High-light high-brightness oxygen-blocking PERT pipe and preparation method thereof

Abstract

The invention discloses a high-light high-brightness oxygen-resistant PERT pipe and a preparation method thereof, and relates to the field of polyethylene pipes, the high-light high-brightness oxygen-resistant PERT pipe comprises an inner layer and an outer layer made of PERT materials, and an oxygen-resistant layer connecting the inner layer and the outer layer, and the oxygen-resistant layer is mainly made of a blending material of TLCP and PE. A blending modified material of TLCP and PE is adopted as the oxygen barrier layer, compatibility between TLCP and PE is fully utilized, interface bonding of the oxygen barrier layer, the inner layer and the outer layer is achieved, the process of adding an adhesive layer co-extrusion layer is reduced, the production process is simplified, meanwhile, a macromolecular chain structure of TLCP is regular and easy to orientate, an effective oxygen barrier can be formed in the blending material, and the oxygen barrier performance is improved. Therefore, the oxygen barrier performance of the pipeline is further improved.

Description

Technical Field

[0001] The invention relates to the field of polyethylene pipes, and in particular to a high-gloss and high-brightness oxygen-barrier PERT pipe and a preparation method thereof. Background Art

[0002] PERT (heat-resistant polyethylene) has good flexibility, resistance to hydrostatic pressure and high temperature resistance, and is widely used in heating pipes. However, the current heating pipes have poor oxygen barrier properties. During long-term use, oxygen will gradually penetrate into the heating pipes, promoting the reproduction of microorganisms and bacteria and forming biological slime, which will increase the energy consumption of the heating system and even cause pipe blockage in severe cases. In addition, the oxygen that penetrates into the heating pipes will also accelerate the oxidation and rusting of metal components in the heating system.

[0003] The existing patent (patent number is 201620356409.1) discloses a PERT oxygen barrier tube, whose structure includes a PERT inner layer, the PERT inner layer is bonded to an oxygen barrier layer through a first bonding layer, the oxygen barrier layer is bonded to a PERT outer layer through a second bonding layer, the PERT outer layer is bonded to a reflective layer, a notch is provided on the oxygen barrier layer, an elastic oxygen barrier belt is installed in the notch, and the elastic oxygen barrier belt is connected to the oxygen barrier layer; however, this invention still has many problems in actual production and application. On the one hand, the layers of the oxygen barrier tube need to be bonded with an adhesive layer, which makes the production process complicated; on the other hand, the existing oxygen barrier layer has poor oxygen barrier effect, the pipeline is prone to aging, and the service life is short.

[0004] Therefore, how to develop a high-gloss and high-brightness oxygen-barrier PERT pipe, using a blended modified material of TLCP and PE as the oxygen barrier layer, not only achieves the interface bonding between the oxygen barrier layer and the inner and outer layers, reduces the process of adding a rubber layer co-extrusion layer, simplifies the production process, and at the same time, further improves the oxygen barrier performance of the pipeline, has become a technical problem that needs to be urgently solved by people in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a high-gloss and high-brightness oxygen-barrier PERT pipe and a preparation method thereof, which adopts a blended modified material of TLCP and PE as the oxygen barrier layer, which not only realizes the interface bonding between the oxygen barrier layer and the inner and outer layers, but also reduces the process of adding a rubber layer co-extrusion layer, simplifies the production process, and at the same time, further improves the oxygen barrier performance of the pipeline.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The invention discloses a high-gloss and high-brightness oxygen-barrier PERT pipe, which is a three-layer structure formed by co-extrusion, including an inner layer and an outer layer of PERT material, and an oxygen-barrier layer connecting the inner layer and the outer layer, wherein the oxygen-barrier layer is mainly made of a blend of TLCP and PE.

[0008] Preferably, the oxygen barrier layer further comprises a compatibilizer, and the compatibilizer is made of one or more of maleic acid-modified polyethylene, silane coupling agent KH550, silane coupling agent KH560, silane coupling agent KH570, silane coupling agent KH792 and titanate coupling agent.

[0009] Preferably, the mass ratio of TLCP, PE and compatibilizer in the oxygen barrier layer is:

[0010] TLCP: 10%~50%;

[0011] PE: 45%~89%;

[0012] Compatibilizer: 1%~5%.

[0013] Preferably, the outer layer also includes additives and antioxidants, and the additives mainly include polyethers, higher fatty hydrocarbons, amide compounds, ethylene bisstearamide and octadecyl alcohol; the antioxidant is made of one or more of antioxidant 1010, antioxidant 1076, antioxidant CA, antioxidant 164, antioxidant TPP and antioxidant TNP.

[0014] Preferably, the mass proportion of PERT, additives and antioxidants in the outer layer is,

[0015] PERT: 95.8%-98.5%;

[0016] Additives: 0.5%~1.2%;

[0017] Antioxidant: 1%~3%.

[0018] Preferably, the wall thickness of the high-gloss and high-brightness oxygen-barrier PERT pipe is 2.2 mm to 2.4 mm, wherein the thickness of the inner layer is 1.96 mm to 1.98 mm, the thickness of the oxygen-barrier layer is 0.04 mm to 0.12 mm, and the thickness of the outer layer is 0.2 mm to 0.3 mm.

[0019] A method for preparing a high-gloss and high-brightness oxygen-barrier PERT pipe comprises the following steps:

[0020] Step 1, weighing PERT, additives and antioxidants according to proportion and melt-mixing them, and then granulating them through an extruder to obtain outer layer pellets;

[0021] Step 2, weighing TLCP, PE and compatibilizer according to proportion and melt blending, and then granulating through an extruder to obtain oxygen barrier layer pellets;

[0022] Step 3: Melt and plasticize the outer layer granules, the oxygen barrier layer granules and the inner layer PERT raw materials respectively, and then perform composite extrusion to obtain high-gloss and high-brightness oxygen barrier PERT pipes.

[0023] Preferably, the high-gloss and high-brightness oxygen-barrier PERT pipe is co-extruded by three extruders, wherein the first extruder is used to extrude the inner layer, the barrel temperature is 180℃~200℃, and the mold temperature is 190℃~210℃; the second extruder is used to extrude the oxygen-barrier layer, the barrel temperature is 175℃~200℃, and the mold temperature is 190℃~215℃; the third extruder is used to extrude the outer layer, the barrel temperature is 180℃~200℃, and the mold temperature is 190℃~210℃.

[0024] Compared with the prior art, the beneficial technical effects of the present invention are:

[0025] 1) The present invention adopts a blended modified material of TLCP and PE to prepare the oxygen barrier layer of the pipe. Since the polymer chain structure of TLCP is regular and easy to orient, it can form an effective oxygen barrier in the blended material. This characteristic makes the TLCP / PE blend material significantly improved in oxygen barrier performance, which is much higher than the traditional PE or PERT pipe. In addition, TLCP also has excellent water resistance, heat resistance and scratch resistance, which can also be maintained and improved in the blended material, further enhancing the comprehensive performance of the material. The blended material of TLCP and PE is used as the oxygen barrier layer of the pipe, which can not only significantly reduce the oxygen permeability, but also effectively prevent oxygen from penetrating and dissolving into the medium transported in the pipe, thereby avoiding oxidation corrosion to metal pipes, metal equipment, etc. in the system;

[0026] 2) TLCP and PE have good compatibility. When the two are compounded, they can form a tight bond without adhesive bonding. This feature enables the oxygen barrier layer formed by the TLCP / PE blend to form a good interface bond with the inner and outer layers of the PERT material during the co-extrusion process. No additional adhesive layer is required to increase the adhesion between the layers, which reduces production costs and improves production efficiency.

[0027] 3) The addition of additives can improve the brightness and smoothness of the outer layer of the pipe, improve the appearance quality of the pipe, and enhance the market competitiveness of the product.

[0028] In general, the present invention adopts the blended modified material of TLCP and PE as the oxygen barrier layer, which not only realizes the interface bonding between the oxygen barrier layer and the inner and outer layers, reduces the process of adding the rubber layer co-extrusion layer, simplifies the production process, but also further improves the oxygen barrier performance of the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] Figure 1 This is a structural schematic diagram of a high-gloss and high-brightness oxygen-barrier PERT pipe of the present invention;

[0031] Figure 2It is a radial cross-sectional view of a high-gloss and high-brightness oxygen-barrier PERT pipe of the present invention.

[0032] Explanation of the reference numerals: 1. inner layer; 2. oxygen barrier layer; 3. outer layer. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] like Figure 1-2 As shown, a high-gloss and high-brightness oxygen-barrier PERT pipe is a three-layer structure formed by co-extrusion, including an inner layer 1 and an outer layer 3 made of PERT material, and an oxygen-barrier layer 2 connecting the inner layer 1 and the outer layer 3, and the oxygen-barrier layer 2 is mainly made of a blend of TLCP and PE.

[0035] Specifically, the oxygen barrier layer 2 further includes a compatibilizer, and the compatibilizer is made of one or more of maleic acid-modified polyethylene, silane coupling agent KH550, silane coupling agent KH560, silane coupling agent KH570, silane coupling agent KH792 and titanate coupling agent.

[0036] Specifically, PE mainly includes Zhongsha PN049, Dushanzi 4808, and Jilin Petrochemical 100S.

[0037] Specifically, the mass proportion of TLCP, PE and compatibilizer in the oxygen barrier layer 2 is:

[0038] TLCP: 10%~50%;

[0039] PE: 45%~89%;

[0040] Compatibilizer: 1%~5%.

[0041] Specifically, TLCP (thermotropic liquid crystal polymer) has excellent oxygen barrier properties, which are 2 to 10 times that of EVOH (ethylene / vinyl alcohol copolymer). After TLCP is blended with PE (polyethylene), the polymer chain structure of TLCP is regular and easy to orient, which can form an effective oxygen barrier in the material. This feature significantly improves the oxygen barrier performance of TLCP / PE blended materials, which is much higher than traditional PE or PERT pipes. In addition, TLCP also has excellent water resistance, heat resistance and scratch resistance, which can also be maintained and improved in the blended materials, further enhancing the comprehensive performance of the material. Using the blended material of TLCP and PE as the oxygen barrier layer 2 of the pipe can not only significantly reduce the oxygen permeability, but also effectively prevent oxygen from penetrating and dissolving into the medium transported in the pipe, thereby avoiding oxidative corrosion to metal pipes, metal equipment, etc. in the system.

[0042] Specifically, TLCP and PE have good compatibility, and when the two are compounded, they can form a tight bond without the need for adhesive bonding. This property enables the oxygen barrier layer 2 formed by the TLCP / PE blended material to form a good interface bond with the inner and outer layers of the PERT material during the co-extrusion process, without the need for an additional adhesive layer to increase the adhesion between the layers, thereby reducing production costs and improving production efficiency.

[0043] Specifically, the outer layer 3 also includes additives and antioxidants, and the additives mainly include polyethers, higher fatty hydrocarbons, amide compounds, ethylene bisstearamide and octadecyl alcohol; the antioxidant is made of one or more of antioxidant 1010, antioxidant 1076, antioxidant CA, antioxidant 164, antioxidant TPP and antioxidant TNP.

[0044] Specifically, the mass proportion of PERT, additives and antioxidants in the outer layer 3 is:

[0045] PERT: 95.8%-98.5%;

[0046] Additives: 0.5%~1.2%;

[0047] Antioxidant: 1%~3%.

[0048] Specifically, the addition of the additive can improve the brightness and smoothness of the outer layer 3 of the pipe, improve the appearance quality of the pipe, and enhance the market competitiveness of the product.

[0049] Specifically, the PERT is made of Borouge 3466R, Dushanzi 3606, Lanzhou Petrochemical L5050, LG980, LGSP988, Total XRT70, Qilu Petrochemical QHM32F or Dalin XP9000.

[0050] Specifically, the wall thickness of the high-gloss and high-brightness oxygen-barrier PERT pipe is 2.2 mm to 2.4 mm, wherein the thickness of the inner layer 1 is 1.96 mm to 1.98 mm, the thickness of the oxygen-barrier layer 2 is 0.04 mm to 0.12 mm, and the thickness of the outer layer 3 is 0.2 mm to 0.3 mm.

[0051] A method for preparing a high-gloss and high-brightness oxygen-barrier PERT pipe comprises the following steps:

[0052] Step 1, weighing PERT, additives and antioxidants according to proportion and melt-mixing them, and then granulating them through an extruder to obtain outer layer pellets;

[0053] First, the raw materials are weighed according to the proportion of PERT, additives and antioxidants in the outer layer, and added into a plastic high-speed mixer for high-speed stirring until they are evenly mixed;

[0054] Secondly, the mixed materials are fed into the mixer through the feeder. The temperature of the mixer is set to 180℃±10℃. The two rotors of the mixer rotate in opposite directions at high speed to achieve the melting and mixing of the materials.

[0055] Then, the molten material is pressurized by a gear pump and filtered through a screen changer to filter out impurities, and then added to the extruder for extrusion, wherein the temperature of the die head is set at 210°C ± 10°C;

[0056] Finally, the underwater pelletizer cuts the strip polymer extruded from the extruder into pellets in water. The pellets are dehydrated, dried, vibrated and screened to obtain qualified outer layer pellets.

[0057] Step 2, weighing TLCP, PE and compatibilizer according to proportion and melt blending, and then granulating through an extruder to obtain oxygen barrier layer pellets;

[0058] The raw materials are weighed according to the proportion of TLCP, PE and compatibilizer in the oxygen barrier layer, and then extruded and granulated by a side-feed two-stage extruder granulator. The TLCP resin is melt-plasticized by an extruder, wherein the extrusion temperature is set at 260°C to 300°C, and the TLCP melt is squeezed into another extruder with a second feed port opened at the waist in a duck-stuffing manner. The TLCP melt is mixed with the PE and compatibilizer melts that are being melt-plasticized, and extruded after the blending is completed. The temperature of the extruded filamentary material is 205°C to 230°C, and then the stretching, orientation, cooling and pelletizing operation is performed to obtain the oxygen barrier layer pellets;

[0059] Step 3: Melt and plasticize the outer layer granules, the oxygen barrier layer granules and the inner layer PERT raw materials respectively, and then perform composite extrusion to obtain high-gloss and high-brightness oxygen barrier PERT pipes.

[0060] Specifically, the high-gloss and high-brightness oxygen-barrier PERT pipe is co-extruded by three extruders, wherein the first extruder is used to extrude the inner layer, the barrel temperature is 180℃~200℃, and the mold temperature is 190℃~210℃; the second extruder is used to extrude the oxygen-barrier layer, the barrel temperature is 175℃~200℃, and the mold temperature is 190℃~215℃; the third extruder is used to extrude the outer layer, the barrel temperature is 180℃~200℃, and the mold temperature is 190℃~210℃.

[0061] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0062] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A high-gloss and high-brightness oxygen-barrier PERT pipe, characterized by: The high-gloss and high-brightness oxygen-barrier PERT pipe is a three-layer structure formed by co-extrusion, comprising an inner layer (1) and an outer layer (3) made of PERT material, and an oxygen-barrier layer (2) connecting the inner layer (1) and the outer layer (3), wherein the oxygen-barrier layer (2) is mainly made of a blend of TLCP and PE.

2. The high-gloss and high-brightness oxygen-barrier PERT pipe according to claim 1, characterized in that: The oxygen barrier layer (2) further comprises a compatibilizer, and the compatibilizer is made of one or more of maleic acid-modified polyethylene, silane coupling agent KH550, silane coupling agent KH560, silane coupling agent KH570, silane coupling agent KH792 and titanate coupling agent.

3. The high-gloss and high-brightness oxygen-barrier PERT pipe according to claim 2, characterized in that: The mass proportion of TLCP, PE and compatibilizer in the oxygen barrier layer (2) is: TLCP: 10%~50%; PE: 45%~89%; Compatibilizer: 1%~5%.

4. The high-gloss and high-brightness oxygen-barrier PERT pipe according to claim 1, characterized in that: The outer layer (3) also includes auxiliary agents and antioxidants, wherein the auxiliary agents mainly include polyethers, higher fatty hydrocarbons, amide compounds, ethylene bisstearamide and octadecyl alcohol; the antioxidant is made of one or more of antioxidant 1010, antioxidant 1076, antioxidant CA, antioxidant 164, antioxidant TPP and antioxidant TNP.

5. The high-gloss and high-brightness oxygen-barrier PERT pipe according to claim 4, characterized in that: The mass proportion of PERT, additives and antioxidants in the outer layer (3) is: PERT: 95.8%-98.5%; Additives: 0.5%~1.2%; Antioxidant: 1%~3%.

6. The high-gloss and high-brightness oxygen-barrier PERT pipe according to claim 1, characterized in that: The wall thickness of the high-gloss and high-brightness oxygen-barrier PERT pipe is 2.2 mm to 2.4 mm, wherein the thickness of the inner layer (1) is 1.96 mm to 1.98 mm, the thickness of the oxygen-barrier layer (2) is 0.04 mm to 0.12 mm, and the thickness of the outer layer (3) is 0.2 mm to 0.3 mm.

7. A method for preparing a high-gloss and high-brightness oxygen-barrier PERT pipe according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1, weighing PERT, additives and antioxidants according to proportion and melt-mixing them, and then granulating them through an extruder to obtain outer layer pellets; Step 2, weighing TLCP, PE and compatibilizer according to proportion and melt blending, and then granulating through an extruder to obtain oxygen barrier layer pellets; Step 3: Melt and plasticize the outer layer granules, the oxygen barrier layer granules and the inner layer PERT raw materials respectively, and then perform composite extrusion to obtain high-gloss and high-brightness oxygen barrier PERT pipes.

8. The method for preparing a high-gloss and high-brightness oxygen-barrier PERT pipe according to claim 7, characterized in that: The high-gloss and high-brightness oxygen-barrier PERT pipe is co-extruded by three extruders. The first extruder is used to extrude the inner layer, the barrel temperature is 180℃~200℃, and the mold temperature is 190℃~210℃; the second extruder is used to extrude the oxygen-barrier layer, the barrel temperature is 175℃~200℃, and the mold temperature is 190℃~215℃; the third extruder is used to extrude the outer layer, the barrel temperature is 180℃~200℃, and the mold temperature is 190℃~210℃.

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