Anti-scaling self-cleaning PVC (polyvinyl chloride) pipe and preparation method thereof

Abstract

The invention discloses an anti-scaling self-cleaning PVC pipe and a preparation method thereof, and belongs to the technical field of plastic pipes. The pipe is prepared from the following components in parts by weight: 100 parts of polyvinyl chloride powder, 5-20 parts of a siloxane compound additive, 3-6 parts of a heat stabilizer, 0.5-4 parts of an external lubricant, 1-10 parts of chlorinated polyethylene, 5-20 parts of an anti-scaling additive, 10-50 parts of light calcium carbonate and 1-20 parts of other processing additives, the siloxane compound additive is at least two of hydrophobic silicon dioxide, polydimethylsiloxane, octamethylcyclotetrasiloxane and a ZTZLJ-40 liquid hydrophobic agent; and the other processing aids are at least one of acrylate copolymers. The hydrophobic, anti-scaling and thermal stability performances of the pipe are effectively improved, and the service life and the maintenance period of the pipe are prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic pipes, and more specifically, to an anti-fouling self-cleaning PVC pipe and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) pipes are widely used in construction, agriculture, industry and other fields due to their excellent physical properties, chemical stability and low price. However, during the use of PVC pipes, due to the impact of water flow and impurities in the water, it is easy to form scale on the inner wall of the pipe, which affects the use of the pipe and may even cause blockage, affecting the use of normal domestic water.

[0003] The current countermeasures are mostly to fill the water outlet with descaling materials, but this countermeasure still has some problems: first, it cannot prevent blockage in the pipe, which seriously affects the service life of the pipe; second, the treatment at the water outlet will cause the water flow rate to become smaller and the efficiency to decrease. In most cases, it can only meet the demand for drinking water, and cannot effectively protect the water used in daily life (such as flushing toilets, cleaning, etc.). Based on this, it is necessary to develop a scale-proof and self-cleaning pipe. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a scale-proof and self-cleaning PVC pipe and a preparation method thereof, which effectively improves the pipe's hydrophobicity, scale resistance, thermal stability and other properties, extends the pipe's service life and maintenance cycle, and improves the convenience of daily use of water delivery pipes.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: A scale-proof self-cleaning PVC pipe, which is made of the following components in parts by weight: 100 parts of polyvinyl chloride powder, 5-20 parts of silicone composite additives, 3-6 parts of heat stabilizers, 0.5-4 parts of external lubricants, 1-10 parts of chlorinated polyethylene, 5-20 parts of anti-scaling additives, 10-50 parts of light calcium carbonate, and 1-20 parts of other processing additives; the silicone composite additives are at least two of hydrophobic silica, polydimethylsiloxane, octamethylcyclotetrasiloxane, and ZTZLJ-40 liquid hydrophobic agent; and the other processing additives are at least one of acrylic copolymers.

[0006] Furthermore, the hydrophobic silica is fumed hydrophobic silica or precipitated hydrophobic silica or silane coupling agent modified silica.

[0007] Furthermore, the anti-scaling agent is at least one of hydrolyzed polymaleic anhydride, polymethyl methacrylate, and aminotrimethylene phosphoric acid.

[0008] Furthermore, the thermal stabilizer is at least one of lanthanum isopentidine, a lead salt stabilizer, a calcium zinc stabilizer, and an organic tin stabilizer.

[0009] Furthermore, the heat stabilizer is a composition of lanthanum pipecolate and CZW-802B environmentally friendly calcium zinc composite heat stabilizer.

[0010] Furthermore, the external lubricant is at least one of dioctyl phthalate, polyethylene wax, and palm wax.

[0011] Furthermore, the pipe is a straight-through pipe.

[0012] Furthermore, the pipe is a pipe with a grid, and the pipe includes a hollow pipe body and a grid-like grid connected to the inner wall of a port at one end of the pipe body.

[0013] A method for preparing an anti-fouling self-cleaning PVC pipe comprises the following steps: a. Material mixing: Weigh each component in proportion and add it into a high-speed mixer. Heat the material temperature to 105-125°C while mixing at high speed, then cool to 55°C to obtain a premix; b. Plasticizing and granulating: convey the premix to a twin-screw extruder for extrusion granulation; the screw zone temperature of the twin-screw extruder is 120-150°C, and the die section temperature is 150-160°C; c. Extrusion molding: melt-extrude the pellets obtained in step b through a twin-screw extruder, and obtain a straight-through tube after cooling and shaping; the extrusion temperature of the twin-screw extruder is 160°C-200°C, and the mold temperature is 180-210°C.

[0014] A method for preparing an anti-fouling self-cleaning PVC pipe comprises the following steps: A. Material mixing: Weigh each component in proportion and add them into a high-speed mixer. Heat the material temperature to 105-125°C while mixing at high speed, then cool to 55°C to obtain a premix; B. Plasticizing and granulating: convey the premix to a twin-screw extruder for extrusion granulation; the screw zone temperature of the twin-screw extruder is 120-150°C, and the die section temperature is 150-160°C; C. The pellets obtained in step B are injection molded by an injection molding machine, and a tube with a grid is obtained after pressure holding, cooling, and demolding; the injection molding temperature of the injection molding machine is 160-210° C., the mold temperature during injection molding is 50-80° C., the injection molding pressure is 5-8Mpa, the injection molding flow rate is 10-25mm / s, and the injection molding time is 10-15s.

[0015] The beneficial effects of the present invention are: 1. By compounding hydrophobic materials (siloxane composite additive materials), anti-scaling additives, thermal stabilizers and other modifiers with PVC substrates and combining them with granulation technology to prepare PVC pipes, the hydrophobic, anti-scaling and self-cleaning properties of the pipes are effectively improved; the grid structure design increases the contact area between water and pipes, further promoting the anti-scaling performance of the pipes; especially when ZTZLJ-40 liquid hydrophobic agent, lanthanum isopentidyl acid and CZW-802B environmentally friendly calcium-zinc composite thermal stabilizer are added for compounding, the synergistic effect between the materials can be brought into play, further improving the hydrophobic and anti-scaling performance and thermal stability.

[0016] 2. The method of the present invention has a simple process, is conducive to low-cost batch production of pipes, prolongs the service life and maintenance cycle of pipes, is more suitable for long-term buried use of pipes, and improves the convenience of daily use of water pipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional schematic diagram of a PVC pipe with a grid according to the present invention; Figure 2 It is a schematic structural diagram of the PVC pipe with a grid according to the present invention.

[0018] In the figure: a tube body 1 and a grid plate 11. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The anti-fouling self-cleaning PVC pipe of the present invention is a straight pipe or a pipe with a grid; when it is a pipe with a grid, such as Figure 1-Figure 2 As shown, the PVC pipe includes a hollow pipe body 1 and a grid-like grille connected to the inner wall of a port at one end of the pipe body 1; the grille includes a plurality of grille plates 11, which are cross-connected to form a grid-like structure, and both ends of each grille plate 11 are connected to the inner wall of the pipe body 1.

[0021] The PVC pipe material of the present invention is made of the following components in parts by weight: 100 parts of polyvinyl chloride powder (with a polymerization degree of 600-1500), 5-20 parts of a siloxane composite auxiliary agent, 3-6 parts of a heat stabilizer, 0.5-4 parts of an external lubricant, 1-10 parts of chlorinated polyethylene, 5-20 parts of an anti-scaling auxiliary agent, 10-50 parts of light calcium carbonate, and 1-20 parts of other processing auxiliary agents; the siloxane composite auxiliary agent is at least two of hydrophobic silica, polydimethylsiloxane, octamethylcyclotetrasiloxane, and a ZTZLJ-40 liquid hydrophobic agent (purchased from Shenzhen Texuan Technology Co., Ltd.); and the other processing auxiliary agent is at least one of an acrylic copolymer. Among them, the hydrophobic silica is fumed hydrophobic silica or precipitated hydrophobic silica or silane coupling agent modified silica; the thermal stabilizer is at least one of lanthanum isopipecolate, lead salt stabilizer, calcium zinc stabilizer, and organic tin stabilizer, preferably a composition of lanthanum isopipecolate and CZW-802B environmentally friendly calcium zinc composite thermal stabilizer (purchased from Hangzhou Jianli New Materials Technology Co., Ltd.) mixed in a mass ratio of 1:1-3; the external lubricant is at least one of dioctyl phthalate, polyethylene wax, and palm wax; the anti-scaling agent is at least one of hydrolyzed polymaleic anhydride, polymethyl methacrylate, and aminotri(methylene)phosphoric acid.

[0022] The anti-fouling self-cleaning PVC pipe of the present invention is prepared by the following method: a. Weigh each component in proportion and add them into a high-speed mixer. Heat the material to 105-125°C while mixing at high speed. Then cool to 55°C to obtain a premix.

[0023] b. Plasticizing and granulating: The premix is ​​conveyed to a twin-screw extruder for extrusion granulation; the screw zone temperature of the twin-screw extruder is 120-150°C, and the die section temperature is 150-160°C.

[0024] c. Extrusion molding: The pellets prepared in step b are melt-extruded and molded by a twin-screw extruder, and a straight-through tube is obtained after cooling and shaping, wherein the extrusion temperature of the twin-screw extruder is 160° C.-200° C., and the mold temperature is 180-210° C.; Alternatively, the pellets obtained in step b are injection molded by an injection molding machine, and a tube with a grid is obtained after pressure holding, cooling, and demolding. The injection molding temperature of the injection molding machine is 160-210° C., the mold temperature during injection molding is 50-80° C., the injection molding pressure is 5-8Mpa, the injection molding flow rate is 10-25mm / s, and the injection molding time is 10-15s.

[0025] The preferred embodiments are as follows: Example 1 Preparation of anti-fouling self-cleaning PVC pipe (straight pipe) a. Weigh the following components in parts by weight: 100 parts of polyvinyl chloride powder, 5 parts of siloxane composite additive (mass ratio of polydimethylsiloxane to fumed hydrophobic silica is 3:2), 5 parts of WT-302 powdered calcium-zinc composite heat stabilizer, 4 parts of dioctyl phthalate, 4 parts of chlorinated polyethylene, 5 parts of anti-scaling additive (mass ratio of hydrolyzed polymaleic anhydride to polymethyl methacrylate is 1.5:1), 15 parts of light calcium carbonate, and 2 parts of PVC processing aid ACR-401; add the components into a high-speed mixer, heat the material temperature to 115°C while mixing at high speed, and then cool to 55°C to obtain a premix.

[0026] b. The premix is ​​conveyed to a twin-screw extruder for extrusion granulation. The screw zone temperature of the twin-screw extruder is 120-150°C and the die section temperature is 150°C.

[0027] c. The pellets obtained in step b are melt-extruded and molded by a twin-screw extruder, and a straight-through tube is obtained after cooling and shaping. The barrel extrusion temperature of the twin-screw extruder is 160° C.-200° C., and the mold temperature is 200° C.

[0028] Comparative Example 1 The same premix was prepared according to step a of Example 1, and then the premix was melt-extruded and formed by a twin-screw extruder, and a straight-through tube was obtained after cooling and shaping, and the barrel extrusion temperature of the twin-screw extruder was 160° C.-200° C., and the die section temperature was 200° C. Compared with Example 1, the granulation step was omitted in this comparative example.

[0029] Comparative Example 2 The following components were weighed in parts by weight: 100 parts of polyvinyl chloride powder, 5 parts of WT-302 powdered calcium zinc composite heat stabilizer, 4 parts of dioctyl phthalate, 4 parts of chlorinated polyvinyl chloride, 15 parts of light calcium carbonate, and 2 parts of PVC processing aid ACR-401; and then a pipe was prepared according to the method of Example 1.

[0030] Example 2 Preparation of anti-fouling self-cleaning PVC pipe (pipe with grid, the axial length of the grid accounts for 1 / 4 of the total length of the pipe) a. Weigh the following components in parts by weight: 100 parts of polyvinyl chloride powder, 5 parts of siloxane composite additive (mass ratio of polydimethylsiloxane to fumed hydrophobic silica is 3:2), 5 parts of WT-302 powdered calcium-zinc composite heat stabilizer, 4 parts of dioctyl phthalate, 4 parts of chlorinated polyethylene, 5 parts of anti-scaling additive (mass ratio of hydrolyzed polymaleic anhydride to polymethyl methacrylate is 1.5:1), 15 parts of light calcium carbonate, and 2 parts of PVC processing aid ACR-401; add the components into a high-speed mixer, heat the material temperature to 115°C while mixing at high speed, and then cool to 55°C to obtain a premix.

[0031] b. The premix is ​​conveyed to a twin-screw extruder for extrusion granulation. The screw zone temperature of the twin-screw extruder is 120-150°C and the die section temperature is 150°C.

[0032] c. The pellets obtained in step b were injection molded by an injection molding machine, and a tube with a grid was obtained after pressure holding, cooling, and demolding. The injection molding temperature of the injection molding machine was 170° C., the mold temperature during injection molding was 65° C., the injection molding pressure was 6.1 MPa, the injection molding flow rate was 12 mm / s, and the injection molding time was 14 s.

[0033] Example 3

[0034] An anti-fouling self-cleaning PVC pipe (a pipe with a grid) was prepared according to the method of Example 2, except that: an equal mass of the siloxane composite auxiliary agent was replaced by a mixture of polydimethylsiloxane and ZTZLJ-40 liquid hydrophobic agent in a mass ratio of 3:2; an equal mass of the WT-302 powdered calcium zinc composite thermal stabilizer was replaced by a mixture of lanthanum isopentac acid and WT-302 powdered calcium zinc composite thermal stabilizer in a mass ratio of 1:2.

[0035] Example 4

[0036] An anti-fouling self-cleaning PVC pipe (a pipe with a grid) was prepared according to the method of Example 2, except that: the mass of the siloxane composite auxiliary agent was replaced by a mixture of polydimethylsiloxane and ZTZLJ-40 liquid hydrophobic agent in a mass ratio of 3:2; the mass of the WT-302 powdered calcium zinc composite heat stabilizer was replaced by a mixture of WT-302 powdered calcium zinc composite heat stabilizer and CZW-802B environmentally friendly calcium zinc composite heat stabilizer in a mass ratio of 1:2.

[0037] Example 5

[0038] Anti-fouling self-cleaning PVC pipes (pipes with grids) were prepared according to the method of Example 2, except that: the mass of WT-302 powdered calcium zinc composite heat stabilizer was replaced by a mixture of lanthanum isopentac acid and CZW-802B environmentally friendly calcium zinc composite heat stabilizer in a mass ratio of 1:2.

[0039] Example 6

[0040] An anti-fouling self-cleaning PVC pipe (a pipe with a grid) was prepared according to the method of Example 2, except that: the siloxane composite auxiliary agent was replaced by a mixture of polydimethylsiloxane and ZTZLJ-40 liquid hydrophobic agent in a mass ratio of 3:2; the WT-302 powdered calcium zinc composite heat stabilizer was replaced by a mixture of lanthanum isopentac acid and CZW-802B environmentally friendly calcium zinc composite heat stabilizer in a mass ratio of 1:2.

[0041] The performance tests of the pipes prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were carried out, and the test results were as follows (the method for determining the calcium carbonate content is: 1L of water containing 300mg / L calcium carbonate is passed through the pipe at an average speed of 1L / 15min, and the calcium carbonate content in the liquid after passing through the pipe is measured):

[0042] Comparing the contact angles of the pipes of Examples 1 to 6 with Comparative Example 2, it can be seen that the method of the present invention can achieve the hydrophobic effect and anti-scaling effect of the pipe. Comparing the hydrophobic performance (the larger the water contact angle, the better the hydrophobic performance) and anti-scaling effect (the lower the residual calcium carbonate content, the better the anti-scaling effect of the material) of the pipes prepared by Comparative Example 1 and Comparative Example 1, the secondary injection molding process has a certain promoting effect on the hydrophobic effect of the pipe, but has a negative effect on the release of negative ions. Comparing Example 1 and Example 2, it can be shown that the addition of the grid helps to promote the anti-scaling effect of the pipe and overcomes the negative effect of the secondary injection molding. By comparing the performance data of Examples 3 to 6, it can be seen that after compounding with ZTZLJ-40 liquid hydrophobic agent, lanthanum isopentidine acid and CZW-802B environmentally friendly calcium-zinc composite thermal stabilizer, the performance of the pipe (Example 6) is further improved. There is a synergistic effect between ZTZLJ-40 liquid hydrophobic agent, lanthanum isopentidine acid and CZW-802B environmentally friendly calcium-zinc composite thermal stabilizer, which further improves the hydrophobic and anti-scaling performance and thermal stability performance.

[0043] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. An anti-fouling self-cleaning PVC pipe, characterized in that: The pipe is made of the following components in parts by weight: 100 parts of polyvinyl chloride powder, 5-20 parts of silicone composite additives, 3-6 parts of heat stabilizers, 0.5-4 parts of external lubricants, 1-10 parts of chlorinated polyethylene, 5-20 parts of anti-scaling additives, 10-50 parts of light calcium carbonate, and 1-20 parts of other processing additives; the silicone composite additives are at least two of hydrophobic silica, polydimethylsiloxane, octamethylcyclotetrasiloxane, and ZTZLJ-40 liquid hydrophobic agent; and the other processing additives are at least one of acrylic copolymers.

2. The anti-fouling self-cleaning PVC pipe according to claim 1, characterized in that: The hydrophobic silica is gas phase hydrophobic silica or precipitated hydrophobic silica or silane coupling agent modified silica.

3. The anti-fouling self-cleaning PVC pipe according to claim 1, characterized in that: The anti-scaling agent is at least one of hydrolyzed polymaleic anhydride, polymethyl methacrylate, and aminotrimethylene phosphoric acid.

4. The anti-fouling self-cleaning PVC pipe according to claim 1, characterized in that: The thermal stabilizer is at least one of lanthanum isopentidine, a lead salt stabilizer, a calcium zinc stabilizer, and an organic tin stabilizer.

5. The anti-fouling self-cleaning PVC pipe according to claim 1, characterized in that: The heat stabilizer is a composition of lanthanum pipecolate and CZW-802B environmentally friendly calcium zinc composite heat stabilizer.

6. The anti-fouling self-cleaning PVC pipe according to claim 1, characterized in that: The external lubricant is at least one of dioctyl phthalate, polyethylene wax and palm wax.

7. The anti-fouling self-cleaning PVC pipe according to claim 1, characterized in that: The pipe is a straight-through pipe.

8. The anti-fouling self-cleaning PVC pipe according to claim 1, characterized in that: The pipe is a pipe with a grid, comprising a hollow pipe body (1) and a grid-like grid connected to the inner wall of a port at one end of the pipe body (1).

9. A method for preparing the anti-fouling self-cleaning PVC pipe according to any one of claims 1 to 7, characterized in that: The following steps are involved: a. Material mixing: Weigh each component in proportion and add it into a high-speed mixer. Heat the material temperature to 105-125°C while mixing at high speed, then cool to 55°C to obtain a premix; b. Plasticizing and granulating: convey the premix to a twin-screw extruder for extrusion granulation; the screw zone temperature of the twin-screw extruder is 120-150°C, and the die section temperature is 150-160°C; c. Extrusion molding: melt-extrude the pellets obtained in step b through a twin-screw extruder, and obtain a straight-through tube after cooling and shaping; the extrusion temperature of the twin-screw extruder is 160°C-200°C, and the mold temperature is 180-210°C.

10. A method for preparing the anti-fouling self-cleaning PVC pipe according to any one of claims 1-6 and 8, characterized in that: The following steps are involved: A. Material mixing: Weigh each component in proportion and add them into a high-speed mixer. Heat the material temperature to 105-125°C while mixing at high speed, then cool to 55°C to obtain a premix; B. Plasticizing and granulating: convey the premix to a twin-screw extruder for extrusion granulation; the screw zone temperature of the twin-screw extruder is 120-150°C, and the die section temperature is 150-160°C; C. The pellets obtained in step B are injection molded by an injection molding machine, and a tube with a grid is obtained after pressure holding, cooling, and demolding; the injection molding temperature of the injection molding machine is 160-210° C., the mold temperature during injection molding is 50-80° C., the injection molding pressure is 5-8Mpa, the injection molding flow rate is 10-25mm / s, and the injection molding time is 10-15s.

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