A steel wire skeleton PE composite pipe with a thin-walled stainless steel inner lining and its production process

Abstract

The present invention provides a steel wire framework PE composite pipe with a thin-walled stainless steel inner lining and its production process, belonging to the technical field of composite pipes. The method includes: (1) forming a steel pipe from a steel strip through a pipe forming machine; (2) winding a first steel wire with an adhesive coated on its surface around the outer part of the steel pipe; (3) winding a second steel wire around the outer part of the steel pipe wound with the first steel wire, and the second steel wire is a mesh cross steel wire; (4) placing the steel pipe wound with two layers of steel wires in a heated and glue-coated state so that the outer surface of the second steel wire is coated with a second adhesive; (5) wrapping the outer surface of the second steel wire of the steel pipe with a PE film in the state where the second adhesive is not cured to form a steel wire framework PE composite pipe with a thin-walled stainless steel inner lining. The composite pipe prepared by the present invention is corrosion-resistant, high-temperature-resistant, water-resistant, has a certain flame retardancy, and has high strength. At the same time, the adhesives between the multi-layer structures are firmly adhered and are not prone to detachment, and the peel strength is high.

Description

Technical Field

[0001] The present invention relates to the technical field of composite pipes, and particularly relates to a steel wire skeleton PE composite pipe with a thin-walled stainless steel pipe liner and its production process. Background Art

[0002] In the construction of industrial and agricultural production and urban infrastructure, the transportation of pressure media requires pipes with extremely high strength, such as plastic pipes or steel pipes. The former has the properties of corrosion resistance and heat preservation, but due to being made of plastic, its strength is relatively low; the latter has relatively high strength, but since it is made of steel, it is prone to corrosion and the cost is relatively high. In order to enhance the strength and performance of composite pipes, a form of composite pipe can also be adopted where a plastic pipe is coated outside a steel pipe, but such composite pipes often have problems such as poor adhesiveness between the steel pipe and the plastic pipe and easy detachment. Summary of the Invention

[0003] The object of the present invention is to provide a steel wire skeleton PE composite pipe with a thin-walled stainless steel pipe liner and its production process. This PE composite pipe is corrosion-resistant, high-temperature resistant, water-resistant, has a certain flame retardancy, and has high strength. At the same time, the adhesives between multiple layers are firmly adhered and not prone to detachment, and the peel strength is large.

[0004] The technical solution of the present invention is realized as follows:

[0005] The present invention provides a production process for a steel wire skeleton PE composite pipe with a thin-walled stainless steel pipe liner, including the following steps:

[0006] (1) Form a steel pipe by passing a steel strip through a pipe forming machine;

[0007] (2) Wind a first steel wire with a first adhesive coated on its surface around the outside of the steel pipe. Through the heating process, the first adhesive melts, so that the first steel wire is wound and adhered to the outside of the steel pipe. The first steel wire is a mesh cross steel wire;

[0008] (3) Wind a second steel wire around the outside of the steel pipe wound with the first steel wire at an angle to the first steel wire. The second steel wire is a mesh cross steel wire, wherein the cross structure of the second steel wire can be the same as or different from the cross structure of the first steel wire;

[0009] (4) Place the steel pipe wound with two layers of steel wires in a heated and glue-coated state, so that the outer surface of the second steel wire is coated with a second adhesive;

[0010] (5) While the second adhesive is not cured, wrap the outer surface of the second steel wire of the steel pipe with a PE film to form a steel pipe liner - two middle layers of steel wires - an outer PE steel wire skeleton PE composite pipe with a thin-walled stainless steel pipe liner;

[0011] Among them, the first adhesive and the second adhesive are the same or different.

[0012] As a further improvement of the present invention, the first adhesive and the second adhesive are the same and are a high-temperature resistant epoxy / organic silicone adhesive. The preparation method is as follows:

[0013] S1. Modification of silicone resin: Add silane coupling agent KH560 to polysiloxane silicone resin, heat and stir to mix evenly to obtain modified silicone resin.

[0014] S2. Modification of nano-silica: Add nano-silica to ethanol, add silane coupling agent, heat and stir to react, centrifuge, wash, and dry to obtain modified nano-silica.

[0015] S3. Chemical vapor deposition: Spread the modified nano-silica evenly in the center of a quartz porcelain boat, place it in a tube furnace, heat up under the protection of an inert gas, introduce n-hexane, keep the temperature for reaction, and cool to room temperature under the protection of an inert gas to obtain carbon nanotube / modified nano-silica.

[0016] S4. Preparation of flame retardant promoter: Add hexachlorocyclotriphosphazene and benzyl alcohol to an organic solvent, dropwise add triethylamine, stir at room temperature for reaction, add water to precipitate, filter, wash, and dry to obtain a flame retardant promoter.

[0017] S5. Preparation of high-temperature resistant epoxy / organic silicone adhesive: Mix the modified silicone resin, epoxy resin, and diluent evenly to obtain component A, mix the carbon nanotube / modified nano-silica, curing agent, and flame retardant promoter evenly to obtain component B. When in use, mix component A and component B evenly to obtain a high-temperature resistant epoxy / organic silicone adhesive.

[0018] As a further improvement of the present invention, in step S1, the mass ratio of the polysiloxane silicone resin to the silane coupling agent KH560 is 100:7-10, the temperature of the heating and stirring is 45-55 °C, and the time is 1-2 h.

[0019] As a further improvement of the present invention, in step S2, the mass ratio of the nano-silica to the silane coupling agent is 10:1-2, the silane coupling agent is selected from at least one of KH550, KH602, and KH792, the temperature of the heating and stirring reaction is 40-50 °C, and the time is 2-4 h.

[0020] As a further improvement of the present invention, in step S3, the temperature is raised to 650-670 °C, the ventilation rate of the n-hexane is 1-2 mL / min, and the time of the heat preservation reaction is 20-40 min.

[0021] As a further improvement of the present invention, in step S4, the molar ratio of hexachlorocyclotriphosphazene, benzyl alcohol, and triethylamine is 1:6 - 6.2:10 - 15, and the time for stirring reaction at room temperature is 3 - 5 h.

[0022] As a further improvement of the present invention, in step S5, the epoxy resin is epoxy resin E51 or E44, and the mass ratio of the modified silicone resin, epoxy resin, and diluent is 10:17 - 22:1 - 2; the diluent is diglycidyl ether; the curing agent is m - phenylenediamine or diaminodiphenylmethane; the mass ratio of carbon nanotube / modified nano - silicon oxide, curing agent, and flame - retardant promoter is 1 - 2:1.5 - 2.5:1.2 - 1.5.

[0023] As a further improvement of the present invention, the first adhesive is different from the second adhesive. One of the first adhesive or the second adhesive is a high - temperature - resistant epoxy / organic silicone adhesive, and the other is an epoxy resin adhesive E51.

[0024] As a further improvement of the present invention, the thickness of the steel pipe is 0.5 - 1.5 mm, the thickness of the first steel wire layer and the second steel wire layer is 0.1 - 1.0 mm, the thickness of the PE film is 1 - 2 mm, and the heating temperature is 150 - 160 °C.

[0025] The present invention further protects an inner - lined thin - wall stainless - steel pipe steel - wire - skeleton PE composite pipe prepared by the above - mentioned production process.

[0026] The present invention has the following beneficial effects:

[0027] The inner - lined thin - wall stainless - steel pipe steel - wire - skeleton PE composite pipe prepared by the present invention not only effectively overcomes the problems of low strength of a single PE pipe, corrosion of a single steel pipe, and high cost, or the problems of poor adhesiveness between the steel pipe and the plastic pipe in a composite pipe formed by setting a steel wire mesh or a steel pipe inside or outside a PE pipe, and easy detachment. The composite pipe prepared by the present invention is corrosion - resistant, high - temperature - resistant, water - resistant, has a certain flame - retardancy, and has high strength. At the same time, the adhesives between the multi - layer structures are firmly adhered, are not easy to detach, have a large peel strength, and the formed composite pipe has good comprehensive performance.

[0028] The present invention prepares a high - temperature - resistant epoxy / organic silicone adhesive. By modifying the polysiloxane silicone resin with the silane coupling agent KH560, the silane coupling agent KH560 can significantly improve the high - temperature resistance. The silane coupling agent KH560 acts as a transition phase and plays a bridging role at the interface of two substances, epoxy resin and silicone resin, significantly improving the compatibility between the epoxy resin and the silicone resin, reducing the internal stress of the system, and thus enhancing the high - temperature resistance.

[0029] After the surface of nano-silica is modified with a silane coupling agent, carbon nanotubes are deposited on the surface. On the one hand, the branched chains of the modified silane coupling agent can facilitate entanglement with the molecular weight of epoxy resin, improving the dispersibility of nano-particles. At the same time, after the carbon nanotubes are deposited, the surface forms a wrinkled shape, reducing agglomeration in the resin matrix and achieving uniform dispersion, which can greatly improve its toughness and strength. Also, since the particles are uniformly dispersed in the resin matrix, when the matrix is impacted, the crazes generated between the particles and the matrix can absorb a large amount of impact energy and prevent the spread of crazes. At the same time, the matrix between the particles also undergoes plastic deformation to absorb impact energy, thus achieving the toughening effect. In addition, the amino groups of the nano-particles modified with a silane coupling agent containing amino groups can also react with epoxy groups, playing a role as a part of the curing agent.

[0030] The flame retardant promoter prepared by the present invention is based on hexachlorocyclotriphosphazene and reacts with benzyl alcohol to form an organic phosphine structure flame retardant promoter. It not only has the characteristics of N-P flame retardants, but also has good compatibility with the resin system, high catalytic activity, stable storage, low hygroscopicity, excellent heat resistance, high decomposition temperature, and can co-cure with amine curing agents, greatly reducing the dosage of the curing agent.

[0031] In addition, the epoxy resin and silicone resin matrix of the present invention are used as the main materials, toughened with nano-particles, and have good mechanical strength and corrosion resistance after curing, and the high temperature resistance and flame retardant properties are also significantly improved. Specific embodiments

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Polysiloxane silicone resin SAR-9, a light yellow uniform liquid, with a solid content of 51% and a viscosity of 30 - 35 MPa·s.

[0034] The particle size range of nano-silica is 150 ± 50 nm.

[0035] Preparation Example 1 Preparation of high temperature resistant epoxy / silicone adhesive

[0036] Specifically, it includes the following steps:

[0037] S1. Modification of silicone resin: Add 7 g of silane coupling agent KH560 to 100 g of polysiloxane silicone resin SAR-9, heat to 45 °C, and stir and react for 1 h to obtain a modified silicone resin;

[0038] S2. Modification of nano-silica: Add 10 g of nano-silica to 200 mL of ethanol, add 1 g of silane coupling agent KH550, heat to 40 °C, stir and react for 2 h, centrifuge, wash, and dry to obtain modified nano-silica;

[0039] S3. Chemical vapor deposition: Evenly spread 10 g of modified nano-silica in the center of a quartz porcelain boat, place it in a tube furnace, heat to 650 °C under nitrogen protection, introduce n-hexane, the gas flow rate of n-hexane is 1 mL / min, keep the temperature and react for 20 min, and cool to room temperature under nitrogen protection to obtain carbon nanotube / modified nano-silica;

[0040] S4. Preparation of flame retardant promoter: Add 0.1 mol of hexachlorocyclotriphosphazene and 0.6 mol of benzyl alcohol to 200 mL of acetonitrile, dropwise add 1 mol of triethylamine, stir and react at room temperature for 3 h, add an equal volume of water to precipitate, filter, wash, and dry to obtain the flame retardant promoter;

[0041] S5. Preparation of high-temperature resistant epoxy / organosilicon adhesive: Stir and mix 10 g of modified silicone resin, 17 g of epoxy resin E51 and 1 g of diglycidyl ether for 15 min to obtain component A, stir and mix 1 g of carbon nanotube / modified nano-silica, 1.5 g of m-xylenediamine and 1.2 g of flame retardant promoter for 15 min to obtain component B. When in use, stir and mix component A and component B for 15 min and cure for 1 h to obtain the high-temperature resistant epoxy / organosilicon adhesive.

[0042] Preparation Example 2 Preparation of high-temperature resistant epoxy / organosilicon adhesive

[0043] Specifically, it includes the following steps:

[0044] S1. Modification of silicone resin: Add 10 g of silane coupling agent KH560 to 100 g of polysiloxane silicone resin SAR-9, heat to 55 °C, stir and react for 2 h to obtain modified silicone resin;

[0045] S2. Modification of nano-silica: Add 10 g of nano-silica to 200 mL of ethanol, add 2 g of silane coupling agent KH602, heat to 50 °C, stir and react for 4 h, centrifuge, wash, and dry to obtain modified nano-silica;

[0046] S3. Chemical vapor deposition: Evenly spread 10 g of modified nano-silica in the center of a quartz porcelain boat, place it in a tube furnace, heat to 670 °C under nitrogen protection, introduce n-hexane, the gas flow rate of n-hexane is 2 mL / min, keep the temperature and react for 40 min, and cool to room temperature under nitrogen protection to obtain carbon nanotube / modified nano-silica;

[0047] S4. Preparation of flame retardant promoter: Add 0.1 mol of hexachlorocyclotriphosphazene and 0.62 mol of benzyl alcohol into 200 mL of acetonitrile, dropwise add 1.5 mol of triethylamine, stir and react at room temperature for 5 h, add an equal volume of water for precipitation, filter, wash, and dry to obtain the flame retardant promoter;

[0048] S5. Preparation of high-temperature resistant epoxy / silicone adhesive: Stir and mix 10 g of modified silicone resin, 22 g of epoxy resin E51 and 2 g of diglycidyl ether for 15 min to obtain component A. Stir and mix 2 g of carbon nanotube / modified nano-silica, 2.5 g of diaminodiphenylmethane and 1.5 g of flame retardant promoter for 15 min to obtain component B. When in use, stir and mix component A and component B for 15 min and cure for 1 h to obtain the high-temperature resistant epoxy / silicone adhesive.

[0049] Preparation Example 3 Preparation of high-temperature resistant epoxy / silicone adhesive

[0050] Specifically, it includes the following steps:

[0051] S1. Modification of silicone resin: Add 8.5 g of silane coupling agent KH560 to 100 g of polysiloxane silicone resin SAR-9, heat to 50 °C, and stir and react for 1.5 h to obtain the modified silicone resin;

[0052] S2. Modification of nano-silica: Add 10 g of nano-silica into 200 mL of ethanol, add 1.5 g of silane coupling agent KH792, heat to 45 °C, stir and react for 3 h, centrifuge, wash, and dry to obtain the modified nano-silica;

[0053] S3. Chemical vapor deposition: Spread 10 g of modified nano-silica evenly in the center of a quartz porcelain boat, place it in a tube furnace, heat to 660 °C under nitrogen protection, introduce n-hexane, the ventilation rate of the n-hexane is 1.5 mL / min, keep the temperature and react for 30 min, and cool to room temperature under nitrogen protection to obtain carbon nanotube / modified nano-silica;

[0054] S4. Preparation of flame retardant promoter: Add 0.1 mol of hexachlorocyclotriphosphazene and 0.61 mol of benzyl alcohol into 200 mL of acetonitrile, dropwise add 1.2 mol of triethylamine, stir and react at room temperature for 4 h, add an equal volume of water for precipitation, filter, wash, and dry to obtain the flame retardant promoter;

[0055] S5. Preparation of high-temperature resistant epoxy / organosilicon adhesive: 10 g of modified silicone resin, 20 g of epoxy resin E51 and 1.2 g of diglycidyl ether were stirred and mixed for 15 min to obtain component A. 1.5 g of carbon nanotube / modified nano-silica, 2 g of m-xylenediamine and 1.35 g of flame retardant promoter were stirred and mixed for 15 min to obtain component B. When in use, component A and component B were stirred and mixed for 15 min and then cured for 1 h to obtain the high-temperature resistant epoxy / organosilicon adhesive.

[0056] Comparative Preparation Example 1

[0057] Compared with Preparation Example 3, the difference lies in that step S1 was not carried out.

[0058] Specifically as follows:

[0059] S1. Modification of nano-silica: 10 g of nano-silica was added to 200 mL of ethanol, 1.5 g of silane coupling agent KH792 was added, heated to 45 °C, stirred and reacted for 3 h, centrifuged, washed and dried to obtain modified nano-silica;

[0060] S2. Chemical vapor deposition: 10 g of modified nano-silica was evenly spread out in the center of a quartz porcelain boat, placed in a tube furnace, heated to 660 °C under nitrogen protection, n-hexane was introduced, the gas flow rate of n-hexane was 1.5 mL / min, kept warm and reacted for 30 min, and cooled to room temperature under nitrogen protection to obtain carbon nanotube / modified nano-silica;

[0061] S3. Preparation of flame retardant promoter: 0.1 mol of hexachlorocyclotriphosphazene and 0.61 mol of benzyl alcohol were added to 200 mL of acetonitrile, 1.2 mol of triethylamine was added dropwise, stirred and reacted at room temperature for 4 h, precipitated with an equal volume of water, filtered, washed and dried to obtain the flame retardant promoter;

[0062] S4. Preparation of high-temperature resistant epoxy / organosilicon adhesive: 10 g of polysiloxane silicone resin SAR-9, 20 g of epoxy resin E51 and 1.2 g of diglycidyl ether were stirred and mixed for 15 min to obtain component A. 1.5 g of carbon nanotube / modified nano-silica, 2 g of m-xylenediamine and 1.35 g of flame retardant promoter were stirred and mixed for 15 min to obtain component B. When in use, component A and component B were stirred and mixed for 15 min and then cured for 1 h to obtain the high-temperature resistant epoxy / organosilicon adhesive.

[0063] Comparative Preparation Example 2

[0064] Compared with Preparation Example 3, the difference lies in that step S2 was not carried out.

[0065] Specifically as follows:

[0066] S1. Modification of silicone resin: 8.5 g of silane coupling agent KH560 was added to 100 g of polysiloxane silicone resin SAR-9, heated to 50 °C, and stirred and reacted for 1.5 h to obtain modified silicone resin;

[0067] S2. Chemical vapor deposition: 10 g of nano-silica was evenly spread out in the center of a quartz porcelain boat, placed in a tube furnace, heated to 660 °C under nitrogen protection, and n-hexane was introduced. The gas flow rate of n-hexane was 1.5 mL / min, and the reaction was carried out at a constant temperature for 30 min, and then cooled to room temperature under nitrogen protection to obtain carbon nanotube / nano-silica;

[0068] S3. Preparation of flame retardant promoter: 0.1 mol of hexachlorocyclotriphosphazene and 0.61 mol of benzyl alcohol were added to 200 mL of acetonitrile, 1.2 mol of triethylamine was added dropwise, stirred and reacted at room temperature for 4 h, precipitated with an equal volume of water, filtered, washed, and dried to obtain a flame retardant promoter;

[0069] S4. Preparation of high-temperature resistant epoxy / silicone adhesive: 10 g of modified silicone resin, 20 g of epoxy resin E51 and 1.2 g of diglycidyl ether were stirred and mixed for 15 min to obtain component A. 1.5 g of carbon nanotube / nano-silica, 2 g of m-xylenediamine and 1.35 g of flame retardant promoter were stirred and mixed for 15 min to obtain component B. When in use, component A and component B were stirred and mixed for 15 min and cured for 1 h to obtain a high-temperature resistant epoxy / silicone adhesive.

[0070] Comparative Preparation Example 3

[0071] Compared with Preparation Example 3, the difference is that step S3 was not carried out.

[0072] Specifically as follows:

[0073] S1. Modification of silicone resin: 8.5 g of silane coupling agent KH560 was added to 100 g of polysiloxane silicone resin SAR-9, heated to 50 °C, and stirred and reacted for 1.5 h to obtain modified silicone resin;

[0074] S2. Modification of nano-silica: 10 g of nano-silica was added to 200 mL of ethanol, 1.5 g of silane coupling agent KH792 was added, heated to 45 °C, stirred and reacted for 3 h, centrifuged, washed, and dried to obtain modified nano-silica;

[0075] S3. Preparation of flame retardant promoter: 0.1 mol of hexachlorocyclotriphosphazene and 0.61 mol of benzyl alcohol were added to 200 mL of acetonitrile, 1.2 mol of triethylamine was added dropwise, stirred and reacted at room temperature for 4 h, precipitated with an equal volume of water, filtered, washed, and dried to obtain a flame retardant promoter;

[0076] S4. Preparation of high-temperature resistant epoxy / organosilicon adhesive: 10 g of modified silicone resin, 20 g of epoxy resin E51 and 1.2 g of diglycidyl ether were stirred and mixed for 15 min to obtain component A. 1.5 g of modified nano-silica, 2 g of m-xylenediamine and 1.35 g of flame retardant promoter were stirred and mixed for 15 min to obtain component B. When in use, component A and component B were stirred and mixed for 15 min and cured for 1 h to obtain the high-temperature resistant epoxy / organosilicon adhesive.

[0077] Comparative Preparation Example 4

[0078] Compared with Preparation Example 3, the difference lies in that the flame retardant promoter is replaced by triphenylphosphine.

[0079] Specifically as follows:

[0080] S1. Modification of silicone resin: 8.5 g of silane coupling agent KH560 was added to 100 g of polysiloxane silicone resin SAR-9, heated to 50 °C and stirred for reaction for 1.5 h to obtain the modified silicone resin;

[0081] S2. Modification of nano-silica: 10 g of nano-silica was added to 200 mL of ethanol, 1.5 g of silane coupling agent KH792 was added, heated to 45 °C and stirred for reaction for 3 h, centrifuged, washed and dried to obtain the modified nano-silica;

[0082] S3. Chemical vapor deposition: 10 g of modified nano-silica was evenly spread out in the center of a quartz porcelain boat, placed in a tube furnace, heated to 660 °C under nitrogen protection, n-hexane was introduced, the gas flow rate of the n-hexane was 1.5 mL / min, kept warm and reacted for 30 min, and cooled to room temperature under nitrogen protection to obtain carbon nanotube / modified nano-silica;

[0083] S4. Preparation of high-temperature resistant epoxy / organosilicon adhesive: 10 g of modified silicone resin, 20 g of epoxy resin E51 and 1.2 g of diglycidyl ether were stirred and mixed for 15 min to obtain component A. 1.5 g of carbon nanotube / modified nano-silica, 2 g of m-xylenediamine and 1.35 g of triphenylphosphine were stirred and mixed for 15 min to obtain component B. When in use, component A and component B were stirred and mixed for 15 min and cured for 1 h to obtain the high-temperature resistant epoxy / organosilicon adhesive.

[0084] Comparative Preparation Example 5

[0085] Compared with Preparation Example 3, the difference lies in that carbon nanotube / modified nano-silica was not added.

[0086] Specifically as follows:

[0087] S1. Modification of silicone resin: 8.5 g of silane coupling agent KH560 was added to 100 g of polysiloxane silicone resin SAR-9, heated to 50 °C, and stirred and reacted for 1.5 h to obtain the modified silicone resin;

[0088] S2. Preparation of flame retardant promoter: 0.1 mol of hexachlorocyclotriphosphazene and 0.61 mol of benzyl alcohol were added to 200 mL of acetonitrile, 1.2 mol of triethylamine was added dropwise, stirred and reacted at room temperature for 4 h, precipitated with an equal volume of water, filtered, washed, and dried to obtain the flame retardant promoter;

[0089] S3. Preparation of high-temperature resistant epoxy / silicone adhesive: 10 g of modified silicone resin, 20 g of epoxy resin E51 and 1.2 g of diglycidyl ether were stirred and mixed for 15 min to obtain component A, 3.5 g of m-xylenediamine and 1.35 g of flame retardant promoter were stirred and mixed for 15 min to obtain component B. When in use, component A and component B were stirred and mixed for 15 min and cured for 1 h to obtain the high-temperature resistant epoxy / silicone adhesive.

[0090] Test Example 1

[0091] The high-temperature resistant epoxy / silicone adhesives prepared in Preparation Examples 1-3 and Comparative Examples 1-5 were subjected to performance tests.

[0092] The normal temperature shear strength was carried out according to GB / T 7124-2008, and the high temperature shear strength was carried out according to GJB / 444-1988. The test piece material was LY12CZ aluminum alloy, with a specification of 60 mm × 20 mm × 3 mm, and the bonding area: 20 mm × 15 mm.

[0093] The limiting oxygen index (LOI) was tested according to the standard of GB / T2406.2-2009 after the sample was made into a shape of 100 mm × 10 mm × 4 mm.

[0094] The results are shown in Table 1.

[0095]

[0096] As can be seen from the above table, the high-temperature resistant epoxy / silicone adhesives prepared in Preparation Examples 1-3 of the present invention have good mechanical properties, high temperature resistance and flame retardant properties. Example 1

[0097] This example provides a production process for a steel wire skeleton PE composite pipe with a thin-walled stainless steel pipe lining, including the following steps:

[0098] S1. The steel strip was formed into a steel pipe through a pipe forming machine with a thickness of 1 mm;

[0099] S2. Wind the first steel wire with the first adhesive coated on its surface around the outside of the steel pipe. By heating to 150 °C, the first adhesive melts, causing the first steel wire to wind and adhere to the outside of the steel pipe. The first steel wire is a mesh cross wire;

[0100] S3. Wind the second steel wire around the outside of the steel pipe wound with the first steel wire at an angle to the first steel wire. The second steel wire is a mesh cross wire. Among them, the cross structure of the second steel wire can be the same as or different from the cross structure of the first steel wire;

[0101] S4. Heat the steel pipe wound with two layers of steel wires to 150 °C. In the state of being coated with glue, the outer surface of the second steel wire is coated with the second adhesive;

[0102] S5. In the state where the second adhesive is not cured, wrap the outer surface of the second steel wire of the steel pipe with a PE film to form a lined thin-walled stainless steel pipe wire skeleton PE composite pipe with a steel pipe inner lining - two middle layers of steel wires - an outer PE;

[0103] The thickness of the first steel wire layer and the second steel wire layer is 0.5 mm; the thickness of the PE film is 2 mm;

[0104] Among them, the first adhesive and the second adhesive are the same, and are the high-temperature resistant epoxy / organic silicone adhesive prepared in Preparation Example 1. Example 2

[0105] This example provides a production process for a lined thin-walled stainless steel pipe wire skeleton PE composite pipe, including the following steps:

[0106] S1. Form a steel pipe from a steel strip through a pipe forming machine, with a thickness of 1 mm;

[0107] S2. Wind the first steel wire with the first adhesive coated on its surface around the outside of the steel pipe. By heating to 160 °C, the first adhesive melts, causing the first steel wire to wind and adhere to the outside of the steel pipe. The first steel wire is a mesh cross wire;

[0108] S3. Wind the second steel wire around the outside of the steel pipe wound with the first steel wire at an angle to the first steel wire. The second steel wire is a mesh cross wire. Among them, the cross structure of the second steel wire can be the same as or different from the cross structure of the first steel wire;

[0109] S4. Heat the steel pipe wound with two layers of steel wires to 160 °C, causing the outer surface of the second steel wire to be coated with the second adhesive;

[0110] S5. In the state where the second adhesive is not cured, wrap the outer surface of the second steel wire of the steel pipe with a PE film to form a lined thin-walled stainless steel pipe wire skeleton PE composite pipe with a steel pipe inner lining - two middle layers of steel wires - an outer PE;

[0111] The thickness of the first steel wire layer and the second steel wire layer is 0.5 mm; the thickness of the PE film is 2 mm;

[0112] Among them, the first adhesive is the high-temperature resistant epoxy / organic silicone adhesive prepared in Preparation Example 2, and the second adhesive is epoxy resin E51. Example 3

[0113] This example provides a production process for a steel wire skeleton PE composite pipe with a thin-walled stainless steel pipe liner, including the following steps:

[0114] S1. Pass the steel strip through a pipe forming machine to form a steel pipe with a thickness of 1 mm;

[0115] S2. Wind the first steel wire with the first adhesive coated on the outer surface around the steel pipe. By heating to 155 °C, the first adhesive melts, so that the first steel wire is wound and adhered to the outer surface of the steel pipe. The first steel wire is a mesh cross wire;

[0116] S3. Wind the second steel wire around the steel pipe wound with the first steel wire at an angle to the first steel wire. The second steel wire is a mesh cross wire. Among them, the cross structure of the second steel wire can be the same as or different from the cross structure of the first steel wire;

[0117] S4. Heat the steel pipe wound with two layers of steel wire to 155 °C, so that the outer surface of the second steel wire is coated with the second adhesive;

[0118] S5. Under the state where the second adhesive is not cured, wrap the outer surface of the second steel wire of the steel pipe with a PE film to form a steel pipe liner - two middle layers of steel wire - outer PE steel wire skeleton PE composite pipe with a thin-walled stainless steel pipe liner;

[0119] The thickness of the first steel wire layer and the second steel wire layer is 0.5 mm; the thickness of the PE film is 2 mm;

[0120] Among them, the first adhesive and the second adhesive are the high-temperature resistant epoxy / organic silicone adhesives prepared in Preparation Example 3.

[0121] Comparative Examples 1 - 5

[0122] Compared with Example 3, the difference is that the high-temperature resistant epoxy / organic silicone adhesives are respectively prepared from Comparative Preparation Examples 1 - 5.

[0123] Comparative Example 6

[0124] Compared with Example 3, the difference is that the second steel wire layer is not provided.

[0125] Comparative Example 7

[0126] Compared with Example 3, the difference lies in that the first steel wire layer and the second steel wire layer are not provided, and the steel pipe layer and the PE layer are bonded with a high-temperature-resistant epoxy / organic silicone adhesive.

[0127] Test Example 1

[0128] After curing the thin-walled stainless steel pipe wire-frame PE composite pipes prepared in Examples 1-3 and Comparative Examples 1-7 at room temperature for 72 h, the tensile strength and shear strength at 25 °C and 150 °C were measured respectively, and the detection was carried out according to the method of GB / T 228-2010. The results are shown in Table 2.

[0129]

[0130] As can be seen from the above table, the thin-walled stainless steel pipe wire-frame PE composite pipes prepared in Examples 1-3 of the present invention have relatively high strength and good high-temperature resistance.

[0131] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A production process of a steel wire skeleton PE composite pipe with a thin-walled stainless steel inner liner, characterized in that, It includes the following steps: (1) Form a steel pipe by passing a steel strip through a pipe forming machine; (2) Wind a first steel wire with a first adhesive coated on its surface around the outer surface of the steel pipe. Through a heating process, the first adhesive melts, so that the first steel wire is wound and adhered to the outer surface of the steel pipe. The first steel wire is a mesh cross steel wire; (3) Wind a second steel wire around the outer surface of the steel pipe wound with the first steel wire at an angle to the first steel wire. The second steel wire is a mesh cross steel wire, wherein the cross structure of the second steel wire is the same as or different from that of the first steel wire; (4) Place the steel pipe wound with two layers of steel wires in a heated and glue-coated state, so that the outer surface of the second steel wire is coated with a second adhesive; (5) Wrap the outer surface of the second steel wire of the steel pipe with a PE film in the state where the second adhesive is not cured, to form a lined thin-walled stainless steel pipe wire skeleton PE composite pipe with a steel pipe liner - two middle layers of steel wires - an external PE; Wherein, the first adhesive and the second adhesive are the same, and are high-temperature resistant epoxy / organic silicone adhesives. The preparation method is as follows: S1. Modification of silicone resin: Add silane coupling agent KH560 to polysiloxane silicone resin, heat and stir to mix evenly to obtain modified silicone resin; S2. Modification of nano-silica: Add nano-silica to ethanol, add silane coupling agent, heat and stir to react, centrifuge, wash, and dry to obtain modified nano-silica; S3. Chemical vapor deposition: Evenly spread the modified nano-silica in the center of a quartz porcelain boat, place it in a tube furnace, heat up under the protection of an inert gas, introduce n-hexane, keep the temperature for reaction, and cool to room temperature under the protection of an inert gas to obtain carbon nanotube / modified nano-silica; S4. Preparation of flame retardant promoter: Add hexachlorocyclotriphosphazene and benzyl alcohol to an organic solvent, dropwise add triethylamine, stir and react at room temperature, add water to precipitate, filter, wash, and dry to obtain a flame retardant promoter; S5. Preparation of high-temperature resistant epoxy / organic silicone adhesive: Mix the modified silicone resin, epoxy resin and diluent evenly to obtain component A, mix the carbon nanotube / modified nano-silica, curing agent and flame retardant promoter evenly to obtain component B, and mix component A and component B evenly during use to obtain a high-temperature resistant epoxy / organic silicone adhesive.

2. The production process according to claim 1, characterized in that, In step S1, the mass ratio of the polysiloxane silicone resin to the silane coupling agent KH560 is 100:7 - 10, the temperature of the heating and stirring is 45 - 55 °C, and the time is 1 - 2 h.

3. The production process according to claim 1, characterized in that, In step S2, the mass ratio of the nano-silica to the silane coupling agent is 10:1 - 2, the silane coupling agent is selected from at least one of KH550, KH602, and KH792, the temperature of the heating and stirring reaction is 40 - 50 °C, and the time is 2 - 4 h.

4. The production process according to claim 1, characterized in that, In step S3, the temperature is raised to 650 - 670 °C, the ventilation rate of the n-hexane is 1 - 2 mL / min, and the time of the heat preservation reaction is 20 - 40 min.

5. The production process according to claim 1, characterized in that, In step S4, the molar ratio of the hexachlorocyclotriphosphazene, benzyl alcohol, and triethylamine is 1:6 - 6.2:10 - 15, and the time of the stirring reaction at room temperature is 3 - 5 h.

6. The production process according to claim 1, characterized in that, The epoxy resin described in step S5 is epoxy resin E51 or E44, and the mass ratio of the modified silicone resin, epoxy resin and diluent is 10:17 - 22:1 - 2; the diluent is diglycidyl ether; the curing agent is m-xylenediamine or diaminodiphenylmethane; the mass ratio of the carbon nanotube / modified nano-silica, curing agent and flame retardant promoter is 1 - 2:1.5 - 2.5:1.2 - 1.

5.

7. The production process according to claim 1, characterized in that, The thickness of the steel pipe is 0.5 - 1.5 mm, the thicknesses of the first steel wire layer and the second steel wire layer are 0.1 - 1.0 mm, the thickness of the PE film is 1 - 2 mm, and the heating temperature is 150 - 160 °C.

8. A steel wire framework PE composite pipe with a thin-walled stainless steel inner lining prepared by the production process according to any one of claims 1 - 7.

Images