A liquid-resistant composite spring water pipe for a sprayer

Abstract

The present application discloses a liquid corrosion-resistant composite spring water pipe for a sprayer, which comprises an inner layer, a middle layer and an outer layer co-extruded; the inner layer is a PVC layer, and the PVC layer comprises high-polymerization-degree PVC resin and CPVC resin with a mass ratio of 100:90-110; the middle layer is an adhesive layer, and the adhesive layer comprises injection molding grade PVC powder, polyester type TPU and CPE resin with a mass ratio of 100:22-28:14-16; the outer layer is a TPU layer, and the TPU layer is a polyether type TPU layer; it has good corrosion resistance and high temperature resistance, and improves the resilience and hydrolysis resistance of the water pipe.

Description

Technical Field

[0001] The present invention relates to a liquid corrosion-resistant composite spring water pipe for a sprayer. Background Art

[0002] Since plastic materials were prepared from synthetic polyvinyl chloride in Germany in 1937, PVC pipes have been widely used in drainage, farmland, mine ventilation and other fields due to their characteristics such as cold resistance, corrosion resistance and low price.

[0003] Compared with ordinary straight pipes, telescopic water pipes such as spring water pipes have spiral telescopic performance, do not tangle or knot, are small in volume and easy to store, are easy to empty without water accumulation, and are free of assembly and misconnection. Therefore, spring water pipes have great application value in the horticultural field, such as connecting water pipes of sprayers.

[0004] Therefore, improving PVC pipes with corrosion resistance into composite spring water pipes has certain production application value. Summary of the Invention

[0005] The purpose of the present invention is to provide a liquid corrosion-resistant composite spring water pipe for a sprayer, which has good corrosion resistance and improves the resilience of the water pipe.

[0006] The above technical purpose of the present invention is achieved through the following technical solutions:

[0007] A liquid corrosion-resistant composite spring water pipe for a sprayer includes an inner layer, a middle layer and an outer layer which are co-extruded;

[0008] The inner layer is a PVC layer, and the PVC layer includes high-polymerization-degree PVC resin and CPVC resin with a mass ratio of 100:90-110;

[0009] The middle layer is an adhesive layer, and the adhesive layer includes injection molding grade PVC powder, polyester type TPU and CPE resin with a mass ratio of 100:22-28:14-16;

[0010] The outer layer is a TPU layer, and the TPU layer is a polyether type TPU layer.

[0011] By adopting the above technical solutions, the inner layer uses a PVC layer containing high-polymerization-degree PVC resin and CPVC resin, which has good corrosion resistance and high-temperature resistance; the outer layer is a TPU layer, which has good resilience as a spring water pipe, and combining it with the PVC layer can improve the spiral telescopic performance.

[0012] Common types of TPU include polyether type and polyester type. In this application, the water pipes are in long-term contact with liquid or atomized liquid. Therefore, polyether type TPU with good hydrolysis resistance and wear resistance is preferably used in this application. However, the compatibility between polyether type TPU and PVC is poor. Therefore, in this application, the outer TPU layer and the inner PVC layer are combined through the bonding layer in the middle layer. CPE in the bonding layer plays a role in dissolving with the outer polyether type TPU layer, and polyester type TPU also plays a role in dissolving with the outer polyether type TPU layer. CPE and PVC in the bonding layer play a role in dissolving with the inner PVC layer. Then, the bonding layer is extruded together with the inner and outer layers in a co-extrusion manner, and thus the outer polyether type TPU layer can be firmly connected to the inner PVC layer to obtain the liquid corrosion-resistant composite spring water pipe for the sprayer in this application.

[0013] Preferably, in the inner layer, the high-polymerization-degree PVC resin selects PVC resin DH-2500 type. The PVC layer includes PVC resin DH-2500 type, CPVC resin, the first plasticizer, oil stabilizer, high-temperature calcium-zinc stabilizer, and optical wax with a mass ratio of 100:90~110:120~150:10~13:2~4:0.3~0.5.

[0014] In the bonding layer, the injection-grade PVC powder selects SG-3-PVC type. The bonding layer includes SG-3-PVC type, polyester type TPU, CPE resin, the second plasticizer, oil stabilizer, high-temperature calcium-zinc stabilizer, and optical wax with a mass ratio of 100:22~28:14~16:60~70:5~8:1~2:0.1~0.3.

[0015] During the PVC extrusion process, the role of the stabilizer is to prevent the molecular chains of PVC resin from being damaged and degraded under the action of heat and shear, and also to prevent degradation under the action of light oxygen and heat oxygen during storage and use.

[0016] The calcium-zinc composite heat stabilizer is a composite system designed and developed based on the principle of synergistic action. The zinc salt in it inhibits the growth of the polyene chain by replacing allyl chloride to give PVC a certain stability, and its initial heat resistance is good. However, the generated ZnCl2 has a catalytic effect on the de-HCl reaction, causing the color of the sample to turn black rapidly in the later stage, with a serious "zinc burning" phenomenon. The calcium salt does not have the function of replacing allyl chloride and lacks the ability to prevent the growth of the polyene chain when used alone, and cannot effectively inhibit the initial coloring of PVC, but can endow PVC products with excellent long-term heat stability. Compared with single metal salts, the use of calcium-zinc composite heat stabilizers shows better heat stability performance.

[0017] In the processing of PVC, oil stabilizers such as epoxidized soybean oil (ESO) can be used as plasticizers and stabilizers for polyvinyl chloride. The epoxy bonds in the molecule can absorb HCl generated by the decomposition of PVC during processing, that is, it can play a certain stabilizing role and has excellent thermal stability and light stability. When used in combination with metal soaps, epoxy oils have good synergistic effects.

[0018] The optical wax used in this application is polyethylene wax. As a commonly used external lubricant, polyethylene wax can effectively reduce the frictional heat between the PVC melt and the metal surface of the processing equipment, thereby delaying the degradation process of the PVC molecular chain and improving the thermal stability of the entire material system.

[0019] In summary, by adopting the above technical solutions of this application, the thermal stability is effectively improved and the product quality is enhanced.

[0020] Preferably, the thicknesses of the inner layer, middle layer and outer layer are 0.5 - 0.8 mm, 0.1 - 0.2 mm and 2.0 - 2.5 mm respectively;

[0021] In the inner layer, the first plasticizer is TOTM, and the PVC layer includes PVC resin DH-2500 type, CPVC resin, TOTM, oil stabilizer, high-temperature calcium-zinc stabilizer and optical wax with a mass ratio of 100:100:132:12:2.8:0.4;

[0022] In the bonding layer, the second plasticizer is DOTP, and the bonding layer includes SG-3-PVC type, polyester-type TPU, CPE resin, DOTP, oil stabilizer, high-temperature calcium-zinc stabilizer and optical wax with a mass ratio of 100:25:15:66:6:1.4:0.2.

[0023] Preferably, both the inner layer and the middle layer also contain calcium carbonate;

[0024] In the inner layer, the PVC layer includes PVC resin DH-2500 type, CPVC resin, TOTM, oil stabilizer, high-temperature calcium-zinc stabilizer, optical wax and calcium carbonate with a mass ratio of 100:100:132:12:2.8:0.4:5 - 15;

[0025] In the bonding layer, the bonding layer includes SG-3-PVC type, polyester-type TPU, CPE resin, DOTP, oil stabilizer, high-temperature calcium-zinc stabilizer, optical wax and calcium carbonate with a mass ratio of 100:25:15:66:6:1.4:0.2:5 - 15.

[0026] Preferably, the calcium carbonate is heavy calcium carbonate.

[0027] Adopting the above technical solution, adding calcium carbonate can reduce production costs and improve dimensional stability. Using heavy calcium carbonate can improve dispersibility, has good binding ability with resin, reduces the possibility of internal pores generation, and improves product quality.

[0028] Preferably, the middle layer further contains carboxylated nitrile rubber powder;

[0029] In the bonding layer, the bonding layer includes SG-3-PVC type, polyester type TPU, CPE resin, DOTP, oil stabilizer, high-temperature resistant calcium-zinc stabilizer, light wax, heavy calcium carbonate, and carboxylated nitrile rubber powder with a mass ratio of 100:25:15:66:6:1.4:0.2:10:3.

[0030] Adopting the above technical solution, carboxylated nitrile rubber powder has good compatibility with PVC resin and can improve impact resistance as an elastomer.

[0031] Preferably, a liquid corrosion-resistant composite spring water pipe for a sprayer is obtained by the following method: Mix the raw materials of each layer of the inner layer, middle layer, and outer layer evenly, and use a three-layer co-extrusion die to co-extrude and compound at 170 - 180 °C, then cool and form, and cut to obtain.

[0032] The technical effects of the present invention are mainly reflected in the following aspects:

[0033] (1) The inner layer is a PVC layer, the middle layer is a bonding layer, and the outer layer is a TPU layer. The inner layer has good corrosion resistance and high-temperature resistance. The middle layer plays a role in connecting the inner PVC layer and the outer TPU layer. The outer TPU layer has good hydrolysis resistance and spring-back performance as a spring water pipe; the spring water pipe has spiral telescopic performance, does not tangle or knot, is small in volume and easy to store, and is easy to empty without water accumulation, and is more suitable for garden irrigation; in the inner PVC layer, PVC resin DH-2500 and CPVC resin have good pesticide corrosion resistance and are suitable for pesticide irrigation;

[0034] (2) The outer polyether type TPU layer is firmly connected to the inner PVC layer, has strong bonding force, and can be industrialized;

[0035] (3) Through multiple combinations, the thermal stability of PVC is improved, and its aging resistance is enhanced. Specific embodiments

[0036] Example 1: A liquid corrosion-resistant composite spring water pipe for a sprayer includes co-extruded inner layer, middle layer, and outer layer. The thicknesses of the inner layer, middle layer, and outer layer are 0.5 - 0.8 mm, 0.1 - 0.2 mm, and 2.0 - 2.5 mm respectively.

[0037] The inner layer is a PVC layer, and its raw material formula is shown in Table 1. Inner layer A is preferred.

[0038] The middle layer is an adhesive layer, and its raw material formula is shown in Table 2. Middle layer A is preferred.

[0039] The outer layer is a TPU layer, which is a polyether-based TPU layer, type 58219 purchased from Lubrizol in the United States.

[0040] Mix the raw materials of the inner layer, middle layer and outer layer evenly respectively, and use a three-layer co-extrusion die to carry out composite co-extrusion under the condition of 170-180 °C, then cool and form, and cut to obtain.

[0041] Table 1 Inner layer formula

[0042]

[0043] Table 2 Middle layer formula

[0044]

[0045] Example 2: A liquid corrosion-resistant composite spring water pipe for a sprayer. The difference from Example 1 is that the selected formula for the inner layer adds 10 parts by mass of heavy active calcium carbonate on the basis of inner layer A, and the selected formula for the middle layer adds 10 parts by mass of heavy active calcium carbonate on the basis of middle layer A; the heavy active calcium carbonate is purchased from Nanjing Xinpu Chemical Co., Ltd. with a mesh size of 1500.

[0046] Example 3: A liquid corrosion-resistant composite spring water pipe for a sprayer. The difference from Example 2 is that the selected formula for the middle layer adds 10 parts by mass of heavy active calcium carbonate and 3 parts by mass of carboxylated acrylonitrile-butadiene rubber powder (CNBRP, type XN-II purchased from Nanjing Feima High Polymer Materials Development Co., Ltd.).

[0047] Example 4: Thermal stability test

[0048] Refer to the GB2917-1982 standard test methods for the thermal stability of polyvinyl chloride - Congo red method and pH method. Using 100 parts by mass of high-polymerization-degree PVC resin (type DH-2500 purchased from Hangzhou Electrochemical New Materials Co., Ltd.), 100 parts by mass of CPVC resin (type R207 purchased from Shandong Gaoxin Chemical Co., Ltd.), and 132 parts by mass of trioctyl trimellitate as the basic formula A, change the dosage of the high-temperature resistant calcium-zinc stabilizer (type A-200P purchased from Mizusawa in Japan), and measure the static thermal decomposition time of PVC with different dosages of the high-temperature resistant calcium-zinc stabilizer at 180 °C according to the Congo red method in GB2917-1982. The test results are shown in Table 3.

[0049] As can be seen from Table 3: In the basic formulation A, as the dosage of the high-temperature resistant calcium-zinc stabilizer increases, the static thermal decomposition time of PVC first increases and then decreases. The initial increase is mainly due to the thermal stabilization effect of the high-temperature resistant calcium-zinc stabilizer, while the subsequent decrease is because the absolute value of the zinc content in the overall system also increases correspondingly, thus increasing the possibility of "zinc burning".

[0050] Table 3

[0051] Dosage of high-temperature resistant calcium-zinc stabilizer (unit: parts by mass) Static thermal decomposition time (min) 1.0 22 2.0 46 2.8 55 4.0 43

[0052] Based on the basic formulation A, an additional 2.8 parts by mass of the high-temperature resistant calcium-zinc stabilizer (A-200P purchased from Mizusawa of Japan) was added to form the basic formulation B. Under the condition of 180 °C, the static thermal decomposition time of PVC with different dosages of epoxidized soybean oil (epoxidized soybean oil purchased from Shandong Juxing) was measured by the Congo red method in GB2917-1982. The test results are shown in Table 4.

[0053] As can be seen from Table 4: In the basic formulation B, as the dosage of epoxidized soybean oil increases, the static thermal decomposition time of PVC has been increasing (almost remains unchanged after the dosage of 13.0, not shown in the table); it can be found that as the dosage of epoxidized soybean oil increases, the stability of the PVC material is correspondingly improved, and the synergistic effect of epoxidized soybean oil on the calcium-zinc stabilizer is very obvious.

[0054] Table 4

[0055]

[0056]

[0057] Based on the basic formulation B, an additional 12.0 parts by mass of epoxidized soybean oil was added to form the basic formulation C. Under the condition of 180 °C, the static thermal decomposition time of PVC with different dosages of light wax (polyethylene wax purchased from Yanshan Petrochemical) was measured by the Congo red method in GB2917-1982. The test results are shown in Table 5.

[0058] As can be seen from Table 5: In the basic formulation C, as the dosage of light wax increases, the static thermal decomposition time of PVC has been increasing (almost remains unchanged after the dosage of 0.4, not shown in the table); it can be found that as the dosage of light wax increases, the stability of the PVC material is correspondingly improved.

[0059] Table 5

[0060] Optical wax (unit: parts by mass) Static thermal decomposition time (min) 0.0 76 0.2 77 0.3 81 0.4 83 0.5 84

[0061] 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 liquid-resistant composite spring water pipe for a sprayer, characterized in that, It includes a co-extruded inner layer, middle layer and outer layer; the thicknesses of the inner layer, middle layer and outer layer are 0.5 - 0.8 mm, 0.1 - 0.2 mm and 2.0 - 2.5 mm respectively; the corrosion-resistant composite spring water pipe for a sprayer is obtained by the following method: mixing the raw materials of each layer of the inner layer, middle layer and outer layer evenly, using a three-layer co-extrusion die, co-extruding and compounding under the condition of 170 - 180 °C, cooling and forming, and cutting to obtain it; The inner layer is a PVC layer, and the PVC layer includes PVC resin DH-2500 type, CPVC resin, TOTM, oil stabilizer, high-temperature resistant calcium-zinc stabilizer, light wax and heavy active calcium carbonate with a mass ratio of 100:100:132:12:2.8:0.4:5 - 15; The middle layer is an adhesive layer, and the adhesive layer includes injection-grade PVC powder of SG-3-PVC type, polyester-type TPU, CPE resin, DOTP, oil stabilizer, high-temperature resistant calcium-zinc stabilizer, light wax, heavy active calcium carbonate, carboxyl butadiene acrylonitrile rubber powder with a mass ratio of 100:25:15:66:6:1.4:0.2:10:3; The outer layer is a TPU layer, and the TPU layer is a polyether-type TPU layer.

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