JP2001348019A - Biodegradable bottle for agricultural chemical - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biodegradable and disposable bottle for agricultural chemicals. SOLUTION: This bottle for agricultural chemicals is formed of a mixture of 10-70 pts.wt. polyhydroxy alkanoate containing 3-hydroxy butyric acid unit and 90-30 pts.wt. polylactic acid, polybutylene succinate, polybutylene carbonate or polycaprolactone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a disposable biodegradable agricultural chemical bottle.

[0002]

2. Description of the Related Art Conventionally, high-density polyethylene molded articles have been used because pesticide bottles are inexpensive, light and hard to break. When the moisture permeability is too large, the one coated with nylon or eval is used, and after using pesticides, each farmer has disposed by incineration individually. However, in recent years, the burning of plastics that may generate dioxin has been banned, and plastic agricultural materials such as used agricultural multi-films, fertilizer bags, and pesticide bottles have lost their disposal methods. In some areas, farmers wash these used plastics, bring them to a processing company and outsource the processing for a fee, but because of the complexity, agricultural materials that can be embedded in soil and decomposed are desired.

[0003] Regarding agricultural multi-films, biodegradable multi-films have been developed by various companies and sales have begun in some districts. However, although agricultural bottles have been temporarily tested, their physical properties are insufficient. This has left consideration suspended.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art and to provide an agrochemical bottle excellent in biodegradability.

[0005]

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 above-mentioned problem can be solved by using a bottle made of a specific biodegradable resin as a raw material instead of a conventionally used bottle mainly composed of high-density polyethylene. That is, the present invention relates to 10 to 70 parts by weight of a polyhydroxyalkanoate containing a 3-hydroxybutyric acid unit and 90 to 30 parts by weight of a thermoplastic biodegradable resin such as polylactic acid, polybutylene succinate, polybutylene carbonate or polycaprolactone. And a disposable biodegradable pesticide bottle which is disintegrated over time by injection molding or extrusion molding using the mixture of the above. Since the pesticide bottle of the present invention gradually decomposes in water, soil or compost, it does not remain semipermanently as it is, and because it does not require incineration, it can generate harmful substances such as dioxin. Absent.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Polyhydroxyalkanoates containing 3-hydroxybutyric acid units used in the present invention are aliphatic polyesters produced by microorganisms, and are widely studied biodegradable resins. Typical resins include polyhydroxybutyric acid (hereinafter abbreviated as PHB) and a copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid (hereinafter referred to as PB).
HB / PHV copolymer). These polyhydroxyalkanoates include, for example, Alcaligenes (Al
genus Caligenes, Azoto (Azoto)
bacterium, Methylobacterium (Methyl)
obacterium, Nocardia
ia) genus, Pseudomonas
It can be produced by obtaining bacterial cells containing polyhydroxyalkanoate by a known fermentation method using bacteria of the genus or the like. With respect to a method for separating and purifying polyhydroxyalkanoate from the obtained bacterial cells, for example, US Pat.
No. 33, No. 3,275,610 and European Patent No. 15123, pyridine, methylene chloride,
1,2-propylene carbonate, chloroform, 1,
A purification method using a solvent such as 2-dichloroethane is described, and JP-A-7-177894 discloses that after separating bacterial cells with a high-pressure homogenizer, polyhydroxyalkanoate is separated, and the separated polyhydroxyalkanoate is separated. A method of treating an alkanoate with an enzymatic bleach is described. Japanese Patent Application Laid-Open No. 7-75590 discloses that polyhydroxyalkanoate is accumulated in cells by continuously culturing methanol-assimilating bacteria using methanol as a carbon source. Recently, a method for producing a polyhydroxyalkanoate containing a 3-hydroxybutyric acid unit by chemical synthesis without using a fermentation method has been reported.

[0007] Biodegradable resins are produced by microorganisms.
In addition to polyhydroxyalkanoates containing a hydroxybutyric acid unit, polylactic acid, aliphatic polyesters (eg, polybutylene succinate, polyester carbonate, etc.) composed of glycols and aliphatic dicarboxylic acids, and polycaprolactone can also be mentioned. However, for the pesticide bottle of the present invention, it is best to use a mixture of a polyhydroxyalkanoate containing a 3-hydroxybutyric acid unit produced by a microorganism and these thermoplastic biodegradable resins.
This is because these biodegradable resins alone are unsuitable in terms of physical properties as pesticide bottles. That is, polylactic acid, polybutylene succinate, polyester carbonate, and polycaprolactone have high moisture permeability, water is diffused during storage, and the liquid agent cannot be maintained at a predetermined concentration. As these pesticide bottles, biodegradable resins with problems are
By molding a pesticide bottle using a resin mixed with a polyhydroxyalkanoate containing a hydroxybutyric acid unit, moisture permeability is improved.

The resin for forming the pesticide bottle of the present invention comprises 10 to 70 parts by weight of a polyhydroxyalkanoate containing a 3-hydroxybutyric acid unit and polylactic acid, polybutylene succinate, or a thermoplastic biodegradable resin. It consists of 90-30 parts by weight of butylene carbonate or polycaprolactone. When the amount of the polyhydroxyalkanoate containing 3-hydroxybutyric acid unit is less than 10 parts by weight, there is no sufficient modifying effect, and the water resistance, the organic solvent resistance, and the water resistance become insufficient. If it exceeds, the rigidity of the molded article increases, and at the same time, the elasticity decreases, so that it cannot be used as an agricultural chemical bottle.

The pesticide bottle of the present invention has a size of 150 to 22.
Heat molding at 0 ° C. is preferred. If the temperature is lower than 150 ° C., the resin may not be sufficiently melted.
If the temperature is higher than 20 ° C., satisfactory performance may not be obtained due to deterioration of the polyhydroxyalkanoate containing a 3-hydroxybutyric acid unit. An inorganic filler such as calcium carbonate can be added to the pesticide bottle of the present invention in order to stabilize physical properties. From the viewpoints of moldability and economy, it is preferable that the addition amount is such that the resin composition for forming the agricultural chemical bottle is 70 to 95 parts by weight and the inorganic filler is 30 to 5 parts by weight.

A polyhydroxyalkanoate containing a 3-hydroxybutyric acid unit and a thermoplastic biodegradable resin such as polylactic acid and polybutylene succinate, which do not depart from the scope of the present invention and do not impair the object of the present invention. Polybutylene carbonate or polycaprolactone, and substances other than inorganic fillers, such as crystallization accelerators such as boron nitride, pigments such as titanium oxide, mold release agents, antistatic agents, ultraviolet absorbers, and antioxidants, commonly used additives An agent can be added according to the purpose.

[0011]

According to the present invention, it is possible to obtain a biodegradable pesticide bottle which maintains strength and moisture resistance close to those of conventionally used pesticide bottles and decomposes in the natural world, and reduces the load on the natural environment. Can be expected.

[0012]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Example 1 20 parts by weight of PHB powder, 0.5 part by weight of boron nitride fine powder as a crystallization agent, and 69.5 parts by weight of pellets of polybutylene succinate (trade name: Bionore # 1020, manufactured by Showa Polymer Co., Ltd.) Then, 10 parts by weight of fine powdered calcium carbonate (trade name: AFF, manufactured by Fimatec Co., Ltd.) was mixed and melt-molded with a pelletizer as an inorganic filler to obtain pellets of the mixed resin. This mixed resin pellet was molded at 180 ° C. using an agricultural chemical bottle (500 ml capacity) mold by an extrusion blow molding machine (referred to as bottle A of the present invention). The drop impact strength and moisture permeation resistance of the molded bottle were determined. Table 1 shows the determination results.

[0013]Table 1 Bottle drop strength * 1) Moisture permeability * 2 Inventive bottle A ○ ○ Polybutylene succinate bottle ○ × Note 1) Drop strength: A bottle containing 500 ml of water must be dropped vertically onto the concrete from a height of 1.2 m to prevent cracking. Note 2) Water permeability: 500 g of bottle with 500 g of distilled water and sealed. And leave it at 23 ° C and 50% humidity. Weight loss per month (g) / 500ml × 100% was measured, 0.1% or less was passed (○), 0.1% or more was rejected (×)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 69/00 B65D 1/00 BSF

Claims (1)

[Claims] 1. A mixture comprising 10 to 70 parts by weight of a polyhydroxyalkanoate containing 3-hydroxybutyric acid units and 90 to 30 parts by weight of polylactic acid, polybutylene succinate, polybutylene carbonate or polycaprolactone. Biodegradable pesticide bottle.