High-barrier flexible composite pipeline and preparation method thereof

Abstract

The invention provides a high-barrier flexible composite pipeline. The high-barrier flexible composite pipeline comprises 1) an inner layer; 2) an elastomer adhesive layer; the barrier layer is formed on the surface of the elastomer adhesive layer and is a metal layer or a non-metal layer with the thickness not less than 0.04 mm; 4) a reinforcing layer formed by winding a fiber band formed by fibers impregnated with an elastomer adhesive on the surface of the barrier layer at an angle of 45-75 degrees to the center of the pipe; 5) an outer layer formed from a thermoplastic resin or an elastomer wherein the elastomer adhesive comprises: a) 0-20 parts by weight of polypropylene; b) 50-70 parts by weight of a polyolefin elastomer; c) 0-30 parts by weight of polyethylene; d) 0.5-5 parts by weight of a polar monomer; e) 0.2 to 1.5 parts by weight of an initiator; and f) 0-5 parts by weight of an auxiliary agent. According to the high-barrier flexible composite pipeline, coiled transportation of the pipeline is achieved, and the risk of gas leakage is reduced.

Description

Technical Field

[0001] The present invention relates to the field of large-diameter pipelines, and particularly to a large-diameter high-barrier flexible conveying pipeline and a preparation method thereof. Background Art

[0002] The high-barrier flexible composite pipeline is a composite pipeline formed by adding a high-barrier function on the basis of the traditional flexible composite pipeline, and is used to block or reduce the exchange between the conveyed medium and the external environment. In the flexible pipeline, the high-barrier layer is generally arranged between the lining material and the reinforcing material, playing a role in improving the corrosion resistance, heat resistance and heat preservation performance of the pipeline. The high-barrier flexible composite pipeline has the advantages of light weight, corrosion resistance, high temperature resistance, sound insulation, heat preservation, etc., is suitable for occasions such as chemical industry, petrochemical industry, energy, municipal water supply, etc., is widely used for conveying various media such as liquids, gases, steam, etc., and plays an active role in environmental protection and resource conservation.

[0003] CN201507728U discloses a continuous fiber-reinforced thermoplastic composite pipeline with at least three-layer structure, and each layer structure uses a thermoplastic resin as the matrix. The reinforcing material is continuous fibers or their fabrics with different contents, and the continuous fibers or their fabrics are laid in a longitudinal manner, a winding manner and a weaving manner. This composite pipeline can improve and enhance the impact resistance, aging resistance, temperature resistance, and has more excellent mechanical properties. However, it can be coiled and transported when the inner diameter is 200 mm, but it is difficult to achieve the coiling of composite pipelines with a larger diameter.

[0004] CN213479408U discloses a high-barrier flexible composite pipe including a lining layer, a reinforcing layer and an outer pipe layer. Among them, a gas permeation resistance membrane is arranged between the outer pipe layer and the reinforcing layer and / or between the reinforcing layer and the lining layer. The gas permeation resistance membrane is a metal sheet layer with a thickness not less than 0.04 mm, and the metal sheet layer is an aluminum foil or a stainless steel thin sheet, or the gas permeation resistance membrane is a non-metal sheet layer, and the non-metal sheet layer is composed of at least one isolation layer made of nylon, PVDF, EVOH or POK plastic and protective layers made of polyethylene respectively located on the upper and lower sides of the isolation layer. This high-barrier flexible composite pipe has high pressure-bearing structural strength, good coiling flexibility, good gas impermeability and a long service life.

[0005] CN211624464U discloses a large-diameter flexible composite pipe including an inner pipe, a warp belt, a reinforcing layer and an outer pipe. Among them, the warp belt is arranged on the outer surface of the inner pipe parallel to the axis of the inner pipe, the reinforcing layer is wound on the warp belt, and the outer pipe is wrapped on the reinforcing layer. A warp belt layer is added between the inner pipe and the reinforcing layer, thereby improving the pressure resistance of the composite pipe, having high tensile resistance, oil resistance, corrosion resistance, and a long service life. However, it is difficult to coil.

[0006] Therefore, there is an urgent need for a large-diameter high-barrier flexible composite pipe that can be coiled. Summary of the Invention

[0007] Aiming at the problems existing in the prior art, the present invention aims to provide a high-barrier flexible composite pipe and its preparation method. By optimizing the inner and outer layer materials of pipes with different diameters, the pipe barrier performance is improved while enhancing the flexibility of the pipe, realizing the coiled transportation of the pipe, rapid laying without joints over long distances, and at the same time adding a gas barrier layer to reduce the risk of gas leakage.

[0008] According to the first aspect of the present invention, there is provided a high-barrier flexible composite pipe, which comprises:

[0009] (1) An inner layer formed of a thermoplastic resin or an elastomer;

[0010] (2) An elastomeric adhesive layer formed on the outer wall of the inner layer;

[0011] (3) A barrier layer, which is a metal layer or a non-metal layer with a thickness of not less than 0.04 mm, and is formed on the surface of the elastomeric adhesive layer;

[0012] (4) A reinforcing layer, which is formed by winding a fiber tape impregnated with an elastomeric adhesive on the surface of the barrier layer at an angle of 45 to 75° with the pipe center, and

[0013] (5) An outer layer bonded to the surface of the reinforcing layer, which is formed of a thermoplastic resin or an elastomer;

[0014] Wherein, the elastomeric adhesives in the elastomeric adhesive layer and the reinforcing layer comprise the following components:

[0015] (a) 0 to 20 parts by weight, preferably 5 to 15 parts by weight of polypropylene;

[0016] (b) 50 to 70 parts by weight, preferably 55 to 70 parts by weight of polyolefin elastomer;

[0017] (c) 0 to 40 parts by weight, preferably 5 to 40 parts by weight of polyethylene;

[0018] (d) 0.5 to 5 parts by weight of a polar monomer;

[0019] (e) 0.2 to 1.5 parts by weight of an initiator; and

[0020] (f) 0 to 5 parts by weight of an auxiliary agent.

[0021] Preferably, the inner diameter of the high-barrier flexible composite pipe is more than 20 mm, and more preferably more than 100 mm.

[0022] Preferably, the inner diameter of the high-barrier flexible composite pipe is below 800 mm.

[0023] Preferably, the gas transmission rate of the high-barrier flexible composite pipe is below 0.035% / h, more preferably below 0.030% / h.

[0024] The high-barrier flexible composite pipe of the present invention has particularly good flexibility and a small coiling radius, and is particularly suitable for making a large-size inner diameter.

[0025] Preferably, the melt index of the polypropylene measured according to ISO1133 under a load of 2.16 kg and at a temperature of 230 °C is 0.5 g to 5 g / 10 min, preferably 0.5 to 4.0 g / 10 min.

[0026] Preferably, the polypropylene is a propylene homopolymer or a propylene copolymer.

[0027] Preferably, the propylene copolymer is at least one selected from a random copolymer or a block copolymer formed by propylene and other C 2-20 α-olefins, and a terpolymer of propylene, ethylene and at least one other C 2-20 α-olefin, or a mixture of at least two of them. Among them, the weight ratio of the propylene unit in the propylene copolymer is more than 50%.

[0028] Preferably, the melt index of the polyolefin elastomer measured according to ISO1133 under a load of 2.16 kg and at a temperature of 190 °C is 0.1 to 5.0 g / 10 min, preferably 0.2 to 2.0 g / 10 min.

[0029] Preferably, the polyolefin elastomer is a copolymer of ethylene and propylene, a copolymer of ethylene and 1-butene, a copolymer of ethylene and 1-hexene or a copolymer of ethylene and 1-octene.

[0030] Preferably, the melt index of the polyethylene measured according to ISO1133 under a load of 2.16 kg and at a temperature of 190 °C is 0.5 to 20 g / 10 min, preferably 1 to 5 g / 10 min.

[0031] Preferably, the polyethylene is linear low-density polyethylene or high-density polyethylene.

[0032] Preferably, the polar monomer is at least one selected from glycidyl methacrylate, maleic anhydride, fumaric acid, itaconic acid, diisopropyl maleate, citraconic acid and its anhydride, acrylic acid, vinyl succinic anhydride, methacrylic acid, methyl acrylate, ethyl acrylate and methyl methacrylate, or a mixture of at least two of them.

[0033] Preferably, the initiator is at least one of benzoyl peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, lauroyl peroxide, cumene hydroperoxide, di-tert-butyl peroxide, tert-butyl hydroperoxide, tert-butyl peroxy pivalate, tert-butyl peroxy benzoate, diisopropyl peroxydicarbonate, and dicyclohexyl peroxydicarbonate, or a mixture of at least two of them.

[0034] Preferably, the auxiliary agent is triallyl isocyanurate; antioxidant such as 1010; electron donor such as N,N-dimethylformamide; viscosity regulator such as low molecular weight wax; grafting auxiliary agent such as styrene; tackifying resin such as modified phenolic resin TKM-M80; light aging resistant agent; anti-dripping agent; heat stabilizer; release agent; nucleating agent, or a mixture of at least two of them.

[0035] Preferably, in the barrier layer, the metal layer is formed by winding aluminum foil or stainless steel strip.

[0036] The non-metal layer is formed by extruding EVOH, PA or PVDF on the surface of the elastomeric adhesive layer.

[0037] Preferably, during the winding process of the aluminum foil or stainless steel strip, the width of the laminate is 1 / 3 to 3 / 4 of the width of the aluminum foil and stainless steel strip respectively. Preferably, the aluminum foil or stainless steel strip is wound in a single layer or two layers.

[0038] Preferably, the fibers in the reinforcing layer are selected from carbon fibers, glass fibers, basalt fibers, aramid fibers, ultra-high molecular weight polyethylene fibers, and steel wires.

[0039] Preferably, the fiber tape is formed by the following steps:

[0040] 1) Mix the components of the elastomeric adhesive to prepare elastomeric adhesive particles;

[0041] 2) Impregnate the fibers: impregnate the fibers in the melt of the elastomeric adhesive, and form a fiber tape after extrusion and cooling.

[0042] Preferably, the step of impregnating the fibers is carried out in a continuous fiber impregnating machine, the width of the flat-laid fibers is 100 to 200 mm, and the impregnating temperature is 230 to 270 °C.

[0043] Preferably, the thickness of the fiber tape is 0.05 to 0.5 mm.

[0044] Preferably, the weight percentage of the fibers in the fiber tape is 40% to 60%.

[0045] Preferably, the materials of each layer of the high-barrier flexible composite pipe are selected as follows according to the inner diameter of the pipe:

[0046] 1) When the inner diameter of the high-barrier flexible composite pipe is 20 mm to less than 160 mm, the materials of the inner layer and the outer layer are independently selected from PE, PP, PET, PA, and PVDF respectively;

[0047] 2) When the inner diameter of the high-barrier flexible composite pipe is 160 mm to less than 480 mm, the material of the inner layer is selected from TPU, TPE, EPDM, styrene-butadiene rubber, nitrile rubber, silicone rubber, etc., and the material of the outer layer is selected from PE, PP, PET, PA, and PVDF;

[0048] 3) When the inner diameter of the high-barrier flexible composite pipe is greater than or equal to 480 mm, the materials of the inner layer and the outer layer are independently selected from TPU, TPE, EPDM, styrene-butadiene rubber, nitrile rubber, silicone rubber, etc.

[0049] Preferably, the thickness of the inner layer is 1 to 10 mm.

[0050] Preferably, the thickness of the elastomeric adhesive layer is 0.1 to 1 mm, preferably 0.1 to 0.6 mm.

[0051] Preferably, the thickness of the aluminum foil and the stainless steel strip is 0.04 to 0.2 mm.

[0052] Preferably, the thickness of the non-metallic layer is 0.1 to 0.6 mm, more preferably 0.1 to 0.5 mm.

[0053] Preferably, the number of winding layers of the fiber tape is 2 to 10 layers.

[0054] Preferably, the thickness of the outer layer is 1 to 10 mm.

[0055] According to the second aspect of the present invention, there is provided a method for preparing the high-barrier flexible composite pipe of the present invention, which comprises the following steps:

[0056] i) Extruding the inner layer using a fiber tape winding extruder;

[0057] ii) Extruding an elastomeric adhesive layer on the outer wall of the inner layer;

[0058] iii) Winding aluminum foil and stainless steel strip on the elastomeric adhesive layer to form a metal barrier layer; or, forming a non-metallic barrier layer by extruding EVOH, PA, or PVDF on the surface of the elastomeric adhesive layer;

[0059] iv) Winding preheated fiber tape on the outer wall of the barrier layer at an angle of 45 to 75° with the pipe center, and the number of winding layers is 2 to 10 layers to form a reinforcing layer; and

[0060] v) Extrude the outer layer, with its bushing on the surface of the fiber tape, and cool to obtain a high-barrier flexible composite pipeline. The fiber tape is formed through the following steps:

[0061] 1) Mix the components of the elastomeric adhesive to prepare elastomeric adhesive particles;

[0062] 2) Impregnate the fibers: Immerse the fibers in the melt of the elastomeric adhesive, and extrude and cool to form a fiber tape.

[0063] Preferably, the thickness of the elastomeric adhesive layer is 0.1 - 1 mm, preferably 0.1 - 0.6 mm.

[0064] Preferably, in the barrier layer, the metal barrier layer is formed by winding aluminum foil or stainless steel tape, and the non-metal barrier layer is formed by extruding EVOH, PA or PVDF on the surface of the elastomeric adhesive layer.

[0065] Preferably, the thickness of the aluminum foil, stainless steel tape and non-metal tape is 0.04 - 0.2 mm, and the width of the laminate during winding is 1 / 3 - 3 / 4 of the width of the aluminum foil, stainless steel tape and non-metal tape.

[0066] Preferably, the step of impregnating the fibers is carried out in a continuous fiber impregnating machine, the width of the flat-laid fibers is 100 - 200 mm, and the impregnation temperature of the elastomeric adhesive is 230 - 270 °C.

[0067] Preferably, the thickness of the fiber tape is 0.05 - 0.5 mm.

[0068] Preferably, the weight percentage of the fibers in the fiber tape is 40% - 60%.

[0069] Preferably, in step ii), the prestress during winding the fiber tape is 1 - 50 N.

[0070] Preferably, the following materials are selected for each layer of the high-barrier flexible composite pipeline according to the pipeline diameter:

[0071] 1) When the inner diameter of the high-barrier flexible composite pipeline is 20 mm to less than 160 mm, the materials of the inner layer and the outer layer are independently selected from PE, PP, PET, PA and PVDF;

[0072] 2) When the inner diameter of the high-barrier flexible composite pipeline is 160 mm to less than 480 mm, the material of the inner layer is selected from TPU, TPE, EPDM, styrene-butadiene rubber, nitrile rubber and silicone rubber, etc., and the material of the outer layer is selected from PE, PP, PET, PA and PVDF;

[0073] 3) When the inner diameter of the high-barrier flexible composite pipe is greater than or equal to 480 mm, the materials of the inner layer and the outer layer are independently selected from TPU, TPE, EPDM, styrene-butadiene rubber, nitrile rubber, silicone rubber, etc.

[0074] Preferably, the thickness of the inner layer is 1-10 mm.

[0075] Preferably, the thickness of the elastomeric adhesive layer is 0.1-1 mm, preferably 0.1-0.6 mm.

[0076] Preferably, the thickness of the aluminum foil and the stainless steel strip is 0.04-0.2 mm.

[0077] Preferably, the thickness of the non-metal layer is 0.1-0.6 mm, more preferably 0.1-0.5 mm.

[0078] Preferably, the number of winding layers of the fiber tape is 2-10.

[0079] Preferably, the thickness of the outer layer is 1-10 mm.

[0080] The high-barrier flexible composite pipe of the present invention enhances the flexibility of the pipe by preferably selecting the inner and outer layer materials for pipes of different diameters, and realizes the long-distance jointless rapid laying of the pipe. At the same time, a gas barrier layer is added to reduce the risk of gas leakage. The fiber layer and the barrier layer are combined with the pipe matrix through an elastomeric adhesive to overcome the risk of delamination; different inner and outer layer materials are selected for pipes of different diameters, which not only ensures the strength of the pipe but also provides good flexibility, realizing the long-distance coiling of the pipe; the high-barrier layer is added by winding or coextrusion to reduce the risk of gas leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 It is a schematic diagram showing the layer structure of the high-barrier flexible composite pipe according to the present invention.

[0082] REFERENCE SIGNS

[0083] 1 - Inner layer

[0084] 2 - Elastomeric adhesive layer

[0085] 3 - Barrier layer

[0086] 4 - Reinforcing layer

[0087] 5 - Outer layer DETAILED DESCRIPTION OF THE INVENTION

[0088] The present invention will be described in detail below with reference to the embodiments. The embodiments of the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0089] Measurement of the coiling radius

[0090] Use the Zhangjiagang Hengruitai Machinery 50-110 automatic coil winding machine for coiling. The maximum coiling radius is 1800 mm. Record the minimum coiling radius of the pipeline under the maximum torque. The coiling radius of the pipeline that cannot be coiled is uniformly recorded as >1800 mm.

[0091] Measurement of gas permeability

[0092] The gas permeability is measured by the differential pressure method, that is, nitrogen gas at the designed pressure is filled into the pipeline, the inflation port is sealed, and the pressure of the remaining gas in the pipeline is measured after 24 hours of testing. The gas permeability can be obtained through the pressure reduction ratio, and the unit is % / h. In the present invention, the gas permeability is tested under a pressure of 1 MPa.

[0093] 1. Preparation of elastomeric adhesive

[0094] After mixing each component by a high-speed mixer, it is reacted and extruded into pellets by a twin-screw extruder. Among them, the ratio of the length to the diameter of the twin-screw is greater than 30:1, the processing temperature of each section is 180-230 °C, and after extrusion, it is pelletized, air-dried and stored for use.

[0095] 2. Impregnation of fiber tape

[0096] Use a continuous fiber impregnation machine to impregnate the fiber. The fiber is laid flat and passes through a sheet die with a width of 50-935 mm, and is mixed with the melt of the elastomeric adhesive at the die outlet. The temperature of the melt of the elastomeric adhesive is 230-270 °C. After extrusion and cooling, a continuous tape is formed and coiled for standby.

[0097] 3. Extrusion of composite pipeline

[0098] Use a fiber tape winding extruder to extrude the composite pipeline. First, extrude the inner layer 1 of the pipeline and the elastomeric adhesive layer 2 through a multi-layer coextrusion die head, wind or extrude the barrier layer 3 on the elastomeric adhesive layer 2, and then wind the pre-heated fiber impregnated tape. The winding angle forms an angle of 45-70° with the center of the pipeline, the prestress of the fiber tape is 1-50 N, and the number of winding layers can be 2-10 layers to form the reinforcing layer 4. Then extrude the outer layer 5 of the composite pipeline through a pipeline extruder and line it on the surface of the fiber tape. After extrusion, it is cooled and sized, and then coiled, wound and packaged.

[0099] Example 1

[0100] 1. Preparation of elastomeric adhesive

[0101] Mix 5 parts by weight of homopolypropylene (PPH, L5E89, melt index of 3.5 g / 10 min), 60 parts by weight of elastomer (POE, 8150, melt index of 0.5 g / 10 min), 35 parts by weight of linear low density polyethylene (LLDPE, 7042, melt index of 2 g / 10 min), 0.5 part by weight of 2,5 - dimethyl - 2,5 - bis(tert - butylperoxy)hexane, 3.5 parts by weight of MAH, 1 part by weight of styrene (grafting aid), and 0.1 part by weight of Irganox1010 in a high - speed mixer until well - mixed, and then extrude and pelletize through a twin - screw extruder. Among them, the processing temperature of each section of the twin - screw is 180 - 230 °C to prepare an elastomer adhesive.

[0102] 2. Fiber tape impregnation:

[0103] Use a continuous fiber impregnation machine to impregnate the glass fiber. The glass fiber is laid flat and passes through a sheet - shaped die with a width of 155 mm, and is mixed with the melt of the elastomer adhesive at the die outlet. The temperature of the elastomer adhesive melt is 250 °C. After extrusion and cooling, a continuous tape is formed and coiled for standby. The thickness of the fiber tape is 0.1 mm, and the weight fraction of the glass fiber in the fiber tape is 50%.

[0104] 3. Extrusion of high - barrier flexible composite pipes

[0105] Use a fiber - tape winding extruder to extrude composite pipes. First, extrude the inner layer 1 of the pipe. The inner - layer material is HDPE (6100M), the inner diameter of the pipe is 110 mm, and the thickness is 4 mm. At the same time, co - extrude an elastomer adhesive layer 2 with a thickness of 0.3 mm formed by the above - mentioned elastomer adhesive on the outside. Then wind a 0.1 - mm - thick and 155 - mm - wide Al tape on the elastomer adhesive layer 2, and the laminated width is 2 / 3 of the width of the Al tape to form a barrier layer 3. Then wind the pre - heated fiber - impregnated tape on the barrier layer. The winding angle forms a 45° angle with the center of the pipe. The prestress of the fiber tape is 10 N, and the number of winding layers is 6 layers to form a reinforcement layer 4. Then extrude the outer layer 5 of the composite pipe through a pipe extruder. The outer - layer material is HDPE (6100M), and the thickness is 2 mm. Line it on the surface of the fiber tape. After extrusion, cool and size it, and then coil, wind, and package. The performance is shown in Table 1.

[0106] Example 2

[0107] 1. Preparation of elastomer adhesive

[0108] Mix 10 parts by weight of homopolypropylene (PPH, L5E89), 60 parts by weight of elastomer (POE, 8150), 30 parts by weight of linear low-density polyethylene (LLDPE, 7042), 0.5 part by weight of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 3.5 parts by weight of MAH, 1 part by weight of styrene, and 0.1 part by weight of Irganox1010 in a high-speed mixer until thoroughly mixed, and then conduct reactive extrusion granulation through a twin-screw extruder. Among them, the processing temperature of each section of the twin-screw is 180-230 °C to prepare an elastomer adhesive.

[0109] 2. Fiber tape impregnation

[0110] Use a continuous fiber impregnator to impregnate the glass fiber. The fibers are laid flat and pass through a sheet die with a width of 155 mm, and are mixed with the elastomer adhesive melt at the die outlet. The temperature of the adhesive melt is 250 °C. After extrusion and cooling, a continuous tape is formed and coiled for standby. The thickness of the fiber tape is 0.1 mm, and the weight fraction of the glass fiber in the fiber tape is 50%.

[0111] 3. Extrusion of high-barrier flexible composite pipes

[0112] Use a fiber tape winding extruder to extrude composite pipes. First, extrude the inner layer 1 of the pipe. The inner layer material is TPE (Shandong Dawn 7002), the inner diameter of the pipe is 360 mm, and the thickness is 6 mm. At the same time, co-extrude an elastomer adhesive layer 2 with a thickness of 0.3 mm formed by the above-mentioned elastomer adhesive on the outside. Then wind a 0.1 mm thick and 155 mm wide Al tape on the elastomer adhesive layer 2, and the laminated width is 2 / 3 of the width of the Al tape to form a barrier layer 3. Then wind a pre-heated fiber impregnated tape on the barrier layer. The winding angle forms a 60° angle with the center of the pipe. The prestress of the fiber tape is 20 N, and the number of winding layers is 4 layers to form a reinforcement layer 4. Then extrude the outer layer 5 of the composite pipe through a pipe extruder. The outer layer material is HDPE, and the thickness is 2 mm. Line the surface of the fiber tape. After extrusion, cool and size, and coil and wind for packaging. The performance is shown in Table 1.

[0113] Example 3

[0114] 1. Preparation of elastomer adhesive

[0115] 5 parts by weight of homopolypropylene (PPH, L5E89), 60 parts by weight of elastomer (POE, 8150), 35 parts by weight of linear low density polyethylene (LLDPE, 7042), 0.5 part by weight of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 3.5 parts by weight of MAH, 1 part by weight of styrene and 0.1 part by weight of Irganox1010 were thoroughly mixed in a high-speed mixer and then reaction extruded and pelletized through a twin-screw extruder. Among them, the processing temperature of each section of the twin-screw was 180-230°C to prepare an elastomer adhesive.

[0116] 2. Fiber tape impregnation

[0117] The glass fiber was impregnated using a continuous fiber impregnating machine. The glass fiber was laid flat and passed through a sheet die with a width of 155 mm and was mixed with the melt of the elastomer adhesive at the die outlet. The melt temperature of the elastomer adhesive was 250°C. After extrusion and cooling, a continuous tape was formed and coiled for standby. The thickness of the fiber tape was 0.1 mm, and the weight fraction of the glass fiber in the fiber tape was 50%.

[0118] 3. Extrusion of high-barrier flexible composite pipes

[0119] A fiber tape winding extruder was used for the extrusion of composite pipes. First, the inner layer 1 of the pipe was extruded using a three-layer pipe co-extrusion machine. The materials from the inside to the outside were TPE, elastomer adhesive, and EVOH in sequence. The inner diameter of the pipe was 600 mm, the thickness of the inner layer was 6 mm, and the thicknesses of the elastomer adhesive layer and the EVOH (barrier layer) were 0.3 mm respectively. The pre-heated fiber impregnated tape was wound on the barrier layer. The winding angle was at an angle of 72° with the pipe center. The prestress of the fiber tape was 40 N, and the number of winding layers was 2 layers to form a reinforcing layer. Then, the outer layer 5 of the composite pipe was extruded through a pipe extruder. The outer layer material was TPE with a thickness of 4 mm. It was sleeved on the surface of the fiber tape. After extrusion, it was cooled and sized, and then coiled, wound, and packaged. The performance is shown in Table 1.

[0120] Table 1: Materials and properties of high-barrier flexible composite pipes prepared in Examples 1 to 3

[0121]

[0122] Comparative Example 1

[0123] Except for not forming the elastomer adhesive layer and the barrier layer and using the raw materials in Table 2, the composite pipe was prepared in the same manner as in Example 2. The performance is shown in Table 2.

[0124] Comparative Example 2

[0125] Except for not forming the elastomer adhesive layer and the barrier layer and using the raw materials in Table 2, the composite pipe was prepared in the same manner as in Example 2. The performance is shown in Table 2.

[0126] Table 2: Materials and properties of the pipes prepared in Comparative Examples 1 to 3

[0127]

[0128] It can be seen that when the diameters of Comparative Examples 1 and 2 are large, the coiling radius is very large, which is not conducive to coiling and transportation. And when there is no barrier layer, the gas permeability is relatively large.

Claims

1. A high-barrier flexible composite pipe, which comprises: (1) An inner layer formed of a thermoplastic resin or an elastomer; (2) An elastomeric adhesive layer formed on the outer wall of the inner layer; (3) A barrier layer, which is a metal layer or a non-metal layer with a thickness of not less than 0.04 mm, and is formed on the surface of the elastomeric adhesive layer; (4) A reinforcing layer, which is formed by winding a fiber tape formed by fibers impregnated with an elastomeric adhesive on the surface of the barrier layer at an angle of 45 to 75° with the center of the pipe, and (5) An outer layer bonded to the surface of the reinforcing layer, which is formed of a thermoplastic resin or an elastomer; wherein, the elastomeric adhesive in the elastomeric adhesive layer and the reinforcing layer comprises the following components: (a) 0 to 20 parts by weight, preferably 5 to 15 parts by weight of polypropylene; (b) 50 to 70 parts by weight, preferably 55 to 70 parts by weight of a polyolefin elastomer; (c) 0 to 40 parts by weight, preferably 5 to 40 parts by weight of polyethylene; (d) 0.5 to 5 parts by weight of a polar monomer; (e) 0.2 to 1.5 parts by weight of an initiator; and (f) 0 to 5 parts by weight of an auxiliary agent.

2. The high-barrier flexible composite pipe according to claim 1, wherein, the gas permeability of the high-barrier flexible composite pipe is 0.035% / h or less, more preferably 0.030% / h or less; and / or the melt index of the polypropylene measured according to ISO1133 under a load of 2.16 kg and at a temperature of 230 °C is 0.5 g to 5 g / 10 min, preferably 0.5 to 4.0 g / 10 min; and / or the polypropylene is a propylene homopolymer or a propylene copolymer; and / or the melt index of the polyolefin elastomer measured according to ISO1133 under a load of 2.16 kg and at a temperature of 190 °C is 0.1 to 5.0 g / 10 min, preferably 0.2 to 2.0 g / 10 min; and / or the melt index of the polyethylene measured according to ISO1133 under a load of 2.16 kg and at a temperature of 190 °C is 0.5 to 20 g / 10 min, preferably 1 to 5 g / 10 min.

3. The high-barrier flexible composite pipe according to claim 1 or 2, wherein, The propylene copolymer is selected from propylene and other C 2-20 A random copolymer or a block copolymer formed by α-olefin, and propylene, ethylene and at least one other C 2-20 At least one of the α-olefin terpolymers, or a mixture of at least two of them; and / or the polyolefin elastomer is an ethylene and propylene copolymer, an ethylene and 1-butene copolymer, a copolymer of ethylene and 1-hexene or a copolymer of ethylene and 1-octene; and / or the polyethylene is linear low density polyethylene or high density polyethylene.

4. The high-barrier flexible composite pipe according to any one of claims 1 to 3, wherein, the polar monomer is at least one of glycidyl methacrylate, maleic anhydride, fumaric acid, itaconic acid, diisopropyl maleate, citraconic acid and its anhydride, acrylic acid, vinyl succinic anhydride, methacrylic acid, methyl acrylate, ethyl acrylate and methyl methacrylate, or a mixture of at least two; and / or The initiator is at least one of benzoyl peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, lauroyl peroxide, cumene hydroperoxide, di-tert-butyl peroxide, tert-butyl hydroperoxide, tert-butyl peroxy pivalate, tert-butyl peroxybenzoate, diisopropyl peroxydicarbonate, and dicyclohexyl peroxydicarbonate, or a mixture of at least two of them; and / or The auxiliary agent is triallyl isocyanurate; antioxidants such as 1010; electron donors such as N,N-dimethylformamide; viscosity regulators such as low molecular weight wax; grafting aids such as styrene; tackifying resins such as modified phenolic resin TKM-M80; light aging resistant agents; anti-dripping agents; heat stabilizers; release agents; nucleating agents, or a mixture of at least two of them.

5. The high-barrier flexible composite pipe according to any one of claims 1 to 4, wherein, In the barrier layer, the metal layer is formed by winding aluminum foil or stainless steel strip; The non-metal layer is formed by extruding EVOH, PA or PVDF on the surface of the elastomeric adhesive layer; and / or The fibers in the reinforcing layer are selected from carbon fibers, glass fibers, basalt fibers, aramid fibers, ultra-high molecular weight polyethylene fibers, and steel wires; and / or The weight percentage of the fibers in the fiber tape is 40% to 60%; and / or The thickness of the fiber tape is 0.05 to 0.5 mm; and / or The thickness of the inner layer is 1 to 10 mm; and / or The thickness of the elastomeric adhesive layer is 0.1 to 1 mm, preferably 0.1 to 0.6 mm; and / or The thickness of the aluminum foil and stainless steel strip is 0.04 to 0.2 mm; and / or The thickness of the non-metal layer is 0.1 to 0.6 mm, more preferably 0.1 to 0.5 mm; and / or The number of winding layers of the fiber tape is 2 to 10 layers; and / or The thickness of the outer layer is 1 to 10 mm.

6. The high-barrier flexible composite pipe according to any one of claims 1 to 5, wherein, The widths of the laminations during the winding of the aluminum foil and stainless steel strip are respectively 1 / 3 to 3 / 4 of the widths of the aluminum foil and stainless steel strip; and / or The fiber tape is formed by the following steps: 1) Mix the components of the elastomeric adhesive to prepare elastomeric adhesive particles; 2) Impregnate the fibers: Immerse the fibers in the melt of the elastomeric adhesive, and extrude and cool to form a fiber tape; preferably, the step of impregnating the fibers is carried out in a continuous fiber impregnating machine, the width of the flat-laid fibers is 100 to 200 mm, and the impregnating temperature is 230 to 270 °C.

7. The high-barrier flexible composite pipe according to any one of claims 1 to 6, wherein, The materials of each layer of the high-barrier flexible composite pipe are selected as follows according to the inner diameter of the pipe: 1) When the inner diameter of the high-barrier flexible composite pipe is 20 mm to less than 160 mm, the materials of the inner layer and the outer layer are independently selected from PE, PP, PET, PA, and PVDF; 2) When the inner diameter of the high-barrier flexible composite pipe is from 160 mm to less than 480 mm, the material of the inner layer is selected from TPU, TPE, EPDM, styrene-butadiene rubber, nitrile rubber and silicone rubber, and the material of the outer layer is selected from PE, PP, PET, PA and PVDF; 3) When the inner diameter of the high-barrier flexible composite pipe is greater than or equal to 480 mm, the materials of the inner layer and the outer layer are independently selected from TPU, TPE, EPDM, styrene-butadiene rubber, nitrile rubber and silicone rubber respectively.

8. A method for preparing the high-barrier flexible composite pipe according to any one of claims 1 to 7, which comprises the following steps: i) Extruding the inner layer using a fiber tape winding extruder; ii) Extruding an elastomeric adhesive layer on the outer wall of the inner layer; iii) Winding aluminum foil and stainless steel tape on the elastomeric adhesive layer to form a metal barrier layer; or forming a non-metal barrier layer by extruding EVOH, PA or PVDF on the outer surface of the elastomeric adhesive layer; iv) Winding preheated fiber tapes on the outer wall of the barrier layer at an angle of 45-75° to the center of the pipe, and the number of winding layers is 2-10 to form a reinforcing layer; and v) Extruding the outer layer, which is sleeved on the surface of the fiber tape, and cooling to obtain the high-barrier flexible composite pipe, The fiber tape is formed by the following steps: 1) Mixing the components of the elastomeric adhesive to prepare elastomeric adhesive particles; 2) Impregnating fibers: Impregnating the fibers in the melt of the elastomeric adhesive, and extruding and cooling to form fiber tapes.

9. The method for preparing a high-barrier flexible composite pipe according to claim 8, wherein, The step of impregnating fibers is carried out in a continuous fiber impregnating machine, the width of the fiber laying is 100-200 mm, and the impregnating temperature of the elastomeric adhesive is 230-270 °C; and / or In the barrier layer, the metal barrier layer is formed by winding aluminum foil or stainless steel tape, and the non-metal barrier layer is formed by extruding EVOH, PA or PVDF on the surface of the elastomeric adhesive layer.

10. The method for preparing a high-barrier flexible composite pipe according to claim 8, wherein, The materials of each layer of the high-barrier flexible composite pipe are selected as follows according to the pipe diameter: 1) When the inner diameter of the high-barrier flexible composite pipe is from 20 mm to less than 160 mm, the materials of the inner layer and the outer layer are independently selected from PE, PP, PET, PA and PVDF; 2) When the inner diameter of the high-barrier flexible composite pipe is from 160 mm to less than 480 mm, the material of the inner layer is selected from TPU, TPE, EPDM, styrene-butadiene rubber, nitrile rubber and silicone rubber, and the material of the outer layer is selected from PE, PP, PET, PA and PVDF; and 3) When the inner diameter of the high-barrier flexible composite pipe is greater than or equal to 480 mm, the materials of the inner layer and the outer layer are independently selected from TPU, TPE, EPDM, styrene-butadiene rubber, nitrile rubber and silicone rubber respectively.

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