Special tobacco fertilizer with multi-layer composite coated complete-element nutrients and preparation method of special tobacco fertilizer

Abstract

The invention discloses a multi-layer composite coated full-element nutrient tobacco special fertilizer and a preparation method thereof, the multi-layer composite coated full-element nutrient tobacco special fertilizer comprises potassium sulfate, ammonium sulfate, a controlled release film material and a compound fertilizer from inside to outside in sequence, the ammonium sulfate and the potassium sulfate, and the controlled release film material and the compound fertilizer are combined through a binder; the mass ratio of the potassium sulfate to the ammonium sulfate to the compound fertilizer is (150-250): (60-100): (15-30); the adhesive is one or more of a modified urea formaldehyde adhesive, a modified ammonium polyphosphate adhesive and a cyclodextrin adhesive. The special multi-layer composite coated full-element nutrient tobacco fertilizer prepared by the invention can provide nutrients required in the whole growth period for tobacco according to the nutrient requirements of the tobacco, and solves the problems that traditional tobacco fertilization is not matched with a nutrient absorption rule curve, and topdressing is labor-consuming and time-consuming.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a multi-layer composite coated full-nutrient fertilizer for tobacco and a preparation method thereof. Background Art

[0002] Tobacco needs to absorb a large amount of nutrients throughout its growth period to meet the needs of its normal growth and development and quality formation. However, the traditional method of fertilizing tobacco planting mainly relies on the one-time application of base fertilizer and 2-3 topdressing in the later stage. This fertilization mode has obvious disadvantages: on the one hand, the fertilizer utilization rate is low, resulting in a large amount of nutrients not being fully absorbed and lost, causing a waste of resources; on the other hand, frequent topdressing not only increases the cost of manpower and material resources, but also is time-consuming and labor-intensive, seriously affecting production efficiency. In addition, since tobacco transplanting often faces dry and rainy climatic conditions, and the rainy season arrives late, the early nutrient supply of tobacco plants is insufficient, affecting the early development of roots and leaves. In the later stage, with the arrival of the rainy season, the fertilizer supply gradually becomes sufficient, but it does not match the nutrient absorption law of tobacco, which easily causes the phenomenon of tobacco plants greedy for green and late maturity, affecting the maturity quality and final yield of tobacco leaves. This fertilizer application mode with unbalanced supply before and after seriously limits the improvement of tobacco production efficiency and quality.

[0003] Therefore, in order to solve the problems of low nutrient utilization rate, unbalanced supply and excessive labor consumption caused by traditional fertilization methods, the application of controlled-release fertilizers in tobacco planting is particularly important. Controlled-release fertilizers can achieve continuous release and balanced supply of nutrients through scientific nutrient release control technology, thereby meeting the nutrient needs of tobacco throughout its entire growth cycle. Unlike traditional fertilizers, controlled-release fertilizers can gradually release nutrients according to the fertilizer absorption law of tobacco at various growth stages, which not only ensures the rapid development of the early root system of tobacco plants, but also provides sufficient nutrients for tobacco plants in the middle and late stages, avoiding early growth restrictions caused by insufficient supply, or greedy green and late maturity caused by excessive supply. This stable and long-term fertilization characteristic not only greatly improves the utilization rate of fertilizers and reduces resource waste, but also reduces the frequency of field topdressing, saves manpower and material costs, and improves the overall efficiency of tobacco production. Therefore, it is urgent to develop a new controlled-release fertilizer that can meet the nutritional needs of tobacco throughout its physiological period at one time. Summary of the invention

[0004] In view of the above-mentioned prior art, the purpose of the present invention is to provide a multi-layer composite coated tobacco-specific fertilizer with full nutrients and a preparation method thereof. The fertilizer provides quick-acting nutrients from the outermost layer of composite fertilizer in the tobacco seedling stage, and the second layer of ammonium sulfate continuously provides controlled-release nitrogen fertilizer in the middle stage of tobacco growth. The potassium sulfate in the fertilizer core provides sufficient potassium fertilizer in the late stage of tobacco growth, so as to achieve one-time fertilization to meet the nutrients required by tobacco during the entire growth period. The present invention solves the problems of low fertilizer utilization rate, mismatch with the fertilizer absorption law of tobacco, and time-consuming, labor-intensive and labor-intensive traditional tobacco fertilization by wrapping potassium sulfate, ammonium sulfate and composite fertilizer together to form a tobacco-specific fertilizer with full multi-layer nutrient release.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] In a first aspect of the present invention, a multi-layer composite coated tobacco fertilizer with full nutrients is provided, which comprises potassium sulfate, ammonium sulfate, a controlled-release film material and a composite fertilizer from the inside to the outside, wherein the ammonium sulfate and the potassium sulfate, and the controlled-release film material and the composite fertilizer are bonded by a binder;

[0007] The mass ratio of potassium sulfate, ammonium sulfate and compound fertilizer is (150-250): (60-100): (15-30);

[0008] The adhesive is one or more of a modified urea formaldehyde adhesive, a modified ammonium polyphosphate adhesive, and a cyclodextrin adhesive;

[0009] The controlled release membrane material is obtained by reacting a first component and a second component, wherein the first component is one or more of grape seed oil polyol and cashew nut shell oil polyester polyol with amino group;

[0010] The second component is one or more of modified 1,5-pentamethylene diisocyanate, (R)-2-heptamethylene diisocyanate and L-lysine diisocyanate.

[0011] Preferably, the compound fertilizer is nitrate nitrogen fertilizer.

[0012] Preferably, the controlled release membrane is prepared by the following method:

[0013] The first component and the second component are mixed in a mass ratio of (0.8-1.5):(1-1.3), heated to 60-70° C., and then stirred evenly to remove bubbles to obtain a controlled release membrane material.

[0014] Preferably, the grape seed oil polyol is prepared by the following method:

[0015] Grape seed oil and pentaerythritol are mixed in a molar ratio of (1-2): (0.4-1) as a reaction substrate, 0.5%-5% of tetrabutyl titanate by weight of the total reaction substrate is added, and the mixture is reacted at 160-190° C. for 4-6 hours under nitrogen conditions. After the reaction, the precipitate is collected by filtration to obtain grape seed oil polyol.

[0016] The synthesis mechanism of grape seed oil polyol is to control the reaction molar ratio of grape seed oil and pentaerythritol so that the carboxyl group in grape seed oil and a hydroxyl group in pentaerythritol can undergo esterification reaction. The generated ester group has good hydrophobicity and at the same time, the hydroxyl value of grape seed oil is increased. Grape seed oil has good biodegradability and is environmentally friendly to the soil when used in controlled-release fertilizers.

[0017] Preferably, the amino-containing cashew nut shell oil polyester polyol is prepared by the following method:

[0018] Cashew nut shell oil polyol and dicarboxylic acid with amino group are mixed in a mass ratio of (100-120): (35-60) as a reaction substrate, 0.5%-5% of tetrabutyl titanate of the total mass of the reaction substrate is added, and the mixture is reacted at 190° C.-200° C. for 4-5 hours under nitrogen conditions, and then reacted at 220-230° C. under vacuum conditions for 3-4 hours. After the reaction, the precipitate is filtered and collected to obtain a cashew nut shell oil polyester polyol with amino group.

[0019] The mechanism of action of the amino cashew nut shell oil polyester polyol is that the amino cashew nut shell oil polyester polyol generated by esterification reaction contains a large number of ester groups and amino groups, and the amino groups react with isocyanate to form urea bonds. Both the ester groups and the urea bonds have good hydrophobic properties. Therefore, the controlled release effect of the controlled release fertilizer prepared by reacting the amino cashew nut shell oil polyester polyol with isocyanate is significantly improved.

[0020] Preferably, the dicarboxylic acid having an amino group is one or more of aminomalonic acid, 3-aminoglutaric acid and DL-2-aminosuberic acid.

[0021] Preferably, the modified 1,5-pentanediisocyanate is prepared by the following method:

[0022] 1,5-pentyl diisocyanate and 3-aminopropyl triethoxysilane are mixed in a molar ratio of (1-1.1):(0.2-0.4), and stirred at 40-50° C. for reaction for 1-2 hours to obtain modified 1,5-pentyl diisocyanate.

[0023] The mechanism of action of the modified 1,5-pentyl diisocyanate is to graft a small amount of 3-aminopropyltriethoxysilane onto the bio-based 1,5-pentyl diisocyanate, and then react the modified bio-based 1,5-pentyl diisocyanate with polyols to form a controlled release film material that is coated on the surface of the fertilizer particles. The grafted siloxane greatly improves the hydrophobic properties of the controlled release film material and improves the controlled release effect of the controlled release fertilizer.

[0024] Preferably, the modified urea-formaldehyde adhesive is prepared by the following method:

[0025] The pH of a 30-40% formaldehyde aqueous solution is adjusted to 7.5-8.5 with a potassium hydroxide aqueous solution to obtain a formaldehyde mixed solution;

[0026] Urea is added to a formaldehyde mixed solution, wherein the mass of the urea is 1-2 times the mass of the formaldehyde aqueous solution, and the mixture is reacted at 40-60° C. for 30-40 minutes. After the reaction, a phosphoric acid aqueous solution with a volume fraction of 0.05-0.15% is added until the pH value reaches 4-5, and then corn starch with a mass fraction of 1%-5% of the formaldehyde aqueous solution is added, and the mixture is reacted at 40-60° C. for 15-25 minutes. Then, the pH value is adjusted to 7.5-8.5 with a potassium hydroxide aqueous solution, and the mixture is reacted at 40-60° C. for 5-15 minutes to obtain a modified urea-formaldehyde adhesive, wherein the molecular weight of the modified urea-formaldehyde adhesive is 8000-12000.

[0027] Preferably, the concentration of the potassium hydroxide aqueous solution is 0.01-0.1 g / ml.

[0028] The modification mechanism of urea-formaldehyde adhesive is that when formaldehyde and urea react to form monomethylol urea under alkali-acid-alkali process conditions, corn starch is introduced, and the hydroxyl groups of the polyhydroxy products in the corn starch are connected with the active sites such as methylol groups in urea-formaldehyde through covalent bonds to form a graft copolymer product, forming a modified urea-formaldehyde adhesive. The modified urea-formaldehyde adhesive reduces the content of free formaldehyde, increases the viscosity of the urea-formaldehyde adhesive, and increases the slow-release performance of the nitrogen fertilizer.

[0029] Preferably, the modified ammonium polyphosphate binder is prepared by the following method:

[0030] Ammonium polyphosphate and polyethylene glycol are mixed in a mass ratio of 1:(1.2-1.3) as a reaction substrate, 0.5%-5% of tetrabutyl titanate based on the total mass of the reaction substrate is added, and the mixture is reacted at 130-170° C. for 4-6 hours under nitrogen conditions. After the reaction, the mixture is filtered and the precipitate is collected to obtain a modified ammonium polyphosphate adhesive.

[0031] The mechanism of the modified ammonium polyphosphate adhesive is that the phosphate group in the ammonium polyphosphate reacts with the hydroxyl group in the polyethylene glycol to form a phosphate ester. The phosphate ester has better bonding properties and has a hydrophobic ester group, which can better play a sustained-release role.

[0032] Preferably, the cyclodextrin adhesive is prepared by the following method:

[0033] Cyclodextrin, glycerol, polyethyl acrylate, sodium dodecylbenzene sulfonate and ethylene glycol dimethacrylate are uniformly mixed in a mass ratio of (1-1.1):(0.05-0.15):(0.1-0.3):(0.01-0.05):(0.02-0.1), and then water 1-2 times the mass of cyclodextrin is added, and the mixture is reacted at 40-60°C for 1-2h to obtain a cyclodextrin adhesive.

[0034] The second aspect of the present invention provides a method for preparing the above-mentioned multi-layer composite coated full-nutrient tobacco fertilizer, comprising the following steps:

[0035] (1) adding potassium sulfate to a granulator, and then sequentially adding a binder and ammonium sulfate to the potassium sulfate, wherein the amount of the binder added is 1-5% of the mass of the ammonium sulfate, to obtain a potassium sulfate fertilizer in which ammonium sulfate is wrapped with the binder;

[0036] (2) placing the ammonium sulfate-coated potassium sulfate fertilizer in a drum, adding a controlled-release film material for coating, so that the weight of the controlled-release film material accounts for 0.5-8% of the weight of the ammonium sulfate-coated potassium sulfate fertilizer, to obtain a composite coated controlled-release fertilizer;

[0037] (3) Put the composite coated controlled-release fertilizer into a granulator, add a binder and a composite fertilizer to the composite coated controlled-release fertilizer in sequence, wherein the amount of the binder added accounts for 1%-5% of the mass of the composite fertilizer, and obtain a multi-layer composite coated tobacco-specific fertilizer with full nutrients, and the particle diameter is 7-13 mm.

[0038] Beneficial effects of the present invention:

[0039] 1. The present invention prepares a multi-layer composite coated full-nutrient tobacco fertilizer, which can provide tobacco with the nutrients required for the entire growth period according to the nutrient requirements of tobacco, and solves the problem that the traditional fertilization of tobacco does not match the nutrient absorption law curve and topdressing is labor-intensive and time-consuming.

[0040] 2. The present invention solves the problem of simultaneous release of multiple nutrients in tobacco, and can achieve the release of potassium fertilizer in the later stage to meet the potassium fertilizer needs of tobacco in the later growth stage.

[0041] (3) The modified adhesive prepared by the present invention has better bonding effect and better slow-release performance when used for fertilizers.

[0042] (4) The controlled release membrane prepared by the present invention has better water resistance, biodegradability and environmental friendliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1: Product schematic diagram of the tobacco-specific fertilizer with multi-layer composite coating and full nutrients prepared by the present invention;

[0044] Figure 2 : Schematic diagram of the plane and cross section of the tobacco-specific fertilizer with multi-layer composite coating and full nutrients prepared in Example 1;

[0045] Figure 3 : The N release rate of the tobacco fertilizer with multi-layer composite coating and full nutrients prepared in Examples 1-3 and the N requirement curve of tobacco;

[0046] Figure 4 : The K release rate of the tobacco-specific fertilizer with multi-layer composite coating and full nutrients prepared in Examples 1-3 and the K requirement curve of tobacco. DETAILED DESCRIPTION

[0047] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0048] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below in conjunction with specific embodiments.

[0049] The test materials used in the examples of the present invention are all conventional test materials in the art and can be purchased through commercial channels.

[0050] The compound fertilizer used in the present invention is nitrate nitrogen fertilizer with a nutrient content of (N-P2O5-K2O 15-8-25).

[0051] The grape seed oil used in the present invention was purchased from Wuhan Kemik Biopharmaceutical Technology Co., Ltd.

[0052] The cashew nut shell oil polyol used in the present invention was purchased from Kalide Chemical Zhuhai Co., Ltd.

[0053] The controlled release membrane material used in the present invention is prepared by the following method:

[0054] (1) Preparation of grape seed oil polyol:

[0055] Grape seed oil and pentaerythritol were put into a three-necked flask at a molar ratio of 1.5:0.7, and tetrabutyl titanate (3% of the total weight of grape seed oil and pentaerythritol) was added. The mixture was heated to 160° C. in an oil bath under nitrogen for 5 hours, and grape seed oil polyol was obtained by suction filtration.

[0056] (2) Preparation of cashew nut shell oil polyester polyol with amino group:

[0057] 100 g of cashew nut shell oil polyol and 35.12 g of aminomalonic acid were placed in a reactor, and 4 g of tetrabutyl titanate was added. Then nitrogen was introduced into the reactor, and the reactor was heated to 190° C. and stirred for 4 h.

[0058] The reactor was evacuated to a vacuum, and then heated to 230° C., and kept warm for 3 hours, and the precipitate was filtered and collected to obtain a cashew nut shell oil polyester polyol with amino groups;

[0059] (3) Preparation of modified 1,5-pentanediisocyanate:

[0060] 1,5-pentyl diisocyanate and 3-aminopropyl triethoxysilane were mixed in a molar ratio of 1:0.3, and stirred at 45° C. for 1.5 hours to obtain modified 1,5-pentyl diisocyanate;

[0061] (4) Preparation of controlled release membrane:

[0062] Grape seed oil polyol and modified bio-based 1,5-pentanediisocyanate were mixed in a mass ratio of 1.3:1, placed in an oven and preheated to 65° C., then stirred evenly and bubbles were removed to obtain a controlled release membrane material based on grape seed oil polyol.

[0063] The amino-containing cashew nut shell oil polyester polyol and the modified bio-based 1,5-pentanediisocyanate were mixed in a mass ratio of 1:0.8, placed in an oven and preheated to 75° C., then stirred evenly to remove bubbles, and a controlled release membrane material based on the amino-containing cashew nut shell oil polyester polyol was obtained.

[0064] The adhesive used in the present invention is prepared by the following method:

[0065] Preparation of modified urea formaldehyde adhesive (Mn = 8000-12000):

[0066] (1) Dissolve 5 g of potassium hydroxide and then dilute to volume in a 100 ml volumetric flask; dilute 0.1 ml of phosphoric acid solution in a 100 ml volumetric flask and set aside;

[0067] (2) Pour 81 g of formaldehyde aqueous solution (volume fraction 37%) into a clean beaker, and then adjust the pH to 8±0.1 with 0.05 g / ml potassium hydroxide solution to obtain a formaldehyde mixed solution;

[0068] (3) Then, 96 g of urea was added to the formaldehyde mixed solution prepared in step (2), and the mixture was reacted in a water bath at 50° C. for 35 min. Then, a 0.1% by volume phosphoric acid solution was added thereto until the pH value reached 4.5±0.1. Then, 1.7 g of corn starch was added thereto, and the mixture was reacted at 50° C. for 20 min. Then, the pH value was adjusted to 8±0.1 with a 0.05 g / ml potassium hydroxide solution, and the mixture was reacted at 50° C. for 10 min to obtain a modified urea-formaldehyde adhesive. The molecular weight of the obtained modified urea-formaldehyde adhesive was 8000-12000.

[0069] Preparation of modified ammonium polyphosphate binder:

[0070] (1) Ammonium polyphosphate and polyethylene glycol were mixed in a mass ratio of 10:12.5 and placed in a three-necked flask, and tetrabutyl titanate (3% by weight of the total weight of ammonium polyphosphate and polyethylene glycol) was added, and the mixture was heated to 140° C. in an oil bath under nitrogen conditions for 4 hours, and then filtered to obtain an esterified ammonium polyphosphate adhesive.

[0071] Preparation of cyclodextrin adhesive:

[0072] (1) 100 g of cyclodextrin, 5 g of propylene glycol, 2 g of polyethyl acrylate, 2 g of sodium dodecylbenzenesulfonate, and 5 g of ethylene glycol dimethacrylate were mixed and placed in a three-necked flask, and then 150 ml of water was added. The mixture was stirred in a water bath at 40-60° C. for 1.5 h to obtain a cyclodextrin adhesive.

[0073] Embodiment 1: Preparation of tobacco-specific fertilizer with multi-layer composite coating and full nutrients:

[0074] (1) Turn on the disc granulator, put 2 kg of potassium sulfate granules into the disc, spray the potassium sulfate in the disc granulator with a modified urea formaldehyde binder (Mn=8000-12000) using a spray pot, then add ammonium sulfate powder to evenly coat the surface of the fertilizer particles, and repeat the operation until the total amount of modified urea formaldehyde binder added is 20 g and the total amount of ammonium sulfate added is 800 g; take out all the fertilizer in the disc and sieve it to obtain potassium sulfate fertilizer wrapped with ammonium sulfate with the binder;

[0075] (2) placing the ammonium sulfate-potassium sulfate fertilizer coated with an adhesive into a rotating drum, coating the controlled-release film material based on grape seed oil polyol with 1% of the mass of the ammonium sulfate-potassium sulfate fertilizer coated with the adhesive each time, repeating the above operation until the weight of the coated controlled-release film material accounts for 4% of the mass of the ammonium sulfate-potassium sulfate fertilizer coated with the adhesive (i.e., the coating thickness is 4%), and after stabilization, a composite coated controlled-release fertilizer is obtained;

[0076] (3) Put the composite coated controlled-release fertilizer into a disc granulator, add modified urea formaldehyde binder and compound fertilizer to the composite coated controlled-release fertilizer in batches, the amount of binder added accounts for 3% of the mass of the compound fertilizer, until 170g of compound fertilizer is added, so that the surface of the composite coated controlled-release fertilizer is evenly coated with the compound fertilizer, and a multi-layer composite coated full-nutrient tobacco-specific fertilizer is obtained, and the particle diameter is 7-13mm.

[0077] Figure 2 The schematic diagram of the plan and cross section of the tobacco-specific fertilizer with multi-layer composite coating and complete nutrients prepared in Example 1.

[0078] Embodiment 2: Preparation of tobacco-specific fertilizer with multi-layer composite coating and full nutrients:

[0079] (1) turning on the disc granulator, placing 2 kg of potassium sulfate granules into the disc, spraying the modified ammonium polyphosphate binder onto the potassium sulfate in the disc granulator with a spray bottle, and then adding ammonium sulfate powder to evenly coat the surface of the fertilizer granules, repeating the operation until the total amount of the modified ammonium polyphosphate binder added is 20 g and the total amount of ammonium sulfate added is 800 g; taking out all the fertilizer in the disc and sieving it to obtain potassium sulfate fertilizer coated with ammonium sulfate with the binder;

[0080] (2) placing the ammonium sulfate-potassium sulfate fertilizer coated with an adhesive into a rotating drum, coating the controlled-release film material based on cashew nut shell liquid polyester polyol with an amino group with 1% of the mass of the ammonium sulfate-potassium sulfate fertilizer coated with the adhesive each time, repeating the above operation until the weight of the coated controlled-release film material accounts for 5% of the mass of the ammonium sulfate-potassium sulfate fertilizer coated with the adhesive (i.e., the coating thickness is 5%), and after stabilization, a composite coated controlled-release fertilizer is obtained;

[0081] (3) Put the composite coated controlled-release fertilizer into a disc granulator, add modified ammonium polyphosphate binder and compound fertilizer to the composite coated controlled-release fertilizer in batches, the amount of binder added accounts for 3% of the mass of the compound fertilizer, until 170g of compound fertilizer is added, so that the surface of the composite coated controlled-release fertilizer is evenly coated with the compound fertilizer, and a multi-layer composite coated tobacco-specific fertilizer with full nutrients is obtained, and the particle diameter is 7-13mm.

[0082] Example 3: Preparation of tobacco-specific fertilizer with multi-layer composite coating and full nutrients:

[0083] (1) Turn on the disc granulator, put 2 kg of potassium sulfate granules into the disc, spray cyclodextrin binder on the potassium sulfate in the disc granulator with a spray bottle, and then add ammonium sulfate powder to evenly coat the surface of the fertilizer granules. Repeat the operation until the total amount of cyclodextrin binder added is 30 g and the total amount of ammonium sulfate added is 800 g; take out all the fertilizer in the disc and sieve it to obtain potassium sulfate fertilizer wrapped with ammonium sulfate with binder;

[0084] (2) placing the ammonium sulfate-potassium sulfate fertilizer coated with an adhesive into a rotating drum, coating the controlled-release film material based on grape seed oil polyol with 1% of the mass of the ammonium sulfate-potassium sulfate fertilizer coated with the adhesive each time, repeating the above operation until the weight of the coated controlled-release film material accounts for 6% of the mass of the ammonium sulfate-potassium sulfate fertilizer coated with the adhesive (i.e., the coating thickness is 6%), and after stabilization, a composite coated controlled-release fertilizer is obtained;

[0085] (3) Put the composite coated controlled-release fertilizer into a disc granulator, add cyclodextrin adhesive and compound fertilizer to the composite coated controlled-release fertilizer in batches, the amount of adhesive added accounts for 4.5% of the mass of the compound fertilizer, until 260g of compound fertilizer is added, so that the surface of the composite coated controlled-release fertilizer is evenly coated with the compound fertilizer, and a multi-layer composite coated tobacco-specific fertilizer with full nutrients is obtained, and the particle diameter is 7-13mm.

[0086] Test Example 1: Investigation of the performance of the coated controlled-release fertilizer prepared using the coating material of the present invention

[0087] 1. Nutrient release determination:

[0088] The nitrogen and potassium release rates of the coated controlled-release fertilizers prepared in Examples 1-3 were determined according to the National Standard for Slow-Release Fertilizers GB / T23348-2009 of the People's Republic of China.

[0089] The results are as follows Figure 3 and Figure 4 As shown in the figure, 4% is the release curve of the tobacco fertilizer with full nutrients of the multi-layer composite coating prepared in Example 1, 5% is the release curve of the tobacco fertilizer with full nutrients of the multi-layer composite coating prepared in Example 1, and 6% is the release curve of the tobacco fertilizer with full nutrients of the multi-layer composite coating prepared in Example 3. It can be seen from the figure that the tobacco fertilizer with full nutrients of the multi-layer composite coating prepared in Example 2 with a coating thickness of 5% is more suitable for the growth of tobacco.

[0090] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A tobacco-specific fertilizer with multi-layer composite coating and full nutrients, characterized in that: From the inside to the outside, they are potassium sulfate, ammonium sulfate, controlled-release membrane material and compound fertilizer, and the ammonium sulfate and potassium sulfate, and the controlled-release membrane material and compound fertilizer are all bonded by a binder; The mass ratio of potassium sulfate, ammonium sulfate and compound fertilizer is (150-250): (60-100): (15-30); The adhesive is one or more of a modified urea formaldehyde adhesive, a modified ammonium polyphosphate adhesive, and a cyclodextrin adhesive; The controlled release membrane material is obtained by reacting a first component and a second component, wherein the first component is one or more of grape seed oil polyol and cashew nut shell oil polyester polyol with amino group; The second component is one or more of modified 1,5-pentamethylene diisocyanate, (R)-2-heptamethylene diisocyanate and L-lysine diisocyanate.

2. The tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to claim 1 is characterized in that: The compound fertilizer is nitrate nitrogen fertilizer.

3. The tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to claim 1 is characterized in that: The controlled release membrane is prepared by the following method: The first component and the second component are mixed in a mass ratio of (0.8-1.5):(1-1.3), heated to 60-70° C., and then stirred evenly to remove bubbles to obtain a controlled release membrane material.

4. The tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to claim 1 is characterized in that: The grape seed oil polyol is prepared by the following method: Grape seed oil and pentaerythritol are mixed in a molar ratio of (1-2): (0.4-1) as a reaction substrate, 0.5%-5% of tetrabutyl titanate by weight of the total reaction substrate is added, and the mixture is reacted at 160-190° C. for 4-6 hours under nitrogen conditions. After the reaction, the precipitate is collected by filtration to obtain grape seed oil polyol.

5. The tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to claim 1 is characterized in that: The amino-containing cashew nut shell oil polyester polyol is prepared by the following method: Mix cashew nut shell oil polyol and dicarboxylic acid with amino group in a mass ratio of (100-120): (35-60) as a reaction substrate, add 0.5%-5% of tetrabutyl titanate based on the total mass of the reaction substrate, react for 4-5 hours at 190° C.-200° C. under nitrogen conditions, then react for 3-4 hours at 220-230° C. under vacuum conditions, and collect the precipitate by filtration after the reaction to obtain cashew nut shell oil polyester polyol with amino group; The dicarboxylic acid with an amino group is one or more of aminomalonic acid, 3-aminoglutaric acid and DL-2-aminosuberic acid.

6. The tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to claim 1 is characterized in that: The modified 1,5-pentyl diisocyanate is prepared by the following method: 1,5-pentyl diisocyanate and 3-aminopropyl triethoxysilane are mixed in a molar ratio of (1-1.1):(0.2-0.4), and stirred at 40-50° C. for reaction for 1-2 hours to obtain modified 1,5-pentyl diisocyanate.

7. The tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to claim 1 is characterized in that: The modified urea-formaldehyde adhesive is prepared by the following method: The pH of a 30-40% formaldehyde aqueous solution is adjusted to 7.5-8.5 with a potassium hydroxide aqueous solution to obtain a formaldehyde mixed solution; Add urea to the formaldehyde mixed solution, the mass of urea is 1-2 times the mass of the formaldehyde aqueous solution, react at 40-60° C. for 30-40 minutes, add a phosphoric acid aqueous solution with a volume fraction of 0.05-0.15% to adjust the pH to 4-5, then add corn starch with a mass fraction of 1%-5% of the formaldehyde aqueous solution, continue to react at 40-60° C. for 15-25 minutes, and then adjust the pH to 7.5-8.5 with a potassium hydroxide aqueous solution, continue to react at 40-60° C. for 5-15 minutes to obtain a modified urea-formaldehyde adhesive, wherein the molecular weight of the obtained modified urea-formaldehyde adhesive is 8000-12000; The concentration of the potassium hydroxide aqueous solution is 0.01-0.1 g / ml.

8. The tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to claim 1 is characterized in that: The modified ammonium polyphosphate binder is prepared by the following method: Ammonium polyphosphate and polyethylene glycol are mixed in a mass ratio of 1:(1.2-1.3) as a reaction substrate, 0.5%-5% of tetrabutyl titanate based on the total mass of the reaction substrate is added, and the mixture is reacted at 130-170° C. for 4-6 hours under nitrogen conditions. After the reaction, the mixture is filtered and the precipitate is collected to obtain a modified ammonium polyphosphate adhesive.

9. The tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to claim 1, characterized in that: The cyclodextrin adhesive is prepared by the following method: Cyclodextrin, glycerol, polyethyl acrylate, sodium dodecylbenzene sulfonate and ethylene glycol dimethacrylate are uniformly mixed in a mass ratio of (1-1.1):(0.05-0.15):(0.1-0.3):(0.01-0.05):(0.02-0.1), and then water 1-2 times the mass of cyclodextrin is added, and the mixture is reacted at 40-60°C for 1-2h to obtain a cyclodextrin adhesive.

10. The method for preparing the tobacco-specific fertilizer with multi-layer composite coating and full nutrients according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) adding potassium sulfate to a granulator, and then sequentially adding a binder and ammonium sulfate to the potassium sulfate, wherein the amount of the binder added is 1-5% of the mass of the ammonium sulfate, to obtain a potassium sulfate fertilizer in which ammonium sulfate is wrapped with the binder; (2) placing the ammonium sulfate-coated potassium sulfate fertilizer in a drum, adding a controlled-release film material for coating, so that the weight of the controlled-release film material accounts for 0.5-8% of the weight of the ammonium sulfate-coated potassium sulfate fertilizer, to obtain a composite coated controlled-release fertilizer; (3) Put the composite coated controlled-release fertilizer into a granulator, add a binder and a composite fertilizer to the composite coated controlled-release fertilizer in sequence, wherein the amount of the binder added accounts for 1%-5% of the mass of the composite fertilizer, and obtain a multi-layer composite coated tobacco-specific fertilizer with full nutrients, and the particle diameter is 7-13 mm.

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