Production method of single-ring-pipe ternary polymerization super-permeable material

Abstract

The invention belongs to the technical field of polyolefin materials, and particularly relates to a production method of a single-ring-pipe ternary polymerization super-permeable material. The single-ring-pipe ternary polymerization super-permeable material comprises a terpolymer and a compounding agent, the terpolymer is prepared from the following components in parts by weight: 1 to 3 parts of ethylene, 92 to 95 parts of propylene and 3 to 6 parts of butylene; the compounding agent comprises an anti-reflection nucleating agent, an antioxidant, glyceryl monostearate and calcium stearate. Impurities in ethylene, propylene and butylene raw materials are effectively removed through the refining unit, the refining capacity is high, and the production requirements of various polyolefin production processes can be met; the conversion rate of the single-loop-tube ternary polymerization reaction unit is high, ternary polymerization production conditions can be achieved, and meanwhile production of homopolymerization, angelica-free copolymerization and impact-resistant copolymerization is not affected. Compared with the traditional ethylene-propylene and propylene-butylene copolymerization, the rigidity and toughness are more balanced, and the application range of the product is expanded, especially the application to medical treatment, transparent products and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polyolefin materials, and particularly relates to a production method of a single-loop tube ternary copolymer super-permeable material. Background Art

[0002] Polypropylene is a commonly used thermoplastic with high impact resistance, strong mechanical properties, and resistance to a variety of organic solvents and acid and alkali corrosion. It is widely used in the industrial sector and is one of the most common polymer materials. However, the flexural modulus of traditional transparent polypropylene is difficult to exceed 1000 MPa, and the impact strength at room temperature is difficult to exceed 4.5 kJ / m 2 Impact performance reflects the toughness of polypropylene. The greater the impact, the better the toughness. However, the impact performance of polypropylene is inversely proportional to the flexural modulus. The better the impact performance, the lower the flexural modulus.

[0003] In existing technologies, the impact properties of polypropylene are often enhanced by increasing the butene and ethylene content. Furthermore, within a certain range, the higher the flexural modulus, the better the performance of polypropylene. However, the addition of certain levels of butene and ethylene will reduce the haze and flexural modulus of polypropylene. Precisely controlling the addition of ethylene and butene to maximize the flexural modulus without affecting the haze of polypropylene remains a key challenge facing polypropylene manufacturers. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for producing a single-loop tube ternary copolymer super-transparent material, thereby overcoming the shortcomings of the existing technology. This is achieved by using a third monomer, ethylene or butene. The present invention solves the problem of the rigidity and toughness balance of the product (both impact performance and flexural modulus are excellent) by adding the third and fourth monomers, ethylene and butene. The rigidity and toughness are more balanced than those of traditional ethylene-propylene and propylene-butene copolymers, thereby expanding the application range of the product, especially in applications such as medical treatment and transparent products.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] In a first aspect, the present invention provides a single-ring tube ternary copolymer super-permeable material, comprising a ternary copolymer and a compounding agent;

[0007] The terpolymer is composed of the following components by weight: 1-3 parts of ethylene, 92-95 parts of propylene, and 3-6 parts of butene;

[0008] The compounding agent includes a permeability enhancing nucleating agent, an antioxidant, glyceryl monostearate and calcium stearate;

[0009] The anti-transmission nucleating agent is 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonanol;

[0010] The antioxidants are antioxidant 1010 and antioxidant 168.

[0011] During the research process, the inventors found that compared with propylene-butane copolymer polypropylene, terpolymer polypropylene has higher room temperature impact and lower load deformation temperature, which is beneficial for downstream customers to reduce processing temperature and energy consumption. At the same time, the high room temperature impact can be applied to low temperature scenarios, which can reduce the addition and modification of POE.

[0012] Compared with EPDM copolymer, ternary copolymer polypropylene has higher flexural modulus and room temperature impact, better processing performance, and lower load deformation temperature, which is beneficial for downstream customers to reduce processing temperature and energy consumption.

[0013] In some other embodiments, the compounding agent is added in an amount of 3500-4800 ppm based on the mass of the terpolymer;

[0014] The compounding agent is composed of the following components: 1900-2500ppm of anti-transmission nucleating agent, 400-500ppm of antioxidant 1010, 900-1000ppm of antioxidant 168, 300-400ppm of glyceryl monostearate, and 300-400ppm of calcium stearate;

[0015] The molecular weight of the ternary copolymer super-transparent material is 300,000-350,000, the melt index is 36-40g / 10min, the haze is ≤9%, the flexural modulus is ≥1134MP; the notched impact strength of the simply supported beam measured at 23°C is ≥4.8kJ / m 2 .

[0016] In some other embodiments, the terpolymer is composed of the following components, in parts by weight: 1-2 parts of ethylene, 92-94 parts of propylene, and 4-6 parts of butene;

[0017] The amount of the compounding agent added is 4000-4300ppm of the mass of the terpolymer;

[0018] The compounding agent is composed of the following components: 1900-2000ppm of anti-transmission nucleating agent, 450-500ppm of antioxidant 1010, 950-1000ppm of antioxidant 168, 350-400ppm of glyceryl monostearate, and 350-400ppm of calcium stearate;

[0019] Preferably, the terpolymer is composed of the following components in parts by weight: 2 parts of ethylene, 93 parts of propylene, and 5 parts of butene;

[0020] The amount of the compounding agent added is 4300ppm of the mass of the terpolymer;

[0021] The compounding agent is composed of the following components: 2000 ppm of a permeability-enhancing nucleating agent, 500 ppm of an antioxidant 1010, 1000 ppm of an antioxidant 168, 400 ppm of glyceryl monostearate, and 400 ppm of calcium stearate.

[0022] In a second aspect, the present invention provides a method for producing the single-loop tube ternary copolymer super-permeable material according to the first aspect, comprising the following steps:

[0023] (1) Refining the raw materials ethylene, propylene and butene respectively to obtain refined ethylene, refined propylene and refined butene;

[0024] (2) mixing refined ethylene, refined propylene, and refined butene in the presence of a catalyst system and hydrogen to carry out copolymerization to produce a terpolymer;

[0025] (3) The ternary copolymer and the compounding agent are mixed and modified to obtain the ternary copolymer super-permeable material.

[0026] In some other embodiments, in step (2), the catalyst system is a titanium-based catalyst, the flow rate of the hydrogen is 2000-3000 ppm, and the mixing ratio of the refined ethylene, refined propylene and refined butene is (1-3):(92-95):(3-6);

[0027] The copolymerization reaction conditions are a temperature of 55-65°C and a reaction pressure of 3.8-4.2 MPa;

[0028] Preferably, the catalyst is titanium tetrachloride, the flow rate of the hydrogen is 2400 ppm, and the mixing ratio of the refined ethylene, refined propylene and refined butene is 2:93:5;

[0029] The copolymerization reaction conditions are a temperature of 60° C. and a reaction pressure of 4.0±0.1 MPa.

[0030] In some other embodiments, in step (3), the amount of the compounding agent added is 3500-4800 ppm of the mass of the terpolymer;

[0031] The modification treatment conditions are as follows: after mixing the terpolymer and the compounding agent, kneading at 170-220° C. for 2-3 hours, and then cooling and granulating.

[0032] In a third aspect, the present invention provides a production system for the single-loop ternary copolymer super-permeable material described in the first aspect, comprising a refining unit, a production unit, and a modification unit connected in sequence, wherein the production unit comprises a mixing feed tank, a prepolymerization reactor, a single-loop reactor, a medium-pressure degassing filter, a low-pressure degassing filter, a steamer, and a core dryer connected in sequence;

[0033] The mixed feed tank is connected to the discharge ports of ethylene, propylene and butene in the refining unit respectively.

[0034] In some other embodiments, the refining unit includes an ethylene refining unit, a propylene refining unit, and a butene refining unit;

[0035] Wherein, the ethylene refining device comprises a COS removal tower, an O2 removal tower, a CO removal tower, and an ethylene drying tower connected in sequence;

[0036] Or, the propylene refining device includes a free water separator, a COS removal tower, a light component removal tower, a propylene primary drying tower, a CO2 removal tower, a desulfurization, arsenic, phosphorus tower, and a propylene secondary drying tower connected in sequence;

[0037] Alternatively, the butene refining device includes a coalescer, a butene light component removal tower, a cooler, a butene drying tower, a filter, a butene feed tank, and a centrifugal pump connected in sequence; the centrifugal pump is used to transport a constant flow of butene to the propylene feed tank in the reaction unit, and transport excess butene back to the butene feed tank.

[0038] In some other embodiments, the modification unit includes a main silo, an additive silo, a mixing silo, an extruder, a centrifugal dryer, a separation screen, a blending silo, a pellet air flow conveying device, a packaging silo, and a collection silo;

[0039] The main material bin and the additive bin are connected to the mixing bin respectively, and the mixing bin is connected to the extruder, the centrifugal dryer, the separation screen, the blending bin, the pellet air flow conveying device, the packaging bin and the collection bin in sequence;

[0040] Preferably, the main silo is provided with at least one of a low level switch indicator, a low-low level switch indicator, a high level switch indicator, a high level switch indicator, and a load sensor level meter;

[0041] There is at least one additive bin and a mixing bin, and a meter is provided at the discharge port of the mixing bin; the meter is connected to a screw rod, and the screw rod is connected to an extruder;

[0042] Alternatively, the centrifugal dryer is connected to a pelletizing water tank, a pelletizing water filter is provided in the pelletizing water tank, the pelletizing water tank is connected to one end of a pelletizing water pump, and the other end of the pelletizing water pump is connected to the extruder;

[0043] Alternatively, the pellet air flow conveying device comprises an air delivery pipe, a buffer hopper and a pellet delivery rotary valve; the buffer hopper is connected to the pellet delivery rotary valve, and the discharge port and feed port of the buffer hopper are connected via an air delivery pipe;

[0044] There is at least one buffer hopper; the buffer hopper is connected to the blending bin; and an exhaust fan is provided on the buffer hopper.

[0045] In a fourth aspect, the present invention provides the use of the single-loop tube ternary copolymer super-transparent material described in the first aspect in the production of super-transparent polypropylene, preferably, in the production of medical syringes and food containers.

[0046] Beneficial effects of the present invention:

[0047] (1) In the present invention, in the reaction system of polypropylene, monomers ethylene and butene are added on the basis of propylene. In the presence of ethylene and butene, the molecular structure of the prepared terpolymer is randomly arranged, so that the rigidity and toughness balance of the prepared product (both impact performance and bending modulus are excellent) is more balanced than that of traditional EPDM and CPB copolymers.

[0048] (2) The present invention adds a transmittance-enhancing nucleating agent to the ternary copolymer and kneads the mixture, then keeps the mixture in a kneaded state and cools the mixture for granulation; this can effectively improve the light transmittance of the ternary copolymer, thereby increasing the transparency and reducing the haze of the ternary copolymer after granulation, while still maintaining good mechanical properties, thereby enriching the application of polypropylene in daily necessities and improving the competitiveness of polypropylene products.

[0049] (3) The production method of the present invention effectively removes impurities in ethylene, propylene and butene raw materials through the refining unit, has a strong refining ability, and can meet the production needs of various polyolefin production processes; the conversion rate of the single-loop tube ternary copolymerization reaction unit is high, which can achieve the ternary copolymerization production conditions, and at the same time does not affect the production of homopolymerization, random copolymerization and impact copolymerization.

[0050] (4) The production system of the present invention is flexible and convenient to operate, safe and reliable, with a high degree of automation, and has few moving equipment, a short construction period, and a compact layout. It can be constructed in a modular manner, which greatly reduces investment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0052] Figure 1 The refining units in the embodiment of the present invention are as follows: (a) is an ethylene refining unit, (b) is an olefin refining unit, and (c) is a butene refining unit;

[0053] Figure 2 The production unit in the embodiment of the present invention;

[0054] Figure 3 is a modification unit in the embodiment of the present invention;

[0055] Among them, COS removal tower (1-1), O2 removal tower (1-2), CO removal tower (1-3), ethylene drying tower (1-4);

[0056] Free water separator (2-1), COS removal tower (2-2), light component removal tower (2-3), propylene primary drying tower (2-4), CO2 removal tower (2-5), desulfurization, arsenic and phosphorus removal tower (2-6), propylene secondary drying tower (2-7);

[0057] Coalescer (3-1), butene light component removal tower (3-2), cooler (3-3), butene drying tower (3-4), filter (3-5), butene feed tank (3-6), centrifugal pump (3-7);

[0058] Pre-contact tank (4-1), propylene feed tank (4-2), prepolymerization reactor (4-3), R201 loop reactor (4-4), medium-pressure degassing filter (4-5), propylene condenser (4-6), low-pressure degassing filter (4-7), steamer (4-8), dryer (4-9), feeding hopper (4-10), propylene washing tower (4-11), mist separator (4-12), propylene gas circulation compressor (4-13), ethylene stripping tower (4-14);

[0059] Main material bin (1), additive bin (2), mixing bin (3), metering device (4), extruder (5), screw rod (6), centrifugal dryer (7), separation screen (8), blending bin (9), feeder (10), pelletizing water tank (11), pelletizing water pump (12), pelletizing air flow conveying system (13), buffer hopper (1301), pelletizing conveying rotary valve (1302), exhaust fan (14), collecting bin (15). DETAILED DESCRIPTION

[0060] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0061] The raw materials and reagents used in the following examples are all conventional commercially available products and can be purchased.

[0062] Example 1

[0063] A ternary copolymer super-permeable material, composed of the following components by weight: 2 parts of ethylene, 93 parts of propylene, and 5 parts of butene; the amount of the compounding agent added is 4300ppm of the mass of the ternary copolymer;

[0064] The compounding agent is composed of the following components: 2000 ppm of anti-transmission nucleating agent, 500 ppm of antioxidant 1010, 1000 ppm of antioxidant 168, 400 ppm of glyceryl monostearate, and 400 ppm of calcium stearate.

[0065] Refined ethylene, propylene, butene and catalyst are polymerized in a reactor and dried to obtain a ternary copolymer; the dried ternary copolymer and compounding agent are then placed in a granulator for mixing, melting, underwater pelletizing, dehydration, drying, blending and packaging to obtain a ternary copolymer super-transparent material.

[0066] Before adding the anti-transmittance nucleating agent, reduce the cylinder temperature to 210°C, the mold plate temperature to 205°C, and the pellet water temperature to 47°C. Close the start valve and throttle valve (these operating parameters should be fine-tuned according to actual working conditions). Before adding the compounding agent, empty the pelletizer. The anti-transmittance nucleating agent significantly affects the transmittance of the resin. When initially added, set the dosage to 2000ppm and monitor the cylinder pressure changes at all times. Adjust the pelletizer speed and cutter feed pressure promptly based on the on-site particle conditions to prevent blade entanglement or padding. When the melt index reaches 36g / 10min, the product is cut into the qualified bin. Control the final product melt index to 40±2g / 10min based on laboratory analysis data.

[0067] The physical properties of the prepared ternary copolymer super permeable material are shown in Table 1.

[0068] Table 1 Physical properties of ternary copolymer super permeable materials

[0069]

[0070]

[0071] Therefore, it can be seen from Table 1 above that the ternary copolymer super-transparent material prepared by the present invention has good solubility. The production method of the present application can improve the transmittance of the ternary copolymer super-transparent material, so that the brightness of the extruded and re-melted ternary copolymer super-transparent material is increased, the molecular structure of the ternary copolymer super-transparent material is improved, and at the same time, good mechanical properties are still maintained, which enriches the application of the ternary copolymer super-transparent material in daily necessities and improves the competitiveness of the ternary copolymer super-transparent material products.

[0072] Example 2

[0073] The difference from Example 1 is that the super-permeable terpolymer material is composed of the following components by weight: 2 parts of ethylene, 95 parts of propylene, and 3 parts of butene; the amount of the compounding agent added is 4000ppm of the mass of the terpolymer;

[0074] The compounding agent is composed of the following components: 1900 ppm of a transparent nucleating agent, 400 ppm of an antioxidant 1010, 900 ppm of an antioxidant 168, 400 ppm of glyceryl monostearate, and 400 ppm of calcium stearate.

[0075] The preparation method is exactly the same as that in Example 1.

[0076] The terpolymer has a melt index of 39.3 g / 10 min, a haze of 11%, and a flexural modulus of 1134 MP; the notched impact strength of the simple supported beam measured at 23°C is 6.8 kJ / m 2 .

[0077] Comparative Example 1

[0078] The difference from Example 1 is that no compounding agent is added to the components of the ternary copolymer super permeable material.

[0079] The preparation method is exactly the same as that in Example 1.

[0080] The terpolymer has a melt index of 53 g / 10 min, a haze of 45%, and a flexural modulus of 1024 MP; the notched impact strength of the simple supported beam measured at 23° C. is 5.8 kJ / m 2 .

[0081] Comparative Example 2

[0082] The difference from Example 1 is that, in the components of the ternary copolymer super-permeable material, only 2000 ppm of the anti-permeability nucleating agent is added to the compounding agent, and antioxidant 1010, antioxidant 168, glyceryl monostearate and calcium stearate are not added.

[0083] The preparation method is exactly the same as that in Example 1.

[0084] The terpolymer has a melt index of 54.5 g / 10 min, a haze of 10%, and a flexural modulus of 1121 MP; the notched impact strength of the simple supported beam measured at 23° C. is 5.6 kJ / m 2 .

[0085] Comparative Example 3

[0086] The difference from Example 1 is that in the components of the ternary copolymer super-transparent material, 2000 ppm of the anti-transmission nucleating agent and 500 ppm of the antioxidant 1010 are added to the compounding agent, and no antioxidant 168, glyceryl monostearate and calcium stearate are added.

[0087] The preparation method is exactly the same as that in Example 1.

[0088] The terpolymer has a melt index of 40.5 g / 10 min, a haze of 9%, and a flexural modulus of 1145 MP; the notched impact strength of the simple supported beam measured at 23° C. is 6.0 kJ / m2 .

[0089] Comparative Example 4

[0090] The difference from Example 1 is that in the components of the ternary copolymer super-permeable material, 2000 ppm of anti-permeability nucleating agent, 500 ppm of antioxidant 1010 and 1000 ppm of antioxidant 168 are added to the compounding agent, and glyceryl monostearate and calcium stearate are not added.

[0091] The preparation method is exactly the same as that in Example 1.

[0092] The terpolymer has a melt index of 39.5 g / 10 min, a haze of 8%, and a flexural modulus of 1134 MP; the notched impact strength of the simple supported beam measured at 23° C. is 6.8 kJ / m 2 .

[0093] Comparative Example 5

[0094] The difference from Example 1 is that in the components of the ternary copolymer super-transparent material, the compounding agent contains 2000 ppm of anti-transmission nucleating agent, 500 ppm of antioxidant 1010, 1000 ppm of antioxidant 168, and 400 ppm of glyceryl monostearate, but no calcium stearate is added.

[0095] The preparation method is exactly the same as that in Example 1.

[0096] The terpolymer has a melt index of 39.3 g / 10 min, a haze of 9%, and a flexural modulus of 1134 MP; the notched impact strength of the simple supported beam measured at 23° C. is 6.8 kJ / m 2 .

[0097] Example 3

[0098] A production system for a single-loop ternary copolymer super-permeable material used in Example 1 comprises a refining unit, a production unit, and a modification unit connected in sequence, wherein the production unit comprises a mixing feed tank, a prepolymerization reactor, a single-loop reactor, a medium-pressure degassing filter, a low-pressure degassing filter, a steamer, and a dryer connected in sequence;

[0099] Among them, the mixed feed tank is mixed with ethylene, propylene and butene in the refining unit respectively.

[0100] Figure 1 In the embodiment of the present invention, the refining unit includes an ethylene refining device, a propylene refining device and a butene refining device.

[0101] Figure 1 (a) is an ethylene refining device, which includes a COS removal tower (1-1), an O2 removal tower (1-2), a CO removal tower (1-3), and an ethylene drying tower (1-4) connected in sequence.

[0102] The refining process of the ethylene refining device is:

[0103] Ethylene from the boundary zone is fed into the COS removal tower (1-1) to remove PH3, AsH3, H2S, and COS. It is then heated to 90°C in a heat exchanger and fed into the O2 removal tower (1-2) to remove O2. After further purification in the CO removal tower (1-3), the discharged ethylene is first fed into a heat exchanger and cooled to 40°C before being fed to the ethylene drying tower (1-4). After leaving the ethylene drying tower (1-4), the ethylene is fed into a filter, filtered, and then fed into the reaction unit. When the ethylene is fed to the single-loop reactor in the reaction unit, it is compressed to the target pressure (5.0 MPa).

[0104] Figure 1 (b) is a propylene refining device, which includes a free water separator (2-1), a COS removal tower (2-2), a light component removal tower (2-3), a propylene primary drying tower (2-4), a CO2 removal tower (2-5), a desulfurization, arsenic and phosphorus removal tower (2-6), and a propylene secondary drying tower (2-7) connected in sequence.

[0105] The refining process of the propylene refining device is:

[0106] Fresh propylene from the boundary zone passes through a free water separator (2-1) to remove free water from the feedstock. The water separated in the free water separator (2-1) is first degassed in a water collection tank. The propylene exiting the free water separator (2-1) passes through a COS removal tower (2-2). The propylene exiting the COS removal tower (2-2) is heated to 45°C by a heater and then enters a light component removal tower (2-3). The propylene steam generated by the reboiler removes CO and other light component impurities. The propylene from the bottom of the light component removal tower is cooled by a heat exchanger, and the recovered heat is used to preheat the fresh propylene entering the light component removal tower. After passing through the heat exchanger and cooler, the propylene temperature is cooled to 40°C and sent to the propylene primary drying tower (2-4). After removing the monomer water, it enters the propylene CO2 removal tower (2-5), then enters the propylene desulfurization, arsenic and phosphorus removal tower (2-6), and finally enters the propylene secondary drying tower (2-7) to further remove the moisture in the raw material. After being filtered by the filter in the reaction unit, it enters the propylene feed tank (4-2).

[0107] Figure 1(c) is a butene refining device, which includes a coalescer (3-1), a butene light component removal tower (3-2), a cooler (3-3), a butene drying tower (3-4), a filter (3-5), a butene feed tank (3-6), and a centrifugal pump (3-7) connected in sequence; the centrifugal pump (3-7) is used to transport a constant flow of butene to the propylene feed tank in the reaction unit, and to transport excess butene back to the butene feed tank (3-6).

[0108] The refining process of the butene refining device is as follows:

[0109] Butene is fed from the coalescer (3-1) to the butene light ends removal tower (3-2). The butene light ends removal tower (3-2) operates at a pressure of 0.5 MPa. The bottoms stream from the butene light ends removal tower (3-2) is level-controlled and passed through a cooler (3-3) to the butene drying tower (3-4) to absorb moisture and ensure that the H2O content in the butene supplied to the polymerization section is less than 2 ppm. Butene-1 from the butene drying tower (3-4) is filtered by a filter (3-5) and then fed to the butene feed tank (3-6). The butene feed tank (3-6) is continuously fed with butene from the boundary zone. The butene feed tank (3-6) operates at a controlled pressure of 0.5 MPa. A centrifugal pump (3-7) transfers butene from the storage tank to the butene feed tank (3-6). To maintain a constant pressure in the discharge pipeline, the flow rate through the centrifugal pump (3-7) must be constant. The excess displacement of the centrifugal pump (3-7) is recycled back to the butene feed tank (3-6) after passing through the jacketed tube water cooler. The pressure of the butene feed tank (3-6) is maintained using a steam-heated tube heater.

[0110] Figure 2 The production unit in the embodiment of the present invention includes a propylene feed tank (4-2), a prepolymerization reactor (4-3), an R201 loop reactor (4-4), a medium-pressure degassing filter (4-5), a low-pressure degassing filter (4-6), a propylene washing tower (4-11), a mist separator (4-12), a propylene gas circulation compressor (4-13) and an ethylene stripping tower (4-14) connected in sequence; the feed port of the propylene feed tank (4-2) is connected to the propylene refining unit and the butene refining unit respectively; the reaction unit also includes a steamer (4-8), a dryer (4-9) and a feeding hopper (4-10) connected in sequence; the inlet of the steamer (4-8) is connected to the bottom outlet of the low-pressure degassing filter (4-7). A cooler is provided at the top of the propylene washing tower (4-11); a cooler is provided at the top of the stripping tower (4-14); and the low-pressure degassing filter (4-7) is a bag filter. The reaction unit further comprises a pre-contact tank (4-1); the pre-contact tank (4-1) is connected to the prepolymerization reactor (4-4).

[0111] The production process of the production unit is:

[0112] The catalyst slurry is pre-contacted and activated with TEAL (co-catalyst) and DONOR (electron donor) in a pre-contact tank (4-1); the main catalyst, DONOR and TEAL are respectively delivered to the pre-contact tank (4-1) by separate metering pumps. The pre-contact tank (4-1) is operated as a full tank. The main catalyst enters the pre-contact tank (4-1) through a separate bottom tube. The mixture after pre-contact is discharged to the prepolymerization reactor (4-2) by overflow to prevent the generation of bubbles.

[0113] In the ternary copolymerization production process, a propylene feed tank (4-2) continuously receives propylene from a propylene refining unit and butene from a butene unit, and the propylene and butene are mixed in a propylene feed tank (4-2) at a concentration ratio of 20:1, and then fed to a prepolymerization reactor (4-3) and an R201 loop reactor (4-4). After passing through the ethylene refining unit, the ethylene is pressurized to 5.0 MPa by a compressor and fed to the R201 loop reactor (4-4). The temperature of the R201 loop reactor (4-4) is controlled at 60°C, and the reaction pressure is 4.0±0.1 MPa.

[0114] After the reaction in the R201 loop reactor (4-4) is completed, the unreacted propylene, ethylene, and butene are discharged and separated. The slurry in the R201 loop reactor (4-4) is sent to the medium-pressure degassing filter (4-5) via a flash pipeline. When the system pressure of the medium-pressure degassing filter (4-5) drops from the pressure of 4.0 MPa in the R201 loop reactor (4-4) to 1.8 MPa in the medium-pressure degassing filter (4-5), propylene and butene are vaporized in the heating pipeline and the medium-pressure degassing filter (4-5). The steam pressure is adjusted to maintain the outlet gas temperature of the medium-pressure degassing filter (4-5) at 75°C. It is recovered to the propylene condenser (4-6) and pumped back to the propylene feed tank (4-2) by the propylene circulation pump.

[0115] The polymer collected from the bottom of the medium-pressure degassing filter (4-5) is discharged to the low-pressure degassing filter (4-7) under level control. The low-pressure degassing filter (4-7) is a bag filter that is automatically cleaned by reverse pulse of the process air flow. The air flow leaving the low-pressure degassing filter (4-7) is washed in a propylene washing tower (4-11) with a mixture of 50% paraffin oil and 50% atmer 163 to remove entrained powder and minimize the alkyl aluminum content entering the compressor, thereby producing a stable complex. The scrubbed propylene gas is cooled in the top cooler of the propylene scrubber (4-11) and then enters the entrainment separator (4-12). In the entrainment separator (4-12), the propylene gas is separated from the oil. The propylene and butene gases enter the propylene gas circulation compressor (4-13). After being pressurized in the propylene gas circulation compressor (4-13), they are sent to the ethylene stripper (4-14). The propylene and butene are separated in the ethylene stripper (4-14). The propylene separated at the top of the ethylene stripper (4-14) is cooled in a cooler and sent back to the propylene recovery tank (4-2) through the pressure difference. The butene at the bottom of the ethylene stripper (4-14) is sent to the refined butene tank.

[0116] The polypropylene powder from the bottom of the low-pressure degassing filter (4-7) enters the steamer (4-8) under the action of gravity. Two streams of low-pressure steam are introduced from the bottom of the steamer (4-8) to deactivate the residual catalyst and TEAL and remove residual hydrocarbons. The operating temperature of the steamer is 108-110°C, and the polymer is discharged to the dryer (4-9) by gravity under material level control. Hot nitrogen gas is blown upward from the porous distribution plate at the bottom of the dryer (4-9) under flow control. By controlling the flow rate of the gas, the wet polypropylene powder forms a fluidized bed in the dryer. Through the heat transfer effect between the hot nitrogen gas and the polymer, the hot nitrogen gas removes the moisture in the polymer.

[0117] The polypropylene (PP) powder from the dryer (4-9) is fed to the feeding hopper (4-10) through a rotary valve and then fed into the nitrogen pneumatic conveying line through a rotary valve. The dried polypropylene powder is conveyed to the powder buffer silo using compressed nitrogen provided by a nitrogen screw compressor.

[0118] According to the above analysis, the optimized process can achieve the production conditions of ternary copolymerization without affecting the production of homopolymerization, zero-return copolymerization and impact copolymerization.

[0119] Figure 3 The invention relates to a modification unit in an embodiment of the present invention; the modification unit comprises a main silo (1), an additive silo (2), a mixing silo (3), an extruder (5), a centrifugal dryer (7), a separation screen (8), a blending silo (8), a pellet air flow conveying device (13), a packaging silo and a collecting silo (15).

[0120] Wherein, the main silo (1) is used to receive the propylene-butane copolymer prepared by the reaction unit; preferably, the main silo (1) is provided with at least one of a low level switch indicator, a low-low level switch indicator, a high level switch indicator, a high level switch indicator, and a load sensor level meter, which can realize automatic control of the normal operation of the main silo;

[0121] The additive bin (2) is used to add solid additives, compounding agents, and transparency-enhancing nucleating agents, thereby increasing the transparency of the propylene-butadiene copolymer and obtaining a super-transparent propylene-butadiene copolymer material.

[0122] There is at least one of the additive bin (2) and the mixing bin (3), and a meter (4) is provided at the discharge port of the mixing bin (3); the meter (4) is connected to a screw rod (6), and the screw rod (6) is connected to an extruder (5);

[0123] The flow rate of the meter (4) can determine the flow rate of all additives (solid additives, compounding agents, and permeability-enhancing nucleating agents) in a preset ratio according to the formula and discharge them directly into the mixing chamber (3), thereby ensuring that the mixture prepared in the mixing chamber (3) is continuously added to the hopper of the extruder (5).

[0124] The centrifugal dryer (7) is connected to a pelletizing water tank (11), a pelletizing water filter is provided in the pelletizing water tank (11), the pelletizing water tank (11) is connected to one end of a pelletizing water pump (12), and the other end of the pelletizing water pump (12) is connected to an extruder (5).

[0125] The pellet air flow conveying device (13) comprises an air delivery pipe, a buffer hopper (1301) and a pellet delivery rotary valve (1302); the buffer hopper (1301) is connected to the pellet delivery rotary valve (1302), and the discharge port and feed port of the buffer hopper (1301) are connected via the air delivery pipe; the pellet delivery rotary valve (1302) is used to deliver the pellets in the buffer hopper (1301) into the air delivery pipe, so that the pellets are mixed in the buffer hopper (1301).

[0126] There is at least one buffer hopper (1301); the buffer hopper is connected to the blending bin (9); an exhaust fan (14) is provided on the buffer hopper (1301), and the exhaust fan (14) is used to blow the decomposed and volatilized gas in the buffer hopper (1301) into the collection bin (15).

[0127] The pellet air flow conveying device (13) can, on the one hand, enable the pellets to be statically mixed in the buffer hopper (1301) through the mixing pipe; on the other hand, it can deliver the pellets into the packaging silo through the pellet conveying rotary valve (1302), thereby ensuring the mixing effect.

[0128] The modification process of the propylene-butadiene copolymer is as follows:

[0129] The volume of the main silo (1) is about 1000m 3 The polymer flows from the main silo (1) into the powder metering screw feeder and continues to enter the polymer meter (4). When a short-term fault occurs in the downstream device, the main silo (1) continues to feed, usually with low material level control. The main silo (1) is equipped with vibration-type low level and low-low level (LAL-28003 and LALL-28004) and high level and high-high level switch indicators (LAH-8002 and LAHH-8001), and the load sensor level meter (WIA-8001) on the silo of the main silo (1) can provide information on the polymer powder content inside the main silo (1). The normal operating pressure of the main silo (1) is about 0.002MPa. The vent valve installed on the top of the main silo (1) releases pressure when the pressure reaches above 0.01MPa, and inputs air into the main silo (1) when the vacuum degree exceeds -0.0005MPa.

[0130] The polymer in the additive chamber (2) is transported to the mixing chamber (polymer / additive mixer). The flow rate of the meter (4) is usually determined by the flow rate of all additives (solid additives, compounding agents, and anti-transmission nucleating agents) according to the formula and the preset ratio. The additive dispensing unit discharges directly into the mixing chamber (3), and the mixture prepared in the mixing chamber is continuously added to the hopper of the extruder (5).

[0131] In the extruder (5), the mixed propylene copolymer powder is further evenly mixed with the added additives. The rotating screw shears the resin, converting mechanical energy into thermal energy to fully squeeze and melt the resin. The molten polymer is pushed toward the template. After the polymer emerges from the template holes in the form of strands, the rotating blades immediately cut it into pellets. The cut pellets are sent to the centrifugal dryer (7) by the circulating pelletizing water (desalted water), where the particles are separated from the water and dried. They are then sent to the separation screen (8) to separate the fine particles and coarse particles that do not meet the size requirements. Qualified pellets fall into the blending bin (9). The pelletizing water from the centrifugal dryer (7) is returned to the pelletizing water tank (11) through the pelletizing water filter and sent back to the pelletizing water pump (12) of the mixing bin for recycling in the pelletizing part of the extruder (5).

[0132] The pellet air flow conveying system (13) is used to convey the PP pellets from the lower discharge port of the buffer hopper (1301) to the upper feed port of the buffer hopper (1301) by air again, so that the pellets are statically mixed in the buffer hopper (1301) through the mixing pipe. The buffer hopper (1301) includes multiple buffer hoppers, and the multiple buffer hoppers (1301) are arranged in parallel. The buffer hopper (1301) is equipped with an exhaust fan (14), and the exhaust fan (14) is used to blow the gas volatilized by the product decomposition in the buffer hopper (1301) into a collection bin (15) equipped with a filter.

[0133] The pellets in the buffer hopper (1301) pass through the pellet conveying rotary valve (1302) and evenly enter the air conveying pipe of the air conveying system, thereby feeding the PP pellets into the buffer hopper (1301). Since the extruder (5) cannot guarantee that the quality of the same batch of pellet products produced at any moment is absolutely the same, in order to ensure the relative uniformity of the final product, a blending bin (9) and a pellet air conveying device (13) are provided. The pellet air conveying device (13) conveys the PP pellets from the lower outlet of the blending bin (9) to the upper feed port of the blending bin (9) again by air, so that the pellets are statically blended in the bin through the blending pipe. The circulating pellets sent by the pellet air conveying device (13) and the pellets sent by the air conveying system are automatically controlled and selected by the automatic control system to select the target bin so that they cannot enter the same buffer hopper pellet air conveying device (1301) at the same time.

[0134] When a product brand with a transparent nucleating agent is produced, the purge line at the bottom of the mixing bin (9) is connected, and the air sent in by the bin exhaust fan (14) blows the volatilized gas of the product decomposed in the mixing bin (9) into the collection bin (15) for filtration and then discharged into the atmosphere.

[0135] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A single-loop tube ternary copolymer super-permeable material, characterized in that: including terpolymers and compounding agents; The terpolymer is composed of the following components in parts by weight: 1-3 parts of ethylene, 92-95 parts of propylene, and 3-6 parts of butene; The compounding agent includes a permeability enhancing nucleating agent, an antioxidant, glyceryl monostearate and calcium stearate; The anti-transmission nucleating agent is 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonanol; The antioxidants are antioxidant 1010 and antioxidant 168.

2. The single-loop tube ternary copolymer super permeable material according to claim 1, characterized in that: The amount of the compounding agent added is 3500-4800ppm of the mass of the terpolymer; The compounding agent is composed of the following components: 1900-2500ppm of anti-transmission nucleating agent, 400-500ppm of antioxidant 1010, 900-1000ppm of antioxidant 168, 300-400ppm of glyceryl monostearate, and 300-400ppm of calcium stearate; The molecular weight of the ternary copolymer super-transparent material is 300,000-350,000, the melt index is 36-40g / 10min, the haze is ≤9%, the flexural modulus is ≥1134MP; the notched impact strength of the simply supported beam measured at 23°C is ≥4.8kJ / m 2 .

3. The single-loop tube ternary copolymer super permeable material as claimed in claim 1, characterized in that: The terpolymer is composed of the following components by weight: 1-2 parts of ethylene, 92-94 parts of propylene, and 4-6 parts of butene; The amount of the compounding agent added is 4000-4300ppm of the mass of the terpolymer; The compounding agent is composed of the following components: 1900-2000ppm of anti-transmission nucleating agent, 450-500ppm of antioxidant 1010, 950-1000ppm of antioxidant 168, 350-400ppm of glyceryl monostearate, and 350-400ppm of calcium stearate; Preferably, the terpolymer is composed of the following components in parts by weight: 2 parts of ethylene, 93 parts of propylene, and 5 parts of butene; The amount of the compounding agent added is 4300ppm of the mass of the terpolymer; The compounding agent is composed of the following components: 2000 ppm of a permeability-enhancing nucleating agent, 500 ppm of an antioxidant 1010, 1000 ppm of an antioxidant 168, 400 ppm of glyceryl monostearate, and 400 ppm of calcium stearate.

4. A method for producing the single-loop tube ternary copolymer super permeable material according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Refining the raw materials ethylene, propylene and butene respectively to obtain refined ethylene, refined propylene and refined butene; (2) mixing refined ethylene, refined propylene, and refined butene in the presence of a catalyst system and hydrogen to carry out copolymerization to produce a terpolymer; (3) The ternary copolymer and the compounding agent are mixed and modified to obtain the ternary copolymer super-permeable material.

5. The method for producing a super permeable material of a single-loop tube ternary copolymer as claimed in claim 4, wherein: In step (2), the catalyst system is a titanium-based catalyst, the flow rate of the hydrogen is 2000-3000 ppm, and the mixing ratio of the refined ethylene, refined propylene and refined butene is (1-3):(92-95):(3-6); The copolymerization reaction conditions are a temperature of 55-65°C and a reaction pressure of 3.8-4.2 MPa; Preferably, the catalyst is titanium tetrachloride, the flow rate of the hydrogen is 2400 ppm, and the mixing ratio of the refined ethylene, refined propylene and refined butene is 2:93:5; The copolymerization reaction conditions are a temperature of 60° C. and a reaction pressure of 4.0±0.1 MPa.

6. The method for producing a super permeable material of a single-loop tube ternary copolymer as claimed in claim 4, wherein: In step (3), the amount of the compounding agent added is 3500-4800 ppm of the mass of the terpolymer; The modification treatment conditions are as follows: after mixing the terpolymer and the compounding agent, kneading at 170-220° C. for 2-3 hours, and then cooling and granulating.

7. A production system for the single-loop tube ternary copolymer super-permeable material according to any one of claims 1 to 3, characterized in that: It includes a refining unit, a production unit and a modification unit connected in sequence, wherein the production unit includes a mixing feed tank, a prepolymerization reactor, a single loop reactor, a medium-pressure degassing filter, a low-pressure degassing filter, a steamer and a dryer connected in sequence; The mixed feed tank is connected to the discharge ports of ethylene, propylene and butene in the refining unit respectively.

8. The production system of single-loop tube ternary copolymer super permeable material as claimed in claim 7, characterized in that: The refining unit includes an ethylene refining device, a propylene refining device and a butene refining device; Wherein, the ethylene refining device comprises a COS removal tower, an O2 removal tower, a CO removal tower, and an ethylene drying tower connected in sequence; Or, the propylene refining device includes a free water separator, a COS removal tower, a light component removal tower, a propylene primary drying tower, a CO2 removal tower, a desulfurization, arsenic, phosphorus tower, and a propylene secondary drying tower connected in sequence; Alternatively, the butene refining device includes a coalescer, a butene light component removal tower, a cooler, a butene drying tower, a filter, a butene feed tank, and a centrifugal pump connected in sequence; the centrifugal pump is used to transport a constant flow of butene to the propylene feed tank in the reaction unit, and transport excess butene back to the butene feed tank.

9. The production system of single-loop tube ternary copolymer super-permeable material according to claim 7, characterized in that: The modification unit includes a main silo, an additive silo, a mixing silo, an extruder, a centrifugal dryer, a separation screen, a blending silo, a pellet air flow conveying device, a packaging silo and a collecting silo; The main material bin and the additive bin are connected to the mixing bin respectively, and the mixing bin is connected to the extruder, the centrifugal dryer, the separation screen, the blending bin, the pellet air flow conveying device, the packaging bin and the collection bin in sequence; Preferably, the main silo is provided with at least one of a low level switch indicator, a low-low level switch indicator, a high level switch indicator, a high level switch indicator, and a load sensor level meter; There is at least one additive bin and a mixing bin, and a meter is provided at the discharge port of the mixing bin; the meter is connected to a screw rod, and the screw rod is connected to an extruder; Alternatively, the centrifugal dryer is connected to a pelletizing water tank, a pelletizing water filter is provided in the pelletizing water tank, the pelletizing water tank is connected to one end of a pelletizing water pump, and the other end of the pelletizing water pump is connected to the extruder; Alternatively, the pellet air flow conveying device comprises an air delivery pipe, a buffer hopper and a pellet delivery rotary valve; the buffer hopper is connected to the pellet delivery rotary valve, and the discharge port and feed port of the buffer hopper are connected via an air delivery pipe; There is at least one buffer hopper; the buffer hopper is connected to the blending bin; and an exhaust fan is provided on the buffer hopper.

10. Use of the single-loop tube ternary copolymer super-transparent material according to any one of claims 1 to 3 in the production of super-transparent polypropylene, preferably in the production of medical syringes and food containers.

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