KR20190103417A - Thermoplastic Film and Manufacturing Method of Thermoplastic Film - Google Patents

Abstract

The ratio Er ³⁰ in 30 ^degreeC of the elasticity modulus E ^TD of the film width direction orthogonal to the film conveyance direction with respect to the elasticity modulus E ^MD of a film conveyance direction is 1.1-1.8, and the elastic modulus E ^TD with respect to an elastic modulus E ^MD , the maximum value is selected from a non-Er ^30, non Er ¹⁸⁰ in the non-Er ^150, and 180 ℃ in non Er ^120, 150 ℃ in non Er ^90, 120 ℃ at 90 ℃ at 30 ℃ Er _max and Min Er _min It is a thermoplastic resin film whose difference is 0.7 or less, and a manufacturing method of a thermoplastic resin film.

Description

 Thermoplastic Film and Manufacturing Method of Thermoplastic Film

The present disclosure relates to a thermoplastic resin film and a method for producing a thermoplastic resin film.

A thermoplastic resin film is manufactured by melt-extruding a thermoplastic resin and forming into a film, and after passing through heat processing, such as extending | stretching and heat relaxation. Moreover, in recent years, a thermoplastic resin film is apply | coated or affixed a functional material on the film, and various functions are provided and it is used widely as a functional film.

On the other hand, in the case of the thermoplastic resin film of a thin film, when heat processing is performed in the process of providing a function to a film, it may generate | occur | produce so that the stripe-like wrinkles extended in a film conveyance direction may be arranged in a film width direction during heat processing. . Since the shape of the wrinkles is fixed by cooling after the heat treatment, there may be a problem in appearance due to a failure such as film quality or uneven coating.

As a technique related to the above, for example, JP 2014-238612A uses a base film having a tensile modulus of 140 MPa or more in which the film conveying direction is in the tensile direction, thereby suppressing defects such as wrinkles in the base film. Techniques are disclosed.

For example, JP 2014-210433 A discloses a polyester resin molded film having an elastic modulus at 30 ° C. and 100 ° C. in a specific range from the viewpoint of shape stability and flexibility of the film.

As for the technique for improving the wrinkles or flatness of the film, various studies have been made in the past as described above, and for example, lowering the conveying tension in each step is also performed. However, wrinkles tending to appear in a wave shape in the film width direction are easily torsion of the film when thermally contracted by the heat treatment of the film, or the ease of movement of the film when the film is thermally expanded (for example, the film on the conveying roll surface). And the like, such as the sliding property of).

In Patent Documents 1 and 2, a technique of improving the generation of wrinkles by adjusting the elastic modulus in one direction of the film is disclosed, but for example, simply adjusting the elastic modulus in the film conveying direction, In the film of the property which a barrier generate | occur | produces when spreading and releasing the dimensional change of one direction by thermal expansion to another direction, sufficient improvement effect cannot be expected.

And the wrinkles which generate | occur | produce in a film become remarkable, and the frequency of wrinkles becomes large, so that the thickness of a film is thin.

This indication is made | formed in view of the above.

An object of one embodiment of the present disclosure is to provide a thermoplastic resin film in which the occurrence of wavy wrinkles is reduced.

Another object to be solved by another embodiment of the present disclosure is to provide a method for producing a thermoplastic resin film in which wavy corrugations are less likely to occur even when a thin (preferably 200 μm or less) thermoplastic resin film is heated and conveyed. It is in doing it.

The following aspects are included in the specific means for achieving the said subject.

The ratio Er ³⁰ in 30 ^degreeC in the elasticity modulus E ^TD of the film width direction orthogonal to the film conveyance direction of the elasticity modulus E ^MD of a <1> film conveyance direction is 1.1-1.8, and the elasticity modulus with respect to an elastic modulus E ^MD E ^TD, non Er ^30, the maximum value is selected from a non-Er ¹⁸⁰ in the non-Er ^150, and 180 ℃ in non Er ^120, 150 ℃ in non Er ^90, 120 ℃ at 90 ℃ Er in the 30 ℃ _It is a thermoplastic resin film whose difference of _max and minimum value Er _min is 0.7 or less.

Surface roughness Ra of <2> at least one surface is a thermoplastic resin film as described in <1> which is 0.5 nm-50 nm.

<3> is a thermoplastic resin film as described in <1> or <2> whose thickness is 200 micrometers or less.

It is a thermoplastic resin film in any one of <1>-<3> which is a <4> polyester film or a cyclic polyolefin film.

<5> As a manufacturing method of the thermoplastic resin film in any one of <1>-<4>,

Melting and extruding the raw material resin and cooling to form a thermoplastic resin sheet;

Performing a first drawing in the longitudinal direction with respect to the molded thermoplastic resin sheet to obtain a thermoplastic resin film;

A preheating part for preheating the thermoplastic resin film, a drawing part for stretching and stretching the preheated thermoplastic resin film in the film width direction orthogonal to the longitudinal direction of the thermoplastic resin film, and heating and heat setting the thermoplastic resin film subjected to tension And a step of carrying out the second stretching by sequentially conveying the thermoplastic resin film to the heat-relaxing portion and the heat-relaxing portion for heat-relaxing the tension, and the cooling portion for cooling the heat-relaxed thermoplastic resin film.

The area magnification which is the product of the draw ratio in a 1st stretch and the draw ratio in a 2nd stretch is 12.8 times-15.5 times,

The process of performing a 2nd extending | stretching gives a tension to the said heat-relaxed thermoplastic resin film further in the film width direction in a cooling part, and -1.5%-with respect to the film width at the time of completion | finish of heat relaxation in a heat relaxation part. It is a manufacturing method of a thermoplastic resin film which expands or contracts a thermoplastic resin film in 3% of range.

The process of performing <6> 2nd extending | stretching is a manufacturing method of the thermoplastic resin film as described in <5> which extends a thermoplastic resin film in a extending | stretching part as 8% / sec-45% / sec.

The process of <7> 2nd extending | stretching is a manufacturing method of the thermoplastic resin film as described in <5> or <6> which extends a thermoplastic resin film in a extending | stretching part as 15% / sec-40% / sec. to be.

The process of <8> 2nd extending | stretching produces the thermoplastic resin film in any one of <5>-<7> which stretches a thermoplastic resin film in extending | stretching temperature as 100 to 150 degreeC in a extending | stretching part. to be.

The process of <9> 2nd extending | stretching produces the thermoplastic resin film in any one of <5>-<8> which extends a thermoplastic resin film with extending | stretching temperature as 110 degreeC-140 degreeC in a extending | stretching part. to be.

It is a manufacturing method of the thermoplastic resin film in any one of <5>-<9> whose area magnification which is a product of the draw ratio in a <10> 1st draw and the draw ratio in a 2nd draw is 13.5 times-15.2 times.

<11> The process of performing a 2nd extending | stretching is <5>-<10 which expands a thermoplastic resin film in 0.0%-2.0% with respect to the film width at the time of completion | finish of heat relaxation in a heat relaxation part in a cooling part. It is a manufacturing method of the thermoplastic resin film in any one of>.

The process of <12> 1st extending | stretching is a manufacturing method of the thermoplastic resin film in any one of <5>-<11> which performs 1st extending | stretching whose draw ratio is 2 to 5 times with respect to a thermoplastic resin sheet.

According to one embodiment of the present disclosure, a thermoplastic resin film with less occurrence of wavy wrinkles is provided.

According to another embodiment of the present disclosure, even when a thin (preferably 200 µm or less) thermoplastic resin film is heated and conveyed, a method for producing a thermoplastic resin film in which wavy corrugation is less likely to occur is provided.

1 is a plan view illustrating an example of a biaxial stretching machine.
2 is a conceptual diagram for explaining a mechanism in which twist occurs due to the anisotropy of the elastic modulus of the film.
It is a front view for demonstrating the mechanism which twist generate | occur | produces in a film on a conveyance roll.
It is a front view which shows the state which the film twisted and buckled on the conveyance roll.

Hereinafter, the thermoplastic resin film of this indication and its manufacturing method are demonstrated in detail.

In this specification, the numerical range represented using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit. In the numerical range described step by step in this disclosure, the upper limit or the lower limit described in any numerical range may be replaced by the upper limit or the lower limit of the numerical range of the other staged description. Moreover, in the numerical range described in this indication, you may substitute the upper limit or lower limit described in the predetermined numerical range by the value shown in the Example.

In addition, in this specification, the term "process" is included in this term as long as the intended purpose of the process is achieved even if it is not only an independent process but also clearly distinguishable from other processes.

<Thermoplastic Film>

In the thermoplastic resin film of this indication, ratio Er30 in ³⁰ degreeC of the elasticity modulus E ^TD of the film width direction orthogonal to the film conveyance direction with respect to the elasticity modulus ^EMD of a film conveyance direction is 1.1-1.8, and also 30 degreeC non Er ^30, the maximum value is selected from a non-Er ¹⁸⁰ in the non-Er ^150, and 180 ℃ in non Er ^120, 150 ℃ in non Er ^90, 120 ℃ at 90 ℃ in the difference Er _max and Min Er _min 0.7 or less.

Further, Er ^{30, 90} Er, ¹²⁰ Er, ¹⁵⁰ Er Er and ¹⁸⁰ are as follows.

Er ³⁰ is, in the case where the film temperature of 30 ℃, represents the ratio of the elastic modulus E ^TD of the film in the width direction of the elastic modulus E ^MD in the film feed direction.

Er ⁹⁰ represents the ratio of the elastic modulus E ^TD in the film width direction to the elastic modulus E ^MD in the film conveyance direction when the film temperature is 90 ° C.

Er ¹²⁰ shows the ratio of the elastic modulus E ^TD of the film width direction with respect to the elastic modulus E ^MD of the film conveyance direction when a film temperature is 120 degreeC.

Er ¹⁵⁰ represents the ratio of the elastic modulus E ^TD in the film width direction with respect to the elastic modulus E ^MD in the film conveyance direction when the film temperature is 150 ° C.

Er ¹⁸⁰ represents the ratio of the elastic modulus E ^TD in the film width direction to the elastic modulus E ^MD in the film conveyance direction when the film temperature is 180 ° C.

"The maximum value Er _max and Min Er _min difference" ^{is, Er 30, Er 90, Er} 120, Er by selecting the maximum value Er _max and Min Er _min from ¹⁵⁰ and Er ^180, minus the Min Er _min from the maximum value Er _max Point.

In this disclosure, a thermoplastic resin film is also called simply "film", and the film whose thickness is 200 micrometers or less is also called "thin film." From a viewpoint that the effect by embodiment of this invention appears more, 100 micrometers or less are preferable and, as for the thickness of a thin film, 50 micrometers or less are more preferable.

Although the manufacturing method of a thermoplastic resin film is demonstrated in detail later, a thin film is obtained by conveying and extending | stretching using a roll etc. normally. Here, the conveyance direction of a film is also called MD (Machine Direction) direction. Moreover, MD direction of a film is also called the longitudinal direction of a film. Moreover, the width direction of a film is a direction orthogonal to the longitudinal direction of a film. The width direction of a film is also called TD (Transverse Direction) direction in the film manufactured, conveying a film.

In this specification, the conveyance direction of a film is called "MD" or "MD direction", and the width direction of the film orthogonal to the conveyance direction of a film is called "TD" or "TD direction".

A thermoplastic resin film may laminate | stack a some thermoplastic resin film, or a functional layer is laminated | stacked on a thermoplastic resin film, and high functionalization or complexation may be carried out. In the processing of such a thermoplastic resin film, stretching and heating of the film are usually performed while being conveyed by a roll or the like.

When the thin thermoplastic resin film is heated and conveyed, there is a tendency for wrinkles arranged in the uneven state to form a wavy shape in the TD direction of the thermoplastic resin film.

The following factors are considered for this phenomenon.

(1) The elastic modulus in the TD direction is smaller than the elastic modulus in the MD direction.

As described above, the thermoplastic film is conveyed by a roll or the like. The compressive stress acts in the TD direction by the Poisson effect by the stress acting in the MD direction such as the conveying tension at this time. When the elasticity modulus of the TD direction is small compared with the elasticity modulus of MD direction, since the generated compressive stress in the TD direction disturbs the shape of the TD direction of a film, it is thought that a distortion occurs in the TD direction of a film. That is, as shown in FIG. 2, when the polymer main chain (solid line in FIG. 2) is present in the MD direction and the molecular orientation in the MD direction is strong, the main chain is connected by side chains (dashed line in FIG. 2). In the TD direction, the shape holding force is weaker than that in the MD direction, and the anisotropy of the strength of the film is enhanced. For this reason, as for a film, it is estimated that wrinkle-like deformation | transformation tends to arise in a TD direction like FIG. On the contrary, in the case where the molecular orientation in the TD direction is strong (the polymer main chain is arranged in the TD direction), the molecular chain becomes resistance to deformation, and the film is considered to be less likely to cause wrinkle-like deformation in the TD direction. .

That is, it is estimated that the ratio of the elasticity modulus of the MD direction of a film and a TD direction can contribute to generation | occurrence | production of a wrinkle.

(2) The holding force in the TD direction edge part of the film by a conveyance roll is strong.

In the heating step, the film tends to swell in the width of the Z ¹ and Z ² in the end of the TD direction as shown in Fig. At this time, the conveyor roll (4) surface of the holding force of the TD both ends of the film (3) is strong, the expansion film 3 can not be moved in the TD direction, the stress σ _x of the expansion minutes the film thickness direction in the Is released. For this reason, the film 3 is considered to generate | occur | produce distortion in a TD direction, and it is thought that it buckles as shown in FIG. As a result, it is estimated that wrinkles appear in the TD direction of the film.

Since the roughness of the surface of the film also affects the holding force, it is estimated that it can contribute to the generation of wrinkles.

As mentioned above, the unevenness resulting from the wavy wrinkles which remain | survived in a film by solidifying by cooling a film in the state in which the wavy wrinkles generate | occur | produced in the TD direction of a film is called a streaky burr in this specification.

When a thermoplastic resin film has a stripe bur, some damage is easy to generate | occur | produce. As a bad effect, when it apply | coats a coating liquid on a film, it becomes difficult to apply | coat uniformly, the winding failure at the time of film winding (winding shift | offset | difference, winding wrinkle etc.), and functional layers, such as a lamination layer, on a film When affixing, the bubble enters between a film and a functional layer, etc. are mentioned.

The thin thermoplastic resin film is conventionally used for a magnetic tape etc., for example. Conventionally, the coating liquid which uses the organic solvent as a solvent is applied to the film generally, and the heating temperature with respect to the film required for removing a solvent by volatilization was low (for example, 100 degrees C or less). However, in recent years, there is a tendency to use an aqueous solvent (solvent containing water) for environmental protection, and the film is sometimes heated at a high temperature of about 150 ° C. to volatilize and remove the aqueous solvent. Moreover, the raw material (so-called film-making agent) hardened | cured by heating may be laminated | stacked on a film. In addition, when a film contains a film film, the film may be heated at 170 degreeC-180 degreeC.

In the case of heating the film as described above, wrinkles are more likely to occur in the film, and there are also situations in which the generation of striped burrs is more likely to appear remarkably than in the prior art.

Under the above circumstances, the generation of striped burrs was examined.

The stripe bur is considered to occur when the film is deformed into wrinkles due to thermal expansion due to the heating of the film and the tension at the time of conveying the film, and the film is fixed in the deformed state. The generation of striped burrs is a phenomenon that can occur anywhere in the heating step, specifically, in the film forming step, immediately after discharging the molten resin onto the cooling roll, stretching in the MD direction and stretching in the TD direction. This is a phenomenon that may occur after the annealing treatment for removing residual stress of the film, and after the drying treatment after applying the coating liquid on the film. Moreover, even if a stripe burr is not seen in the film after film forming, a stripe burr may appear by going through the subsequent annealing process or a drying process.

Conventionally, it is known to suppress wrinkle shape deformation by suppressing the conveyance tension at the time of film conveyance in each process in a manufacturing process. However, suppressing the conveyance tension has a trade-off relationship with maintaining good applicability, winding property, and the like, and a sufficient improvement effect cannot be expected by the control of the tension alone.

In addition, as described in, for example, Japanese Unexamined Patent Application Publication No. 2014-238612 and Japanese Unexamined Patent Publication No. 2014-210433, attempts have been made to improve the failure of wrinkles and the like by paying attention to the elastic modulus in one direction of the film surface. The inhibitory effect on the occurrence of the phase is not sufficient.

The thermoplastic resin film of this indication and its manufacturing method take the said circumstances into consideration.

The stripe burr generated due to heating is caused by being deformed and immobilized so that the film becomes wavy in the TD direction by the thermal expansion caused by the heating of the film and the tension applied to the film during conveyance. For this reason, in the thermoplastic resin film of this indication, the elastic modulus E ^TD of a TD direction is made high with respect to the elastic modulus E ^MD of an MD direction, and also the temperature dependence of elastic modulus E ^TD is suppressed small.

Specifically, the ratio Er ³⁰ at 30 ℃ of elastic modulus E ^TD of the elastic modulus E ^MD, to 1.1 ~ 1.8, and the addition ratio at the non-Er ^90, 120 ℃ in non Er ^30, 90 ℃ at 30 ℃ The difference between the maximum value Er _max and minimum value Er _min selected from Er ¹²⁰ , the ratio Er ¹⁵⁰ at 150 ° C., and the ratio Er ¹⁸⁰ at 180 ° C. is 0.7 or less.

In other words, when the polymer chains are arranged in the MD direction and the molecular orientation in the MD direction is strong, the anisotropy becomes stronger and twisting occurs in the TD direction, and the film is easily buckled and deformed, but the polymer chains are arranged in the TD direction and TD By strengthening the molecular orientation in the direction, the molecular chain becomes a resistance to deformation, and buckling of the film in the TD direction is less likely to occur. And when manufacturing a thermoplastic resin film, various heating temperatures are considered at the time of heat processing, and since the anisotropy of elastic modulus is small in the wide temperature range of 30 degreeC, 90 degreeC, 120 degreeC, 150 degreeC, and 180 degreeC, TD Buckling of the film in the direction is effectively suppressed.

Thereby, generation | occurrence | production of the wavy wrinkles (stripe burr) of a thermoplastic resin film is suppressed.

In the thermoplastic resin film of the present disclosure, the ratio Er ³⁰ at 30 ° C. of the elastic modulus E ^TD to the elastic modulus E ^MD is 1.1 to 1.8.

When Er ³⁰ is 1.1 or more, the molecular chain becomes a resistance to deformation and suppresses the buckling of the film, so that generation of striped burrs is suppressed. The larger the value of Er ³⁰ , the higher the suppression effect can be expected for the striped bur. In addition, by the Er ³⁰ to less than 1.8, it is not the case the molecular orientation in the TD direction that is excessively large, it is possible to suppress the breakage of the film.

As Er ³⁰ , for the same reason as above, 1.1-1.6 are preferable and 1.2-1.4 are more preferable.

The elastic modulus E ^MD of the film conveyance direction and the elastic modulus E ^TD of the film width direction can be adjusted by the balance between the draw ratios, the stretching speeds of MD stretching and TD stretching, and the balance between MD and TD. Moreover, in the cooling part of a 2nd extending process, it can also adjust by adjustment, such as the ratio which expands and expands | strengthens further in the width direction with respect to the film extended | stretched in the extending part.

In the thermoplastic resin film of this disclosure, it selects from ratio Er30 at ³⁰ degreeC, ratio Er90 at ⁹⁰ degreeC, ratio Er120 at ¹²⁰ degreeC, ratio Er150 at ¹⁵⁰ degreeC, and ratio Er ^{180 at 180} degreeC. The difference between the maximum value Er _max and the minimum value Er _min is 0.7 or less.

The difference between the maximum value Er _max and the minimum value Er _min indicates that the variation in the ratio of the elastic modulus at each temperature is suppressed. When the difference between the maximum value Er _max and the minimum value Er _min is 0.7 or less, molecular orientation is preferentially performed in the TD direction at any film temperature, and even if the heating temperature at the time of the heat treatment is a wide-ranging manufacturing process, the film in the TD direction Buckling is effectively suppressed.

The smaller the value, the smaller the difference between the maximum value Er _max and the minimum value Er _min is preferable. Specifically, 0.6 or less is preferable, 0.5 or less is more preferable, and 0.4 or less is more preferable.

The lower limit of the difference between the maximum value Er _max and the minimum value Er _min is, for example, 0.1.

Er ³⁰ , Er ⁹⁰ , Er ¹²⁰ , Er ¹⁵⁰ , and Er ¹⁸⁰ are each preferably in the following ranges from the viewpoint of suppressing the difference between the maximum value Er _max and the minimum value Er _min small.

As Er ⁹⁰ , 1.1-1.8 are preferable, 1.2-1.6 are more preferable, and 1.2-1.4 are more preferable.

As Er ¹²⁰ , 1.1-1.8 are preferable, 1.2-1.6 are more preferable, and 1.2-1.5 are more preferable.

As Er ¹⁵⁰ , 0.8-1.5 are preferable, 0.9-1.3 are more preferable, and 1.0-1.2 are more preferable.

As Er ¹⁸⁰ , 0.8-1.5 are preferable, 0.9-1.3 are more preferable, and 1.0-1.2 are more preferable.

The adjustment of the elastic modulus ratio at each temperature is performed by adjusting the draw ratio in the MD direction and the draw ratio in the TD direction, or in the step of stretching the film in the TD direction at the time of film production (second stretching step described later). This can be performed by adjusting the stretching speed (stretching ratio / second).

Ratio of the elastic modulus E ^TD of the film width direction orthogonal to the film conveyance direction with respect to the elastic modulus E ^MD of the film conveyance direction at each temperature of 30 degreeC, 90 degreeC, 120 degreeC, 150 degreeC, and 180 degreeC (Er = elasticity rate) E ^TD / elastic modulus E ^MD ) is a value obtained by the following method.

First, a sample piece is punched out from the film to be measured (width 6 x length 115 mm (JIS K 6251, dumbbell type 5)). The obtained sample piece was pulled under Tensileron (Toyo Seiki Co., Ltd., Straw Graph VE50) under a condition of 50 mm between the chuck and a tensile speed of 100 mm / min, and the elongation of the film with respect to the load was measured. From the measured values, a graph with the load as the horizontal axis and the height as the vertical axis is prepared, and the elastic modulus is calculated from the tangent of the rising part of the load-extension curve. This operation is performed five times, and the average value of three points except the maximum value and the minimum value is used as the elastic modulus. And it carries out about each case in the case of pulling in the film conveyance direction, and each case in the case of pulling in the film width direction with respect to each temperature.

Here, the elasticity modulus at the time of tension in the film conveyance direction is set to ^EMD , and the elasticity modulus at the time of tension in the film width direction is described as E ^TD .

<Measurement conditions>

Measuring place: hot air furnace

Measurement temperature: 30 ° C, 90 ° C, 120 ° C, 150 ° C, 180 ° C

(The set temperature of the furnace rises to a desired temperature in 1.5 minutes, and temperature setting and air volume adjustment are performed so that the temperature rise is within 2 ° C even if 1 minute has elapsed from the desired temperature.)

Temperature control: A test piece of the same size for measuring the temperature is provided near the test piece, a thermocouple is attached to the test piece for temperature measurement, and the temperature at the time of the measurement is monitored.

(The case where "the film temperature is 30 degreeC" means the case where the temperature of the test piece for temperature measurement is 30 degreeC. The case of other temperature is also the same.)

Test start timing: The tension is started after the desired temperature is reached.

It is preferable that surface roughness Ra of the surface of at least one of the thermoplastic resin films of this indication is 0.5 nm-50 nm.

If Ra is 0.5 nm or more, the sliding property in the surface of a conveyance roll can be improved, for example, and the improvement effect of a striped bur is excellent. Moreover, if Ra is 50 nm or less, it will become suitable for an optical use, without causing a malfunction to an external appearance.

Generally, although a thermoplastic resin film expands in a TD direction during a heating process, since the holding force in the conveyance roll surface in the TD direction edge part of a film is strong, and an expanded film cannot move to a TD direction, The stress is about to be released in the thickness direction. As a result, wrinkles are generated in a wavy shape in the TD direction, resulting in striped burs. In the thermoplastic resin film of this indication, generation | occurrence | production of the striped burr of a film can be suppressed by adjusting surface roughness Ra of a film to the said range.

Ra may be expected to reduce the stripe bur as the value is larger (ie, the rougher the surface). Among them, from the viewpoint of effectively reducing the striped burr while suppressing the influence on other properties, 0.8 nm to 30 nm is preferable, and 1 nm to 20 nm is more preferable for Ra.

Ra can be adjusted to a desired Ra value by adjusting the drawing speed (drawing ratio / second) or adjusting the drawing temperature in the step of stretching in the TD direction at the time of film production (second stretching step described later). Specifically, the value of Ra can be made large (roughening the surface) by, for example, increasing the stretching speed when stretching in the TD direction, decreasing the stretching temperature when stretching in the TD direction, and the like.

Ra is a value measured by the following method. In other words,

According to JIS B 0601: 2001, a contact shape measuring device (Mitutoyo FORMTRACER EXTREME CS-5000CNC) was measured 12 times at arbitrary positions with respect to the MD direction and the TD direction under the following conditions, and the minimum value of Ra and The average of 10 points in the MD direction and 10 points in the TD direction from which the maximum value is removed is determined, and the average value of 20 points is Ra.

<Condition>

Measuring needle tip diameter: 0.5 μm

Probe load: 0.75 mN

Measuring length: 0.8mm

Cutoff value: 0.08mm

As thickness of the thermoplastic resin film of this indication, the range of 200 micrometers or less is preferable.

In the case of a thin film having a thickness of 200 μm or less, in particular, wavy wrinkles in the TD direction due to heat treatment are likely to occur. Therefore, the effect by the thermoplastic resin film of this indication appears more when thickness is 200 micrometers or less.

As thickness of a thermoplastic resin film, the range of 100 micrometers or less is more preferable, The range of 80 micrometers or less is more preferable, The range of 50 micrometers or less is more preferable.

As a lower limit of the thickness of a thermoplastic resin film, it is 1 micrometer, for example.

The thickness of the thermoplastic resin film is measured at 50 mm intervals over the entire width of the TD direction of the film using a tactile film thickness meter (Mitutoyo ID-C112X). This operation is performed five sets at 1m intervals in the MD direction to make the average value of the measured values thickness.

Polyester, cyclic olefin resin, etc. are mentioned as raw material resin for forming the thermoplastic resin film of this indication.

As polyester, polyethylene terephthalate (PET) and polyethylene-2,6-naphthalate (PEN) are preferable, and PET is more preferable.

The cyclic olefin resin is a polymer resin having a cyclic olefin structure, and examples of the polymer resin having a cyclic olefin structure include (1) a norbornene polymer, (2) a polymer of a monocyclic cyclic olefin, and (3) a polymer of a cyclic conjugated diene. And (4) vinyl alicyclic hydrocarbon polymers, and the hydrides of (1) to (4).

-polyester-

Polyester is synthesize | combined by copolymerizing a dicarboxylic acid component and a diol component. Polyester can be obtained, for example, by carrying out the esterification reaction and / or transesterification reaction of (A) dicarboxylic acid component and (B) diol component by polycondensation of a reaction product. At this time, you may copolymerize a trifunctional or more than trifunctional polyfunctional monomer further. Moreover, polyester may contain terminal blockers, such as an oxazoline type compound, a carbodiimide compound, and an epoxy compound.

In addition, Paragraph 0051-064, Paragraph 0121-0124, and Paragraph 0087-0111 of Unexamined-Japanese-Patent No. 2014-189002 are described about the illustration and preferable aspect, such as a terminal sealant, a reaction catalyst, and the detail of polycondensation. Reference may be made.

As the dicarboxylic acid component, for example, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, dimer acid, eicoceindioic acid, pimelic acid, azelaic acid Alicyclic dicarboxylic acids such as aliphatic dicarboxylic acids such as methyl malonic acid and ethyl malonic acid, adamantane dicarboxylic acid, norbornene dicarboxylic acid, isosorbide, cyclohexanedicarboxylic acid, and decalindacarboxylic acid, terephthalic acid, isophthalic acid, Phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-di Aromatic dicarboxylic acid, such as phenyl ether dicarboxylic acid, 5-sodium sulfoisophthalic acid, phenyl indeni carboxylic acid, anthracene dicarboxylic acid, phenanthrene dicarboxylic acid, and 9,9'-bis (4-carboxyphenyl) fluorene acid, etc. There may be mentioned a carboxylic acid or its ester derivative.

As the (B) diol component, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butanein Aliphatic diols such as ol, 1,3-butanediol, cyclohexanediethanol, spiroglycol, isosorbide, and other alicyclic diols, bisphenol A, 1,3-benzenedimethanol, 1 And diol compounds such as aromatic diols such as, 4-benzenedimethanol and 9,9'-bis (4-hydroxyphenyl) fluorene.

As the (A) dicarboxylic acid component, at least one of aromatic dicarboxylic acids is preferably used. More preferably, aromatic dicarboxylic acid is contained as a main component among dicarboxylic acid components. Dicarboxylic acid components other than aromatic dicarboxylic acid may also be included. Examples of such dicarboxylic acid components include ester derivatives such as aromatic dicarboxylic acids.

In addition, a "main component" means that the ratio of the aromatic dicarboxylic acid to a dicarboxylic acid component is 80 mass% or more.

As the diol component (B), at least one kind of aliphatic diol is preferably used. The aliphatic diol may include ethylene glycol, and preferably contains ethylene glycol as a main component.

In addition, a main component means that the ratio of the ethylene glycol to a diol component is 80 mass% or more.

The amount of the diol component is preferably in the range of 1.015 mol to 1.50 mol, more preferably 1.02 mol to 1.30 mol, and more preferably 1.025 mol relative to the dicarboxylic acid component and, if necessary, 1 mol of the ester derivative. ~ 1.10 moles. If the amount of the diol component is 1.015 or more, the esterification reaction proceeds well. Moreover, when the quantity of a diol component is 1.50 mol or less, the by-product of diethylene glycol by the dimerization of ethylene glycol is suppressed, for example, the said melting | fusing point, glass transition temperature, crystallinity, heat resistance, and water resistance Characteristics such as degradability and weather resistance can be maintained well.

It is preferable that raw material resin contains the polyfunctional monomer whose sum total (a + b) of the number (a) of a carboxylic acid group and the number (b) of a hydroxyl group is three or more as a copolymerization component. "The raw material resin contains a polyfunctional monomer as a copolymerization component" means that the raw material resin includes a structural unit derived from the polyfunctional monomer.

As a structural unit derived from the polyfunctional monomer whose total (a + b) of the number (a) of a carboxylic acid group and the number (b) of a hydroxyl group is three or more, the structural unit derived from the carboxylic acid shown below is mentioned.

As an example of the carboxylic acid (that is, polyfunctional monomer) whose number (a) of carboxylic acid group is three or more, As trifunctional aromatic carboxylic acid, For example, trimesic acid, trimellitic acid, pyromellitic acid, naphthalene tricarboxylic acid, anthracene A carboxylic acid etc. are mentioned, As trifunctional aliphatic carboxylic acid, methane tricarboxylic acid, ethane tricarboxylic acid, propane tricarboxylic acid, butane tricarboxylic acid, etc. are mentioned, for example, As a tetrafunctional aromatic carboxylic acid, it is mentioned, for example. For example, benzene tetracarboxylic acid, benzophenone tetracarboxylic acid, naphthalene tetracarboxylic acid, anthracene tetracarboxylic acid, perylene tetracarboxylic acid, etc. are mentioned, As a tetrafunctional aliphatic carboxylic acid, For example, ethane tetracarboxylic acid, ethylene tetracarboxylic acid, butane tetracarboxylic acid , Cyclopentane tetracarboxylic acid, cyclohexane Tracarboxylic acid, adamantane tetracarboxylic acid, etc. are mentioned, As an aromatic carboxylic acid more than 5 functional, for example, benzene pentacarboxylic acid, benzene hexacarboxylic acid, naphthalene pentacarboxylic acid, naphthalene hexacarboxylic acid, naphthaleneheptacarboxylic acid, naphthalene octacarboxylic acid, anthracene octacarboxylic acid, anthracene pentacarboxylic acid Carboxylic acid, anthracene hexacarboxylic acid, anthraceneheptacarboxylic acid, anthraceneoctacarboxylic acid, and the like. Examples of the 5-functional or more aliphatic carboxylic acid include ethanepentacarboxylic acid, ethaneheptacarboxylic acid, butanepentacarboxylic acid, butaneheptacarboxylic acid, and cyclopentane. Pentacarboxylic acid, cyclohexane pentacarboxylic acid, cyclohexane hexacarboxylic acid, adamantane pentacarboxylic acid, adamantane hexacarboxylic acid, etc. are mentioned.

Although these ester derivatives, acid anhydrides, etc. are mentioned as an example of the carboxylic acid (namely, polyfunctional monomer) whose number (a) of carboxylic acid group is three or more, It is not limited to these.

Moreover, as carboxylic acid (that is, a polyfunctional monomer) whose number (a) of carboxylic acid group is three or more, oxyacids, such as l-lactide, d-lactide, and hydroxybenzoic acid, and its derivative (s) at the carboxy terminal of the above-mentioned carboxylic acid, It is also suitably used to add a plural number of the oxyacids.

As an example of the polyfunctional monomer whose hydroxyl number (b) is three or more, As a trifunctional aromatic compound, For example, trihydroxy benzene, trihydroxy naphthalene, trihydroxy anthracene, trihydroxy chalcone, trihydroxy flavone, Trihydroxy coumarin is mentioned, As a trifunctional aliphatic alcohol, For example, glycerin, a trimethylol propane, propane triol is mentioned, As a tetrafunctional aliphatic alcohol, For example, pentaerythritol Can be mentioned. Moreover, as a polyfunctional monomer whose hydroxyl number (b) is three or more, the compound which added diols to the hydroxyl group terminal of the compound mentioned above is also used preferably.

These may be used individually by 1 type and may use multiple types together as needed.

Moreover, as another polyfunctional monomer other than the above, oxyacids which have both a hydroxyl group and a carboxylic acid group in 1 molecule, and the sum (a + b) of the number (a) of a carboxylic acid group and the number (b) of a hydroxyl group is three or more. Also can be mentioned. Examples of the oxyacids include hydroxyisophthalic acid, hydroxy terephthalic acid, dihydroxy terephthalic acid, trihydroxy terephthalic acid and the like. Moreover, as another polyfunctional monomer, what added oxy acids, such as l-lactide, d-lactide, and hydroxy benzoic acid, its derivative (s), the thing connected with two or more oxy acids, etc. to the carboxy terminal of a polyfunctional monomer is also used. It is suitably used.

As for the content rate in the raw material resin of the structural unit derived from a polyfunctional monomer, 0.005 mol%-2.5 mol% are preferable with respect to all the structural units in raw material resin. The content rate of the structural unit derived from a polyfunctional monomer becomes like this. More preferably, it is 0.020 mol%-1 mol%, More preferably, it is 0.05 mol%-0.5 mol%.

When the structural unit derived from the trifunctional or more than trifunctional polyfunctional monomer exists in raw material resin, when the polyester film was shape | molded, the component and hydrogen in the coating layer which the functional group which was not used for polycondensation apply | coated and formed on the polyester film By bonding and covalently bonding, the adhesiveness of an application layer and a polyester film is maintained more favorable, and generation | occurrence | production of peeling can be prevented effectively. Moreover, the structure which the polyester molecular chain branched from the structural unit derived from a trifunctional or more than trifunctional polyfunctional monomer is obtained, and entanglement between polyester molecules can be promoted.

A conventionally well-known reaction catalyst can be used for esterification reaction and / or transesterification reaction. Examples of the reaction catalyst include alkali metal compounds, alkaline earth metal compounds, zinc compounds, lead compounds, manganese compounds, cobalt compounds, aluminum compounds, antimony compounds, titanium compounds, and phosphorus compounds. Usually in any step before the process for producing the polyester is completed, it is preferred to add an antimony compound, a germanium compound, a titanium compound as the polymerization catalyst. As such a method, it is preferable to add a germanium compound powder as it is, for example, as a germanium compound.

When the thermoplastic resin film is a polyester film, the intrinsic viscosity (IV; Intrinsic Viscosity) of the polyester film is 0.55 dL / g or more and 0.90 dL / g or less from the viewpoint of improving the hydrolysis resistance of the polyester film and improving weather resistance. It is preferable that it is 0.60 dL / g or more and 0.80 dL / g or less, It is more preferable that it is 0.62 dL / g or more and 0.78 dL / g or less.

Intrinsic viscosity (IV) is the value obtained by dividing the specific viscosity (η _sp = η _r −1) minus 1 by the ratio η _r (= η / η ₀ ; relative viscosity) of the solution viscosity η and the solvent viscosity η ₀ by the concentration. It is the value which extrapolated in the state of zero concentration. IV melt | dissolves polyester in a 1,1,2,2- tetrachloroethane / phenol (= 2/3 [mass ratio]) mixed solvent using an uvelode-type viscometer, and is calculated | required from the solution viscosity of 25 degreeC. .

When the thermoplastic resin film is a polyester film, the amount of the terminal carboxy group of the polyester film [terminal COOH amount (also called acid value), AV; Acid Value] is preferably 5 eq / ton or more and 35 eq / ton or less. As for the amount of terminal COOH, 6 eq / ton or more and 30 eq / ton or less are more preferable, and 7 eq / ton or more and 28 eq / ton or less are more preferable.

In addition, in this specification, "eq / ton" shows the molar equivalent per ton.

AV is completely dissolved in a mixed solution of benzyl alcohol / chloroform (= 2/3; volume ratio), titrated with a reference solution (0.025 N KOH-methanol mixed solution) using phenol red as an indicator, It is a value calculated from the appropriate amount.

Cyclic olefin resin

As an example of cyclic olefin resin, At least 1 or more of the addition (co) polymer cyclic polyolefin containing at least 1 or more types of repeating units represented by the following general formula (II), and the following represented by the following general formula (I) as needed The addition (co) polymer cyclic polyolefin which further contains is mentioned. Moreover, as an example of cyclic olefin resin, the ring-opening (co) polymer containing at least 1 sort (s) of the cyclic repeating unit represented by the following general formula (III) is also mentioned suitably.

[Formula 1]

In the formula (I), (II), and (III), m represents an integer of ^{0 ~ 4, R 1 ~ R} 6 are each independently represent a hydrogen atom or a hydrocarbon of a carbon number of 1 ~ 10, X ¹ to X ³ and Y ¹ to Y ³ are each independently a hydrogen atom, a hydrocarbon group of 1 to 10 carbon atoms, a halogen atom, a hydrocarbon group of 1 to 10 carbon atoms substituted with a halogen atom, and-(CH ₂ ) _n COOR ¹¹ ,-(CH ₂ ) _n OCOR ¹² ,-(CH ₂ ) _n NCO,-(CH ₂ ) _n NO ₂ ,-(CH ₂ ) _n CN,-(CH ₂ ) _n CONR ¹³ R ¹⁴ ,-( CH ₂ ) _n NR ¹³ R ¹⁴ , — (CH ₂ ) _n OZ, or — (CH ₂ ) _n W. In addition, X ¹ and Y ¹ , X ² and Y ² , or X ³ and Y ³ may be bonded to each other to form (-CO) ₂ O or (-CO) ₂ NR ¹⁵ . Here, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, Z represents a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p D _3-p is represented, and n represents an integer of 0 to 10. D represents a halogen atom, -OCOR ¹⁶ or -OR ¹⁶ , R ¹⁶ represents a hydrocarbon group having 1 to 10 carbon atoms, and p represents an integer of 0 to 3;

By introducing a highly polarizable functional group into all or part of the substituents of X ¹ to X ³ and Y ¹ to Y ³ , the thickness direction retardation (Rth) of the optical film is increased to express the in-plane retardation (Re). Can be increased. The film with large Re expressionability can enlarge Re value by extending | stretching in a film forming process.

Norbornene-based addition (co) polymers are disclosed in JP-A-10-007732, JP-A-2002-504184, JP-A-2004 / 229157A1, JP-A-2004 / 070463A1, and the like. . A norbornene-based addition (co) polymer can be obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. Moreover, a norbornene-type addition (co) polymer is a norbornene-type polycyclic unsaturated compound, ethylene, propylene, butene if needed; Conjugated dienes such as butadiene and isoprene; Non-conjugated dienes such as ethylidene norbornene; You may obtain by addition-polymerizing linear diene compounds, such as acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate, and vinyl chloride.

As a norbornene-type addition (co) polymer on the market, for example, Apel (trade name; glass transition temperature (Tg) from Mitsui Chemicals, Inc.) differs, for example, APL8008T (Tg: 70 ° C), APL6013T (Tg: 125 ° C). Or APL6015T (Tg: 145 ° C.), pellets such as TOPAS8007, 6013, 6060, and 6015 manufactured by Poly Plastics, Inc., and Appear3000 manufactured by Ferrania.

Norbornene-based polymer hydrides are disclosed in Japanese Patent Application Laid-Open No. Hei 1-240517, Japanese Patent Application Laid-Open No. 7-196736, Japanese Patent Application Laid-Open No. 60-026024, Japanese Patent Application Laid-open No. 62-019801, and Japanese Patent Application Laid-Open. As disclosed in each publication, such as Unexamined-Japanese-Patent No. 2003-159767 or Unexamined-Japanese-Patent No. 2004-309979, it can manufacture by carrying out addition polymerization or metathesis ring-opening polymerization, and then hydrogenating.

In norbornene-based polymers, in general formula (III), R ⁵ to R ⁶ are preferably a hydrogen atom or -CH ₃ , X ³ and Y ³ are preferably a hydrogen atom, Cl, or -COOCH ₃ , and others The group is appropriately selected.

Examples of norbornene-based resins on the market include Arton G or Aton F (trade name) of JSR Corporation, Zeonor ZF14, ZF16, Zeonex 250, or Zeonex 280 (trade name) of Nippon Xeon Corporation. ), And the like.

<The manufacturing method of a thermoplastic resin film>

The thermoplastic resin film of the present disclosure may be produced by any method as long as the difference between the ratio Er ³⁰ , the maximum value Er _max, and the minimum value Er _min described above satisfies a predetermined range. The thermoplastic resin film of this indication is produced suitably by the manufacturing method of the thermoplastic resin film of this indication shown below.

Hereinafter, the manufacturing method of the thermoplastic resin film of this indication is demonstrated in detail.

The manufacturing method of the thermoplastic resin film of this indication is the process of melt-extruding a raw material resin, cooling, and shape | molding a thermoplastic resin sheet (henceforth a "molding process"), and a longitudinal direction (MD) with respect to a thermoplastic resin sheet. The process of obtaining a thermoplastic resin film by carrying out 1st extending | stretching (henceforth "a 1st extending process"), a preheating part which preheats a thermoplastic resin film, and a preheated thermoplastic resin film are orthogonal to the longitudinal direction of a thermoplastic resin film Stretching part which stretches by stretching in the film width direction, the heat-opening part which heats and heats the thermoplastic resin film by which tension was applied, and the heat-relaxing part which heat-relaxs the said tension, and cooling which cools a heat-relaxed thermoplastic resin film It includes a step (hereinafter also referred to as "second stretching process") of sequentially conveying said thermoplastic resin film to a part and performing a 2nd extending | stretching,

The stretching ratio in the second stretching is large with respect to the stretching ratio in the first stretching, and the area magnification which is the product of the stretching ratio in the first stretching and the stretching ratio in the second stretching is 12.8 times to 15.5 times,

The process of performing 2nd extending | stretching further gives tension to a film width direction in a cooling part, and expands in the range of -1.5%-3% with respect to the film width at the time of completion | finish of heat relaxation in a heat relaxation part, or Zoom out. For example, "-1.5%" means "reduction of 1.5%".

In the manufacturing method of the thermoplastic resin film of this indication, when extending | stretching 1st to a thermoplastic resin sheet to MD direction, and performing 2nd extending | stretching further to a TD direction after that, to produce a biaxially stretched film, The stretching ratio in the second stretching is increased with respect to the stretching ratio, and in addition to setting the area magnification, which is the product of the stretching ratio in the first stretching and the stretching ratio in the second stretching, to 12.8 times to 15.5 times, the second stretching is performed. In the step of performing, the cooling portion after the stretching portion has already been tensioned and stretched in the film width direction, and further the tension in the film width direction is applied to the film width at the end of heat relaxation in the thermal relaxation portion. Expand or contract in the range of -1.5% to 3%. As in the above, for example, "-1.5%" means "reduction of 1.5%".

Thereby, the thermoplastic resin film by which generation | occurrence | production of a wavy wrinkle (stripe burr) was suppressed is obtained.

The manufacturing method of the thermoplastic resin film of this indication contains the shaping | molding process, the 1st extending process, and the 2nd extending process at least as mentioned above, and may further contain another process. Moreover, 1st extending | stretching means extending | stretching to the longitudinal direction (MD direction) of a film, and 2nd extending | stretching means extending | stretching to the width direction (TD direction) of a film.

In the manufacturing method of the thermoplastic resin film of this indication, a 2nd extending process is performed by conveying a thermoplastic resin film sequentially in a preheating part, a extending | stretching part, a heat part, a heat relaxation part, and a cooling part.

Below, each process in the manufacturing method of the thermoplastic resin film of this indication is demonstrated in detail.

Molding process

In the shaping | molding process in the manufacturing method of this indication, a raw material resin is melt-extruded, cooled, and a thermoplastic resin sheet is shape | molded.

Molding of a thermoplastic resin sheet is performed by injecting a raw material resin and cooling the thermoplastic resin melt-extruded to the sheet form on the casting roll.

Although the method of melt-extruding raw material resin and raw material resin is not specifically limited, Intrinsic viscosity can be made into a desired intrinsic viscosity by the catalyst used for the synthesis | combination of raw material resin, a polymerization method, etc.

The detail of raw material resin is as above-mentioned.

(Melt extrusion)

In the molding step, the raw resin is melt-extruded and then subjected to cooling to form a thermoplastic resin sheet.

Melt extrusion of raw material resin is performed, for example using the extruder provided with one or two or more screws, heating to the temperature more than melting | fusing point of raw material resin, rotating a screw, and melt-kneading. The raw material resin is melted in an extruder by heating and kneading with a screw to form a molten resin (also called a melt). Moreover, from a viewpoint of suppressing thermal decomposition (for example, hydrolysis of polyester) in an extruder, it is preferable to nitrogen-substitute inside the extruder and perform melt extrusion of raw material resin. The extruder is preferably a twin screw extruder because the kneading temperature is kept low.

The molten molten resin (melt) is extruded from the extrusion die through a gear pump, a filter, or the like. The extrusion die is also referred to simply as the "die". [JIS B 8650: 2006, a) Extrusion Machine, No. 134]

The melt may be extruded in a single layer or may be extruded in multiple layers.

When polyester is used as the raw material resin and the terminal resin is further included in the raw material resin, in the molding step, the polyester raw material resin to which the terminal sealant is added is melt-kneaded, and the poly-reaction with the terminal sealant during the melt kneading is performed. The ester raw material resin is melt-extruded.

When melt-extruding and cooling raw material resin, you may shape | mold to a sheet form (namely, cast process) by extruding molten resin (melt) from a die on a casting roll.

When extruding the melt from the die, applying a method such as the electrostatic application method, the air knife method, the air chamber method, the vacuum nozzle method, the touch roll method, etc. on the casting roll to increase the adhesion between the casting roll and the melt-extruded sheet. desirable. Especially, when using the polymer resin which has a cyclic olefin structure as raw material resin, it is preferable to improve the adhesiveness of a casting roll and a sheet by a touch roll method, for example. The touch roll method is a method of placing a touch roll on a casting roll and shaping the surface of a sheet. The touch roll is preferably a roll having elasticity instead of a normal roll having high rigidity.

As temperature of a touch roll, when the glass transition temperature of a melt-extruded sheet is made into Tg, more than (Tg-10 degreeC) (Tg + 30 degreeC) or less is preferable, (Tg-7 degreeC)-(Tg + 20 degreeC) It is more preferable, and (Tg-5 degreeC)-(Tg + 10 degreeC) are more preferable. The temperature range of the casting roll is also preferably the same.

As an example of a touch roll, the touch roll of Unexamined-Japanese-Patent No. 11-314263 or Unexamined-Japanese-Patent No. 11-235747 is mentioned.

0.1 mm-3 mm are preferable, as for the thickness of the sheet-like molded object (thermoplastic resin sheet) obtained by the cast process, 0.2 mm-2 mm are more preferable, 0.3 mm-1.5 mm are more preferable.

If the thickness of the thermoplastic resin sheet is 3 mm or less, the cooling delay due to heat storage of the melt can be avoided. If the thickness of the thermoplastic resin sheet is 0.1 mm or more, the hydroxyl groups and carboxyl groups in the thermoplastic resin sheet (preferably polyester sheet) diffuse into the thermoplastic resin (preferably polyester) from extrusion to cooling. The exposure of the hydroxyl group and the carboxy group, which are the causes of hydrolysis, to the resin surface is suppressed.

The means for cooling the melt extruded from the extrusion die is not particularly limited, and may be any of applying cold air to the melt, contacting the casting roll, spraying water, and the like. The means for cooling the melt may be implemented in any one means or in combination of two or more means.

The means for cooling the melt is preferably at least one of cooling by cold air and cooling with a casting roll, from the viewpoint of preventing oligomer adhesion to the film surface during continuous operation. Furthermore, it is particularly preferable to cool the melt extruded from the extruder by cold wind and to cool the melt by contacting the casting roll.

Moreover, the thermoplastic resin sheet cooled using the casting roll etc. is peeled from cooling members, such as a casting roll, using peeling members, such as a peeling roll.

First drawing process

In the 1st extending process in the manufacturing method of this indication, 1st extending | stretching (henceforth "longitudinal stretching" suitably) is performed to the longitudinal direction (MD direction) with respect to the thermoplastic resin sheet shape | molded at said shaping | molding process, Obtain a thermoplastic resin film.

2nd which the 1st extending | stretching arranged in the conveyance direction of a thermoplastic resin sheet, conveying a thermoplastic resin sheet to the longitudinal direction of a thermoplastic resin sheet through a thermoplastic resin sheet, for example to a pair of nip rolls which sandwich a thermoplastic resin sheet. This can be done by providing tension between the pair of nip rolls or more. Specifically, for example, when a pair of nip rolls A are provided on the conveyance direction upstream side of the thermoplastic resin sheet and a pair of nip rolls B on the downstream side, when conveying the thermoplastic resin sheet, the nip roll B on the downstream side The thermoplastic resin sheet is stretched in a conveyance direction (MD direction) by making the rotational speed of into quicker than the rotational speed of the nip roll A of an upstream. In addition, you may respectively provide two or more pairs of nip rolls in each of an upstream and a downstream side. Moreover, you may perform the 1st extending | stretching of a thermoplastic resin sheet using the extending | stretching apparatus provided with the nip roll.

It is preferable that the draw ratio at the time of the 1st drawing of the thermoplastic resin sheet in a 1st extending process is adjusted smaller than the draw ratio in the 2nd drawing in the 2nd extending process mentioned later. Although the elasticity modulus at normal temperature becomes high, so that the draw ratio by 1st extending | stretching is large, it is easy to relax by heating and it becomes easy to lower an elasticity modulus when reheating by heat processing etc. For this reason, by making the draw ratio by a 1st draw smaller than the draw ratio by a 2nd draw in a TD direction, in other words, by extending the draw ratio by a 2nd draw with respect to the draw ratio by a 1st draw, It is easy to obtain the thermoplastic resin film in which generation | occurrence | production of the stripe burr derived from wavy corrugation was suppressed.

As a draw ratio of the thermoplastic resin sheet in a 1st extending process, 2 times-5 times are preferable, 2.5 times-4.0 times are more preferable, 2.8 times-3.5 times are more preferable.

Moreover, as an area magnification represented by the product of the draw ratio of 1st draw and the draw ratio of 2nd draw, it becomes 12.8 times-15.5 times of the area of the thermoplastic resin sheet before 1st draw and 2nd draw are performed.

The larger the area magnification is, the higher the elastic modulus at room temperature is, but the elastic modulus in this case tends to be alleviated by heating, and the elastic modulus tends to be lowered when reheated by heat treatment or the like. In the present disclosure, when the area magnification is 12.8 times or more, since the molecular orientation in the film width direction becomes good, the generation of the striped bur is effectively suppressed. Moreover, when area magnification is 15.5 times or less, it is easy to maintain the state which molecular orientation hardly relieves when it is provided to heat processing.

13.5 times-15.2 times are preferable, and, as for an area magnification, 14.0 times-15.0 times are more preferable.

As for the temperature at the time of the 1st extending | stretching of a thermoplastic resin film, when the glass transition temperature of a thermoplastic resin film is Tg, (Tg-20 degreeC)-(Tg + 50 degreeC) are preferable, More preferably, it is (Tg-10 degreeC) ) To (Tg + 40 ° C), and more preferably (Tg ° C) to (Tg + 30 ° C).

Moreover, when extending | stretching using rolls, such as a nip roll, as a means of heating a thermoplastic resin film, the thermoplastic resin film which contact | connects a roll can be heated by providing the piping which can flow a heater and a warm solvent inside a roll. Can be. Moreover, even when a roll is not used, a thermoplastic resin film can be heated by injecting warm air into a thermoplastic resin film, making it contact a heat source, such as a heater, or passing near a heat source.

The manufacturing method of the thermoplastic resin film of this indication further includes the 2nd extending process of extending | stretching a film to a TD direction after a 1st extending process. Thereby, in the manufacturing method of the thermoplastic resin film of this indication, a thermoplastic resin film is extended | stretched at least biaxially among the longitudinal direction (MD) of a thermoplastic resin film, and the film width direction (TD) orthogonal to the longitudinal direction of a thermoplastic resin film. Done. Stretching in the MD direction and the TD direction may be performed at least once each.

The "film width direction (TD) orthogonal to the longitudinal direction (MD) of the thermoplastic resin film" is intended to mean a direction perpendicular to the longitudinal direction (MD) of the thermoplastic resin film (90 °), but a mechanical error. The direction from which the angle with respect to the longitudinal direction MD is considerably 90 degrees from the back etc. (for example, the direction of 90 degrees +/- 5 degrees with respect to MD direction) is included.

In the present disclosure, as a method of biaxial stretching, the first stretching (longitudinal stretching) and the second, in addition to the sequential biaxial stretching method in which the first stretching (longitudinal stretching) and the second stretching (lateral stretching) described later are performed separately. Any of the simultaneous biaxial stretching methods which simultaneously perform stretching (lateral stretching) may be used. You may perform 1st extending | stretching and 2nd extending | stretching twice or more independently, respectively. Longitudinal stretching and lateral stretching can suppress generation | occurrence | production of a wavy wrinkle, even if it performs any one earlier, As an aspect of biaxial stretching, for example, longitudinal stretch → lateral stretch, longitudinal stretch → lateral stretch → longitudinal stretch, longitudinal stretch Stretching aspect, such as → longitudinal stretch → lateral stretch, lateral stretch → longitudinal stretch, is mentioned. Especially, as an aspect of biaxial stretching, from the point of easiness of manufacture, ie, aptitude for manufacture, like longitudinal manufacturing → transverse stretching is preferable like the manufacturing method of this indication.

Second Stretching Process

In the 2nd extending process in the manufacturing method of this indication, the preheating part which preheats the stretched thermoplastic resin film, and the preheated thermoplastic resin film to the thermoplastic resin film which 1st extending | stretched was performed in said 1st extending process, Stretching part which stretches and extends | stretches and stretches in the film width direction orthogonal to the longitudinal direction of a thermoplastic resin film, The heat-opening part which heats and heats a thermoplastic resin film to which tension was given, and the heat relaxation part which heat-relaxs the said tension, And heat It conveys sequentially to the cooling part which cools the relaxed thermoplastic resin film, and further gives tension to the said film width direction in the said cooling part, and -1.5 with respect to the film width at the time of completion | finish of heat relaxation in a heat relaxation part. Expands or contracts in the range of% to 3%. Thereby, 2nd extending | stretching (henceforth "lateral stretching" suitably) is implemented. Here, for example, "-1.5%" means "reduction of 1.5%".

A 2nd extending process is a process of performing 2nd extending | stretching (lateral stretching) in the film width direction orthogonal to a longitudinal direction of the thermoplastic resin film after 1st extending | stretching (longitudinal stretching), and specifically, 2nd extending | stretching (lateral stretching) A thermoplastic resin film can be conveyed and performed sequentially to the following (a)-(e).

(a) a preheating part for preheating the thermoplastic resin film after longitudinal stretching to a stretchable temperature,

(b) a drawing portion for stretching the preheated thermoplastic resin film by applying tension to the film width direction perpendicular to the longitudinal direction;

(c) a heat-setting unit for crystallizing and heat setting the thermoplastic resin film after longitudinal stretching and lateral stretching by heating,

(d) a heat relaxation part for heating the heat-set thermoplastic resin film and thermally relaxing the tension of the thermoplastic resin film to remove residual distortion of the film;

(e) cooling the thermoplastic resin film after thermal relaxation and at the same time giving tension in the film width direction and expanding or expanding in the range of -1.5% to 3% with respect to the film width at the end of thermal relaxation in the thermal relaxation part; Reduced cooling section

In (e) cooling part in the 2nd extending process of the manufacturing method of this indication, after extending | stretching to the film width direction (TD) in (b) extending | stretching part, tension is further added to a film width direction, and a heat relaxation part The thermoplastic resin film is expanded or reduced in the range of -1.5% to 3% with respect to the film width at the end of thermal relaxation at.

In the cooling part, the synergistic effect of the modulus of elasticity in TD is assuming that the expansion ratio or reduction ratio in the TD direction of the thermoplastic resin film is -1.5% or more with respect to the film width at the end of thermal relaxation in the thermal relaxation portion. Easy to get Moreover, when the expansion ratio or reduction ratio in the TD direction of a thermoplastic resin film is 3% or less with respect to the film width at the time of completion | finish of heat relaxation in a heat relaxation part, it is effective for suppressing break of a film.

Although the elasticity modulus under normal temperature becomes high, so that area magnification and the draw ratio at the time of 2nd extending | stretching become large, it is easy to relieve by heat and the fall of the elasticity modulus by heat processing tends to occur. For this reason, in the manufacturing method of this indication, while restraining the raise of the area magnification by the 1st extending | stretching and the 2nd extending | stretching, forcibly redrawing | stretching the film which crystallized through heat setting to improve elastic modulus while suppressing relaxation It becomes possible.

In the above, as the expansion ratio or the reduction ratio in the TD direction of the thermoplastic resin film in the cooling unit, for the same reason as above, 0.0% to 2.0 with respect to the film width at the end of the thermal relaxation in the thermal relaxation unit. % Is more preferable, and 1.5%-1.8% are more preferable.

In the present disclosure, the term "end time of heat relaxation in the heat relaxation part" means that the speed at which the thermoplastic resin film shrinks in the width direction when the thermoplastic resin film enters the cooling part, that is, when the residual stress is relaxed. Point in time.

In the 2nd stretching process, if the thermoplastic resin film is lateral stretched by the said structure, the specific means is not restrict | limited, It is preferable to carry out using the lateral stretching apparatus or biaxial stretching machine which can process each process which comprises the said structure. .

2-axis drawing machine

As illustrated in FIG. 1, the biaxial stretching machine 100 includes a pair of annular rails 60a and 60b and gripping members 2a to 2l mounted to each annular rail and movable along the rail. have. The annular rails 60a and 60b are symmetrically disposed with the thermoplastic resin film 200 interposed therebetween, and the film width is obtained by holding the thermoplastic resin film 200 with the gripping members 2a to 2l and moving them along the rail. Stretching is possible in the direction.

The biaxial stretching machine 100 orthogonally crosses the preheating unit 10 for preheating the thermoplastic resin film 200 and the preheated thermoplastic resin film 200 with the direction (length direction) of the arrow MD of the thermoplastic resin film. The stretching section 20 which stretches by stretching in the direction of the arrow TD (film width direction), which is a direction, and the heat-setting unit 30 which heats and heats and heats while applying tension to the thermoplastic resin film to which the tension is applied, and heat-setting It consists of a region including a heat-relaxing portion 40 for heat-relaxing the tension of the thermoplastic resin film heat-set by heating the thermoplastic resin film, and a cooling unit 50 for cooling the heat-relaxed thermoplastic resin film through the heat-relaxing portion. have.

Holding members 2a, 2b, 2e, 2f, 2i, and 2j movable along the annular rail 60a are attached to the annular rail 60a, and the annular rail 60b is attached to the annular rail 60b. Holding members 2c, 2d, 2g, 2h, 2k, and 2l which are movable along the surface thereof are mounted. The holding members 2a, 2b, 2e, 2f, 2i, and 2j hold one end portion in the TD direction of the thermoplastic resin film 200, and the holding members 2c, 2d, 2g, 2h, 2k, and 2l. ) Grips the other end of the thermoplastic resin film 200 in the TD direction. The holding members 2a-2l are generally called chucks, clips, or the like.

The holding members 2a, 2b, 2e, 2f, 2i, and 2j move counterclockwise along the annular rail 60a, and the holding members 2c, 2d, 2g, 2h, 2k, and 2l, It moves clockwise along the annular rail 60b.

The holding members 2a to 2d hold the end portions of the thermoplastic resin film 200 in the preheating unit 10 and move along the annular rails 60a or 60b while being held, and thus the stretching unit 20, It advances to the cooling part 50 in which the holding members 2i-2l are located through the heat relaxation part 40 in which the holding members 2e-2h are located. Thereafter, the holding members 2a and 2b and the holding members 2c and 2d separated the ends of the thermoplastic resin film 200 at the ends on the MD-direction downstream side of the cooling unit 50 in the conveying direction order. Then, it moves along the annular rail 60a or 60b, and returns to the preheating part 10 further. At this time, the thermoplastic resin film 200 moves in the direction of the arrow MD, and is sequentially preheated in the preheating unit 10, stretching in the stretching unit 20, heat setting in the heat setting unit 30, and heat relaxation unit. Thermal relaxation at 40 and cooling at cooling section 50 are performed, and laterally stretched. The moving speed in each area | region, such as the preheating part of the holding members 2a-2l, becomes the conveyance speed of the thermoplastic resin film 200. FIG.

The holding members 2a-2l can change a movement speed each independently.

The biaxial stretching machine 100 enables the lateral stretching of stretching the thermoplastic resin film 200 in the TD direction in the stretching portion 20, but by changing the moving speed of the gripping members 2a to 2l. The thermoplastic resin film 200 can also be stretched in the MD direction. That is, it is also possible to perform simultaneous biaxial stretching using the biaxial stretching machine 100.

Although the gripping member holding the edge part of the thermoplastic resin film 200 in the TD direction showed only 2a-2l in FIG. 1, since it supports the thermoplastic resin film 200, the biaxial stretching machine 100 is 2a ~. A gripping member (not shown) other than 2l is attached. In addition, below, the holding members 2a-2l may be named generically the "holding member 2".

(a preheating unit)

In the preheating section, the thermoplastic resin film after longitudinal stretching in the first stretching (longitudinal stretching) step is preheated to a temperature at which stretching is possible.

As shown in FIG. 1, the thermoplastic resin film 200 is preheated in the preheating unit 10. In the preheating unit 10, the thermoplastic resin film 200 is heated before stretching, so that the lateral stretching of the thermoplastic resin film 200 can be easily performed.

The film surface temperature (hereinafter also referred to as "preheat temperature") at the end point of the preheating portion is (Tg-10 ° C) to (Tg + 60 ° C) when the glass transition temperature of the thermoplastic resin film 200 is Tg. It is preferable that it is (Tg degreeC)-(Tg + 50 degreeC), and it is more preferable.

In addition, the preheating part end point means the position which terminates preheating of the thermoplastic resin film 200, ie, the position where the thermoplastic resin film 200 moves away from the area | region of the preheating part 10. FIG.

(b. stretching)

In the stretching section, the thermoplastic resin film preheated in the preheating section is stretched (lateral stretching) by applying tension in the width direction (TD direction) perpendicular to the longitudinal direction (MD direction).

Specifically, for example, in the stretched portion 20 shown in FIG. 1, the preheated thermoplastic resin film 200 is provided with a tension at least in the direction of the arrow TD orthogonal to the longitudinal direction of the thermoplastic resin film 200. Thus, the thermoplastic resin film 200 is transversely stretched. For example, as shown in FIG. 1, the width length of a thermoplastic resin film is extended from width L0 to width L1, and it is set as wide width.

Stretching (lateral stretching) in the direction TD orthogonal to the longitudinal direction MD of the thermoplastic resin film 200 is a direction of an angle perpendicular to the longitudinal direction MD of the thermoplastic resin film 200 (90 °). Although it intends to extend | stretch in the drawing, in consideration of a mechanical error, it is not limited only to 90 degrees, It also includes extending | stretching in the direction of the angle (90 degrees +/- 5 degrees) which can be considered perpendicular to MD direction of a film.

In the extending | stretching part 20, the area magnification (the product of the draw ratio of 1st draw | stretching and the draw ratio of 2nd draw) of the thermoplastic resin film 200 is 12.8 times the area of the thermoplastic resin film 200 before extending | stretching. ~ 15.5 times. Details are as described above.

Moreover, as film surface temperature (henceforth "the 2nd extending | stretching temperature") at the time of lateral stretch of the thermoplastic resin film 200, 100 degreeC-150 degreeC are preferable, 110 degreeC-140 degreeC is more preferable, 120 degreeC ˜130 ° C. is more preferred.

If the second stretching temperature is 100 ° C or higher, the risk of breakage due to excessively large yield stress is lowered. Moreover, it is possible to adjust surface roughness Ra to the range mentioned above by adjustment of 2nd extending | stretching temperature (film surface temperature), it is difficult for a film to buckle in TD, and even when it carries out heat conveyance of a thin thermoplastic resin film, it is wavy Wrinkles are less likely to occur.

Moreover, since crystallization of the film itself is suppressed as the 2nd extending | stretching temperature is 150 degrees C or less, it becomes difficult to break.

As a stretching speed | rate at the time of lateral stretch of the thermoplastic resin film 200, it is 5% / sec or more, for example, 8% / sec or more is preferable, 10% / sec or more is more preferable, and 15% / sec or more More preferred.

As an upper limit of the extending | stretching speed at the time of transverse stretching of the thermoplastic resin film 200, it is 50% / sec or less, for example, 45% / sec or less is preferable, 40% / sec or less is more preferable, 30% / sec The above is more preferable, and 20% / sec or less is especially preferable.

Here, the range of the extending | stretching speed at the time of the lateral stretch of the thermoplastic resin film 200 can be set suitably combining each of said upper limit and lower limit arbitrarily. As a range of the extending | stretching speed at the time of the lateral stretch of the thermoplastic resin film 200, for example, there are 8% / sec-45% / sec, there are 15% / sec-40% / sec, and 10% / sec-30% / There are seconds, and there are 10% / second to 20% / second.

In addition, the stretching speed means the value obtained by dividing the length Δd of the thermoplastic resin film drawn for 1 second in the length d ⁰ state before stretching by the length (that is, the length of the point of passing through the preheating section) d ⁰ of the thermoplastic resin film before stretching as a percentage. It is shown.

When the stretching speed is in the above range, the stretching speed is extended at a relatively slow speed, so that the stretching nonuniformity can be suppressed and the roughness of the film surface can be moderately low.

Moreover, when extending | stretching rate is 8% / sec or more, since an extending process does not become excessively long and crystallization of the film resulting from long residence time is suppressed, it becomes difficult to break. Moreover, when extending | stretching rate is 45% / sec or less, it is effective for suppressing break of a film and it can suppress that Ra does not become large too much.

As described above, the gripping members 2a to 2l can each independently change the moving speed. Therefore, the holding member in the MD direction downstream of the extending | stretching part 20, such as the extending | stretching part 20 and the heat-exciting part 30, rather than the moving speed of the holding member 2 in the preheating part 10, for example. By increasing the moving speed of (2), it is also possible to carry out longitudinal stretching which extends the thermoplastic resin film 200 in a conveyance direction (MD direction).

Longitudinal stretching of the thermoplastic resin film 200 in a 2nd extending process may be performed only in the extending | stretching part 20, and may be performed by the heat-fixing part 30, the heat relaxation part 40, or the cooling part 50 mentioned later. do. In addition, longitudinal stretching of the thermoplastic resin film 200 in a 2nd extending process is performed in several places among the extending | stretching part 20, the heat-fixing part 30, the thermal relaxation part 40, and the cooling part 50. FIG. You may also

(c.Open Government)

In the heat-setting unit, the thermoplastic resin film after longitudinal stretching and lateral stretching has already been performed is heated, crystallized and heat-set.

The heat setting means heating in the extending | stretching part 20 with the tension given to the thermoplastic resin film 200, and crystallizing a thermoplastic resin (for example, polyester).

In the heat setting part 30 shown in FIG. 1, with respect to the thermoplastic resin film 200 to which tension was applied, the highest achieved film surface temperature ("heat setting temperature", "in this specification") of the surface of the thermoplastic resin film 200 It is preferable to control the T _{heat setting} ") to the range of 160 degreeC-240 degreeC, and to heat a film.

When the heat setting temperature is 160 ° C or higher, the thermoplastic resin (for example, polyester) is easy to crystallize, and the molecule of the thermoplastic resin (for example, polyester) can be immobilized in an elongated state, and the water resistance of the thermoplastic resin film Degradability is increased. When the heat setting temperature is 240 ° C. or lower, slippage is less likely to occur at the part where the molecules of the thermoplastic resin (for example, polyester) are entangled and the molecules are less likely to be reduced, so that the hydrolysis resistance of the thermoplastic resin film is lowered. Is suppressed. In other words, by heating so that a heat setting temperature may be 160 degreeC-240 degreeC, the crystal | crystallization of the molecule | numerator of a thermoplastic resin (for example, polyester) is orientated, and the hydrolysis resistance of a thermoplastic resin film becomes high.

For the same reasons as the above, the heat setting temperature is preferably in the range of 170 ° C to 230 ° C, and more preferably in the range of 175 ° C to 225 ° C.

In addition, the highest achieved film surface temperature (heat setting temperature) is a value measured by making a thermocouple contact the surface of a thermoplastic resin film.

Moreover, when controlling heat setting temperature to 160 degreeC-240 degreeC, it is preferable to make the deviation of the highest achieved film surface temperature in a film width direction into 0.5 degreeC or more and 10.0 degrees C or less. In the film width direction, when the maximum reaching film surface temperature of the film is 0.5 ° C or more, the degree of crystallization in the width direction is advantageous in terms of wrinkles at the time of conveyance in the subsequent step, and by suppressing the deviation to 10.0 ° C or less. The deviation of is suppressed. As a result, the relaxation difference in the film width direction is reduced, the occurrence of scratches on the film surface in the manufacturing process is prevented, and the hydrolysis resistance is increased.

In the above-mentioned, 0.5 degreeC or more and 7.0 degrees C or less are more preferable, 0.5 degreeC or more and 5.0 degrees C or less are more preferable, and, as for the deviation of the highest achieved film surface temperature, the 0.5 degreeC or more and 4.0 degrees C or less are especially preferable. .

Moreover, heating to the film at the time of heat setting may be performed only in one side of a film, and may be performed in both sides. For example, when cooled on a casting roll after melt extrusion in a film forming step, the molded thermoplastic resin film has a different cooling method from one surface and a surface on the opposite side, so that the film is easy to curl. For this reason, it is preferable to perform the heating in this heat | fever part with respect to the surface which contacted the casting roll in a film forming process. The curl can be eliminated by making the heating surface at the heat-setting part contact with the casting roll, that is, the cooling surface.

In this case, it is preferable that heating is performed so that the surface temperature immediately after the heating on the heating surface at the heat-setting part is higher than the surface temperature of the non-heating surface on the side opposite to the heating surface in the range of 0.5 ° C or more and 5.0 ° C or less. Do. If the temperature of the heating surface at the time of heat setting is higher than the surface on the opposite side, and the temperature difference between the front and back is 0.5-5.0 degreeC, the curl of a film will be eliminated more effectively. From the viewpoint of the effect of removing curl, the temperature difference between the heating surface and the non-heating surface on the opposite side is more preferably in the range of 0.7 to 3.0 ° C, more preferably 0.8 ° C or more and 2.0 ° C or less.

In addition, in at least one of the heat-setting part 30 and the heat relaxation part 40, the method of heating a thermoplastic resin film may be a method of blowing hot air, and the method of selectively radiating-heating by a heater may be sufficient. By selectively performing radiant heating on the thermoplastic resin film, the film surface temperature distribution in the TD direction can be controlled uniformly, and the quality (for example, heat shrinkage) of the produced thermoplastic resin film can be made uniform.

In the case of selectively radiating and heating the film in the thermal relaxation unit 40, the radiant heating in the heat-setting section 30 may be omitted, or the radiant heating in the heat-setting section 30 may be performed in parallel.

As a heater which can perform radiant heating, an infrared heater is mentioned, for example, The ceramic heater (ceramic heater) is especially preferable.

When heating a film in a heat part, it is preferable to make residence time in a heat part more than 5 second and 50 second or less. The residence time is a time when the state in which the film is heated in the heat-setting part is continued. If the residence time is 5 seconds or more, the degree of crystallinity change with respect to the heating time is small, which is advantageous in that the nonuniformity of the crystallization degree in the width direction is less likely to occur, and if it is 50 seconds or less, the line speed of the tenter can be made extremely small. Since there is no need, it is advantageous in terms of productivity.

Especially, since the residence time is the same as the above, 8 second or more and 40 second or less are preferable, and 10 second or more and 30 second or less are more preferable.

(d.heat relaxation unit)

In the heat-relaxing portion, the heat-set thermoplastic resin film is heated, and the tension of the thermoplastic resin film is thermally relaxed to remove residual distortion of the film. By this heat relaxation, the film shrinks at least one of the longitudinal direction and the transverse direction.

Thermal relaxation heats a thermoplastic resin film which was heat-set, and thermally relaxes the tension of a thermoplastic resin film, It is preferable to perform the heating to the thermoplastic resin film in a thermal relaxation part as follows.

In the thermal relaxation part 40 shown in FIG. 1, the highest achieved film surface temperature of the surface of the thermoplastic resin film 200 is the highest reached film surface temperature of the thermoplastic resin film 200 in the _heat-setting part 30 (T _{heat | fever). The} aspect which heats the thermoplastic resin film 200 is preferable so that it may become a temperature 5 degreeC or more lower than the _fixed ).

Hereinafter, the highest achieved film surface temperature of the surface of the thermoplastic resin film 200 at the time of _{heat relaxation} is also called "heat relaxation temperature (T _{heat relaxation} )."

In the thermal relaxation section 40, the thermal relaxation temperature (T _{heat relaxation} ) is heated to a temperature (T _{heat relaxation} ≤ T _{heat setting} -5 ° C) 5 ° C or more lower than the heat setting temperature (T _{heat setting} ) to _reduce tension. By relaxing (stretching tension small), the dimensional stability of a thermoplastic resin film can be improved more.

When T _{heat relaxation} is "T _{heat setting} -5 degreeC" or less, the hydrolysis resistance of a thermoplastic resin film is more excellent. Moreover, it is preferable that T _{heat relaxation} is 100 degreeC or more from the point which dimensional stability becomes favorable.

Furthermore, _{the thermal relaxation} and T is not less than 100 ℃, also preferably a _heat-T more than 15 ℃ low temperature region (100 ℃ ≤T _{thermal relaxation} ≤T _heat--15 ℃), more than 110 ℃, also It is more preferable that it is a temperature range 25 degreeC or more lower than T _{heat setting} (110 degreeC <T _{heat relaxation | =} T _{heat setting} -25 degreeC), and it is 120 degreeC or more and also 30 degreeC or more lower than T _{heat setting} (120 degreeC) ≦ T _{heat relaxation} ≦ T _{heat setting} −30 ° C.).

In addition, T _{heat relaxation} is a value measured by making a thermocouple contact the surface of the thermoplastic resin film 200. FIG.

(e. Cooling unit)

In the cooling unit, the thermoplastic resin film after thermal relaxation in the thermal relaxation unit is cooled. Moreover, tension is given to the film width direction simultaneously with cooling of a thermoplastic resin film, and it expands or contracts in the range of -1.5%-3% with respect to the film width at the time of completion | finish of heat relaxation in a heat relaxation part.

As shown in FIG. 1, in the cooling part 50, the thermoplastic resin film 200 which passed through the heat relaxation part 40 is cooled. The shape of the thermoplastic resin film 200 is fixed by cooling the thermoplastic resin film 200 heated by the heat-fixing portion 30 or the heat-relaxing portion 40. The biaxially stretched thermoplastic resin film of width L2 is shown by FIG.

Here, the same method as the stretching in the stretching unit 20 described above may be used for the expansion of the film width in the cooling unit 50.

Moreover, what is necessary is just to use the method similar to the thermal relaxation of the tension of the film in the thermal relaxation part 40 demonstrated above in order to reduce the film width in the cooling part 50. As shown in FIG.

As the holding member holding the thermoplastic resin film is far from the thermoplastic resin film, the thermoplastic resin film is far from the region of the cooling portion. For example, the edge part of the cooling part 50 when the holding member 2j shown in FIG. 1 separates the thermoplastic resin film 200 at P point and the holding member 2l at Q point, respectively. (End of MD direction) is shown by the straight line which followed P point and Q point.

The temperature (hereinafter also referred to as "cooling temperature") of the surface (film surface) of the thermoplastic resin film at the cooling part outlet of the thermoplastic resin film 200 in the cooling part 50 is the temperature of the thermoplastic resin film 200. When it is set as glass transition temperature Tg, it is preferable that it is lower than Tg + 50 degreeC. Specifically, it is preferable that cooling temperature is 25 degreeC-110 degreeC, More preferably, it is 25 degreeC-95 degreeC, More preferably, it is 25 degreeC-80 degreeC. If the cooling temperature is within the above range, the film can be prevented from being unevenly reduced after loosening the clip gripping.

Here, the cooling section outlet refers to an end portion of the cooling section 50 when the thermoplastic resin film 200 moves away from the cooling section 50, and the holding member 2 (holding the thermoplastic resin film 200) ( In FIG. 1, the holding | gripping tool 2j and 2l say the linear part which connected the position, ie, P point and Q point, when the thermoplastic resin film 200 is separated.

Moreover, in the cooling part 50, it is preferable to make the average cooling rate at the time of cooling the temperature of the surface (film surface) of a thermoplastic resin film from 150 degreeC to 70 degreeC in the range of 2 degree-C / sec-100 degree-C / sec. .

Here, an average cooling rate is calculated | required by measuring the film temperature of the film in a cooling zone with a radiation thermometer. That is, the cooling time (Z ÷ S) second from 150 degreeC to 70 degreeC is calculated | required from the distance Zm of the point where membrane temperature becomes 150 degreeC, and the point where membrane temperature becomes 70 degreeC, and the conveyance speed Sm / sec of a film. . There, the average cooling rate is also obtained by calculating (150-70) ÷ (Z ÷ S).

By making the average cooling rate 2 degrees C / sec or more, the lack of cooling of the thermoplastic resin film in an extending apparatus is suppressed, and the adhesiveness of a thermoplastic resin film becomes low. For this reason, in the process after a thermoplastic resin film moves away from a cooling part exit, failure, such as a thermoplastic resin film sticking to a film conveyance roll, becomes difficult to generate | occur | produce. In addition, by setting the average cooling rate at 100 ° C / sec or less, rapid cooling of the thermoplastic resin film is prevented, residual stress nonuniformity is less likely to occur in the film surface, nonuniformity of thermal contraction rate is suppressed, and striped burrs are less likely to occur. .

4 degrees C / sec-80 degrees C / sec are more preferable, and, as for an average cooling rate, 5 degrees C / sec-50 degrees C / sec are more preferable.

In the preheating, stretching, heat setting, heat relaxation, and cooling in the second stretching step, as the temperature control means for heating or cooling the thermoplastic resin film 200, the thermoplastic resin film 200 is warm or cold. Or spraying the thermoplastic resin film 200 into contact with the surface of the metal plate that can be temperature controlled or passing the vicinity of the metal plate.

(Recovery of film)

The thermoplastic resin film 200 cooled by the cooling process cuts the holding | gripping part hold | gripped with the clip of the both ends of a TD direction, and is wound up in roll shape.

In a 2nd extending process, in order to further improve the hydrolysis resistance and dimensional stability of the thermoplastic resin film manufactured, it is preferable to relax | stretch the stretched thermoplastic resin film by the following method.

In this indication, after performing a 2nd extending process after a 1st extending | stretching (longitudinal stretching) process, it is preferable to perform relaxation of MD direction in the cooling part 50. As shown in FIG. In other words,

In the preheating part 10, both ends of the width direction TD of the thermoplastic resin film 200 are gripped using at least two holding members with respect to the one end part. For example, one end portion of the thermoplastic resin film 200 in the width direction TD is gripped by the gripping members 2a and 2b, and the other is gripped by the gripping members 2c and 2d. Next, the thermoplastic resin film 200 is conveyed from the preheating part 10 to the cooling part 50 by moving the holding members 2a to 2d.

In this conveyance, the holding member 2a (2c) and the holding member 2a (2c) which hold | grip the one end part of the width direction (TD direction) of the thermoplastic resin film 200 in the preheat part 10 are carried out. The holding member 2a (2c) which hold | grips the one end part of the width direction of the thermoplastic resin film 200 in the cooling part 50, and the holding member ((s) rather than the space | interval with other holding | gripping tool 2b (2d) which adjoins. The conveyance speed of the thermoplastic resin film 200 is made slow by narrowing the space | interval with the other holding member 2b (2d) adjacent to 2a (2c). By this method, the cooling unit 50 can relax the MD direction.

Relaxation of the MD direction of the thermoplastic resin film 200 may be performed in at least one of the heat setting part 30, the heat relaxing part 40, and the cooling part 50.

As mentioned above, the MD direction of the thermoplastic resin film 200 can be relaxed by narrowing the space | interval between the holding members 2a-2b, and the space | interval between the holding members 2c-2d on a downstream side rather than an MD direction upstream. Therefore, in the case where the heat release unit 30a or the heat release unit 40 is opened by the heat release in the MD direction, when the holding members 2a to 2d reach the heat release unit 30 or the heat release unit 40, The preheating part 10 slows the moving speed of the holding members 2a-2d, slows the conveyance speed of the thermoplastic resin film 200, and spaces between the holding members 2a-2b and the space between the holding members 2c-2d. What is necessary is just to narrow rather than the space | interval in.

Example

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described further more concretely by an Example. However, embodiment of this invention is not limited to a following example, as long as it does not deviate from the well-known.

<Synthesis of Polyester Raw Material Resin 1>

As shown below, a polyester (Ti catalyst system) was produced by a continuous polymerization apparatus using a direct esterification method in which terephthalic acid and ethylene glycol were directly reacted to distill off water, esterification, and polycondensation under reduced pressure. PET).

(1) esterification reaction

In a first esterification tank, 4.7 tons of high-purity terephthalic acid and 1.8 tons of ethylene glycol were mixed for 90 minutes to form a slurry, and were continuously supplied to the first esterification reactor at a flow rate of 3800 kg / h. In addition, an ethylene glycol solution of a citrate chelate titanium complex (VERTEC AC-420, manufactured by Johnson Massey Corporation) in which citric acid was distributed to Ti metal was continuously supplied, and an average residence time of about 4.3 ° C. was maintained at 250 ° C. under stirring. The reaction was carried out in time. At this time, the citrate chelate titanium complex was continuously added so that the amount of Ti added was 9 ppm in terms of an element. At this time, the acid value of the obtained oligomer was 600 equivalent / ton. In addition, in this specification, "equivalent / t" shows the molar equivalent per ton.

The reactant was transferred to a second esterification reactor and reacted at 250 ° C in the reaction tank for 1.2 hours with an average residence time while stirring to obtain an oligomer having an acid value of 200 equivalents / ton. The second esterification tank is divided into three zones, and the ethylene glycol solution of magnesium acetate is continuously supplied from the second zone so that the amount of Mg added is 75 ppm in terms of the element, and then from the third zone. The ethylene glycol solution of trimethyl phosphate was continuously supplied so that the amount of P added was 65 ppm in terms of the element.

(2) polycondensation reaction

The esterification product obtained above was continuously supplied to the first condensation polymerization reactor, and stirred, and polycondensed at a reaction temperature of 270 ° C. and a pressure of 20 torr (2.67 × 10 ⁻³ MPa) in the reactor for an average residence time of about 1.8 hours. I was.

Furthermore, it transfers to a 2nd polycondensation reaction tank, and in this reaction tank, reaction is carried out under the conditions of the residence time of about 1.2 hours by reaction temperature in the reaction tank at 276 degreeC, and pressure of 5 torr (6.67 * 10 <^-4> MPa) in reaction tank. I was.

Subsequently, the reaction mixture was further transferred to a third condensation polymerization reactor, in which reaction temperature (278 condensation) at a temperature of 278 ° C. and a pressure of 1.5 torr (2.0 × 10 ⁻⁴ MPa) in the reaction vessel was reacted under conditions of a residence time of 1.5 hours (polycondensation). The reaction product (polyethylene terephthalate (PET)) was obtained.

Next, the obtained reactant was discharged in the form of strands in cold water, and immediately cut to produce pellets of polyester <cross section: about 4 mm long, about 2 mm short, and about 3 mm long>.

The obtained polyester was measured as shown below using high-resolution high frequency inductively coupled plasma-mass spectrometry (HR-ICP-MS; AttoM manufactured by SII Nanotechnology, Inc.). As a result, Ti = 9 ppm, Mg = 75 ppm, and P = 60 ppm It was. Although P slightly decreased with respect to the original addition amount, it is presumed to be volatilized in the polymerization process.

The polymer obtained was IV = 0.67 and the amount (AV) of the terminal carboxyl group (AV) = 23 equivalents / ton, melting point = 257 占 폚, and solution haze = 0.3%. Measurement of IV and AV was performed by the method shown below.

Measurement of IV and AV

Intrinsic viscosity (IV) of polyester raw resin melt | dissolves polyester raw resin in the 1,1,2,2- tetrachloroethane / phenol (= 2/3 [mass ratio]) mixed solvent, and in the mixed solvent It calculated | required from the solution viscosity in 25 degreeC.

The amount of terminal COOH (AV) of the polyester raw material resin was completely dissolved in the mixed solution of benzyl alcohol / chloroform (= 2/3; volume ratio) by using the phenol red as an indicator. And a reference solution (0.025N KOH-methanol mixed solution) were titrated and calculated from the appropriate amounts.

The polyester raw resin 1 was synthesize | combined as mentioned above.

(Examples 1-15, and Comparative Examples 1-4)

<Production of Unstretched Polyester Film>

After drying polyester raw material resin 1 to 20 ppm or less of water content, it injected | thrown-in to the hopper of the monoaxial kneading extruder of diameter 50mm. The polyester raw material resin 1 was melt | dissolved at 300 degreeC, and it extruded from the die through the gear pump and the filter (20 micrometers of hole diameter) by the following extrusion conditions. Moreover, the dimension of the slit of the die was adjusted so that the thickness of a polyester sheet might be 0.4 mm. The thickness of the polyester sheet was measured by the automatic thickness meter installed in the exit of the casting roll.

At this time, extrusion of molten resin was performed on the conditions which made pressure fluctuation into 1%, and makes temperature distribution of molten resin into 2%. Specifically, the back pressure in the barrel of the extruder was heated to 1% higher than the average pressure in the barrel of the extruder, and the piping temperature of the extruder was heated to 2% higher than the average temperature in the barrel of the extruder. . In extruding from the die, the molten resin was extruded onto a cooling casting roll, and brought into close contact with the casting roll by using an electrostatic application method. Cooling of the molten resin set the temperature of the casting roll to 25 degreeC, and also sprayed 25 degreeC cold air from the cold air generating apparatus provided facing the casting roll, and added to molten resin. The unstretched polyester film (unstretched polyester film 1) of thickness 0.4mm and film width 0.9m was peeled from the casting roll by the peeling roll arrange | positioned facing the casting roll.

Further, except that the dimensions of the slit of the die and the discharge amount of the molten resin were adjusted, the unstretched polyester film 2 (used in Example 12 below) having a thickness of 2.8 mm and the unstretched poly having a thickness of 1.2 mm in the same manner as described above. The ester film 3 (used in Example 13 below) and the unstretched polyester film 4 (used in Example 14 below) having a thickness of 0.9 mm were peeled off.

In addition, all film widths are 0.9 m.

The obtained unstretched polyester films 1-4 were intrinsic viscosity IV = 0.64dL / g, the quantity (AV) of the terminal carboxy group (25) / tonne, and glass transition temperature (Tg) = 72 degreeC.

Measurement of IV and AV was performed by the same method as the above.

<Production of Biaxially Stretched Polyester Film>

About the obtained unstretched polyester films 1-4, biaxial stretching is performed sequentially through each of the following processes, and the biaxially stretched polyester film of 31 micrometers in thickness and 2.5 m of film width (total length of TD) is produced. did.

First drawing process

Unstretched polyester film 1-4 was passed between two pairs of nip rolls from which a circumferential speed differs, and 1st extending | stretching (longitudinal stretching) was performed to MD direction (transfer direction) on the following conditions.

<Condition>

Preheating temperature: 80 ℃

Stretching temperature: 90 ℃

Stretch ratio: Magnification (fold) shown in Table 1 below

Stretching stress: 12MPa

Second Stretching Process

The longitudinal stretched polyester film (uniaxially stretched polyester film) was subjected to second stretching (lateral stretching) under the following method and conditions using a tenter (biaxial stretching machine) having a structure shown in FIG. 1.

(Preheater)

The preheating temperature was 110 degreeC, and it heated so that extending | stretching was possible.

(Extension department)

The preheated uniaxially stretched polyester film was stretched under the following conditions in the film width direction (TD direction) orthogonal to the MD direction, and stretched (lateral stretching).

<Condition>

Stretching temperature: Temperature (° C) shown in Table 1 below

Stretch ratio: Magnification (fold) shown in Table 1 below

Stretching stress: 18MPa

Drawing speed: Drawing speed (% / second) shown in Table 1 below

In addition, the draw ratio at the time of performing said 1st stretch and 2nd stretch was adjusted, and the area ratio after 1st stretch and 2nd stretch was adjusted to the magnification shown in following Table 1.

An area magnification is a product of the draw ratio at the time of 1st stretch, and the draw ratio at the time of 2nd stretch.

(Open government)

Subsequently, the highest achieved film surface temperature (heat setting temperature) of the polyester film was controlled in the following range to be heated and crystallized.

· Maximum attainment surface temperature (heat setting temperature T _{heat setting} ): 220 [℃]

(Heat relief unit)

The polyester film after heat setting was heated to the following temperature, and the tension of the film was thermally relaxed.

<Condition>

Thermal relaxation temperature (T _{thermal relaxation} ): 190 ° C

Thermal relaxation rate: TD direction (TD thermal relaxation rate ΔL) = 5%

(Cooling unit)

Next, the polyester film after heat relaxation was cooled at the cooling temperature of 65 degreeC. At the same time, tension was applied to the polyester film in the film width direction (TD direction) under the following conditions, and a slight expansion or reduction treatment was performed.

<Condition>

Magnification of expansion or contraction: Value (%) shown in Table 1 below

Expansion or contraction rate: 0.1% / second

In addition, magnification shows the expansion ratio or reduction ratio with respect to the film width at the time of completion | finish of heat relaxation in said heat relaxation part. In addition, the negative value of Table 1 shows "reduction".

Recovery of film

After the end of cooling, both ends of the polyester film were trimmed by 20 cm. Then, after extrusion process (knurling) in width 10mm at both ends, it wound up at 25 kg / m of tension.

As described above, a biaxially stretched polyester (PET) film having a thickness of 31 μm was produced.

<Production of Biaxially Stretched Cyclic Polyolefin Film>

In the production of the above PET film, except that polyester raw resin 1 was replaced with ARTON (registered trademark; specific gravity p: 1.08 g / cm ³ , glass transition temperature (Tg): 138 ° C, manufactured by JSR Corporation), The biaxially stretched cyclic polyolefin film (COP) was produced similarly to preparation of said biaxially stretched polyester (PET) film.

In addition, 1st extending | stretching and 2nd extending | stretching were performed as follows.

That is, 1st extending | stretching (longitudinal stretching) is performed by preheating temperature: 120 degreeC, extending | stretching temperature: 140 degreeC, and draw ratio 3.5 times, and 2nd extending | stretching (lateral stretching) is preheating temperature of preheating part: 120 degreeC, extending | stretching of an extending | stretching part. It carried out on the conditions similar to preparation of said PET film except having performed at temperature: 140 degreeC, the draw ratio 4.2 times, the draw rate: 18% / sec, and the magnification 1.5% of the expansion of a cooling part.

Measurement and Evaluation

The following measurement and evaluation were performed about the biaxially stretched polyester film and biaxially stretched cyclic polyolefin film obtained by making it above. The results of the measurements and evaluations are shown in Table 1 below.

-One. Modulus of elasticity E ³⁰ , E ⁹⁰ , E ¹²⁰ , E ¹⁵⁰ and E ^180-

From the biaxially stretched polyester film or the biaxially stretched cyclic polyolefin film, the sample piece of width 6mm x 115 mm (JIS K 6251, dumbbell type No. 5 type | mold) of the outermost part was punched out. The obtained sample piece was extended | stretched on Tenchiron (Toyo Seiki Co., Ltd. product, strograph VE50) on 50 mm of chuck | zippers, and the conditions of 100 mm / min of tensile velocity, and the elongation of the film with respect to a load was measured. Next, the graph which made a load the horizontal axis and the elongation the vertical axis was created from the measured value, and the elasticity modulus was computed from the tangent of the rise part of a load-extension curve. This operation was performed 5 times, and the average value of three points except the maximum value and the minimum value was made into an elastic modulus.

The elasticity modulus at the time of tension in the film conveyance direction and the case of the tension in the film width direction with respect to each temperature, and the elasticity modulus at the time of tension in the film conveyance direction is set to E ^TD , and the tension in the film width direction. ^Was E ^TD .

<Measurement conditions>

Measuring place: hot air furnace

Measurement temperature: 30 ° C, 90 ° C, 120 ° C, 150 ° C, 180 ° C

(The set temperature of the furnace rises to a desired temperature in 1.5 minutes, and temperature setting and air volume adjustment are performed so that the temperature rise is within 2 ° C even if 1 minute has elapsed from the desired temperature.)

Temperature control: The test piece of the same size for temperature measurement was installed in the vicinity of the test piece, the thermocouple was affixed on the test piece for temperature measurement, and the temperature at the time of a measurement was monitored.

Test start timing: The tension was started after the desired temperature was reached.

-2. Surface Roughness Ra-

Using a contact shape measuring instrument (Mitutoyo FORMTRACER EXTREME CS-5000CNC), the measurement was performed 12 times each at any position in the MD direction and the TD direction of the biaxially stretched polyester film or the biaxially stretched cyclic polyolefin film under the following conditions. The average of 10 points in the MD direction and 10 points in the TD direction except for the minimum value and the maximum value of Ra was obtained, and the average value of 20 points was defined as Ra.

<Condition>

Measuring needle tip diameter: 0.5 μm

Probe load: 0.75 mN

Measuring length: 0.8mm

Cutoff value: 0.08mm

-3. Thickness of the film

Using a tactile film thickness meter (Mitutoyo ID-C112X), the biaxially stretched polyester film or the biaxially stretched cyclic polyolefin film was measured at 50 mm intervals over the entire width of the TD direction. This operation was performed 5 sets at 1m intervals in MD direction, and the average value of the measured value was made into thickness.

-4. Striped Burr-

The biaxially stretched polyester film or the biaxially stretched cyclic polyolefin film is passed through a heat transfer device, and the heat transfer treatment is carried out at a conveyance tension of 1 MPa for 1 minute at a maximum temperature of 90 ° C, 120 ° C, 150 ° C or 180 ° C. Done. Thereafter, the biaxially stretched polyester film or the biaxially stretched cyclic polyolefin film having completed the heat transfer treatment is placed on a plane, and the biaxially stretched polyester film or the cyclic polyolefin film is reflected so that light of a fluorescent lamp installed on the ceiling of the room is reflected. Observation was carried out obliquely, and the curvature state of the reflection image of a fluorescent lamp reflected on the biaxially stretched polyester film or the biaxially stretched cyclic polyolefin film was evaluated according to the following evaluation criteria.

<Evaluation Criteria>

AA: There is no curvature of a reflection phase, and generation | occurrence | production of a striped burr is not recognized.

A: Although a striped burr was seen to be partially blurred, the curvature of the reflective phase was weak and practically not impaired.

B: Although the reflection image appears faintly curved all over, it is not enough to cause a malfunction.

C: The generation of streaked burrs is remarkable, and the curvature of the reflective image is strongly strong across the board, causing practical problems.

TABLE 1

As shown in Table 1, in the Example whose elastic modulus ratio Er ^{30 in} 30 degreeC and the elastic modulus ratio Er in the temperature range which reach 30 degreeC-180 degreeC are suitably adjusted, generation of a stripe-like burr also in the film whose thickness is 200 micrometers or less This was suppressed, and the suppressive effect of the striped burr was remarkable also in the thin film whose thickness is less than 100 micrometers.

On the contrary, in Comparative Examples 1 to 4 in which the elastic modulus ratio or the variation in the elastic modulus ratio (the difference between the maximum value Er _max and the minimum value Er _min ) deviated from the desired range, the occurrence of wrinkles in the TD direction was not suppressed, Development appeared to be marked.

2a ~ 2l gripping member
3 film
4 bounce rolls
10 preheater
20 drawing parts
30 Open Government
40 Thermal Relaxation Unit
50 cooling section
60a, 60b annular rail
100 2-axis stretching machine
200 polyester films
P, Q holding member separates the thermoplastic film
MD film conveyance direction (length direction)
TD film width direction
Width of L0, L1, L2 thermoplastic film
Z ¹ , Z ² expansion
σ _x stress
As for the indication of the Japanese patent application 2017-037662 for which it applied on February 28, 2017, the whole is taken in into this specification by reference.
All documents, patents, patent applications, and technical specifications described in this specification are specifically equivalent to the case where individual documents, patents, patent applications, and technical specifications are incorporated by reference, and to the same extent as if individually recorded. It is incorporated by reference in the specification.

Claims (12)

The ratio Er ³⁰ in 30 ^degreeC of the elasticity modulus ^ETD of the film width direction orthogonal to the film conveyance direction with respect to the elasticity modulus ^EMD of a film conveyance direction is 1.1-1.8, and
The elastic modulus of the elastic modulus E ^TD of the E ^MD, in the non-Er ^30, non Er ^150, and 180 ℃ in non Er ^120, 150 ℃ in non Er ^90, 120 ℃ at 90 ℃ in the 30 ℃ The thermoplastic resin film whose difference of the maximum value Er _max and minimum value Er _min selected from ratio Er ¹⁸⁰ is 0.7 or less. The method according to claim 1,
The thermoplastic resin film whose surface roughness Ra of at least one surface is 0.5 nm-50 nm. The method according to claim 1 or 2,
The thermoplastic resin film whose thickness is 200 micrometers or less. The method according to any one of claims 1 to 3,
The thermoplastic resin film which is a polyester film or a cyclic polyolefin film. As a manufacturing method of the thermoplastic resin film of any one of Claims 1-4,
Melting and extruding the raw material resin and cooling to form a thermoplastic resin sheet;
Performing a first drawing in the longitudinal direction with respect to the thermoplastic resin sheet to obtain a thermoplastic resin film;
The preheating part for preheating the thermoplastic resin film, the preheated thermoplastic resin film are stretched and stretched in the film width direction orthogonal to the longitudinal direction of the thermoplastic resin film, and the thermoplastic resin film subjected to the tension is opened by heating. And a step of carrying out the second stretching by sequentially conveying the thermoplastic resin film to a heat-setting portion to be determined, a heat-relaxing portion for thermally relaxing the tension, and a cooling portion for cooling the heat-relaxed thermoplastic resin film.
The area magnification which is the product of the draw ratio in the said 1st draw | stretching, and the draw ratio in the said 2nd stretch is 12.8 times-15.5 times,
In the step of performing the second stretching, in the cooling portion, the thermally relaxed thermoplastic resin film is further subjected to tension in the film width direction, to the film width at the end of the thermal relaxation at the thermal relaxation portion. A method for producing a thermoplastic resin film, wherein the thermoplastic resin film is expanded or reduced in the range of -1.5% to 3% relative to the above-mentioned. The method according to claim 5,
The process of performing said 2nd extending | stretching is a manufacturing method of the thermoplastic resin film which extends | stretches a said thermoplastic resin film with a extending | stretching speed being 8% / sec-45% / sec in the said extending | stretching part. The method according to claim 5 or 6,
The process of performing said 2nd extending | stretching is a manufacturing method of the thermoplastic resin film which extends | stretches the said thermoplastic resin film in the said extending | stretching part as a drawing speed | rate to 15% / sec-40% / sec. The method according to any one of claims 5 to 7,
The process of performing a said 2nd extending | stretching is a manufacturing method of the thermoplastic resin film which extends | stretches a said thermoplastic resin film by making extending | stretching temperature into 100 to 150 degreeC in the said extending part. The method according to any one of claims 5 to 8,
The said 2nd extending process is a manufacturing method of the thermoplastic resin film which extends | stretches a said thermoplastic resin film in extending | stretching temperature as 110 degreeC-140 degreeC in the said extending | stretching part. The method according to any one of claims 5 to 9,
The manufacturing method of the thermoplastic resin film whose area magnification which is a product of the draw ratio in the said 1st extending | stretching and the draw ratio in the said 2nd extending | stretching is 13.5 times-15.2 times. The method according to any one of claims 5 to 10,
The step of performing the second stretching includes, in the cooling unit, a thermoplastic resin film that expands the thermoplastic resin film in a range of 0.0% to 2.0% with respect to the film width at the end of the thermal relaxation in the thermal relaxation unit. Method of preparation. The method according to any one of claims 5 to 11,
The said 1st extending process is the manufacturing method of the thermoplastic resin film which performs the 1st extending | stretching whose draw ratio is 2 to 5 times with respect to the said thermoplastic resin sheet.

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