Catalyst particles for polyester production and method for producing polyester using the same

Abstract

The present invention provides a catalyst particle for producing a polyester having a good color tone and a good transparency (low haze) after molding, and a method for producing a polyester using the same. The catalyst particle of the present invention is a reaction product of a titanium compound component (A) and a phosphorus compound component (B) containing the following 50 particle diameter D 90 of 10.0 μm or less and a particle diameter D 90 of 20.0 μm or less; (A) a titanium compound component consisting of at least one of a titanium compound (1) selected from the group consisting of titanium compounds represented by the following general formula (I), and a titanium compound (2) obtained by reacting the titanium compound (1) of the above general formula (I) with an aromatic polycarboxylic acid or anhydride thereof represented by the following general formula (II); (B) a phosphorus compound component consisting of at least one of a phosphorus compound (3) represented by the following general formula (III).

Description

Technical Field

[0001] This invention relates to catalyst particles for polyester manufacturing and a method for manufacturing polyester using the same. More specifically, this invention relates to catalyst particles for polyester manufacturing containing specific titanium and phosphorus compounds, and a method for manufacturing polyester having a good color tone and good transparency (low haze) after molding using the same. Background Technology

[0002] Polyesters, especially polyethylene terephthalate, polyethylene naphthalate, polyethylene terephthalate and polyethylene terephthalate, are widely used in fibers, films and other molded products due to their excellent mechanical, physical and chemical properties.

[0003] As a method for manufacturing, for example, polyethylene terephthalate, there are generally known methods that involve: directly esterifying terephthalic acid with ethylene glycol; or transesterifying a lower alkyl ester of terephthalic acid, such as dimethyl terephthalate, with ethylene glycol; or reacting terephthalic acid with ethylene oxide to prepare a reaction product containing terephthalic acid in the form of a ethylene glycol ester and / or its oligomers. This reaction product is then heated under reduced pressure to a predetermined degree of polymerization in the presence of a polymerization catalyst to induce a polycondensation reaction. In addition, polyethylene naphthalate, polyethylene terephthalate (TIM), and polyethylene terephthalate (TETM) are also manufactured using the same methods described above.

[0004] It is well known that in the aforementioned polycondensation reaction, the reaction rate and the quality of the resulting polyester are greatly affected by the type of catalyst used. Antimony compounds are the most widely used catalysts for the polycondensation of polyethylene terephthalate. Antimony compound catalysts exhibit excellent polycondensation catalytic performance, and the polyesters obtained using them have good color tones.

[0005] However, using antimony compounds as polycondensation catalysts presents the following problem: if the obtained polyester is continuously melt-spun for an extended period, foreign matter (hereinafter, sometimes simply referred to as spinneret foreign matter) adheres to and accumulates around the spinneret orifice. This causes bending of the molten polymer stream extruded from the spinneret, which in turn causes problems such as fuzzing and / or breakage in the resulting fiber yarns during the spinning and / or stretching processes. Titanium compounds, such as tetrabutyl titanate, have also been proposed as polycondensation catalysts other than the aforementioned antimony compounds. While using such titanium compounds can solve the problems caused by spinneret foreign matter accumulation, it introduces new problems such as the resulting polyester being colored yellow and exhibiting poor melt thermal stability.

[0006] To address the aforementioned coloring issues, cobalt compounds are typically added to polyester as hue modifiers to suppress yellowing. While adding cobalt compounds does improve the hue (b-value) of polyester, it also reduces the melt thermal stability of the polyester, leading to polymer decomposition.

[0007] In addition, as other titanium compounds, Patent Document 1 discloses the use of titanium hydroxide as a catalyst for polyester manufacturing, and Patent Document 2 discloses the use of α-titanic acid as a catalyst for polyester manufacturing. However, in the former method, titanium hydroxide is difficult to pulverize, while in the latter method, α-titanic acid is prone to deterioration, making its storage and handling difficult. Therefore, none of the above catalysts are suitable for industrial use, and it is also difficult to obtain polymers with good color (b-value) using the above catalysts.

[0008] Furthermore, Patent Document 3 describes using the product obtained by reacting a titanium compound with trimellitic acid as a catalyst for polyester manufacturing, and Patent Document 4 discloses using the product obtained by reacting a titanium compound with a phosphite as a catalyst for polyester manufacturing. While these methods do improve the melt thermal stability of polyester to some extent, the resulting polyester lacks sufficient color hue. Therefore, further improvement in the color hue of the polyester is desired.

[0009] In addition, Patent Document 5 proposes using a complex of titanium and phosphorus compounds as a catalyst for polyester manufacturing. By using this method, the melt thermal stability is improved to some extent, but the color of the resulting polymer is unsatisfactory.

[0010] Therefore, Patent Document 6 proposes a catalyst for polyester manufacturing containing reaction products of specific titanium compounds and phosphorus compounds. However, the polyester obtained using this catalyst has insufficient transparency after molding, and it is hoped that this can be improved.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Publication No. 48-2229

[0014] Patent Document 2: Japanese Patent Publication No. 47-26597

[0015] Patent Document 3: Japanese Patent Publication No. 59-46258

[0016] Patent Document 4: Japanese Patent Application Publication No. 58-38722

[0017] Patent Document 5: Japanese Patent Application Publication No. 7-138354

[0018] Patent Document 6: WO2003 / 008479 Summary of the Invention

[0019] The object of this invention is to provide catalyst particles for manufacturing polyesters with good hue and good transparency (low haze) after molding, and a method for manufacturing polyesters using the same.

[0020] The above-mentioned objective is achieved by the catalyst particles for polyester manufacturing of the present invention and the method for manufacturing polyester using the present invention.

[0021] Method 1

[0022] A catalyst particle for polyester manufacturing contains the reaction product of a titanium compound (A) and a phosphorus compound (B).

[0023] Particle size D 50 Below 10.0 μm, and

[0024] Particle size D 90 Below 20.0 μm

[0025] (A) is composed of at least one titanium compound (1) and titanium compound (2) represented by the following general formula (I), wherein the titanium compound (2) is obtained by reacting the titanium compound (1) of the above general formula (I) with an aromatic polycarboxylic acid or its anhydride represented by the following general formula (II).

[0026]

[0027] [In formula (I), R] 1 R 2 R 3 and R 4 Each of these terms independently represents an alkyl group having 2 to 10 carbon atoms, where k represents an integer from 1 to 3, and when k is 2 to 3, there are 2 or 3 R groups. 2 base and R 3 Each base can be the same as or different from the others.

[0028]

[0029] [In equation (II), m represents an integer from 2 to 4]

[0030] (B) Consists of at least one of the phosphorus compounds (3) represented by the following general formula (III),

[0031]

[0032] [Among them, in formula (III), R] 5[This refers to an unsubstituted or substituted aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms].

[0033] Method 2

[0034] According to the catalyst particles for polyester manufacturing described in Method 1, in the reaction product of the titanium compound component (A) and the phosphorus compound component (B), the reaction molar ratio (mTi:mP) of the titanium atom molar amount (mTi) of the titanium compound component (A) and the phosphorus atom molar amount (mP) of the phosphorus compound component (B) is in the range of 1:1 to 1:3.

[0035] Method 3

[0036] The catalyst particles for polyester manufacturing according to method 1 or 2, wherein the titanium compound (1) of formula (I) above is selected from tetraalkyl titanate, octaalkyl tritiate and hexaalkyl distitanate.

[0037] Method 4

[0038] The catalyst particles for polyester manufacturing according to any one of methods 1 to 3, wherein the aromatic polycarboxylic acid or its anhydride of formula (II) above is selected from phthalic acid, trimellitic acid, triphenyl sulfide and pyromellitic acid or their anhydrides.

[0039] Method 5

[0040] The catalyst particles for polyester manufacturing according to any one of methods 1 to 4, wherein the titanium compound (2) is a reaction product of the titanium compound (1) of formula (I) and the aromatic polycarboxylic acid or its anhydride of formula (II) in a molar ratio of 2:1 to 2:5.

[0041] Method 6

[0042] The catalyst particles for polyester manufacturing according to any one of methods 1 to 5, wherein the phosphorus compound (3) of formula (III) is selected from at least one of monomethyl phosphate, monoethyl phosphate, monotrimethyl phosphate, monobutyl phosphate, monohexyl phosphate, monoheptyl phosphate, monooctyl phosphate, monononyl phosphate, monodecyl phosphate, monododecyl phosphate, monolauryl phosphate, monooleyl phosphate, monotetradecyl phosphate, monophenyl phosphate, monobenzyl phosphate, mono(4-dodecyl)phenyl phosphate, mono(4-methylphenyl) phosphate, mono(4-ethylphenyl) phosphate, mono(4-propylphenyl) phosphate, mono(4-dodecylphenyl) phosphate, monotolyl phosphate, monoxyl phosphate, monobiphenyl phosphate, mononaphthalene phosphate, and monoanthracite phosphate.

[0043] Method 7

[0044] The catalyst particles for polyester manufacturing according to any one of methods 1 to 6 contain: a reaction product of a titanium compound component (A) composed of at least one titanium compound of formula (I) (where k represents 1) and a phosphorus compound component (B) composed of at least one phosphorus compound (3) of formula (III).

[0045] Method 8

[0046] According to the catalyst particles for polyester manufacturing described in Method 7, the reaction product of a titanium compound component (A) composed of at least one titanium compound from Formula (I) (where k represents 1) and a phosphorus compound component (B) composed of at least one phosphorus compound (3) from Formula (III) comprises a compound represented by Formula (IV).

[0047]

[0048] In the above formula, R 6 and R 7 Each of the above can be used independently to represent an alkyl group having 2 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms.

[0049] Method 9

[0050] The catalyst particles for polyester manufacturing according to any one of methods 1 to 8, wherein the reaction product of the titanium compound component (A) and the phosphorus compound component (B) is generated at a reaction temperature of 50 to 200°C with a reaction start temperature of 25 to 35°C.

[0051] Method 10

[0052] A method for manufacturing a polyester includes feeding a polymerization starting material composed of at least one of esters selected from aromatic dicarboxylic acids and alkyl diols and their oligomers into a polycondensation reaction in the presence of catalyst particles for polyester manufacturing as described in any one of methods 1 to 9.

[0053] Method 11

[0054] According to the polyester manufacturing method of method 10, the amount of titanium atoms contained in the catalyst particles is 2 to 40% relative to the total millimoles of the aromatic dicarboxylic acid components contained in the above-mentioned polymerization starting material.

[0055] Method 12

[0056] According to the method for manufacturing polyester of method 10 or 11, wherein the aromatic dicarboxylic acid is selected from terephthalic acid, isophthalic acid, naphthalic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid and β-hydroxyethoxybenzoic acid.

[0057] Method 13

[0058] According to the method for manufacturing polyester of method 12, the terephthalic acid is obtained by depolymerizing poly(alkyl terephthalate) and hydrolyzing the resulting dimethyl terephthalate.

[0059] Method 14

[0060] According to the polyester manufacturing method of method 10 or 11, wherein the ester of the aromatic dicarboxylic acid and alkyldiol is an ester of terephthalic acid and alkyldiol, which is obtained by depolymerizing poly(alkyl terephthalate) and subjecting the resulting dimethyl terephthalate to an alkyldiol transesterification reaction.

[0061] Method 15

[0062] The method for manufacturing polyester according to method 13 or 14, wherein the poly(terephthalic acid) diol ester supplied for the above-mentioned depolymerization is a discarded poly(terephthalic acid) diol ester molded article and / or polymer scraps recovered in the manufacturing process of poly(terephthalic acid) diol ester.

[0063] Method 16

[0064] The method for manufacturing polyester according to any one of methods 10 to 15, wherein the alkyl glycol is selected from ethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol and hexamethylene glycol.

[0065] Method 17

[0066] The method for manufacturing polyester according to any one of methods 10 to 16, wherein the polycondensation reaction is carried out at a temperature of 230 to 320°C.

[0067] Method 18

[0068] A polyester is manufactured by any one of methods 10 to 17.

[0069] Method 19

[0070] The polyester according to method 18 has an intrinsic viscosity of 0.30 to 0.90, the content of the cyclic trimer of the ester of the aromatic dicarboxylic acid and the alkyl diol is 0.50% by mass or less, and the content of acetaldehyde is 5 ppm or less.

[0071] Method 20

[0072] The polyester according to method 18 or 19 contains at least one hindered phenolic compound in an amount of less than 1% by mass relative to the mass of the polyester.

[0073] Method 21

[0074] A molded article comprising the polyester described in any one of methods 18 to 20.

[0075] Method 22

[0076] The molded article according to method 21 is selected from bottles, sheets, thermoformed containers and injection molded articles.

[0077] Method 23

[0078] A polyester fiber is obtained by melting a resin raw material containing the polyester described in any one of methods 18 to 20, extruding the melt into a fibrous form, and then solidifying it.

[0079] Method 24

[0080] A polyester film is obtained by melting a resin raw material containing the polyester described in any one of methods 18 to 20, extruding the melt into a sheet and solidifying it, and stretching the resulting unstretched film in a biaxial direction.

[0081] Polyesters obtained using the catalyst particles of this invention have good color tone and good transparency (low haze) after molding, making them suitable for various molded products, and their industrial effects are significant. Detailed Implementation

[0082] The catalyst particles for polyester manufacturing of the present invention contain the reaction product of titanium compound component (A) and phosphorus compound component (B) as described in the detailed description below, and have a particle size D. 50 The particle size is below 10.0 μm and the particle size D 90 It is below 20.0μm.

[0083] Particle size D 50 Preferably, the particle size is 7.0 μm or less, more preferably 5.0 μm or less, even more preferably 4.8 μm or less, and particularly preferably 4.7 μm or less. Additionally, the particle size D... 90 Preferably, the particle size is 18.0 μm or less, more preferably 16.0 μm or less, even more preferably 15.0 μm or less, and particularly preferably 14.5 μm or less. If the particle size of the catalyst particles for polyester manufacturing is within the above range, it has the following advantages: not only does the polyester obtained using these catalyst particles have a good color tone, but the polyester after molding also exhibits good transparency (low haze). Furthermore, the particle size D of the catalyst particles... 10 Preferably, the micrometer is 5.0 μm or less, more preferably 4.0 μm or less, even more preferably 3.0 μm or less, and particularly preferably 2.0 μm or less. By being within the above range, the same effect as described above can be obtained.

[0084] In addition, D90 / D 10 The indicated particle size distribution is preferably 15.0 or less, more preferably 10.0 or less, even more preferably 8.0 or less, and particularly preferably 5.0 or less. By setting the particle size distribution within the above range, the same effect as described above can be obtained.

[0085] Here, the particle size of the catalyst particles is determined by the particle size distribution obtained by feeding catalyst particles dissolved in ethylene glycol into a laser diffraction particle size distribution measuring device. 10 D 50 D 90 These are the particle sizes whose cumulative values ​​are 10%, 50%, and 90% of the particle size distribution, respectively. D 50 D represents the average particle size (median particle size). 50 The smaller the value, the smaller the average particle size. Furthermore, the evaluation of particle size distribution utilizes D... 90 / D 10 Proceed, D 90 / D 10 The smaller the particle size, the narrower the particle size distribution.

[0086] In the reaction product of the above-mentioned titanium compound component (A) and the above-mentioned phosphorus compound component (B), the molar amount (m) of titanium atoms in the above-mentioned titanium compound component (A) is... Ti The molar amount of phosphorus atoms converted to the above-mentioned phosphorus compound component (B) (m P The reaction molar ratio m Ti :m P Preferably, the ratio is in the range of 1:1 to 1:3, and more preferably in the range of 1:1 to 1:2.

[0087] The molar amount of titanium atoms in the aforementioned titanium compound component (A) refers to the sum of the products of the molar amounts of each titanium compound contained in the aforementioned titanium compound component (A) and the number of titanium atoms contained in one molecule of that titanium compound. Similarly, the molar amount of phosphorus atoms in the aforementioned phosphorus compound component (B) refers to the sum of the products of the molar amounts of each phosphorus compound contained in the aforementioned phosphorus compound component (B) and the number of phosphorus atoms contained in one molecule of that phosphorus compound. Since each molecule of the phosphorus compound in formula (III) contains one phosphorus atom, the molar amount of phosphorus atoms in the phosphorus compound is equal to the molar amount of that phosphorus compound.

[0088] If the reaction molar ratio m Ti :m P A ratio greater than 1:1, i.e., an excessive amount of titanium compound component (A), can sometimes result in poor hue (excessively high b-value) and decreased heat resistance in the polyester obtained using the catalyst. Furthermore, if the above reaction molar ratio m... Ti :m PIf the ratio is less than 1:3, that is, if the amount of titanium compound component (A) is too small, the catalyst particles obtained may sometimes become insufficiently active relative to the catalytic activity of the polyester formation reaction.

[0089] <Titanium compound composition (A)>

[0090] The titanium compound component (A) used in the catalyst particles of the present invention is composed of at least one of titanium compound (1) and titanium compound (2) represented by the following general formula (I), wherein the titanium compound (2) is obtained by reacting the titanium compound (1) of the following general formula (I) with an aromatic polycarboxylic acid or its anhydride represented by the following general formula (II).

[0091]

[0092]

[0093] In equation (I), R 1 R 2 R 3 and R 4 Each refers to an alkyl group having 2 to 10, preferably 2 to 6, carbon atoms, whether they are the same or different from each other; k represents an integer from 1 to 3, preferably 1; when k represents 2 or 3, there are 2 or 3 R groups. 2 and R 3 They can be the same as or different from each other.

[0094] In addition, in formula (II), m represents 2 to 4, preferably an integer of 2 or 3.

[0095] Examples of titanium compounds (1) of general formula (I) include tetraalkyl titanates such as tetrabutyl titanate, tetraisopropyl titanate, tetrapropyl titanate and tetraethyl titanate, as well as alkyl titanates such as trioctyl titanate and hexaalkyl titanate. Among these, tetraalkyl titanates that are highly reactive with the phosphorus compound components used in this invention are preferred, and tetrabutyl titanate is particularly preferred.

[0096] The aromatic polycarboxylic acids of general formula (II) and their anhydrides are preferably selected from phthalic acid, trimellitic acid, triphenylcarboxylic acid, pyromellitic acid and their anhydrides. In particular, trimellitic anhydrides that have good reactivity with titanium compound (1) and high affinity for the polyester of the obtained polycondensation catalyst are more preferred.

[0097] The reaction of titanium compound (1) with an aromatic polycarboxylic acid of general formula (II) or its anhydride is carried out by mixing the aromatic polycarboxylic acid or its anhydride in a catalyst, dissolving part or all of it in a solvent, adding titanium compound (1) dropwise to the mixture, and heating at a temperature of 0°C to 200°C for at least 30 minutes, preferably at a temperature of 30°C to 150°C for 40 to 90 minutes. There is no particular limitation on the reaction pressure; atmospheric pressure is sufficient. It should be noted that the catalyst can be appropriately selected from substances capable of dissolving part or all of the desired amount of the compound of formula (II) or its anhydride, preferably ethanol, ethylene glycol, trimethylene glycol, tetramethylene glycol, benzene, and xylene.

[0098] The molar ratio of titanium compound (1) to the compound of formula (II) or its anhydride is not limited. However, if the proportion of titanium compound (1) is too high, the color tone of the resulting polyester may deteriorate or the softening point may decrease; conversely, if the proportion of titanium compound (1) is too low, the polycondensation reaction may be difficult to carry out. Therefore, the molar ratio of titanium compound (1) to the compound of formula (II) or its anhydride is preferably controlled in the range of 2:1 to 2:5. The reaction product obtained by this reaction can be directly used for the reaction with the phosphorus compound (3) described below, or it can be purified by recrystallization using a solvent composed of acetone, methanol and / or ethyl acetate, etc., and then reacted with the phosphorus compound (3).

[0099] <Titanium compound composition (B)>

[0100] Furthermore, the phosphorus compound component (B) used in the catalyst particles of the present invention is composed of at least one of the phosphorus compounds (3) represented by the following general formula (III).

[0101]

[0102] In equation (III), R 5 It refers to an unsubstituted or substituted aryl group having 6 to 20, preferably 6 to 12, carbon atoms, or an alkyl group having 1 to 20, preferably 1 to 12 carbon atoms.

[0103] In phosphorus compound (3) of general formula (III) used for phosphorus compound component (B), R 5 The C6-C20 aryl or C1-C20 alkyl groups may be unsubstituted or substituted with one or more substituents. These substituents may include, for example, carboxyl, alkyl, hydroxyl, and amino groups.

[0104] Phosphorus compounds (3) of general formula (III) include, for example, monomethyl phosphate, monoethyl phosphate, monotrimethyl phosphate, monobutyl phosphate, monohexyl phosphate, monoheptyl phosphate, monooctyl phosphate, monononyl phosphate, monodecyl phosphate, monododecyl phosphate, monolauryl phosphate, monooleyl phosphate, monotetradecyl phosphate, monophenyl phosphate, monobenzyl phosphate, mono(4-dodecyl)phenyl phosphate, mono(4-methylphenyl) phosphate, mono(4-ethylphenyl) phosphate, mono(4-propylphenyl) phosphate, mono(4-dodecylphenyl) phosphate, monotolyl phosphate, monoxyl phosphate, monobiphenyl phosphate, mononaphthalene phosphate, and monoanthracite phosphate, etc., which can be used alone or in mixtures of two or more, such as a mixture of monoalkyl phosphate and monoaryl phosphate. When the above-mentioned phosphorus compounds are used in a mixture of two or more, the ratio of monoalkyl phosphate is preferably 50% or more, more preferably 90% or more, and particularly preferably 100%.

[0105] <Preparation of Catalyst Particles>

[0106] When preparing the catalyst particles of the present invention from titanium compound component (A) and phosphorus compound component (B), the process is carried out, for example, by adjusting the reaction initiation temperature of an alkanediol solution containing titanium compound component (A) to 25-35°C, preferably 27-33°C, adding dropwise a mixture of component (B) consisting of at least one phosphorus compound (3) of formula (III) and a solvent to the mixture, and heating the reaction system at a temperature of 50°C to 200°C, preferably 70-150°C, for 1 minute to 4 hours, preferably 30 minutes to 2 hours.

[0107] There are no particular restrictions on the reaction pressure; it can be carried out under pressure (0.1–0.5 MPa), atmospheric pressure, or depressurization (0.001–0.1 MPa), but it is usually carried out under atmospheric pressure.

[0108] Furthermore, there are no particular limitations on the solvent used for the phosphorus compound component (B) of formula (III) in the above-mentioned catalyst particle preparation reaction, as long as it can dissolve at least a portion of the phosphorus compound component (B). For example, it is preferable to use a solvent composed of at least one selected from ethanol, ethylene glycol, trimethylene glycol, tetramethylene glycol, benzene, and xylene. It is particularly preferable to use a compound as a solvent that is the same as the diol component constituting the desired final polyester.

[0109] In the catalyst particle preparation reaction, the mixing ratio of titanium compound component (A) to phosphorus compound component (B) in the reaction system is determined by the molar amount (m) of titanium compound component (A) in the reaction product of the titanium compound component (A) and phosphorus compound component contained in the obtained catalyst particles. TiMolar amount of phosphorus atoms converted between phosphorus compound component (B) and phosphorus compound component (B) (m P The reaction molar ratio m Ti :m P The ratio is set to a range of 1:1 to 1:3, preferably 1:1 to 1:2.

[0110] The reaction product of titanium compound component (A) and phosphorus compound component (B) can be separated from the reaction system by means of centrifugation precipitation or filtration and used as a catalyst for polyester manufacturing without purification. Alternatively, the separated reaction product can be purified by recrystallization using a recrystallizing agent such as acetone, methanol, and / or water, and the purified product can be used as a catalyst. Alternatively, the reaction mixture containing the reaction product can be used directly as a mixture containing the catalyst without separating the reaction product from the reaction system.

[0111] In one embodiment of the catalyst particles for polyester manufacturing of the present invention, a reaction product of a titanium compound component (A) consisting of at least one titanium compound (1) of the above formula (I) (where k represents 1), namely a tetraalkyl titanate, and a phosphorus compound component (B) consisting of at least one phosphorus compound of the above formula (III) is used as a catalyst.

[0112] In the catalyst particles described above, the reaction product of a titanium compound component consisting of at least one titanium compound from formula (I) (where k = 1) and a phosphorus compound component consisting of at least one phosphorus compound from formula (III) contains a compound represented by (IV) below. Wherein, R in formula (IV) 6 and R 7 Each of the bases is independently derived from the above titanium compound (1) as R. 1 R 2 R 3 and R 4 Any one or more alkyl groups having 2 to 10 carbon atoms, or R from the above-mentioned phosphorus compound (3) 5 Alkyl groups having 6 to 12 carbon atoms.

[0113]

[0114] The catalyst particles containing titanium / phosphorus compounds represented by formula (IV) have high catalytic activity. Polyesters made using them have good color tone and good transparency (low haze) after molding, and have practically sufficient polymer properties.

[0115] In the catalyst particles for polyester manufacturing of the present invention, the titanium / phosphorus compound of the above general formula (IV) preferably contains 50% by mass or more, more preferably 70% by mass or more.

[0116] <Methods for manufacturing polyester>

[0117] In the polyester manufacturing method of the present invention, a polymerization starting material composed of at least one selected from alkyl diol esters of aromatic dicarboxylic acids and their oligomers (oligomers) undergoes polycondensation in the presence of the catalyst particles described above. At this time, the titanium atom-equivalent millimole amount of the catalyst particles used is preferably set to 2-40%, more preferably 3-35%, and even more preferably 4-30%, relative to the total millimole amount of aromatic dicarboxylic acid components contained in the polymerization starting material. If the titanium atom-equivalent millimole amount of the catalyst particles is less than 2%, the catalyst's promoting effect on the polycondensation reaction of the polymerization starting material may be insufficient, resulting in insufficient polyester manufacturing efficiency and the inability to obtain a polyester with the desired degree of polymerization. Furthermore, if the titanium atom-equivalent millimole amount of the catalyst particles exceeds 40%, the resulting polyester may sometimes have an insufficient hue (b-value) and a yellowish tint, reducing its practicality.

[0118] For the alkyl glycol ester of the aromatic dicarboxylic acid used as the polymerization starting material in the polyester manufacturing method of the present invention, the aromatic dicarboxylic acid is preferably selected from terephthalic acid, isophthalic acid, naphthalic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid and β-hydroxyethoxybenzoic acid, and is particularly more preferred to use terephthalic acid and naphthalic acid.

[0119] In addition, the aforementioned alkyl diols are preferably selected from ethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol, and hexamethylene glycol.

[0120] There are no restrictions on the methods for manufacturing the above-mentioned aromatic dicarboxylic acid alkyl glycol esters and / or their oligomers. They are usually manufactured by heating an aromatic dicarboxylic acid or its ester-forming derivative with an alkyl glycol or its ester-forming derivative.

[0121] For example, ethylene glycol terephthalate and / or its oligomers used as raw materials for polyethylene terephthalate are manufactured by directly esterifying terephthalic acid with ethylene glycol, or by transesterifying lower alkyl terephthalate with ethylene glycol, or by adding terephthalic acid to ethylene oxide.

[0122] In addition, propylene glycol terephthalate and / or oligomers of terephthalic acid, which are raw materials for polytrimethylene glycol terephthalate, are manufactured by directly esterifying terephthalic acid with trimethylene glycol, or by transesterifying lower alkyl terephthalic acid with trimethylene glycol, or by adding terephthalic acid with tetramethylene oxide.

[0123] It should be noted that the above-mentioned aromatic dicarboxylic acid alkyl glycol esters and / or their oligomers may contain other dicarboxylic acid esters that can copolymerize with them as additional components. The amount added is within the range that does not substantially impair the effect of the method of the present invention. Specifically, based on the total molar amount of the acid components, it is within the range of 10 mol% or less, preferably 5 mol% or less.

[0124] The aforementioned copolymerizable additional components are preferably selected from one or more aliphatic and alicyclic dicarboxylic acids, such as adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid, and hydroxycarboxylic acids, such as β-hydroxyethoxybenzoic acid and p-hydroxybenzoic acid, and one or more esters or anhydrides of aliphatic, alicyclic, and aromatic diols, such as alkyldiols having two or more carbon atoms, 1,4-cyclohexanediol, neopentyl glycol, bisphenol A, and bisphenol S, and polyoxyalkylene glycols. The aforementioned additional ester components can be used alone or in combination of two or more. The copolymerization amount is preferably within the range described above.

[0125] It should be noted that when using terephthalic acid and / or dimethyl terephthalate as starting materials, based on the total mass of the acid components constituting the polyester, recycled dimethyl terephthalate obtained by depolymerizing polyethylene terephthalate or recycled terephthalic acid obtained by hydrolyzing polyethylene terephthalate can also be used, accounting for more than 70% by mass. In this case, the target polyethylene terephthalate is preferably polyethylene terephthalate, and from the viewpoint of efficient resource utilization, it is particularly preferred to use recycled PET bottles, recycled fiber products, recycled polyester film products, and polymer scraps generated in the manufacturing process of these products as raw material sources for polyester manufacturing.

[0126] Here, there are no particular limitations on the method for depolymerizing recovered poly(alkyl terephthalate) to obtain dimethyl terephthalate; any method known to date can be used. For example, after depolymerizing the recovered poly(alkyl terephthalate) using ethylene glycol, the depolymerization product is subjected to transesterification using a lower alcohol, such as methanol. The reaction mixture is purified to recover the lower alkyl ester of terephthalic acid, which is then subjected to transesterification using an alkyl glycol. The resulting phthalic acid / alkyl glycol ester is then polycondensed to obtain a polyester. Furthermore, there are no particular limitations on the method for recovering terephthalic acid from the recovered dimethyl terephthalate; any method known to date can be used. For example, after recovering dimethyl terephthalate from the reaction mixture obtained from the transesterification reaction by recrystallization and / or distillation, terephthalic acid can be recovered by hydrolyzing it with water under high temperature and pressure. The terephthalic acid obtained by this method preferably contains impurities in the following proportions: 4-carboxybenzaldehyde, p-toluic acid, benzoic acid, and dimethyl hydroxyterephthalate, with a combined content of less than 1 ppm. Furthermore, the content of monomethyl terephthalate is preferably in the range of 1 to 5000 ppm. The terephthalic acid recovered by the above method can be directly esterified with an alkyl diol, and the resulting ester can be polycondensed to produce a polyester.

[0127] In the polyester manufacturing method of the present invention, the timing of adding catalyst particles to the polymerization starting material can be any stage before the start of the polycondensation reaction of the aromatic dicarboxylic acid alkyl glycol ester and / or its oligomers, and the method of addition is not limited. For example, the aromatic dicarboxylic acid alkyl glycol ester can be prepared, and a solution or slurry of the catalyst can be added to the reaction system to induce the polycondensation reaction, or the catalyst solution or slurry can be added to the reaction system together with the starting material or after its addition during the preparation of the aromatic dicarboxylic acid alkyl glycol ester.

[0128] There are no particular limitations on the polyester manufacturing reaction conditions in the method of this invention. Generally, the polycondensation reaction is preferably carried out at a temperature of 230 to 320°C, under normal pressure or reduced pressure (0.1 to 0.1 MPa), or a combination of these conditions, for 15 to 300 minutes.

[0129] In the method of this invention, a reaction stabilizer, such as trimethyl phosphate, can be added to the reaction system at any stage of polyester manufacturing as needed. Furthermore, one or more of the following additives can be added to the reaction system as needed: antioxidant, ultraviolet absorber, flame retardant, fluorescent whitening agent, matting agent, colorant, defoamer, and others. Particularly preferred is that the polyester contains an antioxidant comprising at least one hindered phenolic compound, and its content is preferably less than 1% by mass relative to the mass of the polyester. If its content exceeds 1% by mass, the thermal degradation of the antioxidant itself may sometimes lead to adverse conditions that degrade the quality of the obtained product.

[0130] The hindered phenolic compound used as an antioxidant in the polyester of the present invention can be selected from pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro[5,5]undecane, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenyl)butane, etc. The following are selected from: (-hydroxybenzyl)benzene, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzene)isophthalic acid, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylidene-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], etc. It is also preferable to use these hindered phenolic antioxidants in combination with thioether-based secondary antioxidants.

[0131] There are no particular restrictions on the method of adding the above-mentioned hindered phenolic antioxidants to polyesters. It is preferred to add them at any stage between the end of the transesterification reaction or esterification reaction and the end of the polymerization reaction.

[0132] Furthermore, to fine-tune the hue of the obtained polyester, a color-fixing agent composed of one or more organic blue pigments selected from azo, triphenylmethane, quinoline, anthraquinone, and phthalocyanine pigments, as well as inorganic blue pigments, can be added to the reaction system during the polyester manufacturing stage. It should be noted that the manufacturing method of the present invention does not require the use of inorganic blue pigments such as cobalt, which reduce the melt heat stability of the polyester, as a color-fixing agent. Therefore, the polyester obtained by the method of the present invention substantially does not contain cobalt.

[0133] The intrinsic viscosity of the polyester used in this invention is not limited, but is preferably in the range of 0.3 to 0.9. If the intrinsic viscosity is within this range, melt molding is easy, and the resulting molded article has high strength. A more preferred range for the aforementioned intrinsic viscosity is 0.4 to 0.8, and particularly preferably 0.5 to 0.7.

[0134] The intrinsic viscosity of the polyester is determined by dissolving the test polyester in o-chlorophenol and measuring it at 35°C. It should be noted that polyesters obtained through solid-state polycondensation are generally used for bottles, etc., and therefore, the polyester has an intrinsic viscosity of 0.70 to 0.90. The content of the cyclic trimer of the above-mentioned aromatic dicarboxylic acid and alkyl diol ester is preferably 0.5 wt% or less, and the content of acetaldehyde is preferably 5 ppm or less. The above-mentioned cyclic trimer includes alkyl terephthalate esters, such as ethylene terephthalate, propylene terephthalate, butylene terephthalate, and hexanediol terephthalate, as well as alkyl dinaphthalate esters, such as ethylene dinaphthalate, propylene terephthalate, butylene terephthalate, and hexanediol terephthalate.

[0135] In the polyester hue (L value and b value) obtained using the catalyst particles of the present invention, the L value is preferably 70 or higher, more preferably 75 or higher, even more preferably 77 or higher, and particularly preferably 78 or higher. The b value is preferably in the range of -5.0 to 5.0, more preferably in the range of -4.0 to 4.0, even more preferably in the range of -3.0 to 3.0, and particularly preferably in the range of -2.0 to 2.0. If it is within the above range, the polyester hue is excellent and therefore preferred.

[0136] Furthermore, the haze value of the 3mm thickness of the molded sheet obtained by molding the polyester using the catalyst particles of the present invention is preferably 5.0 or less, more preferably 4.5 or less, even more preferably 4.0 or less, and particularly preferably 3.8 or less. If it is within the above range, the polyester exhibits excellent transparency, and is therefore preferred.

[0137] Example

[0138] The invention will be described in more detail through the following embodiments, but the scope of the invention is not limited to these embodiments. It should be noted that the following measurements were performed in the embodiments.

[0139] (1) Particle size of catalyst particles

[0140] The particle size of the catalyst particles used in polyester manufacturing is determined by feeding catalyst particles dissolved in ethylene glycol into a laser diffraction particle size distribution measuring device ("SALD-2000" manufactured by Shimadzu Corporation).

[0141] (2) Limiting viscosity (IV)

[0142] The limiting viscosity (IV) of polyester polymer is calculated by dissolving 0.6 g of polyester sample in 50 mL of o-chlorophenol and measuring the viscosity of the solution at 35 °C using an Ubbelohde viscometer.

[0143] (3) Diethylene glycol (DEG) content

[0144] DEG content was determined by decomposing polyester particles using hydrazine hydrate and then subjecting the decomposed product to gas chromatography (GC-2014 manufactured by Shimadzu Corporation).

[0145] (4) Number of terminal carboxyl groups

[0146] The number of terminal carboxyl groups in a polyester polymer is determined by dissolving the polyester polymer in benzyl alcohol and titrating it with sodium hydroxide, then converting the titration value into a value per unit weight.

[0147] (5) Hue (L value and b value)

[0148] After treating the polyester polymer at 140°C in a nitrogen atmosphere for 1 hour, 65g of the polymer was filled into a cylindrical container with a diameter of 5cm and a height of 5cm. The L value and b value were measured using a Nippon Denko Corporation colorimeter "ZE6000". The L value represents lightness; the higher the value, the higher the lightness of the sample. The higher the b value, the greater the degree of yellow coloration of the sample.

[0149] (6) Titanium and phosphorus concentration analysis

[0150] The concentrations of titanium and phosphorus atoms in the catalyst were determined as follows: a dry catalyst sample was placed on a scanning electron microscope (SEM, Hitachi High-Tech Corporation S-3500N) and measured using an energy dispersive X-ray microanalyzer (XMA, Horiba Corporation EMAX-7000) connected to it.

[0151] The concentration of catalyst metal in the polyester polymer was determined by heating granular samples to 90°C on an aluminum plate, then forming them into planar test samples using a compression press, and using a Rigaku Corporation ZSXPrimusII X-ray fluorescence spectrometer.

[0152] (7) Haze measurement of the molded plate

[0153] The polyester polymer was dried for at least 5 hours at 110°C, atmospheric pressure, and nitrogen flow using a shelf-type dryer. It was then fed into an injection molding machine (NPX7-1F, manufactured by Nissei Resin Kogyo Co., Ltd.) and injection molded into a 30mm long, 30mm wide, and 3mm thick sheet under the following conditions: barrel temperature 280°C, screw speed 105rpm, mold cooling temperature 15°C, and cycle time 30 seconds. The haze of the molded sheet was measured using a NDH2000 turbidimeter (manufactured by Nippon Denshoku Kogyo Co., Ltd.). Lower haze indicates higher transparency.

[0154] [Example 1]

[0155] <Preparation of Catalyst Particles>

[0156] 85.3 g of ethylene glycol was added to a 300 mL three-necked flask capable of heating and stirring the contents, and heated to 100 °C while stirring. Next, 14.7 g of monobutyl phosphate was added and stirred to obtain a clear solution. This solution will be referred to hereafter as "solution P".

[0157] 285.04 g of ethylene glycol and 0.29 g of acetic acid were added to a 300 mL three-necked flask capable of heating and stirring the contents, and the mixture was stirred at 30 °C. Next, the mixture was heated to 50 °C, and 2.05 g of tetrabutyl titanate was slowly added to prepare an ethylene glycol solution of the titanium compound. This solution will be referred to as "Solution T1" below.

[0158] The T1 solution was cooled to 30°C and maintained at 30°C. 12.62 g of P solution was then slowly added. The reaction mixture was then heated to 120°C and stirred for 2 hours to allow the phosphorus and titanium compounds to react. After the reaction was complete, the mixture was cooled to room temperature, and the particle size was measured. The average particle size was D. 10 =1.8μm, D 50 =3.9μm, D 90 =7.9μm. Hereinafter, this catalyst-containing slurry will be referred to as "TP1 catalyst slurry".

[0159] The titanium and phosphorus atom concentrations of the catalyst particles in the TP-1 catalyst slurry were determined as follows. The TP-1 catalyst slurry was filtered through a 5 μm pore size filter, washed with water, and dried to obtain a solid. Analysis of the obtained solid using an XMA apparatus linked to a SEM revealed a titanium concentration of 11%, a phosphorus concentration of 15%, and a phosphorus-to-titanium atom molar ratio of 2.

[0160] Polymerization of Polyester

[0161] Under nitrogen atmosphere, 246℃, and normal pressure, 17.3 kg of high-purity terephthalic acid and 9.2 kg of ethylene glycol were mixed in a reactor containing 26.4 kg of ethylene glycol-terephthalic acid oligomers. The prepared slurry was fed at a certain rate and stirred for 3 hours for esterification.

[0162] 26.4 kg of the ester oligomer obtained from the esterification reaction was placed in a polycondensation reaction tank, along with 206 g of TP1 catalyst slurry and 0.016 g of blue colorant (CISolvent Blue 45). While stirring the reaction solution, the reaction temperature was gradually increased from 255°C to 280°C, and the reaction pressure was gradually reduced from atmospheric pressure to 60 Pa. Water and ethylene glycol produced by the polycondensation reaction of the ester oligomer were removed from the system, and the polycondensation reaction of the ester oligomer continued. The progress of the polycondensation reaction was monitored by changing the load on the stirring blades, and the reaction was terminated when the generated polyester reached the desired degree of polymerization. The polycondensation reaction time was 151 minutes. Subsequently, the reaction mixture in the system was continuously extruded into bundles from the nozzle, cooled, solidified, and cut to obtain granular particles with a particle size of approximately 3 mm. Hereinafter, this polyethylene terephthalate will be referred to as "PET1".

[0163] The obtained PET1 had an IV value of 0.545 and a diethylene glycol (DEG) content of 1.2 wt%. The particle hue was L value 78 and b value -1.1. The catalyst metal concentrations were 10 ppm (4 mmol%) of titanium and 15 ppm (9 mmol%) of phosphorus.

[0164] <Molding Evaluation>

[0165] Using the obtained PET1, a 3mm thick molded sheet was formed using the following method. PET1 (1kg) was dried for at least 5 hours at 110°C, atmospheric pressure, and nitrogen flow using a shelf-type dryer. Next, the dried PET1 was fed into an injection molding machine (NPX7-1F, manufactured by Nissei Resin Kogyo Co., Ltd.), and injection molded into a 30mm long, 30mm wide, and 3mm thick sheet under the following conditions: barrel temperature 280°C, screw speed 105rpm, mold cooling temperature 15°C, and cycle time 30 seconds. The haze of the obtained molded sheet was measured. The haze was 3.74%. The measurement results are shown in Table 1.

[0166] [Example 2]

[0167] <Preparation of Catalyst Particles>

[0168] The preparation of solution P was carried out in the same manner as in Example 1.

[0169] 285.04 g of ethylene glycol and 0.29 g of acetic acid were added to a 300 mL three-necked flask capable of heating and stirring the contents, and the mixture was stirred at 30 °C. 2.05 g of tetrabutyl titanate was then slowly added to prepare an ethylene glycol solution of the titanium compound. This solution will be referred to as "Solution T2" below.

[0170] The T2 solution was maintained at 30°C, and 12.62 g of P solution was slowly added. The reaction mixture was then heated to 120°C and stirred for 2 hours to allow the phosphorus and titanium compounds to react. After the reaction was complete, the mixture was cooled to room temperature, and the particle size was measured. The average particle size was D. 10 =1.9μm, D 50 =4.6μm, D 90 =14.4μm. Hereinafter, this catalyst-containing slurry will be referred to as "TP2 catalyst slurry".

[0171] The concentrations of titanium and phosphorus atoms in the catalyst particles of the TP-2 catalyst slurry were determined in the same manner as in Example 1, with a titanium concentration of 9%, a phosphorus concentration of 13%, and a molar ratio of phosphorus atoms to titanium atoms of 2.

[0172] Polymerization of Polyester

[0173] The polymerization was carried out in the same manner as in Example 1, except that TP2 catalyst slurry was used instead of TP1 catalyst slurry. The polymerization reaction time was 152 minutes. Hereinafter, the resulting polyethylene terephthalate will be referred to as "PET2". PET2 has an IV value of 0.547 and a diethylene glycol (DEG) content of 1.0 wt%. The hue of the particles is L value of 80 and b value of 1.4. The catalyst metal concentrations are titanium = 9 ppm (4 mmol%) and phosphorus = 15 ppm (9 mmol%).

[0174] <Molding Evaluation>

[0175] Except that PET2 was used instead of PET1, the same molding process as in Example 1 was used to form a 3 mm thick molded plate, and the haze was measured. The haze was 3.71%. The measurement results are shown in Table 1.

[0176] [Comparative Example 1]

[0177] <Preparation of Catalyst Particles>

[0178] The preparation of solution P was carried out in the same manner as in Example 1.

[0179] 285.04 g of ethylene glycol and 0.29 g of acetic acid were added to a 300 mL three-necked flask capable of heating and stirring the contents, and the mixture was stirred at 50 °C. 2.05 g of tetrabutyl titanate was then slowly added to prepare an ethylene glycol solution of the titanium compound. This solution will be referred to as "Solution T3" below.

[0180] The T3 solution was maintained at 50°C, and 12.62 g of P solution was slowly added. The reaction mixture was then heated to 120°C and stirred for 2 hours to allow the phosphorus and titanium compounds to react. After the reaction was complete, the mixture was cooled to room temperature, and the particle size was measured. The average particle size was D. 10 =1.3μm, D50 =4.9μm, D 90 =20.4μm. Hereinafter, this catalyst-containing slurry will be referred to as "TP3 catalyst slurry".

[0181] The concentrations of titanium and phosphorus atoms in the catalyst particles of the TP-3 catalyst slurry were determined in the same manner as in Example 1, with a titanium concentration of 10%, a phosphorus concentration of 14%, and a molar ratio of phosphorus atoms to titanium atoms of 2.

[0182] Polymerization of Polyester

[0183] The polymerization was carried out in the same manner as in Example 1, except that TP3 catalyst slurry was used instead of TP1 catalyst slurry. The polymerization reaction time was 182 minutes. Hereinafter, the resulting polyethylene terephthalate will be referred to as "PET3". PET3 has an IV value of 0.545 and a diethylene glycol (DEG) content of 0.9 wt%. The particle hue is L value of 79 and b value of 2.2. The catalyst metal concentrations are titanium = 10 ppm (4 mmol%) and phosphorus = 15 ppm (9 mmol%).

[0184] <Molding Evaluation>

[0185] Except that PET3 was used instead of PET1, the same molding process as in Example 1 was used to form a 3 mm thick molded plate, and the haze was measured. The haze was 5.09%. The measurement results are shown in Table 1.

[0186] [Comparative Example 2]

[0187] <Preparation of Catalyst Particles>

[0188] The preparation of solution P was carried out in the same manner as in Example 1.

[0189] 285.04 g of ethylene glycol and 0.29 g of acetic acid were added to a 300 mL three-necked flask capable of heating and stirring the contents, and the mixture was stirred at 120 °C. Then, 2.05 g of tetrabutyl titanate was slowly added to prepare an ethylene glycol solution of the titanium compound. This solution will be referred to as "Solution T4" below.

[0190] The T4 solution was maintained at 120°C, and 12.62 g of P solution was slowly added. The reaction mixture was then stirred for 2 hours to allow the phosphorus and titanium compounds to react. After the reaction was complete, the mixture was cooled to room temperature, and the particle size was measured. The average particle size was D. 10 =2.7μm, D 50 =11.5μm, D 90 =31.2μm. Hereinafter, this catalyst-containing slurry will be referred to as "TP4 catalyst slurry".

[0191] The concentrations of titanium and phosphorus atoms in the catalyst particles of the TP-4 catalyst slurry were determined in the same manner as in Example 1, with a titanium concentration of 9%, a phosphorus concentration of 13%, and a molar ratio of phosphorus atoms to titanium atoms of 2.

[0192] Polymerization of Polyester

[0193] The polymerization was carried out in the same manner as in Example 1, except that TP4 catalyst slurry was used instead of TP1 catalyst slurry. The polymerization reaction time was 114 minutes. Hereinafter, the resulting polyethylene terephthalate will be referred to as "PET4". PET4 has an IV value of 0.557 and a diethylene glycol (DEG) content of 0.9 wt%. The hue of the particles is L value of 79 and b value of -1.1. The catalyst metal concentrations are titanium = 11 ppm (4 mmol%) and phosphorus = 15 ppm (9 mmol%).

[0194] <Molding Evaluation>

[0195] Except that PET4 was used instead of PET1, the same molding process as in Example 1 was used to form a 3 mm thick molded plate, and the haze was measured. The haze was 4.36%. The measurement results are shown in Table 1.

[0196]

[0197] As can be clearly confirmed from Table 1, the polyester obtained using the titanium / phosphorus reaction compound catalyst described in Examples 1-2 of the present invention has lower haze and better transparency after molding compared with the polyester obtained using the titanium / phosphorus reaction compound catalyst described in Comparative Examples 1-2.

[0198] Industrial availability

[0199] The catalyst particles for polyester manufacturing of the present invention and the method for manufacturing polyester using the same can provide polyester resins with excellent transparency (low haze) after molding, and have excellent practical usefulness.

Claims

1. A catalyst particle for polyester manufacturing, comprising the reaction product of a titanium compound component (A) and a phosphorus compound component (B), The reaction product of the titanium compound component (A) and the phosphorus compound component (B) is generated by adjusting the initial reaction temperature of the alkanediol solution containing the titanium compound component (A) to 25-35°C, adding dropwise a mixture of phosphorus compound (3) represented by formula (III) and solvent to the mixture, and heating the reaction system at a temperature of 50°C-200°C for 1 minute to 4 hours. Particle size D 50 Below 10.0 μm, and Particle size D 90 Below 20.0 μm Particle size D 90 / Particle size D 10 Below 10.0; The titanium compound component (A) is composed of at least one titanium compound (1) and titanium compound (2) represented by the following general formula (I), wherein the titanium compound (2) is obtained by reacting the titanium compound (1) of the following general formula (I) with an aromatic polycarboxylic acid or its anhydride represented by the following general formula (II). in, In equation (I), R 1 R 2 R 3 and R 4 Each of these terms independently represents an alkyl group having 2 to 10 carbon atoms, where k represents an integer from 1 to 3, and when k is 2 or 3, it represents 2 or 3 R atoms. 2 base and R 3 Each base can be the same as or different from the others. In equation (II), m represents an integer from 2 to 4; The phosphorus compound component (B) consists of at least one of the phosphorus compounds (3) represented by the following general formula (III). In equation (III), R 5 It refers to an unsubstituted or substituted aryl group having 6 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.

2. The catalyst particles for polyester manufacturing according to claim 1, wherein, In the reaction product of the titanium compound component (A) and the phosphorus compound component (B), the molar amount (m) of titanium atoms in the titanium compound component (A) is... Ti The molar amount of phosphorus atoms converted to the phosphorus compound component (B) (m P The reaction molar ratio (m) Ti / m P (The ratio is in the range of 1:1 to 1:3.) 3. The catalyst particles for polyester manufacturing according to claim 1 or 2, wherein, The titanium compound (1) of formula (I) is selected from tetraalkyl titanate, octaalkyl tritiate, and hexaalkyl ditiate.

4. The catalyst particles for polyester manufacturing according to claim 1 or 2, wherein, The aromatic polycarboxylic acid or its anhydride of formula (II) is selected from phthalic acid, trimellitic acid, triphenyl sulfide and pyromellitic acid or their anhydrides.

5. The catalyst particles for polyester manufacturing according to claim 1 or 2, wherein, The titanium compound (2) is the reaction product of the titanium compound (1) of formula (I) and the aromatic polycarboxylic acid or its anhydride of formula (II) in a molar ratio of 2:1 to 2:

5.

6. The catalyst particles for polyester manufacturing according to claim 1 or 2, wherein, The phosphorus compound (3) of formula (III) is selected from at least one of the following: monomethyl phosphate, monoethyl phosphate, monotrimethyl phosphate, monobutyl phosphate, monohexyl phosphate, monoheptyl phosphate, monooctyl phosphate, monononyl phosphate, monodecyl phosphate, monododecyl phosphate, monolauryl phosphate, monooleyl phosphate, monotetradecyl phosphate, monophenyl phosphate, monobenzyl phosphate, mono(4-dodecyl)phenyl phosphate, mono(4-methylphenyl) phosphate, mono(4-ethylphenyl) phosphate, mono(4-propylphenyl) phosphate, mono(4-dodecylphenyl) phosphate, monotolyl phosphate, monoxyl phosphate, monobiphenyl phosphate, mononaphthalene phosphate, and monoanthracite phosphate.

7. The catalyst particles for polyester manufacturing according to claim 1 or 2, comprising a reaction product of a titanium compound component (A) consisting of at least one titanium compound of formula (I) and a phosphorus compound component (B) consisting of at least one phosphorus compound (3) of formula (III), wherein k in formula (I) represents 1.

8. The catalyst particles for polyester manufacturing according to claim 7, wherein, The reaction product of a titanium compound component (A) composed of at least one titanium compound of formula (I) and a phosphorus compound component (B) composed of at least one phosphorus compound (3) of formula (III) comprises a compound represented by formula (IV), where k in formula (I) represents 1. In the formula, R 6 and R 7 Each can be independently represented as an alkyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms.

9. A method for manufacturing a polyester, comprising feeding a polymerization starting material composed of at least one of an ester selected from aromatic dicarboxylic acids and alkyl diols and their oligomers into a polycondensation reaction in the presence of catalyst particles for polyester manufacturing as described in any one of claims 1 to 8.

10. The method for manufacturing polyester according to claim 9, wherein, The amount of titanium atoms in the catalyst is 2 to 40% relative to the total millimoles of the aromatic dicarboxylic acid components contained in the polymerization starting material.

11. The method for manufacturing polyester according to claim 9 or 10, wherein, The aromatic dicarboxylic acid is selected from terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyl dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenylmethane dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenoxyethane dicarboxylic acid, and β-hydroxyethoxybenzoic acid.

12. The method for manufacturing polyester according to claim 11, wherein, The terephthalic acid is obtained by depolymerizing poly(alkyl terephthalate) and hydrolyzing the resulting dimethyl terephthalate.

13. The method for manufacturing polyester according to claim 9 or 10, wherein, The aromatic dicarboxylic acid and alkyl glycol ester is an ester of terephthalic acid and alkyl glycol, which is obtained by depolymerizing poly(alkyl terephthalate) alkyl glycol and then subjecting the resulting dimethyl terephthalate to an alkyl glycol transesterification reaction.

14. The method for manufacturing polyester according to claim 12, wherein, The poly(terephthalic acid) diol supplied for the depolymerization is discarded poly(terephthalic acid) diol molded material and / or polymer scraps recovered during the manufacturing process of poly(terephthalic acid) diol.

15. The method for manufacturing polyester according to claim 9 or 10, wherein, The alkyl glycol is selected from ethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol, and hexamethylene glycol.

16. The method for manufacturing polyester according to claim 9 or 10, wherein, The polycondensation reaction is carried out at a temperature of 230–320°C.

17. A polyester manufactured by the method according to any one of claims 9 to 16; The product further contains an antioxidant comprising at least one hindered phenolic compound in an amount exceeding 0% by mass and less than 1% by mass relative to the mass of the polyester.

18. The polyester according to claim 17, having an intrinsic viscosity of 0.30 to 0.

90. The content of the cyclic trimer of the aromatic dicarboxylic acid and the alkanediol ester is less than 0.50% by mass, and The acetaldehyde content is below 5 ppm.

19. A molded article comprising the polyester of claim 17 or 18.

20. The molded article according to claim 19, selected from bottles, sheets, thermoformed containers and injection-molded articles.

21. A polyester fiber obtained by melting a resin raw material containing the polyester of claim 17 or 18, extruding the melt into a fibrous form, and then solidifying it.

22. A polyester film is obtained by melting a resin raw material containing the polyester of claim 17 or 18, extruding the melt into a sheet and solidifying it, and stretching the resulting unstretched film in a biaxial direction.

Images