WO2009143655A1

WO2009143655A1 - Alkyd resin emulsion - sulfur multilayer-coated controlled release fertilizer and production thereof

Info

Publication number: WO2009143655A1
Application number: PCT/CN2008/001064
Authority: WO
Inventors: 万连步; 于兵; 范玲超; 解玉洪
Original assignee: 山东金正大生态工程股份有限公司
Priority date: 2008-05-30
Filing date: 2008-05-30
Publication date: 2009-12-03

Abstract

An alkyd resin emulsion - sulfur multilayer-coated controlled release fertilizer comprises a core material (1) and a coating layer material coated on the core material (1). Said coating layer material comprises a sulfur layer (2), a polymer layer (3) comprising alkyd resin emulsion coated on the sulfur layer (2) and optional inorganic layer comprising inorganic powder coated on the polymer coating layer (3).

Description

Alkyd resin emulsion-sulfur composite coated controlled release fertilizer and preparation method thereof

The invention relates to a coated controlled release fertilizer, and more particularly to an alkyd resin emulsion-sulfur composite coated controlled release fertilizer and a preparation method thereof, and belongs to the technical field of materials and fertilizer production. Background technique

Controlled Release Fertilizer The development direction of the bar industry, especially the controlled release fertilizer with excellent performance, has received wide attention. Sulphur-coated urea (scu), which is a sulphur-coated agent, is an earlier industrialized slow-release fertilizer, and its preparation techniques are described in a number of patents such as US 3,295,950, US 3,342,577, and US 3,877,415. The preparation of the sulfur-coated fertilizer is usually carried out in a fluidized bed by first preheating the fertilizer particles in a fluidized bed to a certain temperature, and then spraying the molten liquid sulfur through the nozzle on the fertilizer particles due to the low temperature of the surface of the particles. At the crystallization temperature of sulfur, liquid sulfur solidifies upon contact with the surface of the particles. When the sulfur is sprayed to a certain amount, a continuous sulfur film is formed on the surface of the fertilizer particles. Due to the low cost of sulfur and the simple production process, this type of product has been well applied. However, the maximum defect in the presence of sulfur-coated fertilizers has poor nutrient controlled release properties. Due to the poor impact resistance and abrasion resistance of sulfur coatings, sulfur-coated fertilizers are highly susceptible to sulfur membranes during production, packaging, transportation and storage. Damage; In addition, due to the higher melting point of sulfur, the uniformity of the sulfur film is not easily controlled during the production process, resulting in coatings on some of the particles in the product being too thin or even forming a continuous film. Sulfur-coated fertilizer is a slow-release fertilizer that has poor controllability of plant nutrients and does not achieve the control of dryness of plant nutrients in the true sense. It is generally believed that the release of nutrients from sulphur-sweetened fertilizers includes both the passage of nutrients through the collapse of the sulphur coating and the diffusion of coating defects. People often use the method of increasing the thickness of the sulfur coating to delay the collapse time of the sulfur coating, thereby delaying the release time of the fertilizer nutrients; and the diffusion of nutrients through the defects of the sulfur coating layer tends to lead to the rapid release of nutrients, thus the coating defects Control is very important in the preparation of sulfur-coated fertilizers. Although coating defects can also be controlled in part by the thickness of the coating, it is often necessary to spray a relatively large amount of sulfur to achieve the desired effect. As a result, the sulfur content in the product is increased, which reduces the effective content of the fertilizer. Use can lead to acidification of the soil, which limits the scope of use of the product.

In order to make the sulfur-coated fertilizer have better impact strength and obtain better controlled release properties, Multi-layer composite coated controlled-release fertilizers (see, for example, US Pat. No. 3,295,950, US Pat. No. 3,991,225, US Pat. No. 5,219,465). This type of product is used to eliminate the disadvantages of the sulfur-coated layer by applying a layer of sealant on the surface of the sulfur-coated fertilizer. The sealant includes organic substances such as paraffin and polyolefin. Since these sealants have a certain viscosity, it is also necessary to apply a layer of a modifier on the surface after sealing, which partially improves the mechanical properties and controlled release properties of the sulfur-coated fertilizer.

Resin-coated controlled-release fertilizers can overcome the above-mentioned drawbacks of sulfur-coated fertilizers. For related patents, see, for example, US 3,223,518, US 3,475,154, US 4,019,890, US 4,804,403, WO 02/00573. Since the nutrients in such controlled release fertilizers are mainly released by diffusion of the membrane, the dry release of fertilizer nutrients can be controlled by the composition and structure of the polymer membrane. However, the disadvantage of such controlled release fertilizers is that the cost of the resin coating material is high, and the use of a large amount of organic solvents inevitably causes waste of energy and resources, and at the same time endangers the environment and personal health.

Therefore, the development of coated fertilizers with low-cost and polymer-coated fertilizers with excellent wear resistance, impact resistance and good controlled release properties has always been a hot issue in the field of controlled release fertilizer technology. Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide an environmentally friendly polymer-sulfur composite coated controlled release fertilizer which overcomes the problems associated with current controlled release fertilizers. The polymer coating agent used therein can eliminate the harm to the human body and the environment caused by the organic solvent-based polymer coating agent, reduce the cost of the polymer coating agent, and obtain a controlled release fertilizer with good controlled release properties.

The object is achieved by an alkyd resin emulsion-sulfur composite coated controlled release fertilizer, which consists of a fertilizer core and a coating film on the outer side of the fertilizer core, characterized in that the coating film comprises a sulfur film and the sulfur film. A polymer film containing an alkyd resin emulsion coating agent and an inorganic layer optionally containing an inorganic powder on the polymer film.

The invention also provides a method for preparing the above alkyd resin emulsion-sulfur composite coated controlled release fertilizer, comprising: in a fluidized bed, preferably in a boiling or rotary fluidized bed, first coating the surface of the fertilizer particles Sulfur forms a sulfur film, and then the alkyd resin emulsion coating agent is coated on the surface of the sulfur film to form a polymer film, and the alkyd resin emulsion coating agent is preferably sprayed on the surface of the sulfur film through a double-flow nozzle. And an encapsulating process of optionally coating the inorganic film on the polymer film to form an inorganic layer. In the coated controlled release fertilizer of the present invention, the alkyd resin emulsion coating agent used in the medium completely eliminates the environmental harm caused by the organic solvent in the conventional polymer coating agent because the medium is water. Compared with other synthetic resins, the alkyd resin emulsion coating agent of the invention is mainly a natural renewable vegetable oil, which has low dependence on petroleum and low cost; and the vegetable oil and fatty acid fragments on the polymer chain are also The polymer film is imparted with excellent biodegradability; since the preparation process is based on small molecular materials, the composition and structure of the film-forming polymer can be adjusted by adjusting the polymerization formula and process to achieve the purpose of accurately regulating the release of fertilizer nutrients. At the same time, since the polymer coating material contains functional groups capable of association with water molecules, the materials also have certain water retention properties.

Further, in a further preferred embodiment of the present invention, the alkyd resin emulsion-sulfur complex coated controlled release fertilizer of the present invention further comprises an outermost layer containing an inorganic powder. In the preferred embodiment, the inorganic layer containing the inorganic powder as the outermost layer not only has anti-adhesion and anti-wear properties, but also partially functions to regulate nutrient release.

For the alkyd resin emulsion-sulfur composite coated controlled release fertilizer of the present invention, since the inner coating layer is sulphur, and the sulfur film is a polymer film formed by using an alkyd resin emulsion as a coating agent, it has a sulfur package. The advantages of membrane fertilizer and polymer coated fertilizer, in addition to low cost, good impact and abrasion resistance, and excellent controlled release properties, are also non-toxic, non-polluting, simple in production process during production and use, and The residual polymer film is biodegradable in the soil. DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing the alkyd resin emulsion-sulfur composite coated controlled release fertilizer of the present invention. The alkyd resin emulsion-sulfur composite coated controlled release fertilizer granule of the invention has a fertilizer core, a sulfur film layer and a polymer film layer from the inside to the outside. detailed description

The process for preparing an alkyd resin emulsion-sulfur composite coated controlled release fertilizer comprises the preparation of an alkyd resin emulsion coating agent and a fertilizer coating. The alkyd resin emulsion coating agent of the invention mainly comprises an alkyd resin prepolymer. In a particular embodiment of the invention, an alkyd prepolymer is first prepared, then neutralized with a base, optionally with an emulsifier, optionally with water, and added The polymer emulsion coating agent of the present invention is obtained by a drier.

(1) Preparation of alkyd resin prepolymer

The alkyd resin prepolymer used in the present invention is preferably composed of a vegetable oil and/or a plant-derived fatty acid, a polyhydric alcohol, at least one acid anhydride selected from the group consisting of a c ₄ -c ₂₂ synthetic fatty acid, a c ₄ -c ₂₂ synthetic fatty acid, A raw material composition of a component of an aromatic acid or an aromatic acid anhydride is obtained by a copolycondensation reaction.

In a preferred embodiment of the present invention, the vegetable oil used for preparing the alkyd resin prepolymer is, for example, selected from one or more of a drying oil and a semi-drying oil, and examples thereof include linseed oil, tung oil, dehydrated castor oil, Soybean oil, cottonseed oil, Nasker oil, etc. The plant-derived fatty acid is, for example, selected from one or more of oleic acid, linoleic acid, linolenic acid, tall oil, and rosin. Since some fatty acids such as oleic acid, linoleic acid, linolenic acid and the like are derived from fats and oils, in practice, these fatty acids can be obtained in situ by alcoholysis of fats and oils. The polyol is, for example, selected from one or more of glycerin, trimethylolpropane, pentaerythritol, sorbitol and diethylene glycol, preferably glycerol, trimethylolpropane and pentaerythritol. The C ₄ -C ₂₂ synthetic fatty acid and its anhydride are preferably monobasic or polybasic acids having _{4 to} ₂₂ , preferably 4 to 12, and anhydrides thereof, such as maleic acid, maleic anhydride, fumaric acid, caproic acid And citric acid, adipic acid, sebacic acid, more preferably C ₄ -C ₂₂ dibasic acid and anhydride thereof, especially adipic acid, sebacic acid and anhydride thereof. The aromatic acid and its anhydride are preferably selected from the group consisting of aromatic monobasic acids, aromatic dibasic acids, aromatic tribasic acids and anhydrides thereof, and specific examples thereof include benzoic acid, phthalic acid, phthalic anhydride, and Benzoic acid, trimellitic acid, trimellitic anhydride and the like are preferably aromatic dibasic acids, tribasic acids and anhydrides thereof, especially phthalic anhydride, isophthalic acid, trimellitic acid and trimellitic anhydride. The aromatic acids and anhydrides may be unsubstituted or substituted with one or more substituents selected from a wide ^ alkyl, dC ₆ alkyl! Substituted by a substituent of L&, dC ₆ haloalkyl, halogen, nitro. The halogen or cycline is selected from the group consisting of fluorine, chlorine, bromine and iodine. The alkyl moiety of the dC ₆ alkyl and C6 alkane and C,-C ₆ haloalkyl refers to a saturated straight or branched hydrocarbon group having from 1 to 6 carbon atoms, especially from 1 to 4, such as a fluorenyl group. , ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-mercaptopropyl, 1,1-didecylethyl, pentyl, 1-decylbutyl , 2-mercaptobutyl, 3-methylbutyl, 2,2-dimercaptopropyl, 1-ethylpropyl, hexyl, 1,1-dimercaptopropyl, 1,2-diindole Propyl, 1-decylpentyl, 2-methylpentyl, 3-decylpentyl, 4-decylpentyl, 1,1-dimethylbutyl, 1,2-didecyl Base, 1,3-dimercaptobutyl, 2,2-dimethylbutyl, 2,3-dimethyl Butyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimercaptopropyl, 1,2,2-trimethylpropane Base, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl. The C,-C ₆ alkyl group refers to a linear or branched saturated hydrocarbon group having a plurality of groups, wherein some or all of the hydrogen atoms of these groups may be replaced by the above halogen atoms, and examples thereof include a chloroantimonyl group, Bromomethyl, dichloromethyl, trichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, chlorofluoromethyl, dichlorofluoroindolyl, chlorodifluoroindolyl, 1-chloroethyl , 1-light ethyl, 1-fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-chloro-2-fluoroethyl, 2 -Chloro-2,2-difluoroethyl, 2,2-dichloro-2-fluoroethyl, 2,2,2-trichloroethyl, pentafluoroethyl, and the like. The C,-C ₆ alkoxy group means a straight-chain or branched saturated hydrocarbon group having 1 to 6 carbon atoms which is bonded via an oxygen atom, and examples thereof include a decyloxy group, an ethoxy group, and an OCH ₂ -C ₂ H _{5 group.} , OCH(CH ₃ ) ₂ , n-butoxy, OCH(CH ₃ )-C ₂ H ₅ , OCH ₂ -CH(CH ₃ ) ₂ , OC(CH ₃ ) ₃ , n-pentyl, 1-methylbutyl L &, 2-mercaptobutyl, 3-methylbutyl, 1,1-dimercaptopropene, 1,2-dimethylpropane, 2,2-dimethyl-propyl L^, 1-ethyl Propyloxy, n-hexyl, 1-methylpentyl, 2-mercaptopentyl, 3-mercaptopentyloxy, 4-methylpentyl L&, 1,1-dimethylbutoxy, 1,2- Dimethylbutoxy, 1,3-didecylbutoxy, 2,2-dimethylbutoxy, 2,3-didecylbutoxy, 3,3-didecylbutoxy , 1-ethylbutoxy, 2-ethylbutoxy, 1,1,2-trimethylpropanyl L^, 1,2,2-trimethylpropanol L^, 1-ethyl-1- Methyl propoxy, 1-ethyl-2-methylpropoxy and the like.

The copolycondensation reaction in the present invention can be carried out according to a copolycondensation method known to those skilled in the art. The copolycondensation reaction temperature is, for example, 100 to 280"C, preferably 140 to 250X; and the polymerization reaction time is, for example, 1 to 24 hours, preferably 4 to 12 hours. The end point of the polymerization reaction and the mass of the obtained alkyd resin pass through the acid value of the resin. To control. The acid value of the resin refers to the number of grams of KOH (unit is mgKOH / g resin) consumed by neutralizing 1 gram of resin. The invention is in accordance with the GB/T2895-1982 standard, with an equal volume ratio of ethanol and diethyl ether. The solvent was mixed to determine the acid value of the resin. The inventors have found through research that the acid value of the obtained alkyd resin prepolymer affects the performance of the polymer as a coating agent in the present invention. The larger the acid value of the acid resin prepolymer, the better the hydrophilicity, the easier it is to form a polymer emulsion, but at the same time the higher the hydrophilicity of the formed coating agent, resulting in the controlled release time of the controlled release fertilizer. In the present invention, it is advantageous that the acid value of the alkyd resin prepolymer used is 10 to: 50 mg KOH / g resin, preferably 20 to; 20 mg KOH / g resin, more preferably 30 to 80 mg KOH / resin, most preferably 40 to 70 mg KOH / g resin. In the present invention, the composition of the raw material composition for the polymerization reaction can be adjusted to a large range as needed, wherein the amount of the vegetable oil and/or plant-derived fatty acid and the molar amount of the hydroxyl group and the compound in the raw material composition system are The ratio affects the acid value of the prepolymer and the viscosity of the system. The greater the viscosity of the alkyd prepolymer, the more cosolvents are used in the preparation of the coating agent described below. Preferably, the vegetable oil and/or plant-derived fatty acid is used in an amount of 30 to 70% by weight, more preferably 40 to 60% by weight based on the total weight of the raw material composition; and the molar ratio of the hydroxyl group to the carboxyl group in the raw material composition system is preferably 0.8- 1.4, more preferably 0.9 to 1.3.

In the present invention, the alkyd resin prepolymer may be prepared by an alcoholysis method or a fatty acid method, and the main difference between the two is that the former is based on vegetable oil, and the latter is based on fatty acids derived from vegetable oil. The present invention is preferably an alcoholysis process. The copolycondensation reaction can be carried out in the air or under the protection of an inert gas, preferably in an inert gas, preferably an inert gas. The copolycondensation reaction may be carried out in a solvent or in a molten state, preferably a melt copolycondensation process.

(A) alcoholysis

The alcoholysis method used in the present invention can be carried out by an alcoholysis method well known to those skilled in the art. In a preferred embodiment, a vegetable oil, a polyol and at least one component selected from the group consisting of C ₄ -C ₂₂ synthetic fatty acids, anhydrides of c ₄ -c ₂₂ synthetic fatty acids, aromatic acids, anhydrides of aromatic acids are added to the kettle. The reaction is carried out at a temperature of 100 to 280" C, preferably 140 to 250, for 1 to 24 hours, preferably 4 to 12 hours, during which time the water formed in the reaction is removed by a water eliminator. After cooling, an alkyd resin prepolymer is obtained.

In a further preferred embodiment, the vegetable oil, the polyol and the dibasic acid (and/or its anhydride) are first charged into a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas, and the temperature is raised to 160 to 260. 0.5-hour, preferably 200-240, reaction for 2-4 hours. Then, the temperature is lowered to 120 to 200X:, other polybasic acid (and / or its anhydride) is added, and the reaction is kept for at least 0.5 hours, and the water formed in the reaction is removed in time by a water eliminator. Optionally, 2 to 20% by weight of rosin, preferably 3 to 10 parts by weight, based on the total weight of the resin is added at a temperature of 130 to 160. /. And react at this temperature for 5 minutes to 2 hours, preferably 10 minutes to 0.5 hours. After cooling, an alkyd prepolymer having a certain acid value is obtained.

(B) fatty acid method

The fatty acid method used in the present invention can be carried out by a fatty acid method well known to those skilled in the art. In a preferred embodiment, the plant-derived fatty acid, polyol and at least one are first a component selected from the group consisting of C ₄ -C ₂₂ synthetic fatty acids, acid anhydrides of C ₄ -C ₂₂ synthetic fatty acids, aromatic acids, aromatic acid anhydrides, is added to the reaction vessel, and reacts at a temperature of 100 to 280", preferably 140,250. ~24 hours, preferably 4 to 12 hours, during which time the water formed in the reaction is removed by a water eliminator. After cooling, an alkyd resin prepolymer is obtained.

In a further preferred preparation method, the plant-derived fatty acid, polyol and dibasic acid (and/or its anhydride) are first added to a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas, and the temperature is raised to 160~260" reaction 0.5~6 hours, preferably 200~240" reaction for 2~4 hours, and remove the water formed in the reaction with water eliminator in time, then cool down to 120~200", add other polyacids (and / or Anhydride), keep the reaction for at least 0.5 hours, and remove the water formed in the reaction with a water eliminator. Optionally, add 2~20% by weight of rosin, preferably 3~10 weight, of the total weight of the resin when cooling to 130~160. /«, and react at this temperature for 5 minutes to 2 hours, preferably 10 minutes to 0.5 hours. After cooling, an alkyd prepolymer having a certain acid value is obtained.

(2) Preparation of alkyd resin emulsion coating agent

The preparation of the alkyd resin emulsion coating agent of the invention comprises the following steps:

The alkyd prepolymer is neutralized with a base,

Optionally adding an emulsifier,

Optionally adding water, and

Add a drier.

In a preferred embodiment, the above alkyd resin prepolymer is heated and melted, and its temperature is controlled at 25 to 120 ° C, preferably 40 to 90. C, more preferably 50~80. C. Then, a base is added to the above alkyd prepolymer under stirring. Any one or more of inorganic bases and organic bases conventionally used for neutralization, examples of which include alkali metal hydroxides, alkaline earth metal hydroxides, amines, etc., such as sodium hydroxide And potassium hydroxide, ammonia, triethylamine, trimethylamine, triethanolamine, morpholine, preferably ammonia, triethylamine, tridecylamine, sodium hydroxide and potassium hydroxide. The base is preferably used in the form of an aqueous solution. The degree of neutralization is preferably such that the pH of the above alkyd prepolymer system after neutralization is 5 to 10, preferably 7 to 9.

Optionally, an emulsifier is optionally added to the system, preferably an emulsifier or an a mixture of an anionic emulsifier and a nonionic emulsifier. The anionic emulsifier is one or more of all conventional anionic emulsifiers, for example, a fatty acid having a C ₈ -C ₁₈ alkyl group. Sodium RCOONa, sodium sulphate ROS0 ₃ Na, sodium alkyl sulfonate RS0 ₃ Na

Sodium RC ₆ H ₄ S0 ₃ Na, sodium alkyl diphenyl ether disulfonate, disproportionated rosin and sodium alkylate. The nonionic emulsifier is one or more of all conventional nonionic emulsifiers, such as polyoxyethylene sorbitan fatty acid esters, alkyl sulfonated polyoxyethylene ethers, pit-based polyoxyethylene ethers. Classes, etc. The anionic emulsifier is preferably used in an amount of from 0 to 3.0% by weight based on the weight of the alkyd resin, and the nonionic emulsifier is preferably used in an amount of from 0 to 5.0% by weight.

If desired, water may be further added to the neutralized alkyd prepolymer system. For example, the temperature is 30 to 95 with stirring. C, preferably 45~85. Water is added to the alkyd prepolymer system of C, preferably deionized water and distilled water, emulsified and cooled to room temperature. An alkyd prepolymer emulsion having a desired solid content can be formulated by adding water as needed.

A drier is added to the neutralized alkyd prepolymer system at room temperature, and the mixture is stirred and mixed to obtain a polymer emulsion coating agent. The drier is a drier known to those skilled in the art. The drier comprises a primary drier and, if desired, a drier and/or a drier active. The primary drier may be used alone or in combination with one or more of a drier and/or a drier active. The main drier is, for example, selected from one or more of a cobalt salt and a manganese salt, preferably cobalt naphthenate or manganese naphthenate in an amount of 0.005 to 0.5% by weight based on the weight of the alkyd resin prepolymer in the system. Preferably, it is 0.03 to 0.2% by weight. The drier is, for example, selected from one or more of lead, calcium, zinc, iron, cerium, zirconium salts, preferably naphthenate, in an amount of from 0 to 0.5 by weight of the alkyd prepolymer in the system. % by weight, preferably 0.01 to 0.5% by weight. The wicking active agent is referred to as "active agent A" in the present invention and is composed of 38 parts by weight. /. of. - phenanthroline, 22% by weight of ethyl hexanoate and 40% by weight of n-butanol, the amount of which is 0 to 2.0% by weight, preferably 0.05 to 1.0% by weight, based on the weight of the alkyd resin prepolymer, It is preferably 0.1 to 0.8% by weight.

It should be pointed out that in the case of adding an emulsifier and/or adding water to the alkyd prepolymer system, the order of addition of the emulsifier, water and drier is not important, and the alkyd prepolymer can be used as a base. After neutralization, join in any order.

In the present invention, the particle size of the latex particles in the polymer emulsion is preferably from 50 nm to 5 μm, more preferably from 60 nm to 1 μm, still more preferably 70 300 nm. Among them, nano-sized and sub-micron-sized latex particles are preferred, and the advantage is that the emulsion stability is good and the formed polymer film is dense.

The solid content of the polymer emulsion coating agent of the invention is preferably 5 to 70% by weight, preferably 10 to 50% % by weight, more preferably 15 to 40% by weight. The viscosity is preferably from 10 to 5,000 mPa·s, more preferably from 50 to 2,000 mPa·s, still more preferably from 80 to 500 mPa·s.

(3) coated controlled release fertilizer and preparation method thereof

For the purposes of the present invention, the fertilizer core may be any water-soluble fertilizer, for example, a single fertilizer such as nitrogen fertilizer such as urea, phosphate fertilizer such as ammonium phosphate, potassium fertilizer such as potassium sulfate, compound fertilizer of any ratio of NPK, compound fertilizer , and other water-soluble plant nutrients.

In a preferred embodiment of the present invention, the inorganic powder is one or more selected from the group consisting of talc, diatomaceous earth, montmorillonite, kaolin, calcium carbonate, bentonite, attapulgite and sepiolite powder, preferably Talc powder, diatomaceous earth and calcium carbonate are more preferably micron-sized inorganic powders. The particle size of the inorganic powder is preferably less than 20 microns, more preferably less than 10 microns, and most preferably less than 5 microns. Most preferred are talc, diatomaceous earth or calcium carbonate having a particle size of less than 5 microns.

The method for preparing the alkyd resin emulsion-sulfur-coated controlled release fertilizer of the present invention comprises first applying sulfur to a surface of a fertilizer particle to form a sulfur film in a fluidized bed, and then coating the alkyd resin emulsion coating agent to the The surface of the sulfur film forms a polymer film, preferably an alkyd resin emulsion coating agent is sprayed on the surface of the sulfur film through a two-flow nozzle, and optionally an inorganic powder is coated on the polymer film to form a coating process of the inorganic layer. The coating process is preferably carried out in a boiling or rotary drum fluidized bed.

The coating process of sulfur in the present invention can be carried out by any conventional coating method in the art. In a more preferred embodiment, molten liquid sulfur is sprayed onto the moon-filled particles to form a sulfur film using a fluidized bed coating process conventional in the art.

The coating of the alkyd resin emulsion coating agent in the present invention employs a conventional coating process in the art, preferably by a fluidized bed coating process. The temperature in the fluidized bed is preferably from 30 to 95 °C.

In a further preferred embodiment, the fertilizer granules are placed in a boiling or rotary fluidized bed and preheated, e.g., preheated to a preferred temperature of from 60 to 95. C. The sulfur is heated and melted, and then molten sulfur having a temperature of preferably 130 to 170 ° C is preferably sprayed on the fertilizer particles through a double-flow nozzle to form a uniform sulfur film. The thickness of the sulfur layer can be adjusted as needed. For the same thickness, the amount of sulfur varies depending on the size of the fertilizer particles. The smaller the fertilizer particles, the larger the amount of sulfur used. Usually, the thickness of the sulfur layer is controlled to be between 30 and 300 microns, preferably between 50 and 150 microns. The weight of the sulfur film is preferably from 5 to 30%, more preferably from 7 to 20%, based on the total weight of the fertilizer.

Cooling the sulfur coated fertilizer granules, preferably to 60~95 ° C, and then to the alkyd tree at room temperature The lipid emulsion coating agent, preferably preheated, for example, an alkyd resin emulsion coating agent preheated to at most 80 ° C is uniformly sprayed onto the sulfur coated fertilizer particles by a two-flow nozzle to form a continuous uniform polymer film. In a more preferred embodiment, the alkyd resin emulsion coating agent is uniformly sprayed onto the surface of the sulfur-coated fertilizer particles through a two-flow nozzle. The thickness of the polymer film layer can be adjusted as needed, and is calculated as a dry matter of the polymer. The amount of the polymer is preferably from 0.5 to 10%, more preferably from 1 to 5%, based on the total weight of the controlled release fertilizer.

If necessary, the inorganic powder is sprayed into a fluidized bed of preferably 30 to 95 ° C, more preferably 70 to 95, to uniformly coat the surface of the polymer-coated fertilizer particles to form an inorganic layer. . The amount of the inorganic powder is usually from 0 to 10% by weight, preferably from 0.5 to 5% by weight, more preferably from 1 to 3% by weight based on the total weight of the coated controlled release fertilizer.

Example

The invention is further clarified by the following examples, which are merely intended to illustrate the invention and in no way limit the invention.

The vegetable oils, fatty acids, polyols, polybasic acids, acid anhydrides, driers, sulfurs and inorganic powders used in the examples are all industrial grades, the base used is a chemically pure reagent, and the water used is deionized water.

The nutrient release period of controlled release fertilizers is controlled by 25 percent. C is expressed as the number of days required for immersion in still water to reach 80% of the cumulative nutrient release rate. The specific measurement method is as follows: The controlled release fertilizer is immersed in 7J at 25 ° C, and the nutrients in the sample are dissolved into the water through the membrane. The total nitrogen content of the dissolved solution is determined by the titration method after distillation according to GB/T 8572, according to GB/T. 8573 was determined by ammonium vanadium molybdate colorimetric method, and the dissolved potassium content was determined by flame photometer according to GB/T 8574. The time required for the dissolved nutrients to reach 80% of the total nutrient mass is the nutrient release period of the controlled release fertilizer. Example 1

(1) Preparation of alkyd resin prepolymer

480 g of linseed oil, 236 g of trishydroxyhydropropane and 166 g of isophthalic acid were placed in a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas, heated to 235 Torr for 3.5 hours, and then cooled to 175. C. Add 73 g of trimellitic anhydride, react at this temperature for about 3 hours, and remove the water formed in the reaction with a water eliminator. When the acid value of the system reaches 62 KOH mg/g resin, the temperature is lowered to 150. C, add 49 grams of rosin to react for 20 minutes.

(2) Preparation of alkyd resin emulsion coating agent The alkyd resin prepolymer in step (1) is cooled to 65", and 20% by weight of ammonia water is added under stirring to make the pH of the system 7. Then, deionized water is added, the mixture is stirred and uniformly cooled, and then cooled to room temperature. Add 2 g of cobalt naphthenate, 1 g of zirconium naphthenate and 1.5 g of active agent A, and mix well to obtain an alkyd resin emulsion coating agent. The coating agent latex particle size is 143 nm, and the solid content is 35 weight. %, viscosity is 124 mPa.S.

(3) Fertilizer coating formula and process

5 kg of urea with a particle size of 3~5 mm (from Shandong Mingshui Chemical Co., Ltd., 46.4% by weight) ^> in a boiling fluidized bed, preheated to about 80 ° C, then 0.6 kg Liquid sulfur, which was melted and heated to about 145 ° C, was sprayed onto the surface of the urea particles through a two-flow nozzle at a spraying rate of 30 grams per minute. The sulfur coated urea is cooled to about 80 °C and then preheated to about 80 from another dual flow nozzle. 0.5 kg of the above alkyd resin emulsion coating agent of C was sprayed onto the surface of the sulfur coated urea at a spraying rate of 20 g per minute. Finally, 80 g of diatomaceous earth having an average particle diameter of 3 μm was uniformly sprayed onto the surface of the fertilizer at a temperature of about 80 °C.

Based on the dry matter weight, the composition of the obtained alkyd resin emulsion-sulfur composite coated controlled release fertilizer was 85.4% urea, 10.2% sulfur, 3% polymer, and 1.4% diatomaceous earth. The controlled release fertilizer has a nutrient dry release period of 162 days.

Example 2

Same as Example 1, except that the urea in Example 1 was replaced by a compound fertilizer of 2 to 4 mm (the compound fertilizer was from Shandong Jinzhengda Ecological Engineering Co., Ltd., with NP ₂ 0 ₅ -K ₂ 0% by weight Count: 16-16-16).

Based on the dry matter weight, the composition of the obtained alkyd resin emulsion-sulfur composite coated controlled release fertilizer was 85.4%, the sulfur accounted for 10.2%, the polymer accounted for 3%, and the diatomaceous earth accounted for 1.4%. The nutrient release period of the controlled release fertilizer was 266 days.

Example 3

(1) Preparation of alkyd resin prepolymer

190 g of linseed oil, 210 g of dehydrated castor oil, 223 g of trimethylolpropane and 148 g of phthalic anhydride were placed in a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen atmosphere, and the temperature was raised to 225. The reaction was carried out at ° C for 2.5 hours. Then, the temperature is lowered to 170 ° C, 64 g of trimellitic acid is added, and the reaction is carried out at this temperature for about 3.5 hours, and the water formed in the reaction is removed in time by the water eliminator. When the acid value of the system reaches 55 mgKOH/g resin, the temperature is lowered to 160. C, add 60 grams of rosin to react for 15 minutes.

(2) Preparation of alkyd resin emulsion coating agent

The alkyd resin prepolymer in the step (1) is cooled to 75" C, and 20% by weight of ammonia water is added under stirring to adjust the pH of the system to 7.5. Then, deionized water is added, stirred and emulsified uniformly, and then cooled to room temperature. Then add 1.8 g of cobalt naphthenate, 1 g of zirconium naphthenate and 1.5 g of active agent A, and mix uniformly to obtain an alkyd resin emulsion coating agent. The coating agent has a particle size of 196 nm and a solid content of 35. % by weight, viscosity 296 mPa.s.

(3) Fertilizer coating formula and process

5 kg of compound fertilizer with particle size of 2~4 mm (from Shandong Jinzhengda Ecological Engineering Co., Ltd., NP ₂ 0 ₅ -K ₂ 0% by weight: 16-16-16) was charged into the boiling fluidized bed. Inside, preheat to about 80X, then spray 0.5kg of liquid sulfur that is heated to about 140"C through a dual-flow nozzle onto the surface of the fertilizer granules at a spray rate of 30 grams per minute. Cool the sulfur-coated compound fertilizer to about 90V Then, from another double-flow nozzle, 0.3 kg of alkyd resin emulsion coating agent which has been preheated to about 80: is sprayed onto the surface of the sulfur-coated particles at a spraying rate of 20 g per minute. Finally, the average particle diameter of 100 g is 3 μm. The talc powder is evenly sprayed onto the surface of the fertilizer at a temperature of about 80 °C.

Based on the dry matter weight, the composite coated controlled release fertilizers accounted for 87.7% of compound fertilizers, 8.8% of sulfur, 1.8% of polymer membranes, and 1.7% of talc. The controlled release fertilizer has a feeding period of 148 days.

Example 4

(1) Preparation of alkyd resin prepolymer

175 g of linseed oil, 175 g of tung oil, 95 g of cottonseed oil, 215 g of trishydroxyhydropropane, 75 g of phthalic anhydride and 83 g of isophthalic acid were added to the mixer, reflux condenser, thermometer and In a nitrogen-protected reactor, the temperature was raised to 240. C reaction for 2.5 hours. Then, the temperature is lowered to 180 ° C, 48 g of trimellitic acid is added, and the reaction is carried out at this temperature for about 3 hours, and the water formed in the reaction is removed in time by a water eliminator. When the acid value of the system reaches 48 KOH mg / g of resin, the temperature is lowered. At 160 ° C, 50 g of rosin was added and reacted for 20 minutes.

(2) Preparation of alkyd resin emulsion coating agent

The alkyd prepolymer in step (1) is cooled to 70 X: and 20% by weight is added under stirring. Ammonia water makes the pH of the system 7. Then, deionized water was added, stirred and emulsified uniformly, and then cooled to room temperature, and then 2 g of cobalt naphthenate and 2.5 g of the active agent A were separately added and uniformly mixed to obtain an alkyd resin emulsion coating agent. The coating agent has a particle size of 154 nm, a solid content of 35% by weight, and a viscosity of 158 mPa·s.

(3) Fertilizer coating formula and process

5 kg of compound fertilizer with a particle size of 2 to 4 mm (from Shandong Jinzhengda Ecological Engineering Co., Ltd., NP ₂ 0 ₅ -K ₂ 0% by weight: 15-15-15) was charged into boiling fluidization. In the bed, preheated to about 80, and then 0.8 kg of liquid sulfur melted and heated to about 150 was sprayed onto the surface of the fertilizer granules through a two-flow nozzle at a spraying rate of 30 grams per minute. The sulfur-coated compound fertilizer is cooled to about 90 ° C, and then 0.4 kg of the above alkyd resin emulsion coating agent which has been preheated to about 80 is sprayed onto the surface of the coated particles from another double-flow nozzle at a spraying rate of 20 g per minute. . Finally, 100 g of talc powder having an average particle diameter of 3 μm was uniformly sprayed onto the surface of the fertilizer at a temperature of about 80 °C.

Based on the dry matter weight, the composite coated controlled release fertilizer composition accounted for 82.8% of compound fertilizer, 13.2% of sulfur, 2.3% of polymer and 1.7% of talc. The controlled release fertilizer has a shelf life of 310 days.

Example 5

The same as in Example 4, except that the compound fertilizer of Example 4 was replaced with urea having a particle size of 3 to 5 mm (from Shandong Mingshui Chemical Co., Ltd., 46.4% by weight).

Based on the dry matter weight, the composition of the obtained alkyd resin emulsion-sulfur composite coated controlled release fertilizer was 82.8% of urea, 13.2% of sulfur, 2.3% of polymer and 1.7% of talc. The nutrient release period of the controlled release fertilizer is 180 days.

Example 6

(1) Preparation of alkyd resin prepolymer

300 g of tung oil, 125 g of soybean oil, 112 g of trishydroxylpropane, 70 g of pentaerythritol and 162 g of isophthalic acid were added to a reactor equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen gas, and the temperature was raised to 235. C reacted for 3 hours. Then cool down to 180. C, adding 50 g of trimellitic anhydride, reacting at this temperature for about 3 hours, and removing the water formed in the reaction with a water remover in time. When the acid value of the system reaches 42 KOH mg / resin, the temperature is lowered to 155 ° C, and 52 g of rosin is added. Reaction for 20 minutes. (2) Preparation of alkyd resin emulsion coating agent

The alkyd prepolymer in the step (1) was cooled to 70, and 20% by weight of aqueous ammonia was added under stirring to adjust the pH of the system to 7. Then add 1.5 g of sodium dodecylbenzene sulfonate and 2 g of octylphenol polyoxyethylene ether, mix and tick, then add deionized water, stir and emulsifie, then cool to room temperature, then add 1 g of naphthenic acid respectively. Cobalt, 1 g of naphthenic acid and 1.5 g of active agent A are uniformly mixed to obtain an alkyd resin emulsion coating agent. The coating agent has a particle size of 72 nm, a solid content of 30% by weight, and a viscosity of 149 mPa·s.

(3) Fertilizer coating formula and process

5 kg of compound fertilizer with a particle size of 2~4 mm (from Shandong Jinzhengda Ecological Engineering Co., Ltd., NP ₂ 0 ₅ -K ₂ 0% by weight: 15-15-15) was charged into the boiling fluidized bed. Inside, preheat to about 80"C, then spray 0.6 kg of liquid sulfur heated to about 150 X through a double-flow nozzle onto the surface of the fertilizer granules at a spray rate of 30 grams per minute. Cool the sulfur-coated compound fertilizer to about 90", then spray 0.45 kg of the above alkyd emulsion coating agent preheated to about 80" from another double-flow nozzle onto the surface of the coated sulfur particles at a spraying rate of 20 g per minute. Finally, 100 g of average particle size The 3 micron talc powder was evenly sprayed onto the surface of the fertilizer at a temperature of about 80 °C.

Based on the dry matter weight, the composite coated controlled-release fertilizers accounted for 85.7% of compound fertilizers, 10.3% of sulfur, 2.3% of polymers, and 1.7% of talc. The controlled release fertilizer has a feeding period of 220 days.

Example 7

The same as Example 6, except that the compound fertilizer in Example 6 is made of potassium sulfate having a particle diameter of 3 to 5 mm (produced by Shandong Jinzhengda Ecological Engineering Co., Ltd., 50 in terms of κ ₂ ο % by weight) instead.

Based on the dry matter weight, the composition of the obtained alkyd resin emulsion-sulfur composite coated controlled release fertilizer was 85.6% of sulfuric acid clock, 10.3% by weight of sulfur, 2.4% of polymer and 1.7% of talc. The controlled release fertilizer has a nutrient release period of 158 days.

Example 8

(1) Preparation of alkyd resin prepolymer

163 g of linoleic acid, 215 g of linolenic acid, 82 g of isophthalic acid, 75 g of phthalic anhydride, and 275 g of trishydroxypropane were charged with a stirrer, a reflux condenser, a thermometer and nitrogen In the gas-protected reactor, the temperature was raised to 240 ° C for 3 hours, and the water formed in the reaction was removed in time with a water eliminator, and then cooled to 180. C, 68 g of trimellitic anhydride was added, the reaction was incubated, and the water formed in the reaction was removed in time with a water eliminator. The acid value of the system reached 55 KOH mg/g resin after about 4 hours. Cool down to 150. At 60 C, 60 g of rosin was added for 25 minutes.

(2) Preparation of alkyd resin emulsion coating agent

The alkyd prepolymer in step (1) was cooled to 20% by weight of aqueous ammonia under stirring to bring the system to a pH of 7. Then, deionized water was added, stirred and emulsified uniformly, and then cooled to room temperature, and then 1.5 g of cobalt naphthenate, 1.5 g of zirconium naphthenate and 1.5 g of active agent A were separately added, and uniformly mixed to obtain an alkyd resin emulsion coating agent. The coating agent has a particle size of 98 nm, a solid content of 35 wt%, and a viscosity of 243 mPa·s.

(3) Fertilizer coating formula and process

5 kg of compound fertilizer with particle size of 2~4 mm (from Shandong Jinzhengda Ecological Engineering Co., Ltd., NP ₂ 0 ₅ -K ₂ 0% by weight: 16-16-16) was charged into the boiling fluidized bed. Inside, preheat to about 80, then spray 0.65 kg of liquid sulfur heated to about 150" through a dual-flow nozzle onto the surface of the fertilizer granules at a spraying rate of 25 grams per minute. Cool the sulfur-coated compound fertilizer to about 90 Γ, Then, from the other two-flow nozzle, 0.3 kg of the above alkyd resin emulsion coating agent preheated to about 80 was sprayed onto the surface of the sulfur-coated particles at a spraying rate of 15 g per minute. Finally, the average particle diameter of 100 g was 3.5. The micron carbonic acid is evenly sprayed onto the surface of the fertilizer at a temperature of about 80 °C.

Based on the dry matter weight, the composition of the composite coated controlled release fertilizer was 85.4%, the sulfur accounted for 11.1%, the polymer accounted for 1.8%, and the calcium carbonate accounted for 1.7%. The controlled release fertilizer has a feeding period of 183 days.

Example 9

The same as in the eighth embodiment, except that the compound fertilizer in the embodiment 8 is replaced by urea having a particle size of 3 to 5 mm (from Shandong Mingshui Chemical Co., Ltd., 46.4% by weight), and other formulations and processes. It is identical to the embodiment 8.

Based on the dry matter weight, the composition of the obtained alkyd resin emulsion-sulfur composite coated controlled release fertilizer was 85.4% urea, 11.1% sulfur, 1.8% polymer and 1.7% calcium carbonate. The nutrient dry release period of the controlled dry fertilizer is 135 days.

Example 10 Same as in Example 1, except that calcium carbonate was not used in the coating, and sulfur was first sprayed on the surface of the fertilizer particles, and then the coating agent was sprayed onto the surface of the sulfur-coated fertilizer.

Based on the dry matter weight, the composition of the obtained alkyd resin emulsion-sulfur composite coated controlled release fertilizer was 86.6% of urea, 10.4% of sulfur and 3% of polymer. The controlled release fertilizer has a growth period of 110 days.

Claims

Rights request

An alkyd resin emulsion-sulfur composite coated controlled release fertilizer comprising a fertilizer core and a coating film on the outer side of the fertilizer core, characterized in that the coating film comprises a sulfur film, and the alkyd resin is contained outside the sulfur film A polymeric film of an emulsion coating agent and an inorganic layer optionally containing an inorganic powder outside the polymeric film.

The alkyd emulsion-sulfur composite coated controlled release fertilizer according to claim 1, wherein the sulfur accounts for 5 to 30% by weight, preferably 8 to 20% by weight based on the total weight of the coated controlled release fertilizer.

The alkyd resin emulsion-sulfur composite coated dry control fertilizer according to claim 1, wherein the polymer film accounts for 0.5 to 10% by weight of the total weight of the coated dry fertilizer, preferably 1-5. %.

The alkyd resin emulsion-sulfur composite coated controlled release fertilizer according to claim 1, wherein the inorganic powder accounts for 0 to 10% by weight, preferably 0.5 to 5% by weight, more preferably 0% by weight, based on the total weight of the controlled release monthly material. 1~3 wt%.

The alkyd resin emulsion-sulfur composite coated controlled release fertilizer according to any one of claims 1 to 4, characterized in that the alkyd resin emulsion coating agent comprises an alkyd resin prepolymer in a neutralized form. .

The alkyd resin emulsion-sulfur composite coated controlled release fertilizer according to claim 5, wherein the alkyd resin prepolymer has an acid value of 10 to 150 mgKOH/g resin, preferably 20 to 120 mgKOH/g resin, more preferably 30 to 80 mg KOH / g resin, further preferably 40 to 70 mg KOH / g resin.

The alkyd resin emulsion-sulfur composite coated controlled release fertilizer according to claim 5, wherein the alkyd resin emulsion coating agent has a solid content of 5 to 70% by weight, preferably 10 to 50% by weight, more It is preferably 15 to 40% by weight.

The alkyd emulsion-sulfur composite coated controlled release fertilizer according to claim 5, wherein the alkyd resin emulsion coating agent has a viscosity of 10 to 5000 mPa·s, preferably 50 to 2000 mPa·s, More preferably, it is 80-500 mPa.S.

The alkyd emulsion-sulfur composite coated controlled release fertilizer according to claim 5, wherein the alkyd resin emulsion coating agent has a latex particle size of 50 nm to 5 μm, preferably 60 nm to 1 nm. Micron, more preferably 70 to 300 nm.

The alkyd emulsion-sulfur composite coated controlled release fertilizer according to claim 5, characterized in that the alkyd resin emulsion prepolymer is composed of a vegetable oil and/or a plant-derived fatty acid, plural a raw material composition of at least one component selected from the group consisting of C ₄ -C ₂₂ synthetic fatty acids, C ₄ -C ₂₂ synthetic fatty acid anhydrides, aromatic acids, and aromatic acid anhydrides by a copolycondensation reaction,

Wherein the vegetable oil and/or plant-derived fatty acid is used in an amount of 30 to 70% by weight, preferably 40 to 60% by weight based on the total weight of the raw material composition; and the molar ratio of the hydroxyl group to the carboxyl group in the raw material composition is 0.8 to 1.4, preferably 0.9~1.3.

The alkyd emulsion-sulfur composite coated controlled release fertilizer according to claim 10, wherein the vegetable oil is selected from one or more of a drying oil and a semi-drying oil, preferably linseed oil, tung oil, dehydrated hydrazine Sesame oil, soybean oil, cottonseed oil and Nasrell oil; the plant-derived fatty acid is selected from one or more of oleic acid, linoleic acid, linolenic acid, tall oil and rosin; From one or more of glycerin, trimethylolpropane, pentaerythritol, sorbitol and diethylene glycol; the c ₄ -c ₂₂ synthetic fatty acid and its anhydride are selected from the group consisting of c ₄ -c ₂₂ - acid, polybasic acid and An acid anhydride thereof, preferably a c ₄ -c ₂₂ dibasic acid and an acid anhydride thereof, particularly adipic acid, sebacic acid and an anhydride thereof; the aromatic acid and an anhydride thereof are selected from the group consisting of an aromatic monobasic acid, an aromatic dibasic acid, and an aromatic acid. Tribasic acid and its acid liver, especially phthalic anhydride, isophthalic acid, trimellitic acid and trimellitic anhydride.

The alkyd emulsion-sulfur composite coated controlled release fertilizer according to claim 10, wherein the alkyd resin prepolymer is produced by an alcoholysis method or a fatty acid method, preferably an alcoholysis method.

The alkyd emulsion-sulfur composite coated controlled release fertilizer according to claim 10, wherein said copolycondensation reaction is solution copolycondensation or melt copolycondensation, preferably melt copolycondensation.

The alkyd emulsion-sulfur composite coated controlled release fertilizer according to claim 10, wherein the copolycondensation reaction temperature is 100 to 280X, preferably 140 to 250; and the polymerization reaction time is 1 to 24 hours, preferably 4 to 12 hour.

The alkyd resin emulsion-sulfur composite coated controlled release fertilizer according to any one of claims 1 to 4, wherein the inorganic powder is selected from the group consisting of talc, diatomaceous earth, montmorillonite, kaolin, carbonic acid One or more of calcium, bentonite, attapulgite and sepiolite powder, preferably talc, diatomaceous earth and carbonic acid, more preferably micron-sized, preferably less than 5 micron, and further preferably less than 5 micron. Talc, diatomaceous earth and calcium carbonate.

16. A method of preparing an alkyd resin emulsion coating agent according to any of claims 1-15, comprising the steps of:

The alkyd prepolymer is neutralized with a base, Optionally adding an emulsifier,

Optionally adding water, and

Add a drier.

The process for producing an alkyd resin emulsion coating agent according to claim 16, wherein the base is one or more of an inorganic base and an organic base, preferably an alkali metal hydroxide, an alkaline earth metal hydroxide and an amine. More preferred are ammonia water, triethylamine, tridecylamine, sodium hydroxide and potassium hydroxide.

The method for producing an alkyd resin emulsion coating agent according to claim 16, wherein said emulsifier is selected from the group consisting of an anionic emulsifier or a mixture of an anionic emulsifier and a nonionic emulsifier, relative to the weight of the alkyd resin The anionic emulsifier is preferably used in an amount of from 0 to 3.0% by weight. /. The amount of the nonionic emulsifier is preferably from 0 to 5.0% by weight.

The method of preparing an alkyd resin emulsion coating agent according to claim 16, wherein the driers comprise a primary drier and optionally a drier and/or a drier active.

The method for producing an alkyd resin emulsion coating agent according to claim 19, wherein the main drier is selected from one or more of a cobalt salt and a manganese salt, preferably cobalt naphthenate and manganese naphthenate. Preferably, the amount thereof is 0.005 to 0.5% by weight based on the weight of the alkyd resin prepolymer; the drier is selected from one or more of lead, calcium, zinc, iron, cerium and zirconium salts, and the amount thereof is alcohol 0 to 0.5% by weight, preferably 0.01 to 0.5% by weight based on the weight of the acid resin prepolymer; the driers active agent is 38% by weight of phenanthroline, 22% by weight of ethyl hexanoate and 40% by weight The n-butanol is mixed and used in an amount of 0 to 2.0% by weight, preferably 0.05% by weight, based on the weight of the alkyd resin prepolymer.

21. A process for the preparation of an alkyd emulsion-sulphur composite coated controlled release fertilizer according to claims 1-15, which comprises in a fluidized bed, preferably in a boiling or rotary fluidized bed, first The surface of the fertilizer particles is coated with sulfur to form a sulfur film, and then the alkyd resin emulsion coating agent is coated on the surface of the sulfur film to form a polymer film, preferably the alkyd resin emulsion coating agent is passed through the double stream. The nozzle is sprayed on the surface of the sulfur film, and optionally coated with an inorganic powder on the polymer film to form an inorganic layer coating process.