Ethylene-propylene-butylene ternary copolymer polypropylene resin and preparation method and application thereof

Abstract

The invention belongs to the field of polypropylene materials, and relates to ethylene-propylene-butylene ternary copolymerized polypropylene resin as well as a preparation method and application thereof. The method comprises the following steps: putting propylene, 1-butene and ethylene into a reactor, and carrying out polymerization reaction in the presence of a catalyst, a cocatalyst and an external electron donor, the ethylene-propylene-butylene ternary co-polypropylene is obtained by optimizing a catalyst-aid system and a reaction condition raw material formula; and blending the ethylene-propylene-butylene ternary copolymer polypropylene with a nucleating agent, a main antioxidant, an auxiliary antioxidant, an acid acceptor and a lubricant, carrying out melt mixing, and carrying out extrusion granulation to obtain the ethylene-propylene-butylene ternary copolymer resin. The haze of the ethylene-propylene-butylene ternary copolymer resin is about 8-9%, the melt index is more than 35g / 10min, the impact strength is about 6KJ / m < 2 >, and the bending modulus is about 900Mpa.

Description

Technical Field

[0001] The invention belongs to the technical field of polypropylene materials, and in particular relates to an ethylene-propylene-butylene terpolymer polypropylene resin and a preparation method and application thereof. Background Art

[0002] Polypropylene is a thermoplastic resin formed by the polymerization of propylene and other comonomers. It has the advantages of wide sources, moderate price, non-toxicity, good thermal stability and chemical stability, and good biocompatibility. It is widely used in the medical field. The transparent polypropylene products currently used are mainly EPDM copolymer polypropylene materials, but the introduction of ethylene will lead to a decrease in the flexural modulus of the product and an increase in the content of n-hexane extracts, which cannot meet the packaging requirements of food or medical supplies with high production hygiene requirements. Compared with ethylene, butene-1 has weaker competitive power and can be randomly dispersed on the polypropylene chain. The ternary random copolymer polypropylene has a smaller crystal size, and there is a difference in refractive index between the crystalline and amorphous regions, which reduces the haze and improves the transparency. At the same time, it has the characteristics of low xylene soluble content and good rigidity and toughness balance.

[0003] The Chinese invention patent with application publication number CN 109265594 A discloses terpolymer polypropylene of ethylene, propylene and butylene and its preparation method and application. Propylene, ethylene and butylene are placed in a reactor, and polymerization reaction is carried out in the presence of a catalyst, an alkyl aluminum cocatalyst and a silane modifier. During the polymerization reaction, H2 is introduced into the reactor to control the melt flow rate to obtain terpolymer polypropylene of ethylene, propylene and butylene. The catalyst used is a fourth-generation Ziegler-Natta catalyst, and the mass content of the component with a particle size greater than 900 μm is ≥50%. However, the catalyst belongs to a heterogeneous catalyst, which is TiCl4 loaded on active MgCl2 or other carriers. The electron donor is usually an aromatic acid diester such as diisobutyl phthalate, and the external electron donor is a silicide such as methylcyclohexyldimethoxysilane. During the polymerization of propylene, triethylaluminum reacts with the carboxyl group in phthalate, so that phthalate is easy to leave the catalyst surface. Phthalate can interfere with the endocrine system and has serious harm to human health.

[0004] At the same time, the application publication number CN 109265594 A does not disclose the transparency of the resin synthesized from the prepared ethylene-propylene-butylene terpolymer polypropylene; in addition, its impact resistance is poor, and it has a strong odor, a high content of n-hexane extract, and poor product quality, which cannot meet the hygiene requirements of food packaging, infant toys, medical supplies, etc. Summary of the invention

[0005] The purpose of the present invention is to provide an ethylene-propylene-butadiene ternary copolymer polypropylene resin and a preparation method and application thereof. The ethylene-propylene-butadiene ternary copolymer polypropylene resin with high melt index, high transparency and high impact resistance is synthesized by adopting a liquid phase reactor polymerization process, selecting an efficient catalyst-auxiliary agent system, controlling reaction conditions and optimizing the compounding agent formula. At the same time, the polypropylene resin has a haze of about 8-9%, a melt index of more than 35g / 10min and an impact strength of 6KJ / m 2 The bending modulus is about 900Mpa.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In the first aspect, an embodiment of the present invention provides an ethylene-propylene-butene terpolymer polypropylene, which is copolymerized by ethylene, propylene and 1-butene, wherein the mass ratio of propylene:1-butene:ethylene in the raw materials is (30-35):(3-4):(0.5-1.5); the content of 1-butene in the ethylene-propylene-butene terpolymer polypropylene is 3.9-5.6wt.%; and the content of ethylene is 0.9-2.5wt.%.

[0008] In a second aspect, an embodiment of the present invention provides a method for preparing an ethylene-propylene-butylene terpolymer polypropylene as described in the first aspect, comprising the following steps:

[0009] Propylene, 1-butene and ethylene are placed in a reactor and subjected to polymerization reaction in the presence of a catalyst, a co-catalyst and an external electron donor; during the polymerization reaction, H2 is introduced into the reactor to control the melt flow rate, thereby obtaining ethylene-propylene-butylene terpolymer polypropylene;

[0010] Wherein, the catalyst is SP-4 catalyst, ZN101-1 catalyst or CS-1 catalyst;

[0011] The co-catalyst is triethylaluminum, trimethylaluminum or methylaluminoxane;

[0012] The external electron donor is one or more of cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane and triethoxysilane.

[0013] In some other embodiments, the polymerization reaction conditions are 25-30° C., 4.0-4.5 MPa, prepolymerization for 10-15 min, then heating to 60-65° C., 3.0-3.2 MPa and continuing the reaction for 2-3 h.

[0014] In some other embodiments, high-purity nitrogen is introduced to purge the reactor for more than 2 hours before the polymerization reaction, and then replaced with gaseous propylene for more than three times to fill the reactor with a slight positive pressure.

[0015] In some other embodiments, the addition amount of each raw material is 150-175 g·L -1 , the amount of 1-butene added is 15 to 20 g·L -1 The amount of ethylene added is 2.5 to 7.5 g·L -1 The amount of the catalyst added is 2 to 2.5 mg·L -1 The amount of co-catalyst added is 0.5~0.7mmol·L -1 The amount of external electron donor added is 0.02~0.04mmol·L -1 .

[0016] In a third aspect, an embodiment of the present invention provides a method for preparing an ethylene-propylene-butadiene terpolymer polypropylene resin, comprising drying the ethylene-propylene-butadiene terpolymer polypropylene described in the first aspect, blending, melting, cooling, and pelletizing with a nucleating agent, a primary antioxidant, an auxiliary antioxidant, an acid absorber, and a lubricant;

[0017] Wherein, the nucleating agent is one or more of NX8000, dibenzylidene sorbitol, and 3,4-dimethylbenzylidene sorbitol. Preferably, the nucleating agent is NX8000;

[0018] The primary antioxidant is tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine or β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol;

[0019] The auxiliary antioxidant is tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite or tetrakis(2,4-di-tert-butylphenyl-4,4'-biphenyl)bisphosphonite;

[0020] The acid absorber is calcium stearate, talc or zinc stearate; preferably, the acid absorber is zinc stearate;

[0021] The lubricant is monoglyceride.

[0022] In some other embodiments, the weight parts of each raw material are: 100 parts of ethylene-propylene-butylene terpolymer polypropylene, 0.45-0.50 parts of nucleating agent, 0.1-0.5 parts of primary antioxidant, 0.2-0.5 parts of auxiliary antioxidant, 0.1-0.5 parts of acid absorbent, and 0.1-0.5 parts of lubricant.

[0023] In some other embodiments, the blending is to first mix the terpolymer polypropylene of ethylene, propylene and butylene with the nucleating agent, the primary antioxidant and the auxiliary antioxidant, and then add the acid absorber and the lubricant for secondary mixing;

[0024] Alternatively, a compound twin-screw extruder is used for melt mixing, the screw speed is 120-150r / min, the temperature is set as follows: the temperature of the first to third zones is 210-215°C, the temperature of the fourth to sixth zones is 200-205°C, the temperature of the seventh to eighth zones is 190-195°C, and the temperature of the head die is 180-185°C.

[0025] In a fourth aspect, an embodiment of the present invention provides an ethylene-propylene-butylene terpolymer polypropylene resin obtained by the preparation method described in the third aspect.

[0026] In a fifth aspect, an embodiment of the present invention provides the use of the ethylene-propylene-butylene terpolymer polypropylene resin described in the fourth aspect in high-temperature disinfection equipment, food packaging, infant toys, and medical materials.

[0027] The beneficial effects of the above embodiments of the present invention are as follows: DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] Example 1

[0030] S1, preparation of ethylene-propylene-butylene terpolymer polypropylene:

[0031] A 20L stainless steel automatic temperature-controlled high-pressure reactor was used for liquid phase bulk polymerization. The reactor temperature was 50°C. High-purity nitrogen was used to purge the reactor for more than 2 hours, and then it was replaced with gaseous propylene for more than three times, and the reactor was filled with a slight positive pressure.

[0032] Use a feeder to add 25 ml of triethylaluminum-hexane solution (0.5 mol / L), 7 ml of silane-hexane solution (0.1 mol / L) (70% cyclohexylmethyldimethoxysilane and 30% triethoxysilane), and 45 mg of SP-4 catalyst (purchased from Renqiu Lihe Technology Development Co., Ltd., with a titanium content of 1.5 to 5 wt.%) into the reaction kettle in sequence. After the addition is completed, the feeder is washed with hexane several times and added to the kettle.

[0033] Then, 8.2L hydrogen, 3500g liquid propylene, 350g 1-butene, and 100g ethylene were added to the reactor in sequence. After prepolymerization at 25°C and 4.0Mpa for 10 minutes, the temperature was raised to 65°C and the pressure was 3.2Mpa to continue the reaction for 2h. After the reaction was completed, stirring was stopped, excess gas was released, the temperature was lowered and the material was discharged to obtain ethylene-propylene-butene terpolymer powder.

[0034] S2, Drying:

[0035] The ethylene-propylene-butylene terpolymer powder prepared in S1 was dried in a vacuum drying oven at 60°C for 4 hours until the powder was completely dried.

[0036] S3, preparation of terpolymer polypropylene resin:

[0037] Take 100 parts of the dried terpolymer powder in S2, 0.45 parts of nucleating agent NX8000, 0.1 parts of primary antioxidant tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol, 0.2 parts of auxiliary antioxidant tri[2,4-di-tert-butylphenyl ester] phosphite, place in a high-speed mixer and stir at 1500r / min for 5 minutes to perform a primary blending; then, add 0.1 parts of acid absorber zinc stearate and 0.1 parts of monoglyceride to the powder after the primary blending, stir at 1800r / min for 5 minutes for a secondary blending to fully mix. Use a twin-screw extruder for melt mixing, cool the mixture in a water tank and granulate it with a pelletizer to obtain polypropylene composition pellets, and finally put the prepared pellets in an oven for use to obtain a terpolymer polypropylene resin.

[0038] Example 2

[0039] Different from Example 1, in S1 of Example 2, the amounts of propylene, ethylene and 1-butene added to the reactor are 3500 g of liquid phase propylene, 150 g of ethylene and 300 g of 1-butene.

[0040] The other preparation conditions are exactly the same as those in Example 1 and will not be repeated here.

[0041] Example 3

[0042] Different from Example 1, in S1 of Example 3, the amounts of propylene, ethylene and 1-butene added to the reactor are 3500 g of liquid propylene, 50 g of ethylene and 400 g of 1-butene.

[0043] The other preparation conditions are exactly the same as those in Example 1 and will not be repeated here.

[0044] Comparative Example 1

[0045] Different from Example 1, in S1 of Comparative Example 1, the catalyst is a fourth-generation Ziegler-Natta catalyst (a conventionally used organic metal catalyst, usually with MgCl2, SiO2, Al2O3, etc. as a catalyst carrier, the most commonly used being MgCl2 (i.e., MgCl2-supported ZN catalyst).

[0046] The other preparation methods are exactly the same as those in Example 1 and will not be repeated here.

[0047] Comparative Example 2

[0048] Different from Example 1, in S1 of Comparative Example 2, the catalyst is a CS-1 type catalyst (Institute of Chemistry, Chinese Academy of Sciences, with a titanium content of 2.5 wt.%).

[0049] The other preparation conditions are exactly the same as those in Example 1 and will not be repeated here.

[0050] Comparative Example 3

[0051] Different from Example 1, in S3 of Comparative Example 3, the external electron donor is 7 ml of cyclohexylmethyldimethoxysilane-hexane solution (0.1 mol / L).

[0052] The other preparation conditions are exactly the same as those in Example 1 and will not be repeated here.

[0053] Comparative Example 4

[0054] Different from Example 1, in S3 of Comparative Example 3, the external electron donor is 7 ml of triethoxysilane-hexane solution (0.1 mol / L).

[0055] The other preparation conditions are exactly the same as those in Example 1 and will not be repeated here.

[0056] 2. Performance Test

[0057] Test standard:

[0058] The melt index is tested according to GBT3682.1-2-2018, the flexural modulus is tested according to GB / T 9341-2008, the simply supported beam notched impact strength at room temperature (25°C) is tested according to GB / T1843.1-2008, and the haze is tested according to GB / T 2410-2008.

[0059] The test results of the terpolymer polypropylene resins prepared in Examples 1 to 3 and Comparative Examples 1 to 4 according to the above test standards are shown in Table 1.

[0060] Table 1 Measured properties of polypropylene resin

[0061]

[0062] As can be seen from Table 1, the ethylene-propylene-butylene terpolymer polypropylene resin prepared by using Examples 1 to 3 of the present invention has excellent comprehensive properties of high melt index, high transparency and high impact resistance. At the same time, the polypropylene resin has a haze of about 8 to 9%, a melt index of more than 35g / 10min, and an impact strength of 6KJ / m 2 The bending modulus is about 900Mpa.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An ethylene-propylene-butylene terpolymer polypropylene, characterized in that: The invention is prepared by copolymerization of ethylene, propylene and 1-butene, wherein the mass ratio of propylene:1-butene:ethylene in the raw materials is (30-35):(3-4):(0.5-1.5); the content of ethylene in the ethylene-propylene-butene terpolymer polypropylene is 0.9-2.5wt.%, and the content of 1-butene is 3.9-5.6wt.%.

2. A method for preparing the ethylene-propylene-butylene terpolymer polypropylene according to claim 1, characterized in that: The steps include: Propylene, 1-butene and ethylene are placed in a reactor and subjected to polymerization reaction in the presence of a catalyst, a co-catalyst and an external electron donor; during the polymerization reaction, H2 is introduced into the reactor to control the melt flow rate, thereby obtaining ethylene-propylene-butylene terpolymer polypropylene; Wherein, the catalyst is SP-4 catalyst, ZN101-1 catalyst or CS-1 catalyst; The co-catalyst is triethylaluminum, trimethylaluminum or methylaluminoxane; The external electron donor is one or more of cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane and triethoxysilane.

3. The preparation method according to claim 2, characterized in that: The polymerization reaction conditions are: prepolymerization at 25-30° C. and 4.0-4.5 MPa for 10-15 min, then heating to 60-65° C. and 3.0-3.2 MPa for further reaction for 2-3 h.

4. The preparation method according to claim 2, characterized in that: Before the polymerization reaction, high-purity nitrogen was introduced into the reactor to purge for more than 2 hours, and then replaced with gas-phase propylene for more than three times.

5. The preparation method according to claim 2, characterized in that: The addition amount of each raw material is 150-175 g·L of propylene. -1 , the amount of 1-butene added is 15 to 20 g·L -1 The amount of ethylene added is 2.5 to 7.5 g·L -1 The amount of the catalyst added is 2 to 2.5 mg·L -1 The amount of co-catalyst added is 0.5~0.7mmol·L -1 The amount of external electron donor added is 0.02~0.04mmol·L -1 .

6. A method for preparing an ethylene-propylene-butylene terpolymer polypropylene resin, characterized in that: The ethylene-propylene-butylene terpolymer polypropylene according to claim 1 is dried, blended with a nucleating agent, a primary antioxidant, an auxiliary antioxidant, an acid absorber, and a lubricant, melted, water-cooled, and pelletized; Wherein, the nucleating agent is one or more of NX8000, dibenzylidene sorbitol, and 3,4-dimethylbenzylidene sorbitol. Preferably, the nucleating agent is NX8000; The primary antioxidant is tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine or β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol; The auxiliary antioxidant is tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite or tetrakis(2,4-di-tert-butylphenyl-4,4'-biphenyl)bisphosphonite; The acid absorber is calcium stearate, talc or zinc stearate; preferably, the acid absorber is zinc stearate; The lubricant is monoglyceride.

7. The preparation method according to claim 6, characterized in that: The weight parts of the raw materials are as follows: 100 parts of ethylene-propylene-butylene terpolymer polypropylene, 0.45-0.50 parts of nucleating agent, 0.1-0.5 parts of primary antioxidant, 0.2-0.5 parts of auxiliary antioxidant, 0.1-0.5 parts of acid absorbent and 0.1-0.5 parts of lubricant.

8. The preparation method according to claim 6, characterized in that: The blending comprises firstly mixing the terpolymer polypropylene of ethylene, propylene and butylene with a nucleating agent, a primary antioxidant and an auxiliary antioxidant, and then adding an acid absorbent and a lubricant for secondary mixing; Alternatively, a compound twin-screw extruder is used for melt mixing, the screw speed is 120-150r / min, the temperature is set as follows: the temperature of the first to third zones is 210-215°C, the temperature of the fourth to sixth zones is 200-205°C, the temperature of the seventh to eighth zones is 190-195°C, and the temperature of the head die is 180-185°C.

9. An ethylene-propylene-butylene terpolymer polypropylene resin, characterized in that: The method is prepared according to any one of claims 6 to 8.

10. Use of the ethylene-propylene-butylene terpolymer polypropylene resin according to claim 9 in high-temperature disinfection equipment, food packaging, infant toys, and medical materials.

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