JPS6029732B2 - Method for manufacturing aromatic polyester - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for producing aromatic polyester.

More specifically, the present invention relates to an improved method for producing an aromatic polyester having excellent heat resistance, transparency, and chemical resistance. Polyethylene terephthalate is widely used industrially due to its excellent mechanical properties and chemical resistance, but its heat distortion temperature (
It has the drawbacks of relatively low heat resistance) and high crystallization rate, resulting in poor dimensional stability and transparency.

Conventionally, as a method for improving such drawbacks, a method has been attempted in which an aromatic dicarboxylic acid converter and an aromatic dihydroxy compound undergo a polycondensation reaction.

For example, {a-method in which an aromatic dicarboxylic acid chloride and an aromatic dihydroxy compound are reacted in a solution, 'b-method in which a diarylester of an aromatic dicarboxylic acid and an aromatic dihydroxy compound are melt-polymerized, [c' A method of reacting an aromatic dicarboxylic acid, an aromatic dihydroxy compound, and a diaryl carbonate is known.
However, since method 'a' uses a reaction solvent, steps such as solvent removal and purification are required, and the productivity is poor due to the large number of manufacturing steps. This method is disadvantageous as an industrial method because expensive raw materials such as diarylester of group dicarboxylic acid and diary carbonate are used.

In addition, as a method for producing polyester without such drawbacks,
A difunctional carboxylic acid mainly consisting of an aromatic dicarboxylic acid and an aromatic monohydroxy compound in an amount of 2.1 to 10 times the mole of the dicarboxylic acid were heated at 230 to 350 pm at an absolute pressure of 1 to 15 k9/m. Under the pressure of the earth, the carpoxyl group of the component is allowed to react until the reaction rate reaches 80% or more, and then a dihydroxy compound mainly consisting of an aromatic dihydroxy compound is added in an amount of 1 to 1.3 times the mole of the bifunctional carboxylic acid. A method for producing polyester characterized by an addition reaction has been proposed (see Japanese Patent Laid-Open No. 51-410941).
. This method uses aromatic dicarboxylic acid as a starting material and has the advantage of being able to easily and inexpensively produce polyester with excellent heat resistance, dimensional stability, transparency, and chemical resistance. It has drawbacks such as low workability such as the need to control the reaction pressure during the reaction, and high coloring of the polyester obtained. The inventor is
As a result of intensive studies aimed at improving these drawbacks, the present inventors discovered that polyester with excellent color tone can be quickly obtained by using a specific medium, leading to the present invention.

That is, the present invention provides (1) an aromatic monohydroxy compound [B] in an amount of 2.1 to 10 times the amount of the aromatic dicarboxylic acid and the amount of the bad component [B] and an aliphatic diol and/or A first step of esterifying dihydroxybenzene 'C} until the carpoxyl group value per gram of the reaction product becomes 1000 or less, and (D) adding the reaction product to the esterification reaction product of the first step. The total amount with the {q component in the product is 100 to 120 mol% relative to the dicarboxylic component.
In the method for producing an aromatic polyester, which comprises a second step of adding and reacting a large amount of bisphenols, the esterification reaction of the first step is replaced with aromatic carbonization having a boiling point of 105 to 175 qo under normal pressure. Hydrogen (E) and an aromatic dicarboxylic acid are allowed to coexist,
The method for producing aromatic polyester is characterized in that the method is carried out under reflux conditions of the dish ingredients.

Examples of aromatic dicarboxylic acids used as air components in the present invention include phthalic acids such as terephthalic acid, isophthalic acid, orthophthalic acid: 1,4-, 2,6-
, naphthalene dicarboxylic acids such as 2,7-naphthalene dicarboxylic acid; diphenyl dicarboxylic acids such as 4,4'-diphenyl dicarboxylic acid; diphenyl ether dicarboxylic acids such as 4,4'-diphenyl ether dicarboxylic acid; , diphenylsulfonedicarboxylic acids such as 4'-diphenylsulfonedicarboxylic acid, and diphenoxychetanedicarboxylic acids.

These may be used alone or in combination of two or more. Among these, terephthalic acid and isophthalic acid are particularly preferred. On the other hand, the aromatic monohydroxy compound used as the {B} component is a compound in which one hydroxy group is directly bonded to an aromatic ring, and examples thereof include phenol, cresol, naphthol, and the like.

Among these, phenol is particularly preferably used. The ratio of the aromatic monohydroxy compound {B) used is 2.1 to 10 times the mole of the aromatic dicarboxylic acid (2).

If this ratio is less than 2.1 moles, the reaction rate will be slow, and if it exceeds 10 moles, it will not be possible to expect a corresponding increase in the effect. The preferred ratio of aromatic monohydroxy compound used is 2% to aromatic dicarboxylic acid.
．． The amount is 1 to 5 times by mole, particularly 2.5 to 4.5 times by mole.

In addition, the aliphatic diol and/or dihydroxybenzene that can be used in combination with component 'B)' include:
For example, aliphatic glycols having 2 to 12 carbon atoms such as ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, neobenzene glycol, hexamethylene glycol, etc.; fats such as cyclohexane dimethylol, tricyclodecane dimethylol, etc. Group glycol; Pis(8-hydroxyethoxy)diphenyl sulfone, 4,4-pis(8-hydroxyethoxy)diphenyl ether, 2,2-pis(4-8
-hydroxyethoxyphenyl)ethane, 2,2-bis(4-8-hydroxyethoxyphenyl)propane, 1
, 1-bis(4-8-hydroxyethoxyphenyl)cyclohexane, p-bis(8-hydroxyethoxy)benzene, etc., and aliphatic diols having an aromatic ring in the molecule, and dihydroxy such as hydroquinone, resorcinol, etc. Benzene can be mentioned.

These may be used alone or in combination of two or more. The ratio of aliphatic diol and/or dihydroxybenzene 'C} used is 0 to aromatic dicarboxylic acid.
~0.5 mole times.

By using the [C} component, the reaction rate becomes faster. In the present invention, first, the aromatic dicarboxylic acid (1) and the aromatic mono/hydroxy compound 'B-' and, if necessary, an aliphatic diol and/or dihydroxybenzene 'C}
When reacting, the boiling point under normal pressure is 105~
175 0 aromatic hydrocarbon legs and aromatic dicarboxylic acid free ester ■ coexist.

Examples of the aromatic hydrocarbon having a boiling point of 105 to 17yo under normal pressure as component {E} include alkyl-substituted benzenes such as toluene, xylene, ethylbenzene, cumene, cymene, trimethylbenzene, and ethyltoluene.
Aromatic hydrocarbons with a boiling point of less than 10T○ have a high reaction pressure, and in some cases, it may be difficult to separate them from the water produced, or they may be distilled out before the water, or the reaction, which is one of the purposes of the present invention, may be difficult. It cannot be used because the effect of increasing speed is small. On the other hand, aromatic hydrocarbons with a boiling point exceeding 17% can only act as a diluent, and cannot be used because they slow down the reaction rate or color the polymer. The proportion of the aromatic hydrocarbon E} to be used is usually 0.1 to 10 times by weight, preferably 0.3 to 5 times by weight, and more preferably 0.5 to 3 times by weight relative to the aromatic dicarboxylic acid (I). If the amount of aromatic hydrocarbons is too low,
It is not preferable that the effect of promoting the esterification reaction is small, and if the amount is too large, it not only increases the size of the reaction apparatus but also reduces the reaction rate. Further, the aromatic dicarboxylic acid aryl ester of component [F} may be any one as long as it is thermally stable at the reaction temperature.

Examples include esters of dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4' diphenylcarboxylic acid, and the above-mentioned aromatic monohydroxy compounds. These aromatic dicarboxylic acid aryl esters are preferably those in which the acid component is the same as the aromatic dicarboxylic acid used as the harmful component from the viewpoint of reaction and post-treatment. As the aromatic dicarboxylic acid aryl ester, it is preferable to use one prepared in advance by an esterification reaction between an aromatic dicarboxylic acid and an aromatic monohydroxy compound, and in particular, the esterification reaction product of the first step of the present invention is used. It is preferable to use a part of. In the latter case, the esterification reaction product may contain esters of the wind component and the 'C} component, which are also used as part of the aromatic dicarboxylic acid aryl ester. The amount of aromatic dicarboxylic acid aryl ester used may be any amount as long as the component aromatic dicarboxylic acid can flow as a slurry, but it is usually 0% to the harmful component.
．． The amount is 2 to 4 times the mole. If the amount used is too small, the fluidity of the aromatic dicarboxylic acid will be lost, the reaction time will be prolonged, and the reaction pressure will not be lowered sufficiently, so that the desired effect cannot be expected. Furthermore, if the amount used is too large, the amount produced by a reactor with a fixed capacity will be smaller, which will lead to a decrease in the production efficiency of the production equipment, which is not preferable. The preferred amount of the aromatic dicarboxylic acid aryl ester used is 0.5 to 3 moles. Aromatic hydrocarbon [E
) and aromatic dicarboxylic acid aryl ester' are optional as long as they are added at a stage before 20% of the aromatic dicarboxylic acid as a starting material has reacted. Preferably, it is added to the system.

The most common method of addition is to charge the entire amount at the start of the reaction. Further, the addition of the aromatic dicarboxylic acid aryl ester can also be carried out by leaving a part of the aromatic dicarboxylic acid aryl ester produced in the previous batch in the reactor. In the present invention, the esterification reaction is usually carried out by charging air, components (B), 'C}, '9 and 'F) into a pressurized reactor equipped with a rice cracker tower or a fractionation tower,
The water produced by the reaction is distilled off from the upper part of the rectification column or fractionation column, and what is distilled off at this time is water, aromatic hydrocarbons coexisting in the reactor, and aromatic monomers. The aromatic hydrocarbon and aromatic monohydroxy compound, which is the hydroxy compound 'B-, from which water has been separated in liquid form from the distillate are refluxed to the reaction zone.

Refluxing is usually carried out by returning the mixture of aromatic hydrocarbons and aromatic monohydroxy compounds in liquid form to the reaction mixture, particularly into the aromatic dicarboxylic acid slurry, or by blowing the mixture in gaseous form into the aromatic dicarboxylic acid slurry. It is preferable that unreacted aromatic dicarboxylic acid residue is placed in an atmosphere of higher concentration of the aromatic monohydroxy compound. The molar ratio of aromatic monohydroxy compound to aromatic hydrocarbon during reflux is usually 20:1 to 1:1. Aromatic monohydroxy compounds are hydrophilic, and the degree of hydrophilicity increases as the temperature increases, so it is preferable to separate from water at as low a temperature as possible. In addition, by coexisting aromatic hydrocarbons, retention of by-product water is promoted, and the concentration of aromatic monohydroxy compounds in the crab exudate can be lowered, and the aromatic monohydroxy compounds and water can be combined. This has the advantage of making separation easier. In order to set the most favorable reaction conditions in the esterification reaction, it is necessary to set the reaction temperature to a temperature higher than the boiling point of the aromatic monohydroxy compound, but in this case, the aromatic monohydroxy compound in the aromatic dicarboxylic acid slurry is diluted. Some of them will exist only at certain concentrations, while others will exist in the reaction system in gaseous form, increasing the reaction pressure.

Therefore, the amount of aromatic hydrocarbon to be used is determined by taking into account the reaction pressure, reaction rate, mixing ratio with aromatic monohydroxy compound, separation of diaryl ester, etc. In addition, when using the esterification reaction product of the first stage as the aromatic dicarboxylic acid aryl ester, the charging ratio of component It is determined by carefully considering the amounts of the diol component and/or dihydroxybenzene component. For example, if the charging ratio of the wind component and {C) component is adjusted to the molar ratio of the dicarboxylic acid component and the aromatic diol component and/or dihydroxybenzene component in the esterification reaction product used as a component, the aromatic component will be continuously produced. This is preferable because the reaction system for producing the group polyester has a constant composition and is stabilized. The reaction temperature is usually 230 to 350 oo. 2
At a temperature lower than 30 qo, the reaction rate is too slow to be practical, and at a temperature higher than 350 qo, colored substances are produced due to side reactions such as decomposition reactions, which is not preferred.

The reaction pressure is selected to be such that the concentration of the aromatic monohydroxy compound in the slurry can be sufficiently increased and the generated water can be quickly removed, and a pressure of 1 to 15 k9/G is usually adopted. The esterification reaction is preferably carried out in the presence of a catalyst. As the catalyst, any known catalyst for producing an aryl ester from an aromatic carboxylic acid and an aromatic monohydroxy compound can be used. Preferred examples of these catalysts include titanium compounds, tin compounds, antimony compounds, and more specifically titanate alkyl esters such as titanium tetrabutoxide, titanium oxalate, titanium trimellitate, etc. Titanium carboxylates such as: tin carboxylates such as tin acetate; organic tin compounds such as dibutyltin oxide; antimony compounds such as antimony trioxide; and the like. The amount of these used is usually aromatic dicarboxylic acid■
0.001 to 5 mol%. The esterification reaction is carried out until the carboxyl group value per gram of the reaction product becomes 1000 or less, preferably 750 or less, more preferably 500 or less.

If the carboxyl group value exceeds 1000, the reaction with the bisphenols added next will not proceed sufficiently, making it impossible to obtain the desired polyester with a high degree of polymerization.
In this way, after the esterification reaction of component
B' component and/or 'E} component are produced and the following second stage reaction is performed.

The second stage reaction is carried out after adding bisphenols } to the reaction mixture of component (1) and component 'B'.

These bisphenols have the general formula [wherein X represents or -S02-, R,, R2 are each an alkyl having 1 to 6 carbon atoms or a hydrogen atom, and R, and R2 have a carbon number composed of 4-12
It is an alicyclic structure.

], such as 2,2-bis(4-hydroxyphenyl)propane [pisphenol A],
1,1-pis(4-hydroxyphenyl)cyclohexane [bisphenyl Z], 1,1-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)
Methane, 1,2-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)cyclohexylmethane, 3,3-bis(4-hydroxyphenyl)pentane, pis(4-hydroxyphenyl)sulfone [ Bisphenol Z] etc.

Although these can be used alone, two or more types can also be used in combination. Among these, bisphenol A, bisphenol Z' and bisphenol Z are particularly preferably used. In the second stage reaction, all or a part of the first stage reaction product or the product from which excess aromatic monohydroxy compound 'B- and/or aromatic hydrocarbon 'E} has been removed. The above-mentioned bisphenols are added, a transesterification reaction is carried out to distill off the by-produced aromatic monohydroxy compound, and then a polycondensation reaction is carried out, for example, while removing volatile substances under reduced pressure.

At that time, when using a part of the reaction product of the first stage for the second stage reaction, use the amount of the reaction product commensurate with the amount of aromatic dicarboxylic acid used in the first stage. is preferred. The preferred reaction temperature is 240 to 400 qo.
, more preferably 260 to 370q0, and a preferable pressure is 760 to 0.001 skin Hg. The reaction is usually carried out in a molten state, but if the resulting polymer has a high melting point, solid phase polymerization is also preferably employed. In the second stage reaction, the amount of bisphenols used is such that the total amount with dihydrobenzene and/or aliphatic diol in the reaction product supplied to the second stage is based on the total dicarboxylic brewing components in the reaction product. The amount is 120% by mole. Although aliphatic diols and/or hydroxybenzene may be added together with bisphenols, it is preferable that the final amount of bisphenols is 50 mol % or more based on the total diol components. The aromatic polyester thus obtained preferably has a reduced viscosity of 0.5 or more.

In the present invention, additives such as stabilizers and colorants that are commonly used in polyester production can be used without any problem. According to the present invention, a highly polymerized polyester having high heat resistance, excellent dimensional stability, transparency, chemical resistance, and color tone can be easily and inexpensively produced using an aromatic dicarboxylic acid as a starting material. can.

Further, the present invention has the advantage that the reaction pressure is low, the reaction operation is easy, and the reaction rate is high. The present invention will be explained in detail below with reference to Examples. In the examples, "part" means "part by weight", and the reduced viscosity (resp/c) is a value measured at 3yC in orthochlorophenol with C=1.2. In addition, the carboxyl group value is determined by the Konics method (N is cro.Molec ar.Chem.26
22,619$).

Furthermore, the b value of the color tone was measured using a CM-2 top-type color difference meter manufactured by Color Machine Co., Ltd. A large b value indicates a strong yellowish tinge. Example 1 Add 1 terephthalic acid to an autoclave equipped with a rice cracker tower and a Tsuruazusa machine.
33 parts, isophthalic 33 parts, phenol 56.4 parts, diphenyl terephthalate 50. After charging $ parts, 12.7 parts of diphenyl isophthalate, 5.0 parts of ethylbenzene, and 0.036 parts of tin acetate and purging with nitrogen, the autoclave was returned to normal pressure and heated.

While keeping the internal temperature at 290 oo, the created water and other fractions are extracted from the top of the distillation tower, the water in the distillate is separated, and the other fractions are placed in a slurry in the reaction system for 1 minute. The solution was refluxed using a metering pump at a rate of 0.8 parts per sample. After 2 hours of reaction, the system pressure was 3.
8k9/lump G, and a reaction product with a carboxyl group value of 99 degrees g/1 pg was obtained, and after 3 hours of reaction, the system pressure became 3.3k9/lump G, and a carboxyl group value of 1 & g/1.
A reaction product of Pig was obtained.

After completing the reaction for 3 hours, a portion of the reaction solution was transferred to a polycondensation apparatus capable of being vacuumed.

The liquid that moved is 30. It is a $ part, and it includes 16.5
parts of diphenyl terephthalate and 3.9 parts of diphenyl isophthalate were present. 4.6 parts of bisphenol AI was added to this reaction solution, and the reaction was carried out at normal pressure at 280° C. for 1 hour, and over another 30 minutes, the degree of vacuum was set to 0.5 cells/Hg, and the reaction temperature was set to 34,040°C. Subsequently, this state was maintained for 2 hours, and then the polymer was discharged. The discharged polymer glue sp/c is 0.85, and its color tone has an L value of 44.
．． 8 a value + 7.4 b value 126.7. Example 2 The method was exactly the same as in Example 1, but without using a metering pump, the reaction proceeded while the crab fractions other than water distilled out of the rectification column were refluxed in the upper part of the distillation column.

After 6 hours of reaction, the reaction pressure was 3.8 k9/g, and the carboxyl group value of the reaction product was 75 k9/g.
It became.

After continuing the reaction for another hour, the reaction pressure was 3.4 [9/
A reaction product with a carpoxyl group value of 4 g and 1 pg was obtained. At the end of the 7-hour reaction, a portion of the reaction solution was transferred to a polycondensation apparatus.

Claims (1)

[Scope of Claims] 1 (I) Aromatic dicarboxylic acid (A) and aromatic monohydroxy compound (B) in an amount of 2.1 to 10 times the mole of component (A) and 0 to 0.5 times the amount by mole of the aromatic monohydroxy compound (B). Reaction product 10^ with aliphatic diol and/or dihydroxybenzene (C)
The first step is to carry out an esterification reaction until the carboxyl group value per 6 g becomes 1000 or less, and (II) the reaction product of the first step is added to the reaction product in which the sum of component (C) in the reaction product becomes a dicarboxylic acid component. In the method for producing an aromatic polyester, the esterification reaction in the first step is carried out under normal pressure. The boiling point of
Aromatic hydrocarbon (E) and aromatic dicarboxylic acid aryl ester (F) at 05 to 175°C are allowed to coexist, and (
E) A method for producing an aromatic polyester, which is carried out under conditions of refluxing the components. 2. The method according to claim 1, wherein the amount of the aromatic dicarboxylic acid aryl ester (F) charged is 0.2 to 4 times the amount of the aromatic dicarboxylic acid (A) by mole. 3 Aromatic dicarboxylic acid aryl ester (F) as the first
3. The method according to claim 1 or 2, characterized in that the step is added at the start of the esterification reaction. 4 Aromatic hydrocarbon (E) with a boiling point of 105 to 175°C under normal pressure to aromatic dicarboxylic acid (A) in a ratio of 0.1 to
Claim 1 characterized in that 10 times the weight is used.
The method described in section. 5. The method according to claim 1 or 4, characterized in that the aromatic hydrocarbon (E) having a boiling point of 105 to 175°C under normal pressure is added at the start of the first stage esterification reaction. . 6. The method according to claim 1, characterized in that a mixture of an aromatic hydrocarbon (E) and an aromatic monohydroxy compound (B) having a boiling point of 105 to 175° C. under normal pressure is refluxed in a liquid state. Method.