Acid and alkali resistant CPVC chemical pipe and processing method thereof

Abstract

The invention provides an acid and alkali resistant CPVC chemical pipe and a processing method thereof. The chemical pipe comprises a chemical pipe body, and the chemical pipe body comprises, by weight, 90-110 parts of CPVC resin, 8-13 parts of an impact modifier, 1.5-2.5 parts of a corrosion resistant filler, 1-9 parts of a processing aid and 10-20 parts of a cross-linking agent. Wherein the anti-impact modifier comprises chlorinated polyethylene and a methyl methacrylate-butadiene-styrene copolymer, the content of the chlorinated polyethylene is smaller than that of the methyl methacrylate-butadiene-styrene copolymer, and the anti-corrosion filler comprises 1-1.5 parts of titanium dioxide and 0.5-1 part of fluorinated titanium dioxide, so that the toughness is improved; and good mechanical properties are embodied.

Description

Technical Field

[0001] The present invention relates to the field of pipe production, and in particular to an acid and alkali resistant CPVC chemical pipe and a processing method thereof. Background Art

[0002] Acid- and alkali-resistant CPVC chemical pipe, due to its excellent corrosion resistance, high temperature resistance, and mechanical properties, is widely used in various fields, particularly in the chemical industry, where it is used to transport corrosive media such as strong acids (such as sulfuric acid and hydrochloric acid), strong bases (such as sodium hydroxide), and organic solvents (such as acetone and toluene). For example, it is used to transport plating liquid in electroplating production lines or to transport high-concentration corrosive raw materials in pesticide production. The formulation of CPVC pipe is based on chlorinated polyvinyl chloride (CPVC) resin, and its chlorine content determines its acid and alkali resistance. However, if the chlorine content is too high, the mechanical properties of the chemical pipe will be reduced, especially its lack of toughness.

[0003] In view of this, those skilled in the art need to improve the current CPVC chemical pipe to overcome the above-mentioned defects. Summary of the Invention

[0004] The main purpose of the present invention is to provide an acid and alkali resistant CPVC chemical pipe and a processing method thereof, which increases toughness and exhibits good mechanical properties.

[0005] To achieve the above objectives, in a first aspect, the present invention provides an acid- and alkali-resistant CPVC chemical pipe, comprising a chemical pipe body, wherein the chemical pipe body comprises, by weight, 90-110 parts of CPVC resin, 8-13 parts of an impact modifier, 1.5-2.5 parts of a corrosion-resistant filler, 1-9 parts of a processing aid, and 10-20 parts of a cross-linking agent; wherein the impact modifier comprises chlorinated polyethylene and methyl methacrylate-butadiene-styrene copolymer, wherein the content of chlorinated polyethylene is less than that of the methyl methacrylate-butadiene-styrene copolymer; and the corrosion-resistant filler comprises 1-1.5 parts of titanium dioxide and 0.5-1 part of fluorinated titanium dioxide.

[0006] Optionally, the CPVC resin has a chlorine content of 56%-60% and a degree of polymerization of 1200-1300.

[0007] Optionally, the ratio of chlorinated polyethylene to methyl methacrylate-butadiene-styrene copolymer is 1:1.1-1.2.

[0008] Optionally, the fluorinated titanium dioxide is formed by modifying the surface of TiO2 with tridecafluorooctyltrimethoxysilane.

[0009] Optionally, the outer side of the chemical tube body is further wrapped with a protective layer.

[0010] Optionally, the protective layer is a carbon fiber protective layer wrapped around the outside of the chemical tube body, and a resin curing layer is provided on the outside of the carbon fiber protective layer.

[0011] Optionally, the processing aids include a liquid lubricant, a stabilizer, and an antioxidant.

[0012] In order to achieve the above object, in a second aspect, the present invention provides a method for processing acid and alkali resistant CPVC chemical pipe, comprising the following steps:

[0013] S1. Mix the raw materials, add CPVC resin and liquid lubricant, stir for 2-3 minutes, then add stabilizer and antioxidant, heat to 115-125°C, stir for 8-10 minutes, then add impact modifier and stir for 4-5 minutes, add corrosion-resistant filler and stir for 2-3 minutes, finally add cross-linking agent and stir for 2-3 minutes, cool to 35-40°C, and stir at 80-130 r / min for 5-8 minutes;

[0014] S2, banburying and granulation, the mixed raw materials are added to the banbury mixer for banburying treatment, the temperature is controlled at 160-170 ° C, the rotor speed is 45-50 r / min, the time is 8-10 minutes, the banburying raw materials are added to the single screw extruder for granulation, the extruder feeding section temperature is 170-175 ° C, the compression section temperature is 175-180 ° C, the homogenization section temperature is 180-185 ° C, the screw speed is 30-40 r / min, the extrusion pressure is 10-12 MPa, and the granulation particle size is 3-5 mm;

[0015] S3, extrusion molding, the flow is added to the twin-screw extruder for molding, the feeding section temperature of the extruder is 185-195 ° C, the compression section temperature is 188-198 ° C, the homogenization section temperature is 190-200 ° C, the head temperature is 190-195 ° C, the rod speed is 15-30 r / min, the melt pressure is 8-12 MPa, and the vacuum degree is 0.04-0.06 MPa;

[0016] S4, cooling and shaping, first use a vacuum sizing cooling water tank for sizing, and then use a spray cooling tank for spray cooling.

[0017] Optionally, it also includes:

[0018] S5. Spray primer on the outside of the cooled chemical tube to a thickness of 50-80 μm. After spraying, heat to 60-80°C for 15-20 minutes for pre-curing.

[0019] S6. Using a winding machine, spirally wind the carbon fiber layer around the outside of the chemical tube at a winding speed of 0.4-0.5 m / s.

[0020] S7. After spraying epoxy resin on the surface of the carbon fiber layer, resin curing treatment is performed. The volume ratio of carbon fiber to epoxy resin is 6:4. The resin curing is first pre-cured for 45-60 minutes at a pre-curing temperature of 80°C, and then the temperature is gradually increased to 110°C within 20-30 minutes, and finally the temperature is increased to 150°C for final curing. The final curing temperature is 55-75 minutes.

[0021] Optionally, the primer includes 60 parts of epoxy resin, 30 parts of polyetheramine, 5 parts of silane coupling agent, and 5 parts of fumed silica.

[0022] The present invention provides an acid- and alkali-resistant CPVC chemical pipe and a processing method thereof. Compared with the prior art, the present invention has the following beneficial effects: it has good acid and alkali resistance, and the corrosion resistance and thermal stability of the pipe are significantly improved by the addition of fluorinated titanium dioxide. It has good surface hydrophobicity, which can reduce the adhesion of corrosive liquids on the pipe surface and reduce the risk of scaling. It also works synergistically with an impact modifier (such as MBS) to form an "island structure": titanium dioxide fluoride acts as a rigid particle to enhance interfacial bonding, and MBS provides toughness, reducing the CPVC pipe's drop hammer impact breakage rate to below 5% at 0°C. Finally, a carbon fiber protective layer is provided on the outside of the chemical pipe to further increase its toughness. The carbon fiber can prevent the propagation of cracks in the CPVC matrix and disperse the impact energy. DETAILED DESCRIPTION

[0023] To help those skilled in the art better understand the present invention, the following clearly and completely describes 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 them. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the scope of protection of the present invention.

[0024] Furthermore, some of the above terms may be used to express other meanings besides indicating a position or location. For example, the term "on" may also be used to indicate a dependency or connection in certain circumstances. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0025] Additionally, the term "plurality" shall mean two or more.

[0026] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0027] An acid- and alkali-resistant CPVC chemical pipe comprises a chemical pipe body, which comprises, by weight, 90-110 parts of CPVC resin, 8-13 parts of an impact modifier, 1.5-2.5 parts of a corrosion-resistant filler, 1-9 parts of a processing aid, and 10-20 parts of a cross-linking agent; the impact modifier comprises chlorinated polyethylene and a methyl methacrylate-butadiene-styrene copolymer, wherein the chlorinated polyethylene content is less than that of the methyl methacrylate-butadiene-styrene copolymer; and the corrosion-resistant filler comprises 1-1.5 parts of titanium dioxide and 0.5-1 part of fluorinated titanium dioxide.

[0028] Among them, the processing aid includes a liquid lubricant, a stabilizer and an antioxidant. The liquid lubricant is preferably stearic acid, which can reduce the friction between molecules, and the stabilizer is selected from at least one of methyltin mercaptan and lanthanum-cerium composite rare earth oxide. The antioxidant is preferably a hindered phenol antioxidant. The crosslinking agent is preferably 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane and vinyl triethoxysilane, wherein the amount of vinyl triethoxysilane is 5-10 parts, and the amount of 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane is 10-15 parts.

[0029] The chlorine content of the CPVC resin is 56%-60%, and the degree of polymerization is 1200-1300. Such chlorine content significantly improves the acid and alkali resistance of the chemical pipe.

[0030] In addition, in the impact modifier, the ratio of chlorinated polyethylene to methyl methacrylate-butadiene-styrene copolymer is 1:1.1-1.2, wherein chlorinated polyethylene, namely CPE, CPE improves room temperature impact resistance, while methyl methacrylate-butadiene-styrene copolymer, namely MBS, improves low-temperature toughness, CPE reduces melt viscosity, and MBS enhances melt elasticity. Moreover, the cost of CPE is lower than that of MBS, which can reduce costs. The chlorine atoms of CPE and the polar groups of MBS act synergistically to form an "island structure": fluorinated titanium dioxide acts as a rigid particle to enhance interface bonding, and MBS provides toughness and enhances the tolerance of CPVC to organic solvents. Specifically, the fluorinated titanium dioxide is formed by surface modification of TiO2 with tridecafluorooctyltrimethoxysilane.

[0031] In order to further improve the impact resistance of the chemical hose, the outside of the chemical hose body is also wrapped with a protective layer. The protective layer is a carbon fiber protective layer wrapped around the outside of the chemical hose body. A resin cured layer is provided on the outside of the carbon fiber protective layer. The carbon fiber protective layer uses the high modulus of carbon fiber to prevent the expansion of cracks in the CPVC matrix and disperse the impact energy. In addition, in order to prevent poor bonding between the carbon fiber protective layer and the chemical hose body, which leads to interlayer separation, the resin cured layer is used to cure the two to improve the bonding strength between the two.

[0032] In addition, this embodiment also provides a method for processing acid and alkali resistant CPVC chemical pipes, comprising the following steps:

[0033] S1. Mix the raw materials, add CPVC resin and liquid lubricant, stir for 2-3 minutes, then add stabilizer and antioxidant, heat to 115-125°C, stir for 8-10 minutes, then add impact modifier and stir for 4-5 minutes, add corrosion-resistant filler and stir for 2-3 minutes, finally add cross-linking agent and stir for 2-3 minutes, cool to 35-40°C, and stir at 80-130 r / min for 5-8 minutes;

[0034] S2, banburying and granulation, the mixed raw materials are added to the banbury mixer for banburying treatment, the temperature is controlled at 160-170 ° C, the rotor speed is 45-50 r / min, the time is 8-10 minutes, the banburying raw materials are added to the single screw extruder for granulation, the extruder feeding section temperature is 170-175 ° C, the compression section temperature is 175-180 ° C, the homogenization section temperature is 180-185 ° C, the screw speed is 30-40 r / min, the extrusion pressure is 10-12 MPa, and the granulation particle size is 3-5 mm;

[0035] S3, extrusion molding, the flow is added to the twin-screw extruder for molding, the feeding section temperature of the extruder is 185-195 ° C, the compression section temperature is 188-198 ° C, the homogenization section temperature is 190-200 ° C, the head temperature is 190-195 ° C, the rod speed is 15-30 r / min, the melt pressure is 8-12 MPa, and the vacuum degree is 0.04-0.06 MPa;

[0036] S4, cooling and shaping, first use a vacuum sizing cooling water tank for sizing, and then use a spray cooling tank for spray cooling;

[0037] S5. Spray primer on the outside of the cooled chemical tube to a thickness of 50-80 μm. After spraying, heat to 60-80°C for 15-20 minutes for pre-curing.

[0038] S6. Using a winding machine, spirally wind the carbon fiber layer around the outside of the chemical tube at a winding speed of 0.4-0.5 m / s.

[0039] S7. After spraying epoxy resin on the surface of the carbon fiber layer, resin curing treatment is performed. The volume ratio of carbon fiber to epoxy resin is 6:4. The resin curing is first pre-cured for 45-60 minutes at a pre-curing temperature of 80°C, and then the temperature is gradually increased to 110°C within 20-30 minutes, and finally the temperature is increased to 150°C for final curing. The final curing temperature is 55-75 minutes.

[0040] The primer includes 60 parts of epoxy resin, 30 parts of polyetheramine, 5 parts of silane coupling agent and 5 parts of fumed silica.

[0041] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An acid and alkali resistant CPVC chemical pipe, characterized in that: The chemical tube body comprises, in parts by weight, 90-110 parts of CPVC resin, 8-13 parts of impact modifier, 1.5-2.5 parts of corrosion-resistant filler, 1-9 parts of processing aid, and 10-20 parts of cross-linking agent; wherein the impact modifier comprises chlorinated polyethylene and methyl methacrylate-butadiene-styrene copolymer, wherein the content of chlorinated polyethylene is less than that of methyl methacrylate-butadiene-styrene copolymer; and the corrosion-resistant filler comprises 1-1.5 parts of titanium dioxide and 0.5-1 part of fluorinated titanium dioxide.

2. The acid and alkali resistant CPVC chemical pipe according to claim 1, characterized in that: The chlorine content of the CPVC resin is 56%-60%, and the degree of polymerization is 1200-1300.

3. The acid and alkali resistant CPVC chemical pipe according to claim 1, characterized in that: The ratio of chlorinated polyethylene to methyl methacrylate-butadiene-styrene copolymer is 1:1.1-1.

2.

4. The acid and alkali resistant CPVC chemical pipe according to claim 1, characterized in that: The fluorinated titanium dioxide is formed by modifying the surface of TiO2 with tridecafluorooctyltrimethoxysilane.

5. The acid and alkali resistant CPVC chemical pipe according to claim 1, characterized in that: The outer side of the chemical tube body is also wrapped with a protective layer.

6. The acid and alkali resistant CPVC chemical pipe according to claim 5, characterized in that: The protective layer is a carbon fiber protective layer wrapped around the outside of the chemical tube body, and a resin curing layer is provided on the outside of the carbon fiber protective layer.

7. The acid and alkali resistant CPVC chemical pipe according to claim 1, characterized in that: The processing aids include liquid lubricants, stabilizers and antioxidants.

8. A method for processing acid and alkali resistant CPVC chemical pipe, characterized by: The following steps are involved: S1. Mix the raw materials, add CPVC resin and liquid lubricant, stir for 2-3 minutes, then add stabilizer and antioxidant, heat to 115-125°C, stir for 8-10 minutes, then add impact modifier and stir for 4-5 minutes, add corrosion-resistant filler and stir for 2-3 minutes, finally add cross-linking agent and stir for 2-3 minutes, cool to 35-40°C, and stir at 80-130 r / min for 5-8 minutes; S2, banburying and granulation, the mixed raw materials are added to the banbury mixer for banburying treatment, the temperature is controlled at 160-170 ° C, the rotor speed is 45-50 r / min, the time is 8-10 minutes, the banburying raw materials are added to the single screw extruder for granulation, the extruder feeding section temperature is 170-175 ° C, the compression section temperature is 175-180 ° C, the homogenization section temperature is 180-185 ° C, the screw speed is 30-40 r / min, the extrusion pressure is 10-12 MPa, and the granulation particle size is 3-5 mm; S3, extrusion molding, the flow is added to the twin-screw extruder for molding, the feeding section temperature of the extruder is 185-195 ° C, the compression section temperature is 188-198 ° C, the homogenization section temperature is 190-200 ° C, the head temperature is 190-195 ° C, the rod speed is 15-30 r / min, the melt pressure is 8-12 MPa, and the vacuum degree is 0.04-0.06 MPa; S4, cooling and shaping, first use a vacuum sizing cooling water tank for sizing, and then use a spray cooling tank for spray cooling.

9. The method for processing acid and alkali resistant CPVC chemical pipe according to claim 8, characterized in that: Also includes: S5. Spray primer on the outside of the cooled chemical tube to a thickness of 50-80 μm. After spraying, heat to 60-80°C for 15-20 minutes for pre-curing. S6. Using a winding machine, spirally wind the carbon fiber layer around the outside of the chemical tube at a winding speed of 0.4-0.5 m / s. S7. After spraying epoxy resin on the surface of the carbon fiber layer, resin curing treatment is performed. The volume ratio of carbon fiber to epoxy resin is 6:

4. The resin curing is first pre-cured for 45-60 minutes at a pre-curing temperature of 80°C, and then the temperature is gradually increased to 110°C within 20-30 minutes, and finally the temperature is increased to 150°C for final curing. The final curing temperature is 55-75 minutes.

10. The method for processing acid and alkali resistant CPVC chemical pipe according to claim 8, characterized in that: The primer includes 60 parts of epoxy resin, 30 parts of polyetheramine, 5 parts of silane coupling agent and 5 parts of fumed silica.