Polyester resin

Abstract

An object of the present application is to provide a polyester resin or the like which is excellent in gelation inhibition, moldability, surface smoothness, transparency, mechanical properties, and heat resistance. The present application relates to a polyester resin characterized by containing, as constituent components of the polyester, a dicarboxylic acid component and an alcohol component, the content of a compound represented by formula (I) in the alcohol component being 0.0002 to 5.9% by weight (in the formula, m and n each are 1 to 1000, 1 represents 0 to 1000, R 1 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, R 2 , R 3 , R 4 each represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms).

Description

Technical Field

[0001] This invention relates to a polyester resin that yields molded articles with excellent formability, transparency, mechanical properties, and heat resistance. Specifically, it relates to a polyester resin that, in addition to improving formability, also improves transparency, heat resistance, mechanical properties, and heat resistance in extrusion molding, profile extrusion molding, direct blow molding, blow molding, injection blow molding, and calendering processes requiring high melt tension. Background Technology

[0002] In recent years, due to issues such as environmental impact, there has been a tendency to replace vinyl chloride resins with other materials. Among several alternative materials, polyester resin has been discussed as a promising material, considering factors such as physical properties, environmental adaptability, adhesive properties, and price.

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

[0004] However, in order to improve the transparency or softness of molded articles using these crystalline polyester resins, various techniques such as controlling cooling conditions during processing or stretching processing become necessary.

[0005] In addition, for profile extrusion molding, direct blow molding, and blow molding that require high melt tension, the draw-down phenomenon is significant, causing the pre-molded part and even the molded part to sag, resulting in uneven thickness and larger burrs in the molded part. Therefore, there are problems with low yield and low stability of continuous production.

[0006] On the other hand, inventions have been disclosed that improve the formability of direct blow molding, which requires high melt tension, by introducing a branched structure (branching agent) into the resin skeleton to solve the problem of sag (for example, Patent Documents 1-3).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent No. 5931061

[0010] Patent Document 2: Japanese Patent No. 5941843

[0011] Patent Document 3: Japanese Patent Application Publication No. 2016-56384 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] However, in the technologies of Patent Documents 1 to 3, the branched structures (branching agents) are highly reactive with each other. Even when mixed with carboxylic acid compounds to react with the components of polyester resin, gels are produced, reducing the solubility of the components of polyester resin. As a result, the resulting polyester resin molded articles have the problem of not achieving good surface smoothness.

[0014] Furthermore, although the sag phenomenon has been improved in patent documents 1-3, the excessively high melt tension causes problems such as reduced surface smoothness and decreased transparency of the molded product due to melt fracture when the resin is ejected from the die during molding. Additionally, heat resistance is also required for polyester resin molded products.

[0015] Furthermore, cyclic oligomers (including tetramers) are generated during the manufacturing process of polyester resin. These cyclic oligomers contaminate the mold during processing, leading to a decrease in continuous formability.

[0016] This invention addresses issues related to existing technologies. The object of this invention is to provide a polyester resin from which molded articles exhibiting excellent gelation inhibition, formability, surface smoothness, transparency, mechanical properties, and heat resistance are obtained. Furthermore, for issues not essential to this invention, it also includes providing a polyester resin capable of producing molded articles with low cyclic oligomer content and excellent continuous formability.

[0017] More specifically, the subject of this invention is to provide a polyester resin that exhibits excellent gelation inhibition, surface smoothness, transparency, mechanical properties, and heat resistance, and can produce molded articles with excellent formability in extrusion molding, profile extrusion molding, direct blow molding, blow molding, injection blow molding, and calendering, which require high melt tension.

[0018] Technical means to solve the problem

[0019] After conducting in-depth research to achieve the above objectives, the inventors discovered that the aforementioned problems can be solved and the present invention realized by means of the following methods. Specifically, the present invention has the following structure.

[0020] [1] A polyester resin, characterized in that, as a component of the polyester, it contains a dicarboxylic acid component and an alcohol component, wherein, in 100% by weight of the alcohol component, the content of the compound represented by formula (I) is 0.0002 to 5.9% by weight.

[0021] [Chemical Formula 1]

[0022]

[0023] (In the formula, m and n are each 1 to 1000, l represents 0 to 1000, and R...) 1 R represents an aromatic hydrocarbon group with 6 to 20 carbon atoms. 2 R 3 R 4 Each is represented as either a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0024] [2] The polyester resin according to [1] is characterized in that the weight average molecular weight of the compound represented by formula (I) is more than 200 and less than 500,000.

[0025] [3] The polyester resin according to [1] or [2] is characterized in that 100 mol% of the dicarboxylic acid component contains 85 to 100 mol% of terephthalic acid, and as an alcohol component it contains ethylene glycol.

[0026] [4] The polyester resin according to claims [1] to [3] is characterized in that the content of cyclic oligomer tetramer in the polyester resin is less than 2680 ppm.

[0027] [5] The polyester resin according to claims [1] to [4] is characterized in that, at a temperature of 270°C, a traction speed of 100 m / min, and a shear speed of 243 s -1 The lower melt tension is above 15mN.

[0028] [6] The polyester resin according to claims [1] to [5] is characterized in that, at a temperature of 270°C and a shear rate of 30s... -1 The melt viscosity is above 26000 dPa·s; at a temperature of 270℃ and a shear rate of 2000 s⁻¹. -1 The melt viscosity is below 6500 dPa·s.

[0029] The effects of the invention

[0030] According to the present invention, molded articles of polyester resin with excellent gelation inhibition, formability, surface smoothness, transparency, mechanical properties and heat resistance are obtained.

[0031] In particular, compared to the past, it exhibits excellent formability in extrusion molding, profile extrusion molding, direct blow molding, blow molding, injection blow molding, and calendering, which require high melt tension.

[0032] Furthermore, as for the non-essential effects of the present invention, it includes the ability to obtain molded articles of polyester resin with low cyclic oligomer content and excellent continuous formability. Detailed Implementation

[0033] 1. Polyester resin

[0034] The polyester resin of the present invention is characterized in that, as a component of the polyester, it contains a dicarboxylic acid component and an alcohol component (preferably a polyol component), and the content of the compound represented by formula (I) is 0.0002 to 5.9% by weight of the alcohol component in 100% by weight. Compared with conventional branching agents, the compound represented by formula (I) has a modified glycidyl group (epoxy group), and can react with the components of the polyester resin without side reactions such as the formation of gels between the compounds represented by formula (I).

[0035] [Chemical Formula 2]

[0036]

[0037] (In the formula, m and n are each 1 to 1000, l represents 0 to 1000, and R...) 1 R represents an aromatic hydrocarbon group with 6 to 20 carbon atoms. 2 R 3 R 4 Each is represented as either a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0038] The polyester resin of the present invention is characterized in that it is a polymer containing a specified dicarboxylic acid component and an alcohol component, wherein the content of the compound represented by formula (I) as the alcohol component is a specified amount.

[0039] In this invention, the compound represented by formula (I) is a branching agent for polyester resin and is used as an alcohol component together with a commonly used diol component (hereinafter referred to as diol component). As long as it is bonded to the polyester resin chain at an appropriate stage, the compound represented by formula (I) can exist as a compound in the resin composition. The compound of formula (I) is preferably present in a state combined with the carboxylic acid component of the polyester resin.

[0040] The compound represented by formula (I) has an average of more than two (preferably more than three) functional groups (hydroxyl groups) per molecule that can react with the carboxyl groups of the dicarboxylic acid component, and can partially introduce a branched structure into the polyester resin as a whole.

[0041] Thus, because the polyester resin of the present invention uses the compound represented by formula (I), gelation is suppressed, the melt tension decreases at higher temperatures during melt extrusion, and the melt viscosity decreases under high shear, so no melt fracture occurs during molding, and the formability, surface smoothness, transparency, mechanical properties and heat resistance also become excellent.

[0042] Furthermore, because polyester resin contains a low content of cyclic oligomers, it is less likely to contaminate the mold during processing, thus improving continuous molding performance.

[0043] The compound represented by formula (I) is as follows.

[0044] [Chemical Formula 3]

[0045]

[0046] (In the formula, m and n are each 1 to 1000, l represents 0 to 1000, and R...) 1 R represents an aromatic hydrocarbon group with 6 to 20 carbon atoms. 2 R 3 R 4 Each is represented as either a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0047] R 1 It represents aromatic hydrocarbon groups with 6 to 20 carbon atoms.

[0048] As R 1 Examples of aromatic hydrocarbon groups representing 6 to 20 carbon atoms include: phenyl, o-tolyl, m-tolyl, p-tolyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2,3-xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl, 3,4-xylyl, 3,5-xylyl, 4-vinylphenyl, o-isopropylphenyl, m-isopropylphenyl, p-isopropylphenyl, o-tert-butylphenyl, m-tert-butylphenyl, p-tert-butylphenyl, 3,5 -Di(tert-butyl)phenyl, 3,5-di(tert-butyl)-4-methylphenyl, 4-butylphenyl, 4-pentylphenyl, 2,6-bis(1-methylethyl)phenyl, 2,4,6-tris(1-methylethyl)phenyl, 4-cyclohexylphenyl, 2,4,6-trimethylyl, 4-octylphenyl, 4-(1,1,3,3-tetramethylbutyl)phenyl, 1-naphthyl, 2-naphthyl, 5,6,7,8-tetrahydro-1-naphthyl, 5,6,7,8-tetrahydro-2-naphthyl, fluorene, etc.

[0049] The aromatic hydrocarbon group preferably has 6 to 18 carbon atoms, more preferably 6 to 15, and even more preferably 6 to 12.

[0050] Among them, the aromatic hydrocarbon group is particularly preferred to be phenyl, o-tolyl, m-tolyl, and p-tolyl, with phenyl being the most preferred.

[0051] R 2 R 3 R 4 It refers to an alkyl group having 1 to 10 hydrogen atoms or carbon atoms.

[0052] As R 2 R 3 R 4Alkyl groups representing 1 to 10 carbon atoms include: straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl; and isopropyl, isobutyl, sec-butyl, tert-butyl, 2-ethylbutyl, 3,3-dimethylbutyl, 1,1,3,3-tetramethylbutyl, 1-methylbutyl, 1-ethylpropyl, 3-methylbutyl, neopentyl, 1,1-dimethylpropyl, 2-methylpentyl, 3-ethylbutyl... 1,3-Dimethyl-1,2-dimethyl-1,3-butyl-1,3-propyl-1,3-dimethyl-1,3-ethyl-1,3-dimethyl-1,3- ... - Branched alkyl groups such as propylhexyl, 1-butylpentyl, 1-methylnonyl, 1-ethyloctyl, 1-propylheptyl, and 1-butylhexyl; cyclopropyl, 1-methylcyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, 1-methylcyclohexyl, 2-methylcyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 1,2-dimethylcyclohexyl, 1,3-dimethylcyclohexyl, 1,4-dimethylcyclohexyl, 2,3-dimethylcyclohexyl, etc. Cyclohexyl groups, including methylcyclohexyl, 2,4-dimethylcyclohexyl, 2,5-dimethylcyclohexyl, 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, etc.

[0053] The alkyl group preferably has 1 to 8 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 4.

[0054] Among them, alkyl groups are particularly preferred to be methyl, ethyl, propyl, and butyl, with methyl being the most preferred.

[0055] R 2 and R 3 Preferably, it is an alkyl group having 1 to 10 carbon atoms, R 4 Hydrogen atoms are preferred.

[0056] The above l, m, and n are the ratios of the copolymer components (L), (M), and (N) contained in one molecule, and are integer values ​​(ratios) rounded to one decimal place. The ratios and average number of components in one molecule are derived from... 1 H-NMR analysis and 13 Obtained from C-NMR analysis.

[0057] [Chemical Formula 4]

[0058]

[0059] The values ​​of m and n used in representing the ratio as integers can be the same or different, and can be expressed as 1 to 1000, preferably 2 to 800, more preferably 5 to 600, and even more preferably 10 to 400.

[0060] l is 0 to 1000, preferably 1 to 700, more preferably 2 to 400, and even more preferably 5 to 100.

[0061] The compound represented by formula (I) can be a random copolymer formed by random copolymerization of copolymer components (L), (M), and (N), or a block copolymer in which at least one of copolymer components (L), (M), and (N) is a block copolymer, preferably a random copolymer.

[0062] The polyester resin of the present invention can be one or more polyester resins as long as it satisfies the above m, n, l.

[0063] The compound represented by formula (I), as described in, for example, Patent Documents 1-3, U.S. Patent Application No. 09 / 354350 and U.S. Patent Application No. 09 / 614402, can be prepared in a 2-gallon free radical continuous polymerization reactor system, and the compound can be further modified with epoxy groups.

[0064] The content of the compound represented by formula (I) in 100% by weight of alcohol components that are constituents of polyester resin is 0.0002 to 5.9% by weight, preferably 0.0005 to 5.0% by weight, more preferably 0.001 to 4.5% by weight, further preferably 4.0% by weight or less, and particularly preferably 3.5% by weight or less.

[0065] When the content of the compound represented by formula (I) is less than 0.0002% by weight, there is a tendency for sag during molding, unstable molding, or even if it can be molded, it will result in molded articles with uneven thickness. Furthermore, when the content of the compound represented by formula (I) exceeds 5.9% by weight, gelation occurs, melt fracture occurs during molding, surface smoothness becomes poor, and the molded article loses its transparency. In addition, there is a tendency for it to become a low-quality molded article containing gel.

[0066] The compound represented by formula (I) may have a specified weight-average molecular weight. The weight-average molecular weight of the compound represented by formula (I) is preferably 200 or more and 500,000 or less, more preferably 500 or more, even more preferably 700 or more, and even more preferably 1,000 or more; more preferably 300,000 or less, even more preferably 100,000 or less, and even more preferably 50,000 or less.

[0067] If the weight-average molecular weight of the compound represented by Formula (I) is less than 200, unreacted compounds may seep out onto the surface of the molded article, raising concerns about surface contamination. On the other hand, if the weight-average molecular weight of the compound represented by Formula (I) exceeds 500,000, molded articles made of polyester resin may experience reduced compatibility between the compound and the polyester during bending, potentially leading to voids and whitening.

[0068] For example, the weight-average molecular weight can be obtained from the GPC converted from standard polystyrene.

[0069] Specifically, by weighing 4 mg of the compound sample 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, and providing the resulting sample solution to GPC, the weight-average molecular weight is calculated by converting it to standard polystyrene.

[0070] The dicarboxylic acid and diol components used in this invention are as follows.

[0071] Examples of dicarboxylic acid components include: oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebaceous 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 acids, etc., which are examples of saturated aliphatic dicarboxylic acids or their ester-forming derivatives (e.g., alkyl esters with 1 to 20 carbon atoms); fumaric acid, maleic acid, itaconic acid, etc., which are examples of unsaturated aliphatic dicarboxylic acids or their ester-forming derivatives (e.g., alkyl esters with 1 to 20 carbon atoms); and fumaric acid, maleic acid, itaconic acid, etc., which are examples of unsaturated aliphatic dicarboxylic acids or their ester-forming derivatives (e.g., alkyl esters with 1 to 20 carbon atoms). Alkyl esters having 1 to 20 atoms; aromatic dicarboxylic acids or their ester-forming derivatives, such as phthalic acid, isophthalic acid, terephthalic acid, 5-(alkali metal)sulfonic acid isophthalic acid, biphenyl dicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, papoic acid, anthracene dicarboxylic acid, etc. (e.g., alkyl esters having 1 to 20 carbon atoms, preferably dimethyl terephthalate).

[0072] Among these dicarboxylic acid components, isophthalic acid, terephthalic acid, and naphthalic acid are preferred, and from the viewpoint of the physical properties of the resulting polyester resin, terephthalic acid is particularly preferred.

[0073] In addition to the dicarboxylic acids mentioned above, small amounts of tri- to quadri-carboxylic acids may also be used.

[0074] Examples of such carboxylic acids include: ethanetricarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, pyromellitic acid, 3,3,3',4'-biphenyltetracarboxylic acid, and their ester-forming derivatives (e.g., alkyl esters having 1 to 20 carbon atoms).

[0075] As an alcohol component, a diol component is used together with the compound represented by formula (I). Of 100% by weight of the alcohol component, the diol component (excluding the compound represented by formula (I)) is preferably 99.9998–94.1% by weight, more preferably 99.9995–95% by weight, even more preferably 99.999–95.5% by weight, particularly preferably 96% by weight or more, and most preferably 96.5% by weight or more.

[0076] The preferred diol component is ethylene glycol. Ethylene glycol preferably contains 85 mol% or more of the diol component per 100 mol%, more preferably 85-99 mol%.

[0077] Examples of diols that can be used besides ethylene glycol include: 1,2-propanediol, 1,3-propanediol, diethylene glycol, triethylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentanediol, 1,6-hexanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanediethanol, 1,3-cyclohexanediethanol, 1,4-cyclohexyldiethanol, 1,10-decanediol, 1,12-dodecanediol, isosorbide diol, polyethylene glycol (4... Aliphatic diols such as those with more than one ethylene structural unit, polytrimethylene glycol, polytetramethylene glycol, fluorene glycol, etc.; aromatic diols such as hydroquinone, 4,4'-dihydroxybisphenol, 1,4-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, diols to which ethylene oxide is added, or hydrides of bisphenol A, F, S, C, etc.

[0078] In addition to the diols mentioned above, 3- to 4-membered alcohols, hydroxycarboxylic acids, cyclic esters, etc., can also be used as diol components.

[0079] Examples of this type of alcohol include: trimethylolpropane, trimethylolpropane, pentaerythritol, glycerol, and hexanetriol.

[0080] Examples of such hydroxycarboxylic acids include: lactic acid, citric acid, malic acid, tartaric acid, glycolic acid, 3-hydroxybutyric acid, p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, 4-hydroxycyclohexanecarboxylic acid, or their ester-forming derivatives (e.g., alkyl esters having 1 to 20 carbon atoms).

[0081] Examples of cyclic esters include: ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, lactide, etc.

[0082] The polyester resin of the present invention contains 80-100 mol% terephthalic acid in 100 mol% of the dicarboxylic acid component, and preferably contains ethylene glycol as the alcohol component (more precisely, the diol component). Preferably, the ethylene glycol contains 85-99 mol% in 100 mol% of the diol component.

[0083] In 100 mol% of dicarboxylic acid, terephthalic acid more preferably contains 90-100 mol%, and even more preferably 95-100 mol%; in 100 mol% of diol, ethylene glycol more preferably contains 90-99 mol%, and even more preferably 95-99 mol%.

[0084] The polyester resin of the present invention is preferably a copolymerized polyethylene terephthalate resin.

[0085] The polyester resin of the present invention is a crystalline polyester resin with a branched structure. While improving processability such as formability by increasing the "melt strength enhancement effect" brought about by increasing the molecular weight, adjusting the melt viscosity and melt tension can suppress the whitening resistance of the molded article and the exudation of unreacted substances on the surface of the molded article.

[0086] If the content of terephthalic acid and ethylene glycol exceeds the above range, it becomes an amorphous polyester resin, which cannot be made into high viscosity through solid-state polymerization, raising concerns that molded products with high mechanical properties cannot be obtained.

[0087] Furthermore, in the polyester resin of the present invention, it is preferable to reduce the content of cyclic oligomers, which are preferably tetramers, more preferably tetramers obtained by reacting terephthalic acid with ethylene glycol (hereinafter also referred to as CT4), that is, cyclic tetramers are synthesized by bonding in the order of terephthalic acid, ethylene glycol, terephthalic acid, ethylene glycol, terephthalic acid, ethylene glycol, terephthalic acid, ethylene glycol.

[0088] The content of cyclic oligomer tetramers in the polyester resin is preferably less than 2680 ppm, more preferably less than 2650 ppm, and even more preferably less than 2600 ppm; preferably more than 0 ppm, more preferably more than 1 ppm, even more preferably more than 10 ppm, and even more preferably more than 100 ppm.

[0089] Because free CT4 levels are below 2680 ppm, exudation to the surface of molded products can be suppressed, improving the transparency of molded products or films and maintaining their high quality. Furthermore, sufficient transparency can be maintained even for thick-walled molded products or films. However, if CT4 levels are above 2680 ppm, contamination near the resin outlet of the extruder die or the mold of the injection molding machine tends to become very serious during continuous film formation and fiber extrusion. Furthermore, free CT4 exuded from the surface of the molded product adheres to the surface of the film, molded product, or fiber, tending to reduce its commercial value.

[0090] These mechanisms are not yet clear, but it is believed that as a component of polyester, it contains dicarboxylic acid and alcohol components. By making the content of the compound represented by formula (I) 0.0002 to 5.9% by weight in 100% by weight of alcohol components, the structure of formula (I) constitutes the steric hindrance when forming the CT4 ring, and thus the free CT4 is less than 2680 ppm.

[0091] The polyester resin of the present invention can have a specified intrinsic viscosity IV. This 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.

[0092] This intrinsic viscosity can be measured at 30°C using an Orstau viscometer by dissolving the polyester resin in a mixed solvent of p-chlorophenol / tetrachloroethane (3 / 1 by weight).

[0093] The acid value (AV) of the polyester resin used in this invention is preferably 100 eq / 10. 6 g (ton) or less, more preferably 60 eq / 10 6 g (ton) or less, more preferably 50 eq / 10 6 Below g(ton). On the other hand, the lower the lower limit, the better, preferably close to 0eq / 10. 6 Approximately g. If the acid value exceeds 100 eq / 10 6 g, then there is a tendency for gelation to occur, and for surface properties or haze to decrease.

[0094] The acid value can be determined by dissolving the polyester resin sample in alcohol and ether solutions, using phenolphthalein reagent as an indicator, and titrating with an alcoholic sodium hydroxide solution or an alcoholic potassium hydroxide solution. Specific methods for determining the acid value are shown in the examples.

[0095] The polyester resin of the present invention may have a specified melting point. The preferred melting point of the polyester resin is 200-300°C, more preferably 220-280°C, further preferably 240-260°C, and even more preferably 250°C or higher.

[0096] The melting point can be determined using a differential scanning calorimeter (DSC) by heating the temperature to 300°C at a rate of 20°C / min, and the maximum peak temperature of the heat of fusion is taken as the crystallization melting point.

[0097] The polyester resin of the present invention is preferably manufactured by a polymerization catalyst comprising at least an aluminum compound and a phosphorus compound, preferably containing 3 to 1000 ppm aluminum and 5 to 10000 ppm phosphorus from the polymerization catalyst.

[0098] Other polymerization catalysts may be selected from one or more titanium compounds and germanium compounds, or a combination of phosphorus compounds and germanium compounds.

[0099] The aluminum compound is preferably selected from at least one of aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, and basic aluminum chloride, more preferably from at least one of aluminum acetate and basic aluminum acetate, and even more preferably from aluminum acetate.

[0100] The aluminum content relative to the total mass of the polyester resin, calculated on an aluminum atomic basis, is preferably 3 to 1000 ppm, more preferably 5 to 800 ppm, and even more preferably 8 to 500 ppm. Insufficient aluminum content raises concerns about decreased polymerization activity; excessive aluminum content raises concerns about increased generation of aluminum-derived foreign matter.

[0101] A phosphorus compound used as a polymerization catalyst together with an aluminum compound is described. The phosphorus compound is preferably selected from at least one of phosphonic acid compounds and hypophosphonic acid compounds, and more preferably a phosphonic acid compound.

[0102] The phosphorus compound preferably has a phenolic structure within the same molecule, more preferably is selected from at least one of phosphonic acid compounds and hypophosphonic acid compounds having a phenolic structure within the same molecule, and even more preferably is a phosphonic acid compound having a phenolic structure within the same molecule.

[0103] Examples of phosphorus compounds containing a phenolic structure within the same molecule include: p-hydroxyphenylphosphonic acid, dimethyl p-hydroxyphenylphosphonate, diethyl p-hydroxyphenylphosphonate, diphenyl p-hydroxyphenylphosphonate, bis(p-hydroxyphenyl)phosphonic acid, methyl bis(p-hydroxyphenyl)phosphonate, phenyl bis(p-hydroxyphenyl)phosphonate, p-hydroxyphenylphenylphosphonic acid, methyl p-hydroxyphenylphenylphosphonate, phenyl p-hydroxyphenylphenylphosphonate, p-hydroxyphenylphenylphosphonic acid, methyl p-hydroxyphenylphosphonate, phenyl p-hydroxyphenylphosphonate, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, etc.

[0104] The phosphorus compound is particularly preferred to be diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate. For example, Irgamod 295 (manufactured by BASF) can be used as the phosphorus compound.

[0105] The phosphorus content relative to the total mass of the polyester resin, calculated in terms of phosphorus atoms, is preferably 5 to 10,000 ppm, more preferably 8 to 8,000 ppm, and even more preferably 10 to 6,000 ppm. Too few phosphorus atoms raise concerns about decreased polymerization activity and increased generation of aluminum-derived foreign matter; too many phosphorus atoms raise concerns about increased catalyst costs.

[0106] Examples of titanium compounds include: tetrabutyltitanium, tetrabenzyltitanium, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetraisobutyl titanate, tetra-tert-butyl titanate, tetracyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate, lithium titanium oxalate, potassium titanium oxalate, ammonium titanium oxalate, titanium oxide, composite oxides of titanium with silicon, zirconium, alkali metals, or alkaline earth metals, titanium orthoesters or condensed orthoesters, reaction products of titanium orthoesters or condensed orthoesters with hydroxycarboxylic acids, reaction products of titanium orthoesters or condensed orthoesters with hydroxycarboxylic acids and phosphorus compounds, reaction products of titanium orthoesters or condensed orthoesters with polyols having at least two hydroxyl groups, 2-hydroxycarboxylic acids, and bases, etc., preferably titanium orthoesters or condensed orthoesters with silicon, titanium orthoesters or condensed orthoesters with hydroxycarboxylic acids and phosphorus compounds.

[0107] The titanium content relative to the total mass of the polyester resin, calculated as titanium atoms, is preferably 1 to 300 ppm, more preferably 2 to 200 ppm, and even more preferably 3 to 100 ppm.

[0108] Examples of germanium compounds include germanium dioxide and germanium acetate. Among these, germanium dioxide is preferred.

[0109] The germanium content relative to the total mass of the polyester resin, calculated in terms of germanium atoms, is preferably 1 to 500 ppm, more preferably 2 to 400 ppm, and even more preferably 3 to 300 ppm.

[0110] The amount of the aforementioned atoms can also be calculated, for example, by fluorescence X-ray analysis.

[0111] In addition, as phosphorus compounds used together with germanium compounds, phosphoric acid and trimethyl phosphate, triethyl phosphate, phenyl phosphate, triphenyl phosphate and other phosphate esters, phosphorous acid and trimethyl phosphite, triethyl phosphite, triphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tetra(2,4-di-tert-butylphenyl)4,4'-biphenyl diphosphite and other phosphites can also be used.

[0112] The polyester resin of the present invention preferably has a specified melt tension and melt viscosity when melted.

[0113] The polyester resin of the present invention has the property that the higher the temperature, the lower the melt tension when the temperature is above 250°C.

[0114] In this invention, from the viewpoint of exhibiting properties equal to or higher than those of high-density polyethylene, the following conditions were met: temperature 270°C, traction speed 100 m / min, and shear speed 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; the upper limit of the melt tension is, for example, 170 mN or less or 120 mN or less.

[0115] This melt tension is measured, for example, under specified conditions (capillary length 10 mm, capillary diameter 1 mm, temperature 270 °C, shear rate 243 s). -1 The maximum traction speed is 200 m / min, the initial traction speed is 10 m / min, or the constant traction speed is 100 m / min, and the traction time is 90 seconds. This can be obtained using a capillary rheometer.

[0116] The polyester resin of the present invention has a shear rate of 2000 s during melting. -1 Below 250℃, the higher the temperature, the lower the melt tension.

[0117] In this invention, from the viewpoint of suppressing melt fracture during melt extrusion, the melt viscosity is preferably at a temperature of 270°C and a shear rate of 30 s. -1 The shear rate is above 26000 dPa·s; at a temperature of 270℃ and a shear rate of 2000 s. -1 The temperature is below 6500 dPa·s. The polyester resin of the present invention exhibits thixotropy at high temperatures during melting, which can suppress melt fracture and obtain good formability.

[0118] Melt viscosity at 270℃ and shear rate 30s -1 When the viscosity is 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 lower or 45,000 dPa·s or lower.

[0119] Melt viscosity can be determined based on, for example, JIS K7199. Melt viscosity at a temperature of 270°C and a shear rate of 2000 s⁻¹. -1 When the viscosity is 6500 dPa·s or less, more preferably 6300 dPa·s or less, and even more preferably 6200 dPa·s or less, the upper limit of the melt viscosity is, for example, 5500 dPa·s or more.

[0120] The melt viscosity is determined, for example, under specified conditions (capillary length 10 mm, capillary diameter 1 mm, temperature 270 °C, shear rate 30 s). -1 Or 2000s -1 The result can be obtained using a capillary rheometer.

[0121] From the viewpoint of heat resistance, the polyester resin of the present invention can also have a specified heat resistance oxidative decomposition parameter (TOD), which is preferably 0.390 or less. TOD can be calculated by the method described in the following examples. 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 this TOD is, for example, 0.010 or more, 0.015 or more, or 0.020 or more. If the TOD exceeds 0.390, there is a concern about a decrease in formability during draping.

[0122] The polyester resin of the present invention may also contain organic, inorganic, and organometallic colorants, as well as additives such as fluorescent whitening agents. By containing one or more of these additives, the yellowing and other coloring of the polyester resin can be suppressed to a more excellent level. Furthermore, it may also contain any other polymers or electrophoretic agents, defoamers, dyeing modifiers, dyes, pigments, matting agents, fluorescent whitening agents, stabilizers, antioxidants, and other additives. As antioxidants, aromatic amines, phenols, and other antioxidants can be used; as stabilizers, phosphorus-based, sulfur-based, amine-based, and other phosphoric acid or phosphate ester-based stabilizers can be used.

[0123] In addition, the polyester resin can be pre-treated as described above, and then introduced into a direct molding process in a molten state after the melt polycondensation process, or after further solid-state polymerization or other treatments, to form a molded article. Alternatively, a specified amount of additives, such as crystallization habit modifiers, formaldehyde depressants, color modifiers, and stabilizers, can be added to any reactor or pipeline in the melt polycondensation polymer manufacturing process. After the melt polycondensation process imparts the desired properties, the resin can be directly introduced into a direct molding process, or further, after solid-state polymerization or other treatments, to form a molded article.

[0124] Polyester resin molded articles made from the polyester resin of the present invention can have a specified three-dimensional center surface average roughness (SRa). The SRa of the polyester resin molded articles is preferably less than 0.15 μm, more preferably less than 0.14 μm, further preferably less than 0.13 μm, even more preferably less than 0.12 μm, preferably more than 0.01 μm, or more than 0.02 μm.

[0125] The average roughness (SRa) of the three-dimensional center surface involved can be obtained, for example, using a surface roughness measuring instrument (a pocket-sized measuring instrument, Kosaka Laboratory's Surfcorder ET 4000A).

[0126] 2. Manufacturing method of polyester resin

[0127] The polyester resin of the present invention can be manufactured by existing known methods. For example, in the case of manufacturing PET, a direct esterification method is used, in which terephthalic acid and ethylene glycol, and other copolymers as needed, are directly reacted, water is removed by distillation and esterification is performed, followed by polycondensation under reduced pressure; or, a transesterification method is used, in which dimethyl terephthalate is reacted with ethylene glycol and other copolymers as needed, methanol is removed by distillation and transesterification is performed, followed by polycondensation under reduced pressure. Further, if necessary, solid-state polymerization can be carried out to increase its intrinsic viscosity. To promote crystallization before solid-state polymerization, the molten polymerized polyester can be heated to crystallize after absorbing moisture, or water vapor can be directly blown onto the polyester sheet to cause it to crystallize.

[0128] 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 also be added dispersedly during addition.

[0129] The polycondensation reaction can be carried out in a batch reactor or a continuous reactor. In either of these methods, the esterification or transesterification reaction can be carried out in one stage or in multiple stages. The polycondensation reaction can be carried out in one stage or in multiple stages. The solid-state polymerization reaction is the same as the polycondensation reaction and can be carried out in a batch reactor or a continuous reactor. Polycondensation and solid-state polymerization can be carried out continuously or separately.

[0130] The following example, using PET as an example of a polyester resin, illustrates a preferred continuous manufacturing method.

[0131] In a multi-stage apparatus using 1 to 3 esterification reactors connected in series, under ethylene glycol reflux conditions, the water or alcohol produced in the reaction is removed from the system via a distillation column while the esterification reaction is carried out. The preferred temperature for the first stage of the esterification reaction is 240–270°C, more preferably 245–265°C; the preferred pressure is 0.2–3 kg / cm³. 2 G, more preferably 0.5–2 kg / cm³ 2 G. The temperature of the final esterification reaction is typically 250–290°C, preferably 255–275°C; the pressure is typically 0–1.5 kg / cm². 2 G, more preferably 0–1.3 kg / cm³ 2G. When the esterification reaction is carried out in three or more stages, the reaction conditions for the intermediate esterification stages are between the reaction conditions for the first stage and the final stage described above. The increase in the reaction rate of these esterification reactions is preferably distributed smoothly across each stage. The final esterification rate is preferably 90% or more, more preferably 93% or more. Through these esterification reactions, low-order condensates with a molecular weight of approximately 500 to 5000 can be obtained.

[0132] When the above esterification reaction uses terephthalic acid as a raw material, the reaction can be carried out even without a catalyst due to the catalytic effect of terephthalic acid as an acid, but it can also be carried out in the presence of polycondensation catalysts.

[0133] Furthermore, if 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, as well as alkaline compounds such as lithium carbonate, sodium carbonate, potassium carbonate, and sodium acetate are added for polycondensation, the proportion of dioxyethylene terephthalate components in the polyethylene terephthalate backbone can be kept at a low level (less than 5 mol% relative to the total glycol content), which is therefore preferred.

[0134] Secondly, when producing oligomers via transesterification, a solution containing preferably 1.1 to 3.0 moles, more preferably 1.2 to 2.5 moles of ethylene glycol relative to 1 mole of dimethyl terephthalate is prepared and continuously supplied to the transesterification process.

[0135] In a device using one or two esterification reactors connected in series, under ethylene glycol reflux conditions, the methanol produced in the reaction is discharged from the system through a distillation column while the transesterification reaction is carried out. The temperature of the first-stage esterification reaction is preferably 180–250°C, more preferably 200–240°C. The temperature of the final-stage esterification reaction is typically 230–270°C, preferably 240–265°C. As a transesterification catalyst, fatty acid salts or carbonates of Zn, Cd, Mg, Mn, Co, Ca, Ba, etc., or oxides of Pb, Zn, Sb, Ge, etc., can also be used. Through these transesterification reactions, low-order condensates with molecular weights of approximately 200–500 can be obtained.

[0136] Next, the resulting low-order condensate is fed into a multi-stage liquid-phase polycondensation process. The polycondensation reaction conditions are as follows: the reaction temperature for the first stage is preferably 250–290°C, more preferably 260–280°C; the pressure is preferably 500–20 Torr, more preferably 200–30 Torr; the reaction temperature for the final stage is preferably 265–300°C, more preferably 275–295°C; the pressure is preferably 10–0.1 Torr, more preferably 5–0.5 Torr. When the reaction is carried out in three or more stages, the reaction conditions for the intermediate stages of polycondensation are between the reaction conditions for the first stage and the final stage. Preferably, the increase in intrinsic viscosity is smoothly distributed throughout each of these polycondensation reaction steps.

[0137] The resulting condensation polyester resin is then subjected to solid-state polymerization. The polyester resin is solid-state polymerized according to a known method. First, the polyester resin supplied for solid-state polymerization is heated for 1 to 5 hours under an inert gas or reduced pressure, or in an atmosphere of water vapor or an inert gas containing water vapor, for example, at a temperature of 100–190°C, for pre-crystallization. Then, solid-state polymerization is carried out for 1 to 50 hours under an inert gas atmosphere or reduced pressure at a temperature of 190–230°C.

[0138] The catalysts used in this invention are active not only in polycondensation reactions but also in esterification and transesterification reactions. For example, the catalysts can also be used in transesterification reactions with alkyl esters of dicarboxylic acids such as dimethyl terephthalate and diols such as ethylene glycol. Furthermore, the catalysts used in this invention are active not only in melt polymerization but also in solid-state polymerization and solution polymerization, and polyester resins can be manufactured according to any method.

[0139] 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 to the reaction system before the start of esterification or transesterification, at any stage during the reaction, just before the start of polycondensation, or at any stage during polycondensation. In particular, ammonium or ammonium compounds are preferably added just before the start of polycondensation.

[0140] The polymerization catalyst other than phosphorus compounds used in this invention can be added in powder or pure form without solvent, or in a slurry or solution form with a solvent such as ethylene glycol, without particular limitation. Furthermore, ammonium or ammonium compounds or phosphorus compounds can be added as a mixture pre-mixed with other components, or they can be added separately. Additionally, ammonium or ammonium compounds or phosphorus compounds can be added to the polymerization system at the same time as other components, or the components can be added at different times. Furthermore, the entire amount of catalyst can be added at once, or it can be added in several stages.

[0141] The polyester resin of this invention is preferably used for blow molding (preferably direct blow molding) after polycondensation and solid-state polymerization. In the blow molding of heat-resistant bottles, a preform with a bottom is generally made, and the preform is blow-stretched in a mold, or further heat-set. The preform can be manufactured using compression molding, injection molding, or other methods. Taking injection molding as an example, the preform is obtained by heating and melting to 260-350°C and injecting it into a mold. Typically, the preform is a thick-walled experimental tubular shape with a gate at the bottom and a cap thread at the stopper.

[0142] For heat-resistant bottles, the stopper portion of the resulting preform can be crystallized. By crystallizing, deformation of the stopper portion can be prevented even when filled with high-temperature contents. Crystallization of the stopper portion is preferably performed by heating to 130–200°C, more preferably to 140–190°C. As a heating method, infrared heaters, hot air, induction heating, oil bath immersion, etc., can be used; from a production perspective, infrared heaters are preferred. It should be noted that the heat crystallization of the stopper portion can also be performed after blow molding.

[0143] A preform is heated and stretched along the length (longitudinal direction) of the bottle while simultaneously being blow-molded circumferentially to obtain the bottle. Stretching along the length is typically done using a rod-shaped stretching rod, while pressurized gas such as air or nitrogen is used in the circumferential direction. The pressurized gas pressure is preferably 1–10 MPa. A preferred method is to insert the stretching rod while simultaneously blowing in pressurized gas, stretching both longitudinally and circumferentially; however, stretching can also be done longitudinally first, followed by circumferential stretching. Heating is achieved using infrared heaters, hot air, induction heating, or other methods. The heating temperature is typically 80–130°C, preferably 90–120°C.

[0144] The lower limit of the elongation ratio along the length of the bottle is preferably 1.5 times, more preferably 2 times. If it is less than the above ratio, uneven stretching will occur. The upper limit of the elongation ratio along the length of the bottle is preferably 6 times, more preferably 5 times, and even more preferably 4 times. If it exceeds the above ratio, breakage is likely to occur.

[0145] The lower limit of the circumferential stretch ratio of the bottle is preferably 2 times, more preferably 2.5 times. If it is less than the above ratio, uneven stretching will occur. The upper limit of the circumferential stretch ratio of the bottle body is preferably 6 times, more preferably 5 times, and even more preferably 4 times. If it exceeds the above ratio, breakage is likely to occur.

[0146] When heat setting is performed in the same mold after blow molding, the lower limit of the mold temperature for blow molding is preferably 80°C, more preferably 120°C, further preferably 130°C, and most preferably 140°C. If the temperature is lower than the above, crystallization cannot be sufficiently promoted in the subsequent heat setting, the heat resistance is insufficient, the heat setting time needs to be extended, and the productivity decreases.

[0147] 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; the lower limit of the mold temperature is preferably 280°C, more preferably 290°C, and even more preferably 300°C.

[0148] Because the polyester resin of the present invention has the property that the higher the melting temperature, the lower the melt tension, when the mold temperature is increased, the melt tension decreases when the mold and the polyester resin come into contact, and the occurrence of melt fracture is reduced; on the other hand, after being ejected from the mold, the melt tension increases, and the occurrence of sag is reduced.

[0149] The blow-molded bottle is then heat-set in a mold. The lower limit of the heat-setting time is preferably 0.5 seconds, more preferably 1 second, and even more preferably 1.5 seconds. If the time is less than the above, crystallization cannot be sufficiently promoted, and the heat resistance becomes insufficient. The upper limit of the heat-setting time is preferably 15 seconds, more preferably 10 seconds, and even more preferably 5 seconds. Long heat-setting times not only reduce productivity, but also require a large number of molds in the case of rotary blow molding machines, and the economy deteriorates if the equipment is enlarged. It can be noted that after heat-setting in the mold, further heating and setting can be performed using infrared heaters, hot air, induction heating, etc.

[0150] Alternatively, blow molding can be performed first 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 that of the mold in the above-mentioned case.

[0151] While a blow molding apparatus can be comprised of a single mold, in mass production, it is preferable to have multiple molds that move sequentially between the location where the heated preform is placed on the mold, the stretching location, the heat-setting location, and the bottle discharge location.

[0152] It should be noted that although the above describes the cold preform method for reheating and cooling preforms, the hot preform method for blow molding preforms with incompletely cooled preforms can also be used.

[0153] The volume of the formed bottle is preferably 200ml to 6L, more preferably 300ml to 2L. The shape of the bottle body can be any shape, such as circular, quadrilateral (including shapes with cut-off corners), or hexagonal.

[0154] The polyester resin of the present invention can be blow molded (preferably direct blow molded) and is suitable for containers (e.g. bottles) for cosmetics, detergents, beverages, etc.

[0155] This application claims priority based on Japanese Patent Application No. 2020-207927, filed on December 15, 2020. The entire contents of the description of Japanese Patent Application No. 2020-207927, filed on December 15, 2020, are incorporated herein by reference.

[0156] Example

[0157] The present invention is specifically described based on the embodiments shown below, but the present invention is not limited to the embodiments.

[0158] Determination of intrinsic viscosity IV of polyester resin

[0159] The polyester resin was dissolved in a mixed solvent of p-chlorophenol / tetrachloroethane (3 / 1 by weight), and the viscosity was measured at 30°C using an Orthau viscometer.

[0160] Determination of polyester resin composition

[0161] Using a RUKER-manufactured AVANCE NE0600 Fourier transform NMR device in deuterated chloroform solvent, the following were performed: 1 H-NMR analysis and 13 C-NMR analysis determines the composition of the polyester resin based on the integral ratio.

[0162] Determination of the melting point of polyester resin

[0163] 5 mg of polyester resin was placed in an aluminum sample pan and sealed. The sample was heated to 300 °C using a differential scanning calorimeter (DSC) DSC-Q100 manufactured by TA Instruments Japan at a heating rate of 20 °C / min. The maximum peak temperature of the heat of fusion was determined as the melting point.

[0164] Determination of gel

[0165] 30g of melt-polymerized polyester granules and 300ml of a 3 / 1 (by weight) mixture of p-chlorophenol and tetrachloroethane were added to a round-bottom conical flask equipped with a stirrer. The mixture was stirred for 2 hours at 100–105°C to dissolve the granules in the solution. The solution was cooled to room temperature and filtered using a 47mm diameter, 1.0μm pore size PTFE membrane filter (Advantec, product name: T100A047A) under a pressure of 0.15MPa to separate foreign matter. The effective filtration diameter was 37.5mm. After filtration, the filter was immediately washed with 300ml of chloroform and then dried under reduced pressure at 30°C for 24 hours. The filter surface was observed using an optical microscope, and the undissolved matter (gel) was evaluated according to the following criteria.

[0166] 0:0 gels

[0167] Δ~〇: There are 1 to 4 gels

[0168] Δ: There are 5 to 10 gels

[0169] ×: There are more than 11 gels

[0170] Measurement of melt tension

[0171] During the molding of polyester resin, the following apparatus and conditions are used to determine the melt tension.

[0172] Capillary rheometer (Toyo Seiki Manufacturing Co., Ltd.)

[0173] Temperature: 270℃

[0174] Capillary length: 10mm

[0175] Capillary diameter: 1mm

[0176] Shearing speed: 243s -1

[0177] Maximum traction speed: 200m / min

[0178] Traction start speed: 10m / min

[0179] Or traction speed: 100m / min (constant)

[0180] Traction time: 90s

[0181] Determination of melt viscosity

[0182] The following apparatus and conditions are used to determine the melt viscosity during the molding of polyester resin.

[0183] Capillary rheometer (Toyo Seiki Manufacturing Co., Ltd.)

[0184] Capillary length: 10mm

[0185] Capillary diameter: 1mm

[0186] Temperature: 270℃

[0187] Shearing speed: 30s -1 Or 2000s -1

[0188] Determination of acid value (terminal carboxyl group concentration (unit: eq / ton, expressed as acid value))

[0189] Dissolve 0.5 g of polyester resin in 25 ml of benzyl alcohol, and titrate with a benzyl alcohol solution containing 0.01 mol / L sodium hydroxide. The indicator used is a solution obtained by dissolving 0.10 g of phenolphthalein in a mixture of 50 ml of ethanol and 50 ml of water.

[0190] Determination of the amounts of aluminum, phosphorus, germanium, and titanium atoms in polyester resin

[0191] A sample was prepared by heating polyester resin to its melting point +20°C within a stainless steel circular ring with a thickness of 5 mm and an inner diameter of 50 mm. The elemental amounts were determined by fluorescence X-ray analysis and expressed in ppm. It should be noted that a standard curve previously obtained from samples with known elemental amounts was used to determine the amounts.

[0192] Evaluation of formability (sag), mechanical properties, surface smoothness, and transparency in profile extrusion molding.

[0193] With the barrel temperature set at 270℃, a die lip was installed on a single-screw extruder (L / D = 30, all-helix type, screw diameter 50mm). A sizing die, determining the final size of the extruded profile, was then installed at the front end of the cooling water tank. Polyester resin was formed via the water tank through a profile extrusion molding machine equipped with a traction unit. The sag during molding and the mechanical properties, surface smoothness, and transparency of the molded product were evaluated according to the following criteria. The results are shown in Table 2.

[0194] Evaluation of formability (droop)

[0195] Vertical extension is evaluated based on the following criteria.

[0196] ◎: During molding, the polyester resin did not sag at all and maintained its shape.

[0197] 〇: Slight sagging of polyester resin during molding

[0198] △: Polyester resin sags during molding, making stable mass production impossible.

[0199] ×: During molding, due to the sagging of the polyester resin, the resin cannot pass through the sizing mold from the die lip.

[0200] Evaluation of the mechanical properties (strength) of molded articles

[0201] Polyester resin molded articles are evaluated by bending them 180° according to the following criteria.

[0202] 〇: No cracks

[0203] ×: There is a crack

[0204] Evaluation of surface smoothness

[0205] The surface roughness of the outer surface of polyester resin molded articles was determined using a Sulfcorder Et4000A manufactured by Kosaka Laboratory, and compared with the following benchmarks based on the three-dimensional center surface average roughness (SRa).

[0206] ◎: SRa is less than 0.1μm

[0207] 〇: SRa is above 0.1μm and below 0.15μm

[0208] ×: SRa is above 0.15μm

[0209] Evaluation of transparency

[0210] A 3cm quadrilateral was cut from a polyester resin molded product, measured using a NDH-5000 haze meter manufactured by Nippon Denshoku Kogyo, and evaluated according to the following criteria.

[0211] ◎: HAZE less than 5%

[0212] 〇: HAZE is above 5% and below 10%.

[0213] ×: HAZE is 10% or higher

[0214] Evaluation of heat resistance (thermal oxidative stability parameter (TOD))

[0215] Resin fragments from cryogenically pulverized polyester resin ([IV]) i The powder was prepared to a fineness of less than 20 mesh. The powder was vacuum-dried at 130°C for 12 hours. 300 mg of the powder was then 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. Next, a drying tube containing silica gel was attached to the top of the test tube, and the [IV] value was measured under dry air after immersion in a nitrate bath at 230°C for 15 minutes. f1 The TOD is calculated as follows. However, [IV] i and [IV] f1These refer to IV (dL / g) before and after the heating test, respectively. Cryo-pulverization was performed using a cryo-pulverizer (SPEX Corporation, Model 6750, USA). Approximately 2g of resin fragments and a dedicated impactor were placed in a dedicated unit, which was then placed in the apparatus. Liquid nitrogen was added to the apparatus and maintained for approximately 10 minutes. Then, pulverization was performed for 5 minutes using RATE 10 (the impactor reciprocated approximately 20 times per second).

[0216] TOD = 0.245{[IV] f1 -1.47 -[IV] i -1.47}

[0217] The lower the TOD value of polyester resin, the higher its heat resistance.

[0218] Evaluation of CT4 content

[0219] 50 mg of polyester resin was dissolved in 1 ml of a hexafluoroisopropanol / chloroform mixture (volume ratio = 1 / 9), and further diluted with 4 ml of chloroform. Then, 10 ml of methanol was added to precipitate the polyester resin, followed by centrifugation. The supernatant was concentrated, dried, and dissolved again in 0.4 ml of dimethylformamide. The CT4 content was determined by high-performance liquid chromatography (HPLC).

[0220] Device: Waters ACQUITY UPLC

[0221] Chromatographic column: Waters BEH-C18 2.1×150mm (manufactured by Waters)

[0222] Transparency evaluation during continuous forming

[0223] Dry polyester resin was fed into a sheet extruder with a die and continuously extruded at 280°C for 2 days to produce sheets approximately 0.5 mm thick. The contamination at the die exit and the condition of the sheet surface were visually evaluated according to the following criteria.

[0224] (Evaluation Criteria)

[0225] ◎: There are almost no contaminants adhering to the mold exit, and the sheet surface is in good condition.

[0226] 〇: Slight contaminants adhered to the mold exit, but the sheet surface was in good condition.

[0227] △: A small amount of contaminants are attached to the mold exit, and a small amount of foreign matter is attached to the surface of the sheet.

[0228] ×: The mold outlet is heavily contaminated with pollutants; there are many deposits on the sheet surface.

[0229] Synthetic Examples 1-6 (Preparation of the compound (branching agent) represented by Formula (I))

[0230] Referring to Patent Documents 1-3, U.S. Patent Application No. 09 / 354350, and U.S. Patent Application No. 09 / 614402, compounds represented by formula (I) were prepared in a 2-gallon free radical continuous polymerization reactor system. The composition and weight-average molecular weight of the compounds represented by formula (I) obtained by Synthesies 1-6 are shown in Table 1 below.

[0231] To clarify, the weight-average molecular weight of the compound represented by formula (I) is calculated using GPC based on standard polyethylene. Specifically, 4 mg of the sample of the compound represented by formula (I) is weighed and dissolved in 4 ml of a mixed solvent of chloroform and isofluoroisopropanol (60 / 40 vol%). The solution is filtered through a 0.2 μm membrane filter, and the resulting sample solution is provided to GPC for conversion to standard polystyrene to determine the weight-average molecular weight.

[0232] In addition, according to 1 H-NMR and 13 C-NMR was used to determine the l, m, and n of the compound represented by formula (I).

[0233] That is, l, m, and n are taken as the average number, rounded to one decimal place and expressed as an integer. Specifically, the sample of the compound represented by formula (I) is... 1 For H-NMR, it was dissolved in a mixed solvent of deuterated chloroform / trifluoroacetic acid (volume ratio 85 / 15); 13 For C-NMR, the sample was dissolved in deuterated chloroform or a mixture of deuterated chloroform and hexafluoroisopropanol (volume ratio 1 / 1), and then subjected to Fourier transform NMR using a BRUKER AVANCE NE0600 instrument with 50–200 scans. 1 H-NMR) and 10,000 times ( 13 The measurements were performed at room temperature under the conditions of C-NMR. 1 H-NMR and 13 The ratios of each component and the proportion of the component at the end can be calculated from the C-NMR spectrum, and l, m, and n can be determined.

[0234] In addition, the compound represented by formula (I) used in the synthesis example has the following methacrylic acid monomer structural unit (hereinafter referred to as DEMA structural unit) (* represents the atomic bonding with other monomer structural units (e.g., styrene structural unit, methyl methacrylate structural unit)). For example, the compound containing this DEMA structural unit can be obtained by methods such as a method of synthesizing by subjecting glycidyl methacrylate to a ring-opening reaction using water. According to Patent Documents 1 to 3, U.S. Patent Application No. 09 / 354350, and U.S. Patent Application No. 09 / 614402, after synthesizing a copolymer of styrene and glycidyl methacrylate (and further methyl methacrylate as needed), the compound represented by formula (I) can be obtained by a method such as subjecting it to ring-opening synthesis using water.

[0235] <DEMA structural unit>

[0236] [Chemical Formula 5]

[0237]

[0238] The following abbreviations are used hereinafter: STY = styrene structural unit, MMA = methyl methacrylate structural unit, DEMA structural unit (the methacrylic acid monomer structural unit of the above chemical formula).

[0239] [Table 1]

[0240]

[0241] Example 1

[0242] Put 2593 g of terephthalic acid (manufactured by Mitsui Chemicals), 1937 g of ethylene glycol (manufactured by Nippon Catalyst), and 4 g of triethylamine (manufactured by Nacalai Tesque) into a 10 L pressure vessel equipped with a stirrer, a thermometer, and an effluent cooler, and carry out esterification at 240 °C for 3.0 hours under a pressure of 0.35 MPa. With respect to 100% by weight of the alcohol component of the obtained polyester resin, while controlling the flow rate and adding continuously in stages, the reaction was carried out so that the compound represented by formula (I) obtained in Synthesis Example 1 was 0.2% by weight.

[0243] As a polycondensation catalyst, 30 ppm of aluminum acetate (based on aluminum atoms (Al) and 72 ppm of Irgamod 295 (manufactured by BASF) were added relative to the mass of the polyester resin. Then, 1 ppm of Solvent Blue 45 (manufactured by Clariant) was added relative to the polyester resin. The mixture was stirred at 260°C for 5 minutes under a nitrogen atmosphere and atmospheric pressure. Afterward, the temperature was increased to 280°C over 60 minutes, while the pressure of the reaction system was slowly reduced to 13.3 Pa (0.1 Torr). Polycondensation was then carried out at 280°C and 13.3 Pa. The pressure was restored to atmospheric pressure under nitrogen, and the slightly pressurized resin was expelled in a thin stream into cold water for rapid cooling. After holding in the cold water for 20 seconds, the resin was cut into cylindrical polyester particles approximately 3 mm in length and 2 mm in diameter.

[0244] The polyester resin particles obtained from melt polymerization were dried under reduced pressure (below 13.3 Pa, 80°C, 12 hours), followed by crystallization treatment (below 13.3 Pa, 130°C, 3 hours; further, below 13.3 Pa, 160°C, 3 hours). The cooled polyester resin particles were then placed in a solid-state polymerization reactor, and solid-state polymerization was carried out while maintaining the system pressure below 13.3 Pa and the temperature at 200–220°C to obtain polyester particles with an intrinsic viscosity (IV) of 1.18 dl / g, an acid value (AV) of 15 eq / ton, and a total oxygen demand (TOD) of 0.015.

[0245] Example 2

[0246] In Example 1, the amount of compound represented by formula (I) obtained in Synthesis Example 1 was changed to 0.001% by weight, and polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with intrinsic viscosity IV of 1.17 dl / g, acid value AV of 20 eq / ton, and TOD of 0.015.

[0247] Example 3

[0248] In Example 1, the amount of the compound represented by formula (I) obtained in Synthesis Example 1 was changed to 3.0% by weight, and polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 1.20 dl / g, an acid value AV of 20 eq / ton, and a TOD of 0.010.

[0249] Example 4

[0250] 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 its addition amount was changed to 0.2% by weight. Polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 1.20 dl / g, an acid value AV of 18 eq / ton, and a TOD of 0.015.

[0251] Example 5

[0252] 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 its addition amount was changed to 0.2% by weight. Polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 1.15 dl / g, an acid value AV of 19 eq / ton, and a TOD of 0.015.

[0253] Example 6

[0254] 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 the amount added was changed to 0.2% by weight. Polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 1.14 dl / g, an acid value AV of 17 eq / ton, and a TOD of 0.015.

[0255] Example 7

[0256] 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, and the amount added was changed to 0.2% by weight. Polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 1.09 dl / g, an acid value AV of 20 eq / ton, and a TOD of 0.015.

[0257] Example 8

[0258] 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 its addition amount was changed to 0.2% by weight. Polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 1.08 dl / g, an acid value AV of 19 eq / ton, and a TOD of 0.015.

[0259] Example 9

[0260] 2593 g of terephthalic acid (Mitsui Chemicals), 1257 g of ethylene glycol (Japan Catalyst), and 4 g of triethylamine (Nacalai Tesque) were placed into a 10 L pressure vessel equipped with a stirrer, thermometer, and outflow cooler. Esterification was carried out at 240 °C for 1.5 hours under a pressure of 0.35 MPa. The alcohol content was 100% by weight relative to the obtained polyester resin. The reaction was carried out in stages by continuously adding the alcohol while controlling the flow rate, so that the compound represented by formula (I) obtained in Synthesis Example 1 was 0.2% by weight.

[0261] As a polycondensation catalyst, 30 ppm of aluminum acetate (based on aluminum atoms (Al) and 72 ppm of Irgamod 295 (manufactured by BASF) were added relative to the mass of the polyester resin. Then, 1 ppm of Solvent Blue 45 (manufactured by Clariant) was added relative to the polyester resin. The mixture was stirred at 260°C for 5 minutes under a nitrogen atmosphere and atmospheric pressure. Afterward, the temperature was increased to 280°C over 60 minutes, while the pressure of the reaction system was slowly reduced to 13.3 Pa (0.1 Torr). Polycondensation was then carried out at 280°C and 13.3 Pa. The pressure was restored to atmospheric pressure under nitrogen, and the slightly pressurized resin was expelled in a thin stream into cold water for rapid cooling. After holding in the cold water for 20 seconds, the resin was cut into cylindrical polyester particles approximately 3 mm in length and 2 mm in diameter.

[0262] The polyester granules obtained from melt polymerization were dried under reduced pressure (below 13.3 Pa, 80°C, 12 hours), followed by crystallization treatment (below 13.3 Pa, 130°C, 3 hours; further, below 13.3 Pa, 160°C, 3 hours). The cooled polyester resin granules were then placed in a solid-state polymerization reactor, and solid-state polymerization was carried out while maintaining the system pressure below 13.3 Pa and the temperature between 200°C and 220°C, to obtain polyester granules with an intrinsic viscosity (IV) of 1.18 dl / g, an acid value (AV) of 45 eq / ton, and a total oxygen demand (TOD) of 0.020.

[0263] Example 10

[0264] 2593 g of terephthalic acid (Mitsui Chemicals), 976 g of ethylene glycol (Japan Catalyst), and 4 g of triethylamine (Nacalai Tesque) were placed into a 10 L pressure vessel equipped with a stirrer, thermometer, and outflow cooler. Esterification was carried out at 240 °C for 1 hour under a pressure of 0.35 MPa. The alcohol content of the resulting polyester resin was 100% by weight, and the reaction was carried out in stages by continuously adding the alcohol while controlling the flow rate, so that the compound represented by formula (I) obtained in Synthesis Example 1 was 0.2% by weight.

[0265] As a polycondensation catalyst, 30 ppm of aluminum acetate (based on aluminum atoms (Al) and 72 ppm of Irgamod 295 (manufactured by BASF) were added relative to the mass of the polyester resin. Then, 1 ppm of Solvent Blue 45 (manufactured by Clariant) was added relative to the polyester resin. The mixture was stirred at 260°C for 5 minutes under a nitrogen atmosphere and atmospheric pressure. Afterward, the temperature was increased to 280°C over 60 minutes, while the pressure of the reaction system was slowly reduced to 13.3 Pa (0.1 Torr). Polycondensation was then carried out at 280°C and 13.3 Pa. The pressure was restored to atmospheric pressure under nitrogen, and the slightly pressurized resin was expelled in a thin stream into cold water for rapid cooling. After holding in the cold water for 20 seconds, the resin was cut into cylindrical polyester particles approximately 3 mm in length and 2 mm in diameter.

[0266] The polyester resin particles obtained from melt polymerization were dried under reduced pressure (below 13.3 Pa, 80°C, 12 hours), followed by crystallization treatment (below 13.3 Pa, 130°C, 3 hours; further, below 13.3 Pa, 160°C, 3 hours). The cooled polyester resin particles were then placed in a solid-state polymerization reactor, and solid-state polymerization was carried out while maintaining the system pressure below 13.3 Pa and the temperature between 200°C and 220°C, to obtain polyester particles with an intrinsic viscosity (IV) of 1.05 dl / g, an acid value (AV) of 110 eq / ton, and a total oxygen demand (TOD) of 0.025.

[0267] Example 11

[0268] 2593 g of terephthalic acid (Mitsui Chemicals), 1937 g of ethylene glycol (Nippon Catalyst), and 4 g of triethylamine (Nacalai Tesque) were placed into a 10 L pressure vessel equipped with a stirrer, thermometer, and outflow cooler. Esterification was carried out at 240 °C for 1.5–3.0 hours under a pressure of 0.35 MPa. The alcohol content was 100% by weight relative to the obtained polyester resin, and the reaction was carried out in stages by continuously adding the alcohol while controlling the flow rate, so that the compound represented by formula (I) obtained in Synthesis Example 1 was 0.2% by weight.

[0269] To the extent that the polyester resin was subjected to polycondensation, 100 ppm of germanium dioxide (based on germanium atoms (Ge) and 100 ppm of triethyl phosphate (based on phosphorus atoms (P)) were added as a polycondensation catalyst. Then, 1 ppm of Solvent Blue 45 (Clariant) was added to the polyester resin. The mixture was stirred at 260°C for 5 minutes under a nitrogen atmosphere and atmospheric pressure. Afterward, the temperature was increased to 280°C over 60 minutes, while the pressure of the reaction system was slowly reduced to 13.3 Pa (0.1 Torr). Polycondensation was then carried out at 280°C and 13.3 Pa. The pressure was restored to atmospheric pressure under nitrogen, and the slightly pressurized resin was expelled in a thin stream into cold water for rapid cooling. After holding in the cold water for 20 seconds, the resin was cut into cylindrical polyester particles approximately 3 mm in length and 2 mm in diameter.

[0270] The polyester resin particles obtained from melt polymerization were dried under reduced pressure (below 13.3 Pa, 80°C, 12 hours), followed by crystallization treatment (below 13.3 Pa, 130°C, 3 hours; further, below 13.3 Pa, 160°C, 3 hours). The cooled polyester particles were then placed in a solid-state polymerization reactor, and solid-state polymerization was carried out while maintaining the system pressure below 13.3 Pa and the temperature between 200°C and 220°C, to obtain polyester particles with an intrinsic viscosity (IV) of 1.18 dl / g, an acid value (AV) of 30 eq / ton, and a total oxygen demand (TOD) of 0.330.

[0271] Example 12

[0272] 2593 g of terephthalic acid (Mitsui Chemicals), 1937 g of ethylene glycol (Nippon Catalyst), and 4 g of triethylamine (Nacalai Tesque) were placed into a 10 L pressure vessel equipped with a stirrer, thermometer, and outflow cooler. Esterification was carried out at 240 °C for 1.5–3.0 hours under a pressure of 0.35 MPa. The alcohol content was 100% by weight relative to the obtained polyester resin, and the reaction was carried out in stages by continuously adding the alcohol while controlling the flow rate, so that the compound represented by formula (I) obtained in Synthesis Example 1 was 0.2% by weight.

[0273] Relative to the mass of the polyester resin, 10 ppm of tetrabutyltitanium (Ti) and 100 ppm of triethyl phosphate (P) were added. Then, 2 ppm of Solvent Blue 45 (Clariant) was added relative to the polyester resin. The mixture was stirred at 260°C for 5 minutes under a nitrogen atmosphere and atmospheric pressure. Afterward, the temperature was increased to 280°C over 60 minutes, while the pressure of the reaction system was slowly reduced to 13.3 Pa (0.1 Torr). Polycondensation was then carried out at 280°C and 13.3 Pa. The pressure was restored to atmospheric pressure under nitrogen, and the slightly pressurized resin was expelled in a thin stream into cold water for rapid cooling. After holding in the cold water for 20 seconds, the resin was cut into cylindrical polyester particles approximately 3 mm in length and 2 mm in diameter.

[0274] The polyester granules obtained from melt polymerization were dried under reduced pressure (below 13.3 Pa, 80°C, 12 hours), followed by crystallization treatment (below 13.3 Pa, 130°C, 3 hours; further, below 13.3 Pa, 160°C, 3 hours). The cooled polyester granules were then placed in a solid-state polymerization reactor, and solid-state polymerization was carried out while maintaining the system pressure below 13.3 Pa and the temperature between 200°C and 220°C, to obtain polyester granules with an intrinsic viscosity (IV) of 1.18 dl / g, an acid value (AV) of 31 eq / ton, and a total oxygen demand (TOD) of 0.360.

[0275] Comparative Example 1

[0276] Without adding the compound represented by formula (I), germanium dioxide at 100 ppm (Ge atoms) and triethyl phosphate at 30 ppm (P atoms) were added as a polycondensation catalyst relative to the mass of the polyester resin. Otherwise, polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 1.19 dl / g, an acid value AV of 15 eq / ton, and a TOD of 0.400.

[0277] Comparative Example 2

[0278] The amount of compound represented by formula (I) obtained in Synthesis Example 1 was changed to 0.0001% by weight, relative to the mass of polyester resin. As a polycondensation catalyst, 100 ppm of germanium dioxide (Ge atoms) and 30 ppm of triethyl phosphate (P atoms) were added. Otherwise, polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 1.22 dl / g, an acid value AV of 17 eq / ton, and a TOD of 0.400.

[0279] Comparative Example 3

[0280] The amount of the compound represented by formula (I) obtained in Synthesis Example 1 was changed to 6% by weight, relative to the mass of the polyester resin. As a polycondensation catalyst, 100 ppm of germanium dioxide (Ge atoms) and 30 ppm of triethyl phosphate (P atoms) were added. Otherwise, polymerization was carried out under the same conditions as in Example 1 to obtain polyester particles with an intrinsic viscosity IV of 0.71 dl / g, an acid value AV of 16 eq / ton, and a TOD of 0.400.

[0281]

[0282] In addition, in Examples 1 to 12, the temperature was 270°C and the shearing rate was 30 seconds. -1 At a melt viscosity of 26000 dPa·s or higher, at a temperature of 270℃ and a shear rate of 2000 s⁻¹, the melt viscosity is above 26000 dPa·s. -1 Below that, the melt viscosity is below 6500 dPa·s.

[0283] Industrial utilization potential

[0284] The polyester resin of this invention can improve formability and maintain transparency in extrusion molding, profile extrusion molding, direct blow molding, blow molding, injection blow molding, and calendering processes that require high melt tension, and is expected to make a significant contribution to the industry.

Claims

1. A polyester resin, characterized in that, As a component of polyester, it contains dicarboxylic acid and alcohol components. In 100% by weight of the alcohol component, the content of the compound represented by formula (I) is 0.001–4.5% by weight. The 100 mol% dicarboxylic acid component contains 85-100 mol% terephthalic acid, and as an alcohol component, it contains ethylene glycol. [Chemical Formula 1] In the formula, m and n are each from 1 to 1000, l represents 0 to 1000, and R 1 R represents an aromatic hydrocarbon group with 6 to 20 carbon atoms. 2 R 3 R 4 Each is represented as either a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

2. The polyester resin according to claim 1, characterized in that, The weight-average molecular weight of the compound represented by formula (I) is above 200 and below 500,000.

3. The polyester resin according to claim 1 or 2, characterized in that, The content of cyclic oligomer tetramers in the polyester resin is less than 2680 ppm.

4. The polyester resin according to claim 1 or 2, characterized in that, At a temperature of 270℃, a traction speed of 100m / min, and a shearing speed of 243s... -1 The lower melt tension is above 15mN.

5. The polyester resin according to claim 1 or 2, characterized in that, At a temperature of 270℃ and a shear rate of 30s -1 The melt viscosity is above 26000 dPa·s; at a temperature of 270℃ and a shear rate of 2000 s⁻¹. -1 The melt viscosity is below 6500 dPa·s.

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