JPH07216062A - Production of polyester - Google Patents

Abstract

PURPOSE:To easily and safely obtain a polyester having excellent heat- resistance, hydrolysis resistance, cracking resistance, etc., and useful for lighting fixtures, etc., by reacting a specific dicarboxylic acid dialkyl ester with specific amounts of a diphenol and a dialkyl carbonate. CONSTITUTION:This polymer of formula I [Ar1 is a (a 1-20C hydrocarbon group or a halogen-substituted)6-20C aromatic hydrocarbon group, a 1-2C aliphatic hydrocarbon group or a 5-20C alicyclic hydrocarbon group; Ar2 is phenylene, naphthalene or group of formula II (X is single bond, O, S, a 1-20C alkylene, etc.; R1 to R8 each is H, a 1-8C hydrocarbon group or a halogen); (n) is 10-1,000] is produced by reacting (A) an aromatic, aliphatic or alicyclic dicarboxylic acid dialkyl ester with (B) 1-20 times mol (based on the component A) of a diphenol such as bisphenol A and (C) 2-400 times mol (based on the component B) of a dialkyl carbonate such as dimethyl carbonate in the presence of an esterification catalyst and a transesterification catalyst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester, and more particularly to a method for producing a polyester from an industrial product which is easily available by a transesterification method without using a solvent.

[0002]

Aromatic polycarbonate is an industrially useful engineering plastic as a heat-resistant transparent material. However, in recent years, there is a strong demand for heat resistance in the field of transparent materials, and the market for wholly aromatic polyester (polyarylate), which is a super engineering plastic with further improved heat resistance, is expanding. As a method for producing such a polyester, interfacial polycondensation in which dicarboxylic acid chloride is dissolved in an organic solvent and brought into contact with an alkaline aqueous solution of diphenols is generally used. This interfacial polycondensation can be carried out at a low temperature, a high molecular weight substance can be easily obtained, and the obtained polymer is also characterized by low coloring, but complicated operations are required for the synthesis and purification of the raw material phosgene and acid chloride. However, due to recent environmental problems, the use of halogen-based raw materials is not preferable, and there is a problem that a large amount of solvent is used.

Melt polycondensation is also known in which (1) diphenols and dicarboxylic acid diaryl esters or (2) diacetates of diphenols and dicarboxylic acids are polymerized in a molten state by the transesterification method. This melt polycondensation has a characteristic that it does not use a solvent and basically does not use a halogen, but it has a problem that a high molecular weight substance is difficult to obtain and the polymer obtained is colored because the reaction is carried out at a high temperature. Further, in (1), the dicarboxylic acid diaryl ester is expensive, and in (2), acetic acid produced as a by-product has a corrosive effect, so that the industrial value of these production methods is low.

[0004]

As described above, industrially useful means for producing polyester have not yet been known, and the development thereof has been desired. That is, the problem to be solved by the present invention is to provide a method for producing a polyester, which does not use a halogen-containing material and a solvent, makes the resulting polymer low-colored and has a sufficiently high molecular weight, and uses an inexpensive raw material. That is.

[0005]

The present inventors have arrived at the present invention as a result of extensive studies to solve these problems. That is, in the present invention, (A) aromatic, aliphatic or alicyclic dicarboxylic acid dialkyl ester, (B) diphenols, and (C) dialkyl carbonate are added in the presence of an esterification catalyst or a transesterification catalyst. When reacting, the component (A) is added to the stoichiometric amount of the component (B) in an amount of 1 to
A compound represented by the following general formula (I), characterized in that the component (C) is added in an amount of 20 times by mole, and the component (C) is added in an amount of 2 to 400 times by mole with respect to the stoichiometric amount of the component (B). The manufacturing method of the polyester is described.

[0006]

[Chemical 7]

[In the above formula (I), Ar ₁ has 6 to 2 carbon atoms.
0 aromatic hydrocarbon group (if necessary, each aromatic ring hydrogen atom may be independently substituted with a hydrocarbon group having 1 to 20 carbon atoms or a halogen group), aliphatic hydrocarbon having 1 to 20 carbon atoms It is a group selected from a hydrogen group or an alicyclic hydrocarbon group having 5 to 20 carbon atoms, and Ar ₂ is phenylene, naphthalene or a group represented by the following general formula (II). n is 10 to 1
It is an integer of 000.

[0008]

[Chemical 8]

In the above formula (II), X is a single bond, -O-,-.
S -, - SO -, - SO 2 -, - CO-, carbon atoms 1-2
0 alkylene group, alkylidene group or 4 to 20 carbon atoms
And R _{1 to} R ₈ are each independently a group selected from a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, and a halogen atom. ]

The feature of the present invention is that the aromatic, aliphatic or alicyclic dicarboxylic acid dialkyl ester as the component (A) is 1 to 20 times the stoichiometric amount of the diphenols as the component (B). It is added in a molar range, and the dialkyl carbonate as the component (C) is added in a range of 2 to 400 times the molar amount of the stoichiometric amount of the component (B). When the amount of the component (A) is less than the above range, the effect of improving the heat resistance of the obtained polymer becomes small, while even when it exceeds the above range, the effect of improving the heat resistance cannot be obtained for the added amount, On the contrary, it becomes uneconomical. On the other hand, if the amount of component (C) is less than the above range, the reaction rate becomes slower. On the other hand, if the amount of component (C) is more than the above range, the effect of increasing the reaction rate is not seen for the amount added, which is uneconomical.

The process for achieving the object of the present invention preferably comprises a three-step reaction process at different temperatures. That is, in the first step of the reaction, (A) aromatic, aliphatic or alicyclic dicarboxylic acid dialkyl ester, (B) diphenols, (C) dialkyl carbonate are mixed and the esterification or transesterification catalyst is present. Below 1
Heat to a temperature in the range of 00-250 ° C. A part of the alcohol and dialkyl carbonate produced by the reaction is distilled off. In the second stage, heating is performed at a temperature in the range of 200 to 300 ° C., and a part of the dialkyl carbonate produced by the transesterification reaction is further distilled off. In the third stage, the temperature was raised to 280-350 ° C and depressurized (0.0
The polyester is obtained by removing the remaining dialkyl carbonate under 5 to 50 Torr).

The aromatic, aliphatic or alicyclic dicarboxylic acid dialkyl ester as the component (A) used in the present invention is a compound represented by the following general formula (III).

[0013]

[Chemical 9]

[In the above formula (III), R ₉ is an alkyl group having 1 to 4 carbon atoms, Ar ₁ is an aromatic hydrocarbon group having 6 to 20 carbon atoms (if necessary, an aromatic ring hydrogen atom thereof). Are each independently substituted with a hydrocarbon group having 1 to 20 carbon atoms or a halogen group), an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an alicyclic hydrocarbon group having 5 to 20 carbon atoms. It is a group that is

Specific examples of such dicarboxylic acid dialkyl ester include terephthalic acid, isophthalic acid, phthalic acid, diphenyl ether-4,4'-dicarboxylic acid, benzophenone-4,4'-dicarboxylic acid and naphthalenedicarboxylic acid. Aromatic dicarboxylic acid, oxalic acid,
Aliphatic dicarboxylic acids such as malonic acid, succinic acid and glutaric acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,4-decahydronaphthalenedicarboxylic acid, 1 , 5-decahydronaphthalenedicarboxylic acid, 2,
Examples thereof include dimethyl ester, diethyl ester, dipropyl ester, and dibutyl ester of alicyclic dicarboxylic acid such as 6-decahydronaphthalenedicarboxylic acid and 2,7-decahydronaphthalenedicarboxylic acid, which may be used alone or in combination of two or more. Used. Among these, dimethyl terephthalate, dimethyl isophthalate, dimethyl 1,4-cyclohexanedicarboxylate, dimethyl 1,3-cyclohexanedicarboxylate, dimethyl 2,6-decahydronaphthalene dicarboxylate, and mixtures thereof are preferable.

The diphenols used as the component (B) in the present invention are compounds represented by the following general formula (IV).

[0017]

HO-Ar ₂ —OH (IV) [In the above formula (IV), Ar ₂ is phenylene, naphthalene or a group represented by the following general formula (II).

[0018]

[Chemical 11]

In the above formula (II), X is a single bond, -O-,-.
S -, - SO -, - SO 2 -, - CO-, carbon atoms 1-2
0 alkylene group, alkylidene group or 4 to 20 carbon atoms
And R _{1 to} R ₈ are each independently a group selected from a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, and a halogen atom. ]

Specific examples of such diphenols include 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), bis (4-hydroxyphenyl) methane and 1,1-bis (4-hydroxy). Phenyl)
-3,3,5-Trimethylcyclohexane (bisphenol TMC), bis (4-hydroxy-3,5-dimethylphenyl) methane, bis (4-hydroxy-3,5-)
Dichlorophenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexylmethane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4
-Hydroxyphenyl) -1-phenylethane, 4,
4'-dihydroxydiphenyl ether, bis (4-hydroxy-3,5-dimethylphenyl) ether, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxy-3,5-dimethylphenyl) sulfone, 4,
4'-dihydroxybenzophenone, 2,2-bis (4
-Hydroxy-3,5-dimethylphenyl) propane,
Tetrabromobisphenol A, tetrachlorobisphenol A, dihydroxydiphenyl, hydroquinone,
Resorcinol, dihydroxynaphthalene, dihydroxyanthracene, phenolphthalein, ferulescein, 2,2'-dihydroxy-1,1-dinaphthylmethane, 4,4'-dihydroxydinaphthyl and the like can be mentioned, and these can be used alone or in combination. The above is used in combination. Among these, bisphenol A, bisphenol T
MC and mixtures thereof are preferred.

The dialkyl dicarbonate as the component (C) used in the present invention is a compound represented by the following general formula (V).

[0022]

[Chemical 12]

[In the above formula (V), R ₁₀ and R ₁₁ have 1 carbon atoms.
To 4 alkyl groups, which may be the same or different. ]

Specific examples of such a dialkyl carbonate include dimethyl dicarbonate, diethyl dicarbonate, dipropyl dicarbonate, dibutyl dicarbonate, methyl ethyl carbonate, etc. These may be used alone or in combination of two or more. . Among these, dimethyl dicarbonate is preferable.

If necessary, a chain terminator and / or a branching agent may be used. The catalyst that can be used in the present invention is a catalyst generally known as an esterification catalyst or a transesterification catalyst, specifically, alkali metals such as lithium, sodium and potassium and salts thereof, alkaline earth such as magnesium, calcium and barium. Metals and their salts, zinc, cadmium, titanium, tin, antimony,
Acetates of metals such as lead, manganese, cobalt and nickel,
Carbonates, borates, oxides, hydroxides, hydrides, alcoholates and the like can be used in a proportion of 0.001 to 10% with respect to the stoichiometric amount of diphenols.

If necessary, antioxidants, ultraviolet absorbers, lubricants, plasticizers, dyes, pigments, flame retardants, fillers,
Reinforcing substances such as glass fibers, carbon fibers or other auxiliaries may be added. The amount to be added is appropriately determined according to the intended use. The polyesters according to the invention are used for the production of shaped articles, fibers, filaments and films. Since the polyester of the present invention has high heat resistance, strength (toughness), hydrolysis resistance, creep resistance, stress crack resistance, etc., fields requiring these physical properties, for example, the electric field, lighting field, In addition, it is particularly suitable for products in the automobile field and the like.

[0027]

The present invention will be described in more detail based on the following examples, but the present invention is not limited to the following examples, and various modifications can be made without departing from the scope of the invention. The properties of the polymer were measured according to the following methods. (1) Weight average molecular weight (Mw) of polymer Using a 510-type GPC system manufactured by Waters, column temperature 3 at a polymer concentration of 1 mg / ml in a chloroform solvent.
It was measured at 5 ° C. The weight average molecular weight was calculated using polystyrene as a standard sample. (2) Glass transition temperature (Tg) of polymer It was measured using a Perkin-Elmer DSC-7 differential scanning calorimeter under a nitrogen stream at a temperature rising rate of 20 ° C / min.

Example 1 22.8 g (0.1 mol) of bisphenol A, 18
0.2 g (2.0 mol) of dimethyl carbonate, 3
8.8 g (0.2 mol) of dimethyl terephthalate,
10 g (0.3 mmol) of Ti (OBu) ₄ was placed in a reaction vessel, and heating was started under a nitrogen atmosphere. Bath temperature 150 ℃
After stirring for 1 hour, the distillation of methanol and dimethyl carbonate was started. After the distillation of methanol was completed, the bath temperature was raised to 250 ° C., and dimethyl carbonate was further distilled. After 1 hour, the bath temperature was raised to 320 ° C., and stirring was continued under reduced pressure (0.2 mmHg) for 1 hour to completely distill off dimethyl carbonate. The polymer obtained had a molecular weight of 55,000 and a glass transition temperature of 215 ° C.

Example 2 22.8 g (0.1 mol) of bisphenol A, 18
0.2 g (2.0 mol) of dimethyl carbonate, 1
9.6 g (0.1 mol) of dimethyl terephthalate, 1
9.6 g (0.1 mol) of dimethyl isophthalate,
10 g (0.3 mmol) of Ti (OBu) ₄ was placed in a reaction vessel, and heating was started under a nitrogen atmosphere. Bath temperature 150 ℃
After stirring for 1 hour, the distillation of methanol and dimethyl carbonate was started. After the distillation of methanol was completed, the bath temperature was raised to 250 ° C., and dimethyl carbonate was further distilled. After 1 hour, the bath temperature was raised to 320 ° C., and stirring was continued for 1 hour under reduced pressure (0.1 mmHg) to completely distill off dimethyl carbonate. The polymer obtained had a molecular weight of 59000 and a glass transition temperature of 197 ° C.

Example 3 22.8 g (0.1 mol) of bisphenol A, 18
0.2 g (2.0 mol) of dimethyl carbonate, 4
0.0 g (0.2 mol) dimethyl 1,4-cyclohexanedicarboxylate, 0.10 g (0.3 mmol) Ti
(OBu) ₄ was placed in a reaction vessel, and heating was started under a nitrogen atmosphere. After stirring at a bath temperature of 150 ° C. for 1 hour, distillation of methanol and dimethyl carbonate was started. After the distillation of methanol was completed, raise the bath temperature to 250 ° C,
Further, dimethyl carbonate was distilled off. After 1 hour, the bath temperature was raised to 320 ° C and the pressure was reduced (0.2 mmHg) to 1
The stirring was continued for an hour to completely distill off dimethyl carbonate. The polymer obtained had a molecular weight of 58,000 and a glass transition temperature of 180 ° C.

Example 4 22.8 g (0.1 mol) of bisphenol A, 18
0.2 g (2.0 mol) of dimethyl carbonate, 1
9.6 g (0.1 mol) of dimethyl terephthalate, 2
5.6 g (0.1 mol) of dimethyl 2,6-decahydronaphthalenedicarboxylate and 0.10 g (0.3 mmol) of Ti (OBu) ₄ were placed in a reaction vessel and heating was started under a nitrogen atmosphere. After stirring at a bath temperature of 150 ° C. for 1 hour, distillation of methanol and dimethyl carbonate was started. After the distillation of methanol was completed, the bath temperature was raised to 250 ° C., and dimethyl carbonate was further distilled. After 1 hour, raise the bath temperature to 320 ° C and reduce the pressure (0.1 mmHg)
Under stirring, the mixture was continuously stirred for 1 hour to completely distill off dimethyl carbonate. The obtained polymer has a molecular weight of 53,000,
The glass transition temperature was 205 ° C.

Example 5 22.8 g (0.1 mol) of bisphenol A, 18
0.2 g (2.0 mol) of dimethyl carbonate, 1
9.6 g (0.1 mol) of dimethyl terephthalate, 1
9.6 g (0.1 mol) of dimethyl isophthalate,
10 g (0.3 mmol) of Ti (OBu) ₄ was placed in a reaction vessel, and heating was started under a nitrogen atmosphere. Bath temperature 320 ℃
After stirring for 1 hour, the distillation of methanol and dimethyl carbonate was started. After 1 hour, the pressure was reduced (0.1 mmHg), and stirring was continued for 1 hour to distill dimethyl carbonate completely. The molecular weight of the obtained polymer is 4600.
0, the glass transition temperature was 192 ° C.

Comparative Example 1 440.9 g (1.93 mol) of bisphenol A, 1
3.4 g (0.09 mol) of pt-butylphenol, 1027 ml of 5N aqueous sodium hydroxide solution and 4
103 ml of water was mixed in a 5 L flask in a nitrogen atmosphere and then cooled to 5 ° C. to prepare an alkaline aqueous solution.
On the other hand, in another 5 L flask, 201.1 g (0.99
mol) terephthalic acid chloride, and 201.1 g
(0.99 mol) of isophthalic acid chloride was dissolved in 5000 ml of methylene chloride in a nitrogen atmosphere and cooled to 5 ° C. Then, in another 15 L separable flask, 2000 ml of water and 6.7 as phase transfer catalyst.
5 g (0.03 mol) of benzyltriethylammonium chloride was charged under a nitrogen atmosphere and cooled to 5 ° C. While vigorously stirring the cooling liquid, the above-mentioned two liquids prepared in advance were simultaneously added continuously for 15 minutes by using a pump. When the stirring was stopped 3 hours after the addition was completed, the mixture was separated into a methylene chloride phase and an aqueous phase. After decanting the aqueous phase, the same amount of water was added and neutralized with a small amount of hydrochloric acid while stirring. Further, after desalting by washing with water repeatedly, the same amount of acetone was gradually added to the methylene chloride phase to precipitate a polymer powder, which was collected by filtration.
The polymer obtained had a molecular weight of 64000 and a glass transition temperature of 199 ° C.

[0034]

As described above, according to the present invention, a polyester having excellent heat resistance can be produced by a simple and inexpensive method without using harmful halides such as phosgene, acid chloride and methylene chloride. .

Claims (9)

[Claims] 1. A (A) aromatic, aliphatic or alicyclic dicarboxylic acid dialkyl ester, (B) diphenol, and (C) dialkyl carbonate are reacted in the presence of an esterification catalyst or a transesterification catalyst. On the occasion of
1 to 20 of the component (A) relative to the stoichiometric amount of the component (B)
It is represented by the following general formula (I), characterized in that the component (C) is added in an amount of 2 to 400 times the stoichiometric amount of the component (B). Method for producing polyester. [Chemical 1] [In the above formula (I), Ar ₁ is an aromatic hydrocarbon group having 6 to 20 carbon atoms (if necessary, the hydrogen atoms of the aromatic ring are each independently a hydrocarbon group having 1 to 20 carbon atoms or a halogen group). May be substituted), a group selected from an aliphatic hydrocarbon group having 1 to 20 carbon atoms or an alicyclic hydrocarbon group having 5 to 20 carbon atoms, Ar ₂ is phenylene, naphthalene or the following general formula (II ) Is a group represented by. n is an integer of 10 to 1000. [Chemical 2] In the above formula (II), X is a single bond, -O-, -S-, -SO.
—, —SO ₂ —, —CO—, an alkylene group having 1 to 20 carbon atoms, an alkylidene group, or a cycloalkylidene group having 4 to 20 carbon atoms, and R _{1 to} R ₈ each independently represent a hydrogen atom or 1 carbon atom. It is a group selected from a hydrocarbon group of 10 to a halogen atom. ] 2. A three-step reaction process comprising a first step at 100 to 250 ° C. and a second step at 200 to 300 ° C.
The method according to claim 1, wherein the third step is performed at 280 to 350 ° C. 3. The production method according to claim 1, wherein the component (A) is represented by the following general formula (III). [Chemical 3] [In the above formula (III), R ₉ is an alkyl group having 1 to 4 carbon atoms, Ar ₁ is an aromatic hydrocarbon group having 6 to 20 carbon atoms (if necessary, the aromatic ring hydrogen atoms are independently May be substituted with a hydrocarbon group having 1 to 20 carbon atoms, a halogen group), an aliphatic hydrocarbon group having 1 to 20 carbon atoms or 5 carbon atoms.
To 20 alicyclic hydrocarbon groups. ] 4. The component (A) is an isophthalic acid derivative, a terephthalic acid derivative, a 1,4-cyclohexanedicarboxylic acid derivative, a 1,3-cyclohexanedicarboxylic acid derivative,
1,4-decahydronaphthalenedicarboxylic acid derivative,
1,5-decahydronaphthalenedicarboxylic acid derivative,
The production method according to claim 3, which is at least one selected from a 2,6-decahydronaphthalenedicarboxylic acid derivative and a 2,7-decahydronaphthalenedicarboxylic acid derivative. 5. The method according to claim 1, wherein the component (B) is represented by the following general formula (IV). Embedded image HO-Ar ₂ -OH (IV) [the formula (IV), Ar ₂ is a group represented by phenylene, naphthalene or the following general formula (II). [Chemical 5] In the above formula (II), X is a single bond, -O-, -S-, -SO.
—, —SO ₂ —, —CO—, an alkylene group having 1 to 20 carbon atoms, an alkylidene group, or a cycloalkylidene group having 4 to 20 carbon atoms, and R _{1 to} R ₈ each independently represent a hydrogen atom or 1 carbon atom. It is a group selected from a hydrocarbon group of 10 to a halogen atom. ] 6. The component (B) is bisphenol A [2,2].
-Bis (4-hydroxyphenyl) propane] and / or 1,1-bis (4-hydroxyphenyl) -3,3
The production method according to claim 5, which is 5-trimethylcyclohexane. 7. The method according to claim 1, wherein the component (C) is a dialkyl carbonate represented by the following general formula (V). [Chemical 6] [In the formula (V), R ₁₀ and R ₁₁ are alkyl groups having 1 to 4 carbon atoms and may be the same or different. ] 8. The production method according to claim 7, wherein the component (C) is dimethyl carbonate. 9. The production method according to claim 1, wherein the esterification catalyst or the transesterification catalyst is present in a proportion of 0.001 to 10% with respect to the stoichiometric amount of the component (B).