JPH11113385A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition having excellent degradability in the soil by making the composition contain an aliphatic polyester and a fertilizer. SOLUTION: This composition is obtained by including an aliphatic polyester and a fertilizer. Further, a caking agent may be contained together with the aliphatic polyester and the fertilizer. The aliphatic polyester may be a polylactic acid. The fertilizer may contain at least one element selected from a group comprising three major elements of fertilizer, that is, nitrogen, phosphoric acid and potassium. The caking agent may contain a binder resin and/or clay. Furthermore, the caking agent may contain an adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an aliphatic polyester resin composition. More specifically, the present invention relates to a resin composition having excellent decomposability in soil.

[0002]

[Prior Art] Pile for lawn stop, vegetation net, seedling pot,
Agricultural and forestry materials such as multi-films and golf tees, civil engineering materials, leisure goods, etc. are mainly polyethylene,
General-purpose resins such as polypropylene and polyvinyl chloride are used. However, these uses (resins) are not only difficult to recover and reuse, but also hardly decompose in the natural environment, so if they remain semi-permanently in the ground or are dumped, the landscape will be damaged. And the destruction of the living environment of marine life.

On the other hand, as a biodegradable polymer of a thermoplastic resin, polylactic acid, a copolymer of lactic acid with another aliphatic hydroxycarboxylic acid, an aliphatic polyhydric alcohol and an aliphatic polycarboxylic acid are used. Aliphatic polyesters have been developed. Some of these polymers are 100% biodegradable in the body of animals within months to one year, or, when placed in soil or seawater, begin to degrade in weeks, and in about one to several years. Disappear. Furthermore, the decomposition products have the property of becoming lactic acid, carbon dioxide, and water that are harmless to the human body.

[0004] In particular, polylactic acid has recently been used in large quantities and inexpensively by the fermentation method of L-lactic acid as a raw material, and has a high decomposition rate in compost. Is expected.

[0005] However, although these polymers have a biodegradable function, their decomposition rates in soil vary, and it is often difficult to say that they are suitable resins depending on the required use. On the other hand, as a method for controlling the biodegradation rate of aliphatic polyester, Japanese Patent Publication No. 6-7847
In JP-A-5, an inorganic filler such as talc, calcium carbonate and silica, and an organic filler such as starch, wood powder and cellulose are blended in an amount of 10 to 50% by volume with an aliphatic polyester, and the average volume of the filler is 4.2. × 10 ^{-3 to} 65.4 μm ³
And controlling the biodegradation rate per unit volume in the range of 90 to 10% of the aliphatic polyester.

However, in the method of adding an inorganic filler, when the inorganic filler is calcium carbonate, the molecular weight decreases during melt mixing, and when the talc or silica is used,
The effect of accelerating the decomposition rate in the soil is not recognized so much.
In the method of adding an organic filler, for example, when a seedling pot is made of starch, there is a problem that the mold grows on the starch and adversely affects the growth of plants, which is unsuitable for a seedling pot. An object of the present invention was to develop a resin composition having a function of accelerating the decomposition rate of an aliphatic polyester in soil and further generating or releasing the compound by decomposition to promote plant growth.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, completed the present invention. That is, the invention according to the present application includes the following [1] to
It is specified by the items described in [11].

[1] A resin composition containing an aliphatic polyester and a fertilizer.

[2] A resin composition containing a binder in addition to the aliphatic polyester and the fertilizer.

[3] The resin composition according to [1] or [2], wherein the aliphatic polyester is polylactic acid.

[4] The resin according to any of [1] to [3], wherein the fertilizer contains at least one element selected from the group consisting of nitrogen, phosphoric acid, and potassium fertilizer. Composition.

[5] The fertilizer is potassium chloride, lime superphosphate, calcium silicate, advanced chemical fertilizer, heavy superphosphate, lime burnt, heavy burnt phosphorus, lime nitrogen, ordinary chemical fertilizer, compound fertilizer The resin composition according to any one of [1] to [3], wherein the resin composition contains at least one selected from the group consisting of: fused phosphorus fertilizer, ammonium sulfate, ammonium phosphate, and potassium sulfate.

[6] The binder comprises a binder resin and / or
Or the resin composition according to any one of [2] to [5], which contains clay.

[7] The resin composition according to any one of [2] to [5], wherein the binder contains an adhesive.

[8] The resin composition according to [6], wherein the binder resin is a biodegradable resin.

[9] The resin composition according to [7], wherein the adhesive is a biodegradable adhesive.

[10] A soil composition containing the resin composition according to any one of [1] to [9].

[11] A soil improvement method comprising applying the resin composition according to any one of [1] to [9] to soil.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
In the present invention, an aliphatic polyester is defined as an aliphatic hydroxycarboxylic acid, an aliphatic polyhydric alcohol and an aliphatic polybasic acid, and a homopolymer, a block copolymer, a random copolymer and a polymer blend and a polymer alloy thereof composed of a mixture thereof. Include.

[Aliphatic hydroxycarboxylic acid] Specific examples of the aliphatic hydroxycarboxylic acid in the aliphatic polyester include, for example, glycolic acid, lactic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid and 5-hydroxyvaleric acid. Examples thereof include hydroxyvaleric acid and 6-hydroxycaproic acid, and a cyclic ester of an aliphatic hydroxycarboxylic acid, for example, a glycolide which is a dimer of glycolic acid and a cyclic ester of 6-hydroxycaproic acid. ε-caprolactone can be mentioned. These can be used alone or in combination of two or more, and lactic acid is particularly preferably used.

[Aliphatic polyhydric alcohol] Specific examples of the aliphatic polyhydric alcohol in the aliphatic polyester include:
For example, ethylene glycol, diethylene glycol,
Triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,3
-Butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, polytetramethylene glycol, 1,4- Cyclohexane dimethanol, 1,4-benzene dimethanol and the like can be mentioned. These can be used alone or in combination of two or more.

[Aliphatic polybasic acid] Specific examples of the aliphatic polybasic acid in the aliphatic polyester include succinic acid, oxalic acid, malonic acid, glutaric acid, adipic acid, and the like.
Pimelic acid, suberic acid, azelaic acid, sebacic acid,
Undecandioic acid, dodecandioic acid, phenylsuccinic acid,
1,4-phenylenediacetic acid and the like can be mentioned. They are,
They can be used alone or in combination of two or more.

As a specific example of the method for producing the aliphatic polyester used in the present invention, the above-mentioned aliphatic hydroxycarboxylic acid, aliphatic polyhydric alcohol, and aliphatic polybasic acid may be used, and a publicly known method may be employed. Can be. For example, in the case of polylactic acid, a method of performing direct dehydration polycondensation using lactic acid or a mixture of lactic acid and an aliphatic hydroxycarboxylic acid as a raw material (for example, a production method described in US Pat. No. 5,310,865), Ring opening polymerization method for melt-polymerizing a cyclic dimer of lactic acid (lactide) (for example, a production method disclosed in US Pat. No. 2,758,987), a cyclic dimer of lactic acid and an aliphatic hydroxycarboxylic acid ,
For example, a ring-opening polymerization method in which lactide or glycolide and ε-caprolactone are melt-polymerized in the presence of a catalyst (for example, a production method disclosed in US Pat. No. 4,057,537), lactic acid, fat Direct dehydration polycondensation of a mixture of an aliphatic dihydric alcohol and an aliphatic dibasic acid (for example, a production method disclosed in US Pat. No. 5,428,126); A method of condensing a polymer with an aliphatic dibasic acid in the presence of an organic solvent (for example, a production method disclosed in European Patent Publication No. 0712880 (A2)) and the like can be mentioned. Is not particularly limited. Further, a small amount of an aliphatic polyhydric alcohol such as glycerin, an aliphatic polybasic acid such as butanetetracarboxylic acid, and a polyhydric alcohol such as a polysaccharide may coexist and be copolymerized. The molecular weight may be increased by using a binder (polymer chain extender) such as a compound.

[Aspects of Aliphatic Polyester] The aliphatic polyester shown in the present invention is, for example, polyethylene oxalate, polybutylene oxalate, polyneopentyl glycol oxalate, polyethylene succinate,
Polybutylene succinate, polylactic acid, copolymer of butylene succinate and lactic acid, copolymer of caproic acid and lactic acid, glycolic acid, polyhydroxybutyric acid, polycaproic acid, copolymer of β-hydroxybutyric acid and β-hydroxyvaleric acid, etc. No. Polylactic acid, polycaproic acid, polyethylene succinate and polybutylene succinate are available at relatively low cost and are preferably used. These can be used alone or in combination of two or more.

The weight average molecular weight (M
The w) and the molecular weight distribution are not particularly limited as long as they can be substantially molded. The molecular weight of the aliphatic polyester used in the present invention is not particularly limited as long as it shows substantially sufficient mechanical properties, but is generally preferably 1 to 500,000 in weight average molecular weight (Mw), 30,000 to 400,000 are more preferable, and 50,000 to 300,000 are still more preferable.

Generally, the weight average molecular weight (Mw) is 1
If the molecular weight is smaller than 10,000, mechanical properties are not sufficient, or if the weight average molecular weight exceeds 500,000, handling may be difficult or uneconomical.

[Fertilizer] The term "fertilizer" used in the specification of the present application includes at least the following concepts. A substance mainly applied to soil to promote plant growth and increase yield. Substances classified into the three elements of fertilizers, namely, nitrogen, phosphate, and potassium. And / or a composition such as a self-sufficient fertilizer or a chemical fertilizer. A composition comprising as a main component. (Here, "main component" means that the content is 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more in terms of dry weight.) Lime fertilizer. Compound fertilizer. Alkaline fertilizer. Acid fertilizer. Basic manure, topdressing, spring manure.

In the present invention, a fertilizer can be added to promote the decomposability of the aliphatic polyester in soil. Preferably, the fertilizer promotes the hydrolysis of the aliphatic polyester, and further, the fertilizer promotes plant growth. The fertilizer is not particularly limited, but is appropriately selected depending on the target plant and the mode of fertilization. Specific examples of fertilizers include, for example, “Chemical Products of 12996 (Chemical Kogyo Nippo, 3-16-8, Nihonbashihamacho, Chuo-ku, Tokyo), 19
Issued on January 24, 1996), ISBN4-87326-2
Compounds having a use as a fertilizer disclosed in "Type 1 Ammonia Carbide Chemical Fertilizers (pages 1 to 24)" of "04-6 C3543", mixtures thereof, chemical fertilizers, chemical fertilizers, ordinary chemical fertilizers, Complex fertilizers can be mentioned. All of those descriptions are part of the disclosure of the present specification by explicitly citing the cited documents and the cited scope,
By referring to the explicitly cited reference ranges, those matters or disclosures that can be directly and uniquely derived by those skilled in the art in view of the matters or disclosures described in the specification of the present application.

Specific examples of the fertilizer include, for example, ammonium chloride (ammonium salt), ammonium sulfate (ammonium sulfate), ammonium nitrate (ammonium nitrate), nitrate soda (nitrite, Chile saltpeter), urea, potassium chloride (potassium chloride), and superphosphoric acid. Lime (overcalcite), calcium silicate (silical), advanced chemical fertilizers (for example, according to the type of nitrogen, ammonium phosphate, phosphorus phosphate, urea phosphate, phosphorus phosphate, phosphate) Phosphorus-based,
Phosphorus nitrate-based, etc.), lime heavy superphosphate (DSP [Doubl
e superphosphate), TSP [Tri
ple superphosphate), heavy burning phosphorus, magnesia heavy burning phosphorus, lime nitrogen (calcium cyanamide), ordinary chemical fertilizers (for example, NK (nitrogen / potash) chemical fertilizers, etc.), compound fertilizers (for example, according to the Fertilizer Control Law) , Chemical fertilizer, molded compound fertilizer, adsorption compound fertilizer, coated compound fertilizer,
Compound fertilizer, compound fertilizer, liquid compound fertilizer, compound fertilizer for home gardening, etc.), molten phosphorus fertilizer (fused magnesium phosphate fertilizer), potassium sulfate, fused potassium, potassium sulfate, potassium nitrate, potassium bicarbonate, Phosphorus ammonium (monoammonium phosphate [MAP], diammonium phosphate [DAP]), peridotite, perseki, slaked lime, quicklime,
Compost, bone meal, fish manure, vegetable oil cake, chicken dung, cow dung, human dung, human waste, organic fertilizer, ordinary chemical, urea-containing phosphorus-containing ammonium sulfate, I
B phosphorus phosphorus, potassium phosphorus nitrate, phosphorus urea sulfur compounded with urea component,
IB CDU Phosphorus, Phosphorous chloride, Phosphorous ammonium salt, Phosphorus ammonium salt, Phosphorus acid salt, Phosphorus acid phosphorus, Phosphorus acid phosphorus,
Phosphorus, Phosphorus, Magnesium-containing phosphorous, urea-phosphorus, Mag-components urea
Examples include urea-sulfurated phosphorus, urea-phosphorus-containing urea phosphorus-added, phosphorous-added clay, organic component-containing compound fertilizer, coating fertilizer, and the like. Their form is not particularly limited, granules,
Powders, aqueous solutions and the like can be mentioned.

For example, a chemical fertilizer manufactured by Mitsui Toatsu Fertilizer Co., Ltd. [trade name, Humilon Eight, Greengrass, Holm Green, Soft 100, Escort, Turf Exclusive 550, Red 45, Super Jumbo (255, 285, 385),
Hiluck (404, 063, 444, 333, 26
2, V56)]. In particular, Humilon Eight,
Green grass, soft 100, escort, turf only 5
50 is suitable because the deterioration of the aliphatic polyester during molding is small.

The amount of addition is not particularly limited and is appropriately determined depending on the desired decomposition rate in soil, but is usually preferably in the range of 1 to 40% by weight based on the aliphatic polyester. If it is less than 1% by weight, the effect of promoting decomposition may not be obtained, and if it is more than 40% by weight, the stability of the strand at the time of extrusion pelletization and the moldability at the time of molding tend to deteriorate.

[Resin Composition] The resin composition according to the present invention is prepared by using a high-speed stirrer or a low-speed stirrer with an aliphatic polyester, a fertilizer, and optionally other additives (plasticizer, inorganic filler, organic filler, etc.). After uniformly mixing, a method of melt-kneading with a single-screw or multi-screw extruder having a sufficient kneading ability can be adopted. Usually, the shape of the resin composition according to the present invention is preferably a pellet, a rod, a powder, or the like.

[Molding] The resin composition according to the present invention is a material suitable for molding such as injection molding, extrusion molding, blow molding, and inflation molding.

[Uses] The resin composition according to the present invention is used for leisure goods such as golf tees, seedling pots, vegetation nets, lawn clasps, multi-films, etc., materials for civil engineering and construction, materials for agriculture, forestry and fisheries. It can be suitably used as a substitute for the resin.

[0035]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which are not of a nature that can be interpreted to narrow the technical scope of the present invention.

EXAMPLE Powder 4 of polylactic acid (trade name: Lacia, manufactured by Mitsui Chemicals)
1 kg of a chemical fertilizer [trade name, 550 for turf only, manufactured by Mitsui Toatsu Fertilizer Co., Ltd.] was mixed with the resulting mixture, and the mixture was pelletized under the conditions of an extruder cylinder set temperature of 150 to 210 ° C. After drying the pellets at 60 ° C. for 10 hours, 180 ° C./100
under conditions of kg / cm ² / 5min, thickness 100μm
Press film was prepared. The obtained film was buried in soil. As a result of observing the state of the film one year later, it was almost decomposed and disappeared.

COMPARATIVE EXAMPLE Powder 4 of polylactic acid (trade name: Lacia, manufactured by Mitsui Chemicals)
kg was pelletized under the conditions of an extruder cylinder set temperature of 150 to 210 ° C. The pellets are dried at 60 ° C for 10
After drying for 180 hours, 180 ° C / 100kg / cm ² / 5m
Under the condition of in, a pressed film having a thickness of 100 μm was prepared. The obtained film was buried in soil. 1
Years later, the film state was almost in the initial state.

[0038]

Industrial Applicability The resin composition according to the present invention is a resin composition which promotes the decomposability of an aliphatic polyester in soil, and the compound produced or released by the decomposition promotes plant growth. effective.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 67/02 C08L 67/02 (72) Inventor Yasuhiro Kitahara 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Mitsui Chemicals Co., Ltd. (72) Inventor Tomoyuki Nakada 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Chemicals Co., Ltd. (72) Inventor Kazuhiko 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Chemicals Co., Ltd. 1190 Kasama-cho, Ward Inside Mitsui Chemicals, Inc.

Claims (11)

[Claims] 1. A resin composition containing an aliphatic polyester and a fertilizer. 2. A resin composition containing a binder in addition to an aliphatic polyester and a fertilizer. 3. The resin composition according to claim 1, wherein the aliphatic polyester is polylactic acid. 4. The resin composition according to claim 1, wherein the fertilizer contains at least one element selected from the group consisting of nitrogen, phosphoric acid and potassium fertilizer. 5. The fertilizer is potassium chloride, lime superphosphate, calcium silicate, advanced chemical fertilizer, heavy superphosphate, lime burnt, magnesia heavy burnt phosphorus, lime nitrogen, ordinary chemical fertilizer, compound fertilizer, The resin composition according to any one of claims 1 to 3, wherein the resin composition comprises at least one selected from the group consisting of fused phosphorus fertilizer, ammonium sulfate, ammonium phosphate, and potassium sulfate. 6. The resin composition according to claim 2, wherein the binder contains a binder resin and / or a clay. 7. The resin composition according to claim 2, wherein the binder contains an adhesive. 8. The resin composition according to claim 6, wherein the binder resin is a biodegradable resin. 9. The resin composition according to claim 7, wherein the adhesive is a biodegradable adhesive. 10. A soil composition containing the resin composition according to claim 1. 11. A soil improvement method, comprising applying the resin composition according to claim 1 to soil.