WO2023032920A1

WO2023032920A1 - Polyester resin

Info

Publication number: WO2023032920A1
Application number: PCT/JP2022/032421
Authority: WO
Inventors: 秀和吉田; 洋祐畑中; 広朗福島; 耕輔魚谷; 浩尚佐々木; 英人大橋; 文章西中; 惠一朗戸川
Original assignee: 東洋紡株式会社
Priority date: 2021-08-31
Filing date: 2022-08-29
Publication date: 2023-03-09
Also published as: TW202323364A; JPWO2023032920A1

Abstract

The purpose of the present invention is to provide a polyester resin or the like that has excellent gelling suppression, moldability, surface smoothness, transparency, mechanical properties, heat resistance, and thermal oxidation resistance stability.　The present invention relates to a polyester resin that is characterized by having, as constituent components thereof, terephthalic acid as a dicarboxylic acid component, and ethylene glycol, a bisphenol A-ethylene oxide adduct, and a compound represented by a specific structure as alcohol components, wherein the terephthalic acid is 85-100 mol% of the dicarboxylic acid component or components, the proportion of ethylene glycol is 85-98 mol% whereas that of the bisphenol A-ethylene oxide adduct is 2-15 mol%, and the compound represented by the specific structure is 0.001-5 mass% within 100 mass% of the alcohol components. (In the formula, m and n each represent 1-1000, l represents 0-1000, R1 represents a C6-20 aromatic hydrocarbon group, and R2, R3, and R4 each represent a hydrogen atom or a C1-10 alkyl group.)

Description

polyester resin

The present invention relates to a polyester resin that provides molded articles with excellent moldability, transparency, mechanical properties, heat resistance, and thermal oxidation stability. Specifically, the present invention provides improved moldability in extrusion molding, profile extrusion molding, direct blow molding, inflation molding, injection blow molding, and calendering molding that require high melt tension, as well as transparency and mechanical properties. , relates to a polyester resin that achieves improved heat and oxidation stability.

In recent years, for example, there is a tendency to replace vinyl chloride resin with other materials due to the problem of environmental impact. considered as a material.

Among polyester resins, for example, crystalline polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN) are used for heat-resistant parts by injection molding, films, sheets, and the like by extrusion molding. Blow-molded beverage bottles, melt-spun fibers, etc. are also used in various melt-molded products.

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 remarkable, preforms or molded products sag, unevenness in the thickness of the molded product, and large burrs. Therefore, there was a problem that the good product rate and the stability of continuous production decreased.

On the other hand, in order to solve the problem of such a drawdown phenomenon, an invention has been disclosed in which a branching structure (branching agent) is introduced into the resin skeleton to improve moldability in direct blow molding, which requires high melt tension. (For example, Patent Documents 1 to 3).

Japanese Patent No. 5931061 Japanese Patent No. 5941843 JP 2016-56384 A

However, in the techniques of Patent Documents 1 to 3, the reactivity between the branched structures (branching agents) is high, and gelation occurs even when mixed with a carboxylic acid compound and reacted with the constituent components of the polyester resin. There is a problem that the solubility with the constituent components is lowered, and the resulting polyester resin molded article cannot have good surface smoothness.
In addition, although the drawdown phenomenon is improved in Patent Documents 1 to 3, the surface smoothness of the molded product is reduced due to the occurrence of melt fracture when the resin is discharged from the die during molding due to the excessively high melt tension. However, there is also a problem that the transparency of the molded product is lowered. In addition, polyester resin molded articles are required to have heat resistance and the like.

The present invention was made against the background of such problems of the prior art, and an object of the present invention is to improve gelation suppression, moldability, surface smoothness, transparency, mechanical properties, heat resistance, and heat-oxidation stability. An object of the present invention is to provide a polyester resin that gives excellent molded articles.

More specifically, the present invention is excellent in gelation suppression, surface smoothness, transparency, mechanical properties, heat resistance, and thermal oxidation stability, and can be used in extrusion molding, profile extrusion molding, and direct molding, which require high melt tension. To provide a polyester resin which gives a molded product excellent in moldability in blow molding, inflation molding, injection blow molding and calendering molding.

As a result of diligent studies, the present inventors have found that the above problems can be solved by the means shown below, and have arrived at the present invention. That is, the present invention has the following configurations.

[1] Constituting terephthalic acid as a dicarboxylic acid component, ethylene glycol, a bisphenol A-ethylene oxide adduct as an alcohol component, and a compound represented by the following formula (I), and 85 to 85% of terephthalic acid in the dicarboxylic acid component. 100 mol%, and the ratio of 2 to 15 mol% of bisphenol A-ethylene oxide adduct to 85 to 98 mol% of ethylene glycol, and the compound represented by the following formula (I) is 0 in 100% by mass of the alcohol component. .001 to 5% by weight of a polyester resin.

(wherein m and n are each an integer of 1 to 1000, l is an integer of 0 to 1000, R ¹ represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, R ² , R ³ , Each R ⁴ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)
[2] The polyester resin according to [1], wherein the weight average molecular weight of the compound represented by formula (I) is 200 or more and 500,000 or less.
[3] The polyester resin according to any one of [1] or [2], which has a melt tension of 15 mN or more at a temperature of 270°C, a take-up speed of 100 m/min, and a shear rate of 243 s ^-1 .
[4] Any one of [1] to [3] having a melt viscosity of 26000 dPa s or more at a temperature of 270° C. and a shear rate of 30 s ⁻¹ or 6500 dPa s or less at a temperature of 270° ^C. and a shear rate of 2000 s −1 The polyester resin described in .

ADVANTAGE OF THE INVENTION According to this invention, the molded article of the polyester resin excellent in gelatinization suppression, moldability, surface smoothness, transparency, mechanical property, heat resistance, and heat-oxidation stability is obtained.
In particular, the moldability is excellent in extrusion molding, profile extrusion molding, direct blow molding, inflation molding, injection blow molding, and calendering molding, which require higher melt tension than conventional molding.

1. Polyester Resin The polyester resin of the present invention comprises terephthalic acid as a dicarboxylic acid component, ethylene glycol as an alcohol component, a bisphenol A-ethylene oxide adduct, and a compound represented by the following formula (I), and terephthalic acid is a dicarboxylic acid. In the acid component, it is 85 to 100 mol%, and the ratio is 2 to 15 mol% of the bisphenol A-ethylene oxide adduct with respect to 85 to 98 mol% of ethylene glycol, and the compound represented by the following formula (I) is an alcohol component. It is 0.001 to 5% by mass in 100% by mass.

(wherein m and n are each an integer of 1 to 1000, l is an integer of 0 to 1000, R ¹ represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, R ² , R ³ , Each R ⁴ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)

The polyester resin of the present invention contains a polymer of a predetermined dicarboxylic acid component and an alcohol component, and is characterized by containing a predetermined amount of the compound represented by the formula (I) as the alcohol component.
In the present invention, the compound represented by formula (I) is a branching agent for polyester resins, and is used together with a commonly used diol component.
Further, the compound represented by the formula (I) has two or more functional groups (hydroxyl groups) per molecule that can react with the carboxyl groups of the dicarboxylic acid component, and the polyester resin has a partially branched structure as a whole. can be introduced into

As described above, since the polyester resin of the present invention uses the compound represented by formula (I), it is possible to suppress gelation, and during melt extrusion, the melt tension decreases as the temperature increases. In addition, since the melt viscosity decreases under high shear, melt fracture does not occur during molding, and it is excellent in moldability, surface smoothness, transparency, mechanical properties, heat resistance, and thermal oxidation stability. Become.

The compounds represented by formula (I) are as follows.

R ¹ represents an aromatic hydrocarbon group having 6 to 20 carbon atoms.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R ¹ 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 group, 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, fluorenyl group and the like.

The number of carbon atoms in the aromatic hydrocarbon group is preferably 6-18, more preferably 6-15, still more preferably 6-12.

Among them, the aromatic hydrocarbon group is particularly preferably a phenyl group, an o-tolyl group, an m-tolyl group, or a p-tolyl group, most preferably a phenyl group.

R ² , R ³ and R ⁴ represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

Examples of alkyl groups having 1 to 10 carbon atoms represented by R ² , R ³ and R ⁴ include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, a linear alkyl group such as a decyl group;
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-ethyl propyl 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-methylhexyl 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-propyl branched chain alkyl groups such as hexyl 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, 2,6- dimethylcyclohexyl group, 3,4-dimethylcyclohexyl group, 3,5-dimethylcyclohexyl group, 2,2-dimethylcyclohexyl group, 3,3-dimethylcyclohexyl group, 4,4-dimethylcyclohexyl group, cyclooctyl group, 2, Cycloalkyl groups such as a 4,6-trimethylcyclohexyl group, a 2,2,6,6-tetramethylcyclohexyl group, and a 3,3,5,5-tetramethylcyclohexyl group are included.

The number of carbon atoms in the alkyl group is preferably 1-8, more preferably 1-6, and still more preferably 1-4.

Among them, the alkyl group is particularly preferably a methyl group, an ethyl group, a propyl group, or a butyl group, most preferably a methyl group.

R ² and R ³ are preferably C 1-10 alkyl groups, and R ⁴ is preferably a hydrogen atom.

The above l, m, and n are the ratios of the following copolymer components (L), (M), and (N) contained in one molecule, and the average number of each component contained in one molecule is Below is a value (ratio) expressed as an integer by rounding off to the nearest digit. The ratio and average number of each component contained in one molecule were obtained from ¹ H-NMR analysis and ¹³ C-NMR analysis.

Each of m and n, which may be the same or different, represents an integer of 1-1000, preferably an integer of 2-800, more preferably an integer of 5-600, still more preferably an integer of 10-400.
l is an integer of 0-1000, preferably an integer of 1-700, more preferably an integer of 2-400, and still more preferably an integer of 5-100.

Even if the compound represented by formula (I) is a random copolymer obtained by randomly copolymerizing the copolymer components (L), (M), and (N), the copolymer components (L), ( A block copolymer in which at least one component of M) and (N) is a block may be used, 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.

Compounds of formula (I) can be prepared in two gallons of free-radical continuous water, see, for example, US Pat. It is possible to prepare in a conventional polymerization reactor system.

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 0.005 to 5% by mass, in 100% by mass of the alcohol component, which is a constituent component of the polyester resin. is 0.01 to 4.5% by mass, more preferably 4% by mass or less, particularly preferably 3.5% by mass or less.
If the content of the compound represented by formula (I) is less than 0.001% by mass, drawdown will occur during molding, and the molding will not be stable, or even if it can be molded, the molded product will tend to have uneven thickness. be. On the other hand, when the content of the compound represented by the formula (I) exceeds 5% by mass, gelation occurs, melt fracture occurs during molding, surface smoothness becomes poor, and a devitrified molded product is obtained. . In addition, there is a tendency for the molded article to contain gel and to be of low quality.

The compound represented by formula (I) may have a predetermined weight average molecular weight, and the weight average molecular weight of the compound represented by formula (I) is preferably 200 or more and 500,000 or less, more preferably It is 500 or more, more preferably 700 or more, still more preferably 1000 or more, more preferably 300,000 or less, still more preferably 100,000 or less, and even more preferably 50,000 or less.
If the weight average molecular weight of the compound represented by formula (I) is less than 200, the unreacted compound may bleed out onto the surface of the molded product, contaminating the surface of the molded product. On the other hand, when the weight-average molecular weight of the compound represented by formula (I) exceeds 500,000, the compatibility between the compound and the polyester deteriorates when the molded article made of the polyester resin is bent, causing voids and whitening. There is fear.
The weight average molecular weight can be determined, for example, by GPC in terms of standard polystyrene.
Specifically, the weight average molecular weight is 0.2 μm after weighing 4 mg of a sample of the compound represented by formula (I) and dissolving it in 4 ml of a mixed solvent of chloroform and isofluoroisopropanol (60/40% by volume). It can be obtained by filtering with a membrane filter, subjecting the obtained sample solution to GPC, and converting to standard polystyrene.

The dicarboxylic acid component and alcohol component used in the present invention are as follows.

Dicarboxylic acid components include 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. Saturated aliphatic dicarboxylic acids exemplified in or ester-forming derivatives thereof (e.g., alkyl esters having 1 to 20 carbon atoms), fumaric acid, maleic acid, unsaturated aliphatics exemplified by itaconic acid, etc. Dicarboxylic acids or ester-forming derivatives thereof (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 Aromatic dicarboxylic acids exemplified by '-biphenylsulfonedicarboxylic acid, 4,4'-biphenyletherdicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p'-dicarboxylic acid, pamoic acid, anthracenedicarboxylic acid, etc. and ester-forming derivatives thereof (for example, alkyl esters having 1 to 20 carbon atoms, preferably dimethyl terephthalate).

Of these dicarboxylic acid components, isophthalic acid, terephthalic acid and naphthalenedicarboxylic acid are preferred, and terephthalic acid is particularly preferred in terms of the physical properties of the resulting polyester resin.

In addition to the above dicarboxylic acids, tri- or tetravalent carboxylic acids may be used in small amounts.
Examples of the carboxylic acid include ethanoic acid, tricarboxylic acid, propanetricarboxylic acid, butanetetracarboxylic acid, pyromellitic acid, trimellitic acid, trimesic acid, 3,4,3′,4′-biphenyltetracarboxylic acid, and esters thereof. forming derivatives (for example, alkyl esters having 1 to 20 carbon atoms) and the like.

The alcohol component other than the compound represented by formula (I) is preferably a diol component. In 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, still more preferably 99.99 to 95.5% by mass, and still more It is preferably 96% by mass or more, particularly preferably 96.5% by mass or more.
The diol component contains ethylene glycol and bisphenol A-ethylene oxide adduct (hereinafter referred to as bisphenol A-EO adduct).
Diols that may be used other than ethylene glycol and bisphenol A-EO adducts 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, 1,4-butylene glycol, 1,5-pentanediol, neopentyl glycol, 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 exemplified by fluorenediol, 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 F, bisphenol S, bisphenol C, 2,5-naphthalenediol, glycols obtained by adding ethylene oxide to these glycols, and products obtained by adding water to bisphenols A, F, S, and C. aromatic glycols.

In addition to the above diol components, tri- or tetrahydric alcohols, hydroxycarboxylic acids, cyclic esters, etc. may be used as diol components.

Examples of the alcohol include trimethylolmethane, trimethylolethane, trimethylolpropane, pentaerythritol, glycerol, and hexanetriol.

The 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) and the like can be mentioned.

Cyclic esters include ε-caprolactone, β-propiolactone, β-methyl-β-propiolactone, δ-valerolactone, glycolide, lactide and the like.

The polyester resin of the present invention contains 85 to 100 mol% of terephthalic acid in 100 mol% of the dicarboxylic acid component, and 87 to 100 mol% of the total of ethylene glycol and bisphenol A-EO adduct in 100 mol% of the diol component. preferable.
Terephthalic acid is contained in 100 mol% of the dicarboxylic acid component, more preferably 90 to 100 mol%, more preferably 95 to 100 mol%, and the total of ethylene glycol and bisphenol A-EO adduct is in 100 mol% of the diol component. , more preferably 90 to 100 mol %, more preferably 95 to 100 mol %.
The ratio of ethylene glycol to bisphenol A-EO adduct is 85-98 mol % of ethylene glycol and 2-15 mol % of bisphenol A-EO adduct. It may be considered that 85 to 98 mol % of ethylene glycol and 2 to 15 mol % of bisphenol A-EO adduct are contained in 100 mol % of the diol component. It is preferable that the bisphenol A-EO adduct is 3 to 13 mol% with respect to 87 to 97 mol% of ethylene glycol, and the bisphenol A-EO adduct is 4 to 11 mol% with respect to 89 to 96 mol% of ethylene glycol. is more preferable. If the bisphenol A-EO adduct is less than 2 mol %, the transparency tends to decrease. Further, when the bisphenol A-EO adduct exceeds 15 mol %, the thermal oxidation stability, heat resistance and moldability tend to deteriorate.
The polyester resin of the present invention is preferably a copolymerized polyethylene terephthalate resin.

The polyester resin of the present invention is a crystalline polyester resin and has a branched structure, and can improve processability such as moldability due to the "melt strength enhancement effect" of increasing molecular weight, and can adjust melt viscosity and melt tension. , the whitening resistance on bending of the molded product and the bleeding out of unreacted substances to the surface layer of the molded product can be suppressed.
If the content of terephthalic acid and ethylene glycol is out of the above range, the polyester resin becomes amorphous and the viscosity cannot be increased by solid-phase polymerization, and there is a possibility that a molded article having high mechanical properties cannot be obtained.

The polyester resin of the present invention may have a given 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, still 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 mixed solvent of parachlorophenol/tetrachloroethane (3/1: weight ratio).

The acid value (AV) of the polyester resin used in the present invention is preferably 100 eq/10 ⁶ g (ton) or less, more preferably 60 eq/10 ⁶ g or less, still more preferably 50 eq/10 ⁶ g or less. On the other hand, the lower the lower limit, the more preferable, and the closer to 0 eq/10 ⁶ g the more preferable. When the acid value exceeds 100 eq/10 ⁶ g, gel tends to occur and the surface properties and haze tend to deteriorate.
The acid value can be obtained by dissolving a polyester resin sample in an alcohol and/or ether solution and titrating with an alcoholic sodium hydroxide solution or an alcoholic potassium hydroxide solution using a phenolphthalein reagent as an indicator. can. A specific method for measuring the acid value is as shown in Examples.

The polyester resin of the present invention may have a predetermined melting point, and the melting point of the polyester resin is preferably 190 to 300°C, more preferably 195 to 280°C, still more preferably 210 to 260°C, still more preferably. is above 220°C.
The melting point can be measured with a differential scanning calorimeter (DSC) at a heating rate of 20° C./min up to 310° C., and the maximum peak temperature of the heat of fusion can be determined as the crystalline melting point.

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 may have an aluminum content of 3 to 1000 ppm and a phosphorus content of 5 to 10000 ppm derived from the polymerization catalyst. preferable.
As another polymerization catalyst, one or more selected from titanium compounds and germanium compounds may be used.

The aluminum compound is preferably at least one selected from aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, and aluminum hydroxychloride, and at least one selected from aluminum acetate and basic aluminum acetate. is more preferred, and aluminum acetate is even more preferred.
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 small, the polymerization activity may decrease, and if the amount of aluminum is too large, a large amount of aluminum-derived foreign matter may be generated.

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

Phosphorus compound preferably has a phenol structure in the same molecule, more preferably at least one selected from phosphonic acid compounds and phosphinic acid compounds having a phenol structure in the same molecule, in the same molecule A phosphonic acid compound having a phenol structure is more preferred.

Phosphorus compounds having a phenol structure in the same molecule include p-hydroxyphenylphosphonic acid, dimethyl p-hydroxyphenylphosphonate, diethyl p-hydroxyphenylphosphonate, diphenyl p-hydroxyphenylphosphonate, bis(p-hydroxyphenyl ) phosphinic acid, methyl bis(p-hydroxyphenyl)phosphinate, phenyl bis(p-hydroxyphenyl)phosphinate, p-hydroxyphenylphenylphosphinic acid, methyl p-hydroxyphenylphenylphosphinate, p-hydroxyphenylphenylphosphinic acid phenyl, p-hydroxyphenylphosphinate, methyl p-hydroxyphenylphosphinate, phenyl p-hydroxyphenylphosphinate, diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate and the like.

Among them, the phosphorus compound is particularly preferably diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate. As such a phosphorus compound, for example, Irgamod (registered trademark) 295 (manufactured by BASF) can be used.

The amount of phosphorus is preferably 5 to 10000 ppm, more preferably 8 to 8000 ppm, and even more preferably 10 to 6000 ppm as phosphorus atoms relative to the total mass of the polyester resin. If the amount of phosphorus is small, the polymerization activity may be lowered, and a large amount of foreign matter derived from aluminum may be generated. If the amount of phosphorus is large, the catalyst cost may increase.

Titanium compounds include tetrabutyltitanium, tetrabenzyltitanium, tetra-n-propyltitanate, tetraisopropyltitanate, tetra-n-butyltitanate, tetraisobutyltitanate, tetra-tert-butyltitanate, tetracyclohexyltitanate, tetraphenyltitanate, tetra Benzyl titanate, lithium oxalate titanate, potassium oxalate titanate, ammonium oxalate titanate, titanium oxide, composite oxides of titanium and silicon, zirconium, alkali metals, alkaline earth metals, etc., titanium orthoesters or condensed orthoesters, a reaction product of titanium orthoester or condensed orthoester and hydroxycarboxylic acid, a reaction product of titanium orthoester or condensed orthoester, hydroxycarboxylic acid and a phosphorus compound, titanium orthoester or condensed orthoester and at least two Polyhydric alcohols having 1 hydroxyl group, reaction products composed of 2-hydroxycarboxylic acids and bases, among which titanium and silicon composite oxides, titanium and magnesium composite oxides, titanium orthoesters Alternatively, a reaction product consisting of a condensed orthoester, a hydroxycarboxylic acid and a phosphorus compound is preferred.
The amount of titanium is preferably 1 to 300 ppm, more preferably 2 to 200 ppm, and still more preferably 3 to 100 ppm as titanium atoms relative to the total mass of the polyester resin.
Germanium compounds include germanium dioxide, germanium acetate and the like.
The amount of germanium is preferably 1 to 500 ppm, more preferably 2 to 400 ppm, and still more preferably 3 to 300 ppm as titanium atoms relative to the total mass of the polyester resin.
The amount of atoms may be calculated, for example, by fluorescent X-ray analysis.

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

The polyester resin of the present invention has the property that the higher the temperature is above 250°C, the lower the melt tension.
In the present invention, the melt tension is preferably 15 mN or more at a temperature of 270° C., a take-up speed of 100 m/min, and a shear rate of 243 s ⁻¹ , more preferably 15 mN or more, from the viewpoint of exhibiting performance equal to or higher than that of high-density polyethylene or the like. It is 17 mN or more, 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 can be 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 , maximum take-up speed 200 m/min, take-up start speed 10 m/min, or take-up speed 100 m /min (constant), take-up time 90 seconds).

The polyester resin of the present invention has a property that at a shear rate of 2000 s ^-1 during melting, the melt viscosity decreases as the temperature rises above 250°C.
In the present invention, from the viewpoint of suppressing the occurrence of melt fracture during melt extrusion, the melt viscosity is 26000 dPa s or more 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 ^-1 . , 6500 dPa·s or less. The polyester resin of the present invention exhibits thixotropy at high temperatures during melting, can suppress the occurrence of melt fracture, and provides good moldability.

The melt viscosity at a temperature of 270° C. and a shear rate of 30 s ⁻¹ is preferably 26000 dPa·s or more, more preferably 28000 dPa·s or more, and still more preferably 30000 dPa·s or more. s or less or 45000 dPa·s or less.

Melt viscosity can be measured, for example, based on JIS K7199.
The melt viscosity at a temperature of 270° C. and a shear rate of 2000 s ⁻¹ is preferably 6500 dPa s or less, more preferably 6300 dPa s or less, and still more preferably 6200 dPa s or less. It is 5500 dPa·s or more.

The melt viscosity can be determined, for example, using a capillary rheometer under predetermined conditions (capillary length 10 mm, capillary diameter 1 mm, temperature 270° C., shear rate 30 s ⁻¹ or 2000 s ⁻¹ ).

From the viewpoint of heat resistance, the polyester resin of the present invention may have a predetermined thermal oxidation decomposition parameter (TOD) and a predetermined thermal decomposition parameter (TD). The thermal oxidative decomposition parameter (TOD) of the polyester resin is preferably 0.390 or less. The TOD can be calculated by the method described in the Examples section below. The TOD is more preferably 0.385 or less, still more preferably 0.380 or less, particularly preferably 0.375 or less, and most preferably 0.370 or less. The lower limit of the TOD is, for example, 0.010 or more or 0.020 or more. When the TOD is more than 0.390, the moldability during drawdown tends to be deteriorated.
Moreover, 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 Examples section below. TD is more preferably 0.54 or less, more preferably 0.53 or less, particularly preferably 0.52 or less, and most preferably 0.50 or less. The lower limit of the TD is, for example, 0.18 or more or 0.20 or more. When the TD is more than 0.50, the moldability during drawdown tends to be deteriorated.

The polyester resin of the present invention may contain additives such as organic, inorganic, and organometallic toners and fluorescent brighteners. By containing one or more of these additives, coloring such as yellowing of the polyester resin can be suppressed to a more excellent level. It also contains other optional polymers, antistatic agents, antifoaming agents, dyeability improvers, dyes, pigments, matting agents, optical brighteners, stabilizers, antioxidants, and other additives. good too. As antioxidants, antioxidants such as aromatic amines and phenols can be used. is available.

In addition, the polyester resin is 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 the treatment such as solid phase polymerization is completed. Molded bodies can also be used. In addition, a predetermined amount of additives such as crystallization property improvers, aldehyde reducers, color improvers, stabilizers, etc. are added to any reactor or transport pipe in the production process of the melt polycondensation polymer, and the desired results are obtained. After the melt polycondensation is performed so as to have the properties to obtain the desired properties, the product can be directly introduced into the molding process to obtain a molded product, either as it is, or after finishing treatment such as solid phase polymerization.

A polyester resin molded article made from the polyester resin of the present invention may have a predetermined three-dimensional roughness center plane average (SRa). The SRa of the polyester resin molded product is preferably less than 0.15 μm, more preferably 0.14 μm or less, still more preferably 0.13 μm or less, even more preferably 0.12 μm or less, and preferably 0.01 μm or more. Or it is 0.02 μm or more.
The center plane average (SRa) of the three-dimensional roughness can be obtained, for example, using a surface roughness measuring instrument (fine shape measuring instrument, Surfcoder ET4000A manufactured by Kosaka Laboratory Ltd.).

2. Production Method of Polyester Resin The polyester resin of the present invention can be produced by a conventionally known method. For example, when producing PET, terephthalic acid, ethylene glycol and, if necessary, other copolymerization components are directly reacted to effect esterification by distilling off water, followed by polycondensation under reduced pressure by a direct esterification method. Alternatively, dimethyl terephthalate, ethylene glycol and, if necessary, other copolymer components are reacted to distill off the methyl alcohol and transesterify, followed by polycondensation under reduced pressure. be. Further, solid state polymerization may be carried out to increase the intrinsic viscosity, if necessary. In order to promote crystallization before solid-phase polymerization, the melt-polymerized polyester may be made to absorb moisture and then heated to crystallize, or water vapor may be blown directly onto the polyester chips to crystallize by heating.
As for the method of adding the compound represented by formula (I), it is preferably added during polymerization.
The compound represented by the formula (I) may be dispersed and added at the time of addition.

The polycondensation reaction may be carried out in a batch reactor or a continuous reactor. In any of these methods, the esterification reaction or transesterification reaction may be carried out in one step, or may be carried out in multiple steps. The polycondensation reaction may be carried out in one step, or may be carried out in multiple steps. The solid-phase polymerization reaction can be carried out in a batch system or a continuous system, like the polycondensation reaction. Polycondensation and solid phase polymerization may be carried out continuously or separately.
An example of a preferred continuous production method will be described below, taking PET as an example of the polyester resin.

The esterification reaction is carried out using a multi-stage apparatus in which 1 to 3 esterification reactors are connected in series, and under the condition that ethylene glycol is refluxed, the water or alcohol produced by the reaction is removed in a rectification column. It is carried out while removing it from the system. 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/cm ² G, more preferably 0.5 to 2 kg/cm. ^2G . The temperature of the final esterification reaction is usually 250 to 290°C, preferably 255 to 275°C, and the pressure is usually 0 to 1.5 kg/cm ² G, preferably 0 to 1.3 kg/cm ² G. be. When the reaction is carried out in three or more stages, the reaction conditions for the esterification reaction in the intermediate stage are the conditions between the reaction conditions in the first stage and the reaction conditions in the final stage. These esterification reaction rate increases are preferably distributed smoothly in each stage. It is desired that the final esterification reaction rate reaches preferably 90% or more, more preferably 93% or more. A low order condensate having a molecular weight of about 500 to 5,000 is obtained by these esterification reactions.

When terephthalic acid is used as a raw material, the above esterification reaction can be carried out without a catalyst due to the catalytic action of terephthalic acid as an acid, but it may be carried out in the presence of a polycondensation catalyst.

In addition, 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 lithium carbonate. , sodium carbonate, potassium carbonate, sodium acetate, etc., by adding a small amount of a basic compound to polycondensation, the ratio of dioxyethylene terephthalate component units in the main chain of polyethylene terephthalate is reduced to a relatively low level ( 5 mol % or less relative to the total diol component), which is preferable.

Next, when producing a low polymer by transesterification, preferably 1.1 to 3.0 mol, more preferably 1.2 to 2.5 mol of ethylene glycol per 1 mol of dimethyl terephthalate. A solution containing mol is prepared and continuously supplied to the transesterification reaction step.

The transesterification reaction is carried out using an apparatus in which 1 to 2 transesterification reactors are connected in series, and under conditions where ethylene glycol is refluxed, the methanol produced by the reaction is removed from the system in a rectification column. Carry out while removing. The temperature of the first-stage transesterification reaction is preferably 180 to 250°C, more preferably 200 to 240°C. The temperature of the transesterification reaction in the final stage is usually 230 to 270°C, preferably 240 to 265°C. , Pb, Zn, Sb, Ge oxide, or the like may be used. A low order condensate having a molecular weight of about 200 to 500 is obtained by these transesterification reactions.

The obtained low-order condensate is then supplied to a multistage liquid-phase polycondensation process. As for the polycondensation reaction conditions, the reaction temperature of the first stage polycondensation is preferably 250 to 290° C., more preferably 260 to 280° C., the pressure is preferably 500 to 20 Torr, more preferably 200 to 30 Torr, The temperature of the polycondensation reaction in the final stage is preferably 265-300° C., more preferably 275-295° C., and 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 polycondensation reaction in the intermediate stage are the conditions between the reaction conditions in the first stage and the reaction conditions in the final stage. Preferably, the degree of increase in intrinsic viscosity achieved in each of these polycondensation reaction steps is smooth.

The polycondensed polyester resin thus obtained is then solid phase polymerized. The above polyester resin is solid-phase polymerized by a conventionally known method. First, the polyester resin to be subjected to solid phase polymerization is preliminarily heated at a temperature of 100 to 190° C. for 1 to 5 hours under an inert gas or under reduced pressure, or in an atmosphere of steam or steam-containing inert gas. crystallized. Solid phase polymerization is then carried out at a temperature of 190 to 230° C. for 1 to 50 hours in an inert gas atmosphere or under reduced pressure.

The catalyst used in the present invention has catalytic activity not only in polycondensation reactions but also in esterification reactions and transesterification reactions. For example, a catalyst can be used in the transesterification reaction between a dicarboxylic acid alkyl ester such as dimethyl terephthalate and a glycol such as ethylene glycol. Moreover, the catalyst used in the present invention has catalytic activity not only in melt polymerization but also in solid phase polymerization and solution polymerization, and polyester resin can be produced by any method.

The polymerization catalyst used in the present 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 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 starting the polycondensation reaction.

The addition method of the polymerization catalyst other than the phosphorus compound used in the present invention may be addition in the form of powder or neat, or addition in the form of slurry or solution of a solvent such as ethylene glycol. Well, not particularly limited. Alternatively, aluminum or an aluminum compound or a phosphorus compound and other components may be premixed and added as a mixture, or they may be added separately. Further, aluminum, an aluminum compound or a phosphorus compound and other components may be added to the polymerization system at the same time of addition, or each component may be added at different times of addition. Moreover, the total amount of the catalyst may be added at once or may be added in multiple portions.

The polyester resin of the present invention is preferably subjected to blow molding (preferably direct blow molding) after polycondensation and solid phase polymerization. In the blow molding of heat-resistant bottles, a precursor having a bottom, generally called a preform, is prepared, and this preform may be blow-stretched in a mold and heat-set. Methods such as compression molding and injection molding are used to manufacture the preform. Taking injection molding as an example, a preform can be obtained by heating and melting to 260 to 350° C. and injecting it into a preform mold. Usually, the preform has a thick-walled test-tube shape with a gate at the bottom and a screw for capping at the mouth.

For heat-resistant bottles, the spout of the obtained preform may be crystallized. Crystallization can prevent deformation of the spout even when high-temperature contents are filled. Crystallization of the spout is preferably carried out by heating to 130 to 200°C, more preferably 140 to 190°C. As a heating method, an infrared heater, hot air, induction heating, immersion in an oil bath, or the like can be used, and the use of an infrared heater is preferable from the viewpoint of productivity. The heat crystallization of the spout may be performed after the blow molding.

A preform is heated, stretched in the bottle length direction (longitudinal direction) and blow-molded in the circumferential direction to obtain a bottle. It is stretched in the longitudinal direction 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 1-10 MPa. A method of simultaneously stretching in the longitudinal direction and the circumferential direction by blowing pressurized gas while inserting a stretching rod is preferred, but stretching in the longitudinal direction may be followed by stretching in the circumferential direction. An infrared heater, hot air, induction heating, or the like is used for heating. The heating temperature is usually 80-130°C, preferably 90-120°C.

The lower limit of the draw ratio in the bottle length direction is preferably 1.5 times, more preferably 2 times. If it is less than the above, stretching may be uneven. The upper limit of the draw ratio in the bottle length direction is preferably 6 times, more preferably 5 times, and still more preferably 4 times. If the above is exceeded, tearing or the like is likely to occur.

The lower limit of the draw ratio in the bottle circumferential direction is preferably 2 times, more preferably 2.5 times. If it is less than the above, stretching may be uneven. The upper limit of the stretch ratio in the bottle circumferential direction is preferably 6 times, more preferably 5 times, and still more preferably 4 times. If the above is exceeded, tearing or the like is likely to occur.

When the blow molding is followed by heat setting in the same mold, the lower limit of the mold temperature for blow molding is preferably 80° C., more preferably 120° C., still more preferably 130° C., most preferably 140°C. If it is less than the above range, the subsequent heat setting may not promote sufficient crystallization, resulting in insufficient heat resistance, or the need to take a long heat setting time, which may lead to a decrease in productivity.

The upper limit of the mold temperature is preferably 350°C, more preferably 340°C, still more preferably 330°C, particularly preferably 320°C, and the lower limit of the mold temperature is preferably 280°C, It is more preferably 290°C, still more preferably 300°C.
Since the polyester resin of the present invention has the property that the melt tension decreases as the temperature increases during melting, when the mold temperature is increased, the melt tension decreases when the mold and the polyester resin contact each other. While the occurrence of fractures is reduced, after ejection from the mold, the melt tension will be higher and the occurrence of drawdown will be reduced.

The blow-molded bottle continues to be heat-set in the mold. The lower limit of the heat setting time is preferably 0.5 seconds, more preferably 1 second, still more preferably 1.5 seconds. If it is less than the above, sufficient crystallization may not be promoted, resulting in insufficient heat resistance. The upper limit of the heat setting time is preferably 15 seconds, more preferably 10 seconds, and even more preferably 5 seconds. A long heat setting time not only results in poor productivity, but also requires a large number of molds in the case of a rotary blow molding machine, which may result in poor economic efficiency if the apparatus is large. After heat setting in the mold, additional heat setting may be performed by further heating with infrared rays, hot air, induction heating, or the like.

It is also possible to carry out blow molding in a mold at 5 to 50°C, followed by heat setting in a heated mold. In this case, the temperature of the heatset mold is similar to the mold temperature in the above case.

The blow molding apparatus may be equipped with one mold, but in the case of mass production, it is equipped with a plurality of molds. It is preferable to use a system that sequentially moves between a place for heat setting, a place for heat setting, and a place for ejecting bottles.
Although the cold parison method of reheating the cooled preform has been described above, the hot parison method of performing blow molding without completely cooling the preform is also possible.

The content of the bottle to be molded is preferably 200 mL to 6 L, 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), hexagons, and the like.

The polyester resin of the present invention is subjected to blow molding (preferably direct blow molding) and is suitably used for containers (for example, bottles) for cosmetics, detergents, beverages, and the like.

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

Measurement of Intrinsic Viscosity IV of Polyester Resin A polyester resin was dissolved in a mixed solvent of parachlorophenol/tetrachloroethane (3/1: weight ratio) and measured at 30° C. using an Ostwald viscometer.

Measurement of Composition of Polyester Resin The composition of the polyester resin was determined by ¹ H-NMR analysis in heavy chloroform solvent using RUKER's AVANCE 500 Fourier transform nuclear magnetic resonance spectrometer and from the integral ratio thereof.

Measurement of melting point of polyester resin 5 mg of polyester resin is placed in an aluminum sample pan, sealed, and measured at 300 ° C. using a differential scanning calorimeter (DSC) DSC-Q100 manufactured by TA Instruments Japan Co., Ltd. The maximum peak temperature of the heat of fusion was determined as the crystalline melting point.

Evaluation of gel (1) Molding of hollow molded body Polyester resin is dried with a dryer using dehumidified air, and a preform is molded at a resin temperature of 290 ° C. with an M-150C-DM type injection molding machine manufactured by Meiki Seisakusho. bottom. The plug portion of this preform was heated and crystallized by a home-made plug portion crystallizer to obtain a preform. Next, this preform is biaxially stretched and blown with an LB-01E molding machine manufactured by CORPOPLAST, followed by heat setting in a mold set at about 150° C. for about 5 seconds, and a container with a capacity of 1500 cc (blow molded article ) was molded. The stretching temperature was controlled at 100°C.
(2) Appearance of hollow molded body (confirmation of gel contaminants)
100 hollow molded articles were visually observed and evaluated as follows.
○: Transparent and no problem in appearance △ ~ ○: One bottle with gel foreign matter can be visually confirmed per 100 hollow molded bodies △: Two bottles with gel foreign matter can be visually confirmed per 100 hollow molded bodies ×: Hollow Three or more bottles with gel foreign matter can be visually confirmed per 100 molded products.

Measurement of Melt Tension Melt tension was measured using the following equipment and conditions during molding of the polyester resin.
Capillary rheometer (Toyo Seiki Seisakusho)
Temperature: 270°C
Capillary length: 10mm
Capillary diameter: 1 mm
Shear rate: 243s ^-1
Maximum pick-up speed: 200m/min
Pick-up start speed: 10m/min
Or take-up speed: 100m/min (constant)
Collection time: 90sec

Measurement of Melt Viscosity Melt tension was measured using the following equipment and conditions during molding of the polyester resin.
Capillary rheometer (Toyo Seiki Seisakusho)
Capillary length: 10mm
Capillary diameter: 1 mm
Temperature: 270°C
Shear rate: 30s ^-1 or 2000s ^-1

Measurement of acid value (terminal carboxyl group concentration (unit: eq/ton, expressed as acid value)) Dissolve 0.5 g of polyester resin in 25 ml of benzyl alcohol, and use a benzyl alcohol solution of 0.01 mol/l sodium hydroxide. and titrated. 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.

Measurement of the amount of aluminum atoms, phosphorus atoms, germanium atoms, and titanium atoms in the polyester resin Polyester resin was heated to a melting point +20 ° C in a stainless steel circular ring with a thickness of 5 mm and an inner diameter of 50 mm to prepare a sample piece. Elemental amounts were determined by fluorescent X-ray analysis and displayed in ppm. In determining the amount, a calibration curve obtained in advance from samples with known amounts of each element was used.

Profile extrusion molding (evaluation of moldability (drawdown), mechanical properties, surface smoothness, transparency)
Set the polyester resin cylinder temperature to 270°C, attach a die lip to a single screw extruder (L/D = 30, full flight screw, screw diameter 50 mm), and then determine the final dimensions of the profile extruded product at the tip of the cooling water tank. A sizing mold is installed, and the product is molded by a profile extrusion molding facility equipped with a take-up machine via a water tank, and the drawdown during molding and the mechanical properties, surface smoothness, and transparency of the molded product are evaluated according to the following criteria. was evaluated according to Table 2 shows the results.

Evaluation of moldability (drawdown) Drawdown was evaluated according to the following criteria.
◎: The shape is maintained without dripping of the polyester resin at all during molding. ○: A slight dripping of the polyester resin is generated during molding. Sometimes it is not possible to pass the resin from the die lip to the sizing mold due to dripping polyester resin.

Evaluation of Mechanical Properties (Strength) of Molded Article A polyester resin molded article was bent at 180° and evaluated according to the following criteria.
○: No cracks observed with a 50x loupe △: No cracks visually observed, but cracks observed with a 50x loupe ×: Visually cracked

Evaluation of surface smoothness The unevenness of the outer surface of the polyester resin molded product was measured using a Surfcoder Et4000A manufactured by Kosaka Laboratory, and compared with 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 △ ~ ◯: 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 more

Evaluation of Transparency A molded plate having a thickness of 7 mm was molded under the following conditions.
The polyester resin was preliminarily dried under reduced pressure using a vacuum dryer Model DP61 manufactured by Yamato Scientific, and the inside of the molding material hopper was purged with a dry inert gas (nitrogen gas) in order to prevent moisture absorption during molding. The conditions for plasticization by the M-150C-DM injection molding machine are feed screw rotation speed = 70%, screw rotation speed = 120 rpm, back pressure 0.5 MPa, cylinder temperature 45 ° C, 250 ° C in order from directly below the hopper, and nozzles thereafter. was set to 290° C. including The injection speed and pressure holding speed were adjusted to 20%, and the injection pressure and holding pressure were adjusted so that the weight of the molded product was 146 ± 0.2 g. It was adjusted. The upper limits of the injection time and pressure holding time are set to 10 seconds and 7 seconds, respectively, and the cooling time is set to 50 seconds. Cooling water having a temperature of 10°C is constantly introduced into the mold for temperature control, but the mold surface temperature is around 22°C when the molding is stable. The molded plate for evaluation was arbitrarily selected from stable molded plates at 11th to 18th shots from the start of molding after the introduction of the molding material and replacement with the resin.
The HAZE of the molded plate was measured with 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 5% or more and less than 8% △ ~ 〇: HAZE is 8% or more and less than 10% ×: HAZE is 10% or more

Evaluation of Thermal Oxidative Stability (Thermal Oxidative Degradation Parameter (TOD)) Resin chips ([IV] _i ) of polyester resin were freeze-pulverized into 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 having an inner diameter of about 8 mm and a length of about 140 mm and vacuum-dried at 70° C. for 12 hours. Next, a drying tube containing silica gel was attached to the upper part of the test tube, and the [IV] _f1 was measured after being immersed in a nitrate bath at 200° C. for 15 minutes under dry air. TOD was determined as follows. However, [IV] _i and [IV] _f1 refer to IV (dL/g) before and after the heating test, respectively. Freeze pulverization was performed using a freezer mill (Model 6750, manufactured by Spex, Inc., USA). After putting about 2 g of resin chips and a dedicated impactor in the special cell, set the cell in the device, fill the device with liquid nitrogen, hold it for about 10 minutes, and then set it to RATE 10 (the impactor moves about 20 times per second). back and forth) for 5 minutes.
TOD = 0.245 {[IV] _f1-1.47- [IV] _i ^-1.47 ^}
A smaller TOD value of the polyester resin indicates higher thermal oxidation stability.

Evaluation of thermal stability (thermal decomposition parameter (TD)) 3 g of dried polyester resin chips were placed in a glass test tube and immersed in an oil bath at 280°C for 120 minutes in a nitrogen atmosphere to melt. [IV] _f1 was measured after heating. TD was determined as follows. However, [IV] _i and [IV] _f1 refer to IV (dL/g) before and after the heating test, respectively.
^TD = 0.245 {[IV] _f1-1.47- [IV] _i ^-1.47 }
A smaller TD value of the polyester resin indicates higher thermal stability.

Synthesis Examples 1 to 6 (Preparation of Compound (Branching Agent) Represented by Formula (I))
Compounds of formula (I) are prepared in a two gallon free radical continuous polymerization reaction as described in US Pat. prepared in situ. The compositions and weight-average molecular weights of the compounds represented by Formula (I) obtained in Synthesis Examples 1 to 6 are shown in Table 1 below.
The weight average molecular weight of the compound represented by formula (I) was calculated by GPC in terms of standard polystyrene. Specifically, 4 mg of a sample of the compound represented by formula (I) is weighed, dissolved in 4 ml of a mixed solvent of chloroform and isofluoroisopropanol (60/40% by volume), and filtered through a 0.2 μm membrane filter. Then, the obtained sample solution was measured by GPC and converted to standard polystyrene to obtain the weight average molecular weight.

l, m and n of the compound represented by formula (I) were determined by 1H-NMR and 13C-NMR analyses.
That is, l, m, and n were expressed as integers by rounding off one decimal place as the average number. Specifically, a sample of the compound represented by formula (I) was prepared in a mixed solvent of deuterated chloroform/trifluoroacetic acid (85/15 by volume) for 1H-NMR, and deuterated chloroform or a heavy solvent for 13C-NMR. After dissolving in a mixed solvent of hydrogenated chloroform/hexafluoroisopropanol (volume ratio is 1/1), with a Fourier transform nuclear magnetic resonance spectrometer (AVANCE NEO600 manufactured by BRUKER), the number of integration times is 50 to 200 (1H-NMR), 10000 times ( 13C-NMR) conditions, at room temperature. From the 1H-NMR and 13C-NMR spectra, the ratio of each component and the ratio of components positioned at the ends were calculated, and l, m and n were obtained.

In addition, the compound represented by formula (I) used in the synthesis examples has the following methacrylic monomer structural unit (hereinafter abbreviated as DEMA-E structural unit) (* indicates other monomer structural unit (for example, styrene structural unit unit, represents a bond with the methyl methacrylate structural unit)). For example, a compound containing this DEMA-E structural unit can be obtained by a method of synthesizing glycidyl methacrylate by ring-opening reaction with water and adding a diol, a method of synthesizing by adding a diol to methacrylic acid, or the like. . Further, copolymers of styrene and glycidyl methacrylate and/or methyl methacrylate are synthesized according to US Patent Application Nos. 09/354,350 and 09/614,402, followed by ring-opening with water. It may be subjected to a method of synthesizing by adding a diol.

<DEMA-E structural unit>

The abbreviations used below are STY = styrene, MMA = methyl methacrylate, DEMA-E = methacrylic monomer structural unit of the above chemical formula.

Example 1
2432 g of terephthalic acid (Mitsui Chemicals Co., Ltd.), 1772 g of ethylene glycol (Nippon Shokubai Co., Ltd.), bisphenol A-EO adduct (Sanyo Kasei BPE-20F ) 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 the formula (I) obtained in Synthesis Example 1 was continuously added to 0.2% by mass with respect to 100% by mass of the alcohol component of the resulting polyester resin while controlling the flow rate. , allowing the reaction to proceed stepwise.

With respect to the mass of the polyester resin, add 30 ppm of aluminum acetate as an aluminum atom and 72 ppm of Irgamod 295 (manufactured by BASF) as a phosphorus atom as a polycondensation catalyst, and then add 1 ppm of Solvent Blue 45 (manufactured by Clariant) to the polyester resin. The mixture was stirred at 260° C. for 5 minutes under normal pressure in a nitrogen atmosphere. After that, the pressure of the reaction system was gradually lowered to 13.3 Pa (0.1 Torr) while the temperature was raised to 280° C. over 60 minutes, and polycondensation reaction was further carried out at 280° C. and 13.3 Pa. Following the pressure release, the resin under slight pressure was extruded into cold water in the form of a strand, rapidly cooled, held in cold water for 20 seconds, and cut to obtain cylindrical pellets with a length of about 3 mm and a diameter of about 2 mm. rice field.

The polyester pellets obtained by melt polymerization were dried under reduced pressure (13.3 Pa or less, 80°C, 12 hours), and then subjected to crystallization treatment (13.3 Pa or less, 130°C, 3 hours, further 13.3 Pa or less, 160° C., 3 hours) was performed. The polyester pellets after standing to cool are solid-phase polymerized in a solid-phase polymerization reactor while maintaining the system at 13.3 Pa or less and 200° C. to 220° C. to obtain polyester pellets having an IV of 1.11 dl / g. rice field. The ratio of the diol component of the polyester resin was 95 mol % of ethylene glycol and 5 mol % of the bisphenol A-EO adduct. Table 2 shows the results of each evaluation.

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

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

Example 4
In Example 1, the compound represented by Formula (I) obtained in Synthesis Example 1 was changed to the compound represented by Formula (I) obtained in Synthesis Example 2, and polymerized under the same conditions as in Example 1. was performed to obtain polyester pellets.

Example 5
In Example 1, the compound represented by Formula (I) obtained in Synthesis Example 1 was changed to the compound represented by Formula (I) obtained in Synthesis Example 3, and polymerized under the same conditions as in Example 1. was performed to obtain polyester pellets.

Example 6
In Example 1, the compound represented by Formula (I) obtained in Synthesis Example 1 was changed to the compound represented by Formula (I) obtained in Synthesis Example 4, and polymerized under the same conditions as in Example 1. was performed to obtain polyester pellets.

Example 7
In Example 1, the compound represented by Formula (I) obtained in Synthesis Example 1 was changed to the compound represented by Formula (I) obtained in Synthesis Example 5, and polymerized under the same conditions as in Example 1. was performed to obtain polyester pellets.

Example 8
In Example 1, the compound represented by Formula (I) obtained in Synthesis Example 1 was changed to the compound represented by Formula (I) obtained in Synthesis Example 6, and polymerized under the same conditions as in Example 1. was performed to obtain polyester pellets.

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.

Example 10
Polymerization was carried out under the same conditions as in Example 1 except that the amount of ethylene glycol charged was changed to 1002 g and the esterification time was changed to 1.0 hour to obtain polyester pellets.

Example 11
In Example 1, germanium dioxide as a polycondensation catalyst was changed to 100 ppm of germanium atoms relative to the mass of the polyester resin, and triethyl phosphate was changed to 30 ppm of 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.

Example 12
In Example 1, tetrabutyl titanium as a polycondensation catalyst is changed so that the titanium atom atom is 10 ppm relative to the mass of the polyester resin, and triethyl phosphate is changed so that the phosphorus atom atom is 100 ppm relative to the mass of the polyester resin. , Polymerization was carried out under the same conditions as in Example 1 to obtain polyester pellets.

Example 13
In Example 1, the conditions were the same as in Example 1, except that the charging amount was changed so that the diol component of the polyester resin had a ratio of 2 mol% of the bisphenol A-EO adduct with respect to 98 mol% of ethylene glycol. Polymerization was carried out to obtain polyester pellets.

Example 14
In Example 1, the conditions were the same as in Example 1, except that the charging amount was changed so that the ratio of the diol component of the polyester resin was 15 mol% of the bisphenol A-EO adduct with respect to 85 mol% of ethylene glycol. Polymerization was carried out to obtain polyester pellets.

Comparative example 1
In Example 1, without adding the compound represented by formula (I), as a polycondensation catalyst, germanium dioxide was added to the polyester resin so that the germanium atom was 100 ppm with respect to the mass of the polyester resin, and triethyl phosphate was added to the polyester resin. Polymerization was carried out under the same conditions as in Example 1, except that the amount of phosphorus atoms was changed to 30 ppm with respect to the mass, to obtain polyester pellets.

Comparative example 2
In Example 1, the amount of the compound represented by Formula (I) obtained in Synthesis Example 1 was changed to 0.0001% by mass, and germanium dioxide was added as a polycondensation catalyst to the mass of the polyester resin. Polymerization was carried out under the same conditions as in Example 1, except that the amount of triethyl phosphate was changed to 30 ppm of phosphorus atoms with respect to the mass of the polyester resin so as to obtain 100 ppm atoms, to obtain polyester pellets.

Comparative example 3
In Example 1, the addition amount of the compound represented by Formula (I) obtained in Synthesis Example 1 was changed to 6% by mass, and germanium dioxide was used as a polycondensation catalyst in an amount of germanium atom 100 ppm with respect to the mass of the polyester resin. Polymerization was carried out under the same conditions as in Example 1, except that triethyl phosphate was changed to 30 ppm of phosphorus atoms with respect to the mass of the polyester resin, to obtain polyester pellets.

Comparative example 4
In Example 1, as the polycondensation catalyst, germanium dioxide was changed so that the germanium atom was 100 ppm relative to the mass of the polyester resin, and triethyl phosphate was changed so that the phosphorus atom was 30 ppm relative to the mass of the polyester resin. Polymerization was carried out under the same conditions as in Example 1, except that the charging amount was changed so that the diol component of the polyester resin had a ratio of 1 mol% of the bisphenol A-EO adduct to 99 mol% of ethylene glycol. A pellet was obtained.

Comparative example 5
In Example 1, as the polycondensation catalyst, germanium dioxide was changed so that the germanium atom was 100 ppm relative to the mass of the polyester resin, and triethyl phosphate was changed so that the phosphorus atom was 30 ppm relative to the mass of the polyester resin. Polymerization was carried out under the same conditions as in Example 1, except that the charging amount was changed so that the diol component of the polyester resin had a ratio of 16 mol% of the bisphenol A-EO adduct to 84 mol% of ethylene glycol. A pellet was obtained.

In Examples 1 to 14, the melt viscosity was 26000 dPa·s or more at a temperature of 270° C. and a shear rate of 30 s ⁻¹ and was 6500 dPa·s or less at a temperature of 270° C. and a shear rate of 2000 s ⁻¹ .

The polyester resin of the present invention has improved moldability in extrusion molding, profile extrusion molding, direct blow molding, inflation molding, injection blow molding, calendering molding, which requires high melt tension, and mechanical properties while maintaining transparency. It is expected that the improvement of characteristics can be realized and that it will greatly contribute to the industrial world.

Claims

Terephthalic acid as a dicarboxylic acid component, ethylene glycol, a bisphenol A-ethylene oxide adduct as an alcohol component, and a compound represented by the following formula (I) are constituent components, and terephthalic acid is 85 to 100 mol% in the dicarboxylic acid component. There is a ratio of 2 to 15 mol% of the bisphenol A-ethylene oxide adduct to 85 to 98 mol% of ethylene glycol, and the compound represented by the following formula (I) is 0.001 to 0.001 in 100% by mass of the alcohol component. A polyester resin characterized by comprising 5% by mass.

(wherein m and n are each an integer of 1 to 1000, l is an integer of 0 to 1000, R 1 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms, R 2 , R 3 , Each R 4 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)
The polyester resin according to claim 1, wherein the compound represented by formula (I) has a weight average molecular weight of 200 or more and 500,000 or less.
3. The polyester resin according to claim 1, which has a melt tension of 15 mN or more at a temperature of 270° C., a take-up speed of 100 m/min and a shear rate of 243 s −1 .
3. The polyester resin according to claim 1, which has a melt viscosity of 26000 dPa·s or more at a temperature of 270° C. and a shear rate of 30 s −1 and 6500 dPa·s or less at a temperature of 270° C. and a shear rate of 2000 s −1 . .