JP7198601B2 - Antibacterial/antiviral resin composition - Google Patents

Description

The present invention relates to an antibacterial/antiviral resin composition.

Conventionally, various functional resin compositions have been proposed in which a functional material such as an antibacterial agent or an antiviral agent is added to impart functionality to the surface (see, for example, Patent Document 1). In this functional resin composition, the functional material present near the surface exerts its effect, whereas the functional material buried inside the resin does not exert its effect, so it is important to arrange the functional material on the surface. be.

In addition, the functional resin composition is required to have wear resistance and water resistance. When the surface of the functional resin composition disappears due to wear, the functional material buried inside the functional resin composition is exposed on the surface, so that the functionality can be maintained. On the other hand, when the functional material on the surface of the functional resin composition is eluted by water, the resin on the surface remains without disappearing, resulting in deterioration of functionality. That is, there is a problem that the functionality is lost early due to the elution of the functional material when it comes into contact with moisture during use.

Japanese Patent No. 3802272

By the way, if the functional material buried inside the resin is a low-molecular-weight substance of less than submicron order and easily mobile, it may move (bleed) inside the resin and migrate to the surface. That is, by increasing the fluidity of the functional material inside the resin, the functional material buried inside the resin can function on the surface.

The present invention has been made in view of the above, and by using a water-soluble antiviral agent and a resin with water absorption, the functional material buried inside the resin migrates to the surface of the resin and functions for a long time. The purpose is to provide an antibacterial and antiviral resin composition that can exhibit

(1) The antibacterial/antiviral resin composition (for example, the antibacterial/antiviral resin composition 1 described later) of the present invention exhibits water solubility with a polyamide resin (for example, the base resin 2 described later), An antibacterial/antiviral resin composition containing an antibacterial/antiviral agent (for example, an antibacterial/antiviral agent 3 described later) whose decomposition temperature is higher than the melting temperature of the polyamide resin.

(2) In the invention of (1), the antibacterial/antiviral agent is preferably slaked lime.

(3) In the invention of (1) or (2), the antibacterial/antiviral resin composition preferably further contains a filler.

(4) In the invention of (3), the filler is more preferably glass fiber.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an antibacterial/antiviral resin composition that exerts its function continuously over a long period of time.

FIG. 2 is a diagram showing bleeding of an antibacterial/antiviral agent in an antibacterial/antiviral resin composition according to an embodiment of the present invention. FIG. 2 is a diagram showing bleeding of an antibacterial/antiviral agent in an antibacterial/antiviral resin composition containing glass fibers according to an embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the amount of antibacterial/antiviral agent added and the amount of calcium ion (Ca ²⁺ ) elution in water in the antibacterial/antiviral resin composition according to the embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the amount of calcium ion eluted in water and the antiviral properties against each virus in the antibacterial/antiviral resin composition according to the embodiment of the present invention.

Embodiments of the present invention will be described below, but the present invention is not limited thereto.

FIG. 1 is a diagram showing bleeding of an antibacterial/antiviral agent in an antibacterial/antiviral resin composition according to an embodiment of the present invention.
The antibacterial/antiviral resin composition 1 according to the present embodiment comprises a polyamide-based base resin 2 and an antibacterial/antiviral agent 3 that exhibits water solubility and has a decomposition temperature higher than the melting temperature of the base resin 2. composed of The antibacterial/antiviral resin composition 1 exerts an antibacterial/antiviral effect on the surface due to the antibacterial/antiviral agent 3 present near the surface. Other raw materials can be added to the antibacterial/antiviral resin composition 1 as long as the effects of the present invention are not impaired. Examples thereof include polymerization inhibitors, curing agents, curing accelerators, dyes, plasticizers, ultraviolet absorbers, thixotropic agents, fillers, antifoaming agents, stabilizers and leveling agents.

As the base resin 2, a polyamide resin is used. Since the polyamide resin has high water absorption, bleeding occurs when the water-soluble antibacterial/antiviral agent 3 dissolves in the absorbed water, and the antibacterial/antiviral agent 3 inside the base resin 2 becomes an antibacterial/antiviral resin. As a result of migrating to the surface of composition 1, antibacterial and antiviral effects are exhibited continuously (see FIG. 1). Polyamide resins include 6-nylon and 6,6-nylon. Preferably, a polyamide resin having a water absorption of 1 wt % or more is used as the base resin 2 . A method for measuring water absorption will be described later in detail.

Since the antibacterial/antiviral agent 3 is added to the base resin 2 and injection molded or extruded, its decomposition temperature is required to be higher than the melting temperature (molding temperature) of the base resin 2 . Furthermore, from the viewpoint of ease of bleeding in the antibacterial/antiviral resin composition 1, it is necessary to be water-soluble. Substances exhibiting antibacterial and antiviral properties include quaternary ammonium salts, calcium hydroxide (slaked lime), copper-supported TiO ₂ and copper iodide. From the above point of view, slaked lime is more preferably used. This is because slaked lime is water-soluble and has a high decomposition temperature of 400° C. or higher, which is higher than the melting temperature of various polyamide resins (for example, 250° C. to 320° C.).

The antibacterial/antiviral agent 3 has an antibacterial action against bacteria such as Escherichia coli and Staphylococcus aureus, and an antiviral action against enveloped viruses and non-enveloped viruses.
Regarding the above antiviral properties, the antiviral properties can be evaluated by measuring the virus infectivity titer by the TCID50 method, targeting influenza A virus as an enveloped virus and feline calicivirus as a non-enveloped virus. It is possible.

Furthermore, the antibacterial/antiviral resin composition 1 preferably contains a filler 4 . In the antibacterial/antiviral resin composition 1, when the antibacterial/antiviral agent 3 dissolves in the absorbed water and bleeds, it is compared with when it passes through the gaps of the countless complex crosslinked structures of the base resin 2. This is because the inclusion of the filler 4 forms a path that is easy to pass through at the boundary between the filler 4 and the base resin 2, thereby promoting the bleeding of the antibacterial/antiviral agent 3 (Fig. 2 reference).

As the filler 4, a material that can be kneaded with resin is preferable, and for example, glass fiber or the like is more preferably used. This is because, along with the improvement in strength, the long fiber shape facilitates the formation of a path through which the antibacterial/antiviral agent 3 migrates to the surface of the antibacterial/antiviral antibacterial/antiviral resin composition 1 .

Next, a method for producing the antibacterial/antiviral resin composition 1 of this embodiment will be described.

Methods for producing the antibacterial/antiviral resin composition 1 include a pelletizing method, a direct addition method, a masterbatch method, and the like.

In the pelletizing method, the base resin 2 and the antibacterial/antiviral agent 3 are kneaded using a kneader to prepare pellets of the desired antibacterial/antiviral resin composition 1 . During kneading, the temperature of the base resin 2 is raised to the melting temperature or higher to melt the base resin 2 . An antibacterial/antiviral agent 3 is added to the molten base resin 2 according to the desired content, and the mixture is thoroughly kneaded, and when the mixture becomes uniform, it is molded into pellets. This pellet is used to manufacture a member by molding into a desired shape.

In the direct addition method, the antibacterial/antiviral resin composition 1 molded into the desired shape can be obtained by directly adding the antibacterial/antiviral agent when the base resin 2 is injection molded. The antibacterial/antiviral resin composition 1 can be obtained by putting the premixed base resin 2 and the antibacterial/antiviral agent 3 into an injection molding machine. The temperature during injection molding is equal to or higher than the melting temperature of the base resin 2, as in the pelletizing method.

In the masterbatch method, pellets with a high antibacterial/antiviral agent 3 content ratio are prepared in the pelletizing method, and then combined with the base resin 2 and put into an injection molding machine to produce an antibacterial/antiviral resin with the desired composition. Composition 1 is obtained.

The examples and comparative examples shown below are examples produced by the pelletizing method or the masterbatch method, but the effects of the present invention are exhibited similarly regardless of the above production methods.

EXAMPLES Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these. The detailed compounding ratios of the examples will be described later in Table 1 together with the evaluation results.

<Examples , Reference Examples, and Comparative Examples>
Polyamide resin is used as the base resin, and slaked lime (Kanto Kagaku reagent special grade) is used as the antibacterial/antiviral agent. The antibacterial/antiviral agent was kneaded into each resin using a kneader to prepare pellets. The kneading conditions were a screw diameter of φ25 mm, L/D=41, the number of kneading chambers was 8, and the kneading temperature was set in consideration of the melting temperature of the resin. For examples containing glass fiber as a filler, pellets were produced by adding a required amount of glass fiber during kneading. In each example , reference example, and comparative example, the following base resins were used.
( Reference Examples 1 to 4, Comparative Examples 1 and 8)
PA66 resin Amilan CM3007 (Toray)
(Comparative Examples 2-4 and 9-11)
ABS resin Toyolac 700-314 (Toray)
(Comparative Examples 5-7 and 12-14)
PP resin Novatec MA3UD (Japan Polypro)
( Reference Example 5, Examples 6 to 16, Comparative Example 15)
PA66 resin Leona 90G50 (Asahi Kasei)
(Examples 17 to 23, Comparative Example 16)
PAMXD resin Reny 1022F (Mitsubishi Engineering-Plastics)
Note that Leona 90G50 (Asahi Kasei) and Reny 1022F (Mitsubishi Engineering-Plastics) are resin products in which 50% by weight of glass fiber is mixed in advance with the base resin of commercially available products.

Using the obtained pellets, a molded product of the resin composition having a size of 150 mm×150 mm and a thickness of 3 mm was produced with an injection molding machine (ROBOSHOT S-2000i100B FANUC). The cylinder temperature was 270° C. for polyamide resin, 200° C. for PP resin, and 200° C. for ABS resin.

An antibacterial test, an antiviral test, an abrasion test, a water resistance test, and an elution test were performed on the above molded product to evaluate the antibacterial/antiviral performance and its sustainability. Test results are shown in Tables 1 to 5 below. The water absorption rate of the resin composition after molding was calculated by multiplying the water absorption rate of the base resin by the weight composition ratio.
[test]

<Antibacterial test>
An antibacterial evaluation test was conducted in accordance with JIS Z 2801 for the antibacterial properties of the resin. An infection titer log reduction value of 2.0 or more was judged to be effective.

<Antiviral test>
Regarding the antiviral properties of the resin, an antiviral evaluation test was conducted with reference to JIS Z 2801, using type A influenza virus as an enveloped virus and feline calicivirus as a non-enveloped virus, with a contact time of 24 hours. rice field. An infection titer log reduction value of 2.0 or more was judged to be effective.

<Water resistance test>
At a ratio of 50 ml of ultrapure water to the surface area of 25cm ² of the test piece, after immersing in ultrapure water for 16 hours, the above antibacterial / antiviral test was performed, and the antibacterial / antiviral properties of the resin surface after immersion in water. evaluated.

<Abrasion test>
Using a table cloth as a contact, a load of 1 kg per area of 10 cm×10 cm was applied to the test piece, and 7300 times of friction was applied with a sliding wear tester. After that, the antibacterial/antiviral test described above was performed to evaluate the antibacterial/antiviral properties of the resin surface after abrasion.

<Elution test>
In the resin composition using PA66 resin as the base resin, the test piece was prepared with an amount of antiviral agent added of 0 to 6 wt% for each of those containing glass fiber and those not containing glass fiber, and the test surface was 50 mm. The side and back surfaces of the test piece processed to a size of ×50 mm were sealed with Melcoat to prevent the elution of the antibacterial/antiviral agent from other than the test surface. Using 10 ml of ultrapure water per surface area of the test piece of 25 cm ² , the test surface was immersed in water, covered with plastic wrap to prevent the water from evaporating, and allowed to stand at a temperature of 25±1° C. for 24 hours.
Fig. 3 shows the elution amount of the antibacterial/antiviral agent per unit area of the test piece after standing, quantified by ion chromatography, and plotted against the amount of antibacterial/antiviral agent added to the test piece. be. FIG. 4 is a diagram plotting the logarithmic decrease in infection titer in the antibacterial/antiviral test described above in order to clarify the relationship between the eluted amount of calcium ions and the antibacterial/antiviral properties.

<Measurement of water absorption>
The water absorption rate of the prepared test piece was measured based on the increase in mass after being immersed in water for 24 hours.

The above test results are shown in Tables 1-5 below.

Regarding antibacterial and antiviral performance, as a result of conducting antibacterial and antiviral tests on the resin composition in the initial state before the water resistance test after production, all resin compositions containing antibacterial and antiviral agents It showed antibacterial and antiviral performance.

Next, regarding the durability of antibacterial and antiviral performance, antibacterial and antiviral tests were conducted on the resin composition after the wear test and water resistance test. In the present invention, "having sustained antibacterial and antiviral properties" is defined as having at least sustained antibacterial activity after the water resistance test.

The results of the antibacterial and antiviral tests conducted after the abrasion test were almost the same as those of the same test in the initial state. It is believed that the abrasion causes the resin itself to disappear and the antibacterial/antiviral agent inside the resin composition to be exposed, and as a result, it is possible to maintain the same surface state as the initial state of the resin composition. That is, even if the resin composition is worn, the antibacterial/antiviral agent disappears only at the worn portion, so the influence on the durability of the antibacterial/antiviral effect is small.

Furthermore, based on the results of the antibacterial/antiviral test conducted after the water resistance test, the durability of the antibacterial/antiviral performance was evaluated.

< Reference Examples 1 to 4, Comparative Examples 1 and 8>
・PA66 resin Amilan CM3007 (Toray) water absorption rate 1.5 wt%
(a) No glass fiber In Reference Examples 1 and 2, when no glass fiber was contained, good antibacterial properties were exhibited even after the water resistance test. In Reference Example 2, it also exhibited antiviral activity only against non-enveloped viruses. It is presumed that the antibacterial/antiviral agent inside the resin eluted to the surface.
(b) With glass fiber When glass fiber was contained, in Reference Examples 3 and 4, good antibacterial and antiviral properties were exhibited even after the water resistance test. Since the glass fiber is present inside the resin, a path through which moisture can easily pass is formed at the interface between the glass fiber and the resin, and compared to Reference Examples 1 and 2 that do not have a filler, more water inside the resin. It is presumed that the antibacterial/antiviral agent eluted to the surface.

<Comparative Examples 2 to 4 and 9 to 11>
・ABS resin Toyolac 700-314 (Toray) water absorption rate 0.4 wt%
(a) No glass fiber When glass fiber was not contained, no antibacterial/antiviral properties were exhibited in any of the examples. It is presumed that the antibacterial/antiviral agent on the surface flowed out due to immersion in water during the water resistance test, and there was not a sufficient amount of antibacterial/antiviral agent on the surface.
(b) With glass fiber In the case of containing glass fiber, Comparative Example 10 did not exhibit antibacterial and antiviral properties, and in Comparative Example 11, only good antibacterial properties were shown even after the water resistance test. It is presumed that the ABS resin has lower water absorption than the polyamide resin, and the elution of a sufficient amount of the antibacterial/antiviral agent onto the resin surface was not obtained.

<Comparative Examples 5-7 and 12-14>
・PP resin Novatec MA3UD (Japan Polypro) water absorption rate 0.1wt%
Regardless of the presence or absence of glass fiber, it did not show antibacterial and antiviral properties after the water resistance test. PP resin has even lower water absorption than ABS resin, and it is presumed that a sufficient amount of the antibacterial/antiviral agent was not eluted onto the resin surface.

< Reference Example 5 , Examples 6 to 16, Comparative Example 15>
・PA66 resin Leona 90G50 (Asahi Kasei)
The resin product is a resin product that contains glass fibers from the time of marketing. Reference Example 5 showed only antibacterial properties. All of Examples 6 to 16 exhibited antibacterial and antiviral properties, and particularly Examples 12 to 16 exhibited antiviral properties against both enveloped and non-enveloped viruses. In addition, the antibacterial/antiviral properties improved with the amount of antibacterial/antiviral agent added.

<Examples 17 to 23, Comparative Example 16>
・PAMXD resin Reny 1022F (Mitsubishi Engineering-Plastics)
The resin product is a resin product that contains glass fibers from the time of marketing. All of Examples 17 to 23 showed antibacterial and antiviral properties, and in particular, Examples 19 to 23 showed antiviral properties against all types of viruses.

Looking at the results of the elution test, in any of the resin compositions shown in FIG. 3, the elution amount of calcium ions increased with the addition amount of the antibacterial/antiviral agent. Calcium ions are presumed to be derived from slaked lime, and as shown in FIG. 4, the antiviral performance improved as the amount of calcium ions eluted increased.

In addition, the resin composition containing glass fiber as a filler showed a significantly increased amount of elution of calcium ions compared to the resin composition containing no filler. The glass fiber promotes the elution of slaked lime, and the slaked lime inside the resin functions on the resin surface, so it is presumed that the antiviral effect can be sustained even after elution in the water resistance test.

Furthermore, looking at the water absorption rate of the final product and the antibacterial and antiviral properties after the water resistance test, the resin composition containing no glass fiber showed good antibacterial and antiviral properties with a water absorption rate of 1.5 wt%. Depending on the amount of the antibacterial/antiviral agent added, the resin composition of 0.4 wt % has antibacterial properties, but no antiviral properties. On the other hand, resin compositions containing glass fibers exhibit good antibacterial and antiviral properties with a water absorption rate of 0.3 wt % or more. That is, the effects of the present invention can be increased by including glass fibers in the resin composition.

1 Antibacterial/antiviral resin composition 2 Base resin 3 Antibacterial/antiviral agent 4 Filler

Claims (3)

a polyamide-based resin;
an antibacterial/antiviral agent that exhibits water solubility and has a decomposition temperature higher than the melting temperature of the polyamide resin;
including fillers and
The polyamide-based resin is one or more polyamide-based resins containing at least 6,6-nylon,
The antibacterial/antiviral agent is slaked lime, and the content ratio is 1.00 to 6.00 wt%,
The antibacterial/antiviral resin composition , wherein the filler is glass fiber and has a content of 42.50 to 48.75 wt% . The antibacterial/antiviral resin composition according to claim 1, wherein the polyamide-based resin is 6,6-nylon, and the content is 50.25 to 51.50 wt%. The polyamide resin is 6,6-nylon and PAMXD6, and the content is 50.75 to 51.50 wt%,
The content ratio of the slaked lime is 3.00 to 6.00 wt%,
The antibacterial/antiviral resin composition according to claim 1, wherein the glass fiber content is 42.50 to 46.25 wt%.

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