A functional nonwoven fabric for agricultural use and its preparation method

Abstract

This invention belongs to the field of nonwoven fabric preparation technology, and specifically relates to a functional nonwoven fabric for agricultural use and its preparation method. The raw materials for the agricultural functional nonwoven fabric include polypropylene, rare earth-organic composite, nano-titanium dioxide, and calcium stearate. This invention uses polypropylene as a raw material to prepare a nonwoven fabric that is soft and breathable. Furthermore, the introduction of rare earth-organic composite and nano-titanium dioxide further optimizes its UV resistance, thereby improving plant growth and development in agricultural mulching applications.

Description

Technical Field

[0001] This invention belongs to the field of nonwoven fabric preparation technology, and relates to a functional nonwoven fabric for agricultural use and its preparation method. Background Technology

[0002] Existing agricultural mulch films have several problems. For example, polyethylene (PE) films have poor heat retention, polyvinyl chloride (PVC) films release toxic gases during processing and disposal, and PI films generate steam that can burn seedlings and require manual perforation. Furthermore, traditional agricultural mulch films cannot regulate light quality, which is detrimental to plant growth and development. Based on these issues, there has been considerable research on agricultural mulch films. Chinese invention patent CN101141874B provides an agricultural and horticultural land cover film that absorbs near-infrared rays from sunlight by coating one side with a white light-reflecting layer containing white light-reflecting material and an infrared light-absorbing layer containing infrared-absorbing material particles. However, the coating is prone to peeling or failure during long-term use, and it cannot effectively resist ultraviolet rays when the light conversion effect weakens. Long-term ultraviolet radiation may damage plant DNA and inhibit auxin synthesis, or induce free radical accumulation and accelerate leaf senescence.

[0003] Chinese invention patent application CN117510923A discloses a carbon-based light-converting agent / thermoplastic polymer light-converting agricultural film with light wavelength conversion and anti-ultraviolet aging properties, and its preparation method. It converts ultraviolet and green light in sunlight, which have no effect on plant growth, into blue and red light required for plant photosynthesis, etc. However, the preparation of carbon-based light-converting agents is relatively complex and still needs further optimization. These problems need to be further studied and solved. Summary of the Invention

[0004] The purpose of this invention is to provide a functional nonwoven fabric for agricultural use and its preparation method. This invention uses polypropylene as raw material to prepare nonwoven fabric, which has the characteristics of being soft and breathable. On this basis, rare earth-organic composite and nano titanium dioxide are introduced to further optimize the anti-ultraviolet performance, thereby being able to replace existing agricultural covering films and improve plant growth and development.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An agricultural functional nonwoven fabric is made from the following raw materials: by weight, it comprises 85-105 parts polypropylene, 8-16 parts rare earth-organic composite, 5-11 parts nano titanium dioxide with an average particle size of 20-30 nm, and 2-4 parts calcium stearate.

[0007] Furthermore, the preparation method of the rare earth-organic complex includes the following steps:

[0008] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0009] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0010] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0011] X4. Spray the γ-aminopropyltriethoxysilane solution evenly onto the surface of powder A obtained in step X3, then spray a protective liquid and perform heat curing treatment to obtain powder B with surface modification.

[0012] X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0013] Further, the mass ratio of europium chloride hexahydrate, 1H-benzimidazole-5-carboxylic acid and solvent is 1:(3-3.3):(40-50).

[0014] Further, in step X1, the solvent is obtained by mixing deionized water, ethanol and N,N-dimethylformamide in a mass ratio of 1:(0.7-0.8):(0.6-0.7).

[0015] Furthermore, in step X2, the pH is adjusted to 7.6-8 using a 1.6-2 mol / L NaOH solution; the reflux temperature is 85°C, and the reflux time is 10-12 h.

[0016] Furthermore, in step X3, a 0.22μm PTEE filter membrane is used for filtration.

[0017] Further, in step X4, the mass ratio of powder A, γ-aminopropyltriethoxysilane solution, and protective liquid is 1:(1.06-1.12):(0.11-0.15).

[0018] The γ-aminopropyltriethoxysilane solution is composed of γ-aminopropyltriethoxysilane and ethanol in a mass ratio of 1:(8.8-9.2);

[0019] The protective solution is composed of PEG-200, 0.1-0.2 mol / L citric acid solution, and ethanol in a mass ratio of 1:(0.005-0.007):(3.5-4.1).

[0020] Furthermore, in step X4, the thickness of the γ-aminopropyltriethoxysilane solution sprayed is 3-3.4 nm; the thickness of the protective liquid sprayed is 9-11 nm; and the thermosetting treatment is curing at 70°C for 30-40 min.

[0021] Further, in step X5, the mass ratio of powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution is 1:(0.2-0.26):(0.05-0.07):(14.5-15.5).

[0022] The ethanol-acetone solution is composed of ethanol and acetone in a mass ratio of (3.8-4.2):1;

[0023] The steps for ultrasonic mixing are as follows: first, stir at 500-600 rpm for 8-12 minutes, then set the ultrasonic frequency to 25-45 kHz and the ultrasonic power to 250-350 W, and then mix ultrasonically for 15-25 minutes.

[0024] This invention also provides a method for preparing a functional nonwoven fabric for agricultural use, comprising the following steps:

[0025] Step Z1: Mix polypropylene, rare earth-organic composite, nano-titanium dioxide with an average particle size of 20-30 nm, and calcium stearate evenly to obtain a mixture.

[0026] Step Z2: Add the mixture obtained in step Z1 to a screw mixer and heat it to 210-220℃, and stir at 60-80 rpm for 5-10 minutes to obtain a molten mixture;

[0027] Step Z3: The molten mixture obtained in step Z2 is spun into filaments through a spinneret with a spinneret orifice size of 0.2-0.25 mm. The filament bundle is then stretched by a stretching fan at a speed of 90 m / s. The stretched filament bundle is laid on the mesh curtain of a web forming machine and then hot-pressed into shape by a hot press at a hot rolling temperature of 130-140℃ and a pressure of 70-80 MPa to obtain the shaped nonwoven fabric.

[0028] Step Z4: After trimming the edges of the shaped nonwoven fabric obtained in step Z3 and rolling it into a roll, it is then bonded by a heat bonding machine to obtain the functional nonwoven fabric for agricultural use.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention uses polypropylene as raw material to prepare nonwoven fabric, and forms a matrix network with both rigidity and flexibility by compounding it with flax fiber, which ensures mechanical strength and improves air permeability, and has the characteristics of softness and breathability. On this basis, rare earth-organic composite and nano titanium dioxide are introduced to further optimize the anti-ultraviolet performance, so as to replace agricultural covering film and improve plant growth and development.

[0031] 2. This invention introduces a rare earth-organic complex, in which europium chloride hexahydrate is a rare earth metal salt with excellent optical properties. It can effectively absorb short-wavelength light such as ultraviolet light and convert ultraviolet light into a spectrum suitable for plant growth, such as red light, through fluorescence emission. Simultaneously, 1H-benzimidazole-5-carboxylic acid is added to facilitate the interaction of nitrogen atoms with europium ions (Eu). 3+ They form complexes to enhance the light emission, stability, and compatibility of rare earth elements;

[0032] Based on this, a γ-aminopropyltriethoxysilane solution was used for surface modification to form an aminosilane layer (modification layer) on the surface of the complex, which improved dispersibility and stability, provided more active sites for subsequent reactions, improved the absorption capacity of rare earth-organic complexes for ultraviolet light, and promoted the photoconversion capacity of rare earth-organic complexes.

[0033] Next, the superimposed protective liquid forms a stable dual protection mechanism to prevent the modified layer from falling off or failing during subsequent processing and use; while 7-hydroxycoumarin emits blue fluorescence under ultraviolet light, and nano-titanium dioxide has a strong ultraviolet light shielding effect. The synergistic complex further weakens ultraviolet light and exerts an anti-ultraviolet effect, thereby improving plant growth and development in agricultural mulch film applications. Detailed Implementation

[0034] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0035] In all embodiments and comparative examples of this invention, polypropylene was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; europium chloride hexahydrate and 1H-benzimidazole-5-carboxylic acid were purchased from Shanghai Yuanye Biotechnology Co., Ltd.; γ-aminopropyltriethoxysilane was purchased from Wuhan Smike Biotechnology Co., Ltd.; 7-hydroxycoumarin was purchased from Hubei Xinyuhong Biomedical Technology Co., Ltd.; ethanol and acetone were purchased from Dongguan Kaiyu Chemical Co., Ltd.; PEG-200 (polyethylene glycol 200), nano titanium dioxide, calcium stearate, N,N-dimethylformamide, citric acid, and NaOH were purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0036] Example 1

[0037] A functional nonwoven fabric for agricultural use, the raw materials of which, by weight, include 85 parts polypropylene, 8 parts rare earth-organic composite, 5 parts nano-titanium dioxide with an average particle size of 20 nm, and 2 parts calcium stearate.

[0038] The preparation method of the rare earth-organic complex includes the following steps:

[0039] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0040] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0041] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0042] X4. Spray the γ-aminopropyltriethoxysilane solution evenly onto the surface of powder A obtained in step X3, then spray a protective liquid and perform heat curing treatment to obtain powder B with surface modification.

[0043] X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0044] The mass ratio of europium chloride hexahydrate, 1H-benzimidazole-5-carboxylic acid, and solvent is 1:3:40.

[0045] In step X1, the solvent is obtained by mixing deionized water, ethanol and N,N-dimethylformamide in a mass ratio of 1:0.7:0.6.

[0046] In step X2, the pH is adjusted to 7.6 using a 1.6 mol / L NaOH solution; reflux refers to refluxing at 85°C for 10 hours.

[0047] In step X3, filtration is performed using a 0.22 μm PTEE membrane.

[0048] In step X4, the mass ratio of powder A, γ-aminopropyltriethoxysilane solution, and protective solution is 1:1.06:0.11; wherein, the γ-aminopropyltriethoxysilane solution is composed of γ-aminopropyltriethoxysilane and ethanol in a mass ratio of 1:8.8; the protective solution is composed of PEG-200, 0.1mol / L citric acid solution, and ethanol in a mass ratio of 1:0.005:3.5.

[0049] In step X4, the thickness of the γ-aminopropyltriethoxysilane solution spray is 3 nm; the thickness of the protective liquid spray is 9 nm; and the thermosetting treatment is to cure at 70°C for 30 min.

[0050] In step X5, the mass ratio of powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution is 1:0.2:0.05:14.5; the ethanol-acetone solution is composed of ethanol and acetone in a mass ratio of 3.8:1; the ultrasonic mixing steps are as follows: first, stir at 500 rpm for 8 minutes, then set the ultrasonic frequency to 25 kHz and the ultrasonic power to 250 W, and then ultrasonically mix for 15 minutes.

[0051] Based on the above, the preparation method of this functional nonwoven fabric for agricultural use includes the following steps:

[0052] Step Z1: Mix polypropylene, rare earth-organic composite, nano-titanium dioxide with an average particle size of 20nm and calcium stearate evenly to obtain a mixture.

[0053] Step Z2: Add the mixture obtained in step Z1 to a screw mixer and heat it to 210°C. Stir at 60 rpm for 5 minutes to obtain a molten mixture.

[0054] Step Z3: The molten mixture obtained in step Z2 is spun into filaments through a spinneret with a spinneret orifice size of 0.2 mm. The filament bundle is then stretched by a stretching fan at a speed of 90 m / s. The stretched filament bundle is laid on the mesh curtain of a web forming machine and then hot-rolled by a hot press at a hot rolling temperature of 130℃ and a pressure of 70 MPa to obtain the shaped nonwoven fabric.

[0055] Step Z4: After trimming the edges of the shaped nonwoven fabric obtained in step Z3 and rolling it into a roll, it is then bonded by a heat bonding machine to obtain the functional nonwoven fabric for agricultural use.

[0056] Example 2

[0057] An agricultural functional nonwoven fabric, the raw materials of which, by weight, include 89 parts polypropylene, 10 parts rare earth-organic composite, 6.8 parts nano-titanium dioxide with an average particle size of 22 nm, and 2.5 parts calcium stearate.

[0058] The preparation method of the rare earth-organic complex includes the following steps:

[0059] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0060] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0061] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0062] X4. Spray the γ-aminopropyltriethoxysilane solution evenly onto the surface of powder A obtained in step X3, then spray a protective liquid and perform heat curing treatment to obtain powder B with surface modification.

[0063] X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0064] The mass ratio of europium chloride hexahydrate, 1H-benzimidazole-5-carboxylic acid, and solvent is 1:3.08:41.

[0065] In step X1, the solvent is obtained by mixing deionized water, ethanol and N,N-dimethylformamide in a mass ratio of 1:0.72:0.63.

[0066] In step X2, the pH is adjusted to 7.7 using a 1.7 mol / L NaOH solution; reflux refers to refluxing at 85°C for 10.5 h.

[0067] In step X3, filtration is performed using a 0.22 μm PTEE membrane.

[0068] In step X4, the mass ratio of powder A, γ-aminopropyltriethoxysilane solution, and protective solution is 1:1.07:0.12; wherein, the γ-aminopropyltriethoxysilane solution is composed of γ-aminopropyltriethoxysilane and ethanol in a mass ratio of 1:8.9; the protective solution is composed of PEG-200, 0.1mol / L citric acid solution, and ethanol in a mass ratio of 1:0.005:3.7.

[0069] In step X4, the thickness of the γ-aminopropyltriethoxysilane solution sprayed is 3.1 nm; the thickness of the protective liquid sprayed is 9.5 nm; and the thermosetting treatment is to cure at 70°C for 33 min.

[0070] In step X5, the mass ratio of powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution is 1:0.21:0.055:14.8; the ethanol-acetone solution is composed of ethanol and acetone in a mass ratio of 3.9:1; the ultrasonic mixing steps are as follows: first, stir at 520 rpm for 9 min, then set the ultrasonic frequency to 30 kHz and the ultrasonic power to 280 W, and then ultrasonically mix for 18 min.

[0071] Based on the above, the preparation method of this functional nonwoven fabric for agricultural use includes the following steps:

[0072] Step Z1: Mix polypropylene, rare earth-organic composite, nano-titanium dioxide with an average particle size of 22nm and calcium stearate evenly to obtain a mixture.

[0073] Step Z2: Add the mixture obtained in step Z1 to a screw mixer and heat it to 212°C. Stir at 65 rpm for 6.5 min to obtain a molten mixture.

[0074] Step Z3: The molten mixture obtained in step Z2 is spun into filaments through a spinneret with a spinneret orifice size of 0.2 mm. The filament bundle is then stretched by a stretching fan at a speed of 90 m / s. The stretched filament bundle is laid on the mesh curtain of a web forming machine and then hot-rolled by a hot press at a hot rolling temperature of 133℃ and a pressure of 73 MPa to obtain the shaped nonwoven fabric.

[0075] Step Z4: After trimming the edges of the shaped nonwoven fabric obtained in step Z3 and rolling it into a roll, it is then bonded by a heat bonding machine to obtain the functional nonwoven fabric for agricultural use.

[0076] Example 3

[0077] A functional nonwoven fabric for agricultural use, the raw materials of which, by weight, include 95 parts polypropylene, 12 parts rare earth-organic composite, 8 parts nano-titanium dioxide with an average particle size of 25 nm, and 3 parts calcium stearate.

[0078] The preparation method of the rare earth-organic complex includes the following steps:

[0079] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0080] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0081] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0082] X4. Spray the γ-aminopropyltriethoxysilane solution evenly onto the surface of powder A obtained in step X3, then spray a protective liquid and perform heat curing treatment to obtain powder B with surface modification.

[0083] X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0084] The mass ratio of europium chloride hexahydrate, 1H-benzimidazole-5-carboxylic acid, and solvent is 1:3.15:45.

[0085] In step X1, the solvent is obtained by mixing deionized water, ethanol and N,N-dimethylformamide in a mass ratio of 1:0.75:0.65.

[0086] In step X2, the pH is adjusted to 7.8 using a 1.8 mol / L NaOH solution; reflux refers to refluxing at 85°C for 11 hours.

[0087] In step X3, filtration is performed using a 0.22 μm PTEE membrane.

[0088] In step X4, the mass ratio of powder A, γ-aminopropyltriethoxysilane solution, and protective solution is 1:1.09:0.13; wherein, the γ-aminopropyltriethoxysilane solution is composed of γ-aminopropyltriethoxysilane and ethanol in a mass ratio of 1:9; the protective solution is composed of PEG-200, 0.15mol / L citric acid solution, and ethanol in a mass ratio of 1:0.006:3.8.

[0089] In step X4, the thickness of the γ-aminopropyltriethoxysilane solution spray is 3.2 nm; the thickness of the protective liquid spray is 10 nm; and the thermosetting treatment is to cure at 70°C for 35 min.

[0090] In step X5, the mass ratio of powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution is 1:0.23:0.06:15; the ethanol-acetone solution is composed of ethanol and acetone in a mass ratio of 4:1; the ultrasonic mixing steps are as follows: first, stir at 550 rpm for 10 min, then set the ultrasonic frequency to 35 kHz and the ultrasonic power to 300 W, and then ultrasonically mix for 20 min.

[0091] Based on the above, the preparation method of this functional nonwoven fabric for agricultural use includes the following steps:

[0092] Step Z1: Mix polypropylene, rare earth-organic composite, nano-titanium dioxide with an average particle size of 25nm, and calcium stearate evenly to obtain a mixture.

[0093] Step Z2: Add the mixture obtained in step Z1 to a screw mixer and heat it to 215°C. Stir at 70 rpm for 7.5 min to obtain a molten mixture.

[0094] Step Z3: The molten mixture obtained in step Z2 is spun into filaments through a spinneret with a spinneret orifice size of 0.23 mm. The filament bundle is then stretched by a stretching fan at a speed of 90 m / s. The stretched filament bundle is laid on the mesh curtain of a web forming machine and then hot-rolled by a hot press at a hot rolling temperature of 135℃ and a pressure of 75 MPa to obtain the shaped nonwoven fabric.

[0095] Step Z4: After trimming the edges of the shaped nonwoven fabric obtained in step Z3 and rolling it into a roll, it is then bonded by a heat bonding machine to obtain the functional nonwoven fabric for agricultural use.

[0096] Example 4

[0097] A functional nonwoven fabric for agricultural use, the raw materials of which, by weight, include 98 parts polypropylene, 14 parts rare earth-organic composite, 10 parts nano-titanium dioxide with an average particle size of 27 nm, and 3.5 parts calcium stearate.

[0098] The preparation method of the rare earth-organic complex includes the following steps:

[0099] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0100] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0101] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0102] X4. Spray the γ-aminopropyltriethoxysilane solution evenly onto the surface of powder A obtained in step X3, then spray a protective liquid and perform heat curing treatment to obtain powder B with surface modification.

[0103] X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0104] The mass ratio of europium chloride hexahydrate, 1H-benzimidazole-5-carboxylic acid, and solvent is 1:3.25:46.

[0105] In step X1, the solvent is obtained by mixing deionized water, ethanol and N,N-dimethylformamide in a mass ratio of 1:0.77:0.68.

[0106] In step X2, the pH is adjusted to 7.9 using a 1.9 mol / L NaOH solution; reflux refers to refluxing at 85°C for 11.5 h.

[0107] In step X3, filtration is performed using a 0.22 μm PTEE membrane.

[0108] In step X4, the mass ratio of powder A, γ-aminopropyltriethoxysilane solution, and protective solution is 1:1.1:0.14; wherein, the γ-aminopropyltriethoxysilane solution is composed of γ-aminopropyltriethoxysilane and ethanol in a mass ratio of 1:9.1; the protective solution is composed of PEG-200, 0.2mol / L citric acid solution, and ethanol in a mass ratio of 1:0.007:4.

[0109] In step X4, the thickness of the γ-aminopropyltriethoxysilane solution spray is 3.3 nm; the thickness of the protective liquid spray is 10.5 nm; and the thermosetting treatment is to cure at 70°C for 38 min.

[0110] In step X5, the mass ratio of powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution is 1:0.25:0.065:15.2; the ethanol-acetone solution is composed of ethanol and acetone in a mass ratio of 4.1:1; the ultrasonic mixing steps are as follows: first, stir at 560 rpm for 11 min, then set the ultrasonic frequency to 40 kHz and the ultrasonic power to 320 W, and then ultrasonically mix for 22 min.

[0111] Based on the above, the preparation method of this functional nonwoven fabric for agricultural use includes the following steps:

[0112] Step Z1: Mix polypropylene, rare earth-organic composite, nano-titanium dioxide with an average particle size of 28 nm, and calcium stearate evenly to obtain a mixture.

[0113] Step Z2: Add the mixture obtained in step Z1 to a screw mixer and heat it to 216°C. Stir at 75 rpm for 8.5 min to obtain a molten mixture.

[0114] Step Z3: The molten mixture obtained in step Z2 is spun into filaments through a spinneret with a spinneret orifice size of 0.25 mm. The filament bundle is then stretched by a stretching fan at a speed of 90 m / s. The stretched filament bundle is laid on the mesh curtain of a web forming machine and then hot-rolled by a hot press at a hot rolling temperature of 138℃ and a pressure of 78 MPa to obtain the shaped nonwoven fabric.

[0115] Step Z4: After trimming the edges of the shaped nonwoven fabric obtained in step Z3 and rolling it into a roll, it is then bonded by a heat bonding machine to obtain the functional nonwoven fabric for agricultural use.

[0116] Example 5

[0117] A functional nonwoven fabric for agricultural use, the raw materials of which, by weight, include 105 parts polypropylene, 16 parts rare earth-organic composite, 11 parts nano-titanium dioxide with an average particle size of 30 nm, and 4 parts calcium stearate.

[0118] The preparation method of the rare earth-organic complex includes the following steps:

[0119] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0120] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0121] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0122] X4. Spray the γ-aminopropyltriethoxysilane solution evenly onto the surface of powder A obtained in step X3, then spray a protective liquid and perform heat curing treatment to obtain powder B with surface modification.

[0123] X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0124] The mass ratio of europium chloride hexahydrate, 1H-benzimidazole-5-carboxylic acid, and solvent is 1:3.3:50.

[0125] In step X1, the solvent is obtained by mixing deionized water, ethanol and N,N-dimethylformamide in a mass ratio of 1:0.8:0.7.

[0126] In step X2, the pH is adjusted to 8 using a 2 mol / L NaOH solution; reflux refers to refluxing at 85°C for 12 hours.

[0127] In step X3, filtration is performed using a 0.22 μm PTEE membrane.

[0128] In step X4, the mass ratio of powder A, γ-aminopropyltriethoxysilane solution, and protective solution is 1:1.12:0.15; wherein, the γ-aminopropyltriethoxysilane solution is composed of γ-aminopropyltriethoxysilane and ethanol in a mass ratio of 1:9.2; the protective solution is composed of PEG-200, 0.2mol / L citric acid solution, and ethanol in a mass ratio of 1:0.007:4.1.

[0129] In step X4, the thickness of the γ-aminopropyltriethoxysilane solution sprayed is 3.4 nm; the thickness of the protective liquid sprayed is 11 nm; and the thermosetting treatment is to cure at 70°C for 40 min.

[0130] In step X5, the mass ratio of powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution is 1:0.26:0.07:15.5; the ethanol-acetone solution is composed of ethanol and acetone in a mass ratio of 4.2:1; the ultrasonic mixing steps are as follows: first, stir at 600 rpm for 12 min, then set the ultrasonic frequency to 45 kHz and the ultrasonic power to 350 W, and then ultrasonically mix for 25 min.

[0131] Based on the above, the preparation method of this functional nonwoven fabric for agricultural use includes the following steps:

[0132] Step Z1: Mix polypropylene, rare earth-organic composite, nano-titanium dioxide with an average particle size of 30nm and calcium stearate evenly to obtain a mixture.

[0133] Step Z2: Add the mixture obtained in step Z1 into a screw mixer and heat it to 220°C. Stir at 80 rpm for 10 minutes to obtain a molten mixture.

[0134] Step Z3: The molten mixture obtained in step Z2 is spun into filaments through a spinneret with a spinneret orifice size of 0.25 mm. The filament bundle is then stretched by a stretching fan at a speed of 90 m / s. The stretched filament bundle is laid on the mesh curtain of a web forming machine and then hot-rolled by a hot press at a hot rolling temperature of 140℃ and a pressure of 80 MPa to obtain the shaped nonwoven fabric.

[0135] Step Z4: After trimming the edges of the shaped nonwoven fabric obtained in step Z3 and rolling it into a roll, it is then bonded by a heat bonding machine to obtain the functional nonwoven fabric for agricultural use.

[0136] Comparative Example 1

[0137] Based on Example 3, the rare earth-organic complex was removed and replaced with an equal weight of europium chloride hexahydrate, while other conditions remained the same as in Example 3.

[0138] Comparative Example 2

[0139] Based on Example 3, the rare earth-organic complex was removed and replaced with an equal weight of 7-hydroxycoumarin, while other conditions remained the same as in Example 3.

[0140] Comparative Example 3

[0141] Based on Example 3, the rare earth-organic complex was removed and replaced with equal weights of europium chloride hexahydrate and 7-hydroxycoumarin, wherein the mass ratio of europium chloride hexahydrate to 7-hydroxycoumarin was 1:0.23, and other conditions remained the same as in Example 3.

[0142] Comparative Example 4

[0143] Based on Example 3, the rare earth-organic composite was removed and replaced with an equal weight of nano-titanium dioxide with an average particle size of 25 nm, while other conditions remained the same as in Example 3.

[0144] Comparative Example 5

[0145] Based on Example 3, the difference lies in that the preparation method of the rare earth-organic complex includes the following steps:

[0146] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0147] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0148] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0149] X4. A γ-aminopropyltriethoxysilane solution is uniformly sprayed onto the surface of powder A obtained in step X3, followed by spraying a protective liquid and heat curing treatment to obtain surface-modified powder B. Powder B is a rare earth-organic composite.

[0150] Comparative Example 6

[0151] Based on Example 3, the difference lies in that the preparation method of the rare earth-organic complex includes the following steps:

[0152] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0153] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0154] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0155] X4. After ultrasonically mixing the powder A obtained in step X3, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0156] Comparative Example 7

[0157] Based on Example 3, the difference lies in that the preparation method of the rare earth-organic complex includes the following steps:

[0158] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0159] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0160] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0161] X4. Spray the protective liquid evenly onto the surface of powder A obtained in step X3, then spray γ-aminopropyltriethoxysilane solution, and perform heat curing treatment to obtain powder B with surface modification.

[0162] X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0163] Comparative Example 8

[0164] Based on Example 3, the difference lies in that the preparation method of the rare earth-organic complex includes the following steps:

[0165] X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A;

[0166] X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution.

[0167] X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A.

[0168] X4. Spray the γ-aminopropyltriethoxysilane solution evenly onto the surface of powder A obtained in step X3, and perform heat curing treatment to obtain powder B with surface modification.

[0169] X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain a rare earth-organic complex.

[0170] In summary, the agricultural functional nonwoven fabrics prepared in Examples 1-5 and Comparative Examples 1-8 were used as samples. The UV resistance of the samples was tested according to the national standard GB / T 24218.3-2010. The test data included the tensile strength of the nonwoven fabric before UV irradiation and the tensile strength after 240h of 340nm UV irradiation. The test results are shown in Table 1.

[0171] Table 1. Results of fracture strength test on the samples

[0172]

[0173] As shown in Table 1, the agricultural functional nonwoven fabric prepared by this invention has good UV resistance and can still maintain good tensile strength under UV irradiation, showing good application prospects in agricultural mulching.

[0174] In addition, to verify the effect of the samples (agricultural functional nonwoven fabric) on crops, melons were used as an example for mulching. The agricultural functional nonwoven fabrics prepared in Examples 1-5 and Comparative Examples 1-8 were used as samples. Each group of samples covered 30 Elizabethan melon plants (the melon seedlings used in this test were healthy seedlings from the same batch with similar growth). The effect of agricultural functional nonwoven fabric on plant growth was evaluated by recording the number of early maturity days and the yield increase (mean) of each group of melons. The sample verification results are shown in Table 2.

[0175] Table 2. Validation results of the samples in melon cultivation.

[0176]

[0177] As shown in Table 2, the agricultural functional nonwoven fabric prepared by the present invention can effectively promote early maturity of plants and achieve increased yield while reducing the impact of ultraviolet rays on plants.

Claims

1. A functional nonwoven fabric for agricultural use, characterized in that: The agricultural functional nonwoven fabric is made from the following raw materials: by weight, it includes 85-105 parts polypropylene, 8-16 parts rare earth-organic composite, 5-11 parts nano titanium dioxide with an average particle size of 20-30 nm, and 2-4 parts calcium stearate. The preparation method of the rare earth-organic complex includes the following steps: X1. Mix europium chloride hexahydrate and solvent, and stir at 60°C until clear to obtain solution A; X2. Add 1H-benzimidazole-5-carboxylic acid to solution A obtained in step X1, adjust the pH, and reflux under nitrogen atmosphere to obtain the reaction solution. X3. Cool the reaction solution obtained in step X2 to 50°C, reduce the pressure and filter, wash to remove unreacted solvent, and dry under vacuum at 60°C for 24 hours to obtain powder A. X4. Spray the γ-aminopropyltriethoxysilane solution evenly onto the surface of powder A obtained in step X3, then spray a protective liquid and perform heat curing treatment to obtain powder B with surface modification. X5. After ultrasonically mixing powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution obtained in step X4, the mixture is dried by rotary evaporation at 60°C to obtain rare earth-organic complex. The mass ratio of europium chloride hexahydrate, 1H-benzimidazole-5-carboxylic acid, and solvent is 1:(3-3.3):(40-50). In step X4, the mass ratio of powder A, γ-aminopropyltriethoxysilane solution, and protective solution is 1:(1.06-1.12):(0.11-0.15); the γ-aminopropyltriethoxysilane solution is composed of γ-aminopropyltriethoxysilane and ethanol in a mass ratio of 1:(8.8-9.2); the protective solution is composed of PEG-200, 0.1-0.2 mol / L citric acid solution, and ethanol in a mass ratio of 1:(0.005-0.007):(3.5-4.1).

2. The functional nonwoven fabric for agricultural use according to claim 1, characterized in that: In step X1, the solvent is obtained by mixing deionized water, ethanol and N,N-dimethylformamide in a mass ratio of 1:(0.7-0.8):(0.6-0.7).

3. The functional nonwoven fabric for agricultural use according to claim 1, characterized in that: In step X2, the pH is adjusted to 7.6-8 using a 1.6-2 mol / L NaOH solution; the reflux temperature is 85°C, and the reflux time is 10-12 h.

4. The functional nonwoven fabric for agricultural use according to claim 1, characterized in that: In step X3, filtration is performed using a 0.22μm PTEE filter membrane.

5. The functional nonwoven fabric for agricultural use according to claim 1, characterized in that: In step X4, the thickness of the γ-aminopropyltriethoxysilane solution spray is 3-3.4 nm; the thickness of the protective liquid spray is 9-11 nm; and the thermosetting treatment is to cure at 70°C for 30-40 min.

6. The functional nonwoven fabric for agricultural use according to claim 1, characterized in that: In step X5, the mass ratio of powder B, 7-hydroxycoumarin, polyvinylpyrrolidone, and ethanol-acetone solution is 1:(0.2-0.26):(0.05-0.07):(14.5-15.5); the ethanol-acetone solution is composed of ethanol and acetone in a mass ratio of (3.8-4.2):1; the ultrasonic mixing steps are as follows: first, stir at 500-600 rpm for 8-12 minutes, then set the ultrasonic frequency to 25-45 kHz and the ultrasonic power to 250-350 W, and then ultrasonically mix for 15-25 minutes.

7. A method for preparing an agricultural functional nonwoven fabric as described in any one of claims 1-6, characterized in that: The preparation method includes the following steps: Step Z1: Mix polypropylene, rare earth-organic composite, nano-titanium dioxide with an average particle size of 20-30 nm, and calcium stearate evenly to obtain a mixture. Step Z2: Add the mixture obtained in step Z1 to a screw mixer and heat it to 210-220℃, and stir it at 60-80 rpm for 5-10 minutes to obtain a molten mixture; Step Z3: The molten mixture obtained in step Z2 is spun into filaments through a spinneret with a spinneret orifice size of 0.2-0.25 mm. The filament bundle is then stretched by a stretching fan at a speed of 90 m / s. The stretched filament bundle is laid on the mesh curtain of a web forming machine and then hot-pressed into shape by a hot press at a hot rolling temperature of 130-140℃ and a pressure of 70-80 MPa to obtain the shaped nonwoven fabric. Step Z4: After trimming the edges of the shaped nonwoven fabric obtained in step Z3 and rolling it into a roll, it is then bonded by a heat bonding machine to obtain the functional nonwoven fabric for agricultural use.

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