A CPVC silent drainage pipe and its preparation method

Abstract

The present invention discloses a CPVC silent drain pipe and a preparation method thereof, belonging to the technical field of pipe preparation; the CPVC silent drain pipe provided by the present invention can achieve good sound insulation performance, mechanical properties, weather resistance, high temperature resistance and processing performance of the product by selecting suitable raw materials for the inner layer, middle layer and outer layer and the weight percentage of the raw materials; and the preparation method provided by the present invention is simple to operate, can be prepared by one-step co-extrusion, does not require special equipment, and is conducive to practical application and production.

Description

Technical Field

[0001] The present invention belongs to the technical field of pipe manufacturing, and in particular relates to a CPVC silent drainage pipe and a preparation method thereof. Background Art

[0002] With the continuous improvement of living standards, people's requirements for living environment are getting higher and higher. Noise pollution is also receiving more and more attention, and the requirements for product quality are also getting higher and higher. Daily drainage noise is one of the main noise sources in the civil building environment, especially in high-rise buildings. The drainage noise and product lifespan seriously affect the comfort of living in the room. At present, UPVC drainage pipes are mainly used for drainage. They are widely used because of their low cost and easy installation and maintenance. However, when used in medium and high-rise buildings, they make a lot of noise during drainage, which affects living comfort. In addition, they are not resistant to high temperatures, which reduces their service life. PP silent pipes were subsequently developed. Although PP pipes are more resistant to high temperatures than PVC pipes, their sound insulation effect is average and their weather resistance is poor. Silent pipes with multi-layer coating structures are complex to process and have high costs.

[0003] CPVC has high-temperature resistance and can be used as a pipe material to solve this problem. However, its high viscosity and narrow processing range require processing temperatures exceeding its decomposition temperature, making it difficult to process, especially during the preparation of silent pipes. While existing technologies offer methods for preparing noise-reducing drainage pipes using CPVC as a base material, such as Chinese patent CN102313084B, this patent does not utilize CPVC in all layered structures. Specifically, the inner layer utilizes PVC plastic rather than CPVC. Therefore, while the resulting pipe exhibits some noise reduction properties, its heat resistance is poor. Furthermore, the patent also incorporates excessive amounts of lead salts, which can significantly harm the environment and the human body with long-term use, resulting in significant environmental pollution. Since a technical solution in which all layered structures are based on CPVC is not yet feasible, a rational formulation and processing technology are needed to produce pipes with long service life, high-temperature resistance, excellent sound insulation, and superior processing performance. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a CPVC silent drainage pipe with excellent mechanical properties, high temperature resistance, good sound insulation effect and excellent processing performance, and a preparation method thereof.

[0005] To achieve the above objectives, in a first aspect of the present invention, the present invention provides a CPVC silent drain pipe, the CPVC silent drain pipe comprising an inner layer, an intermediate layer and an outer layer;

[0006] The inner layer and outer layer include the following raw materials in parts by weight: 100 parts of CPVC, 6-10 parts of liquid rubber, 1-2 parts of oxidized polyethylene wax (OPE wax), 1-4 parts of impact-resistant ACR, 10-30 parts of light calcium carbonate, 0.01-0.5 parts of polyethylene wax (PE wax), 2-5 parts of stabilizer, 1-3 parts of processed ACR, 0-0.5 parts of stearic acid, and 0-4 parts of titanium dioxide;

[0007] The intermediate layer comprises the following raw materials in parts by weight: 100 parts of CPVC, 3-8 parts of foaming regulator, 0.2-0.8 parts of AC foaming agent, 0.2-0.8 parts of manganese oxide, 10-20 parts of light calcium carbonate, 1-2 parts of oxidized polyethylene wax, 0.01-0.5 parts of polyethylene wax, and 0-2 parts of titanium dioxide;

[0008] The foaming regulator is an acrylic ester copolymer.

[0009] The present invention provides a CPVC silent drainage pipe comprising a three-layer structure of an inner layer, a middle layer and an outer layer, wherein the raw materials of the inner layer and the outer layer are the same, and the raw materials can interact with each other, thereby improving the fluidity of the mixed components, thereby avoiding the problem that the viscosity of CPVC as a base resin is too high and is not conducive to processing; specifically, by selecting appropriate mass parts of oxidized polyethylene wax in the inner and outer layers, wherein the melting point of the oxidized polyethylene wax is above 130°C, the oxidized polyethylene wax can maintain lubricity at high temperatures, and can also withstand friction under high pressure. Further compounding with a specific mass part of polyethylene wax can effectively improve the lubricity before and after processing, and improve the processing performance of CPVC; in addition, impact-resistant ACR and liquid rubber are added to the inner and outer layers at the same time, and the two have an excellent compounding effect. In addition to being able to further cooperate with oxidized polyethylene wax and polyethylene wax to improve the fluidity of the processing process, it can also improve the impact resistance of the material, and also has an excellent improvement effect on the heat resistance and aging resistance of the material. By using an acrylic copolymer as a foaming regulator in the middle layer, combined with an AC foaming agent, the melt strength of the CPVC material can be increased, cell size can be adjusted, and the cells can be uniform and dense, thereby ensuring the mechanical properties of the resulting product. Furthermore, the introduction of manganese oxide, based on the aforementioned foaming regulator and foaming agent, can lower the decomposition temperature of the AC foaming agent, avoiding the problem of prolonged processing due to the foaming agent's decomposition temperature exceeding that of the CPVC, further ensuring a uniform and stable foaming middle layer. Overall, the CPVC silent drain pipe provided by the present invention exhibits excellent quietness, high-temperature resistance, and mechanical properties.

[0010] As a preferred embodiment of the CPVC silent drain pipe of the present invention, the inner layer and the outer layer include the following raw materials in parts by weight: 100 parts of CPVC, 7-8 parts of liquid rubber, 1.5-1.8 parts of oxidized polyethylene wax, 2-3 parts of impact-resistant ACR, 20-25 parts of light calcium carbonate, 0.2-0.3 parts of polyethylene wax, 2-5 parts of stabilizer, 1-3 parts of processed ACR, 0.2-0.4 parts of stearic acid, and 2-3 parts of titanium dioxide;

[0011] The middle layer comprises the following raw materials in parts by mass: 100 parts of CPVC, 5-6 parts of foaming regulator, 0.4-0.6 parts of AC foaming agent, 0.4-0.6 parts of manganese oxide, 15-18 parts of light calcium carbonate, 1.5-1.8 parts of oxidized polyethylene wax, 0.2-0.3 parts of polyethylene wax, and 1-2 parts of titanium dioxide.

[0012] The inventors have found that the mass fraction of the components of the raw materials in the layered structure of the silent drainage pipe has a significant impact on the comprehensive performance of the product. When the mass fraction of the raw materials in each layered structure is further selected to be within the above range, the comprehensive effect of the obtained product is even better.

[0013] As a preferred embodiment of the CPVC silent drain pipe of the present invention, the mass content of chlorine in the CPVC is 65-70%.

[0014] As a preferred embodiment of the CPVC silent drain pipe of the present invention, the intrinsic viscosity of the acrylic copolymer is 12-15 mPa·s.

[0015] The intrinsic viscosity of the acrylic copolymer is tested according to GB / T 1632.1-2008.

[0016] Preferably, the acrylic ester copolymer is selected from ultra-high molecular weight (molecular weight above 7 million) copolymers mainly composed of methyl acrylate, butyl acrylate and methyl methacrylate.

[0017] As a preferred embodiment of the CPVC silent drain pipe of the present invention, the processing ACR is a styrene raw material, and the impact-resistant ACR is a methyl methacrylate raw material.

[0018] Selecting two different types of ACR as raw materials for addition can achieve different effects respectively. Processing ACR is used as a processing aid, and impact-resistant ACR can be compounded with liquid rubber to achieve good comprehensive effects of the product.

[0019] For example, the liquid rubber may be liquid nitrile rubber, liquid butadiene rubber, liquid styrene butadiene rubber, liquid chloroprene rubber, EPDM rubber, etc.

[0020] For example, the stabilizer may be a metal soap stabilizer, a rare earth composite stabilizer, an organotin stabilizer, or the like.

[0021] Preferably, the stabilizer is a metal soap stabilizer.

[0022] As a preferred embodiment of the CPVC silent drain pipe of the present invention, in the CPVC silent drain pipe, the thickness ratio of the inner layer, the middle layer and the outer layer is inner layer: middle layer: outer layer = (20-30): (40-60): (20-30).

[0023] Preferably, in the CPVC silent drainage pipe, the thickness ratio of the inner layer, the middle layer and the outer layer is inner layer:middle layer:outer layer=25:50:25.

[0024] The inventors have found that when the thickness ratio of the layered structure of the CPVC silent drain pipe is within the range given in the present invention, it can better achieve excellent sound insulation effect, mechanical properties and high temperature resistance.

[0025] As a preferred embodiment of the CPVC silent drain pipe of the present invention, a plurality of raised spiral ribs are provided on the inner wall of the inner layer.

[0026] The introduction of the spiral ribs can better reduce noise. The spiral ribs in the present invention can be designed in any shape in the prior art.

[0027] In a second aspect of the present invention, a method for preparing a CPVC silent drain pipe is provided. The method comprises the following steps: mixing and heating the raw materials of each layer according to a proportion, followed by cooling and co-extrusion to obtain the CPVC silent drain pipe.

[0028] Since the raw materials of the present invention are used, the corresponding pipe can be prepared by extrusion in one step during the preparation process, and the preparation method is simple to operate.

[0029] As a preferred embodiment of the preparation method of the present invention, the temperature during the mixing and heating process is 100-120°C, and the temperature after cooling is 35-45°C.

[0030] As a preferred embodiment of the preparation method of the present invention, in the co-extrusion, the barrel temperatures are 185-195°C, 180-190°C, 170-180°C, 165-175°C, and 165-175°C, and the mold temperatures are 165-175°C, 170-180°C, 180-190°C, and 190-200°C.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The CPVC silent drain pipe provided by the present invention achieves excellent sound insulation, mechanical properties, high-temperature resistance, and processability by selecting appropriate raw materials and weight ratios for the inner, middle, and outer layers. Specifically, the resulting product passes drop hammer impact tests, with a noise level below 48dB and a Vicat temperature above 115°C. Furthermore, the preparation method provided by the present invention is simple to operate and can be produced through a single co-extrusion process, requiring no special equipment, making it suitable for practical production applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of the CPVC silent drain pipe prepared in Example 1:

[0034] 1-middle layer, 2-inner layer, 3-outer layer. DETAILED DESCRIPTION

[0035] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0036] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0037] CPVC: HA-58K, chlorine content of 68% by mass, Sekisui, Japan;

[0038] Liquid rubber 1: liquid nitrile rubber, SH-820, Shenghao Plastic;

[0039] Liquid rubber 2: liquid butyl rubber, SH-5WJ, Shenghao Plastic;

[0040] Solid rubber: powdered nitrile rubber, GM60, stabilized nitrile rubber;

[0041] Foaming regulator 1: acrylic copolymer, HL-200, intrinsic viscosity 15 mPa·s, Shandong Riko;

[0042] Foaming regulator 2: acrylic copolymer, HL-901, intrinsic viscosity 12 mPa·s, Shandong Riko;

[0043] Foaming regulator 3: acrylic copolymer, HL-100, intrinsic viscosity 10 mPa·s, Shandong Riko;

[0044] AC foaming agent: azodicarbonamide, commercially available;

[0045] NC foaming agent: commercially available;

[0046] OPE wax: melting point 131°C, 316A, Honeywell;

[0047] PE wax: commercially available;

[0048] Impact resistance ACR: HL-808B, Shandong Riko;

[0049] Processing ACR: HL-801, Shandong Riko;

[0050] Stabilizer: organic tin stabilizer, MTS1200, Xiong brand;

[0051] The raw materials used in the parallel experiments in the examples of the present invention and the comparative examples were consistent.

[0052] Examples 1-6 and Comparative Examples 1-8

[0053] Examples 1-6 of the present invention and comparative examples 1-8 provide a CPVC silent drain pipe, and the weight percentages of the raw materials for the inner layer, middle layer, and outer layer of the drain pipe are shown in Table 1-2;

[0054] Table 1

[0055]

[0056]

[0057] Table 2

[0058]

[0059]

[0060] The preparation method of the CPVC silent drainage pipe in Example 1 is as follows: the raw materials of each layer are added to a special mixer according to the ratio, the material is heated to 110°C at a speed of 1500 rpm, and then the material is discharged and cooled to 40°C, and then added to the extruder of the corresponding structural layer, and extruded through a co-extrusion die to obtain a CPVC pipe; during the co-extrusion, the barrel temperatures are 190°C, 185°C, 175°C, 170°C, and 170°C, respectively, and the mold temperatures are 170°C, 175°C, 185°C, and 195°C, respectively; the structural schematic diagram of the prepared pipe is shown in FIG. Figure 1 As shown; the thickness ratio of the inner layer, the middle layer and the outer layer is 25:50:25;

[0061] The preparation methods of Examples 2-6 and Comparative Examples 1-8 are consistent with that of Example 1.

[0062] Effect Examples

[0063] The effects of the CPVC silent drain pipes prepared in Examples 1-6 and Comparative Examples 1-8 are verified, specifically including the following aspects:

[0064] 1. High temperature resistance: Use the Vicat test method (refer to GB / T1633-2000 A50 method) to test the Vicat temperature of the product. The higher the Vicat temperature, the better the high temperature resistance of the product.

[0065] 2. Mechanical properties: Refer to the method in GB / T 14152-2016 to conduct drop hammer impact test to test the impact strength of the product. The larger the value, the better the mechanical properties.

[0066] 3. Quiet performance: Refer to CJ / T 312-2009 Building Drainage Pipe System Noise Test Method to test the quiet performance of the product. The lower the value, the better the quiet effect.

[0067] 4. Appearance performance: record through visual observation;

[0068] The results are shown in Table 3;

[0069] Table 3

[0070]

[0071] As can be seen from Table 3, the technical solution provided by the present invention has achieved remarkable results. The obtained product has good quiet effect, mechanical properties and high temperature resistance, wherein the Vicat temperature is above 115°C, 0 / 10 breakage in the drop weight impact test, and the noise is below 48dB. In addition, the obtained product has normal appearance and color and uniform pores.

[0072] It can be seen from Example 1 and Examples 5-6 that when the intrinsic viscosity of the foaming regulator is further selected to be 12-15 mPa·s, the overall effect of the obtained product is even better, which is reflected in lower noise;

[0073] It can be seen from Example 1 and Comparative Examples 1-2 that when no liquid rubber is added or solid rubber is used to replace the liquid rubber, not only will the processing difficulty be significantly increased during the preparation process, the extrusion pressure and temperature will increase, resulting in decomposition of the pipe material, affecting the quality of the pipe, which is reflected in the appearance of observable decomposition and discoloration, but also the impact strength of the product is significantly reduced and the noise is significantly increased. Specifically, compared with Example 1, the Vicat temperature of the product prepared in Comparative Examples 1-2 decreased by 15-16.67% and the noise increased by 26.19-30.95%. At the same time, the product prepared in Comparative Examples 1-2 broke 10 / 10 in the drop weight impact test;

[0074] As can be seen from Example 1 and Comparative Example 3, when OPE wax is not added to the inner and outer layers but is supplemented by PE wax in terms of mass, the impact strength of the obtained product decreases, with a result of 2 / 10 breaking in the drop hammer test, and the Vicat temperature also shows a downward trend. At the same time, the noise increases, increasing by 19.05% compared with Example 1, and the appearance also shows decomposition and discoloration.

[0075] It can be seen from Example 1 and Comparative Example 4 that when only processed ACR is added to the inner and outer layers, the resulting product not only has a significantly decreased impact resistance, but also exhibits a decreasing trend in Vicat temperature and an increasing trend in noise.

[0076] It can be seen from Example 1 and Comparative Example 5 that when no foaming regulator is added to the middle layer, the melt strength of the obtained product is insufficient, resulting in insufficient gas encapsulation, which is manifested in uneven cells and channeling in appearance. In addition, the high temperature resistance, impact strength and quietness of the product are significantly reduced. Compared with Example 1, the Vicat temperature in Comparative Example 5 decreased by 11.67% and the noise increased by 47.62%.

[0077] It can be seen from Example 1 and Comparative Example 6 that when manganese oxide is not added to the middle layer, the decomposition temperature of the foaming agent increases, and the process temperature cannot reach the foaming temperature, resulting in poor foaming effect, which is reflected in the appearance of fewer cells and discoloration of the cell layer. At the same time, the quiet effect of the product is also reduced. Compared with Example 1, the noise in Comparative Example 6 increased by 42.86%;

[0078] It can be seen from Example 1 and Comparative Example 7 that when the middle layer uses NC foaming agent instead of AC foaming agent, not only the cells of the obtained product are reduced and the uniformity is deteriorated, but also the impact strength and quiet effect of the product are significantly reduced. Compared with Example 1, the noise increases by 23.81%, and the result in the drop hammer test is 1 / 10 broken.

[0079] It can be seen from Example 1 and Comparative Example 8 that when OPE wax is not added to the middle layer but PE wax is used to make up the difference, the impact strength of the obtained product decreases, as shown by 5 / 10 breakage, and the soundproofing effect deteriorates, with the noise increasing by 45.24% compared to Example 1. At the same time, the appearance shows that the middle layer has decomposed and discolored, and the bubble uniformity is poor.

[0080] Finally, it should be noted that the above embodiments are intended to illustrate the technical solutions of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A CPVC silent drain pipe, characterized in that: The CPVC silent drainage pipe includes an inner layer, a middle layer and an outer layer; The inner layer and outer layer include the following raw materials in parts by weight: CPVC 100 parts, liquid rubber 6-10 parts, oxidized polyethylene wax 1-2 parts, impact-resistant ACR 1-4 parts, light calcium carbonate 10-30 parts, polyethylene wax 0.01-0.5 parts, stabilizer 2-5 parts, processed ACR 1-3 parts, stearic acid 0-0.5 parts, titanium dioxide 0-4 parts; The intermediate layer comprises the following raw materials in parts by weight: 100 parts of CPVC, 3-8 parts of foaming regulator, 0.2-0.8 parts of AC foaming agent, 0.2-0.8 parts of manganese oxide, 10-20 parts of light calcium carbonate, 1-2 parts of oxidized polyethylene wax, 0.01-0.5 parts of polyethylene wax, and 0-2 parts of titanium dioxide; The foaming regulator is an acrylic ester copolymer.

2. The CPVC silent drain pipe according to claim 1, characterized in that: The inner layer and outer layer include the following raw materials in parts by weight: CPVC 100 parts, liquid rubber 7-8 parts, oxidized polyethylene wax 1.5-1.8 parts, impact-resistant ACR 2-3 parts, light calcium carbonate 20-25 parts, polyethylene wax 0.2-0.3 parts, stabilizer 2-5 parts, processed ACR 1-3 parts, stearic acid 0.2-0.4 parts, titanium dioxide 2-3 parts; The middle layer comprises the following raw materials in parts by mass: 100 parts of CPVC, 5-6 parts of foaming regulator, 0.4-0.6 parts of AC foaming agent, 0.4-0.6 parts of manganese oxide, 15-18 parts of light calcium carbonate, 1.5-1.8 parts of oxidized polyethylene wax, 0.2-0.3 parts of polyethylene wax, and 1-2 parts of titanium dioxide.

3. The CPVC silent drain pipe according to claim 1, characterized in that: The mass content of chlorine in the CPVC is 65-70%.

4. The CPVC silent drain pipe according to claim 1, characterized in that: The intrinsic viscosity of the acrylic ester copolymer is 12-15 mPa·s.

5. The CPVC silent drain pipe according to claim 1, characterized in that: In the CPVC silent drainage pipe, the thickness ratio of the inner layer, the middle layer and the outer layer is inner layer:middle layer:outer layer=(20-30):(40-60):(20-30).

6. The CPVC silent drain pipe according to claim 1, characterized in that: A plurality of raised spiral ribs are arranged on the inner wall of the inner layer.

7. The method for preparing the CPVC silent drain pipe according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: mixing and heating the raw materials of each layer according to a proportion, followed by cooling and co-extrusion to obtain a CPVC silent drainage pipe.

8. The preparation method according to claim 7, characterized in that The temperature during the mixing and heating process is 100-120° C., and the temperature after cooling is 35-45° C.

9. The preparation method according to claim 7, characterized in that During the coextrusion, the barrel temperatures are 185-195°C, 180-190°C, 170-180°C, 165-175°C, and 165-175°C, and the mold temperatures are 165-175°C, 170-180°C, 180-190°C, and 190-200°C.

Images