A modified random copolymer polypropylene toughened impact polypropylene material

Abstract

The application discloses a modified random copolymer polypropylene toughened impact polypropylene material, which is prepared from polyethylene grafted modified random copolymer polypropylene masterbatch, impact polypropylene and an antioxidant as raw materials, uniformly mixing the three, and then extruding and granulating to obtain modified random copolymer polypropylene toughened impact polypropylene material particles; then the particles are dried and injection molded. The modified polypropylene masterbatch containing long ethylene segments and long propylene segments improves the compatibility of the components of the raw materials, and can form a eutectic crystal with homopolymer polypropylene, so that the rigidity and toughness of the obtained impact polypropylene material are improved to a certain extent, and the toughening method is beneficial to the rigidity and toughness balance performance of the impact polypropylene.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polypropylene, and particularly relates to a modified random copolymer polypropylene toughened impact polypropylene material and a preparation method thereof. BACKGROUND

[0002] Impact polypropylene (ICP) is a kind of polypropylene with complex multi-phase structure, which has a wide application in the fields of household appliances, daily necessities, new energy vehicles, etc. In recent years, with the proposal of the concept of automobile lightweight, "plastic instead of steel" has become the direction of the development of the automobile industry, and the rapid development of new energy vehicles has greatly increased the demand for impact polypropylene, and more and more enterprises have invested in the development of impact polypropylene. In recent years, the research direction of impact polypropylene includes in-situ kettle polymerization method for introducing ethylene-propylene copolymer to prepare impact polypropylene and melt blending method for adding elastomer to improve the toughness of polypropylene.

[0003] Patent CN 105504524B discloses a high-impact polypropylene special material and a preparation method thereof. The special material uses ultra-fine silicon dioxide and liquid ternary ethylene-propylene rubber to form core-shell structure particles with liquid ternary ethylene-propylene rubber as the shell and ultra-fine silicon dioxide as the core, uses polypropylene and ethylene-octene copolymer to prepare elastomer-modified polypropylene by screw extrusion, and melts and extrudes the core-shell structure particles, the elastomer-toughened modified polypropylene, and the antioxidant to obtain the high-impact polypropylene special material. This modification method greatly improves the dispersion performance of ultra-fine silicon dioxide while playing a toughening effect, and the ethylene-octene copolymer and the core-shell structure particles simultaneously play a synergistic toughening effect on the polypropylene matrix, so that the prepared special material has excellent impact and tensile properties.

[0004] Patent CN 116715922A discloses a high-rigidity high-impact polypropylene resin and a preparation method thereof. The method uses propylene monomer, hydrogen, and electron donor to polymerize homopolymer polypropylene, then adds ethylene monomer, isopropyl alcohol, and triethylaluminum to generate copolymer polypropylene, and adds rigidifying nucleating agent, antioxidant, toughening agent, and acid absorbent during the extrusion and granulation stage to obtain the high-rigidity high-impact polypropylene resin. The impact polypropylene resin prepared by the method is polymerized from propylene monomer and ethylene monomer under the action of a prepolymerization catalyst, has good interphase compatibility, and has good rigidity and toughness balance.

[0005] The melt blending method has the advantages of simple process by introducing elastomers to improve the impact resistance of polypropylene, but also has the disadvantages of uneven dispersion of the blend, high cost and poor batch stability; the impact polypropylene obtained by the in-reactor copolymerization method is suitable for large-scale industrial production and has stable product performance, but due to the limitation of the structure of the product by the catalyst and the process, the flexibility of the structure regulation is relatively low, and some impact polypropylene products will have the problem of poor compatibility between the matrix phase and the dispersed phase due to the difficulty in regulating the content of the block copolymer, which finally leads to poor impact performance of the product.

[0006] In order to solve the above problems, the present application combines the advantages of the melt blending method and the in-reactor copolymerization method, and provides a method for toughening impact copolymer polypropylene using modified random copolymer polypropylene, which uses low-density polyethylene as a grafting monomer to melt graft modify random copolymer polypropylene to obtain polyethylene grafted modified polypropylene masterbatch, and then melt blends the masterbatch with impact copolymer polypropylene to obtain modified impact copolymer polypropylene. The toughening method is beneficial to improve the toughness problem of the material caused by the insufficient block copolymer part and the poor compatibility of the two phases in the structure of the impact copolymer polypropylene, further improves the rigidity and toughness balance of the impact copolymer polypropylene, and expands its application field. SUMMARY

[0007] In order to improve the compatibility of the low block copolymer impact polypropylene and further improve the impact toughness of the impact polypropylene, the present application provides a modified random copolymer polypropylene toughened impact polypropylene material and a preparation method thereof.

[0008] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0009] A modified random copolymer polypropylene toughened impact polypropylene material is made from the following raw materials by mass fraction: polyethylene grafted modified random copolymer polypropylene masterbatch 10-20 parts, impact polypropylene 80-90 parts, antioxidant 1-2 parts.

[0010] Further, the polyethylene grafted modified random copolymer polypropylene masterbatch is uniformly mixed with random copolymer polypropylene, linear low-density polyethylene and initiator in a high-speed mixer, and then melt extruded in a twin-screw extruder, and then cooled, pulled and cut to obtain.

[0011] Further, the raw materials used are as follows by mass fraction: random copolymer polypropylene 50-70 parts, linear low-density polyethylene 30-50 parts, and initiator 0.05-0.1 parts.

[0012] Further, the random copolymer polypropylene has an ethylene content of 3-7%, a melting point of 130-170℃ and a melt index of 1-10g / 10min.

[0013] Further, the melt index of the linear low density polyethylene is 10-50 g / 10 min.

[0014] Further, the initiator is one of DHBP (2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane), BPO (dibenzoyl peroxide), and DCP (dicumyl peroxide).

[0015] Further, the temperature of each temperature section of the twin-screw extruder is 160-200 ℃, and the rotating speed is 60-100 rpm.

[0016] Further, the melt index of the impact polypropylene is 1-10 g / 10 min; the content of xylene-soluble matter in the impact polypropylene is 20-30%, the content of xylene-insoluble matter is 70-80%, and the content of ethylene in the xylene-insoluble matter is 1-4%.

[0017] Further, the antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, and antioxidant 626.

[0018] Further, the preparation steps of the modified random copolymerized polypropylene toughened impact polypropylene material are as follows:

[0019] (1) melt blending: uniformly mixing the polyethylene grafted modified random copolymerized polypropylene master batch, the impact polypropylene, and the antioxidant, and placing them in a twin-screw extruder to perform melt blending, and then performing traction cooling and pelletizing to obtain particles with uniform size;

[0020] (2) sample drying: placing the particles obtained in step (1) in a blast drying oven to perform drying treatment;

[0021] (3) injection molding: using an injection molding machine to injection mold the particle samples obtained in step (2) into standard samples.

[0022] Further, the temperature of each temperature section of the twin-screw extruder in step (1) is 180-230 ℃, and the rotating speed is 60-100 rpm.

[0023] Further, the temperature of the drying in step (2) is 60-100 ℃, and the time is 1-3 h.

[0024] Further, the temperature of each temperature section of the injection molding machine in step (3) is 170-230 ℃, the holding pressure is 30-80 bar, the holding time is 40 s, and the mold temperature is 40 ℃.

[0025] The present application has the following beneficial effects:

[0026] The application provides a modified random copolymer polypropylene toughened impact polypropylene material, which introduces modified polypropylene masterbatch containing long ethylene segments and long propylene segments into impact polypropylene as a compatibilizer of a base phase and a dispersed phase of the impact polypropylene material, so that a good interface is formed; meanwhile, the modified polypropylene masterbatch can form a eutectic with the base phase homopolymer polypropylene in the impact polypropylene, so that the toughness and modulus of the obtained impact polypropylene material are increased to different degrees, thereby widening the application field of the impact polypropylene material. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The infrared spectrogram of the polyethylene grafted modified random copolymer polypropylene masterbatch prepared in examples 1-3. DETAILED DESCRIPTION

[0028] A modified random copolymer polypropylene toughened impact polypropylene material, the preparation steps of which are as follows:

[0029] 1) 50-70 parts of random copolymer polypropylene, 30-50 parts of linear low density polyethylene and 0.05-0.1 parts of an initiator are uniformly mixed in a high-speed mixer, and then added into a twin-screw extruder, the temperature of each temperature section is set to 160-200 ℃, and the rotating speed is set to 60-100 rpm for melt extrusion, and then the polyethylene grafted modified random copolymer polypropylene masterbatch is prepared through cooling, traction and cutting;

[0030] 2) 10-20 parts of the modified polypropylene masterbatch prepared in step 1), 80-90 parts of impact polypropylene and 1-2 parts of an antioxidant are uniformly mixed, and then placed in a twin-screw extruder, the temperature of each temperature section is set to 180-230 ℃, and the rotating speed is set to 60-100 rpm for melt blending, and then the uniformly sized particles are prepared through traction cooling and granulation;

[0031] 3) the particles obtained in step 2) are placed in a blast drying oven and dried at 60-100 ℃ for 1-3 h;

[0032] 4) the particle sample obtained in step 3) is injection molded into a standard sample by using an injection molding machine, setting the temperature of each temperature section to 170-230 ℃, the holding pressure to 30-80 bar, the holding time to 40 s and the mold temperature to 40 ℃.

[0033] In step 1), the ethylene content of the random copolymer polypropylene is 3-7%, the melting point is 130-170 ℃, and the melt index is 1-10 g / 10 min. The melt index of the linear low density polyethylene is 10-50 g / 10 min. The initiator is one of DHBP (2,5-dimethyl-2,5-bis(tert-butyl peroxy) hexane), BPO (dibenzoyl peroxide) and DCP (dicumyl peroxide).

[0034] The melt index of the impact polypropylene in step 2) is 1-10 g / 10 min; the xylene soluble content of the impact polypropylene is 20-30%, the xylene insoluble content is 70-80%, and the ethylene content in the xylene insoluble is 1-4%. The antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, or antioxidant 626.

[0035] In order to make the content of the application more convenient to understand, the technical solutions of the application are further described below in combination with specific embodiments, but the application is not limited thereto.

[0036] In the examples, the experimental methods used are conventional methods unless otherwise specified; the materials, reagents, etc. used are commercially available unless otherwise specified.

[0037] Example 1

[0038] 1) According to parts by mass, uniformly mix 70 parts of random copolymerized polypropylene, 30 parts of linear low-density polyethylene, and 0.05 parts of DCP initiator in a high-speed mixer, add them into a twin-screw extruder, set the temperature of each temperature section to 160, 180, 195, 200, 200, 200, 200, 190, and 160 ℃, and the rotation speed to 70 revolutions / minute for melt extrusion, then cool, pull, and cut the material to obtain polyethylene grafted modified random copolymerized polypropylene masterbatch.

[0039] 2) Take 15 parts of the above-mentioned grafted modified random copolymerized polypropylene masterbatch, uniformly mix it with 85 parts of impact polypropylene, 0.5 parts of antioxidant 1010, and 1 part of antioxidant 168, place it in a twin-screw extruder, set the temperature of each temperature section to 180, 200, 220, 230, 230, 230, 230, 210, and 180 ℃, and the rotation speed to 100 revolutions / minute for secondary melt blending, then pull, cool, and cut the material to obtain uniformly sized particles.

[0040] 3) Place the obtained particles in a blast drying oven, dry them at 70 ℃ for 2 h, then transfer them to an injection molding machine, set the temperature of each temperature section to 170, 190, 210, and 230 ℃, the mold temperature to 40 ℃, and the holding pressure to 60 bar for 40 s to obtain standard samples.

[0041] Example 2

[0042] 1) By mass parts, the random copolymer polypropylene 60 parts, linear low density polyethylene 40 parts, DCP initiator 0.05 parts are uniformly mixed in a high-speed mixer, added into a twin-screw extruder, the temperature of each temperature section is set to 160, 180, 195, 200, 200, 200, 200, 190, 160 ℃, and the rotating speed is 70 revolutions / minute for melt extrusion, then cooled, pulled, and cut into pieces to prepare the polyethylene grafted modified random copolymer polypropylene master batch.

[0043] 2) Take the above grafted modified random copolymer polypropylene master batch 15 parts, mix with impact polypropylene 85 parts, antioxidant 1010 0.5 parts, antioxidant 168 1 part uniformly, put into a twin-screw extruder, set the temperature of each temperature section to 180, 200, 220, 230, 230, 230, 230, 210, 180 ℃, and the rotating speed to 100 revolutions / minute for secondary melt blending, then pulled, cooled, and cut into particles to prepare particles with uniform size.

[0044] 3) The prepared particles are placed in a blast drying oven, dried at 70 ℃ for 2h, then transferred to an injection molding machine, the temperature of each temperature section is set to 170, 190, 210, 230, 230 ℃, the mold temperature is 40 ℃, and the pressure is kept for 40s under 60 bar pressure to obtain standard samples.

[0045] Example 3

[0046] 1) By mass parts, the random copolymer polypropylene 60 parts, linear low density polyethylene 40 parts, DCP initiator 0.05 parts are uniformly mixed in a high-speed mixer, added into a twin-screw extruder, the temperature of each temperature section is set to 160, 180, 195, 200, 200, 200, 200, 190, 160 ℃, and the rotating speed is 70 revolutions / minute for melt extrusion, then cooled, pulled, and cut into pieces to prepare the polyethylene grafted modified random copolymer polypropylene master batch.

[0047] 2) Take the above grafted modified random copolymer polypropylene master batch 15 parts, mix with impact polypropylene 85 parts, antioxidant 1010 0.5 parts, antioxidant 168 1 part uniformly, put into a twin-screw extruder, set the temperature of each temperature section to 180, 200, 220, 230, 230, 230, 230, 210, 180 ℃, and the rotating speed to 100 revolutions / minute for secondary melt blending, then pulled, cooled, and cut into particles to prepare particles with uniform size.

[0048] 3) The prepared particles are placed in a blast drying oven, dried at 70 ℃ for 2h, then transferred to an injection molding machine, the temperature of each temperature section is set to 170, 190, 210, 230, 230 ℃, the mold temperature is 40 ℃, and the pressure is kept for 40s under 60 bar pressure to obtain standard samples.

[0049] Example 4

[0050] 1) According to the mass fraction, the random copolymer polypropylene 60 parts, linear low density polyethylene 40 parts, DCP initiator 0.05 parts are uniformly mixed in a high-speed mixer, added into a twin-screw extruder, the temperature of each temperature section is set to 160, 180, 195, 200, 200, 200, 200, 190, 160 ℃, and the rotating speed is 70 revolutions / minute for melt extrusion, and then cooled, pulled, and cut to prepare polyethylene grafted modified random copolymer polypropylene master batch.

[0051] 2) Take the above grafted modified random copolymer polypropylene master batch 10 parts, mix with impact polypropylene 90 parts, antioxidant 1010 0.5 parts, antioxidant 168 1 part uniformly, put into a twin-screw extruder, set the temperature of each temperature section to 180, 200, 220, 230, 230, 230, 230, 210, 180 ℃, and the rotating speed is 100 revolutions / minute for secondary melt blending, and then pulled, cooled and cut to prepare uniform size particles.

[0052] 3) The prepared particles are placed in a blast drying oven, dried at 70 ℃ for 2h, and then transferred to an injection molding machine, the temperature of each temperature zone is set to 170, 190, 210, 230, 230 ℃, the mold temperature is 40 ℃, and the standard sample is obtained under the pressure of 60 bar for 40s.

[0053] Example 5

[0054] 1) According to the mass fraction, the random copolymer polypropylene 60 parts, linear low density polyethylene 40 parts, DCP initiator 0.05 parts are uniformly mixed in a high-speed mixer, added into a twin-screw extruder, the temperature of each temperature section is set to 160, 180, 195, 200, 200, 200, 200, 190, 160 ℃, and the rotating speed is 70 revolutions / minute for melt extrusion, and then cooled, pulled, and cut to prepare polyethylene grafted modified random copolymer polypropylene master batch.

[0055] 2) Take the above grafted modified random copolymer polypropylene master batch 20 parts, mix with impact polypropylene 80 parts, antioxidant 1010 0.5 parts, antioxidant 168 1 part uniformly, put into a twin-screw extruder, set the temperature of each temperature section to 180, 200, 220, 230, 230, 230, 230, 210, 180 ℃, and the rotating speed is 100 revolutions / minute for secondary melt blending, and then pulled, cooled and cut to prepare uniform size particles.

[0056] 3) The prepared granules were placed in a blast drying oven, dried at 70 °C for 2 h, and then transferred to an injection molding machine, with the temperature of each temperature zone set to 170, 190, 210, 230, 230 °C, the mold temperature set to 40 °C, and the pressure holding time set to 40 s under a pressure holding pressure of 60 bar, to obtain standard samples.

[0057] Comparative Example 1

[0058] 1) According to mass parts, 100 parts of impact polypropylene, 0.5 parts of antioxidant 1010, and 1 part of antioxidant 168 were uniformly mixed and placed in a twin-screw extruder, with the temperature of each temperature section set to 180, 200, 220, 230, 230, 230, 230, 210, 180 °C, and the rotation speed set to 100 revolutions / minute for melt blending, followed by traction cooling and granulation to obtain uniformly sized granules.

[0059] 2) The prepared granules were placed in a blast drying oven, dried at 70 °C for 2 h, and then transferred to an injection molding machine, with the temperature of each temperature zone set to 170, 190, 210, 230, 230 °C, the mold temperature set to 40 °C, and the pressure holding time set to 40 s under a pressure holding pressure of 60 bar, to obtain standard samples.

[0060] Comparative Example 2

[0061] 1) According to mass parts, 15 parts of random copolymer polypropylene, 85 parts of impact polypropylene, 0.5 parts of antioxidant 1010, and 1 part of antioxidant 168 were uniformly mixed and placed in a twin-screw extruder, with the temperature of each temperature section set to 180, 200, 220, 230, 230, 230, 230, 210, 180 °C, and the rotation speed set to 100 revolutions / minute for melt blending, followed by traction cooling and granulation to obtain uniformly sized granules.

[0062] 2) The prepared granules were placed in a blast drying oven, dried at 70 °C for 2 h, and then transferred to an injection molding machine, with the temperature of each temperature zone set to 170, 190, 210, 230, 230 °C, the mold temperature set to 40 °C, and the pressure holding time set to 40 s under a pressure holding pressure of 60 bar, to obtain standard samples.

[0063] Comparative Example 3

[0064] 1) According to mass parts, 9 parts of random copolymer polypropylene and 6 parts of linear low-density polyethylene were uniformly mixed with 85 parts of impact polypropylene, 0.5 parts of antioxidant 1010, and 1 part of antioxidant 168, and placed in a twin-screw extruder, with the temperature of each temperature section set to 180, 200, 220, 230, 230, 230, 230, 210, 180 °C, and the rotation speed set to 100 revolutions / minute for melt blending, followed by traction cooling and granulation to obtain uniformly sized granules.

[0065] 2) The prepared particles were placed in a blast drying oven, dried at 70 ℃ for 2 h, and then transferred to an injection molding machine, with the temperature of each temperature zone set at 170, 190, 210, 230, and 230 ℃, the mold temperature set at 40 ℃, and the pressure holding time set at 40 s under a pressure of 60 bar, to obtain standard samples.

[0066] Figure 1 The infrared spectrum of the graft-modified random copolymerized polypropylene masterbatch prepared in Examples 1-3 is shown in FIG. 1. Figure 1 As can be seen from FIG. 1, the ungrafted random copolymerized polypropylene has no obvious ethylene characteristic peak in the range of 777-679 cm -1 -1, and only a weak peak appears, while the graft products all exhibit a relatively obvious ethylene characteristic peak, indicating that polyethylene is successfully grafted onto the molecular chain of the random copolymerized polypropylene.

[0067] The samples prepared in Examples 1-5 and Comparative Examples 1-3 were subjected to performance testing, and the results are shown in Table 1.

[0068] Table 1

[0069]

[0070] As can be seen from Table 1, the modified random copolymerized polypropylene toughened impact polypropylene material prepared in the present application has a certain degree of improvement in rigidity and toughness, and Example 2 has the best rigidity-toughness balance.

[0071] The above description is merely preferred embodiments of the present application, and any changes and modifications made within the scope of the present application should be included in the scope of the present application.

Claims

1. A modified, random copolymer polypropylene toughened, impact polypropylene material characterized in that, The polyethylene grafting modified random copolymerized polypropylene master batch is uniformly mixed with a linear low density polyethylene and an initiator in a high speed mixer, and then is melt extruded in a double screw extruder, and is cooled, pulled, and cut to be prepared. The temperature of each temperature section of the double screw extruder is 160-200 DEG C, and the rotating speed is 60-100 r / min. The raw materials used are as follows in terms of mass parts: random copolymerized polypropylene 50-70 parts, linear low density polyethylene 30-50 parts, and initiator 0.05-0.1 part.

2. The modified, random copolymer polypropylene, impact toughened polypropylene material of claim 1, wherein, The ethylene content of the random copolymerized polypropylene is 3-7%, the melting point is 130-170 DEG C, and the melt index is 1-10 g / 10 min.

3. The modified, random copolymer polypropylene toughened, impact polypropylene material according to claim 1 or 2, characterized in that, The melt index of the linear low density polyethylene is 10-50 g / 10 min.

4. The modified, random copolymer polypropylene toughened, impact polypropylene material according to claim 1 or 2, characterized in that, The initiator is one of DHBP, BPO, and DCP.

5. The modified, random copolymer polypropylene, impact toughened polypropylene material of claim 1 or 2, wherein, The melt index of the impact polypropylene is 1-10 g / 10 min, the content of xylene soluble matter in the impact polypropylene is 20-30%, the content of xylene insoluble matter is 70-80%, and the ethylene content in the xylene insoluble matter is 1-4%.

6. The modified, random copolymer polypropylene, impact toughened polypropylene material of claim 1, wherein, The antioxidant is one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, and antioxidant 626.

7. The modified, random copolymer polypropylene, impact toughened polypropylene material of claim 1, wherein, The preparation steps are as follows:

8. The modified, random copolymer polypropylene, impact toughened polypropylene material of claim 1, wherein, (1) melt blending: uniformly mixing the polyethylene grafting modified random copolymerized polypropylene master batch, impact polypropylene, and antioxidant, and placing in a double screw extruder for melt blending, and then pulling, cooling, and cutting to prepare particles of uniform size; (2) sample drying: drying the particles obtained in step (1); (3) injection molding: using an injection molding machine to injection mold the particle sample obtained in step (2) into a standard sample. The temperature of each temperature section of the double screw extruder in step (1) is 180-230 DEG C, and the rotating speed is 60-100 r / min; 9. The modified, random copolymer polypropylene, impact toughened polypropylene material of claim 8, wherein, The drying temperature in step (2) is 60-100 DEG C, and the time is 1-3 h; The temperature of each temperature section of the injection molding machine in step (3) is 170-230 DEG C, the holding pressure is 30-80 bar, the holding time is 40 s, and the mold temperature is 40 DEG C. ​

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