TW201937020A - Knitted item - Google Patents

Abstract

To provide a knitted item which exhibits insect-repelling capabilities with limited degradation of the mechanical properties of said knitted item. The present invention is a knitted item comprising a plurality of yarns, some of said yarns being multifilaments that are composed of several monofilaments and contain an insect-repellent. Each monofilament can be composed of a core-sheath structure having a core which contains the insect-repellent and is formed from a thermoplastic resin, and a sheath which covers the core and is formed from a thermoplastic resin. A knitted item having a marquisette structure can be used as this knitted item. Some of the yarns can be used as yarns which are not chain-stitch yarns in the marquisette structure.

Description

Braid

The present invention relates to a knitted fabric capable of exerting an insect-proof function and suppressing a decrease in mechanical properties.

Patent Document 1 describes an insect-resistant fiber having a core-sheath structure. Here, the core portion is formed of a thermoplastic resin containing an insect repellent, and the sheath portion is formed of a thermoplastic resin. According to the insect-proof fiber described in Patent Document 1, the insect-proof function can be exerted.

Patent Document 2 describes an insect-proof net composed of insect-resistant threads of monofilament fibers. Here, the insect control line includes an insect control agent holding section that holds the liquid insect control agent, and a release control section that is disposed outside the insect control agent holding section and releases the insect control agent. According to the insect-proof net described in Patent Document 2, the insect-proof function can be performed.
[Prior technical literature]
[Patent Literature]

Patent Document 1: International Publication No. 2016/143809 Patent Document 2: New Patent Registration No. 3196082

[Questions to be Solved by the Invention]

According to Patent Documents 1 and 2, although the insect-proof function can be exhibited, the insect-resistant fiber or insect-resistant thread contains the insect-resistant agent, and the tensile strength or elongation of the insect-resistant fiber or the insect-resistant thread is accompanied by aging. Easy to get worse. In this case, there is a possibility that the mechanical properties (tensile strength or elongation) required for the insect-resistant fiber or the insect-resistant thread may not be satisfied.

Here, an object of the present invention is to provide a knitted fabric which can exhibit an insect-proof function and suppress a reduction in mechanical properties.

[Means to solve the problem]

The present invention is a knitted fabric formed by a plurality of filaments. Among the plurality of filaments, a part of the filaments is composed of a plurality of monofilament fibers, and is a composite fiber containing an insecticide.

As the knitted system, a knitted fabric having a marquisette structure can be used. Here, a part of the above-mentioned number of filaments can be used in addition to the chain-like stitches in the Leno tissue.

The monofilament fiber may be composed of a core-sheath structure including a core portion formed of a thermoplastic resin containing an insect repellent, and a sheath portion formed of a thermoplastic resin covering the core portion. The weight ratio of the core portion and the sheath portion (core portion: sheath portion) may be 1: 9 to 9: 1, 1: 9 to 5: 5 is more preferable, and 2: 8 to 4: 6 is more preferable. The knitted fabric of the present invention can be used as a material for insect-resistant products.

[Inventive effect]

According to the present invention, since a part of the plurality of threads constituting the knitted fabric is a composite fiber containing an insect repellent, the insect repellent can be released outside the threads to exert the insect repellent function. In addition, the insect repellent is contained only in a part of the number of threads, and by using the other threads, the mechanical properties of the knitted fabric can be ensured and the deterioration of the mechanical properties can be suppressed.

The knitted fabric of this embodiment is composed of a plurality of threads. First, a description will be given of a part of the plurality of wires constituting the knitted fabric. This number of filaments is a composite fiber composed of a plurality of monofilament fibers. It is preferable that the monofilament fiber has a core-sheath structure. Next, among the plurality of yarns constituting the knitted fabric, a description is made of other yarns other than the above-mentioned partial yarns (composite fibers having a core-sheath structure). The other yarn is preferably a composite fiber, and the monofilament fibers constituting the composite fiber have a single-layer structure and have no core-sheath structure.

As the knitted fabric system, for example, a knitted fabric having a tulle structure can be used. Tulle is woven using twisted threads. FIG. 1 shows the tissue of the leno, and FIG. 2 shows the knitting method of the three threads A to C constituting the tissue of the leno. The thread A is a chain-like knitting method, and the threads B and C are inserted wires that are wound around the thread A. By combining the lines A to C shown in FIG. 2, a tulle structure shown in FIG. 1 can be obtained.

Lines A to C are composite fibers, respectively. Some of the yarns in the yarns A to C are composite fibers composed of a plurality of monofilament fibers having a core-sheath structure, and the remaining yarns are composite fibers composed of a plurality of monofilament fibers having no core-sheath structure.

For example, at least one of the threads B and C other than the thread A of the chain-like weave may be used as a composite fiber, and the composite fiber may be composed of a plurality of monofilament fibers having a core-sheath structure. In this case, a composite fiber composed of a monofilament fiber having no core-sheath structure is used as the thread A. Preferably, only the thread C is used as a composite fiber, and the composite fiber is composed of a plurality of monofilament fibers having a core-sheath structure. In this case, composite fibers composed of monofilament fibers having no core-sheath structure are used as the threads A and B.

As described later, the monofilament fiber having a core-sheath structure contains an insect repellent at the core, whereby the insect repellent can be released to the outside of the monofilament fiber. As shown in FIG. 2, compared with the line A, the lines B and C are expanded in the lateral direction of FIG. 2, and at least one of the lines B and C is a composite composed of a plurality of monofilament fibers having a core-sheath structure The fiber thereby makes it easy to release the insect repellent from the entire knitted fabric, and it becomes easy to exert the insect repellent function.

Moreover, the knitted fabric system of the present invention is not limited to a knitted fabric having a tulle structure. That is, a braid is constituted by a plurality of filaments, and among the plurality of filaments, a part of the filaments may be a composite fiber composed of a plurality of monofilament fibers as described above. The fiber system preferably has a core-sheath structure. The knitted fabric of the present invention can be used as a material for insect-resistant products. Examples of the insect-proof products include agricultural insect-proof nets, panel screens, roll-up screens, folding screens, mosquito nets, clothes, hats, and scarves. In addition, when making insect nets, screens, and mosquito nets, depending on the required application, flameproof processing or hardening is preferred. When flameproof processing is used, an organic system (organic phosphorus system, bromine (halogen) system, etc.) and / or an inorganic system (metal oxide system, inorganic phosphorus system, boron system, and silicon dioxide system) may be appropriately used. Etc.). In the case of hardening, the resin is not particularly limited, and acrylic resin, polyester resin, glyoxal resin, melamine resin, urea resin, phenol resin, polyurethane resin, silicone resin, alkyd resin, Vinyl chloride resin, fluororesin, cellulose resin, UV curing resin, etc.

Next, the monofilament fiber which has a core-sheath structure is demonstrated using FIG. 3. FIG.

The monofilament fiber 1 includes a core portion 2 and a sheath portion 3. The core portion 2 is made of a thermoplastic resin, and the insect repellent 4 is held by the core portion 2 while being dispersed in the core portion 2. The sheath portion 3 is made of a thermoplastic resin, and is in contact with the outer surface of the core portion 2 so as to cover the core portion 2. After the insect repellent 4 moves from the core portion 2 to the sheath portion 3, it is released from the outside of the sheath portion 3 to the outside of the monofilament fiber 1. This monofilament fiber 1 has a core-sheath structure, whereby the sustained-release property can be improved.

The thermoplastic resin constituting the core portion 2 and the sheath portion 3 is capable of maintaining the shapes of the core portion 2 and the sheath portion 3 and the insect repellent 4 can be released to the outside of the monofilament fiber 1 without any particular limitation. Here, the thermoplastic resin constituting the core portion 2 and the sheath portion 3 may be the same or different.

Examples of the thermoplastic resin include polyester, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate. , Nylon, acrylic, polyvinylidene fluoride, polyethylene tetrafluoroethylene, polytetrafluoroethylene, polyvinyl alcohol, Kevlar (registered trademark), polyacrylic acid, polymethyl methacrylate, gadolinium, Copper ammonium rhenium, Tencel (registered trademark), rhenium staple fiber, acetate, triacetate.

Among these thermoplastic resins, as the thermoplastic resin constituting the core portion 2 and the sheath portion 3, a crystalline thermoplastic resin can be used in terms of ensuring the strength of the core portion 2 or the sheath portion 3. Specific examples of the crystalline thermoplastic resin include polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, nylon, and polyvinylidene fluoride. Among these, polyethylene, polypropylene, polyethylene terephthalate, polybutylene terephthalate, and the like are more preferable as the thermoplastic resin for easily spinning the monofilament fiber 1.

Moreover, the monofilament fiber which does not have a core-sheath structure can also be formed from the thermoplastic resin mentioned above. In addition, although the insecticide 4 is contained only in the core part 2 in this embodiment, the insecticide 4 may be contained only in the sheath part 3, or the insecticide 4 may be contained in both the core part 2 and the sheath part 3.

In the present embodiment, the crystallinity of the thermoplastic resin constituting the sheath portion 3 may be equal to or less than the crystallinity of the thermoplastic resin constituting the core portion 2. The crystallinity of a thermoplastic resin depends on the material of the thermoplastic resin, or the heating temperature or elongation ratio during heating and stretching after melt spinning. With this, if the relationship between the crystallinity, the material of the thermoplastic resin, and the heating temperature or elongation ratio during heating and stretching after melt spinning is determined in advance, the crystallinity of the thermoplastic resin constituting the sheath portion 3 can be constituted by The method for setting the crystallinity of the thermoplastic resin of the core 2 or less is to set the material of the thermoplastic resin and the heating temperature or elongation ratio when heating and stretching after melt spinning.

In addition, the crystallinity of the thermoplastic resin constituting the sheath portion 3 may be set to a material of the thermoplastic resin such that the crystallinity of the thermoplastic resin constituting the core portion 2 is equal to or lower than the crystallinity of the thermoplastic resin constituting the core portion 2 without performing heat stretching. The crystallinity of the thermoplastic resin constituting the core portion 2 and the sheath portion 3 can be measured by, for example, a powder X-ray diffraction method. The crystallinity of the thermoplastic resin constituting the core portion 2 can be considered to be the same as the crystallinity of the thermoplastic resin constituting the core portion 2 (fiber) of the single-layer structure. The conditions of the part 2 are formed under the same conditions.

When the crystallinity of the thermoplastic resin constituting the sheath portion 3 is less than or equal to the crystallinity of the thermoplastic resin constituting the core portion 2, the insect repellent 4 can be easily moved mainly in the amorphous portion of the sheath portion 3, and the insect repellent 4 can be easily moved. Release toward the outside of the monofilament fiber 1. Thereby, the insect-proof function can be exerted. Here, when the crystallinity of the thermoplastic resin constituting the sheath portion 3 is greater than the crystallinity of the thermoplastic resin constituting the core portion 2, the insect repellent 4 becomes difficult to move the sheath portion 3 and is difficult to release to the outside of the monofilament fiber 1. Therefore, the insect-proof function is easily reduced.

The crystallinity of the thermoplastic resin constituting the core portion 2 is preferably 10% or more and 100% or less, and more preferably 40% or more and 100% or less. The crystallinity of the thermoplastic resin constituting the sheath portion 3 may be less than or equal to the crystallinity of the thermoplastic resin constituting the core portion 2. Specifically, the thermoplastic resin constituting the core portion 2 may be within a range of 10% to 100%. The degree of crystallinity (10% or more and 100% or less) is more preferable, and in the range of 40% or more and 100% or less, the crystallinity (40% or more and 100% or less) of the thermoplastic resin constituting the core portion 2 is less than For the better. More preferably, the crystallinity of the thermoplastic resin constituting the sheath portion 3 can be 10% or more and 80% or less, and more preferably, it can be 40% or more and 80% or less.

The weight ratio of the core portion 2 and the sheath portion 3 (core portion 2: sheath portion 3) may be 1: 9 to 9: 1. Although the core part 2 contains the insect repellent 4 in this embodiment, the weight of the core part 2 referred to here is the weight of the core part 2 except the insect repellent 4. When the weight ratio of the core 2 and the sheath 3 deviates from the upper limit (1: 9) of the above-mentioned range, the weight of the sheath 3 is relative to the weight of the core 2 (in other words, the diameter of the core 2). (In other words, the thickness of the sheath portion 3) becomes too large, and the insect repellent 4 contained in the core portion 2 becomes difficult to be released to the outside of the monofilament fiber 1. On the other hand, when the weight ratio of the core portion 2 and the sheath portion 3 deviates from the lower limit value (9: 1) of the above-mentioned range, the weight of the sheath portion 3 becomes too small relative to the weight of the core portion 2, and The insect repellent 4 contained in the core 2 becomes excessively released to the outside of the monofilament fiber 1. The weight ratio of the core portion 2 and the sheath portion 3 is preferably 1: 9 to 5: 5, and even more preferably 2: 8 to 4: 6.

When the insect repellent 4 held by the core 2 is a monofilament fiber 1 and melt-spun, the insect repellent 4 may remain in the core 2 of the monofilament fiber 1, and there is no particular limitation, and the practitioner may appropriately select it. For example, a microencapsulated insect repellent 4 can be used, or an insect repellent 4 can be carried on a porous material.

In this embodiment, it is preferable to use the microencapsulated insecticide 4. The microencapsulated insect repellent 4 is one in which the insect repellent 4 is filled in a microcapsule as a liquid compound. When the monofilament fiber 1 is melt-spun using a crystalline thermoplastic resin, the insect repellent 4 is transferred to the amorphous portion of the thermoplastic resin, and the insect repellent 4 that cannot stay in the amorphous portion inadvertently oozes to the monofilament. The outside of the silk fiber 1. For this reason, tackiness (adhesiveness) is generated and it becomes difficult to weave, or it is necessary to make the insecticide 4 more than necessary when melt-spinning. If a microencapsulated insect repellent 4 is used, the insect repellent 4 as a liquid compound is left in the microcapsules during melt spinning, and the insect repellent 4 can be inhibited from being transferred to the amorphous portion of the thermoplastic resin. Therefore, the insect repellent 4 may not easily leak to the outside of the monofilament fibers 1. Thereby, the adhesiveness is not easily generated, and the use of the insect repellent 4 in a necessary amount or more can be suppressed.

In addition, in the present embodiment, it is preferable to use the insect repellent 4 carried on the inorganic compound for controlling the release of the insect repellent 4. Examples of the inorganic compound that controls the release of the insect repellent 4 include particulate, fibrous, plate-like, scale-like, and layer-like inorganic compounds. These inorganic compounds are more preferably porous materials in order to increase the surface area on which the insecticide 4 can be carried. The use of the insect-repellent agent 4 carried by the inorganic compound for controlling the release of the insect-repellent agent 4 makes it difficult for the insect-repellent agent 4 to seep out of the monofilament fiber 1. Thereby, it is not easy to generate adhesiveness, and it is possible to release the minimum necessary insect repellent 4 which can exhibit the insect repellent function.

The insecticide 4 of the present embodiment is preferably a liquid compound containing the monofilament fiber 1. The use of the liquid compound insect repellent 4 makes it possible to add a high concentration of the insect repellent 4 to the core 2 in a stable state, and it becomes easy to adjust the diffusion speed of the insect repellent 4 in the interior of the monofilament fiber 1. . Moreover, the main component of the insect repellent 4 is not specifically limited, However, It is preferable that it is a liquid form at normal temperature. Specific examples of the main component of the insect repellent 4 include pyrethrin, guarinin, jasmonate, pyrethrin, pyrethrum, fenvalerate, permethrin, and the like. Synthetic pyrethroid insect repellents; Cyclodiene insect repellents such as toxaphen, Benzoepin; organophosphorus insect repellents such as marathon and chlorphene; Carbaryl, nalide, Promecarb, etc. Urethane-based insect repellent and the like. These insect repellents can be used in one kind or in combination of two or more kinds. Among these insect repellents, synthetic pyrethroid insect repellents which have excellent insect repellent properties and fast-acting properties, and which do not easily express acute toxicity, are suitable. In addition, among the synthetic pyrethroids, permethrin or permethrin that is easy to exhibit an insect-repellent function at a low concentration and easy to ensure safety to humans or animals is also suitable.

In the present embodiment, in the monofilament fiber 1 having the core portion 2 and the sheath portion 3, in order to release the insecticide 4 contained in the core portion 2 to the outside of the monofilament fiber 1 through the sheath portion 3, the sheath portion is provided in the sheath portion. In 3, the release of the insecticide 4 can be adjusted. Next, the insect repellent 4 can also suppress the spread to the outside of the monofilament fiber 1, can ensure safety to humans or animals, and can extend the duration of the insect repellent function.

In the present embodiment, the monofilament fiber 1 contains the insect repellent 4 in the core portion 2 and the insect repellent 4 passes through the sheath portion 3, so that the exudation of the insect repellent 4 in the surface of the monofilament fiber 1 can be suppressed, and Not easy to produce adhesiveness. Therefore, when a knitted fabric is knitted using a composite fiber composed of a plurality of monofilament fibers 1, the knitted fabric can be easily knitted.

In addition, when the surface of the monofilament fiber is prone to stickiness, dust and the like tend to adhere to the surface of the monofilament fiber. Dust or the like adhering to the surface of the monofilament fibers is not good because it inhibits the release of the insect repellent from the monofilament fibers and lowers the insect control function. In addition, when the monofilament fibers are washed (for example, washed with water) in order to remove the dust and the like attached to the monofilament fibers, the dust and the like are removed together with the insect repellent, and the release of the insect repellent from the monofilament fibers is accidentally promoted, So that the duration of the insect protection function is shortened.

On the other hand, in the present embodiment, as described above, in order to suppress the exudation of the insect repellent 4 on the surface of the monofilament fiber 1, it is easy to suppress dust and the like from adhering to the surface of the monofilament fiber 1. Dust and the like hinder the release of the insecticide 4. In addition, since the number of times of washing of the monofilament fiber 1 is also controlled, the removal of the insect repellent 4 during washing can be suppressed, and the time of the insect repellent function can be extended.

The manufacturing method of the monofilament fiber 1 can be appropriately selected by a person skilled in the art, and is not particularly limited. For example, as a reasonable and inexpensive manufacturing method of the monofilament fiber 1, the thermoplastic resin constituting the core portion 2 of the monofilament fiber 1 is filled with an insecticide 4 and the core portion 2 and the sheath portion 3 are melt-spun. Methods. Specifically, master batch pellets are manufactured in advance from pellets of a thermoplastic resin or the like containing the liquid insect repellent 4, and the pellets of the same thermoplastic resin as the master batch pellets and the master batch pellets are simultaneously mixed at a certain ratio and manufactured.芯 部 2。 Core portion 2. Next, using the pellets of the thermoplastic resin as the sheath portion 3, a monofilament fiber 1 was produced using a known core-sheath spinning device.

Here, the monofilament fiber 1 can be heated and drawn after spinning. Here, the crystallinity of the thermoplastic resin, the outer diameter of the monofilament fiber 1 and the like can be controlled by controlling the heating temperature during heating and stretching or the stretching ratio obtained by heating and stretching.

In the present embodiment, the content of the insect repellent 4 in the monofilament fiber 1 is preferably 0.1 mass% or more and 10 mass% or less with respect to the monofilament fiber 1 system. When the content rate of the insect repellent 4 is less than 0.1% by mass, the insect repellent function becomes lower than when the content rate of the insect repellent 4 is 0.1% by mass or more, and the duration of the insect repellent function is also shortened. When the content of the insect repellent 4 exceeds 10% by mass, the mass of the monofilament fiber 1 becomes the mass of the resin in the core 2 and the sheath 3 of the skeleton compared to the case where the content of the insect repellent 4 is 10% by mass or less. % Decreases, and the strength of the monofilament fiber 1 decreases. Moreover, it becomes easy to produce adhesiveness, making the knitted fabric difficult to knit. In addition, although it also depends on the thickness of the sheath portion 3, the higher the content rate of the insect repellent 4, the more the amount of the insect repellent 4 released on the surface of the monofilament fiber 1, and the insect repellent 4 for humans or animals Inadvertently increased intake. The content of the insecticide 4 in the monofilament fiber 1 is preferably 0.1% by mass or more and 5% by mass or less based on the monofilament fiber 1. When the content rate of the insecticide 4 is 0.1 mass% or more and 5 mass% or less, it becomes difficult to produce adhesiveness, and a knitted fabric becomes easy to knit. In addition, the insect repellent 4 becomes less prone to excessive release, and safety for humans and the like can be easily ensured.

In addition, the monofilament fiber 1 or the monofilament fiber having a single-layer structure may include a component for imparting an arbitrary function as a functional material. Examples of the functional materials include titanium dioxide or silica as a matting agent, fine particles such as calcium stearate, silica or alumina as lubricants, hindered phenol derivatives as antioxidants, and coloring agents such as pigments, Functional materials other than additives such as stabilizers and dispersants, ultraviolet shielding agents, near-infrared shielding agents, antibacterial agents, antifungal agents, antistatic agents, flame retardants, weathering agents, and various catalysts. Moreover, when the monofilament fiber 1 contains a functional material, the functional material and the insecticide 4 are dispersed in the core portion 2 and exist at the same time, or they are dispersed in the sheath portion 3 and exist, or they are attached to the monomer The surface of the silk fiber 1 is sufficient. In addition, when the monofilament fiber having a single-layer structure contains a functional material, the functional material may be dispersed inside the monofilament fiber and exist, or it may be adhered to the surface of the monofilament fiber.

In addition, the inorganic fine particles may be chemically bonded to the surface of the monofilament fiber 1 or the surface of the monofilament fiber having a single-layer structure to form fine unevenness. Due to the formation of fine irregularities, dust and the like suspended in the air do not easily adhere to the surface of the monofilament fiber. Furthermore, even when dust or the like adheres to the surface of the monofilament fiber, the insect repellent 4 exposed on the surface of the monofilament fiber is not removed, and only the dust can be simply removed with water or the like. Therefore, it becomes a monofilament fiber excellent in dust resistance.

The cross-sectional shape of the monofilament fiber 1 or the cross-sectional shape of the monofilament fiber having a single layer structure can be a special shape such as a circle, a flat shape, a triangle, a hollow shape, a star shape, or the like. Among the cross-sectional shapes described above, it is preferable that the cross-sectional shape of the monofilament fiber is circular from the viewpoints of abrasion resistance, posture stability, and smoothness.

Examples of the present invention will be described below.

(Example 1)
(Manufacture of insect-resistant thread)
A masterbatch pellet made of a highly crystalline homopolypropylene resin containing permethrin (insecticide) is prepared. Prepare pellets made of highly crystalline homopolypropylene resin. The master batch particles and the highly crystalline homopolypropylene resin are melted and mixed to obtain a mixture containing permethrin at a specific content rate. A melt extruder installed in a melt spinning device was used to individually melt the obtained mixture and prepared pellets.

The melted mixture and pellets are ejected from a spinneret for a core-sheath type composite fiber installed in a melt-spinning device, and collected at a specific speed while cooling in a water tank to obtain a monofilament fiber having a core-sheath structure. . The obtained monofilament fiber was stretched to a specific stretch ratio while being stretched with warm water (extension tank) heated at a specific temperature. The stretched monofilament fiber was wound around a bobbin by providing a groove to obtain a monofilament fiber having a core-sheath structure with a core to sheath weight ratio (core: sheath) of 3: 7. Here, the core of the monofilament fiber is made of permethrin-containing highly crystalline homopolypropylene (PP) resin, and the sheath of the monofilament fiber is made of polyethylene terephthalate (PET). ) Resin. Using this monofilament fiber, an insect-resistant yarn of a composite fiber (75 denier, 24 monofilament) was produced. The content of permethrin with respect to the obtained insect-resistant thread was 1% by mass.

(Production of knit)
Using the obtained insect-resistant thread, a knitted fabric of a thin leno structure composed of three threads was manufactured. Here, among the three threads A to C shown in FIG. 2, the obtained insect-resistant thread is used as the thread C. As the threads A and B, a composite fiber (75 denier, 24 monofilament) composed of a monofilament fiber having a single layer structure was used. A monofilament fiber having a single-layer structure is produced using a polyethylene terephthalate (PET) resin.

(Comparative example 1)
The insect-resistant thread obtained in Example 1 was used as the three threads constituting the leno tissue. Next, a knitted fabric of a leno structure was produced using three insect-resistant threads.

(Reference example 1)
As the three yarns constituting the leno structure, a yarn made of polyethylene terephthalate (PET) resin was used. These yarns are composite fibers (75 denier, 24 monofilaments) composed of a plurality of monofilament fibers (single-layer structure) made of PET resin. Next, a knitted fabric of a leno structure was produced using the three yarns.

(Evaluation method of insect resistance)
The knitted fabrics of Example 1, Comparative Example 1, and Reference Example 1 were used as insect-proof nets to evaluate insect-proof functions. The evaluation method of the insect control function is as follows.

A screen frame (frame size: 43 cm × 37 cm, insect screen size: 34 cm × 33 cm) on which each insect net was installed was installed outside the house, and the number of insects staying in each insect net for more than 5 seconds was visually measured. Here, the insect-proof nets of Example 1 and Reference Example 1 were placed side by side in the same place for 5 days. In addition, the insect nets of Comparative Example 1 and Reference Example 1 were placed side by side in the same place for 5 days. In addition, the period (month and day) when the insect nets of Example 1 and Reference Example 1 were placed was different from the period (month and day) when the insect nets of Comparative Example 1 and Reference Example 1 were placed.

The measurement of the number of insects was performed three times a day at a determined time (10 o'clock, 15 o'clock, 17:30). In each measurement day, when the total number of insects staying on the insect net for more than 5 seconds is 1 or more, the evaluation of the insect resistance is ×, and when the total number of insects staying on the insect net for more than 5 seconds is 0, Evaluation was ○.

(Evaluation results of insect resistance)
The measurement results of the number of insects are shown in FIGS. 4 and 5. FIG. 4 is a measurement result about the insect net of Example 1 and Reference Example 1, and FIG. 5 is a measurement result about the insect net of Comparative Example 1 and Reference Example 1. In each of FIG. 4 and FIG. 5, the vertical axis represents the number of insects (referred to as the number of insects) staying for 5 seconds or more, and the horizontal axis represents the measurement day and the measurement time.

Regarding Reference Example 1, although the number of insects was zero according to the measurement time, the total number of insects for one day was one or more. Regarding Example 1 and Comparative Example 1, the number of insects was 0 on all measurement days regardless of the measurement time. From this, it can be seen that the insect-proof net system of Example 1 and Comparative Example 1 has excellent insect-proof function. In addition, according to the evaluation method described above, the evaluation results shown in Table 1 below were obtained.

(Evaluation method of weather resistance)
The insect-resistant nets of Example 1 and Comparative Example 1 were evaluated for weather resistance. The weather resistance test method is performed in a laboratory, and the insect net is irradiated with ultraviolet rays under the conditions specified in JIS A1415 (2013). Before and after the weather resistance test, the tensile strength [N] and the elongation [%] of the insect net were measured by a tensile test based on JIS L1096. In the weather resistance test, two hypothetical elapsed years (2 years and 6 years) were set by changing the irradiation time of ultraviolet rays.

(Evaluation result of weather resistance)
Regarding the insect screens of Example 1 and Comparative Example 1 before the weather resistance test, the ratio of tensile strength (Example 1 / Comparative Example 1) to the ratio of elongation (Example 1 / Comparative Example 1) It is shown in Table 2 below. As is known from Table 2 below, the tensile strength of the insect-proof net of Example 1 is twice the tensile strength of the insect-proof net of Comparative Example 1. In addition, the elongation rate of the insect-proof net of Example 1 was 1.3 times that of the insect-proof net of Comparative Example 1.

On the other hand, regarding Example 1 and Comparative Example 1, the strength retention rate of the tensile strength of the insect net and the extension retention rate of the elongation of the insect net were calculated.

The strength retention rate refers to the ratio of the tensile strength of the insect net after the weather resistance test to the tensile strength of the insect net before the weather resistance test. Before and after the weather resistance test, if the tensile strength of the insect net does not change, the strength retention rate becomes 100 [%]. On the other hand, due to the deterioration of the insect net over time, when the tensile strength of the insect net is reduced, the strength retention rate is lower than 100 [%].

The elongation retention refers to the ratio of the elongation of the insect net before the weather resistance test to the elongation of the insect net after the weather resistance test. Before and after the weather resistance test, if the elongation of the insect net does not change, the elongation retention is 100 [%]. On the other hand, due to the age deterioration of the insect net, when the elongation rate of the insect net is reduced, the elongation retention rate is lower than 100 [%].

FIG. 6 shows the calculation results of the intensity retention ratios for Example 1 and Comparative Example 1 under two assumed elapsed years (2 years and 6 years). In FIG. 6, the vertical axis is the strength retention rate, and the horizontal axis is the assumed elapsed years. According to FIG. 6, it can be seen that the insect-repellent net of Example 1 has a lower strength retention rate than the insect-repellent net of Comparative Example 1.

In the insect screen of Comparative Example 1, it is assumed that when the elapsed years reach 2 years, the strength retention rate decreases extremely to about 40%. However, in the insect screen of Example 1, it is assumed that the elapsed years reach 2 years The strength retention rate is still above 80%. In addition, when the number of lapsed years reaches 6 years, the strength retention rate with respect to Example 1 is 67%, and the strength retention rate with Comparative Example 1 is 25%. Thereby, according to the insect-proof net of Example 1, it becomes easy to suppress the fall of the tensile strength.

FIG. 7 shows the calculation results of the elongation retention rate in Example 1 and Comparative Example 1 under two assumed elapsed years (2 years and 6 years). In FIG. 7, the vertical axis is the elongation retention rate, and the horizontal axis is the assumed elapsed years. According to FIG. 7, it can be seen that the insect repellent net of Example 1 is less likely to decrease the stretch retention rate than the insect repellent net of Comparative Example 1.

In the insect screen of Comparative Example 1, it is assumed that the elongation retention rate decreases extremely to about 20% when the elapsed years reach 2 years. However, in the insect screen of Example 1, it is assumed that the elapsed years reach 2 years. The elongation retention rate is still above 80%. In addition, when the number of lapsed years reaches 6 years, it is assumed that the stretch retention rate of Example 1 is 54%, and the stretch retention rate of Comparative Example 1 is 8%. Thereby, according to the insect-proof net of Example 1, it becomes easy to suppress the fall of the tensile strength.

1‧‧‧ monofilament fiber

2‧‧‧ core

3‧‧‧ sheath

4‧‧‧ insect repellent

[Fig. 1] A diagram showing a tissue of Leno.

[Fig. 2] Fig. 2 is a knitting diagram showing three threads constituting a tissue of Leno.

3 is a cross-sectional view of a monofilament fiber having a core-sheath structure.

FIG. 4 is a graph showing the relationship between the number of insects staying on the knitted fabrics of Example 1 and Reference Example 1 and the measurement time.

5 is a graph showing the relationship between the number of insects staying on the knitted fabrics of Comparative Example 1 and Reference Example 1 and the measurement time.

[Fig. 6] Fig. 6 is a graph showing the relationship between the strength retention rate and the assumed elapsed years for the knitted fabrics of Example 1 and Comparative Example 1.

[Fig. 7] Fig. 7 is a graph showing the relationship between the elongation retention rate and the assumed elapsed years for the knitted fabrics of Example 1 and Comparative Example 1.

Claims (6)

A knitted fabric is a knitted fabric formed by a plurality of threads, which is characterized in that: Among the plurality of filaments, a part of the plurality of filaments is composed of a plurality of monofilament fibers, and is a composite fiber containing an insecticide. The aforementioned knitted fabric according to claim 1, wherein the aforementioned knitted fabric has a tulle structure. The knitted fabric according to claim 2, wherein the part of the number of threads is a thread other than the chain-like knitting thread in the tissue. The knitted fabric of any one of claims 1 to 3, wherein The monofilament fiber system has a core-sheath structure including a core portion formed of a thermoplastic resin containing the insect repellent, and a sheath portion formed of a thermoplastic resin covering the core portion. The knitted fabric according to claim 4, wherein a weight ratio of the core portion and the sheath portion is 1: 9 to 9: 1. The knitted fabric according to any one of claims 1 to 5, wherein the aforementioned knitted fabric is used as a material for an insect-resistant product.