Method for preparing hindered amine light stabilizer

Abstract

The invention provides a method for preparing a hindered amine light stabilizer. The method comprises the following steps: (1) carrying out substitution reaction on a compound I-2 and alcohol amine as shown in a formula I-3 to obtain a compound I-4; and (2) carrying out an alkoxylation reaction on the compound I-4 and cyclohexane in the presence of an oxidizing agent to obtain the hindered amine light stabilizer as shown in the formula I. The method disclosed by the invention is short in period, high in total product yield and simple in post-treatment step. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the technical field of light stabilizers, and in particular to a method for preparing a hindered amine light stabilizer. Background Art

[0002] Hindered Amine Light Stabilizer (HALS) is a class of compounds based on 2,2,6,6-tetramethylpiperidine. It is called hindered amine light stabilizer because it contains a piperidine group and two methyl groups are attached to the carbon atoms on both sides of the nitrogen atom of the piperidine group. The groups attached to the nitrogen atom are hindered by the groups on both sides.

[0003] Traditional hindered amine light stabilizers are developed from the structure of triacetoneamine. The NH group on the piperidine ring makes the light stabilizer very alkaline, which limits the use of hindered amine light stabilizers in acidic resins, acidic compounding agents and acidic environmental conditions. In order to broaden its application field, low alkalinity research has become a research hotspot for HALS light stabilizers. Light stabilizer UV-152 (2,4-bis-[N-n-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethyl-4-piperidinyl)amino]-6-(2-hydroxyethylamino)-1,3,5-triazine) is a piperidine-based N-alkoxy substituted hindered amine. Its alkalinity is only one ten-thousandth of that of non-substituted hindered amine light stabilizers. The hydroxyethylamino group cross-links with certain substances such as melamine and isocyanate, which can give the product excellent resistance to extraction and migration. At the same time, it has extremely low volatility and has better light stabilization than traditional HALS.

[0004] The prior art reports a three-step method for synthesizing hindered amine light stabilizer UV-152 using cyanuric chloride, 2,2,6,6-tetramethyl-4-piperidinylbutylamine, cyclohexane and ethanolamine as the main raw materials. The method uses acetone as a solvent to synthesize the intermediate disubstituted cyanuric chloride; then uses MoO3 as a catalyst to react the intermediate disubstituted cyanuric chloride with cyclohexane; finally, uses toluene as a solvent and sodium bicarbonate as an acid-binding agent to synthesize the target product UV-152, with a low total yield of only 64.4%. In addition, the process route has the problem of complex post-processing and multiple desolventizing. Summary of the invention

[0005] In order to solve one of the above technical problems existing in the prior art, the present invention provides a method for preparing a hindered amine light stabilizer. The method is simple and efficient, convenient for post-processing and has a high total yield in the preparation of hindered amine light stabilizers, especially UV-152.

[0006] The present invention provides a method for preparing a hindered amine light stabilizer as shown in the following formula I, comprising the following steps:

[0007] (1) Compound I-2 undergoes a substitution reaction with an alcohol amine represented by formula I-3 to obtain compound I-4;

[0008]

[0009] (2) Compound I-4 is subjected to an alkoxylation reaction with cyclohexane in the presence of an oxidant to obtain a hindered amine light stabilizer represented by formula I.

[0010]

[0011] In the above-mentioned compound I-2, compound I-4 and formula I, R is selected from hydrogen and C1-C10 alkyl; in formula I-3, compound I-4 and formula I, L is selected from C1-C10 alkylene.

[0012] According to some embodiments of the present invention, in the above-mentioned compound I-2, compound I-4 and formula I, R is selected from hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl or isohexyl.

[0013] According to some embodiments of the present invention, in the above-mentioned compound I-2, compound I-4 and formula I, R is selected from n-butyl, isobutyl or tert-butyl.

[0014] According to some preferred embodiments of the present invention, in the above-mentioned compound I-2, compound I-4 and formula I, R is n-butyl.

[0015] According to some embodiments of the present invention, in Formula I-3, Compound I-4 and Formula I, L is selected from methylene, ethylene, propylene, isopropylene, butylene, isobutylene or tert-butylene.

[0016] According to some embodiments of the present invention, in Formula I-3, Compound I-4 and Formula I, L is selected from methylene, ethylene or propylene.

[0017] According to some preferred embodiments of the present invention, in Formula I-3, Compound I-4 and Formula I, L is ethylene.

[0018] According to some preferred embodiments of the present invention, the compound of formula I has the structure shown below:

[0019]

[0020] According to some embodiments of the present invention, compound I-2 is prepared by a method comprising the following steps:

[0021] (S1) reacting cyanuric chloride with compound I-1 in an aromatic hydrocarbon solvent to obtain an organic phase containing compound I-2,

[0022]

[0023] In compound I-1 and compound I-2, the definition of R is the same as that defined above.

[0024] According to some embodiments of the present invention, in step (S1), the aromatic hydrocarbons include one or more of toluene, xylene, chlorobenzene, trimethylolbenzene, and methylethylbenzene. According to some embodiments of the present invention, in step S1, the aromatic hydrocarbons include toluene and / or xylene.

[0025] In the present invention, the organic phase containing compound 1-2 obtained in step (S1) is an aromatic hydrocarbon solution of compound 1-2. In some embodiments, the organic phase containing compound 1-2 obtained in step (S1) is a toluene solution of compound 1-2. In some embodiments, the organic phase containing compound 1-2 obtained in step (S1) is a xylene solution of compound 1-2.

[0026] According to some embodiments of the present invention, in step (S1), the molar ratio of cyanuric chloride to the aromatic hydrocarbon is 1:(4-20), for example, 1:4, 1:5, 1:8, 1:10, 1:12, 1:15, 1:18, 1:20 or any value therebetween.

[0027] According to some embodiments of the present invention, in step (S1), the molar ratio of cyanuric chloride to compound I-1 is 1:(1.8-2.2), for example, 1:1.8, 1:1.9, 1:2.0, 1:2.1, 1:2.2 or any value therebetween.

[0028] According to some embodiments of the present invention, in step (S1), the reaction temperature is 50-70°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C or any value therebetween.

[0029] According to some embodiments of the present invention, in step (S1), water is added to the reaction system before and / or after the reaction of cyanuric chloride and compound I-1. In some embodiments, in order to fully dissolve the generated salt and separate it cleanly, in step (S1), the volume ratio of the aromatic hydrocarbon to the added water is (0.8 to 1.5): 1, for example, 0.8: 1, 0.9: 1, 1.0: 1, 1.2: 1, 1.5: 1 or any value therebetween.

[0030] According to some embodiments of the present invention, in step (S1), after cyanuric chloride reacts with compound I-1, the aqueous phase in the reaction system is removed to obtain an organic phase containing compound I-2. In the present invention, the organic phase containing compound I-2 obtained in step (S1) can be used directly in step (1) for substitution reaction with the alcoholamine shown in formula I-3 without separation. In the present invention, by adding water to the reaction system, the salts generated in the reaction can be dissolved, and the organic phase of compound I-2 can be separated by a simple liquid separation operation during the post-treatment process, and the salts generated in the reaction can be removed at the same time, and the separation and purification process is simple.

[0031] According to some embodiments of the present invention, in step (S1), the substitution reaction is carried out in the presence of an acid binding agent. In some embodiments, the acid binding agent includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0032] According to some embodiments of the present invention, in step (1), the molar ratio of the alcohol amine represented by formula I-3 to compound I-2 is (0.8-1.5):1, for example, 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1 or any value therebetween, preferably (0.8-1.2):1.

[0033] According to some embodiments of the present invention, in step (1), the temperature of the substitution reaction is 100-180°C, for example, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C or any value therebetween, preferably 150-180°C.

[0034] According to some embodiments of the present invention, in step (1), the substitution reaction time is 6 to 18 h, for example, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h or any value therebetween.

[0035] According to some embodiments of the present invention, in step (1), the substitution reaction is carried out in an aromatic organic solvent. In some embodiments, the aromatic organic solvent includes one or more of toluene, xylene, chlorobenzene, trimethylolbenzene, and methylethylbenzene. In some preferred embodiments, the aromatic organic solvent includes toluene and / or xylene. In some embodiments, water is also added to the reaction system of step (1). In some embodiments, in step (1), the volume ratio of the aromatic organic solvent to water is (3 to 5): 1, preferably (3.5 to 4.5): 1.

[0036] According to some embodiments of the present invention, in step (1), the substitution reaction is carried out in the presence of an acid binding agent. In some embodiments, the acid binding agent includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

[0037] According to some embodiments of the present invention, step (1) further comprises: after the substitution reaction is completed, cooling and standing to separate the liquids to obtain an organic phase, and removing the organic solvent in the organic phase to obtain compound I-4.

[0038] According to some embodiments of the present invention, in step (1), the substitution reaction is carried out under high pressure, for example, in a high pressure reactor. In some embodiments, the pressure of the high pressure reactor is 0.4 MPa to 2 MPa.

[0039] According to some embodiments of the present invention, in step (2), the oxidant comprises a peroxide. The peroxide of the present invention includes, but is not limited to, one or more of tert-butyl hydroperoxide, hydrogen peroxide, and peracetic acid. In some embodiments, the oxidant comprises tert-butyl hydroperoxide and / or hydrogen peroxide. In some preferred embodiments, the oxidant comprises hydrogen peroxide.

[0040] According to some embodiments of the present invention, the molar ratio of the oxidant to compound I-4 is (4-15):1, for example, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 12:1, 15:1 or any value therebetween, preferably (4-10):1.

[0041] According to some embodiments of the present invention, in step (2), the alkoxylation reaction is carried out in the presence of a catalyst. In some embodiments, the molar ratio of the catalyst of the alkoxylation reaction to compound I-4 is (0.01 to 0.1): 1, for example, 0.01: 1, 0.02: 1, 0.03: 1, 0.05: 1, 0.08: 1, 0.1: 1 or any value therebetween. In some embodiments, the catalyst of the alkoxylation reaction includes one or more of molybdenum trioxide, magnesium oxide, magnesium hydroxide, sodium carbonate, sodium chloride, cuprous chloride, ferric chloride, and ferrous chloride. In some preferred embodiments, the catalyst of the alkoxylation reaction includes one or more of molybdenum trioxide, ferric chloride, and ferrous chloride.

[0042] According to some embodiments of the present invention, in step (2), the molar ratio of cyclohexane to compound I-4 is (12-20):1, for example, 12:1, 14:1, 16:1, 18:1, 20:1 or any value therebetween.

[0043] According to some embodiments of the present invention, in step (2), the temperature of the alkoxylation reaction is 75-130°C.

[0044] According to some embodiments of the present invention, step (2) further comprises: after the alkoxylation reaction is completed, adding a decolorizing agent to the reaction system. In some embodiments, the decolorizing agent includes but is not limited to: one or more of kaolin, activated carbon, silica gel, resin, and EDTA. In some preferred embodiments, the decolorizing agent includes EDTA.

[0045] According to some embodiments of the present invention, in step (2), after the alkylation reaction is completed, the temperature is first lowered and the catalyst is removed, and then a decolorizing agent is added.

[0046] According to some embodiments of the present invention, in step (2), after adding the decolorizing agent, solid-liquid separation is performed to obtain a liquid phase; the liquid phase is decompressed to remove the solvent to obtain the hindered amine light stabilizer shown in formula I.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] (1) The present invention adopts a preparation method of first substituting and then alkoxylating, which has simple post-treatment and short production cycle, is suitable for N-alkoxylation of hindered amine light stabilizers, and is easy to industrialize and mass produce.

[0049] (2) According to the method of the present invention, the intermediate product obtained by the reaction of cyanuric chloride and piperidine butylamine does not need to be subjected to complicated post-treatment and can be directly used for the next step of the reaction only by removing water, and the product yield is high.

[0050] (3) The preparation method of first replacing and then alkoxylating is adopted, which eliminates the operation of removing and recovering the acetone solvent, reduces the types of solvents, reduces the production cost of solvent recovery and reuse, reduces the types of impurities, improves product quality, reduces equipment investment, and saves costs.

[0051] (4) The method of the present invention can greatly reduce the amount of cyclohexane used during the alkoxylation reaction, and does not require the addition of sodium bisulfite or sodium bicarbonate for neutralization after the reaction, so the post-treatment is simple and the yield is further improved.

[0052] (5) The method of the present invention can shorten the reaction time from 50 h to 42 h, and increase the total yield of the product from 64.4% to more than 90%, with a short production cycle, high efficiency and low energy consumption. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to constitute any limitation to the present invention.

[0054] The reagents used in the following experiments of the present invention, unless otherwise specified, are all conventional commercial products or reagents prepared by conventional methods, and the methods used in the experiments, unless otherwise specified, are all conventional experimental methods. The instruments used in the experiments, unless otherwise specified, can all be obtained through commercial channels.

[0055] The hindered amine light stabilizer of the present invention includes a UV-152 hindered amine light stabilizer shown in the following formula:

[0056]

[0057] As a specific embodiment of the present invention, a method for preparing hindered amine light stabilizer UV-152 is provided, comprising the following steps:

[0058] (a) reacting cyanuric chloride with 2,2,6,6-tetramethyl-4-piperidinylbutylamine in an aromatic hydrocarbon solvent, adding water to the liquid phase obtained after the reaction, and then removing the water by separation to obtain an aromatic hydrocarbon solution of the intermediate 1;

[0059] (b) subjecting the aromatic hydrocarbon solution of intermediate 1 to a substitution reaction with ethanolamine in the presence of an acid binder and water, and removing water and aromatic hydrocarbon organic solvent from the liquid phase after the reaction to obtain intermediate 2;

[0060] (c) subjecting the intermediate 2, cyclohexane and an oxidant to an alkoxylation reaction in the presence of a catalyst, removing the catalyst after the reaction and adding a decolorizing agent for decolorization, and then removing the decolorizing agent and the solvent to obtain UV-152.

[0061] In the present invention, the same reaction solvent is used in step (a) and step (b), and the operation of recovering the acetone solvent in the prior art is omitted after step (a) is completed, thereby reducing the types of solvents and reducing equipment investment. In addition, the product obtained by the reaction of the intermediate 1 with ethanolamine in the present invention only needs to be washed with water and then separated to remove water, without the need for complicated post-treatment.

[0062] In the above step (a), the aromatic hydrocarbons include one or more of toluene, xylene, chlorobenzene, trimethylolbenzene, and methylethylbenzene, preferably toluene and / or xylene.

[0063] In the above step (a), the molar ratio of cyanuric chloride to aromatic hydrocarbon is 1:(4-20), preferably 1:(4-10).

[0064] In the above step (a), the molar ratio of cyanuric chloride to 2,2,6,6-tetramethyl-4-piperidinylbutylamine is 1:(1.8-2.2).

[0065] In the above step (b), the molar ratio of ethanolamine to cyanuric chloride in step (a) is (0.8-1.5):1, preferably (0.8-1.2):1.

[0066] In the above step (b), the acid binding agent includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate.

[0067] In the above step (b), the reaction is preferably carried out under high pressure conditions to obtain a higher yield and a better quality product, for example, in a high pressure reactor. The pressure of the high pressure reactor is preferably 0.4 MPa-2 MPa.

[0068] In the above step (c), the molar ratio of cyclohexane to the cyanuric chloride in step (a) is (12-20):1.

[0069] In the above step (c), the catalyst includes one or more of molybdenum trioxide, magnesium oxide, magnesium hydroxide, sodium carbonate, sodium chloride, cuprous chloride, ferric chloride, and ferrous chloride; preferably includes molybdenum trioxide, ferric chloride, or ferrous chloride.

[0070] In the above step (c), the molar ratio of the catalyst to the cyanuric chloride in step (a) is (0.01-0.1):1.

[0071] In the above step (c), the oxidant comprises one or more of tert-butyl hydroperoxide, hydrogen peroxide, and peracetic acid; preferably comprises tert-butyl hydroperoxide and hydrogen peroxide, and more preferably comprises hydrogen peroxide.

[0072] In the above step (c), the molar ratio of the oxidant to the cyanuric chloride in step (a) is (4-15):1, preferably (4-10):1.

[0073] In the above step (c), the decolorizing agent includes one or more of kaolin, activated carbon, silica gel, resin, and EDTA; preferably includes EDTA.

[0074] As a specific embodiment of the present invention, the method for preparing hindered amine light stabilizer UV-152 comprises the following steps:

[0075] (a1) After slurrying cyanuric chloride in an aromatic solvent, the temperature is lowered to 0-10°C, ice water is added at once, and then 2,2,6,6-tetramethyl-4-piperidinylbutylamine is added dropwise, and the temperature is controlled at 0-10°C. After the addition is completed, liquid alkali is added dropwise, and the temperature is controlled at 0-10°C. After the temperature is kept for 1 hour, the temperature is raised to 50-70°C and the temperature is kept for 4-10 hours. After the reaction is completed, the lower layer of water is separated and washed with water until neutral. The organic phase is a solution of intermediate 1;

[0076] (b1) Add the solution of intermediate 1, ethanolamine, acid binding agent and pure water into an autoclave, replace with nitrogen, start stirring, keep at 100-180°C for 6-18h, cool to 50-70°C, stand to separate water, wash with water 3 times, dehydrate, filter and desolventize to obtain intermediate 2;

[0077] (c1) After mixing the intermediate 2, cyclohexane and the catalyst, the temperature is raised to 70-130°C and the oxidant is added dropwise. After 4-28 hours of addition, the mixture is kept warm, stirred and refluxed until the color of the reaction solution fades (the solvent is replaced according to the situation during the reaction process). After the synthesis reaction is completed, the temperature is lowered to 60-80°C, the catalyst is filtered, and a decolorizing agent is added. After stirring for 1 hour, the mixture is filtered in a cycle and desolventized to obtain the finished product of UV-152.

[0078] In the present invention, “reflux until the reaction solution loses its color” means that the color of the red nitroxide radicals in the reaction solution that are refluxed fades.

[0079] In the following embodiments of the present invention, the synthetic route of hindered amine light stabilizer UV-152 is as follows:

[0080]

[0081]

[0082] Comparative Example 1

[0083] The synthetic route of UV-152 is as follows:

[0084]

[0085]

[0086] (1) Add 120 mL of acetone to the reaction kettle, cool to below 0°C in an ice-water bath (0.5 h), add 18.4 g of cyanuric chloride, and dropwise add 21.2 g of 2,2,6,6-tetramethyl-4-piperidinylbutylamine at a temperature of 0 to 5°C for 3 h; then slowly dropwise add 13.1 g of liquid alkali (32% sodium hydroxide aqueous solution by mass) at a temperature of 0 to 5°C for 1 h; after the addition is completed, heat to reflux (0.5 h), react for 6 h, cool and filter (1 h in total), add 600 mL of water to the filtrate, and precipitate a white product (3 h), namely, intermediate 1 (48.69 g), with a reaction yield of 91%.

[0087] (2) 120 mL of cyclohexane, 10.7 g of intermediate 1, 0.6 g of molybdenum oxide, and 21 g of 70% tert-butyl hydroperoxide were added to the reaction kettle, the temperature was raised to reflux (1 h), the reaction was carried out for 5 h, the temperature was lowered, and the mixture was filtered (a total of 1 h). Saturated aqueous sodium bicarbonate solution was added to the filtrate, the mixture was stirred for 30 min, allowed to stand for 30 min, and separated for 30 min. The organic phase was distilled under reduced pressure (2 h) to obtain a light yellow solid, namely intermediate II (13.18 g), with a reaction yield of 90%.

[0088] (3) 14.7 g of intermediate II, 80 mL of toluene, 1.35 g of ethanolamine, and 2 g of sodium bicarbonate were added to the reaction kettle. The temperature was raised to 120° C. (1.5 h) under nitrogen protection, and the reaction was carried out for 8 h. The temperature was lowered (1 h), and 50 mL of pure water was added for washing. The mixture was stirred for 30 min, allowed to stand for 30 min, and separated for 30 min. The organic phase was dried over anhydrous magnesium sulfate and concentrated (total 2.5 h), and filtered after being stored at low temperature overnight (total 15 h) to obtain a white solid UV-152 (11.90 g). The reaction yield was 78.6%.

[0089] The total reaction time is: step (1) takes 15 hours, step (2) takes 10.5 hours, and step (3) takes 29.5 hours; a total of 50 hours, the total yield is 64.4%, and the transmittance of the finished product at 425nm is 95.3%.

[0090] Comparative Example 2

[0091] Referring to the synthetic route of Comparative Example 1, the difference from Comparative Example 1 is that the solvent used in the reaction for preparing Intermediate 1 is different:

[0092] (1) 25.5 g of cyanuric chloride and 80 mL of xylene were added to the reaction kettle in sequence, stirring was started, and the mixture was cooled to 0-5° C. in an ice-water bath (0.5 h). 30 g of ice water was added at once, and the temperature was controlled at 0-5° C. 58.8 g of 2,2,6,6-tetramethyl-4-piperidinylbutylamine was added dropwise for 2 h. After the addition was completed, 39.8 g of a 32% sodium hydroxide aqueous solution was added dropwise for 30 min. The mixture was then heated to 60° C. (0.5 h) and kept warm for 5 h. The mixture was allowed to stand for 30 min and the lower aqueous phase was removed (0.5 h). 50 g of pure water was added, stirred for 30 min, allowed to stand for 30 min, the lower aqueous phase was removed (30 min), and the organic phase was a xylene solution of intermediate 1. The solvent was removed (3 h) to obtain intermediate 1 (72.64 g) with a yield of 98%.

[0093] (2) 120 mL of cyclohexane, 10.7 g of intermediate 1, 0.6 g of molybdenum oxide, and 21 g of 70% tert-butyl hydroperoxide were added to a reaction kettle, the temperature was raised to reflux, the reaction was carried out for 5 h, the temperature was lowered, and the mixture was filtered. A saturated aqueous sodium bicarbonate solution was added to the filtrate, the mixture was stirred for 30 min, the mixture was allowed to stand for 30 min, and the mixture was separated. The organic phase was distilled under reduced pressure to obtain a light yellow solid, which was intermediate II (13.17 g). The reaction yield was 89.9%.

[0094] (3) 14.7 g of the above-mentioned light yellow solid, 80 mL of toluene, 1.35 g of ethanolamine, and 2 g of sodium bicarbonate were added to the reaction kettle. The temperature was raised to 120° C. under nitrogen protection, and the reaction was carried out for 8 h. The temperature was lowered, 50 mL of pure water was added for washing, and the mixture was stirred for 30 min. The mixture was allowed to stand for 30 min, and separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, kept at low temperature overnight, and filtered to obtain a white solid UV-152 (11.49 g). The reaction yield was 75.9%.

[0095] The total reaction time is: step (1) takes 14 hours, the experimental operation time of step (2) is basically the same as step (2) of comparative example 1, which takes 10.5 hours, and the experimental operation time of step (3) is basically the same as step (3) of comparative example 1, which takes 29.5 hours; a total of 45 hours, the total yield is 66.9%, and the transmittance of the finished product at 425nm is 98.2%.

[0096] Example 1

[0097] (1) 25.5 g of cyanuric chloride and 80 mL of xylene were added to the reaction kettle in sequence, stirring was started, and the mixture was cooled to 0-5° C. in an ice-water bath (0.5 h). 30 g of ice water was added at once, and the temperature was controlled at 0-5° C. 58.8 g of 2,2,6,6-tetramethyl-4-piperidinylbutylamine was added dropwise for 2 h. After the addition was completed, 39.8 g of a 32% sodium hydroxide aqueous solution was added dropwise for 30 min. The mixture was then heated to 60° C. (0.5 h) and kept warm for 5 h. The mixture was allowed to stand for 30 min and the lower aqueous phase was removed (0.5 h). 50 g of pure water was added, stirred for 30 min, allowed to stand for 30 min, and the lower aqueous phase was removed (30 min). The organic phase was a xylene solution of the intermediate 1. The obtained xylene solution of intermediate 1 was added to the autoclave, and then 8.4 g of ethanolamine, 21.6 g of 32% sodium hydroxide aqueous solution and 21 g of pure water were added. After nitrogen replacement, the pressure was controlled to 1.0 MPa, stirring was turned on, the temperature was raised to 160°C (1.5 h) and kept warm for 8 h, and then cooled to 50°C (1 h), and then allowed to stand to separate water (0.5 h), washed with water 3 times (3 h), dehydrated and filtered (1 h) and then desolventized (2 h) to obtain intermediate 2 (73.59 g) with a yield of 95%.

[0098] (2) After mixing 73.59 g of intermediate 2, 175 g of cyclohexane and 0.35 g of molybdenum trioxide, the mixture was heated to 110° C. (1 h) and 88.9 g of TBHP (tert-butyl hydroperoxide) was added dropwise. After 6 h of addition, the mixture was kept warm and stirred under reflux until the color of the reaction solution faded (2 h). After the synthesis reaction was completed, the mixture was cooled to 65° C. and the catalyst was filtered (cooling + filtering for a total of 1 h). A decolorizing agent was added and stirred for 1 h. The mixture was circulated and filtered for 0.5 h. The mixture was desolvated under reduced pressure (2.5 h) to obtain 86.32 g of UV-152 finished product with a yield of 86.95%.

[0099] The total reaction time is: step (1) takes 28 hours, step (2) takes 14 hours, a total of 42 hours, the total yield is 82.6%, and the transmittance of the finished product at 425nm is 98.2%.

[0100] Example 2

[0101] (1) 25.5 g of cyanuric chloride and 80 mL of xylene were added to the reaction kettle in sequence, stirring was started, and the mixture was cooled to 0-5° C. in an ice-water bath. 30 g of ice water was added at once, and the temperature was controlled at 0-5° C. 58.8 g of 2,2,6,6-tetramethyl-4-piperidinylbutylamine was added dropwise for 2 h. After the addition was completed, 39.8 g of a 32% sodium hydroxide aqueous solution was added dropwise for 30 min, and then the temperature was raised to 60° C. and kept warm for 5 h. The mixture was allowed to stand for 30 min, and the lower aqueous phase was separated. 50 g of pure water was added, stirred for 30 min, and the mixture was allowed to stand for 30 min. The lower aqueous phase was separated, and the organic phase was a xylene solution of the intermediate 1. The obtained xylene solution of intermediate 1 was added to the autoclave, and then 8.4 g of ethanolamine, 21.6 g of 32% sodium hydroxide aqueous solution, and 21 g of pure water were added. After nitrogen replacement, the pressure was controlled to 1.0 MPa, stirring was turned on, the temperature was raised to 160°C and kept warm for 8 hours, and then cooled to 50°C, allowed to stand to separate the water, washed with water 3 times, dehydrated, filtered and desolvated to obtain intermediate 2 (73.59 g) with a yield of 95%.

[0102] (2) After mixing 73.59 g of intermediate 2, 175 g of cyclohexane and 0.35 g of molybdenum trioxide, the temperature was raised to 75°C and 47 g of H2O2 was added dropwise. After 6 h of addition, the mixture was kept warm, stirred and refluxed until the color of the reaction solution faded. After the synthesis reaction was completed, the temperature was lowered to 65°C, the catalyst was filtered, and a decolorizing agent was added. After stirring for 1 h, the mixture was circulated and filtered, and desolventized to obtain 93.42 g of UV-152 finished product with a yield of 94.1%.

[0103] The experimental operation time of each step is basically the same as that of Example 1. The total reaction time is: step (1) takes 28 hours; step (2) takes 14 hours, a total of 42 hours, the total yield is 89.4%, and the transmittance of the finished product at 425nm is 99.3%.

[0104] Example 3

[0105] (1) 25.5 g of cyanuric chloride and 80 mL of toluene were added to the reaction kettle in sequence, stirring was started, and the mixture was cooled to 0-5° C. in an ice-water bath. 30 g of ice water was added at once, and the temperature was controlled at 0-5° C. 58.8 g of 2,2,6,6-tetramethyl-4-piperidinylbutylamine was added dropwise for 2 h. After the addition was completed, 39.8 g of a 32% sodium hydroxide aqueous solution was added dropwise for 30 min, and then the temperature was raised to 60° C. and kept at this temperature for 5 h. The mixture was allowed to stand for 30 min, and the lower aqueous phase was separated. 50 g of pure water was added, and the mixture was stirred for 30 min. The mixture was allowed to stand for 30 min, and the lower aqueous phase was separated. The organic phase was a toluene solution of the intermediate 1. The toluene solution of intermediate 1 obtained was added to the autoclave, and then 8.4 g of ethanolamine, 21.6 g of 32% sodium hydroxide aqueous solution and 21 g of pure water were added. After nitrogen substitution, the pressure was controlled to 1.0 MPa, stirring was started, the temperature was raised to 160°C and kept for 8 h, and then cooled to 50°C, allowed to stand to separate the water, washed with water 3 times, dehydrated, filtered and desolvated to obtain intermediate 2 (74.34 g) with a yield of 95.86%.

[0106] (2) After mixing 74.34 g of intermediate 2, 175 g of cyclohexane and 0.35 g of molybdenum trioxide, the temperature was raised to 75°C and 47 g of H2O2 was added dropwise. After 6 h of addition, the mixture was kept warm, stirred and refluxed until the color of the reaction solution faded. After the synthesis reaction was completed, the temperature was lowered to 65°C, the catalyst was filtered, and a decolorizing agent was added. After stirring for 1 h, the mixture was circulated and filtered, and desolventized to obtain 94.27 g of UV-152 finished product with a yield of 94%.

[0107] The experimental operation time of each step is basically the same as that of Example 1. The total reaction time is: step (1) takes 28 hours; step (2) takes 14 hours, a total of 42 hours, the total yield is 90.1%, and the transmittance of the finished product at 425nm is 98.7%.

[0108] Example 4

[0109] (1) 25.5 g of cyanuric chloride and 80 mL of xylene were added to the reaction kettle in sequence, stirring was started, and the mixture was cooled to 0-5° C. in an ice-water bath. 30 g of ice water was added at once, and the temperature was controlled at 0-5° C. 58.8 g of 2,2,6,6-tetramethyl-4-piperidinylbutylamine was added dropwise for 2 h. After the addition was completed, 39.8 g of a 32% sodium hydroxide aqueous solution was added dropwise for 30 min, and then the temperature was raised to 60° C. and kept warm for 5 h. The mixture was allowed to stand for 30 min, and the lower aqueous phase was separated. 50 g of pure water was added, and the mixture was stirred for 30 min. The mixture was allowed to stand for 30 min, and the lower aqueous phase was separated. The organic phase was a xylene solution of the intermediate 1. The obtained xylene solution of intermediate 1 was added to the autoclave, and then 8.4 g of ethanolamine, 21.6 g of 32% sodium hydroxide aqueous solution, and 21 g of pure water were added. After nitrogen replacement, the pressure was controlled to 1.0 MPa, stirring was turned on, the temperature was raised to 160°C and kept warm for 8 hours, and then cooled to 50°C, allowed to stand to separate the water, washed with water 3 times, dehydrated, filtered and desolvated to obtain intermediate 2 (73.59 g) with a yield of 95%.

[0110] (2) After mixing 73.59 g of intermediate 2, 175 g of cyclohexane and 0.35 g of magnesium hydroxide, the temperature was raised to 75°C and 47 g of H2O2 was added dropwise. After 6 h of addition, the mixture was kept warm, stirred and refluxed until the color of the reaction solution faded. After the synthesis reaction was completed, the temperature was lowered to 65°C, the catalyst was filtered, and a decolorizing agent was added. After stirring for 1 h, the mixture was filtered in a cycle and desolvated under reduced pressure to obtain 74.72 g of UV-152 finished product with a yield of 75.26%.

[0111] The experimental operation time of each step is basically the same as that of Example 1. The total reaction time is: step (1) takes 28 hours; step (2) takes 14 hours, a total of 42 hours, the total yield is 71.5%, and the transmittance of the finished product at 425nm is 98.1%.

[0112] Example 5

[0113] (1) 25.5 g of cyanuric chloride and 80 mL of xylene were added to the reaction kettle in sequence, stirring was started, and the mixture was cooled to 0-5° C. in an ice-water bath. 30 g of ice water was added at once, and the temperature was controlled at 0-5° C. 58.8 g of 2,2,6,6-tetramethyl-4-piperidinylbutylamine was added dropwise for 2 h. After the addition was completed, 39.8 g of a 32% sodium hydroxide aqueous solution was added dropwise for 30 min, and then the temperature was raised to 60° C. and kept warm for 5 h. The mixture was allowed to stand for 30 min, and the lower aqueous phase was separated. 50 g of pure water was added, stirred for 30 min, and the mixture was allowed to stand for 30 min. The lower aqueous phase was separated, and the organic phase was a xylene solution of the intermediate 1. The obtained xylene solution of intermediate 1 was added to the autoclave, and then 8.4 g of ethanolamine, 21.6 g of 32% sodium hydroxide aqueous solution, and 21 g of pure water were added. After nitrogen replacement, the pressure was controlled to 1.0 MPa, stirring was turned on, the temperature was raised to 160°C and kept warm for 8 hours, and then cooled to 50°C, allowed to stand to separate the water, washed with water 3 times, dehydrated, filtered and desolvated to obtain intermediate 2 (73.59 g) with a yield of 95%.

[0114] (2) After mixing 73.59 g of intermediate 2, 175 g of cyclohexane and 0.76 g of ferrous chloride, the temperature was raised to 75 ° C and 47 g of H2O2 was added dropwise. After 6 h of addition, the mixture was kept warm, stirred and refluxed until the color of the reaction solution faded. After the synthesis reaction was completed, the temperature was lowered to 65 ° C, the catalyst was filtered, and a decolorizing agent was added. After stirring for 1 h, the mixture was circulated and filtered, and desolventized to obtain 96.25 g of UV-152 finished product with a yield of 96.95%.

[0115] The experimental operation time of each step is basically the same as that of Example 1. The total reaction time is: step (1) takes 28 hours; step (2) takes 14 hours, a total of 42 hours, the total yield is 92.1%, and the transmittance of the finished product at 425nm is 99.3%.

[0116] Example 6

[0117] (1) 25.5 g of cyanuric chloride and 80 mL of xylene were added to the reaction kettle in sequence, stirring was started, and the mixture was cooled to 0-5° C. in an ice-water bath. 30 g of ice water was added at once, and the temperature was controlled at 0-5° C. 58.8 g of 2,2,6,6-tetramethyl-4-piperidinyl-butylamine was added dropwise for 2 h. After the addition was completed, 39.8 g of a 32% sodium hydroxide aqueous solution was added dropwise for 30 min, and then the temperature was raised to 60° C. and kept at this temperature for 5 h. The mixture was allowed to stand for 30 min, and the lower aqueous phase was separated. 50 g of pure water was added, and the mixture was stirred for 30 min. The mixture was allowed to stand for 30 min, and the lower aqueous phase was separated. The organic phase was a xylene solution of the intermediate 1. The obtained xylene solution of intermediate 1 was added to the autoclave, and then 8.4 g of ethanolamine, 21.6 g of 32% sodium hydroxide aqueous solution, and 21 g of pure water were added. After nitrogen replacement, the pressure was controlled to 1.0 MPa, stirring was turned on, the temperature was raised to 160°C and kept warm for 8 h, and then cooled to 50°C, allowed to stand to separate the water, washed with water 3 times, dehydrated, filtered and desolvated to obtain intermediate 2 (73.59 g) with a yield of 95%.

[0118] (2) After mixing 73.59 g of intermediate 2, 215 g of cyclohexane and 0.35 g of molybdenum trioxide, the temperature was raised to 110° C. and 88.9 g of TBHP (tert-butyl hydroperoxide) was added dropwise. After 6 h of addition, the mixture was kept warm, stirred and refluxed until the color of the reaction solution faded. After the synthesis reaction was completed, the temperature was lowered to 65° C., the catalyst was filtered, and a decolorizing agent was added. After stirring for 1 h, the mixture was circulated and filtered, and desolventized to obtain 90.3 g of UV-152 finished product with a yield of 90.95%.

[0119] The experimental operation time of each step is basically the same as that of Example 1. The total reaction time is: step (1) takes 28 hours; step (2) takes 14 hours, a total of 42 hours, the total yield is 86.4%, and the transmittance of the finished product at 425nm is 99.4%.

[0120] Example 7

[0121] (1) Add 120 mL of acetone to the reaction kettle, cool to below 0°C in an ice-water bath, add 18.4 g of cyanuric chloride, and dropwise add 21.2 g of 2,2,6,6-tetramethyl-4-piperidinylbutylamine at a temperature of 0 to 5°C for 3 h; then slowly dropwise add 13.1 g of liquid alkali (32% by mass sodium hydroxide aqueous solution) at a temperature of 0 to 5°C for 1 h; after the addition is completed, heat to reflux, react for 6 h, cool, filter, and add 600 mL of water to the filtrate to precipitate a white product, namely, intermediate 1 (48.69 g), with a reaction yield of 91%.

[0122] (2) In an autoclave, 47.41 g of intermediate 1, 80 mL of xylene, 8.4 g of ethanolamine, 21.6 g of a 32% sodium hydroxide aqueous solution, and 21 g of pure water were added. After nitrogen replacement, the pressure was controlled to 1.0 MPa, stirring was turned on, the temperature was raised to 160°C (1.5 h) and kept warm for 8 h, and then cooled to 50°C (1 h), and then allowed to stand to separate water (0.5 h), washed with water 3 times (3 h), dehydrated and filtered (2 h) and then desolventized (2 h) to obtain intermediate 2 (47.1 g) with a yield of 95%.

[0123] (3) After mixing 73.59 g of intermediate 2, 175 g of cyclohexane and 0.35 g of molybdenum trioxide, the temperature was raised to 110° C. and 88.9 g of TBHP (tert-butyl hydroperoxide) was added dropwise. After 6 h of addition, the mixture was kept warm, stirred and refluxed until the color of the reaction solution faded. After the synthesis reaction was completed, the temperature was lowered to 65° C., the catalyst was filtered, and a decolorizing agent was added. After stirring for 1 h, the mixture was circulated and filtered, and desolventized to obtain 86.32 g of UV-152 finished product with a yield of 86.95%.

[0124] The total reaction time is: the experimental operation time of step (1) is basically the same as step (1) of comparative example 1, which takes 15 hours; the experimental operation time of step (2) is 17 hours, and the experimental operation time of step (3) is basically the same as step (2) of example 1, which takes 14 hours, a total of 46 hours, the total yield is 75.17%, and the transmittance of the finished product at 425nm is 98.6%.

[0125] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a hindered amine light stabilizer as shown in Formula I, comprising the following steps: (1) Compound I-2 undergoes a substitution reaction with an alcohol amine represented by formula I-3 to obtain compound I-4; (2) Compound I-4 is subjected to an alkoxylation reaction with cyclohexane in the presence of an oxidant to obtain a hindered amine light stabilizer represented by formula I. in, In compound I-2, compound I-4 and formula I, R is selected from hydrogen and C1-C10 alkyl; in formula I-3, compound I-4 and formula I, L is selected from C1-C10 alkylene.

2. The method according to claim 1, It is characterized in that R is selected from hydrogen, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl or isohexyl, preferably n-butyl, isobutyl or tert-butyl; L is selected from methylene, ethylene, propylene, isopropylene, butylene, isobutylene or tert-butylene, preferably methylene, ethylene or propylene; Preferably, R is n-butyl and L is ethylene; Preferably, the compound of formula I has the structure shown below:

3. The method according to claim 1 or 2, It is characterized in that Compound I-2 is prepared by a method comprising the following steps: (S1) reacting cyanuric chloride with compound I-1 in an aromatic hydrocarbon solvent to obtain an organic phase containing compound I-2, Wherein, R is defined as in claim 1 or 2.

4. The method according to claim 3, It is characterized in that In step (S1), the aromatic hydrocarbon solvent includes one or more of toluene, xylene, chlorobenzene, trimethylolbenzene, and methylethylbenzene; preferably includes toluene and / or xylene; and / or, The molar ratio of cyanuric chloride to the aromatic hydrocarbon solvent is 1:(4-20); and / or, The molar ratio of cyanuric chloride to compound I-1 is 1:(1.8-2.2); and / or, The reaction temperature is 50-70°C.

5. The method according to claim 3 or 4, It is characterized in that In step (S1), water is added to the reaction system before and / or after the reaction of cyanuric chloride and compound I-1; Preferably, the volume ratio of the aromatic hydrocarbon to water is (0.8-1.5):1; Preferably, after the reaction, the aqueous phase in the reaction system is removed to obtain an organic phase containing compound I-2; Preferably, the organic phase containing compound I-2 is directly used in step (1) to carry out a substitution reaction with the alcoholamine represented by formula I-3.

6. The method according to any one of claims 1 to 5, It is characterized in that In step (1): The molar ratio of the alcohol amine shown in formula I-3 to compound I-2 is (0.8-1.5):1, preferably (0.8-1.2):1; and / or the temperature of the substitution reaction is 100-180°C, preferably 150-180°C; and / or the time of the substitution reaction is 6-18h.

7. The method according to any one of claims 1 to 6, It is characterized in that In step (1): The substitution reaction is carried out in an aromatic organic solvent, wherein the aromatic organic solvent includes one or more of toluene, xylene, chlorobenzene, trimethylolbenzene, and methylethylbenzene; and / or, The substitution reaction is carried out in the presence of an acid-binding agent, and the acid-binding agent includes one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

8. The method according to any one of claims 1 to 7, It is characterized in that In step (2): The oxidant includes a peroxide, preferably one or more of tert-butyl hydroperoxide, hydrogen peroxide, and peracetic acid; and / or the molar ratio of the oxidant to compound I-4 is (4-15):1, preferably (4-10):

1.

9. The method according to any one of claims 1 to 8, It is characterized in that In step (2), the alkoxylation reaction is carried out in the presence of a catalyst, and the catalyst includes one or more of molybdenum trioxide, magnesium oxide, magnesium hydroxide, sodium carbonate, sodium chloride, cuprous chloride, ferric chloride, and ferrous chloride; Preferably, the molar ratio of the catalyst to compound I-4 is (0.01-0.1):

1.

10. The method according to any one of claims 1 to 9, It is characterized in that In step (2), the molar ratio of cyclohexane to compound I-4 is (12-20):1; and / or, the temperature of the alkoxylation reaction is 70-130°C; and / or, Step (2) further comprises: after the alkoxylation reaction is completed, adding a decolorizing agent to the reaction system; Preferably, after adding the decolorizing agent, solid-liquid separation is performed to obtain a liquid phase; the liquid phase is decompressed to remove the solvent to obtain the hindered amine light stabilizer shown in formula I.

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