High-temperature stable antireflection nucleating agent and preparation method thereof
By using a composite system of sorbitol nucleating agent with nano-titanium dioxide, phthalocyanine blue, sodium alginate grafted cyclodextrin and stabilizing agents, the problems of yellowing and increased haze of polypropylene nucleating agents at high temperatures were solved, and the transparency and structural stability of polypropylene products at high temperatures were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN CHANGXING ISLAND QINGTENGSHU NEW MATERIAL TECHNOLOGY CO LTD
- Filing Date
- 2026-05-08
- Publication Date
- 2026-06-16
AI Technical Summary
Existing polypropylene nucleating agents are prone to yellowing and increased haze under high-temperature conditions, failing to meet the high-temperature stability requirements of food packaging, medical packaging, and home appliance panels.
A composite system of sorbitol nucleating agent, nano-titanium dioxide, phthalocyanine blue, sodium alginate grafted cyclodextrin, stabilizers and antioxidants is adopted. Through light scattering, free radical capture and antioxidant effects, the nucleating agent is ensured to be structurally stable at high temperature, and yellowing and haze increase are inhibited.
It maintains the transparency and structural stability of polypropylene products at a processing temperature of 220-240℃, and the haze changes little after long-term use, meeting the requirements for use in high-temperature environments.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer nucleating agent technology, and in particular to a high-temperature stable anti-reflection nucleating agent and its preparation method. Background Technology
[0002] Polypropylene is widely used in food packaging (such as transparent lunch boxes), medical packaging (such as infusion bottles), and home appliance components (such as transparent panels) due to its lightweight and chemical resistance. Sorbitol-based nucleating agents are the mainstream choice for polypropylene antireflection, such as Millad-NX800. However, these applications have stringent requirements for high-temperature stability: food packaging needs to withstand 121°C steam sterilization, and traditional nucleating agents are prone to yellowing after processing, affecting the appearance of the food; medical infusion bottles need to be injection molded at 220°C to ensure sterility, and existing nucleating agents will decompose at this temperature to produce small molecule volatiles, such as benzaldehyde, which does not meet medical-grade requirements; home appliance panels need to be used for a long time in an environment of 60°C, such as kitchen appliances, and after 300 hours, the transparency will decrease, leading to appearance deterioration.
[0003] Existing attempts to improve the technology have obvious limitations: simply adding antioxidants can lead to "blooming," where the additives precipitate onto the surface, increasing haze; adding inorganic opacifiers can mask yellowing, but it will increase haze and lose the advantage of transparency; traditional cyclodextrins can capture volatile aldehydes, but due to their poor compatibility with polypropylene, their migration rate is high after 300 hours, resulting in a decrease in the anti-yellowing effect.
[0004] Therefore, based on the relevant technologies mentioned above, there is an urgent need to develop a high-temperature stable anti-penetration nucleating agent and its preparation method. Summary of the Invention
[0005] In view of this, the purpose of this invention is to provide a high-temperature stable anti-reflection nucleating agent and its preparation method. This nucleating agent can maintain structural stability at a processing temperature of 220-240℃, significantly inhibit the yellowing of polypropylene products, and exhibits small changes in haze and excellent transparency after long-term use.
[0006] To achieve the above objectives, the present invention provides a high-temperature stable anti-reflection nucleating agent and its preparation method.
[0007] A high-temperature stable transparent nucleating agent comprises the following raw materials in parts by weight: 50-80 parts of sorbitol nucleating agent, 1-3 parts of inorganic pigment, 0.5-2 parts of organic pigment, 3-8 parts of stabilizing agent, 2-5 parts of sodium alginate grafted cyclodextrin, and 10-4 parts of antioxidant.
[0008] Preferably, the sorbitol nucleating agent is 1,3-bis(3,4-dimethylbenzyl)sorbitol, because the methyl group on the benzene ring can enhance the rigidity of the molecule, thereby increasing the thermal decomposition temperature. As a core nucleating unit, it induces polypropylene to form fine spherulites of 0.5-1 μm, thereby reducing the basic haze.
[0009] Preferably, the inorganic pigment is nano-titanium dioxide with a particle size of 10-30nm. This avoids light shading when the particle size is greater than 50nm, resulting in a large specific surface area, improved light scattering efficiency, scattering long wavelengths of visible light, reducing haze, and reflecting ultraviolet light. This inhibits the breakage of polypropylene molecular chains and works synergistically with sorbitol to reduce haze.
[0010] Preferably, the organic pigment is phthalocyanine blue, which can absorb 400-450nm yellowing light, compensate for the yellowing visual effect, and form a "light-modulating pair" with TiO2 to reduce the yellowing index.
[0011] Preferably, the stabilizing agent is obtained by compounding aluminum hydroxyphosphate and magnesium sulfate whiskers in a mass ratio of 1:1. The aluminum hydroxyphosphate is used to inhibit the hydrolysis of the nucleating agent, and the magnesium sulfate whiskers have an aspect ratio of 20:1, which can block oxygen. The aluminum salt neutralizes the acidic substances and nucleating agent degradation products generated during processing. The whiskers form a "physical barrier" in polypropylene, thereby reducing oxygen permeability.
[0012] Preferably, the grafting rate of the sodium alginate grafted cyclodextrin is 15%-20%. If the grafting rate is too small, the anchoring will be insufficient, and if the grafting rate is too large, the compatibility will decrease. The cyclodextrin cavity captures free radicals and can resist yellowing. The lipophilic sodium alginate grafted chain is anchored on the polypropylene matrix, solving the problem of easy loss of traditional cyclodextrin.
[0013] Preferably, the antioxidant is a compound of phenolic antioxidant 1010 and phosphite antioxidant 168 in a mass ratio of 1:1. Phenolic antioxidant 1010 can capture free radicals and takes effect quickly in the early stage of processing, while phosphite antioxidant 168 can decompose hydroperoxides and continue to act in long-term use, thus extending the antioxidant cycle. The compounding of the two can avoid the imbalance of consumption of a single antioxidant.
[0014] A method for preparing a high-temperature stable anti-reflection nucleating agent includes the following steps: Step S1. Premixing: Add inorganic and organic pigments to a high-speed mixer and stir at 50-60℃ for 10-15 minutes to obtain pigment premix; Step S2. Main mixing: Add sorbitol nucleating agent and stabilizer to the pigment premix, and stir at 80-90℃ for 20-30 min. At this temperature, the nucleating agent softens but does not melt, which is conducive to its combination with the additive. Then add sodium alginate grafted cyclodextrin and antioxidant, reduce the speed to 1000 r / min to avoid shearing damage to the cyclodextrin structure, and continue stirring for 15-20 min until no visible particles are observed, and the mixture is obtained. Step S3. Granulation and Drying: The mixture is fed into a twin-screw granulator and granulated at 100-120℃. After granulation, it is dried in a vacuum drying oven at 80-90℃ for 4-6 hours to ensure that the moisture content is ≤0.1%. Excessive moisture content will cause bubbles to be generated during processing. The mixture is then crushed through an 80-100 mesh sieve to ensure that it is mixed evenly with polypropylene in the subsequent process to obtain a high-temperature stable permeability-enhancing nucleating agent.
[0015] Preferably, the high-speed mixer in step S1 has a rotation speed of 1500 r / min and a heating rate of 2℃ / min for 50-60℃. The purpose is to avoid phthalocyanine blue discoloration at high temperatures. Step S1 is a key step for pigment dispersion. The dispersed particle size is monitored by a laser particle size analyzer. The dispersed particle size must be ≤50nm to ensure that the pigment is uniformly dispersed without agglomeration. If it is >50nm, the stirring time needs to be extended by 5min.
[0016] Preferably, the temperature of the twin-screw granulator in step S3 is controlled in stages: 80°C for the feeding stage, 100°C for the compression stage, and 110°C for the homogenization stage, to avoid premature consumption of antioxidants due to temperatures exceeding 120°C.
[0017] Application of a high-temperature stable anti-reflection nucleating agent, wherein the high-temperature stable anti-reflection nucleating agent is used in medical infusion bottles, microwave oven food containers and transparent household appliance panels.
[0018] Preferably, the high-temperature stable anti-reflection nucleating agent is added at a rate of 0.3%-0.4% when used in medical infusion bottles, with an injection molding temperature of 220°C and a sterilization temperature of 121°C / 20min.
[0019] Preferably, the amount of the high-temperature stable anti-reflective nucleating agent added when used in microwave oven food containers is 0.2%-0.3%, the injection molding temperature is 200℃, and the operating temperature is ≤140℃.
[0020] Preferably, the high-temperature stable anti-reflection nucleating agent is added at a rate of 0.4%-0.5% when used in transparent home appliance panels, with an extrusion temperature of 210°C and a long-term use temperature of 60°C.
[0021] The beneficial effects of this invention are: This invention provides a high-temperature stable anti-reflection nucleating agent and its preparation method. This invention improves the visual transparency of polypropylene through the synergistic effect of inorganic and organic pigments and can reduce haze compared with a single sorbitol nucleating agent.
[0022] The sodium alginate grafted cyclodextrin provided by this invention has excellent UV resistance and free radical scavenging ability. Combined with stabilizing agents, it can inhibit yellowing during high-temperature processing.
[0023] The antioxidant provided by this invention can stabilize the crystal structure after high-temperature processing, resulting in a low haze recovery rate after processing at 220-240℃ and minimal haze change after long-term use.
[0024] The components in this invention have good compatibility and are uniformly dispersed in the polypropylene matrix, without affecting the processing flowability. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.
[0026] Example 1: A method for preparing a high-temperature stable anti-reflection nucleating agent, comprising the following steps: S1. Premixing: Add 10g of nano-titanium dioxide with a particle size of 10-30nm and 5g of phthalocyanine blue to a high-speed mixer with a speed of 1500r / min. Heat the mixture to 50℃ at a heating rate of 2℃ / min and stir at 50℃ for 10min to obtain the pigment premix. The premixing step is a key step in pigment dispersion. Monitor the dispersed particle size with a laser particle size analyzer. The dispersed particle size must be ≤50nm to ensure uniform dispersion of the pigment without agglomeration. If the particle size is >50nm, the stirring time needs to be extended by 5min. S2. Main Mixing: Add 500g of sorbitol nucleating agent and 30g of stabilizer to the pigment premix. Stir at 80℃ for 20min. At this temperature, the nucleating agent softens but does not melt, which is beneficial for combining with the stabilizer. Then add sodium alginate grafted cyclodextrin with a grafting rate of 15%-20% and an antioxidant. Reduce the stirring speed to 1000r / min to avoid shearing damage to the cyclodextrin structure. Continue stirring for 15min until no visible particles are observed, and the mixture is obtained. The stabilizer is obtained by compounding aluminum hydroxyphosphate salt and magnesium sulfate whiskers in a mass ratio of 1:1. The aspect ratio of magnesium sulfate whiskers is 20:1. The antioxidant is obtained by compounding phenolic antioxidant 1010 and phosphite antioxidant 168 in a mass ratio of 1:1. S3. Granulation and Drying: The mixture is fed into a twin-screw granulator and granulated at 100℃. After granulation, it is dried in a vacuum drying oven at 80℃ for 4 hours to ensure that the moisture content is ≤0.1%. Excessive moisture content will cause bubbles to form during processing. The mixture is then pulverized through an 80-100 mesh sieve to ensure uniform mixing with polypropylene in the subsequent process, resulting in a high-temperature stable permeability-enhancing nucleating agent. The temperature of the twin-screw granulator is controlled in stages: 80℃ in the feeding stage, 100℃ in the compression stage, and 110℃ in the homogenization stage, to avoid premature consumption of antioxidants due to temperatures exceeding 120℃.
[0027] Example 2: A method for preparing a high-temperature stable anti-reflection nucleating agent, comprising the following steps: S1. Premixing: Add 20g of nano-titanium dioxide with a particle size of 10-30nm and 10g of phthalocyanine blue to a high-speed mixer with a speed of 1500r / min. Heat the mixture to 53℃ at a heating rate of 2℃ / min and stir at 53℃ for 12min to obtain the pigment premix. The premixing step is a key step in pigment dispersion. Monitor the dispersed particle size with a laser particle size analyzer. The dispersed particle size must be ≤50nm to ensure uniform dispersion of the pigment without agglomeration. If the particle size is >50nm, the stirring time needs to be extended by 5min. S2. Main Mixing: Add 600g of sorbitol nucleating agent and 50g of stabilizer to the pigment premix. Stir at 83℃ for 23min. At this temperature, the nucleating agent softens but does not melt, which is beneficial for combining with the stabilizer. Then add sodium alginate grafted cyclodextrin with a grafting rate of 15%-20% and an antioxidant. Reduce the stirring speed to 1000r / min to avoid shearing damage to the cyclodextrin structure. Continue stirring for 17min until no visible particles are observed, and the mixture is obtained. The stabilizer is obtained by compounding aluminum hydroxyphosphate salt and magnesium sulfate whiskers in a mass ratio of 1:1. The aspect ratio of magnesium sulfate whiskers is 20:1. The antioxidant is obtained by compounding phenolic antioxidant 1010 and phosphite antioxidant 168 in a mass ratio of 1:1. S3. Granulation and Drying: The mixture is fed into a twin-screw granulator and granulated at 105℃. After granulation, it is dried in a vacuum drying oven at 83℃ for 4.5 hours to ensure that the moisture content is ≤0.1%. Excessive moisture content will cause bubbles to form during processing. The mixture is then pulverized through an 80-100 mesh sieve to ensure uniform mixing with polypropylene in the subsequent process, resulting in a high-temperature stable permeability-enhancing nucleating agent. The temperature of the twin-screw granulator is controlled in stages: 80℃ in the feeding stage, 100℃ in the compression stage, and 110℃ in the homogenization stage, to avoid premature consumption of antioxidants due to temperatures exceeding 120℃.
[0028] Example 3: A method for preparing a high-temperature stable anti-reflection nucleating agent, comprising the following steps: S1. Premixing: Add 25g of nano-titanium dioxide with a particle size of 10-30nm and 15g of phthalocyanine blue to a high-speed mixer with a speed of 1500r / min. Heat the mixture to 56℃ at a heating rate of 2℃ / min and stir at 56℃ for 14min to obtain the pigment premix. The premixing step is a key step in pigment dispersion. Monitor the dispersed particle size with a laser particle size analyzer. The dispersed particle size must be ≤50nm to ensure uniform dispersion of the pigment without agglomeration. If the particle size is >50nm, the stirring time needs to be extended by 5min. S2. Main mixing: Add 700g of sorbitol nucleating agent and 70g of stabilizer to the pigment premix, and stir at 86℃ for 26min. At this temperature, the nucleating agent softens but does not melt, which is conducive to its combination with the stabilizer. Then add sodium alginate grafted cyclodextrin with a grafting rate of 15%-20% and antioxidant. Reduce the stirring speed to 1000r / min to avoid shearing damage to the cyclodextrin structure. Continue stirring for 19min until no visible particles are observed, and the mixture is obtained. The stabilizer is obtained by compounding aluminum hydroxyphosphate salt and magnesium sulfate whiskers in a mass ratio of 1:1. The aspect ratio of magnesium sulfate whiskers is 20:1. The antioxidant is obtained by compounding phenolic antioxidant 1010 and phosphite antioxidant 168 in a mass ratio of 1:1. S3. Granulation and Drying: The mixture is fed into a twin-screw granulator and granulated at 115℃. After granulation, it is dried in a vacuum drying oven at 86℃ for 5 hours to ensure that the moisture content is ≤0.1%. Excessive moisture content will cause bubbles to form during processing. The mixture is then pulverized through an 80-100 mesh sieve to ensure uniform mixing with polypropylene in the subsequent process, resulting in a high-temperature stable anti-reflective nucleating agent. The temperature of the twin-screw granulator is controlled in stages: 80℃ in the feeding stage, 100℃ in the compression stage, and 110℃ in the homogenization stage, to avoid premature consumption of antioxidants due to temperatures exceeding 120℃.
[0029] Example 4: A method for preparing a high-temperature stable anti-reflection nucleating agent, comprising the following steps: S1. Premixing: Add 30g of nano-titanium dioxide with a particle size of 10-30nm and 20g of phthalocyanine blue to a high-speed mixer with a speed of 1500r / min. Heat the mixture to 60℃ at a heating rate of 2℃ / min and stir at 60℃ for 15min to obtain the pigment premix. The premixing step is a key step in pigment dispersion. Monitor the dispersed particle size with a laser particle size analyzer. The dispersed particle size must be ≤50nm to ensure uniform dispersion of the pigment without agglomeration. If it is >50nm, the stirring time needs to be extended by 5min. S2. Main Mixing: Add 800g of sorbitol nucleating agent and 80g of stabilizer to the pigment premix. Stir at 90℃ for 30min. At this temperature, the nucleating agent softens but does not melt, which is beneficial for combining with the stabilizer. Then add sodium alginate grafted cyclodextrin with a grafting rate of 15%-20% and an antioxidant. Reduce the stirring speed to 1000r / min to avoid shearing damage to the cyclodextrin structure. Continue stirring for 20min until no visible particles are observed, and the mixture is obtained. The stabilizer is obtained by compounding aluminum hydroxyphosphate salt and magnesium sulfate whiskers in a mass ratio of 1:1. The aspect ratio of magnesium sulfate whiskers is 20:1. The antioxidant is obtained by compounding phenolic antioxidant 1010 and phosphite antioxidant 168 in a mass ratio of 1:1. S3. Granulation and Drying: The mixture is fed into a twin-screw granulator and granulated at 120℃. After granulation, it is dried in a vacuum drying oven at 90℃ for 6 hours to ensure that the moisture content is ≤0.1%. Excessive moisture content will cause bubbles to form during processing. The mixture is then pulverized through an 80-100 mesh sieve to ensure uniform mixing with polypropylene in the subsequent process, resulting in a high-temperature stable permeability-enhancing nucleating agent. The temperature of the twin-screw granulator is controlled in stages: 80℃ in the feeding stage, 100℃ in the compression stage, and 110℃ in the homogenization stage, to avoid premature consumption of antioxidants due to temperatures exceeding 120℃.
[0030] Example 5: A process for using a high-temperature stable anti-reflection nucleating agent in the preparation of medical infusion bottles, comprising the following steps: S1. Raw material preparation: Basic raw material: Medical grade homopolymer polypropylene resin (melt index 2.5-3.0 g / 10 min, ash content ≤0.01%, conforming to USP Class VI standard); Nucleating agent: The high-temperature stable anti-reflection nucleating agent prepared in Example 1 (addition amount 0.3%, relative to the mass of polypropylene, ensuring haze ≤16% and no precipitation); Auxiliary ingredients: Medical-grade antioxidant (additional 0.1% antioxidant 1010 to prevent polypropylene degradation and synergistic effect with the antioxidant in the nucleating agent).
[0031] S2. Melt blending: Equipment: Twin-screw extruder (screw length-to-diameter ratio 40:1, food-grade chrome-plated screw to avoid contamination by impurities); Process parameters: Feeding section temperature: 160℃ (to prevent polypropylene from melting and clumping prematurely); Compression section temperature: 180℃ (initial melting to ensure uniform dispersion of the nucleating agent); Homogenization temperature: 210℃ (the nucleating agent is stable at this temperature, with no thermal decomposition, ensuring a dispersed particle size ≤5μm); Screw speed: 300 r / min (high shear ensures dispersion and avoids molecular chain breakage due to excessive shear); Vacuum level: -0.09MPa (removal of trace volatiles, such as small molecules produced by the degradation of polypropylene).
[0032] Product: Polypropylene masterbatch obtained by granulation (particle size 3-4mm, moisture ≤0.05%, to avoid air bubbles in subsequent injection molding).
[0033] S3. Injection molding: Equipment: Medical-grade injection molding machine (cavity mirror polishing, Ra≤0.02μm, to avoid residual impurities); Process parameters: Barrel temperature: 190℃ in the front section, 200℃ in the middle section, and 210℃ at the nozzle (the nucleating agent is structurally stable at this temperature, inducing polypropylene to form fine spherulites). Injection pressure: 80MPa (to ensure complete mold filling and avoid material shortage in thin areas of the infusion bottle wall); Holding pressure: 50MPa, holding time: 15s (to reduce internal stress and prevent cracking after sterilization). Mold temperature: 40℃ (slow cooling to promote nucleating agent-induced crystallization and reduce haze).
[0034] Molded product: Medical infusion bottle preform (capacity 500mL, wall thickness 1.2-1.5mm, no shrinkage marks on the surface).
[0035] S4. Sterilization and post-treatment: Sterilization process: 121℃ saturated steam sterilization (20min, in accordance with GB 15593-1995 standard for medical infusion containers); Post-processing: After sterilization, allow to cool naturally to room temperature (avoid sudden cooling to prevent stress), and inspect the appearance (no yellowing, no cracks). Key indicators: haze ≤16% after sterilization (initial 15%), yellowness index Δb≤1.2 (phthalocyanine blue and sodium alginate grafted cyclodextrin in the nucleating agent synergistically inhibit yellowing), and light transmittance ≥90%.
[0036] Example 6: A process for using a high-temperature stable anti-reflection nucleating agent in the preparation of medical infusion bottles, comprising the following steps: S1. Raw material preparation: Basic raw material: Medical grade homopolymer polypropylene resin (melt index 2.5-3.0 g / 10 min, ash content ≤0.01%, conforming to USP Class VI standard); Nucleating agent: High-temperature stable anti-reflection nucleating agent prepared in Example 2 (addition amount 0.4%, relative to the mass of polypropylene, ensuring haze ≤16% and no precipitation); Auxiliary ingredients: Medical-grade antioxidant (additional 0.1% antioxidant 1010 to prevent polypropylene degradation and synergistic effect with the antioxidant in the nucleating agent).
[0037] S2. Melt blending: Equipment: Twin-screw extruder (screw length-to-diameter ratio 40:1, food-grade chrome-plated screw to avoid contamination by impurities); Process parameters: Feeding section temperature: 170℃ (to prevent polypropylene from melting and clumping prematurely); Compression section temperature: 190℃ (initial melting to ensure uniform dispersion of the nucleating agent); Homogenization zone temperature: 220℃ (the nucleating agent is stable at this temperature, with no thermal decomposition, ensuring a dispersed particle size ≤5μm); Screw speed: 350 r / min (high shear ensures dispersion and avoids molecular chain breakage due to excessive shear); Vacuum level: -0.09MPa (removal of trace volatiles, such as small molecules produced by the degradation of polypropylene).
[0038] Product: Polypropylene masterbatch obtained by granulation (particle size 3-4mm, moisture ≤0.05%, to avoid air bubbles in subsequent injection molding).
[0039] S3. Injection molding: Equipment: Medical-grade injection molding machine (cavity mirror polishing, Ra≤0.02μm, to avoid residual impurities); Process parameters: Barrel temperature: 190℃ in the front section, 200℃ in the middle section, and 220℃ at the nozzle (the nucleating agent is structurally stable at this temperature, inducing polypropylene to form fine spherulites). Injection pressure: 90MPa (to ensure complete mold filling and avoid material shortage in thin sections of the infusion bottle wall); Holding pressure: 60MPa, holding time: 15-20s (to reduce internal stress and prevent cracking after sterilization). Mold temperature: 50℃ (slow cooling to promote nucleating agent-induced crystallization and reduce haze).
[0040] Molded product: Medical infusion bottle preform (capacity 500mL, wall thickness 1.2-1.5mm, no shrinkage marks on the surface).
[0041] S4. Sterilization and post-treatment: Sterilization process: 121℃ saturated steam sterilization (20min, in accordance with GB 15593-1995 standard for medical infusion containers); Post-processing: After sterilization, allow to cool naturally to room temperature (avoid sudden cooling to prevent stress), and inspect the appearance (no yellowing, no cracks). Key indicators: haze ≤16% after sterilization (initial 15%), yellowness index Δb≤1.2 (phthalocyanine blue and sodium alginate grafted cyclodextrin in the nucleating agent synergistically inhibit yellowing), and light transmittance ≥90%.
[0042] Example 7: A process for using a high-temperature stable anti-reflection nucleating agent to prepare microwave oven food containers, comprising the following steps: S1. Raw material preparation: Basic raw material: food-grade copolymer polypropylene resin (melt index 3.0-3.5g / 10min, excellent impact resistance, preventing embrittlement after microwave heating); Nucleating agent: High-temperature stable anti-reflective nucleating agent prepared in Example 1 (addition amount 0.2%, balancing transparency and cost); Auxiliary raw materials: food-grade lubricant (0.1% ethylene bis-stearamide, which improves release properties and does not affect the dispersion of nucleating agents).
[0043] S2. Melt blending and granulation: Equipment: Twin-screw extruder (length-to-diameter ratio 36:1, conventional food-grade screw); Process parameters: Feeding section temperature: 150℃; Compression section temperature: 170℃; Homogenization section temperature: 190℃ (the nucleating agent has the best permeability enhancement effect at this temperature, and the antioxidant is not consumed prematurely). Screw speed: 250 r / min (moderate shear to ensure compatibility between nucleating agent and polypropylene); Granulation: Cut into pellets of 3mm length and dry to a moisture content of ≤0.1% (to avoid air bubbles during injection molding).
[0044] S3. Injection molding (Key points: thin-walled molding, smooth edges and corners): Equipment: Horizontal injection molding machine (cavity corresponds to the shape of the lunch box, with rounded corners to avoid stress concentration); Process parameters: Barrel temperature: 180℃ in the front section, 190℃ in the middle section, and 200℃ at the nozzle (to ensure the nucleating agent functions stably and induces uniform crystallization). Injection pressure: 60MPa (for lunchboxes with a wall thickness of 0.8-1.0mm, requiring rapid mold filling); Holding pressure: 40MPa, holding time: 10s; mold temperature: 30℃ (rapid cooling and shaping to ensure a smooth surface).
[0045] S4. Performance Verification (Adapted to Microwave Oven Usage Scenarios): Microwave heating test: Fill with 500mL of water and heat in a microwave oven on high for 5 minutes (center temperature 100℃), repeat 100 times; Key indicators: Haze ≤17% (initial 15%) after 100 heating cycles, no yellowing (Δb≤1.3), no odor (no decomposition of nucleating agent and antioxidant), and conforms to GB 4806.7-2016 standard for plastics for food contact.
[0046] Example 8: A process for using a high-temperature stable anti-reflection nucleating agent in the preparation of microwave oven food containers, comprising the following steps: S1. Raw material preparation: Basic raw material: food-grade copolymer polypropylene resin (melt index 3.0-3.5g / 10min, excellent impact resistance, preventing embrittlement after microwave heating); Nucleating agent: High-temperature stable anti-reflection nucleating agent prepared in Example 3 (addition amount 0.3%, balancing transparency and cost); Auxiliary raw materials: food-grade lubricant (0.1% ethylene bis-stearamide, which improves release properties and does not affect the dispersion of nucleating agents).
[0047] S2. Melt blending and granulation: Equipment: Twin-screw extruder (length-to-diameter ratio 36:1, conventional food-grade screw); Process parameters: Feeding section temperature: 160℃; Compression section temperature: 180℃; Homogenization section temperature: 200℃ (the nucleating agent has the best permeability enhancement effect at this temperature, and the antioxidant is not consumed prematurely). Screw speed: 300 r / min (moderate shear to ensure compatibility between nucleating agent and polypropylene); Granulation: Cut into pellets of 3mm length and dry to a moisture content of ≤0.1% (to avoid air bubbles during injection molding).
[0048] S3. Injection molding (Key points: thin-walled molding, smooth edges and corners): Equipment: Horizontal injection molding machine (cavity corresponds to the shape of the lunch box, with rounded corners to avoid stress concentration); Process parameters: Barrel temperature: 180℃ in the front section, 190℃ in the middle section, and 200℃ at the nozzle (to ensure the nucleating agent functions stably and induces uniform crystallization). Injection pressure: 70MPa (for lunchboxes with wall thickness of 0.8-1.0mm, requiring rapid mold filling); Holding pressure: 50MPa, holding time: 10-15s; mold temperature: 40℃ (rapid cooling and shaping to ensure a smooth surface).
[0049] S4. Performance Verification (Adapted to Microwave Oven Usage Scenarios): Microwave heating test: Fill with 500mL of water and heat in a microwave oven on high for 5 minutes (center temperature 120℃), repeat 100 times; Key indicators: Haze ≤17% (initial 15%) after 100 heating cycles, no yellowing (Δb≤1.3), no odor (no decomposition of nucleating agent and antioxidant), and conforms to GB 4806.7-2016 standard for plastics for food contact.
[0050] Example 9: A process for preparing transparent home appliance panels using a high-temperature stable antireflective nucleating agent, comprising the following steps: S1. Raw material preparation: Basic raw material: High-rigidity homopolymer polypropylene (flexural modulus ≥1800MPa, melt index 1.5-2.0g / 10min, to ensure panel strength). Nucleating agent: High-temperature stable antireflective nucleating agent prepared in Example 1 (addition amount 0.4%, which improves transparency and enhances rigidity); Auxiliary raw materials: anti-scratch agent (0.2% nano silica, particle size 50nm, which works synergistically with inorganic pigments in the nucleating agent and does not affect transparency).
[0051] S2. Extrusion molding (Key point: Flat sheet material, no warping): Equipment: Single screw extruder + sheet die (die width adapted to panel size, mirror-finish roller calendering); Process parameters: Extruder temperatures: feeding section 160℃, compression section 180℃, homogenization section 200℃ (the nucleating agent is stable at this temperature and melts uniformly with polypropylene); Die head temperature: 210℃ (to ensure melt flowability and uniform plate thickness); Roller parameters: calendering roller temperature 60℃, rotation speed 10m / min (slow cooling to promote nucleating agent-induced crystallization and reduce internal stress); Molded product: Polypropylene sheet (thickness 2.0-2.5mm, surface flatness ≤0.1mm / m).
[0052] S3. Post-processing and performance verification: Cutting: Cut to the size of the appliance panel, and polish the edges smooth (avoid burrs); Aging resistance test: placed in a 60℃ constant temperature oven for 1000 hours (simulating long-term use environment); Key indicators: initial haze ≤16%, haze after 1000h ≤17% (change ≤1%), no yellowing (Δb≤1.4), scratch resistance (pencil hardness ≥2H), and meets the standards for household appliance exterior parts.
[0053] Example 10: A process for preparing transparent home appliance panels using a high-temperature stable antireflective nucleating agent, comprising the following steps: S1. Raw material preparation: Basic raw material: High-rigidity homopolymer polypropylene (flexural modulus ≥1800MPa, melt index 1.5-2.0g / 10min, to ensure panel strength). Nucleating agent: High-temperature stable antireflective nucleating agent prepared in Example 3 (addition amount 0.5%, which improves transparency and enhances rigidity); Auxiliary raw materials: anti-scratch agent (0.2% nano silica, particle size 50nm, which works synergistically with inorganic pigments in the nucleating agent and does not affect transparency).
[0054] S2. Extrusion molding (Key point: Flat sheet material, no warping): Equipment: Single screw extruder + sheet die (die width adapted to panel size, mirror-finish roller calendering); Process parameters: Extruder temperatures: feeding section 160℃, compression section 180℃, homogenization section 210℃ (the nucleating agent is stable at this temperature and melts uniformly with polypropylene); Die head temperature: 210℃ (to ensure melt flowability and uniform plate thickness); Roller parameters: calendering roller temperature 70℃, rotation speed 15m / min (slow cooling to promote nucleating agent-induced crystallization and reduce internal stress); Molded product: Polypropylene sheet (thickness 2.0-2.5mm, surface flatness ≤0.1mm / m).
[0055] S3. Post-processing and performance verification: Cutting: Cut to the size of the appliance panel, and polish the edges smooth (avoid burrs); Aging resistance test: placed in a 60℃ constant temperature oven for 1000 hours (simulating long-term use environment); Key indicators: initial haze ≤16%, haze after 1000h ≤17% (change ≤1%), no yellowing (Δb≤1.4), scratch resistance (pencil hardness ≥2H), and meets the standards for household appliance exterior parts.
[0056] Analysis of commonalities and compatibility of processes: 1. Nucleating agent characteristics are compatible: The processing temperature of the three processes (190-220℃) is within the stable range of the nucleating agent (220-240℃), ensuring that it does not decompose and resists yellowing (synergistic effect of sodium alginate grafted cyclodextrin and antioxidant). 2. Performance-specific: 3. The manufacturing process of medical infusion bottles emphasizes "low volatility and sterilization resistance," with low nucleating agent migration (≤0.01%) and stable processing at 220℃; 4. The microwave oven food container manufacturing process emphasizes "stability under repeated heating," and the nucleating agent antioxidant system (1010+168) prevents degradation and odor. 5. The transparent appliance panel process focuses on "long-term temperature resistance". Stabilizing additives (aluminum hydroxyphosphate salt + magnesium sulfate whiskers) block oxygen penetration and ensure long-term stable haze.
[0057] Comparative Example 1: No sodium alginate grafted with cyclodextrin added (to verify its necessity for anti-yellowing). The difference from Example 1 is that sodium alginate grafted with cyclodextrin is omitted in step S2, while the other raw materials and preparation parameters are completely the same.
[0058] Preparation process: The raw materials contain only 500g of sorbitol nucleating agent, 10g of nano TiO2, 5g of phthalocyanine blue, 30g of stabilizing agent, and antioxidant (1010+1681:1), and do not contain sodium alginate grafted cyclodextrin. The premixing, main mixing, granulation and drying steps are the same as in Example 1.
[0059] Comparative Example 2: Replacing sodium alginate-grafted cyclodextrin with regular cyclodextrin (to verify the necessity of the grafting structure) The difference from Example 1 is that in step S2, "ordinary β-cyclodextrin" (grafting rate 0) is used instead of "sodium alginate grafted cyclodextrin", the amount added is the same (20g), and the other parameters are the same.
[0060] Comparative Example 3: No stabilizing agent added (to verify the heat stabilizing effect of the stabilizing agent). The difference from Example 1 is that the stabilizing agent (aluminum hydroxyphosphate salt + magnesium sulfate whiskers) is omitted in step S2, while the other raw materials and preparation parameters are the same.
[0061] Comparative Example 4: Replacing the compound antioxidant with a single antioxidant 1010 (to verify the necessity of the antioxidant compound). The difference from Example 1 is that in step S2, “1010+168 1:1 compound antioxidant” is replaced with “single antioxidant 1010”, the amount added is the same (20g), and the other parameters are the same.
[0062] Comparative Example 5: No Phthalocyanine Blue Added (to verify the light-modulating effect of organic pigments) The difference from Example 1 is that phthalocyanine blue is omitted in step S1, and only 10g of nano TiO2 is used as pigment, while the other raw materials and preparation parameters are the same.
[0063] Comparative Example 6: Millad-NX800 (commercially available nucleating agent) was used as a control (to verify overall performance advantages). Comparison: Commercially available Millad-NX800 was used directly, without employing the compounding system of this invention, and the addition amount was the same as in Example 1 (0.3% relative to the mass of polypropylene).
[0064] Comparative examples were used for process and performance testing in Examples 5, 7, and 9. (The nucleating agents prepared in the comparative examples were processed according to the application processes of Examples 5, 7, and 9, and the core performance indicators were tested.) Table 1. Performance data of the comparative example used in Example 5 (medical infusion bottle) Table 2. Performance data of the comparative example used in Example 5 (medical infusion bottle) Table 3. Performance data of the comparative example used in Example 7 (microwave oven food container) Table 4. Performance data of the comparative example used in Example 7 (microwave oven food container) Table 5. Performance data of the comparative example used in Example 9 (transparent appliance panel) Table 6. Performance data of the comparative example used in Example 9 (transparent appliance panel) Performance data analysis: 1. Verification of the role of core components: Sodium alginate grafted with cyclodextrin: The yellowness index Δb of Comparative Example 1 (without) and Comparative Example 2 (ordinary cyclodextrin) was significantly increased (Δb = 3.2 and 2.8 after sterilization, while it was only 1.0 in Example 1), proving that the grafted structure can inhibit yellowing through "anchoring + free radical capture", while ordinary cyclodextrin was ineffective due to migration (0.05 mg / kg of volatiles in Comparative Example 2); Stabilizing agent: Comparative Example 3 (without stabilizing agent) showed the most significant increase in haze (18.2% after sterilization and 20.0% after aging). Due to the lack of hydrolysis resistance of aluminum salt and oxygen barrier effect of whiskers, the nucleating agent is easily degraded at high temperature. Antioxidant compound: Comparative Example 4 (single 1010) has poor long-term stability (18.5% haze after 100 heating cycles), because the lack of 168 prevents the decomposition of hydroperoxides and the nucleating agent is consumed faster; Phthalocyanine blue: Comparative Example 5 (without phthalocyanine blue) showed an increase in initial haze (16.0%) and a slightly higher yellowness index (Δb=2.0 after sterilization), demonstrating its necessity in reducing visual yellowing through light compensation.
[0065] 2. Comparison with commercially available products (Comparison Example 6): The commercially available Millad-NX800 outperforms this invention in all scenarios: The haze after sterilization was 19.0% (only 15.5% in Example 1), due to the decomposition of the nucleating agent at high temperature; After 100 microwave heating cycles, there is a noticeable odor (benzaldehyde is released), but this invention has no odor. After 1000 hours of aging, the haze was 21.0% (Example 1: 15.8%), and severe yellowing (Δb=4.0) demonstrated the long-term stability advantage of the present invention.
[0066] 3. Application scenario adaptability: Medical infusion bottles: The low volatility (0.01 mg / kg) and low yellowing (Δb=1.0) of Example 1 meet the USP Class VI standard, while Comparative Examples 1-6 do not meet the standard; Microwaveable food container: After 100 heating cycles in Example 1, the haze changed by only 0.8%, with no odor, meeting food contact standards; Transparent appliance panel: After 1000h aging in Example 1, the haze change was ≤1% and the yellowing was slight, meeting the long-term appearance requirements.
[0067] in conclusion: The core components of this invention (sodium alginate grafted cyclodextrin, stabilizer, compound antioxidant, and phthalocyanine blue) work synergistically to improve high-temperature processing stability, anti-yellowing properties, and long-term transparency. The absence or replacement of any core component will lead to performance degradation. Compared with commercially available products, it has significant advantages in medical, food contact, and long-term use scenarios, verifying the inventiveness and practical value of the invention.
[0068] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.
[0069] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.
Claims
1. A high-temperature stable anti-penetration nucleating agent, characterized in that, The raw materials include the following parts by weight: 50-80 parts of sorbitol nucleating agent, 1-3 parts of inorganic pigment, 0.5-2 parts of organic pigment, 3-8 parts of stabilizing agent, 2-5 parts of sodium alginate grafted cyclodextrin, and 10-4 parts of antioxidant.
2. The high-temperature stable anti-reflection nucleating agent according to claim 1, characterized in that, The sorbitol nucleating agent is 1,3-di(3,4-dimethylbenzyl)sorbitol; The inorganic pigment is nano-titanium dioxide, and the particle size of the nano-titanium dioxide is 10-30 nm. The organic pigment is phthalocyanine blue.
3. The high-temperature stable anti-reflection nucleating agent according to claim 1, characterized in that, The stabilizing agent is obtained by compounding aluminum hydroxyphosphate salt and magnesium sulfate whiskers in a mass ratio of 1:1, and the aspect ratio of the magnesium sulfate whiskers is 20:
1. The grafting rate of the sodium alginate grafted with cyclodextrin is 15%-20%; The antioxidant is a compound of phenolic antioxidant 1010 and phosphite antioxidant 168 in a mass ratio of 1:
1.
4. A method for preparing a high-temperature stable anti-reflection nucleating agent, characterized in that, Includes the following steps: Step S1. Premixing: Add inorganic and organic pigments to a high-speed mixer and stir at 50-60℃ for 10-15 minutes to obtain pigment premix; Step S2. Main mixing: Add sorbitol nucleating agent and stabilizer to pigment premix, stir at 80-90℃ for 20-30 min, then add sodium alginate grafted cyclodextrin and antioxidant, reduce the speed to 1000 r / min, and continue stirring for 15-20 min to obtain the mixture. Step S3. Granulation and drying: The mixture is fed into a twin-screw granulator and granulated at 100-120℃. After granulation, it is dried in a vacuum drying oven at 80-90℃ for 4-6 hours to ensure that the moisture content is ≤0.1%. The mixture is then pulverized through an 80-100 mesh sieve to obtain a high-temperature stable permeability-enhancing nucleating agent.
5. The preparation method of the high-temperature stable anti-reflection nucleating agent according to claim 4, characterized in that, The high-speed mixer described in step S1 has a rotation speed of 1500 r / min and a heating rate of 2℃ / min for 50-60℃.
6. The method for preparing the high-temperature stable anti-reflection nucleating agent according to claim 4, characterized in that, The temperature of the twin-screw granulator in step S3 is controlled in stages: 80°C for the feeding stage, 100°C for the compression stage, and 110°C for the homogenization stage, to avoid premature consumption of antioxidants due to temperatures exceeding 120°C.
7. The application of a high-temperature stable anti-penetration nucleating agent, characterized in that, The high-temperature stable anti-reflective nucleating agent is used in medical infusion bottles, microwave oven food containers, and transparent appliance panels.
8. The application of the high-temperature stable anti-reflection nucleating agent according to claim 7, characterized in that, The high-temperature stable anti-reflection nucleating agent is added at a rate of 0.3%-0.4% when used in medical infusion bottles, with an injection molding temperature of 220℃ and a sterilization temperature of 121℃ / 20min.
9. The application of the high-temperature stable anti-reflection nucleating agent according to claim 7, characterized in that, The high-temperature stable anti-reflective nucleating agent is added at a rate of 0.2%-0.3% when used in microwave oven food containers, with an injection molding temperature of 200℃ and a service temperature of ≤140℃.
10. The application of the high-temperature stable anti-reflection nucleating agent according to claim 7, characterized in that, The high-temperature stable antireflective nucleating agent is added at a rate of 0.4%-0.5% when used in transparent home appliance panels, with an extrusion temperature of 210℃ and a long-term use temperature of 60℃.