High-quality plastic alloy pipe for natural gas and water supply and drainage and preparation method of high-quality plastic alloy pipe

Abstract

The invention relates to the technical field of pipes, and discloses a high-quality plastic alloy pipe for natural gas and water supply and drainage, the raw material of an inner pipe and the raw material of an outer pipe are independently selected from a combination I or a combination II: the combination I comprises 50-100 parts of PVC-C resin, 5-25 parts of PMMA resin, 0.05-1.0 part of a cross-linking agent, 1-15 parts of silicone powder, 1-8 parts of a stabilizer, 0.1-0.8 part of a lubricant and 2-20 parts of a modifier; the composition II is prepared from 50 to 100 parts of ABS (Acrylonitrile Butadiene Styrene) resin, 5 to 25 parts of PMMA (Polymethyl Methacrylate) resin, 0.05 to 1.0 part of cross-linking agent, 1 to 5 parts of coupling agent, 1 to 8 parts of stabilizer, 0.1 to 1.5 parts of lubricant, 2 to 25 parts of modifier, 0.05 to 0.5 part of pigment, 5 to 25 parts of ammonium octamolybdate and 1 to 15 parts of phosphogypsum. The composite pipeline provided by the invention not only solves the problem of poor flame retardance of a PE and PP-R composite pipe and a full-plastic pipeline and achieves the effect of good flame retardance, but also improves the PE and PP-R wall thickness and the pressure-bearing performance by 50-80% compared with the existing same steel-plastic composite pipeline.

Description

Technical Field

[0001] The invention relates to the technical field of pipes, in particular to a high-quality plastic alloy pipe for natural gas and water supply and drainage and a preparation method thereof. Background Art

[0002] At present, pipes are mainly divided into two categories: plastic pipes and metal pipes. Plastic pipes generally use PE pipes and metal-reinforced PE composite pipes, which have the problem of not being flame-retardant. Once leakage and fire occur, they will cause rapid combustion, so the safety performance is poor. Although metal pipes have the advantages of high compressive strength, good rigidity, and not easy to deform, they have the defects of poor corrosion resistance and short service life. Both pipes have problems such as inconvenient repair in practical applications. For example, the patent with publication number CN112223854A discloses a water pipe, which is obtained by grafting and compounding the materials between the layers. It can improve the cross-linking degree of the inner and outer pipes, but it is easy to become brittle, and the flexibility and impact strength are poor. For example, the patent with publication number CN113502011A discloses a steel wire mesh skeleton corrugated pipe, which includes a polyethylene inner pipe, a first hot melt adhesive layer, a steel wire mesh layer, a second hot melt adhesive layer and a polyethylene outer pipe. However, there is a problem that the bonding strength between the steel wire mesh layer and the inner and outer pipes is poor, and the weather resistance of the inner and outer pipes is poor. Summary of the invention

[0003] Technical problems solved by the present invention:

[0004] The invention is used to solve the problems of poor bonding strength and weather resistance between inner and outer pipe layers of composite pipes existing in the prior art.

[0005] The technical solution adopted by the present invention is:

[0006] In view of the above technical problems, the purpose of the present invention is to provide a high-quality plastic alloy pipe for natural gas and water supply and drainage and a preparation method thereof. The specific contents are as follows:

[0007] First, the present application provides a high-quality plastic alloy pipe for natural gas and water supply and drainage; including an inner pipe, an intermediate pipe and an outer pipe;

[0008] The raw materials of the inner tube and the outer tube are independently selected from: Combination 1 or Combination 2:

[0009] Combination 1: The raw material components are calculated by weight, including 50-100 parts of PVC-C resin, 5-25 parts of PMMA resin, 0.05-1.0 parts of cross-linking agent, 1-15 parts of silicone powder, 1-8 parts of stabilizer, 0.1-0.8 parts of lubricant, and 2-20 parts of modifier;

[0010] Combination 2: The raw material components are calculated by weight, including 50-100 parts of ABS resin, 5-25 parts of PMMA resin, 0.05-1.0 parts of crosslinking agent, 1-5 parts of coupling agent, 1-8 parts of stabilizer, 0.1-1.5 parts of lubricant, 2-25 parts of modifier, 0.05-0.5 parts of pigment, 5-25 parts of ammonium octamolybdate, and 1-15 parts of phosphogypsum;

[0011] The middle tube comprises a metal layer close to the inner tube and at least one film layer far away from the inner tube; each film layer comprises at least one of maleic acid grafted polyethylene, polyethylene, and maleic acid grafted-ethylene-vinyl acetate copolymer.

[0012] In the present invention, in combination one, the crosslinking agent includes at least one of dicumyl peroxide (DCP), dicumyl hydroperoxide (DBHP), and a silane crosslinking agent; in the aforementioned, the silane crosslinking agent includes vinyl trimethoxy silane (VTMOS) and / or vinyl triethoxy silane (VTEOS).

[0013] The stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, and a rare earth stabilizer; the lubricant includes at least one of stearic acid, paraffin, polyethylene wax, and oxidized polyethylene wax; and the modifier includes at least one of chlorinated polyethylene, MBS, ABS, ACR, nitrile rubber, and EVA.

[0014] In the present invention, in combination 2, the crosslinking agent includes at least one of dicumyl peroxide (DCP), dicumyl hydroperoxide (DBHP), and a silane crosslinking agent; in the aforementioned, the silane crosslinking agent includes vinyl trimethoxy silane (VTMOS) and / or vinyl triethoxy silane (VTEOS). The coupling agent includes at least one of a titanate coupling agent, an aluminate coupling agent, an aluminum titanium coupling agent, and a silane coupling agent; the stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, and a rare earth stabilizer; the lubricant includes at least one of stearic acid, paraffin, polyethylene wax, and oxidized polyethylene wax; the modifier includes at least one of chlorinated polyethylene, MBS, ABS, ACR, nitrile rubber, and EVA; the pigment includes at least one of titanium dioxide, ultramarine, carbon black, silica, green toner, red toner, yellow toner, blue toner, and purple toner.

[0015] Second, the present invention provides a method for preparing the aforementioned high-quality plastic alloy pipe for natural gas and water supply and drainage, comprising the following steps:

[0016] Process route: inner tube extrusion (processing temperature 140℃-220℃) - cooling (20℃-36℃) - outer layer heating (120℃-150℃) - maleic acid liver graft copolymer compounded on the outer surface of the inner tube - metal pipe coated on the outside of the inner tube - three-layer film compounded on the surface of the metal pipe - heating (100-180℃) - outer plastic extrusion compounded on the three-layer film - cooling - the inner wall of the pipe is steam heated and cross-linked (that is, the pipe is placed on the rack, both ends are blocked, and 60℃-100℃ steam or hot water is input through the input hole, and the thermal cross-linking time is 1-4h) - cooling - testing - finished product.

[0017] The inner tube material is extruded to obtain the inner tube material, the intermediate material is heated and compounded on the outer surface of the inner tube, the metal tube is coated on the outer surface of the inner tube, and then the film is wrapped on the surface of the metal pipe; then, the outer layer material is extruded and compounded on the surface of the film, the inner wall is vacuum cross-linked and heated, and the tube is obtained after cooling.

[0018] In the above, the preparation method of the inner tube material is to weigh the inner tube material in proportion, stir it in a mixer for 3 to 15 minutes, the temperature does not exceed 40°C, and put the mixed inner tube material into an extruder for extrusion. The parameters of the extruder are: barrel temperature zone 1 130 to 140°C, zone 2 150 to 170°C, zone 3 170 to 180°C, zone 4 180 to 200°C, mold temperature 185 to 200°C, die temperature 190 to 235°C; extrusion speed 1 to 3 m / min.

[0019] In the above, the preparation method of the film is to use a three-layer extrusion die, 3 extruders, the inner film is maleic acid grafted polyethylene, the middle film is polyethylene, and the outer film is maleic acid grafted-ethylene-vinyl acetate copolymer. The processing temperature of the film is 140-190°C. After the composite film is extruded, the cooling coil is a three-layer film. In the above, if a commonly used hot melt adhesive is directly used, the adhesive strength between PVC and metal pipes will be insufficient; based on this, we use a three-layer film to overcome the above problems, specifically: the three layers of film are an outer film, a transition film, and an inner film, the outer film is bonded to the PVC alloy material, the inner film is bonded to the metal, and the middle film is between the inner and outer films in the above film. If only the traditional hot melt adhesive is used to obtain the film, its bonding effect will be very poor, that is, there is a poor bonding effect with the metal, or a poor bonding effect with the PVC alloy material, or a good bonding effect with the PVC alloy material, and a poor bonding effect with the metal. Based on this, we set up three layers of adhesive film to meet the purpose of bonding with PVC alloy material and metal steel strip at the same time. In the present invention, the three layers of adhesive film are wound on the surface of the inner pipe by winding, and the winding speed is synchronized with the pipe extrusion speed.

[0020] In the above, the preparation process of the outer tube is to weigh the outer layer material in proportion, put it into a high-speed mixer and stir it for 3 to 15 minutes at a temperature of 110°C, cool the mixed material to 35°C, bag it for standby use, and put the standby material into the equipment mold that meets the following conditions for extrusion molding. Outer tube process: extruder barrel temperature zone 1 175 ~ 225°C, zone 2 165 ~ 215°C, zone 3 165 ~ 180°C, zone 4 155 ~ 175°C, mold temperature 175 ~ 200°C, die temperature 175 ~ 215°C, extrusion speed 1 ~ 3 meters / min.

[0021] In the above, the process of cross-linking the inner tube is as follows: the steam temperature is 60-100°C and the heating time is 1-4h.

[0022] In addition, the present invention can also change the inner tube material to the same material as the outer layer according to the above process, but the processing technology needs to be adjusted in the same way as the outer process.

[0023] The formulas of the inner tube and the outer tube mentioned above may be consistent or inconsistent.

[0024] The beneficial effects achieved by the present invention are:

[0025] The composite pipe provided by the present invention not only solves the problem of poor flame retardancy of PE, PP-R composite pipes and all-plastic pipes, and achieves the effect of good flame retardancy, but also improves the pressure bearing performance by 50%-80% compared with the existing steel-plastic composite pipes PE and PP-R with the same wall thickness. At the same time, since adhesive bonding can be used at room temperature, the strength of the connection interface exceeds that of the pipe body, the pipe cost is lower than that of PE and PP-R metal composite pipes, the construction efficiency is improved by 3-5 times compared with traditional pipes, the interface anti-leakage performance is better, and the corrosion resistance problem and the short service life problem of metal pipes are solved, and good corrosion resistance and aging resistance are achieved, with good economic and social benefits.

[0026] The composite pipe provided by the present invention adopts the arrangement mode of inner pipe, metal pipe, adhesive film and outer pipe, which can improve the bonding strength between the metal pipe and the inner and outer pipes. At the same time, the arrangement of the inner and outer pipes can greatly improve the performance of the composite pipe.

[0027] The inner layer PVC-C provided by the present invention not only improves the strength and pressure bearing performance of the pipe through micro-crosslinking, but also improves the heat resistance and aging resistance. The addition of silicone powder and PMMA can make the water flow resistance of the inner wall of the pipe smaller. PMMA improves the composite performance with the film, and the strength is increased by 20-30% under the same conditions. The outer layer is modified by engineering plastics and micro-crosslinked, which not only has good flame retardant properties, but also has good mechanical properties and good composite properties. The present invention uses five-layer composite, and the pressure bearing performance of the polyolefin steel-plastic composite pipe of the prior art is improved by 50-80% with the same wall thickness, and the oxygen index is increased by more than 50%, which can reach more than 50%, and can be bonded and connected at room temperature, and the installation efficiency is increased by 2-5 times, and the Vicat softening point is increased by 25-35°C. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0029] Example 1

[0030] This embodiment provides a method for preparing high-quality plastic alloy pipes for natural gas and water supply and drainage, comprising the following steps:

[0031] (1) Weigh the inner tube material and the outer tube material by weight. Inner tube material: 100 parts of PVC-C resin, 20 parts of PMMA resin, 0.05 parts of diisopropylbenzene hydroperoxide, 8 parts of silicone powder, 5 parts of calcium zinc stabilizer, 0.5 parts of stearic acid, and 10 parts of chlorinated polyethylene; Outer tube material: 100 parts of ABS resin, 20 parts of PMMA resin, 0.05 parts of diisopropylbenzene hydroperoxide, 3 parts of titanate coupling agent, 5 parts of calcium zinc stabilizer, 1 part of stearic acid, 10 parts of chlorinated polyethylene, 0.3 parts of titanium dioxide, 10 parts of ammonium octamolybdate, and 10 parts of phosphogypsum.

[0032] (2) Pipe preparation: The processing technology of pipes is as follows:

[0033] Inner tube extrusion (processing temperature 140℃-220℃) - cooling (20℃-36℃) - outer layer heating (120℃-150℃) - maleic acid liver grafted copolymer on the outer surface of the inner tube - metal pipe coated on the outside of the inner tube - three layers of film composited on the surface of the metal pipe - heating (100-180℃) - outer layer plastic extrusion composite three layers of film - cooling - the inner wall of the pipe is steam heated and cross-linked (that is, the pipe is placed on the rack, both ends are blocked, and 60℃-100℃ steam or hot water is input through the input hole, and the thermal cross-linking time is 1-4h) - cooling - testing - finished product.

[0034] The inner tube material is extruded to obtain the inner tube material, the intermediate material is heated and compounded on the outer surface of the inner tube, the metal tube is coated on the outer surface of the inner tube, and then the film is wrapped on the surface of the metal pipe; then, the outer layer material is extruded and compounded on the surface of the film, the inner wall is vacuum cross-linked and heated, and the tube is obtained after cooling.

[0035] The preparation method of the inner tube material is as follows: weigh the inner tube material in proportion, stir it in a mixer for 3 to 15 minutes, the temperature does not exceed 40°C, and put the mixed inner tube material into an extruder for extrusion. The parameters of the extruder are: barrel temperature zone 1 130 to 140°C, zone 2 150 to 170°C, zone 3 170 to 180°C, zone 4 180 to 200°C, mold temperature 185 to 200°C, die temperature 190 to 235°C; extrusion speed 1 to 3 m / min.

[0036] The preparation method of the film is to use a three-layer extrusion die and three extruders, the inner film is maleic acid grafted polyethylene, the middle film is polyethylene, and the outer film is maleic acid grafted ethylene-vinyl acetate copolymer. The processing temperature of the film is 140-190°C, and after extruding the composite film, it is cooled and rolled into a three-layer film.

[0037] The preparation process of the outer tube is to weigh the outer layer material in proportion, put it into a high-speed mixer and stir it for 3 to 15 minutes at a temperature of 110°C, cool the mixed material to 35°C, bag it for standby use, and put the standby material into the equipment mold that meets the following conditions for extrusion molding. Outer tube process: extruder barrel temperature zone 1 175 ~ 225°C, zone 2 165 ~ 215°C, zone 3 165 ~ 180°C, zone 4 155 ~ 175°C, mold temperature 175 ~ 200°C, die temperature 175 ~ 215°C, extrusion speed 1 ~ 3 meters / min.

[0038] In the above, the process of cross-linking the inner tube is as follows: the steam temperature is 60-100°C and the heating time is 1-4h.

[0039] After testing: through five-layer composite, compared with the existing polyolefin steel-plastic composite pipe, with the same wall thickness, the pressure bearing performance is improved by 50-80%, the oxygen index is increased by more than 50%, and can reach more than 50%. It can be bonded at room temperature, the installation efficiency is increased by 2-5 times, and the Vicat softening point is increased by 25-35℃.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-quality plastic alloy pipe for natural gas and water supply and drainage, characterized in that: It includes an inner tube, an intermediate tube and an outer tube; The raw materials of the inner tube and the outer tube are independently selected from: Combination 1 or Combination 2: Combination 1: The raw material components are calculated by weight, including 50-100 parts of PVC-C resin, 5-25 parts of PMMA resin, 0.05-1.0 parts of cross-linking agent, 1-15 parts of silicone powder, 1-8 parts of stabilizer, 0.1-0.8 parts of lubricant, and 2-20 parts of modifier; Combination 2: The raw material components are calculated by weight, including 50-100 parts of ABS resin, 5-25 parts of PMMA resin, 0.05-1.0 parts of crosslinking agent, 1-5 parts of coupling agent, 1-8 parts of stabilizer, 0.1-1.5 parts of lubricant, 2-25 parts of modifier, 0.05-0.5 parts of pigment, 5-25 parts of ammonium octamolybdate, and 1-15 parts of phosphogypsum; The middle tube comprises a metal layer close to the inner tube and at least one film layer far away from the inner tube; each film layer comprises at least one of maleic acid grafted polyethylene, polyethylene, and maleic acid grafted-ethylene-vinyl acetate copolymer.

2. The high-quality plastic alloy pipe for natural gas and water supply and drainage according to claim 1 is characterized in that: Combination 1 includes at least one of features (1-1) to (1-4): (1-1) the crosslinking agent includes at least one of dicumyl peroxide, dicumyl hydroperoxide, and a silane crosslinking agent; (1-2) The stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, and a rare earth stabilizer; (1-3) The lubricant includes at least one of stearic acid, paraffin, polyethylene wax, and oxidized polyethylene wax; (1-4) The modifier includes at least one of chlorinated polyethylene, MBS, ABS, ACR, nitrile rubber, and EVA.

3. The high-quality plastic alloy pipe for natural gas and water supply and drainage according to claim 1 is characterized in that: Combination 2 includes at least one of features (2-1) to (2-6): (2-1) the crosslinking agent includes at least one of dicumyl peroxide, dicumyl hydroperoxide, and a silane crosslinking agent; (2-2) the coupling agent includes at least one of a titanate coupling agent, an aluminate coupling agent, an aluminum-titanium coupling agent, and a silane coupling agent; (2-3) The stabilizer includes at least one of a calcium zinc stabilizer, an organic tin stabilizer, and a rare earth stabilizer; (2-4) The lubricant includes at least one of stearic acid, paraffin, polyethylene wax, and oxidized polyethylene wax; (2-5) The modifier includes at least one of chlorinated polyethylene, MBS, ABS, ACR, nitrile rubber, and EVA; (2-6) The pigment includes at least one of titanium dioxide, ultramarine, carbon black, silica, green toner, red toner, yellow toner, blue toner, and violet toner.

4. A method for preparing high-quality plastic alloy pipes for natural gas and water supply and drainage as claimed in any one of claims 1 to 3, characterized in that: The steps include: The inner tube material is extruded to obtain the inner tube, the intermediate material is heated and compounded on the outer surface of the inner tube, the metal tube is coated on the outer surface of the inner tube, and then the film is wrapped on the surface of the metal tube; then, the outer tube material is extruded and compounded on the surface of the film, the inner wall is vacuum cross-linked and heated, and the tube is obtained after cooling.

5. The method for preparing high-quality plastic alloy pipes for natural gas and water supply and drainage according to claim 4, characterized in that: The preparation method of the inner tube is as follows: weigh the inner tube material according to proportion, stir it in a mixer for 3 to 15 minutes at a temperature not exceeding 40° C., and put the mixed inner tube material into an extruder for extrusion.

6. The method for preparing high-quality plastic alloy pipes for natural gas and water supply and drainage according to claim 5, characterized in that: The parameters of the extruder are: barrel temperature zone 1 130-140°C, zone 2 150-170°C, zone 3 170-180°C, zone 4 180-200°C, mold temperature 185-200°C, die temperature 190-235°C; extrusion speed 1-3 m / min.

7. The method for preparing high-quality plastic alloy pipes for natural gas and water supply and drainage according to claim 4, characterized in that: The preparation method of the adhesive film is to extrude the adhesive film by using three extruders to obtain a composite film; the processing temperature of the adhesive film is 140-190°C.

8. The method for preparing high-quality plastic alloy pipes for natural gas and water supply and drainage according to claim 4, characterized in that: The film has a three-layer structure, the inner film is maleic acid grafted polyethylene, the middle film is polyethylene, and the outer film is maleic acid grafted-ethylene-vinyl acetate copolymer.

9. The method for preparing high-quality plastic alloy pipes for natural gas and water supply and drainage according to claim 4, characterized in that: The preparation method of the outer tube is as follows: the temperature is 110°C, the mixed materials are cooled to 35°C, bagged for standby use, and extruded; the barrel temperature of the extruder is 175-225°C in zone 1, 165-215°C in zone 2, 165-180°C in zone 3, 155-175°C in zone 4, the mold temperature is 175-200°C, the die temperature is 175-215°C, and the extrusion speed is 1-3 m / min.