Formula and preparation method of compounding agent for beta crystal form polypropylene

Abstract

The invention relates to the technical field of polypropylene material production auxiliaries, in particular to a formula and a preparation method of a compound agent for beta-crystal polypropylene, the formula comprises a compound beta-crystal nucleating agent, a compound beta-crystal stabilizer and a compound antioxidant; the composite beta crystal nucleating agent comprises aryl dicarboxamide and calcium pimelate; the composite beta crystal stabilizer is prepared from beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylene bis-stearamide (EBS) WPP polypropylene wax. According to the invention, the first nucleating agent aryl dicarboxamide and the second nucleating agent calcium pimelate are matched for use, which is different from the existing scheme and method of independent use, so that the inductivity of the beta crystal is increased; and the beta-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate serving as a first stabilizer and the ethylene bis-stearamide (EBS) WPP polypropylene wax serving as a second stabilizer are matched for use, so that the beta crystal can be cured, and the produced polypropylene beta crystal is more stable.

Description

Technical Field

[0001] The invention relates to the technical field of polypropylene material production additives, and is a compounding agent formula for beta-crystalline polypropylene. It also includes a method for preparing beta-crystalline polypropylene material by using the compounding agent formula for beta-crystalline polypropylene, and the beta-crystalline polypropylene material obtained according to the method. Background Art

[0002] The high content of β-crystals and their stable presence in polypropylene resin can bring excellent mechanical and long-term performance to polypropylene resin, making the products made of this type of resin use less materials than ordinary polypropylene resin (without β-crystals), becoming a high-end polypropylene material recognized by users, and a green and low-carbon polymer polyolefin material. The key features of polypropylene β-crystal resin: the high content of polypropylene β-crystals is still maintained under the conditions of interference factors such as multiple melting and masterbatch addition, and it is stably present in the terminal products. At present, β-crystal polypropylene mainly relies on imports. The β-crystal PP-RCT and PP-H resin special materials produced by domestic petrochemical plants have low β-crystal content and instability, which makes them unable to be mass-produced and promoted. Summary of the invention

[0003] The present invention provides a compounding agent formula for beta-crystalline polypropylene and a preparation method thereof, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problem of low and unstable beta-crystalline content in beta-crystalline polypropylene materials.

[0004] One of the technical solutions of the present invention is achieved through the following measures: a compounding agent formula for β-crystalline polypropylene, which includes 0.05 to 1 part of a composite β-crystalline nucleating agent, 0.05 to 1 part of a composite β-crystalline stabilizer, and 0.01 to 0.5 part of a composite antioxidant in parts by weight; the composite β-crystalline nucleating agent includes aromatic diformamide and calcium pimelate; the composite β-crystalline stabilizer includes β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylene bis(b-butyl)amide (EBS) WPP polypropylene wax.

[0005] The molecular formula of calcium pimelate is C7H 10 CaO4; the molecular formula of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is C 18 H 28 O3.

[0006] The weight portion of the composite β-crystal stabilizer is preferably 0.1 to 0.2 parts.

[0007] This application uses a composite β-crystal stabilizer in combination with a composite β-crystal nucleating agent to make the β-crystals of polypropylene produced by induction not be disturbed by multiple factors and not transform into α-crystals during multiple melting processes. It can be applied to homopolymer, block, and random copolymer polypropylene resins containing β-crystals produced by different processes in petrochemical plants at home and abroad. Relevant verification has been completed in the 550,000-ton Innovene gas phase process polypropylene plant.

[0008] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: In the composite β-crystal nucleating agent, the weight percentage of the aromatic dicarbonamide is 10wt% to 90wt%, and the remainder is calcium pimelate.

[0009] In the composite β-crystal stabilizer, the weight percentage of the β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is 1wt% to 99wt%, and the balance is ethylene bis(b-butyl)amide (EBS) WPP polypropylene wax.

[0010] The carbon chain length of R in the above aromatic dicarboxamide is in the range of 8 to 12, and Ar is an alkaline earth metal, so that the first nucleating agent composed of aromatic dicarboxamide can play a role in increasing the induction rate of β crystals.

[0011] The length of the saturated alkane carbon chain in the ethylene bis(b-butylene)amide (EBS) WPP polypropylene wax is greater than 120.

[0012] The composite β-crystal nucleating agent is obtained by the following method: aromatic dicarbonamide is sequentially mixed with a first auxiliary solvent and a second auxiliary solvent for washing, the process is repeated three times, and the first nucleating agent is obtained after drying; calcium pimelate is sequentially mixed with the first auxiliary solvent and the second auxiliary solvent for washing, the process is repeated three times, and the second nucleating agent is obtained after drying; the required amount of the first nucleating agent and the second nucleating agent are mixed to obtain a composite β-crystal nucleating agent.

[0013] This application adopts the combination of a first nucleating agent composed of aromatic dicarboxamide and a second nucleating agent composed of calcium pimelate, as well as a method of reprocessing aromatic dicarboxamide and calcium pimelate, which is different from the existing schemes and treatment methods used alone, and increases the induction rate of β crystals. In addition, this application adopts a first stabilizer composed of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and a second stabilizer composed of ethylene bis-hard amide (EBS) WPP polypropylene wax, which can solidify β crystals and make the generated polypropylene β crystals more stable. The polypropylene composite β crystal nucleating agent and polypropylene β crystal stabilizer technology solves the bottleneck of the production of β crystal homopolymer, block, and random copolymer polypropylene resin special materials in domestic petrochemical plants, enables β crystal polypropylene materials to be applied on a large scale, broadens the application field of high-end resin special materials such as β crystal polypropylene, breaks the monopoly of foreign high-end polypropylene resin special materials, and enhances the competitiveness of domestic high-end polypropylene resin special materials, which has great social and economic benefits.

[0014] In the production of β-crystalline polypropylene materials, the present application uses the reprocessed first nucleating agent in combination with the second nucleating agent to increase the induction rate of β-crystals. Different from the current schemes and methods of using it alone, the commercially available β-crystal nucleating agent is reprocessed by washing it with an organic solvent multiple times to improve the purity of the commercial β-crystal nucleating agent, and can ensure that the β-crystals are not lost due to interference from processing conditions during processing. In addition, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylene bis(b-butyl)amide (EBS) WPP polypropylene wax are used as composite β-crystal stabilizers to solidify β-crystals, which is the first time. The composite β-crystal stabilizer produces a 1+1>2 effect through reprocessing and the use of the composite β-crystal nucleating agent, making the produced polypropylene β-crystals more stable. Polypropylene polymerization production equipment with different processes around the world can use the "compound formulation for β-crystalline polypropylene" of the present invention to produce homopolymer, block, and random β-crystalline polypropylene resins without adding additional equipment or changing the existing production process, and there is no impact of additive residue when switching to different brands.

[0015] The composite β-crystal stabilizer is obtained by the following method: a required amount of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is mixed with the ethylene bis(sterylamide) (EBS) WPP polypropylene wax, the mixture is heated to 100° C. to 200° C., the mixture is melted and then cooled in a room temperature environment, and ground into powder, the particle size of the powder ranges from 10 μm to 30 μm, to obtain a composite β-crystal stabilizer.

[0016] The above-mentioned step of sequentially mixing the aryl dicarbonamide with the first auxiliary solvent and the second auxiliary solvent for washing specifically comprises: Adding aryl dicarbonamide to the first auxiliary solvent and stirring for 0.4 to 0.6 hours, then distilling off the first auxiliary solvent, repeating this step N times to obtain a first solid; The first solid is added to the second auxiliary solvent and stirred for 0.4 to 0.6 hours, and then the second auxiliary solvent is evaporated, and this step is repeated M times, wherein N and M are positive integers.

[0017] The above-mentioned step of sequentially mixing calcium pimelate with the first auxiliary solvent and the second auxiliary solvent for washing specifically comprises: Adding calcium pimelate to the first auxiliary solvent and stirring for 0.4 to 0.6 hours, then distilling off the first auxiliary solvent, repeating this step P times to obtain a second solid; The second solid is added to the second auxiliary solvent and stirred for 0.4 h to 0.6 h, and then the second auxiliary solvent is evaporated, and this step is repeated Q times, wherein P and Q are positive integers.

[0018] The first auxiliary solvent is acetone, and the second auxiliary solvent is ethane oil.

[0019] For the homopolymer polypropylene, the compound antioxidant includes antioxidant 1010, antioxidant 168 and calcium stearate, and the mass ratio of antioxidant 1010, antioxidant 168 and calcium stearate is (1 to 2): (1 to 2): (0.2 to 0.5); or, for the impact copolymer polypropylene, the compound antioxidant includes antioxidant 1010, antioxidant 168, antioxidant 626 and distearic acid glycerol (DGMS), antioxidant 1010, antioxidant 168, antioxidant 626 and distearic acid glycerol (DGMS), The mass ratio of antioxidant 626 and distearic acid glycerol is (1 to 2): (1 to 2): (0.2 to 0.5): (0.2 to 0.5); or, for random copolymer polypropylene, the compound antioxidant includes antioxidant 1010, antioxidant 168, antioxidant 330 and calcium stearate, and the mass ratio of antioxidant 1010, antioxidant 168, antioxidant 330 and calcium stearate is (1 to 2): (1 to 2): (1 to 2): (0.2 to 0.5).

[0020] The Chinese name of antioxidant 1010 is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; The Chinese name of Antioxidant 330 is 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; The Chinese name of antioxidant 168 is tris(2,4-di-tert-butylphenyl) phosphite; The Chinese name of Cast is calcium stearate; The Chinese name of antioxidant 626 is bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite; The Chinese name of DGMS is distearate glycerol.

[0021] The second technical solution of the present invention is achieved by the following measures: a method for preparing a β-crystalline polypropylene material using the compounding agent formula for β-crystalline polypropylene described in one of the technical solutions, wherein the raw materials include 100 parts of polypropylene resin powder, 0.05 to 1 part of a composite β-crystalline nucleating agent, 0.05 to 1 part of a composite β-crystalline stabilizer, and 0.01 to 0.5 parts of a compounded antioxidant in parts by weight, and the required amount of polypropylene resin powder, the composite β-crystalline nucleating agent, the composite β-crystalline stabilizer and the compounded antioxidant are mixed in proportion, and the mixture is processed to obtain a β-crystalline polypropylene material.

[0022] The third technical solution of the present invention is achieved by the following measures: a β-crystalline polypropylene material is prepared by the method described in the second technical solution.

[0023] The present invention uses the reprocessed aromatic diformamide in combination with calcium pimelate for the first time, which is a domestic first creation. The reprocessed first nucleating agent aromatic diformamide and the second nucleating agent calcium pimelate are used in combination, which is different from the existing schemes and methods of using them separately, and the induction rate of β crystals is increased; and the present application uses the first stabilizer β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate in combination with the second stabilizer ethylene bis-hard amide (EBS) WPP polypropylene wax to solidify the β crystals and make the generated polypropylene β crystals more stable. The composite β crystal nucleating agent and composite β crystal stabilizer technology of the present invention solves the bottleneck of the production of β crystal homopolymer, block, and random copolymer polypropylene resin special materials in domestic petrochemical plants, enables the large-scale application of β crystal polypropylene materials, broadens the application field of high-end resin special materials such as β crystal polypropylene, breaks the monopoly position of foreign high-end polypropylene resin special materials, and enhances the competitiveness of domestic high-end polypropylene resin special materials, which has great social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The molecular formula of the aryl dicarbonamide provided in the embodiment of the present invention; Figure 2 The molecular formula of calcium pimelate provided in an embodiment of the present invention; Figure 3 The molecular formula of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate provided in the embodiment of the present invention; Figure 4 The molecular formula of ethylene bis(b-butylene)amide (EBS) WPP polypropylene wax provided in an embodiment of the present invention; Figure 5 A schematic diagram of the processing flow of the β-crystalline polypropylene material provided in an embodiment of the present invention; Figure 6A schematic diagram of the XRD analysis results of the β-crystal form of the β-crystal polypropylene material provided in Example 1 of the present invention after three melt extrusion; Figure 7 A schematic diagram of the DSC double melting point analysis results after three melt extrusions of the β-crystalline polypropylene material provided in Example 2 of the present invention; Figure 8 A schematic diagram of the DSC double melting point analysis results of the random copolymer polypropylene of the β-crystalline polypropylene material provided in Example 3 of the present invention; Fig. 9 A schematic diagram of XRD analysis results of the random copolymer polypropylene three times melt extruded β-crystal of the β-crystal polypropylene material provided in Example 3 of the present invention; Fig.10 This is a schematic diagram of the DSC double melting point analysis results of commercial random copolymer polypropylene; Fig.11 This is a schematic diagram of the XRD analysis results of the β-crystal of commercial random copolymer polypropylene after two melt extrusions; Fig.12 A schematic diagram of the test results of the normal temperature hydrostatic performance of a β-crystal PP-RCT pipe made of a β-crystal polypropylene material provided in Example 3 of the present invention; Fig.13 A schematic diagram of the high-temperature hydrostatic performance test results of a β-crystal PP-RCT pipe made of a β-crystal polypropylene material provided in Example 3 of the present invention; Fig.14 The present invention provides a schematic flow chart of a method for preparing a β-crystalline polypropylene material. DETAILED DESCRIPTION

[0025] The present invention is not limited by the following embodiments, and the specific implementation method can be determined according to the technical scheme of the present invention and the actual situation. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all chemical reagents and chemicals known and used in the prior art; unless otherwise specified, the percentages in the present invention are all mass percentages; unless otherwise specified, the solutions in the present invention are all aqueous solutions with water as the solvent, for example, hydrochloric acid solution is a hydrochloric acid aqueous solution; the normal temperature and room temperature in the present invention generally refer to a temperature of 15°C to 25°C, and are generally defined as 25°C.

[0026] The present invention will be further described below in conjunction with embodiments: In the present invention, the compounding agent formula for β-crystalline polypropylene includes, by weight, 0.05 to 1 part of a composite β-crystal nucleating agent, 0.05 to 1 part of a composite β-crystal stabilizer, and 0.01 to 0.5 part of a composite antioxidant; the composite β-crystal nucleating agent includes aromatic diformamide and calcium pimelate; the composite β-crystal stabilizer includes β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylene bis(b-butyl)amide (EBS) WPP polypropylene wax.

[0027] The chemical structure of aryl dicarbonamide is shown in Figure 1 ; The chemical structure of calcium pimelate is shown in Figure 2 ; The chemical structure of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is shown in Figure 3 ; The chemical structure of ethylene bis(b-butylene)amide (EBS) WPP polypropylene wax is shown in Figure 4 , Figure 4 The carbon chain in the formula shown is Cn, with n>120.

[0028] like Figure 5 As shown, the preparation method of the β-crystalline polypropylene material comprises: mixing 100 parts of polypropylene resin powder, 0.05 to 1 part of a composite β-crystalline nucleating agent, 0.05 to 1 part of a composite β-crystalline stabilizer and 0.01 to 0.5 parts of a compound antioxidant, and then granulating the uniformly mixed mixture through a twin-screw extruder at a temperature of 175° C. to 250° C. to obtain a granular β-crystalline polypropylene material.

[0029] like Fig.14 As shown, the method for preparing a β-crystalline polypropylene material using the compounding agent formula for β-crystalline polypropylene of the present invention comprises: S101: mixing aryl dicarbonamide with a first auxiliary solvent and a second auxiliary solvent in sequence to obtain a first nucleating agent; S103: mixing calcium pimelate with the first auxiliary solvent and the second auxiliary solvent in sequence to obtain a second nucleating agent; S105: mixing the first nucleating agent and the second nucleating agent in a weight percentage of 10wt% to 90wt% to obtain a composite β-crystal nucleating agent; mixing a composite β-crystal stabilizer, which is β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, with ethylene bis(b-butyl)amide (EBS) WPP polypropylene wax, to obtain a composite β-crystal stabilizer; S107: Mixing the polypropylene resin powder, the composite β-crystal nucleating agent, the composite β-crystal stabilizer and the compound antioxidant in proportion to obtain a second mixture, and processing the second mixture to obtain a β-crystal polypropylene material.

[0030] Example 1 The β-crystalline polypropylene material is prepared by the following method: 100 parts of homopolymer polypropylene resin powder, 0.05 parts of composite β-crystal nucleating agent, 0.07 parts of composite β-crystal stabilizer and 0.2 parts of compound antioxidant are mixed, and then the uniformly mixed mixture is granulated by a twin-screw extruder at a temperature of 175° C. to 250° C. to obtain a granular β-crystal polypropylene material.

[0031] In Example 1, the compound antioxidant includes antioxidant 1010, antioxidant 168 and calcium stearate, and the mass ratio of antioxidant 1010, antioxidant 168 and calcium stearate is 1:1:0.5. In the composite β-crystal nucleating agent, the mass percentages of aromatic diformamide and calcium pimelate are 50% respectively; in the composite β-crystal stabilizer, the mass percentages of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylene bis-stearamide (EBS) WPP polypropylene wax are 50% respectively.

[0032] The composite β-crystal nucleating agent is obtained by the following method: aryl dicarbonamide is sequentially mixed with acetone and ethane oil for washing, the process is repeated three times, and the first nucleating agent is obtained after drying; calcium pimelate is sequentially mixed with the acetone and ethane oil for washing, the process is repeated three times, and the second nucleating agent is obtained after drying; the required amount of the first nucleating agent and the second nucleating agent are mixed to obtain the composite β-crystal nucleating agent.

[0033] The step of sequentially mixing the aryl dicarbonamide with acetone and ethane oil for washing specifically comprises: Adding aryl dicarboxamide to the acetone, wherein the weight of the acetone is 5 times the weight of the aryl dicarboxamide, and stirring at room temperature for 0.5 h, then distilling off the acetone, and repeating this step twice to obtain a first solid; The first solid was added into the ethane oil, the weight of the ethane oil being 10 times the weight of the aromatic dicarbonamide, and stirred for 0.5 h, and then the ethane oil was evaporated, and this step was repeated twice.

[0034] The step of sequentially mixing calcium pimelate with acetone and ethane oil for washing specifically comprises: Calcium pimelate is added to the acetone, the weight of the acetone is 5 times the weight of the calcium pimelate, and stirred for 0.5h, then the acetone is evaporated, and this step is repeated twice to obtain a second solid; The second solid was added into the ethane oil, the weight of the ethane oil being 10 times the weight of the calcium pimelate, and stirred at 50° C. for 0.5 h, and then the ethane oil was evaporated, and this step was repeated twice.

[0035] The composite β-crystal stabilizer is obtained by the following method: a required amount of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is mixed with the ethylene bis(steryl)amide (EBS) WPP polypropylene wax, the mixing time is 1.5 minutes, the mixing speed is greater than 800r / min, the mixture is heated to 100°C to 200°C, the mixture is cooled in a room temperature environment after being melted, and ground into powder, the particle size of the powder ranges from 10μm to 30μm, and a composite β-crystal stabilizer is obtained.

[0036] The β-crystalline polypropylene material produced in Example 1 has a melt index of 3.2 g / 10 min, a tensile break nominal strain of 450%, and a simply supported beam impact strength of 35 kJ / m 2 , heat deformation temperature 88℃, XRD measured β-crystal content 78%, melt-crystallization analysis showed double melting points. The β-crystal polypropylene material was melt-extruded for the second time by a twin-screw extruder, and XRD (X-Ray Diffraction) measured the β-crystal content to be 74%; after adding the masterbatch for the third melt extrusion, XRD measured the β-crystal content to be 71%, and all basic physical properties remained good. The results of the β-crystal XRD analysis of the β-crystal polypropylene material after three melt extrusions are shown in Figure 6 .

[0037] Comparative Example 1 The commercial homopolymer polypropylene has a melt index of 3.1g / 10min, a β-crystal content of 72% as measured by XRD, and a double melting point as measured by melt-crystallization analysis. The commercial homopolymer polypropylene was melt-extruded for the second time by a twin-screw extruder, and the β-crystal content was 19% as measured by XRD; the color masterbatch was added and melt-extruded for the third time, and the β-crystal content was 12% as measured by XRD, the nominal strain at break was 470%, and the simply supported beam impact strength was 10kJ / m 2 , heat deformation temperature 75℃, and various basic physical properties decreased significantly.

[0038] Example 2 The β-crystalline polypropylene material is prepared by the following method: 100 parts of block copolymer polypropylene (i.e., impact copolymer polypropylene) resin powder, 0.1 parts of composite β-crystal nucleating agent, 0.05 parts of composite β-crystal stabilizer and 0.2 parts of compound antioxidant are mixed, and then the uniformly mixed mixture is granulated by a twin-screw extruder at a temperature of 175° C. to 250° C. to obtain a granular β-crystal polypropylene material.

[0039] The β-crystalline polypropylene material produced by the preparation method has a melt index of 0.35g / 10min, a tensile break nominal strain of 470%, and a simply supported beam impact strength of 160kJ / m 2 , heat deformation temperature 82℃, XRD measured β-crystal content 87%, melt-crystallization analysis showed double melting points of 162℃ / 152℃. The β-crystal polypropylene material was melt-extruded for the second time by a twin-screw extruder, and XRD measured β-crystal content of 75%; after adding masterbatch and melt-extruded for the third time, XRD measured β-crystal content of 76%, melt-crystallization analysis showed double melting points, α peak / β peak of 166℃ / 152℃, and all basic physical properties remained good. The DSC double melting point analysis results of the β-crystal polypropylene material after three melt extrusions are shown in Figure 7 .

[0040] In Example 2, the composite β-crystal nucleating agent and composite β-crystal stabilizer are the composite β-crystal nucleating agent and composite β-crystal stabilizer treated as described in Example 1. The compound antioxidant includes antioxidant 1010, antioxidant 168, antioxidant 626 and DGMS, and the mass ratio of antioxidant 1010, antioxidant 168, antioxidant 626 and DGMS is 1:2:0.5:0.3. In the composite β-crystal nucleating agent, the mass percentage of aromatic diformamide is 30%, and the mass percentage of calcium pimelate is 70%; in the composite β-crystal stabilizer, the mass percentage of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is 40%, and the mass percentage of ethylene bis-hard amide (EBS) WPP polypropylene wax is 60%.

[0041] Comparative Example 2 The commercially available block copolymer polypropylene has a melt index of 0.3g / 10min, a β-crystal content of 81% as measured by XRD, and a double melting point as measured by melt-crystallization analysis. The commercially available block polypropylene was melt-extruded for the second time by a twin-screw extruder, and the β-crystal content was 14% as measured by XRD; the color masterbatch was added and melt-extruded for the third time, and the β-crystal content was 8% as measured by XRD, the nominal strain at break was 490%, and the simply supported beam impact strength was 55kJ / m 2 , heat deformation temperature 70℃, double peak phenomenon in melting-crystallization analysis is not obvious, sometimes appears and sometimes does not, and various basic physical properties are obviously reduced.

[0042] Example 3 The β-crystalline polypropylene material is prepared by the following method: 100 parts of random copolymer polypropylene resin powder, 0.07 parts of composite β-crystal nucleating agent, 0.05 parts of composite β-crystal stabilizer and 0.1 parts of compound antioxidant are mixed, and then the uniformly mixed mixture is granulated by a twin-screw extruder at a temperature of 175° C. to 250° C. to obtain a granular β-crystal polypropylene material.

[0043] The β-crystalline polypropylene material produced by the preparation method has a melt index of 0.24g / 10min, a nominal strain at break of 415%, and a simply supported beam impact strength of 78kJ / m 2 , heat deformation temperature 76℃, XRD measured β-crystal content 86%, melt-crystallization analysis showed double melting points 149℃ / 136℃. The β-crystal polypropylene material was melt-extruded for the second time by a twin-screw extruder, and XRD measured β-crystal content 72%; the masterbatch was added and melted for the third time on the pipe extruder to prepare dn32 / S3.2 specification pipes. XRD measured β-crystal content 69% from the pipe sample, and all basic physical properties remained good. The random copolymer polypropylene DSC double melting point analysis results of β-crystal polypropylene material are shown in Figure 8 The XRD analysis results of random copolymer polypropylene three times melt extrusion β crystal are shown in Fig. 9 .

[0044] In Example 3, the composite β-crystal nucleating agent and composite β-crystal stabilizer are the composite β-crystal nucleating agent and composite β-crystal stabilizer treated as described in Example 1. The compound antioxidant includes antioxidant 1010, antioxidant 168, antioxidant 330 and calcium stearate, and the mass ratio of antioxidant 1010, antioxidant 168, antioxidant 330 and calcium stearate is 1:1:1:0.3. In the composite β-crystal nucleating agent, the mass percentage of aromatic diformamide is 80%, and the mass percentage of calcium pimelate is 20%; in the composite β-crystal stabilizer, the mass percentage of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is 10%, and the mass percentage of ethylene bis-hard amide (EBS) WPP polypropylene wax is 90%.

[0045] The gray dn32 / S3.2 specification β-crystalline PP-RCT pipe prepared by the preparation method in Example 3 passed the 20°C / 16MPa / 1h, 95°C / 4.2MPa / 22h, and 95°C / 4.0MPa / 165h hydrostatic performance tests. At room temperature, the pressure resistance grade and pressure resistance time were higher than the requirements of GB / T 18742.1-2017. The hydrostatic performance was excellent under high temperature and low ring stress. The hydrostatic performance test results of the β-crystalline PP-RCT pipe at room temperature (20°C) and high temperature (95°C) were shown in Table 1. Fig.12 and Fig.13 .

[0046] Comparative Example 3 The commercial random copolymer polypropylene has a melt index of 0.22g / 10min, a β-crystal content of 68% as measured by XRD, and a double melting point of 147℃ / 136℃ as measured by melt-crystallization analysis. The commercial random polypropylene was melt-extruded for the second time by a twin-screw extruder, and the β-crystal content was 31% as measured by XRD; the masterbatch was added and melted for the third time on a pipe extruder to prepare a dn32 / S3.2 specification pipe. The β-crystal content was 9% as measured by XRD from the pipe sample, the nominal strain at break from the tensile test from the pipe sample was 715%, and the simply supported beam impact strength was 25kJ / m 2 , heat deformation temperature 60℃, and various basic physical properties decreased significantly. The DSC double melting point analysis results of commercial random copolymer polypropylene are shown in Fig.10 The XRD analysis results of the commercial random copolymer polypropylene double melt extrusion β crystal are shown in Fig.11 .

[0047] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A compounding agent formula for β-crystalline polypropylene, characterized in that The invention comprises, by weight, 0.05 to 1 part of a composite β-crystal nucleating agent, 0.05 to 1 part of a composite β-crystal stabilizer, and 0.01 to 0.5 part of a composite antioxidant; the composite β-crystal nucleating agent comprises aromatic diformamide and calcium pimelate; the composite β-crystal stabilizer comprises β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylene bis(b-butyl)amide (EBS) WPP polypropylene wax.

2. The compounding agent formulation for β-crystalline polypropylene according to claim 1, characterized in that In the composite β-crystal nucleating agent, the weight percentage of the aromatic dicarboxamide is 10wt% to 90wt%, and the balance is calcium pimelate.

3. The compounding agent formulation for β-crystalline polypropylene according to claim 2, characterized in that The carbon chain length of R in the aryl dicarbonamide ranges from 8 to 12, and Ar is an alkaline earth metal.

4. The compounding agent formulation for β-crystalline polypropylene according to claim 1, 2 or 3, characterized in that In the composite β-crystal stabilizer, the weight percentage of the β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is 1wt% to 99wt%, and the balance is ethylene bis(b-butyl)amide (EBS) WPP polypropylene wax.

5. The compounding agent formulation for β-crystalline polypropylene according to claim 4, characterized in that The length of the saturated alkane carbon chain in the ethylene bis(b-butylene)amide (EBS) WPP polypropylene wax is greater than 120.

6. The compounding agent formulation for β-crystalline polypropylene according to any one of claims 1 to 5, characterized in that The composite β-crystal nucleating agent is obtained by the following method: aromatic dicarbonamide is sequentially mixed with a first auxiliary solvent and a second auxiliary solvent for washing, the washing is repeated three times, and the first nucleating agent is obtained after drying; calcium pimelate is sequentially mixed with the first auxiliary solvent and the second auxiliary solvent for washing, the washing is repeated three times, and the second nucleating agent is obtained after drying; the required amount of the first nucleating agent is mixed with the second nucleating agent to obtain a composite β-crystal nucleating agent; or / and, the composite β-crystal stabilizer is obtained by the following method: a required amount of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate is mixed with the ethylene bis(steryl)amide (EBS) WPP polypropylene wax, the mixture is heated to 100° C. to 200° C., the mixture is melted, cooled in a room temperature environment, and ground into powder, the particle size of the powder ranges from 10 μm to 30 μm, and a composite β-crystal stabilizer is obtained.

7. The compounding agent formulation for β-crystalline polypropylene according to claim 6, characterized in that The step of sequentially mixing the aryl dicarbonamide with the first auxiliary solvent and the second auxiliary solvent for washing specifically comprises: Adding aryl dicarbonamide to the first auxiliary solvent and stirring for 0.4 to 0.6 hours, then distilling off the first auxiliary solvent, repeating this step N times to obtain a first solid; The first solid is added to the second auxiliary solvent and stirred for 0.4 to 0.6 hours, and then the second auxiliary solvent is evaporated, and this step is repeated M times, wherein N and M are positive integers.

8. The compounding agent formulation for β-crystalline polypropylene according to claim 6 or 7, characterized in that The step of sequentially mixing calcium pimelate with a first auxiliary solvent and a second auxiliary solvent for washing specifically comprises: Adding calcium pimelate to the first auxiliary solvent and stirring for 0.4 to 0.6 hours, then distilling off the first auxiliary solvent, repeating this step P times to obtain a second solid; The second solid is added to the second auxiliary solvent and stirred for 0.4 h to 0.6 h, and then the second auxiliary solvent is evaporated, and this step is repeated Q times, wherein P and Q are positive integers.

9. The compounding agent formulation for β-crystalline polypropylene according to claim 6, 7 or 8, characterized in that The first auxiliary solvent is acetone, and the second auxiliary solvent is ethane oil.

10. The compounding agent formulation for β-crystalline polypropylene according to any one of claims 1 to 9, characterized in that For homopolymer polypropylene, the compound antioxidant includes antioxidant 1010, antioxidant 168 and calcium stearate, and the mass ratio of antioxidant 1010, antioxidant 168 and calcium stearate is (1 to 2): (1 to 2): (0.2 to 0.5); or, for impact copolymer polypropylene, the compound antioxidant includes antioxidant 1010, antioxidant 168, antioxidant 626 and distearic acid glyceride, and the mass ratio of antioxidant 1010, antioxidant 168, antioxidant 626 is (1 to 2): (1 to 2): (0.2 to 0.5). The mass ratio of antioxidant 1010, antioxidant 168, antioxidant 330 and calcium stearate is (1 to 2): (1 to 2): (0.2 to 0.5): (0.2 to 0.5); or, for random copolymer polypropylene, the compound antioxidant includes antioxidant 1010, antioxidant 168, antioxidant 330 and calcium stearate, and the mass ratio of antioxidant 1010, antioxidant 168, antioxidant 330 and calcium stearate is (1 to 2): (1 to 2): (1 to 2): (0.2 to 0.5).

11. A method for preparing a β-crystalline polypropylene material using the compounding agent formula for β-crystalline polypropylene according to any one of claims 1 to 10, characterized in that The raw materials include 100 parts of polypropylene resin powder, 0.05 to 1 part of composite β-crystal nucleating agent, 0.05 to 1 part of composite β-crystal stabilizer, and 0.01 to 0.5 part of compound antioxidant in parts by weight. The required amount of polypropylene resin powder, the composite β-crystal nucleating agent, the composite β-crystal stabilizer and the compound antioxidant are mixed according to proportion, and the mixture is processed to obtain β-crystal polypropylene material.

12. A β-crystalline polypropylene material prepared according to the method of claim 11.

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