TW202332728A - High-antibacterial polypropylene material as well as preparation method and application thereof - Google Patents

Abstract

The invention provides a high-antibacterial polypropylene material as well as a preparation method and application thereof, and relates to the technical field of general-purpose plastics. The polypropylene material provided by the invention comprises the following components in parts by weight: 70-85 parts of polypropylene of which the isotacticity is greater than 90%, 5-30 parts of low isotactic polypropylene, 1-2 parts of a composite antibacterial agent and 2-5 parts of a processing aid, and the composite antibacterial agent is a compound of phenylglycine, chitosan and ethylenediaminetetraacetic acid. Phenylglycine, chitosan and ethylenediaminetetraacetic acid are compounded to serve as a composite antibacterial agent, low isotactic polypropylene with a certain proportion is introduced into the raw materials, the prepared polypropylene material has good antibacterial performance on candida albicans, escherichia coli, klebsiella pneumoniae and staphylococcus aureus, and the antibacterial rate can reach 99% or above. A metal antibacterial agent is not adopted, the content of heavy metal in the prepared polypropylene material is lower than the lowest industrial standard, and the application safety of the polypropylene material is greatly improved.

Description

High antibacterial polypropylene material and its preparation method and application

The invention relates to the technical field of general plastics, and in particular to a highly antibacterial polypropylene material and its preparation method and application.

Mask non-woven materials are required to have good antibacterial and sterilizing properties. Currently commonly used antibacterial agents include inorganic antibacterial agents, organic antibacterial agents and natural antibacterial agents. Among them, inorganic antibacterial agents mainly use metals such as silver, copper, and zinc to release good bactericidal properties. However, it is inevitable to use metal elements in this type of antibacterial agents. When used to prepare non-woven fabrics for masks that are in direct contact with human respiratory organs, etc. products, the presence of metal can cause potential hazards. Organic antibacterial agents or natural antibacterial agents do not contain metal elements, but their own stability is poor. During the mixing and high-temperature extrusion process of polypropylene, they are easily decomposed or deactivated, and thus cannot fully exert their own antibacterial properties. , reduce sterilization efficiency.

In order to solve the problems existing in the above-mentioned prior art, the main purpose of the present invention is to provide a highly antibacterial polypropylene material for non-woven fabrics and a preparation method thereof.

In order to achieve the above object, in the first aspect, the present invention proposes a polypropylene material, including the following components by weight: 70-85 parts of polypropylene with an isotacticity greater than 90%, and 40-60% of isotacticity. 5-30 parts of low isotactic polypropylene, 1-2 parts of composite antibacterial agent and 2-5 parts of processing aid, wherein the composite antibacterial agent is a compound of phenylglycine, chitosan and ethylenediaminetetraacetic acid thing,, place The melting point of the low isotactic polypropylene is 70-90°C.

In the technical solution of the present invention, on the one hand, phenylglycine, chitosan and ethylenediaminetetraacetic acid are compounded as a composite antibacterial agent. Among them, phenylglycine has good antibacterial activity, especially against Escherichia coli. Efficient bactericidal effect. As a natural bactericide, chitosan has good biocompatibility, biodegradability, no toxic side effects, and broad-spectrum antibacterial and antiviral properties. By adding ethylenediaminetetraacetic acid to phenylglycine and chitosan, ethylenediaminetetraacetic acid can stably exert the antibacterial and antibacterial effects of phenylglycine and chitosan.

On the other hand, this application introduces a certain proportion of low isotactic polypropylene into the raw materials. The melting temperature of low isotactic polypropylene is about 80°C, which is much lower than ordinary polypropylene (that is, polypropylene with an isotacticity greater than 90%). )164-170℃ melting temperature. During the melt blending process, low isotactic polypropylene is first coated on the surface of the antibacterial agent to form a protective layer to reduce the contact temperature of the antibacterial agent, thus protecting the composite antibacterial agent. , effectively preventing the antibacterial agent from decomposing or deactivating during the high-temperature extrusion process. After blending and extrusion, during the cooling process, due to the low crystallization rate of low isotactic polypropylene, the antibacterial agent is redistributed under the action of stress, and the composite antibacterial agent is further dispersed evenly in the polypropylene material.

Through the above technical solution, the polypropylene material prepared by the present invention has good antibacterial properties against Candida albicans, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus, and the antibacterial rate can reach more than 99%. Moreover, no metal antibacterial agent is used in this application, and the heavy metal content in the prepared polypropylene material is far lower than the minimum industry standard, which greatly improves the application safety of polypropylene materials in non-woven products and has broad application prospects.

As a preferred embodiment of the polypropylene material of the present invention, the weight ratio of phenylglycine, chitosan and ethylenediaminetetraacetic acid in the composite antibacterial agent is phenylglycine:chitopolymer Sugar: ethylenediaminetetraacetic acid = (1-3): (1-2): 1.

After extensive experiments, the inventor found that by optimizing the weight ratio of the three substances phenylglycine, chitosan and ethylenediaminetetraacetic acid in the composite antibacterial agent, the polypropylene material can exert a better antibacterial effect. When the weight ratio of phenylglycine, chitosan and ethylenediaminetetraacetic acid in the composite antibacterial agent is phenylglycine:chitosan:ethylenediaminetetraacetic acid=(1-3):(1-2):1 , the antibacterial properties of the polypropylene materials prepared correspondingly are much higher than those of polypropylene materials prepared under other ratios.

As a preferred embodiment of the polypropylene material of the present invention, the weight ratio of phenylglycine, chitosan and ethylenediaminetetraacetic acid in the composite antibacterial agent is phenylglycine:chitosan:ethylenediaminetetraacetic acid. =2:1:1.

As a preferred embodiment of the polypropylene material of the present invention, the melt mass flow rate of the low isotactic polypropylene is 50-390g/10min at 230°C and a load of 2.16Kg.

After a large number of experiments, the inventor found that the antibacterial properties of polypropylene materials prepared by adding low isotactic polypropylene with different melt mass flow rates are significantly different. When choosing low isotactic polypropylene with a melt mass flow rate of 50-390g/10min, Polypropylene materials made from regular polypropylene have better antibacterial properties.

As a preferred embodiment of the polypropylene material of the present invention, the processing aid includes at least one of a compatibilizer, a dispersant and a lubricant.

As a preferred embodiment of the polypropylene material of the present invention, the compatibilizer is maleic anhydride-grafted polypropylene; the dispersant is polyethylene wax; and the lubricant is vinyl distearamide and mustard. At least one kind of acid amide.

In a second aspect, the present invention also proposes a method for preparing polypropylene materials, which includes the following steps: combining polypropylene with an isotacticity greater than 90%, low isotactic polypropylene with an isotacticity of 40-60%, a composite antibacterial agent and After the processing aids are mixed in proportion, the material is first heated to 160°C for internal mixing for 10-20 minutes, and then extruded and granulated through a screw extruder to obtain the polypropylene material.

As a preferred embodiment of the polypropylene material preparation method of the present invention, the screw extruder includes 12 temperature control zones, the temperature in the first temperature control zone is 120-130°C, the temperature in the second temperature control zone is 160-190°C, and the temperature in the second temperature control zone is 160-190°C. The temperature in the third temperature control zone is 200-210℃, the temperature in the fourth temperature control zone is 210-220℃, the temperature in the fifth temperature control zone is 215-220℃, and the temperature in the sixth temperature control zone to the temperature control zone 12 is 180-200℃.

In a third aspect, the present invention also proposes the application of a polypropylene material in preparing antibacterial non-woven fabrics. The antibacterial non-woven fabric is a special antibacterial non-woven fabric for masks.

Compared with the existing technology, the beneficial effects of the present invention are:

(1) The technical solution of the present invention is to compound phenylglycine, chitosan and ethylenediaminetetraacetic acid as a composite antibacterial agent, and introduce a certain proportion of low isotactic polypropylene into the raw materials to utilize low isotactic polypropylene. Polypropylene is melted and coated on the surface of the antibacterial agent to form a protective layer, which reduces the contact temperature of the antibacterial agent, thereby protecting the composite antibacterial agent;

(2) The polypropylene material prepared by the present invention has good antibacterial properties against Candida albicans, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus, and the antibacterial rate can reach more than 99%;

(3) No metal antibacterial agent is used in the technical solution of the present invention, and the heavy metal content in the prepared polypropylene material is far lower than the minimum industry standard, which greatly improves the application safety of polypropylene materials in non-woven products and has broad application prospects. Application prospects.

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below through specific embodiments.

The raw material compositions of Examples 1-5 and Comparative Examples 1-4 are as shown in Table 1 below.

The low isotactic polypropylene used in Examples 1-5 and Comparative Examples 1-4 has a melting point of 80°C, a melt mass flow rate of 50g/10min at 230°C and a load of 2.16Kg, and the brand name is L-MODU S901, purchased from Idemitsu, Japan.

The preparation method of polypropylene materials in Examples 1-5 and Comparative Examples 1-4 includes the following steps: polypropylene with an isotacticity greater than 90%, low isotactic polypropylene with an isotacticity of 40-60%, composite After the antibacterial agent and processing aid are mixed in proportion, the material is first heated to 160°C for internal mixing for 10-20 minutes, and then extruded and granulated by a screw extruder to obtain the polypropylene composite material, in which the screw extrusion The machine includes 12 temperature control zones. The temperature in the first temperature control zone is 120-130°C, the temperature in the second temperature control zone is 160-190°C, the temperature in the third temperature control zone is 200-210°C, and the temperature in the fourth temperature control zone is 210-220°C. ℃, the temperature in the fifth temperature control zone is 215-220°C, and the temperature in the sixth temperature control zone to the twelfth temperature control zone is 180-200°C.

Table 1. Raw material composition of Examples 1-5 and Comparative Examples 1-4 (in parts by weight)

According to the EN 71-3:2019+A1:2021 standard, the polypropylene materials prepared in Examples 1-5 and Comparative Examples 1-4 were tested for heavy metal (Al, Sb, As, Ba, Cd, Cr, Co, Cu) content. Detection and analysis. The test results show that the content of the above-mentioned metal elements in the polypropylene materials prepared in Examples 1-5 and Comparative Examples 1-4 is far below the specified lower limit. This shows that the polypropylene materials prepared in Examples 1-5 and Comparative Examples 1-4 of the present application all meet the standard requirements.

According to JIS Z 2801: 2021 "Antibacterial Processed Products - Antibacterial Test Methods and Determination of Antibacterial Effect", the antibacterial rate of the samples against Candida albicans, Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus was tested. The antibacterial performance test results of Examples 1-5 and Comparative Examples 1-4 are shown in Table 2 below.

Table 2. Performance test results of Examples 1-5 and Comparative Examples 1-4 (bacterial inhibition rate: %)

It can be seen from Tables 1 and 2 that the polypropylene materials prepared in Examples 1-5 all have good antibacterial properties. Compared with Example 4, phenylglycine is not added in Comparative Example 1, chitosan is not added in Comparative Example 2, and ethylenediaminetetraacetic acid is not added in Comparative Example 3. The polypropylene materials prepared in Comparative Examples 1-3 are The antibacterial performance is greatly reduced, which shows that the three substances making up the composite antibacterial agent are indispensable.

Compared with Example 4, low isotactic polypropylene is not added in Comparative Example 4, and the antibacterial performance of the polypropylene material prepared in Comparative Example 4 is greatly reduced.

Using Example 4 as a reference, the effect of the proportion of each substance in the composite antibacterial agent on the antibacterial performance of the propylene material was investigated. The composition of raw materials is shown in Table 3 below.

Table 3. Raw material composition of Example 4 and Examples 6-10 (in parts by weight)

According to the EN 71-3:2019+A1:2021 standard, Example 4 and Examples 6-10 The prepared polypropylene material was tested and analyzed for heavy metal (Al, Sb, As, Ba, Cd, Cr, Co, Cu) content. The test results show that the contents of the above metal elements in the polypropylene materials prepared in Example 4 and Examples 6-10 all meet the standard requirements.

The antibacterial performance test results of Example 4 and Examples 6-10 are shown in Table 4 below.

Table 4. Antibacterial performance test results of Example 4 and Examples 6-10 (bacterial inhibition rate: %)

It can be seen from Tables 3 and 4 that the polypropylene materials prepared in Example 4 and Examples 6-10 have good antibacterial properties. Among them, phenylglycine, chitosan and ethylenediaminetetraacetic acid in the composite antibacterial agent of Example 8 The weight ratio of phenylglycine:chitosan:ethylenediaminetetraacetic acid=2:1:1, the corresponding polypropylene material has the highest antibacterial rate against four kinds of bacteria, indicating that under this ratio, the composite antibacterial agent can Give full play to the best antibacterial and antibacterial effects. The weight ratio of phenylglycine, chitosan and ethylenediaminetetraacetic acid in the composite antibacterial agent of Example 6 and Example 10 is not within the limited range. Although the corresponding polypropylene material shows a certain antibacterial effect, it is not as good as Antibacterial effect of polypropylene materials prepared in Examples 7, 4, and 8-9.

Example 11

The raw material composition and preparation method of this example are basically the same as those of Example 4. The only difference is that the melt mass flow rate of the low isotactic polypropylene used in this example is 390g/10min at 230°C and a load of 2.16Kg. .

Example 12

The raw material composition and preparation method of this example are basically the same as those of Example 4. The only difference is that the melt mass flow rate of the low isotactic polypropylene used in this example is 2600g/10min at 230°C and a load of 2.16Kg. .

According to the EN 71-3:2019+A1:2021 standard, heavy metal (Al, Sb, As, Ba, Cd, Cr, Co, Cu) content detection and analysis was performed on the polypropylene material prepared in Example 11-12. The test results show that the content of the above metal elements in the polypropylene materials prepared in Examples 11-12 is far below the specified lower limit, that is, the polypropylene materials prepared in Examples 11-12 of the present application all meet the standard requirements.

The antibacterial performance test results of Examples 11-12 are shown in Table 5 below.

Table 5. Antibacterial performance test results of Examples 11-12 (bacterial inhibition rate: %)

It can be seen from Table 5 that in Example 12, a low isotactic polypropylene with a melt mass flow rate of 2600g/10min was used, and the antibacterial performance of the corresponding polypropylene material was significantly lower than that of the polypropylene material prepared in Example 11, indicating that The melt mass flow rate of low isotactic polypropylene is too high, which will directly affect the antibacterial properties of polypropylene materials.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and do not limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that The technical solution of the present invention may be modified or equivalently substituted without departing from the essence and scope of the technical solution of the present invention.

Claims (9)

A polypropylene material, including the following components by weight: 70-85 parts of polypropylene with an isotacticity greater than 90%, 5-30 parts of low isotactic polypropylene with an isotacticity of 40-60%, and a composite antibacterial agent 1-2 parts and 2-5 parts of processing aids, wherein the composite antibacterial agent is a compound of phenylglycine, chitosan and ethylenediaminetetraacetic acid, and the polypropylene with an isotacticity greater than 90% The melting temperature of the low isotactic polypropylene is 164-170°C, and the melting temperature of the low isotactic polypropylene is 40-60%. The preparation method of the polypropylene material includes the following steps: making the isotacticity greater than 90% Polypropylene, low isotactic polypropylene with an isotacticity of 40-60%, compound antibacterial agents and processing aids are mixed in proportion, and then heated to 160°C for internal mixing for 10-20 minutes, and then passed through the screw The polypropylene material is obtained by extrusion and granulation with an extruder. The polypropylene material according to claim 1, wherein the weight ratio of phenylglycine, chitosan and ethylenediaminetetraacetic acid in the composite antibacterial agent is phenylglycine:chitosan:ethylenediaminetetraacetic acid. =(1-3):(1-2)：1. The polypropylene material according to claim 2, wherein the weight ratio of phenylglycine, chitosan and ethylenediaminetetraacetic acid in the composite antibacterial agent is phenylglycine:chitosan:ethylenediaminetetraacetic acid. =2:1:1. The polypropylene material as described in claim 1, wherein the melt mass flow rate of the low isotactic polypropylene is 50-390g/10min at 230°C and under a load of 2.16Kg. The polypropylene material according to claim 1, wherein the processing aid includes at least one of a compatibilizer, a dispersant and a lubricant. The polypropylene material as described in claim 5, wherein the compatibilizer is Malay Acid anhydride grafted polypropylene; the dispersant is polyethylene wax; the lubricant is at least one of vinyl distearamide and erucamide. The polypropylene material as described in claim 1, wherein in the preparation method, the screw extruder includes 12 temperature control zones, the temperature in the first temperature control zone is 120-130°C, and the temperature in the second temperature control zone is 160-190°C. ℃, the temperature in the third temperature control zone is 200-210°C, the temperature in the fourth temperature control zone is 210-220°C, the temperature in the fifth temperature control zone is 215-220°C, the temperature in the sixth temperature control zone to the twelfth temperature control zone is 180- 200℃. The application of the polypropylene material as described in any one of claims 1 to 7 in the preparation of antibacterial non-woven fabrics. The application as described in claim 8, wherein the antibacterial non-woven fabric is a special antibacterial non-woven fabric for masks.