TW201910815A - Optical film manufacturing apparatus and manufacturing method - Google Patents

Abstract

The present invention provides an apparatus and a method for manufacturing an optical film having good quality. The optical film manufacturing apparatus 1 performs moisture conditioning processing for adjusting the moisture content ratio of the raw material film 5 while conveying the raw material film 5. The optical film manufacturing apparatus 1 includes one or more transfer openings 30 each having an opening 31 for loading or unloading the raw material film 5, a humidity control furnace 3 for performing a humidity control process, and a dew condensation suppressing device for suppressing dew condensation on the outer wall surface of the opening portion 30. The dew condensation suppressing device is installed in at least one of the conveying openings 30.

Description

   Device and method for manufacturing optical film   

The present invention relates to a device and method for manufacturing an optical film.

The image display device (a liquid crystal display device, an organic EL display device, etc.) can use various optical films such as a polarizing plate and a retardation plate. An optical film is generally manufactured by continuously rolling out a long raw film and carrying out various processes while conveying it. One of the treatments performed on the raw material film is known as a humidity-controlling treatment such as humidification treatment of the raw material film (for example, Patent Document 1).

    [Prior technical literature]         [Patent Literature]    

[Patent Document 1] Japanese Patent Laid-Open No. 2016-224423

An object of the present invention is to provide an optical film manufacturing apparatus and a manufacturing method for manufacturing an optical film by performing a humidity control process, and an optical film manufacturing apparatus and a manufacturing method capable of manufacturing an optical film having good quality.

The present invention provides a manufacturing apparatus and a manufacturing method of an optical film described below.

[1] An optical film manufacturing device, which is a humidity conditioning processor that adjusts the moisture content of the raw material film while conveying the raw material film, and includes: a humidity conditioning furnace, which has more than one for carrying in Or carry out the opening for conveyance provided with an opening of the raw material film and perform the humidity control treatment; and a dew condensation suppressing device for suppressing dew condensation on the outer wall surface of the opening for conveyance; the dew condensation suppressing device is provided To at least one of the aforementioned transport openings.

[2] The apparatus for manufacturing an optical film according to the item [1], wherein the humidity control furnace is a humidification furnace that performs a humidification treatment on humidifying the raw material film.

[3] The device for manufacturing an optical film according to [1] or [2], wherein the condensation suppressing device is at least one of the following: a suction device for sucking from the transporting device Humidity-controlling gas in the humidity-controlling furnace flowing out of the openings of the openings; air supply means for supplying air to the openings of the openings for the conveyance in a curtain shape; and heating means for heating The outer wall surface of the transport opening.

[4] The device for producing an optical film according to item [3], wherein the dew condensation suppressing device is the suction device, the suction device is outside the humidity control furnace, and passes through the opening for conveyance. At least the upper side of the film surface of the raw material film in the opening is provided along the opening.

[5] The device for manufacturing an optical film according to item [3] or [4], wherein the dew condensation suppressing device is the aforementioned suction device, and the aforementioned suction device is a suction box.

[6] The device for manufacturing an optical film according to any one of [3] to [5], wherein the dew condensation suppressing device is the suction device, and the suction device further has a function of heating the suction The heating part of the humidity control gas.

[7] The device for manufacturing an optical film according to item [3], wherein the dew condensation suppressing device is the air supply device, and the temperature of the air supplied by the air supply device is higher than the dew point temperature of the humidity-controlling gas. temperature.

[8] A method for manufacturing an optical film, while carrying out a humidity control process for adjusting the moisture content of the raw material film while conveying the raw material film, and the humidity control process is performed on a material having one or more openings for conveyance. It is carried out in a humidity-controlling furnace, and the opening for conveyance is provided with an opening for carrying in or out the raw material film, and at least one of the opening for conveyance suppresses dew condensation on the wall surface outside the opening for conveyance deal with.

[9] The method for producing an optical film according to the item [8], wherein the humidity control treatment is a humidification treatment.

[10] The method for producing an optical film according to the item [8] or [9], wherein the dew condensation suppressing process is at least one of the following: a suction process, which sucks from the transport opening The humidity-conditioning gas in the humidity-controlling furnace flowing out of the opening; the air supply treatment is to supply air to the opening portion for transportation; and the heating treatment is to heat the outer wall surface of the opening portion for transportation. .

[11] The method for manufacturing an optical film according to the item [10], wherein the condensation prevention treatment is at least one of the suction treatment and the heating treatment, and the thickness of the raw material film is 1 μm or more and 200 μm or less. the following.

[12] The method for producing an optical film according to the item [10] or [11], wherein the condensation suppression process is the aforementioned suction process, and the aforementioned suction process is external to the humidity control furnace, and The humidity-controlling gas is sucked through at least the upper side of the film surface of the raw material film in the opening of the transport opening.

[13] The method for producing an optical film according to any one of [10] to [12], wherein the dew condensation suppressing treatment is the aforementioned suction treatment, and then the humidified gas after the suction is heated Heat treatment.

[14] The method for producing an optical film according to the item [10], wherein the dew condensation suppression process is the air supply process, and the temperature of the air supplied in the air supply process is higher than that in the humidity control furnace. The temperature of the dew point temperature of the humidity control gas.

[15] The method for producing an optical film according to any one of [8] to [14], wherein the optical film is a polarizing film, a protective film attached to the polarizing film, and a polarizing film. Any one of the polarizing plates to which the protective film is bonded on one or both sides.

According to the present invention, an optical film having good quality can be manufactured by carrying out humidity control treatment while conveying a raw material film.

1‧‧‧ Optical film manufacturing device

3‧‧‧ Humidity Controlling Furnace

5‧‧‧ raw film

7‧‧‧Suction device (condensation suppression device)

30‧‧‧portion opening

30a‧‧‧Moving Department

30b‧‧‧moved out

31‧‧‧ opening

31a‧‧‧Mounting opening

31b‧‧‧Opening opening

61‧‧‧Upper roller

62‧‧‧Lower roller

FIG. 1 is a side view schematically showing an example of the vicinity of a humidity control furnace of an optical film manufacturing apparatus of the present invention.

The optical film manufacturing device of the present invention is a humidity conditioning processor for adjusting the moisture content of the raw material film while conveying the raw material film, and includes a humidity control furnace having more than one material film for carrying in or out of the raw material film. It has a transport opening with an opening and is used for humidity control treatment; and a dew condensation suppressing device is used to suppress condensation on the wall surface outside the transport opening; the dew suppression device is provided at least one transport opening .

In addition, the method for manufacturing an optical film of the present invention is a person who carries out a humidity-conditioning treatment to adjust the moisture content of the material film while conveying the material film, and the humidity-conditioning treatment includes one or more openings for conveyance. The opening for conveyance is provided with an opening for carrying in or out the raw material film, and at least one of the opening for conveyance performs a dew condensation suppressing process for suppressing dew on the wall surface outside the opening for conveyance.

The humidity control treatment for adjusting the moisture content of the raw material film refers to the treatment for adjusting the water content of the raw material film. The raw material film refers to a film at least before the humidity control treatment, and the optical film refers to a film manufactured by subjecting the raw material film to at least a humidity control treatment. The optical film may be a processor other than a humidity control treatment applied to the raw film. In addition, hereinafter, the raw material film before the humidity conditioning process is sometimes referred to as a raw material film before the humidity conditioning process, and the raw material film after the humidity conditioning process is referred to as a raw material film after the humidity conditioning process.

The humidity control treatment by the humidity control furnace is to adjust the moisture content of the raw material film, so the humidity control furnace is filled with humidity control gas according to the temperature and humidity of the humidity control processing conditions. In order to adjust the water content of the raw film, the humidity control gas system may contain water vapor. When the water vapor contained in the humidity-controlling gas flows out of the humidity-controlling furnace and is condensed by cooling or the like, the outer wall surface of the opening for transport of the humidity-controlling furnace may cause condensation. The dew condensation water generated by the dew condensation adheres to the raw material film passing through the opening of the transport opening, and the raw material film may be contaminated.

In the above-mentioned optical film manufacturing device and optical film manufacturing method, by providing a condensation suppression device in at least one of the transport openings, water vapor contained in the humidity-controlling gas flowing out of the humidity-controlling furnace can condense, Condensation on the wall surface outside the opening for transportation is suppressed. Thereby, contamination of the raw material film caused by the dew condensation water adhering to the outer wall surface of the conveyance opening part and the raw material film adhered to the opening through the conveyance opening part is suppressed. Therefore, the dew condensation water adhering to the raw material film is dried, thereby suppressing appearance defects such as drying marks of the obtained optical film, and suppressing the warped state and optical characteristics of the obtained optical film. Adverse effects.

Hereinafter, preferred embodiments of the apparatus for manufacturing an optical film according to the present invention will be described with reference to the drawings.

    [First Embodiment]    

(Manufacturing device for optical film with suction device)

FIG. 1 is a side view schematically showing the vicinity of a humidity-controlling furnace of the optical film manufacturing apparatus 1. An optical film manufacturing device 1 is a device for manufacturing optical by applying a humidity control treatment to adjust a moisture content rate to a raw material film 5 that is continuously conveyed by unwinding a rolled body from which a long raw material film is wound. Thin film device. The arrow in FIG. 1 indicates the conveying direction of the raw material film 5.

The optical film manufacturing apparatus 1 includes the humidity control furnace 3 as shown in FIG. 1. The humidity control treatment of the raw film 5 is performed while the raw film 5 is being transferred in the humidity control furnace 3. In the humidity control furnace 3 shown in FIG. 1, there are two internal divisions, and the humidity control treatment can be performed in two stages. The humidity control furnace 3 is provided with a transfer opening 30 having an opening 31 for carrying the raw material film 5 into or out of the humidity control furnace 3. The opening 30 for conveyance refers to the area including the outer wall of the humidity control furnace 3 constituting the opening 31 and the periphery of the opening 31. The outer wall of the humidity control furnace 3 constituting the periphery of the opening 31 generally refers to within 1 m from the periphery of the opening 31 Outside the wall. The optical film manufacturing device 1 includes a suction device 7 as a dew condensation suppressing device for suppressing dew condensation on the outer wall surface of the opening 30 for transport of the humidity control furnace 3.

(Humidity Control Furnace)

The humidity control furnace 3 is a person who applies a humidity control treatment to the raw material film 5 while conveying the raw material film 5. For example, the moisture content of the raw material film 5 can be adjusted by the humidity control environment in the humidity control furnace 3. The moisture content of the raw material film 5 is adjusted by the humidity control treatment in the humidity control furnace 3, whereby the warped state and optical characteristics of the optical film can be adjusted to a desired state. The humidity-controlling environment in the humidity-controlling furnace 3 may be appropriately set according to the type of the raw material film and the humidity-controlling processing conditions. For example, in terms of humidity-controlling processing, when performing a humidification treatment, the temperature may be adjusted to 30 ° C to 80 ° C Humidity is 30RH% or more. Regarding the humidity control process, when the dehumidification process is performed, the temperature can be adjusted to 30 to 100 ° C and the humidity can be less than 30RH%.

The humidity control furnace 3 included in the optical film manufacturing apparatus 1 may be one, or may be two or more. In addition, the humidity control furnace 3 may have a single space, and according to the conditions of the humidity control treatment performed in the humidity control furnace 3, for example, as shown in FIG. 1, it may be divided into two or more and given two or more stages. The humidity conditioning processor.

The humidity-controlling furnace 3 can be adjusted to a humidity-adjusting environment according to the temperature and humidity of the humidity-conditioning processing conditions by filling the humidity-controlling gas in its internal space, thereby adjusting the moisture content of the raw material film 5 to a desired size . The humidity control furnace 3 may be provided with a humidifier (not shown) for setting the inside of the humidity control furnace 3 to a predetermined humidity control environment. The humidity controller can be used in accordance with the humidity control processing conditions. For example, by supplying the humidity control gas in the humidity control furnace 3, it can be adjusted to a humidity control environment according to the humidity control processing conditions in the humidity control furnace 3.

The humidity control furnace 3 may be a humidification furnace that performs a humidification process to increase the moisture content rate in the raw material film 5, or a dehumidification furnace that performs a dehumidification process that reduces the moisture content rate in the raw material film 5. The phenomenon that dew condensation occurs on the outer wall surface of the opening 30 for transportation due to the humidity-controlling gas flowing out of the humidity-controlling furnace 3 is easily generated when the humidity-controlling furnace 3 is a humidifying furnace. Therefore, the optical film manufacturing apparatus 1 of this embodiment is The wet furnace 3 is a humidifying furnace, and this humidifying furnace is particularly suitably used when performing a humidification treatment.

The humidity-controlling furnace 3 is provided with a transport opening 30 having an opening 31 for carrying the raw material film 5 before the humidity conditioning into the humidity-controlling furnace 3 or for carrying out the raw material film 5 after the humidity-conditioning. As shown in FIG. 1, the conveyance opening portion 30 may include a carry-in portion 30 a having a carry-in opening 31 a, and the carry-in opening 31 a may be used to carry the raw material film 5 before humidity conditioning into the humidity conditioning furnace 3. An opening; and a carrying-out portion 30b having a carrying-out opening 31b, the carrying-out opening 31b being an opening for carrying out the humidity-adjusted raw material film 5. The first figure shows an example in which each of the humidity control furnaces 3 has a carry-in portion 30a and a carry-out portion 30b, but the carry-in portion may also serve as a carry-out portion, for example, to transfer a plurality of raw material films in the humidity-controlling furnace 3. For example, it may have two or more carrying-in parts and carrying-out parts.

The humidity control furnace 3 may be provided with a plurality of guide rollers supporting the raw material film 5 to be conveyed. The plurality of guide rollers disposed in the humidity control furnace 3 include, for example, an upper roller 61 disposed on the upper side in the humidity control furnace 3 and the adjacent rollers disposed in the lower side in the humidity control furnace 3 as shown in FIG. 1. Lower roller 62 between upper roller 61. In this way, in each segment in the humidity control furnace 3, the raw material film 5 is alternately supported by the upper roller 61 and the lower roller 62, so that the raw material film 5 can be transported in a zigzag manner, and the raw material film in the humidity control furnace 3 can be increased. The conveying path of 5 can improve the humidity control efficiency, and the miniaturization of the humidity control furnace 3 can be achieved.

(Suction device)

The suction device 7 is a person who sucks the humidity-conditioning gas flowing out of the opening 31 of the conveyance opening portion 30 from the humidity-conditioning gas forming the humidity-conditioning environment in the humidity-conditioning furnace 3 and recovers it. The humidity-controlling gas system contains water vapor of a condensable component, so when it flows out of the humidity-controlling furnace 3 and cools, the water vapor will condense and easily cause condensation. The suction device 7 sucks the humidity-controlling gas flowing out of the humidity-controlling furnace 3 to reduce water vapor released to the atmosphere outside the humidity-controlling furnace 3 and suppress condensation on the wall surface outside the opening 30 for transport .

The suction device 7 may be provided in at least one of the transport openings 30 provided in the humidity control furnace 3, and as shown in FIG. 1, the suction device 7 may be provided in all the transport openings 30 in the humidity control furnace 3. The suction device 7 is, for example, a suction box. The suction box is, for example, a box shape whose overall shape is a rectangular parallelepiped, etc., one side of which has a plurality of through holes for sucking the humidity-controlling gas, and the other side having a hole for exhausting the humidity-conditioning gas sucked into the suction box. Vent.

Since the suction device 7 is for suppressing dew condensation on the outer wall surface of the conveyance opening 30, it is preferable to install the suction device 7 outside the humidity control furnace 3. In addition, in order to reduce the humidity-controlling gas released into the atmosphere outside the humidity-controlling furnace 3, the suction device 7 is preferably located on at least one of the upper side and the lower side of the film surface of the raw material film 5 along the conveyance The opening 31 of the opening portion 30 is provided, and it is preferable that the opening 31 has the same width as or wider than the width in the width direction of the raw material film. As shown in FIG. 1, the suction device 7 can be installed on both the upper side and the lower side of the film surface. However, when dew condensation occurs on the outer wall surface of the transport opening 30, the dew condensation water generated by the dew condensation will pass through itself. It may drop due to weight and may be attached to the raw material film 5 passing through the opening 31 of the conveyance opening 30. Therefore, the suction device 7 is preferably a raw material film disposed at the opening 31 passing through the conveying opening 30 of the humidity control furnace 3. At least the upper side of the film surface of 5.

The suction device 7 is provided with a heating unit for heating the humidity-controlling gas because the suction device 7 causes condensation to prevent condensation of water vapor in the humidity-controlling gas sucked into the suction device 7. Thereby, the humidity-controlling gas sucked into the suction device 7 is cooled, and the water vapor in the humidity-controlling gas will condense, which can suppress the generation of dew condensation in the suction device 7 and the contamination water from contaminating the raw material film 5 . As the heating section, a known heating device can be used, and examples thereof include a heater, a resistance heating element, an induction heating device, and a microwave irradiation device. The heating unit is preferably a temperature higher than the dew-point temperature of the humidity-controlling gas in the humidity-controlling furnace 3, and the heating-suction device 7 is preferred.

(Raw film and optical film)

The optical film manufactured by the optical film manufacturing apparatus 1 is obtained by subjecting a raw film to at least a humidity control treatment. The optical film may be, for example, a polarizing film, a protective film attached to a polarizing film, a polarizing plate with a protective film attached to one or both sides of a polarizing film, a retardation film, a brightening film, a reflective film, an anti-glare film, an anti-reflective film , Semi-transmissive reflective film, light diffusing film, and other films with optical functions used in image display devices. The raw material film is a raw material film used for producing such optical films, and it is at least one that has been subjected to a humidity control treatment.

The polarizing film is preferably a linear polarizer, and can be formed by adsorbing and aligning a dichroic dye such as iodine or a dichroic dye on a uniaxially stretched polyvinyl alcohol-based resin layer. Such a polarizing film can be produced, for example, by applying uniaxial stretching to a polyvinyl alcohol-based resin film, dyeing with a dichroic dye, boric acid treatment, and water washing treatment. When the optical film is a polarizing film, the humidity-controlling treatment is performed, for example, after adjusting the water content of the raw material film used to manufacture the polarizing film by heating and drying after performing the water washing treatment.

The protective film may be a simple protective film having no optical function, or a protective film having optical functions such as one of a retardation film and a brightness enhancement film. The material of the protective film is not particularly limited, and a translucent thermoplastic resin can be used. Examples of such thermoplastic resins include chain polyolefin resins such as polypropylene resins, cyclic polyolefin resins such as norbornene resins, and cellulose acetate based resins such as triethyl cellulose and diethyl cellulose. Resins; polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; polycarbonate resins; (meth) acrylic resins, etc. Thermoplastic resins well known in the art. The "(meth) acrylic acid" in this specification means at least one selected from acrylic acid and methacrylic acid. When the optical film is a protective film, the humidity control treatment is performed, for example, before bonding to the polarizing film, and is used to adjust the moisture content of the raw material film used for manufacturing the protective film.

When the optical film is a polarizing plate, the humidity control treatment is performed, for example, to adjust the moisture content of the laminated body in which the polarizing film and the protective film are bonded.

The thickness of the raw material film is not particularly limited. Generally, it is 1 μm or more, preferably 2 μm or more, and more preferably 5 μm or more. Usually, it is 200 μm or less, preferably 100 μm or less, and 50 μm or less. More preferably, it is more preferably 20 μm or less. When the thickness of the raw material film is as small as 1 μm or more and 20 μm or less, the raw material film having the suction device 7 is less likely to cause sticking and wrinkling of the raw material film when the raw material film is moved in or out of the humidity control furnace. Poor transportation such as folds and folds makes it suitable for use when a thin raw film is subjected to humidity control.

The thickness of the optical film obtained by subjecting the raw material film to at least humidity control is not particularly limited, but it is usually 1 μm or more and 200 μm or less. When the optical film is a polarizing film, the thickness is 5 μm or more and 30 μm or less. The optical film is a protective film. When the thickness is 10 μm or more and 80 μm or less, and when the optical film is a polarizing plate, the thickness is 30 μm or more and 200 μm or less.

(Manufacturing method of optical film using suction device)

The optical film manufacturing apparatus 1 shown in FIG. 1 is to continuously carry the raw material film 5 before humidity conditioning into the humidity conditioning furnace 3 from the carrying-in portion 30 a of the humidity conditioning furnace 3, and the material is applied in the humidity conditioning furnace 3. The humidity-conditioned raw material film after the humidity-conditioning treatment is carried out from the carrying-out portion 30 b of the humidity-conditioning furnace 3. At this time, the humidity-controlling furnace 3 is filled with humidity-controlling gas in accordance with the humidity-conditioning processing conditions, and the raw material film 5 before and after the humidity-conditioning is passed through the carrying-in portion 30a and the carrying-out portion 30b of the opening 30 for the humidity-controlling furnace 3 The opening 31a for carrying in and the opening 31b for carrying out. Therefore, the humidity-controlling gas in the humidity-controlling furnace 3 may flow out from the opening 31a for carrying in and the opening 31b for carrying out. Water vapor in the humidity-controlling gas flowing out of the humidity-controlling furnace 3 may condense depending on conditions such as temperature, humidity, and pressure outside the humidity-controlling furnace 3, and dew condensation may occur on the outer wall surface of the opening 30 for transportation.

In the optical film manufacturing apparatus 1, the suction device 7 provided in the transport opening 30 of the humidity control furnace 3 sucks and recovers the humidity-controlling gas flowing out of the humidity control furnace 3, and suppresses transportation Condensation suppression processing that causes condensation on the outer wall surface of the opening 30. Thereby, it is possible to prevent the dew condensation water adhering to the outer wall surface of the conveyance opening portion 30 from falling onto the material film 5 passing through the opening 31 of the conveyance opening portion 30 or the like to contaminate the material film 5. When the suction device 7 has a heating section, the heating section can perform a heating process for heating the humidity-controlled gas suctioned by the suction device 7. Thereby, condensation of water vapor in the humidity-controlled gas sucked by the suction device 7 can be suppressed, so that dew condensation adheres to the suction device 7, the contamination water can be prevented from contaminating the raw material film 5, and a good-quality optical film can be obtained .

The suction device 7 is provided outside the humidity control furnace 3 at least on the upper side of the film surface of the raw material film 5 along the opening 31 of the conveyance opening portion 30, thereby efficiently sucking as a cause of dew condensation. Humidifying gas containing water vapor. In particular, as described above, when the humidifying gas is supplied from the humidifier into the humidity control furnace 3, the pressure (internal pressure) in the humidity control furnace 3 is higher than the pressure (external pressure) outside the humidity control furnace 3, so the humidity control furnace The humidity-controlling gas system in 3 passes through the opening 31 of the opening 30 for conveyance to more easily flow out of the humidity-controlling furnace 3. Therefore, since a suction device is provided outside the humidity control furnace 3, the humidity control gas flowing out of the humidity control furnace 3 can be efficiently sucked. In addition, by providing the suction device 7 on the upper side of the film surface of the raw material film 5, it is possible to effectively suppress dew condensation on the outer wall surface located on the upper side of the film surface from the outer wall surface of the transport opening 30.

The suction pressure in the suction device 7 can be generally set to be 2.0 kPa or more and 5.0 kPa or less, and the flow velocity of the suction gas can be set to 5 m / s or more and 30 m / s or less.

    [Second Embodiment]    

(Manufacturing device for optical film with air supply device)

The device for manufacturing an optical film according to this embodiment is similar to the first embodiment in that the condensation suppressing device replaces the suction device 7 of the optical film manufacturing device 1 according to the first embodiment and includes an air supply device. different. Hereinafter, the same components as those described in the first embodiment will be omitted.

The optical film manufacturing apparatus 1 of this embodiment is provided with an air supply device as a dew condensation suppressing device for suppressing dew condensation on the wall surface outside the opening 30 for conveyance. The air supply device supplies air in a curtain shape to the opening 31 of the conveyance opening portion 30, thereby suppressing the outflow of the humidity-controlling gas from the humidity control furnace 3 and suppressing condensation on the wall surface outside the conveyance opening portion 30.

(Air supply device)

The air supply device supplies air in a curtain shape to the opening 31 of the conveyance opening 30, thereby suppressing the humidity-conditioning gas from flowing out of the humidity control furnace 3 from the opening 31 of the conveyance opening 30. Since the air supply device suppresses the flow of the humidity-controlling gas containing water vapor out of the humidity control furnace 3, the amount of water vapor released to the outside of the humidity control furnace is reduced, and it is possible to suppress the outside of the periphery of the opening 31 of the transport opening 30 Condensation on the wall. The air supply device may be installed in at least one of the transport openings 30 provided in the humidity control furnace 3, or may be installed in all the transport openings 30 in the humidity control furnace 3. The manufacturing apparatus of the optical film may include an air supply device and a suction device described in the first embodiment.

The air supply device is not particularly limited as long as it can supply air to the opening 31 of the conveyance opening portion 30 so as to form curtain-shaped air (curtain flow). For example, the air supply device can supply air from the upper side of the opening 31 to the lower side to form a curtain blow down method, or it can supply air from the left and right sides of the opening 31 to face each other to form a curtain blow horizontal blow method. . The curtain flow is preferably formed such that the opening 31 has the same width as or wider than the width of the raw material film. In addition, in order to avoid adversely affecting the transport of the raw material film 5 in the humidity control furnace 3, the curtain flow is preferably formed in the opening 31 formed in the transportation opening portion 30 outside the humidity control furnace 3.

The temperature of the air supplied by the air supply device is preferably higher than the temperature at which the water vapor of the condensable component in the humidity-controlling gas in the humidity-controlling furnace 3 will dew (the temperature of the humidity-controlling gas), usually 1 ° C to 50 ° C. By making the temperature of the air higher than the dew point temperature of the humidity-controlling gas, and suppressing the condensation of water vapor in the humidity-controlling gas by the air supplied from the air supply device, it is possible to prevent the condensation of dew on the wall surface outside the opening for transportation. The temperature of the supplied air usually needs to be 3 ° C or more higher than the dew point temperature of the humidity-controlling gas, and the humidity of the supplied air only needs to be 40% RH or less.

The blowing speed of the air supplied by the air supply device can be arbitrarily selected as long as it does not adversely affect the conveyance of the raw material film, and also depends on the size of the opening 31 of the conveyance opening 30 or the thickness of the raw material film 5 However, it is usually 2 m / sec or more, preferably 4 m / sec or more, usually 20 m / sec or less, and 15 m / sec or less.

(Manufacturing method of optical film using air supply device)

In the manufacturing apparatus of the optical film of this embodiment, similarly to the manufacturing apparatus 1 of the optical film shown in FIG. 1, the raw material film 5 before the humidity conditioning is continuously transferred from the humidity carrying furnace 3 into the carrying section 30 a to the humidity conditioning device. In the humidity furnace 3, the raw material film subjected to the humidity conditioning treatment in the humidity conditioning furnace 3 is carried out from the carrying-out portion 30b of the humidity conditioning furnace 3. At this time, the air supply device supplies air to the opening 31 of the transport opening 30 of the humidity control furnace 3 in a curtain shape, thereby performing a dew condensation suppressing process for suppressing condensation on the wall surface outside the transport opening 30.

The curtain-shaped air supplied by the air supply device reduces the amount of humidity-conditioning gas flowing out of the humidity-controlling furnace 3 to the outside of the humidity-controlling furnace 3, and reduces the water vapor flowing out of the humidity-controlling furnace 3 to the outside of the humidity-controlling furnace 3. The amount. As a result, dew condensation occurs on the outer wall surface of the opening 30 for transportation, and the dew condensation water generated by the dew drops falls on the raw material film 5 passing through the opening 31 of the opening 30 for transportation, and contamination of the raw material film 5 can be suppressed. Good quality optical film. In addition, by making the temperature of the air supplied from the air supply device higher than the dew point of the humidity-controlling gas, it is possible to suppress condensation of water vapor in the humidity-controlling gas, and it is possible to further suppress the condensation of dew condensation water on the outer wall surface of the transport opening 30.

As described above, when the humidifying gas is supplied from the humidifier into the humidifying furnace 3, the pressure (internal pressure) inside the humidifying furnace 3 becomes higher than the pressure (external pressure) outside the humidifying furnace 3, so the humidifying furnace 3 The humidity-controlling gas in the inside easily flows out of the humidity-controlling furnace 3 through the opening 31 of the conveyance opening 30.

Therefore, by providing an air supply device outside the humidity control furnace 3 and supplying curtain-shaped air to the opening 31 of the transport opening 30, it is possible to suppress the release of the humidity control gas that is likely to cause dew condensation to the outside of the humidity control furnace 3. Therefore, it is possible to suppress condensation on the opening 30 for transportation.

    [Third Embodiment]    

(Manufacturing device for optical film with heating device)

The device for manufacturing an optical film according to this embodiment is similar to that of the first embodiment in that the condensation suppressing device replaces the suction device 7 of the optical film manufacturing device 1 of the first embodiment, and includes a heating device. different. Hereinafter, the same components as those described in the first embodiment will be omitted.

The manufacturing apparatus of the optical film of this embodiment is provided with a heating device as a dew condensation suppressing device for suppressing dew condensation on the wall surface outside the opening for transportation. The heating device is a person who warms the outer wall surface of the opening 30 for conveyance, whereby the humidity-controlling gas flowing out of the humidity-controlling furnace 3 is cooled outside the humidity-controlling furnace 3 when the humidity-controlling gas flows out of the humidity-controlling furnace 3. By doing so, it is possible to prevent the water vapor in the humidity-controlling gas from forming dew condensation and adhering on the wall surface outside the transport opening 30.

(Heating device)

The heating device heats the outer wall surface of the opening 30 for transportation, and can prevent water vapor in the humidity-controlling gas flowing out of the humidity control furnace 3 from condensing on the outer wall surface of the opening 30 for transportation. By heating the outer wall surface of the opening 30 for transportation by the heating device, it is possible to suppress the water vapor flowing out of the humidity-controlling gas outside the humidity control furnace 3 from being cooled by the outer wall surface, and to suppress condensation on the opening 30 for transportation Outside wall surface. The heating device may be installed in at least one of the transport openings 30 provided in the humidity control furnace 3, or may be installed in all the transport openings 30 in the humidity control furnace 3. The optical film manufacturing device may include any one of a heating device, the suction device described in the first embodiment, the air supply device described in the second embodiment, or both. Person's device.

The heating device is not particularly limited as long as it can directly or indirectly warm the wall surface other than the opening 30 for conveyance, and a known heating device can be used. Examples of the heating device include a heater, a resistance heating element, an induction heating device, and a microwave irradiation device.

The heating device preferably heats the outer wall surface of the transport opening 30 to a temperature higher than the temperature at which the water vapor of the condensable component of the humidity-controlling gas in the humidity-controlling furnace 3 will condense (dew point temperature of the humidity-controlling gas). The outer wall surface of the transport opening 30 is heated to a temperature higher than the dew point temperature of the humidity-controlling gas by a heating device, thereby suppressing cooling of water vapor contained in the humidity-controlling gas on the outer wall surface and suppressing water vapor formation. Dew condensation adheres to the outer wall surface. The temperature of the outer wall surface generally needs only to be higher than the dew point temperature of the humidity-controlling gas by more than 3 ° C.

A manufacturing device for an optical film with a heating device. When the thickness of the raw material film is as small as 1 μm or more and 20 μm or less, the raw material film is unlikely to cause sticking and wrinkling when the raw material film is moved into or out of the humidity control furnace. Poor transportation such as pleating, folding, etc., can be used suitably when the humidity control of thin raw film is performed.

(Manufacturing method of optical film using heating device)

In the manufacturing apparatus of the optical film of this embodiment, similarly to the manufacturing apparatus 1 of the optical film shown in FIG. 1, the raw material film 5 before the humidity conditioning is continuously carried into the humidity conditioning furnace from the carrying-in portion 30a of the humidity conditioning furnace 3. In 3, the humidity-controlled raw material film 5 subjected to the humidity control treatment in the humidity control furnace 3 is carried out from the carrying-out portion 30b of the humidity control furnace 3. At this time, the outer wall surface of the transport opening 30 of the humidity control furnace 3 is heated by a heating device to perform a dew condensation suppressing process for suppressing dew condensation on the outer wall surface of the transport opening 30.

By heating the outer wall surface of the opening 30 for conveyance by the heating device, it is possible to prevent the water vapor contained in the humidity-controlling gas flowing out of the humidity control furnace 3 from being cooled on the outer wall surface. Thereby, it is possible to suppress that the water vapor contained in the humidity-controlling gas becomes dew condensation and adheres to the outer wall surface of the opening 30 for transportation, and a good-quality optical film can be obtained. In addition, by heating the outer wall surface of the opening 30 for transportation to a temperature higher than the dew point temperature of the humidity-controlling gas by the heating device, it is possible to prevent the water vapor flowing out of the humidity-controlling gas outside the humidity-controlling furnace 3 from being cooled and condensing. It is possible to further suppress dew condensation on the outer wall surface of the transport opening 30.

As described above, when the humidifying gas is supplied from the humidifier into the humidifying furnace 3, the pressure (internal pressure) in the humidifying furnace 3 is higher than the pressure (external pressure) outside the humidifying furnace 3, so the humidifying furnace 3 The humidity-controlling gas in the inside easily flows out of the humidity-controlling furnace 3 through the opening 31 of the transfer opening 30.

Therefore, the heating device heats the outer wall surface of the opening 30 for transportation, and the humidity-controlling gas that is likely to cause dew condensation can flow out of the humidity control furnace 3, and can also prevent the cooling of the outer wall surface of the opening 30 for transportation. It is possible to suppress dew condensation on the transport opening 30.

Claims (15)

    An optical film manufacturing device is a person who carries out humidity control to adjust the moisture content of the raw material film while conveying the raw material film, and has a humidity control furnace, which has more than one for carrying in or carrying out the foregoing The raw material film is provided with an opening for conveyance for opening, and is used to perform the humidity control process; and a dew condensation suppressing device, for suppressing dew condensation on the wall surface outside the opening for conveyance, and the dew condensation suppressing device is provided in at least one The transport opening.         The device for manufacturing an optical film according to item 1 of the scope of the patent application, wherein the humidity control furnace is a humidification furnace that performs a humidification treatment on the raw material film.         The device for manufacturing an optical film according to item 1 or 2 of the scope of application for a patent, wherein the dew condensation suppressing device is at least one of the following: a suction device for sucking from the opening portion of the conveyance Humidity-controlling gas in the humidity-controlling furnace flowing out of the opening; air supply means for supplying air to the opening of the opening portion for conveyance in a curtain shape; and heating means for heating the conveyance device The aforementioned outer wall surface of the opening.         The device for manufacturing an optical film according to item 3 of the scope of patent application, wherein the dew condensation suppressing device is the suction device, the suction device is outside the humidity control furnace, and is connected to the opening through the transport opening. At least the upper side of the film surface of the raw material film in the opening is provided along the opening.         The device for manufacturing an optical film according to item 3 or 4 of the scope of patent application, wherein the dew condensation suppressing device is the aforementioned suction device, and the aforementioned suction device is a suction box.         The device for manufacturing an optical film according to any one of claims 3 to 5, wherein the dew condensation suppressing device is the aforementioned suction device, and the aforementioned suction device further has the aforementioned adjustment for heating the suctioned Wet gas heating section.         The device for manufacturing an optical film according to item 3 of the scope of patent application, wherein the dew condensation suppressing device is the air supply device, and the temperature of the air supplied by the air supply device is higher than the dew point temperature of the humidity-controlling gas. .         An optical film manufacturing method includes carrying out a humidity-conditioning process for adjusting a moisture content rate of the raw material film while conveying the raw material film, and the humidity-conditioning process is performed in a humidity-conditioning oven having one or more openings for conveyance. The conveyance opening is provided with an opening for carrying in or out the raw material film, and at least one of the conveyance openings is subjected to dew condensation suppression processing for suppressing dew condensation on a wall surface outside the conveyance openings.         The method for manufacturing an optical film according to item 8 of the scope of patent application, wherein the aforementioned humidity-conditioning treatment is a humidification treatment.         The method for manufacturing an optical film according to item 8 or 9 of the scope of patent application, wherein the dew condensation suppression treatment is at least one of the following: a suction treatment, which sucks the opening from the opening for transportation. The humidity-controlling gas flowing out of the humidity-controlling furnace; the air supply process is to supply air to the transport openings in a curtain shape; and the heating process is to heat the outer wall surfaces of the transport openings.         The method for manufacturing an optical film according to item 10 of the scope of the patent application, wherein the condensation prevention treatment is at least one of the suction treatment and the heating treatment, and the thickness of the raw material film is 1 μm or more and 200 μm or less. .         The method for manufacturing an optical film according to item 10 or 11 of the scope of the patent application, wherein the dew condensation suppression process is the aforementioned suction process, and the aforementioned suction process is external to the humidity control furnace and is transported through the aforementioned The humidity-controlling gas is sucked along at least the upper side of the film surface of the raw material film in the opening portion along the opening.         The method for manufacturing an optical film according to any one of claims 10 to 12, in which the aforementioned dew condensation suppression treatment is the aforementioned suction treatment, and then the aforementioned humidity-conditioning gas after being sucked by the aforementioned suction treatment is heated. Of heat treatment.         The method for manufacturing an optical film according to item 10 of the scope of the patent application, wherein the condensation prevention process is the aforementioned air supply process, and the temperature of the aforementioned air supplied in the aforementioned air supply process is higher than that in the humidity control furnace. The temperature of the dew point temperature of the humidity control gas.         The method for manufacturing an optical film according to any one of claims 8 to 14, in which the aforementioned optical film is a polarizing film, a protective film attached to the aforementioned polarizing film, and one or both sides of the aforementioned polarizing film Any of the polarizing plates obtained by bonding the protective film.