JP2017165892A - Transparent resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion film which is excellent in uniformity of thickness, has no defect of the film, prevents occurrence of breaking of the film at the time of slit and winding up and curling at the time of a roll-shape storage, and is excellent in productivity.SOLUTION: A film has a structural unit derived from a dihydroxy compound having a hexahydrofurofuran skeleton represented by formula (1), is obtained by molding a polycarbonate resin satisfying the following (a) to (d): (a): melt viscosity at 240°C is 1,300 Pa s or less; (b): Tg is 115°C or higher and lower than 150°C; (c) flexural modulus is 2,900 or more and less than 3,300 MPa; and (d) 10-700 wt.ppm of the compound represented by formula (3) is contained, and has a thickness of 5-40 μm.SELECTED DRAWING: None

Description

  The present invention uses a specific polycarbonate, is excellent in thickness uniformity, has no film defects, does not break when slitting, does not cause winding or curling when stored in a roll, and has a phase difference. The present invention relates to a small film with excellent productivity.

  Various image display devices including a liquid crystal display device need to dispose a polarizing plate on one side or both sides of a substrate on which an image display panel is formed because of the image forming method. In general, a polarizing plate is made by bonding a cellulose film such as triacetyl cellulose as a polarizer protective film to a polarizer made of a polyvinyl alcohol film containing iodine via an adhesive or a pressure-sensitive adhesive. It has been.

  Cellulose-based films do not have sufficient heat-and-moisture resistance, so a polarizing plate using this as a polarizer protective film can be used in a high-humidity and heat environment, or the entire image display device can be made thin so that the distance from a heat source such as a light source If the structure becomes close, the film may expand and deform, or the polarizing plate characteristics such as polarization degree and color difference may be impaired. In addition, since the cellulose-based film causes a phase difference with respect to an incident angle in an oblique direction, the viewing angle characteristic may be significantly affected particularly in a large liquid crystal image display device.

  In order to solve the problem of such a cellulose film, a film made of a methacrylic resin or a methacrylic resin having a lactone ring structure has been proposed as a material excellent in heat resistance and optical transparency. (Patent Documents 1 to 3)

  On the other hand, in Patent Document 4, a film using a polycarbonate resin having a structural unit derived from isosorbide is proposed, and by forming a polycarbonate resin having a structural unit derived from isosorbide having a specific viscosity, a relatively retardation is obtained. It is disclosed that a film having a small expression can be obtained.

JP 2000-356714 A JP 2002-258051 A JP 2001-151814 A JP 2009-079191 A

However, when film-forming a polycarbonate resin having a structural unit derived from isosorbide, not only is it difficult to maintain the thickness accuracy of the film, but also film contamination due to roll contamination during film formation or when slitting. When the film is broken or stored in a roll, there are problems such as winding and curling of the film, and it is difficult to provide a high-quality film with high productivity.
The purpose of the present invention is to eliminate the above-mentioned conventional problems, using a specific polycarbonate resin, excellent in thickness uniformity, without film defects, when the film is broken at the time of slitting, and stored in a roll form An object of the present invention is to provide a film that does not cause film tightening or curling, has a small phase difference, and is excellent in productivity.

［２］波長５８９ｎｍでの厚み位相差（Ｒｔｈ（５８９））及び面内位相差（Ｒ（５８９））がともに１０ｎｍ以下である、［１］に記載のフィルム。 As a result of intensive studies to solve the above problems, the present inventors have used a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1) that satisfies specific conditions. Extrusion with excellent uniformity of thickness, no film defects, no tearing when slitting, no tightness or curl when stored in roll form, small phase difference and excellent productivity We have found that a film is provided and have arrived at the present invention. That is, the gist of the present invention resides in the following [1] and [2].
[1] A film formed by molding a polycarbonate resin having a structural unit derived from a dihydroxy compound represented by the following formula (1) and satisfying the following (a) to (d), and having a thickness of 5 μm to 40 μm The following films.
(A) The melt viscosity measured with a capillary rheometer at 240 ° C. is 1300 Pa · s or less under the condition of a shear rate of 91.2 sec ⁻¹ (b) The glass transition temperature Tg is 115 ° C. or more and less than 150 ° C. (c ) Flexural modulus measured in accordance with ISO178 is 2900 MPa or more and less than 3300 MPa (d) Contains 10 ppm to 700 ppm by weight of a compound represented by the following formula (3)

[2] The film according to [1], wherein both the thickness retardation (Rth (589)) and in-plane retardation (R (589)) at a wavelength of 589 nm are 10 nm or less.

  According to the present invention, a specific polycarbonate is used, the thickness uniformity is excellent, there is no film defect, no tearing occurs when slitting, no winding tightening or curling occurs when stored in roll form, An extruded film having a small phase difference and excellent productivity can be provided.

  DESCRIPTION OF EMBODIMENTS Embodiments of the present invention will be described in detail below. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention. It is not limited to the contents.

[Polycarbonate resin]
The polycarbonate resin according to the present invention is a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1), and the melt viscosity measured with a capillary rheometer at 240 ° C. has a shear rate of 91.2 sec ⁻ A compound represented by the following formula (3) having a glass transition temperature Tg of 115 ° C. or higher and lower than 150 ° C., a flexural modulus measured according to ISO 178 of 2900 MPa or higher and lower than 3300 MPa under the condition ¹ : It contains 10 ppm to 700 ppm by weight.

<Melt viscosity>
The melt viscosity of the polycarbonate resin according to the present invention measured by a capillary rheometer at 240 ° C. is 1300 Pa · s or less under the condition of a shear rate of 91.2 sec ⁻¹ . In order to make the effect of the present invention more excellent, the lower limit of the melt viscosity is preferably 400 Pa · s or more, more preferably 500 Pa · s or more, more preferably 600 Pa · s under the condition of a shear rate of 91.2 sec ^−1. The above is more preferable, and 700 Pa · s or more is particularly preferable. On the other hand, the upper limit is preferably 1200 Pa · s or less, more preferably 1100 Pa · s or less, and even more preferably 1000 Pa · s or less under the condition of a share rate of 91.2 sec ⁻¹ . When the melt viscosity of the polycarbonate resin is within this range, not only a film having a low thickness retardation can be obtained, but also a film having a uniform thickness with high film thickness accuracy can be obtained. Examples of the method of setting the melt viscosity of the polycarbonate resin according to the present invention in the above range include controlling the molecular weight of the resin. Examples of the method of setting the molecular weight of the resin in the above range include an example of means in which temperature and pressure adjustment in the production stage is effective as described in detail in the section of the production method of polycarbonate resin described later.
<Glass transition temperature>
The glass transition temperature of the polycarbonate resin according to the present invention is 115 ° C. or higher and lower than 150 ° C. In order to make the effect of the present invention more excellent, the lower limit of the glass transition temperature is preferably 120 ° C. or higher, more preferably 125 ° C. or higher. When the glass transition temperature of the polycarbonate resin is above the lower limit, even when the film is 40 μm or less, even if it is exposed to high temperature and high humidity during storage, the film will be wavy and warped. Can be prevented. Further, the upper limit of the glass transition temperature is preferably less than 145 ° C, more preferably less than 140 ° C. When the glass transition temperature of the polycarbonate resin is equal to or lower than the upper limit, it is possible to prevent insufficient cooling of gear marks and the like generated during film formation.
Examples of the method of setting the glass transition temperature of the polycarbonate resin according to the present invention in the above range include increasing the proportion of structural units derived from the dihydroxy compound represented by the general formula (1) in the polycarbonate resin, Examples include a method of selecting a high alicyclic dihydroxy compound or increasing the proportion of structural units derived from an aromatic dihydroxy compound. The dihydroxy compound represented by the general formula (1) in the polycarbonate resin The ratio of the structural unit derived from is more preferably 60% by weight or more.

<Bending elastic modulus>
The flexural modulus measured according to ISO 178 of the polycarbonate resin according to the present invention is 2900 MPa or more and less than 3300 MPa. In order to make the effect of the present invention more excellent, the lower limit of the flexural modulus is preferably 3000 MPa or more, and more preferably 3050 MPa or more. When the flexural modulus of the polycarbonate resin is equal to or more than the lower limit, it is possible to prevent the film from being tightened or wrinkled when the film is wound around the core. The upper limit of the flexural modulus is preferably less than 3250 MPa, and more preferably less than 3200 MPa. When the elastic modulus of the polycarbonate resin is less than the above upper limit, when cutting unnecessary portions of the film called so-called “Mimi” by the slit of the film when the polycarbonate resin is used as a film, up to the regular product part (effective part) It is possible to prevent the tear from propagating.
As a method of setting the flexural modulus of the polycarbonate resin within the above range, the proportion of the structural unit derived from the dihydroxy compound represented by the general formula (1) in the polycarbonate resin (A) is increased, or the alicyclic is used as a copolymerization component. Examples include a method of selecting a formula dihydroxy compound or increasing the proportion of structural units derived from an aromatic dihydroxy compound, and the like, but derived from the dihydroxy compound represented by the general formula (1) in the polycarbonate resin. The proportion of structural units is more preferably 60% by weight or more.

<Compound represented by Formula (3) and method for controlling content>
The polycarbonate resin according to the present invention contains a special oligomer component represented by the following formula (3). If the amount is too small, it is necessary to apply excessive heat or increase the reaction residence time in the purification stage, which may cause deterioration of the color tone of the polymer, and the above range is preferable. If the amount is too large, there will be a problem of contamination of the apparatus during film formation, and a problem of poor appearance of the film.
The content of the compound represented by the following formula (3) in the polycarbonate resin according to the present invention is 10 ppm by weight or more as a lower limit, preferably 15 ppm by weight or more, and particularly preferably 20 ppm by weight or more. preferable. The upper limit is 700 ppm by weight or less, preferably 650 ppm by weight or less, and particularly preferably 600 ppm by weight or less. When the content of the compound represented by the following formula (3) in the polycarbonate resin is within the above range, the compound represented by the following formula (3) does not contaminate the roll during molding, and film formation is caused thereby. Periodic defects of the film can be prevented. In order to adjust the content of the compound represented by the following formula (3), the ratio (A / B) of the number of phenyl group terminals (A) to the total number of terminals (B) during polycarbonate resin production is By making it 98% or less, generation | occurrence | production of the compound represented by following formula (3) can be suppressed. Furthermore, generation | occurrence | production can be suppressed by making the pressure in a final polymerization tank into 1 KPa or less, or making polymerization time in temperature higher than 220 degreeC into less than 2 hours. In particular, the devolatilization efficiency can be drastically improved by making the final polymerization tank a horizontal reaction tank. Moreover, content of the compound represented by following formula (3) can be adjusted by performing devolatilization from a vacuum vent with an extruder, or performing water injection in the case of devolatilization.

As will be described later, the polycarbonate resin according to the present invention is usually obtained by polycondensing a dihydroxy compound, a carbonic acid diester and a catalyst under melting. In this polycondensation reaction, a monohydroxy compound is generated as a leaving component from the carbonic acid diester. For example, when diphenyl carbonate is used as the carbonic acid diester, the monohydroxy compound produced is phenol. At this time, if the residual amount of the monohydroxy compound in the obtained polycarbonate resin is large, there may be a problem of contamination of the apparatus and odor during molding. The upper limit of the residual amount of the monohydroxy compound in the polycarbonate resin of the present invention is 700 ppm by weight or less, more preferably 500 ppm by weight or less, and particularly preferably 300 ppm by weight or less. At the time of production of the polycarbonate resin, by using an appropriate amount of a specific phosphorus compound that becomes a catalyst deactivator as described later, and further sufficiently performing devolatilization treatment, the residual amount of the monohydroxy compound in the polycarbonate resin is reduced, And generation | occurrence | production under a heating can be suppressed. Details of the method for measuring the amount of the monohydroxy compound in the polycarbonate resin are described in the Examples section. In addition, the lower limit is not limited, but is usually 0.01 ppm by weight or less, more preferably 0.1 ppm by weight or less, and particularly preferably 1 ppm by weight or less. If the amount is too small, it is necessary to apply excessive heat or increase the reaction residence time in the purification stage, which may cause deterioration of the color tone of the polymer, and the above range is preferable.

また、ポリカーボネート樹脂のフェニル基末端の存在数（Ａ）の全末端数（Ｂ）に対する割合（Ａ／Ｂ）は、７６％以上の範囲であることが好ましく、７７％以上の範囲であることが特に好ましい。また、９６％以下の範囲であることが好ましく、９５％以下の範囲であることが特に好ましい。
フェニル基末端の存在数（Ａ）の全末端数（Ｂ）に対する割合（Ａ／Ｂ）が、７５％より少ないと、射出成形の際に成形品にシルバーと呼ばれる外観不良、押出成形での気泡が発生しやすくなる。また、フェニル基末端の存在数（Ａ）の全末端数（Ｂ）に対する割合（Ａ／Ｂ）が９８％より多いと、押出成形での外観不良は減る傾向にある。また、９８％より多いポリカーボネート樹脂を得ようとすると、重合条件を過酷にしたり、長時間の反応が必要となり結果的に、ポリカーボネート樹脂の劣化に繋がり、色調が悪いものしか得られない可能性が非常に高い。 <End group structure of polycarbonate resin>
It is preferable to use diphenyl carbonate as the carbonic acid diester, as described in detail in the method for producing a polycarbonate resin described later. In this case, the total number of terminals (B) of the number of existing terminal groups (A) of the terminal group represented by the following structural formula (2) (hereinafter sometimes referred to as “phenyl group terminal”) of the polycarbonate resin to be produced. The ratio (A / B) to is in the range of 75% or more and less than 98%.

In addition, the ratio (A / B) of the number (A) of phenyl group terminals present in the polycarbonate resin to the total number of terminals (B) is preferably in the range of 76% or more, and in the range of 77% or more. Particularly preferred. Moreover, it is preferable that it is the range of 96% or less, and it is especially preferable that it is the range of 95% or less.
If the ratio (A / B) of the number of phenyl group terminals (A) to the total number of terminals (B) is less than 75%, the molded product has a poor appearance called silver during injection molding, and bubbles in extrusion molding. Is likely to occur. Moreover, when the ratio (A / B) of the number of phenyl group terminals (A) to the total number of terminals (B) is more than 98%, the appearance defect in extrusion molding tends to decrease. Further, if it is attempted to obtain more than 98% polycarbonate resin, the polymerization conditions may be harsh or a long reaction will be required. As a result, the polycarbonate resin may be deteriorated, and only a poor color tone may be obtained. Very expensive.

The method for adjusting the ratio (A / B) of the number of phenyl group terminals (A) in the polycarbonate resin to the total number of terminals (B) is not particularly limited, but for example, carbonic acid with respect to all dihydroxy compounds used in the reaction. Adjust the amount ratio of diester within a range where a desired high molecular weight product can be obtained, remove residual monomer from the reaction system by degassing at the latter stage of the polymerization reaction, increase the stirring efficiency of the reactor at the latter stage of the polymerization reaction, etc. Thus, by increasing the reaction rate, the ratio (A / B) of the number of existing phenyl groups (A) to the total number of terminals (B) can be adjusted to the above-described range.
The proportion of the phenyl group terminal in the polycarbonate resin can be calculated by measuring ¹ H-NMR spectrum using deuterated chloroform to which TMS is added as a measurement solvent with an NMR spectrometer.

  In addition, the usage rate of the dihydroxy compound represented by Formula (1) and the other dihydroxy compound used as needed is the ratio of the structural unit derived from each dihydroxy compound which comprises the polycarbonate resin used by this invention. Adjust accordingly.

[Production method of polycarbonate resin]
The method for producing the polycarbonate resin according to the present invention will be described in detail.

<Raw material>
(Dihydroxy compound)
The polycarbonate resin according to the present invention is a polycarbonate resin containing a structural unit derived from a dihydroxy compound represented by the following formula (1).

  In addition to the structural unit derived from the dihydroxy compound represented by the above formula (1), the polycarbonate resin according to the present invention may be a dihydroxy compound represented by the following formula (4) or a formula (5) below, if necessary. One or more selected from the group consisting of a dihydroxy compound represented by the following formula (6), a dihydroxy compound represented by the following formula (7), and a dihydroxy compound represented by the following formula (8) Structural units derived from the dihydroxy compound can be included.

HO—R ⁵ —OH (5)
(In the above formula (5), R ⁵ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)

HO—CH ₂ —R ⁶ —CH ₂ —OH (6)
(In the above formula (6), R ⁶ represents a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms.)

_{^{H- (O-R 7) p}} -OH (7)
(In the above formula (7), ^{R 7} represents a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, p is an integer from 2 to 100.)

HO—R ⁸ —OH (8)
(In the above formula (8), R ⁸ represents a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms.)

  In the following, the carbon number of various groups means the total number of carbon atoms including the carbon number of the substituent when the group has a substituent.

[Dihydroxy Compound Represented by Formula (1)]
The polycarbonate resin according to the present invention includes a structural unit derived from the dihydroxy compound represented by the above formula (1).

Examples of the dihydroxy compound represented by the above formula (1) include anhydrous sugar alcohols such as isosorbide, isomannide and isoidet which are in a stereoisomeric relationship. These may be used individually by 1 type and may be used in combination of 2 or more type. Among these dihydroxy compounds, isosorbide obtained by dehydrating condensation of sorbitol produced from various starches that are abundant as resources and are readily available is easy to obtain and manufacture, optical properties, moldability From the viewpoint of the above, it is most preferable.

[Dihydroxy compounds represented by formulas (4) to (8)]
The polycarbonate resin according to the present invention includes, as necessary, a dihydroxy compound represented by the above formula (4), a dihydroxy compound represented by the following formula (5), a dihydroxy compound represented by the following formula (6), A structural unit derived from one or more dihydroxy compounds selected from the group consisting of a dihydroxy compound represented by the formula (7) and a dihydroxy compound represented by the following formula (8) can be included.
The dihydroxy compound represented by the above formula (4) has a cyclic ether structure in the molecule, and is a compound called spiroglycol.

<Dihydroxy compound represented by Formula (5)>
The dihydroxy compound represented by the formula (5) is an alicyclic dihydroxy compound having a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, preferably 4 to 18 carbon atoms, in R ⁵ . Here, when R ⁵ has a substituent, examples of the substituent include substituted or unsubstituted alkyl groups having 1 to 12 carbon atoms. When the alkyl group has a substituent, examples of the substituent include an alkoxy group such as a methoxy group, an ethoxy group, and a propoxy group, and an aryl group such as a phenyl group and a naphthyl group.

  Since this dihydroxy compound has a ring structure, it is possible to increase the toughness of a molded product when the obtained polycarbonate resin is molded, and in particular, the toughness when molded into a film can be increased.

The cycloalkylene group for R ⁵ is not particularly limited as long as it is a hydrocarbon group having a ring structure, and may be a bridge structure having a bridgehead carbon atom. From the viewpoint that production of the dihydroxy compound is easy and the amount of impurities can be reduced, the dihydroxy compound represented by the formula (5) is a compound containing a 5-membered ring structure or a 6-membered ring structure, that is, R ⁵ is A dihydroxy compound which is a substituted or unsubstituted cyclopentylene group or a substituted or unsubstituted cyclohexylene group is preferred. If it is such a dihydroxy compound, the heat resistance of the polycarbonate resin obtained can be made high by including a 5-membered ring structure or a 6-membered ring structure. The 6-membered ring structure may be fixed in a chair shape or a boat shape by a covalent bond.

Among them, the dihydroxy compound represented by the formula (5) is preferably various isomers in which R ⁵ is represented by the following formula (9). Here, in formula (9), R ¹¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms. When R ¹¹ is a C 1-12 alkyl group having a substituent, examples of the substituent include alkoxy groups such as a methoxy group, an ethoxy group, and a propoxy group, and aryl groups such as a phenyl group and a naphthyl group. It is done.

More specifically, examples of the dihydroxy compound represented by the formula (5) include tetramethylcyclobutanediol, 1,2-cyclopentanediol, 1,3-cyclopentanediol, 1,2-cyclohexanediol, 1,3. -Cyclohexanediol, 1,4-cyclohexanediol, 2-methyl-1,4-cyclohexanediol, tricyclodecanediols, pentacyclodiols and the like can be mentioned, but not limited thereto.
These may be used alone or in combination of two or more.

<Dihydroxy compound represented by formula (6)>
The dihydroxy compound represented by the formula (6) is an alicyclic dihydroxy compound having a substituted or unsubstituted cycloalkylene group having 4 to 20 carbon atoms, preferably 3 to 18 carbon atoms, in R ⁶ . Here, when R ⁶ has a substituent, examples of the substituent include a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms. When the alkyl group has a substituent, the substituent includes , Alkoxy groups such as methoxy group, ethoxy group and propoxy group, and aryl groups such as phenyl group and naphthyl group.

  Since this dihydroxy compound has a ring structure, it is possible to increase the toughness of a molded product when the obtained polycarbonate resin is molded, and in particular, the toughness when molded into a film can be increased.

The cycloalkylene group for R ⁶ is not particularly limited as long as it is a hydrocarbon group having a ring structure, and may be a bridge structure having a bridgehead carbon atom. From the viewpoint that production of the dihydroxy compound is easy and the amount of impurities can be reduced, the dihydroxy compound represented by the formula (6) is a compound having a 5-membered ring structure or a 6-membered ring structure, that is, R ⁶ is A dihydroxy compound which is a substituted or unsubstituted cyclopentylene group or a substituted or unsubstituted cyclohexylene group is preferred. If it is such a dihydroxy compound, the heat resistance of the polycarbonate resin obtained can be made high by including a 5-membered ring structure or a 6-membered ring structure. The 6-membered ring structure may be fixed in a chair shape or a boat shape by a covalent bond. Among the dihydroxy compounds represented by the formula (6), it is preferable that R ⁶ is various isomers represented by the formula (9).

More specifically, as the dihydroxy compound represented by the formula (6), 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 3,8-bis (hydroxy) Methyl) tricyclo [5.2.1.0 ^2.6 ] decane, 3,9-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane, 4,8-bis (hydroxymethyl) Examples include tricyclo [5.2.1.0 ^2.6 ] decane, 4,9-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane, and the like, but are not limited thereto. It is not a thing.

These may be used alone or in combination of two or more. That is, although these dihydroxy compounds may be obtained as a mixture of isomers for production reasons, they can be used as they are as an isomer mixture. For example, 3,8-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane, 3,9-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane, 4,8-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane and a mixture of 4,9-bis (hydroxymethyl) tricyclo [5.2.1.0 ^2.6 ] decane Can be used.

  Of the specific examples of the dihydroxy compound represented by the formula (6), cyclohexanedimethanols are particularly preferable. From the viewpoint of easy availability and ease of handling, 1,4-cyclohexanedimethanol, 1 1,3-cyclohexanedimethanol and 1,2-cyclohexanedimethanol are preferred.

<Dihydroxy compound represented by Formula (7)>
The dihydroxy compound represented by the formula (7) is a compound having a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, preferably 2 to 5 carbon atoms, in R ⁷ . p is an integer of 2 to 100, preferably 6 to 50, more preferably 12 to 40.

Specific examples of the dihydroxy compound represented by the formula (7) include diethylene glycol, triethylene glycol, and polyethylene glycol (molecular weight: 150 to 4000), but are not limited thereto. The dihydroxy compound represented by the formula (7) is preferably polyethylene glycol having a molecular weight of 300 to 2000, and particularly preferably polyethylene glycol having a molecular number of 600 to 1500.
These may be used alone or in combination of two or more.

<Dihydroxy compound represented by formula (8)>
The dihydroxy compound represented by the formula (8) is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms, for R ⁸ . When the alkylene group for R ⁸ has a substituent, examples of the substituent include an alkyl group having 1 to 5 carbon atoms.

Among the dihydroxy compounds represented by the above formula (8), specific examples of the dihydroxy compound in which R ⁸ is a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms include ethylene glycol, propylene glycol, 1, Examples include 4-butanediol and 1,6-hexanediol, but are not limited thereto.

  Among these dihydroxy compounds, 1,3-propanediol, 1,6-propanediol are preferred from the viewpoint of availability, ease of handling, high reactivity during polymerization, and hue of the obtained polycarbonate resin. Hexanediol is preferred. From the viewpoint of heat resistance, spiroglycol having an acetal ring is preferable. These may be used alone or in combination of two or more depending on the required performance of the polycarbonate resin to be obtained.

  The polycarbonate resin according to the present invention includes a structural unit derived from the dihydroxy compound represented by the formula (4), a structural unit derived from the dihydroxy compound represented by the formula (5), and the formula (6). Among the structural units derived from the dihydroxy compound represented, the structural unit derived from the dihydroxy compound represented by the formula (7), and the structural unit derived from the dihydroxy compound represented by the formula (8), the above formula ( It is preferable that the structural unit derived from the dihydroxy compound represented by 6) and / or the structural unit derived from the dihydroxy compound represented by the formula (7) is included. Since there is little decomposition | disassembly, it is more preferable that the structural unit derived from the dihydroxy compound represented by said Formula (6) is included.

[Other dihydroxy compounds]
In the polycarbonate resin according to the present invention, the structural unit derived from the dihydroxy compound represented by the above formulas (4) to (8) may be replaced with a structural unit derived from another dihydroxy compound as necessary.

Examples of other dihydroxy compounds include bisphenols, ethylene oxide (EO) additions of bisphenols, and fluorene compounds.
Examples of bisphenols include 2,2-bis (4-hydroxyphenyl) propane (= bisphenol A), 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, and 2,2-bis ( 4-hydroxy-3,5-diethylphenyl) propane, 2,2-bis (4-hydroxy- (3,5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) ) Propane, 2,2-bis (4-hydroxyphenyl) pentane, 2,4'-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-5-nitrophenyl) methane, 1,1 -Bis (4-hydroxyphenyl) ethane, 3,3-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydride) Roxyphenyl) cyclohexane, bis (4-hydroxyphenyl) sulfone, 2,4′-dihydroxydiphenylsulfone, bis (4-hydroxyphenyl) sulfide, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3 Examples include '-dichlorodiphenyl ether and 4,4'-dihydroxy-2,5-diethoxydiphenyl ether.
Examples of the ethylene oxide (EO) additions of bisphenols include those obtained by adding ethylene oxide (EO) to the aforementioned bisphenol compounds.
<Fluorene compound>

  9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-ethylphenyl) fluorene, 9,9 -Bis (4-hydroxy-3-n-propylphenyl) fluorene, 9,9-bis (4-hydroxy-3-isopropylphenyl) fluorene, 9,9-bis (4-hydroxy-3-n-butylphenyl) Fluorene, 9,9-bis (4-hydroxy-3-sec-butylphenyl) fluorene, 9,9-bis (4-hydroxy-3-tert-propylphenyl) fluorene, 9,9-bis (4-hydroxy-) 3-cyclohexylphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene, 9,9-bis 4- (2-hydroxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3 -Isopropylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-isobutylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-tert-butylphenyl) Fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-cyclohexylphenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy) -3-phenylphenyl) fluorene, 9,9- Bis (4- (2-hydroxyethoxy) -3,5-dimethylphenyl) fluorene, 9,9-bis (4- (2-hydro Shietokishi) -3-tert-butyl-6-methylphenyl) fluorene, 9,9-bis (4- (3-hydroxy-2,2-dimethyl) phenyl) fluorene, and the like.

  These may be used alone or in combination of two or more. However, since a dihydroxy compound having an aromatic ring in the structure may adversely affect optical properties, the structural unit derived from such a dihydroxy compound is the sum of the structural units derived from the dihydroxy compound in the polycarbonate resin. It is preferably used in an amount of 50 mol% or less, more preferably 20 mol% or less, and further preferably 5 mol% or less. In particular, the polycarbonate resin is a dihydroxy compound having an aromatic ring in the structure. It is preferable that the structural unit derived from is not included.

[Content ratio of structural unit derived from dihydroxy compound]
The content ratio of the structural unit derived from the dihydroxy compound represented by the formula (1) contained in the polycarbonate resin according to the present invention is preferably 20% by weight or more with respect to the total of the structural units derived from the dihydroxy compound. More preferably, it is 25% by weight or more, more preferably 30% by weight or more, and usually 95% by weight or less, preferably 90% by weight or less. When the content ratio of the structural unit is too small, the heat resistance is small and the surface hardness may be inferior. Moreover, when there is too much content rate of this structural unit, the glass transition temperature of polycarbonate resin may become high too much, and shaping | molding may become difficult, or a water absorption rate may deteriorate.

  The polycarbonate resin is represented by the dihydroxy compound represented by the formula (4), the dihydroxy compound represented by the formula (5), the dihydroxy compound represented by the formula (6), and the formula (7). In the case of containing a structural unit derived from one or more dihydroxy compounds selected from the group consisting of the dihydroxy compound represented by the formula (8) and the dihydroxy compound represented by the formula (8), 0.1 wt% or more and less than 20 wt%, preferably 0.1 wt% or more and 18 wt% or less, more preferably 0.2 wt% or more and 15 wt% or less with respect to the total of derived structural units. is there. When the structural unit derived from the dihydroxy compound represented by the above formulas (4) to (8) is contained in the polycarbonate resin in the above lower limit value or more, when the polycarbonate resin is melted and molded, foreign matters and bubbles due to heat Generation of the resin can be prevented, and coloring of the polycarbonate resin can be prevented. However, when the number of structural units is excessively large, light resistance tends to be lowered when formed into a molded product.

  All dihydroxy compounds used in the production of the polycarbonate resin according to the present invention contain a stabilizer such as a reducing agent, an antioxidant, an oxygen scavenger, a light stabilizer, an antacid, a pH stabilizer or a heat stabilizer. You may go out. In particular, since the specific dihydroxy compound according to the present invention is easily altered under acidic conditions, it is preferable to include a basic stabilizer.

Examples of the basic stabilizer include hydroxides, carbonates, phosphates, phosphites, hypophosphites of group 1 or group 2 metals in the long-period periodic table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). Acid salts, borates and fatty acid salts, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium Basic ammonium compounds such as droxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide and butyltriphenylammonium hydroxide, diethylamine, di Butylamine, triethylamine, morpholine, N-methylmorpholine, pyrrolidine, piperidine, 3-amino-1-propanol, ethylenediamine, N-methyldiethanolamine, diethylethanolamine, 4-aminopyridine, 2-aminopyridine, N, N-dimethyl- 4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine , 4-methoxypyridine, 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and other amine compounds, and di- (tert-butyl) amine and 2,2 Hindered amine compounds such as 1,6,6-tetramethylpiperidine. Among these stabilizers, tetramethylammonium hydroxide, imidazole or hindered amine compounds are preferable from the viewpoint of stabilization effect.

  The content of these basic stabilizers in all the dihydroxy compounds used in the present invention is not particularly limited, but the specific dihydroxy compounds used in the present invention are unstable in an acidic state. It is preferable to add a stabilizer so that the pH of the aqueous solution containing the specific dihydroxy compound is around 7.

  If the amount of the stabilizer is too small, the effect of preventing the alteration of the specific dihydroxy compound may not be obtained. If the amount is too large, the specific dihydroxy compound may be modified. On the other hand, it is preferably 0.0001% by weight to 1% by weight, and more preferably 0.001% by weight to 0.1% by weight.

  When these basic stabilizers are included in the dihydroxy compound used in the present invention and used as a raw material for producing a polycarbonate resin, the basic stabilizer itself becomes a polymerization catalyst, which makes it difficult to control the polymerization rate or quality, as well as the resin. The hue will be deteriorated.

  Therefore, for specific dihydroxy compounds or other dihydroxy compounds containing a basic stabilizer, the basic stabilizer should be removed by ion exchange resin or distillation before using as a raw material for the production of polycarbonate resin. Is preferred.

  In addition, since the specific dihydroxy compound used in the present invention is gradually oxidized by oxygen, in order to prevent decomposition due to oxygen during storage or handling during manufacture, water should not be mixed, and deoxygenated It is preferable to use an agent or to put it in a nitrogen atmosphere.

(Carbonated diester)
The polycarbonate resin according to the present invention can be obtained by polycondensation by a transesterification reaction using a dihydroxy compound containing the above-mentioned specific dihydroxy compound and a carbonic acid diester as raw materials. As a carbonic acid diester used, what is represented by following formula (10) is mentioned normally. These carbonic acid diesters may be used alone or in combination of two or more.

In the above formula (10), A ¹ and A ² are each a substituted or unsubstituted aliphatic hydrocarbon group having 1 to 18 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group, and A ¹ and A ² May be the same or different. A preferable example of A ¹ and A ² is a substituted or unsubstituted aromatic hydrocarbon group, and a more preferable example is an unsubstituted aromatic hydrocarbon group.

  Examples of the carbonic acid diester represented by the formula (10) include substituted diphenyl carbonates such as diphenyl carbonate (DPC) and ditolyl carbonate, dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate. Among them, preferred is diphenyl carbonate or substituted diphenyl carbonate, and particularly preferred is diphenyl carbonate.

  In addition, carbonic acid diester may contain impurities such as chloride ions, and the impurities may hinder the polymerization reaction or deteriorate the hue of the resulting polycarbonate resin. It is preferable to use a product purified by the above.

<Transesterification reaction catalyst>
The polycarbonate resin according to the present invention is produced by transesterifying the above-described dihydroxy compound and carbonic acid diester. More specifically, it can be obtained by transesterification and removing by-product monohydroxy compounds and the like out of the system.

  In the transesterification reaction, polycondensation is performed in the presence of a transesterification reaction catalyst. The transesterification reaction catalyst (hereinafter simply referred to as a catalyst or a polymerization catalyst) that can be used in the production of the polycarbonate resin of the present invention may be used. ) Can significantly affect the reaction rate or the quality of the polycarbonate resin obtained by polycondensation.

  The catalyst used is not limited as long as it can satisfy the transparency, hue, heat resistance, weather resistance, and mechanical strength of the produced polycarbonate resin. For example, a metal compound of Group 1 or Group 2 (hereinafter simply referred to as “Group 1” or “Group 2”) in the long-period periodic table, and a basic boron compound, a basic phosphorus compound, and a basic ammonium compound And basic compounds such as amine compounds. Preferably, Group 1 metal compounds and / or Group 2 metal compounds are used.

  Examples of the Group 1 metal compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate, and carbonic acid. Lithium, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, hydrogenated Cesium boron, sodium phenide boron, potassium phenide boron, lithium phenide boron, cesium phenide boron, sodium benzoate, potassium benzoate, lithium benzoate, cesium benzoate, hydrogen phosphate 2 Thorium, 2 potassium hydrogen phosphate, 2 lithium hydrogen phosphate, 2 cesium hydrogen phosphate, 2 sodium phenyl phosphate, 2 potassium phenyl phosphate, 2 lithium phenyl phosphate, 2 cesium phenyl phosphate, sodium, potassium, lithium, Examples include cesium alcoholate, phenolate, bisphenol A disodium salt, dipotassium salt, dilithium salt, and dicesium salt. Among these, lithium compounds are preferable from the viewpoint of polymerization activity and the hue of the obtained polycarbonate resin.

  Examples of the Group 2 metal compound include calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, carbonic acid. Examples include magnesium, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate. Among these, a magnesium compound, a calcium compound or a barium compound is preferable, and from the viewpoint of polymerization activity and the hue of the polycarbonate resin obtained, a magnesium compound and / or a calcium compound is more preferable, and a calcium compound is most preferable.

  In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, and an amine compound can be used in combination with the above-mentioned Group 1 metal compound and / or Group 2 metal compound. However, it is particularly preferred to use only Group 1 metal compounds and / or Group 2 metal compounds.

  Examples of the basic phosphorus compound include triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and quaternary phosphonium salts.

  Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide. Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium Dorokishido and butyl triphenyl ammonium hydroxide, and the like.

  Examples of the amine compound include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, and 4-methoxypyridine. , 2-dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline, guanidine and the like.

  The amount of the polymerization catalyst used is preferably 0.1 μmol to 300 μmol, more preferably 0.5 μmol to 100 μmol, and particularly preferably 1 μmol to 50 μmol per 1 mol of all dihydroxy compounds used in the polymerization.

  In particular, when a compound containing at least one metal selected from the group consisting of Group 2 and lithium in the long-period periodic table is used, particularly when a magnesium compound and / or a calcium compound is used, the metal amount is The amount is preferably 0.1 μmol or more, more preferably 0.3 μmol or more, particularly preferably 0.5 μmol or more per 1 mol of the dihydroxy compound. Moreover, as an upper limit, 20 micromol or less is preferable, More preferably, it is 10 micromol or less, More preferably, it is 5 micromol or less, Most preferably, it is 3 micromol or less.

  If the amount of the catalyst is too small, the polymerization rate is slowed down. Therefore, in order to obtain a polycarbonate resin having a desired molecular weight, the polymerization temperature must be increased accordingly. Therefore, there is a high possibility that the hue of the obtained polycarbonate resin is deteriorated, and the unreacted raw material volatilizes during the polymerization, and the molar ratio of the dihydroxy compound and the carbonic acid diester collapses, and the desired molecular weight may not be reached. There is sex. On the other hand, if the amount of the polymerization catalyst used is too large, undesirable side reactions may occur, which may lead to deterioration of the hue of the resulting polycarbonate resin or coloring of the resin during molding.

  However, sodium, potassium, or cesium among group 1 metals may adversely affect the hue when contained in the polycarbonate resin. And these metals may mix not only from the catalyst to be used but from a raw material or a reaction apparatus. Regardless of the source, the total amount of the compounds of these metals in the polycarbonate resin is preferably 1 ppm by weight or less, more preferably 0.5 ppm by weight or less as the amount of metal.

<Production method of polycarbonate resin>
The polycarbonate resin according to the present invention is obtained by polycondensing a dihydroxy compound containing a specific dihydroxy compound and a carbonic acid diester by an ester exchange reaction.

  The raw material dihydroxy compound and carbonic acid diester are preferably mixed uniformly before the transesterification reaction. The mixing temperature is usually 80 ° C. or higher, preferably 90 ° C. or higher, and the upper limit is usually 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 150 ° C. or lower. Among these, 100 ° C. or higher and 120 ° C. or lower is preferable. If the mixing temperature is too low, the dissolution rate may be slow or the solubility may be insufficient, often causing problems such as solidification, and if the mixing temperature is too high, the dihydroxy compound may be thermally deteriorated. May adversely affect the hue and thermal stability of the polycarbonate resin obtained.

  The operation of mixing a dihydroxy compound containing a specific dihydroxy compound as a raw material of the polycarbonate resin according to the present invention with a carbonic acid diester is an oxygen concentration of 10 vol% or less, more preferably 0.0001 vol% to 10 vol%, and more preferably 0.0001 vol% to 5 vol%. In particular, it is preferable to perform in an atmosphere of 0.0001 vol% to 1 vol% from the viewpoint of preventing hue deterioration.

  In order to obtain the polycarbonate resin according to the present invention, the carbonic acid diester is preferably used in a molar ratio of 0.94 to 1.04, more preferably, with respect to all dihydroxy compounds including the specific dihydroxy compound used in the reaction. The molar ratio is 0.98 to 1.03, more preferably 1.00 to 1.02. When this molar ratio becomes small, the terminal phenyl group of the produced polycarbonate resin is reduced, and appearance defects during molding are likely to occur.

  Moreover, when this molar ratio becomes large, the rate of transesterification may decrease, or it may be difficult to produce a polycarbonate resin having a desired molecular weight. The decrease in the transesterification reaction rate may increase the heat history during the polymerization reaction, and may deteriorate the hue and weather resistance of the resulting polycarbonate resin. Furthermore, when the molar ratio of the carbonic acid diester is increased with respect to all the dihydroxy compounds including the specific dihydroxy compound, the amount of the residual carbonic acid diester in the obtained polycarbonate resin and the compound represented by the formula (3) are increased. May cause problems such as dirt, odor and poor appearance.

  In the present invention, the method of polycondensing a dihydroxy compound and a carbonic acid diester is usually carried out in multiple stages using a plurality of reactors in the presence of the above-mentioned catalyst. The type of reaction may be any of a batch method, a continuous method, or a combination of a batch method and a continuous method, but a continuous method is preferred, in which a polycarbonate resin can be obtained with less heat history and excellent productivity.

  In the initial stage of polymerization, it is preferable to obtain a prepolymer at a relatively low temperature and low vacuum, and in the latter stage of polymerization, it is preferable to increase the molecular weight to a predetermined value at a relatively high temperature and high vacuum, but the jacket temperature at each molecular weight stage. Appropriate selection of the internal temperature and pressure in the reaction system is important from the viewpoint of controlling the polymerization rate and the quality of the polycarbonate resin obtained. For example, if either the temperature or the pressure is changed too quickly before the polymerization reaction reaches a predetermined value, the unreacted monomer will be distilled, causing the molar ratio of the dihydroxy compound and the carbonic acid diester to change, resulting in a decrease in the polymerization rate. Or a polymer having a predetermined molecular weight or terminal group may not be obtained, and as a result, the object of the present invention may not be achieved.

Furthermore, it is effective to use a reflux condenser for the polymerization reactor in order to suppress the amount of the monomer to be distilled off, and the effect is particularly great in a reactor at the initial stage of polymerization where there are many unreacted monomer components. The temperature of the refrigerant introduced into the reflux condenser can be appropriately selected according to the monomer used, but the temperature of the refrigerant introduced into the reflux condenser is usually 45 to 180 ° C. at the inlet of the reflux condenser. Yes, preferably 80 to 150 ° C, particularly preferably 100 to 130 ° C. If the temperature of the refrigerant is too high, the amount of reflux decreases and the effect is reduced. On the other hand, if the temperature is too low, the distillation efficiency of the monohydroxy compound that should be distilled off tends to decrease. As the refrigerant, hot water, steam, heat medium oil or the like is used, and steam or heat medium oil is preferable.

  In order to maintain the polymerization rate appropriately and suppress the distillation of the monomer while not impairing the hue of the final polycarbonate resin, it is important to select the kind and amount of the catalyst described above. The polycarbonate resin according to the present invention is preferably produced by polymerizing in a plurality of stages using a plurality of reactors using a catalyst, but the reason for carrying out the polymerization in a plurality of reactors is the initial stage of the polymerization reaction. In order to shift the equilibrium to the polymerization side in the latter stage of the polymerization reaction, it is important to suppress the volatilization of the monomer while maintaining the necessary polymerization rate because there are many monomers contained in the reaction solution. This is because it is important to sufficiently distill off the by-produced monohydroxy compound. Thus, in order to set different polymerization reaction conditions, it is preferable from the viewpoint of production efficiency to use a plurality of polymerization reactors arranged in series.

  As described above, the number of reactors used in the production of the polycarbonate resin according to the present invention may be at least two. However, from the viewpoint of production efficiency and the like, three or more, preferably 3 to 5, particularly Preferably four. In the present invention, if there are two or more reactors, a plurality of reaction stages having different conditions may be provided in the reactor, or the temperature and pressure may be continuously changed.

  In the production of the polycarbonate resin according to the present invention, the polymerization catalyst can be added to the raw material preparation tank, the raw material storage tank, or can be added directly to the polymerization tank, but from the viewpoint of supply stability and polymerization control. Is provided with a catalyst supply line in the middle of the raw material line before being supplied to the polymerization tank, and is preferably supplied as an aqueous solution.

If the temperature of the polymerization reaction is too low, the productivity is lowered and the thermal history of the product is increased. If it is too high, not only the monomer is volatilized but also decomposition and coloring of the polycarbonate resin may be promoted. Specifically, in the first stage reaction, the internal temperature of the polymerization reactor is 130 to 210 ° C, preferably 150 to 205 ° C, and more preferably 170 to 200 ° C.
The reaction system pressure is 1-110 kPa, preferably 5-70 kPa, more preferably 7-30 kPa (absolute pressure), and the reaction time is 0.1-10 hours, preferably 0.5-3. It is carried out while distilling off the monohydroxy compound generated over time.

  In the second and subsequent stages, the pressure in the reaction system is gradually reduced from the pressure in the first stage, and subsequently generated monohydroxy compounds are removed from the reaction system. In particular, in order to remove the compound represented by the formula (3), the pressure in the second and subsequent stages is set to 15 KPa or less, and finally the reaction system pressure (absolute pressure) is set to 600 Pa or less, and the maximum internal temperature 190 to It is carried out at 240 ° C., preferably 1950 to 235 ° C., usually for 0.1 to 5 hours, preferably 1 to 4 hours, particularly preferably 0.5 to 3 hours.

In order to obtain a polycarbonate resin having a predetermined molecular weight, if the polymerization temperature is high and the polymerization time is too long, the color tone tends to deteriorate. In particular, in order to obtain a polycarbonate resin that suppresses coloring and thermal deterioration of the polycarbonate resin and has a good hue and a low content of the compound represented by the formula (3), the minimum internal temperature in all reaction stages is 210 ° C. or higher. The maximum temperature is preferably 240 ° C. or lower, and particularly preferably 210 ° C. or higher and 235 ° C. or lower.
In addition, the reaction time when the minimum temperature of the internal temperature in the entire reaction stage is 210 ° C. or more and the maximum temperature is 240 ° C. or less is less than 3 hours, so that coloring and thermal deterioration of the polycarbonate resin can be suppressed and the hue is good. A polycarbonate resin is obtained, and the amount of the compound represented by the formula (3) can be further suppressed, and is preferably within 2.5 hours.
In addition, in order to suppress a decrease in the polymerization rate in the latter half of the polymerization reaction and to minimize deterioration due to thermal history, it is excellent in plug flow property and interface renewability at the final stage of polymerization and is represented by the formula (3). It is preferable to use a horizontal reactor excellent in removing compounds.

  The monohydroxy compound produced as a by-product is preferably reused as a raw material for diphenyl carbonate, bisphenol A, etc. after purification as necessary from the viewpoint of effective utilization of resources.

  The polycarbonate resin according to the present invention is usually cooled and solidified after polycondensation as described above, and pelletized with a rotary cutter or the like. The method of pelletization is not limited, but it is extracted from the final polymerization reactor in a molten state, cooled and solidified in the form of a strand and pelletized, or uniaxial or biaxial extrusion in the molten state from the final polymerization reactor. The resin is supplied to the machine, melt-extruded, cooled and solidified into pellets, or extracted from the final polymerization reactor in a molten state, cooled and solidified in the form of strands, once pelletized, and then uniaxially again Or after supplying resin to a twin-screw extruder, melt-extruding, cooling and solidifying and pelletizing, etc. are mentioned.

  When an extruder is used, in the extruder, the residual monomer is devolatilized under reduced pressure, and generally known thermal stabilizers, neutralizers, UV absorbers, light stabilizers, mold release agents, colorants, antistatic agents Further, a lubricant, a lubricant, a plasticizer, a compatibilizer, a flame retardant and the like can be added and kneaded.

  The melt kneading temperature in the extruder depends on the glass transition temperature and molecular weight of the polycarbonate resin, but is usually 200 to 300 ° C, preferably 210 to 280 ° C, and more preferably 220 to 270 ° C. When the melt kneading temperature is lower than 200 ° C., the melt viscosity of the polycarbonate resin is high, the load on the extruder is increased, and the productivity is lowered. When the temperature is higher than 300 ° C., the polycarbonate resin is severely thermally deteriorated, resulting in a decrease in mechanical strength due to a decrease in molecular weight, coloring, generation of gas, and generation of a compound represented by the formula (3).

  The molecular weight of the polycarbonate resin according to the present invention thus obtained can be represented by a reduced viscosity, and the reduced viscosity is usually 0.30 dL / g or more, preferably 0.35 dL / g or more, and the reduced viscosity. Is preferably 1.20 dL / g or less and 1.00 dL / g or less, more preferably 0.80 dL / g or less. If the reduced viscosity of the polycarbonate resin is too low, the mechanical strength of the molded product may be small. If it is too large, the fluidity at the time of molding tends to decrease, and the productivity and moldability tend to decrease. The reduced viscosity of the polycarbonate resin was measured using a Ubbelohde viscosity tube at a temperature of 20.0 ° C. ± 0.1 ° C., using methylene chloride as a solvent and adjusting the polycarbonate resin concentration to 0.6 g / dL precisely. The Details of the method for measuring the reduced viscosity are described in the Examples section.

[Polycarbonate resin additive]
<Phosphorus compounds>
The polycarbonate resin according to the present invention preferably contains a phosphorus compound added to deactivate the polymerization catalyst and further suppress coloring of the polycarbonate resin at a high temperature. The phosphorus compound is at least one selected from the group consisting of phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, phosphonic acid, phosphonic acid ester, acidic phosphoric acid ester, and aliphatic cyclic phosphite ester. It is preferable to use seeds. Among them, phosphorous acid, phosphonic acid, and phosphonic acid ester are more excellent in catalyst deactivation and coloring suppression effects, and phosphonic acid ester is particularly preferable.

Examples of phosphonic acid include phosphonic acid (phosphorous acid), methylphosphonic acid, ethylphosphonic acid, vinylphosphonic acid, decylphosphonic acid, phenylphosphonic acid, benzylphosphonic acid, aminomethylphosphonic acid, methylenediphosphonic acid, 1-hydroxyethane- Examples include 1,1-diphosphonic acid, 4-methoxyphenylphosphonic acid, nitrilotris (methylenephosphonic acid), and propylphosphonic anhydride.

  Examples of phosphonates include dimethyl phosphonate, diethyl phosphonate, bis (2-ethylhexyl) phosphonate, dilauryl phosphonate, dioleyl phosphonate, diphenyl phosphonate, dibenzyl phosphonate, dimethyl methylphosphonate, diphenyl methylphosphonate, and ethylphosphonic acid. Diethyl, diethyl benzylphosphonate, dimethyl phenylphosphonate, diethyl phenylphosphonate, dipropyl phenylphosphonate, diethyl (methoxymethyl) phosphonate, diethyl vinylphosphonate, diethyl hydroxymethylphosphonate, dimethyl (2-hydroxyethyl) phosphonate, p-methylbenzylphosphonate diethyl, diethylphosphonoacetic acid, diethylphosphonoacetic acid ethyl, diethylphosphonoacetic acid tert-butyl, (Robenzyl) diethyl phosphonate, diethyl cyanophosphonate, diethyl cyanomethylphosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, diethylphosphonoacetaldehyde diethyl acetal, diethyl (methylthiomethyl) phosphonate Can be mentioned.

  Acid phosphate esters include dimethyl phosphate, diethyl phosphate, divinyl phosphate, dipropyl phosphate, dibutyl phosphate, bis (butoxyethyl) phosphate, bis (2-ethylhexyl) phosphate, diisotridecyl phosphate, phosphate Examples include phosphoric acid diesters such as dioleyl, distearyl phosphate, diphenyl phosphate and dibenzyl phosphate, mixtures of diesters and monoesters, diethyl chlorophosphate, and zinc stearyl phosphate.

  An aliphatic cyclic phosphite is defined as a phosphite compound that does not contain an aromatic group in a cyclic structure containing a phosphorus atom. For example, bis (decyl) pentaerythritol diphosphite, bis (tridecyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis (2,6-tert-butylphenyl) pentaerythritol diphosphite, bis (nonyl) Phenyl) pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, Examples thereof include a polymer type compound composed of a dihydroxy compound such as hydrogenated bisphenol A / pentaerythritol phosphite polymer and pentaerythritol diphosphite.

  These may be used alone or in a combination of two or more in any combination and ratio.

  If the content of the phosphorus compound is too small, the effect of catalyst deactivation and coloring suppression is insufficient, and if it is too much, the polycarbonate resin may be colored, or coloring under wet heat conditions may occur. The content of the phosphorus compound is not particularly limited, but the content of phosphorus atom in the polycarbonate resin is preferably 0.02 ppm by weight or more and 0.7 ppm by weight or less, more preferably 0.05 ppm by weight. As mentioned above, 0.65 weight ppm or less is preferable, and 0.07 weight ppm or more and 0.60 weight ppm or less are particularly preferable.

  Since the phosphorus compound is usually phosphorus trichloride as a starting material, unreacted substances and chlorine-containing components derived from detached hydrochloric acid may remain, but the chlorine atom contained in the phosphorus compound may remain. The amount is preferably 5% by weight or less. When the residual amount of chlorine atoms is large, there is a concern that the metal part of the production facility to which the phosphorus compound is added is corroded, the thermal stability of the polycarbonate resin is lowered, and the molecular weight reduction due to coloring or thermal deterioration is promoted.

As described above, the phosphorus compound is preferably added and kneaded to the polycarbonate resin using an extruder. In particular, it is most effective to supply the polycarbonate resin to the extruder in a molten state after polymerization and immediately add the phosphorus compound to the resin. Further, when the catalyst is deactivated and devolatilization is performed by a vacuum vent with an extruder, low molecular components can be efficiently devolatilized.

<Hindered phenol compounds>
The polycarbonate resin according to the present invention can be expected to further improve the color tone of the polycarbonate resin by containing a hindered phenol compound in addition to the phosphorus compound.

Specific examples of hindered phenol compounds include 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4-methoxyphenol, and 2-tert-butyl- 4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,5-di-tert-butylhydroquinone, n- Octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate, 2-t
ert-butyl-6- (3′-tert-butyl-5′-methyl-2′-hydroxybenzyl) -4-methylphenyl acrylate, 2,2′-methylene-bis- (4-methyl-6-tert- Butylphenol), 2,2'-methylene-bis- (6-cyclohexyl-4-methylphenol), 2,2'-ethylidene-bis- (2,4-di-tert-butylphenol), tetrakis- [methylene-3 -(3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate] -methane, n-octadecyl-3- (3', 5'-di-tert-butyl-4'-hydroxyphenyl) Propionate 1,3
, 5-trimethyl-2,4,6-tris- (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, triethylene glycol-bis [3- (3-tert-butyl-5-methyl- 4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], pentaerythritol-tetrakis [3- (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate] and the like.
These may be used alone or in a combination of two or more in any combination and ratio.

The content of the hindered phenol compound in the polycarbonate resin according to the present invention is preferably 0.001 to 1 part by weight, and 0.005 to 0.5 part by weight, when the polycarbonate resin is 100 parts by weight. Part is more preferable, and 0.01 part by weight to 0.3 part by weight is even more preferable.
In addition, it is preferable that a hindered phenol compound and the following antioxidants are added and kneaded to the polycarbonate resin using an extruder, similarly to the phosphorus compound.

<Antioxidant>
For the purpose of antioxidation, a generally known antioxidant can be added to the polycarbonate resin according to the present invention.

Specific examples of the antioxidant include triphenyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, Trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, 2,2-methylenebis (4 6-di-tert-butylphenyl) octyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tributyl phosphate, triethyl phosphate, trimethyl phosphate, trimethyl phosphate Phenyl phosphate, diphenyl monoorthoxenyl phosphate, dibutyl phosphate, dioctyl phosphate, diisopropyl phosphate, 4,4′-biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl), pentaerythritol tetrakis (3-mercaptopropio Nate), pentaerythritol tetrakis (3-lauryl thiopropionate), glycerol-3-stearyl thiopropionate, N, N-hexamethylene bis (3,5-di-tert-butyl-4-hydroxy-hydrocinna Mido), tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 4,4′-biphenylenediphosphinic acid tetrakis (2,4-di-tert-butylphenyl), 3,9-bis {1,1-dimethyl-2- [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl} -2,4,8,10-tetraoxaspiro (5,5) Undecane and the like can be mentioned.

These antioxidants may be used alone or in combination of two or more.
The blending amount of these antioxidants is preferably 0.0001 parts by weight to 0.1 parts by weight, more preferably 0.0005 parts by weight to 0.08 parts by weight, when the polycarbonate resin is 100 parts by weight. More preferred is 0.001 to 0.05 parts by weight.

[Bluing agent]
The polycarbonate resin according to the present invention may contain a bluing agent.

  The bluing agent may be appropriately selected from bluing agents usually used in polycarbonate resin compositions, and the blending amount may be adjusted and used, or a plurality of types of bluing agents may be used.

The content of the bluing agent in the polycarbonate resin according to the present invention is preferably 0.1 × 10 ^{−4 to} 10.0 × 10 ⁻⁴ parts by weight, more preferably 100 parts by weight, more preferably 0.3 × 10 ^{−4 to} 5.0 × 10 ⁻⁴ parts by weight, particularly preferably 0.3 × 10 ^{−4 to} 2.0 × 10 ⁻⁴ parts by weight.

If the content of the bluing agent is 0.1 × 10 ⁻⁴ parts by weight or more, the YI value before and after the accelerated light resistance test of the polycarbonate resin plate of the present invention is set to a specific range, or the b * value is 3 Since it becomes easy to make it below, it is preferable. On the other hand, if the content of the bluing agent is 10.0 × 10 ⁻⁴ parts by weight or less, the brightness does not decrease, and therefore, it is preferable to make the L * value 90 or more.

  As the bluing agent, those used in the polycarbonate resin composition can be suitably used. From the viewpoint of the absorption wavelength, a dye having a maximum absorption wavelength of preferably 520 to 600 nm, more preferably 540 to 580 nm. Is used.

An anthraquinone-based bluing agent is preferable as the bluing agent. Specific examples thereof include, for example, the general name Solvent Violet 13 [CA. No. (Color Index No) 60725; Trademarks “Malexex Violet B” manufactured by LANXESS, “Diaresin Blue G” manufactured by Mitsubishi Chemical Corporation, “Sumiplast Violet B” manufactured by Sumitomo Chemical Co., Ltd.], Solvent Violet 14 , Generic name Solvent Violet 31 [CA. No. 68210; Trade names “Diaresin Violet D” manufactured by Mitsubishi Chemical Corporation], Solvent Violet 33 [CA. No. 60725; trade name “Diaresin Blue J” manufactured by Mitsubishi Chemical Corporation], Solvent Violet 36 [CA. No. 68210; brand name "Macrolex Violet 3R" manufactured by LANXESS, Solven
t Blue45 [CA. No. 61110; trade name “Tetrazole Blue RLS” manufactured by Sand Corp.], generic name Solvent Blue 94 [CA. No. 61500; Trade name “Diaresin Blue N” manufactured by Mitsubishi Chemical Co., Ltd., generic name Solvent Blue 97 [manufactured by LANXESS “Macrolex Blue RR”], generic name Solvent Blue 45, generic name Solvent Blue 87, and generic name Disperse Violet 28 It is done.

  Among these, the general name Solvent Violet 13 (“Macrolex Violet B” manufactured by LANXESS), the general name Solvent Violet 36 [“Macrolex Violet 3R” manufactured by LANXESS ”, and the general name Solvent Blue97 [“ Macrolex Blue RR ”manufactured by LANXESS) The general name Solvent Violet 13 [“Macrolex Violet B” manufactured by LANXESS, Inc.] is more preferable. In particular, a dye having a structure represented by the following formula (7), that is, the general name Solvent Violet 13 [CA. No. (Color Index No.) 60725; trade names “Malexex Violet B” manufactured by LANXESS, “Diaresin Blue G” manufactured by Mitsubishi Chemical Corporation, and “Sumiplast Violet B” manufactured by Sumitomo Chemical Co., Ltd.] are preferable.

  As the bluing agent, a pigment having a maximum absorption wavelength of preferably 520 to 600 nm, more preferably 540 to 580 nm can be used, and the above dye and pigment can also be used in combination.

  One type of bluing agent may be used alone, or two or more types may be used in combination, but the amount of bluing agent used is preferably small and the type of bluing agent used is preferably small. .

  The blending time and blending method of the above bluing agent to be blended with the polycarbonate resin are not particularly limited. As the blending time, for example, a method of adding together with the raw material before the polymerization reaction and performing the polymerization as it is, a method of blending with a pipe or an extruder at the end of the polymerization reaction, a method of blending when the polycarbonate resin and other compounding agents are melt-kneaded However, it is preferable to mix by kneading after the completion of the polymerization reaction because the dispersion of the bluing agent is improved and the b * value and the L * value are easily adjusted. In particular, a method of introducing into a extruder in a molten state after completion of the polycondensation reaction, blending a bluing agent and melt-kneading is preferable because the influence of heat history and oxygen mixing can be minimized.

[Polycarbonate resin composition]
Polycarbonate resins according to the present invention include, for example, aromatic polycarbonate resins, aromatic polyesters, aliphatic polyesters, polyamides, polystyrenes, polyolefins, acrylics, amorphous polyolefins, ABS, AS, and other synthetic resins, polylactic acid, and polybutylene succinate. It can also be used as a polymer alloy by kneading with one or more of biodegradable resins such as rubber and rubber.

  Further, the polycarbonate resin according to the present invention includes a nucleating agent, a flame retardant, a flame retardant aid, an inorganic filler, an impact modifier, a hydrolysis inhibitor, and a foaming agent that are usually used in a resin composition together with these other resin components. A polycarbonate resin composition can be prepared by adding a dye or pigment.

[Transparent film of polycarbonate resin]
<Thickness of film>
The thickness of the transparent film of the present invention is preferably 40 μm or less, more preferably 38 μm or less, and further preferably 36 μm or less. Moreover, 5 micrometers or more are preferable, 10 micrometers or more are more preferable, and 15 micrometers or more are further more preferable. When it is thicker than 40 μm, the retardation of the film becomes large. On the other hand, if it is thinner than 5 μm, it may cause tearing or wrinkling during handling. Moreover, it is preferable that the thickness of a film is uniform in an effective part. The difference between the maximum thickness and the minimum thickness of the effective portion is preferably 7 μm or less, more preferably 5 μm or less, and further preferably 4 μm or less.
<Phase difference>
In the transparent film of the present invention, both the in-plane retardation R (589) and thickness retardation Rth (589) measured at a wavelength of 589 nm are preferably 10 nm or less, more preferably 8 nm or less, and 5 nm or less. More preferably it is. When it is larger than 10 nm, the viewing angle characteristics are adversely affected when used as a polarizing plate protective film.
Further, the difference between Rth (589) and R (589), that is, Rth (589) −R (589), as it becomes closer to 0, does not adversely affect the viewing angle characteristics, and is preferably −8 nm to 8 nm. Is from −5 nm to 5 nm, more preferably from −3 nm to 3 nm, particularly preferably from −1.2 nm to 1.2 nm.

[Production method of polycarbonate resin film]
The transparent film of the present invention is obtained by extruding the above polycarbonate resin or resin composition. The method of extrusion molding is not particularly limited, but in order to produce a film with small optical distortion and excellent flame resistance, light resistance, etc., it is preferable to select the T-die extrusion method among various extrusion methods. It is.

  As a specific production method, the above-described polycarbonate resin or resin composition and additives further added as necessary, master batch pellets, other types of resin pellets, and the like are supplied to an extruder through a feeder, Examples of the method include melt-kneading and extruding while forming into a film or a sheet with a T-die. At this time, the set temperature of the extruder or T die is preferably 210 ° C. or higher and 270 ° C. or lower, and more preferably 210 ° C. or higher and 250 ° C. or lower.

<Surface roughness of cooling roll>
The surface roughness of the cooling roll used for the extrusion molding of the transparent film of the present invention may be designed based on the roughness required for the product. However, when a high mirror appearance is required, it conforms to, for example, JIS B0601 (2001). It is preferable to use a metallic mirror roll having a maximum surface height Rz of 0.3 μm or less.

The transparent film of the present invention needs to be excellent in thickness uniformity as described later. As one of means for improving the thickness accuracy, the polycarbonate of the present invention is provided by providing a gear pump between the extruder and the T die so that the outlet side resin pressure fluctuation is 1 to 10% per 30 minutes. It is preferable to manufacture a resin plate. Usually, in a single-screw or twin-screw extruder, extrusion pulsation due to screw rotation occurs, and accordingly, film or plate thickness fluctuations occur in synchronization with this. For this reason, it is preferable to cancel extrusion pulsation by providing a two-gear pump or a three-gear pump.
In addition, since the change in pressure at the outlet side of the gear pump is 1 to 10% per 30 minutes, the thickness in the film flow direction does not change abruptly, and the thickness can be easily controlled by fine adjustment during the extrusion operation. There are also advantages.
<Extruder>
The melt kneading temperature in the extruder depends on the glass transition temperature and molecular weight of the polycarbonate resin, but is usually 200 to 300 ° C, preferably 210 to 280 ° C, and more preferably 220 to 270 ° C. When the melt kneading temperature is lower than 200 ° C., the melt viscosity of the polycarbonate resin is high, the load on the extruder is increased, and the productivity is lowered. When the temperature is higher than 300 ° C., the polycarbonate resin is severely thermally deteriorated, resulting in a decrease in mechanical strength due to a decrease in molecular weight, coloring, and gas generation, which may cause bubbles in sheets and films. In addition, in the polycarbonate resin obtained by polycondensation as described above, there are usually raw material monomers and esters that may cause deterioration of the hue or thermal stability of the resin, and further the occurrence of bleed out of the film. Low molecular weight compounds such as monohydroxy compounds or polycarbonate resin oligomers produced as a by-product in the exchange reaction remain, but use an extruder having a vent port, and preferably reduce the pressure from the vent port using a vacuum pump or the like. These can be removed by devolatilization. Also, devolatilization can be promoted by introducing a volatile liquid such as water into the extruder. The number of vent ports may be one or plural, but preferably two or more.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by a following example, unless the summary is exceeded.

[Evaluation method]
Below, evaluation of the polycarbonate resin and the film obtained from this resin was performed by the following method.

(1) Measurement of reduced viscosity A polycarbonate resin sample was dissolved in methylene chloride to prepare a polycarbonate resin solution having a concentration of 0.6 g / dL. Measured at a temperature of 20.0 ° C. ± 0.1 ° C. using an Ubbelohde viscometer manufactured by Moriyu Rika Kogyo Co., Ltd. From the solvent passage time t ₀ and the solution passage time t, the relative viscosity η _The relative viscosity η _sp was determined from the relative viscosity η _rel by the following formula (ii).
η _rel = t / t ₀ (i)
η _sp = (η−η ₀ ) / η ₀ = η _rel −1 (ii)
The reduced viscosity η _sp / c was determined by dividing the specific viscosity η _sp by the concentration c (g / dL). The higher this value, the higher the molecular weight.

(2) Quantification of terminal phenyl group, terminal hydroxy group and isosorbide terminal double bond About 30 mg of polycarbonate resin pellets are weighed and dissolved in about 0.7 mL of deuterated chloroform to obtain a solution, 1,1,2,2-tetrabromo. A known amount of ethane was added as an internal standard substance, and this was put in an NMR tube having an inner diameter of 5 mm, and a ¹ H NMR spectrum was measured at room temperature using JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL Ltd. The amount of the terminal phenyl group, the terminal hydroxy group, and the terminal double bond was quantified based on the signal intensity ratio based on the standard substance and the terminal phenyl group, terminal hydroxy group, and terminal double bond of the polycarbonate resin.
The equipment and conditions used are as follows.
Phenyl group terminal ratio (%) = [terminal group formula (α) existence number / total terminal existence number] × 100
Device: JNM-AL400 (resonance frequency 400 MHz) manufactured by JEOL Ltd.
・ Measurement temperature: normal temperature ・ Relaxation time: 6 seconds ・ Number of integrations: 512 times

(3) Measurement of content of monohydroxy compound and compound represented by the following formula (3) About 1 g of a polycarbonate resin sample is precisely weighed and dissolved in 5 mL of methylene chloride to obtain a solution, so that the total amount becomes 25 mL. Acetone was added to the solution for reprecipitation. Subsequently, the treatment liquid was filtered through a 0.2 μm disk filter and quantified by liquid chromatography.

(4) Melt viscosity A polycarbonate resin sample dried at 100 ° C. for 6 hours is heated to 240 ° C. using a capillary rheometer (manufactured by Toyo Seiki Co., Ltd.) equipped with a die having a capillary with a diameter of 1 mm and a length of 10 mm. was measured between shear rate γ = 9.12~1824 ^{(sec -1),} the melt viscosity (unit: Pa · s) at 91.2Sec ^-1 was read.

(5) Glass transition temperature (Tg) of polycarbonate resin
The glass transition temperature of the polycarbonate resin was measured using a differential scanning calorimeter (DSC 6220 manufactured by SII Nanotechnology). About 10 mg of a polycarbonate resin sample was put in an aluminum pan manufactured by the same company and sealed, and the temperature was raised from room temperature to 250 ° C. at a temperature rising rate of 20 ° C./min under a nitrogen stream of 50 mL / min. After maintaining the temperature for 3 minutes, it was cooled to 0 ° C. at a rate of 20 ° C./min. The temperature was maintained at 0 ° C. for 3 minutes, and the temperature was increased again to 200 ° C. at a rate of 20 ° C./min. From the DSC data obtained at the second temperature increase, the extrapolated glass transition start temperature was adopted.
(6) Flexural modulus Based on ISO178, the flexural modulus (unit: MPa) of the polycarbonate resin was measured at 23 ° C. using an ISO test piece having a thickness of 4.0 mm.

(7) Film forming conditions Polycarbonate resin composition with a twin screw extruder with a vent (Tex30α manufactured by Nippon Steel, Ltd., cylinder set temperature: 240 ° C.), T die (width 250 mm, set temperature: 220 ° C.), Using a film forming apparatus equipped with a chill roll (set temperature: 100 to 120 ° C.) and a winder, a film was produced about 500 m continuously for 2 hours. When winding a film around a paper core, a cutter blade was brought into contact with 20 mm portions on both ends of the film, slitting was performed, and a film was obtained with a film width of 160 mm.
(8) Film thickness Using a contact thickness meter (product name “Digital Linear Gauge DG-933” manufactured by Ono Sokki Co., Ltd.) at intervals of 20 mm in the TD direction every 100 m in the MD direction from the leading edge of the film obtained. The thickness was measured. Here, the maximum thickness among all the thicknesses of the obtained films was defined as “maximum thickness”, and the minimum thickness was defined as “minimum thickness”.
A smaller value of “difference between maximum thickness and minimum thickness” indicates that the film has a uniform thickness and the thickness accuracy is high. In this example, it was determined that the difference between the “difference between the maximum thickness and the minimum thickness” was 7 μm or less.
(9) Presence / absence of periodic defects Visually confirm the acquired film, and cycle the defects occurring at a constant period at the same position in the TD direction at an integral multiple of the circumferential length of the chill roll in the MD direction of the film. It was a fault.
When no periodic defect was confirmed, the evaluation was “None”, and when even one periodic defect was confirmed, the evaluation was “Yes”. The term “defect” as used herein refers to an appearance defect such as a dent or stain on the film surface caused by transfer of foreign matter attached to the roll surface onto the film. When the periodic defect is “present”, not only a film having an excellent appearance cannot be obtained, but also the productivity of the film is deteriorated.
(10) Occurrence of breakage at the time of slitting When the film was slitted, if the portion to be acquired (genuine part) was torn, “x”, otherwise it was marked “○” . When the evaluation is “x”, the productivity of the film is deteriorated, which is not preferable.
(11) Occurrence of winding tightening When a film of about 500m wound on a paper core is stored for 2 weeks in an environment maintained at room temperature 23 ° C and humidity 50%, the generation of wrinkles due to winding tightening can be visually confirmed. Was marked “x”, and when no wrinkle was confirmed, it was marked “no”. When the evaluation is “x”, a wrinkled film is not suitable for use because it cannot maintain desired physical properties during film production. Moreover, since there exists a possibility that the change of the film physical property accompanying the shape change of a film may be induced at the time of use in a high-humidity environment, it is not preferable.
(12) Occurrence of curl under dry heat A sample cut to 100 mm in width and 100 mm in length from the obtained film is placed in a dryer at 70 ° C. for 10 hours, and then the occurrence of curl is visually confirmed in the sample. When it was able to be confirmed, it was set as "x", and when it could not be confirmed, it was set as "None". When the evaluation is “x”, the curled film cannot be used because it cannot maintain desired physical properties during film production. Moreover, since there exists a possibility of inducing the change of the film physical property accompanying the shape change of a film at the time of use in a high temperature environment, it is unpreferable.
(13) In-plane retardation (R) and thickness retardation (Rth) of the film
With respect to a sample obtained by cutting the film into a width of 4 cm and a length of 4 cm, an in-plane retardation (R (589)) and thickness retardation at 589 nm using a retardation measuring device (product name “KOBRA WRXY2020” manufactured by Oji Scientific Instruments) (Rth (589)) was measured When used as a polarizer protective film, in order to significantly reduce the visibility of the image display device when a retardation is developed, in this example, the in-plane retardation R measured at a wavelength of 589 nm was measured. It was determined that both (589) and thickness retardation Rth (589) were preferably 10 nm or less.
Further, the difference between Rth (589) and R (589), that is, Rth (589) −R (589) is preferably as it is closer to 0 because it does not adversely affect the viewing angle characteristics. In this embodiment, −8 nm to 8 nm It was judged that the following was preferable.

(14) Judgment of film In this example, in each evaluation system (Rth (589), R (589), Rth (589) -R (589), difference between maximum thickness and minimum thickness, presence of periodic defect, slit The case where there was no inferior (unfavorable) part due to the occurrence of breakage at the time, the occurrence of winding tightening, and the occurrence of curling due to dry heat) was accepted, and the one with one or more unfavorable parts was rejected.

[Raw materials]
The abbreviations and manufacturers of the compounds used in the following Examples and Comparative Examples are as follows.

<Dihydroxy compound>
・ ISB: Isosorbide (Rocket Fleure)
CHDM: 1,4-cyclohexanedimethanol [manufactured by SK Chemical Co.]
TCDDM: Tricyclodecane dimethanol [manufactured by OXEA]
<Carbonated diester>
・ DPC: Diphenyl carbonate [Mitsubishi Chemical Corporation]
<Hindered phenol compounds>
Irganox 1010: pentaerythritol-tetrakis [3- (3,5-di-
tert-butyl-4-hydroxyphenyl) propionate] [manufactured by BASF]

<Phosphorus compounds>
・ Phosphorous acid [manufactured by Taihei Chemical Industry Co., Ltd.] (molecular weight 82.0)
AS2112: Tris (2,4-di-tert-butylphenyl) phosphite [manufactured by ADEKA Corporation] (molecular weight 646.9)
ADK STAB PEP-36: Bis (2,6-t-butyl-4-methylphenyl) pentaerythrityl diphosphite) (manufactured by Adeka Corporation)
Those having a chlorine atom content of 5% by weight or less were used.

[Example 1]
Polycarbonate resin was polymerized using a continuous polymerization facility comprising three vertical stirring reactors, one horizontal stirring reactor, and a twin screw extruder. ISB, CHDM, and DPC were respectively melted in tanks and continuously fed to the first vertical stirring reactor at a molar ratio ISB / TCDDM / DPC = 0.700 / 0.300 / 1.015. At the same time, an aqueous solution of calcium acetate monohydrate as a catalyst was supplied to the first vertical stirring reactor so as to be 1.5 μmol with respect to 1 mol of all dihydroxy compounds. The liquid level was kept constant while controlling the opening degree of the valve provided in the transfer pipe at the bottom of the reactor so that the average residence time in the first vertical stirring reactor was 90 minutes. The reaction liquid discharged from the bottom of the reactor is successively successively supplied to the second vertical stirring reactor, the third vertical stirring reactor, and the fourth horizontal stirring reactor [2-axis glasses blade manufactured by Hitachi Plant Technologies, Ltd.]. Continuously supplied. The first vertical stirring reactor and the second vertical stirring reactor were equipped with a reflux condenser, and the distillation of unreacted dihydroxy compound and DPC was suppressed by adjusting the reflux ratio.
The reaction temperature, internal pressure and residence time of each reactor are as follows: first vertical stirring reactor: 190 ° C., 25 kPa, 90 minutes, second vertical stirring reactor: 195 ° C., 10 kPa, 45 minutes, third vertical type Stirring reactor: 210 ° C., 3 kPa, 45 minutes, fourth horizontal stirring reactor: 230 ° C., 0.5 kPa, 90 minutes. The operation was performed while finely adjusting the degree of vacuum of the fourth horizontal stirring reactor so that the reduced viscosity of the obtained polycarbonate resin was 0.34 dL / g to 0.36 dL / g. A gear pump is attached to the outlet of the fourth horizontal stirring reactor, and when the rotation speed of the gear pump is constant, the discharge pressure is made constant by finely adjusting the degree of pressure reduction of the fourth horizontal stirring reactor. I can do it. Since the discharge pressure is correlated with the reduced viscosity, the obtained resin has a uniform reduced viscosity.
The polycarbonate resin was continuously extracted from the fourth horizontal stirring reactor, and then the resin was supplied in a molten state to a twin-screw extruder [TEX30α manufactured by Nippon Steel Works, Ltd.]. The extruder had three vacuum vents, and the remaining low molecular components in the resin were removed by devolatilization. Before the second vent, water was added in an amount of 2000 ppm by weight with respect to the resin, and water injection devolatilization was performed. The extruder (total 10 barrels) was set to a cylinder temperature of 220 ° C. and a screw rotation speed of 230 rpm. The resin temperature at the exit of the extruder was 262 ° C.
The polycarbonate resin that passed through the extruder was continuously filtered through a filter in a molten state, then discharged from the die into a strand, cooled with water, solidified, and pelletized with a rotary cutter.
Polycarbonate resin composition with vented twin screw extruder (Tex30α manufactured by Nippon Steel Works, Ltd., cylinder set temperature: 240 ° C.), T die (width 200 mm, set temperature: 220 ° C.), chill roll (set temperature: 90 to 120) C.) and a film-forming apparatus equipped with a winder, a film having a thickness of 38 μm was produced continuously for 2 hours, and each evaluation was performed. The results are shown in Table 1.

[Example 2]
The fourth horizontal stirring reactor was adjusted so that the molar ratio ISB / CHDM / DPC = 0.850 / 0.150 / 1.010 and the reduced viscosity of the polycarbonate resin was 0.38 dL / g to 0.40 dL / g. The same operation as in Example 1 was performed except that the operation was performed while finely adjusting the degree of vacuum.

[Example 3]
The fourth horizontal stirring reactor was adjusted so that the molar ratio ISB / TCDDM / DPC = 0.700 / 0.300 / 1.010 and the reduced viscosity of the polycarbonate resin was 0.36 dL / g to 0.38 dL / g. The same operation as in Example 1 was performed except that the operation was performed while finely adjusting the degree of vacuum.

[Comparative Example 1]
It carried out like Example 1 except not having implemented water injection devolatilization with the extruder.
The content of the compound represented by formula (3) in the used resin was large, and the compound adhered to the roll during film formation, which caused the occurrence of periodic defects on the film.

[Comparative Example 2]
The fourth horizontal stirring reactor was adjusted so that the molar ratio ISB / TCDDM / DPC = 0.700 / 0.300 / 1.010 and the reduced viscosity of the polycarbonate resin was 0.38 dL / g to 0.40 dL / g. The same operation as in Example 1 was performed except that the operation was performed while finely adjusting the degree of vacuum.
The resin used had a high melt viscosity, control of the film thickness accuracy was somewhat difficult, and a film with excellent thickness uniformity could not be obtained.

[Comparative Example 3]
The fourth horizontal stirring reactor was adjusted so that the molar ratio ISB / TCDDM / DPC = 0.700 / 0.300 / 1.010 and the reduced viscosity of the polycarbonate resin was 0.40 dL / g to 0.42 dL / g. The same operation as in Example 1 was performed except that the operation was performed while finely adjusting the degree of vacuum.
The resin used had a high melt viscosity, it was difficult to control the thickness accuracy of the film, and a film with excellent thickness uniformity could not be obtained. Furthermore, the thickness retardation of the film was a high value.

[Comparative Example 4]
The fourth horizontal stirring reactor was adjusted so that the molar ratio ISB / CHDM / DPC = 0.700 / 0.300 / 1.010 and the reduced viscosity of the polycarbonate resin was 0.42 dL / g to 0.44 dL / g. The same operation as in Example 1 was performed except that the operation was performed while finely adjusting the degree of vacuum.
Due to the low flexural modulus of the resin used, winding occurred when the film was wound around a paper core and stored.

[Comparative Example 5]
The fourth horizontal stirring reactor was adjusted so that the molar ratio ISB / CHDM / DPC = 0.500 / 0.500 / 1.010 and the reduced viscosity of the polycarbonate resin was 0.50 dL / g to 0.52 dL / g. The same operation as in Example 1 was performed except that the operation was performed while finely adjusting the degree of vacuum.
Due to the low flexural modulus of the resin used, winding occurred when the film was wound around a paper core and stored. Furthermore, curling occurred under dry heat due to the low glass transition temperature.

[Comparative Example 6]
The fourth horizontal stirring reactor was adjusted so that the molar ratio ISB / CHDM / DPC = 0.500 / 0.500 / 1.000, and the reduced viscosity of the polycarbonate resin was 0.60 dL / g to 0.62 dL / g. The same operation as in Example 1 was performed except that the operation was performed while finely adjusting the degree of vacuum.
The melt viscosity of the resin used was high, it was difficult to control the thickness accuracy of the film, a film having excellent thickness uniformity could not be obtained, and the thickness retardation of the film was high. Moreover, since the bending elastic modulus of the resin was low, winding was generated when the film was wound around a paper core and stored.

[Comparative Example 7]
Fine adjustment of the pressure reduction degree of the fourth horizontal stirring reactor was performed so that the molar ratio ISB / DPC = 1.000 / 1.000 and the reduced viscosity of the polycarbonate resin was 0.31 dL / g to 0.33 dL / g. The operation was performed in the same manner as in Example 1 except that the operation was performed.
Since the resin used had a high flexural modulus, when the film was slit, the fractured portion caused brittle fracture, from which the tear propagated throughout the film, making it difficult to collect the film. Moreover, even if the sampling was resumed after the tearing occurred, the tearing occurred again in about 30 minutes.

[Comparative Example 8]
The fourth horizontal stirring reactor was finely adjusted so that the molar ratio ISB / DPC = 1.000 / 1.030, and the reduced viscosity of the polycarbonate resin was 0.34 dL / g to 0.36 dL / g. The operation was performed in the same manner as in Example 1 except that the operation was performed.
The resin used had a high melt viscosity, control of the film thickness accuracy was somewhat difficult, and a film with excellent thickness uniformity could not be obtained.
Moreover, since the bending elastic modulus of the resin is high, when the slit is made in the film, the fracture portion causes brittle fracture, and the tear propagates from there to the entire film, making it difficult to collect the film.
Moreover, even if the sampling was resumed after the tearing occurred, the tearing occurred again in about 30 minutes.
Furthermore, the content of the compound represented by the formula (3) in the resin is large, and the compound adheres to the roll during film formation, which causes the occurrence of periodic defects on the film.

According to the present invention, a specific polycarbonate is used, the thickness uniformity is excellent, there is no film defect, no tearing occurs when slitting, no winding tightening or curling occurs when stored in roll form, An extruded film having a small phase difference and excellent productivity can be provided.

Claims (2)

A film having a structural unit derived from a dihydroxy compound represented by the following formula (1) and formed by molding a polycarbonate resin satisfying the following (a) to (d), and having a thickness of 5 μm to 40 μm .
(A) The melt viscosity measured with a capillary rheometer at 240 ° C. is 1300 Pa · s or less under the condition of a shear rate of 91.2 sec−1. (B) The glass transition temperature Tg is 115 ° C. or more and less than 150 ° C. (c ) Flexural modulus measured in accordance with ISO178 is 2900 MPa or more and less than 3300 MPa (d) Contains 10 ppm to 700 ppm by weight of a compound represented by the following formula (3)

  The film according to claim 1, wherein both the thickness retardation (Rth (589)) and in-plane retardation (R (589)) at a wavelength of 589 nm are 10 nm or less.