TW201338956A - Solution casting method and device, casting die, and film producing method and apparatus - Google Patents

Abstract

A first solution and a second solution with different viscosities are cast on a support from a casting die to form a casting film. The casting die is provided with a first flow channel for flowing the first solution and a second flow channel for flowing the second solution. Downstream ends of the first and second flow channels are connected to a discharge port. The flow of the first solution and the flow of the second solution are joined together in the vicinity of the discharge port, and cast on the support from the discharge port. An uppermost stream point at which the first solution and the second solution are joined together is referred to as P1. A length L1 of the casting die between the uppermost point P1 and the discharge port is in the range of not less than 0 mm to not more than 5 mm.

Description

Casting method and device, casting die, film manufacturing method and device

The invention relates to a casting method and device for casting a film or a film, a casting die, a film manufacturing method and a device, relating to two kinds of solutions having different co-casting viscosities.

Among the sheet members used for optical devices such as liquid crystal displays, members made of polymer films are mostly used. Most polymer films produce defects due to contact or friction with other articles. Therefore, in the sheet member, the sheet member on which the hard coat layer (hard coat film) is provided on the polymer film is mostly to prevent scratches or the like from occurring in the manufacturing process or use of the optical device.

The hard coat film is formed by coating a coating film on which a hard coat layer is formed on a polymer film, and subjecting it to a predetermined curing process for the coated film. As the curing process, a process of irradiating light to the coating film to cure the cured component contained in the coating film can be mentioned. For example, Japanese Laid-Open Patent Publication No. 2001-205179 describes a method of curing by irradiation with ultraviolet rays.

A composition of a composition which has been cured by irradiation with light has been proposed so far. For example, a putty composition which is cured by irradiation with near-infrared light is described in Japanese Patent Laid-Open Publication No. Hei 09-137089. The putty composition contains a polymerizable unsaturated group-containing resin, a polymerizable unsaturated compound, and a near-infrared photopolymerization initiator.

Further, a composition in which a component which is cured by irradiation with light is used as a solution component of a solution film is also proposed. For example, Japanese Patent Publication No. 2002-020410 discloses a solution composition containing an ethylenically unsaturated monomer.

On the other hand, in the method of producing a hard coat film by coating a coating liquid for forming a hard coat layer on a polymer film, a process for forming a polymer film and a process for forming a hard coat layer are required. Process, there is a problem of poor manufacturing efficiency.

In order to solve such a problem, a method of co-casting a first solution for forming a film main body composed of a polymer and a second solution for forming a hard coat layer has been studied. As a method of co-casting, for example, Japanese Patent Publication No. 2003-103547 discloses that a plurality of solutions having different compositions are combined in a casting die and then cast on a traveling support, thereby being simultaneously formed by one process. A method of multilayer film. Further, Japanese Laid-Open Patent Publication No. 2003-103547 discloses an example in which the distance from the portion where the solution is merged to the discharge port at the tip end of the casting die is set to be within 50 mm.

However, if a first solution for forming a film main body and a second solution for forming a hard coat layer are co-cast in a conventional apparatus as described in Japanese Laid-Open Patent Publication No. 2003-103547, it is difficult to apply hard coating. The thickness of the layer is set to be constant.

That is, in the method of Japanese Laid-Open Patent Publication No. 2003-103547, it is premised that the solution to be cast forms a cellulose ester film, that is, a solution having the same degree of viscosity. Therefore, the distance from the merging portion of the solution to the discharge port is large, and the distance from the merging portion of the solution to the discharge port is not more than 30 mm (refer to Japanese Patent Laid-Open Publication No. 2003-103547 [0048] ). In addition, the distance from the merging portion to the discharge port is, for example, about 30 mm, and the method described in Japanese Laid-Open Patent Publication No. 2003-103547, when the solutions of the same degree of viscosity are combined, the force of the solutions being pressed against each other Since it is equal, it is easy to make the layer thickness of each solution constant.

On the other hand, the viscosity of the first solution which is usually used for forming the film main body is higher than the viscosity of the second solution for forming the hard coat layer. When the solutions having different viscosities are combined in this manner, the force at which the first solution presses the second solution is large, and the second solution is pushed away by the first solution. Therefore, when the distance from the merging portion to the discharge port is, for example, about 30 mm, it is difficult to maintain the film thickness of the second solution constant until it reaches the discharge port.

Accordingly, it is an object of the present invention to provide a casting method and apparatus, a casting die, a film manufacturing method and apparatus which can make a thickness of a layer formed of a solution having a low viscosity constant even if the viscosity of a solution is different.

The casting method of the present invention includes a joining step and a casting step, and discharges the first solution and the second solution from the discharge port of the casting die to form a cast film on the support. The joining step merges the first solution and the second solution at the joining portion of the casting die. The viscosity of the second solution is lower than that of the first solution. The distance from the most upstream side joining point to the discharge port is in the range of 0 mm or more and 5 mm or less. The most upstream side merge point is the most upstream end of the junction. In the casting step, the first solution and the second solution which are joined are cast on the traveling support to form a cast film.

The viscosity X of the first solution and the viscosity Y of the second solution satisfy X/Y 10 is preferred.

The viscosity of the first solution is at most 100 Pa. s is preferred.

The viscosity of the second solution is at most 10 Pa. s is preferred.

It is preferable that the distance from the discharge port to the support is 3 mm or less.

It is preferable that the second solution is guided to the merging portion by the slit-like flow path, and the flow path is long in the width direction of the casting film, and the gap is 1 mm or less.

The film production method of the present invention includes a joining step, a casting step, and a film forming step, and a film is produced from the cast film. The cast film is formed by discharging the first solution and the second solution from the discharge port of the casting die to the support. The joining step merges the first solution and the second solution at the joining portion of the casting die. The viscosity of the second solution is lower than the first solution described above. The distance from the most upstream side joining point to the discharge port is in the range of 0 mm or more and 5 mm or less. The most upstream side merge point is the most upstream end of the junction. In the casting step, the first solution and the second solution which are joined are cast on the traveling support to form a cast film. The film forming step forms a film by peeling the cast film from the support.

The casting die of the present invention includes a first flow path, a second flow path, a merging portion, and a discharge port. The first solution flows in the first flow path. The second solution having a lower viscosity than the first solution flows in the second flow path. The merging portion merges the first solution flow of the first flow path with the second solution flow of the second flow path. The first solution and the second solution are discharged from the discharge port. The distance from the most upstream side joining point to the discharge port is in the range of 0 mm or more and 5 mm or less. The most upstream side merge point is the most upstream end of the junction.

The casting device of the present invention includes a casting die, a first flow path, a second flow path, a merging portion, a discharge port, and a support. The first mold and the second solution are discharged from the casting die. The first flow path is provided in the casting die and the first solution flows therein. The second flow path is provided in the casting die, and the second solution flows therein. The viscosity of the second solution is lower than that of the first solution. The merging portion merges the first solution flow of the first flow path with the second solution flow of the second flow path. The merging portion is disposed in the casting die. The discharge port is placed in the casting die, and the first solution and the second solution are discharged. The distance from the most upstream side joining point to the discharge port is in the range of 0 mm or more and 5 mm or less. The most upstream side merge point is the most upstream end of the junction. The support is cast with the first solution and the second solution.

The film manufacturing apparatus of the present invention includes a casting die, a first flow path, a second flow path, a merging portion, a discharge port, a support, and a drying device. The first mold and the second solution are discharged from the casting die. The first flow path is provided in the casting die and the first solution flows therein. The second flow path is provided in the casting die and the second solution flows therein. The viscosity of the second solution is lower than that of the first solution. The merging portion merges the first solution flow of the first flow path with the second solution flow of the second flow path. The merging portion is disposed in the casting die. The discharge port is placed in the casting die and the first solution and the second solution are discharged. The distance from the most upstream side joining point to the discharge port is in the range of 0 mm or more and 5 mm or less. The most upstream side merge point is the most upstream end of the junction. The support is cast into the first solution and the second solution to form a cast film. The drying device dries the cast film peeled off from the support to form a film.

According to the present invention, even when the viscosity ratios of the first solution and the second solution are different, the thickness of the layer formed of the solution having a low viscosity can be made constant.

10‧‧‧casting device

12‧‧‧Support

14‧‧‧Deferred mode

16‧‧‧1st solution

18‧‧‧Second solution

20‧‧‧ spitting

22‧‧‧cast film

22a‧‧‧ grassroots

22b‧‧‧hard coating

28‧‧‧1st flow path

30‧‧‧2nd flow path

50‧‧‧hard coating film

60‧‧‧Film manufacturing equipment

62‧‧‧Drying Department

64‧‧‧ Wet film

68‧‧‧roll

70‧‧‧ tenter

72‧‧‧ clip

74‧‧‧Air duct

76‧‧‧Resection device

78‧‧‧roll

80‧‧‧ drying room

82‧‧‧Dry film

84‧‧‧Curing device

86‧‧‧Winding Department

88‧‧‧Volume core

P1‧‧‧ the most upstream side convergence point

L1‧‧‧ Distance from the most upstream junction to the spout

L2‧‧‧ Distance from the spit to the support

W1‧‧‧ slit gap of the first flow path

W2‧‧‧ slit gap of the second flow path

WE‧‧‧Slit gap in the spout

Figure 1 is a schematic view of a casting device.

Figure 2 is a cross-sectional view of a casting die.

Figure 3 is a cross-sectional view of the front end portion of the casting die.

Figure 4 is a cross-sectional view of the front end portion of the casting die.

Fig. 5 is a cross-sectional view showing a front end portion of a casting die.

Fig. 6 is a schematic view of a film manufacturing apparatus.

Fig. 1 shows an example of a casting device 10 of the present invention. The casting device 10 is provided with a support 12 and a casting die 14. As the support body 12, for example, a rotary drum or the like is used. The casting die 14 merges the flow of the first solution 16 (the first solution flow) and the flow of the second solution 18 (the second solution flow). After the joining, the casting die 14 is formed by flowing it from the discharge port 20 (refer to FIG. 2) formed at the front end to the traveling support body 12. That is, the casting device 10 is formed by forming a cast film 22 by a known co-casting method.

The first solution 16 is the base layer 22a on which the casting film 22 is formed. The first solution 16 has a viscosity of, for example, 100 Pa. Below s, the maximum is 100Pa. The polymer solution of s is composed. On the other hand, the second solution 18 is a hard coat layer 22b which forms the casting film 22. The second solution 18 is such that at least one of the monomer and the oligomer is dissolved in the solvent and has a viscosity of 10 Pa. Below s, the maximum is 10Pa. s solution. The viscosity ratio of the first solution 16 to the second solution 18 is set to 10:1 or more (when the viscosity of the first solution is X and the viscosity of the second solution is Y, X/Y is satisfied). 10). Further, examples of the monomer and the oligomer include a curing agent which is cured by ultraviolet rays, a curable polymerization agent, and the like.

As shown in FIG. 2, in the casting die 14, a first supply port 24, a second supply port 26, a first flow path 28, and a second flow path 30 are formed in addition to the discharge port 20. The first solution 16 is supplied from the first supply port 24, and the second solution 18 is supplied from the second supply port 26. The first flow path 28 and the second flow path 30 are slit-shaped flow paths which are long in the shape of the cross section orthogonal to the direction in which the solution flows, along the width direction of the casting film 22 (the depth direction of the first and second figures). Further, the first flow path 28 is formed to connect the first supply port 24 and the discharge port 20, and the second flow path 30 is formed to connect the second supply port 26 and the discharge port 20.

In the casting die 14, the end portions on the most downstream side of the first flow path 28 and the second flow path 30 are connected to the discharge port 20, and the first solution 16 and the second solution 18 are in the vicinity of the discharge port 20 ( After the merging portion is merged, it is discharged from the discharge port 20 to the support body 12.

In addition, as shown in FIG. 3 in which the tip end portion of the casting die 14 is enlarged, the most upstream side of the merging portion where the first solution 16 and the second solution 18 are in contact is referred to as the most upstream side merging point P1. In the casting die 14, the distance L1 from the most upstream side joining point P1 to the discharge port 20 is set to be in a range of 0 mm or more and 5 mm or less, which is extremely shorter than that of a general co-casting apparatus. Further, the smaller the distance L1, the better, and the 0 mm is the best.

In the casting die 14, the slit gap W2 of the second flow path 30, that is, the thickness of the second flow path 30 (the gap of the slit) is set to 1 mm or less. In the casting device 10, the casting die 14 is provided such that the distance L2 between the discharge port 20 and the support 12 is 3 mm or less.

The distance L1 from the most upstream side joining point P1 to the discharge port 20 is 0 mm or more and 5 mm or less, and the distance L1 is extremely short compared to a general co-casting apparatus. Therefore, even if the viscosity ratio of the first solution 16 to the second solution 18 is 10:1 or more, it is less likely to be affected by the second solution flow being pressed by the first solution flow, and the thickness of the hard coat layer 22b becomes uniform.

In addition, since the slit gap W2 of the second flow path 30 is set to 1 mm or less, the second solution 18 having a low viscosity is prevented from flowing endlessly, and the thickness of the hard coat layer 22b is uniform. In the present invention, as described above, it is less likely to be affected by the pressing of the first solution flow. Therefore, the slit gap W is preferably narrower, and specifically, 1 mm or less is preferable. Thus, the second solution stream The thickness of the hard coat layer 22b becomes uniform as it is stably joined to the first solution stream.

Further, in the casting device 10, the distance L2 from the discharge port 20 to the support 12 is set to 3 mm or less. Therefore, the thickness of the hard coat layer 22b becomes more reliably uniform. In other words, when the distance from the discharge port 20 to the support 12 is increased, the second solution 18 having a lower viscosity than the first solution 16 may not be maintained in thickness during the fall from the discharge port 20 to the support 12, and may not be desired. The film thickness is uneven, and the film thickness becomes uneven in the substrate transport direction (longitudinal direction of the casting film 22). However, since the distance L2 is set to 3 mm or less in the casting device 10, such a problem can be prevented.

In order to confirm the effect of the casting apparatus of the present invention, the comparative example 2 in which the distance L1 is 35 mm, the comparative example 2 in which the distance L1 is 20 mm, the first embodiment in which the distance L1 is 5 mm, and the distance L1 are set. Casting was performed in Example 1 of 0 mm, respectively. Further, in all of the comparative examples and the examples of the examples, the viscosity of the first solution 16 was 80 Pa. s, as the second solution 18, the viscosity is 4mPa. s. As a result, as shown in the following Table 1, it was confirmed in Examples 1 and 2 that the thickness of the hard coat layer 22b can be made constant. Further, the gloss unevenness of the surface was visually confirmed. When the gloss unevenness could not be confirmed, it was judged that the thickness of the hard coat layer 22b was constant and it was evaluated as "A (qualified)". When the gloss unevenness was confirmed, it was judged that the thickness of the hard-coat layer 22b was not constant, and it was judged as "B (fail).".

In the present invention, the viscosity of the first solution and the second solution may be different from each other, and the distance L1 from the most upstream side to the discharge portion may be 0 mm or more and 5 mm or less. Therefore, the detailed configuration is not limited to the above embodiment, and can be appropriately changed. For example, the specific viscosity of the first solution and the second solution or the slit gap W2 of the second flow path can be appropriately changed. Further, the effect of the present invention is more remarkable when the viscosity ratio of the first solution and the second solution is 10:1 or more, but it is not necessarily required to be 10:1 or more. Further, the effect is more remarkable when the distance L2 from the discharge port to the support is 3 mm or less, but it is not necessarily required to be 3 mm or less.

Further, although not specified in the above embodiment, the slit gap of the discharge port can be appropriately set. For example, as shown in FIG. 4, the slit gap WE of the discharge port 20 can be made equal to the slit gap W1 of the first flow path 28. In addition, FIG. 5 shows a state in which the slit gap WE of the discharge port 20 is the same as the total of the slit gap W1 of the first flow path 28 and the slit gap W2 of the second flow path 30. In this way, it can be set to WE=W1+W2. In the fourth and fifth embodiments, the same members as those in the above-described embodiments are denoted by the same reference numerals, and their description will be omitted.

However, when the slit gap WE is smaller than the slit gap W1, the second solution 18 is pressed by the first solution 16, and it is difficult to join the second solution 18 or to make the layer thickness of the hard coat layer 22b constant. Therefore, it is preferable that the slit gap WE is equal to or larger than the slit gap W1.

When the slit gap WE is larger than the total of the slit gap W1 and the slit gap W2, the adhesion between the first solution 16 and the second solution 18 is lowered. Therefore, it is preferable that the slit gap WE is equal to or less than the total of the slit gap W1 and the slit gap W2.

As described above, the slit gap WE is preferably equal to or smaller than the slit gap W1 and the total of the slit gap W1 and the slit gap W2. However, when WE<W1+W2, the adhesion of the first solution 16 and the second solution 18 may be increased as necessary, and the quality of the hard coat film (refer to reference numeral 50 in Fig. 6) of the product may be deteriorated. That is, compared with the method of applying the second solution 18 to the base layer to form a hard coat layer after drying the base layer (Dry on Wet), the base layer 22a and the hard layer are simultaneously formed by co-casting (Wet on Wet) as in the present invention. In the method of coating 22b, the fluidity of the first solution 16 is high, and diffusion between the first and second solutions 16 and 18 occurs, and the first solution 16 is formed between the base layer 22a and the hard coat layer 22b. The second solution 18 is mixed with the mixed layer. Therefore, the adhesion is originally high. Therefore, when WE<W1+W2 is formed, diffusion of more than necessary may occur, and the mixed layer may become too thick, and the hardness of the hard coat film may fall or white turbidity may occur. Therefore, the most preferable gap slit WE is "WE=W1+W2". Thus, the thickness of the hard coat layer was set to be constant, and the base layer and the hard coat layer were moderately adhered.

Further, in the above embodiment, an example in which the present invention is applied to a casting apparatus in which the first solution 16 and the second solution 18 are co-cast is described. However, the present invention may be applied to the first solution 16 and A casting device in which a third solution (not shown) is co-cast is used in addition to the second solution 18.

Further, a temperature control mechanism for adjusting the temperature of the peripheral surface of the support body 12 by heating or cooling the support body 12 may be provided in the casting device. Further, a decompression chamber can be provided on the upstream side in the rotation direction of the support body 12 in the vicinity of the casting die 14, and the comparative casting die 14 is further decompressed on the upstream side in the rotation direction of the support body 12. Further, a blower that blows air in the circumferential direction of the support body 12 or a duct that flows the wind from the blower along the outer circumference of the support body 12 may be provided. Further, when air is blown along the outer circumference of the support body 12, it is preferable to blow air in a direction opposite to the moving direction of the support body 12.

Hereinafter, a film manufacturing apparatus 60 for manufacturing a hard coat film 50 by the above-described casting device 10 (refer to FIG. 1) will be described with reference to FIG. In the film manufacturing apparatus 60, a drying section 62 is provided on the downstream side of the casting apparatus 10. The casting film 22 formed on the support 12 by the casting device 10 is made into the wet film 64 by cooling the support 12, for example. Then, the wet film 64 is peeled off from the support 12, and is sent to the drying unit 62 by the roller 68.

A tenter 70 is provided in the dryer 62. In the tenter 70, a plurality of clips 72 as holding means for holding the side end portions of the wet film 64 are disposed on both sides of the conveying path of the wet film 64, respectively. When the wet film 64 cannot withstand the grip based on the clip 72, for example, when the content of the solvent is too high and the crack is caused by the grip, the needle can be used instead of the clip 72, and the needle is pierced at the side end of the wet film 64. Thereby, the wet film 64 is maintained.

A plurality of clips 72 are provided on a chain (not shown) that continuously travels. The travel trajectory of the clip 72 can be changed by the displacement of the travel path of the chain. The distance between the clip 72 and the clip 72 respectively disposed on both sides of the wet film 64 can be appropriately adjusted to limit the width of the wet film 64.

The tenter 70 is provided with a blow duct 74 that blows dry air whose temperature is adjusted to the wet film 64. Drying of the wet film 64 during conveyance by the clip 72 is performed by the air blow of the air supply duct 74.

Further, when the belt can be supported by the circumferential surface of the roller and conveyed by the rotation of the roller, the tenter 70 may not be disposed.

The wet film 64 that has been released by the gripper 72 is guided to the cutting device 76 provided downstream of the tenter 70. The wet film 64 has a trace of holding on the holding position held by the clip 72. The cutting device 76 continuously shears the side end portion of the wet film 64 so that the holding trace separates from the central portion of the hard coat film 50 which becomes the product.

The downstream of the cutting device 76 is provided with a plurality of rollers 78 that support the wet film 64 whose both end portions are cut by the circumferential surface, and has a drying chamber 80 to which dry air is supplied. The roller 78 includes a driving roller that conveys the wet film 64 by rotational driving in the circumferential direction. The supplied dry air is adjusted to a predetermined temperature and humidity, and the wet film 64 is thoroughly dried by further drying the dry air. The degree of "completeness" is the degree of dryness to the extent that the product is not problematic, and the residual amount of the solvent may not necessarily be 0 (zero). Such a thorough drying is referred to as a dry film 82 in the following description.

The dried film 82 that has passed through the drying section 62 is sent to the curing device 84. The curing device 84 has a light source that emits ultraviolet light, which irradiates ultraviolet light from the light source to the guided dry film 82. The curable compound is cured by the irradiation. When the curable compound is a polymerized by irradiation, the polymerization process corresponds to a curing process.

Further, the curing device 84 may be provided in the casting device 10, the tenter 70, and the drying chamber 80 instead of being disposed downstream of the drying unit 62 of the present embodiment. That is, any one of the casting film 22, the wet film 64, and the dry film 82 can be irradiated with ultraviolet rays. In this manner, at least one of the casting film 22, the wet film 64, and the dried film 82 may be irradiated with ultraviolet rays.

The portion corresponding to the hard coat layer 22b described above is cured by irradiation of ultraviolet rays from the curing device 84, and a hard coat layer is formed on one surface of the film main body corresponding to the base layer 22a. Thus, a hard coat film 50 composed of a film main body and a hard coat layer was obtained. Then, the obtained hard coat film 50 is wound in a roll shape on a winding core 88 provided in the winding portion 86.

Hereinafter, the cellulose halide, the curable compound, and the curing agent used in the solution of the present application will be described.

[Cellulose Telluride]

The cellulose halide is a ratio of the hydroxyl group of the cellulose esterified by a carboxylic acid, that is, the degree of substitution of the thiol group (hereinafter, referred to as a thiol substitution degree) satisfies all the conditions of the following formulas (1) to (3). Especially good. Further, in (1) to (3), both A and B are thiol substitution degrees, the fluorenyl group in A is an acetamidine group, and the fluorenyl group in B is a carbon atom number of 3 to 22.

The glucose unit constituting cellulose and β-1,4 linkage has a free hydroxyl group at the 2, 3 and 6 positions. The cellulose halide is a polymer in which a part or all of the hydroxyl group of the cellulose is esterified and the hydrogen of the hydroxyl group is substituted with a mercapto group of carbon 2 or more. In addition, if the esterification of one of the hydroxyl groups in the glucose unit is 100%, the degree of substitution is 1, so when it is a cellulose halide, if the hydroxyl groups at the 2, 3, and 6 positions are respectively 100% esterified , the degree of substitution becomes 3.

In addition, the degree of substitution of the thiol group at the 2-position in the glucose unit is DS2, the degree of substitution of the thiol group at the 3-position is DS3, and the degree of substitution of the thiol group at the 6-position is DS6, which is obtained by "DS2+DS3+DS6". The total thiol substitution degree is preferably 2.00 to 3.00, more preferably 2.22 to 2.90, and 2.40 to 2.88 is further preferred. Further, "DS6/(DS2+DS3+DS6)" is preferably 0.32 or more, more preferably 0.322 or more, and further preferably 0.324 to 0.340.

The thiol group may be one type or two or more types. When the fluorenyl group is two or more types, one of them is preferably an acetamino group. The sum of the degree of substitution of the ethylidene group based on the hydrogen of the hydroxyl group at the 2, 3, and 6 positions is taken as DSA, and the sum of the substitution degrees of the fluorenyl group other than the ethyl group in the 2, 3, and 6 positions is set. For DSB, the value of "DSA+DSB" is preferably 2.2~2.86, and especially 2.40~2.80. A DSB of 1.50 or more is preferred, and a 1.7 or more is particularly preferred. Further, it is preferable that 28% or more of DSB is a hydroxyl group at the 6-position, but more preferably 30% or more, more preferably 31% or more, and particularly preferably 32% or more. Further, the value of "DSA + DSB" at the 6-position of the cellulose halide is preferably 0.75 or more, more preferably 0.80 or more, and particularly preferably 0.85 or more. By using the cellulose halide as described above, it is possible to obtain a preferable solubility for producing a polymer solution used for film formation in a solution, and to produce a polymer solution having better filterability and a low viscosity. In particular, when a non-chlorinated organic solvent is used, a cellulose halide as described above is preferred.

The mercapto group of carbon 2 or more may be an aliphatic group or an aryl group, and is not particularly limited. For example, there may be an alkylcarbonyl ester of cellulose, an olefinic carbonyl ester or an aromatic carbonyl ester, an aromatic alkylcarbonyl ester, etc., which may each further have a substituted group. Examples thereof include a fluorenyl group, a butyl group, a pentyl group, a hexyl group, a decyl group, a decyl group, a dodecyl fluorenyl group, a tridecyl fluorenyl group, a tetradecane fluorenyl group, a hexadecane group, an octadecane group. Anthracenyl, isobutyl fluorenyl, tert-butyl fluorenyl, cyclohexanecarbonyl, anthracenyl, benzamyl, naphthalenecarbonyl and cinnamyl. Among them, a propyl sulfonyl group, a decyl fluorenyl group, a dodecyl fluorenyl group, an octadecyl fluorenyl group, a tert-butyl fluorenyl group, an oil fluorenyl group, a benzamidine group, a naphthalene carbonyl group and a cinnamyl group are more preferable .

[curable compound]

The curable compound may be any one of a monomer and an oligomer. The curable compound preferably contains a polyfunctional acrylate. As the monomer, dipentaerythritol hexaacrylate (DPHA) represented by the following formula (I) is preferred. As the oligomer, urethane acrylate is more preferable. DPHA and urethane acrylate can also be used in combination.

Further, as the curable compound, an ionizing radiation curable polyfunctional monomer or a polyfunctional oligomer can be used. As a functional group of such a polyfunctional monomer or a polyfunctional oligomer, light, electron beam, and radiation polymerizability are preferred, and a photopolymerizable functional group is preferred.

The photopolymerizable functional group may, for example, be an unsaturated polymerizable functional group such as a (meth)acryl fluorenyl group, a vinyl group, a styryl group or an allyl group, and a (meth) acrylonitrile group is preferred.

In order to impart brittleness to the hard coat layer, an oligomer and/or a polymer having a weight average molecular weight of 500 or more may be added.

Examples of the oligomer and the polymer include a (meth)acrylate type, a cellulose type, a styrene type polymer, a urethane acrylate, a polyester acrylate, and the like. Preferred are polyglycidyl methacrylate or polyallyl methacrylate having a functional group in the side chain.

The content of the oligomer and/or the polymer in the hard coat layer is preferably from 5 to 80% by mass based on the total mass of the hard coat layer, more preferably from 25 to 70% by mass, particularly preferably from 35 to 65% by mass.

[Hardener]

As the curing agent, a well-known photopolymerization initiator can be used. For example, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinyl-1-propanone is preferred. The concentration of the curing agent is preferably in the range of 1% by mass or more and 8% by mass or less based on the mass of the curable compound. The concentration of the curing agent is {V11/Z11}×100 when the mass of the curable compound is set to Z11 and the mass of the curing agent is set to V11. Find the value.

Further, examples of the photoradical polymerization initiator include acetophenones, benzoin, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, and azo compounds. Oxide, 2,3-dialkyl ketone compounds, disulfide compounds, fluoroamine compounds or aromatic quinones. Examples of the acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylbenzophenone, 1-hydroxycyclohexenone, 2-methyl- 4-Methylthio-2-morpholinylpropiophenone and 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone. Examples of benzoin include benzoin benzenesulfonate, benzoin tosylate, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether. Examples of benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone, and p-chlorobenzophenone. Examples of the phosphine oxides include 2,4,6-trimethylbenzimidyldiphenylphosphine oxide.

Various examples are also described in the latest UV curing technology (P. 159, Issuer; Takahiro Shino, Distribution Office; Technical Information Institute Co., Ltd., issued in 1991), which is useful for the present invention.

As a commercially available photo-cleavage-type photo-radical polymerization initiator, a preferred example is Yanjiagu (651, 184, 907) manufactured by Ciba Specialty Chemicals Co., Ltd.

Further, as described in Japanese Patent Laid-Open No. Hei 6-41468, it is also preferred to use two photopolymerization initiators in combination.

The photopolymerization initiator is preferably used in an amount of 0.1 to 15 parts by mass, more preferably in an amount of 1 to 10 parts by mass, based on 100 parts by mass of the polyfunctional monomer.

A photosensitizer can also be used on the basis of the photopolymerization initiator. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone, and thioxanthone.

Further, it may be polymerized by heating instead of or in addition to a photopolymerization initiator.

12‧‧‧Support

14‧‧‧Deferred mode

20‧‧‧ spitting

28‧‧‧1st flow path

30‧‧‧2nd flow path

L1‧‧‧ Distance from the most upstream junction to the spout

L2‧‧‧ Distance from the spit to the support

P1‧‧‧ the most upstream side convergence point

W2‧‧‧ slit gap of the second flow path

Claims (17)

A casting method in which a first solution and a second solution are discharged from a discharge port of a casting die to form a cast film on a support, wherein the method includes the step of: causing the first solution and the second solution to be in the foregoing The merging portion of the casting die merges, wherein the viscosity of the second solution is lower than the first solution, and the distance from the most upstream side joining point to the discharge port is in a range of 0 mm or more and 5 mm or less, and the most upstream side joining point It is an end portion on the most upstream side of the merging portion; and the first solution and the second solution which are joined together are cast on the traveling support to form a cast film. The casting method according to claim 1, wherein the viscosity X of the first solution and the viscosity Y of the second solution satisfy X/Y 10. The casting method according to claim 1 or 2, wherein the viscosity of the first solution is at most 100 Pa. s. The casting method according to claim 1 or 2, wherein the viscosity of the second solution is at most 10 Pa. s. The casting method according to claim 3, wherein the viscosity of the second solution is at most 10 Pa. s. The casting method according to claim 1 or 2, wherein a distance from the discharge port to the support is 3 mm or less. The casting method according to claim 3, wherein the distance from the discharge port to the support is 3 mm or less. The casting method according to Item 4, wherein the distance from the discharge port to the support is 3 mm or less. The casting method according to claim 5, wherein the distance from the discharge port to the support is 3 mm or less. The casting method according to claim 1 or 2, wherein the second solution is guided to the merging portion by a slit-like flow path, and the flow path is long along a width direction of the casting film. And the gap is 1 mm or less. The casting method described in claim 3, wherein The second solution is guided to the merging portion by a slit-like flow path, and the flow path is long in the width direction of the casting film, and the gap is 1 mm or less. The casting method according to the fourth aspect of the invention, wherein the second solution is guided to the merging portion by a slit-like flow path, the flow path being long along a width direction of the casting film, and a gap It is 1mm or less. The casting method according to claim 5, wherein the second solution is guided to the merging portion by a slit-like flow path, and the flow path is long along a width direction of the casting film, and a gap It is 1mm or less. In a method for producing a film, a film is produced from a cast film, wherein the cast film is formed by discharging a first solution and a second solution from a discharge port of a casting die to a support, and the film production method has the following steps: The first solution and the second solution are joined together at a merging portion of the casting die, wherein the viscosity of the second solution is lower than the first solution, and the distance from the most upstream side to the discharge port is 0 mm or more and 5 mm. In the following range, the most upstream side merge point is an end portion on the most upstream side of the merging portion; and the first solution and the second solution which are joined together are cast on the traveling support to form a cast film: The foregoing film is formed by peeling the above-mentioned cast film from the above support. A casting die comprising: a first flow path through which a first solution flows; a second flow path having a viscosity lower than a flow of a second solution of the first solution; and a merging portion to cause the first flow The first solution flow of the road merges with the second solution flow of the second flow path; and the discharge port discharges the first solution and the second solution, and the distance from the most upstream merge point to the discharge port is 0 mm or more and 5 mm. In the following range, the most upstream side merge point is the most upstream end of the merging portion. A casting device comprising: a casting die for discharging a first solution and a second solution; a first flow path provided in the casting die and flowing the first solution therein; and a second flow path; Provided in the casting die and the second solution flows therein, the second The viscosity of the solution is lower than the first solution; the merging portion merges the first solution flow of the first flow path with the second solution flow of the second flow path, and the merging portion is provided in the casting die; The first casting solution and the second solution are discharged from the casting die, and the distance from the most upstream side joining point to the discharge port is in a range of 0 mm or more and 5 mm or less, and the most upstream side joining point is the merging portion. The most upstream end portion; and the support body, the first solution and the second solution are cast. A film manufacturing apparatus comprising: a casting die that discharges a first solution and a second solution; a first flow path that is provided in the casting die and in which the first solution flows; and a second flow path Provided in the casting die and flowing the second solution therein, the viscosity of the second solution is lower than the first solution, and the merging portion is configured to make the first solution flow of the first flow path and the second flow path 2 a solution flow, the merging portion is provided in the casting die; the discharge port is provided in the casting die, and the first solution and the second solution are discharged, and the distance from the most upstream side to the discharge port is 0 mm In the range of 5 mm or less, the most upstream side merge point is an end portion on the most upstream side of the merging portion, and the support body is formed by casting the first solution and the second solution to form a cast film, and a drying device. The cast film peeled off from the support is dried to form a film.