JP5028901B2 - Cyclic olefin-based resin composition, optical film and retardation plate using the composition, and methods for producing the same - Google Patents

Description

  The present invention relates to a cyclic olefin-based resin composition, an optical film and a retardation plate using the composition, and methods for producing them. Specifically, the present invention contains a cyclic olefin containing a large number of structural units having a dicyclopentadiene skeleton and a cyclic olefin in which the content of structural units having a dicyclopentadiene skeleton is a certain amount or less, and has excellent filtration characteristics. The present invention relates to a cyclic olefin resin composition. The present invention also relates to an optical film, a phase difference plate and a method for producing them using such a resin composition.

  The cyclic olefin ring-opening (co) polymer has a high glass transition temperature due to the rigidity of the main chain structure, and is amorphous and has a high light transmittance due to the presence of bulky groups in the main chain structure. In addition, it has features such as low birefringence due to its low refraction anisotropy, and has attracted attention as a transparent thermoplastic resin excellent in heat resistance, transparency and optical properties. Examples of such cyclic olefin-based ring-opening (co) polymers include those described in Patent Documents 1 to 6.

  In recent years, using the above-mentioned features, for example, in the fields of optical materials such as optical disks, optical lenses, optical fibers, sealing materials such as optical semiconductor sealing, and the like, cyclic olefin ring-opening (co) polymers have been applied. Is being considered. In addition, attempts have been made to improve the problems of conventional optical films by applying to films or sheets (hereinafter referred to as films including sheets).

  In other words, films such as polycarbonate, polyester, and triacetyl acetate that have been used as optical films in the past have a large photoelastic coefficient. In order to solve these problems, films made of cyclic olefin-based ring-opening (co) polymers have been proposed as various optical films. Examples of such applications include retardation films, protective films for polarizing plates, substrates for liquid crystal display elements, and the like.

  By the way, in recent years, with the increase in size and functionality of liquid crystal display elements (LCDs), the required characteristics for retardation plates used in LCDs have become more sophisticated. Therefore, higher levels of uniformity and no optical axis blur are required, and control of the phase difference in the thickness direction is required to improve the viewing angle of LCDs. Therefore, in order to meet these requirements, ring-opening homopolymers (homopolymers) and ring-opening copolymers of various cyclic olefin monomers have been proposed as materials for retardation plates.

  However, in the case of a homopolymer, the characteristics of the polymer obtained are uniquely determined by the characteristics of the cyclic olefin monomer used, and there is a limit to responding to all the various required characteristics.

  On the other hand, in the case of a copolymer, stretching near the glass transition temperature (hereinafter also referred to as Tg) of the copolymer may cause the film after stretching to become cloudy or reduce the uniformity of retardation. Serious problems may occur. Of course, these problems can be avoided by increasing the film stretching temperature and stretching, but the stretching ratio for obtaining a desired retardation value decreases because the retardation develops when stretched at a high temperature. There is a problem in controlling the retardation value, such as increasing the film thickness or increasing the film thickness.

  Therefore, it has excellent properties of cyclic olefin resins such as heat resistance and transparency, and also causes problems such as cloudiness even when film forming or film stretching is performed at a relatively low temperature such as near Tg. However, a resin suitable for applications such as a retardation plate has been strongly desired.

In such a situation, the applicant of the present application has obtained a cyclic olefin having a polar group and a hydrocarbon group and tricyclo [4.3.0.1 ^2,5 ] dec-3-ene (which may have a substituent). A cyclic olefin-based ring-opening copolymer obtained from dihydrodicyclopentadiene) and a cyclic olefin having no polar group, such as bicyclo [2.2.1] hept-2-ene, under temperature conditions near Tg. It has been found that it does not cause problems such as white turbidity even when stretched and is suitable for the use of a film or sheet and a retardation plate (Japanese Patent Application No. 2005-213011).

  However, when a polymer obtained by ring-opening (co) polymerization of a cyclic olefin having a dihydrodicyclopentadiene skeleton is formed by a solution casting method, a gel is likely to be formed. There was a problem that the surface properties were inferior.

For this reason, using a cyclic olefin-based ring-opening copolymer having a structural unit derived from dihydrodicyclopentadiene, filtration is performed without any gelation problem, and it is used for the solution casting method and has excellent surface smoothness. The advent of technology for obtaining films has been strongly desired.
Japanese Patent Laid-Open No. 1-132625 JP-A-1-132626 JP 63-218726 A JP-A-2-133413 JP 61-120816 A Japanese Patent Laid-Open No. 61-115912

The present invention relates to a structural unit derived from a cyclic olefin having a polar group and a hydrocarbon group, and tricyclo [4.3.0.1 ^2,5 ] dec-3-ene which may have a substituent. An object of the present invention is to provide a technique for obtaining an optical film excellent in surface smoothness by performing filtration without using a cyclic olefin-based ring-opening copolymer and subjecting it to a solution casting method. That is, the present invention provides a resin composition containing the cyclic olefin-based ring-opening copolymer, hardly causing gelation, excellent in filtration performance, and suitably used for the production of optical films and retardation plates, It is an object to provide an optical film and a retardation plate using the resin composition, and to provide a method for producing an optical film or a retardation plate excellent in surface smoothness using the resin composition. Yes.

The resin composition of the present invention is
(A) 50 to 95% by weight of the structural unit (1) represented by the following formula (1),
Copolymer (A) having 5 to 50% by weight of structural unit (2) represented by the following formula (2) (however, the total amount of structural unit (1) and structural unit (2) is 100% by weight) ); 10-99 parts by weight;
(B) 70-95 weight% of structural units (1) represented by the following formula (1)
0 to 10% by weight of the structural unit (2) represented by the following formula (2),
Copolymer (B) having 5 to 20% by weight of structural unit (3) represented by the following formula (3) (however, the total amount of structural unit (1), structural unit (2) and structural unit (3)) 1 to 90 parts by weight).

(In formula (1), m is 0, 1 or 2, X is independently a group represented by the formula: —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —, R ^{1 to} R ⁴ are each independently a hydrogen atom; a halogen atom; a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon; or Represents a polar group, provided that at least one of R ^{1 to} R ⁴ is a polar group and at least one of the other R ^{1 to} R ⁴ is a hydrocarbon group having 1 to 10 carbon atoms.)

(In formula (2), X is independently a group represented by the formula: —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —, and R ^{5 to} R ¹⁰ are each independently hydrogen. An atom; a halogen atom; a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon; or a polar group.

(In the formula (3), n is 0, 1 or 2, X is independently a group represented by the formula: —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —, R ^{11 to} R ¹⁴ are each independently a hydrogen atom; a halogen atom; or a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon Represents.)
In such a resin composition of the present invention, the structural unit (1) in the copolymers (A) and (B) preferably has a group represented by the following formula (4) as a polar group.

− (CH ₂ ) _p COOR ′ (4)
(In Formula (4), p is 0 or an integer of 1 to 5, and R ′ is a hydrocarbon group having 1 to 15 carbon atoms.)
The optical film of the present invention is characterized by containing the resin composition of the present invention.

The retardation plate of the present invention is characterized by being formed by stretching and orientation of an unstretched film containing the resin composition of the present invention.
The method for producing an optical film of the present invention is characterized in that the resin composition of the present invention is formed by a solution casting method. The method for producing a retardation plate of the present invention is characterized in that the optical film obtained by the method of the present invention is stretched and oriented under a temperature condition of Tg to (Tg + 10) ° C. of the optical film.

The method for producing a retardation plate of the present invention comprises an unstretched film containing the resin composition of the present invention,
The film is stretched and oriented under a temperature condition of Tg to (Tg + 10) ° C.

According to the present invention, a structure derived from a cyclic olefin having a polar group and a hydrocarbon group and tricyclo [4.3.0.1 ^2,5 ] dec-3-ene which may have a substituent. The resin composition which contains the cyclic olefin type ring-opening copolymer which has a unit, does not produce gelation easily, is excellent in filtration performance, and can be used suitably for manufacture of an optical film and a phase difference plate can be provided. In addition, according to the present invention, an optical film excellent in surface smoothness using the resin composition and a retardation film are provided, and an optical film excellent in surface smoothness using the resin composition or A method of manufacturing a retardation film can be provided. The optical film according to the present invention is excellent in heat resistance, chemical resistance, etc., and can be stretched without causing problems such as white turbidity even at a relatively low temperature near the glass transition temperature, when a retardation plate is formed. Indicates a uniform phase difference and little optical axis shake.

Hereinafter, the present invention will be specifically described.
Resin composition The resin composition of the present invention comprises:
(A) 50 to 95% by weight of the structural unit (1) represented by the above formula (1),
Copolymer (A) having 5 to 50% by weight of the structural unit (2) represented by the above formula (2) (however, the total amount of the structural unit (1) and the structural unit (2) is 100% by weight) ); 10-99 parts by weight;
(B) 70 to 95% by weight of the structural unit (1) represented by the above formula (1)
0 to 10% by weight of the structural unit (2) represented by the above formula (2),
Copolymer (B) having 5 to 20% by weight of the structural unit (3) represented by the above formula (3) (however, the total amount of the structural unit (1), the structural unit (2) and the structural unit (3)) 1 to 90 parts by weight.
<Copolymer (A) / Copolymer (B)>
The copolymer (A) according to the present invention comprises 50 to 95% by weight, preferably 60 to 70% by weight of the structural unit (1) represented by the above formula (1).
A cyclic olefin ring-opening copolymer having 5 to 50% by weight, preferably 15 to 30% by weight, of the structural unit (2) represented by the above formula (2). (However, the total amount of the structural unit (1) and the structural unit (2) is 100% by weight)
The structural unit (1) is derived from a cyclic olefin monomer (1m) represented by the following formula (1m) by ring-opening copolymerization.

In the formula (1m), m and R ^{1 to} R ⁴ are the same as those in the formula (1). That is, m is 0, 1 or 2, X is independently a group represented by the formula: —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —, and R ^{1 to} R ⁴ Each independently represents a hydrogen atom; a halogen atom; a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon; or a polar group. However, at least one of R ^{1 to} R ⁴ is a polar group, and at least one of the other R ^{1 to} R ⁴ is a hydrocarbon group having 1 to 10 carbon atoms.

  In the formula (1) or (1m), examples of the polar group include a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, a carbonyloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, a cyano group, an amide group, and an imide group. , Triorganosiloxy group, triorganosilyl group, amino group, acyl group, alkoxysilyl group, sulfonyl group, carboxyl group and the like. More specifically, examples of the alkoxy group include a methoxy group and an ethoxy group; examples of the carbonyloxy group include an alkylcarbonyloxy group such as an acetoxy group and a propionyloxy group, and an aryl such as a benzoyloxy group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group; examples of the aryloxycarbonyl group include a phenoxycarbonyl group, a naphthyloxycarbonyl group, a fluorenyloxycarbonyl group, Biphenylyloxycarbonyl group and the like; examples of the triorganosiloxy group include trimethylsiloxy group and triethylsiloxy group; examples of the triorganosilyl group include trimethylsilyl group, Such Riechirushiriru group and the like; examples of the amino group include primary amino group, the alkoxysilyl group, for example trimethoxysilyl groups, such as triethoxysilyl group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.
Examples of the hydrocarbon group having 1 to 10 carbon atoms include alkyl groups such as methyl group, ethyl group, and propyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; alkenyl groups such as vinyl group, allyl group, and propenyl group. Group and the like.

The substituted or unsubstituted hydrocarbon group may be directly bonded to the ring structure, or may be bonded via a linkage. As the linking group, for example, from 1 to 1 carbon atoms
A divalent hydrocarbon group of 10 (for example, an alkylene group represented by — (CH ₂ ) _m — (wherein m is an integer of 1 to 10)); a linking group containing oxygen, nitrogen, sulfur or silicon ( For example, a carbonyl group (—CO—), an oxycarbonyl group (—O (CO) —), a sulfone group (—SO ₂ —), an ether bond (—O—), a thioether bond (—S—), an imino group ( -NH-), amide bond (-N
HCO-, -CONH-), a siloxane bond (-OSi (R ₂ )-(wherein R is an alkyl group such as methyl, ethyl)) and the like, and a linking group containing a plurality of these may be used. .

Examples of these groups are the same for formulas (2), (2m), (3), and (3m) described later.
As such a cyclic olefin monomer (1m), specifically, for example,
5-methyl-5-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene,
5-methyl-5-phenoxycarbonyl-bicyclo [2.2.1] hept-2-ene,
5-methyl-6-methoxycarbonyl-bicyclo [2.2.1] hept-2-ene,
5-methyl-6-phenoxycarbonyl-bicyclo [2.2.1] hept-2-ene,
8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8-ethoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8-n-propoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene,
8-methyl-8-isopropoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene,
8-methyl-8-n-butoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10
] Dodec-3-ene,
8-methyl-8-phenoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ]
Although dodec-3-ene etc. can be mentioned, it is not limited to these illustrations.

Here, in the structural unit (1) and the cyclic olefin monomer (1m), the polar group is preferably a group represented by the following formula (4). That is, it is preferable that at least one of R ^{1 to} R ^{4 in} the formula (1) or (1m) is a group represented by the following formula (4).

− (CH ₂ ) _p COOR ′ (4)
(In Formula (4), p is 0 or an integer of 1 to 5, and R ′ is a hydrocarbon group having 1 to 15 carbon atoms.)
In the above formula (4), the smaller the value of p and the smaller the R ′ carbon number, the higher the glass transition temperature of the resulting copolymer and the better the heat resistance. That is, p is usually 0 or an integer of 1 to 5, preferably 0 or 1, and R 'is usually a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 3 carbon atoms. It is desirable that it is an alkyl group.

  When the polar group has the structural unit (1) which is a group represented by the above formula (4), it is preferable because the heat resistance and water absorption (wet) property of the copolymer are excellent in balance. The number of carbon atoms of the alkyl group further bonded to the carbon atom to which the polar group represented by the above formula (4) is bonded is preferably 1 to 5, more preferably 1 to 2, particularly preferably 1. is there.

  The structural unit (2) is derived from a cyclic olefin monomer (2m) represented by the following formula (2m) by ring-opening copolymerization.

In formula (2m), R ^{5 to} R ¹⁰ are as defined in formula (2). That is, R ^{5 to} R ¹⁰ are each independently a hydrogen atom; a halogen atom; a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon. Or represents a polar group.

Specific examples of such a cyclic olefin monomer (2m) include, for example, tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-methyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
8-methyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-ethyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-isopropyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-cyclohexyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-phenyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7,7-dimethyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7,8-dimethyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-methyl-8-ethyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-methoxycarbonyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
8-methoxycarbonyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-phenoxycarbonyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-methyl-7-methoxycarbonyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
8-methyl-8-methoxycarbonyl-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-fluoro-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
8-fluoro-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7-chloro-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
8-chloro-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7,7-difluoro-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7,8-difluoro-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene,
7,8-Dichloro-tricyclo [4.3.0.1 ^2,5 ] dec-3-ene and the like can be mentioned, but are not limited to these examples.

  The structural unit (2) may be derived from a cyclic olefin monomer (2m ′) represented by the following formula (2m ′) by ring-opening polymerization and hydrogenation of a five-membered ring.

(In the formula (2m ′), R ⁵ , R ⁶ , R ⁷ and R ⁹ are as defined in the formula (2).)
As such a cyclic olefin monomer (2m ′), specifically, for example, tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene (DCP),
7-methyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene,
8-methyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene,
9-methyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene,
7,8-dimethyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene,
7-ethyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene,
7-cyclohexyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene;
7-phenyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene,
7- (4-biphenyl) -tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene 7-methoxycarbonyl-tricyclo [4.3.0.1 ^2,5 ] deca-3, 7-diene,
7-phenoxycarbonyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene;
7-Methyl-7-methoxycarbonyl-tricyclo [4.3.0.1 ^2,5 ] deca-3,7
-Diene,
7-fluoro-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene,
7,8-difluoro-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene,
Examples thereof include 7-chloro-tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene, but are not limited to these examples. Of these, tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene is particularly preferably used in the present invention.

  The copolymer (A) according to the present invention may be a copolymer composed only of the structural unit (1) and the structural unit (2) described above, but does not impair the object of the present invention, if necessary. In the range, it may have a structural unit (3) constituting the copolymer (B) described later, or may have a structural unit derived from another copolymerizable monomer. As the structural unit derived from the other copolymerizable monomer, a structural unit derived by ring-opening copolymerization of a cyclic olefin monomer having a norbornene skeleton other than the structural unit (1) or (2) is preferable. In addition, structural units derived from ring-opening copolymerization of cycloolefin monomers such as cyclobutene, cyclopentene, cycloheptene, and cyclooctene, polybutadiene, polyisoprene, styrene-butadiene copolymer, ethylene-non Examples thereof include a structural unit derived by copolymerizing an unsaturated hydrocarbon polymer having an olefinically unsaturated bond in the main chain such as a conjugated diene copolymer and polynorbornene.

  Such a copolymer (A) is obtained by ring-opening copolymerization of the monomer (1m), the monomer (2m) or (2m ′), and other monomers as necessary. Preferably, it can be produced by hydrogenation.

  As the molecular weight of the copolymer (A) used in the present invention, the number average molecular weight (Mn) in terms of polystyrene measured by gel permeation chromatography (GPC) is usually 8000 to 1,000,000, preferably 10 The weight average molecular weight (Mw) in terms of polystyrene is usually 10,000 to 3,000,000, preferably 20,000 to 10,000,000 to 500,000, more preferably 10,000 to 100,000. It is desirable that it is in the range of 1,000,000, more preferably 30,000 to 500,000.

  When the molecular weight is too small, the strength of the obtained film may be low. On the other hand, when the molecular weight is excessive, the solution viscosity becomes too high, and the productivity and processability of the copolymer of the present invention may deteriorate.

The molecular weight distribution (Mw / Mn) of the copolymer (A) used in the present invention is usually 1.5 to 10, preferably 2 to 8, and more preferably 2.2 to 5.
It is preferable that the glass transition temperature (Tg) of the copolymer (A) used by this invention is 110 degreeC or more, More preferably, it is 110-250 degreeC, More preferably, it is 115-220 degreeC, Most preferably, it is 120. ~ 200 ° C. A Tg of 110 ° C. or higher is preferable because of excellent heat resistance. When Tg is less than 110 ° C., the heat distortion temperature becomes low, which may cause a problem in heat resistance, and there may be a problem that a change in optical properties due to temperature in the obtained film becomes large. is there. On the other hand, when Tg exceeds 250 ° C., the processing temperature becomes too high during the drawing process, and the copolymer of the present invention may be thermally deteriorated.

  When such a copolymer (A) is used, a resin composition suitable for applications such as an optical film and a phase difference plate can be obtained. In the present invention, when the copolymer (A) contains the structural unit (2) in the above-described amount, a high retardation is produced when a stretched film is produced from the resin composition of the present invention containing the structural unit (2). Expression is obtained.

In the copolymer (B) according to the present invention, the structural unit represented by the above formula (1) is 70 to 95% by weight, preferably 80 to 95% by weight, and the structural unit represented by the above formula (2) ( 2) 0-10% by weight, preferably 0% by weight;
A cyclic olefin ring-opening copolymer having 5 to 20% by weight, preferably 5 to 15% by weight, of the structural unit (3) represented by the above formula (3). (However, the total amount of the structural unit (1), the structural unit (2) and the structural unit (3) is 100% by weight)
Here, the structural units (1) and (2) are as described above for the copolymer (A).

  The structural unit (3) is derived from a cyclic olefin monomer (3m) represented by the following formula (3m) by ring-opening copolymerization.

In the formula (3m), n and R ^{11 to} R ¹⁴ are the same as those in the formula (3). That is, n is 0, 1 or 2, and R ^{11 to} R ¹⁴ are each independently a hydrogen atom; a halogen atom; or a substituted or non-substituted group optionally having a linking group containing oxygen, nitrogen, sulfur or silicon. A substituted hydrocarbon group having 1 to 10 carbon atoms is represented.

Specific examples of the cyclic olefin monomer (3m) include bicyclo [2.2.1] hept-2-ene,
Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene,
Hexacyclo [6.6.1.1 ^3,6 . 1 ^10,13 . 0 ^2,7 . 0 ^9,14 ] hept-4-ene 5-ethyl-bicyclo [2.2.1] hept-2-ene,
Examples include 5-methyl-bicyclo [2.2.1] hept-2-ene, but are not limited to these examples. Of these, bicyclo [2.2.1] hept-2-ene is particularly preferably used in the present invention.

  The copolymer (B) used in the present invention is composed of the monomer (1m), the monomer (3m), and other monomers (2m) and the copolymer (A) as described above, if necessary. It can be produced by using a monomer in the same manner as described above for the copolymer (A) by ring-opening copolymerization and, if necessary, hydrogenation.

It is more preferable that such a copolymer (B) has only the structural units (1) and (3).
The copolymer (B) according to the present invention has excellent compatibility with the copolymer (A) by containing the structural unit (3). When the content of the structural unit (C) in the copolymer (B) exceeds the above-described range, the solubility in a solvent is lowered, which is not preferable.

  Although each structural unit which comprises a copolymer (B) is not specifically limited, It is preferable that the structural unit of the kind similar to each structural unit which comprises a copolymer (A) is included, It is particularly preferred that it contains a structural unit. The copolymer (B) having such a structural unit is particularly excellent in compatibility with the copolymer (A), and molded articles such as optical films and retardation plates obtained from a resin composition using the copolymer (A) can be obtained. Since it becomes a high quality thing, it is preferable.

  Although the copolymer (B) used by this invention is not specifically limited, It is desirable for a glass transition temperature (Tg) to be in the range of 90-170 degreeC normally, Preferably it is 110-150 degreeC. The glass transition temperature (Tg) of the copolymer (B) is desirably within ± 20 ° C., preferably within ± 10 ° C., with respect to the Tg of the copolymer (A).

The copolymer (B) used in the present invention preferably has a DSC differential differential scanning calorimetry curve that exhibits a single peak.
Furthermore, the copolymer (B) used in the present invention has a number average molecular weight measured by gel permeation chromatography (GPC) (5000 to 500,000), preferably (1000 to 20000), Further, it is desirable that the molecular weight distribution (Mw / Mn) is in the range of (2-5), preferably (3-4.5).

  The copolymers (A) and (B) used in the present invention have a saturated water absorption at 23 ° C. of usually 0.01 to 1% by weight, preferably 0.05 to 0.7% by weight, more preferably 0.8. It is desirable to be 1 to 0.5% by weight. If the saturated water absorption rate of the cyclic olefin polymer used in the present invention is within the above range, various optical properties, transparency, retardation and retardation uniformity, or dimensional accuracy of the obtained film are high temperature and high humidity. In addition to being stably maintained even under such conditions, it is excellent in adhesion and adhesion with other materials, so that peeling does not occur during use, and with additives such as antioxidants Since compatibility is also good, the freedom degree of selection of the kind and addition amount of an additive becomes large.

  When this saturated water absorption is less than 0.01% by weight, the resulting film has low adhesion and adhesiveness to other materials, tends to cause peeling during use, and an antioxidant. The amount of additives such as these may be limited. On the other hand, when the saturated water absorption exceeds 1% by weight, the water absorption tends to cause changes in optical characteristics and dimensional changes.

Here, the saturated water absorption is a value obtained by immersing in water at 23 ° C. for 1 week and measuring an increased weight in accordance with ASTM D570.
The copolymers (A) and (B) have a DSC differential differential scanning calorimetry curve showing a single peak, and a Tg distribution which is the rising temperature width of the peak is 40 ° C. or less, preferably 35 ° C. or less. It is preferable to have a narrow distribution. The differential scanning calorimetric curve of DSC used in the present invention is obtained when measured in a nitrogen atmosphere at a heating rate of 20 ° C./min. The peak rising temperature width is the width between the inflection points where the peak rises from the baseline. Furthermore, the Tg of the cyclic olefin-based ring-opening copolymer is plotted on the differential scanning calorimetry curve with the maximum differential peak temperature (point A) of differential differential scanning calorific value and the temperature (point B) of −20 ° C. from the maximum peak temperature. , And the intersection of the tangent line on the baseline starting from point B and the tangent line starting from point A.

Next, a method for producing the copolymers (A) and (B) will be described.
The copolymerization of each monomer described above can be performed by appropriately selecting the polymerization conditions in consideration of the reactivity of each monomer used. During copolymerization, it is preferable that the monomer composition ratio in the polymerization system does not change significantly between the initial and late stages of polymerization, and when the monomer concentration changes over time, the polymerization is stopped at an early stage. Alternatively, it is preferable to keep the monomer composition ratio constant by supplying the monomer having a reduced concentration into the polymerization system continuously or intermittently into the polymerization system. When copolymerization is performed while controlling the monomer composition ratio in this way, a copolymer capable of forming an optical film excellent in transparency can be obtained.

As a catalyst for ring-opening polymerization that can be suitably used for producing the copolymers (A) and (B) used in the present invention, for example,
(I) A catalyst described in Olefin Metathesis and Metathesis Polymerization (KJIVIN, JCMOL, Academic Press 1997) is preferably used. Examples of such a catalyst include (a) at least one selected from compounds of W, Mo, Re, V and Ti, and (b) an alkali metal element (for example, Li, Na, K), alkaline earth. Group metal elements (eg, Mg, Ca), Group 12 elements (eg, Zn, Cd, Hg), Group 13 elements (eg, B, Al), Group 14 elements (eg, Si, Sn, Pd) And a metathesis catalyst comprising a combination with at least one selected from those having at least one of the element-carbon bond or the element-hydrogen bond. In order to enhance the activity of the catalyst, the additive (c) described later may be added.

Specific examples of the component (a) include compounds described in JP-A-1-240517 such as WCl ₆ , MoCl ₅ , ReOCl ₃ , VOCl ₃ , TiCl _{4 and the} like. These can be used singly or in combination of two or more.

Specific examples of the component (b), for _{example, n-C 4 H 9 Li} , (C 2 H 5) 3 Al, (C 2 H 5) 2 AlCl, (C 2 H 5) 1.5 AlCl 1 _0.5 , (C ₂ H ₅ ) AlCl ₂ , methylalumoxane, LiH and the like, compounds described in JP-A-1-240517 can be mentioned. These can be used singly or in combination of two or more.

  As the additive for the component (c), for example, alcohols, aldehydes, ketones, amines and the like can be preferably used, and further, compounds described in JP-A-1-240517 can be used. Can do. These can be used singly or in combination of two or more.

  The amount of the metathesis catalyst formed by combining the above component (a) is such that the molar ratio of “component (a): total monomer” between the component (a) and the total monomer is usually 1 : 500 to 1: 500,000, preferably 1: 1,000 to 1: 100,000. Further, the ratio of the component (a) to the component (b) is such that the metal atom (mole) ratio of “(a) :( b)” is usually 1: 1 to 1:50, preferably 1: 2. It is in the range of ˜1: 30. When the additive (c) is added to the metathesis catalyst, the ratio of the component (a) to the component (c) is such that the molar ratio of “(c) :( a)” is usually 0.005: 1 to The range is 15: 1, preferably 0.05: 1 to 7: 1.

As other catalysts,
(II) A metathesis catalyst composed of a transition metal-carbene complex or a metallacyclobutane complex of Groups 4 to 8 of the periodic table can be used.

Specific examples of the catalyst (II), for _{^{example, W (= N-2,6-}} C 6 H 3 i Pr 2) (= CH t Bu) (O t Bu) 2, Mo (= N-2, _{^{6-C 6 H 3 i Pr}} 2) (= CH t Bu) (O t Bu) 2, Ru (= CHCH = CPh 2) (PPh 3) 2 Cl 2, Ru (= CHPh 2) [P (C 6 H ₁₁ ) ₃ ] ₂ Cl _{2 and the} like. These can be used singly or in combination of two or more.

  The amount of the catalyst (II) used is such that the molar ratio of “catalyst (II): total monomer” is usually 1: 500 to 1: 50,000, preferably 1: 100 to 1:10, 000.

The catalysts (I) and (II) may be used in combination.
The molecular weights of the copolymers (A) and (B) used in the present invention can also be adjusted by adjusting the polymerization temperature, the type of catalyst, the type of solvent, etc. It is preferable to adjust by making it coexist in the polymerization reaction system. As the molecular weight regulator, for example, ethylene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and other α-olefins and styrene are preferable. Of these, 1-butene and 1-hexene are particularly preferred. These molecular weight regulators can be used singly or in combination of two or more. The amount used of the molecular weight regulator is usually 0.005 to 0.6 mol, preferably 0.02 to 1 mol per mol of all monomers.
0.5 mole.

  Examples of the solvent used in the ring-opening copolymerization reaction (that is, a solvent that dissolves a monomer, a ring-opening polymerization catalyst, a molecular weight regulator, etc.) include alkanes such as pentane, hexane, heptane, octane, nonane, and decane. ; Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; chlorobutane, bromohexane, methylene chloride, dichloroethane, hexamethylene dibromide, chlorobenzene , Compounds such as halogenated alkanes such as chloroform and tetrachloroethylene, aryl halides; saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, iso-butyl acetate and methyl propionate; dibutyl ether, tetrahydro Emissions, include ethers such as dimethoxyethane, aromatic hydrocarbons are preferred among these. These can be used singly or in combination of two or more. The use amount of the solvent for the ring-opening polymerization reaction is such that the weight ratio of “solvent: total monomer” is usually 1: 1 to 10: 1, preferably 1: 1 to 5: 1. Is desirable.

  The temperature of the monomer solution when adding the catalyst is preferably 30 to 200 ° C, more preferably 50 to 180 ° C. When the temperature is lower than 30 ° C, the yield of the polymer may be lowered, and when it exceeds 200 ° C, it may be difficult to control the molecular weight.

The reaction time for carrying out the ring copolymerization reaction is usually from 0.1 to 10 hours, preferably from 0.1 to 9 hours, more preferably from 0.1 to 8 hours.
A ring-opening copolymer obtained by ring-opening copolymerization of each cyclic olefin-based monomer has an olefinic unsaturated bond in the molecule and has problems such as heat-resistant coloring. The olefinically unsaturated bond is preferably hydrogenated, but a known method can be applied to the hydrogenation reaction. For example, the catalysts, solvents, temperature conditions, and the like described in JP-A-63-218726, JP-A-1-132626, JP-A-1-240517, JP-A-2-10221, and the like are applied. The ring-opening polymerization reaction and the hydrogenation reaction can be carried out.

The hydrogenation rate of the olefinically unsaturated bonds of the copolymers (A) and (B) is usually 80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more. In addition, as above-mentioned, the hydrogenation reaction in this invention is with respect to the olefinic unsaturated bond in a molecule | numerator, and when the cyclic olefin type polymer used by this invention has an aromatic group, the aromatic group concerned is Since it may act advantageously in optical characteristics such as refractive index and heat resistance, hydrogenation is not necessarily required.
<Resin composition>
The resin composition of the present invention comprises 10 to 99 parts by weight, preferably (30 to 90) parts by weight of the above-mentioned copolymer (A), and 1 to 40 parts by weight of the above-mentioned copolymer (B), preferably Contains (40-90) parts by weight. Such a resin composition of the present invention may contain other resin components, but it is particularly preferred that the resin component contains only the copolymer (A) and the copolymer (B).

  The resin composition according to the present invention may be used by adding additives such as known antioxidants and ultraviolet absorbers in order to improve heat deterioration resistance and light resistance within a range that does not impair the effects of the present invention. Good. For example, at least one compound selected from the group consisting of the following phenol compounds, thiol compounds, sulfide compounds, disulfide compounds, and phosphorus compounds is used with respect to 100 parts by weight of the resin component of the resin composition according to the present invention. When added in an amount of 0.01 to 10 parts by weight, the heat deterioration resistance can be improved.

  Examples of phenolic compounds include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) proonate], 1,6-hexanediol-bis [3- (3,5-di- -T-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -3,5-triazine, penta Erythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4- Hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N, N-hexamethylenebis 3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) ) Benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5- Methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, and the like. Preferably, octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,3,5-trimethyl-2,4,6-tris (3,5-di-t- Butyl-4-hydroxybenzyl) benzene, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], particularly preferably octadecyl-3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate] and the like.

  Examples of thiol compounds include alkyl mercaptans such as t-dodecyl mercaptan and hexyl mercaptan, 2-mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole, 1-methyl-2- (methylmercapto) benzimidazole, and 2-mercapto. -1-methylbenzimidazole, 2-mercapto-4-methylbenzimidazole, 2-mercapto-5-methylbenzimidazole, 2-mercapto-5,6-dimethylbenzimidazole, 2- (methylmercapto) benzimidazole, 1- Examples include methyl-2- (methylmercapto) benzimidazole, 2-mercapto-1,3-dimethylbenzimidazole, mercaptoacetic acid, and the like.

Examples of sulfide compounds include 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thiobis (4-methyl-6-t- Butylphenol), 2,4-bis (n-octylthiomethyl) -6-methylphenol, dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'- Examples thereof include thiodipropionate, pentaerythrityltetrakis (3-laurylthiopropionate), and ditridecyl 3,3′-thiodipropionate.

Disulfide compounds include bis (4-chlorophenyl) disulfide, bis (
2-chlorophenyl) disulfide, bis (2,5-dichlorophenyl) disulfide
Bis (2,4,6-trichlorophenyl) disulfide, bis (2-nitrophenyl) disulfide, ethyl 2,2'-dithiodibenzoate, bis (4-acetylphenyl) disulfide, bis (4-carbamoylphenyl) disulfide 1,1′-dinaphthyl disulfide, 2,2′-dinaphthyl disulfide, 1,2′-dinaphthyl disulfide,
2,2′-bis (1-chlorodinaphthyl) disulfide, 1,1′-bis (2-chloronaphthyl) disulfide, 2,2′-bis (1-cyanonaphthyl) disulfide, 2,2′-bis ( 1-acetylnaphthyl) disulfide, dilauryl-3,3′-thiodipropionic acid ester, and the like.

Examples of phosphorus compounds include tris (4-methoxy-3,5-diphenyl) phosphite,
Tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis ( 2,4-di-t-butylphenyl) pentaerythritol diphosphite.

  Further, benzophenone compounds such as 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone, benzotriazole compounds such as N- (benzyloxycarbonyloxy) benzotriazole, 2-ethyloxanilide, 2-ethyl By adding 0.01 to 3 parts by weight, preferably 0.05 to 2 parts by weight, based on 100 parts by weight of the copolymer of the present invention, an oxanilide-based compound such as -2'-ethoxyoxanilide, Light resistance can be improved.

In addition, these compounds which are additives may be used individually by 1 type, and may be used in combination.
Moreover, you may add another additive to the resin composition of this invention according to the characteristic of the target molded object. For example, for the purpose of obtaining a colored film, colorants such as dyes and pigments may be added, and a leveling agent may be added to improve the smoothness of the resulting film. Examples of the leveling agent include a fluorine-based nonionic surfactant, a special acrylic resin leveling agent, and a silicone leveling agent.

  In the present invention, when an additive is added to the resin composition, the additive may be added at the time of preparing the resin composition or may be added before molding. For example, when the resin composition of the present invention is dissolved in a solvent and molded by a solution casting method, an additive may be added during the preparation of the resin composition, and before the resin composition is dissolved in the solvent. It may be added, may be added before the filtration after the step of dissolving in the solvent or after the dissolution, or may be added before the film formation after the filtration.

Such a resin composition of the present invention is not particularly limited, but preferably has a logarithmic viscosity measured using a Ubbelohde viscometer at a sample concentration of 0.5 g / dL and a temperature of 30 ° C. in dichlorobenzene. Is 0.1 to 5 dL / g, more preferably 0.3 to 1 dL / g, still more preferably 0.4 to 0.7 dL / g.

  The resin composition of the present invention is excellent in retardation development, but is difficult to filter by gelation, and a ring-opening copolymer (B) excellent in compatibility with this. Including, it is difficult to cause gelation, has excellent filtration characteristics, and exhibits high retardation expression when the formed film is stretched. Moreover, since it is compatible, an optical film excellent in transparency can be obtained.

Such a resin composition of the present invention can be used for various optical applications because the molded product has excellent water resistance, heat resistance, chemical resistance, transparency and the like. Moreover, since the resin composition of this invention can be suitably shape | molded with a melt molding method, and the solution is excellent in the filtration characteristic, it is also preferable to shape | mold by the solution casting method. A film obtained using the resin composition of the present invention is suitable as an optical film. In addition, an unstretched film obtained using the resin composition of the present invention is obtained because it hardly causes white turbidity and develops a high retardation even when stretched at a relatively low temperature such as near Tg. The stretched film can be suitably used as a retardation plate.
Optical film and production thereof The optical film of the present invention contains the above-described resin composition of the present invention. In the present invention, the film is a general term for films and sheets.

The optical film of the present invention can be obtained by forming a film by a known method such as a solution casting method or a melt extrusion method using the above-described resin composition of the present invention. In the present invention, since the resin composition is excellent in filtration characteristics, it is preferable to form a film by a solution casting method.

Below, the case where the optical film of this invention is formed into a film by the solution casting method is demonstrated.
<Solution casting method>
As the solution casting method (solvent casting method), for example, a film forming liquid containing the resin composition of the present invention at an appropriate concentration is prepared by dissolving or dispersing the resin composition of the present invention in a solvent. And, if necessary, after filtration, the film-forming liquid is cast by pouring or coating on a suitable carrier, thereby forming a liquid phase of the film-forming liquid on the carrier, and then the liquid layer A preferable method is to perform a solvent removal treatment by drying or the like and peel the resulting film from the carrier.

  In the preparation of a film forming solution by the solution casting method, the concentration of the resin composition of the present invention is usually 0.1 to 70% by weight, preferably 1 to 50% by weight, more preferably 10 to 35% by weight. It is. When this concentration is too small, it becomes difficult to obtain a film having a required thickness, and when the solvent is removed by drying, foaming or the like is likely to occur with evaporation of the solvent, and surface smoothness is obtained. It may be difficult to obtain a good film. On the other hand, if this concentration is excessive, the viscosity of the film-forming solution becomes too high, and it may be difficult to obtain a film having a uniform thickness and surface condition.

  Solvents used for the preparation of the film forming liquid include aromatic solvents such as benzene, toluene and xylene, cellosolve solvents such as methyl cellosolve, ethyl cellosolve and 1-methoxy-2-propanol, diacetone alcohol, acetone and cyclohexanone. Ketone solvents such as methyl ethyl ketone, 4-methyl-2-pentanone, cyclohexanone, ethyl cyclohexanone and 1,2-dimethylcyclohexane, ester solvents such as methyl lactate and ethyl lactate, 2,2,3,3-tetrafluoro- Examples thereof include halogen-containing solvents such as 1-propanol, methylene chloride and chloroform, ether solvents such as tetrahydrofuran and dioxane, and alcohol solvents such as 1-pentanol and 1-butanol.

  In the present invention, it is desirable to use a solvent having a boiling point of 10 ° C. or higher and 150 ° C. or lower, preferably 20 ° C. or higher and 50 ° C. or lower, more preferably 30 ° C. or higher and 50 ° C. or lower as a solvent for dissolving or dispersing the resin composition.

Also in addition to the above solvent, SP value (solubility parameter) of usually 10 to 30 ^{(MPa 1/2),} preferably 10 to 25 ^{(MPa 1/2),} more preferably 15-25 ^{(MPa 1/2} ), And particularly preferably, by using a solvent in the range of 15 to 20 (MPa ^1/2 ), a film having good surface state uniformity and optical properties can be obtained.

  Said solvent can be used individually or in combination of 2 or more types. When two or more solvents are used in combination, the SP value of the obtained mixed solvent is preferably within the above range. Here, the SP value of the mixed solvent can be determined from the SP value of each solvent and the weight ratio thereof. For example, in a mixed solvent obtained from two kinds of solvents, the weight fraction of each solvent is set to W1 and When W2 is set and SP values are SP1 and SP2, the SP value of the mixed solvent can be calculated by the formula: SP value = W1 · SP1 + W2 · SP2.

The temperature at which the resin composition of the present invention is dissolved or dispersed in a solvent may be room temperature or high temperature, and by sufficiently stirring, a solution in which the resin composition of the present invention is uniformly dissolved or dispersed is obtained. Is filtered to obtain a film-forming solution. By filtering the resin composition dissolved in the solvent, a uniform filtrate that does not partially contain a gel can be prepared. In the present invention, this is preferably used as a film-forming solution. Use of such a film-forming liquid is preferable because the resulting film does not contain foreign substances or does not partially become thick and has excellent surface smoothness.

  Filtration of a solution in which the resin composition is dissolved in a solvent depends on the polymer and the type of the solvent, but the solution temperature is 15 ° C. or higher and 90 ° C. or lower, preferably 15 ° C. or higher and 50 ° C. or lower. It is desirable to use a filter of 1 to 100 μm, preferably 0.1 to 5 μm.

  Regarding the filter used for filtering foreign matter, there are leaf disc type, candle filter type, leaf type, screen mesh, etc., but leaf disc type with relatively small residence time distribution and large filtration area. Are preferred. Examples of the filter element include a metal fiber sintered type, a metal powder sintered type, and a metal fiber / powder laminated type.

  The shape of the center pole of the filter includes external flow type, hexagonal column internal flow type, cylindrical internal flow type, etc., but any shape can be selected as long as the retention part is small, The external flow type is preferable.

  The viscosity of the obtained film-forming liquid is usually 1 to 1,000,000 (mPa · s), preferably 10 to 100,000 (mPa · s), more preferably 100 to 80,000 (mPa) at room temperature. S), particularly preferably 1000 to 60,000 (mPa · s).

Next, a film is formed by a solution casting method using the obtained film forming liquid.
Examples of the carrier used for film formation include metal drums, steel belts, polyester films made of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and belts made of polytetrafluoroethylene.

  When a polyester film is used as the carrier, a surface-treated film may be used. Here, as a surface treatment method, a commonly-used hydrophilic treatment method, for example, a method of forming a layer made of these resins by coating or laminating an acrylic resin or a sulfonate group-containing resin. Or the method etc. which improve the hydrophilic property of the film surface by corona discharge treatment etc. are mentioned.

  As a method for applying the film forming solution to the carrier, a method using a die or a coater, a spray method, a brush coating method, a roll coating method, a spin coating method, a dipping method, or the like can be used. Moreover, the thickness of the film obtained can also be controlled by repeatedly applying the film forming liquid.

The film formed as described above becomes an optical film through a normal drying step.
In the present invention, a specific method for removing the solvent in the film-forming solution applied to the carrier is not particularly limited, and a commonly used drying treatment method such as passing through a drying furnace by a number of rollers. However, if air bubbles are generated as the solvent evaporates in the drying process, the properties of the resulting film are remarkably deteriorated. To avoid this, the drying process is performed in two or more stages. It is preferable to control the temperature or air volume in each process.

The amount of residual solvent in the film thus obtained is usually 10% by weight or less, preferably 5% by weight or less, more preferably 1% by weight or less, and particularly preferably 0.5% by weight or less. Here, when the residual solvent amount in the film exceeds 10% by weight, the dimensional change with time becomes large when the film is actually used, which is not preferable. Further, the residual solvent lowers the glass transition temperature and lowers the heat resistance, which is not preferable.

  In addition, in order to perform the extending | stretching process mentioned later suitably, it may be necessary to adjust the amount of residual solvents in a film suitably within the said range. Specifically, the amount of residual solvent in the film is usually 10 to 0.1% by weight, preferably 5 to 0.1% by weight, in order to stably and uniformly express the phase difference in the film by the stretching and orientation treatment. More preferably, it may be 1 to 0.1% by weight. By leaving a trace amount of solvent in the film, the stretching and orientation treatment may be facilitated or the retardation may be easily controlled.

  The optical film of the present invention obtained by the solution casting method has a thickness of usually 0.1 to 3,000 μm, preferably 0.1 to 1,000 μm, more preferably 1 to 500 μm, most preferably 5 to 300 μm. It is. When this thickness is too small, it becomes difficult to actually handle the film. On the other hand, when this thickness is excessive, it becomes difficult to wind in a roll shape.

  In addition, the thickness distribution of the optical film according to the present invention obtained by the solution casting method is usually within ± 20%, preferably within ± 10%, more preferably within ± 5%, particularly preferably ±± with respect to the average value. Within 3%. Further, the variation rate of the thickness per 1 cm is usually 10% or less, preferably 5% or less, more preferably 1% or less, and particularly preferably 0.5% or less.

  In the optical film according to the present invention thus obtained, the value of the root mean square roughness Rq of the film obtained in accordance with the description of JIS-B0601: 2001 is in the range of 2 or less.

  Here, the root mean square roughness Rq is a value calculated from the differential curve by obtaining a contour curve based on the thickness curve of the film, performing second order numerical differentiation (Lagrange polynomial differentiation) of the obtained contour curve. The following formula is used.

(In the above formula, Rq is the root mean square roughness, l is the reference length which is the length in the X-axis direction of the contour curve, and Z (x) represents the height of the contour curve at an arbitrary position x.)
In the present invention, the contour curve is obtained using a moving box function as described in JIS-B0601: 2001, and the sampling number n of the moving box function is based on a sampling length of 10 cm, and an arbitrary number of steps m Is calculated as 10 stages. The contour curve using the moving box function is calculated according to “Journal of the Japan Society for Precision Engineering, Vol. 63, No. 3 (1997) pp. 378-382”. The numerical differentiation (Lagrange polynomial differentiation) is a three-point formula. used.

The optical film of the present invention thus obtained is excellent in transparency, has small surface roughness, excellent surface smoothness, little optical unevenness, and is suitable for optical applications such as various protective films as it is. It can also be used, and can be further stretched. In the case of producing a stretched film used as a retardation plate or the like, by using such an optical film according to the present invention, it is possible to prevent the occurrence of retardation unevenness when performing a stretching orientation treatment.
<Extension>
The unstretched optical film according to the present invention obtained as described above is subjected to stretching processing (stretch orientation treatment) so that the molecular chains of the copolymer of the present invention forming the film are regularly oriented. It can be set as the optical film (phase difference film) which orientates and has a function which gives a phase difference to transmitted light.

  Here, “regularly oriented” means that in an unstretched film, the molecular chain of the polymer compound (polymer) in the film is in a random state without facing a specific direction, whereas the polymer compound Means that the molecular chains are regularly oriented in a uniaxial direction, biaxial direction or thickness direction of the plane of the film. The degree of regularity of the orientation of the polymer compound varies and can be controlled by the stretching conditions.

  Specific examples of the stretching method include known uniaxial stretching methods and biaxial stretching methods. In other words, the horizontal uniaxial stretching method using the tenter method, the compression stretching method between rolls, the longitudinal uniaxial stretching method using two sets of rolls with different circumferences, or the biaxial stretching method combining horizontal uniaxial and longitudinal uniaxial, stretching by the inflation method The law etc. can be used.

  When the uniaxial stretching method is used, the stretching speed is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, and more preferably 100 to 1,000% / min. Yes, particularly preferably 100 to 500% / min.

  As the biaxial stretching method, a method of stretching in two directions intersecting each other at the same time or a method of stretching in a direction different from the first stretching direction after uniaxial stretching can be used. In these methods, the intersecting angle between the two stretching axes is not particularly limited because it is determined according to the desired characteristics, but is usually in the range of 120 to 60 degrees. The stretching speed may be the same or different in each stretching direction, and is usually 1 to 5,000% / min, preferably 50 to 1,000% / min, and more preferably 100 -1,000% / min, particularly preferably 100-500% / min.

  The processing temperature in the stretching process is not particularly limited, but is usually (Tg-5) ° C. when the glass transition temperature of the ring-opening copolymer (A) in the resin composition constituting the film is Tg. It is desirable that the temperature be in the range of ~ (Tg + 20) ° C, preferably in the range of Tg ~ (Tg + 10) ° C. By setting the treatment temperature within the above range, it is possible to suppress the occurrence of high phase difference and phase difference unevenness, and it is preferable because the control of the refractive index ellipsoid becomes easy.

  In addition, even if it carries out an extending | stretching process in the said temperature range, since the specific resin composition is used in this invention, problems, such as cloudiness, do not arise in the obtained optical film. This is because the Tg distribution of the ring-opening copolymer (A) in the resin composition used in the present invention is relatively small, and preferably the glass transition temperature distribution of the entire resin composition is relatively small. This is considered to be to plasticize substantially uniformly. On the contrary, when a cyclic olefin-based ring-opening copolymer having a large Tg distribution is included, it is not uniformly plasticized only by heating in the vicinity of Tg. It is thought to cause white turbidity during stretching.

  The draw ratio is not particularly limited because it is determined according to the desired properties such as retardation, but is usually 1.01 to 10 times, preferably 1.03 to 5 times, more preferably 1.03 to 3 times. It is.

In the present invention, since the resin composition containing the specific copolymer (A) is used, it is possible to apply a high stress to the film even at a low magnification because it can be stretched in the vicinity of its Tg.
Therefore, an optical film having a high retardation can be produced. In addition, when the draw ratio is relatively low as described above, it is possible to easily produce a retardation film having no transparency and optical axis deviation. When the stretch ratio is excessive, it may be difficult to control the phase difference and the optical axis.

  Although the stretched film may be cooled as it is at room temperature, it is kept in a temperature atmosphere of about Tg-100 ° C. to Tg for at least 10 seconds, preferably 30 seconds to 60 minutes, more preferably 1 minute to 60 minutes. It is also preferable to heat-set and then cool to room temperature, whereby an optical film having a stable retardation characteristic with little change over time in the retardation of transmitted light is obtained.

  The stretched optical film of the present invention obtained as described above gives a retardation to transmitted light due to the orientation of the molecules by stretching. This retardation is determined by the stretching ratio or before stretching. It can be controlled by adjusting the thickness of the film. For example, as for the draw ratio, even if the film has the same thickness before drawing, the absolute value of the retardation of transmitted light tends to increase as the draw ratio increases. A film that imparts a retardation to transmitted light can be obtained. As for the thickness of the film before stretching, even if the stretching ratio is the same, the larger the thickness of the film before stretching, the greater the absolute value of the phase difference given to transmitted light. By changing the thickness of the optical film, an optical film that imparts a desired phase difference to the transmitted light can be obtained.

  The optical film (retardation plate) obtained by stretching according to the present invention has a root mean square roughness Rq value of 0.3 or less, usually obtained in accordance with the description of JIS-B0601: 2001. Preferably it is the range of 0.01-0.25, and the surface roughness is very small, and it is excellent in an optical characteristic.

  In the stretched optical film of the present invention obtained as described above, the retardation value given to the transmitted light is determined by its use and is not uniquely determined. When used for a wavelength plate of an electroluminescence display element or a laser optical system, it is usually 1 to 10,000 nm, preferably 10 to 2,000 nm, and more preferably 15 to 1,000 nm.

  The phase difference of the light transmitted through the film is preferably highly uniform. Specifically, the dispersion at a light wavelength of 550 nm is usually ± 20% or less, preferably 10% or less, more preferably ± 5% or less is desirable. When the variation in the phase difference exceeds the range of ± 20%, when used in a liquid crystal display element or the like, color unevenness or the like may occur, resulting in a problem that the performance of the display body deteriorates. Similarly, the variation of the optical axis is usually ± 2.0 degrees or less, preferably ± 1.0 degrees or less, more preferably ± 0.5 degrees or less.

  The stretched optical film according to the present invention can be used as a retardation plate (retardation film) alone or in a laminate of two or more or bonded to a transparent substrate or the like. Moreover, it can also be laminated | stacked and used for another film, a sheet | seat, and a board | substrate.

When laminating a film or the like, a pressure-sensitive adhesive or an adhesive can be used. As the pressure-sensitive adhesive and adhesive, those having excellent transparency are preferably used. Specific examples thereof include natural rubber, synthetic rubber, vinyl acetate / vinyl chloride copolymer, polyvinyl ether, acrylic resin, and modified polyolefin. Adhesives such as resins, curable adhesives in which curing agents such as isocyanato group-containing compounds are added to the resins having functional groups such as hydroxyl groups and amino groups, polyurethane-based dry laminate adhesives, and synthetic rubber adhesives Agents, epoxy adhesives and the like.

In addition, a pressure-sensitive adhesive layer or an adhesive layer can be laminated in advance on the retardation plate in order to improve the workability of lamination with other films, sheets, substrates, and the like. In the case where the pressure-sensitive adhesive layer or the adhesive layer is laminated, the pressure-sensitive adhesive or the adhesive as described above can be used as the pressure-sensitive adhesive or the adhesive.
EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. In the following, parts or% are based on weight unless otherwise specified.

Various physical properties were measured or evaluated as follows.
Glass transition temperature (Tg )
Using a DSC6200 manufactured by Seiko Instruments Inc., the temperature increase rate was measured at 20 ° C. per minute under a nitrogen stream. Tg is the tangent on the baseline starting from point B, with the differential peak scanning calorie maximum peak temperature (point A) and the temperature at −20 ° C. from the maximum peak temperature (point B) plotted on the differential scanning calorimetry curve. And the intersection of the tangent starting from point A.

The hydrogenation rate nuclear magnetic resonance spectrometer (NMR) used was AVANCE 500 manufactured by Bruker, and ¹ H-NMR was measured using d-chloroform as the measurement solvent. 5.1-5.8 ppm of vinylene groups, 3
. The hydrogenation rate was calculated after calculating the monomer composition from the integrated value of 7 ppm methoxy group and 0.6 to 2.8 ppm aliphatic proton.

Weight average molecular weight Using HLC-8020 gel permeation chromatography (GPC) manufactured by Tosoh Corporation, polystyrene-converted weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) were measured with tetrahydrofuran (THF) solvent. Mn represents a number average molecular weight.

The residual solvent amount sample was dissolved in toluene and measured using GC-14B gas chromatography manufactured by Shimadzu Corporation.

Filtration rate measurement Compact cartridge filter manufactured by ADVANTEC: MCP-HX-E10S (average pore size 2.0 μm, filtration area 2000 cm ² ), MCP-JX-E10S (average pore size 1)
. 0 μm, filtration area 2000 cm ² ), MCS-020-E10SR (average pore diameter 0.2 μm)
m, filtration area 1800 cm ² ) Each one was connected in series in this order, and the polymer solution after hydrogenation was continuously filtered at room temperature and under nitrogen pressure of 3.0 kgf / cm ² , and the change over time in the filtration rate was measured. did. In addition, these filters were used using the housing for compact cartridges: MTA-2000T.

[Preparation Example 1]
8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene (DNM) 71 parts, dicyclopentadiene (DCP) 25 parts, and bicyclo [2.2.1] hept-2-ene (NB) 1 part are used as monomers. Together with 18 parts of molecular weight regulator 1-hexene and 200 parts of toluene were charged into a nitrogen-substituted reaction vessel and heated to 100 ° C.

To this, 0.005 part of triethylaluminum and 0.005 part of methanol-modified WCl ₆ (anhydrous methanol: PhPOCl ₂ : WCl ₆ = 103: 630: 427 weight ratio) were added and reacted for 60 minutes to obtain a copolymer. .

FIG. 1 shows a ¹ H-NMR measurement chart of the obtained copolymer. A double bond of the main chain of the copolymer was observed at 5.2 to 5.6 ppm at 5.8 ppm in DCP-derived vinylene proton (Hc), 3.65 ppm at DNM-derived methoxy proton (He). The NB content in the copolymer is determined by subtracting the DCP structural unit (protons 3 times that of Hb) and the DNM structural unit (protons that are 2/3 times that of He), so that the monomer structural units in the copolymer are subtracted. As a result of the calculation, DNM / DCP / NB = 72.76 / 26.01 / 1.23 (% by weight).

Next, the obtained copolymer solution was placed in an autoclave, and 200 parts of toluene was further added. Next, 0.06 part of RuHCl (CO) [P (C ₆ H ₅ )] ₃ as a hydrogenation catalyst was added, nitrogen substitution was performed three times, and hydrogen substitution was performed three times at 20 ° C. It was set to 5 MPa. After heating from 20 ° C. to 165 ° C., hydrogen gas was charged into the reactor, and the pressure was adjusted to 10 MPa. Thereafter, the reaction was carried out at 165 ° C. for 3 hours while maintaining the pressure at 10 MPa. After completion of the reaction, 100 parts by weight of toluene, 3 parts by weight of distilled water, 0.72 parts by weight of lactic acid and 0.00214 parts by weight of hydrogen peroxide were added and heated at 60 ° C. for 30 minutes. Thereafter, 200 parts by weight of methanol was added and heated at 60 ° C. for 30 minutes, and when cooled to 25 ° C., it was separated into two layers. Remove 500 parts by weight of the supernatant, add 350 parts by weight of toluene and 3 parts by weight of water again, heat at 60 ° C. for 30 minutes, then add 240 parts by weight of methanol, heat at 60 ° C. for 30 minutes, and cool to 25 ° C. Separated into two layers. Remove 500 parts by weight of the supernatant, add 350 parts by weight of toluene and 3 parts by weight of water, heat at 60 ° C. for 30 minutes, then add 240 parts by weight of methanol, heat at 60 ° C. for 30 minutes, and cool to 25 ° C. Separated into two layers. Finally, after removing 500 parts by weight of the supernatant, the polymer solution was heated to 50 ° C. and circulated and filtered using 2.0 μm, 1.0 μm and 0.2 μm filters. Even after 1000 hours, the differential pressure of the filter was constant and no filter clogging occurred. When the ratio of methanol to toluene in the solution was confirmed by gas chromatography, methanol / toluene = 20/80 wt%, the dielectric constant of the mixed solvent was 8.429 (dielectric constant of methanol = 32.63, dielectric constant of toluene = Calculated from 2.379). Thereafter, the solid content of the polymer was concentrated to 55%, the solvent was removed at 250 ° C., 4 torr, and the residence time of 1 hour, and the polymer was passed through a 10 μm polymer filter to obtain a copolymer (A1).

The obtained copolymer (A1) has a weight average molecular weight (Mw) = 6.10 × 10 ⁴ , a molecular weight distribution (Mw / Mn) = 3.8, an intrinsic viscosity (η _inh ) = 0.52, a glass transition. Temperature (Tg) =
It was 146 ° C. Moreover, Tg distribution was 25 degreeC. A ¹ H-NMR chart of copolymer (A1), which is a hydrogenated copolymer, is shown in FIG. From this, the hydrogenation rate of the copolymer (A1) was determined, and the olefinically unsaturated bond was hydrogenated by 99.9% or more.

[Preparation Example 2]
A copolymer (B1) was obtained in the same manner as in Preparation Example 1 except that 93 parts of DNM and 9 parts of NB were used as monomers in Preparation Example 1. As a result of calculating the monomer structural unit in the copolymer, it was DNM / NB = 92.30 / 9.70 (wt%). The obtained copolymer (B1) is
Weight average molecular weight (Mw) = 6.10 × 10 ⁴ , molecular weight distribution (Mw / Mn) = 3.8, intrinsic viscosity (η _inh ) = 0.52, glass transition temperature (Tg) = 137 ° C. Moreover, Tg distribution was 25 degreeC. When the hydrogenation rate was determined in the same manner as in Preparation Example 1, the olefinically unsaturated bond was hydrogenated by 99.9% or more.

[Preparation Example 3]
A copolymer (B2) was obtained in the same manner as in Preparation Example 2 except that 93 parts of DNM and 5 parts of NB were used as monomers in Preparation Example 2. As a result of calculating the monomer structural unit in the copolymer, it was DNM / NB = 92.30 / 5.40 (wt%). The obtained copolymer (B2) has a weight average molecular weight (Mw) = 5.30 × 10 ⁴ , a molecular weight distribution (Mw / Mn) = 3.9, an intrinsic viscosity (η _inh ) = 0.51, and a glass transition. The temperature (Tg) was 150 ° C. Moreover, Tg distribution was 25 degreeC. When the hydrogenation rate was determined in the same manner as in Preparation Example 1, the olefinically unsaturated bond was hydrogenated by 99.9% or more.

[Preparation Example 4]
A copolymer (B3) was obtained in the same manner as in Preparation Example 2, except that 86 parts of DNM and 14 parts of NB were used as monomers in Preparation Example 2. As a result of calculating the monomer structural unit in the copolymer, it was DNM / NB = 82.3 / 17.7 (% by weight). The obtained copolymer (B3) has a weight average molecular weight (Mw) = 6.05 × 10 ⁴ , a molecular weight distribution (Mw / Mn) = 4.1, an intrinsic viscosity (η _inh ) = 0.53, a glass transition. The temperature (Tg) was 120 ° C. Moreover, Tg distribution was 25 degreeC. When the hydrogenation rate was determined in the same manner as in Preparation Example 1, the olefinically unsaturated bond was hydrogenated by 99.9% or more.

[Preparation Example 5]
A copolymer (A2) was obtained in the same manner as in Preparation Example 1, except that DNM / DCP = 85/15 parts was used as a monomer in Preparation Example 1. As a result of calculating the monomer structural unit in the copolymer, it was DNM / DCP = 82.8 / 17.2 (% by weight). The obtained copolymer (A2) has a weight average molecular weight (Mw) = 5.60 × 10 ⁴ and a molecular weight distribution (Mw / Mn) = 3.9.
Inherent viscosity (η _inh ) = 0.52, glass transition temperature (Tg) = 157 ° C. Also,
The Tg distribution was 23 ° C. When the hydrogenation rate was determined in the same manner as in Preparation Example 1, the olefinically unsaturated bond was hydrogenated by 99.9% or more.

[Preparation Example 6]
A copolymer (A3) was obtained in the same manner as in Preparation Example 1, except that DNM / DCP = 60/40 parts was used as a monomer in Preparation Example 1. As a result of calculating the monomer structural unit in the copolymer, it was DNM / DCP = 57.9 / 42.1 (% by weight). The obtained copolymer (A3) has a weight average molecular weight (Mw) = 5.72 × 10 ⁴ and a molecular weight distribution (Mw / Mn) = 4.1.
Inherent viscosity (η _inh ) = 0.52, glass transition temperature (Tg) = 133 ° C. Also,
The Tg distribution was 25 ° C. When the hydrogenation rate was determined in the same manner as in Preparation Example 1, the olefinically unsaturated bond was hydrogenated by 99.9% or more.

[Preparation Example 7]
A copolymer (b) was obtained in the same manner as in Preparation Example 2, except that 100 parts of DNM was used as a monomer in Preparation Example 2. As a result of calculating the monomer structural unit in the copolymer, it was DNM = 100 (% by weight). The obtained copolymer (b) has a weight average molecular weight (Mw) = 5.50 × 10 ⁴ , a molecular weight distribution (Mw / Mn) = 3.8, an intrinsic viscosity (η _inh ) = 0.51, and a glass transition. The temperature (Tg) was 167 ° C. Moreover, Tg distribution was 25 degreeC. When the hydrogenation rate was determined in the same manner as in Preparation Example 1, the olefinically unsaturated bond was hydrogenated by 99.9% or more.

[Example 1]
Using the copolymer (A1) and copolymer (B1) pellets obtained in Preparation Examples 1 and 2, a 28% methylene chloride (dielectric constant = 9.08) solution was copolymerized (A1) / copolymer. It was produced at a ratio of (B1) = 70/30. After cooling the polymer solution at 0 ° C. for 30 days, circulation filtration at 0 ° C. was performed with a 2.0 μm filter alone. The amount of foreign matter of 2 μm or more 3 hours after the circulation filtration was zero. Even after 1000 hours of circulation filtration, the differential pressure of the filter was constant and no filter clogging occurred. The glass transition temperature (Tg) after drying of the cast composition was 143 ° C., and the Tg distribution was 25 ° C. The film was stretched at 150 ° C. and 2.0 times. The film thickness after stretching was 27 ± 0.1 μm, phase difference = 305 nm ± 2 nm, and HAZE was 0.3. The Rq value of the original fabric as an index of appearance was Rq = 0.120. No foreign matter was observed on the film after stretching. Rq after stretching was 0.090.

[Example 2]
In Example 1, it implemented similarly except having blended the copolymer (A1) and the copolymer (B2) synthesize | combined in the preparation example 3 by the composition of 90/10. After cooling the polymer solution at 0 ° C. for 30 days, circulation filtration at 0 ° C. was performed with a 2.0 μm filter alone. The amount of foreign matter of 2 μm or more 3 hours after the circulation filtration was zero. Even after 1000 hours of circulation filtration, the differential pressure of the filter was constant and no filter clogging occurred. The glass transition temperature (Tg) after drying of the cast composition was 145 ° C., and the Tg distribution was 25 ° C. The film was stretched at 150 ° C. and 2.0 times. The film thickness after stretching was 27 ± 0.1 μm, phase difference = 300 nm ± 2 nm, and HAZE was 0.3. The Rq value of the original fabric as an index of appearance was Rq = 0.130. No foreign matter was observed on the film after stretching. Rq after stretching was 0.095.

[Example 3]
The same procedure as in Example 1 was performed except that the copolymer (A2) synthesized in Preparation Example 5 and the copolymer (B3) synthesized in Preparation Example 4 were blended with a composition of 50/50. After cooling the polymer solution at 0 ° C. for 30 days, circulation filtration at 0 ° C. was performed with a 2.0 μm filter alone. The amount of foreign matter of 2 μm or more 3 hours after the circulation filtration was zero. Even after 1000 hours of circulation filtration, the differential pressure of the filter was constant and no filter clogging occurred. The glass transition temperature (Tg) after drying of the cast composition was 149 ° C., and the Tg distribution was 25 ° C. Stretched 2.0 times at 154 ° C. The film thickness after stretching was 27 ± 0.1 μm, phase difference = 308 nm ± 2 nm, and HAZE was 0.3. The Rq value of the original fabric as an index of appearance was Rq = 0.130. No foreign matter was observed on the film after stretching. Rq after stretching was 0.093.

[Example 4]
The same procedure as in Example 1 was carried out except that the copolymer (A3) synthesized in Preparation Example 6 and the copolymer (B2) synthesized in Preparation Example 3 were blended with a composition of 70/30. After cooling the polymer solution at 0 ° C. for 30 days, circulation filtration at 0 ° C. was performed with a 2.0 μm filter alone. The amount of foreign matter of 2 μm or more 3 hours after the circulation filtration was zero. Even after 1000 hours of circulation filtration, the differential pressure of the filter was constant and no filter clogging occurred. The glass transition temperature (Tg) after drying of the cast composition was 146 ° C., and the Tg distribution was 27 ° C. 151 degreeC and 2.0 time extending | stretching were performed. The film thickness after stretching was 27 ± 0.1 μm, phase difference = 309 nm ± 2 nm, and HAZE was 0.3. The Rq value of the original fabric as an index of appearance was Rq = 0.135. No foreign matter was observed on the film after stretching. Rq after stretching was 0.102.

[Comparative Example 1]
In Example 1, it implemented similarly except not using a copolymer (B1). Filter clogging occurred 3 hours after the start of circulating filtration. Using a composition not subjected to filtration, a film was formed in the same manner as in Example 1, and stretched at 150 ° C. and 2.0 times. The film thickness after stretching was 27 ± 0.1 μm, phase difference = 275 nm ± 2 nm, and HAZE was 0.3. 15
The film was stretched 2.0 times at 0 ° C. The film thickness after stretching was 27 ± 0.1 μm, phase difference = 275 nm ± 2 nm, and HAZE was 0.3.

[Comparative Example 2]
In Example 1, it implemented similarly except having blended the copolymer (A1) and the copolymer (b) synthesize | combined in the preparation example 7 by the composition of 70/30. After cooling the polymer solution at 0 ° C. for 30 days, circulation filtration at 0 ° C. was performed with a 2.0 μm filter alone. The amount of foreign matter of 2 μm or more 3 hours after the circulation filtration was zero. Even after 1000 hours of circulation filtration, the differential pressure of the filter was constant and no filter clogging occurred. Two glass transition temperatures were confirmed after drying of the cast composition. Tg = 143 ° C., Tg distribution is 25 ° C., Tg = 167 ° C., Tg distribution is 23 ° C. The film before stretching had a HAZE of 80, which was very poor in transparency and difficult to use for optical films.

  The resin composition of the present invention is excellent in transparency and heat resistance, and can be suitably used for general optical applications. However, it can be suitably used by processing into a film or a sheet. Since it can be processed stably without problems such as white turbidity, it is optimal for applications that require stretching, for example, optical film applications such as retardation plates.

  More specifically, the optical film or phase difference plate according to the present invention includes a mobile phone, a digital information terminal, a pager, navigation, an in-vehicle liquid crystal display, a liquid crystal monitor, a light control panel, a display for OA equipment, and an AV equipment. It can be used for various liquid crystal display elements such as a display for display, an electroluminescence display element or a touch panel. It is also useful as a wave plate used in an optical disk recording / reproducing apparatus such as a CD, CD-R, MD, MO, and DVD.

FIG. 1 shows a ¹ H-NMR measurement chart of the copolymer (before hydrogenation) obtained in Preparation Example 1. FIG. 2 shows a ¹ H-NMR measurement chart of copolymer (A1), which is the copolymer after hydrogenation obtained in Preparation Example 1.

Claims (7)

(A) 50 to 95% by weight of the structural unit (1) represented by the following formula (1),
Copolymer (A) having 5 to 50% by weight of structural unit (2) represented by the following formula (2) (however, the total amount of structural unit (1) and structural unit (2) is 100% by weight) ); 10-99 parts by weight;
(B) 70-95 weight% of structural units (1) represented by the following formula (1)
0 to 10% by weight of the structural unit (2) represented by the following formula (2),
Copolymer (B) having 5 to 20% by weight of structural unit (3) represented by the following formula (3) (however, the total amount of structural unit (1), structural unit (2) and structural unit (3)) 1 to 90 parts by weight of a resin composition.

(In formula (1), m is 0, 1 or 2, X is independently a group represented by the formula: —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —, R ^{1 to} R ⁴ are each independently a hydrogen atom; a halogen atom; a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon; or Represents a polar group, provided that at least one of R ^{1 to} R ⁴ is a polar group and at least one of the other R ^{1 to} R ⁴ is a hydrocarbon group having 1 to 10 carbon atoms.)

(In formula (2), X is independently a group represented by the formula: —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —, and R ^{5 to} R ¹⁰ are each independently hydrogen. An atom; a halogen atom; a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon; or a polar group.

(In the formula (3), n is 0, 1 or 2, X is independently a group represented by the formula: —CH═CH— or a group represented by the formula: —CH ₂ CH ₂ —, R ^{11 to} R ¹⁴ are each independently a hydrogen atom; a halogen atom; or a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms which may have a linking group containing oxygen, nitrogen, sulfur or silicon Represents.) The resin composition according to claim 1, wherein the structural unit (1) in the copolymers (A) and (B) has a group represented by the following formula (4) as a polar group;
− (CH ₂ ) _p COOR ′ (4)
(In Formula (4), p is 0 or an integer of 1 to 5, and R ′ is a hydrocarbon group having 1 to 15 carbon atoms).   An optical film comprising the resin composition according to claim 1.   A retardation film obtained by stretching and orientationing an unstretched film containing the resin composition according to claim 1.   A method for producing an optical film, comprising forming the resin composition according to claim 1 or 2 by a solution casting method.   A method for producing a retardation film, comprising subjecting the optical film obtained by the method according to claim 5 to stretch orientation under a temperature condition of Tg to (Tg + 10) ° C. of the optical film. An unstretched film comprising the resin composition according to claim 1 or 2,
A method for producing a retardation film, wherein the film is stretched and oriented under a temperature condition of Tg to (Tg + 10) ° C. of the film.

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