JPH11116371A - Granular agricultural and horticultural composition comprising degradable coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a granular fertilizer, provided with a film having degradability and coated with the degradable film capable of regulating the fertilizer response period. SOLUTION: This granular agricultural and horticultural composition is obtained by coating the surface of a granular fertilizer with a film material A or a mixture of the film material A with a film material B. The film material A is a biodegradable cellulosic ester composition and the film material B is one or more substances selected from the group consisting of an olefin polymer, a copolymer containing an olefin, a vinylidene chloride polymer, a copolymer containing the vinylidene chloride, a diene-based polymer, waxes, a petroleum resin, a natural resin, a cellulose acetate resin, a polycaprolactone, oils and fats and modified substances thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a granular fertilizer coated with a degradable film. More specifically, the present invention relates to a granular fertilizer coated with a degradable film containing a biodegradable cellulose ester composition as an essential component. The coating of the granular fertilizer used in the present invention is decomposed by soil microorganisms and does not ultimately remain in the soil. In addition, various auxiliaries or chemicals can be added to the coating to adjust the dissolution of the granular fertilizer.

[0002]

2. Description of the Related Art Conventionally, various fertilizers of the fertilizer-control type have been developed for the purpose of exerting a fertilizer effect according to the growth of a crop. In particular, many granular fertilizers in which the surface of the granular fertilizer is covered with a skin covering material have been disclosed and are commercially available. Tokuho 7
For example, as described in U.S. Pat. No. 3,505,505, US Pat. No. 3,295,950, Japanese Patent Publication No. 40-2892.
No. 7, Japanese Patent Publication No. 44-28457, British Patent No. 815829, Japanese Patent Publication No. 37-15832, Japanese Patent Publication No. 42-13681, etc., have proposed various fertilizers of the fertilizer-control type. . However, it is taught that it is difficult to control the dissolution rate of the fertilizer component in any of these fertilizers of the fertilizer effect-control type.

On the other hand, in Japanese Patent Publication Nos. 60-21952 and 60-3040, a coating material containing polyolefin as a main component is used, and when coating the surface of the granular fertilizer, the coating material is applied to the granular fertilizer. A method for forming a film by spraying a solution of the above and simultaneously drying with a hot air stream is disclosed. As a feature of this technology, it is taught that it is possible to adjust the dissolution rate of the granular fertilizer,
And the above-mentioned method of forming a film on the surface of granular fertilizer is widely used in practice. Further, in JP-B-60-3040 and JP-A-55-1672, etc., the dissolution control function is maintained by dispersing an inorganic powder such as talc or sulfur in a coating of a polyolefin resin or the like, In addition, it is shown that the disintegration and decomposition of the residual film after elution are promoted.

[0004]

With these granular fertilizers proposed hitherto, the film does not disintegrate or decompose, and remains in the soil without disintegration even when disintegrated, and the growth of crops and soil There is a danger of causing pollution in the environment and in water and rivers around fields. For these reasons, there is a strong demand for granular fertilizers in which the coating has degradability and the fertilization period can be adjusted. In such a degradable coating, degradability means that it is decomposed by light, oxygen, microorganisms, etc., and it is difficult to control the elution rate of the fertilizer component, especially in the conventional coated granular fertilizer. There was a drawback that the fertilization period was easily affected by the environment such as weather and soil. In addition, it has been pointed out that the film after elution of the fertilizer component remains in soil for a long time without being decomposed.

[0005] Also, many attempts have been made to apply biodegradable resins. For example, JP-A-7-33576 discloses polycaprolactone, polylactic acid, or an aliphatic polyester compound and a cellulose derivative, a low molecular weight polyethylene, paraffin, or the like. Are described. However,
In this case, the melting point of the polycaprolactone used is 6
0 ° C., which may cause blocking during transportation or storage of the product. In addition, since polylactic acid and aliphatic polyester have low solubility in solvents, they are practically difficult.
I have not found anything satisfactory yet. Japanese Patent Publication No. 7-505 discloses a granular fertilizer coated with polycaprolactone.

[0006]

SUMMARY OF THE INVENTION The inventor of the present invention has been eager to select a coating material in order to produce a granular fertilizer coated with a degradable coating whose decomposability is adjustable and the fertilization period is adjustable. After investigation, the present invention has been reached.

That is, the present invention is as follows. (A) A coating material A or a mixture of the coating material A and the coating material B is coated on the surface of the granular fertilizer, the coating material A is a biodegradable cellulose ester composition, the coating material B is an olefin polymer, From the group consisting of copolymers containing olefins, vinylidene chloride polymers, copolymers containing vinylidene chloride, gen-based polymers, waxes, petroleum resins, natural resins, cellulose acetate resins, polycaprolactone, oils and fats and modified products thereof A granular agricultural and horticultural composition, which is one or more selected substances. (B) The coating material A has an average degree of substitution of 2.15 or less;
In a test method having a biodegradability according to ASTM 125209-91, a biodegradable cellulose ester composition containing a cellulose ester that decomposes by 60% by weight or more after 4 weeks based on the amount of generated carbon dioxide gas. (A) The granular agricultural horticultural composition according to (1). (C) The coating material A has an average degree of substitution of 1.0 to 2.15, an average degree of polymerization of 50 to 250, and an equivalent ratio of alkali metal or alkaline earth metal to the amount of remaining sulfuric acid of 0.1 to 1.1. The granular agricultural and horticultural composition according to the above (A), which is a biodegradable cellulose ester composition containing a cellulose acetate ester. (D) The biodegradable cellulose ester composition is composed of a plasticizer and / or an aliphatic polyester in an amount of 0 to 100 parts by weight and a photodegradation accelerator and / or a biodegradation accelerator 0 to 5 parts by weight based on 100 parts by weight of the cellulose ester. The granular agricultural and horticultural composition according to the above (a), (b) or (c), which is a composition containing parts by weight. (E) The granular agricultural and horticultural composition as described in (B) or (C) above, wherein the biodegradable cellulose ester is cellulose acetate. (F) A plasticizer is obtained by adding ε-caprolactone to an aromatic polycarboxylic acid ester containing a phthalic acid ester, an aliphatic polycarboxylic acid ester, a lower fatty acid ester or a phosphoric acid ester of a polyhydric alcohol, and a polyhydric alcohol. The granular agricultural and horticultural composition according to the above (d), which is one or more compounds selected from the group consisting of polyols. (G) The biodegradable cellulose ester composition is a composition containing a plurality of cellulose esters having different degrees of substitution, and a cellulose ester having an average degree of substitution of 2.15 or less,
Containing at least 10% by weight of the entire cellulose ester, and A
In a test method according to STM125209-91,
(B), (B) or (C), wherein the composition is a biodegradable cellulose ester composition that decomposes by 20% by weight or more after 4 weeks based on the amount of generated carbon dioxide.
The granular agricultural horticultural composition according to the above. (H) The granular agricultural and horticultural composition as described in (A) above, wherein the coating material B is a polycaprolactone belonging to polyesters synthesized by ring-opening addition polymerization of ε-caprolactone.

[0008] The granular agricultural and horticultural composition of the present invention is obtained by spraying a solution comprising the above-mentioned coating material onto granular fertilizer, and simultaneously applying a high-speed hot air stream to the position to instantaneously dry and coat the composition. A granular fertilizer characterized in that the coating has degradability and the fertilization period can be adjusted. The biodegradable cellulose ester composition used for the coating material A of the present invention has an average degree of substitution of 2.15 or less (substantially 0%).
) And ASTM (American Society)
(Testing and Materials) 125209-91, which contains a biodegradable cellulose ester that decomposes by 60% by weight or more after 4 weeks based on the amount of carbon dioxide gas generated. Hereinafter, unless otherwise specified, a cellulose ester having an average degree of substitution of 2.15 or less is simply referred to as a low-substituted cellulose ester.

The biodegradable cellulose ester composition used in the present invention has an average degree of substitution of 2.15 or less, an average degree of polymerization of 50 to 250, and an equivalent of alkali metal or alkaline earth metal to the amount of remaining sulfuric acid. Ratio 0.1 ~
It may be a composition containing the cellulose ester of 1.1. Furthermore, the biodegradable cellulose ester composition used in the present invention may be composed of a low-substituted cellulose ester alone, and a plurality of cellulose esters having different degrees of substitution containing 10% by weight or more of the low-substituted cellulose ester. May be configured.

Examples of the cellulose ester include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; inorganic acid esters such as cellulose nitrate, cellulose sulfate, and cellulose phosphate; cellulose acetate propionate; Hybrid esters such as butyrate, cellulose acetate phthalate and cellulose nitrate acetate are exemplified. These cellulose esters can be used alone or in combination of two or more. Among these cellulose esters, organic acid esters, particularly cellulose acetate, are preferred.

The low-substituted cellulose ester contained in the cellulose ester composition has an average degree of substitution of 2.15 or less,
Preferably 1.0 to 2.15, more preferably 1.1.
About 2.0. When the degree of substitution is less than 1.0, the water resistance of the surface of the granular fertilizer decreases, and when it exceeds 2.15, not only compatibility with other components and melt fluidity but also biodegradability significantly decrease. The substitution degree DS of the cellulose ester
Is described by taking cellulose acetate as an example, when the bound acetic acid% (degree of acetylation) is X and Y = X / 100, it can be calculated by the following equation. Degree of substitution DS = (162 × Y) / (60−42 × Y)

The average degree of polymerization of the cellulose ester is, for example, about 50 to 250, preferably about 100 to 200. If the average degree of polymerization is less than 50, the mechanical properties of the surface of the granular fertilizer decrease, and if it exceeds 250, not only fluidity and coating properties but also biodegradability decrease. The average degree of polymerization (DP) of the cellulose ester can be measured using an Ostwald viscometer. For example, a solvent solution of cellulose ester,
For the solvent, the drop time from the viscometer was 25
C., and the average degree of polymerization can be calculated by the following formulas (1) to (4). (1) η _rel = t / t ₀ (2) ln η _rel = 2.326 × log η _rel (3) [η] = (ln η _rel ) / C (4) DP = [η] / 9 × 10 ^-4 Where t is the falling time (seconds) of the cellulose ester solution,
t ₀ indicates the falling time (second) of the solvent, and C indicates the concentration (g / L) of the cellulose ester in the solution. In the above method, acetone is often used as the solvent, and the concentration of the cellulose ester in the solution is usually about 0.2%.
(W / v).

The type of the low-substituted cellulose ester is not particularly limited as long as the cellulose ester is excellent in biodegradability. Such a low-substituted cellulose ester may be, for example, in a test method according to the above-mentioned ASTM 125209-91, 60% by weight or more, preferably 65% by weight or more (for example, 65% by weight) after 4 weeks, based on the amount of carbon dioxide gas generated. 〜100%) decomposed cellulose esters. When measuring biodegradability, activated sludge from a municipal sewage treatment plant can be used as activated sludge. The decomposition rate (%) of the cellulose ester can be calculated from the ratio of the amount of carbon dioxide generated to the number of decomposed carbon atoms and the ratio to the total number of carbon atoms before decomposition.

The amount of sulfuric acid remaining in the low-substituted cellulose ester and the equivalent ratio of the alkali metal or alkaline earth metal have a great effect on the biodegradability of the low-substituted cellulose ester. The low-substituted cellulose ester having excellent biodegradability has, for example, an equivalent ratio of alkali metal and / or alkaline earth metal to the remaining sulfuric acid of 0.
1 to 1.1, preferably about 0.5 to 1.1 cellulose ester is included. If the equivalent ratio of the alkali metal and / or alkaline earth metal is less than 0.1, the heat resistance is low, and if it exceeds 1.1, the biodegradability of the cellulose ester is reduced.

The sulfuric acid is derived from sulfuric acid used as a catalyst when producing a cellulose ester. Sulfuric acid may remain free as free sulfuric acid as well as sulfate, sulfoacetate or sulfate.
The total amount of sulfuric acid remaining in the cellulose ester was SO ₄ ^2-
In conversion, usually 1.8 × 10 ^{−3 to} 6.0 × 10 ⁻² % by weight
(0.005 to 0.1 mol%).

The alkali metals include lithium, potassium, sodium and the like, and the alkaline earth metals include magnesium, calcium, strontium, barium and the like. The biodegradable cellulose ester composition used in the present invention may be a composition having improved biodegradability, and the composition has an average degree of substitution of 2.15 or less,
Average polymerization degree of 50 to 250, and equivalent ratio of alkali metal or alkaline earth metal to residual sulfuric acid of 0.1
~ 1.1.

The biodegradable cellulose ester composition used in the present invention may be composed of a low-substituted cellulose ester alone, or a plurality of cellulose esters having different degrees of substitution as long as the low-substituted cellulose ester is included. May be included. A composition composed of a plurality of cellulose esters having different degrees of substitution contains the low-substituted cellulose ester and another cellulose ester (hereinafter, unless otherwise specified, simply referred to as a highly-substituted cellulose ester).

The degree of substitution of the high-substituted cellulose ester may be different from that of the low-substituted cellulose ester, and the substituent may be the same as or different from the low-substituted cellulose ester. You may. The highly substituted cellulose ester includes a highly substituted cellulose ester having poor biodegradability (for example, a cellulose ester having a substitution degree of 2.2 or more, more preferably 2.4 or more).

The preferred high-substituted cellulose ester often has the same or similar substituent as the low-substituted cellulose ester, particularly the same substituent. When the low-substituted cellulose ester is cellulose acetate, the same or similar substituent includes an organic acid ester residue having about 1 to 4 carbon atoms.

A feature of the composition containing a plurality of cellulose esters having different degrees of substitution is that the biodegradability of the cellulose ester can be enhanced even if the content of the low-substituted cellulose ester is small. The content of the low-substituted cellulose ester is about 10% by weight or more, preferably 10 to 90% by weight, more preferably about 10 to 75% by weight (for example, about 10 to 50% by weight) of the whole cellulose ester. Low substituted cellulose ester content of 10
When the content is not less than% by weight, the biodegradability of cellulose ester having poor biodegradability can be dramatically improved. 10% by weight of low-substituted cellulose ester as a cellulose ester component
The cellulose ester composition containing the above is ASTM125
In a test method according to 209-91, the composition is decomposed by 20% by weight or more, preferably 25% by weight or more after 4 weeks, based on the amount of carbon dioxide gas generated. As the content of the low-substituted cellulose ester increases, the cellulose ester composition can be biodegraded in a short time.

The mechanism of biodegradation in such a composition is not clear, but by adding a small amount of low-substituted cellulose ester, microorganisms that do not originally have degradability to high-substituted cellulose ester can be adapted. As a result, it is presumed that the high-substituted cellulose ester is also decomposed.

The cellulose ester can be produced by a conventional method regardless of the degree of substitution. The degree of substitution of the cellulose ester may be adjusted by a single-step reaction in the reaction of cellulose with an organic acid or an acid anhydride. After production, the degree of substitution may be adjusted by hydrolysis.

The substance used as the coating material B in the present invention includes olefin polymers, copolymers containing olefins, vinylidene chloride polymers, copolymers containing vinylidene chloride, diene polymers, waxes, petroleum resins, One or more substances selected from the group consisting of natural resins, cellulose acetate resins, polycaprolactone, fats and oils, and modified products thereof.

The above-mentioned olefin polymer includes polyethylene, polypropylene, ethylene-propylene copolymer,
Polybutene, butene-ethylene copolymer, butene-propylene copolymer, polystyrene, etc., and copolymers containing olefins include ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid Ester copolymer, ethylene / methacrylic acid copolymer,
Ethylene / methacrylic acid ester copolymer, ethylene / carbon monoxide copolymer, ethylene / vinyl acetate / carbon monoxide copolymer and the like. The copolymer containing vinylidene chloride is a vinylidene chloride / vinyl chloride copolymer, and the diene polymer is a butadiene polymer, an isoprene polymer, a chloroprene polymer, a butadiene / styrene copolymer, and an EPDM polymer. And styrene-isoprene copolymer. The waxes are beeswax, wood wax, paraffin and the like, and the natural resins are natural rubber, rosin and the like.
The cellulose acetate resin is a diacetate having an average degree of substitution of 2.5 and a triacetate having an average degree of substitution of 2.9.
Polycaprolactone is a polyester formed by ring-opening addition polymerization of ε-caprolactone, having a molecular weight of 10,000 or more,
Preferably, it is 50,000 to 100,000, and the fats and oils and modified products thereof include hardened oils, solid fatty acids and metal salts.

The weight percentage of the coating material of the present invention with respect to the coated granular material, that is, the coating ratio is preferably 2 to 20%. The coating material A is 10 to 100% of the entire coating material.
% (Weight), preferably in the range of 50 to 100%, and the coating B is used in the range of 0 to 90% (weight), preferably 0 to 50% of the entire coating material. Note that a third coating material component that can be mixed as necessary is used.

Examples of such a third coating material component include a surfactant as an elution controlling agent, and talc, calcium carbonate, and metal oxides as insoluble fillers. These mixtures need to be dispersed uniformly. If it is not uniform, some of the fine particles will be offset and the continuous phase of the coating material will be impaired, and the effect of the coating will be lost.

In the present invention, a fourth coating material component is further used as necessary. Examples of such a fourth coating material component include a photodegradation accelerator and a biodegradation accelerator, an elution regulator, a filler, a cellulose powder, and the like, and these components can be uniformly dispersed and used.

Examples of the photodecomposition accelerator include benzophenones such as benzoins, benzoin alkyl ethers, benzophenone, and 4,4'-bis (dimethylamino) benzophenone and derivatives thereof; acetophenone,
Acetophenones such as α, α-diethoxyacetophenone and derivatives thereof; quinones; thioxanthones; photoexciting materials such as phthalocyanine, anatase-type titanium oxide, ethylene-carbon monoxide copolymer, sensitization of aromatic ketones with metal salts And the like. One or more of these photolysis accelerators can be used. When a photodegradation accelerator is used, cellulose ester can be photodegraded. Therefore, biodegradability can be enhanced in combination with photodegradability.

Examples of the biodegradation accelerator include oxo acids (for example, oxo acids having about 2 to 6 carbon atoms such as glycolic acid, lactic acid, citric acid, tartaric acid, and malic acid), saturated dicarboxylic acids (for example, oxalic acid). Organic acids such as malonic acid, succinic acid, succinic anhydride, glutaric acid, etc. and low saturated dicarboxylic acids having about 2 to 6 carbon atoms); these organic acids and 1 to 4 carbon atoms
Lower alkyl esters with alcohols are included. Preferred biodegradation accelerators include organic acids having about 2 to 6 carbon atoms, such as citric acid, tartaric acid, and malic acid. One or more of these biodegradation accelerators can be used.

As the biodegradation accelerator, biodegradation enzymes,
For example, hydrolytic enzymes such as lipase, cellulase, and esterase are also included. The biodegradable enzyme can be used by suspending or dispersing it in a solvent. The photodegradation promoter and the biodegradation promoter can be used in combination.
It is also possible to mix cellulose powder to prevent aggregation of the coated granules, but in the present invention, the melting point of low-substituted cellulose acetate is 140 ° C. or higher, and is unnecessary.

In the present invention, the coating material is dissolved or dispersed in a solvent such as chlorinated hydrocarbons, kept at a high temperature, added to the surface of the granular fertilizer in the form of spray, and at the same time, a high-speed hot air flow is applied to the position. Granular fertilizer is obtained by coating while drying instantly. Acetone, which is easily available, can be used as the solvent.

[0032]

The present invention will be described below in detail with reference to examples and comparative examples. (1) Apparatus and Manufacturing Method FIG. 1 shows a preferred example of the apparatus of the present invention. Spout tower 1
Has a tower diameter of 200 mm, a height of 180 mm, and an air ejection diameter of 42 mm
And has a fertilizer input port 2 and an exhaust gas outlet 3. The jet air is sent from the blower 10 and reaches the jet tower via the orifice flow meter 9 and the heat exchanger 8. The flow rate is controlled by a flow meter 9, the temperature is controlled by a heat exchanger 8, and the exhaust gas is guided from the exhaust gas outlet 3 to the outside of the tower. The granular fertilizer to be subjected to the coating treatment is injected from the fertilizer input port 2 while passing through a predetermined hot air to form a jet. In the coating treatment, the coating liquid containing the cellulose acetate composition having a low degree of substitution is sprayed through the liquid nozzle 4 toward the jet after the coating particle temperature reaches a predetermined temperature.
The coating liquid is prepared by putting a predetermined amount of the coating material and a solvent into the liquid tank 11 and stirring the mixture near the boiling point of the solvent. The supply of the coating liquid is sent to the nozzle 4 by the pump 5, and the system is kept sufficiently warm to maintain the temperature. When a predetermined coating liquid is supplied, the pump 5 is stopped, and then the blower 10 is stopped. The coated fertilizer is removed from the outlet 7. 6 is a valp. In FIG. ₁ , T ₁ ,
T ₂ and T ₃ are thermometers, and SL is steam. In each of the examples and comparative examples, the granular fertilizer was coated while maintaining the following basic conditions.

Liquid nozzle; 0.8 mm full-con type opening Hot air volume: 4 m ³ / min Hot air temperature: 100 ° C. Type of fertilizer: 5-7 mesh phosphoric acid ammonium salt Fertilizer input amount: 5 kg Coating solution concentration: solid content 5% by weight Liquid supply amount: 0.5 kg / min Coating time: 10 minutes Coverage (to fertilizer); 5.5% by weight (including surfactant) Solvent: tetrahydrofuran (abbreviated as THF in the table), trichloroethylene ( EVA; manufactured by Tosoh Corporation [Ultracene (ethylene vinyl acetate, vinyl acetate content: 32)] Low-substituted cellulose acetate; Daicel Chemical Industries, Ltd. [acetylation degree: 51.0, 6] % Cps of acetone solution 98 cps] diacetate; manufactured by Daicel Chemical Industries, Ltd. [degree of acetylation 5]
5.0, 6% Viscosity of 6% Acetone Solution 100 cps] Triacetate; Daicel Chemical Industries, Ltd. [Acetification degree 6]
0.0,6% methylene chloride solution viscosity 300cp
s] PCL; Polycaprolactone [PCL-H7] manufactured by Daicel Chemical Industries, Ltd.

(2) Coating Composition and Biodegradation Test Coated phosphoric acid nitrates Akari having various coating compositions shown in Table 1 were manufactured by the above-mentioned manufacturing method. Thereafter, 50 coated samples of the present example were cut on two sides one by one, left in water to remove the fertilizer therein, dried and finely pulverized, and then subjected to JIS K6950 (activated sludge). Degradation rate was determined by aerobic biodegradation test method). The activated sludge used was the sludge returned from the Himeji Sewage Treatment Plant. Examples 1-4
Table 1 shows the results of Comparative Example 1.

[0035]

[Table 1]

[0036]

Industrial Applicability The granular fertilizer of the present invention can control the duration of fertilization, and after elution of the fertilizer, the film is disintegrated and decomposed by soil microorganisms and does not remain in the soil. Furthermore, the amount of residual components after the cultivation period of the crop disappears due to the disintegration and decomposition of the film, which has the effect of facilitating fertilizer management.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of an apparatus suitable for manufacturing an invention.

[Brief description of reference numerals]

1 jet column, 2 fertilizer inlet, 3 gas ejection port, 4-fluid nozzle, 5 pump, 6 valves, 7 extraction port, 8 heat exchanger, 9 orifice meter, 10 a blower, 11 tank, T _1, T ₂ , T ₃ thermometer, SL steam

Claims (8)

[Claims] 1. Coating material A or coating material A and coating material B
Is coated on the surface of the granular fertilizer, and the coating material A
Is a biodegradable cellulose ester composition, and the coating material B
Is an olefin polymer, an olefin-containing copolymer, a vinylidene chloride polymer, a copolymer containing vinylidene chloride, a gen-based polymer, a wax, a petroleum resin, a natural resin, a cellulose acetate resin, a polycaprolactone, an oil and a modification thereof. A granular agricultural and horticultural composition, which is one or more substances selected from the group consisting of: 2. A coating material A having an average degree of substitution of 2.15 or less and a biodegradability of 60% by weight or more after 4 weeks in a test method according to ASTM 125209-91, based on the amount of carbon dioxide gas generated. The granular agricultural and horticultural composition according to claim 1, which is a biodegradable cellulose ester composition containing a cellulose ester. 3. The coating material A has an average degree of substitution of 1.0 to 2.1.
5, the average degree of polymerization is 50 to 250, and the equivalent ratio of the alkali metal or the alkaline earth metal to the amount of the remaining sulfuric acid is 0.1.
The granular agricultural and horticultural composition according to claim 1, wherein the composition is a biodegradable cellulose ester composition containing a cellulose acetate ester which is from 0.1 to 1.1. 4. The biodegradable cellulose ester composition,
A composition comprising 0 to 100 parts by weight of a plasticizer and / or an aliphatic polyester and 0 to 5 parts by weight of a photodegradation accelerator and / or a biodegradation accelerator with respect to 100 parts by weight of a cellulose ester. The granular agricultural and horticultural composition according to claim 1, 2, or 3. 5. The granular agricultural and horticultural composition according to claim 2, wherein the biodegradable cellulose ester is cellulose acetate. 6. A plasticizer comprising ε-caprolactone as an aromatic polycarboxylic acid ester containing a phthalic acid ester, an aliphatic polycarboxylic acid ester, a lower fatty acid ester or a phosphoric acid ester of a polyhydric alcohol, and a polyhydric alcohol. The granular agricultural and horticultural composition according to claim 4, wherein the composition is one or more compounds selected from the group consisting of added polyols. 7. The biodegradable cellulose ester composition,
A composition comprising a plurality of cellulose esters having different degrees of substitution, comprising a cellulose ester having an average degree of substitution of 2.15 or less in an amount of 10% by weight or more of the entire cellulose ester, and producing carbonic acid generated in a test method according to ASTM 125209-91. 20 weeks after 4 weeks based on gas volume
The granular agricultural and horticultural composition according to claim 1, wherein the composition is a biodegradable cellulose ester composition that decomposes by weight percent or more. 8. The granular agricultural and horticultural composition according to claim 1, wherein the coating material B is a polycaprolactone belonging to polyesters synthesized by ring-opening addition polymerization of ε-caprolactone.