High-rigidity heat-resistant inorganic-organic composite nucleating agent

Abstract

The application belongs to the technical field of composite nucleating agents, and particularly relates to a high-rigidity heat-resistant inorganic-organic composite nucleating agent, which comprises the following components in terms of relative mass parts: rod-shaped attapulgite pre-treated by an epoxy silane 40-60 parts, methylacryloxy silane modified nano white carbon black 12-22 parts, organic phosphorus salt rigidifying nucleating agent 14-28 parts, heat-resistant tree-shaped hindered amine resin 3-8 parts, and polyester type high molecular dispersant 2-7 parts. The powder surface pre-modification process is adopted, the rod-shaped attapulgite and the nano white carbon black are respectively matched with corresponding silane coupling agents for grafting treatment, the finished product system does not add free silane, paraffin, stearic acid and other low molecular components, the volatile matter content is low under high temperature and high vacuum environment, and the problems of pinholes and aluminum layer falling off of the aluminum-plated film can be avoided.

Description

Technical Field

[0001] This invention belongs to the field of composite nucleating agent technology, and particularly relates to a high-rigidity, heat-resistant inorganic-organic composite nucleating agent. Background Technology

[0002] BOPP and CPP polyolefin metallized films are widely used in food packaging, daily chemical products, and electronic component encapsulation due to their lightweight, excellent barrier properties, and superior processability. The complete production process of these films involves multiple steps, including high-temperature melt extrusion at 220-260℃, biaxial stretching, and high-vacuum high-temperature metallization. These stringent processing conditions place multiple demands on the nucleating agents used: firstly, they need to effectively improve the film's flexural modulus and overall stiffness to meet the needs of downstream cutting and lamination; secondly, the nucleating agents must possess excellent thermal stability, remaining undecomposed and free of small molecule volatilization under high temperature and high vacuum conditions to avoid defects such as pinholes, haziness, reduced adhesion, or even peeling of the metallized layer; and thirdly, the nucleating agent powder must be uniformly dispersed to prevent the formation of crystal points on the film surface and to avoid excessively degrading the film's toughness, preventing film breakage during stretching and use. Currently, mainstream nucleating agents and modification systems in the industry cannot simultaneously meet all these comprehensive requirements, exhibiting numerous technical shortcomings.

[0003] Existing polyolefin nucleating agents are mainly divided into three categories: single organic nucleating agents, single inorganic fillers, and inorganic-organic physical blend nucleating agents. The defects of each type of product are as follows: The first category consists of single organic nucleating agents, commonly including sorbitol derivatives and organophosphates. These nucleating agents have high crystallization promotion efficiency and minimal impact on film transparency and haze. Some organophosphates can also slightly improve the rigidity and heat distortion temperature of polypropylene. However, these products generally have insufficient heat resistance, easily softening and decomposing in high-temperature environments above 230℃. After entering the vacuum metallization process, the small molecules produced by decomposition continue to volatilize, directly damaging the aluminum layer structure and causing the metallized film to be scrapped. Simultaneously, single organic nucleating agents have limited effect on improving film rigidity and modulus, failing to meet the production requirements of high-stiffness metallized films. Furthermore, under long-term thermo-oxidative aging conditions, nucleation activity and film mechanical properties decay rapidly.

[0004] The second category is single inorganic reinforcing fillers. The industry often uses powders such as talc, nano-silica, and rod-shaped attapulgite to improve the rigidity and heat resistance of polyolefins. Inorganic powders themselves have excellent thermal stability and outstanding rigidity and heat resistance effects. However, natural inorganic powders have weak heterogeneous nucleation activity and cannot effectively accelerate the crystallization rate of polypropylene when used alone. Ultrafine inorganic powders have a large specific surface area and are prone to agglomeration, forming a large number of visible crystal points in the film, which seriously affects the appearance quality of the film. In addition, most inorganic powders have a high oil absorption value, which will adsorb organic active components in the system and gradually cause the nucleation ability to decline. If the amount of powder added is increased in pursuit of rigidity improvement, it will also significantly reduce the elongation at break of the film, resulting in poor film toughness and easy film breakage problems during biaxial stretching and subsequent use.

[0005] The third category is traditional inorganic-organic physical blending composite nucleating agents. These products attempt to combine the advantages of organic nucleating agents and inorganic fillers, but due to limitations in formulation design and surface treatment technology, they still have significant shortcomings. First, most products simply physically mix inorganic powders with organic components without specifically modifying the surface of the inorganic powders. This results in poor interfacial compatibility between the powder and the polyolefin matrix, failing to completely resolve agglomeration issues and leading to frequent occurrences of excessive crystal points and haze in the thin film. Second, to improve powder dispersion, many existing compound systems directly add low-molecular-weight additives such as free silane coupling agents, paraffin wax, and stearic acid to the finished product. These substances have low boiling points and are highly volatile; they will escape in large quantities during high-temperature thin film processing and high-vacuum aluminum plating, causing pinholes and detachment of the aluminum layer. The core contributing factors are: First, some existing systems use dendritic resins with cross-linked end double bonds as heat-resistant additives. These resins are originally suitable for irradiation cross-linking processes, but polyolefin aluminized films only use pure thermal processing, so the cross-linked double bonds cannot function and instead cause macromolecular aggregation, further deteriorating the film's surface properties. Second, traditional compounding systems do not have a finely designed ratio of different functional inorganic powders, and cannot flexibly adjust the rigidity and heat resistance of products according to different application scenarios such as ordinary packaging films and high-temperature electronic films, thus limiting their applicability.

[0006] In summary, currently available single organic nucleating agents, single inorganic fillers, and conventional physical blending composite nucleating agents cannot simultaneously meet the comprehensive technical requirements of polyolefin metallized films for high rigidity, high heat resistance, low volatility, high powder dispersion, a balance of rigidity and toughness, and long-term aging resistance. The industry lacks dedicated composite nucleating agents specifically designed for the working conditions of BOPP and CPP polyolefin metallized films. Based on the numerous shortcomings of existing technologies, this invention proposes a high-rigidity, heat-resistant inorganic-organic composite nucleating agent. Through a series of improved designs, including differentiated powder surface pre-modification, dual inorganic system compounding, dedicated heat-resistant resin compatibility, and comprehensive control of low-molecular-weight substances, this agent overcomes various technical pain points of existing products and can be widely adapted to the production needs of polyolefin metallized films of different grades and application scenarios. Summary of the Invention

[0007] The purpose of this invention is to address the aforementioned technical problems by providing a high-rigidity, heat-resistant inorganic-organic composite nucleating agent.

[0008] In view of this, the present invention provides a high-rigidity heat-resistant inorganic-organic composite nucleating agent, comprising the following components by relative mass: 40-60 parts of rod-shaped attapulgite pretreated with epoxy silane, 12-22 parts of methacryloyloxysilane modified nano-silica, 14-28 parts of organophosphorus salt stiffening nucleating agent, 3-8 parts of heat-resistant dendritic hindered amine resin, and 2-7 parts of polyester polymeric dispersant.

[0009] Furthermore, the rod-shaped attapulgite is dolomite-type attapulgite, with a purity of ≥60% as determined by mineral composition analysis; the diameter of a single rod crystal is 20~50nm, the length is 500~1500nm, and the particle size D50 of the powder is ≤1μm as determined by a laser particle size analyzer.

[0010] Furthermore, the original particle size of the methacryloxysilane modified nano-silica is 400~500nm, and the silane grafting rate is ≥8% as determined by thermogravimetric analysis.

[0011] Furthermore, the organophosphate nucleating agent is a heat-resistant organophosphate mixture specifically for polyolefins, with a melting point ≥230℃.

[0012] Furthermore, the epoxy silane coupling agent used in the pretreatment of rod-shaped attapulgite is γ-glycidoxypropyltrimethoxysilane.

[0013] Furthermore, the heat-resistant dendritic hindered amine resin has no cross-linked end double bond structure, and the number-average molecular weight detected by gel permeation chromatography (GPC) is 20,000~30,000.

[0014] Furthermore, the polyester-type polymeric dispersant has a molecular weight of 8000~15000; the composite nucleating agent does not contain paraffin, stearic acid, or free silane-based low-molecular-weight volatile additives.

[0015] Furthermore, the comprehensive oil absorption value of the inorganic phase in the composite nucleating agent is ≤30g / 100g.

[0016] Furthermore, based on relative mass parts, the proportions of each component are as follows: 52 parts of rod-shaped attapulgite pretreated with epoxy silane, 16 parts of methacryloyloxysilane modified nano-silica, 18 parts of organophosphate salt stiffening nucleating agent, 4 parts of heat-resistant dendritic hindered amine resin, and 3 parts of polyester polymeric dispersant; the remainder consists of conventional trace excipients in the field of additives.

[0017] The beneficial effects of this invention are: Using a powder surface pre-modification process, rod-shaped attapulgite and nano-silica are respectively matched with corresponding silane coupling agents for grafting treatment. The finished product system does not contain low molecular weight components such as free silane, paraffin, and stearic acid. The volatile content is low under high temperature and high vacuum conditions, which can avoid the problems of pinholes and aluminum layer peeling in aluminum-coated films.

[0018] A compound system of rod-shaped attapulgite and modified nano-silica was adopted. The rod-shaped attapulgite mainly improves the rigidity of the film, while the modified nano-silica mainly improves the heat resistance of the system. Adjusting the ratio of the two groups can adapt to different application requirements, while improving the problems of easy agglomeration and low nucleation efficiency of single inorganic powders.

[0019] Using a dendritic hindered amine resin with the double bonds at the cross-linking ends, this resin only plays the role of anti-oxidation and capturing free radicals. It is suitable for the production process of hot extrusion and biaxial stretching of polyolefin films, and will not generate film crystal points due to macromolecular agglomeration, thus improving the long-term heat aging resistance of the product.

[0020] The overall oil absorption value of the inorganic phase in the composite system is controlled to be ≤30g / 100g, which reduces the adsorption of inorganic powder on organic nucleating components, ensures nucleation activity, and improves the dispersion effect of powder in polyolefin matrix.

[0021] High heat-resistant organic phosphate nucleating agents are selected, which have good compatibility with modified inorganic powders and hindered amine resins, and do not react with acids or bases. While improving the rigidity and heat resistance of the film, the original toughness of the film is preserved, reducing the probability of film breakage during production and use. Detailed Implementation

[0022] The technical solutions in the embodiments of this application will be clearly described below. Obviously, the described embodiments are only some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application are within the scope of protection of this application.

[0023] All raw material parameters of this invention are consistent with the product claims, and all indicators can be tested using the corresponding national standard methods: Dolomite-type rod-shaped attapulgite: mineral purity ≥60%; single rod crystal diameter 20~50nm, length 500~1500nm; powder D50 ≤1μm as detected by laser particle size analyzer.

[0024] Methacryloxysilane (KH570) modified nano-silica: original particle size 400~500nm; silane grafting rate ≥8% as determined by thermogravimetric analysis.

[0025] Organophosphate nucleating agent: Heat-resistant organophosphate mixture for polyolefins, melting point ≥230℃.

[0026] Heat-resistant hindered amine resin: no cross-linked end double bonds; number-average molecular weight of 20,000~30,000 as detected by gel permeation chromatography (GPC).

[0027] Polyester-type polymeric dispersant: molecular weight 8000~15000, free of low molecular weight volatile components.

[0028] γ-glycidoxypropyltrimethoxysilane (KH560): For use only in the pretreatment of rod-shaped attapulgite.

[0029] Matrix resin: Homopolymer polypropylene HD915CF, a commonly used resin for BOPP and CPP metallized films; this product can be used with other polyolefin film resins of the same type.

[0030] Trace amounts of compounded excipients: Polyolefin additives commonly include antioxidants and dust inhibitors, with each component accounting for less than 1% of the mass of the finished product.

[0031] The following process applies to all embodiments and is a standard industrial production process: Step 1: Wet treatment and silane modification of rod-shaped attapulgite: Add water to coarse attapulgite soil with a mesh size of 40 or higher, control the moisture content to 45±2%, and extrude it into sheet material through three rollers. Then, pile it up at room temperature for more than 24 hours to mature. The flake material was mixed with deionized water at a mass ratio of 1:10, and 2% of the flake material mass of the dispersant composition (sodium hexametaphosphate: low molecular weight polyacrylamide = 1:1) was added. The mixture was stirred at 1500 r / min for 3 h to prepare a suspension. It should be noted that this dispersant composition is only an auxiliary agent in the production process and is completely removed after subsequent pressure filtration and high-temperature drying, leaving no residue in the finished product; After the suspension is allowed to settle, it is filtered to obtain filter cake, dried at 90℃ until the moisture content of the material is <2%, and then mechanically crushed to obtain primary attapulgite powder. Primary attapulgite is fed into an air jet mill, where KH560 silane coupling agent is sprayed via atomization for dry grafting modification. The air jet pressure is controlled at 0.6~0.8MPa. After discharge, modified rod-shaped attapulgite is obtained for later use. Step 2: Inorganic powder premixing: Modified rod-shaped attapulgite and KH570 modified nano-silica were added to a low-speed premixer according to the specified ratio and mixed at room temperature for 5 minutes to obtain composite inorganic powder. Step 3: Mix all components. Add organic phosphate salt stiffening and nucleating agent, heat-resistant dendritic hindered amine resin, polyester polymer dispersant and trace amounts of compounded excipients to the composite inorganic powder in sequence; mix at 900~1100 r / min, stir at room temperature for 10 min to ensure uniform mixing of materials. Step 4: Crushing and Grading The mixture is finely pulverized by a universal pulverizer, and then agglomerated particles are removed by an air classifier. Step 5: Screen the finished product. After grading, the material is passed through a 300-mesh standard sieve. The material that passes through the sieve is collected, sealed, and packaged to obtain the finished composite nucleating agent. It should be noted that this process only modifies the surface of inorganic powders through grafting, and the finished product does not contain low-molecular-weight substances such as free silanes, paraffin, and stearic acid. Specific implementation examples: All formulations below are based on relative mass parts. The comprehensive oil absorption value of the inorganic phase in all examples was tested according to GB / T17122, and the results were all ≤30g / 100g.

[0033] Example 1: The product contains 52 parts of rod-shaped attapulgite pretreated with epoxy silane, 16 parts of KH570 modified nano-silica, 18 parts of organophosphorus salt stiffening nucleating agent, 4 parts of heat-resistant dendritic hindered amine resin, 3 parts of polyester polymeric dispersant, and the remainder is conventional trace excipients in the field of additives. The mass percentage of each single component in the finished product is less than 1%.

[0034] Example 2: The product contains 48 parts of rod-shaped attapulgite pretreated with epoxy silane, 18 parts of KH570 modified nano-silica, 20 parts of organophosphorus salt stiffening nucleating agent, 5 parts of heat-resistant dendritic hindered amine resin, 4 parts of polyester polymeric dispersant, and the remainder is conventional trace excipients in the field of additives. The mass percentage of each single component in the finished product is less than 1%.

[0035] Example 3: The product contains 45 parts of rod-shaped attapulgite pretreated with epoxy silane, 20 parts of KH570 modified nano-silica, 17 parts of organophosphorus salt stiffening nucleating agent, 6 parts of heat-resistant dendritic hindered amine resin, 5 parts of polyester polymeric dispersant, and the remainder is conventional trace excipients in the field of additives. The mass percentage of each single component in the finished product is less than 1%.

[0036] Example 4: The product contains 43 parts of rod-shaped attapulgite pretreated with epoxy silane, 21 parts of KH570 modified nano-silica, 15 parts of organophosphorus salt stiffening nucleating agent, 7 parts of heat-resistant dendritic hindered amine resin, 6 parts of polyester polymeric dispersant, and the remainder is conventional trace excipients in the field of additives. The mass percentage of each single component in the finished product is less than 1%.

[0037] Example 5: The product contains 42 parts of rod-shaped attapulgite pretreated with epoxy silane, 22 parts of KH570 modified nano-silica, 16 parts of organophosphorus salt stiffening nucleating agent, 7 parts of heat-resistant dendritic hindered amine resin, 6 parts of polyester polymeric dispersant, and the remainder is conventional trace excipients in the field of additives. The mass percentage of each single component in the finished product is less than 1%.

[0038] Scale settings: All comparative examples were tested under the same conditions as the examples. Nucleating agents and various additives were added at 1.0% of the total mass of polypropylene resin, following the principle of a single variable.

[0039] Comparative Example 1: Blank group: pure polypropylene HD915CF, without any nucleating agents or additives.

[0040] Comparative Example 2: Single organic nucleating agent group: only organic phosphate salt nucleating agents are added, and the amount added is consistent with the absolute proportion of this component in the resin in Example 1. No inorganic powder, hindered amine resin and dispersant are added.

[0041] Comparative Example 3: Unmodified inorganic powder group: The modified rod-shaped attapulgite and modified nano-silica in Example 1 were replaced with the original powder that had not been treated with silane, while the other components, proportions and preparation processes remained unchanged.

[0042] Comparative Example 4: Group containing free silane: Add 4 parts of KH560 and KH570 compound silane to the finished product of Example 1, while keeping other conditions unchanged.

[0043] Comparative Example 5: End-double bond resin group: The dendritic hindered amine resin without cross-linked end-double bonds in Example 1 is replaced with the same type of resin with cross-linked end-double bonds, while the other components and proportions remain unchanged.

[0044] Comparative Example 6: Commercially available control group: Commercially available inorganic-organic composite nucleating agent for polyolefin films (physical blend system, containing low molecular weight lubricant) was selected.

[0045] Performance testing: Sample preparation: Ingredients: Mix the samples from each embodiment and comparative example with polypropylene HD915CF in the specified proportions until homogeneous; Extrusion granulation: Twin-screw extruder temperature settings: Zone 1 210℃, Zone 2 230℃, Zone 3 245℃, Die 240℃, Screw speed 240r / min, material is melted and extruded and then water-cooled and pelletized; Film preparation: Polypropylene films with a thickness of 22 μm were prepared using a casting and stretching equipment; Vacuum aluminum plating: Thin-film aluminum plating process parameters: Temperature 120℃, Vacuum degree 8×10 -4 Pa.

[0046] The test items, execution standards, and test conditions are shown in the table below: ; The test results are shown in the table below: ; ; Test Result Analysis: Rigidity and toughness: Compared to blank polypropylene, the flexural modulus of the films in the embodiments of this invention is increased by 30% to 54%, showing a significant increase in stiffness; Comparative Example 2, which only uses an organic nucleating agent, shows a limited increase in modulus. Comparative Example 3, using unmodified inorganic powder, has a rigidity close to that of this product, but its film elongation at break is significantly reduced, resulting in insufficient toughness. The elongation at break in all embodiments of this invention remains above 710%, demonstrating a good balance between rigidity and toughness.

[0047] Heat resistance: As the proportion of modified nano-silica in the formulation increases, the heat distortion temperature of the film gradually rises, reaching 124℃ in Example 5. The heat distortion temperature of the blank resin is 95℃, while the highest temperature of the other traditional comparative examples is only 106℃. This product has a significant advantage in heat resistance and can meet the requirements of different temperature conditions.

[0048] Low volatility and compatibility with aluminizing: Comparative Example 4, with added free silane, had a volatile content of 1.35% at 260°C, resulting in numerous pinholes and poor adhesion in the aluminum layer after aluminizing. Commercially available conventional composite nucleating agents (Comparative Example 6), containing low-molecular-weight lubricants, also exhibited high volatile content and aluminum plating defects. In all embodiments of this invention, the volatile content was ≤0.08%, resulting in no pinholes after aluminizing, strong aluminum layer adhesion, and suitability for vacuum aluminizing production requirements.

[0049] Powder dispersion and film appearance: In the groups where the inorganic powder was not modified and the resin contained cross-linked double bonds, obvious powder agglomeration was observed, resulting in a large number of crystal points and high haze in the film. This product, through powder modification and oil absorption value control, achieves uniform powder dispersion, produces a film without visible crystal points, low haze, and excellent appearance quality.

[0050] Heat aging resistance: The tensile strength retention rates after thermo-oxidative aging were all below 87% in the blank group, the single organic nucleating agent group, and the unmodified inorganic powder group. Resins with crosslinked terminal double bonds also showed a decrease in anti-aging ability. This invention uses a double-bond-free, dendritic hindered amine resin, achieving a strength retention rate of over 96% after aging and exhibiting stable performance over long-term use.

[0051] Compared with existing technologies, this invention can prepare products with different rigidity and heat resistance levels by changing the ratio of two inorganic powders, and its application scope covers ordinary packaging aluminized film and high-temperature working condition aluminized film.

[0052] The powder pre-modification process ensures that the finished product contains no free low molecular weight components and is not easily volatilized under high temperature and high vacuum conditions, which can effectively avoid problems such as pinholes and aluminum layer peeling in the aluminum-coated film.

[0053] Its overall mechanical, heat resistance, and aging resistance properties are superior to those of single organic nucleating agents, single inorganic fillers, and conventional composite nucleating agents on the market, while also taking into account film transparency and surface quality.

[0054] The production process can be achieved using existing general-purpose equipment for powder additives. The process is simple, the raw materials are readily available, and there is no need to modify downstream film-making or aluminizing equipment, which facilitates industrial production and promotion.

[0055] The components are well-matched and will not react during storage. Nucleation, stiffening, and heat resistance properties remain stable over a long period.

[0056] The embodiments of this application have been described above. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A high-rigidity, heat-resistant inorganic-organic composite nucleating agent, characterized in that, Based on relative mass parts, it includes the following components: 40-60 parts of rod-shaped attapulgite pretreated with epoxy silane, 12-22 parts of methacryloyloxysilane modified nano-silica, 14-28 parts of organophosphorus salt stiffening nucleating agent, 3-8 parts of heat-resistant dendritic hindered amine resin, and 2-7 parts of polyester polymeric dispersant.

2. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, The rod-shaped attapulgite is dolomite-type attapulgite, with a purity of ≥60% as determined by mineral composition analysis; the diameter of a single rod crystal is 20~50nm, the length is 500~1500nm, and the particle size D50 of the powder is ≤1μm as determined by a laser particle size analyzer.

3. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, The original particle size of the methacryloxysilane-modified nano-silica is 400~500nm, and the silane grafting rate is ≥8% as determined by thermogravimetric analysis.

4. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, The organophosphate nucleating agent is a heat-resistant organophosphate mixture specifically for polyolefins, with a melting point ≥230℃.

5. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, The epoxy silane coupling agent used for pretreatment of rod-shaped attapulgite is γ-glycidoxypropyltrimethoxysilane.

6. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, The heat-resistant, dendritic hindered amine resin has no cross-linked end double bond structure, and its number-average molecular weight, as detected by gel permeation chromatography, is 20,000 to 30,000.

7. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, The polyester-type polymeric dispersant has a molecular weight of 8000~15000; the composite nucleating agent does not contain paraffin, stearic acid, or free silane-based low-molecular-weight volatile additives.

8. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, The comprehensive oil absorption value of the inorganic phase in the composite nucleating agent is ≤30g / 100g.

9. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, Based on relative mass parts, the proportions of each group are as follows: 52 parts of rod-shaped attapulgite pretreated with epoxy silane, 16 parts of methacryloyloxysilane modified nano-silica, 18 parts of organophosphate salt stiffening nucleating agent, 4 parts of heat-resistant dendritic hindered amine resin, and 3 parts of polyester polymeric dispersant; the remainder consists of conventional trace excipients in the field of additives.

10. The high-rigidity, heat-resistant inorganic-organic composite nucleating agent according to claim 1, characterized in that, Based on relative mass parts, the proportions of each group are as follows: 42 parts of rod-shaped attapulgite pretreated with epoxy silane, 22 parts of methacryloyloxysilane modified nano-silica, 16 parts of organophosphate salt stiffening nucleating agent, 7 parts of heat-resistant dendritic hindered amine resin, and 6 parts of polyester polymeric dispersant; the remainder consists of conventional trace excipients in the field of additives.