Organic silicon modification-based hindered amine light stabilizer and preparation method thereof

Abstract

The preparation method specifically comprises the following steps: under the protection of nitrogen, putting hydroxyethyl piperidinol, a catalyst and an organic solvent into a reaction container, dropwise adding an organic solvent of dichlorodiphenyl silane into a reaction system, and after dropwise adding is completed, carrying out a reaction for 2-4 hours, so as to obtain the hindered amine light stabilizer based on organic silicon modification. After reacting for a period of time at a certain temperature, filtering, washing, decolorizing and filtering to obtain the hindered amine light stabilizer based on organic silicon modification. The light stabilizer has the light stability of hindered amine and the high temperature resistance of organic silicon.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material modification additives, and particularly relates to an organosilicon-modified hindered amine light stabilizer and a preparation method thereof. Background Art

[0002] Hindered amine light stabilizers (HALS) are widely used to improve the UV aging resistance of polymer materials, but their mobility and thermal stability in high-temperature or harsh environments remain limited. Existing technologies have partially improved their performance through chemical modification (such as the introduction of long-chain alkyl or polar groups), but they still face problems such as poor compatibility with polymers and insufficient processing stability.

[0003] Due to their unique Si-O bond structure, organosilicon compounds possess high thermal stability, hydrophobicity, and flexibility, compensating for the shortcomings of traditional HALS. For example, the heat resistance of the silane-oxygen bond (>300°C) enhances the stability of HALS in high-temperature processing environments; the low surface energy of organosilicon reduces HALS migration and extends the material's service life; and the introduction of silane groups improves compatibility with polar polymers (such as PC and ABS), expanding its application scenarios. However, existing research on the combination of HALS and organosilicon is limited, and reaction pathway design presents challenges (such as the selective reaction of silane coupling agents and byproduct control). Summary of the Invention

[0004] To solve the above problems, the present invention discloses a hindered amine light stabilizer based on organosilicon modification and a preparation method thereof. Through the directional condensation reaction of hydroxyethylpiperidinol and dichlorodiphenylsilane, a new compound with both hindered amine light stability and organosilicon heat resistance is constructed.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A silicone-modified hindered amine light stabilizer having a structure as shown in Formula I:

[0007] .

[0008] The present invention also provides a method for preparing a silicone-modified hindered amine light stabilizer, the synthesis process route being:

[0009] .

[0010] As an improvement of the present invention, the specific preparation steps of the synthesis process are as follows:

[0011] S1. Under nitrogen protection, hydroxyethyl piperidinol, a catalyst, and an organic solvent are added to a reaction vessel;

[0012] S2. An organic solvent is added to dichlorodiphenylsilane to prepare a mixed solution of dichlorodiphenylsilane and an organic solvent;

[0013] S3 is added dropwise to the reaction system of step S1 a mixed solution of dichlorodiphenylsilane and an organic solvent configured in step S2, and the reaction is carried out after completion of the addition;

[0014] S4. After the reaction is completed, the product is filtered, washed with water, decolorized, and filtered to obtain a silicone-modified hindered amine light stabilizer.

[0015] As an improvement of the present invention, the mass of the organic solvent in step S1 is 1 to 5 times the mass of hydroxyethylpiperidinol, and the mass of the organic solvent in step S2 is 1 to 4 times the mass of dichlorodiphenylsilane.

[0016] As an improvement of the present invention, the molar ratio of dichlorodiphenylsilane in step S2 to hydroxyethylpiperidinol in step S1 is 1:1-1.5, and the molar ratio of dichlorodiphenylsilane in step S2 to the catalyst in step S1 is 1:2-2.05.

[0017] As an improvement of the present invention, the organic solvent in step S1 and step S2 is any one of benzene, toluene, xylene, dioxane, mesitylene, and N,N-dimethylformamide.

[0018] As an improvement of the present invention, the catalyst in step S1 is any one of triethylamine, pyridine, N,N-diisopropylethylamine, 4-dimethylaminopyridine, and triethanolamine.

[0019] As an improvement of the present invention, in step S3, the dropping temperature is 20-40° C., the reaction temperature is 60-160° C., and the reaction time is 6-24 hours.

[0020] The beneficial effects of the present invention are:

[0021] This invention utilizes organosilicon (dichlorodiphenylsilane) to precisely modify the hindered amine structure. The resulting product combines the synergistic effects of two stabilizers: the siloxane segments impart enhanced thermal stability, while the hindered amine groups maintain excellent light-harvesting and free-radical quenching capabilities. Furthermore, the hydrophobicity of the diphenylsilane groups and the polarity of the piperidine rings form an amphiphilic structure, enhancing compatibility with polymer materials. This invention overcomes the limitations of traditional HALS while simplifying the process (for example, using triethylamine as an acid-binding agent for a one-step synthesis), avoiding complex post-processing, and aligning with the trend toward green chemistry. The technological gap in this area, coupled with market demand (such as the growing demand for weather-resistant high-end engineering plastics), forms the basis for this innovation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the infrared spectrum of the product prepared in Example 1. DETAILED DESCRIPTION

[0023] The present invention will be further explained below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0024] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0025] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0026] Example 1

[0027] Under nitrogen protection, 30.12 g of hydroxyethylpiperidinol, 15.89 g of pyridine, and 60 g of toluene were added to a 500 mL four-necked flask, and the temperature was raised to 40 ° C. A mixed solution of dichlorodiphenylsilane and toluene (25.3 g + 50 g) was added dropwise. After the addition was complete, the temperature was raised to 110 ° C. and the reaction was carried out for 12 hours. The temperature was then lowered to 30 ° C. and pyridine hydrochloride was removed by filtration. Then, 50 g of pure water was added to wash three times, and 0.5 g of activated carbon was added for decolorization. The mixture was filtered and distilled under reduced pressure to obtain 44.60 g of a light yellow solid with a product yield of 92.66% and Mn / Mw=1.2.

[0028] The infrared spectrum of the product prepared in Example 1 of the present invention is as follows Figure 1 As shown in the infrared spectrum, it can be seen that at 1121cm -1 The stretching vibration absorption peak of -Si-O is at 3000cm -1 The left and right sides are the characteristic absorption peaks of benzene ring, 1268cm -1 The stretching vibration peak of -CN in the hydroxyethylpiperidinol structure is 1150cm -1 The peak is the stretching vibration of CO.

[0029] Example 2

[0030] Under nitrogen protection, 30.12 g of hydroxyethylpiperidinol, 20.32 g of triethylamine, and 60 g of toluene were added to a 500 mL four-necked flask, and the temperature was raised to 40 ° C. A mixed solution of dichlorodiphenylsilane and toluene (25.3 g + 50 g) was added dropwise. After the addition was complete, the temperature was raised to 90 ° C. and the reaction was carried out for 16 hours. The temperature was then lowered to 30 ° C. and triethylamine hydrochloride was removed by filtration. Then, 50 g of pure water was added to wash three times, and 0.5 g of activated carbon was added for decolorization. The mixture was filtered and distilled under reduced pressure to obtain 42.57 g of a light yellow solid with a product yield of 88.45% and Mn / Mw=1.42.

[0031] Example 3

[0032] Under nitrogen protection, 30.12 g of hydroxyethylpiperidinol, 15.89 g of pyridine, and 60 g of dioxane were added to a 500 mL four-necked flask, and the temperature was raised to 30 ° C. A mixed solution of dichlorodiphenylsilane and dioxane (25.3 g + 50 g) was added dropwise. After the addition was complete, the temperature was raised to 101 ° C. and the reaction was carried out for 12 hours. The temperature was then lowered to 30 ° C. and pyridine hydrochloride was removed by filtration. Then, 50 g of pure water was added to wash three times, and 0.5 g of activated carbon was added for decolorization. The mixture was filtered and distilled under reduced pressure to obtain 44.05 g of a light yellow solid with a product yield of 91.53% and Mn / Mw=1.3.

[0033] Example 4

[0034] Under nitrogen protection, 120.5g of hydroxyethylpiperidinol, 63.54g of pyridine, and 200g of toluene were added to a 1000mL four-necked flask, and the temperature was raised to 40°C. A mixed solution of dichlorodiphenylsilane and toluene (101.6g+150g) was added dropwise. After the addition was complete, the temperature was raised to 110°C and the reaction was carried out for 12 hours. The temperature was then lowered to 30°C and the pyridine hydrochloride was removed by filtration. The mixture was then washed three times with 200g of pure water, and 2g of activated carbon was added for decolorization. The mixture was filtered and distilled under reduced pressure to give 179.86g of a light yellow solid with a product yield of 93.42% and Mn / Mw=1.23.

[0035] Example 5

[0036] Under nitrogen protection, 104.44g of hydroxyethylpiperidinol, 63.54g of pyridine, and 200g of toluene were added to a 1000mL four-necked flask, and the temperature was raised to ℃, and a mixed solution of dichlorodiphenylsilane and toluene (101.6g+150g) was added dropwise. After the addition was complete, the temperature was raised to 110℃ and the reaction was carried out for 12 hours. The temperature was then lowered to 30℃ and the pyridine hydrochloride was removed by filtration. Then, 200g of pure water was added, and the mixture was washed three times. 2g of activated carbon was added for decolorization, filtered, and distilled under reduced pressure to obtain 157.58g of a light yellow solid with a product yield of 93.56% and Mn / Mw=1.4.

[0037] Example 6

[0038] Under nitrogen protection, 120.5g of hydroxyethylpiperidinol, 63.54g of pyridine, and 200g of xylene were added to a 1000mL four-necked flask, and the temperature was raised to 40°C. A mixed solution of dichlorodiphenylsilane and xylene (101.6g+150g) was added dropwise. After the addition was complete, the temperature was raised to 120°C and the reaction was carried out for 12 hours. The temperature was then lowered to 30°C and the pyridine hydrochloride was removed by filtration. The mixture was then washed three times with 200g of pure water, and 2g of activated carbon was added for decolorization. The mixture was filtered and distilled under reduced pressure to give 181.21g of a light yellow solid with a product yield of 94.12% and Mn / Mw=1.26.

[0039] Example 7

[0040] Under nitrogen protection, 215.31g of hydroxyethylpiperidinol, 135.49g of triethylamine, and 500g of dioxane were added to a 2000mL four-necked flask, and the temperature was raised to 40°C. A mixed solution of dichlorodiphenylsilane and dioxane (169.51g + 300g) was added dropwise. After the addition was complete, the temperature was raised to 90°C and the reaction was carried out for 16 hours. The temperature was then lowered to 30°C and the triethylamine hydrochloride was removed by filtration. 400g of pure water was then added for washing three times, and 3g of activated carbon was added for decolorization. The mixture was filtered and distilled under reduced pressure to give 307.12g of a light yellow solid with a product yield of 91.42% and Mn / Mw=1.18.

[0041] Example 8

[0042] Under nitrogen protection, 215.31g of hydroxyethylpiperidinol, 105.91g of pyridine, and 500g of dioxane were added to a 2000mL four-necked flask, and the temperature was raised to 40°C. A mixed solution of dichlorodiphenylsilane and dioxane (169.51g + 300g) was added dropwise. After the addition was complete, the temperature was raised to 100°C and reacted for 16 hours. The temperature was then lowered to 30°C and triethylamine hydrochloride was removed by filtration. 400g of pure water was then added for washing three times, and 3g of activated carbon was added for decolorization. The mixture was filtered and distilled under reduced pressure to give 318.41g of a light yellow solid with a product yield of 94.78% and Mn / Mw=1.16.

[0043] UV accelerated aging test

[0044] The product obtained in Example 8 and light stabilizer 622 were added in a ratio of 0.5% by mass, and antioxidant 1010 and PP were added at a ratio of 0.1%. The mixture was thoroughly mixed in a 50°C high-speed mixer (speed of 800-1200 rpm) and then added to a twin-screw extruder (aspect ratio of 40:1, screw speed of 200-300 rpm) for melt extrusion and granulation. The mixture was then injection molded into standard test specimens in an injection molding machine. After injection molding, the specimens were placed in an environment of 23°C and 50% RH for 24 hours to eliminate internal stress.

[0045] The test specimens were subjected to an accelerated UV aging test. This test was conducted in accordance with ASTM G154, using a UVB-313 UV light source (peak wavelength 313 nm) and the following test conditions:

[0046] Irradiance: 0.71 W / m²@340nm;

[0047] Temperature control: (1) Blackboard temperature during light phase: 60°C, (2) Blackboard temperature during dark phase: 50°C;

[0048] Cycle period: (1) UV irradiation: 480 minutes, (2) condensation humidification: 240 minutes;

[0049] Total test duration: three levels: 100 hours, 200 hours, and 300 hours.

[0050] The test results are shown in the following table:

[0051]

[0052] As shown in the table, after UV-accelerated aging, the protective efficiency of the silicone-modified light stabilizer > Light Stabilizer 622 was higher than that of the pure PP sample. The mechanical properties of the pure PP sample collapsed after 200 hours (tensile strength <15 MPa, elongation at break <30%). The sample with Light Stabilizer 622 reached the industrial failure threshold at 300 hours (tensile strength >15 MPa, elongation at break >30%). However, the sample with the silicone-modified light stabilizer used in this experiment maintained its usability after 300 hours (tensile strength >25 MPa, elongation at break >80%). This is primarily due to the silicone group's enhanced compatibility with PP, which reduces stabilizer migration. Furthermore, the silicone group dissipates UV energy through Si-O bonds, reducing the probability of photodegradation of the PP backbone.

[0053] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made on the basis of the above embodiments, and these improvements and modifications all fall within the scope of protection of the claims of the present invention.

Claims

1. A silicone-modified hindered amine light stabilizer, characterized in that: Having the structure shown in Formula I: 。 2. A method for preparing a silicone-modified hindered amine light stabilizer according to claim 1, characterized in that: The synthetic process route is: 。 3. The method for preparing a silicone-modified hindered amine light stabilizer according to claim 2, wherein: The specific preparation steps are as follows: S1. Under nitrogen protection, hydroxyethyl piperidinol, a catalyst, and an organic solvent are added to a reaction vessel; S2. An organic solvent is added to dichlorodiphenylsilane to prepare a mixed solution of dichlorodiphenylsilane and an organic solvent; S3 is added dropwise to the reaction system of step S1 a mixed solution of dichlorodiphenylsilane and an organic solvent configured in step S2, and the reaction is carried out after completion of the addition; S4. After the reaction is completed, the product is filtered, washed with water, decolorized, and filtered to obtain a silicone-modified hindered amine light stabilizer.

4. The method for preparing a silicone-modified hindered amine light stabilizer according to claim 3, wherein: The mass of the organic solvent in step S1 is 1 to 5 times the mass of hydroxyethylpiperidinol, and the mass of the organic solvent in step S2 is 1 to 4 times the mass of dichlorodiphenylsilane.

5. The method for preparing a silicone-modified hindered amine light stabilizer according to claim 3, wherein: The molar ratio of the dichlorodiphenylsilane in step S2 to the hydroxyethylpiperidinol in step S1 is 1:1-1.5, and the molar ratio of the dichlorodiphenylsilane in step S2 to the catalyst in step S1 is 1:2-2.

05.

6. The method for preparing a silicone-modified hindered amine light stabilizer according to claim 3, wherein: The organic solvent in step S1 and step S2 is any one of benzene, toluene, xylene, dioxane, mesitylene, and N,N-dimethylformamide.

7. The method for preparing a silicone-modified hindered amine light stabilizer according to claim 3, wherein: The catalyst in step S1 is any one of triethylamine, pyridine, N,N-diisopropylethylamine, 4-dimethylaminopyridine, and triethanolamine.

8. The method for preparing a silicone-modified hindered amine light stabilizer according to claim 3, wherein: In step S3, the dropping temperature is 20-40° C., the reaction temperature is 60-160° C., and the reaction time is 6-24 hours.

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