Ternary polypropylene random copolymer resin as well as preparation method and application thereof

Abstract

The invention relates to the field of polypropylene materials, in particular to ternary copolymerized polypropylene resin as well as a preparation method and application thereof. The co-polypropylene resin comprises 97 to 99.6 parts by weight of a ternary random co-polypropylene resin base material, 0.1 to 0.3 part by weight of an antioxidant, 0.01 to 0.06 part by weight of a halogen absorbent, 0.1 to 0.3 part by weight of an anti-sticking agent and 0.1 to 0.2 part by weight of a slipping agent. The preparation method comprises the following steps: firstly mixing a part of the base material and the additive, preparing a mixture by a physical blending method or a melt blending method, adding the mixture into the residual base material, and after physical blending, feeding the mixture into an extruder for melt extrusion and granulation to obtain the ternary polypropylene random copolymer resin. The polypropylene resin has the characteristics of low initial melting temperature and melting point, excellent heat-sealing effect, high smoothness and the like, and is particularly suitable for improving the quality of special resin for low-temperature heat-sealing polypropylene.

Description

Technical Field

[0001] This invention relates to the field of polypropylene materials, specifically to a ternary random copolymer polypropylene resin, its preparation method, and its application. Background Technology

[0002] Ternary random copolymer polypropylene (hereinafter referred to as ternary polypropylene or ternary PP) is a polymer formed by the coordination anionic copolymerization of propylene, ethylene, and butene in a polymerization reactor under the action of a catalyst. The introduction of ethylene and butene comonomers disrupts the regularity of the polypropylene molecular chains, thereby reducing their crystallinity and lowering the polymer's melting temperature. As a heat-sealing layer for co-extruded films, ternary polypropylene has unique advantages, exhibiting a low initial heat-sealing temperature (100℃-115℃), high heat-sealing strength, a wide heat-sealing window, good resistance to boiling, and good low-temperature impact resistance. Ternary copolymer polypropylene is mainly used in polypropylene cast film (CPP), heat-shrinkable film (POF), and biaxially oriented polypropylene (BOPP).

[0003] With technological advancements, the production speed requirements for films are increasing. To meet the demands of high-speed packaging production lines, the heat-sealing layer of the film needs to improve its heat-sealing rate, which means minimizing the initial heat-sealing temperature and the final heat-sealing temperature. Currently, preparing a special resin for ternary random copolymer polypropylene heat-sealing films with low heat-sealing temperature and high heat-sealing strength remains a significant technical challenge.

[0004] In recent years, with people's pursuit of more refined and aesthetically pleasing packaging, higher requirements have been placed on the optical performance of films. Films need to have higher transparency, higher clarity, and lower haze. At the same time, many films have defects such as "crystal points" and "white spots" on their surfaces, which seriously affect the appearance, printing, heat sealing, and lamination performance of the films, resulting in a significant increase in scrap rate and a substantial reduction in product grade and price. This has now become a common problem and an urgent technical challenge to be solved in the PP film industry. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem that existing ternary random copolymer polypropylene heat-sealing film resins are difficult to simultaneously possess both low heat-sealing temperature and high optical performance. This invention provides a ternary random copolymer polypropylene resin with high optical performance and its preparation method. This resin and special preparation method enable the film material prepared by it to have low heat-sealing temperature, high heat-sealing strength and excellent optical performance.

[0006] The first aspect of this invention protects a ternary random copolymer polypropylene resin, wherein the ternary random copolymer polypropylene resin comprises: a ternary random copolymer polypropylene resin base, an antioxidant, a halogen absorbent, an anti-sticking agent, and a slip agent.

[0007] The anti-sticking agent is silicon dioxide;

[0008] The silica has a porosity ranging from 0 to 40% and a particle size ranging from 1 to 10 μm.

[0009] The aforementioned anti-sticking agent can improve the transparency of the obtained ternary random copolymer polypropylene film material, and can also effectively reduce the "white spots" and "crystal spots" defects of the obtained ternary random copolymer polypropylene film material, thereby improving the optical performance of the product. The polypropylene film material made from the ternary random copolymer polypropylene resin with the above-mentioned specific components can combine low heat-sealing temperature, high heat-sealing strength, and high optical performance.

[0010] In the ternary random copolymer polypropylene resin, the ternary random copolymer polypropylene resin base material is 97-99.6 parts by weight, antioxidant is 0.1-0.3 parts by weight, halogen absorber is 0.01-0.06 parts by weight, anti-sticking agent is 0.1-0.3 parts by weight, and slip agent is 0.1-0.2 parts by weight.

[0011] When the amounts of each component meet the above range, the stability, optical properties, and slip properties of the polypropylene material prepared by the composition can be further improved.

[0012] Preferably, in the ternary random copolymer polypropylene resin base, the content of structural units from propylene is 86wt%-95wt%, the content of structural units from butene is 4wt%-10wt%, and the content of structural units from ethylene is 1-4wt%.

[0013] Preferably, in the ternary random copolymer polypropylene resin base, the content of structural units from propylene is 89.5wt%-92wt%, the content of structural units from butene is 6wt%-8wt%, and the content of structural units from ethylene is 1.5-2.5wt%.

[0014] Preferably, at 230°C and a load of 2.16 kg, the melt flow rate of the ternary random copolymer polypropylene resin base is 1-10 g / 10 min; more preferably, it is 6-8 g / 10 min.

[0015] When the content of propylene, ethylene, and butene structural units and the melt flow rate range are met, the heat sealing temperature of the resin can be reduced, the transparency can be improved, and the number of crystal points can be reduced.

[0016] According to the present invention, the antioxidant includes hindered phenolic antioxidants and / or phosphite antioxidants.

[0017] According to the present invention, the halogen absorbent is selected from calcium stearate and / or hydrotalcite, preferably calcium stearate.

[0018] According to the present invention, the silicon dioxide is selected from at least one of SiO2 prepared by gas phase method, precipitation method, hydrothermal synthesis method, microemulsion reaction method, azeotropic distillation method, and supergravity reaction method, preferably by gas phase method or precipitation method.

[0019] Preferably, the silica has a porosity ranging from 0 to 30% and a particle size ranging from 3 to 6 μm.

[0020] Preferably, the slip agent is selected from fatty acids and fatty amides; more preferably, the fatty amide is one of ethylene bis-stearamide, erucamide, and oleamide; even more preferably, oleamide or erucamide;

[0021] Anti-sticking agents and slip agents can work synergistically to give the prepared ternary random copolymer polypropylene film material excellent slip properties.

[0022] A second aspect of this invention protects a method for preparing a ternary random copolymer polypropylene resin, wherein the preparation method comprises the following steps:

[0023] (1) A ternary random copolymer polypropylene resin base material was prepared by polymerization reaction of propylene, butene and ethylene;

[0024] (2) The anti-sticking agent and the first part of the ternary random copolymer polypropylene base material are physically mixed for the first time to form a premixed masterbatch. The premixed masterbatch is then physically mixed with antioxidant, halogen absorbent and slip agent to form an additive mixture.

[0025] (3) The remaining ternary random copolymer polypropylene base material and the additive mixture from step (2) are physically blended and then fed into an extruder for melt extrusion granulation to obtain the final product.

[0026] According to the present invention, in step (1), the weight ratio of propylene to butene is 5-10:1, preferably 5-7:1, and the weight ratio of propylene to ethylene is 15-40:1, preferably 25-35:1.

[0027] In this invention, when the amounts of propylene, butene, and ethylene meet the above-mentioned ranges, the polymerization reaction can proceed smoothly and stably, thereby giving the obtained ternary random copolymer polypropylene resin base material excellent heat-sealing and optical properties.

[0028] In this invention, the catalyst can catalyze and accelerate the reaction, adjust the molecular structure of the polymer, and optimize its mechanical and optical properties. The amount of catalyst used is not limited, as long as the catalytic performance is achieved.

[0029] In this invention, the catalyst is a conventional Ziegler-Natta (ZN) catalyst in the field of polyolefins, preferably the commercially available LyondellBasell ZN101-1 catalyst.

[0030] The co-catalyst can be selected from commonly used co-catalysts in the art. Preferably, the co-catalyst is alkyl aluminum, preferably at least one of triethylaluminum, diethylaluminum chloride, triisobutylaluminum and diethylaluminum chloride, and more preferably triethylaluminum.

[0031] The external electron donor can be selected from commonly used external electron donors in the art. Preferably, the external electron donor is at least one of carboxylic acid ester external electron donors, alkoxysilane external electron donors, and ammonia external electron donors, and more preferably an alkoxysilane external electron donor. More preferably, the alkoxysilane external electron donor includes at least one of cyclohexylmethyldimethoxysilane (CHMMS, Donor C), dicyclopentyldimethoxysilane (DCPMS, Donor D), diisopropyldimethoxysilane (DIPMS, Donor P), and diisobutyldimethoxysilane (DIBMS, Donor B), and more preferably dicyclopentylmethyldimethoxysilane.

[0032] In step (1), the conditions for the polymerization reaction include: a polymerization temperature of 65-85℃, a polymerization time of 1-3h, a polymerization pressure of 2-4MPa, and a hydrogen concentration of 1-5mol% during the polymerization reaction; preferably, the conditions for the polymerization reaction include: a polymerization temperature of 65-75℃, a polymerization time of 1-1.5h, a polymerization pressure of 2-2.5MPa, and a hydrogen concentration of 1-2mol% during the polymerization reaction.

[0033] In this invention, the carrier gas includes hydrogen, nitrogen, and unreacted propylene, butene, and ethylene.

[0034] Preferably, the weight ratio of the anti-sticking agent to a portion of the ternary random copolymer polypropylene powder base material in step (2) is 1:1-10, more preferably 1:1-5.

[0035] Preferably, the granulation in step (3) includes gas-solid separation of the ternary random copolymer polypropylene resin base product obtained in the reactor to obtain a solid product and a carrier gas, and then granulation after mixing the solid product with the additives.

[0036] In this invention, the preparation method of the additive mixture in step (2) can also be: physically mixing a portion of the ternary random copolymer polypropylene base material, anti-sticking agent, antioxidant, halogen absorbent, and slip agent, and then melt-extruding and granulating; preferably, the melt extrusion is performed using a twin-screw extruder, and the extrusion temperature is 160-180℃; preferably, the weight ratio of the anti-sticking agent to the first portion of the ternary random copolymer polypropylene powder base material is 1:1-10, more preferably 1:1-5.

[0037] This invention utilizes the adsorption and dispersion effects of spherical porous base material by adding a portion of the base material during processing. In particular, the anti-sticking agent migrates into the pores of the base material, forming a micro-scale dispersion and mixing effect. This ensures good compatibility with the overall base material resin and other additives, resulting in a ternary random copolymer polypropylene film that combines low heat-sealing temperature, high heat-sealing strength, and high optical performance.

[0038] The final objective of this invention is to protect the use of the above-described ternary random copolymer polypropylene resin or the ternary random copolymer polypropylene resin prepared by the above method in the heat-sealing layer of polyolefin heat shrink film or polypropylene cast film.

[0039] The beneficial effects of this invention are:

[0040] (1) The polypropylene film material made from the ternary random copolymer polypropylene resin of specific components in this invention can have the characteristics of low heat sealing temperature, high heat sealing strength and high optical performance.

[0041] (2) The specific reactants, anti-sticking agents, slip agents and composite additives in the preparation method enable the final ternary random copolymer polypropylene resin material to have both excellent heat-sealing performance and high transparency and low crystal point optical properties. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0043] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0044] The present invention will be described in detail below through embodiments.

[0045] Example 1

[0046] A method for preparing a ternary random copolymer polypropylene resin includes the following steps:

[0047] (1) Preparation of ternary random copolymer polypropylene resin base material: The main catalyst, co-catalyst, external electron donor, hydrogen, propylene, butene and ethylene were fed into a gas phase multi-zone reactor for random copolymerization reaction to obtain ternary random copolymer polypropylene resin base material. The flow rate of the main catalyst ZN101-1 was 1.35 kg / h, the flow rate of the co-catalyst triethylaluminum was 5 kg / h, and the flow rate of the external electron donor cyclohexyl-methyl-dimethoxysilane was 0.5 kg / h, so that the flow rate ratio of triethylaluminum to cyclohexyl-methyl-dimethoxysilane was 10. The pressure of the gas phase reactor was 2 MPa, the temperature was 68℃, the H2 concentration was 4 mol%, and the total amount of propylene, ethylene and butene was used as the basis. The amount of propylene was 89.5 wt%, the amount of ethylene was 2.5 wt%, the amount of butene was 8 wt%, and the reaction time was 1.5 h to obtain ternary random copolymer polypropylene resin base material.

[0048] (2) Preparation of additive mixture: The above-mentioned ternary random copolymer polypropylene resin base material is subjected to gas-solid separation of solid product and carrier gas. The carrier gas is recycled after compression and separation. The solid product is mixed with the composite additive and then granulated. The composition and preparation process of the composite additive are as follows: Take an appropriate amount of the above-mentioned ternary random copolymer polypropylene resin base material and mix it with an anti-sticking agent for the first time to form a premixed masterbatch. The weight ratio of the anti-sticking agent to the ternary random copolymer polypropylene base material is 1:3. The anti-sticking agent is SiO2. The SiO2 is synthesized by gas phase method, with a porosity of about 30% and a particle size of about 6μm. Then, the premixed masterbatch is mixed with antioxidant B215, calcium stearate and erucamide for the second time to form the composite additive. The mass ratio of premixed masterbatch: antioxidant: halogen absorber: slip agent is 4:1:0.1:0.6.

[0049] (3) The ternary random copolymer polypropylene resin base material of step (1) is mixed with the additive mixture of step (2) and then melt-granulated. The amount of the composite additive is 9500mg per kilogram of ternary random copolymer polypropylene powder, to obtain ternary random copolymer polypropylene resin.

[0050] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0051] Example 2

[0052] The ternary random copolymer polypropylene resin base was prepared using a method similar to that in Example 1, except that the type of anti-sticking agent in step (2) was changed, and the rest of the process was the same. The anti-sticking agent was SiO2, which was prepared by precipitation method, with a porosity of about 0% and a particle size of about 4μm.

[0053] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0054] Example 3

[0055] The ternary random copolymer polypropylene resin base was prepared using a method similar to that in Example 1, except that: in step (1), based on the total amount of propylene, ethylene and butene, the amount of propylene was 87 wt%, the amount of ethylene was 3 wt%, and the amount of butene was 10 wt%; in step (2), the mass ratio of each component in the composite additive was changed to a mass ratio of premixed masterbatch (the weight ratio of anti-sticking agent to ternary random copolymer polypropylene was 1:1): antioxidant: halogen absorbent: slip agent of 2:1:0.1:0.6; and the amount of the composite additive was 6500 mg per kilogram of ternary random copolymer polypropylene powder.

[0056] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0057] Example 4

[0058] The ternary random copolymer polypropylene resin was prepared using a method similar to that in Example 1, except that the preparation method of the composite additive was changed in step (2). The composite additive in Example 1 was prepared by physical blending, while the composite additive in Example 4 was prepared by melt granulation. The specific preparation process was as follows: an appropriate amount of the above-mentioned ternary random copolymer polypropylene resin base material was taken and physically mixed with antioxidant B215, calcium stearate, silica, and erucamide, and then melt extruded and granulated to form the composite additive. The mass ratio of ternary random copolymer polypropylene resin base material: antioxidant B215: calcium stearate: silica: erucamide was 4:1:0.1:1:0.6. The melt extrusion was a conventional operation in the art, carried out by a twin-screw extruder at an extrusion temperature of 170°C.

[0059] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0060] Example 5

[0061] Ternary random copolymer polypropylene resin was prepared using a method similar to that in Example 4, except that: in step (1), based on the total amount of propylene, ethylene and butene, the amount of propylene was 87 wt%, the amount of ethylene was 3 wt%, and the amount of butene was 10 wt%; in step (2), the type of anti-sticking agent SiO2 was changed, the anti-sticking agent was Japanese Mizusawa JC-30, the porosity was about 0%, and the particle size was about 3 μm; the slip agent component was changed to erucamide; at the same time, in step (2), the mass ratio of each component in the composite additive was changed, specifically the mass ratio of ternary random copolymer polypropylene resin base material: antioxidant B215: calcium stearate: JC30: erucamide was 1:1:0.1:1:0.5.

[0062] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0063] Example 6

[0064] Ternary random copolymer polypropylene resin was prepared using a method similar to that in Example 1. The difference was that in step (2), the composition and preparation method of the composite additives were changed. The composite additives did not contain ternary random copolymer polypropylene powder base material. Therefore, the composite additives consisted of antioxidant B215, calcium stearate, silica, and erucamide. The mass ratio of antioxidant B215:calcium stearate:silica:erucamide in the composite additives was 1:0.1:1:0.6. The preparation method involved physically blending the above additive components and then feeding them into a single-screw extruder for dry extrusion granulation. The screw temperature was 100°C.

[0065] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0066] Example 7

[0067] Ternary random copolymer polypropylene resin was prepared using a method similar to that in Example 1. The difference was that in step (2), the composition and preparation method of the composite additive were changed. The composite additive did not contain ternary random copolymer polypropylene powder base material. Therefore, the composite additive components were antioxidant B215, calcium stearate, silica, and erucamide. The mass ratio of antioxidant B215:calcium stearate:silica:erucamide in the composite additive was 1:0.1:1:0.6. The preparation method involved physically blending the above additive components to obtain the composite additive.

[0068] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0069] Comparative Example 1

[0070] Ternary random copolymer polypropylene resin was prepared using a method similar to that in Example 1, except that the type of anti-adhesive was changed. The anti-adhesive component was SiO2, which was synthesized by a gas-phase method. The porosity was about 70%, and the particle size was about 9 μm.

[0071] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0072] Comparative Example 2

[0073] Ternary random copolymer polypropylene resin was prepared using a method similar to that in Example 1. The difference was that in step (1), propylene, butene, and hydrogen were introduced into the reactor for polymerization. Based on the total amount of propylene, ethylene, and butene, the amount of propylene was 89.5 wt%, the amount of ethylene was 1.2 wt%, and the amount of butene was 5 wt%. Meanwhile, in step (2), the anti-sticking agent was SiO2, which was synthesized by precipitation method, with a porosity of approximately 0% and a particle size of approximately 8 μm.

[0074] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0075] Comparative Example 3

[0076] Ternary random copolymer polypropylene resin was prepared using a method similar to that in Example 1, except that in step (1), the polymerization reaction was carried out in the presence of hydrogen (H2 was used to adjust the polymer melt index), and the H2 concentration was 1 mol%.

[0077] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0078] Comparative Example 4

[0079] Ternary random copolymer polypropylene resin was prepared using a method similar to that in Example 1, except that in step (2), the proportion and total amount of composite additives were changed. The composite additives consisted of a premixed masterbatch (the weight ratio of anti-sticking agent to ternary random copolymer polypropylene was 1:1): antioxidant: halogen absorbent: slip agent in a mass ratio of 8:1:0.1:0.6. The ternary random copolymer polypropylene resin base material and the composite additives were mixed and then melt-granulated. The amount of the composite additives was 12500 mg per kilogram of ternary random copolymer polypropylene powder.

[0080] The contents of ethylene, propylene and butene structural units in the ternary random copolymer polypropylene resin obtained in step (2) and their melt index at 230℃ and 2.16kg load are shown in Table 1.

[0081] The melting point, melt flow rate, and ethylene butene content of the ternary random copolymer polypropylene resins obtained in the above examples and comparative examples were tested, and the results are shown in Table 1. Simultaneously, the resins obtained in the examples and comparative examples were cast into films, and the number of crystal points, number of white points, transparency, and heat-sealing temperature of the films were further tested, and the results are shown in Table 2.

[0082] Table 1. Properties of the ternary random copolymer polypropylene resins prepared in Examples 1-5 and Comparative Examples 1-6

[0083]

[0084]

[0085] Table 2 shows the property analysis of the resin films after casting in Examples 1-5 and Comparative Examples 1-6.

[0086]

[0087]

[0088] The test method for melt flow rate is GB / T 3682.1-2018 Determination of melt mass flow rate (MFR) of thermoplastics, Part 1; the test conditions include: test temperature of 230℃ and weight mass of 2.16 kg. The melting point is determined by differential scanning spectroscopy. The test methods for butene content and ethylene content are high-temperature 13C NMR tests, using dichlorodeuterated benzene as the solvent, at a temperature of 120℃ and a magnetic field frequency of 400 MHz. The test methods for the number of crystal points (fisheyes) and white spots are in accordance with GB / T-6595.

[0089] The initial heat-sealing temperature was tested using the method described in GB / T 27740-2011 for cast polypropylene (CPP) films. Haze and clarity were tested according to GB / T2410 standard, with a sample thickness of 30 μm. The specific test method involved measuring the scattered light flux (lma) that deviated more than 2.5° from the incident light direction after passing through the sample; the transmitted light flux was recorded as lmb. Haze = lma / lmb × 100%. All tests were performed on parallel samples, with 5 sets tested and the average value calculated.

[0090] As can be seen from Table 1, the ternary random copolymer polypropylene resin of the present invention has the characteristics of low crystal point, low white point, low melting point, low initial heat sealing temperature, and high transparency.

[0091] Examples 6 and 7 illustrate that if the preparation method of the composite additive is changed, and no ternary copolymer polypropylene powder base is added to the composite additive, and the composite additive is prepared by one-step physical blending or single-screw extrusion granulation, although the haze, clarity and heat sealing temperature do not change significantly, the number of crystal points and white points will increase.

[0092] Comparing Example 1 and Comparative Example 1, it can be seen that using SiO2, an anti-sticking agent with unsuitable particle size and porosity, significantly increases the number of crystal points and white spots in the ternary random copolymer polypropylene resin, resulting in deteriorated optical properties. Comparative Example 2 shows that low ethylene and butene content increases the melting point and significantly raises the heat-sealing temperature. Comparative Example 3 shows that a low polymer melt index leads to an increase in the number of crystal points, with little change in the number of white spots, while simultaneously increasing haze and deteriorating optical properties. Comparative Example 4 shows that changes in the proportion and amount of composite additives lead to an increase in the number of crystal points and white spots, an increase in heat-sealing temperature, an increase in haze, and a deterioration in optical properties.

[0093] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A ternary random copolymer polypropylene resin, characterized in that, The ternary random copolymer polypropylene resin comprises: ternary random copolymer polypropylene resin base, antioxidant, halogen absorbent, anti-sticking agent, and slip agent; the anti-sticking agent comprises silica. The silica has a porosity ranging from 0 to 40% and a particle size ranging from 1 to 10 μm.

2. The terpolymer random copolymer polypropylene resin according to claim 1, characterized in that, In the ternary random copolymer polypropylene resin, the ternary random copolymer polypropylene resin base material is 97-99.6 parts by weight, antioxidant is 0.1-0.3 parts by weight, halogen absorber is 0.01-0.06 parts by weight, anti-sticking agent is 0.1-0.3 parts by weight, and slip agent is 0.1-0.2 parts by weight.

3. The terpolymeric random copolymer polypropylene resin according to claim 1 or 2, characterized in that, In the ternary random copolymer polypropylene resin base, the content of structural units from propylene is 86wt%-95wt%, the content of structural units from butene is 4wt%-10wt%, and the content of structural units from ethylene is 1-4wt%. Preferably, the content of structural units from propylene is 89.5 wt%-92 wt%, the content of structural units from butene is 6 wt%-8 wt%, and the content of structural units from ethylene is 1.5-2.5 wt%.

4. The terpolymer random copolymer polypropylene resin according to claim 1 or 2, characterized in that, At 230°C and a load of 2.16 kg, the melt flow rate of the ternary random copolymer polypropylene resin is 4-10 g / 10 min; preferably 6-8 g / 10 min.

5. The terpolymer random copolymer polypropylene resin according to claim 1 or 2, characterized in that, The antioxidants include hindered phenolic antioxidants and / or phosphite antioxidants; And / or, the halogen absorber is calcium stearate and / or hydrotalcite; And / or, the silica is selected from at least one of SiO2 prepared by gas phase method, precipitation method, hydrothermal synthesis method, microemulsion reaction method, azeotropic distillation method, and supergravity reaction method, preferably by gas phase method or precipitation method; Preferably, the silica has a porosity ranging from 0-30% and a particle size of 3-6 μm; And / or, the slip agent is selected from fatty acids and fatty amides; preferably, the fatty amide is one of ethylene bis-stearamide, erucamide, and oleamide; further, the fatty amide is oleamide or erucamide; And / or, the weight ratio of the anti-sticking agent to the slip agent is 1-2:1, preferably 1-1.5:

1.

6. A method for preparing the ternary random copolymer polypropylene resin according to any one of claims 1-5, characterized in that, Includes the following steps: (1) A ternary random copolymer polypropylene resin base material was prepared by polymerization reaction of propylene, butene and ethylene; (2) The anti-sticking agent and the first part of the ternary random copolymer polypropylene base material are physically mixed for the first time to form a premixed masterbatch. The premixed masterbatch is then physically mixed with antioxidant, halogen absorbent and slip agent to form an additive mixture. (3) The remaining ternary random copolymer polypropylene base material and the additive mixture from step (2) are physically blended and then fed into an extruder for melt extrusion granulation to obtain the final product.

7. The production method according to claim 6, wherein The conditions for the polymerization reaction in step (1) include: a polymerization temperature of 65-85℃, a polymerization time of 1-3h, a polymerization pressure of 2-4MPa, and a hydrogen concentration of 1-5mol% during the polymerization reaction; based on the total amount of propylene, ethylene, and butene, the amount of propylene is 82-93.5wt%, the amount of ethylene is 1.5-6wt%, and the amount of butene is 5-12wt%.

8. The preparation method according to claim 6, characterized in that, In step (2), the weight ratio of the anti-sticking agent to the first part of the ternary random copolymer polypropylene powder base is 1:1-10, more preferably 1:1-5.

9. The preparation method according to claim 6, characterized in that, The preparation method of the additive mixture in step (2) can also be as follows: physically mixing the first part of ternary random copolymer polypropylene base material, anti-sticking agent, antioxidant, halogen absorbent and slip agent, and melt extruding and granulating; preferably, the melt extrusion adopts a twin-screw extruder and the extrusion temperature is 160-180℃; preferably, the weight ratio of anti-sticking agent to the first part of ternary random copolymer polypropylene powder base material is 1:1-10, more preferably 1:1-5.

10. The application of the ternary random copolymer polypropylene resin according to any one of claims 1-5 or the ternary random copolymer polypropylene resin prepared by the method according to any one of claims 6-9 in the heat-sealing layer of polyolefin heat shrink film or polypropylene cast film.

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