Polypropylene nucleating agent composition and application thereof

Abstract

The invention relates to a polypropylene nucleating agent composition and application thereof, the polypropylene nucleating agent composition is formed by mixing p-tert-butylbenzoic acid monohydroxy aluminum and p-tert-butylbenzoic acid metal salt, the mass percentage of p-tert-butylbenzoic acid monohydroxy aluminum accounts for 10-50% of the total mass percentage of the polypropylene nucleating agent composition, and the mass percentage of p-tert-butylbenzoic acid metal salt accounts for 10-50% of the total mass percentage of the polypropylene nucleating agent composition. The p-tert-butylbenzoic acid metal salt accounts for 50-90% of the total mass of the polypropylene nucleating agent composition. The invention also comprises the application of the polypropylene nucleating agent composition, and the components of the polypropylene nucleating agent composition are directly mixed and then added into polypropylene. The polypropylene nucleating agent provided by the invention has the advantages of small addition amount, good nucleating effect, improved mechanical properties and the like, and can be used after being directly mixed with other p-tert-butylbenzoic acid metal salts, so that the cost can be reduced, and the crystallization temperature and rigidity of polypropylene can be remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of materials technology and relates to a polypropylene nucleating agent composition and its application, specifically to a polypropylene nucleating agent composed of aluminum monohydroxyl of p-tert-butylbenzoic acid and other p-tert-butyl metal salts and its application. Background Technology

[0002] Polypropylene, as one of the five major general-purpose plastics, boasts the fastest development among them. It possesses excellent properties such as lightweight, corrosion resistance, high temperature resistance, and superior mechanical properties, making it widely used in various fields. However, it also suffers from drawbacks such as poor weather resistance, significant low-temperature brittleness, high shrinkage, and insufficient transparency, greatly limiting its application range. Therefore, modification is crucial. Currently, the most common method for polypropylene modification is the direct addition of nucleating agents, which is widely used in polypropylene processing. Nucleating agents provide heterogeneous nucleation sites for polypropylene melt crystallization, significantly increasing the crystallization temperature, accelerating the crystallization rate, and refining the spherulite size. This effectively shortens the injection molding cycle, improves production efficiency, and enhances the transparency, rigidity, toughness, and surface gloss of the finished product. However, the performance improvements and advantages / disadvantages of each nucleating agent differ. For example, inorganic nucleating agents are relatively inexpensive and can increase the crystallization rate and improve the physical properties of polypropylene, but they have poor compatibility with polypropylene. Phosphate esters and dicycloheptanate salts, for instance, have high physical properties but are expensive. Therefore, it is difficult to achieve the desired effect of improving the various properties of polypropylene in a balanced way using a single nucleating agent.

[0003] CN 101418083 B discloses a polypropylene nucleating agent and its preparation method. Although it has achieved good results, its raw material tetraisopropyl titanate has a high cost and its preparation method is relatively complicated. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a polypropylene nucleating agent composition and its application. Applying the polypropylene nucleating agent composition to polypropylene can significantly improve the crystallization temperature, flexural properties and tensile strength of polypropylene, and at a lower cost.

[0005] The technical solution adopted by the present invention to solve its technical problem is that the polypropylene nucleating agent composition of the present invention is composed of aluminum monohydroxyp-tert-butylbenzoic acid and a metal salt of p-tert-butylbenzoic acid.

[0006] Furthermore, by weight percentage, aluminum monohydroxy p-tert-butylbenzoate accounts for 10-50% of the total mass percentage of the polypropylene nucleating agent composition, and the metal salt of p-tert-butylbenzoate accounts for 50-90% of the total mass percentage of the polypropylene nucleating agent composition.

[0007] Adding too much or too little aluminum monohydroxy tert-butylbenzoate will affect the performance of polypropylene.

[0008] Furthermore, the metal salt of p-tert-butylbenzoic acid is at least one of sodium p-tert-butylbenzoate and potassium p-tert-butylbenzoate.

[0009] The structural formula of aluminum monohydroxyl group of p-tert-butylbenzoic acid is: .

[0010] Further, the preparation method of aluminum monohydroxyl of p-tert-butylbenzoic acid is as follows: p-tert-butylbenzoic acid is added to sodium hydroxide solution, and the mixture is stirred and neutralized at room temperature for 30-60 minutes. After the neutralization reaction is completed, aluminum chloride solution is added to the reaction system, and the reaction is stopped after a displacement / hydroxylation reaction is carried out at 40-60℃ for 1-1.5 hours. The reaction product is then filtered, dried, and ground into powder to obtain the final product.

[0011] Furthermore, in the preparation method of aluminum monohydroxyl of p-tert-butylbenzoic acid, the molar ratio of p-tert-butylbenzoic acid to sodium hydroxide contained in the sodium hydroxide solution is 1:1.

[0012] Furthermore, in the preparation method of aluminum monohydroxyl of p-tert-butylbenzoic acid, the molar ratio of p-tert-butylbenzoic acid to aluminum chloride contained in the aluminum chloride solution is 2:1.

[0013] Furthermore, in the method for preparing aluminum monohydroxylate tert-butylbenzoic acid, the mass concentration of the aluminum chloride solution is 20-40% (more preferably 30%).

[0014] Furthermore, the preparation method of sodium p-tert-butylbenzoate is as follows: p-tert-butylbenzoic acid is added to sodium hydroxide solution, stirred and neutralized at room temperature for 30-60 minutes, filtered, dried, and ground into powder to obtain the product.

[0015] Furthermore, in the preparation method of sodium p-tert-butylbenzoate, the molar ratio of p-tert-butylbenzoic acid to sodium hydroxide contained in the sodium hydroxide solution is 1:1.

[0016] Furthermore, the preparation method of potassium p-tert-butylbenzoate is as follows: p-tert-butylbenzoic acid is added to potassium hydroxide solution, stirred and neutralized at room temperature for 30-60 minutes, filtered, dried, and ground into powder to obtain the product.

[0017] Furthermore, in the preparation method of potassium p-tert-butylbenzoate, the molar ratio of p-tert-butylbenzoic acid to potassium hydroxide contained in the potassium hydroxide solution is 1:1.

[0018] Furthermore, in the preparation methods of aluminum monohydroxyl p-tert-butylbenzoate and sodium p-tert-butylbenzoate, the mass concentration of sodium hydroxide solution is 10-50% (more preferably 20%).

[0019] Furthermore, in the method for preparing potassium tert-butylbenzoate, the mass concentration of the potassium hydroxide solution is 10-50% (more preferably 20%).

[0020] The application of the polypropylene nucleating agent composition of the present invention involves directly mixing the components of the polypropylene nucleating agent composition and then adding it to polypropylene. The amount of polypropylene nucleating agent composition added is equivalent to 0.05% to 1% of the mass of polypropylene. The optimal addition amount is 0.1% to 0.3%.

[0021] The beneficial effects of this invention are: The polypropylene nucleating agent of the present invention, which is a composite of aluminum monohydroxyl p-tert-butylbenzoic acid and other metal salts of p-tert-butylbenzoic acid, is a highly efficient additive with advantages such as low addition amount, good nucleation effect, and improved mechanical properties. Aluminum monohydroxyl p-tert-butylbenzoic acid can be used by directly mixing with other metal salts of p-tert-butylbenzoic acid, which can not only reduce costs, but also significantly improve the crystallization temperature and rigidity of polypropylene.

[0022] Studies have shown that the organic nucleating agent aluminum monohydroxyl p-tert-butylbenzoate (Al-PTBBA) can effectively improve the rigidity and surface hardness of polypropylene and significantly increase the crystallization temperature. Combining Al-PTBBA, which exhibits good rigidity, with other inexpensive metal salt nucleating agents of p-tert-butylbenzoate can significantly improve the crystallization temperature, flexural modulus, and tensile strength, resulting in a low-cost, highly effective nucleation agent that significantly improves the properties of polypropylene. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] 1. Raw materials: Aluminum monohydroxylamine (Al-PTBBA): Add p-tert-butylbenzoic acid to a 20% sodium hydroxide solution (molar ratio of p-tert-butylbenzoic acid to sodium hydroxide is 1:1), stir and neutralize at room temperature for 30-60 minutes. After the neutralization reaction is completed, add a 30% aluminum chloride solution (molar ratio of p-tert-butylbenzoic acid to aluminum chloride is 2:1) to the reaction system, and carry out a displacement / hydroxylation reaction at 40-60℃ for 1-1.5 hours to stop the reaction. Filter, dry, and grind the reaction product to obtain the final product.

[0025] Sodium p-tert-butylbenzoate (Na-PTBBA): Add p-tert-butylbenzoic acid to a 20% sodium hydroxide solution (the molar ratio of p-tert-butylbenzoic acid to sodium hydroxide is 1:1), stir and neutralize at room temperature for 30-60 minutes, then filter, dry, and grind to obtain the product.

[0026] Potassium p-tert-butylbenzoate (K-PTBBA): Add p-tert-butylbenzoic acid to a 20% potassium hydroxide solution (the molar ratio of p-tert-butylbenzoic acid to potassium hydroxide is 1:1), stir and neutralize at room temperature for 30-60 minutes, then filter, dry, and grind to obtain the product.

[0027] Polypropylene, Maoming Shihua Dongcheng Chemical Co., Ltd.

[0028] Antioxidant 1010, 168, from Cherbat Specialty Chemicals, Switzerland.

[0029] 2. Instruments and equipment 2.1 SHR~100 High-Speed ​​Mixer, Zhangjiagang Light Machinery Factory 2.2 SHJ~20B twin-screw extruder, Nanjing J&T Electromechanical Co., Ltd. Table 1 Extrusion temperature (°C): ; 2.3 WZS Experimental Miniature Injection Molding Machine, Shanghai Xinshuo Precision Machinery Co., Ltd. 2.4 WDT~W~60B1 Micro-controlled Electronic Universal Testing Machine, Chengde Precision Testing Machine Co., Ltd.

[0030] 3. Examples

[0031] Example 1 250g of polypropylene, 0.75g of a polypropylene nucleating agent composition (aluminum monohydroxyl p-tert-butylbenzoate and sodium p-tert-butylbenzoate in a mass ratio of 1:1), and 0.25g of antioxidants (1010 and 168) were uniformly mixed in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0032] Example 2 250g of polypropylene, 0.75g of a polypropylene nucleating agent composition (aluminum monohydroxyl p-tert-butylbenzoate and sodium p-tert-butylbenzoate in a mass ratio of 1:2), and 0.25g of antioxidants (1010 and 168) were uniformly mixed in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0033] Example 3 250g of polypropylene, 0.75g of a polypropylene nucleating agent composition (aluminum monohydroxyl p-tert-butylbenzoate and sodium p-tert-butylbenzoate in a mass ratio of 1:3), and 0.25g of antioxidants (1010 and 168) were uniformly mixed in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0034] Example 4 250g of polypropylene, 0.75g of a polypropylene nucleating agent composition (aluminum monohydroxyl p-tert-butylbenzoate and sodium p-tert-butylbenzoate in a mass ratio of 1:9), and 0.25g of antioxidants (1010 and 168) were uniformly mixed in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0035] Example 5 250g of polypropylene, 0.75g of a polypropylene nucleating agent composition (aluminum monohydroxyl p-tert-butylbenzoate and potassium p-tert-butylbenzoate in a mass ratio of 1:1), and 0.25g of antioxidants (1010 and 168) were uniformly mixed in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0036] Example 6 250g of polypropylene, 0.75g of a polypropylene nucleating agent composition (aluminum monohydroxyl p-tert-butylbenzoate and potassium p-tert-butylbenzoate in a mass ratio of 1:2), and 0.25g of antioxidants (1010 and 168) were uniformly mixed in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0037] Example 7 250g of polypropylene, 0.75g of polypropylene nucleating agent composition (aluminum monohydroxyl p-tert-butylbenzoate and potassium p-tert-butylbenzoate in a mass ratio of 1:3), and 0.25g of antioxidants (1010 and 168) were uniformly mixed in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0038] Example 8 250g of polypropylene, 0.75g of a polypropylene nucleating agent composition (aluminum monohydroxyl p-tert-butylbenzoate and potassium p-tert-butylbenzoate in a mass ratio of 1:9), and 0.25g of antioxidants (1010 and 168) were uniformly mixed in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0039] Comparative Example 1 Mix 250g of polypropylene and 0.25g of antioxidants (1010 and 168) evenly in a high-speed mixer for 3-8 minutes to obtain a mixture. Then, extrude the mixture into granules using a twin-screw extruder at an extrusion temperature of 200-220℃, and finally injection mold the granules to produce polypropylene standard sample strips.

[0040] Comparative Example 2 250g of polypropylene, 0.75g of aluminum monohydroxyl p-tert-butylbenzoate, and 0.25g of antioxidants (1010 and 168) were mixed uniformly in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0041] Comparative Example 3 250g of polypropylene, 0.75g of sodium p-tert-butylbenzoate, and 0.25g of antioxidants (1010 and 168) were mixed evenly in a high-speed mixer for 3-8 minutes to obtain a mixture. The mixture was then fed into a twin-screw extruder for granulation at an extrusion temperature of 200-220℃, and then injection molded to produce polypropylene standard sample strips.

[0042] Comparative Example 4 Mix 250g of polypropylene, 0.75g of potassium p-tert-butylbenzoate, and 0.25g of antioxidants (1010 and 168) uniformly in a high-speed mixer for 3-8 minutes to obtain a mixture. Then, extrude the mixture into a twin-screw extruder at an extrusion temperature of 200-220℃, and finally injection mold it to produce polypropylene standard sample strips.

[0043] Physical performance testing Differential Scanning Calorimetry (DSC) Analysis Crystallization temperature T C Measurements were performed. 4 mg samples from each example and comparative example were weighed and placed in an aluminum crucible. Under nitrogen protection, the temperature was increased to 190 °C at a heating rate of 40 °C / min, held at this temperature for 5 min to eliminate thermal history, and then cooled from 190 °C to 100 °C at a cooling rate of 10 °C / min to obtain the crystallization curve. The temperature was then increased from 100 °C to 190 °C at a heating rate of 10 °C / min to obtain the melting curve.

[0044] Mechanical property testing The standard sample strips after injection molding were left to stand for 48 hours before testing. Physical property tests were conducted according to national standards: flexural modulus was performed according to standard GB / T 9341-2008, and tensile strength was performed according to standard GB / T 1040-2025.

[0045] This invention compares and tests the changes in the physical properties of polypropylene before and after modification using a polypropylene nucleating agent composed of aluminum monohydroxyl of p-tert-butylbenzoic acid and other metal salts of p-tert-butylbenzoic acid, such as the crystallization temperature T. C The flexural modulus and tensile strength were tested, and the results are shown in Tables 2 and 3. Table 2 shows the crystallization temperature, flexural modulus, and tensile strength of polypropylene with different proportions of aluminum monohydroxyl p-tert-butylbenzoate and sodium p-tert-butylbenzoate; Table 3 shows the crystallization temperature, flexural modulus, and tensile strength of polypropylene with different proportions of aluminum monohydroxyl p-tert-butylbenzoate and potassium p-tert-butylbenzoate.

[0046] Based on the test results, the function of the composite nucleating agent was comprehensively evaluated, and the evaluation results are as follows: Table 2. Test results of crystallization temperature, flexural modulus, and tensile strength of polypropylene with different proportions of aluminum monohydroxyl p-tert-butylbenzoate and sodium p-tert-butylbenzoate. ; Table 3. Crystallization temperature, flexural modulus, and tensile strength test results of polypropylene with different proportions of aluminum monohydroxyl p-tert-butylbenzoate and potassium p-tert-butylbenzoate. ; Table 2 shows that the composite nucleating agent of aluminum tert-butylbenzoate and sodium tert-butylbenzoate significantly improved the crystallization temperature, flexural modulus, and tensile modulus of polypropylene under the three composite ratios. In particular, when the composite ratio of aluminum tert-butylbenzoate to sodium tert-butylbenzoate was 1:2 (Example 2), the modified polypropylene showed a 9.9°C increase in crystallization temperature, a 113.2% increase in flexural modulus, and a 16.3% increase in tensile strength compared to Comparative Example 1. Compared to Comparative Examples 2 and 3, the flexural modulus and tensile modulus were also improved, achieving the best results. The crystallization temperatures of Examples 1, 2, 3, and 4 were slightly lower than those of Comparative Example 3, possibly because aluminum tert-butylbenzoate and sodium tert-butylbenzoate compete for nucleation, causing the crystallization temperature to shift towards the sodium tert-butylbenzoate method.

[0047] Table 3 shows that the composite nucleating agent of aluminum monohydroxyl p-tert-butylbenzoate and potassium p-tert-butylbenzoate significantly improves the crystallization temperature, flexural modulus, and tensile strength of polypropylene under all three composite ratios. When the composite ratio of aluminum monohydroxyl p-tert-butylbenzoate and potassium p-tert-butylbenzoate is 1:3, i.e., Example 7, the modified polypropylene shows a 7.0°C increase in crystallization temperature, a 93.8% increase in flexural modulus, and a 12.8% increase in tensile strength compared to Comparative Example 1. The comparative analysis results demonstrate that the composite effect of aluminum monohydroxyl p-tert-butylbenzoate with sodium p-tert-butylbenzoate or potassium p-tert-butylbenzoate is excellent, making it a highly effective nucleating agent for polypropylene modification.

[0048] The polypropylene nucleating agent of the present invention, which is a composite of aluminum monohydroxyl p-tert-butylbenzoic acid and other metal salts of p-tert-butylbenzoic acid, is a highly efficient additive with the advantages of low addition amount, good nucleation effect, and improved mechanical properties. It can not only reduce costs, but also significantly improve the crystallization temperature and rigidity of polypropylene.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A polypropylene nucleating agent composition characterized in that, The p-tert-butyl benzoic acid monohydroxy aluminum is mixed with the p-tert-butyl benzoic acid metal salt.

2. The polypropylene nucleator composition of claim 1, wherein, The p-tert-butyl benzoic acid monohydroxy aluminum accounts for 10-50% of the total mass percentage of the polypropylene nucleating agent composition, and the p-tert-butyl benzoic acid metal salt accounts for 50-90% of the total mass percentage of the polypropylene nucleating agent composition.

3. The polypropylene nucleator composition according to claim 1 or 2, characterized in that, The p-tert-butyl benzoic acid metal salt is at least one of sodium p-tert-butyl benzoate and potassium p-tert-butyl benzoate.

4. The polypropylene nucleator composition according to claim 1 or 2, wherein The preparation method of the p-tert-butyl benzoic acid monohydroxy aluminum is as follows: p-tert-butyl benzoic acid is added to a sodium hydroxide solution, stirred at room temperature, and neutralized for 30-60 minutes; after the neutralization reaction is completed, an aluminum chloride solution is added to the reaction system, and the displacement / hydroxylation reaction is carried out at 40-60°C for 1-1.5 hours to end the reaction; and the reaction product is filtered, dried, and ground to obtain the product.

5. The polypropylene nucleator composition of claim 4, wherein the polypropylene is a propylene homopolymer. In the preparation method of the p-tert-butyl benzoic acid monohydroxy aluminum, the molar ratio of p-tert-butyl benzoic acid to sodium hydroxide contained in the sodium hydroxide solution is 1:1; and / or in the preparation method of the p-tert-butyl benzoic acid monohydroxy aluminum, the molar ratio of p-tert-butyl benzoic acid to aluminum chloride contained in the aluminum chloride solution is 2:1; and / or in the preparation method of the p-tert-butyl benzoic acid monohydroxy aluminum, the mass concentration of the aluminum chloride solution is 20-40%.

6. The polypropylene nucleator composition of claim 3, wherein, The preparation method of the sodium p-tert-butyl benzoate is as follows: p-tert-butyl benzoic acid is added to a sodium hydroxide solution, stirred at room temperature, and neutralized for 30-60 minutes; and the product is obtained after filtration, drying, and grinding; and / or the preparation method of the potassium p-tert-butyl benzoate is as follows: p-tert-butyl benzoic acid is added to a potassium hydroxide solution, stirred at room temperature, and neutralized for 30-60 minutes; and the product is obtained after filtration, drying, and grinding.

7. The polypropylene nucleator composition of claim 6, wherein, In the preparation method of the sodium p-tert-butyl benzoate, the molar ratio of p-tert-butyl benzoic acid to sodium hydroxide contained in the sodium hydroxide solution is 1:1; and / or in the preparation method of the potassium p-tert-butyl benzoate, the molar ratio of p-tert-butyl benzoic acid to potassium hydroxide contained in the potassium hydroxide solution is 1:

1.

8. The polypropylene nucleator composition according to claim 4 or 6, wherein In the preparation method of the p-tert-butyl benzoic acid monohydroxy aluminum and the sodium p-tert-butyl benzoate, the mass concentration of the sodium hydroxide solution is 10-50%; and / or in the preparation method of the potassium p-tert-butyl benzoate, the mass concentration of the potassium hydroxide solution is 10-50%.

9. Use of a polypropylene nucleator composition according to one of claims 1 to 8, characterized in that, The components of the polypropylene nucleating agent composition are directly mixed and then added to polypropylene, and the addition amount of the polypropylene nucleating agent composition is 0.05%-1% of the mass of the polypropylene.

10. The use of a polypropylene nucleator composition according to claim 9, characterized in that The addition amount of the polypropylene nucleating agent composition is 0.1-0.3% of the mass of the polypropylene.