Polyphenylene sulfide pipe and preparation method thereof

Abstract

The invention discloses a polyphenylene sulfide pipe and a preparation method thereof. The pipe is prepared from the following components in parts by weight: 60 to 100 parts of polyphenylene sulfide, 10 to 40 parts of toughening agent, 0.01 to 0.2 part of antioxidant and 2 to 5 parts of carbon black master batch. According to the preparation method, a dual toughening method is adopted, firstly, a grafted modified hydrogenated styrene-butadiene block copolymer and ethylene-acrylate-glycidyl methacrylate copolymer compound toughening agent serves as a toughening agent of an oil-gas-resistant medium, and after the resin is toughened and makes contact with the oil-gas medium for a long time, the oil-gas-resistant medium can be cured, and the oil-gas-resistant medium can be obtained. The toughness is kept stable. And secondly, in the forming process of the pipe, the cooling rate after the pipe is extruded is controlled through temperature control gradient cooling, the crystallization behavior of the pipe is regulated and controlled, and the purpose of secondary toughening is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of polyphenylene sulfide pipes, and in particular to a polyphenylene sulfide pipe and a preparation method thereof. Background Art

[0003] Polyphenylene sulfide (PPS) has now achieved domestic production of raw materials at a price of 60,000 to 80,000 yuan per ton, about half of the imported materials, and is widely used in the fields of electronics, automobiles, machinery and chemicals. Therefore, PPS has great potential to be developed into a special material for high-temperature resistant pipes for oil and gas fields. However, there are no reports on pipe products based on domestic PPS resins. The main reason is that two major technical problems limit the application of PPS in the field of pipes for oil and gas fields. On the one hand, the performance of PPS resin is insufficient. The performance of domestic PPS resin is compared with the commonly used thermoplastic plastic pipe materials in domestic oil fields, such as HDPE, PA and PVDF. It is found that PPS resin has obvious advantages in strength, modulus and temperature resistance, but the toughness is significantly different from the other three materials, and it cannot meet the requirements of material toughness in the process of internal insertion and flanging of pipes during application; on the other hand, the extrusion molding process of pipes with specifications above DN40 is immature, which restricts the application of PPS materials in the field of pipes.

[0004] At present, PPS toughening agents are used to increase PPS toughening. However, PPS toughening agents have poor resistance to oil and gas media. After toughening, the resin is in contact with oil and gas media for a long time and is easily extracted, resulting in poor toughening effect and failure to meet the requirements for the use of oil and gas pipeline materials. Therefore, how to ensure the toughness of polyphenylene sulfide has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The object of the present invention is to provide a polyphenylene sulfide pipe and a preparation method thereof, so as to solve the above-mentioned technical problems.

[0006] To achieve the above object, the present invention provides a polyphenylene sulfide pipe, the pipe comprising: 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant, and 2 to 5 parts by weight of a carbon black masterbatch;

[0007] The toughening agent comprises a composite toughening agent composed of a graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and an ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA).

[0008] The present invention also provides a method for preparing a polyphenylene sulfide pipe, the method comprising: mixing 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant, and 2 to 5 parts by weight of a carbon black masterbatch to obtain a premix; extruding the premix to obtain an initial pipe; performing a temperature-controlled gradient cooling process on the initial pipe to obtain a high-toughness polyphenylene sulfide pipe;

[0009] The toughening agent comprises a composite toughening agent composed of a graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and an ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA).

[0010] Technical effects and advantages of the present invention:

[0011] The invention provides a high-toughness polyphenylene sulfide pipe, which comprises: 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant and 2 to 5 parts by weight of a carbon black masterbatch; wherein the toughening agent comprises: a composite toughening agent composed of a graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and an ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA).

[0012] The present invention adopts a double toughening method. First, a toughening agent resistant to oil and gas media is selected and screened (a composite toughening agent composed of grafted modified hydrogenated styrene-butadiene block copolymer (SEBS) and ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA)). After the resin is toughened, its toughness remains stable after long-term contact with oil and gas media. Secondly, during the pipe forming process, the cooling rate of the pipe after extrusion is controlled to regulate the crystallization behavior of the pipe, thereby achieving the purpose of secondary toughening.

[0013] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a flow chart of the preparation method of polyphenylene sulfide pipe. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings provided by the present invention, and the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0016] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0017] The invention provides a polyphenylene sulfide pipe, which comprises: 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant and 2 to 5 parts by weight of a carbon black masterbatch; wherein the toughening agent comprises: a composite toughening agent composed of a graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and an ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA), and the mass ratio of the graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) to the ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA) is 5:1 to 3:1.

[0018] The present invention also provides a method for preparing a polyphenylene sulfide pipe, such as Figure 1 As shown, the method includes:

[0019] 1. Mix 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant and 2 to 5 parts by weight of a carbon black masterbatch to obtain a premix.

[0020] Specifically: 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant and 2 to 5 parts by weight of a carbon black masterbatch are premixed in a high-speed mixer, the speed of the high-speed mixer is not less than 400 r / min, and the mixing time is not less than 30 minutes, so as to obtain a premix.

[0021] Wherein, the polyphenylene sulfide includes: high molecular weight linear polyphenylene sulfide resin, and the average molecular weight is 50,000 to 70,000.

[0022] The toughening agent comprises: a composite toughening agent composed of a graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and an ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA); and the mass ratio of the graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and the ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA) is 5:1 to 3:1.

[0023] The antioxidant consists of a main antioxidant and an auxiliary antioxidant, wherein the weight ratio of the main antioxidant to the auxiliary antioxidant is 1:(0.5-5); the main antioxidant includes: antioxidant 1010, and the auxiliary antioxidant includes: antioxidant 168.

[0024] The carbon black masterbatch contains 43% carbon black, 50% inorganic filler and 7% resin carrier. Specifically, the inorganic filler includes calcium carbonate with a fineness of 1000 mesh, and the resin carrier includes low molecular weight linear polyphenylene sulfide resin with a weight average molecular weight of 10,000 to 30,000.

[0025] 2. Extruding the premix to obtain an initial pipe.

[0026] Specifically, the premix is ​​dried at a temperature of 120 to 130°C for 2 to 3 hours. The dried premix is ​​melt-blended and extruded using a conical counter-rotating twin-screw extruder. The six-stage extruder barrel temperature and the extrusion head temperature are set to 155 to 160°C, 240 to 260°C, 290 to 310°C, 290 to 320°C, 290 to 320°C and 300 to 330°C in stages. The screw speed is 20 to 30 r / min and the extrusion pressure is 3 to 7 MPa.

[0027] 3. The initial pipe is subjected to temperature-controlled gradient cooling treatment to obtain a high-toughness polyphenylene sulfide pipe.

[0028] Specifically, the pipe is cooled by temperature control gradient after extrusion, the first stage of vacuum sizing box cooling medium temperature is 240-260℃, the second stage of spray box temperature is 150-200℃, and the third stage of spray box temperature is room temperature cooling water. The pipe cooled to room temperature is cut to a fixed length to obtain high-toughness polyphenylene sulfide pipe.

[0029] In order to better explain the present invention, examples are also provided below.

[0030] Example 1

[0031] Embodiment 1 of the present invention discloses a polyphenylene sulfide pipe, which comprises the following components by weight:

[0032] 60 parts of polyphenylene sulfide, wherein the weight average molecular weight of the polyphenylene sulfide is 50,000.

[0033] 10 parts of a toughening agent, wherein the toughening agent is a composite toughening agent, wherein the mass ratio of the graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and the ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA) is 5:1.

[0034] 0.01 parts of an antioxidant, wherein the antioxidant consists of a primary antioxidant and an auxiliary antioxidant, wherein the weight ratio of the primary antioxidant to the auxiliary antioxidant is 1:0.5, the primary antioxidant is antioxidant 1010, and the auxiliary antioxidant is antioxidant 168.

[0035] 2 parts of carbon black masterbatch, wherein the carbon black content of the carbon black masterbatch is 43%, the inorganic filler content is 50%, the resin carrier content is 10%, the inorganic filler calcium carbonate fineness is 1000 mesh, and the resin carrier is a low molecular weight linear polyphenylene sulfide resin with a weight average molecular weight of 10,000.

[0036] Polyphenylene sulfide pipes were prepared by the following method:

[0037] Step S1, premix the raw materials in a high-speed mixer according to proportion, with the high-speed mixer rotating at 400 r / min and the mixing time at 30 min to obtain a premix.

[0038] Step S2: drying the premix at a temperature of 120° C. for 2 h.

[0039] Step S3, melt-blending and extruding the dried premix using a conical counter-rotating twin-screw extruder, and setting the six-stage extruder barrel temperature and the extrusion head temperature to 155°C, 240°C, 290°C, 290°C, 290°C and 300°C in stages, the screw speed is 20r / min, and the extrusion pressure is 3MPa to obtain a pipe.

[0040] Step S4, after the tube is extruded, it is subjected to temperature-controlled gradient cooling, the temperature of the cooling medium in the first section of the vacuum sizing box is 240°C, the temperature of the second section of the spray box is 150°C, and the temperature of the third section of the spray box is room temperature cooling water.

[0041] Step S5, cutting the pipe cooled to room temperature into fixed lengths to obtain a high-toughness polyphenylene sulfide pipe.

[0042] Example 2

[0043] Embodiment 2 of the present invention discloses a polyphenylene sulfide pipe, which comprises the following components by weight:

[0044] 100 parts of polyphenylene sulfide, wherein the weight average molecular weight of the polyphenylene sulfide is 70,000.

[0045] 40 parts of a toughening agent, wherein the toughening agent is a composite toughening agent, wherein the mass ratio of the graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and the ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA) is 3:1.

[0046] 0.01 parts of an antioxidant, wherein the antioxidant consists of a primary antioxidant and an auxiliary antioxidant, wherein the weight ratio of the primary antioxidant to the auxiliary antioxidant is 1:5, the primary antioxidant is antioxidant 1010, and the auxiliary antioxidant is antioxidant 168.

[0047] 2 parts of carbon black masterbatch, wherein the carbon black content of the carbon black masterbatch is 43%, the inorganic filler content is 50%, the resin carrier content is 10%, the inorganic filler calcium carbonate fineness is 1000 mesh, and the resin carrier is a low molecular weight linear polyphenylene sulfide resin with a weight average molecular weight of 30,000.

[0048] Polyphenylene sulfide pipes were prepared by the following method:

[0049] Step S1, premix the raw materials in a high-speed mixer according to proportion, with the high mixer speed of 500r / min and the mixing time of 50min to obtain a premix.

[0050] Step S2: drying the premix at a temperature of 130° C. for 3 h.

[0051] Step S3, melt-blending and extruding the dried premix using a conical counter-rotating twin-screw extruder, and setting the six-stage extruder barrel temperature and the extrusion head temperature to 160°C, 260°C, 310°C, 320°C, 320°C and 330°C in stages, the screw speed is 30r / min, and the extrusion pressure is 7MPa to obtain a pipe.

[0052] Step S4, after the tube is extruded, it is subjected to temperature-controlled gradient cooling, the temperature of the cooling medium in the first section of the vacuum sizing box is 260°C, the temperature of the second section of the spray box is 200°C, and the temperature of the third section of the spray box is room temperature cooling water.

[0053] Step S5, cutting the pipe cooled to room temperature into fixed lengths to obtain a high-toughness polyphenylene sulfide pipe.

[0054] Comparative Example 1:

[0055] A method for preparing a pure polyphenylene sulfide pipe, the method comprising the following steps:

[0056] Step S1, drying the pure polyphenylene sulfide resin at a temperature of 125° C. for 2.5 hours.

[0057] Step S2, melt-extrude the dried pure polyphenylene sulfide resin using a conical counter-rotating twin-screw extruder, and set the six-stage extruder barrel temperature and extrusion head temperature to 155°C, 240°C, 290°C, 295°C, 300°C and 305°C in stages, the screw speed is 20r / min, and the extrusion pressure is 3MPa to obtain a pipe.

[0058] Step S3, after the tube is extruded, it is subjected to temperature-controlled gradient cooling, the temperature of the cooling medium in the first section of the vacuum sizing box is 240°C, the temperature of the second section of the spray box is 150°C, and the temperature of the third section of the spray box is room temperature cooling water.

[0059] Step S4, cutting the pipe cooled to room temperature into fixed lengths to obtain pure polyphenylene sulfide pipes.

[0060] The above embodiments and comparative examples were tested:

[0061] With reference to GBT 8804.1-2003 Determination of tensile properties of thermoplastic pipes Part 1 General principles of test methods, the tensile mechanical properties of the pipes were tested. The test results are shown in the table below.

[0062] Table 1 Comparative Example 1 Tensile Mechanical Properties Test of Pure Polyphenylene Sulfide Pipe

[0063] Sample No. Elongation at break (%) Yield strength (MPa) Elastic modulus(GPa) 1 5.5 86.1 4.0 2 3.1 85.1 4.4 3 3.3 85.3 3.6 4 3.8 86.0 4.5 5 3.4 86.0 3.7 average value 3.8 85.7 4.0

[0064] Table 2 Tensile mechanical properties test of polyphenylene sulfide pipe toughened by bio-based elastomer in Example 1

[0065]

[0066]

[0067] Table 3 Tensile mechanical properties test of polyphenylene sulfide pipe toughened by bio-based elastomer in Example 2

[0068] Sample No. Elongation at break (%) Yield strength (MPa) Elastic modulus(GPa) 1 37.6 45.2 1.9 2 41.1 47.1 2 3 37.6 46.1 1.9 4 40.3 45.5 1.9 5 38.3 45.5 2.1 average value 39.0 45.9 2.0

[0069] Comparing the test results in Tables 2 and 3 with those in Table 1, it can be seen that after toughening, the toughness of the pipe is significantly improved, as shown by a significant increase in the elongation at break. The increase in toughness leads to a decrease in yield strength and elastic modulus, but the yield strength and elastic modulus after toughening are still higher than those of thermoplastics currently used in oil fields, meeting the requirements of SY / T 7415-2018.

[0070] The present invention also provides a preparation device for polyphenylene sulfide pipes, the device comprising: a mixing unit for mixing 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant and 2 to 5 parts by weight of a carbon black masterbatch to obtain a premix; an extrusion unit for extruding the premix to obtain an initial pipe; a cooling unit for performing a temperature-controlled gradient cooling treatment on the initial pipe to obtain a high-toughness polyphenylene sulfide pipe; wherein the toughening agent comprises a composite toughening agent composed of a graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and an ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA).

[0071] Since the content protected by this device is similar to that protected by the above method, no further introduction will be given here. Please refer to the discussion section of the above method for details.

[0072] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A polyphenylene sulfide pipe, characterized in that: The pipe comprises: 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant, and 2 to 5 parts by weight of a carbon black masterbatch; The toughening agent comprises a composite toughening agent composed of a graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and an ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA).

2. A method for preparing a polyphenylene sulfide pipe, characterized in that: The method comprises: Mixing 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant, and 2 to 5 parts by weight of a carbon black masterbatch to obtain a premix; Extruding the premix to obtain an initial pipe; Performing a temperature-controlled gradient cooling process on the initial pipe to obtain a high-toughness polyphenylene sulfide pipe; The toughening agent comprises a composite toughening agent composed of a graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and an ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA).

3. The method according to claim 2, characterized in that The polyphenylene sulfide includes: a high molecular weight linear polyphenylene sulfide resin, and the weight average molecular weight of the polyphenylene sulfide resin is 50,000 to 70,000.

4. The method according to claim 2, characterized in that: The mass ratio of the graft-modified hydrogenated styrene-butadiene block copolymer (SEBS) and the ethylene-acrylate-glycidyl methacrylate copolymer (E-MA-GMA) in the composite toughening agent is 5:1 to 3:

1.

5. The method according to claim 2, characterized in that: The antioxidants include: primary antioxidants and auxiliary antioxidants; The weight ratio of the primary antioxidant to the secondary antioxidant is 1:(0.5-5); the primary antioxidant includes antioxidant 1010, and the secondary antioxidant includes antioxidant 168.

6. The method according to claim 2, characterized in that The carbon black masterbatch contains 43% carbon black, 50% inorganic filler and 7% resin carrier. Wherein, the inorganic filler comprises: calcium carbonate with a fineness of 1000 meshes, and the resin carrier comprises: low molecular weight linear polyphenylene sulfide resin with a weight average molecular weight of 10,000 to 30,000.

7. The method according to claim 2, characterized in that The method comprises mixing 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant and 2 to 5 parts by weight of a carbon black masterbatch to obtain a premix, comprising: using a high-speed mixer to mix 60 to 100 parts by weight of polyphenylene sulfide, 10 to 40 parts by weight of a toughening agent, 0.01 to 0.2 parts by weight of an antioxidant and 2 to 5 parts by weight of a carbon black masterbatch to obtain a premix; The mixing conditions include: the high speed mixer is not less than 400r / min, and the mixing time is not less than 30min.

8. The method according to claim 2, characterized in that: Before the premix is ​​extruded, the method further includes: drying the premix; The drying conditions include: a drying temperature of 120 to 130° C. and a drying time of 2 to 3 hours.

9. The method according to claim 2, characterized in that: Extruding the premix to obtain an initial pipe, comprising: melt-blending and extruding the premix using a conical counter-rotating twin-screw extruder to obtain an initial pipe; Among them, the conditions for the co-extrusion include: the six-stage extruder barrel temperature of the premix using a conical counter-rotating twin-screw extruder is set in stages to: 155-160°C, 240-260°C, 290-310°C, 290-320°C, 290-320°C and 300-330°C; the screw speed is 20-30r / min; and the extrusion pressure is 3-7MPa.

10. The method according to claim 2, characterized in that The temperature-controlled gradient cooling process includes: the temperature of the cooling medium in the first stage vacuum sizing box is 240-260° C., the temperature of the second stage spray box is 150-200° C., and the temperature of the third stage spray box is normal temperature cooling water.

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