A hindered amine polymer material, and a preparation method and application thereof

Abstract

The application discloses a hindered amine polymer material and a preparation method and application thereof. The hindered amine polymer material is a modified polyester prepared through copolymerization of an oligomer polyester and a piperidine derivative, wherein the oligomer polyester is an oligomer PBT or an oligomer PET; or, the hindered amine polymer material is prepared through copolymerization of an oligomer polymer, wherein the oligomer polymer is prepared through polycondensation of terephthalic acid or dimethyl terephthalate, a diol and a piperidine derivative, wherein the diol is 1,4-butanediol or ethylene glycol; and the piperidine derivative has a structure shown in formula I or formula II. Compared with a conventional physically mixed polymer material, the weather resistance and migration resistance of the polymer material prepared through copolymerization are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to a hindered amine polymer material, its preparation method, and its application. Background Technology

[0002] In recent years, with the widespread application of polymer materials in various fields, enhancing their resistance to photoaging has become an important research topic. Hindered amine light stabilizers (HALS), as highly efficient light stabilizers, are widely used in polymer materials such as films, fibers, and coatings to prevent oxidation, degradation, and fading, thereby extending their service life.

[0003] Despite this, hindered amine light stabilizers still face several challenges in practical applications, particularly regarding heat resistance, extraction resistance, volatility, environmental impact, compatibility, and photostability. For example, traditional hindered amine light stabilizers are mostly non-reactive (such as light stabilizer 622 and light stabilizer 770), which can only be added to polymer materials through physical doping. Their compatibility with the resulting materials is poor, affecting their heat resistance and extraction resistance, thus limiting their application in high-temperature processing or special solvent environments. Furthermore, in the field of plastic products such as films or fibers, commonly available hindered amine light stabilizers exhibit relatively poor migration and extraction resistance, making them prone to migrating from plastic products and coming into contact with food or other substances, posing a potential hazard to the environment and human health.

[0004] Therefore, developing a hindered amine polymer material with good weather resistance is of great significance. Summary of the Invention

[0005] To overcome the aforementioned limitations of the prior art, this invention provides a hindered amine polymer material, its preparation method, and its applications. The hindered amine polymer material provided by this invention is a specially treated modified polyester containing structural segments of compounds shown in Formula I or Formula II. The compounds shown in Formula I or Formula II are reactive hindered amine light stabilizers that can be directly introduced into the polymer backbone via copolymerization, endowing the prepared polymer material with excellent resistance to photoaging and mechanical properties. This overcomes the problem in the prior art where the addition of hindered amine light stabilizers to polymer materials leads to a decrease in migration resistance and weather resistance due to physical migration or volatilization.

[0006] In a first aspect, the present invention provides a modified polyester, which is prepared by copolymerization of an oligopolyester with a piperidine derivative, wherein the oligopolyester is oligomeric PBT or oligomeric PET.

[0007] Alternatively, the modified polyester is prepared by copolymerization of the oligomer itself, and the oligomer is prepared by polycondensation of terephthalic acid or dimethyl terephthalate, diol and piperidine derivative, wherein the diol is 1,4-butanediol or ethylene glycol.

[0008] The piperidine derivative has the structure shown in Formula I or Formula II:

[0009]

[0010] Among them, R1, R3, and R4 are independently selected from: H, C1-C 10 alkyl;

[0011] R1', R3', and R4' are independently selected from: H, C1-C 10 alkyl;

[0012] R2 is selected from: H, C1-C 10 Alkyl, -O-(C1-C 10 Alkyl), -O-(C3-C) 10 cycloalkyl);

[0013] R2' is selected from: H, C1-C 10 Alkyl, -O-(C1-C 10 Alkyl), -O-(C3-C) 10 cycloalkyl);

[0014] n is an integer from 1 to 5, specifically 1, 2, 3, 4, 5;

[0015] The modified polyester has a molecular weight of 18,000-35,000, specifically 18,000, 19,000, 20,000, 21,000, 22,000, 23,000, 24,000, 25,000, 26,000, 27,000, 28,000, 29,000, 30,000, 31,000, 32,000, 33,000, 34,000, and 35,000.

[0016] Furthermore, the oligopolyester is prepared by polycondensation reaction of terephthalic acid or dimethyl terephthalate with a glycol (such as 1,4-butanediol or ethylene glycol). For example, the oligopoly PBT is prepared by polycondensation reaction of terephthalic acid or dimethyl terephthalate with 1,4-butanediol; the oligopoly PET is prepared by polycondensation reaction of terephthalic acid or dimethyl terephthalate with ethylene glycol.

[0017] Further, the molecular weight of the oligopolyester is 2000-8000, specifically such as 2000, 2200, 2400, 2600, 2800, 3000, 3200, 3400, 3600, 3800, 4000, 4200, 4400, 4600, 4800, 5000, 5200, 5400, 5600, 5800, 6000, 6200, 6400, 6600, 6800, 7000, 7200, 7400, 7600, 7800, and 8000. In some embodiments of the present invention, the molecular weight of the oligopolyester is 2500-5500.

[0018] Furthermore, the molecular weight of the oligomeric PBT is 3500-7000, preferably 5400-5500.

[0019] Furthermore, the molecular weight of the oligomeric PET is 2000-4000, preferably 2500-2600.

[0020] Further, the molecular weight of the oligomer is 2000-8000, specifically such as 2000, 2200, 2400, 2600, 2800, 3000, 3200, 3400, 3600, 3800, 4000, 4200, 4400, 4600, 4800, 5000, 5200, 5400, 5600, 5800, 6000, 6200, 6400, 6600, 6800, 7000, 7200, 7400, 7600, 7800, and 8000. In some embodiments of the present invention, the molecular weight of the oligomer is 3400-6100.

[0021] Furthermore, the modified polyester is a random copolymer.

[0022] Further, the oligopolyester is oligomeric PBT, and the molecular weight of the modified polyester is 20,000-35,000, preferably 24,000-26,000; or, the oligopolyester is oligomeric PET, and the molecular weight of the modified polyester is 18,000-28,000, preferably 20,000-22,000.

[0023] In some embodiments of the present invention, the molecular weight of the modified polyester is 20,000-26,000.

[0024] Furthermore, R1, R3, and R4 are independently selected from: H and C1-C6 alkyl groups.

[0025] Furthermore, R1', R3', and R4' are independently selected from: H and C1-C6 alkyl groups.

[0026] Furthermore, R2 is selected from: H, C1-C6 alkyl, -O-(C1-C6 alkyl), -O-(C3-C8 cycloalkyl).

[0027] Furthermore, R2' is selected from: H, C1-C6 alkyl, -O-(C1-C6 alkyl), -O-(C3-C8 cycloalkyl).

[0028] In some embodiments of the present invention, R1 is methyl.

[0029] In some embodiments of the present invention, R1' is methyl.

[0030] In some embodiments of the present invention, R2 is H, methyl, or...

[0031] In some embodiments of the present invention, R2' is H, methyl, or...

[0032] In some embodiments of the present invention, R3 is H or methyl.

[0033] In some embodiments of the present invention, R3' is H or methyl.

[0034] In some embodiments of the present invention, R4 is H or methyl.

[0035] In some embodiments of the present invention, R4' is H or methyl.

[0036] In some embodiments of the present invention, the piperidine derivative has the following structure:

[0037]

[0038] Further, the molar ratio of repeating units to piperidine derivatives in the oligopolyester is 1:(0.001-1), specifically such as 1:0.001, 1:0.002, 1:0.003, 1:0.004, 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, 1:0.01, 1:0.12, 1:0.14, 1:0.16, 1:0.18, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, preferably 1:(0.001-0.05). In some embodiments of the present invention, the molar ratio of repeating units to piperidine derivatives in the oligopolyester is 1:0.005.

[0039] Further, the molar ratio of terephthalic acid or dimethyl terephthalate to diol is 1:(1.5-6), specifically such as 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:4.6, 1:4.7, 1:4.8, 1:4.9, 1:5, 1:5.1, 1:5.2, 1:5.3, 1:5.4, 1:5.5, 1:5.6, 1:5.7, 1:5.8, 1:5.9, 1:6, preferably 1:(4.6-5.4) or 1:(4.5-5.3).

[0040] Further, the molar ratio of terephthalic acid or dimethyl terephthalate to piperidine derivative is 1:(0.001-1), specifically such as 1:0.001, 1:0.002, 1:0.003, 1:0.004, 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, 1:0.01, 1:0.12, 1:0.14, 1:0.16, 1:0.18, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, preferably 1:(0.001-0.05).

[0041] Further, the copolymerization reaction time is 1-12 hours, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 hours, preferably 2-8 hours. In some embodiments of the present invention, the copolymerization reaction time is 3-4 hours.

[0042] Further, the copolymerization reaction temperature is 0-280℃, specifically such as 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280℃, preferably 80-280℃ or 100-280℃. In some embodiments of the present invention, the copolymerization reaction temperature is 250-260℃.

[0043] Furthermore, the copolymerization reaction is carried out in a vacuum.

[0044] A second aspect of the present invention provides a method for preparing the modified polyester described in the first aspect of the present invention, the method comprising the following steps:

[0045] S1: Terephthalic acid or dimethyl terephthalate and glycol are mixed and subjected to polycondensation reaction to obtain oligomeric polyester;

[0046] S2: The obtained oligopolyester and piperidine derivative are mixed and copolymerized to obtain modified polyester;

[0047] Alternatively, the preparation method may include the following steps:

[0048] T1: Terephthalic acid or dimethyl terephthalate, diol and piperidine derivative are mixed and subjected to polycondensation reaction to obtain oligomer;

[0049] T2: The resulting oligomer is copolymerized to obtain a modified polyester.

[0050] Optionally, S3 or T3: the resulting modified polyester is extruded and granulated.

[0051] Further, S1 includes: mixing terephthalic acid or dimethyl terephthalate, glycol and catalyst, and carrying out a polycondensation reaction under heating conditions to obtain an oligomeric polyester.

[0052] Further, T1 includes: mixing terephthalic acid or dimethyl terephthalate, diol, piperidine derivative and catalyst, and carrying out a polycondensation reaction under heating conditions to obtain an oligomer.

[0053] Furthermore, the diol is 1,4-butanediol or ethylene glycol.

[0054] Furthermore, the catalyst is an organotitanium catalyst, including but not limited to tetraisopropyl titanate and tetrabutyl titanate.

[0055] Further, the molar ratio of terephthalic acid or dimethyl terephthalate to diol is 1:(1.5-6). In some embodiments of the present invention, the molar ratio of terephthalic acid to diol is 1:(4.6-5.4); the molar ratio of dimethyl terephthalate to diol is 1:(4.5-5.3).

[0056] Further, the mass of the catalyst is 0.01-1% of the mass of terephthalic acid or dimethyl terephthalate, specifically such as 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, or 1%.

[0057] Further, the molar ratio of terephthalic acid or dimethyl terephthalate and piperidine derivative is 1:(0.001-1), preferably 1:(0.001-0.05).

[0058] Furthermore, the polycondensation reaction time is 2-6 hours, such as 2, 3, 4, 5, or 6 hours, preferably 4-6 hours.

[0059] Furthermore, the temperature of the polycondensation reaction is 150-250℃, such as 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250℃, preferably 160-180℃ or 200-210℃.

[0060] In some embodiments of the present invention, S1 includes: mixing terephthalic acid, 1,4-butanediol and tetrabutyl titanate, and carrying out a polycondensation reaction at 160-180°C to obtain oligomeric PBT.

[0061] In some embodiments of the present invention, S1 includes: mixing terephthalic acid, ethylene glycol and tetrabutyl titanate, and carrying out a polycondensation reaction at 160-180°C to obtain oligomeric PET.

[0062] In some embodiments of the present invention, T1 includes: mixing dimethyl terephthalate, 1,4-butanediol, piperidine derivative and tetrabutyl titanate, and carrying out a polycondensation reaction at 200-210°C to obtain an oligomer.

[0063] In some embodiments of the present invention, T1 includes: mixing dimethyl terephthalate, ethylene glycol, piperidine derivative and tetrabutyl titanate, and carrying out a polycondensation reaction at 200-210°C to obtain an oligomer.

[0064] Further, S2 includes: mixing an oligomeric polyester and a piperidine derivative, and performing a copolymerization reaction under vacuum and heating conditions to obtain a modified polyester.

[0065] Further, T2 includes: copolymerizing an oligomer under vacuum and heating conditions to obtain a modified polyester.

[0066] Furthermore, the molar ratio of repeating units to piperidine derivatives in the oligopolyester is 1:(0.001-1), preferably 1:(0.001-0.05).

[0067] Furthermore, the copolymerization reaction time is 1-12 hours, preferably 2-8 hours, and more preferably 3-4 hours.

[0068] Furthermore, the temperature of the copolymerization reaction is 0-280℃, preferably 80-280℃ or 100-280℃, and more preferably 250-260℃.

[0069] In some embodiments of the present invention, S2 includes: mixing an oligomeric polyester (such as oligomeric PBT or oligomeric PET) and a piperidine derivative, and performing a copolymerization reaction under vacuum and at 250-260°C to obtain a modified polyester.

[0070] In some embodiments of the present invention, T2 includes: copolymerizing an oligomer in a vacuum at 250-260°C to obtain a modified polyester.

[0071] In a third aspect, the present invention provides the application of the modified polyester described in the first aspect or the modified polyester prepared by the preparation method described in the second aspect as a polymer material.

[0072] Furthermore, the polymer material is used directly and / or processed into various articles in various forms, including but not limited to plastics, fibers, resins, rubber, etc.

[0073] Furthermore, the polymer material may be a membrane, fiber, strip, profile, or molding composition, etc.

[0074] In a fourth aspect, the present invention provides a piperidine derivative as described in the first aspect of the present invention, having a structure shown in Formula I or Formula II.

[0075] A fifth aspect of the present invention provides a method for preparing the piperidine derivative described in the first or fourth aspect of the present invention, the method comprising the following steps: reacting a tetramethylpiperidineamine compound, a compound of formula III and / or a compound of formula IV in a solvent to obtain the piperidine derivative;

[0076] The tetramethylpiperidineamine compounds have the structure shown in formula V-1 or formula V-2:

[0077]

[0078] The compound represented by Formula III has the following structure:

[0079]

[0080] The compound represented by Formula IV has the following structure:

[0081]

[0082] Wherein, R1, R2, R3, R4, R1', R2', R3', R4', n, and piperidine derivatives have the definitions described in the first aspect of this invention.

[0083] Further, the solvent is selected from one or more of toluene, xylene, cyclohexane, octane, heptane, and tetrahydrofuran. In some embodiments of the present invention, the solvent is xylene.

[0084] In some embodiments of the present invention, the tetramethylpiperidineamine compound has the following structure:

[0085]

[0086] Furthermore, the compound shown in Formula III and the compound shown in Formula IV can be the same compound or different compounds.

[0087] In some embodiments of the present invention, the compound represented by Formula III has the following structure:

[0088]

[0089] In some embodiments of the present invention, the compound represented by Formula IV has the following structure:

[0090]

[0091] Furthermore, when the tetramethylpiperidineamine compound reacts only with the compound shown in Formula III, the molar ratio of the tetramethylpiperidineamine compound to the compound shown in Formula III is 1:(2-5), specifically 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, preferably 1:(2-2.3).

[0092] Furthermore, when the tetramethylpiperidineamine compound reacts only with the compound shown in Formula IV, the molar ratio of the tetramethylpiperidineamine compound to the compound shown in Formula IV is 1:(2-5), specifically such as 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, preferably 1:(2-2.3).

[0093] Furthermore, when the tetramethylpiperidineamine compound reacts with the compounds shown in Formula III and Formula IV, the molar ratio of the tetramethylpiperidineamine compound to the compounds shown in Formula III and Formula IV is 1:(2-5), specifically 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, preferably 1:(2-2.3).

[0094] Furthermore, the reaction temperature is 20-120℃, specifically 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120℃, preferably 60-80℃.

[0095] Furthermore, the reaction time is 6-24 hours, specifically 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 hours, preferably 8-12 hours.

[0096] Furthermore, the reaction is carried out in an inert gas (such as nitrogen).

[0097] In some embodiments of the present invention, the preparation method includes the following steps: under nitrogen protection, a tetramethylpiperidineamine compound is dissolved in a solvent (such as xylene), the temperature is raised to 50-60°C, the compound shown in Formula III and / or the compound shown in Formula IV is added, and the reaction is carried out at 60-80°C for 8-12 hours to obtain the piperidine derivative.

[0098] A sixth aspect of the present invention provides the application of a piperidine derivative as described in the first or fourth aspect of the present invention, or a piperidine derivative prepared by the preparation method described in the fifth aspect, as an additive for polymer materials.

[0099] Furthermore, the additive may be a light stabilizer, a heat stabilizer, or an antioxidant, etc.

[0100] Furthermore, the polymer material has the definition described in the third aspect of the present invention.

[0101] The present invention has the following beneficial effects:

[0102] (1) The compounds shown in Formula I or Formula II provided by this invention are reactive hindered amine light stabilizers. Because their structures contain ester groups, they can directly bond with polymer molecular chains. This not only enhances the compatibility and adhesion between polymer molecular chains but also effectively reduces migration in organic solvents, thereby obtaining polymer materials with excellent weather resistance and migration resistance. Compared with polymer materials prepared by conventional physical mixing methods, the polymer materials prepared by copolymerization in this invention exhibit significantly improved light stability and solvent migration resistance.

[0103] (2) The preparation process provided by the present invention is simple, has a high yield, and is low-carbon and environmentally friendly. Detailed Implementation

[0104] Unless otherwise defined, all scientific and technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0105] The term "alkyl" refers to a straight-chain or branched hydrocarbon radical that does not contain unsaturated bonds and is connected to the rest of the molecule by single bonds. Typical alkyl groups contain 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, preferably 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, n-hexyl, isohexyl, etc.

[0106] The term "cycloalkyl" refers to alicyclic hydrocarbons, such as those containing 1 to 4 monocyclic and / or fused rings, containing 3 to 18 carbon atoms, preferably 3 to 10 (e.g., 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or adamantyl.

[0107] The term "polybutylene terephthalate," also known as PBT, is typically prepared by the polycondensation reaction of terephthalic acid or dimethyl terephthalate with 1,4-butanediol. The structure of its repeating unit is shown below: Where n represents the degree of polymerization. In this paper, the degree of polymerization of PBT is approximately 20-35 (specifically 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35).

[0108] The term "polyethylene terephthalate," also known as PET, is typically prepared by the polycondensation reaction of terephthalic acid or dimethyl terephthalate with ethylene glycol. Its repeating unit structure is shown below: Where n represents the degree of polymerization. In this paper, the degree of polymerization of PET is approximately 10-20 (specifically 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20).

[0109] All raw materials and reagents used in the following examples are commercially available products.

[0110] All publications, patents, and published patent specifications cited in this article are incorporated herein in their entirety through citation.

[0111] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0112] Preparation Example 1:

[0113] Ingredient 1-1:

[0114] Raw materials 1-2:

[0115] Product I-1:

[0116] In a nitrogen atmosphere, 1 mol of raw material 1-1 was dissolved in 600 mL of xylene, heated to 50 °C, and 2.05 mol of raw material 1-2 was slowly added over a period of 6 h. After the droplet reaction was stopped, the temperature was raised to 80 °C and the reaction continued for 12 h. Excess raw material 1-2 was removed, and the product was desolvated to obtain the target product I-1.

[0117] Molecular weight: 345;

[0118] Yield: 91.8%.

[0119] Preparation Example 2:

[0120] Raw material 2-1:

[0121] Raw material 2-2:

[0122] Ingredients 2-3:

[0123] Product I-2:

[0124] In a nitrogen atmosphere, 1 mol of raw material 2-1 was dissolved in 1000 mL of xylene, the temperature was raised to 60 °C, and 1.15 mol of raw material 2-2 was slowly added over 3 h. Then, 1.15 mol of raw material 2-3 was slowly added over 3 h. After the droplet was stopped, the temperature was raised to 80 °C and the reaction continued for 8 h. Excess raw materials 2-2 and 2-3 were removed, and the product was desolvated to obtain the target product I-2.

[0125] Molecular weight: 548;

[0126] Yield: 93.6%.

[0127] Preparation Example 3:

[0128] Ingredient 3-1:

[0129] Raw material 3-2:

[0130] Product I-3:

[0131] In a nitrogen atmosphere, 1 mol of raw material 3-1 was dissolved in 1200 mL of xylene, heated to 60 °C, and 2.3 mol of raw material 3-2 was slowly added over 8 h. After the droplet reaction was stopped, the temperature was raised to 80 °C and the reaction continued for another 8 h. Excess raw material 3-2 was removed, and the product was desolvated to obtain the target product I-3.

[0132] Molecular weight: 451;

[0133] Yield: 94.7%.

[0134] Preparation Example 4:

[0135] 500g of terephthalic acid, 1300g of 1,4-butanediol, and 0.05% by mass of tetrabutyl titanate (calculated as terephthalic acid) were reacted at 180°C for 6 hours to complete esterification, yielding oligomeric PBT.

[0136] Molecular weight: 5432.

[0137] Preparation Example 5:

[0138] 500g of terephthalic acid, 1000g of ethylene glycol, and 0.05% by mass of tetrabutyl titanate (calculated as terephthalic acid) were reacted at 180°C for 6 hours. Esterification was completed to obtain oligomeric PET.

[0139] Molecular weight: 2564.

[0140] Preparation Example 6:

[0141] 600g of dimethyl terephthalate, 1300g of 1,4-butanediol, 48g of compound I-1 (prepared from Preparation Example 1) and 0.05% by mass of tetrabutyl titanate (based on dimethyl terephthalate) were reacted at 200°C for 6h. After transesterification, oligomeric PBT-I was obtained.

[0142] Molecular weight: 6032.

[0143] Preparation Example 7:

[0144] 600g of dimethyl terephthalate, 1000g of ethylene glycol, 85g of compound I-3 (prepared from Preparation Example 3) and 0.05% by mass of tetrabutyl titanate (based on dimethyl terephthalate) were reacted at 210°C for 6h. After transesterification, oligomeric PET-I was obtained.

[0145] Molecular weight: 3451.

[0146] Comparative preparation example 1:

[0147] Product II-1 was prepared by the preparation method of Examples 1 and 18 in US5506286A.

[0148] Product II-1:

[0149] Molecular weight: 613.

[0150] Comparative preparation example 2:

[0151] Product II-2 was prepared by the preparation method of Example 1 in patent document CN116621770A.

[0152] Product II-2:

[0153] Molecular weight: 564.

[0154] Example 1:

[0155] 1. Preparation of standard sample 1# of copolymerized PBT

[0156] Weigh 100 wt% of the standard polymer (i.e., the oligomeric PBT of Preparation Example 4), and continue the copolymerization reaction at 260 °C for 3 h in a vacuum environment. Then, extrude and granulate to prepare copolymerized PBT standard sample 1#.

[0157] Molecular weight: 25645.

[0158] 2. Preparation of standard sample 2# of copolymerized PBT

[0159] Weigh 1 mol of standard polymer (i.e., oligomeric PBT of Preparation Example 4, based on repeating units in PBT) and 0.005 mol of functional additive I-1 (prepared from Preparation Example 1). Continue copolymerization reaction at 260°C for 3 h under vacuum. Then extrude and granulate to prepare copolymerized PBT standard sample 2#.

[0160] Molecular weight: 25986.

[0161] 3. Preparation of standard sample 3# of copolymerized PBT

[0162] Weigh 1 mol of standard polymer (i.e., oligomeric PBT of Preparation Example 4, based on repeating units in PBT) and 0.005 mol of functional additive I-2 (prepared from Preparation Example 2). Continue copolymerization reaction at 260°C for 3 h under vacuum. Then extrude and granulate to prepare copolymerized PBT standard sample 3#.

[0163] Molecular weight: 24987.

[0164] 4. Preparation of standard sample 4# of copolymerized PBT

[0165] Weigh 1 mol of standard polymer (i.e., oligomeric PBT of Preparation Example 4, based on repeating units in PBT) and 0.005 mol of functional additive I-3 (prepared from Preparation Example 3). Continue copolymerization reaction for 3 h at 260 °C under vacuum. Then extrude and granulate to prepare copolymerized PBT standard sample 4#.

[0166] Molecular weight: 24679.

[0167] 5. Preparation of standard sample 5# of copolymerized PBT

[0168] Weigh 1 mol of standard polymer (i.e., oligomeric PBT-I of Preparation Example 6, based on repeating units in PBT), and continue copolymerization reaction at 260°C for 3 h under vacuum. Then, extrude and granulate to prepare copolymerized PBT standard sample 5#.

[0169] Molecular weight: 25457.

[0170] 6. Preparation of PBT blend standard sample #6

[0171] Weigh 99.7% copolymer PBT standard sample 1# (prepared from Example 1) and 0.3% functional additive II-1 (prepared from Comparative Preparation Example 1), stir thoroughly, add to a twin-screw extruder to melt, extrude, cool, granulate, and dry to prepare blended PBT standard sample 6#.

[0172] 7. Preparation of PBT blend standard sample #7

[0173] Weigh 99.7% copolymer PBT standard sample 1# (prepared from Example 1) and 0.3% functional additive II-2 (prepared from Comparative Preparation Example 2), stir thoroughly, add to a twin-screw extruder to melt, extrude, cool, granulate, and dry to prepare blended PBT standard sample 7#.

[0174] Test Example 1:

[0175] Take copolymer PBT standard samples 1-5# and blended PBT standard samples 6-7# (prepared from Example 1). Two copies of 2-7# were prepared in parallel. One copy was soaked in xylene for 24 hours and then dried, while the other copy was left untreated.

[0176] The above samples were subjected to xenon lamp aging tests according to SAE J 2527 standard, and the test results are shown in Table 1:

[0177] Table 1: ΔE* of samples after xenon lamp aging (lower values ​​are required)

[0178]

[0179] As shown in the table above, the hindered amine light stabilizer provided by this invention can directly bond with PBT monomers or oligomers. This not only enhances the compatibility and adhesion between polymer chains but also effectively reduces migration in organic solvents, thereby forming a copolymer PBT material with good weather resistance and migration resistance. Compared with blended PBT materials prepared by traditional physical blending methods, the copolymer PBT material prepared by the copolymerization method of this invention has significantly improved weather resistance and solvent migration resistance. Furthermore, this preparation process is simple and environmentally friendly.

[0180] Example 2:

[0181] 1. Preparation of standard sample 1# of copolymerized PET

[0182] Weigh 100wt% of oligomeric PET-1 (i.e., the oligomeric PET of Preparation Example 5), and continue the copolymerization reaction at 250°C for 4 hours under vacuum. Then, extrude and granulate to prepare copolymer PET standard sample 1#.

[0183] Molecular weight: 19678.

[0184] 2. Preparation of standard sample #2 of copolymerized PET

[0185] Weigh 1 mol of standard polymer (i.e., the oligomeric PET of Preparation Example 5, based on repeating units in PET) and 0.005 mol of functional additive I-1 (prepared from Preparation Example 1). Continue the copolymerization reaction at 250°C for 4 hours under vacuum. Then, extrude and granulate to prepare copolymerized PET standard sample 2#.

[0186] Molecular weight: 20314.

[0187] 3. Preparation of standard sample #3 of copolymerized PET

[0188] Weigh 1 mol of standard polymer (i.e., the oligomeric PET of Preparation Example 5, based on repeating units in PET) and 0.005 mol of functional additive I-2 (prepared from Preparation Example 2). Continue the copolymerization reaction at 250°C for 4 hours under vacuum. Then extrude and granulate to prepare copolymerized PET standard sample 3#.

[0189] Molecular weight: 21645.

[0190] 4. Preparation of standard sample #4 of copolymerized PET

[0191] Weigh 1 mol of standard polymer (i.e., the oligomeric PET of Preparation Example 5, based on repeating units in PET) and 0.005 mol of functional additive I-3 (prepared from Preparation Example 3). Continue the copolymerization reaction at 250°C for 4 hours under vacuum. Then, extrude and granulate to prepare copolymerized PET standard sample 3#.

[0192] Molecular weight: 21781.

[0193] 5. Preparation of standard sample 5# of copolymerized PET

[0194] Weigh 1 mol of standard polymer (i.e., oligomeric PET-I of Preparation Example 7, based on repeating units in PET), and continue copolymerization reaction at 250°C for 4 h under vacuum. Then, extrude and granulate to prepare copolymerized PET standard sample 5#.

[0195] Molecular weight: 21540.

[0196] 6. Preparation of PET blend standard sample #6

[0197] Weigh 99.7% copolymer PET standard sample 1# (prepared from Example 2) and 0.3% functional additive II-1 (prepared from Comparative Preparation Example 1), stir thoroughly, add to a twin-screw extruder to melt, extrude, cool, granulate, and dry to prepare blended PET standard sample 6#.

[0198] 7. Preparation of Blended PET Standard Sample #7

[0199] Weigh 99.7% copolymer PET standard sample 1# (prepared from Example 2) and 0.3% functional additive II-2 (prepared from Comparative Preparation Example 2), stir thoroughly, add to a twin-screw extruder to melt, extrude, cool, granulate, and dry to prepare blended PET standard sample 7#.

[0200] Test Example 2:

[0201] Take copolymer PET standard samples 1-5# and blended PET standard samples 6-7# (prepared from Example 2). Two copies of 2-7# were prepared in parallel. One copy was soaked in xylene for 24 hours and then dried, while the other copy was left untreated.

[0202] The above samples were subjected to xenon lamp aging tests according to SAE J 2527 standard, and the test results are shown in Table 2:

[0203] Table 2: ΔE* of samples after xenon lamp aging (lower values ​​are required)

[0204]

[0205]

[0206] As shown in the table above, the hindered amine light stabilizer provided by this invention can directly bond with PET monomers or oligomers. This not only enhances the compatibility and adhesion between polymer chains but also effectively reduces migration in organic solvents, thereby forming a copolymerized PET material with excellent weather resistance and solvent migration resistance. Compared with blended PET materials prepared by traditional physical blending methods, the copolymerized PET material prepared by this invention exhibits significantly improved weather resistance and solvent migration resistance. Furthermore, this preparation process is simple and environmentally friendly.

[0207] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0208] The foregoing embodiments and methods described in this invention may vary based on the capabilities, experience, and preferences of those skilled in the art.

[0209] Listing the steps of the method in a certain order in this invention does not constitute any restriction on the order of the method steps.

Claims

1. A modified polyester, characterized in that, The modified polyester is prepared by copolymerization of oligopolyester and piperidine derivative, wherein the oligopolyester is oligopolyPBT or oligopolyPET. Alternatively, the modified polyester is prepared by copolymerization of the oligomer itself, and the oligomer is prepared by polycondensation of terephthalic acid or dimethyl terephthalate, diol and piperidine derivative, wherein the diol is 1,4-butanediol or ethylene glycol. The piperidine derivative has the structure shown in Formula I or Formula II: Among them, R1, R3, and R4 are independently selected from: H, C1-C 10 alkyl; R1', R3', and R4' are independently selected from: H, C1-C 10 alkyl; R2 is selected from: H, C1-C 10 Alkyl, -O-(C1-C 10 Alkyl), -O-(C3-C) 10 cycloalkyl); R2' is selected from: H, C1-C 10 Alkyl, -O-(C1-C 10 Alkyl), -O-(C3-C) 10 cycloalkyl); n is an integer from 1 to 5; The molecular weight of the modified polyester is 18,000-35,000.

2. The modified polyester according to claim 1, characterized in that, The molecular weight of the oligopolyester is 2000-8000, preferably 2500-5500; Preferably, the molecular weight of the oligomer is 2000-8000, more preferably 3400-6100; Preferably, the oligopolyester is oligomeric PBT, and the molecular weight of the modified polyester is 20,000-35,000; or, the oligopolyester is oligomeric PET, and the molecular weight of the modified polyester is 18,000-28,000. Preferably, the molecular weight of the modified polyester is 20,000-26,000.

3. The modified polyester according to claim 1, characterized in that, R1, R3, and R4 are independently selected from: H and C1-C6 alkyl groups; Preferably, R1', R3', and R4' are independently selected from: H, C1-C6 alkyl groups; Preferably, R2 is selected from: H, C1-C6 alkyl, -O-(C1-C6 alkyl), -O-(C3-C8 cycloalkyl); Preferably, R2' is selected from: H, C1-C6 alkyl, -O-(C1-C6 alkyl), -O-(C3-C8 cycloalkyl); More preferably, R1 is methyl; and / or, R1' is methyl; More preferably, R2 is H, methyl, or And / or, R2' is H, methyl, or More preferably, R3 is H or methyl; and / or, R3' is H or methyl; More preferably, R4 is H or methyl; and / or, R4' is H or methyl; More preferably, the piperidine derivative has the following structure:

4. The modified polyester according to claim 1, characterized in that, The molar ratio of repeating units to piperidine derivatives in the oligopolyester is 1:(0.001-1), preferably 1:(0.001-0.05); Preferably, the copolymerization reaction takes 1-12 hours, more preferably 2-8 hours; Preferably, the temperature of the copolymerization reaction is 0-280℃, more preferably 80-280℃ or 100-280℃, and even more preferably 250-260℃; Preferably, the copolymerization reaction is carried out in a vacuum.

5. The modified polyester according to claim 1, characterized in that, The molar ratio of terephthalic acid or dimethyl terephthalate to diol is 1:(1.5-6), preferably 1:(4.6-5.4) or 1:(4.5-5.3); Preferably, the molar ratio of terephthalic acid or dimethyl terephthalate to piperidine derivative is 1:(0.001-1), more preferably 1:(0.001-0.05); Preferably, the polycondensation reaction takes 2-6 hours, more preferably 4-6 hours; Preferably, the temperature of the polycondensation reaction is 150-250℃, more preferably 160-180℃ or 200-210℃.

6. The modified polyester according to any one of claims 1-5, characterized in that, The method for preparing the piperidine derivative includes the following steps: reacting a tetramethylpiperidineamine compound, the compound shown in Formula III, and / or the compound shown in Formula IV in a solvent to obtain the piperidine derivative; The tetramethylpiperidineamine compounds have the structure shown in formula V-1 or formula V-2: The compound represented by Formula III has the following structure: The compound represented by Formula IV has the following structure:

7. The modified polyester according to claim 6, characterized in that, The tetramethylpiperidineamine compound has the following structure: Preferably, the compound represented by Formula III has the following structure: Preferably, the compound represented by Formula IV has the following structure:

8. The modified polyester according to claim 6, characterized in that, The solvent is selected from one or more of toluene, xylene, cyclohexane, octane, heptane, and tetrahydrofuran; Preferably, when the tetramethylpiperidineamine compound reacts only with the compound shown in Formula III, the molar ratio of the tetramethylpiperidineamine compound to the compound shown in Formula III is 1:(2-5); or, when the tetramethylpiperidineamine compound reacts only with the compound shown in Formula IV, the molar ratio of the tetramethylpiperidineamine compound to the compound shown in Formula IV is 1:(2-5); or, when the tetramethylpiperidineamine compound reacts with the compounds shown in Formulas III and IV, the molar ratio of the tetramethylpiperidineamine compound to the compounds shown in Formulas III and IV is 1:(2-5). Preferably, the reaction temperature is 20-120°C, and the reaction time is 6-24 hours.

9. An application of the modified polyester as described in any one of claims 1-8 as a polymer material.

10. The application according to claim 9, characterized in that, The polymer material is plastic, fiber, resin or rubber.

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