Polymeric hindered amine light stabilizer, and preparation method and application thereof

Abstract

The application relates to a polymeric hindered amine light stabilizer and a preparation method and application thereof. The polymeric hindered amine light stabilizer is a polymerization product of a mixed dibasic acid raw material and a hydroxyalkyl piperidine alcohol with a formula I, wherein R is C 1‑6 alkylene, R1, R2, R3 and R4 are each independently selected from C 1‑6 alkyl; the mixed dibasic acid raw material comprises two or more dibasic acids and / or dialkyl esters thereof.

Description

Technical Field

[0001] This invention relates to polymeric hindered amine light stabilizers, their preparation methods, and applications. Background Technology

[0002] Poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol) ester (CAS No. 65447-77-0, also known as light stabilizer 622) is a commercially available oligomeric hindered amine light stabilizer. Due to its polymeric hindered amine light stabilizer and high molecular weight, it exhibits excellent processing thermal stability, water extraction resistance, and good compatibility with various resins, making it suitable for polyethylene, polypropylene, polystyrene, olefin copolymers, polyesters, flexible PVC, polyurethane, polyoxymethylene, and polyamides.

[0003] When light stabilizer 622 is used, it is mostly used in combination with other light stabilizers. For example, patent CN103059420B mentions that poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol) ester and 2-[2-hydroxy-4-(2,2,6,6-tetramethylpiperidin-4-oxy)carbonylmethoxyphenyl]-2H-benzotriazole are mixed and used in light-resistant polypropylene materials, which has good application effects. However, light stabilizer 622 requires the reaction of high-purity dimethyl succinate with N-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol to prepare it, which results in high preparation costs. Summary of the Invention

[0004] This invention provides a polymerizable hindered amine light stabilizer, which is a polymer of a mixture of diacid raw materials and a hydroxyalkylpiperidine alcohol having formula I. Where R is C 1-6 Alkylenes, R1, R2, R3, and R4 are each independently selected from C1. 1-6 alkyl; The mixed dicarboxylic acid raw material contains two or more dicarboxylic acids and / or their dialkyl esters.

[0005] In some embodiments, the mixed dicarboxylic acid raw material comprises at least two of the following: succinic acid and / or its dimethyl ester, glutaric acid and / or its dimethyl ester, adipic acid and / or its dimethyl ester, pimelic acid and / or its dimethyl ester, octanoic acid and / or its dimethyl ester, azelaic acid and / or its dimethyl ester, sebacic acid and / or its dimethyl ester, undecanoic acid and / or its dimethyl ester, and dodecanoic acid and / or its dimethyl ester.

[0006] In some embodiments, the mixed dicarboxylic acid raw material includes two or three of succinic acid, glutaric acid, and adipic acid; or, the mixed dicarboxylic acid raw material includes two or three of dimethyl succinate, dimethyl glutarate, and dimethyl adipic acid.

[0007] In some embodiments, the mixed dicarboxylic acid raw material is a combination of dimethyl succinate, dimethyl glutarate, and dimethyl adipate, wherein dimethyl succinate accounts for 10-50%, dimethyl glutarate accounts for 50-90%, and dimethyl adipate accounts for 10-50%, based on the total weight of the mixed dicarboxylic acid raw material.

[0008] In some embodiments, R is ethylene, and R1, R2, R3 and R4 are methyl.

[0009] In some embodiments, the polymeric hindered amine light stabilizer comprises two or more oligomers having different p values ​​in Formula II. (II) Where p is an integer from 2 to 12; n is an integer from 3 to 150.

[0010] In some embodiments, the number-average molecular weight of the polymeric hindered amine light stabilizer is 1000-10000; And / or, the molecular weight distribution (PDI) of the polymeric hindered amine light stabilizer is 1.5-3.0.

[0011] In some embodiments, the number-average molecular weight of the polymeric hindered amine light stabilizer is 4000-7000.

[0012] In some embodiments, the molecular weight distribution (PDI) of the polymeric hindered amine light stabilizer is 1.8-2.5.

[0013] This application also relates to a method for preparing polymeric hindered amine light stabilizers, including: The hydroxyalkylpiperidine alcohol having formula I is reacted with a mixed dicarboxylic acid feedstock in the presence of a catalyst; Where R is C 1-6 Alkylenes, R1, R2, R3, and R4 are each independently selected from C1. 1-6 alkyl; The mixed dicarboxylic acid raw material contains two or more dicarboxylic acids and / or their dialkyl esters.

[0014] This application also relates to a light stabilizer composition comprising the polymeric hindered amine light stabilizer of this application and a second hindered amine light stabilizer.

[0015] In some embodiments, the weight ratio of the polymeric hindered amine light stabilizer to the second hindered amine light stabilizer is 1:0.1~10.

[0016] In some embodiments, the second hindered amine light stabilizer is poly-{[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexylene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]}.

[0017] This application also relates to the use of the polymeric hindered amine light stabilizer or light stabilizer composition of this application in agricultural films, artificial grass or photovoltaic films.

[0018] This application uses polymeric hindered amine light stabilizers obtained from mixed dicarboxylic acid raw materials, which improves product performance and application effects on the one hand, and reduces the cost of light stabilizer products on the other. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way.

[0020] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0021] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0022] In a first aspect, this application provides a polymerizable hindered amine light stabilizer, which is a polymer product of a mixed diacid raw material and a hydroxyalkylpiperidine alcohol having Formula I. Where R is C 1-6 Alkylenes, R1, R2, R3, and R4 are each independently selected from C1. 1-6 alkyl; The mixed diacid raw material comprises two or more diacids and / or their dialkyl esters. It should be noted that the mixed diacid raw material used in this application comprising two or more diacids and / or their dialkyl esters means that the mixed diacid raw material comprises two or more diacids with different numbers of carbon atoms, or comprises a combination of dialkyl esters derived from these diacids with different numbers of carbon atoms, or even comprises a combination of one or more diacids with different numbers of carbon atoms and another one or more dialkyl esters derived from diacids with different numbers of carbon atoms. For example, the mixed diacid raw material may include two or more of succinic acid, glutaric acid, adipic acid, etc., or two or more of their dialkyl esters, such as dimethyl esters. However, a combination comprising only one diacid and its dialkyl ester is not considered a mixed diacid raw material in this application.

[0023] In some embodiments, the dicarboxylic acid may be selected from succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, and dodecanoic acid. In some embodiments, the dialkyl ester of the dicarboxylic acid may be a dimethyl ester of the dicarboxylic acid, for example, it may be selected from dimethyl succinate, dimethyl glutarate, dimethyl adipate, dimethyl pimelic acid, dimethyl octanoate, dimethyl azelaate, dimethyl sebacic acid, dimethyl undecanoate, and dimethyl dodecanoate.

[0024] In some embodiments, the mixed dicarboxylic acid raw material comprises at least two selected from succinic acid and / or its dimethyl ester, glutaric acid and / or its dimethyl ester, adipic acid and / or its dimethyl ester, pimelic acid and / or its dimethyl ester, octanoic acid and / or its dimethyl ester, azelaic acid and / or its dimethyl ester, sebacic acid and / or its dimethyl ester, undecanoic acid and / or its dimethyl ester, and dodecanoic acid and / or its dimethyl ester. Preferably, the mixed dicarboxylic acid raw material comprises two or three selected from succinic acid, glutaric acid, and adipic acid; or, the mixed dicarboxylic acid raw material comprises two or three selected from dimethyl succinate, dimethyl glutate, and dimethyl adipate.

[0025] More preferably, the mixed dicarboxylic acid raw material can be a combination of dimethyl succinate, dimethyl glutarate, and dimethyl adipate. More preferably, dimethyl succinate accounts for 10-50% (e.g., 10%, 20%, 30%, 40%, 50%, and any value between these), dimethyl glutarate accounts for 50-90% (e.g., 50%, 60%, 70%, 80%, 90%, and any value between these), and dimethyl adipate accounts for 10-50% (e.g., 10%, 20%, 30%, 40%, 50%, and any value between these); for example, dimethyl succinate accounts for 17.5%, dimethyl glutarate accounts for 62.9%, and dimethyl adipate accounts for 19.5%, based on the total weight of the mixed dicarboxylic acid raw material (containing a small amount of impurities).

[0026] Byproducts of adipic acid production include mixed diacids (DBAs), which are liquid or solid mixtures produced during the process. Their main components include succinic acid, glutaric acid, and small amounts of unreacted adipic acid and other impurities. Glutaric acid accounts for approximately 60% of the DBAs. DBAs are important chemical raw materials used in the production of plasticizers, lubricants, and polyester polyols. However, due to their complex composition and high separation and purification costs, they were previously often used for low-value disposal or incineration, resulting in resource waste. The mixed diacid raw material used in this application can be mixed diacids (DBAs), a byproduct of adipic acid production, or its dimethyl ester product. This eliminates the need for complex separation and purification steps, reducing costs and improving product application effectiveness.

[0027] Because the mixed diacid raw materials used contain diacids with different numbers of carbon atoms, the resulting polymeric hindered amine light stabilizers also contain structures derived from these diacids with different numbers of carbon atoms. These structural differences can lead to varying solubility of the polymeric hindered amine light stabilizers in different solvents or polymer matrices. Therefore, compared to light stabilizer products obtained from a single diacid or its ester, the polymeric hindered amine light stabilizers of this application exhibit better compatibility in a wider range of systems, thereby achieving improved light stabilization.

[0028] In some implementations, R is C 1-6 Alkylenes, such as methylene, ethylene, propylene, butylene, tert-butylene, and hexylene, etc., wherein R1, R2, R3, and R4 are each independently selected from C1. 1-6 Alkyl groups, such as methyl, ethyl, n-propyl, isopropyl, tert-butyl, etc. Preferably, R is ethylene, and R1, R2, R3 and R4 are methyl groups, in which case the hydroxyalkylpiperidinol is N-(2'-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol (hereinafter referred to as hydroxyethylpiperidinol).

[0029] In some embodiments, the polymeric hindered amine light stabilizer comprises two or more oligomers having different p values ​​in Formula II. (II) Wherein, p is an integer from 2 to 12 (e.g., 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12), preferably an integer from 2 to 4; n is an integer from 3 to 150 (e.g., 3, 5, 7, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130 or 140), preferably an integer from 3 to 100.

[0030] In some embodiments, the number-average molecular weight of the polymeric hindered amine light stabilizer is 1000-10000 (e.g., any value between 1000, 2000, 3000, 4000, 4500, 5000, 5500, 6000, 7000, 8000, 9000, 10000), preferably 1000-6000, or 4000-7000. Products with a number-average molecular weight between 1000-1500 are liquid products; products with a number-average molecular weight between 3000-10000 are solid products. In particular, the polymeric hindered amine light stabilizer of this application with a number-average molecular weight of 4000-6000 exhibits better light stabilization performance.

[0031] In some embodiments, the polymeric hindered amine light stabilizer has a molecular weight distribution (PDI) of 1.5-3.0 (e.g., 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, and any value between these values), preferably 1.8-2.5. The polymeric hindered amine light stabilizer of this application has a wide molecular weight distribution: the high molecular weight fraction in the polymer provides better durability and thermal stability, while the low molecular weight fraction migrates more easily to the material surface, quickly providing protection. The combination of these two aspects provides a balanced protection in the initial and long term.

[0032] Secondly, this application relates to a method for preparing the polymeric hindered amine light stabilizer, comprising: The hydroxyalkylpiperidine alcohol having formula I is reacted with a mixed dicarboxylic acid feedstock in the presence of a catalyst; Where R is C 1-6 Alkylenes, R1, R2, R3, and R4 are each independently selected from C1. 1-6 alkyl; The mixed dicarboxylic acid raw material contains two or more dicarboxylic acids and / or their dialkyl esters.

[0033] The hydroxyalkylpiperidine alcohol and mixed dicarboxylic acid raw materials can be as described in the first aspect, and will not be repeated here.

[0034] Specifically, hydroxyalkylpiperidine alcohol and solvent can be mixed, heated to remove water, and after successful dehydration, a catalyst and mixed dicarboxylic acid raw materials can be added to carry out the reaction. The reaction temperature can be 100-200℃, and the vacuum degree can be 0.1-760 mmHg. After the reaction is completed, a white to pale yellow target product is obtained.

[0035] Specifically, the molar ratio of the total number of moles of the mixed dicarboxylic acid raw materials (calculated as dicarboxylic acid) to hydroxyalkylpiperidine alcohol can be 1-10, preferably 1-3.

[0036] The catalyst can be a commonly used catalyst, such as tetrabutyl titanate, dibutyltin dilaurate, sodium methoxide, p-toluenesulfonic acid, etc. The solvent can be xylene, toluene, etc.

[0037] Thirdly, this application relates to a light stabilizer composition comprising a polymeric hindered amine light stabilizer of the first aspect and a second hindered amine light stabilizer.

[0038] In some embodiments, the weight ratio of the polymeric hindered amine light stabilizer to the second hindered amine light stabilizer is 1:0.1 to 10, for example 1:0.1 to 5, 1:0.5 to 3, 1:0.5 to 2, for example 1:0.5, 1:1, 1:1.5.

[0039] In some embodiments, the second hindered amine light stabilizer may be poly-{[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexylene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]}(Poly-{[6-[(1,1,3,3-tetramethyl [butyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetrameteryl-4-piperidinyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidyl)imino]}), CAS No.: 71878-19-8, also known as light stabilizer 944, has a number average molecular weight typically between 2000 and 3100.

[0040] Fourthly, this application relates to the application of the polymeric hindered amine light stabilizer of the first aspect or the light stabilizer composition of the second aspect in agricultural films, artificial turf, or photovoltaic films. The polymeric hindered amine light stabilizer of the first aspect or the light stabilizer composition of the second aspect of this application can be used as a light stabilizer additive in agricultural films, artificial turf, or photovoltaic films. Agricultural films (including agricultural greenhouse films and agricultural ground cover films), artificial turf, and photovoltaic films are typically exposed to sunlight for extended periods and are susceptible to photo-oxidative degradation caused by ultraviolet radiation. By adding the polymeric hindered amine light stabilizer of the first aspect or the light stabilizer composition of the second aspect of this application, a "photoprotective barrier" can be constructed, blocking the free radical chain degradation reaction initiated by ultraviolet radiation, thereby significantly extending the product's lifespan. When the polymeric hindered amine light stabilizer of the first aspect of this application or the light stabilizer composition of the second aspect is used as a light stabilizer additive in agricultural films, artificial grass, or photovoltaic films, its dosage can be 0.05% to 5% (e.g., 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, and any value between these values), preferably 0.1% to 2%, based on the total weight of the raw material composition used to prepare the agricultural film, artificial grass, or photovoltaic film.

[0041] The present application will be further described in detail below through embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0042] In the following examples, hydroxyethylpiperidinol is N-(2'-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol, CAS number 52722-86-8.

[0043] Example 1 A1. At room temperature, add 100g of wet hydroxyethylpiperidinol and 200g of xylene to a 1L four-necked flask equipped with a thermometer and a condenser. Heat to 130-140℃ and reflux to remove water until no water droplets are released, obtaining an anhydrous hydroxyethylpiperidinol solution. Collect 10g of the removed water.

[0044] The obtained anhydrous hydroxyethylpiperidinol solution (containing 90 g of hydroxyethylpiperidinol), 73 g of mixed acid dimethyl esters (17.5 wt% dimethyl succinate, 62.9 wt% dimethyl glutarate, 19.5 wt% dimethyl adipate, and containing a small amount of impurities), and 0.5 g of tetraisopropyl titanate were added to a reactor. The temperature was maintained at 130–150 °C, and methanol and solvent were slowly removed. After reacting for 2 hours, the reaction was carried out under high vacuum (0.1–2 mmHg) at 160–170 °C for 0.5 hours, yielding a colorless to pale yellow solid. The target product was 149.85 g, with a yield of 99.5%, a number-average molecular weight of 5474, and a PDI of 1.979. This product was designated as light stabilizer A1 (additive A1).

[0045] B1. Take 50g of the above target product and 50g of light stabilizer 944 and melt-mix them to obtain mixed light stabilizer B1 (additive B1).

[0046] Example 2 A2. At room temperature, add 100g of wet hydroxyethylpiperidinol and 200g of xylene to a 1L four-necked flask equipped with a thermometer and a condenser. Heat to 130-140℃ and reflux to remove water until no water droplets are released, obtaining an anhydrous hydroxyethylpiperidinol solution. Collect 9.5g of the removed water.

[0047] The obtained anhydrous hydroxyethylpiperidinol solution (containing 90.5 g of hydroxyethylpiperidinol), 65 g of mixed acids (20.1 wt% succinic acid, 59.7 wt% glutaric acid, and 20.2 wt% adipic acid), and 1 g of p-toluenesulfonic acid were added to a reactor. The temperature was maintained at 130–150 °C, and methanol and solvent were slowly removed. After reacting for 2 hours, the reaction was carried out under high vacuum (0.1–2 mmHg) at 160–170 °C for 0.5 hours, yielding a colorless to pale yellow solid. 135 g of the target product was obtained, with a yield of 99.1%, a number-average molecular weight of 4786, and a PDI of 2.127. This product was designated as light stabilizer A2 (additive A2).

[0048] B2. Take 50g of the above target product and 50g of light stabilizer 944 and melt-mix them to obtain mixed light stabilizer B2 (additive B2).

[0049] Example 3 A3. At room temperature, add 100g of wet hydroxyethylpiperidinol and 200g of xylene to a 1L four-necked flask equipped with a thermometer and a condenser. Heat to 130-140℃ and reflux to remove water until no water droplets are removed, obtaining an anhydrous hydroxyethylpiperidinol solution. Collect 10g of the removed water.

[0050] The obtained anhydrous hydroxyethylpiperidinol solution (containing 90 g of hydroxyethylpiperidinol), 70 g of mixed acid dimethyl esters (17.5 wt% dimethyl succinate, 62.9 wt% dimethyl glutarate, 19.5 wt% dimethyl adipate, containing a small amount of impurities), and 0.5 g of tetraisopropyl titanate were added to a reactor. The temperature was maintained at 130–150 °C, and methanol and solvent were slowly removed. After reacting for 2 hours, the reaction was carried out under high vacuum (0.1–2 mmHg) at 160–170 °C for 0.5 hours, yielding a colorless to pale yellow solid. The target product was 145.6 g, with a yield of 99.1%, a number-average molecular weight of 5925, and a PDI of 1.949. This product was designated as light stabilizer A3 (additive A3).

[0051] B3. Take 50g of the above target product and 50g of light stabilizer 944 and melt-mix them to obtain mixed light stabilizer B3 (additive B3).

[0052] Example 4 A4. At room temperature, add 100g of wet hydroxyethylpiperidinol and 200g of xylene to a 1L four-necked flask equipped with a thermometer and a condenser. Heat to 130-140℃ and reflux to remove water until no water droplets are removed, yielding an anhydrous hydroxyethylpiperidinol solution. Collect 7.9g of the removed water.

[0053] The obtained anhydrous hydroxyethylpiperidinol solution (containing 92.1 g of hydroxyethylpiperidinol), 90 g of mixed acid dimethyl esters (19.5 wt% dimethyl succinate, 56.7 wt% dimethyl glutarate, and 23.8 wt% dimethyl adipate), and 0.5 g of tetraisopropyl titanate were added to a reactor. The temperature was maintained at 130–150 °C, and methanol and solvent were slowly removed. After reacting for 2 hours, the reaction was carried out under high vacuum (0.1–2 mmHg) at 160–170 °C for 0.5 hours, yielding a colorless to pale yellow solid. 150 g of the target product was obtained, with a yield of 99.3%, a number-average molecular weight of 3620, and a PDI of 2.074. This product was designated as light stabilizer A4 (additive A4).

[0054] B4. Take 50g of the above target product and 50g of light stabilizer 944 and melt-mix them to obtain mixed light stabilizer B4 (additive B4).

[0055] Example 5 At room temperature, 100g of wet hydroxyethylpiperidinol and 200g of xylene were mixed in a 1L four-necked flask equipped with a thermometer and a condenser. The mixture was heated to 130-140℃ and refluxed to remove water until no water droplets were expelled, yielding an anhydrous hydroxyethylpiperidinol solution. 8.7g of the desorbed water was collected.

[0056] The obtained anhydrous hydroxyethylpiperidinol solution (containing 91.3 g of hydroxyethylpiperidinol), 125 g of mixed acid dimethyl ester (19.5 wt% dimethyl succinate and 80.5 wt% dimethyl glutarate), and 0.5 g of tetraisopropyl titanate were added to the reactor. The temperature was maintained at 130-150 °C, and methanol and solvent were slowly removed. After reacting for 2 hours, the reaction was carried out under high vacuum of 0.1-2 mmHg at 160-170 °C for 0.5 hours to obtain a colorless to pale yellow viscous liquid. The target product was 150 g, with a yield of 99.1%, a number average molecular weight of 1592, and a PDI of 2.119.

[0057] Light stability performance application test A. Photostability test of additives A1-A4 (12µm agricultural ground cover film) 1. Preparation of the experimental film. LLDPE resin (brand name 1820, purchased from DuPont, USA) was thoroughly mixed with the additives listed in Table 1 at an addition rate of 0.20 wt%. The mixed sample was then granulated in a twin-screw extruder at a screw temperature of 200°C. The prepared sample particles were then blown into a film at a blowing temperature of 210°C, with a film thickness of 12 μm.

[0058] 2. Xenon lamp aging test. Cut the prepared sample film to a fixed size. Aging requirements shall be carried out in accordance with GB-13735-2017.

[0059] 3: Tensile mechanical testing. The sample films were tested before aging and after aging for 600 hours in accordance with GB-13735-2017. The results are shown in Table 1.

[0060] Table 1

[0061] Light stabilizer 622 is BASF Tinuvin @ 622 As shown in Table 1, the mechanical properties of the sample films decreased to varying degrees after aging for 600 hours. However, the mechanical properties of the sample films containing A1, A2, and A3 were superior to those containing light stabilizers 622 and A4 after 600 hours of aging. In contrast, the sample films containing light stabilizers A1, A2, and A3 still exhibited good mechanical properties after 600 hours of aging, with elongation at break retention rates all exceeding 90%, indicating that the light stabilizers prepared in this invention possess excellent photostability.

[0062] B. Light stability performance test of mixed light stabilizers B1-B4 (75µm agricultural polyethylene blown greenhouse film) 1. Preparation of the experimental film. LLDPE resin (grade 1820) was thoroughly mixed with the additives listed in Tables 2 and 4 at a concentration of 0.60 wt% according to the proportions in Table 2. The mixed sample was then granulated in a twin-screw extruder at a screw temperature of 200°C. The prepared sample granules were then blown into a film at a blowing temperature of 210°C and a film thickness of 75 μm.

[0063] 2. Xenon lamp aging test. Cut the prepared sample film to a fixed size. Aging requirements shall be carried out in accordance with GB / T-4455-2019.

[0064] 3: Tensile mechanical testing. The sample films (longitudinal and transverse) before aging (initial) and after aging (1200h, 2200h and 3000h respectively) were tested according to GB / T-4455-2019. The longitudinal test results are shown in Tables 2 and 3, and the transverse test results are shown in Tables 4-5.

[0065] Table 2

[0066] Table 3

[0067] Table 4

[0068] Table 5

[0069] Light stabilizer 783 is BASF Tinuvin @ 783 As shown in Table 2, the initial longitudinal tensile strength of the films with added B4 was somewhat poor. After aging for 1200 hours, the mechanical properties of the films all decreased to varying degrees. However, the mechanical properties of the films with added B1, B2, and B3 were all higher than those with added light stabilizers 622 and B4 after aging for 1200 hours. As shown in Tables 3-5, the longitudinal mechanical properties of the films with added light stabilizers B1, B2, B3, and B4 were better than those with added light stabilizer 783 after aging for more than 2200 hours. The transverse mechanical properties of the films with added light stabilizers B1, B2, B3, and B4 were better than those with added light stabilizer 783 both initially and after 3000 hours of aging. This indicates that the mixed light stabilizer prepared in this invention has excellent photostability.

[0070] 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 polymerizable hindered amine light stabilizer, characterized in that, The polymeric hindered amine light stabilizer is a polymer product of a mixed diacid raw material and a hydroxyalkylpiperidine alcohol having formula I. Where R is methylene, ethylene, or propylene, and R1, R2, R3, and R4 are methyl. The mixed dicarboxylic acid raw material is a combination of dimethyl succinate, dimethyl glutarate and dimethyl adipate, wherein dimethyl succinate accounts for 10-50%, dimethyl glutarate accounts for 50-90% and dimethyl adipate accounts for 10-50%, based on the total weight of the mixed dicarboxylic acid raw material. The number-average molecular weight of the polymeric hindered amine light stabilizer is 4000-7000; The molecular weight distribution (PDI) of the polymeric hindered amine light stabilizer is 1.5-3.

0.

2. The polymerizable hindered amine light stabilizer according to claim 1, characterized in that, R stands for ethylene.

3. The polymerizable hindered amine light stabilizer according to claim 1, characterized in that, The polymeric hindered amine light stabilizer comprises two or more oligomers having different p values ​​in Formula II. (II) Where p is an integer from 2 to 12; n is an integer from 3 to 150.

4. The polymerizable hindered amine light stabilizer according to claim 1, characterized in that, The molecular weight distribution (PDI) of the polymeric hindered amine light stabilizer is 1.8-2.

5.

5. A method for preparing the polymeric hindered amine light stabilizer according to any one of claims 1-4, comprising: The hydroxyalkylpiperidine alcohol having formula I is reacted with a mixed dicarboxylic acid feedstock in the presence of a catalyst; Where R is methylene, ethylene, or propylene, and R1, R2, R3, and R4 are methyl. The mixed dicarboxylic acid raw material is a combination of dimethyl succinate, dimethyl glutarate and dimethyl adipate, wherein dimethyl succinate accounts for 10-50%, dimethyl glutarate accounts for 50-90% and dimethyl adipate accounts for 10-50%, based on the total weight of the mixed dicarboxylic acid raw material.

6. A light stabilizer composition comprising the polymeric hindered amine light stabilizer according to any one of claims 1-3, and a second hindered amine light stabilizer.

7. The light stabilizer composition according to claim 6, wherein, The weight ratio of the polymeric hindered amine light stabilizer to the second hindered amine light stabilizer is 1:0.1~10.

8. The light stabilizer composition according to claim 6, wherein, The second hindered amine light stabilizer is poly-{[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]}.

9. The use of the polymeric hindered amine light stabilizer of any one of claims 1-4 or the light stabilizer composition of any one of claims 6-8 in agricultural films, artificial grass or photovoltaic films.

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