Catalysts, processes for their preparation and use, copolyesters and processes for their preparation

Abstract

This invention relates to the field of catalysis, and discloses a catalyst, its preparation method and application, and a copolyester and its preparation method. The catalyst has a structure as shown in Formula (I). The polyester prepared by this catalyst has a low zero-shear viscosity, facilitating subsequent processing, and the catalyst has high catalytic activity, resulting in a low content of oligomers as a byproduct in the prepared polyester. Formula (I).

Description

Technical Field

[0001] This invention relates to the field of catalysis, specifically to a catalyst, its preparation method, and its applications. Furthermore, this invention also relates to a method for preparing a copolyester using the catalyst, and the copolyester obtained by the catalyst. Background Technology

[0002] Polyethylene terephthalate (PET) is widely used in various fields due to its excellent mechanical properties, good light transmittance, strong gas barrier properties, and ease of processing. However, conventional PET has insufficient light transmittance and impact resistance, and it is difficult to meet high-temperature operating conditions.

[0003] To improve the heat resistance of PET, the industry mainly adds monomers with larger molecular structures, such as 2,2,4,4-tetramethyl-1,3-cyclobutanediol and isosorbide. The glass transition temperature of copolyesters modified with these macromonomers is increased, even exceeding 100℃.

[0004] CN107955142A discloses a method for preparing polyester containing isosorbide. By improving the catalyst formulation, lowering the reaction temperature, reducing monomer decomposition, and increasing the residual proportion of isosorbide monomer, which is difficult to participate in the reaction, in the final polymer. However, the activity of titanium catalysts is difficult to control, which can easily lead to a large number of by-products.

[0005] CN1675282A discloses a method for preparing a light-colored copolyester of ethylene glycol, isosorbide, and dimethyl terephthalate, wherein the catalyst used is selected from salts of Sb(III); salts of Ti(IV); acetates of Co(II); acetates of Sb(II); alkanoates of Co(II); alkanoates of Sb(III); oxides of Sb(III); oxides of Ge(IV); diol-soluble oxides of Sb(II), Sb(III), and Ge(IV); and Ti(OR)4, wherein R is an alkyl group with 2-12 carbon atoms, and b is -2 to +2 under the condition of no color correction additives. However, the prepared copolyester produces a large number of byproducts.

[0006] CN103819324A discloses a method for preparing a terephthalic acid-ethylene glycol-isosorbate copolyester polymer. Using germanium dioxide as a catalyst, and adding cobalt acetate and CIariant@RSB violet for color adjustment, the resulting product has a b-value less than 2. To increase the glass transition temperature, a large amount of rigid monomers is added to the product, resulting in a melt dynamic viscosity greater than 900 Pa·s, requiring a specially designed high-viscosity reactor to meet the requirements.

[0007] US8586701B2 discloses a method for preparing a copolyester based on 2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexanediethanol. However, the physicochemical properties of the modified monomers are less stable than those of conventional diols, and the reaction is prone to sublimation upon heating. Furthermore, the reaction with 1,4-cyclohexanediethanol easily produces a copolyester rich in poly(1,4-cyclohexanedimethyl terephthalate) segments with a high melting point and easy crystallization and precipitation, resulting in a significant decrease in the molecular weight and transparency of the product, making it difficult to directly obtain high molecular weight copolyesters. Summary of the Invention

[0008] The purpose of this invention is to overcome the problems of unsuitable polyester viscosity and excessive by-products in the prior art, and to provide a catalyst, its preparation method and application, and a copolyester and its preparation method. The polyester prepared by this catalyst has a low zero-shear viscosity, which is convenient for subsequent processing. Moreover, the catalyst has high catalytic activity, which results in a low content of oligomers as by-products in the prepared polyester.

[0009] To achieve the above objectives, a first aspect of the present invention provides a catalyst having a structure as shown in formula (I). Formula (I).

[0010] A second aspect of the present invention provides a method for preparing a catalyst, the method comprising: reacting germanium phosphate and an alkyl alcohol in a contact reaction I, wherein the alkyl alcohol is a C1-C25 alkyl alcohol.

[0011] A third aspect of the present invention provides a catalyst prepared by the above-described preparation method.

[0012] A fourth aspect of the present invention provides the application of the above-mentioned catalyst in the preparation of polyester.

[0013] A fifth aspect of the present invention provides a copolyester.

[0014] The sixth aspect of this invention provides a method for preparing a copolyester.

[0015] Through the above technical solution, the catalyst provided by this invention has high catalytic activity, enabling it to reduce the catalytic effect of byproducts during polyester preparation, thereby resulting in polyester with a lower oligomer content. Furthermore, it effectively reduces the dynamic viscosity of polyester, mitigating the problem of high-viscosity polyester sticking to the pan. Simultaneously, the polyester prepared using this catalyst exhibits good color and thermal stability. Attached Figure Description

[0016] Figure 1 The images are infrared spectra of standard germanium, standard phosphoric acid, germanium phosphate prepared in step S2 of Example 1, and the catalyst prepared in Example 1. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] As previously stated, a first aspect of the present invention provides a catalyst having a structure as shown in formula (I). Formula (I).

[0019] According to the present invention, the above structure can be detected by a combination of infrared, gas chromatography and ICP.

[0020] During their research, the inventors discovered that the catalyst provided by this invention possesses high catalytic activity. When used in the preparation of polyester, it effectively reduces the generation of byproducts such as oligomers, and also effectively reduces the zero-shear viscosity of polyester, minimizing the problem of high-viscosity polyester sticking to the pan and facilitating subsequent processing. The polyester prepared using this catalyst exhibits good thermal stability and color.

[0021] Preferably, the catalyst has a structure as shown in formula (IV). Formula (IV).

[0022] Preferably, the catalyst has the structural formula shown in formula (II) and / or formula (III). Formula (II); Formula (III); In this configuration, R1, R2, and R3 are each independently a C1-C25 alkylene group. The catalysts with these two structures exhibit better catalytic activity, further reducing the generation of byproducts such as oligomers during polyester preparation, while also lowering the zero-shear viscosity of the resulting polyester, facilitating subsequent applications.

[0023] According to the present invention, R1, R2, and R3 can each independently be a C1-C25 straight-chain alkylene and / or a C1-C25 branched alkylene, specifically methylene, hexane, propylene, butylene, pentylene, octylene, dodecylene, pentadecylene, heptadecanylene, octadecylene, eicosylene, or icosylene. Preferably, R1, R2, and R3 are each independently a C1-C25 straight-chain alkylene. During the research, it was found that limiting R1, R2, and R3 to a straight-chain structure can further reduce the oligomer content and zero-shear viscosity in the polyester produced using this catalyst, facilitating subsequent applications.

[0024] Preferably, R1, R2, and R3 are each independently C4-C25 alkylene groups. Studies have found that controlling R1, R2, or R3 within the aforementioned range results in a catalyst with higher catalytic activity, further reducing the generation of byproducts such as oligomers during polyester preparation and lowering the zero-shear viscosity of the polyester. Further preferably, considering the ability to further reduce the oligomer content and zero-shear viscosity in the subsequently obtained polyester, R1, R2, and R3 are each independently C15-C20 alkylene groups. More preferably, R1 and R2 are the same.

[0025] In a relatively preferred embodiment of the present invention, the catalyst has the structural formula shown in Formula (III). This catalyst exhibits high catalytic activity, and the polyester prepared using this catalyst has lower oligomer content and zero shear viscosity, facilitating subsequent applications.

[0026] A second aspect of the present invention provides a method for preparing a catalyst, the method comprising: subjecting germanium phosphate and an alkyl alcohol to a contact reaction I, wherein the alkyl alcohol is a C1-C25 alkyl alcohol.

[0027] The catalyst prepared by the above method has the structure shown in formula (I). During the research, it was found that the catalyst prepared by the above method exhibits high catalytic activity when used in the preparation of polyester, effectively reducing the generation of byproducts such as oligomers, and also reducing the dynamic viscosity of polyester, thus mitigating the problem of high-viscosity polyester sticking to the pan. The polyester prepared using this catalyst exhibits good thermal stability and color.

[0028] Preferably, the alkyl alcohol is a primary alcohol. Studies have found that catalysts prepared from primary alcohols have high catalytic activity, resulting in polyesters with low oligomer content and zero shear viscosity.

[0029] Preferably, the alkyl alcohol is a C4-C25 alkyl alcohol. The polyester prepared from the catalyst obtained by the above-mentioned alkyl alcohol preparation has a lower oligomer content and zero shear viscosity. Further preferably, considering the ability to further reduce the oligomer content and zero shear viscosity of the obtained polyester, the alkyl alcohol is a C15-C20 alkyl alcohol.

[0030] Preferably, the alkyl alcohol is an alkyl monohydric alcohol and / or an alkyl dihydric alcohol. Studies have found that catalysts prepared using alkyl monohydric alcohols and / or alkyl dihydric alcohols, with structures as shown in formula (II) and / or formula (III), exhibit higher catalytic activity, resulting in polyesters prepared using these catalysts having lower oligomer content and zero shear viscosity. From the perspective of further reducing the oligomer content and zero shear viscosity of the obtained polyester, preferably, the alkyl alcohol is an alkyl dihydric alcohol.

[0031] Preferably, the conditions for contact reaction I are at least: a temperature of 100-150°C and a time of 2-4 hours. The catalyst prepared under the above conditions exhibits high catalytic activity.

[0032] Preferably, the contact reaction I is carried out in a solvent. Carrying the contact reaction I in a solvent allows the reactants to have a better reaction effect. More preferably, the polar solvent is water.

[0033] Preferably, the molar ratio of germanium phosphate to the alkyl alcohol is 1:2-5.

[0034] Germanium phosphate is commercially available or can be prepared. Preferably, the preparation method of germanium phosphate includes: reacting sodium germanate and phosphoric acid in a contact reaction II. This method can prepare germanium phosphate and improve the reaction efficiency between germanium phosphate and alkyl alcohols.

[0035] Sodium germanate is commercially available or can be prepared. Preferably, the preparation method of sodium germanate includes: carrying out a contact reaction III with sodium carbonate, sodium peroxide, and metallic germanium. This method can prepare sodium germanate and improve the reaction efficiency between sodium germanate and phosphoric acid.

[0036] Preferably, the conditions for contact reaction II include at least a time of 0.5-2 hours. Under these conditions, sodium germanate and phosphoric acid exhibit good reaction performance.

[0037] Preferably, the molar ratio of sodium germanate to phosphoric acid is 1:1.8-2.2. More preferably, it is 1:2.

[0038] Preferably, the conditions for contact reaction III include at least: a temperature of 450-550°C and a time of 2-4 hours. Under these conditions, sodium carbonate, sodium peroxide, and metallic germanium exhibit good reaction performance.

[0039] Preferably, the molar ratio of sodium carbonate, sodium peroxide and metallic germanium is 1:1.5-2.5:0.8-1.2.

[0040] The method further includes separating water from the product obtained by the contact reaction I. The separation method can be distillation, drying, or other methods.

[0041] A third aspect of this invention provides a catalyst prepared by the above-described method. The catalyst prepared by the above method exhibits good catalytic performance and has wide applications in polyester preparation. The polyester prepared by the above catalyst has low oligomer content and low zero-shear viscosity, facilitating subsequent applications.

[0042] A fourth aspect of the present invention provides the application of the above-described catalyst in the preparation of polyester. The polyester prepared using this catalyst exhibits lower zero-shear viscosity, better hue, and lower oligomer content.

[0043] Preferably, the polyester is an aliphatic-aromatic polyester. This aliphatic-aromatic polyester may contain structural units formed from aliphatic diols and structural units formed from aromatic diacids.

[0044] A fifth aspect of the present invention provides a copolyester having the structure shown in formula (I). Formula (I).

[0045] Studies have found that the copolyester with the structure shown in formula (I) has a lower zero-shear viscosity and a lower oligomer content.

[0046] Preferably, in the copolyester, the content of the structure represented by formula (I), calculated as germanium, is 50-500 μg / g, which can be 50 μg / g, 100 μg / g, 150 μg / g, 200 μg / g, 250 μg / g, 300 μg / g, 350 μg / g, 400 μg / g, 450 μg / g, 500 μg / g, or any value between these values. Studies have found that controlling the content of the structure represented by formula (I) in the copolyester within the above range results in a lower zero-shear viscosity and oligomer content. Considering the potential for further reduction in the zero-shear viscosity and oligomer content of the copolyester, the content of the structure represented by formula (I), calculated as germanium, in the copolyester is 220-300 μg / g. Preferably, the zero-shear viscosity of the copolyester is less than or equal to 720 Pa·s, and the oligomer content is less than or equal to 0.61%. More preferably, the copolyester has a zero-shear viscosity of 615-685 Pa·s and an oligomer content of 0.25-0.4%.

[0047] Preferably, the copolyester has a Tg of 88-120℃, a color value L of 56-69, and a b value of -2 to 7.7. More preferably, the copolyester has a color value L of 66-68 and a b value of -2.2 to 0.

[0048] The intrinsic viscosity, L-value, and b-value were all obtained according to the national standard GB17931-2018; Tg was obtained according to GB / T 14190-2017; molecular weight distribution index, oligomer content, and number-average molecular weight were obtained according to GB / T 36214.1-2018; and dynamic zero-shear viscosity was obtained according to JY / T 0590-2020 standard.

[0049] According to this invention, oligomers refer to polymers with a molecular weight of less than 2000, such as dimers, trimers, and tetramers, produced by side reactions during polyester polymerization. The oligomer content refers to the percentage of the oligomer's mass to the mass of the copolyester.

[0050] The sixth aspect of the present invention provides a method for preparing a copolyester, the method comprising: in the presence of a catalyst, subjecting a polyol monomer and a carbonyl-containing monomer to a contact reaction IV, wherein the carbonyl-containing monomer is a polyacid and / or a polyester, and the catalyst is the catalyst provided above.

[0051] During their research, the inventors discovered that using the aforementioned catalyst during the preparation of copolyesters can effectively reduce the formation of oligomers, a byproduct of polyester production. Furthermore, the resulting polyester exhibits a low zero-shear viscosity, facilitating subsequent processing and utilization.

[0052] Preferably, the polybasic acid is an aromatic dibasic acid, and the polybasic acid ester is an aromatic dibasic acid ester; the polyol contains a chain diol. Under the above conditions, the catalyst exhibits better catalytic performance.

[0053] From the perspective of further reducing the zero-shear viscosity and oligomer content of the copolyester, it is further preferred that the polyol also contains a cyclic diol, preferably isosorbide and / or 1,4-cyclohexanediethanol. More preferably, the cyclic diol is isosorbide and 1,4-cyclohexanediethanol. Even more preferably, the molar ratio of isosorbide to 1,4-cyclohexanediethanol is 1:1.5-2:1.

[0054] Preferably, the molar ratio of the chain diol to the cyclic diol is 2:1 to 10:1. The polyester prepared under the above conditions has a low zero-shear viscosity and low oligomer content.

[0055] Preferably, the amount of catalyst, calculated in germanium, is 50-500 μg / g based on the theoretical yield of the copolyester. Controlling the catalyst dosage within this range further reduces the zero-shear viscosity and oligomer content of the copolyester. More preferably, considering the ability to further reduce the zero-shear viscosity and oligomer content of the copolyester, the amount of catalyst, calculated in germanium, is 220-300 μg / g based on the theoretical yield of the copolyester. Preferably, the contact reaction IV includes a first-stage contact reaction and a second-stage contact reaction.

[0056] Preferably, the first stage of the contact reaction includes at least a temperature of 220-260°C and an initial pressure less than or equal to 0.25 MPa; the second stage of the contact reaction includes at least a temperature of 265-275°C and a vacuum degree less than or equal to 80 Pa. Under these conditions, the polyol monomer and the carbonyl-containing monomer exhibit good reaction performance, and the amount of oligomers formed is relatively small.

[0057] Preferably, the preparation method further includes: before the contact reaction IV, mixing a polyol monomer, a carbonyl-containing monomer, and an auxiliary agent, wherein the auxiliary agent is selected from at least one of ether inhibitors, antioxidants, and colorants. Through the synergistic effect between the above-mentioned auxiliary agent, catalyst, polyol monomer, and carbonyl-containing monomer, the hue of the polyester can be further improved and the zero-shear viscosity of the polyester can be reduced. Further preferably, considering the ability to further improve the hue of the polyester and reduce its zero-shear viscosity, the amount of the auxiliary agent used is 500-5000 μg / g, based on the theoretical yield of the copolyester.

[0058] Preferably, the ether inhibitor is an alkali metal acetate inhibitor and / or an alkaline earth metal acetate inhibitor. More preferably, the alkali metal acetate inhibitor is selected from at least one of sodium acetate, lithium acetate, and potassium histidine; the alkaline earth metal acetate inhibitor is magnesium acetate and / or calcium acetate. More preferably, the amount of the ether inhibitor used is 5-100 μg / g, based on the theoretical yield of the copolyester.

[0059] Preferably, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 1076, antioxidant 1500, antioxidant 425, antioxidant 168, and antioxidant PEPQ, and more preferably antioxidant 1010 and antioxidant PEPQ. More preferably, the mass ratio of antioxidant PEPQ to antioxidant 1010 is 1-4:1. More preferably, the amount of antioxidant used is 500-5000 μg / g, based on the theoretical yield of the copolyester.

[0060] Preferably, the colorant is an organic red or cobalt acetate.

[0061] Preferably, the additives may not include the colorant, and the colorant is added to the reaction product after the contact reaction IV is completed.

[0062] Preferably, the additives are ether inhibitors, antioxidants, and colorants. The combination of these additives can further improve the hue of the polyester and reduce its zero-shear viscosity. More preferably, the mass ratio of the ether inhibitor, the antioxidant, and the colorant is 1:0.03-38:25-500.

[0063] The present invention will be described in detail below through examples. In the following examples, the intrinsic viscosity, L value, and b value were obtained according to the national standard GB17931-2018; Tg was obtained according to GB / T 14190-2017; the molecular weight distribution index, oligomer content, and number-average molecular weight were obtained according to GB / T 36214.1-2018; and the dynamic zero-shear viscosity was obtained according to the standard JY / T0590-2020.

[0064] Example 1-1 S1. Add 3 mol of sodium carbonate, 6 mol of sodium peroxide, and 3 mol of metallic germanium to a crucible. React at 500°C under nitrogen protection for 3 hours to obtain sodium germanate. The reaction is as follows: Ge+2Na2O2+Na2CO3=Na2GeO3+CO2↑+2Na2O.

[0065] S2. Sodium germanate was placed in an Erlenmeyer flask, and 6 mol of phosphoric acid was added. The reaction was carried out for 1 hour to obtain an aqueous solution containing germanium phosphate. The reaction is as follows: 3Na2GeO3+6H3PO4=Ge3(PO4)4+2(Na)3PO4+9H2O.

[0066] S3. Then, 3 mol of 1-heptadecanool (CAS No.: 1454-85-9) was added to an aqueous solution containing germanium phosphate, and the mixture was reacted at 100℃ for 4 hours. The product was then separated from water by distillation and dried to obtain catalyst-1. The reaction is as follows: 2Ge3(PO4)4 + 3CH3(CH2) 15 CH2OH=3Ge2(PO4)2C 34 H 64 +2H3PO4.

[0067] Infrared spectroscopy was performed on germanium standard, phosphoric acid standard, germanium phosphate prepared in step S2, and the catalyst prepared in step S3. The resulting spectra are shown below. Figure 1 As shown. From Figure 1 As can be seen from the data, the infrared absorption peak of the PO bond in phosphoric acid is located at 1003.58 cm⁻¹. -1The infrared absorption peak of the PO bond in germanium phosphate is located at 993.69 cm⁻¹. -1 At this location, the PO bond elution peak in germanium phosphate has shifted compared to that in phosphoric acid. This may be because the PO bond elution peak in germanium phosphate is affected by the binding with germanium. The infrared absorption peak of the PO bond in the catalyst is located at 1000.14 cm⁻¹. -1 At this location, the shift in the peak position of the PO bond is smaller compared to that in germanium phosphate, which may be due to the influence of alkyl alcohols on PO. The infrared peaks appearing in germanium phosphate are also present in the catalyst, indicating the presence of germanium-oxygen bonds in the catalyst. Furthermore, the catalyst provided by this invention exhibits a peak at 2917 cm⁻¹. -1 and 2850cm -1 The presence of stretching vibrations of CH on saturated C atoms and the absence of stretching vibration peaks of OH bonds indicate that the hydroxyl groups on the alkyl alcohol have combined with germanium phosphate to form PO, meaning that a chemical reaction has occurred between germanium phosphate and the alkyl alcohol.

[0068] Examples 1-2 S1. Add 3 mol of sodium carbonate, 4.5 mol of sodium peroxide and 2.4 mol of metallic germanium to a crucible, and react at 450 °C under nitrogen protection for 4 h to obtain sodium germanate.

[0069] S2. Sodium germanate was placed in an Erlenmeyer flask, and 6 mol of phosphoric acid was added and reacted for 2 hours to obtain an aqueous solution containing germanium phosphate.

[0070] S3. Then, add 3 mol of pentadecanool (CAS No.: 629-76-5) to the aqueous solution containing germanium phosphate, react at 150℃ for 2 h, and then separate the water from the product by distillation and dry to obtain catalyst-2.

[0071] Examples 1-3 S1. Add 3 mol of sodium carbonate, 7.5 mol of sodium peroxide and 3.6 mol of metallic germanium to a crucible, and react at 550 °C under nitrogen protection for 2 h to obtain sodium germanate.

[0072] S2. Place sodium germanate in an Erlenmeyer flask, add 6 mol of phosphoric acid and react for 0.5 h to obtain an aqueous solution containing germanium phosphate.

[0073] S3. Add 3 mol of 1-octadecanool (CAS No.: 112-92-5) to an aqueous solution containing germanium phosphate, react at 130℃ for 3 h, and then separate the water from the product by distillation and dry to obtain catalyst-3.

[0074] Examples 1-4 The catalyst was prepared according to the method described in Examples 1-2, except that in step S3, 1-pentadecanol (CAS No.: 629-76-5) was replaced with 1,15-pentadecanediol (CAS No.: 14722-40-8), and the resulting catalyst was designated as catalyst-4.

[0075] Examples 1-5 The catalyst was prepared according to the method described in Examples 1-3, except that in step S3, 1-octadecaneol (CAS No.: 112-92-5) was replaced with 1,18-octadecanediol (CAS No.: 3155-43-9), and the resulting catalyst was designated as catalyst-5.

[0076] Examples 1-6 The catalyst was prepared according to the method described in Examples 1-3, except that in step S3, 1-octadecaneol (CAS No.: 112-92-5) was replaced with 1,12-octadecanediol (CAS No.: 2726-73-0), and the resulting catalyst was designated as catalyst-6.

[0077] Examples 1-7 The catalyst was prepared according to the method described in Examples 1-3, except that in step S3, 1-octadecanool (CAS No.: 112-92-5) was replaced with eicosanool (CAS No.: 629-96-9), and the resulting catalyst was designated as catalyst-7.

[0078] Examples 1-8 The catalyst was prepared according to the method described in Examples 1-2, except that in step S3, 1-pentadecanol (CAS No.: 629-76-5) was replaced with n-dodecanool (CAS No.: 112-53-8), and the resulting catalyst was designated as catalyst-8.

[0079] Examples 1-9 The catalyst was prepared according to the method described in Examples 1-2, except that in step S3, 1-pentadecanol (CAS No.: 629-76-5) was replaced with 2-dodecaneol (CAS No.: 10203-28-8), and the resulting catalyst was designated as catalyst-9.

[0080] Examples 1-10 The catalyst was prepared according to the method described in Examples 1-3, except that in step S3, 1-octadecanool (CAS No.: 112-92-5) was replaced with 1,20-eicosanediol (CAS No.: 7735-43-5), and the resulting catalyst was designated as catalyst-10.

[0081] Examples 1-11 The catalyst was prepared according to the method described in Examples 1-2, except that in step S3, 1-pentadecanol (CAS No.: 629-76-5) was replaced with 1,12-dodecanediol (CAS No.: 5675-51-4), and the resulting catalyst was designated as catalyst-11.

[0082] Examples 1-12 The catalyst was prepared according to the method described in Examples 1-2, except that in step S3, 1-pentadecanol (CAS No.: 629-76-5) was replaced with n-butanol, and the resulting catalyst was designated as catalyst-12.

[0083] Examples 1-13 The catalyst was prepared according to the method described in Examples 1-3, except that in step S3, 1-octadecanool (CAS No.: 112-92-5) was replaced with tetracosanool (CAS No.: 506-51-4), and the resulting catalyst was designated as catalyst-13.

[0084] Example 2-1 A slurry was prepared by mixing 350g of purified terephthalic acid, 182g of ethylene glycol, 48g of isosorbide, 98g of CHDM, 0.254g of catalyst-1, 0.04g of ether inhibitor potassium acetate, 0.075g of colorant cobalt acetate, 0.5g of antioxidant 1010, and 0.5g of antioxidant 425. This slurry was then added to a polymerization reactor, and esterification was carried out at 240℃ and an initial pressure of 0.25MPa. When the esterification liquid temperature reached 260℃ and the temperature at the top of the fractionation column was less than 120℃, the pressure in the polymerization reactor was reduced to atmospheric pressure, and esterification was completed. The reactor then entered a low-vacuum stage, and after 45 minutes, a high-vacuum stage was initiated, controlling the temperature at 270℃ and the vacuum degree to be less than 80Pa. After 2 hours, the reaction was stopped, and the reaction product was extruded from the bottom of the polymerization reactor, cooled, and granulated to obtain a copolyester.

[0085] Example 2-2 A slurry was prepared by mixing 350g of purified terephthalic acid, 182g of ethylene glycol, 48g of isosorbide, 98g of CHDM, 2.54g of catalyst-1, 0.002g of ether inhibitor magnesium acetate, 0.075g of colorant cobalt acetate, 0.5g of antioxidant 1010, and 0.5g of antioxidant 425. This slurry was then added to a polymerization reactor, and esterification was carried out at 220℃ and an initial pressure of 0.25MPa. When the esterification liquid temperature reached 260℃ and the temperature at the top of the fractionation column was less than 120℃, the pressure in the polymerization reactor was reduced to atmospheric pressure, and esterification was completed. The reactor then entered a low-vacuum stage, and after 45 minutes, a high-vacuum stage was initiated, controlling the temperature at 275℃ and the vacuum degree to be less than 80Pa. After 2 hours, the reaction was stopped, and the reaction product was extruded from the bottom of the polymerization reactor, cooled, and granulated to obtain a copolyester.

[0086] Example 2-3 A slurry was prepared by mixing 350g of purified terephthalic acid, 122g of ethylene glycol, 96g of isosorbide, 98g of CHDM, 1.61g of catalyst-1, 0.02g of ether inhibitor calcium acetate, 0.257mg of redness agent, 0.514mg of blueness agent, 0.25g of antioxidant 1076, and 2.0g of antioxidant 168. This slurry was then added to a polymerization reactor. Esterification was carried out at 255℃ and an initial pressure of 0.25MPa. When the esterification liquid temperature reached 260℃ and the temperature at the top of the fractionation column was less than 120℃, the pressure in the polymerization reactor was reduced to atmospheric pressure, ending the esterification. The reactor then entered a low-vacuum stage, followed by a high-vacuum stage after 45 minutes, maintaining a temperature of 265℃ and a vacuum degree less than 80Pa. The reaction was stopped after 2 hours. The reaction product was extruded from the bottom of the polymerization reactor, cooled, and granulated to obtain a copolyester.

[0087] Examples 2-4 A slurry was prepared by mixing 350g of purified terephthalic acid, 30g of ethylene glycol, 144g of isosorbide, 120g of CHDM, 1.24g of catalyst-1, 0.02g of ether inhibitor lithium acetate, 0.278mg of redness agent, 0.556mg of blueness agent, 0.25g of antioxidant 1500, and 0.5g of antioxidant PEPQ. This slurry was then added to a polymerization reactor. Esterification was carried out at 255℃ and an initial pressure of 0.25MPa. When the esterification liquid temperature reached 260℃ and the temperature at the top of the fractionation column was less than 120℃, the pressure in the polymerization reactor was reduced to atmospheric pressure, ending the esterification. The reactor then entered a low-vacuum stage, followed by a high-vacuum stage after 45 minutes, maintaining a temperature of 275℃ and a vacuum degree less than 80Pa. The reaction was stopped after 2 hours. The reaction product was extruded from the bottom of the polymerization reactor, cooled, and granulated to obtain a copolyester.

[0088] Examples 2-5 A slurry was prepared by mixing 350g of purified terephthalic acid, 30g of ethylene glycol, 96g of isosorbide, 98g of CHDM, 1.57g of catalyst-1, 0.02g of ether inhibitor sodium acetate, 0.257mg of redness agent, 0.514mg of blueness agent, 0.25g of antioxidant 1010, and 1.5g of antioxidant PEPQ. This slurry was then added to a polymerization reactor. Esterification was carried out at 255℃ and an initial pressure of 0.25MPa. When the esterification liquid temperature reached 260℃ and the temperature at the top of the fractionation column was less than 120℃, the pressure in the polymerization reactor was reduced to atmospheric pressure, ending the esterification. The reactor then entered a low-vacuum stage, followed by a high-vacuum stage after 45 minutes, maintaining a temperature of 275℃ and a vacuum degree less than 80Pa. The reaction was stopped after 2 hours. The reaction product was extruded from the bottom of the polymerization reactor, cooled, and granulated to obtain a copolyester.

[0089] Examples 2-6 The copolyester was prepared according to the method described in Example 2-1, except that the amount of catalyst-1 added was 0.508 g.

[0090] Examples 2-7 The copolyester was prepared according to the method described in Example 2-1, except that the amount of catalyst-1 added was 0.762 g.

[0091] Examples 2-8 The copolyester was prepared according to the method described in Example 2-1, except that the amount of catalyst-1 added was 1.778 g.

[0092] Examples 2-9 The copolyester was prepared according to the method described in Example 2-1, except that the amount of catalyst-1 added was 2.032 g.

[0093] Example 2-10 The copolyester was prepared according to the method described in Example 2-1, except that the amount of catalyst-1 added was 2.286 g.

[0094] Example 2-11 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-2, and the amount of catalyst-2 added, calculated in germanium, was 50 μg·g based on the theoretical yield of the polyester. -1 .

[0095] Example 2-12 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-3, and the amount of catalyst-3 added, calculated in germanium, was 50 μg∙g based on the theoretical yield of the polyester. -1 .

[0096] Example 2-13 The copolyester was prepared according to the method described in Example 2-1, except that catalyst 1 was replaced with catalyst 4, and the amount of catalyst 4 added, calculated in germanium, was 50 μg·g based on the theoretical yield of the polyester. -1 .

[0097] Example 2-14 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-5, and the amount of catalyst-5 added, calculated in germanium, was 50 μg·g based on the theoretical yield of the polyester. -1 .

[0098] Example 2-15 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-6, and the amount of catalyst-6 added, calculated in germanium, was 50 μg∙g based on the theoretical yield of the polyester. -1 .

[0099] Example 2-16 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-7, and the amount of catalyst-7 added, calculated in germanium, was 50 μg·g based on the theoretical yield of the polyester. -1 .

[0100] Example 2-17 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-8, and the amount of catalyst-8 added, calculated in germanium, was 50 μg·g based on the theoretical yield of the polyester. -1 .

[0101] Example 2-18 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-9, and the amount of catalyst-9 added, calculated in germanium, was 50 μg·g based on the theoretical yield of the polyester. -1 .

[0102] Example 2-19 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-10, and the amount of catalyst-10 added, calculated in germanium, was 50 μg∙g based on the theoretical yield of the polyester. -1 .

[0103] Example 2-20 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-11, and the amount of catalyst-11 added, calculated in germanium, was 50 μg∙g based on the theoretical yield of the polyester. -1 .

[0104] Example 2-21 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-12, and the amount of catalyst-12 added, calculated in germanium, was 50 μg·g based on the theoretical yield of the polyester. -1 .

[0105] Example 2-22 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with catalyst-13, and the amount of catalyst-13 added, calculated in germanium, was 50 μg∙g based on the theoretical yield of the polyester. -1 .

[0106] Example 2-23 The copolyester was prepared according to the method described in Example 2-1, except that the colorant cobalt acetate was not added.

[0107] Example 2-24 The copolyester was prepared according to the method described in Example 2-1, except that antioxidant 1010 and antioxidant 425 were not added.

[0108] Example 2-25 The copolyester was prepared according to the method described in Example 2-1, except that the ether inhibitor potassium acetate was not added.

[0109] Example 2-26 The copolyester was prepared according to the method described in Example 2-1, except that the ether inhibitor potassium acetate, the colorant cobalt acetate, antioxidant 1010 and antioxidant 425 were not added.

[0110] Comparative Example 2-1 Copolyesters were prepared according to the method described in Example 2-1, except that 0.254 g of catalyst-1 was replaced with 0.038 g of germanium dioxide.

[0111] Comparative Example 2-2 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with 0.084 g of germanium phosphate prepared in step S2 of Example 1-1.

[0112] Comparative Examples 2-3 The copolyester was prepared according to the method described in Example 2-1, except that catalyst-1 was replaced with 0.084 g of germanium phosphate prepared in step S2 of Example 1-1 and 0.171 g of heptadecanol (CAS No.: 1454-85-9).

[0113] The parameters of the copolyesters prepared in the examples and comparative examples are shown in Table 1.

[0114] Table 1

[0115] As can be seen from the results in Table 1, the copolyester prepared using the catalyst of the present invention has a lower oligomer content and a lower zero-shear viscosity, as well as a lower b-value and a better hue, which facilitates subsequent processing and application.

[0116] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A catalyst characterized in that, The catalyst has a structure as shown in formula (I). Formula (I).

2. The catalyst according to claim 1, characterized in that, The catalyst has the structural formula shown in formula (II) and / or formula (III). Formula (II); Formula (III); Among them, R1, R2 and R3 are each independently C1-C25 alkylene groups; Preferably, R1, R2, and R3 are all straight-chain alkylene groups; Preferably, R1, R2, and R3 are each independently a C4-C25 alkylene group; Preferably, R1, R2, and R3 are each independently a C15-C20 alkylene group; Preferably, R1 and R2 are the same.

3. A method for producing a catalyst, characterized by, The preparation method includes: reacting germanium phosphate and an alkyl alcohol in a contact reaction I, wherein the alkyl alcohol is a C1-C25 alkyl alcohol.

4. The production method according to claim 3, characterized by, The alkyl alcohol is a primary alcohol; Preferably, the alkyl alcohol is a C4-C25 alkyl alcohol, and more preferably a C15-C20 alkyl alcohol; Preferably, the alkyl alcohol is an alkyl monohydric alcohol and / or an alkyl dihydric alcohol, and more preferably an alkyl dihydric alcohol.

5. The production method according to claim 3 or 4, characterized by, Preferably, the method for preparing germanium phosphate includes: subjecting sodium germanate and phosphoric acid to a contact reaction II; Preferably, the method for preparing sodium germanate includes: subjecting sodium carbonate, sodium peroxide, and metallic germanium to a contact reaction III; Preferably, the conditions for contact reaction I are at least: temperature of 100-150℃ and time of 2-4h; the conditions for contact reaction II include at least: time of 0.5-2h; and the conditions for contact reaction III include at least: temperature of 450-550℃ and time of 2-4h. Preferably, the contact reaction I is carried out in a solvent; Preferably, the solvent is water.

6. The catalyst prepared by the method according to any one of claims 3 to 5.

7. The use of the catalyst according to any one of claims 1, 2 and 6 in the preparation of polyester; Preferably, the polyester is an aliphatic-aromatic polyester.

8. A copolyester characterized in that, The copolyester has the structure shown in formula (I). Formula (I); Preferably, in the copolyester, the content of the structure represented by formula (I) based on germanium is 50-500 μg / g, more preferably 220-300 μg / g; Preferably, the copolyester has a zero-shear viscosity of less than or equal to 720 Pa·s, more preferably 615-685 Pa·s; and an oligomer content of less than or equal to 0.62%, more preferably 0.25-0.4%. Preferably, the copolyester has a Tg of 88-120°C; a color value L of 56-69, more preferably 66-68; and a b value of -2 to 7.7, more preferably -2.2 to 0.

9. A process for the preparation of a copolyester characterized in that, The preparation method includes: in the presence of a catalyst, a contact reaction IV is carried out between a polyol monomer and a monomer containing a carbonyl group, wherein the monomer containing a carbonyl group is a polyacid and / or a polyester, and the catalyst is the catalyst described in any one of claims 1, 2 and 6; Preferably, the polybasic acid is an aromatic dibasic acid, the polybasic acid ester is an aromatic dibasic acid ester, and the polyol contains a chain diol; Preferably, the amount of catalyst used, calculated as germanium, is 50-500 μg / g, more preferably 220-300 μg / g, based on the theoretical yield of the copolyester.

10. The method of claim 9, wherein, The preparation method further includes: before the contact reaction IV, mixing a polyol monomer, a carbonyl monomer and an auxiliary agent, wherein the auxiliary agent is selected from at least one of an ether inhibitor, an antioxidant and a colorant; Preferably, the amount of the auxiliary agent used is 500-5000 μg / g, based on the theoretical yield of the copolyester; Preferably, the adjuvant is an ether inhibitor, an antioxidant, and a colorant; Preferably, the mass ratio of the ether inhibitor, the antioxidant, and the colorant is 1:0.03-38:25-500; Preferably, the contact reaction IV includes a first-stage contact reaction and a second-stage contact reaction; The first stage of the contact reaction includes at least a temperature of 220-260℃ and an initial pressure of less than or equal to 0.25MPa; the second stage of the contact reaction includes at least a temperature of 265-275℃ and a vacuum degree of less than or equal to 80Pa.

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