Enhanced plastic uptake meal box functional master batch and preparation method thereof

Abstract

The invention relates to the technical field of functional master batches, and provides an enhanced plastic uptake meal box functional master batch and a preparation method thereof, the enhanced plastic uptake meal box functional master batch comprises the following raw materials by weight: 30%-40% of polypropylene, 35%-50% of a heat-resistant oil-resistant agent, 15%-20% of a biodegradable agent, 2%-5% of a flexibilizer, 0.2%-1% of an anti-reflection agent and 0.5%-2% of a lubricant; the heat-resistant and oil-resistant agent is a compound of a high-temperature-resistant antioxidant and nano silicate. The plastic uptake lunch box solves the problem that an existing traditional plastic uptake lunch box is insufficient in transparency, durability, environment friendliness and the like.

Description

Technical Field

[0001] The invention relates to the technical field of functional masterbatches, and in particular to an enhanced blister lunch box functional masterbatch and a preparation method thereof. Background Art

[0002] With the rapid development of the food packaging industry, the requirements for lunch box materials are increasing. In a broad sense, blister lunch boxes refer to all blister shells. In a narrow sense, it is just a type of blister shell, that is, a sheet is blister-formed into a plastic box shape, and the cover is connected to the container. It is mostly made of PS, and there are also cases where the cover and the bottom are separated. Different materials can be selected, the bottom is made of black PS, and the cover is made of transparent PET. Traditional blister lunch boxes have deficiencies in transparency, durability, environmental protection, etc., and it is difficult to meet the market demand for high-quality packaging materials. Therefore, the development of a functional masterbatch that integrates multiple excellent properties is of great significance to improving the overall quality of blister lunch boxes. Summary of the invention

[0003] Therefore, in view of the above problems, the present invention provides an enhanced blister lunch box functional masterbatch and a preparation method thereof, which can significantly improve the transparency, toughness, heat resistance and oil resistance of the blister lunch box and the environmental protection and biodegradability.

[0004] To solve this technical problem, the present invention adopts the following scheme: an enhanced blister lunch box functional masterbatch, comprising the following raw materials in weight percentage: 30%-40% polypropylene, 35%-50% heat-resistant and oil-resistant agent, 15%-20% biodegradation agent, 2%-5% toughening agent, 0.2%-1% permeability enhancer and 0.5%-2% lubricant; the heat-resistant and oil-resistant agent is a high temperature resistant antioxidant and a nano-silicate composite.

[0005] Furthermore, in the composite of high temperature resistant antioxidant and nano silicate, the ratio of the high temperature resistant antioxidant to the nano silicate is 0.1-0.5:40-50.

[0006] Furthermore, the high temperature resistant antioxidant is one of 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene or 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and the particle size of the nanosilicate is between 40-50 nanometers.

[0007] Furthermore, the biodegradation agent is any one of corn starch, potato starch, wheat starch and sweet potato starch.

[0008] Furthermore, the toughening agent is ethylene-vinyl acetate copolymer or thermoplastic elastomer.

[0009] Furthermore, the permeability enhancer is an organosilicon compound or core-shell structured particles.

[0010] Furthermore, the lubricant is one or more of zinc stearate, calcium stearate, PE wax and N,N'-ethylene bisstearamide.

[0011] A method for preparing the above-mentioned enhanced blister lunch box functional masterbatch comprises the following process steps:

[0012] (1) Premixing of raw materials: polypropylene, toughening agent and lubricant are first placed in a low-speed mixer for preliminary mixing;

[0013] (2) Complete mixing: the premixed materials in step (1) are transferred into a high-speed mixer, the temperature is controlled at 110°C-120°C, and then the permeability enhancer, heat-resistant and oil-resistant agent and biodegradation agent are added in sequence and mixed thoroughly;

[0014] (3) Melt extrusion: The material mixed evenly in step (2) is fed into a twin-screw extruder, and the extrusion temperature of the twin-screw is controlled between 180-220° C. The molten material is extruded into strips through the die of the extruder and cooled and solidified through a cooling water tank. The cooled and solidified strips are then cut into uniform granular materials by a pelletizer to obtain functional masterbatch for blister lunch boxes.

[0015] By adopting the above technical solution, the beneficial effects of the present invention are:

[0016] 1. Add heat-resistant and oil-resistant agents to the functional masterbatch. An appropriate amount of high-temperature resistant antioxidants can resist oxidative degradation under high-temperature environments. High-temperature resistant antioxidants can capture and remove free radicals to prevent free radicals from attacking the molecular chains of materials, thereby extending the service life of the materials. Heat-resistant and oil-resistant fillers such as nanosilicates are introduced. Nanosilicates have high melting points, high thermal stability and good chemical stability, and can maintain the stability of materials under high temperature and oily environments. At the same time, the surface of nanosilicates carries some active functional groups (such as hydroxyl groups, carboxyl groups, etc.), which can react chemically with certain groups in the polypropylene resin matrix to form chemical bonds. This chemical bonding can enhance the interfacial bonding force between nanosilicates and the resin matrix, making the physical barrier more solid. In addition to chemical bonding, nanosilicates may also interact with the resin matrix through physical adsorption, which helps to form a stable physical barrier. When nanosilicate particles are evenly dispersed in the resin matrix, they can be nailed into the resin matrix like "nails" to form tiny physical barriers. These physical barriers can effectively block the penetration and diffusion of heat and grease, thereby improving the heat and oil resistance of the functional masterbatch. Nanosilicates also work synergistically with high-temperature resistant antioxidants to jointly improve the heat and oil resistance of the functional masterbatch. This synergistic effect can make up for the shortcomings of a single additive and achieve a more comprehensive performance improvement.

[0017] 2. Using organosilicon compounds or core-shell structured particles as transmittance enhancers can effectively reduce the scattering and absorption of light inside the material, thereby significantly improving the transparency of the blister lunch box. The high-transparency lunch box can more clearly display the food in the package, thereby enhancing consumers' purchasing desire and satisfaction.

[0018] 3. Using ethylene-vinyl acetate copolymer (EVA) or thermoplastic elastomer as a toughening agent dispersed in the resin matrix of polypropylene to form physical cross-linking points or network structures can effectively improve the flexibility and impact resistance of the blister lunch box. Even when subjected to external impact, the blister lunch box is not easy to break or deform, and better protects the food from damage.

[0019] 4. Biodegradable agents, such as starch-based materials, can be added to the functional masterbatch. These degradable ingredients can decompose quickly under certain conditions to reduce pollution to the environment. Blister lunch boxes made with functional masterbatches containing biodegradable agents can be processed by composting or other biodegradable methods after use, which helps promote the development of environmentally friendly food packaging materials and can be widely promoted and used. DETAILED DESCRIPTION

[0020] In order to further illustrate the present invention, the present invention is further described in conjunction with specific implementation modes.

[0021] Example 1

[0022] The enhanced blister lunch box functional masterbatch is calculated by weight percentage and weighs 30% PP resin (polypropylene), 50% heat-resistant and oil-resistant agent, 15% biodegradable agent, 4% toughening agent, 0.5% permeability enhancer and 0.5% lubricant.

[0023] Among them, the heat-resistant and oil-resistant agent is a high-temperature resistant antioxidant and nano-silicate complex, the ratio of which is 0.1:40, wherein the high-temperature resistant antioxidant is 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, the particle size of the nano-silicate is 40 nanometers, the biodegradable agent is corn starch, the permeability enhancer is an organosilicon compound, and the lubricant is zinc stearate.

[0024] The preparation method of enhanced blister lunch box functional masterbatch includes the following process steps:

[0025] (1) Premixing of raw materials: polypropylene, toughening agent and lubricant are first placed in a low-speed mixer for preliminary mixing;

[0026] (2) Complete mixing: the premixed materials in step (1) are transferred into a high-speed mixer, the temperature is controlled at 110°C-120°C, and then the permeability enhancer, heat-resistant and oil-resistant agent and biodegradation agent are added in sequence and mixed thoroughly;

[0027] (3) Melt extrusion: The material mixed evenly in step (2) is fed into a twin-screw extruder, and the extrusion temperature of the twin-screw is controlled between 180-220° C. The molten material is extruded into strips through the die of the extruder and cooled and solidified through a cooling water tank. The cooled and solidified strips are then cut into uniform granular materials by a pelletizer to obtain a functional masterbatch for a blister lunch box.

[0028] Example 2

[0029] The enhanced functional masterbatch for blister lunch boxes is prepared by weighing 32% PP resin, 45% heat-resistant and oil-resistant agent, 17% biodegradation agent, 3.8% toughening agent, 0.2% permeability enhancer and 2% lubricant in percentage by weight, mixing at low and high speeds, and then melt-mixing and extruding and granulating with a twin-screw extruder to obtain the enhanced functional masterbatch for blister lunch boxes.

[0030] The heat-resistant and oil-resistant agent is a high-temperature resistant antioxidant and a nano-silicate composite, the ratio of which is 0.1:45, wherein the high-temperature resistant antioxidant is 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and the particle size of the nano-silicate is 45 nanometers. The biodegradation agent is wheat starch, the permeability enhancer is an organic silicon compound, and the lubricant is calcium stearate.

[0031] The preparation method is the same as that in Example 1.

[0032] Example 3

[0033] The enhanced blister lunch box functional masterbatch is calculated by weighing 35% PP resin, 40% heat and oil resistant agent, 18% biodegradation agent, 5% toughening agent, 0.6% permeability enhancer and 1.4% lubricant in percentage by weight, mixing at low speed and high speed, and then melt-mixing and extruding granulation with a twin-screw extruder to obtain the enhanced blister lunch box functional masterbatch.

[0034] The heat-resistant and oil-resistant agent is a high-temperature resistant antioxidant and a nano-silicate composite, the ratio of which is 0.2:50, wherein the high-temperature resistant antioxidant is 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and the particle size of the nano-silicate is 50 nanometers. The biodegradable agent is potato starch, the permeability enhancer is an organic silicon compound, and the lubricant is N,N'-ethylene bisstearamide.

[0035] The preparation method is the same as that in Example 1.

[0036] Example 4

[0037] The enhanced functional masterbatch for blister lunch boxes is prepared by weighing 38% PP resin, 39% heat-resistant and oil-resistant agent, 19% biodegradation agent, 2% toughening agent, 0.8% permeability enhancer and 1.2% lubricant in percentage by weight, mixing at low and high speeds, and then melt-mixing and extruding and granulating with a twin-screw extruder to obtain the enhanced functional masterbatch for blister lunch boxes.

[0038] The heat-resistant and oil-resistant agent is a high-temperature resistant antioxidant and a nano-silicate composite, the ratio of which is 0.1:50, wherein the high-temperature resistant antioxidant is 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and the particle size of the nano-silicate is 48 nanometers. The biodegradable agent is sweet potato starch, the permeability enhancer is an organic silicon compound, and the lubricant is PE wax.

[0039] The preparation method is the same as that in Example 1.

[0040] Example 5

[0041] The enhanced functional masterbatch for blister lunch boxes is prepared by weighing 40% PP resin, 35% heat-resistant and oil-resistant agent, 20% biodegradable agent, 2.5% toughening agent, 1% permeability enhancer and 1.5% lubricant in percentage by weight, mixing at low and high speeds, and then melt-mixing and extruding and granulating with a twin-screw extruder to obtain the enhanced functional masterbatch for blister lunch boxes.

[0042] The heat-resistant and oil-resistant agent is a composite of a high-temperature resistant antioxidant and a nano-silicate, the ratio of which is 0.1:50, wherein the high-temperature resistant antioxidant is 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and the particle size of the nano-silicate is 42 nanometers. The biodegradable agent is corn starch, the permeability enhancer is an organic silicon compound, and the lubricant is a composite of zinc stearate and N,N'-ethylene bisstearamide, the ratio of which is 1:1.

[0043] The preparation method is the same as that in Example 1.

[0044] Comparative Example 1

[0045] The difference from Example 1 is that the high temperature resistant antioxidant is changed to tris(2,4-di-tert-butylphenyl) phosphite

[0046] Comparative Example 2

[0047] The difference from Example 1 is that the nano-silicate is replaced by ordinary talcum powder, and the particle size D50 of the talcum powder is 5.0 microns.

[0048] Comparative Example 3

[0049] The difference from Example 1 is that no toughening agent is added.

[0050] Comparative Example 4

[0051] The difference from Example 1 is that no permeation enhancer is added.

[0052] In order to test the effect of the enhanced blister lunch box functional masterbatch obtained in each embodiment, the functional masterbatch prepared in the above embodiments and PP resin were injection molded into relevant test specimens at a mass ratio of 2:8, and relevant performance tests were performed on them.

[0053] Performance test: Flexural strength and bending performance are carried out in accordance with IS0 178; impact strength test is carried out in accordance with IS0 180; heat deformation temperature test is carried out in accordance with IS0 1172; transparency test is carried out in accordance with IS0 13468-2; the test results are shown in Table 1.

[0054] Table 1

[0055]

[0056] As can be seen from the above table, compared with Comparative Examples 1 to 4, the specimens made of the enhanced blister lunch box functional masterbatch of Examples 1 to 5 have higher bending strength, bending modulus, impact strength, heat deformation temperature and transmittance when subjected to performance testing. This is mainly because Comparative Example 1 does not use a high-temperature resistant antioxidant, and the PP resin of the functional masterbatch is oxidized and degraded during the processing, which greatly reduces the effect of the obtained enhanced functional masterbatch, and the bending performance and heat resistance decrease significantly. Comparative Example 2 does not add nano-silicates, but ordinary talcum powder is used instead, the physical barrier effect deteriorates, and the heat resistance and transmittance also decrease significantly. Comparative Example 3 does not add a toughening agent, and the toughness decreases significantly. Comparative Example 4 does not add a transmittance enhancer, the optical properties of the masterbatch deteriorate, and the transmittance decreases significantly.

[0057] The enhanced blister lunch box functional masterbatch of the present invention is preferably composed of the following raw materials in weight percentage: 30%-40% polypropylene, 35%-50% heat-resistant and oil-resistant agent, 15%-20% biodegradation agent, 2%-5% toughening agent, 0.2%-1% permeability enhancer and 0.5%-2% lubricant; the heat-resistant and oil-resistant agent is a high temperature resistant antioxidant and a nano-silicate composite. The ratio of the high temperature resistant antioxidant to the nano silicate in the high temperature resistant antioxidant and nano silicate composite is preferably 0.1-0.5:40-50, the high temperature resistant antioxidant is preferably 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene or 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, the particle size of the nano silicate is preferably between 40 and 50 nanometers, the biodegradable agent can also be any one of corn starch, potato starch, wheat starch and sweet potato starch, the toughening agent is preferably ethylene-vinyl acetate copolymer or thermoplastic elastomer, the permeability enhancer is preferably organic silicon compound or core-shell structure particles, and the lubricant is preferably one or more of zinc stearate, calcium stearate, PE wax and N,N'-ethylene bisstearamide.

[0058] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. An enhanced blister lunch box functional masterbatch, characterized by: The material comprises the following raw materials in percentage by weight: 30%-40% polypropylene, 35%-50% heat-resistant and oil-resistant agent, 15%-20% biodegradation agent, 2%-5% toughening agent, 0.2%-1% permeability enhancer and 0.5%-2% lubricant; the heat-resistant and oil-resistant agent is a high-temperature resistant antioxidant and a nano-silicate composite.

2. The enhanced blister lunch box functional masterbatch according to claim 1, characterized in that: The ratio of the high temperature resistant antioxidant to the nano silicate in the high temperature resistant antioxidant and nano silicate composite is 0.1-0.5:40-50.

3. The enhanced blister lunch box functional masterbatch according to claim 2, characterized in that: The high temperature resistant antioxidant is one of 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene or 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and the particle size of the nano silicate is between 40 and 50 nanometers.

4. The enhanced blister lunch box functional masterbatch according to claim 1, characterized in that: The biodegradation agent is any one of corn starch, potato starch, wheat starch and sweet potato starch.

5. The enhanced blister lunch box functional masterbatch according to claim 1, characterized in that: The toughening agent is ethylene-vinyl acetate copolymer or thermoplastic elastomer.

6. The enhanced blister lunch box functional masterbatch according to claim 1, characterized in that: The permeability enhancer is an organosilicon compound or core-shell structure particles.

7. The enhanced blister lunch box functional masterbatch according to claim 1, characterized in that: The lubricant is one or more of zinc stearate, calcium stearate, PE wax and N,N'-ethylene bisstearamide.

8. A method for preparing the enhanced blister lunch box functional masterbatch according to any one of claims 1 to 7, characterized in that: The process steps include: (1) Premixing of raw materials: Put polypropylene, toughening agent and lubricant into a low-speed mixer for preliminary mixing; (2) Complete mixing: the pre-mixed materials in step (1) are transferred into a high-speed mixer, the temperature is controlled at 110°C-120°C, and then the permeability enhancer, heat-resistant and oil-resistant agent and biodegradation agent are added in sequence and mixed thoroughly; (3) Melt extrusion: The material mixed evenly in step (2) is fed into a twin-screw extruder. The extrusion temperature of the twin-screw is controlled between 180°C and 220°C. The molten material is extruded into strips through a die of the extruder and cooled and solidified through a cooling water tank. The cooled and solidified strips are then cut into uniform granular materials using a pelletizer to obtain functional masterbatch for blister lunch boxes.

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