JP2003212981A - Method for producing copolyester resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a target resin by improving the reaction conversion of a sublimable diol in conducting the polycondensation step in producing a copolyester resin using the sublimable diol as the raw material and to provide a method for stably producing the resin without clogging the reduced-pressure portions of piping and the like in the production apparatus due to the sublimation of the sublimable diol. <P>SOLUTION: The method produces a copolyester resin comprising a dicarboxylic acid constituting unit and a diol constituting unit and, simultaneously, a unit formed from a sublimable diol in the diol constituting unit by (1) a step of distilling off water and/or an alcohol to produce an oligomer, (2) a step of mainly distilling off a nonsublimable diol to perform transesterification until the amount of the sublimable diol comes to ≤10 wt.% based on its added amount, and (3) a step of allowing the oligomer to have a high molecular weight under reduced pressure. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to sublimation of a dicarboxylic acid and / or an ester-forming derivative thereof and a sublimable diol and a non-sublimable diol as raw materials for producing a copolyester resin. A polyester resin production apparatus for producing a desired copolyester resin efficiently by increasing the reaction conversion rate of a diol having a volatile property and reducing the dissipation of the sublimable diol to the outside of the reaction system due to sublimation. The present invention relates to a method for stably producing a polyester resin without blocking the piping or the like in the depressurization section.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter referred to as "P
ET ") is characterized by excellent transparency, mechanical performance, melt stability, solvent resistance, aroma retention, recyclability, etc., and is widely used for films, sheets, hollow containers, etc. There is. However, since heat resistance is not always good, modification by copolymerization is widely performed. It is generally known that when a polymer is modified with a compound having a cyclic acetal skeleton, heat resistance, adhesiveness, flame retardancy and the like are improved due to the rigid skeleton of the cyclic acetal and the acetal bond.

For example, 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane (hereinafter sometimes referred to as "SPG"). It has been described that the PET modified by (1) has a high glass transition point and excellent heat resistance (see Patent Document 1). Further, a copolymerized polyester container excellent in transparency and heat resistance, which is manufactured from terephthalic acid, 1,4-butanediol, glycol having a cyclic acetal skeleton, and the like, and a manufacturing method thereof are disclosed (Patent Document 2).
reference). Moreover, as a polyester having excellent heat resistance and transparency, a polyester using a diol having a cyclic acetal skeleton is mentioned in Examples (see Patent Document 3).

On the other hand, as an example of utilizing the adhesiveness derived from an acetal bond, a polyester-based adhesive, an adhesive composition and a coating agent using a diol having a cyclic acetal skeleton containing SPG and a dicarboxylic acid as raw materials are disclosed. (See Patent Documents 4, 5, 6, and 7).
In addition, as polyesters using dicarboxylic acids and diols having a cyclic acetal skeleton as raw materials, polyester shrinkage differentially mixed yarn, modified polyester film, biodegradable polyester, toner for electrostatic charge development, flame retardant resin composition Etc. are disclosed (Patent Documents 8, 9, 1)
0, 11, 12). However, these patent publications and the like do not disclose any specific polymerization method.

[0005]

[Patent Document 1] US Pat. No. 2,945,008

[Patent Document 2] Japanese Patent No. 2971942

[Patent Document 3] Japanese Patent Publication No. 7-13128

[Patent Document 4] Japanese Patent Publication No. 4-22954

[Patent Document 5] Japanese Patent Publication No. 5-69151

[Patent Document 6] Japanese Patent Publication No. 6-29396

[Patent Document 7] Japanese Patent Laid-Open No. 4-88078

[Patent Document 8] Japanese Patent Application Laid-Open No. 3-130425

[Patent Document 9] JP-A-8-104742

[Patent Document 10] JP-A-9-40762

[Patent Document 11] Japanese Patent Publication No. 3-14345

[Patent Document 12] Japanese Patent Laid-Open No. 2000-344939

Usually, the polyester resin is produced by a transesterification method or a direct esterification method. In the transesterification method, an excess amount of diol is added to the dicarboxylic acid dialkyl ester, which is a monomer, in an amount about twice the molar amount, and an ester, which is a diol ester of the dicarboxylic acid, is obtained by transesterification under normal pressure. It is a method of polycondensation under reduced pressure. However, when a copolyester is produced by using ethylene glycol and SPG as a diol by the transesterification method, it is difficult to directly obtain the target copolyester because ethylene glycol is preferentially transesterified. There was a problem. Further, even if the diol having a sublimation property does not necessarily have a slower transesterification reaction rate than the diol having no sublimation property, it is difficult to obtain a target copolyester. Further, there is a problem that unreacted SPG having sublimability remaining in the oligomer is sublimated by the temperature rise and the pressure reduction in the polycondensation step to block the pipe of the pressure reducing portion of the reactor. Further, since SPG was dissipated from the reaction solution by sublimation during the polycondensation reaction, there was a problem that the copolymerization rate of SPG in the obtained polyester resin was far from the target rate.

On the other hand, the direct esterification method is a method in which a dicarboxylic acid is esterified with a diol to obtain an oligomer which is a diol ester of a dicarboxylic acid, and then polycondensed under reduced pressure. However, even when a copolyester is obtained by using SPG and ethylene glycol by the direct esterification method, similar to the transesterification method, the sublimation of SPG causes blockage of the piping in the reaction device, which makes stable production difficult. there were. In any of the above-mentioned patent publications, a method for efficiently oligomerizing a diol having a sublimable cyclic acetal skeleton, a blockage of a pipe of a depressurizing portion due to the sublimation property of the sublimable diol, etc. , The problem of dissipation to the outside of the reaction system, and the solution thereof are not disclosed at all.

[0008]

In view of the above situation, the object of the present invention is to use, as a raw material, a dicarboxylic acid and / or an ester-forming derivative thereof, and a diol having a sublimation property and a diol having no sublimation property. In the production of the copolyester resin, the reaction conversion rate of the sublimable diol during the polycondensation step is improved to obtain the target copolyester resin, and the reaction by sublimation of the sublimable diol is performed. Disclosed is a method for stably producing a polyester resin, which reduces the dissipation to the outside of the system and does not block the piping or the like in the depressurization section of the polyester resin production apparatus.

[0009]

Means for Solving the Problems As a result of intensive studies made by the present inventors, a copolyester obtained by using a dicarboxylic acid and / or an ester-forming derivative thereof, a sublimable diol and a non-sublimable diol as raw materials. When a resin is produced, a diol having no sublimation property is used as a reaction system between a step of obtaining an oligomer by a transesterification reaction or an esterification reaction and a step of increasing the molecular weight of the oligomer by a polycondensation reaction under reduced pressure. Add a process of distilling and removing outside,
By setting the reaction conversion rate of the diol having sublimability mainly by transesterification to a certain ratio or more, the concentration of the unreacted diol having sublimability remaining in the oligomer is reduced, and as a result, the sublimation occurs during the polycondensation reaction. It has been found that it is possible to reduce the dissipation of sublimable diols due to sublimation, and to obtain the target copolyester. Furthermore, it is possible to stably stabilize the depressurization part of the polyester resin production equipment without blocking the piping and the like. The inventors have found that manufacturing can be performed and have reached the present invention.

That is, the present invention comprises at least a dicarboxylic acid constitutional unit formed from a dicarboxylic acid and / or an ester-forming derivative thereof, and a diol constitutional unit formed from a sublimable diol and a non-sublimable diol. A method for producing a copolyester resin containing 5 to 60 mol% of a unit formed from a diol having sublimability in a diol constitutional unit, wherein a diol having no sublimability is used as a raw material. Water and / or the ester-forming derivative until the reaction conversion rate of the dicarboxylic acid and / or its ester-forming derivative is 85 mol% or more, and is added in excess of the amount of the diol having no sublimation property. (1) in which the alcohol derived from is distilled to produce an oligomer, and then the reaction temperature is Under conditions of 50 to 250 ° C. and a reaction pressure not higher than the vapor pressure of the non-sublimable diol and not lower than the vapor pressure of the sublimable diol, mainly the non-sublimable diol is distilled out to carry out the reaction. A step (2) of transesterifying until the amount of the sublimable diol remaining in the oligomer solution is 10% by weight or less with respect to the amount of the sublimable diol added to the system; and further under reduced pressure. The invention relates to a method for producing a copolyester resin, which comprises the step (3) of increasing the molecular weight of the oligomer.

The present invention will be described in detail below.
The method for producing the copolyester resin of the present invention comprises dicarboxylic acid and / or its ester-forming derivative (hereinafter, dicarboxylic acid and its ester-forming derivative may be collectively referred to as "dicarboxylic acid component") and sublimation. Esterification of a diol component composed of a diol having a property and a diol having no sublimation property (hereinafter, "a diol having a sublimation property and a diol having no sublimation property may be collectively referred to as a" diol component ") And / or a transesterification reaction to distill off water or alcohol to once produce an oligomer which is a diol ester of dicarboxylic acid (step (1)), and then a diol having no sublimation property. A step of distilling and transesterifying to increase the reaction conversion rate of the diol having sublimability (step (2)), Furthermore mainly sublimable diol was distilled out no to the oligomer, characterized in that it comprises a step of high molecular weight (step (3)) after.

In the method for producing a copolyester resin of the present invention, a dicarboxylic acid and / or its ester-forming derivative, a diol having sublimability and a diol having no sublimability are used as raw materials. In the present invention, the sublimable diol has a sublimation pressure of 600 kP at 0 to 300 ° C.
The diols having a or less than a and the diols having no sublimation property are diols other than this. The sublimable diol used in the present invention is not particularly limited, for example, neopentyl glycol, catechol,
2,3-naphthalenediol, 3,9-bis (1,1-
Dimethyl-2-hydroxyethyl) -2,4,8,10
-Tetraoxaspiro [5.5] undecane, 5-methylol-5-ethyl-2- (1,1-dimethyl-2-hydroxyethyl) -1,3-dioxane and the like can be mentioned. In the present invention, the addition ratio of the sublimable diol is about 5 to 60 mol% with respect to the dicarboxylic acid component. With this ratio, the unit formed from the sublimable diol in the diol constitutional unit of the target copolyester resin can be 5 to 60 mol%.

The diol having no sublimability used in the present invention is not particularly limited, but the vapor pressure of the diol is higher than that of the diol having sublimability under the esterification temperature condition and the transesterification temperature condition. It is desirable that it is also high. As the diol having no sublimation property, for example, ethylene glycol, trimethylene glycol,
1,4-butanediol, 1,5-pentanediol,
Aliphatic diols such as 1,6-hexanediol, diethylene glycol and propylene glycol, polyether compounds such as polyethylene glycol, polypropylene glycol and polybutylene glycol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,2-decahydronaphthalene dimethanol, 1,3-decahydronaphthalene dimethanol, 1,
4-decahydronaphthalenedimethanol, 1,5-decahydronaphthalenedimethanol, 1,6-decahydronaphthalenedimethanol, 2,7-decahydronaphthalenedimethanol, tetralindimethanol, norbornenedimethanol, tricyclodecanedimethan Alicyclic diols such as methanol and pentacyclododecandimethanol,
4,4 '-(1-methylethylidene) bisphenol,
Methylene bisphenol (bisphenol F), 4,
4'-Cyclohexylidene bisphenol (bisphenol Z), 4,4'-sulfonylbisphenol (bisphenol S) and other bisphenols and alkylene oxide adducts of bisphenols, hydroquinone, resorcin, 4,4'-dihydroxybiphenyl, 4,4 '-
Examples thereof include aromatic dihydroxy compounds such as dihydroxydiphenyl ether and 4,4′-dihydroxydiphenylbenzophenone, and alkylene oxide adducts of aromatic dihydroxy compounds. Among these, ethylene glycol is particularly preferable in terms of mechanical performance and economical efficiency of the copolyester resin.

The dicarboxylic acid component used in the present invention is
Although not particularly limited, for example, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, decanedicarboxylic acid, norbornanedicarboxylic acid, tricyclo acid. Decanedicarboxylic acid, pentacyclododecanedicarboxylic acid, 3,9-bis (1,
1-dimethyl-2-carboxyethyl) -2,4,8,
10-Tetraoxaspiro [5.5] undecane, 5-
Carboxy-5-ethyl-2- (1,1-dimethyl-2
-Carboxyethyl) -1,3-dioxane and other aliphatic dicarboxylic acids and their ester-forming derivatives, terephthalic acid, isophthalic acid, phthalic acid, 2-methylterephthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5 -Aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, biphenyldicarboxylic acid and tetralindicarboxylic acid, and ester-forming derivatives thereof. Aromatic dicarboxylic acids and / or ester-forming derivatives thereof are preferred from the viewpoint of mechanical performance and thermal performance of the copolyester resin, and terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and / or ester formation thereof are particularly preferable. Sexual derivatives are preferred. The ester-forming derivative of a dicarboxylic acid of the present invention is a compound capable of forming a dicarboxylic acid ester, and examples thereof include a dicarboxylic acid dialkyl ester, a dicarboxylic acid dihalide, and a dicarboxylic acid diamide. Among these, dicarboxylic acid dialkyl ester is preferable, and dicarboxylic acid dimethyl ester is particularly preferable.

In the present invention, glycolic acid, lactic acid,
Oxyacids such as 2-hydroxyisobutyric acid and 3-hydroxybutyric acid, monoalcohols such as butyl alcohol, hexyl alcohol and octyl alcohol, and trivalent or higher polyhydric alcohols such as trimethylolethane, trimethylolpropane, glycerin and pentaerythritol. Also, monocarboxylic acids such as benzoic acid, propionic acid and butyric acid can be used within a range not impairing the object of the present invention. In the method for producing a copolyester resin of the present invention, a conventionally known production apparatus used for producing a polyester resin can be used as it is.

In the step (1) of the present invention, a dicarboxylic acid component and a diol component are subjected to an esterification and / or transesterification reaction to distill water and / or an alcohol derived from the ester-forming derivative to dicarboxylic acid. It is an oligomerization step for producing an oligomer that is a diol ester of an acid component. The oligomer solution in the present invention refers to a mixture composed of a diol ester of a dicarboxylic acid component having an average degree of polymerization of 10 or less and a monomer component composed of the dicarboxylic acid component and the diol component. The addition ratio of the diol component in the step (1) is an excess molar ratio with respect to the dicarboxylic acid component, but usually 1.
It is about 3 to 10 mol times, and in practice, the amount of the non-sublimable diol added as a raw material is 1.3 to 10 mol times more than the amount of the non-sublimable diol forming the copolyester resin. Added to. The temperature condition for producing the oligomer in the step (1) is not particularly limited, but is preferably 80 to 240 ° C., particularly preferably 100.
~ 230 ° C. The pressure in the step (1) is not particularly limited, but is preferably 40 to 600 kPa, particularly preferably 80 to 400 kPa. The reaction conversion rate of the dicarboxylic acid component in the step (1) is 85 mol% or more,
It is preferably 90 mol% or more. When the reaction conversion rate of the dicarboxylic acid component in the step (1) is less than 85 mol%, it is difficult to achieve a practically sufficient transesterification reaction rate in the subsequent step (3), and the polycondensation time becomes long, Not only is it economically unfavorable, but it is also not preferred because it gives an extra heat history to the copolyester resin.

The step (1) of the present invention may be carried out without a catalyst or with a catalyst. The catalyst may be any conventionally known one, and is not particularly limited, and examples thereof include sodium, alkoxide of magnesium, zinc, lead, cerium, cadmium, manganese, and cobalt.
Fatty acid salts such as lithium, sodium, potassium, calcium, nickel, magnesium, vanadium, aluminum, titanium, germanium, antimony and tin,
Examples thereof include carbonates, phosphates, hydroxides, chlorides, oxides, and magnesium metal. These may be used alone or in combination. The amount of the catalyst used in step (1) is preferably about 0.0001 to 5 mol% based on the dicarboxylic acid component.

In the step (2) of the present invention, the reaction temperature is 150.
˜250 ° C., the reaction pressure is not higher than the vapor pressure of the non-sublimable diol, and is higher than the vapor pressure of the sublimable diol. With respect to the amount of the sublimable diol added to, the amount of the sublimable diol remaining in the oligomer solution (hereinafter, referred to as "residual ratio of sublimable diol").
There is a thing. ) Is 10% by weight or less, a transesterification reaction. The reaction temperature in step (2) is 150 to 250 ° C., preferably 180 to 24 ° C.
0 degreeC, Especially preferably, it is 200 degreeC-230 degreeC. The reaction pressure in the step (2) is preferably equal to or lower than the vapor pressure of the diol having no sublimability in the above temperature range and equal to or higher than the vapor pressure of the diol having sublimability, and particularly preferably 10 to 100 kPa. By setting the reaction temperature and the reaction pressure within the above ranges, the sublimable diol can be efficiently distilled out of the reaction system without substantially sublimating the sublimable diol.

The residual ratio of the sublimable diol in the oligomer solution in the step (2) of the present invention is 10% by weight.
It is preferably 7% by weight or less, more preferably 5% by weight or less. By distilling the non-sublimable diol out of the reaction system, the residual ratio of the sublimable diol can be relatively easily adjusted to the above range. The amount of diol having no sublimation property is not particularly limited, but the amount of the diol component is 2 relative to the dicarboxylic acid component in the oligomer (including the dicarboxylic acid component forming the oligomer and the unreacted dicarboxylic acid component). It is preferable to distill until the amount becomes 0.0 times or less, preferably 1.7 times or less, and more preferably 1.5 times or less. By carrying out the distillation in the above range, the equilibrium of the reaction system shifts in the direction in which the sublimable diol reacts, so that the residual ratio of the sublimable diol can be 10% by weight or less.

By carrying out the above transesterification reaction,
It becomes possible to obtain the target copolyester resin by improving the reaction addition rate of the sublimable diol, and further reduce the dissipation of the sublimable diol to the outside of the reaction system due to sublimation. It is possible to stably produce the polyester resin without blocking the piping or the like in the depressurizing section.

The step (2) of the present invention may be carried out without a catalyst or with a catalyst. Any conventionally known catalyst can be used, and the catalyst is not particularly limited, and examples thereof include those exemplified in the step (1). These may be used alone or in combination. The catalyst used in the step (1) can be used as it is. The amount of the catalyst used in the step (2) is 0.0001 to 5 relative to the dicarboxylic acid component.
About mol% is preferable.

In the step (3) of the present invention, the oligomer obtained in the step (2) is further produced by a polycondensation reaction, and a diol having no sublimation property is mainly distilled out of the reaction system to increase the molecular weight. It is a process to do. The temperature of the reaction product at the start of step (3) is preferably 150 to 250 ° C,
The degree of vacuum is raised and the temperature is raised, and finally 250 to 3
It is particularly preferable to carry out at 00 ° C. When the temperature of the reaction product in the step (3) is 300 ° C. or higher, a side reaction such as thermal decomposition may occur during polycondensation, which is not preferable. The pressure at the start of the step (3) can be 10 to 100 kPa, but in a preferred embodiment, it is desirable that the pressure be gradually reduced to finally 400 Pa, particularly preferably 200 Pa, and further preferably 100 Pa. By setting the final pressure in the step (3) to 400 Pa or less, the reaction rate in the polycondensation reaction can be kept high, and undesired side reactions such as depolymerization reaction and thermal decomposition reaction can be suppressed along with the polycondensation reaction. It becomes possible. The step (3) is preferably performed until the average value of the degree of polymerization of the polyester resin becomes 20 or more.

In the method for producing a copolyester resin of the present invention, the formation of the copolyester resin at the end of step (3) is based on the amount of all sublimable diols added to the reaction system in step (1). The introduction ratio of the sublimable diol used in the above (hereinafter sometimes referred to as “the introduction ratio of the sublimable diol”) is 95.
It is at least mol%, preferably at least 97 mol%.

The step (3) of the present invention may be carried out without a catalyst or with a catalyst. Any conventionally known catalyst can be used, and the catalyst is not particularly limited, and examples thereof include those exemplified in the step (1). These may be used alone or in combination. The catalyst used in the step (1) can be used as it is. The amount of the catalyst used in the step (3) is 0.0001 to 5 with respect to the dicarboxylic acid component.
About mol% is preferable.

In the method for producing a polyester resin of the present invention, various stabilizers such as known etherification inhibitors, heat stabilizers, light stabilizers, polymerization regulators, etc. can be used.
Specific examples of the etherification inhibitor include amine compounds. It is also effective to add various phosphorus compounds such as phosphoric acid, phosphorous acid and phenylphosphonic acid as heat stabilizers. In addition, a light stabilizer, an antistatic agent, a lubricant, an antioxidant, a release agent, etc. may be added.

[0026]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Each evaluation in this example and the like was performed as follows, and the evaluation results are shown in Tables 1 and 2, respectively. 1. Reaction conversion rate of dicarboxylic acid component in step (1) Distillate amount (g) in step (1) and methanol content concentration (% by weight) in the distillate determined from gas chromatography (GC) ), The reaction conversion rate of the dicarboxylic acid component in the step (1) was calculated from the theoretical amount (g) of methanol. GC is GL Science Co., Ltd., column T
GL Sciences Co., Ltd. connected to C17, GC353
It was measured at. The reaction conversion rate of the dicarboxylic acid component was calculated by the following formula. Reaction conversion rate (mol%) of dicarboxylic acid component in step (1) = [distillate amount of distillate (g) x methanol content concentration in distillate (wt%) / theoretical distillate amount of methanol (g )] × 100

2. Percentage of sublimable diol The oligomer at the end of step (2) was sampled and subjected to gel permeation chromatography (GPC) to determine the concentration of the sublimable diol remaining unreacted in the oligomer solution (weight. %) Was calculated. GPC
Showa Denko KK, two columns KF-801, K
The column temperature was measured at 40 ° C. using GPC system 21, manufactured by Showa Denko KK, to which one F-802.5 and one KF-803L were connected. The eluent is THF 1.0 ml /
It was flowed at a flow rate of min and measured with a differential refractive index detector. Further, the residual ratio of the sublimable diol was calculated from the concentration of the sublimable diol remaining unreacted in the oligomer solution calculated by the above method. Percentage of sublimable diol (% by weight) = [(total charged weight (g) -total distillate weight (g)) × concentration of sublimable diol remaining unreacted in oligomer (weight) %) / Charge of diol having sublimability (g)]
× 100

3. Introduction rate of sublimable diol The ratio of the sublimable diol component to the dicarboxylic acid component in the obtained copolyester resin (copolymerization ratio of sublimable diol) was calculated by ¹ H-NMR measurement. . NM-AL40 manufactured by JEOL Ltd.
0 was measured at 400 MHz. Deuterated chloroform was used as the solvent. The introduction ratio of the sublimable diol forming the copolyester resin to the amount of the sublimable diol added to the reaction system was determined by the following formula. Introduction rate (mol%) of sublimable diol = [Copolymerization rate (mol%) of sublimable diol / Theoretical copolymerization rate (mol%) of sublimable diol]] × 100 The theoretical copolymerization rate of the diol contained was determined by the following formula. Theoretical Copolymerization Ratio (mol%) of Sublimable Diol =
[Amount of SPG charged (mol) / amount of dicarboxylic acid component charged (mol)] × 100

4. Deposition of Sublimable Diol to Polycondensation Device Pressure Reduction Port Pipe After the completion of the polycondensation reaction, the pressure reduction pipe was visually observed and evaluated according to the following evaluation criteria. ◯: No sublimable diol adhered Δ: Sublimable diol adhered in a small amount X: Sublimable diol blocked

Examples 1 to 5 packed column type rectification column, partial condenser, total condenser, cold trap,
A 150-liter (L) polyester production apparatus equipped with a stirring blade, a heating device, and a nitrogen introduction tube was charged with the monomers in the amounts shown in Tables 1 and 2, and manganese acetate tetrahydrate was added to dimethyl terephthalate in an amount of 0. 03 mol% was added and the temperature was raised under normal pressure and nitrogen atmosphere. Distillation of methanol, which is a by-product of the transesterification reaction, started at an internal temperature of 150 to 160 ° C., and methanol was distilled. The temperature was raised to 200 ° C., the transesterification reaction was performed, and the reaction conversion rates of the dicarboxylic acid components were set to the values shown in Tables 1 and 2 (step (1)). Then, add 0.02 mol% of antimony trioxide and 0.06 mol% of trimethyl phosphate to dimethyl terephthalate and add 2
While increasing the temperature to 20 ° C., the pressure was reduced to the pressure shown in Tables 1 and 2, and ethylene glycol was distilled off until the number of moles of the diol component with respect to the number of moles of dimethyl terephthalate became the values shown in Tables 1 and 2. It was ejected and removed (step (2)). Then, the temperature is raised and the pressure is gradually reduced until 270 ° C. and 1
The polycondensation reaction was performed at 00 Pa or less. The reaction product was gradually increased in viscosity, and the reaction was terminated at the time when the melt viscosity became appropriate, and a polyester resin was obtained (step (3)).

Comparative Example 1 The procedure of Example 2 was repeated except that the step (2) was not performed. The results are shown in Table 3. Comparative Example 2 The procedure of Example 3 was repeated except for the number of moles of the diol component with respect to the number of moles of DMT at the end of the step (2). The results are shown in Table 3.
Shown in. Comparative Example 3 The procedure of Example 4 was repeated except for the pressure condition of step (2).
The results are shown in Table 3.

In Tables 1 to 3, dimethyl terephthalate is referred to as "D
MT ", ethylene glycol" EG ", 3,9-
Bis (1,1-dimethyl-2-hydroxyethyl)-
2,4,8,10-Tetraoxaspiro [5.5] undecane was designated as "SPG" and 5-methylol-5-ethyl-
2- (1,1-dimethyl-2-hydroxyethyl)-
1,3-dioxane is abbreviated as "DOG".

Table 1 Example Number Example 1 Example 2 Example 3 Monomer Charge (mol) DMT 293.7 277.3 251.0 EG 572.8 2190.6 426.7 SPG 14.7 27.7 -DOG--75.3 Number of moles of diol component with respect to number of moles of DMT (when charged) 2.0 8.0 2.0 Reaction conversion rate (mol%) of dicarboxylic acid component at the end of step (1) 90 85 90 Pressure at the end of step (2) (kPa) 40 20 80 Number of moles of diol component relative to the number of moles of DMT at the end of step (2) 1.5 2.0 1.7 Sublimability at the end of step (2) Residual rate of diol (% by weight) 3.0 8.0 4.0 Copolymerization rate of diol having sublimability in polyester resin (mol%) 4.9 9.6 29.3 Sublimability in polyester resin Have Theoretical copolymerization rate of diol (mol%) 5.0 10.0 30.0 Introduction rate of diol having a sublimation property (mol%) 98.0 96.0 97.7 Adhesion ○ ○ ○

Table 2 Example No. Example 4 Example 5 Monomer charge (mol) DMT 199.3 117.8 EG 408.5 426.8 SPG 89.7 106.7 Mol of diol component relative to the number of moles of DMT Number (at the time of preparation) 2.5 3.0 Reaction conversion rate (mol%) of dicarboxylic acid component at the end of step (1) 90 93 Pressure at the end of step (2) (kPa) 15 15 At the end of step (2) Number of moles of diol component relative to number of moles of DMT of 1.5 1.3 Residual ratio (% by weight) of diol having sublimability at the end of step (2) 3.0 3.0 Sublimable diol in polyester resin Copolymerization rate (mol%) 44.4 59.0 Theoretical copolymerization rate (mol%) of sublimable diol in polyester resin 45.0 60.0 Introduction rate (mol) of sublimable diol %) 98.7 98.3 Adhesion of diol having sublimation property to the decompression pipe ○ ○

Table 3 Comparative Example Number Comparative Example 1 Comparative Example 2 Comparative Example 3 Monomer Charge (mol) DMT 277.3 251.0 199.3 EG 2190.6 426.7 408.5 SPG 27.7-89. 7 DOG-75.3-mol of diol component relative to the number of DMT (when charged) 8.0 2.0 2.5 Reaction conversion rate (mol%) of dicarboxylic acid component at the end of step (1) 85 90 90 Pressure at the end of step (2) (kPa) -80 100 100 Number of moles of diol component relative to the number of moles of DMT at the end of step (2) 8.0 * 1.9 2.3 Sublimation at the end of step (2) Residual rate (% by weight) of diol having properties of 25.0 * 13.0 17.0 Copolymerization rate (mol%) of diol having sublimability in polyester resin 8.9 28.2 41.7 In polyester resin Theoretical copolymerization rate (mol%) of sublimable diol 10.0 30.0 45.0 Dissipation amount of sublimable diol (mol%) 11.0 6.0 7.3 Sublimable diol Adhesion to decompression pipe △ × × * It is the value at the start of step (3).

[0036]

Industrial Applicability The method for producing a copolyester resin of the present invention uses a dicarboxylic acid and / or an ester-forming derivative thereof, a sublimable diol and a non-sublimable diol as a raw material to prepare a copolyester resin. During production, it becomes possible to obtain the target copolyester resin by improving the reaction conversion rate of the sublimable diol, and it is possible to stabilize the polyester resin production equipment without blocking the piping of the depressurization section. The present invention provides a method for producing a copolyester resin, and the industrial significance of the present invention is great.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shojiro Kuwahara             5-6 Higashi-Hachiman 5-2, Hiratsuka City, Kanagawa Prefecture             Ryogas Chemical Co., Ltd. Hiratsuka Research Center F term (reference) 4J029 AA03 AC02 BA02 BA03 BA04                       BA05 BB03 BB11 BB12 BB13                       BC03 BC05 BD00 BD03 BF00                       BF30 CA01 CA02 CA04 CA05                       CA06 CB03 CB04 CB05 CB06                       CB10 CC03 CC05 CC06 EA00                       KB02 KB12 KC03 KC04 KE02                       KE03 KE15 KJ01

Claims (6)

[Claims] 1. A dicarboxylic acid constituent unit formed from at least a dicarboxylic acid and / or an ester-forming derivative thereof, and a diol constituent unit formed from a diol having sublimability and a diol not having sublimability, and A method for producing a copolyester resin containing 5 to 60 mol% of a unit formed from a sublimable diol in a diol constitutional unit, wherein a diol having no sublimability is used as a raw material to form the copolyester resin. It is added in excess of the amount of non-sublimable diol, and is derived from water and / or the ester-forming derivative until the reaction conversion of the dicarboxylic acid and / or its ester-forming derivative reaches 85 mol% or more. A step (1) of producing an oligomer by distilling alcohol, and then a reaction temperature of 150 to 250 ° C., In addition, the reaction pressure was not higher than the vapor pressure of the non-sublimable diol, and was higher than the vapor pressure of the sublimable diol, and mainly the non-sublimable diol was distilled out and added to the reaction system. A step (2) of transesterifying until the amount of the sublimable diol remaining in the oligomer solution is 10% by weight or less with respect to the amount of the sublimable diol, and further increasing the molecular weight of the oligomer under reduced pressure. A method for producing a copolyester resin, which comprises the step (3) of 2. The sublimable diol is 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,
4,8,10-Tetraoxaspiro [5.5] undecane, and 5-methylol-5-ethyl-2- (1,1-
The method for producing a copolyester resin according to claim 1, which is one or more selected from dimethyl-2-hydroxyethyl) -1,3-dioxane. 3. The method for producing a copolyester resin according to claim 1, wherein the sublimable diol is a diol having a slower reaction rate of transesterification reaction and / or esterification reaction than a diol having no sublimation property. 4. In the step (1), the non-sublimable diol added as a monomer raw material is in a 1.3 to 10-fold molar excess over the amount of the non-sublimable diol forming the copolyester resin. The method for producing a copolyester resin according to claim 1, wherein the copolyester resin is added. 5. The amount of the sublimable diol forming the copolyester at the end of the step (3) is 95 mol% or more with respect to the amount of the sublimable diol added to the reaction system in the step (1). It exists, The manufacturing method of the copolyester resin of any one of Claim 1 thru | or 3 characterized by the above-mentioned. 6. The reaction pressure for producing the oligomer in step (1) is in the range of 40 to 600 kPa, and the reaction pressure for increasing the molecular weight of the oligomer in step (3) is finally 400 Pa or less. It exists, The manufacturing method of the copolyester resin of any one of Claim 1 thru | or 4 characterized by the above-mentioned.