A composite complexing agent for ultra-clean polypropylene and a preparation method and application thereof
By preparing a composite complexing agent containing carboxyl-containing organophosphonate monomers and bisβ-diketone derivatives, the problem of removing metal ash ions from polypropylene was solved, achieving a highly efficient and environmentally friendly deashing effect while ensuring that the performance of polypropylene is not affected.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTH HUAJIN CHEM IND CO LTD
- Filing Date
- 2026-04-09
- Publication Date
- 2026-07-10
AI Technical Summary
Existing technologies struggle to efficiently remove residual titanium, magnesium, and aluminum ash ions from polypropylene, leading to a decrease in the material's electrical insulation and transparency, thus limiting its application in high-end fields.
A composite complexing agent was prepared by using carboxyl-containing organophosphonate monomers and bisβ-diketone derivatives. The mixture was then mixed in hexane solvent via a phase transfer catalyst to form a synergistic complexing system, which was used for the deashing treatment of polypropylene powder.
It achieves efficient removal of metal ash ions such as titanium, magnesium, and aluminum, with residual amounts below 10 ppm, while maintaining the physical properties of polypropylene. The process is environmentally friendly and the solvent is easy to recycle.
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer material processing technology, specifically relating to a composite complexing agent for ultra-clean polypropylene and its preparation method, which is particularly suitable for ultra-clean treatment processes that remove metallic ash ions such as titanium, magnesium, and aluminum from polymerized polypropylene powder. Background Technology
[0002] Polypropylene (PP), as one of the world's largest-volume general-purpose plastics, is widely used in high-end fields such as electronics, food packaging, and medical devices. However, the traditional Ziegler-Natta catalyst polymerization process leaves residual metallic ash ions such as titanium (Ti), magnesium (Mg), and aluminum (Al) in polypropylene products (typically at a content of 50~200ppm), which significantly reduces the material's electrical insulation, aging resistance, and transparency, limiting its application in high-end fields.
[0003] Existing deashing technologies mainly include: Alcohol complexation method (e.g., CN118791651A): Polypropylene resin is washed and complexed using ethanol, hydrocarbons and complexing solvents, but there is a problem that solvent residue leads to a decrease in the thermal stability of polypropylene. Vapor phase deashing method (such as CN115260347A): The process is complex and requires large equipment investment.
[0004] Therefore, it is of great significance to develop a high-efficiency, environmentally friendly composite complexing agent that can deeply remove multiple metal ions. Summary of the Invention
[0005] (a) Technical problems to be solved This invention proposes a composite complexing agent for ultra-clean polypropylene, its preparation method, and its application, in order to solve the technical problem of how to achieve efficient removal of metal ash ions such as titanium, magnesium, and aluminum while ensuring that the physical properties of polypropylene are not affected.
[0006] (II) Technical Solution To address the aforementioned technical problems, this invention proposes a method for preparing a composite complexing agent for ultra-clean polypropylene, which includes the following steps: S1. Synthesize carboxyl-containing organophosphonate monomers; S2. Synthesize bisβ-diketone derivatives; S3. Preparation of composite complexing agent: Dissolve organophosphonate monomers and bisβ-diketone derivatives in hexane solvent, add phase transfer catalyst, and mix to obtain composite complexing agent.
[0007] Further, in step S1, the organophosphonate monomer is prepared by reacting triethyl phosphite with α-bromofatty acid.
[0008] Further, step S1 specifically includes: reacting triethyl phosphite and α-bromofatty acid in a molar ratio of 1:(2~3) at 120~140℃ for 4~6 hours to generate an organophosphonate monomer containing a carboxyl group.
[0009] Further, in step S2, the bisβ-diketone derivative is prepared by reacting acetylacetone with hydroquinone.
[0010] Further, step S2 specifically includes: reacting acetylacetone and hydroquinone at 80-100°C for 3-5 hours under concentrated sulfuric acid catalysis to generate a bis-β-diketone derivative.
[0011] Further, step S3 specifically includes: dissolving the organophosphonate monomer and the bisβ-diketone derivative in hexane solvent at a mass ratio of 3:(1~2), adding a phase transfer catalyst, and stirring and mixing at 50~60℃ for 2 hours to obtain a composite complexing agent.
[0012] Furthermore, in step S3, the phase transfer catalyst is tetrabutylammonium bromide (TBAB), and the amount added is 0.5~2 wt% of the material.
[0013] Furthermore, the present invention also proposes a composite complexing agent for ultra-clean polypropylene, which is prepared by the above method.
[0014] In addition, the present invention also proposes a polypropylene deashing treatment method, which involves using the above-mentioned ultra-clean polypropylene composite complexing agent to deash the polymerized polypropylene powder.
[0015] Furthermore, the polypropylene deashing treatment method specifically includes: mixing the polymerized polypropylene powder with a composite complexing agent at a solid-liquid ratio of 1:(5~10) at 80~90℃ for 1~2 hours, filtering, washing with hexane 3 times, and vacuum drying to obtain an ultra-clean polypropylene product.
[0016] (III) Beneficial Effects This invention proposes a composite complexing agent for ultra-clean polypropylene, its preparation method, and its application. The preparation method includes synthesizing a carboxyl-containing organophosphonate monomer; synthesizing a bisβ-diketone derivative; dissolving the organophosphonate monomer and the bisβ-diketone derivative in hexane solvent, adding a phase transfer catalyst, and mixing to obtain the composite complexing agent. This invention achieves efficient removal of metal ash ions such as titanium, magnesium, and aluminum through a synergistic complexing mechanism, while ensuring that the physical properties of polypropylene are not affected. The phosphonic acid groups in the carboxyl-containing organophosphonate monomer have a significant effect on the removal of titanium ash ions. 4+ Exhibiting strong chelating ability, the β-diketone structure in the bisβ-diketone derivative has a strong effect on Mg. 2+ Al 3+Exhibiting specific complexing properties, the two work synergistically to achieve highly efficient removal of multiple metal ions. In the phase transfer catalysis system, TBAB promotes the diffusion of the complexing agent within the polymer particles, significantly improving deashing efficiency (metal residue <10ppm). The hexane solvent system is compatible with polypropylene production processes, is easily recyclable, and leaves no residue, meeting green chemistry requirements. Detailed Implementation
[0017] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to examples.
[0018] This embodiment proposes a method for preparing a composite complexing agent for ultra-clean polypropylene, the preparation method including the following steps: S1. Synthesis of carboxyl-containing organophosphonate monomers 138g of triethyl phosphite and 160g of α-propionic acid were added to a reaction vessel and reacted at 130℃ for 5 hours. The fraction at 160~165℃ / 1.33 kPa was collected by vacuum distillation, with a yield of 85%.
[0019] S2. Synthesis of bisβ-diketone derivatives 100g of acetylacetone, 55g of hydroquinone and 5g of concentrated sulfuric acid were mixed and reacted at 90°C for 4 hours. After cooling, the mixture was filtered and recrystallized from ethanol to give a white solid with a yield of 78%.
[0020] S3. Preparation of Complexing Agents 7g of organophosphonate monomer and 25g of bisβ-diketone derivative were dissolved in 500mL of hexane solvent, and 5g of TBAB was added. The mixture was stirred at 55℃ for 2 hours to obtain a composite complexing agent.
[0021] S4. Deashing treatment Take 100g of polypropylene powder (Ti content 85ppm, Mg content 62ppm, Al content 45ppm), add 500mL of composite complexing agent solution, stir at 85℃ for 1.5 hours, filter, wash and dry.
[0022] Performance testing: Test Project Before processing After processing Removal rate Ti content (ppm) 35 3.2 90.9% Mg content (ppm) 62 4.8 92.3% Al content (ppm) 105 8.5 91.9% Melt index (g / 10min) 2.4 2.3 - Tensile strength (MPa) 32.5 32.8 +0.9% The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a composite complexing agent for ultra-clean polypropylene, characterized in that, The preparation method includes the following steps: S1. Synthesize carboxyl-containing organophosphonate monomers; S2. Synthesize bisβ-diketone derivatives; S3. Preparation of composite complexing agent: Dissolve organophosphonate monomers and bisβ-diketone derivatives in hexane solvent, add phase transfer catalyst, and mix to obtain composite complexing agent.
2. The method for preparing the composite complexing agent for ultra-clean polypropylene as described in claim 1, characterized in that, In step S1, the organophosphonate monomer is prepared by reacting triethyl phosphite with α-bromofatty acid.
3. The method for preparing the composite complexing agent for ultra-clean polypropylene as described in claim 2, characterized in that, Step S1 specifically includes: reacting triethyl phosphite and α-bromofatty acid in a molar ratio of 1:(2~3) at 120~140℃ for 4~6 hours to generate an organophosphonate monomer containing a carboxyl group.
4. The method for preparing the composite complexing agent for ultra-clean polypropylene as described in claim 1, characterized in that, In step S2, the bisβ-diketone derivative is prepared by reacting acetylacetone with hydroquinone.
5. The method for preparing the composite complexing agent for ultra-clean polypropylene as described in claim 4, characterized in that, Step S2 specifically includes: reacting acetylacetone and hydroquinone at 80-100°C for 3-5 hours under concentrated sulfuric acid catalysis to generate a bis-β-diketone derivative.
6. The method for preparing the composite complexing agent for ultra-clean polypropylene as described in claim 1, characterized in that, Step S3 specifically includes: dissolving organophosphonate monomers and bisβ-diketone derivatives in hexane solvent at a mass ratio of 3:(1~2), adding a phase transfer catalyst, and stirring and mixing at 50~60℃ for 2 hours to obtain a composite complexing agent.
7. The method for preparing the composite complexing agent for ultra-clean polypropylene as described in claim 6, characterized in that, In step S3, the phase transfer catalyst is tetrabutylammonium bromide (TBAB), and the amount added is 0.5~2 wt% of the material.
8. A composite complexing agent for ultra-clean polypropylene, characterized in that, The ultra-clean polypropylene composite complexing agent is prepared by the method described in any one of claims 1 to 7.
9. A method for deashing polypropylene, characterized in that, The polypropylene deashing treatment method involves using the ultra-clean polypropylene composite complexing agent described in claim 8 to deash the polymerized polypropylene powder.
10. The polypropylene deashing treatment method as described in claim 9, characterized in that, The specific method for deashing polypropylene includes: mixing the polymerized polypropylene powder with a composite complexing agent at a solid-liquid ratio of 1:(5~10) and stirring at 80~90℃ for 1~2 hours, filtering, washing with hexane 3 times, and vacuum drying to obtain an ultra-clean polypropylene product.