JP2011105932A - Polycarbonate resin, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain polycarbonate resin which gives a molded article of high surface hardness. <P>SOLUTION: The polycarbonate resin includes at least a repeating unit represented by formula (1) in the molecule, and satisfies the following (a)-(c): (a) the pencil hardness is equal to or greater than HB; (b) the melt volume flow rate under a specific condition falls into a definite range; and (c) the specific melt volume flow rate ratio under a specific temperature and different loads falls into a definite range. In formula (1), X is a single bond, (non)substituted alkylene, (non)substituted alkylidene, (non)substituted sulfur atom, or oxygen atom. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polycarbonate resin and a method for producing the same.

  Polycarbonate resins are excellent in mechanical properties such as impact resistance, heat resistance, moldability, transparency and the like, and are widely used for various mechanical parts, optical disks, automobile parts and the like. For example, Patent Document 1 was obtained by polymerizing an aromatic bisphenol having an alkyl substituent introduced into an aromatic ring such as 2,2-bis- (4-hydroxy-3-methylphenyl) propane and diphenyl carbonate. Aromatic polycarbonate resins are described.

JP-A-64-069625

However, although polycarbonate resin is excellent in moldability and the like, it has a defect that the surface hardness is low and the surface is easily damaged when formed into a molded product. For example, the aromatic polycarbonate resin described in Patent Document 1 described above has improved surface hardness but insufficient moldability and color tone.
An object of the present invention is to provide a polycarbonate resin having a high surface hardness and excellent moldability and color tone, and a method for producing the same.

  Therefore, as a result of intensive studies, the inventor has selected, for example, a specific dihydroxy compound as a raw material, reduced a specific amount of impurities, and optimized polycondensation conditions. It was found that the color tone was improved, and the present invention was completed based on such knowledge.

That is, according to the present invention, there are provided a polycarbonate resin according to the following [1] to [12] and a method for producing the same.
[1] A polycarbonate resin having a repeating unit represented by the following general formula (1) in the molecule and satisfying the following (a) to (c):

(In General Formula (1), R ₁ and R ₂ each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group, and R ₃ and R ₄ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and X is a single bond, substituted or unsubstituted. An alkylene group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)
(A) The pencil hardness according to ISO15184 is HB or higher.
(B) conforms to ISO 1133, 300 ° C., in the range melt volume flow rate (MVR) of ^{1 cm} 3/10 min ~15cm ^3/10 min at 1.2kg load.
(C) In accordance with ISO 1133, melt volume flow rate (MVR (280 ° C., 21.6 kg load)) at 280 ° C. and 21.6 kg load and melt volume flow rate (MVR (280) at 280 ° C. and 2.16 kg load) The flow rate ratio (MVR-R) obtained from the following formula is in the range of 18 to 45.
Flow rate ratio (MVR-R) = MVR (280 ° C., 21.6 kg load) / MVR (280 ° C., 2.16 kg load)

[2] A substituted or unsubstituted alkylidene group represented by X in the general formula (1) is

The polycarbonate resin according to [1], wherein
(R ₅ and R ₆ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and Z is substituted or unsubstituted. Represents an alkylene group having 4 to 20 carbon atoms.)
[3] The polycarbonate resin according to [1] or [2], wherein the methylene chloride solution prepared at a concentration of 0.1 g / mL has an APHA color of 18 or less at a wavelength of 420 nm.
[4] According to any one of [1] to [3], the tensile elastic modulus at 23 ° C. and a tensile speed of 1 mm / min is 1,800 MPa or more in accordance with ISO527-2 / 1A / 1. Polycarbonate resin.
[5] The polycarbonate resin according to any one of [1] to [4], which contains 50% by weight or more of the repeating unit represented by the general formula (1).
[6] The polycarbonate resin according to any one of [1] to [5], wherein R ₃ and R ₄ in the general formula (1) are hydrogen atoms.
[7] Any one of [1] to [6], obtained by polycondensation of a dihydroxy compound and a carbonyl compound, wherein the dihydroxy compound contains a dihydroxy compound represented by the following general formula (2) The polycarbonate resin described in 1.

(R ₁ , R ₂ and X in the general formula (2) have the same meanings as the general formula (1).)
[8] The dihydroxy compound further contains a dihydroxy compound represented by the following general formula (3), and the amount of the dihydroxy compound represented by the general formula (3) is represented by the general formula (2). The polycarbonate resin according to [7], which is 5 ppm or less based on the amount of the dihydroxy compound.

(R ₁ , R ₂ and X in the general formula (3) have the same meanings as in the general formula (1), and R ₃ is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or Represents an unsubstituted aryl group.)
[9] The total amount of chloride ion, nitrite ion, nitrate ion, phosphate ion and sulfate ion contained in the dihydroxy compound represented by the general formula (2) is 10 ppm or less [7] ] Or polycarbonate resin according to [8].
[10] The chloride ion contained in the dihydroxy compound represented by the general formula (2) is 1,000 ppb or less, the total of nitrite ion and nitrate ion is 500 ppb or less, and phosphate ion and sulfuric acid. The polycarbonate resin according to [9], wherein the total number of ions is 200 ppb or less.
[11] The polycarbonate resin according to any one of [7] to [10], wherein the carbonyl compound is a carbonic acid diester compound.

[12] A method for producing a polycarbonate resin according to any one of [1] to [11], wherein the aromatic dihydroxy compound and the carbonic acid diester are used in the presence of an alkali metal catalyst and / or an alkaline earth metal catalyst. In the transesterification reaction, the amount of the alkali metal catalyst and / or the alkaline earth metal catalyst used is in the range of 0.1 μmol to 5 μmol per 1 mol of the aromatic dihydroxy compound. Manufacturing method.

According to the present invention, a polycarbonate resin having excellent moldability, high surface hardness, and excellent color tone can be obtained.
Moreover, the polycarbonate resin obtained by this invention also shows high flame retardance. By using such a polycarbonate resin, it is possible to obtain a molded product that is transparent, hardly damaged, and exhibits high flame retardancy.

¹ is a ¹ H-NMR spectrum of a copolymer of bisphenol A and 2,2-bis (3-methyl-4-hydroxyphenyl) propane.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary. The drawings used are for explaining the present embodiment and do not represent the actual size.

<Polycarbonate resin>
Examples of the polycarbonate resin to which the present embodiment is applied include those having at least a repeating unit represented by the following general formula (1) in the molecule.

Here, in the general formula (1), R ₁ and R ₂ each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group, and R ₃ And R ₄ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group. _{Incidentally,} the number of carbon atoms in _{R 1, R 2, R 3} , R 4 denotes a number of carbon atoms of the alkyl group portion excluding the substituent.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ₁ and R ₂ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec -Butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. Examples of the substituted or unsubstituted aryl group include: A phenyl group, a benzyl group, a tolyl group, 4-methylphenyl group, a naphthyl group, etc. are mentioned.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ₃ and R ₄ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec -Butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. Examples of the substituted or unsubstituted aryl group include: A phenyl group, a benzyl group, a tolyl group, 4-methylphenyl group, a naphthyl group, etc. are mentioned.
Among these, R ₁ and R ₂ are preferably a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and particularly preferably a methyl group. R ₃ and R ₄ are preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and particularly preferably a hydrogen atom. Here, the bonding positions of R ₁ , R ₂ , R ₃ , and R ₄ in the general formula (1) are arbitrarily selected from 2-position, 3-position, 5-position, and 6-position with respect to X on each phenyl ring. And preferably the 3rd and 5th positions.

In the general formula (1), X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom. Examples of the substituted or unsubstituted sulfur atom include —S— and —SO ₂ —.
In addition, a substituted or unsubstituted alkylidene group is

Indicates. Here, R ₅ and R ₆ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and Z is substituted or unsubstituted. A substituted alkylene group having 4 to 20 carbon atoms is shown.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms of R ₅ and R ₆ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec- Examples include a butyl group, a tert-butyl group, an n-pentyl group, a sec-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. Examples of the substituted or unsubstituted aryl group include phenyl Group, benzyl group, tolyl group, 4-methylphenyl group, naphthyl group and the like.
Among these, R ₅ and R ₆ are preferably a methyl group, an ethyl group, an n-propyl group, or a 4-methylphenyl group, and particularly preferably a methyl group.
In general formula (1), Z is bonded to the carbon bonding two phenyl groups to form a substituted or unsubstituted divalent carbocycle. Examples of the divalent carbocycle include a cycloalkylidene group such as a cyclopentylidene group, a cyclohexylidene group, a cycloheptylidene group, a cyclododecylidene group or an adamantylidene group (preferably having a carbon number of 5 to 5). Examples of the substituted group include those having these methyl substituents and ethyl substituents. Among these, a cyclohexylidene group and a methyl-substituted product of a cyclohexylidene group are preferable.

In the present invention, it is necessary to contain at least the repeating unit represented by the general formula (1). As a preferable range, the repeating unit of the general formula (1) is 30% by weight or more, more preferably 40% by weight or more, and further preferably 50% by weight or more in the total aromatic diol structural unit. When the repeating unit of the general formula (1) is less than 30% by weight, the surface hardness and fluidity are inferior.
As a method of containing the repeating unit represented by the general formula (1), at least an aromatic dihydroxy compound represented by the general formula (2) is used as a starting material to form a polycarbonate resin by an interfacial polymerization method or a transesterification method. Can be achieved. The aromatic dihydroxy compound represented by the general formula (2) may be contained alone or in combination of two or more, and may contain an aromatic dihydroxy compound such as bisphenol A other than the general formula (2). good.
The form of the polycarbonate resin may be any of a homopolymer, a copolymer, and a polymer blend.

Furthermore, the polycarbonate resin to which this embodiment is applied includes those satisfying the physical properties shown in the following (a) to (c).
(A) The pencil hardness according to ISO15184 is HB or higher.
The pencil hardness of the polycarbonate resin is preferably F or more, more preferably H or more, and particularly preferably 2H or more. If the pencil hardness of the polycarbonate resin is too small, the surface of the molded product tends to be damaged when it is formed.

(B) conforms to ISO 1133, 300 ° C., in the range melt volume flow rate (MVR) of ^{1 cm} 3/10 min ~15cm ^3/10 min at 1.2kg load.
Melt volume flow rate of the polycarbonate resin (MVR) is preferably a ^{1 cm} 3/10 min ~14cm ^3/10 min, more preferably from ^{1 cm} 3/10 min ~13cm ^3/10 min. If the melt volume flow rate (MVR) of the polycarbonate resin is excessively small, the fluidity in the molten state tends to deteriorate and the moldability tends to deteriorate. If the melt volume flow rate (MVR) is excessively large, the fluidity in the molten state is good, but on the other hand, the flow is too good and there is a tendency to cause molding defects.

(C) In accordance with ISO 1133, melt volume flow rate (MVR (280 ° C., 21.6 kg load)) at 280 ° C. and 21.6 kg load and melt volume flow rate (MVR (280) at 280 ° C. and 2.16 kg load) The flow rate ratio (MVR-R) obtained from the following formula is in the range of 18 to 45.
Flow rate ratio (MVR-R) = MVR (280 ° C., 21.6 kg load) / MVR (280 ° C., 2.16 kg load)
Here, the technical significance of the flow rate ratio (MVR-R) indicates the degree of molecular entanglement and the degree of branching of the polymer chain, and is used as an index of melting characteristics such as melt tension. In the present embodiment, the flow rate ratio (MVR-R) is preferably in the range of 18 to 40, more preferably in the range of 18 to 35. If the flow rate ratio (MVR-R) of the polycarbonate resin is excessively small, melt tension cannot be obtained, and the target polycarbonate resin having excellent moldability tends not to be obtained. When the flow rate ratio (MVR-R) is excessively large, the melt tension becomes large, the fluidity is deteriorated, and as a result, the moldability tends to be deteriorated.

  In the present invention, it is necessary to satisfy both the melt volume flow rate (MVR) and the flow rate ratio (MVR-R). And the polycarbonate resin which is excellent in moldability and also exhibits flame retardancy is obtained.

  The polycarbonate resin to which this embodiment is applied preferably has an APHA color of 18 or less at a wavelength of 420 nm of a methylene chloride solution prepared to a concentration of 0.1 g / mL. The APHA color is more preferably 16 or less, and particularly preferably 10 or less. If the APHA color is excessively large, the color of the polycarbonate resin tends to be yellowish, which is not preferable. Here, the technical significance of the APHA color at a wavelength of 420 nm of a methylene chloride solution prepared to a concentration of 0.1 g / mL indicates the degree of coloration of the polycarbonate resin, and is particularly used as an index of yellowness.

  The polycarbonate resin to which this embodiment is applied preferably conforms to ISO 527-2 / 1A / 1 and has a tensile modulus of elasticity of 1,800 MPa or more at 23 ° C. and a tensile speed of 1 mm / min. The tensile elastic modulus is more preferably 2,000 MPa or more, and particularly preferably 2,400 MPa or more. Here, the technical significance of the tensile modulus at 23 ° C. and a tensile speed of 1 mm / min indicates the rigidity of the material in the tensile state, and is generally used as an index of the strength of the resin under tensile deformation conditions. If the tensile modulus of the polycarbonate resin is too small, it tends to be brittle with respect to deformation and the surface hardness tends to be small, which is not preferable.

<Production method of polycarbonate resin>
Next, a method for producing a polycarbonate resin to which the present embodiment is applied will be described.
The polycarbonate resin to which the present embodiment is applied is obtained by polymerization using an aromatic dihydroxy compound and a carbonyl compound, specifically, an organic phase in which the aromatic dihydroxy compound and carbonyl chloride are not arbitrarily mixed. Polycarbonate by producing an interfacial polycondensation method in which a polycarbonate resin is produced by reacting at the interface between a water phase and an aqueous phase, and by transesterifying an aromatic dihydroxy compound and a carbonyl compound in a molten state in the presence of a transesterification catalyst. There is a melt polycondensation method for producing a resin (hereinafter abbreviated as a melting method).
Among the above methods, it is preferable to produce a polycarbonate resin by a melting method. Hereinafter, a method for producing a polycarbonate resin by a melting method in the presence of an ester exchange catalyst using an aromatic dihydroxy compound and a carbonyl compound as raw materials will be described.

(Aromatic dihydroxy compounds)
Examples of the aromatic dihydroxy compound used in the present embodiment include aromatic dihydroxy compounds represented by the following general formula (2). In the present embodiment, the dihydroxy compound represented by the following general formula (2) is usually 50% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more based on the wholly aromatic dihydroxy compound. used. When the ratio of the general formula (2) is excessively low, the surface hardness becomes low, which is not preferable.

Here, R ₁ , R ₂ and X in the general formula (2) have the same meaning as in the general formula (1).

Specific examples of the dihydroxy compound represented by the general formula (2) include 2,2-bis (4-hydroxy-3-methylphenyl) propane and 1,1-bis (4-hydroxy-3-methylphenyl). ) Cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) -3,5,5-trimethylcyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) adamantane, 1,4-bis (4-hydroxy-3-methylphenyl) adamantane, 2,2-bis (4-hydroxy-3-ethylphenyl) propane, 2,2-bis (4-hydroxy-3-tert-butylphenyl) propane, 2, 2-bis (4-hydroxy-3-cyclohexylphenyl) propane, 2,2-bis (4-hydroxy-3-phenylphenyl) propa 5,5-bis (4-hydroxy-3-methylphenyl) hexahydro-4,7-methanoindane, 2,2-bis (4-hydroxy-3-methylphenyl) sulfone, 2,2-bis (4-hydroxy) -3-methylphenyl) sulfide, 3,3′-dimethylbiphenol, and the like.
Among these, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-) Methylphenyl) -3,5,5-trimethylcyclohexane, 5,5-bis (4-hydroxy-3-methylphenyl) hexahydro-4,7-methanoindane, 3,3′-dimethylbiphenol is preferred, Bis (3-methyl-4-hydroxyphenyl) propane is particularly preferred. These dihydroxy compounds represented by the general formula (2) can be used alone or in admixture of two or more. In the above general formula (2), the preferred structures of R ₁ , R ₂ and X and the preferred bonding positions of R ₁ and R _{2 with} respect to X on the phenyl ring are the same as in general formula (1). The structures and bonding positions of R ₁ , R ₂ and X are preferably the same as those in the general formula (1).

The dihydroxy compound represented by the general formula (2) may contain an anion. Examples of the anion include chloride ion, nitrite ion, nitrate ion, phosphate ion, sulfate ion and the like. In the present embodiment, the amount of anion contained in the dihydroxy compound represented by the general formula (2) is usually 10 ppm as the total amount of chloride ion, nitrite ion, nitrate ion, phosphate ion and sulfate ion. Hereinafter, it is preferably 5 ppm or less, more preferably 3 ppm or less, and particularly preferably 1 ppm or less.
If the amount of anion contained in the dihydroxy compound represented by the general formula (2) is excessively large, the polymerization reactivity may be affected, or the color tone of the obtained polycarbonate resin may be deteriorated. .

Among the anions contained in the dihydroxy compound represented by the general formula (2), the amount of chloride ions is preferably 1,000 ppb or less, more preferably 800 ppb or less.
In addition, the total amount of nitrite ions and nitrate ions is preferably 500 ppb or less. The total amount of nitrite ions and nitrate ions is more preferably 400 ppb or less.
Furthermore, the total amount of phosphate ions and sulfate ions is preferably 200 ppb or less. The total amount of phosphate ions and sulfate ions is more preferably 100 ppb or less. It is preferable that the amount of these chloride ions, and the total amount of nitrite ions, nitrate ions, and the total amount of phosphate ions and sulfate ions all satisfy the above range. This is not preferable because it affects the color tone of the polycarbonate resin.

  When the anion exceeds the desired range, the present invention can be carried out by reducing the anion by appropriately using a technique such as washing, recrystallization, sublimation or the like as a method for keeping the anion within the desired range. It can be used as a dihydroxy compound.

  The aromatic dihydroxy compound used in the present embodiment may further contain a dihydroxy compound represented by the following general formula (3).

Here, R ₁ , R ₂ and X in the general formula (3) have the same meaning as in the general formula (1), and R ₃ is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or A substituted or unsubstituted aryl group is shown.
Examples of the substituted or unsubstituted alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. , N-pentyl group, sec-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. Examples of the substituted or unsubstituted aryl group include a phenyl group, a benzyl group, a tolyl group, a 4-methylphenyl group, and a naphthyl group.

Specific examples of the dihydroxy compound represented by the general formula (3) include 4- [1- (4-hydroxy-3-methylphenyl) -1-methylethyl] -2,6-dimethylphenol, 4- [1- (3-Ethyl-4-hydroxyphenyl) -1-methylethyl] -2,6-dimethylphenol, 4- [1- (3-tert-butyl-4-hydroxyphenyl) -1-methylethyl] -2,6-dimethylphenol and the like.
Among these, 4- [1- (4-hydroxy-3-methylphenyl) -1-methylethyl] -2,6-dimethylphenol is preferable. In the general formula (3), preferred structures of R ₁ , R ₂ , R ₃ , and X and preferred bonding positions of R ₁ , R ₂ , and R ₃ with respect to X on the phenyl ring are the same as those in the general formula (1). is there. The structures and bonding positions of these R ₁ , R ₂ , R ₃ and X are preferably the same as those in the general formula (1).

The amount of the dihydroxy compound represented by the general formula (3) contained in the aromatic dihydroxy compound is 5 ppm or less, preferably 3 ppm or less, more preferably based on the amount of the dihydroxy compound represented by the general formula (2). Is 1 ppm or less.
When the amount of the dihydroxy compound represented by the general formula (3) is excessively large, the obtained polycarbonate resin tends to be colored, which is not preferable. Moreover, when there is too little content of the dihydroxy compound represented by General formula (3), it needs to refine | purify too much and is not economically preferable.

In the present invention, the dihydroxy compound represented by the general formula (3) is usually 50% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more with respect to the wholly aromatic dihydroxy compound. In addition to the dihydroxy compound represented by the general formula (3), another dihydroxy compound may be used.
Such a dihydroxy compound may be any dihydroxy compound such as an aromatic dihydroxy compound or an aliphatic dihydroxy compound, but is preferably bisphenol A.

(Carbonyl compound)
As the carbonyl compound used in the present embodiment, a carbonic acid diester compound is preferable. Examples of the carbonic acid diester compound include compounds represented by the following general formula (4).

Here, in the general formula (4), A ′ is an optionally substituted linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. Two A ′ may be the same or different from each other.
In addition, as a substituent on A ′, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, and an ester group Amide group, nitro group and the like.

Specific examples of the carbonic acid diester compound include substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate, and dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate.
Among these, diphenyl carbonate (hereinafter sometimes abbreviated as DPC) and substituted diphenyl carbonate are preferable. These carbonic acid diesters can be used alone or in admixture of two or more.

Moreover, the amount of the carbonic acid diester compound is preferably 50 mol% or less, more preferably 30 mol% or less, and may be substituted with dicarboxylic acid or dicarboxylic acid ester.
Typical dicarboxylic acids or dicarboxylic acid esters include terephthalic acid, isophthalic acid, diphenyl terephthalate, diphenyl isophthalate, and the like. When substituted with such a dicarboxylic acid or dicarboxylic acid ester, a polyester carbonate is obtained.

In the present embodiment, these carbonic acid diester compounds (including the above-mentioned substituted dicarboxylic acid or dicarboxylic acid ester; the same shall apply hereinafter) are used in excess with respect to the aromatic dihydroxy compound.
That is, the aromatic dihydroxy compound is usually used in a molar ratio of carbonic acid diester compound 1.01 to carbonic acid diester compound 1.30, preferably 1.02 to 1.20. When the molar ratio is excessively small, the terminal OH groups of the obtained polycarbonate resin increase, and the thermal stability tends to deteriorate. In addition, if the molar ratio is excessively large, the transesterification reaction rate decreases and production of a polycarbonate resin having a desired molecular weight tends to be difficult, and the residual amount of the carbonic acid diester compound in the resin increases. This may cause odors during molding or when formed into a molded product, which is not preferable.

(Transesterification catalyst)
Examples of the transesterification catalyst used in the present embodiment include a catalyst that is usually used when producing a polycarbonate resin by a transesterification method, and is not particularly limited. In general, for example, basic compounds such as alkali metal compounds, alkaline earth metal compounds, beryllium compounds, magnesium compounds, basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds can be used. Among these, alkali metal compounds and alkaline earth metal compounds are desirable for practical use. These transesterification catalysts may be used alone or in combination of two or more.
The amount of the transesterification catalyst used is usually in the range of 0.001 to 1000 μmol, preferably 0.1 to 300 μmol, relative to 1 mol of the aromatic dihydroxy compound.
In addition, when an alkali metal compound (alkali metal catalyst) or an alkaline earth metal compound (alkaline earth metal catalyst) is used as the transesterification catalyst, the amount of the alkali metal catalyst and / or alkaline earth metal catalyst used is a fragrance. The amount is in the range of 0.01 μmol to 10 μmol, preferably 0.1 μmol to 5 μmol, per mol of the group dihydroxy compound.

Examples of the alkali metal compound include inorganic alkali metal compounds such as alkali metal hydroxides, carbonates and hydrogencarbonate compounds; organic alkali metal compounds such as salts with alkali metal alcohols, phenols and organic carboxylic acids. It is done. Here, as an alkali metal, lithium, sodium, potassium, rubidium, cesium etc. are mentioned, for example.
Among these alkali metal compounds, cesium compounds are preferable, and cesium carbonate, cesium hydrogen carbonate, and cesium hydroxide are particularly preferable.

  Examples of the alkaline earth metal compound include inorganic alkaline earth metal compounds such as alkaline earth metal hydroxides and carbonates; alkaline earth metal alcohols, phenols, salts with organic carboxylic acids, and the like. It is done. Here, examples of the alkaline earth metal include calcium, strontium, barium and the like.

  Examples of basic boron compounds include sodium salts, potassium salts, lithium salts, calcium salts, magnesium salts, barium salts, strontium salts, and the like of boron compounds. Here, as the boron compound, for example, tetramethylboron, tetraethylboron, tetrapropylboron, tetrabutylboron, trimethylethylboron, trimethylbenzylboron, trimethylphenylboron, triethylmethylboron, triethylbenzylboron, triethylphenylboron, tributyl Examples include benzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, and butyltriphenylboron.

  Examples of the basic phosphorus compound include trivalent phosphine compounds such as triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, and tributylphosphine, or derivatives thereof. 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 hydroxide Sid, 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, 4-methoxypyridine, 2 -Dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like.

(Manufacturing process of polycarbonate resin)
Next, a specific manufacturing process of the polycarbonate resin to which the present embodiment is applied will be described.
In the polycarbonate resin production process, a raw material mixed melt of an aromatic dihydroxy compound and a carbonic acid diester compound as raw materials is prepared (original preparation process), and these compounds are melted in the presence of a transesterification reaction catalyst. It is carried out by carrying out polycondensation reaction in multiple stages using a reactor (polycondensation step). The reaction system may be any of a batch system, a continuous system, or a combination of a batch system and a continuous system. As the reactor, a plurality of vertical stirring reactors and, if necessary, at least one horizontal stirring reactor following this are used. Usually, these reactors are installed in series and processed continuously.
After the polycondensation process, the reaction is stopped, the unreacted raw materials and reaction byproducts in the polycondensation reaction liquid are devolatilized and removed, the process of adding a thermal stabilizer, mold release agent, colorant, etc., polycarbonate resin You may add suitably the process etc. which form in the pellet of a predetermined particle size.
Next, each process of the manufacturing method will be described.

(Primary process)
Aromatic dihydroxy compounds and carbonic acid diester compounds used as raw materials for polycarbonate resins are usually used in a batch, semi-batch or continuous stirring tank type apparatus in an atmosphere of an inert gas such as nitrogen or argon. It is prepared as a raw material mixed melt. For example, when bisphenol A is used as the aromatic dihydroxy compound and diphenyl carbonate is used as the carbonic acid diester compound, the melt mixing temperature is usually selected from the range of 20 ° C. to 180 ° C., preferably 125 ° C. to 160 ° C.
Hereinafter, a case where 2,2-bis (4-hydroxy-3-methylphenyl) propane is used as an aromatic dihydroxy compound and diphenyl carbonate is used as a raw material as a carbonic acid diester compound will be described as an example.
Under the present circumstances, the ratio of an aromatic dihydroxy compound and a carbonic acid diester compound is adjusted so that a carbonic acid diester compound may become excess, and a carbonic acid diester compound is 1.00 mol-1 normally with respect to 1 mol of aromatic dihydroxy compounds. .30 mol, preferably 1.01 mol to 1.20 mol.

(Polycondensation process)
The polycondensation by the transesterification reaction between the aromatic dihydroxy compound and the carbonic acid diester compound is usually carried out continuously in a multistage system having two or more stages. Specific reaction conditions for each tank are temperature: 150 ° C. to 320 ° C., pressure: normal pressure to 0.01 Torr (1.3 Pa), and average residence time: 5 minutes to 150 minutes.
In each multi-stage reactor, in order to more effectively remove aromatic monohydroxy compounds such as phenol as a by-product from the system as the polycondensation reaction proceeds, the temperature is increased stepwise in the above reaction conditions. Set to a higher vacuum. In order to prevent quality deterioration such as hue of the obtained polycarbonate resin, it is preferable to set a low temperature and a short residence time as much as possible.

When the polycondensation step is performed in a multistage manner, usually, a plurality of reactors including a vertical stirring reactor are provided to increase the average molecular weight of the polycarbonate resin. In the batch reaction, the reactor is usually installed in 2 to 4 groups, preferably 2 to 3 groups, and in the continuous system, usually 3 to 6 groups, preferably 4 to 5 groups.
Here, as a reactor, for example, a stirred tank reactor, a thin film reactor, a centrifugal thin film evaporation reactor, a surface renewal type biaxial kneading reactor, a biaxial horizontal type stirring reactor, a wet wall reactor, a free reactor A perforated plate reactor for polycondensation while dropping, a perforated plate reactor with wire for polycondensation while dropping along a wire, and the like are used.

  Examples of types of stirring blades for vertical stirring reactors include turbine blades, paddle blades, fiddler blades, anchor blades, full zone blades (manufactured by Shinko Pantech Co., Ltd.), Sun Meller blades (manufactured by Mitsubishi Heavy Industries, Ltd.), Max Blend Examples include wings (manufactured by Sumitomo Heavy Industries, Ltd.), helical ribbon wings, and twisted lattice wings (manufactured by Hitachi, Ltd.).

  Moreover, a horizontal stirring reactor means that the rotating shaft of a stirring blade is a horizontal type (horizontal direction). As a stirring blade of a horizontal stirring reactor, for example, a single-shaft stirring blade such as a disk type or a paddle type, HVR, SCR, N-SCR (manufactured by Mitsubishi Heavy Industries, Ltd.), Vivolac (manufactured by Sumitomo Heavy Industries, Ltd.) ), Or a biaxial stirring blade such as a spectacle blade or a lattice blade (manufactured by Hitachi, Ltd.).

In addition, the transesterification catalyst used for the polycondensation of the aromatic dihydroxy compound and the carbonic acid diester compound is usually prepared in advance as an aqueous solution. The concentration of the catalyst aqueous solution is not particularly limited, and is adjusted to an arbitrary concentration according to the solubility of the catalyst in water. Moreover, it can replace with water and other solvents, such as acetone, alcohol, toluene, and phenol, can also be selected.
The properties of water used for dissolving the catalyst are not particularly limited as long as the type and concentration of impurities contained are constant, but usually distilled water, deionized water, and the like are preferably used.

  Hereinafter, the present invention will be described more specifically based on examples. In addition, this invention is not limited to a following example. The physical properties of the polycarbonate resin used in the examples were evaluated by the following methods.

(1) Viscosity average molecular weight (Mv)
A methylene chloride solution (concentration (C) 0.6 g / dl) of a polycarbonate resin was prepared, and the specific viscosity (η _sp ) at a temperature of 20 ° C. of this solution was measured using an Ubbelohde viscometer. Average molecular weight (Mv) was calculated.
η _sp /C=[η](1+0.28η _sp)
[Η] = 1.23 × 10 ⁻⁴ Mv ^0.83

(2) Terminal hydroxyl group concentration ([OH])
Colorimetric determination was carried out by the titanium tetrachloride / acetic acid method (see, Macromol. Chem. 88, page 215 (1965)) to determine the terminal hydroxyl group concentration ([OH]).

(3) Pencil hardness Using an injection molding machine (J100SS-2, manufactured by Nippon Steel Co., Ltd.), a plate having a thickness of 3 mm, a length of 100 mm, and a width of 100 mm was injection molded under the conditions of a barrel temperature of 280 ° C. and a mold temperature of 90 ° C. . About this injection-molded plate, based on ISO15184, the pencil hardness measured by the 750g load was calculated | required using the pencil hardness tester (made by Toyo Seiki Co., Ltd.).

(4) Melt volume flow rate (MVR)
A melt volume flow rate per unit time at 300 ° C. under a load of 1.2 kg for a polycarbonate resin sample dried at 130 ° C. for 5 hours using a melt indexer (manufactured by Takara Industries Co., Ltd.) in accordance with ISO 1133 (MVR) was measured (unit: ^cm 3/10 min).

(5) Flow rate ratio (MVR-R)
Melt volume flow rate per unit time measured at 280 ° C. under a load of 21.6 kg for a polycarbonate resin sample dried at 130 ° C. for 5 hours in accordance with ISO 1133 using a melt indexer (Takara Industries Co., Ltd.) (MVR (280 ° C., 21.6 kg load)) and melt volume flow rate per unit time (MVR (280 ° C., 2.16 kg load)) measured at 280 ° C. and a load of 2.16 kg are measured similarly. did.
Using the measured values of the melt volume flow rate (MVR), the flow rate ratio (MVR-R) obtained by the following formula was calculated.
MVR-R = MVR (280 ° C., 21.6 kg load) / MVR (280 ° C., 2.16 kg load)

(6) Tensile elastic modulus Based on the results of a tensile test performed on a polycarbonate resin test piece prepared in accordance with ISO527-2 / 1A / 1 under conditions of 23 ° C. and a tensile speed of 1 mm / min, the tensile strength of the polycarbonate resin The elastic modulus was measured (unit: MPa).

(7) APHA color 2.5 g of polycarbonate resin was dissolved in 25 mL of methylene chloride, the solution was put into a cell having an optical path length of 5 cm, and absorbance (Abs) was measured at a wavelength of 420 nm using a spectrophotometer. Subsequently, APHA color was calculated | required from the following formula using the obtained light absorbency.
APHA = Abs × 645

(8) Analysis of ionic impurities contained in aromatic dihydroxy compound In a polypropylene container washed with ultrapure water, 0.2 g of aromatic dihydroxy compound is precisely weighed, and ionic impurities are removed in advance using ultrapure water. A toluene solution was prepared by dissolving in 50 mL of toluene. Next, 40 mL of ultrapure water was added to this toluene solution and shaken for 10 minutes using a shaker to extract ionic impurities in the aromatic dihydroxy compound to the water side. After shaking, the aqueous phase was removed by stationary separation. Subsequently, for this aqueous phase, an ion chromatograph (Ion Chromatograph DX-AQ manufactured by Nippon Dionex Co., Ltd.) equipped with a concentration module (Sample Concentration Module SPU-300 manufactured by Nippon Dionex Co., Ltd.) was used as the eluent. The anion component was measured with a mixture of 7 mM sodium carbonate and 0.3 mM sodium bicarbonate.

(9) Identification of structure of dihydro group compound represented by general formula (3) contained in aromatic dihydroxy compound High-speed chromatography in which mobile phase A is 0.05% aqueous trifluoroacetic acid and mobile phase B is methanol The dihydro group compound represented by the general formula (3) contained in the aromatic dihydroxy compound was separated at a wavelength of 280 nm. The mobile phase was initially set to 60% mobile phase A and 40% mobile phase B at a flow rate of 1 mL / min. Next, 25 minutes after the start of measurement, the ratio of mobile phase A and mobile phase B was gradually changed so that mobile phase B would be 95%. Furthermore, the mobile phase B was maintained at 95% from 25 minutes after the start of measurement until 40 minutes later.
Under the above analysis conditions, an absorption peak was observed in the vicinity of 13.9 minutes for the dihydro group compound represented by the general formula (3). The concentration was calculated based on a calibration curve prepared in advance using the injected aromatic dihydroxy compound.

(10) Identification of the composition of the polycarbonate copolymer 0.100 g of the polycarbonate resin was dissolved in 1 mL of deuterated chloroform, and using a nuclear magnetic resonance apparatus JNM-AL400 manufactured by JEOL Ltd., a resonance frequency of 400 MHz, an irradiation time of 4.1 sec, ¹ H-NMR measurement was performed at a relaxation time of 20 sec.
When the polycarbonate resin is a copolymer, the copolymer composition can be obtained as a molar composition based on the characteristic signal area intensity ratio depending on the dihydroxy compound used. For example, in the case of a copolymer of bisphenol A and 2,2-bis (3-methyl-4-hydroxyphenyl) propane (hereinafter referred to as “BPC”), the spectrum shown in FIG. 1 is obtained.
In FIG. 1, a methyl group bonded to the aromatic ring of BPC is observed around 2.25 ppm. Moreover, the signal of the methyl group of the isopropylidene group of bisphenol A and BPC is each observed at 1.6-1.7 ppm vicinity. Based on the area strength, the molar composition of the bisphenol A skeleton and the BPC skeleton in the polycarbonate resin is determined.
From the obtained molar composition and the formula amount of the repeating unit, the weight ratio of each skeleton was determined.

Example 1
An aqueous solution of cesium carbonate was added to 6,700 g of BPC (commercial BPC) and 5,765 g of diphenyl carbonate (hereinafter referred to as “DPC”) so as to be 1.5 μmol per 1 mol of BPC to prepare a mixture. Next, this mixture was charged into a first reactor having an internal temperature of 80 ° C. or less and an internal volume of 40 L and equipped with a stirrer, a heat medium jacket, a vacuum pump, and a reflux condenser.

  Next, the operation of setting the inside of the first reactor to 10 torr and then setting the atmosphere to atmospheric pressure with nitrogen was repeated five times to replace the inside of the first reactor with nitrogen. After nitrogen substitution, the internal temperature of the first reactor was gradually raised through a heat medium having a temperature of 230 ° C. in the heat medium jacket to dissolve the contents. Thereafter, stirring was performed at 300 rpm, the temperature in the heating medium jacket was controlled, and the internal temperature of the first reactor was kept at 220 ° C. The pressure in the first reactor was 101.3 kPa (760 Torr) in absolute pressure over 40 minutes while distilling off phenol produced as a by-product by the oligomerization reaction of BPC and DPC performed in the first reactor. To 13.3 kPa (100 torr).

  Subsequently, the pressure in the first reactor was maintained at 13.3 kPa, and an oligomerization reaction was performed for 80 minutes while further distilling off phenol. After completion of the oligomerization reaction, the inside of the system was restored to absolute pressure of 101.3 kPa with nitrogen, the gauge pressure was increased to 0.2 MPa, and the oligomerization reaction was performed using a transfer pipe heated to 200 ° C. or higher in advance. The obtained oligomer was pumped to a second reactor (internal pressure: atmospheric pressure) equipped with a stirrer having an internal volume of 40 L controlled to an internal temperature of 240 ° C., a heat medium jacket, a vacuum pump and a reflux condenser.

  Next, the oligomer fed into the second reactor was stirred at 38 rpm, the internal temperature was raised with a heat medium jacket, and the inside of the second reactor was absolute pressure from 101.3 kPa to 13.3 kPa over 40 minutes. The pressure was reduced to. Thereafter, the temperature increase was continued, and the internal pressure was reduced from 13.3 kPa to 399 Pa (3 Torr) as an absolute pressure over an additional 40 minutes, and the distilled phenol was removed out of the system. Further, the temperature was increased and the pressure was reduced. After the absolute pressure in the second reactor reached 70 Pa (about 0.5 torr), the pressure was maintained at 70 Pa, and a polycondensation reaction was performed. The final internal temperature in the second reactor was 285 ° C.

  In the present embodiment, the stirring power of the stirrer provided in the second reactor is used as an index of the molecular weight of the polycarbonate resin. The polycondensation reaction was completed when the stirrer of the second reactor had a predetermined predetermined stirring power. Next, the inside of the second reactor is restored to 101.3 kPa in absolute pressure with nitrogen, and the gauge pressure is increased to 0.2 MPa, and the polycarbonate resin is extracted in a strand form from the bottom of the second reactor, The mixture was pelletized by using a rotary cutter while being cooled at the same temperature.

  Subsequently, 15 ppm of butyl p-toluenesulfonate was added to the polycarbonate resin cut into pellets, melted and kneaded with a twin-screw extruder, and the molten polycarbonate resin was discharged from the outlet of the twin-screw extruder. While being extruded in a strand form and cooled in a water tank, it was pelletized with a rotary cutter.

  Viscosity average molecular weight (Mv), terminal hydroxyl group concentration ([OH]), pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile elastic modulus, APHA color of the obtained BPC homopolycarbonate resin The measurement results are shown in Table 1.

(Example 2)
Except that the setting of the molecular weight of the polycarbonate resin was changed, the same operation as in Example 1 was performed to obtain a polycarbonate resin. Measurement of viscosity average molecular weight (Mv), terminal hydroxyl group concentration ([OH]), pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile modulus, APHA color of the obtained polycarbonate resin The results are shown in Table 1.

(Example 3)
Cesium carbonate was added in an aqueous solution so as to be 2.0 μmol per 1 mol of BPC, the target molecular weight was made higher than that in Example 1, the addition amount of butyl p-toluenesulfonate was 20 ppm, and the others were the same as in Example 1. The operation was performed to obtain a polycarbonate resin. Measurement of viscosity average molecular weight (Mv), terminal hydroxyl group concentration ([OH]), pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile modulus, APHA color of the obtained polycarbonate resin The results are shown in Table 1.

Example 4
Commercially available BPC (commercially available BPC) was dissolved in acetone, and ultrapure water was added dropwise to obtain purified BPC of powder. Table 2 shows the content of the dihydroxy compound represented by the general formula (4) as a result of measuring ionic impurities of commercially available BPC and purified BPC.
Using this purified BPC, a polycarbonate resin was obtained under the same conditions as in Example 1. Measurement of viscosity average molecular weight (Mv), terminal hydroxyl group concentration ([OH]), pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile modulus, APHA color of the obtained polycarbonate resin The results are shown in Table 1.

(Example 5)
A polycarbonate resin was obtained under the same conditions as in Example 1 except that the purified BPC prepared in Example 4 was used as the raw material BPC and the set molecular weight of the polycarbonate resin was changed. Measurement of viscosity average molecular weight (Mv), terminal hydroxyl group concentration ([OH]), pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile modulus, APHA color of the obtained polycarbonate resin The results are shown in Table 1.

(Example 6)
Using the purified BPC prepared in Example 4 to the raw material BPC, cesium carbonate was added in an aqueous solution so as to be 2.0 μmol per 1 mol of BPC, the target molecular weight was made higher than that in Example 1, and the butyl p-toluenesulfonate was added. A polycarbonate resin was obtained under the same conditions as in Example 1 except that the addition amount was 20 ppm. Measurement results of viscosity average molecular weight (Mv), terminal hydroxyl group concentration ([OH]), pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile modulus, APHA color of the obtained polycarbonate Is shown in Table 1.

(Example 7)
A polycarbonate resin was obtained under the same conditions as in Example 1 except that the commercially available BPC comparative product 1 shown in Table 2 was used as the raw material BPC. Table 1 shows the physical properties of the obtained polycarbonate resin.

(Example 8)
A polycarbonate resin was obtained under the same conditions as in Example 1 except that the commercially available BPC comparative product 2 shown in Table 2 was used as the raw material BPC. Table 1 shows the physical properties of the obtained polycarbonate resin.

Example 9
A polycarbonate resin was obtained under the same conditions as in Example 1 except that the commercially available BPC comparative product 3 shown in Table 2 was used as the raw material BPC. Table 1 shows the physical properties of the obtained polycarbonate resin.

(Example 10)
A polycarbonate resin was obtained under the same conditions as in Example 1 except that 3350 g of bisphenol A (BPA) and 3350 g of BPC were used as the dihydroxy compound. The copolymer composition of the obtained polycarbonate resin was bisphenol A (BPA): BPC = 50: 50 (weight ratio) by ¹ H-NMR measurement, viscosity average molecular weight (Mv), terminal hydroxyl group concentration protein [OH]), Table 1 shows the measurement results of pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile modulus, and APHA color.

(Example 11)
A polycarbonate resin was obtained under the same conditions as in Example 1 except that 3350 g of bisphenol A (BPA) and 3350 g of tetramethylbisphenol A (TBPA) were used as the dihydroxy compound. The copolymer composition of the obtained polycarbonate resin was bisphenol A (BPA): tetramethylbisphenol A (TBPA) = 50: 50 (weight ratio) by ¹ H-NMR measurement, viscosity average molecular weight (Mv), terminal hydroxyl group concentration Table 1 shows the measurement results of ([OH]), pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile modulus, and APHA color.

(Example 12)
A polycarbonate resin was obtained under the same conditions as in Example 1 except that 6700 g of 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane was used as the dihydroxy compound. The obtained 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane is shown in Table 1.

From the results shown in Table 1, MVR and MVR of the polycarbonate resin obtained by polymerizing by using a compound in which an alkyl group is substituted on the aromatic ring as an aromatic dihydroxy compound by an ester exchange method as in Examples of the present application. By controlling -R (Examples 1 to 12), it becomes possible to obtain a polycarbonate resin having appropriate fluidity and melt tension and high surface hardness. The polycarbonate resin having such physical properties exhibits an effect of preventing dripping of the resin at the time of flame contact, and as a result, the flame retardancy of the resin is improved.
The amount of the dihydroxy compound represented by the general formula (3) contained in the dihydroxy compound is 5 ppm or less with respect to the amount of the raw material BPC, and chloride ion, nitrite ion, nitrate ion, phosphate ion When the aromatic dihydroxy compound having a total sulfate ion content of 10 ppm or less is used as a raw material (use of purified BPC: Examples 4, 5 and 6), the polycarbonate resin obtained is compared with the case where commercial BPC is used as the raw material. There is a tendency to improve the color tone.

(Comparative Example 1, Comparative Example 2)
BPC is used as a raw material, triethylamine is used as a catalyst, p-tert-butylphenol is used as a molecular weight regulator, interfacial polycondensation is performed using phosgene by a conventional method, and the amount of p-tert-butylphenol is adjusted to be different 2 A variety of polycarbonate resins were obtained. Table 3 shows the physical properties of the obtained polycarbonate resin.

(Comparative Example 3)
Physical properties of the polycarbonate resin (Novalex M7022IR manufactured by Mitsubishi Engineering Plastics Co., Ltd.) obtained using bisphenol A as a raw material were measured. The results are shown in Table 3.

(Comparative Example 4)
Physical properties of the polycarbonate resin (Novalex M7027BF manufactured by Mitsubishi Engineering Plastics Co., Ltd.) obtained using bisphenol A as a raw material were measured. The results are shown in Table 3.

(Comparative Example 5)
According to JP-A-64-069625, the following was carried out.
Weigh 6,700 g of BPC and 5,765 g of DPC, respectively, and add potassium borohydride as a catalyst so as to be 10 ⁻³ mol% with respect to BPC, with an internal temperature of 80 ° C. or less and an internal volume of 40 L. Yes, it was charged into a first reactor equipped with a stirrer, a heat medium jacket, a vacuum pump, and a reflux condenser.

  Subsequently, the operation of setting the inside of the first reactor to 10 torr and then setting it to atmospheric pressure with nitrogen was repeated 5 times to replace the inside of the first reactor with nitrogen. After nitrogen substitution, the internal temperature of the first reactor was gradually raised through a heat medium having a temperature of 230 ° C. through the heat medium jacket, and the contents were dissolved at 160 ° C. Then, it stirred for 30 minutes at 300 rpm, adjusting internal temperature to 160 degreeC. Next, under the same temperature, while the phenol produced as a by-product by the oligomerization reaction of BPC and DPC carried out in the first reactor is distilled off, the pressure in the first reactor is 101 in absolute pressure over 40 minutes. The pressure was reduced from 3 kPa (760 Torr) to 13.3 kPa (100 torr).

  Subsequently, the pressure in the first reactor is maintained at 13.3 kPa, and the mixture is stirred for 30 minutes while further distilling off phenol, and then the pressure in the first reactor is increased to 6.7 kPa (50 torr) in absolute pressure. The pressure was reduced and the mixture was stirred for 60 minutes while maintaining the temperature and pressure.

  Subsequently, the internal temperature was raised to 220 ° C. and reacted for 60 minutes to distill off by-produced phenol out of the system. After completion of the oligomerization reaction, the inside of the system was restored to absolute pressure of 101.3 kPa with nitrogen, the gauge pressure was increased to 0.2 MPa, and the oligomerization reaction was performed using a transfer pipe heated to 200 ° C. or higher in advance. The obtained oligomer was pumped to a second reactor (internal pressure: atmospheric pressure) equipped with a stirrer having an internal volume of 40 L controlled to an internal temperature of 220 ° C., a heat medium jacket, a vacuum pump and a reflux condenser.

  Next, the oligomer pumped into the second reactor was stirred at 38 rpm, and the internal temperature was maintained at 220 ° C. with a heating medium jacket, while the inside of the second reactor was increased from 101.3 kPa in absolute pressure over 40 minutes. The pressure was reduced to 13.3 kPa. Further, over 40 minutes, the internal pressure was reduced from 13.3 kPa to 1.33 kPa (10 Torr) in absolute pressure, and the reaction was performed for 30 minutes. Further, while maintaining the internal pressure, the internal temperature is gradually raised to 270 ° C., the reaction is carried out at 270 ° C. for 30 minutes, the pressure inside the system is then reduced to 665 Pa (5 Torr), the reaction is carried out for 30 minutes, and then distilled out. Phenol was almost completely removed from the system.

Finally, a polycondensation reaction was carried out at 270 ° C. and 13.3 Pa (0.1 Torr) to 39.9 Pa (0.3 Torr) for 2 hours to complete the reaction. Next, the inside of the second reactor is restored to 101.3 kPa in absolute pressure with nitrogen, and the gauge pressure is increased to 0.2 MPa, and the polycarbonate resin is extracted in a strand form from the bottom of the second reactor, The mixture was pelletized by using a rotary cutter while being cooled at the same temperature.
Viscosity average molecular weight (Mv), terminal hydroxyl group concentration ([OH]), pencil hardness, melt volume flow rate (MVR), flow rate ratio (MVR-R), tensile elastic modulus, APHA color of the obtained BPC homopolycarbonate resin Table 3 shows the measurement results.

From the results shown in Table 3, a polycarbonate resin obtained by the interfacial method (Comparative Examples 1 and 2), although the pencil hardness is at least H, MVR is less than ^{1 cm} 3/10 min, MVR-R is less than 18 It can be seen that the effect of improving flame retardancy cannot be expected.
It can be seen that the polycarbonate resin obtained by using bisphenol A as a raw material (Comparative Examples 3 and 4) has a pencil hardness of less than HB.
JP obtained according to the method described in 64-069625 discloses a polycarbonate resin (Comparative Example 5), although the pencil hardness is at least H, MVR exceeds 15cm ^3/10 minutes, MVR-R It can be seen that it is less than 18.

Claims (12)

A polycarbonate resin having a repeating unit represented by the following general formula (1) in the molecule and satisfying the following (a) to (c):

(In General Formula (1), R ₁ and R ₂ each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms or a substituted or unsubstituted aryl group, and R ₃ and R ₄ independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and X represents a single bond, substituted or unsubstituted. Represents an alkylene group, a substituted or unsubstituted alkylidene group, a substituted or unsubstituted sulfur atom, or an oxygen atom.)
(A) The pencil hardness according to ISO15184 is HB or higher.
(B) conforms to ISO 1133, 300 ° C., in the range melt volume flow rate (MVR) of ^{1 cm} 3/10 min ~15cm ^3/10 min at 1.2kg load.
(C) In accordance with ISO 1133, melt volume flow rate (MVR (280 ° C., 21.6 kg load)) at 280 ° C. and 21.6 kg load and melt volume flow rate (MVR (280) at 280 ° C. and 2.16 kg load) The flow rate ratio (MVR-R) obtained from the following formula is in the range of 18 to 45.
Flow rate ratio (MVR-R) = MVR (280 ° C., 21.6 kg load) / MVR (280 ° C., 2.16 kg load) The substituted or unsubstituted alkylidene group of X in the general formula (1) is

The polycarbonate resin according to claim 1, wherein
(R ₅ and R ₆ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group, and Z is substituted or unsubstituted. Represents an alkylene group having 4 to 20 carbon atoms.)   The polycarbonate resin according to claim 1 or 2, wherein an APHA color at a wavelength of 420 nm of a methylene chloride solution prepared to a concentration of 0.1 g / mL is 18 or less.   The polycarbonate resin according to any one of claims 1 to 3, which has a tensile modulus of elasticity of 1,800 MPa or more at 23 ° C and a tensile speed of 1 mm / min in accordance with ISO527-2 / 1A / 1. .   5. The polycarbonate resin according to claim 1, comprising 50% by weight or more of the repeating unit represented by the general formula (1). 6. The polycarbonate resin according to claim 1, wherein R ₃ and R ₄ in the general formula (1) are hydrogen atoms. It is obtained by polycondensation of a dihydroxy compound and a carbonyl compound, and the dihydroxy compound contains a dihydroxy compound represented by the following general formula (2). Polycarbonate resin.

(R ₁ , R ₂ and X in the general formula (2) have the same meanings as the general formula (1).) The dihydroxy compound further contains a dihydroxy compound represented by the following general formula (3), and the amount of the dihydroxy compound represented by the general formula (3) is that of the dihydroxy compound represented by the general formula (2). The polycarbonate resin according to claim 7, wherein the amount is 5 ppm or less.

(R ₁ , R ₂ and X in the general formula (3) have the same meaning as in the general formula (1), and R ₃ is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted group. Represents an unsubstituted aryl group.)   9. The total amount of chloride ion, nitrite ion, nitrate ion, phosphate ion and sulfate ion contained in the dihydroxy compound represented by the general formula (2) is 10 ppm or less. The polycarbonate resin described in 1.   The chloride ion contained in the dihydroxy compound represented by the general formula (2) is 1,000 ppb or less, the sum of nitrite ions and nitrate ions is 500 ppb or less, and the sum of phosphate ions and sulfate ions. The polycarbonate resin according to claim 9, wherein is not more than 200 ppb.   The polycarbonate resin according to any one of claims 7 to 10, wherein the carbonyl compound is a carbonic acid diester compound. A method for producing a polycarbonate resin according to any one of claims 1 to 11,
In the transesterification reaction of an aromatic dihydroxy compound and a carbonic acid diester performed in the presence of an alkali metal catalyst and / or an alkaline earth metal catalyst,
The method for producing a polycarbonate resin, wherein the amount of the alkali metal catalyst and / or the alkaline earth metal catalyst used is in the range of 0.1 to 5 μmol per mole of the aromatic dihydroxy compound.

Images