Polypropylene nucleating agent, its preparation method and application

Abstract

The application discloses a polypropylene nucleating agent, which has a structure shown in formula I: the polypropylene nucleating agent has a symmetrical coplanar structure of multiple hydroxyl groups and amide bonds, the amide bonds are beneficial to the formation of beta crystals, and the impact resistance of the polypropylene material is improved. Due to the fact that the amide bonds and the hydroxyl groups can form intermolecular hydrogen bonds, when heated, the hydrogen bonds are dissociated, free nucleating agent molecules are generated in a polypropylene melt, and under the action of a benzene ring, a single molecule rotates in a coplanar direction; when cooled, the hydrogen bonds are combined, the self-assembly of the free nucleating agent molecules is initiated, a spatial reticular supramolecular aggregate is formed, four hydroxyl structures at end group positions support the formation of a hexagonal structure between two adjacent nucleating agent molecules, the spatial reticular structure of the supramolecular aggregate is stabilized, nucleation sites are provided for polypropylene chains, the arrangement and accumulation of the molecular chains are promoted, nucleation is promoted, and therefore the haze of the polypropylene material is reduced.

Description

Technical Field

[0001] This invention belongs to the field of nucleating agent technology, specifically relating to a polypropylene nucleating agent, its preparation method, and its application. Background Technology

[0002] Polypropylene (PP), as a semi-crystalline polymer, has molecules in its amorphous portion distributed randomly, while those in its crystalline portion are arranged in a helical, regular pattern. The crystallization process of PP includes two stages: nucleus formation and grain growth. Nucleus formation is divided into homogeneous nucleation and heterogeneous nucleation. Homogeneous nucleation occurs when the polymer chains in the melt undergo thermal motion to form ordered chain bundles, further forming nuclei. This method results in poor processing and application performance of PP products. Heterogeneous nucleation occurs when "solid impurities" or intact PP nuclei are present in the PP melt, and the PP molecular chains adsorb and arrange themselves orderly on the surface of the "impurities" to form nuclei. The presence of impurities significantly affects the PP crystallization process; substances that play a nucleation role and promote crystallization during this process are called nucleating agents.

[0003] When PP melt undergoes homogeneous nucleation and crystallization at a temperature slightly below its melting point, a slower cooling rate results in a grain growth rate exceeding the nucleus formation rate, easily producing a small number of large spherulites with high crystallinity. Conversely, a faster cooling rate leads to a high nucleus formation rate, easily generating small spherulites with lower crystallinity and poorer mechanical properties in the PP product. The introduction of nucleating agents accelerates nucleus formation without affecting the grain growth rate. This allows PP to achieve finer grains and higher grain density even at higher temperatures, completely opposite to the phenomenon observed in homogeneous nucleation. Therefore, nucleating agents accelerate PP crystallization, raising the crystallization temperature by approximately 20°C, increasing the crystallization rate, and improving overall crystallinity. By improving crystallization behavior and crystal form, PP forms regular crystals, increasing the crystallinity and crystallization temperature of the product, reducing the processing cycle, and improving material properties (such as transparency, surface gloss, load deformation temperature, and impact resistance). This is the foundation of PP crystallization modification, and nucleating agents are currently widely used in PP production and processing.

[0004] Based on their chemical structures, PP nucleating agents can be divided into inorganic nucleating agents and organic nucleating agents. Inorganic nucleating agents suffer from poor compatibility and uneven dispersion with PP. Compared to inorganic nucleating agents, organic nucleating agents exhibit better compatibility with the polypropylene matrix, higher nucleation efficiency, and significantly superior nucleation effects, making them the main polypropylene nucleating agents currently used. Alpha and beta crystal forms are common PP crystal forms. Commercially available PP is predominantly alpha crystal form. Beta crystal form is less stable than alpha crystal form and requires specific conditions (such as rapid cooling of the melt to a certain temperature for crystallization, vibration-induced crystallization, shearing and stretching during crystallization, or the addition of a beta crystal nucleating agent) to form. Therefore, PP nucleating agents can be classified into alpha and beta nucleating agents. Alpha nucleating agents can improve the rigidity and transparency of PP, while beta nucleating agents can improve the toughness and load deformation temperature of PP. Research on beta nucleating agents began in the 20th century, and to date, a series of products with high practical value have been developed. For example, Chinese patent document CN 114835949 A discloses a polypropylene composite nucleating agent based on a glucose acetal derivative, composed of two components: a glucose acetal derivative and an organophosphate. The glucose acetal derivative has multiple hydrogen bonding sites, forming fibrous crystals under intermolecular hydrogen bonding, providing active nucleation sites for macromolecular chain crystallization. The prepared glucose acetal derivative nucleating agent can improve the transparency and processing performance of the material. Chinese patent document CN113621175A discloses a highly efficient isotactic polypropylene β-crystal nucleating agent. This nucleating agent has two symmetrical or asymmetrical amide structures. Compared with unmodified polypropylene samples, polypropylene modified with this nucleating agent has 3-4 times improved impact performance. Chinese patent document CN102898724A discloses a finely refined amide-type β-polypropylene nucleating agent. This finely refined amide-type β-polypropylene nucleating agent has a narrow number-average particle size distribution and can be uniformly dispersed. When used to prepare polypropylene materials, it can significantly improve the impact strength of polypropylene materials and improve the flexural modulus, crystallization temperature, and other physical properties of polypropylene materials.

[0005] However, polypropylene prepared using existing β-nucleating agents generally suffers from high haze and low impact strength, which cannot meet the requirements for applications such as low-temperature transparent food packaging. Summary of the Invention

[0006] In view of the problems existing in the prior art and the directions for improvement, the present invention provides a polypropylene nucleating agent to solve the problems of high haze and the need to improve the impact strength of polypropylene produced by existing polypropylene nucleating agents.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A polypropylene nucleating agent having the structure shown in Formula I:

[0009]

[0010] R1 is selected from unsubstituted or substituted C6-C20 aryl groups. or Where * indicates a junction with an oxygen atom, This is the junction with the nitrogen atom;

[0011] R2 is selected from C1-C20 straight-chain or branched alkylene groups, C6-C20 cycloalkylene groups, or C6-C20 arylene groups.

[0012] In the above definition of R1, the substituted C6-C20 arylene means that at least one H in the C6-C20 arylene is replaced by a C1-C6 straight-chain or branched alkyl group, such as methyl, ethyl, propyl, isopropyl, tert-butyl, isopentyl, etc.

[0013] Optionally, in the polypropylene nucleating agent provided by the present invention, R1 is selected from... Where * indicates a junction with an oxygen atom, (At the junction with the nitrogen atom).

[0014] Optionally, in the polypropylene nucleating agent provided by the present invention, R2 is selected from methylene, ethylene, propylene (-CH2CH2CH2-), any one of them, in which, This is the junction with the carbonyl group (C=O).

[0015] This invention also provides a method for preparing a polypropylene nucleating agent, comprising the following steps:

[0016]

[0017] Step 1: The alkanolamine compound shown in Formula II undergoes an amidation reaction with the dicarboxylic acid shown in Formula III under the action of a condensing agent to obtain the compound shown in Formula IV;

[0018] Step 2: The compound shown in Formula IV undergoes a substitution reaction with ethyl bromoethyl to obtain the compound shown in Formula V;

[0019] Step 3: The compound shown in Formula V reacts with diethanolamine via an amino ester exchange reaction to obtain the polypropylene nucleating agent shown in Formula I;

[0020] The definitions of R1 and R2 are as described above.

[0021] Optionally, in the preparation method of the polypropylene nucleating agent provided by the present invention, the condensing agent used in the amidation reaction is 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) and 1-hydroxybenzotriazole (HOBt); preferably, the molar ratio of the alkanolamine compound shown in Formula II, the dicarboxylic acid shown in Formula III, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and 1-hydroxybenzotriazole is (2.2-3):1:(2.5-3.5):(1.1-1.3).

[0022] Optionally, in the preparation method of the polypropylene nucleating agent provided by the present invention, the substitution reaction is carried out under the action of an alkaline catalyst. Preferably, the alkaline catalyst is selected from potassium carbonate or sodium carbonate; more preferably, the molar ratio of the compound shown in Formula IV, the ethyl bromoacetate and the alkaline catalyst is 1:(2-4):(3-4).

[0023] Optionally, in the preparation method of the polypropylene nucleating agent provided by the present invention, the compound shown in Formula V undergoes an amino-ester exchange reaction with diethanolamine in the presence of an alkali; preferably, the alkali is selected from potassium carbonate or sodium carbonate; more preferably, the molar ratio of the compound shown in Formula V, the diethanolamine and the alkaline substance is 1:(2-4):(3-4).

[0024] The present invention also provides a polypropylene composition comprising polypropylene and a nucleating agent, wherein the nucleating agent is selected from the polypropylene nucleating agent described above or a polypropylene nucleating agent prepared by the above-described method; preferably, the mass ratio of the polypropylene nucleating agent to the polypropylene is (2-5):100.

[0025] Optionally, the polypropylene composition provided by the present invention further includes an antioxidant and an acid remover; wherein, the amount of antioxidant and acid remover is not limited, and can be adjusted according to actual conditions using industry conventions. The recommended mass ratio of antioxidant to polypropylene in the present invention is (0.05-0.2):100; and the mass ratio of acid remover to polypropylene is (0.2-0.7):100.

[0026] Optionally, in the polypropylene composition provided by the present invention, the oxygen scavenger and the acid remover can be conventional in the industry, such as the antioxidant being selected from at least one of hindered phenolic, phosphite and sulfate antioxidants; the antioxidant recommended by the present invention is selected from 1010 and / or 168.

[0027] The acid remover is selected from at least one of hydrotalcite, calcium stearate and zinc chloride.

[0028] Optionally, in the polypropylene composition provided by the present invention, the polypropylene is selected from homopolymer polypropylene and / or copolymer polypropylene; preferably, the copolymer polypropylene is a random copolymer or block copolymer of terminal olefin / cyclic olefin and propylene, wherein the terminal olefin / cyclic olefin is selected from at least one of ethylene, C4-C8 α-olefin, vinylcyclohexane, vinylcyclohexene and norbornene; more preferably, the polypropylene is selected from at least one of homopolymer polypropylene, random copolymer of propylene and ethylene, and block copolymer of propylene and ethylene.

[0029] Optionally, the preparation method of the polypropylene composition provided by the present invention is not specifically limited, and any conventional method in the industry can be used. For example, polypropylene, nucleating agent, antioxidant, and acid remover can be melt-blended, granulated, and processed to obtain a polypropylene composition product. Preferably, the processing method is selected from at least one of injection molding, extrusion, blow molding, thermoforming, and foaming.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] The polypropylene nucleating agent provided by this invention has a symmetrical coplanar structure of multiple hydroxyl groups and amide bonds. The amide bonds facilitate the formation of β-crystals, improving the impact resistance of polypropylene materials. Furthermore, since the amide bonds and hydroxyl groups can form intermolecular hydrogen bonds, upon heating, these hydrogen bonds dissociate, generating free nucleating agent molecules in the polypropylene melt. Under the influence of the benzene ring, individual molecules rotate in the coplanar direction. Upon cooling, the hydrogen bonds re-bond, initiating the self-assembly of the free nucleating agent molecules to form a spatial network supramolecular aggregate. The four hydroxyl structures at the terminal positions support the formation of hexagonal structures between adjacent nucleating agent molecules, which helps stabilize the spatial network structure of the supramolecular aggregate, providing nucleation sites for the polypropylene chains, promoting orderly chain arrangement and stacking, and thus reducing the haze of the polypropylene material. The polypropylene nucleating agent provided by this invention can simultaneously improve the transparency and impact resistance of polypropylene materials, making it a highly efficient nucleating agent with promising industrial application prospects. Detailed Implementation

[0032] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0033] For any experimental steps or conditions not specified in the examples and comparative examples, the procedures and conditions described in the literature in this field can be followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0034] Example 1

[0035] The structure of nucleating agent N1 is shown below, and the specific preparation steps are as follows:

[0036]

[0037] (1) Add 2,6-naphthalenedicarboxylic acid (2.2 g, 10 mmol, 216.19 g / mol, Aladdin reagent, ≥98.0%), 4-amino-3-methylphenol (2.7 g, 22 mmol, 123.15 g / mol, Aladdin reagent, 98%), EDC (4.8 g, 25 mmol, 191.7 g / mol, Aladdin reagent, 98%), and HOBt (1.5 g, 11 mmol, ≥98%) to the reaction vessel. 135.13 g / mol, Maclean's reagent, ≥97.0%, 60 mL anhydrous dichloromethane (Aladdin's reagent, ≥99.8%), reacted at room temperature for 24 hours. After the reaction was completed, the mixture was washed with 10% NaOH solution and deionized water, and separated. The organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain 4.1 g of intermediate (the compound shown in Formula IV, R2 is naphthylene, R1 is methyl-substituted phenylene) (9.5 mmol, 426 g / mol);

[0038] (2) Add 4.1 g of intermediate (compound shown in Formula IV), anhydrous sodium carbonate (3.0 g, 28.5 mmol, 105.99 g / mol, Aladdin reagent, ≥99.5%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (3.5 g, 21 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Separate by column chromatography to obtain 5.0 g of intermediate (compound shown in Formula V, R2 and R1 are the same as in step 1) (8.4 mmol, 598 g / mol).

[0039] (3) Add 4.8 g of intermediate (the compound shown in Formula V), anhydrous sodium carbonate (2.7 g, 25.2 mmol, 105.99 g / mol, Aladdin reagent, ≥99.5%), diethanolamine (2.2 g, 21 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N1 by column chromatography. The structure was verified to be correct by NMR.

[0040] 1H NMR(400MHZ,DMSO)δ7.52(s,2H),7.37(t,2H),6.93(t,2H),6.85(t,2H),7.43-7.37(m,2H),6.6 1-6.69(m,4H),4.84(s,4H),4.59(dd,2H),4.47(dd,2H),3.39(t,8H),3.32(m,8H),2.42(d,6H).

[0041] Example 2

[0042] The structure of nucleating agent N2 is shown below, and the specific preparation steps are as follows:

[0043]

[0044] (1) Add terephthalic acid (1.7 g, 10 mmol, 166.13 g / mol, Aladdin reagent, 99.0%), 4-amino-3,5-dimethylphenol (3.6 g, 26 mmol, 137.18 g / mol, Aladdin reagent, >98%), EDC (6.5 g, 34 mmol, 191.7 g / mol, Aladdin reagent, 98%), and HOBt (1.8 g, 13 mmol, ...) to the reaction vessel. 135.13 g / mol, Maclean's reagent, ≥97.0%, 60 mL anhydrous dichloromethane (Aladdin's reagent, ≥99.8%), reacted at room temperature for 24 hours. After the reaction was completed, the mixture was washed with 10% NaOH solution and deionized water, and separated. The organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain 3.6 g of intermediate (the compound shown in Formula IV, where R2 is phenylene and R1 is dimethyl-substituted phenylene) (8.8 mmol, 404 g / mol).

[0045] (2) Add 3.6 g of intermediate (compound shown in Formula IV), anhydrous potassium carbonate (4.6 g, 33.4 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (3.2 g, 19.4 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Column chromatography is used to separate 4.8 g of intermediate (compound shown in Formula V, R2 and R1 are the same as in step 1) (8.4 mmol, 576 g / mol).

[0046] (3) Add 4.8 g of intermediate (the compound shown in Formula V), anhydrous sodium carbonate (3.2 g, 30.8 mmol, 105.14 g / mol, Aladdin reagent, 99%), diethanolamine (1.9 g, 17.6 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N2 by column chromatography. The structure was verified to be correct by NMR.

[0047] Example 3

[0048] The structure of nucleating agent N3 is shown below, and the specific preparation steps are as follows:

[0049]

[0050] (1) Add p-malonic acid (1.0 g, 10 mmol, 104.06 g / mol, Aladdin reagent, 99.0%), 4-(2-amino-2-methylpropyl)phenol (3.6 g, 22 mmol, 165.23 g / mol, Aladdin reagent, 98%), EDC (5.4 g, 28 mmol, 191.7 g / mol, Aladdin reagent, 98%), HOBt (1.6 g, 12 mmol, 135.13 g / mol, Maclean's reagent, ≥97.0%), and 60 mL of anhydrous dichloromethane (Aladdin reagent, ≥99.8%) to the reaction vessel. React at room temperature for 24 hours. After the reaction, wash with 10% NaOH solution and deionized water respectively, and separate the liquids. Dry the organic phase with anhydrous sodium sulfate and distill under reduced pressure to obtain 3.6 g of intermediate (the compound shown in Formula IV, where R2 is methylene and R1 is...). (9.6 mmol, 370.17 g / mol);

[0051] (2) Add 3.6 g of intermediate (the compound shown in Formula IV), anhydrous potassium carbonate (4.6 g, 33.6 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (5.9 g, 35.5 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Column chromatography is used to separate the intermediate product 4.9 g (the compound shown in Formula V, R2 and R1 are the same as in step 1) (9.0 mmol, 542 g / mol).

[0052] (3) Add 4.9 g of intermediate (the compound shown in Formula V), anhydrous sodium carbonate (3.8 g, 36.0 mmol, 105.14 g / mol, Aladdin reagent, 99%), diethanolamine (3.6 g, 34.2 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N3 by column chromatography. The structure was verified to be correct by NMR.

[0053] Example 4

[0054] The structure of nucleating agent N4 is shown below, and the specific preparation steps are as follows:

[0055]

[0056] (1) Add p-1,4-cyclohexanedicarboxylic acid (1.7 g, 10 mmol, 172.18 g / mol, Aladdin reagent, 99.0%), 2-amino-5-methylphenol (3.7 g, 30 mmol, 123.15 g / mol, Aladdin reagent, 98%), EDC (6.3 g, 33 mmol, 191.7 g / mol, Aladdin reagent, 98%), and HOBt (1.8 g, 13 mmol, 1...) to the reaction vessel. 35.13 g / mol (Maclean's reagent, ≥97.0%), 60 mL of anhydrous dichloromethane (Aladdin's reagent, ≥99.8%), reacted at room temperature for 24 hours. After the reaction was completed, the mixture was washed with 10% NaOH solution and deionized water, and separated. The organic phase was dried over anhydrous sodium sulfate and distilled under reduced pressure to obtain 3.1 g of intermediate (the compound shown in Formula IV, R2 is cyclohexylene, R1 is methyl-substituted phenylene) (8.1 mmol, 382.17 g / mol);

[0057] (2) Add 3.1 g of intermediate (compound shown in formula IV), anhydrous sodium carbonate (3.3 g, 31.6 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (4.5 g, 26.7 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Column chromatography is used to separate the intermediate product (compound shown in formula V, R2 and R1 are the same as in step 1) (7.1 mmol, 544.19 g / mol).

[0058] (3) Add 3.9 g of intermediate (the compound shown in Formula V), anhydrous potassium carbonate (3.0 g, 22 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), diethanolamine (1.9 g, 17.8 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N4 by column chromatography. The structure was verified to be correct by NMR.

[0059] Example 5

[0060] The structure of nucleating agent N5 is shown below, and the specific preparation steps are as follows:

[0061]

[0062] (1) Add p-glutaric acid (1.3g, 10mmol, 132.11g / mol, Aladdin reagent, 99.0%), p-aminophenol (2.4g, 22mmol, 109.13g / mol, Maclean's reagent, ≥98%), EDC (4.8g, 25mmol, 191.7g / mol, Aladdin reagent, 98%), HOBt (1.5g, 11mmol, 135.13g / mol, Maclean's reagent, ≥97.0%), and 60mL of anhydrous dichloromethane (Aladdin reagent, ≥99.8%) to the reaction vessel. React at room temperature for 24 hours. After the reaction is completed, wash with 10% NaOH solution and deionized water respectively and separate the liquids. Dry the organic phase with anhydrous sodium sulfate and distill under reduced pressure to obtain 3.1g of intermediate (the compound shown in Formula IV, R2 is propylene, R1 is phenylene) (9.8mmol, 314.11g / mol);

[0063] (2) Add 3.1 g of intermediate (compound shown in Formula IV), anhydrous sodium carbonate (3.1 g, 29.4 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (3.6 g, 21.6 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Column chromatography is used to separate 4.4 g of intermediate (compound shown in Formula V, R2 and R1 are the same as in step 1) (9.1 mmol, 486.4 g / mol).

[0064] (3) Add 4.4 g of intermediate (the compound shown in Formula V), anhydrous potassium carbonate (3.8 g, 27.3 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), diethanolamine (2.5 g, 23.7 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N5 by column chromatography. The structure was verified to be correct by NMR.

[0065] Example 6

[0066] The structure of nucleating agent N6 is shown below, and the specific preparation steps are as follows:

[0067]

[0068] (1) Terephthalic acid (1.7 g, 10 mmol, 166.13 g / mol, Aladdin reagent, 99.0%), p-aminophenol (2.7 g, 25 mmol, 109.13 g / mol, Maclean's reagent, ≥98%), EDC (5.6 g, 29 mmol, 191.7 g / mol, Aladdin's reagent, 98%), HOBt (1.6 g, 12 mmol, 135.13 g / mol, Maclean's reagent, ≥97.0%), and 60 mL of anhydrous dichloromethane (Aladdin's reagent, ≥99.8%) were added to the reaction vessel. The reaction was carried out at room temperature for 24 hours. After the reaction was completed, the mixture was washed with 10% NaOH solution and deionized water, and the organic phase was dried with anhydrous sodium sulfate. The mixture was then distilled under reduced pressure to obtain 3.3 g of intermediate (the compound shown in Formula IV, R2 is phenylene, R1 is phenylene) (9.5 mmol, 348.1 g / mol).

[0069] (2) Add 3.3 g of intermediate (compound shown in Formula IV), anhydrous potassium carbonate (5.0 g, 36.1 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (5.7 g, 34.2 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Column chromatography is used to separate 4.5 g of intermediate (compound shown in Formula V, R2 and R1 are the same as in step 1) (8.6 mmol, 520.12 g / mol).

[0070] (3) Add 4.5 g of intermediate (the compound shown in formula V), anhydrous potassium carbonate (3.9 g, 28.4 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), diethanolamine (2.0 g, 18.9 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N6 by column chromatography. The structure was verified to be correct by NMR.

[0071] Example 7

[0072] The structure of nucleating agent N7 is shown below, and the specific preparation steps are as follows:

[0073]

[0074] (1) Add 1,4-cyclohexanedicarboxylic acid (1.7 g, 10 mmol, 172.18 g / mol, Aladdin reagent, 99.0%), 4-amino-3-methylphenol (2.8 g, 26 mmol, 123.15 g / mol, Aladdin reagent, 98%), EDC (6.3 g, 33 mmol, 191.7 g / mol, Aladdin reagent, 98%), and HOBt (1.8 g, 13 mmol, 1...) to the reaction vessel. 35.13 g / mol, Maclean's reagent, ≥97.0%, 60 mL anhydrous dichloromethane (Aladdin's reagent, ≥99.8%), reacted at room temperature for 24 hours. After the reaction was completed, the mixture was washed with 10% NaOH solution and deionized water, and separated. The organic phase was dried with anhydrous sodium sulfate and distilled under reduced pressure to obtain 3.4 g of intermediate (the compound shown in Formula IV, R2 is cyclohexylene, R1 is methyl-substituted phenylene) (8.8 mmol, 382.17 g / mol);

[0075] (2) Add 3.4 g of intermediate (compound shown in Formula IV), anhydrous potassium carbonate (4.3 g, 30.8 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (4.4 g, 26.4 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Column chromatography is used to separate 4.2 g of intermediate (compound shown in Formula V, R2 and R1 are the same as in step 1) (7.5 mmol, 554.19 g / mol).

[0076] (3) Add 4.2 g of intermediate (the compound shown in formula V), anhydrous potassium carbonate (3.6 g, 26.3 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), diethanolamine (2.0 g, 18.8 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N7 by column chromatography. The structure was verified to be correct by NMR.

[0077] Example 8

[0078] The structure of nucleating agent N8 is shown below, and the specific preparation steps are as follows:

[0079]

[0080] (1) Terephthalic acid (1.7 g, 10 mmol, 166.13 g / mol, Aladdin reagent, 99.0%), 7-amino-2-naphthol (3.5 g, 22 mmol, 159.19 g / mol, Aladdin reagent), EDC (5.4 g, 28 mmol, 191.7 g / mol, Aladdin reagent, 98%), HOBt (1.8 g, 13 mmol, 135.13 g / mol, Maclean's reagent, ≥97.0%), and 60 mL of anhydrous dichloromethane (Aladdin reagent, ≥99.8%) were added to the reaction vessel. The reaction was carried out at room temperature for 24 hours. After the reaction was completed, the mixture was washed with 10% NaOH solution and deionized water, and the organic phase was dried with anhydrous sodium sulfate. The mixture was then distilled under reduced pressure to obtain 4.1 g of intermediate (the compound shown in Formula IV, where R2 is phenylene and R1 is naphthylene) (9.2 mmol, 448.13 g / mol).

[0081] (2) Add 4.1 g of intermediate (compound shown in formula IV), anhydrous potassium carbonate (3.8 g, 27.6 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (5.1 g, 30.4 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Column chromatography is used to separate 5.4 g of intermediate (compound shown in formula V, R2 and R1 are the same as in step 1) (8.7 mmol, 620.15 g / mol).

[0082] (3) Add 5.4 g of intermediate (the compound shown in formula V), anhydrous potassium carbonate (4.2 g, 30.5 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), diethanolamine (2.0 g, 19.1 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N8 by column chromatography. The structure was verified to be correct by NMR.

[0083] Example 9

[0084] The specific preparation steps for nucleating agent N9 are as follows:

[0085]

[0086] (1) Malonic acid (1.0 g, 10 mmol, 104.06 g / mol, Aladdin reagent, 99.0%), 2-amino-4-tert-pentylphenol (5.0 g, 28 mmol, 179.25 g / mol, Aladdin reagent), EDC (5.4 g, 28 mmol, 191.7 g / mol, Aladdin reagent, 98%), HOBt (1.8 g, 13 mmol, 135.13 g / mol, Maclean's reagent, ≥97.0%), and 60 mL of anhydrous dichloromethane (Aladdin reagent, ≥99.8%) were added to the reaction vessel. The reaction was carried out at room temperature for 24 hours. After the reaction was completed, the mixture was washed with 10% NaOH solution and deionized water, and the liquid phase was separated. The organic phase was dried over anhydrous sodium sulfate and distilled under reduced pressure to obtain 3.8 g of intermediate (the compound shown in Formula IV, where R2 is methylene and R1 is...). (9.0 mmol, 426.24 g / mol);

[0087] (2) Add 3.8 g of intermediate (compound shown in formula IV), anhydrous potassium carbonate (4.7 g, 34.2 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), and 60 mL of acetone to the reaction vessel. Stir at room temperature until the solid is completely dissolved, then add ethyl bromoacetate (5.4 g, 32.4 mmol, 167 g / mol, Aladdin reagent, 98%). Reflux under nitrogen protection for 20 hours. Use petroleum ether / ethyl acetate as the mobile phase. Column chromatography is used to separate 5.1 g of intermediate (compound shown in formula V, R2 and R1 are the same as in step 1) (8.5 mmol, 598.62 g / mol).

[0088] (3) Add 5.1 g of intermediate (the compound shown in formula V), anhydrous potassium carbonate (3.9 g, 28.1 mmol, 138.21 g / mol, Aladdin reagent, ≥99.5%), diethanolamine (2.6 g, 25.5 mmol, 105.14 g / mol, Aladdin reagent, 99%), and 60 mL of ethanol to the reaction vessel. Reflux under nitrogen protection for 8 hours. Use dichloromethane / methanol as the mobile phase. Separate the nucleating agent N9 by column chromatography. The structure was verified to be correct by NMR.

[0089] Example 10

[0090] This embodiment provides a polypropylene composition, and the specific preparation steps are as follows:

[0091] Based on 100% polypropylene by weight, nucleating agent N 12wt%, antioxidant 1010 0.15wt%, and calcium stearate 0.7wt% were added to a high-speed mixer at 800 rpm and mixed for 10 minutes. After thorough mixing in the high-speed mixer, the mixture was extruded and granulated using a HAAKE 40 twin-screw extruder from Haake GmbH, Germany, at an extrusion temperature of 210℃. Then, it was injected into a standard specimen using a UN-100 injection molding machine from Liuzhou Injection Molding Machinery Factory at an injection temperature of 230℃, and designated as specimen #1.

[0092] Examples 11-23

[0093] The polypropylene compositions and their preparation methods provided in Examples 11-23 are similar to those in Example 10, except that the raw materials and amounts used are different, as shown in the table below.

[0094] Table 1

[0095]

[0096]

[0097] Note: The amounts of each substance in the examples in this table are based on the mass of the corresponding polypropylene as 100%.

[0098] Comparative Example 1

[0099] Homopolymer polypropylene with a melt index of 12 g / 10 min, along with 3 wt% of nucleating agent N,N'-diphenyl terephthalamide (DPHT), 0.15 wt% of antioxidant 1010, and 0.5 wt% of calcium stearate, were added to a high-speed mixer at 800 r / min and mixed for 10 minutes. After homogenization in the high-speed mixer, the mixture was extruded and granulated using a HAAKE 40 twin-screw extruder from Haake GmbH, Germany, at an extrusion temperature of 210℃. The granulated sample was then injection molded using a UN-100 injection molding machine from Liuzhou Injection Molding Machinery Factory at a molding temperature of 230℃ to produce the comparative example 1 specimen.

[0100] Comparative Example 2

[0101] Homopolymer polypropylene with a melt index of 12 g / 10 min, 3 wt% nucleating agent (as shown in Formula VI below), 0.15 wt% antioxidant 1010, and 0.5 wt% calcium stearate were added to a high-speed mixer at 800 r / min and mixed for 10 minutes. After homogenization in the high-speed mixer, the mixture was extruded and granulated using a HAAKE 40 twin-screw extruder from Haake GmbH, Germany, at an extrusion temperature of 210℃. The granules were then injected into samples (Comparative Example 2) using a UN-100 injection molding machine from Liuzhou Injection Molding Machinery Factory at an injection temperature of 230℃.

[0102]

[0103] Comparative Example 3

[0104] Ethylene-propylene random copolymer polypropylene with a melt index of 10 g / 10 min, along with 3 wt% of nucleating agent N,N'-diphenyl terephthalamide (DPHT), 0.15 wt% of antioxidant 1010, and 0.5 wt% of calcium stearate, were added to a high-speed mixer at 800 r / min and mixed for 10 minutes. After homogenization in the high-speed mixer, the mixture was extruded and granulated using a HAAKE 40 twin-screw extruder from Haake GmbH, Germany, at an extrusion temperature of 210℃. The granules were then injection molded using a UN-100 injection molding machine from Liuzhou Injection Molding Machinery Factory at an injection temperature of 230℃ to prepare three comparative sample specimens.

[0105] Comparative Example 4

[0106] Ethylene-propylene random copolymer polypropylene with a melt index of 10 g / 10 min, 3 wt% nucleating agent (as shown in Formula VI), 0.15 wt% antioxidant 1010, and 0.5 wt% calcium stearate were added to a high-speed mixer at 800 r / min and mixed for 10 minutes. After homogenization in the high-speed mixer, the mixture was extruded and granulated using a HAAKE 40 twin-screw extruder from Haake GmbH, Germany, at an extrusion temperature of 210℃. The granules were then injected into samples (Comparative Example 4) using a UN-100 injection molding machine from Liuzhou Injection Molding Machinery Factory at an injection temperature of 230℃.

[0107]

[0108] Preparation of blank sample 1 in Comparative Example 5

[0109] Homopolymer polypropylene with a melt index of 12 g / 10 min, antioxidant 1010 (0.15 wt% by weight of the homopolymer polypropylene), and calcium stearate (0.5 wt% by weight) were added to a high-speed mixer at 800 r / min and mixed for 10 minutes. After thorough mixing in the high-speed mixer, the mixture was extruded and granulated using a HAAKE 40 twin-screw extruder from Haake GmbH, Germany, at an extrusion temperature of 210℃. The granulated sample was then prepared as blank control by injection molding at 230℃ using a UN-100 injection molding machine from Liuzhou Injection Molding Machinery Factory.

[0110] Preparation of blank sample 2 in Comparative Example 6

[0111] Ethylene-propylene random copolymer polypropylene with a melt index of 10 g / 10 min, antioxidant 1010 (0.15 wt% by weight of the copolymer), and calcium stearate (0.5 wt% by weight) were added to a high-speed mixer at 800 r / min and mixed for 10 minutes. After homogenization in the high-speed mixer, the mixture was extruded and granulated using a HAAKE 40 twin-screw extruder from Haake GmbH, Germany, at an extrusion temperature of 210℃. The granulated sample was then prepared as a blank control using a UN-100 injection molding machine from Liuzhou Injection Molding Machinery Factory at an injection temperature of 230℃.

[0112] The mechanical properties of the samples prepared in each embodiment and comparative example were tested according to the following methods: The impact strength of the simply supported beam was tested according to GB / T 1043—2008, with a notch depth of 2.0 mm; the optical properties were tested according to GB / T 2410—2008. The test results are shown in the table below.

[0113] Table 2 Sample Performance Tests

[0114]

[0115]

[0116] As shown in the table above, the nucleating agent provided by this invention significantly reduces the haze of polypropylene compared to β-nucleating agents without hydroxyl substitution; compared to glucose derivative nucleating agents, it has even lower haze while significantly improving the impact resistance of polypropylene. This indicates that the polypropylene nucleating agent provided by this invention has the functions of improving the transparency and impact resistance of polypropylene, making it a highly efficient polypropylene additive.

[0117] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A polypropylene nucleating agent, characterized in that, It has the structure shown in Equation I: Wherein, R2 is selected from C1-C20 straight-chain or branched alkylene groups, C6-C20 cycloalkylene groups, or C6-C20 arylene groups. R1 is selected from The asterisk (*) indicates a junction with an oxygen atom. This is the junction with the nitrogen atom.

2. The polypropylene nucleating agent as described in claim 1, characterized in that, R2 is selected from methylene, ethylene, propylene, Any one of them.

3. A method for preparing a polypropylene nucleating agent, characterized in that, Includes the following steps: Step 1: The alkanolamine compound shown in Formula II undergoes an amidation reaction with the dicarboxylic acid shown in Formula III under the action of a condensing agent to obtain the compound shown in Formula IV; Step 2: The compound shown in Formula IV undergoes a substitution reaction with ethyl bromoethyl to obtain the compound shown in Formula V; Step 3: The compound shown in Formula V reacts with diethanolamine via an amino ester exchange reaction to obtain the polypropylene nucleating agent shown in Formula I; The definitions of R1 and R2 are as described in claim 1 or 2.

4. The method for preparing the polypropylene nucleating agent as described in claim 3, characterized in that, The molar ratio of the alkanolamine compound shown in Formula II, the dicarboxylic acid shown in Formula III, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, and 1-hydroxybenzotriazole is (2.2-3):1:(2.5-3.5):(1.1-1.3).

5. The method for preparing the polypropylene nucleating agent as described in claim 3, characterized in that, The substitution reaction is carried out in the presence of a basic catalyst.

6. The method for preparing the polypropylene nucleating agent as described in claim 3, characterized in that, In the presence of a base, the compound shown in Formula V undergoes an amino-ester exchange reaction with diethanolamine.

7. The method for preparing the polypropylene nucleating agent as described in claim 5, characterized in that, The alkaline catalyst is selected from potassium carbonate or sodium carbonate.

8. The method for preparing the polypropylene nucleating agent as described in claim 5, characterized in that, The molar ratio of the compound shown in Formula IV, the ethyl bromoacetate, and the basic catalyst is 1:(2-4):(3-4).

9. The method for preparing the polypropylene nucleating agent as described in claim 6, characterized in that, The alkali is selected from potassium carbonate or sodium carbonate.

10. The method for preparing the polypropylene nucleating agent as described in claim 6, characterized in that, The molar ratio of the compound shown in Formula V, the diethanolamine, and the base is 1:(2-4):(3-4).

11. A polypropylene composition, characterized in that, It includes polypropylene and a nucleating agent, wherein the nucleating agent is selected from the polypropylene nucleating agent according to claim 1 or 2 or the polypropylene nucleating agent prepared by the preparation method of the polypropylene nucleating agent according to any one of claims 3-10.

12. The polypropylene composition according to claim 11, characterized in that, The polypropylene composition also includes antioxidants and acid removers.

13. The polypropylene composition according to claim 12, characterized in that, The antioxidant is selected from at least one of hindered phenolic, phosphite, and sulfate antioxidants; The acid remover is selected from at least one of hydrotalcite, calcium stearate and zinc chloride.

14. The polypropylene composition according to claim 11, characterized in that, The polypropylene is selected from homopolymer polypropylene and / or copolymer polypropylene.

15. The polypropylene composition according to claim 11, characterized in that, The mass ratio of the polypropylene nucleating agent to the polypropylene is (2-5):

100.

16. The polypropylene composition according to claim 12, characterized in that, The mass ratio of the antioxidant to the polypropylene is (0.05-0.2):100; the mass ratio of the acid remover to the polypropylene is (0.2-0.7):

100.

17. The polypropylene composition according to claim 13, characterized in that, The antioxidant is selected from 1010 and / or 168.

18. The polypropylene composition according to claim 14, characterized in that, The copolymer polypropylene is a random copolymer or block copolymer of terminal olefins / cyclic olefins and propylene, wherein the terminal olefins / cyclic olefins are selected from at least one of ethylene, C4-C8 α-olefins, vinylcyclohexane, vinylcyclohexene and norbornene.

19. The polypropylene composition according to claim 14, characterized in that, The polypropylene is selected from at least one of homopolymer polypropylene, random copolymer of propylene and ethylene, and block copolymer of propylene and ethylene.

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