A tetraamide benzene derivative and preparation method thereof

Abstract

The present invention provides a tetraamide benzene derivative, the structure of which is shown in formula (I), wherein R 1 , R 2 , R 3 and R 4 Independently selected from alkyl, aromatic, cycloalkyl or alkylated substituted aromatic, the preparation method includes using m-dichlorobenzene as raw material, obtaining intermediate 1,5-dichloro-2,4-dinitrobenzene through nitration reaction, obtaining intermediate 4,6-dinitro-1,3-phenylenediamine through amination reaction, obtaining intermediate 1,2,4,5-benzene tetraamine tetrahydrochloride through reduction reaction, and finally obtaining the tetraamide benzene derivative through acylation reaction. The tetraamide benzene derivative of the present invention can be applied to polypropylene nucleating agent, effectively improving the mechanical properties such as crystallinity, molding speed and rigidity of polypropylene materials. The tetraamide benzene derivative of the present invention has no odor, good compatibility with materials, is easy to disperse, does not precipitate, can improve the performance of polypropylene materials, and broaden the application field of polypropylene materials.

Description

Technical Field

[0001] The invention relates to the technical field of polymer nucleating agent preparation, in particular to a tetraamide benzene derivative and a preparation method thereof. Background Art

[0002] As a general thermoplastic resin, polypropylene has the advantages of non-toxicity, good heat resistance, good corrosion resistance, excellent electrical insulation, high heat deformation temperature, easy processing, and low cost, and is widely used in life. However, there are still many shortcomings and defects, such as brittleness, easy breakage, low heat resistance temperature, low bending strength, poor transparency, poor conductivity, etc., which lead to a narrow range of practical applications. By adding high-efficiency nucleating agents, the above shortcomings can be effectively improved through synergistic effects. Polypropylene modified with nucleating agents has a higher degree of crystallinity, and its crystallization rate and crystallization temperature are also improved, which is convenient for rapid processing and molding; and nucleating agents can make the spherulites of polypropylene smaller and more uniform, and improve the mechanical properties and optical properties of polypropylene. Further broaden its application field, it has good rigidity, transparency, surface gloss and heat deformation resistance at relatively low concentrations.

[0003] Nucleating agents are mainly divided into inorganic nucleating agents and organic nucleating agents. Organic nucleating agents have good compatibility with polypropylene matrix and high nucleating efficiency, and have been widely used. Among them, aromatic amides are a type of organic nucleating agent with high nucleating efficiency, not easy to decompose at high temperature, and excellent comprehensive performance. It is a product prepared by the reaction of amine compounds and acylating agents. This type of nucleating agent has good nucleating effect and low cost, and can give polypropylene good transparency, rigidity and heat deformation resistance. With the expansion of polypropylene applications, the market has put forward higher requirements on various properties of polypropylene materials, including mechanical properties. Although the existing nucleating agents provide a certain improvement effect, it is not completely satisfactory. Therefore, how to further develop new nucleating agents to improve the performance of polypropylene materials has become an urgent problem to be solved. Summary of the invention

[0004] The present invention aims to provide a tetraamide benzene derivative which can be used as a polymer nucleating agent, and a method for preparing the tetraamide benzene derivative, so as to solve the above-mentioned defects existing in the background technology.

[0005] The first aspect of the present invention is to provide a tetraamide benzene derivative, the structure of which is shown in formula (I):

[0006]

[0007] Among them, R 1 , R 2 , R 3 and R 4 are independently selected from alkyl, aryl, cycloalkyl or alkylated substituted aryl. 1 , R2 , R 3 and R 4 are independently selected from isopropyl, n-butyl, isobutyl, and 2-ethylhexyl. More preferably, R 1 , R 2 , R 3 and R 4 are the same substituents and are selected from isopropyl, n-butyl, isobutyl, and 2-ethylhexyl. As a more preferred technical solution, R 1 , R 2 , R 3 and R 4 It is isobutyl.

[0008] The second aspect of the present invention is to provide a method for preparing the above-mentioned tetraamide benzene derivative, comprising the following steps:

[0009] S1, using m-dichlorobenzene as a raw material, obtaining the intermediate 1,5-dichloro-2,4-dinitrobenzene through nitration reaction;

[0010] S2, subjecting the intermediate 1,5-dichloro-2,4-dinitrobenzene obtained in step S1 to an amination reaction to obtain the intermediate 4,6-dinitro-1,3-phenylenediamine;

[0011] S3, subjecting the intermediate 4,6-dinitro-1,3-phenylenediamine obtained in step S2 to a reduction reaction to obtain the intermediate 1,2,4,5-benzenetetramine tetrahydrochloride;

[0012] S4, subjecting the intermediate 1,2,4,5-benzenetetraamine tetrahydrochloride obtained in step S3 to an acylation reaction to obtain the tetraamidebenzene derivative.

[0013] As a preferred technical solution, the preparation method of the tetraamide benzene derivative specifically comprises the following steps:

[0014] S1, adding m-dichlorobenzene to the nitrating agent, heating and stirring to react, after the reaction is completed, separating and purifying to obtain the intermediate 1,5-dichloro-2,4-dinitrobenzene;

[0015] S2, dispersing the intermediate 1,5-dichloro-2,4-dinitrobenzene obtained in step S1 in an appropriate amount of ethylene glycol, heating and stirring, adding an aminating agent, and separating and drying the solid after the reaction is completed to obtain the intermediate 4,6-dinitro-1,3-phenylenediamine;

[0016] S3, dispersing the intermediate 4,6-dinitro-1,3-phenylenediamine obtained in step S2 in a mixed solution of concentrated HCl and ethanol, heating and stirring, dissolving a reducing agent in an appropriate amount of ethanol, adding the mixture to the reaction solution, stirring and reacting, and separating a white powder product after the reaction is completed to obtain an intermediate 1,2,4,5-benzenetetramine tetrahydrochloride;

[0017] S4, dissolving the intermediate 1,2,4,5-benzenetetraamine tetrahydrochloride obtained in step S3 in acetonitrile, stirring, adding acyl chloride, slowly dropping a weak base, stirring to react, and separating to obtain the tetraamide benzene derivative after the reaction is completed.

[0018] Preferably, the nitrating agent in step S1 is a mixture of concentrated sulfuric acid / potassium nitrate or a mixture of concentrated sulfuric acid / concentrated nitric acid, the preferred ratio of concentrated sulfuric acid to potassium nitrate is 20:1 (m / m), the preferred ratio of concentrated sulfuric acid to concentrated nitric acid is 1:1 (m / m), and the preferred amount of the nitrating agent added is about 50 times the equivalent of m-dichlorobenzene;

[0019] Preferably, the amination reagent in step S2 is ammonia gas, and the amount used is based on the sufficient amination of the intermediate 1,5-dichloro-2,4-dinitrobenzene, and should be excessive to allow for sufficient reaction;

[0020] Preferably, the reducing agent in step S3 is tin dichloride or metallic tin, and its preferred addition amount is 9 times the equivalent of the intermediate 4,6-dinitro-1,3-phenylenediamine;

[0021] Preferably, the weak base in step S4 is triethylamine, pyridine and its homologues.

[0022] The acyl chloride in step S4 is selected from one or more of alkyl acyl chloride, aromatic acyl chloride, cycloalkyl acyl chloride or alkylated substituted aromatic acyl chloride, and the preferred amount of acyl chloride added is 8 times the equivalent of the intermediate 1,2,4,5-benzenetetramine tetrahydrochloride.

[0023] Preferably, the acyl chloride is selected from one or more of isobutyryl chloride, n-valeryl chloride, isovaleryl chloride or 2-ethylhexanoyl chloride.

[0024] The applicant synthesized a series of tetraamide benzene derivatives and found through experimental verification that the tetraamide benzene derivatives can be used as polymer nucleating agents, especially as polypropylene nucleating agents, and can effectively improve the mechanical properties of polypropylene materials such as crystallinity, molding speed and rigidity.

[0025] The polypropylene may be a polypropylene homopolymer or a random copolymer, alternating copolymer, segmented copolymer or block copolymer of polypropylene containing one or more comonomers selected from the group consisting of ethylene, C 4 -C 20 α-olefins, vinyl cyclohexane, vinyl cyclohexene, C 4 -C 20 Alkadienes, C 5 -C 12 Cyclodiene and norbornene derivatives; wherein for polypropylene random copolymers, alternating copolymers, segmented copolymers or block copolymers, the total amount of propylene and comonomers is 100%.

[0026] The amount of tetraamide benzene derivative added as a nucleating agent in polypropylene can be determined by ordinary professionals in the field through routine experimental tests. Preferably, the amount is 0.02-0.08 parts by weight based on 100 parts by weight of polypropylene.

[0027] In the actual production of polypropylene, in addition to adding nucleating agents, functional additives commonly used in the art may also be added, including lubricants, stabilizers, antioxidants, ultraviolet absorbers, heat stabilizers, light stabilizers, neutralizers, acid binders, antistatic agents, anti-blocking agents, heavy metal deactivators, flame retardants, nucleating agents, transparent agents, foaming agents, processing aids, peroxides, silane compounds, fluorine compounds, hydrotalcite, elastomers, pigments, pigments, fillers, reinforcing materials, etc.

[0028] In a preferred embodiment, the polypropylene further comprises the following additives: antioxidant 1010, antioxidant 168 and calcium stearate. Based on 100 parts by weight of polypropylene, the amounts of the above additives are as follows: 0.04-0.06 parts by weight of antioxidant 1010, 0.05-0.2 parts by weight of antioxidant 168, and 0.03-0.07 parts by weight of calcium stearate.

[0029] The tetraamide benzene derivative of the invention has no peculiar smell, good compatibility with materials, is easy to disperse, does not precipitate, can improve the performance of polypropylene materials, and broaden the application field of polypropylene materials. DETAILED DESCRIPTION

[0030] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only used as examples, but are not used to limit the scope of the present invention. Those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalent solutions, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0031] The instruments or reagents in the embodiments of the present invention without indicating the manufacturer are all conventional commercial instruments or reagents.

[0032] Example 1

[0033] Preparation of 1,3,4,6-tetraisopropylamide benzene:

[0034] Step 1: Add 25 g of m-dichlorobenzene to a solution containing 80 mL of concentrated sulfuric acid and 7.3 g of potassium nitrate, and heat and stir to react. After the reaction is completed, extract and spin dry, and the crude product is separated and purified by column chromatography to obtain the intermediate product 1,5-dichloro-2,4-dinitrobenzene.

[0035] Step 2: Disperse 1 g of the intermediate 1,5-dichloro-2,4-dinitrobenzene obtained in step 1 in 7 mL of ethylene glycol, heat and stir, continue to bubble in ammonia gas, filter and dry the solid to obtain the intermediate 4,6-dinitro-1,3-phenylenediamine.

[0036] Step 3: Disperse 0.5 g of the intermediate 4,6-dinitro-1,3-phenylenediamine obtained in step 2 in a mixture of 26 mL of concentrated HCl and 13 mL of ethanol, heat and stir, and add 4.3 g of SnCl 2 Dissolve in an appropriate amount of ethanol, add to the reaction solution, and stir to react. After the reaction is completed, filter and collect the white powder product to obtain the intermediate 1,2,4,5-benzenetetramine tetrahydrochloride.

[0037] Step 4: Dissolve 0.24 g of the intermediate 1,2,4,5-benzenetetraamine tetrahydrochloride in 30 mL of acetonitrile, stir, add 0.78 g of isobutyryl chloride, slowly drop 2 mL of triethylamine, stir to react, collect the white solid powder by suction, wash thoroughly and dry to obtain the nucleating agent 1,3,4,6-tetraisopropylamidebenzene.

[0038] Final product structure data: 1 H NMR (400 MHz, DMSO-d 6 ): δ9.30(s,4H),7.60(s,2H), 2.62-2.55(m,4H),1.23-1.09(m,24H).HRMS m / z calcd for C 22 H 34 N 4 O 4 [M+H] + : 419.26; Found:419.3. Melting point range: 215-240℃.

[0039] Example 2

[0040] Preparation of 1,3,4,6-tetra-n-butylamide benzene:

[0041] Step 1: Add 25 g of m-dichlorobenzene to a solution containing 80 mL of concentrated sulfuric acid and 7.3 g of potassium nitrate, and heat and stir to react. After the reaction is completed, extract and spin dry, and the crude product is separated and purified by column chromatography to obtain the intermediate product 1,5-dichloro-2,4-dinitrobenzene.

[0042] Step 2: Disperse 1 g of the intermediate 1,5-dichloro-2,4-dinitrobenzene obtained in step 1 in 7 mL of ethylene glycol, heat and stir, continue to bubble in ammonia gas, filter and dry the solid to obtain the intermediate 4,6-dinitro-1,3-phenylenediamine.

[0043] Step 3: Disperse 0.5 g of the intermediate 4,6-dinitro-1,3-phenylenediamine obtained in step 2 in a mixture of 26 mL of concentrated HCl and 13 mL of ethanol, heat and stir, and add 4.3 g of SnCl 2 Dissolve in an appropriate amount of ethanol, add to the reaction solution, and stir to react. After the reaction is completed, filter and collect the white powder product to obtain the intermediate 1,2,4,5-benzenetetramine tetrahydrochloride.

[0044] Step 4: Dissolve 1 g of the intermediate 1,2,4,5-benzenetetraamine tetrahydrochloride in 125 mL of acetonitrile, stir, add 3.67 g of n-valeryl chloride, slowly drop 8.3 mL of triethylamine, stir to react, collect the white solid powder by suction, wash thoroughly and dry to obtain the nucleating agent 1,3,4,6-tetra-n-butylamidebenzene.

[0045] Final product structure data: 1 H NMR (400 MHz, DMSO-d 6 ): δ9.46(s,4H),7.62(s,2H), 2.25-2.32(m,8H),1.51-1.53(m,8H),1.26-1.28(m,8H),0.84-0.87(m,12H). HRMS m / z calcdfor C 26 H 42 N 4 O 4 [M+H] + :475.32; Found:475.44. Melting point range: 215-240℃.

[0046] Example 3

[0047] Preparation of 1,3,4,6-tetraisobutylamide benzene:

[0048] Step 1: Add 25 g of m-dichlorobenzene to a solution containing 80 mL of concentrated sulfuric acid and 7.3 g of potassium nitrate, and heat and stir to react. After the reaction is completed, extract and spin dry, and the crude product is separated and purified by column chromatography to obtain the intermediate product 1,5-dichloro-2,4-dinitrobenzene.

[0049] Step 2: Disperse 1 g of the intermediate 1,5-dichloro-2,4-dinitrobenzene obtained in step 1 in 7 mL of ethylene glycol, heat and stir, continue to bubble in ammonia gas, filter and dry the solid to obtain the intermediate 4,6-dinitro-1,3-phenylenediamine.

[0050] Step 3: Disperse 0.5 g of the intermediate 4,6-dinitro-1,3-phenylenediamine obtained in step 2 in a mixture of 26 mL of concentrated HCl and 13 mL of ethanol, heat and stir, and add 4.3 g of SnCl 2Dissolve in an appropriate amount of ethanol, add to the reaction solution, and stir to react. After the reaction is completed, filter and collect the white powder product to obtain the intermediate 1,2,4,5-benzenetetramine tetrahydrochloride.

[0051] Step 4: Dissolve 1 g of the intermediate 1,2,4,5-benzenetetraamine tetrahydrochloride in 125 mL of acetonitrile, stir, add 3.67 g of isovaleryl chloride, slowly drop 8.3 mL of triethylamine, stir to react, collect the white solid powder by suction, wash thoroughly and dry to obtain the nucleating agent 1,3,4,6-tetraisobutyramidebenzene.

[0052] Final product structure data: 1 H NMR (400 MHz, DMSO-d 6 ): δ9.39(s,4H),7.59(s,2H), 2.14-2.15(m,8H),1.97-2.12(m,4H),0.86-1.14(m,24H).HRMS m / z calcd for C 26 H 42 N 4 O 4 [M+H] + :475.32; Found:475.35. Melting point range: 215-240℃.

[0053] Example 4

[0054] Preparation of N,N',N",N"'-(benzene-1,2,4,5-tetrayl)tetrakis(2-ethylhexanamide):

[0055] Step 1: Add 25 g of m-dichlorobenzene to a solution containing 80 mL of concentrated sulfuric acid and 7.3 g of potassium nitrate, and heat and stir to react. After the reaction is completed, extract and spin dry, and the crude product is separated and purified by column chromatography to obtain the intermediate product 1,5-dichloro-2,4-dinitrobenzene.

[0056] Step 2: Disperse 1 g of the intermediate 1,5-dichloro-2,4-dinitrobenzene obtained in step 1 in 7 mL of ethylene glycol, heat and stir, continue to bubble in ammonia gas, filter and dry the solid to obtain the intermediate 4,6-dinitro-1,3-phenylenediamine.

[0057] Step 3: Disperse 0.5 g of the intermediate 4,6-dinitro-1,3-phenylenediamine obtained in step 2 in a mixture of 26 mL of concentrated HCl and 13 mL of ethanol, heat and stir, and add 4.3 g of SnCl 2 Dissolve in an appropriate amount of ethanol, add to the reaction solution, and stir to react. After the reaction is completed, filter and collect the white powder product to obtain the intermediate 1,2,4,5-benzenetetramine tetrahydrochloride.

[0058] Step 4: Dissolve 1 g of the intermediate 1,2,4,5-benzenetetramine tetrahydrochloride in 125 mL of acetonitrile, stir, add 9.42 g of 2-ethylhexanoyl chloride, slowly drop 8.3 mL of triethylamine, stir to react, collect the white solid powder by suction filtration, wash thoroughly and dry to obtain the nucleating agent N,N',N",N"'-(benzene-1,2,4,5-tetrayl)tetrakis(2-ethylhexanamide).

[0059] Final product structure data: 1 H NMR (400 MHz, DMSO-d 6 ):δ9.27(s,4H),7.56(s,2H), 2.43-2.41(m,4H),1.69-1.71(m,8H),1.56-1.58(m,8H),1.27-1.25(m,8H),1.21-1.17(m,8H),0.88-0.85(m,12H),0.84-0.83(m,12H).HRMS m / z calcd for C 38 H 66 N 4 O 4 [M+H] + :643.51; Found:643.77. Melting point range: 215-240℃.

[0060] Application Examples E1-E4

[0061] Preparation of polypropylene composition: 100 parts by weight of random copolymer polypropylene (Yangzi Petrochemical), 0.08 parts by weight of tetraamide benzene derivative prepared in Examples 1-4 as nucleating agent, 0.05 parts by weight of antioxidant 1010, 0.1 parts by weight of antioxidant 168, 0.05 parts by weight of calcium stearate were mixed evenly, mixed in a high-speed mixer at a speed of 800r / min for 10 minutes, and then extruded and granulated in a twin-screw extruder, the melt extrusion temperature was 190-210°C, and the blended pellets were dried and made into samples on an injection molding machine to obtain polypropylene compositions E1-E4 respectively. The sample number is consistent with the nucleating agent used, for example, the polypropylene composition using the nucleating agent of Example 1 is numbered E1, and so on. The random copolymer polypropylene without the addition of the nucleating agent was treated in the same way as a blank sample.

[0062] The prepared samples were subjected to mechanical property tests, and the test results are shown in Table 1. The higher the flexural modulus, the better the rigidity of the polymer. Among them, MFR (230°C, 2.16kg) was tested according to GB / T 3682.1-2018, and the flexural modulus was tested according to GB / T 9341-2008.

[0063] Table 1 Mechanical properties test of samples E1-E4

[0064]

[0065] As shown in the test data of samples E1-E4 in Table 1, after adding an effective amount of nucleating agent to the random copolymer polypropylene material, the flexural modulus of the polypropylene is improved. Unexpectedly, the flexural modulus first increases and then decreases, and the flexural modulus of E3 is particularly unexpectedly increased. This shows that at the same addition amount (0.08%), Example 3 has the best stiffness enhancement performance.

[0066] Application Examples E5-E8

[0067] The nucleating agent prepared in Example 3 was added in the amounts listed in Table 2, and polypropylene compositions E5 to E8 were obtained according to the preparation method of Application Example E3. Random copolymer polypropylene added with the same amounts of antioxidant 1010, antioxidant 168 and calcium stearate was used as a blank sample.

[0068] Table 2 Mechanical properties test of samples E3, E5-E8

[0069]

[0070] We unexpectedly found that when the addition amount is 0.08%, the effect is particularly excellent. As shown in the test data in Table 2, the addition amount is set to 0-0.20%, where the flexural modulus at 0-0.08% addition amount gradually increases, while the flexural modulus at 0.08%-0.20% addition amount shows a gradual downward trend, and the flexural modulus at 0.08% addition amount reaches a peak, indicating that 800ppm is the best addition amount with the best performance.

[0071] In summary, the tetraamide benzene derivative of the present invention can be used as a nucleating agent for polymers, especially polypropylene, has stiffness-enhancing properties, is an effective stiffness-enhancing additive for polypropylene, and can greatly expand the application field of polypropylene to meet market demand.

[0072] It should be understood by those skilled in the art that the embodiments of the present invention described above are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A method for preparing a tetraamide benzene derivative as a polypropylene nucleating agent, wherein the tetraamide benzene derivative is selected from any one of 1,3,4,6-tetra-n-butylamide benzene, 1,3,4,6-tetraisobutylamide benzene, N,N',N'',N'''-(benzene-1,2,4,5-tetrayl)tetrakis(2-ethylhexylamide), characterized in that: The steps include: S1, adding m-dichlorobenzene to the nitrating agent, heating and stirring to react, after the reaction is completed, separating and purifying to obtain the intermediate 1,5-dichloro-2,4-dinitrobenzene; S2, dispersing the intermediate 1,5-dichloro-2,4-dinitrobenzene obtained in step S1 in an appropriate amount of ethylene glycol, heating and stirring, adding an aminating agent, and separating and drying the solid after the reaction is completed to obtain the intermediate 4,6-dinitro-1,3-phenylenediamine; S3, dispersing the intermediate 4,6-dinitro-1,3-phenylenediamine obtained in step S2 in a mixed solution of concentrated HCl and ethanol, heating and stirring, dissolving a reducing agent in an appropriate amount of ethanol, adding the mixture to the reaction solution, stirring the reaction, and separating a white powder product after the reaction is completed to obtain the intermediate 1,2,4,5-benzenetetramine tetrahydrochloride; S4, dissolving the intermediate 1,2,4,5-benzenetetraamine tetrahydrochloride obtained in step S3 in acetonitrile, stirring, adding acyl chloride, slowly dropping weak base, stirring to react, and separating to obtain the tetraamide benzene derivative after the reaction is completed; the acyl chloride is selected from one or more of n-valeryl chloride, isovaleryl chloride or 2-ethylhexanoyl chloride.

2. The method according to claim 1, characterized in that The nitrating agent in step S1 is a concentrated sulfuric acid / potassium nitrate mixture or a concentrated sulfuric acid / concentrated nitric acid mixture; the amination agent in step S2 is ammonia gas; the reducing agent in step S3 is tin dichloride or metallic tin; and the weak base in step S4 is triethylamine, pyridine and its homologues.

3. Use of a tetraamide benzene derivative in a polypropylene nucleating agent, characterized in that: The tetraamide benzene derivative is selected from any one of 1,3,4,6-tetra-n-butylamide benzene, 1,3,4,6-tetraisobutylamide benzene, and N,N',N'',N'''-(benzene-1,2,4,5-tetrayl)tetrakis(2-ethylhexylamide).

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