Polypropylene random copolymer pipe and preparation method thereof

Abstract

The invention discloses a polypropylene random copolymer pipe and a preparation method thereof. The polypropylene random copolymer pipe comprises an inner layer, a middle layer and an outer layer, the inner layer is prepared from the following components in parts by weight: 100 parts of polypropylene random copolymer (PPR) and 0.1 to 1 part of nano-silver coated microcapsules; the middle layer comprises the following components in parts by weight: 100 parts of PPR and 3-7 parts of microcapsules wrapping aluminum hydroxide and silicon dioxide; and the outer layer contains PPR. The polypropylene random copolymer pipe is endowed with an antibacterial effect and a flame-retardant effect by using the microcapsules wrapping the nano-silver and the microcapsules wrapping the aluminum hydroxide and the silicon dioxide, the antibacterial effect and the flame-retardant effect are improved by controlling the dosages of the microcapsules and the aluminum hydroxide and the silicon dioxide to promote each other, and meanwhile, the two microcapsules are uniformly dispersed in the PPR, so that the antibacterial and flame-retardant effects are improved. The formation of rigid-tough balance is promoted, so that the PPR pipe is more stable, and the tensile strength and the impact strength of the PPR pipe are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and more specifically, to a polypropylene random copolymer pipe and a preparation method thereof. Background Art

[0002] With the continuous development of society, various types of plastic products have been widely used in daily life and industrial production. These plastic products have become indispensable materials in modern society due to their advantages such as light weight, low cost and easy processing. However, traditional plastic products are susceptible to bacterial erosion and fire threats during use, resulting in shortened service life and reduced safety. In particular, in the fields of drinking water pipes, industrial pipes and medical waste water treatment pipes, the antibacterial and flame retardant properties of pipes are particularly important. As an important public facility, the sanitation and safety of drinking water pipes are directly related to people's health. However, the inner wall of plastic pipes used for a long time is prone to bacteria breeding, leading to water pollution. In addition, the flammability of plastic materials makes the pipes easy to ignite in a fire, increasing the risk of fire spread. Similarly, in industrial pipes and medical waste water treatment pipes, bacterial erosion and fire hazards cannot be ignored.

[0003] Therefore, it is of great significance to develop a polypropylene random copolymer (PPR) pipe with high antibacterial effect, flame retardant effect, tensile strength and impact strength. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a polypropylene random copolymer pipe and a preparation method thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a polypropylene random copolymer pipe, comprising an inner layer, an intermediate layer, and an outer layer;

[0007] The inner layer includes the following components in parts by weight: 100 parts of polypropylene random copolymer (PPR), 0.1-1 parts of microcapsules encapsulating nanosilver;

[0008] The intermediate layer includes the following components in parts by weight: 100 parts of polypropylene random copolymer (PPR), 3-7 parts of microcapsules encapsulating aluminum hydroxide and silicon dioxide;

[0009] The outer layer comprises a polypropylene random copolymer.

[0010] The polypropylene random copolymer (PPR) pipe of the invention has high antibacterial effect, flame retardant effect, tensile strength and impact strength.

[0011] The invention endows the polypropylene random copolymer pipe with antibacterial effect and flame retardant effect by using microcapsules encapsulating nano silver and microcapsules encapsulating aluminum hydroxide and silicon dioxide, and promotes each other and improves the antibacterial effect and flame retardant effect of the polypropylene random copolymer pipe by controlling the dosage of the microcapsules encapsulating nano silver and the microcapsules encapsulating aluminum hydroxide and silicon dioxide. Meanwhile, the microcapsules encapsulating nano silver and the microcapsules encapsulating aluminum hydroxide and silicon dioxide are uniformly dispersed in the polypropylene random copolymer (PPR), so as to promote the formation of rigidity-toughness balance, make the polypropylene random copolymer pipe more stable, and thus improve the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0012] The polypropylene random copolymers commonly used in the art can be used in the present invention.

[0013] Preferably, the preparation method of the nano-silver encapsulated microcapsules is: mixing acrylic acid, nano-silver, emulsifier A, and initiator A to react to obtain nano-silver encapsulated microcapsules;

[0014] The weight ratio of the acrylic acid to the nano-silver is 1:(1-5).

[0015] More preferably, the weight ratio of the acrylic acid to the nanosilver is 1:(2-4).

[0016] The nano-silver-encapsulated microcapsule of the present invention uses nano-silver as a core material and uses acrylic acid polymer polyacrylic acid obtained by polymerizing acrylic acid as a wall material.

[0017] The invention controls the weight ratio of acrylic acid to nanosilver to stably encapsulate nanosilver with polyacrylic acid, thereby reducing or preventing leakage of nanosilver, and enabling microcapsules encapsulating nanosilver to be more evenly dispersed in polypropylene random copolymer (PPR), thereby further improving the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0018] More preferably, the average particle size of the nanosilver is 25-75 nm, specifically 50 nm.

[0019] More preferably, the weight ratio of the acrylic acid, emulsifier A, and initiator A is 1:5:(0.5-2).

[0020] More preferably, the emulsifier A is at least one of sodium dodecyl sulfate (SDS), Tween 80 (polyoxyethylene sorbitan monooleate), and nonylphenol polyoxyethylene ether.

[0021] More preferably, the initiator A is at least one of ammonium persulfate, potassium persulfate and sodium persulfate.

[0022] More preferably, the reaction temperature is 50-140° C. and the reaction time is 3-4 h.

[0023] More preferably, the reaction temperature is 60-125°C, specifically 60-100°C.

[0024] More preferably, the preparation method of the nano-silver encapsulated microcapsules is: adding acrylic acid, nano-silver, emulsifier A, and initiator A into solvent A, stirring and reacting to obtain nano-silver encapsulated microcapsules.

[0025] More preferably, the solvent A is at least one of acetone, ethanol and toluene.

[0026] More preferably, the weight ratio of the acrylic acid to the solvent A is 1:(8-15), specifically 1:10.

[0027] Preferably, the average particle size of the microcapsules encapsulating nanosilver is 1-15 μm.

[0028] More preferably, the average particle size of the microcapsules encapsulating nanosilver is 1-10 μm.

[0029] In the present invention, by controlling the average particle size of the microcapsules encapsulating nanosilver, the microcapsules encapsulating nanosilver can be made to move more easily in the polypropylene random copolymer (PPR), thereby being more evenly dispersed in the polypropylene random copolymer (PPR), thereby further improving the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0030] The present invention measures the average particle size of the microcapsules encapsulating nano-silver by using a dynamic light scattering (DLS) method under the conditions of a measuring angle of 90° and a temperature of 80°C.

[0031] Preferably, the preparation method of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is: mixing methyl methacrylate (MMA), core material B, emulsifier B, and initiator B to react to obtain microcapsules encapsulating aluminum hydroxide and silicon dioxide;

[0032] The core material B is aluminum hydroxide and silicon dioxide in a weight ratio of 1:(1-4).

[0033] More preferably, the core material B is aluminum hydroxide and silicon dioxide in a weight ratio of 1:(2-3).

[0034] The microcapsule encapsulating aluminum hydroxide and silicon dioxide of the present invention uses aluminum hydroxide and silicon dioxide as core materials and uses polymethyl methacrylate (PMMA) obtained by self-polymerization of methyl methacrylate (MMA) as wall material.

[0035] More preferably, the weight ratio of the methyl methacrylate (MMA) to the core material B is 1:(0.1-5).

[0036] More preferably, the weight ratio of the methyl methacrylate (MMA) to the core material B is 1:(1-4).

[0037] The present invention controls the weight ratio of methyl methacrylate (MMA) to core material B to stably encapsulate aluminum hydroxide and silicon dioxide with polymethyl methacrylate (PMMA), thereby reducing or preventing leakage of aluminum hydroxide and silicon dioxide, and enabling microcapsules encapsulating aluminum hydroxide and silicon dioxide to be more evenly dispersed in polypropylene random copolymer (PPR), thereby further improving the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0038] More preferably, the average particle size of the aluminum hydroxide is 10-100 nm, and the average particle size of the silicon dioxide is 25-75 nm.

[0039] More preferably, the weight ratio of methyl methacrylate (MMA), emulsifier B, and initiator B is 1:(2-5):(1.5-3), specifically 1:3:2.

[0040] More preferably, the emulsifier B is at least one of polyvinyl alcohol, polyvinyl pyrrolidone (PVP) and sodium laureth sulfate (SLES).

[0041] More preferably, the initiator B is at least one of azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO), and tert-butyl hydroperoxide (TBHP).

[0042] More preferably, the reaction temperature is 40-120° C. and the reaction time is 3-4 h.

[0043] More preferably, the reaction temperature is 50-110°C, specifically 50-95°C.

[0044] More preferably, the preparation method of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is: adding methyl methacrylate (MMA), core material B, emulsifier B, and initiator B into solvent B, stirring and reacting to obtain microcapsules encapsulating aluminum hydroxide and silicon dioxide.

[0045] More preferably, the solvent B is at least one of acetone, ethanol and toluene.

[0046] More preferably, the weight ratio of methyl methacrylate (MMA) to solvent B is 1:(7-10), specifically 1:8.

[0047] Preferably, the average particle size of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is 1-10 μm.

[0048] More preferably, the average particle size of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is 1-7 μm.

[0049] In the present invention, by controlling the average particle size of the microcapsules encapsulating aluminum hydroxide and silicon dioxide, the microcapsules encapsulating aluminum hydroxide and silicon dioxide can be made to move more easily in the polypropylene random copolymer (PPR), thereby being more evenly dispersed in the polypropylene random copolymer (PPR), thereby further improving the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0050] The present invention measures the average particle size of microcapsules encapsulating aluminum hydroxide and silicon dioxide by using a dynamic light scattering (DLS) method under the conditions of a measuring angle of 90° and a temperature of 80°C.

[0051] Preferably, the wall thickness of the polypropylene random copolymer pipe is 2-34 mm, and the outer diameter of the polypropylene random copolymer pipe is 20-200 mm.

[0052] The wall thickness of the polypropylene random copolymer pipe of the present invention refers to the sum of the inner layer thickness, the middle layer thickness and the outer layer thickness.

[0053] More preferably, in the polypropylene random copolymer pipe, the inner layer thickness accounts for 10%-40% of the polypropylene random copolymer pipe wall thickness, the middle layer thickness accounts for 36%-54% of the polypropylene random copolymer pipe wall thickness, and the outer layer thickness accounts for 24%-36% of the polypropylene random copolymer pipe wall thickness.

[0054] In a second aspect, the present invention provides a method for preparing a polypropylene random copolymer pipe, comprising the following steps:

[0055] S1. Mix the components of the inner layer to obtain an inner layer mixture;

[0056] S2. Mixing the components of the intermediate layer to obtain an intermediate layer mixture;

[0057] S3. Mix the components of the outer layer to obtain an outer layer mixture;

[0058] S4. The inner layer mixture, the middle layer mixture and the outer layer mixture are co-extruded to obtain a polypropylene random copolymer pipe.

[0059] Preferably, in step S4, the co-extrusion temperature is 180-220° C. and the pressure is 8-40 MPa.

[0060] Preferably, in step S1 and / or S2 and / or S3, the mixing speed is 20-100 rpm, and the mixing time is ≥10 min, specifically 30-60 min.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] The polypropylene random copolymer (PPR) pipe of the invention has high antibacterial effect, flame retardant effect, tensile strength and impact strength.

[0063] The invention endows the polypropylene random copolymer pipe with antibacterial effect and flame retardant effect by using microcapsules encapsulating nano silver and microcapsules encapsulating aluminum hydroxide and silicon dioxide, and promotes each other and improves the antibacterial effect and flame retardant effect of the polypropylene random copolymer pipe by controlling the dosage of the microcapsules encapsulating nano silver and the microcapsules encapsulating aluminum hydroxide and silicon dioxide. Meanwhile, the microcapsules encapsulating nano silver and the microcapsules encapsulating aluminum hydroxide and silicon dioxide are uniformly dispersed in the polypropylene random copolymer (PPR), so as to promote the formation of rigidity-toughness balance, make the polypropylene random copolymer pipe more stable, and thus improve the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe. DETAILED DESCRIPTION

[0064] 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.

[0065] The experimental methods in the following examples and comparative examples without specifying specific conditions are generally carried out according to conventional conditions in the art or according to conditions recommended by the manufacturer; the raw materials, reagents, etc. used, unless otherwise specified, are all raw materials and reagents that can be obtained from commercial channels such as conventional markets.

[0066] In each embodiment and comparative example of the present invention, the use of reagents is as follows:

[0067] Polypropylene random copolymer, 4220, China Petrochemical Corporation Guangzhou Company;

[0068] Nanosilver, average particle size 50 nm, R-S0150, Xi'an Ruixi Biotechnology Co., Ltd.;

[0069] Aluminum hydroxide, average particle size 10-20 nm, SS-AL04, Hangzhou Jikang New Materials Co., Ltd.;

[0070] Silicon dioxide, average particle size 50 nm, CY-SP50, Zhejiang Jiupeng New Materials Co., Ltd.;

[0071] The present invention measures the average particle size of microcapsules encapsulating nano silver and microcapsules encapsulating aluminum hydroxide and silicon dioxide by using a dynamic light scattering (DLS) method under the conditions of a measuring angle of 90° and a temperature of 80°C.

[0072] Example 1

[0073] This embodiment provides a polypropylene random copolymer pipe, including an inner layer, a middle layer, and an outer layer;

[0074] The inner layer includes the following components in parts by weight: 100 parts of polypropylene random copolymer (PPR), and 0.5 parts of microcapsules encapsulating nanosilver;

[0075] The intermediate layer includes the following components in parts by weight: 100 parts of polypropylene random copolymer (PPR), 5 parts of microcapsules encapsulating aluminum hydroxide and silicon dioxide;

[0076] The outer layer includes the following components in parts by weight: 100 parts of polypropylene random copolymer (PPR);

[0077] The wall thickness of the polypropylene random copolymer pipe is 3.4 mm; the outer diameter of the polypropylene random copolymer pipe is 20 mm; in the polypropylene random copolymer pipe, the inner layer thickness accounts for 25% of the wall thickness of the polypropylene random copolymer pipe, the middle layer thickness accounts for 50% of the wall thickness of the polypropylene random copolymer pipe, and the outer layer thickness accounts for 25% of the wall thickness of the polypropylene random copolymer pipe;

[0078] The preparation method of the nano-silver-encapsulated microcapsules is as follows: acrylic acid, nano-silver, emulsifier A (sodium dodecyl sulfate, SDS), and initiator A (ammonium persulfate) are added to solvent A (acetone), and the mixture is stirred at 85° C. for 3 hours to obtain nano-silver-encapsulated microcapsules;

[0079] The weight ratio of acrylic acid to nanosilver is 1:3; the weight ratio of acrylic acid, emulsifier A, and initiator A is 1:5:0.5; the weight ratio of acrylic acid to solvent A is 1:10;

[0080] The average particle size of the microcapsules encapsulating nanosilver is 5.0 μm;

[0081] The preparation method of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is as follows: methyl methacrylate (MMA), core material B (aluminum hydroxide and silicon dioxide), emulsifier B (polyvinyl alcohol), and initiator B (azobisisobutyronitrile, AIBN) are added to solvent B (ethanol), and stirred at 65° C. for 4 hours to obtain microcapsules encapsulating aluminum hydroxide and silicon dioxide;

[0082] Wherein, the core material B is aluminum hydroxide and silicon dioxide in a weight ratio of 1:2.5; the weight ratio of methyl methacrylate (MMA) to core material B is 1:2.5; the weight ratio of methyl methacrylate (MMA), emulsifier B, and initiator B is 1:3:2, and the weight ratio of methyl methacrylate to solvent B is 1:8;

[0083] The average particle size of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is 3.0 μm.

[0084] The method for preparing the above-mentioned polypropylene random copolymer pipe comprises the following steps:

[0085] S1. Mix the components of the inner layer at 24 rpm for 30 min to obtain an inner layer mixture;

[0086] S2. Mix the components of the intermediate layer at 39 rpm for 30 min to obtain an intermediate layer mixture;

[0087] S3. The components of the outer layer were mixed at 65 rpm for 30 min to obtain an outer layer mixture;

[0088] S4. The inner layer mixture, the middle layer mixture and the outer layer mixture are co-extruded at a temperature of 195° C. and a pressure of 8.2 MPa to obtain a polypropylene random copolymer pipe.

[0089] Examples 2-3 and Comparative Examples 1-2

[0090] Embodiment 2-3 and comparative example 1-2 provide different polypropylene random copolymer pipes, which differ from embodiment 1 in that the weight fractions of the microcapsules encapsulating nanosilver in the inner layer are different, and the rest are consistent with embodiment 1, as shown in the following table:

[0091] Table 1 Weight percentage of the microcapsules encapsulating nanosilver in the inner layer of Examples 1-3 and Comparative Examples 1-2

[0092] Weight of nano-silver encapsulated microcapsules Example 1 0.5 Example 2 0.1 Example 3 1.0 Comparative Example 1 2 Comparative Example 2 0

[0093] Examples 4-5 and Comparative Examples 3-4

[0094] Examples 4-5 and Comparative Examples 3-4 provide different polypropylene random copolymer pipes, which differ from Example 1 in that the weight fractions of the microcapsules encapsulating aluminum hydroxide and silicon dioxide in the middle layer are different, and the rest are consistent with Example 1, as shown in the following table:

[0095] Table 2 Weight fractions of microcapsules encapsulating aluminum hydroxide and silicon dioxide in the intermediate layer of Examples 1, 4-5 and Comparative Examples 3-4

[0096]

[0097]

[0098] Examples 6-9 and Comparative Examples 5-6

[0099] Examples 6-9 and Comparative Examples 5-6 provide different polypropylene random copolymer tubes, which differ from Example 1 in that the weight ratio of acrylic acid to nanosilver in the preparation method of the nanosilver-encapsulated microcapsules is different, and the rest is consistent with Example 1, as shown in the following table:

[0100] Table 3 Weight ratio of acrylic acid to nanosilver in Examples 1, 6-9 and Comparative Examples 5-6

[0101] Weight ratio of acrylic acid to nanosilver Example 1 1:3 Example 6 1:2 Example 7 1:4 Example 8 1:1 Example 9 1:5 Comparative Example 5 1:0 Comparative Example 6 0:1

[0102] Examples 10-12

[0103] Examples 10-12 provide different polypropylene random copolymer pipes, which differ from Example 1 in that the average particle size of the microcapsules encapsulating nanosilver is different, and the rest is consistent with Example 1, as shown in the following table:

[0104] Table 4 Average particle size of microcapsules encapsulating nanosilver in Examples 1, 10-12

[0105]

[0106] When preparing the microcapsules encapsulating nano-silver, the average particle size of the prepared microcapsules encapsulating nano-silver is controlled by controlling the reaction temperature.

[0107] Examples 13-16 and Comparative Examples 7-8

[0108] Examples 13-16 and Comparative Examples 7-8 provide different polypropylene random copolymer pipes, which differ from Example 1 in that the weight ratio of aluminum hydroxide to silicon dioxide in the preparation method of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is different, and the rest is consistent with Example 1, as shown in the following table:

[0109] Table 5 Weight ratio of aluminum hydroxide and silicon dioxide in Examples 1, 13-16 and Comparative Examples 7-8

[0110] Weight ratio of aluminum hydroxide to silicon dioxide Example 1 1:2.5 Embodiment 13 1:2 Embodiment 14 1:3 Embodiment 15 1:1 Example 16 1:4 Comparative Example 7 1:0 Comparative Example 8 0:1

[0111] Examples 17-20

[0112] Examples 17-20 provide different polypropylene random copolymer pipes, which differ from Example 1 in that the weight ratio of methyl methacrylate (MMA) to core material B in the preparation method of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is different, and the rest is consistent with Example 1, as shown in the following table:

[0113] Table 6 Weight ratio of methyl methacrylate to core material B in Examples 1, 17-20

[0114] Weight ratio of methyl methacrylate to core material B Example 1 1:2.5 Embodiment 17 1:1 Embodiment 18 1:4 Embodiment 19 1:0.1 Embodiment 20 1:5

[0115] Examples 21-23

[0116] Examples 21-23 provide different polypropylene random copolymer pipes, which differ from Example 1 in that the average particle sizes of the microcapsules encapsulating aluminum hydroxide and silicon dioxide are different, and the rest are consistent with Example 1, as shown in the following table:

[0117] Table 7 Average particle size of microcapsules encapsulating aluminum hydroxide and silicon dioxide in Examples 1, 21-23

[0118]

[0119] When preparing the average particle size of microcapsules encapsulating aluminum hydroxide and silicon dioxide, the average particle size of the prepared microcapsules encapsulating aluminum hydroxide and silicon dioxide is controlled by controlling the reaction temperature.

[0120] Embodiment 24

[0121] This embodiment provides a different polypropylene random copolymer tube. The difference between this embodiment and embodiment 1 is that styrene is used instead of acrylic acid, a monomer of the wall material of the microcapsules encapsulating nanosilver, and the rest is consistent with embodiment 1.

[0122] Embodiment 25

[0123] This embodiment provides a different polypropylene random copolymer pipe. The difference between this embodiment and embodiment 1 is that styrene is used instead of methyl methacrylate, the wall material monomer of the microcapsule encapsulating aluminum hydroxide and silicon dioxide. The rest is consistent with embodiment 1.

[0124] Performance Testing

[0125] The following performance tests were performed on the polypropylene random copolymer pipes of the embodiments and comparative examples:

[0126] (1) Antibacterial test

[0127] According to the JC / T939-2004 standard, Staphylococcus aureus ATCC6538 and Escherichia coli 8099 were used as the test bacteria, and the bacterial solution was applied on an area of ​​16 cm 2 , the polypropylene random copolymer pipe was tested for antibacterial effect, and the average antibacterial rate of the two tested bacteria was taken as the final antibacterial rate data;

[0128] (2) Flame retardant test

[0129] According to the UL94 standard, the sample size is 125±5mm long × 13±0.5mm wide. The flame retardant test is carried out on the polypropylene random copolymer pipe, and the flame retardant level is recorded; the flame retardant levels from low to high are UL94HB, UL94V-2, UL94V-1, UL94V-0, UL94-5V;

[0130] (3) Tensile strength test

[0131] According to GB / T 1040.2-2006 standard, at 23°C and 50% relative humidity, 1A type specimens were used to test the tensile strength of polypropylene random copolymer pipes.

[0132] (4) Impact strength test

[0133] According to GB / T 1043.1-2008 standard, the impact strength test of polypropylene random copolymer pipe was carried out at 23℃ and 50% relative humidity;

[0134] The experimental results are shown in the following table:

[0135] Table 8 Performance test results of polybutene pipes in various embodiments and comparative examples

[0136]

[0137]

[0138] It can be seen from Table 8 that the polypropylene random copolymer (PPR) pipe of the present invention has high antibacterial effect, flame retardant effect, tensile strength and impact strength.

[0139] The invention endows the polypropylene random copolymer pipe with antibacterial effect and flame retardant effect by using microcapsules encapsulating nano silver and microcapsules encapsulating aluminum hydroxide and silicon dioxide, and promotes each other and improves the antibacterial effect and flame retardant effect of the polypropylene random copolymer pipe by controlling the dosage of the microcapsules encapsulating nano silver and the microcapsules encapsulating aluminum hydroxide and silicon dioxide. Meanwhile, the microcapsules encapsulating nano silver and the microcapsules encapsulating aluminum hydroxide and silicon dioxide are uniformly dispersed in the polypropylene random copolymer (PPR), so as to promote the formation of rigidity-toughness balance, make the polypropylene random copolymer pipe more stable, and thus improve the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0140] By comparing Examples 1, 6-9 and Comparative Examples 5-6, it can be seen that the present invention controls the weight ratio of acrylic acid to nanosilver to stably encapsulate nanosilver with polyacrylic acid, reduce or prevent nanosilver leakage, and enable the microcapsules encapsulating nanosilver to be better and more evenly dispersed in the polypropylene random copolymer (PPR), thereby further improving the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0141] By comparing Examples 1 and 10-12, it can be seen that in the present invention, by controlling the average particle size of the microcapsules encapsulating nanosilver, the microcapsules encapsulating nanosilver can be made to move more easily in the polypropylene random copolymer (PPR), thereby being more evenly dispersed in the polypropylene random copolymer (PPR), thereby further improving the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0142] By comparing Examples 1 and 17-20, it can be seen that the present invention controls the weight ratio of methyl methacrylate (MMA) to core material B to stably encapsulate aluminum hydroxide and silicon dioxide with polymethyl methacrylate (PMMA), thereby reducing or preventing the leakage of aluminum hydroxide and silicon dioxide, and allowing the microcapsules encapsulating aluminum hydroxide and silicon dioxide to be better and more evenly dispersed in the polypropylene random copolymer (PPR), thereby further improving the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0143] By comparing Examples 1 and 21-23, it can be seen that in the present invention, by controlling the average particle size of the microcapsules encapsulating aluminum hydroxide and silicon dioxide, the microcapsules encapsulating aluminum hydroxide and silicon dioxide can be made to move more easily in the polypropylene random copolymer (PPR), thereby being more evenly dispersed in the polypropylene random copolymer (PPR), thereby further improving the tensile strength and impact strength of the polypropylene random copolymer (PPR) pipe.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution 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 the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A polypropylene random copolymer pipe, characterized in that: Including inner layer, middle layer and outer layer; The inner layer includes the following components in parts by weight: 100 parts of polypropylene random copolymer and 0.1-1 parts of microcapsules encapsulating nanosilver; The intermediate layer includes the following components in parts by weight: 100 parts of polypropylene random copolymer, 3-7 parts of microcapsules encapsulating aluminum hydroxide and silicon dioxide; The outer layer comprises a polypropylene random copolymer.

2. The polypropylene random copolymer pipe according to claim 1, characterized in that: The preparation method of the nano-silver-encapsulated microcapsule comprises: mixing acrylic acid, nano-silver, emulsifier A, and initiator A to react to obtain the nano-silver-encapsulated microcapsule; The weight ratio of the acrylic acid to the nano-silver is 1:(1-5).

3. The polypropylene random copolymer pipe according to claim 2, characterized in that: The weight ratio of the acrylic acid to the nano-silver is 1:(2-4).

4. The polypropylene random copolymer pipe according to claim 1, characterized in that: The preparation method of the microcapsule encapsulating aluminum hydroxide and silicon dioxide is as follows: methyl methacrylate, core material B, emulsifier B, and initiator B are mixed and reacted to obtain microcapsules encapsulating aluminum hydroxide and silicon dioxide; The core material B is aluminum hydroxide and silicon dioxide in a weight ratio of 1:(1-4).

5. The polypropylene random copolymer pipe according to claim 4, characterized in that: Include at least one of the following (1)-(2): (1) The core material B is aluminum hydroxide and silicon dioxide in a weight ratio of 1:(2-3); (2) The weight ratio of the methyl methacrylate to the core material B is 1:(0.1-5).

6. The polypropylene random copolymer pipe according to claim 5, characterized in that: The weight ratio of the methyl methacrylate to the core material B is 1:(1-4).

7. The polypropylene random copolymer pipe according to claim 1, characterized in that: Include at least one of the following (1)-(2): (1) The average particle size of the microcapsules encapsulating nanosilver is 1-15 μm; (2) The average particle size of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is 1-10 μm.

8. The polypropylene random copolymer pipe according to claim 7, characterized in that: Include at least one of the following (1)-(2): (1) The average particle size of the microcapsules encapsulating nanosilver is 1-10 μm; (2) The average particle size of the microcapsules encapsulating aluminum hydroxide and silicon dioxide is 1-7 μm.

9. The polypropylene random copolymer pipe according to claim 1, characterized in that: In the polypropylene random copolymer pipe, the inner layer thickness accounts for 10%-40% of the polypropylene random copolymer pipe wall thickness, the middle layer thickness accounts for 36%-54% of the polypropylene random copolymer pipe wall thickness, and the outer layer thickness accounts for 24%-36% of the polypropylene random copolymer pipe wall thickness.

10. A method for preparing a polypropylene random copolymer pipe as claimed in any one of claims 1 to 9, characterized in that: The steps include: S1. Mix the components of the inner layer to obtain an inner layer mixture; S2. Mixing the components of the intermediate layer to obtain an intermediate layer mixture; S3. Mix the components of the outer layer to obtain an outer layer mixture; S4. The inner layer mixture, the middle layer mixture and the outer layer mixture are co-extruded to obtain a polypropylene random copolymer pipe.

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