JP2010105188A - Device and method for manufacturing thermoplastic resin sheet, and thermoplastic resin sheet obtained thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin sheet having small residual phase difference, excellent optical characteristic, high surface smoothness, and suitable as an optical sheet used for liquid crystal display element or the like, a manufacturing device and a manufacturing method. <P>SOLUTION: The manufacturing device 1 is provided with a nip pressure control means for controlling a linear pressure applied between a belt 15 and a third cooling roll 13, a roll temperature control means for controlling the temperature of the peripheral surface 131 of the third cooling roll 13, and a belt temperature control means for controlling the temperature of the belt 15. The belt temperature control means controls the temperature of the belt 15 while the roll temperature control means controls the temperature of the peripheral surface 131, and the nip pressure control means controls the linear pressure between belt 15 and the third cooling roll 13, and therefore, the sheet having the small residual phase difference, surface roughness, and high surface smoothness is stably obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin sheet production apparatus and production method having excellent optical characteristics suitable as an optical sheet used for liquid crystal display elements and the like, and a thermoplastic resin sheet obtained thereby.

  In a liquid crystal display element, a sheet having a high total light transmittance and a low retardation is required as a substrate for transparent electrodes. In particular, when utilizing an external light antireflection function using a circularly polarizing plate, a low phase difference is an essential requirement, and a method for manufacturing such a low phase difference sheet is known (for example, from Patent Document 1). 11).

Patent Document 1 discloses that a cyclic olefin-based thermoplastic resin extruded from a T-die is pinched by a cooling roll and a cooling belt. And the point by which the said cyclic olefin type thermoplastic resin is crimped | bonded to the surface of the cooling belt, and is cooled by this is disclosed. Moreover, the point that a transparent resin sheet is manufactured when the cyclic olefin type thermoplastic resin crimped | bonded to the surface of the cooling belt is peeled from the surface of the cooling belt with a peeling roll is disclosed.
In Patent Document 2, a molten thermoplastic resin extruded from a die into a sheet is passed between a metal cast drum and a metal endless belt pressed against the cast drum along its circumferential direction. Thus, a method for producing an optical thermoplastic resin sheet is disclosed in which a thermoplastic resin is sandwiched and pressed against an endless belt. Further, it is disclosed that when the glass transition temperature of the thermoplastic resin is Tg [° C.], the surface temperature of the cast drum is Tg [° C.] or more and Tg + 50 [° C.] or less.
In Patent Document 3, the cyclic olefin-based resin discharged from the discharge port of the die passes between the belt and the roll wound around the first holding roll and is pressure-bonded to the roll. The point by which the sheet | seat is formed when the made cyclic olefin resin is peeled from the said roll by the roll for peeling is disclosed. Further, it is disclosed that the temperature of the surface of the belt is adjusted.
In Patent Document 4, the cyclic olefin resin extruded from a die is passed between a cooling roll and a pressing roll and sandwiched between the cooling roll and the pressing roll, whereby the cyclic olefin resin is cooled by a cooling roll. It is disclosed that the resin sheet is molded by being brought into close contact with the surface and cooling.
In Patent Documents 5 and 6, the temperature (V1) of the first metal belt at which the thermoplastic polymer sheet melt-extruded from the T die contacts the metal belt is equal to the glass transition point (Tg) of the thermoplastic polymer. , Tg-20 ≦ V1 ≦ Tg + 100 (° C.), a method for producing a thermoplastic polymer sheet is disclosed. Further, it is also disclosed that the temperature (V2) of the metal belt having no curvature with respect to the flow direction of the thermoplastic polymer sheet is in the range of Tg-30 ≦ V2 ≦ Tg + 30 (° C.). Further, the temperature (V3) of the metal belt in the portion where the cooled thermoplastic polymer sheet is separated from the metal belt is Tg-100 ≦ V3 ≦ Tg−20 (° C.) and V3 ≦ V2 ≦ V1 ( It is also disclosed that it is in the range of ° C.
In Patent Document 7, when an amorphous thermoplastic resin film extruded from a die into a sheet is brought into close contact with a cooling roll, the glass transition temperature (Tg) of the amorphous thermoplastic resin is from −10 ° C. to Tg-40. A method for producing an optical film that is narrowed by a touch roll and a cooling roll that are temperature-controlled at 0 ° C. is disclosed.
In Patent Document 8, a film-like thermoplastic resin extruded in a molten state from a die is placed between a metal cooling roll and an endless metal belt that is tensioned so as not to be loosened by a plurality of pressure-controlled rolls. A method for producing an optical film is disclosed in which the pressure is narrowed in an arc shape, and then the cooled film is peeled off from a metal cooling roll by a peeling means.
Patent Document 9 discloses a method for producing a cyclic olefin polymer film having a step of narrowing a molten cyclic olefin polymer extruded from a T-die into a sheet shape by a casting roll and a touch roll, The manufacturing method of the film whose surface temperature is 40 degreeC or more and (Tg-20) degrees C or less is disclosed.
Patent Document 10 discloses a method for producing a thermoplastic resin film in which a film-like thermoplastic resin extruded from a die in a molten state is sandwiched between a metal pressing body and a metal cast cooling roll, and solidified by cooling. The temperature of the film-like thermoplastic resin immediately before being sandwiched between the pressing body and the cast cooling roll is Tg + 20 ° C. to Tg + 90 ° C., and the surface temperature (Tt) of the metal pressing body and the surface temperature of the cast cooling roll The manufacturing method of the thermoplastic resin film whose difference with (T1) is 0.5 degreeC <= T1-Tt <= 20 degreeC is disclosed.
Patent Document 11 discloses that when a polycarbonate resin is melted and extruded into a sheet and a sheet is produced using a plurality of cooling rolls, the sheet-like material is not sandwiched and pressurized on the first cooling roll. ing.

Japanese Patent No. 40695534 JP 2000-280268 A JP 2007-237495 A JP 2001-30337 A Japanese Patent No. 3698910 JP 2000-263628 A JP 2004-330651 A JP-A-9-290427 JP 2006-192749 A JP 2008-55890 A Japanese Patent No. 3754519

However, the one described in Patent Document 1 has a problem that, particularly when the sheet thickness is thick, there is a temperature difference between the front and back of the sheet, and a low residual phase difference cannot be achieved.
In the case of the one described in Patent Document 2, when the discharge is high and the sheet thickness is increased, a sheet appearance defect due to dripping of the melt web occurs, or a sheet peeling defect occurs from the cast drum, thereby obtaining a smooth sheet. There is a problem that can not be.
Although the thing of the patent document 3 has the temperature adjustment mechanism from a belt back surface, it aims at setting the pinching area of Tg + 5 degreeC or more. Therefore, the belt thickness is thin, and the target temperature control is difficult at the time of high discharge. Therefore, there is a problem that a low residual phase difference cannot be achieved.
Even in the ones described in Patent Documents 4 to 11, a method for producing an optical sheet is disclosed, but there is a problem that a low residual retardation cannot be sufficiently achieved and a sufficient sheet cannot be obtained even in surface smoothness. is there.

  An object of the present invention is a thermoplastic resin sheet having a small residual phase difference, excellent optical characteristics, high surface smoothness, and suitable as an optical sheet used for liquid crystal display elements, a manufacturing apparatus thereof, and a manufacturing method thereof Is to provide.

The thermoplastic resin sheet manufacturing apparatus of the present invention includes a first cooling roll whose surface is coated with an elastic material, and a metal belt having a mirror-finished surface wound between the second cooling roll, A third cooling roll disposed opposite to the first cooling roll via a metal belt, and extruding a molten thermoplastic resin from a die attached to an extruder, and the metal belt and An apparatus for producing a thermoplastic resin sheet, which is introduced between the third cooling rolls, then cooled while being conveyed by the metal belt and peeled off from the metal belt to form a thermoplastic resin sheet. Nip pressure control means for controlling the linear pressure applied between the metal belt and the third cooling roll, roll temperature control means for controlling the surface temperature of the third cooling roll, and the metal belt. Temperature Characterized by comprising a belt temperature controlling means for controlling.
In the present invention, the temperature of the surface of the third cooling roll and the temperature of the metal belt are controlled, and the linear pressure between the metal belt and the third cooling roll is also controlled. A small sheet having high surface smoothness can be stably obtained. And the sheet | seat which has such a characteristic can be utilized suitably as an optical sheet used for a liquid crystal display element.
Normally, the belt during film formation is heated by the resin film, resulting in a temperature difference between the front and back of the sheet. However, the roll temperature control means and the belt temperature control means reduce the temperature difference between the front and back of the sheet, thereby reducing the shrinkage between the front and back. Since the occurrence of the difference is suppressed, a low residual phase difference can be realized.

In the manufacturing apparatus of the present invention, it is preferable that the nip pressure control means controls the linear pressure to 30 kg / cm or less.
In the present invention, since the linear pressure (nip pressure) is specified, it is possible to prevent a bank from being partially generated in the sheet width direction. Therefore, a stable low phase difference sheet can be obtained. The nip pressure is a load per sheet unit width applied between the metal belt and the third cooling roll.

Furthermore, the manufacturing apparatus of the present invention preferably includes a warp correction roll for correcting the warp of the thermoplastic resin sheet peeled from the metal belt.
In the present invention, the warp correction roll can substantially prevent sheet warpage, which is an essential requirement for use in a liquid crystal display element.

Moreover, the manufacturing apparatus of this invention WHEREIN: It is preferable that the said curvature correction roll peels the said sheet | seat from the said metal belt with the peeling tension of 0.1 kg / mm < ² > or less.
In this invention, since peeling strength was made into below a specific value, it can prevent that a phase difference nonuniformity generate | occur | produces in a sheet | seat.

Moreover, in the manufacturing apparatus of this invention, it is preferable to control the surface temperature of the said curvature correction roll by the correction roll temperature control means.
In the present invention, by controlling the temperature of the surface of the warp correction roll, the warp of the sheet can be easily corrected, and inconveniences such as adhesion of the sheet to the surface of the warp correction roll can be prevented.

And in the manufacturing apparatus of this invention, it is preferable that the said correction roll temperature control means controls the temperature of the surface of the said curvature correction roll to (Tg-20 degreeC) or more and (Tg + 10 degreeC) or less.
In this invention, since the surface temperature of the warp correction roll is specified, the sheet warp is sufficiently corrected. Moreover, it can prevent that a sheet | seat adheres to the surface of a correction | amendment roll by specifying the surface temperature, and can prevent that external appearance property falls. Furthermore, it is possible to prevent the occurrence of retardation unevenness due to stretching when the sheet is peeled off from the correction roll.

And in the manufacturing apparatus of this invention, it is preferable that the distance from the extrusion port of the said die to the said metal belt and said 3rd cooling roll shall be 200 mm or less.
In this invention, it can suppress that the sheet | seat extruded from die | dye flutters, and it can prevent that thickness nonuniformity arises.

Furthermore, in the manufacturing apparatus of the present invention, the temperature of the surface of the third cooling roll controlled by the roll temperature control means and the temperature of the metal belt controlled by the belt temperature control means are each (Tg-60 ° C.). ) Or more and Tg or less, and the temperature difference is preferably within 30 ° C.
In this invention, since the temperature of the surface of the third cooling roll and the temperature of the metal belt are specified, it is possible to prevent the sheet from being rapidly cooled and to prevent a large residual phase difference from occurring when the sheet is sandwiched. be able to. Further, it is possible to prevent the occurrence of phase difference unevenness and thickness unevenness due to the tension at the time of peeling.
Further, since the temperature difference between the surface temperature of the third cooling roll and the temperature of the metal belt is specified, the temperature difference between the front and back sides of the sheet is reduced, and it is possible to prevent the difference in shrinkage from occurring. Therefore, a sheet having a small residual retardation can be obtained.

  The method for producing a thermoplastic resin sheet of the present invention includes a first cooling roll whose surface is coated with an elastic material, and a metal belt having a mirror-finished surface wound between the second cooling roll, Extruding a molten thermoplastic resin from a die attached to an extruder using a manufacturing apparatus comprising a third cooling roll disposed opposite to the first cooling roll via a metal belt A thermoplastic resin sheet that is introduced between the metal belt and the third cooling roll, and then cooled while being conveyed by the metal belt and peeled off from the metal belt to form a thermoplastic resin sheet. A method for producing a sheet, wherein the nip pressure between the metal belt and the third cooling roll is controlled to 30 kg / cm or less, and the molten heat is applied between the metal belt and the third cooling roll. Plastic tree And a step of conveying the thermoplastic resin by the metal belt in a state in which the temperature of the surface of the third cooling roll and the temperature of the metal belt are controlled. To do.

  In the manufacturing method of the present invention, the temperature of the surface of the third cooling roll and the temperature of the metal belt are controlled to (Tg−60 ° C.) or more and Tg or less, and the temperature difference is controlled within 30 ° C. It is preferable.

Moreover, in the manufacturing method of this invention, it is preferable that the peeling tension at the time of peeling from the said metal belt shall be 0.1 kg / mm < ² > or less.

Furthermore, in the manufacturing method of this invention, it is preferable to convey the thermoplastic resin sheet after making it peel from the said metal belt with a curvature correction roll.
In this invention, since the sheet | seat with which curvature was suppressed is obtained, it can utilize suitably for a liquid crystal display element.

And in the manufacturing method of this invention, it is preferable to control the temperature of the surface of the said curvature correction roll to (Tg-20 degreeC) or more and (Tg + 10 degreeC) or less.
According to the method for producing a thermoplastic resin sheet of the present invention, the same effects as those of the thermoplastic resin sheet of the present invention are exhibited.

The thermoplastic resin sheet of the present invention has a retardation in the in-plane direction of 20 nm or less, a surface roughness (Ra) of 0.05 μm or less, a warpage rate of 0.2% or less, and a sheet thickness of 0.05 mm or more. 00 mm or less, and total light transmittance is 88% or more.
The sheet of the present invention has a small residual retardation and high surface smoothness. Therefore, the sheet | seat of this invention can be utilized suitably for a liquid crystal display element etc.
The in-sheet direction retardation means a phase difference when light enters perpendicularly to the sheet surface. Also, the warpage rate of the sheet is a square sample cut to a length of 500 mm in the flow direction of the thermoplastic resin sheet and a length of 500 mm in the width direction, with the front side of the sheet facing up on the surface plate. When the height of the sheet farthest from the surface of the surface plate is measured in the case and the case below, the maximum value is obtained, and then the warpage rate is calculated by the following equation.
Warpage rate (%) = Maximum warpage (mm) x 100/500 (mm)
Here, when the phase difference is larger than 20 nm, for example, a sheet for optical use such as a function of preventing reflection of external light by a circularly polarizing plate is not exhibited sufficiently, so the phase difference may be 20 nm or less. Preferably, it is 10 nm or less.
Also, when the surface roughness (Ra) is greater than 0.05 μm, the surface smoothness is low, and when incorporated in a liquid crystal display, unevenness is likely to occur on the display screen, so the surface roughness is 0.05 μm or less. It is preferable that the thickness is 0.03 μm or less.
Furthermore, if the warpage rate is greater than 0.2%, for example, the secondary processing such as transparent electrode processing may be hindered, or the liquid crystal cell may be deformed when incorporated in a liquid crystal display. % Or less, and more preferably 0.1% or less.
Further, if the total light transmittance is less than 88%, the display becomes dark when incorporated in a liquid crystal display. Therefore, the total light transmittance is preferably 88% or more, and more preferably 90% or more. .

With reference to FIG. 1, the manufacturing apparatus and manufacturing method of a thermoplastic resin sheet (hereinafter abbreviated as “sheet”) according to the present embodiment, and the sheet obtained thereby will be described.
First, the configuration of the sheet manufacturing apparatus of the present embodiment will be described.

The manufacturing apparatus 1 includes a metal belt 15 (hereinafter referred to as “a belt”) wound between a T die 10 of an extruder, a first cooling roll 11, a second cooling roll 12, and a fourth cooling roll 14. Belt 15 ”), and a third cooling roll 13 disposed opposite to the first cooling roll 11 with the sheet 20 and the belt 15 interposed therebetween.
A fourth cooling roll 14 is disposed below the first cooling roll 11, and a second cooling roll 12 is disposed at substantially the same height as the fourth cooling roll 14. The third cooling roll 13 is disposed opposite to the first cooling roll 11 at substantially the same height position. The third cooling roll 13 is provided so as to come into contact with the first cooling roll 11 via the sheet 20 and the belt 15 and to embrace the sheet 20 pressed to the third cooling roll 13 side by the belt 15. Yes. That is, the belt 15 and the sheet 20 in contact with the belt 15 meander around the part of the peripheral surface 131 of the third cooling roll 13.
In addition, the manufacturing apparatus 1 includes a warp correction roll 17 disposed at a predetermined distance from the third cooling roll 13 in the vicinity of the third cooling roll 13, and a sheet 20 corrected by the warp correction roll 17. And a plurality of pass rolls 18 for sending.

Further, the manufacturing apparatus 1 includes a nip pressure control unit that controls the linear pressure applied between the belt 15 and the third cooling roll 13, and a roll temperature that controls the temperature of the peripheral surface 131 that is the surface of the third cooling roll 13. Control means, correction roll temperature control means for controlling the temperature of the peripheral surface 171 that is the surface of the warp correction roll 17, and belt temperature control means for controlling the back surface temperature of the belt 15 are provided.
Here, the peripheral surface 131 is a surface that comes into contact with the sheet 20 conveyed by the belt 15. The belt temperature control means includes a second roll temperature control means for controlling the temperatures of the peripheral surfaces 111, 121, and 141 of the first, second and fourth cooling rolls 11, 12 and 14, a belt temperature adjuster 16, Have The back surface temperature of the belt 15 is controlled by the second roll temperature control means and the belt temperature adjuster 16.
The belt temperature controller 16 is disposed between the first and second cooling rolls 11 and 12 and has a cooling surface 161 that substantially faces the peripheral surface 131 with the belt 15 interposed therebetween. The cooling surface 161 cools the belt 15 from a position where the belt 15 and the first cooling roll 11 are separated from a position where the sheet 20 and the belt 15 are separated.
Further, the roll temperature control means and the belt temperature control means control the temperature of the peripheral surface 131 and the temperature of the belt 15 to (Tg−60 ° C.) or more and Tg or less, and control the temperature difference within 30 ° C. Here, Tg is the glass transition temperature of the thermoplastic resin. If the temperature of the peripheral surface 131 and the temperature of the belt 15 are less than (Tg−60 ° C.), a large residual phase difference may occur when the sheet 20 is rapidly cooled and pinched. On the other hand, when the temperature of the peripheral surface 131 and the temperature of the belt 15 exceed Tg, respectively, the peeling temperature of the sheet 20 becomes Tg or higher, and phase difference unevenness and thickness unevenness may occur due to tension at the time of peeling. If the temperature difference exceeds 30 ° C., a difference in shrinkage may occur due to the temperature difference between the front and back sides of the sheet 20, and the residual phase difference may increase.
The manufacturing apparatus 1 may include a second temperature controller that faces the peripheral surface 171 of the warp correction roll 17.

  The T die 10 has an extrusion port 101 through which the sheet 20 is extruded. The distance from the extrusion port 101 until the resin is introduced between the belt 15 and the third cooling roll 13 (air gap) is preferably 200 mm or less, and more preferably 180 mm or less. If the air gap exceeds 200 mm, the sheet 20 may flutter and uneven thickness may occur, and the molten sheet 20 is cooled before being nipped (nip), resulting in a phase difference due to residual strain. It becomes easy.

The first to fourth cooling rolls 11, 12, 13, and 14 are, for example, double pipe spiral metal rolls, and the surface roughness of the third cooling roll 13 is Ra = 0.010 μm.
The surface of the first cooling roll 11 is covered with an elastic material 113. Examples of the elastic material 113 include fluorine rubber, nitrile rubber, and silicon rubber, and the hardness (conforming to JIS K6301 A type) is preferably 90 degrees or less and the thickness is preferably 3 mm or more, but is not limited thereto. .
Rotating shafts 112, 122, 132, 142 are provided at the centers of the first to fourth cooling rolls 11, 12, 13, 14. The manufacturing apparatus 1 includes a nip pressure control unit, and the nip pressure control unit can move the rotating shaft 132 of the third cooling roll 13 toward or away from the first cooling roll 11. By the movement, the linear pressure (nip pressure) applied between the belt 15 and the third cooling roll 13 is controlled to a predetermined pressure. The nip pressure may be controlled by moving the rotating shaft 112 of the first cooling roll 11 close to or away from the third cooling roll 13.
The nip pressure applied by the nip pressure control means is preferably 30 kg / cm or less, and more preferably 25 kg / cm or less. When the nip pressure exceeds 30 kg / cm, a bank (molten resin pool) is partially generated in the width direction of the sheet 20, and as a result, a stable low phase difference sheet 20 may not be obtained.

The warp correction roll 17 peels the sheet 20 adhered to the belt 15 and corrects the warp of the sheet 20 peeled from the belt 15. The straightening roll temperature control means controls the temperature of the peripheral surface 171 of the warp straightening roll 17 to (Tg−20 ° C.) or more and (Tg + 10 ° C.) or less. If the temperature of the peripheral surface 71 is less than (Tg−20 ° C.), sufficient warping correction effect cannot be obtained, and if it exceeds (Tg + 10 ° C.), the sheet 20 adheres to the peripheral surface 171 and deteriorates the appearance. The film may be stretched at the time of peeling from the warp correction roll 17 to cause phase difference unevenness.
Further, the warp correction roll 17 is arranged so that the peeling tension when peeling the sheet from the belt 15 becomes a predetermined value. The peeling tension is 0.1 kg / mm ² or less, preferably 0.05 kg / mm ² or less. When the peeling tension exceeds 0.1 kg / mm ² , retardation unevenness occurs in the sheet 20 due to stretching.

The sheet 20 manufactured by the manufacturing apparatus 1 as described above has a retardation (phase difference) in the in-plane direction of 20 nm or less, a surface roughness (Ra) of 0.05 μm or less, and a warpage rate of 0.2% or less. The total light transmittance is 88% or more.
The sheet thickness is 0.05 mm or more and 3.00 mm or less, preferably 0.1 mm or more and 2.5 mm or less. Here, if the sheet thickness is less than 0.05 mm, stable film formation may be difficult. On the other hand, if the sheet thickness exceeds 3.00 mm, it may be difficult to obtain a sheet 20 having a small residual phase difference due to a thickness factor. The thickness distribution is ± 5% or less, preferably within ± 2% with respect to the average value. If the thickness distribution exceeds ± 5%, the dependency of the phase difference on the incident angle increases, which is not preferable.

Next, a method for manufacturing the sheet 20 will be described.
First, a molten thermoplastic resin is extruded from the extrusion port 101 of the die 10 attached to the extruder and introduced between the belt 15 and the third cooling roll 13. The pressure between the third cooling roll 13 and the belt 15 is controlled to 30 kg / cm or less by the nip pressure control means. Further, the temperature of the peripheral surface 131 is adjusted by the roll temperature control means, and the temperature of the belt 15 is controlled by the belt temperature control means. As a result, the temperature of the peripheral surface 131 and the temperature of the belt 15 are controlled to (Tg−60 ° C.) or more and Tg or less, and the temperature difference is controlled within 30 ° C. Further, the temperature of the peripheral surface 171 is controlled to (Tg−20 ° C.) or more and (Tg + 10 ° C.) or less by the straightening roll temperature control means.
Thereafter, the sheet 20 is cooled while being conveyed by the belt 15 and is peeled off from the belt 15 to form the sheet 20. Here, the peeling tension when peeling the sheet 20 from the belt 15 is 0.1 kg / mm ² or less. The peeled sheet 20 is sent to the warp correction roll 17, and the warped state of the sheet 20 is corrected.

  The sheet 20 obtained in the present invention is made of a thermoplastic resin, and examples thereof include cyclic olefin resins, polycarbonates, and polystyrene. In particular, the cyclic olefin-based resin has thermoplasticity, and has a small optical anisotropy, a small photoelastic coefficient, and birefringence unlike other thermoplastic transparent resins such as polycarbonate and polystyrene. This is useful for various applications in the optical field. On the other hand, since polycarbonate is superior in heat resistance and impact resistance as compared with polystyrene, polymethyl methacrylate, and the like, it is useful for optical applications that require thinning.

  Such a cyclic olefin-based resin includes a polymer or copolymer (hereinafter referred to as “(co)” obtained from a monomer represented by the following general formula (1) (hereinafter also referred to as “specific monomer”). It is preferable to use a (co) polymer having a structural unit represented by the following general formula (1 ′), particularly preferably the above general formula (2). It is a (co) polymer having a structural unit.

(Wherein R ¹ to R ⁴ are a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or other monovalent organic group, and may be the same or different from each other. Any two of ¹ to R ⁴ may be bonded to each other to form a monocyclic or polycyclic structure, m is 0 or a positive integer, and p is 0 or a positive integer.)

(In the formula, definitions of R ¹ to R ⁴ , p and m are the same as those in the above formula (1).)

(In the formula, definitions of R ¹ to R ⁴ are the same as those in the above formula (1).)
Specifically, the polymers or copolymers shown in the following (a) to (e) can be suitably used.
(A) Ring-opening polymer of specific monomer (hereinafter also referred to as “specific ring-opening polymer”)
(B) a ring-opening copolymer (hereinafter, referred to as “copolymerizable cyclic monomer”), which is a specific monomer and a cyclic monomer copolymerizable with the specific monomer (hereinafter, also referred to as “copolymerizable cyclic monomer”). , Also referred to as “specific ring-opening copolymer”.)
(C) Saturated copolymer of specific monomer and unsaturated double bond-containing compound (hereinafter also referred to as “specific saturated copolymer”)
(D) Hydrogenated (co) polymer (e) specific ring-opening polymer or specific ring-opening copolymer (hereinafter also referred to as “specific ring-opening (co) polymer”) Hydrogenated (co) polymer obtained by cyclization of ring-opening (co) polymer by Friedel-Craft reaction and hydrogenation [specific monomer]
As a preferable specific monomer, in the above formula (1), R ¹ and R ³ are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and R ² and R ⁴ are a hydrogen atom or a monovalent organic group. And at least one of R ² and R ⁴ represents a polar group other than a hydrogen atom or a hydrocarbon group, m is an integer from 0 to 3, p is an integer from 0 to 3, and the value of m + p is 0. To 4, more preferably 0 to 2, particularly preferably 1.

Among the specific monomers, the specific monomer in which R ² and R ⁴ have a polar group represented by the following formula (3) has a high glass transition temperature (hereinafter also referred to as “Tg”), and moisture absorption. It is preferable at the point from which a cyclic olefin type thermoplastic resin with low property is obtained.

- (CH _{2) n} COOR ⁵ (3)
(In the formula, R ⁵ represents a hydrocarbon group having 1 to 12 carbon atoms, and n is an integer of 0 to 5.)
In the above formula (3), R ⁵ is preferably an alkyl group.

Moreover, the smaller the value of n, the higher the Tg of the resulting cyclic olefin-based resin, which is preferable. In particular, a specific monomer having n of 0 is preferable in terms of easy synthesis.
In the above formula (1), R ¹ or R ³ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, still more preferably an alkyl group having 1 to 2 carbon atoms, particularly A methyl group is preferred. Furthermore, it is preferable that this alkyl group is bonded to the same carbon atom as the carbon atom to which the polar group represented by the above formula (3) is bonded.

Moreover, the specific monomer whose m is 1 in the said Formula (1) is preferable at the point from which the thermoplastic resin composition with higher Tg is obtained.
As a specific example of the specific monomer represented by the above formula (1),
Bicyclo [2.2.1] hept-2-ene,
Tricyclo [5.2.1.0 ^2,6 ] -8-decene,
Tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
Pentacyclo ^{[6.5.1.1 3,6 .0 2,7 .0 9,13]} -4- pentadecene,
Pentacyclo ^{[7.4.0.1 2,5 .19 9,12 .0 8,13]} -3- pentadecene,
Tricyclo [4.4.0.1 ^2,5 ] -3-undecene,
5-methylbicyclo [2.2.1] hept-2-ene,
5-ethylbicyclo [2.2.1] hept-2-ene,
5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-methyl-5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-cyanobicyclo [2.2.1] hept-2-ene,
8 methoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-ethoxycarbonyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-n-propoxycarbonyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8 isopropoxycarbonyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-n-butoxycarbonyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-methyl-8-ethoxycarbonyl tetracyclo [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] -3- dodecene,
8-methyl-8-isopropoxycarbonyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-methyl -8-n-butoxycarbonyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
Dimethanooctahydronaphthalene,
Ethyltetracyclododecene,
6-ethylidene-2-tetracyclododecene,
Trimethanooctahydronaphthalene,
Pentacyclo ^{[8.4.0.1 2,5 .1 9,12 .0 8,13]} -3- hexadecene,
Heptacyclo ^{[8.7.0.1 3,6 .1 10,17 .1 12,15 .0} 2,7 .0 11,16] -4- eicosene,
Heptacyclo ^{[8.8.0.1 4,7 .1 11,18 .1 13,16 .0} 3,8 .0 12,17] -5- heneicosene,
5-ethylidenebicyclo [2.2.1] hept-2-ene,
8 ethylidene tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
5-phenylbicyclo [2.2.1] hept-2-ene,
8-phenyl tetracyclo [4.4.0.1 ^2,5 .17,10] -3- dodecene,
5-fluorobicyclo [2.2.1] hept-2-ene,
5-fluoromethylbicyclo [2.2.1] hept-2-ene,
5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-pentafluoroethylbicyclo [2.2.1] hept-2-ene,
5,5-difluorobicyclo [2.2.1] hept-2-ene,
5,6-difluorobicyclo [2.2.1] hept-2-ene,
5,5-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5,5,6-trifluorobicyclo [2.2.1] hept-2-ene,
5,5,6-tris (fluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6,6-tetrafluorobicyclo [2.2.1] hept-2-ene,
5,5,6,6-tetrakis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5-difluoro-6,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-difluoro-5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-fluoro-5-pentafluoroethyl-6,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-difluoro-5-heptafluoro-iso-propyl-6-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-chloro-5,6,6-trifluorobicyclo [2.2.1] hept-2-ene,
5,6-dichloro-5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-6-trifluoromethoxybicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-6-heptafluoropropoxybicyclo [2.2.1] hept-2-ene,
8-fluoro-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene, 8-fluoromethyl-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3-dodecene,
8 difluoromethyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-trifluoromethyl-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8 pentafluoroethyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8-difluoro-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,9-difluoro-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^{2,5 .17, 10]} -3- dodecene,
8-methyl-8-trifluoromethyl-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8,9- trifluoro-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8,9- tris (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8,9,9- tetrafluoro-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8,9,9- tetrakis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8-difluoro-9,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,9-difluoro-8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8,9- trifluoro-9-trifluoromethyl-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8,9- trifluoro-9-trifluoromethoxy-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,8,9- trifluoro-9-pentafluoro propoxy tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-Fluoro-8-pentafluoroethyl-9,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,9-difluoro-8-heptafluoro-iso- propyl-9-trifluoromethyl-tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8-Chloro -8,9,9- trifluoro tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8,9-dichloro-8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene,
8- (2,2,2-trifluoroethoxy-carbonyl) tetracyclo [4.4.0.1 ^2,5 .17,10] -3- dodecene,
, And the like 8-methyl-8- (2,2,2-trifluoroethoxy-carbonyl) tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene.

Of these specific monomers, 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3- dodecene, 8-ethylidene tetracyclo [4.4 .0.1 ^2,5 .1 ^7,10] -3-dodecene, 8-ethyl tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] -3-dodecene, pentacyclo [7.4 .0.1 ^2,5 .1 ^9,12 .0 ^8,13] -3-pentadecene are preferred in that the cyclic olefin resin having excellent heat resistance is obtained.

[Copolymerizable cyclic monomer]
As the copolymerizable cyclic monomer for obtaining a specific ring-opening copolymer, it is preferable to use a cycloolefin having 4 to 20 carbon atoms, particularly 5 to 12 carbon atoms. Specific examples thereof include cyclobutene and cyclopentene. , Cycloheptene, cyclooctene, tricyclo [5.2.1.0 ^2,6 ] -3-decene, 5-ethylidene-2-norbornene, dicyclopentadiene, and the like.

[Unsaturated double bond-containing compound]
Examples of the unsaturated double bond-containing compound for obtaining a specific saturated copolymer include polybutadiene, polyisoprene, styrene-butadiene copolymer, ethylene-nonconjugated diene copolymer,
An unsaturated hydrocarbon polymer containing a carbon-carbon double bond in the main chain such as polynorbornene can be used.

  The ratio of the specific monomer and the copolymerizable cyclic monomer or unsaturated double bond-containing compound used is the weight ratio of the specific monomer: copolymerizable cyclic monomer or unsaturated double bond-containing compound. It is preferably 100: 0 to 50:50, more preferably 100: 0 to 60:40.

  When the proportion of the copolymerizable cyclic monomer or unsaturated double bond-containing compound is excessive, the Tg of the resulting copolymer is lowered, and as a result, the heat resistance of the resin is lowered. It becomes difficult to obtain the highly efficient sheet 20.

(Ring-opening polymerization catalyst)
The ring-opening polymerization reaction of the specific monomer is performed in the presence of a metathesis catalyst. The metathesis catalyst includes at least one metal compound selected from a tungsten compound, a molybdenum compound, and a rhenium compound (hereinafter referred to as “component (a)”), and a Group 1 element (for example, Li, Na, K) of the periodic table. Etc.), Group 2 elements (eg Mg, Ca etc.), Group 12 elements (eg Zn, Cd, Hg etc.), Group 13 elements (eg B, Al etc.), Group 4 elements (eg Ti, Zr etc.) Or at least one compound selected from those having at least one element-carbon bond or the element-hydrogen bond (hereinafter referred to as a compound of a Group 14 element (for example, Si, Sn, Pb, etc.)). And “(b) component”), and may contain an additive (hereinafter referred to as “(c) component”) in order to enhance the catalytic activity. There.

Specific examples of suitable metal compounds constituting the component (a) include metal compounds described in JP-A-1-240517 such as WCl ₆ , MoCl ₅ , and ReOCl ₃ .

Specific examples of the compound constituting the component (b) include 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 _1.5 , (C ₂ H ₅ ) AlCl ₂ , methylalumoxane, LiH and the like, compounds described in JP-A-1-240517 can be mentioned.

  As the component (c), alcohols, aldehydes, ketones, amines and the like can be preferably used, but other compounds shown in JP-A-1-240517 can be used.

[Hydrogenation]
The cyclic olefin-based resin used in the present invention is obtained by hydrogenating a specific (co) ring-opening polymer in addition to the specific (co) ring-opening polymer and the specific saturated copolymer. A hydrogenated (co) polymer obtained by cyclizing a hydrogenated (co) polymer and a specific (co) ring-opened polymer by Friedel-Craft reaction and then hydrogenating it can be used.

  Since such a hydrogenated (co) polymer has excellent thermal stability, it can prevent its properties from being deteriorated by heating when it is molded or used as a product. it can.

  Here, the hydrogenation rate in the hydrogenated (co) polymer is usually 50% or more, preferably 70% or more, more preferably 90% or more, still more preferably 95% or more, and particularly preferably 97% or more.

The cyclic olefin resin used in the present invention preferably has an intrinsic viscosity (η _inh ) measured in chloroform at 30 ° C. of 0.2 to 5.0 dl / g.
The average molecular weight of the cyclic olefin-based resin is 8,000 to 100,000 in terms of polystyrene-equivalent number average molecular weight (Mn) measured by gel permeation chromatography (GPC), and 20,200 in weight average molecular weight (Mw). Those in the range of 000 to 300,000 are preferred.

Next, the manufacturing method of the sheet | seat 20 of this embodiment using the said manufacturing apparatus 1 is demonstrated.
First, the surface temperature of the belt 15 that directly contacts the sheet 20 and the first and third cooling rolls 11 and 13 is controlled. Specifically, the belt temperature control means controls the surface temperature of the belt 15 to be maintained at (Tg−60 ° C.) or more and Tg or less, and the roll temperature control means controls the first to fourth cooling rolls 11 to 11. 14 temperature control is performed.

  Then, the sheet 20 is extruded from the T die 10 of the extruder. And it introduce | transduces between the 1st and 3rd cooling rolls 11 and 13 so that the belt 15 currently contacting the 1st cooling roll 11 and the 3rd cooling roll 13 may contact substantially simultaneously. Further, the nip pressure control means controls the pressure between the first and third cooling rolls 11 and 13 to be 30 kg / cm or less. The sheet 20 is cooled by the belt 15 and the third cooling roll 13 while being conveyed by the belt 15. Here, also when the sheet 20 is conveyed, the roll temperature control means and the belt temperature control means control the temperature of the cooling roll and the belt 15 to (Tg−60 ° C.) or more and Tg or less, and the temperature difference therebetween. Control within 30 ° C.

[Effect of the embodiment]
Nip pressure control means for controlling the linear pressure applied to the manufacturing apparatus 1 between the belt 15 and the third cooling roll 13, roll temperature control means for controlling the temperature of the peripheral surface 131 of the third cooling roll 13, and warpage correction Straightening roll temperature control means for controlling the temperature of the peripheral surface 171 of the roll 17 and belt temperature control means for controlling the temperature of the belt 15 were provided.
Therefore, the belt temperature control unit controls the temperature of the belt 15 while the roll temperature control unit controls the temperature of the peripheral surface 131, and the nip pressure control unit further controls the linear pressure between the belt 15 and the third cooling roll 13. Therefore, a sheet having a small residual phase difference and surface roughness and high surface smoothness can be stably obtained. And the sheet | seat which has such a characteristic can be utilized suitably as an optical sheet used for a liquid crystal display element.

Further, the belt temperature controller 16 is provided with a cooling surface 161 for cooling the belt 15 from a position where the belt 15 and the first cooling roll 11 are separated from a position where the sheet 20 and the belt 15 are separated.
For this reason, while the sheet 20 is conveyed by the belt 15, it is possible to prevent a temperature difference between the surface of the sheet 20 that contacts the peripheral surface 131 and the surface that contacts the belt 15 from becoming small.

Further, a warp correction roll 17 for correcting the warp of the sheet peeled from the belt 15 was provided.
Therefore, the warp correction roll 17 can substantially prevent sheet warpage, which is an essential requirement for use in a liquid crystal display element.

Furthermore, the temperature of the peripheral surface 171 of the warp correction roll 17 was controlled to (Tg−20 ° C.) or more and (Tg + 10 ° C.) or less.
Therefore, since the temperature of the peripheral surface 171 is specified, the warp of the sheet 20 is sufficiently corrected. In addition, since the temperature of the peripheral surface 171 is specified, the sheet 20 can be prevented from adhering to the peripheral surface 171 and the appearance can be prevented from being deteriorated. Furthermore, it is possible to prevent the occurrence of retardation unevenness due to stretching when the sheet 20 peels from the correction roll 17.

Moreover, the distance from the extrusion port 101 of the die | dye 10 to between the belt 15 and the 3rd cooling roll 13 was 200 mm or less.
Therefore, fluttering of the sheet 20 extruded from the extrusion port 101 can be suppressed, and thickness unevenness can be prevented.

Then, in a state where the nip pressure between the belt 15 and the third cooling roll 13 was controlled to 30 kg / cm or less, a molten thermoplastic resin was introduced between the belt 15 and the third cooling roll 13.
Therefore, since the nip pressure is specified, it is possible to prevent a bank from being partially generated in the width direction of the sheet. Moreover, a stable low retardation sheet can be obtained.

Further, the temperature of the peripheral surface 131 and the temperature of the belt 15 were controlled to (Tg−60 ° C.) or more and Tg or less, and the temperature difference was controlled within 30 ° C.
Therefore, since the temperature of the peripheral surface 131 and the temperature of the belt are specified, it is possible to prevent the sheet from being rapidly cooled and to prevent a large residual phase difference from occurring when the sheet is clamped. Further, it is possible to prevent the occurrence of phase difference unevenness and thickness unevenness due to the tension at the time of peeling.
Moreover, since the temperature difference between the temperature of the peripheral surface 131 and the temperature of the belt 15 is specified, the temperature difference between the front and back of the sheet 20 is reduced, and it is possible to prevent the difference in shrinkage from occurring. Therefore, the sheet 20 having a small residual phase difference is obtained.

The peeling tension when peeling from the belt 15 was 0.1 kg / mm ² or less.
Therefore, since the peel strength is set to a specific value or less, it is possible to prevent the retardation of the sheet 20 from occurring.

The sheet 20 obtained by the production apparatus 1 has a retardation in the in-plane direction of 20 nm or less, a surface roughness (Ra) of 0.05 μm or less, a warpage rate of 0.2% or less, and a sheet thickness of 0.05 mm or more. It is 3.00 mm or less and the total light transmittance is 88% or more.
Therefore, since the sheet 20 has a small residual phase difference and high surface smoothness, it can be suitably used for a liquid crystal display element or the like.
For example, the sheet 20 can be used as a substrate sheet for a transparent electrode such as a touch panel. What was conventionally used as a glass / ITO electrode can be used instead of this sheet / ITO electrode. As a result, the strength can be increased, the weight can be reduced, and the cost can be reduced.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the content, such as an Example, at all.

[Example 1]
An extruder, extrusion process conditions, a belt machine, and first to fourth cooling rolls are shown below.
Single screw extruder: Φ75mm (L / D = 28)
Polymer filter: Leaf disk type, 5 inches, 20 sheets Filtration accuracy: Nominal 20 μm
Coat hanger die: 900mm width, lip opening 2mm
Extrusion conditions: Extruder cylinder part; 240 to 270 ° C., adapter part; 240 ° C., polymer filter part; 270 ° C., die; 245 ° C., extrusion rate: 85 kg / h, sheet take-up speed: 1.6 m / min
Belt machine; stainless steel belt; 0.8mm thickness, width 900mm, belt surface roughness Ra = 0.015μm
A first cooling roll; a roll (Φ600) coated with nitrile rubber (NBR) having a thickness of 10 mm and JIS-A 75 °;
Second cooling roll; double pipe spiral metal roll (Φ600),
A third cooling roll; a double pipe spiral roll (Φ600) having a surface roughness Ra = 0.010 μm;
Fourth cooling roll; double pipe spiral metal roll (Φ600)
Next, a sheet manufacturing method will be described.
First, as a thermoplastic resin, a cyclic olefin copolymer represented by the following formula (4) obtained by copolymerization of norbornene and ethylene with a metallocene catalyst (MFR = 4 g / 10 min (260 ° C.), Tg = 158 ° C. “TOPAS (registered trademark) 6015” manufactured by Plastics Co., Ltd.) was dried in a hot air dryer at 120 ° C. for 12 hours.

(4)

This was supplied to the hopper of the extruder, and the molten resin was extruded from the extrusion port (die lip).
The extruded molten resin film is introduced between the belt and a third cooling roll disposed opposite to the first cooling roll via the belt, and then cooled while being conveyed by the belt and peeled off from the belt. I let you. At this time, temperature control was performed from the back surface of the belt by the belt temperature control means, and the belt temperature was kept at a predetermined temperature. Thereafter, the cyclic olefin-based resin sheet was brought into contact with a warp correction roll whose surface temperature was controlled to produce a sheet substantially free from warpage.
Note that the roll nip pressure, the surface temperature of the third cooling roll, the back surface temperature of the belt, the distance from the extrusion port of the extrusion die to the space between the first and third cooling rolls (air gap), peeling tension, warpage correction roll The temperature and sheet thickness were set as shown in Table 1. The temperature difference shown in Table 1 is the difference between the temperature of the surface of the third cooling roll and the temperature of the back surface of the belt.

[Example 2 to Example 6, Comparative Example 1 to Comparative Example 7]
In Example 2 to Example 6 and Comparative Example 1 to Comparative Example 7, sheets were produced in the same manner as in Example 1 based on the conditions in Tables 1 and 2, respectively. In Table 2, * 1 indicates that measurement is not possible, and * 2 indicates that measurement is not possible due to sheet deformation.

As can be seen from Tables 1 and 2, in Comparative Example 1, since the nip pressure exceeded 30 kg / cm, a sheet having a retardation value larger than 20 nm was obtained. Similarly, in Comparative Example 2, the temperature difference between the temperature of the third cooling roll and the back surface temperature of the metal belt was 80 ° C., and the retardation value was relatively large. In Comparative Example 3, the air gap exceeded 200 mm, and in Comparative Example 4, the peel tension exceeded 0.1 kg / mm ² , so that the retardation value was relatively large.
Further, in Comparative Examples 5 and 6, since the temperature of the warp correction roll is outside the range of (Tg−20 ° C.) or more and (Tg + 10 ° C.) or less, the warpage rate becomes large. It was not possible to measure.
Moreover, in Comparative Example 7, since the temperature difference between the surface temperature of the third cooling roll and the belt back surface temperature exceeded 30 ° C., a sheet having a retardation value larger than 20 nm was obtained.
On the other hand, in Examples 1 to 6, since the roll nip pressure, the surface temperature of the third cooling roll, the temperature of the back surface of the belt, the air gap, the peeling tension, and the temperature of the warp correction roll were specified, the retardation was 20 nm or less. A sheet having a surface roughness (Ra) of 0.05 μm or less, a warpage rate of 0.2% or less, and a total light transmittance of 88% or more was obtained.

  According to the thermoplastic resin sheet manufacturing apparatus and method of the present invention, it is possible to stably manufacture a sheet having a small residual retardation and high surface smoothness.

Schematic of the manufacturing apparatus used with the manufacturing method of the thermoplastic resin sheet which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ...... Manufacturing apparatus 10 ... Die 11 ... 1st cooling roll 12 ... 2nd cooling roll 13 ... 3rd cooling roll 14 ... 4th cooling roll 15 ... Belt 16 ... Belt Temperature controller 17 …… War correction roll 20 …… Sheet

Claims (14)

The surface of the first cooling roll whose surface is coated with an elastic material, and a metal belt having a mirror surface that is wound between the second cooling roll,
A third cooling roll disposed opposite to the first cooling roll via the metal belt,
A molten thermoplastic resin is extruded from a die attached to an extruder, introduced between the metal belt and the third cooling roll, and then cooled while being conveyed by the metal belt and made of the metal. A thermoplastic resin sheet manufacturing apparatus for forming a thermoplastic resin sheet by peeling from a belt,
Nip pressure control means for controlling linear pressure applied between the metal belt and the third cooling roll;
Roll temperature control means for controlling the temperature of the surface of the third cooling roll;
Belt temperature control means for controlling the temperature of the metal belt;
An apparatus for producing a thermoplastic resin sheet, comprising: The said nip pressure control means controls the said linear pressure to 30 kg / cm or less. The manufacturing apparatus of the thermoplastic resin sheet of Claim 1 characterized by the above-mentioned. The apparatus for producing a thermoplastic resin sheet according to claim 1 or 2, further comprising a warp correction roll for correcting the warp of the thermoplastic resin sheet peeled off from the metal belt. The said curvature correction roll peels the said sheet | seat from the said metal belt with the peeling tension of 0.1 kg / mm < ² > or less. The manufacturing apparatus of the thermoplastic resin sheet of Claim 3 characterized by the above-mentioned. The temperature of the surface of the said curvature correction roll is controlled by the correction roll temperature control means. The manufacturing apparatus of the thermoplastic resin sheet as described in any one of Claim 1 to 4 characterized by the above-mentioned. The said straightening roll temperature control means controls the temperature of the surface of the said curvature straightening roll to (Tg-20 degreeC) or more and (Tg + 10 degreeC) or less. The manufacturing apparatus of the thermoplastic resin sheet of Claim 5 characterized by the above-mentioned. . The distance from the extrusion port of the die to the metal belt and the third cooling roll is 200 mm or less. Thermoplastic according to any one of claims 1 to 6, Resin sheet manufacturing equipment. The temperature of the surface of the third cooling roll controlled by the roll temperature control means and the temperature of the metal belt controlled by the belt temperature control means are (Tg−60 ° C.) or more and Tg or less, respectively, and the temperature difference between them. Is within 30 ° C. The thermoplastic resin sheet producing apparatus according to claim 1, wherein the temperature is within 30 ° C. The surface of the first cooling roll whose surface is coated with an elastic material, and a metal belt having a mirror surface that is wound between the second cooling roll,
A third cooling roll disposed opposite to the first cooling roll via the metal belt;
Using a manufacturing apparatus equipped with
A molten thermoplastic resin is extruded from a die attached to an extruder, introduced between the metal belt and the third cooling roll, and then cooled while being conveyed by the metal belt and made of the metal. A method for producing a thermoplastic resin sheet, wherein a thermoplastic resin sheet is formed by peeling from a belt,
Introducing a molten thermoplastic resin between the metal belt and the third cooling roll in a state where the nip pressure between the metal belt and the third cooling roll is controlled to 30 kg / cm or less; ,
In a state where the temperature of the surface of the third cooling roll and the temperature of the metal belt are controlled, a step of conveying the thermoplastic resin by the metal belt;
A method for producing a thermoplastic resin sheet, comprising: The temperature of the surface of the third cooling roll and the temperature of the metal belt are controlled to (Tg-60 ° C) or more and Tg or less, and the temperature difference is controlled within 30 ° C. 10. A method for producing a thermoplastic resin sheet according to 9. The method for producing a thermoplastic resin sheet according to claim 9 or 10, wherein a peeling tension at the time of peeling from the metal belt is 0.1 kg / mm ² or less. The method for producing a thermoplastic resin sheet according to any one of claims 9 to 11, wherein the thermoplastic resin sheet separated from the metal belt is conveyed by a warp correction roll. . The method for producing a thermoplastic resin sheet according to claim 12, wherein the temperature of the surface of the warp correction roll is controlled to (Tg−20 ° C.) or more and (Tg + 10 ° C.) or less. The retardation in the in-plane direction is 20 nm or less, the surface roughness (Ra) is 0.05 μm or less, the warpage rate is 0.2% or less, the sheet thickness is 0.05 mm or more and 3.00 mm or less, and the total light transmittance is 88. % Or more thermoplastic resin sheet.