JP2005253368A - Insect proof net - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a woven and knitted material for an insect proof net made of a polyester causing less deterioration due to ultraviolet light by using a sheath-core type fusing filament. <P>SOLUTION: This insect proof net is formed of the sheath-core type fusing filaments having a sheath-core area ratio of 50:50 to 90:10 wherein core components comprise a polyester containing 0.3-5.0 wt.% of an organic ultraviolet light-absorbing agent based on the weight of the core components, and sheath components comprise a polyester with a low melting point, and the intersections of the woven and knitted material are bonded with heat. The organic ultraviolet light-absorbing agent preferably comprises a triazine-based compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an insect net used for agriculture and horticulture.

  In agriculture, protecting crops from pests has been a challenge for many years. Conventional pest control measures include insecticide killing with pesticides, prevention of pest infestation with coating materials, and elimination of pests with repellents. Among them, the development of agricultural chemicals has greatly progressed in recent decades, and it has become possible to exterminate pests on agricultural crops and has become widespread. However, the use of pesticides greatly increased the yield, but it caused many problems such as the destruction of ecosystems and the natural environment, and adverse effects on the human body. Therefore, in recent years, agricultural chemicals that are harmless to the environment and the human body have been researched and developed, but long-term accumulation and chronic toxicity have not yet been completely solved.

  In recent years, awareness of food and health has increased, and organic farm products without pesticides have been widely demanded. Therefore, as one of the conventional pest-control measures that do not use pesticides, a method of covering crops with a net and preventing the pests from flying in and out has come into wide use. The net is mainly made of synthetic fibers in order to maintain durability against natural environments such as rain and wind. However, synthetic fibers are deteriorated by ultraviolet rays emitted from the sun, and there is a problem that the breaking strength is lowered.

  In Patent Documents 1 and 2 and the like, insect repellent nets in which fabric intersections made of heat-fusible fibers are heat-sealed are proposed. Although there is no misalignment of the opening of the fabric by heat-sealing, there is a drawback in that when it is used outdoors, the strength is reduced by ultraviolet rays and it cannot be used for a long time. In patent document 3, the insect net which heat-bonds the intersection of the woven or knitted fabric made of heat-adhesive fibers and contains an ultraviolet absorber is proposed. However, the kneading of the UV absorber into the entire yarn not only has to be added in a large amount, but also the efficiency is deteriorated, and the breaking strength of the yarn is lowered due to a decrease in melt viscosity caused by kneading. Furthermore, Patent Document 4 proposes a covering sheet in which a nonwoven fabric using core-sheath fibers is fused. However, non-woven fabrics are not preferred because the amount of sunlight applied to the crops is reduced and the air permeability is deteriorated, so that the inside is easily stuffy.

Japanese Patent Laid-Open No. 10-44273 JP 2000-217497 A JP 2000-217446 A JP 7-303426 A

  An object of the present invention is to provide a woven or knitted fabric for insect repellent nets using a core-sheath-type fused filament made of polyester with less ultraviolet deterioration, which solves the above problems.

The above-mentioned problem is that the core-sheath area ratio is 50:50, in which the core component contains a polyester containing an organic ultraviolet absorber in an amount of 0.3% to 5.0% based on the weight of the core component, and the sheath component has a low melting point polyester. This is solved by an insect repellent net comprising a core-sheath type filament of ˜90: 10, wherein the intersection of the woven or knitted fabric is thermally bonded.

  According to the present invention, it is possible to obtain a core-sheath type fused fiber having good spinning operability and little UV degradation, preventing misalignment by heat-sealing a fabric woven and knitted, and without using pesticides, pests. It is possible to provide an insect net that can prevent the intrusion of the insect.

Hereinafter, the present invention will be described in detail.
The fiber for the insect net used in the present invention needs to be a core-sheath type filament. By adopting the core-sheath type, an insect repellent net having both excellent ultraviolet durability and fusion performance can be obtained. In the case of a single type, in order to obtain sufficient UV durability, a large amount of UV absorber must be kneaded, and as a result, the breaking strength of the fiber decreases, which is not preferable. In addition, a multifilament and a monofilament can be used for a filament.

  In the core-sheath filament, both the core and the sheath need to be polyester. Polyester has good dimensional stability and water resistance and is suitable for insect nets. If any one of the core and sheath is a polymer other than polyester, the adhesion between the core and the sheath will deteriorate due to long-term use, and peeling will occur and the breaking strength will be reduced.

  Examples of the polyester used include aromatic polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), and aliphatic polyesters such as polyethylene succinate and polycaprolactone. It is done. Among these, PET is particularly preferably used from the viewpoints of convenience of melt spinning, production cost, and the like.

  The core component of the core-sheath filament needs to contain an organic compound-based ultraviolet absorber. The ultraviolet absorber has an effect of suppressing deterioration of physical properties of the polymer by absorbing the wavelength in the ultraviolet region and converting it into harmless heat energy. Inorganic UV absorbers tend to aggregate particles during melt spinning, making uniform dispersion difficult, making it difficult to stabilize performance.

  Examples of organic ultraviolet absorbers include benzotriazole compounds, triazine compounds, and benzophenone compounds, and many are commercially available. In general, since an organic ultraviolet absorber is easily sublimated or volatilized, an ultraviolet absorber having as high a heat resistance as possible is preferable. In particular, from the viewpoint of heat resistance and compatibility with polyester, triazine compounds are preferably used in the insect net of the present invention. The main triazine compounds include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol.

  In addition, it is necessary to make a ultraviolet absorber contain 0.3%-5.0% with respect to a core component weight, Preferably it is 0.5%-3.0%. If it is less than 0.3%, the amount of the UV absorber is too small, and the polymer deterioration becomes remarkable when exposed to sunlight. On the other hand, if it exceeds 5.0%, the performance will reach its peak and the UV absorber will be wasted, and the content will increase so much that the melt viscosity of the polyester will decrease, and the break strength of the core-sheath filament will decrease, The burst strength of the insect repellent net will be reduced.

The ultraviolet absorber must be contained in the core component. Impregnation by post-processing is not preferable because it will fall off due to rain when it is used as an insect repellent net. On the other hand, if it is contained in the sheath component, it volatilizes when the woven fabric is fused, and the performance deteriorates.

  The intrinsic viscosity of the polyester as the core component is preferably 0.60 or more, particularly preferably 0.64 or more. When it is 0.60 or more, the breaking strength of the core-sheath filament increases.

  As the core-sheath filament, it is sufficient that the breaking strength is 3.0 cN / dtex or more, and particularly preferably 4.0 cN / dtex. When it is 3.0 cN / dtex or more, a strong insect net can be obtained which is resistant to external impacts.

  When the core-sheath filament is woven or knitted and used as an insect repellent net, the sheath component needs to be a low-melting polyester in order to prevent misalignment of the woven / knitted intersection. The low melting point polyester is preferably isophthalic acid copolymerized PET having good spinnability. The copolymerization ratio is not particularly limited, but the copolymerization ratio is preferably such that the difference in melting point is 30 ° C. or more with respect to the polyester as the core component. Within this range, the intersection can be bonded with a sufficient amount of heat without melting the core component.

  The cross-sectional shape of the core-sheath filament is not particularly limited, but is preferably circular and the core-sheath shape is preferably concentric. The core-sheath area ratio needs to be 50:50 to 90:10, particularly preferably 60:40 to 80:20. When the core area ratio is less than 50%, the breaking strength of the core-sheath filament decreases. On the other hand, if it exceeds 90%, it is not preferable because the fusion of the fabric intersection becomes insufficient due to the decrease in the sheath area.

  The fineness of the core-sheath filament is not particularly limited, but 50 to 100 dtex is preferable from the viewpoint of convenience and durability as an insect repellent net. Within this range, a strong insect net with moderate rigidity can be obtained.

  When the core-sheath filament is used outdoors as an insect repellent net, it is necessary that the strength decrease due to ultraviolet rays is small. In order to easily perform this light resistance evaluation, there is a method of measuring the breaking strength and bursting strength after irradiation using a strong xenon type fade meter. The core-sheath filament used in the insect repellent net of the present invention preferably has a breaking strength retention after exposure for 48 hours of 60% or more, particularly preferably 70% or more, as measured by a strong xenon fade meter. Within this range, there is little deterioration due to ultraviolet rays even under natural exposure, so that a durable insect-proof net can be obtained.

  The insect net of the present invention needs to be a woven or knitted fabric. Non-woven fabrics are not preferred because when the insect-proof sheet is used, the amount of sunlight applied to the crops is reduced, and the air permeability becomes poor and the inside tends to be stuffy. In addition, the woven or knitted fabric needs to be heat-sealed. Without heat fusion, misalignment is likely to occur during prolonged natural exposure, and pests are more likely to enter.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to the Example described below.

A. Measurement of intrinsic viscosity Intrinsic viscosity was measured in a thermostatic bath at 20 ° C. using phenol / tetrachloroethane (volume ratio 6/4) as a solvent.

B. Measurement of Breaking Strength of Core-Sheath Filament Breaking strength was measured according to JIS-L-1013 method, sample yarn length 20cm, constant speed tensile speed 20c.
It calculated | required on the conditions of m / min.

C. Measurement of burst strength of insect repellent net The burst strength was determined as a sample of 15 cm × 15 cm according to the JIS-L-1096A method (Murlen type method).

D. Fade meter light resistance evaluation Fade meter light resistance evaluation was performed by attaching a filament sample or a net sample in an environment with a black panel temperature of 63 ° C and a humidity of 50% using the “Strong Energy Xenon Fade Meter SC700-FA” manufactured by Suga Test Instruments For 48 hours. Thereafter, the film was taken out and the breaking strength or bursting strength was measured.

E. Preparation of Kneaded PET for Core Component To PET having an intrinsic viscosity of 0.68, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[( 1% by weight of hexyl) oxy] -phenol was added to PET and melt extruded at 270 ° C. with a vented twin-screw kneader to obtain a kneaded PET for the core component. The obtained chip had an intrinsic viscosity of 0.64 and a melting point of 257 ° C.

F. Production of copolymer PET for sheath component Low-melting PET was obtained by copolymerization PET according to a conventionally known DMT method. That is, with respect to 100 mol% of ethylene glycol, 75 mol% of DMT and 25 mol% of dimethyl isophthalate were charged into the polymerization tank, and calcium acetate monohydrate was 0.09 (wt% / ester) as a transesterification catalyst. Then, 0.03 (wt% / ester) of manganese acetate tetrahydrate was added to conduct transesterification. In the next polycondensation reaction, 0.04 (wt% / polymer) of antimony trioxide was added as a polymerization catalyst, and 0.043 (wt% / polymer) of trimethyl phosphate was added as a thermal stabilizer, and the polymerization temperature was 275 ° C. and 133 Pa or less. This was carried out under high vacuum conditions to obtain a low melting point copolymerized PET. The obtained chip had an intrinsic viscosity of 0.64 and a melting point of 193 ° C.

G. Production of Core-Sheath Filament Using a kneaded PET obtained in (E.) above as the core component and the copolymerized PET described in (F.) above as the sheath component, a conventionally known core-sheath composite spinning method was followed. That is, the core-sheath area ratio was 60:40, the undrawn yarn was wound up at a spinning temperature of 290 ° C. and a spinning speed of 1000 m / min, and then aged at room temperature for 1 day. Then, it extended | stretched at the hot roller 85 degreeC and the plate heater temperature 150 degreeC, and obtained the core-sheath-type multifilament of 84 dtex / 8 filament.

H. Production of Insect-proof Net Using the core-sheath filament described in (G.), a plain woven fabric of 30 pieces / 2.54 cm (1 inch) was obtained with a luther loom. The opening of this plain woven fabric opening was about 0.8 mm. Next, this plain woven fabric was treated at 220 ° C. for 2 minutes using a pin tenter type heat setter, and the woven fabric intersection was fused to obtain an insect repellent net.

Example 1
(G.) A core-sheath filament was prepared according to the description. The core-sheath filament had a breaking strength of 3.34 cN / dtex. When this core-sheath filament was evaluated for light resistance according to the description in (D.), the breaking strength after 48 hours exposure was 2.40 cN / dtex, and the breaking strength retention was 71.9%. Next, an insect net was prepared according to the description in (H.). The burst strength of this insect repellent net was 416 kPa. When the insect net was evaluated for light resistance according to the description in (D.), the burst strength after exposure for 48 hours was 299 kPa, and the burst strength retention was 72.9%. When this net was used as an insect repellent net for cabbage, the net did not tear or tear even after 6 months of use because of its low UV degradation, and had good durability. In addition, there was no pest damage to the cabbage because it did not cause misalignment.

<Performance evaluation of insect repellent net with and without UV absorber>
Comparative Example 1
A core-sheath filament was prepared according to the description in (G.) except that homo-PET having an intrinsic viscosity of 0.68 was used as the core component. The core-sheath filament had a breaking strength of 3.51 cN / dtex. Furthermore, when the fade meter light resistance evaluation was performed, the breaking strength after 48 hours exposure was 1.74 cN / dtex, and the breaking strength retention was 49.6%. Next, an insect net was prepared according to the description in (H.). The burst strength of this insect repellent net was 410 kPa. The insect net was evaluated for light resistance according to the description in (D.). As a result, the burst strength after exposure for 48 hours was 230 kPa, and the burst strength retention rate was 56.1%. Furthermore, when used as an insect repellent net for cabbage, as in Example 1, the net did not contain an ultraviolet blocking agent, so that the ultraviolet ray deteriorated severely, and tearing or tearing occurred even when caught on a plant. Therefore, it could not be used as an insect repellent net.

<Performance evaluation of insect net by the presence or absence of heat fusion of sheath>
Comparative Example 2
A core-sheath filament was prepared according to the description in (G.) except that homo-PET having an intrinsic viscosity of 0.68 was used as the sheath component. The breaking strength of the core-sheath filament was 3.75 cN / dtex. When the fade resistance was further evaluated, the breaking strength after 48 hours exposure was 2.27 cN / dtex, and the breaking strength retention was 60.5%. Next, an insect repellent net was prepared according to the description in (H.) except that heat fusion treatment was performed. The burst strength of this insect repellent net was 422 kPa. When the insect net was evaluated for light resistance according to the description in (D.), the burst strength after exposure for 48 hours was 301 kPa, and the burst strength retention was 71.3%. Further, as in Example 1, it was used as an insect repellent net for cabbage. Although there was little UV deterioration of the net, the intersections of the fabrics were not adhered, so misalignment occurred in places due to wind and rain, and the insect repellent effect was low.

<Evaluation of insect net performance by changing the amount of UV absorber added>
A core-sheath filament was prepared according to the method described in (G.), and at that time, as shown in Table 1, the addition amount of the ultraviolet absorber was variously changed and evaluated.

  In Comparative Example 3, since the amount of the ultraviolet absorber added is too large, the fracture strength retention rate by the fade meter evaluation is as high as 83.2%, but the melt viscosity of the core component is significantly reduced during spinning, and the fracture strength is 2. It was as low as 10 cN / dtex. When this core-sheath type filament was made into an insect repellent net, it was easily broken and could not be used, so the insect repellent net performance evaluation was poor (x). On the other hand, Examples 1 to 5 according to the present invention were good in both breaking strength retention and insect net evaluation. In Examples 1, 3, and 4 in particular, the addition amount of the ultraviolet absorber is optimal, so that there is little decrease in viscosity during melt spinning and the breaking strength is high. When using insect repellent nets, they were all excellent without tearing or tearing even after 6 months of use.

<Performance evaluation of insect nets by changing the core-sheath area ratio>
(G.) A core-sheath filament was prepared according to the method described, and the core-sheath area ratio was variously changed as shown in Table 2 for evaluation.

  In Comparative Example 4, since the core area was too small, the breaking strength was lowered. When this was produced and used in the same manner as described in Example 1, it became a net lacking in strength and could not be used. Therefore, the insect net performance evaluation was poor (x). Moreover, since the comparative example 5 had too little sheath area, the heat | fever fusion | bonding of the textile intersection was inadequate. As a result, the insect repellent net using this produced misalignment at the intersection due to strong wind and rain during use, the insect repellent effect was low and could not be used, and the insect net performance evaluation was poor (x). On the other hand, in Examples 1 and 6 to 8 according to the present invention, since the core-sheath ratio was optimal, the breaking strength was high and the heat fusion was sufficient, so that the performance as an insect repellent net was also good. .

  The insect net of the present invention is particularly suitable for use in agriculture and horticulture.

Claims (3)

A core-sheath area ratio of 50:50 to 90:10, in which a polyester containing 0.3% to 5.0% of an organic ultraviolet absorber as a core component and a low-melting-point polyester as a sheath component is arranged. An insect repelling net comprising a core-sheath filament, wherein the intersection of the woven or knitted fabric is thermally bonded. 2. The insect repellent net according to claim 1, wherein the organic ultraviolet absorbent contained in the core component of the core-sheath filament is a triazine compound. The low melting point polyester of the sheath component of the core-sheath filament is copolymerized polyethylene terephthalate copolymerized with isophthalic acid, and the difference in melting point from the core component is 30 ° C or more. Insect net.