Insect-proof net

Abstract

The invention relates to the technical field of gardening insect prevention, in particular to an insect-proof net which is composed of a plurality of warp yarns and a plurality of weft yarns. The edge of the insect-proof net is provided with a sealing edge which covers the end part of the weft yarn; a plurality of indentations are arranged on the sealing edge; the warp yarns and the weft yarns are prepared by mixing 0.5-4 parts by mass of an anti-ultraviolet additive and 90-130 parts by mass of modified PET (Polyethylene Terephthalate) and then carrying out melt spinning. According to the insect-proof net, the problem of burrs after the insect-proof net is cut can be solved, the edge of the insect-proof net is smoother, the installation safety and the use comfort are improved, meanwhile, the ventilation performance, the light transmission performance and the flame retardant performance are good, and the structural shape is more stable when the insect-proof net is used.

Description

Technical Field

[0001] The present invention relates to the technical field of horticultural pest control, and particularly to an insect-proof net. Background Art

[0002] As a physical protection device for isolating insects from the target space, the technical development of insect-proof nets has always revolved around the optimization of material properties, the innovation of structural design, and the integration of functions. In the early days, insect-proof nets were mostly woven from natural fibers or metal wires, achieving the insect-proof effect through physical barriers. However, such products have significant defects such as easy corrosion, poor air permeability, and weak anti-aging ability. With the progress of polymer materials science, synthetic fibers represented by polyethylene, polypropylene, and polyethylene terephthalate have gradually become the mainstream base materials. By optimizing the weaving process, precise control of the mesh size can be achieved, effectively intercepting small insects while ensuring ventilation and light transmission performance.

[0003] In the agricultural field, the application of insect-proof nets has expanded from single greenhouse protection to a three-dimensional protection system for open-field planting. Traditional flat insect-proof nets have problems such as limited coverage and insufficient wind resistance. Modern technology has introduced a three-dimensional weaving structure and a flexible support system, enabling the protection net to adapt to complex terrains and form a dynamic protection barrier. Although significant progress has been made in insect-proof net technology, existing products still face several challenges, and research on insect-proof nets is constantly ongoing. For example, CN109023571B discloses "a composite fiber and its application in a rice insect-proof net", which is composed of a fiber matrix material, chitosan microparticles, copper stearate, and europium ions, and can prevent rice planthoppers and at the same time increase the intensity of the red spectrum, improving rice yield.

[0004] However, most of the current structures of insect-proof nets are accordion-like structures. In order to support the stability of the accordion-like structure, the warp is often woven with two wire meshes or two layers of mesh sheets stacked to prepare the insect-proof net. The ventilation performance of this method is greatly reduced, and due to the increase in thickness, the light transmittance of the mesh sheet decreases, which is not conducive to sunlight entering the house and thus affects the growth of crops.

[0005] Therefore, it is urgent to develop an insect-proof net with a stable structure and high light transmittance after being unfolded. Summary of the Invention

[0006] The main object of the present invention is to provide an insect-proof net. After being made into an accordion-like insect-proof net, it has a more stable unfolded structure, higher light transmittance, excellent flame retardant effect, and the edge of a single insect-proof net sheet is smooth and does not scratch the hand, making it convenient to handle.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] On the one hand, the present invention provides an insect-proof net, which is composed of a plurality of warp yarns and a plurality of weft yarns; the edge of the insect-proof net contains a hem, which is wrapped around the end of the weft yarn; a plurality of indentations are provided on the hem; by mass parts, the warp yarns and the weft yarns are prepared by melt spinning after mixing 0.5 to 4 parts of an ultraviolet-resistant additive and 90 to 130 parts of modified PET.

[0009] In some embodiments, the ends of each weft yarn are melt-bonded to each other.

[0010] In some embodiments, the hem is a thin film or a webbing.

[0011] In some embodiments, the preparation method of the modified PET includes the following steps: under an inert protective gas atmosphere, terephthalic acid, ethylene glycol, a functional polyol and a catalyst are mixed, pressurized to 0.01 to 0.03 MPa, heated to 220 to 250 °C, and reacted for 2 to 4 h. Subsequently, the pressure is reduced to 2300 to 2500 Pa by vacuum pumping, and the reaction is continued for 1.2 to 1.8 h. Then, the temperature is raised to 260 to 280 °C, the pressure is maintained at 50 to 100 Pa, and the mixture is continuously stirred at a constant temperature for 1.5 to 2 h to obtain the modified PET.

[0012] In some embodiments, the mass ratio of the terephthalic acid, ethylene glycol and the functional polyol is 1:(1 to 1.3):(0.2 to 0.5).

[0013] In some embodiments, the functional polyol includes the structure shown in the following formula I:

[0014]

[0015] In some embodiments, the preparation method of the functional polyol includes the following steps:

[0016] A1. Under an inert protective gas atmosphere, dissolve the first batch of cyanuric chloride in acetonitrile, cool it to -5 to 0 °C in an ice bath, add resorcinol, aniline and an acid-binding agent, and after adding, raise the temperature to room temperature and react for 5 to 7 h. Subsequently, add the second batch of cyanuric chloride and continue stirring for 5 to 7 h. After the reaction is completed, filter, concentrate under reduced pressure, and perform column chromatography to obtain the compound shown in formula II

[0017]

[0018] A2. Under an inert protective gas atmosphere, mix the compound shown in formula II in step A1 with toluene, cool it to -5 to 0 °C in an ice bath, add ethanolamine and an acid-binding agent, and stir at a constant temperature for 6 to 7 h. After the reaction is completed, filter, concentrate under reduced pressure, and perform column chromatography to obtain the functional polyol.

[0019] The warp and weft of the insect-proof net of the present application are both composed of a monofilament structure, which improves the air permeability of the insect-proof net. However, the applicant has found in the research that when the insect-proof net with a monofilament structure is made into a finished foldable insect-proof net, the monofilament cannot maintain the unfolded structure of the insect-proof net due to its poor rigidity, and a sagging phenomenon will occur, which affects the use and is not beautiful. In addition, the conventional PET has poor flame retardant properties, and there are safety hazards that may become a fuse during production or use.

[0020] The present application prepares a modified PET, which avoids the phenomenon of migration and precipitation caused by adding other ingredients and additives, and can also improve the structural stability, flame retardant properties and light transmittance of the insect-proof net. The reasons may be: first, the modified PET structure contains a small amount of hydroxyl groups, which can inhibit PET crystallization by self-hydrogen bond cross-linking, destroy the regularity of PET, reduce the scattering of light, and thus improve the light transmittance of the modified PET; second, the modified PET structure contains a large amount of triazine and phenyl structures, which synergistically form a π-π stacking effect, increase the rigidity of the modified PET, and thus improve the structural stability of the insect-proof net; third, the modified PET structure contains a large amount of N elements, which can decompose and produce nitrogen-containing gas when the modified PET burns, which can capture active free radicals, thereby reducing the combustion intensity and improving the flame retardant properties of the insect-proof net.

[0021] In some embodiments, in step A1, the molar ratio of the first batch of cyanuric chloride, aniline and resorcinol is 1:(1-1.2):(2.2-2.5).

[0022] In some embodiments, in step A1, the molar ratio of the second batch of cyanuric chloride to resorcinol is (1-1.3):1.

[0023] In some embodiments, in step A2, the molar ratio of the compound represented by formula II to ethanolamine is 1:(4-4.5).

[0024] In some embodiments, the acid binding agent is any one of triethylamine, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate.

[0025] In some embodiments, the width of the insect-proof net is 7 to 20 cm.

[0026] In some embodiments, the warp and weft yarns are monofilaments.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) The insect-proof net of the present invention is woven with a monofilament structure, and the edge of the insect-proof net is covered with the end of the weft yarn by edge sealing and fixed with bonding, which solves the problem of edge burrs after traditional cutting, makes the edge of the insect-proof net smoother, improves installation safety and comfort of use, and at the same time, the monofilament woven insect-proof net has better air permeability.

[0029] (2) The insect-proof net of the present invention is prepared by melt spinning a mixture of modified PET and an anti-ultraviolet additive, wherein the modified PET structure contains a small amount of hydroxyl, triazine and phenyl structures, and the hydroxyl group can hydrogen-bond cross-linking of the modified PET itself to inhibit PET crystallization, destroy the regularity of PET, reduce light scattering, and thus improve the light transmittance of the modified PET; and a large amount of triazine and phenyl structures synergistically form a π-π stacking effect, which increases the rigidity of the modified PET, thereby improving the structural stability of the insect-proof net; in addition, the modified PET structure contains a large amount of N element, which can decompose and produce nitrogen-containing gas when the modified PET burns, which can capture active free radicals, thereby reducing the combustion intensity and improving the flame retardant properties of the insect-proof net. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a partial schematic diagram of an insect-proof net in an embodiment of the present application;

[0031] Figure 2 The H NMR spectrum of the compound represented by Formula II in Preparation Example 1 of this application;

[0032] Figure 3 This is the H NMR spectrum of the functional polyol in Preparation Example 1 of this application;

[0033] Figure numerals: 1, edge banding; 2, warp yarn; 3, weft yarn; 4, indentation. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0035] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0036] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although this invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of this invention. Various improvements and variations can be made to the specific embodiments of the description of this invention without departing from the scope or spirit of this invention, which will be obvious to those skilled in the art. Other embodiments obtained from the description of this invention will be obvious to those skilled in the art. The description and examples of this application are merely exemplary.

[0037] It should be noted that operations such as "drying", "filtering", "stirring", etc. described in this invention are conventional operations for those skilled in the art and can be selected according to actual operations.

[0038] PET was purchased from Shenzhen GEM Optoelectronic Materials Co., Ltd.

[0039] Preparation Example 1

[0040] Refer to Figures 2 to 3 , the preparation method of the functional polyol, comprising the following steps:

[0041] A1. Under a N₂ atmosphere, dissolve 0.1 mol of cyanuric chloride in 200 mL of acetonitrile, cool the mixture to -3 °C in an ice bath, add 0.23 mol of resorcinol, 0.11 mol of aniline, and 0.6 mol of sodium bicarbonate. After the addition, warm the mixture to room temperature and react for 6 h. Then, add an additional 0.28 mol of cyanuric chloride and continue stirring for 6 h. After the reaction is completed, filter, concentrate under reduced pressure, and perform column chromatography to obtain the compound shown in Formula II. The proton nuclear magnetic resonance spectrum is shown in Figure 2

[0042]

[0043] A2. Under a N₂ atmosphere, mix 0.1 mol of the compound shown in Formula II in Step A1 with 300 mL of toluene, cool the mixture to -3 °C in an ice bath, add 0.42 mol of ethanolamine and 0.5 mol of sodium bicarbonate, and stir at a constant temperature for 6.5 h. After the reaction is completed, filter, concentrate under reduced pressure, and perform column chromatography to obtain the functional polyol, the structure of which is shown in Formula I. The proton nuclear magnetic resonance spectrum is shown in Figure 3

[0044]

[0045] Preparation Example 2

[0046] The preparation method of the functional polyol, comprising the following steps:

[0047] A1. Under N2 atmosphere, dissolve 0.1 mol of cyanuric chloride in 200 mL of acetonitrile, cool it to -3 °C in an ice bath, add 0.34 mol of resorcinol and 0.4 mol of sodium bicarbonate. After adding, warm it up to room temperature and react for 6 h. Then add an additional 0.28 mol of cyanuric chloride and continue stirring for 6 h. After the reaction is completed, filter, concentrate under reduced pressure, and perform column chromatography to obtain the compound shown in Formula III.

[0048]

[0049] A2. Under N2 atmosphere, mix 0.1 mol of the compound shown in Formula III from Step A1 with 300 mL of toluene, cool it to -3 °C in an ice bath, add 0.6 mol of ethanolamine and 0.62 mol of sodium bicarbonate, stir at a constant temperature for 6.5 h. After the reaction is completed, filter, concentrate under reduced pressure, and perform column chromatography to obtain the functional polyol, the structure of which is shown in Formula IV.

[0050]

[0051] Preparation Example 3

[0052] A preparation method of the functional polyol, the specific implementation manner is the same as that of Preparation Example 1, except that equimolar resorcinol is used instead of ethanolamine.

[0053] Preparation Example 4

[0054] A preparation method of the functional polyol, comprising the following steps:

[0055] A1. Under N2 atmosphere, dissolve 0.1 mol of cyanuric chloride in 200 mL of acetonitrile, cool it to -3 °C in an ice bath, add 0.23 mol of resorcinol, 0.11 mol of aniline and 0.6 mol of sodium bicarbonate. After adding, warm it up to room temperature and react for 6 h. After the reaction is completed, filter, concentrate under reduced pressure, and perform column chromatography to obtain the functional polyol, the structure of which is shown in Formula V.

[0056]

[0057] Preparation Example 5

[0058] A preparation method of modified PET, comprising the following steps: Under N2 atmosphere, mix 10 g of terephthalic acid, 12 g of ethylene glycol, 3 g of functional polyol and 0.06 g of antimony trioxide, pressurize to 0.02 MPa, heat up to 230 °C, react for 3 h. Then evacuate to a pressure of 2400 Pa and continue to react for 1.6 h. Then heat up to 270 °C, maintain the pressure at 70 Pa, and continue to stir at a constant temperature for 1.7 h to obtain modified PET.

[0059] Among them, the functional polyol is prepared from Preparation Example 1.

[0060] Preparation Example 6

[0061] The preparation method of modified PET is the same as that of Preparation Example 5, except that the functional polyol is prepared from Preparation Example 2.

[0062] Preparation Example 7

[0063] The preparation method of modified PET is the same as that of Preparation Example 5, except that the functional polyol is prepared from Preparation Example 3.

[0064] Preparation Example 8

[0065] The preparation method of modified PET is the same as that of Preparation Example 5, except that the functional polyol is prepared from Preparation Example 4.

[0066] Example 1

[0067] Refer to Figure 1 , this embodiment provides an insect-proof net, which is composed of a plurality of warp yarns 2 and a plurality of weft yarns 3; the edge of the insect-proof net contains a hemming 1, which is wrapped around the end of the weft yarn 3; a plurality of indentations 4 are provided on the hemming 1; the ends of each weft yarn 3 are melt-bonded together, the width of the insect-proof net is 12 cm, the hemming 1 is a film, and the warp yarns 2 and the weft yarns 3 are monofilaments.

[0068] By mass, the warp yarns 2 and the weft yarns 3 are prepared by mixing 2.5 parts of UV-1164 and 110 parts of modified PET and then melt-spinning.

[0069] Among them, the modified PET is prepared from Preparation Example 5.

[0070] Example 2

[0071] An insect-proof net is composed of a plurality of warp yarns 2 and a plurality of weft yarns 3; the edge of the insect-proof net contains a hemming 1, which is wrapped around the end of the weft yarn 3; a plurality of indentations 4 are provided on the hemming 1; the ends of each weft yarn 3 are melt-bonded together, the width of the insect-proof net is 7 cm, the hemming 1 is a film, and the warp yarns 2 and the weft yarns 3 are monofilaments.

[0072] By mass, the warp yarns 2 and the weft yarns 3 are prepared by mixing 0.5 part of UV-1164 and 90 parts of modified PET and then melt-spinning.

[0073] Among them, the modified PET is prepared from Preparation Example 5.

[0074] Example 3

[0075] An insect-proof net is composed of a plurality of warp yarns 2 and a plurality of weft yarns 3; the edge of the insect-proof net contains a sealing edge 1, which is wrapped around the end of the weft yarn 3; a plurality of indentations 4 are provided on the sealing edge 1; the ends of each weft yarn 3 are melt-bonded together, the width of the insect-proof net is 20 cm, the sealing edge 1 is a thin film, and the warp yarns 2 and the weft yarns 3 are monofilaments.

[0076] By mass fraction, the warp yarns 2 and the weft yarns 3 are prepared by melt spinning a mixture of 4 parts of UV-1164 and 130 parts of modified PET.

[0077] Among them, the modified PET is prepared by Preparation Example 5.

[0078] Example 4

[0079] An insect-proof net, the specific implementation manner is the same as that of Example 1, the difference is that the modified PET is prepared by Preparation Example 6.

[0080] Example 5

[0081] An insect-proof net, the specific implementation manner is the same as that of Example 1, the difference is that the modified PET is prepared by Preparation Example 7.

[0082] Example 6

[0083] An insect-proof net, the specific implementation manner is the same as that of Example 1, the difference is that the modified PET is prepared by Preparation Example 8.

[0084] Comparative Example 1

[0085] An insect-proof net, the specific implementation manner is the same as that of Example 1, the difference is that an equal mass fraction of PET is used instead of the modified PET.

[0086] Performance test:

[0087] (1) Elastic modulus: Cut the insect-proof net into 5 cm × 5 cm test pieces and test according to the ASTM D790 standard. The larger the elastic modulus, the stronger the rigidity of the insect-proof net;

[0088] (2) Flame retardant performance: Test the oxygen index of the insect-proof net according to GB / T2406-93;

[0089] Test the insect-proof nets of each example and comparative example according to the above test methods (1) to (2), and the test results are shown in Table 1.

[0090] Table 1

[0091] Elastic Modulus / GPa Oxygen Index / % Example 1 4.9 41.1 Example 2 4.6 40.5 Example 3 4.8 42.6 Example 4 5.7 41.8 Example 5 5.5 40.2 Example 6 4.5 36.5 Comparative Example 1 2.5 21.9

[0092] According to the data in Table 1, the insect-proof nets prepared in Examples 1 to 5 have a certain rigidity and a certain flame retardancy. In Example 6, due to the change in the structure of the functional polyol, the content of N element in the modified PET structure decreases, resulting in a decrease in the flame retardancy of the insect-proof net. In Comparative Example 1, due to the use of PET in equal mass parts instead of modified PET, the rigidity of the insect-proof net decreases, and the insect-proof net cannot maintain the accordion-like structure when it is unfolded and collapses, and the flame retardancy of the insect-proof net also decreases.

[0093] (3) Light transmittance: PET is used to produce PET films through a fully automatic vacuum rotary drum, an extruder, and a biaxial stretching unit. The film outlet temperature is controlled at 95 °C, the thickness is controlled at 0.2 mm, and the size is 120 mm × 120 mm. The light transmittance of the film is measured using a LAMBDA35 spectrophotometer.

[0094] The modified PET and PET in Preparation Examples 5 to 8 are tested according to the above method (3), and the test results are shown in Table 2.

[0095] Table 2

[0096] Light Transmittance / % PET 80.39 Preparation Example 5 98.24 Preparation Example 6 89.68 Preparation Example 7 92.33 Preparation Example 8 97.47

[0097] According to the data in Table 2, the modified PET prepared in Preparation Example 5 and Preparation Example 8 has a good light transmittance, which can allow more light to enter the room when the insect-proof net is used, and improve the growth of crops. In Preparation Example 6, due to the use of resorcinol instead of aniline, the content of active hydroxyl groups in the functional polyol structure increases, resulting in an excessive crosslinking density of the modified PET, thereby reducing the light transmittance of the modified PET. In Preparation Example 7, due to the use of equimolar resorcinol instead of ethanolamine, the content of rigid benzene ring structures in the modified PET structure increases, which exacerbates crystallization and microphase separation, thereby reducing the transparency of the modified PET.

[0098] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An insect-proof net, characterized in that, The insect-proof net is composed of multiple warp threads (2) and multiple weft threads (3); the edge of the insect-proof net contains a hemming (1) that wraps around the ends of the weft threads (3); multiple indentations (4) are provided on the hemming (1); by mass parts, the warp threads (2) and weft threads (3) are prepared by melt spinning after mixing 0.5 - 4 parts of anti-ultraviolet additive and 90 - 130 parts of modified PET.

2. The insect-proof net according to claim 1, wherein The ends of each weft thread (3) are melt-bonded together.

3. The insect-proof net according to claim 1, characterized in that, The hemming (1) is a film or a webbing.

4. The insect-proof net according to claim 1, characterized in that, The preparation method of the modified PET includes the following steps: Under an inert protective gas atmosphere, mix terephthalic acid, ethylene glycol, functional polyol, and a catalyst, pressurize to 0.01 - 0.03 MPa, heat up to 220 - 250 °C, react for 2 - 4 h, then evacuate to a pressure of 2300 - 2500 Pa, continue to react for 1.2 - 1.8 h, then heat up to 260 - 280 °C, maintain the pressure at 50 - 100 Pa, and continue to stir at a constant temperature for 1.5 - 2 h to obtain the modified PET.

5. The insect-proof net according to claim 4, characterized in that, The functional polyol includes the structure shown in the following formula Ⅰ:

6. The insect-proof net according to claim 5, characterized in that, The preparation method of the functional polyol includes the following steps: A1. Under an inert protective gas atmosphere, dissolve the first batch of cyanuric chloride in acetonitrile, cool down to -5 - 0 °C in an ice bath, add resorcinol, aniline, and a deacidifying agent, after adding, heat up to room temperature and react for 5 - 7 h, then add the second batch of cyanuric chloride and continue to stir for 5 - 7 h, after the reaction ends, filter, concentrate under reduced pressure, and perform column chromatography to obtain the compound shown in formula Ⅱ A2. Under an inert protective gas atmosphere, mix the compound shown in formula Ⅱ in step A1 with toluene, cool down to -5 - 0 °C in an ice bath, add ethanolamine and a deacidifying agent, stir at a constant temperature for 6 - 7 h, after the reaction ends, filter, concentrate under reduced pressure, and perform column chromatography to obtain the functional polyol.

7. The insect-proof net according to claim 6, characterized in that, In step A1, the molar ratio of the first batch of cyanuric chloride, aniline, and resorcinol is 1:(1 - 1.2):(2.2 - 2.5).

8. The insect-proof net according to claim 6, characterized in that, In step A2, the molar ratio of the compound shown in formula Ⅱ and ethanolamine is 1:(4 - 4.5).

9. The insect-proof net according to claim 1, characterized in that, The width of the insect-proof net is 7 - 20 cm.

10. The insect-proof net according to claim 1, characterized in that, The warp threads (2) and weft threads (3) are monofilaments.

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