JPH0822802B2 - Soluble sachet - Google Patents

Description

Detailed Description of the Invention

The present invention relates to a package in which a liquid drug or a drug dissolved or dispersed in a liquid or a gel is contained in an envelope of a water-soluble or water-dispersible material.

Currently, the most dangerous liquids are stored in metal drums or, in small quantities, in plastic containers.

Hazardous compounds, especially agrochemical compounds, are formulated in various ways. However, it is particularly desirable for the farmer to have the compound in a liquid form for handling. This is because the liquid compound is easy to disperse. However, handling liquids is difficult and has drawbacks. Holes in the container may cause liquid to spill or leak to the ground. The container may be damaged by physical shock.

[0004] It is thus difficult to devise a container system that is suitable for farmers, safe in terms of container handling, and environmentally safe.

It is known that pesticides can be contained in dissolvable bags or sachets made from film. However, the film may be broken or torn and the contained pesticide may be spilled. In fact, the various drawbacks of a film make it a weak point in the film and, consequently, a potential source of leakage. Any air bubbles, dust particles or other foreign matter, gel particles or thin areas present on or in the film are potential weaknesses. If the film having such a weak point is repeatedly used or the film is subjected to a physical shock, the film will be broken at the weak point. This is a particular problem in the agrochemical industry, where distributors or farmers carelessly handle containers unsafely.

The above-mentioned weaknesses of the film are more or less certain films of a particular type, depending on the manufacturing method.
When making a film by casting,
There are few pinholes, but often there are many tiny pieces of gel inclusions. When the film is made by extrusion, there are many pinholes.

It is an object of the present invention to provide a novel container system for pesticides which is safe to handle.

Another object of the present invention is to provide a new container system for pesticides which is easy to handle for the end user (eg a farmer).

A further object of the present invention is to provide a novel container system for pesticides which reduces the risk of pollution and environmental damage.

In one aspect, the present invention is directed to preventing liquid or dissolved chemicals from leaking through pinholes in a film container system. Pinholes are generally rare, but the presence of only one pinhole in thousands of containers can cause significant damage. This is because the liquid in the container passes through the pinhole and pollutes the surrounding environment.

Other objects and features of the present invention will be apparent from the following description.

The container system according to the invention is characterized in that the dangerous material in liquid or gel form is contained in a water-soluble or water-dispersible bag made from a laminated film.

According to a preferred feature of the invention, the hazardous compound is a pesticide, such as an insecticide or a plant protection agent or a plant growth regulator.

Accordingly, the present invention provides a package in which a dangerous chemical dissolved or dispersed in a liquid or gel is contained in a water-soluble or water-dispersible laminated film.

As used herein, the term laminate film refers to a film made from two or more originally separate layers joined together. The layers are joined together in a known manner to form a laminate. For example, the layers or laminates can be joined using pressure, heating, crosslinking, melting, gluing or combinations thereof. The layers can also be attached using another adhesive, or preferably water.

When a suitable water-soluble or water-dispersible layer is used, a particularly convenient method of making a laminated film is by using adhesive PVA (generally low molecular weight) and / or more conveniently by water. Adhering the separate layers.

Since more than two layers are used to produce the laminated film, the rate of pinholes in the film is reduced to near zero. This is because there is no possibility of overlapping even if there are two pinholes in different layers. Moreover, the tensile strength of multilayer (eg, two-layer) films is better than that of similar films of the same thickness made from single layers.

The laminate film used in the present invention generally has a thickness of 10 to 250 microns, preferably 15 to 80 microns. The layers that make up the laminated film used in the present invention are generally half the thickness of these numbers. When using two layers, the thickness ratio of the two layers is generally 0.1 to 10, preferably 0.5 to 2. The volume of bags or sachets made from a laminated film according to the invention is generally 0.2 to 12 liters, preferably 0.45 to 6 liters.

The materials that can be used in the present invention are water-soluble or water-dispersible materials that are insoluble in the organic solvent used to dissolve or disperse the contained chemicals. Suitable materials include polyethylene oxide or methyl cellulose, but the material consists of or is derived from polyvinyl alcohol, i.e. partially or completely (e.g. 40-99%, preferably 70-9).
2%) alcoholysis or hydrolyzed polyvinyl acetate film is preferred.

The layers of the laminated film of the present invention may be made of the same material or different materials. Films made from layers of different materials can have beneficial properties. For example, it may be more resistant to pesticides containing the inner layer of the package. In addition, the outer layer of the bag can be selected to have one or more of the following properties: i. Faster dissolution (compared to inner or single layer packaging), ii. Having improved mechanical properties, including improved resistance to mechanical damage, iii. Have improved machinability, iv. Less sensitive to relative humidity, v. Tolerant to freezing and / or high temperatures.

A plasticizer may be contained in one or more layers of the laminate film. Including a suitable amount of plasticizer in the inner layer,
The sealing properties of the film are improved and the film is less stretched. This allows the film to be more easily machined and sealed around dangerous liquids. Including a suitable amount of plasticizer in the outer layer of the container makes the outer surface more flexible and more resistant to physical damage and migration from cold or shock.

The layers of the laminated film can be made using various methods such as extrusion or casting. Laminates made from layers made by different methods can have beneficial properties including better flexibility, higher strength and higher resistance to stretching. High strength and / or improved resistance to stretching exists in one direction of the film. The laminate film used in the present invention is used to make packages that prevent the time consuming and dangerous consequences of conventional packages where film defects cause leakage during the encapsulation or subsequent handling steps. It

As already mentioned, the bag (or container system) may contain a liquid or gel. A preferred feature of the present invention is the bag or container system of the present invention comprising a gel.

According to a preferred feature of the present invention, the gel is selected to have one or more of the following features: * The gel obtained forms a continuous system, * The gel obtained is 500-50,000 centipoise, more It preferably has a viscosity of 1000 to 12,000 centipoise (these viscosities are Brookfield viscosities measured at room temperature using a plate viscometer rotating at 20 rpm).

* The gel has a phase difference (φ) between the controlled shear stress and the resulting shear strain such that the tg (φ) is 1.5 or less, preferably 1.2 or less. Tg (φ) is the angle φ
It is the tangent of (phase difference). φ is measured at room temperature by a rheometer with a stationary plate and a rotating cone on this plate, the angle between the plate and the cone being for example less than 10 °, preferably less than 4 °. When a cone is rotated by a controlled speed motor, its rotation is sinusoidal and the torque and angular displacement fluctuate as a sine function of time. The angular displacement corresponds to the shear strain described above, and the torque of the controlled speed motor (which causes the angular displacement) corresponds to the controlled shear stress described above.

* The gel preferably has a density greater than 1, more preferably greater than 1.1.

* The gel has a spontaneity (defined below) of less than 75, preferably less than 25.

Spontaneity is evaluated according to the following method.
Mix a mixture of 1 ml gel and 99 ml water with a 150 ml glass tube
m), cap tightly, and then turn over 180 ° (upside down). The number of times required to completely disperse the gel is called spontaneousness.

By the term continuous system is meant a material that is visually homogeneous, ie has the appearance of a single physical phase. This does not exclude the case in which these fine particles are dispersed, provided that they are solid particles small enough not to form a distinct distinct physical phase.

Gels are generally colloids and it is known that the dispersed layers therein combine with the continuous layers to produce a viscous, jelly-like product. Gels are also generally dispersions of high molecular weight compounds or agglomerates of small particles in very close association with a liquid.

To form a bag, the film needs to be molded (may be partially sealed) and then filled with gel. In general, gels have a high viscosity and thus are slow but flowable. The container used to contain the gel cannot be easily emptied due to the high viscosity of the gel, which is why gels are not used in agriculture to date. Once filled, the bag is typically heat sealed, although it must be sealed for final sealing.

The present invention will be specifically described by the following examples. However, this does not limit the scope of the present invention.

[0033]

Example 1 Two thin films are laminated to form a roll-shaped film. Both films are made from 88% hydrolyzed polyvinyl alcohol (soluble in cold water), each 25 microns thick. One contains 17% plasticizer and the other contains 15% plasticizer. The two films are laminated by heat (100 ° C.) and pressure into a 50 micron thick film.

This film is then used to make a 1 liter sachet containing a solvent-based liquid herbicide (a mixture of ioxynyl ester and bromoxynil ester) using the "mold and fill" method. To manufacture. The herbicide is a solution in a C10 aromatic hydrocarbon mixture as a solvent.

The film was placed on the machine with the plasticizer rich layer on the outside of the sachet. In this way, the film can be easily manufactured.

No leakage was observed during the manufacture, handling and shipping of the 500 sachets.

Example 2 Active ingredient: 2,4-D Phenoxybenzoic acid isooctyl ester: 64.8% Solvent: Aromatic solvent (flash point 65 ° C): 24.2% Surfactant: Nonionic / sulfonate blend emulsifier 4% Alkylbenzenesulfonic acid calcium salt 1% mixture Gelling agent: Dioctylsulfosuccinate and sodium benzoate mixture: 6% or more of the mixture is stirred at 50 ° C to form a gel.

The mixture is stirred and shaken until each component is dissolved or dispersed.

While stirring, it dissolved and then gelled. Gelation proceeded while cooling at room temperature (20 ° C).

The Brookfield viscosity of the gel is 3,000 centipoise. The stability of the emulsion was good in the tests described above.

1100 grams of this gel is filled almost completely (about 95 v / v%) in a 1 liter bag made from a PVA film similar to that of Example 1. Heat seal this bag. The density of the gel and the bag containing the gel are 1.1.

The bag was then dropped onto the ground 10 times from a height of 1.2 meters. No tears or leaks were seen.

Another bag made in the same manner as above is tested for pinhole protection. Needle (diameter 0.
6 mm) into the bag. It was found that small droplets formed where the needle stabbed, but the droplets were small and did not spill out of or flow along the bag.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor William Jiyeon Matsukassie United Kingdom, Essets C.M.5 OH D'Abriille, Onger, Huai Field Road, Research Station (no house number) (72) Inventor Leonard E. Hodakowski United States, North Carolina 27615, Raleigh, South Crestwick Court 8205 (72) Inventor Chiu Yuru Chien United States, North Carolina 27615, Laurie, White Teston Road 10004 (72) Inventor Samuel Tay Gorge, United States, North Carolina 27614, Rory, Park Ritz Way 170 8 (72) Inventor Paul The Ray Weaver United States, North Carolina 27713, Durham, Sentiyuri Oaks Road 3515-A

Claims (16)

[Claims] 1. A package comprising a water-soluble or water-dispersible laminated film containing a dangerous chemical dissolved or dispersed in a liquid or a gel. 2. The package according to claim 1, wherein the dangerous chemical is a pesticide, an insecticide, a plant protection agent or a plant growth regulator. 3. The package according to claim 1 or 2, wherein the dangerous chemical is dissolved or dispersed in a liquid. 4. The package according to claim 1 or 2, wherein the dangerous chemical is dissolved or dispersed in the gel. 5. Package according to any one of claims 1 to 4, characterized in that the laminated film has a thickness of 10 to 250 microns, preferably 15 to 80 microns. 6. The package according to claim 1, wherein the content of the dangerous chemical is 0.2 to 12 liters, preferably 0.45 to 6 liters. 7. The water-soluble or water-dispersible laminate film is insoluble in the liquid or gel used to dissolve or disperse the hazardous chemicals.
The package according to any one of 6 above. 8. At least one layer of the film is selected from polyethylene oxide, methylcellulose, or partially or fully alcoholysis or hydrolyzed polyvinyl acetate.
The package according to any one of 1. 9. At least one layer of said film comprises 40
Package according to claim 8, characterized in that it is -99%, preferably 70-92% alcoholysis or hydrolyzed polyvinyl acetate. 10. At least two layers of the laminate film are made of the same material.
The package according to any one of 9 above. 11. The laminate film of claim 1, wherein at least two layers are made of different materials.
10. The package according to any one of 9 to 10. 12. A package according to any one of claims 1 to 11, the laminate film is characterized in that it consists of two layers. 13. Package according to claim 12, characterized in that the thickness ratio of the two layers is between 0.1 and 10, preferably between 0.5 and 2. 14. The package according to any one of claims 4 to 13, wherein the gel has a viscosity of 500 to 50,000 centipoise, preferably 1,000 to 12,000 centipoise. 15. The gel has a phase difference (φ) between the controlled shear stress and the resulting shear strain such that tg (φ) is 1.5 or less, preferably 1.2 or less. The package according to any one of claims 4 to 14, which is characterized. 16. Package according to any one of claims 4 to 15, characterized in that the spontaneousness of the gel is less than 75, preferably less than 25.