Resin composition for fertilizer coating, solution for fertilizer coating, and slow-release fertilizer

Abstract

The present invention provides a resin composition for fertilizer coating, comprising a polyhydroxyalkanoate resin and having a degree of crystallinity of 15% to 40% as measured by differential scanning calorimetry (DSC). The present invention provides a slow-release fertilizer comprising a fertilizer and a coating layer formed on the fertilizer, wherein the coating layer comprises a polyhydroxyalkanoate resin, and the coating layer has a degree of crystallinity of 15% to 40% as measured by differential scanning calorimetry (DSC).

Description

Resin composition for fertilizer coating, solution for fertilizer coating, and slow-release fertilizer

[0001] The present invention relates to a resin composition for fertilizer coating, a solution for fertilizer coating, and a slow-release fertilizer.

[0002]

[0003] Slow-release fertilizers, which have their surfaces coated with materials such as resin, offer excellent control over the release of fertilizer components, reduce rural labor, and are recognized for their effects in reducing greenhouse gases and environmental burdens such as water pollution.

[0004] Generally, coating materials for slow-release fertilizers are non-biodegradable materials such as PE and PVA combinations, PVDC and acrylic combinations, or polyurethane, which cause problems by remaining in the soil or flowing into water systems after fertilizer release.

[0005] If non-biodegradable materials remain in the soil, there is a risk of crop damage or absorption into the human body due to microplastics, and if these materials flow into water systems, there is a problem of microplastic accumulation in the water.

[0006] As an alternative, biodegradable materials were considered as coating materials for slow-release fertilizers. However, biodegradable materials present a problem in that it is difficult to control the release rate of the fertilizer compared to non-biodegradable materials. Additionally, it is difficult to achieve a uniform coating during the fertilizer application, and adhesion between biodegradable materials occurs, making it difficult to ensure coating processability.

[0007]

[0008] The present invention provides a resin composition for fertilizer coating, a solution for fertilizer coating, and a slow-release fertilizer that exhibit excellent biodegradability in soil and ocean after fertilizer release, controllability of the fertilizer release rate, and excellent coating processability.

[0009]

[0010] The resin composition for fertilizer coating according to the present invention comprises a polyhydroxyalkanoate resin, and the degree of crystallization measured by differential scanning calorimetry (DSC) may be 15% to 40%.

[0011] In one embodiment of the present invention, the number average molecular weight of the polyhydroxyalkanoate resin may be 100,000 g / mol to 800,000 g / mol.

[0012] In one embodiment of the present invention, the polyhydroxyalkanoate resin may include a 3-hydroxybutyrate repeating unit and a 4-hydroxybutyrate repeating unit.

[0013] In one embodiment of the present invention, the polyhydroxyalkanoate resin may contain the 4-hydroxybutyrate repeating unit in an amount greater than 0 mol % and less than or equal to 50 mol %.

[0014] In one embodiment of the present invention, the resin composition for fertilizer coating may include a first biodegradable polyester resin comprising a diol-derived unit, an aliphatic dicarboxylic acid-derived unit, and an aromatic dicarboxylic acid-derived unit.

[0015] In one embodiment of the present invention, the resin composition for fertilizer coating may include a second biodegradable polyester resin having a degree of crystallization of 27% to 60% as measured by the differential scanning calorimeter.

[0016] In one embodiment of the present invention, the content of the polyhydroxyalkanoate resin may be 5 to 30 parts by weight based on 100 parts by weight of the total of the first biodegradable polyester resin and the second biodegradable polyester resin.

[0017] In one embodiment of the present invention, the resin composition for fertilizer coating may include a flow promoter comprising a silicone-based compound.

[0018] In one embodiment of the present invention, the resin composition for fertilizer coating may include an adhesion enhancer comprising a silane coupling agent.

[0019] The fertilizer coating solution according to the present invention may include a polyhydroxyalkanoate resin, a fertilizer coating resin composition having a degree of crystallinity of 15% to 40% as measured by differential scanning calorimetry (DSC), and a solvent.

[0020] In one embodiment of the present invention, the solvent is a Hansen fractionation dispersion parameter (f d ) 0.5 to 0.9, Hansen fractionation polarity parameter (f p ) 0 to 0.3, and Hansen fractionation hydrogen bonding parameter (f h It can be 0.1 to 0.4.

[0021] In one embodiment of the present invention, the content of the resin composition for fertilizer coating may be 1% to 20% by weight based on the total weight of the solution for fertilizer coating.

[0022] The slow-release fertilizer according to the present invention comprises a fertilizer and a coating layer formed on the fertilizer, wherein the coating layer comprises a polyhydroxyalkanoate resin and the degree of crystallization of the coating layer measured by differential scanning calorimetry (DSC) may be 15% to 40%.

[0023] In one embodiment of the present invention, the thickness of the coating layer may be 10 μm to 300 μm.

[0024] In one embodiment of the present invention, the coating layer may comprise a first biodegradable polyester resin comprising a diol-derived unit, an aliphatic dicarboxylic acid-derived unit, and an aromatic dicarboxylic acid-derived unit, and a second biodegradable polyester resin having a degree of crystallinity of 27% to 60% as measured by the differential scanning calorimeter.

[0025] In one embodiment of the present invention, the volume of the coating layer may be 7 volume % to 33 volume % relative to the volume of the fertilizer.

[0026]

[0027] The resin composition for fertilizer coating according to the present invention is environmentally friendly, has excellent adhesion to fertilizer as the degree of crystallization is controlled within a certain range, allows for control of the fertilizer release rate, and can improve coating processability. Furthermore, after the slow-release fertilizer produced from the resin composition for fertilizer coating has exhausted its utility as a fertilizer, the coating residue can be easily decomposed not only in soil but also in the ocean. In addition, a coating layer can be uniformly formed on the fertilizer, allowing for control of the release rate within a certain period required for the function of the slow-release fertilizer.

[0028] In addition, the adhesion between the fertilizer and the resin composition for fertilizer coating is excellent, and the adhesion between the resin compositions for fertilizer coating can be suppressed, thereby ensuring the processability of the fertilizer coating and suppressing the occurrence of adhesion between slow-release fertilizers after fertilizer coating.

[0029] The fertilizer coating solution according to the present invention can have improved mixing properties with the resin composition for fertilizer coating by selecting a solvent having a Hansen fractionation parameter within a certain range. Furthermore, the manufacturing method according to the present invention allows the solvent to be easily volatilized and the amount of residual solvent to be minimized by controlling the temperature range according to the coating process, thereby enabling more efficient recycling of the solvent.

[0030]

[0031] The structural or functional descriptions of the embodiments disclosed in this specification or application are merely illustrative for the purpose of explaining embodiments according to the technical concept of the present invention. Embodiments according to the technical concept of the present invention may be implemented in various forms other than those disclosed in this specification or application, and the technical concept of the present invention is not to be interpreted as being limited to the embodiments described in this specification or application.

[0032] Furthermore, when a component is described as "comprising" in this specification or application, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Additionally, all numerical ranges representing physical properties, dimensions, etc., of components described in this specification or application should be understood to be modified by the term "approximately" in all cases, unless otherwise specifically stated.

[0033] Additionally, 'ppm' in this specification or application refers to a weight basis.

[0034] Additionally, in this specification or application, 'origin' means a component, structure, or the substance itself derived from a certain substance.

[0035] Furthermore, in this specification or application, 'derived functional group' refers to a linker that connects each polymer within the coupled polymer by the coupling agent introduced during the coupling reaction, or a terminal group that remains bound within the polymer or at the polymer ends because it does not participate in the coupling reaction between the polymers.

[0036]

[0037] The resin composition for fertilizer coating according to the present invention may include a polyhydroxyalkanoate resin.

[0038] The above polyhydroxyalkanoate resin may be a thermoplastic polyester polymer that accumulates within microbial cells. As a biodegradable material, the polyhydroxyalkanoate resin is compostable, does not generate toxic waste, and can be easily decomposed into carbon dioxide, water, and organic waste. Since the polyhydroxyalkanoate resin can be biodegraded not only in soil but also in the ocean, it can be utilized in various applications.

[0039] Since the above polyhydroxyalkanoate resin can be synthesized with various types of monomers, the structure and physical properties of the polyhydroxyalkanoate resin produced may differ depending on the type of monomer.

[0040] The above resin composition for fertilizer coating includes the above polyhydroxyalkanoate resin, thereby allowing the release rate within a certain period functionally required in slow-release fertilizers to be controlled, and after the fertilizer is no longer effective, the coating residue can be easily decomposed not only in soil but also in the ocean.

[0041] The number average molecular weight of the polyhydroxyalkanoate resin may be 100,000 g / mol to 800,000 g / mol, 200,000 g / mol to 800,000 g / mol, 300,000 g / mol to 800,000 g / mol, or 500,000 g / mol to 800,000 g / mol. When the above range is satisfied, the resin composition for fertilizer coating may have a crystallinity range described below, thereby improving the durability of the fertilizer coating layer and the effect of controlling fertilizer release. The number average molecular weight may be measured using gel permeation chromatography (GPC).

[0042] The above polyhydroxyalkanoate resin may include one or more repeating units selected from the group consisting of 2-hydroxybutyrate, lactic acid, glycolic acid, 3-hydroxybutyrate, 3-hydroxypropionate, 3-hydroxyvalerate, 3-hydroxyhexanoate, 3-hydroxyheptanoate, 3-hydroxyoctanoate, 3-hydroxynonanoate, 3-hydroxydecanoate, 3-hydroxydodecanoate, 4-hydroxybutyrate, 4-hydroxyvalerate, 5-hydroxyvalerate, and 6-hydroxyhexanoate.

[0043] The above polyhydroxyalkanoate resin may include 3-hydroxybutyrate repeating units and 4-hydroxybutyrate repeating units. By including the 3-hydroxybutyrate repeating units and 4-hydroxybutyrate repeating units in the polyhydroxyalkanoate resin, the ductility and tensile strength can be controlled, thereby improving the durability of the fertilizer coating layer and controlling the fertilizer release rate. In addition, thermal stability is improved, so that deformation and decomposition caused by heat during the manufacturing process of slow-release fertilizer can be suppressed.

[0044] The above polyhydroxyalkanoate resin may include poly(3-hydroxybutyrate-co-4-hydroxybutyrate) comprising the above 3-hydroxybutyrate repeating unit and 4-hydroxybutyrate repeating unit.

[0045] The above polyhydroxyalkanoate resin may contain the above 4-hydroxybutyrate repeating unit in an amount greater than 0 mol % to 50 mol % or less, greater than 0 mol % to 45 mol % or less, greater than 0 mol % to 40 mol % or less, greater than 0 mol % to 35 mol % or less, or greater than 0 mol % to 30 mol % or less.

[0046] The above polyhydroxyalkanoate resin may contain the above 3-hydroxybutyrate repeating unit in an amount greater than 0 mol % to 99 mol % or less, greater than 0 mol % to 90 mol % or less, greater than 0 mol % to 85 mol % or less, greater than 0 mol % to 80 mol % or less, greater than 0 mol % to 75 mol % or less, or greater than 0 mol % to 70 mol % or less.

[0047] When the above range is satisfied, the crystallinity, mechanical strength, and flexibility of the resin composition for fertilizer coating can be secured, thereby improving the processability of the slow-release fertilizer, controlling the release rate within a certain period required for function, and increasing the rate of biodegradation after the usefulness as a fertilizer is exhausted.

[0048] The above polyhydroxyalkanoate resin may include isomers. The above polyhydroxyalkanoate resin may include structural isomers, enantiomers, and / or geometric isomers.

[0049] The above polyhydroxyalkanoate resin may include an amorphous polyhydroxyalkanoate resin. By including the amorphous polyhydroxyalkanoate resin in the above polyhydroxyalkanoate resin, mechanical properties can be secured. In addition, enzymes and water molecules can penetrate the above polyhydroxyalkanoate resin more easily, so that the rate of biodegradation can be increased after the usefulness as a fertilizer is exhausted.

[0050] The glass transition temperature (Tg) of the above polyhydroxyalkanoate resin may be -50 ℃ to 0 ℃, -50 ℃ to -10 ℃, -40 ℃ to -10 ℃, -30 ℃ to -10 ℃, or -20 ℃ to -10 ℃. The glass transition temperature may be measured using differential scanning calorimetry (DSC).

[0051] The melt flow index of the above polyhydroxyalkanoate resin may be 0.1 g / 10min to 20 g / 10min, 1 g / 10min to 20 g / 10min, 1 g / 10min to 15 g / 10min, or 3 g / 10min to 5 g / 10min. The melt flow index may be measured under conditions of 190°C and 2.16 kg in accordance with ASTM D1238.

[0052] The above fertilizer coating resin composition may include a first biodegradable polyester resin comprising a diol-derived unit, an aliphatic dicarboxylic acid-derived unit, and an aromatic dicarboxylic acid-derived unit.

[0053] The above resin composition for fertilizer coating further includes the first biodegradable polyester resin, thereby improving adhesion between the fertilizer and the resin composition for fertilizer coating, and increasing the rate of biodegradation after the fertilizer is no longer useful.

[0054] The above diol may be an aliphatic diol. The above diol may be a bio-derived diol. The above diols are ethanediol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 2,4-dimethyl-2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 2-methyl-1,8-octanediol, At least one may be selected from the group consisting of 1,9-nonanediol, 1,10-decanediol and 1,12-octadecanediol or derivatives thereof.

[0055] The above diol may be selected from at least one group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol, diethylene glycol, neopentyl glycol, or derivatives thereof.

[0056] The above diol may be selected from at least one group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol, or derivatives thereof.

[0057] The above diol may include 1,4-butanediol or a derivative thereof.

[0058] The above aliphatic dicarboxylic acid may be selected from at least one group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelodic acid, serve acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, or derivatives thereof.

[0059] The above aliphatic dicarboxylic acid may be selected from at least one of the group consisting of adipic acid, succinic acid, sebacic acid, or derivatives thereof.

[0060] The above aliphatic dicarboxylic acid may include adipic acid or a derivative thereof.

[0061] The above aromatic dicarboxylic acid may be selected from at least one group consisting of phthalic acid, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, or derivatives thereof.

[0062] The above aromatic dicarboxylic acid may be selected from at least one of the group consisting of terephthalic acid, dimethyl terephthalate, 2,6-naphthalene dicarboxylic acid, isophthalic acid, or derivatives thereof.

[0063] The above aromatic dicarboxylic acid may include terephthalic acid, dimethyl terephthalate, or derivatives thereof.

[0064] In the first biodegradable polyester resin above, the molar ratio of the total diol residues including the diol and the total dicarboxylic acid residues including the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid may be about 1:0.9 to about 1:1.1, or about 1:0.95 to about 1:1.05.

[0065] In the first biodegradable polyester resin above, the molar ratio of the aromatic dicarboxylic acid residue and the aliphatic dicarboxylic acid residue may be about 3:7 to about 7:3, about 3.3:6.7 to about 6.7:3.3, about 4:6 to about 6:4, or about 4.2:5.8 to about 5:5.

[0066] The first biodegradable polyester resin may contain diol residues derived from 1,4-butanediol in an amount of about 90 mol% or more, about 95 mol% or more, or about 98 mol% or more based on the total diol.

[0067] The first biodegradable polyester resin may contain aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 30 mol% to about 70 mol%, about 35 mol% to about 65 mol%, about 40 mol% to about 60 mol%, or about 43 mol% to about 53 mol% based on the total dicarboxylic acid.

[0068] The first biodegradable polyester resin may contain aliphatic dicarboxylic acid residues derived from adipic acid in an amount of about 30 mol% to about 70 mol%, about 35 mol% to about 65 mol%, about 40 mol% to about 60 mol%, or about 47 mol% to about 57 mol% based on the total dicarboxylic acid.

[0069] The first biodegradable polyester resin may include a first block and a second block. The first biodegradable polyester resin may have a molecular structure in which the first block and the second block are alternately bonded.

[0070] The first block may include the diol residue and the aromatic dicarboxylic acid residue. The first block may be formed by an esterification reaction of the diol and the aromatic dicarboxylic acid. The first block may include only the diol residue and the aromatic dicarboxylic acid residue. The first block may include only the repeating unit formed by the esterification reaction of the diol and the aromatic dicarboxylic acid. The first block may refer to the sum of the repeating units of the diol and the aromatic dicarboxylic acid up to the point of aliphatic dicarboxylic acid bonding.

[0071] The second block may include the diol residue and the aliphatic dicarboxylic acid residue. The second block may be formed by an esterification reaction of the diol and the aliphatic dicarboxylic acid. The second block may include only the diol residue and the aliphatic dicarboxylic acid residue. The second block may include only the repeating unit formed by the esterification reaction of the diol and the aliphatic dicarboxylic acid. The second block may refer to the sum of the repeating units of the diol and the aliphatic dicarboxylic acid up to the point of being bonded to the aromatic dicarboxylic acid.

[0072] In the first biodegradable polyester resin, the ratio (X / Y) of the number of the first blocks (X) and the number of the second blocks (Y) may be about 0.5 to about 1.5, about 0.6 to about 1.4, about 0.7 to about 1.3, about 0.75 to about 1.2, or about 0.8 to about 1. The number of the first blocks may be smaller than the number of the second blocks.

[0073] The number of the first blocks may be about 30 to about 300, about 40 to about 250, about 50 to about 220, about 60 to about 200, about 70 to about 200, or about 75 to about 200.

[0074] The number of the first blocks may vary depending on the content of the aromatic dicarboxylic acid, the molecular weight of the first biodegradable polyester resin, and the degree of substitution described below. That is, as the molar ratio of the aromatic dicarboxylic acid increases, as the molecular weight of the first biodegradable polyester resin increases, and as the degree of substitution described below increases, the number of the first blocks may increase.

[0075] The number of the second blocks may be about 30 to about 300, about 40 to about 250, about 50 to about 220, about 60 to about 200, about 70 to about 200, or about 75 to about 200.

[0076] The number of the second blocks may vary depending on the content of the aliphatic dicarboxylic acid, the molecular weight of the first biodegradable polyester resin, and the degree of substitution described below.

[0077] When the first biodegradable polyester resin comprises the first block and the second block within the above range, the coating layer comprising the polyhydroxyalkanoate resin and the first biodegradable polyester resin can have appropriate mechanical strength while improving biodegradability.

[0078] The above-mentioned first biodegradable polyester resin may include the following bonding structures 1 to 3.

[0079] [Coupling Structure 1]

[0080] - Aromatic dicarboxylic acid - Diol - Aliphatic dicarboxylic acid -

[0081] [Combination Structure 2]

[0082] - Aromatic dicarboxylic acid - Diol - Aromatic dicarboxylic acid -

[0083] [Combination Structure 3]

[0084] - Aliphatic dicarboxylic acid - Diol - Aliphatic dicarboxylic acid -

[0085] The diol included in the above bonding structure 1 is bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. The diol included in the above bonding structure 1 can be directly esterified bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0086] The diol included in the above bonding structure 2 is bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid. The diol included in the above bonding structure 2 can be directly esterified bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid.

[0087] The diol included in the above bonding structure 3 is bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid. The diol included in the above bonding structure 3 can be directly esterified bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0088] The above first biodegradable polyester resin may have an alternating ratio.

[0089] The above replacement ratio is the ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the above diols. That is, the above replacement ratio may be the ratio of the diol included in the bonding structure 1 among the above diols. The above replacement ratio may be a value obtained by dividing the number of moles of the diol included in the bonding structure 1 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0090] The above replacement ratio may be the ratio of the diol in which the heterocyclic acid is bonded between the diols among the total diols.

[0091] The above-mentioned alternation ratio can be calculated using the following formula 1.

[0092] [Formula 1]

[0093]

[0094] In the above formula 1, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0095] In the first biodegradable polyester resin above, the replacement ratio may be about 0.3 to about 0.7, about 0.37 to about 0.59, about 0.4 to about 0.56, or about 0.45 to about 0.53.

[0096] The first biodegradable polyester resin may include a hard segment ratio. The hard segment ratio is the ratio of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid among the diols.

[0097] The hard segment ratio may be the molar ratio of the diol included in the bonding structure 2 among the total diol. The hard segment ratio may be the value obtained by dividing the number of moles of the diol included in the bonding structure 2 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0098] The above hard segment ratio can be expressed by the following formula 2.

[0099] [Equation 2]

[0100]

[0101] In the above formula 2, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0102] The above hard segment ratio may be about 0.15 to about 0.35, about 0.2 to about 0.3, about 0.21 to about 0.29, or about 0.22 to about 0.28.

[0103] The first biodegradable polyester resin composition may include a soft segment.

[0104] The above soft segment ratio is the ratio of the aliphatic dicarboxylic acid and the diol bonded between the aliphatic dicarboxylic acid among the above diols.

[0105] The above soft segment ratio may be the molar ratio of the diol included in the bonding structure 3 among the total diol. The above soft segment ratio may be the value obtained by dividing the number of moles of the diol included in the bonding structure 3 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0106] The above soft segment ratio can be expressed by the following formula 3.

[0107] [Equation 3]

[0108]

[0109] In the above formula 3, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0110] The above soft segment ratio may be about 0.16 to about 0.36, about 0.21 to about 0.31, about 0.22 to about 0.30, or about 0.23 to about 0.29.

[0111] The above soft segment ratio may be larger than the above hard segment ratio.

[0112] The ratio of the hard segment to the soft segment may be about 0.92 to about 0.99. That is, the value obtained by dividing the DM2 by the DM3 may be about 0.92 to about 0.99.

[0113] The above-mentioned alteration ratio, the above-mentioned hard segment ratio, and the above-mentioned soft segment ratio can be measured by nuclear magnetic resonance spectroscopy. The above-mentioned first biodegradable polyester resin composition is dissolved in a solvent such as CDCl3, and at room temperature, by a nuclear magnetic resonance (NMR) device, 1 H-NMR and / or 13 It can be analyzed by C-NMR analysis.

[0114] When the above diol is 1,4-butanediol, the above aromatic dicarboxylic acid is terephthalic acid or dimethyl terephthalate, and the above aliphatic dicarboxylic acid is adipic acid, the analysis of the first biodegradable polyester resin by nuclear magnetic resonance spectroscopy may include the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the ninth peak, the tenth peak, and the eleventh peak.

[0115] When the above diol is 1,4-butanediol, the above aromatic dicarboxylic acid is terephthalic acid or dimethyl terephthalate, and the above aliphatic dicarboxylic acid is adipic acid, the analysis of the first biodegradable polyester resin by nuclear magnetic resonance spectroscopy may include a peak derived from the diol of the bonding structure 1, a peak derived from the diol of the bonding structure 2, and a peak derived from the bonding structure 3 at about 3.5 ppm to about 4.6 ppm.

[0116] In the range of about 3.5 ppm to about 4.6 ppm, the first peak, the second peak, the third peak, and the fourth peak may be defined in order from high ppm to low ppm. Additionally, based on the ppm of the ninth peak, in the range of about -3.4 ppm to about -4.3 ppm, the first peak, the second peak, the third peak, and the fourth peak may be defined in order from high ppm to low ppm.

[0117] The -ppm direction can be the upfield direction or the shielding direction. For example, -3.4 ppm may mean a location of 3.4 ppm in the upfield direction. For example, -3.4 ppm may mean a location of 3.4 ppm in the shielding direction.

[0118] Analysis of the first biodegradable polyester resin by the nuclear magnetic resonance spectroscopy above may include a peak derived from the diol of the bonding structure 1, a peak derived from the diol of the bonding structure 2, and a peak derived from the bonding structure 3, even at about 1.0 ppm to about 2.5 ppm.

[0119] In the range of about 1.0 ppm to about 2.5 ppm, the 10th peak, the 5th peak, the 6th peak, the 7th peak, the 8th peak, and the 11th peak may be defined in order from high ppm to low ppm. Based on the ppm of the 9th peak, in the range of about -6.0 ppm to about -6.7 ppm, the 5th peak, the 6th peak, the 7th peak, the 8th peak, and the 11th peak may be defined in order from high ppm to low ppm.

[0120] The ninth peak may be formed in the range of about 7.5 ppm to about 8.5 ppm. The ninth peak may be derived from the aromatic dicarboxylic acid. The ninth peak may be derived from an aromatic ring contained in the aromatic dicarboxylic acid. The ninth peak may be derived from an aromatic ring contained in the terephthalic acid or dimethyl terephthalate.

[0121] The above 10th peak and the above 11th peak may be derived from the above aliphatic dicarboxylic acid. The above 10th peak and the above 11th peak may be derived from the above adipic acid.

[0122] The first peak may be located at approximately -3.6 ppm to approximately -3.68 ppm based on the ppm of the ninth peak. The second peak may be located at approximately -3.69 ppm to approximately -3.75 ppm based on the ppm of the ninth peak. The third peak may be located at approximately -3.9 ppm to approximately -3.97 ppm based on the ppm of the ninth peak. The fourth peak may be located at approximately -3.98 ppm to approximately -4.1 ppm based on the ppm of the ninth peak. The fifth peak may be located at approximately -6.0 ppm to approximately -6.19 ppm based on the ppm of the ninth peak. The sixth peak may be located at approximately -6.2 ppm to approximately -6.26 ppm based on the ppm of the ninth peak. The 7th peak may be located at approximately -6.27 ppm to approximately -6.34 ppm based on the ppm of the 9th peak. The 8th peak may be located at approximately -6.35 ppm to approximately -6.42 ppm based on the ppm of the 9th peak. The 10th peak may be located at approximately -5.6 ppm to approximately -5.8 ppm based on the ppm of the 9th peak. The 11th peak may be located at approximately -6.421 ppm to approximately -6.5 ppm based on the ppm of the 9th peak. The position based on the ppm of the 9th peak may be the position of each peak when the position of the 9th peak is 0 ppm.

[0123] The areas of the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the tenth peak, and the eleventh peak can be normalized based on the area of ​​the ninth peak. That is, when the area of ​​the ninth peak is 1, the areas of the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the tenth peak, and the eleventh peak can be determined relatively.

[0124] The above alternating ratio can be derived using the following Equation 4 or Equation 5.

[0125] [Equation 4]

[0126]

[0127] In the above formula 4, PA1 is the area of ​​the first peak, PA2 is the area of ​​the second peak, PA3 is the area of ​​the third peak, and PA4 is the area of ​​the fourth peak.

[0128] [Formula 5]

[0129]

[0130] In the above formula 5, PA5 is the area of ​​the fifth peak, PA6 is the area of ​​the sixth peak, PA7 is the area of ​​the seventh peak, and PA8 is the area of ​​the eighth peak.

[0131] The above hard segment ratio can be derived using the following formula 6 or the following formula 7.

[0132] [Equation 6]

[0133]

[0134] In the above formula 6, PA1 is the area of ​​the first peak, PA2 is the area of ​​the second peak, PA3 is the area of ​​the third peak, and PA4 is the area of ​​the fourth peak.

[0135] [Equation 7]

[0136]

[0137] In the above formula 7, PA5 is the area of ​​the fifth peak, PA6 is the area of ​​the sixth peak, PA7 is the area of ​​the seventh peak, and PA8 is the area of ​​the eighth peak.

[0138] The above soft segment ratio can be derived using the following formula 8 or formula 9.

[0139] [Equation 8]

[0140]

[0141] In the above formula 8, PA1 is the area of ​​the first peak, PA2 is the area of ​​the second peak, PA3 is the area of ​​the third peak, and PA4 is the area of ​​the fourth peak.

[0142] [Formula 9]

[0143]

[0144] In the above formula 9, PA5 is the area of ​​the fifth peak, PA6 is the area of ​​the sixth peak, PA7 is the area of ​​the seventh peak, and PA8 is the area of ​​the eighth peak.

[0145] The area of ​​the first peak may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.5, about 0.43 to about 0.52, or about 0.45 to about 0.49. The area of ​​the second peak may be about 0.37 to about 0.57, about 0.41 to about 0.54, about 0.45 to about 0.53, about 0.45 to about 0.55, or about 0.47 to about 0.53. The area of ​​the third peak may be about 0.37 to about 0.57, about 0.41 to about 0.54, about 0.45 to about 0.53, about 0.45 to about 0.55, or about 0.47 to about 0.53. The area of ​​the fourth peak may be about 0.4 to about 0.7, about 0.45 to about 0.65, about 0.48 to about 0.6, about 0.48 to about 0.60, or about 0.50 to about 0.58. The area of ​​the fifth peak may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.53, about 0.43 to about 0.52, or about 0.45 to about 0.49. The area of ​​the sixth peak may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.5, about 0.45 to about 0.55, or about 0.47 to about 0.53. The area of ​​the seventh peak may be about 0.41 to about 0.71, about 0.45 to about 0.65, about 0.48 to about 0.6, about 0.45 to about 0.55, or about 0.47 to about 0.53. The area of ​​the eighth peak may be about 0.4 to about 0.7, about 0.45 to about 0.65, about 0.48 to about 0.6, or about 0.50 to about 0.58. The area of ​​the tenth peak may be about 0.7 to about 2.5, about 0.75 to about 2, about 0.8 to about 1.5, about 1.0 to about 1.15, or about 1.02 to about 1.13. The area of ​​the eleventh peak may be about 0.It may be 7 to about 3.5, about 0.7 to about 3, about 0.8 to about 2.5, about 1.0 to about 1.15, or about 1.02 to about 1.13.

[0146] The sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may be about 1.49 to about 2.44, about 1.81 to about 2.16, about 1.9 to about 2.2, or about 1.95 to about 2.1. Here, the sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may represent the sum of the total number of ester bonds based on the number of terephthalic acids.

[0147] The sum of the areas of the second peak and the third peak may be about 0.95 to about 1.10, or about 0.98 to about 1.07. Here, the sum of the areas of the first peak and the third peak may represent the degree of extension of the molecular bonds of the first biodegradable polyester resin.

[0148] The ratio of the area of ​​the fourth peak to the area of ​​the first peak (area of ​​the fourth peak / area of ​​the first peak) may be about 1.1 to about 1.3, about 0.67 to about 2, about 0.96 to about 1.40, or about 1.15 to about 1.25. The ratio of the area of ​​the fourth peak to the area of ​​the first peak may refer to the ratio of the soft segment to the hard segment within the molecular structure of the first biodegradable polyester resin. That is, the higher the ratio of the area of ​​the fourth peak to the area of ​​the first peak, the more the first biodegradable polyester resin may have improved adhesive properties.

[0149] The ratio of the area of ​​the fourth peak to the area of ​​the third peak (area of ​​the fourth peak / area of ​​the third peak) may be about 0.7 to about 1.89, about 0.91 to about 1.33, about 1.0 to about 1.2, or about 1.01 to about 1.1.

[0150] The ratio of the area of ​​the first peak to the area of ​​the second peak (area of ​​the first peak / area of ​​the second peak) may be about 0.61 to about 1.62, about 0.81 to about 1.11, about 0.85 to about 0.95, or about 0.86 to about 0.94.

[0151] The ratio of the area of ​​the fifth peak to the area of ​​the first peak (area of ​​the fifth peak / area of ​​the first peak) may be about 0.61 to about 1.71, about 0.96 to about 1.40, about 0.8 to about 1.2, or about 0.9 to about 1.1. The ratio of the area of ​​the sixth peak to the area of ​​the second peak (area of ​​the sixth peak / area of ​​the second peak) may be about 0.58 to about 1.71, about 0.86 to about 1.16, about 0.8 to about 1.2, or about 0.9 to about 1.1. The ratio of the area of ​​the seventh peak to the area of ​​the third peak (area of ​​the seventh peak / area of ​​the third peak) may be about 0.72 to about 1.92, about 0.91 to about 1.33, about 0.8 to about 1.2, or about 0.9 to about 1.1. The ratio of the area of ​​the eighth peak to the area of ​​the fourth peak (area of ​​the eighth peak / area of ​​the fourth peak) may be about 0.59 to about 1.75, about 0.80 to about 1.2, or about 0.9 to about 1.1.

[0152] The number average molecular weight of the first biodegradable polyester resin may be 20,000 g / mol to 100,000 g / mol, 20,000 g / mol to 80,000 g / mol, 20,000 g / mol to 70,000 g / mol, or 30,000 g / mol to 62,000 g / mol. When satisfying the above ranges, the resin may have a degree of crystallization that allows for excellent adhesion to fertilizers and improved coating processability. The number average molecular weight may be measured using gel permeation chromatography (GPC).

[0153] The degree of crystallization of the first biodegradable polyester resin may be 10% to 30%, less than 10% to 30%, less than 12% to 30%, 12% to 28%, or 15% to 25%. When the above range is satisfied, the adhesion to fertilizer is excellent, and fusion between resin compositions for fertilizer coating can be suppressed.

[0154] The above degree of crystallinity is the melting enthalpy (ΔH) measured using Differential Scanning Calorimetry (DSC). m ) enthalpy of melting in 100% crystal (ΔH c It can be calculated as a percentage of the value divided by ).

[0155] Specifically, it can be calculated according to the following formula.

[0156] [Calculation Formula]

[0157] Degree of Crystallinity (%) = [Energy required to melt 1g of No. 1 biodegradable polyester resin (Crystal melting energy (J / g) - Crystal formation energy (J / g)) / Energy required to melt 1g of No. 1 biodegradable polyester resin with 100% degree of crystallinity (J / g)] × 100

[0158] The resin composition for fertilizer coating above may include a second biodegradable polyester resin having a degree of crystallization of 27% to 60% as measured by the differential scanning calorimeter above.

[0159] The second biodegradable polyester resin can complement the chemical and mechanical properties of the polyhydroxyalkanoate resin and the first biodegradable polyester resin.

[0160] The above fertilizer coating resin composition further includes the second biodegradable polyester resin, thereby maintaining adhesion between the fertilizer and the fertilizer coating resin composition while suppressing adhesion between the fertilizer coating resin compositions, ensuring fertilizer coating processability and suppressing adhesion between slow-release fertilizers after fertilizer coating.

[0161] The number average molecular weight of the second biodegradable polyester resin may be 50,000 g / mol to 150,000 g / mol, 50,000 g / mol to 140,000 g / mol, 50,000 g / mol to 100,000 g / mol, or 50,000 g / mol to 80,000 g / mol.

[0162] The degree of crystallization of the second biodegradable polyester resin may be 27% to 60%, 30% to 60%, 35% to 60%, 40% to 60%, 45% to 60%, or 45% to 55%.

[0163] If the above range is satisfied, the processability of the fertilizer coating can be ensured, and the occurrence of adhesion between slow-release fertilizers after fertilizer coating can be suppressed.

[0164] The second biodegradable polyester resin may include at least one of polybutylene azelate terephthalate (PBAzT), polybutylene sebacate terephthalate (PBSeT), polyhydroxyalkanoate (PHA), and polybutylene succinate (PBS).

[0165] The second biodegradable polyester resin may include polybutylene succinate (PBS).

[0166] The above PBS may be a biodegradable resin synthesized by condensation polymerization through an esterification reaction between 1,4-butanediol (1,4-BDO) and succinic acid, and an ester exchange reaction of the oligomer generated thereby.

[0167] The above PBS is environmentally friendly as it can be naturally decomposed by microorganisms, etc., and can have improved mechanical properties such as fracture strength, tensile strength, elongation, and hardness.

[0168] The content of the polyhydroxyalkanoate resin may be 5 to 30 parts by weight, 10 to 30 parts by weight, 12 to 30 parts by weight, or 12 to 25 parts by weight based on 100 parts by weight of the total of the first biodegradable polyester resin and the second biodegradable polyester resin. When the above range is satisfied, the adhesion to fertilizer is excellent, the release rate of fertilizer can be controlled, and the coating processability can be improved.

[0169] The weight ratio of the first biodegradable polyester resin to the second biodegradable polyester resin may be 2:8 to 8:2, 3:7 to 7:3, 4:6 to 7:3, or 4:6 to 6:4. When the above range is satisfied, the average degree of crystallization of the resin composition for fertilizer coating is controlled within a certain range, thereby providing excellent adhesion to the fertilizer, enabling control of the fertilizer release rate, and improving the coating processability.

[0170] The resin composition for fertilizer coating above may include a flow promoter comprising a silicone-based compound.

[0171] The above-mentioned flow promoter can suppress the adhesion between resin compositions for fertilizer coating. Additionally, a uniform coating layer can be formed on the surface of the fertilizer. Furthermore, after fertilizer coating, the occurrence of adhesion between slow-release fertilizers can be suppressed. As a result, the processability of the fertilizer coating can be ensured.

[0172] The content of the above flow promoter may be 0.01% to 10% by weight, 0.1% to 10% by weight, 0.1% to 5% by weight, or 0.1% to 3% by weight based on the total weight of the resin composition for fertilizer coating. When the above range is satisfied, the tackiness between the resin compositions for fertilizer coating can be suppressed, and the processability of the fertilizer coating can be ensured.

[0173] The above silicon-based compound may include a compound represented by the following chemical formula 1.

[0174] [Chemical Formula 1]

[0175]

[0176] In the above formula 1, R1 and R2 are each independently hydrogen; a hydroxyl group; an alkyl group having 1 to 10 carbon atoms; a heteroalkyl group having 1 to 10 carbon atoms comprising at least one heteroatom selected from sulfur, oxygen, and nitrogen; an alkyl group having 1 to 10 carbon atoms comprising a hydroxyl group at the terminal; or a heteroalkyl group having 1 to 10 carbon atoms comprising a hydroxyl group at the terminal and at least one heteroatom selected from sulfur, oxygen, and nitrogen, and R3 to R8 are each independently an alkyl group having 1 to 5 carbon atoms, and n is an integer from 0 to 50.

[0177] The above R1 and R2 may be an alkyl group having 1 to 10 carbon atoms having a hydroxyl group at the terminal; or a heteroalkyl group having 1 to 10 carbon atoms having a hydroxyl group at the terminal and comprising at least one heteroatom selected from sulfur, oxygen, and nitrogen.

[0178] The above R3 to R8 may be methyl groups.

[0179] The above n may be an integer from 1 to 50, 1 to 30, 1 to 10, or 1 to 5.

[0180] The above silicon-based compound may further include a compound represented by the following chemical formula 2.

[0181] [Chemical Formula 2]

[0182]

[0183] In the above chemical formula 2, R9 and R 10 Each is independently an alkyl group having 1 to 5 carbon atoms, and n is an integer from 3 to 8.

[0184] The above R9 to R 10 It can be a methyl group.

[0185] The above n may be an integer from 3 to 6.

[0186] When the above silicone-based compound includes a specific structure represented by Chemical Formula 1 and / or Chemical Formula 2, it can be uniformly dispersed in the resin composition for fertilizer coating. Additionally, due to the migration effect, a membrane can be formed on the surface of the resin composition for fertilizer coating, thereby reducing the phenomenon of adhesion between the resin compositions for fertilizer coating. Furthermore, after fertilizer coating, adhesion between slow-release fertilizers can be suppressed, thereby ensuring the processability of the fertilizer coating.

[0187] The epoxy equivalent weight of the above silicon-based compound may be 3,000 g / mol to 10,000 g / mol, 4,000 g / mol to 10,000 g / mol, 5,000 g / mol to 10,000 g / mol, or 4,500 g / mol to 5,700 g / mol.

[0188] The above silicon-based compound may have an average particle size according to the CTM1151 measurement method of 0.1 μm to 5 μm, 0.1 μm to 4 μm, 0.1 μm to 3 μm, 0.5 μm to 3 μm, or 1 μm to 3 μm.

[0189] The above silicon-based compound may have a bulk density according to the CTM0025 measurement method of 0.01 g / mL to 1 g / mL, 0.1 g / mL to 1 g / mL, 0.1 g / mL to 0.5 g / mL, or 0.1 g / mL to 0.3 g / mL.

[0190] The above silicon-based compound may have a volatile content according to the CTM0208 measurement method of 1.5 wt% or less, 1.2 wt% or less, 1 wt% or less, or greater than 0 wt% and less than or equal to 1 wt%. Specifically, the volatile content may be measured as the amount of 2 g of the silicon compound volatilized over 2 hours at a temperature of about 105 ℃.

[0191] The content of the above silicone-based compound may be 90% to 99.9% by weight, 90% to 99% by weight, 90% to 98% by weight, or 90% to 97% by weight, 91% to 97% by weight, 92% to 97% by weight, 93% to 97% by weight, or 94% to 97% by weight, based on the total weight of the flow promoter. When the above range is satisfied, heat resistance and dispersibility may be improved.

[0192] The above flow promoter may further include silica.

[0193] The above silica can improve the compatibility between the resin composition for fertilizer coating and the silicon-based compound, and can further improve the efficiency of the lubricating effect on the surface of the resin composition for fertilizer coating.

[0194] The resin composition for fertilizer coating above may include an amide-based compound.

[0195] The above amide-based compound may include at least one of the compounds represented by the following chemical formulas 3 to 5. When it includes a specific structure represented by the following chemical formulas 4 to 5, it can be uniformly dispersed in the resin composition for fertilizer coating. In addition, due to the migration effect, a membrane may be formed on the surface of the resin composition for fertilizer coating, thereby reducing the phenomenon of adhesion between the resin compositions for fertilizer coating. Furthermore, after fertilizer coating, the occurrence of adhesion between slow-release fertilizers can be suppressed, thereby ensuring the processability of the fertilizer coating.

[0196] [Chemical Formula 3]

[0197]

[0198] [Chemical Formula 4]

[0199]

[0200] [Chemical Formula 5]

[0201]

[0202] In the above chemical formulas 3 to 5, R 11 to R 15 Each is independently a straight-chain or branched alkyl group having 2 to 25 carbon atoms, and R 16 It is an alkylene group having 1 to 5 carbon atoms.

[0203] The compound represented by the above chemical formula 3 may be stearamide.

[0204] The compound represented by the above chemical formula 4 may be oleamide.

[0205] The compound represented by the above chemical formula 5 may be N,N-ethylenebis(stearamide) (N,N-Ethylenebis(stearamide).

[0206] The resin composition for fertilizer coating above may include an adhesion enhancer comprising a silane coupling agent.

[0207] The adhesion between the fertilizer and the coating layer can be improved by the above-mentioned adhesion enhancer. In addition, the release rate within a certain period functionally required in slow-release fertilizers can be controlled.

[0208] The above silane coupling agent may include a compound represented by the following chemical formula 6. When it includes a specific structure represented by the chemical formula 6, it can be uniformly dispersed in the resin composition for fertilizer coating. In addition, the adhesion between the fertilizer substrate and the coating layer is improved, allowing the coating layer to be uniformly formed on the fertilizer. Furthermore, cracking of the coating layer due to changes over time can be suppressed, thereby controlling the release rate within a certain period functionally required for slow-release fertilizers.

[0209] [Chemical Formula 6]

[0210]

[0211] In the above chemical formula 6, the R 17 and R 18 Each is independently hydrogen or an alkyl group having 1 to 5 carbon atoms, and R 19 is an alkylene group having 1 to 5 carbon atoms, and R 20 is an alkyl group, cycloalkyl group, or aryl group containing an epoxy group, and n is an integer from 0 to 3.

[0212] The above R 17 It can be a methyl group or an ethyl group.

[0213] The above n may be an integer from 1 to 3.

[0214] Preferably, the above R 17... is a methyl group, and n can be an integer of 3. In this case, the reactivity between the fertilizer that is the substrate and the resin composition for fertilizer coating can be improved, thereby improving the adhesion between the fertilizer and the coating layer and allowing the coating layer to be formed more uniformly on the fertilizer.

[0215] The content of the above adhesion enhancer may be 0.1% to 10% by weight, 0.1% to 5% by weight, 0.1% to 3% by weight, or 0.1% to 2% by weight based on the total weight of the resin composition for fertilizer coating. When the above range is satisfied, the adhesion between the fertilizer and the coating layer is improved, so that the coating layer can be uniformly formed on the fertilizer.

[0216] The resin composition for fertilizer coating may include a crystallization promoter. The crystallization promoter may be included in an amount of 100 ppm to 50,000 ppm, 100 ppm to 40,000 ppm, 100 ppm to 30,000 ppm, 100 ppm to 10,000 ppm, or 100 ppm to 6,000 ppm based on the total weight of the resin composition for fertilizer coating.

[0217] The crystallization promoter may include at least one of an organic nucleating agent and an inorganic nucleating agent. The organic nucleating agent may refer to a nucleating agent composed of an organic compound.

[0218] The above organic nucleating agent may include nanocellulose.

[0219] The content of the nanocellulose may be 10 ppm to 500 ppm, 50 ppm to 500 ppm, 50 ppm to 300 ppm, or 50 ppm to 200 ppm based on the total weight of the resin composition for fertilizer coating. When the above range is satisfied, the crystallization rate may be improved, and adhesion between the compositions may be suppressed during the coating process.

[0220] The above nanocellulose may have an average length of 10 nm to 300 nm, 10 nm to 200 nm, 20 nm to 200 nm, or 30 nm to 200 nm.

[0221] The above nanocellulose may be bead mill pretreated or ultrasonically pretreated. The above nanocellulose may be subjected to both bead mill pretreatment and ultrasonically pretreatment. It is preferable to perform ultrasonically pretreatment on the nanocellulose after bead mill pretreatment in order to prevent re-aggregation and improve dispersibility.

[0222] The above bead mill pretreatment can be performed using a wet milling device, either a vertical mill or a horizontal mill. The horizontal mill is preferred in that it allows for a larger amount of beads to be filled inside the chamber, reduces uneven wear of the machine and beads, and makes maintenance easier.

[0223] The above bead mill pretreatment can be performed using one or more beads selected from the group consisting of zirconium, zircon, zirconia, quartz, and aluminum oxide.

[0224] The above bead mill pretreatment can be performed using beads having a diameter of about 0.3 mm to about 1 mm. The diameter of the beads may be about 0.3 mm to about 0.9 mm, about 0.4 mm to about 0.8 mm, about 0.45 mm to about 0.7 mm, or about 0.45 mm to about 0.6 mm. If the above range is satisfied, the dispersibility of the nanocellulose may be improved.

[0225] The above ultrasonic pretreatment refers to a method of physically closing or crushing nanoparticles with waves generated by emitting 20 kHz ultrasonic waves into a solution.

[0226] The above ultrasonic pretreatment may be performed for a time of less than 30 minutes at an output of 30,000 J / s or less. The above ultrasonic pretreatment may be performed for a time of 25 minutes or less, 20 minutes or less, or 18 minutes or less at an output of 25,000 J / s or less or 22,000 J / s or less. When the above range is satisfied, the effect of the ultrasonic pretreatment, that is, the improvement of dispersibility, can be maximized.

[0227] The above-mentioned inorganic nucleating agent may refer to a nucleating agent composed of an inorganic compound.

[0228] The resin composition for fertilizer coating above may contain the inorganic nucleating agent in an amount of 100 ppm to 10,000 ppm, 100 ppm to 8,000 ppm, 300 ppm to 8,000 ppm, 500 ppm to 8,000 ppm, or 500 ppm to 6,000 ppm. When the above ranges are satisfied, the crystallization rate may be improved, and adhesion between the compositions may be suppressed during the coating process.

[0229] The above-mentioned inorganic nucleating agent may include one or more selected from the group consisting of titanium dioxide, talc, kaolinite, montmorillonite, mica, clay, zeolite, silica, graphite, carbon black, mica, barium sulfate, calcium silicate, calcium carbonate, calcium sulfide, calcium titanate, zinc oxide, aluminum oxide, magnesium oxide, neodymium oxide, and boron nitride.

[0230] The above-mentioned inorganic nucleating agent may include titanium dioxide containing an anatase phase. The titanium dioxide containing the anatase phase exhibits high photoactivity, which can further enhance biodegradability.

[0231] Average diameter (D) of the above-mentioned inorganic nucleating agent 50) may be 0.1 μm to 0.5 μm, 0.1 μm to 0.4 μm, 0.15 μm to 0.4 μm, 0.15 μm to 0.3 μm, or 0.15 μm to 0.25 μm. If the above range is satisfied, the mechanical strength of the resin composition for fertilizer coating may be improved.

[0232] The resin composition for fertilizer coating may further include a heat stabilizer. The heat stabilizer may be selected from at least one of the group consisting of amine-based high-temperature heat stabilizers such as tetraethylenepentamine, triethylphosphonoacetate, phosphoric acid, phosphorous acid, polyphosphric acid, trimethyl phosphate (TMP), triethyl phosphate, trimethyl phosphine, and triphenyl phosphine.

[0233] The content of the heat stabilizer may be 10 ppm to 3,000 ppm, 20 ppm to 2,000 ppm, 20 ppm to 1,500 ppm, or 20 ppm to 1,000 ppm relative to the total weight of the resin composition for fertilizer coating. When the above range is satisfied, the deterioration of the resin composition for fertilizer coating due to temperature influence during the reaction process can be suppressed.

[0234] The resin composition for fertilizer coating above may further include a branching agent comprising at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid.

[0235] The branching agent may react with the diol, the aliphatic dicarboxylic acid, and / or the aromatic dicarboxylic acid in the first biodegradable polyester resin. The branching agent may be included as part of the molecular structure of the first biodegradable polyester resin.

[0236] The above trivalent or higher alcohols may be selected from at least one of the group consisting of glycerol, pentaerythritol, and trimethylolpropane.

[0237] The above trivalent or higher carboxylic acids are methane tricarboxylic acid, ethane tricarboxylic acid, citric acid, benzene-1,3,5-tricarboxylic acid, 5-sulfo-1,2,4-benzenetricarboxylic acid, ethane-1,1,2,2-tetracarboxylic acid, propane-1,1,2,3-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, At least one may be selected from the group consisting of cyclopentane-1,2,3,4-tetracarboxylic acid and benzene-1,2,4,5-tetracarboxylic acid.

[0238] The above branching agent may include glycerol.

[0239] The content of the branching agent may be 500 ppm to 3,000 ppm, 700 ppm to 3,000 ppm, 700 ppm to 2,500 ppm, or 1,000 ppm to 2,000 ppm relative to the total weight of the resin composition for fertilizer coating. When the above range is satisfied, the coating layer may have appropriate biodegradability and mechanical properties may be improved.

[0240] The silicon content included in the resin composition for fertilizer coating above may be 1 ppm to 5,000 ppm, 10 ppm to 5,000 ppm, 100 ppm to 5,000 ppm, 100 ppm to 3,000 ppm, 100 ppm to 2,000 ppm, 100 ppm to 1,000 ppm, or 100 ppm to 500 ppm. When the above range is satisfied, the tackiness between the resin compositions for fertilizer coating can be suppressed, and the processability of the fertilizer coating can be ensured.

[0241] The silicon content included in the resin composition for fertilizer coating can be measured by inductively coupled plasma emission analysis (ICP-OES).

[0242] The above resin composition for fertilizer coating can detect a cyclic siloxane detection peak by pyrolysis gas chromatography / mass spectrometry (py-GC / MS) at 600°C and 10 minutes.

[0243] The above cyclic siloxane may be detected with a retention time in the range of 2.5 to 3.5 minutes and may include one or more peaks at a mass-to-charge ratio (m / z) selected from the group consisting of 73, 207, 267, 281, 341, 355, and 429.

[0244] The resin composition for fertilizer coating above may have a degree of crystallization of 15% to 40% as measured by Differential Scanning Calorimetry (DSC).

[0245] The degree of crystallization is determined by placing about 5 mg to 10 mg of the sample to be analyzed into a differential scanning calorimeter pan, and then melting the sample at about 200 °C to 220 °C for about 5 minutes under an inert gas atmosphere to remove the thermal history. Afterward, the sample is cooled rapidly to a non-crystalline state, and then heated again at a heating rate of about 10 °C / min, and the degree of crystallization is calculated by the following equation based on the peak that appears.

[0246] [ceremony]

[0247] Degree of Crystallinity (%) = [(Enthalpy of melting of sample (J / g) - Enthalpy of cooling crystallization of sample (J / g)) / (Enthalpy of melting of 100% crystalline phase of sample (J / g))] X 100

[0248] Preferably, the degree of crystallization may be 15% to 40%, 18% to 40%, 20% to 40%, 25% to 40%, 30% to 40%, or 33% to 38%. When the above range is satisfied, the adhesion between resin compositions for fertilizer coating can be suppressed, thereby ensuring fertilizer coating processability and suppressing the occurrence of adhesion between slow-release fertilizers after fertilizer coating.

[0249] The resin composition for fertilizer coating above may have a degree of crystallization calculated according to Formula 1 below, and the degree of crystallization according to Formula 1 below may be 15% to 40%.

[0250] [Equation 1]

[0251] Degree of crystallization = (A × A p ) + (B × B p ) + (C × C p )

[0252] In the above formula 1, A is the degree of crystallization of the polyhydroxyalkanoate resin, B is the degree of crystallization of the first biodegradable polyester resin, and C is the degree of crystallization of the second biodegradable polyester resin.

[0253] In addition, the above A p is the weight ratio of the polyhydroxyalkanoate resin based on the total weight of the polyhydroxyalkanoate resin, the first biodegradable polyester resin, and the second biodegradable polyester resin. B pis the weight ratio of the first biodegradable polyester resin based on the total weight of the polyhydroxyalkanoate resin, the first biodegradable polyester resin, and the second biodegradable polyester resin. C p is the weight ratio of the second biodegradable polyester resin based on the total weight of the polyhydroxyalkanoate resin, the first biodegradable polyester resin, and the second biodegradable polyester resin. p , B p , and C p is a decimal number.

[0254] The above decimals represent percentages expressed in decimal form, for example, 50% is expressed as 0.5.

[0255] In the above formula 1, A may be 0% to 50%, 0% to 45%, 0% to 40%, or 0% to 35%.

[0256] In the above formula 1, B may be 10% to 30%, less than 10% to 30%, less than 12% to 30%, 12% to 28%, or 15% to 25%.

[0257] In the above formula 1, C may be 27% to 60%, 30% to 60%, 35% to 60%, 40% to 60%, 45% to 60%, or 45% to 55%.

[0258] For example, when the above fertilizer coating resin composition is mixed with 10% by weight of the polyhydroxyalkanoate resin having a crystallinity of 0%, 45% by weight of the first biodegradable polyester resin having a crystallinity of 10%, and 45% by weight of the second biodegradable polyester resin having a crystallinity of 50%, the crystallinity according to Formula 1 {(0% × 0.1) + (10% × 0.45) + (50% × 0.45)} can be calculated as 32.95%.

[0259] The degree of crystallinity of the resin composition for fertilizer coating can be controlled according to the molar ratio of 3-hydroxybutyrate repeating units contained in the polyhydroxyalkanoate resin.

[0260] The degree of crystallinity of the resin composition for fertilizer coating can be controlled according to the molar ratio of 4-hydroxybutyrate repeating units contained in the polyhydroxyalkanoate resin.

[0261] The degree of crystallization of the resin composition for fertilizer coating can be controlled according to the degree of crystallization of the polyhydroxyalkanoate resin, the degree of crystallization of the first biodegradable polyester resin, and the degree of crystallization of the second biodegradable polyester resin.

[0262] The degree of crystallization of the resin composition for fertilizer coating can be controlled according to the weight ratio of the polyhydroxyalkanoate resin, the first biodegradable polyester resin, and the second biodegradable polyester resin.

[0263] The above resin composition for fertilizer coating may have a viscosity range of 50 cPs to 150 cPs, 50 cPs to 140 cPs, 50 cPs to 135 cPs, or 50 cPs to 130 cPs according to the following measurement conditions. When the above range is satisfied, the adhesion to the fertilizer is excellent, and the adhesion between resin compositions for fertilizer coating can be suppressed.

[0264] [Measurement Conditions]

[0265] 1) Viscosity meter: RVDV-II (BROOKFIELD), spindle 62

[0266] 2) RPM: 30 RPM(10 sec)

[0267] 3) Measured temperature: 25 ℃

[0268] 4) Concentration: 5 wt% (CHCl3 solvent)

[0269]

[0270] The fertilizer coating solution according to the present invention may include the aforementioned fertilizer coating resin composition and a solvent.

[0271] The above solvent is a Hansen fractionation dispersion parameter (f d ) 0.5 to 0.9, Hansen fractionation polarity parameter (f p ) 0 to 0.3, and Hansen fractionation hydrogen bonding parameter (f h It can be 0.1 to 0.4.

[0272] The above Hansen fractionation dispersion parameter (f d ), Hansen fractionation polarity parameter (f p ), and Hansen fractionation hydrogen bonding parameter (f h ) may be a method for defining the solubility parameter of a solvent that can be calculated from the Hansen solubility parameter. The above Hansen fractionation dispersion parameter (f d ), Hansen fractionation polarity parameter (f p ), and Hansen fractionation hydrogen bonding parameter (f h ) may be for standardizing three Hansen solubility parameters. The above Hansen fractionation dispersion parameter (f d ), Hansen fractionation polarity parameter (f p ), and Hansen fractionation hydrogen bonding parameter (f h The sum of ) is 1.

[0273] The above Hansen solubility parameter is a parameter that can predict whether one substance will dissolve in another substance to form a homogeneous solution. The above Hansen solubility parameter can be used to identify substances that are incompatible with each other or have limited solubility. The above Hansen solubility parameter is a dispersion parameter (δ d ), polarity parameter (δ p ), and hydrogen bonding parameter (δ h It may include ).

[0274] The above Hansen solubility parameter can be converted into a fractionated value in the following mathematical formulas 1 to 3, and the fractionated value is the Hansen fractionated dispersion parameter (f d ), Hansen fractionation polarity parameter (f p ), and Hansen fractionation hydrogen bonding parameter (f h It may include ).

[0275] [Mathematical Formula 1]

[0276] Hansen fractionation variance parameter (f d ) = δ d / (δ d + δ p + δ h )

[0277] [Mathematical Formula 2]

[0278] Hansen fractionation polarity parameter (f p ) = δ p / (δ d + δ p + δ h )

[0279] [Mathematical Formula 3]

[0280] Hansen fractionation hydrogen bonding parameter (f h ) = δ h / (δ d + δ p + δ h )

[0281] The above Hansen fractionation dispersion parameter (f d ) It may be 0.5 to 0.9, 0.6 to 0.9, 0.7 to 0.9, or 0.8 to 0.9.

[0282] The above Hansen fractionation polarity parameter (f p ) It may be 0 to 0.3, 0 to 0.2, 0 to 0.1, or 0 to 0.05.

[0283] The above Hansen fractionation hydrogen bonding parameter (f h ) It may be 0.1 to 0.4, 0.1 to 0.3, 0.1 to 0.2, or 0.1 to 0.15.

[0284] If the above range is satisfied, the mixing ability with the resin composition for fertilizer coating is improved, and the processability of the fertilizer coating can be ensured.

[0285] The content of the resin composition for fertilizer coating may be 1% to 20% by weight, 5% to 20% by weight, 7% to 20% by weight, 8% to 20% by weight, 10% to 20% by weight, 12% to 20% by weight, or 12% to 18% by weight based on the total weight of the solution for fertilizer coating.

[0286] If the above range is satisfied, it can have appropriate mixing properties with the resin composition for fertilizer coating, and the amount of residual solvent can be minimized, allowing the solvent to be recycled more efficiently.

[0287]

[0288] The slow-release fertilizer according to the present invention comprises a fertilizer and a coating layer formed on the fertilizer, wherein the coating layer comprises a polyhydroxyalkanoate resin and the degree of crystallization of the coating layer measured by differential scanning calorimetry (DSC) may be 15% to 40%.

[0289] The above coating layer may be derived from the resin composition for fertilizer coating described above.

[0290] The above coating layer may be derived from the aforementioned fertilizer coating solution.

[0291] The above coating layer may be formed by removing the solvent from the aforementioned fertilizer coating solution.

[0292] There are no specific restrictions on the types of fertilizers mentioned above, and the components of the fertilizer may include nitrogen-containing organic compounds such as urea, ammonium salts such as ammonium nitrate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium sulfate, and ammonium chloride, and iron salts such as ferrous nitrate, ferric nitrate, ferrous phosphate, ferrous phosphate, ferrous sulfate, ferrous sulfate, ferrous chloride, and ferric chloride.

[0293] By coating the fertilizer with the coating layer, the release rate of the fertilizer within a certain period functionally required in the slow-release fertilizer can be controlled. In addition, after the slow-release fertilizer has exhausted its utility as a fertilizer, the residue of the coating layer can be easily decomposed in the soil and ocean.

[0294] The thickness of the coating layer may be 10 µm to 300 µm, 10 µm to 250 µm, 10 µm to 200 µm, 10 µm to 150 µm, 10 µm to 100 µm, 20 µm to 100 µm, 20 µm to 90 µm, or 20 µm to 80 µm. When the above range is satisfied, the release rate within a certain period functionally required in slow-release fertilizers can be controlled.

[0295] The coating layer may comprise a first biodegradable polyester resin comprising a diol-derived unit, an aliphatic dicarboxylic acid-derived unit, and an aromatic dicarboxylic acid-derived unit, and a second biodegradable polyester resin having a degree of crystallinity of 27% to 60% as measured by the differential scanning calorimeter.

[0296] The first biodegradable polyester resin and the second biodegradable polyester resin may be the same as the first biodegradable polyester resin and the second biodegradable polyester resin described above.

[0297] The volume of the coating layer may be 7 volume % to 33 volume %, 9 volume % to 33 volume %, 9 volume % to 30 volume %, or 10 volume % to 25 volume % relative to the volume of the fertilizer.

[0298] The thickness variation of the above coating layer can satisfy the following calculation formula.

[0299] [Calculation Formula]

[0300] (T max - T min ) / T avg < 0.5

[0301] In the above calculation formula, the above T max is the maximum thickness of the coating layer measured by a Scanning Electron Microscope (SEM), and T min is the minimum thickness of the coating layer, and T avg is the average thickness of the coating layer.

[0302] The above (T max - T min ) / T avg It may be 0.47 or less, 0.45 or less, 0.4 or less, 0.35 or less, or 0.3 or less.

[0303] If the above range is satisfied, the release rate within a certain period functionally required in slow-release fertilizers can be controlled.

[0304] The above coating layer may include a flow promoter comprising a silicon-based compound.

[0305] The coating layer may include an amide-based compound. The flow promoter, the silicon-based compound, and the amide-based compound may be the same as the flow promoter, silicon-based compound, and amide-based compound described above.

[0306] The coating layer may include functional groups derived from a silane coupling agent. The adhesion between the fertilizer and the coating layer may be improved by the silane coupling agent. Additionally, the release rate within a certain period functionally required in slow-release fertilizers can be controlled.

[0307] The above silane coupling agent may be the same as the silane coupling agent described above.

[0308] The content of the coating layer may be 5% to 25% by weight, 10% to 25% by weight, 15% to 25% by weight, 15% to 23% by weight, 16% to 23% by weight, or 17% to 23% by weight based on the total weight of the slow-release fertilizer. When the above range is satisfied, after the slow-release fertilizer has lost its utility as a fertilizer, the residue of the coating layer can be easily decomposed in the soil and ocean, and the release rate within a certain period functionally required for the slow-release fertilizer can be controlled.

[0309] The method for manufacturing the slow-release fertilizer described above may include the steps of: preparing a resin composition for fertilizer coating comprising a polyhydroxyalkanoate resin, a first biodegradable polyester resin, and a second biodegradable polyester resin; preparing a solution for fertilizer coating by mixing the resin composition for fertilizer coating and a solvent; and forming a coating layer on the fertilizer by flowing the fertilizer and the solution for fertilizer coating.

[0310] The above manufacturing method may include the step of preparing a resin composition for fertilizer coating. The polyhydroxyalkanoate resin, the first biodegradable polyester resin, and the second biodegradable polyester resin may be the same as the polyhydroxyalkanoate resin, the first biodegradable polyester resin, and the second biodegradable polyester resin described above.

[0311] In the above step, the resin composition for fertilizer coating may include a flow promoter. The flow promoter may be the same as the flow promoter described above.

[0312] The above flow promoter may include an amide-based compound. The above resin composition for fertilizer coating may include an adhesion enhancer comprising a silane coupling agent.

[0313] The above amide-based compound and the above adhesion enhancer may be the same as the above amide-based compound and the above adhesion enhancer.

[0314] The above manufacturing method may include the step of preparing a fertilizer coating solution by mixing the fertilizer coating resin composition and a solvent.

[0315] The above fertilizer coating solution may be the same as the fertilizer coating solution described above.

[0316] The above manufacturing method may include the step of flowing the fertilizer and the fertilizer coating solution to form a coating layer on the fertilizer.

[0317] The above fertilizer may be the same as the fertilizer described above.

[0318] A coating layer can be formed on the fertilizer by spray coating or drum coating using the above fertilizer and the above fertilizer coating solution.

[0319] The above spray coating may refer to a process of forming a coating layer on the fertilizer by flowing the fertilizer under hot air conditions and then spraying the fertilizer coating solution. The slow-release fertilizer produced by the above spray coating may have a uniformly formed coating layer on the fertilizer.

[0320] The specific gravity of the solvent in the above spray coating is 0.5 g / cm³ 3 From 1 to 1.5 g / cm³ 3 Below, 0.5 g / cm³ 3 From 1.48 g / cm³ 3 Less than or equal to 0.5 g / cm³ 3 From 1 to 1.0 g / cm³ 3 It may be less than or equal to the above range. If the above range is satisfied, the solvent can be easily evaporated during the coating process, which can improve process efficiency and minimize the amount of residual solvent, thereby allowing for more efficient recycling of the solvent.

[0321] The drum coating described above may refer to a process of forming a coating layer on the fertilizer by introducing the fertilizer into a drum-shaped housing, flowing the housing under hot air conditions, and then introducing the fertilizer coating solution. A solvent with a high specific gravity may be more suitable for the drum coating, and the thickness of the coating layer may be easily controlled.

[0322] The specific gravity of the solvent in the drum coating is 1.0 g / cm³ 3 From 2.0 g / cm³ 3 Below, 1.0 g / cm³ 3 From 1 to 1.8 g / cm³ 3 Less than or equal to 1.4 g / cm³ 3 From 1 to 1.8 g / cm³ 3 It may be less than or equal to the above range. If the above range is satisfied, controlling the thickness of the coating layer during the coating process may be easier.

[0323] The above spray coating or drum coating may be carried out under temperature conditions of 5°C to 80°C. The above spray coating may be carried out under temperature conditions of 5°C to 50°C, 5°C to 40°C, 5°C to 30°C, 5°C to 25°C, 5°C to 20°C, or 5°C to 15°C. The above drum coating may be carried out under temperature conditions of 40°C to 70°C, 40°C to 65°C, 40°C to 62°C, or 40°C to 60°C.

[0324] The difference between the above temperature and the boiling point of the solvent may be 10 ℃ or less, 8 ℃ or less, 6 ℃ or less, or 5 ℃ or less.

[0325] If the above range is satisfied, the solvent can be volatilized more easily and the amount of residual solvent is minimized, allowing the solvent to be recycled more efficiently.

[0326] After forming a coating layer on the fertilizer, the method may further include the step of filtering with a mesh filter having pores of 100 μm to 1,000 μm, 150 μm to 1,000 μm, 200 μm to 1,000 μm, or 200 μm to 900 μm, and the step of drying at room temperature.

[0327] Through the above filtration and drying steps, the coating layer can be formed more densely and uniformly.

[0328] After forming a coating layer on the fertilizer, the method may further include the step of condensing and recovering the solvent contained in the fertilizer coating solution.

[0329] The process of condensing the above solvent is not particularly limited and can be recovered through a separate condenser. The temperature of the condenser may be 0°C to 10°C.

[0330]

[0331] The present invention will be described in more detail below based on examples and comparative examples. However, the following examples and comparative examples are merely illustrative for further explaining the present invention, and the present invention is not limited by the following examples and comparative examples.

[0332]

[0333] Preparation Example - Preparation of solution for fertilizer coating

[0334] Preparation Example 1

[0335] A resin composition for fertilizer coating was prepared by mixing 10 parts by weight of PHA #1 (poly(3-hydroxybutyrate-co-4-hydroxybutyrate), number average molecular weight 500,000 g / mol, 4-hydroxybutyrate 30 mol %, degree of crystallization 30%), 45 parts by weight of PBS (Polybutylene succinate) #1 (number average molecular weight 45,000 g / mol, degree of crystallization 30%), and 45 parts by weight of PBAT (Polybutylene adipate terephthalate) #1 (number average molecular weight 40,000 g / mol, degree of crystallization 20%).

[0336] Subsequently, the Hansen fractionation variance parameter (f d ) 0.85, Hansen fractionation polarity parameter(f p ) 0.02, and Hansen fractionation hydrogen bonding parameter (f h A fertilizer coating solution was prepared such that the concentration of the resin composition for fertilizer coating was 3% by weight in chloroform with a concentration of 0.13.

[0337]

[0338] Preparation Example 2

[0339] A fertilizer coating solution was prepared by the same process as in Preparation Example 1, except that 10 parts by weight of PHA #2 (number average molecular weight 500,000 g / mol 4-hydroxybutyrate 50 mol %, degree of crystallinity 0%) was used instead of 10 parts by weight of PHA #1 in Preparation Example 1 above.

[0340]

[0341] Preparation Example 3

[0342] A fertilizer coating solution was prepared by the same process as in Preparation Example 1, except that 10 parts by weight of PHA #2 (number average molecular weight 500,000 g / mol, 4-hydroxybutyrate 50 mol %, degree of crystallization 0%) was used instead of 10 parts by weight of PHA #1 in Preparation Example 1, and 45 parts by weight of PBS #2 (number average molecular weight 48,000 g / mol, degree of crystallization 50%) was used instead of 45 parts by weight of PBS #1.

[0343]

[0344] Comparative Manufacturing Example 1

[0345] A resin composition for fertilizer coating was prepared by replacing 10 parts by weight of PHA #1, 45 parts by weight of PBS #1, and 45 parts by weight of PBAT #1 in Preparation Example 1 above with 100 parts by weight of PBAT #2 (number average molecular weight 62,000 g / mol, degree of crystallinity 13%).

[0346] Subsequently, the Hansen fractionation variance parameter (f d ) 0.67, Hansen fractionation polarity parameter(f p ) 0.23, and Hansen fractionation hydrogen bonding parameter (f h A fertilizer coating solution was prepared such that the concentration of the resin composition for fertilizer coating was 5% by weight in 0.10 THF (Tetrahydrofuran).

[0347]

[0348] Comparative Manufacturing Example 2

[0349] A resin composition for fertilizer coating was prepared by replacing 10 parts by weight of PHA #1, 45 parts by weight of PBS #1, and 45 parts by weight of PBAT #1 in Preparation Example 1 above with 100 parts by weight of PVA (Polyvinyl alcohol, acetate content 30%, number average molecular weight 42,000 g / mol, degree of crystallinity 20%).

[0350] Subsequently, the Hansen fractionation variance parameter (f d ) 0.68, Hansen fractionation polarity parameter(f p ) 0.12, and Hansen fractionation hydrogen bonding parameter (f h A fertilizer coating solution was prepared such that the concentration of the resin composition for fertilizer coating was 10% by weight in water with a pH of 0.20.

[0351]

[0352] Example - Preparation of Slow-Release Fertilizer

[0353] Example 1

[0354] An element was introduced into the fluid spray coating machine. Subsequently, air inside the fluid spray coating machine was circulated under conditions of 25°C, and the element flowed.

[0355] A fertilizer coating solution according to Manufacturing Example 1 was sprayed, and the fertilizer coating solution was coated on the surface of the element. Afterward, the spraying was stopped and the solution was dried for 10 minutes to produce a slow-release fertilizer with a coating thickness of about 50 μm.

[0356]

[0357] Example 2

[0358] A slow-release fertilizer was prepared by the same process as in Example 1, except that the fertilizer coating solution according to Example 2 was used instead of the fertilizer coating solution according to Example 1 in Example 1.

[0359]

[0360] Example 3

[0361] A slow-release fertilizer was prepared by the same process as in Example 1, except that the fertilizer coating solution according to Example 3 was used instead of the fertilizer coating solution according to Example 1 according to Example 1 according to Example 1.

[0362]

[0363] Comparative Example 1

[0364] An element was introduced into the fluid spray coating machine. Subsequently, air inside the fluid spray coating machine was circulated under conditions of 60°C, and the element flowed.

[0365] A fertilizer coating solution according to Comparative Manufacturing Example 1 was sprayed, and the fertilizer coating solution was coated on the surface of the element. Afterward, the spraying was stopped and the solution was dried for 10 minutes to produce a slow-release fertilizer with a coating thickness of about 50 μm.

[0366]

[0367] Comparative Example 2

[0368] Urea was introduced into a drum coating machine. Subsequently, a solution for coating a polyurethane (number average molecular weight 38,000 g / mol) fertilizer, produced by the polymerization reaction of polyol and MID (Methylene Diphenyl Diisocyanate) under conditions of 60 ℃, was introduced, and the solution was coated onto the surface of the urea. Afterward, the rotation of the drum coating machine was stopped, and the mixture was dried for 10 minutes to produce a slow-release fertilizer with a coating thickness of approximately 50 μm.

[0369]

[0370] Comparative Example 3

[0371] An element was introduced into the fluid spray coating machine. Subsequently, air inside the fluid spray coating machine was circulated under conditions of 60°C, and the element flowed.

[0372] A fertilizer coating solution according to Comparative Manufacturing Example 2 was sprayed, and the fertilizer coating solution was coated on the surface of the element. Afterward, the spraying was stopped and dried for 10 minutes to produce a slow-release fertilizer with a coating thickness of about 50 μm.

[0373]

[0374] Experimental Example

[0375] Experimental Example 1 - Degree of Crystallinity

[0376] The degree of crystallization was measured for each fertilizer coating resin composition used in Examples 1 to 3 and Comparative Examples 1 to 3. The degree of crystallization was the melting enthalpy (ΔH) measured using Differential Scanning Calorimetry (DSC) according to ASTM D3417. m ) enthalpy of melting in 100% crystal (ΔH c It was calculated as a percentage of the value divided by ). The results are shown in Table 1 below.

[0377]

[0378] Experimental Example 2 - Biodegradable (Composting Conditions)

[0379] For each slow-release fertilizer prepared in Examples 1 to 3 and Comparative Examples 1 to 3 above, the biodegradability was measured for 6 months under composting conditions in accordance with ISO 14855, and the results are shown in Table 1 below.

[0380]

[0381] Experimental Example 3 - Biodegradability (Aqueous Conditions)

[0382] For each slow-release fertilizer prepared in Examples 1 to 3 and Comparative Examples 1 to 3 above, the degree of water hydrolysis was measured for 2 months under water conditions in accordance with ISO 14855, and the results are shown in Table 1 below.

[0383]

[0384] Experimental Example 4 - Emission Characteristics

[0385] 5g of each slow-release fertilizer prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was filled into 495 ml of distilled water with a pH of 7 and then sealed.

[0386] Subsequently, the urea concentration was measured using a urea concentration meter, and the nitrogen concentration was converted based on the urea concentration. In this way, the nitrogen content released from the slow-release fertilizer was measured. The nitrogen content released after 30 days and the nitrogen content released after 60 days were measured relative to the initial nitrogen content in the slow-release fertilizer, and the results are shown in Table 1 below.

[0387]

[0388] Experimental Example 5 - Evaluation of Adhesion Occurrence (During Coating)

[0389] During the manufacturing process of the slow-release fertilizers according to Examples 1 to 3 and Comparative Examples 1 to 3 above, the occurrence of adhesion in the fertilizer coating solution was observed visually and evaluated according to the following criteria. The results are shown in Table 1 below.

[0390] - Good: No adhesion occurred

[0391] - Defect: Adhesion occurs

[0392]

[0393] Experimental Example 6 - Evaluation of Stickiness (After Manufacturing Slow-Release Fertilizer)

[0394] The occurrence of stickiness between the particles of each slow-release fertilizer prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was observed visually and evaluated according to the following criteria. The results are shown in Table 1 below.

[0395] - Good: No adhesion occurred

[0396] - Defect: Adhesion occurs

[0397]

[0398] Experimental Example 7 - Fairness Evaluation

[0399] The sprayability of each fertilizer coating solution of Examples 1 to 3 and Comparative Examples 1 to 3 was evaluated according to the following criteria. The results are shown in Table 1 below.

[0400] - ○: Smooth spraying process

[0401] - ×: Spray nozzle clogging occurred

[0402]

[0403] Experimental Example 8 - Coating Reliability Evaluation

[0404] After leaving 100 samples of each slow-release fertilizer prepared in Examples 1 to 3 and Comparative Examples 1 to 3 at room temperature for 7 days, the occurrence of cracks in the coating layer was observed visually. It was evaluated according to the following criteria, and the results are shown in Table 1 below.

[0405] - ◎: ​​Did not occur

[0406] - ○: 1 or more to 5 or fewer

[0407] - △: More than 5 or fewer than 10

[0408] - ×: More than 10 and up to 50

[0409] - ××: Over 50

[0410]

[0411] Experimental Example 9 - Evaluation of Coating Uniformity

[0412] After 100 units of each slow-release fertilizer prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were placed in each beaker, distilled water was added to the beaker at a rate of 20 ml / min. After 100 ml of distilled water was added, the number of slow-release fertilizers floating on the surface of the distilled water was checked and evaluated according to the following criteria. The results are shown in Table 1 below.

[0413] - ◎: ​​Less than 5

[0414] - ○: 5 or more but less than 10

[0415] - △: 10 or more but less than 30

[0416] - ×: 30 or more

[0417]

[0418] Classification Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Degree of Crystallization 25.5% 22.5% 31.5% 13%-20% Biodegradability Compost Conditions 98.7% 99.1% 98.3% 96.3% 4.2% 41.5% Water System Conditions 95.3% 95.8% 95.1% 96.5% 9.7% 99.4% Release Characteristics After 30 Days 52.2% 53.4% ​​52.1% NA 1) NANA After 60 days 88.3% 89.2% 88.1% NANANA Adhesion occurrence evaluation Coating Medium Good Good Good Poor Good Poor After slow-release fertilizer manufacturing Good Good Good Poor Good Poor Processability evaluation ○○○×○○ Coating reliability evaluation ◎◎◎△◎△ Coating uniformity evaluation ◎◎◎△◎△1) NA: All released before 30-day evaluation

[0419]

[0420] Referring to Table 1 above, it was confirmed that the slow-release fertilizers of Examples 1 to 3, which include a resin composition for fertilizer coating containing a polyhydroxyalkanoate resin and with a crystallinity controlled to 15% to 40%, showed improved adhesion to the fertilizer, controlled release rate of the fertilizer, and improved coating processability compared to the slow-release fertilizers of Comparative Examples 1 to 3.

[0421] Specifically, it was confirmed that the biodegradability of the coating residue in soil as well as in the ocean was improved after the fertilizer's utility was exhausted. In addition, it was confirmed that the release rate within a certain period, which is functionally required for slow-release fertilizers, was controlled because a coating layer could be uniformly formed on the fertilizer. Furthermore, it was confirmed that the adhesion between the fertilizer and the resin composition for fertilizer coating was improved, and the adhesion between the resin compositions for fertilizer coating was suppressed, thereby ensuring the processability of the fertilizer coating and suppressing the occurrence of adhesion between slow-release fertilizers after coating.

[0422]

[0423] The examples can be applied to a resin composition for fertilizer coating, a solution for fertilizer coating, and a slow-release fertilizer, which have excellent biodegradability in soil and ocean after fertilizer release, controllability of the fertilizer release rate, and excellent coating processability.

Claims

It includes a polyhydroxyalkanoate resin, A resin composition for fertilizer coating having a degree of crystallinity of 15% to 40% as measured by Differential Scanning Calorimetry (DSC). In paragraph 1, A resin composition for fertilizer coating in which the number average molecular weight of the polyhydroxyalkanoate resin is 100,000 g / mol to 800,000 g / mol. In paragraph 1, A resin composition for fertilizer coating in which the above polyhydroxyalkanoate resin comprises 3-hydroxybutyrate repeating units and 4-hydroxybutyrate repeating units. In paragraph 3, A resin composition for fertilizer coating in which the above polyhydroxyalkanoate resin contains the above 4-hydroxybutyrate repeating unit in an amount greater than 0 mol % and less than or equal to 50 mol %. In paragraph 1, The above fertilizer coating resin composition comprises a first biodegradable polyester resin comprising a diol-derived unit, an aliphatic dicarboxylic acid-derived unit, and an aromatic dicarboxylic acid-derived unit. In paragraph 5, The above fertilizer coating resin composition comprises a second biodegradable polyester resin having a degree of crystallization of 27% to 60% as measured by the differential scanning calorimeter. In paragraph 6, A resin composition for fertilizer coating in which the content of the polyhydroxyalkanoate resin is 5 to 30 parts by weight based on 100 parts by weight of the total sum of the first biodegradable polyester resin and the second biodegradable polyester resin. In paragraph 1, The above fertilizer coating resin composition comprises a flow promoter including a silicone-based compound. In paragraph 1, The above fertilizer coating resin composition comprises a tack enhancer including a silane coupling agent. It includes a polyhydroxyalkanoate resin, A resin composition for fertilizer coating having a degree of crystallinity of 15% to 40% as measured by Differential Scanning Calorimetry (DSC); and A solution for fertilizer coating containing a solvent. In Paragraph 10, The above solvent is a Hansen fractionation dispersion parameter (f d ) 0.5 to 0.9, Hansen fractionation polarity parameter (f p ) 0 to 0.3, and Hansen fractionation hydrogen bonding parameter (f h A fertilizer coating solution having a content of 0.1 to 0.

4. In Paragraph 10, A fertilizer coating solution having a content of the resin composition for fertilizer coating of 1% to 20% by weight based on the total weight of the fertilizer coating solution. Fertilizer; and It includes a coating layer formed on the above fertilizer, The above coating layer comprises a polyhydroxyalkanoate resin, and The above coating layer is a slow-release fertilizer having a degree of crystallinity of 15% to 40% as measured by Differential Scanning Calorimetry (DSC). In Paragraph 13, The coating layer comprises a first biodegradable polyester resin comprising a diol-derived unit, an aliphatic dicarboxylic acid-derived unit, and an aromatic dicarboxylic acid-derived unit; and A slow-release fertilizer comprising a second biodegradable polyester resin having a degree of crystallization of 27% to 60% as measured by the above differential scanning calorimeter. In Paragraph 13, A slow-release fertilizer in which the volume of the coating layer is 7 volume % to 33 volume % relative to the volume of the fertilizer.

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