JP2016124966A - Mixed pellet containing pellets of polyester and resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixed pellet comprising pellets of polyester that can produce a molded article having good chemical resistance and hardly causing a reduction in impact resistance after a long period of time and to provide a resin composition comprising pellets of polyester.SOLUTION: The mixed pellet contains a pellet of a polyester (A) and a pellet of a polyester (B). The polyester (A) is composed mainly of: a dicarboxylic acid unit composed mainly of a terephthalic acid unit; and a diol unit composed mainly of an ethylene glycol unit and a cyclohexanedimethanol unit in a molar ratio (ethylene glycol/cyclohexanedimethanol) of 75/25 to 98/2 and the intrinsic viscosity of the polyester (A) is 0.85 to 1.5 dl/g. The polyester (B) is composed mainly of: a dicarboxylic acid unit composed mainly of a terephthalic acid unit and an isophthalic acid unit in a molar ratio (terephthalic acid/isophthalic acid) of 80/20 to 98/2; and a diol unit composed mainly of an ethylene glycol unit and the intrinsic viscosity of the component (B) is 0.8 to 1.5 dl/g. The blending ratio (A/B) of the pellet of the polyester (A) and the pellet of the polyester (B) is 5/95 to 50/50.SELECTED DRAWING: None

Description

  The present invention relates to a mixed pellet containing two types of polyester pellets and a resin composition obtained by melt-kneading these pellets. Moreover, this invention relates to the manufacturing method of the said mixing pellet and the said resin composition, and the molded article which consists of the said mixing pellet or the said resin composition.

  Polyesters such as polyethylene terephthalate are excellent in properties such as transparency, mechanical properties, gas barrier properties, and flavor barrier properties. Furthermore, polyester has less concern about residual monomers and harmful additives when formed into molded articles, and is excellent in hygiene and safety. Therefore, polyester has been widely used in recent years as a hollow container for filling juices, soft drinks, seasonings, oils, cosmetics, detergents, etc. as an alternative to vinyl chloride that has been used in the past, taking advantage of these properties. ing.

  As a molding method for producing a hollow molded product made of polyester, a resin melted and plasticized through a die orifice is extruded as a cylindrical parison, and the parison is sandwiched between molds while it is in a softened state. An extrusion blow molding method is known in which molding is performed by blowing a fluid. Compared with the injection blow molding method, this method is simpler and does not require advanced technology for the production and molding of the mold. Suitable for varieties and small volume production. In addition, there is an advantage that it is possible to manufacture a molded product having a complicated shape having a thin object, a deep object, a large object, a handle, and the like.

  When a general-purpose polyester is extrusion blow molded, the polyester may crystallize and whiten when blown, and the resulting molded product may have insufficient transparency. In order to prevent such whitening of polyester, polyesters obtained by copolymerizing polyethylene terephthalate with other monomer units have been proposed (for example, Patent Documents 1 and 2), and are used as raw materials for extrusion blow molding. .

  By the way, containers for cosmetics and oils are required to have excellent mechanical properties in order to prevent damage due to impact such as dropping in addition to excellent properties such as chemical resistance and gas barrier properties. It is done. However, a container made of a conventional polyester resin becomes fragile as time passes, and may be damaged by an impact such as dropping.

  In Patent Document 1, in a polyester resin in which 50 to 95 mol% of the acid component constituting the polyester is terephthalic acid, 2 to 20 mol% is isophthalic acid, and 80 mol% or more of the glycol component is ethylene glycol, A polyester resin composition containing 0.1 to 1.0% by mass of tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane is described. However, the molded article produced using the polyester resin composition has insufficient impact resistance after a long period of time.

  Patent Document 2 discloses a polyester (A) pellet mainly composed of a terephthalic acid unit and an ethylene glycol unit, and a polyester (B) pellet mainly composed of a terephthalic acid unit, an ethylene glycol unit and a cyclohexanedimethanol unit. After the polyester (A) pellets, the polyester (B) pellets, and the hindered phenolic antioxidant are melt-kneaded and then solid-phase-polymerized pellets obtained by melt polymerization, respectively. The manufacturing method is described. However, the molded product manufactured using the pellets has insufficient chemical resistance.

JP 2012-224836 A JP 2011-252087 A

  The present invention has been made in order to solve the above-mentioned problems, and contains polyester pellets that have good chemical resistance and that can provide a molded product with little reduction in impact resistance after a long period of time. An object of the present invention is to provide a resin composition obtained by melt-kneading mixed pellets and polyester pellets and a method for producing them.

  The above-mentioned problem is a mixed pellet containing polyester (A) pellets and polyester (B) pellets, wherein the polyester (A) is a dicarboxylic acid unit mainly composed of terephthalic acid units, ethylene glycol units and cyclohexane diesters. It is mainly composed of diol units mainly composed of methanol units and a molar ratio (ethylene glycol / cyclohexanedimethanol) of 75/25 to 98/2, and the intrinsic viscosity of polyester (A) is 0.85 to 1.5 dl / a dicarboxylic acid unit in which the polyester (B) is mainly composed of a terephthalic acid unit and an isophthalic acid unit and the molar ratio thereof (terephthalic acid / isophthalic acid) is 80/20 to 98/2, and an ethylene glycol unit. Is mainly composed of diol units mainly composed of The intrinsic viscosity of the tellurium (B) is 0.80 to 1.5 dl / g, and the blending ratio (A / B) of the polyester (A) pellets to the polyester (B) pellets is 5/95 to 50/50. Is solved by providing mixed pellets.

  In the mixed pellet, the polyester (A) is obtained by condensation polymerization of terephthalic acid, ethylene glycol, cyclohexanedimethanol and a polyvalent ester, and the polyvalent ester is a carboxylic acid ester of a trivalent or higher polyol. The carboxylic acid has a hindered phenol group, the content of the unit derived from the polyvalent ester in the polyester (A) is 0.005 to 1.0% by mass, and the polyester (B) Is formed by condensation polymerization of terephthalic acid, isophthalic acid, ethylene glycol and the polyvalent ester, and the content of the unit derived from the polyvalent ester in the polyester (B) is 0.005 to 1. It is suitable that it is 0 mass%.

  A resin composition obtained by melt-kneading the mixed pellet is a preferred embodiment of the present invention. A molded product formed by extrusion blow molding using the mixed pellet is also a preferred embodiment of the present invention.

  The above-mentioned problem is that after melt-kneading terephthalic acid, ethylene glycol and cyclohexanedimethanol, the intermediate pellets are obtained by cutting and then intermediate pellets are solid-phase polymerized to obtain polyester (A) pellets. Obtained, melt-kneaded terephthalic acid, isophthalic acid and ethylene glycol, and then cut to obtain intermediate pellets, and then solid-phase polymerized the intermediate pellets to obtain polyester (B) pellets. Subsequently, the problem can be solved by providing a method for producing the mixed pellet in which the pellet of polyester (A) and the pellet of polyester (B) are mixed. Further, a pellet of polyester (A1) mainly composed of a dicarboxylic acid unit mainly composed of terephthalic acid units and a diol unit mainly composed of ethylene glycol units, a dicarboxylic acid unit mainly composed of terephthalic acid units, and an ethylene glycol unit and After melt-kneading polyester (A2) pellets mainly composed of diol units mainly composed of cyclohexanedimethanol units and having a molar ratio (ethylene glycol / cyclohexanedimethanol) of 0/100 to 80/20 After obtaining intermediate pellets by cutting, polyester (A) pellets are obtained by solid-phase polymerization of the intermediate pellets, and then subjected to condensation polymerization by melt-kneading terephthalic acid, isophthalic acid and ethylene glycol before cutting. The intermediate pellet After that, the intermediate pellets are solid-phase polymerized to obtain polyester (B) pellets, and then the method for producing the mixed pellets in which the polyester (A) pellets and the polyester (B) pellets are mixed is provided. Can also be solved.

  The above problem is that after terephthalic acid, ethylene glycol, cyclohexanedimethanol and the polyvalent ester are subjected to polycondensation and cut to obtain intermediate pellets, the intermediate pellets are solid-phase polymerized to obtain polyester (A) pellets. Obtained and then subjected to condensation polymerization of terephthalic acid, isophthalic acid, ethylene glycol and the polyvalent ester to obtain intermediate pellets, and then solid-phase polymerized the intermediate pellets to obtain polyester (B) pellets. Subsequently, the problem can be solved by providing a method for producing the mixed pellet in which the pellet of polyester (A) and the pellet of polyester (B) are mixed.

  The above-mentioned problem is a resin composition obtained by melt-kneading polyester (A) pellets and polyester (B) pellets, wherein the polyester (A) is a dicarboxylic acid unit mainly composed of terephthalic acid units, and ethylene glycol. Units and cyclohexanedimethanol units are mainly composed of diol units having a molar ratio (ethylene glycol / cyclohexanedimethanol) of 75/25 to 98/2, and the intrinsic viscosity of the polyester (A) is 0.85 to A dicarboxylic acid unit of 1.5 dl / g, in which the polyester (B) is mainly composed of terephthalic acid units and isophthalic acid units, and their molar ratio (terephthalic acid / isophthalic acid) is 80/20 to 98/2, As well as diol units mainly composed of ethylene glycol units, The intrinsic viscosity of the reester (B) is 0.80 to 1.5 dl / g, and the blending ratio (A / B) of the polyester (A) pellets to the polyester (B) pellets is 5/95 to 50/50. It is also solved by providing a resin composition.

  In the resin composition, the polyester (A) is obtained by condensation polymerization of terephthalic acid, ethylene glycol, cyclohexanedimethanol and a polyvalent ester, and the polyvalent ester is a carboxylic acid ester of a trivalent or higher polyol. The carboxylic acid has a hindered phenol group, the content of the unit derived from the polyvalent ester in the polyester (A) is 0.005 to 1.0% by mass, and the polyester (B ) Is obtained by condensation polymerization of terephthalic acid, isophthalic acid, ethylene glycol and the polyvalent ester, and the content of the unit derived from the polyvalent ester in the polyester (B) is 0.005 to 1. It is suitable that it is 0.0 mass%.

  A molded article formed by extrusion blow molding using the resin composition is a preferred embodiment of the present invention.

  The above-mentioned problem is that after melt-kneading terephthalic acid, ethylene glycol and cyclohexanedimethanol, the intermediate pellets are obtained by cutting and then intermediate pellets are solid-phase polymerized to obtain polyester (A) pellets. Obtained, melt-kneaded terephthalic acid, isophthalic acid and ethylene glycol, and then cut to obtain intermediate pellets, and then solid-phase polymerized the intermediate pellets to obtain polyester (B) pellets. Subsequently, the problem can be solved by providing a method for producing the resin composition, in which the pellets of polyester (A) and the pellets of polyester (B) are melt-kneaded. Further, a pellet of polyester (A1) mainly composed of a dicarboxylic acid unit mainly composed of terephthalic acid units and a diol unit mainly composed of ethylene glycol units, a dicarboxylic acid unit mainly composed of terephthalic acid units, and an ethylene glycol unit and After melt-kneading polyester (A2) pellets mainly composed of diol units mainly composed of cyclohexanedimethanol units and having a molar ratio (ethylene glycol / cyclohexanedimethanol) of 0/100 to 80/20 After obtaining intermediate pellets by cutting, polyester (A) pellets are obtained by solid-phase polymerization of the intermediate pellets, and then subjected to condensation polymerization by melt-kneading terephthalic acid, isophthalic acid and ethylene glycol before cutting. The intermediate pellet After that, the intermediate pellet is solid phase polymerized to obtain a polyester (B) pellet, and then the method for producing the resin composition is provided wherein the polyester (A) pellet and the polyester (B) pellet are melt-kneaded. It is also solved by doing.

  The above-mentioned problem is obtained by melt-kneading terephthalic acid, ethylene glycol, cyclohexanedimethanol and the polyvalent ester, and then cutting to obtain an intermediate pellet. Then, the intermediate pellet is solid-phase polymerized to obtain a polyester ( After obtaining the pellets of A), melt-kneading terephthalic acid, isophthalic acid, ethylene glycol and the polyvalent ester, and then cutting to obtain intermediate pellets, followed by solid-phase polymerization of the intermediate pellets It is also possible to obtain a polyester (B) pellet and then provide a method for producing the resin composition, in which the polyester (A) pellet and the polyester (B) pellet are melt-kneaded.

  The molded article made of the mixed pellet or resin composition of the present invention has good chemical resistance, and also has little reduction in impact resistance after a long period of time. Moreover, according to the manufacturing method of this invention, these mixed pellets and resin compositions can be manufactured simply.

It is the figure which showed an example of the DSC curve obtained by measuring a polyester resin composition with a differential scanning calorimeter.

  The mixed pellet of the present invention is a mixed pellet containing a polyester (A) pellet and a polyester (B) pellet, wherein the polyester (A) is a dicarboxylic acid unit mainly composed of a terephthalic acid unit, and an ethylene glycol unit. And a cyclohexanedimethanol unit as a main component, and a molar ratio thereof (ethylene glycol / cyclohexanedimethanol) is mainly composed of diol units of 75/25 to 98/2, and the intrinsic viscosity of the polyester (A) is 0.85 to 1. A dicarboxylic acid unit in which the polyester (B) is mainly composed of terephthalic acid units and isophthalic acid units, and their molar ratio (terephthalic acid / isophthalic acid) is 80/20 to 98/2, and Mainly from diol units mainly composed of ethylene glycol units The intrinsic viscosity of the polyester (B) is 0.80 to 1.5 dl / g, and the blending ratio (A / B) of the polyester (A) pellets to the polyester (B) pellets is 5/95 to 50 / 50.

  The polyester (A) used in the present invention is mainly composed of dicarboxylic acid units mainly composed of terephthalic acid units, ethylene glycol units and cyclohexane dimethanol units, and the molar ratio thereof (ethylene glycol / cyclohexane dimethanol) is 75 / It is mainly composed of diol units of 25 to 98/2 and has an intrinsic viscosity of 0.85 to 1.5 dl / g.

  The content of the terephthalic acid unit in the polyester (A) is usually 80 mol% or more, preferably 90 mol% or more, preferably 95 mol% or more based on the total of the dicarboxylic acid units in the polyester (A). It is more preferable that the dicarboxylic acid unit in the polyester (A) is substantially only a terephthalic acid unit.

  The cyclohexanedimethanol unit in the polyester (A) may be at least one divalent unit selected from 1,2-cyclohexanedimethanol unit, 1,3-cyclohexanedimethanol unit and 1,4-cyclohexanedimethanol unit. That's fine. Among them, the cyclohexanedimethanol unit is a 1,4-cyclohexanedimethanol unit because it is easily available, the polyester (A) is easily made crystalline, and the impact resistance of the resulting molded product is further improved. Preferably there is.

  Although a cis isomer and a trans isomer exist in the cyclohexane dimethanol unit, the ratio of the cis isomer and the trans isomer in the cyclohexane dimethanol unit in the polyester (A) is not particularly limited. Among them, in the cyclohexanedimethanol unit in the polyester (A), the ratio of the cis isomer to the trans isomer is in the range of 0: 100 to 50:50, which makes it easy to make the polyester (A) crystalline. It is preferable from the point that the impact resistance of the obtained molded product is further improved.

  The total content of ethylene glycol units and cyclohexanedimethanol units in the polyester (A) is usually 80 mol% or more, preferably 90 mol% or more, based on the total of diol units in the polyester (A), 95 mol% or more is more preferable. Usually, the polyester (A) contains 1 to 5 mol% of diethylene glycol units, which are by-products during the condensation polymerization reaction, based on the total of diol units in the polyester (A).

  The molar ratio (ethylene glycol / cyclohexanedimethanol) of the ethylene glycol unit to the cyclohexanedimethanol unit in the polyester (A) is 75/25 to 98/2. Production of polyesters with a molar ratio (ethylene glycol / cyclohexanedimethanol) of less than 75/25 is prone to sticking due to resin softening during solid phase polymerization, and the solid phase polymerization temperature cannot be increased. Sexuality decreases. Moreover, the obtained molded product is colored. The molar ratio (ethylene glycol / cyclohexanedimethanol) is preferably 82/18 or more. On the other hand, when the molar ratio (ethylene glycol / cyclohexanedimethanol) exceeds 98/2, the impact resistance and transparency of the obtained molded product are lowered. The molar ratio (ethylene glycol / cyclohexanedimethanol) is preferably 96/4 or less, and more preferably 92/8 or less.

  The total content of terephthalic acid units, ethylene glycol units and cyclohexanedimethanol units in the polyester (A) is preferably at least 80 mol%, more than 90 mol%, based on the total of all structural units in the polyester (A). Is more preferable, and 95 mol% or more is still more preferable. When a polyester having a content of less than 80 mol% is produced, the solidification is likely to cause sticking due to softening of the resin, which may make it difficult to increase the degree of polymerization.

  The polyester (A) is preferably a carboxylic acid ester of a trivalent or higher polyol, and the carboxylic acid further contains a unit derived from a polyvalent ester having a hindered phenol group. Here, the unit derived from a polyvalent ester is one contained in the polyester (A) by polycondensing a polyvalent ester together with terephthalic acid, ethylene glycol and cyclohexanedimethanol. A polyol unit of the polyvalent ester and a carboxylic acid unit having a hindered phenol group are contained in the polyester (A) by a transesterification reaction. The polyol unit is contained in the main chain, branched chain or terminal of the polyester (A). A part of the polyol unit becomes a crosslinking point and acts as a crosslinking agent. On the other hand, a part of the carboxylic acid unit having a hindered phenol group is contained at the terminal of the polyester (A), and a part is contained in the polyester (A) together with the polyol unit in a state bonded to the polyol unit. . As described above, when the unit derived from the polyvalent ester is contained in the polyester (A), the drawdown resistance at the time of extrusion blow molding of the resulting mixed pellet is improved, and the color tone is more excellent. Goods are obtained. The polyvalent ester is preferably a carboxylic acid ester of a trivalent to pentavalent polyol. Examples of the polyvalent ester include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris [2- [3- (3,5- And di-tert-butyl-4-hydroxyphenyl) propanoyloxy] ethyl] hexahydro-1,3,5-triazine-2,4,6-trione.

  As for content of the unit derived from the said polyvalent ester in polyester (A), 0.005-1.0 mass% is preferable. Here, the content of the component derived from the polyvalent ester in the polyester (A) is the total amount of the unit derived from the polyvalent ester incorporated in the polyester chain and the component not incorporated in the polyester chain. is there. When the content of the unit derived from the polyvalent ester is less than 0.005% by mass, the above-described effects may not be obtained. On the other hand, when the content of the unit derived from the polyvalent ester exceeds 1.0% by mass, crosslinking by the unit derived from the polyvalent ester proceeds too much, and the melt viscosity may become too high or the obtained molded product Impact resistance may be reduced. The content of the unit derived from the polyvalent ester is more preferably 0.1% by mass or less, and further preferably 0.04% by mass or less.

  The polyester (A) may have a bifunctional compound unit other than the terephthalic acid unit, the ethylene glycol unit, the cyclohexanedimethanol unit, and the unit derived from the polyvalent ester, if necessary. The content of other bifunctional compound units [the total when two or more units are included] is preferably 20 mol% or less based on the total of all structural units constituting the polyester (A). More preferably, it is 10 mol% or less, and more preferably 5 mol% or less. Other difunctional compound units that can be contained in the polyester (A) include dicarboxylic acid units, diol units, and hydroxycarboxylic acid units, aliphatic bifunctional compound units, and alicyclic 2 units. Either a functional compound unit or an aromatic bifunctional compound unit may be used. For example, aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid and ester-forming derivatives thereof; cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dimer acid Aliphatic dicarboxylic acids such as, or ester-forming derivatives thereof; aliphatic diols such as neopentyl glycol, 1,4-butanediol, 1,5-pentamethylene diol, 1,6-hexamethylene diol, diethylene glycol, dimer diol A divalent structural unit derived from bisphenol A or bisphenol S ethylene oxide adduct; In addition, when polyester (A) contains an isophthalic acid unit, it is preferable that molar ratio (terephthalic acid / isophthalic acid) of a terephthalic acid unit and an isophthalic acid unit exceeds 98/2, and polyester (A) is substantially More preferably, no isophthalic acid is contained.

  As long as the polyester (A) does not inhibit the effects of the present invention, in addition to the terephthalic acid unit, the ethylene glycol unit, the cyclohexanedimethanol, the unit derived from the polyvalent ester, and the other bifunctional compound unit described above, You may have another multifunctional compound unit. Another polyfunctional compound unit is a polyfunctional compound unit derived from a polyfunctional compound having three or more carboxyl groups, hydroxyl groups and / or ester-forming groups thereof. The content of other polyfunctional compound units [the total when two or more units are included] is preferably 1% by mass or less based on the total of all structural units of the polyester (A). More preferably, it is 5 mass% or less. Examples of other polyfunctional compound units include those derived from trimellitic acid, pyromellitic acid, trimesic acid, trimethylolpropane, pentaerythritol, and glycerin.

  Further, the polyester (A) is derived from at least one monofunctional compound such as monocarboxylic acid other than the carboxylic acid having a hindered phenol group, monoalcohol, and ester-forming derivatives thereof, as necessary. You may have another monofunctional compound unit. The other monofunctional compound unit functions as a sealing compound unit and seals molecular chain end groups and / or branched chain end groups in the polyester (A), and excessive crosslinking and gelation of the polyester (A). Prevent occurrence. When the polyester (A) has such other monofunctional compound units, the content of the other monofunctional compound units [the total when two or more types of units are included] of the polyester (A) It is preferably 1 mol% or less, more preferably 0.5 mol% or less, based on the total of all structural units. When the content of the other monofunctional compound unit in the polyester (A) exceeds 1 mol%, the polymerization rate at the time of producing the polyester (A) becomes slow, and the productivity tends to decrease. Examples of other monofunctional compound units include units derived from monofunctional compounds selected from benzoic acid, 2,4,6-trimethoxybenzoic acid, 2-naphthoic acid, stearic acid, and stearyl alcohol. .

  The method for producing the polyester (A) pellets used in the present invention is not particularly limited, but from the viewpoint of further improving the impact resistance of the obtained molded product, terephthalic acid, ethylene glycol, cyclohexanedimethanol and, if necessary, the above-mentioned A method of producing polyester (A) pellets by solid-phase polymerization of the intermediate pellets after the intermediate pellets are obtained by polycondensation by melt-kneading the polyvalent ester and cutting. Hereinafter, this method may be referred to as a random copolymerization method. By such a method, a polyester in which ethylene glycol units and cyclohexanedimethanol units are randomly incorporated in the polyester chain is obtained.

  Specific random copolymerization methods include terephthalic acid or an ester-forming derivative thereof, ethylene glycol, cyclohexanedimethanol, and if necessary, the polyvalent ester, other bifunctional compounds, polyfunctional compounds, monofunctional After performing esterification reaction or transesterification reaction using a reactive compound as a reaction raw material, melt and polycondensate it, and then cut to obtain an intermediate pellet. Then, the intermediate pellet is solid-phase polymerized to obtain a polyester. The method of obtaining the pellet of (A) is mentioned. The reaction raw material can be appropriately added before the esterification reaction or transesterification reaction, or after the reaction.

  The esterification reaction or transesterification reaction is carried out by adding a reaction raw material, a polymerization catalyst, and, if necessary, an additive such as an anti-coloring agent to the reactor, and at an absolute pressure of about 0.5 MPa or less under a normal pressure or a normal pressure. It is preferable to carry out at a temperature of 280 ° C. while distilling off generated water or alcohol.

  The melt polycondensation reaction following the esterification reaction or transesterification reaction is performed by adding additives such as the above-mentioned reaction raw materials, polycondensation catalyst, and coloring inhibitor to the obtained polyester oligomer as necessary. It is preferable to carry out under reduced pressure at a temperature of 260 to 290 ° C. until a polyester having a desired viscosity is obtained. When the reaction temperature of the melt polycondensation reaction is less than 260 ° C., the polymerization activity of the polymerization catalyst is low, and there is a possibility that a polyester having a target degree of polymerization cannot be obtained. On the other hand, when the reaction temperature of the melt polycondensation reaction exceeds 290 ° C., the decomposition reaction easily proceeds, and as a result, there is a possibility that a polyester having a target degree of polymerization cannot be obtained. The melt polycondensation reaction can be performed using, for example, a tank-type batch polycondensation apparatus or a continuous polycondensation apparatus including a biaxial rotating horizontal reactor.

  As the polymerization catalyst used for the condensation polymerization, a compound containing a germanium element, an antimony element, or a titanium element is preferable. As the compound containing antimony element, antimony trioxide, antimony chloride, antimony acetate, etc. are used. As the compound containing germanium element, germanium dioxide, germanium tetrachloride, germanium tetraethoxide, etc. are used. As the compound to be contained, tetraisopropyl titanate, tetrabutyl titanate, or the like is used. Among these, antimony trioxide and germanium dioxide are preferable from the viewpoint of polymerization catalyst activity, physical properties of the resulting polyester, and cost. When a polycondensation catalyst is used, the amount added is preferably in the range of 0.002 to 0.8 mass% based on the mass of the dicarboxylic acid component.

  When using an anti-coloring agent in the above condensation polymerization, for example, a phosphoric acid compound such as phosphorous acid or an ester thereof can be used, which can be used alone or in combination of two or more. Good. Examples of the phosphoric acid compound include phosphorous acid, phosphite, phosphoric acid, trimethyl phosphate, and triphenyl phosphate. It is preferable that the usage-amount of a coloring inhibitor exists in the range of 80-1000 ppm with respect to the sum total of a dicarboxylic acid component and a diester component. Moreover, in order to suppress the coloring by thermal decomposition of polyester (A), it is preferable to add a cobalt compound such as cobalt acetate, and the amount used is in the range of 100 to 1000 ppm with respect to the total of the dicarboxylic acid component and the diester component. More preferably, it is within.

  In the above condensation polymerization, a terephthalic acid ester may be used to form a terephthalic acid unit. The alcohol part of the terephthalic acid ester is not particularly limited, and examples thereof include monools such as methanol and ethanol; polyols such as ethylene glycol and cyclohexanedimethanol which are constituent units of the polyester.

  In the above condensation polymerization, ethylene glycol monoester or diester may be used to form an ethylene glycol unit. The carboxylic acid moiety 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 intrinsic viscosity of the polyester obtained by the melt polycondensation is preferably in the range of 0.4 to 0.9 dl / g from the viewpoint of handleability. When the intrinsic viscosity of the polyester obtained by melt polycondensation is less than 0.4 dl / g, when the polyester is taken out from the reactor, the melt viscosity is too low and it becomes difficult to extrude in the form of a strand or a sheet. Moreover, it becomes difficult to cut into pellets uniformly. Further, when the polyester obtained by melt polycondensation is subjected to solid-phase polymerization, it takes a long time to increase the molecular weight, which may reduce productivity. The intrinsic viscosity of the polyester is more preferably 0.5 dl / g or more, and still more preferably 0.6 dl / g or more. On the other hand, if the intrinsic viscosity of the polyester is higher than 0.9 dl / g, the melt viscosity is too high, so that it may be difficult to take out the polyester from the reactor, or coloring may easily occur due to thermal degradation. is there. The intrinsic viscosity of the polyester is more preferably 0.85 dl / g or less, and still more preferably 0.8 dl / g or less.

  The polyester obtained as described above is extruded into a strand shape, a sheet shape, and the like, cooled, and then cut with a strand cutter, a sheet cutter, or the like to have a shape such as a column shape, an elliptical column shape, a disk shape, or a die shape. Intermediate pellets are produced. The above-described cooling after extrusion can be performed by, for example, a water cooling method using a water tank, a method using a cooling drum, an air cooling method, or the like.

  In order to further increase the degree of polymerization of the intermediate pellet thus obtained, the intermediate pellet is subjected to solid phase polymerization. It is preferable to crystallize a part of the polyester by heating before solid phase polymerization. By doing so, it is possible to prevent the pellets from sticking during solid phase polymerization. The crystallization temperature is preferably 100 to 180 ° C. As a crystallization method, crystallization may be performed in a vacuum tumbler, or crystallization may be performed by heating in an air circulation type heating apparatus. When heating in an air circulation heating device, the internal temperature is preferably 100 to 160 ° C. When heating using an air circulation type heating device, compared with crystallization using a vacuum tumbler, heat conduction is good, so the time required for crystallization can be shortened and the device is also inexpensive. The time required for crystallization is not particularly limited, but is usually about 30 minutes to 24 hours. It is also preferred to dry the pellets at a temperature below 100 ° C. prior to crystallization.

  The temperature of the solid phase polymerization is preferably 170 to 250 ° C. When the temperature of the solid phase polymerization is lower than 170 ° C., the time for the solid phase polymerization becomes long and the productivity may be lowered. The temperature of solid phase polymerization is more preferably 175 ° C. or higher, and further preferably 180 ° C. or higher. On the other hand, when the temperature of the solid phase polymerization exceeds 250 ° C., the pellets may be stuck. The temperature of the solid phase polymerization is more preferably 240 ° C. or lower, and further preferably 230 ° C. or lower. The time for solid phase polymerization is usually about 5 to 70 hours. Moreover, you may coexist the catalyst used by melt polycondensation at the time of solid-phase polymerization.

  The solid phase polymerization is preferably performed under reduced pressure or in an inert gas such as nitrogen gas. Further, it is preferable to carry out solid phase polymerization while moving the pellets by an appropriate method such as a rolling method or a gas fluidized bed method so that no sticking occurs between the polyester pellets. The pressure when solid-state polymerization is performed under reduced pressure is preferably 1 kPa or less.

  On the other hand, from the viewpoint of further improving the chemical resistance of the obtained molded product, pellets of polyester (A1) mainly composed of dicarboxylic acid units mainly composed of terephthalic acid units and diol units mainly composed of ethylene glycol units; Dicarboxylic acid units mainly composed of terephthalic acid units, and diol units mainly composed of ethylene glycol units and / or cyclohexanedimethanol units, and their molar ratio (ethylene glycol / cyclohexanedimethanol) is 0/100 to 80/20 A method of obtaining polyester (A) pellets by melt-kneading the polyester (A2) pellets mainly composed of the above and cutting them to obtain intermediate pellets, followed by solid-phase polymerization of the intermediate pellets. The polyester (A) obtained by such a method is obtained by further solid-phase polymerization of two types of polyesters having different molar ratios of ethylene glycol units and cyclohexanedimethanol units. It is considered that the polyester has a so-called block polymer-like structure obtained by transesterification. Hereinafter, the method may be referred to as a block copolymerization method.

  Polyester (A1) pellets and polyester (A2) pellets are produced in the same manner as the intermediate pellets in the random copolymerization method described above. When the polyester (A1) contains cyclohexanedimethanol units, the molar ratio of ethylene glycol units to cyclohexanedimethanol units (ethylene glycol / cyclohexanedimethanol) is preferably more than 80/20, and the polyester (A1) is substantially It is more preferable that no cyclohexanedimethanol unit is contained.

  In the block copolymerization method, the method for melt-kneading the polyester (A1) pellets and the polyester (A2) pellets is not particularly limited, and any method may be used as long as both are uniformly melted and mixed. A method using a melt kneader such as a single screw extruder, a twin screw extruder, a kneader, a Banbury mixer, or an internal mixer can be employed. From the viewpoint of ease of melt kneading, a method using an extruder such as a single screw extruder or a twin screw extruder is preferably employed. The mixing ratio of the polyester (A1) pellets and the polyester (A2) pellets is appropriately adjusted according to the molar ratio of the ethylene glycol unit and the cyclohexanedimethanol unit in the polyester (A) to be obtained. The temperature at the time of melt-kneading is usually 200 to 350 ° C., and the time for melt-kneading is usually about 2 to 120 minutes. Further, it is preferable to reduce the pressure inside the kneading apparatus when melt kneading, and the vacuum pressure is preferably 400 mmHg or more. Here, the vacuum pressure refers to a differential pressure from the atmospheric pressure. Specifically, the pressure can be reduced from a vent or the like.

  When the polyester (A) containing the polyvalent ester is produced, the polyvalent ester is added during the melt-kneading to produce polyester (A1) pellets, polyester (A2) pellets and the polyvalent ester. Is preferably melt-kneaded. Moreover, you may add additives, such as a coloring inhibitor, in the case of the said melt-kneading.

  The intrinsic viscosity of the polyester resin obtained by melt-kneading the polyester (A1) pellets and the polyester (A2) pellets is 0.4 to 0.9 dl from the viewpoints of handleability, solid-phase polymerization in the next step, and the like. / G is preferable. If the intrinsic viscosity of the polyester resin is less than 0.4 dl / g, the melt viscosity becomes low, it becomes difficult to extrude in the form of a strand or a sheet, and it becomes difficult to uniformly cut into pellets, It takes a long time for solid-phase polymerization and tends to cause a decrease in productivity. The intrinsic viscosity of the polyester resin is more preferably 0.5 dl / g or more, and further preferably 0.6 dl / g or more. On the other hand, polyester resins having an intrinsic viscosity exceeding 0.9 dl / g are not advantageous from the viewpoint of productivity because it is difficult to obtain them by liquid phase polymerization.

  The obtained polyester resin is cut to obtain intermediate pellets, and then the intermediate pellets are solid-phase polymerized to obtain polyester (A) pellets. The method similar to the random copolymerization method mentioned above is employ | adopted for the method of cut | disconnecting a polyester resin, and obtaining an intermediate pellet, and a solid phase polymerization method.

  In the present invention, the intrinsic viscosity of the polyester (A) needs to be in the range of 0.85 to 1.5 dl / g. When the intrinsic viscosity is less than 0.85 dl / g, the drawdown resistance at the time of extrusion blow molding is deteriorated, and the strength, impact resistance and transparency of the obtained molded product are lowered. The intrinsic viscosity is preferably 1.0 dl / g or more, and more preferably 1.05 dl / g or more. On the other hand, when the intrinsic viscosity exceeds 1.5 dl / g, the melt viscosity becomes too high and the melt moldability may be lowered, and the productivity is also lowered. The intrinsic viscosity is preferably 1.4 dl / g or less, and more preferably 1.3 dl / g or less.

  The polyester (A) may contain other additives as long as the effects of the present invention are not impaired. Colorants such as dyes and pigments, stabilizers such as ultraviolet absorbers, antistatic agents, difficulty Examples include flame retardants, flame retardant aids, lubricants, plasticizers, and inorganic fillers. The content of these additives in the polyester (A) is preferably 10% by mass or less, and more preferably 5% by mass or less.

  Hereinafter, the polyester (B) pellets will be described. The polyester (B) used in the present invention is mainly composed of terephthalic acid units and isophthalic acid units, and their molar ratio (terephthalic acid / isophthalic acid) is 80/20 to 98/2, and ethylene glycol. It is mainly composed of diol units mainly composed of units, and has an intrinsic viscosity of 0.80 to 1.5 dl / g.

  The content of ethylene glycol units in the polyester (B) is usually 80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more based on the total of diol units in the polyester (B). preferable. Usually, the polyester (B) contains 1 to 5 mol% of diethylene glycol units, which are by-products during the condensation polymerization reaction, based on the total of diol units in the polyester (B).

  The total content of terephthalic acid units and isophthalic acid units in the polyester (B) is usually 80 mol% or more, preferably 90 mol% or more, based on the total dicarboxylic acid units in the polyester (B), 95 mol% or more is more preferable, and it is further more preferable that the dicarboxylic acid unit in polyester (B) is substantially only a terephthalic acid unit and an isophthalic acid unit.

  The molar ratio of terephthalic acid units to isophthalic acid units (terephthalic acid / isophthalic acid) in the polyester (B) is 80/20 to 98/2. When a polyester having a molar ratio (terephthalic acid / isophthalic acid) of less than 80/20 is produced, it is easy to cause sticking due to softening of the resin during solid phase polymerization, and therefore the solid phase polymerization temperature cannot be increased. Productivity decreases. The molar ratio (terephthalic acid / isophthalic acid) is preferably 85/15 or more. On the other hand, when the molar ratio (terephthalic acid / isophthalic acid) exceeds 98/2, since the melting point of the resin becomes high, it is necessary to increase the molding temperature, and the hue of the molded product deteriorates. The molar ratio (terephthalic acid / isophthalic acid) is preferably 96/4 or less.

  The total content of terephthalic acid units, isophthalic acid units and ethylene glycol units in the polyester (B) is preferably 80 mol% or more, more than 90 mol%, based on the total of all structural units in the polyester (A). More preferred is 95 mol% or more. When a polyester having a content of less than 80 mol% is produced, the solidification is likely to cause sticking due to softening of the resin, which may reduce the productivity.

  The polyester (B) is a carboxylic acid ester of a trivalent or higher polyol, and the carboxylic acid preferably contains a unit derived from a polyvalent ester having a hindered phenol group. Here, the unit derived from a polyvalent ester is one contained in the polyester (B) by polycondensing a polyvalent ester together with terephthalic acid, isophthalic acid and ethylene glycol. When the unit derived from the polyvalent ester is contained in the polyester (B), a molded product with improved color tone and a better color tone can be obtained while extrusion blow molding is improved. What was mentioned above as a polyvalent ester used for preparation of polyester (A) as a polyvalent ester used for preparation of polyester (B) is mentioned.

  As for content of the unit derived from the said polyvalent ester in polyester (B), 0.005-1.0 mass% is preferable. Here, the content of the component derived from the polyvalent ester in the polyester (B) is the total amount of the unit derived from the polyvalent ester incorporated in the polyester chain and the component not incorporated in the polyester chain. is there. When the content of the unit derived from the polyvalent ester is less than 0.005% by mass, the above-described effects may not be obtained. 0.01 mass% or more is suitable for content of the unit derived from the said polyvalent ester, and 0.1 mass% or more is more suitable. On the other hand, when the content of the unit derived from the polyvalent ester exceeds 1.0% by mass, crosslinking by the unit derived from the polyvalent ester proceeds too much, and the melt viscosity may become too high or the obtained molded product Impact resistance may be reduced.

  The polyester (B) may have a bifunctional compound unit other than a terephthalic acid unit, an isophthalic acid unit, an ethylene glycol unit, and a unit derived from the polyvalent ester, if necessary. The content of other bifunctional compound units [the total when two or more units are included] is preferably 20 mol% or less with respect to the total of all structural units constituting the polyester (B). More preferably, it is 10 mol% or less, and more preferably 5 mol% or less. Examples of the other bifunctional compound unit that can be contained in the polyester (B) include those described above as the bifunctional compound unit that can be contained in the polyester (A). In addition, when polyester (B) contains a cyclohexanediol unit, it is preferable that the molar ratio (ethylene glycol / cyclohexanedimethanol) of an ethylene glycol unit and a cyclohexanedimethanol unit exceeds 98/2, and polyester (B) is substantially In particular, it is more preferable not to contain a cyclohexanedimethanol unit.

  As long as the polyester (B) is a range that does not inhibit the effect of the present invention, in addition to the terephthalic acid unit, the isophthalic acid unit, the ethylene glycol unit, the unit derived from the polyvalent ester, and the other bifunctional compound unit described above, You may have another multifunctional compound unit. Another polyfunctional compound unit is a polyfunctional compound unit derived from a polyfunctional compound having three or more carboxyl groups, hydroxyl groups and / or ester-forming groups thereof. The content of other polyfunctional compound units [the total when two or more units are included] is preferably 1% by mass or less based on the total of all structural units of the polyester (B). More preferably, it is 5 mass% or less. As another polyfunctional compound unit, what was mentioned above as a polyfunctional compound unit which can be contained in polyester (A) is mentioned.

  Further, the polyester (B) is derived from at least one monofunctional compound such as monocarboxylic acid other than the carboxylic acid having a hindered phenol group, monoalcohol, and ester-forming derivatives thereof, as necessary. You may have another monofunctional compound unit. The other monofunctional compound unit functions as a sealing compound unit and seals molecular chain end groups and / or branched chain end groups in the polyester (B), and causes excessive crosslinking and gelation of the polyester (B). Prevent occurrence. When the polyester (B) has such other monofunctional compound units, the content of the other monofunctional compound units [the total when two or more units are included] of the polyester (B) It is preferably 1 mol% or less, more preferably 0.5 mol% or less, based on the total of all structural units. When the content of the other monofunctional compound unit in the polyester (B) exceeds 1 mol%, the polymerization rate at the time of producing the polyester (B) becomes slow, and the productivity tends to decrease. As another monofunctional compound unit, what was mentioned above as a monofunctional compound unit which can be contained in polyester (A) is mentioned.

  The method for producing the polyester (B) pellets used in the present invention is not particularly limited, but it is cut after condensation polymerization by melt-kneading terephthalic acid, isophthalic acid, ethylene glycol, and, if necessary, the polyvalent ester. Then, after obtaining intermediate pellets, a method of producing pellets of polyester (B) by solid-phase polymerization of the intermediate pellets is preferred. Specifically, terephthalic acid or an ester-forming derivative thereof, isophthalic acid or an ester-forming derivative thereof, ethylene glycol, and, if necessary, the polyvalent ester, other bifunctional compounds, polyfunctional compounds, monofunctional After performing esterification reaction or transesterification reaction using a reactive compound as a reaction raw material, melt and polycondensate it, and then cut to obtain an intermediate pellet. Then, the intermediate pellet is solid-phase polymerized to obtain a polyester. The method of obtaining the pellet of (B) is mentioned. Each reaction and operation can be performed in the same manner as described above when the polyester (A) pellets are produced by the random copolymerization method. Moreover, what was mentioned above as what is used when manufacturing the pellet of polyester (A) by a random copolymerization method as a polymerization catalyst and additive used for manufacture of the pellet of polyester (B) is mentioned.

  In the present invention, the intrinsic viscosity of the polyester (B) needs to be in the range of 0.8 to 1.5 dl / g. When the intrinsic viscosity is less than 0.8 dl / g, the drawdown resistance at the time of extrusion blow molding is deteriorated, and the strength, impact resistance and transparency of the obtained molded product are lowered. The intrinsic viscosity is preferably 0.85 dl / g or more, more preferably 0.9 dl / g or more, and further preferably 1.05 dl / g or more. On the other hand, when the intrinsic viscosity exceeds 1.5 dl / g, the melt viscosity becomes too high and the melt moldability may be lowered, and the productivity is also lowered. The intrinsic viscosity is preferably 1.4 dl / g or less, and more preferably 1.3 dl / g or less.

  The polyester (B) may contain other additives as long as the effects of the present invention are not impaired, and those described above as additives contained in the polyester (A) as such additives. Can be mentioned. The content of these additives in the polyester (B) is preferably 10% by mass or less, and more preferably 5% by mass or less.

  The polyester (A) pellets and polyester (B) pellets obtained as described above are mixed to obtain mixed pellets. The mixing ratio (A / B) of the polyester (A) pellets and the polyester (B) pellets in the mixed pellets is 5/95 to 50/50. When the said compounding ratio (A / B) is less than 5/95, the impact resistance of the obtained molded article falls. The blending ratio (A / B) is preferably 10/90 or more. On the other hand, when the compounding ratio (A / B) of the polyester (A) pellets and the polyester (B) pellets exceeds 50/50, the chemical resistance decreases. The blending ratio (A / B) is preferably 40/60 or less, and more preferably 30/70 or less.

  The total content of the polyester (A) pellets and the polyester (B) pellets in the mixed pellets of the present invention is usually 50% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more. Is preferred.

  The mixed pellets of the present invention may contain components other than the polyester (A) pellets and the polyester (B) pellets as long as the effects of the present invention are not impaired. The content of other components is usually 50% by mass or less, preferably 30% by mass or less, and more preferably 20% by mass or less. Examples of other components include scraps such as burrs generated when the mixed pellets of the present invention are molded, and mechanically recycled materials obtained by mechanically grinding molded products.

  The method for mixing the polyester (A) pellets and the polyester (B) pellets is not particularly limited, and a method using a tumbler mixer, a universal mixing stirrer, or the like generally used for mixing a resin and a mechanically recycled material. Can be mentioned.

  A resin composition obtained by melt-kneading the mixed pellet is a preferred embodiment of the present invention. The resin composition is obtained by melting and kneading the mixed pellets of the present invention, so that the polyester (A) and the polyester (B) are compatible, and has excellent chemical resistance and after a long period of time. There is little decrease in impact resistance. Examples of the melt-kneading method of the mixed pellet include the method described above as a method of melt-kneading the polyester (A1) pellet and the polyester (A2) pellet. The temperature at the time of melt kneading is usually 200 to 350 ° C., and the time for melt kneading is usually about 2 to 120 minutes.

  A resin composition obtained by melt-kneading a polyester (A) pellet and a polyester (B) pellet at a blending ratio (A / B) of 5/95 to 50/50 is also preferable. Thus, the resin composition obtained by directly melting and kneading the polyester (A) pellets and the polyester (B) pellets also has the same performance as the above-described resin composition obtained by melting and kneading the mixed pellets. . The total content of the polyester (A) and the polyester in the resin composition obtained by melt-kneading the polyester (A) pellets and the polyester (B) pellets is usually 50% by mass or more and 70% by mass. The above is preferable, and 80% by mass or more is more preferable. Further, the resin composition may contain scraps such as trim generated when molded, as long as the effects of the present invention are not impaired, and the content thereof is usually 50% by mass or less. Yes, 30 mass% or less is suitable, and 20 mass% or less is more suitable.

  A molded product can be obtained by melt-molding these resin compositions. The molding method is not particularly limited, and various melt molding methods such as extrusion molding and injection molding can be employed. Further, the melt molded product can be further subjected to secondary processing to obtain a molded product. The temperature of the resin composition at the time of extrusion molding is preferably set to a temperature within the range of (melting point of polyester resin + 10 ° C.) to (melting point of polyester resin + 70 ° C.), and (melting point of polyester resin + 10 ° C.) to (polyester). More preferably, the temperature is within the range of the melting point of the resin + 40 ° C. By extruding at a temperature relatively close to the melting point, drawdown can be suppressed.

  Using the resin composition, for example, when producing a sheet or film by extrusion molding such as a T-die method or an inflation method, there is no occurrence of drawdown, neck-in, film swaying, unmelted fluff, and high quality. Sheet or film can be produced with high productivity. And when performing secondary processing such as thermoforming using the sheet or film thus obtained, when forming deep-drawn molded products and large molded products, the drawdown is small, The degree of crystallization is good, and it is difficult to cause thickness unevenness or whitening in the step of applying an external force such as vacuum suction or compressed air, and the desired molded product can be obtained with good formability.

  Among extrusion moldings, it is extrusion blow molding that is particularly suitable for using the resin composition. The method of extrusion blow molding is not particularly limited, and can be performed in the same manner as conventionally known extrusion blow molding methods. For example, the resin composition is melt-extruded to form a cylindrical parison, which is sandwiched between blow molds while the parison is in a softened state, and a gas such as air is blown to form the parison into a mold cavity shape. It can be performed by a method of inflating to a predetermined hollow shape along. When the resin composition is used, the drawn parison has good drawdown properties, and a hollow molded product can be produced with high productivity.

  The molded product thus obtained is excellent in chemical resistance and also has little reduction in impact resistance after a long period of time. In addition, it has excellent transparency, good appearance and color tone, and excellent properties such as gas barrier properties, flavor barrier properties, moisture resistance, and chemical resistance, and therefore can be used in various applications. Moreover, it can also be set as the molded article which has a laminated structure with other thermoplastic resins.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by this Example.

(1) Intrinsic viscosity Intrinsic viscosity was measured at a temperature of 30 ° C using an equal mass mixture of phenol and 1,1,2,2-tetrachloroethane as a solvent.

(2) Melting enthalpy (ΔHm)
The melting enthalpy was measured using a differential scanning calorimeter (TA Q2000 model manufactured by TA Instruments) at a heating rate of 10 ° C./min.

(3) Production of bottle Using an extrusion blow molding device (“MSE-40E type” manufactured by Tahara Co., Ltd.), the maximum cylinder temperature is 290 ° C., the die temperature is 250 ° C., the molding cycle is 15 seconds, the screw rotation speed is 22 rpm, and the extrusion resin pressure is A transparent bottle (27.5 g ± 0.5 g) having a volume of 220 mL was molded at 19-25 MPa and a mold temperature of 20 ° C.

(4) Drop test After putting water (water temperature 20-25 ° C.) so that the total weight is 263 g ± 0.5 g in a bottle immediately after molding, it is passed through a vertically installed cylinder of 10 cm in diameter. From 100 cm in length, it was dropped alternately on a horizontal concrete surface and a concrete surface inclined 45 degrees. The number of cycles until the bottle was cracked or cracked (the bottle was dropped twice in total, once on the horizontal surface and once on the 45 ° slope) was measured. Up to 20 cycles were repeated. A drop test of five bottles was performed per composition, and the average value was defined as the bottle drop strength. Further, after the molded bottle was stored in a thermostat at 50 ° C. for 140 hours or 210 hours and subjected to an acceleration test, a drop test was performed by the above method to determine the drop strength of the bottle.

(5) Enthalpy relaxation amount About a sample that was stored in a thermostat at 50 ° C. for 210 hours and subjected to an acceleration test, using a differential scanning calorimeter (TA Q2000 manufactured by TA Instruments), a temperature increase rate of 10 ° C./min. Measured with The amount of enthalpy relaxation was determined from the area of the endothermic peak at the time of glass transition. FIG. 1 shows an example of a DSC curve obtained by measuring a polyester resin composition with a differential scanning calorimeter. The area of the endothermic peak at the time of glass transition was determined as shown in FIG.

(6) Evaluation of chemical resistance A sample 3 cm long and 3 cm wide was cut out from the body of the molded transparent bottle and immersed in a 1% acetone-containing benzine solution at 40 ° C. and stored for 7 days. The haze value of the sample before and after immersion was measured, and the increase in haze value after immersion was less than 10, A was 10 or more and less than 20, and B was 20 or more.

Example 1

[Preparation of polyester (A) pellets]
(1) Melt polycondensation 100.0 parts by mass of terephthalic acid, 38.1 parts by mass of ethylene glycol and cyclohexane-1,4-dimethanol [CHDM, mixing ratio of cis isomer to trans isomer (cis isomer / trans isomer) is 30 / 70] A slurry composed of 13.0 parts by mass was prepared, and 0.012 parts by mass of germanium dioxide, 0.012 parts by mass of phosphorous acid and 0.043 parts by mass of cobalt acetate were added thereto. This slurry was heated to a temperature of 250 ° C. under pressure (absolute pressure 0.25 MPa) to carry out an esterification reaction to produce a low polymer. Subsequently, the obtained low polymer was transferred to a polycondensation tank, and pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-yl ester) was added as a polyvalent ester to 100 parts by mass of the low polymer. Hydroxyphenyl) propionate] 0.024 parts by mass and 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9 as an anti-coloring agent -0.048 parts by weight of diphosphaspiro [5,5] undecane was added. Under low pressure of 1 hPa, the low polymer was melt polycondensed at a temperature of 280 ° C. to produce a polyester having an intrinsic viscosity of 0.70 dl / g. The obtained polyester was extruded into a strand form from a nozzle and cooled with water, and then cut into a cylindrical shape (diameter: about 2.5 mm, length: about 2.5 mm) to obtain an intermediate polyester pellet.

(2) Crystallization of intermediate pellets The polyester intermediate pellets obtained as described above were put into a rolling vacuum solid phase polymerization apparatus, dried at 90 ° C for 24 hours at 1 hPa, and then at 160 ° C for 10 hours. Crystallization was performed.

(3) Solid Phase Polymerization Following the above crystallization, solid phase polymerization was carried out at 1 hPa and 200 ° C. for 38 hours to obtain polyester pellets (PES-Ar). It was 1.15 dl / g when the intrinsic viscosity of the obtained copolyester was measured by the above-mentioned method. Further, the copolymerized polyester constituting the monomer component ratio of ¹ H-NMR spectrum of (apparatus: manufactured by JEOL Ltd. "JNM-GX-500 Model", solvent: deuterated trifluoroacetic acid) was confirmed by Terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexanedimethanol unit: diethylene glycol = 100.0: 82.8: 14.2: 3.0 (molar ratio), containing polyvalent ester-derived units The amount was 0.025% by mass.

[Preparation of polyester (B) pellets]
As a raw material slurry, a polyhydric ester is used with respect to a slurry comprising 94.0 parts by mass of terephthalic acid, 6.0 parts by mass of isophthalic acid and 44.8 parts by mass of ethylene glycol, and 100 parts by mass of the low polymer. Except that 0.2 parts by mass was added, melt polycondensation, crystallization of intermediate pellets and solid phase polymerization were carried out in the same manner as PES-Ar to obtain polyester pellets (PES-B). The intrinsic viscosity of the polyester after melt polycondensation was 0.70 dl / g. The intrinsic viscosity of the polyester obtained by solid phase polymerization is 1.15 dl / g, and the ratio of the monomer components constituting the polyester is as follows: terephthalic acid unit: isophthalic acid unit: ethylene glycol unit: diethylene glycol = 94: It was 6: 97.5: 2.5 (molar ratio), and the content of the unit derived from the polyvalent ester in the polyester was 0.2% by mass.

[Production and evaluation of extrusion blow bottles]
PES-Ar and PETB obtained as described above were mixed at a ratio of PES-Ar: PETB = 80: 20 (mass ratio) to obtain mixed pellets. The mixed pellet was heat-dried at 140 ° C. for 6 hours, and extrusion blow molded by the above method to produce a transparent bottle. A drop test of the transparent bottle obtained, measurement of melting enthalpy, measurement of enthalpy relaxation amount, and evaluation of chemical resistance were performed by the above methods. The results are shown in Table 1.

Example 2
[Preparation of polyester (A) pellets]
(1) Melt polycondensation [polyester (A1)]
A slurry comprising 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 thereto. . 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 reached 95% to produce a low polymer. Subsequently, the obtained low polymer was transferred to a polycondensation tank having a capacity of 5 m ³ , and the low polymer was melt polycondensed at a temperature of 270 ° C. under a reduced pressure of 0.1 Torr. A 70 dl / g polyester was synthesized. The obtained polyester was extruded into a strand form from a nozzle, cooled with water, and then cut into a cylindrical shape (diameter: about 2.5 mm, length: about 2.5 mm) to obtain a polyester pellet (PES-A1). When the content of each structural unit of the obtained polyester was measured by the above method, the content of the terephthalic acid unit, the ethylene glycol unit, and the diethylene glycol unit was 50 mol%, 48 mol%, and 2 mol%, respectively. .

(2) Melt polycondensation [polyester (A2)]
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 (mixing ratio of cis isomer: trans isomer 30:70) was prepared. 0.015 parts by mass of germanium, 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 reached 95% to produce a low polymer. Subsequently, the obtained low polymer was transferred to a polycondensation tank having a capacity of 5 m ³ , and the low polymer was melt polycondensed at a temperature of 270 ° C. under a reduced pressure of 0.1 Torr. A polyester of 70 dl / g was produced. The obtained polyester was extruded into a strand form from a nozzle, cooled with water, and then cut into a cylindrical shape (diameter: about 2.5 mm, length: about 2.5 mm) to obtain a polyester pellet (PES-A2). When the content of each structural unit of the copolymer polyester thus obtained was measured by the above method, the content of the terephthalic acid unit, ethylene glycol unit, 1,4-cyclohexanedimethanol and diethylene glycol unit was 50 mol%. 18.8 mol%, 30 mol% and 1.2 mol%.

(3) Compound The above PES-A1 and PES-A2 are blended so that the mass ratio (PES-A1 / PES-A2) is 70/30, and further, 250 ppm of a polyvalent ester and 500 ppm of an anti-coloring agent are added. After preliminary mixing, the mixture was supplied to a twin screw extruder (“TEM-48SS” manufactured by Toshiba Machine Co., Ltd.). In addition, the same thing as what was used by preparation of PES-Ar was used for polyvalent ester and a coloring inhibitor. The extruder was set to a cylinder temperature of 330 ° C., a die temperature of 320 ° C., melt-kneaded at a vent vacuum pressure of 700 mmHg (absolute pressure of 60 mmHg) and an extrusion rate of 150 kg / hr to extrude a strand. When the molten resin was directly measured with a thermometer at the exit of the extruder die, the resin temperature was 332 ° C. The extruded strand was immediately cooled with water, and then cut into a cylindrical shape (diameter: about 2.5 mm, length: about 2.5 mm) to obtain an intermediate polyester pellet.

(4) Crystallization of intermediate pellets Crystallization of the intermediate pellets was performed under the same conditions as in the case of producing PES-Ar.

(5) Solid Phase Polymerization Solid phase polymerization was carried out under the same conditions as in the case of producing PES-Ar to obtain polyester pellets (PES-Ab). It was 1.15 dl / g when the intrinsic viscosity of the obtained copolyester was measured by the above-mentioned method. The ratio of the monomer component constituting this copolymerized polyester is as follows: terephthalic acid unit: ethylene glycol unit: 1,4-cyclohexanedimethanol unit: diethylene glycol = 100.0: 82.8: 14.2: 3.0 ( The content of the unit derived from the polyvalent ester was 0.025% by mass.

[Production and evaluation of extrusion blow bottles]
A bottle was produced and evaluated in the same manner as in Example 1 except that PES-Ab was used instead of PES-Ar. The results are shown in Table 1.

Comparative Examples 1-3
A bottle was produced and evaluated in the same manner as in Example 1 except that the composition of the pellet used for producing the bottle was changed as shown in Table 1. The results are shown in Table 1.

Comparative Example 4
[Preparation of copolyester pellets]
(1) Melt polycondensation 95.0 parts by mass of terephthalic acid, 5.0 parts by mass of isophthalic acid, 43.5 parts by mass of ethylene glycol and cyclohexane-1,4-dimethanol (cis / trans isomer mixing ratio 30:70) ) Polyester pellets (PES-C) were obtained by performing melt polycondensation, crystallization of intermediate pellets and solid phase polymerization in the same manner as PES-Ar except that a slurry consisting of 2.6 parts by mass was used. . The intrinsic viscosity of the polyester after melt polycondensation was 0.70 dl / g. The intrinsic viscosity of the polyester obtained by solid phase polymerization is 1.15 dl / g, and the ratio of the monomer components constituting the polyester is terephthalic acid unit: isophthalic acid unit: ethylene glycol unit: cyclohexanedimethanol unit. : Diethylene glycol unit = 95.1: 4.9: 94.4: 2.9: 2.7 (molar ratio), and the content of the unit derived from the polyvalent ester in the polyester is 0.025% by mass. there were.

[Production and evaluation of extrusion blow bottles]
Production and evaluation of the bottle were carried out in the same manner as in Example 1 except that only PETC was used as the pellet used for production of the bottle. The results are shown in Table 1.

  The bottles (Examples 1 and 2) obtained by molding mixed pellets comprising polyester pellets copolymerized with cyclohexanedimethanol and polyester pellets copolymerized with isophthalic acid have excellent chemical resistance. However, the impact resistance after a long period of time (after the acceleration test) was good. On the other hand, the bottle obtained by molding only polyester pellets copolymerized with isophthalic acid (Comparative Example 1) had insufficient impact resistance after a long period of time. In addition, bottles obtained by molding only polyester pellets copolymerized with cyclohexanedimethanol [Comparative Example 2 (block copolymerization), Comparative Example 3 (random copolymerization)] and isophthalic acid and cyclohexanedimethanol randomly The bottle (Comparative Example 4) obtained by molding the copolymerized polyester pellets had insufficient chemical resistance.

Claims (13)

A mixed pellet containing polyester (A) pellets and polyester (B) pellets,
The polyester (A) is mainly composed of a dicarboxylic acid unit mainly composed of terephthalic acid units, and an ethylene glycol unit and cyclohexanedimethanol unit, and the molar ratio thereof (ethylene glycol / cyclohexanedimethanol) is 75/25 to 98/2. The intrinsic viscosity of the polyester (A) is 0.85 to 1.5 dl / g,
The polyester (B) is mainly composed of a terephthalic acid unit and an isophthalic acid unit, and a dicarboxylic acid unit whose molar ratio (terephthalic acid / isophthalic acid) is 80/20 to 98/2, and an ethylene glycol unit. It consists mainly of diol units, the intrinsic viscosity of the polyester (B) is 0.8 to 1.5 dl / g, and the blending ratio (A / B) of the polyester (A) pellets to the polyester (B) pellets is 5 / 95-50 / 50 mixed pellets. The polyester (A) is obtained by condensation polymerization of terephthalic acid, ethylene glycol, cyclohexanedimethanol and a polyvalent ester,
The polyvalent ester is a carboxylic acid ester of a trivalent or higher polyol, and the carboxylic acid has a hindered phenol group,
The content of the unit derived from the polyvalent ester in the polyester (A) is 0.005 to 1.0% by mass,
The polyester (B) is obtained by condensation polymerization of terephthalic acid, isophthalic acid, ethylene glycol and the polyvalent ester, and the content of the unit derived from the polyvalent ester in the polyester (B) is 0.00. The mixed pellet according to claim 1, which is 005 to 1.0% by mass.   A resin composition obtained by melt-kneading the mixed pellets according to claim 1.   A molded product obtained by extrusion blow molding using the mixed pellets according to claim 1. After melt polymerization and kneading terephthalic acid, ethylene glycol and cyclohexanedimethanol, and obtaining an intermediate pellet by cutting, the intermediate pellet is solid-phase polymerized to obtain a polyester (A) pellet,
After melt polymerization and kneading terephthalic acid, isophthalic acid and ethylene glycol to obtain an intermediate pellet by cutting, the intermediate pellet is solid-phase polymerized to obtain a polyester (B) pellet,
The manufacturing method of the mixed pellet of Claim 1 which mixes the pellet of polyester (A) and the pellet of polyester (B) continuously. Pellets of polyester (A1) mainly composed of dicarboxylic acid units mainly composed of terephthalic acid units and diol units mainly composed of ethylene glycol units, dicarboxylic acid units mainly composed of terephthalic acid units, and ethylene glycol units and / or It is cut after melt-kneading polyester (A2) pellets mainly composed of diol units mainly composed of cyclohexanedimethanol units and having a molar ratio (ethylene glycol / cyclohexanedimethanol) of 0/100 to 80/20. After obtaining an intermediate pellet, polyester (A) pellets are obtained by solid-phase polymerization of the intermediate pellet,
After melt polymerization and kneading terephthalic acid, isophthalic acid and ethylene glycol to obtain an intermediate pellet by cutting, the intermediate pellet is solid-phase polymerized to obtain a polyester (B) pellet,
The manufacturing method of the mixed pellet of Claim 1 which mixes the pellet of polyester (A) and the pellet of polyester (B) continuously. After terephthalic acid, ethylene glycol, cyclohexanedimethanol and the polyvalent ester are melt-kneaded and subjected to polycondensation and then cut to obtain intermediate pellets, the intermediate pellets are solid-phase polymerized to form polyester (A) pellets Get
After terephthalic acid, isophthalic acid, ethylene glycol and the polyvalent ester are melt-kneaded and subjected to condensation polymerization and cut to obtain intermediate pellets, the intermediate pellets are solid-phase polymerized to form polyester (B) pellets. Get,
The manufacturing method of the mixed pellet of Claim 2 which mixes the pellet of polyester (A) and the pellet of polyester (B) continuously. A resin composition obtained by melt-kneading polyester (A) pellets and polyester (B) pellets,
The polyester (A) is mainly composed of a dicarboxylic acid unit mainly composed of terephthalic acid units, and an ethylene glycol unit and cyclohexanedimethanol unit, and the molar ratio thereof (ethylene glycol / cyclohexanedimethanol) is 75/25 to 98/2. The intrinsic viscosity of the polyester (A) is 0.85 to 1.5 dl / g,
The polyester (B) is mainly composed of a terephthalic acid unit and an isophthalic acid unit, and a dicarboxylic acid unit whose molar ratio (terephthalic acid / isophthalic acid) is 80/20 to 98/2, and an ethylene glycol unit. It consists mainly of diol units, the intrinsic viscosity of the polyester (B) is 0.80 to 1.5 dl / g, and the blending ratio (A / B) of the polyester (A) pellets to the polyester (B) pellets is 5 / 95-50 / 50 resin composition characterized by the above-mentioned. The polyester (A) is obtained by condensation polymerization of terephthalic acid, ethylene glycol, cyclohexanedimethanol and a polyvalent ester,
The polyvalent ester is a carboxylic acid ester of a trivalent or higher polyol, and the carboxylic acid has a hindered phenol group,
The content of the unit derived from the polyvalent ester in the polyester (A) is 0.005 to 1.0% by mass,
The polyester (B) is obtained by condensation polymerization of terephthalic acid, isophthalic acid, ethylene glycol and the polyvalent ester, and the content of the unit derived from the polyvalent ester in the polyester (B) is 0.00. It is 005-1.0 mass%, The resin composition of Claim 8.   A molded product obtained by extrusion blow molding using the resin composition according to claim 8. After melt polymerization and kneading terephthalic acid, ethylene glycol and cyclohexanedimethanol, and obtaining an intermediate pellet by cutting, the intermediate pellet is solid-phase polymerized to obtain a polyester (A) pellet,
After melt polymerization and kneading terephthalic acid, isophthalic acid and ethylene glycol to obtain an intermediate pellet by cutting, the intermediate pellet is solid-phase polymerized to obtain a polyester (B) pellet,
9. The method for producing a resin composition according to claim 8, wherein the polyester (A) pellets and the polyester (B) pellets are subsequently melt-kneaded. Pellets of polyester (A1) mainly composed of dicarboxylic acid units mainly composed of terephthalic acid units and diol units mainly composed of ethylene glycol units, dicarboxylic acid units mainly composed of terephthalic acid units, and ethylene glycol units and / or It is cut after melt-kneading polyester (A2) pellets mainly composed of diol units mainly composed of cyclohexanedimethanol units and having a molar ratio (ethylene glycol / cyclohexanedimethanol) of 0/100 to 80/20. After obtaining an intermediate pellet, polyester (A) pellets are obtained by solid-phase polymerization of the intermediate pellet,
After melt polymerization and kneading terephthalic acid, isophthalic acid and ethylene glycol to obtain an intermediate pellet by cutting, the intermediate pellet is solid-phase polymerized to obtain a polyester (B) pellet,
9. The method for producing a resin composition according to claim 8, wherein the polyester (A) pellets and the polyester (B) pellets are subsequently melt-kneaded. After terephthalic acid, ethylene glycol, cyclohexanedimethanol and the polyvalent ester are melt-kneaded and subjected to polycondensation and then cut to obtain intermediate pellets, the intermediate pellets are solid-phase polymerized to form polyester (A) pellets Get
After terephthalic acid, isophthalic acid, ethylene glycol and the polyvalent ester are melt-kneaded and subjected to condensation polymerization and cut to obtain intermediate pellets, the intermediate pellets are solid-phase polymerized to form polyester (B) pellets. Get,
The method for producing a resin composition according to claim 9, wherein the polyester (A) pellets and the polyester (B) pellets are subsequently melt-kneaded.