A fertilizer slow-release organic silicon composite material flowerpot and preparation method thereof

Abstract

The invention discloses a fertilizer slow-release organic silicon composite material flowerpot and a preparation method thereof. The components containing poly(lactide-dimethylsiloxane), isocyanate, hydroxy silicone oil or alkoxy silicone oil and chemical fertilizer are mixed to prepare the organic silicon flowerpot. The wall of the flowerpot is loaded with fertilizer suitable for the growth of flowers and plants. The fertilizer is slowly released into the soil in the flowerpot over a long period of time, thereby eliminating the process of fertilizing when planting flowers and plants. The slow-release flowerpot of the invention has good controlled-release performance, is cheap in raw material source, and has high utilization rate of nutrient elements.

Description

Technical Field

[0001] The invention belongs to the field of organic silicon flower pots, and in particular relates to a fertilizer slow-release organic silicon composite material flower pot and a preparation method thereof. Background Art

[0002] At the end of the isocyanate synthesis process, the light component is usually separated from the product mixture by distillation. The high-boiling solid residue or distillation residue discharged from the bottom fraction of the distillation tower after drying is commonly known as tar powder. Tar powder is a mixture of polymerized biuret byproducts and various impurities. Among them, MDI tar, also known as polymerized MDI, can be widely used in soft foam, hard foam, adhesives, etc. However, ADI tar and TDI tar have basically no use value due to their weak reaction activity, soft molecular structure, low boiling point, strong volatility, high toxicity, high viscosity, and many polyurea agglomerates. What's more serious is that as hazardous waste, it is difficult to be treated due to its characteristics of high pollution and high harmful gases during incineration. If it cannot be treated for a long time, it will greatly limit the production capacity of ADI and TDI.

[0003] Silicone products are widely used in various industries such as electronics, automobile manufacturing, aerospace, and medical. However, a large number of by-products or waste silicone products after use will inevitably be generated during the production and use process. From the perspective of effective resource utilization and environmental protection, these waste products need to be recycled through effective methods. Among the current methods for recycling waste silicone products, the acid-base cracking method is the most common, that is, the waste silicone products are cracked by vacuum distillation at about 150-160°C using an acid-base catalyst such as tetramethylammonium hydroxide silicon alkoxide. After dehydration and catalyst removal, the obtained dimethylsiloxane ring mixture (DMC) is then heated and ring-opening polymerized to produce new polysiloxane products such as silicone oil and silicone rubber. However, in these processes, the recovery rate is not high due to the equilibrium limitation of the cracking reaction itself, and the waste liquid after the reaction is prone to secondary pollution due to the presence of acid and alkali. In addition, the product quality purity obtained by direct synthesis using the product DMC is poor. At present, some manufacturers on the market apply cracked recovered silicone oil to silicone building adhesives, resulting in the characteristics of silicone building adhesives such as weak adhesion, poor weather resistance, rapid decay, and high oil seepage.

[0004] As people's living standards continue to improve, more and more people begin to use flowers to beautify their living space. At the same time, flowers are also widely used to beautify the urban environment. During the flower cultivation process, fertilizers need to be released frequently, otherwise it is difficult to maintain good growth. However, chemical fertilizers are quickly dissolved in water, released in a concentrated manner, and have low utilization rates. Fertilizers need to be applied multiple times in different growth cycles of flowers, which is very inconvenient to manage. Especially during major festivals or major events, millions of pots of flowers are often needed, which increases the difficulty of management.

[0005] As an effective means to solve the low utilization rate of chemical fertilizers, coated slow-release fertilizers have been commercialized. However, coated fertilizers on the market still have many defects. Inorganic coated fertilizers have poor elasticity and are prone to pinholes and cracks. The existing organic coated fertilizers in China have poor wear resistance, poor degradability, and are easily dissolved by water.

[0006] Patent CN109279864A discloses a ceramic flowerpot capable of slow-release fertilizer, which comprises an outer barrier layer, an inner space layer, and cross-linked fertilizer particles filled in the inner space layer. However, this flowerpot increases the thickness of the flowerpot itself, and the production cost is high, which makes it very inconvenient to use. A silicone-polyurethane composite flowerpot for slow-release fertilizer is made by coating compound fertilizer in a silicone-polyurethane composite material with a slow-release function. The compound fertilizer is absorbed by flowers and plants through full contact with a conveying and circulating medium such as water and gas. The process for preparing the silicone-polyurethane composite flowerpot of the present invention is simple and easy to operate, and the obtained flowerpot has a low production cost, and realizes the reuse of isocyanate tar and silicone rubber cracking silicone oil. Summary of the invention

[0007] In view of the above-mentioned problems existing in the prior art, the present application provides a fertilizer slow-release organosilicon composite material flowerpot and a preparation method thereof. The wall of the flowerpot is loaded with fertilizer suitable for the growth of flowers and plants. The fertilizer is slowly released into the soil in the flowerpot over a long period of time, eliminating the process of fertilizing when planting flowers and plants. The slow-release flowerpot of the present invention has good controlled-release performance, cheap raw material source, and high utilization rate of nutrient elements.

[0008] To solve the above problems, the present invention provides the following technical solutions:

[0009] A fertilizer slow-release organic silicon composite material flower pot, the raw materials for preparing the same include the following components in parts by weight:

[0010] Component A:

[0011] Hydroxyl silicone oil or alkoxy silicone oil 10-40 parts, preferably 15-35 parts

[0012] Poly(lactide-dimethylsiloxane) 5-10 parts, preferably 6-9 parts

[0013] Filler 50-65 parts, preferably 52-63 parts

[0014] 0.5 to 5 parts of water, preferably 0.5 to 4.5 parts;

[0015] Component B:

[0016] 10 to 40 parts of silane-modified isocyanate prepolymer, preferably 20 to 30 parts,

[0017] Poly(lactide-dimethylsiloxane) 5 to 45 parts, preferably 10 to 40 parts,

[0018] 0.1 to 10 parts of catalyst, preferably 1 to 8 parts,

[0019] 1 to 30 parts of crosslinking agent, preferably 5 to 25 parts

[0020] 10 to 60 parts of filler, preferably 20 to 50 parts;

[0021] Component C:

[0022] 20 to 65 parts of clay, preferably 35 to 50 parts,

[0023] 1-25 parts, preferably 5-20 parts, of humus-rich sludge;

[0024] 10 to 40 parts of wood chips, preferably 20 to 30 parts,

[0025] 15 to 42 parts of chemical fertilizer, preferably 18 to 37 parts,

[0026] 5 to 9 parts of water, preferably 6 to 8 parts;

[0027] The mass ratio of component A, component B and component C is 90-100:75-90:100-200.

[0028] Preferably, the poly(lactide-dimethylsiloxane) is a regular copolymer of dimethylcyclosiloxane and lactide.

[0029] Preferably, the preparation method of the poly(lactide-dimethylsiloxane) is as follows: dimethylcyclosiloxane, lactide, a chain stopper, and a catalyst are added to a reaction kettle together, and a polymerization reaction is carried out at a certain temperature and pressure. The reaction is carried out under inert gas conditions, and after the reaction is completed, the catalyst is decomposed and removed by high-temperature heating to obtain a random copolymer of poly(lactide-dimethylsiloxane).

[0030] Preferably, the reaction temperature is 85°C to 120°C, the pressure is 0.01 to 0.1 MPa, and the reaction time is 4 to 6 hours.

[0031] Preferably, the dimethylcyclosiloxane has the general formula (Me2SiO) n , (n=3-8), a dimethylcyclosiloxane mixture obtained by cracking waste silicone rubber can also be used. The dimethylcyclosiloxane mixture obtained by cracking waste silicone rubber is mainly (Me2SiO n (n=3-8). The molar ratio of lactide to dimethylsiloxane is preferably 1:1-2:1. The ester bond is very active and easily decomposed. Lactide is a monomer of polylactic acid and a degradable material, which generates lactic acid after being degraded. Poly(lactide-dimethylsiloxane) can be degraded in nature, making the flower pot more easily degradable.

[0032] Preferably, the chain stopper is hexamethyldisiloxane (MM), octamethyltrisiloxane (MDM), decamethyltetrasiloxane (MD2M), and the molar ratio of the chain stopper to dimethylcyclosiloxane is preferably 1:10 to 1:50.

[0033] Preferably, the catalyst is an alkaline catalyst, preferably one or more of sodium ethoxide, potassium ethoxide, butyl lithium, tetramethylammonium hydroxide siliconate, potassium hydroxide, lithium hydroxide, and tetrabutyl phosphonium hydroxide siliconate, among which tetramethylammonium hydroxide siliconate and tetrabutyl phosphonium hydroxide siliconate are preferred.

[0034] Preferably, the amount of the alkaline catalyst added is 0.01% to 0.03% of the total mass of the cyclosiloxane, lactide and chain stopper.

[0035] Preferably, the preparation method of the silane-modified isocyanate prepolymer is: under nitrogen protection and at an appropriate temperature, isocyanate is added, and a silane coupling agent corresponding to 1 to 1.5 times the NCO molar content is added, and after the addition reaction is completed under the action of an amine catalyst, the temperature is then lowered to room temperature and the material is discharged to obtain a silane-modified prepolymer.

[0036] Preferably, the reactant temperature is 60-80° C. and the nitrogen pressure is 0.01-0.1 MPa.

[0037] Preferably, the isocyanate is a mixture of one or more of ADI tar or TDI tar. The ADI tar includes HDI tar, HMDI tar or IPDI tar.

[0038] Modifying isocyanate tar with a silane coupling agent that can react with NCO can not only greatly reduce its toxicity, but also greatly reduce its viscosity. The presence of some insoluble, granular polyureas is another obstacle to its application. When used in flower pots, the insoluble, granular polyureas are used as fillers similar to powders, avoiding complex operations such as separation like other applications. The ADI tars include HDI tar, HMDI tar, IPDI tar

[0039] The amine catalysts described above are one or more of triethylenediamine (TEDA), N-methylimidazole, 1,2-dimethylimidazole, N-methylmorpholine, N-ethylmorpholine, triethylamine, N,N'-dimethylpiperazine, N-methyl dicyclohexylamine, pentamethyldipropylenetriamine, N-methyl-N'-(2-dimethylamino)-ethyl-piperazine, tributylamine, pentamethyldiethylenetriamine (PMDETA), N,N-dimethylcyclohexylamine, hexamethyltriethylenetetramine, heptamethyltetraethylenepentamine, pentamethyldipropylenetriamine, triethanolamine, dimethylethanolamine, bis(dimethylaminoethyl) ether, tris(3-dimethylamino)-propylamine, 1,8-diazabicyclo[5.4.0]undecene.

[0040] Preferably, the dosage of the amine catalyst is 0.05-0.15% of the total weight of the isocyanate and the silane coupling agent.

[0041] The silane coupling agent is one or more of epoxy group silane coupling agents, amino group silane coupling agents, and mercapto group silane coupling agents. Among them, preferably 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane (KH560), 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-aminoethyl-3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, etc.

[0042] Preferably, the dosage of the silane coupling agent is 1.05-1.25 times the molar amount of isocyanate groups in the reaction system.

[0043] The hydroxy silicone oil is preferably one or more of dimethyl hydroxy silicone oil, and the structural formula is HO[(CH3)2SiO] n H, 3 < n < 700 is a linear polymer with a main chain mainly composed of repeating siloxane bonds, methyl groups as side chains and hydroxy groups as end groups. The viscosity is 20 cp to 20000 cp.

[0044] Preferably, the alkoxy silicone oil refers to the silicone oil obtained by the end-capping reaction of dimethyl hydroxy silicone oil with alkoxysilane. The structural formula is (CH3O)3SiO[(CH3)2SiO] mSi(OCH3)3, where 3 < m < 700, is a linear polymer with a main chain mainly composed of repeating silicon-oxygen bonds, methyl groups as side chains, and alkoxy groups as end-caps.

[0045] The filler is selected from one or more of mica powder, talc powder, diatomaceous earth, and calcium carbonate, among which diatomaceous earth and calcium carbonate are preferred.

[0046] Preferably, in the B component, the catalyst is one of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, bis(dodecylthio)dibutyltin, and mercaptodioctyltin catalyst, preferably dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate;

[0047] The cross-linking agent in the B component is one or more of tetraethyl orthosilicate, oligomers of tetraethyl orthosilicate, tetrapropyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, propyltriacetoxysilane, di-tert-butoxydiacetoxysilane, methyltributanone oxime silane, phenyltributanone oxime silane, tetrabutanone oxime silane, methyltriacetone oxime silane, dimethyldi(N-methylacetamido)silane, dimethyldi(N-ethylacetamido)silane, methylphenyldi(N-methylacetamido)silane, diphenyldi(N-methylacetamido)silane, etc., among which tetraethyl orthosilicate, tetrapropyl orthosilicate, and methyltrimethoxysilane are preferred;

[0048] Preferably, in the B component, the filler is selected from one or more of mica powder, talc powder, diatomaceous earth, and calcium carbonate, among which diatomaceous earth and calcium carbonate are preferred.

[0049] Preferably, the compound fertilizer can be configured according to different nutritional requirements of flowers. Optional fertilizer components include potassium nitrate, urea, potassium chloride, ammonium phosphate, potassium sulfate, ammonium sulfate, boric acid, calcium nitrate, manganese sulfate, superphosphate, zinc sulfate, magnesium sulfate, copper sulfate, iron sulfate, ammonium molybdate, etc. Among them, two or more of potassium nitrate, calcium nitrate, superphosphate, magnesium borate, copper sulfate, and iron sulfate are preferred.

[0050] The present invention also provides a method for preparing the flowerpot. The raw materials in the A component are mixed to obtain the A component, the raw materials in the B component are mixed to obtain the B component, the raw materials in the C component are mixed and stirred to form a slurry, then the slurry is prepared into fertilizer particles, dried and cured as the C component. The A component, B component, and C component are mixed and then poured into a flowerpot mold, and heated and cured at 50 - 80 °C, and then demolded to obtain the flowerpot.

[0051] Preferably, the fertilizer particles have a particle size of 1 - 5 mm, preferably 2 - 4 mm fertilizer particles.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. This application can reuse the tar in the isocyanate production process as raw material, and use silane coupling agent to modify ADI tar and TDI tar, which can be detoxified and reduced in viscosity, so that it has low toxicity and high reactivity.

[0054] 2. Make compound fertilizer into granules, and use the processing characteristics of organic silicone rubber to use compound fertilizer granules as powder components to make flower pots that can be poured and solidified, and can release nutrients. The flower pots and seedlings can be buried in the soil without removal. The flower pots will also give the seedlings corresponding organic fertilizers while degrading, and no further fertilization is required; if the flower pots are used for ornamental plants, the convenience is that the fertilizer is slowly released into the soil in the flower pots over a long period of time, eliminating the process of fertilizing when planting flowers and plants.

[0055] 3. With the help of organic silicone rubber processing technology, the compound fertilizer is wrapped in the flower pot to make it into a whole, so that the flower pot has a slow-release function. Different from the traditional compound fertilizer technology and flower pot sintering technology, the production process is simple.

[0056] 4. Reuse silicone rubber to crack and recover silicone oil. The silicone oil recovered by cracking silicone rubber has the characteristics of fast decay and easy decomposition, making the flower pots have the characteristics of slow-release fertilizer and biodegradability.

[0057] 5. Dimethylsiloxane and lactide are subjected to anionic ring-opening copolymerization to obtain a random copolymer of poly(lactide-dimethylsiloxane). Lactide is a monomer of polylactic acid and a degradable material. It generates lactic acid after being degraded. Lactide and dimethylsiloxane are connected by ester bonds and are also easily decomposed. This makes the flower pots more easily degradable.

[0058] 6. The present invention can be prepared using waste resources, the economic cost of raw materials is low, it has strong economic and social benefits, greatly reduces environmental pressure, turns waste into treasure, reduces production costs, and improves resource utilization.

[0059] 7. Due to its low surface tension, organosilicon can quickly wet and penetrate, and its oligomers can effectively combine with nutrients under certain conditions, making it an excellent choice for preparing slow-release fertilizers. In addition to its remarkable slow-release effect, organosilicon also has the following functional characteristics when used in slow-release fertilizers: First, after fertilization, the silicified cells produced can effectively regulate the opening and closing of leaf stomata, thereby improving crop stress resistance; second, it can enhance crop resistance to pests and diseases and reduce pest damage; third, silicon can improve soil, correct soil acidity, increase soil base, promote the decomposition of fertilizers, inhibit soil pathogens, soil aggregate structure and the relationship between plant root growth and development; fourth, silicon can silicify crop epidermal cells and promote photosynthesis; fifth, it can enhance the aeration of crops and promote root development; sixth, it can reduce the fixation of phosphorus in the soil and promote nutrient absorption; seventh, it can control fertilization, reduce the application of nitrogen and phosphorus, and reduce the antagonism of trace elements, which has a significant effect on improving crop quality. DETAILED DESCRIPTION

[0060] The present invention is further described below in conjunction with the examples. The sources of some of the main raw materials are shown in Table 1.

[0061] Raw material name Manufacturer Pentamethyldiethylenetriamine (PMDETA) Wanhua Chemical Group Co., Ltd. N,N-Dimethylcyclohexylamine (DMCHA) Wanhua Chemical Group Co., Ltd. Octamethylcyclotetrasiloxane Shandong Jinling Group Co., Ltd. Dodecamethylcyclohexasiloxane Shenzhen Jipeng Silicon Fluoride Materials Co., Ltd. Decamethylcyclopentasiloxane Shenzhen Jipeng Silicon Fluoride Materials Co., Ltd. <![CDATA[Decamethyltetrasiloxane (MD2M)]]> Shanghai Yuanye Biotechnology Co., Ltd. Octamethyltrisiloxane (MDM) Sysbo Silicone Co., Ltd. Hexamethyldisiloxane(MM) Jiangsu Xinsu Materials Co., Ltd. 3-Aminopropyltriethoxysilane Nanjing Nengde New Materials Co., Ltd. Tetramethylammonium hydroxide siliconate Kent Catalytic Materials Co., Ltd. Tetrabutyl Hydroxophosphonium Siliconate Kent Catalytic Materials Co., Ltd. 3-Glycidyloxypropyltriethoxysilane Nanjing Nengde New Materials Co., Ltd. HDI Tar Wanhua Chemical Group Co., Ltd. TDI tar Wanhua Chemical Group Co., Ltd. HMDI tar Wanhua Chemical Group Co., Ltd. Lactide Shanghai Yuanye Biotechnology Co., Ltd. 3-Mercaptopropyltriethoxysilane Nanjing Nengde New Materials Co., Ltd.

[0062] Example 1

[0063] (1) Preparation of silane-modified isocyanate prepolymer

[0064] 500 g of HDI tar was added as a base, and its NCO content was 15.3%. 1 g of amine catalyst PMDETA was added, and the temperature was raised to 60°C. Under a nitrogen atmosphere of 0.01 MPa, 557.83 g of 3-glycidyloxypropyltriethoxysilane was added, and the molar ratio of NCO to 3-glycidyloxypropyltriethoxysilane was 1:1.1. After the reaction was completed, the temperature was lowered to room temperature and the material was discharged to obtain 1020 g of epoxy silane-modified HDI tar prepolymer;

[0065] (2) Preparation of poly(lactide-dimethylsiloxane)

[0066] In a 5L reactor, add 1500g octamethylcyclotetrasiloxane (D4), 971g lactide, 120g decamethyltetrasiloxane (MD2M) and 13g of 2wt% tetramethylammonium hydroxide silicon alkoxide, and dehydrate for 1h under N2, 50℃ and reduced pressure (0.1MPa). Then slowly heat the reaction mixture to 85-90℃, pass N2 and gradually increase the vacuum degree to make the residual pressure reach 0.08MPa, and react for 4h. Release the vacuum, raise the temperature to 150℃ under normal pressure and maintain for 1h to decompose the catalyst. Then gradually evacuate to a residual pressure of about 0.1MPa or less, and slowly increase the material temperature to 200℃, distill and remove low-boiling substances, and after cooling, obtain about 2430g colorless and transparent poly (lactide-dimethylsiloxane) silicone oil, with a yield of about 93.3% and a viscosity (25℃) of about 900-1000mPa﹒s.

[0067] (3) Preparation of component A

[0068] 100 g of 1500 cp 107 hydroxy silicone oil, 150 g of 5000 cp 107 hydroxy silicone oil, 90 g of the poly(lactide-dimethylsiloxane) mentioned in step (1), 530 g of diatomaceous earth, and 30 g of water are mixed uniformly in proportion at room temperature and pressure.

[0069] (4) Preparation of component B

[0070] The product of step (1), 300 g of siloxane-terminated isocyanate prepolymer, 150 g of poly(lactide-dimethylsiloxane), 10 g of dibutyltin dilaurate, 300 g of tetraethyl orthosilicate, and 230 g of diatomaceous earth, were mixed according to the proportions at room temperature and pressure.

[0071] (5) Preparation of C-component fertilizer granules

[0072] (1) Compound fertilizer is prepared according to a certain proportion, and potassium nitrate 70g, calcium nitrate 60g, superphosphate 60g, magnesium borate 20g, copper sulfate 5g, iron sulfate 20g, clay 380g, humus-rich sludge 185g, and wood chips 200g are mixed, 80g of water is added, and then mixed and stirred for 3.5 to 5.5 minutes to prepare slurry; (2) the slurry is injected into a mold to be processed into round fertilizer particles; (3) the formed fertilizer particles are dried and solidified; screening is performed in step (2), and the particle size of the fertilizer after screening is 2 to 4 mm.

[0073] (6) Preparation of polyurethane and silicone composite slow-release compound fertilizer flower pots

[0074] The above three components A, B and C were mixed in a weight ratio of 98:88:190 and poured into a flower pot mold, heated and cured at 55° C. for 30 minutes, and demolded.

[0075] According to the national standard determination method (Kjeldahl method), the results show that the initial nitrogen release rate of the slow-release fertilizer product is 2.98%, and the cumulative nitrogen release rate of 28d, 35d, and 45d is tested respectively. The results are shown in Table 2. From Table 2, it can be seen that the slow-release fertilizer flower pot meets the slow-release effect specified in GB / T23348-2009. The slow-release period is 78d.

[0076] Example 2

[0077] (1) Preparation of silane-modified prepolymer

[0078] 500 g of TDI tar was added as a base, and its NCO content was 22.5%. 1 g of amine catalyst DMCHA was added, and the temperature was raised to 70°C. Under a nitrogen atmosphere of 0.01 MPa, 770.84 g of 3-aminopropyltriethoxysilane was added, and the molar ratio of NCO to 3-aminopropyltriethoxysilane was 1:1.3. After the reaction was completed, the temperature was lowered to room temperature and the material was discharged to obtain 1250.8 g of TDI tar prepolymer modified with urea-based silane;

[0079] (2) Preparation of poly(lactide-dimethylsiloxane)

[0080] In a 5L reactor, add 1500g of decamethylcyclopentasiloxane, a product of cracked silicone rubber, 874.8g of lactide, 31.93g of octamethyltrisiloxane (MDM) and 24.06g of 2wt% tetramethylammonium hydroxide silicon alkoxide, and dehydrate for 1.5h under N2, 50℃ and reduced pressure (0.09MPa). Then slowly heat the reaction mixture to 100-105℃, pass N2 and gradually increase the vacuum degree to 0.07MPa, and react for 5h. Release the vacuum, raise the temperature to 170℃ under normal pressure and maintain for 1.5h to decompose the catalyst. Then gradually evacuate to a residual pressure of about 0.09 MPa or less, and slowly increase the material temperature to 200°C, distill and remove low-boiling substances, and after cooling, obtain about 2230 g of colorless and transparent poly(lactide-dimethylsiloxane) silicone oil, with a yield of about 91.7% and a viscosity (25°C) of about 1000-1200 mPa﹒s.

[0081] (3) Preparation of component A

[0082] 150 g of 2000 cp alkoxy-terminated dimethyl silicone oil, 150 g of 5000 cp alkoxy-terminated dimethyl silicone oil, 60 g of poly(lactide-dimethylsiloxane), 630 g of diatomaceous earth, and 5 g of water were mixed uniformly in proportion at room temperature and pressure.

[0083] (4) Preparation of component B

[0084] 200 g of the siloxane-terminated isocyanate prepolymer produced in step (1), 120 g of poly(lactide-dimethylsiloxane), 80 g of stannous octoate, 250 g of propyl orthosilicate, and 350 g of calcium carbonate were mixed in proportion at room temperature and pressure.

[0085] (5) Preparation of C-component fertilizer granules

[0086] (1) adding compound fertilizer according to proportion, mixing 70g of potassium nitrate, 60g of calcium nitrate, 60g of calcium phosphate, 20g of magnesium borate, 5g of copper sulfate, 20g of iron sulfate, 380g of clay, 185g of humus-rich sludge, and 200g of wood chips, adding 60g of water, and then mixing and stirring for 3.5 to 5.5 minutes to prepare slurry; (2) injecting the slurry into a mold to process it into round fertilizer particles; (3) drying and solidifying the formed fertilizer particles; screening is performed in step (2), and the particle size of the fertilizer after screening is 2 to 4 mm.

[0087] (6) Preparation of polyurethane and silicone composite slow-release compound fertilizer flower pots

[0088] The above three components A, B and C were mixed in a weight ratio of 92:76:105 and poured into a flower pot mold, heated and cured at 75° C. for 30 minutes, and demolded.

[0089] According to the national standard determination method (Kjeldahl method), the results show that the initial nitrogen release rate of the slow-release fertilizer product is 3.5%. The cumulative nitrogen release rates were tested at 28d, 35d and 45d respectively. The results are shown in Table 2. It can be seen from Table 2 that the slow-release fertilizer pots meet the slow-release effect specified in GB / T23348-2009, and the slow-release period is 70d.

[0090] Example 3

[0091] (1) Preparation of silane-modified prepolymer

[0092] 500 g of HMDI tar was added as a bottom, and its NCO content was 8.5%. 1.27 g of amine catalyst triethylamine was added, and the temperature was raised to 80° C. Under a nitrogen atmosphere of 0.01 MPa, 356.39 g of 3-mercaptopropyltriethoxysilane was added, and the molar ratio of NCO to 3-mercaptopropyltriethoxysilane was 1:1.49. After the reaction was completed, the temperature was lowered to room temperature and the material was discharged to obtain 831 g of HMDI tar prepolymer modified with mercaptosilane;

[0093] (2) Preparation of poly(lactide-dimethylsiloxane)

[0094] In a 5L reactor, add 1500g dodecamethylcyclohexasiloxane (D6), 922.4g lactide, 11.41g hexamethyldisiloxane (MM) and 36.51g of 2wt% tetrabutylphosphonium hydroxide silicon alkoxide, and dehydrate for 1h under N2, 50℃ and reduced pressure (0.1MPa). Then slowly heat the reaction mixture to 110-115℃, pass N2 and gradually increase the vacuum degree to make the residual pressure reach 0.08MPa, and react for 6h. Release the vacuum, raise the temperature to 180℃ under normal pressure and maintain for 1.5h to decompose the catalyst. Then gradually evacuate to a residual pressure of about 0.1 MPa or less, and slowly increase the material temperature to 200°C, distill and remove low-boiling substances, and after cooling, obtain about 1960g of colorless and transparent poly(lactide-dimethylsiloxane) silicone oil, with a yield of about 79.35% and a viscosity (25°C) of about 1200-1500mPa﹒s.

[0095] (3) Preparation of component A

[0096] 125 g of 1500 cp hydroxydimethyl silicone oil, 155 g of 5000 cp alkoxydimethyl silicone oil, 80 g of poly(lactide-dimethylsiloxane), 565 g of mica powder, and 5 g of water were mixed uniformly in proportion at room temperature and pressure.

[0097] (4) Preparation of component B

[0098] The product of step (1) 250 g of siloxane-terminated isocyanate prepolymer, 280 g of poly(lactide-dimethylsiloxane), 40 g of dibutyltin diacetate, 230 g of tetraethyl orthosilicate oligomer, and 200 g of talc were mixed in proportion at room temperature and pressure.

[0099] (5) Preparation of C-component fertilizer granules

[0100] (1) Compound fertilizer is prepared according to a certain proportion, and potassium nitrate 70g, calcium nitrate 60g, calcium phosphate 60g, magnesium borate 20g, copper sulfate 5g, iron sulfate 20g, clay 380g, humus-rich sludge 185g, and wood chips 200g are mixed, and 70g of water is added, followed by mixing and stirring for 3.5 to 5.5 minutes to prepare slurry; (2) the slurry is injected into a mold to be processed into round fertilizer particles; (3) the formed fertilizer particles are dried and solidified; and screening is performed in step (2), and the particle size of the fertilizer particles after screening is 2 to 4 mm.

[0101] (6) Preparation of polyurethane and silicone composite slow-release compound fertilizer flower pots

[0102] The above three components A, B and C were mixed at a weight ratio of 95:83:150 and poured into a flower pot mold, heated and cured at 65° C. for 30 minutes, and demoulded.

[0103] According to the national standard determination method (Kjeldahl method), the results show that the initial nitrogen release rate of the slow-release fertilizer product is 4.3%. The cumulative nitrogen release rate of 28d, 35d, and 45d is shown in Table 2. It can be seen from Table 2 that the slow-release fertilizer flower pot meets the slow-release effect specified in GB / T23348-2009. The slow-release period is 67d.

[0104] According to the recommendations of the European Committee for Standardization (CEN) slow-release fertilizer task force, slow-release fertilizers should meet the following three conditions: ① the release amount within 24 hours should not exceed 15% ② the release amount within 28 days should not exceed 75% ③ the release amount within the specified time should be at least 75%. As shown in Table 2, the dissolution of N element was tracked at different time periods in Examples 1 to 3.

[0105] Table 2

[0106] project Example 1 Example 2 Example 3 Dissolution rate of N element after 28 days (%) 46.91 62 67 Dissolution rate of N element after 35 days (%) 61 70 73 Dissolution rate of N element after 45 days (%) 77 81 84

Claims

1. A fertilizer slow-release organic silicon composite material flower pot, characterized in that: The raw materials for its preparation include the following components in parts by weight: Component A: 10 to 40 parts of hydroxy silicone oil or alkoxy silicone oil, Poly(lactide-dimethylsiloxane) 5-10 parts, 50-65 parts of filler, 0.5-5 parts of water; Component B: 10-40 parts of silane-modified isocyanate prepolymer, Poly(lactide-dimethylsiloxane) 5-45 parts, 0.1 to 10 parts of catalyst, 1 to 30 parts of crosslinking agent, 10 to 60 parts of filler; Component C: 20-65 parts of clay, 1 to 25 parts of humus-rich sludge, 10-40 parts of wood chips, 15-42 parts of chemical fertilizer, 5-9 parts water; The mass ratio of component A, component B and component C is 90-100:75-90:100-200; The poly(lactide-dimethylsiloxane) is a random copolymer of dimethylcyclosiloxane and lactide; In the B component, the catalyst is one of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dibutyltin didodecylsulfide, and dioctyltin mercaptan catalysts; The crosslinking agent in the B component is one or more of tetraethyl orthosilicate, oligomers of tetraethyl orthosilicate, propyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, propyltriacetoxysilane, di-tert-butoxydiacetoxysilane, methyltributylacetoximosilane, phenyltributylacetoximosilane, tetrabutylketoneximosilane, methyltriacetoneximosilane, dimethylbis(N-methylacetylamino)silane, dimethylbis(N-ethylacetylamino)silane, methylphenylbis(N-methylacetylamino)silane, and diphenylbis(N-methylacetylamino)silane; The preparation method of the silane-modified isocyanate prepolymer is as follows: under nitrogen protection and at an appropriate temperature, isocyanate is added, and a silane coupling agent corresponding to 1.05 to 1.5 times the NCO molar content is added, and after the addition reaction is completed under the action of an amine catalyst, the temperature is lowered to room temperature and the material is discharged to obtain the silane-modified prepolymer; The silane coupling agent is one or more of an epoxy silane coupling agent, an amino silane coupling agent, and a mercapto silane coupling agent.

2. The composite material flower pot according to claim 1, characterized in that: The raw materials for its preparation include the following components in parts by weight: Component A: 15 to 35 parts of hydroxy silicone oil or alkoxy silicone oil, Poly(lactide-dimethylsiloxane) 6-9 parts, 52-63 parts of filler, 0.5-4.5 parts of water; Component B: 20-30 parts of silane-modified isocyanate prepolymer, 10 to 40 parts of poly(lactide-dimethylsiloxane), 1 to 8 parts of catalyst, 5 to 25 parts of cross-linking agent, 20 to 50 parts of filler; Component C: 35-50 parts of clay, 5-20 parts of humus-rich sludge, 20-30 parts of wood chips, 18-37 parts of chemical fertilizers, 6-8 parts water; The mass ratio of component A, component B and component C is 90-100:75-90:100-200.

3. The composite material flower pot according to claim 1, characterized in that: The preparation method of the poly(lactide-dimethylsiloxane) is as follows: dimethylcyclosiloxane, lactide, a chain stopper and a basic catalyst are added into a reaction kettle together, and a polymerization reaction is carried out under a certain temperature and pressure.

4. The composite material flower pot according to claim 3, characterized in that: The reaction is carried out under inert gas conditions. After the reaction is completed, the catalyst is decomposed and removed by high-temperature heating to obtain a random copolymer of poly(lactide-dimethylsiloxane).

5. The composite material flower pot according to claim 3, characterized in that: The reaction temperature is 85°C to 120°C, the pressure is 0.01 to 0.1 MPa, and the reaction time is 4 to 6 hours.

6. The flowerpot according to claim 3, characterized in that: The dimethylcyclosiloxane has the general formula (Me2SiO) n , n=3-8, and the molar ratio of lactide to dimethylcyclosiloxane is 1:1-2:

1.

7. The flower pot according to claim 3, characterized in that: The chain stopper is hexamethyldisiloxane, octamethyltrisiloxane and decamethyltetrasiloxane, and the molar ratio of the chain stopper to the dimethylcyclosiloxane is 1:10 to 1:

50.

8. The flowerpot according to claim 3, characterized in that: The alkaline catalyst is selected from one or more of sodium ethoxide, potassium ethoxide, butyl lithium, tetramethylammonium hydroxide siliconate, potassium hydroxide, lithium hydroxide, and tetrabutylphosphonium hydroxide siliconate.

9. The flower pot according to claim 8, characterized in that: The alkaline catalyst is selected from tetramethylammonium hydroxide siliconate and tetrabutylphosphonium hydroxide siliconate.

10. The flower pot according to claim 3, characterized in that: The addition amount of the alkaline catalyst is 0.01% to 0.03% of the total mass of the cyclosiloxane, lactide and chain stopper.

11. The flower pot according to claim 1, characterized in that: In the preparation method of the silane-modified isocyanate prepolymer, the reactant temperature is 60-80° C. and the nitrogen pressure is 0.01-0.1 MPa.

12. The flower pot according to claim 1, characterized in that: In the preparation method of the silane-modified isocyanate prepolymer, the isocyanate is selected from a mixture of one or more of ADI tar or TDI tar, and the ADI tar includes HDI tar, HMDI tar or IPDI tar.

13. The flower pot according to claim 1, characterized in that: In the preparation method of the silane-modified isocyanate prepolymer, the amine catalyst is one or more of triethylenediamine, N-methylimidazole, 1,2-dimethylimidazole, N-methylmorpholine, N-ethylmorpholine, triethylamine, N,N′-dimethylpiperazine, N-methyldicyclohexylamine, pentamethyldipropylenetriamine, N-methyl-N′-(2-dimethylamino)-ethyl-piperazine, tributylamine, pentamethyldiethylenetriamine, N,N-dimethylcyclohexylamine, hexamethyltriethylenetetramine, heptamethyltetraethylenepentamine, pentamethyldipropylenetriamine, triethanolamine, dimethylethanolamine, bis(dimethylaminoethyl) ether, tris(3-dimethylamino)-propylamine, and 1,8-diazabicyclo[5.4.0]undecene.

14. The flower pot according to claim 1, characterized in that The dosage of the amine catalyst is 0.05-0.15% of the total weight of the isocyanate and the silane coupling agent.

15. The flower pot according to claim 1, characterized in that: The silane coupling agent is 3-glycidyloxypropyl triethoxysilane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl methyl dimethoxysilane, 3-glycidyloxypropyl methyl diethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl triethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-aminopropyl methyl diethoxysilane, 3-aminopropyl methyl dimethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, N-2-aminoethyl-3-aminopropyl methyl diethoxysilane, N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane, N-2-aminoethyl-3-aminopropyl triethoxysilane, N-2-aminoethyl-3-aminopropyl trimethoxysilane, 3-mercaptopropyl triethoxysilane.

16. The flower pot according to claim 1, characterized in that The amount of the silane coupling agent used is 1.05 to 1.25 times the molar amount of isocyanate in the reaction system.

17. The flowerpot according to any one of claims 1 to 4, characterized in that: The hydroxy silicone oil is one or more of dimethyl hydroxy silicone oils.

18. The flowerpot according to any one of claims 1 to 4, characterized in that: The structural formula of the hydroxyl silicone oil is HO[(CH3)2SiO] n H, where 3 < n < 700, is a linear polymer with a main chain composed of repeating silicon-oxygen bonds, methyl groups as side chains, and hydroxyl groups as end groups.

19. The flowerpot according to any one of claims 1 to 4, characterized in that: The alkoxy silicone oil refers to silicone oil obtained by the end-capping reaction of dimethylhydroxy silicone oil and alkoxysilane.

20. The flower pot according to claim 19, characterized in that The structural formula of alkoxysiloxane is (CH3O)3SiO[(CH3)2SiO] m Si(OCH3)3, where 3 < m < 700, is a linear polymer with a repeating silicon-oxygen bond as the main chain, methyl groups as side chains, and alkoxy groups as end-caps.

21. The flower pot according to claim 1 or 2, characterized in that: In component A, the filler is selected from one or more of mica powder, talc powder, diatomaceous earth and calcium carbonate.

22. The flower pot according to claim 21, characterized in that In component A, the filler is selected from diatomaceous earth and calcium carbonate.

23. The flower pot according to claim 1, characterized in that In the B component, the catalyst is dibutyltin dilaurate, stannous octoate, and dibutyltin diacetate.

24. The flower pot according to claim 1, characterized in that In component B, the crosslinking agent is selected from ethyl orthosilicate, propyl orthosilicate and methyltrimethoxysilane.

25. The flower pot according to claim 1, characterized in that In the B component, the filler is selected from one or more of mica powder, talc powder, diatomaceous earth and calcium carbonate.

26. The flower pot according to claim 25, characterized in that In the B component, the filler is selected from diatomaceous earth and calcium carbonate.

27. The flower pot according to claim 1 or 2, characterized in that: The chemical fertilizers include potassium nitrate, urea, potassium chloride, ammonium phosphate, potassium sulfate, ammonium sulfate, boric acid, calcium nitrate, manganese sulfate, superphosphate, zinc sulfate, magnesium sulfate, copper sulfate, iron sulfate, and ammonium molybdate.

28. The flower pot according to claim 27, characterized in that The chemical fertilizers include two or more of potassium nitrate, calcium nitrate, superphosphate, magnesium borate, copper sulfate and iron sulfate.

29. A method for preparing a flowerpot according to any one of claims 1 to 28, characterized in that: The raw materials in component A are mixed to obtain component A, the raw materials in component B are mixed to obtain component B, the raw materials in component C are mixed and stirred to form mud, and then the mud is prepared into fertilizer particles, dried and solidified to obtain component C, and components A, B and C are mixed and poured into a flower pot mold, heated and solidified at 50-80° C., and demolded to obtain a flower pot.

30. The preparation method according to claim 29, characterized in that: The fertilizer particles have a particle size of 1 to 5 mm.

31. The preparation method according to claim 30, characterized in that: The fertilizer particles are fertilizer particles with a particle size of 2 to 4 mm.