Maleic anhydride stabilizers and methods of use and application thereof

Abstract

The present application relates to the technical field of maleic anhydride production, and discloses a maleic anhydride stabilizer, application and use method thereof.The maleic anhydride stabilizer comprises a light stabilizer 15-50%, an antioxidant 15-50% and an acyl chloride reagent 20-70% by mass percentage.The maleic anhydride stabilizer has the characteristics of long stabilization period and good stabilization effect, can effectively improve the high-temperature stability of the maleic anhydride product, reduce the high-temperature color number of the maleic anhydride product, meet the needs of producing high-quality maleic anhydride products, and further improve the appearance quality of downstream products.The use method of the maleic anhydride stabilizer has the characteristics of simple operation and strong practicability, and the device has the characteristics of low energy consumption, low cost, environmental protection, and can be used for large-scale maleic anhydride stabilization treatment.

Description

Technical Field

[0001] This invention relates to the field of maleic anhydride production technology, specifically to a maleic anhydride stabilizer and its application and usage method. Background Technology

[0002] Maleic anhydride is a commonly used and important basic organic chemical raw material, ranking as the world's third largest acid anhydride raw material after acetic anhydride and phthalic anhydride. Maleic anhydride is mainly used in the production of unsaturated polyester resins (UPR) and alkyd resins. In addition, maleic anhydride can be used to produce a series of widely used fine chemicals, including 1,4-butanediol (BDO), tetrahydrofuran (THF), γ-butyrolactone (GBL), maleic acid, fumaric acid, and tetrahydroanhydride, which have broad applications in pesticides, pharmaceuticals, coatings, inks, lubricant additives, food additives, and surfactants.

[0003] The melt color (platinum-cobalt color number) of maleic anhydride and its melt color after heating are important indicators of maleic anhydride products. The level of its melt color number directly affects the appearance quality of downstream products, and high-grade resin products have more stringent requirements for the stability of the high-temperature color number of maleic anhydride.

[0004] The discoloration of maleic anhydride is a slow chemical change process, related to its poor stability and the presence of impurities. Maleic anhydride is highly reactive, readily absorbing water and hydrolyzing. It readily reacts with strong oxidizing agents, strong reducing agents, strong acids, strong bases, and alkali metals, resulting in poor thermal stability and easy discoloration upon heating. Generally, the color number exceeds 100 after heating at 140℃ for 2 hours, and in severe cases, it can reach over 200. The structural formula of maleic anhydride contains a carbonyl group. After hydrolysis to maleic acid, the adjacent position of the carbonyl group is a hydroxyl group, forming a hydrogen-bonded chelate ring. These compounds exhibit strong ultraviolet absorption, leading to the light instability of maleic anhydride. Maleic anhydride can undergo a polymerization reaction with acrylic acid, producing a yellow product. Higher temperatures (70-80℃) can accelerate the polymerization reaction. Furthermore, because maleic anhydride is weakly acidic, it can corrode equipment during production, refining, and storage, resulting in trace amounts of rust in the product. Rust itself is reddish-brown. Many factors lead to poor stability of maleic anhydride under high temperature conditions or during long-term storage and transportation, resulting in poor color of the final product and failure to meet the requirements of downstream customers.

[0005] Therefore, existing maleic anhydride production technologies often include a stabilization treatment step, which involves adding an appropriate amount of maleic anhydride color stabilizer. This can improve the thermal stability of the maleic anhydride product to some extent and extend its shelf life. However, existing maleic anhydride color stabilizers offer poor protection for the product at high temperatures and cannot meet the requirements for producing high-quality maleic anhydride products. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem that existing maleic anhydride color stabilizers have poor protective effects on maleic anhydride products at high temperatures, failing to meet the needs of producing high-quality maleic anhydride products. This invention provides a maleic anhydride stabilizer, its application, and its usage method. This maleic anhydride stabilizer has the characteristics of long stability period and good stabilization effect on maleic anhydride products, effectively improving the high-temperature stability of maleic anhydride products, reducing the high-temperature color of maleic anhydride products, meeting the needs of producing high-quality maleic anhydride products, and thus improving the appearance quality of downstream products.

[0007] Light stabilizers selectively absorb or reflect ultraviolet rays from sunlight, thereby interrupting the photoreaction of the target substance. Antioxidants inhibit or delay the oxidation reaction of the target substance. Acyl chloride reagents are chemically active and preferentially react with impurities such as water. The applicant of this invention has discovered that, under high-temperature processing conditions or long-term storage environments, adding a maleic anhydride stabilizer obtained by combining light stabilizers, antioxidants, and acyl chloride reagents to refined maleic anhydride products allows the light stabilizer, antioxidants, and acyl chloride reagents to work synergistically to stabilize the product. The light stabilizer absorbs or reflects ultraviolet rays and interrupts the photoreaction of maleic anhydride; the antioxidant inhibits the oxidation reaction of maleic anhydride; and the active carbonyl chloride functional groups of the acyl chloride reagents preferentially oxidize maleic anhydride or preferentially react with impurities in maleic anhydride, resulting in better protection of maleic anhydride.

[0008] The mechanism of action of this invention: The active functional groups such as carbonyl groups in the maleic anhydride stabilizer obtained by compounding light stabilizers, antioxidants and acyl chloride reagents are electrophilic, which can make the maleic anhydride stabilizer preferentially undergo oxidation reaction with maleic anhydride, cut off or inhibit the light reaction and oxidation reaction of maleic anhydride, and ultimately play a role in stabilizing the color of maleic anhydride. This can greatly improve the high temperature stability of maleic anhydride products and the appearance quality of downstream products.

[0009] To achieve the above objectives, the first aspect of the present invention provides a maleic anhydride stabilizer, which, by mass percentage, comprises 15-50% light stabilizer, 15-50% antioxidant, and 20-70% acyl chloride reagent.

[0010] A second aspect of the present invention provides the application of a maleic anhydride stabilizer in the stabilization treatment of maleic anhydride products.

[0011] A third aspect of the present invention provides a method for using a maleic anhydride stabilizer, the method comprising: mixing a light stabilizer, an antioxidant, and an acyl chloride reagent at room temperature to obtain a maleic anhydride stabilizer; and then mixing the maleic anhydride stabilizer with maleic anhydride.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The maleic anhydride stabilizer provided by the present invention has the characteristics of long stabilization time and good stabilization effect, which can effectively improve the high temperature stability of maleic anhydride products, reduce the high temperature color number of maleic anhydride products, meet the needs of producing high-quality maleic anhydride products, and thus improve the appearance quality of downstream products.

[0014] (2) The method of using maleic anhydride stabilizer provided by the present invention has the characteristics of simple operation and strong practicality. Moreover, the device has low energy consumption, low cost and environmental protection, and can be used for large-scale maleic anhydride stabilization treatment, which is convenient for industrial production application.

[0015] (3) The quality indicators of the maleic anhydride products treated with the maleic anhydride stabilizer provided by this invention meet the requirements of the national standard GB / T3676-2020 or Zhejiang manufacturing standard T / ZZB 1198-2019. Among them, the color number of the solid maleic anhydride product meets the requirements of 65℃ melting color (platinum-cobalt color number) ≤20 and molten color (platinum-cobalt color number) ≤50 after heating to 140℃ and holding for 2 hours; the color number of the liquid maleic anhydride product meets the requirements of 65℃ melting color (platinum-cobalt color number) ≤20 and molten color (platinum-cobalt color number) ≤40 after heating to 140℃ and holding for 2 hours. After two months of retesting, the purity of the maleic anhydride product decreased slightly and the high-temperature color increased slightly, but it still meets the requirements of the national standard GB / T3676-2020 or Zhejiang manufacturing standard T / ZZB 1198-2019, which can meet the needs of producing high-quality maleic anhydride products. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating a preferred embodiment of the use of the maleic anhydride stabilizer of the present invention.

[0017] Explanation of reference numerals in the attached figures

[0018] 1- Refined maleic anhydride storage tank; 2- Maleic anhydride stabilization treatment tank; 3- Dosing and filtration tank.

[0019] 4-Return pipe, 5-Return pump, 6-Mastic anhydride feed pump. Detailed Implementation

[0020] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0021] According to a first aspect of the present invention, the present invention provides a maleic anhydride stabilizer, which comprises, by mass percentage, 15-50% light stabilizer, 15-50% antioxidant, and 20-70% acyl chloride reagent.

[0022] In this invention, the maleic anhydride stabilizer obtained by compounding 15-50% light stabilizer, 15-50% antioxidant, and 20-70% acyl chloride reagent has the characteristics of long stabilization time and good stabilization effect. It can effectively improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, meet the needs of producing high-quality maleic anhydride products, and thus improve the appearance quality of downstream products.

[0023] According to a preferred embodiment of the present invention, the maleic anhydride stabilizer comprises, by mass percentage, 20-40% light stabilizer, 20-40% antioxidant, and 30-60% acyl chloride reagent. By optimizing the mass percentages of the light stabilizer, antioxidant, and acyl chloride reagent, the resulting maleic anhydride stabilizer, obtained by compounding 20-40% light stabilizer, 20-40% antioxidant, and 30-60% acyl chloride reagent, exhibits longer stabilization time and better stabilization effect. This further improves the high-temperature stability of maleic anhydride products, reduces the high-temperature color number of maleic anhydride products, better meets the needs of producing high-quality maleic anhydride products, and thus effectively improves the appearance quality of downstream products.

[0024] According to a preferred embodiment of the present invention, the light stabilizer is selected from at least one of the following: 4-tert-butylphenyl salicylate, 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole, zinc oxide, and iron oxide. Using the aforementioned embodiment, the resulting light stabilizer absorbs or reflects ultraviolet light and interrupts the photoreaction of maleic anhydride, effectively improving the high-temperature stability of maleic anhydride products, reducing the high-temperature color number of maleic anhydride products, meeting the needs of producing high-quality maleic anhydride products, and thus improving the appearance quality of downstream products.

[0025] According to a particularly preferred embodiment of the present invention, the light stabilizer is selected from any two of the following: 4-tert-butylphenyl salicylate, 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole, zinc oxide, and iron oxide. By employing the aforementioned embodiment, the light stabilizer obtained by compounding any two of the aforementioned different components has the effect of absorbing or reflecting ultraviolet light and interrupting the photoreaction of maleic anhydride, which can more effectively improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, meet the needs of producing high-quality maleic anhydride products, and thus effectively improve the appearance quality of downstream products.

[0026] According to a more preferred embodiment of the present invention, the light stabilizer is a mixture of 4-tert-butylphenyl salicylate and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane. Using the aforementioned embodiment, the light stabilizer obtained by compounding 4-tert-butylphenyl salicylate with 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane has the effect of absorbing or reflecting ultraviolet light and interrupting the photoreaction of maleic anhydride. This can further improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, meet the needs of producing high-quality maleic anhydride products, and further improve the appearance quality of downstream products.

[0027] The present invention does not have a particular limitation on the mass ratio of the mixture of salicylic acid-4-tert-butylphenyl ester and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane. According to a preferred embodiment of the present invention, the mass ratio of the mixture of salicylic acid-4-tert-butylphenyl ester and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane is 0.5-5:1, more preferably 1-3:1. Using the aforementioned implementation scheme, by compounding 4-tert-butylphenyl salicylate with 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane at a mass ratio of 0.5-5:1, especially the light stabilizer obtained by compounding at a mass ratio of 1-3:1, the light stabilizer has the effect of absorbing or reflecting ultraviolet rays and interrupting the photoreaction of maleic anhydride. This can further improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, meet the needs of producing high-quality maleic anhydride products, and greatly improve the appearance quality of downstream products.

[0028] According to a preferred embodiment of the present invention, the antioxidant is selected from at least one of dilauryl thiodipropanol, tris(2,4-di-tert-butylphenyl) phosphite, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,6-di-tert-butyl-4-methylphenol, and octadecyl alcohol β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. Using the aforementioned embodiment, the obtained antioxidant has the effect of inhibiting the oxidation reaction of maleic anhydride, effectively improving the high-temperature stability of maleic anhydride products, reducing the high-temperature color number of maleic anhydride products, meeting the needs of producing high-quality maleic anhydride products, and thus improving the appearance quality of downstream products.

[0029] According to a particularly preferred embodiment of the present invention, the antioxidant is selected from any two of the following: dilauryl thiodipropanol, tris(2,4-di-tert-butylphenyl) phosphite, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,6-di-tert-butyl-4-methylphenol, and octadecyl alcohol β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate. Using the aforementioned embodiment, the antioxidant obtained by compounding any two of the aforementioned different components has the effect of inhibiting the oxidation reaction of maleic anhydride, which can more effectively improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, better meet the needs of producing high-quality maleic anhydride products, and thus effectively improve the appearance quality of downstream products.

[0030] According to a more preferred embodiment of the present invention, the antioxidant is a mixture of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. Using the aforementioned embodiment, the antioxidant obtained by compounding tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] has the effect of inhibiting the oxidation reaction of maleic anhydride, which can further improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, meet the needs of producing high-quality maleic anhydride products, and further improve the appearance quality of downstream products.

[0031] The present invention does not impose any particular limitation on the mass ratio of the mixture of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. According to a preferred embodiment of the present invention, the mass ratio of the mixture of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] is 0.5-5:1, more preferably 1-3:1. Using the aforementioned implementation scheme, by compounding tris(2,4-di-tert-butylphenyl) phosphite with pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] at a mass ratio of 0.5-5:1, especially at a mass ratio of 1-3:1, the resulting antioxidant has the effect of inhibiting the oxidation reaction of maleic anhydride, which can further improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, meet the needs of producing high-quality maleic anhydride products, and greatly improve the appearance quality of downstream products.

[0032] According to a preferred embodiment of the present invention, the acyl chloride reagent is selected from at least one of acetyl chloride, isobutyryl chloride, trichloroacetyl chloride, and phosphorus oxychloride. Using the aforementioned embodiment, the obtained acyl chloride reagent preferentially undergoes oxidation of maleic anhydride or preferentially reacts with impurities in maleic anhydride, effectively improving the high-temperature stability of maleic anhydride products, reducing the high-temperature color number of maleic anhydride products, meeting the needs of producing high-quality maleic anhydride products, and thus improving the appearance quality of downstream products.

[0033] According to a particularly preferred embodiment of the present invention, the acyl chloride reagent is selected from any two of acetyl chloride, isobutyryl chloride, trichloroacetyl chloride, and phosphorus oxychloride. By employing the aforementioned embodiment, the acyl chloride reagent obtained by compounding any two of the aforementioned different components preferentially undergoes oxidation of maleic anhydride or preferentially reacts with impurities in maleic anhydride. This can more effectively improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, better meet the needs of producing high-quality maleic anhydride products, and thus effectively improve the appearance quality of downstream products.

[0034] According to a more preferred embodiment of the present invention, the acyl chloride reagent is a mixture of isobutyryl chloride and trichloroacetyl chloride. By employing the aforementioned embodiment, the acyl chloride reagent obtained by compounding isobutyryl chloride and trichloroacetyl chloride preferentially undergoes oxidation of maleic anhydride or preferentially reacts with impurities in maleic anhydride, thereby further improving the high-temperature stability of maleic anhydride products, reducing the high-temperature color number of maleic anhydride products, meeting the needs of producing high-quality maleic anhydride products, and further improving the appearance quality of downstream products.

[0035] This invention does not impose any particular limitation on the mass ratio of isobutyryl chloride to trichloroacetyl chloride. According to a preferred embodiment of the invention, the mass ratio of isobutyryl chloride to trichloroacetyl chloride is 0.5-5:1, more preferably 1-3:1. By employing the aforementioned embodiments, the acyl chloride reagent obtained by compounding isobutyryl chloride and trichloroacetyl chloride at a mass ratio of 0.5-5:1, especially at a mass ratio of 1-3:1, preferentially reacts with maleic anhydride or with impurities in maleic anhydride. This further improves the high-temperature stability of maleic anhydride products, reduces the high-temperature color number of maleic anhydride products, meets the needs of producing high-quality maleic anhydride products, and greatly improves the appearance quality of downstream products.

[0036] According to a second aspect of the present invention, the present invention provides the application of the maleic anhydride stabilizer described in the first aspect in the stabilization treatment of maleic anhydride products.

[0037] In this invention, the maleic anhydride stabilizer provided by this invention is used in the stabilization process of maleic anhydride products. It has the characteristics of long stabilization period and good stabilization effect, which can effectively improve the high temperature stability of maleic anhydride products, reduce the high temperature color number of maleic anhydride products, meet the needs of producing high-quality maleic anhydride products, and thus improve the appearance quality of downstream products.

[0038] In this invention, the quality indicators of the maleic anhydride product with added maleic anhydride stabilizer meet the requirements of national standard GB / T3676-2020 or Zhejiang Manufacturing T / ZZB 1198-2019, solving the technical problem that existing maleic anhydride color stabilizers have poor protective effects on maleic anhydride products at high temperatures, failing to meet the needs of producing high-quality maleic anhydride products. Specifically, the solid maleic anhydride product meets the following requirements: melting color (platinum-cobalt color number) ≤20 at 65℃, and melting color (platinum-cobalt color number) ≤50 after heating to 140℃ and holding for 2 hours; the liquid maleic anhydride product meets the following requirements: melting color (platinum-cobalt color number) ≤20 at 65℃, and melting color (platinum-cobalt color number) ≤40 after heating to 140℃ and holding for 2 hours.

[0039] According to a third aspect of the present invention, the present invention provides a method of using the maleic anhydride stabilizer described in the first aspect, the method comprising: mixing a light stabilizer, an antioxidant and an acyl chloride reagent at room temperature to obtain a maleic anhydride stabilizer; and then mixing the maleic anhydride stabilizer with maleic anhydride.

[0040] In this invention, the method of using maleic anhydride stabilizer is characterized by its simple operation and strong practicality. Moreover, the device has low energy consumption, low cost, and is environmentally friendly, and can be used for large-scale maleic anhydride stabilization treatment. By using this method, maleic anhydride stabilizers with long stabilization time and good stabilization effect can be added to maleic anhydride products to perform stabilization treatment. The high-temperature stability of the treated maleic anhydride products is significantly improved, and its high-temperature color number is also significantly reduced. This not only meets the requirements for producing high-quality maleic anhydride products, but also improves the appearance quality of downstream products.

[0041] According to a preferred embodiment of the present invention, the amount of maleic anhydride stabilizer added is 3-25 ppm, preferably 5-15 ppm. In this invention, ppm is a concentration expressed as parts per million (ppm) of the added component to the mass of maleic anhydride, also known as parts per million concentration. By adopting the aforementioned embodiment, the high-temperature stability of maleic anhydride products can be effectively improved, the high-temperature color number of maleic anhydride products can be reduced, meeting the needs of producing high-quality maleic anhydride products, thereby improving the appearance quality of downstream products; especially when the amount of maleic anhydride stabilizer added is 5-15 ppm, the high-temperature stability of maleic anhydride products can be further improved, the high-temperature color number of maleic anhydride products can be reduced, better meeting the needs of producing high-quality maleic anhydride products, thereby effectively improving the appearance quality of downstream products.

[0042] This invention does not impose a specific limitation on the mixing time, as long as the refined maleic anhydride and the maleic anhydride stabilizer are mixed evenly. According to a preferred embodiment of the invention, the mixing time is greater than or equal to 0.5 hours, preferably 1-3 hours. Using the aforementioned embodiment, the maleic anhydride and the maleic anhydride stabilizer can be mixed more evenly, effectively improving the high-temperature stability of the maleic anhydride product, reducing the high-temperature color number of the maleic anhydride product, meeting the needs of producing high-quality maleic anhydride products, and thus improving the appearance quality of downstream products. In particular, when the mixing time is 1-3 hours, the degree of uniform mixing of maleic anhydride and the maleic anhydride stabilizer can be further improved, further enhancing the high-temperature stability of the maleic anhydride product, reducing the high-temperature color number of the maleic anhydride product, better meeting the needs of producing high-quality maleic anhydride products, and thus effectively improving the appearance quality of downstream products.

[0043] This invention does not impose any particular limitation on the mixing method of the maleic anhydride stabilizer and maleic anhydride, as long as the maleic anhydride stabilizer and maleic anhydride can be fully contacted and mixed evenly. According to a preferred embodiment of this invention, an admixture is used... Figure 1The device in the process mixes maleic anhydride stabilizer and maleic anhydride. The specific process includes: first, turning on the maleic anhydride feed pump (6) and using the maleic anhydride feed pump (6) to transport the maleic anhydride in the refined maleic anhydride storage tank (1) to the maleic anhydride stabilization tank (2), and at the same time, transporting the maleic anhydride stabilizer to the maleic anhydride stabilization tank (2) through the dosing filter tank (3). Then, turning on the reflux pump (5) of the maleic anhydride stabilization tank (2) and maintaining reflux, and using the reflux pump (5) to reflux the maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization tank (2) back to the maleic anhydride stabilization tank (2) through the reflux pipe (4).

[0044] The present invention does not impose any particular limitation on the order in which the maleic anhydride and the maleic anhydride stabilizer are transported to the maleic anhydride stabilization tank (2). For example, it may be: first transporting the maleic anhydride to the maleic anhydride stabilization tank (2), and then transporting the maleic anhydride stabilizer to the maleic anhydride stabilization tank (2); or first transporting the maleic anhydride stabilizer to the maleic anhydride stabilization tank (2), and then transporting the maleic anhydride to the maleic anhydride stabilization tank (2); or simultaneously transporting the maleic anhydride and the maleic anhydride stabilizer to the maleic anhydride stabilization tank (2).

[0045] According to a preferred embodiment of the present invention, the reflux flow rate is 0.5-3 times, preferably 1-2 times, the mass of maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization tank (2). By employing the aforementioned embodiment, the maleic anhydride and maleic anhydride stabilizer can be mixed more uniformly, effectively improving the high-temperature stability of the maleic anhydride product, reducing the high-temperature color number of the maleic anhydride product, meeting the needs of producing high-quality maleic anhydride products, and thus improving the appearance quality of downstream products. In particular, when the reflux flow rate is 1-2 times the mass of maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization tank (2), the degree of uniform mixing of maleic anhydride and maleic anhydride stabilizer can be further improved, further enhancing the high-temperature stability of the maleic anhydride product, reducing the high-temperature color number of the maleic anhydride product, better meeting the needs of producing high-quality maleic anhydride products, and thus effectively improving the appearance quality of downstream products.

[0046] In this invention, the purpose of the reflux conveying is to ensure a more thorough mixing of maleic anhydride and maleic anhydride stabilizer. According to a preferred embodiment of the invention, the reflux conveying time is greater than or equal to 0.5 hours, preferably 1-3 hours. By employing the aforementioned embodiment, the maleic anhydride and maleic anhydride stabilizer can be mixed more uniformly, effectively improving the high-temperature stability of the maleic anhydride product, reducing the high-temperature color number of the maleic anhydride product, meeting the needs of producing high-quality maleic anhydride products, and thus improving the appearance quality of downstream products. In particular, when the reflux conveying time is 1-3 hours, the degree of uniform mixing of maleic anhydride and maleic anhydride stabilizer can be further improved, further enhancing the high-temperature stability of the maleic anhydride product, reducing the high-temperature color number of the maleic anhydride product, better meeting the needs of producing high-quality maleic anhydride products, and thus effectively improving the appearance quality of downstream products.

[0047] The present invention will be described in detail below through embodiments.

[0048] In the following examples, the color of the maleic anhydride sample was determined by visually comparing it with a platinum-cobalt color standard or by using a VISTA benchtop colorimeter after the maleic anhydride sample was kept at a preset temperature for a preset time. The maleic anhydride sample was refined maleic anhydride produced by Ningbo Zhetie Jiangning Chemical Co., Ltd.; 4-tert-butylphenyl salicylate was a commercially available product from Wuhan Qiongge Biotechnology Co., Ltd. (purity ≥98%); 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane, tris(2,4-di-tert-butylphenyl) phosphite, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and octadecyl alcohol β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate were from Shanghai Lier New Materials Co., Ltd. Commercially available products with purity ≥ 98%; 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole is a commercially available product from Shanghai Hanhong Technology Co., Ltd. (purity ≥ 98%); zinc oxide and iron oxide are commercially available products from Wuxi Yasheng Chemical Co., Ltd. (analytical grade); dithiodipropanol dilaurate is a commercially available product from Henan Wanheng Biotechnology Co., Ltd. (purity ≥ 98%); 2,6-di-tert-butyl-4-methylphenol is a commercially available product from Nantong Runfeng Petrochemical Co., Ltd. (purity ≥ 99%); acetyl chloride is a commercially available product from Shanghai Guchen Biotechnology Co., Ltd. (purity ≥ 99%); isobutyryl chloride is a commercially available product from Hubei Dongcao Chemical Technology Co., Ltd. (purity ≥ 99%); trichloroacetyl chloride is a commercially available product from Nanjing Weiao Chemical Co., Ltd. (purity ≥ 99%); phosphorus oxychloride is a commercially available product from Shanghai Siyan Biotechnology Co., Ltd. (purity ≥ 99%).

[0049] The color number testing method and testing standard refer to the national standard GB / T 3676-2020 or Zhejiang manufacturing standard T / ZZB1198-2019.

[0050] To demonstrate the effectiveness of the maleic anhydride stabilizer of the present invention, high-temperature stability (140℃ for 2 hours and 200℃ for 10 minutes), long-term storage stability (65℃, 0-90 days) and pilot-scale tests were conducted on the maleic anhydride product.

[0051] The high-temperature stability test method is as follows: Take 500 mL of the company's refined maleic anhydride (without additives), add an appropriate amount of the maleic anhydride stabilizer of this invention, take 50 mL of the added maleic anhydride sample, seal it, transfer it to a digester, and set the temperature to 140℃ for 2 hours or 200℃ for 10 minutes. The detection method is as follows: After adding the maleic anhydride stabilizer of this invention, visually compare it with the platinum-cobalt color standard or use a VISTA benchtop colorimeter to determine the color of the maleic anhydride sample; after holding it at the preset temperature for a preset time, visually compare it with the platinum-cobalt color standard again or use a VISTA benchtop colorimeter to determine the color of the maleic anhydride sample.

[0052] The long-term storage stability test method is as follows: Take 500 mL of the company's refined maleic anhydride (without additives), add an appropriate amount of the maleic anhydride stabilizer of this invention, seal the maleic anhydride sample, transfer it to an oven, and heat it at 65℃ for 90 days. On days 0 (the current day), 7, 14, 21, 28, 60, and 90, take 50 mL of the sample, transfer it to a digester, and heat it at 140℃ for 2 hours. The detection method is as follows: After adding the maleic anhydride stabilizer of this invention, visually compare it with the platinum-cobalt color standard or use a VISTA benchtop colorimeter to determine the color of the maleic anhydride sample; after heat treatment at a preset temperature for a preset time, again visually compare it with the platinum-cobalt color standard or use a VISTA benchtop colorimeter to determine the color of the maleic anhydride sample.

[0053] The pilot-scale testing method is as follows:

[0054] (1) A dosing filter tank 3 was added to the return pipe 4 of the maleic anhydride stabilization tank 2;

[0055] (2) The maleic anhydride stabilization tank 2 is emptied and the liquid level is reduced to the minimum.

[0056] (3) First, replace the maleic anhydride stabilization tank 2 with two consecutive batches of blank refined maleic anhydride; add the third batch of blank refined maleic anhydride to the maleic anhydride stabilization tank 2 to 140t, and take the first sample for analysis. The sampling points are the reflux pipe 4, the refined maleic anhydride storage tank 1 and the maleic anhydride stabilization tank 2.

[0057] (4) Add 3-25 ppm of the maleic anhydride stabilizer obtained in Example 2 to the maleic anhydride stabilization tank 2, stir for 2 hours by the bottom reflux pump 5, and take a second sample for analysis. The sampling point is the maleic anhydride stabilization tank 2.

[0058] (5) The maleic anhydride in the subsequent maleic anhydride stabilization tank 2 is kept under reflux and sampled and analyzed once a day.

[0059] Example 1

[0060] The maleic anhydride stabilizer comprises the following raw materials by weight percentage: 20% light stabilizer, 20% antioxidant, and 60% acyl chloride reagent;

[0061] The light stabilizer is a mixture of 4-tert-butylphenyl salicylate and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane in a mass ratio of 3:1; the antioxidant is a mixture of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] in a mass ratio of 3:1; and the acyl chloride reagent is a mixture of isobutyryl chloride and trichloroacetyl chloride in a mass ratio of 3:1.

[0062] The method of using maleic anhydride stabilizer in this embodiment is as follows: Figure 1 The flowchart shown includes the following steps:

[0063] (1) Preparation of maleic anhydride stabilizer: At room temperature, 1.2 mg of light stabilizer, 1.2 mg of antioxidant and 3.6 mg of acyl chloride reagent were mixed evenly to obtain maleic anhydride stabilizer;

[0064] (2) Addition of maleic anhydride stabilizer: First, turn on the feed pump 6 to transport the maleic anhydride in the refined maleic anhydride storage tank 1 to the maleic anhydride stabilization treatment tank 2. Then, according to the dosage of 5 ppm of maleic anhydride mass, transport the maleic anhydride stabilizer obtained in step (1) through the dosing filter tank 3 to the maleic anhydride stabilization treatment tank 2. Turn on the reflux pump 5 and keep it refluxed. Use the reflux pump 5 to reflux the maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization treatment tank 2 back to the maleic anhydride stabilization treatment tank 2 through the reflux pipe 4 for 1 hour. The reflux flow rate is 1 times the mass of maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization treatment tank 2.

[0065] Example 2

[0066] The maleic anhydride stabilizer comprises the following raw materials by weight percentage: 30% light stabilizer, 30% antioxidant, and 40% acyl chloride reagent;

[0067] The light stabilizer is a mixture of 4-tert-butylphenyl salicylate and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane in a mass ratio of 2:1; the antioxidant is a mixture of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] in a mass ratio of 2:1; and the acyl chloride reagent is a mixture of isobutyryl chloride and trichloroacetyl chloride in a mass ratio of 2:1.

[0068] The method of using maleic anhydride stabilizer in this embodiment is as follows: Figure 1 The flowchart shown includes the following steps:

[0069] (1) Preparation of maleic anhydride stabilizer: At room temperature, 1.8 mg of light stabilizer, 1.8 mg of antioxidant and 2.4 mg of acyl chloride reagent are mixed evenly to obtain maleic anhydride stabilizer;

[0070] (2) Addition of maleic anhydride stabilizer: First, turn on the feed pump 6 to transport the maleic anhydride in the refined maleic anhydride storage tank 1 to the maleic anhydride stabilization tank 2. Then, according to the dosage of 6.5 ppm of maleic anhydride, the maleic anhydride stabilizer obtained in step (1) is transported to the maleic anhydride stabilization tank 2 through the dosing filter tank 3. Turn on the reflux pump 5 and keep it refluxed. Use the reflux pump 5 to reflux the maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization tank 2 back to the maleic anhydride stabilization tank 2 through the reflux pipe 4 for 2 hours. The reflux flow rate is twice the mass of maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization tank 2.

[0071] Example 3

[0072] The maleic anhydride stabilizer comprises the following raw materials by weight percentage: 40% light stabilizer, 30% antioxidant, and 30% acyl chloride reagent;

[0073] The light stabilizer is a mixture of 4-tert-butylphenyl salicylate and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane in a mass ratio of 1:1; the antioxidant is a mixture of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] in a mass ratio of 1:1; and the acyl chloride reagent is a mixture of isobutyryl chloride and trichloroacetyl chloride in a mass ratio of 1:1.

[0074] The method of using maleic anhydride stabilizer in this embodiment is as follows: Figure 1 The flowchart shown includes the following steps:

[0075] (1) Preparation of maleic anhydride stabilizer: At room temperature, 2.4 mg of light stabilizer, 1.8 mg of antioxidant and 1.8 mg of acyl chloride reagent were mixed evenly to obtain maleic anhydride stabilizer;

[0076] (2) Addition of maleic anhydride stabilizer: First, turn on the feed pump 6 to transport the maleic anhydride in the refined maleic anhydride storage tank 1 to the maleic anhydride stabilization treatment tank 2. Then, according to the dosage of 15 ppm of maleic anhydride mass, transport the maleic anhydride stabilizer obtained in step (1) through the dosing filter tank 3 to the maleic anhydride stabilization treatment tank 2. Turn on the reflux pump 5 and keep it refluxed. Use the reflux pump 5 to reflux the maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization treatment tank 2 back to the maleic anhydride stabilization treatment tank 2 through the reflux pipe 4 for 3 hours. The reflux flow rate is 1.5 times the mass of maleic anhydride and maleic anhydride stabilizer in the maleic anhydride stabilization treatment tank 2.

[0077] Example 4

[0078] The method of Example 2 is different except that in step (2) of the method of using maleic anhydride stabilizer, the amount of maleic anhydride stabilizer added is 3 ppm of maleic anhydride mass.

[0079] Example 5

[0080] The method of Example 2 is different except that in step (2) of the method of using maleic anhydride stabilizer, the amount of maleic anhydride stabilizer added is 4 ppm of maleic anhydride mass.

[0081] Example 6

[0082] The method of Example 2 is different except that in step (2) of the method of using maleic anhydride stabilizer, the amount of maleic anhydride stabilizer added is 17 ppm of maleic anhydride mass.

[0083] Example 7

[0084] The method of Example 2 is different except that in step (2) of the method of using maleic anhydride stabilizer, the amount of maleic anhydride stabilizer added is 19 ppm of maleic anhydride mass.

[0085] Example 8

[0086] The method is the same as in Example 2, except that in step (2) of the method of using maleic anhydride stabilizer, the amount of maleic anhydride stabilizer added is 22 ppm of maleic anhydride mass.

[0087] Example 9

[0088] The method of Example 2 is different except that in step (2) of the method of using maleic anhydride stabilizer, the amount of maleic anhydride stabilizer added is 25 ppm of maleic anhydride mass.

[0089] Comparative Example 1

[0090] The method of Example 2 is the same, except that the maleic anhydride stabilizer is a commercially available stabilizer, including the following raw materials in the following mass percentages: 20% phenyl phthalate, 20% benzophenone, and 60% hexamethylphosphoric acid triamine.

[0091] Specifically, it includes: 1.2 mg of phenyl oxalate, 1.2 mg of 2,4-dihydroxybenzophenone, and 3.6 mg of hexamethylphosphoric acid triamine.

[0092] Example 10

[0093] The method of Example 2 is different except that the maleic anhydride stabilizer comprises the following raw materials in weight percentages: 15% light stabilizer, 15% antioxidant, and 70% acyl chloride reagent.

[0094] Example 11

[0095] The method is the same as in Example 2, except that the maleic anhydride stabilizer comprises the following raw materials in weight percentages: 40% light stabilizer, 40% antioxidant, and 20% acyl chloride reagent.

[0096] Example 12

[0097] The method is the same as in Example 2, except that the light stabilizer is a mixture of 4-tert-butylphenyl salicylate and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane in a mass ratio of 0.5:1; the antioxidant is a mixture of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] in a mass ratio of 4:1; and the acyl chloride reagent is a mixture of isobutyryl chloride and trichloroacetyl chloride in a mass ratio of 5:1.

[0098] Example 13

[0099] The method is the same as in Example 2, except that the light stabilizer is 4-tert-butylphenyl salicylate; the antioxidant is tris(2,4-di-tert-butylphenyl) phosphite; and the acyl chloride reagent is isobutyryl chloride.

[0100] Example 14

[0101] The method is the same as in Example 2, except that the light stabilizer is 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane; the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; and the acyl chloride reagent is trichloroacetyl chloride.

[0102] Example 15

[0103] The method is the same as in Example 2, except that in step (2) of the method of using maleic anhydride stabilizer, the amount of maleic anhydride stabilizer added is 0.1 ppm of maleic anhydride mass.

[0104] Example 16

[0105] The method is the same as in Example 2, except that in step (2) of the method of using maleic anhydride stabilizer, the amount of maleic anhydride stabilizer added is 40 ppm of maleic anhydride mass.

[0106] Example 17

[0107] The method of Example 2 is different except that in step (2) of the method of using maleic anhydride stabilizer, the reflux flow rate is 0.5 times the mass of maleic anhydride and maleic anhydride stabilizer in maleic anhydride stabilization tank 2.

[0108] Example 18

[0109] The method of Example 2 is different except that in step (2) of the method of using maleic anhydride stabilizer, the reflux flow rate is 3 times the mass of maleic anhydride and maleic anhydride stabilizer in maleic anhydride stabilization treatment tank 2.

[0110] Example 19

[0111] The method is the same as in Example 2, except that in step (2) of the method for using maleic anhydride stabilizer, the reflux delivery time is 0.5 h.

[0112] Example 20

[0113] The method is the same as in Example 2, except that in step (2) of the method for using maleic anhydride stabilizer, the reflux delivery time is 5 hours.

[0114] Comparative Example 2

[0115] The method of Example 2 is different except that the maleic anhydride stabilizer comprises the following raw materials in weight percentages: 2% light stabilizer, 95% antioxidant, and 3% acyl chloride reagent.

[0116] Comparative Example 3

[0117] The method of Example 2 is different except that the maleic anhydride stabilizer comprises the following raw materials in weight percentages: 90% light stabilizer, 5% antioxidant, and 5% acyl chloride reagent.

[0118] Comparative Example 4

[0119] The method of Example 2 is different except that the maleic anhydride stabilizer comprises the following raw materials by mass percentage: 0% light stabilizer, 45% antioxidant, and 55% acyl chloride reagent.

[0120] Comparative Example 5

[0121] The method of Example 2 is different except that the maleic anhydride stabilizer comprises the following raw materials in weight percentages: 45% light stabilizer, 0% antioxidant, and 55% acyl chloride reagent.

[0122] Comparative Example 6

[0123] The method of Example 2 is different except that the maleic anhydride stabilizer comprises the following raw materials by mass percentage: 50% light stabilizer, 50% antioxidant, and 0% acyl chloride reagent.

[0124] Experimental Example 1

[0125] Taking maleic anhydride as an example, the maleic anhydride stabilizers of Examples 1-20 and Comparative Examples 1-6 of the present invention were used to conduct high-temperature stability tests (including 140°C, 2h and 200°C, 10min). The color number of the maleic anhydride after heating was determined according to GB / T 3676-2020, and the high-temperature stability of the maleic anhydride was determined.

[0126] Blank control group: Take 500 mL of purified maleic anhydride, with a maleic anhydride stabilizer addition of 0 ppm;

[0127] Examples 1-20 and Comparative Examples 1-6 were added according to the specific formulation and amount of stabilizer described in the examples. All maleic anhydride used was from the same production batch of our company. The experimental results are shown in Table 1.

[0128] Table 1

[0129]

[0130]

[0131]

[0132] Table 1 shows that after adding 3-25 ppm of maleic anhydride stabilizer and heating to 140℃ for 2 hours, the average final color number of maleic anhydride is between 15 and 30, while the color number of maleic anhydride without the stabilizer is greater than 50. After heating to 200℃ for 10 minutes, the average final color number of maleic anhydride is between 40 and 50, while the color number of maleic anhydride without the stabilizer is greater than 100. Therefore, the maleic anhydride stabilizer provided by this invention has the characteristics of long stabilization time and good stabilization effect, which can effectively improve the high-temperature stability of maleic anhydride products, reduce the high-temperature color number of maleic anhydride products, and ensure that the color number of maleic anhydride meets the requirements of GB / T 3676-2020 or standard ASTM D3366-18, thus meeting the needs of producing high-quality maleic anhydride products.

[0133] Experiment Example 2

[0134] Taking maleic anhydride as an example, long-term storage tests (65°C, 0-90 days) were conducted using the maleic anhydride stabilizers of Examples 1-20 and Comparative Examples 1-6 of the present invention. The color number of maleic anhydride after long-term storage was determined and the stability of maleic anhydride during long-term storage was determined in accordance with GB / T 3676-2020.

[0135] Blank control group: Take 500 mL of purified maleic anhydride, with a maleic anhydride stabilizer addition of 0 ppm;

[0136] Examples 1-20 and Comparative Examples 1-6 were added according to the specific formulation and amount of stabilizer described in the examples. All maleic anhydride used was from the same production batch of our company. The experimental results are shown in Table 2.

[0137] Table 2

[0138]

[0139]

[0140]

[0141]

[0142] As shown in Table 2, in the long-term storage test at 65℃, the maleic anhydride products with added 3-25ppm maleic anhydride stabilizer all had a maleic anhydride color number within 40; after 60 days of storage, the maleic anhydride products were kept at 140℃ for 2 hours, and the maleic anhydride products were kept at 140℃ for 2 hours, and the maleic anhydride products were kept at 140℃ for 2 hours, and the maleic anhydride color number was within 35. The maleic anhydride color numbers all meet the requirements of GB / T 3676-2020 or standard ASTM D3366-18, which can meet the needs of producing high-quality maleic anhydride products.

[0143] Experimental Example 3

[0144] Taking maleic anhydride as an example, a pilot-scale test (140t of maleic anhydride) was conducted using the maleic anhydride stabilizers of Examples 1-3 and 6 of the present invention. The color number of the maleic anhydride after heating was determined according to GB / T 3676-2020, and the high-temperature and long-term storage stability of the maleic anhydride was determined.

[0145] Blank control group: 140t of refined maleic anhydride was taken, and the amount of maleic anhydride stabilizer added was 0ppm;

[0146] Examples 1-3 and Example 6 were performed according to the specific formulation and amount of stabilizer added in the examples. The maleic anhydride used was from different production batches of our company. The results were retested after two months and are shown in Table 3.

[0147] Table 3

[0148]

[0149]

[0150]

[0151] Table 4

[0152]

[0153]

[0154] As shown in Tables 3 and 4, after adding an appropriate amount of maleic anhydride stabilizer to 140t of maleic anhydride, the color number of the maleic anhydride product stabilizes below 30 after being kept at 140℃ for 2 hours, and below 85 after being kept at 200℃ for 10 minutes, meeting the requirements of GB / T3676-2020 or standard ASTM D3366-18. After 60 days, the purity of the maleic anhydride product decreased slightly, and the high-temperature color increased slightly. The color number of the maleic anhydride product stabilized below 55 after being kept at 140℃ for 2 hours, and below 90 after being kept at 200℃ for 10 minutes, but still met the requirements of GB / T 3676-2020 or standard ASTM D3366-18. This meets the needs of producing high-quality maleic anhydride products and can be used for large-scale maleic anhydride stabilization treatment, facilitating industrial production applications.

[0155] 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 maleic anhydride stabilizer characterized by comprising: By mass percentage, the maleic anhydride stabilizer comprises the following components: 15-50% light stabilizer, 15-50% antioxidant, and 20-70% acyl chloride reagent; The light stabilizer is a mixture of 4-tert-butylphenyl salicylate and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane; The antioxidant is a mixture of tris(2,4-di-tert-butylphenyl) phosphite and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; The acyl chloride reagent is a mixture of isobutyryl chloride and trichloroacetyl chloride.

2. The maleic anhydride stabilizer according to claim 1, wherein, The maleic anhydride stabilizer is composed of the following components: 20-40% light stabilizer, 20-40% antioxidant, and 30-60% acyl chloride reagent.

3. The maleic anhydride stabilizer according to claim 1 or 2, wherein, The mass ratio of the mixture of salicylic acid-4-tert-butylphenyl ester and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane is 1-3:

1.

4. The maleic anhydride stabilizer according to claim 1 or 2, wherein, The mass ratio of the tris(2,4-di-tert-butylphenyl) phosphite to pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] is 1-3:

1.

5. The maleic anhydride stabilizer according to claim 1 or 2, wherein, The mass ratio of isobutyryl chloride to trichloroacetyl chloride is 1-3:

1.

6. The use of the maleic anhydride stabilizer according to any one of claims 1-5 in the stabilization treatment of maleic anhydride products.

7. The use of the maleic anhydride stabilizer according to any one of claims 1 to 5, characterized in that The method of use includes: mixing a light stabilizer, an antioxidant, and an acyl chloride reagent at room temperature to obtain a maleic anhydride stabilizer; and then mixing the maleic anhydride stabilizer with maleic anhydride.

8. The method of use according to claim 7, wherein, The amount of maleic anhydride stabilizer added is 3-25 ppm; and / or The mixing time is greater than or equal to 0.5 hours.

9. The method of use according to claim 8, wherein, The amount of maleic anhydride stabilizer added is 5-15 ppm; and / or The mixing time is 1-3 hours.

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