A PVC sheath for high-pressure pipes and its preparation method

Abstract

The present application provides a PVC sheath for a high-pressure pipe and a preparation method thereof. By mass parts, it comprises the following components: 100 parts of PVC resin with an average degree of polymerization of 1300, 45-50 parts of a plasticizer, 0.8-1.2 parts of a stabilizer, 0.3-1.2 parts of a lubricant, 0.15-0.25 parts of carbon black, 1.5-2.0 parts of ethylene-vinyl acetate copolymer, and 0.4-0.6 parts of glass microspheres, having the advantage of improving abrasion resistance.

Description

Technical Field

[0001] The present invention relates to a PVC sheath for a high-pressure pipe and a preparation method thereof. Background Art

[0002] The wear resistance of PVC is not as good as that of some elastomers or rubbers. However, it is inexpensive and readily available, and has relatively good comprehensive properties, so it is still widely used in products with low requirements for wear resistance. So far, there are not many reports on the wear-resistant modification research of PVC materials. The PVC high-pressure pipe used in a high-pressure cleaner is often dragged during use, resulting in the PVC sheath wrapped outside being easily worn through. Some high-grade high-pressure pipes use rubber materials or thermoplastic elastomers as the sheath, but the cost is relatively high; if ordinary PVC materials are used as the sheath, their wear resistance is poor and the service life is short. Summary of the Invention

[0003] The first object of the present invention is to provide a PVC sheath for a high-pressure pipe, which has the advantage of improving wear resistance.

[0004] The above technical object of the present invention is achieved through the following technical solutions:

[0005] A PVC sheath for a high-pressure pipe, by mass parts, comprises the following components: 100 parts of PVC resin with an average degree of polymerization of 1300, 45 - 50 parts of plasticizer, 0.8 - 1.2 parts of stabilizer, 0.3 - 1.2 parts of lubricant, 0.15 - 0.25 parts of carbon black, 1.5 - 2.0 parts of ethylene-vinyl acetate copolymer, and 0.4 - 0.6 parts of glass microspheres.

[0006] Preferably, the PVC sheath for a high-pressure pipe further comprises 0.3 - 0.5 parts of alumina.

[0007] Preferably, the carbon black is carbon black N330.

[0008] Preferably, the plasticizer is dioctyl terephthalate, the stabilizer is a calcium-zinc composite stabilizer, and the lubricant is epoxidized soybean oil.

[0009] Preferably, by mass parts, it comprises the following components: 100 parts of PVC resin with an average degree of polymerization of 1300, 48 parts of dioctyl terephthalate, 1.0 part of calcium-zinc composite stabilizer, 0.6 part of epoxidized soybean oil, 0.20 part of carbon black N330, 1.6 parts

[0010] of ethylene-vinyl acetate copolymer, and 0.5 part of glass microspheres.

[0011] Preferably, by mass parts, it comprises the following components: 100 parts of PVC resin with an average degree of polymerization of 1300, 48 parts of dioctyl terephthalate, 1.0 part of calcium-zinc composite stabilizer, 0.6 part of epoxidized soybean oil, 0.20 part of carbon black N330, 1.6 parts of

[0012] ethylene-vinyl acetate copolymer, 0.5 part of glass microspheres and 0.4 part of alumina.

[0013] The second object of the present invention is to provide a preparation method for a PVC sheath of a high-pressure pipe.

[0014] The above technical object of the present invention is achieved through the following technical solutions:

[0015] The described preparation method for a PVC sheath of a high-pressure pipe includes the following steps: mixing the raw materials according to the formula amount, mixing and granulating, and extruding and molding with an extruder to make a high-pressure pipe.

[0016] The technical effects of the present invention are mainly reflected in the following aspects:

[0017] PVC has a certain crystallization ability. As the degree of polymerization increases, the arrangement of PVC molecular chains tends to be regular and the crystallinity increases; crystallization, as the physical cross-linking point of plasticized PVC, improves the van der Waals force between PVC molecules and the hydrogen bond force within the molecules; under the action of external force, hydrogen bonds can separate and absorb external energy, improving the ability of PVC materials to resist mechanical action; using PVC resin with an average degree of polymerization of 1300 can obtain better wear resistance, and using ethylene-vinyl acetate copolymer to increase its impact resilience and thus increase its wear resistance. The combined use of ethylene-vinyl acetate copolymer and glass microspheres can further increase its wear resistance; selecting carbon black N330 with small particle size, high structure degree and large specific surface area for the reinforcement system to increase its wear resistance. Specific Embodiments

[0018] Example 1: A PVC sheath of a high-pressure pipe is obtained through the following preparation method, including the following steps: mixing the raw materials according to the formula amount, mixing and granulating, and extruding and molding with an extruder to make a high-pressure pipe.

[0019] By mass parts, the formula information is: 100 parts of PVC resin with an average degree of polymerization of 1300, 48 parts of dioctyl terephthalate, 1.0 part of calcium-zinc composite stabilizer, 0.6 part of epoxidized soybean oil, 0.20 part of carbon black N330, 1.6 parts of ethylene-vinyl acetate copolymer and 0.5 part of glass microspheres.

[0020] The PVC resin with an average degree of polymerization of 1300 was purchased from Hanwha Chemical (Ningbo) Co., Ltd. Dioctyl terephthalate was purchased from Shandong Kexing Chemical Co., Ltd. The calcium-zinc composite stabilizer was purchased from Tianjin Jinheng Blue Ocean Technology Co., Ltd. Epoxidized soybean oil was purchased from Shandong Huasheng New Materials Co., Ltd., with an epoxy value of more than 6.2. Carbon black N330 was purchased from Jinan Kasong Chemical Co., Ltd. Ethylene-vinyl acetate copolymer was purchased from DuPont of the United States, and the vinyl acetate content of the ethylene-vinyl acetate copolymer was less than 5%.

[0021] The glass microspheres were purchased from Guangzhou Yuanyuan New Materials Co., Ltd.

[0022] Example 2: A high-pressure pipe PVC sheath, which is different from Example 1 in that carbon black N550 is selected. Carbon black N550 was purchased from Jinan Kasong Chemical Co., Ltd.

[0023] Example 3: A high-pressure pipe PVC sheath, which is different from Example 1 in that, by mass fraction, the formulation information is: 100 parts of PVC resin with an average degree of polymerization of 1300, 48 parts of dioctyl terephthalate, 1.0 part of calcium-zinc composite stabilizer, 0.6 part of epoxidized soybean oil, 0.20 part of carbon black N330, 1.6 parts of ethylene-vinyl acetate copolymer, 0.5 part of glass microspheres and 0.4 part of alumina.

[0024] Abrasion resistance test

[0025] Control sample 1: A high-pressure pipe PVC sheath, which is different from Example 1 in that it does not contain 1.6 parts of ethylene-vinyl acetate copolymer and 0.5 parts of glass microspheres.

[0026] Control sample 2: A high-pressure pipe PVC sheath, which is different from Example 1 in that it does not contain 0.5 parts of glass microspheres.

[0027] Control sample 3: A high-pressure pipe PVC sheath, which is different from Example 1 in that it does not contain 1.6 parts of ethylene-vinyl acetate copolymer.

[0028] Test content: Refer to GB / T1689-2014 to determine the abrasion resistance, using the Akron abrasion tester method. Use the Akron abrasion tester, with a 15-degree opening angle, weigh and record the abrasion every 3416 revolutions, and continuously grind each sample 4 times.

[0029] The test results are shown in Table 1.

[0030] Table 1

[0031]

[0032] As can be seen from Table 1, the wear resistance of Control Samples 1-2 and Sample 1-3 is better than that of the PVC-1300 resin raw material. By comparing Control Sample 1-3 and Sample 1, it is found that the combined use of ethylene-vinyl acetate copolymer and glass beads can greatly improve the wear resistance effect.

[0033] The amount of ethylene-vinyl acetate copolymer was changed to 0, 0.5, 1.0, 1.5, 1.6, 2.0, 2.5 parts, and the rest of the information was the same as in Example 1. The wear resistance test was carried out, and the results are shown in Table 2.

[0034] Table 2

[0035]

[0036]

[0037] Table 2 shows that, under other unchanged conditions, with the increase of ethylene-vinyl acetate copolymer, the wear resistance first increases and then decreases. When the amount of ethylene-vinyl acetate copolymer added is 1.5 - 2.0 parts, the wear resistance is good, and the best is at the addition amount of 1.6 parts.

[0038] Of course, the above are only typical examples of the present invention. In addition, the present invention can also have many other specific implementation manners. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A PVC sheath for a high-pressure pipe, characterized in that By mass parts, it includes the following components: 100 parts of PVC resin with an average degree of polymerization of 1300, 48 parts of dioctyl terephthalate, 1.0 part of calcium-zinc composite stabilizer, 0.6 part of epoxy soybean oil, 0.20 part of carbon black N330, 1.6 parts of ethylene-vinyl acetate copolymer, 0.5 part of glass microspheres and 0.4 part of alumina; The described high-pressure pipe PVC sheath is obtained through the following preparation method: Mix the raw materials according to the formula amount, granulate the mixture, and extrude and form it with an extruder to make a high-pressure pipe.

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