Light-blocking packaging product and preparation method thereof

Abstract

The invention provides a light-blocking packaging product as well as a preparation method and application thereof, and the light-blocking packaging product comprises the following components in parts by weight: 80-99.7 parts of substrate resin, 0.1-12 parts of a first polymer and 0.2-12 parts of titanium dioxide, the first polymer comprises at least two kinds of incompatible polyolefins; the mass percentage content of titanium dioxide in the light-blocking packaging product is less than 10%. According to the light-blocking packaging product disclosed by the invention, at least two kinds of incompatible polyolefin are added into the light-blocking packaging product, so that the light-blocking rate can be improved, and the high whiteness of the light-blocking packaging product is ensured; meanwhile, the content of titanium dioxide in the light-blocking packaging product can be reduced, and the risk that the titanium dioxide is migrated into food is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of packaging materials, and in particular relates to a light-blocking packaging product and a preparation method thereof. Background Art

[0002] In the packaging of dairy products, including milk drinks or yogurt products, light protection is one of the factors that need to be considered. Because light has a very obvious impact on dairy products, light will destroy the nutrients in milk, stimulate unstable substances in milk to produce free radicals, and thus accelerate the oxidation and deterioration of milk; among them, the most common reaction of milk under light conditions is the oxidation reaction of cysteine ​​triggered by light, which will generate sulfides such as mercaptans and dimethyl sulfide, all of which will seriously affect the taste and nutrition of milk; at the same time, many nutrients in milk such as vitamin A, vitamin B2 (riboflavin), vitamin D and amino acids will also be lost due to light.

[0003] At present, many dairy products are packaged and sold in cold chain, but the short shelf life, high storage and transportation costs, and narrow sales radius have seriously affected the sales scope and sales volume. There are also dairy companies that use Tetra Pak paper plastic packaging for room temperature sales after high-temperature sterilization. The shelf life can be extended to half a year or even 9 months, and the sales scope can be expanded to the whole country, but Tetra Pak packaging has problems such as large equipment investment, single packaging specifications, and no way to reseal once opened, and it is difficult to recycle and reuse. Therefore, room temperature plastic packaging is favored by more and more dairy companies and consumers, among which polyester plastic packaging is the most popular. Polyester packaging has its unique advantages: such as diversified bottle design, high production efficiency, universal injection molding processing equipment, and avoidance of repeated investment. However, polyester plastic packaging has the characteristics of high light transmittance, which is contrary to the requirement of high light blocking for dairy products. Therefore, it is necessary to add high light blocking materials (the light blocking is preferably above 99.9%) to improve the light blocking performance of polyester packaging bottles, thereby protecting the quality of dairy products and extending the shelf life.

[0004] Among the mainstream high light-blocking materials on the market, titanium dioxide is more commonly used due to its high whiteness and high reflectivity. Among them, the content of titanium dioxide is usually 6% to 8%. However, the light-blocking rate that can be achieved by adding only titanium dioxide is limited and cannot meet the demand for high light-blocking rate in dairy product packaging. In addition, titanium dioxide has safety risks. The content or addition ratio of titanium dioxide used in food packaging needs to be controlled as much as possible to minimize the risk of its migration into food and beverages. In addition, carbon black is also added to titanium dioxide to increase the absorption rate of light, thereby achieving high light-blocking performance. However, the introduction of carbon black also reduces the whiteness of the entire bottle body. The gray appearance of the bottle body lowers the texture and aesthetics of the packaging. Although the outside of the bottle body is usually completely wrapped with a label, the bottle mouth will still be exposed after opening the lid, affecting the sensory experience of consumers.

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

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a light-blocking packaging product and a preparation method thereof. The light-blocking packaging product solves the problem that the dairy product packaging material in the prior art cannot have both high light-blocking and high whiteness, and the potential migration risk caused by the high content of titanium dioxide.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a light-blocking packaging product, which comprises, by weight, 80 to 99.7 parts of a base material 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 product is less than 10%.

[0009] In the present invention, by adding at least two incompatible polyolefins to the base resin, due to the differences in compatibility and thermodynamic properties between different polymers, there is an obvious interface effect with the polyester resin, forming an island structure in the polyester matrix, and after subsequent stretching processing, the first polymer will form a pancake shape with a certain aspect ratio, and will be partially embedded in the holes 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 transmittance of light, thereby achieving a light-blocking effect; by adding the first polymer with a specific composition and content, not only can the light-blocking rate be improved, but also there is no need to add materials such as carbon black, thereby ensuring the high whiteness of the packaging product; at the same time, the content of titanium dioxide in the packaging product can be reduced, and the risk of titanium dioxide migrating into food can be minimized.

[0010] In the present invention, 80 to 99.7 parts of the polyester resin may 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 the present invention, 0.1 to 12 parts of the first polymer can be, for example, 0.1, 0.5, 1, 2, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, etc.

[0012] In the present invention, 0.2 to 12 parts of titanium dioxide can be, for example, 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 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 the present invention, the mass percentage of titanium dioxide in the light-blocking packaging product is less than 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 further preferably, the mass percentage of titanium dioxide in the light-blocking packaging product is ≤4%.

[0014] In the present 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 cycloaliphatic polyolefin and at least one aliphatic polyolefin.

[0016] Preferably, the alicyclic polyolefin comprises a cycloolefin polymer; and the aliphatic polyolefin comprises poly-4-methyl-1-pentene.

[0017] Cycloolefin polymer is a non-crystalline transparent polymer material that is both light and transparent, and is the preferred material for optical lenses and various screen membranes. It has a large aliphatic ring structure in the main chain of the molecule, so it is amorphous and has a high glass transition temperature. It also has the characteristics of low water absorption, high rigidity, high heat resistance, good water vapor airtightness, etc., and complies with food safety standards such as the US FDA, European EU, Japanese Pharmacopoeia and ISO10993. In recent years, it has gradually become a high-end material to replace glass and other plastics, and is widely used in pre-filled syringes, infusion bags, contrast agents, hyaluronic acid packaging bottles and other medical, pharmaceutical, cosmetic and other fields.

[0018] Poly-4-methyl-1-pentene, also known as polymethylpentene, is called poly(4-methyl-1-pentene) in English, referred to as PMP, and its chemical formula is (C6H 12 ) n , the structural formula is The synthesis process includes: dimerizing propylene to obtain 4-methyl-1-pentene; then polymerizing 4-methyl-1-pentene to obtain poly-4-methyl-1-pentene. Poly-4-methyl-1-pentene is a thermoplastic resin with low density. It is a colorless and transparent granular solid with a density of 0.835g / cm3 , excellent heat resistance, melting point of 240℃, visible light transmittance of 90%, ultraviolet light transmittance better than glass and other transparent resins, and excellent electrical insulation and chemical resistance. Because polymethylpentene is safe and non-toxic, it is widely used in medical instruments (such as syringes), physical and chemical experimental instruments, electronic stove special utensils, baking trays and other fields.

[0019] In the present invention, due to the differences in compatibility and thermodynamic properties between different polymers, cycloolefin polymers and poly-4-methyl-1-pentene have obvious interface effects with the substrate resin, forming an island structure in the substrate resin, and after subsequent stretching processing, the first polymer will form a pancake shape with a certain aspect ratio, and will be partially embedded in the holes formed by the stretching of the substrate resin, forming a large number of irregular multiphase interfaces. When light passes through these interfaces, it is continuously scattered, reflected and refracted, reducing the transmittance of light, thereby achieving a light-blocking effect; the use of cycloolefin polymers and poly-4-methyl-1-pentene compound can not only improve the light-blocking rate of the packaging product, but also does not need to add materials such as carbon black, thereby ensuring the high whiteness of the packaging product; at the same time, it can also reduce the content of titanium dioxide in the packaging product, and minimize 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 value in (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, it is (1.5-4):1.

[0021] In the present invention, alicyclic polyolefins and aliphatic polyolefins are compounded in a specific mass ratio, which can adjust the microscopic morphology of the first polymer in the substrate resin (wherein the substrate resin is a continuous phase and the first polymer is a barrier phase). After subsequent stretching processing, the barrier cake formed by the first polymer has a smaller length, a thinner thickness, and a smaller size; and the barrier cake with a smaller size is embedded in the holes formed by stretching the substrate 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 as follows: alicyclic polyolefins and aliphatic polyolefins are compounded in a specific mass ratio, which can adjust the viscosity of the dispersed phase, resulting in changes in the interfacial strength, thereby changing the presentation morphology of the dispersed phase in the substrate resin. This is a brand-new research discovery of the present invention.

[0022] Preferably, the cycloolefin polymer includes olefin and cycloolefin copolymers and / or cycloolefin polymers.

[0023] Olefin and cycloolefin copolymer, English name Cyclo-Olefin Copolymer, referred to as COC, is formed by copolymerization of olefin and cycloolefin; in the COC, the olefin includes ethylene; the cycloolefin includes norbornene; illustratively, the structural formula of the copolymer formed by ethylene and norbornene is It is obtained by polymerizing ethylene and norbornene; wherein, norbornene can be prepared by DA reaction of ethylene and cyclopentadiene (or dicyclopentadiene); cycloolefin polymer, English name Cyclo Olefin Polymer, referred to as COP, is formed by the polymerization of cycloolefin monomers; in the COP, the cycloolefin includes norbornene; illustratively, the structural formula of the polymer formed by the norbornene is

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

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

[0026] Preferably, the base resin and the first polymer form a sea-island structure, the base resin constitutes a continuous phase, and the first polymer constitutes a dispersed phase.

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

[0028] Preferably, the average diameter of the cake-shaped barrier phase is 0.5-40 μm, for example, 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.; preferably 1-20 μm, more preferably 1-20 μm. It is preferably 2-10μm, and particularly preferably 2.5-5μm; the average thickness is 0.05-10μm, for example, it can be 0.05μm, 0.1μm, 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, etc.; it is preferably 0.1-5μm, more preferably 0.2-3μm, and particularly preferably 0.5-2μm.

[0029] Preferably, the aspect ratio of the average diameter to the average thickness of the cake-shaped barrier phase is 1.2-100, 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 1.5-50, more preferably, it is 2-20, and particularly preferably, it is 2.5-8.

[0030] Preferably, in parts by weight, the light-blocking packaging product also includes 0.02 to 6 parts of inorganic filler (for example, 0.02 parts, 0.05 parts, 0.1 parts, 0.5 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, etc.) and / or 0.0002 to 1 parts of metallic pigment (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 parts, etc.).

[0031] Preferably, the mesh number of the inorganic filler is 40 to 30000 mesh, for example, it can be 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, it is 100 to 10000 mesh, more preferably, it is 500 to 5000 mesh, and particularly preferably, it is 1000 to 3000 mesh.

[0032] Preferably, the inorganic filler comprises 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 to 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., further preferably 2 to 50 μm, more preferably 5 to 35 μm, and particularly preferably 10 to 20 μm.

[0034] Preferably, the metallic pigment includes at least one of a metal element, a metal oxide or a metal alloy, and more preferably a metal element and / or a 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 the present invention, the inorganic filler and the metal pigment can play a steric hindrance effect; by adding a specific content of inorganic filler and / or metal pigment, the light blocking performance can be further improved, and the titanium dioxide content can be reduced without affecting the whiteness of the packaging product.

[0037] Preferably, the light-blocking packaging product further includes 0.0002 to 1 parts of a 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] In order to avoid problems such as product delamination or decreased mechanical properties due to poor compatibility, it is preferred to add a specific amount of compatibilizer without affecting the light-blocking properties.

[0040] Preferably, the light-blocking packaging product further includes 0.0002 to 4 parts of other additives, by weight, for example, 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 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, etc.

[0041] Preferably, the other auxiliary agents include at least one of a dispersant, a lubricant, an antioxidant, a heat absorbent, a light stabilizer, an antistatic agent or a colorant.

[0042] In the present invention, other additives can be added according to actual needs, not limited to the above-mentioned other additives; for example, in order to facilitate the processing and production of products and improve dispersibility and processing performance, dispersants and / or lubricants can be added, and the 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 wax (such as vinyl bisstearamide EBS, erucamide, oleamide, etc.), pentaerythritol stearate (PETS), etc.; and the introduction of specific types of waxes will also have a positive effect on the light-blocking performance.

[0043] In order to improve the quality and stability of packaging materials and contents, antioxidants may be added, including but not limited to high molecular weight hindered phenol antioxidants, solid organic phosphite antioxidants, etc.; in order to improve the re-absorption performance of the material, endothermic agents are added, including but not limited to carbon black, tungsten oxide, activated carbon, titanium nitride, zinc nitride, etc.; in order to improve the light stability of the material, light stabilizers are added, including but not limited to UV234, UV1577, UV1164, UV360, UV3638, etc.; in order to improve the antistatic performance of the material, antistatic agents are added, including but not limited to cationic surfactants, anionic surfactants, etc.

[0044] In the present invention, colorants such as pigments or organic dyes can be added according to actual needs, which can be used to improve whiteness or present a colorful 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 comprises 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 at least one of polyester, polycarbonate, polypropylene carbonate, polyamino acid, cellulose, thermoplastic starch, polyvinyl alcohol, chitosan, polyhydroxyalkanoate or thermoplastic elastomer.

[0046] Preferably, the polyester includes at least one of polyethylene terephthalate (PET), glycol-modified polyethylene terephthalate (PETG), diacid-modified polyethylene terephthalate, polycyclohexanedimethanol terephthalate (PCT), glycol-modified polycyclohexanedimethanol terephthalate (PCTG), diacid-modified polycyclohexanedimethanol terephthalate, cyclohexanedimethanol and terephthalic acid copolyester (PCTA), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polylactide (PLA), polyhydroxyalkanoate (PHA), polybutylene adipate / terephthalate (PBAT), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polycaprolactone (PCL), non-crystalline copolyester or polyarylate.

[0047] Preferably, the thermoplastic elastomer includes at least one of styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-ethylene-butylene-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 vulcanized 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 comprises at least one of an extrusion blow-molded product, an injection molded product, an injection blow-molded product, a compression molded product, a blister molded product or an injection stretch blow-molded product; preferably, an injection stretch blow-molded product.

[0050] Preferably, the light-blocking packaging product comprises 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, 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, 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 the light-blocking packaging product according to the first aspect, the preparation method comprising:

[0054] 80-99.7 parts of base resin, 0.1-12 parts of first polymer and 0.2-12 parts of titanium dioxide and optionally 0.02-6 parts of inorganic filler, 0.0002-1 parts of metal pigment, 0.0002-1 parts of compatibilizer and 0.0002-4 parts of other additives are formulated for molding the light-blocking packaging product.

[0055] In the present invention, the components in the formula are directly added into the equipment for processing and forming, or are first extruded and granulated together with at least one other component, and the produced particles are then added into the equipment for processing and forming, or the produced particles are directly added into the equipment together with other formula components for processing and forming.

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

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

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

[0059] Preferably, the molding method comprises subjecting the formulation to a first molding process to obtain a parison or a preform; and then subjecting the parison or the preform to a second molding process 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 comprises subjecting the formulation to extrusion granulation and injection molding to obtain a parison or a preform; and then subjecting the parison or the preform to blow molding to obtain the light-blocking packaging product.

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

[0064] Preferably, the extrusion temperature is 250-300°C, for example, it can be 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, it can be 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 molding speed is 1 to 150 mm / s, for example, 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, 126 mm / s, 130 mm / s, 131 mm / s, 132 mm / s, 133 mm / s, 134 mm / s, 136 mm / s, 137 mm / s, 138 mm / s, 139 mm / s, 140 mm / s, 141 mm / s, 142 mm / s, 143 mm / s, 144 mm / s The injection pressure is 0.1-300MPa, for example, 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 50-260°C, for example, 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 to 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 stretching rod stretching speed is 0.05 to 5 m / s, for example, it 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 the present invention, the injection molding is performed in an injection molding machine, and the blow molding is performed in a bottle blowing machine, or in an all-in-one injection molding and bottle blowing machine.

[0069] The materials used in the present invention all 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 the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] The light-blocking packaging product provided by the present invention can not only improve the light-blocking rate by adding at least two incompatible polyolefins, but also ensure the high whiteness of the packaging product without adding materials such as carbon black; at the same time, it can also reduce the content of titanium dioxide in the packaging product, and minimize the risk of titanium dioxide migrating into food; and innovatively form a barrier cake and can regulate the light-blocking efficiency; in addition, the packaging product is the first domestically developed product; compared with several imported and domestically mainstream products made of traditional high-light-blocking masterbatches on the market, the energy consumption of injection molding and blowing can be significantly reduced; and the obtained bottle body has better physical properties, better toughness effect, and lower cost; it is produced domestically and the supply service is more timely. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 This is a graph showing the light transmittance test data of different formulations in Test 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 whiteness and light transmittance test data of the PET light-blocking bottles provided in the present invention include Examples 1 to 3 and Comparative Examples 4 to 7.

[0076] Figure 4 This is a scanning electron microscope image of the PET light-blocking bottle provided in Example 1 of the present invention.

[0077] Figure 5 This is a scanning electron microscope image of the PET light-blocking bottle provided in Comparative Example 2 of the present invention.

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

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

[0080] Figure 8 The vertical load pressure curve of the empty bottle of the PET light-blocking bottle provided in Example 1 of the present invention after bottle blowing.

[0081] Fig. 9 The vertical load pressure curve of the empty bottle of the PET light-blocking bottle provided in Comparative Example 5 of the present invention after bottle blowing. DETAILED DESCRIPTION

[0082] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0083] The materials used in the present invention can be purchased from the market or prepared by conventional methods; unless otherwise specified, the materials used in the present invention are as follows:

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

[0085] First polymer

[0086] Cyclic olefin polymer: Cyclic olefin polymer, COP, is ZEONEX350R from Japan Zeon.

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

[0088] Titanium dioxide: Chemours R-902.

[0089] Inorganic fillers

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

[0091] Zinc oxide: Lutai LT-AH01.

[0092] Calcined kaolin: BASF Translink37.

[0093] Metallic pigment: Metallic aluminum pigment, ECKART MASTERSAFE MP100-20B.

[0094] Test Example 1

[0095] In this test example, different proportions of COP, PMP and other polymers of different types are added to the polyester resin, and then the polyester packaging products are obtained by injection molding and bottle blowing and stretching, and then the light transmittance of the polyester packaging products is tested; the formula and light transmittance of the polyester packaging products are shown in Table 1 in parts by weight; wherein, " / " indicates that the component is not included in the formula.

[0096] The preparation method of the polyester packaging product comprises: dispersing each component in a high-speed mixer at high speed until the material is uniform, injecting a preform with an injection molding machine (Zhenxiong EM120-SVP) and blowing a bottle with a blow molding machine (Lance LS-T12) to obtain a bottle product; for different bottles, cutting a 2.5 cm×5 cm×0.26 mm thin slice at the same position, and to ensure the accuracy of the detection data, using a spectrophotometer with an integrating sphere (Shimadzu UV-2600i) to detect its light transmittance, and collecting the light transmittance at 650 nm visible light.

[0097] Table 1

[0098] F1 F2 F3 F4 F5 F6 F7 F8 F9 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] It can be seen from Table 1 that COP, PMP, TPE, PS, PMMA, etc. can produce different degrees of interfacial light-blocking properties with polyester resin; among them, when COP and PMP are mixed in a specific ratio (F3-F6), the obtained polyester composite material has lower light transmittance; among them, the formulas of F3 and F4 have better effects, indicating that when COP and PMP are compounded, the optimal mass ratio of the two is 4:1, and 1.5:1 is the second. In addition, it can be seen from F7-F9 that different types of polymers produce different interfacial light-blocking effects, and the light-blocking effect of bottles made from various combinations of COP and PMP formulas is better than that of formula combinations with other polymers. In order to more intuitively reflect the interfacial light-blocking properties of different polymers, the present invention uses a bar graph to represent the light transmittance, and the results are as follows. Figure 1 shown.

[0100] Test Example 2

[0101] In this test example, a mixture of COP and PMP with a mass ratio of 1.5:1 with a better effect was selected and added to the polyester resin, and then different types of inorganic fillers, titanium dioxide, etc. were added thereto, and a polyester packaging product was obtained by injection molding and blow molding and stretching; the formula of the polyester packaging product is shown in Table 2 in parts by weight; wherein, “ / ” indicates that the component is not included in the formula; the preparation method and light transmittance test method of the polyester packaging product are the same as those in Test Example 1.

[0102] Table 2

[0103] F10 F11 F12 F13 PET 90 90 90 90 COP 3 3 3 3 PMP 2 2 2 2 Barium sulfate 5 / / / Zinc Oxide / 5 / / Calcined Kaolin / / 5 / Titanium dioxide / / / 5

[0104] The test data of Test Example 2 of the present invention is as follows Figure 2 shown by Figure 2 It can be seen that titanium dioxide has better hiding power, lower light transmittance and better light-blocking performance; followed by barium sulfate and zinc oxide, and calcined kaolin has the weakest hiding power.

[0105] Test Example 3

[0106] In this test example, a polyester resin is mixed with COP, and then a compatibilizer is added thereto, and a polyester packaging product is obtained by injection molding and bottle blowing and stretching; the formula, light transmittance, tensile strength and elongation at break of the polyester packaging product are shown in Table 3 in parts by weight; wherein, " / " indicates that the component is not included in the formula; the preparation method and light transmittance test method of the polyester packaging product are the same as those in Test Example 1; the test method of the tensile strength and elongation at break of the polyester packaging product is tested in accordance with ASTMD638.

[0107] Table 3

[0108]

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

[0110] Example 1

[0111] The present embodiment provides a PET light-blocking bottle, wherein the total amount of components of the PET light-blocking bottle is 100 parts, and the PET light-blocking bottle includes, by weight, 90 parts of PET, 3.5 parts of titanium dioxide, 3 parts of cycloolefin polymer, 2 parts of poly-4-methyl-1-pentene, 1.1 parts of barium sulfate, 0.2 parts of metallic aluminum pigment, 0.1 parts of polyester wax (Honeywell AC-316) and 0.1 parts of antioxidant (BASF, antioxidant 1010).

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

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

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

[0115] Example 2

[0116] The present embodiment provides a PET light-blocking bottle, wherein the total amount of components of the PET light-blocking bottle is 100 parts, and the PET light-blocking bottle includes, by weight, 90 parts of PET, 3.7 parts of titanium dioxide, 3.5 parts of cycloolefin polymer, 1.5 parts of poly-4-methyl-1-pentene, 0.8 parts of zinc oxide, 0.15 parts of metallic aluminum pigment, 0.15 parts of compatibilizer (POE-g-MAH, Mitsui Chemicals MH5020), 0.1 parts of stearate (Singapore Samick SAK-CS-P) and 0.1 parts of 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 those in Embodiment 1.

[0118] Example 3

[0119] The present embodiment provides a PET light-blocking bottle, wherein the total amount of components of the PET light-blocking bottle is 100 parts, including 90 parts of PET, 3.9 parts of titanium dioxide, 4 parts of cycloolefin polymer, 1 part of poly 4-methyl-1-pentene, 0.7 parts of calcined kaolin, 0.1 parts of metallic aluminum pigment, 0.1 parts of compatibilizer (PP-g-MAH, Arkema 18732), 0.1 parts of glyceryl monostearate and 0.1 parts of vinyl bisstearamide wax.

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

[0121] Example 4

[0122] The present embodiment provides a PET light-blocking bottle, which differs from the embodiment 1 only in that, in step (2), the blend A obtained in step (1) is blended with 90 parts of PET substrate, and an injection molding machine (HUSKY HyPET90) is used to obtain a bottle embryo (the bottle embryo specification is: 38mm mouth single thread bottle embryo, height 79mm, maximum diameter 42mm) by injection molding at 280°C, the injection pressure is 2.6MPa, the injection speed is 10-30mm / s, and the total cycle time is 15s. Then, the obtained bottle embryo is blown and stretched into a 285mL bottle body by a bottle blowing machine (SIDEL SBO 2 / 1010443) (the bottle body specification is: average wall thickness 0.3mm, height 176mm, maximum diameter 53.7mm, full mouth capacity 285ml), wherein the oven temperature is 70°C, the bottle blowing temperature is 144°C, the bottle blowing pressure is 28bar, and the stretching rod stretching speed is 1.7m / s, to obtain 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-stretching-blowing process parameters of step (2) are different, the injection speed is 20-40 mm / s, the blowing temperature is 135°C, and the stretching speed is 1.9 m / s. The other process parameters are the same as those of Embodiment 4.

[0125] Example 6

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

[0127] Example 7

[0128] This embodiment provides a PET light-blocking bottle, which is different from Embodiment 1 only in that the total amount of the cycloolefin polymer and the 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 those in Embodiment 1.

[0129] Example 8

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

[0131] Example 9

[0132] This embodiment provides a PET light-blocking bottle, which is different from Embodiment 1 only in that the content of barium sulfate in the PET light-blocking bottle is 0.2 parts, and the content of metal aluminum pigment is 1.1 parts. Other components, dosages and preparation methods are the same as those in Embodiment 1.

[0133] Example 10

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

[0135] Embodiment 11

[0136] This embodiment provides a PET light-blocking bottle, which differs from Example 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, organic dye, blue color), and the other components, amounts and preparation methods are the same as those in Example 1.

[0137] Example 12

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

[0139] Comparative Example 1

[0140] This comparative example provides a PET light-blocking bottle, which is different from Example 1 only in that the total amount of the first polymer remains unchanged, there is no poly-4-methyl-1-pentene, and the other components, amounts and preparation methods are the same as those in Example 1.

[0141] Comparative Example 2

[0142] This comparative example provides a PET light-blocking bottle, which is different from Example 1 only in that the total amount of the first polymer remains unchanged, there is no cycloolefin polymer, and the other components, amounts and preparation methods are the same as those 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 poly-4-methyl-1-pentene is replaced by polyethylene of equal mass, and cycloolefin polymer is replaced by polypropylene of equal mass, and other components, amounts used and preparation methods are the same as those 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 is different from Example 1 only in that the PET light-blocking bottle includes 90 parts of PET and 10 parts of 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 of PET and 10 parts of commercially available light-blocking masterbatch 1, and the commercially available light-blocking masterbatch 1 differs from Hanhui's LBS-1 only in that the carbon black content of the commercially available light-blocking masterbatch 1 is half of 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 of PET and 10 parts of light-blocking masterbatch 2, and 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 to 12 of the present invention and Comparative Examples 1 to 7 were tested, as follows:

[0155] For Examples 4 to 6, 4 cm×4 cm×0.30 mm thin sheets of PET light-blocking bottles were cut; for the remaining Examples and Comparative Examples, 4 cm×4 cm×0.26 mm thin sheets of PET light-blocking bottles were cut to test their whiteness and light transmittance. The whiteness was tested using a KONICAMINOLTA chromatograph CM-3700A to detect the L, a, and b values, respectively; the light transmittance was tested 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 to 3 and Comparative Examples 4 to 7 are as follows: Figure 3 As shown; the whiteness L value and light transmittance of the PET light-blocking bottles provided by Examples 1 to 4 and Comparative Examples 4 to 7 are shown in Table 4.

[0157] Table 4

[0158]

[0159] As can be seen from 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 at a lower titanium dioxide content; the L value of the PET light-blocking bottle is ≥91.77; and the light transmittance is ≤0.05%.

[0160] Compared with the conventional solution of adding only titanium dioxide content (Comparative Example 4), the titanium dioxide content in the PET light-blocking bottle of the present 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 with the traditional compounding solution of titanium dioxide and carbon black (Comparative Example 5), the PET light-blocking bottle provided by the present invention has lower light transmittance and higher whiteness.

[0162] Compared with 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 with the solution with high carbon black content (Comparative Example 7), the PET light-blocking bottle provided by the present invention has a higher whiteness while ensuring a high light-blocking rate.

[0164] Test Example 2

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

[0166] The microscopic morphology of the PET light-blocking bottle provided in Example 1 and the PET light-blocking bottle provided in Comparative Example 2 was characterized by a scanning electron microscope (JEOL, JSM-7900F); the results are as follows: Figure 4 (Example 1) and Figure 5 (Comparative Example 2) Figure 4 It can be seen that by compounding the cycloolefin polymer with poly-4-methyl-1-pentene, a smaller and thinner barrier cake is formed after stretching, wherein the barrier cake has a length of 4 μm and a thickness of 1 μm, and a ratio of length to thickness of 4. The barrier cake is embedded in the pores formed by the polyester resin, and more phase interfaces are formed; Figure 5 It can be seen that when there is only poly-4-methyl-1-pentene, the barrier cake formed is longer and thicker, among which, Figure 5 The length of the medium barrier cake is 7 μm, the thickness is 2 μm, and the ratio of the length to the thickness is 3.5. The barrier cake is embedded in the pores formed by the polyester resin, and the formed phase interface is relatively small.

[0167] Test Example 3

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

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

[0170] in, Figure 6 The temperature rise curve diagram of the PET light-blocking bottle provided in Example 1 of the present invention and the PET light-blocking bottle provided in Comparative Example 6; Figure 6It can be seen that during the heating process, the samples based on Example 1 and Comparative Example 6 both showed obvious endothermic peaks near 244°C, and the absorbed heat energy was basically the same (27.18 J / g and 27.9 J / g), indicating that both of them had melt endothermic absorption, but the difference was that the sample based on Example 1 also had an endothermic peak at 235.8°C, indicating that the sample had begun to melt in an earlier temperature range, indicating that the PET light-blocking bottle provided by the present invention has a wider melting temperature window; it also shows that the PET light-blocking bottle provided by the present invention can easily generate smaller polymer crystals through heterogeneous nucleation, which may contribute to absorbing impact and improving the toughness of the bottle body, and is generally beneficial to packaging performance. Secondly, both of them have a small heat capacity change step near 84°C to 85°C, indicating that both of them have glass transition near this temperature; indicating that the PET light-blocking bottle of the present invention has little effect on the processing technology of the bottle blowing section.

[0171] Figure 7 is a temperature drop curve diagram of a polyester composite material including the PET light-blocking bottle provided in Example 1 of the present invention 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 presents a significant exothermic peak near 187.6°C, with an exothermic energy of 28.36 J / g, while the sample based on Comparative Example 6 only presents an obvious exothermic peak near 166.6°C, with an exothermic energy of 28.36 J / g. This indicates that the sample based on Example 1 of the present invention starts exothermic crystallization first, and by 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 gentle, which indicates that the PET light-blocking bottle provided by the present invention has a strong heterogeneous nucleation effect. On the premise that there is no problem with the injection molding process, this means that the molecular chains of the PET light-blocking bottle provided by the present invention are more easily arranged regularly during bottle blowing, and bottle blowing processing is easier.

[0172] In summary, the components of the PET light-blocking bottle provided by the present invention have better fusion properties and are easier to disperse evenly in the screw of the injection molding machine. The required injection molding temperature is lower, which can be reduced by 3-5°C, especially in the first and second stages of injection molding, and can even be reduced by 5-8°C, which significantly saves processing energy consumption, improves the yield of the product to a certain extent, and also improves the product size and appearance, such as pinholes, tailing, flash, stress distribution, etc. to varying degrees.

[0173] Test Example 4

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

[0175] The PET light-blocking bottles provided in Example 1 and Comparative Example 5 were blown into a single container bottle with a mass of 21 g and a volume of 350 mL, and then compressed at a compression speed of 50 mm / min and a maximum compression of 10 mm. The yield and deformation of the bottle body were observed by comparing the vertical pressure of the empty bottle. The results are as follows: Figure 8 (Example 1) and Fig. 9 (Comparative Example 5) is shown; wherein, Figure 8 To test 4 bottle samples in parallel; Fig. 9 To test 5 bottle samples in parallel; Figure 8 and Fig. 9 By comparison, it can be seen that the PET light-blocking bottle provided by the present invention deforms and yields only after being compressed to a large extent; this indicates that the bottle body blown out of the PET light-blocking bottle provided by the present invention is more stable, and has higher toughness and strength; further, it indicates that the PET light-blocking bottle provided by the present invention is easier to blow-form, has a wider process window for blowing bottles, better molding, and the standing surface of the bottom foot is fuller at all angles, so the pre-blowing time and pressure can be appropriately reduced, and the bottle body pressure load is also more stable.

[0176] The applicant declares that the above is only a specific implementation mode 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 thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A light-blocking packaging product, characterized in that: In parts by weight, the light-blocking packaging product comprises 80 to 99.7 parts of a base material 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; The mass percentage of titanium dioxide in the light-blocking packaging product is less than 10%.

2. The light-blocking packaging product according to claim 1, characterized in that: The first polymer comprises at least one cycloaliphatic polyolefin and at least one aliphatic polyolefin; Preferably, the alicyclic polyolefin comprises a cycloolefin polymer; the aliphatic polyolefin comprises poly-4-methyl-1-pentene; Preferably, the mass ratio of the alicyclic polyolefin to the aliphatic polyolefin is (0.4-4.5):1, preferably (1.5-4):1; Preferably, the cycloolefin polymer comprises olefin and cycloolefin copolymer and / or cycloolefin polymer; Preferably, the titanium dioxide comprises rutile titanium dioxide.

3. The light-blocking packaging product according to claim 1 or 2, characterized in that: The base resin and the first polymer form a sea-island structure, the base resin constitutes a continuous phase, and the first polymer constitutes a dispersed phase; Preferably, the dispersed phase composed of the first polymer is a cake-shaped barrier phase; Preferably, the average diameter of the cake-shaped barrier phase is 0.5 to 40 μm, and the average thickness is 0.05 to 10 μm; Preferably, the ratio of the average diameter to the average thickness of the cake-shaped barrier phase is 1.2-100.

4. The light-blocking packaging product according to any one of claims 1 to 3, characterized in that: The light-blocking packaging product further comprises 0.02 to 6 parts of inorganic filler and / or 0.0002 to 1 part of metallic pigment in parts by weight; Preferably, the mesh size of the inorganic filler is 40 to 30,000 mesh; Preferably, the inorganic filler comprises at least one of calcined kaolin, calcite powder, silica powder, zinc oxide, barium sulfate, zinc sulfide or calcium carbonate; Preferably, the average particle size of the metallic pigment is 1 to 100 μm; Preferably, the metallic pigment comprises at least one of a metal element, a metal oxide or a metal alloy, and more preferably a metal element and / or a metal oxide; Preferably, the metal in the metallic pigment includes at least one of aluminum, iron, zinc, copper or silver, more preferably aluminum.

5. The light-blocking packaging product according to any one of claims 1 to 4, characterized in that: The light-blocking packaging product further comprises 0.0002 to 1 parts of a compatibilizer in parts by weight; Preferably, 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; Preferably, the light-blocking packaging product further comprises 0.0002 to 4 parts by weight of other additives; Preferably, the other auxiliary agents include at least one of a dispersant, a lubricant, an antioxidant, a heat absorbent, a light stabilizer, an antistatic agent or a colorant; Preferably, the substrate resin comprises 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 at least one of polyester, polycarbonate, polypropylene carbonate, polyamino acid, cellulose, thermoplastic starch, polyvinyl alcohol, chitosan, polyhydroxyalkanoate or thermoplastic elastomer; Preferably, the polyester comprises at least one of polyethylene terephthalate, glycol-modified polyethylene terephthalate, diacid-modified polyethylene terephthalate, polycyclohexanedimethanol terephthalate, glycol-modified polycyclohexanedimethanol terephthalate, diacid-modified polycyclohexanedimethanol terephthalate, copolyester of cyclohexanedimethanol and terephthalic acid, polybutylene terephthalate, polyethylene naphthalate, polylactide, polyhydroxyalkanoate, polybutylene adipate / terephthalate, polybutylene succinate, polybutylene succinate adipate, polycaprolactone, non-crystalline copolyester or polyarylate; Preferably, the thermoplastic elastomer comprises at least one of styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene copolymer, styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene copolymer, thermoplastic olefin, thermoplastic vulcanized rubber, thermoplastic polybutadiene, thermoplastic polyisoprene, thermoplastic polyvinyl chloride, thermoplastic chlorinated polyethylene, thermoplastic polyurethane elastomer, thermoplastic polyester elastomer, thermoplastic polyamide elastomer, thermoplastic fluoride or thermoplastic vulcanized silicone; Most preferably, the base resin is at least one of polyethylene terephthalate, glycol-modified polyethylene terephthalate, polylactide, polyhydroxyalkanoate, non-crystalline copolyester or polyarylate.

6. The light-blocking packaging product according to any one of claims 1 to 5, characterized in that: The light-blocking packaging product comprises at least one of an extrusion blow-molded product, an injection molded product, an injection blow-molded product, a compression molded product, a blister product, or an injection stretch blow-molded product; preferably, an injection stretch blow-molded product; Preferably, the light-blocking packaging product comprises a light-blocking bottle.

7. The light-blocking packaging product according to any one of claims 1 to 6, characterized in that: The light-blocking packaging product meets the following conditions: (1) The whiteness of the light-blocking packaging product is 80 to 100; and (2) The light transmittance of the light-blocking packaging product in the 550nm band is 0-2%.

8. A method for preparing a light-blocking packaging product according to any one of claims 1 to 7, characterized in that: The preparation method comprises: 80-99.7 parts of base resin, 0.1-12 parts of first polymer and 0.2-12 parts of titanium dioxide and optionally 0.02-6 parts of inorganic filler, 0.0002-1 parts of metal pigment, 0.0002-1 parts of compatibilizer and 0.0002-4 parts of other additives are formulated for molding the light-blocking packaging product.

9. The method for preparing the light-blocking packaging product according to claim 8, characterized in that: The components in the formula are directly added to the equipment for processing and forming, or are first extruded and granulated together with at least one other component, and the produced particles are then added to the equipment for processing and forming, or the produced particles are added to the equipment together with other formula components for processing and forming; Preferably, the molding method comprises subjecting the formulation to a first molding to obtain a parison or a preform; and then subjecting the parison or the preform to a second molding to obtain the light-blocking packaging product; Preferably, the first molding method includes at least one of extrusion molding, injection molding or compression molding; Preferably, the second molding method includes blow molding and / or vacuum molding.

10. The method for preparing the light-blocking packaging product according to claim 9, characterized in that: The molding method comprises extruding granulation and injection molding the formulation to obtain a parison or a preform; and then blow molding the parison or the preform to obtain the light-blocking packaging product; Preferably, the injection molding and blow molding include a two-step process and / or a one-step process.

11. The preparation method according to claim 10, characterized in that: The extrusion temperature is 250-300°C, and the injection molding temperature is 150-350°C; Preferably, the injection molding speed is 1 to 150 mm / s, and the injection pressure is 0.1 to 300 MPa; Preferably, the blow molding temperature is 50-260° C., the bottle blowing pressure is 5-100 bar, and the stretching speed of the stretching rod is 0.05-5 m / s.

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