TWI691522B - Polyester resin pellet, method for producing the same and molded article of the same - Google Patents

Abstract

Provided is a polyester resin particle which is obtained by melt-kneading polycondensation of terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide adduct, and then solidifying Polyester resin particles obtained by phase polymerization, the polyvalent ester is a carboxylic acid ester of a polyvalent alcohol with a trivalent or higher, and the carboxylic acid group has a hindered phenol group, and the polyester resin is derived from the component of the polyvalent ester The content is 0.005~0.04% by mass, and the limiting viscosity of the aforementioned polyester is 0.9~1.5dl/g. While such polyester resin particles are excellent in sag resistance, the molded product obtained using the polyester resin particles is excellent in impact resistance and color tone.

Description

Polyester resin particles, its manufacturing method, and its molded product

The present invention relates to polyester resin pellets suitable as a raw material for extrusion blow molding, a method for producing the same, and a molded article composed of the same.

Polyester resins such as polyethylene terephthalate resin are excellent in transparency, mechanical properties, gas barrier properties, and odor barrier properties. Furthermore, when making polyester resin into a molded product, there is little concern about residual monomers or harmful additives, and it is also excellent in hygiene and safety. Therefore, the polyester resin system utilizes these characteristics as a replacement for the vinyl chloride resin used in the past, and has been widely used in recent years as a hollow container for filling juices, refreshing drinks, seasonings, oils, cosmetics, lotions, and the like.

As a molding method for manufacturing a hollow molded product composed of polyester resin, an extrusion blow molding method is known, which is a method in which a melted and plasticized resin is passed through a die orifice to make it into a cylindrical parison It is squeezed (parison), the parison is held in a mold while it is in a softened state, and a fluid such as air is blown into the interior to form. Compared to injection blow molding The forming method and the extrusion blow molding method are simple and do not require a high degree of technology for the production and molding of the mold. Therefore, the equipment cost or the production cost of the mold are cheap, and are suitable for many varieties and small quantities. Moreover, there is an advantage that it is possible to produce a molded product having a complex shape of thin objects, deep objects, large objects, handles, and the like.

On the other hand, general-purpose polyester resins generally have a low melt viscosity, so when extrusion blow molding is to be performed, the extruded parison will significantly draw-down, making it difficult to form. Here, in general, when extruding a polyester resin for forming a blow-molded plastic bottle, sag resistance can be imparted by adding a small amount of a crosslinking agent, etc. Even if it can be formed, the resulting molded product is also resistant Insufficient impulsiveness. In addition, in general, polyester resins are easily oxidized by heat for a long period of time during melt molding or solid-phase polymerization, etc., and cause thermal deterioration such as yellow coloration, molecular weight reduction, and gel-like component generation.

In order to solve these problems, various polyester resins suitable for extrusion blow molding or thermoforming have been proposed in the past. As one of such conventional techniques, those who add hindered phenol-based antioxidants are known (refer to Patent Documents 1 to 3).

Patent Document 1 describes a copolymerized polyester, which contains terephthalic acid units, ethylene glycol units, and 1,4-cyclohexanedimethanol units as main components, and the content of hindered phenolic antioxidants is 0.2 to 1.0 Mass%, the content of germanium and antimony (catalyst) meet the specified conditions. Patent Document 1 describes that by using a catalyst with a specified composition and a hindered phenolic antioxidant, the decomposition reaction during polymerization is suppressed and polymerization can be performed quickly, and a high degree of polymerization can be obtained without deteriorating color tone or transparency. Polyester, same It also suppresses the thermal decomposition during molding without causing deterioration of the color tone after molding. Patent Document 2 describes a polyester resin composition prepared by blending 0.05 to 1 part by weight of a hindered phenolic antioxidant with respect to 100 parts by weight of a polyester resin, the polyester resin system containing a dicarboxylic acid unit and a diol Units, 1 to 60 mole% of diol units are diol units having a cyclic acetal skeleton. In addition, Patent Document 2 describes that by adding the above-mentioned antioxidant, the generation of yellow coloring or gel components can be suppressed. However, the molded products obtained by extrusion blow molding the polyester resins described in Patent Documents 1 and 2 have insufficient impact resistance.

Patent Document 3 describes a method for producing particles composed of a polyester resin composition, which is obtained by melt polymerization of polyester (A) particles and polyester (B) particles, and then the polyester The particles of (A), the particles of polyester (B), and the hindered phenolic antioxidant are melt-kneaded, and solid-phase polymerization is performed to obtain a polyester resin composition, in which the polyester (A) is composed of terephthalic acid units and The ethylene glycol unit is the main body, and the polyester (B) is mainly composed of terephthalic acid unit, ethylene glycol unit and cyclohexanedimethanol unit. However, since this method has many steps, it is not easy to produce particles with good productivity. Moreover, the transparency of the molded product obtained by using the particles may be insufficient.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2002-338674

[Patent Document 2] Japanese Patent Laid-Open No. 2007-326890

[Patent Document 3] Japanese Patent Laid-Open No. 2011-252087

The present invention is an invention completed to solve the above-mentioned problems, and an object of the present invention is to provide a molded product having excellent sag resistance, good impact resistance and good color tone, and suitable for the manufacture of thick-walled molded products or extrusion blow molding Polyester resin pellets used as raw materials for forming and manufacturing method thereof.

The above-mentioned problem can be solved by providing polyester resin particles which are an adduct of terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide, and Polyester resin particles obtained by melt-kneading polycondensation after polycondensation and solid-phase polymerization, the polyvalent ester is a carboxylic acid ester of a trivalent or higher polyhydric alcohol, and the carboxylic acid group has a hindered phenol group, the aforementioned The dicarboxylic acid unit system in the polyester is mainly composed of terephthalic acid units, and the diol unit system in the polyester is mainly composed of ethylene glycol units, cyclohexane dimethanol units or from bisphenol A epoxy It is composed of units of ethane adducts. The content of ethylene glycol units is 75-98 mol% relative to the total of the glycol units. The units of cyclohexane dimethanol and bisphenol A ethylene oxide The content of the unit of the adduct is 2 to 25 mol%, the content of the component derived from the polyester in the polyester resin is 0.005 to 0.04 mass%, and the limiting viscosity of the polyester is 0.9 to 1.5dl/ g.

Forming using the aforementioned pellets and extrusion blow molding The strain is a suitable embodiment of the present invention.

The above-mentioned problem can also be solved by providing the manufacturing method of the aforementioned polyester resin particles, which is an adduct of terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide, And the above-mentioned polyhydric ester is melt-kneaded and then polycondensed and cut to obtain intermediate particles, and then the intermediate particles are subjected to solid-phase polymerization.

The polyester resin particles of the present invention can obtain a molded product having excellent sag resistance during extrusion blow molding, and good impact resistance and color tone. By the production method of the present invention, such polyester resin particles can be easily produced.

[FIG. 1] A diagram showing a method of obtaining a semi-crystallization time.

[The best form for carrying out the invention]

The embodiments of the present invention will be described below, but the present invention is not limited to these.

The polyester resin particles of the present invention consist of terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide adduct, and polyester by melt-kneading and then polycondensation. Formed by solid state polymerization, front The polyester is a carboxylic acid ester of a trivalent or higher polyol, and the carboxylic acid has a hindered phenol group. The dicarboxylic acid unit in the polyester is mainly composed of terephthalic acid units. The diol units are mainly composed of ethylene glycol units, cyclohexanedimethanol units or units derived from bisphenol A ethylene oxide adducts, relative to the total of the glycol units. The content of the unit is 75~98 mol%, the content of the unit of cyclohexanedimethanol and the unit derived from the bisphenol A ethylene oxide adduct is 2~25 mol%, the above-mentioned polyester resin comes from The content of the components of the aforementioned polyester is 0.005 to 0.04% by mass, and the limiting viscosity of the aforementioned polyester is 0.9 to 1.5 dl/g. In the present invention, the polyester resin particles may be referred to as "first particles".

The polyester of the present invention is mainly composed of: dicarboxylic acid units with terephthalic acid units as the main body; ethylene glycol units, and cyclohexane dimethanol units or from bisphenol A ethylene oxide adducts The unit is the main diol unit; and, is derived from the unit of the aforementioned polyester.

The content of terephthalic acid units in the polyester of the present invention is generally 80 mol% or more, preferably 90 mol% or more, relative to the total amount of dicarboxylic acid units in the aforementioned polyester. It is preferably 95 mol% or more, and more preferably the dicarboxylic acid unit in the aforementioned polyester is substantially only a terephthalic acid unit.

The polyester of the present invention contains cyclohexanedimethanol units or units derived from bisphenol A ethylene oxide adduct as diol units other than ethylene glycol units. Here, the polyester may contain at least one of cyclohexanedimethanol units and units derived from the bisphenol A ethylene oxide adduct as a glycol unit other than ethylene glycol units. As the second unit other than ethylene glycol Alcohol units can reduce the melting point of polyesters by containing cyclohexanedimethanol units or units derived from bisphenol A ethylene oxide adduct, so the molding temperature in direct blow molding can be reduced. From the viewpoint of impact resistance at a low temperature, it is preferable that the above-mentioned polyester contains a cyclohexanedimethanol unit as a glycol unit other than ethylene glycol units. On the other hand, from the viewpoint of the chemical resistance of high-concentration alcohols, the diol unit other than the ethylene glycol unit of the polyester is the unit containing the bisphenol A ethylene oxide adduct Better.

The cyclohexane dimethanol unit in the aforementioned polyester is at least at least one selected from 1,2-cyclohexane dimethanol unit, 1,3-cyclohexane dimethanol unit, and 1,4-cyclohexane dimethanol unit. One type of bivalent unit is sufficient. Among them, in terms of ease of obtaining, easy to make the aforementioned polyester crystalline, easy to make the products between particles adhere to each other during solid-phase polymerization, and further improve the impact resistance of the resulting molded product, cyclohexanone 1,4-cyclohexanedimethanol units are preferred as the ethanedimethanol units.

The units of cyclohexane dimethanol exist in cis and trans forms, but the ratio of cis to trans forms of cyclohexane dimethanol units in the aforementioned polyester is not particularly limited. Among them, the ratio of cis:trans of cyclohexanedimethanol units in the polyester is in the range of 0:100~50:50, which makes it easy for the polyester to become crystalline, when solid phase polymerization The point where it is difficult for the product between particles to stick together and the point where the impact resistance of the resulting molded product is further improved are better.

In the aforementioned polyester, the unit derived from the bisphenol A ethylene oxide adduct is obtained by adding at least one ethylene oxide to each hydroxyl group of bisphenol A. The amount of addition of ethylene oxide, relative to bisphenol A 1 mole, is usually 2.0~4.0 moles.

The total content of cyclohexanedimethanol units in the polyester of the present invention and the units derived from the bisphenol A ethylene oxide adduct is 2 to 25 relative to the total diol units in the polyester Moore%. When the total content of the aforementioned units of cyclohexanedimethanol and the units derived from the bisphenol A ethylene oxide adduct is less than 2 mole %, the impact resistance and transparency of the resulting molded product will decrease. The aforementioned content is preferably 4 mol% or more, and more preferably 8 mol% or more. On the other hand, when the aforementioned content exceeds 25 mol%, it becomes difficult to increase the solid-phase polymerization temperature, the productivity decreases, and the color tone of the resulting molded article also deteriorates. The aforementioned content is preferably 18 mol% or less.

The content of ethylene glycol units in the polyester of the present invention is 75 to 98 mol% relative to the total of the glycol units in the polyester. When the content of the aforementioned ethylene glycol unit is less than 75 mole %, it becomes difficult to increase the solid-phase polymerization temperature, the productivity decreases, and the color tone of the resulting molded product also deteriorates. The content of the aforementioned ethylene glycol unit is preferably 82 mol% or more. On the other hand, when the content of the aforementioned ethylene glycol unit exceeds 98 mole %, the impact resistance and transparency of the resulting molded product will decrease. The content of the aforementioned ethylene glycol unit is preferably 96 mol% or less, and more preferably 92 mol% or less.

The total content of ethylene glycol units, cyclohexane dimethanol units, and units derived from bisphenol A ethylene oxide adduct in the polyester of the present invention is relative to the total amount of glycol units in the polyester In general, it is usually 80 mol% or more, preferably 90 mol% or more, and preferably 95 mol% %the above. Generally, the polyester of the present invention contains diethylene glycol units which are by-products in the polycondensation reaction in the range of 1 to 5 mol% relative to the total diol units in the polyester.

The unit derived from the polyester in the aforementioned polyester is a carboxylic acid ester of a polyvalent alcohol with a trivalent or higher and the carboxylic acid has a hindered phenol group. By using the polyester and terephthalic acid, ethylene glycol, It is melt-kneaded together with cyclohexanedimethanol or bisphenol A ethylene oxide adduct and is subjected to polycondensation to be contained in the aforementioned polyester. In this polycondensation polymerization, the polyol unit of the polyester or the carboxylic acid unit having a hindered phenol group is contained in the polyester by the transesterification reaction. The aforementioned polyol unit is contained in the main chain, branch or terminal of the aforementioned polyester. In addition, a part of the aforementioned polyol unit becomes a crosslinking point and functions as a crosslinking agent. On the other hand, a part of the carboxylic acid unit having a hindered phenol group is contained at the end of the aforementioned polyester, and a part is contained together with the polyol unit in a state of being bonded to the aforementioned polyol unit In the aforementioned polyester. As described above, by including the unit derived from the above-mentioned polyester in the above-mentioned polyester, it is considered that the polyester resin particles of the present invention can be improved in sag resistance, and at the same time, the color tone of the resulting molded product can be improved. The aforementioned polyhydric ester is preferably a carboxylic acid ester of a polyhydric alcohol having a trivalent value or more and a pentavalent value or less. Examples of the aforementioned polyesters include neopentaerythritol-[[(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]] and 1,3,5-ginseng[2-[ 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy]ethyl]hexahydro-1,3,5-triazine-2,4,6-trione, etc. .

The content of the unit derived from the aforementioned polyester in the polyester resin of the present invention is 0.005 to 0.04% by mass. Here, the content of the components derived from the aforementioned polyester in the polyester resin is derived from the The total amount of the unit of the aforementioned polyester and the component not incorporated in the polyester chain. However, it is considered that the aforementioned polybasic ester system added at the time of melt-kneading is mostly contained in the polyester chain. When the content of the unit derived from the aforementioned polyester is less than 0.005% by mass, the polyester resin particles may be reduced in sag resistance, or when the polyester is heated during polymerization or molding when the polyester is heated It becomes yellowish, and the hue of the resulting molded product may be reduced. On the other hand, when the content of the unit derived from the aforementioned polyester exceeds 0.04% by mass, the crosslinking proceeds excessively due to the unit derived from the polyester, so that the crosslinking proceeds, and the melt viscosity may become too high. Or the impact resistance of the resulting molded product may be reduced. The content of the unit derived from the aforementioned polyester is preferably 0.03% by mass or less, and more preferably 0.02% by mass or less.

The total content of terephthalic acid unit, ethylene glycol unit, cyclohexanedimethanol unit, unit derived from bisphenol A ethylene oxide adduct and unit derived from polyester in the polyester of the present invention, It is preferably 80 mol% or more, more preferably 90 mol% or more, and more preferably 95 mol% or more with respect to the total amount of all structural units in the polyester. When the polyester whose content is less than 80 mol% is produced, the resin tends to be stuck due to the softening of the resin during solid-phase polymerization, and it may become difficult to increase the degree of polymerization.

The aforementioned polyester may have terephthalic acid units, ethylene glycol units, cyclohexanedimethanol units, units derived from bisphenol A ethylene oxide adducts, and units derived from the aforementioned polyesters, as required Other than 2 functional compound units. The content of other bifunctional compound units (the total when there are two or more types of units) is preferably 20 mol% or less relative to the total amount of all structural units constituting the polyester, and is more preferably 10 mol% or less, more preferably 5 mol% or less. As the other bifunctional compound unit that can be contained in the polyester, as long as it is a dicarboxylic acid unit, a diol unit, or a hydroxycarboxylic acid unit, it may be any of an aliphatic bifunctional compound unit and an alicyclic formula 2. Functional compound unit, or aromatic two-functional compound unit. Examples include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, and ester-forming derivatives of these; Aliphatic dicarboxylic acids such as cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dimer acid, or ester-forming derivatives of these; neopentyl glycol, 1,4-butanediol, 1, Aliphatic diols such as 5-pentamethylene glycol, 1,6-hexamethylene glycol, diethylene glycol, dimer diol, etc.; ethylene oxide adducts of bisphenol S, etc. Derivative divalent construction unit.

The aforementioned polyester may have terephthalic acid units, ethylene glycol units, cyclohexanedimethanol units, and bisphenol A ethylene oxide adducts as long as it does not hinder the effects of the present invention. Units derived from the aforementioned polyester units and other multifunctional compound units other than the above-mentioned other bifunctional compound units. The other polyfunctional compound units are polyfunctional compound units derived from polyfunctional compounds having three or more carboxyl groups, hydroxyl groups, and/or ester-forming groups. The content of other polyfunctional compound units (the total when there are two or more units) is preferably 0.04% by mass or less, and more preferably 0.02% by mass relative to the total structural unit of the polyester. % Or less, preferably it is not substantially contained. Examples of other polyfunctional compound units include polyfunctional compound units derived from trimellitic acid, pyromellitic acid, trimesic acid, trimethylolpropane, and glycerin.

In addition, the polyester may be derived from at least one monofunctional compound derived from a monocarboxylic acid other than the carboxylic acid having a hindered phenol group, a monoalcohol, and an ester-forming derivative as required. Other monofunctional compound units. Other monofunctional compound unit functions as an end-capping compound unit to block the molecular chain end groups and/or branched end groups in the polyester to prevent excessive crosslinking and gelation in the polyester Of generation. When the polyester has such other monofunctional compound units, the content of the other monofunctional compound units (the total when there are two or more types of units) is relative to the total structural unit of the polyester In particular, it is preferably 1 mol% or less, and more preferably 0.5 mol% or less. When the content of the other monofunctional compound unit in the polyester exceeds 1 mol%, the polymerization rate at the time of manufacturing the polyester becomes slow, and the productivity is likely to decrease. As the other monofunctional compound unit, a unit derived from a monofunctional compound selected from benzoic acid, 2,4,6-trimethoxybenzoic acid, 2-naphthoic acid, stearic acid, and stearyl alcohol can be exemplified. Wait.

The polyester resin particles of the present invention consist of terephthalic acid, ethylene glycol, cyclohexanedimethanol, or bisphenol A ethylene oxide adduct, and the above-mentioned polyester by melt-kneading to condense and then solidify The result of phase polymerization.

The method of melt-kneading polycondensation of terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide adduct, and the aforementioned polyvalent ester is not particularly limited, and p-benzene can be used as an example Dicarboxylic acid or ester-forming derivatives, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide adducts, the aforementioned polyesters, and other bifunctional compounds and polyfunctionals as required above Compounds or monofunctional compounds as raw materials, and After the esterification reaction or the transesterification reaction, the obtained polyester oligomer is melt-condensed and polymerized. Specifically, for example, terephthalic acid, ethylene glycol, and cyclohexanedimethanol or bisphenol A ethylene oxide adduct can be used to perform an esterification reaction or an ester exchange reaction. A method of adding the above-mentioned polybasic ester to the polymer for melt polycondensation, or using terephthalic acid, ethylene glycol, cyclohexanedimethanol, or bisphenol A ethylene oxide adduct, and the above-mentioned polybasic ester to perform esterification After the chemical reaction or the transesterification reaction, a method for melt-condensing the obtained polyester oligomer and the like. The aforementioned polybasic ester system may be added before performing the esterification reaction or transesterification reaction, or may be added after performing these reactions. In addition, raw materials other than the above-mentioned polybasic esters may be added as appropriate before the esterification reaction or transesterification reaction, or may be added after the reaction.

As described above, it is a feature of the present invention that the aforementioned polyester is melt-kneaded together with terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide adduct together one. With this, the sag resistance of the polyester resin particles can be improved. In addition, it is possible to suppress the thermal deterioration of the polyester resin in the subsequent polymerization step or molding, and it is possible to obtain a molded product with a good color tone.

The above-mentioned esterification reaction or transesterification reaction system puts the above-mentioned raw materials, polymerization catalysts, and additives such as anti-colorants as required into the reactor, under absolute pressure under a pressure of about 0.5 MPa or The reduction is preferably carried out while distilling off the produced water or alcohol at a temperature of 160 to 280°C.

The melt-condensation polymerization reaction following the esterification reaction or transesterification reaction is preferably added to the obtained polyester oligomer as needed The above-mentioned raw materials, polycondensation catalysts, additives such as anti-coloring agents, etc. are carried out at a temperature of 260 to 290°C under a reduced pressure of 1 kPa or less until a polyester with a desired viscosity can be obtained. When the reaction temperature of the melt-condensation polymerization reaction is less than 260°C, the polymerization activity of the polymerization catalyst is low, and there is a possibility that the polyester with the desired degree of polymerization cannot be obtained. On the other hand, when the reaction temperature of the melt polymerization reaction exceeds 290°C, the decomposition reaction becomes easy to proceed, and as a result, there is a possibility that the polyester with the desired degree of polymerization cannot be obtained. The melt polycondensation reaction can be carried out using, for example, a tank-type batch polycondensation device, a continuous polycondensation device composed of a 2-axis rotary horizontal reactor, and the like.

As the polymerization catalyst used in the above-mentioned condensation polymerization, a compound containing a germanium element, an antimony element, and a titanium element is preferable. As the compound containing antimony element, antimony trioxide, antimony chloride, antimony acetate, etc. can be used. As the compound containing germanium element, germanium dioxide, germanium tetrachloride, tetraethoxygermanium, etc. can be used. As the compound, tetraisopropyl titanate, tetrabutyl titanate and the like can be used. Among them, antimony trioxide and germanium dioxide are preferred in terms of polymerization catalyst activity, physical properties of the resulting polyester, and cost. When a polycondensation catalyst is used, the amount of addition is based on the mass of the dicarboxylic acid component, and the amount in the range of 0.002 to 0.8% by mass is preferred.

When an anti-coloring agent is used in the above-mentioned polycondensation, for example, a phosphoric acid compound including phosphorous acid or the ester may be used, and these may be used alone or in combination of two or more kinds. Examples of the phosphoric acid compound include phosphorous acid, phosphite, phosphoric acid, trimethyl phosphate, and triphenyl phosphate. The use amount of the anti-coloring agent is preferably in the range of 80 to 1000 ppm relative to the total of the dicarboxylic acid component and the diester component. In addition, in order to suppress the cohesion The coloration caused by the thermal decomposition of the ester is preferable to add a cobalt compound such as cobalt acetate. The amount of use is within the range of 100 to 1000 ppm relative to the total amount of the dicarboxylic acid component and the diester component. Better.

In the above-mentioned polycondensation, in order to form a terephthalic acid unit, terephthalic acid ester can also be used. The alcohol portion of the terephthalate is not particularly limited, and examples include monohydric alcohols such as methanol and ethanol; ethylene glycol, cyclohexanedimethanol, and bisphenol A ethylene oxide, which are the constituent units of the aforementioned polyester, are added Polyols, etc.

In the above-mentioned condensation polymerization, in order to form ethylene glycol units, monoesters or diesters of ethylene glycol may also be used. The carboxylic acid portion of the carboxylic acid ester is not particularly limited, and examples thereof include monocarboxylic acids such as formic acid, acetic acid, and propionic acid.

The limit viscosity of the polyester obtained by melt-condensation polymerization is preferably in the range of 0.4 to 0.9 dl/g in terms of workability and the like. When the limit viscosity of the polyester obtained by melt polycondensation is less than 0.4 dl/g, when the polyester is taken out from the reactor, it becomes difficult to extrude into strands or flakes because the melt viscosity is too low Shape, and it is difficult to cut evenly into pellets. Furthermore, when the polyester obtained by melt-condensation polymerization is subjected to solid-phase polymerization, it takes a long time to quantify the polymer, and there is a possibility that productivity will be lowered. The limiting viscosity of the aforementioned polyester is preferably 0.5 dl/g or more, and more preferably 0.6 dl/g or more. On the other hand, when the limiting viscosity of the aforementioned polyester is higher than 0.9 dl/g, because the melt viscosity is too high, it may become difficult to take out the polyester from the reactor, or there is a risk of coloring due to thermal degradation. . The limiting viscosity of the aforementioned polyester is preferably 0.85 dl/g or less, and more preferably 0.8 dl/g or less.

The polyester obtained in the above-mentioned manner is extruded into strands, sheets, etc., and after cooling, it is cut by a strand cutter or a sheet cutter, etc., to make cylindrical, elliptical column, disc Intermediate particles in the shape of lumps, lumps, etc. The aforementioned cooling after extrusion can be performed by, for example, a water cooling method using a water tank, a method using a cooling roller, an air cooling method, or the like.

In order to further increase the degree of polymerization of the intermediate particles obtained in this way, the intermediate particles are subjected to solid-phase polymerization. It is preferable to heat before solid-phase polymerization and crystallize a part of the polyester in advance. By such a method, it is possible to prevent the particles from sticking during solid-phase polymerization. The temperature for crystallization is suitably 100 to 180°C. As a method of crystallization, it can be crystallized in a vacuum drum, or it can be crystallized by heating in an air circulation heating device. When heating in an air circulation heating device, the internal temperature is preferably 100 to 160°C. Compared with using a vacuum drum for crystallization, when using an air circulation type heating device for heating, the time required for crystallization can be shortened because the heat conduction is good, and the device is also inexpensive. The time required for crystallization is not particularly limited, but is usually about 30 minutes to 24 hours. Before crystallization, it is also preferable to dry the particles at a temperature less than 100°C.

The temperature of solid-phase polymerization is suitably 170 to 250°C. If the temperature of the solid-phase polymerization is less than 170° C., the time of the solid-phase polymerization may become longer, which may lower the productivity. The temperature of the solid-phase polymerization is more suitably 175°C or higher, and more suitably 180°C or higher. On the other hand, if the temperature of the solid phase polymerization exceeds 250°C, the particles may stick. The temperature of the solid-phase polymerization is more suitably 240°C or lower, and more suitably 230°C or lower. The time for solid phase polymerization is usually about 5 to 70 hours. Also, during solid state polymerization The catalyst used in melt polymerization may also coexist.

In addition, the solid-phase polymerization system is preferably carried out under reduced pressure or in an inert gas such as nitrogen gas. In addition, in order not to cause adhesion between particles, it is preferable to perform solid-phase polymerization while moving the particles by an appropriate method such as a rotating method, a gas fluidized bed method, or the like. The pressure during solid-phase polymerization under reduced pressure is suitably 1 kPa or less.

As long as it does not hinder the effect of the present invention, the polyester resin may contain other additives, such as coloring agents such as dyes or pigments, stabilizers such as ultraviolet absorbers, antistatic agents, flame retardants, Flame retardant auxiliary, lubricant, plasticizer, inorganic filler, etc. The content of these additives in the polyester resin is preferably 10% by mass or less, and more preferably 5% by mass or less.

The limit viscosity of the polyester obtained after solid-phase polymerization must be in the range of 0.9~1.5dl/g. If the limiting viscosity is less than 0.9 dl/g, the sag resistance is poor, and at the same time the strength, impact resistance and transparency of the resulting molded product are reduced. The limiting viscosity is suitably 1.0 dl/g or more, and more suitably 1.05 dl/g or more. On the other hand, if the limiting viscosity exceeds 1.5 dl/g, the melt viscosity may become too high, which may lower the melt formability and the productivity may also decrease. The limiting viscosity is suitably 1.4 dl/g or less, and more suitably 1.3 dl/g or less.

From the viewpoint of further improving the transparency of the obtained molded product, the semi-crystallization time at the crystallization peak temperature of the polyester contained in the polyester resin particles obtained after solid-phase polymerization is preferably 30 minutes or more. The semi-crystallization time is more preferably 30 minutes or more. In the present invention, the so-called "knot "Crystal Wave Peak Temperature" refers to the temperature measured by using a differential calorimeter (DSC) to raise the temperature of the amorphous polyester resin particles from 10°C/min from normal temperature (20°C) to a temperature above the melting point (280°C) The temperature of the heat generation peak accompanying crystallization. In addition, the "semi-crystallization time at the crystallization peak temperature" refers to the use of a differential calorimeter (DSC) to heat the polyester resin particles to a temperature above the melting point (280°C) and melt them. -50°C/min after quenching to the crystallization peak temperature, when maintaining the crystallization peak temperature and isothermal crystallization, after reaching the crystallization peak temperature, the heat generated by the isothermal crystallization reaches the total heating It means the time up to 1/2 of the amount.

From the viewpoint of preventing the particles from sticking to the inside of the drum during solid-phase polymerization, the crystallization enthalpy of the polyester contained in the polyester resin particles is preferably 20 J/g or more. Since the particles obtained after solid-phase polymerization contain polyester that undergoes crystallization at a high temperature for a long period of time, it has such a large crystal melting enthalpy. The crystal melting enthalpy is more suitably 23 J/g or more. The crystal melting enthalpy is usually 60 J/g or less.

Various molded products can be obtained by melt-molding the obtained polyester resin particles. The molding method is not particularly limited, and various melt molding methods such as extrusion molding, injection molding, and the like can be used. Furthermore, the molded product can also be obtained after further processing the molten molded product. Among them, the polyester resin particles of the present invention are suitable for extrusion molding because of their high viscosity during melt molding. The temperature of the resin composition at the time of extrusion molding is preferably a temperature within the range of (melting point of polyester resin + 10°C) to (melting point of polyester resin + 70°C), and is set to (poly Melting point of ester resin +10℃)~(Polyester resin A temperature within the range of melting point +40°C is more preferable. By pressing at a temperature closer to the melting point, sag can be suppressed.

When the polyester resin composition of the present invention is used to produce a sheet or film by extrusion molding such as the T-die method or inflation method, there is no drape, necking, film sloshing, or unmelted particles. This produces high-quality sheets or films with good productivity. In addition, when secondary processing such as thermoforming is performed using the sheet or film obtained in this way, when forming deep-drawn molded products or large-sized molded products, the degree of drape is small and the degree of crystallization is good, Therefore, in the step of applying external force such as vacuum suction or compressed air, uneven thickness or whitening is not likely to occur, and a molded product with good shapeability can be obtained.

In addition, during extrusion molding, the polyester resin particles of the present invention are particularly suitable for extrusion blow molding. The method of extrusion blow molding is not particularly limited, and can be performed in the same manner as the conventionally known extrusion blow molding method. For example, it can be carried out by a method as follows: the polyester resin particles of the present invention are melt-extruded to form a cylindrical parison, and while the parison is in a softened state, it is pinched and blown in with a blow mold The gas such as air expands the parison into the specified hollow shape along the shape of the mold cavity. When the polyester resin particles of the present invention are used, the extruded parison has good drapeability, and a hollow molded product can be produced with good productivity.

The thus-obtained molded product has excellent transparency, good appearance and color tone, and particularly has high impact resistance among mechanical strengths. Moreover, due to its excellent gas barrier properties, odor barrier properties, moisture resistance, chemical resistance, and other characteristics, it can be used in various applications. Also, it can be made A molded product with a laminated structure with other thermoplastic resins.

It is also suitable as follows: a polyester resin particle and the dicarboxylic acid unit system in the polyester is mainly composed of terephthalic acid units, and the diol unit system in the polyester is mainly composed of ethylene glycol units and ring Hexane dimethanol units or units derived from bisphenol A ethylene oxide adducts, the content of ethylene glycol units is 75 to 98 mole% relative to the total of the glycol units, cyclohexane The content of the unit of dimethanol and the unit derived from the bisphenol A ethylene oxide adduct is 2 to 25 mol%, and the aforementioned polyester resin contains 0.005 to 0.04% by mass of the component derived from the polyester, the polyester It is a carboxylic acid ester of a polyhydric alcohol with a trivalent or higher, and the carboxylic acid has a hindered phenol group. The limiting viscosity of the aforementioned polyester is 0.9 to 1.5 dl/g, and the crystal melting enthalpy is 20 J/g or more, and it is semi-crystalline Time is more than 30 minutes. The molded product obtained by using the polyester resin particles has excellent transparency.

The aforementioned polyester system is mainly composed of the following units: dicarboxylic acid units mainly composed of terephthalic acid units; ethylene glycol units, cyclohexane dimethanol units or bisphenol A ethylene oxide addition The unit of the substance is the main diol unit; and, the unit derived from the polyester. The respective constitutions of the dicarboxylic acid unit, the diol unit and the unit derived from the polyvalent ester are the same as the first particles.

The content of the unit derived from the polyester in the polyester resin is 0.005 to 0.04% by mass. The content of the unit derived from the aforementioned polyester is preferably 0.03% by mass or less, and more preferably 0.02% by mass or less.

Terephthalic acid unit and ethylene glycol in the aforementioned polyester The total content of cyclohexane dimethanol units, units derived from bisphenol A ethylene oxide adducts and units derived from the aforementioned polyesters, relative to the total amount of all structural units in the aforementioned polyesters, More than 80 mole% is better, more than 90 mole% is better, and more than 95 mole% is better.

The aforementioned polyester may have terephthalic acid units, ethylene glycol units, cyclohexanedimethanol units, units derived from bisphenol A ethylene oxide adducts, and units derived from polyesters, as required Of 2 functional compound units. The content of other bifunctional compound units (the total when there are two or more types of units) is preferably 20 mol% or less, and 10 mol relative to the total structural units constituting the polyester. % Or less is more preferable, and 5 mol% or less is even better. Examples of the other bifunctional compound units that can be contained in the polyester include the other bifunctional compound units in the polyester contained in the first particle.

As long as the aforementioned polyester is within the range that does not hinder the effect of the present invention, other than terephthalic acid units, ethylene glycol units, cyclohexanedimethanol units, and units derived from bisphenol A ethylene oxide adduct , Units derived from the polyester and the above-mentioned other bifunctional compound units may also have other multifunctional compound units. The content of other polyfunctional compound units (the total when there are two or more types of units) is preferably 0.04% by mass or less, and 0.02% by mass or less, based on the total structural unit of the polyester. It is more preferable, and it is more preferable that it is not substantially contained. As other polyfunctional compound units, other polyfunctional compound units contained in the polyester contained in the first particles described above can be exemplified.

The aforementioned polyester may also have Other monofunctional compound units derived from at least one monofunctional compound other than phenol-blocking carboxylic acids, monocarboxylic acids, monoalcohols, and ester-forming derivatives of these. If the polyester has such other monofunctional compound units, the content of the other monofunctional compound units (the total if there are two or more types of units) is relative to the total of all the structural units of the polyester In other words, 1 mol% or less is preferable, and 0.5 mol% or less is more preferable. As the other monofunctional compound unit, the other monofunctional compound unit contained in the polyester contained in the first particle mentioned above can be exemplified.

The semi-crystallization time at the crystallization peak temperature of the polyester contained in the polyester resin particles must be 30 minutes or more. If the semi-crystallization time is less than 30 minutes, the transparency of the resulting molded product will decrease. It is more appropriate if the semi-crystallization time is 40 minutes or more. The definition and appropriate range of the semi-crystallization time are the same as the first particles.

The crystalline melting enthalpy of the polyester contained in the polyester resin particles must be 20 J/g or more. The crystal melting enthalpy is suitably 23 J/g or more. On the other hand, the crystal melting enthalpy is usually 60 J/g or less.

The limit viscosity of the aforementioned polyester must be in the range of 0.9~1.5dl/g. The limiting viscosity of the aforementioned polyester is suitably 1.0 dl/g or more, and more suitably 1.05 dl/g or more. On the other hand, the limiting viscosity of the aforementioned polyester is suitably 1.4 dl/g or less, and more suitably 1.3 dl/g or less.

As long as it does not hinder the effect of the present invention, the polyester resin may contain other additives, such as coloring agents such as dyes or pigments, stabilizers such as ultraviolet absorbers, antistatic agents, flame retardants, Flame retardant auxiliary, lubricant, plasticizer, inorganic filler, etc. Aforementioned The content of these additives in the polyester resin is preferably 10% by mass or less, and more preferably 5% by mass or less.

The manufacturing method of the aforementioned polyester resin particles is not particularly limited, and the above method as the method of manufacturing the first particles is preferable, that is, terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ring The ethylene oxide adduct and the above-mentioned polyhydric ester are melt-kneaded and then subjected to polycondensation and cut to obtain intermediate particles, after which the intermediate particles are solid-phase polymerized.

When an anti-coloring agent is used in the above-mentioned polycondensation, for example, a phosphoric acid compound including phosphorous acid or the ester may be used, and these may be used alone or in combination of two or more kinds. Examples of the phosphoric acid compound include phosphorous acid, phosphite, phosphoric acid, trimethyl phosphate, and triphenyl phosphate. The use amount of the anti-coloring agent is preferably in the range of 80 to 1000 ppm relative to the total of the dicarboxylic acid component and the diester component. In addition, in order to suppress the coloration caused by the thermal decomposition of the polyester, it is preferable to add a cobalt compound such as cobalt acetate. The usage amount is 100 to 100% of the total amount of the dicarboxylic acid component and the diester component. It is better in the range of 1000 ppm.

[Examples]

Hereinafter, the present invention will be described in more detail by examples, but the present invention is not limited by these examples.

(1) Ultimate viscosity

The equal mass mixture of phenol and tetrachloroethane was used as the solvent, and the limit viscosity of the polyester was measured at a temperature of 30°C.

(2) Glass transition temperature (Tg), crystal melting enthalpy (△Hm) and semi-crystallization time

The glass transition temperature (Tg) and crystal melting enthalpy (ΔHm) of polyester (particles after solid-phase polymerization) were measured using a differential scanning calorimeter (TA Q2000 model manufactured by TA Instruments) at a temperature increase rate of 10° C./min. Still, the glass transition temperature (Tg) is obtained by heating the polyester (particles after solid-phase polymerization) from normal temperature (20°C) to 280°C at a heating rate of 10°C/min, and then rapidly cooling to -50°C/min After obtaining the amorphous particles at 20°C, the data at the time of temperature increase at a temperature increase rate of 10°C/min were calculated again.

Using a differential scanning calorimeter (TA Q2000 model manufactured by TA Instruments), the polyester (particles after solid-phase polymerization) was heated from normal temperature (20°C) to 280°C at a heating rate of 10°C/min, and then at -50°C After cooling to 20°C per minute to obtain amorphous particles, the temperature was raised again to 10°C per minute to a temperature above the melting point (280°C). From the curve drawn by the heat against the temperature at this time, the temperature of the heat generation peak accompanying crystallization (crystallization peak temperature) can be obtained. The polyester melted at 280°C was rapidly cooled to the aforementioned peak temperature at a temperature decrease rate of -50°C/min, and then maintained at the aforementioned crystallization peak temperature to perform isothermal crystallization. By plotting the cumulative heat against the time at this time, by measuring the time after reaching the crystallization peak temperature until the calorific value due to isothermal crystallization reaches 1/2 of the total calorific value, the half Crystallization time (seconds). FIG. 1 is a diagram showing a method of obtaining a semi-crystallization time.

(3) Resin color (b value)

According to ASTM-D2244 (color scale system 2), the resin color (b value) of the polyester resin particles was measured using a color measuring color difference meter "ZE-2000" manufactured by Nippon Denshoku Industries Co., Ltd.

(4) Resin pressure

Using an extrusion blow molding machine ("Model MSE-40E" manufactured by Tahara), the maximum temperature of the cylinder is 290 °C, the die temperature is 250 °C, the forming cycle is 15 seconds, the screw rotation number is 22 rpm, and the mold temperature is 20 °C. Under the conditions, it was extruded and blow-molded to form a transparent plastic bottle container with a volume of 220 mL (27.5 g ± 0.5 g). The resin pressure applied to the mold at the time of forming the bottle was measured.

(5) Shock resistance

Add 220ml of water to the polyester hollow container and cover the screw cap, and repeatedly fall from the height of 1.5m towards the concrete floor until the hollow container breaks. The impact resistance was evaluated by the number of drops when the hollow container was broken.

Example 1 〔Melting polymerization〕

Production of 100.0 parts by mass of terephthalic acid, 38.1 parts by mass of ethylene glycol and cyclohexane-1,4-dimethanol [CHDM, cis-trans mixture ratio (cis/trans) system 30/70] 13.0 parts by mass of slurry, to which 0.012 parts by mass of germanium dioxide, 0.012 parts by mass of phosphorous acid and cobalt acetate are added 0.043 parts by mass. The slurry was heated to a temperature of 250° C. under pressure (absolute pressure 0.25 MPa) to perform an esterification reaction, thereby producing a low polymer. Next, the obtained low polymer was transferred to a polycondensation polymerization tank, where neopentyl alcohol-[[((3,5-di-tert- Butyl-4-hydroxyphenyl) propionate] 0.024 parts by mass, and 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2 as an anti-coloring agent ,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5]undecane 0.048 parts by mass. Under a reduced pressure of 1 hPa, the aforementioned low polymer was melt-condensed and polymerized at a temperature of 280° C. to produce a polyester resin with an ultimate viscosity of 0.70 dl/g. After the resulting polyester resin is extruded into a strand shape from a nozzle and water-cooled, it is cut into a cylindrical shape (diameter about 2.5 mm and length about 2.5 mm) to obtain intermediate particles of the polyester resin.

[Crystallization of intermediate particles]

The intermediate particles of the polyester resin obtained in the above manner were put into a rotary vacuum solid-phase polymerization device, dried at 90°C for 24 hours at 1 hPa, and then crystallized at 160°C for 10 hours.

〔Solid Phase Polymerization〕

Subsequent to the above crystallization, solid phase polymerization was performed at 200°C for 38 hours at 1 hPa to obtain polyester resin particles (solid phase polymerized particles) containing copolymerized polyester. When the limit viscosity of the copolymerized polyester was measured by the aforementioned method, it was 1.15 dl/g. In addition, when the b value of the obtained solid-phase polymerized particles was measured by the aforementioned method, it was -1.10. When the ratio of monomer components constituting the copolymerized polyester was confirmed by ¹ H-NMR spectroscopy (apparatus: "JNM-GX-500 type" manufactured by Nippon Electronics Co., Ltd., solvent: heavy hydrogenated trifluoroacetic acid), it was terephthalic acid Formic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 82.8: 14.2: 3.0 (mole ratio), and the content of the unit derived from the polyester is 0.025% by mass. Table 1 shows the Tg, ΔHm, and semi-crystallization time of the copolymerized polyester of the polyester resin particles measured using a differential scanning calorimeter according to the aforementioned method.

〔Forming of extruded and blow molded PET bottles〕

Using the polyester resin pellets obtained in the above manner, a cylindrical bort bottle was manufactured by the method described in "(4) Resin Press". The resin pressure at this time was 21.2 MPa. The transparency of the mouth portion of the obtained cylindrical cylindrical bottle was visually evaluated. In addition, the cylindrical shape special bottle was evaluated according to the method described in "(5) Shock resistance". The results are shown in Table 1.

Example 2

Polyester resin pellets were produced in the same manner as in Example 1, except that the addition amount of the polyester with respect to 100 parts by mass of the low polymer was changed to 0.009 parts by mass and the addition amount of the coloring preventing agent was changed to 0.019 parts by mass. The pellets were used to make cylindrical bottes, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the obtained copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 82.6: 14.5: 2.9 (Mo Ear ratio), the content of the unit derived from the polyester is 0.010 mass %.

Example 3

Except that no colorant was not added to the low polymer, polyester resin pellets were produced in the same manner as in Example 1, and the pellets were used to make cylindrical bort bottles, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 80.9: 16.0: 3.1 (Mo Ear ratio), the content of the unit derived from the polyester is 0.025% by mass.

Example 4

Polyester resin pellets were produced and used in the same manner as in Example 1, except that the addition amount of the polyester with respect to 100 parts by mass of the low polymer was changed to 0.005 parts by mass while no anti-coloring agent was added to the low polymer. The pellets were used to make cylindrical bottes, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the obtained copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 83.2: 14.0: 2.8 (Mo Ear ratio), the content derived from the unit of the polyester is 0.005% by mass.

Example 5

In addition to using a slurry and phase composed of 100.0 parts by mass of terephthalic acid, 35.5 parts by mass of ethylene glycol, and 18.3 parts by mass of cyclohexane-1,4-dimethanol The amount of addition of the polyester of 100 parts by mass of the low polymer was changed to 0.009 parts by mass, and the coloring agent was not added to the low polymer. Polyester resin pellets were produced in the same manner as in Example 1 and rounded using the pellets. Cylindrical Bao Te bottle, at the same time to carry out such evaluation. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 77.1: 20.0: 2.9 (Mo Ear ratio), the content of the unit derived from the polyester is 0.010% by mass.

Example 6

A polyester resin was produced in the same manner as in Example 5 except that a slurry composed of 100.0 parts by mass of terephthalic acid, 42.3 parts by mass of ethylene glycol, and 4.6 parts by mass of cyclohexane-1,4-dimethanol was used. Pellets, and use the pellets to make cylindrical bort bottles, and perform such evaluations at the same time. The results are shown in Table 1. The ratio of the monomer components constituting the obtained copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 92.0: 5.0: 3.0 (Mo Ear ratio), the content of the unit derived from the polyester is 0.010% by mass.

Example 7

Except for using a slurry composed of 100.0 parts by mass of terephthalic acid, 38.1 parts by mass of ethylene glycol, and 13.0 parts by mass of cyclohexane-1,4-dimethanol, the time for solid phase polymerization was changed to 100 hours. Example 5 Polyester resin pellets were manufactured in the same way, and the pellets were used to make cylindrical bolsters Bottle, and conduct such evaluations at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 83.1: 14.0: 2.9 (Mo Ear ratio), the content of the unit derived from the polyester is 0.010% by mass.

Example 8

Except for using a slurry consisting of 100.0 parts by mass of terephthalic acid, 38.1 parts by mass of ethylene glycol, and 13.0 parts by mass of cyclohexane-1,4-dimethanol, the time for solid phase polymerization was changed to 18 hours. In Example 5, polyester resin pellets were produced in the same manner, and the pellets were used to make cylindrical bort bottles, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 83.1: 14.0: 2.9 (Mo Ear ratio), the content of the unit derived from the polyester is 0.010% by mass.

Example 9

A polyester was produced in the same manner as in Example 1 except that a slurry composed of 100.0 parts by mass of terephthalic acid, 42.6 parts by mass of ethylene glycol, and 11.4 parts by mass of 2 mol of an adduct of bisphenol A ethylene oxide was used. Resin pellets, and the pellets were used to make cylindrical bort bottles, and the evaluations were carried out at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: bisphenol A ethylene oxide Unit of 2 mol adduct: diethylene glycol = 100.0: 92.1: 5.0: 2.9 (mole ratio), and the content of the unit derived from the polyester is 0.010% by mass.

Example 10

A polyester was produced in the same manner as in Example 1, except that a slurry composed of 100.0 parts by mass of terephthalic acid, 43.5 parts by mass of ethylene glycol, and 6.85 parts by mass of an adduct of 2 mol of bisphenol A ethylene oxide was used. Resin pellets, and the pellets were used to make cylindrical bort bottles, and the evaluations were carried out at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: bisphenol A ethylene oxide 2 mol adduct unit: diethylene glycol = 100.0: 94.1: 3.0: 2.9 (Molar ratio), the content of the unit derived from the polyvalent ester is 0.010% by mass.

Comparative example 1

Intermediate particles were obtained in the same manner as in Example 1. The glass transition temperature and resin color of the obtained intermediate particles were measured. In addition, the intermediate particles were subjected to extrusion molding and blow molding in the same manner as in Example 1. The results are shown in Table 1. The ratio of the monomer components constituting the intermediate particles is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 82.9: 14.2: 2.9 (molar ratio) The content of the unit derived from the polyester is 0.025% by mass. In addition, when the above-mentioned intermediate particles are subjected to extrusion molding and blow molding, the container cannot be obtained because the parison is stretched.

Comparative example 2

Polyester resin pellets were produced and used in the same manner as in Example 1, except that the addition amount of the polyester with respect to 100 parts by mass of the low polymer was changed to 0.048 parts by mass, and that no colorant was not added to the low polymer. The pellets were used to make cylindrical bottes, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 82.8: 14.2: 3.0 (Mo Ear ratio), the content of the unit derived from the polyester is 0.050% by mass.

Comparative Example 3

The polyester resin pellets were produced in the same manner as in Example 1, except that the polyester and the colorant were not added to the low polymer, and the pellets were used to make cylindrical bort bottles, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol: diethylene glycol = 100.0: 82.2: 15.0: 2.8 (mole ratio). Still, when the polyester resin particles (solid-phase polymer particles) are subjected to extrusion molding and blow molding, the parison cannot be obtained because the parison is stretched.

Comparative Example 4

In addition to the use of a slurry consisting of 92.0 parts by mass of terephthalic acid, 8.0 parts by mass of isophthalic acid (IPA) and 44.4 parts by mass of ethylene glycol, and the amount of addition of a polyester relative to 100 parts by mass of the low polymer Change to Except for 0.009 parts by mass, polyester resin pellets were produced in the same manner as in Example 1, and the pellets were used to make cylindrical bort bottles, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: isophthalic acid unit: ethylene glycol unit: diethylene glycol = 92.0: 8.0: 96.9: 3.1 (mole ratio), derived from The content in the unit of the polyester is 0.010% by mass.

Comparative example 5

In addition to using a slurry composed of 100.0 parts by mass of terephthalic acid, 38.1 parts by mass of ethylene glycol, and 8.32 parts by mass of 1,4-butanediol (BD), and a polyester that is 100 parts by mass relative to the low polymer The addition amount of was changed to 0.009 parts by mass, and polyester resin pellets were produced in the same manner as in Example 1, and the pellets were used to make cylindrical bort bottles, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-butanediol: diethylene glycol=100.0: 83.0: 14.0: 3.0 (mole ratio) , The content of the unit derived from the polyester is 0.010% by mass.

Comparative Example 6

Except that no polyester was added, polyester resin pellets were produced in the same manner as in Example 1, and the pellets were used to make a cylindrical bott bottle, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol: diethylene glycol = 100.0: 80.0: 17.0: 3.0 (Morby). Still, when the polyester resin particles (solid-phase polymer particles) are subjected to extrusion molding and blow molding, the parison cannot be obtained because the parison is stretched.

Comparative Example 7

A slurry consisting of 100.0 parts by mass of terephthalic acid and 44.8 parts by mass of ethylene glycol was prepared, and 0.010 parts by mass of germanium dioxide, 0.010 parts by mass of phosphorous acid, and 0.010 parts by mass of cobalt acetate were added to the slurry. This slurry was heated to a temperature of 250° C. under pressure (absolute pressure 2.5 kg/cm ² ), and an esterification reaction was performed until the esterification rate became 95% to produce a low polymer. Next, the obtained low polymer was transferred to a polycondensation polymerization tank with a capacity of 5 m ³ , and the low polymer was melt-condensed and polymerized at a temperature of 270° C. under a reduced pressure of 0.1 Torr, resulting in a synthesis limit viscosity of 0.70 dl/g Polyester. After extruding the obtained polyester into a strand shape from a nozzle and cooling it with water, it was cut into a cylindrical shape (diameter about 2.5 mm and length about 2.5 mm) to obtain pellets of polyester (A).

A slurry composed of 100.0 parts by mass of terephthalic acid, 17.8 parts by mass of ethylene glycol, and 62.5 parts by mass of 1,4-cyclohexanedimethanol (cis:trans mixing ratio 30:70) was prepared here 0.015 parts by mass of germanium dioxide, 0.010 parts by mass of phosphorous acid, and 0.010 parts by mass of cobalt acetate were added. This slurry was heated to a temperature of 250° C. under pressure (absolute pressure 2.5 kg/cm ² ), and an esterification reaction was performed until the esterification rate became 95% to produce a low polymer. Next, the obtained low polymer was transferred to a polycondensation polymerization tank with a capacity of 5 m ³ , and the low polymer was melt-condensed and polymerized at a temperature of 270° C. under a reduced pressure of 0.1 Torr to produce a limiting viscosity of 0.70 dl/g. Polyester. After extruding the obtained polyester into a strand shape from a nozzle and cooling it with water, it was cut into a cylindrical shape (diameter about 2.5 mm and length about 2.5 mm) to obtain pellets of polyester (B).

The above-mentioned pellets of polyester (A) and polyester (B) are blended so that the mass ratio (A/B) becomes 70/30, and further 100 mass relative to the total of polyester (A) and polyester (B) Parts, adding neopentaerythritol-poly[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] as a polyester 0.024 parts by mass and 3,9 as an anti-coloring agent -Bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5] eleven 0.048 parts by mass of alkane was premixed and supplied to a twin-screw extruder ("TEM-48SS" manufactured by Toshiba Machine Co., Ltd.). The cylinder temperature of the extruder was set to 330°C, the mold temperature was set to 320°C, the melt-kneading was carried out at a vacuum pressure of 700 mmHg (absolute pressure 60 mmHg) at an exhaust port, and an extrusion amount of 150 kg/hr and extruded into strands ( strand). When the molten resin is directly measured with a thermometer at the die outlet of the extruder, the resin temperature is 332°C. The extruded strand was immediately water-cooled, and then cut into a cylindrical shape (approximately 2.5 mm in diameter and approximately 2.5 mm in length) to obtain intermediate particles of the polyester resin composition.

The intermediate particles of the polyester resin composition obtained in the above manner were put into a rotary vacuum solid-phase polymerization device, and dried at 90°C for 24 hours under a reduced pressure of 0.01 Torr, followed by crystallization at 160°C for 10 hours Change.

Following the above-mentioned crystallization, the solid phase polymerization was carried out at 200° C. under a reduced pressure of 0.01 Torr for 38 hours to obtain solid phase polymer particles of the polyester resin composition. Use the obtained particles to make cylindrical bottes, and at the same time Make these evaluations. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexane dimethanol unit: diethylene glycol = 100.0: 82.8: 14.2: 3.0 (Mo Ear ratio), the content of the unit derived from the polyester is 0.025% by mass.

Comparative Example 8

Comparative Example 7 was used except that a slurry consisting of 100.0 parts by mass of terephthalic acid, 37.3 parts by mass of ethylene glycol, and 31.8 parts by mass of 2 mol of an adduct of bisphenol A ethylene oxide was used. Polyester resin pellets were produced in the same manner, and the pellets were used to make cylindrical bort bottles, and these evaluations were performed at the same time. The results are shown in Table 1. The ratio of monomer components constituting the resulting copolymerized polyester is terephthalic acid unit: ethylene glycol unit: bisphenol A ethylene oxide 2 mol adduct unit: diethylene glycol = 100.0: 92.0: 5.0: 3.0 (Molar ratio), the content of the unit derived from the polyvalent ester is 0.010% by mass.

The polyester resin particles of the present invention have a resin pressure of 18 to 23 MPa during extrusion blow molding, have a moderate melt viscosity, and are excellent in sag resistance. In addition, the molded product obtained by using these particles has good impact resistance and color tone. On the other hand, when the intermediate particles obtained after the melt-condensation polymerization are subjected to extrusion blow molding (Comparative Example 1), the parison is not stretched, and a container cannot be obtained. When no polyester is added (Comparative Examples 3 and 6), the parison is not only stretched out and the outside of the container cannot be obtained, and the color tone of the resulting resin is bad. On the other hand, if the amount of the polyester added is too large (Comparative Example 2), the impact resistance of the resulting container will be insufficient. If the copolymerization component is isophthalic acid (Comparative Example 4) or 1,4-butanediol (Comparative Example 5), the impact resistance of the resulting container will be insufficient. When the low polymer is melt-kneaded and polycondensed to obtain two kinds of particles, and then the two kinds of particles are melt-kneaded together with the polyester and then subjected to solid-phase polymerization (Comparative Examples 7 and 8), the resulting molded product The transparency will be insufficient.

As confirmed in the above examples, by adding a specified amount of polyhydric ester during melt polycondensation, the polyhydric ester is a carboxylic acid ester of a polyhydric alcohol of more than three valences and the carboxylic acid system has a hindered phenolic group, thus forming When the polyester resin particles are stretched, the sag resistance will be improved, and at the same time, a molded product with good impact resistance and color tone can be obtained.

Claims (3)

A polyester resin particle characterized by terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide adduct, and polyester by melt-kneading to condense and then solidify The polyester resin particles obtained by phase polymerization, the polyvalent ester is a carboxylic acid ester of a polyvalent alcohol with a trivalent or higher, and the carboxylic acid has a hindered phenol group, and the dicarboxylic acid unit in the polyester is mainly composed of p-benzene It is composed of dicarboxylic acid units. The diol units in the polyester are mainly composed of ethylene glycol units, cyclohexane dimethanol units or units derived from bisphenol A ethylene oxide adducts. The total content of glycol units is 75-98 mol% of ethylene glycol units, and the content of cyclohexanedimethanol units and units derived from bisphenol A ethylene oxide adduct is 2-25 mols %, the content of the component derived from the polyester in the polyester resin is 0.005 to 0.04% by mass, and the limiting viscosity of the polyester is 0.9 to 1.5 dl/g. A molded product formed by extrusion blow molding using the granules according to claim 1. A method for producing polyester resin particles as claimed in claim 1, which comprises melting terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide adduct, and the foregoing polyester by melting After kneading and polycondensation and cutting to obtain intermediate particles, the intermediate particles are solid-phase polymerized.

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