JP7174367B2 - pre-cut film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin film manufacturing method and a pre-cut film.

Conventionally, in the film manufacturing process, tension is applied to the film in the width direction by holding both ends of the film in the width direction with many pins or clips when the film is transported, dried, or heat treated. A tenter-type conveying device that conveys a sheet in a folded state is known (see, for example, Patent Literature 1).

There are several conveying methods in the tenter-type conveying device. Among these transport methods, the pin tenter type transport device grips the film by piercing both ends of the film with a large number of pins along the direction of flow. It has a number of pins arranged on the seat. This pin tenter-type conveying device has a problem that when the shrinkage force (tensile force) of the film increases, the holes formed in the film by the piercing of the pin tear into long holes in the width direction of the film. If the holes formed in the film are torn, the film cannot be properly stretched, resulting in deterioration of quality such as wrinkling of the film. As a result, hole breakage causes production loss and lowers production efficiency. Also, even when using a clip tenter type conveying device in which both ends are gripped with clips, there is the same problem as in the case of using a pin tenter type conveying device that the film is torn at the portions gripped by the clips.

Conventionally, in order to solve this problem, it has been proposed to overlay a film with high tear strength as a reinforcing film on the grip portion (end portion) of a film with low tear strength (see Patent Document 2). In addition, when conveying a sheet or the like, it has been proposed to make the inner density of pins in the width direction higher than the density of the outer pins at both ends of the sheet (see Patent Document 3).

Japanese Patent Publication No. 39-29211 JP-A-11-254521 JP-A-9-77315

However, in the method of Patent Document 2, since a film with high tear strength is superimposed on a film with low tear strength, there is a problem that raw materials are wasted. That is, the gripping portion is a portion that will be slit and discarded after transportation. However, if the gripping portion has a two-layer structure, there is a problem that the portion to be discarded increases.
Moreover, the method of Patent Document 3 cannot cope with a film having a lower tearing strength, and there is a problem that the hole formed in the film is torn by piercing with a pin.

The present invention has been made in view of the above-described problems, and its object is to more effectively suppress tearing of the film when both ends of the film are gripped by a tenter-type conveying device. and a pre-cut film.

The present inventors have conducted intensive research on a method for producing a resin film and a pre-cut film. As a result, by adopting the following configuration, it is possible to more effectively suppress tearing of the film when both ends of the film are gripped by a tenter type conveying device, and completed the present invention. reached.

That is, the method for producing a resin film according to the present invention includes:
A step of applying the first resin composition solution to the central portion of the support;
step B of applying a second resin composition solution to both ends adjacent to the central portion;
step C of drying the first resin composition solution and the second resin composition solution to obtain a pre-cut film;
step D of peeling the film before cutting from the support;
After the step D, a step E of gripping both ends of the film before cutting with a tenter-type conveying device;
a step F of conveying the film before cutting while gripping both ends of the film before cutting;
After the step F, the step G of obtaining a resin film by removing the portion formed from the second resin composition solution from the pre-cut film
has
After the step C and before the step F, the film before cutting had the tear strength of the portion formed from the 21st resin composition solution formed from the 12th resin composition solution. characterized by greater than the tear strength of the part.

According to the above configuration, the first resin composition solution is applied to the central portion of the support (step A), the second resin composition solution is applied to both ends (step B), and the first resin The composition solution and the second resin composition solution are dried to obtain a film before cutting (step C). Both ends of the film thus obtained before cutting are portions formed only from the second resin composition solution. Here, the tear strength of the portion formed only from the second resin composition solution is greater than the tear strength of the portion formed from the first resin composition solution. Therefore, even if both ends of the uncut film are gripped by a tenter-type transport device and transported (step F), the gripped portions (both ends) are unlikely to be torn.
Further, according to the above configuration, after the step F, the portion formed from the second resin composition solution is removed from the pre-cut film to obtain a resin film (step G). According to such a method, even a resin film having a low tear strength can be transported using a conventionally known tenter-type transport device. In addition, since both ends of the film before cutting are formed only from the second resin composition solution, it is possible to minimize the waste of raw materials related to the portions removed in step G.

In the above configuration, the step E is preferably a step of gripping both ends of the pre-cut film with pins of a pin tenter type conveying device.

In the pre-cut film, the tear strength of the portion formed from the first resin composition solution is greater than the tear strength of the portion formed from the second resin composition solution, so that the pin tenter type conveying device Tear by the pin is more preferably suppressed.

In the above configuration, the resin film is preferably a polyimide resin film.

In recent years, there is a high demand for highly transparent polyimide resin films, and such polyimide resin films tend to have low tear strength. Therefore, according to the above configuration, it is possible to suitably obtain a polyimide resin film having particularly low tear strength.

In addition, the film before cutting according to the present invention is
a central portion composed of a first resin composition;
Having both ends formed continuously from the central part at both ends of the central part,
The both ends are made of a second resin composition different from the first resin composition,
The tear strength of the both end portions is higher than the tear strength of the central portion.

According to the above configuration, since the tear strength at both ends is greater than the tear strength at the central portion, even if the film before cutting is transported while being gripped at both ends by a tenter-type transport device, the gripped portions (both ends) ) is less prone to tearing.
In addition, since the both ends of the film before cutting are composed only of the second resin composition, when the both ends are removed to obtain the resin film, waste of the raw material related to the removed parts can be minimized. becomes possible.

The said structure WHEREIN: It is preferable that a said 1st resin composition is a polyimide-type resin.

When the first resin composition is a polyimide resin, a polyimide resin film having a low tear strength can be preferably obtained by removing both ends after transporting the film by a tenter-type transport device.

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to provide a method for producing a resin film and a pre-cut film that can more effectively suppress tearing of the film when both ends of the film are gripped by a tenter-type conveying device. can.

FIG. 4 is a side cross-sectional view for explaining a method of applying a resin composition solution according to the first embodiment; FIG. 2 is a plan view of FIG. 1; 3 is a partially enlarged plan view of the vicinity of a side plate 18b shown in FIG. 2; FIG. FIG. 4 is a cross-sectional view showing a case where each coating film is connected only at the side surfaces; FIG. 6 is a cross-sectional view showing a case where coating films 64a and 64c slightly overlap on a coating film 64b; FIG. 11 is a cross-sectional view showing a case where a coating film 64b slightly overlaps a coating film 64a and a coating film 64c; FIG. 10 is a side cross-sectional view for explaining a method of applying a resin composition solution according to the second embodiment; FIG. 8 is a plan view of FIG. 7; FIG. 11 is a side cross-sectional view for explaining a method of applying a resin composition solution according to the third embodiment; FIG. 10 is a plan view of FIG. 9; FIG. 11 is a cross-sectional view showing a case where the edge of the coating film 64a slightly overlaps the coating film 64b and the edge of the coating film 64b slightly overlaps the coating film 64c. FIG. 11 is a side cross-sectional view for explaining a method of applying a resin composition solution according to a fourth embodiment; FIG. 13 is a plan view of FIG. 12;

Embodiments of the present invention will be described below.

[Method for producing resin film]
The method for producing a resin film according to this embodiment includes:
A step of applying the first resin composition solution to the central portion of the support;
step B of applying a second resin composition solution to both ends adjacent to the central portion;
step C of drying the first resin composition solution and the second resin composition solution to obtain a pre-cut film;
step D of peeling the film before cutting from the support;
After the step D, a step E of gripping both ends of the film before cutting with a tenter type conveying device;
a step F of conveying the film before cutting while gripping both ends of the film before cutting;
After the step F, the step G of obtaining a resin film by removing the portion formed from the second resin composition solution from the pre-cut film
has
After the step C and before the step F, the tear strength of the portion formed from the second resin composition solution of the uncut film was formed from the first resin composition solution. Greater than the tear strength of the part.

<Step A, Step B>
In the method for producing a resin film according to the present embodiment, first, the first resin composition solution is applied to the central portion of the support (step A). Also, a second resin composition solution is applied to both ends adjacent to the central portion (step B). The process A and the process B may be performed at the same time, the process B may be performed after the process A is performed, or the process A may be performed after the process B is performed.

The support is not particularly limited, but is preferably resistant to the solvents of the first resin composition solution and the second resin composition solution, such as PET (polyethylene terephthalate). Resin films, metal drums, endless steel belts, and the like can be used.

The coating method of the step A and the step B is not particularly limited, and examples thereof include a comma coating method, a T-die coating method, a spin coating method, a spray coating method, a bar coating method, a knife coating method, a dipping method, and the like. be done. Two of these methods may be combined. A comma coating method, a T-die coating method, or a combination thereof is preferable from the viewpoint of productivity.

Specific examples of process A and process B are described below.

[First embodiment]
FIG. 1 is a side cross-sectional view for explaining the coating method of the resin composition solution according to the first embodiment, and FIG. 2 is a plan view thereof.
As shown in FIGS. 1 and 2, the coating device 10 has a backup roll 12, a comma roll 14, and three coating liquid reservoirs 16 (16a, 16b, 16c).
The coating liquid reservoir 16 (16a, 16b, 16c) has four side plates 18 (18a, 18b, 18c, 18d) for partitioning the coating liquid reservoir 16 and a back plate 20. As shown in FIG. The coating liquid reservoir 16 ( 16 a , 16 b , 16 c ) can store the coating liquid 62 in a region surrounded by the back plate 20 and the side plate 18 .

Of the three coating liquid reservoirs 16 (16a, 16b, 16c), the second resin composition solutions 62a and 62c are stored in the coating liquid reservoirs 16a and 16c located on both end sides, and the second resin composition solutions 62a and 62c are stored in the coating liquid reservoirs 16a and 16c. A first resin composition solution 62b is stored in the coating liquid storage portion 16b.

The backup roll 12 continuously conveys the support 60 by rotating. The support 60 conveyed by the backup roll 12 passes through the gap 22 formed between the backup roll 12 and the comma roll 14 . When the support 60 passes through the gap 22, the coating liquid 62 (second resin composition solutions 62a and 62c, first resin composition solution 62b) is supplied from the coating liquid reservoir 16 onto the support 60, Coating films 64 (64a, 64b, 64c) are formed. Specifically, a coating film 64 having a thickness equivalent to the thickness of the support 60 subtracted from the gap 22 is formed.

The thickness of the coating film 64 can be controlled by the gap 22 between the backup roll 12 and the comma roll 14 or the like.

FIG. 3 is a partially enlarged plan view of the vicinity of the side plate 18b shown in FIG.
Each coating liquid 62 (second resin composition solutions 62a, 62c, first resin composition solution 62b) spreads in the width direction after being applied onto the support 60. As shown in FIG. Specifically, as shown in FIG. 3, the second resin composition solution 62a applied near the side plate 18b spreads inward in the width direction (to the right in FIGS. 2 and 3). On the other hand, the first resin composition solution 62b applied near the side plate 18b spreads outward in the width direction (to the left in FIGS. 2 and 3). Then, the second resin composition solution 62a (coating film 64a) and the first resin composition solution 62b (coating film 64b) are formed at a portion where the side plate 18b in the flow direction (the upper side in FIGS. 2 and 3) is removed. is connected.
Similarly, the first resin composition solution 62b applied near the side plate 18c spreads outward in the width direction (right side in FIG. 2). On the other hand, the second resin composition solution 62c applied near the side plate 18c spreads inward in the width direction (left side in FIG. 2). Then, the first resin composition solution 62b (coating film 64b) and the second resin composition solution 62c (coating film 64c) are connected where the side plate 18c in the flow direction is removed.
As described above, the coating film 64a and the coating film 64b are connected, and the coating film 64b and the coating film 64c are connected. Examples of the connection include a case where the resin composition solutions forming the coating films 64 are mutually dissolved, and a case where the coating films 64 are connected by an adhesive force at the interface.

The manner in which the coating films 64 are connected is not particularly limited, but when the coating films are connected only at the side surfaces (see FIG. 4), when one of the coating films slightly overlaps the other coating film (see FIG. 4). 5 and 6).

FIG. 4 is a cross-sectional view showing a case where the coating films are connected only at the side surfaces.
In the example shown in FIG. 4, the coating film 64a and the coating film 64b are connected only at the side surfaces. Also, the coating film 64b and the coating film 64c are connected only at the side surfaces. Immediately after the application, they are connected only at the side surfaces, but before the subsequent step C, the second resin composition solution 62a (coating film 64a) and the first resin composition solution 62b (coating film 64b), or the second resin composition solution 62b (coating film 64b) and A composition gradient region is formed by mixing the first resin composition solution 62b (coating film 64b) and the second resin composition solution 62c (coating film 64c). The width of the composition gradient region is preferably in the range of 10 to 2500 times the thickness of the coating film 64b in the portion not in the composition gradient region. More preferably 100 to 1,000 times, still more preferably 250 to 500 times. For example, when the thickness of the coating film 64b is 20 μm, the width of the composition gradient region is preferably 0.2 mm (10 times the thickness of the coating film 64b) to 5 cm (2500 times the thickness of the coating film 64b). . Within this range, breakage from the compositionally graded region is less likely to occur during manufacturing.

FIG. 5 is a cross-sectional view showing a case where the coating films 64a and 64c slightly overlap the coating film 64b.
In the example shown in FIG. 5, the edge of the coating film 64a slightly overlaps the coating film 64b. Also, the edge of the coating film 64c slightly overlaps the coating film 64b. The overlapping portion is the second resin composition solution 62a (coating film 64a) and the first resin composition solution 62b (coating film 64b), or the first resin composition solution 62b (coating film 64b) and the second resin. A composition gradient region is formed by mixing the composition solution 62c (coating film 64c). The width of the composition gradient region is preferably in the range of 10 to 2500 times the thickness of the coating film 64b in the portion not in the composition gradient region. More preferably 100 to 1,000 times, still more preferably 250 to 500 times. For example, when the thickness of the coating film 64b is 20 μm, the width of the composition gradient region is preferably 0.2 mm (10 times the thickness of the coating film 64b) to 5 cm (2500 times the thickness of the coating film 64b). . Within this range, breakage from the compositionally graded region is less likely to occur during manufacturing.

FIG. 6 is a cross-sectional view showing a case where the coating film 64b slightly overlaps the coating films 64a and 64c.
In the example shown in FIG. 6, the edge of the coating film 64b (the left edge in FIG. 6) slightly overlaps the coating film 64a. In addition, the edge of the coating film 64b (the right edge in FIG. 6) slightly overlaps the coating film 64c. As an example of the width of the overlapping portion, as in the case of FIG. 5, it is preferable that the width is in the range of 10 to 2500 times that of the coating film 64b in the portion that is not in the compositionally graded region. More preferably 100 to 1,000 times, still more preferably 250 to 500 times. Within this range, breakage from the compositionally graded region is less likely to occur during manufacturing.

The connection mode can be determined by the gap 22, for example. If the gap 22 through which the second resin composition solutions 62a and 62c pass is the same as the gap 22 through which the first resin composition solution 62b passes, the connection mode shown in FIG. 4 is likely to be achieved. If the gap 22 through which the second resin composition solutions 62a and 62c pass is made slightly wider than the gap 22 through which the first resin composition solution 62b passes, the connection mode shown in FIG. 5 is likely to be obtained. If the gap 22 through which the first resin composition solution 62b passes is slightly wider than the gap 22 through which the second resin composition solutions 62a and 62c pass, the connection mode shown in FIG. 6 is likely to be obtained. The connection mode can be controlled not only by the gap 22 but also by the viscosity of the first resin composition solution 62b and the second resin composition solutions 62a and 62c and the width of the side plate 18.

In 1st Embodiment, the process A and the process B are performed simultaneously by the coating device 10 demonstrated above.

The processes A and B according to the first embodiment have been described above.

[Second embodiment]
FIG. 7 is a side sectional view for explaining the coating method of the resin composition solution according to the second embodiment, and FIG. 8 is its plan view. In addition, the same code|symbol is attached|subjected about the structure which is common in the coating device 30 of 2nd Embodiment with the coating device 10 of 1st Embodiment, and suppose that description is abbreviate|omitted or simplified.

As shown in FIGS. 7 and 8, the coating device 30 has a backup roll 12, a comma roll 14, and two coating liquid reservoirs 16 (16a, 16c) on both sides in the width direction. The coating liquid reservoir 16 ( 16 a, 16 c ) can store the coating liquid 62 in a region surrounded by the back plate 20 and the side plate 18 .

Second resin composition solutions 62a and 62c are stored in the two coating liquid reservoirs 16 (16a and 16c). Note that, unlike the first embodiment, the first resin composition solution is not stored in the coating liquid reservoir 16 in the coating device 30 according to the second embodiment.

The backup roll 12 continuously conveys the support 60 by rotating. The support 60 conveyed by the backup roll 12 passes through the gap 22 formed between the backup roll 12 and the comma roll 14 . When the support 60 passes through the gap 22, the second resin composition solutions 62a and 62c are supplied from the coating liquid reservoir 16 onto the support 60 to form coating films 64a and 64c.

The coating device 30 further includes a T-die coater 32 . The T-die coater 32 is installed after the backup grow roll 12 and the comma roll 14 . The T-die coater 32 is installed such that the ejection port is positioned above the central portion of the support 60 .

When the support 60 on which the coating films 64a and 64c have been formed is transported, the T-die coater 32 applies the first resin composition solution 62b to the central portion of the support 60 .

In the second embodiment, the coating device 30 described above performs the process B first, and then performs the process A. As shown in FIG. In the case of the second embodiment, the connection mode of each coating film 64 is likely to be the connection mode shown in FIG. 6, but is not limited to this. As a modification of the second embodiment, the first resin composition solution is first applied to the central portion of the support using a comma coater, and then the second resin composition solution is applied to both ends using a T-die coater. It may be applied.

The processes A and B according to the second embodiment have been described above.

[Third embodiment]
FIG. 9 is a side cross-sectional view for explaining the coating method of the resin composition solution according to the third embodiment, and FIG. 10 is its plan view. In addition, in the coating device 40 of the third embodiment, the same reference numerals are given to the configurations common to the coating device 30 of the second embodiment, and the description thereof is omitted or simplified.

The coating device 40 includes a T-die coater 42a, a T-die coater 42b, and a T-die coater 42c. The T-die coater 42a and the T-die coater 42c are installed before the T-die coater 42b.
The T-die coater 42a and the T-die coater 42c are installed such that the ejection port is located above the end of the support 60, respectively. In FIG. 10 , the T-die coater 42 a is installed so that the discharge port is positioned above the left end of the support 60 , and the T-die coater 42 c is installed so that the discharge port is positioned above the right end of the support 60 . is installed in
The T-die coater 42b is installed so that the ejection port is positioned above the central portion of the support 60. As shown in FIG.

When the support 60 on which the coating films 64a and 64c have been formed is transported, the T-die coater 42b applies the first resin composition solution 62b to the central portion of the support 60. As shown in FIG.

In the case of the third embodiment, the bonding mode of each coating film 64 is likely to be the bonding mode shown in FIG. 5, but is not limited to this. Further, as a modification of the third embodiment, the second resin composition may be applied to both ends with a T-die coater, and then the first resin composition may be applied to the central portion with a T-die coater. . In this case, the bonding mode of each coating film 64 is likely to be the bonding mode shown in FIG. 6, but is not limited to this.
Furthermore, as another modification, the second resin composition is applied to the end of one side with a T-die coater, and then the first resin composition is applied to the center with a T-die coater, followed by the other side. It is also possible to apply the second resin composition to the ends on one side with a T-die coater. In this case, the bonding mode of each coating film 64 is likely to be the bonding mode shown in FIG. 11, but is not limited to this.
In the example shown in FIG. 11, the edge of the coating film 64a slightly overlaps the coating film 64b. Also, the edge of the coating film 64b (the right edge in FIG. 11) slightly overlaps the coating film 64c.
As shown in the third embodiment and its modification, in steps A and B, a plurality of T-die coaters are arranged in tandem to separate the first resin composition and the second resin composition. It may be in the form of sequential application.

[Fourth embodiment]
FIG. 12 is a side sectional view for explaining the coating method of the resin composition solution according to the fourth embodiment, and FIG. 13 is its plan view. In addition, in the coating device 50 of the fourth embodiment, the same reference numerals are given to the configurations common to the coating device 40 of the third embodiment, and the description thereof will be omitted or simplified.

The coating device 50 includes a T-die coater 52 having three ejection openings divided in the width direction. The T-die coater 52 applies the first resin composition to the central portion of the support 60 and simultaneously applies the second resin composition to both ends.

As shown in FIGS. 12 and 13, the process A and the process B in the fourth embodiment are forms in which the first resin composition and the second resin composition are applied simultaneously. In the case of the fourth embodiment, the bonding mode of each coating film 64 is likely to be the bonding mode shown in FIG. 4, but is not limited to this.

<Process C>
After the step A and the step B, the first resin composition solution and the second resin composition solution are dried to obtain a film before cutting (step C). The drying conditions can be appropriately set within a range in which the solvent can be sufficiently volatilized. For example, the drying temperature is in the range of 60° C. to 140° C., and the drying time is in the range of 1 minute to 60 minutes. can be done. The drying conditions are particularly suitable when dimethylacetamide is used as a solvent because its boiling point is 165°C.
After step C and before step D, a step of winding the uncut film together with the support into a roll (step C-1) may be performed. In this case, before step D, the film before cutting may be unwound again.

<Process D>
After the step C, the film before cutting is peeled off from the support (step D). The method of peeling the film before cutting from the support is not particularly limited, but a method of rolling it up from the edge with tweezers or the like, making a cut in the film before cutting, and attaching an adhesive tape to one side of the cut portion. A method of winding from the tape portion, a method of vacuum-sucking one side of the notched portion of the film before cutting and then winding from that portion, and the like can be employed. As a method of rolling, it is desirable to roll while winding on a roll.
Examples of the method of cutting the film before cutting include a method of cutting the film before cutting with a cutting tool such as a knife, a method of cutting the film before cutting with a laser, and a method of cutting the film before cutting with a water jet. However, it is not particularly limited. For example, in adopting the above-described method, it is also possible to appropriately adopt techniques such as superimposing ultrasonic waves on the cutting tool or adding reciprocating motion or vertical motion to improve cutting performance.
After step D and before step E, a step of winding the pre-cut film into a roll (step D-1) may be performed. In this case, before step E, the film before cutting may be unwound again. When winding the film before cutting, it is preferable to wind the film with interleaving paper (anti-blocking film) interposed therebetween.
By performing the steps C-1 and/or D-1, it is possible to provide a certain period of time after the drying step (step C) until the cutting step (step G) is performed.
After the drying step (step C), the cut film is taken up once and held in that state for a certain period of time, so that the solvent distribution in the thickness direction of the film can be made uniform. This point will be described below.
As shown in FIGS. 5 and 6, when the two coating films slightly overlap, the solvent distribution in the film immediately after drying on the support is such that the amount of solvent remaining in the coating film on the support side is less than that on the surface side. is greater than the amount of solvent remaining in the coating film. If a heating step (for example, step F to be described later) is performed in this state, a difference occurs in the amount of solvent volatilization, and this portion (overlapping portion) may easily tear.
Therefore, by performing the step C-1 and / or the above D-1 to equalize the solvent distribution in the thickness direction of the overlapping portion, the remaining solvent amount of the two types of coating films becomes relatively equal, and this It can be made difficult to tear at the overlapped portion.
After the step C-1 and/or after the step D-1, the period of holding in the rolled state is preferably 30 minutes or longer, more preferably 3 hours or longer. When the film is held in a rolled state for the above period, the solvent can be preferably diffused in the thickness direction.
Further, when the step C-1 and/or the step D-1 is carried out, the pre-cut film is wound once in the middle of the step, so that the production apparatus can be made compact. In other words, when all processes are connected continuously, the production line becomes considerably long, which may limit the location of the factory. On the other hand, if the winding process is carried out during the manufacturing process, the manufacturing line can be divided into two, and the two divided lines can be arranged in parallel, so that a relatively compact manufacturing apparatus can be obtained.
Furthermore, by winding once during manufacturing, it is possible to check the quality during the process.

<Process E>
After the step D, both ends of the film before cutting are gripped by a tenter-type conveying device (step E). Specifically, when a pin tenter type conveying apparatus is used as the tenter type conveying apparatus, both ends of the film before cutting are gripped by piercing a plurality of pins of the pin tenter type conveying apparatus. When a clip tenter type conveying apparatus is used as the tenter type conveying apparatus, both ends of the film before cutting are gripped by being sandwiched between a plurality of clips of the clip tenter type conveying apparatus. As the tenter-type conveying device, conventionally known ones (for example, tenter-type conveying devices disclosed in Japanese Patent No. 4843996 and Japanese Patent No. 4821960) can be used.

<Process F>
After the step E, the film before cutting is conveyed while holding both ends of the film before cutting (step F). You may heat in the case of conveyance. The heating temperature is not particularly limited, but when the first resin composition solution and the second resin composition solution are polyimide resin composition solutions, for example, 150 ° C. to 500 ° C., 1 minute to 60 minutes can be within the range.
In steps E and F, the film before cutting may or may not be stretched in the longitudinal direction and/or the width direction.

In the step F, the pre-cut film generally shrinks in the width direction during transportation. Therefore, tensile tension is applied to the portion gripped by the tenter-type conveying device. Here, although details will be described later, the tear strength of both ends (portions formed from the second resin composition solution) of the film before cutting is lower than that of the central portion (portions formed from the second resin composition solution) part) tear strength. Therefore, tearing of the pre-cut film at the gripped portions (both ends) is suppressed. In particular, when a pin tenter-type conveying device is used as the tenter-type conveying device, tearing due to the pins of the pin tenter-type conveying device is more preferably suppressed.

<Process G>
After step F, the portion formed from the second resin composition solution is removed from the pre-cut film to obtain a resin film (step G). In step G, at least the portion formed from the second resin composition solution may be removed, and together with the portion formed from the second resin composition solution, the portion formed from the first resin composition solution may be removed. Some parts may also be removed. The resin film thus obtained is only the portion formed from the first resin composition solution. That is, a resin film consisting only of a portion with relatively low tear strength is obtained.

The thickness of the resin film is not particularly limited, but is preferably 5 μm to 125 μm, more preferably 7.5 μm to 75 μm, even more preferably 12.5 μm to 50 μm.

The method for removing the portion formed from the second resin composition solution from the film before cutting is not particularly limited, and a conventionally known slitter or the like can be used.

As described above, according to the method for manufacturing a resin film according to the present embodiment, even a resin film having a low tear strength can be transported using a conventionally known tenter-type transport device. In addition, since both ends of the film before cutting are formed only from the second resin composition solution, it is possible to minimize the waste of raw materials related to the portions removed in step G.

The first resin composition solution and the second resin composition solution will be described below.

The first resin composition solution and the second resin composition solution are added from the second resin composition solution in the pre-cutting film after the step C and before the step F. There is no particular limitation as long as the tear strength of the formed portion is greater than the tear strength of the portion formed from the first resin composition solution.

Examples of the first resin composition solution include a polyimide resin composition solution, a polyamide resin composition solution, a polyamideimide resin composition solution, and the like. Among them, a polyimide resin composition solution is preferable. Among polyimide resin films, those generally called transparent polyimide often have weak tear strength, but according to the method for producing a resin film according to the present embodiment, a transparent polyimide resin film with weak tear strength Even if it is, it can be manufactured suitably.

The first polyimide resin composition solution may be a polyamic acid (polyimide precursor) solution or a polyimide solution. When a polyamic acid solution is used, heat treatment is performed in step F to cause a dehydration ring-closing reaction to form a polyimide film. When a polyimide solution is used, the solvent is volatilized in step C to form a polyimide film.

The polyamic acid solution is obtained by reacting diamines and tetracarboxylic acids in a solvent.

Examples of the tetracarboxylic acids include aromatic tetracarboxylic acids (including their acid anhydrides), aliphatic tetracarboxylic acids (including their acid anhydrides), alicyclic tetracarboxylic acids (including their acid anhydrides), which are commonly used in polyimide synthesis. anhydrides) can be used. Among them, aromatic tetracarboxylic anhydrides and alicyclic tetracarboxylic anhydrides are preferable, aromatic tetracarboxylic anhydrides are more preferable from the viewpoint of heat resistance, and alicyclic anhydrides are preferable from the viewpoint of light transmittance. Formula tetracarboxylic acids are more preferred. When these are acid anhydrides, one or two anhydride structures may be present in the molecule, but preferably those having two anhydride structures (dianhydrides) are good. Tetracarboxylic acids may be used alone, or two or more of them may be used in combination.

Among the polyamic acid solutions, a solution capable of obtaining a highly colorless and transparent polyimide is preferable.

Aromatic tetracarboxylic acids for obtaining highly colorless and transparent polyimide include 4,4′-(2,2-hexafluoroisopropylidene)diphthalic acid, 4,4′-oxydiphthalic acid, and 3,4′-oxydiphthalic acid. acid, bis(1,3-dioxo-1,3-dihydro-2-benzofuran-5-carboxylic acid) 1,4-phenylene, bis(1,3-dioxo-1,3-dihydro-2-benzofuran-5 -yl)benzene-1,4-dicarboxylate, 4,4′-[4,4′-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(benzene-1 ,4-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4′-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(toluene-2,5- diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4′-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(1,4-xylene-2,5 -diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4′-[4,4′-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(4-isopropyl -toluene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl ) bis(naphthalene-1,4-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4′-[4,4′-(3H-2,1-benzoxathiol-1,1-dioxide-3 ,3-diyl)bis(benzene-1,4-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'-benzophenonetetracarboxylic acid, 4,4'-[(3H-2,1-benzoxa Thiol-1,1-dioxide-3,3-diyl)bis(toluene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4′-[(3H-2,1-benzoxathiol -1,1-dioxido-3,3-diyl)bis(1,4-xylene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4′-[4,4′-(3H -2,1-Benzoxathiol-1,1-dioxide-3,3-diyl)bis(4-isopropyl-toluene-2,5-diyloxy)]dibenzene-1,2-dicarboxylic acid, 4,4'- [4,4′-(3H-2,1-benzoxathiol -1,1-dioxido-3,3-diyl)bis(naphthalene-1,4-diyloxy)]dibenzene-1,2-dicarboxylic acid, 3,3′,4,4′-benzophenonetetracarboxylic acid, 3, 3′,4,4′-diphenylsulfonetetracarboxylic acid, 3,3′,4,4′-biphenyltetracarboxylic acid, 2,3,3′,4′-biphenyltetracarboxylic acid, 2,2′,3 , 3′-biphenyltetracarboxylic acid, pyromellitic acid, 4,4′-[spiro(xanthene-9,9′-fluorene)-2,6-diylbis(oxycarbonyl)]diphthalic acid, 4,4′-[ Tetracarboxylic acids such as spiro(xanthene-9,9′-fluorene)-3,6-diylbis(oxycarbonyl)]diphthalic acid and acid anhydrides thereof can be mentioned. Among these, dianhydrides having two acid anhydride structures are preferred, particularly 4,4′-(2,2-hexafluoroisopropylidene)diphthalic dianhydride, 4,4′-oxydiphthalic Acid dianhydrides are preferred. Aromatic tetracarboxylic acids may be used alone, or two or more of them may be used in combination. When heat resistance is emphasized, the aromatic tetracarboxylic acid is, for example, preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and still more preferably It is 80% by mass or more.

Alicyclic tetracarboxylic acids include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,3,4-cyclohexanetetracarboxylic acid, 1 , 2,4,5-cyclohexanetetracarboxylic acid, 3,3′,4,4′-bicyclohexyltetracarboxylic acid, bicyclo[2,2,1]heptane-2,3,5,6-tetracarboxylic acid, Bicyclo[2,2,2]octane-2,3,5,6-tetracarboxylic acid, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid, tetrahydroanthracene -2,3,6,7-tetracarboxylic acid, tetradecahydro-1,4:5,8:9,10-trimethanoanthracene-2,3,6,7-tetracarboxylic acid, decahydronaphthalene-2 ,3,6,7-tetracarboxylic acid, decahydro-1,4:5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic acid, decahydro-1,4-ethano-5,8-methano naphthalene-2,3,6,7-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetra Carboxylic acid (also known as "norbornane-2-spiro-2'-cyclopentanone-5'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid"), methylnorbornane- 2-spiro-α-cyclopentanone-α'-spiro-2''-(methylnorbornane)-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclohexanone- α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid (aka "norbornane-2-spiro-2'-cyclohexanone-6'-spiro-2''-norbornane -5,5″,6,6″-tetracarboxylic acid”), methylnorbornane-2-spiro-α-cyclohexanone-α′-spiro-2″-(methylnorbornane)-5,5″, 6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclopropanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane -2-spiro-α-cyclobutanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cycloheptanone-α' -spiro-2' '-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cyclooctanone-α'-spiro-2''-norbornane-5,5'',6 ,6″-tetracarboxylic acid, norbornane-2-spiro-α-cyclononanone-α′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic acid, norbornane-2- Spiro-α-cyclodecanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-cycloundecanone-α'-spiro- 2″-norbornane-5,5″,6,6″-tetracarboxylic acid, norbornane-2-spiro-α-cyclododecanone-α′-spiro-2″-norbornane-5,5″ ,6,6″-tetracarboxylic acid, norbornane-2-spiro-α-cyclotridecanone-α′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic acid, norbornane-2-spiro-α-cyclotetradecanone-α′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic acid, norbornane-2-spiro-α-cyclopenta Decanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic acid, norbornane-2-spiro-α-(methylcyclopentanone)-α'-spiro- 2″-norbornane-5,5″,6,6″-tetracarboxylic acid, norbornane-2-spiro-α-(methylcyclohexanone)-α′-spiro-2″-norbornane-5,5′ tetracarboxylic acids such as ',6,6''-tetracarboxylic acid, and acid anhydrides thereof. Among these, dianhydrides having two acid anhydride structures are preferred, particularly 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic acid Acid dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride is preferred, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic An acid dianhydride is more preferred, and 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride is even more preferred. In addition, these may be used independently and may use 2 or more types together. When transparency is emphasized, for example, the alicyclic tetracarboxylic acid is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and even more preferably 70% by mass or more of the total tetracarboxylic acids. is 80% by mass or more.

The polyamic acid solution may contain tricarboxylic acids and dicarboxylic acids.

Tricarboxylic acids include aromatic tricarboxylic acids such as trimellitic acid, 1,2,5-naphthalenetricarboxylic acid, diphenylether-3,3′,4′-tricarboxylic acid, and diphenylsulfone-3,3′,4′-tricarboxylic acid. acids or hydrogenated products of the above aromatic tricarboxylic acids such as hexahydrotrimellitic acid; Glycol bistrimellitate, and their monoanhydrides and esters. Among these, monoanhydrides having one acid anhydride structure are preferred, and trimellitic anhydride and hexahydrotrimellitic anhydride are particularly preferred. In addition, these may be used individually and may be used in combination.

Dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, 4,4'-oxydibenzenecarboxylic acid, or the above aromatic dicarboxylic acids such as 1,6-cyclohexanedicarboxylic acid. Hydrogenates of oxalic acid, succinic acid, glutaric acid, adipic acid, heptanedioic acid, octanedioic acid, azelaic acid, sebacic acid, undecadeic acid, dodecanedioic acid, 2-methylsuccinic acid, and their acid chlorides Alternatively, an esterified product and the like can be mentioned. Among these, aromatic dicarboxylic acids and hydrogenated products thereof are preferred, and terephthalic acid, 1,6-cyclohexanedicarboxylic acid, and 4,4'-oxydibenzenecarboxylic acid are particularly preferred. In addition, dicarboxylic acids may be used alone or in combination.

Diamines or isocyanates for obtaining highly colorless and transparent polyimides are not particularly limited, and polyimide synthesis, polyamideimide synthesis, aromatic diamines, aliphatic diamines, and alicyclic diamines commonly used in polyamide synthesis. , aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and the like can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and from the viewpoint of transparency, alicyclic diamines are preferred. In addition, the use of aromatic diamines having a benzoxazole structure makes it possible to exhibit high heat resistance, high elastic modulus, low thermal shrinkage, and low coefficient of linear expansion. Diamines and isocyanates may be used alone or in combination of two or more.

Examples of aromatic diamines include 2,2′-dimethyl-4,4′-diaminobiphenyl, 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene, 1,4-bis (4-amino-2-trifluoromethylphenoxy)benzene, 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl, 4,4′-bis(4-aminophenoxy)biphenyl, 4, 4′-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy) phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3 -hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 4-amino-N-(4-aminophenyl)benzamide, 3,3' -diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-trifluoromethyl-4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4' -diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1, 2-bis[4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]propane, 1,2-bis[4-(4-aminophenoxy)phenyl] propane, 1,3-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,1-bis[4-(4-aminophenoxy)phenyl]butane, 1,3-bis[4-(4-aminophenoxy) Phenyl]butane, 1,4-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,3-bis[4-(4 -aminophenoxy)phenyl]butane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3-methylphenyl]propane, 2,2-bis[4-( 4-aminophenoxy)-3-methylphenyl]propane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2, 2-bis[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3 -hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis (4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfoxide, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, 1,3-bis[4- (4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 4,4' -bis[(3-aminophenoxy)benzoyl]benzene, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4-(3-aminophenoxy)phenyl]propane, 3 ,4'-diaminodiphenyl sulfide, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, bis[4-(3-aminophenoxy ) phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1, 2-bis[4-(3-aminophenoxy)phenyl]ethane, bis[4-(3-aminophenoxy)phenyl]sulfoxide, 4,4′-bis[3-(4-aminophenoxy)benzoyl]diphenyl ether, 4 , 4′-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether, 4,4′-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4′-bis[ 4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone, 1,4-bis[4-(4-amino phenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino -6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene, 1,3- Bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-cyanophenoxy)-α,α-dimethylbenzyl] benzene, 3,3'-diamino-4,4'-diphenoxybenzophenone, 4,4'-diamino-5,5'-diphenoxybenzophenone, 3,4'-diamino-4,5'-diphenoxybenzophenone, 3,3′-diamino-4-phenoxybenzophenone, 4,4′-diamino-5-phenoxybenzophenone, 3,4′-diamino-4-phenoxybenzophenone, 3,4′-diamino-5′-phenoxybenzophenone, 3 ,3′-diamino-4,4′-dibiphenoxybenzophenone, 4,4′-diamino-5,5′-dibiphenoxybenzophenone, 3,4′-diamino-4,5′-dibiphenoxybenzophenone, 3,3 '-diamino-4-biphenoxybenzophenone, 4,4'-diamino-5-biphenoxybenzophenone, 3,4'-diamino-4-biphenoxybenzophenone, 3,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis(3-amino-4-phenoxybenzoyl)benzene, 1,4-bis(3-amino-4-phenoxybenzoyl)benzene, 1,3-bis(4-amino-5- phenoxybenzoyl)benzene, 1,4-bis(4-amino-5-phenoxybenzoyl)benzene, 1,3-bis(3-amino-4-biphenoxybenzoyl)benzene, 1,4-bis(3-amino- 4-biphenoxybenzoyl)benzene, 1,3-bis(4-amino-5-biphenoxybenzoyl)benzene, 1,4-bis(4-amino-5-biphenoxybenzoyl)benzene, 2,6-bis[ 4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzonitrile, 4,4′-[9H-fluorene-9,9-diyl]bisaniline (also known as “9,9-bis(4-aminophenyl) fluorene”), spiro(xanthene-9,9′-fluorene)-2,6-diylbis(oxycarbonyl)]bisaniline, 4,4′-[spiro(xanthene-9,9′-fluorene)-2,6- Diylbis(oxycarbonyl)]bisaniline, 4,4′-[spiro(xanthene-9,9′-fluorene)-3,6-diylbis(oxycarbonyl)]bisaniline, and hydrogen atoms on the aromatic rings of the above aromatic diamines part or all of is a halogen atom, an alkyl or alkoxyl group having 1 to 3 carbon atoms, a cyano group, or some or all of the hydrogen atoms of an alkyl or alkoxyl group are substituted with halogen atoms, and 1 to 1 carbon atoms and aromatic diamines substituted with a halogenated alkyl group or alkoxyl group of 3, and the like. Further, the aromatic diamines having a benzoxazole structure are not particularly limited, and examples thereof include 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl)benzoxazole, oxazole, 5-amino-2-(m-aminophenyl)benzoxazole, 6-amino-2-(m-aminophenyl)benzoxazole, 2,2′-p-phenylenebis(5-aminobenzoxazole), 2 , 2′-p-phenylenebis(6-aminobenzoxazole), 1-(5-aminobenzoxazolo)-4-(6-aminobenzoxazolo)benzene, 2,6-(4,4′-diamino diphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(4,4'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole , 2,6-(3,4′-diaminodiphenyl)benzo[1,2-d:5,4-d′]bisoxazole, 2,6-(3,4′-diaminodiphenyl)benzo[1,2 -d: 4,5-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3 ,3′-diaminodiphenyl)benzo[1,2-d:4,5-d′]bisoxazole and the like. Among these, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 4-amino-N-(4-aminophenyl)benzamide, 4,4′-diaminodiphenylsulfone, 3,3 '-Diaminobenzophenone is preferred. Incidentally, the aromatic diamines may be used singly or in combination.

Alicyclic diamines include, for example, 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propyl cyclohexane, 1,4-diamino-2-isopropylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino-2-sec-butylcyclohexane, 1,4-diamino-2-tert-butylcyclohexane, 4,4'-methylenebis(2,6-dimethylcyclohexylamine) and the like. Among these, 1,4-diaminocyclohexane and 1,4-diamino-2-methylcyclohexane are particularly preferred, and 1,4-diaminocyclohexane is more preferred. Incidentally, the alicyclic diamines may be used alone or in combination.

Diisocyanates include, for example, diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3' - or 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2 '- or 5,3'- or 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4, 3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-3, 3′-diisocyanate, diphenylmethane-3,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate, benzophenone-4,4′-diisocyanate, diphenylsulfone-4,4′-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4′-(2,2 bis(4-phenoxyphenyl)propane) diisocyanate, 3, 3'- or 2,2'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'- or 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4, Aromatic diisocyanates such as 4'-diisocyanate, 3,3'-diethoxybiphenyl-4,4'-diisocyanate, and diisocyanates obtained by hydrogenating any of these (e.g., isophorone diisocyanate, 1,4-cyclohexane diisocyanate , 1,3-cyclohexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate) and the like. Among them, diphenylmethane-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, 3,3'- Dimethylbiphenyl-4,4'-diisocyanate, naphthalene-2,6-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and 1,4-cyclohexane diisocyanate are preferred. Diisocyanates may be used alone or in combination.

As the solvent, any solvent can be used as long as it can dissolve the polyimide or the precursor of the polyimide, and an aprotic polar solvent or the like can be preferably used. For example, N,N-di-lower alkyl carboxylamides such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylmethoxyacetamide, N-methyl-2-pyrrolidone , N-ethyl-2-pyrrolidone, dimethylsulfoxide, dimethylsulfone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, diglyme, m-cresol, hexamethylphosphoramide, N-acetyl-2-pyrrolidone , hexamethylphosphoramide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, p-chlorophenol and the like. The solvent may be a mixture of two or more.

The second resin composition solution is not particularly limited as long as it has a higher tear strength than the first resin composition solution when forming a film, for example, polyimide resin composition solution, polyamide system resin composition solution, polyamide-imide system resin composition solution, and the like. Among them, when a polyimide resin composition solution is employed as the first resin composition solution, the polyimide resin composition solution is also used as the second resin composition solution from the viewpoint of close heat resistance. It is preferable to use It is preferable that the second resin composition solution has heat resistance equal to or higher than that of the first resin composition solution.

The second polyimide resin composition solution may be a polyamic acid (polyimide precursor) solution or a polyimide solution. When a polyamic acid solution is used, heat treatment is performed in step F to cause a dehydration ring-closing reaction to form a polyimide film. When a polyimide solution is used, the solvent is volatilized in step C to form a polyimide film.

The polyamic acid solution is obtained by reacting diamines and tetracarboxylic dianhydrides in a solvent.

Examples of the tetracarboxylic acids include aromatic tetracarboxylic acids (including their acid anhydrides), aliphatic tetracarboxylic acids (including their acid anhydrides), alicyclic tetracarboxylic acids (including their acid anhydrides), which are commonly used in polyimide synthesis. anhydrides) can be used. Among them, aromatic tetracarboxylic anhydrides and alicyclic tetracarboxylic anhydrides are preferred. Tetracarboxylic acids may be used alone, or two or more of them may be used in combination.

Examples of alicyclic tetracarboxylic acids include alicyclic tetracarboxylic acids such as cyclobutanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and 3,3′,4,4′-bicyclohexyltetracarboxylic acid. Carboxylic acids, and their acid anhydrides. Among these, dianhydrides having two anhydride structures (for example, cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 3,3′,4,4 '-bicyclohexyltetracarboxylic dianhydride) are preferred. The alicyclic tetracarboxylic acids may be used alone, or two or more of them may be used in combination.
The alicyclic tetracarboxylic acid is, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the total tetracarboxylic acids when transparency is important.

Examples of aromatic tetracarboxylic acids include, but are not limited to, pyromellitic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, and 4,4′-oxydiphthalic dianhydride. , 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride, 2,2-bis[4-(3,4 -dicarboxyphenoxy)phenyl]propanoic anhydride and the like.
The aromatic tetracarboxylic acid is, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the total tetracarboxylic acids when heat resistance is important.

The diamines are not particularly limited, and aromatic diamines, aliphatic diamines, and the like, which are commonly used in polyimide synthesis, can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and among aromatic diamines, aromatic diamines having a benzoxazole structure are more preferred. The use of aromatic diamines having a benzoxazole structure makes it possible to exhibit high heat resistance, high elastic modulus, low thermal shrinkage, and low coefficient of linear expansion. Diamines may be used alone or in combination of two or more.

Aromatic diamines having a benzoxazole structure are not particularly limited, and examples include 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl)benzoxazole, 5 -amino-2-(m-aminophenyl)benzoxazole, 6-amino-2-(m-aminophenyl)benzoxazole, 2,2'-p-phenylenebis(5-aminobenzoxazole), 2,2' -p-phenylenebis(6-aminobenzoxazole), 1-(5-aminobenzoxazolo)-4-(6-aminobenzoxazolo)benzene, 2,6-(4,4'-diaminodiphenyl)benzo [1,2-d:5,4-d′]bisoxazole, 2,6-(4,4′-diaminodiphenyl)benzo[1,2-d:4,5-d′]bisoxazole, 2, 6-(3,4′-diaminodiphenyl)benzo[1,2-d:5,4-d′]bisoxazole, 2,6-(3,4′-diaminodiphenyl)benzo[1,2-d: 4,5-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3,3' -diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole and the like.

Examples of aromatic diamines other than the above aromatic diamines having a benzoxazole structure include 2,2′-dimethyl-4,4′-diaminobiphenyl, 1,4-bis[2-(4-aminophenyl )-2-propyl]benzene (bisaniline), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 4,4 '-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl ] sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl ]-1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3′- Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4' -diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4, 4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[ 4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]propane, 1, 2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl] Propane, 1,1-bis[4-(4-aminophenoxy)phenyl]butane, 1,3- bis[4-(4-aminophenoxy)phenyl]butane, 1,4-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,3-bis[4-(4-aminophenoxy)phenyl]butane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3-methylphenyl]propane , 2,2-bis[4-(4-aminophenoxy)-3-methylphenyl]propane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3 ,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1 , 1,1,3,3,3-hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-amino phenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4- (4-aminophenoxy)phenyl]sulfoxide, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl] ether, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-amino phenoxy)benzoyl]benzene, 4,4'-bis[(3-aminophenoxy)benzoyl]benzene, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4-( 3-aminophenoxy)phenyl]propane, 3,4′-diaminodiphenyl sulfide, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane , bis[4-(3-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane , bis[4-(3-aminophenoxy)phenyl]sulfoxide, 4,4′-bis[ 3-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[4-(4-amino-α,α-dimethyl benzyl)phenoxy]benzophenone, 4,4′-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone , 1,4-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene , 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-fluorophenoxy)- α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino- 6-cyanophenoxy)-α,α-dimethylbenzyl]benzene, 3,3′-diamino-4,4′-diphenoxybenzophenone, 4,4′-diamino-5,5′-diphenoxybenzophenone, 3,4 '-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3 ,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'-diamino -4,5'-dibiphenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone, 4,4'-diamino-5-biphenoxybenzophenone, 3,4'-diamino-4-biphenoxybenzophenone, 3 ,4'-diamino-5'-biphenoxybenzophenone, 1,3-bis(3-amino-4-phenoxybenzoyl)benzene, 1,4-bis(3-amino-4-phenoxybenzoyl)benzene, 1,3 -bis(4-amino-5-phenoxybenzoyl)benzene, 1,4-bis(4-amino-5-phenoxybenzoyl)benzene, 1,3-bis(3-amino-4-biphenyl noxybenzoyl)benzene, 1,4-bis(3-amino-4-biphenoxybenzoyl)benzene, 1,3-bis(4-amino-5-biphenoxybenzoyl)benzene, 1,4-bis(4- amino-5-biphenoxybenzoyl)benzene, 2,6-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzonitrile, and some of the hydrogen atoms on the aromatic rings of said aromatic diamines or all of which are halogen atoms, alkyl or alkoxyl groups having 1 to 3 carbon atoms, cyano groups, or halogen atoms having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of an alkyl or alkoxyl group are substituted with halogen atoms and aromatic diamines substituted with alkyl groups or alkoxyl groups.

Examples of the aliphatic diamines include 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane and the like.
Examples of the aliphatic diamines include 1,4-diaminocyclohexane and 4,4'-methylenebis(2,6-dimethylcyclohexylamine).
The total amount of diamines other than aromatic diamines (aliphatic diamines) is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, based on all diamines. In other words, aromatic diamines are preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of all diamines.

As the solvent, the same solvent as described in the section of the first resin composition solution can be used.

[Film before cutting]
The film before cutting according to this embodiment is
a central portion composed of a first resin composition;
Having both ends formed continuously from the central part at both ends of the central part,
The both ends are made of a second resin composition different from the first resin composition,
The tear strength of the both end portions is greater than the tear strength of the central portion.

The pre-cut film can be obtained through the steps A to C of the resin film manufacturing method according to the present embodiment.
Here, the "first resin composition" refers to the composition (sheet material) after drying the first resin composition solution in the step C, and the "second resin composition" It refers to the composition (sheet-like material) after drying the second resin composition solution in the step C above.

The tear strength of the central portion is preferably in the range of 0.1 to 15 N/mm, more preferably in the range of 1 to 10 N/mm, as measured by the following measuring method.

The tear strength at both ends is preferably in the range of 0.5 to 30 N/mm, more preferably in the range of 1 to 20 N/mm, as measured by the following measuring method.
Moreover, the tear strength of the both ends is preferably more than 1 times and 10 times or less, more preferably more than 1.1 times and 5 times or less of the tear strength of the central portion.

<Method for measuring tear strength>
According to the trouser tearing method described in JIS K7128-1, the test speed is 200 mm/min, and the average value of the remaining 50 mm after excluding 20 mm at the start of tearing and 5 mm before the end of tearing is taken as the tear strength.
[Tear strength (N / mm)] = [Tear strength of test piece (N)] / [Thickness of test piece (d)]

The width of the both ends (the width of each end) is not particularly limited as long as it is a width that can be gripped by a conventionally known tenter-type conveying device, and is generally 5 mm or more, preferably 10 mm. That's it. The upper limit of the width is not particularly limited, and for example, the total width of both ends may be 50% or less, more preferably 30% or less, and still more preferably 10% or less of the total width of the film.
The width of the both ends (the width of each end) is not particularly limited as long as it is a width that can be gripped by a conventionally known tenter-type conveying device. It is 0.1% or more, more preferably 0.5% or more, and still more preferably 1% or more. The upper limit of the width is not particularly limited, and for example, the sum of the widths at both ends may be 50% or less, more preferably 30% or less, and still more preferably 10% or less of the total width of the film.

The pre-cut film according to the present embodiment has been described above.

Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[Synthesis Example 1 (Preparation of polyamic acid solution A)]
After replacing the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod with nitrogen, 1470.8 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was placed in the reaction vessel under a nitrogen atmosphere. (CBDA), 775.6 parts by weight of 4,4'-oxydiphthalic acid (ODPA), 3202.4 parts by weight of 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (TFMB), 5448. 8 parts by mass of dimethylacetamide-dispersed silica sol (Nissan Chemical's DMAc-ST) and 21795 parts by mass of N,N-dimethylacetamide were charged and dissolved, and then stirred at room temperature for 24 hours to give a solid content of 17.2 mass. A polyamic acid solution A having a reduced viscosity of 4.5 dl/g was obtained.

[Synthesis Example 2 (Preparation of Polyimide Solution B)]
After replacing the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring bar with nitrogen, 551 parts by mass of N,N-dimethylacetamide (DMAC) and 64.1 parts by mass of N,N-dimethylacetamide (DMAC) were placed in the reaction vessel under a nitrogen atmosphere. 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (TFMB) was added and stirred to dissolve TFMB in DMAC. Then, while stirring the inside of the reaction vessel, under a nitrogen stream, 44.4 parts by mass of 4,4'-(2,2-hexafluoroisopropylidene) diphthalic dianhydride (6FDA) and 29.4 Part by mass of biphenyltetracarboxylic dianhydride (BPDA) was added over about 10 minutes, and the polymerization reaction was carried out by continuing stirring for 6 hours while adjusting the temperature so that the temperature ranged from 20 to 40 ° C., A viscous polyamic acid solution was obtained.
Next, after adding 410 parts by mass of DMAC to the resulting polyamic acid solution to dilute it, 25.83 parts by mass of isoquinoline was added as an imidization accelerator, and the polyamic acid solution was heated to 30 to 40°C while stirring. While keeping the temperature within the range, 122.5 parts by mass of acetic anhydride as an imidization agent is slowly added dropwise over about 10 minutes, and then the liquid temperature is kept at 30 to 40° C. and stirred for 12 hours. followed by a chemical imidization reaction to obtain a polyimide solution.
Next, the obtained imidizing agent and 1000 parts by mass of the polyimide solution containing the imidization accelerator are transferred to a reaction vessel equipped with a stirring device and a stirring blade, and stirred at a speed of 120 rpm at 15 to 25 ° C. and 1500 parts by mass of methanol was dropped at a rate of 10 g/min. When about 800 parts by mass of methanol was added, turbidity of the polyimide solution was confirmed, and precipitation of powdery polyimide was confirmed. Subsequently, 1500 parts by mass of methanol was added to complete the deposition of polyimide. Subsequently, the contents of the reaction vessel were filtered using a suction filtration device, and washed and filtered using 1000 parts by mass of methanol. After that, 50 parts by mass of the filtered polyimide powder was dried at 50° C. for 24 hours using a dryer equipped with a local exhaust device, and further dried at 260° C. for 2 hours to remove the remaining volatile components. , to obtain a polyimide powder. The resulting polyimide powder had a reduced viscosity of 2.1 dl/g. Next, 42 parts by mass of the obtained polyimide powder was dissolved in 168 parts by mass of DMAC to obtain a polyimide solution B with a solid content of 20 parts by mass.

[Synthesis Example 3 (Preparation of Polyimide Solution C)]
124.15 parts by mass of 4,4′-diaminodiphenylsulfone (4,4′ -DDS), 124.15 parts by weight of 3,3′-diaminodiphenylsulfone (3,3′-DDS), and 750 parts by weight of gamma-butyrolactone (GBL) were added. Subsequently, 248.18 parts by mass of 4,4'-oxydiphthalic anhydride (ODPA), 58.8 parts by mass of biphenyltetracarboxylic dianhydride, 335 parts by mass of GBL, and 390 parts by mass of toluene were added at room temperature. After addition, the internal temperature was raised to 160° C., and heat reflux was performed at 160° C. for 1 hour to effect imidation. After completion of imidization, the temperature was raised to 180° C., and the reaction was continued while extracting toluene. After reacting for 12 hours, the oil bath was removed, the temperature was returned to room temperature, and 1149 parts by mass of GBL was added so that the solid content was 20 parts by mass, thereby obtaining a polyimide solution C having a reduced viscosity of 0.6 dl/g.

[Synthesis Example 4 (Preparation of polyamic acid solution D)]
384.38 parts by mass of norbornane-2-spiro-α-cyclopentanone-α′ was added while introducing nitrogen gas into a reaction vessel equipped with a nitrogen inlet tube, a Dean-Stark apparatus, a reflux tube, a thermometer and a stirring bar. - spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride (CpODA), 348.45 parts by weight of 9,9-bis(4-aminophenyl)fluorene ( BAFL), 36.00 parts by mass of triethylamine, 1465 parts by mass of N-methyl-2-pyrrolidone (NMP), 1465 parts by mass of gamma-butyrolactone (GBL), 360 parts by mass of toluene were added at room temperature, and then the internal temperature was The temperature was raised to 180° C., and imidization was performed by heating at 180° C. for 3 hours while toluene was distilled off to obtain a polyimide solution.
Next, 2,500 parts by mass of the obtained polyimide solution was transferred to a reaction vessel equipped with a stirrer and a stirring blade, maintained at a temperature of 15 to 25° C. while stirring at a speed of 120 rpm, and 50,000 parts by mass of acetone was added thereto. It was dropped at a rate of 10 g/min. Turbidity of the polyimide solution was confirmed when about 2,500 parts by mass was added, and deposition of powdery polyimide was confirmed. Subsequently, the remaining 2500 parts by mass of acetone was added to complete deposition of polyimide. Subsequently, the contents of the reaction vessel were filtered using a suction filtration device, and washed and filtered using 2000 parts by mass of methanol. After that, 300 parts by mass of the filtered polyimide powder was dried at 50° C. for 24 hours using a dryer equipped with a local exhaust device, and further dried at 260° C. for 2 hours to remove the remaining volatile components. , to obtain a polyimide powder. The polyimide powder thus obtained had a reduced viscosity of 0.7 dl/g. Next, 42 parts by mass of the obtained polyimide powder was dissolved in 168 parts by mass of NMP to obtain a polyimide solution D having a solid content of 20 parts by mass and a reduced viscosity of 0.7 dl/g.

[Synthesis Example 5 (preparation of polyamic acid solution E)]
After replacing the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod with nitrogen, 196.1 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was placed in the reaction vessel under a nitrogen atmosphere. (CBDA), 227.3 parts by mass of 4-amino-N-(4-aminophenyl)benzamide (DABAN), and 1694 parts by mass of N,N-dimethylacetamide were charged and dissolved, and then at room temperature. After stirring for 24 hours, a polyamic acid solution E having a solid content of 20 parts by mass and a reduced viscosity of 4.5 dl/g was obtained.

[Synthesis Example 6 (Preparation of polyamic acid solution F)]
After replacing the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod with nitrogen, 196.1 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was placed in the reaction vessel under a nitrogen atmosphere. (CBDA), 160.1 parts by weight of 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl (TFMB), 113.6 parts by weight of 4-amino-N-(4-aminophenyl)benzamide (DABAN), and 1879 parts by mass of N,N-dimethylacetamide were charged and dissolved, and then stirred at room temperature for 24 hours to give a solid content of 20 parts by mass and a polyamic acid solution F with a reduced viscosity of 4.5 dl / g. got

[Synthesis Example 7 (Preparation of polyamic acid solution G)]
After purging the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer and a stirring rod with nitrogen, 2002.4 parts by mass of 4,4'-diaminodiphenyl ether was charged. Next, 16647 parts by mass of N,N-dimethylacetamide was added and completely dissolved, and then 2159.4 parts by mass of pyromellitic dianhydride was added and stirred at a reaction temperature of 25°C for 15 hours to give a solid content of 20 mass. A brown, viscous polyamic acid solution G having a reduced viscosity of 3.5 dl/g was obtained.

[Synthesis Example 8 (Preparation of Polyamideimide Solution H)]
After purging the inside of the reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod, 153.7 parts by mass of trimellitic acid, 256.4 parts by mass of O-lysine diisocyanate, 3,3',4,4'- 29.4 parts by weight of biphenyltetracarboxylic dianhydride, 32.2 parts by weight of 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1 part by weight of triethylenediamine, and N-methyl-2- 1,671 parts by mass of pyrrolidone was added, and the mixture was heated to 130° C. over 1 hour while stirring, and further reacted at 130° C. for 5 hours to obtain a polyimide resin solution having a logarithmic viscosity of 1.6 dl/g. Snowtex (DMAC-ST, manufactured by Nissan Kagaku Kogyo Co., Ltd.) obtained by dispersing colloidal silica in dimethylacetamide was added so that the amount of silica was 0.5 parts by mass, and a solution H was obtained.

[Synthesis Example 9 (Preparation of Polyamic Acid Solution J)]
After replacing the inside of a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirring rod with nitrogen, 980.6 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride was placed in the reaction vessel under a nitrogen atmosphere. (CBDA), 1029 parts by weight of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 465.3 parts by weight of 4,4′-oxydiphthalic acid (ODPA), 3202.4 Parts by mass of 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl (TFMB) and 32171 parts by mass of N,N-dimethylacetamide were charged and dissolved, and then stirred at room temperature for 24 hours to initiate the polymerization reaction. to obtain a polyamic acid solution J having a reduced viscosity of 3.50 dl/g.

[Reduced viscosity]
The reduced viscosities (dL/g) of the prepared polyamic acid solutions A, D to F, and the polyimide solutions B and C were obtained by adding 0.02 g of each sample to 10 mL of a mixed solvent (phenol/tetrachloroethane = 60/40 (mass ratio)). and measured at 30° C. using an Uberose viscometer.

( Reference example 1)
A polyamic acid solution A (Synthesis Example 1) and a polyamic acid solution G (Synthesis Example 7) were prepared. Using the comma coater shown in FIGS. 1 and 2, the clearance was adjusted so that the polyamic acid solution A had a final film thickness of 25 μm on a PET film (A4100 manufactured by Toyobo Co., Ltd.) with a central width of 500 mm. Simultaneously with the application, the polyamic acid solution G was applied to the width of 50 mm on each of both ends. At this time, the width of the side plate used was 10 mm.
Then, it was dried at 100 to 110° C. for 10 minutes to form a polyamic acid film, and after drying, it was wound around a 6-inch ABS core together with the PET film to obtain a polyamic acid film roll. A polyamic acid film and a PET film were unwound from the obtained polyamic acid film roll, and the self-supporting polyamic acid film was peeled off from the PET film to obtain a polyamic acid film.
The obtained polyamic acid film is passed through a pin tenter having pin sheets arranged so that the pin intervals are constant when the pin sheets are lined up, and the edge of the film is gripped by inserting the pins, and the film is broken. Adjust the distance between the pin sheets so as not to cause unnecessary sagging, and convey so that the final distance between the pin sheets is 520 mm. Heating was performed for 3 minutes, 300° C. for 3 minutes as the third stage, and 350° C. for 3 minutes as the fourth stage to advance the imidization reaction. After that, the film was cooled to room temperature for 2 minutes, and then the edges of the film formed by the polyamic acid solution G were slit to leave only the central portion to obtain a polyimide film having a thickness of 25 μm and a width of 480 mm.

( Reference example 2)
A polyamic acid solution A (Synthesis Example 1) and a polyamic acid solution G (Synthesis Example 7) were prepared. Polyamic acid solution G was applied onto both ends of a mirror-finished stainless steel belt using a comma coater shown in FIGS. The clearance was adjusted so that it was applied. At this time, the coating was applied so that the width of the central portion was 1000 mm and the width of both ends was 50 mm.
Then, it was dried at 100 to 110° C. for 10 minutes and peeled off from the support after drying to obtain a self-supporting polyamic acid film.
The obtained pre-cut film is passed through a pin tenter having pin sheets arranged so that the pin intervals are constant when the pin sheets are lined up, and the ends of the film are gripped by inserting the pins into the pins to break the film. Adjust the distance between the pin sheets so as not to cause unnecessary sagging, and convey so that the final distance between the pin sheets is 1000 mm. Heating was performed for 3 minutes, 300° C. for 3 minutes as the third stage, and 350° C. for 3 minutes as the fourth stage to advance the imidization reaction. After that, it was cooled to room temperature for 2 minutes, then the edge of the film formed by the polyamic acid solution G was slit to leave only the central portion, and the film was continuously wound into a roll on a 3-inch ABS resin core to obtain a thickness of A polyimide film of 25 μm, 980 mm wide and 500 m long was obtained.

( Reference example 3)
A polyamic acid solution A (Synthesis Example 1) and a polyamic acid solution G (Synthesis Example 7) were prepared. Polyamic acid solution G was applied onto both ends of a mirror-finished stainless steel belt using a T-die shown in FIGS. I applied it after adjusting the clearance. At this time, the coating was applied so that the width of the central portion was 1000 mm and the width of both ends was 50 mm.
Then, it was dried at 100 to 110° C. for 10 minutes and peeled off from the support after drying to obtain a self-supporting polyamic acid film.
The obtained pre-cut film is passed through a pin tenter having pin sheets arranged so that the pin intervals are constant when the pin sheets are lined up, and the ends of the film are gripped by inserting the pins into the pins to break the film. Adjust the distance between the pin sheets so as not to cause unnecessary sagging, and convey so that the final distance between the pin sheets is 520 mm. Heating was performed for 3 minutes, 300° C. for 3 minutes as the third stage, and 350° C. for 3 minutes as the fourth stage to advance the imidization reaction. After that, it was cooled to room temperature for 2 minutes, then the edge of the film formed by the polyamic acid solution G was slit to leave only the central portion, and the film was continuously wound into a roll on a 3-inch ABS resin core to obtain a thickness of A polyimide film of 25 μm, 980 mm wide and 500 m long was obtained.

( Reference example 4)
A polyimide solution B (Synthesis Example 2) and a polyamic acid solution G (Synthesis Example 7) were prepared. A polyimide film having a thickness of 12.5 μm and a width of 480 mm was obtained in the same manner as in Reference Example 1 except that instead of the polyimide solution A, the polyimide solution B was applied with the clearance adjusted so that the final film thickness was 12.5 μm. rice field.

( Reference example 5)
A polyimide solution C (synthesis example 3) and a polyamideimide solution H (synthesis example 8) were prepared. Instead of polyimide solution A, polyimide solution C was applied by adjusting the clearance so that the final film thickness was 12.5 μm, and polyamideimide solution H was used instead of polyamic acid solution G (Synthesis Example 7). A polyimide film having a thickness of 12.5 μm and a width of 480 mm was obtained in the same manner as in Example 1.

( Reference example 6)
A polyamic acid solution D (Synthesis Example 4) and a polyamic acid solution G (Synthesis Example 7) were prepared. A polyimide film having a thickness of 25 μm and a width of 480 mm was obtained in the same manner as in Reference Example 1 except that instead of the polyimide solution A, the polyamic acid solution D was applied so as to adjust the clearance so that the final film thickness was 25 μm.

( Reference example 7)
A polyamic acid solution E (Synthesis Example 5) and a polyamic acid solution G (Synthesis Example 7) were prepared. A polyimide film having a thickness of 25 μm and a width of 480 mm was obtained in the same manner as in Reference Example 1 except that instead of the polyimide solution A, the polyamic acid solution E was applied so as to adjust the clearance so that the final film thickness was 25 μm.

( Reference example 8)
A polyamic acid solution F (Synthesis Example 6) and a polyamic acid solution G (Synthesis Example 7) were prepared. A polyimide film having a thickness of 25 μm and a width of 480 mm was obtained in the same manner as in Reference Example 1, except that instead of the polyimide solution A, the polyamic acid solution F was applied so as to adjust the clearance so that the final film thickness was 25 μm.

( Reference example 9)
A polyamic acid solution J (Synthesis Example 9) and a polyamic acid solution G (Synthesis Example 7) were prepared. A polyimide film having a thickness of 25 μm and a width of 480 mm was obtained in the same manner as in Reference Example 1, except that instead of the polyimide solution A, the polyamic acid solution J was applied while adjusting the clearance so that the final film thickness was 25 μm.

(Comparative example 1)
Polyamic acid solution A (Synthesis Example 1) was applied to a PET film (A4100 manufactured by Toyobo Co., Ltd.) as a support using a comma coater while adjusting the clearance so that the film had a width of 600 mm and a final film thickness of 25 μm. .
Then, it was dried at 100 to 110° C. for 10 minutes and peeled off from the support after drying to obtain a self-supporting polyamic acid film.
The obtained polyamic acid film is passed through a pin tenter having pin sheets arranged so that the pin intervals are constant when the pin sheets are lined up, and the edge of the film is gripped by inserting the pins, and the film is broken. Adjust the distance between the pin sheets so as not to cause unnecessary sagging, and convey so that the final distance between the pin sheets is 520 mm. Heating was performed for 3 minutes, 300° C. for 3 minutes as the third stage, and 350° C. for 3 minutes as the fourth stage to advance the imidization reaction. Thereafter, the film was cooled to room temperature for 2 minutes, and when an attempt was made to remove it from the pin sheet, the holes through which the pins were passed were broken, and a film could not be obtained.

(Comparative Examples 2 to 6)
Instead of Synthesis Example 1 used in Comparative Example 1, the same operation as in Comparative Example 1 was performed except that each resin of Synthesis Examples 2 to 6 was used, and attempts were made to produce films of Comparative Examples 2 to 6. When an attempt was made to remove the film from the pin sheet, the holes through which the pins were passed were broken, and the film could not be obtained.

<Film thickness measurement>
The thickness of the film was measured using a micrometer (Millitron 1245D manufactured by Fineruff Co.).

<Tear strength>
The tear strength at the central portion and the tear strength at both ends of the uncut films obtained in Reference Examples and Comparative Examples were determined. Specifically, according to the trouser tearing method described in JIS K7128-1, the test speed was 200 mm / min, and the average value of the remaining 50 mm excluding 20 mm at the start of tearing and 5 mm before the end of tearing was taken as the tear strength. Tables 1 and 2 show the results.
[Tear strength (N / mm)] = [Tear stress of test piece (N)] / [Thickness of test piece (d)]

The tear strength obtained here (tear strength described in Tables 1 and 2) is the tear strength of the polyimide film (resin film) after step G, but in the polyimide film after step G, the second If the tear strength of the portion formed from the resin composition solution is greater than the tear strength of the portion formed from the first resin composition solution, naturally the cutting after step C and before step F Also in the front film, the tear strength of the portion formed from the second resin composition solution is higher than the tear strength of the portion formed from the first resin composition solution.
The tear strength of the central portion of the uncut film after step C of Reference Example 8 and before step F was measured by the same method as above, and was 1.8 N/mm. From this also, in the polyimide film after step G, if the tear strength of the portion formed from the second resin composition solution is greater than the tear strength of the portion formed from the first resin composition solution , After the step C and before the step F, the tear strength of the portion formed from the second resin composition solution was less than the tear strength of the portion formed from the first resin composition solution. It is clear that it will be greater than the strength.

In the polyimide films of Reference Examples 1 to 9, the tear strength of the portion formed from the second resin composition solution is greater than the tear strength of the portion formed from the first resin composition solution, so the rupture after heat treatment. and there was no deformation. On the other hand, the pre-cut films of Comparative Examples 1 to 6 were films formed from a single resin composition solution with low tear strength, so the holes through which the pins were passed were torn, and the films were broken. couldn't get.

10, 30, 40, 50 coating device 12 backup roll 14 comma roll 16 (16a, 16b, 16c) coating liquid reservoir 18 (18a, 18b, 18c, 18d) side plate 20 back plate 22 gap 60 support 62 (62a) , 62b, 62c) Coating liquid 64 (64a, 64b, 64c) Coating film

Claims (1)

a central portion composed of a first resin composition;
Having both ends formed continuously from the central part at both ends of the central part,
The both ends are made of a second resin composition different from the first resin composition,
The tear strength at both ends is greater than the tear strength at the central portion,
The pre-cut film, wherein the first resin composition is a polyamide-based resin or a polyamideimide-based resin.

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