Light-blocking packaging article and method for producing the same

Abstract

The application provides a light-blocking packaging product and a preparation method and application thereof. The light-blocking packaging product comprises, in parts by weight, 80-99.7 parts of a base resin, 0.1-12 parts of a first polymer and 0.2-12 parts of titanium white powder; the first polymer comprises at least two incompatible polyolefins; and the mass percentage of the titanium white powder in the light-blocking packaging product is less than 10%. In the application, the light-blocking packaging product can not only improve the light-blocking rate and ensure the high whiteness of the light-blocking packaging product, but also can reduce the content of the titanium white powder in the light-blocking packaging product and reduce the risk of migration of the titanium white powder to food.

Description

Technical Field

[0001] This invention belongs to the field of packaging materials technology, specifically relating to a light-blocking packaging product and its preparation method. Background Technology

[0002] In dairy product packaging, including milk beverages and yogurt products, light protection is a crucial factor to consider. Light has a significant impact on dairy products; it can damage nutrients in milk and stimulate the production of free radicals, accelerating oxidation and spoilage. The most common reaction in milk under light is the photo-induced oxidation of cysteine, which produces sulfides such as thiols and dimethyl sulfide. These substances severely affect the taste and nutritional value of milk. Furthermore, many nutrients in milk, such as vitamin A, vitamin B2 (riboflavin), vitamin D, and amino acids, are also lost due to light exposure.

[0003] Currently, many dairy products are packaged and sold using cold chain methods. However, factors such as short shelf life, high warehousing and transportation costs, and a narrow sales radius severely impact sales scope and volume. Some dairy companies use Tetra Pak paper-plastic packaging for room temperature sales after high-temperature sterilization, extending the shelf life to six months or even nine months and expanding sales nationwide. However, Tetra Pak packaging has drawbacks, including high equipment investment, limited packaging specifications, inability to reseal once opened, and difficulty in recycling. Therefore, room-temperature plastic packaging is increasingly favored by dairy companies and consumers, with polyester plastic packaging being the most popular. Polyester packaging has unique advantages, such as diverse bottle designs, high production efficiency, and interchangeable injection molding equipment, avoiding redundant investment. However, polyester plastic packaging has high light transmittance, which contradicts the high light-blocking requirements of dairy products. Therefore, it is necessary to add high light-blocking materials (ideally with a light-blocking rate of 99.9% or higher) to improve the light-blocking performance of polyester packaging bottles, thereby protecting dairy product quality and extending shelf life.

[0004] Among the mainstream high light-blocking materials on the market, titanium dioxide is commonly used due to its high whiteness and high reflectivity. The content of titanium dioxide is typically 6% to 8%. However, the light-blocking rate achievable by adding titanium dioxide alone is limited and cannot meet the high light-blocking requirements of dairy product packaging. Furthermore, titanium dioxide poses safety risks; therefore, its content or proportion used in food packaging needs to be carefully controlled to minimize the risk of it migrating into food and beverages. In addition, carbon black is sometimes added in combination with titanium dioxide to improve light absorption and achieve high light-blocking performance. However, the introduction of carbon black reduces the overall whiteness of the bottle, resulting in a dull appearance that lowers the packaging's quality and aesthetics. Although the bottle is usually completely covered by a label, the bottle opening is still exposed after opening, affecting the consumer's sensory experience.

[0005] Therefore, developing a packaging product with high light-blocking properties, high whiteness, and low titanium dioxide content is an urgent problem to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a light-blocking packaging product and its preparation method. The light-blocking packaging product solves the problems of existing dairy product packaging materials not being able to simultaneously achieve high light blocking and high whiteness, as well as the potential migration risks caused by high titanium dioxide content.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a light-blocking packaging article, wherein, by weight, the light-blocking packaging article comprises 80 to 99.7 parts of a base resin, 0.1 to 12 parts of a first polymer and 0.2 to 12 parts of titanium dioxide; the first polymer comprises at least two incompatible polyolefins; and the mass percentage of titanium dioxide in the light-blocking packaging article is <10%.

[0009] In this invention, by adding at least two incompatible polyolefins to the base resin, due to the differences in compatibility and thermodynamic properties between the different polymers, a significant interfacial effect occurs between them and the polyester resin, forming an island structure in the polyester matrix. After subsequent stretching processing, the first polymer forms a disc-shaped morphology with a certain aspect ratio, partially embedding itself in the pores formed by stretching the polyester matrix, forming a large number of irregular multiphase interfaces. When light passes through these interfaces, it is continuously scattered, reflected, and refracted, reducing the light transmittance and thus achieving a light-blocking effect. By adding a first polymer with a specific composition and content, not only can the light-blocking rate be improved, but also the high whiteness of the packaging product can be guaranteed without the need to add materials such as carbon black. At the same time, the content of titanium dioxide in the packaging product can be reduced, minimizing the risk of titanium dioxide migrating into food.

[0010] In this invention, 80 to 99.7 parts of polyester resin can be, for example, 80 parts, 82 parts, 84 parts, 86 parts, 88 parts, 90 parts, 92 parts, 94 parts, 95 parts, 96 parts, 97 parts, 98 parts, 99 parts, etc.

[0011] In this invention, 0.1 to 12 parts of the first polymer can be, for example, 0.1 parts, 0.5 parts, 1 part, 2 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, etc.

[0012] In this invention, 0.2 to 12 parts of titanium dioxide can be, for example, 0.2 parts, 0.5 parts, 0.8 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts, 11.5 parts, 12 parts, etc.

[0013] In this invention, the mass percentage of titanium dioxide in the light-blocking packaging product is <10%, for example, it can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc., preferably the mass percentage of titanium dioxide in the light-blocking packaging product is ≤8%, and more preferably the mass percentage of titanium dioxide in the light-blocking packaging product is ≤4%.

[0014] In this invention, the mass percentage of the first polymer in the light-blocking packaging product is ≥3%, preferably ≥5%, and more preferably 5.5-9.5%.

[0015] Preferably, the first polymer comprises at least one alicyclic polyolefin and at least one aliphatic polyolefin.

[0016] Preferably, the alicyclic polyolefin includes cyclic olefin polymers; the aliphatic polyolefin includes poly4-methyl-1-pentene.

[0017] Cyclic olefin polymers are amorphous, transparent polymers that are both lightweight and transparent, making them a preferred material for optical lenses and various screen films. Their molecular backbone contains a large aliphatic cyclic structure, resulting in an amorphous shape and a high glass transition temperature. They also possess characteristics such as low water absorption, high rigidity, high heat resistance, and good water vapor tightness. Furthermore, they comply with food safety standards such as the US FDA, European EU, Japanese Pharmacopoeia, and ISO 10993. In recent years, they have gradually become a high-end material replacing glass and other plastics, and are widely used in pre-filled syringes, infusion bags, contrast agents, hyaluronic acid packaging bottles, and other medical, pharmaceutical, and cosmetic fields.

[0018] Poly(4-methyl-1-pentene), also known as polymethylpentene, is abbreviated as PMP and has the chemical formula (C6H4O). 12 ) n The structural formula is Its synthesis process includes: dimerizing propylene to obtain 4-methyl-1-pentene; then polymerizing 4-methyl-1-pentene to obtain poly4-methyl-1-pentene. Poly4-methyl-1-pentene is a low-density thermoplastic resin, appearing as a colorless, transparent granular solid with a density of 0.835 g / cm³.3 It exhibits excellent heat resistance, with a melting point of 240℃, visible light transmittance of up to 90%, and ultraviolet light transmittance superior to glass and other transparent resins. It also possesses outstanding electrical insulation and chemical resistance. Due to its safety and non-toxicity, polymethylpentene is widely used in medical devices (such as syringes), physical and chemical laboratory equipment, tableware for electronic cooktops, baking trays, and other fields.

[0019] In this invention, due to differences in compatibility and thermodynamic properties between different polymers, cyclic olefin polymers and poly4-methyl-1-pentene exhibit significant interfacial effects with the base resin, forming island structures within the base resin. After subsequent stretching, the first polymer forms a disc-like shape with a certain aspect ratio, partially embedding itself in the pores formed by stretching the base resin, creating numerous irregular multiphase interfaces. When light passes through these interfaces, it undergoes continuous scattering, reflection, and refraction, reducing light transmittance and thus achieving a light-blocking effect. The use of cyclic olefin polymers and poly4-methyl-1-pentene not only improves the light-blocking rate of the packaging product but also eliminates the need for materials such as carbon black, ensuring high whiteness of the packaging product. Simultaneously, it reduces the titanium dioxide content in the packaging product, minimizing the risk of titanium dioxide migrating into food.

[0020] Preferably, the mass ratio of the alicyclic polyolefin to the aliphatic polyolefin is (0.4–4.5):1, wherein the specific values ​​of (0.4–4.5) can be, for example, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, etc.; preferably (1.5–4):1.

[0021] In this invention, alicyclic polyolefins and aliphatic polyolefins are compounded in a specific mass ratio, which can adjust the microstructure of the first polymer in the base resin (wherein the base resin is the continuous phase and the first polymer is the barrier phase). After subsequent stretching processing, the barrier cake formed by the first polymer is shorter, thinner, and smaller in size. The smaller barrier cake is embedded in the pores formed by stretching the base resin, which can create more phase interfaces, further enhancing the reflection, scattering, and refraction of light at the interface, thereby further enhancing the light blocking property. The mechanism is not yet clear, but it is speculated that the compounding of alicyclic polyolefins and aliphatic polyolefins in a specific mass ratio can adjust the viscosity of the dispersed phase, resulting in a change in the interfacial strength, thereby changing the morphology of the dispersed phase in the base resin. This is a novel research discovery of this invention.

[0022] Preferably, the cyclic olefin polymers include olefin-cyclic olefin copolymers and / or cyclic olefin polymers.

[0023] An olefin-cyclic olefin copolymer, abbreviated as COC, is a copolymer formed by copolymerizing olefins and cyclic olefins. In COC, the olefin includes ethylene, and the cyclic olefin includes norbornene. For example, the structural formula of the copolymer formed by ethylene and norbornene is... It is obtained by polymerization of ethylene and norbornene; wherein, norbornene can be prepared by DA reaction of ethylene and cyclopentadiene (or dicyclopentadiene); the cyclic olefin polymer, abbreviated as COP, is formed by the monomer polymerization of cyclic olefin monomers; in the COP, the cyclic olefin includes norbornene; exemplary, the structural formula of the polymer formed by the norbornene is as follows:

[0024] Preferably, the titanium dioxide includes rutile titanium dioxide.

[0025] Rutile titanium dioxide has a special ionic crystal structure and a high refractive index (about 2.7), which gives it excellent hiding power and opacity. It also has excellent chemical stability, weather resistance, light resistance and heat resistance. To ensure the high light blocking rate and high whiteness of the light blocking masterbatch, while minimizing the amount of titanium dioxide used, rutile titanium dioxide is preferred.

[0026] Preferably, the substrate resin and the first polymer form an island structure, wherein the substrate resin constitutes a continuous phase and the first polymer constitutes a dispersed phase.

[0027] Preferably, the dispersed phase of the first polymer is a cake-shaped barrier phase.

[0028] Preferably, the average diameter of the disc-shaped barrier phase is 0.5–40 μm, for example, it can be 0.5 μm, 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, 12 μm, 14 μm, 16 μm, 18 μm, 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, 32 μm, 35 μm, 38 μm, 40 μm, etc.; more preferably, it is 1–20 μm, or even better. Preferably, the thickness is 2–10 μm, particularly preferably 2.5–5 μm; the average thickness is 0.05–10 μm, for example, it can be 0.05 μm, 0.1 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, etc.; preferably 0.1–5 μm, more preferably 0.2–3 μm, and particularly preferably 0.5–2 μm.

[0029] Preferably, the aspect ratio of the average diameter to the average thickness of the disc-shaped barrier phase is 1.2 to 100, for example, it can be 1.2, 5, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68, 70, 72, 75, 78, 80, 82, 85, 88, 90, 92, 95, 98, 100, etc.; more preferably, it is 1.5 to 50, more preferably, it is 2 to 20, and particularly preferably, it is 2.5 to 8.

[0030] Preferably, by weight, the light-blocking packaging product further includes 0.02 to 6 parts of inorganic filler (e.g., 0.02, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, etc.) and / or 0.0002 to 1 part of metallic pigment (e.g., 0.0002, 0.0004, 0.0008, 0.001, 0.005, 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 0.8, 1, etc.).

[0031] Preferably, the inorganic filler has a mesh size of 40 to 30,000 mesh, for example, 40 mesh, 60 mesh, 80 mesh, 100 mesh, 200 mesh, 400 mesh, 600 mesh, 800 mesh, 1000 mesh, 1200 mesh, 1500 mesh, 1800 mesh, 2000 mesh, 2200 mesh, 2500 mesh, 2800 mesh, 3000 mesh, 3500 mesh, 4000 mesh, 5000 mesh, 6000 mesh, 8000 mesh, 10000 mesh, 15000 mesh, 20000 mesh, 25000 mesh, 30000 mesh, etc.; more preferably, 100 to 10000 mesh, more preferably 500 to 5000 mesh, and particularly preferably 1000 to 3000 mesh.

[0032] Preferably, the inorganic filler includes at least one of calcined kaolin, calcite powder, silica powder, zinc oxide, barium sulfate, zinc sulfide, or calcium carbonate, more preferably barium sulfate and / or zinc oxide.

[0033] Preferably, the average particle size of the metallic pigment is 1–100 μm, for example, it can be 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, etc., more preferably 2–50 μm, more preferably 5–35 μm, and particularly preferably 10–20 μm.

[0034] Preferably, the metallic pigment includes at least one of elemental metal, metal oxide, or metal alloy, and more preferably elemental metal and / or metal oxide.

[0035] Preferably, the metal in the metallic pigment includes at least one of aluminum, iron, zinc, copper, or silver, more preferably aluminum.

[0036] In this invention, inorganic fillers and metallic pigments can play a steric hindrance role; by adding a specific amount of inorganic fillers and / or metallic pigments, the light blocking performance can be further improved, and the titanium dioxide content can be reduced while ensuring that the whiteness of the packaged product is not affected.

[0037] Preferably, the light-blocking packaging product further includes 0.0002 to 1 part compatibilizer by weight, for example, 0.0002 parts, 0.0004 parts, 0.0008 parts, 0.001 parts, 0.005 parts, 0.01 parts, 0.02 parts, 0.05 parts, 0.1 parts, 0.2 parts, 0.5 parts, 0.8 parts, 1 part, etc.

[0038] Preferably, the compatibilizer includes at least one of maleic anhydride-grafted polyethylene (PE-g-MAH), maleic anhydride-grafted polypropylene (PP-g-MAH), maleic anhydride-grafted polyolefin elastomer (POE-g-MAH), or glycidyl methacrylate-grafted polyolefin elastomer (PE-g-GMA).

[0039] To avoid problems such as product delamination or decreased mechanical properties due to poor compatibility, it is preferable to add a specific amount of compatibilizer without affecting the light blocking performance.

[0040] Preferably, the light-blocking packaging product further includes 0.0002 to 4 parts of other additives by weight, such as 0.0002 parts, 0.0004 parts, 0.0008 parts, 0.001 parts, 0.005 parts, 0.01 parts, 0.05 parts, 0.1 parts, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, etc.

[0041] Preferably, the other additives include at least one of dispersants, lubricants, antioxidants, heat absorbers, light stabilizers, antistatic agents, or colorants.

[0042] In this invention, other additives may be added as needed, not limited to the aforementioned additives. For example, to facilitate the processing and production of the product and improve dispersibility and processing performance, dispersants and / or lubricants may be added. These dispersants and / or lubricants include, but are not limited to, polyethylene wax, ethylene-vinyl acetate wax, monopolyester wax, glyceryl stearate (GMS), stearates (such as calcium stearate, magnesium stearate, zinc stearate, etc.), amide waxes (such as vinyl bis-stearamide EBS, erucamide, oleamide, etc.), pentaerythritol stearate (PETS), etc. Furthermore, the introduction of specific types of waxes will also have a positive impact on light-blocking properties.

[0043] To improve the quality and stability of packaging materials and contents, antioxidants can be added, including but not limited to high molecular weight hindered phenolic antioxidants and solid organic phosphite antioxidants; to improve the material's reheating performance, endothermic agents can be added, including but not limited to carbon black, tungsten oxide, activated carbon, titanium nitride, and zinc nitride; to improve the material's light stability, light stabilizers can be added, including but not limited to UV234, UV1577, UV1164, UV360, and UV3638; to improve the material's antistatic properties, antistatic agents can be added, including but not limited to cationic surfactants and anionic surfactants.

[0044] In this invention, pigments or organic dyes can be added as needed to improve whiteness or to present a colored light-blocking effect. The colorants include, but are not limited to, at least one of Phthalocyanine Blue BGS, Transparent Blue 2B, Ultramarine Blue, Transparent Violet B, Phthalocyanine Violet, Yellow Pigment 180, Dye Yellow 6G, Dye Red 5B, Iron Oxide Red, and Solvent Red 454.

[0045] Preferably, the substrate resin includes at least one of polystyrene, polyacrylonitrile, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene copolymer, polymethyl methacrylate, polyamide, polyester, polycarbonate, polypropylene carbonate, polyamino acid, cellulose, thermoplastic starch, polyvinyl alcohol, chitosan, polyhydroxyalkanoate, or thermoplastic elastomer; more preferably, it is at least one of polyester, polycarbonate, polypropylene carbonate, polyamino acid, cellulose, thermoplastic starch, polyvinyl alcohol, chitosan, polyhydroxyalkanoate, or thermoplastic elastomer.

[0046] Preferably, the polyester comprises at least one of polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG), diacid-modified polyethylene terephthalate, polycyclohexanediol terephthalate (PCT), glycol-modified polycyclohexanediol terephthalate (PCTG), diacid-modified polycyclohexanediol terephthalate, a copolyester of cyclohexanediol and terephthalic acid (PCTA), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polylactide (PLA), polyhydroxyalkanoates (PHA), polybutylene adipate / terephthalate (PBAT), polybutylene succinate (PBS), polybutylene adipate succinate (PBSA), polycaprolactone (PCL), amorphous copolyesters, or polyarylates.

[0047] Preferably, the thermoplastic elastomer comprises at least one of styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-ethylene-butene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene copolymer (SEPS), thermoplastic olefin (TPO), thermoplastic vulcanizate (TPV), thermoplastic polybutadiene (TPB), thermoplastic polyisoprene (TPI), thermoplastic polyvinyl chloride (TPVC), thermoplastic chlorinated polyethylene (TCPE), thermoplastic polyurethane elastomer (TPU), thermoplastic polyester elastomer (TPEE), thermoplastic polyamide elastomer (TPAE), thermoplastic fluoride (TPF), or thermoplastic vulcanizate silicone (TPSiV).

[0048] Most preferably, the substrate resin is at least one of polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG), polylactide (PLA), polyhydroxyalkanoate (PHA), amorphous copolyester, or polyarylate.

[0049] Preferably, the light-blocking packaging product includes at least one of extrusion blow molding, injection molding, injection blow molding, compression molding, blister molding, or injection stretch blow molding; preferably, it is an injection stretch blow molding product.

[0050] Preferably, the light-blocking packaging product includes a light-blocking bottle.

[0051] Preferably, the light-blocking packaging product meets the following conditions.

[0052] (1) The whiteness of the light-blocking packaging product is 80 to 100, for example, it can be 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, etc.; and (2) the light transmittance of the light-blocking packaging product in the 550nm band is 0 to 2%, for example, it can be 0%, 0.02%, 0.04%, 0.06%, 0.08%, 0.1%, 0.2%, 0.3%, 0.4%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, etc.

[0053] In a second aspect, the present invention provides a method for preparing a light-blocking packaging article according to the first aspect, the method comprising:

[0054] A formulation is formed by mixing 80-99.7 parts of base resin, 0.1-12 parts of first polymer, 0.2-12 parts of titanium dioxide, and optionally 0.02-6 parts of inorganic filler, 0.0002-1 part of metallic pigment, 0.0002-1 part of compatibilizer, and 0.0002-4 parts of other additives, and is used to mold the light-blocking packaging product.

[0055] In this invention, the components in the formula are directly added to the equipment for processing and molding, or they are first extruded and granulated together with at least one other component, and the resulting particles are then added to the equipment for processing and molding, or the resulting particles are directly added to the equipment together with other formula components for processing and molding.

[0056] Preferably, the extrusion granulation temperature is 250-300℃, for example, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, etc.

[0057] In this invention, the extrusion granulation is carried out in a twin-screw extruder; the process parameters of the twin-screw extruder are as follows: feed temperature zone: 260-300℃; equilibrium temperature zone: 260-290℃; discharge temperature zone: 250-280℃; side feeding zone is the equilibrium temperature zone: 250-270℃; the vacuum zone controls the vacuum degree to be 0.3-1MPa; the extrusion zone temperature: 250-270℃; after extrusion, the material is cooled, air-dried, pelletized, separated, and dried to obtain the light-blocking masterbatch; wherein, the pelletizer speed is 700-1000 r / min.

[0058] In this invention, the cooling includes air cooling or water cooling.

[0059] Preferably, the molding method includes first molding the formula to obtain a preform or preform; and then second molding the preform or preform to obtain the light-blocking packaging product.

[0060] Preferably, the first molding method includes at least one of extrusion molding, injection molding, or compression molding.

[0061] Preferably, the second molding method includes blow molding and / or vacuum molding.

[0062] Preferably, the molding method includes extruding and granulating the formula, injection molding to obtain a preform or preform; and then blow molding the preform or preform to obtain the light-blocking packaging product.

[0063] Preferably, the injection molding and blow molding include a two-step method and / or a one-step method.

[0064] Preferably, the extrusion temperature is 250–300°C, for example, 250°C, 255°C, 260°C, 265°C, 270°C, 275°C, 282°C, 285°C, 290°C, 295°C, 300°C, etc.; the injection molding temperature is 150–350°C, for example, 150°C, 180°C, 200°C, 220°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, etc.

[0065] Preferably, the injection speed is 1–150 mm / s, for example, it can be 1 mm / s, 2 mm / s, 4 mm / s, 6 mm / s, 8 mm / s, 10 mm / s, 15 mm / s, 20 mm / s, 25 mm / s, 30 mm / s, 35 mm / s, 40 mm / s, 45 mm / s, 50 mm / s, 55 mm / s, 60 mm / s, 65 mm / s, 70 mm / s, 75 mm / s, 80 mm / s, 85 mm / s, 90 mm / s, 95 mm / s, 100 mm / s, 105 mm / s, 110 mm / s, 115 mm / s, 120 mm / s, 12 5mm / s, 130mm / s, 135mm / s, 140mm / s, 145mm / s, 150mm / s, etc.; injection pressure is 0.1~300MPa, for example, it can be 0.1MPa, 0.5MPa, 1MPa, 5MPa, 10MPa, 20MPa, 30MPa, 40MPa, 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, 100MPa, 120MPa, 140MPa, 160MPa, 180MPa, 200MPa, 220MPa, 240MPa, 260MPa, 280MPa, 300MPa, etc.

[0066] Preferably, the blow molding temperature is 50 to 260°C, for example, it can be 50°C, 60°C, 80°C, 100°C, 120°C, 140°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, etc.

[0067] Preferably, the blow molding pressure is 5–100 bar, for example, 5 bar, 6 bar, 8 bar, 10 bar, 15 bar, 20 bar, 25 bar, 30 bar, 35 bar, 40 bar, 45 bar, 50 bar, 55 bar, 60 bar, 65 bar, 70 bar, 75 bar, 80 bar, 85 bar, 90 bar, 95 bar, 100 bar, etc.; the tensioning speed of the tension bar is 0.05–5. m / s, for example, can be 0.05m / s, 0.06m / s, 0.08m / s, 0.1m / s, 0.2m / s, 0.5m / s, 0.8m / s, 1m / s, 1.2m / s, 1.5m / s, 1.8m / s, 2m / s, 2.2m / s, 2.5m / s, 2.8m / s, 3m / s, 3.2m / s, 3.5m / s, 3.8m / s, 4m / s, 4.2m / s, 4.5m / s, 4.8m / s, 5m / s, etc.

[0068] In this invention, the injection molding is performed in an injection molding machine, and the blow molding is performed in a blow molding machine, or they can be performed in an integrated injection molding and blow molding machine.

[0069] All materials used in this invention comply with food safety and quality standards such as the US FDA, European EU, Japanese Pharmacopoeia, ISO10993, and GB9685.

[0070] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0071] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0072] The light-blocking packaging product provided by this invention, by adding at least two incompatible polyolefins, not only improves the light-blocking rate but also eliminates the need for materials such as carbon black, ensuring high whiteness of the packaging product. Simultaneously, it reduces the titanium dioxide content in the packaging product, minimizing the risk of titanium dioxide migration into food. Furthermore, it innovatively forms a barrier cake and allows for control over light-blocking efficiency. Moreover, this packaging product is the first domestically developed product. Compared to products made from several imported and mainstream domestic high-light-blocking masterbatches on the market, it significantly reduces injection molding and blow molding energy consumption. The resulting bottle exhibits superior physical properties, better toughness, and lower cost. Domestic production ensures more timely supply and service. Attached Figure Description

[0073] Figure 1 This is a graph showing the light transmittance test data of different formulations in Experiment Example 1 of the present invention.

[0074] Figure 2 This is a graph showing the light transmittance test data of different formulations in Experimental Example 2 of the present invention.

[0075] Figure 3 The graph shows the whiteness and light transmittance test data of the PET light-blocking bottles provided in Examples 1-3 and Comparative Examples 4-7 of this invention.

[0076] Figure 4 The image shown is a scanning electron microscope (SEM) image of a PET light-blocking bottle provided in Embodiment 1 of the present invention.

[0077] Figure 5 The image shows a scanning electron microscope (SEM) image of a PET light-blocking bottle, including Comparative Example 2 of the present invention.

[0078] Figure 6 The above are DSC temperature rise curves of the PET light-blocking bottle provided in Embodiment 1 of the present invention and the PET light-blocking bottle provided in Comparative Example 6.

[0079] Figure 7 The image shows the DSC cooling curves of the PET light-blocking bottle provided in Embodiment 1 of the present invention and the PET light-blocking bottle provided in Comparative Example 6.

[0080] Figure 8 This is a vertical load pressure curve of an empty PET light-blocking bottle after blow molding, including the one provided in Embodiment 1 of the present invention.

[0081] Figure 9 The figure shows the vertical load curve of the empty PET light-blocking bottle after blow molding, including Comparative Example 5 of the present invention. Detailed Implementation

[0082] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0083] All materials used in this invention are commercially available or prepared using conventional methods; unless otherwise specified, the materials used in this invention are as follows:

[0084] Polyester resin: polyethylene terephthalate (PET), intrinsic viscosity 0.8 dL / g, Zhejiang Wankai bottle-grade polyester chips WK-801, dehumidified and dried at 170℃ for 6 hours before use.

[0085] First Polymer

[0086] Cyclic olefin polymers: Cyclic olefin polymers, COP, are ZEONEX350R from Zeon Corporation of Japan.

[0087] Poly(4-methyl-1-pentene): PMP, TPX RT18 from Mitsui Chemicals.

[0088] Titanium dioxide: Chemours R-902.

[0089] Inorganic packing

[0090] Barium sulfate: Sakai Chemical BARIACE B-34.

[0091] Zinc oxide: Lutai LT-AH01.

[0092] Calcined kaolin: BASF Translink 37.

[0093] Metallic pigments: Aluminum pigments, ECKART MASTERSAFE MP100-20B.

[0094] Experimental Example 1

[0095] This experimental example involves adding different proportions of COP, PMP, and other polymers to polyester resin, followed by injection molding and blow molding to obtain polyester packaging products. The light transmittance of the polyester packaging products was then tested. The formulation and light transmittance of the polyester packaging products by weight are shown in Table 1. Wherein, " / " indicates that the component is not in the formulation.

[0096] The preparation method of the polyester packaging product includes: dispersing each component at high speed in a high-speed mixer until the material is uniform, then using an injection molding machine (Chen Hsong EM120-SVP) to inject preforms and a blow molding machine (Lans LS-T12) to blow bottles to obtain bottle products; for different bottles, a 2.5cm×5cm×0.26mm thin film is cut from the same position, and to ensure the accuracy of the test data, its light transmittance is detected using a spectrophotometer with an integrating sphere (Shimadzu UV-2600i), and the light transmittance at 650nm visible light is collected.

[0097] Table 1

[0098] PET 100 90 90 90 90 90 90 90 90 COP / 10 8 6 5 3 5 5 5 PMP / / 2 4 5 7 / / / TPE / / / / / / 5 / / PS / / / / / / / 5 / PMMA / / / / / / / / 5 Light transmittance (%) 91.03 20.86 18.32 18.96 19.27 20.12 22.64 24.28 21.89

[0099] Table 1 shows that COP, PMP, TPE, PS, PMMA, etc., can produce varying degrees of interfacial light-blocking properties with polyester resins. Among them, when COP and PMP are mixed in specific ratios (F3-F6), the resulting polyester composite material has lower light transmittance. Formulations F3 and F4 show better results, indicating that a mass ratio of 4:1 for COP and PMP is optimal, followed by 1.5:1. Furthermore, F7-F9 show that different polymers produce different interfacial light-blocking effects. Bottles made from various combinations of COP and PMP exhibit better light-blocking effects than those made from combinations with other polymers. To more intuitively illustrate the interfacial light-blocking properties of different polymers, this invention uses bar charts to represent light transmittance, as shown below. Figure 1 As shown.

[0100] Experimental Example 2

[0101] In this experimental example, a mixture of COP and PMP with a mass ratio of 1.5:1, which showed good results, was added to polyester resin. Then, different types of inorganic fillers, titanium dioxide, etc., were added to it. After injection molding and blow molding, polyester packaging products were obtained. The formulation of the polyester packaging products by weight is shown in Table 2. Wherein, " / " indicates that the component is not in the formulation. The preparation method and light transmittance test method of the polyester packaging products are the same as those in Experimental Example 1.

[0102] Table 2

[0103] PET 90 90 90 90 COP 3 3 3 3 PMP 2 2 2 2 Barium sulfate 5 / / / Zinc oxide / 5 / / Calcinated kaolin / / 5 / Titanium dioxide / / / 5

[0104] The test data of Experimental Example 2 of this invention are as follows: Figure 2 As shown; by Figure 2 It can be seen that titanium dioxide has better opacity, lower light transmittance, and better light blocking performance; followed by barium sulfate and zinc oxide, while calcined kaolin has the weakest opacity.

[0105] Experimental Example 3

[0106] In this experimental example, polyester resin was mixed with COP, and then a compatibilizer was added. The mixture was then injection molded and blow-blown stretched to obtain a polyester packaging product. The formulation, light transmittance, tensile strength, and elongation at break of the polyester packaging product are shown in Table 3 by weight. In the table, " / " indicates that the component is not in the formulation. The preparation method and light transmittance test method of the polyester packaging product are the same as those in Experiment 1. The tensile strength and elongation at break of the polyester packaging product are tested according to ASTM D638.

[0107] Table 3

[0108]

[0109] As shown in Table 3, adding a low proportion (e.g., 0.5%-2%) of compatibilizer has little effect on the light-blocking properties of the bottle, but it can improve the elongation at break of the material and enhance its flexibility. Therefore, to avoid delamination of the film wall or a decrease in the physical properties and toughness of the bottle after injection molding or blow molding due to poor compatibility, a specific amount of compatibilizer can be added to improve the compatibility between the polymer and the polyester resin.

[0110] Example 1

[0111] This embodiment provides a PET light-blocking bottle. The total amount of each component of the PET light-blocking bottle is 100 parts. By weight, the PET light-blocking bottle includes 90 parts PET, 3.5 parts titanium dioxide, 3 parts cyclic olefin polymer, 2 parts poly4-methyl-1-pentene, 1.1 parts barium sulfate, 0.2 parts metallic aluminum pigment, 0.1 parts polyester wax (Honeywell AC-316), and 0.1 parts antioxidant (BASF, antioxidant 1010).

[0112] This embodiment provides a method for preparing a PET light-blocking bottle, specifically including the following steps:

[0113] (1) All components except 90 parts of PET substrate are uniformly dispersed in a high-speed mixer at 1000 rpm to obtain a mixture; then the mixture is added to a temperature-controlled twin-screw extruder, and plasticized, vacuumed, extruded, cooled, dried by blowing air, spun, screened into particles in a vibrating screen with blowing air, dehumidified and dried, and then weighed and packaged to obtain the blend A. The process parameters of the twin-screw extruder are as follows: feed temperature zone: 280~290℃; equilibrium temperature zone: 270~280℃; discharge temperature zone: 260~270℃; side feeding zone is the equilibrium temperature zone: 260℃; vacuum zone controls the vacuum degree to be 0.6~0.8MPa; extrusion zone temperature: 260℃; circulating cooling water cooling; three-stage blower drying method; pelletizer speed: 800~900r / min.

[0114] (2) The blend A obtained in step (1) is blended with 90 parts of PET base resin and injection molded at 290°C using an injection molding machine (Chen Hsong EM120-SVP) to obtain a preform (where the injection speed is 5-70 mm / s and the injection pressure is 1-30 MPa). The obtained preform is then blown and stretched to a 450 mL bottle using a blow molding machine (Lans LS-T12) to obtain the PET light-blocking bottle. The blow molding temperature for blow molding is 50-150°C, the blow molding pressure is 10-50 bar, and the stretching speed of the stretching rod is 0.5-3 m / s.

[0115] Example 2

[0116] This embodiment provides a PET light-blocking bottle. The total amount of each component in the PET light-blocking bottle is 100 parts. By weight, the PET light-blocking bottle includes 90 parts PET, 3.7 parts titanium dioxide, 3.5 parts cyclic olefin polymer, 1.5 parts poly4-methyl-1-pentene, 0.8 parts zinc oxide, 0.15 parts metallic aluminum pigment, 0.15 parts compatibilizer (POE-g-MAH, Mitsui Chemicals MH5020), 0.1 parts stearate (Singapore Samick SAK-CS-P), and 0.1 parts UV light stabilizer (BASF TINUVIN783).

[0117] This embodiment provides a method for preparing a PET light-blocking bottle, and the specific steps are the same as in Embodiment 1.

[0118] Example 3

[0119] This embodiment provides a PET light-blocking bottle, wherein the total amount of each component of the PET light-blocking bottle is 100 parts: 90 parts PET, 3.9 parts titanium dioxide, 4 parts cyclic olefin polymer, 1 part poly4-methyl-1-pentene, 0.7 parts calcined kaolin, 0.1 parts metallic aluminum pigment, 0.1 parts compatibilizer (PP-g-MAH, Arkema 18732), 0.1 parts glyceryl monostearate and 0.1 parts vinyl bis-stearamide wax.

[0120] This embodiment provides a method for preparing a PET light-blocking bottle, and the specific steps are the same as in Embodiment 1.

[0121] Example 4

[0122] This embodiment provides a PET light-blocking bottle, which differs from Embodiment 1 only in that, in step (2), the blend A obtained in step (1) is blended with 90 parts of PET substrate, and the preform is obtained by injection molding at 280°C using an injection molding machine (HUSKY HyPET90) (preform specifications: 38mm mouth single thread preform, height 79mm, maximum diameter 42mm), the injection pressure is 2.6MPa, the injection speed is 10~30mm / s, and the total cycle time is 15s. Then, the obtained preform is blow-blown and stretched into a 285mL bottle body using a blow molding machine (SIDEL SBO 2 / 1010443) (bottle body specifications: average wall thickness 0.3mm, height 176mm, maximum diameter 53.7mm, full mouth capacity 285ml), wherein the oven temperature is 70°C, the blow-blowing temperature is 144°C, the blow-blowing pressure is 28bar, and the stretching speed of the stretching rod is 1.7m / s, thus obtaining the PET light-blocking bottle.

[0123] Example 5

[0124] This embodiment provides a PET light-blocking bottle, which differs from Embodiment 4 only in that the injection stretch blow molding process parameters in step (2) are different. The injection speed is 20-40 mm / s, the blow molding temperature is 135°C, and the stretching speed is 1.9 m / s. Other process parameters are the same as in Embodiment 4.

[0125] Example 6

[0126] This embodiment provides a PET light-blocking bottle, which differs from Embodiment 3 only in that step (2) uses the equipment combination of Embodiment 4, and the injection stretch blow molding process parameters are different. The injection speed is 20-40 mm / s, the blow molding temperature is 135℃, and the stretching speed is 1.9 m / s. Other process parameters are the same as those in Embodiment 3.

[0127] Example 7

[0128] This embodiment provides a PET light-blocking bottle, which differs from Example 1 only in that the total amount of the cyclic olefin polymer and poly-4-methyl-1-pentene remains unchanged, and the mass ratio is 1:1. The other components, amounts, and preparation methods are the same as in Example 1.

[0129] Example 8

[0130] This embodiment provides a PET light-blocking bottle, which differs from Example 1 only in that the total amount of the cyclic olefin polymer and poly-4-methyl-1-pentene remains unchanged, and the mass ratio is 4.5:1. The other components, amounts, and preparation methods are the same as in Example 1.

[0131] Example 9

[0132] This embodiment provides a PET light-blocking bottle, which differs from Embodiment 1 only in that the PET light-blocking bottle contains 0.2 parts of barium sulfate and 1.1 parts of metallic aluminum pigment. The other components, dosages, and preparation methods are the same as in Embodiment 1.

[0133] Example 10

[0134] This embodiment provides a PET light-blocking bottle, which differs from Embodiment 1 only in that the PET light-blocking bottle contains 1.3 parts of barium sulfate and 0 parts of metallic aluminum pigment, while the other components, dosages, and preparation methods are the same as in Embodiment 1.

[0135] Example 11

[0136] This embodiment provides a PET light-blocking bottle, which differs from Embodiment 1 only in that the amount of titanium dioxide used is 3 parts, and it also includes 1 part of transparent blue 2B (CI-index number: Solvent Blue 104, an organic dye with blue color). The other components, amounts, and preparation methods are the same as in Embodiment 1.

[0137] Example 12

[0138] This embodiment provides a PET light-blocking bottle, which differs from Embodiment 2 only in that the content of the compatibilizer is 1.5 parts, while the other components, dosages, and preparation methods are the same as in Embodiment 2.

[0139] Comparative Example 1

[0140] This comparative example provides a PET light-blocking bottle, which differs from Example 1 only in that the total amount of the first polymer remains unchanged, and poly4-methyl-1-pentene is not present. The other components, amounts, and preparation methods are the same as in Example 1.

[0141] Comparative Example 2

[0142] This comparative example provides a PET light-blocking bottle, which differs from Example 1 only in that the total amount of the first polymer remains unchanged, there is no cyclic olefin polymer, and the other components, amounts, and preparation methods are the same as in Example 1.

[0143] Comparative Example 3

[0144] This comparative example provides a PET light-blocking bottle, which differs from Example 1 only in that poly4-methyl-1-pentene is replaced with an equal mass of polyethylene, and the cyclic olefin polymer is replaced with an equal mass of polypropylene. All other components, amounts, and preparation methods are the same as in Example 1.

[0145] Comparative Example 4

[0146] This comparative example provides a PET light-blocking bottle, which differs from Example 1 only in that it includes 93.2 parts of PET and 6.8 parts of titanium dioxide; the preparation method of the packaging product is the same as that of Example 1.

[0147] Comparative Example 5

[0148] This comparative example provides a PET light-blocking bottle, which differs from Example 1 only in that the PET light-blocking bottle comprises 90 parts PET and 10 parts Hanhui's LBS-1 light-blocking material, and the preparation method of the PET light-blocking bottle is the same as that of Example 1.

[0149] Comparative Example 6

[0150] This comparative example provides a PET light-blocking bottle, which differs from Example 1 only in that the PET light-blocking bottle comprises 90 parts PET and 10 parts commercially available light-blocking masterbatch 1. The commercially available light-blocking masterbatch 1 differs from Hanhui's LBS-1 only in that the carbon black content is half that of Hanhui's LBS-1. The preparation method of the PET light-blocking bottle is the same as that of Example 1.

[0151] Comparative Example 7

[0152] This comparative example provides a PET light-blocking bottle, which differs from Example 1 only in that the PET light-blocking bottle comprises 90 parts PET and 10 parts light-blocking masterbatch 2. The light-blocking masterbatch 2 differs from Hanhui's LBS-1 only in that the carbon black content is twice that of Hanhui's LBS-1. The preparation method of the PET light-blocking bottle is the same as that of Example 1.

[0153] Test Example 1

[0154] The whiteness and light transmittance of the PET light-blocking bottles provided in Examples 1-12 and Comparative Examples 1-7 of this invention were tested, as follows:

[0155] For Examples 4-6, thin slices of PET light-blocking bottles measuring 4cm × 4cm × 0.30mm were cut. For the other examples and comparative examples, thin slices of PET light-blocking bottles measuring 4cm × 4cm × 0.26mm were cut, and their whiteness and light transmittance were tested. The whiteness was measured using a KONICAMINOLTA CM-3700A chromatograph, and the L, a, and b values ​​were measured respectively. The light transmittance was measured using a Shimadzu UV-2600i spectrophotometer with an integrating sphere.

[0156] The whiteness L-value and light transmittance of the PET light-blocking bottles provided in Examples 1-3 and Comparative Examples 4-7 are as follows: Figure 3 As shown in Table 4, the whiteness L-value and light transmittance of the PET light-blocking bottles provided in Examples 1-4 and Comparative Examples 4-7 are shown in Table 4.

[0157] Table 4

[0158]

[0159] As shown in Table 4, the PET light-blocking bottle provided by the present invention, by adding at least two incompatible polyolefins to the base resin, can have high light blocking rate and whiteness with a low titanium dioxide content; the L value of the PET light-blocking bottle is ≥91.77; and the light transmittance is ≤0.05%.

[0160] Compared to the traditional method of simply adding titanium dioxide (Comparative Example 4), the titanium dioxide content in the PET light-blocking bottle described in this invention is lower (<4.5%), which is significantly lower than that in Comparative Example 4 (titanium dioxide content is 6.8%), but the material still has high whiteness and low light transmittance.

[0161] Compared to the traditional combination of titanium dioxide and carbon black (Comparative Example 5), the PET light-blocking bottle provided by this invention has lower light transmittance and higher whiteness.

[0162] Compared to adding commercially available barrier masterbatch (Comparative Example 6), the PET light-blocking bottle provided by the present invention has lower light transmittance and higher whiteness.

[0163] Compared to the high carbon black content scheme (Comparative Example 7), the PET light-blocking bottle provided by the present invention ensures high light blocking rate while having higher whiteness.

[0164] Test Example 2

[0165] Taking the PET light-blocking bottles provided in Example 1 and Comparative Example 2 as examples, the microstructure of the PET light-blocking bottles was tested, as follows:

[0166] The microstructure of the PET light-blocking bottles provided in Example 1 and Comparative Example 2 was characterized using a scanning electron microscope (JEOL, JSM-7900F); the results are as follows. Figure 4 (Example 1) and Figure 5 As shown in (Comparative Example 2); by Figure 4 It is known that by compounding cyclic olefin polymers with poly4-methyl-1-pentene, smaller and thinner barrier cakes are formed after stretching. The barrier cakes have a length of 4 μm and a thickness of 1 μm, with a length-to-thickness ratio of 4. These barrier cakes are embedded in the pores formed by the polyester resin, resulting in more phase interfaces. Figure 5 It can be seen that when only poly4-methyl-1-pentene is used, the resulting barrier cake is longer and thicker, in which... Figure 5 The barrier cake has a length of 7μm and a thickness of 2μm, with a length-to-thickness ratio of 3.5. The barrier cake is embedded in the pores formed by the polyester resin, resulting in fewer phase interfaces.

[0167] Test Example 3

[0168] Taking the PET light-blocking bottles provided in Example 1 and Comparative Example 6 as examples, their thermal performance was tested as follows:

[0169] The thermal properties of the PET light-blocking bottle provided in Example 1 and the PET light-blocking bottle provided in Comparative Example 6 were characterized using a differential scanning calorimeter (NETZSCH DSC 214 differential scanning calorimeter, Germany); the results are as follows. Figure 6 and Figure 7 As shown.

[0170] in, Figure 6 The graph shows the heating curves of the PET light-blocking bottle provided in Embodiment 1 and the PET light-blocking bottle provided in Comparative Example 6. Figure 6It can be seen that during the heating process, both the samples based on Example 1 and Comparative Example 6 exhibited obvious endothermic peaks around 244℃, and the absorbed heat energy was also basically the same (27.18 J / g and 27.9 J / g), indicating that both underwent melting endothermicly. However, the sample based on Example 1 also showed an endothermic peak at 235.8℃, indicating that this sample had already begun to melt in an earlier temperature range, suggesting that the PET light-blocking bottle provided by the present invention has a wider melting temperature window. It also indicates that the PET light-blocking bottle provided by the present invention, through heterogeneous nucleation, easily generates polymer crystals with smaller sizes, which may contribute to shock absorption and improve bottle toughness, generally benefiting packaging performance. Secondly, both exhibited a small heat capacity change step around 84℃ to 85℃, indicating that both underwent glass transition around this temperature; this shows that the PET light-blocking bottle of the present invention has little impact on the processing technology of the blow molding section.

[0171] Figure 7 The graph shows the cooling curves of the polyester composite materials including the PET light-blocking bottle provided in Example 1 and the PET light-blocking bottle provided in Comparative Example 6; Figure 7 It can be seen that during the cooling process, the sample based on Example 1 of the present invention first shows a significant exothermic peak at around 187.6℃, with an exothermic energy of 28.36 J / g, while the sample based on Comparative Example 6 only shows a significant exothermic peak at around 166.6℃, with an exothermic energy of 28.36 J / g. This indicates that the sample based on Example 1 of the present invention begins to exothermically crystallize first. Moreover, comparing the peak shapes of the two, it can be seen that the exothermic peak of the sample based on Example 1 of the present invention is steep, while the exothermic peak of the sample based on Comparative Example 6 is flat. This indicates that the PET light-blocking bottle provided by the present invention has a strong heterogeneous nucleation effect. Under the premise that there are no problems in the injection molding process, this means that the molecular chains of the PET light-blocking bottle provided by the present invention are more likely to be arranged regularly during blow molding, making blow molding easier.

[0172] In summary, the PET light-blocking bottle provided by this invention has better compatibility among its components, is easier to disperse evenly in the injection molding machine screw, and requires a lower injection temperature, which can be reduced by 3-5℃. Especially in the first and second stages of injection molding, the temperature can be reduced by 5-8℃, which significantly saves processing energy consumption and improves the yield of finished products to a certain extent. It also improves the product's size and appearance, such as pinholes, trailing edges, flash, and stress distribution.

[0173] Test Example 4

[0174] Taking the PET light-blocking bottles provided in Example 1 and Comparative Example 5 as examples, their impact on the processing technology was tested, as follows:

[0175] The PET light-blocking bottles provided in Example 1 and Comparative Example 5 were blown into individual containers with a mass of 21g and a volume of 350mL. These were then compressed at a compression speed of 50mm / min and a maximum compression of 10mm. The yielding and deformation of the bottles were observed by comparing the vertical load on an empty bottle with the results. Figure 8 (Example 1) and Figure 9 As shown in (Comparative Example 5); where, Figure 8 To conduct parallel testing on 4 bottle samples; Figure 9 To conduct parallel testing of 5 bottle samples; by Figure 8 and Figure 9 The comparison shows that the PET light-blocking bottle provided by the present invention only deforms and yields after being compressed significantly; this indicates that the blown bottle body of the PET light-blocking bottle provided by the present invention is more stable, with higher toughness and strength; furthermore, this indicates that the PET light-blocking bottle provided by the present invention is easier to blow mold, has a wider blowing process window, better molding, and more full at all angles of the bottom standing surface, which can appropriately reduce pre-blowing time and pressure, and the bottle body pressure is also more stable.

[0176] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A light-blocking packaging product, characterized in that, By weight, the light-blocking packaging product comprises 80-94 parts polyester, 3-12 parts first polymer and 2-10 parts titanium dioxide; The first polymer comprises a cyclic olefin polymer and poly4-methyl-1-pentene in a mass ratio of (0.4~4):1; The mass percentage of titanium dioxide in the light-blocking packaging product is <10%; The dispersed phase of the first polymer is a cake-shaped barrier phase; The aspect ratio of the average diameter to the average thickness of the disc-shaped barrier phase is 2.5 to 10. The light-blocking packaging product also includes 0.02 to 6 parts of inorganic filler; The inorganic filler is zinc oxide, barium sulfate, or calcined kaolin.

2. The light-blocking packaging product according to claim 1, characterized in that, The mass ratio of the cyclic olefin polymer to poly4-methyl-1-pentene is (1.5~4):

1.

3. The light-blocking packaging product according to claim 1, characterized in that, The titanium dioxide includes rutile titanium dioxide.

4. The light-blocking packaging product according to claim 1, characterized in that, The polyester and the first polymer form an island structure, wherein the polyester constitutes a continuous phase and the first polymer constitutes a dispersed phase.

5. The light-blocking packaging product according to claim 1, characterized in that, The average diameter of the disc-shaped barrier phase is 0.5~40μm, and the average thickness is 0.05~10μm.

6. The light-blocking packaging product according to claim 1, characterized in that, The light-blocking packaging product also includes 0.0002 to 1 part of metallic pigment by weight.

7. The light-blocking packaging product according to claim 1, characterized in that, The inorganic filler has a mesh size of 40 to 30,000 mesh.

8. The light-blocking packaging product according to claim 6, characterized in that, The average particle size of the metallic pigment is 1~100μm.

9. The light-blocking packaging product according to claim 6, characterized in that, The metallic pigment includes at least one of elemental metal, metal oxide, or metal alloy.

10. The light-blocking packaging product according to claim 9, characterized in that, The metallic pigment is an elemental metal and / or a metal oxide.

11. The light-blocking packaging product according to claim 6, characterized in that, The metal in the metallic pigment includes at least one of aluminum, iron, zinc, copper, or silver.

12. The light-blocking packaging product according to claim 11, characterized in that, The metal in the metallic pigment is aluminum.

13. The light-blocking packaging product according to claim 1, characterized in that, The light-blocking packaging product further includes 0.0002 to 1 part compatibilizer by weight.

14. The light-blocking packaging product according to claim 13, characterized in that, The compatibilizer includes at least one of maleic anhydride-grafted polyethylene, maleic anhydride-grafted polypropylene, maleic anhydride-grafted polyolefin elastomer, or glycidyl methacrylate-grafted polyolefin elastomer.

15. The light-blocking packaging product according to claim 1, characterized in that, The light-blocking packaging product further includes 0.0002 to 4 parts of other additives by weight.

16. The light-blocking packaging product according to claim 15, characterized in that, The other additives include at least one of dispersants, lubricants, antioxidants, heat absorbers, light stabilizers, antistatic agents, or colorants.

17. The light-blocking packaging product according to claim 1, characterized in that, The polyester comprises at least one of the following: polyethylene terephthalate, glycol-modified polyethylene terephthalate, diacid-modified polyethylene terephthalate, polycyclohexanediol terephthalate, glycol-modified polycyclohexanediol terephthalate, diacid-modified polycyclohexanediol terephthalate, polybutylene terephthalate, polyethylene naphthalate, polylactide, polyhydroxyalkanoates, polybutylene adipate / terephthalate, polybutylene succinate, polybutylene adipate, polycaprolactone, or polyarylate.

18. The light-blocking packaging product according to claim 1, characterized in that, The polyester includes amorphous copolyester.

19. The light-blocking packaging article according to claim 17, characterized in that, The polyester is at least one of polyethylene terephthalate, glycol-modified polyethylene terephthalate, polylactide, polyhydroxyalkanoate, or polyarylate.

20. The light-blocking packaging product according to claim 1, characterized in that, The light-blocking packaging products include at least one of the following: extruded blow molded products, injection molded products, injection blow molded products, compression molded products, blister packaging products, or injection stretch blow molded products.

21. The light-blocking packaging article according to claim 20, characterized in that, The light-blocking packaging product is an injection-stretch blow-molded product.

22. The light-blocking packaging product according to claim 21, characterized in that, The light-blocking packaging products include light-blocking bottles.

23. The light-blocking packaging article according to any one of claims 1 to 22, characterized in that, The light-blocking packaging product meets the following conditions: (1) The whiteness of the light-blocking packaging product is 80~100; and (2) The light transmittance of the light-blocking packaging product in the 550nm band is 0~2%.

24. A method for preparing a light-blocking packaging article according to any one of claims 1 to 19, characterized in that, The preparation method includes: A formulation is formed by mixing 80-94 parts polyester, 3-12 parts first polymer, 2-10 parts titanium dioxide, 0.02-6 parts inorganic filler, and optionally 0.0002-1 part metallic pigment, 0.0002-1 part compatibilizer, and 0.0002-4 parts other additives, and is used to mold the light-blocking packaging product.

25. The method for preparing the light-blocking packaging product according to claim 24, characterized in that, The components in the formula are directly added to the equipment for processing and molding, or are first extruded and granulated together with at least one other component, and the resulting particles are then added to the equipment for processing and molding, or the resulting particles are added to the equipment together with other formula components for processing and molding.

26. The method for preparing the light-blocking packaging product according to claim 25, characterized in that, The molding method includes first molding the formula to obtain a preform or preform; then molding the preform or preform to obtain the light-blocking packaging product.

27. The method for preparing the light-blocking packaging product according to claim 26, characterized in that, The first molding method includes at least one of extrusion molding, injection molding, or compression molding.

28. The method for preparing the light-blocking packaging product according to claim 26, characterized in that, The second molding method includes blow molding and / or vacuum molding.

29. The method for preparing the light-blocking packaging product according to claim 25, characterized in that, The molding method includes extruding and granulating the formula, injection molding to obtain a preform or preform; and then blow molding the preform or preform to obtain the light-blocking packaging product.

30. The method for preparing the light-blocking packaging product according to claim 29, characterized in that, The injection molding and blow molding include two-step and / or one-step methods.

31. The preparation method according to claim 29, characterized in that, The extrusion temperature is 250~300℃, and the injection molding temperature is 150~350℃.

32. The preparation method according to claim 29, characterized in that, The injection speed is 1~150mm / s, and the injection pressure is 0.1~300MPa.

33. The preparation method according to claim 29, characterized in that, The blow molding temperature is 50~260℃, the blow molding pressure is 5~100 bar, and the stretching speed of the stretching rod is 0.05~5 m / s.

Images