KR101685747B1 - Method for preparing polycondensation resin - Google Patents

Abstract

The method for producing a polycondensation resin of the present invention comprises a step of producing a lower condensation product by a polycondensation reaction; A step of discharging the lower condensate out of the system; And a step of polymerizing the discharged low-order condensate to produce a polycondensation resin. The polycondensation reaction and polymerization are carried out in a batch reactor, and the step of discharging the low- The low-order condensate is discharged out of the system while replenishing the by-products produced in the polycondensation reaction or the same kind of material as the raw material of the polycondensation reaction into the system. The above production method can produce a polycondensation resin of stable quality in the batch polymerization method.

Description

METHOD FOR PREPARING POLYCONDENSATION RESIN [0002]

The present invention relates to a method for producing a polycondensation resin. More specifically, the present invention relates to a method for producing a polycondensation resin capable of producing a polycondensation resin of stable quality in a batch polymerization method.

Polyamide and polycondensation resins such as polycarbonate and polyester each have excellent properties as engineer plastics, and are widely used in the automobile field, the electric and electronic field, and the like. Various techniques for producing a polycondensation resin have been disclosed, but a continuous polymerization method, a batch polymerization method and the like are widely known.

For example, as a continuous polymerization method, there is a method in which a primary condensate is continuously polymerized in Patent Document 1 or the like and this is continuously high-polymerized (high molecular weight) in a short time in a melting machine to obtain a stable high molecular weight polycondensation resin . However, such a continuous polymerization method is capable of obtaining a polycondensation resin having a stable molecular weight only under specific production conditions, increasing the amount of the auxiliary equipment, increasing the amount of the investment, and facilitating the conversion of the resin type. .

As a batch polymerization method, a low-order condensate of a low-molecular-weight polycondensation resin such as Patent Document 2 is prepared, crystallized and / or granulated, and then subjected to solid-phase polymerization under vacuum or in an inert gas atmosphere, A method for producing a high molecular weight polycondensation resin is disclosed. However, in such a conventional batch polymerization method, when the polycondensate is discharged from each batch, there is a possibility that the molecular weight of the polycondensate is irregularly distributed due to the difference in the discharge time. As a result, There is a possibility of fluctuation.

Patent Document 1: JP-A-06-287299 Patent Document 2: JP-A-08-59824

An object of the present invention is to provide a method for producing a polycondensation resin capable of producing a polycondensation resin of stable quality in a batch polymerization method.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the present invention relates to a method for producing a polycondensation resin. The production method includes a step of producing a lower condensation product by a polycondensation reaction; A step of discharging the lower condensate out of the system; And a step of polymerizing the discharged low-order condensate to produce a polycondensation resin. The polycondensation reaction and polymerization are carried out in a batch reactor, and the step of discharging the low- The low-order condensate is discharged out of the system while replenishing the by-products produced in the polycondensation reaction or the same kind of material as the raw material of the polycondensation reaction into the system.

In a specific example, the by-product or the same kind of material as the raw material can be supplemented into the system so as to maintain the chemical equilibrium state of the reaction of the production of the lower condensate at the start of the discharge of the lower condensate.

In an embodiment, the amount to replenish the by-products or materials of the same kind as the raw materials into the system so as to maintain the chemical equilibrium state of the production reaction of the lower condensates at the start of discharge is expressed by Z Feed rate per unit time of the type of material): < RTI ID = 0.0 > 5%

[Formula 1]

In the above formula (1), Z (unit: kg / hr) is a unit of a by-product or a substance of the same kind (vapor phase) introduced to maintain the chemical equilibrium state of the production reaction of the lower condensate at the start of lower- feed (steam feed rate) per hour, and, P _x (unit: kPa) means the pressure in the system, and P _y (unit: kPa), the temperature (temperature of the reaction solution) in the system T (unit: K, T [ V (unit: m ³ ) means the volume of the reaction solution, Y (unit: kg / m ³ ) represents the volume of the reaction solution, Means the saturated vapor amount per unit volume (theoretical value) under the conditions of the temperature T and the saturated vapor pressure P _y , and L (unit: hr) means the time for discharging all of the lower condensates in the system.

In a specific example, the number average molecular weight of the lower condensate may be 5 to 50% of the number average molecular weight of the polycondensation resin.

In embodiments, the polycondensation resin may be a polyamide, polycarbonate, or polyester.

In an embodiment, the polycondensation resin may be one formed by solid phase polymerization of the lower condensate.

INDUSTRIAL APPLICABILITY The present invention has the effect of the invention which provides a method for producing a polycondensation resin capable of producing a polycondensation resin of stable quality in the batch polymerization method.

Hereinafter, the present invention will be described in detail.

A method for producing a polycondensation resin according to the present invention is a batch polymerization method in which a polycondensation reaction and polymerization are carried out in a batch reactor, comprising the steps of (A) producing a lower condensate by a polycondensation reaction, (B) A step of discharging the lower condensate out of the system, and (C) a step of polymerizing the lower condensate discharged to prepare a polycondensation resin. In the present invention, the step (B) of discharging the lower condensate out of the system is carried out while replenishing the by-product produced in the polycondensation reaction or a (gaseous) substance of the same kind as the raw material (monomer) .

In a specific example, the same kind of material as the by-product or raw material may be varied depending on the resin to be polymerized. For example, in the production of polyamide, polycarbonate, etc., the same material as the by- In manufacturing, materials of the same kind as the raw materials can be used.

In addition, the by-products or materials of the same kind as the raw materials can be supplemented into the system so as to maintain the chemical equilibrium state of the formation reaction of the lower condensates at the start of discharging the lower condensates.

(A) Lower Process for producing a condensate

In this step, a polycondensation reaction of a monomer is carried out to produce a low-order condensate of a polycondensation resin.

In the specific examples, the polycondensation resin is not particularly limited, but may be a polyamide, polycarbonate or polyester which can be produced on an industrial scale.

Hereinafter, monomers, catalysts and the like used for synthesis of polyamides, polycarbonates and polyesters will be described.

<Polyamide>

The polyamide can be obtained by polycondensation reaction of a dicarboxylic acid with a diamine and / or an aminocarboxylic acid and (solid phase) polymerization (high polymerization), and is not particularly limited.

Non-limiting examples of the dicarboxylic acid include malonic acid, dimethyl malonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2- Aliphatic dicarboxylic acids such as tartaric acid, 3,3-diethylsuccinic acid, suberic acid, azelaic acid, sebacic acid, undecane diacid and dodecane diacid; Cycloaliphatic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; Terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,4-phenylenedioxydiacetic acid, Dodecanoic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, 4,4'- Aromatic dicarboxylic acids such as biphenyl dicarboxylic acid; And the like. These may be used alone or in combination of two or more. If necessary, a small amount of a polyvalent carboxylic acid component such as trimellitic acid, trimesic acid, and pyromellitic acid may be used in combination.

Non-limiting examples of the diamine include ethylenediamine, propanediamine, 1,4-butanediamine, 1,6-hexanediamine (hexamethylenediamine), 1,7-heptanediamine, 1,3-butanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, Aliphatic diamines such as diamines, meta-xylylenediamine, and para-xylylenediamine; (4-aminocyclohexyl) methane, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, norbornanedimethanamine, tricyclo Alicyclic diamines such as decane dimethanamine; Aromatic diamines such as paraphenylenediamine, metaphenylenediamine, 4,4'-diaminodiphenylsulfone and 4,4'-diaminodiphenyl ether; And the like. These may be used alone or in combination of two or more.

As the aminocarboxylic acid, lactam such as laurolactam, aminocaproic acid, aminoundecanoic acid, and the like can be used, but it is not limited thereto.

A phosphorus-based catalyst can be used for the purpose of improving the polycondensation rate and preventing deterioration during polycondensation reaction in the production of polyamide. Examples of the phosphorus-containing catalyst include, but are not limited to, hypophosphite, phosphate, hypophosphorous acid, phosphoric acid, phosphoric acid ester, polymethanes, polyphosphoric acid, phosphine oxide, phosphonium halide, . For example, hypophosphite, phosphate, hypophosphorous acid, phosphoric acid, a mixture thereof and the like can be used. Examples of the hypophosphite include sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, magnesium hypophosphite, aluminum hypophosphite, vanadium hypophosphite, manganese hypophosphite, zinc hypophosphite, zinc hypophosphite, nickel hypophosphite, cobalt hypophosphite, Ammonium phosphite and the like can be used. Specifically, sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, magnesium hypophosphite and the like can be used. Examples of the phosphate include sodium phosphate, potassium phosphate, potassium dihydrogen phosphate, calcium phosphate, vanadium phosphate, magnesium phosphate, manganese phosphate, lead phosphate, nickel phosphate, cobalt phosphate, ammonium phosphate and ammonium dihydrogen phosphate. As the phosphoric acid ester, ethyl octadecyl phosphate and the like can be used. Examples of the polymetaphosphoric acids include sodium trimetaphosphate, sodium pentametaphosphate, sodium hexametaphosphate, and polymetaphosphoric acid. As the polyphosphoric acid, sodium tetrapolyphosphate and the like can be used. As the phosphine oxides, hexamethylphosphoramide and the like can be used. The phosphorus catalysts may be in the form of hydrates.

The amount of the phosphorus-containing catalyst to be added may be 0.0001 to 5 parts by weight, for example, 0.001 to 1 part by weight, based on 100 parts by weight of the monomer (feedstock). The addition time of the phosphorus catalyst may be added at any time until completion of (solid phase) polymerization, but it is preferably between the time of introduction of the raw material and completion of polycondensation of the lower condensate. Further, the catalyst may be added several times, or two or more different phosphorus-containing catalysts may be mixed and added.

The present process can also be carried out in the presence of an end-capping agent. When the end-capping agent is used, the molecular weight of the low-order condensate and the finally produced polyamide can be easily controlled, and the melt stability of the low-order condensate and the finally produced polyamide can be improved. The terminal endblock is not particularly limited as long as it is a monofunctional compound having reactivity with a terminal amino group or a terminal carboxyl group in a lower order condensate. Examples thereof include, but are not limited to, acid anhydrides such as monocarboxylic acid, monoamine and phthalic anhydride, monoisocyanate, monoacid halide, monoester, monoalcohol and the like. The end-cap encapsulant may be used singly or in a mixture of two or more. Specifically, a monocarboxylic acid or a monoamine can be used in consideration of reactivity and end-to-end stability, and more specifically, a monocarboxylic acid having excellent ease of handling can be used.

The monocarboxylic acid is not particularly limited as long as it is a monocarboxylic acid having reactivity with an amino group. Examples of the monocarboxylic acid include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, Aliphatic monocarboxylic acids such as listeric acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid; Alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; Aromatic monocarboxylic acids such as benzoic acid, toluic acid,? -Naphthalenecarboxylic acid,? -Naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid; And mixtures thereof. Specific examples include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, benzoic acid Etc. may be used.

The monoamine is not particularly limited as long as it is a monoamine having reactivity with a carboxyl group. For example, aliphatic monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine and dibutylamine; Alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; Aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine; And mixtures thereof. Specifically, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, aniline, and the like can be used in view of reactivity, boiling point, end-point stability and cost.

The amount of the endcapping agent used in the preparation of the lower condensate may be varied depending on the reactivity of the endcapping agent used, the boiling point, the reaction apparatus, the reaction conditions, and the like. For example, 15 mole fraction.

In this process, by-products such as water produced by the polycondensation reaction can be extracted out of the system, the reaction can be promoted. For this purpose, it is possible to use a method of removing the by-product together with an inert gas after crushing and / or introducing an inert gas to perform the reaction under reduced pressure.

<Polycarbonate>

The polycarbonate is not particularly limited and polycarbonates having various structural units can be exemplified. Typically, the polycarbonate may be an aromatic polycarbonate prepared by the reaction of a bifunctional phenol with a carbonate precursor.

Non-limiting examples of the divalent phenol include 4,4'-dihydroxybiphenyl, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) Bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl- Bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ketone, hydroquinone, resorcinol, catechol and the like. The dihydric phenol may be used alone or in combination of two or more. For example, bis (hydroxyphenyl) alkane can be used, and specifically, 2,2-bis (4-hydroxyphenyl) propane can be used as the main raw material.

Examples of the carbonate precursor include, but are not limited to, carbonyl halide, carbonyl ester, haloformate, and the like. For example, dihalo formates such as phosgene, dihalo formate of dihydric phenol, diaryl carbonates such as diphenyl carbonate, dialkyl carbonates such as dimethyl carbonate and diethyl carbonate, and the like, Reel carbonate can be used.

The polycarbonate may include those in which the molecular structure of the polymer chain is a linear structure as well as a branched structure. Branch bases for introducing such branched structures include 1,1,1-tris (4-hydroxyphenyl) ethane,?,? ',? "-Tris (4- hydroxyphenyl) P-tert-butylphenol, p-cumylphenol and the like may be used as the molecular weight regulator. Examples of the molecular weight regulator include phenol, pt-butylphenol, pt-octylphenol, Can be used.

In the present step (low-order condensate production process), the polycondensation reaction can proceed at a sufficient rate without addition of a catalyst, but a polymerization catalyst can be further used for the purpose of improving the reaction rate.

Such polymerization catalysts are not particularly limited as long as they are polycondensation catalysts used in this field, but include hydroxides of alkali metals and alkaline earth metals such as lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide; Alkali metal salts, alkaline earth metal salts and quaternary ammonium salts of hydrides of boron or aluminum such as lithium aluminum hydride, sodium borohydride, and tetramethyl ammonium borohydride; Hydrogenated compounds of alkali metals and alkaline earth metals such as lithium hydride, sodium hydride and calcium hydride; Alkoxides of alkali metals and alkaline earth metals such as lithium methoxide, sodium ethoxide and calcium methoxide; Aryloxides of alkali metals and alkaline earth metals such as lithium phenoxide, sodium phenoxide, magnesium phenoxide, LiO-Ar-OLi and NaO-Ar-ONa (Ar is an aryl group); Organic acid salts of alkali metals and alkaline earth metals such as lithium acetate, calcium acetate and sodium benzoate; Zinc compounds such as zinc oxide, zinc acetate and zinc phenoxide; Boron compounds such as boron oxide, boric acid, sodium borate, trimethyl borate, tributyl borate, and triphenyl borate; Silicon compounds such as silicon oxide, sodium silicate, tetraalkyl silicon, tetraaryl silicon and diphenyl ethyl ethoxy silicon; Germanium compounds such as germanium oxide, germanium tetrachloride, germanium ethoxide, and germanium phenoxide; Tin compounds such as tin compounds and organotin compounds bonded with an alkoxy group or aryloxy group such as tin oxide, dialkyltin oxide, dialkyltin carboxylate, tin acetate and ethyl tin tributoxide; Lead compounds such as lead oxide, lead acetate, lead carbonate, basic carbonates, alkoxides or aryl oxides of lead and organic lead; Onium compounds such as quaternary ammonium salts, quaternary phosphonium salts and quaternary arsenonium salts; Antimony compounds such as antimony oxide (such as antimony trioxide) and antimony acetate; Manganese compounds such as manganese acetate, manganese carbonate, and manganese borate; Titanium compounds such as titanium oxide, alkoxide or aryl oxide of titanium; Zirconium acetate, zirconium oxide, alkoxide or aryloxide of zirconium, and zirconium compounds such as zirconium acetylacetone; And the like. These polymerization catalysts may be used alone or in combination of two or more.

The amount of the polymerization catalyst used may vary depending on the reactivity of the polymerization catalyst to be used, the boiling point, the reaction apparatus, the reaction conditions, and the like. However, the amount of the polymerization catalyst is preferably 1 x 10 &lt; ^-9 to 1 part by weight, for example, 1 × 10 ^-7 to 1 × 10 ^-3 parts by weight. The addition timing of the polymerization catalyst may be added at any time until completion of the (solid phase) polymerization, but it is preferably between the time of introduction of the starting material and the completion of polycondensation of the low condensation product. Further, it may be added several times or two or more different polymerization catalysts may be mixed and added.

In the present step, by-products such as aromatic monohydroxy compounds produced by the polycondensation reaction are discharged outside the system, the reaction can be promoted. For this purpose, it is possible to use a method of carrying out the reaction under reduced pressure and / or a method of removing the by-product together with the inert gas after introduction of the inert gas.

<Polyester>

As the polyester, there is no particular limitation, and a polyester obtained by reacting an aromatic dicarboxylic acid or an aromatic dicarboxylic acid ester with an aliphatic diol or an acyl compound of a compound having a phenolic hydroxyl group can be exemplified.

The aliphatic diol may be, for example, an alkylene group having 2 to 10 carbon atoms, but is not limited thereto. Specific examples thereof include ethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,3-propanediol, 1,4-butanediol, 1,2-ethanediol, Hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, trimethylolpropane, neopentyl glycol, Diols, mixtures thereof, and the like. The alkylene group of the aliphatic diol may be substituted with an alkyl group, a halogen atom, an ether group or the like which is not involved in the esterification reaction according to the present invention.

As the acylate of the compound having a phenolic hydroxyl group, an acylate obtained by acylating an aromatic diol and / or a phenolic hydroxyl group of an aromatic hydroxycarboxylic acid with a fatty acid anhydride can be used. The compound having a phenolic hydroxyl group may have at least one phenolic hydroxyl group, but from the viewpoint of reactivity, it is preferable to have one or two phenolic hydroxyl groups. When the compound having a phenolic hydroxyl group has only one phenolic hydroxyl group, it is preferable that the compound having a phenolic hydroxyl group contains one carboxyl group. As the compound having a phenolic hydroxyl group, an aromatic diol and an aromatic hydroxycarboxylic acid are particularly preferable. Examples of the aromatic diol include 4,4'-dihydroxybiphenyl ("4,4'-biphenol"), hydroquinone, resorcinol, methylhydroquinone, chlorohydroquinone, acetoxyhydroquinone, Dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) Bis (4-hydroxyphenyl) methane, bis- (4-hydroxyphenyl) propane, -3,5-dimethylphenyl) methane, bis- (4-hydroxy-3,5-dichlorophenyl) methane, bis- (4-hydroxy- (4-hydroxyphenyl) methane, bis- (4-hydroxy-3-chlorophenyl) methane, 1,1- (4-hydroxyphenyl) ether (4,4'-dihydroxydiphenyl ether), bis- (4-hydroxyphenyl) ketone, bis 4-hydroxyphenyl) ketone, bis- (4-hydroxyphenyl) sulfide, bis- (4-hydroxyphenyl) sulfone, mixtures thereof and the like. . Of these, 4,4'-dihydroxybiphenyl, hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,2-bis (4-hydroxyphenyl) propane and bis- Phenyl) sulfone and the like are widely available.

Acylation of such a compound having a phenolic hydroxyl group gives an acylate. As the acyl group, there may be mentioned, but not limited to, acetyl group. Here, the acylation may be a reaction of a compound having a phenolic hydroxyl group with an acylating agent. As the acylating agent, acyl anhydride or halide is representative. The acyl group in the acylating agent may be an aliphatic carboxylic acid such as an alkanoic acid (acetic acid, propionic acid, butyric acid, pivalic acid, etc.), a higher alkanoic acid such as palmitic acid, an aromatic carboxylic acid such as benzoic acid, Lt; / RTI &gt; As the acylating agent, a fatty acid anhydride is particularly preferable. Examples of the fatty acid anhydrides include acetic anhydride, acetic anhydride, anhydrous butyric acid, anhydrous isobutyric acid, anhydrous valeric acid, anhydrous pivalic acid, anhydrous 2-ethylhexanoic acid, anhydrous monochloroacetic acid, anhydrous dichloroacetic acid, anhydrous trichloroacetic acid, Maleic anhydride, dibromoacetic anhydride, anhydrous tribromoacetic acid, anhydrous monofluoroacetic acid, anhydrous difluoroacetic acid, trifluoroacetic anhydride, anhydroglutaric acid, maleic anhydride, succinic anhydride, anhydrous? -Bromo Propionic acid, and mixtures thereof. Acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride and the like can be used from the viewpoint of cost and handling property, and acetic anhydride can be preferably used.

In the acylation reaction of the compound having a phenolic hydroxyl group, the amount of the fatty acid anhydride may be 1.0 to 1.2 equivalents based on the phenolic hydroxyl group. When the amount of the fatty acid anhydride to be used is less than 1.0 equivalent based on the phenolic hydroxyl group, the equilibrium during the acylation reaction may shift toward the fatty acid anhydride. Accordingly, when the polyester is polymerized with the polyester, the unreacted aromatic diol or aromatic dicarboxylic acid The acid may sublimate and the reaction system may be closed. When the amount of the fatty acid anhydride is more than 1.2 equivalents based on the phenolic hydroxyl group, the polyester may be colored.

The acylation reaction may be performed at 130 to 180 ° C, for example, at 140 to 160 ° C for 15 minutes to 20 hours, for example, 30 minutes to 5 hours.

In the present invention, the aromatic dicarboxylic acid or aromatic dicarboxylic acid ester which reacts with the aliphatic diol or the compound having a phenolic hydroxyl group-containing compound may be referred to as an aromatic dicarboxylic acid.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 1,5-naphthalene dicarboxylic acid, 4,4'-biphenyldicarboxylic acid, methylterephthalic acid, methyl Isophthalic acid, diphenyl ether-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenylketone-4,4'-dicarboxylic acid, 2,2'- Diphenyl propane-4,4'-dicarboxylic acid, and mixtures thereof. Of these, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid and the like are easily available and widely used.

Examples of the aromatic dicarboxylic acid ester include methyl, ethyl, propyl and phenyl esters of the aromatic dicarboxylic acid. These may be used alone or in combination of two or more.

The reaction of the aliphatic diol or the compound having a phenolic hydroxyl group with the aromatic dicarboxylic acid may be carried out at a sufficient rate without addition of a catalyst, but a polymerization catalyst may be further used for the purpose of improving the reaction rate . As the polymerization catalyst, a polycondensation catalyst used in this field can be used without limitation. For example, a polymerization catalyst used in the polycarbonate production (polycondensation reaction) described above can be used.

The amount of the polymerization catalyst to be used in the production of the lower condensate of the polyester may vary depending on the reactivity of the polymerization catalyst to be used, the boiling point, the reaction apparatus, the reaction conditions, etc., but is preferably 0.0001 to 5 parts by weight , For example, 0.0005 to 1 part by weight. The addition timing of the polymerization catalyst may be added at any time until completion of the (solid phase) polymerization, but it is preferably between the time of introduction of the starting material and the completion of polycondensation of the low condensation product. Further, it may be added several times or two or more different polymerization catalysts may be mixed and added.

In order to produce a polyester from an aliphatic diol and an aromatic dicarboxylic acid in the present step (low-order condensate production process), an aliphatic diol and an aromatic dicarboxylic acid are first subjected to an esterification reaction at 160 ° C or more and less than 250 ° C , And a polycondensation reaction can be carried out at 250 to 350 ° C. Further, in order to prepare an ester from an acylate of a compound having a phenolic hydroxyl group and a polyester from an aromatic dicarboxylic acid, an acylate of a compound having a phenolic hydroxyl group and an aromatic dicarboxylic acid are subjected to an esterification reaction or an ester exchange reaction , A polycondensation reaction can be carried out.

In this step, the reaction can be promoted by discharging a by-product produced by a polycondensation reaction or the like out of the system. For this purpose, it is possible to use a method of carrying out the reaction under reduced pressure and / or a method of removing the by-product together with the inert gas after introduction of the inert gas.

In an embodiment, the by-product resulting from the polyester polycondensation reaction (esterification reaction) of the aliphatic diol and the aromatic dicarboxylic acid is water or alcohol formed from the hydroxy group of the aromatic dicarboxylic acid or the alkoxy group of the aromatic dicarboxylic acid ester , And such water or alcohol can be discharged out of the system in order to shift the equilibrium so that the production of the polyester is favored.

Also, the by-products of the polycondensation reaction (esterification reaction or transesterification reaction) of the acylate of the compound having a phenolic hydroxyl group and the aromatic dicarboxylic acid are monocarboxylic acid, monocarboxylic acid ester, etc., A carboxylic acid, a carboxylic acid, a carboxylic acid, a carboxylic acid, a carboxylic acid, a carboxylic acid, a carboxylic acid, a carboxylic acid, a carboxylic acid or a monocarboxylic acid ester. If necessary, a part of the monocarboxylic acid or the like which is distilled off is refluxed to the reactor so that the raw material (aromatic dicarboxylic acid or the like) evaporated or sublimated together with the monocarboxylic acid or the like is returned to the reactor together with the reflux liquid It is possible. Also, during the esterification reaction or transesterification reaction of an acylate of a compound having a phenolic hydroxyl group and an aromatic dicarboxylic acid, an acylating agent such as an unreacted fatty acid anhydride contained in the acylate is also evaporated during the reaction, It is preferable to discharge (distill) it out.

In the process for producing a lower condensate of the present invention, lower condensates such as polyamides, polycarbonates and polyesters can be prepared by injecting each monomer or the like into a commonly used pressure polymerization reactor and stirring in a solvent or a solvent Lt; RTI ID = 0.0 &gt; C, &lt; / RTI &gt;

The solvent may be water or an alcohol such as methanol or ethanol. In addition, excessive raw materials such as aliphatic diols, by-products and the like may be used as a solvent at the beginning of the reaction.

The polycondensation reaction can be usually carried out by elevating the temperature and elevating the pressure under stirring conditions. At this time, the reaction temperature (polymerization temperature) can be adjusted after the feed, and the reaction pressure (polymerization pressure) can be adjusted according to the progress of the polymerization.

In the present step, the reaction temperature, the reaction pressure, and the reaction time may be suitably set according to the resin to be produced and are not particularly limited. For example, the reaction temperature may be from 170 to 400 캜, the reaction pressure may be from 0.5 to 3 MPa, and the reaction time may be from 0.5 to 10 hours. The polycondensation reaction is preferably carried out with stirring from the viewpoints of preventing adhesion of the lower condensation product to the reaction vessel, uniform progress of the polycondensation reaction, generation of the primary polycondensate powder having the same particle diameter, and the like.

(B) Lower Process of discharging the condensate out of the system

Next, in this step, the produced lower condensate is discharged from the reaction vessel (system).

The present invention is characterized by a process for extracting a lower condensate out of the system. Specifically, the step may be carried out by mixing the by-product produced in the polycondensation reaction or a (gaseous) substance of the same kind as the raw material (monomer) of the polycondensation reaction, for example, by producing the lower condensation product The low-order condensate is discharged out of the system while being replenished into the system so as to maintain the chemical equilibrium state of the reaction. By this feature, it is possible to suppress the fluctuation of the molecular weight of the lower condensate resulting from the time difference of the discharge when the lower condensate is extracted out of the system, and as a result, a polycondensed resin of stable quality can be obtained.

That is, in the present invention, when the lower condensate produced by the polycondensation reaction is discharged from the reactor (in the system), the space of the discharged lower condensate increases, And that the chemical equilibrium of the formation reaction of the lower condensation product is different from the state at the time when the lower condensation product starts to be discharged.

In the present invention, the term " by-product produced in the polycondensation reaction or a material of the same kind as the raw material (monomer) of the polycondensation reaction "which is supplemented into the system is a kind of the polycondensation resin to be produced, For example, in the production of polyamide, the by-product is water, and the by-product in the production of polycarbonate is an aromatic monohydroxy compound or the like. In the production of polyester produced from an aliphatic diol and an aromatic dicarboxylic acid , The by-products are water, alcohol, etc., and the by-products are monocarboxylic acids and monocarboxylic acid esters such as fatty acids in the production of polyester produced from an acylate of a compound having a phenolic hydroxyl group and an aromatic dicarboxylic acid.

Further, in the present invention, the process of replenishing the by-products or materials of the same kind as the raw materials into the system so as to maintain the chemical equilibrium state of the production reaction of the lower-order condensates at the start of lower condensation condensation, Means to introduce a by-product or a material of the same kind as the raw material into the system so that the vapor pressure of the by-product in the system at the start of discharge can be maintained. Here, the by-product or the same kind of raw material as the raw material to be supplied so as to maintain the vapor pressure of the by-product or raw material in the system at the time of starting the low-order condensate (maintaining the chemical equilibrium state of the reaction of generating the low- (Steam supply rate) of the substance (vapor phase) per unit time can be obtained, for example, by the following equation (1).

[Formula 1]

In the above formula (1), Z (unit: kg / hr) is a unit of a by-product or a substance of the same kind (vapor phase) introduced to maintain the chemical equilibrium state of the production reaction of the lower condensate at the start of lower- (Feed rate of steam) per hour,

P _x (unit: kPa) means the pressure in the system,

P _y (unit: kPa) means a saturated vapor pressure per unit volume (theoretical value) at a temperature (reaction solution temperature) T (unit: K, T [K] = T '[° C] +273.15)

V (unit: m ³ ) means the volume of the reaction solution,

Y (unit: kg / m ³ ) means the saturated vapor amount per unit volume (theoretical value) under the conditions of the temperature T and the saturated vapor pressure P _y ,

L (unit: hr) means the time for discharging all of the lower condensates in the system.

Here, P _y and Y can be obtained as follows.

The saturated vapor pressure (theoretical value) Py can calculate the saturated water vapor pressure (P _y = P _ws ) from the Wagner equation represented by the following formula 2 when the by-product or raw material is water, , The saturated vapor pressure (P _y = 0.01 P _aw ) can be calculated from the Antoine equation represented by the following formula (3). As an example of an organic compound, ananine constant of phenol and an aliphatic diol (ethylene glycol) as an example of an aromatic monohydroxy compound (a by-product in the production of a polycarbonate) is described. Such ananine constants can be determined by reference to, for example, the Chemical Manual, NIST WebBook, and the like.

[Formula 2]

In Equation 2, P _ws (unit: kPa) means Wagner's strict water vapor pressure,

P _c is 22120 kPa as the critical pressure,

A is -7.76451, B is 1.45838, C is -2.7758, D is -1.23303,

x is 1- (T / T _c ), where T _c is the critical temperature of 647.3 K and T (unit: K) is the temperature of the reaction solution.

[Formula 3]

In Equation 3, P _aw (unit: bar) means a saturated vapor pressure,

T (unit: K) is the temperature of the reaction solution,

A, B and C are ananine constants. In the case of phenol, A is 4.24688, B is 1509.677, C is -98.949, and in the case of ethylene glycol, A is 4.97012, B is 1914.951 and C is -84.996.

The saturation vapor amount (theoretical value) Y per unit volume can be calculated by the following equation 4 by using the ideal vapor state equation using the saturated vapor pressure Py at the predetermined temperature T of the by-product or raw material obtained by the above formula At this time, the volume is calculated as 1 m ³ ).

[Formula 4]

In Equation 4, Y (unit: kg / m ³ ) means the saturated vapor amount per unit volume (theoretical value) under the conditions of the temperature T and the saturated vapor pressure P _y ,

P _y (unit: kPa) means saturated vapor pressure per unit volume (theoretical value) at temperature T (unit: K)

T (unit: K) is the temperature of the reaction solution,

Mw (unit: g / mol) is the weight average molecular weight of the by-product or raw material,

R is the gas constant, 8.3145.

In the above formula (1), [Y x (P _x / P _y )] is the saturated vapor amount X (unit: kg / m ³ ) per unit volume in the reaction system. That is, by calculating the saturation vapor pressure (theoretical value) P _y , the saturated vapor amount Y per unit volume at the saturated vapor pressure P _y , and the pressure P _x in the reaction system on the basis of Bohr's law, the saturated vapor amount X per unit volume in the reaction system is X = Y x (P _x / P _y ) [kg / m ³ ]. Thus, the steam amount X can represent the amount of steam in the system at the start time of discharging the lower condensate out of the system.

The present invention replenishes gaseous by-products so that the vapor amount (X) can be maintained in the system when the lower condensate is discharged outside the system, thereby maintaining the chemical equilibrium state. The amount (unit: kg) of steam (by-product or material of the same kind as the raw material) to be added so as to maintain the vapor amount X is expressed by Y * (unit: m ³ ) P _x / P _y ) × V. Further, the steam supply amount (Z) per unit time for adding the steam amount for the predetermined time L can be expressed by the above-mentioned formula (1).

In the present invention, the respective numerical units of the above-mentioned formulas 1 to 4 can be used by being appropriately matched to pressure, volume, etc., and each unit of the formulas 1 to 4 is referred to as a reference.

In an embodiment, the amount of a by-product or a substance of the same kind as the raw material supplemented into the system at the time of discharging the low-order condensate to maintain the chemical equilibrium state of the low-order condensate formation reaction at the start of lower- For example, ± 3%, specifically ± 1% of the amount of steam supplied (steam supply rate) Z per unit time calculated by the above equation (1). Within the above range, it is possible to maintain the chemical equilibrium state of the reaction for producing a lower condensate at the start of discharge.

In the present invention, by introducing a by-product or a material of the same kind as the feedstock into the system at such a steam feed rate as described above, the low-order condensate is discharged without changing the chemical equilibrium state of the polycondensation reaction , The lower condensate can be discharged. Thereby, the molecular weight of the resulting lower condensate after discharge does not vary with the time difference at the time of discharge. That is, according to the present invention, a low-order condensate having a narrow molecular weight distribution can be obtained by using the above process, and by using it as a raw material for obtaining a polycondensate of high molecular weight, a polycondensation resin of stable quality having a narrow molecular weight distribution can be obtained.

In a specific example, the effect of the present invention can be obtained even if the byproduct supplied into the system or the vapor of the same kind of material as the raw material is fed into the reaction solution. However, in order to obtain a more excellent effect, it is preferable to introduce the vapor into the vapor phase portion.

In order to maintain the chemical equilibrium of the production reaction of the lower condensate of the polycondensation reaction, it is preferable that the temperature, pressure, and the like are kept the same as those in the reaction at the step of discharging the lower condensate.

In an embodiment, the lower condensate discharged from the reaction vessel may be recovered into the vessel at atmospheric pressure under an inert gas atmosphere. The inert gas atmosphere may prevent the oxidation deterioration of the low-order condensate, so that the oxygen concentration may be 1 vol% or less.

In an embodiment, the discharge speed of the lower condensate from the reaction vessel can be appropriately adjusted in accordance with the size of the reaction vessel, the amount of the contents in the reaction vessel, the temperature, the size of the discharge port, the length of the discharge nozzle, The logarithmic viscosity (IV) of the low-order condensate may be 0.05 to 1.50 dL / g, for example 0.08 to 1.00 dL / g, specifically 0.10 to 0.80 dL / g. In the present invention, deviation of the molecular weight of the polycondensate according to the time difference of the discharge is suppressed when discharging the low-order condensate, so that the logarithmic viscosity (IV) of the low-order condensate does not vary with the passage of time. For example, when the discharged low-order condensate is sampled at predetermined time intervals, the deviation of the logarithmic viscosity of each sample is very small. That is, the logarithmic viscosity average value of the samples sampled every predetermined time may be within the above-mentioned range, and their standard deviation may be 0.05 or less, for example, less than 0.04, and the coefficient of variation may be 2.5 or less, for example 2.0 or less. The sampling at every predetermined time is not particularly limited, but may be, for example, sampling performed every 10 minutes or the like. The logarithmic viscosity (IV) can be obtained according to the method of the later-described example.

In a specific example, the number average molecular weight of the low-order condensate may be 5 to 50%, such as 7 to 50%, specifically 8 to 50%, of the number average molecular weight of the finally obtained polycondensation resin. For example, the number average molecular weight of the lower condensation product may be 500 to 25,000 g / mol, such as 700 to 20,000 g / mol, specifically 800 to 18,000 g / mol. In the present specification, the number average molecular weight of the condensate is determined by using polymethyl methacrylate (pMMA) as a standard material in the case of polyamide and polyester and polystyrene in the case of polycarbonate. Quot; means a value measured by gel permeation chromatography (GPC).

In the case of the polyamide, the low-order condensate discharged from the reaction vessel by the above method is instantaneously dropped to 100 ° C or lower due to the latent heat of evaporation of water at the time of discharge, so that thermal deterioration and oxygen deterioration hardly occur . The low-order condensate can be obtained in a state of high polymerization in the state of the low-order condensation product to obtain a polycondensation resin. However, it is preferable to obtain a polycondensation resin by making the low-

Since the discharged lower condensate evaporates most of the water accompanied by the sensible heat of the lower condensate, the cooling and drying treatment of the lower condensate can be performed at the same time in this step. In addition, when the discharge treatment is performed in an atmosphere of an inert gas such as nitrogen, the efficiency of drying and cooling can be enhanced. In the case of providing a cyclone-type solid-gas separation device as a discharge container of the lower condensate, It is possible to suppress the out-of-range scattering and to perform the discharge treatment at a high gas flux rate, thereby improving the drying and cooling efficiency.

The low-order condensate thus obtained has a high logarithm viscosity and a low residual amount of unreacted materials. Therefore, when the polymerization is carried out at a high polymerization degree by solid-state polymerization, which will be described later, Solid-state polymerization can be performed at a high temperature, and deterioration due to side reactions may be small

If necessary, the lower condensation product may be subjected to a treatment for increasing the bulk specific gravity, a compacting treatment for uniformizing the particle size, a granulation treatment, and the like, and then the high polymerization degree described later can be performed.

In a specific example, a lower condensate such as a polycarbonate may be obtained in the form of a powder, a granule or the like by treating it with a crystallization solvent when it is in a molten state or a solution state. The method of treating with the above crystallization solvent is not particularly limited, but usually, the lower condensation product of the polycarbonate is stirred in the crystallization solvent to crystallize it in a slurry state, or the lower condensation product and the crystallization solvent are mixed And then crystallized by mixing or kneading. In the case of crystallization in a slurry state, a device having a high-speed stirring blade such as a waring blender or a device provided with a swirl pump with a cutter may be used. In the case of crystallization using a mixer or a kneader, a device called a mixer or a kneader (powder industry manual, Japan Daily Newspaper, articles 644 to 648, etc.) can be used. For example, a cone blender, A ribbon blender, a shovel mixer, a pug mixer-Henschel mixer, a brabender, and a twin-screw kneader.

Examples of the crystallization solvent include esters such as ethyl acetate; Ethers such as diethyl ether; Ketones such as acetone and methyl ethyl ketone; And the like. Depending on the temperature condition of the crystallization, hydrocarbons such as hexane and octane; Cyclic hydrocarbons such as cyclohexane; Can also be used as a crystallization solvent. Of these, acetone is preferred because a low-order condensate of polycarbonate having a large specific surface area can be produced.

(C) Low emission A step of polymerizing the condensate to prepare a polycondensation resin

In this step, the lower condensate discharged from the reaction vessel (system) is polymerized to produce a polycondensation resin. It is preferable that the polycondensation resin of the present invention is obtained by solid-phase polymerization of the low-order condensate to obtain high polymerization degree.

In a specific example, the solid state polymerization can be carried out continuously using the lower condensate as obtained from the reaction vessel, and can be carried out after drying the lower condensate taken out from the reaction vessel. The low-order condensate taken out from the reaction vessel may be stored after being temporarily stored. Alternatively, the low-order condensation product taken out of the reaction vessel may be subjected to the compacting treatment or the granulation treatment. When the degree of polymerization is increased by solid phase polymerization, a polycondensation resin having less thermal deterioration can be obtained.

The polymerization method and conditions for the solid phase polymerization of the low-order condensate are not particularly limited, and it suffices as long as it is a method and conditions capable of achieving high polymerization while maintaining the solid state without causing fusion, aggregation, deterioration, etc. of the low- . Preferably, solid phase polymerization can be carried out in an inert gas atmosphere such as helium gas, argon gas, nitrogen gas, carbon dioxide gas or the like or under reduced pressure to prevent oxidation deterioration of the lower condensate and the resulting polycondensation resin.

The temperature for the solid phase polymerization is not particularly limited, but the maximum reaction temperature may be, for example, 170 to 350 ° C. The maximum reaction temperature may be reached at any time from the initiation of solid phase polymerization to the end of solid phase polymerization.

The solid phase polymerization apparatus used in the present process is not particularly limited, and any known apparatus can be used. Specific examples of the solid phase polymerization apparatus include uniaxial disk type, kneader, biaxial paddle type, vertical type apparatus, vertical type apparatus, rotary drum type or double cone type solid phase polymerization apparatus, drying apparatus and the like.

The reaction time of the solid state polymerization is not particularly limited, but may be, for example, 1 to 20 hours. During the solid phase polymerization reaction, the lower condensate may be mechanically stirred or stirred in a gas stream.

In the present invention, various fiber materials such as glass fiber and carbon fiber, an inorganic powdery filler, an organic powdery filler, a colorant, an ultraviolet ray, and the like may be used in the step of producing the low-order condensate, Additives such as an absorbent, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, a crystallization promoter, a plasticizer, a lubricant and the like may be added.

The polycondensation resin produced according to the production method of the present invention is excellent in physical properties such as heat resistance, dynamic performance, low water absorption, chemical resistance and the like and is stable. Therefore, the polycondensation resin may be used alone or, if necessary, in the form of a composition with the above-mentioned various additives and other polymers, and various molding methods and spinning methods conventionally used for the polycondensation resin, such as injection molding, blow molding, It can be molded into various molded articles or fibers by a molding method such as extrusion molding, compression molding, drawing, vacuum molding, melt spinning or the like. The molded products such as fibers obtained by the molding method and the like are useful for various uses such as industrial plastics, industrial materials, housewares, etc., such as electronic plastics, automobile parts, and office parts, as well as applications as engineering plastics.

Hereinafter, the present invention will be described in more detail by way of examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Property evaluation method

The logarithmic viscosity (IV), molecular weight, melting point, crystallization temperature and color were evaluated by the following method.

(1) logarithmic viscosity (IV)

The sample was dissolved in a solvent at a concentration of 0.5 g / dL to prepare a sample solution. The polyamide used was 96% concentrated sulfuric acid as the solvent, dichloromethane was used as the polycarbonate, and o-chlorophenol was used as the polyester. The solvent and the sample solution were measured at a temperature of 25 캜 using a Uberoide viscometer and the falling water was measured by the following equation (5).

[Formula 5]

η _inh (logarithmic viscosity) = In (η _rel ) / c

In the equation (5), 侶_rel is t1 / t0 (where t1 is the falling number of samples, t0 is the falling number of blanks), and c is the solution concentration (g / dL).

(2) Molecular weight

(Number-average molecular weight (Mn) and weight-average molecular weight (Mw), unit: g / mol) were obtained by dissolving 10 mg of a resin sample in 10 g of a solvent using Shodex GPC-101 manufactured by Showa Denko K.K. ). In the measurement of the molecular weights of the polyamide and the polyester, two columns of HFIP-806M were used as the column, hexafluoroisopropanol (HFIP) was used as a solvent, and polymethylmethacrylate (pMMA) was used as a standard sample. In the measurement of the molecular weight of the polycarbonate, three columns of LF-804 were used as a column, tetrahydrofuran (THF) as a solvent and polystyrene as a standard sample. The measurement conditions of the GPC were a column temperature of 40 占 폚 and a solvent flow rate of 1.0 ml / min. The data processing software obtained the number average molecular weight (Mn) and the weight average molecular weight (Mw) using SIC-480II, which is the same company product as described above.

(3) Melting point, crystallization temperature

The sample in an amorphous state was heated to 30 ° C to 350 ° C at a rate of 10 ° C / min in a nitrogen atmosphere at a flow rate of 10 ml / min using DSC manufactured by Seiko Instrument Co., Ltd., and maintained for 5 minutes And the temperature was measured at a cooling rate of 10 ° C / min up to 200 ° C. The endothermic peak temperature due to melting at the time of temperature increase was determined as the melting point, and the exothermic peak temperature due to crystallization at the time of temperature decrease was measured as the crystallization temperature.

(4) Color (YI)

The YI value was measured using a small-color whitened NW-11 manufactured by Nippon Denshoku Kogyo Co., Ltd. (Nippon Denshoku Industries Co., Ltd.).

(5) Saturated vapor pressure

When the by-product or the raw material is water, the saturated vapor pressure (P _y , P _y = P _ws ) is calculated from the Wagner equation represented by the following formula 2. In the case of the organic compound (phenol, ethylene glycol) The saturation vapor pressure (P _y , P _y = 0.01 P _aw ) was calculated from the Antoine equation.

[Formula 2]

In the above equation 2, P _ws (unit: kPa) means Wagner's strict water vapor pressure, P _c is 22120 kPa as a critical pressure, A is -7.76451, B is 1.45838, C is -2.7758 and D is -1.23303 , x is 1- (T / T _c ), where T _c is the critical temperature of 647.3 K, and T (unit: K) is the temperature of the reaction solution.

[Formula 3]

In the formula 3, P _aw (unit: bar) means a saturated vapor pressure, T (unit: K), and if the is the temperature of the reaction solution, A, B and C are as St is constant, phenol, A is 4.24688 , B is 1509.677, C is -98.949, and in the case of ethylene glycol, A is 4.97012, B is 1914.951, and C is -84.996.

Example

Example  1: Preparation of polyamide

As a raw material, 44.84 kg (0.270 kmol = 65 mol%) of terephthalic acid, 21.24 kg (0.145 kmol = 35 mol%) of adipic acid, 48.93 kg (0.421 kmol = 100 mol%) of 1,6-hexamethylenediamine, , 1.52 kg of benzoic acid (0.012 kmol = 3 molar parts with respect to 100 molar parts of dicarboxylic acid), 115 g of sodium hypophosphite monohydrate (0.1 part by weight with respect to 100 parts by weight of the feedstock) and 77.8 kg of water 40 parts by weight with respect to parts by weight) was poured into an internal 500 L autoclave reaction vessel equipped with a disperser, a pressure adjusting valve, an inner window, a liquid level gauge and a bottom outlet valve. Next, the content was stirred and the temperature was raised to 130 캜 over 1 hour, and it was confirmed that the content became a homogeneous solution. Next, the internal temperature was raised to 250 DEG C over 3 hours and maintained. After the internal pressure reached 3.8 MPa, the reaction was continued for 2 hours while distilling off the water to maintain the same temperature and pressure. Thereafter, while maintaining the reaction temperature at 250 ° C, the pressure was lowered to 3.4 MPa for 30 minutes, the reaction was terminated at the time when 51 kg of water distillation was confirmed (water content of the reaction liquid was 25% by weight) Respectively.

And the amount of reaction liquid at the start of discharge was 128 L. The opening of the bottom discharge valve and the discharge adjustment valve was adjusted to discharge the reaction solution for 1.1 hours. During the discharge of the reaction liquid, in order to maintain the chemical equilibrium of the reaction liquid state (chemical equilibrium of the formation reaction of the lower condensate), water vapor in an amount sufficient to keep the amount of water as a by- Respectively. The supply rate Z of the water vapor is determined by obtaining the saturated water vapor pressure P _y (P _ws ) (250 ° C, 4.0 MPa) at the temperature in the autoclave according to the Wagner equation (formula 2) Calculate the saturated water vapor amount Y (16.5 kg / m ³ under the same conditions) and the saturated water vapor amount Y x (P _x / P _y ) [kg / m ³ ] in the reaction system and consider the volume V and the discharge time L , The amount of water vapor introduced per unit time (steam introduction rate) was set to 1.6 kg / hour:

[Formula 1]

In the above formula (1), Z (unit: kg / hr) is a unit of a by-product or a substance of the same kind (vapor phase) introduced to maintain the chemical equilibrium state of the production reaction of the lower condensate at the start of lower- feed (steam feed rate) per hour, and, P _x (unit: kPa) means the pressure in the system, and P _y (unit: kPa), the temperature (temperature of the reaction solution) in the system T (unit: K, T [ V (unit: m ³ ) means the volume of the reaction solution, Y (unit: kg / m ³ ) represents the volume of the reaction solution, Means the saturated vapor amount per unit volume (theoretical value) under the conditions of the temperature T and the saturated vapor pressure P _y , and L (unit: hr) means the time for discharging all of the lower condensates in the system.

[Formula 4]

(Unit: kg / m ³ ) in Equation 4 means the saturated vapor amount per unit volume (theoretical value) under the conditions of the temperature T and the saturated vapor pressure P _y , P _y (unit: kPa) K is the temperature of the reaction solution, Mw is the weight average molecular weight of the by-product or raw material, R is the weight of the gas As a constant, it is 8.3145.

Here, the water vapor was supplied into the autoclave using a metering pump, passed through a preheater, and supplied with saturated steam. During the discharge operation, the temperature of the reactor was maintained at 250 占 폚, and the pressure regulating valve maintained the water vapor pressure at 3.4 MPa in the fully closed state. The resulting low condensation condensate was discharged from the bottom discharge valve into the vessel under a nitrogen atmosphere at room temperature (25 ° C) and atmospheric pressure. The discharging operation of the lower condensate could stably discharge the entire amount. The lower condensate immediately after discharge had a temperature of 83 캜 and a water content of 1.8% by weight. Sampling was performed every 0.1 hour from the start of discharge, and the logarithmic viscosity (IV) was measured for each sample. As a result, the average value of IV of each sample was 0.13 dL / g, the standard deviation was 0.003, and the coefficient of variation was 2%. That is, the fluctuation in the ash was very small, and the quality was stable. In addition, the discharged lower condensate was solidified, and all of the lower condensates were pulverized and mixed, and the number average molecular weight (Mn) was 1,200 g / mol.

10 kg of the obtained lower condensation product was poured into a conical tumbler having an inner volume of 50 L with an oil jacket, and after nitrogen replacement, the pressure was reduced to 0.13 kPa. The heating oil was circulated while maintaining the vacuum, the internal temperature was raised to 245 DEG C over 2 hours, and then the solid-phase polymerization reaction was continued at the same temperature for 5 hours. After a predetermined reaction time had elapsed, the reaction mixture was cooled to room temperature (25 DEG C) to obtain a polyamide having a high polymerization degree.

The average value (n = 10) of the obtained polyamide (polycondensation resin) was 0.86 dL / g, the standard deviation was 0.015, and the coefficient of variation was 2%. The variation within the batch was very small, and the quality was stable. According to the DSC measurement, the melting point was 324 ° C, the crystallization temperature was 294 ° C, YI was 2, and Mn was 12,000 g / mol.

Example  2: Preparation of polyamide

35.10 kg (0.195 kmol as hexamethylenediamine) of an aqueous solution of 45.00 kg (0.172 kmol) of pre-adjusted polyamide 66 salt, 33.60 kg (0.202 kmol) of terephthalic acid, 64.5 weight% of hexamethylenediamine, and 12.5 kg of distilled water, Was injected into an internal 500 L autoclave reaction vessel equipped with a regulating valve, an intumescent window, a level gauge and a bottom discharge valve, and nitrogen substitution was carried out. The mixture was heated to 130 DEG C for 1 hour with stirring, and it was confirmed that the content became a homogeneous solution. Thereafter, the internal temperature was maintained at a temperature of 255 캜 for 3.5 hours. The reaction was then terminated at a reaction temperature of 260 DEG C and an internal pressure of 4.0 MPa, and the discharge operation was started.

The amount of reaction liquid at the start of discharge was found to be 88.8 L in the liquid level meter. The opening of the bottom discharge valve and the discharge adjustment valve was adjusted to discharge it for 0.9 hours. During the discharge of the reaction liquid, water vapor in an amount sufficient to keep the amount of water as a by-product of the reaction and the solvent constant so as to maintain the chemical equilibrium of the reaction liquid state (chemical equilibrium of the formation reaction of the lower condensate) Respectively. The supply rate Z of the water vapor was calculated by the following equation (1) and equation (2) using the same method as in Example 1, and the saturated water vapor pressure P _y (P _ws ) at 260 ° C on the basis of a saturated water vapor Y and (19.1 kg / m ³ under the same conditions), water vapor _{Y × (P x / P y} ) [kg / m 3] calculated, and the volume (V), the discharge time (L a in the reaction system ), The amount of water vapor supplied per unit time (water vapor supply rate) was set to 1.6 kg / hour. Here, the water vapor was supplied into the autoclave using a metering pump, passed through a preheater, and supplied with saturated steam.

During the discharge operation, the temperature of the reactor was maintained at 260 占 폚, and the pressure regulating valve was kept in a fully closed state and the water vapor pressure was kept at 4.0 MPa. The resulting low condensation condensate was discharged from the bottom discharge valve into the vessel under a nitrogen atmosphere at room temperature (25 ° C) and atmospheric pressure. The discharging operation of the lower condensate could stably discharge the entire amount. The lower condensate immediately after discharge had a temperature of 85 캜 and a water content of 2.3% by weight. Sampling was performed every 0.1 hour from the start of discharge, and the logarithmic viscosity (IV) was measured for each sample. As a result, the average value of IV of the sample was 0.16 dL / g, the standard deviation was 0.003, and the coefficient of variation was 2%. The variation within the batch was very small, and the quality was stable. The Mn of the obtained lower condensation product was 1,500 g / mol.

10 kg of the obtained lower condensation product was poured into a conical tumbler having an inner volume of 50 L with an oil jacket, and after nitrogen replacement, the pressure was reduced to 0.13 kPa. The heating oil was circulated while maintaining the vacuum, the internal temperature was raised to 245 DEG C over 2 hours, and then the solid-phase polymerization reaction was continued at the same temperature for 5 hours. After a lapse of a predetermined reaction time, the mixture was cooled to room temperature (25 캜) to obtain a polyamide having a high polymerization degree.

The average value (n = 10) of the obtained polyamides IV was 0.95 dL / g, the standard deviation was 0.025, and the coefficient of variation was 3%. The variation within the batch was very small and the quality was stable. According to the DSC measurement, the melting point was 301 占 폚, the crystallization temperature was 268 占 폚, YI was 5, and Mn was 14,500 g / mol, and a high heat-resistant polyamide excellent in color with high polymerization degree was obtained.

Comparative Example  1: Preparation of polyamide

The synthesis of the lower condensate was carried out under the same conditions as in Example 1 except that no steam was supplied during the discharge operation. As a result, the discharging operation was stopped because the contents liquid solidified at the time of about 80% discharge. Sampling was carried out every 0.1 hour from the start of discharge. The average value of IV of the obtained lower condensate was 0.15 dL / g, the standard deviation was 0.027, and the coefficient of variation was 18%. The variation within the ash was large. The Mn of the obtained lower condensation product was 1,500 g / mol.

The obtained low-condensation product was subjected to solid phase polymerization in the same manner as in Example 1. As a result, many adherents from the low-molecular-weight water were observed after the completion of the reaction. The average value (n = 10) of IV of the obtained polyamide was 0.68 dL / g, the standard deviation was 0.038, and the coefficient of variation was 6%. The IV was low and the fluctuation in the ash content was large as compared with the polyamide of the examples. The melting point by the DSC measurement was 315 ° C, the crystallization temperature was 295 ° C, YI was 8, and Mn was 9,800 g / mol.

Comparative Example  2: Preparation of polyamide

The synthesis of the lower condensates was carried out under the same conditions as in Example 2 except that water was supplied at 15 L / hr from the metering pump during the discharge operation and the water vapor pressure was kept at 4.0 MPa. As a result, the discharge operation could be performed satisfactorily. Sampling was carried out every 0.1 hour from the start of discharge, and the IV value of the obtained low-order condensate was 0.13 dL / g, standard deviation was 0.025, and coefficient of variation was 19%. That is, the fluctuation in the ash was large. The Mn of the obtained lower condensation product was 1,200 g / mol.

The resulting low-condensation product was solid-phase-polymerized in the same manner as in Example 2, and many adherents derived from low-molecular-weight water were observed after the completion of the reaction. The IV average value (n = 10) of the obtained polyamide was 0.71 dL / g, the standard deviation was 0.043, and the coefficient of variation was 6%. The IV was low and the variation within the ash was large as compared with the examples. The melting point by DSC measurement was 300 占 폚, the crystallization temperature was 275 占 폚, YI was 9, and Mn was 10,300 g / mol.

Example  3: Synthesis of polycarbonate

(2 mol) of 2,2-bis (4-hydroxyphenyl) propane and 446 g (2.08 mol) of diphenyl carbonate were placed in a polymerization reactor equipped with a mechanical stirrer, a condenser and a pressure- And 0.112 mg of potassium hydroxide were placed and the polycondensation reaction was carried out at a temperature of 240 캜 and a pressure of 1.3 kPa (10 torr) while the phenol as a reaction by-product was discharged from the stirring tank for 2 hours. After completion of the reaction, the decompression was stopped, and 12.8 g of phenol was fed into the system at a high temperature HPLC pump while maintaining the temperature at 240 캜, and the pressure was set to 400 kPa, which is the saturated vapor pressure of phenol. The amount of reaction solution was 540 mL. The opening of the bottom discharge valve and the discharge adjustment valve was adjusted to discharge it for 0.25 hours. During the discharge of the reaction liquid, in order to maintain the chemical equilibrium of the reaction liquid state (chemical equilibrium of the formation reaction of the lower condensate), phenol in an amount sufficient to keep the amount of phenol, which is a by-product of the reaction, . The feeding rate Z of the phenol was determined by finding the saturated phenol vapor pressure P _y (0.01 P _AW ) (240 ° C, 400 kPa) at the temperature in the autoclave from the above-mentioned Antonin formula (Formula 3) Calculate the amount of saturated phenol vapor Y (8.8 g / L = 8.8 kg / m ³ under the same conditions) and the amount of saturated phenol vapor Y x (P _x / P _y ) [kg / m ³ ] in the reaction system , And the volume (V) and the discharge time (L) were taken into account, to be 19.1 g / hour. The feed of phenol was carried out in a high temperature HPLC pump, in an autoclave, as a saturated phenol vapor.

During the evacuation operation, the temperature of the reactor was maintained at 240 占 폚, the pressure regulating valve was kept in a fully closed state, and the phenol vapor pressure was maintained at 400 kPa. The resulting low condensation condensate was discharged from the bottom discharge valve into the vessel under a nitrogen atmosphere at room temperature (25 ° C) and atmospheric pressure. The discharging operation of the lower condensate could stably discharge the entire amount. The samples were sampled at 0 minute, 5 minutes, 10 minutes and 15 minutes after discharge and the logarithmic viscosity (IV) of each sample was measured. As a result, all of the samples were 0.14 dL / g, It was very small, and the quality was stable. The lower condensate of the polycarbonate collected in the vessel was pulverized, added with acetone, crystallized, and dried at 100 ° C under reduced pressure to obtain a polymer powder. The obtained polycarbonate lower condensate (grains) had an IV of 0.14 dL / g, a Tm of 226 ° C and a Mn of 2,900 g / mol.

100 g of the polycarbonate lower condensation product was poured into a 500 mL rotary evaporator made of glass and solid-phase polymerized for 2 hours under a vacuum of 0.13 kPa at 220 rpm at 30 rpm. The average value (n = 5) of IV of the obtained polycarbonate was 0.45 dL / g, a standard deviation of 0.006, and a variation coefficient of 1.4%. The variation within the batch was very small, and the quality was stable. Further, the Mn of the obtained polycarbonate was 11,800 g / mol.

Comparative Example  3: Synthesis of polycarbonate

After completion of the polycondensation reaction, the decompression was stopped, and the temperature was maintained at 240 占 폚, and in place of phenol, nitrogen was used instead of phenol, and the pressure was also set to 400 kPa during discharge, polycarbonate Of a lower condensate. IV of the obtained lower condensate was 0.14 dL / g after 0 minutes of discharge, 0.15 dL / g after 5 minutes, 0.15 dL / g after 10 minutes, and 0.16 dL / g after 15 minutes, Respectively. Mn was 3,100 g / mol.

The obtained low-condensation product was solid-phase-polymerized in the same manner as in Example 3 above. The average value (IV) of the obtained polycarbonate (n = 5) was 0.46 dL / g, the standard deviation was 0.012, and the coefficient of variation was 2.6%. The fluctuation in ash was about twice as large as that in Example 3. The Mn of the obtained polycarbonate was 12,100 g / mol.

Example  4: Synthesis of polyester

830 g (5 mol) of terephthalic acid, 372 g (6 mol) of ethylene glycol, and 373 mg of antimony trioxide were fed into a stirring tank of a polymerization reactor equipped with an autoclave stirring vessel having an inner volume of 2 L, a condenser and a pressure- The esterification reaction was carried out at a temperature of 260 캜 and a pressure of 100 kPa for 5 hours while discharging the produced water. Next, the temperature was raised to 280 DEG C, the pressure was gradually reduced to 5 torr, and the polycondensation reaction was carried out while allowing the water as a reaction by-product to flow out from the stirring tank for 2 hours.

After completion of the reaction, the decompression was stopped, and ethylene glycol as a reaction raw material was introduced into a 10.8 g system in a high-temperature HPLC pump while maintaining the temperature at 280 占 폚, and the pressure was set to 750 kPa which is the saturated vapor pressure of ethylene glycol. The reaction liquid amount was 960 mL. The opening degree of the bottom discharge valve and the discharge amount regulating valve was adjusted so as to discharge it in one hour. During the discharge of the reaction liquid, in order to maintain the chemical equilibrium of the reaction liquid state (chemical equilibrium of the formation reaction of the lower condensate), ethylene glycol in an amount sufficient to keep the amount of the ethylene glycol as the reaction raw material is supplied to the gas phase portion Respectively. The feeding rate Z of ethylene glycol was obtained by obtaining the saturated ethylene glycol vapor pressure P _y (P _aw ) (750 kPa at 280 ° C) at the temperature in the autoclave from the Antoine equation, (10.1 g / L = 10.1 kg / m 3 under the same conditions) and the saturated ethylene glycol vapor amount Y x (P _x / P _y ) [kg / m 3] in the reaction system on the basis of the following equation (6) , And the volume (V) and the discharge time (L) were taken into account, thereby obtaining 9.7 g / hour. The feeding of ethylene glycol was carried out in a high-temperature HPLC pump, into an autoclave, and performed as saturated ethylene glycol vapor.

During the evacuation operation, the temperature of the reactor was maintained at 280 占 폚, the pressure regulating valve was kept in a fully closed state, and the ethylene glycol vapor pressure was maintained at 750 kPa. The resulting low-order condensate was extracted from the bottom discharge valve into water in a strand shape, cooled, and pelletized in a strand cutter to obtain a low-order condensation product of polyethylene terephthalate. The discharging operation of the lower condensate was stable, so that it was possible to discharge the whole amount. Samples were taken after 0 minute, 10 minutes, 20 minutes, 30 minutes, and 60 minutes after discharge, and the logarithmic viscosity (IV) of the samples was measured and found to be 0.52 dL / g. The variation within the batch was very small, and the quality was stable. The IV of the resulting polyethylene terephthalate lower condensation product was 0.52 dL / g, and the Mn was 14,800 g / mol.

100 g of the pellets were poured into a 500-mL rotary evaporator made of glass, crystallized at 170 DEG C for 2 hours under a nitrogen atmosphere, and solid-phase polymerized for 12 hours under a vacuum of 0.13 kPa at 220 rpm at 30 rpm. The average value (n = 5) of the obtained polyethylene terephthalate IV was 0.86 dL / g, the standard deviation was 0.004, and the variation coefficient was 0.5%. The variation within the batch was very small, and the quality was stable. The Mn of the obtained polyester (polyethylene terephthalate) was 31,100 g / mol.

Comparative Example  4: Synthesis of polyester

After completion of the polycondensation reaction, the decompression was stopped and the temperature was maintained at 280 DEG C, and using nitrogen instead of ethylene glycol, the pressure was maintained at 750 kPa during discharge, To obtain a low-order condensation product of polyethylene terephthalate. The IV of the obtained lower condensate was 0.53 dL / g after 0 minutes, 0.53 dL / g after 10 minutes, 0.54 dL / g after 20 minutes, 0.55 dL / g after 30 minutes, and 0.57 dL / g after 60 minutes , And IV showed a tendency to increase toward the second half of the year. Mn was 15,800 g / mol.

The obtained low-condensation product was subjected to solid-state polymerization in the same manner as in Example 4. The average value (n = 5) of IV of the obtained polyethylene terephthalate was 0.90 dL / g, the standard deviation was 0.016, and the coefficient of variation was 1.8%. The fluctuation in the ash was about four times larger than that in the example. The Mn of the obtained polyester (polyethylene terephthalate) was 33,300 g / mol.

The conditions for producing the lower condensates of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1, and the evaluation results are shown in Table 2. The conditions for producing the lower condensates of Examples 3 and 4 and Comparative Examples 3 and 4 are shown in Table 3, and the evaluation results are shown in Table 4.

From Table 2 and Table 4, it can be seen that the polycondensation resin produced according to the production method of the present invention does not change the molecular weight according to the time difference at the time of discharging the lower condensation product, so that stable quality can be obtained. Further, it can be seen that a polycondensation resin of stable quality can be obtained by (solid-state) polymerization of a lower-order condensate of stable quality.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (6)

A step of producing a lower condensate by a polycondensation reaction;
A step of discharging the lower condensate out of the system; And
And a step of polymerizing the discharged lower condensate to prepare a polycondensation resin,
The polycondensation reaction and polymerization are carried out in a batch reactor,
The step of discharging the lower condensate out of the system may be a step of discharging a by-product produced in the polycondensation reaction or a material of the same kind as the raw material of the polycondensation reaction into a vapor phase to produce a lower condensation product And discharging the lower condensate out of the system while replenishing it through the vapor phase portion to maintain the chemical equilibrium state.
delete 2. The method according to claim 1, wherein the amount for replenishing the by-product or the same kind of material as the raw material into the system so as to maintain the chemical equilibrium state of the production reaction of the lower condensation product at the start of discharge is expressed by Z The supply amount per unit time of a material of the same kind as that of the material of the polycondensation resin) is ± 5%
[Formula 1]

In the above formula (1), Z (unit: kg / hr) is a unit of a by-product or a substance of the same kind (vapor phase) introduced to maintain the chemical equilibrium state of the production reaction of the lower condensate at the start of lower- feed (steam feed rate) per hour, and, P _x (unit: kPa) means the pressure in the system, and P _y (unit: kPa), the temperature (temperature of the reaction solution) in the system T (unit: K, T [ V (unit: m ³ ) means the volume of the reaction solution, Y (unit: kg / m ³ ) represents the volume of the reaction solution, Means the saturated vapor amount per unit volume (theoretical value) under the conditions of the temperature T and the saturated vapor pressure P _y , and L (unit: hr) means the time for discharging all of the lower condensates in the system.
The method for producing a polycondensation resin according to claim 1, wherein the number average molecular weight of the lower condensate is 5 to 50% of the number average molecular weight of the polycondensation resin.
The method for producing a polycondensation resin according to claim 1, wherein the polycondensation resin is a polyamide, polycarbonate, or polyester.
The method of producing a polycondensation resin according to claim 1, wherein the polycondensation resin is formed by solid phase polymerization of the lower condensate.