Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
  • B29C49/04—Extrusion blow-moulding
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
  • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
  • C08G63/16—Dicarboxylic acids and dihydroxy compounds
  • C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
  • C08G63/181—Acids containing aromatic rings
  • C08G63/183—Terephthalic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/78—Preparation processes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances

Definitions

• the present invention relates to a polyester suitable as a raw material for extrusion blow molding and a molded article made from the same.
• Polyesters such as polyethylene terephthalate have excellent properties such as transparency, mechanical properties, gas barrier properties, and flavor barrier properties. Furthermore, when polyester is made into a molded product, there is less concern about residual monomers or harmful additives, and it is also excellent in hygiene and safety. Therefore, taking advantage of these properties, polyester has recently been widely used as a substitute for vinyl chloride resin in hollow containers for filling juices, soft drinks, seasonings, oils, cosmetics, detergents, and the like.
• Patent Document 1 describes polyester pellets formed by condensation polymerization of terephthalic acid, ethylene glycol, cyclohexanedimethanol or bisphenol A ethylene oxide adduct, and polyvalent ester.
• Patent Document 2 describes a polyester containing 15 to 500 ppm of a component derived from 1,2-propanediol.
• Patent Document 3 describes that in a polyester whose main acid component is terephthalic acid and whose main glycol component is ethylene glycol, a compound represented by propylene glycol or the like is added in an amount of 0.5 to 30 mol% based on the total glycol component.
• a copolymerized polyester containing 2 to 30 ppm of an alkali metal compound is disclosed.
• the polyester described in Patent Document 1 contains a structural unit derived from cyclohexanedimethanol or bisphenol A ethylene oxide adduct.
• a structural unit derived from cyclohexanedimethanol or bisphenol A ethylene oxide adduct When containing a structural unit derived from cyclohexanedimethanol or bisphenol A ethylene oxide adduct, the physical properties of the polyester, particularly impact resistance, are improved.
• the number of structural units derived from the bisphenol A ethylene oxide adduct increases, it is necessary to use a large amount of bisphenol A, which is a raw material for synthesizing the bisphenol A ethylene oxide adduct.
• Patent Documents 2 and 3 only include 1,2-propanediol and cyclohexanedimethanol among the many examples of copolymerizable monomers, and do not provide any information regarding the impact resistance of polyester. Not listed.
• the present invention was made to solve the above problems, and provides a polyester that has good impact resistance even when the content of structural units derived from cyclohexanedimethanol or bisphenol A ethylene oxide adduct is small.
• the purpose is to
• polyester containing dicarboxylic acid units and specific diol units is suitable as a raw material for molding with little impact on the environment, particularly as a raw material for extrusion blow molding, and that it is possible to use the polyester. It was discovered that a molded article with good impact resistance could be obtained by using the method, and based on this knowledge, further studies were conducted to arrive at the present invention.
• a polyester containing a dicarboxylic acid unit and a diol unit wherein the dicarboxylic acid unit includes a structural unit derived from terephthalic acid, and the diol unit includes a first diol unit, a second diol unit, and a third diol unit.
• the first diol unit is a structural unit derived from ethylene glycol
• the second diol unit is a structural unit derived from 1,2-propanediol
• the third diol unit is a structural unit derived from bisphenol A.
• a polyester can be obtained that is suitable as a raw material for extrusion blow molding with little impact on the environment and that can produce molded products with good impact resistance.
• the polyester of the present invention is a polyester containing a dicarboxylic acid unit and a diol unit, wherein the dicarboxylic acid unit includes a structural unit derived from terephthalic acid, and the diol unit includes a first diol unit, a second diol unit, and a third diol unit, the first diol unit is a structural unit derived from ethylene glycol, the second diol unit is a structural unit derived from 1,2-propanediol, and the third diol unit is a structural unit derived from 1,2-propanediol.
• the polyester of the present invention has a structural unit derived from 1,2-propanediol as the second diol unit, and a bisphenol A ethylene oxide adduct as the third diol unit. and cyclohexanedimethanol, or both.
• the polyester contains the third diol unit, impact resistance becomes good.
• the melting point of the polyester can be lowered, and the molding temperature in direct blow molding can also be lowered.
• the polyester preferably contains a structural unit derived from cyclohexanedimethanol as the third diol unit.
• the polyester contains a structural unit derived from a bisphenol A ethylene oxide adduct as the third diol unit.
• the polyester contains the third diol unit
• the impact resistance becomes good, but from the viewpoint of impact on the environment and living organisms and recycling, the content of the third diol unit should not be too large. is desirable.
• the present inventor has discovered that by containing a certain amount of a structural unit derived from 1,2-propanediol as the second diol unit, the third diol unit is It has been found that impact resistance is good even when the content is small.
• the polyester of the present invention contains a certain amount or more of a component derived from 1,2-propanediol, which is the second diol unit, the amorphousness is further increased, so that it is easy to obtain a transparent and beautiful bottle.
• the content of structural units derived from terephthalic acid in the polyester of the present invention is preferably 80 mol% or more, more preferably 90 mol% or more, when the total of dicarboxylic acid units in the polyester is 100 mol%. More preferably, it is 95 mol% or more, and even more preferably, the dicarboxylic acid units in the polyester are substantially only structural units derived from terephthalic acid.
• the first diol unit is a structural unit derived from ethylene glycol.
• the content of structural units derived from ethylene glycol is not particularly limited, but is preferably 75 to 98 mol% when the total diol units contained in the polyester is 100 mol%.
• the content of the structural unit derived from ethylene glycol is more preferably 78 mol% or more, even more preferably 80 mol% or more, and preferably 83 mol% or more, 85 mol% or more, 88 mol% or more, or 90 mol% or more. There is also.
• the content of the structural unit derived from ethylene glycol is more preferably 97.5 mol% or less, and may be preferably 97 mol% or less, 96 mol% or less, or 95 mol% or less.
• the structural unit derived from ethylene glycol may be derived from biomass-derived ethylene glycol.
• the second diol unit is a structural unit derived from 1,2-propanediol, and when the total of diol units contained in the polyester is 100 mol%, the content X of the second diol unit is It is 0.001 to 0.5 mol%. If the content X of the second diol unit is more than the above upper limit, the impact resistance of the polyester container etc. will deteriorate. In particular, from the viewpoint of improving the impact resistance of containers etc., the content X of the second diol unit is preferably 0.4 mol% or less, more preferably 0.35 mol% or less, and 0.3 mol% or less. More preferred.
• the lower limit of the content of the second diol unit is preferably 0.01 mol% or more, more preferably 0.05 mol% or more, even more preferably 0.08 mol% or more, 0.10 mol% or more, 0.13 mol% or more, 0.137 mol% or more, 0.14 mol% or more, 0.15 mol% or more, 0.16 mol% or more, 0.162 mol% or more, 0.17 mol% or more, 0 .18 mol% or more or 0.189 mol% or more may be preferable in some cases. If it is less than the lower limit, it is not preferable because it is necessary to increase the content of the third diol unit in order to improve impact resistance.
• the component of the structural unit derived from 1,2-propanediol refers to the total amount of 1,2-propanediol detected when polyester is decomposed and analyzed, and it is the total amount of 1,2-propanediol that is copolymerized in the polymer chain. It represents the total amount of 1,2-propanediol consisting of a structure derived from 1,2-propanediol and 1,2-propanediol mixed between the polymer. That is, this 1,2-propanediol may be partially copolymerized in the polyester main chain, or may be contained as a single 1,2-propanediol without being copolymerized.
• the third diol unit is a structural unit derived from bisphenol A ethylene oxide adduct and/or cyclohexanedimethanol.
• the structural unit derived from the bisphenol A ethylene oxide adduct is one in which at least one ethylene oxide is added to each hydroxyl group of bisphenol A.
• the amount of ethylene oxide added is usually 2 to 4 mol % based on 1 mol of bisphenol A.
• cyclohexanedimethanol examples include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, and 1,4-cyclohexanedimethanol. Among them, 1,4- Cyclohexane dimethanol is preferred.
• the structural unit derived from cyclohexanedimethanol includes a cis-form and a trans-form, and the ratio thereof is not particularly limited, but in particular, the ratio of the cis-form/trans-form of cyclohexanedimethanol is in the range of 0/100 to 50/50.
• the total (Y+Z) is 2 to 25 mol%. If Y+Z is less than 2 mol%, the impact resistance and transparency of the resulting molded product will decrease.
• Y+Z is preferably 2.5 mol% or more, more preferably 3 mol% or more, even more preferably 4 mol% or more, and sometimes preferably 6 mol% or more or 8 mol% or more.
• Y+Z is preferably 20 mol% or less, 18 mol% or less, 15 mol% or less, 13 mol% or less, 10 mol% or less, or 8 mol% or less.
• the content of structural units derived from the bisphenol A ethylene oxide adduct when the total diol units contained in the polyester is 100 mol%.
• Y is 25 mol% or less, preferably 20 mol% or less, more preferably 15 mol% or less, and even more preferably 10 mol% or less. The reason is as mentioned above.
• the content Z of structural units derived from cyclohexanedimethanol is 25 mol% or less when the total diol units contained in the polyester is 100 mol%.
• the content is preferably 20 mol% or less, more preferably 15 mol% or less, and even more preferably 10 mol% or less. The reason is as mentioned above.
• the content Y (mol %) of the structural unit derived from the bisphenol A ethylene oxide adduct and the content Z (mol %) of the structural unit derived from cyclohexanedimethanol with respect to the content X (mol %) of the second diol unit. %) [(Y+Z)/X] is more preferably 10 or more, and even more preferably 12 or more.
• the ratio [(Y+Z)/X] is more preferably 60 or less, further preferably 40 or less, and particularly preferably 30 or less. When the ratio [(Y+Z)/X] is below the above upper limit, the hue tends to be excellent.
• the total content of the first diol unit, second diol unit, and third diol unit contained in the polyester of the present invention is usually 75 mol% or more when the total of diol units in the polyester is 100 mol%. is preferable, 90 mol% or more is more preferable, and even more preferably 95 mol% or more.
• the total content is usually 100 mol% or less.
• the polyester may contain 1 to 5 mol% of units derived from diethylene glycol, which is a by-product during the polycondensation reaction, based on the total 100 mol% of diol units in the polyester.
• the polyester of the present invention may have a unit derived from a polyvalent ester, if necessary.
• the polyvalent ester include pentaerythritol tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 1,3,5-tris[2-[3-(3,5- Examples include di-tert-butyl-4-hydroxyphenyl)propanoyloxy]ethyl]hexahydro-1,3,5-triazine-2,4,6-trione.
• the unit derived from the polyvalent ester is a carboxylic acid ester of a trivalent or higher polyol, and the carboxylic acid is derived from a polyvalent ester having a hindered phenol group, the unit derives from the polyvalent ester. It may be contained in the polyester of the present invention by melt-kneading and condensation polymerization with terephthalic acid, ethylene glycol, and cyclohexanedimethanol and/or bisphenol A ethylene oxide adduct. In the condensation polymerization, the polyol unit of the polyvalent ester and the carboxylic acid unit having a hindered phenol group are contained in the polyester by a transesterification reaction.
• the polyol unit is contained in the main chain, branch chain, or terminal of the polyester.
• a part of the polyol unit becomes a crosslinking point and acts as a crosslinking agent.
• a part of the carboxylic acid unit having a hindered phenol group is contained at the end of the polyester, and a part is contained in the polyester together with the polyol unit in a state of being bonded to the polyol unit.
• the polyvalent ester is preferably a carboxylic acid ester of a polyol having a valence of 3 or more and 5 or less.
• the content thereof is preferably 0.005 to 0.040% by mass.
• the content of the component derived from the polyester in the polyester is the total amount of the polyester-derived unit incorporated into the polyester chain and the component not incorporated into the polyester chain.
• the polyvalent ester added during melt-kneading is considered to be generally contained in the polyester chain. If the content of units derived from the polyvalent ester is less than 0.005% by mass, there is a risk that the drawdown resistance of the polyester will decrease, or that the polyester may be heated during polymerization or molding. Polyester tends to yellow, and the color tone of the resulting molded product may deteriorate.
• the content of the units derived from the polyvalent ester exceeds 0.040% by mass, crosslinking by the units derived from the polyvalent ester will progress too much, leading to the risk of the melt viscosity becoming too high and the resulting molded product being Impact resistance may decrease.
• the content of the units derived from the polyvalent ester is more preferably 0.030% by mass or less, and even more preferably 0.020% by mass or less.
• the polyester of the present invention contains a structural unit derived from the polyester
• the polyester contains a structural unit derived from terephthalic acid, a structural unit derived from ethylene glycol, a structural unit derived from cyclohexanedimethanol, and bisphenol A ethylene.
• the total content of the structural units derived from the oxide adduct and the structural units derived from the polyvalent ester is preferably 75 mol% or more, more preferably 90 mol% or more, based on the total of all structural units in the polyester. , more preferably 95 mol% or more.
• the total content is usually 100 mol% or less.
• the polyester of the present invention has a structural unit derived from terephthalic acid, a first diol unit, a second diol unit, and a structural unit derived from a bifunctional compound other than the third diol unit, if necessary. You can leave it there.
• the content of structural units derived from the bifunctional compound (if two or more types of units are included, the total) is 20 mol% or less, when the total of all structural units constituting the polyester is 100 mol%.
• the content is preferably 10 mol% or less, more preferably 5 mol% or less, and even more preferably 5 mol% or less.
• the bifunctional compound may be any dicarboxylic acid, diol, hydroxycarboxylic acid, or ester, and these may be aliphatic, alicyclic aliphatic, or aromatic.
• aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid and their ester-forming derivatives; cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dimer acid aliphatic dicarboxylic acids or their ester-forming derivatives such as; aliphatic diols such as neopentyl glycol, 1,4-butanediol, 1,5-pentamethylene diol, 1,6-hexamethylene diol, diethylene glycol, dimer diol, etc. ; ethylene oxide adduct of bisphenol S; and the like.
• the polyester of the present invention may have a structural unit derived from a polyfunctional compound as long as it does not impede the effects of the present invention.
• the structural unit derived from a polyfunctional compound is a polyfunctional compound derived from a polyfunctional compound having three or more carboxyl groups, hydroxyl groups, and/or their ester-forming groups.
• the content of the structural unit derived from the polyfunctional compound (if it has two or more types of units, the total) is 0.05% by mass or less, when the total of all structural units of the polyester is 100 mol%.
• the content is preferably 0.04% by mass or less, and more preferably 0.04% by mass or less.
• Polyfunctional compound units include 2-[3-(2-hydroxyethyl)-4-(2-hydroxyethoxy)phenyl]-2-[4-(2-hydroxyethoxy)phenyl]propane, trimellitic acid, Examples include polyfunctional compound units derived from pyromellitic acid, trimesic acid, trimethylolpropane, and glycerin. On the other hand, when containing a structural unit derived from the polyfunctional compound, the content is preferably 0.01% by mass or more.
• the polyester of the present invention may have polymerization ends and branched ends sealed with a monofunctional compound, if necessary.
• monofunctional compounds include benzoic acid, 2,4,6-trimethoxybenzoic acid, 2-naphthalenecarboxylic acid, stearic acid, stearyl alcohol, monocarboxylic acids other than carboxylic acids having hindered phenol groups, and monoalcohols. and ester-forming derivatives thereof.
• the monofunctional compound seals the molecular chain end groups and/or branched chain end groups of the polyester, thereby preventing excessive crosslinking and gel formation in the polyester.
• the content of the monofunctional compound unit (if it has two or more units, the total) is such that the total of all structural units of the polyester is 100 mol.
• the content of the monofunctional compound unit is such that the total of all structural units of the polyester is 100 mol.
• it is preferably 1 mol% or less, more preferably 0.5 mol% or less. If the content of other monofunctional compound units in the polyester exceeds 1 mol %, the polymerization rate during production of the polyester becomes slow and productivity tends to decrease.
• the polyester of the present invention may contain other additives as long as they do not impede the effects of the present invention, such as colorants such as dyes and pigments, stabilizers such as ultraviolet absorbers, and antistatic agents. , flame retardants, flame retardant aids, lubricants, plasticizers, inorganic fillers and the like.
• the content of these additives is preferably 10% by mass or less, more preferably 5% by mass or less.
• the intrinsic viscosity of the polyester of the present invention is not particularly limited, but from the viewpoint of extrusion blow molding, the lower limit of the intrinsic viscosity is preferably 0.8 dL/g or more, and more preferably 0.9 dL/g or more. On the other hand, from the viewpoint of molding, the upper limit of the limiting viscosity is preferably 1.5 dL/g or less, more preferably 1.4 dL/g or less.
• the polyester of the present invention can be produced by employing known production methods, including step (A) of esterifying or transesterifying carboxylic acids and diols, and melt polycondensation of the polyester oligomer obtained in step (A). step (B), and then step (C) of solid-phase polymerizing the composition obtained in step (B), where the diol is 1,2-propanediol, when the total of the diols is 100 mol%.
• the polyester of the present invention can be efficiently produced by employing a method for producing polyester containing 0.001 to 0.5 mol% of.
• the above-mentioned carboxylic acids may be used as they are, or carboxylic acid esters may be used.
• the alcohol moiety of the carboxylic acid ester is not particularly limited, and examples include monools such as methanol and ethanol; polyols such as ethylene glycol, cyclohexanedimethanol, and bisphenol A ethylene oxide adduct, which are constituent units of the polyester.
• the aforementioned diols may be used as they are, or monoesters or diesters of diols may be used.
• the carboxylic acid moiety of the monoester or diester is not particularly limited, and includes carboxylic acids such as formic acid, acetic acid, and propionic acid.
• a polyvalent ester When using a polyvalent ester, it may be reacted with the dicarboxylic acid and diol in the step (A), or it may be reacted with the polyester after obtaining the polyester oligomer.
• phosphoric acid compounds such as phosphorous acid or esters thereof can be used, and these can be used alone or in combination of two or more. good.
• the phosphoric acid compound include phosphorous acid, phosphorous ester, phosphoric acid, trimethyl phosphate, and triphenyl phosphate.
• the amount of the coloring inhibitor used is preferably within the range of 80 to 1000 ppm based on the total of the dicarboxylic acid component and the diester component.
• a cobalt compound such as cobalt acetate
• the amount used is within the range of 100 to 1000 ppm based on the total of the dicarboxylic acid component and diester component. It is more preferable.
• the polymerization catalyst used in the melt condensation polymerization is preferably a compound containing a germanium element, an antimony element, or a titanium element.
• Compounds containing antimony element include antimony trioxide, antimony chloride, antimony acetate, etc.
• Compounds containing germanium element include germanium dioxide, germanium tetrachloride, germanium tetraethoxide, etc. Examples of compounds used include tetraisopropyl titanate, tetrabutyl titanate, and the like.
• antimony trioxide and germanium dioxide are preferred from the viewpoint of polymerization catalyst activity, physical properties of the resulting polyester, and cost.
• the amount added is preferably in the range of 0.002 to 0.8% by mass based on the mass of the dicarboxylic acid component.
• the above-mentioned esterification reaction or transesterification reaction is carried out by charging the above-mentioned raw materials, a polymerization catalyst, and optionally additives such as a coloring inhibitor into a reactor, and then heating the mixture under an absolute pressure of about 0.5 MPa or less or under normal pressure. It is preferable to carry out the reaction at a temperature of 160 to 280° C. while distilling off the water or alcohol produced.
• the above-mentioned raw materials, polycondensation catalyst, and additives such as color inhibitors are added to the obtained polyester oligomer as necessary, and the pressure is reduced to 1 kPa or less. It is preferable to carry out the process at a temperature of 260 to 290° C. until a polyester of the desired viscosity is obtained.
• the reaction temperature of the melt polycondensation reaction is lower 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.
• the melt polycondensation reaction can be carried out using, for example, a tank-type batch-type polycondensation apparatus, a continuous-type polycondensation apparatus consisting of a biaxially rotating horizontal reactor, or the like.
• the intrinsic viscosity of the polyester obtained by melt polycondensation is preferably 0.4 dL/g or more. This not only improves handling properties but also improves productivity since the polyester obtained by melt polycondensation can be made to have a high molecular weight in a short time when it is further subjected to solid phase polymerization.
• the limiting viscosity is more preferably 0.55 dL/g or more, and still more preferably 0.65 dL/g or more.
• the intrinsic viscosity is preferably 0.9 dL/g or less, more preferably 0.85 dL/g or less, from the viewpoint of easily taking out the polyester from the reactor and suppressing coloring due to thermal deterioration. More preferably, it is 0.8 dL/g or less.
• the polyester obtained as described above is extruded into shapes such as strands and sheets, and after cooling, it is cut with a strand cutter or sheet cutter to obtain shapes such as cylinders, ellipsoids, discs, and dice. Produce intermediate pellets.
• the above-mentioned 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.
• the intermediate pellet may be subjected to solid phase polymerization. At this time, it is preferable to preliminarily crystallize a portion of the polyester by heating before solid phase polymerization. This can prevent pellets from sticking during solid phase polymerization.
• the crystallization temperature is preferably 100-180°C.
• the crystallization method it may be crystallized in a vacuum tumbler, or it may be crystallized by heating in an air circulation type heating device. When heating is performed in an air circulation type heating device, the internal temperature is preferably 100 to 160°C.
• 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 solid phase polymerization is preferably 170 to 250°C. If the solid phase polymerization temperature is less than 170° C., the solid phase polymerization time may become longer and productivity may decrease.
• the temperature of solid phase polymerization is more preferably 175°C or higher, and still more preferably 180°C or higher. On the other hand, if the solid phase polymerization temperature exceeds 250°C, there is a risk that the pellets will stick together.
• the temperature of solid phase polymerization is more preferably 240°C or lower, and still more preferably 230°C or lower.
• the solid phase polymerization time is usually about 5 to 70 hours. Further, the catalyst used in melt polymerization may be coexisting during solid phase polymerization.
• the solid phase polymerization is preferably carried out under reduced pressure or in an inert gas such as nitrogen gas. Furthermore, it is preferable to carry out the solid phase polymerization while moving the pellets by an appropriate method such as a tumbling method or a gas fluidized bed method so as to prevent the pellets from sticking together.
• the pressure is preferably 1 kPa or less.
• the intrinsic viscosity of polyester obtained by solid phase polymerization may vary depending on the type of melt molding method for copolymerized polyester, but when used for melt molding involving melt extrusion, especially extrusion blow molding, it is 0.8 to 0.8. It is preferably 1.5 dL/g, and is preferably 0.9 to 1.4 dL/g, especially from the viewpoint of the mechanical properties, appearance, and productivity of the extrusion blow-molded product obtained when manufacturing the molded product. More preferred.
• the half-crystallization time at the crystallization peak temperature of the polyester contained in the polyester obtained by solid phase polymerization may be 30 minutes or more.
• crystallization peak temperature refers to the heating of amorphous polyester from room temperature (20°C) to a temperature above the melting point (280°C) at 10°C/min using a differential calorimeter (DSC). This is the temperature of the exothermic peak associated with crystallization measured as follows.
• "half-crystallization time at crystallization peak temperature” means -50 °C after melting polyester by heating it to a temperature above the melting point (280 °C) using a differential calorimeter (DSC).
• isothermal crystallization is performed by holding at that crystallization peak temperature. After reaching the crystallization peak temperature, the amount of heat generated by isothermal crystallization is equal to the total heat generation. It means the time it takes for the amount to decrease to 1/2.
• the crystal melting enthalpy of the polyester of the present invention may be 20 J/g or more.
• Pellets obtained by solid phase polymerization contain polyester that has been crystallized at high temperatures for a long period of time, and therefore may have such a large enthalpy of crystal fusion.
• the polyester of the present invention has a high viscosity during melt molding, so it is suitable for extrusion blow molding.
• the temperature of the resin composition during extrusion molding is preferably within the range of (melting point of polyester + 10°C) to (melting point of polyester + 70°C), and (melting point of polyester + 10°C) to (melting point of polyester + 40°C). It is more preferable to set the temperature within the range of (°C). Drawdown can be suppressed by extruding at a temperature relatively close to the melting point.
• extrusion blow molding is particularly suitable for using the polyester of the present invention.
• the extrusion blow molding method is not particularly limited, and can be performed in the same manner as conventionally known extrusion blow molding methods.
• the polyester of the present invention is melt-extruded to form a cylindrical parison, and while the parison is in a softened state, it is sandwiched between blow molds, and a gas such as air is blown into the parison to shape the mold cavity. This can be done by expanding the tube into a predetermined hollow shape.
• the extruded parison has good drawdown properties, and blow molded products can be manufactured with good productivity.
• the molded product thus obtained has excellent transparency, good appearance and color tone, and high mechanical strength, especially impact resistance. Furthermore, it has excellent properties such as gas barrier properties, flavor barrier properties, moisture resistance, and chemical resistance, so it can be used for various purposes. Moreover, it can also be made into a molded product having a laminated structure with other thermoplastic resins. Molded articles obtained using the polyester have particularly excellent transparency. As described above, a molded article containing the polyester is a preferred embodiment of the present invention, a more preferred embodiment is a molded article formed by extrusion molding the polyester, and a molded article formed by extrusion blow molding the polyester. is a particularly preferred embodiment.
• Ratio of monomer components The ratio of monomer components constituting polyester was determined by 1H -NMR spectrum (equipment: "JNM-ECZ 400S” manufactured by JEOL Ltd., solvent: deuterated trifluoroacetic acid). confirmed. The amount of 1,2-propanediol was calculated from the integral ratio of the peak of terephthalic acid around 7.9 to 8.5 ppm and the peak of 1,2-propanediol around 5.3 to 5.7 ppm.
• Tg Glass transition temperature
• Tm glass transition temperature
• Tg glass transition temperature
• Bottle molding, bottle drop strength test Using an extrusion blow molding device (“MSE-40E/32M-A (T1) type” manufactured by Tahara Co., Ltd.), the maximum cylinder temperature was 280 to 290°C, and the die temperature was 240 to 250°C.
• the bottle As a drop test for the bottle, the bottle was filled with water that had been kept at a temperature of 23°C so that no air bubbles remained inside the bottle, was sealed with a cap, and then passed through a vertically installed cylinder with a diameter of 10 cm, and was dropped from a height of 125 cm onto horizontal concrete. They were dropped alternately onto a concrete surface tilted at a 45 degree angle. The bottle was repeatedly dropped up to 20 times, once on a horizontal surface and once on a 45-degree slope, until the bottle cracked or cracked and the water filled inside leaked out. A drop test was performed on five bottles for each composition, and the average value was taken as the bottle drop strength.
• Bottle drop strength and accelerated bottle drop strength were used as indicators of impact resistance, and the higher the number of times, the better the impact resistance.
• Example 1 100.00 parts by weight of terephthalic acid, 42.59 parts by weight of ethylene glycol, 9.49 parts by weight of bisphenol A ethylene oxide adduct, 2-[3-(2-hydroxyethyl)-4-(2-hydroxyethoxy)phenyl] A slurry consisting of 0.039 parts by weight of -2-[4-(2-hydroxyethoxy)phenyl]propane (hereinafter referred to as "HEPP") and 0.216 parts by weight of 1,2-propanediol was prepared, and 0.020 parts by weight of 1,2-propanediol was prepared. Parts by weight of germanium dioxide and 0.015 parts by weight of phosphorous acid were added.
• HEPP -2-[4-(2-hydroxyethoxy)phenyl]propane
• 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 above-mentioned low polymer was subjected to melt polycondensation at a temperature of 270° C. under a reduced pressure of 1 mmHg to produce a copolyester prepolymer having an intrinsic viscosity of 0.76 dL/g, which was passed through a nozzle in the form of a strand. It was extruded and cut into cylindrical chips (diameter 2.5 mm, length 3.5 mm).
• Example 2 A slurry consisting of 100.00 parts by weight of terephthalic acid, 43.49 parts by weight of ethylene glycol, 5.64 parts by weight of bisphenol A ethylene oxide adduct, 0.216 parts by weight of 1,2-propanediol and 0.089 parts by weight of HEPP was used. Polyester was produced and evaluated in the same manner as in Example 1, except that the polymerization and solid phase polymerization times were as shown in Table 1. The results are shown in Tables 1 and 2.
• Example 3 100.00 parts by weight of terephthalic acid, 42.59 parts by weight of ethylene glycol, 9.52 parts by weight of 1,4-cyclohexanedimethanol, 0.216 parts by weight of 1,2-propanediol, and pentaerythritol tetrakis
• 3-(3, Polyester was prepared in the same manner as in Example 1, except that a slurry containing 0.012 parts by weight of 5-di-tert-butyl-4-hydroxyphenyl)propionate was used and the solid-state polymerization time was as shown in Table 1. was manufactured and evaluated. The results are shown in Tables 1 and 2.
• Example 4 A slurry consisting of 100.00 parts by weight of terephthalic acid, 40.69 parts by weight of ethylene glycol, 11.38 parts by weight of bisphenol A ethylene oxide adduct, 0.133 parts by weight of 1,2-propanediol and 0.046 parts by weight of HEPP was used. Polyester was produced and evaluated in the same manner as in Example 1, except that the polymerization and solid phase polymerization times were as shown in Table 1. The results are shown in Tables 1 and 2.
• Example 5 A slurry consisting of 100.00 parts by weight of terephthalic acid, 40.57 parts by weight of ethylene glycol, 11.51 parts by weight of bisphenol A ethylene oxide adduct, 0.033 parts by weight of 1,2-propanediol and 0.044 parts by weight of HEPP was used. Polyester was produced and evaluated in the same manner as in Example 1, except that the polymerization and solid phase polymerization times were as shown in Table 1. The results are shown in Tables 1 and 2.
• a bottle obtained by molding a polyester (Examples 1 to 5) having a first diol unit, a second diol unit, and a third diol unit and satisfying the above formulas (1) and (2) is: Despite the low content of the third diol unit, the bottle drop strength and accelerated bottle drop strength were good. On the other hand, bottles obtained by molding polyesters that do not contain the second diol unit (Comparative Examples 1 to 3) were inferior in bottle drop strength and accelerated bottle drop strength.
• the present invention it is possible to obtain a polyester that is suitable as a raw material for extrusion blow molding with little impact on the environment and that can produce molded products with good impact resistance.

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