TW202114848A - Film roll and method for manufacturing the same provide excellence in blocking resistance and winding offset resistance - Google Patents

Abstract

The purpose of the invention is to provide a film roll having excellence in blocking resistance and winding offset resistance even if the film with thin-film like at a low elastic modulus, and a method for manufacturing the same. The solution of the invention is a film roll having knurled machining portions on at least two ends in the short-side direction of the film. It is characterized in that the knurled machining portion is a portion A, and the portion on the back side of the film opposite to the portion A is a portion B, and the film surface that is not machined with knurling other than the portion A and the portion B is the surface C. When the coefficients of static friction in the portion A and the portion B are respectively designated as a and b. the following relational expressions (1) and (2) will be satisfied: Formula (1) coefficients of static friction between surfaces C are smaller than the coefficients of static friction between the portion A and the portion B. The formula (2) is that a is smaller than b.

Description

Film roll and its manufacturing method

The present invention relates to a film roll and its manufacturing method. More specifically, it relates to a film roll having excellent blocking resistance and winding offset resistance even if it is a low elastic modulus and film-like film. Production method.

Generally speaking, a liquid crystal display device is provided with a film containing various thermoplastic resins (hereinafter also referred to as a thermoplastic resin film).

The above-mentioned film for general polarizing plate use is supplied as a roll of a long and wide film, that is, a so-called film roll. For such film rolls, due to uneven film thickness, film adhesion may occur, or winding deviation may occur due to impact or the like.

As a means to solve such problems, for example, Patent Document 1 discloses that by attaching a film called a protective film to an optical film, the adhesion of the optical film is prevented, and the apparent thickness is increased to prevent winding deviation. Move the technology. However, this technique requires a step of bonding the protective film and the optical film and a step of peeling during use, and the productivity is not high.

Therefore, as another means to prevent sticking and winding deviation with good productivity, for example, Patent Document 2 discloses that by knurling the end of the film and then winding, the prevention of sticking and winding can be obtained. Offset film roll technology.

However, in recent years, film systems for polarizing plate applications are required to be larger and thinner. In addition, it is expected that the protective film for protecting the polarizing plate and the retardation film for adjusting the retardation will not change the physical or optical properties due to environmental changes. In the past, cellulose materials such as triacetyl cellulose (commonly known as TAC) were used. It is a main body, but a film containing a material excellent in water resistance, such as a cyclic olefin resin or an acrylic resin, is initially used as the aforementioned protective film or retardation film. Furthermore, there is a strong demand for making the film into a thin film and making the polarizing plate thin. However, a film with a low elastic modulus and a thin film containing the aforementioned cyclic olefin resin or acrylic resin must have a low winding tension, and as a result, it is easy to become Soft winding tends to cause winding deviation.

Under such circumstances, it has become a very difficult technology to make the film used in the liquid crystal display device into a film roll system with a wide width and a long strip. The knurling process alone cannot solve the adhesion or The status of the winding offset problem. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2019-61031 [Patent Document 2] Japanese Patent No. 5266611

[The problem to be solved by the invention]

The present invention was made in view of the above-mentioned problems/conditions, and the problem to be solved is to provide a film roll having excellent blocking resistance and winding offset resistance even if it is a thin film with a low elastic modulus, and a method of manufacturing the same. [Means to solve the problem]

In order to solve the above-mentioned problems, the inventors of the present invention found that by controlling at least the static friction of the knurled part at both ends of the film and the part on the back of the film facing the knurled part during the process of investigating the causes of the above-mentioned problems, etc. When it becomes a film roll, it will increase the frictional force of the knurled part where the films are in contact with each other, thereby suppressing the occurrence of adhesion and winding deviation, and obtain a film with a low elastic modulus and a film with a resistance to adhesion And the film roll and its manufacturing method with excellent resistance to winding deviation.

That is, the above-mentioned problems of the present invention are solved by the following means.

1. A film roll, which is a film roll with knurled processing parts on at least both ends of the short side direction of the film, characterized by Take the aforementioned knurled part as part A, the part on the back side of the film opposite to this part A as part B, and the unknurled film surface other than this part A and part B as surface C, and When the static friction coefficients of part A and part B are a and b respectively, Satisfy the following relations (1) and (2); Equation (1) The coefficient of static friction between surfaces C<the coefficient of static friction between part A and part B, Formula (2) a<b.

2. For the film roll of item 1, where the aforementioned a and b satisfy the following relationship (3); Formula (3) 0.3<a/b<0.8.

3. Such as the film roll of item 1 or 2, in which the short side length of the aforementioned film is in the range of 1.3~3.0m.

4. The film roll of any one of items 1 to 3, wherein the film thickness of the aforementioned film is within the range of 10~45μm.

5. The film roll according to any one of items 1 to 4, wherein the aforementioned film contains a cyclic olefin resin or an acrylic resin.

6. A method for manufacturing a film roll, which is a method for manufacturing a film roll such as the film roll of any one of items 1 to 5, characterized in that it has at least the aforementioned part A or the aforementioned part B surface Steps of upgrading treatment.

7. The film roll manufacturing method described in item 6, in which only the aforementioned part B is subjected to the aforementioned surface modification treatment.

8. The film roll manufacturing method according to item 6, wherein the aforementioned surface modification treatment is performed on both the aforementioned part A and the aforementioned part B.

9. The method for manufacturing a film roll according to any one of items 6 to 8, wherein the knurled portion is formed by laser knurling. [Effects of Invention]

By the above-mentioned means of the present invention, it is possible to provide a film roll and a manufacturing method thereof that are excellent in blocking resistance and winding offset resistance even if it is a thin film with a low elastic modulus.

Although the exhibiting mechanism or action mechanism of the effect of the present invention is not clear, it is estimated as follows.

As a result of the in-depth study of the above-mentioned problems, the present invention combines a part of the film, specifically the knurled part (part A) at both ends, and the part (part A) on the back side of the film facing the knurled part. B), and the respective static friction coefficients of the film surface (surface C) without knurling processing other than the part A and part B, are controlled to satisfy the relational expressions (1) and (2). The friction force of the knurled part where the films are in contact with each other is higher than the film surface C. It is inferred that even a film with a low elastic modulus and a thin film can suppress the occurrence of adhesion and winding deviation more than the method of forming only the knurled part.

The film roll of the present invention is a film roll having knurled parts on at least both ends in the short-side direction of the film, and is characterized in that the knurled part is the part A, and the back side of the film opposite to the part A When the part is part B, the unknurled film surface other than part A and part B is surface C, and the static friction coefficients of part A and part B are respectively a and b, the aforementioned relational expressions (1) and (2). This feature is a technical feature common to or corresponding to the following implementation aspects.

As an embodiment of the present invention, from the viewpoint of demonstrating the effect of the present invention, the aforementioned a and b satisfy the aforementioned relational expression (3), and the viewpoint of preventing the winding deviation of the film roll with larger area and thin film It is a preferable range.

In addition, the short side length of the aforementioned film is in the range of 1.3 to 3.0 m, or the film thickness of the aforementioned film is in the range of 10 to 45 μm, to provide a film corresponding to the use of large-area and thin-film polarizers. It is better from a viewpoint.

The above-mentioned film system contains a cyclic olefin resin or an acrylic resin, and is preferable from the viewpoint of suppressing changes in physical properties or optical properties due to environmental changes as a protective film and retardation film for protecting the polarizing plate.

The method for manufacturing the film roll of the present invention is characterized in that it has a step of surface-modifying at least the part A of the knurled part and the part B of the part on the back side of the film opposite to the part A .

Moreover, it is preferable to perform the said surface modification process on the said part B only from a viewpoint of manufacturing a film roll with good productivity.

In addition, it is a preferable manufacturing method from the viewpoint of further improving the static friction coefficient that the surface modification treatment is performed on both the part A and the part B.

Furthermore, forming the knurled portion by laser knurling processing is a preferable manufacturing method from the viewpoint of preventing film breakage when the convex portion is formed even in a thin-film thermoplastic resin film .

Hereinafter, the present invention, its constituent elements, and forms/aspects for implementing the present invention will be described in detail. Furthermore, in this case, "~" is used to include the numerical values described before and after it as the lower limit and the upper limit.

≪Outline of the film roll of the present invention≫ The film roll of the present invention is a film roll having knurled parts on at least both ends in the short-side direction of the film, and is characterized in that the knurled part is the part A, and the back side of the film opposite to the part A When the part is part B, the unknurled film surface other than part A and part B is surface C, and the static friction coefficients of part A and part B are respectively a and b, the following relational expression (1 ) And (2). Equation (1) The coefficient of static friction between surfaces C<the coefficient of static friction between part A and part B, Formula (2) a<b.

The feature of the present invention is that a part of the film, specifically the knurled part A at both ends, and the part B on the back of the film facing the knurled part, and other parts A and B The coefficient of static friction of the film surface C that has not been knurled is controlled to satisfy the above relational expressions (1) and (2). When the film roll is formed, the friction force of the knurled portion where the films are in contact with each other can be higher than that of the film surface C, to suppress the occurrence of adhesion and winding deviation.

In the present invention, in order to control the aforementioned static friction coefficient, it is preferable to perform a surface modification treatment on at least the part A of the knurled part or the part B on the back side of the film opposite to the part A. The surface modification treatment used here is to impart the static friction coefficients of the respective parts A and B so as to satisfy the aforementioned relational expressions (1) and (2).

It is generally known that the "surface modification treatment" is applied to the film to improve the adhesion between the coating material and the film before coating, or to increase the adhesion between the functional layers when laminating functional layers, etc. And endowed technology. However, when this technology is applied to the manufacture of film rolls, the surfaces of the films are easy to adhere to each other, causing adhesion, etc., so it is difficult to directly apply to the manufacture of film rolls.

In the present invention, the film surface C other than the part A of the knurled part and the part B on the back side of the film opposite to the part A is not subjected to the surface modification treatment, so the main part of the film will not be affected. The adhesiveness of surface C is affected, and the above-mentioned "adhesion caused by adhesion" can be avoided.

Generally, it is known that the frictional force of a film depends on the cohesive force (bonding force) between the real contact area and the object, and also depends on how much the film is in contact with the object. The knurling has a convex shape, and the area of the convex portion is generally 5% or less relative to the film surface, so the actual contact area is small. Therefore, it is known that the frictional force is worse than that of the film surface C.

In the present invention, it is preferable that at least the part A of the knurled part or the part B of the part on the back side of the film facing the part A be subjected to a surface modification treatment in order to increase the coefficient of static friction. Through this surface modification treatment, the cohesive force (bonding force) is higher than that of the other film surface C, thereby increasing the frictional force of the knurled part in the film roll, and as a result, it can be formed without causing adhesion or Winding the offset film roll.

The "static friction coefficient" of the present invention is measured by, for example, a static friction tester (Toyo Seiki FRICTION TESTER TR).

In the aforementioned relational expression (1) of the present invention, the static friction coefficient between the surfaces C and the static friction coefficient between the part A and the part B are measured by the following method.

Measurement conditions: Use the film (knurled part (part A), the part on the back side of the film facing the part A (part B), and the non-knurled part (surface C)), and place the surfaces C between each other and the part The coefficient of static friction between part A and part B is superimposed on the respective parts, and the static friction coefficient is measured ^{with the load of 0.166g/mm 2} , 0.83g/mm ² , and 1.66g/mm ^{2 respectively.} The value is the average value of the static friction coefficient of the above 3 loads.

In addition, in relational expression (2), it is assumed that the static friction coefficient between the knurled parts (part A) is a, and the static friction between the parts (part B) on the back side of the film facing the part A When the coefficient is b and measured separately, the relationship between a and b is displayed. By making the static friction coefficient b of the part B higher than the static friction coefficient a of the part A, the friction force can be expected to increase.

The relationship between a and b further satisfies the following relational expression (3), and it is preferable from the viewpoint of preventing deviation of the winding of the film roll that has been increased in area and thinner.

Formula (3) 0.3＜a/b＜0.8 In the formula (3), when it is greater than 0.3, the friction coefficient a of the knurled part becomes larger, so winding deviation is less likely to occur. When the friction coefficients of part A and part B are significantly different, they are easily affected by the surface with a small friction coefficient. Therefore, by making the value of the friction coefficient a of part A moderate, it is not easy to make the difference between the friction coefficient of part A and part B It becomes too large to cause winding deviation.

Moreover, when it is less than 0.8, the friction coefficient b of the part B on the back side of the film facing the part A will not be too small, the occurrence of adhesion around the knurled part is suppressed, and the effect of improving the adhesion resistance is easily maintained.

[1] Knurling processing department The knurled processing part of the present invention refers to a part having knurls on at least both ends of the short side direction of the film. The film is divided into part A of the aforementioned knurled part, part B of the part opposite to the part A on the back side of the film, and part A and the surface C of the film surface that is not knurled other than part B. .

Here, the "opposite part" refers to the part on the back side of the film that is symmetrical to the film via the part A when the knurled part on the film surface side is used as part A.

＜Knurling processing＞ Fig. 1 is a schematic view showing a cross section of a film roll wound after knurling processing and preferably surface modification processing.

In FIG. 1( a ), the film 1 formed into a film is wound and rotated by a near roll 2 and a touch roll 3, and is wound as a film roll 10. Part A is a knurled processing part, which is formed by knurling processing means not shown in the figure. The part B is the part on the back side of the film facing the part A. In the case of (a), it is preferable that the part is surface-modified in order to control the static friction coefficient.

The part B is preferably within a range of 50 to 120% of the width of the knurled portion (part A) of the knurled part (part A), and is surface-modified in order to control the coefficient of static friction. It is more preferably in the range of 80 to 120%, more preferably in the range of 90 to 110%, and particularly preferably in the range of 100 to 110%.

The width of the part B subjected to the surface modification treatment is long. If the width of the knurled part (part A) is more than 50%, the effect of the present invention can be effectively exhibited, and if it is within 120%, it contains Deviations in production can demonstrate the effects of the present invention.

Fig. 1(b) is a perspective view showing a film roll having a knurled part A and a part B on the back side of the film facing the part A.

The film roll 10 of the present invention is a film roll having knurled parts (part A) at least at both ends in the short-side direction of the film, and at least the knurled part (part A) and the film opposite to it The part on the back side (part B) is preferably subjected to surface modification treatment in order to control the coefficient of static friction. Therefore, as an embodiment of the present invention, there are (1) only the knurled part (part A) is provided with surface modification treatment, and (2) only the knurled part (part A) is paired with The aspect of applying surface modification treatment to the part on the back side of the film (part B), and (3) to both the knurled part (part A) and the part on the opposite side of the film (part B) The state of surface modification treatment.

Here, "knurling processing" means "so-called roll processing in which uneven portions are formed on the film surface". In the past, there have been multiple methods of knurling. Roughly there are the "heating press method" in which a metal roll with a convex shape (also called an embossing ring) is heated while pressing it, and the film is selectively applied by a laser or the like. Both the "laser method" that will absorb the wavelength to heat it to deform it. In addition, in the "heat pressing method", by changing the material of the opposed roller (usually referred to as the rear roller), the shape of the aforementioned convex portion is changed.

Figure 2 is a conceptual diagram illustrating various methods of knurling.

Fig. 2(a) is a schematic diagram showing the "heat pressing method" in which the embossing ring 4 having a convex shape formed on the metal roller is pressed against the metal roller while the metal roller is heated. The rear roller is the metal roller 5. Case. By making the back roll of metal, the stress generated when the embossing ring 4 is pressed into the film 1 is directed toward the inside of the film and the periphery of the embossing ring, forming a convex portion (knurling) 8 in the shape shown in Figure 2(b) .

The "knurled part" referred to in the present invention refers to a part that has been given (formed) the shape of the aforementioned convex part.

The aforementioned heating temperature is preferably selected from a temperature range above the glass transition point of the thermoplastic resin and below the melting point.

In addition, the embossing ring 4 is made of carbon steel, stainless steel, ceramic coating and HCr plating, etc. The material is not particularly limited. The width of the protrusion forming part is about 5-30mm, and the shape of the marking is that the distance between the protrusions is in the short-side direction. The length direction is about 0.5~5mm, and the height of the protrusions is about 0.3~3mm. However, the width of the ring, the spacing of the protrusions, and the height can be selected as required.

FIG. 2(c) shows the aforementioned "heat pressing method", but the rear roller is the rubber roller 6. By making the back roll of rubber, the stress generated when the embossing ring 4 is pressed into the film 1 is directed toward the rubber roll side to form a convex portion (knurling) on the back side of the film in the shape shown in Figure 2(d) 8.

Fig. 2(e) is the aforementioned "laser method". The film at the part irradiated with the laser light 7 is thermally deformed, and a convex portion (knurling) 8 is formed in the shape of Fig. 2(f).

The knurling process of the present invention is preferably a laser method from the viewpoint of ease of forming and prevention of breakage.

In the laser method, when the thermoplastic resin film is irradiated with laser light, the thermoplastic resin film is locally thermally melted or ablated at the point irradiated with the laser light. Therefore, a cavity is formed at the location irradiated by the laser light, and the cavity becomes the center of the convex portion. In addition, part or all of the material of the thermoplastic resin film that is irradiated with the laser light is fluidized, so that a protrusion is formed around the point where the laser light is irradiated, and the protrusion becomes the convex part. Zhou Department. If the convex-shaped part is formed by laser light in this way, even for a thermoplastic resin film with a thin film thickness, it is possible to prevent the thermoplastic resin film from breaking when the convex-shaped part is formed. In addition, even if the thermoplastic resin film is bent, it is difficult to break the convex portion. This presumption is due to the fact that, for example, compared with embossing processing, when the convex portion is formed by laser light, unnecessary pressure is not applied to the thermoplastic resin film, and residual stress is not likely to be left on the thermoplastic resin film.

The present invention preferably adopts a laser method. However, although the convex shape portion is formed by the laser method, it is stable, but on the other hand, there is a tendency that the convex shape portion has a small forming area and therefore the friction force is low. However, by using the surface modification treatment of the present invention, the frictional force of the knurled part is increased while maintaining the stable convex shape, and a film with high gauge band resistance and winding deviation resistance can be obtained. volume. Here, "violent tendons" are also called "black bands", which means that when the film becomes a film roll, the thickness of the film increases due to the deviation of the film thickness of the film or the adhesion between the films. Part of the part that looks dark visually.

For the knurled part, when the film is provided with a concavo-convex structure including convex-shaped parts on both ends of the film in the short-side direction for the purpose of improving the handling of the film, the width of the concavo-convex structure area is preferably 2mm or more, more preferably 4 mm or more, particularly preferably 5 mm or more, more preferably 100 mm or less, more preferably 80 mm or less, particularly preferably 60 mm or less.

The height h (μm) of the knurled part is preferably set in the range of 0.05 to 0.3 times the thickness H of the film, and the width W is preferably set in the range of 0.005 to 0.02 times the width L of the film.

At this time, the height of the knurled part, from the film surface, is usually preferably in the range of 1.5 to 30 μm on average, and more preferably in the range of 2 to 20 μm.

In addition, the knurled part may be formed on both sides of the film. At this time, the height h1+h2 (μm) of the knurled part on both sides is preferably set to the range of 0.05 to 0.3 times the film thickness H, and the width W is preferably set to 0.005 to 0.02 times the film width L range. For example, when the film thickness of the film is 40 μm, the height h1+h2 (μm) of the knurled part is preferably set in the range of 2-12 μm, and the width of the knurled part is preferably set in the range of 5-30 mm.

The shape of the aforementioned concavo-convex structure and the arrangement in the concavo-convex structure area can be any shape and arrangement according to the purpose of use. By controlling the trajectory of irradiating the laser light on the film surface, the concave-convex structure of the desired shape can be drawn with the laser light. Examples of the shape of individual concavo-convex structures (the shape when viewed from a direction perpendicular to the film surface) include point-like shapes, linear shapes, circular shapes, elliptical shapes, polygonal shapes, etc. . The arrangement of the concavo-convex structure may be, for example, an arrangement having a certain regularity along the length direction and the short side direction of the film, or a random arrangement.

The laser device used in the present invention can use various forms used in film processing. Examples of laser devices used include ArF excimer laser devices, KrF excimer laser devices, XeCl excimer laser devices, YAG laser devices (especially the third harmonic or the fourth harmonic Harmonic), YLF or YVO ₄ solid laser device (especially the third harmonic or the fourth harmonic), Ti:S laser device, semiconductor laser device, fiber laser device, and carbonic acid Gas laser device. Among these laser devices, the price is relatively cheap and the output suitable for film processing can be obtained efficiently, and the carbon dioxide laser device is particularly preferred.

The center wavelength of the wavelength range of the laser light in laser irradiation is not particularly limited, and can be any wavelength used in film processing. For example, laser light with a center wavelength of any value in the range of 9~12μm can be used. Especially when using a carbon dioxide laser device as a laser device, you can use laser light with a center wavelength including a wavelength near 10.6μm (for example, 10.5~10.7μm), and a center wavelength including a wavelength near 9.3μm (for example, 9.2~9.4μm). ) Laser light, especially when a laser light containing a wavelength of 9.3 μm is used, the knurling formation of a film containing a hydrocarbon polymer can be performed particularly well.

The output of the laser light is preferably 1W or more, more preferably 5W or more, and more preferably 15W or more; preferably 120W or less, more preferably 100W or less, more preferably 80W or less, and even more preferably 70W or less .

According to the knurling process using the laser method, it is possible to produce a film with a concave-convex structure with little variation in height of the concave-convex structure. The height of the uneven structure refers to the difference between the highest part of the uneven structure formed on the film surface and the height of the film surface. The height of the uneven structure can be measured using an interference-type surface profile measuring device ("NewView7200" manufactured by ZYGO). For example, in the case of winding as a film roll, the fluctuation of the height of the concavo-convex structure is preferably ±20% or less, more preferably ±15% or less. By making the variation of the height of the concavo-convex structure to such a low value, it is possible to effectively reduce the occurrence and adhesion of the scratches caused by the friction between the films in the film roll.

＜Preferable specific example of knurling processing using laser method＞ Carbon dioxide laser device: The output of the laser device is 20W, the center wavelength of the output wavelength is 10.59μm, and the range of the output wavelength is adjusted to less than ±0.01μm with the center wavelength as the center.

The formation of the knurled processing section: the width of the uneven area is adjusted to 15mm, and the linear speed of the film is adjusted to 10m/min.

The laser irradiates the film by reflecting the parallelized beam of light emitted by the carbon dioxide laser device with two galvano mirrors, passing the fθ lens (focus distance 200mm), and condensing it on the transport The surface of the film can be carried out. By controlling the angle of the galvanometer mirror, the light collection position is moved in the direction of the film plane, thereby controlling the trajectory of the laser light on the film surface.

The trajectory of the laser light is controlled to draw a large number of circles in the uneven area of the film surface, thereby forming an uneven structure corresponding to the shape of the circle. The diameter of the individual circles was set to 2.5 mm, and the circles were arranged in a concave-convex area with a width of 15 mm and formed in 5 rows extending in the longitudinal direction of the film. By irradiating the laser light, the speed of forming the uneven structure is adjusted to form an uneven structure with a height of about 10 μm, which can become the knurled part of the present invention.

＜Surface modification treatment＞ In the present invention, it is preferable that at least the part A of the knurled part or the part B of the part on the back side of the film facing the part A be subjected to a surface modification treatment in order to control the coefficient of static friction.

The surface modification treatment of the present invention means that the energy on the surface of the film, the so-called surface energy, is activated. If activated, an effect can be expected. For example, if it is plasma treatment or corona treatment, activation can be easily performed, and only a desired part can be modified. For example, the surface of the film can be modified by a method such as chemical treatment or polishing. By increasing the surface energy, when it becomes a film roll, the friction force with the film is increased, and the winding deviation can be prevented. In the present invention, "surface energy activation" means that the surface is close to hydrophilic, that is, it is defined as a surface free energy increase of 10 mJ/m ² or more before and after the surface modification treatment.

In the present invention, the surface modification is preferably performed by plasma treatment. In the case of plasma treatment, it is easy to treat only a part of the short side of the film. In addition, since the energy for activation is high, it can be used even in a state where the processing time is short. The processing time varies from film to film, so it is necessary to set an appropriate processing time according to the type of film.

Corona treatment can be used for surface modification, but it will be affected by electrification, so it is also necessary to carry out the de-energizing step together.

Surface modification treatment is performed, at least as mentioned above, in which only the knurled part (part A) is given surface modification treatment, and only the knurled part (part A) and the opposite film The part on the back side (part B) is given surface modification treatment, and the knurled part (part A) and the part on the opposite side of the film (part B) are given surface modification treatment. kind. Among them, from the viewpoint of the installation and effect of the device, it is particularly preferable to apply a surface modification treatment to only the part on the back side of the film (part B), and to apply the knurled part (part A) and the opposite film Both of the parts on the back side (part B) are given a state of surface modification treatment.

Specific surface modification treatment methods include corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, saponification treatment, glow treatment, ozone treatment, electron beam treatment, and the like. Especially from the viewpoint of productivity, corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, and saponification treatment are preferred; plasma treatment is particularly preferred.

Corona treatment or plasma treatment is a treatment for discharging the surface of the film to impart functional groups (such as carboxyl groups, hydroxyl groups, acrylic groups, amide groups, etc.) to improve the wettability of the film surface. Corona treatment is usually carried out under atmospheric pressure (in air). Plasma treatment is usually carried out under an environment of nitrogen, helium, neon, argon, xenon, carbon dioxide, nitrous oxide, hydrogen, ammonia, etc., or under atmospheric pressure. The "Atmospheric Pressure Plasma Treatment" carried out.

"Corona discharge treatment" refers to the application of high-frequency/high voltage between a dielectric and an insulating electrode to generate a corona, so that the substrate film passes between the dielectric and the electrode, thereby treating the surface of the substrate film method. Thereby, the adhesiveness of the surface of the base film improves. Examples of electrode materials include ceramic and aluminum. The distance between the electrode and the dielectric is preferably 1 to 5 mm, more preferably 1 to 3 mm.

The corona output intensity is preferably 0.2 to 3 kW, more preferably 0.5 to 1.5 kW. By setting the corona output intensity to 0.2 or more, the corona discharge is stabilized, and a stable adhesive force can be easily provided to the surface of the film. By making the corona output intensity below 2.0kW, the membrane is not easily damaged. The amount of electron exposure in corona discharge treatment can be 100~1000W/m ² ･min.

"Plasma treatment" is a treatment that activates the membrane surface by performing plasma discharge under a gas environment such as inert gas or oxygen generated under reduced pressure or atmospheric pressure. In order to produce efficiently under conveyance using rollers, plasma treatment under atmospheric pressure is preferred.

Plasma treatment can modify the surface of the substrate layer in various ways by changing the types of gases. Therefore, when activating the surface of the substrate layer, the type of gas can be appropriately selected arbitrarily. Examples of gas types include fluorine compounds such as nitrogen, oxygen, argon, helium, acrylic acid, hydroxyalkyl, CF ₄ , CHF ₃ C ₂ F _{6 and the like.}

The plasma output is preferably 0.2~3kW. The linear velocity (moving speed) is preferably 3 to 70 m/min, more preferably 3 to 50 m/min. The frequency is preferably 3 to 30 kHz, more preferably 5 to 20 kHz.

The specific conditions of plasma treatment are to use an atmospheric pressure plasma irradiation device, and the film is passed under the atmospheric pressure plasma irradiation device to perform the atmospheric pressure plasma irradiation treatment.

The following shows the composition of the mixed gas (reactive gas) used in the atmospheric pressure slurry treatment as an example. Furthermore, the air pressure is 1.013×10 ⁵ Pa. Nitrogen: 99.98 vol% Oxygen: 0.02 vol% Mixed gas flow rate: 2m ³ /min

Ultraviolet rays in "ultraviolet treatment" generally refer to electromagnetic waves with a wavelength of 10 to 400 nm. In the case of ultraviolet radiation treatment, it is preferable to use ultraviolet rays of 210 to 375 nm.

The irradiation of ultraviolet rays is better than the range where the film to be irradiated is not damaged, and the irradiation intensity or irradiation time is set.

Ultraviolet radiation can be suitable for batch processing or continuous processing, and can be appropriately selected according to the shape of the substrate or support used. For example, devices such as UV ozone cleaner UV-1 made by SAMCO, ultraviolet sintering furnace made by Eye Graphics Co., Ltd. can be used. Although the time required for ultraviolet irradiation varies depending on the substrate or the composition and concentration of the substrate or barrier layer used, it is generally 0.1 seconds to 60 minutes, preferably 0.5 seconds to 30 minutes.

"Saponification" is generally performed by immersing in a sodium hydroxide solution of a certain temperature and a certain concentration for a certain period of time. For example, the optical film of the present invention is immersed in a 2mol/L sodium hydroxide solution at 60°C for 90 seconds.

[2] Film roll The film roll referred to in the present invention refers to a film wound in a roll shape.

[2.1] Thermoplastic resin The thermoplastic resin material used for the film of the present invention is not limited by the operator as long as it can be used as a film roll after film formation. For example, as a thermoplastic resin used for polarizing plates, cellulose ester resins such as triacetyl cellulose (TAC), cellulose acetate propionate (CAP), and diacetyl cellulose (DAC) can be used. Or cyclic olefin resins such as cycloolefin polymer (COP) (hereinafter also referred to as cycloolefin resins), polypropylene resins such as polypropylene (PP), acrylic acid such as polymethyl methacrylate (PMMA) Series resins, and polyester resins such as polyethylene terephthalate (PET).

Especially for films with low modulus of elasticity, such as resins less than 3.0GPa, since the winding deviation is likely to occur when the film roll is formed, the static friction coefficient is controlled to satisfy the relational expressions (1) and (2) of the present invention. It is effective to use cyclic olefin polymer (COP) or polymethyl methacrylate (PMMA) of a film with a low elastic modulus as a thermoplastic resin film roll.

In addition, the effect of the present invention increases the value in the film area. The film thickness of the thin film is preferably 5 to 80 μm, more preferably 10 to 50 μm, and still more preferably 10 to 45 μm. When the film thickness is less than 10 μm, the rigidity of the film roll is low, and it is difficult to maintain the shape of the roll. When the film thickness exceeds 80μm, the mass increases, so it is not easy to make long film rolls.

[2.1.1] Cycloolefin resin The cycloolefin resin contained in the film roll of the present invention is preferably a polymer of a cycloolefin monomer, or a copolymer of a cycloolefin monomer and other copolymerizable monomers.

The cycloolefin monomer is preferably a cycloolefin monomer having a norbornene skeleton, more preferably a cycloolefin monomer having a structure represented by the following general formula (A-1) or (A-2).

In the general formula (A-1), R ¹ to R ⁴ each independently represent a hydrogen atom, a hydrocarbon group with 1 to 30 carbon atoms, or a polar group. p represents an integer from 0 to 2. However, ^{not all of R 1} to R ⁴ represent a hydrogen atom at the same time, R ¹ and R ² do not represent a hydrogen atom at the same time, and R ³ and R ⁴ do not represent a hydrogen atom at the same time.

In the general formula (A-1), ^{the hydrocarbon group having 1 to 30 carbon atoms represented by R 1} to R ⁴ is preferably a hydrocarbon group having 1 to 10 carbon atoms, and more preferably a hydrocarbon group having 1 to 5 carbon atoms. The hydrocarbon group having 1 to 30 carbon atoms, for example, may further have a linking group containing a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, or a silicon atom. Examples of such a linking group include divalent polar groups such as a carbonyl group, an imino group, an ether bond, a silyl ether bond, and a thioether bond. Examples of hydrocarbon groups with 1 to 30 carbon atoms include methyl, ethyl, propyl, and butyl.

^{Examples of polar groups represented by R 1} to R ⁴ in the general formula (A-1) include carboxyl, hydroxyl, alkoxy, alkoxycarbonyl, aryloxycarbonyl, amino, amide and cyano groups. Among them, carboxyl group, hydroxyl group, alkoxycarbonyl group and aryloxycarbonyl group are particularly preferred; from the viewpoint of ensuring solubility during solution film formation, alkoxycarbonyl group and aryloxycarbonyl group are preferred.

In general formula (A-1), p is preferably 1 or 2 from the viewpoint of improving the heat resistance of the optical film. This is because when p is 1 or 2, the volume of the obtained polymer becomes larger, and the glass transition temperature is easily increased.

In the general formula (A-2), R ⁵ represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms. R ⁶ represents a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an amino group, an amide group, a cyano group, or a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom). p represents an integer from 0 to 2.

^{R 5} in the general formula (A-1) preferably represents a hydrocarbon group having 1 to 5 carbon atoms, and more preferably represents a hydrocarbon group having 1 to 3 carbon atoms.

^{R 6} in the general formula (A-2) preferably represents a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, and an aryloxycarbonyl group. From the viewpoint of ensuring solubility during film formation from a solution, it is more preferably an alkoxycarbonyl group and an aryloxycarbonyl group. Oxycarbonyl.

In the general formula (A-2), p preferably represents 1 or 2 from the viewpoint of improving the heat resistance of the optical film. This is because when p represents 1 or 2, the volume of the obtained polymer becomes larger and the glass transition temperature is easily increased.

The cycloolefin monomer having the structure represented by the general formula (A-2) is preferable from the viewpoint of improving the solubility in organic solvents. Generally speaking, organic compounds disintegrate symmetrically, and their crystallinity is reduced, so their solubility in organic solvents is improved. ^{R 5} and R ⁶ in the general formula (A-2), with respect to the symmetry axis of the molecule, only one side of the ring constitutes a carbon atom, so the symmetry of the molecule is low, that is, it has the general formula (A-2 The cyclic olefin monomer of the structure indicated by) has high solubility, so it is suitable for the production of optical films by the solution casting method.

The content ratio of the cycloolefin monomer having the structure represented by the general formula (A-2) in the polymer of the cycloolefin monomer can be, for example, relative to the total of all the cycloolefin monomers constituting the cycloolefin resin 70 mol% or more, preferably 80 mol% or more, more preferably 100 mol%. When the cycloolefin monomer having a structure represented by the general formula (A-2) is included at a certain level or more, the orientation of the resin is improved, and therefore the retardation (hysteresis) value is likely to increase.

Below, exemplified compounds 1 to 14 show specific examples of cycloolefin monomers having the structure represented by the general formula (A-1), and exemplified compounds 15 to 34 show the cycloolefin monomers having the structure represented by the general formula (A-2) Specific examples of monomers.

Examples of copolymerizable monomers that can be copolymerized with cycloolefin monomers include copolymerizable monomers that can be ring-opened and copolymerized with cycloolefin monomers, and copolymerizable monomers that can be copolymerized with cycloolefin monomers by addition copolymerization Monomers and so on.

Examples of the copolymerizable monomer capable of ring-opening copolymerization include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene.

Examples of the copolymerizable monomer capable of addition copolymerization include compounds containing unsaturated double bonds, vinyl-based cyclic hydrocarbon monomers, and (meth)acrylates. Examples of compounds containing unsaturated double bonds include olefin compounds having 2 to 12 carbon atoms (preferably 2 to 8), and examples include ethylene, propylene, butene, and the like. Examples of vinyl-based cyclic hydrocarbon monomers include vinylcyclopentene-based monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene. Examples of (meth)acrylates include methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and cyclohexyl (meth)acrylate, etc. (methyl) ) Alkyl acrylate.

The content ratio of the cycloolefin monomer in the copolymer of the cycloolefin monomer and the copolymerizable monomer is, for example, 20 to 80 mol%, preferably 30, relative to the total of all monomers constituting the copolymer. ~70mol%.

As described above, the cycloolefin resin is used to polymerize a cycloolefin monomer having a norbornene skeleton, preferably a cycloolefin monomer having a structure represented by the general formula (A-1) or (A-2), or Examples of the polymer obtained by copolymerization include the following.

(1) Ring-opening polymer of cycloolefin monomer (2) Ring-opening copolymers of cycloolefin monomers and copolymerizable monomers capable of ring-opening copolymerization with them (3) Hydrogenated product of the ring-opening (co)polymer of (1) or (2) above (4) The ring-opening (co)polymer of (1) or (2) above is cyclized and hydrogenated (co)polymer by Friedel-Crafts reaction (5) Saturated copolymer of cycloolefin monomer and compound containing unsaturated double bond (6) Addition copolymers of cycloolefin monomers and vinyl cyclic hydrocarbon monomers and their hydrogenated products (7) Alternating copolymer of cycloolefin monomer and (meth)acrylate All of the above-mentioned polymers (1) to (7) can be obtained by a known method, such as the method described in Japanese Patent Application Publication No. 2008-107534 or Japanese Patent Application Publication No. 2005-227606. For example, as the catalyst or solvent used in the ring-opening copolymerization of (2) above, for example, those described in paragraphs 0019 to 0024 of JP 2008-107534 A can be used. As the catalyst used for the hydrogenation of the above (3) and (6), for example, those described in paragraphs 0025 to 0028 of JP 2008-107534 A can be used. As the acidic compound used in the Fridell-Kwaft reaction of (4), for example, the acid compound described in paragraph 0029 of JP 2008-107534 A can be used. As the catalyst used for the addition polymerization of the above (5) to (7), for example, those described in paragraphs 0058 to 0063 of JP 2005-227606 A can be used. The above-mentioned alternating copolymerization reaction of (7) can be carried out, for example, by the method described in paragraphs 0071 and 0072 of Japanese Patent Application Laid-Open No. 2005-227606.

Among them, the polymers of (1) to (3) and (5) above are particularly preferred, and the polymers of (3) and (5) above are more preferred. That is, the cycloolefin-based resin can make the obtained cycloolefin-based resin have a high glass transition temperature and a high light transmittance, and preferably contains the structural unit represented by the following general formula (B-1) and the following general At least one of the structural units represented by the formula (B-2); more preferably, only the structural unit represented by the general formula (B-2), or the structural unit represented by the general formula (B-1) and the general formula (B- 2) Both of the structural units indicated. The structural unit represented by the general formula (B-1) is a structural unit derived from the cycloolefin monomer represented by the aforementioned general formula (A-1), and the structural unit represented by the general formula (B-2) is derived from the aforementioned general formula (A-1). The structural unit of cycloolefin monomer represented by formula (A-2).

In the general formula (B-1), X represents -CH=CH- or -CH ₂ CH ₂ -. R ¹ ~ R ⁴ and R p are the general formula (A-1) of ¹ ~ R ⁴ and p are synonymous.

In the general formula (B-2), X represents -CH=CH- or -CH ₂ CH ₂ -. R ⁵ ~ R ⁶ and p are based of the general formula (A-2) of R ⁵ ~ R ⁶ and p are synonymous.

The cycloolefin resin of the present invention may also be a commercially available product. Examples of commercially available cycloolefin resins include Arton G (such as G7810, etc.), Arton F, Arton R (such as R4500, R4900, and R5000, etc.) manufactured by JSR (Stocks), and Arton RX.

The inherent viscosity of cycloolefin resin [η]inh, measured at 30°C, is preferably 0.2~5cm ³ /g, more preferably 0.3~3cm ³ /g, and even more preferably 0.4~1.5cm ³ /g .

The number average molecular weight (Mn) of the cycloolefin resin is preferably 8,000 to 100,000, more preferably 10,000 to 80,000, and still more preferably 12,000 to 50,000. The weight average molecular weight (Mw) of the cycloolefin resin is preferably 20,000 to 300,000, more preferably 30,000 to 250,000, and still more preferably 40,000 to 200,000. The number average molecular weight or weight average molecular weight of the cycloolefin resin can be measured in terms of polystyrene by gel permeation chromatography (GPC).

＜Gel Permeation Chromatography＞ Solvent: Dichloromethane Pillars: Shodex K806, K805, K803G (Connect 3 of Showa Denko Corporation to use) Column temperature: 25℃ Sample concentration: 0.1% by mass Detector: RI Model 504 (manufactured by GL Science) Pump: L6000 (manufactured by Hitachi, Ltd.) Flow rate: 1.0ml/min Calibration curve: The calibration curve is obtained by using 13 samples in the range of Mw=500-2,800,000 using standard polystyrene STK standard polystyrene (manufactured by Tosoh Co., Ltd.). The 13 samples are preferably used at approximately equal intervals.

If the intrinsic viscosity [η]inh, number average molecular weight, and weight average molecular weight are within the above ranges, the heat resistance, water resistance, chemical resistance, mechanical properties of the cycloolefin resin, and the molding processability as a film become good.

The glass transition temperature (Tg) of the cycloolefin resin is usually 110°C or higher, preferably 110 to 350°C, more preferably 120 to 250°C, and even more preferably 120 to 220°C. When the Tg is above 110°C, it is easy to suppress deformation under high temperature conditions. On the other hand, when the Tg is 350°C or less, the molding process becomes easy, and it is also easy to suppress the resin deterioration due to heat during the molding process.

The content of the cycloolefin resin relative to the film is preferably 70% by mass or more, and more preferably 80% by mass or more.

[2.1.2] Acrylic resin The acrylic resin of the present invention is a polymer of acrylate or methacrylate, and also includes copolymers with other monomers.

Therefore, the acrylic resin of the present invention also includes methacrylic resin. The resin is not particularly limited, and preferably contains a methyl methacrylate unit in the range of 50 to 99% by mass, and other monomer units copolymerizable therewith in the range of 1 to 50% by mass.

Other units constituting the acrylic resin formed by copolymerization include alkyl methacrylates with 2 to 18 carbon atoms in the alkyl group, alkyl acrylates with 1 to 18 carbon atoms in the alkyl group, and isomethacrylate. Acrylic acid hydroxyalkyl esters such as camphor and 2-hydroxyethyl acrylate; α,β-unsaturated acids such as acrylic acid and methacrylic acid; acrylic acid such as acrylomorpholine, N-hydroxyphenylmethacrylamide, etc. Amine, N-vinylpyrrolidone; dicarboxylic acids containing unsaturated groups such as maleic acid, fumaric acid, and itaconic acid; aromatic vinyl compounds such as styrene and α-methylstyrene; Acrylonitrile, methacrylonitrile, etc. α, β-unsaturated nitrile; maleic anhydride, maleimide, N-substituted maleimide, glutarimide, glutaric anhydride, etc.

The copolymerizable monomers that form units other than glutarimide and glutaric anhydride from the above-mentioned units include monomers corresponding to the above-mentioned units. Examples include alkyl methacrylates with carbon number of 2 to 18, alkyl acrylates with carbon number of 1 to 18, isobornyl methacrylate, 2-hydroxyethyl acrylate, etc. Hydroxyalkyl esters, acrylic acid; α,β-unsaturated acids such as methacrylic acid; acrylamide such as acrylomorpholine, N-hydroxyphenylmethacrylamide, N-vinylpyrrolidone; Malay Dicarboxylic acids containing unsaturated groups such as acid, fumaric acid and itaconic acid; aromatic vinyl compounds such as styrene and α-methylstyrene; α, β such as acrylonitrile and methacrylonitrile -Unsaturated nitriles; monomers such as maleic anhydride, maleimines, N-substituted maleimines.

In addition, the glutarimide unit can be formed, for example, by reacting an intermediate polymer having a (meth)acrylate unit with a primary amine (an imidating agent) to form an imidization (refer to Japanese Special (Refer to Bulletin No. 2011-26563).

The glutaric anhydride unit can be formed, for example, by heating an intermediate polymer having a (meth)acrylate unit (refer to Japanese Patent No. 4961164).

The acrylic resin of the present invention, among the above-mentioned structural units, in terms of mechanical strength, particularly includes isobornyl methacrylate, acrylomorpholine, N-hydroxyphenylmethacrylamide, and N-ethylene Cyclopyrrolidone, styrene, hydroxyethyl methacrylate, maleic anhydride, maleimide, N-substituted maleimide, glutaric anhydride, or glutaric anhydride are particularly preferred.

The acrylic resin of the present invention is from the viewpoint of controlling the dimensional change with respect to the temperature and humidity of the environment, or the viewpoint of improving the peelability from the metal support during film production, the drying property of organic solvents, the heat resistance and the mechanical strength. The weight average molecular weight (Mw) is preferably in the range of 50,000 to 1 million, more preferably in the range of 100,000 to 1 million, particularly preferably in the range of 200,000 to 800,000.

If it is 50,000 or more, the heat resistance and mechanical strength are excellent, and if it is 1,000,000 or less, the releasability from the metal support and the drying property of the organic solvent are excellent.

The method for producing the acrylic resin of the present invention is not particularly limited, and known methods such as suspension polymerization, emulsion polymerization, bulk polymerization, or solution polymerization can be used. Here, the polymerization initiator may be a normal peroxide type or an azo type, or it may be a redox type. Regarding the polymerization temperature, suspension or emulsion polymerization can be carried out in the range of 30~100°C, and mass or solution polymerization can be carried out in the range of 80~160°C. In order to control the reduction viscosity of the obtained copolymer, an alkyl mercaptan or the like can also be used as a chain transfer agent to carry out polymerization.

From the viewpoint of maintaining the mechanical strength of the film, the glass transition temperature Tg of the acrylic resin is preferably in the range of 80 to 120°C.

The acrylic resin of the present invention may also be commercially available. For example, Delpet 60N, 80N, 980N, SR8200 (above, manufactured by Asahi Chemicals Co., Ltd.), Dianal BR52, BR80, BR83, BR85, BR88, EMB-143, EMB-159, EMB-160, EMB-161, EMB -218, EMB-229, EMB-270, EMB-273 (above, manufactured by Mitsubishi Ink (stock)), KT75, TX400S, IPX012 (above, manufactured by Electric Chemical Industry (stock)), etc. Acrylic resins can also be used in combination of two or more types.

The acrylic resin of the present invention preferably contains an additive. An example of the additive is preferably to contain the acrylic particles (rubber elastomer particles) described in International Publication No. 2010/001668 for the purpose of improving the mechanical strength of the film or adjusting the dimensional change rate. . Examples of commercially available products of such multi-layered acrylic granular composites include "Metablen W-341" manufactured by Mitsubishi Mitsubishi Corporation, "Kaneace" manufactured by Kaneka Corporation, "Paraloid" manufactured by Kureha Corporation, and Rohm "Acryloid" manufactured by and Haas Corporation, "Staphyloid" manufactured by AICA Corporation, Chemisnow MR-2G, MS-300X (above, manufactured by Soken Chemical Co., Ltd.), and "Parapet SA" manufactured by Kuraray Corporation. Or use 2 or more types.

The volume average particle diameter of the acrylic particles is 0.35 μm or less, preferably 0.01 to 0.35 μm, more preferably 0.05 to 0.30 μm. If the particle diameter is more than a certain value, the film can be easily stretched under heating, and if the particle diameter is less than a certain value, the transparency of the resulting film will not be easily impaired.

From the viewpoint of flexibility, the film of the present invention preferably has a flexural modulus (JIS K7171) of 1500 MPa or less. The bending elastic modulus is more preferably 1300 MPa or less, and still more preferably 1200 MPa or less. The flexural modulus varies according to the type or amount of acrylic resin or rubber elastomer particles in the film. For example, the more the content of rubber elastomer particles, the lower the flexural modulus in general. Moreover, as an acrylic resin, compared with the homopolymer using alkyl methacrylate, the copolymer of alkyl methacrylate and alkyl acrylate etc. is used, and the flexural elastic modulus is generally lower.

[2.1.3] Cellulose ester resin In the film roll of the present invention, cellulose ester resin is also preferably used.

The cellulose ester used in the present invention means that part or all of the hydrogen atoms of the hydroxyl groups (-OH) at the 2-, 3- and 6-positions in the β-1,4-bonded glucose unit of cellulose are partially or completely acetylated Substituted cellulose acylate resin.

The cellulose ester used is not particularly limited, but is preferably an ester of a linear or branched carboxylic acid having a carbon number of about 2-22. The carboxylic acid constituting the ester may be an aliphatic carboxylic acid, may form a ring, or may be an aromatic carboxylic acid. For example, the hydrogen atom of the hydroxyl moiety of cellulose can be enumerated by acetyl, propyl, butyryl, isobutyryl, pentanyl, trimethyl acetyl, hexyl, octyl, lauryl, and stearin. A cellulose ester substituted with an acyl group of 2 to 22 carbon atoms. The carboxylic acid (acyl group) constituting the ester may have a substituent. The carboxylic acid constituting the ester is particularly preferably a lower fatty acid with a carbon number of 6 or less, and more preferably a lower fatty acid with a carbon number of 3 or less. Furthermore, the acyl group in the cellulose ester may be a single type or a combination of plural acyl groups.

Specific examples of preferred cellulose esters include cellulose acetate such as diacetyl cellulose (DAC), triacetyl cellulose (TAC), etc., in addition to cellulose acetate propionate (CAP), Cellulose acetate butyrate and cellulose acetate propionate butyrate are mixed fatty acid esters of cellulose bonded with propionate groups or butyrate groups except for the acetyl group. These cellulose esters can be used singly or in combination of multiple types.

(Type of base/degree of substitution) By adjusting the type and degree of substitution of the cellulose ester, the humidity variation of the phase difference can be controlled within a desired range, and the uniformity of the film thickness can be improved.

The smaller the degree of substitution of the cellulose ester of the acyl group is, the better the retardation exhibitability is, and therefore it becomes possible to make the film into a thin film. On the other hand, if the substitution of the acyl group is too small, the durability may be deteriorated, which is not good.

On the other hand, the greater the degree of substitution of the cellulose ester group is, the less retardation is exhibited. Therefore, it is necessary to increase the stretching magnification during film formation, but it is difficult to stretch uniformly at a high stretching magnification, so the film thickness deviation becomes larger ( deterioration). In addition, the hysteresis (phase difference) of the Rt humidity in the thickness direction is caused by the coordination of water molecules to the carbonyl group of the cellulose. Therefore, the degree of substitution of the acyl group is higher, that is, the more carbonyl groups in the cellulose, the Rt humidity changes. The more it tends to get worse.

The total degree of substitution of the cellulose ester is preferably 2.1 to 2.5. By setting it in this range, environmental fluctuations (especially Rt fluctuations due to humidity) can be suppressed, and the uniformity of the film thickness can be improved. From the viewpoint of improving the castability and extensibility during film formation, and further improving the uniformity of the film thickness, it is more preferably 2.2 to 2.45.

More specifically, the cellulose ester satisfies the following formulas (a) and (b) together. In the formula, X is the degree of substitution of acetyl group, and Y is the degree of substitution of propyl group or butyryl group, or the degree of substitution of a mixture thereof.

Formula (a): 2.1≦X+Y≦2.5 Formula (b): 0≦Y≦1.5 Cellulose ester, more preferably cellulose acetate (Y=0), and cellulose acetate propionate (CAP) (Y; Acrylonyl, Y>0), from the viewpoint of reducing film thickness deviation, it is more preferably Y =0 of cellulose acetate. Cellulose acetate, which is particularly preferably used, is based on the viewpoint that the retardation exhibitability, Rt humidity variation, and film thickness deviation are within the desired range. It is a cellulose diacetate of 2.1≦X≦2.5 (more preferably 2.15≦X≦2.45) Element (DAC). In addition, when Y>0, cellulose acetate propionate (CAP), which is particularly preferably used, is 0.95≦X≦2.25, 0.1≦Y≦1.2, and 2.15≦X+Y≦2.45.

By using the above-mentioned cellulose acetate or cellulose acetate propionate, a film roll with excellent hysteresis, mechanical strength and environmental fluctuations can be obtained.

Furthermore, the degree of substitution of the glycan refers to the average number of glycans per glucose unit, and it indicates how many hydrogen atoms of the hydroxyl groups at positions 2, 3, and 6 of a glucose unit are replaced by醯基. Therefore, the maximum degree of substitution is 3.0, which means that the hydrogen atoms of the hydroxyl groups at the 2-, 3-, and 6-positions are all replaced by acyl groups. These acyl groups may be substituted equally at the 2, 3, and 6 positions of the glucose unit, or may be substituted in a distributed manner. The degree of substitution is obtained by the method specified in ASTM-D817-96.

In order to obtain the desired optical properties, cellulose acetates with different degrees of substitution can be mixed and used. The mixing ratio of different cellulose acetates is not particularly limited.

The number average molecular weight (Mn) of the cellulose ester is in ^{the range of 2×10 4} to 3×10 ⁵ , further in the range of 2×10 ⁴ to 1.2×10 ⁵ , and further in the range of 4×10 ⁴ to 8×10 ⁴ In the range, the mechanical strength of the obtained film roll is improved, so it is better.

The number average molecular weight Mn of the cellulose ester is calculated by the gel permeation chromatography (GPC) measurement using the aforementioned measurement conditions.

The weight average molecular weight (Mw) of the cellulose ester is in the range of 2×10 ⁴ to 1×10 ⁶ , and then in the range of 2×10 ⁴ to 1.2×10 ⁵ , and further in the range of 4×10 ⁴ to 8×10 ⁴ In the range, the mechanical strength of the obtained film roll is improved, so it is better.

The raw material cellulose of cellulose ester is not particularly limited, and examples include cotton linter, wood pulp, kenaf and the like. In addition, the cellulose esters obtained from these can be mixed and used in any ratio.

Cellulose esters such as cellulose acetate and cellulose acetate propionate can be produced by known methods. Generally speaking, the raw material cellulose is mixed with specific organic acids (acetic acid, propionic acid, etc.), acid anhydrides (acetic anhydride, propionic acid anhydride, etc.), and catalysts (sulfuric acid, etc.), and then the cellulose is esterified and reacted. To produce the tri-ester of cellulose. In the triester, the three hydroxy groups of the glucose unit are replaced by the acidic acid of the organic acid.

When two types of organic acids are used at the same time, a mixed-ester type of cellulose ester can be produced, such as cellulose acetate propionate or cellulose acetate butyrate. Next, by hydrolyzing the triester of cellulose, a cellulose ester resin having the desired degree of substitution of acyl groups is synthesized. After that, the cellulose ester resin is produced through the steps of filtration, precipitation, water washing, dehydration, and drying. Specifically, it can be synthesized by referring to the method described in Japanese Patent Application Laid-Open No. 10-45804.

[2.1.4] Other additives The film roll of the present invention may contain the following as other additives in addition to the above-mentioned thermoplastic resin.

(a) Plasticizer The film roll of the present invention preferably contains at least one plasticizer for the purpose of imparting processability to a polarizing plate protective film or the like, for example. The plasticizer is preferably used alone or in combination of two or more types.

Among the plasticizers, especially containing at least one plasticizer selected from the group consisting of sugar esters, polyesters, and styrenic compounds, it can achieve a high degree of compatibility with effective control of moisture permeability and cellulose esters. From the viewpoint of compatibility of the substrate resin, it is preferable.

The plasticizer has a molecular weight of 15,000 or less, and furthermore, 10,000 or less, from the viewpoint of achieving both the improvement of moisture and heat resistance and the compatibility with base resins such as cellulose ester. When the compound having a molecular weight of 10,000 or less is a polymer, the weight average molecular weight (Mw) is preferably 10,000 or less. The preferred weight average molecular weight (Mw) is in the range of 100 to 10,000, more preferably in the range of 400 to 8,000.

Particularly in order to obtain the effects of the present invention, it is preferable to contain the compound having a molecular weight of 1500 or less in the range of 6-40 parts by mass relative to 100 parts by mass of the base resin, more preferably in the range of 10-20 parts by mass . By being contained within the above-mentioned range, it is preferable to achieve both effective control of moisture permeability and compatibility with the base resin.

＜Sugar Esters＞ The film roll of the present invention may contain sugar ester compounds for the purpose of preventing hydrolysis. Specifically, as the sugar ester compound, a sugar ester having at least one pyranose structure or a furanose structure having at least one pyranose structure or a furanose structure and all or a part of the OH group of the structure is esterified can be used.

＜Polyester＞ The film roll of the present invention preferably contains polyester.

The polyester is not particularly limited. For example, a hydroxyl-terminated polymer (polyester polyol) obtained by the condensation reaction of a dicarboxylic acid or these ester-forming derivatives and a diol can be used, or the poly A polymer in which the terminal hydroxyl group of the ester polyol is blocked by a monocarboxylic acid (terminally blocked polyester). The ester-forming derivatives referred to herein refer to esters of dicarboxylic acids, dicarboxylic acid chlorides, and anhydrides of dicarboxylic acids.

＜Styrenic compound＞ In the film roll of the present invention, in addition to the above-mentioned sugar esters and polyesters, or where they are substituted, styrene-based compounds can also be used for the purpose of improving the water resistance of the film.

The styrene-based compound may be a homopolymer of a styrene-based monomer, or a copolymer of a styrene-based monomer and other comonomers. The content ratio of the styrene-based monomer-derived constitutional unit in the styrene-based compound is preferably 30-100 mol%, more preferably 50-100 mol% in order to make the molecular structure have a large volume above a certain level. ear%.

Examples of styrene monomers include styrene; alkyl substituted styrenes such as α-methylstyrene, β-methylstyrene, p-methylstyrene, etc.; 4-chlorostyrene, 4-bromo Halogen substituted styrenes such as styrene; hydroxybenzene such as p-hydroxystyrene, α-methyl-p-hydroxystyrene, 2-methyl-4-hydroxystyrene, 3,4-dihydroxystyrene, etc. Ethylenes; Vinyl benzyl alcohols; Alkoxy substituted styrenes such as p-methoxystyrene, p-tert-butoxystyrene, m-tert-butoxystyrene, etc.; 3-vinyl Benzoic acid, 4-vinyl benzoic acid and other vinyl benzoic acids; 4-vinyl benzyl acetate; 4-acetoxy styrene; 2-butyl amide styrene, 4-methyl amide styrene , P-sulfonamide styrene and other amide styrenes; 3-aminostyrene, 4-aminostyrene, 2-isopropenylaniline, vinylbenzyldimethylamine and other aminobenzenes Ethylenes; Nitrostyrenes such as 3-nitrostyrene and 4-nitrostyrene; Cyanostyrenes such as 3-cyanostyrene and 4-cyanostyrene; Vinylphenylacetonitrile ; Aryl styrenes, indenes, etc., such as phenyl styrene. The styrene-based monomer may be one type, or two or more types may be combined.

(b) Arbitrary components The film roll of the present invention may contain other optional components such as antioxidants, colorants, ultraviolet absorbers, matting agents, acrylic particles, hydrogen-bonding solvents, and ionic surfactants. These components can be added in the range of 0.01 to 20 parts by mass relative to 100 parts by mass of the base resin.

＜Antioxidant＞ In the film roll of the present invention, conventionally known antioxidants can be used. Particularly preferably, compounds of lactone, sulfur, phenol, double bond, hindered amine, and phosphorus compounds can be used.

These antioxidants and the like are added in the range of 0.05-20% by mass, preferably 0.1-1% by mass relative to the resin of the main raw material of the film. Compared with using only one kind of antioxidants, synergistic effects can be obtained by combining several compounds of different systems. For example, it is preferable to use a combination of lactone-based, phosphorus-based, phenol-based, and double bond-based compounds.

＜Colorant＞ The film roll of the present invention preferably contains a coloring agent in order to adjust the color tone within a range that does not impair the effects of the present invention. The colorant means a dye or a pigment. In the present invention, it refers to the one that has the effect of making the hue of the liquid crystal screen into a blue hue, adjustment of the yellow index, and reduction of haze.

Various dyes and pigments can be used as colorants, but anthraquinone dyes, azo dyes, and phthalocyanine pigments are more effective.

＜Ultraviolet absorber＞ The film roll of the present invention can also be used on the visible side or the backlight side of a polarizing plate, so it can also contain an ultraviolet absorber for the purpose of imparting an ultraviolet absorbing function.

The ultraviolet absorber is not particularly limited, and examples thereof include benzotriazole-based, 2-hydroxybenzophenone-based, or phenyl salicylate-based ultraviolet absorbers. For example, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H -Triazoles such as benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-hydroxy-4-methoxybenzophenone, Benzophenones such as 2-hydroxy-4-octyloxybenzophenone and 2,2'-dihydroxy-4-methoxybenzophenone.

The above-mentioned ultraviolet absorbers can be used singly or in combination of two or more kinds.

The amount of ultraviolet absorber used varies depending on the type of ultraviolet absorber, use conditions, etc. Generally speaking, relative to the base resin, it is 0.05-10% by mass, preferably 0.1-5% by mass Range added.

＜Matting agent＞ In the film roll of the present invention, it is preferable to add fine particles (matting agent) that provide the film roll with sliding properties. In particular, from the viewpoints of improving the sliding properties of the surface C of the present invention, improving the sliding properties during winding, and preventing the occurrence of scratches or adhesions, addition is also effective.

As a matting agent, as long as it does not impair the transparency of the resulting film roll and has heat resistance during melting, it may be an inorganic compound or an organic compound. These matting agents may be used alone or in combination of two or more kinds.

By combining particles with different particle diameters or shapes (for example, needle-like and spherical, etc.), it is possible to achieve a high degree of compatibility between transparency and sliding properties.

Among these, since the refractive index is similar to the aforementioned cycloolefin resin, acrylic resin, or cellulose ester resin, it is particularly preferable to use silica having excellent transparency (haze).

For specific examples of silicon dioxide, it is preferable to use Aerosil (registered trademark) 200V, Aerosil (registered trademark) R972V, Aerosil (registered trademark) R972, R974, R812, 200, 300, R202, OX50, TT600, NAX50 (manufactured by Aerosil Co., Ltd. above), Seahostar (registered trademark) KEP-10, Seahostar (registered trademark) KEP-30, Seahostar (registered trademark) KEP-50 (above, manufactured by Nippon Shokubai Co., Ltd.), Sylophobic (registered trademark) 100 (manufactured by Fuji Silysia Co., Ltd.), Nipsil (registered trademark) E220A (Nippon Silicon Dioxide Industry Co., Ltd.) (Made by Admafine), Admafine (registered trademark) SO (made by Admatechs Co., Ltd.), etc.

The shape of the particles can be irregular, needle-shaped, flat, spherical, etc., without particular limitation. Especially when spherical particles are used, the transparency of the resulting film roll can be good, so it is preferable.

Since the particle size is close to the wavelength of visible light, light will scatter and the transparency will deteriorate, so it is preferably smaller than the wavelength of visible light, and more preferably less than 1/2 of the wavelength of visible light. If the size of the particles is too small, the sliding properties may not be improved, so the range of 80nm to 180nm is particularly preferred. Furthermore, the size of a particle refers to the size of the agglomerate when the particle is an agglomerate of primary particles. In addition, when the particle is not spherical, it means the diameter of a circle corresponding to its projected area.

Relative to the base resin, the matting agent is preferably added in the range of 0.05 to 10% by mass, more preferably 0.1 to 5% by mass.

[2.2] Manufacturing method of film roll The method of manufacturing a film roll of the present invention is characterized by having a step of subjecting at least the aforementioned part A or the aforementioned part B to a surface modification treatment.

In addition, the surface modification treatment is preferably performed only on the site B, and it is also preferred to perform both on the site A and the site B.

Furthermore, as described above, the knurled portion is preferably formed by laser knurling (laser method).

Since all follow the description in item [1], the method of manufacturing the film itself is added here.

As the manufacturing method of the film roll of the present invention, the film can be made by the usual inflation method, T-die method, calender method, cutting method, casting method, emulsion method, hot pressing In terms of manufacturing methods such as coloring suppression, suppression of foreign matter defects, suppression of optical defects such as die lines, etc., the film forming method is preferably the solution casting film forming method and the melt casting film forming method , Especially the solution casting method, because it obtains a uniform surface, it is better.

＜Solution casting method＞ When the film is formed by the solution casting method, the method of manufacturing the film roll of the present invention preferably includes the following steps: a step of dissolving a thermoplastic resin and the above additives in a solvent to prepare a dope (dissolving step; doping) Preparation step), the step of casting the dopant on an endlessly moving metal support (casting step), the step of drying the cast dopant into a web (solvent evaporation step), The step of peeling from the metal support (peeling step), the step of drying, stretching, and maintaining the width (extending/maintaining the width/drying step), and the step of winding the completed film into a roll (winding step). As a thermoplastic resin, cycloolefin resin or acrylic resin is particularly preferably used.

3 is a diagram schematically showing an example of a dopant preparation step, a casting step, and a drying step (solvent evaporation step) of the solution casting film forming method.

The large agglomerates are removed from the feed tank A41 with the filter A44, and the liquid is sent to the storage tank A42. After that, various additives are added to the main dopant dissolving tank 1 from the storage tank A42.

After that, the main dopant system is filtered through the main filter A3, and the additive liquid system is added to it from the A16 line.

In most cases, the main dopant may contain about 10-50% by mass of recycled waste.

Recycled waste is the finely pulverized film. It is the original film that has been cut off on both sides of the film produced when the film is made, or the original film is out of specification due to scratches.

In addition, as the raw material of the resin used for the preparation of the dopant, it is preferable to use one that has been pelletized in advance as the cellulose ester and other additives as the base resin.

The steps are explained below.

1) Dissolution step (dopant preparation step) Hereinafter, as an embodiment of the present invention, the dissolution step when using cycloolefin resin (hereinafter also referred to as COP) as a thermoplastic resin will be described as an example, but the present invention is not limited to this.

This step is a step in which the COP and other compounds depending on the situation are stirred in the dissolving tank in a solvent that is mainly a good solvent for the COP, and dissolved to form a dopant, or mixed in the COP solution depending on the situation Other compound solution, the step of forming the dopant of the main solution.

If the concentration of COP in the dopant is thicker, it is better to reduce the drying load after casting on the metal support. However, when the concentration of COP is too high, the load during filtration increases and the filtration accuracy becomes worse. Taking into consideration these concentrations, it is preferably 10 to 35% by mass, more preferably 15 to 30% by mass.

The solvent used for the dopant can be used alone or in combination of two or more. From the viewpoint of production efficiency, it is better to mix a good solvent and a poor solvent for COP. From the viewpoint of solubility of COP, more good solvents are good.

The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent. Good solvents and poor solvents are those that dissolve the used COP alone as good solvents, and those that swell or do not dissolve alone are defined as poor solvents. Therefore, depending on the average substitution degree of the COP, the good solvent and the poor solvent will change.

The good solvent used in the present invention is not particularly limited, and examples include organic halogen compounds such as methylene chloride or dioxolanes, acetone, methyl acetate, methyl acetylacetate, and the like. Particularly preferred are dichloromethane or methyl acetate.

In addition, the poor solvent used in the present invention is not particularly limited. For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone, etc. are preferably used. In addition, the water in the dopant preferably contains 0.01 to 2% by mass.

In addition, the solvent used for the dissolution of COP is recovered from the solvent removed from the film by drying in the film forming step, and reused.

The recovered solvent may also contain trace amounts of additives added to the COP, such as plasticizers, ultraviolet absorbers, polymers, monomer components, etc. The inclusion of these can be preferably reused, or refined and reused as needed.

A general method can be used for the method of dissolving the COP when preparing the dopant described above. Specifically, it is preferably a method performed at normal pressure, a method performed below the boiling point of the main solvent, and a method performed under pressure above the boiling point of the main solvent. When heating and pressurizing are combined, it can be heated to normal pressure. Above the boiling point.

In addition, the method of stirring and dissolving at a temperature above the boiling point of the solvent under normal pressure and the solvent does not boil under pressure will also prevent the generation of undissolved masses called gels or lumps. , So better.

In addition, it is also preferable to use a method of mixing the COP with a poor solvent to make it wet or swelling, and then further adding a good solvent to dissolve it.

Pressurization can be performed by a method of inert gas such as nitrogen, or a method of increasing the vapor pressure of the solvent by heating. The heating is preferably performed externally. For example, the temperature control of the sleeve type is easier and better.

From the viewpoint of the solubility of COP, the heating temperature for adding the solvent is preferably higher. However, if the heating temperature is too high, the necessary pressure will increase and productivity will deteriorate.

The preferred heating temperature is 45 to 120°C, more preferably 60 to 110°C, and even more preferably 70 to 105°C. In addition, the pressure system is adjusted so that the solvent does not boil at the set temperature.

Alternatively, it is also preferable to use a cooling dissolution method, whereby the COP can be dissolved in a solvent such as methyl acetate.

Next, it is preferable to filter the COP solution (the dopant in dissolution or after dissolution) using an appropriate filter medium such as filter paper.

As the filter material, in order to remove insoluble matter, etc., it is preferable to have a low absolute filtration accuracy. However, if the absolute filtration accuracy is too small, there is a problem that clogging of the filter material is likely to occur. Therefore, a filter material with an absolute filtration accuracy of 0.008mm or less is preferred, a filter material with an absolute filtration accuracy of 0.001~0.008mm is more preferred, and a filter material with a 0.003~0.006mm is more preferred.

There are no special restrictions on the material of the filter material. You can use ordinary filter materials, such as polypropylene, Teflon (registered trademark) and other plastic filters, or stainless steel and other metal filters. There is no fiber falling off. good.

It is preferable to remove and reduce the impurities contained in the COP of the raw material, especially the bright spot foreign matter, by filtering.

Bright spot foreign matter refers to arranging two polarizing plates in a crossed Nico state with a film or the like placed between them. The light is irradiated from one side of the polarizing plate and the light from the opposite side is leaked when viewed from the other side of the polarizing plate. For visible points (foreign objects), the number of bright points above 0.01mm in diameter should be 200 points/cm ² or less. It is more preferably 100 pieces/cm ² or less, still more preferably 50 pieces/m ² or less, and still more preferably 0-10 pieces/cm ² or less. In addition, it is better to have less brilliance points below 0.01 mm.

Filtration of the dopant can be carried out by the usual method, with the solvent at a temperature higher than the boiling point of the solvent under normal pressure, and the method of filtering while heating at a temperature in the range where the solvent does not boil under pressure, the filtration pressure before and after filtration The rise of the difference (called differential pressure) is small and better.

The preferred temperature is 45-120°C, more preferably 45-70°C, and still more preferably 45-55°C.

The filter pressure is preferably smaller. The filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and still more preferably 1.0 MPa or less.

2) Casting steps Then, the dopant is cast on the metal support. That is, in this step, the dopant is fed to the pressure die A30 through a liquid feeding pump (for example, a pressurized quantitative gear pump), and the endless metal belt A31, such as a stainless steel band, is transferred indefinitely. , Or the casting position on the metal support such as the rotating metal drum, the step of casting the dopant by the pressure die slit.

Preferably, it is a press mold that can adjust the slit shape of the joint part of the mold, and it is easy to make the film thickness uniform. The pressure die is a coat hanger die or a T die, etc., both of which can be preferably used. The surface of the metal support is preferably a mirror surface. In order to increase the film forming speed, two or more press molds may be set on the metal support, and the dopant amount may be divided and laminated. Or it is also preferable to obtain a film roll with a laminated structure by a co-casting method in which a plurality of dopants are cast at the same time.

The width of casting is preferably 1.3 m or more from the viewpoint of productivity. More preferably, it is 1.3~4.0m. When it exceeds 4.0 m, streaks may occur in the manufacturing step, or the stability in the subsequent conveying step may decrease. From the viewpoint of transportability and productivity, it is more preferably 1.3~3.0m.

The metal support in the casting step is preferably one whose surface has been mirror-polished. As the metal support, it is preferable to use a drum whose surface is plated with stainless steel belts or castings.

The surface temperature of the metal support in the casting step is -50℃~the temperature below the boiling point of the solvent. The higher the temperature, the faster the drying speed of the mesh is better, but if it is too high, the mesh may foam or become flat. Circumstances of sexual deterioration.

The preferred temperature of the support is 0 to 55°C, more preferably 22 to 50°C. Alternatively, it is also a preferable method to gel the mesh sheet by cooling, and peel it off from a drum while containing a large amount of residual solvent.

There are no special restrictions on the method of controlling the temperature of the metal support, and there are methods of blowing warm or cold air, or contacting warm water to the back side of the metal support. Since warm water is used to transfer heat more efficiently, it is preferable that the time until the temperature of the metal support becomes constant is short. In the case of using warm air, there is a case where the air with a higher temperature than the target temperature is used.

3) Solvent evaporation step This step is a step of heating the mesh (casting the dopant on the casting support, and the formed dopant film is called the mesh) on the casting support to evaporate the solvent.

To evaporate the solvent, there are methods of single-sided blowing from the net and/or the method of transferring heat from the back of the support through the liquid, the method of transferring heat from the front and back sides of the radiant heat, etc., which is the method of transferring heat from the back of the liquid The drying efficiency is good and better. Moreover, it is also better to use a combination of these methods. Preferably, the mesh on the support after casting is dried on the support in an environment of 35~100°C. To maintain the environment at 35~100°C, it is better to blow warm air at this temperature to the upper side of the mesh or heat by means such as infrared rays.

From the viewpoints of surface quality, moisture permeability, and peelability, it is preferable to peel the mesh from the support within 30 to 120 seconds.

4) Peeling step Next, the mesh sheet is peeled off from the metal support. That is, this step is a step of peeling the mesh sheet with the solvent evaporated on the metal support at the peeling position. The stripped mesh is sent to the next step.

The temperature of the peeling position on the metal support is preferably Within the range of -50~40℃, more preferably within the range of 10~40℃, and most preferably within the range of 15~30℃.

Furthermore, the amount of solvent remaining during the peeling of the mesh on the metal support at the time of peeling is appropriately adjusted according to the strength of the drying conditions, the length of the metal support, and the like. In order to make the film exhibit good flatness, the amount of residual solvent when the mesh is peeled off from the metal support is preferably 10 to 150% by mass. When peeling at a time when the amount of residual solvent is greater, when the mesh is too soft, the flatness will be damaged during peeling, and creases or vertical streaks caused by peeling tension are likely to occur. Therefore, the balance of economic speed and quality is used to determine the peeling The amount of residual solvent at the time. More preferably, it is 20-40% by mass or 60-130% by mass, particularly preferably 20-30% by mass or 70-120% by mass.

In the present invention, the amount of residual solvent is defined by the following formula.

Residual solvent amount (mass%)=((M-N)/N)×100 Furthermore, M is the mass of the sample taken during or after the manufacture of the mesh sheet or film at any point in time after manufacture, and N is the mass after heating M at 115°C for 1 hour.

The peeling tension when peeling the metal support from the film is preferably 300 N/m or less. It is more preferably in the range of 196 to 245 N/m, but when wrinkles are likely to occur during peeling, it is better to peel under a tension of 190 N/m or less. The peeling tension is preferably 300 N/m or less for peeling.

5) Drying/extending/maintaining width step (dry) In the drying step of the film, the mesh sheet is peeled off the metal support and further dried to make the residual solvent content less than 1% by mass, more preferably less than 0.1% by mass, and particularly preferably less than 0-0.01% by mass.

In the film drying step, generally, a roll drying method (a method in which the mesh sheet is alternately passed through a plurality of rollers arranged above and below and dried) or a method in which the mesh sheet is conveyed and dried while being dried by a tenter method is generally adopted. For example, after peeling, using a drying device 35 that makes the mesh alternately pass through a plurality of rollers arranged in the drying device and conveys it, and/or a tenter extension device 34 that clamps and conveys both ends of the mesh with a clip, To dry the mesh.

The means for drying the mesh is not particularly limited. Generally, hot air, infrared rays, heating rollers, microwaves, etc. can be used, and hot air is preferred from the viewpoint of simplicity. Excessive drying can easily damage the flatness of the finished film. The high-temperature drying can be performed starting from about 8% by mass or less of the residual solvent. Generally speaking, the drying is carried out in the range of 30~250°C. It is especially good to dry in the range of 35~200℃. The drying temperature is preferably increased in stages.

When using a stenter stretching device, it is better to use a device that can independently control the holding length of the film (the distance from the beginning of the holding to the end of the holding) on the left and right by the left and right holding means of the stenter. In addition, in the tentering step, in order to improve flatness, it is also preferable to intentionally create zones with different temperatures.

Furthermore, it is also preferable to set a neutral zone in a way that the respective zones between different temperature zones do not cause interference.

(Extend/Keep Width) Then, preferably, the mesh stripped from the metal support is stretched in at least one direction. Through the stretching process, the alignment of the molecules in the film can be controlled. In order to obtain the target hysteresis values Ro and Rt in the present invention, it is preferable that the film adopts the structure of the present invention, and the refractive index is controlled by the control of the conveying tension and the stretching operation. For example, the hysteresis value can be changed by making the tension in the longitudinal direction low or high.

The specific extension method can be performed on the length direction of the mesh (film making direction; casting direction; MD direction) and the direction perpendicular to the mesh surface, that is, the short-side direction (TD direction), successively or simultaneously for 2-axis extension or 1 axis extension. Preferably, it is a biaxially stretched film that is biaxially stretched in the casting direction (MD direction) and the short-side direction (TD direction), but the film of the present invention may be a uniaxially stretched film or an unstretched film. Furthermore, the extension operation can also be divided into multiple stages for implementation. In addition, the biaxial stretching can be performed simultaneously or in stages when performing biaxial stretching. In this case, it is stepwise. For example, different extensions in different extension directions may be performed sequentially, or the extension in the same direction may be divided into multiple stages, and extensions in different directions may be added at any stage.

For example, it can also be the following extension step: ･Extend in the casting direction→Extend in the short-side direction→Extend in the casting direction→Extend in the casting direction ･Extend in the short-side direction→Extend in the short-side direction→Extend in the casting direction→Extend in the casting direction In addition, simultaneous biaxial stretching also includes stretching in one direction and contracting the other by relaxing the tension.

The stretch magnification of the two orthogonal directions is preferably in the range of 0.8~1.5 times in the casting direction, 1.1~2.5 times in the short-side direction, 0.8~1.2 times in the casting direction, and 1.2~ in the short-side direction, respectively. A range of 2.0 times is better.

The stretching temperature is usually better than the temperature range of Tg~Tg+60°C of the resin constituting the film. Generally, the extension temperature is preferably 120°C to 200°C, and more preferably 120°C to 180°C.

The residual solvent in the mesh during stretching is preferably 20 to 0%, and more preferably 15 to 0% for stretching. For example, it is preferable to perform extension at 135°C with a residual solvent of 8%, or extend at 155°C with a residual solvent of 11%. Or it is better to extend at 155°C with a residual solvent of 2%, or preferably at 160°C to extend with a residual solvent of less than 1%.

The method of extending the mesh is not particularly limited. For example, a method of giving a circumferential speed difference to a plurality of rollers and using the difference in the circumferential speed of the rollers to extend in the longitudinal direction, fixing both ends of the mesh with clips or pins, so that the interval between the clips or pins is expanded in the advancing direction. The method of extending in the vertical direction, the method of extending in the horizontal direction and the method of extending in the horizontal direction, or the method of extending both vertically and horizontally at the same time, etc. Of course, these methods can also be used in combination. Among them, Youtejia stretches in the short-side direction (horizontal direction) in a tentering method in which both ends of the mesh are held by a clip or the like.

In the case of the so-called tentering method, when the clip portion is driven by a linear drive method, smooth extension can be performed and the risk of breakage can be reduced, so it is preferable.

It is preferable to use a tenter to maintain the width or horizontal extension of the film forming step, and it may be a pin tenter or a clip tenter.

The slow axis or fast axis of the film of the present invention exists in the film plane, and when the angle formed with the film forming direction is θ1, θ1 is preferably -1° or more +1° or less, more preferably -0.5° or more+ 0.5° or less.

This θ1 can be defined as the orientation angle, and the measurement of θ1 can be performed using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Measuring Instruments Co., Ltd.). Each of θ1 satisfies the above relationship, and can contribute to obtaining high brightness, suppressing or preventing light leakage in displaying images, and contributing to obtaining faithful color reproduction in color liquid crystal display devices.

6) Winding steps Finally, by winding the obtained mesh (finally trimmed film), a film roll is obtained. More specifically, after the amount of residual solvent in the mesh becomes 2% by mass or less, the winding machine A37 is used to wind into a film. By making the amount of residual solvent to 0.4% by mass or less, dimensional stability can be obtained. Good film. It is particularly good to wind in the range of 0.00~0.10% by mass.

The winding method can be used by general users, such as constant torque method, constant tension method, tapered tension method, program tension control method with fixed internal stress, etc., which can be used as appropriate.

Before winding, the ends are cut and cut off to become the width of the product. In order to prevent sticking or scratches during winding, the knurling process and surface modification treatment of the present invention are applied to both ends of the film.

Furthermore, the gripping parts of the clips at both ends of the film usually deform and cannot be used as a product, so they are cut off. When it does not cause deterioration of the material due to heat, it is recycled and reused.

The film roll of the present invention is preferably a long film, specifically a length of about 100 m to 10,000 m, and is usually provided in the form of a roll.

＜Details of film winding method＞ The film after knurling processing and surface modification treatment is preferably wound by the following winding method.

The winding method preferably includes a straight winding step in which the film is wound on the core in such a manner that the side edges of the film are aligned, and after the straight winding step, the side edge is shorter than the film. The side direction is periodically shifted in a certain range, and the film or the winding core is periodically vibrated in the short side direction of the film to wind the film on the winding core in an oscillating winding step.

In particular, it is preferable that the roll length of the aforementioned film reaches the predetermined switching roll length in the range of 10~30% relative to the full roll length of the aforementioned film, and the roll length is switched from the aforementioned straight winding step to the aforementioned Oscillate the winding step.

The film winding device preferably includes a film winding part that rotates the winding core and winds the film on the winding core so that the film is formed on the winding core and the short side direction of the film is periodically within a certain range. The offset oscillating winding method is linked to the winding of the film to vibrate the oscillating part of the film or the winding core in the short-side direction of the film, and the winding is switched when the roll length of the film reaches a predetermined value. For a long time, the winding of the film is switched from the straight winding to the switching part of the oscillating winding.

The following describes the oscillation winding.

As shown in FIG. 4, the film manufacturing line B10 is equipped with the film manufacturing apparatus B11 and the winding apparatus B12. The film manufacturing apparatus B11 manufactures the film B13 by the solution film forming method. In the solution film forming method, first, raw materials are used to prepare a dopant. Then, the prepared dopant is cast on the endless support to form a cast film. When the cast film becomes self-supporting, the cast film is peeled off by the endless support. The film B13 is formed by drying the peeled cast film with hot air or the like. The formed film B13 is sent to the winding device B12 through the knurling imparting roller B15. The knurling imparting roller B15 is formed by embossing or the like to form minute concavities and convexities on both side edges (ears) of the film B13 in the short side direction. Furthermore, the height of the unevenness formed by the knurling imparting roller is preferably in the range of 0.5-20 μm.

As shown in Figures 4 and 5, the winding device B12 includes a winding shaft B19, a core holder B20, a core B21, a turret B22, a guide roller B23, B24, a tension swing roller B25, and an encoder B27, oscillation part B29, winding motor B30, controller B31, and tension swing part B32. The film size of the winding object in the winding device B12 is not particularly limited. For example, it is preferably a film with a full-winding length in the range of 2000-10000 m and a width in the range of 500-2500 mm.

As shown in FIG. 5, the winding shaft B19 is mounted on the turntable B22 by a cantilever support mechanism. Cantilever support mechanism refers to a mechanism that supports only one end of the winding shaft B19. A winding core B21 is attached to the winding shaft B19. The winding core B21 is clamped at both ends by the winding core holder B20 of the winding shaft B19. The winding core holder B20 is slidably slidable in the axial direction (Y direction) of the winding shaft B19 and is installed in such a way that the winding shaft B19 cannot rotate. A winding motor B30 is connected to one end of the winding shaft B19, and is configured to rotate the winding shaft B19. By this rotation, the winding core B21 also rotates, and the film B13 can be wound on the winding core B21. By the winding of the film B13, the film roll B38 in which the film B13 is wound into a roll shape is obtained.

On the turntable B22, a displacement mechanism B28 is installed at the installation end of the winding shaft B19. The displacement mechanism B28 makes the winding core holder B20 move back and forth in the axial direction on the winding shaft B19. The displacement mechanism B28, the winding shaft B19, and the winding core holder B20 constitute the oscillating portion B29. The oscillating part B29 is actuated, and the core holder B20 is moved back and forth in the Y direction on the winding shaft B19 by the displacement mechanism B28, so that the position of the side edge B13a can be adjusted to the amplitude every time the film B13 is laminated. While shifting within the Wo range, oscillation winding in which the film B13 is wound is performed. When the oscillating part B29 is not actuated, the straight winding in which the both side edges of the film B13 are aligned is possible. The switching between the straight winding and the oscillating winding is performed by the controller B31.

Here, in the oscillation winding, the oscillation width Wo of the amplitude can be arbitrarily set. The amplitude Wo is preferably within the range of 10~30mm. If the amplitude Wo is within the aforementioned range, the amplitude Wo can be fixed at a certain value or slowly Land increases, decreases, or decreases after increasing.

The guide rollers B23, B24 and the tension swing roller B25 guide the film B13 from the film manufacturing device B11 in the conveying direction (X direction). In addition, the tension swing roller B25 moves the film B13 in the vertical direction (Z direction) by the displacement mechanism B26, thereby adjusting the winding tension of the film B13. The displacement mechanism B26 and the tension swing roller B25 constitute a tension swing portion B32. The encoder B27 sends the encoder pulse signal to the controller B31 whenever the guiding roller B24 rotates at a certain rotation angle. Furthermore, a tension sensor for measuring the winding tension of the film B13 can also be installed on the guide roller B24.

The controller B31 controls the driving of the oscillation part B29, the winding motor B30, and the tension swing part B32. The controller B31 includes a winding information input unit B39, a LUT memory B40, a winding length specifying unit B41 at the time of switching, a winding length measuring unit B42, and a switching determination unit B43. For the winding information input part B39, the winding information such as the total winding length, thickness, width, outer diameter of the winding core B21, and winding tension of the film B13 is input.

In the LUT memory B40, for each winding information, the roll length of the film B13 (the roll length when switching) is memorized when switching from straight winding to oscillating winding. When switching, the roll length is preferably preset in the range of 10-30% relative to the full roll length of the film B13, and more preferably set in the range of 15-25% relative to the full length of the film B13.

The timing to switch from straight winding to oscillating winding is more preferably when the roll length is in the range of 15-25% relative to the full roll length.

In addition, when the roll length is 10% or more relative to the full roll length, when switching from flat winding to oscillating winding, compared to the case of switching when it is less than 10%, it will be changed at the start of winding of film B13. It also prevents the surface pressure from dropping sharply. Therefore, it is possible to more reliably prevent the film roll B38 from winding loose or winding deviation. In addition, when the roll length exceeds 30% of the full roll length and is switched, the film B13 leaves the area where the stress in the circumferential direction of the film B13 is negative and is wound in a straight winding. Therefore, it is switched when it is less than 30%. In the case of film roll B38, it is prone to edge elongation. Therefore, when the roll length is 30% or less relative to the full roll length, switching from straight winding to oscillating winding can more reliably prevent edge elongation than when switching over 30%. .

The reel length specifying part B41 at the time of switching compares the winding information stored in the LUT memory B40 with the winding information input in the winding information input part B39 to specify the switching time volume corresponding to the input winding information long. The winding length measuring part B42 measures the winding length of the film B13 wound on the winding core B21 based on the encoder pulse signal from the encoder B27.

The switching determination unit B43 determines whether the roll length measured by the roll length measuring unit B42 exceeds the switching roll length specified by the switching roll length specifying unit B41. When it is determined that the winding length exceeds the switching winding length, an oscillation winding start signal is sent to the oscillation unit B29. When the oscillation part B29 receives the oscillation winding start signal, the winding of the film B13 is changed from the straight winding in which the film B13 is wound so that the side edges B13a of the film are aligned, and the position of the side edges B13a is changed to While shifting within the range of the amplitude Wo, the winding film B13 is oscillated and wound.

＜Melt casting film forming method＞ The film roll of the present invention can also be formed by a melt casting method.

The "melt film forming method" refers to a method in which a composition containing a thermoplastic resin and the above additives is heated and melted to a temperature showing fluidity, and then the melt containing the fluidity of the thermoplastic resin is cast. Thermoplastic resin, especially cellulose ester is used.

The heating and melting molding method can be classified into melt extrusion molding method, compression molding method, inflation method, injection molding method, blow molding method, stretch molding method, etc. in detail. Among these forming methods, the melt extrusion method is preferred in terms of mechanical strength and surface accuracy. The plural raw materials used in the melt extrusion method are usually preferably pre-kneaded and pelletized.

The pelletization can be a well-known method, for example, it can be extruded from a die by feeding dry cellulose ester, plasticizer, and other additives through a feeder to the extruder, kneading using a 1-axis or 2-axis extruder It is strand-shaped, and it is cut after water cooling or air cooling.

The additives can be pre-mixed before being supplied to the extruder, or can be supplied separately via separate feeders.

A small amount of additives such as particles or antioxidants must be uniformly mixed, so it is preferable to mix them in advance.

The extruder preferably suppresses the shearing force, and can be pelletized without deteriorating the resin (molecular weight reduction, coloring, gel formation, etc.), and is processed as low temperature as possible. For example, in the case of a 2-axis extruder, it is better to use a deep groove type screw that rotates in the same direction. In terms of the uniformity of mixing, the meshing type is better.

Using the pellets obtained as above, the film is formed. Of course, the raw material powder can be directly supplied to the extruder through the feeder without pelletizing, and the film can be directly produced.

The melting temperature of the above pellets when extruded with a 1-axis or 2-axis extruder is set to a temperature range of 200~300℃, filtered with a leaf disc filter, etc., after removing foreign matter, The T mold is cast in a film shape, and the film is pressed and rolled by a cooling roller and an elastic contact roller, and solidified on the cooling roller.

When it is introduced into the extruder from the feed funnel, it is also better to prevent oxidation and decomposition under vacuum or reduced pressure or in an inert gas environment.

The extrusion flow rate is preferably introduced into a gear pump or the like to be performed stably. In addition, it is preferable to use a stainless steel fiber sintered filter as the filter used for the removal of foreign matter. The stainless steel fiber sintered filter is produced in a complex intertwined state of the stainless steel fiber body and then compressed, and the contact parts are sintered and integrated. The density can be changed by the thickness and compression of the fiber, and the filtration accuracy can be adjusted.

Additives such as plasticizers and particles can be pre-mixed with the resin or kneaded on the way of the extruder. In order to add uniformly, it is preferable to use a mixing device such as a static mixer.

When the film is rolled by the cooling roller and the elastic contact roller, the temperature of the film on the side of the contact roller is preferably the temperature range of Tg~(Tg+110)°C of the film. A roller having an elastomer surface used for such a purpose can use a known roller.

Elastic contact roller, also known as squeeze rotating body. Commercially available elastic contact rollers can also be used.

When the film is peeled off by the cooling roller, it is preferable to control the tension to prevent the deformation of the film.

In addition, the film obtained as described above is preferably stretched by the aforementioned stretching operation after the step of contacting the cooling roller.

For the stretching method, a well-known roller stretching machine or a tenter, etc. can preferably be used. The specific conditions are the same as in the solution casting method.

Finally, as in the case of the solution casting method, the film roll of the present invention is obtained by winding the film obtained as described above.

[3] The purpose of the film The film rolled out of the film roll of the present invention is suitable for use as an optical film as a protective film for polarizing plates, etc., and can be used in various optical measurement devices, liquid crystal display devices, or organic electroluminescence display devices and other display devices. [Example]

Examples are listed below to specifically illustrate the present invention, but the present invention is not limited to these. Furthermore, in the embodiments, the expression "parts" or "%" is used, and unless otherwise specified, it means "parts by mass" or "% by mass".

＜Production of film roll＞ (Example 1) ＜Synthesis of cyclic polyolefin polymer P-1＞ 100 parts by mass of refined toluene and 100 parts by mass of methyl norbornene carboxylate were put into the reactor. Then 25mmol% of ethyl caproate-Ni dissolved in toluene (for monomer mass), tris(pentafluorophenyl) boron 0.225mol% (for monomer mass) and triethylaluminum 0.25 dissolved in toluene mol% (to the monomer quality) is put into the reactor. The reaction was carried out for 18 hours while stirring at room temperature. After the reaction is completed, the reaction mixture is poured into excess ethanol to precipitate the polymer. The polymer (P-1) obtained by the refined precipitation was dried under vacuum drying at 65°C for 24 hours.

＜Production of dopant D-1＞ The following composition was put into a mixing tank, stirred to dissolve each component, and filtered with a filter paper with an average pore diameter of 34 μm and a sintered metal filter with an average pore diameter of 10 μm to prepare a dopant.

Cyclic polyolefin polymer P-1 150 parts by mass Dichloromethane 380 parts by mass Methanol 70 parts by mass Next, the following composition containing the cyclic polyolefin solution (dopant) produced by the above-mentioned method was put into a disperser to prepare a fine particle dispersion liquid (M-1).

Micro particles (Aerosil R812: manufactured by Japan Aerosil Corporation, primary average particle diameter: 7nm, apparent specific gravity 50g/L) 4 parts by mass Dichloromethane 76 parts by mass Methanol 10 parts by mass Cyclic polyolefin solution (dopant D-1) 10 parts by mass 100 parts by mass of the cyclic polyolefin solution and 0.75 parts by mass of the fine particle dispersion were mixed to prepare a dopant for film formation. The dopant was cast on a film-forming line with a width of 1800mm, dried on a metal support until the dopant had self-supporting properties, then it was peeled off as a mesh and introduced into a tenter.

The residual solvent of the mesh at the time of introduction into the tenter is 5-15% by mass. The stenter is conveyed with the elongation in the short-side direction of 20% and the temperature inside the stenter is 160°C. After that, it was dried and cut and adjusted to a film roll width of 2000 mm and a film thickness of 40 μm.

＜Knurling processing steps＞ Irradiate laser light to form a knurled part (part A).

The knurling width at both ends is 15mm away from the film end. The linear speed of transporting the film is 10m/min.

The laser device uses a carbon dioxide laser device. The output of the laser device is 20W, the center wavelength of the light output wavelength is 9.4μm, and the light wavelength range is ±0.01μm or less centered on the center wavelength.

The laser light irradiates the film by reflecting the collimated light beam emitted by a carbon dioxide laser device with two galvanometer mirrors, passing through an fθ lens (focus distance 200mm), and condensing the light on the surface of the film being transported. . By controlling the angle of the galvanometer mirror, the condensing position is moved in the direction of the film plane, thereby controlling the trajectory of the laser light on the film surface.

＜Surface modification treatment: Atmospheric piezoelectric slurry treatment steps＞ Install Kasuga Denki's AGP-500 on the back side (part B) of the knurled part (part A) of the film, and irradiate 0.5kW. The distance between the probe that emits atmospheric pressure and the membrane is set to 5 mm. The setting position of the irradiated atmospheric piezoelectric paste is on the back side of the film opposite to the knurled processing part, which can irradiate 110% of the width of the knurled processing part.

＜Winding procedure＞ The film that has undergone the above knurling process is wound up. The initial tension is 150N, the taper is 70%, and the corner is 25%.

With TR, the average air layer thickness contained in the film roll is suppressed to 1.0 μm.

It is implemented with a roll length of 4000m and a width of 1.5m.

Through the above steps, the film roll of Example 1 was produced.

(Comparative example 1) The film roll of Comparative Example 1 was produced in the same manner as in the production of the film roll of Example 1, except that the <atmospheric pressure slurry treatment step> was not included.

(Comparative example 2) The film roll of Comparative Example 2 was produced in the same manner as in the production of the film roll of Example 1, except that the <atmospheric pressure slurry treatment step> was carried out as follows.

＜Processing steps of atmospheric piezoelectric slurry＞ Ten Kasuga Denki AGP-500 units were installed on the short side of the membrane to irradiate 1.0kW. The distance between the probe that emits atmospheric pressure and the membrane is set to 10 mm. The irradiated atmospheric piezoelectric paste is set to spread over the entire width of the film.

(Example 2) ＜Preparation of rubber particles B-1＞ Put 38.2 liters of ion-exchanged water and 111.6 g of sodium dioctyl sulfosuccinate into a reactor with an internal volume of 60 liters and a reflux cooler. While stirring at 250 rpm, the temperature is raised to 75°C in a nitrogen environment. Make it into a state of substantially anaerobic influence. Add 0.36g of ammonium persulfate (APS), stir for 5 minutes and add a single batch containing 1657g of methyl methacrylate (MMA), 21.6g of butyl acrylate (BA), and 1.68g of allyl methacrylate (ALMA) at one time. After the detection of the exothermic peak, the body mixture (c1) is kept for a further 20 minutes to complete the polymerization of the innermost hard layer.

Next, 3.48 g of ammonium persulfate (APS) was added, and after stirring for 5 minutes, 1961 g of butyl acrylate (BA), 346 g of methyl methacrylate (MMA), and allyl methacrylate ( ALMA) 264.0g of monomer mixture (a1) (BA/MMA=85/15 mass ratio), after the addition, keep it for another 120 minutes to complete the polymerization of the soft layer.

Next, 1.32 g of ammonium persulfate (APS) was added, and after stirring for 5 minutes, a monomer mixture (b1) containing 2106 g of methyl methacrylate (MMA) and 201.6 g of butyl acrylate (BA) was continuously added over 20 minutes, After the addition is completed, it is maintained for a further 20 minutes to complete the polymerization of the hard layer 1.

Next, 1.32 g of ammonium persulfate (APS) was added, and after 5 minutes, 3148 g of methyl methacrylate (MMA), 201.6 g of butyl acrylate (BA), and n-octyl mercaptan ( n-OM) 10.1 g of the monomer mixture (b2), kept for another 20 minutes after the addition is complete. Then, the temperature was raised to 95° C. and maintained for 60 minutes to complete the polymerization of the hard layer 2.

A small amount of the obtained polymer latex was collected, and the average particle diameter was determined by the absorbance method, and it was 0.10 μm. The remaining latex was poured into a 3% by mass sodium sulfate warm aqueous solution to be salted out/solidified, and then dehydrated/washed repeatedly, and then dried to obtain acrylic particles with a 4-layer structure. The obtained rubber particles B-1 had an average particle diameter of 200 nm and a glass transition temperature (Tg) of -30°C.

＜Production of film roll＞ After mixing 22.6 parts by mass of rubber particles with 400 parts by mass of dichloromethane in a dissolver for 50 minutes, they were dispersed using a Milder disperser (manufactured by Taiheiyo Machinery Co., Ltd.) at 1500 rpm to obtain a rubber particle dispersion. . After that, the rubber particle dispersion was allowed to stand still in the storage tank for 6 hours, and was continuously stirred during storage.

(Modulation of dopants) Next, a dopant of the following composition was prepared. First, add dichloromethane and ethanol to the pressurized dissolution tank. Next, in a pressurized dissolution tank, mix methyl methacrylate (MMA)/N-phenylmaleimide (PMI)=85/15, glass transition temperature (Tg) 120°C, and weight average molecular weight 2 million The acrylic resin (marked as polymethyl methacrylate: PMMA in the table) was added while stirring. Next, the rubber particle dispersion liquid prepared above was put in, heated to 60°C, and completely dissolved while stirring. The heating temperature was increased from room temperature at 5°C/min, and after being dissolved in 30 minutes, the temperature was lowered at 3°C/min. After filtering the resulting solution with a filter with a filtration accuracy of 30 μm, a dopant is obtained.

(Composition of dopant) Acrylic resin (PMMA) 70 parts by mass Ethanol 50 parts by mass Rubber particle dispersion 400 parts by mass Next, using an endless endless belt casting device, the dopant was uniformly cast on a stainless belt support at a temperature of 31° C. and a width of 1800 mm. The temperature of the stainless steel strip is controlled at 28°C. The conveying speed of the stainless steel belt is set to 20m/min.

The subsequent steps are the same as the production of the film roll of Example 1, and the film roll of Example 2 is produced.

(Example 3) In the production of the film roll of Example 1, the film roll was produced in the same manner, except that the knurled portion was formed under the following knurling processing conditions.

The knurling process is implemented as follows.

＜Knurling processing conditions＞ Processing temperature: 250℃ Processing pressure: 0.5MPa Knurled counter roller: metal rear roller

(Example 4) In the production of the film roll of Example 1, plasma treatment was performed on both sides of the knurled part (part A) and the opposite film back part (part B) in the <atmospheric pressure slurry treatment step>.

(Example 5) In the production of the film roll of Example 1, after drying on a metal support until the dopant is self-supporting, it was peeled off as a mesh, and a surface profile transfer roller was used (the arithmetic average surface roughness Ra 1.2μm The transfer roller) transfers the surface shape to the film portion while conveying it, and then performs plasma treatment on the knurled portion (part A) in the above-mentioned <atmospheric pressure slurry treatment step>.

(Example 6) (Preparation of fine particle additive liquid) Micro particles (Aerosil R812: manufactured by Japan Aerosil Co., Ltd., primary average particle diameter: 7nm, apparent specific gravity 50g/L) 4 parts by mass Dichloromethane 48 parts by mass Ethanol 48 parts by mass After mixing the above with a dissolver for 50 minutes, use Manton- Gaulin homogenizer for dispersion.

Furthermore, it is dispersed with an attritor until the particle size of the secondary particles becomes a specific size. This was filtered with Finemet NF manufactured by Nippon Seiki Co., Ltd. to prepare a fine particle additive liquid.

＜Preparation of dopant CAP-1＞ Cellulose acetate propionate (CAP: degree of substitution of acetyl group X, degree of substitution of propyl group Y: X+Y=2.45/Y: 1.0) 100 parts by mass Dichloromethane 200 parts by mass Ethanol 10 parts by mass Microparticle additive liquid 3 parts by mass Then, using an endless endless belt casting device, the above-mentioned dopant P-1 was uniformly cast on the stainless steel belt support at a temperature of 33° C. and a width of 1800 mm. The temperature of the stainless steel strip is controlled at 30°C.

On the stainless steel belt support, the solvent evaporates to 75% of the residual solvent in the cast film, and is peeled from the stainless steel belt support with a subsequent peeling tension of 130 N/m.

The peeled cellulose acetate propionate (CAP) film was stretched 20% in the short-side direction using a tenter while applying heat at 160°C. Next, the drying area is transported by a large number of rollers, and the drying is ended at the same time. The drying temperature was 130°C, and the conveying tension was 100 N/m. After drying, the film was cut into a width of 2000 mm, and both ends of the film were knurled in a width of 15 mm. The "atmospheric pressure slurry treatment step" was performed in the same manner as the film roll of Example 1, and the film was wound into a roll shape.

(Example 7) In the production of the film roll of Example 1, the film roll was produced in the same manner, except that the film was cut into a film roll with a width of 1.3 m.

(Example 8) In the production of the film roll of Example 1, the film roll was produced in the same manner except that the elongation ratio was 60% and the film roll had a width of 2500 mm.

(Example 9) In the production of the film roll of Example 1, the film roll was produced in the same manner except that the casting dopant amount was adjusted so that the film thickness of the film was 20 μm.

(Example 10) In the production of the film roll of Example 1, the film roll was produced in the same manner except that the casting dopant amount was adjusted so that the film thickness of the film was 15 μm.

(Example 11) In the production of the film roll of Example 1, the film roll was produced in the same way, except that the back surface was modified in the following steps instead of plasma treatment.

<Corona discharge treatment> The above-mentioned film roll was subjected to a corona discharge treatment at the site B. The distance from the dielectric in corona discharge is 2mm, and the electron irradiation is 500W/m ² /min.

(Example 12) The film roll was produced in the same manner as in the production of the film roll of Example 1, except that the fine particle dispersion liquid used in Example 1 was changed as follows.

Micro particles (Aerosil R812: manufactured by Japan Aerosil, primary average particle diameter: 7nm, apparent specific gravity 50g/L) 8 parts by mass Dichloromethane 72 parts by mass Methanol 10 parts by mass Cyclic polyolefin solution (dopant D-1) 10 parts by mass

(Example 13) The film roll was produced in the same manner as in the production of the film roll of Example 4, except that the fine particle dispersion liquid used in Example 1 was changed as follows.

Micro particles (Aerosil R812: manufactured by Japan Aerosil, primary average particle diameter: 7nm, apparent specific gravity 50g/L) 2 parts by mass Dichloromethane 78 parts by mass Methanol 10 parts by mass Cyclic polyolefin solution (dopant D-1) 10 parts by mass

≪Evaluation≫ ＜Measurement of static friction coefficient＞ A part of the film rolls produced above was cut, and the static friction coefficient was measured by the measuring machine below.

Static friction tester: Toyo Seiki FRICTION TESTER TR Friction measurement conditions: The above-made film (knurled part (part A) and non-knurled part (face C), surface modification part (part A or part B) are stacked separately The static friction coefficients were measured at loads of 0.166g/mm ² , 0.83g/mm ² , and 1.66g/mm ^{2. The} values are the average values of the static friction coefficients in 3 loads. In the table, in terms of A/B, it is The part A is the upper side and the part B is the lower side, and the same measurement is performed by superimposing them.

In Table I, when the relational expressions (1) and (2) of the present invention are satisfied, they are marked as ○, and when they are not satisfied, they are marked as x.

<Strong tendon assessment> Rib ribs refer to the band-shaped ridges parallel to the circumferential direction of the film roll produced on the surface of the film roll. The violent tendons are caused by the overlapping of the thick parts of the membrane or the adhesion of the membranes each time they circulate. When the film roll produces violent streaks, traces remain on the surface of the film, which tends to reduce the quality of the film or the optical properties of the film.

The evaluation is a visual evaluation to confirm the occurrence and extent of the violent tendons.

＜Evaluation of winding deviation＞ As the evaluation of the winding deviation, the produced film roll was subjected to a vibration test.

The vibration test was implemented in a way that an impact of 8G was quickly applied to the film roll.

After the impact is given, the film roll is checked, and if there is a part deviated by 5mm or more from the original winding position, it will be judged as "wound deflection".

The composition and evaluation results of the above film rolls are shown in Table 1.

It can be seen from Table I that in the film roll examples 1-13 of the present invention, by controlling the static friction coefficient to satisfy the relational expressions (1) and (2), as the relationship between the static friction coefficient of each part, the comparison with the comparative example can be obtained. For film rolls, film rolls with excellent adhesion resistance (strike ribs) and winding offset resistance. In addition, from the comparison between Example 1 and Example 12, and Example 4 and Example 13, it can be seen that by controlling the static friction coefficient to satisfy the formula (3), the blocking resistance and the winding offset resistance are further improved.

1: membrane 2: Approaching the roller 3: touch roller 4: embossed ring 5: Metal rear roller 6: Rubber rear roller 7: Laser light 8: Convex shape part (knurled) 10: Film roll A: Part A B: Part B C: Face C A1: Dissolving kettle A2, A5, A11, A14: liquid feeding pump A3, A6, A12, A15: filter A4, A13: storage tank A8, A16: Catheter A10: Feeding kettle for additives A20: Confluence pipe A21: Mixer A30: Mould A31: Metal support A32: Mesh A33: Peeling position A34: Tentering device A35: Roller drying device A36: Roller A37: Coiler A41: Storage tank A43: Pump A44: Filter B10: Film manufacturing line B11: Film manufacturing equipment B12: Winding device B13: Membrane B15: Knurling imparting part B19: Winding shaft B20: Core holder B21: Core B22: turntable B23, B24: guide roller B25: Tension swing roller B26: Displacement mechanism B27: encoder B28: Displacement mechanism B29: Oscillation part B30: Winding motor B31: Controller B32: Tension swing part B39: Winding information input unit B40: LUT memory section B41: Specific part of roll length when switching B42: Roll length measurement department B43: Switching Judgment Unit

[Figure 1] A schematic view of a film roll that has undergone knurling and surface modification treatment and is wound. [Figure 2] A conceptual diagram illustrating the method of knurling processing. [Fig. 3] A schematic diagram showing a method of manufacturing a film by a solution casting method. [Figure 4] A schematic view of the film manufacturing line. [Figure 5] Plan view of the winding device.

1: membrane

2: Approaching the roller

3: touch roller

10: Film roll

A: Part A

B: Part B

C: Face C

Claims (9)

A film roll, which is a film roll with knurled processing parts on at least both ends of the short side direction of the film, characterized by Take the aforementioned knurled part as part A, the part on the back side of the film opposite to this part A as part B, and the unknurled film surface other than this part A and part B as surface C, and When the static friction coefficients of part A and part B are a and b respectively, Satisfy the following relations (1) and (2); Equation (1) The coefficient of static friction between surfaces C<the coefficient of static friction between part A and part B, Formula (2) a<b. Such as the film roll of claim 1, wherein the aforementioned a and b satisfy the following relationship (3); Formula (3) 0.3<a/b<0.8. Such as the film roll of claim 1 or claim 2, wherein the short side length of the aforementioned film is in the range of 1.3~3.0m. Such as the film roll of any one of claim 1 to claim 3, wherein the film thickness of the aforementioned film is in the range of 10 to 45 μm. The film roll according to any one of claims 1 to 4, wherein the aforementioned film contains a cyclic olefin resin or an acrylic resin. A method for manufacturing a film roll, which is a method for manufacturing a film roll such as the film roll of any one of claims 1 to 5, characterized by having at least surface modification of the aforementioned part A or the aforementioned part B Processing steps. The film roll manufacturing method of claim 6, wherein only the aforementioned part B is subjected to the aforementioned surface modification treatment. The method for manufacturing a film roll of claim 6, wherein the surface modification treatment is performed on both the aforementioned part A and the aforementioned part B. The method for manufacturing a film roll according to any one of claims 6 to 8, wherein the knurled portion is formed by laser knurling.

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