JP5549268B2 - Method for producing crystalline polyester resin - Google Patents

Description

The present invention relates to a manufacturing method excellent polyester resins crystallinity and transparency.

As a technique for improving the crystallinity of a polyester resin, a method using an additive is generally used, but a manufacturing method that satisfies all of these requirements has not been established yet, such as high crystallinity, high transparency, and excellent cost performance. Patent Document 1 discloses a technique for improving crystallinity by forming an internal particle by adding an organic metal salt as a crystal nucleating agent during a transesterification reaction. In this method, the size and generation of the internal particle are disclosed. It is difficult to control the amount, and there is a problem that the transparency of the resin is impaired due to generation of coarse foreign matters. Patent Document 2 discloses a technique in which a magnesium compound and a specific phosphorus compound are added to precipitate fine particles. However, a polyester other than polyethylene terephthalate does not provide a crystallization effect and is difficult to produce in a manufacturing process. There is a problem that production control is difficult because fine particles are precipitated during the condensation reaction.

  In addition, the method of adding inorganic particles such as talc and alumina disclosed in Patent Document 3 can be expected to increase the temperature-falling crystallization temperature (Tc) and improve the crystallization. However, the crystallization effect depends on the amount of particles added, and therefore there is a problem that the transparency is greatly lowered in order to obtain high crystallinity. Patent Document 4 discloses a technique of kneading an organic metal salt such as a carboxylic acid metal salt or a sulfonic acid metal salt into a polyester resin. With this technology, a high crystallization effect can be obtained. However, since it is necessary to take a long kneading time for fine dispersion, the decrease in IV (intrinsic viscosity) and the color tone during kneading are remarkable, and the quality is deteriorated. There is an inviting problem.

Japanese Patent Laid-Open No. 15-55444 JP-A-5-339476 JP-A-60-20954 JP-A-16-515539

  The present invention solves the above-mentioned problems of the prior art by a novel polyester polymerization method in which a sodium salt is efficiently reacted at the end of a polyester chain by adding a sodium salt during the polycondensation reaction of a saturated polyester resin. And providing a polyester resin having high crystallinity and high transparency.

  In order to solve the above problems, the present invention has the following features.

( 1 ) In a method of producing a polyester by subjecting an ester-forming derivative component of a dicarboxylic acid and a diol component to a transesterification reaction or an esterification reaction, followed by a polycondensation reaction, the polymer IV (inherent viscosity) A method for producing a crystalline polyester resin, comprising adding a long-chain aliphatic carboxylic acid sodium salt having 18 or more carbon atoms during a period from 0.4 to 0.4 until the end of the polycondensation reaction.

  By the method of the present invention, it is possible to obtain a polyester resin having high crystallinity and high transparency, and by using this, an improvement in injection moldability, an improvement in heat formability, and a mold release compared with existing crystalline polyester It is possible to improve performance and reduce manufacturing costs.

(a) is sectional drawing of the metal mold | die used for shaping. (b) is a perspective view of the metal mold | die used for shaping. (C) is a shaped molded product. (1) to (3) are heat shaping flows.

  The present invention is described in detail below.

  The present invention achieves both high crystallinity and high transparency by using sodium salt as the crystal nucleating agent and controlling the state of sodium in the resin.

    In the polyester resin of the present invention, (1) the sodium content contained in the resin is 50 ppm or more and 800 ppm or less, and (2) the change rate of the sodium content that is changed by the centrifugation operation is 75. %, And (3) the solution haze of the resin must satisfy the following three items: 7% or less.

    The sodium content of the polyester resin of the present invention needs to be 50 ppm or more and 800 ppm or less, preferably 100 ppm or more and 400 ppm or less. Sodium is added as a metal salt and may have an effect as a transesterification catalyst, but acts mainly as an effect of a crystal nucleating agent. If the sodium content in the polyester resin is less than this range, the crystallization effect is not sufficient, and if it is more than this range, there is a possibility that the transparency and color tone will deteriorate due to the generation of foreign substances.

    Here, the foreign substance in the present invention is a precipitate obtained by dissolving 10 g of a polyester resin in 100 g of orthochlorophenol at 150 ° C. for 3 hours, and separating with a high-speed centrifuge (28425G, 1 hour, 30 ° C.). The rate of change in sodium content was calculated by comparing the polyester collected by reprecipitation by adding 200 ml of acetone to the supernatant solution (75 ml) after the separation operation and the polyester content not subjected to the separation operation. .

Sodium amount change rate (%) = (Na1-Na2) / Na1 × 100
Here, Na1 is the amount of sodium (ppm) contained in the polyester resin before the separation operation, and Na2 is the amount of sodium (ppm) contained in the polyester resin after the centrifugation operation.

    In the polyester resin of the present invention, it is necessary that the rate of change in sodium content that changes by centrifugation is 75% or less, and preferably 70% or less. A small rate of change in sodium content means that the amount of sodium-containing material removed as foreign matter is small. Therefore, the crystal nucleating agent and particles containing sodium are further refined and dispersed in the polyester resin, and since the affinity with the polyester resin is high, the generation of foreign matter and the decrease in transparency are suppressed. . If it is larger than this range, the solution haze value of the polyester resin increases, the amount of foreign matter generated increases, and the transparency decreases.

    Sodium present in the polyester is divided into a foreign substance or a particulate component separated by a centrifugal separation operation and a component that is not separated and has an affinity for the polyester. Crystallization of polyester is considered to be that the crystal grows epitaxially on foreign matter and particleized components as well as particles of talc, etc. It was found that the sodium component therein also has a great effect on promoting crystallization.

    The polyester resin of the present invention preferably has a sodium content of 40 ppm or more, more preferably 60 ppm or more after the above centrifugation operation. Having a high sodium content after the centrifugation operation means that the sodium-containing component is more compatible with the polyester resin and is not removed as a foreign substance by the centrifugation operation. The sodium component having affinity for the polyester resin is a polyester in which the carboxyl terminal is sodium-ized, and this component exhibits a crystallization effect. Therefore, it is preferable to contain more sodium-terminated polyester, and sufficient crystallization can be obtained if the sodium content after centrifugation is within the scope of the present invention. If it is less than this range, the crystallinity will be insufficient. Moreover, since saying that there is much sodium amount removed as a foreign material is saying that the amount of foreign materials is large, the amount of foreign materials in a polyester resin is large and transparency is falling.

    The crystalline polyester resin in the present invention is a polyester resin having a heat of crystal fusion (ΔHm) of 0.3 J / g or more. This ΔHm is a value calculated from a temperature rise curve of differential scanning calorimetry (DSC).

    The polyester resin of the present invention is characterized by containing a crystal nucleating agent. By containing the crystal nucleating agent, excellent crystallization characteristics are imparted to the polyester resin. By using a sodium salt as a crystal nucleating agent, the carboxyl terminal in the polyester resin is sodiumized. The polyester chain with the terminal sodium is functioning as a true crystal nucleating agent to improve crystallinity.

    The purpose of the present invention is to improve the crystallinity of the polyester resin, and the temperature difference ΔTcg (Tcc−Tg) between the temperature rising crystallization temperature (Tcc) and the glass transition temperature (Tg) is used as a measure of crystallinity. In comparison of the same composition polymer, the lower the ΔTcg, the easier it is to crystallize. The crystal nucleating agent has an effect of reducing ΔTcg, and the crystallization effect can be adjusted by the kind and the addition amount. In addition, since the number of crystal nuclei increases due to the presence of the crystal nucleating agent, the size of the crystals to be generated becomes small and uniform, and whitening suppression during microcrystallization, that is, improvement in transparency can be expected.

    Tcc and Tg at this time are values calculated from a temperature rise curve of differential scanning calorimetry (DSC) of the substantially amorphous polyester resin. Specifically, after a molten state is obtained in the first cycle of DSC measurement, it is immediately cooled using liquid nitrogen to obtain an amorphous solid, and then measurement is carried out in the second cycle. Here, the reason why liquid nitrogen is used for cooling is to suppress the progress of crystallization between the cooling in the first cycle and the second cycle. If the cooling rate is slow, crystallization proceeds, and accurate values cannot be calculated for each measured value of temperature and heat quantity.

    The polyester resin of the present invention preferably has a ΔTcg of 90 ° C. or lower, and no particular lower limit is provided. More preferably, it is 70 degrees C or less. When ΔTcg is within this range, it is easy to crystallize during injection molding or heat shaping, and the molding cycle can be shortened. When ΔTcg is larger than this, crystallization does not proceed sufficiently, and heat resistance, shape stability, and molding cycle are lowered.

    Since the polyester resin of the present invention has good crystallinity, it is suitable for various thermoforming applications. For example, in the case of heat forming and injection molding, the glass transition temperature (Tg) is high, the melting point (Tm) is low, and the heat of crystal melting (ΔHm) is high due to moldability, heat resistance after molding, and shape stability. Larger is preferred. By adding a crystal nucleating agent, a crystallization effect is imparted, and injection moldability, heat formability, and release properties are excellent. Among them, since the heat formability is particularly good, it is suitable for heat forming by heat imprinting. Thermal imprinting is a technique that has recently been used as a technique for shaping microstructures. A thermoplastic resin is heated at a temperature of not less than Tg and less than Tm, and a mold having an uneven pattern is pressed against the thermoplastic resin. It is a technology that transfers the shape and is also used for forming in the μm order.

    It is desirable that the resin to be heat-shaped is uniform and low in crystallinity without stretch distortion before heat-forming, and that the heat-stabilized shape is crystallized after heat-forming. It is preferable from the point. When used in optical applications, it is desirable that crystallization should be such that transparency is not hindered. By increasing Tg, the thermal stability is improved, and in combination with crystallization, more excellent thermal stability is expressed.

    In order to achieve both the amorphousness before heat shaping and the transparency after heat shaping, the resin needs to be crystalline. In addition, it is necessary to perform heat treatment at a temperature near the melting point of the polyester resin before heat forming, remelt the film surface layer, and make the orientation uniform. In the heat treatment, the lower the melting point, the easier the homogenization occurs. Therefore, the polyester resin of the present invention preferably has a low melting point.

    In the heat imprint molded article, it is preferable to laminate the shaping layer resin on the surface layer of the base material having a higher melting point in order to improve the film forming property. When lamination is performed, the melting point of the base material (here, the melting point of the resin constituting the base material is Tm1) or less, and the melting point of the shaping layer resin (here, the melting point of the shaping layer resin) Is preferably heat treated at a temperature equal to or higher than Tm2. That is, the heat treatment temperature (Ta) is preferably Tm1 ≧ Ta ≧ Tm2.

    Therefore, when polyethylene terephthalate having a melting point of 260 ° C. is used as the base material and the polyester resin of the present invention is used for the shaping layer, the heat shaping property, the affinity between layers, and the low cost, The polyester resin preferably has a melting point of 230 ° C. or lower. Moreover, not only the heat treatment step but also the mold following ability and the like are good when the melting point is low even at the time of heat forming. When the melting point is higher than 230 ° C., homogenization and low crystallization during heat treatment are insufficient, and heat formability is deteriorated. There is no particular lower limit, but if it is lower than 130 ° C., Tg is also lowered, which is not preferable.

    The polyester resin of the present invention preferably has a Tg of 83 ° C. or higher. More preferably, it is 85 degreeC or more. By setting it as this range, heat resistance and molding stability become favorable. If it is lower than this range, the heat resistance and shape stability will decrease. An upper limit is not particularly provided, but if it is higher than 150 ° C., it is not preferable because the heat formability is lowered.

    Furthermore, the polyester resin of the present invention preferably has a ΔHm of 10 J / g or more, more preferably 20 J / g or more. If it is smaller than this, crystallization is insufficient and thermal stability is lowered. There is no particular upper limit, but if it is 40 J / g or more, it may be crystallized too much, resulting in poor molding.

    The polyester resin of the present invention preferably has a solution haze of 7% or less, more preferably 5% or less, and still more preferably 3% or less. Solution haze is the turbidity measured by dissolving 2 g of polyester resin in 20 ml of phenol / 1,1,2,2-tetrachloroethane 3/2 (volume ratio) mixed solution and using a cell with an optical path length of 20 mm. It is a numerical value that represents. If it is larger than this range, it is not preferable because the transparency is lowered, and there is a possibility that the transmitted light amount of the molded product is lowered due to the lowered transparency.

    The polyester resin of the present invention is preferably a homopolymer in which the dicarboxylic acid ester-forming derivative component and the diol component are each composed of one component, and either the dicarboxylic acid ester-forming derivative component, the diol component, or both are composed of a plurality of polymers. Even a copolyester is preferred. Among them, dicarboxylic acid ester-forming derivative components include those having a terephthalic acid residue such as dimethyl terephthalate (DMT), those having a naphthalenedicarboxylic acid residue such as dimethyl 2,6-naphthalenedicarboxylate (DMN), and dimethyl isophthalate. It is selected from at least one of those having an isophthalic acid residue such as (DMI), and the diol component is preferably ethylene glycol from the viewpoint of cost and polymerizability.

    The polyester resin of the present invention preferably has an IV (inherent viscosity) of 0.55 or more and 0.70 or less. More preferably, it is 0.57 or more and 0.65 or less. If it is larger than this range, the injection moldability and heat formability are lowered, and if it is smaller than this range, the heat resistance is lowered.

    The polyester resin of the present invention has a surface forming agent, processability improver, antioxidant, ultraviolet absorber, infrared absorber, light stabilizer, and antistatic agent in addition to the above nucleating agent as long as crystallinity and transparency are not impaired. Additives such as lubricants, antiblocking agents, soft particles, plasticizers, antifogging agents, colorants, dispersants and the like can be added. Moreover, as long as crystallinity and transparency are not impaired, an alloy with another resin may be used. Examples of the alloy component include various acrylics, polyesters, polycarbonates, cyclic olefins, and the like, and it is desirable that the polyester resin of the present invention is contained in an amount of 50% by weight or more in the alloy composition. These characteristics must be satisfied.

    Next, the polyester resin production method of the present invention will be specifically described.

  In the method for producing a polyester resin of the present invention, during the polycondensation reaction, a sodium salt is added between the stage where the polymer IV is 0.4 or more and the polymerization is completed, and a highly crystalline and highly transparent polyester resin is added. It is characterized by obtaining.

    In the present invention, the terminal carboxyl group of the polyester is effectively sodiumated by adding a sodium salt when the polymer chain is sufficiently extended, and crystallinity is imparted by sodiumization. Further, since the long-chain polyester is sodium-ized, the affinity for the resin is high and high transparency can be obtained. Conventionally, the technology added before the start of the polycondensation reaction for the purpose of crystallization involves metallizing the carboxyl terminal of the polyester low-mer, and the metallized low-mer has an affinity for the resin ( Solubility) was low, and foreign matter formation and transparency were reduced. In the present invention, since the polyester is sodium-treated at the stage where the molecular weight of the polyester is sufficiently increased, the polyester having a sodium carboxyl group terminal has sufficient affinity for the resin and precipitates as a foreign substance. There is no. This polyester having a carboxyl terminal sodium-ized exhibits a crystallization effect as a true crystal nucleating agent.

    In the polyester resin production method of the present invention, the sodium salt is added during the substantial polycondensation reaction, and is added between the stage where IV is 0.4 or more and the completion of the polymerization reaction. It is necessary. Furthermore, it is preferable to add IV at a stage of 0.5 to 0.57. Earlier than this range, the terminal of the low-mer is sodiumated by the reaction with the low-quantum of polyester. Since the compatibility with the low-molecular weight polyester resin whose terminal is sodium is poor, if the addition is early, foreign matter is generated and transparency is lowered. Further, since the polyester chain is not effectively reacted, the crystallization effect is also reduced. At a time later than this range, the added sodium salt is not uniformly dispersed in the polyester resin, the reaction becomes non-uniform, and the reaction is locally performed under a high concentration condition. For this reason, the cleavage of the main chain is promoted, and as a result, the reaction with the low-mer proceeds, so there is a concern that transparency and crystallinity may be reduced due to the formation of foreign substances.

    In the method for producing a polyester resin of the present invention, the sodium salt added during the polycondensation reaction is preferably an organic crystal nucleating agent. Specific examples of organic crystal nucleating agents include acetic acid, oxalic acid, propionic acid, butyric acid, octanoic acid, lauric acid, stearic acid, behenic acid, montanic acid, benzoic acid, terephthalic acid, myristic acid, toluic acid, salicylic acid , Sodium salts of various organic carboxylic acids such as naphthalenecarboxylic acid and cyclohexanecarboxylic acid, sodium salts of various organic sulfonic acids such as p-toluenesulfonic acid and sulfoisophthalic acid, sodium salt of ethylene-acrylic acid or methacrylic acid copolymer, styrene Sodium salt of maleic anhydride copolymer (so-called ionomer), benzylidene sorbitol and its derivatives, sodium salt of phosphorus compounds such as sodium-2,2′-methylenebis (4,6-di-t-butylphenyl) phosphate, and 2, 2- Chirubisu (4,6-di -t- butyl phenyl) sodium, and others without limitation.

    Among those exemplified above, a sodium carboxylate is preferable, and an aliphatic carboxylate sodium salt is more preferable. In particular, sodium montanate, sodium behenate, sodium stearate and the like, which are long-chain aliphatic carboxylic acid sodium salts (having 18 or more carbon atoms), are preferable. Short chain carboxylic acid sodium salt and aromatic carboxylic acid sodium salt have low compatibility with polyester and are likely to precipitate in the resin, so that coarse foreign matters are easily formed. In addition, in the case of a short-chain carboxylic acid sodium salt, the main chain is likely to be cleaved due to high acidity in addition to low compatibility as in the case of aromatic carboxylic acid. By using a long-chain aliphatic carboxylic acid sodium salt, both high crystallinity and high transparency can be achieved.

    In the polyester resin production method of the present invention, the amount of sodium salt added during the polycondensation reaction is preferably in the range of 2 mol / ton to 35 mol / ton, more preferably 4 mol / ton relative to the polyester resin containing various fillers. It is more preferably 20 to 20 mol / ton. From this range, at least a crystallization effect is exhibited, but a sufficient effect cannot be obtained. On the other hand, when the amount is larger than this range, the amount of unreacted sodium salt increases, which causes a decrease in transparency and formation of coarse foreign matters.

    The method for producing a polyester resin of the present invention is characterized in that ΔTcg is reduced by 10 ° C. or more as compared with the case where no sodium salt is added during the polycondensation reaction.

    The polyester resin to which no sodium salt is added during the polycondensation reaction is the same temperature control, transesterification catalyst, and polymerization catalyst except that the sodium salt is not added during the polycondensation reaction. It is the manufactured polyester resin. The polyester resin of the present invention imparts crystallinity by adding a sodium salt during the polycondensation reaction, and the crystallinity is judged by comparing ΔTcg. Compared to ΔTcg with the polyester resin to which no sodium salt is added during this polycondensation reaction, it is preferably lowered by 10 ° C. or more, more preferably by 20 ° C. or more. When the copolymerization ratio is large, the crystallinity is remarkably reduced, and the elevated temperature crystallization temperature may not be calculated. In that case, comparison with ΔTcg of the maximum copolymerization ratio at which the elevated temperature crystallization temperature can be calculated; To do.

    The polymerization method of the resin of the present invention is not limited, and a known polymerization method such as a direct polymerization method using a dicarboxylic acid and a glycol as a derivative, a transesterification method using a dicarboxylic acid ester and a glycol, or the like can be used.

  Various diols can be used as the diol component. For example, aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, 2-methyl-1,3-propanediol, hexanediol, neopentylglycol, and alicyclic diols Is cyclohexanedimethanol, cyclohexanediethanol, decahydronaphthalene diethanol, decahydronaphthalene diethanol, norbornane dimethanol, norbornane dimethanol, tricyclodecane dimethanol, tricyclodecane ethanol, tetracyclododecane dimethanol, tetracyclododecane diethanol, decalin di Saturated alicyclic primary diols such as methanol and decalin diethanol, 2,6-dihydroxy-9-oxabicyclo [3,3,1] nonane, 3,9-bis 2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane (spiroglycol), 5-methylol-5-ethyl-2- (1,1-dimethyl) 2-hydroxyethyl) -1,3-dioxane, saturated heterocyclic primary diols containing cyclic ethers such as isosorbide, other cyclohexanediols, bicyclohexyl-4,4′-diols, 2,2-bis (4-hydroxys) (Cyclohexylpropane), 2,2-bis (4- (2-hydroxyethoxy) cyclohexyl) propane, cyclopentanediol, 3-methyl-1,2-cyclopentadiol, 4-cyclopentene-1,3-diol, adamantyldiol Various alicyclic diols such as bisphenol A, bisphenol S, styrene Call, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9'-aromatic cyclic diols such as bis (4-hydroxyphenyl) fluorene can be exemplified. In addition to diols, polyfunctional alcohols such as trimethylolpropane and pentaerythritol can also be used. However, it is not limited to the illustrated glycol component.

    Among these, ethylene glycol is preferable from the viewpoint of reactivity and low cost. In addition, two or more types can be combined within a range that does not impair the object of the present invention.

    Further, the dicarboxylic acid component of the present invention is not particularly limited, and general ester forming derivatives of carboxylic acids can be used. As the ester-forming derivative, an acid anhydride such as terephthalic anhydride, an acid halide such as chloride corresponding to dicarboxylic acid, a lower alkyl ester such as dimethyl terephthalate, and the like can be used. Here, for convenience, unless otherwise specified, dicarboxylic acid includes an ester-forming derivative of dicarboxylic acid. Specifically, although not limited to these, examples of the aromatic dicarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, diphenylether-4,4′-dicarboxylic acid, 4,4′-diphenylmethanedicarboxylic acid, benzylmalonic acid and the like. Examples of chain aliphatic dicarboxylic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, methylmalonic acid, ethylmalonic acid, 2,2-dimethylsuccinic acid, 2,3- Examples include dimethyl succinic acid, 3-methyl glutaric acid, and 3,3-dimethyl glutaric acid. Examples of alicyclic dicarboxylic acids include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, 1,4-cyclohexanedione-2,5-dicarboxylic acid. 2,6-decalin dicarboxylic acid, 1,5-decalin dicarboxylic acid, 1,6-decalin dicarboxylic acid, 2,7-decalin dicarboxylic acid, 2,3-decalin dicarboxylic acid, 2,3-norbornane dicarboxylic acid, bicyclo Saturated alicyclic dicarboxylic acids such as [2,2,1] heptane-3,4-dicarboxylic acid, cis-5-norbornene-endo-2,3-dicarboxylic acid, methyl-5-norbornene-2,3- Dicarboxylic acid, cis-1,2,3,6-tetrahydrophthalic acid, methyltetrahydrophthalic acid, 3, , 5,6 tetrahydrophthalic acid, unsaturated aliphatic dicarboxylic acids such as exo-3,5-epoxy-1,2,3,6-tetrahydrophthalic arsenate barrel acids can be exemplified. In addition to dicarboxylic acids, polyfunctional carboxylic acid components such as trimellitic acid and pyromellitic acid can also be used as polyfunctional components.

    Among these, cyclic dicarboxylic acids are preferable from the viewpoint of heat resistance. In particular, terephthalic acid, naphthalenedicarboxylic acid, and isophthalic acid are preferable from the viewpoint of polymerizability, cost, and resin characteristics. These may be used alone or in combination of two or more, as long as the present invention is not impaired.

    The catalyst used in the polyester resin production method of the present invention is not particularly limited, and various catalysts can be used. For example, as an effective catalyst for the transesterification reaction, manganese acetate, cobalt acetate, zinc acetate, tin acetate, alkoxide titanium and the like are used in addition to alkali metal or alkaline earth metal compounds such as calcium acetate, magnesium acetate and sodium acetate. be able to. As the polymerization catalyst, antimony compounds such as antimony trioxide, germanium compounds such as germanium dioxide, titanium compounds such as alkoxide titanium, and composite oxides of aluminum and silica can be used. Moreover, it is preferable to add various phosphorus compounds, such as phosphoric acid, phosphorous acid, and a trimethyl phosphate, as a stabilizer. Among these, ester compounds are preferable from the viewpoint of suppressing the formation of foreign substances, and phosphonate derivatives are more preferable. In particular, triethylphosphonoacetate is preferable from the viewpoints of suppressing the formation of foreign matter and melting heat resistance. The phosphorus compound is preferably added after the transesterification reaction or at the beginning of the polycondensation reaction after the transesterification reaction.

    Although the specific example of the manufacturing method of the polyester resin in this invention is given, it is not restrict | limited to this. For example, in the transesterification method, dimethyl terephthalate, dimethyl naphthalene dicarboxylate, and ethylene glycol are charged into an ester exchange reaction vessel. At this time, the reactivity is improved by adding 1.7 to 2.3 moles of ethylene glycol with respect to the total dicarboxylic acid component. After melting these at about 150 ° C., magnesium acetate and antimony trioxide are added as a catalyst and stirred. Next, methanol is distilled while gradually raising the temperature to 240 ° C., and a transesterification reaction is performed. After the transesterification reaction, triethylphosphonoacetate is added to deactivate the transesterification catalyst.

    Thereafter, the reaction product is charged into a polymerization apparatus, and while the temperature in the polymerization apparatus is gradually raised to 290 ° C., the pressure in the polymerization apparatus is gradually reduced from normal pressure to 133 Pa or less to distill ethylene glycol. When the IV reaches 0.4 or more, the pressure in the polymerization apparatus is once brought to normal pressure with nitrogen gas, and sodium salt is added. After stirring for 5 minutes at normal pressure, the pressure in the polymerization apparatus is gradually reduced and the polymerization reaction is performed at 133 Pa or less, and when the predetermined stirring torque is reached, the reaction is terminated, and the polyester resin is transferred from the polymerization apparatus to the water tank. Discharge into a strand. The discharged polyester resin is quenched in a water tank and wound up, and then cut with a cutter to obtain a polyester chip.

  The present invention will be described more specifically with reference to the following examples.

  In addition, the measuring method of a physical property and the evaluation method of an effect were performed in accordance with the following method.

(1) Glass transition temperature (Tg), melting point (Tm), heat of fusion (ΔTm), temperature rising crystallization temperature (Tcc) and temperature falling crystallization temperature (Tc) of resin pellets
Each value was calculated with respect to the chart obtained at the time of temperature increase in the second cycle using the following measuring machine in accordance with JIS-K7121 (No. 1987).

Apparatus: Differential scanning calorimeter DSCQ100 (manufactured by TA Instruments)
Measurement conditions: Under nitrogen atmosphere Measurement range: 50-280 ° C
Sample weight: 10 mg (using TA Instruments aluminum pan)
Temperature program:
1st cycle Room temperature → Temperature rise (16 ° C / min) → Hold at 50 ° C for 2 minutes → Temperature rise (16 ° C / min) → Hold at 280 ° C for 5 minutes → Take out outside the electric furnace and quench with liquid nitrogen (cool for 2 minutes) → Raise to room temperature (Leave for 5 minutes)
2nd cycle 50 ° C hold for 2 minutes → temperature rise (16 ° C / min) → 280 ° C → temperature drop (16 ° C / min) → 25 ° C
(2) Intrinsic viscosity (IV)
Measurement was performed at 25 ° C. using orthochlorophenol as a solvent.

(3) Resin haze of resin 2 g of polyester resin was dissolved in 20 ml of a phenol / 2,1,2,2, tetrachloroethane 3/2 (volume ratio) mixed solution, and a haze meter (20 mm optical path length was used). The analysis was conducted by integrating sphere type photoelectric photometry using Suga Test Instruments Co., Ltd. HZ-1).

(4) Sodium content 1 g of polyester resin was heated and incinerated on an electric stove, and further incinerated completely in an electric furnace (700 ° C., 1.5 hours). This ashed product was dissolved in 15 ml of dilute hydrochloric acid to obtain a measurement solution, the absorbance was measured at a measurement wavelength of 589 nm using an atomic absorption measurement device, and the amount of sodium was calculated from a calibration curve.

(5) Presence / absence of coarse foreign matter The gut-shaped polyester resin discharged from the lower part of the polymerization apparatus and rapidly cooled in the water tank was visually checked to determine the presence or absence of coarse foreign matter (diameter 30 μm or more).

○: Good (no foreign matter)
Δ: Some foreign matter ×: Coarse foreign matter (6) Centrifugation operation 10 g of a polyester chip and 100 g of orthochlorophenol were heated at 150 ° C. for 3 hours to completely dissolve the chip. The obtained solution was separated for 1 hour at 30 ° C. and 28425 G using a high-speed centrifuge (HIMAC CR 20G manufactured by HITACHI). After separation, 200 ml of acetone was added to the supernatant solution (75 ml) and reprecipitated to recover the polymer.

(7) Thermoforming property After cutting out the cross section of the heat forming product and depositing platinum-palladium, the cross section was observed using a scanning electron microscope S-2100A manufactured by Hitachi, Ltd.

  The mold used for shaping has a shape in which a plurality of triangular prisms having a right-angled isosceles triangle (height 12 μm) with a vertical angle of 90 ° C. are formed in parallel at a pitch of 24 μm (cross section: figure). 1 (a), perspective view: FIG. 1 (b)).

  A molded product shaped using the mold is shown in FIG. The average value of the ratio b / a of the height b (mold design value 12 μm) and the half width a (mold design value 12 μm) of the convex part of the molded product pattern is determined to determine the heat-forming formability. did. If the evaluation result is ○ or △, it is good (○ is even better).

0.8 or more: ○
0.7 or more and less than 0.8: △
Less than 0.7: ×
(8) Heat resistance The heat-formed prism sheet was subjected to a heat resistance test at 100 ° C. for 48 hours, the change in the apex angle of the prism was measured, and the heat resistance was judged. It is good if there is little change in the apex angle.

(9) Film haze Using a haze meter (Nippon Denshoku Co., Ltd .: NDH5000), the film haze of the two-layer laminate molded body (thickness 35 μm) before heat shaping was measured.

Less than 2%: ○
2% or more and less than 2.5%: △
2.5% or more: ×
Example 1
Each of them was weighed at a ratio of 101.0 parts by weight of dimethyl terephthalate and 64.6 parts by weight of ethylene glycol (2 moles of the dicarboxylic acid component), and charged into a transesterification reactor. After the contents were dissolved at 150 ° C., 0.04 parts by weight of magnesium acetate tetrahydrate and 0.03 parts by weight of diantimony trioxide were added and stirred as catalysts.

  The temperature was raised to 190 ° C. over 60 minutes, further raised to 200 ° C. over 60 minutes, and then methanol was distilled while raising the temperature to 240 ° C. over 90 minutes. After distillation of a predetermined amount of methanol, an ethylene glycol solution containing 0.04 part by weight of triethylphosphonoacetate as a catalyst deactivator was added and stirred for 5 minutes to complete the transesterification reaction.

    Thereafter, the reaction product is charged into the polymerization apparatus, and while the temperature in the polymerization apparatus is raised from 235 ° C. to 290 ° C. over 90 minutes, the pressure in the polymerization apparatus is gradually reduced from normal pressure to vacuum to distill ethylene glycol. As the polymerization reaction progressed, the viscosity of the reaction product increased. When IV0.57 was reached, the pressure in the polymerization apparatus was made normal with nitrogen gas, and 0.3 parts by weight of sodium montanate was added. After stirring at normal pressure for 5 minutes, the pressure in the polymerization apparatus was gradually reduced and the polymerization reaction was carried out in vacuum. When the completion target torque was reached, the polymerization reaction was terminated, the inside of the polymerization apparatus was returned to normal pressure with nitrogen gas, the lower part of the polymerization apparatus was opened, and a gut-shaped polyester resin was discharged into the water tank. The discharged polyester resin was quenched in a water tank and then cut with a cutter to obtain a polyester chip.

    Table 2 shows the properties of the obtained polyester resin (A-1).

  Moreover, the foreign material in a polyester resin was removed by performing centrifugation operation using the obtained polyester chip.

  Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Example 2
A polyester resin was obtained in the same manner as in Example 1 except that the sodium salt added during the polycondensation reaction was changed to sodium behenate and the addition amount was changed. The amount of sodium behenate added at this time was set to be the same amount of sodium as 0.3 part by weight of sodium montanate. Table 2 shows the properties of the obtained polyester resin (A-2).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Example 3
A polyester resin was obtained in the same manner as in Example 1 except that the sodium salt added during the polycondensation reaction was changed to sodium stearate and the addition amount was changed. The amount of sodium stearate added at this time was set to be the same amount of sodium as 0.3 part by weight of sodium montanate. Table 2 shows the properties of the obtained polyester resin (A-3).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Example 4
Each of them was weighed at a ratio of 100.8 parts by weight of dimethyl 2,6-naphthalenedicarboxylate and 51.2 parts by weight of ethylene glycol (2 moles of the dicarboxylic acid component), and charged into a transesterification reactor. After the contents were dissolved at 180 ° C., 0.04 parts by weight of magnesium acetate tetrahydrate and 0.03 parts by weight of antimony trioxide were added and stirred as catalysts.

  Methanol was distilled while heating up to 235 ° C. over 150 minutes. After distillation of a predetermined amount of methanol, an ethylene glycol solution containing 0.04 part by weight of triethylphosphonoacetate as a catalyst deactivator was added and stirred for 5 minutes to complete the transesterification reaction.

  Thereafter, the same operation as in Example 1 was performed. Table 2 shows the properties of the obtained polyester resin (B-1).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Example 5
Each of them was weighed at a ratio of 85.9 parts by weight of dimethyl terephthalate, 15.2 parts by weight of dimethyl isophthalate, and 64.6 parts by weight of ethylene glycol (twice as much as the dicarboxylic acid component), and charged into a transesterification reactor.

  Thereafter, the same operation as in Example 1 was performed. Table 2 shows the properties of the obtained polyester resin (C-1).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Example 6
A transesterification reaction apparatus was weighed at a ratio of 86.3 parts by weight of dimethyl terephthalate, 14.8 parts by weight of dimethyl 2,6-naphthalenedicarboxylate, and 62.6 parts by weight of ethylene glycol (2 mols of dicarboxylic acid component). Was charged.

  Thereafter, the same procedure as in Example 1 was performed, and sodium montanate was added during 0.08 parts by weight of the polycondensation reaction. Table 2 shows the properties of the obtained polyester resin (D-1).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the characteristics before and after the centrifugation operation.

Examples 7-12
A polyester resin was obtained in the same manner as in Example 6 except that the amount of sodium salt added during the polycondensation reaction was changed to the addition amount shown in Table 1. Each characteristic of the obtained polyester resin (D2-7) is shown in Table 2.

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Examples 13-15
A polyester resin was obtained in the same manner as in Example 9 except that the IV when adding the sodium salt during the polycondensation reaction was changed to the IV shown in Table 1. Table 2 shows properties of the obtained polyester resin (D8 to 10).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Example 16
A polyester resin was obtained in the same manner as in Example 6 except that the sodium salt added during the polycondensation reaction was changed to sodium behenate and the addition amount was changed. The amount of sodium behenate added at this time was set to be the same amount of sodium as 0.3 part by weight of sodium montanate. Table 2 shows the properties of the obtained polyester resin (D-11).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Example 17
A polyester resin was obtained in the same manner as in Example 6 except that the sodium salt added during the polycondensation reaction was changed to sodium stearate and the addition amount was changed. The amount of sodium stearate added at this time was set to be the same amount of sodium as 0.3 part by weight of sodium montanate. Table 2 shows the properties of the obtained polyester resin (D-12).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Example 18
A polyester resin was obtained in the same manner as in Example 6 except that the sodium salt added during the polycondensation reaction was changed to sodium octoate and the addition amount was changed. The amount of sodium octoate added at this time was set to be the same amount of sodium as 0.3 part by weight of sodium montanate. Table 2 shows properties of the obtained polyester resin (D-13).

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Comparative Example 1
Each of them was weighed at a ratio of 101.0 parts by weight of dimethyl terephthalate and 64.6 parts by weight of ethylene glycol (2 moles of the dicarboxylic acid component), and charged into a transesterification reactor. After the contents were dissolved at 150 ° C., 0.04 parts by weight of magnesium acetate tetrahydrate and 0.03 parts by weight of antimony trioxide were added and stirred as catalysts.

  The temperature was raised to 190 ° C. over 60 minutes, further raised to 200 ° C. over 60 minutes, and then methanol was distilled while raising the temperature to 240 ° C. over 90 minutes. After distillation of a predetermined amount of methanol, an ethylene glycol solution containing 0.04 part by weight of triethylphosphonoacetate as a catalyst deactivator was added and stirred for 5 minutes to complete the transesterification reaction.

  Thereafter, the reaction product is charged into the polymerization apparatus, and while the temperature in the polymerization apparatus is raised from 235 ° C. to 290 ° C. over 90 minutes, the pressure in the polymerization apparatus is gradually reduced from normal pressure to vacuum to distill ethylene glycol. As the polymerization reaction progressed, the viscosity of the reaction product increased. When the completion target torque was reached, the polymerization reaction was terminated, the inside of the polymerization apparatus was returned to normal pressure with nitrogen gas, the lower part of the polymerization apparatus was opened, and a gut-shaped polyester resin was discharged into the water tank. The discharged polyester resin was quenched in a water tank and then cut with a cutter to obtain a polyester chip.

  Table 2 shows the properties of the obtained polyester resin (A-4). Since the obtained polyester resin did not contain sodium element and did not impart a crystallization effect, it was a resin having low crystallinity.

Comparative Example 2
Each of them was weighed at a ratio of 100.8 parts by weight of dimethyl 2,6-naphthalenedicarboxylate and 51.2 parts by weight of ethylene glycol (2 moles of the dicarboxylic acid component), and charged into a transesterification reactor. After the contents were dissolved at 180 ° C., 0.04 parts by weight of magnesium acetate tetrahydrate and 0.03 parts by weight of antimony trioxide were added and stirred as catalysts.

  Methanol was distilled while heating up to 235 ° C. over 150 minutes. After distillation of a predetermined amount of methanol, an ethylene glycol solution containing 0.04 part by weight of triethylphosphonoacetate as a catalyst deactivator was added and stirred for 5 minutes to complete the transesterification reaction.

  Thereafter, the same operation as in Comparative Example 1 was performed. Table 2 shows the properties of the obtained polyester resin (B-2). Since the obtained polyester resin did not contain sodium element and did not impart a crystallization effect, it was a resin having low crystallinity.

Comparative Example 3
Each of them was weighed at a ratio of 85.9 parts by weight of dimethyl terephthalate, 15.2 parts by weight of dimethyl isophthalate, and 64.6 parts by weight of ethylene glycol (twice as much as the dicarboxylic acid component), and charged into a transesterification reactor.

  Thereafter, the same operation as in Comparative Example 1 was performed. Table 2 shows the properties of the obtained polyester resin (C-2). Since the obtained polyester resin did not contain sodium element and did not impart a crystallization effect, it was a resin having low crystallinity.

Comparative Example 4
A transesterification reaction apparatus was weighed at a ratio of 86.3 parts by weight of dimethyl terephthalate, 14.8 parts by weight of dimethyl 2,6-naphthalenedicarboxylate, and 62.6 parts by weight of ethylene glycol (2 mols of dicarboxylic acid component). Was charged.

  Thereafter, the same operation as in Comparative Example 1 was performed. Table 2 shows the properties of the obtained polyester resin (D-14). Since the obtained polyester resin did not contain sodium element and did not impart a crystallization effect, Tcc could not be observed, and the resin had low crystallinity.

Comparative Example 5
A polyester resin was obtained in the same manner as in Example 6 except that the amount of sodium salt added during the polycondensation reaction was changed. Table 2 shows the properties of the obtained polyester resin (D-15). Although the solution haze value of the obtained polyester resin was low and the resin was highly transparent, the crystallinity was insufficient because the content of sodium element was small.

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content.

Comparative Example 6
A polyester resin was obtained in the same manner as in Example 6 except that the amount of sodium salt added during the polycondensation reaction was changed. Table 2 shows the properties of the obtained polyester resin (D-16). The obtained polyester resin had low ΔTcg and high crystallinity, but had high solution haze and low transparency.

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content. As a result, the rate of change in the sodium element content was large, and many sodium elements were removed as foreign substances.

Comparative Example 7
A transesterification reaction apparatus was weighed at a ratio of 86.3 parts by weight of dimethyl terephthalate, 14.8 parts by weight of dimethyl 2,6-naphthalenedicarboxylate, and 62.6 parts by weight of ethylene glycol (2 mols of dicarboxylic acid component). Was charged. After the contents were dissolved at 150 ° C., 0.04 parts by weight of magnesium acetate tetrahydrate and 0.03 parts by weight of antimony trioxide were added and stirred as catalysts.

    The temperature was raised to 190 ° C. over 60 minutes, further raised to 200 ° C. over 60 minutes, and then methanol was distilled while raising the temperature to 240 ° C. over 90 minutes. After distillation of a predetermined amount of methanol, an ethylene glycol solution containing 0.04 part by weight of triethylphosphonoacetate was added as a catalyst deactivator, and after 5 minutes, 0.3 part by weight of sodium montanate was added to the ester. The exchange reaction was terminated.

    Thereafter, the reaction product is charged into the polymerization apparatus, and while the temperature in the polymerization apparatus is raised from 235 ° C. to 290 ° C. over 90 minutes, the pressure in the polymerization apparatus is gradually reduced from normal pressure to vacuum to distill ethylene glycol. As the polymerization reaction progressed, the viscosity of the reaction product increased. After stirring at normal pressure for 5 minutes, the pressure in the polymerization apparatus was gradually reduced and the polymerization reaction was carried out in vacuum. When the completion target torque was reached, the polymerization reaction was terminated, the inside of the polymerization apparatus was returned to normal pressure with nitrogen gas, the lower part of the polymerization apparatus was opened, and a gut-shaped polyester resin was discharged into the water tank. The discharged polyester resin was quenched in a water tank and then cut with a cutter to obtain a polyester chip.

    Table 2 shows the properties of the obtained polyester resin (D-17). Although the obtained polyester resin had high crystallinity, the solution haze value was very high and the transparency was low.

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content. As a result, the rate of change in the sodium element content was large, and many sodium elements were removed as foreign substances.

Comparative Example 8
A polyester resin was obtained in the same manner as in Example 6 except that the IV when adding the sodium salt during the polycondensation reaction was changed to the IV shown in Table 1. Table 2 shows the properties of the obtained polyester resin (D-18). The obtained polyester resin had low crystallinity, high solution haze, and low transparency.

    In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content. As a result, the rate of change in the sodium element content was large, and many sodium elements were removed as foreign substances.

Comparative Example 9
A transesterification reaction apparatus was weighed at a ratio of 86.3 parts by weight of dimethyl terephthalate, 14.8 parts by weight of dimethyl 2,6-naphthalenedicarboxylate, and 62.6 parts by weight of ethylene glycol (2 mols of dicarboxylic acid component). Was charged. After the contents were dissolved at 150 ° C., 0.09 parts by weight of magnesium acetate tetrahydrate, 0.03 parts by weight of antimony trioxide and 0.175 parts by weight of dimethyl phenylphosphonate were added and stirred as catalysts.

    The temperature was raised to 190 ° C. over 60 minutes, further raised to 200 ° C. over 60 minutes, and then methanol was distilled while raising the temperature to 240 ° C. over 90 minutes. The transesterification reaction was completed when a predetermined amount of methanol was distilled off.

  Thereafter, Table 2 shows each characteristic of the polyester resin (D-19) obtained in the same manner as in Comparative Example 1. Since no sodium element was contained, the elevated crystallization temperature could not be detected and the crystallinity was low.

Comparative Example 10
The same procedure as in Example 9 was performed except that the sodium salt added during the polycondensation reaction was changed to 0.07 part by weight of sodium propionate. Table 2 shows the properties of the obtained polyester resin (D-20). The obtained polyester resin had coarse foreign matters, and was a polyester resin having low crystallinity.

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content. As a result, the rate of change in the sodium element content was large, and many sodium elements were removed as foreign substances.

Comparative Example 11
The polyester resin (D-14) obtained in Comparative Example 4 was dried under reduced pressure, and a raw material was prepared by blending 0.3 parts by weight of sodium montanate with respect to the polyester resin. The raw material was supplied to a vent type twin screw extruder, melted and kneaded at 285 ° C. while evacuating from the vent hole, discharged into cold water in a strand form, and immediately cut to obtain a polyester resin. Table 2 shows the properties of the obtained polyester resin (D-21). The obtained polyester resin was highly crystalline, but had a high solution haze value and low transparency. In addition, a significant IV decrease was observed.

  In addition, the obtained polyester chip was used for centrifugation as in Example 1. Table 1 shows the sodium content before and after the centrifugation operation and the rate of change of the sodium content. As a result, the rate of change in the sodium element content was large, and many sodium elements were removed as foreign substances.

Example 19
The polyester resin (D-4) obtained in Example 9 and the PET resin (IV 0.65) were each vacuum-dried at 170 ° C. for 3 hours, and then melted at 280 ° C. in separate extruders, respectively. The resin was extruded from a melted two-layer coextrusion die so that there were two layers. The extruded laminated resin was closely cooled and solidified while applying an electrostatic charge to a cooling drum maintained at 25 ° C., and the cast film was stretched 3.3 times at 90 ° C. in a longitudinal direction using a roll type stretching machine. . Next, the film was introduced into a tenter and transversely stretched 3.4 times at 110 ° C., then heat-treated in a temperature zone controlled at 238 ° C., and subjected to a 4% relaxation treatment at 170 ° C. in the transverse direction. Then, it cooled to room temperature and wound up, and the thickness of the resin layer was 28 micrometers, the thickness of PET layer was 7 micrometers, and the 2 layer laminated film which consists of 35 micrometers in total thickness was obtained. Table 3 shows the film haze of the obtained two-layer laminated film.

    Then, heat shaping was performed. The heat shaping flow is shown in FIG. The mold has the prism shape shown in FIG. 1, and the uneven surface of the mold (g in FIG. 2) whose temperature is controlled by this film (h in FIG. 2) and the heating / cooling plate (f in FIG. 2). Was heated to 120 ° C., pressed at 2.5 MPa, and held there for 30 seconds. Then, after cooling a metal mold | die to 70 degreeC, the press was released and the resin molded product was obtained by releasing from a metal mold | die. Table 3 shows the heat formability and heat resistance of the obtained molded product.

Example 20
A resin molded product was obtained in the same manner as in Example 19 using the polyester resin (D-11) obtained in Example 16. Table 3 shows the heat formability, heat resistance, and film haze of the obtained molded product.

a Width of molded product pattern convex portion b Height of molded product pattern convex portion f Heating / cooling plate g Mold h Film of the present invention

Claims (5)

In a method for producing a polyester by subjecting an ester-forming derivative component of a dicarboxylic acid and a diol component to a transesterification reaction or an esterification reaction, followed by a polycondensation reaction, the IV (intrinsic viscosity) of the polymer is 0. A method for producing a crystalline polyester resin, comprising adding a long-chain aliphatic carboxylic acid sodium salt having 18 or more carbon atoms between the four or more stages and the end of the polycondensation reaction. Method for producing a crystalline polyester resin according to claim 1, wherein the addition of 2 mol / ton or 35 mol / ton or less of an aliphatic carboxylic acid sodium salt against the resulting polyester. Method for producing a crystalline polyester resin according to claim 1 or 2, wherein the sodium salt aliphatic carboxylic acid is at least one type of montanic acid or sodium behenate. The ester-forming derivative component of dicarboxylic acid is selected from at least one of ester-forming derivatives of terephthalic acid, 2,6-naphthalenedicarboxylic acid, and isophthalic acid, and the diol component is ethylene glycol. method for producing a crystalline polyester resin according to any one of 1 to 3. The method for producing a crystalline polyester resin according to any one of claims 1 to 4 , wherein an IV (intrinsic viscosity) of the obtained crystalline polyester resin is 0.55 or more and 0.7 or less. .

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