High-flow high-impact transparent polypropylene material

Abstract

The invention relates to a polypropylene material, in particular to a high-flow high-impact transparent polypropylene material. The polypropylene material has excellent flowability, impact property and optical property, and the simply supported beam impact strength IS [kJ.m <-2 >], flexural modulus FM [MPa], xylene soluble substance content XS [%], ethylene content ECXS [%] in xylene soluble substances, intrinsic viscosity IVXS [dl.g <-1 >] and haze H [%] meet a certain relational expression. The high-flowability and high-impact-resistance transparent polypropylene product provided by the invention has excellent flowability, impact property and optical property, and can meet the requirements of the market on the toughness of the high-flowability transparent material.

Description

Technical Field

[0001] The invention relates to a polypropylene material, in particular to a high-flow and high-impact transparent polypropylene material. Background Art

[0002] Transparent polypropylene is one of the important varieties of polypropylene, and its application fields are wide, covering many fields from packaging materials to medical materials. With the improvement of the quality of life, the market requirements for transparent material products are gradually increasing. However, the toughness of traditional transparent polypropylene is poor, especially the toughness of high-flow transparent polypropylene is even worse. The high breakage rate of products during transportation, storage, and application is a pain point in the application of high-flow transparent polypropylene products. The potential demand is to improve the toughness of products. When downstream customers apply, they usually add toughening agents during the processing process, which not only adds a processing step and increases processing costs, but also makes the product performance unstable and the improvement effect is not obvious. In addition, the addition of toughening agents often reduces the transparency of the product, makes the product foggy, and makes the product soft.

[0003] Therefore, developing a high-flow and high-impact transparent polypropylene material meets the needs of market development and is also one of the current research hotspots of transparent materials. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a high-flow and high-impact transparent polypropylene material, which has excellent flowability, impact resistance and optical properties.

[0005] The high-flow and high-impact transparent polypropylene material of the present invention has a melt index of ≥50g / 10min, a xylene soluble content of 10-25wt%, and a xylene soluble intrinsic viscosity of 0.5-1.5dl·g -1 , the ethylene content in the xylene soluble matter is 20 to 30 wt%;

[0006] The simply supported beam impact strength and xylene soluble content of the high flow and high impact transparent polypropylene material satisfy the formula (1), and the flexural modulus and xylene soluble content satisfy the formula (2);

[0007] 0.73×e 0.0565XS ≤IS≤1.18×e 0.3236XS (1);

[0008] 975-27.5×XS≤FM≤1987.5-27.5×XS (2);

[0009] In formulas (1) to (2), XS is the xylene soluble content, unit: wt%; IS is the simply supported beam impact strength, unit: kJ·m -2 ; FM is the bending modulus, unit: MPa;

[0010] The haze and xylene soluble intrinsic viscosity of the high flow and high impact transparent polypropylene material satisfy formula (3), and the haze and ethylene content in xylene solubles satisfy formula (4);

[0011]

[0012] H≤2×10 -3 ×EC XS 2.71 (4);

[0013] In formula (3) to (4), H is the haze, unit: %; IV XS is the intrinsic viscosity of xylene soluble matter, unit: dl·g -1 ;EC XS It is the ethylene content in xylene solubles, unit: wt%.

[0014] The high-flow and high-impact transparent polypropylene material of the present invention has a xylene soluble matter content XS between 10 and 25 wt %, preferably between 12 and 22 wt %, and more preferably between 15 and 20 wt %.

[0015] The simply supported beam impact strength IS and the xylene soluble content XS of the high flow and high impact transparent polypropylene material of the present invention satisfy the relationship of formula (1):

[0016] 0.73×e 0.0565XS ≤IS≤1.18×e 0.3236XS (1).

[0017] The high-flow and high-impact transparent polypropylene material of the present invention has excellent impact resistance. When IS in formula (1) is greater than or equal to 0.73×e 0.1413XS When the relationship is not satisfied, that is, the simply supported beam impact strength is too small, the toughness of the product is insufficient, and it is easy to be damaged by external forces during storage, transportation, and application, and cannot meet the needs of application fields such as milk tea cups and yogurt cups; when IS≤1.18×e in formula (1) 0.1294XS When the relationship is not satisfied, that is, when the simply supported beam impact strength is high, the toughness of the product is better, but the overall product is soft and lacks rigidity.

[0018] The high-flow and high-impact transparent polypropylene material of the present invention preferably satisfies the following relationship: 0.73×e 0.1924XS ≤IS≤1.18×e 0.1294XS , more preferably: 0.73×e 0.2106XS ≤S≤1.18×e 0.1221XS .

[0019] The flexural modulus FM and the xylene soluble content XS of the high flow and high impact transparent polypropylene material of the present invention satisfy the relationship of formula (2):

[0020] 975-27.5×XS≤FM≤1987.5-27.5×XS (2).

[0021] The high-flow and high-impact transparent polypropylene material of the present invention has good rigidity. When the relationship of FM≥975-27.5×XS in formula (2) is not satisfied, that is, the bending modulus is low, the rigidity of the product is insufficient, the product is overall soft, and the product is easily deformed when subjected to external force; when the relationship of FM≤1987.5-27.5×XS in formula (2) is not satisfied, that is, the bending modulus is high, the processing difficulty will be greatly increased.

[0022] The high-flow and high-impact transparent polypropylene material of the present invention preferably satisfies the following relationship: 1075-27.5×XS≤FM≤1887.5-27.5×XS, and more preferably: 1175-27.5×XS≤FM≤1787.5-27.5×XS.

[0023] The intrinsic viscosity IV of the xylene solubles of the high flow and high impact transparent polypropylene material of the present invention XS Usually 0.5~1.5dl·g -1 , preferably 0.6 to 1.4 dl·g -1 .

[0024] The haze H of the high flow and high impact transparent polypropylene material of the present invention and the intrinsic viscosity IV of the xylene soluble matter XS Satisfying the relationship (3):

[0025]

[0026] The haze H of the high flow and high impact transparent polypropylene material of the present invention and the intrinsic viscosity IV of the xylene soluble matter XS Satisfying the relationship of formula (3), when When it is not satisfied, that is, when the haze is too high, the transparency of the product is reduced, affecting the visual effect and being unsightly.

[0027] The high-flow and high-impact transparent polypropylene material of the present invention preferably satisfies the following relationship:

[0028]

[0029] The ethylene content EC in the xylene soluble matter of the high flow and high impact transparent polypropylene material of the present invention is XS Between 20 and 30 wt%, preferably between 22 and 28 wt%.

[0030] The haze H of the high flow and high impact transparent polypropylene material of the present invention and the ethylene content EC in the xylene soluble matter XS Satisfying the relationship (4):

[0031] H≤2×10 -3 ×EC XS 2.71 (4).

[0032] The high-flowability and high-impact transparent polypropylene material of the present invention has excellent optical properties compared to conventional impact-resistant polypropylene. When the relationship of formula (4) is not satisfied, that is, when the haze is too high, the transparency requirement of the product cannot be met.

[0033] The high flow and high impact transparent polypropylene material of the present invention preferably satisfies the following relationship: H≤1.5×10 -3 ×EC XS 2.71 .

[0034] The monomers for preparing the high-flow and high-impact transparent polypropylene material of the present invention include propylene and ethylene.

[0035] The high flow and high impact transparent polypropylene material of the present invention is preferably prepared according to the following steps:

[0036] A) adding a main catalyst, a co-catalyst and an external electron donor into a catalyst pre-contact tank to perform an activation reaction of the main catalyst; subsequently, the activation reaction product enters a prepolymerization reactor for a prepolymerization reaction to generate a prepolymerization reaction product;

[0037] Preferably, the activation reaction is carried out at a temperature of 10-15° C. and a pressure of 40-45 bar.

[0038] Preferably, the prepolymerization reaction temperature is 15-30° C. and the pressure is 3.0-4.5 MPa.

[0039] Preferably, the main catalyst is a Ziegler-Natta catalyst.

[0040] Furthermore, the Ziegler-Natta catalyst is a porous granular or spherical catalyst containing a titanium compound with a magnesium halide as a carrier; the titanium compound is selected from any one of titanium tetrachloride, titanium tetrabromide, and titanium tetraiodide; the magnesium halide compound is selected from any one of magnesium dichloride, magnesium dibromide, and magnesium diiodide.

[0041] Preferably, the co-catalyst includes any one or more of triethylaluminum, triisobutylaluminum, dimethylaluminum monochloride, diethylaluminum monochloride, and monoisobutylaluminum dichloride.

[0042] Preferably, the external electron donor is a silane compound, including any one or more of cyclohexylmethyldimethoxysilane, cyclohexylmethyltrimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, diisopropyldimethoxysilane, and phenyltrimethoxysilane.

[0043] B) subjecting the prepolymerization product, hydrogen and polymerization monomer to polymerization reaction in a polymerization reactor to generate a first polymerization product;

[0044] Preferably, the polymerizable monomers mainly include propylene or propylene and ethylene.

[0045] Preferably, the polymerization reaction temperature is 60-75° C., the pressure is 3.0-4.5 MPa, and the hydrogen concentration is 1000-4000 ppm.

[0046] Preferably, the polymerization reactor comprises one or more of a tank reactor, a multi-zone circulation reactor, a loop reactor, a fluidized bed reactor, and a gas-phase stirred tank.

[0047] C) adding propylene, ethylene and hydrogen in proportion in the presence of the first polymer product, and copolymerizing and reacting in a copolymerization reactor to generate a high-flow, high-impact, transparent polypropylene powder;

[0048] Preferably, the copolymerization reactor includes a tank reactor, a fluidized bed reactor, or a gas phase stirred tank.

[0049] Preferably, the copolymerization reaction temperature is 65-90° C., the pressure is 1.0-2.0 MPa, wherein the molar ratio of ethylene / (ethylene+propylene) is 0.1-0.35, and the molar ratio of hydrogen / ethylene is 0.1-0.6.

[0050] D) The high-flowability and high-impact transparent polypropylene powder obtained in step C) is added with an antioxidant, an acid absorber, a transparent nucleating agent, and an antistatic agent, and then extruded and granulated to obtain a high-flowability and high-impact transparent polypropylene material.

[0051] Preferably, the antioxidant includes any one or more of 1010, 3114, 1076, 168, BHT, and 626; the amount of the antioxidant added is 300 to 3000 ppm; the acid absorber includes any one or more of calcium stearate, zinc stearate, and synthetic hydrotalcite; the amount of the acid absorber added is 100 to 1000 ppm; the transparent nucleating agent includes any one or a mixture of two or more of 3988 and NX8000; the amount of the transparent nucleating agent added is 1000 to 4000 ppm; the antistatic agent includes one or more of GMS40, GMS55, and GMS90; the amount of the antistatic agent added is 100 to 1000 ppm.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The present invention provides a high-flow and high-impact transparent polypropylene material, wherein the high-flow and high-impact transparent polypropylene material has a melt index of ≥50g / 10min, a xylene soluble content XS[%] between 10 and 25, and a simply supported beam impact strength IS[kJ·m -2 ], flexural modulus FM [MPa] and xylene soluble content satisfy formulas (1) and (2) respectively; having a xylene soluble intrinsic viscosity IV of 0.5 to 1.5 XS [dl g -1 ], ethylene content in xylene soluble matter of 20-30 EC XS [%], and the haze H [%] that satisfies the formulas (3) and (4).

[0054] After testing, it was found that the high-flow and high-impact transparent polypropylene material that meets the above relationship has excellent comprehensive properties, such as excellent impact resistance, excellent optical properties, good fluidity, high rigidity, and excellent processing performance. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Examples 1 to 5, Comparative Examples 1 to 2

[0057] The Spheripol polymerization process device is used to produce high-flow, high-impact transparent polypropylene materials; wherein the main catalyst is a Ziegler-Natta catalyst with a titanium loading of 2.95wt%; the co-catalyst is triethylaluminum with an aluminum-titanium molar ratio of 150; the external electron donor is C-Donor (cyclohexylmethyldimethoxysilane), and the mass ratio of the co-catalyst to the external electron donor is 3.

[0058] A) adding a main catalyst, a co-catalyst and an external electron donor into a catalyst pre-contact tank to perform a main catalyst activation reaction at a reaction temperature of 10 to 15° C. and a reaction pressure of 40 to 45 bar; then, the activation reaction product enters a prepolymerization reactor for a prepolymerization reaction at a reaction temperature of 20° C. and a reaction pressure of 3.8 MPa to generate a prepolymerization reaction product;

[0059] B) subjecting the prepolymerization product, hydrogen and a polymerizable monomer (propylene) to a polymerization reaction in a polymerization reactor to generate a first polymerized product; wherein the polymerization reactor used is composed of a first loop reactor and a second loop reactor arranged in series;

[0060] C) adding propylene, ethylene and hydrogen in proportion in the presence of the first polymer product, and copolymerizing and reacting in a copolymerization reactor to generate a high-flow, high-impact, transparent polypropylene powder;

[0061] D) To the high-flow, high-impact, transparent polypropylene powder obtained in step C), 500 ppm of antioxidant 1010, 1000 ppm of antioxidant 168, 500 ppm of calcium stearate, 300 ppm of antistatic agent GMS90, and 2000 ppm of transparent nucleating agent NX8000 are added; followed by extrusion granulation to obtain a high-flow, high-impact, transparent polypropylene material.

[0062] The specific reaction conditions and parameters are shown in Table 1.

[0063] Table 1 Reaction conditions and parameters of examples and comparative examples

[0064]

[0065] The specific product structure and performance indicators are shown in Table 2.

[0066] Table 2 Specific product structure and performance indicators

[0067] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 <![CDATA[Melt flow rate MFR [g·10min -1 > 55.5 60.8 62.4 53 65.1 Xylene soluble content XS [%] 16.8 19.3 21.6 22.5 27.8 <![CDATA[Izod impact strength IS [kJ·m -2 > 8.2 10.3 12.8 13.7 26.5 The left side of formula (1) 7.8 11.2 15.4 17.5 37.1 The right side of formula (1) 10.4 14.3 19.3 21.7 43.1 Flexural modulus FM[MPa] 1034.8 922.3 863.6 842.8 680.7 The left side of formula (2) 513 444.25 381 356.25 210.5 The right side of formula (2) 1525.5 1456.75 1393.5 1368.75 1223 <![CDATA[Intrinsic viscosity IV of xylene soluble matter XS [dl·g -1 > 0.99 0.95 1.03 2.3 0.98 The right side of formula (3) 7.9 7.4 8.5 84.8 7.8 Haze H[%] 10.5 9.8 12.6 33 40.6 <![CDATA[Ethylene content EC of xylene soluble matter XS [%]]]> 22.6 23.5 25.1 34.3 38.2 The right side of formula (4) 9.3 10.4 12.4 29.0 38.8

[0068] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-flow and high-impact transparent polypropylene material, characterized in that: The high-flow and high-impact transparent polypropylene material has a melt index of ≥50 g / 10 min, a xylene soluble content of 10-25 wt%, and a xylene soluble intrinsic viscosity of 0.5-1.5 dl·g -1 , the ethylene content in the xylene soluble matter is 20 to 30 wt%; The simply supported beam impact strength and xylene soluble content of the high flow and high impact transparent polypropylene material satisfy the formula (1), and the flexural modulus and xylene soluble content satisfy the formula (2); 0.73×e 0.0565XS ≤IS≤1.18×e 0.3236XS (1); 975-27.5×XS≤FM≤1987.5-27.5×XS (2); In formulas (1) to (2), XS is the xylene soluble content, unit: wt%; IS is the simply supported beam impact strength, unit: kJ·m -2 ; FM is the bending modulus, unit: MPa; The haze and xylene soluble intrinsic viscosity of the high flow and high impact transparent polypropylene material satisfy formula (3), and the haze and ethylene content in xylene solubles satisfy formula (4); H≤2×10 -3 ×EC XS 2.71 (4); In formulas (3) to (4), H is the haze, unit: %; IV XS is the intrinsic viscosity of xylene soluble matter, unit: dl·g -1 ; EC XS It is the ethylene content in xylene solubles, unit: wt%.

2. The high-flow and high-impact transparent polypropylene material according to claim 1, characterized in that: The monomers for preparing the high-flow and high-impact transparent polypropylene material include propylene and ethylene.

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