The biasing device is
A bearing portion of a rotating shaft of the first roll or the second roll;
A horizontal movable part for operating the bearing part in a horizontal direction;
And a pneumatic cylinder that fixes a rod to the bearing portion and applies a biasing force to the roll through the bearing portion.
The present invention is a resin film imparted with optical properties,
The arithmetic average roughness (Ra) based on JIS B0601: 1994 is 1.1 to 2.5 μm,
The ratio (Rz / Sm) of the ten-point average roughness (Rz) based on JIS B0601: 1994 and the average interval of unevenness (Sm) is 0.04 to 0.10,
A plurality of points are measured at equal intervals in the flow direction at the time of manufacture, and the standard deviation of haze when measuring a plurality of rows at equal intervals in the width direction is 1.0 or less. It is a resin film.

  According to the present invention, either one of the first roll and the second roll of the forming means is covered with a core made of a cylindrical or columnar metal member and the entire outer peripheral surface of the core. Thus, a rubber layer was provided. The rubber layer is composed of two layers, an inner layer provided on the side close to the core material and an outer layer provided on the outer side of the inner layer, and the inner layer is formed of either high temperature vulcanized silicone rubber or room temperature vulcanized silicone rubber. did.

  Thereby, the convex part of the surface of the rubber roll that has caused the defective part is reduced, and the generation of the defective part that occurs at regular intervals in the flow direction of the resin film can be suppressed, and the quality can be improved.

  Further, according to the present invention, the outer layer is preferably formed of room temperature vulcanized silicone rubber, the inner layer has a durometer hardness of A60 to A80, and the outer layer has a durometer hardness of A70 to A80. It is more preferable.

  According to the present invention, most preferably, the inner layer and the outer layer are made of room temperature vulcanized silicone rubber having a durometer hardness of A70.

  According to the invention, a pneumatic cylinder is used as a biasing device that biases one of the first roll and the second roll to the other roll.

  By changing the position control by the servo motor to pressure control in the past, it is possible to suppress variations in the surface state of the resin film.

  According to the present invention, the arithmetic average roughness (Ra) based on JIS B0601: 1994 is 1.1 to 2.5 μm, the ten-point average roughness (Rz) based on JIS B0601: 1994, and the average of the unevenness. The ratio (Rz / Sm) to the interval (Sm) is 0.04 to 0.10, and a plurality of points are measured at equal intervals in the flow direction at the time of manufacture. The standard deviation of the haze when measuring in a plurality of rows is 1.0 or less. Thereby, the resin film with uniform haze which is an optical characteristic can be provided.

It is a figure which shows typically the structure of the resin film manufacturing apparatus 100 which is embodiment of this invention. It is a figure which expands and shows the cross-sectional structure of the rubber roll 3 with which the manufacturing apparatus 100 is equipped. It is the schematic of the urging | biasing apparatus 7 seen from the rotating shaft direction of the rubber roll 3. FIG. It is sectional drawing of the horizontal movable part 73 and the rail 8 when it cut | disconnects by cut surface line AA of FIG. It is a schematic plan view of the urging device 7 when viewed from above.

  The present invention is a manufacturing apparatus for manufacturing a resin film using a melt extrusion molding method, and is characterized by a roll configuration and a roll pressing apparatus.

  FIG. 1 is a diagram schematically showing a configuration of a resin film manufacturing apparatus 100 according to an embodiment of the present invention.

  The resin film manufacturing apparatus 100 includes an extruder 1, a filtering device 12, a die 2, a rubber roll 3, a mat roll 4, a mirror roll 5, a take-up roll 6, and an urging device 7.

  The extruder 1 includes an unillustrated extruder cylinder, a heater, and an extruder screw. In the extruder cylinder, the extruder 1 melts the thermoplastic resin by heat from the heater and shear friction heat of the extruder screw, and extrudes the molten thermoplastic resin (molten resin) by the extruder screw. Send to filtration device 12.

  The filtration device 12 includes a polymer filter and performs a filtration process on the molten resin extruded from the extruder 1. Specifically, it is filtered by passing a molten resin through a polymer filter to remove foreign substances such as gelled products.

  The die 2 is formed by extruding the molten resin after the filtration treatment into a film shape. As the die 2, for example, a T die can be used.

  In the rubber roll 3 and the mat roll 4, the rotation axes of the two rolls are arranged on the same horizontal plane. The rubber roll 3 and the mat roll 4 may be disposed so that the outer peripheral surfaces are brought into contact with each other to form a nip portion, or the outer peripheral surfaces may be disposed with a predetermined gap (gap) therebetween. How to arrange may be set according to the characteristics required for the resin film to be manufactured. Below, the case where it arrange | positions so that a nip part may be formed is demonstrated.

  The die 2 is provided above the rubber roll 3 and the mat roll 4, and the discharge port of the die 2 is arranged to open downward. The discharge port of the die 2 is positioned vertically above the nip portion between the rubber roll 3 and the mat roll 4, and the film-like resin discharged from the die 2 extends vertically downward to rotate the rubber roll 3 and the mat roll 4. Sandwiched between.

  When the film-like resin discharged from the die 2 is sandwiched between the rubber roll 3 and the mat roll 4, the rubber layer of the rubber roll 3 is elastically deformed into a concave shape along the outer peripheral surface of the mat roll 4 via the film-like resin. As a result, the rubber roll 3 and the mat roll 4 come into contact with each other with a predetermined nip length via the film-like resin.

  The nip length is a length that allows the uneven shape formed on the surface of the mat roll 4 to be transferred to the film-like resin. In order to set the nip length to a predetermined value, it can be arbitrarily set by adjusting, for example, the rubber layer material and the rubber layer thickness of the rubber roll 3. The rubber roll 3 is preferably configured so that the surface temperature can be controlled.

  Since the film-like resin discharged from the die 2 is in a highly flexible state, the film surface shape corresponding to the outer surface of each roll can be obtained by being sandwiched between the rubber roll 3 and the mat roll 4. .

  The rubber roll 3 includes a metal core material and a rubber layer provided on the surface of the core material, and an iron core is used as the core material. The rubber roll 3 has a flat outer surface, that is, the surface of the rubber layer, and flattens one surface of the film-like resin on the rubber roll 3 side. The detailed configuration of the rubber roll 3 will be described later.

  The mat roll 4 is a metal roll whose surface has been subjected to minute unevenness, and transfers the uneven shape to the other surface of the film-like resin on the mat roll 4 side. In detail, for example, a metal roll that can control the temperature of the roll surface through fluid, steam, etc. inside a roll such as a drilled roll or a spiral roll having a hollow structure, and the outer peripheral surface of these metal rolls. What formed desired uneven | corrugated shape by sandblasting, engraving, etc. can be used.

  Examples of the uneven shape formed on the outer peripheral surface of the mat roll 4 include a mat shape having an arithmetic average surface roughness (Ra) of 0.1 to 10 μm, a prism shape and a lens shape having a pitch and height of 5 to 500 μm, and the like. Can be adopted. The arithmetic average surface roughness (Ra) is a value obtained by measuring with a surface roughness meter in accordance with JIS B0601-2001.

  The rubber roll 3 and the mat roll 4 are both held at a temperature lower than that of the film-like resin, and the film-like resin is cooled to a predetermined temperature by being sandwiched between the rubber roll 3 and the mat roll 4. Is done. By this cooling, the flexibility of the film-like resin is lowered, and the film-shaped resin is conveyed along with the rotation of the mat roll 4 in a state of being wound around the outer peripheral surface of the mat roll 4.

  Further, a mirror roll 5 is provided on the opposite side of the mat roll 4 from the rubber roll 3. The mirror surface roll 5 is made of a cylindrical member having the same outer diameter as the rubber roll 3 and the mat roll 4, and the rotation axis is arranged on the same horizontal plane as the rotation axes of the rubber roll 3 and the mat roll 4.

  The mirror roll 5 is a metal roll formed in the same manner as the mat roll 4, and the outer surface is mirror-finished.

  The film-like resin is wound around the outer peripheral surface of the lower side of the mat roll 4 by almost a half turn, and then wound around the outer surface of the mirror roll 5 by about 1/4 turn, and is separated at the upper part in the vertical direction of the mirror roll 5. Then, it is taken up by the take-up roll 6 in the horizontal direction. In order to cool the resin film more slowly, a plurality of cooling rolls are provided between the mirror roll 5 and the take-up roll 6, and the film-like resin is wound around the next cooling roll in order from the mirror roll 5. You may make it rotate.

  FIG. 2 is an enlarged view showing a cross-sectional configuration of the rubber roll 3 provided in the manufacturing apparatus 100. The rubber roll 3 includes a roll-shaped iron core 31 and a rubber layer 32 provided on the surface of the iron core 31. Further, the rubber layer 32 includes two layers, and includes an inner layer 32a provided on the side close to the iron core 31, and an outer layer 32b provided on the outer side of the inner layer 32a.

  As described above, in the conventional rubber roll, streak defect portions are generated on the surface of the resin film at regular intervals in the flow direction of the resin film over the entire width of the resin film. The surface state of the defective portion is different from the surface state of other portions, and desired optical characteristics cannot be obtained in the defective portion.

  By the way, the rubber layer 32 is formed by attaching a layered rubber member to the outer surface of the iron core 31. In the conventional rubber layer, the inner layer is made of ethylene-propylene-diene rubber (EPDM) and the outer layer is made of room temperature vulcanizing (RTV) silicone rubber. When EPDM is used for the inner layer, the seam portion when the inner layer is bonded becomes a minute convex portion, and even if the outer layer is provided, the convex portion cannot be absorbed and remains on the outer surface of the rubber layer as a convex portion. The seam portion is parallel to the axial direction of the rubber roll, and the convex portion remains on the outer surface in parallel to the axial direction. This convex part causes a defective part on the surface of the resin film. The joint portion occurs as one streak portion on the outer surface of the inner layer, and the convex portion similarly remains as one streak portion. Since the rubber roll is pressed against the film-like resin while rotating, defective portions are generated at regular intervals in the flow direction according to the rotation period of the rubber roll.

  The inventor of the present application formed the inner layer 32a with high-temperature vulcanizing (HTV) silicone rubber instead of EPDM in order to suppress the occurrence of convex portions of the rubber layer 32. The outer layer 32b was formed of the same RTV silicone rubber as in the prior art. In addition, the hardness of the HTV silicone rubber of the inner layer 32a was set to A80 as the durometer hardness specified in JIS K6253, and the hardness of the RTV silicone rubber of the outer layer 32b was set to A80 as the durometer hardness. Thereby, the defective part of the resin film which generate | occur | produced with the conventional rubber roll reduced.

  Furthermore, in order to reduce a defective part, the material which forms the inner layer 32a was examined. By changing the inner layer 32a to HTV silicone rubber having a durometer hardness of A60, the defective portion was further reduced. At this time, the outer layer 32b was kept as an RTV silicone rubber having a durometer hardness of A80.

  Here, the outer layer 32b is changed to RTV silicone rubber having a durometer hardness A70, and the inner layer 32a is changed to RTV silicone rubber having the same durometer hardness A70 as that of the outer layer 32b, so that a streak-like defect portion hardly occurs. It was. When the inner layer 32a and the outer layer 32b are RTV silicone rubber having the same durometer hardness A70 as described above, it is not necessary to clearly distinguish the inner layer 32a and the outer layer 32b, and the RTV silicone having a predetermined thickness of durometer A70. A rubber layer 32 made of rubber may be provided.

  Regarding the two layers constituting the rubber layer 32 of the rubber roll 3, the inner layer 32a is formed of either HTV silicone rubber or RTV silicone rubber having a durometer hardness of A60 to A80, and the outer layer 32b has a durometer hardness of A70 to A70. By forming with R80 silicone rubber of A80, it is possible to suppress the occurrence of defective portions of the resin film.

  The hardness of the rubber layer 32 can be arbitrarily set, for example, by adjusting the degree of crosslinking or composition of the rubber material constituting the rubber layer.

  The surface temperature (T) of the mat roll 4 is (Th−60 ° C.) ≦ T ≦ (Th + 30 ° C.), preferably (Th−30 ° C.) ≦ T ≦ with respect to the thermal deformation temperature (Th) of the film-like resin. (Th + 20), more preferably (Th−20 ° C.) ≦ T ≦ (Th + 10 ° C.).

  The surface temperature of the rubber roll 3 is 0 to 70 ° C., preferably 20 to 40 ° C. In particular, when the surface temperature of the rubber roll 3 exceeds 70 ° C., the resin film may adhere to the surface of the rubber roll 3 and wind around the rubber roll 3.

  The surface temperature of the mirror roll 5 and each cooling roll after the mirror roll 5 may be set to an arbitrary surface temperature, and is not particularly limited, but is usually ± 15 with respect to the thermal deformation temperature (Th) of the thermoplastic resin. A temperature of about ° C is preferred.

  Although it does not specifically limit as heat deformation temperature (Th) of a thermoplastic resin, Usually, it is 60-200 degreeC. The heat distortion temperature (Th) of the thermoplastic resin is a temperature measured according to ASTM D-648.

  The take-up roll 6 includes a pair of upper roll 6a and lower roll 6b. Examples of the upper roll 6a and the lower roll 6b include a rubber roll and a metal roll. The lower roll 6b is connected to rotation driving means such as an electric motor, and the upper roll 6a is rotatably arranged so as to be in contact with the lower roll 6b, and the upper roll 6a is also rotated by the rotation of the lower roll 6b. It is configured. Therefore, the upper roll 6a and the lower roll 6b rotate at the same peripheral speed. As long as the peripheral speeds of the upper roll 6a and the lower roll 6b are the same, the configuration opposite to the above configuration, that is, the upper roll 6a is connected to the rotation driving means, and the lower roll 6b is connected to the upper roll 6a. The upper roll 6a and the lower roll 6b may both be connected to the rotation driving means.

  The resin film as a product taken up by the take-up roll 6 preferably has a thickness of 30 to 300 μm. On the other hand, if the thickness is less than 30 μm, the above-described roll configuration cannot stably obtain a resin film, and if it exceeds 300 μm, it is difficult to handle as a film. The thickness of the resin film can be adjusted by the thickness of the film-like resin extruded from the die 2, the contact thickness between the rubber roll 3 and the mat roll 4, and the length of the nip portion.

  Since the resin film has an uneven shape on the surface and has a function of scattering light, for example, a liquid crystal cell combined with a polarizing plate, a retardation film, a diffusion film, a brightness enhancement film, etc. The present invention can be applied to films, lighting films, building material films, and the like, but the present invention is not limited to these applications.

  FIG. 3 is a schematic view of the urging device 7 viewed from the direction of the rotation axis of the rubber roll 3. 4 is a cross-sectional view of the horizontal movable portion 73 and the rail 8 when cut along the cutting plane line AA of FIG. FIG. 5 is a schematic plan view of the biasing device 7 as viewed from above.

  As described above, the rubber roll 3 is urged to the mat roll 4 by the urging device 7 so that the outer peripheral surface of the rubber roll 3 and the outer peripheral surface of the mat roll 4 come into contact with each other.

  The biasing device 7 includes a bearing portion 72 of the rotating shaft 33 of the rubber roll 3, a horizontal movable portion 73 that operates the bearing portion 72 in the horizontal direction, a rod fixed to the bearing portion 72, and a roll via the bearing portion 72. And a pneumatic cylinder 71 for applying an urging force to.

  The bearing portion 72 may be a member that rotatably supports the rotating shaft 33 of the rubber roll 3, and a sliding bearing, a rolling bearing, or the like can be used.

  The bearing portion 72 is formed in a rectangular parallelepiped shape in which the rotation shaft 33 penetrates and a through-hole portion 72a that supports the rotation shaft 33 is provided in the central portion. A horizontal movable portion 73 is fixed to the lower surface of the bearing portion 72. The horizontal movable portion 73 is a guide portion provided with an internal space so as to embrace the rail 8 extending in a direction parallel to the contact direction of the rubber roll 3 and the mat roll 4 from above and from both sides. The horizontal movable portion 73 slides along the rail 8, and the bearing portion 72 also slides along the rail 8 along with the horizontal movable portion 73. Both the bearing portion 72 and the horizontal movable portion 73 are provided at both ends in the axial direction of the rotation shaft 33 so as to support the rotation shaft 33.

  By the movement of the bearing portion 72 and the horizontal movable portion 73, the supported rotary shaft 33 can be moved in the horizontal direction. The rubber roll 3 and the mat roll 4 are disposed so as to be adjacent to each other in the horizontal direction, and the rubber roll 3 and the mat roll 4 can be brought into contact with or separated from each other by the movement of the rotating shaft 33.

  The pneumatic cylinder 71 is provided so that the stroke direction of the rod 71a is parallel to the horizontal direction, and the rod 71a is on the side farthest from the mat roll 4 on the side surface of the bearing portion 72, that is, on the upstream side in the transport direction of the resin film. Fixed to the side of the. The pneumatic cylinder 71 is fixed so that the rubber roll 3 and the mat roll 4 form a nip portion having a predetermined size. The mat roll 4 is fixed so as not to move. When the rubber roll 3 and the mat roll 4 are in contact with each other, the bearing portion 72 presses the rod 71a with a constant pressure in a contracting direction, and the pneumatic cylinder 71 is compressed air. Thus, the bearing 72 is pushed back through the rod 71a with a force that balances this pressure.

  When the film-like resin is sandwiched between the nip portions of the rubber roll 3 and the mat roll 4, a force is applied in a direction in which the rubber roll 3 is separated from the mat roll 4. This force tries to push the rod 71a of the pneumatic cylinder 71 through the bearing portion 72, but the bearing portion 72 is pushed back through the rod 71a by the enclosed compressed air, and the balance of the force is maintained. .

  Conventionally, the horizontal displacement of the rotating shaft 33 of the rubber roll 3 when the film-like resin is sandwiched between the rolls is detected by a force transducer, and the rotating shaft 33 is used by using a servo motor so that the position of the rubber roll 3 is constant. Was performing position control. However, it is difficult to follow fluctuations in the thickness of the film-like resin, and variations in the surface state of the resin film, that is, variations in optical characteristics cannot be reduced.

  As described above, when the pressure control is changed so that the pressing force is constant by the pneumatic cylinder 71, it is possible to sufficiently follow the thickness variation of the film-like resin and reduce the variation in the surface state of the resin film. It became.

  Further, a pneumatic cylinder 81 may be provided on the opposite side of the pneumatic cylinder 71. The pneumatic cylinder 81 is provided so that the stroke direction of the rod 81a is parallel to the horizontal direction. The rod 81a is a side surface of the bearing portion 72 that is close to the mat roll 4, that is, a side surface on the downstream side in the resin film conveyance direction. It is provided so that it may contact | abut. The pneumatic cylinder 81 and the pneumatic cylinder 71 are fixed so that the rubber roll 3 and the mat roll 4 form a nip portion having a predetermined size. When the thickness of the film-like resin changes, the distance between the rubber roll 3 and the mat roll 4 varies. When the bearing portion 72 presses the rod 71a in the contracting direction due to a change in distance, the pneumatic cylinder 71 pushes the bearing portion 72 back through the rod 71a with compressed air. Since the rod 81a is not fixed to the bearing portion 72, when the bearing portion 72 fluctuates beyond the stroke of the rod 81a, the bearing portion 72 is separated from the rod 81a. Further, when the bearing 72 extends the rod 71a due to a change in distance, when the bearing 72 comes into contact with the rod 81a and further presses the rod 81a, the pneumatic cylinder 81 causes the rod 81a to be compressed by compressed air. The bearing 72 is pushed back through.

The thermoplastic resin used as the raw material of the resin film manufactured with the manufacturing apparatus of this invention is demonstrated.
Examples of the thermoplastic resin that can be used in the present invention include rubber-reinforced styrene resins such as polystyrene, high impact polystyrene, and medium impact polystyrene, styrene-acrylonitrile copolymer (SAN resin), and acrylonitrile-butyl acrylate rubber. Styrene copolymer (AAS resin), acrylonitrile-ethylenepropyl rubber-styrene copolymer (AES), acrylonitrile-polyethylene chloride-styrene copolymer (ACS), ABS resin (for example, acrylonitrile-butadiene-styrene copolymer, Styrenic resins such as acrylonitrile-butadiene-styrene-alphamethylstyrene copolymer, acrylonitrile-methyl methacrylate-butadiene-styrene copolymer), and polymethyl Acrylic resins such as tacrylate (PMMA), olefin resins such as low density polyethylene (LDPE), high density polyethylene (HDPE) and polypropylene (PP), vinyl chloride resins such as polyvinyl chloride and polyvinylidene chloride, ethylene chloride Vinyl chloride vinyl acetate copolymer, vinyl chloride copolymer resins such as ethylene vinyl chloride copolymer, polyester resins such as polyethylene terephthalate (PETP, PET), polybutylene terephthalate (PBTP, PBT), polycarbonate (PC), modified Polycarbonate resins such as polycarbonate, polyamide resins such as polyamide 66, polyamide 6 and polyamide 46, polyacetal (POM) resins such as polyoxymethylene copolymers and polyoxymethylene homopolymers, other en Nearing resin, super engineering resin, for example, polyethersulfone (PES), polyetherimide (PEI), thermoplastic polyimide (TPI), polyetherketone (PEK), polyetheretherketone (PEEK), polyphenylene sulfide (PSU) And cellulose derivatives such as cellulose acetate (CA), cellulose acetate butyrate (CAB), and ethyl cellulose (EC), and liquid crystal polymers such as liquid crystal polymers and liquid crystal aromatic polyesters. Also, thermoplastic polyurethane elastomer (TPU), thermoplastic styrene butadiene elastomer (TSBC), thermoplastic polyolefin elastomer (TPO), thermoplastic polyester elastomer (TPEE), thermoplastic vinyl chloride elastomer (TPVC), thermoplastic polyamide elastomer (TPAE) ) Etc. can also be used. In the present embodiment, a blend of one or more thermoplastic resins may be used, or an additive or the like may be contained.

  As a resin film manufactured by the manufacturing apparatus as described above, a resin film having a uniform haze as an optical characteristic is obtained.

  The resin film of the present invention has an arithmetic average roughness (Ra) based on JIS B0601: 1994 of 1.1 to 2.5 μm, preferably 1.5 to 2.1 μm. Further, the ratio (Rz / Sm) of the ten-point average roughness (Rz) based on JIS B0601: 1994 and the average interval (Sm) of the irregularities is 0.04 to 0.10, preferably 0.05 to 0. .09.

  Here, Rz / Sm is a parameter having a correlation with haze. The larger this ratio is, the larger the inclination angle of the unevenness on the surface of the resin film is, and the incident light to the resin film is strongly scattered, so the haze increases. By defining the range of Rz / Sm, the resin film of the present invention is specified to have a surface state that provides a suitable range of haze.

  Furthermore, in the resin film of the present invention, the haze is measured at a plurality of points (preferably 8 points or more) at regular intervals in the flow direction at the time of manufacture, and this is used as a single measurement column. The standard deviation of all measurement results (128 points) when measured (preferably 16 columns or more) is 1.0 or less. Thereby, the resin film of the uniform surface state with few dispersion | variations in haze is obtained.

(Example)
Polycarbonate (Caliber 301-10, manufactured by Sumitomo Dow Co., Ltd.) was used as a thermoplastic resin as a raw material. The raw material resin was melted and extruded by a uniaxial extruder (manufactured by Toshiba Machine Co., Ltd.) having a cylinder diameter of 115 mm, and a film-like resin was discharged at a discharge rate of 330 kg / h by a T-die having a set temperature of 270 ° C. and a full width of 1900 mm. .

  The rubber roll 3 and the mat roll 4 are arranged with a space therebetween and nipped so as to be in close contact with the discharged film-like resin. The mirror roll 5 was arranged with a 1.5 mm gap from the mat roll 4. The mat roll 4 is an iron roll (surface chrome plating treatment) having an outer diameter of 400 mm, and is provided with a minute uneven shape (Ra = 2.7 μm) on its surface by blast treatment. The rubber roll 3 is a RTV silicone rubber layer having a durometer hardness A70 of 10 mm thickness as a rubber layer 32 on the surface of an iron core having an outer diameter of 380 mm (the inner layer 32a and the outer layer 32b are made of RTV silicone rubber having the same durometer hardness A70). Is provided.

  The surface temperature of the rubber roll 3 was set to 40 ° C., the surface temperature of the mat roll 4 was set to 130 ° C., and the surface temperature of the mirror roll 5 was set to 140 ° C.

In the pneumatic cylinder 71, the air pressure upstream of the operation side was 0.5 MPa, the air pressure downstream of the operation side was 0.14 MPa, the air pressure upstream of the drive side was 0.5 MPa, and the air pressure downstream of the drive side was 0.16 MPa.
The produced resin film had a thickness of 130 μm and a width dimension of 1700 mm.

(Comparative example)
Except that the pressing force of the rubber roll 3 and the mat roll 4 is set to 1.5 to 1.6 kN on the operation side and 1.8 to 1.9 kN on the driving side using a servo motor instead of the pneumatic cylinder. The same was done.

(Evaluation method)
The optical properties of the obtained resin film were evaluated by measuring the haze of the resin film. The sample haze was measured using a haze meter HM-150 (Murakami Color Research Laboratory Co., Ltd.). As an evaluation sample, one round (length: 1600 mm) wound around a roll is sampled and measured at 8 points at regular intervals in the flow direction, and this is measured as 16 measurement columns at equal intervals in the width direction. did. Therefore, a total of 128 measurement positions are provided.

  The standard deviation was calculated from the haze of 8 points for each measurement column, and the arithmetic average value of the calculated standard deviation for 16 columns was calculated.

  The resin film sample manufactured in the example has an arithmetic average value of standard deviation as small as 0.58, and the resin film sample manufactured in the comparative example has an arithmetic average value of standard deviation of 1.74 compared to the example. It was big. This indicates that the variation in haze in the flow direction and the width direction of the resin film is smaller in the example than in the comparative example.

  Furthermore, the arithmetic average roughness Ra and the ratio (Rz / Sm) of the ten-point average roughness (Rz) and the average interval (Sm) of the irregularities were also measured. These were measured using a surface roughness measuring machine Surf Test SJ-201 manufactured by Mitutoyo Corporation. The measurement position is 128 points as with haze. The arithmetic average value of the measured values at 128 points was calculated for both the examples and comparative examples. In the example, Ra (average value) was 1.6 μm, and Rz / Sm (average value) was 0.065. In the comparative example, Ra (average value) was 1.6 μm, and Rz / Sm (average value) was 0.058.

DESCRIPTION OF SYMBOLS 1 Extruder 2 Die 3 Rubber roll 4 Matt roll 5 Mirror roll 6 Take-up roll 7 Take-up roll 7 Energizing device 8 Rail 31 Iron core 32 Rubber layer 32a Inner layer 32b Outer layer 33 Rotating shaft 71 Pneumatic cylinder 71a Rod 72 Bearing part 73 Horizontal movable part 100 Resin film manufacture apparatus

Claims (6)

A resin film manufacturing apparatus for manufacturing a resin film made of a thermoplastic resin by a melt extrusion molding method,
A film forming means for forming a film by extruding a molten thermoplastic resin into a film;
It consists of a 1st roll and a 2nd roll, and the rotating shaft of the said 1st roll and the rotating shaft of the said 2nd roll are parallel, The outer peripheral surface of the said 1st roll, and the outer periphery of the said 2nd roll It is a molding means arranged so as to abut the surface, by sandwiching the extruded film-like thermoplastic resin between the outer peripheral surface of the first roll and the outer peripheral surface of the second roll, A molding means for molding the surface shape of the film-like thermoplastic resin into a predetermined shape;
One of the first roll and the second roll is
A core made of a cylindrical or columnar metal member;
It is a rubber layer provided so as to cover the entire outer peripheral surface of the core material, and is composed of two rubber layers, an inner layer provided on the side close to the core material and an outer layer provided on the outer side of the inner layer,
The inner layer is formed of either high temperature vulcanized silicone rubber or room temperature vulcanized silicone rubber.   2. The resin film manufacturing apparatus according to claim 1, wherein the outer layer is made of room temperature vulcanized silicone rubber.   The resin film manufacturing apparatus according to claim 1, wherein the inner layer has a durometer hardness of A60 to A80, and the outer layer has a durometer hardness of A70 to A80.   2. The resin film manufacturing apparatus according to claim 1, wherein the inner layer and the outer layer are made of room temperature vulcanized silicone rubber having a durometer hardness of A70. A biasing device that biases one of the first roll and the second roll toward the other so that the outer circumferential surface of the first roll and the outer circumferential surface of the second roll are in contact with each other. Further comprising
The biasing device is
A bearing portion of a rotating shaft of the first roll or the second roll;
A horizontal movable part for operating the bearing part in a horizontal direction;
The resin film manufacturing apparatus according to claim 1, further comprising: a pneumatic cylinder that fixes a rod to the bearing portion and applies a biasing force to the roll through the bearing portion. . A resin film with optical properties,
The arithmetic average roughness (Ra) based on JIS B0601: 1994 is 1.1 to 2.5 μm,
The ratio (Rz / Sm) of the ten-point average roughness (Rz) based on JIS B0601: 1994 and the average interval of unevenness (Sm) is 0.04 to 0.10,
A plurality of points are measured at equal intervals in the flow direction at the time of manufacture, and the standard deviation of haze when measuring a plurality of rows at equal intervals in the width direction is 1.0 or less. Resin film.

Images