PVC-M pipe composition as well as preparation method and application thereof

Abstract

The invention discloses a PVC-M pipe composition as well as a preparation method and application thereof, and belongs to the technical field of plastic processing. The high-strength PVC material is prepared from the following components in parts by weight: 100 parts of PVC resin, 1-3 parts of a heat stabilizer, 1-4 parts of a modified MBS toughening agent, 6-10 parts of MBS resin, 0.8-3 parts of an auxiliary impact modifier, 1-3 parts of a lubricant, 0.07-0.12 part of an antioxidant and 1.5-3 parts of filler. The preparation method comprises the following steps: adding the components into a high-speed mixer with an exhaust port in parts by weight, heating, mixing at a low speed and a high speed, and extruding and granulating by adopting a conical twin-screw extruder to obtain the PVC-M pipe composition. The PVC-M pipe composition disclosed by the invention has relatively high rigidity and relatively good toughness and processability, can meet the processing requirements of PVC-M pipes, and can be used for manufacturing fluid conveying pressure pipelines.

Description

Technical Field

[0001] The invention discloses a PVC-M pipe material composition and a preparation method and application thereof, belonging to the technical field of plastic processing. Background Art

[0002] Polyvinyl chloride (PVC) is a general-purpose thermoplastic with excellent comprehensive properties and is recognized as an excellent fluid transport pipeline.

[0003] Research has found that by blending and modifying the PVC formula and combining it with advanced processing technology, impact-resistant modified polyvinyl chloride (Modified PVC, abbreviated as PVC-M) pipes with both strength and toughness can be produced. The modifier acts like rubber particles in the PVC matrix, giving the material good toughness and improving the ability of the pipe to resist point loads. Therefore, in addition to the characteristics of ordinary PVC-U pipes, PVC-M pipes also have excellent toughness and impact resistance. Compared with ordinary PVC-U pipes, the impact resistance of PVC-M pipes is significantly improved, and they can better resist minor scratches, point loads, and uneven declines in the foundation during the installation and transportation of pipes; PVC-M pipes can effectively resist water hammer and reduce damage to pipelines during operation.

[0004] Since high-impact PVC pipes are far superior to PVC-U pipes in many aspects of performance (such as impact toughness and safety factor), they have broad market prospects in urban and rural municipal engineering construction, building water supply and mining applications, and will gradually replace ordinary rigid PVC water supply pipes.

[0005] Patent CN102863712B is a high-impact polyvinyl chloride pipe, which includes the following components by weight: 100 parts of PVC resin, 1.0-3.0 parts of heat stabilizer, 2.3-3.2 parts of lubricant, 0-8 parts of filler, 8-11.5 parts of toughening agent, 0.2-0.7 parts of colorant, and 2-4 parts of ASA resin. The pipe has the high strength of PVC-U pipe, with a tensile strength of 45-48MPa and a yield strength of 45-48MPa, and has good impact resistance, with a simple beam notch impact strength of 73-100kJ / m2, and its flexibility is also improved: the elongation at break reaches 146.1-166.8%. It also has good pressure resistance and weather resistance. In the hydraulic test, the PVC pipe of the present invention has no cracks and no leakage. If used for laying a water pipe network, it can ensure that the leakage rate of the water pipe network is below 5%, which is better than the existing PVC pipe.

[0006] Patent CN102952354B belongs to the field of polymer materials, and mainly relates to a special material composition for high elongation PVC-M pipes, which is made of the following components in parts by weight: PVC resin, MBS-561, organic tin stabilizer, composite anti-aging agent, lubricant, filler, processing aid ACR and titanium dioxide. The pipe prepared by the present invention retains the higher tensile strength of PVC-U while greatly improving the elongation of PVC pipes, and has the advantages of good processing performance. In addition, the impact strength is also greatly improved, which can effectively resist foundation settlement, point load and seismic performance. The price per meter is equivalent to that of PVC-U pipes, lower than that of PE pipes, and has broad market prospects.

[0007] Patent CN103360696A belongs to the field of polymer processing materials, and mainly relates to a low-energy consumption and high-extrusion output PVC-M pipe composition, which is made of the following components by weight: 100 parts of PVC resin, 3-7 parts of processing modifier, 4.5-8.0 parts of heat stabilizer, 6-12 parts of toughening agent, 0.5-1.0 parts of hindered phenol antioxidant, 1.0-2.0 parts of lubricant, 1-5 parts of filler, and 0-2.0 parts of colorant. The large-diameter pipes and small-diameter pipes produced by the low-energy consumption and high-extrusion output PVC-M pipe composition of the present invention have lower extrusion current and higher pulling speed, solving the problems of difficult extrusion, low output and high energy consumption in the production process of PVC-M pipes.

[0008] In the prior art, PVC-M pipes are mainly treated with traditional impact modifiers such as ACR, MBS, CPE, EVA, and PMMA, either alone or in combination, which lack specificity for PVC-M pipes and result in unsatisfactory modification effects, especially in meeting the requirements for high-speed impact performance and pressure resistance of PVC-M pipes. Summary of the invention

[0009] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art and provide a PVC-M pipe composition and a preparation method and application thereof. The prepared PVC-M pipe composition has high rigidity, good toughness and processing performance, and can meet the processing requirements of PVC-M pipes.

[0010] The technical solution of the method adopted by the present invention to solve the technical problem is: the PVC-M pipe composition is made of the following components in parts by weight: 100 parts of PVC resin, 1-3 parts of heat stabilizer, 1-4 parts of modified MBS toughening agent, 6-10 parts of MBS resin, 0.8-3 parts of auxiliary impact modifier, 1-3 parts of lubricant, 0.07-0.12 parts of antioxidant and 1.5-3 parts of filler.

[0011] The PVC-M pipe material composition is prepared from the following components in parts by weight: 100 parts of PVC resin, 1.1-1.3 parts of heat stabilizer, 2-3 parts of modified MBS toughening agent, 7-9 parts of MBS resin, 1-1.5 parts of auxiliary impact modifier, 1.7-1.9 parts of lubricant, 0.08-0.1 parts of antioxidant and 2-2.2 parts of filler.

[0012] The method for preparing the modified MBS toughening agent comprises the following steps: 1) Grind AS resin into AS resin powder, add it into MBS latex and stir evenly to obtain MBS latex mixed solution; 2) During the polymerization process of generating the PVC suspension slurry in the reactor, the MBS latex mixed solution in step 1) is added to the PVC suspension slurry, and stirred evenly for fusion and dispersion; 3) Recovering the unreacted vinyl chloride monomer in the reactor, centrifugally dehydrating the obtained slurry and then drying it to obtain a modified MBS toughening agent.

[0013] The specific operation of step 2) is as follows: add 2000-5000 parts by mass of desalted water, 6-7 parts by mass of 3-5% polyvinyl alcohol aqueous solution, 5-6 parts by mass of 2-4% hydroxypropyl methylcellulose aqueous solution, 0.2-0.3 parts by mass of 70-80% tert-butyl peroxyneodecanoate and 0.4-0.6 parts by mass of 70-80% t-pentyl peroxypivalate into the reactor, evacuate the pressure in the reactor to less than 0.1 MPa, add 1000-2000 parts by mass of vinyl chloride monomer, start stirring, stir and mix at room temperature for 10-20 minutes, then raise the temperature in the reactor to 58.0°C to start the polymerization reaction, and when the pressure drop in the reactor reaches 0.20-0.30 MPa, add 6-7 parts by mass of 2-3% DEHA terminator into the reactor, then add the MBS latex mixture described in step 1), and continue stirring for 20-30 minutes.

[0014] Step 2) The normal temperature is 18-28°C.

[0015] The weight ratio of the solid in the MBS latex of step 2) to the solid in the PVC suspension slurry of step 2) to the AS resin of step 1) is 1:(0.3-0.5):(0.2-0.5).

[0016] The auxiliary impact modifier is ACR; the heat stabilizer is an organic tin heat stabilizer; the lubricant is a compound of an internal lubricant PE wax and an external lubricant microcrystalline wax and paraffin in a weight ratio of 1-2:1-2:1-2.

[0017] The antioxidant is a compound of antioxidant DLTP and antioxidant 1010 in a weight ratio of 1:0.8-1.

[0018] The filler is a mixture of nano calcium and titanium dioxide in a weight ratio of 10:1-2.

[0019] The preparation method of the PVC-M pipe composition comprises the following steps: 1) Weigh PVC resin, heat stabilizer, modified MBS toughening agent, MBS resin, auxiliary impact modifier, lubricant, antioxidant and filler by weight, add them into a high-speed mixer with a vent, heat and mix at a low speed for 5-10 minutes; 2) Then start high-speed mixing; when the mixed powder reaches 180-190°C, discharge the material and cool it to 120-130°C to obtain the mixed material; 3) The mixed material obtained in step 2) is extruded by an extruder and dried for 5-10 hours to obtain a PVC-M pipe composition.

[0020] Preferably, the extruder in step 3) is a conical twin-screw extruder.

[0021] The PVC-M pipe material composition is used in the field of manufacturing fluid transport pressure pipelines.

[0022] Preferably, the polyvinyl alcohol aqueous solution used in step 2) is a PVA80 aqueous solution.

[0023] Preferably, the heat stabilizer is organotin 17MOK from Rohm and Haas Company.

[0024] Preferably, the AS resin is 117C produced by Chi Mei Industrial Co., Ltd. Step 1) The mesh size of the AS resin powder is 200-400 meshes.

[0025] Preferably, the polymerization degree of the PVC resin is 950-1100.

[0026] Preferably, the MBS resin is B-561 from Japan.

[0027] Preferably, MBS latex is made of the following raw materials in parts by weight: 70-85 parts of styrene-butadiene latex, 15-35 parts of methyl methacrylate, 0.1-0.5 parts of initiator, and 200-300 parts of deionized water, wherein the styrene-butadiene latex is made of the following raw materials in parts by weight: 60-65 parts of butadiene, 35-40 parts of styrene, 0.1-0.5 parts of initiator, 1-3.5 parts of composite emulsifier, 0.2-0.5 parts of electrolyte salt, and 200-300 parts of deionized water.

[0028] The composite emulsifier is a mixture of fatty acid soap and sodium dodecylbenzene sulfonate in a weight ratio of 1:2-3. The fatty acid soap is one of potassium laurate soap and potassium coconut oil soap.

[0029] The initiator is one of potassium persulfate, ammonium persulfate or cumene hydroperoxide.

[0030] The electrolyte salt is an organic acid metal salt; preferably, the organic acid metal salt is potassium tartrate.

[0031] Preferably, the preparation method of the MBS latex is as follows: 1) Synthesis of styrene-butadiene latex: deionized water, composite emulsifier, initiator are added to the reactor in sequence, nitrogen is passed, butadiene and styrene are added, the temperature is raised to 50-80°C for reaction, the pressure is controlled below 1Mpa, stirring and reaction is stopped when the pressure is less than 0.2Mpa, and electrolyte salt is added to remove excess composite emulsifier to obtain styrene-butadiene latex; 2) MBS synthesis: Deionized water, styrene-butadiene latex, methyl methacrylate and initiator are added into a reaction kettle for graft polymerization at a polymerization temperature of 50-80°C and a reaction time of 4-7 hours to obtain MBS latex.

[0032] Compared with the prior art, the present invention has the following beneficial effects: The PVC-M pipe composition of the present invention has high rigidity, good toughness and processing performance, and can meet the processing requirements of PVC-M pipes. The modified MBS toughening agent and the MBS resin have a synergistic effect in toughness, so that the prepared PVC-M pipe has a better balance of rigidity and toughness. In addition, the pipe made of the PVC-M pipe composition of the present invention has good heat resistance, impact resistance and pressure bearing capacity, has both strength and toughness, good safety, meets the performance requirements of fluid transportation pipelines, and can be applied to urban and rural municipal engineering construction, building water supply and pressure pipelines for mines. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with specific examples, wherein Example 1 is the best example. The comparative examples are designed to compare the effects of the examples. The main raw materials and additives used in the examples and comparative examples are shown in Table 1. The composition ratios of the raw materials and additives used in the examples and comparative examples are shown in Table 2.

[0034] Polyvinyl chloride, produced by Qilu Branch of Sinopec Co., Ltd., model QS-1050P MBS resin, produced by Zhongyuan Chemical Industry, model B-561; ACR, produced by Zhongshan Dong Ri Ke Chemical Co., Ltd., model ACM-M; AS resin, produced by Chi Mei Industrial Co., Ltd., model 117C; Organic tin, produced by Rohm and Haas Company, model 17MOK; Oxidized polyethylene wax, produced by Honeywell, model 316A; Microcrystalline wax, produced by Hebei Cangzhou Forest Wax Co., Ltd., model 85#; Antioxidant DLTP, produced by Tianjin Lisheng Chemical Factory, industrial grade; Antioxidant 1010, produced by Ciba-Geigy, industrial grade; Fine activated calcium carbonate, produced by Changzhou Calcium Carbonate Co., Ltd., model 1200 mesh; MBS latex is made of the following raw materials in parts by weight: 75 parts of styrene-butadiene latex, 20 parts of methyl methacrylate, 0.3 parts of initiator (ammonium persulfate), and 250 parts of deionized water, wherein the styrene-butadiene latex is made of the following raw materials in parts by weight: 60 parts of butadiene, 40 parts of styrene, 0.4 parts of initiator (ammonium persulfate), 2 parts of composite emulsifier (potassium coconut soap and sodium dodecylbenzene sulfonate in a weight ratio of 1:3), 0.3 parts of potassium tartrate, and 270 parts of deionized water.

[0035] The preparation method of MBS latex comprises the following steps: 1) Synthesis of styrene-butadiene latex: deionized water, composite emulsifier, initiator were added to the reactor in sequence, nitrogen was passed through, butadiene and styrene were added, the temperature was raised to 80°C for reaction, the pressure was controlled below 1 MPa, stirring and reaction was stopped when the pressure was less than 0.2 MPa, potassium tartrate was added to remove the excess composite emulsifier to obtain styrene-butadiene latex; 2) MBS synthesis: Deionized water, styrene butadiene latex, methyl methacrylate and initiator were added into the reaction kettle for graft polymerization at a polymerization temperature of 80°C and a reaction time of 6 hours to obtain MBS latex.

[0036] The preparation method of the modified MBS toughening agent comprises the following steps: 1) Grind the AS resin into 200 mesh AS resin powder, add it into the MBS latex and stir evenly to obtain the MBS latex mixed solution; 2) Add 2000-5000 parts by weight of desalted water, 7 parts by weight of 5% PVA80 aqueous solution, 5 parts by weight of 3% hydroxypropyl methylcellulose aqueous solution, 0.3 parts by weight of 80% tert-butyl peroxyneodecanoate and 0.6 parts by weight of 80% t-pentyl peroxypivalate into the reactor, evacuate the pressure in the reactor to less than 0.1 MPa, add 1500 parts by weight of vinyl chloride monomer, start stirring, stir and mix at room temperature for 15 minutes, then raise the temperature in the reactor to 58.0° C. to start the polymerization reaction, and when the pressure drop in the reactor reaches 0.20 MPa, add 7 parts by weight of 2% DEHA terminator into the reactor, then add the MBS latex mixture in step 1), and continue stirring for 30 minutes; 3) Finally, the unreacted vinyl chloride monomer in the polymerization reactor is recovered, and the obtained slurry is centrifugally dehydrated and then dried to obtain a modified MBS toughening agent; The weight ratio of the solid in the MBS latex of step 2) to the solid in the PVC suspension slurry of step 2) to the AS resin of step 1) is 1:0.3:0.5.

[0037] Table 1 Composition ratio of the embodiments and comparative examples (in parts by weight) .

[0038] The preparation method of the PVC-M pipe composition of the embodiment comprises the following steps: 1) Weigh PVC resin, heat stabilizer, modified MBS toughening agent, MBS resin, auxiliary impact modifier, lubricant, antioxidant and filler according to weight, add them into a high-speed mixer with a vent, heat and mix at a low speed for 10 minutes; 2) Then start high-speed mixing; when the mixed powder reaches 190°C, discharge the material and cool it to 120°C to obtain the mixed material; 3) The mixed material obtained in step 2) is extruded by a conical twin-screw extruder and dried for 6 hours to obtain a PVC-M pipe composition.

[0039] In order to reduce variables, the preparation method of Comparative Examples 1-2 is the same as that of the embodiment.

[0040] Performance Testing Test 1: The mechanical properties of the compositions obtained in the examples and comparative examples were tested according to GB / T 1040.1-2018 Plastic Tensile Properties Test and GB / T 1043.2-2018 Plastic Simple Supported Beam Impact Properties Test Standards. The results are recorded in Table 2.

[0041] Table 2 Mechanical properties test results of the compositions of the embodiments and comparative examples .

[0042] It can be seen from Table 2 that the test results of Example 1 reflect that the material has a better balance of rigidity and toughness, so the formula of Example 1 is selected for the pipe processing test.

[0043] Test 2: The compositions of Example 1 and Comparative Example 1 were used to conduct industrial application tests on PVC-M pipes. The pipe specifications, production equipment, production process parameters, test phenomena and pipe performance test results of the application test are shown in the following table.

[0044] 1. Pipe specifications: Φ160×1.0×4.0.

[0045] 2. Production equipment: Mixer model: SDL-800 / 2500-A mixer unit, Jiangsu Lianguan Technology Development Co., Ltd.; Conical twin-screw extruder model: SJZ65 / 132, Shanghai Li Ke Plastic Machinery Co., Ltd.

[0046] 3. Production process parameters: Extruder temperature (℃) Die head temperature (℃) Die temperature (℃); Settings: 185177167160165165175185205; Actual: 184177170168168166181186209; Feeding speed (r / min): 24.1; Feeding current (A) 0.57; Main engine speed (rpm) 20.1; Host current (A) 38.5-40.5; Traction speed (m / min): 1.38; Vacuum: (MPa) 0.085; Cooling water temperature (℃) 25.

[0047] 4. Test phenomena and pipe performance test results The tested pipe formula has good extrusion processing performance, the extrusion current is moderate, the inner and outer walls of the pipe are smooth and flat, and there is no decomposition yellow line. The performance test results of the produced PVC-M pipe are shown in the table below. All the performance of the pipe can meet the technical index requirements.

[0048] Table 3 Test results of pipe performance of Example 1 and Comparative Example 1 .

[0049] It can be seen from Table 3 that the PVC-M pipe composition obtained in Example 1 has good heat resistance, impact resistance and pressure bearing capacity, has both strength and toughness, good safety, meets the performance requirements of fluid transportation pipelines, and can be used in urban and rural municipal engineering construction, building water supply and mine pressure pipelines.

[0050] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A PVC-M pipe composition, characterized in that: Made from the following components in parts by weight: 100 parts of PVC resin, 1-3 parts of heat stabilizer, 1-4 parts of modified MBS toughening agent, 6-10 parts of MBS resin, 0.8-3 parts of auxiliary impact modifier, 1-3 parts of lubricant, 0.07-0.12 parts of antioxidant, and 1.5-3 parts of filler.

2. A PVC-M pipe composition according to claim 1, characterized in that: The invention is prepared from the following components in parts by weight: 100 parts of PVC resin, 1.1-1.3 parts of heat stabilizer, 2-3 parts of modified MBS toughening agent, 7-9 parts of MBS resin, 1-1.5 parts of auxiliary impact modifier, 1.7-1.9 parts of lubricant, 0.08-0.1 parts of antioxidant and 2-2.2 parts of filler.

3. A PVC-M pipe composition according to claim 1, characterized in that: The method for preparing the modified MBS toughening agent comprises the following steps: 1) Grind AS resin into AS resin powder, add it into MBS latex and stir evenly to obtain MBS latex mixed solution; 2) During the polymerization process of generating the PVC suspension slurry in the reactor, the MBS latex mixed solution in step 1) is added to the PVC suspension slurry, and stirred evenly to achieve fusion and dispersion; 3) Recovering the unreacted vinyl chloride monomer in the reactor, centrifugally dehydrating the obtained slurry and then drying it to obtain a modified MBS toughening agent.

4. A PVC-M pipe composition according to claim 3, characterized in that: The specific operation of step 2) is as follows: add 2000-5000 parts by mass of desalted water, 6-7 parts by mass of 3-5% polyvinyl alcohol aqueous solution, 5-6 parts by mass of 2-4% hydroxypropyl methylcellulose aqueous solution, 0.2-0.3 parts by mass of 70-80% tert-butyl peroxyneodecanoate and 0.4-0.6 parts by mass of 70-80% t-pentyl peroxypivalate into the reactor, evacuate the pressure in the reactor to less than 0.1 MPa, add 1000-2000 parts by mass of vinyl chloride monomer, start stirring, stir and mix at room temperature for 10-20 minutes, then raise the temperature in the reactor to 58.0°C to start the polymerization reaction, and when the pressure drop in the reactor reaches 0.20-0.30 MPa, add 6-7 parts by mass of 2-3% DEHA terminator into the reactor, then add the MBS latex mixture described in step 1), and continue stirring for 20-30 minutes.

5. A PVC-M pipe composition according to claim 3, characterized in that: The weight ratio of the solid in the MBS latex of step 2) to the solid in the PVC suspension slurry of step 2) to the AS resin of step 1) is 1:(0.3-0.5):(0.2-0.5).

6. A PVC-M pipe composition according to claim 1, characterized in that: The auxiliary impact modifier is ACR; the heat stabilizer is an organic tin heat stabilizer; the lubricant is a compound of an internal lubricant PE wax and an external lubricant microcrystalline wax and paraffin in a weight ratio of 1-2:1-2:1-2.

7. A PVC-M pipe composition according to claim 1, characterized in that: The antioxidant is a compound of antioxidant DLTP and antioxidant 1010 in a weight ratio of 1:0.8-1.

8. A PVC-M pipe composition according to claim 1, characterized in that: The filler is a mixture of nano calcium and titanium dioxide in a weight ratio of 10:1-2.

9. A method for preparing a PVC-M pipe composition according to any one of claims 1 to 8, characterized in that: The steps include: 1) Weigh PVC resin, heat stabilizer, modified MBS toughening agent, MBS resin, auxiliary impact modifier, lubricant, antioxidant and filler by weight, add them into a high-speed mixer with a vent, heat and mix at a low speed for 5-10 minutes; 2) Then start high-speed mixing; when the mixed powder reaches 180-190°C, discharge the material and cool it to 120-130°C to obtain the mixed material; 3) The mixed material obtained in step 2) is extruded by an extruder and dried for 5-10 hours to obtain a PVC-M pipe composition.

10. Use of a PVC-M pipe composition according to any one of claims 1 to 8, characterized in that: Application in the field of manufacturing fluid transportation pressure pipelines.