JPH06145316A - Production of modified polybutylene terephthalate resin - Google Patents

Abstract

PURPOSE:To obtain the title resin reduced in the formation of gases in high- temperature service and the sublimation in a dissolved state by adding a small amount of a specified sulfonic acid compound before the completion of the reaction in polycondensing a specified acid component with a specified diol component after esterification. CONSTITUTION:A process for producing a polyester by polycondensing an acid component based on terephthalic acid or its alcohol ester with a diol component based on 1,4-butanediol after esterification or transesterification, which comprises adding 0.001-0.5mol%, based on the above acid-component, at least either of compounds of formulas I and II wherein R<1> is 1-30C alkylene, 2-30C alkenylene or a bivalent group of formula III; R<2> to R<5> and R<6> to R<9> are each H or 1-30C alkyl; and M is tetraalkylphosphonium, tetraalkylammonium, Li, Na, K, Ba or Ca, to the reaction system before the completion of the polycondensation reaction to produce a modified polybutylene terephthalate resin.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a stable modified polybutylene terephthalate resin which produces a small amount of gas such as tetrahydrofuran under high temperature use and a small amount of sublimate during melt processing, and a method for producing the same. The present invention relates to a molded product made of the prepared modified polybutylene terephthalate resin or its composition.

[0002]

2. Description of the Related Art Polybutylene terephthalate (hereinafter sometimes abbreviated as PBT) is a crystalline thermoplastic resin and has mechanical properties, electrical properties, chemical properties, and physical properties. And so on,
It is used as an engineering plastic in a wide range of applications such as automobiles, electric and electronic devices. Further, it is also excellent in aroma retaining property and gas barrier property against water vapor and the like, and is also used in the field of packaging such as containers for foods and cosmetics, packaging films and the like. However, PBT has a problem in molding process that when it is heated in a molten state, gas or sublimate is generated due to decomposition of the resin, which causes voids in the molded product, a mold or a mold. May adhere to rolls and other molding equipment and cause contamination and corrosion. In addition, the resin molding work is not always performed continuously in the actual production process, and the molding work is often performed intermittently.In such a case, the resin is in a molten state for a long time in the molding machine. The problem of gas and sublimate generation is particularly serious because it easily stays, and improvement is desired. Also, molded products using these PBTs generate gases such as tetrahydrofuran even when used at high temperatures, and contaminate or corrode their metal contacts in electric or electronic parts such as relays, switches and connectors. In addition, containers such as foods, beverages, and cosmetics, packaging films, and the like have problems such as transfer of offensive odors to contents and impaired taste. Thus, the reduction of gas generation in molded products is also a highly desired issue.

[0003]

In view of the above demands, the inventors of the present invention have retained the excellent physical properties of PBT resins, and in particular, have a small gas generation amount of tetrahydrofuran and the like when used at high temperatures, and sublimate during melting. As a result of intensive studies to obtain a modified polybutylene terephthalate resin having a small quantity, the present invention has been achieved. That is, the present invention provides a polyester by performing polycondensation from an acid component mainly composed of terephthalic acid or a lower alcohol ester thereof and a diol component mainly composed of 1,4-butanediol through an esterification or transesterification reaction. Before the polycondensation reaction is completed, at least one compound represented by the following general formula (I) or (II) is added to the above acid component in an amount of 0.001 to
A method for producing a modified polybutylene terephthalate resin, characterized in that 0.5 mol% is added, and a molded article comprising the modified PBT resin produced by the production method or a composition thereof.

[0004]

[Chemical 3]

(Wherein R ¹ is an alkylene group having 1 to 30 carbon atoms, an alkenylene group having 2 to 30 carbon atoms or the following general formula (II
It is a divalent group represented by I) (any of them may have a branched structure). R ² , R ³ , R ⁴ and R ⁵ are hydrogen atoms or 1 to 1 carbon atoms.
It is selected from 30 alkyl groups (all of which may have a branched structure) and may be the same or different. M is tetraalkylphosphonium, tetraalkylammonium,
It is a group or element selected from lithium, sodium, potassium, barium, and calcium. )

[0006]

[Chemical 4]

(However, R ⁶ , R ⁷ , R ⁸ and R ⁹ are selected by a hydrogen atom or an alkyl group having 1 to 30 carbon atoms and may be the same or different.) Modified polybutylene of the present invention The terephthalate resin is mainly composed of a butylene terephthalate unit obtained from an acid component mainly composed of terephthalic acid or a lower alcohol ester thereof and a diol component mainly composed of 1,4-butanediol. Includes copolyesters.

When preparing the copolyester,
Acid constituent component As a comonomer, in addition to the main constituent acid component, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid It is possible to use one or more kinds of conventionally known bifunctional carboxylic acids such as acids or dimethyl esters thereof or lower alcohol esters thereof. Further, in addition to the main constituent diol component as a diol constituent comonomer, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, neopentyl glycol, 1,6-hexanediol, 1,10-decanediol, 1, 4-cyclohexanediol, p-xylidene glycol, hydroquinone alkylene oxide adduct, 2,2-bis (4-hydroxyphenyl) propane alkylene oxide adduct, bis (4-hydroxyphenyl) sulfone alkylene oxide adduct, It is possible to use one or more kinds of conventionally known bifunctional diols such as an ethylene oxide adduct of 2,6-dihydroxynaphthalene. Further, a halogen-substituted product of the above substances may be used as a comonomer to impart flame retardancy. In addition, trifunctional or more polyfunctional compounds such as trimethyl trimesate, trimethyl trimellitate, trimethylolpropane and pentaerythritol, stearyl alcohol, methyl o-benzoyl benzoate, monofunctional compounds such as epoxy compounds,
It is also possible to use a small amount of a hydroxycarboxylic acid derivative such as methyl p-hydroxyethoxybenzenecarboxylate, a polypropylene glycol, a polyalkylene glycol such as polytetrahydrofuran, or to use in combination with the above-mentioned copolymerization component. The amount of these copolymerization components introduced is
30 mol% based on the total repeating ester units
It is below, and particularly preferably 20 mol% or below.

The modified polybutylene terephthalate resin according to the present invention is produced by adding at least one of the compounds represented by the general formula (I) or (II) to 0.001 to 0.5 of the acid component before completion of the polycondensation reaction. It is characterized by adding mol%. Specific examples of the compound represented by the general formula (I) include sulfoacetic acid, methyl sulfoacetate, 2-sulfodecanoic acid, methyl 2-sulfodecanoate, 2-sulfostearic acid, methyl 2-sulfostearate and 2-sulfo. Palmitic acid, methyl 2-sulfopalmitate, 2
-Sulfolauric acid, methyl 2-sulfolaurate, 2
-Sulfobehenic acid, methyl 2-sulfobehenate, 2-sulfomontanic acid, methyl 2-sulfomontanate, sulfosuccinic acid, dimethyl sulfosuccinate, di-2-ethylhexyl sulfosuccinate, monomethyl sulfosuccinate,
α, α'-diethyl-α-sulfosuccinic acid, α, α'-
Dimethyl diethyl-α-sulfosuccinate or α, α'-
Examples include tetrabutylphosphonium salts such as di-2-ethylhexyl diethyl-α-sulfosuccinate, tetrabutylammonium salts, lithium salts, sodium salts, potassium salts, barium salts or calcium salts. Specific examples of the compound represented by the general formula (II) include tetrabutylphosphonium salts such as sulfosuccinic anhydride, α, α′-diethyl-α-sulfosuccinic anhydride, tetrabutylammonium salt and lithium salt. , Sodium salt, potassium salt, barium salt, calcium salt and the like. The aromatic sulfonic acid compound represented by the general formula (I) or (II) needs to be added at any time from the step of preparing a monomer to the completion of the polycondensation reaction, and may be added several times to any step. It is also possible to add them separately. In particular, when the aromatic sulfonic acid compound represented by the general formula (I) or (II) is added, the polycondensation reaction is carried out through the esterification or transesterification reaction between the acid component and the diol component in the raw material monomer. The pre-addition to or prior to the completion of the esterification or transesterification reaction is preferred.
That is, it is added to the monomer before the addition of the reaction catalyst, or when the lower alcohol ester of carboxylic acid is used as the acid component as a raw material, the lower alcohol produced by the transesterification reaction with the diol component is distilled out of the reaction system. Before the amount reaches 90 mol% of the theoretical amount of distillate, and when carboxylic acid is used as a raw material as the acid component, the amount of distillate of water generated by the esterification reaction with the diol component out of the reaction system is theoretical. It is preferable to add the compound to the reaction system before reaching 90 mol% of the distillate amount. That is, the effect of reducing the amount of gas such as tetrahydrofuran generated when the molded product is used at high temperature and the amount of the sublimate during melt processing is more remarkable as described above, when the aromatic sulfonic acid compound is added in the preceding step in the polyester forming reaction process. Can be obtained. On the other hand, if the polymer pellets once polymerized are mixed by using an extruder or the like, the effect is reduced, which is not preferable. In addition, upon addition, it is preferable to add it to the system as a liquid which is dissolved or suspended in 1,4-butanediol or the like in advance. The amount of the above-mentioned aromatic sulfonic acid compound added is 0.001 to 0.5 mol% based on the acid component monomer, alone or in combination of two or more. A particularly preferred amount of addition is 0.01 to 0.3 mol%. When the addition amount is less than 0.001 mol%, the effect of reducing the amount of gas such as tetrahydrofuran and the amount of sublimate at the time of melting when the molded product is used at high temperature is small, and when it is more than 0.5 mol%, the above effect is obtained. In addition to reaching equilibrium, it remains insoluble and remains as a minute foreign substance in the polymerized product.
It is not preferable because it causes poor appearance of the molded product and deterioration of mechanical strength.

In the method of the present invention, when the lower alcohol ester of terephthalic acid is used as the acid component, the transesterification reaction is carried out by mixing the lower alcohol ester of terephthalic acid and 1,4-butanediol in a molar ratio of 1: 1 to 1: 2. As normal pressure. Examples of the catalyst for obtaining a practical reaction rate include titanium compounds, tin compounds, lead oxide, lead acetate, zinc acetate, zinc oxide, manganese acetate and the like. Among them, organic titanate compounds, titanium tetrachloride compounds and these A hydrolyzate or an alcoholysis, a tin oxide, a tin acetate, an organic tin compound and the like are preferable. Specifically, tetrabutyl titanate, tetrapropyl titanate, tetraethyl titanate, tetramethyl titanate and their hydrolysates, hydrolysates of titanium tetrachloride and titanium sulfate, titanium fluoride potassium, titanium fluoride fluoride, titanium fluoride cobalt and the like. Inorganic titanium compounds, titanium oxalates, titanium compounds conventionally known as polyester production catalysts such as potassium oxalate, and / or dibutyltin oxide, dibutyltin acetate, dioctyltin diacetate, diphenyltin dilauryl mercaptide, polydibutyltin sebacate, dibutyltin. Ethylene glycolate, dioctyl tin thiosalicylate, diphenyl tin benzene sulfonate,
As a polyester production catalyst such as dimethyltin-p-toluenesulfonate, there is a conventionally known tin compound. Particularly preferred are tetrabutyl titanate, tetrapropyl titanate, hydrolyzate of titanium tetrachloride, dibutyltin oxide, dibutyltin acetate, dioctyltin diacetate and the like. The amount of these catalysts to be used is preferably 10 to 1200 as titanium and tin (total in the case of mixed system) when titanium compound system, tin compound system and mixed system thereof are taken as an example.
It is preferable to add ppm (relative to the polymer), particularly preferably 30 to 1000 ppm (relative to the polymer), and it is also possible to add it several times during the reaction if necessary. After this, the reaction temperature is
It is possible to raise the temperature to 230 ° C or lower while continuously removing lower alcohols such as methanol.

The esterification reaction using terephthalic acid as an acid component as a main raw material is carried out at a ratio of 1 to 5 mol of 1,4-butanediol to 1 mol of terephthalic acid under normal pressure or under pressure, and It is carried out while adding an esterification reaction catalyst such as a titanium compound or a tin compound to remove continuously produced water, and the catalyst can be divided into several times during the reaction, if necessary. After this, the reaction temperature is 250 ℃
It is possible to increase to the following.

In the polycondensation reaction, the product obtained by the above transesterification reaction or esterification reaction is treated at 190 to 270 ° C.
Then, the reaction system is depressurized and the excess 1,4-butanediol and reaction by-products are continuously removed, and melt polymerization is carried out until the desired degree of polymerization is obtained. As a catalyst for obtaining a practical reaction rate in the polycondensation reaction, the catalyst used in the above transesterification reaction or esterification reaction can be used as it is, and in order to improve the speed of the polycondensation reaction, polycondensation It is also possible to add one or more of these before the start of the reaction. It is also possible to add a conventionally known stabilizer such as a sterically hindered phenol or a phosphorus compound at the monomer preparation stage or the polymerization stage. Incidentally, with respect to the polycondensation reaction rate, the aromatic sulfonic acid compound added in the present invention does not adversely affect the addition amount specified in the present invention,
It does not hinder the polycondensation reaction.

The modified polybutylene terephthalate of the present invention obtained by melt polymerization is 25% in orthochlorophenol.
It has an inherent viscosity at 0.5 ° C. of a value of about 0.5 to 1.2, which is then solidified by cooling and crushed or pelletized. Further, when a high degree of polymerization is required, it is possible to shift to solid phase polymerization depending on the application. Solid phase polymerization is usually carried out by a known method, and the desired degree of polymerization can be appropriately adjusted by the residence time, processing temperature and the like.

The modified polybutylene terephthalate resin of the present invention may optionally be supplemented with one or more other thermoplastic resins, additives, organic fillers, inorganic fillers, etc. during or after polymerization. It can also be used as a composition in which it is added and compounded. Here, as the thermoplastic resin, a polyester-based resin other than the polyester elastomer and the present invention, a polyolefin-based resin, a polystyrene-based resin,
Examples include polyamide resins, polycarbonates, polyacetals, polyarylene oxides, polyarylene sulfides, and fluororesins. Further, as additives, stabilizers such as conventionally known ultraviolet absorbers and antioxidants, antistatic agents, flame retardants, flame retardant aids, colorants such as dyes and pigments,
Lubricants, plasticizers, lubricants, release agents, crystal nucleating agents and the like are exemplified. Further, as the inorganic filler, glass fiber, milled glass fiber, glass beads, glass flakes, silica, alumina fiber, zirconia fiber, potassium titanate fiber, carbon fiber, carbon black, graphite, calcium silicate, aluminum silicate, kaolin, Silicates such as talc and clay, metal oxides such as iron oxide, titanium oxide, zinc oxide, antimony oxide and alumina, carbonates and sulfates of metals such as calcium, magnesium and zinc, and further silicon carbide and silicon nitride, Examples thereof include boron nitride, and examples of the organic filler include high melting point aromatic polyester fibers, liquid crystalline polyester fibers, aromatic polyamide fibers, fluororesin fibers, and polyimide fibers. When used as a molded article for electric / electronic parts or automobile parts, flame retardancy is often required depending on the environment of use, and it is often essential to add a flame retardant or flame retardant aid. As the flame retardant, a known halogen-containing compound flame retardant such as brominated polycarbonate, brominated epoxy compound, brominated diphenyl, brominated diphenyl ether can be used,
As a flame retardant aid, in addition to antimony compounds such as antimony trioxide, antimony pentoxide, and antimony halide,
Metal compounds containing zinc, bismuth, clay silicates such as magnesium hydroxide or asbestos, and the like can be used.
Further, it is preferable to use an appropriate amount of a stabilizer such as an antioxidant because the effects of the present invention are further improved.

The modified PBT resin and the composition thereof of the present invention can be applied with various molding methods such as injection molding, extrusion molding, blow molding, compression molding and vacuum molding, and various molding parts, films and sheets. It is processed into various types and used for various purposes.

[0016]

The modified polybutylene terephthalate resin produced according to the present invention has excellent physical properties, in particular, stability during melt molding is excellent, a small amount of decomposed sublimates is generated, and high temperature use Generates little amount of gas such as tetrahydrofuran, does not cause contamination or corrosion of metal parts as electric or electronic parts such as relays, switches and connectors, and can also be used as food and cosmetic containers, packaging films, etc. It is suitable because it does not become contaminated.

[0017]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
The characteristics of the produced resin were evaluated as follows. (1) Measurement of evolved gas and its production amount An ASTM No. 1 tensile test piece was prepared under a certain condition by an injection molding machine, and this was crushed to a certain particle size to obtain a sample.
After taking 5 g of a sample and leaving it in a 20 ml head space at 140 ° C. for 2 hours, the generated gas was measured by gas chromatography under the following conditions. The weight of the generated gas is shown in ppm with respect to the weight of the sample. Equipment: Yokogawa Hewlett-Packard HP58
90A column; HR-1701, 0.32mm diameter x 30m Column temperature: 50 ° C (1 minute) → 5 ° C / min → 250 ° C
(1 minute) Detector; FID (2) Melt heating loss measurement Using 10 mg of sample cut out from pellets with a thermogravimetric analyzer (Perkin Elmer, TGA-7), melt heating at 260 ° C in a nitrogen flow atmosphere and melting The rate of weight loss in 10 minutes from 5 minutes to 15 minutes was measured. (3) Mechanical strength evaluation Izod impact strength (notch side) was measured according to ASTM D 256.

Examples 1 to 3, Comparative Examples 1 to 2 After thoroughly replacing the reactor equipped with a stirrer and a distillation column with nitrogen, 246 parts by weight of dimethyl terephthalate (DMT), 1,4
-Butanediol (1,4 BD) 145 parts by weight, the following (Ia) formula compound in the amounts shown in Table 1, and 0.14 parts by weight of titanium tetrabutoxide as a catalyst were charged, the transesterification reaction was carried out, and the temperature was gradually raised. The temperature was raised and the by-product methanol was distilled off. When the amount of distilled methanol exceeded 88% by weight of the theoretical amount, the temperature of the reactant was raised to 200 ° C., which was then transferred to another reactor, and the pressure was reduced to 0.5 torr in 1 hour.
At the same time, raise the reaction temperature to 250 ° C, and in this state 1.5
After continuing stirring for a period of time, the melt was extruded from the outlet as a strand, the strand was cooled with water, and adhering water was removed by passing under hot air to obtain a pelletized modified PBT resin.

[0019]

[Chemical 5]

The intrinsic viscosity of the obtained polyester was measured in orthochlorophenol at 25 ° C., and the above characteristics were evaluated. Gases such as 1-butene, tetrahydrofuran and 3-buten-1-ol were observed as the generated gas. The results are shown in Table 1. For comparison, when the aromatic sulfonic acid compound is not used at all (Comparative Example 1), and I
When the addition amount of -a was out of the range of the present invention (Comparative Example 2), the same evaluation was performed. The results are also shown in Table 1. In addition, white fine particles were observed in the polyester obtained in Comparative Example 2.

Examples 4 to 7 and Comparative Examples 3 to 4 Instead of the (Ia) formula compound in Example 2, the following (Ib), (Ic), (II-d) and (II) were used. -E)
A predetermined amount of the compound represented by the formula (0.1 mol%;
T) Melt polymerization was conducted in the same manner as in Example 2 except that the modified PBT resin was obtained. The results are shown in Table 2. For comparison, the same evaluation was performed when the following compounds (I′-f) and (I′-g) different from the structure represented by the general formula (I) or (II) were used. The results are also shown in Table 2.

[0022]

[Chemical 6]

Examples 8 to 9 In accordance with the conditions shown in Example 2, the same evaluation results are shown in Table 3 by changing the addition timing of the compound (Ia).

Examples 10 to 11 and Comparative Examples 5 to 6 When a part (10 mol%) of DMT was dimethyl isophthalate (DMI) as a copolymerization component (Example 10),
Example 2 When a part (2.5 mol%) of 1,4BD was 2,2-bis [3,5-dibromo-4- (2-hydroxyethoxy) phenyl] propane (BrEBPA) (Example 11) Melt polymerization was carried out in the same manner as above to obtain a copolyester. The results are shown in Table 4. For comparison, when the aromatic sulfonic acid compound was not used at all (Comparative Example 5,
6) was evaluated by the same method. The results are also shown in Table 4.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 4, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

The modified polybutylene terephthalate resin according to the present invention is produced by adding at least one of the compounds represented by the general formula (I) or (II) to 0.001 to 0.5 of the acid component before completion of the polycondensation reaction. It is characterized by adding mol%. Specific examples of the compound represented by the general formula (I) include sulfoacetic acid, methyl sulfoacetate, 2-sulfodecanoic acid, methyl 2-sulfodecanoate, 2-sulfostearic acid, methyl 2-sulfostearate and 2-sulfo. Palmitic acid, methyl 2-sulfopalmitate, 2
-Sulfolauric acid, methyl 2-sulfolaurate, 2
-Sulfobehenic acid, methyl 2-sulfobehenate, 2-sulfomontanic acid, methyl 2-sulfomontanate, sulfosuccinic acid, dimethyl sulfosuccinate, di-2-ethylhexyl sulfosuccinate, monomethyl sulfosuccinate,
α, α'-diethyl-α-sulfosuccinic acid, α, α'-
Dimethyl diethyl-α-sulfosuccinate or α, α'-
Examples include tetrabutylphosphonium salts such as di-2-ethylhexyl diethyl-α-sulfosuccinate, tetrabutylammonium salts, lithium salts, sodium salts, potassium salts, barium salts or calcium salts. Specific examples of the compound represented by the general formula (II) include tetrabutylphosphonium salts such as sulfosuccinic anhydride, α, α′-diethyl-α-sulfosuccinic anhydride, tetrabutylammonium salt and lithium salt. , Sodium salt, potassium salt, barium salt, calcium salt and the like. The sulfonic acid compound represented by the general formula (I) or (II) needs to be added at any time from the monomer preparation stage to the completion of the polycondensation reaction, and the sulfonic acid compound may be divided into several stages at any stage. It is also possible to add. In particular, the addition timing of the sulfonic acid compound represented by the general formula (I) or (II) is such that the polycondensation reaction is performed through the esterification or transesterification reaction of the acid component and the diol component with each other in the raw material monomer in advance. Preference is given to the stage before addition or before the esterification or transesterification reaction is substantially complete. That is, it is added to the monomer before the addition of the reaction catalyst, or when the lower alcohol ester of carboxylic acid is used as the acid component as a raw material, the lower alcohol produced by the transesterification reaction with the diol component is distilled out of the reaction system. 90 is the theoretical distillate
Before reaching the mol%, or when using carboxylic acid as the acid component as a raw material, the amount of water produced by the esterification reaction with the diol component outside the reaction system reaches 90 mol% of the theoretical amount. It is preferred to add the compound to the reaction system before reaching. That is, the effect of reducing the amount of gas such as tetrahydrofuran generated when the molded product is used at high temperature and the amount of sublimate during melt processing is as remarkable as the addition of the sulfonic acid compound in the preceding step in the polyester formation reaction process, as described above. Is obtained. On the other hand, if the polymer pellets once polymerized are mixed by using an extruder or the like, the effect is reduced, which is not preferable. Also, before adding 1,4
-As a solution dissolved or suspended in butanediol or the like,
It is preferably added to the system. The addition amount of the above-mentioned sulfonic acid compound is 0.001 to 0.5 mol% with respect to the acid component monomer alone or in combination of two or more kinds. A particularly preferred amount of addition is 0.01 to 0.3 mol%. Addition amount is 0.0
If it is less than 01 mol%, the effect of reducing the amount of gas such as tetrahydrofuran generated in the use of the molded product at high temperature and the amount of sublimate at the time of melting is small, and if it is more than 0.5 mol%, the above effects reach equilibrium. However, it remains undissolved and remains as minute foreign matter in the polymerized product, resulting in poor appearance of the molded product, deterioration of mechanical strength, etc., which is not preferable.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

In the polycondensation reaction, the product obtained by the above transesterification reaction or esterification reaction is treated at 190 to 270 ° C.
Then, the reaction system is depressurized and the excess 1,4-butanediol and reaction by-products are continuously removed, and melt polymerization is carried out until the desired degree of polymerization is obtained. As a catalyst for obtaining a practical reaction rate in the polycondensation reaction, the catalyst used in the above transesterification reaction or esterification reaction can be used as it is, and in order to improve the speed of the polycondensation reaction, polycondensation It is also possible to add one or more of these before the start of the reaction. It is also possible to add a conventionally known stabilizer such as a sterically hindered phenol or a phosphorus compound at the monomer preparation stage or the polymerization stage. The sulfonic acid compound added in the present invention has no adverse effect on the polycondensation reaction rate at the addition amount specified in the present invention and does not hinder the polycondensation reaction at all.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

The intrinsic viscosity of the obtained polyester was measured in orthochlorophenol at 25 ° C., and the above characteristics were evaluated. Gases such as 1-butene, tetrahydrofuran and 3-buten-1-ol were observed as the generated gas. The results are shown in Table 1. For comparison, the case where the sulfonic acid compound was not used at all (Comparative Example 1) and the case where the amount of Ia added was outside the range of the present invention (Comparative Example 2) were evaluated by the same method. The results are also shown in Table 1. still,
White fine particles were observed in the polyester obtained in Comparative Example 2.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

[0022]

[Chemical 6]

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

Examples 10 to 11 and Comparative Examples 5 to 6 When a part (10 mol%) of DMT was dimethyl isophthalate (DMI) as a copolymerization component (Example 10),
Example 2 When a part (2.5 mol%) of 1,4BD was 2,2-bis [3,5-dibromo-4- (2-hydroxyethoxy) phenyl] propane (BrEBPA) (Example 11) Melt polymerization was carried out in the same manner as above to obtain a copolyester. The results are shown in Table 4. For comparison, when the sulfonic acid compound was not used at all (Comparative Examples 5 and 6), the same method was used for evaluation. The results are also shown in Table 4.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

[0025]

[Table 1]

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

[0026]

[Table 2]

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

[0028]

[Table 3]

Claims (3)

[Claims] 1. A polyester is obtained by polycondensing an acid component mainly composed of terephthalic acid or a lower alcohol ester thereof and a diol component mainly composed of 1,4-butanediol through an esterification or transesterification reaction. At the time of production, before the polycondensation reaction is completed, at least one of the compounds represented by the following general formula (I) or (II) is added in an amount of 0.001 to 0.5 mol% with respect to the above acid component. Method for producing butylene terephthalate resin. [Chemical 1] (However, R ¹ is an alkylene group having 1 to 30 carbon atoms and 2 to 2 carbon atoms.
30 alkenylene groups or 2 represented by the following general formula (III)
It is a valence group. R ² , R ³ , R ⁴ and R ⁵ are hydrogen atoms or have 1 carbon atom
Selected from alkyl groups of up to 30 and may be the same or different. M is a group or element selected from tetraalkylphosphonium, tetraalkylammonium, lithium, sodium, potassium, barium, and calcium. ) [Chemical 2] (However, R ⁶ , R ⁷ , R ⁸ and R ⁹ are selected from a hydrogen atom or an alkyl group having 1 to 30 carbon atoms and may be the same or different.) 2. The addition timing of the compound represented by the general formula (I) or (II) is such that the amount of water produced by the esterification reaction outside the reaction system or the reaction of the lower alcohol produced by the transesterification reaction. The amount of distillate outside the system is 90, which is the theoretical amount.
The method for producing a modified polybutylene terephthalate resin according to claim 1, which is before the mol% is reached. 3. A molded article comprising a modified polybutylene terephthalate resin produced by the production method according to claim 1 or 2, or a composition thereof.