JP6445262B2 - Aromatic polycarbonate resin sheet or film - Google Patents

Description

  The present invention relates to an aromatic polycarbonate resin sheet or film.

  Aromatic polycarbonate resins are widely used industrially as raw materials in the OA equipment field, the electric / electronic field and the like because of their high transparency and excellent heat resistance and impact resistance. Among them, sheets and films made of aromatic polycarbonate resins are suitably used in optical applications such as front protective sheets (for example, see Patent Document 1) and light guide sheets (for example, see Patent Document 2) of liquid crystal display devices. .

  On the other hand, many studies have been made on the production method of polycarbonate resin. Among them, an aromatic polycarbonate resin derived from an aromatic dihydroxy compound such as 2,2-bis (4-hydroxyphenyl) propane (hereinafter also referred to as “bisphenol A” or “BPA”) is obtained by an interfacial polymerization method or It is industrialized by both production methods of the melt polymerization method. Of these, the interfacial polymerization method has many environmental problems.

  In addition, as a melt polymerization method, a method for producing a polycarbonate from an aromatic dihydroxy compound and diaryl carbonate, for example, by removing a by-product aromatic monohydroxy compound by transesterification in a molten state of bisphenol A and diphenyl carbonate. The method of polymerizing has been known for a long time.

  The inventors of the present invention have previously found a new method in which a chain end is formed by linking the sealing ends of a polycarbonate prepolymer with a diol compound as a method for achieving a high polymerization rate and obtaining a good quality aromatic polycarbonate resin. (For example, see Patent Document 3). According to this method, a highly polymerized aromatic polycarbonate resin having an Mw of about 30,000 to 100,000 can be produced in a short time by connecting the end of the polycarbonate prepolymer with a diol compound to extend the chain. It is supposed to be possible.

International Publication No. 2012/049977 JP 2011-180420 A International Publication No. 2012/157766

  Unlike the interfacial polymerization method, the melt polymerization method has many environmental advantages such as not using a solvent. However, the aromatic polycarbonate resin obtained by the melt polymerization method contains a large amount of naturally occurring heterogeneous structures (branched structures), has a high viscosity especially in the low shear rate region, and exhibits non-Newtonian properties. Therefore, non-uniform residual distortion is likely to occur in the sheet or film forming process in the low shear rate region, causing warping immediately after processing and deformation due to post-shrinkage difference in a high temperature environment, that is, the phase difference ratio is There was a problem of being big. In addition, deterioration of the hue (YI value) at the time of molding due to the heterogeneous structure is also a problem.

  As described above, when an aromatic polycarbonate resin obtained by melt polymerization is molded into various sheets or films, a satisfactory phase difference ratio and hue (YI value) have not been achieved yet. Therefore, the problem to be solved by the present invention is to provide an aromatic polycarbonate resin sheet or film having a small phase difference ratio and a good hue to a level that can be applied to various optical uses.

  As a result of diligent investigations to solve the above problems, the present inventors have obtained aromatic polycarbonate resins having quality advantages such as a low degree of branching and a small amount of heterogeneous structure while being produced by a melt polymerization method. The present inventors have found that a sheet or film containing can sufficiently achieve a phase difference ratio and a good hue at a level applicable to optical applications.

That is, this invention provides the aromatic polycarbonate resin sheet or film shown below.
<1> A fragrance comprising a structural unit represented by the following general formula (I) and a structural unit represented by the following general formula (III), wherein the content of the structural unit represented by the following general formula (III) is less than 2000 ppm A sheet or film containing a group polycarbonate resin.

（式中、Ｒ^１及びＲ^２は、各々独立して、ハロゲン原子、炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、炭素数６〜２０のシクロアルキル基、炭素数６〜２０のアリール基、炭素数６〜２０のシクロアルコキシ基、又は炭素数６〜２０のアリールオキシ基を表し、ｐ及びｑは、０〜４の整数を表し、Ｘは、単結合又は下記（Ｉａ）の群から選択される基を表す）

Wherein R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, or 6 carbon atoms. Represents an aryl group of -20, a cycloalkoxy group of 6-20 carbon atoms, or an aryloxy group of 6-20 carbon atoms, p and q represent an integer of 0-4, and X represents a single bond or the following ( Represents a group selected from the group of Ia)

（ここで、Ｒ^３及びＲ^４は、各々独立して、水素原子、炭素数１〜１０のアルキル基、又は炭素数６〜１０のアリール基を表すか、あるいはＲ^３とＲ^４は、相互に結合して脂肪族環を形成していてもよい）

(Here, R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, or R ³ and R ⁴ are To form an aliphatic ring)

（式中、Ｘは、上記と同義である）

(Wherein X is as defined above)

<2> The sheet or film according to <1>, wherein the YI value is 0.9 or less.
<3> The sheet or film according to <1> or <2>, wherein the retardation ratio represented by the following formula (1) is 0.35 or less.
((Re _max ) − (Re _min )) / (Re _max ) (1)

<4> The sheet or film according to any one of <1> to <3>, wherein the terminal hydroxyl group content of the aromatic polycarbonate resin is 1000 ppm or less.
<5> Any one of <1> to <4>, wherein the aromatic polycarbonate resin includes a cyclic carbonate represented by the following general formula (II), and the content thereof is 3000 ppm or less with respect to the aromatic polycarbonate resin. It is a sheet | seat or film as described in one.

（式中、Ｒａ及びＲｂは、各々独立して、水素原子、ハロゲン原子、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数１〜３０の直鎖若しくは分岐のアルキル基、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数３〜３０のシクロアルキル基、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数６〜３０のアリール基、又は酸素原子若しくはハロゲン原子を含んでいてもよい炭素数１〜１５のアルコキシ基を表すか、あるいはＲａ及びＲｂは、相互に結合して環を形成していてもよく、Ｒ^１１〜Ｒ^１４は、各々独立して、水素原子、ハロゲン原子又は炭素数１〜５の直鎖若しくは分岐のアルキル基を表し、ｎは０〜３０の整数を表す）

(In the formula, each of Ra and Rb independently represents a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, which may contain a linear or branched alkyl group having 1 to 30 carbon atoms, an oxygen atom or a halogen atom. A cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms that may contain an oxygen atom or a halogen atom, or a carbon number that may contain an oxygen atom or a halogen atom 1 to 15 represents an alkoxy group, or Ra and Rb may be bonded to each other to form a ring, and R ^{11 to} R ¹⁴ each independently represents a hydrogen atom, a halogen atom or a carbon number. 1 to 5 linear or branched alkyl groups, n represents an integer of 0 to 30)

<6> The sheet or film according to <5>, wherein the cyclic carbonate is represented by the following general formula (IIa).

（式中、Ｒａ及びＲｂは、各々独立して、水素原子、ハロゲン原子、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数１〜３０の直鎖若しくは分岐のアルキル基、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数３〜３０のシクロアルキル基、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数６〜３０のアリール基、又は酸素原子若しくはハロゲン原子を含んでいてもよい炭素数１〜１５のアルコキシ基を表すか、あるいはＲａ及びＲｂは、相互に結合して環を形成していてもよい）

(In the formula, each of Ra and Rb independently represents a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, which may contain a linear or branched alkyl group having 1 to 30 carbon atoms, an oxygen atom or a halogen atom. A cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms that may contain an oxygen atom or a halogen atom, or a carbon number that may contain an oxygen atom or a halogen atom 1 to 15 alkoxy groups are represented, or Ra and Rb may be bonded to each other to form a ring)

<7> The sheet or film according to any one of <1> to <6>, wherein the structural viscosity index N value represented by the following formula (2) of the aromatic polycarbonate resin is 1.25 or less. is there.
N value = (log (Q160 value) -log (Q10 value)) / (log160−log10) (2)
<8> The sheet or film according to any one of <1> to <7>, wherein the aromatic polycarbonate resin is obtained by a melt polymerization method.

<9> A high molecular weight process in which the aromatic polycarbonate resin has a high molecular weight by reacting a polycarbonate prepolymer with a diol compound represented by the following general formula (IV) in the presence of a transesterification catalyst; The sheet or film according to any one of <1> to <8>, obtained by a method comprising a cyclic carbonate removing step of removing at least a part of the cyclic carbonate by-produced in the step out of the reaction system. .

（式中、Ｒａ及びＲｂは、各々独立して、水素原子、ハロゲン原子、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数１〜３０の直鎖若しくは分岐のアルキル基、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数３〜３０のシクロアルキル基、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数６〜３０のアリール基、又は酸素原子若しくはハロゲン原子を含んでいてもよい炭素数１〜１５のアルコキシ基を表すか、あるいはＲａ及びＲｂは、相互に結合して環を形成していてもよく、Ｒ^１１〜Ｒ^１３は、各々独立して、水素原子、ハロゲン原子又は炭素数１〜５の直鎖若しくは分岐のアルキル基を表し、ｎは、０〜３０の整数を表す）

(In the formula, each of Ra and Rb independently represents a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, which may contain a linear or branched alkyl group having 1 to 30 carbon atoms, an oxygen atom or a halogen atom. A cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms that may contain an oxygen atom or a halogen atom, or a carbon number that may contain an oxygen atom or a halogen atom 1 to 15 represents an alkoxy group, or Ra and Rb may be bonded to each other to form a ring, and R ^{11 to} R ¹³ each independently represents a hydrogen atom, a halogen atom or a carbon number. 1 to 5 linear or branched alkyl groups, n represents an integer of 0 to 30)

<10> The sheet or film according to <9>, wherein the diol compound represented by the general formula (IV) is a compound represented by the following general formula (IVa).

（式中、Ｒａ及びＲｂは、各々独立して、水素原子、ハロゲン原子、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数１〜３０の直鎖若しくは分岐のアルキル基、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数３〜３０のシクロアルキル基、酸素原子若しくはハロゲン原子を含んでいてもよい炭素数６〜３０のアリール基、又は酸素原子若しくはハロゲン原子を含んでいてもよい炭素数１〜１５のアルコキシ基を表すか、あるいはＲａ及びＲｂは、相互に結合して環を形成していてもよい）

(In the formula, each of Ra and Rb independently represents a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, which may contain a linear or branched alkyl group having 1 to 30 carbon atoms, an oxygen atom or a halogen atom. A cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms that may contain an oxygen atom or a halogen atom, or a carbon number that may contain an oxygen atom or a halogen atom 1 to 15 alkoxy groups are represented, or Ra and Rb may be bonded to each other to form a ring)

<11> The diol compound is 2-butyl-2-ethylpropane-1,3-diol, 2,2-diisobutylpropane-1,3-diol, 2-ethyl-2-methylpropane-1,3-diol, The sheet or film according to <10>, which is at least one selected from the group consisting of 2,2-diethylpropane-1,3-diol and 2-methyl-2-propylpropane-1,3-diol. It is.
<12> The sheet or film according to any one of <1> to <11>, wherein the aromatic polycarbonate resin has a weight average molecular weight of 35,000 to 100,000.

  ADVANTAGE OF THE INVENTION According to this invention, an aromatic polycarbonate resin sheet or film with a small phase difference ratio and favorable hue to the level which can be applied to various optical uses can be provided.

  In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. . Moreover, the numerical range shown using "to" shows the range which includes the numerical value described before and behind "to" as a minimum value and a maximum value, respectively. Further, the content of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition.

<Aromatic polycarbonate resin sheet or film>
The aromatic polycarbonate resin sheet or film of the present invention (hereinafter also simply referred to as “sheet or film”) includes a structural unit represented by the following general formula (I) and a structural unit represented by the following general formula (III). The sheet or film containing an aromatic polycarbonate resin having a content of a structural unit represented by the following general formula (III) of less than 2000 ppm.

In the formula, R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, or 6 to 6 carbon atoms. Represents an aryl group having 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, p and q represent an integer of 0 to 4, and X represents a single bond or the above (Ia ) Represents a group selected from the group of R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, or R ³ and R ⁴ are bonded to each other. An aliphatic ring may be formed.

  An aromatic polycarbonate resin produced by a melt polymerization method, comprising a structural unit represented by general formula (I) as a main constituent unit, and a content of less than 2000 ppm of structural unit represented by general formula (III) By forming a sheet or film using the aromatic polycarbonate resin contained in, the formed sheet or film has a sufficiently small phase difference ratio and has an excellent hue, so it can be suitably applied to optical applications. It is.

  The aromatic polycarbonate resin sheet or film has a significantly improved retardation ratio and hue (YI value). An aromatic polycarbonate resin that can form such a sheet or film can be obtained, for example, by a method of increasing the molecular weight of the polycarbonate prepolymer by a reaction between the polycarbonate prepolymer and a linking compound containing a diol compound having a specific structure. . The aromatic polycarbonate resin obtained by such a method has a structure almost equivalent to the aromatic polycarbonate resin obtained by the conventional interfacial polymerization method, or a structure containing a partial structure derived from a very small amount of a connecting agent in some cases. It becomes.

  If the sheet | seat or film is a molded object which those skilled in the art can recognize as a sheet | seat or a film, the shape, a magnitude | size, thickness, etc. will not be restrict | limited especially, According to the objective etc., they can be selected suitably. Further, the sheet or film has a surface having a predetermined size, a molded body having a predetermined thickness in a direction perpendicular to the surface, a surface having a short direction and a long direction, and a direction perpendicular to the surface. Including a molded body that has a predetermined thickness and is continuously molded in the longitudinal direction. Moreover, the roll body wound up by the elongate direction may be sufficient as a sheet | seat or a film.

The retardation ratio of the sheet or film is calculated by the following formula (1), preferably 0.35 or less, more preferably 0.3 or less, and still more preferably 0.25 or less. The lower limit is not particularly limited, and is allowed to be, for example, 0.01 or more, preferably 0.03 or more.
((Re _max ) − (Re _min )) / (Re _max ) (1)
Here, Re _max is the maximum value of the phase difference within the measurement range, and Re _min is the minimum value of the phase difference within the measurement range. The measurement range is preferably the central portion excluding the outer edge portion of the sheet or film. A specific method for measuring the phase difference ratio will be described later.

The hue of the sheet or film is evaluated by the YI value, and the YI value is preferably 0.9 or less, more preferably 0.8 or less, and even more preferably 0.7 or less. The lower limit is not particularly limited, and is allowed to be, for example, 0.01 or more, preferably 0.03 or more.
The YI value is measured using a measurement sample solution prepared from a sheet or film. A specific sample solution preparation method and YI value measurement method will be described later.

[Aromatic polycarbonate resin]
The aromatic polycarbonate resin forming the sheet or film contains at least one structural unit represented by the general formula (I) as a main structural unit, and further contains at least one structural unit represented by the general formula (III). Including a content of less than 2000 ppm. Here, “main” means that the content of the structural unit represented by the general formula (I) in all structural units in the aromatic polycarbonate resin is 60 mol% or more, and 80 mol% or more. It is preferable that it is 90 mol% or more.

In the formula, R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, or 6 to 20 carbon atoms. An aryl group of 6 to 20 carbon atoms, or an aryloxy group of 6 to 20 carbon atoms, p and q each independently represent an integer of 0 to 4, and X is a single bond or The group selected from the group of the following (Ia) is represented. Note that * indicates a binding position.

Here, R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, or R ³ and R ⁴ are bonded to each other. Thus, an aliphatic ring may be formed.

As an aromatic dihydroxy compound induced | guided | derived to the structural unit represented by general formula (I), the compound represented by the following general formula (I ') is mentioned.

In the general formula ^{(I '), R 1,} R 2, p, q and X have the same meanings as ^{R 1, R 2, p,} q and X in each formula (I).

  Specific examples of the aromatic dihydroxy compound include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2- Bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-tert-butylphenyl) propane, 2,2-bis ( 3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-phenylphenol) ) Propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (3,5-dibromo- 4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methoxyphenyl) propane 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide, 4, , 4′-dihydroxydiphenyl sulfoxide, 4,4′-dihydroxy-3, '- dimethyl diphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfone and the like, at least one selected from the group consisting of are preferred.

  Among these, 2,2-bis (4-hydroxyphenyl) propane is preferable because of its stability as an aromatic dihydroxy compound and the availability of a grade with a small amount of impurities contained therein. .

  The aromatic polycarbonate resin may be composed of an aromatic dihydroxy compound alone, and requires a plurality of types of aromatic dihydroxy compounds for the purpose of controlling the glass transition temperature and improving fluidity. It may be configured to be used in combination.

  The aromatic polycarbonate resin further includes a structural unit represented by the general formula (III) in addition to the structural unit represented by the general formula (I).

X in the general formula (III) has the same meaning as X in the general formula (I).
The content of the structural unit represented by the general formula (III) in the aromatic polycarbonate resin is less than 2000 ppm on a mass basis in the prepolymer, preferably 1500 ppm or less, more preferably 1000 ppm or less, Preferably it is 800 ppm or less, Especially preferably, it is 700 ppm or less, Most preferably, it is 600 ppm or less. When the content of the structural unit represented by the general formula (III) is 2000 ppm or more, the degree of branching in the aromatic polycarbonate resin is excessively increased, the thermal stability is decreased, the phase difference ratio, the hue, etc. There is a tendency for the optical properties to decrease.
Moreover, these structural units of different structures are naturally occurring branched structures. Accordingly, when the content of these structural units having different structures is a predetermined amount or more, there is a tendency that the fluidity at the time of sheet or film forming process is lowered and the moldability is deteriorated. As a result, optical characteristics such as phase difference ratio and hue may be deteriorated.

  Although the minimum of the content rate of the structural unit represented by general formula (III) is not restrict | limited in particular, For example, it can be set as a detection lower limit (usually about 1 ppm). The lower limit of the content rate of the structural unit represented by the general formula (III) in the aromatic polycarbonate resin is, for example, 1 ppm or more (detection lower limit value), and in some cases, it is allowed to be 5 ppm or more, and further 10 ppm or more. .

The content of the constituent unit represented by the formula (III), to prepare a measurement sample from the sheet or film is a value of the measured mass by ^{1 H-NMR} analysis.

  The structural unit represented by the general formula (III) is a kind of heterogeneous structure that is easily generated during the production of an aromatic polycarbonate resin. When the aromatic polycarbonate resin contains a different structure at a predetermined content, melt characteristics such as melt strength tend to be improved. Thereby, an appropriate melt tension is maintained at the time of molding, drawdown is suppressed, and stable molding becomes possible. An aromatic polycarbonate resin containing a different structure at a predetermined content can be produced, for example, by a method including a step of increasing the molecular weight of an aromatic polycarbonate prepolymer using a linking agent containing a diol compound having a specific structure described later. it can.

When the aromatic polycarbonate resin is produced by a method using a linking agent containing a diol compound having a specific structure to be described later, it may contain a structural unit derived from the diol compound used in the high molecular weight process. When the aromatic polycarbonate resin includes a structural unit derived from a diol compound, the content of the structural unit derived from the diol compound with respect to the total amount of the structural unit of the aromatic polycarbonate resin is, for example, 1 mol% or less, preferably 0.8. 1 mol% or less.
The content rate of the structural unit derived from a diol compound is the value calculated | required by measuring by < ¹ > H-NMR analysis.

Furthermore, the aromatic polycarbonate resin preferably has a terminal hydroxyl group concentration of 1000 ppm or less, more preferably 800 ppm or less, still more preferably 600 ppm or less, and particularly preferably 500 ppm or less. When the terminal hydroxyl group concentration is 1000 ppm or less, hydrolysis resistance tends to be further improved.
Generally, the terminal portion of the aromatic polycarbonate resin has a structure sealed with an aromatic monohydroxy compound such as phenol, but a part thereof may be a hydroxyl group. Therefore, the terminal hydroxyl group concentration of the aromatic polycarbonate resin is the content ratio of the hydroxyl group in the aromatic polycarbonate resin. The terminal hydroxyl group concentration can be measured, for example, by preparing a measurement sample from a sheet or film and performing ¹ H-NMR analysis.

  The aromatic polycarbonate resin may contain a cyclic carbonate represented by the following general formula (II). The cyclic carbonate represented by the following general formula (II) is a known compound and can be obtained from a reagent supplier or can be easily synthesized by a known method. The cyclic carbonate represented by the following general formula (II) may be present by kneading when the aromatic polycarbonate resin is molded. Alternatively, the cyclic carbonate represented by the following general formula (II) may be a by-product produced in the production process of the aromatic polycarbonate resin. For example, the aromatic polycarbonate resin obtained by the production method described later may be a by-product of cyclic carbonate corresponding to the diol compound used as a linking agent in the production process, but even after removing this from the reaction system, A small amount of cyclic polycarbonate remains, and the cyclic polycarbonate may be contained in the aromatic polycarbonate resin finally obtained. When the cyclic carbonate is present at 3000 ppm or less in the aromatic polycarbonate resin, the fluidity of the aromatic polycarbonate resin tends to be improved. Therefore, when forming as a sheet or film, the moldability is improved, and a more optically uniform sheet or film can be obtained. In addition, when content of cyclic carbonate exceeds 3000 ppm or conversely too low, demerits, such as the mechanical strength of the sheet | seat or film obtained falling and optical physical properties worsening, may arise.

In general formula (II), Ra and Rb are each independently a hydrogen atom, a halogen atom, an oxygen atom or a linear or branched alkyl group having 1 to 30 carbon atoms which may contain a halogen atom, an oxygen atom. Alternatively, a cycloalkyl group having 3 to 30 carbon atoms which may contain a halogen atom, an aryl group having 6 to 30 carbon atoms which may contain an oxygen atom or a halogen atom, or an oxygen atom or halogen atom may be contained. It represents a good alkoxy group having 1 to 15 carbon atoms, or Ra and Rb may be bonded to each other to form a ring. As the halogen atom, a fluorine atom is preferable.
R ^{11 to} R ¹⁴ each independently represents a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 5 carbon atoms. As the halogen atom, a fluorine atom is preferable.
n represents an integer of 0 to 30, preferably an integer of 1 to 6, more preferably an integer of 1 to 3, and particularly preferably 1.

In the general formula (II), Ra and Rb are preferably each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, It represents an aryl group having 6 to 10 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, or Ra and Rb may be bonded to each other to form an alicyclic ring having 3 to 8 carbon atoms. . As the halogen atom, a fluorine atom is preferable.
R ^{11 to} R ¹⁴ are preferably each independently a hydrogen atom, a fluorine atom or a methyl group. n preferably represents an integer of 1 to 6.

In general formula (II), Ra and Rb are more preferably each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a straight chain having 1 to 4 carbon atoms. A chain or branched alkyl group. Particularly preferred specific examples include a methyl group, an ethyl group, a propyl group, an n-butyl group, and an isobutyl group. R ^{11 to} R ¹⁴ are more preferably each a hydrogen atom. n preferably represents an integer of 1 to 3.

  The cyclic carbonate represented by the general formula (II) is more preferably a compound represented by the following general formula (IIa). In general formula (IIa), Ra and Rb are respectively synonymous with Ra and Rb in general formula (II) mentioned above.

Specific examples of the cyclic carbonate represented by the general formula (II) include compounds having the following structures.

The content of the cyclic carbonate represented by the general formula (II) in the aromatic polycarbonate resin is preferably 3000 ppm or less, more preferably 1000 ppm or less, still more preferably 500 ppm or less, still more preferably 300 ppm or less, particularly preferably on a mass basis. 100 ppm or less. The lower limit of the content of the cyclic polycarbonate is usually the detection lower limit, but is preferably 0.0005 ppm, more preferably 0.005 ppm, still more preferably 0.05 ppm, and particularly preferably 0.1 ppm. It is.
By including the cyclic carbonate at a specific content, the fluidity at the time of molding and processing the aromatic polycarbonate resin is improved, and an optically more uniform film or sheet can be obtained.
In addition, the content rate of the cyclic carbonate represented by general formula (II) in aromatic polycarbonate resin prepares the sample for a measurement from a sheet | seat or a film, and is measured using GC-MS.

When the aromatic polycarbonate resin constituting the sheet or film contains a cyclic carbonate represented by the general formula (II), from the viewpoint of optical properties, moldability, etc., inclusion of the structural unit represented by the general formula (III) The weight ratio of the content of the cyclic carbonate represented by the general formula (II) with respect to the amount is, for example, 1 × 10 ^{−7 to} 6, preferably 1 × 10 ⁻³ to 1, and 0.01 to 0 .1 is more preferable.

In the aromatic polycarbonate resin, the N value (structural viscosity index) represented by the following formula (2) is preferably 1.3 or less, more preferably 1.28 or less, particularly preferably 1.25 or less, most preferably. Is 1.23 or less.
N value = (log (Q160 value) -log (Q10 value)) / (log160-log10) (2)

  In the above formula (2), the Q160 value represents the melt flow volume per unit time (ml / sec) measured at 280 degrees and a load of 160 kg, and the Q10 value is the melt flow per unit time measured at 280 degrees and a load of 10 kg. Represents volume (ml / sec).

  The structural viscosity index “N value” is an index of the degree of branching of the aromatic polycarbonate resin. In the aromatic polycarbonate resin, it is preferable that the N value is low, the content ratio of the branched structure is small, and the ratio of the linear structure is high. In general, the aromatic polycarbonate resin tends to have higher fluidity (Q value becomes higher) when the proportion of the branched structure increases in the same Mw, but the aromatic polycarbonate resin obtained by the production method described later is High fluidity (high Q value) can be achieved while keeping the N value low.

  The weight average molecular weight (Mw) of the aromatic polycarbonate resin is preferably 35,000 to 100,000, more preferably 35,000 to 80,000, particularly preferably 35,000 to 75,000, most preferably 40,000. 000-65,000. When the weight average molecular weight is within this range, the productivity is better, and the physical properties such as mechanical properties, heat resistance, and organic solvent resistance of the sheet or film are better.

The molecular weight distribution (Mw / Mn) which is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) in the aromatic polycarbonate resin is, for example, 1.9 to 2.5, and is 2.0 to 2.4. Preferably there is.
In addition, a weight average molecular weight (Mw) and a number average molecular weight (Mn) are measured as a polystyrene conversion value using GPC by preparing a measurement sample from a sheet or film.

  The aromatic polycarbonate resin constituting the sheet or film may be a resin composition further containing an additive. Examples of additives include catalyst deactivators, antioxidants, inorganic fillers, flame retardants, heat stabilizers, hydrolysis stabilizers, pigments, dyes, reinforcing agents, fillers, lubricants, crystal nucleating agents, plasticizers. Agents, fluidity improvers, antistatic agents, antibacterial agents and the like. When the resin composition contains other additives, the content is appropriately selected according to the purpose and the like. Moreover, thermoplastic resins, such as a polyethylene terephthalate (PET) and a styrene resin, may be mixed as needed.

(Method for producing aromatic polycarbonate resin)
The method for producing the aromatic polycarbonate resin contained in the sheet or film is not particularly limited. The aromatic polycarbonate resin is preferably obtained by a production method by a melt polymerization method shown below. By adopting the production method shown below, an aromatic polycarbonate resin having a low degree of branching, a low content of heterogeneous structures, and a good hue can be efficiently produced. Further, the obtained aromatic polycarbonate has a low terminal hydroxyl group concentration and can contain a cyclic carbonate having a specific structure at a desired content.

  A preferred method for producing an aromatic polycarbonate resin is to obtain a high molecular weight aromatic polycarbonate resin by reacting a polycarbonate prepolymer with a diol compound represented by the following general formula (IV) in the presence of a transesterification catalyst. It is a manufacturing method including a high molecular weight process and a cyclic carbonate removal process in which at least a part of the cyclic carbonate by-produced in the high molecular weight process is removed from the reaction system.

In the general formula (IV), Ra and Rb are each independently a hydrogen atom, a halogen atom, an oxygen atom or a C1-C30 linear or branched alkyl group which may contain a halogen atom, an oxygen atom or A cycloalkyl group having 3 to 30 carbon atoms which may contain a halogen atom, an aryl group having 6 to 30 carbon atoms which may contain an oxygen atom or a halogen atom, or an oxygen atom or a halogen atom may be contained. It represents an alkoxy group having 1 to 15 carbon atoms, or Ra and Rb may be bonded to each other to form a ring. As the halogen atom, a fluorine atom is preferable.
R ^{11 to} R ¹⁴ each independently represents a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 5 carbon atoms. As the halogen atom, a fluorine atom is preferable.
n represents an integer of 0 to 30, preferably 1 to 6, more preferably 1 to 3, and particularly preferably 1.

In general formula (IV), Ra and Rb are preferably each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, It represents an aryl group having 6 to 10 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, or Ra and Rb may be bonded to each other to form an alicyclic ring having 3 to 8 carbon atoms. . As the halogen atom, a fluorine atom is preferable. R ^{11 to} R ¹⁴ are preferably each independently a hydrogen atom, a fluorine atom or a methyl group. n preferably represents an integer of 1 to 6.

In general formula (IV), Ra and Rb are more preferably each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a straight chain having 1 to 4 carbon atoms. A chain or branched alkyl group. Particularly preferred specific examples include a methyl group, an ethyl group, a propyl group, an n-butyl group and an isobutyl group. R ^{11 to} R ¹⁴ are more preferably each a hydrogen atom. n preferably represents an integer of 1 to 3.

  More preferred as the diol compound represented by the general formula (IV) is a compound represented by the following general formula (IVa). In general formula (IVa), Ra and Rb are respectively synonymous with Ra and Rb in general formula (IV).

  In general formula (IVa), Ra and Rb are more preferably each independently a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear chain having 1 to 4 carbon atoms. Or it is a branched alkyl group, More preferably, it is a C2-C4 linear or branched alkyl group. Particularly preferred specific examples include a methyl group, an ethyl group, a propyl group, an n-butyl group, and an isobutyl group, and preferably an ethyl group, a propyl group, an n-butyl group, and an isobutyl group.

  Examples of the diol compound include 2-butyl-2-ethylpropane-1,3-diol, 2,2-diisobutylpropane-1,3-diol, 2-ethyl-2-methylpropane-1,3-diol, 2, 2-diethylpropane-1,3-diol, 2-methyl-2-propylpropane-1,3-diol, propane-1,2-diol, propane-1,3-diol, ethane-1,2-diol ( 1,2-ethylene glycol), 2,2-diisoamylpropane-1,3-diol and 2-methylpropane-1,3-diol.

Other specific examples of the diol compound include compounds having the following structural formula.

  Of these, particularly preferred are 2-butyl-2-ethylpropane-1,3-diol, 2,2-diisobutylpropane-1,3-diol, 2-ethyl-2-methylpropane-1,3-diol. It is at least one diol compound selected from the group consisting of diol, 2,2-diethylpropane-1,3-diol and 2-methyl-2-propylpropane-1,3-diol.

  The aromatic polycarbonate prepolymer (hereinafter, also simply referred to as “prepolymer” or “PP”) used in the method for producing an aromatic polycarbonate resin has a structure represented by the above general formula (I) constituting the aromatic polycarbonate resin. Is a polycondensation polymer having a main repeating unit.

  The prepolymer is a known transesterification method (melt polymerization method) in which an aromatic dihydroxy compound derived from the structural unit represented by the general formula (I) is reacted with a carbonic acid diester in the presence of a basic catalyst, or an aromatic compound. It can be easily obtained by any known interfacial polymerization method in which a dihydroxy compound is reacted with phosgene or the like in the presence of an acid binder.

  As an aromatic dihydroxy compound induced | guided | derived to the structural unit represented by the said general formula (I), the compound represented by the said general formula (V) is mentioned.

  The prepolymer may be synthesized by an interfacial polymerization method or may be synthesized by a melt polymerization method, or may be synthesized by a method such as a solid phase polymerization method or a thin film polymerization method. . Further, it is also possible to use polycarbonate recovered from used products such as used disk molded products. These polycarbonates can be mixed and used as a polymer before reaction. For example, a polycarbonate polymerized by an interfacial polymerization method and a polycarbonate polymerized by a melt polymerization method may be mixed, and a polycarbonate polymerized by a melt polymerization method or an interfacial polymerization method and a polycarbonate recovered from a used disk molded product, etc. May be used in combination.

Preferably, the prepolymer includes a terminal-capped prepolymer that satisfies a specific condition.
That is, it is preferable that at least a part of the prepolymer is sealed with a terminal group or a terminal phenyl group derived from an aromatic monohydroxy compound (hereinafter also referred to as “sealing terminal group”).

The ratio of the sealed end groups is preferably 60 mol% or more, more preferably 80 mol% or more with respect to the total amount of terminals.
Further, the concentration of the sealing end group (the ratio of the sealing end group to the total constitutional units) relative to the total number of moles of the constitutional units derived from the aromatic dihydroxy compound contained in the prepolymer is 2 mol%. As mentioned above, Preferably it is 2-20 mol%, Most preferably, it is 2-12 mol%. When the capping end group concentration is 2 mol% or more, the reaction with the diol compound proceeds rapidly. The ratio of the amount of capped end groups relative to the total amount of the prepolymer can be analyzed by ¹ H-NMR analysis of the prepolymer.

Examples of the main terminal structure of the prepolymer include a terminal end (terminal hydroxyl group) derived from an aromatic dihydroxy compound in addition to a sealed end. The total amount of these terminal structures is the total amount of terminal groups.
The terminal hydroxyl group concentration of the prepolymer can be measured by spectroscopic measurement using a Ti complex. The terminal hydroxyl group concentration can also be measured by ¹ H-NMR analysis. The terminal hydroxyl group concentration by the same evaluation is preferably 1,500 ppm or less, more preferably 1,000 ppm or less. If the concentration of the terminal hydroxyl group is less than this range or the amount of the blocked end exceeds the corresponding range, the reaction with the diol compound tends to proceed.

  The “total amount of terminal groups of the prepolymer” here is calculated assuming that, for example, if there is 0.5 mol of unbranched polycarbonate (that is, a chain polymer), the total amount of terminal groups is 1 mol. The same applies to the “total terminal group amount of the aromatic polycarbonate resin”.

  Specific examples of the sealing end group include phenyl end, cresyl end, o-tolyl end, p-tolyl end, pt-butylphenyl end, biphenyl end, o-methoxycarbonylphenyl end, p-cumylphenyl end, etc. There may be mentioned end groups.

  Among these, a terminal group composed of a low-boiling aromatic monohydroxy compound that is easily removed from the reaction system by transesterification with a diol compound is preferable, and a phenyl terminal, a p-tert-butylphenyl terminal, and the like are particularly preferable. .

  Such a blocked end group can be introduced by using a terminal terminator during the production of the prepolymer in the interfacial polymerization method. Specific examples of the terminal terminator include p-tert-butylphenol, phenol, p-cumylphenol, and long-chain alkyl-substituted phenol. The amount of the terminal terminator used can be appropriately determined according to the desired end amount of the prepolymer (that is, the desired prepolymer molecular weight), the reaction apparatus, the reaction conditions, and the like.

  In the melt polymerization method, when a prepolymer is produced, a carbonic acid diester such as diphenyl carbonate is used in an excess amount relative to the aromatic dihydroxy compound, whereby a capped end group can be introduced. Although it depends on the apparatus and reaction conditions used for the reaction, specifically, 1.00 to 1.30 mol, more preferably 1.02 to 1.20 mol of carbonic acid diester is used per 1 mol of the aromatic dihydroxy compound. . Thereby, the prepolymer which satisfy | fills the said terminal sealing amount is obtained.

  Preferably, an end-capped polycondensation polymer obtained by reacting an aromatic dihydroxy compound and a carbonic acid diester (transesterification reaction) is used as the prepolymer.

  When manufacturing a prepolymer, the polyfunctional compound which has a 3 or more functional group in 1 molecule can also be used together with said aromatic dihydroxy compound. As such a polyfunctional compound, a compound having a phenolic hydroxyl group or a carboxy group is preferably used.

  Furthermore, when manufacturing a prepolymer, it is good also as a polyester carbonate by using a dicarboxylic acid compound together with said aromatic dihydroxy compound. As the dicarboxylic acid compound, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid and the like are preferable, and these dicarboxylic acids are preferably reacted as an acid chloride or an ester compound. Moreover, when manufacturing polyester carbonate resin, it is preferable to use dicarboxylic acid in 0.5-45 mol% when the sum total of the said dihydroxy component and dicarboxylic acid component is 100 mol%. It is more preferable to use in the range of ˜40 mol%.

  As the molecular weight of the prepolymer, Mw is preferably 5,000 or more and less than 35,000. More preferably, Mw ranges from 15,000 to less than 35,000, more preferably from 20,000 to less than 35,000, and particularly preferably from 20,000 to 33,000.

  If a prepolymer having a molecular weight within this range is used, the viscosity of the prepolymer itself is low, so that it is not necessary to produce the prepolymer at high temperature, high shear, and for a long time, and / or reaction with the diol compound. There is a tendency that it is not necessary to carry out at high temperature, high shear, and long time.

  In the method for producing an aromatic polycarbonate resin, a diol compound having a specific structure is allowed to act on a prepolymer which is end-capped in the presence of a transesterification catalyst under reduced pressure conditions, thereby increasing the molecular weight of the prepolymer. Resin is produced. This reaction proceeds at high speed under mild conditions, and a high-quality aromatic polycarbonate resin is obtained.

  Here, in the method of reacting the diol compound having the specific structure, the reaction between the prepolymer and the diol compound proceeds, and a cyclic carbonate that is a cyclic body having a structure corresponding to the structure of the diol compound is by-produced. By removing by-product cyclic carbonate out of the reaction system, the prepolymer further increases in molecular weight, and finally has almost the same structure as a conventional homopolycarbonate (for example, a homopolycarbonate resin derived from bisphenol A). An aromatic polycarbonate resin is obtained.

  The high molecular weight process and the cyclic carbonate removing process are not necessarily physically and temporally separate processes, and are actually performed simultaneously. In a preferred production method, a prepolymer and a diol compound are reacted in the presence of a transesterification catalyst to obtain a high molecular weight aromatic polycarbonate resin, and at least one of cyclic carbonates by-produced in the high molecular weight reaction. A step of removing the part out of the reaction system.

  The by-product cyclic carbonate is a compound having a structure represented by the above general formula (II). The details of the structure of the cyclic carbonate produced as a by-product are as described above. The cyclic carbonate produced as a by-product has a structure corresponding to the diol compound to be used, and is considered to be a cyclic product derived from the diol compound. , Not necessarily obvious.

  The high molecular weight aromatic polycarbonate resin obtained by the production method using the diol compound represented by the general formula (IV) contains almost no structural unit derived from the diol compound, and the resin skeleton is almost the same as the homopolycarbonate resin. The same. That is, since the structural unit derived from the diol compound as the linking agent is not contained in the skeleton or is contained in a very small amount, the thermal stability is extremely high and the heat resistance is excellent. On the other hand, while having the same skeleton as a conventional homopolycarbonate resin, it can be provided with excellent quality such as a low N value, a small proportion of structural units having a different structure, and excellent hue.

  In addition, the structural unit derived from a diol compound may be contained in the frame | skeleton of the aromatic polycarbonate resin obtained by this manufacturing method. In that case, the ratio of the structural unit derived from the diol compound in the total structural unit amount of the high molecular weight aromatic polycarbonate resin is 1 mol% or less, more preferably 0.1 mol% or less.

Below, the detailed conditions of the manufacturing method of aromatic polycarbonate resin are demonstrated.
(I) Addition of diol compound The diol compound represented by the general formula (IV) is added to and mixed with the prepolymer, and a high molecular weight reaction (transesterification reaction) is performed in the high molecular weight reactor.

The amount of the diol compound used is preferably 0.01 to 1.0 mol, more preferably 0.1 to 1.0 mol, and still more preferably with respect to 1 mol of the total terminal group amount of the prepolymer. Is 0.2-0.7 mol.
However, when a diol compound having a relatively low boiling point is used, an excessive amount can be added in advance depending on the reaction conditions in consideration of the possibility that a part of the diol compound will be not involved in the reaction due to volatilization or the like. . For example, a maximum of 50 moles, preferably 10 moles, and more preferably 5 moles can be added to 1 mole of all terminal groups of the prepolymer.

  The method for adding and mixing the diol compound is not particularly limited, but when a diol compound having a relatively high boiling point (boiling point of about 350 ° C. or higher) is used, the diol compound has a degree of vacuum of 10 torr (1333 Pa or lower). It is preferable to supply directly to a high molecular weight reactor under high vacuum. More preferably, the degree of vacuum is 2.0 torr or less (267 Pa or less), more preferably 0.01 to 1 torr (1.3 to 133 Pa or less). If the degree of pressure reduction when supplying the diol compound to the high molecular weight reactor is insufficient, the prepolymer main chain cleavage reaction by the by-product (phenol) proceeds, and the reaction mixture is required to increase the high molecular weight. It may be necessary to lengthen the reaction time.

  On the other hand, when a diol compound having a relatively low boiling point (boiling point less than about 350 ° C.) is used, the prepolymer and the diol compound can be mixed at a relatively moderate degree of reduced pressure. For example, by mixing a prepolymer and a diol compound at a pressure close to normal pressure to obtain a prepolymer mixture, the prepolymer mixture is subjected to a high molecular weight reaction under a reduced pressure condition, whereby a diol compound having a relatively low boiling point is obtained. However, volatilization is minimized and the need for excessive use is eliminated.

(Ii) Transesterification reaction (high molecular weight reaction)
As temperature used for high molecular weight reaction of a prepolymer and a diol compound, the range of 240 to 320 degreeC is preferable, More preferably, it is 260 to 310 degreeC, More preferably, it is 280 to 310 degreeC.

  Further, the degree of vacuum is preferably 13 kPa (100 torr) or less, more preferably 1.3 kPa (10 torr) or less, more preferably 0.67 to 0.013 kPa (5 to 0.1 torr).

  Examples of the transesterification catalyst (hereinafter also simply referred to as “catalyst”) used in the high molecular weight reaction include basic compounds such as alkali metal compounds and / or alkaline earth metal compounds and nitrogen-containing compounds. .

  As such compounds, organic acid salts such as alkali metals and alkaline earth metals, inorganic salts, oxides, hydroxides, hydrides and alkoxides; quaternary ammonium hydroxides and salts thereof; amines and the like are preferable. These compounds can be used alone or in combination.

  Specific examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium bicarbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, potassium acetate, acetic acid. Cesium, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium tetraphenylborate, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, phosphoric acid Disodium hydrogen, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenyl phosphate, sodium gluconate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, phenol Sodium salt, potassium salt, cesium salt, lithium salt or the like is used.

  Specific examples of the alkaline earth metal compound include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium hydrogen carbonate, calcium hydrogen carbonate, strontium hydrogen carbonate, barium hydrogen carbonate, magnesium carbonate, calcium carbonate. Strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, magnesium phenyl phosphate, and the like are used.

  Specific examples of nitrogen-containing compounds include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, and other alkyl groups and / or aryl groups. Quaternary ammonium hydroxides, tertiary amines such as triethylamine, dimethylbenzylamine and triphenylamine, secondary amines such as diethylamine and dibutylamine, primary amines such as propylamine and butylamine, 2-methylimidazole Imidazoles such as 2-phenylimidazole and benzimidazole, ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, Rafeniruhou tetrabutyl ammonium, basic or basic salts such as tetraphenyl borate tetraphenyl ammonium or the like is used.

  As the transesterification catalyst, zinc, tin, zirconium and lead salts are also preferably used, and these can be used alone or in combination.

  Specific examples of the transesterification catalyst include zinc acetate, zinc benzoate, zinc 2-ethylhexanoate, tin (II) chloride, tin (IV) chloride, tin (II) acetate, tin (IV) acetate, and dibutyltin. Examples include dilaurate, dibutyltin oxide, dibutyltin dimethoxide, zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide, lead (II) acetate, and lead (IV) acetate.

These catalysts, the total 1 mol of aromatic dihydroxy compounds constituting the prepolymer, at a ratio of 1 × ¹⁰ -9 ~1 × ^{10 -3} mol, preferably 1 × ¹⁰ -7 ~1 × ^{10 -} Used in a ratio of ⁵ moles.

(Iii) Cyclic carbonate removal step The prepolymer is made high molecular weight by a high molecular weight reaction to obtain an aromatic polycarbonate resin having a desired molecular weight, and at the same time, at least a part of the by-produced cyclic carbonate is removed from the reaction system. To do. By removing at least a part of the cyclic carbonate produced as a by-product from the reaction system, the prepolymer has a higher molecular weight.

  Examples of the method for removing the cyclic carbonate include a method of distilling off from the reaction system together with an aromatic monohydroxy compound such as phenol and an unreacted diol compound which are also by-produced. The temperature when distilling from the reaction system is preferably in the range of 240 ° C to 320 ° C, more preferably 260 ° C to 310 ° C, more preferably 280 ° C to 310 ° C.

The removal of the cyclic carbonate is performed on at least a part of the cyclic carbonate by-produced. The upper limit with preferable residual amount of the cyclic carbonate byproduced is 3000 ppm. That is, in the production method using the diol compound having the structure represented by the general formula (IV) of the present invention, the cyclic carbonate having the structure represented by the general formula (II) is 3000 ppm or less, preferably 1000 ppm or less. More preferably, an aromatic polycarbonate resin containing 500 ppm or less, particularly preferably 300 ppm or less is obtained. In that case, the lower limit of the content ratio of the cyclic carbonate having the structure represented by the general formula (II) is usually a detection limit value, and is preferably 0.0005 ppm or more.
In addition, the content rate of cyclic carbonate is the value measured by GC-MS.

  The cyclic carbonate distilled out of the reaction system can then be recovered and reused (recycled) through processes such as hydrolysis and purification. The phenol distilled off together with the cyclic carbonate can also be recovered and supplied to the diphenyl carbonate production process for reuse.

(Iv) Other production conditions Due to the high molecular weight reaction between the prepolymer and the diol compound, the weight average molecular weight (Mw) of the aromatic polycarbonate resin after the reaction is 5,000 or more than the weight average molecular weight (Mw) of the prepolymer. It is preferable to increase, more preferably 10,000 or more, still more preferably 15,000 or more.

  Any known apparatus may be used in the high molecular weight reaction, the material of the kettle, etc., and the process may be performed continuously or batchwise. The reaction apparatus used for carrying out the above reaction is equipped with paddle blades, lattice blades, glasses blades, etc. even with vertical types equipped with vertical stirring blades, Max blend stirring blades, helical ribbon stirring blades, etc. It may be a horizontal type or an extruder type equipped with a screw, and it is preferable to use a reaction apparatus in which these are appropriately combined in consideration of the viscosity of the polymer. Preferably, it has a rotary blade with good horizontal stirring efficiency and a unit that can be under reduced pressure conditions. More preferably, it is a twin screw extruder or a horizontal reactor having a polymer seal and having a devolatilization structure.

  The material of the apparatus is preferably stainless steel such as SUS310, SUS316 or SUS304, or a material that does not affect the color tone of the polymer such as nickel or nitrided steel. Further, the inner side of the device (the portion in contact with the polymer) may be subjected to buffing or electropolishing, or may be subjected to metal plating such as chromium.

  A catalyst deactivator (hereinafter, also simply referred to as “deactivator”) may be applied to the high molecular weight aromatic polycarbonate resin. In general, examples of the deactivator include known acidic substances, and the deactivation of the catalyst by the addition of these deactivators is preferably performed. Specific examples of these deactivators include aromatic sulfonic acids such as p-toluenesulfonic acid, aromatic sulfonic acid esters such as butyl paratoluenesulfonic acid, tetrabutylphosphonium salt of dodecylbenzenesulfonic acid, and paratoluenesulfonic acid. Aromatic sulfonates such as tetrabutylammonium salt, stearic acid chloride, butyric acid chloride, benzoyl chloride, toluenesulfonic acid chloride, organic halides such as benzyl chloride, alkyl sulfates such as dimethyl sulfate, phosphoric acids, phosphorous acids, etc. Is mentioned.

Of these, a catalyst deactivator selected from the group consisting of paratoluenesulfonic acid, paratoluenesulfonic acid butyl, dodecylbenzenesulfonic acid tetrabutylphosphonium salt, and paratoluenesulfonic acid tetrabutylammonium salt is preferably used. .
The addition of the catalyst deactivator can be mixed with the polycarbonate resin by a conventionally known method after the completion of the high molecular weight reaction. For example, a method of appropriately mixing and kneading with an extruder, a Banbury mixer, a roll or the like after being dispersed and mixed with a high speed mixer represented by a turnbull mixer, a Henschel mixer, a ribbon blender, or a super mixer is appropriately selected.

  After catalyst deactivation, a step of devolatilizing and removing low boiling point compounds in the polymer at a pressure of 0.013 to 0.13 kPa (0.1 to 1 torr) and a temperature of 200 to 350 ° C. may be provided. A horizontal apparatus equipped with a stirring blade having excellent surface renewability, such as a paddle blade, a lattice blade, or a glasses blade, or a thin film evaporator is preferably used. A twin screw extruder or a horizontal reactor having a polymer seal and a vent structure is preferable.

[Method for producing aromatic polycarbonate resin sheet or film]
The manufacturing method of an aromatic polycarbonate resin sheet or film may be based on the manufacturing method of a general aromatic polycarbonate resin sheet or film, and does not require a particularly limited method. For example, during the polymerization reaction for producing the aromatic polycarbonate resin having the structural unit represented by the general formula (I) or at the end of the polymerization reaction, or after the catalyst used for the polymerization reaction is deactivated with a catalyst deactivator It is also possible to produce a sheet or film by adding various additives and other thermoplastic resins at any time before pelletization and mixing with an aromatic polycarbonate resin. Mixing of various additives and other thermoplastic resins may be performed as necessary, for example, may be performed simultaneously with mixing of the catalyst deactivator in the method for producing an aromatic polycarbonate resin, or may be performed separately. .

As a method for producing a sheet or film using a high molecular weight aromatic polycarbonate resin, a melt extrusion method (for example, a T-die molding method), a cast coating method (for example, a casting method), a calendar molding method, a heat Various film forming methods such as a press method can be used, and the method is not particularly limited. Preferably, a melt extrusion method is used. That is, a known melt extrusion molding machine may be used as an apparatus for producing a sheet or film by a melt extrusion method.
Hereinafter, an embodiment of a method for producing an aromatic polycarbonate resin sheet or film will be described.

  First, a resin material containing an aromatic polycarbonate resin is put into an extruder, melted and kneaded, and a sheet-like molten thermoplastic resin material is extruded from the tip (lip) of a T-die.

  Examples of the melt extruder include a single screw extruder and a twin screw extruder. Moreover, when manufacturing the multilayer thermoplastic resin film which consists of two or more layers, you may use a some melt extruder. For example, when manufacturing a three-layer thermoplastic resin film, each of the thermoplastic resin materials is melt-kneaded using three or two melt extruders, and the molten resin materials are distributed in three types and three layers. It may be distributed by a mold or a two-type three-layer distribution type feed block, and flowed into a single-layer T-type die and co-extruded, or each molten resin material is separately flowed into a multi-manifold die and 3 before the lip. It may be distributed and coextruded into a layer configuration.

  For melt extruders, a screen mesh for filtering and removing relatively large foreign matters in resin materials, a polymer filter for filtering and removing relatively small foreign matters, gels, etc. in resin materials, and resin to be extruded A gear pump or the like for stably quantifying the amount may be provided.

The T-type die is a die having a slit-like lip, and examples thereof include a feed block die, a manifold die, a fish tail die, a coat hanger die, and a screw die. When manufacturing a multilayer sheet or film, a multi-manifold die or the like may be used.
The length in the width direction of the lip of the T-type die is not particularly limited, but is preferably 1.2 to 1.5 times the product width. The opening degree of the lip may be appropriately adjusted depending on the desired product thickness, but is usually 1.01 to 10 times, preferably 1.1 to 5 times the desired product thickness. The opening degree of the lip is preferably adjusted with bolts arranged in the width direction of the T-shaped die. The lip opening does not have to be constant in the width direction. For example, the draw resonance phenomenon can be suppressed by adjusting the lip opening at the end narrower than the lip opening at the center.

  Next, the extruded sheet-shaped resin material is sandwiched and molded between two cooling rolls. The two cooling rolls may be metal rolls, may be elastic rolls, one may be a metal roll, and the other may be an elastic roll. The surface state of each roll is not particularly limited, and may be, for example, a mirror surface, or may have a pattern or unevenness.

The metal roll is not particularly limited as long as it has high rigidity, and examples thereof include a drilled roll and a spiral roll.
Examples of the elastic roll include a rubber roll and an elastic roll provided with a metal thin film on the outer peripheral portion (hereinafter sometimes referred to as a metal elastic roll), among which a metal elastic roll is preferable.

  The gap (roll gap) between the two cooling rolls is appropriately adjusted depending on the desired product thickness, and the roll gap is set so that both surfaces of the sheet-like resin material are in contact with the surface of the central portion of the cooling roll, respectively. . For this reason, when the sheet-like resin material is sandwiched between two cooling rolls, the sheet-like resin material is molded into a sheet or a film by receiving a constant pressure from the central portion of the cooling roll.

  The pressure-bonding pressure of the two cooling rolls is arbitrary within the allowable range of roll rigidity. Moreover, it can adjust suitably also about the shaping | molding speed of a sheet | seat or a film molded product.

  The structure of the sheet | seat or film shape | molded is not specifically limited, A single layer structure or a several layer structure may be sufficient. In the case of a plurality of layer structures, for example, it may be a structure of two layers, three layers, or four layers or more of the same or different thermoplastic resin materials such as a polycarbonate resin and an acrylic resin.

  The sheet or film of the present embodiment can be suitably used for an optical film in a flat panel display such as a liquid crystal display device or a plasma display, and in particular, a surface treatment such as a hard coat treatment or an antiglare treatment is applied to the surface of the base film. It can use more suitably as a base film in the optical film formed by giving.

Furthermore, since the sheet or film of the present embodiment has excellent mechanical and optical characteristics, it is used in the automotive field such as automobile nameplates and automotive interior parts, in the OA equipment field such as the electronic equipment housing, the electronic / electrical field, etc. The present invention can also be suitably applied to general industrial fields such as fields.
Specific examples include various raw materials in the electric and electronic fields, various materials in the automobile and aircraft industries, other optical equipment parts, in-vehicle supplies such as trains and automobiles, various building materials, various office automation equipment such as copiers, facsimiles, and personal computers. Part charges, various parts materials for home appliances such as TVs and microwave ovens, electronic parts applications such as connectors and IC trays, protective gear members such as helmets, protectors and protective surfaces, and members of various medical devices However, it is not limited to these.
As described above, particularly preferable uses of the aromatic polycarbonate resin sheet or film of the present invention include molded products that require a low phase difference ratio and a good hue.

  Examples The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The measured values in the examples are the analysis of the obtained aromatic polycarbonate prepolymer, aromatic polycarbonate resin and aromatic polycarbonate resin sheet or film (hereinafter, collectively referred to as “polycarbonate” when common). The physical properties were evaluated using the following method or apparatus.

(1) Weight average molecular weight (Mw) and number average molecular weight (Mn):
A calibration curve was prepared using standard polystyrene (manufactured by Tosoh Corporation, “PStQuickMP-M”) having a known molecular weight (molecular weight distribution = 1) using GPC and chloroform as a developing solvent. The elution time and molecular weight value of each peak were plotted from the measured standard polystyrene, and approximated by a cubic equation to obtain a calibration curve. The weight average molecular weight (Mw) and the number average molecular weight (Mn) were determined as polystyrene converted values by the following calculation formula.
Mw = Σ (W _i × M _i ) ÷ Σ (W _i )
Mn = Σ (N _i × M _i ) ÷ Σ (N _i )
Here, i is the i-th dividing point when the molecular weight M is divided, W _i is the i-th weight, N _i is the number of i-th molecules, and M _i is the i-th molecular weight. The molecular weight M represents a polystyrene molecular weight value at the same elution time of the calibration curve.

(2) Molecular weight distribution (Mw / Mn)
It calculated | required from the following formula from the polystyrene conversion weight average molecular weight (Mw) and the polystyrene conversion number average molecular weight (Mn).
Molecular weight distribution = Mw / Mn

[Measurement condition]
Device: HLC-8320GPC, manufactured by Tosoh Corporation
Column: Guard column: TSKguardcolumnSuperMPHZ-M x 1 Analytical column: TSKgelSuperMultiporeHZ-M x 3 Solvent; HPLC grade chloroform Injection volume: 10 μL
Sample concentration: 0.2 w / v% HPLC grade chloroform solution Solvent flow rate: 0.35 ml / min
Measurement temperature: 40 ° C
Detector; RI

(3) Terminal hydroxyl group concentration (ppm)
It measured by observing the terminal hydroxyl group from the analysis result of ¹ H-NMR.
^The concentration of the terminal hydroxyl group in the prepolymer (PP) by ¹ H-NMR was determined by dissolving 0.05 g of a resin sample in 1 ml of deuterium-substituted chloroform (containing 0.05 w / v% TMS), and performing 1H-NMR at 23 ° C. Obtained by measuring. Specifically, the terminal hydroxyl group concentration (OH) in PP was determined from the integral ratio of the hydroxyl group peak at 4.7 ppm and the phenyl and phenylene groups (terminal phenyl group and phenylene group derived from the BPA skeleton) in the vicinity of 7.0 to 7.5 ppm. Concentration) was calculated. The terminal hydroxyl group concentration in the aromatic polycarbonate resin can also be measured and calculated in the same manner.

The details of the ¹ H-NMR measurement conditions are as follows.
Measuring device: LA-500 (500MHz) manufactured by JEOL Ltd.
Measurement nucleus: ¹ H
relaxationdelay: 1s
x_angle: 45deg
x_90_width: 20μs
x_plus: 10μs
scan: 500times

(4) Terminal phenyl group concentration (sealing terminal group concentration, Ph terminal amount; mol%)
^It calculated | required by the following numerical formula from the analysis result of < ¹ > H-NMR.

Specifically, 0.05 g of a resin sample was dissolved in 1 ml of deuterium-substituted chloroform (containing 0.05 w / v% TMS), a 1H-NMR spectrum was measured at 23 ° C., and a terminal phenyl around 7.4 ppm was obtained. The amount of terminal phenyl groups and the concentration of terminal phenyl groups in PP were measured from the integral ratio of the phenylene group (derived from the BPA skeleton) in the vicinity of 7.0 to 7.3 ppm. The details of the ¹ H-NMR measurement conditions are the same as described above.

(5) Cyclic carbonate content 10 g of the aromatic polycarbonate resin as a sample was dissolved in 100 ml of dichloromethane and dropped into 1000 ml of methanol while stirring. The precipitate was filtered off and the solvent in the filtrate was removed. The obtained solid was analyzed by GC-MS under the following measurement conditions. The detection limit value under this measurement condition is 0.0005 ppm.

GC-MS measurement conditions:
Measuring device: Agilent HP6890 / 5973MSD
Column: Capillary column DB-5MS, 30 m × 0.25 mmI. D. , Film thickness 0.5μm
Temperature rising conditions: 50 ° C. (5 minhold) −300 ° C. (15 minhold), 10 ° C./min
Inlet temperature: 300 ° C., implantation amount: 1.0 μl (split ratio 25)
Ionization method: EI method Carrier gas: He, 1.0 ml / min
Aux temperature: 300 ° C
Mass scan range: 33-700
Solvent: Chloroform for HPLC Internal standard substance: 2,4,6-trimethylolphenol

(6) Content of heterogeneous structure A resin sample of 0.05 g was dissolved in 1 ml of deuterium-substituted chloroform (containing 0.05 w / v% TMS), and high temperature was measured using a nuclear magnetic resonance analyzer ¹ H-NMR at 23 ° C. The content of the heterogeneous structure in the molecular weight aromatic polycarbonate resin (PC) was measured. The content (ppm) of heterostructure (PSA) shown below was measured by assignment of ¹ H-NMR of Ha and Hb described in P.7659 in the document Polymer42 (2001) 7653-7661. The measurement conditions for ¹ H-NMR are the same as described above.

(7) N value Aromatic polycarbonate obtained by cutting an aromatic polycarbonate resin sheet or film using a Koka type flow tester CFT-500D (manufactured by Shimadzu Corporation) and drying at 120 ° C. for 5 hours. For a resin sheet or film sample, using a die having a hole diameter of 1.0 mmφ and a length of 10 mm, the melt flow volume per unit time measured at 280 ° C. and a load of 160 kg is taken as a Q160 value, and similarly measured at 280 ° C. and a load of 10 kg. The melt flow volume per unit time was taken as the Q10 value, and these were used to obtain the following equation. The Q value is the outflow amount (ml / sec) of the molten resin.
N value = (log (Q160 value) -log (Q10 value)) / (log160-log10))

(8) Hue (YI value)
A sample for measurement was prepared by dissolving an aromatic polycarbonate resin sheet or film sample in special grade dichloromethane so as to be 15% by volume, and a spectral color difference meter “SD6000” manufactured by Nippon Denshoku Industries Co., Ltd. was used at an optical path length of 50 mm. The YI value was measured.

(9) Retardation ratio Retardation measuring device "birefringence evaluation system WPA- manufactured by Photonic Lattice Co., Ltd." 100 ”was used to measure the phase difference at a measurement wavelength of 543 nm.
The phase difference ratio was calculated from the following formula using the value of the phase difference Re measured at 543 nm, the phase difference maximum value (Re _max ) and the phase difference minimum value (Re _min ) measured within the film width. .
(Re _max -Re _min ) / Re _max
The larger the phase difference ratio, the larger the phase difference variation and the non-uniform optical properties. The smaller the phase difference ratio, the smaller the phase difference variation, the more uniform the optical properties, and the heat after heating. It shows excellent shrinkage and low warpage.

  The chemical purity of the diol compounds used in the following examples and comparative examples is 98 to 99% in all, the chlorine content is 0.8 ppm or less, alkali metals, alkaline earth metals, titanium and heavy metals (iron, nickel, chromium, The contents of zinc, copper, manganese, cobalt, molybdenum, and tin are each 1 ppm or less. Chemical purity of aromatic dihydroxy compound and carbonic acid diester is 99% or more, chlorine content is 0.8 ppm or less, alkali metal, alkaline earth metal, titanium and heavy metal (iron, nickel, chromium, zinc, copper, manganese, cobalt, The contents of molybdenum and tin were each 1 ppm or less.

[Aromatic polycarbonate resin production example 1: PC-1]
66.480 kg (291.209 mol) of 2,2-bis (4-hydroxyphenyl) propane, 70.179 kg (327.610 mol) of diphenyl carbonate and 0.17 μmol / mol of cesium carbonate as catalyst (based on BPA) The number of moles) was put into a 300 L reaction equipped with a stirrer and a distillation apparatus, and the inside of the system was replaced with a nitrogen atmosphere. The degree of vacuum was adjusted to 0.046 MPa (345 torr), and the raw material was heated and melted at 160 ° C. and stirred for 1 hour.

  Thereafter, the ester exchange reaction was carried out over 9 hours while gradually raising the temperature and reducing the degree of vacuum while agglomerating and removing phenol distilled from the reaction system with a cooling tube. Finally, the inside of the system was 260 ° C., the degree of vacuum was 0.05 kPa (0.38 torr) or less, and was further maintained for 1 hour to obtain an aromatic polycarbonate prepolymer (hereinafter sometimes abbreviated as “PP-E”). It was.

The polystyrene equivalent weight average molecular weight (Mw) of the obtained aromatic polycarbonate prepolymer (PP-E) was 27900, the terminal hydroxyl group concentration (terminal OH group concentration) was 280 ppm, and the sealing terminal concentration (terminal Ph group concentration) was 5. 0.8 mol%.
The terminal hydroxyl group concentration is a value calculated from ¹ H-NMR, and indicates the terminal OH group concentration contained in the entire polymer. The terminal Ph group concentration is a value calculated from ¹ H-NMR, and is a blocked end group calculated from the total amount of phenylene groups and the amount of phenyl groups in phenyl ends (including phenyl groups substituted with hydroxyl groups). Indicates the concentration.

  Aromatic polycarbonate prepolymer (PP-E) was melted to a resin temperature of 280 ° C. by a melter (biaxial extruder), and continuously supplied to a kneader having a rotation speed of 180 rpm heated to 300 ° C. at a speed of 13300 g / hr. .

At the same time, 3000 g of 2-butyl-2-ethylpropane-1,3-diol (BEPG), which is a diol compound, is heated and melted at 75 to 80 ° C. in a coupling agent adjusting tank equipped with an anchor blade, and 0.005 mol / L 82 ml of an aqueous solution of cesium carbonate (Cs ₂ CO ₃ ) was added and stirred, followed by dehydration treatment (water content below the detection limit) at 0.1 torr for 1 hour. BEPG containing the obtained catalyst was continuously fed together with PP-E to the kneader at a rate of 124 g / hr.

BEPG is continuously supplied at a flow rate of 0.25 mol with respect to 1 mol of all terminal amounts of PP-E (sealing end group amount), and cesium carbonate (Cs ₂ CO ₃ ) as a catalyst is added to 1 mol of BPA. At a rate of 0.33 μmol.

  Subsequently, the mixture of BEPG to which PP-E and cesium carbonate were added was supplied to the horizontal stirring reactor at a flow rate of 13425 g / hr via a transport pipe kept at 280 ° C. from the kneader outlet to carry out a high molecular weight reaction. It was. The internal pressure of the horizontal stirring reactor at this time was 0.5 torr, and the resin temperature was 300 ° C.

  The liquid level was controlled so that the average residence time of the horizontal stirring reactor was 60 minutes, and phenol and cyclic carbonate (5-butyl-5-ethyl-1,3-dioxane-) produced as a by-product simultaneously with the high molecular weight reaction. 2-one) was distilled off. The stirring blade of the horizontal stirring reactor was stirred at 20 rpm.

Furthermore, with respect to the aromatic polycarbonate resin obtained after conducting the linked high molecular weight reaction in the horizontal stirring reactor, 5 ppm of paratoluene sulfonate (p-TSB) as a catalyst deactivator and octadecyl 3- ( 1000 ppm of 3,5-di-t-butyl-4-hydroxyphenyl) propionate (Irganox 1076, manufactured by BASF) was kneaded with a biaxial kneader. The obtained polycarbonate resin has a polystyrene-equivalent weight average molecular weight (Mw) of 42900, a molecular weight distribution (Mw / Mn) of 2.4, and the obtained polycarbonate resin has an N value of 1.19 and a terminal hydroxyl group concentration. 400 ppm, the amount of heterogeneous structure (PSA; a structural unit represented by the general formula (III) where X = C (CH ₃ ) ₂ ) is 500 ppm, cyclic carbonate (5-butyl-5-ethyl-1 , 3-dioxan-2-one) was 1 ppm.

[Aromatic polycarbonate resin production example 2: PC-2]
64,662 kg (283.245 mol) of 2,2-bis (4-hydroxyphenyl) propane, 63.710 kg (297.41 mol) of diphenyl carbonate and 1.0 μmol / mol of cesium carbonate as catalyst (based on BPA) The number of moles) was put into a 300 L reaction equipped with a stirrer and a distillation apparatus, and the inside of the system was replaced with a nitrogen atmosphere. The degree of vacuum was adjusted to 0.046 MPa (345 torr), the raw material was heated and melted at 160 ° C., and stirred for 1 hour.

  Thereafter, the ester exchange reaction was carried out over 10 hours while gradually raising the temperature and reducing the degree of vacuum while agglomerating and removing the phenol distilled from the reaction system with a cooling tube. Finally, the inside of the system was 260 ° C., the degree of vacuum was 0.05 kPa (0.38 torr) or less, and was further maintained for 1 hour to obtain an aromatic polycarbonate prepolymer (hereinafter sometimes abbreviated as “PP-F”). It was.

  The obtained aromatic polycarbonate prepolymer (PP-F) had a polystyrene-reduced weight average molecular weight (Mw) of 30000, an OH concentration of 1200 ppm, and a phenyl terminal concentration (Ph terminal concentration) of 2.0 mol%. The OH concentration is a value calculated from NMR, and indicates the OH group concentration contained in the entire polymer. The Ph terminal concentration is a value calculated from NMR, and represents the terminal concentration of all phenylene groups and phenyl groups (including phenyl groups substituted by hydroxyl groups) in the phenyl terminals.

  The resin temperature of the aromatic polycarbonate prepolymer (PP-F) was melted to 280 ° C. by a melter (twin screw extruder) and continuously supplied to a kneader having a rotation speed of 140 rpm heated to 300 ° C. at a speed of 13300 g / hr. .

  Subsequently, an aromatic polycarbonate prepolymer (PP-F) was supplied to the horizontal stirring reactor at a flow rate of 13300 g / hr through a transport pipe kept at 280 ° C. from the kneader outlet to carry out a high molecular weight reaction. The internal pressure of the horizontal stirring reactor at this time was 0.5 torr, and the resin temperature was 300 ° C.

  The liquid level was controlled so that the average residence time in the horizontal stirring reactor was 120 minutes, and phenol produced as a by-product was distilled off simultaneously with the high molecular weight reaction. The stirring blade of the horizontal stirring reactor was stirred at 20 rpm.

  Furthermore, 5 ppm of p-toluenesulfonic acid butyl (p-TSB) as a catalyst deactivator and octadecyl 3- (3,3) as an antioxidant were obtained with respect to the polycarbonate resin obtained after conducting a linked high molecular weight reaction in a horizontal stirring reactor. 1000 ppm of 5-di-t-butyl-4-hydroxyphenyl) propionate (Irganox 1076, manufactured by BASF) was kneaded with a biaxial kneader. The polystyrene equivalent weight average molecular weight (Mw) of the obtained polycarbonate resin was 44700, the molecular weight distribution (Mw / Mn) was 2.6, the N value of the obtained polycarbonate resin was 1.29, the terminal hydroxyl group concentration was 1100 ppm, The amount of heterogeneous structure (PSA) was 2000 ppm.

[Example 1]
The aromatic polycarbonate resin PC-1 obtained in Production Example 1 was used for molding under the following conditions to obtain an aromatic polycarbonate resin sheet.
Film forming machine: Toshiba Machine Co., Ltd. film testing machine SPU-03026W
Extruder: Vent type 26mm Ф biaxial screw Dies: Effective width 330mm
Extrusion temperature: 260 ° C
Discharge rate: 15kg / h
Molding method: Non-roll pressing molding Film thickness: 100 μm
About the obtained aromatic polycarbonate resin sheet, retardation ratio and hue were evaluated. The evaluation results are shown in the table below.

[Comparative Example 1]
In the comparative example 1, except having changed resin into PC-2, it shape | molded similarly to Example 1, and evaluated similarly.

  From Table 1, it can be seen that the aromatic polycarbonate resin sheet or film of the present invention is excellent in optical properties, particularly in retardation ratio and hue.

Claims (10)

An aromatic polycarbonate resin containing a structural unit represented by the following general formula (I) and a structural unit represented by the following general formula (III), wherein the content of the structural unit represented by the following general formula (III) is less than 2000 ppm hints, YI value Ri der 0.7, the phase difference ratio represented by the following formula (1) is 0.25 or less, an optical sheet or film.

Wherein R ¹ and R ² are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, or 6 carbon atoms. Represents an aryl group of -20, a cycloalkoxy group of 6-20 carbon atoms, or an aryloxy group of 6-20 carbon atoms, p and q represent an integer of 0-4, and X represents a single bond or the following ( Represents a group selected from the group of Ia)

(Here, R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms, or R ³ and R ⁴ are To form an aliphatic ring)

(Wherein X is as defined above)
((Re _max ) − (Re _min )) / (Re _max ) (1) The optical sheet or film according to claim 1, wherein the terminal hydroxyl group content of the aromatic polycarbonate resin is 1000 ppm or less. The optical sheet or film according to claim 1 or 2 , wherein the aromatic polycarbonate resin contains a cyclic carbonate represented by the following general formula (II), and the content thereof is 3000 ppm or less with respect to the aromatic polycarbonate resin. .

(In the formula, each of Ra and Rb independently represents a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, which may contain a linear or branched alkyl group having 1 to 30 carbon atoms, an oxygen atom or a halogen atom. A cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms that may contain an oxygen atom or a halogen atom, or a carbon number that may contain an oxygen atom or a halogen atom 1 to 15 represents an alkoxy group, or Ra and Rb may be bonded to each other to form a ring, and R ^{11 to} R ¹⁴ each independently represents a hydrogen atom, a halogen atom or a carbon number. 1 to 5 linear or branched alkyl groups, n represents an integer of 0 to 30) The optical sheet or film according to claim 3 , wherein the cyclic carbonate is represented by the following general formula (IIa).

(In the formula, each of Ra and Rb independently represents a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, which may contain a linear or branched alkyl group having 1 to 30 carbon atoms, an oxygen atom or a halogen atom. A cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms that may contain an oxygen atom or a halogen atom, or a carbon number that may contain an oxygen atom or a halogen atom 1 to 15 alkoxy groups are represented, or Ra and Rb may be bonded to each other to form a ring) The optical sheet or film according to any one of claims 1 to 4 , wherein the structural viscosity index N value represented by the following formula (2) of the aromatic polycarbonate resin is 1.25 or less.
N value = (log (Q160 value) -log (Q10 value)) / (log160−log10) (2) The optical sheet or film according to any one of claims 1 to 5 , wherein the aromatic polycarbonate resin is obtained by a melt polymerization method. The aromatic polycarbonate resin comprises a high molecular weight process in which a polycarbonate prepolymer and a diol compound represented by the following general formula (IV) are reacted in the presence of a transesterification catalyst to increase the molecular weight; The optical sheet or film according to any one of claims 1 to 6 , obtained by a production method comprising a cyclic carbonate removing step of removing at least a part of the produced cyclic carbonate to the outside of the reaction system.

(In the formula, each of Ra and Rb independently represents a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, which may contain a linear or branched alkyl group having 1 to 30 carbon atoms, an oxygen atom or a halogen atom. A cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms that may contain an oxygen atom or a halogen atom, or a carbon number that may contain an oxygen atom or a halogen atom 1 to 15 represents an alkoxy group, or Ra and Rb may be bonded to each other to form a ring, and R ^{11 to} R ¹⁴ each independently represents a hydrogen atom, a halogen atom or a carbon number. 1 to 5 linear or branched alkyl groups, n represents an integer of 0 to 30) The optical sheet or film according to claim 7 , wherein the diol compound represented by the general formula (IV) is a compound represented by the following general formula (IVa).

(In the formula, each of Ra and Rb independently represents a hydrogen atom, a halogen atom, an oxygen atom or a halogen atom, which may contain a linear or branched alkyl group having 1 to 30 carbon atoms, an oxygen atom or a halogen atom. A cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms that may contain an oxygen atom or a halogen atom, or a carbon number that may contain an oxygen atom or a halogen atom 1 to 15 alkoxy groups are represented, or Ra and Rb may be bonded to each other to form a ring) The diol compound is 2-butyl-2-ethylpropane-1,3-diol, 2,2-diisobutylpropane-1,3-diol, 2-ethyl-2-methylpropane-1,3-diol, 2,2 The optical sheet or film according to claim 8 , which is at least one selected from the group consisting of diethylpropane-1,3-diol and 2-methyl-2-propylpropane-1,3-diol. The optical sheet or film according to any one of claims 1 to 9 , wherein the aromatic polycarbonate resin has a weight average molecular weight of 35,000 to 100,000.