A persistent and slow-release antibacterial masterbatch for polyolefin pipes and its preparation method

Abstract

The present invention discloses a persistent and slow-release antibacterial masterbatch for polyolefin pipes and a preparation method thereof. The antibacterial masterbatch is prepared from raw materials including linear low-density polyethylene, maleic anhydride grafted POE, a composite antibacterial agent, a pigment, and an antioxidant in certain proportions. The composite antibacterial agent is composed of a silver-loaded zirconium phosphate antibacterial agent and a zinc-loaded zirconium phosphate antibacterial agent. In the formula of the present invention, maleic anhydride grafted POE can greatly improve the dispersibility of inorganic substances such as the silver / zinc-loaded zirconium phosphate composite antibacterial agent and titanium dioxide in plastics. At the same time, maleic anhydride grafted POE coats the silver / zinc-loaded zirconium phosphate composite antibacterial agent, slows down its release amount, and extends the release time, enabling the prepared antibacterial masterbatch to have long-term antibacterial properties. It can also reduce the precipitation of silver, zinc and other ions and improve the hygienic performance of the polyolefin pipes prepared from the antibacterial masterbatch.

Description

Technical Field

[0001] The present invention relates to the technical field of antibacterial polyolefin pipes, and particularly relates to a sustained-release antibacterial masterbatch for polyolefin pipes and a preparation method thereof. Background Art

[0002] In recent years, with the improvement of the economic level, people have higher and higher requirements for the hygiene of products used in life, which puts forward higher requirements for various antibacterial materials on the market. Currently, common antibacterial agents can be divided into three categories: organic, inorganic, and natural. Inorganic antibacterial agents are made by loading antibacterial metals such as silver, zinc, or copper on inorganic substances such as zeolites, glass systems, and phosphates. Compared with organic antibacterial agents, inorganic antibacterial agents not only have high safety, but also have better persistence of antibacterial effects because they do not volatilize or decompose, and also have the characteristics of excellent heat resistance, and are more popular among the public.

[0003] Due to the particularity of the use environment and working conditions of polyolefin pipes, most of them require a service life of 50 years (the same life as the building). At the same time, most pipeline products are in contact with water, and there are also requirements for hygienic performance, especially for the precipitation of silver, zinc and other ions that play an antibacterial role. At the same time, due to the addition of inorganic antibacterial agents, the toughness of polyolefin pipes is reduced, especially the toughness at low temperatures. Summary of the Invention

[0004] Based on the above-mentioned prior art, the present invention provides a sustained-release antibacterial masterbatch for polyolefin pipes and a preparation method thereof. The antibacterial masterbatch has good antibacterial effects, especially can provide long-lasting and long-term antibacterial performance, and when polyolefin pipes are prepared with this antibacterial masterbatch as the raw material, other properties meet the relevant requirements specified in the national standard for polyolefin pipes.

[0005] The preparation method of the antibacterial masterbatch is simple, easy to operate, and has low preparation cost.

[0006] The technical solution adopted to achieve the above object of the present invention is as follows:

[0007] A sustained-release antibacterial masterbatch for polyolefin pipes is prepared from the following raw materials in parts by mass:

[0008]

[0009] The composite antibacterial agent is a compound of silver-loaded zirconium phosphate antibacterial agent and zinc-loaded zirconium phosphate antibacterial agent.

[0010] Further, in the composite antibacterial agent, the mass ratio of the phosphate-based silver-loaded antibacterial agent to the phosphate-based zinc-loaded antibacterial agent is 1-4:16-19.

[0011] Further, the pigment is titanium dioxide.

[0012] Furthermore, the antioxidant is a compound mixture of a hindered phenol antioxidant (1010) and a phosphite antioxidant (168).

[0013] A preparation method of a persistent and slow-release antibacterial masterbatch for polyolefin pipes includes the following steps:

[0014] S1. Mix silver-loaded zirconium phosphate antibacterial agent and zinc-loaded zirconium phosphate antibacterial agent evenly at a temperature not exceeding 40°C to prepare a composite antibacterial agent.

[0015] S2. Add linear low-density polyethylene, maleic anhydride-grafted POE, composite antibacterial agent, pigment, and antioxidant into a high-speed mixer, mix evenly, and then transfer them into a twin-screw extruder for melt blending and pelletizing to obtain the persistent and slow-release antibacterial masterbatch for polyolefin pipes.

[0016] Furthermore, when extruding with the twin-screw extruder, the extrusion temperature of the first section is 175 - 185°C, the extrusion temperature of the second section is 185 - 195°C, the extrusion temperature of the third section is 195 - 200°C, the die temperature is 200 - 210°C, and the rotation speed of the screw is 60 - 100 r / min.

[0017] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0018] 1. In the formula of the present invention, maleic anhydride-grafted POE can greatly improve the dispersion of inorganic substances such as silver-loaded / zinc-loaded zirconium phosphate composite antibacterial agent and titanium dioxide in plastics. At the same time, maleic anhydride-grafted POE coats the silver-loaded / zinc-loaded zirconium phosphate composite antibacterial agent, slows down its release rate, and extends the release time, enabling the prepared antibacterial masterbatch to have long-term antibacterial properties. It can also reduce the precipitation of silver and zinc ions and improve the hygienic performance of the polyolefin pipes prepared from the antibacterial masterbatch.

[0019] 2. In the formula of the present invention, maleic anhydride-grafted POE and the composite antibacterial agent cooperate with each other. While improving the antibacterial performance and hygienic performance, they can significantly improve the low-temperature brittleness of the polyolefin pipes prepared from the antibacterial masterbatch. The reason may be that the shell-core structure formed by maleic anhydride-grafted POE coating the composite antibacterial agent increases the fracture strain, thereby greatly improving its notched impact strength at low temperatures. Specific Embodiments

[0020] The present invention will be described in detail below with reference to specific embodiments, but these embodiments are not construed as limiting the protection scope of the present invention in any sense.

[0021] The raw materials used in the examples and comparative examples are as follows:

[0022] Linear low-density polyethylene (LLDPE): ExxonMobil 6101.

[0023] Silver-loaded zirconium phosphate antibacterial agent: Xiamen Jinda JDGKP-003.

[0024] Zinc-loaded zirconium phosphate antibacterial agent: Fuji Chemical Industry BM-102VT.

[0025] Silver-loaded zeolite antibacterial agent: Xuancheng Jingrui VK-Z03.

[0026] Zinc-loaded zeolite antibacterial agent: Kepuyin J151.

[0027] Silver-loaded glass antibacterial agent: Fuji Chemical Industry BM-103CK.

[0028] Zinc-loaded glass antibacterial agent: Fuji Chemical Industry BM-104KJ.

[0029] Maleic anhydride grafted POE: Yixing Haifei New Materials EPA-830M.

[0030] Example 1

[0031] A long-lasting and slow-release antibacterial masterbatch for polyolefin pipes is prepared from the following raw materials in parts by mass:

[0032]

[0033] The composite antibacterial agent is composed of 4 parts by mass of silver-loaded zirconium phosphate antibacterial agent and 16 parts by mass of zinc-loaded zirconium phosphate antibacterial agent.

[0034] The preparation method of the above-mentioned long-lasting and slow-release antibacterial masterbatch for polyolefin pipes is as follows:

[0035] S1. Mix the silver-loaded zirconium phosphate antibacterial agent and the zinc-loaded zirconium phosphate antibacterial agent evenly to prepare a composite antibacterial agent;

[0036] S2. Add linear low-density polyethylene, maleic anhydride grafted POE, composite antibacterial agent, pigment and antioxidant into a high-speed mixer and mix evenly;

[0037] S3. Transfer the materials mixed in the high-speed mixer into a twin-screw extruder for melt blending and extrusion, cutting, and drying to obtain the long-lasting and slow-release antibacterial masterbatch for polyolefin pipes. The parameters of the twin-screw extruder are as follows: the extrusion temperature of the first section is 180 °C, the extrusion temperature of the second section is 190 °C, the extrusion temperature of the third section is 200 °C, the die temperature is 205 °C, and the screw speed is 80 r / min.

[0038] Comparative Example 1

[0039] The difference from Example 1 lies in the composition of the composite antibacterial agent. In this comparative example, the composite antibacterial agent is a compound mixture of silver-loaded zeolite antibacterial agent and zinc-loaded zeolite antibacterial agent.

[0040] Comparative Example 2

[0041] It is different from Example 1 in the composition of the composite antibacterial agent. In this comparative example, the composite antibacterial agent is a compound mixture of silver-loaded glass antibacterial agent and zinc-loaded glass antibacterial agent.

[0042] Comparative Example 3

[0043] It is different from Example 1 in the composition of the composite antibacterial agent. In this comparative example, the composite antibacterial agent is a compound mixture of silver oxide and zinc oxide.

[0044] The antibacterial properties of the antibacterial masterbatches of Example 1 and Comparative Examples 1-3 were tested under the condition of soaking in water, and the test results are shown in Table 1 below:

[0045] Table 1 Comparison of antibacterial properties of different antibacterial masterbatches

[0046]

[0047] As can be seen from Table 1, different composite antibacterial agents are combined with maleic anhydride grafted POE, and the effects are different. Only when the composite antibacterial agent prepared by compounding silver-loaded zirconium phosphate antibacterial agent and zinc-loaded zirconium phosphate antibacterial agent is combined with maleic anhydride grafted POE can the long-term antibacterial property of the antibacterial masterbatch be achieved. The effects of zeolite silver / zinc composite antibacterial agent, glass silver / zinc composite antibacterial agent, and silver oxide / zinc composite antibacterial agent are not ideal.

[0048] Comparative Example 4

[0049] It is different from Example 1 in that maleic anhydride grafted POE is not added.

[0050] The antibacterial properties and hygienic properties of the antibacterial masterbatches prepared in Example 1 and Comparative Example 4 were tested under the condition of soaking in water (measured at 24 h of soaking), and the results are shown in Table 2 below:

[0051] Table 2 Comparison of antibacterial properties and hygienic properties of different antibacterial masterbatches

[0052]

[0053] As can be seen from Table 2, adding maleic anhydride grafted POE not only improves the antibacterial rate and the antibacterial effect of polyolefin pipes, but also reduces the precipitation of silver and zinc ions, improving the hygienic properties of polyolefin pipes.

[0054] Comparative Example 5

[0055] It is different from Example 1 in that the composite antibacterial agent is not added.

[0056] Comparative Example 6

[0057] It is different from Example 1 in that no compound antibacterial agent and maleic anhydride grafted POE are added.

[0058] The antibacterial masterbatches prepared in Example 1 and Comparative Examples 4-6 were added to the preparation of polyolefin pipes in the same proportion, and the notched Izod impact strength of the prepared polyolefin pipes under different temperature conditions was tested. The results are shown in Table 3 below:

[0059] Table 3 Test results of notched impact strength of different polyolefin pipes under different temperature conditions

[0060] Pipe material Notched impact strength (23°C) (kJ / ㎡) Notched impact strength (-20°C) (kJ / ㎡) Example 1 72 3.2 Comparative Example 4 30 1.1 Comparative Example 5 45 2.0 Comparative Example 6 40 1.8

[0061] As can be seen from Table 3, maleic anhydride grafted POE and the compound antibacterial agent cooperate with each other, significantly improving the notched impact strength of polyolefin pipes and significantly improving the low-temperature brittleness of polyolefin pipes prepared from antibacterial masterbatches.

Claims

1. A persistent and slow-release antibacterial masterbatch for polyolefin pipes, characterized in that it is prepared from the following raw materials in parts by mass: linear low density polyethylene 40 - 60 parts maleic anhydride grafted POE 10 - 20 parts compound antibacterial agent 15 - 20 parts pigment 20 - 30 parts antioxidant 0.1 - 0.5 parts; the compound antibacterial agent is a compound of silver-loaded zirconium phosphate antibacterial agent and zinc-loaded zirconium phosphate antibacterial agent, and the mass ratio of the silver-loaded zirconium phosphate antibacterial agent to the zinc-loaded zirconium phosphate antibacterial agent is 1 - 4:16 - 19.

2. The persistent and slow-release antibacterial masterbatch for polyolefin pipes according to claim 1, characterized in that: the pigment is titanium dioxide.

3. The persistent and slow-release antibacterial masterbatch for polyolefin pipes according to claim 1, characterized in that: the antioxidant is a compound mixture of hindered phenol antioxidants and phosphite antioxidants.

4. A preparation method of a persistent and slow-release antibacterial masterbatch for polyolefin pipes, characterized in that it comprises the following steps: S1. Mix the silver-loaded zirconium phosphate antibacterial agent and the zinc-loaded zirconium phosphate antibacterial agent evenly to prepare a compound antibacterial agent; S2. Add the linear low density polyethylene, maleic anhydride grafted POE, compound antibacterial agent, pigment and antioxidant into a high-speed mixer, mix evenly, then transfer to a twin-screw extruder for melt blending extrusion, cutting and drying to obtain the persistent and slow-release antibacterial masterbatch for polyolefin pipes.

5. The preparation method of the persistent and slow-release antibacterial masterbatch for polyolefin pipes according to claim 4, characterized in that: when the twin-screw extruder extrudes, the extrusion temperature of the first section is 175 - 185 °C, the extrusion temperature of the second section is 185 - 195 °C, the extrusion temperature of the third section is 195 - 200 °C, the die temperature is 200 - 210 °C, and the rotation speed of the screw is 60 - 100 r / min.

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