A kind of antifreeze PVC drainage pipe and preparation method thereof

Abstract

This application discloses a freeze-resistant PVC drainage pipe and its preparation method, relating to the field of pipe materials. The freeze-resistant PVC drainage pipe comprises, based on raw materials, 100 parts by weight of PVC resin, 18-22 parts by weight of nanofiller, 7.5-8.5 parts by weight of composite toughening agent, 3-5 parts by weight of stabilizer, and 1.5-2.0 parts by weight of lubricant. The composite toughening agent comprises a styrene / acrylate / organic silicon polymer and a vinyl chloride / acrylate / vinyl acetate polymer in a weight ratio of 1:3:4. The composite toughening agent in this application utilizes a combination of styrene / acrylate / organic silicon polymer and vinyl chloride / acrylate / vinyl acetate polymer, which facilitates the production of a PVC drainage pipe suitable for use in an environment of -30 to -20°C and with good wall thickness uniformity.

Description

Technical Field

[0001] The present invention relates to the field of pipes, and in particular to a freeze-resistant PVC drainage pipe and a preparation method thereof. Background Art

[0002] When drainage pipes are used in cold areas, they often rupture due to internal water freezing, seriously affecting the normal operation of the drainage system.

[0003] Currently, attempts to prevent water from freezing inside drain pipes involve adding insulation layers to the outside of the pipes or using electrical heating. However, these methods are either limited in effectiveness or consume a lot of energy, making them difficult to implement on a large scale.

[0004] To this end, researchers have been exploring ways to improve the frost resistance of PVC drain pipes by optimizing their formulations. For example, chlorinated polyethylene or ethylene-vinyl acetate copolymers have been added to the PVC drain pipe composition to enhance its toughness. While these can improve the low-temperature resistance of PVC drain pipes to some extent, they are not suitable for use in temperatures between -30°C and -20°C. Consequently, there is a need to develop PVC drain pipes that can operate in environments between -30°C and -20°C. Summary of the Invention

[0005] In order to improve the problem of short service life of PVC drainage pipes in an environment of -30 to -20°C in the related art, the present application provides a freeze-resistant PVC drainage pipe and a preparation method thereof.

[0006] In the first aspect, the present application provides an antifreeze PVC drainage pipe adopting the following technical solution:

[0007] A freeze-resistant PVC drainage pipe comprises, based on raw materials, 100 parts by weight of PVC resin, 18-22 parts by weight of nanofiller, 7.5-8.5 parts by weight of a composite toughening agent, 3-5 parts by weight of a stabilizer, and 1.5-2.0 parts by weight of a lubricant; the composite toughening agent comprises a styrene / acrylate / organic silicon polymer and a vinyl chloride / acrylate / vinyl acetate polymer, and the weight ratio of the styrene / acrylate / organic silicon block polymer to the vinyl chloride / acrylate / vinyl acetate polymer is 1:(3-4).

[0008] When styrene / acrylate / silicone block polymers are used alone as toughening agents for PVC drain pipes, their compatibility with PVC resin is relatively poor, resulting in limited improvement in toughness. This shortens the service life of PVC drain pipes in temperatures between -30°C and -20°C. When vinyl chloride / acrylate / vinyl acetate polymers are used alone as toughening agents for PVC drain pipes, significant variations in the formed wall thickness can occur.

[0009] In this application, a frost-resistant PVC drain pipe uses a composite toughening agent consisting of a styrene / acrylate / organic silicone polymer and a vinyl chloride / acrylate / vinyl acetate polymer in a weight ratio of 1:(3-4). This composite toughening agent effectively improves the toughness of the PVC drain pipe at ultra-low temperatures, allowing it to function normally without cracking in environments ranging from -30°C to -20°C. This is because the addition of the styrene / acrylate / organic silicone polymer improves the poor fluidity of the PVC resin melt caused by the addition of the vinyl chloride / acrylate / vinyl acetate polymer, thereby achieving a PVC drain pipe that can be used in environments ranging from -30°C to -20°C and has a uniform wall thickness.

[0010] Optionally, the styrene / ethyl acrylate / silicone polymer is a polymer of styrene, ethyl acrylate and double-ended vinyl polydimethylsiloxane. Based on the raw materials, the weight ratio of styrene, ethyl acrylate and double-ended vinyl polydimethylsiloxane is (20-25): (35-40): (35-45).

[0011] In the present application, the ratio of styrene to double-ended vinyl polydimethylsiloxane is optimized in the styrene / ethyl acrylate / silicone polymer prepared by mixing styrene, ethyl acrylate, and double-ended vinyl polydimethylsiloxane in a weight ratio of (20-25): (35-40): (35-45). The styrene / ethyl acrylate / silicone polymer has good flexibility and can better improve the uniformity of the wall thickness of the PVC drainage pipe.

[0012] Optionally, the viscosity of the dual-end vinyl polydimethylsiloxane is 25-55 mPa·s.

[0013] The viscosity of the double-terminated vinyl polydimethylsiloxane used in the styrene / ethyl acrylate / silicone polymer of the present application is controlled within the range of 25-55 mPa.s, which is beneficial to further improve the wall thickness uniformity of the PVC drainage pipe.

[0014] Optionally, the preparation method of the styrene / ethyl acrylate / organic silicon polymer comprises the following steps:

[0015] Ethyl acrylate, styrene, and vinyl-terminated polydimethylsiloxane are added to N,N-dimethylformamide to obtain a mixed monomer solution; based on the raw materials, the amount of N,N-dimethylformamide used is 100-150% of the total weight of styrene, ethyl acrylate, and vinyl-terminated polydimethylsiloxane;

[0016] A first initiator is added dropwise to the mixed monomer solution, and the temperature of the mixed monomer solution is controlled to be 65-75° C., and the reaction is carried out for 6-8 hours. Then, a solid is separated and dried to obtain a styrene / ethyl acrylate / organic silicon polymer; the amount of the first initiator used is 1-1.5% of the total weight of styrene, ethyl acrylate, and double-ended vinyl polydimethylsiloxane.

[0017] In this application, preparing styrene / ethyl acrylate / silicone polymer according to the above method is beneficial to obtaining styrene / ethyl acrylate / silicone polymer with a particle size in the range of 0.1-0.5 mm and good particle size uniformity, which is beneficial to improving the antifreeze stability and wall thickness stability of different batches of PVC drainage pipes.

[0018] Optionally, the vinyl chloride / acrylate / vinyl acetate polymer is a polymer of vinyl chloride, acrylate and vinyl acetate, and the weight ratio of the vinyl chloride, acrylate and vinyl acetate is (50-55): (30-35): (10-20).

[0019] In the present application, the vinyl chloride / acrylate / vinyl acetate polymer prepared by using vinyl chloride, acrylate, and vinyl acetate in a weight ratio of (50-55): (30-35): (10-20) has excellent flexibility and is beneficial to improving the frost resistance of PVC drainage pipes.

[0020] Optionally, the vinyl chloride / acrylate / vinyl acetate polymer comprises the following steps:

[0021] Uniformly mixing sodium lauryl sulfate, OP-10, polyvinyl pyrrolidone, and water to obtain an emulsifier solution; the weight ratio of the sodium lauryl sulfate, OP-10, polyvinyl pyrrolidone to water is (1-1.5):(1-1.5):(30-50):(50-70); adding vinyl chloride, acrylate, and vinyl acetate to the emulsifier solution, stirring uniformly, adding a second initiator dropwise, controlling the temperature of the reaction system to 80-85° C., reacting for 4-6 hours, then breaking the emulsion, separating the solid, and drying the solid to obtain a vinyl chloride / acrylate / vinyl acetate polymer;

[0022] The amount of the emulsifier solution is 60-70% of the total weight of vinyl chloride, acrylate and vinyl acetate, and the amount of the second initiator is 1-2% of the total weight of vinyl chloride, acrylate and vinyl acetate.

[0023] In the present application, the above method is used to prepare vinyl chloride / acrylate / vinyl acetate polymer, which is beneficial to obtaining vinyl chloride / acrylate / vinyl acetate polymer with stable quality and is beneficial to improving the antifreeze stability of different batches of PVC drainage pipes.

[0024] Optionally, the nanofiller is at least one of nano calcium carbonate, nano magnesium oxide, and nano silicon dioxide.

[0025] Optionally, the stabilizer is antioxidant 1010 or a combination of antioxidant 1010 and antioxidant 168.

[0026] In the present application, the addition of a stabilizer can improve the processing stability of the PVC resin and prevent the problem of decomposition of the PVC resin in a high temperature environment.

[0027] Optionally, the lubricant includes PE wax and stearate, and the weight ratio of the PE wax to the stearate is (3-4):1.

[0028] In the present application, when the lubricant is a composition of PE wax and stearate in a weight ratio of (3-4):1, the uniformity of the wall thickness of the PVC drainage pipe can be further improved.

[0029] Optionally, the antifreeze PVC drainage pipe further includes at least one of a pigment and a whitening agent.

[0030] In a second aspect, the present application provides a method for preparing a freeze-resistant PVC drainage pipe using the following technical solution:

[0031] A method for preparing a freeze-resistant PVC drainage pipe comprises the following steps:

[0032] Uniformly mixing PVC resin, nanofiller, composite toughening agent, stabilizer and lubricant to obtain a premix;

[0033] The premix is ​​melt-extruded, pulled, and cooled to obtain a freeze-resistant PVC drainage pipe.

[0034] Optionally, the melt extrusion temperature of the premix is ​​190-210°C.

[0035] In summary, this application has at least the following beneficial technical effects:

[0036] (1) The composite toughening agent of the present application adopts a composition of styrene / acrylate / silicone polymer and vinyl chloride / acrylate / vinyl acetate polymer. By adding styrene / acrylate / silicone polymer, the problem of poor fluidity of the PVC resin melt produced by adding vinyl chloride / acrylate / vinyl acetate polymer is improved, which is conducive to obtaining a PVC drainage pipe that can be used in an environment of -30 to -20°C and has good wall thickness uniformity.

[0037] (2) The viscosity of the double-ended vinyl polydimethylsiloxane used in the styrene / ethyl acrylate / silicone polymer of the present application is controlled within the range of 25-55 mPa.s, which is beneficial to improving the particle size uniformity of the styrene / ethyl acrylate / silicone polymer and improving the antifreeze stability of different batches of PVC drainage pipes. DETAILED DESCRIPTION

[0038] The present application is further described in detail below in conjunction with specific experiments.

[0039] Preparation Example of Styrene / Ethyl Acrylate / Silicone Polymer

[0040] [Preparation Example 1-1]

[0041] A styrene / ethyl acrylate / organic silicon polymer comprising the following raw materials:

[0042] Styrene: 20kg;

[0043] Ethyl acrylate: 35kg;

[0044] Double-terminated vinyl polydimethylsiloxane: 45 kg; wherein the viscosity of double-terminated vinyl polydimethylsiloxane is 25 mPa.s; N,N-dimethylformamide: 100 kg;

[0045] First initiator: 1 kg; wherein the first initiator is specifically azobisisobutyronitrile.

[0046] In this preparation example, the preparation method of styrene / ethyl acrylate / organic silicon polymer includes the following steps:

[0047] Ethyl acrylate, styrene, and double-terminated vinyl polydimethylsiloxane are added to N,N-dimethylformamide to obtain a mixed monomer solution;

[0048] The first initiator was added dropwise to the mixed monomer solution, and the temperature of the mixed monomer solution was controlled to be 65° C. The mixture was reacted for 8 hours, and then the solid was separated and dried to obtain a styrene / ethyl acrylate / organic silicon polymer.

[0049] [Preparation Example 1-2]

[0050] A styrene / ethyl acrylate / organic silicon polymer comprising the following raw materials:

[0051] Styrene: 25kg;

[0052] Ethyl acrylate: 40kg;

[0053] Double-terminated vinyl polydimethylsiloxane: 35 kg; wherein the viscosity of double-terminated vinyl polydimethylsiloxane is 35 mPa.s; N,N-dimethylformamide: 150 kg;

[0054] First initiator: 1.5 kg; wherein the first initiator is specifically azobisisoheptanonitrile.

[0055] In this preparation example, the preparation method of styrene / ethyl acrylate / organic silicon polymer includes the following steps:

[0056] Ethyl acrylate, styrene, and double-terminated vinyl polydimethylsiloxane are added to N,N-dimethylformamide to obtain a mixed monomer solution;

[0057] The first initiator was added dropwise to the mixed monomer solution, and the temperature of the mixed monomer solution was controlled to be 65° C. The mixture was reacted for 8 hours, and then the solid was separated and dried to obtain a styrene / ethyl acrylate / organic silicon polymer.

[0058] [Preparation Examples 1-3]

[0059] A styrene / ethyl acrylate / organic silicon polymer, which differs from [Preparation Example 1-1] in that the raw material ratio is different.

[0060] In this preparation example, the raw material ratio of styrene / ethyl acrylate / organic silicon polymer is as follows:

[0061] Styrene: 35kg;

[0062] Ethyl acrylate: 35kg;

[0063] Double-terminated vinyl polydimethylsiloxane: 30 kg; wherein the viscosity of the double-terminated vinyl polydimethylsiloxane is 25 mPa.s; N,N-dimethylformamide: 100 kg;

[0064] First initiator: 1 kg; wherein the first initiator is specifically azobisisobutyronitrile.

[0065] Preparation Example of Vinyl Chloride / Acrylate / Vinyl Acetate Polymer

[0066] [Preparation Examples 1-4]

[0067] A styrene / ethyl acrylate / organic silicon polymer, which differs from [Preparation Example 1-1] in that: in this Preparation Example, the viscosity of the double-terminated vinyl polydimethylsiloxane used in the styrene / ethyl acrylate / organic silicon polymer is 55 mPa.s.

[0068] [Preparation Example 2-1]

[0069] A vinyl chloride / acrylate / vinyl acetate polymer comprising the following raw materials:

[0070] Vinyl chloride: 50kg;

[0071] Acrylate: 30kg;

[0072] Vinyl acetate: 20kg;

[0073] Emulsifier solution: 60 kg; wherein, as calculated by emulsifier solution, the emulsifier solution consists of 1 kg sodium lauryl sulfate, 1.5 kg OP-10, 30 kg polyvinylpyrrolidone K30 and 70 kg water;

[0074] Second initiator: 1 kg; wherein, the second initiator is sodium persulfate.

[0075] In this preparation example, the preparation method of vinyl chloride / acrylate / vinyl acetate polymer includes the following steps:

[0076] Evenly mix sodium lauryl sulfate, OP-10, polyvinyl pyrrolidone K30 and water to obtain an emulsifier solution;

[0077] Add vinyl chloride, acrylate and vinyl acetate to the emulsifier solution, stir evenly, add the second initiator dropwise, control the temperature of the reaction system to 80°C, react for 6 hours, then break the emulsion, separate the solid, and dry the solid to obtain a vinyl chloride / acrylate / vinyl acetate polymer.

[0078] [Preparation Example 2-2]

[0079] A vinyl chloride / acrylate / vinyl acetate polymer comprising the following raw materials:

[0080] Vinyl chloride: 55kg;

[0081] Acrylate: 35kg;

[0082] Vinyl acetate: 10kg;

[0083] Emulsifier solution: 70kg; wherein, as calculated by emulsifier solution, the emulsifier solution consists of 1.5kg sodium lauryl sulfate, 1kg OP-10, 50kg polyvinylpyrrolidone K30 and 50kg water;

[0084] Second initiator: 2 kg; wherein, the second initiator is potassium persulfate.

[0085] In this preparation example, the preparation method of vinyl chloride / acrylate / vinyl acetate polymer includes the following steps:

[0086] Evenly mix sodium lauryl sulfate, OP-10, polyvinyl pyrrolidone K30 and water to obtain an emulsifier solution;

[0087] Add vinyl chloride, acrylate and vinyl acetate to the emulsifier solution, stir evenly, add the second initiator dropwise, control the temperature of the reaction system to 85°C, react for 4 hours, then break the emulsion, separate the solid, and dry the solid to obtain a vinyl chloride / acrylate / vinyl acetate polymer.

[0088] [Preparation Example 2-3]

[0089] A vinyl chloride / acrylate / vinyl acetate polymer, which differs from [Preparation Example 2-1] in that the raw material ratio is different.

[0090] In this preparation example, the raw material ratio of vinyl chloride / acrylate / vinyl acetate polymer is as follows:

[0091] Vinyl chloride: 40kg;

[0092] Acrylate: 30kg;

[0093] Vinyl acetate: 30kg;

[0094] Emulsifier solution: 60 kg; wherein, as calculated by emulsifier solution, the emulsifier solution consists of 1 kg sodium lauryl sulfate, 1.5 kg OP-10, 30 kg polyvinylpyrrolidone K30 and 70 kg water;

[0095] Second initiator: 1 kg; wherein, the second initiator is sodium persulfate.

[0096] Example

[0097] [Example 1]

[0098] A freeze-resistant PVC drainage pipe, comprising the following raw materials:

[0099] PVC resin: 100kg; specifically PVC SG-5;

[0100] Nano filler: 18kg; specifically nano calcium carbonate;

[0101] Composite toughening agent: 7.5 kg; specifically comprising a styrene / acrylate / organic silicon polymer and a vinyl chloride / acrylate / vinyl acetate polymer, with the weight ratio of the styrene / acrylate / organic silicon polymer to the vinyl chloride / acrylate / vinyl acetate polymer being 1:3; wherein the styrene / acrylate / organic silicon polymer is the styrene / acrylate / organic silicon polymer prepared in [Preparation Example 1-1], and the vinyl chloride / acrylate / vinyl acetate polymer is the vinyl chloride / acrylate / vinyl acetate polymer prepared in [Preparation Example 2-1];

[0102] Stabilizer: 3 kg; specifically comprising antioxidant 1010 and antioxidant 168, with the weight ratio of antioxidant 1010 to antioxidant 168 being 2:1;

[0103] Lubricant: 1.5 kg; specifically comprising PE wax and zinc stearate, with the weight ratio of PE wax to zinc stearate being 4:1.

[0104] In this embodiment, the preparation method of the above-mentioned antifreeze PVC drainage pipe includes the following steps:

[0105] Uniformly mixing PVC resin, nanofiller, composite toughening agent, stabilizer and lubricant to obtain a premix;

[0106] The premix is ​​melt-extruded, pulled, and cooled to obtain a freeze-resistant PVC drainage pipe, and the melt-extrusion temperature is 190-200°C.

[0107] [Example 2]

[0108] A freeze-resistant PVC drainage pipe, comprising the following raw materials:

[0109] PVC resin: 100kg; specifically PVC SG-5;

[0110] Nano filler: 22kg; specifically nano calcium carbonate;

[0111] Composite toughening agent: 8.5 kg; specifically comprising a styrene / acrylate / organic silicon polymer and a vinyl chloride / acrylate / vinyl acetate polymer, with the weight ratio of the styrene / acrylate / organic silicon polymer to the vinyl chloride / acrylate / vinyl acetate polymer being 1:3; wherein the styrene / acrylate / organic silicon polymer is the styrene / acrylate / organic silicon polymer prepared in [Preparation Example 1-2], and the vinyl chloride / acrylate / vinyl acetate polymer is the vinyl chloride / acrylate / vinyl acetate polymer prepared in [Preparation Example 2-2];

[0112] Stabilizer: 5kg; specifically antioxidant 1010;

[0113] Lubricant: 2kg; specifically PE wax is used.

[0114] In this embodiment, the preparation method of the above-mentioned antifreeze PVC drainage pipe includes the following steps:

[0115] Uniformly mixing PVC resin, nanofiller, composite toughening agent, stabilizer and lubricant to obtain a premix;

[0116] The premix is ​​melt-extruded, pulled, and cooled to obtain a freeze-resistant PVC drainage pipe, and the melt-extrusion temperature is 200-210°C.

[0117] [Example 3]

[0118] A freeze-resistant PVC drainage pipe, which differs from [Example 1] in that the composite toughening agent is different.

[0119] In this embodiment, the styrene / acrylate / organic silicon polymer in the composite toughening agent is the styrene / acrylate / organic silicon polymer prepared in [Preparation Example 1-3].

[0120] [Example 4]

[0121] A freeze-resistant PVC drainage pipe, which differs from [Example 1] in that the composite toughening agent is different.

[0122] In this embodiment, the vinyl chloride / acrylate / vinyl acetate polymer in the composite toughening agent is the vinyl chloride / acrylate / vinyl acetate polymer prepared in [Preparation Example 2-3].

[0123] [Example 5]

[0124] A freeze-resistant PVC drainage pipe, which differs from [Example 1] in that the composite toughening agent is different.

[0125] In this embodiment, in the composite toughening agent, the styrene / acrylate / organic silicon polymer is the styrene / acrylate / organic silicon polymer prepared in [Preparation Example 1-3], and the vinyl chloride / acrylate / vinyl acetate polymer is the vinyl chloride / acrylate / vinyl acetate polymer prepared in [Preparation Example 2-3].

[0126] [Example 6]

[0127] A freeze-resistant PVC drainage pipe, which differs from [Example 1] in that the composite toughening agent is different.

[0128] In this embodiment, the styrene / acrylate / organic silicon polymer in the composite toughening agent is the styrene / acrylate / organic silicon polymer prepared in [Preparation Example 1-4].

[0129] Comparative Example

[0130] [Comparative Example 1]

[0131] A PVC drainage pipe, which differs from [Example 1] in that the composite toughening agent is replaced by an equal amount of styrene / acrylate / organic silicon polymer prepared in [Preparation Example 1-1].

[0132] [Comparative Example 2]

[0133] A PVC drainage pipe, which differs from [Example 1] in that the composite toughening agent is replaced by an equal amount of vinyl chloride / acrylate / vinyl acetate polymer prepared in [Preparation Example 2-1].

[0134] Performance testing

[0135] 1. Antifreeze performance: The PVC drain pipes prepared in each embodiment and comparative example were placed in a cold storage at -30°C and subjected to freeze-thaw cycle tests, with freeze-thaw cycles of 2000 and 5000 times, respectively, to observe whether cracks appeared in the PVC drain pipes.

[0136] 2. Wall Thickness Uniformity: The wall thickness of the PVC drain pipes prepared in each embodiment and comparative example was tested. 10 PVC drain pipes were randomly selected from each embodiment and comparative example for testing, and 5 points were randomly selected from each PVC drain pipe for wall thickness testing. The average wall thickness of each drain pipe was then calculated, and the difference between the maximum wall thickness and the minimum wall thickness of the PVC drain pipe in each embodiment and comparative example was calculated. A larger difference indicates worse wall thickness uniformity, and a smaller difference indicates better wall thickness uniformity.

[0137] Table 1

[0138]

[0139]

[0140] The difference between Example 1 and Comparative Examples 1-2 lies in the different toughening agents. In Comparative Example 1, when styrene / acrylate / organic silicone block polymer was used alone as a toughening agent for the PVC drain pipe, the compatibility of styrene / acrylate / organic silicone block polymer with PVC resin was relatively poor, resulting in a limited improvement in the toughness of the PVC drain pipe. The PVC drain pipe experienced less than 2,000 freeze-thaw cycles in a -30°C environment, resulting in a short service life. In Comparative Example 2, when vinyl chloride / acrylate / vinyl acetate polymer was used alone as a toughening agent for the PVC drain pipe, the difference between the maximum and minimum wall thicknesses of the PVC drain pipe increased. This is because using vinyl chloride / acrylate / vinyl acetate polymer alone as a toughening agent for PVC drain pipes can lead to poor fluidity of the PVC resin melt, resulting in large variations in the formed wall thickness of the PVC drain pipes.

[0141] The difference between Example 1 and Example 3 is that when preparing the styrene / ethyl acrylate / organic silicone polymer, the weight ratio of styrene, ethyl acrylate, and bi-terminal vinyl polydimethylsiloxane in Example 3 is not within the preferred range of (20-25):(35-40):(35-45). Combined with the data in Table 1, it can be seen that when the weight ratio of styrene, ethyl acrylate, and bi-terminal vinyl polydimethylsiloxane is not within the preferred range of (20-25):(35-40):(35-45), the number of freeze-thaw cycles of the PVC drainage pipe is less than 5,000, and the wall thickness uniformity of the drainage pipe is also reduced.

[0142] The difference between Example 1 and Example 4 is that when preparing the vinyl chloride / acrylate / vinyl acetate polymer, the weight ratio of vinyl chloride, acrylate, and vinyl acetate in Example 4 is not within the preferred range of (50-55):(30-35):(10-20). Combined with the data in Table 1, it can be seen that when the weight ratio of vinyl chloride, acrylate, and vinyl acetate is not within the preferred range of (50-55):(30-35):(10-20), the number of freeze-thaw cycles of the PVC drain pipe is less than 5,000.

[0143] The difference between Example 1 and Example 5 is that the raw material ratios of styrene / ethyl acrylate / organic silicon polymer and vinyl chloride / acrylate / vinyl acetate polymer used in Example 5 are not within the preferred range. Combined with the data in Table 1, it can be seen that when the raw material ratios of styrene / ethyl acrylate / organic silicon polymer and vinyl chloride / acrylate / vinyl acetate polymer are not within the preferred range, the number of freeze-thaw cycles of the PVC drainage pipe is less than 5000, and the wall thickness uniformity of the drainage pipe is also reduced.

[0144] The difference between Example 1 and Example 6 is that in the ethylene / ethyl acrylate / silicone polymer used in Example 6, the viscosity of the silicone polymer double-ended vinyl polydimethylsiloxane is not within the preferred range. Combined with the data in Table 1, it can be seen that when the viscosity of the silicone polymer double-ended vinyl polydimethylsiloxane is not within the preferred range, the wall thickness uniformity of the drainage pipe is also reduced.

[0145] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A freeze-resistant PVC drainage pipe, characterized by: Based on the raw materials, the invention comprises 100 parts by weight of PVC resin, 18-22 parts by weight of nanofiller, 7.5-8.5 parts by weight of composite toughening agent, 3-5 parts by weight of stabilizer and 1.5-2.0 parts by weight of lubricant; the composite toughening agent comprises styrene / acrylate / organic silicon polymer and vinyl chloride / acrylate / vinyl acetate polymer, and the weight ratio of the styrene / acrylate / organic silicon polymer to the vinyl chloride / acrylate / vinyl acetate polymer is 1:(3-4); The styrene / acrylate / organic silicone polymer is a polymer of styrene, ethyl acrylate, and double-terminated vinyl polydimethylsiloxane. Based on the raw materials, the weight ratio of styrene, ethyl acrylate, and double-terminated vinyl polydimethylsiloxane is (20-25): (35-40): (35-45); The vinyl chloride / acrylate / vinyl acetate polymer is a polymer of vinyl chloride, acrylate, and vinyl acetate, and the weight ratio of the vinyl chloride, acrylate, and vinyl acetate is (50-55): (30-35): (10-20); The viscosity of the dual-end vinyl polydimethylsiloxane is 25-35 mPa·s.

2. The antifreeze PVC drainage pipe according to claim 1, characterized in that: The preparation method of the styrene / acrylate / organic silicon polymer comprises the following steps: Ethyl acrylate, styrene, and bi-vinyl-terminated polydimethylsiloxane are added to N,N-dimethylformamide to obtain a mixed monomer solution; based on the raw materials, the amount of N,N-dimethylformamide used is 100-150% of the total weight of styrene, ethyl acrylate, and bi-vinyl-terminated polydimethylsiloxane; A first initiator is added dropwise to the mixed monomer solution, and the temperature of the mixed monomer solution is controlled to be 65-75° C. The mixture is reacted for 6-8 hours, and then a solid is separated and dried to obtain a styrene / acrylate / organic silicon polymer; the amount of the first initiator used is 1-1.5% of the total weight of styrene, ethyl acrylate, and double-terminated vinyl polydimethylsiloxane.

3. The antifreeze PVC drainage pipe according to claim 1, characterized in that: The vinyl chloride / acrylate / vinyl acetate polymer comprises the following steps: Evenly mix sodium lauryl sulfate, OP-10, polyvinyl pyrrolidone and water to obtain an emulsifier solution; the weight ratio of sodium lauryl sulfate, OP-10, polyvinyl pyrrolidone and water is (1-1.5): (1-1.5): (30-50): (50-70); Adding vinyl chloride, acrylate, and vinyl acetate to the emulsifier solution, stirring evenly, adding a second initiator dropwise, controlling the temperature of the reaction system to 80-85° C., reacting for 4-6 hours, then breaking the emulsion, separating the solid, and drying the solid to obtain a vinyl chloride / acrylate / vinyl acetate polymer; The amount of the emulsifier solution is 60-70% of the total weight of vinyl chloride, acrylate and vinyl acetate, and the amount of the second initiator is 1-2% of the total weight of vinyl chloride, acrylate and vinyl acetate.

4. The antifreeze PVC drainage pipe according to claim 1, characterized in that: The nano filler is at least one of nano calcium carbonate, nano magnesium oxide and nano silicon dioxide.

5. The antifreeze PVC drainage pipe according to claim 1, characterized in that: The stabilizer is antioxidant 1010 or a combination of antioxidant 1010 and antioxidant 168.

6. The antifreeze PVC drainage pipe according to claim 1, characterized in that: The lubricant includes PE wax and stearate, and the weight ratio of the PE wax to the stearate is (3-4):

1.

7. A method for preparing the frost-resistant PVC drainage pipe according to any one of claims 1 to 6, characterized in that: The following steps are involved: Uniformly mixing PVC resin, nanofiller, composite toughening agent, stabilizer and lubricant to obtain a premix; The premix is ​​melt-extruded, pulled, and cooled to obtain a freeze-resistant PVC drainage pipe.

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