A PET composite material, its preparation method and application

Abstract

This invention belongs to the field of polymer materials technology, and specifically relates to a PET composite material, its preparation method, and its application. By weight, the raw materials for preparing the PET composite material of this invention include 70-95 parts of polyethylene terephthalate, 0-15 parts of polybutylene terephthalate, 3-10 parts of toughening agent, and 0.2-1 parts of anti-crystallization agent; the anti-crystallization agent includes at least one of polyethylene glycol, polyacrylamide, and alkylphenol disulfide oligomers. The PET composite material of this invention has high transparency, fully displaying the color of the internal low-smoke halogen-free cable, with no visual color difference. It does not exhibit significant discoloration even after long-term exposure to outdoor light, greatly expanding its outdoor applications. The material has very low water absorption and good barrier properties, thus effectively maintaining the electrical performance of the cable.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and specifically relates to a PET composite material, its preparation method, and its application. Background Technology

[0002] Low-smoke halogen-free cables have rapidly become widespread in all aspects of life due to their significant low-smoke and halogen-free characteristics. However, low-smoke halogen-free cables also have disadvantages such as being prone to scratches and having poor gloss. Long-term use not only affects their appearance but also poses certain safety hazards due to their moisture absorption.

[0003] To address this deficiency and increase product added value, the current market primarily uses extruded nylon as a cable sheath to solve the aforementioned problems. However, while nylon materials possess outstanding performance advantages such as high hardness, good mechanical properties, good wear resistance, and good processability, they also have certain drawbacks. For example, they are prone to yellowing over long-term use, affecting their appearance; they are expensive; and their hygroscopic properties affect the electrical performance of cables. These drawbacks severely limit the large-scale application of nylon materials in cables.

[0004] Therefore, it is of great significance to provide a PET composite material with high transparency, low water absorption, good weather resistance and not easy to discolor. Summary of the Invention

[0005] The present invention aims to solve one or more technical problems existing in the prior art, and at least provide a beneficial solution. Specifically, the present invention provides a PET composite material with high transparency, low water absorption, good resistance to yellowing and discoloration, and low cost.

[0006] The inventive concept of this invention: The PET composite material of this invention, by weight, comprises 70-95 parts of polyethylene terephthalate (PET), 0-15 parts of polybutylene terephthalate (PBT), 3-10 parts of toughening agent, and 0.2-1 parts of anti-crystallization agent; the anti-crystallization agent includes at least one of polyethylene glycol, polyacrylamide, and alkylphenol disulfide oligomers. This invention, by adding a toughening agent, a specific type of anti-crystallization agent, and combining it with a specific amount of polybutylene terephthalate, results in a PET composite material with high transparency, low water absorption, good resistance to yellowing, and minimal discoloration.

[0007] Therefore, a first aspect of the present invention provides a PET composite material.

[0008] Specifically, by mass parts, the raw materials for preparing the PET composite material include 70-95 parts of polyethylene terephthalate, 0-15 parts of polybutylene terephthalate, 3-10 parts of toughening agent, and 0.2-1 parts of anti-crystallization agent; the anti-crystallization agent includes at least one of polyethylene glycol, polyacrylamide, and alkylphenol disulfide oligomers.

[0009] Preferably, the intrinsic viscosity of the polyethylene terephthalate is 0.8-1.0 dl / g; for example, 0.8 dl / g, 0.9 dl / g, 1.0 dl / g, etc.

[0010] Preferably, the intrinsic viscosity of the polybutylene terephthalate is 0.6-0.8 dl / g; for example, 0.6 dl / g, 0.7 dl / g, 0.8 dl / g, etc.

[0011] Preferably, the toughening agent comprises at least one of styrene-methyl acrylate-glycidyl methacrylate copolymer, styrene-acrylonitrile-maleic anhydride copolymer, and ethylene-acrylate-glycidyl methacrylate copolymer.

[0012] More preferably, the toughening agent is a styrene-methyl acrylate-glycidyl methacrylate copolymer.

[0013] Preferably, the anti-crystallization agent is polyacrylamide.

[0014] Preferably, the raw materials for preparing the PET composite material also include at least one of antioxidants and lubricants.

[0015] Preferably, the raw materials for preparing the PET composite material further include antioxidants and lubricants; and by mass parts, the raw materials for preparing the PET composite material include 70-95 parts of polyethylene terephthalate, 0-15 parts of polybutylene terephthalate, 3-10 parts of toughening agent, 0.2-1 parts of anti-crystallization agent, 0.1-0.5 parts of antioxidant, and 0.5-1 parts of lubricant.

[0016] Preferably, the antioxidant includes at least one of hindered phenolic antioxidants and phosphite antioxidants.

[0017] Preferably, the antioxidant comprises at least one of pentaerythritol tetra(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1010) and tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168); more preferably, the antioxidant comprises antioxidant 1010 and antioxidant 168.

[0018] Preferably, the mass ratio of antioxidant 1010 to antioxidant 168 is 1:(1-2); more preferably, the mass ratio of antioxidant 1010 to antioxidant 168 is 1:2.

[0019] Preferably, the lubricant comprises at least one of pentaerythritol stearate, vinyl bis-stearamide, and zinc stearate.

[0020] More preferably, the lubricant is pentaerythritol stearate.

[0021] A second aspect of the present invention provides a method for preparing the PET composite material described in the first aspect of the present invention.

[0022] Specifically, the preparation method of the PET composite material includes the following steps: The raw materials are mixed and melt-extruded to obtain the PET composite material.

[0023] Preferably, the polyethylene terephthalate and polybutylene terephthalate are dried before mixing.

[0024] Preferably, the drying temperature is 105-115℃, and the drying time is 2-4 hours; for example, the drying temperature is 105℃, 106℃, 107℃, 108℃, 109℃, 110℃, 111℃, 112℃, 113℃, 114℃, 115℃, etc.; and the drying time is 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, etc.

[0025] Preferably, the raw materials are stirred in a mixer to complete the mixing.

[0026] Preferably, the stirring speed is 270-550 rpm and the stirring time is 2-6 min; more preferably, the stirring speed is 300-500 rpm and the stirring time is 3-5 min.

[0027] Preferably, the melt extrusion is performed using a twin-screw extruder.

[0028] Preferably, the screw speed of the twin-screw extruder is 160-550 rpm; more preferably, the screw speed of the twin-screw extruder is 180-500 rpm.

[0029] Preferably, the twin-screw extruder includes 10 temperature control zones, with temperature control zones 1-2 having a temperature of 180-260℃, temperature control zones 3-4 having a temperature of 180-260℃, temperature control zones 5-6 having a temperature of 180-260℃, temperature control zones 7-8 having a temperature of 180-260℃, and temperature control zones 9-10 having a temperature of 180-260℃.

[0030] Preferably, the twin-screw extruder is provided with two vacuum points, one located at the end of the conveying section and the beginning of the melting section, and the other located in the metering section.

[0031] A third aspect of the present invention provides a wire and cable sheath.

[0032] Specifically, the raw materials for preparing the wire and cable sheath include the PET composite material described in the first aspect of this invention.

[0033] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows: (1) By adding toughening agents, specific types of anti-crystallization agents, and combining a specific amount of polybutylene terephthalate, the present invention makes the PET composite material have high transparency, low water absorption, good resistance to yellowing and not easy to discolor. (2) The PET composite material of this invention has high transparency, which can fully present the color of the internal low-smoke halogen-free cable material, and there is no color difference in visual effect. It will not change color significantly after long-term exposure to outdoor light, which greatly expands its outdoor application. The material has a very low water absorption rate and good barrier properties, which can maintain the electrical performance of the cable well. In addition, the PET composite material is inexpensive, which can realize large-scale market application. Detailed Implementation

[0034] To enable those skilled in the art to more clearly understand the technical solutions described in this invention, the following embodiments are provided for illustration. It should be noted that the following embodiments do not constitute a limitation on the scope of protection claimed by this invention.

[0035] Unless otherwise specified, the raw materials, reagents or devices used in the following examples are available from conventional commercial sources or can be obtained by existing known methods.

[0036] The information on the relevant raw material components in this embodiment of the invention is as follows: Polyethylene terephthalate, intrinsic viscosity 0.8-1.0 dl / g, Wankai New Materials Co., Ltd. Polybutylene terephthalate, intrinsic viscosity 0.6-0.8 dl / g, Lanshan Tunhe Technology Co., Ltd. Toughening agent, hydrogenated styrene-methyl acrylate-glycidyl methacrylate copolymer, Shenyang Ketong; Anti-crystallization agent: polyacrylamide, Guangdong Bisheng Technology Co., Ltd.; magnesium phosphate: Shandong Haizhou Bioengineering Co., Ltd. Antioxidants: Antioxidant 1010, BASF; Antioxidant 168, Changzhou Giti Chemical. Lubricant: Pentaerythritol stearate, Guangzhou Jufeng Chemical Technology Co., Ltd.

[0037] The raw material composition and dosage of the PET composite materials in Examples 1-4 and Comparative Examples 1-3 of this invention are shown in Table 1.

[0038] Table 1: Raw material composition and dosage (parts by mass) of PET composite materials in Examples 1-4 and Comparative Examples 1-3

[0039] Example 1 Example 1: The raw material composition and dosage of PET composite material are shown in Table 1.

[0040] Example 1: The specific preparation method of PET composite material is as follows: (1) Dry PET resin at 110℃ for 3 hours; dry PBT resin at 110℃ for 3 hours; (2) The dried PET resin and PBT resin, toughening agent, anti-crystallization agent, antioxidant and lubricant from step (1) are added to the mixer in sequence and stirred at 400 rpm for 5 min to obtain a mixture; (3) The mixture is fed into a twin-screw extruder, the screw speed is controlled at 350 rpm, and the mixture is melt-extruded and granulated to obtain PET composite material.

[0041] The twin-screw extruder has 10 temperature control zones: zones 1-2, 3-4, 5-6, 7-8, and 9-10, all with a temperature of 220°C. The twin-screw extruder also has two vacuum pumping points, which can be activated simultaneously. The vacuum level is controlled between 0.06 and 0.08 MPa. One point is located at the end of the conveying section and the beginning of the melting section, while the other is located in the metering section.

[0042] Example 2 Example 2 The raw material composition and dosage of PET composite material are shown in Table 1.

[0043] Example 2: The preparation method of the PET composite material is the same as that in Example 1.

[0044] Example 3 Example 3 The raw material composition and dosage of PET composite material are shown in Table 1.

[0045] Example 3: The preparation method of the PET composite material is the same as that in Example 1.

[0046] Example 4 Example 4 The raw material composition and dosage of PET composite material are shown in Table 1.

[0047] Example 4: The preparation method of the PET composite material is the same as that in Example 1.

[0048] Comparative Example 1 The only difference between Comparative Example 1 and Example 2 is that magnesium phosphate is used to replace the anti-crystallization agent polyacrylamide in Example 2 in an equal amount; otherwise, they are the same as in Example 2.

[0049] Comparative Example 2 The only difference between Comparative Example 2 and Example 3 is that in Comparative Example 2, the amount of polyethylene terephthalate is 75 parts and the amount of polybutylene terephthalate is 20 parts, while the rest is the same as in Example 3.

[0050] Comparative Example 3 The only difference between Comparative Example 3 and Example 2 is that in Comparative Example 3, polyethylene terephthalate was used to replace the toughening agent hydrogenated styrene-methyl acrylate-glycidyl methacrylate copolymer in an equal amount, i.e., hydrogenated styrene-methyl acrylate-glycidyl methacrylate copolymer was not used. Otherwise, it was the same as in Example 2.

[0051] Performance testing The performance of the PET composite materials prepared in Examples 1-4 and Comparative Examples 1-3 was tested. The test items and test methods are as follows: Tensile strength: Tested in accordance with GB / T 1040.1-2025; Elongation at break: Tested according to GB / T 1040.1-2025; Tensile strength retention after aging at 120℃ for 168h: Tested according to GB / T 1040.1-2025; Elongation at break retention after aging at 120℃ / 168h: Tested according to GB / T 1040.1-2025; Bending test: The test shall be conducted in accordance with GB / T 2951.23-1994; Light transmittance: Tested according to GB / T 46828.1-2025; 1000h yellowing resistance test: The test was conducted according to ASTM D1148; Water absorption rate: Tested in accordance with GB / T 1034-2008.

[0052] The performance test results of the PET composite materials in Examples 1-4 and Comparative Examples 1-3 are shown in Table 2.

[0053] Table 2: Performance test results of PET composite materials in Examples 1-4 and Comparative Examples 1-3

[0054] As can be seen from Table 2, the PET composite material of the present invention has high transparency, good resistance to yellowing, can be used outdoors for a long time, has good softness, and low water absorption, resulting in excellent barrier properties; at the same time, it has good mechanical properties and aging resistance.

[0055] Comparative Example 1 used other anti-crystallization agents, which reduced the light transmittance of the PET composite material and made its resistance to yellowing worse than that of Example 2.

[0056] The addition of more PBT resin in Comparative Example 2 resulted in lower tensile strength. This is likely because the PBT resin acts as a toughening agent in the system, reducing the tensile strength of the material. Furthermore, the light transmittance of Comparative Example 2 was significantly lower than that of Example 3. This is because the more PBT resin added, the more it affects the light transmittance of the material. The flexibility of the PBT molecular chains makes it easier for them to arrange themselves in a regular pattern in the molten state, and its crystallization rate is about 10 times faster than PET. PBT resin crystallizes more easily, affecting the overall light transmittance of the material.

[0057] Comparative Example 3 had a lower elongation, higher material rigidity, and the highest tensile strength, resulting in high stress that caused it to fracture during the bending test.

[0058] In summary, the PET composite material of this invention has high transparency, fully showcasing the color of the internal low-smoke halogen-free cable material with no visual color difference. It does not exhibit significant discoloration even after prolonged exposure to outdoor sunlight, greatly expanding its outdoor applications. The material also has very low water absorption and excellent barrier properties, effectively maintaining the electrical performance of the cable.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A PET composite material, characterized in that, The raw materials for preparing the PET composite material, by weight, include 70-95 parts of polyethylene terephthalate, 0-15 parts of polybutylene terephthalate, 3-10 parts of toughening agent, and 0.2-1 parts of anti-crystallization agent. The anti-crystallization agent includes at least one of polyethylene glycol, polyacrylamide, and alkylphenol disulfide oligomers.

2. The PET composite material according to claim 1, characterized in that, The intrinsic viscosity of the polyethylene terephthalate is 0.8-1.0 dl / g.

3. The PET composite material according to claim 1, characterized in that, The intrinsic viscosity of the polybutylene terephthalate is 0.6-0.8 dl / g.

4. The PET composite material according to claim 1, characterized in that, The toughening agent includes at least one of styrene-methyl acrylate-glycidyl methacrylate copolymer, styrene-acrylonitrile-maleic anhydride copolymer, and ethylene-acrylate-glycidyl methacrylate copolymer.

5. The PET composite material according to any one of claims 1-4, characterized in that, The raw materials for preparing the PET composite material also include at least one of antioxidants and lubricants.

6. The PET composite material according to claim 5, characterized in that, The raw materials for preparing the PET composite material also include antioxidants and lubricants; and by mass parts, the raw materials for preparing the PET composite material include 70-95 parts of polyethylene terephthalate, 0-15 parts of polybutylene terephthalate, 3-10 parts of toughening agent, 0.2-1 parts of anti-crystallization agent, 0.1-0.5 parts of antioxidant, and 0.5-1 parts of lubricant.

7. The PET composite material according to claim 6, characterized in that, The antioxidants include at least one of hindered phenolic antioxidants and phosphite antioxidants.

8. The PET composite material according to claim 6, characterized in that, The lubricant includes at least one of pentaerythritol stearate, vinyl bis-stearamide, and zinc stearate.

9. A method for preparing the PET composite material according to any one of claims 1-8, characterized in that, The preparation method includes the following steps: The raw materials are mixed and melt-extruded to obtain the PET composite material.

10. A sheath for electrical wires and cables, characterized in that, The raw materials for preparing the wire and cable sheath include the PET composite material as described in any one of claims 1-8.

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