Synthesis and application of improved bioring carboxylate nucleating agent

Abstract

This invention provides the synthesis and application of an improved bicyclic carboxylate nucleating agent, relating to the field of nucleating agent synthesis technology. The synthesis of this improved bicyclic carboxylate nucleating agent involves adding 4,5-epoxytetrahydrophthalic acid diglycidyl ester to a diluent, adding an emulsifier, and stirring for 10-20 minutes. Norbornene adienoic anhydride is then added, and the temperature is raised to 50-60°C, reacting for 1-2 hours. A 45% sodium hydroxide solution is then added dropwise, and the temperature is maintained at 50-60°C for another 1-2 hours to obtain the improved bicyclic carboxylate nucleating agent. Its preparation method is simple, with low raw material costs, good compatibility with polypropylene, low migration, and good nucleation effect. The resulting polypropylene exhibits low shrinkage, high flexural modulus, and high transparency. It solves the problems of poor dispersibility and compatibility, and complex synthesis steps caused by the polar forces of bicyclic carboxylate nucleating agents, making it particularly suitable for thin-walled injection-molded polypropylene products.

Description

Technical Field

[0001] This invention relates to the field of nucleating agent synthesis technology, specifically to the synthesis and application of an improved bicyclic carboxylate nucleating agent. Background Technology

[0002] Bicyclic carboxylate nucleating agents are a class of nucleating agents with high nucleating efficiency, high PP crystallization temperature, and short crystallization half-life. They are particularly advantageous in terms of the isostatic properties of the molded polymer, making them excellent nucleating agents for polymers with special requirements. As a representative product of bicyclic carboxylate nucleating agents, Milliken's HPN-68 is still used in polypropylene. However, because bicyclic carboxylate nucleating agents are prepared in an aqueous phase and discharged after dehydration and drying, their polar forces can easily lead to agglomeration, affecting their dispersibility and compatibility in PP. Therefore, the effectiveness of HPN-68 is limited. According to the author's understanding, Milliken has also made improvements to the performance of HPN-68 nucleating agent.

[0003] In 2004, Milliken published a patent titled "A Novel Nucleating Agent for Thermoplastics with Many Uses" (Publication No.: CN1511134A). This patent provided a detailed report on the effects of carboxylate nucleating agents of different metal ions on the properties of homopolymer PP, confirming that sodium and calcium salts can increase the crystallization temperature of homopolymer PP, reduce PP turbidity, and shorten the crystallization half-cycle. The drawbacks are that the reduction in haze is limited, and the impact on mechanical properties needs further investigation. In 2006, Milliken Corporation published a patent titled "Improved Bicyclic [2.2.1]Heptane Dicarboxylate Nucleating Additive Formulation" (Publication No.: CN 1863857A). This patent reported the production of a fine-particle-size, well-dispersed nucleating agent by adding an anti-caking agent, SYLOBLOCM250, to the nucleating agent HPN-68, using air jet milling. This reduces the haze of polypropylene, achieving transparency. However, the air jet milling process is relatively cumbersome. In 2007, Milliken Corporation published a patent titled "Saturated Dicyclic Dicarboxylate Concentrate Polymer Nucleating Additive and Method for Nucleating Thermoplastic Plastics" (Publication No. CN 1894322 A). This patent involves adding the nucleating agent HPN-68, along with dispersants (such as calcium carbonate) or other additives like pigments, to the resin at a high concentration to create a nucleating agent masterbatch. Due to the high dosage, this form is not suitable for large-scale production of polypropylene. In 2007, Milliken Corporation published a patent titled "Thermoplastic Polymer Composition Containing Two Nucleating Agents" (Publication No. CN101065434A). This patent reported that by compounding a carboxylate nucleating agent with a phosphate nucleating agent in a certain proportion, good material properties and high nucleation efficiency were achieved. The advantage of this method is its simplicity and good results. The disadvantage is the high cost of purchasing other types of nucleating agents. In 2009, Milliken Corporation published a patent titled "Metal Carboxylate Nucleating or Clarifying Compounds and Related Polymer Compositions and Methods" (Publication No. CN 101395129A). This patent utilizes carboxylate compounds combining amide groups and metal cation salts to significantly reduce resin haze. The patent redesigns the HPN-68 nucleating agent synthesis steps, modifying the chemical structure to obtain a more efficient nucleating agent. This addresses the problems of poor dispersibility, high haze, and low mechanical properties inherent in existing nucleating agents at the molecular structure level. This method promotes the addition of weakly polar groups to the compound, thereby improving the compound's dispersion in polyolefins and providing a good approach to improving the performance of this type of nucleating agent. However, the synthesis of the raw material used in this invention, bicyclic [2.2.1]heptane dicarboxylic anhydride, requires acetic anhydride for ring closure, resulting in a complex process route and excessively high industrialization costs.

[0004] Currently, domestic research on this type of nucleating agent mainly focuses on improving yield and product concentration. In 2015, Shi Jiangong et al. published "A method for preparing disodium dicyclo[2.2.1]heptane-2,3-dicarboxylate" (publication number CN102952010B). The yield of the product reported in this paper reached over 98%, but there was no improvement in performance.

[0005] Therefore, this invention has developed a new improved bicyclic carboxylate nucleating agent and its application. Summary of the Invention

[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides an improved synthesis and application of bicyclic carboxylate nucleating agents, which solves the problem that existing domestic research on bicyclic carboxylate nucleating agents mainly focuses on improving yield and product concentration, but without improving performance.

[0007] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: an improved bicyclic carboxylate nucleating agent, wherein the structural formula of the nucleating agent is as follows: .

[0008] This invention also provides a method for synthesizing an improved bicyclic carboxylate nucleating agent, comprising the following steps: S1: Add 4,5-epoxytetrahydrophthalic acid diglycidyl ester to the diluent, heat to 45-55℃, add the emulsifier, and stir for 10-20 minutes. S2: Add norborneol enediic anhydride, heat to 50-60℃, and react for 1-2 hours; S3: Add 45% sodium hydroxide solution dropwise, keep warm at 50-60℃, react for 1-2 hours, distill under reduced pressure, grind, and obtain the improved bicyclic carboxylate nucleating agent.

[0009] Optionally, the diluent in step S1 is any one of benzene, toluene, carbon tetrachloride, chloroform, ethanol, and ethyl acetate.

[0010] Optionally, the emulsifier in step S1 is any one of sodium dodecyl sulfate, calcium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide, and dodecylphenol polyoxyethylene ether.

[0011] Optionally, the concentration of 4,5-epoxytetrahydrophthalic acid diglycidyl ester in the diluent in step S1 is 50%-60%.

[0012] Optionally, the amount of emulsifier used in step S1 is 0.5-1.5% of the mass of diglycidyl 4,5-epoxytetrahydrophthalic acid.

[0013] Optionally, the molar ratio of norbornene and 4,5-epoxytetrahydrophthalic acid diglycidyl ester in step S2 is 3:1.

[0014] Optionally, the molar ratio of sodium hydroxide to norborneol olefinic anhydride in step S3 is 1:1.

[0015] When the above-mentioned improved bicyclic carboxylate is used in the melt extrusion of polypropylene resin, take 0.1 parts by weight of the above-mentioned nucleating agent, 100 parts of polypropylene (grade MM90 powder), 0.1 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, 0.1 parts by weight of calcium stearate, and 0.1 parts by weight of monoglyceride. After mixing them in a high-speed mixer, they are extruded by a twin-screw extruder at a processing temperature of 230°C. Then, they are injection molded into sample strips by an injection molding machine.

[0016] (III) Beneficial Effects This invention provides the synthesis and application of an improved bicyclic carboxylate nucleating agent. It possesses the following beneficial effects: The synthesis and application of this improved bicyclic carboxylate nucleating agent involves adding 4,5-epoxytetrahydrophthalic acid diglycidyl ester to a diluent and an emulsifier, stirring for 10-20 minutes. Norbornene adienoic anhydride is then added, and the mixture is heated to 50-60°C and reacted for 1-2 hours. A 45% sodium hydroxide solution is then added dropwise, and the mixture is kept at 50-60°C for another 1-2 hours to obtain the improved bicyclic carboxylate nucleating agent. This method is simple, uses low-cost raw materials, exhibits good compatibility with polypropylene, low migration, and good nucleation effect. The resulting polypropylene has low shrinkage, high flexural modulus, and high transparency. It solves the problems of poor dispersibility and compatibility, and complex synthesis steps caused by the polar forces of bicyclic carboxylate nucleating agents, making it particularly suitable for thin-walled polypropylene injection molded products. Attached Figure Description

[0017] Figure 1 This is the structural formula of the nucleating agent of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1 This embodiment provides a method for synthesizing an improved bicyclic carboxylate nucleating agent, comprising the following steps: (1) Take 60g of 4,5-epoxytetrahydrophthalic acid diglycidyl ester and add it to 60g of toluene diluent. Stir and gradually heat to 45℃. Then add 0.3g of cetyltrimethylammonium bromide and keep warm at 45℃ while stirring for 20min.

[0020] (2) Take 99g of norborneol edane and heat it to 60℃ for 1h.

[0021] (3) Take 220g of sodium hydroxide solution and add it dropwise to the above reactants. Keep the temperature at 60℃ and react for 1h. Then, evaporate by rotary evaporation and grind to obtain a white solid nucleating agent.

[0022] (4) Take 100 parts of polypropylene (grade MM90 powder), 0.1 parts of the above nucleating agent, 0.1 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.1 parts of calcium stearate, and 0.1 parts of monoglyceride. Mix them in a high-speed mixer and then extrude them by twin-screw extruder at a processing temperature of 230°C. Then, inject them into the sample strips using an injection molding machine.

[0023] The flexural modulus of the prepared modified polypropylene was determined according to the national standard GB / T 9341-2008, as shown in Table 1.

[0024] The transmittance and haze of the prepared modified polypropylene were measured according to the national standard GB / T 2410-2008, as shown in Table 1.

[0025] Example 2 This embodiment provides a method for synthesizing an improved bicyclic carboxylate nucleating agent, comprising the following steps: (1) Take 60g of 4,5-epoxytetrahydrophthalic acid diglycidyl ester and add it to 60g of benzene diluent. Stir and gradually heat to 45℃. Then add 0.3g of calcium dodecylbenzenesulfonate and keep warm at 45℃ while stirring for 20min.

[0026] (2) Take 99g of norborneol edane and heat it to 60℃ for 1h.

[0027] (3) Take 220g of sodium hydroxide solution and add it dropwise to the above reactants. Keep the temperature at 60℃ and react for 1h. Then, evaporate by rotary evaporation and grind to obtain a white solid nucleating agent.

[0028] (4) Take 100 parts of polypropylene (grade MM90 powder), 0.1 parts of the above nucleating agent, 0.1 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.1 parts of calcium stearate, and 0.1 parts of monoglyceride. Mix them in a high-speed mixer and then extrude them by twin-screw extruder at a processing temperature of 230°C. Then, inject them into the sample strips using an injection molding machine.

[0029] Following the same method as in Example 1, the flexural modulus, light transmittance, and haze of the prepared modified polypropylene material were measured, and the results are shown in Table 1.

[0030] Example 3 This embodiment provides a method for synthesizing an improved bicyclic carboxylate nucleating agent, comprising the following steps: (1) Take 60g of 4,5-epoxytetrahydrophthalic acid diglycidyl ester and add it to 60g of ethyl acetate diluent. Stir and gradually heat to 45℃. Then add 0.3g of dodecylphenol polyoxyethylene ether and keep warm at 45℃ for 20min.

[0031] (2) Take 99g of norborneol edane and heat it to 60℃ for 1h.

[0032] (3) Take 220g of sodium hydroxide solution and add it dropwise to the above reactants. Keep the temperature at 60℃ and react for 1h. Then, evaporate by rotary evaporation and grind to obtain a white solid nucleating agent.

[0033] (4) Take 100 parts of polypropylene (grade MM90 powder), 0.1 parts of the above nucleating agent, 0.1 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.1 parts of calcium stearate, and 0.1 parts of monoglyceride. Mix them in a high-speed mixer and then extrude them by twin-screw extruder at a processing temperature of 230°C. Then, inject them into the sample strips using an injection molding machine.

[0034] Following the same method as in Example 1, the flexural modulus, light transmittance, and haze of the prepared modified polypropylene material were measured, and the results are shown in Table 1.

[0035] Comparative Example This comparative example provides a method for synthesizing an improved bicyclic carboxylate nucleating agent, comprising the following steps: Take 100 parts of polypropylene (grade MM90 powder), 0.1 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, 0.1 parts by weight of calcium stearate, and 0.1 parts by weight of monoglyceride. Mix them in a high-speed mixer and then extrude them by a twin-screw extruder at a processing temperature of 230°C. Then, injection mold them into sample strips using an injection molding machine.

[0036] Table 1. Test results of polypropylene materials As can be seen from Table 1, the modified polypropylene obtained using the embodiments of the present invention has significantly increased flexural modulus and light transmittance, and reduced haze compared with the raw material MM90 powder.

[0037] Among them: (1) Bending modulus (also known as Young's modulus or elastic modulus under bending conditions) is an indicator that measures a material's ability to resist bending deformation. It reflects the degree of "stiffness" or "hardness" of a material when it is bent under stress.

[0038] The significant increase in flexural modulus means that the modified polypropylene becomes more "stiff" and "rigid." Under the same bending force, it produces less bending deformation. In other words, it is less likely to bend or collapse and is better able to maintain its shape. This is crucial for applications requiring high structural support and dimensional stability, such as automotive parts, appliance housings, and certain engineering structural components.

[0039] (2) Light transmittance refers to the ability of light to pass through a material, usually expressed as a percentage. It measures how much incident light can directly penetrate the material.

[0040] The significant increase in light transmittance means that the modified polypropylene has become more "transparent." More light can pass through it, making objects appear clearer when viewed through the material. This typically means fewer scattering points inside or on the surface of the material. This is highly advantageous for applications requiring high transparency, such as transparent containers, optics, display components, and medical devices.

[0041] (3) Haze refers to the proportion of light rays that deviate from straight-line propagation (scattering) in the light passing through a material. The higher the haze, the more "turbid" or "hazy" the material looks, and the less clear it is to see things through it.

[0042] Reduced haze means that the modified polypropylene becomes clearer and more transparent. Light is scattered less as it passes through the material, and more light travels in straight lines. This directly improves the material's visual clarity. Reduced haze is usually accompanied by increased light transmittance, both reflecting a more uniform and regular internal structure of the material. This is crucial for applications requiring high optical quality, such as packaging materials, optical films, and lamp covers.

[0043] In summary, modified polypropylene retains its original advantages while becoming more rigid (less prone to deformation), transparent (better light transmittance), and clearer (visually clearer). These improved properties greatly expand the application range of polypropylene, enabling it to meet the demands of applications requiring higher mechanical and optical properties.

[0044] In summary, this invention involves adding diglycidyl 4,5-epoxytetrahydrophthalic acid to a diluent and an emulsifier, stirring for 10-20 minutes, adding norbornene adienoic anhydride, heating to 50-60°C, and reacting for 1-2 hours. Then, a 45% sodium hydroxide solution is added dropwise, and the mixture is kept at 50-60°C for another 1-2 hours to obtain an improved bicyclic carboxylate nucleating agent. This method is simple, uses low-cost raw materials, exhibits good compatibility with polypropylene, low migration, and good nucleation effect. The resulting polypropylene has low shrinkage, high flexural modulus, and high transparency. It solves the problems of poor dispersibility and compatibility, and complex synthesis steps caused by the polarity of bicyclic carboxylate nucleating agents, making it particularly suitable for thin-walled polypropylene injection molded products.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An improved bicyclic carboxylate nucleating agent, characterized in that, The structural formula of the nucleating agent is as follows: .

2. The method for synthesizing an improved bicyclic carboxylate nucleating agent according to claim 1, characterized in that, Includes the following steps: S1: Add 4,5-epoxytetrahydrophthalic acid diglycidyl ester to the diluent, heat to 45-55℃, add the emulsifier, and stir for 10-20 minutes. S2: Add norborneol enediic anhydride, heat to 50-60℃, and react for 1-2 hours; S3: Add 45% sodium hydroxide solution dropwise, keep warm at 50-60℃, react for 1-2 hours, distill under reduced pressure, grind, and obtain the improved bicyclic carboxylate nucleating agent.

3. The method for synthesizing an improved bicyclic carboxylate nucleating agent according to claim 2, characterized in that: The diluent in step S1 is any one of benzene, toluene, carbon tetrachloride, chloroform, ethanol, and ethyl acetate.

4. The method for synthesizing an improved bicyclic carboxylate nucleating agent according to claim 3, characterized in that: The emulsifier in step S1 is any one of sodium dodecyl sulfate, calcium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, and dodecylphenol polyoxyethylene ether.

5. The method for synthesizing an improved bicyclic carboxylate nucleating agent according to claim 4, characterized in that: The concentration of 4,5-epoxytetrahydrophthalic acid diglycidyl ester in the diluent in step S1 is 50%-60%.

6. The method for synthesizing an improved bicyclic carboxylate nucleating agent according to claim 5, characterized in that: The amount of emulsifier used in step S1 is 0.5-1.5% of the mass of diglycidyl 4,5-epoxytetrahydrophthalic acid.

7. The method for synthesizing an improved bicyclic carboxylate nucleating agent according to claim 6, characterized in that: In step S2, the molar ratio of norbornene and diglycidyl 4,5-epoxytetrahydrophthalic acid is 3:

1.

8. The method for synthesizing an improved bicyclic carboxylate nucleating agent according to claim 7, characterized in that: In step S3, the molar ratio of sodium hydroxide to norborneol olefinic anhydride is 1:

1.

9. The application of the improved bicyclic carboxylate according to claim 1 in the melt extrusion of polypropylene resin.

10. The application according to claim 9, characterized in that: Take 0.1 parts by weight of the nucleating agent as described in claim 1, 100 parts of polypropylene (grade MM90 powder), 0.1 parts by weight of antioxidant 1010, 0.2 parts by weight of antioxidant 168, 0.1 parts by weight of calcium stearate, and 0.1 parts by weight of monoglyceride. Mix them in a high-speed mixer and then extrude them by a twin-screw extruder at a processing temperature of 230°C. Then, inject them into the sample strips using an injection molding machine.

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