Polypropylene material for anti-corrosion pipeline as well as preparation method and application of polypropylene material

Abstract

The invention relates to the technical field of high polymer materials, in particular to a polypropylene material for an anti-corrosion pipeline as well as a preparation method and application of the polypropylene material. The polypropylene material for the anti-corrosion pipeline is prepared from the following components in parts by weight: 50 to 80 parts of polypropylene matrix resin, 5 to 20 parts of polypropylene graft, 5 to 15 parts of flexibilizer, 5 to 15 parts of nylon elastomer, 1 to 3 parts of anti-ultraviolet filler, 5 to 15 parts of polyethylene and 0.3 to 1 part of antioxidant, in the polypropylene graft, the grafting rate is 2%-4.5%. The polypropylene material has the double characteristics of the outer-layer polypropylene and the adhesive, is not restricted by the adhesive in the production process of the anti-corrosion pipeline, simplifies the production process and equipment, not only improves the stability of the product performance, but also reduces the site and energy consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, in particular to a polypropylene material for anti-corrosion pipeline and a preparation method and application thereof. BACKGROUND

[0002] The pipeline three-layer polypropylene anti-corrosion layer (3PP) is composed of a fusion epoxy powder bottom layer, an adhesive intermediate layer and an outer polypropylene anti-corrosion layer. The fusion epoxy powder at the bottom layer is firmly adhered to the surface of the metal base through the formation of ionic bonds and physical intercalation force by the action of active groups and activated ions on the surface of the steel pipe. The adhesive intermediate layer combines the fusion epoxy powder bottom layer and the outer polypropylene layer organically, protects the bottom layer from external erosion, and makes the three layers organically combined into a whole, so that the anti-corrosion layer has the advantages of both fusion epoxy powder coating and polypropylene coating. With the surge in demand in the energy market, the production efficiency of anti-corrosion pipelines is also increasingly required. The conventional 3PP anti-corrosion production process has problems such as complex process, high energy consumption and poor stability, which affects the safe operation of the pipeline.

[0003] The polypropylene material currently used for 3PP anti-corrosion can meet the performance of the outer polypropylene, but has no adhesion to the epoxy powder, and needs to be used with an adhesive. Although the adhesion of the current adhesive can meet the requirements, the melt flow rate is high, the tensile strength is low, the environmental stress cracking resistance is poor, the aging resistance is low, and it cannot be used as an outer material. That is, the adhesive intermediate layer and the outer polypropylene anti-corrosion layer must be used simultaneously in the existing anti-corrosion layer, and the production process is complicated and the product performance stability is poor.

[0004] Chinese patent application No. CN104151947A discloses a polypropylene material for the outer anti-corrosion of buried pipeline, wherein the adhesive layer is omitted to simplify the process. However, the polypropylene material contains an antioxidant, a curing agent and a curing accelerator. The simultaneous use of these materials causes a high degree of uncertainty in the processing process, making the processing process difficult to control and affecting the stability of the material performance. Moreover, the simultaneous use of tetrabromobisphenol A and nano zinc oxide modified by silane coupling agent causes mutual conflict, which affects the performance of the material. Therefore, it is of great significance and challenge in the field to provide a polypropylene material that has the dual characteristics of adhesive and outer polypropylene, has certain mechanical strength, environmental stress cracking resistance and aging resistance while ensuring the adhesion to the epoxy powder.

[0005] In view of the above, the present application is proposed. SUMMARY

[0006] The polypropylene material for anti-corrosion pipeline, its preparation method and application have the double characteristics of the outer layer polypropylene and the adhesive, have good adhesion to the epoxy powder, have good mechanical properties, environmental stress cracking resistance and aging resistance, can simplify the anti-corrosion production process, and can significantly improve the stability of the performance of the anti-corrosion pipeline.

[0007] In order to achieve the above-mentioned purpose of the present application, the first aspect of the present application provides a polypropylene material for anti-corrosion pipeline, comprising the following components by weight fraction: polypropylene base resin 50-80 parts, polypropylene grafting material 5-20 parts, toughening agent 5-15 parts, nylon elastomer 5-15 parts, ultraviolet resistant filler 1-3 parts, polyethylene 5-15 parts and antioxidant 0.3-1 part; The grafting rate of the polypropylene grafting material is 2%-4.5%.

[0008] In the specific embodiment of the present application, the number average molecular weight of the polypropylene grafting material is 10000-80000, and the molecular weight distribution width is 1.5-3.

[0009] In the specific embodiment of the present application, the grafting monomer in the polypropylene grafting material includes glycidyl methacrylate and / or maleic anhydride.

[0010] In the specific embodiment of the present application, the polypropylene grafting material is mainly prepared by grafting reaction of polypropylene resin, grafting monomer and initiator in a solvent.

[0011] In the preparation of the polypropylene grafting material, the amount of the grafting monomer is 2wt%-5wt% of the polypropylene resin; and the amount of the initiator is 0.1wt%-0.5wt% of the polypropylene resin.

[0012] In the specific embodiment of the present application, the melt flow rate of the polypropylene resin at 230℃, 2.16kg is 5-25g / 10min.

[0013] In the specific embodiment of the present application, the Shore D hardness of the nylon elastomer is 40-75, the Vicat softening point is 130-170℃, and the melting point is 150-180℃.

[0014] In the specific embodiment of the present application, the polyethylene includes at least one of LDPE and LLDPE. Further, the melt flow rate of the polyethylene at 190℃, 2.16kg is 1-10g / 10min.

[0015] In the detailed description of the present application, the polypropylene matrix resin comprises at least one of homopolymer polypropylene, random copolymer polypropylene and block copolymer polypropylene. Further, the polypropylene matrix resin has a melt flow rate of 0.01-1 g / 10 min at 230℃ under the condition of 2.16 kg.

[0016] In the detailed description of the present application, the toughening agent comprises at least one of EPDM, POE, POP, propylene-based elastomer and SEBS. Further, the toughening agent has a melt flow rate of 0.1-5 g / 10 min at 190℃ under the condition of 2.16 kg.

[0017] In the detailed description of the present application, the anti-ultraviolet filler comprises titanium dioxide and / or carbon black.

[0018] The second aspect of the present application provides a preparation method of the polypropylene material for anticorrosive pipeline according to the first aspect of the present application, comprising the following steps: according to the composition of the polypropylene material for anticorrosive pipeline according to the first aspect of the present application, mixing and extruding granulation.

[0019] The third aspect of the present application provides an application of the polypropylene material for anticorrosive pipeline according to the first aspect in preparing anticorrosive pipeline.

[0020] Compared with the prior art, the present application has the following beneficial effects: (1) The polypropylene material of the present application has good adhesion to epoxy powder, and the peel strength at 20℃ can reach more than 350 N / cm, and the peel strength at 110℃ reaches 80 N / cm, meeting the strict requirements of ISO 21809-1 and SY / T 7041; (2) The polypropylene material of the present application has a tensile strength greater than 30 MPa, a yield strength greater than 20 MPa, a breaking nominal strain greater than 600%, and a micro-calc softening point greater than 140℃, which can meet the strict requirements of ISO 21809-1 and national standard SY / T 7041; (3) The polypropylene material of the present application has the dual characteristics of outer layer polypropylene and adhesive, and is not restricted by the adhesive in the production process of anticorrosive pipeline, simplifying the production process and equipment, not only improving the stability of product performance, but also reducing the consumption of site and energy. DETAILED DESCRIPTION

[0021] The technical solutions of the present application will be clearly and completely described below in conjunction with specific embodiments, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the present application, not all the embodiments, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the present application. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased on the market.

[0022] Since the adhesive layer and the outer layer of polypropylene in the 3PP anticorrosion need to have different properties, and the existing single-layer adhesive and single-layer polypropylene do not have the above-mentioned properties at the same time, the existing anticorrosion layer must use the adhesive intermediate layer and the outer layer of polypropylene anticorrosion layer at the same time. Such a structure not only increases the complexity of the production process and high energy consumption, but also leads to poor stability of the product. The present application research found that if a single-layer polypropylene material is used, in order to improve the adhesion performance of polypropylene to the bottom layer of the fused epoxy powder, simply introducing a polar monomer into the polypropylene material cannot be achieved. This is because, as an outer layer, in order to ensure its mechanical properties and environmental stress cracking resistance, aging resistance and other properties, the polypropylene material needs to have a very high cohesive strength. Under this cohesive strength, even if a polar monomer is introduced, it is also difficult to achieve adhesion to the epoxy powder. Therefore, the composition of the polypropylene material needs to be adjusted and designed to achieve adhesion to the epoxy powder on the basis of ensuring its basic properties as an outer layer.

[0023] Based on this, the present application provides a polypropylene material for anticorrosion pipes, comprising the following components in parts by weight: 50-80 parts of polypropylene base resin, 5-20 parts of polypropylene grafting material, 5-15 parts of toughening agent, 5-15 parts of nylon elastomer, 1-3 parts of anti-ultraviolet filler, 5-15 parts of polyethylene, and 0.3-1 parts of antioxidant; the grafting rate of the polypropylene grafting material is 2%-4.5%.

[0024] In the polypropylene material of the present application, the polypropylene base resin is introduced with polypropylene grafting material, nylon elastomer, and polyethylene, and various components work together to improve the adhesion performance of the polypropylene material to the epoxy powder, and at the same time improve the hardness, strength, and temperature resistance of the polypropylene material.

[0025] As in different embodiments, the amount of each component in the polypropylene material can be as follows in parts by weight: The amount of polypropylene base resin can be 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, or a range formed by any two of them; The amount of the polypropylene grafting agent can be 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, or a range consisting of any two of them; The amount of the toughening agent can be 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, or a range consisting of any two of them; The amount of the nylon elastomer can be 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, or a range consisting of any two of them; the appropriate amount of the nylon elastomer introduced in the present application can assist the polypropylene grafting agent in improving the adhesion to the epoxy powder, and on the other hand, improve the hardness and environmental stress cracking resistance of the polypropylene; The amount of the anti-ultraviolet filler can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, or a range consisting of any two of them; The amount of the polyethylene can be 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, or a range consisting of any two of them; the appropriate amount of the polyethylene introduced in the present application can adjust the cohesive energy of the polypropylene material and improve the adhesion of the polypropylene material to the epoxy powder; The amount of the antioxidant can be 0.3 parts, 0.5 parts, 0.8 parts, 1 part, or a range consisting of any two of them.

[0026] The polypropylene grafting agent with a grafting rate of 2% to 4.5% is used in the present application, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or a range consisting of any two of them, which helps to improve the reactivity in the system of the present application, and in the case of less addition amount, it can significantly improve the reaction speed of the polar group grafted therein and the epoxy, improve the adhesion to the epoxy powder, and avoid the brittleness of the material caused by the introduction of too much polypropylene grafting agent, and the impact on the impact performance and environmental stress cracking resistance.

[0027] In the specific embodiments of the present application, the number average molecular weight of the polypropylene grafting agent is 10000 to 80000, and the molecular weight distribution width is 1.5 to 3. The polypropylene grafting agent of the present application has a small molecular weight and a narrow molecular weight distribution, which helps to further improve the reactivity of the polypropylene grafting agent and further improve the adhesion to the epoxy powder. As in different embodiments, the number average molecular weight of the polypropylene grafting agent can be 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, or a range consisting of any two of them; the molecular weight distribution width can be 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3, or a range consisting of any two of them.

[0028] In the specific embodiments of the present application, the grafting monomer in the polypropylene grafting agent includes glycidyl methacrylate and / or maleic anhydride.

[0029] In the specific embodiments of the present application, the polypropylene grafting material is prepared by grafting reaction of polypropylene resin, grafting monomer and initiator in a solvent. Further, the temperature of the grafting reaction is 130-160℃, for example, it can be 130℃, 140℃, 150℃, 160℃ or a range consisting of any two of them; the time of the grafting reaction is 4-6h, for example, it can be 4h, 4.5h, 5h, 5.5h, 6h or a range consisting of any two of them.

[0030] The inventors of the present application found that the polypropylene grafting material prepared by the conventional melt grafting method not only has low grafting rate, but also has uneven distribution of grafting groups and uneven distribution of molecular weight. Moreover, the polypropylene grafting material prepared by the melt grafting method has high residual grafting monomer, such as maleic anhydride, and high copolymerization by-product of grafting monomer, which will both reduce the activity of the polypropylene grafting material. The melt flow rate of the polypropylene base resin used in the polypropylene material is very low, and the reaction activity of the polypropylene grafting material prepared by the melt grafting method in this system is weak, which leads to low reaction speed with epoxy and poor adhesion to epoxy powder. The polypropylene grafting material prepared by the solution grafting method has high grafting rate and uniform grafting distribution, and narrow molecular weight distribution width, compared with the polypropylene grafting material prepared by the conventional melt grafting method. The reaction activity of the corresponding polypropylene grafting material is significantly higher than that of the polypropylene grafting material prepared by the melt grafting method, which helps to improve the reaction speed of the polypropylene material with epoxy and significantly improve the adhesion to epoxy powder. At the same time, the addition of the remaining components ensures the cohesive energy of the polypropylene material.

[0031] In the specific embodiments of the present application, the mass ratio of the polypropylene grafting material to the nylon elastomer is (1.3-2):1, for example, it can be 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1 or a range consisting of any two of them, which helps to fully exert the compounding effect of the polypropylene grafting material and the nylon elastomer, so as to improve the adhesion strength and the mechanical properties of the polypropylene material.

[0032] In the specific embodiments of the present application, the polypropylene resin includes at least one of homopolymer polypropylene, random copolymer polypropylene and block copolymer polypropylene; the initiator includes organic peroxide initiator; and the solvent includes toluene and / or xylene. Further, the melt flow rate of the polypropylene resin at 230℃ and under the condition of 2.16kg is 2-30g / 10min, such as 2g / 10min, 5g / 10min, 8g / 10min, 10g / 10min, 12g / 10min, 15g / 10min, 20g / 10min, 22g / 10min, 25g / 10min, 30g / 10min or a range consisting of any two of them.

[0033] Among the organic peroxide initiators, there are at least one of dicumyl peroxide, 1,3-1,4 di-tert-butyl peroxide isopropyl benzene, 1,1-di-tert-butyl peroxide 3,3,5-cyclohexane, 4,4-di-tert-butyl peroxide n-butyl pentanoate, di-tert-butyl peroxide, tert-butyl cumyl peroxide, tert-butyl benzoic acid and 2,5-dimethyl-2,5 di-tert-butyl peroxide.

[0034] In the specific embodiment of the present application, the amount of grafting monomer used in the preparation of the polypropylene grafting product is 2wt% to 5wt% of the polypropylene resin; and the amount of initiator used is 0.1wt% to 0.5wt% of the polypropylene resin.

[0035] In actual operation, the preparation of the polypropylene grafting product can include: dissolving the polypropylene resin in a solvent, the dissolving temperature can be 130 to 160°C, after complete dissolution, slowly adding the initiator and the grafting monomer, and then reacting at 130 to 160°C for 4 to 6 hours; after the reaction is completed, washing with acetone or butanone to precipitate the product, and then performing suction filtration and drying to obtain the polypropylene grafting product. The initiator and the grafting monomer can be added at one time or in batches, for example, in two or three times.

[0036] In the specific embodiment of the present application, the Shore D hardness of the nylon elastomer is 40 to 75, for example, it can be 40, 50, 55, 60, 65, 70, 75 or a range formed by any two of them; the Vicat softening point is 130 to 170°C, for example, it can be 130°C, 140°C, 150°C, 160°C, 170°C or a range formed by any two of them; and the melting point is 150 to 180°C, for example, it can be 150°C, 160°C, 170°C, 180°C or a range formed by any two of them.

[0037] In the specific embodiment of the present application, the nylon elastomer includes at least one of PEBAX 4033SA, PEBAX 5533SA, PEBAX 6333SA and PEBAX 7233 produced by Arkema. By using the above-mentioned nylon elastomer, the molecular structure helps to further improve the comprehensive performance of the polypropylene material, especially the environmental stress cracking resistance of the polypropylene material, and at the same time, it assists the polypropylene grafting product to improve the reaction speed of the active group, thereby improving the bonding performance to the epoxy powder.

[0038] In the detailed description of the present application, the polyethylene includes at least one of LDPE and LLDPE. Further, the melt flow rate of the polyethylene under the condition of 190℃, 2.16kg is 1-10g / 10min, for example, it can be 1g / 10min, 3g / 10min, 5g / 10min, 8g / 10min, 10g / 10min or a range consisting of any two of them, thereby more helping to effectively adjust the cohesive energy of the polypropylene material, further improving the bonding performance of the polypropylene material with the epoxy powder.

[0039] In the detailed description of the present application, the polypropylene base resin includes at least one of homopolymer polypropylene, random copolymer polypropylene and block copolymer polypropylene. Further, the melt flow rate of the polypropylene base resin under the condition of 230℃, 2.16kg is 0.1-2.0g / 10min, for example, it can be 0.1g / 10min, 0.3g / 10min, 0.5g / 10min, 0.8g / 10min, 1g / 10min, 1.2g / 10min, 1.5g / 10min, 1.8g / 10min, 2g / 10min or a range consisting of any two of them. At least one of the homopolymer polypropylene, the random copolymer polypropylene and the block copolymer polypropylene with the melt flow rate meeting the above range is used as the base material to meet the basic requirements of the mechanical properties of the polypropylene material as the outer layer material.

[0040] In the detailed description of the present application, the toughening agent includes at least one of EPDM, POE, POP, propylene-based elastomer and SEBS. Further, the melt flow rate of the toughening agent under the condition of 190℃, 2.16kg is 0.1-5g / 10min, for example, it can be 0.1g / 10min, 0.5g / 10min, 1g / 10min, 2g / 10min, 3g / 10min, 4g / 10min, 5g / 10min or a range consisting of any two of them. The addition of the above-mentioned substances can further improve the uniformity of the mixing of the components in the polypropylene material, and improve the processing performance, the mechanical properties, the impact performance, the compression resistance and the environmental stress cracking resistance of the polypropylene material to better protect the bottom layer.

[0041] In the detailed description of the present application, the toughening agent includes EPDM and propylene-based elastomer. Further, the mass ratio of the EPDM and the propylene-based elastomer is 1:(0.8-1.2).

[0042] In the specific embodiment of the present application, the anti-ultraviolet filler includes titanium dioxide and / or carbon black. Further, the anti-ultraviolet filler is surface-treated titanium dioxide and / or silane coupling agent-treated carbon black, and the particle size of the carbon black is ≤30 nm. The titanium dioxide includes rutile titanium dioxide. The introduction of the appropriate amount of anti-ultraviolet filler can resist ultraviolet rays, reduce the damage of sunlight to the pipeline, and prolong the service life of the corrosion-resistant pipeline.

[0043] In the specific embodiment of the present application, the antioxidant includes but is not limited to at least one of antioxidant 1010, antioxidant 168, and antioxidant B245, and further includes ultraviolet absorption agent, light stabilizer, etc. The addition of the antioxidant can reduce the degradation of the polypropylene material during the processing, improve the oxidation induction period of the material, improve the thermal aging and light aging performance of the material, and effectively prolong the service life of the corrosion-resistant pipeline.

[0044] The second aspect of the present application provides a preparation method of the polypropylene material for the corrosion-resistant pipeline of the first aspect of the present application, including the following steps: mixing and extruding granulation according to the composition of the polypropylene material for the corrosion-resistant pipeline of the first aspect of the present application.

[0045] In the specific embodiment of the present application, the temperature in the extrusion granulation is 200-240℃. The extrusion granulation is performed by using a double-screw extruder according to the conventional extrusion granulation parameters.

[0046] The third aspect of the present application provides the application of the polypropylene material for the corrosion-resistant pipeline of the first aspect in the preparation of the corrosion-resistant pipeline.

[0047] Example 1 The present embodiment provides a polypropylene material for a corrosion-resistant pipeline, which includes the following components in parts by weight: 67.9 parts of polypropylene matrix resin, 5 parts of polypropylene grafting, 5 parts of toughening agent, 10 parts of nylon elastomer, 1.5 parts of anti-ultraviolet filler, 10 parts of polyethylene, and 0.6 parts of antioxidant.

[0048] The polypropylene matrix resin is random copolymerized polypropylene, and the melt flow index at 230℃ / 2.16kg is 0.4g / 10min. The toughening agent is EPDM and propylene-based elastomer, and the mass ratio of the two is 1:1. The melt flow indexes at 190℃ / 2.16kg are 0.4g / 10min and 1.5g / 10min, respectively. The nylon elastomer is PEBAX 5533SA of Arkema; The anti-ultraviolet filler is rutile titanium dioxide (DuPont R902); The polyethylene is LLDPE, and the melt flow index at 190℃ / 2.16kg is 4.5g / 10min. Antioxidants include antioxidant B215 0.4 parts, UV944 0.1 parts and antioxidant PS627 0.1 parts; The polypropylene graft is mainly prepared by solution grafting method from homopolymer polypropylene (melt flow index of 230℃ / 2.16kg is 20g / 10min), maleic anhydride and 1,1-di-tert-butyl peroxide 3,3,5-cyclohexane at a mass ratio of 100:3.5:0.2; specifically, the homopolymer polypropylene is dissolved in xylene (the mass of xylene is 10 times the mass of the homopolymer polypropylene), the dissolution temperature is 130-140℃, after complete dissolution, the initiator and maleic anhydride are slowly added, the temperature is raised to 150℃, and the reaction is carried out for 4h, then acetone is used for cleaning, the product is precipitated, then it is suction filtered and dried, to obtain the polypropylene graft, the maleic anhydride grafting rate is 3.2%, the molecular weight distribution width is 2, and the number average molecular weight is 30,000.

[0049] The embodiment provides a preparation method of the polypropylene material for corrosion-resistant pipelines, which comprises the following steps: weighing each component according to the above-mentioned proportions, uniformly mixing the components by a high-speed mixer, and then performing extrusion granulation by a double-screw extruder to obtain polypropylene particles. In the embodiment, the parameter settings of the double-screw extruder include: 160℃ for the first zone, 200℃ for the second zone, 220℃ for the third zone, 220℃ for the fourth zone, 220℃ for the fifth zone, 230℃ for the sixth zone, 230℃ for the seventh zone, 230℃ for the eighth zone, 220℃ for the die, 300RPM for the main machine speed, and 10HZ for the feeding.

[0050] Example 2 The embodiment refers to the polypropylene material for corrosion-resistant pipelines and the preparation method thereof in the embodiment 1, and the only difference is that the dosages of the components are different.

[0051] The polypropylene material for corrosion-resistant pipelines in the embodiment comprises the following components in parts by weight: 52.9 parts of polypropylene matrix resin, 20 parts of polypropylene graft, 5 parts of toughening agent, 10 parts of nylon elastomer, 1.5 parts of anti-ultraviolet filler, 10 parts of polyethylene and 0.6 parts of antioxidant.

[0052] Example 3 The embodiment refers to the polypropylene material for corrosion-resistant pipelines and the preparation method thereof in the embodiment 1, and the only difference is that the dosages of the components are different, and the polypropylene graft is different.

[0053] The polypropylene material for corrosion-resistant pipelines in the embodiment comprises the following components in parts by weight: 57.9 parts of polypropylene matrix resin, 15 parts of polypropylene graft, 5 parts of toughening agent, 10 parts of nylon elastomer, 1.5 parts of anti-ultraviolet filler, 10 parts of polyethylene and 0.6 parts of antioxidant.

[0054] The polypropylene grafting product is prepared by solution grafting method with the following components: homopolymer polypropylene (melt flow index at 230℃ / 2.16kg is 20g / 10min), block copolymer polypropylene (melt flow index at 230℃ / 2.16kg is 8g / 10min), glycidyl methacrylate and 1,3-1,4 di-t-butyl peroxide isopropylbenzene in a mass ratio of 50:50:4:0.3; specifically, the homopolymer polypropylene and the block copolymer polypropylene are dissolved in xylene (the mass of xylene is 10 times the mass of the homopolymer polypropylene and the block copolymer polypropylene), the dissolving temperature is 130-140℃, after complete dissolution, the initiator and the glycidyl methacrylate are slowly added, the temperature is raised to 140℃, and the reaction is carried out for 6h, then the product is precipitated by using acetone, and then is filtered and dried to obtain the polypropylene grafting product, the grafting rate of the glycidyl methacrylate is 3.8%, the molecular weight distribution width is 2.2, and the number average molecular weight is 20,000.

[0055] Example 4 This example refers to the polypropylene material for corrosion-proof pipeline and the preparation method thereof in Example 1, and the difference is only in the different use amounts of the components.

[0056] The polypropylene material for corrosion-proof pipeline in this example comprises the following components in parts by weight: polypropylene base resin 57.9 parts, polypropylene grafting product 20 parts, toughening agent 5 parts, nylon elastomer 5 parts, anti-ultraviolet filler 1.5 parts, polyethylene 10 parts and antioxidant 0.6 part.

[0057] Example 5 This example refers to the polypropylene material for corrosion-proof pipeline and the preparation method thereof in Example 1, and the difference is only in the different use amounts of the components.

[0058] The polypropylene material for corrosion-proof pipeline in this example comprises the following components in parts by weight: polypropylene base resin 47.9 parts, polypropylene grafting product 20 parts, toughening agent 5 parts, nylon elastomer 15 parts, anti-ultraviolet filler 1.5 parts, polyethylene 10 parts and antioxidant 0.6 part.

[0059] Example 6 This example refers to the polypropylene material for corrosion-proof pipeline and the preparation method thereof in Example 1, and the difference is only in the different use amounts of the components.

[0060] The polypropylene material for corrosion-proof pipeline in this example comprises the following components in parts by weight: polypropylene base resin 57.9 parts, polypropylene grafting product 20 parts, toughening agent 5 parts, nylon elastomer 10 parts, anti-ultraviolet filler 1.5 parts, polyethylene 5 parts and antioxidant 0.6 part.

[0061] Example 7 This example refers to the polypropylene material for anti-corrosion pipeline and its preparation method of example 1, the difference is only that the amount of each component is different.

[0062] The polypropylene material for anti-corrosion pipeline of this example comprises the following components by weight fraction: polypropylene matrix resin 47.9 parts, polypropylene graft 20 parts, toughening agent 5 parts, nylon elastomer 10 parts, anti-ultraviolet filler 1.5 parts, polyethylene 15 parts and antioxidant 0.6 parts.

[0063] Comparative example 1 Comparative example 1 provides a polypropylene material comprising the following components by weight fraction: polypropylene matrix resin 55 parts, polypropylene graft 15 parts, tetrabromobisphenol A 10 parts, curing agent 10 parts, curing accelerator 3 parts, toughening agent 5 parts, nano zinc oxide 2 parts, thermal oxidative stabilizer 0.3 parts.

[0064] The polypropylene matrix resin is a block copolymerized polypropylene with a melt flow index of 2 g / 10 min at 230℃ / 2.16 kg; the grafting rate of the polypropylene graft is 1%, the number average molecular weight is 110,000, and the molecular weight distribution is 3.2; the curing agent is o-cresol formaldehyde epoxy resin; the curing accelerator is maleic anhydride; the toughening agent is polyolefin elastomer; the nano zinc oxide is YC-ZNG40 (Shanghai Yingcheng New Material Co., Ltd.), and the thermal oxidative stabilizer is B215, which is prepared by a twin-screw extruder with an extrusion temperature of 140℃ for the first zone, 160℃ for the second zone, 180℃ for the third zone, 180℃ for the fourth zone, 180℃ for the fifth zone, 180℃ for the sixth zone, 180℃ for the seventh zone, 180℃ for the eighth zone, 180℃ for the die, 200 RPM for the main machine speed, and 5 HZ for the feeding. The preparation method of the polypropylene graft mainly comprises melt grafting of homopolymerized polypropylene (melt flow index of 20 g / 10 min at 230℃ / 2.16 kg), maleic anhydride and 1,1-di-tert-butyl peroxide 3,3,5-cyclohexane at a mass ratio of 100:2:0.2, and the specific melt grafting reaction temperature is 190℃.

[0065] Comparative example 2 Comparative example 2 refers to the polypropylene material for anti-corrosion pipeline and its preparation method of example 1, the difference is that the polypropylene graft is different.

[0066] The polypropylene graft of comparative example 2 is mainly prepared by melt grafting of homopolymerized polypropylene (melt flow index of 20 g / 10 min at 230℃ / 2.16 kg), maleic anhydride and 1,1-di-tert-butyl peroxide 3,3,5-cyclohexane at a mass ratio of 100:2:0.2, and the specific melt grafting reaction temperature is 190℃; the prepared polypropylene graft has a maleic anhydride grafting rate of 1%, a molecular weight distribution width of 3.2, and a number average molecular weight of 110,000.

[0067] Comparative Example 3 Comparative Example 3 refers to the polypropylene material for corrosion- resistant pipes and the preparation method thereof of Example 1, except that the amounts of the components are different.

[0068] The polypropylene material of Comparative Example 3 comprises the following components by weight fraction: polypropylene base resin 62.9 parts, polypropylene grafting material 20 parts, toughening agent 5 parts, anti-ultraviolet filler 1.5 parts, polyethylene 10 parts, and antioxidant 0.6 parts.

[0069] Comparative Example 4 Comparative Example 4 refers to the polypropylene material for corrosion- resistant pipes and the preparation method thereof of Example 1, except that the amounts of the components are different.

[0070] The polypropylene material of Comparative Example 4 comprises the following components by weight fraction: polypropylene base resin 42.9 parts, polypropylene grafting material 20 parts, toughening agent 5 parts, nylon elastomer 20 parts, anti-ultraviolet filler 1.5 parts, polyethylene 10 parts, and antioxidant 0.6 parts.

[0071] Comparative Example 5 Comparative Example 5 refers to the polypropylene material for corrosion- resistant pipes and the preparation method thereof of Example 1, except that the amounts of the components are different.

[0072] The polypropylene material of Comparative Example 5 comprises the following components by weight fraction: polypropylene base resin 62.9 parts, polypropylene grafting material 20 parts, toughening agent 5 parts, nylon elastomer 10 parts, anti-ultraviolet filler 1.5 parts, and antioxidant 0.6 parts.

[0073] Comparative Example 6 Comparative Example 6 refers to the polypropylene material for corrosion- resistant pipes and the preparation method thereof of Example 1, except that the amounts of the components are different.

[0074] The polypropylene material of Comparative Example 6 comprises the following components by weight fraction: polypropylene base resin 42.9 parts, polypropylene grafting material 20 parts, toughening agent 5 parts, nylon elastomer 10 parts, anti-ultraviolet filler 1.5 parts, polyethylene 20 parts, and antioxidant 0.6 parts.

[0075] Experimental Example The properties of the polypropylene materials of different examples and comparative examples were tested as follows, and the test results are shown in Table 1.

[0076] Melt flow rate: the flow rate of the melt at 230℃ / 2.16kg was tested, and the test method was carried out according to GB / T 3682; Yield strength: the test method was carried out according to GB / T 1040.2; Tensile strength and nominal strain at break: the test method was carried out according to GB / T 1040.2; Vicat softening point: test method according to GB / T 1633; Peeling strength: test the peeling strength of the test sample from the epoxy, test method according to SY / T 7041-2016; the preparation of the test sample includes: preparing the anti-corrosion coating on the anti-corrosion steel pipe production line, specifically first heating the steel pipe by medium frequency, then spraying the epoxy powder on the surface of the steel pipe, then extruding the polypropylene material of the corresponding example or the comparative example by a single screw extruder to obtain a sheet, and winding the sheet in a molten state on the surface of the steel pipe which has been sprayed with the epoxy powder coating, and after water cooling, the anti-corrosion coating is prepared; wherein the thickness of the epoxy powder coating is 200 μm, and the thickness of the polypropylene material sheet is 2.5 mm; the anti-corrosion coating is cut along the circumferential direction to form a strip with a width of about 20 mm and a length of about 10 cm, the anti-corrosion coating should be cut through when cutting, and one end should be pried up, and the force gauge is used to pull up the anti-corrosion coating at a speed of 10 mm / min perpendicular to the surface of the steel pipe, and the peeling strength at 20±5℃ and 110±5℃ is tested respectively, and the stable value of the force gauge is recorded.

[0077] Table 1 Test results of different polypropylene materials

[0078] From the above test results, it can be seen that the polypropylene material of the present application has the dual characteristics of the outer layer polypropylene and the adhesive, and in the production process of the anti-corrosion pipeline, it is not restricted by the adhesive, simplifying the production process and equipment, not only improving the stability of product performance, but also reducing the consumption of site and energy.

[0079] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. Polypropylene material for anti-corrosion pipelines, characterized by: It comprises the following components in parts by weight: 50-80 parts of polypropylene matrix resin, 5-20 parts of polypropylene grafted material, 5-15 parts of toughening agent, 5-15 parts of nylon elastomer, 1-3 parts of anti-ultraviolet filler, 5-15 parts of polyethylene and 0.3-1 part of antioxidant; In the polypropylene grafted product, the grafting rate is 2% to 4.5%.

2. The polypropylene material for anti-corrosion pipes according to claim 1, characterized in that: The polypropylene graft has at least one of the following characteristics: (1) The number average molecular weight of the polypropylene graft is 10,000 to 80,000; (2) The molecular weight distribution width of the polypropylene graft is 1.5 to 3; (3) In the polypropylene graft, the grafting monomer includes glycidyl methacrylate and / or maleic anhydride.

3. The polypropylene material for anti-corrosion pipes according to claim 1, characterized in that: The polypropylene grafted product is mainly prepared by grafting reaction of polypropylene resin, grafting monomer and initiator in solvent; The amount of the grafting monomer is 2 wt% to 5 wt% of the polypropylene resin; the amount of the initiator is 0.1 wt% to 0.5 wt% of the polypropylene resin.

4. The polypropylene material for anti-corrosion pipes according to claim 3, characterized in that: The polypropylene resin has a melt flow rate of 2 to 30 g / 10 min at 230° C. and 2.16 kg.

5. The polypropylene material for anti-corrosion pipes according to claim 1, characterized in that: The Shore D hardness of the nylon elastomer is 40-75, the Vicat softening point is 130-170° C., and the melting point is 150-180° C.

6. The polypropylene material for anti-corrosion pipes according to claim 1, characterized in that: The polyethylene includes at least one of LDPE and LLDPE; The polyethylene has a melt flow rate of 1 to 10 g / 10 min at 190° C. and 2.16 kg.

7. The polypropylene material for anti-corrosion pipes according to claim 1, characterized in that: The polypropylene matrix resin includes at least one of homopolymer polypropylene, random copolymer polypropylene and block copolymer polypropylene; The polypropylene matrix resin has a melt flow rate of 0.1 to 2 g / 10 min at 230° C. and 2.16 kg.

8. The polypropylene material for anti-corrosion pipes according to claim 1, characterized in that: Has at least one of the following characteristics: (1) The toughening agent includes at least one of EPDM, POE, POP, propylene-based elastomer and SEBS; (2) The toughening agent has a melt flow rate of 0.1 to 5 g / 10 min at 190° C. and 2.16 kg; (3) The anti-ultraviolet filler includes titanium dioxide and / or carbon black.

9. The method for preparing the polypropylene material for anti-corrosion pipes according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: weighing each component in proportion, mixing, and extruding to form granules.

10. Use of the polypropylene material for anti-corrosion pipes according to any one of claims 1 to 8 in the preparation of anti-corrosion pipes.

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