Polyester resin

Abstract

The purpose of the present invention is to provide, inter alia, a polyester resin that exhibits an excellent gelation suppression, moldability, surface smoothness, transparency, mechanical properties, heat resistance, stability of the thermal oxidation resistance, and chemical resistance.　The polyester resin characteristically contains, as constituent components, terephthalic acid for the dicarboxylic acid component and ethylene glycol, 1,4-butanediol, and a compound of prescribed structure for the alcohol component, wherein the terephthalic acid is 85-100 mol% of the dicarboxylic acid component, the 1,4-butanediol is 85-100 mol% with reference to the total amount of the ethylene glycol and 1,4-butanediol, and the compound of prescribed structure is 0.001-5 mass% in 100 mass% for the alcohol component.

Description

Technical Field

[0001] The present invention relates to a polyester resin that provides molded articles having excellent moldability, transparency, mechanical properties, heat resistance, heat oxidation stability, and chemical resistance. Specifically, the present invention relates to a polyester resin that, in addition to improving moldability in extrusion molding, profile extrusion molding, direct blow molding, inflation molding, injection blow molding, and calendar processing molding, which require high melt tension, also realizes improvements in transparency, heat resistance, mechanical properties, heat oxidation stability, and chemical resistance.

Background Art

[0002] In recent years, for example, due to environmental impact issues, there has been a tendency to replace vinyl chloride resins with other materials. Among several alternative materials, polyester resins are being considered as promising materials in terms of physical properties, environmental suitability, adhesion properties, price, etc.

[0003] Among them, crystalline polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN) are used in various melt-molded products such as heat-resistant parts by injection molding, films and sheets by extrusion molding, beverage bottles by blow molding, and fibers by melt spinning.

[0004] However, in order to improve the transparency and flexibility of molded articles using these crystalline polyester resins, various techniques such as control of cooling conditions during processing and stretching processing are required. In addition, for profile extrusion molding, direct blow molding, and inflation molding, which require high melt tension, the drawdown phenomenon becomes prominent, and the preform or molded article droops, resulting in large thickness unevenness and burrs in the molded article, leading to problems such as a decrease in the yield rate and continuous production stability.

[0005] On the other hand, in order to solve the problem of such a drawdown phenomenon, an invention is disclosed that improves the formability of direct blow molding, which requires high melt tension, by introducing a branched structure (branching agent) into the resin skeleton (for example, Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the technologies of Patent Documents 1 to 3, the reactivity between the branched structures (branching agents) is high, and even when mixed with a carboxylic acid compound and reacted with the components of the polyester resin, a gelled product is generated, the solubility with the components of the polyester resin decreases, and there is a problem that the obtained polyester resin molded product cannot provide good surface smoothness. In addition, in Patent Documents 1 to 3, although the drawdown phenomenon is improved, due to the too high melt tension, when the resin is discharged from the die during molding, the surface smoothness of the molded product is reduced due to the occurrence of melt fracture, and there is also a problem that the transparency of the molded product decreases. In addition, the molded product of the polyester resin is also required to have heat resistance and the like.

[0008] The present invention has been made against the background of such problems of the prior art, and the object of the present invention is to provide a polyester resin that provides a molded product excellent in gelation suppression, formability, surface smoothness, transparency, mechanical properties, heat resistance, heat - oxidation stability, and chemical resistance.

[0009] More specifically, the present invention aims to provide a polyester resin that offers excellent moldability in extrusion molding, morph extrusion molding, direct blow molding, inflation molding, injection blow molding, and calendering molding, which require high melt tension, and exhibits superior gelation suppression, surface smoothness, transparency, mechanical properties, heat resistance, heat oxidation stability, and chemical resistance. [Means for solving the problem]

[0010] As a result of diligent research, the inventors of the present invention have found that the above problems can be solved by the means described below, and have arrived at the present invention. That is, the present invention has the following configuration.

[0011] [1] A polyester resin characterized by containing terephthalic acid as a dicarboxylic acid component, ethylene glycol, 1,4-butanediol, and a compound represented by the following formula (I) as alcohol components, wherein terephthalic acid is present in an amount of 85 to 100 mol% of the dicarboxylic acid component, 1,4-butanediol is present in an amount of 85 to 100 mol% of the total amount of ethylene glycol and 1,4-butanediol, and the compound represented by the following formula (I) is present in an amount of 0.001 to 5% by mass of 100% by mass of the alcohol component. [ka] (In the formula, m and n are integers from 1 to 1000, respectively, and l is an integer from 0 to 1000, R 1 This represents an aromatic hydrocarbon group with 6 to 20 carbon atoms, R 2 , R 3 , R 4 Each of these represents either a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. 5 This represents a monool (CH2CH2CH2CH2OH) with 4 carbon atoms. [2] The polyester resin according to [1], wherein the weight-average molecular weight of the compound represented by formula (I) is 275 or more and 500,000 or less. [3] Melt tension was measured at a temperature of 270°C, a draw speed of 100 m / min, and a shear speed of 243 s. -1The polyester resin described in [1] or [2] with a value of 15 mN or more. [4] The melt viscosity is at a temperature of 270 °C and a shear rate of 30 s -1 at a temperature of 270 °C and a shear rate of 2000 s, and is 26000 dPa·s or more, -1 at a temperature of 270 °C and a shear rate of 2000 s, and is 6500 dPa·s or less, the polyester resin according to any one of [1] to [3].

Advantages of the Invention

[0012] According to the present invention, a molded product of a polyester resin excellent in gelation suppression, moldability, surface smoothness, transparency, mechanical properties, heat resistance, heat-oxidation stability, and chemical resistance can be obtained. In particular, the moldability is excellent in extrusion molding, profile extrusion molding, direct blow molding, inflation molding, injection blow molding, and calendar processing molding, which require a higher melt tension compared to the prior art.

Modes for Carrying Out the Invention

[0013] 1. Polyester Resin The polyester resin of the present invention contains terephthalic acid as a dicarboxylic acid component, ethylene glycol, 1,4-butanediol, and a compound represented by the following formula (I) as constituent components, and terephthalic acid is 85 to 10% by mol in the dicarboxylic acid component, 1,4-butanediol is 85 to 100 mol% with respect to the total amount of ethylene glycol and 1,4-butanediol, and the compound represented by the following formula (I) is 0.001 to 5% by mass in 100% by mass of the alcohol component.

[0014]

Chemical Formula

[0015] The polyester resin of the present invention is characterized in that it contains a polymer of a predetermined dicarboxylic acid component and an alcohol component, and the alcohol component has a predetermined content of a compound represented by formula (I). In the present invention, the compound represented by formula (I) is a branching agent for polyester resins and is used together with commonly used diol components. Furthermore, the compound represented by formula (I) has two or more functional groups (hydroxyl groups) per molecule that can react with the carboxyl group of the dicarboxylic acid component, and a branched structure can be partially introduced into the entire polyester resin.

[0016] As described above, the polyester resin of the present invention uses a compound represented by formula (I), which suppresses gelation, and during melt extrusion, the melt tension decreases as the temperature increases, and the melt viscosity decreases under high shear, resulting in no melt fracture during molding, and thus excellent moldability, surface smoothness, transparency, mechanical properties, heat resistance, heat oxidation stability, and chemical resistance.

[0017] The compounds represented by formula (I) are as follows: [ka]

[0018] (In the formula, m and n are integers from 1 to 1000, respectively, and l is an integer from 0 to 1000, R 1 This represents an aromatic hydrocarbon group with 6 to 20 carbon atoms, R 2 , R 3 , R 4 Each of these represents either a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. 5 This represents a monool (CH2CH2CH2CH2OH) with 4 carbon atoms.

[0019] R 1 This represents an aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0020] R 1 Aromatic hydrocarbon groups with 6 to 20 carbon atoms represented by include phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2-ethylphenyl group, 3-ethylphenyl group, 4-ethylphenyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 4-vinylphenyl group, o-isopropylphenyl group, m-isopropylphenyl group, p-isopropylphenyl group, o-tert-butylphenyl group, m-tert-butylphenyl group, p-tert-butylphenyl Examples include the 3,5-di(tert-butyl)phenyl group, 3,5-di(tert-butyl)-4-methylphenyl group, 4-butylphenyl group, 4-pentylphenyl group, 2,6-bis(1-methylethyl)phenyl group, 2,4,6-tris(1-methylethyl)phenyl group, 4-cyclohexylphenyl group, 2,4,6-trimethylphenyl group, 4-octylphenyl group, 4-(1,1,3,3-tetramethylbutyl)phenyl group, 1-naphthyl group, 2-naphthyl group, 5,6,7,8-tetrahydro-1-naphthyl group, 5,6,7,8-tetrahydro-2-naphthyl group, and fluorenyl group.

[0021] The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 15, and even more preferably 6 to 12.

[0022] In particular, the aromatic hydrocarbon group is preferably a phenyl group, an o-tolyl group, an m-tolyl group, or a p-tolyl group, and most preferably a phenyl group.

[0023] R 2 , R 3 , R 4 This represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0024] R 2 , R 3 , R 4The alkyl groups having 1 to 10 carbon atoms represented by this symbol include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; Isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, 2-ethylbutyl group, 3,3-dimethylbutyl group, 1,1,3,3-tetramethylbutyl group, 1-methylbutyl group, 1-ethylpropyl group, 3-methylbutyl group, neopentyl group, 1,1-dimethylpropyl group, 2-methylpentyl group, 3-ethylpentyl group, 1,3-dimethylbutyl group, 2-propylpentyl group, 1-ethyl-1,2-dimethylpropyl group, 1-methylpentyl group, 4-methylpentyl group, 4-methylpentyl group Branched alkyl groups such as hexyl group, 5-methylhexyl group, 2-ethylhexyl group, 1-methylhexyl group, 1-ethylpentyl group, 1-propylbutyl group, 3-ethylheptyl group, 2,2-dimethylheptyl group, 1-methylheptyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-methyloctyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-butylpentyl group, 1-methylnonyl group, 1-ethyloctyl group, 1-propylheptyl group, and 1-butylhexyl group; Cyclopropyl group, 1-methylcyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, 1-methylcyclohexyl group, 2-methylcyclohexyl group, 3-methylcyclohexyl group, 4-methylcyclohexyl group, 1,2-dimethylcyclohexyl group, 1,3-dimethylcyclohexyl group, 1,4-dimethylcyclohexyl group, 2,3-dimethylcyclohexyl group, 2,4-dimethylcyclohexyl group, 2,5-dimethylcyclohexyl group Examples of cycloalkyl groups include cyclohydroxyl groups such as 2,6-dimethylcyclohexyl, 3,4-dimethylcyclohexyl, 3,5-dimethylcyclohexyl, 2,2-dimethylcyclohexyl, 3,3-dimethylcyclohexyl, 4,4-dimethylcyclohexyl, cyclooctyl, 2,4,6-trimethylcyclohexyl, 2,2,6,6-tetramethylcyclohexyl, and 3,3,5,5-tetramethylcyclohexyl.

[0025] The number of carbon atoms in the alkyl group is preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4.

[0026] Among these, the alkyl group is particularly preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and most preferably a methyl group.

[0027] R 2 and R 3 It is preferably an alkyl group having 1 to 10 carbon atoms, R 4 It is preferable that it is a hydrogen atom. R 5 This is a 4-carbon monool, specifically a 4-hydroxybutyl group, "CH2CH2CH2CH2OH".

[0028] The aforementioned l, m, and n are the ratios of the copolymer components (L), (M), and (N) contained in one molecule, and the average number of each component contained in one molecule, expressed as an integer rounded to one decimal place (ratio). The ratios and average number of each component contained in one molecule are: 1 H-NMR analysis and 13 This was determined from 1C-NMR analysis. [ka]

[0029] m and n may be the same or different, and represent integers from 1 to 1000, preferably from 2 to 800, more preferably from 5 to 600, and even more preferably from 10 to 400. l is an integer between 0 and 1000, preferably between 1 and 700, more preferably between 2 and 400, and even more preferably between 5 and 100.

[0030] The compound represented by formula (I) may be a random copolymer in which copolymer components (L), (M), and (N) are randomly copolymerized, or a block copolymer in which at least one of the copolymer components (L), (M), and (N) acts as a block, but a random copolymer is preferred. The polyester resin of the present invention may be one or more polyester resins, as long as the above m, n, and l are satisfied.

[0031] The compound represented by formula (I) can be prepared in a 2-gallon free radical continuous polymerization reactor system, for example, by referring to the descriptions in Patent Documents 1-3, U.S. Patent Application No. 09 / 354350, and U.S. Patent Application No. 09 / 614402.

[0032] The content of the compound represented by formula (I) is 0.001 to 5% by mass, preferably 0.005 to 5% by mass, more preferably 0.01 to 4.5% by mass, even more preferably 4% by mass or less, and particularly preferably 3.5% by mass or less, based on 100% by mass of the alcohol component that is a constituent of the polyester resin. When the content of the compound represented by formula (I) is less than 0.001% by mass, drawdown occurs during molding, resulting in unstable molding or, even if molding is successful, the molded product tends to have uneven thickness. On the other hand, when the content of the compound represented by formula (I) exceeds 5% by mass, gelation occurs, melt fracture occurs during molding, resulting in poor surface smoothness and devitrified molded products. Furthermore, there is a tendency for the molded product to be of low quality due to the presence of gel.

[0033] The compound represented by formula (I) may have a predetermined weight-average molecular weight, which is preferably 275 to 500,000, more preferably 500 or more, even more preferably 700 or more, even more preferably 1,000 or more, more preferably 300,000 or less, even more preferably 100,000 or less, even more preferably 50,000 or less. If the weight-average molecular weight of the compound represented by formula (I) is less than 275, unreacted compounds may bleed out onto the surface of the molded product, potentially contaminating the surface. On the other hand, if the weight-average molecular weight of the compound represented by formula (I) exceeds 500,000, when a molded product made of polyester resin is bent, the compatibility between the compound and the polyester deteriorates, potentially causing voids and whitening. The weight-average molecular weight can be determined, for example, by GPC on a standard polystyrene basis. Specifically, the weight-average molecular weight can be determined by weighing 4 mg of a sample of the compound represented by formula (I), dissolving it in 4 ml of a mixed solvent of chloroform and isofluoroisopropanol (60 / 40 vol%), filtering it through a 0.2 μm membrane filter, subjecting the resulting sample solution to GPC, and converting it to standard polystyrene.

[0034] The dicarboxylic acid and alcohol components used in this invention are as follows:

[0035] Examples of dicarboxylic acid components include saturated aliphatic dicarboxylic acids or their ester-forming derivatives (for example, alkyl esters of these with 1 to 20 carbon atoms), such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, 1,3-cyclobutanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, dimer acid, etc., and unsaturated aliphatic dicarboxylic acids or their ester-forming derivatives (for example, these Examples include aromatic dicarboxylic acids or their ester-forming derivatives (for example, alkyl esters having 1 to 20 carbon atoms), orthophthalic acid, isophthalic acid, terephthalic acid, 5-(alkali metal) sulfoisophthalic acid, diphenic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-biphenylsulfondicarboxylic acid, 4,4'-biphenyletherdicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, pamoic acid, anthracenedicarboxylic acid, etc.).

[0036] Of these dicarboxylic acid components, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid are preferred, with terephthalic acid being particularly preferred in terms of the physical properties of the resulting polyester resin.

[0037] In addition to the dicarboxylic acids mentioned above, small amounts of trivalent to tetravalent carboxylic acids may also be used. Examples of carboxylic acids include ethane acid, tricarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3,4,3',4'-biphenyltetracarboxylic acid, and their ester-forming derivatives (for example, alkyl esters of these having 1 to 20 carbon atoms).

[0038] As for the alcohol component, it is preferable that it be a diol component other than the compound represented by formula (I). Of 100% by mass of the alcohol component, the diol component is preferably 99.999 to 95% by mass, more preferably 99.995 to 95% by mass, even more preferably 99.99 to 95.5% by mass, even more preferably 96% by mass or more, and particularly preferably 96.5% by mass or more. The diol component must contain 1,4-butanediol and preferably contains ethylene glycol. Other diols that may be used besides ethylene glycol and 1,4-butanediol include 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,5-pentanediol, neopentyl glycol, and 1,6-hexanediol. 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediethanol, 1,10-decamethylene glycol, 1,12-dodecanediol, isosorbide, polyethylene glycol, polytrimethylene glycol, polytetramethylene glycol, aliphatic glycols such as fluoroanol, hydroquinone, 4,4'-dihydroxybisphenol, 1, Examples of aromatic glycols include 4-bis(β-hydroxyethoxy)benzene, 1,4-bis(β-hydroxyethoxyphenyl)sulfone, bis(p-hydroxyphenyl) ether, bis(p-hydroxyphenyl)sulfone, bis(p-hydroxyphenyl)methane, 1,2-bis(p-hydroxyphenyl)ethane, bisphenol A, bisphenol F, bisphenol S, bisphenol C, 2,5-naphthalenediol, glycols obtained by adding ethylene oxide to these glycols, and compounds obtained by adding water to bisphenol A, F, S, and C.

[0039] In addition to the above-mentioned diol components, trivalent to tetravalent alcohols, hydroxycarboxylic acids, cyclic esters, etc., may also be used as diol components.

[0040] Examples of such alcohols include trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, and hexanetriol.

[0041] Examples of hydroxycarboxylic acids include lactic acid, citric acid, malic acid, tartaric acid, hydroxyacetic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, 4-hydroxycyclohexanecarboxylic acid, or ester-forming derivatives thereof (for example, alkyl esters having 1 to 20 carbon atoms).

[0042] Examples of cyclic esters include ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolides, and lactides.

[0043] The polyester resin of the present invention preferably contains terephthalic acid in an amount of 85 to 100 mol% of the dicarboxylic acid component, and a total of ethylene glycol and 1,4-butanediol in an amount of 85 to 100 mol% of the diol component. Terephthalic acid is more preferably present in an amount of 90-100 mol%, and even more preferably 95-100 mol%, of the dicarboxylic acid component, and the total amount of ethylene glycol and 1,4-butanediol is more preferably present in an amount of 90-100 mol%, and even more preferably 95-100 mol%, of the diol component. The 1,4-butanediol content is 85-100 mol% relative to the total amount of ethylene glycol and 1,4-butanediol. In other words, the ethylene glycol content is 0-15 mol% relative to the total amount of ethylene glycol and 1,4-butanediol. It can also be considered that 15-0 mol% of ethylene glycol and 85-100 mol% of 1,4-butanediol are contained in 100 mol% of the diol component. The content ratio of 1,4-butanediol relative to the total amount of ethylene glycol and 1,4-butanediol is preferably 87-100 mol%, more preferably 90-100 mol%, and even more preferably 93-100 mol%. When the 1,4-butanediol content is less than 85 mol%, moldability and chemical resistance tend to decrease. The polyester resin of the present invention is preferably a copolymerized polybutylene terephthalate resin.

[0044] The polyester resin of the present invention is a crystalline polyester resin having a branched structure, and can improve processability such as moldability through the "melt strength enhancement effect" of increasing molecular weight, as well as adjust the melt viscosity and melt tension, and can suppress the bending whitening resistance of molded products and the bleeding out of unreacted substances to the surface of molded products. If the content of terephthalic acid and 1,4-butanediol falls outside the above-mentioned range, the resulting polyester resin becomes amorphous, making it impossible to achieve high viscosity through solid-phase polymerization, and potentially preventing the acquisition of molded products with high mechanical properties.

[0045] The polyester resin of the present invention may have a predetermined intrinsic viscosity IV. The intrinsic viscosity IV is preferably 0.40 to 2.10 dl / g, more preferably 0.50 to 1.90 dl / g, and even more preferably 0.60 to 1.70 dl / g. The intrinsic viscosity can be measured at 30°C using an Ostwald viscometer after dissolving the polyester resin in a parachlorophenol / tetrachloroethane (3 / 1:by weight) mixed solvent.

[0046] The acid value (AV) of the polyester resin used in the present invention is preferably 100eq / 10 6 g(ton) or less, more preferably 60eq / 10 6 g or less, more preferably 50 eq / 10 6 It is less than or equal to g. On the other hand, the lower the limit, the better, preferably 0eq / 10 6 The closer to g, the better. Acid value of 100 eq / 10 6 When the g value exceeds a certain level, gel formation tends to occur, leading to a decrease in surface properties and haze. The acid value can be determined by dissolving a sample of polyester resin in an alcohol and / or ether solution and titrating it with an alcoholic sodium hydroxide solution or an alcoholic potassium hydroxide solution using phenolphthalein reagent as an indicator. The specific method for measuring the acid value is shown in the examples.

[0047] The polyester resin of the present invention may have a predetermined melting point, which is preferably 190 to 230°C, more preferably 200 to 230°C, even more preferably 210 to 230°C, and even more preferably 225°C or lower. The melting point can be determined using a differential scanning calorimetry (DSC) at a heating rate of 20°C / min up to 300°C, and the maximum peak temperature of the heat of fusion can be identified as the crystalline melting point.

[0048] The polyester resin of the present invention is preferably produced via a polymerization catalyst containing at least an aluminum compound and a phosphorus compound, and preferably has an aluminum content of 3 to 1000 ppm and a phosphorus content of 5 to 10000 ppm derived from the polymerization catalyst. As other polymerization catalysts, one or more selected from titanium compounds and germanium compounds may be used.

[0049] The aluminum compound is preferably at least one selected from aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, and aluminum hydroxide chloride, more preferably at least one selected from aluminum acetate and basic aluminum acetate, and even more preferably aluminum acetate. The amount of aluminum is preferably 3 to 1000 ppm, more preferably 5 to 800 ppm, and even more preferably 8 to 500 ppm, as aluminum atoms relative to the total mass of the polyester resin. If the amount of aluminum is too low, the polymerization activity may decrease, and if the amount of aluminum is too high, a large amount of aluminum-derived foreign matter may be generated.

[0050] The phosphorus compound is preferably at least one selected from phosphonic acid compounds and phosphinic acid compounds, and more preferably a phosphonic acid compound.

[0051] The phosphorus compound preferably has a phenol structure within the same molecule, more preferably is at least one selected from phosphonic acid compounds and phosphinic acid compounds having a phenol structure within the same molecule, and even more preferably is a phosphonic acid compound having a phenol structure within the same molecule.

[0052] Phosphorus compounds having a phenol structure within the same molecule include p-hydroxyphenylphosphonic acid, p-hydroxyphenylphosphonic acid dimethyl, p-hydroxyphenylphosphonic acid diethyl, p-hydroxyphenylphosphonic acid diphenyl, bis(p-hydroxyphenyl)phosphinic acid, bis(p-hydroxyphenyl)phosphinic acid methyl, bis(p-hydroxyphenyl)phosphinic acid phenyl, p-hydroxyphenylphenylphosphinic acid methyl, p-hydroxyphenylphenylphosphinic acid phenyl, p-hydroxyphenylphosphinic acid methyl, p-hydroxyphenylphosphinic acid phenyl, and 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid diethyl.

[0053] In particular, the phosphorus compound is preferably diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate. Such a phosphorus compound can be, for example, Irgamod® 295 (manufactured by BASF).

[0054] The phosphorus content is preferably 5 to 10,000 ppm, more preferably 8 to 8,000 ppm, and even more preferably 10 to 6,000 ppm, as phosphorus atoms, relative to the total mass of the polyester resin. If the phosphorus content is too low, polymerization activity will decrease and a large amount of aluminum-derived impurities may be generated. If the phosphorus content is too high, catalyst costs may increase.

[0055] Titanium compounds include tetrabutyl titanium, tetrabenzyl titanium, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, tetra-tert-butyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate, lithium titanate oxalate, potassium titanate oxalate, ammonium titanate oxalate, titanium oxide, composite oxides of titanium with silicon, zirconium, alkali metals, alkaline earth metals, etc., orthoesters or condensed orthoesters of titanium, and orthoesters of titanium. Examples of reaction products include those consisting of a ster or condensed orthoester and a hydroxycarboxylic acid, a reaction product consisting of a titanium orthoester or condensed orthoester, a hydroxycarboxylic acid and a phosphorus compound, and a reaction product consisting of a titanium orthoester or condensed orthoester, a polyhydric alcohol having at least two hydroxyl groups, a 2-hydroxycarboxylic acid and a base. Of these, composite oxides of titanium and silicon, composite oxides of titanium and magnesium, and reaction products consisting of a titanium orthoester or condensed orthoester, a hydroxycarboxylic acid and a phosphorus compound are preferred. The amount of titanium is preferably 1 to 300 ppm, more preferably 2 to 200 ppm, and even more preferably 3 to 100 ppm, as titanium atoms, relative to the total mass of the polyester resin. Examples of germanium compounds include germanium dioxide and germanium acetate. The amount of germanium is preferably 1 to 500 ppm, more preferably 2 to 400 ppm, and even more preferably 3 to 300 ppm, as titanium atoms, relative to the total mass of the polyester resin. The amount of the above atoms may be calculated, for example, by X-ray fluorescence analysis.

[0056] The polyester resin of the present invention preferably has a predetermined melt tension and melt viscosity when melted.

[0057] The polyester resin of the present invention has the property that its melt tension decreases as the temperature increases above 250°C. In this invention, from the viewpoint of exhibiting performance equivalent to or better than that of high-density polyethylene, the melt tension is set at a temperature of 270°C, a draw speed of 100 m / min, and a shear speed of 243 s. -1 The melt tension is preferably 15 mN or more, more preferably 17 mN or more, and even more preferably 19 mN or more, and the upper limit of the melt tension is, for example, 170 mN or less or 120 mN or less. The melt tension is measured, for example, using a capillary rheometer under predetermined conditions (capillary length 10 mm, capillary diameter 1 mm, temperature 270°C, shear rate 243 s). -1 This can be determined by using a maximum pickup speed of 200 m / min, a starting pickup speed of 10 m / min, or a constant pickup speed of 100 m / min with a pickup time of 90 seconds.

[0058] The polyester resin of the present invention has a shear rate of 2000 s at melting. -1 Furthermore, it has the property that the melt viscosity decreases as the temperature increases above 250°C. In this invention, from the viewpoint of suppressing the generation of melt fractures during melt extrusion, the melt viscosity is set at a temperature of 270°C and a shear rate of 30 s. -1 Therefore, the pressure is 26,000 dPa·s or higher, the temperature is 270°C, and the shear rate is 2000 s. -1 Preferably, the pressure is 6500 dPa·s or less. The polyester resin of the present invention exhibits thixotropy at high temperatures during melting, which suppresses the occurrence of melt fracture and provides good moldability.

[0059] The melt viscosity was determined at a temperature of 270°C and a shear rate of 30 s. -1 The viscosity is preferably 26,000 dPa·s or higher, more preferably 28,000 dPa·s or higher, and even more preferably 30,000 dPa·s or higher. The upper limit of the melt viscosity is, for example, 50,000 dPa·s or less, or 45,000 dPa·s or less.

[0060] The melt viscosity can be measured, for example, according to JIS K7199. The melt viscosity was calculated at a temperature of 270°C and a shear rate of 2000 s. -1The viscosity is preferably 6500 dPa·s or less, more preferably 6300 dPa·s or less, and even more preferably 6200 dPa·s or less, and the lower limit of the melt viscosity is, for example, 5500 dPa·s or more.

[0061] The melt viscosity is measured using a capillary rheometer under predetermined conditions (capillary length 10 mm, capillary diameter 1 mm, temperature 270°C, shear rate 30 s). -1 or 2000s -1 It can be obtained using ).

[0062] The polyester resin of the present invention may have predetermined heat-resistant oxidative decomposition parameters (TOD) and predetermined heat-resistant decomposition parameters (TD) from the viewpoint of heat resistance. The heat-resistant oxidative decomposition parameter (TOD) of the polyester resin is preferably 0.390 or less. TOD can be calculated by the method described in the section of the Examples below. TOD is more preferably 0.385 or less, even more preferably 0.380 or less, particularly preferably 0.375 or less, and most preferably 0.370 or less. The lower limit of TOD is, for example, 0.010 or more or 0.020 or more. If TOD is greater than 0.390, the moldability during drawdown tends to decrease. Furthermore, the thermal decomposition parameter (TD) of the polyester resin is preferably 0.55 or less. TD can be calculated by the method described in the following examples. A TD of 0.54 or less is more preferable, 0.53 or less is even more preferable, 0.52 or less is particularly preferable, and 0.50 or less is most preferable. The lower limit of TD is, for example, 0.18 or more or 0.20 or more. If the TD is greater than 0.50, the moldability during drawdown tends to decrease.

[0063] The polyester resin of the present invention may contain additives such as organic, inorganic, and organometallic toners, as well as fluorescent whitening agents. By including one or more of these additives, discoloration such as yellowing of the polyester resin can be suppressed to an even better level. Other arbitrary polymers, antistatic agents, defoaming agents, dyeability improvers, dyes, pigments, matting agents, fluorescent whitening agents, stabilizers, antioxidants, and other additives may also be included. As antioxidants, aromatic amine-based and phenol-based antioxidants can be used, and as stabilizers, phosphorus-based (such as phosphoric acid and phosphate esters), sulfur-based, and amine-based stabilizers can be used.

[0064] Furthermore, the polyester resin can be directly introduced into the molding process in a molten state after the melt polycondensation process is completed as described above, or in a chip state after further processing such as solid-phase polymerization, to form a molded article. Alternatively, a predetermined amount of additives, such as crystallization property improvers, aldehyde reducers, color improvers, stabilizers, etc., can be added to any reactor or transport piping in the manufacturing process of the melt polycondensation polymer, and after melt polycondensation to achieve the desired properties, it can be directly introduced into the molding process either as is, or after further processing such as solid-phase polymerization, to form a molded article.

[0065] A polyester resin molded article made from the polyester resin of the present invention may have a predetermined center surface mean (SRa) of three-dimensional roughness. The SRa of the polyester resin molded article is preferably less than 0.15 μm, more preferably 0.14 μm or less, even more preferably 0.13 μm or less, even more preferably 0.12 μm or less, and preferably 0.01 μm or more or 0.02 μm or more. The center surface average (SRa) of the three-dimensional roughness can be determined, for example, using a surface roughness measuring instrument (micro-shape measuring instrument, SurfCorder ET4000A manufactured by Kosaka Laboratory).

[0066] 2. Method for producing polyester resin The polyester resin of the present invention can be manufactured by conventionally known methods. For example, when manufacturing PBT, it can be produced by a direct esterification method in which terephthalic acid is directly reacted with 1,4-butanediol and optionally other copolymer components, water is distilled off to esterify, and then polycondensation is carried out under reduced pressure; or by a transesterification method in which dimethyl terephthalate is reacted with 1,4-butanediol and optionally other copolymer components, methyl alcohol is distilled off to transesterify, and then polycondensation is carried out under reduced pressure. Furthermore, solid-phase polymerization may be carried out as needed to increase the intrinsic viscosity. To promote crystallization before solid-phase polymerization, the molten polymerized polyester may be subjected to heat crystallization after absorbing moisture, or water vapor may be directly blown onto the polyester chips to induce heat crystallization. Regarding the method of adding the compound represented by formula (I), it is preferable to add it during polymerization. The compound represented by formula (I) may be added in a dispersed state at the time of addition.

[0067] The polycondensation reaction may be carried out in a batch reactor or a continuous reactor. In either of these methods, the esterification or transesterification reaction may be carried out in one step or in multiple steps. The polycondensation reaction may be carried out in one step or in multiple steps. The solid-phase polymerization reaction can be carried out in a batch reactor or a continuous reactor, similar to the polycondensation reaction. Polycondensation and solid-phase polymerization may be carried out continuously or in stages. Below, we will describe an example of a preferred continuous manufacturing method using PBT as the polyester resin.

[0068] The esterification reaction is carried out using a multi-stage apparatus consisting of 1 to 3 esterification reactors connected in series, under reflux conditions of 1,4-butanediol, while removing the water or alcohol produced by the reaction from the system using a rectification column. The temperature of the first stage esterification reaction is preferably 240 to 270°C, more preferably 245 to 265°C, and the pressure is preferably 0.2 to 3 kg / cm². 2 G, more preferably 0.5~2 kg / cm³ 2The final esterification reaction temperature is typically 250-290°C, preferably 255-275°C, and the pressure is typically 0-1.5 kg / cm². 2 G, preferably 0-1.3 kg / cm³ 2 G. When the process is carried out in three or more steps, the reaction conditions for the intermediate esterification reaction are between the reaction conditions for the first step and the reaction conditions for the final step. It is preferable that the increase in the reaction rate of these esterification reactions is distributed smoothly at each step. Ultimately, it is desirable that the esterification reaction rate reaches preferably 90% or more, more preferably 93% or more. These esterification reactions yield a lower-order condensate with a molecular weight of about 500 to 5000.

[0069] The above esterification reaction, when using terephthalic acid as a starting material, can be carried out without a catalyst due to the catalytic action of terephthalic acid as an acid, but it may also be carried out in the presence of a polycondensation catalyst.

[0070] Furthermore, it is preferable to add small amounts of tertiary amines such as triethylamine, tri-n-butylamine, and benzyldimethylamine, quaternary ammonium hydroxides such as tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide, and trimethylbenzylammonium hydroxide, and basic compounds such as lithium carbonate, sodium carbonate, potassium carbonate, and sodium acetate, and then perform polycondensation, as this allows the proportion of dioxybutylene terephthalate component units in the main chain of polybutylene terephthalate to be maintained at a relatively low level (5 mol% or less relative to the total diol components).

[0071] Next, when producing a low polymer by transesterification, a solution containing preferably 1.1 to 3.0 moles, more preferably 1.2 to 2.5 moles, of 1,4-butanediol per mole of dimethyl terephthalate is prepared and continuously supplied to the transesterification reaction step.

[0072] The transesterification reaction is carried out using an apparatus consisting of one or two transesterification reactors connected in series, under conditions of reflux of 1,4-butanediol, while removing the methanol produced by the reaction from the system using a rectification column. The temperature of the first stage of the transesterification reaction is preferably 180 to 250°C, more preferably 200 to 240°C. The temperature of the final stage of the transesterification reaction is usually 220 to 260°C, preferably 230 to 265°C, and fatty acid salts and carbonates of Zn, Cd, Mg, Mn, Co, Ca, Ba, etc., or oxides of Pb, Zn, Sb, Ge, etc. may be used as the transesterification catalyst. These transesterification reactions yield lower-order condensates with a molecular weight of approximately 200 to 500. Among these transesterification catalysts, Zn compounds are also effective catalysts for esterification and polycondensation reactions and can be used in those reactions as well.

[0073] The obtained lower-order condensate is then supplied to a multi-stage liquid-phase condensation polymerization process. The polycondensation reaction conditions are as follows: for the first stage of polycondensation, the reaction temperature is preferably 240-280°C, more preferably 240-270°C, and the pressure is preferably 500-20 Torr, more preferably 200-30 Torr; for the final stage of polycondensation, the reaction temperature is preferably 265-280°C, more preferably 265-275°C, and the pressure is preferably 10-0.1 Torr, more preferably 5-0.5 Torr. If the process is carried out in three or more stages, the reaction conditions for the intermediate stage of polycondensation are between the conditions for the first stage and the final stage. It is preferable that the degree of increase in intrinsic viscosity achieved in each of these polycondensation reaction steps is smooth.

[0074] The polycondensed polyester resin obtained in this manner is then subjected to solid-phase polymerization. The polyester resin is subjected to solid-phase polymerization by a conventionally known method. First, the polyester resin to be subjected to solid-phase polymerization is precrystallized by heating at a temperature of, for example, 100 to 190°C for 1 to 5 hours under an inert gas atmosphere, under reduced pressure, or under a water vapor or water vapor-containing inert gas atmosphere. Then, solid-phase polymerization is carried out at a temperature of 180 to 220°C for 1 to 100 hours under an inert gas atmosphere or under reduced pressure.

[0075] The catalyst used in this invention exhibits catalytic activity not only in polycondensation reactions but also in esterification and transesterification reactions. For example, the catalyst can be used in the transesterification reaction between alkyl esters of dicarboxylic acids such as dimethyl terephthalate and glycols such as 1,4-butanediol. Furthermore, the catalyst used in this invention exhibits catalytic activity not only in melt polymerization but also in solid-phase polymerization and solution polymerization, making it possible to produce polyester resins by any of these methods.

[0076] The polymerization catalyst used in this invention can be added to the reaction system at any stage of the polymerization reaction. For example, it can be added before the start of the esterification reaction or transesterification reaction, at any stage during the reaction, immediately before the start of the polycondensation reaction, or at any stage during the polycondensation reaction. In particular, it is preferable to add aluminum or an aluminum compound immediately before the start of the polycondensation reaction.

[0077] The method of adding polymerization catalysts other than phosphorus compounds used in this invention is not particularly limited and may be in powder or neat form, or in slurry or solution form of a solvent such as ethylene glycol. Furthermore, aluminum or an aluminum compound or phosphorus compound may be added as a pre-mixed mixture with other components, or these may be added separately. Also, aluminum or an aluminum compound or phosphorus compound and other components may be added to the polymerization system at the same time, or each component may be added at different times. Furthermore, the entire amount of catalyst may be added at once or in multiple installments.

[0078] The polyester resin of the present invention is preferably subjected to blow molding (preferably direct blow molding) after polycondensation and solid-phase polymerization. In blow molding of heat-resistant bottles, a bottomed precursor called a preform is generally prepared, and this preform may be blow-stretched in a mold and then heat-set. Methods such as compression molding and injection molding are used to manufacture the preform. Taking injection molding as an example, the preform can be obtained by heating and melting it to 250 to 350°C and injecting it into the mold of the preform. Typically, the preform has a thick-walled test tube shape with a gate at the bottom and a screw for a cap at the opening.

[0079] In heat-resistant bottles, the mouthpiece portion of the resulting preform may be crystallized. Crystallization prevents deformation of the mouthpiece portion even when filling with high-temperature contents. Crystallization of the mouthpiece portion is preferably carried out by heating to 130-200°C, more preferably 140-190°C. Heating methods include infrared heaters, hot air, induction heating, and immersion in an oil bath, with infrared heaters being preferred from the standpoint of productivity. Note that heating and crystallization of the mouthpiece portion may also be performed after blow molding.

[0080] A bottle is obtained by heating a preform, stretching it in the length direction (vertical direction) and blow-molding it in the circumferential direction. In the length direction, it is usually stretched with a rod-shaped stretching rod, and in the circumferential direction, a pressurized gas such as air or nitrogen is used. The pressurized gas is preferably 1 to 10 MPa. It is preferable to blow in the pressurized gas while inserting the stretching rod to stretch it simultaneously in the length direction and circumferential direction, but it may also be stretched in the length direction first and then in the circumferential direction. For heating, infrared heaters, hot air, induction heating, etc. are used. The heating temperature is usually 80 to 130°C, preferably 90 to 120°C.

[0081] The lower limit of the stretching ratio in the length direction of the bottle is preferably 1.5 times, more preferably 2 times. If it is less than the above, uneven stretching may occur. The upper limit of the stretching ratio in the length direction of the bottle is preferably 6 times, more preferably 5 times, and even more preferably 4 times. If it exceeds the above, tearing and other problems are more likely to occur.

[0082] The lower limit of the stretching ratio in the circumferential direction of the bottle is preferably 2 times, more preferably 2.5 times. If it is less than the above, uneven stretching may occur. The upper limit of the stretching ratio in the circumferential direction of the bottle is preferably 6 times, more preferably 5 times, and even more preferably 4 times. If it exceeds the above, tearing and other problems are more likely to occur.

[0083] When heat setting is performed in the same mold immediately after blow molding, the lower limit of the blow molding mold temperature is preferably 80°C, more preferably 120°C, even more preferably 130°C, and most preferably 140°C. If the temperature is lower than the above, sufficient crystallization may not be promoted during the subsequent heat setting, resulting in insufficient heat resistance, or a longer heat setting time may be required, leading to a decrease in productivity.

[0084] The upper limit of the mold temperature is preferably 350°C, more preferably 340°C, even more preferably 330°C, and particularly preferably 320°C, and the lower limit of the mold temperature is preferably 280°C, more preferably 290°C, and even more preferably 300°C. The polyester resin of the present invention has the property that its melt tension decreases as the temperature during melting increases. Therefore, when the mold temperature is increased, the melt tension decreases when the mold and the polyester resin come into contact, reducing the occurrence of melt fractures. On the other hand, after being discharged from the mold, the melt tension increases, reducing the occurrence of drawdown.

[0085] The blow-molded bottle is then heat-set in the mold. The lower limit of the heat-set time is preferably 0.5 seconds, more preferably 1 second, and even more preferably 1.5 seconds. If it is shorter than the above, sufficient crystallization may not occur, resulting in insufficient heat resistance. The upper limit of the heat-set time is preferably 15 seconds, more preferably 10 seconds, and even more preferably 5 seconds. Long heat-set times not only reduce productivity, but in the case of rotary blow molding machines, it is necessary to have many molds, and if the equipment becomes large, it may be less economical. After heat-setting in the mold, additional heat-setting may be performed by heating with infrared, hot air, induction heating, etc.

[0086] Alternatively, blow molding can be performed in a mold at 5-50°C, followed by heat setting in a heated mold. In this case, the temperature of the heat setting mold is the same as the mold temperature in the above-mentioned case.

[0087] A blow molding apparatus may have a single mold, but for mass production, it is preferable to have multiple molds that sequentially move through locations where the heated preform is set, stretched, heat-set, and the bottle is discharged. Although the cold parison method, in which the cooled preform is reheated, is described above, the hot parison method, in which blow molding is performed without completely cooling the preform, is also possible.

[0088] The capacity of the molded bottle is preferably 200 mL to 6 L, and more preferably 300 mL to 2 L. The shape of the bottle body can be any shape, such as circular, square (including shapes with cut corners), or hexagonal.

[0089] The polyester resin of the present invention is subjected to blow molding (preferably direct blow molding) and is suitably used for containers (e.g., bottles) for cosmetics, detergents, beverages, etc. [Examples]

[0090] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0091] Measurement of the intrinsic viscosity IV of polyester resin The polyester resin was dissolved in a mixed solvent of parachlorophenol / tetrachloroethane (3 / 1:by weight ratio), and the viscometer was measured at 30°C using an Ostwald viscometer.

[0092] Measurement of the composition of polyester resin The composition of the polyester resin was determined using a RUKER AVANCE500 Fourier transform nuclear magnetic resonance spectrometer in deuterated chloroform solvent. 1 The result was determined by performing 1H-NMR analysis and analyzing the integral ratio.

[0093] Measurement of the melting point of polyester resin 5 mg of polyester resin was placed in an aluminum sample pan and sealed. The temperature was measured up to 300°C at a heating rate of 20°C / min using a differential scanning calorimetry analyzer (DSC) DSC-Q100 manufactured by T.A. Instruments Japan Co., Ltd., and the maximum peak temperature of the heat of fusion was determined as the crystalline melting point.

[0094] Gel evaluation (1) Molding of hollow molded bodies Polyester resin was dried in a dryer using dehumidified air, and a preform was molded at a resin temperature of 290°C using a Meiki Seisakusho M-150C-DM injection molding machine. The spout portion of this preform was heated and crystallized using a homemade spout crystallization device to create a pre-molded body. Next, this pre-molded body was biaxially stretched and blown using a CORPOPLAST LB-01E molding machine, and then heat-set for approximately 5 seconds in a mold set to approximately 150°C to form a 1500cc container (hollow molded body). The stretching temperature was controlled to 100°C. (2) Appearance of the hollow molded body (checking for gel foreign matter) The aforementioned 100 hollow molded bodies were visually inspected and evaluated as follows. ○: Transparent and no issues with appearance. △~〇: One bottle containing gel foreign matter can be visually identified per 100 hollow molded bodies. △: Two bottles containing gel foreign matter can be visually identified per 100 hollow molded bodies. ×: Three or more bottles containing gel foreign matter can be visually identified per 100 hollow molded bodies.

[0095] Measurement of melt tension The melt tension of the polyester resin was measured using the following equipment and conditions during molding. Temperature: 270℃ Capillary rheometer (Toyo Seiki Seisakusho) Capillary length: 10mm Capillary diameter: 1mm Shear rate: 243s -1 Maximum pickup speed: 200m / min Pickup start speed: 10m / min Alternatively, the pickup speed is 100 m / min (constant). Pickup time: 90 seconds

[0096] Measurement of melt viscosity The melt tension of the polyester resin was measured using the following equipment and conditions during molding. Capillary rheometer (Toyo Seiki Seisakusho) Capillary length: 10mm Capillary diameter: 1mm Temperature: 270℃ Shear rate: 30s -1 or 2000s -1

[0097] Measurement of acid value (concentration of terminal carboxyl groups (unit: eq / ton, expressed as acid value)) 0.5 g of polyester resin was dissolved in 25 ml of benzyl alcohol and titrated using a benzyl alcohol solution of 0.01 mol / l sodium hydroxide. The indicator used was a solution of 0.10 g of phenolphthalein dissolved in a mixture of 50 ml of ethanol and 50 ml of water.

[0098] Measurement of the amounts of aluminum, phosphorus, germanium, titanium, and zinc atoms in polyester resin. Sample pieces were prepared by heating and melting polyester resin to its melting point +20°C inside a stainless steel circular ring with a thickness of 5 mm and an inner diameter of 50 mm. Elemental amounts were determined by X-ray fluorescence analysis and expressed in ppm. A calibration curve, derived from samples with known elemental amounts, was used to determine the amounts.

[0099] Deformed extrusion molding (evaluation of formability (drawdown), mechanical properties, surface smoothness, and transparency) A polyester resin was prepared by setting the cylinder temperature to 270°C, attaching a die lip to a single-screw extruder (L / D=30, full-flight screw, screw diameter 50mm), then attaching a sizing die to the front of a cooling water tank to determine the final dimensions of the extruded product. The product was then molded using an extrusion molding facility equipped with a take-up machine, passing through the water tank. The drawdown during molding, the mechanical properties of the molded product, surface smoothness, and transparency were evaluated according to the following criteria. The results are shown in Table 2.

[0100] Evaluation of moldability (drawdown) The drawdown was evaluated according to the following criteria. ◎: No sagging of the polyester resin occurs during molding, and the shape is maintained. ○: A slight drip of polyester resin occurs during molding. △: Polyester resin drips during molding, making stable mass production impossible. ×: Due to the dripping of polyester resin during molding, the resin cannot be passed from the die lip to the sizing mold.

[0101] Evaluation of the mechanical properties (strength) of molded products Polyester resin molded products were bent 180° and evaluated according to the following criteria. ○: No cracks observed with a 50x magnifying glass. △: No visible cracks, but cracks are present upon observation with a 50x magnifying glass. ×: Cracks visible to the naked eye.

[0102] Evaluation of surface smoothness The surface roughness of the outer surface of polyester resin molded products was measured using a Kosaka Laboratory SurfCorder Et4000A, and compared according to the following criteria based on the center-plane average (SRa) of the three-dimensional roughness. ◎: SRa is less than 0.10 μm ○: SRa is 0.10 μm or more and less than 0.12 μm △~〇: SRa is 0.12 μm or more and less than 0.14 μm △: SRa is 0.14 μm or more and less than 0.15 μm ×: SRa is 0.15 μm or larger

[0103] Transparency Assessment A 7mm thick molded sheet was formed under the following conditions. Using polyester resin pre-dried under reduced pressure using a Yamato Scientific DP61 vacuum dryer, the molding material hopper was purged with a drying inert gas (nitrogen gas) to prevent moisture absorption during molding. The plasticization conditions for the M-150C-DM injection molding machine were set as follows: feed screw rotation speed = 70%, screw rotation speed = 120 rpm, back pressure 0.5 MPa, and cylinder temperature set to 45°C, 250°C, and 290°C including the nozzle, starting from directly below the hopper. For injection conditions, the injection speed and holding pressure speed were set to 20%, and the injection pressure and holding pressure were adjusted so that the molded product weight was 146 ± 0.2 g, with the holding pressure set 0.5 MPa lower than the injection pressure. The injection time and holding pressure time were set to an upper limit of 10 seconds and 7 seconds, respectively, and the cooling time was set to 50 seconds. The total cycle time, including the molded product removal time, was approximately 75 seconds. The mold is constantly cooled with 10°C cooling water, but the mold surface temperature when molding is stable is around 22°C. The molded plates used for evaluation were arbitrarily selected from stable molded plates from the 11th to 18th shots after the start of molding, following the introduction of the molding material and resin replacement. The haze of the molded sheet was measured using a haze meter, model NDH2000, manufactured by Nippon Denshoku Co., Ltd., and the transparency was evaluated according to the following criteria. ◎: Haze is less than 5% ○: HAZE is between 5% and 8% △~〇: HAZE is between 8% and less than 10% ×: HAZE is 10% or more

[0104] Chemical resistance Similar to the transparency evaluation described above, a 2mm thick molded plate was manufactured by injection molding. The resulting molded plates were immersed in ethanol at 60°C for 7 hours and visually inspected according to the following criteria. ○: No change △: Slightly bleached ×: Whitening

[0105] Evaluation of thermal oxidation stability (thermal oxidative degradation parameter (TOD)) Polyester resin chips ([IV] i The ) was cryopreserved and ground into a powder of 20 mesh or less. This powder was vacuum dried at 130°C for 12 hours, and 300 mg of the powder was placed in a glass test tube with an inner diameter of approximately 8 mm and a length of approximately 140 mm and vacuum dried at 70°C for 12 hours. Then, a drying tube containing silica gel was attached to the top of the test tube and immersed in a nitrate bath at 200°C under dry air and heated for 15 minutes, after which [IV] f1 The following was measured. TOD was calculated as follows. However, [IV] i and [IV] f1 The values ​​of IV (dL / g) before and after the heating test are shown, respectively. Freeze grinding was performed using a freezer mill (Specx, USA, Model 6750). Approximately 2g of resin chips and a dedicated impactor were placed in a dedicated cell, the cell was set in the apparatus, liquid nitrogen was filled into the apparatus and held for approximately 10 minutes, and then grinding was performed for 5 minutes at RATE 10 (impactor rotations approximately 20 times per second). TOD=0.245{[IV] f1 -1.47 -[IV] i -1.47} A lower TOD value for polyester resin indicates higher thermal oxidation stability.

[0106] Evaluation of thermal stability (thermal decomposition resistance parameter (TD)) Three grams of dried polyester resin chips were placed in a glass test tube and immersed in a 280°C oil bath under a nitrogen atmosphere for 120 minutes to melt them. After heating, [IV] f1The following was measured. TD was calculated as follows. However, [IV] i and [IV] f1 These terms refer to the IV (dL / g) before and after the heating test, respectively. TD = 0.245 {[IV] f1 -1.47 -[IV] i -1.47} For polyester resins, a lower TD value indicates higher thermal stability.

[0107] Synthesis Examples 1-6 (Preparation of Compounds Represented by Formula (I) (Branching Agents)) The compounds represented by formula (I) were prepared in a 2-gallon free radical continuous polymerization reactor system, with reference to Patent Documents 1-3, U.S. Patent Application No. 09 / 354350, and U.S. Patent Application No. 09 / 614402. The compositions and weight-average molecular weights of the compounds represented by formula (I) obtained in Synthesis Examples 1-6 are shown in Table 1 below. The weight-average molecular weight of the compound represented by formula (I) was calculated using GPC on a standard polystyrene basis. Specifically, 4 mg of the compound represented by formula (I) was weighed, dissolved in 4 ml of a mixed solvent of chloroform and isofluoroisopropanol (60 / 40 vol%), filtered through a 0.2 μm membrane filter, and the resulting sample solution was measured using GPC to determine the weight-average molecular weight on a standard polystyrene basis.

[0108] Furthermore, the l, m, and n of the compound represented by formula (I) were determined by 1H-NMR and 13C-NMR analysis. In other words, l, m, and n were expressed as integers, rounded to one decimal place as the average number. Specifically, samples of the compound represented by formula (I) were dissolved in a deuterated chloroform / trifluoroacetic acid mixed solvent (volume ratio 85 / 15) for 1H-NMR and in deuterated chloroform or a deuterated chloroform / hexafluoroisopropanol mixed solvent (volume ratio 1 / 1) for 13C-NMR. The samples were then measured at room temperature using a Fourier transform nuclear magnetic resonance spectrometer (BRUKER AVANCE NEO600) with 50-200 integration cycles (1H-NMR) and 10,000 integration cycles (13C-NMR). The 1H-NMR and 13C-NMR spectra were used to determine the composition of each compound. The ratio of components and the proportion of components located at the end were calculated, and l, m, and n were determined.

[0109] Furthermore, the methacrylic monomer having the structure of formula (II) used in the synthesis example (hereinafter abbreviated as DEMA-BD) can be obtained by methods such as ring-opening glycidyl methacrylate with water and adding a diol. The compound represented by formula (I) may also be obtained by methods such as synthesizing a copolymer of styrene and glycidyl methacrylate (and optionally methyl methacrylate) according to Patent Documents 1-3, U.S. Patent Application No. 09 / 354350, and U.S. Patent Application No. 09 / 614402, and then adding water or a diol.

[0110] [ka]

[0111] The abbreviations used below are: STY = styrene, MMA = methyl methacrylate, and DEMA-BD = methacrylic monomer having the structure of formula (II).

[0112] [Table 1]

[0113] Example 1 In a 10-liter pressure vessel equipped with a stirrer, thermometer, and outlet cooler, 2432 g of terephthalic acid (manufactured by Mitsui Chemicals), 2700 g of 1,4-butanediol, zinc acetate (100 ppm zinc atoms), and 4 g of triethylamine (manufactured by Nacalai Tesque) were charged, and esterification was carried out at 240°C for 3.0 hours under a pressure of 0.35 MPa. The compound represented by formula (I) obtained in Synthesis Example 1 was continuously added to 100% by mass of the alcohol component of the resulting polyester resin, while controlling the flow rate, to a total of 0.2% by mass, and the reaction was carried out stepwise.

[0114] To the mass of polyester resin, 30 ppm of aluminum acetate (as aluminum atoms) and 72 ppm of Irgamod 295 (BASF) (as phosphorus atoms) were added as polycondensation catalysts. Then, 1 ppm of Solvent Blue 45 (Clariant) was added to the polyester resin, and the mixture was stirred at 260°C for 5 minutes under atmospheric pressure and a nitrogen atmosphere. Subsequently, the temperature was raised to 280°C over 60 minutes while gradually lowering the pressure of the reaction system to 13.3 Pa (0.1 Torr), and the polycondensation reaction was carried out at 280°C and 13.3 Pa. Following the release of pressure, the resin was discharged in strand form into cold water under slight pressure and rapidly cooled. After being held in cold water for 20 seconds, it was cut to obtain cylindrical pellets approximately 3 mm in length and 2 mm in diameter.

[0115] Polyester pellets obtained by melt polymerization were dried under reduced pressure (13.3 Pa or less, 80°C, 12 hours), followed by crystallization treatment (13.3 Pa or less, 130°C, 3 hours, and then 13.3 Pa or less, 160°C, 3 hours). After cooling, these polyester pellets were subjected to solid-phase polymerization in a solid-phase polymerization reactor, maintaining the system pressure at 13.3 Pa or less and the temperature at 200°C to 220°C to obtain polyester pellets. The results of each evaluation are shown in Table 2.

[0116] Example 2 In Example 1, the amount of compound represented by formula (I) obtained in Synthesis Example 1 was changed to 0.001% by mass, and polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0117] Example 3 In Example 1, the amount of compound represented by formula (I) obtained in Synthesis Example 1 was changed to 4% by mass, and polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0118] Example 4 In Example 1, the compound represented by formula (I) obtained in Synthesis Example 1 was replaced with the compound represented by formula (I) obtained in Synthesis Example 2, and polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0119] Example 5 In Example 1, the compound represented by formula (I) obtained in Synthesis Example 1 was replaced with the compound represented by formula (I) obtained in Synthesis Example 3, and polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0120] Example 6 In Example 1, the compound represented by formula (I) obtained in Synthesis Example 1 was replaced with the compound represented by formula (I) obtained in Synthesis Example 4, and polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0121] Example 7 In Example 1, the compound represented by formula (I) obtained in Synthesis Example 1 was replaced with the compound represented by formula (I) obtained in Synthesis Example 5 to obtain polyester pellets.

[0122] Example 8 In Example 1, the compound represented by formula (I) obtained in Synthesis Example 1 was replaced with the compound represented by formula (I) obtained in Synthesis Example 6, and polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0123] Example 9 Polymerization was carried out under the same conditions as in Example 1, except that the esterification time was changed to 1.5 hours, to obtain polyester pellets.

[0124] Example 10 Polymerization was carried out under the same conditions as in Example 1, except that the amount of 1,4-butanediol added (2700g) was changed to 2000g and the esterification time was changed to 1.0 hour, to obtain polyester pellets.

[0125] Example 11 Polymerization was carried out under the same conditions as in Example 1, except that the polycondensation catalysts were changed to zinc acetate at 100 ppm zinc atoms and germanium dioxide at 100 ppm germanium atoms relative to the mass of the polyester resin, and triethyl phosphate at 30 ppm phosphorus atoms relative to the mass of the polyester resin, to obtain polyester pellets.

[0126] Example 12 Polymerization was carried out under the same conditions as in Example 1, except that the polycondensation catalyst was changed to tetrabutyl titanium at a concentration of 10 ppm of titanium atoms relative to the mass of the polyester resin, and triethyl phosphate at a concentration of 100 ppm of phosphorus atoms relative to the mass of the polyester resin, to obtain polyester pellets.

[0127] Example 13 In Example 1, polymerization was carried out under the same conditions as in Example 1, except that the amount of ingredients added was changed so that the diol component of the polyester resin was in a ratio of 95 mol% 1,4-butanediol to 5 mol% ethylene glycol, to obtain polyester pellets.

[0128] Example 14 In Example 1, polymerization was carried out under the same conditions as in Example 1, except that the amount of ingredients added was changed so that the diol component of the polyester resin was in the ratio of 1,4-butanediol to ethylene glycol at 87 mol%, to obtain polyester pellets.

[0129] Comparative Example 1 In Example 1, without adding the compound represented by formula (I), polymerization was carried out under the same conditions as in Example 1, except that the polycondensation catalysts were changed to 100 ppm zinc atoms and 100 ppm germanium atoms and 30 ppm phosphorus atoms and 30 ppm phosphorus atoms and 30 ppm triethyl phosphate relative to the mass of the polyester resin.

[0130] Comparative Example 2 In Example 1, the amount of compound represented by formula (I) obtained in Synthesis Example 1 was changed to 0.0001% by mass, and the polycondensation catalysts were changed to 100 ppm zinc atoms relative to the mass of the polyester resin, 100 ppm germanium atoms relative to the mass of the polyester resin, and 30 ppm phosphorus atoms relative to the mass of the polyester resin. Polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0131] Comparative Example 3 In Example 1, the amount of compound represented by formula (I) obtained in Synthesis Example 1 was changed to 6% by mass, and the polycondensation catalysts were changed to 100 ppm zinc atoms relative to the mass of the polyester resin, 100 ppm germanium atoms relative to the mass of the polyester resin, and 30 ppm phosphorus atoms relative to the mass of the polyester resin. Polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0132] Comparative Example 4 In Example 1, the polycondensation catalysts were changed as follows: zinc acetate was changed to 100 ppm zinc atoms and germanium dioxide to 100 ppm germanium atoms relative to the mass of the polyester resin, and triethyl phosphate was changed to 30 ppm phosphorus atoms relative to the mass of the polyester resin. Furthermore, the amount of the charge was changed so that the diol component of the polyester resin was 75 mol% 1,4-butanediol to 25 mol% ethylene glycol. Polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

[0133] Comparative Example 5 In Comparative Example 1, polymerization was carried out under the same conditions as in Comparative Example 1, except that the glycol component of the polyester resin was changed to a ratio of 100 mol% ethylene glycol, to obtain polyester pellets.

[0134] [Table 2]

[0135] In Examples 1 to 14, the melt viscosity was determined at a temperature of 270°C and a shear rate of 30 s. -1 Therefore, the pressure is 26,000 dPa·s or higher, the temperature is 270°C, and the shear rate is 2000 s. -1 And it was below 6500 dPa·s. [Industrial applicability]

[0136] The polyester resin of the present invention is expected to make a significant contribution to industry by improving moldability in extrusion molding, morph extrusion molding, direct blow molding, inflation molding, injection blow molding, and calendering molding, which require high melt tension, and by improving mechanical properties while maintaining transparency.

Claims

1. The compound contains terephthalic acid as a dicarboxylic acid component, ethylene glycol, 1,4-butanediol, and a compound represented by the following formula (I) as alcohol components, wherein terephthalic acid is present in an amount of 85 to 100 mol% of the dicarboxylic acid component, and 1,4-butanediol is present in an amount of 85 to 100 mol% relative to the total amount of ethylene glycol and 1,4-butanediol. The compound represented by formula (I) contains the following copolymer components (M), (N), and (L) as constituent units, where R1 in copolymer component (M) represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, R2, R3, and R4 in copolymer components (N) and (L) each represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and the number of copolymer components (M), (N), and (L) is represented by m, n, and l, respectively, where m and n represent 1 to 1000, and l represents 0 to 1000. The compound represented by formula (I) is a polyester resin characterized by being present in an amount of 0.001 to 5% by mass of the alcohol component in 100% by mass. 【Chemistry 1】

2. The polyester resin according to claim 1, wherein the weight-average molecular weight of the compound represented by formula (I) is 275 or more and 500,000 or less.

3. The melt tension was achieved at a temperature of 270°C, a draw speed of 100 m / min, and a shear speed of 243 s. -1 The polyester resin according to claim 1 or 2, wherein the N is 15 mN or more.

4. The melt viscosity is at a temperature of 270°C and a shear rate of 30 s. -1 Therefore, the pressure is 26,000 dPa·s or higher, the temperature is 270°C, and the shear rate is 2,000 s. -1 The polyester resin according to claim 1 or 2, wherein the pressure is 6500 dPa·s or less.

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