JP3102927B2 - Linear polycarbonate and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a linear polycarbonate.
It relates DOO, more particularly, colorization, no branched structure formed by side reactions during the polymerization linear polycarbonate
About the over door.

[0002]

2. Description of the Related Art Polycarbonate is prepared by an interfacial polycondensation method (phosgene) in which a solvent such as methylene chloride is added to an aqueous solution or suspension of a sodium salt of dihydric phenol, and phosgene is blown into the solution. Method) or an ester exchange method in which a dihydric phenol and a carbonic acid diester such as diphenyl carbonate are heated and melted, and polycondensed by a transesterification reaction under reduced pressure at high temperature. In the production method of these polycarbonates,
Generally, the interfacial polycondensation method is widely used. However, this method not only requires the use of extremely toxic phosgene, but also leaves chloride ions in the produced polycarbonate. If chlorine ions remain in the polycarbonate as described above, the polymer is colored by molding at a high temperature. Therefore, it is necessary to wash the obtained polymer in order to reduce the residual chloride ion concentration.

[0003] On the other hand, the transesterification method has such advantages that no highly toxic phosgene is required and that there is no need to provide a step for removing residual chloride ions. The transesterification process generally requires a catalyst, and a number of compounds have been proposed to be effective in producing polycarbonate. However, in the transesterification method, unlike the interfacial polycondensation method, it is generally difficult to obtain a high molecular weight polycarbonate, and the polymer is colored because the reaction is carried out in the presence of a catalyst and under high temperature and reduced pressure. For example, JP-A-60-51719 proposes a method for producing polycarbonate by using a catalyst comprising a combination of a nitrogen-containing basic compound and a boron compound. This catalyst has low activity,
There was a problem that it was difficult to obtain a high molecular weight product.

Alkali metal compounds and alkaline earth metal compounds are well known as highly active catalysts effective for the production of polycarbonate by the transesterification method. However, it is known that these compounds cause a side reaction to form a branched structure by a Kolbe-Schmidt type reaction or a branched structure through formation of isoalkenylphenol [Encyclopedia of Polymer Science and Technology]. ｛Encyclopedia of Polymer
Science and Technology, 10 , 722 (1969)｝]. Therefore,
When an attempt is made to obtain a high molecular weight polycarbonate, a branched structure is formed by a side reaction, and depending on the reaction conditions, it becomes partially insoluble in a solvent such as methylene chloride or is excessively colored. Accordingly, an object of the present invention is to produce a high-molecular-weight linear polycarbonate that is free of coloring, does not contain chloride ions that cause coloring, and does not have a branched structure generated by a side reaction.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, in the production of polycarbonate by the transesterification method, the use of a catalyst comprising a combination of specific compounds has been considered. It has been found that a high-molecular-weight polycarbonate which is hardly colored and substantially does not contain a chloride ion and a branched structure which causes coloring is obtained, thereby completing the present invention. That is, the present invention relates to a linear polycarbonate produced from a dihydric phenol and a carbonic acid diester by a transesterification method, wherein the catalyst comprises a nitrogen-containing basic compound, a group IIb of the periodic table of elements, Produced by using at least one compound containing an element selected from the group of the IVb group and the Vb group, and the branching parameter G = [η] /
[Η] _lin (where [η] is the intrinsic viscosity in methylene chloride at 20 ° C., and [η] _lin is the same as the linear polycarbonate having the same weight average molecular weight measured by the light scattering method at 20 ° C. in methylene chloride. Is 0.8-1.
0, substantially having a weight average molecular weight of 34,500 or more.
Provide a linear polycarbonate .

The linear polycarbonate of the present invention has a branching parameter G of 0.8 to 1.0 , preferably 0.88.
To 1.0, more preferably 0.91 to 1.0 . Here, the branch parameter G is a ratio of the intrinsic viscosity [η] of the produced polycarbonate to the intrinsic viscosity [η] _lin of the linear polycarbonate having the same weight average molecular weight, that is, G =
It is defined by [η] / [η] _lin . [Η] _lin , when the dihydric phenol is bisphenol A, Schulz (S
chultz) based on the viscosity formula [η] = 1.11 × 10 ⁻⁴ Mw ^0.82 (Mw indicates a weight average molecular weight), and the molecular weight distribution is Schultz-Zi
It was calculated as following an exponential distribution of mm. In the case of copolymers and homopolymers using other dihydric phenols, the viscosity formula is determined from the limiting viscosity and the weight average molecular weight of the linear polycarbonate produced by the interfacial polycondensation method, and The branching parameter G was calculated in the same manner as described above. In addition, heavy
The weight average molecular weight (Mw) is calculated using a general-purpose calibration curve in addition to the light scattering method.
GPC method is also possible.
It was within the error. Considering that polycarbonate having a branching parameter G of more than 0.8 behaves as a Newtonian fluid in the molten state, and taking into account the measurement error when measuring the weight average molecular weight, the measurement error when measuring the intrinsic viscosity, and the influence of the molecular weight distribution, etc. It is concluded that it does not have a substantially branched structure. Polycarbonate having a branching parameter G of less than 0.8 has a measurement error in measuring the weight average molecular weight,
It is concluded that the resin has a branched structure even when considering the measurement error and the influence of the molecular weight distribution when measuring the intrinsic viscosity.
That is, in this case, a branched structure is formed by a side reaction during the polymerization, and a structure different from the original structure of the polycarbonate is formed.

The linear polycarbonate of the present invention has a hydroxyl group terminal of 20 mol% or less of all terminals. When the hydroxyl group terminal is more than 20 mol% , it tends to be colored at the time of molding at a high temperature and the molecular weight is liable to decrease. The alkali metal ion concentration and alkaline earth metal ion concentration in the linear polycarbonate of the present invention are 1 ppm or less and the chloride ion concentration is 10 ppm or less. When the alkali metal ion concentration and the alkaline earth metal ion concentration exceed 1 ppm, formation of a branched structure and coloring due to side reactions become remarkable. If the chloride ion concentration exceeds 10 ppm, coloring during molding processing becomes remarkable.

As a method for producing a linear polycarbonate as described above, the method of the present invention described above is effective. That is, a dihydric phenol and a carbonic acid diester are mixed, and a nitrogen-containing basic compound and a group IIb, IVb
It is produced by a melt transesterification method by using at least one compound containing an element selected from the group consisting of group Vb and group Vb.

As the dihydric phenol used in the present invention, bisphenol A (2,2-bis (4-hydroxyphenyl) propane is widely used.
-Hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 2 , 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 4,4'-dihydroxy-2,2,2-triphenylethane, 2,2-bis (3-bromo-4 -Hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 1,1-bis (
4-hydroxy-3-methylphenyl) propane, 2,2
-Bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3-isopropylphenyl) propane, 2,2-bis (4-hydroxy-3-
Sec.butylphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-t-butylphenyl) propane, 1,1-bis Bis (hydroxyaryl) alkanes such as (4-hydroxy-3-tert-butylphenyl) propane; 1,1-bis (4-hydroxyphenyl) -p-
Diisopropylbenzene, 1,1'-bis (4-hydroxyphenyl) -p-diethylbenzene, 1,1-bis (4-
Bis (hydroxyaryl) arenes such as (hydroxyphenyl) -m-diisopropylbenzene, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-
Bis (hydroxyaryl) cycloalkanes such as bis (4-hydroxyphenyl) cyclooctane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-
Dihydroxy diaryl ethers such as 3,3'-dimethyl diphenyl ether; 4,4'-dihydroxy diphenyl sulfide; dihydroxy diaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfide; 4,4'- Dihydroxydiphenylsulfoxide, 4,4 '
Dihydroxydiarylsulfoxides such as dihydroxy-3,3'-dimethyldiphenylsulfoxide, 4,4'-
Dihydroxydiaryl sulfones such as dihydroxydiphenyl sulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfone can be used. These dihydric phenols can be used alone or in combination of two or more.

Examples of the carbonic diester used in the present invention include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, dicyclohexyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate and the like. Can be used. Among these carbonic acid diesters, diphenyl carbonate is widely used. These carbonic acid diesters can be used alone or in combination of two or more. The amount of carbonic acid diester used is usually 0.90 to 1.50 per mole of dihydric phenol.
Mole, preferably 0.95 to 1.25 mole.

If necessary, a dicarboxylic acid or a dicarboxylic acid ester may be used instead of a part of the carbonic acid diester. In this case, a polyester carbonate is obtained. As dicarboxylic acids and dicarboxylic esters,
For example, terephthalic acid, diphenyl terephthalate, isophthalic acid, diphenyl isophthalate and the like can be mentioned. The amount of the dicarboxylic acid and dicarboxylic acid ester used is, for example, 50 mol% or less, preferably 30 mol% or less of the carbonic acid diester.

The type of the amine compound which is a nitrogen-containing basic compound used in the present invention is not particularly limited as long as it has an electron donating property. Examples of the electron-donating amine compound include pyridine, 4-aminopyridine, 2-aminopyridine, 4-dimethylaminopyridine, 4-diethylaminopyridine, 4-pyrrolidinopyridine, 2-hydroxypyridine, 4-hydroxypyridine, and 2-hydroxypyridine. Methoxypyridine, 4-methoxypyridine, picoline, pyrimidine, imidazole, 2-methylimidazole, 4-methylimidazole, 2-dimethylaminoimidazole,
2-methoxyimidazole, 2-mercaptoimidazole, pyrazole, aminoquinoline, benzimidazole, N, N-dimethylaniline, pyrrolidine, morpholine, N-methylmorpholine, piperidine, piperazine,
1,4-diazabicyclo [2.2.2] octane (DABCO),
1,8-diazabicyclo [5.4.0] -7-undecene (DBU)
, 1,5-diazabicyclo [4.3.0] -5-nonene (DBN)
And the like. These electron donating amine compounds can be used alone or in combination of two or more.

The compound constituting the catalyst system together with the electron-donating amine compound described above is a compound containing an element selected from the group IIb, IVb and Vb groups of the periodic table. The compound containing these elements may be an organic or inorganic compound. Elements belonging to Group IIb of the Periodic Table of the Elements include zinc, cadmium and the like. Preferred IIb
Group elements include zinc and cadmium. As the zinc compound, for example, zinc acetate, zinc oxalate, zinc phenylacetate, zinc chloride, zinc sulfate, zinc nitrate, zinc carbonate, zinc oxide, zinc hydroxide, zinc stearate, zinc-
Chromium oxide, zinc-chromium-copper oxide and the like can be mentioned. Examples of the cadmium compound include cadmium acetate, cadmium oxalate, cadmium oxide, and cadmium stearate.

Elements belonging to Group IVb include silicon, germanium, tin and lead. Preferred Group IVb elements include copper and lead. Examples of the silicon compound include silicon oxide, silicon-aluminum oxide (SiO ₂ —Al ₂ O ₃ ), silicon-magnesium oxide (SiO ₂ —
MgO) and the like, and examples of the germanium compound include germanium oxide and germanium hydroxide. As the tin compound, an organic or inorganic compound containing tin, such as stannous acetate, stannous oxalate, tin octylate, stannous chloride, stannic chloride, stannous oxide, stannic oxide, tetra Phenyltin and the like. Representative examples of the lead compound include, for example, lead acetate, lead borate, lead citrate, lead hydroxide, lead oxide, lead phosphate, lead phthalate, lead stearate and the like.

Elements belonging to the Vb group include antimony and bismuth. As antimony compounds,
Examples include antimony acetate, antimony oxalate, triphenylantimony, antimony trioxide, antimony pentoxide, triphenoxyantimony, trimethoxyantimony, triethoxyantimony, antimony trichloride and the like. Examples of the bismuth compound include organic or inorganic compounds containing bismuth, such as bismuth acetate, bismuth oxalate, triphenylbismuth, bismuth trioxide, and bismuth trichloride.

In the method of the present invention, the nitrogen-containing basic compound is combined with one or more compounds containing an element selected from the group consisting of groups IIb, IVb and Vb of the periodic table. A catalyst system is constituted, and a dihydric phenol is subjected to a melt polycondensation reaction with a carbonic acid diester. Compounds containing an element selected from the group of the periodic table of elements IIb group, IVb group and Vb group may constitute a catalyst system in combination with the nitrogen-containing basic compound alone, and may be the same or different. A catalyst system may be constituted by combining a plurality of compounds containing an element and the nitrogen-containing basic compound.

[0017] The amount of the nitrogen-containing basic compound may be in a range not impaired polycondensation reaction, for example, ^10-7 to ^10-1 mol relative to the dihydric phenol, preferably 10 ^-6 to 10 ^{- 2} moles. If the amount of the electron-donating amine compound is less than 10 ^-7 mol, the desired degree of polymerization, for example, the weight average molecular weight is about
In order to reach 5,000 to 50,000, it is necessary to react for a long time at a high temperature of 220 to 300 ° C., which is not effective as an industrial production method of polycarbonate. On the other hand, when the amount exceeds 10 ^-1 mol, the amount of the catalyst remaining in the produced polycarbonate increases, so that the physical properties of the polycarbonate tend to be deteriorated.

Further, the periodic table of elements, groups IIb, IVb and
The amount of the compound containing an element selected from the group of Vb group is
For example, it is 10 ^-8 to 10 ^-2 mol, preferably 10 ^-7 to 10 ^-3 mol, based on dihydric phenol. The amount of these compounds used
If the amount is less than 10 ^-8 mol, it takes a long time to obtain a polycarbonate having a desired degree of polymerization, which is not effective as an industrial production method of polycarbonate. On the other hand, if it exceeds 10 ^-2 mol, the amount of the catalyst remaining in the produced polycarbonate increases, so that the physical properties of the polycarbonate are liable to deteriorate.

The transesterification reaction is carried out by a conventional method employed in a melt polycondensation reaction, for example, a reaction is carried out at an initial temperature of 80 to 250 ° C., preferably about 100 to 230 ° C., and then the temperature is raised while reducing the pressure. More specifically, the reaction can be performed at about 250 to 320 ° C. The degree of pressure reduction at the end of the reaction is preferably, for example, 0.3 Torr or less. In such a transesterification reaction, a polycondensation reaction proceeds smoothly, and a high-molecular-weight polycarbonate having no coloring and substantially containing no chloride ion and a branched structure is obtained.

[0020]

According to the method of the present invention, the transesterification between dihydric phenol and carbonic acid diester is carried out in the presence of a specific catalyst. A linear polycarbonate with a molecular weight is obtained.

[0021]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Example 1 A flask having an internal volume of 300 ml was charged with 45.66 g (0.20 mol) of 2,2-bis (4-hydroxyphenyl) propane and 42.99 g (0.21 mol) of diphenyl carbonate.
Dimethylaminopyridine 1.2 × 10 ^-3 g (1 × 10 ^-5 mol)
After adding 6.0 × 10 ⁻⁴ g (2 × 10 ⁻⁶ mol) of antimony acetate, the inside of the flask was replaced with nitrogen and heated to 160 ° C. The mixture was stirred at 160 ° C. and normal pressure for 30 minutes after the raw materials were melted, and then the pressure inside the system was gradually reduced to 5 Torr while gradually raising the temperature to 240 ° C., thereby distilling out about 32 ml of phenol. Then, the temperature was raised and reduced to 270 ° C and 0.2 Torr, and finally
A polycondensation reaction was conducted at 0.2 ° C. and 0.2 Torr for 1.5 hours to obtain a colorless and transparent polycarbonate.

Examples 2 to 5 The same operation as in Example 1 was carried out except that the catalyst was changed as follows, to obtain a colorless and transparent polycarbonate. That is,
In Example 2, 4-dimethylaminopyridine 1.2 × 10 ⁻³ g
(1 × 10 ⁻⁵ mol) and stannous acetate 4.7 × 10 ⁻⁴ g (2 × 10 ⁻⁵ mol)
^-6 mol), and in Example 3, 4-dimethylaminopyridine
1.2 × 10 ^-3 g (1 × 10 ^-5 mol) and 7.6 × 10 ^-4 g lead acetate
(2 × 10 ⁻⁶ mol). In Example 4, 1.2 × 10 ⁻³ g (1 × 10 ⁻⁵ mol) of 4-dimethylaminopyridine and zinc acetate 4.4
× 10 ⁻⁴ g (2 × 10 ⁻⁶ mol), and in Example 5, 1.2 × 10 ⁻³ g (1 × 10 ⁻⁵ mol) of 4-dimethylaminopyridine and 1.17 × 10 ⁻⁴ g (4 × 10 ⁻⁴ mol) of antimony trioxide 10 ^-6 mol) was used as catalyst.

Comparative Examples 1 to 3 Polycarbonate was obtained in the same manner as in Example 1 except that the catalyst was changed as follows. That is, in Comparative Example 1, 4.0 × 10 ⁻⁴ g (4 × 10 ⁻⁶ mol) of potassium acetate, and in Comparative Example 2, 4 × 10 ⁻⁴ g of potassium acetate.
Dimethylaminopyridine 1.2 × 10 ^-3 g (1 × 10 ^-5 mol) and lithium acetate 2.6 × 10 ^-4 g (4 × 10 ^-6 mol),
In Comparative Example 3, 4-dimethylaminopyridine 1.2 × 10 ⁻³ g
(1 × 10 ⁻⁵ mol) and 2.8 × 10 ⁻⁴ g of potassium carbonate (2 ×
10 ^-6 mol) was used as catalyst. Intrinsic viscosity, weight average molecular weight, branching parameter G value, molecular weight distribution Mw / Mn (weight average) determined by gel permeation chromatography for all polycarbonates obtained in Examples 1 to 5 and Comparative Examples 1 to 3. Molecular weight /
Table 1 shows the number average molecular weight, the alkali metal ion concentration and the alkaline earth metal ion concentration [M ⁺ ], and the hue.

[0024]

[Table 1]

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-163131 (JP, A) JP-A-3-26722 (JP, A) JP-A-3-174443 (JP, A) Mikio Matsugane, Shogo Tahara , Kato Shuji, "Plastic Materials Course 5 Polycarbonate Resin", Nikkan Kogyo Shimbun, September 30, 1969, p. 64, p. 78 (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 64/00-64/42

Claims (4)

(57) [Claims] 1. A branching parameter G = [η] / [η]
_lin (where [η] is the intrinsic viscosity at 20 ° C in methylene chloride, and [η] _lin is the intrinsic viscosity at 20 ° C in methylene chloride of a linear polycarbonate having the same weight average molecular weight measured by a light scattering method. in it.) nitrous at 0.8 to 1.0
And a linear polycarbonate having a weight average molecular weight of 34,500 or more . 2. A linear polycarbonate having a branching parameter G of 0.8 to 1.0, a hydroxyl group terminal of 20 mol% or less, and a weight average molecular weight of 34,500 or more among all terminals of the polycarbonate. 3. The branching parameter G is 0.8 to 1.0, the alkali metal ion concentration and alkaline earth metal ion concentration in the polycarbonate are 1 ppm or less, the chloride ion concentration is 10 ppm or less, and the weight average molecular weight is 34500.
The above-mentioned linear polycarbonate. Claim 4. A is prepared by melt transesterification process from a dihydric phenol and a carbonic acid diester 1,2 addition
Is a linear polycarbonate according to 3 .