Environment-friendly high-temperature-resistant PE bottle body and preparation method thereof

Abstract

The invention discloses an environment-friendly high-temperature-resistant PE bottle body and a preparation method thereof, and belongs to the technical field of packaging materials. The bottle body is of a three-layer co-extrusion structure, in the inner layer, high-density polyethylene serves as a base material, a graphene-nano-silicon dioxide core-shell filler and a dicumyl peroxide / triallyl isocyanurate cross-linking agent are added, and a high-temperature-resistant cross-linking layer is formed; the middle layer is a low-density polyethylene base material and is reinforced and toughened by silane-containing modified glass fibers; and the outer layer takes linear low-density polyethylene as a base material, is loaded with nano TiO and a starch-based biodegradable auxiliary agent, and is treated by trimethoxysilane to form a super-hydrophobic anti-aging layer. According to the preparation method, through microwave-assisted filler activation, ultrasonic online dispersion, gradient electron beam crosslinking and super-hydrophobic surface curing, the efficient dispersion of the filler and the synergistic effect of the functional layer are realized. And the prepared bottle body has excellent high temperature resistance, mechanical strength and environmental friendliness, and is suitable for high-temperature environment packaging application.

Description

Technical Field

[0001] The present invention relates to the technical field of packaging materials, and in particular to an environmentally friendly, high-temperature resistant PE bottle and a preparation method thereof. Background Art

[0002] Polyethylene (PE), a commonly used packaging material, offers excellent flexibility and processing properties, but suffers from insufficient high-temperature resistance (conventional PE has a heat deformation temperature of approximately 70-90°C). This makes it susceptible to deformation and release of harmful substances at high temperatures, limiting its application in scenarios such as high-temperature sterilization and long-term storage. Existing technologies improve high-temperature resistance by adding polypropylene (PP), inorganic fillers, or cross-linking modifications, but these technologies present the following challenges: Conflict between high temperature resistance and toughness: Although the traditional peroxide cross-linking process improves heat resistance, it increases the brittleness of the material and reduces the elongation at break by more than 30%; Poor filler dispersion: Nanofillers easily agglomerate and require high dosage (>20%) to be effective, increasing production costs and affecting environmental performance; Single function: Existing bottles cannot simultaneously meet the composite requirements of high temperature resistance, high barrier properties, and high strength. For example, pharmaceutical packaging requires temperature resistance above 120°C and low oxygen transmission rate (≤5cm³ / (m²・24h・0.1MPa)), which traditional PE packaging cannot meet.

[0003] Therefore, there is an urgent need to develop a PE bottle body and a preparation method thereof that has high temperature resistance, high toughness, environmental protection and multifunctional composite properties. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides an environmentally friendly, high-temperature resistant PE bottle designed through molecular-level cross-linking modification, nano-gradient enhancement and multifunctional interface layer design, which solves the problems of traditional PE packaging such as the contradiction between high-temperature resistance and toughness, low filler dispersion efficiency and single function, and also provides a supporting green preparation process.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: An environmentally friendly, high-temperature resistant PE bottle body, composed of 60%-80% polyolefin resin, 10%-25% high-temperature resistant reinforcing component, 5%-15% environmentally friendly functional filler, 2%-5% compatibilizer, 0.5%-1.5% antioxidant, and 0.3%-1% dynamic cross-linking agent; The bottle body is a multi-layer composite structure, including an inner layer, a middle layer and an outer layer, and the middle layer is provided with a polymer-based porous thermal insulation layer; the high-temperature resistant reinforcing component is polypropylene or its copolymer, including one or more of homopolymer polypropylene and copolymer polypropylene; the environmentally friendly functional filler comprises a composite system of nano-reinforcement material and surface-modified inorganic filler, wherein the nano-reinforcement material accounts for 20-40% of the total mass of the filler, and the nano-reinforcement material is lamellar inorganic nanoparticles; the dynamic cross-linking agent is a oligomer containing bismaleimide groups, and the reactive groups at both ends of its molecular chain form a temperature-responsive reversible cross-linking network with the polyolefin molecular chain; the polymer-based porous thermal insulation layer is a composite of thermoplastic resin and nano-scale porous thermal insulation particles, with a porosity of ≥90% and a thermal conductivity of ≤0.05W / (m·K).

[0006] Furthermore, the polyethylene in the polyolefin resin is high-density polyethylene, low-density polyethylene or a mixture of the two.

[0007] Furthermore, the surface-modified inorganic filler is one or more of talc, kaolin, montmorillonite, and diatomaceous earth; the surface modifier is a silane coupling agent or a titanate coupling agent; and the compatibilizer is a polyolefin-based compatibilizer, including one or more mixtures of ethylene-propylene copolymer, ethylene-acrylate copolymer, and maleic anhydride grafted polyolefin.

[0008] Furthermore, the antioxidant is a mixture of hindered phenols and phosphite antioxidants, with a mass ratio of 1:1-2:1; the total thickness of the multilayer composite structure is 1-3 mm, and the thickness ratio of the inner layer, middle layer and outer layer is 1:1:1-3:2:1.

[0009] Furthermore, under the action of the compatibilizer, the nano-reinforced material is dispersed in the matrix resin in a three-dimensional ordered intercalation structure, forming a gradient reinforcement network of resin-nanosheet-traditional filler, which increases the thermal deformation temperature of the material by 25-35°C and reduces the total filler usage by more than 30%.

[0010] Furthermore, the polymer-based porous insulation layer has both heat insulation and oxygen barrier properties, with an oxygen permeability of ≤5cm³ / (m²・24h・0.1MPa), meeting the requirements of high-barrier packaging.

[0011] A method for preparing an environmentally friendly, high-temperature-resistant PE bottle body comprises the following steps: raw material preparation, melt blending, multi-layer co-extrusion molding, cooling and shaping, and post-processing. The melt blending stage utilizes microwave-assisted dispersion technology, applying 2.45 GHz microwave radiation to the melting section of a twin-screw extruder to reduce the size of nanosheet material agglomerates to below 100 nm. The multi-layer co-extrusion molding stage simultaneously extrudes the polymer-based porous insulation layer raw material for the intermediate layer.

[0012] Furthermore, the raw material preparation includes treating the surface-modified inorganic filler and the nano-reinforced material with a coupling agent respectively, and ultrasonically dispersing the nano-reinforced material and the coupling agent in an ethanol or toluene solution at a mass ratio of 1:0.03-0.05 for 20-40 minutes.

[0013] Furthermore, the raw material of the polymer-based porous insulation layer is a mixture of ethylene-vinyl alcohol copolymer and silica aerogel, with a mass ratio of 70%-80%:20%-30%, and is synchronously formed into a four-layer or five-layer composite structure with the inner and outer layers through a co-extrusion die head.

[0014] Furthermore, the dynamic cross-linking agent undergoes a reversible cross-linking reaction with the polyolefin molecular chain during the melt blending process, forming a temperature-responsive network structure that is cross-linked at room temperature and de-cross-linked above 120°C, so that the bottle body maintains ≥80% of the room temperature tensile strength at 150°C.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention utilizes a dynamic crosslinker to create a temperature-responsive, reversible crosslinked network. Combining the gradient reinforcement effect of the nanosheet layer and traditional fillers with the thermal and oxygen barrier properties of the porous insulation layer, this allows the bottle to maintain at least 80% of its room-temperature tensile strength at 150°C, improve the heat deformation temperature by 25-35°C, and reduce the total filler content by over 30%. Simultaneously, it achieves the dual performance targets of a thermal conductivity of ≤0.05 W / (m・K) and an oxygen transmission rate of ≤5 cm³ / (m²・24h・0.1MPa), combining excellent high-temperature resistance, mechanical properties, environmental friendliness, and high barrier properties. The production process is environmentally friendly and efficient, making it suitable for large-scale industrial production. DETAILED DESCRIPTION

[0016] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] Example 1: Basic environmentally friendly and high-temperature resistant PE bottle 1. Raw material composition (mass percentage) Polyolefin resin: HDPE 65%, PP-R (copolymer polypropylene) 20% (high temperature resistant reinforcing component).

[0018] Environmentally friendly functional filler: 10% (nano-hydroxyapatite nanosheets 3%, surface-modified talc 7%).

[0019] Compatibilizer: EPR (ethylene-propylene copolymer) 3%.

[0020] Antioxidants: hindered phenol antioxidant (Irganox 1010) 0.5%, phosphite antioxidant (Irgafos 168) 0.5% (mass ratio 1:1).

[0021] Dynamic cross-linker: BMI-PEO (bismaleimide-polyethylene glycol oligomer) 0.8%.

[0022] 2. Key structural parameters Multi-layer composite structure: three-layer co-extrusion (inner layer: middle layer: outer layer = 2:1:2), total thickness 2mm.

[0023] Polymer-based porous insulation layer (middle layer): 80μm thick, made of EVOH (80%) + silica aerogel (20%), aerogel particle size 2-3μm, porosity 92%, thermal conductivity 0.045W / (m・K).

[0024] 3. Preparation method Raw material pretreatment Modification of nanohydroxyapatite nanosheets: 3 kg of nanosheets (80 nm thick) and 0.12 kg of silane coupling agent (KH-560) were added to 50 L of ethanol solution, ultrasonically dispersed for 30 min, and filtered and dried to obtain surface-modified nanosheets.

[0025] Talc modification: Add 7 kg of talc into a toluene solution containing 0.21 kg of titanate coupling agent, stir at 60 ° C for 40 min, and filter and dry.

[0026] melt blending Add the above raw materials into the twin-screw extruder, the screw speed is 250r / min, and the temperature is set as follows: Feeding section: 170℃.

[0027] Melting stage: 200°C (microwave assistance, frequency 2.45 GHz, power 8 kW).

[0028] Mixing section: 230℃.

[0029] Extrusion section: 240℃.

[0030] Scanning electron microscopy revealed that the size of the nanosheet aggregates was reduced to below 90 nm.

[0031] Multi-layer co-extrusion The blended pellets and the porous insulation layer raw materials were added to the three-layer co-extruder respectively. The molding temperature was 240℃ and the pressure was 100MPa. The inner layer (HDPE / PP-R base material), the middle layer (EVOH + aerogel), and the outer layer (same as the inner layer) were extruded simultaneously.

[0032] Cooling and shaping The formed blank was cooled in a cooling device at 30°C for 20 seconds and the finished bottle body was obtained after trimming.

[0033] 4. Performance Testing Heat deflection temperature (ASTM D648): 152°C (0.45MPa load).

[0034] Tensile strength (room temperature): 32MPa, 150℃ tensile strength retention rate 85%.

[0035] Oxygen transmission rate (GB / T 1038): 3.5cm³ / (m²·24h·0.1MPa).

[0036] Filler dispersion: The nanosheets are evenly intercalated in the matrix, and the proportion of agglomerates is less than 5%.

[0037] Example 2: PE bottle for high barrier pharmaceutical packaging 1. Raw material composition (mass percentage) Polyolefin resin: LDPE 60%, PP-B (block copolymer polypropylene) 25% (high temperature resistant reinforcing component).

[0038] Environmentally friendly functional filler: 8% (graphene nanosheets 3.2%, surface modified kaolin 4.8%).

[0039] Compatibilizer: EAA (ethylene-acrylate copolymer) 4%.

[0040] Antioxidants: hindered phenols 0.8%, phosphites 0.5% (mass ratio 1.6:1).

[0041] Dynamic cross-linker: BMI-PEO 0.7%.

[0042] 2. Key structural parameters Multi-layer composite structure: five-layer co-extrusion (inner layer: functional layer: middle layer: functional layer: outer layer = 1:1:2:1:1), total thickness 2.5mm.

[0043] Polymer-based porous insulation layer (middle layer): thickness 90μm, EVOH (75%) + silica aerogel (25%), oxygen permeability 2.8cm³ / (m²・24h・0.1MPa).

[0044] 3. Key Adjustments to Preparation Methods Nanographene modification: Graphene nanosheets (thickness 60 nm) and coupling agent (KH-570) were ultrasonically dispersed at a ratio of 1:0.05 for 40 min.

[0045] Co-extrusion molding: Add functional layers on both sides (including antioxidant-enriched layers), molding temperature 230°C, pressure 110 MPa.

[0046] Cooling and shaping: Cooling at 25℃ for 25 seconds to improve dimensional accuracy.

[0047] 4. Performance Testing Thermal stability (TGA): 5% weight loss temperature is 320℃, 50℃ higher than traditional PE bottles.

[0048] Oxygen barrier performance: Meets the high-barrier packaging requirements of the 2025 edition of the Chinese Pharmacopoeia (oxygen transmission rate ≤ 5cm³ / (m²・24h・0.1MPa)).

[0049] High temperature cycle test: After 500 cycles at 130°C / 30min, the bottle showed no deformation and the extractable matter test complies with GB4806.7-2016.

[0050] Example 3: PE bottle for lightweight food packaging 1. Raw material composition (mass percentage) Polyolefin resin: HDPE / LDPE (7:3) 70%, PP-H (homopolymer polypropylene) 15% (high temperature resistant reinforcing component).

[0051] Environmentally friendly functional filler: 9% (nano-montmorillonite flakes 3.6%, surface-modified diatomaceous earth 5.4%).

[0052] Compatibilizer: PE-g-MAH (maleic anhydride grafted polyethylene) 3%.

[0053] Dynamic cross-linker: BMI-PEO 0.6%.

[0054] Antioxidants: hindered phenols 0.3%, phosphites 0.1% (mass ratio 3:1).

[0055] 2. Key structural parameters Multi-layer composite structure: four-layer co-extrusion (inner layer: porous layer: reinforcement layer: outer layer = 1:1:1:1), total thickness 1.5mm.

[0056] Polymer-based porous insulation layer: 50μm thickness, EVOH (80%) + aerogel (20%), density 0.92g / cm³, 15% lighter than traditional PE bottles.

[0057] 3. Key Adjustments to Preparation Methods Microwave-assisted parameters: microwave power in the melting section is 5kW, and screw speed is 300r / min to improve dispersion efficiency.

[0058] Co-extrusion die head: adopts lightweight design, the outer layer thickness is reduced by 20% while maintaining mechanical properties.

[0059] 4. Performance Testing Mechanical properties: tensile strength 26MPa, elongation at break 350% (room temperature), impact strength at 120℃ 15kJ / m².

[0060] High temperature and weather resistance: After 1000h of QUV aging, the tensile strength retention rate is 90% and there is no obvious discoloration.

[0061] Environmental protection: The total amount of filler is reduced by 33% compared with the traditional solution. The discarded bottles can be physically recycled and granulated, with a recovery rate of ≥95%.

[0062] Comparative Example: Traditional PP / PE blended bottle (not containing the core technology of this invention) 1. Raw material composition (mass percentage) HDPE 70%, PP 20%, unmodified talc 10%, compatibilizer 3%.

[0063] 2. Performance Comparison Heat deformation temperature: 120°C (32°C lower than Example 1).

[0064] Tensile strength (150°C): retention rate 60% (85% in Example 1).

[0065] Oxygen transmission rate: 18cm³ / (m²・24h・0.1MPa) (does not meet high barrier requirements).

[0066] Filler dispersion: The size of talc powder agglomerates is greater than 500nm, and the toughness of the material is significantly reduced (elongation at break 200%).

[0067] By incorporating BMI-PEO, Examples 1-3 all achieved a balance of "high strength at room temperature and flexibility at high temperatures," with a tensile strength retention of ≥80% at 150°C, addressing the brittleness of traditional cross-linked materials. A composite ratio of 20-40% nanosheets (50-100nm) and traditional fillers reduced total filler usage by over 30%, while simultaneously increasing heat deformation temperature by more than double that of a single filler system. The EVOH / aerogel composite structure, in Example 2, achieved an oxygen transmission rate of ≤5 cm³ / (m²・24h・0.1MPa), meeting the high-barrier requirements for specialized packaging such as vaccines and targeted drugs, filling a technological gap in existing PE packaging.

[0068] This invention provides an environmentally friendly, high-temperature-resistant PE bottle and its preparation method. The bottle's raw materials include 60%-80% polyolefin resin, specifically polyethylene, polypropylene, or their copolymers; 5%-15% environmentally friendly functional filler, consisting of 20-40% nanosheet materials such as hydroxyapatite nanosheets and graphene nanosheets and surface-modified inorganic fillers; 0.3%-1% BMI-PEO, a dynamic crosslinker containing bismaleimide groups; as well as compatibilizers and antioxidants. The bottle adopts a multilayer composite structure of inner layer / middle layer / outer layer, with a 50-100μm thick porous insulation layer of EVOH and silica aerogel in the middle layer. Microwave-assisted dispersion technology is used to achieve efficient dispersion of the nanofiller, and the bottle is produced through melt blending and multilayer co-extrusion molding. This solution utilizes a dynamic crosslinker to create a temperature-responsive, reversible crosslinked network. Combining the gradient reinforcement effect of nanosheets and traditional fillers with the thermal and oxygen barrier properties of a porous insulation layer, this solution maintains at least 80% of its room-temperature tensile strength at 150°C, increases heat distortion temperature by 25-35°C, and reduces total filler usage by over 30%. It also achieves the dual performance targets of a thermal conductivity of ≤0.05W / (m・K) and an oxygen transmission rate of ≤5cm³ / (m²・24h・0.1MPa), combining excellent high-temperature resistance, mechanical properties, environmental friendliness, and high barrier properties. The efficient and environmentally friendly manufacturing process makes it suitable for large-scale industrial production.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0070] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An environmentally friendly, high-temperature resistant PE bottle, characterized by: It is composed of 60%-80% polyolefin resin, 10%-25% high temperature resistant reinforcing component, 5%-15% environmentally friendly functional filler, 2%-5% compatibilizer, 0.5%-1.5% antioxidant, and 0.3%-1% dynamic cross-linking agent; The bottle body is a multi-layer composite structure, including an inner layer, a middle layer and an outer layer, and the middle layer is provided with a polymer-based porous thermal insulation layer; the high-temperature resistant reinforcing component is polypropylene or its copolymer, including one or more of homopolymer polypropylene and copolymer polypropylene; the environmentally friendly functional filler comprises a composite system of nano-reinforcement material and surface-modified inorganic filler, wherein the nano-reinforcement material accounts for 20-40% of the total mass of the filler, and the nano-reinforcement material is lamellar inorganic nanoparticles; the dynamic cross-linking agent is a oligomer containing bismaleimide groups, and the reactive groups at both ends of its molecular chain form a temperature-responsive reversible cross-linking network with the polyolefin molecular chain; the polymer-based porous thermal insulation layer is a composite of thermoplastic resin and nano-scale porous thermal insulation particles, with a porosity of ≥90% and a thermal conductivity of ≤0.05W / (m·K).

2. The environmentally friendly, high-temperature resistant PE bottle according to claim 1, characterized in that: The polyethylene in the polyolefin resin is high-density polyethylene, low-density polyethylene or a mixture of the two.

3. The environmentally friendly, high-temperature resistant PE bottle according to claim 1, characterized in that: The surface-modified inorganic filler is one or more of talc, kaolin, montmorillonite, and diatomaceous earth; the surface modifier is a silane coupling agent or a titanate coupling agent; and the compatibilizer is a polyolefin-based compatibilizer, including one or more mixtures of ethylene-propylene copolymer, ethylene-acrylate copolymer, and maleic anhydride-grafted polyolefin.

4. The environmentally friendly, high-temperature resistant PE bottle according to claim 1, characterized in that: The antioxidant is a mixture of hindered phenols and phosphite antioxidants, with a mass ratio of 1:1-2:1; the total thickness of the multi-layer composite structure is 1-3 mm, and the thickness ratio of the inner layer, the middle layer and the outer layer is 1:1:1-3:2:

1.

5. The environmentally friendly, high-temperature resistant PE bottle according to claim 1, characterized in that: Under the action of the compatibilizer, the nano-reinforced material is dispersed in the matrix resin in a three-dimensional ordered intercalation structure, forming a gradient reinforcement network of resin-nanosheet-traditional filler, which increases the thermal deformation temperature of the material by 25-35°C and reduces the total filler usage by more than 30%.

6. The environmentally friendly, high-temperature resistant PE bottle according to claim 1, characterized in that: The polymer-based porous insulation layer has both heat insulation and oxygen barrier properties, with an oxygen permeability of ≤5cm³ / (m²・24h・0.1MPa), meeting the requirements of high-barrier packaging.

7. A method for preparing an environmentally friendly, high-temperature resistant PE bottle according to any one of claims 1 to 6, characterized in that: include: The process includes raw material preparation, melt blending, multi-layer co-extrusion molding, cooling and shaping, and post-processing steps; the melt blending stage uses microwave-assisted dispersion technology, and 2.45GHz microwave radiation is applied to the melting section of the twin-screw extruder to reduce the size of the nanosheet material agglomerates to below 100nm; the multi-layer co-extrusion molding stage simultaneously extrudes the polymer-based porous insulation layer raw materials of the intermediate layer.

8. The preparation method according to claim 7, characterized in that: The raw material preparation comprises treating the surface-modified inorganic filler and the nano-reinforced material with a coupling agent respectively, and ultrasonically dispersing the nano-reinforced material and the coupling agent in an ethanol or toluene solution at a mass ratio of 1:0.03-0.05 for 20-40 minutes.

9. The preparation method according to claim 7, characterized in that: The raw material of the polymer-based porous insulation layer is a mixture of ethylene-vinyl alcohol copolymer and silica aerogel, with a mass ratio of 70%-80%:20%-30%. It is formed into a four-layer or five-layer composite structure synchronously with the inner and outer layers through a co-extrusion die head.

10. The preparation method according to claim 7, characterized in that: The dynamic cross-linking agent undergoes a reversible cross-linking reaction with the polyolefin molecular chain during the melt blending process, forming a temperature-responsive network structure that is cross-linked at room temperature and de-cross-linked above 120°C, so that the bottle body maintains ≥80% of the room temperature tensile strength at 150°C.