KR20090102650A - Cycloolefin-based resin film and method of producing the same - Google Patents

Abstract

PURPOSE: A cycloolefin-based resin film and a method for producing the same are provided to ensure excellent handling titration with blending with slip ash. CONSTITUTION: A cycloolefin-based resin film comprises 50~2000/mm^2 of gel with 0.5μm - 3μm size per sphere with roundness of 0.7 or more/mm^2. The gel with the size of diameter 10μm or more per sphere with roundness of 0.7 or more/mm^2 is 10 or less/mm^2. A method for manufacturing a cycloolefin-based resin film formed by melting the cycloolefin-based resin comprises the steps of: mixing a lubricant 0.01~3.0wt%, a heat stabilizer 0.01~0.5wt%, and a pellet containing the cycloolefin-based resin heated to a glass transition temperature(Tg)~Tg+40°C, wherein the lubricant is the liquid state at glass-transition temperature or less of a lubricant or pellet having a melting point of a pellet; and plasticizing the mixture in the atmosphere of 0.1% - 10%.

Description

Cycloolefin resin film and its manufacturing method {CYCLOOLEFIN-BASED RESIN FILM AND METHOD OF PRODUCING THE SAME}

The present invention relates to a cycloolefin resin film and a method for producing the same, and more particularly, to a cycloolefin resin film produced by melting a pellet of a cycloolefin resin with an extruder and a method for producing the same.

Films made of cycloolefin-based resins (hereinafter referred to as "cycloolefin-based resin films") are attracting attention as films capable of improving hygroscopicity and moisture permeability of cellulose triacetate films. The manufacturing method is examined. In addition, the cycloolefin-based resin film has high optical properties and develops less optical properties due to temperature changes, and development as an optical film such as a retardation film (hereinafter also referred to as a "phase difference film") It is done. Such a film is produced by heating and melting pellets of cycloolefin resin by an extruder, discharging the molten resin from a die into a sheet, cooling it on a cooling drum, and peeling it.

However, in melt film formation of cycloolefin resin, a large amount of gel generate | occur | produced when melt-extruding with an extruder, and this remained as a foreign material failure by remaining on a cycloolefin resin film.

On the other hand, in order to reduce a gel, examination which gives the additive which inhibits oxidation, etc. has been made (for example, patent document 1 and 2).

[Patent Document 1] Japanese Unexamined Patent Publication No. 2007-160720

[Patent Document 2] Japanese Patent Application Laid-Open No. 7-14213

However, in the method of applying the additives for inhibiting oxidation described in Patent Documents 1 and 2, the gel of the cycloolefin resin is completely removed, resulting in poor slipperiness and deterioration in handling during film formation. there was. When handling property deteriorates, for example, cycloolefin resin will slide on a cooling drum, and the optical physical property of the cycloolefin resin film formed into a film will become nonuniform. Therefore, in order to prevent deterioration of handling property, a slip material is mix | blended normally.

This invention is made | formed in view of such a situation, The cyclo which can suppress the fall of the optical characteristic by generation | occurrence | production of a gel in the melt film forming of a cycloolefin resin film, and can provide the outstanding handling titration without mix | blending a slip material. It is an object to provide an olefinic resin film and a method for producing the same.

In order to achieve the above object, the invention according to claim 1 contains 50 to 2000 gels having a circular equivalent diameter of 0.5 µm or more and 3 µm or less in size, and has a circularity of 0.7 or more and a circular equivalent diameter of 10 µm. It is characterized by the above-mentioned gel being 10 pieces / mm <2> or less.

According to the invention of claim 1, in the cycloolefin-based resin film, the circular equivalent is a circle equivalent of 0.7 or more and contains 50 to 2000 gels / mm 2 of a micro size of 0.5 µm or more and 3 µm or less in diameter, and the circular equivalent is 0.7 or more. When the coarse gel having a size of 10 µm or more in diameter has a density of 10 pieces / mm 2 or less, the deterioration of the optical properties due to the generation of the gel can be suppressed, and excellent handling titration can be given without blending the slip material. That is, the cycloolefin-based resin film formed into a film contains a circular equivalent diameter of 0.7 or more and a circle size of 0.5 µm or more and 3 µm or less in 50 to 2000 pieces / mm 2 and a circular equivalent diameter of 0.7 or more. When the gel having a size of 10 μm or more is 10 pieces / mm 2 or less, the gel expressed by melting in the extruder does not interfere with the optical properties, and excellent handling titration can be given without blending the slip material. The cycloolefin resin film of can be provided.

Further, the gel having a circular equivalent diameter of 0.5 or more and 0.5 µm or more and 3 µm or less preferably has a density of 50 to 1000 pieces / mm 2 and more preferably 100 to 500 pieces / mm 2.

Invention of Claim 2 is a manufacturing method of the cycloolefin resin film which melts and forms a cycloolefin resin in order to achieve the said objective, Comprising: It is below the glass transition temperature of the lubricant or pellet which has melting | fusing point below the glass transition temperature of a pellet. 0.01-3.0 wt% of a lubricating agent in a liquid state, 0.01-0.5 wt% of a heat stabilizer, and a pellet containing a cycloolefin-based resin heated at a glass transition temperature (Tg) to Tg + 40 ° C., and the mixed mixture It is characterized in that the film is formed by plasticizing in an oxygen concentration of 0.1% or more and 10% or less.

According to claim 2, (a) a lubricant having a melting point of less than or equal to the glass transition temperature of the pellet, or 0.01 to 3.0 wt% of the lubricant in a liquid state below the glass transition temperature of the pellet, and (b) 0.01 to 0.5 wt% of the thermal stabilizer (c) ) Mix with pellets. (d) When uniformly mixing, the pellets of the cycloolefin-based resin are heated in the range of glass transition temperature (Tg) to Tg + 40 ° C of the pellets, and (e) the mixture is calcined in an atmosphere having an oxygen concentration of 0.1% or more and 10% or less. I make it angry and make a film. By satisfy | filling all the conditions of (a)-(e), film forming can be performed on the conditions which produce a micro gel. That is, it contains 50-2000 pieces / mm <2> of gels with a circular equivalent diameter of 0.5 micrometers or more and 3 micrometers or less with circularity of 0.7 or more, and 10 pieces / mm <2> of gels with a circular equivalent diameter of 10 micrometers or more of roundness of 0.7 or more You can do Therefore, the manufacturing method of the cycloolefin resin film which can impart the outstanding handling titration without mix | blending a slip material can be provided without the interference of an optical characteristic by the gel expressed by melting to an extruder. .

The invention according to claim 3 is characterized in that the pellet is an annular pellet without an angle in the invention according to claim 2.

In addition, the invention described in claim 4 is characterized in that, in the invention of claim 3, the annular pellet without angle is a pellet cut by hot cutting and underwater cutting.

According to claim 3, in order to further suppress the fall of the optical characteristic by the generation | occurrence | production of a gel, it is preferable that a pellet uses an annular pellet without an angle. By using an angular pellet without an angle, friction with cycloolefin resin (pellets) in an extruder can be reduced. Therefore, in particular, a gel having a circular equivalent diameter of 10 µm or more having a roundness of 0.7 or more can be further reduced. Further, according to claim 4, the pellets are manufactured by hot cutting and underwater cutting, whereby annular pellets without angles can be obtained well.

In the invention described in claim 5, in the invention according to any one of claims 2 to 4, the cycloolefin resin has a glass transition temperature (Tg) of 120 ° C or more.

According to Claim 5, it is preferable that glass transition temperature (Tg) of cycloolefin resin is 120 degreeC or more.

Invention of Claim 6 formed into a film by the touch-roll method in invention of any one of Claims 2-5, It is characterized by the above-mentioned.

This invention is especially effective when forming a cycloolefin resin by the touch roll method which cools molten resin with a touch roll. That is, the touch roll method is characterized in that unlike the polishing roller method of cooling the molten resin while sandwiched by a pair of rollers, the molten resin is easily slipped on the cooling drum, but the cycloolefin resin film according to the present invention is slippery. It is especially effective because it is difficult to slip.

Invention of Claim 7 is film range in 20-300 micrometers in invention of any one of Claims 2-6, It is characterized by the above-mentioned.

According to claim 7, in the case where the film thickness is in the range of 20 to 300 µm, the gel expressed by melting into the extruder does not interfere with the optical properties, and excellent handling titration can be given without blending the slip material. The manufacturing method of a cycloolefin resin film can be provided.

Claim 8 is a cycloolefin resin film characterized in that the cycloolefin resin of claim 1 is a norbornene-based resin, claim 9 is the cycloolefin resin is a norbornene-based resin, Claims 2 to 7 It is a manufacturing method of the cycloolefin resin film in any one of.

Norbornene-based resins, which are cycloolefin-based resins, have high optical properties and are suitable for optical compensation films and polarizing plates for liquid crystal displays.

(Effects of the Invention)

According to the present invention, a cycloolefin-based resin film and a method for producing the cycloolefin-based resin film which can impart excellent handling titration without blending a slip material without being impeded by the gel expressed by melting in an extruder. Can provide.

1 is a block diagram of a film production apparatus to which the present invention is applied.

2 is a schematic view showing the configuration of a hopper and an extruder.

3 is an explanatory diagram of an embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

10: film production apparatus 12: cycloolefin resin film

14: film forming process part 16: longitudinal drawing process part

18: lateral stretching step 20: winding step

22: extruder 24: die

26: cooling drum 32: cylinder

34: screw shaft 36: screw blade

38: screw 40: supply port

42: discharge port 44: hopper

44 ': vacuum hopper 46: piping

48: piping 50: vacuum pump

52: supply port A: supply unit

B: compression section C: weighing section

D: cylinder bore L: cylinder length

The cycloolefin-based resin film of the present invention contains 50 to 2000 gels / mm 2 having a circle equivalent diameter of 0.5 μm or more and 3 μm or less with a circularity of 0.7 or more, and a circular equivalent diameter of 10 μm or more with a circularity of 0.7 or more. It is characterized by having 10 gels / mm 2 or less.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of the manufacturing method for manufacturing the cycloolefin resin film which concerns on the said gel density condition according to an accompanying drawing is described.

1 has shown an example of schematic structure of the manufacturing apparatus of a cycloolefin resin film. As shown in FIG. 1, the manufacturing apparatus 10 mainly uses the film forming process part 14 which manufactures the cycloolefin resin film 12 before extending | stretching, and the cycloolefin resin manufactured by the film forming process part 14. By the longitudinal stretch process part 16 which longitudinally stretches the film 12, the transverse stretch process part 18 which transversely stretches, and the winding process part 20 which winds up the stretched cycloolefin resin film 12 It is composed.

In the film forming step 14, the cycloolefin resin melted by the extruder 22 is discharged from the die 24 into a sheet, cast on a rotating cooling drum 26 to be quenched and solidified to form a cycloolefin resin film ( 12) is obtained. After the cycloolefin resin film 12 is peeled from the cooling drum 26, the cycloolefin resin film 12 is sequentially transferred to the longitudinal stretching step 16 and the transverse stretching step 18 and stretched, and wound up at the winding step 20. It is wound up in roll shape. Thereby, the stretched cycloolefin resin film 12 is manufactured. Hereinafter, the detail of each process part is demonstrated.

2 has shown the structure of the extruder 22 of the film forming process part 16. As shown in FIG. As shown in the same figure, the extruder 22 is a single screw extruder and is provided with the single screw 38 in the cylinder 32. The single screw 38 is comprised by attaching the screw blade 36 to the screw shaft 34, is rotatably supported, and is rotationally driven by the motor which is not shown in figure.

A jacket (not shown) is attached to the outer circumferential portion of the cylinder 32 so that the temperature can be controlled at a desired temperature.

A hopper 42 is attached to the supply port 40 of the cylinder 32, and cycloolefin resin is supplied into the cylinder 32 through the supply port 40 from the hopper 42.

Here, the cycloolefin resin supplied in the hopper 42 is pelletized previously. In the present invention, the pellets are mixed with a lubricant having a melting point below the glass transition temperature of the pellet, or 0.01 to 3.0 wt% of a lubricant in a liquid state below the glass transition temperature of the pellet, and 0.01 to 0.5 wt% of a heat stabilizer to the extruder 22. Is supplied into the cylinder 32.

In addition, a lubricating agent here is what is generally called an external lubricant which has the effect of reducing the friction of resin and barrel and / or a screw in an extruder, For example, lauric acid and myristic Fatty acids such as acids, palmitic acid, stearic acid, arachidic acid, behenic acid, montanic acid, stearyl stearate, behenyl behenate, pentaerythritol tristearate, pentaerythritol tetrastearate, glycerin monostearate, glycerin monobehenate, etc. Fatty acid esters: fatty acid amides such as stearylamide, palmitylamide, oleylamide, methylenebisstearoamide, ethylenebisstearoamide, metal soaps such as calcium stearate and magnesium stearate, and natural waxes such as montan wax 1 or more types can be used. Especially, fatty acid ester is preferable. The fatty acid which forms a fatty acid ester needs to be a fatty acid ester which consists of a C12-36 fatty acid residue and a C1-C36 alcohol residue, Preferably it is a C16-32 fatty acid residue and a C1-C36 alcohol residue Fatty acid ester which consists of fatty acids, More preferably, it is a fatty acid ester which consists of a C16-C32 fatty acid residue and a C1-C20 alcohol residue.

The thermal stabilizer means having an antioxidant function and / or a radical trap function, and examples thereof include phenolic antioxidants, phosphorus antioxidants and sulfur antioxidants. Specific examples of the phenolic antioxidant include p-cyclohexylphenol, 3-t-butyl-4-methoxyphenol, 4,4'-isopropylidenediphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane Non-hindered phenolic antioxidants, 2-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-p-cresol, 2,4,6-tri-t-butylphenol, 4- Hydroxymethyl-2,6-di-t-butylphenol, styrenated phenol, 2,5-di-t-butylhydroquinone, octadecyl-3- (3,5-di-t-butyl-4-hydroxy Oxyphenyl) propionate, triethylene glycol bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediolbis [3- (3,5 -Di-t-butyl-4-hydroxyphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2 '-Methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (6-t-butyl-4-ethylphenol), 2,2'-methylenebis [4-methyl-6 -(1,3,5-trimethylhexyl) phenol], 4,4'-methylenebis (2,6-di-t-butylphen ), 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 2,6-bis (2-hydroxy-3-t-butyl-5-methylbenzyl) -4-methyl Phenol, 1,1,3-tris [2-methyl-4-hydroxy-5-t-butylphenyl] butane, 1,3,5-trimethyl-2,4,6-tris [3,5-di- t-butyl-4-hydroxybenzyl] benzene, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, tris [3- (3,5-di-t-butyl- 4-hydroxyphenyl) propionyloxyethyl] isocyanurate, 4,4'-thiobis (3-methyl-6-t-butylphenol), 2,2'-thiobis (4-methyl-6- Hindered phenolic antioxidants, such as t-butylphenol), 4,4'- thiobis (2-methyl-6-t-butylphenol), and thiobis ((beta) -naphthol), etc. are mentioned. In particular, the hindered phenol-based antioxidant can be suitably used as a radical trapping agent because it tends to itself become a stable radical. The molecular weight of the hindered phenol-based antioxidant is usually 200 or more, preferably 500 or more, and its upper limit is usually 3000.

Specific examples of sulfur-based antioxidants include didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthiopropionate) and thiobis (N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzoimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickel dibutyldithiocarbamate, Nickel isopropyl xanthate, trilauryl trithio phosphite, etc. are mentioned. In particular, a thioether antioxidant having a thioether structure can be preferably used because it receives oxygen from the oxidized material and reduces it. The molecular weight of the sulfur-based antioxidant is usually 200 or more, preferably 500 or more, and its upper limit is usually 3000.

Examples of the phosphorus antioxidant include triphenyl phosphite, diphenyldecyl phosphite, phenyl diisodecyl phosphite, tri (nonylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol dipot Spite, bis (2, 6- di-t- butyl- 4-methylphenyl) pentaerythritol diphosphite etc. are mentioned.

The pellets, glidants and heat stabilizers are warmed in the range of the glass transition temperature (Tg) to Tg + 40 ° C. of the pellets and glided to the warmed pellets before mixing the pellets, glidants and heat stabilizers for mixing. And a heat stabilizer, and these mixtures are mixed. Moreover, it is preferable that the glass transition temperature (Tg) of cycloolefin resin is 120 degreeC or more.

The pellet is preferably an annular pellet without an angle. Angleless annular pellets can be produced by cutting by hot cutting and underwater cutting. In order to further suppress the deterioration of the optical properties due to the generation of the gel, it is preferable that the pellets use circular pellets without angles. By using an angular pellet without an angle, friction with cycloolefin resin (pellets) in an extruder can be reduced.

The cylinder 32 in the extruder 22 is set to an atmosphere having an oxygen concentration of 0.1% or more and 10% or less. By allowing the oxygen concentration in the cylinder 32 to be 0.1% or more and 10% or less, it is possible to suppress the expression of the gel by oxidizing the cycloolefin resin at the time of melting. Particularly, the circularity is 0.7 or more, and the circular equivalent diameter is 10 μm. Expression of the gel of the above size can be suppressed. The oxygen concentration in the cylinder 32 is preferably 0.1% or more and 10% or less, more preferably 0.1% or more and 3% or less.

As a method of adjusting the oxygen concentration in the cylinder 32 to 0.1% or more and 10% or less, as shown in FIG. 2, a pipe (not shown) is provided near the supply port 40 of the extruder 22, and an inert gas is removed. It is preferable to supply in the cylinder 32 to make the inside of the cylinder 32 into an inert gas atmosphere. The oxygen concentration in the extruder 22 can be made 0.1% or more and 10% or less by flowing an inert gas in the range of 0.1 liter / min to 1 liter / min in the extruder 22. Here, in order to effectively bring the oxygen concentration in the cylinder 32 to 0.1% or more and 10% or less, it is preferable to introduce an inert gas into the cylinder 32 before the pellets introduce the main mixture into the extruder 22. In addition, it is preferable to install a filter (not shown) in the middle of the pipe (not shown) to remove the fine dust in the inert gas and then to flow into the extruder 22. By doing in this way, since it will not be oxidized in the cycloolefin resin which is easy to produce the oxidation by heat, the cycloolefin resin film suitable as a high functional film for optical use with few generation | occurrence | production of a foreign material can be provided. Here, if the flow rate of the inert gas is less than 0.1 liter / min, there is no effect of preventing the oxidation of the cellulose-based resin. If the flow rate of the inert gas is more than 1 liter / min, the oxidation prevention is lower than that of the case of 1 liter / min. The effect does not change. The inert gas is not particularly limited, but is easy to obtain, and inexpensive nitrogen gas can be preferably used.

Moreover, as another method of making oxygen concentration in the cylinder 32 into 0.1% or more and 10% or less, as shown in FIG. 2, it is considered to make a hopper into the vacuum hopper 44 '. The vacuum hopper 44 'is provided with a vacuum processing pipe 48, and the inside of the hopper and the extruder 22 by operating the vacuum pump 50 by closing the supply port 52 of the hopper with a cover (not shown). The oxygen concentration in the cylinder 32 can be lowered.

Inside the cylinder 32, the supply part (region shown by A) which carries out fixed quantity transportation of the cycloolefin resin supplied from the supply port 40 sequentially from the supply port 40 side, and the compression part which knead | mixes and compresses a cycloolefin resin. (Area shown by B) and the measurement part (area shown by C) which measures the kneaded and compressed cycloolefin resin.

The screw compression ratio of the extruder 22 is set to 2-5, and L / D is set to 20-50. Here, the screw compression ratio refers to the degree to which the molding material is compressed in a molten state in order to knead by applying back pressure, and the volume ratio (ie, volume per unit length of the supply portion A) of the supply portion A and the metering portion C Volume per unit length of the metering section C), the outer diameter d1 of the screw shaft 34 of the supply section A, the outer diameter d2 of the screw shaft 34 of the metering section C, and the supply section ( It is computed using the groove diameter a1 of A) and the groove diameter a2 of the measurement part C. In addition, L / D is ratio of the cylinder length L with respect to the cylinder internal diameter D of FIG. In addition, the temperature of the extruder 22 is set in the range of more than glass transition temperature (Tg) of a pellet (cycloolefin resin) (Tg + 40 degreeC) or less.

If the screw compression ratio is less than 2 and too small, it will not be sufficiently kneaded to generate undissolved portions or small shear heat generation, resulting in insufficient melting of crystals. On the contrary, if the screw compression ratio exceeds 5 and is too large, the shear stress is applied too much, resulting in deterioration of the resin or cleavage of molecules due to heat generation, resulting in lower molecular weight. Thereby, molten resin will become nonuniform and fluctuation of the discharge pressure of the extruder 22 will become large. Therefore, in order to reduce the fluctuations in the discharge pressure of the extruder 22 and to reduce the thickness nonuniformity of the film, the screw compression ratio is preferably in the range of 2 to 5, more preferably in the range of 2.5 to 4.5, particularly preferably 3 to 4 Range.

In addition, when L / D is less than 20 and too small, it will become insufficient melt | fusing and kneading | mixing, and it becomes easy to remain | fine grains similarly to the case where a compression ratio is small. On the contrary, when L / D exceeds 50 and is too big | large, the residence time of cycloolefin resin in the extruder 22 will become too long, and it will become easy to cause deterioration of resin. In addition, when the residence time becomes longer, the molecules are cleaved and the molecular weight decreases. Therefore, in order to reduce the fluctuations in the discharge pressure of the extruder 22 and reduce the thickness nonuniformity of the film, the range of L / D is preferably in the range of 20 to 50, preferably in the range of 25 to 45, particularly preferably 30 to 40. Range.

And the length of the compression part B of the extruder 22 shall be 1 / 5-2 / 3 compared with the length of the supply part A, and / or the length of the measurement part C. By doing so, decomposition | disassembly by the cellulose resin is compressed by the compression part B is prevented. That is, in particular, since the cellulose-based resin is easily decomposed by energy such as heat, the decomposition time can be prevented by reducing the compression time by regulating the length of the compression section of the extruder. Therefore, fine crystals are less likely to remain in the molten resin, and the cellulose resin is not decomposed, so that the molten resin becomes uniform. Here, if the length of the compression section B of the extruder 22 is in the range of 1/5 to 2/3 relative to the length of the supply section A and / or the length of the metering section C, it is shorter than 1/5. This is because the cellulose resin cannot be melted, and if it is longer than 2/3, the cellulose resin is decomposed.

Moreover, it makes it easy to melt pelletized cellulose resin by making the temperature of the supply part B of the extruder 22 into the range of 160-200 degreeC. When the temperature of the supply part A of the extruder 22 is less than 160 degreeC and too low, melting of a crystal will become inadequate and fine crystal | crystallization will remain in molten resin. On the contrary, if the temperature of the supply part A of the extruder 22 exceeds 200 degreeC and is too high, a cycloolefin resin will stick to the screw 38 part of supply part A, and the screw 38 of supply part A may be Since the resin adhering to the part becomes difficult to be transferred to the compression section B, it is deteriorated by heat. Therefore, as for extrusion temperature, 160 degreeC-200 degreeC is good, Preferably it is the range of 170 degreeC-190 degreeC, Especially preferably, it is the range of 175 degreeC-185 degreeC.

The cycloolefin resin is melted by the extruder 22 configured as described above, and the molten resin is continuously transferred from the discharge port 42 to the die 24 (see FIG. 1) by variation of discharge pressure within 10%. . Further, downstream of the extruder 22, it is preferable to provide a gear pump for discharge amount control and a foreign matter removal filter (not shown). In addition, it is possible to adjust the outlet pressure of the screw extruder to a desired value by adjusting the amount of the gear pump for discharge amount control.

The molten resin transferred to the die 24 by the extruder 22 is extruded from the die 24 into a sheet form, cast on the cooling drum 26, and solidified by cooling to form a resin film 12. In addition, in order to prevent thermal degradation and coloring, the molten polymer temperature at the time of being extruded from the die 24 is preferably Tg + 100 ° C or higher and Tg + 130 ° C or lower. Moreover, it is preferable that the die | dye 24 is formed in the range of the perpendicular | vertical direction and the direction inclined at 45 degrees in the rotation direction of the cooling drum 26. As shown in FIG.

As described above, the cycloolefin-based resin film 12 formed by the film forming step 14 has a circular equivalent diameter of 0.7 or more and a gel having a diameter of 0.5 µm or more and 3 µm or less at a density of 50 to 2000 pieces / mm 2. It is possible to make a cycloolefin-based resin film having a density of 10 particles / mm 2 or less in a gel having a circular equivalent diameter of 10 μm or more having a circularity of 0.7 or more.

Conventionally, when cooling a molten resin on a cooling drum, addition of an additive may also cause the molten resin to slip on a cooling drum, and there existed a problem that the optical physical property of the cycloolefin resin film formed into a film became uneven. .

In the cycloolefin-based resin film formed by the melt film forming method, a circular equivalent diameter having a circularity of 0.7 or more and containing 50 to 2000 gels / mm 2 having a size of 0.5 µm or more and 3 µm or less, and a circular equivalent diameter of 0.7 or more By setting the gel of 10 micrometers or more to 10 pieces / mm <2> or less, the fall of the optical characteristic by the generation | occurrence | production of a gel can be suppressed, and the outstanding handling titration can be provided without mix | blending a slip material. That is, the cycloolefin-based resin film formed into a film contains a circular equivalent diameter of 0.7 or more and a circle size of 0.5 µm or more and 3 µm or less in 50 to 2000 pieces / mm 2 and a circular equivalent diameter of 0.7 or more. When the gel having a size of 10 μm or more is 10 pieces / mm 2 or less, the gel expressed by melting in the extruder does not interfere with the optical properties, and excellent handling titration can be given without blending the slip material. The cycloolefin resin film of can be provided. Further, the gel having a circular equivalent diameter of 0.5 or more and 0.5 µm or more and 3 µm or less preferably has a density of 50 to 1000 pieces / mm 2 and more preferably 100 to 500 pieces / mm 2.

In addition, in the present invention, the size of the gel is dissolved in cyclohexane at 25 ° C. to adjust a 10 wt% solution, and using a Seishin kine particle size and shape distribution measuring instrument (type PITA-1) in 4 ml of the adjusting solution. CCD camera image photographing of all gels contained is performed to obtain a circle equivalent diameter and circularity. The circle equivalent diameter measures the area of the particle from the image data, and assumes a circle having the same area as the particle to obtain the diameter of the circle. In addition, the circularity assumes a circle equal to the area of the particle, and is the value obtained by dividing the circumferential length of the circle by the length around the particle. The closer to 1.0, the closer to the epicenter.

The cycloolefin resin film 12 formed into a film by the film forming process part 14 is extended | stretched by the longitudinal stretch process part 16 and the lateral stretch process part 18. As shown in FIG.

Below, the extending process until it extends | stretches the cycloolefin resin film 12 formed into a film by the film forming process part 14, and manufactures the extending | stretching cycloolefin resin film 12 is demonstrated.

Stretching of the cycloolefin resin film 12 is performed in order to orient the molecules in the cycloolefin resin film 12 to express in-plane retardation Re and retardation Rth in the thickness direction. In addition, when the cycloolefin resin film 12 is used without expressing Re and Rth, it is wound up by the winding process part 20 of FIG. 1 in roll shape, without passing through an extending process.

As shown in FIG. 1, the cycloolefin resin film 12 is first longitudinally stretched in the longitudinal direction by the longitudinal stretching step 16. After the cycloolefin resin film 12 is preheated in the longitudinal stretching step 16, the cycloolefin resin film 12 is wound around two nip rolls 28 and 30 in a heated state. The nip roll 30 on the outlet side conveys the cycloolefin resin film 12 at a higher conveying speed than the nip roll 28 on the inlet side, whereby the cycloolefin resin film 12 is stretched in the longitudinal direction. .

As for the preheating temperature in the longitudinal stretch process part 16, Tg-40 degreeC or more and Tg + 60 degreeC or less are preferable, Tg-20 degreeC or more and Tg + 40 degreeC or less are more preferable, Tg or more and Tg + 30 It is more preferable that the temperature is lower than or equal to. Moreover, as for extending | stretching temperature of the longitudinal stretch process part 16, Tg or more and Tg + 60 degreeC or less are preferable, Tg + 2 degreeC or more and Tg + 40 degreeC or less are more preferable, Tg + 5 degreeC or more and Tg + 30 It is more preferable that the temperature is lower than or equal to. 1.0 times or more and 2.5 times or less are preferable, and, as for the draw ratio of a longitudinal direction, 1.1 times or more and 2 times or less are more preferable.

The longitudinally stretched cycloolefin resin film 12 is transferred to the transverse stretching step 18 and transversely stretched in the width direction. In the lateral stretch process part 18, a tenter can be used preferably, for example, The both sides of the width direction of the cycloolefin resin film 12 are gripped with a clip, and it extends in a lateral direction by this tenter. By this lateral stretching, the retardation (Rth) can be further increased.

It is preferable to perform lateral stretch using a tenter, and preferable extending | stretching temperature is preferably Tg or more and Tg + 60 degreeC or less, More preferably, Tg + 2 degreeC or more and Tg + 40 degreeC or less, More preferably, Tg It is +4 degreeC or more and Tg + 30 degreeC or less. 1.0 times or more and 2.5 times or less are preferable, and, as for a draw ratio, 1.1 times or more and 2.0 times or less are more preferable. It is also preferable to relax to either or both of the length and width and the width after lateral stretching. Thereby, distribution of the slow axis of the width direction can be made small.

By such stretching, Re is 0 nm or more and 500 nm or less, More preferably, 10 nm or more and 400 nm or less, More preferably, 15 nm or more and 300 nm or less, Rth is 0 nm or more and 500 nm or less, More preferably, 50 It is nm or more and 400 nm or less, More preferably, they are 70 nm or more and 350 nm or less.

It is more preferable to satisfy Re <= Rth among these, More preferably, it is more preferable to satisfy Re * 2 <= Rth. In order to realize such a high Rth and a low Re, it is preferable to extend | stretch the longitudinal stretched to the lateral (width) direction as mentioned above. That is, the difference between the longitudinal direction and the transverse direction becomes the difference (Re) of the in-plane retardation, but in addition to the longitudinal direction, the difference in the longitudinal and transverse orientations is also reduced by stretching in the transverse direction, which is the orthogonal direction, to reduce the surface orientation (Re). Can be made small. On the other hand, since the area magnification increases by stretching in the horizontal direction in addition to the length, the orientation in the thickness direction increases with the decrease in the thickness, so that Rth can be increased.

Moreover, it is preferable to make all the fluctuation | variation according to the place of the width direction and the longitudinal direction of Re and Rth to 5% or less, More preferably, it is 4% or less, More preferably, it is 3% or less.

The cycloolefin resin film 12 after extending | stretching is wound up in roll shape by the winding process part 20 of FIG. In that case, it is preferable to make the winding tension of the cycloolefin resin film 12 into 0.02 kg / mm <2> or less. By setting the winding tension in such a range, the stretched cycloolefin-based resin film 12 can be wound up without generating a retardation distribution. Moreover, it is preferable that the thickness of the cycloolefin resin film 12 is 20-300 micrometers.

(Material of the optical film)

<Cycloolefin resin>

As a raw material of the cycloolefin resin film of the present invention, cycloolefin resin is used. Especially, the cyclic olefin superposed | polymerized by a cycloolefin type compound is preferable. Although this polymerization can be performed by any of ring-opening polymerization and addition polymerization, it is more preferable that it is addition polymerization among cyclic olefin.

Examples of addition polymerization include those of Japanese Patent 3517471, Japanese Patent 3559360, Japanese Patent 3867178, Japanese Patent 3871721, Japanese Patent 3907908, Japanese Patent 3945598, Japanese Patent Publication 2005-527696, Japanese Patent Publication 2006-28993, WO 2006-004376 The thing described in is mentioned. Particularly preferred are those described in Japanese Patent 3517471.

Examples of the ring-opening polymerization include those described in WO 98-14499, Japanese Patent 3060532, Japanese Patent 3220478, Japanese Patent 3273046, Japanese Patent 3404027, Japanese Patent 3428176, Japanese Patent 3687231, Japanese Patent 3873934, and Japanese Patent 3912159. Among them, preferred ones are those described in WO 98-14499 and Japanese Patent 3060532.

Pelletization is usually pelletized using a pelletizer of a cold cutting method after removing the solvent after polymerization, but again processed into a melt-strand using a vacuum-treated biaxial kneading apparatus, followed by extrusion processing. It is no problem to do it. In particular, the pellet shape is prevented by using a hot cut pelletizer (device name PPH manufactured by Toshiba Kikai) or an underwater type pelletizer (apparatus name PPW manufactured by Toshiba Kikai) to form an angled annular shape without a large gel of 10 µm or more. Effective for

<Additive>

0-20 mass% of alkylphthalyl alkyl glycolates, phosphate ester, carboxylic acid ester, and polyhydric alcohol can be added to these cycloolefin resin films as a plasticizer. Phosphite-based stabilizers (e.g., tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) force as stabilizers Pits), phenolic stabilizers (e.g., 2,6-di-t-butyl-4-methylphenol, 2,2-methylenebis (4-ethyl-6-t-butylphenol), 2,5-di -t-butylhydroquinone, pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propioate, 4,4-thiobis- (6-t-butyl-3 -Methylphenol), 1,1-bis (4-hydroxyphenyl) cyclohexane, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propiolate], epoxy compound, 0-3 mass% of a thioether compound can be added 0-1000 ppm of inorganic fine particles, such as a silica, titania, zirconia, alumina, calcium carbonate, and clay, organic fine particles, such as crosslinked acrylic and crosslinked styrene, can be added as a mat agent. UV absorbers (e.g., 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6-[(2H-benzotriazol-2-yl) phenol ]]) And an infrared absorber and a retardation regulator are also preferable.

(Film forming of cycloolefin resin film)

<Melt film forming method>

A) pelletization

Although it is preferable to apply the said resin and additive to the resin surface prior to melt film forming, it may pelletize.

Pelletizing can be produced by drying the resin and the additive and then melting at 150 ° C to 300 ° C using a twin-screw kneading extruder, and then solidifying and extruding the extruded into a noodle shape in the air or in water. Moreover, you may pelletize by the underwater cutting method etc. which cut while extruding directly from a mold in water after melting with an extruder.

As for the rotation speed of an extruder, 10 rpm-1000 rpm are preferable, More preferably, they are 20 rpm-700 rpm. The extrusion residence time is 10 seconds or more and less than 10 minutes, More preferably, it is 20 seconds-5 minutes or less.

As for the size of a preferable pellet, 10 micrometers-1000 micrometers are preferable, More preferably, they are 30 micrometers-500 micrometers.

B) kneading and melting

It is desirable to reduce the moisture in the pellets prior to melt film formation. Preferable drying temperature is 40-200 degreeC, More preferably, it is 60-150 degreeC. Thereby, it is preferable that water content is 1.0 mass% or less, and it is more preferable that it is 0.1 mass% or less. Drying may be performed in air, may be performed in nitrogen, and may be performed in a vacuum.

The dried pellets are fed into the cylinder through the feed port of the extruder, kneaded and melted. The inside of a cylinder is comprised by a supply part (area A), a compression part (area B), and a metering part (area C) sequentially from the supply port side. As for the screw compression ratio of an extruder, 1.5-4.5 are preferable, As for ratio L / D of the cylinder length with respect to a cylinder internal diameter, 20-70 are preferable, and the cylinder internal diameter has preferable 30 mm-150 mm. Here, the screw compression ratio refers to the degree to which the molding material is compressed in the molten state in order to knead by applying back pressure, and the volume ratio of the supply part A and the metering part C (that is, the capacity per unit length of the supply part A ÷ Volume per unit length of the metering section C), the outer diameter d1 of the screw shaft 34 of the supply section A, the outer diameter d2 of the screw shaft 34 of the metering section C, and the supply section ( It is computed using the groove diameter a1 of A) and the groove diameter a2 of the measurement part C. In addition, L / D is ratio of the cylinder length L with respect to the cylinder internal diameter D of FIG. As for extrusion temperature, 190-300 degreeC is preferable. When the temperature in the extruder 22 exceeds 230 degreeC, a cooler (not shown) may be provided between the extruder 22 and the die 24. Moreover, in order to prevent the molten resin by oxidation remaining and the gel generate | occur | producing, it is also preferable to carry out the inside of an extruder while evacuating in an inert (nitrogen etc.) airflow or using an extruder with a vent.

C) filtration

In order to filter foreign substances, such as a gel in molten resin, it is preferable to provide the filtration apparatus equipped with the breaker plate type filtration and a leaf-type disc filter. Filtration may be performed in one stage, and multistage filtration may be sufficient. As for filtration precision, 15 micrometers-3 micrometers are preferable, More preferably, they are 10 micrometers-3 micrometers. It is preferable to use stainless steel as the filter medium. The structure of a filter medium can use the thing which knitted the wire rod, the thing which sintered the metal fiber, or the metal powder (sintered filter medium), and especially a sintered filter medium is preferable.

D) gear pump

It is preferable to install a gear pump between the extruder and the die in order to reduce the variation in the discharge amount and to improve the thickness accuracy. Thereby, the fluctuation range of the resin pressure in die | dye can be within +/- 1%.

In order to improve the quantitative feeding performance by the gear pump, a method of controlling the pressure before the gear pump by changing the rotational speed of the screw can also be used.

ㅁ) Die

It melts by the extruder comprised as mentioned above, and a molten resin is continuously conveyed to a die via a filter and a gear pump as needed. The die may be any type of T die, fishtail die, or hanger coat die. It is also preferable to put a static mixer in front of the die in order to improve the uniformity of the resin temperature. The clearance of the T die exit portion is generally preferably 1.0 to 10 times the film thickness, and preferably 1.2 to 5 times.

It is preferable that a die is thickness-adjustable at 5-50 mm intervals. Moreover, the automatic thickness adjustment die which calculates downstream film thickness and thickness deviation, and feeds the result back to the thickness adjustment of a die is also effective. In addition to a single layer film forming apparatus, it can also manufacture using a multilayer film forming apparatus.

In this way, 1 minute-40 minutes are preferable, and, as for the residence time from when a resin enters an extruder from a supply port and comes out of a die, 2 minutes-10 minutes are more preferable.

ㅂ) Cast

The molten resin (melt) extruded from the die onto the sheet is cooled and solidified on a casting drum to obtain a film. At this time, it is preferable to shield between the die and the casting drum to suppress the influence of the wind.

When the melt is in contact with the casting drum, it is preferable to increase the adhesion between the casting drum and the melt using an electrostatic application method, an air knife method, an air chamber method, a vacuum nozzle method, a touch roll method, and the like. The roll method is preferable. This adhesion improvement method may be performed to the whole surface of a melt, and you may carry out to a part.

The touch roll method forms a film surface by placing a touch roll on a cast drum. Under the present circumstances, it is preferable that a touch roll is not high normal rigidity but has elasticity. Thereby, it can suppress that surface unevenness falls below the range of this invention by excessive surface pressure. For this purpose, it is necessary to make thickness of the outer cylinder of a roll thinner than a normal roll, and, as for the thickness Z of an outer cylinder, 0.05 mm-7.0 mm are preferable, More preferably, it is 0.2 mm-5.0 mm, More preferably, 0.3 mm- 3.5 mm. The touch roll may be provided on the metal shaft to pass a fruit (fluid) therebetween, an elastic layer is formed between the outer cylinder and the metal shaft, and the fruit (fluid) is filled between the outer cylinder. The weaker the adhesion by the touch roll, the better the Rth can be reduced. However, if too small, the surface roughness of the present invention cannot be achieved. On the other hand, if the surface is too large, the surface roughness is small but Rth is likely to increase. Therefore, the surface pressure of the touch roll is preferably 0.1 MPa to 5 MPa, more preferably 0.2 MPa to 3 MPa, still more preferably 0.3 MPa to 2 MPa. The surface pressure here is the value which divided | divided the force which contact | contacts a touch roll by the contact area of a cycloolefin resin film and a touch roll.

The temperature of the touch roll is preferably set to 60 ° C to 160 ° C, more preferably 70 ° C to 150 ° C, and even more preferably 80 ° C to 140 ° C. Such temperature control can be achieved by passing a temperature-controlled liquid or gas into these rolls. Thus, it is more preferable to have a temperature control mechanism inside.

It is preferable that the material of a touch roll is a metal, More preferably, it is stainless and it is also preferable to plate on the surface. On the other hand, in the rubber roll or the metal roll lined with rubber, unevenness | corrugation of the rubber surface is too big | large, and since the cycloolefin resin film which has the said surface unevenness cannot be formed into a film, it is unpreferable.

Arithmetic mean height Ra is 100 nm or less, Preferably it is 50 nm or less, More preferably, the surface of a touch roll and a casting roll is 25 nm or less. The touch roll is, for example, Japanese Patent Laid-Open No. 11-314263, Japanese Patent Laid-Open No. 2002-36332, Japanese Patent Laid-Open No. 11-235747, International Publication No. 97/28950 Pamphlet, Japanese Patent Laid-Open No. 2004- 216717 and Unexamined-Japanese-Patent No. 2003-145609 can be used.

More preferably, a plurality of casting drums (rolls) are used to cool them. (The above-described use of the touch rolls is arranged to touch the first casting rolls on the most upstream side (near the die).) In general, using three cooling rolls is relatively well performed, but this is not the case. 100 mm-1500 mm are preferable, and, as for the diameter of a roll, 150 mm-1000 mm are more preferable. As for the space | interval of several predetermined roll, 0.3 mm-300 mm are preferable between surfaces, More preferably, they are 1 mm-100 mm, More preferably, they are 3 mm-30 mm. As for the casting drum, 60 degreeC-160 degreeC is preferable, More preferably, it is 70 degreeC-150 degreeC, More preferably, it is 80 degreeC-140 degreeC.

Thereafter, it is peeled off the casting drum, and after winding through a nip roll. The winding speed is preferably 10 m / min to 100 m / min, more preferably 15 m / min to 80 m / min, still more preferably 20 m / min to 70 m / min.

0.7m-3m are preferable and, as for a film forming width, 1m-2m are more preferable. 30 micrometers-300 micrometers are preferable, as for the thickness after film forming (unstretched), More preferably, they are 40 micrometers-250 micrometers, More preferably, they are 60 micrometers-200 micrometers.

S) trimming, thickness forming processing, winding

It is also preferable to trim both ends, after extending | stretching film forming in this way. The part cut out by trimming may be crushed and used again as a raw material.

Moreover, it is also preferable to perform thickness formation process (knurling process) at one end or both ends. 1 micrometer-50 micrometers are preferable, and, as for the height of the unevenness | corrugation by thickness formation process, More preferably, they are 3 micrometers-20 micrometers. Thickness formation process may be made to make both surfaces convex, or may make one side convex. 1 mm-50 mm are preferable, and, as for the width | variety of thickness formation process, 3 mm-30 mm are more preferable. Extrusion process can be performed at room temperature-300 degreeC.

It is also preferable to attach a laminate film on one side or both sides before winding up. 5 micrometers-100 micrometers are preferable, and, as for the thickness of a laminate film, 10 micrometers-50 micrometers are more preferable. The material is not particularly limited, such as polyethylene, polyester and polypropylene. Preferable winding tension is 2 kg / m width-50 kg / width, More preferably, it is 5 kg / m width-30 kg / width.

(Extension)

It is preferable to perform longitudinal stretch and lateral stretch of the resin film which carried out film forming, and may further combine a shrinkage process. Among them, preferred is to perform transverse stretching after longitudinal stretching or to combine transverse stretching and longitudinal contraction treatment, the former being suitable for expressing high Rth, and the � is suitable for expressing low Rth. When performing a combination of transverse stretching and longitudinal contraction treatment, longitudinal contraction may be performed during transverse stretching, after transverse stretching, or both. Moreover, you may combine longitudinal stretch before or after this lateral stretch, or both.

[Long stretch]

Longitudinal stretching may be performed independently, and you may carry out in combination with lateral stretching. Although longitudinal stretch may be performed before and after lateral stretch, it is more preferable to carry out before lateral stretch. In addition, longitudinal stretch may be performed in 1 step | paragraph, and may be divided and implemented in multiple steps.

Longitudinal stretching can be achieved by providing two pairs of nip rolls, making the circumferential speed of the nip roll on the outlet side faster than the circumferential speed of the nip roll on the inlet side while heating therebetween. At this time, the reproducibility of retardation in the thickness direction can be changed by changing the space | interval L between nip rolls, and the film width W before extending | stretching. If L / W exceeds 2 and 50 or less (long span stretching), Rth can be made small, and when L / W is 0.01 or more and 0.3 or less (short span stretching), Rth can be made large. In the present invention, any of long span stretching, short span stretching, and an area therebetween (middle stretching = L / W exceeds 0.3 and 2 or less) may be used, but long span stretching and short span stretching can reduce the orientation angle. This is preferred. Moreover, when aiming at high Rth, it is more preferable to use it by short-span stretching and to distinguish it from long-span stretching when aiming at low Rth.

The preferred stretching temperature of these longitudinal stretching is (Tg-10 ° C) to (Tg + 50) ° C, more preferably (Tg-5 ° C) to (Tg + 40) ° C, still more preferably (Tg) to (Tg + 30) ° C. Preferable draw ratio is 2%-200%, More preferably, they are 4% or more and 150% or less, More preferably, they are 6%-100%.

<< long span extension >>

The film is stretched by stretching, but the film is reduced in thickness and width in order to reduce the volume change. When the nip roll interval is increased, the shrinkage in the width direction tends to be reduced, and the decrease in thickness can be suppressed (the compression in the thickness direction is small), the molecular orientation in the film plane can be suppressed, and the Rth can be made small.

L / W exceeds 2 and 50 or less are preferable, More preferably, it is 3-40, More preferably, it is 4-20. Such long span stretching may be performed in multiple stages by three or more pairs of nip rolls, and the longest aspect ratio among the multiple stages may be in the above range.

Such long span stretching may be performed by heating and stretching a film between two pairs of nip rolls separated by a predetermined distance, and the heating method is a heater heating method (infrared heater, halogen heater, panel heater, or the like installed on or under the film and heated by radiant heat). It may be sufficient, or the zone heating method (heating in the zone which temperature-controlled to predetermined temperature by taking in hot air etc.) may be sufficient.

<< sweet span extension >>

L / W exceeds 0.01 and is less than 0.3, More preferably, it carries out longitudinal stretch (span stretch) to 0.03-0.25, More preferably, it is 0.05-0.2. This makes it possible to reduce the neck-in (shrinkage in the direction parallel to the stretching due to the stretching) and to easily reduce the thickness. As a result, it is compressed in the thickness direction, the orientation (surface orientation) of the thickness direction advances, and Rth tends to increase.

Short-span stretching can be performed by changing the conveyance speed between two or more pairs of nip rolls, but as shown in the normal roll arrangement (the longitudinal stretching step 108 of FIG. 3 of JP 2007-152558 A), the nip rolls are parallel to each other. It is possible to achieve this by arranging two pairs of nip rolls at an angle (displacement of the axis of rotation of the front and rear nip rolls up and down), unlike a gap between the arrangement and the rolls, thereby making the L / W small. As shown to the longitudinal drawing process part 20 of FIG. 1 of 51804, the nip roll is displaced up and down and arrange | positioned. However, in this drawing, although the nip rolls 22 and 24 are drawn widely, L / W can be made small by narrowing this space | interval and making nip rolls approach. Thereby, since a heating heater cannot be installed between nip rolls, it is preferable to flow a fruit in a nip roll and to heat up a film. Moreover, it is also preferable to install the preheat roll which flowed the inside inside in front of the inlet side nip roll, and to heat a film before extending | stretching.

[Lateral stretching]

Lateral stretching can be performed using a tenter. That is, it extends | stretches by holding | gripping both ends of the width direction of a film with a clip, and extending a width in a horizontal direction. At this time, extending | stretching temperature can be controlled by sending the wind of a desired temperature in a tenter. As for extending | stretching temperature, Tg-10 degreeC or more and Tg + 60 degrees C or less are preferable, Tg-5 degreeC or more and Tg + 45 degrees C or less are more preferable, Tg or more and Tg + 30 degrees C or less are more preferable. Preferable draw ratio is 10% or more and 250% or less, More preferably, they are 20% or more and 200% or less, More preferably, they are 30% or more and 150% or less. The draw ratio here is defined by the following formula.

Stretch ratio (%) = 100 × {(length after stretching)-(length before stretching)} / (length before stretching)

By preheating before such stretching and post-heating treatment after stretching, the Re and Rth distributions after stretching can be reduced to reduce the deviation of the orientation angle due to bowing. Although preheating and postheating may be either, it is more preferable to perform both. It is preferable to carry out these preheating and postheating processes by holding | gripping with a clip, ie, it is preferable to carry out continuously after extending | stretching.

The post-heat treatment is preferably 1 ° C or more and 50 ° C or less, more preferably 2 ° C or more and 40 ° C or less, and more preferably 3 ° C or more and 30 ° C or less than the stretching temperature. More preferably, it is below extending | stretching temperature, and it is preferable to set it as Tg or less. Preferable preheating time is 1 second or more and 10 minutes or less, More preferably, they are 5 second or more and 4 minutes or less, More preferably, they are 10 second or more and 2 minutes or less. At the time of heat setting, it is preferable to keep the width of the tenter almost constant. Here, "almost" refers to 0% (the same width | variety as the tenter width after extending | stretching) --10% (shrinkage width = 10% reduction | stretching width than the tenter width after extending | stretching) of the tenter width after completion | finish of extending | stretching. It is not preferable to increase the width beyond the stretching width because residual strain tends to occur in the film.

Preheating is extending | stretching temperature ± 50 degreeC, More preferably, extending | stretching temperature ± 35 degreeC, More preferably, extending | stretching temperature ± 20 degreeC. When the bowing after the post-heat treatment is convex in the advancing direction, it is preferable to lower it than the stretching temperature, and when it is concave in the advancing direction, it is preferable to make it higher than the stretching temperature. Preferable preheating time is 1 second or more and 10 minutes or less, More preferably, they are 5 second or more and 4 minutes or less, More preferably, they are 10 second or more and 2 minutes or less. During preheating, it is desirable to keep the width of the tenter almost constant. "Almost" refers to +/- 10% of the width of an unstretched film here. Thus, it is more preferable that it is heat setting temperature <extending | stretching temperature <preheating temperature.

By such stretching, the deviation from the width direction of Re, Rth, the deviation of a longitudinal direction, MD (length direction) or TD (width direction) of an orientation angle can be made small.

[Shrink processing]

Shrinkage treatment is preferably performed during or after stretching, and more preferably, shrinkage relaxation treatment in the longitudinal (length) direction during transverse stretching or after transverse stretching. Shrinkage processing can be achieved by making the conveyance speed of a longitudinal direction lower than a upstream side, The shrinkage amount is 0.1% or more and 50% or more, More preferably, they are 1% or more and 40% or less, More preferably, 5 More than 35%. The amount of shrinkage here is represented by the following formula.

Shrinkage (%) = 100 × {(length before shrinkage treatment)-(length after shrinkage treatment)} / (length before shrinkage treatment)

The shrinkage treatment temperature is (Tg-20) ° C to (Tg + 50) ° C, more preferably (Tg-10) ° C to (Tg + 40) ° C, still more preferably Tg to (Tg + 30) ° C. The shrinkage treatment time is 1 second or more and 15 minutes or less, more preferably 5 seconds or more and 10 minutes or less, still more preferably 10 seconds or more and 5 minutes or less.

Stretching extends in the stretching direction, but the stretching, the orthogonal direction, and the thickness direction are reduced in order to match the material resin accordingly. As the thickness decreases, the film plane is compressed, molecules are oriented in the plane, and the plane orientation becomes strong. As a result, Rth increases. However, by performing longitudinal shrinkage, thickness reduction can be suppressed and low Rth can be realized. In other words, by longitudinal contraction, Rth <Re × 1.5, more preferably Rth <Re can be realized. Moreover, this longitudinal contraction also has the effect of suppressing thermal contraction of the film after stretching, and the amount of thermal contraction at 80 ° C and 100hr can be made 0.5% or less, more preferably 0.3% or less.

Such longitudinal shrinkage can be achieved, for example, by the following method.

Shrinkage treatment in stretching

Longitudinal shrinkage in transverse stretching can be achieved by extending | stretching in the width direction, slowing the conveyance speed of the clip in a tenter from the inlet side to the outlet side, For example, it can carry out using a biaxial stretching machine, specifically, transverse Stretching and longitudinal shrinkage can be performed simultaneously. For example, Japanese Patent Laid-Open No. 2003-211533, Japanese Patent Laid-Open No. 6-210726, Japanese Patent Laid-Open No. 6-278204, Japanese Patent Laid-Open No. 11-77825, Japanese Patent Laid-Open No. 2000-246795, Japanese Patent Laid-Open No. 2004-106434, Japan The apparatus described in patent publication 2004-195712, Japanese patent publication 2006-142595, Japanese patent publication 2006-22916, etc. can be used. Specifically, a high function thin film device (trade name FITZ) manufactured by Ichinko Co., Ltd. can be used. The apparatus can arbitrarily set the draw ratio in the longitudinal direction (length direction of the film = the advancing direction of the film) and the draw ratio in the transverse direction (width direction = the direction perpendicular to the advancing direction of the film), and also in the longitudinal direction (length direction). Since the shrinkage ratio of can be arbitrarily set, the stretching and shrinkage can be simultaneously performed under predetermined conditions. For example, by appropriately combining a generally known rail width control method, a pantograph method, a method of controlling the traveling speed by a linear motor, etc., the draw ratio of the width direction is controlled, and the film edge is clamped. It is also possible to use a biaxial stretching machine for controlling the length in the longitudinal direction by changing the interval of one clip.

<< shrink processing after the stretching >>

The following methods of I), II), III) and IV) can be exemplified but preferred methods are II) and IV).

I) During or after transverse stretching (tenter stretching), the conveyance speed of the clip in a tenter is made slower than the conveyance speed of the clip of an extending | stretching part entrance.

Lateral stretching is performed by widening the width of both ends of the film by the clip (tenter stretching), but in order to promote contraction in the direction perpendicular to the stretching and to promote thickness shrinkage, the conveying speed of the clip in the tenter during or after the stretching is promoted. Slower than the extension opening.

Among these, more preferably, longitudinal shrinkage is performed after lateral stretching (when lateral stretching and longitudinal contraction are performed simultaneously, stretching and elongation occur simultaneously in the plane, and residual strain is likely to occur, and in-plane uniformity tends to decrease). The longitudinal contraction after such transverse stretching can be achieved, for example, by transversal stretching and longitudinal contraction by preparing another tenter rail so that the speed can be independently controlled, and Japanese Unexamined Patent Publication No. Hei 6-210726 and Japanese Unexamined Patent Publication. It can be realized by shrinking in the longitudinal direction (transfer direction) using those as described in JP-A-6-278204, JP-A-11-77825, JP-A-2004-195712 and JP-A-2006-142595. Can be.

II) After transverse stretching by a tenter, it heat-processes, making the conveyance speed of an exit side slower than the inlet side of a heat treatment zone.

In this method, after transverse stretching (after exiting a tenter), a film can be inserted in the heat processing zone provided with two or more pairs of nip rolls, and it can achieve by making the conveyance speed of the nip roll of an entrance side faster than the nip roll of an exit side. In this longitudinal shrinkage zone, shrinkage of the film occurs in both the vertical and horizontal directions, so that the longitudinal shrinkage is expressed preferentially, the aspect ratio (the value of the zone length divided by the inlet film width) of the heat treatment zone is preferably 0.01 to 2, More preferably, it is 0.05-1.6, More preferably, it is 0.1-1.3. The heating method of the heat treatment zone may be performed by providing a heat treatment zone or a heater between the nip rolls, or may heat the nip roll to heat the resin film. The longitudinal shrinkage which lowers the conveyance speed on the outlet side is completely different from the heat treatment in which only the conveyance tension is weakened. That is, the effect of accelerating the neck in as described above does not occur at all by lowering the conveyance tension.

III) The resin film is shrunk in the conveying direction on the chuck of the tenter.

It can shrink | contract longitudinally by slipping a resin film in a conveyance direction on a chuck during lateral stretch or after lateral stretch. In other words, longitudinal shrinkage can be achieved by allowing the chuck to slide in the conveyance (vertical) direction. Although it does not specifically limit as such a method, For example, it can achieve by providing a pulley in the conveyance direction to the clip part of a chuck, and also an active material (for example, Teflon (trademark)) on the resin film holding surface of a clip. May be attached.

IV) Low tension conveyance between rolls after transverse stretching

After lateral stretching (after tenter), when the film is heat treated with storage force, it tries to shrink in both the longitudinal and horizontal directions, but at this time, the film is conveyed between the rolls to suppress the shrinkage in the lateral direction by the frictional force between the roll and the film. It can express first.

In order to obtain the frictional force necessary to suppress the lateral shrinkage of the film, the ratio (W / G) of the length (W) that the film wraps on the roll and the length (G) that the film does not contact the roll between the rolls is 0.01 or more and 3 or less are preferable, More preferably, they are 0.03 or more and 1 or less, More preferably, they are 0.05 or more and 0.5 or less. If this range is exceeded, friction between rolls will become long, TD shrinkage will generate | occur | produce, Re will fall, Rth / Re will rise easily, and a vertical wrinkle will be easy to express, and it is unpreferable. On the other hand, if W / G is less than this range, residual strain caused by stretching is not solved, and thermal dimension change is increased, which is not preferable.

The number of rolls is preferably 2 or more and 100 or less, more preferably 3 or more and 50 or less, still more preferably 4 or more and 20 or less. As for the diameter of a preferable roll, 5 cm or more and 100 cm or less are preferable, More preferably, they are 10 cm or more and 80 cm or less, More preferably, they are 15 cm or more and 60 cm or less.

Moreover, in order to fully acquire the frictional force between a roll and a resin film, the surface roughness Ra of a resin film has preferable 0.005 micrometer or more and 0.04 micrometer or less, More preferably, it is 0.007 micrometer or more and 0.035 micrometer or less, More preferably, it is 0.009 micrometer or more. It is 0.030 micrometer or less. The film having such a surface can be achieved by a touch roll film forming method. This can achieve high smoothness compared with the case where this film is not used by inserting the film immediately after casting by the roll with the smooth surface from both surfaces, and can implement the surface roughness mentioned above.

The longitudinal contraction treatment of I) and II) may be performed alone or in combination. The shrinkage treatment of II) may be performed online after the lateral stretching, or may be carried out offline after winding up after the stretching. Preferred is online processing.

[Volatile Components in Stretching]

It is preferable that volatile components (solvent, moisture, etc.) are 0.5 wt% or less with respect to resin, and, as for the said longitudinal stretch and the lateral stretch, More preferably, it is 0.3 wt% or less, More preferably, it is 0 wt%. This is because when the volatile component is present, the shrinkage stress caused by drying acts to make the bowing more remarkable.

[Film Properties after Stretching and Shrink Treatment]

In this way, it is preferable that the film Re and Rth after extending | stretching and shrinkage | contraction processing satisfy | fill the following formula (R-1) and (R-2).

Formula (R-1): 0 nm ≤ Re ≤ 300 nm

Formula (R-2): 10 nm ≤ Rth ≤ 300 nm

More preferably, the following formulas (R-3) and (R-4) are satisfied.

Formula (R-3): 20 nm ≤ Re ≤ 200 nm

Formula (R-4): 20 nm ≤ Rth ≤ 200 nm

In this specification, Re ((lambda)) and Rth ((lambda)) represent the in-plane retardation in the wavelength (lambda), and the retardation of the thickness direction, respectively. Re (λ) is measured by injecting light having a wavelength of λ nm in the direction of the film normal in KOBRA 21ADH or WR (Ojikei Sokukiki Co., Ltd.). In the selection of the measurement wavelength λ nm, a wavelength selection filter is used. It can be measured by replacing it with a manual or a program.

When the film to be measured is represented by the uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method. Rth (λ) makes Re (λ) the in-plane slow axis (determined by KOBRA 21ADH or WR) as the inclination axis (rotation axis) (if there is no ground axis, any direction in the film plane is the rotation axis). ) A total of six points were measured by injecting light having a wavelength of λ nm from the inclined direction in 10 degree steps from the normal direction to 50 degrees on the one side of the film normal direction, and measuring all 6 points of the measured retardation value and the average refractive index. KOBRA 21ADH or WR is calculated based on the input film thickness value.

In the above-described film having a direction in which the retardation value becomes zero at a predetermined inclination angle with the in-plane slow axis as the rotation axis from the normal direction, the retardation value at an inclination angle greater than the inclination angle is negative. After the change, KOBRA 21ADH or WR is calculated. In addition, a slow axis is used as an inclination axis (rotation axis) (when there is no ground axis, any direction in the film plane is a rotation axis), and the retardation value is measured from two inclined directions, and the value and the average refractive index Rth may be calculated from the following equations (3) and (4) based on the hypothetical value and the input film thickness value.

In addition, said Re ((theta)) shows the retardation value in the direction which inclined angle (theta) from a normal line direction. Nx in Formula (3) represents the refractive index of the slow-axis direction in surface inside, ny represents the refractive index of the direction orthogonal to nx in surface, and nz represents the refractive index of the direction orthogonal to nx and ny.

Rth = ((nx + ny) / 2-nz) × d-equation (4)

In the case where the film to be measured cannot be expressed by a single-axis or biaxial refractive index ellipsoid, and a film without an so-called optical axis, Rth (λ) can be calculated by the following method. Rth (λ) is a 10-degree step from -50 degrees to +50 degrees with respect to the film normal direction using Re (λ) as the in-plane slow axis (determined by KOBRA 21ADH or WR) as the inclination axis (rotation axis). 11 points of measurement were made by injecting light having a wavelength of λ nm from the inclined direction, respectively, and KOBRA 21ADH or WR was calculated based on the measured retardation value, the assumption value of the average refractive index, and the input film thickness value.

As the hypothesized value of the average refractive index in the above measurement, a polymer handbook (JOHN WILEY & SONS, INC) and a catalog value of various optical films can be used. An average refractive index value can be measured with an Abbe refractometer. The value of the average refractive index of a main optical film is illustrated below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), polystyrene (1.59). KOBRA 21ADH or WR calculates nx, ny, and nz by inputting the assumption values of these average refractive indices and the film thickness. From this calculated nx, ny, and nz, Nz = (nx-nz) / (nx-ny) is further calculated.

The angle θ formed between the film forming direction (length direction) and the slow axis of Re of the film is preferably closer to 0 °, + 90 °, or -90 °. That is, the vibration angles from 0 °, 90 °, and -90 ° are preferably within ± 3 °, more preferably within ± 2 °, even more preferably within ± 1 °. θ may be either 0 ° (vertical orientation), 90 °, or −90 ° (lateral orientation), but more preferably horizontal orientation. The in-plane and the deviation in the longitudinal direction of Re and Rth are preferably 0% to 8%, more preferably 0% to 5%, still more preferably 0% to 3%.

The change in Re and Rth before and after aging at 80 ° C for 200 hours is preferably 0% or more and 8% or less, more preferably 0% or more and 6% or less, still more preferably 0% or more and 4% or less. As for the dimension change of length MD and width TD before and after 80 degreeC 200 hours, all are 0% or more and ± 0.5% or less, More preferably, 0% or more and ± 0.3% or less, More preferably, 0% More than ± 0.1%

15 micrometers-200 micrometers are preferable, as for the thickness of the film after extending | stretching, More preferably, they are 20 micrometers-120 micrometers, More preferably, they are 25 micrometers-80 micrometers. The thickness nonuniformity is preferably 0% to 3% in both the longitudinal direction and the width direction, more preferably 0% to 2%, still more preferably 0% to 1%.

(Processing of film)

The resin film obtained in this way may be used independently, may be used in combination with these and a polarizing plate, and may form and use the layer (low reflection layer) and hard-coat layer which controlled the liquid crystal layer and refractive index on these. These can be achieved by the following steps.

"Surface treatment"

By surface-treating, adhesion with each functional layer (for example, undercoat and back layer) can be improved. For example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment herein includes a low temperature plasma treatment occurring under a low pressure gas of 10-3 to 20 Torr (0.13 to 2700 Pa). In addition, plasma treatment under atmospheric pressure is also a preferable glow discharge treatment.

Among these, preferable are a glow discharge treatment, a corona treatment, and a flame treatment, and more preferable is a corona treatment.

It is also preferable to form an undercoat layer for adhesion with the functional layer. This layer may be applied after surface treatment, or may be applied without surface treatment. Details of the undercoat are described on page 32 in the Published Journal of the Invention Association (Japanese Laid-Open Publication No. 2001-1745, issued March 15, 2001, the Invention Association). These surface treatment and undercoating process may be comprised at the end of a film forming process, may be performed independently, and may be performed in the functional layer provision process mentioned later.

<< grant of functional layer >>

Combining the functional layer described in detail on pages 32 to 45 in the invention association published report (Japanese Laid-Open Publication No. 2001-1745, issued March 15, 2001, the Society of Inventions) to the cycloolefin resin film of the present invention desirable. Among them, preferable are provision of a polarizing layer (polarizing plate), provision of an optically anisotropic layer (optical compensation layer), and provision of an antireflection layer (antireflection film).

[Optical anisotropic layer]

It is preferable to design an optically anisotropic layer so that the liquid crystalline compound in a liquid crystal cell in black display of a liquid crystal display device may be compensated. The alignment state of the liquid crystal compound in the liquid crystal cell in black display varies with the mode of the liquid crystal display device. About the orientation state of the liquid crystal compound in this liquid crystal cell, it describes in P411-414 etc. of IDW'00, FMC7-2.

The optically anisotropic layer is formed of the liquid crystal compound directly on the support or through the alignment layer. It is preferable that an oriented film has a film thickness of 10 micrometers or less.

The liquid crystalline compound used for an optically anisotropic layer contains a rod-like liquid crystalline compound and a discotic liquid crystalline compound. The rod-like liquid crystal compound and the discotic liquid crystal compound may be polymer liquid crystals or low molecular liquid crystals, and also include those in which the low molecular liquid crystals are crosslinked so as not to exhibit liquid crystallinity. The optically anisotropic layer can apply | coat a liquid crystal compound and the coating liquid containing a polymeric initiator and arbitrary components on an orientation film as needed. Preferred examples of the alignment film of the present invention are described in Japanese Patent Laid-Open No. 8-338913.

Rod-like liquid crystalline compound

As a rod-shaped liquid crystalline compound, azomethine, azoxy, cyano biphenyl, cyano phenyl ester, benzoic acid ester, cyclohexane carboxylic acid phenyl ester, cyano phenyl cyclohexane, cyano substituted phenyl pyrimidine , Alkoxy substituted phenylpyrimidines, phenyldioxanes, tolans and alkenylcyclohexylbenzonitriles are preferably used.

The rod-like liquid crystalline compound also includes a metal complex. In addition, the liquid crystal polymer which repeatedly contains a rod-like liquid crystalline compound in a unit can also be used as a rod-like liquid crystalline compound. That is, the rod-like liquid crystal compound may be combined with the (liquid crystal) polymer.

For the rod-shaped liquid crystalline compound, for example, Chapter 4, Chapter 7 and Chapter 11 of the chemistry (1994) Japanese Chemical Society of Liquid Crystal Summary Volume 22 liquid crystal and the Liquid Crystal Devices Handbook Japan Society for the Promotion of the 142 Chapter 3 Committee The thing described in the chapter can be employ | adopted.

It is preferable that birefringence of a rod-like liquid crystalline compound exists in the range of 0.001-0.7.

It is preferable that a rod-shaped liquid crystalline compound has a polymeric group in order to fix the orientation state. The polymerizable group is preferably an unsaturated polymerizable group or an epoxy group, more preferably an unsaturated polymerizable group, and most preferably an ethylenically unsaturated ¤ monomer.

[Discotic liquid crystalline compound]

Discotic liquid crystalline compounds include C. Destrade et al. Cryst. 71, 111 (p. 1981)} Benzene Derivatives, C. Destrade et al. Cryst. 122, pp. 141 (1985), Physics lett, A, 78, 82 (1990)}, the report of the Truthsen derivative, B. Kohne et al. Chem, Vol. 96, p. 70 (1984) and the research reports of J. M. Lehn et al. C. S., Chem. Commun., 1794 (1985)} J. Zhang et al. Am. Chem. Soc. 116, p. 2655 (1994)}, including azacrown-based and phenylacetylene-based macrocycles.

The discotic liquid crystal compound also includes a compound having a structure in which a linear alkyl group, an alkoxy group, and a substituted benzoyloxy group are radially substituted as the side chain of the mother nucleus with respect to the mother nucleus of the molecular center. It is preferable that a molecule | numerator or an aggregate of molecules is a compound which has rotational symmetry and can give a fixed orientation. In the optically anisotropic layer formed of the discotic liquid crystalline compound, the compound finally contained in the optically anisotropic layer does not have to be a discotic liquid crystalline compound. For example, low molecular discotic liquid crystalline molecules react with heat or light. Also included are compounds having a group to be polymerized or crosslinked by reaction with heat and light, resulting in high molecular weight, and which have lost liquid crystallinity. Preferred examples of the discotic liquid crystalline compound are described in Japanese Patent Laid-Open No. 8-50206. Moreover, about the superposition | polymerization of a discotic liquid crystalline compound, it is described in Unexamined-Japanese-Patent No. 8-27284.

In order to fix a discotic liquid crystalline compound by superposition | polymerization, it is necessary to couple a polymeric group as a substituent to the disk-shaped core of a discotic liquid crystalline compound. However, when a polymeric group is directly connected to a disk-shaped core, it becomes difficult to maintain an orientation state in a polymerization reaction. Thus, a linking group is introduced between the discotic core and the polymerizable group. Therefore, it is preferable that the discotic liquid crystalline compound which has a polymeric group is a compound represented by following formula (5).

General formula (5)

D (-LQ) _r

{In General formula (5), D is a disk-shaped core, L is a bivalent coupling group, Q is a polymeric group, and r is an integer of 4-12.}

An example of (D) of a disk-shaped core is shown below. In each of the following examples, LQ (or QL) means a combination of a divalent linking group (L) and a polymerizable (Q).

In general formula (5), the divalent linking group (L) is 2 selected from the group consisting of alkylene group, alkenylene group, arylene group, -CO-, -NH-, -O-, -S- and combinations thereof It is preferable that it is a valent coupling group. The divalent linking group (L) is more preferably a divalent linking group in which at least two divalent groups selected from the group consisting of an alkylene group, an arylene group, -CO-, -NH-, -O- and -S- are combined. . The divalent linking group (L) is most preferably a divalent linking group in which at least two divalent groups selected from the group consisting of an alkylene group, an arylene group, -CO- and -O- are combined. It is preferable that carbon number of an alkylene group is 1-12. It is preferable that carbon number of an alkenylene group is 2-12. It is preferable that carbon number of an arylene group is 6-10.

Examples of the divalent linking group L are shown below. The left side is coupled to the disk-shaped core (D), and the right side is coupled to the polymerizable group (Q). AL means an alkylene group or an alkenylene group, and AR means an arylene group. In addition, the alkylene group, the alkenylene group, and the arylene group may have a substituent (for example, an alkyl group).

L1: -AL-CO-O-AL-,

L2: -AL-CO-O-AL-O-,

L3: -AL-CO-O-AL-O-AL-,

L4: -AL-CO-O-AL-O-CO-,

L5: -CO-AR-O-AL-,

L6: -CO-AR-O-AL-O-,

L7: -CO-AR-O-AL-O-CO-,

L8: -CO-NH-AL-,

L9: -NH-AL-O-,

L10: -NH-AL-O-CO-,

L11: -O-AL-,

L12: -O-AL-O-,

L13: -O-AL-O-CO-,

L14: -O-AL-O-CO-NH-AL-,

L15: -O-AL-S-AL-,

L16: -O-CO-AL-AR-O-AL-O-CO-,

L17: -O-CO-AR-O-AL-CO-,

L18: -O-CO-AR-O-AL-O-CO-,

L19: -O-CO-AR-O-AL-O-AL-O-CO-,

L20: -O-CO-AR-O-AL-O-AL-O-AL-O-CO-,

L21: -S-AL-,

L22: -S-AL-O-,

L23: -S-AL-O-CO-,

L24: -S-AL-S-AL-,

L25: -S-AR-AL-.

The polymerizable group (Q) of General formula (5) is determined according to the kind of polymerization reaction. Examples of the polymerizable group (Q) are shown below.

The polymerizable group (Q) is preferably an unsaturated polymerizable group (Q1, Q2, Q3, Q7, Q8, Q15, Q16, Q17) or an epoxy group (Q6, Q18), more preferably an unsaturated polymerizable group, and ethylenically unsaturated Most preferably, it is a polymerizable group (Q1, Q7, Q8, Q15, Q16, Q17). The specific value of r is determined according to the type of disk-shaped core D. Moreover, although the combination of some L and Q may differ, it is preferable that they are the same.

In the hybrid orientation, the angle of the major axis (distal surface) of the discotic liquid crystal compound and the surface of the support, that is, the inclination angle, is determined in the direction of the depth of the optically anisotropic layer (ie, perpendicular to the transparent support) and from the surface of the polarizing film. It is increasing or decreasing with increase. The angle is preferably increased with increasing distance. In addition, the change of the inclination angle is possible by the continuous increase, the continuous decrease, the intermittent increase, the intermittent decrease, the change including the continuous increase and the continuous decrease, or the intermittent change including the increase and the decrease. The intermittent change includes a region in which the inclination angle does not change in the middle of the thickness direction. Even if it contains the area | region which does not change an angle, it should just increase or decrease as a whole. However, the inclination angle is preferably changed continuously.

The average direction (average of the major axis direction of each molecule) of the long axis (circular surface) of the discotic liquid crystal compound can generally be adjusted by selecting the material of the discotic liquid crystal compound or the alignment film or by selecting the rubbing treatment method. In addition, the long-axis (circle surface) direction of the discotic liquid crystalline compound on the surface side (air side) can generally be adjusted by selecting the kind of additive used with a discotic liquid crystalline compound or a discotic liquid crystalline compound.

As an example of the additive used with a discotic liquid crystalline compound, a plasticizer, surfactant, a polymerizable monomer, a polymer, etc. are mentioned. The degree of change in the orientation direction of the major axis can also be adjusted in accordance with the selection of the liquid crystal molecules and the additives in the same manner as above.

The plasticizers, surfactants and polymerizable monomers used in combination with the discotic liquid crystalline compound are compatible with the discotic liquid crystalline compound, and may preferably change the inclination angle of the discotic liquid crystalline compound or do not inhibit orientation. Do. Among the additive components, addition of a polymerizable monomer (eg, a compound having a vinyl group, vinyloxy group, acryloyl group, and methacryloyl group) is preferable. It is preferable that the addition amount of the said compound exists in the range of 1-50 mass% with respect to a discotic liquid crystalline compound generally, and exists in the range of 5-30 mass%. Moreover, adhesiveness between an oriented film and an optically anisotropic layer can be improved by using the monomer whose polymerizable reactive functional group number is 4 or more.

The optically anisotropic layer may contain a polymer together with a discotic liquid crystalline compound. It is preferable that the polymer is compatible with the discotic liquid crystal compound to some extent and can change the tilt angle of the discotic liquid crystal compound. Examples of the polymer include cellulose esters. Preferable examples of the cellulose esters include cellulose acetate, cellulose acetate propionate, hydroxypropyl cellulose and cellulose acetate butyrate. It is preferable to exist in the range of 0.1-10 mass% with respect to a discotic liquid crystalline compound, and, as for the addition amount of the said polymer so that the orientation of a discotic liquid crystalline compound is not impaired, it is more preferable to exist in the range of 0.1-8 mass%, It is more preferable to exist in the range of 0.1-5 mass%. The discotic nematic liquid crystal phase-solid phase transition temperature of the discotic liquid crystalline compound is preferably 70 to 300 ° C °, more preferably 70 to 170 ° C.

[Fixing the Orientation State of Liquid Crystal Molecules]

The liquid crystal molecules oriented can be fixed while maintaining the alignment state. It is preferable to perform fixation by a polymerization reaction. The polymerization reaction includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. Photopolymerization reaction is preferred.

Examples of photopolymerization initiators include α-carbonyl compounds (US Pat. No. 23,67661, US Pat. No. 2367670), Acyloinether (US Pat. No. 2448828), α-Hydrocarbon Substituted Aromatic Acyloins (US Pat. No. 2722512) US Patent No. 3046127, the respective publications of US Pat. No. 2951758), a combination of triarylimidazole dimers and p-aminophenyl ketones (US Pat. No. 3549367), acridine and phena Gin compounds (Japanese Patent Laid-Open No. 60-105667, described in each publication of US Pat. No. 4239850) and oxadiazole compounds (described in US Pat. No. 4212970).

It is preferable to exist in the range of 0.01-20 mass% of solid content of a coating liquid, and, as for the usage-amount of a photoinitiator, it is more preferable to exist in the range which is 0.5-5 mass%.

It is preferable to use ultraviolet rays for light irradiation for the polymerization of the liquid crystalline molecules.

It is preferable that irradiation energy exists in the range of 20mJ / cm <2> -50J / cm <2>, It is more preferable to exist in the range of 20mJ / cm <2> -5000mJ / cm <2>, It is more preferable to exist in the range of 100mJ / cm <2> -800mJ / cm <2>. Further, in order to promote the photopolymerization reaction, light irradiation may be performed under heating conditions.

You may form a protective layer on an optically anisotropic layer.

The said optically anisotropic layer can be formed by preparing the coating liquid containing at least 1 sort (s) of the said liquid crystalline compound and additives, such as a polymeric initiator and a fluorine-type polymer, as needed, and apply | coating and drying the said coating liquid on the surface of an oriented film. have.

Although a conventionally well-known compound is mentioned as a fluorine-type compound, For example, the fluorine-type compound etc. as described in Paragraph No. 0028-0056 in Unexamined-Japanese-Patent No. 2001-330725 are mentioned.

As a solvent used for preparation of a coating liquid, an organic solvent is used preferably. Examples of organic solvents include amides (eg N, N-dimethylformamide), sulfoxides (eg dimethyl sulfoxide), heterocyclic compounds (eg pyridine), hydrocarbons (eg benzene, hexane), alkyl halides (eg , Chloroform, dichloromethane, tetrachloroethane), esters (e.g. methyl acetate, butyl acetate), ketones (e.g. acetone, methyl ethyl ketone), ethers (e.g. tetrahydrofuran, 1,2-dimethoxyethane) Included. Alkyl halides and ketones are preferred. You may use together 2 or more types of organic solvents.

When producing a highly uniform optical compensation film, it is preferable that the surface tension of the said coating liquid is 25 mN / m or less, and it is more preferable that it is 22 mN / m or less.

Application | coating of a coating liquid can be performed by a well-known method (for example, extrusion coating method, direct gravure coating method, reverse gravure coating, die coating method).

[Polarizing Plate]

(Polarizing film)

As for the polarizing film which can be used for the polarizing plate of this invention, the polarizing film which consists of an application-type polarizing film or binder represented by thing made from Optiva company, and an iodine or a dichroic dye is preferable.

The iodine and the dichroic dye in the polarizing film exhibit deflection performance by being oriented in a binder. The iodine and the dichroic dye are preferably oriented along the binder molecule or the dichroic dye is oriented in one direction by self-organization such as liquid crystal.

A general-purpose polarizer can be produced, for example, by immersing the stretched polymer in a solution of iodine or a dichroic dye in a bath and infiltrating an iodine or a dichroic dye in a binder.

In the general-purpose polarizing film, an iodine or a dichroic dye is distributed at about 4 μm (about 8 μm in both sides) from the polymer surface, and a thickness of at least 10 μm is required to obtain sufficient polarization performance. Permeability can be controlled by the solution concentration of an iodine or dichroic dye, the temperature of the copper bath, and the immersion time.

As mentioned above, it is preferable that the minimum of binder thickness is 10 micrometers. On the other hand, the upper limit of the thickness is not particularly limited, but the thinner it is, the better it is from the viewpoint of the light leakage phenomenon generated when the polarizing plate is used in the liquid crystal display device. At present, it is preferable that it is below a general-purpose polarizing plate (about 30 micrometers), 25 micrometers or less are preferable, and 20 micrometers or less are more preferable. If it is 20 micrometers or less, a light leakage phenomenon will not be observed in a 17-inch liquid crystal display device.

The binder of the polarizing film may be crosslinked. The crosslinked binder can use a polymer which can itself crosslink. A binder obtained by introducing a functional group into a polymer having a functional group or a polymer can be reacted between the binders according to light, heat or pH change to form a polarizing film.

Moreover, you may introduce a crosslinked structure into a polymer with a crosslinking agent. It can form by crosslinking between binders by introduce | transducing the coupling group derived from a crosslinking agent between binders using the crosslinking agent which is a compound with high reaction activity.

Crosslinking is generally performed by apply | coating the coating liquid containing a polymer or a mixture of a polymer and a crosslinking agent on a transparent support body, and then heating. Since durability can be ensured at the end of the final product, the crosslinking treatment may be performed at any stage until the final polarizing plate is obtained.

The binder of a polarizing film can use both the polymer itself crosslinkable, or the polymer crosslinked by a crosslinking agent. Examples of the polymer include polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, polystyrene, gelatin, polyvinyl alcohol, modified polyvinyl alcohol, poly (N-metholacrylamide), polyvinyl toluene, chlorosulfonated polyethylene, Nitrocellulose, chlorinated polyolefins (e.g. polyvinyl chloride), polyesters, polyimides, polyvinyl acetate, polyethylene, carboxymethylcellulose, polypropylene, polycarbonates and copolymers thereof (e.g. acrylic acid / methacrylic acid polymers, styrene / Maleimide polymer, styrene / vinyltoluene polymer, vinyl acetate / vinyl chloride polymer, ethylene / vinyl acetate polymer). Water-soluble polymers {e.g., poly (N-methyrolacrylamide), carboxymethylcellulose, gelatin, polyvinyl alcohol and modified polyvinyl alcohol) are preferred, gelatin, polyvinyl alcohol and modified polyvinyl alcohol are more preferred, and poly Most preferred are vinyl alcohol and modified polyvinyl alcohol.

The saponification degree of polyvinyl alcohol and modified polyvinyl alcohol is preferably 70 to 100%, more preferably 80 to 100%, and most preferably 95 to 100%. As for the polymerization degree of polyvinyl alcohol, 100-5000 are preferable.

Modified polyvinyl alcohol is obtained by introducing a modifying group by copolymerization modification, chain transfer modification or block polymerization modification to polyvinyl alcohol. In the copolymerization modification, -COONa, -Si (OH) ₃ , N (CH ₃ ) ₃ Cl, C ₉ H ₁₉ COO-, -SO ₃ Na, and -C ₁₂ H ₂₅ may be introduced as the modifying group. In the chain transfer denaturation, -COONa, -SH, -SC ₁₂ H ₂₅ can be introduced as the modifying group. As for the polymerization degree of modified polyvinyl alcohol, 100-3000 are preferable. The modified polyvinyl alcohol is described in Japanese Patent Application Laid-Open Nos. 8-338913, 9-152509 and 9-316127.

Unmodified polyvinyl alcohol and alkylthio modified polyvinyl alcohol having a saponification degree of 85 to 95% are particularly preferred.

Polyvinyl alcohol and modified polyvinyl alcohol may use 2 or more types together.

When the crosslinking agent of a binder is added a lot, the heat and moisture resistance of a polarizing film can be improved. However, when 50 mass% or more of crosslinking agents are added with respect to a binder, the orientation of an iodine or a dichroic dye will fall. 0.1-20 mass% is preferable with respect to a binder, and, as for the addition amount of a crosslinking agent, 0.5-15 mass% is more preferable.

The binder contains a crosslinking agent that has not reacted to some extent even after the crosslinking reaction is completed. However, it is preferable that it is 1.0 mass% or less in a binder, and, as for the quantity of the remaining crosslinking agent, it is more preferable that it is 0.5 mass% or less. If a crosslinking agent is contained in the quantity exceeding 1.0 mass% in a binder layer, a problem may arise in durability. That is, when the polarizing film with many residual amounts of a crosslinking agent is attached to a liquid crystal display device, and is left to stand for a long time in the atmosphere of long-term use or high temperature, high humidity, the fall of polarization degree may generate | occur | produce.

Crosslinking agents are described in US Pat. No. 23297. In addition, boron compounds (eg, boric acid, borax) can also be used as the crosslinking agent.

As the dichroic dye, an azo dye, a stilbene dye, a pyrazolone dye, a triphenylmethane dye, a quinoline dye, an oxazine dye, a thiazine dye or an anthraquinone dye is used. It is preferable that a dichroic dye is water-soluble. The dichroic dye preferably has a hydrophilic substituent (eg, sulfo, amino, hydroxyl).

Examples of the dichroic dye include CI Direct Yellow 12, CI Direct Orange 39, CI Direct Orange 72, CI Direct Red 39, CI Direct Red 79, CI Direct Red 81, CI Direct Red 83, CI Direct Red 89, and CI Direct Violet 48. CI direct blue 67, CI direct blue 90, CI direct green 59, and CI acid red 37 are included. About dichroic dyes, each of Japanese Patent Application Laid-Open Nos. 1-161,202, 1-172906, 1-172907, 1-183602, 1-248105, 1-265205, and 7-261024 Publications are described. Dichroic dyes are used as the free acid or alkali metal salt, ammonium salt or amine salt. By mix | blending two or more types of dichroic dyes, the polarizing film which has various colors can be manufactured. The polarizing film or polarizing plate which mix | blended various dichroic molecules so that black may show the polarizing film using the compound (color) which shows black when a polarizing axis orthogonally crosses is also excellent in single plate transmittance and polarization rate, and is preferable.

In order to raise the contrast ratio of a liquid crystal display device, it is preferable that the transmittance | permeability of a polarizing plate is preferable, and it is preferable that the polarization degree is also higher. The transmittance of the polarizing plate is preferably in the range of 30 to 50% for light having a wavelength of 550 nm, more preferably in the range of 35 to 50%, and in the range of 40 to 50% (of the single plate transmittance of the polarizing plate). Maximum value is 50%). The degree of polarization is preferably in the range of 90 to 100% for light having a wavelength of 550 nm, more preferably in the range of 95 to 100%, and most preferably in the range of 99 to 100%.

It is also possible to arrange | position a polarizing film and an optically anisotropic layer or a polarizing film and an oriented film through an adhesive agent. As the adhesive, a polyvinyl alcohol-based resin (including modified polyvinyl alcohol based on acetoacetyl group, sulfonic acid group, carboxyl group and oxyalkylene group) or an aqueous solution of boron compound may be used. Especially, polyvinyl alcohol-type resin is preferable. It is preferable to exist in the range of 0.01-10 micrometers after drying, and it is especially preferable to exist in the range which is 0.05-5 micrometers after drying.

(Manufacture of Polarizing Plate)

The polarizing film is preferably dyed by iodine or a dichroic dye after stretching the binder (stretching method) or rubbing (rubbing method) by inclining the binder 10 to 80 degrees with respect to the longitudinal direction (MD direction) of the polarizing film in terms of yield. . It is preferable to extend | stretch so that the inclination-angle may match the angle which the transmission axis of the two polarizing plates adhere | attached on the both sides of the liquid crystal cell which comprises LCD, and the longitudinal or horizontal direction of a liquid crystal cell make.

Typical inclination angle is 45 degrees. Recently, however, devices which are not necessarily 45 degrees have been developed in transmissive, reflective and transflective LCDs, and it is preferable that the stretching direction can be arbitrarily adjusted in accordance with the design of the LCD.

In the stretching method, the stretching ratio is preferably from 2.5 to 30.0 times, more preferably from 3.0 to 10.0 times. Stretching can be performed by dry stretching in air. Also. You may perform wet stretching in the state immersed in water. The elongation of dry stretching is preferably 2.5 to 5.0 times, and the elongation of wet stretching is preferably 3.0 to 10.0 times. An extending process may be divided into several times including diagonal stretch. By dividing into several times, it can extend | stretch more uniformly even in high magnification extending | stretching. You may perform some extending | stretching (a grade which prevents contraction of the width direction) before or after diagonal stretch. In addition, the elongation rate here means a mark on a film before extending | stretching, and is represented by ratio (L '/ L) of the length L before the extending | stretching and the length L' after extending | stretching.

Stretching can be performed by carrying out tenter stretching in biaxial stretching at different stages. The said biaxial stretching is the same as the extending | stretching method performed in normal film film forming. In biaxial stretching, since it extends by different speeds left and right, it is necessary to make thickness of the binder film before extending | stretching different from left to right. In flexible film forming, the taper is attached to the die to form a difference between the left and right in the flow rate of the binder solution.

As mentioned above, the binder film 10-80 degree diagonally stretched with respect to MD direction of a polarizing film is manufactured.

In the rubbing method, a rubbing treatment method widely adopted as a liquid crystal alignment treatment step of LCD can be applied. That is, the orientation is obtained by rubbing the surface of the film in a certain direction using paper, gauze, felt, rubber or nylon, or polyester fibers. Generally, it is performed by rubbing about several times using the cloth which averaged the fiber of uniform length and thickness. It is preferable to carry out using the rubbing roll whose roundness, cylinder degree, and vibration (eccentricity) of a roll itself are all 30 micrometers or less. As for the lapping angle of the film to a rubbing roll, 0.1-90 degree is preferable. However, as described in Unexamined-Japanese-Patent No. 8-160430, it can also obtain stable rubbing process by winding around 360 degree or more.

When rubbing a long film, it is preferable to convey a film by the conveying apparatus at the speed of 1-100 m / min in the state of constant tension. It is preferable that a rubbing roll becomes rotatable horizontally with respect to a film advancing direction for arbitrary rubbing angle settings. It is preferable to select an appropriate rubbing angle in the range of 0 to 60 degrees. When using for a liquid crystal display device, 40-50 degree is preferable. 45 degrees is particularly preferred.

[Liquid crystal display device]

The optical film manufactured by the manufacturing method of the cycloolefin resin film of this invention can be used for the liquid crystal display device of various modes. Hereinafter, the preferable aspect of the optically anisotropic layer in each liquid crystal mode is demonstrated.

(TN mode liquid crystal display)

The liquid crystal cell of TN mode is most used as a color TFT liquid crystal display device, and many documents have description.

In the orientation state in the liquid crystal cell in the black display of TN mode, the rod-like liquid crystalline molecule stands up in the cell center part, and the rod-like liquid crystalline compound is in the alignment state lying in the cell substrate vicinity.

The rod-like liquid crystalline compound in the center portion of the cell is compensated by a discotic liquid crystalline compound or a (transparent) support in a homeotropic orientation (horizontal orientation in which the disk lies), and the rod-like liquid crystal near the substrate of the cell. About a compound, it can compensate by the discotic liquid crystalline compound of hybrid orientation (an orientation in which the inclination of a long axis changes with distance with a polarizing film).

In addition, about the rod-like liquid crystalline compound of the cell center part, it compensates with the rod-like liquid crystalline compound of a homogeneous orientation (horizontal orientation in which a long axis lays), or a (transparent) support body, and hybrid about the rod-shaped liquid crystalline compound near the board | substrate of a cell. It may also be compensated by the discotic liquid crystalline compound of orientation.

The liquid crystalline compound of homeotropic orientation is oriented in the state whose average orientation direction of the long axis of a liquid crystalline compound and the angle of the surface of a polarizing film are 85-95 degree | times.

The liquid crystal compound of homogeneous orientation is oriented in the state in which the average orientation direction of the long axis of a liquid crystal compound and the angle of the surface of a polarizing film are less than 5 degrees.

It is preferable that the average orientation direction of the long axis of a liquid crystal compound, and the angle of the surface of a polarizing film are 15 degrees or more, and, as for the liquid crystal compound of hybrid orientation, it is more preferable that they are 15 degrees-85 degrees.

Optically anisotropic layer in which the support or discotic liquid crystal compound is homeotropically oriented or optically anisotropic layer in which the homogeneous orientation of the rod-like liquid crystalline compound is homogeneous; It is preferable that Rth retardation value is 40 nm-200 nm, and Re retardation value is 0-70 nm of the optically anisotropic layer which consists of a mixture of an acidic compound.

Discotic liquid crystalline compound layers in homeotropic alignment (horizontal alignment) and rod-like liquid crystalline compound layers in homogeneous alignment (horizontal alignment) are described in Japanese Unexamined Patent Publications Nos. 12-304931 and 12-304932. It is. As for the hybrid oriented discotic liquid crystalline compound layer, it is described in Unexamined-Japanese-Patent No. 8-50206.

(OCB Mode Liquid Crystal Display)

The liquid crystal cell of OCB mode is a liquid crystal cell of band alignment mode which orientates the rod-like liquid crystalline compound substantially in the reverse direction (symmetrically) at the top and bottom of the liquid crystal cell. A liquid crystal display device using a liquid crystal cell in a band alignment mode is disclosed in the publications of US Patent 4583825 and 5410422. Since the rod-like liquid crystal compound is symmetrically oriented at the top and bottom of the liquid crystal cell, the liquid crystal cell in the band alignment mode has a magneto-optical compensation function. For this reason, this liquid crystal mode is called OCB (Optically Compensatory Bend) liquid crystal mode.

Similarly to the TN mode, the liquid crystal cell of the OCB mode is in the alignment state in which the rod-like liquid crystal compound stands up at the cell center portion, and the rod-like liquid crystal compound is in the alignment state in the vicinity of the substrate of the cell.

Since the alignment of the TN mode and the liquid crystal in the black display is the same state, the preferred form is also the same as the TN mode correspondence. However, in the OCB mode, the optically anisotropic layer or rod-like liquid crystal compound in which the discotic liquid crystal compound is homeotropically aligned is homogeneous in the OCB mode because the range in which the liquid crystal compound stands up in the cell center is larger than that in the TN mode. Some adjustment of the retardation value is necessary for the anisotropic layer. Specifically, the optically anisotropic layer in which the discotic liquid crystalline compound on the support is homeotropically oriented or the optically anisotropic layer in which the rod-like liquid crystalline compound is homogeneously oriented has a Rth retardation value of 150 nm to 500 nm. It is preferable that a value is 20-70 nm.

(VA mode liquid crystal display)

In the liquid crystal cell of VA mode, rod-shaped liquid crystalline compounds are orientated substantially vertically when voltage is not applied.

In the liquid crystal cell of VA mode, (1) the liquid crystal cell of narrow VA mode which orientates a rod-shaped liquid crystalline compound substantially vertically when a voltage is not applied, and is substantially horizontally oriented when voltage is applied (Japanese Patent Laid-Open No. 2-176625). (2) a liquid crystal cell (in MVA mode) in which the VA mode is multi-domained to enlarge the viewing angle (SID97, Digest of tech. Papers (Preliminary Proceedings) 28 (1997) 845 substrate}, (3) Liquid crystal cell in a mode (n-ASM mode) in which a rod-like liquid crystalline compound is substantially vertically aligned when no voltage is applied, and is twisted and multi-domain aligned when voltage is applied. {Based on the preliminary publication 58-59 (1998) of the liquid crystal debate of Japan] and (4) the liquid crystal cell of SURVAIVAL mode (presented by LCD International 98).

In the black display of the VA mode liquid crystal display device, since most of the rod-like liquid crystalline compounds in the liquid crystal cell are in a standing state, the optical anisotropic layer or rod-like liquid crystalline compound in which the discotic liquid crystalline compound is homeotropically aligned is homogeneous. The liquid crystal compound is compensated by the oriented optically anisotropic layer, and the rod-like liquid crystal compound is homogeneously oriented separately, and the optical anisotropy is less than 5 degrees in the average alignment direction of the long axis of the rod-like liquid crystal compound and the transmission axis direction of the polarizing film. It is preferable to compensate the visual dependence of the polarizing plate by the layer.

The optically anisotropic layer in which the support or discotic liquid crystal compound is homeotropically aligned, or the optically anisotropic layer in which the rod-like liquid crystal compound is homogeneously aligned, has a Rth retardation value of 150 nm to 500 nm and a Re retardation value of 20. It is preferable that it is -70 nm.

(Other liquid crystal display)

The liquid crystal display of the ECB mode and the STN mode can be optically compensated by the same thinking scheme as described above.

(A) Provision of an antireflection layer (antireflection film)

You may provide an antireflection layer on the cycloolefin resin film of this invention. The anti-reflection film is formed by providing a low refractive index layer, which is also an antifouling layer, and at least one layer (that is, a high refractive index layer, a medium refractive index layer) having a higher refractive index than the low refractive index layer on a transparent substrate.

A multi-layered film in which transparent thin films of inorganic compounds (metal oxides, etc.) having different refractive indices are laminated, and a colloidal metal oxide particle film is formed by a sol-gel method of a metal compound such as chemical vapor deposition (CVD), physical vapor deposition (PVD), or metal alkoxide. After forming, a post-treatment (ultraviolet irradiation: Unexamined-Japanese-Patent No. 9-157855, plasma processing: Unexamined-Japanese-Patent No. 2002-327310) is mentioned, and the method of forming a thin film is mentioned.

On the other hand, various anti-reflection films formed by laminating and applying a thin film formed by dispersing inorganic particles in a matrix as a highly productive anti-reflection film have been proposed.

The antireflection film which consists of an antireflection layer which provided the anti-glare property which the uppermost layer surface has a fine uneven | corrugated shape to the antireflection film by application | coating as mentioned above is also mentioned.

The cycloolefin-based resin film of the present invention can be applied to any of the above methods, but a particularly preferred method is a coating method (coating type).

(A-1) Layer composition of coating type antireflection film

The antireflection film having a layer structure of at least a medium refractive index layer, a high refractive index layer, and a low refractive index layer (outermost layer) on the substrate is designed to have a refractive index that satisfies the following relationship.

Refractive Index of High Refractive Index Layer> Refractive Index of Middle Refractive Index Layer> Refractive Index of Transparent Support Body> Refractive Index of Low Refractive Index Layer

Further, a hard coat layer may be formed between the transparent support and the medium refractive index layer. It may also be composed of a medium refractive index hard coat layer, a high refractive index layer and a low refractive index layer.

For example, Unexamined-Japanese-Patent No. 8-122504, 8-110401, 10-300902, Unexamined-Japanese-Patent No. 2002-243906, Unexamined-Japanese-Patent No. 2000-111706, etc. are mentioned. .

In addition, different functions may be provided to each layer, for example, an antifouling low refractive index layer and an antistatic high refractive index layer (e.g., Japanese Patent Laid-Open No. 10-206603, Japanese Patent Laid-Open No. 2002-243906). Call publications etc.) etc. are mentioned.

The haze of the antireflection film is preferably 5% or less, more preferably 3% or less. In addition, the strength of the film is preferably H or more in a pencil hardness test according to JIS K5400, more preferably 2H or more, and most preferably 3H or more.

(A-2) High refractive index layer and medium refractive index layer

The layer having a high refractive index of the antireflective film is composed of a curable film containing at least an inorganic compound ultrafine particles having a high refractive index and a matrix binder having an average particle size of 100 nm or less.

Examples of the high refractive index inorganic compound fine particles include inorganic compounds having a refractive index of 1.65 or more, and those having a refractive index of 1.9 or more are preferable. For example, oxides, such as Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, In, complex oxide containing these metal atoms, etc. are mentioned.

In order to make such ultrafine particles, the surface of the particles is treated with a surface treating agent (for example, a silane coupling agent or the like: Japanese Patent Application Laid-Open No. 11-295503, Japanese Patent Application Laid-Open No. 11-153703, Japanese Patent Application Laid-Open No. 2000-9908). Anionic compounds or organometallic coupling agents: Japanese Patent Laid-Open No. 2001-310432, etc.), having a core-shell structure with high refractive index particles as a core (Japanese Patent Laid-Open No. 2001-166104, etc.), using a specific dispersant in combination ( For example, Unexamined-Japanese-Patent No. 11-153703, Unexamined-Japanese-Patent No. US6210858B1, Unexamined-Japanese-Patent No. 2002-2776069, etc. are mentioned.

As a material which forms a matrix, a conventionally well-known thermoplastic resin, curable resin film, etc. are mentioned.

Further, at least one composition selected from a polyfunctional compound-containing composition containing at least two radically polymerizable and / or cationic polymerizable polymerizable groups, an organometallic compound containing a hydrolyzable group, and a partial condensate composition thereof is preferable. Do. For example, the compound described in Unexamined-Japanese-Patent No. 2000-47004, 2001-315242, 2001-31871, 2001-296401, etc. are mentioned.

Moreover, the curable film obtained from the colloidal metal oxide and metal alkoxide composition obtained from the hydrolysis-condensation product of a metal alkoxide is also preferable. For example, it is described in Unexamined-Japanese-Patent No. 2001-293818.

The refractive index of the high refractive index layer is generally 1.70 to 2.20. It is preferable that it is 5 nm-10 micrometers, and, as for the thickness of a high refractive index layer, it is more preferable that it is 10 nm-1 micrometer.

The refractive index of the medium refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. It is preferable that the refractive index of the medium refractive index layer is 1.50-1.70.

(A-3) Low refractive index layer

The low refractive index layer is formed by sequentially laminating on the high refractive index layer. The refractive index of the low refractive index layer is 1.20 to 1.55. Preferably it is 1.30-1.50.

It is preferable to construct as an outermost layer which has scratch resistance and antifouling property. As a means of greatly improving scratch resistance, provision of slip to the surface is effective, and a means of a thin film layer made of conventionally known silicon introduction, fluorine introduction, or the like can be applied.

It is preferable that the refractive index of a fluorine-containing compound is 1.35-1.50. More preferably, it is 1.36-1.47. Moreover, the compound which contains the crosslinkable or polymerizable functional group which contains a fluorine atom in the range of 35-80 mass% is preferable.

For example, Japanese Patent Laid-Open No. 9-222503, Japanese Patent Application Laid-Open No. 2001-40284, paragraphs [0018] to [0026], and Japanese Patent Laid-Open No. 11-38202, paragraphs [0019] to [0030] Paragraph Nos.-The compound of Unexamined-Japanese-Patent No. 2000-284102, etc. are mentioned.

As a silicone compound, it is a compound which has a polysiloxane structure, contains a curable functional group or a polymerizable functional group in a polymer chain, and has a crosslinked structure in a film | membrane. For example, reactive silicones (for example, cyraprene (manufactured by Chisso Co., Ltd.) and the like, polysiloxanes containing silanol groups at both ends (Japanese Patent Laid-Open No. 11-258403, etc.), and the like can be given.

The crosslinking or polymerization reaction of a polymer of fluorine-containing and / or siloxane having a crosslinking or polymerizable group is carried out by simultaneously applying or applying light to the coating composition for forming the outermost layer containing a polymerization initiator, a sensitizer, or the like after irradiation or heating. It is preferable.

Moreover, the sol-gel cured film which hardens organometallic compounds, such as a silane coupling agent, and the specific fluorine-containing hydrocarbon group containing silane coupling agent by condensation reaction under catalyst coexistence is also preferable.

For example, a polyfluoroalkyl group containing silane compound or its partial hydrolysis condensate (Japanese Patent Laid-Open No. 58-142958, Japanese Patent Laid-Open No. 58-147483, Japanese Patent Laid-Open No. 58-147484, Japanese Patent Laid-Open No. 9-157582 Compounds described in Japanese Patent Application Laid-Open No. 11-106704 and the like), and a silyl compound containing a poly "perfluoroalkyl ether" group which is a fluorine-containing long chain group (Japanese Patent Laid-Open No. 2000-117902, Japanese Patent Laid-Open No. 2001-48590, And the like described in 2002-53804.

The low refractive index layer is a low refractive index inorganic material having an average diameter of primary particles, such as fillers (for example, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride), etc., as an additive other than the above. The compound, the organic fine particle etc. of Paragraph No. [0020]-[0038] of Unexamined-Japanese-Patent No. 11-3820, etc.}, a silane coupling agent, a lubricating agent, surfactant, etc. can be contained.

When the low refractive index layer is located below the outermost layer, the low refractive index layer may be formed by a vapor phase method (vacuum vapor deposition method, sputtering method, ion plating method, plasma CVD method, or the like). An application method is preferable at the point which can be manufactured inexpensively.

It is preferable that the film thickness of a low refractive index layer is 30-200 nm, It is more preferable that it is 50-150 nm, It is most preferable that it is 60-120 nm.

(A-4) Hard coat layer

The hard coat layer is formed on the surface of the transparent support to impart physical strength to the antireflection film. In particular, it is preferable to form between a transparent support body and the said high refractive index layer.

The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of a curable compound of light and / or heat.

As said curable functional group, a photopolymerizable functional group is preferable, and the organometallic compound containing a hydrolysable functional group is preferably an organic alkoxysilyl compound.

As a specific example of these compounds, the thing similar to what was illustrated by the high refractive index layer is mentioned.

As a specific structural composition of a hard-coat layer, the thing of Unexamined-Japanese-Patent No. 2002-144913, 2000-9908, International Publication No. 00/46617 pamphlet, etc. are mentioned, for example.

The high refractive index layer can also serve as a hard coat layer. In such a case, it is preferable to form by disperse | distributing microparticles | fine-particles finely and containing in a hard-coat layer using the method described by the high refractive index layer.

The hard coat layer may also serve as an antiglare layer (described later) in which particles having an average particle size of 0.2 to 10 µm are contained to impart an antiglare function (antiglare function).

The film thickness of a hard coat layer can be designed suitably according to a use. It is preferable that the film thickness of a hard-coat layer is 0.2-10 micrometers, More preferably, it is 0.5-7 micrometers.

The strength of the hard coat layer is preferably at least H, more preferably at least 2H, and most preferably at least 3H in a pencil hardness test according to JIS K5400. In the taper test according to JIS K5400, the smaller the amount of abrasion of the test piece before and after the test, the better.

(A-5) Forward scattering layer

The front scattering layer is formed in order to give a viewing angle improvement effect when the time is inclined in the up, down, left, and right directions when applied to the liquid crystal display device. It can also serve as a hard coat function by dispersing fine particles having different refractive indices in the hard coat layer.

For example, Japanese Unexamined Patent Application Publication No. 11-38208, which specifies a forward scattering coefficient, Japanese Unexamined Patent Application Publication No. 2000-199809 having a relative refractive index between a transparent resin and fine particles, and a haze value of 40% or more are specified. Japanese Unexamined Patent Publication No. 2002-107512 is mentioned.

(A-6) Other floor

In addition to the above layer, a primer layer, an antistatic layer, an undercoat or a protective layer may be formed.

(A-7) Application method

Each layer of the anti-reflection film is formed by a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coat, a micro gravure method or an extrusion coating method (US Patent 2681294 specification). It can form by application | coating.

(A-8) Antiglare function

The antireflection film may have an antiglare function for scattering external light. The antiglare function is obtained by forming irregularities on the surface of the antireflection film. When the antireflection film has an antiglare function, the haze of the antireflection film is preferably 3 to 30%, more preferably 5 to 20%, and most preferably 7 to 20%.

The method of forming the unevenness on the surface of the antireflection film can be applied to any method as long as it is a method capable of sufficiently maintaining these surface shapes. For example, a method of forming irregularities on the surface of the film using fine particles in the low refractive index layer (for example, Japanese Patent Laid-Open No. 2000-271878, etc.), a lower layer of the low refractive index layer (high refractive index layer, medium refractive index layer, or A small amount (0.1-50 mass%) of relatively large particles (particle size of 0.05 to 2 µm) is added to the hard coat layer to form a surface uneven film, and a method of forming a low refractive index layer by maintaining these shapes thereon (e.g., For example, Japanese Unexamined Patent Application Publication Nos. 2000-281410, 2000-95893, 2001-100004, 2001-281407, etc., and the top layer (antifouling layer) are physically transferred to the uneven shape on the surface after application. The method (for example, Unexamined-Japanese-Patent No. 63-278839, Unexamined-Japanese-Patent No. 11-183710, Unexamined-Japanese-Patent No. 2000-275401, etc.) is mentioned as an embossing process.

<< measurement method >>

It describes about the measuring method used by this invention below.

(1) Range of Rth / Re Ratio and Rth / Re Ratio

[1] After slitting both ends of the film forming film by 5 cm, 20 points were sampled (a square of 3 cm x 3 cm) at equal intervals over the entire width. At this time, each side of the square was cut out in parallel in MD (film forming direction) and TD (width direction).

[2] After adjusting the sample film to 25 ° C and 60% relative humidity for 5 hours or more, a relative birefringence meter (KOBRA-21ADH: Ojikei Sokukiki Co., Ltd.) was used at a relative humidity of 25 ° C and 60%. As described above, the retardation value at a wavelength of 550 nm was measured from the direction in which the sample film surface was inclined by 10 ° from the normal direction and the film plane normal to ± 50 °.

[3] The retardation Rth in the thickness direction was calculated from the in-plane retardation Re, the vertical direction, and measured values in the ± 10 ° to 40 ° direction from the vertical (normal) direction.

[4] The average value of the Rth / Re ratios of these measurement points was defined as the "Re / Rth ratio". In addition, the difference between the maximum value and the minimum value among the Rth / Re ratios of 20 points was defined as the "Rth / Re ratio range".

(2) Heat dimension change, heat dimension change unevenness

[1] The full width of the following sample is sampled at five points.

A) MD sample: MD 15 cm x TD 5 cm

B) TD sample: TD 15 cm × MD 5 cm

[2] Humidity was controlled at 25 ° C. and 60% rh for at least 3 hours, and measured in this environment using a 10 cm long pin gauge. Let this be L1.

[3] After each sample is left at 80 ° C. and dry for 200 hours, humidity is controlled at 25 ° C. and 60% rh for at least 3 hours and measured in this environment using a 10 cm long pin gauge. Let this be L2.

[4] The thermal dimension change at each point (10 points) of MD and TD is measured from the following equation, and this average value is referred to as the thermal dimension change.

Heat dimension change (%) = 100 × │L2-L1│ / L1

[5] The difference between the maximum value and the minimum value of the change in the thermal dimension (absolute value) in the ten points was divided by the average value of the change in the thermal dimension in the ten points and expressed as a percentage.

(3) surface roughness

Ra was measured using a compact laser interferometer (F601 manufactured by Fujishashin Koki Co., Ltd.).

(4) glass transition temperature (Tg)

20 mg of the sample was placed in a measuring pan of a scanning differential calorimeter (DSC). It heated up from 30 degreeC to 250 degreeC at 10 degreeC / min in nitrogen stream (1st-run), and cooled to -10 degreeC / min to 30 degreeC. Thereafter, the temperature was further increased from 30 ° C to 250 ° C (2nd-run). The temperature at which the baseline starts to be removed from the low temperature side in 2nd-run was defined as the glass transition temperature (Tg).

(Example)

Hereinafter, the features of the present invention will be described in more detail with reference to Examples. The materials, the amounts used, the ratios, the treatment contents, the treatment sequences, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the specific example shown below.

The brand name [TOPAS grade 6013Tg makes 139 degreeC] by the TICONA company were dried at 110 degreeC for 4 hours by the dehumidification dryer (dew point -40 degreeC), and made water content in resin into 30 ppm or less. Nichiyu Corporation Nistar H476 (pentaerythritol tetrastearate melting point 63 degreeC) or Unistar H476D (pentaerythritol distearate melting point 53 degreeC) and Irganox 1010 (radical trap agent melting point) made by Nichiyu Corporation 115 degreeC) was mixed so that it might become the quantity shown in the table of FIG. 3, and uniform mixing was performed, heating a pellet at the temperature shown in the table of FIG. 3 using a heating tumbler. The mixed heated pellets were plasticized using a φ100 mm single screw extruder (L / D = 30 compression ratio 2.0), extruded from a T die, and a film was formed by a touch roll film formation using a φ300 mm metal elastic roll. . Film film-forming was performed so that it might become thickness shown in the table | surface of FIG. Film formation was performed at the cylinder set temperature of 260 degreeC, discharge amount 150 kg / hour, roll temperature 130 degreeC in the atmosphere of the oxygen concentration of a cylinder part, and the mesh size 5 micron leaf disc filter was used for foreign material filtration.

Further, Examples 23 and 24 were calcined using a biaxial coaxial rotary extruder (φ45 L / D = 35 two vent type) having a cylinder set temperature of 260 ° C. with 0.05% of Irganox 1010 applied to TOPAS grade 6013. The pellets were pressed, extruded from the die head, and annular pellets were produced by hot cutting or underwater cutting. Nistar Oil Corporation Nistar H476 (pentaerythritol tetrastearate melting point 63 ° C) or Unistar H476D (Pentaerythritol distearate melting point 53 ° C) and Irganox 1010 (radical trap agent melting point) 115 degreeC) was mixed so that the quantity combined with the quantity used for pelletization might become the quantity shown in the table of FIG. 3, and uniform mixing was performed, heating a pellet at the temperature shown in the table of FIG. 3 using a heating tumbler. The same film formation was performed using this pellet.

Test conditions and results are shown in Table 1 of FIG. 3.

In addition, the film forming property is evaluated in that the raw materials can be supplied with the raw materials without blocking between the raw materials and the raw materials are stably supplied by vibrating devices. (Triangle | delta) and the state which resin blocked and were not supplied to the state which blocking rarely generate | occur | produced even if it improved with (circle) and a vibration apparatus etc. were made into x. Evaluation of the film haze made (circle) and 2.0% or more into (circle), 1.0% or more and less than 2.0% of (circle), and 0.7% or more and less than 1.0% of (circle) and less than 0.7% by the measurement by ASTMD-1003 method. As for the evaluation of slipperiness | lubricacy, as a result of the static friction measurement by the ASTM D-1894 method, less than 0.7 (circle), 0.7 or more and less than 0.8, (circle) and 0.8 or more and less than 1.0 and (triangle | delta) and 1.0 or more were made into x. In addition, all items have ◎, ◎, at least one item other than ◎ and ◎, but all items have good processing aptitude and physical properties. (Triangle | delta) and what has × as one item were made into what was.

As can be seen from Table 1, 0.01 to 3.0 wt% of a lubricant in a liquid state below the glass transition temperature of a lubricant or a lubricant having a melting point below the glass transition temperature of the pellet, 0.01 to 0.5 wt% of a thermal stabilizer, and The cycloolefin-based resin film formed by mixing pellets heated at a glass transition temperature (Tg) to Tg + 40 ° C. and plasticizing the mixed mixture under an oxygen concentration of 0.1% or more has a circular equivalent diameter of 0.5 or more and a circular diameter of 0.5 or more. It is understood that gels having a size of not less than 3 µm and not more than 3 µm are contained at 50 to 2000 particles / mm 2, and the gels having a circular equivalent diameter of 10 µm or more having a circularity of 0.7 or more are 10 particles / mm 2 or less.

And a cyclo-containing gel having a circular equivalent diameter of 0.7 or more and a diameter of 0.5 µm or more and 3 µm or less at 50 to 2000 pieces / mm 2, and having a circular equivalent diameter of 0.7 or more and a gel having a circular equivalent diameter of 10 μm or more and 10 or less mm 2 or less. It is understood that the overall evaluation is Δ or higher for the film formation of the olefin resin film.

Therefore, according to the present invention in the melt film forming of the cycloolefin-based resin film from the above experiments 1 to 29 according to the present invention, it is possible to suppress the deterioration of the optical properties due to the generation of the gel, and to slip on the cooling drum to deteriorate the quality of the high-quality cyclone. It turns out that an olefin resin film can be obtained.

Claims (9)

50-2000 pieces / mm2 of gels having a circular equivalent diameter of 0.5 µm or more and 3 µm or less having a circularity of 0.7 or more, and gels having a circular equivalent diameter of 10 µm or more having a circular degree of 0.7 or more are 10 / mm2 or less. Cycloolefin resin film made into As a manufacturing method of the cycloolefin resin film which melts and forms a cycloolefin resin: 0.01 to 3.0 wt% of a lubricant having a melting point of less than or equal to the glass transition temperature of the pellet or a liquid in a liquid state below the glass transition temperature of the pellet; Heat stabilizer 0.01-0.5 wt%; And Pellets containing the cycloolefin-based resin heated to a glass transition temperature (Tg) ~ Tg + 40 ° C are mixed, A method for producing a cycloolefin resin film, wherein the mixed mixture is plasticized in an atmosphere having an oxygen concentration of 0.1% or more and 10% or less. The method for producing a cycloolefin-based resin film according to claim 2, wherein the pellet is a cyclic pellet without an angle. The method for producing a cycloolefin-based resin film according to claim 3, wherein the angular pellets without angle are pellets cut by hot cutting and underwater cutting. The said norbornene-type resin is a glass transition temperature (Tg) of 120 degreeC or more, The manufacturing method of the cycloolefin resin film in any one of Claims 2-4 characterized by the above-mentioned. The manufacturing method of the cycloolefin resin film in any one of Claims 2-5 which formed into a film by the touch roll method. The film thickness is the range of 20-300 micrometers, The manufacturing method of the cycloolefin resin film in any one of Claims 2-6 characterized by the above-mentioned. Cycloolefin resin of Claim 1 is norbornene-type resin, The cycloolefin resin film characterized by the above-mentioned. The said cycloolefin resin is norbornene-type resin, The manufacturing method of the cycloolefin resin film in any one of Claims 2-7 characterized by the above-mentioned.