OA10559A - Packaging containing hazardous chemicals and process for their production - Google Patents

Abstract

The invention provides a package which comprises a hazardous chemical dissolved or dispersed in a liquid or gel contained in a water-soluble or water-dispersible laminated film bag, sachet or container. The chemical comprises an agrochemical such as a pesticide, herbicide.

Description

1 010559

The present invention relates to a package comprising a liquid chemical substance or a chemical substance dissolved or dispersed in a liquid or a gel which is placed in an envelope of a water soluble or dispersible material in water.

Currently, most hazardous liquids are stored in metal drums or, when smaller quantities are required, in plastic containers.

Hazardous compounds, especially agrochemicals, are formulated in various ways. However, it is particularly advantageous for the cultivators to handle these compounds when in the liquid state. This facilitates the spreading of these compounds. The handling of liquids, however, presents difficulties and disadvantages. The liquids may be spilled on the floor or may escape due to the presence in the containers. The containers may also break when subjected to a physical shock.

Thus, it is difficult to design a container that is suitable for the farmer, that is safe for all those handling the containers and that is also environmentally safe.

It is known that the agrochemical compounds can be packaged in soluble bags or sachets produced 010559

These can be cracked by the irochemical elements they contain. In fact, there is a need to be present in movies, the reality of movies and a potential source of leaks. * 4 tt 4 d "" particles of dust or other foreign bodies, <l "'n gel particles or thin spots present on. • to ilanrs I film are all weak points poten-H If a film with such a weak point is subjected to a number of manipulations or physical shocks, the film may break at this point, which poses a problem in the agrochemicals industry. in which the containers may be subjected to rough or haphazard manipulation by distributors or farmers.

The weaknesses of the films mentioned above exist to a greater or lesser degree in certain types of films, according to their production processes. When films are produced by casting, there may be fewer perforations, but small particles of gel inclusions are more frequently present. When films are produced by extrusion, there is a greater number of perforations.

It is an object of the present invention to provide a novel carrier for agrochemical compounds which is safe to handle.

It is another object of the present invention to provide a novel container for agrochemical compounds which is convenient for end-users, for example farmers.

Another object of the present invention is to provide a novel container for agrochemical compounds which reduces the risk of pollution and environmental damage. 35 3 010559

In one aspect, the present invention seeks to prevent leakage of liquid or liquid chemicals through the perforations of a container produced from a film. Although perforations are generally rare, the presence of a single perforation in several thousand containers is sufficient to cause damage since the liquid in the container passes through the perforation and contaminates the surrounding environment. Other objects and advantages of the present invention will become apparent from the following description.

The container of the present invention is character-ized by the packaging of a dangerous substance, in the form of liquid or gel, in a water-soluble or dispersible water bag consisting of a laminated film.

According to a preferred characteristic of the present invention, the hazardous compounds are agrochemical compounds, for example pesticides or plant protection agents or plant growth regulators.

Accordingly, the present invention provides a package which comprises a hazardous chemical dissolved or dispersed in a liquid or gel placed in a container of a water-soluble or water-dispersible laminated film.

As used herein, the term "laminated film" refers to a film that has been produced from two or more initially distinct layers, which are joined together. The layers may be joined to each other in the laminate by known methods. For example, the layers of the laminate can be joined by compression, heating, cross-linking, melting, adhesion or any combination of these operations. It is possible to achieve the adhesion of the layers by the use of a separate adhesive or, where appropriate, water. 4 010559

When suitable water-soluble or water-dispersible layers are used, a particularly convenient means for obtaining a laminated film is adhesion of the discrete layers by means of an adhesive polyvinyl alcohol (PVA) (generally of low molecular weight) and or, more simply, by means of water.

Since two or more layers are used to produce the laminated film, the probability of occurrence of perforations in the film is reduced to a value practically equal to zero. This is because it is unlikely that two perforations present in distinct layers overlap. In addition, the tensile strength of a multilayer (eg two-layer) film is greater than the tensile strength of a similar film of the same thickness, which consists of a single layer.

The laminated films that are used in the present invention generally have a thickness of 10 to 250 microns, preferably 15 to 80 microns. The different layers constituting the laminated films which are used in the present invention generally have each of the thicknesses equal to half of these values. When two layers are used, the ratio of the thicknesses of the two layers is generally from 0.1 to 10, Preferably, the bags or pouches produced from laminated films in accordance with the present invention generally have a capacity of 0.2 to 12 liters, preferably 0.45 to 6 liters.

The materials which can be used in the present invention are water-soluble or water-dispersible materials which are insoluble in the organic solvents used for the dissolution or dispersion of the chemical substances which they are intended to contain. Suitable materials include polyethylene oxide or methylcellulose, but preferably the material is polyvinyl alcohol or is produced from polyvinyl alcohol, i.e., polyvinyl acetate films. having undergone partial or total alcoholysis or hydrolysis, for example an alcoholysis or a hydrolysis of 40 to 99%, preferably 70 to 92%.

The layers of the laminated films of the present invention may be of the same or different materials. Films produced from layers made of different materials may have advantageous properties. For example, an inner layer of a package can be made more resistant to the agrochemical compound it contains. In addition, the outer layer of the bag may be selected to have one or more of the following properties: I. faster dissolution (as compared to an inner layer or single-layer packaging) in water, II. improved mechanical properties, including improved strength, to mechanical damage, III. improved workability, IV. a lower sensitivity to relative humidity, V. resistance to freezing and / or high temperatures.

One or more of the layers of the laminated film may contain a plasticizer. A suitable amount of plasticizer in the inner layer can improve the sealing properties of the film and render the film less susceptible to stretching. Thus, the film will be easier to deal with machines and seal to form a container containing the hazardous liquid. A suitable amount of plasticizer in the outer layer of the container makes the outer surface more flexible and thus more resistant to physical damage caused by low temperature or shock and displacement.

The layers of the laminated film can be produced by various techniques, e.g.extrusion or casting. A laminate produced from layers formed by different processes may have advantageous properties, including greater flexibility, increased strength, and greater resistance to stretching. The increased strength and / or resistance to stretching may exist in a film direction. The laminated films for use in the present invention are used to produce packaging which avoids time and dangerous consequences caused by prior art packages leaking during the filling operation or during a period of time. subsequent manipulation because of defects in the films.

As mentioned above, the bags (or other means of packaging) may contain liquids or gels. A preferred feature of the present invention is the bags or packaging means of the present invention containing a gel.

In accordance with a particular feature of the present invention, the gels are selected so that one or more of the following characteristics are present; the resulting gels form a continuous medium, and / or the resulting gels have a viscosity of 500 to 50,000 mPa. Preferably, from 1000 to 12,000 mPa.s (these viscosities are Brookfiel viscosities measured at room temperature by means of a viscometer in the form of a planet plate at 20 revolutions per minute), the gai has a difference in phase. between the controlled shear stress and the resulting shear deformation such that tg (phi) is less than or equal to 1.5, preferably less than or equal to 1.2. Tg (phi) is latangent of the angle phi (or phase difference.) The measurement of phi 7 010559 is carried out at ambient temperature by means of a rheometer comprising a fixed flat plate and a rotating cone above this plate. so that the angle between these two elements is less than 10 °, preferably 4 ° · The cone is rotated by means of a speed-controlled motor, the rotation is a sinusoidal rotation, which means that the torsion moment and the angular displacement varies with a sinusoidal function over time * The angular displacement corresponds to the predicted shear deformation, the torque of the controlled speed motor (which causes the angular displacement) corresponds to the controlled shearing tension mentioned above, * the gels advantageously have a density greater than 1, preferably greater than 1.1, the gels possess a spontaneity (as defined in FIG. i-after) less than 75, preferably less than 25.

Spontaneity is evaluated according to the following procedure. A mixture of 1 ml of gel and 99 ml of water is introduced into a 150 ml and 22 mm diameter glass tube which is opened and turned 180 ° (upper part facing downwards). ) ·

The number of inversions required to completely disperse at room temperature the gel is referred to by the name of spontaneity. The term "continuous medium" refers to a substance that is visually homogeneous, that is to say which has the visual appearance of having a single physical phase, this does not exclude the possibility that it is there small dispersed solid particles, provided that these particles are sufficiently small so as not to constitute a distinct visible physical phase.

It is known that a gel is generally a colloid in which the dispersed phase has combined with the continuous phase to give a viscous product similar to a gelatin; it is also a dispersion typically consisting of a high molecular weight compound or an aggregate of small particles in very close association with a liquid.

In order to produce a bag, it is necessary that the film be shaped (possibly partially welded), and then filled with the gel. In general, the gels are flowable, even if it is a vitesselent flow due to the high viscosity. A container that is used to hold the gels can not be easily emptied for this high viscosity of the gels (this is a reason why gels have not been used in agriculture so far). Once filled, the bag must be final welded, usually heat-welded, for its closure.

The following examples are provided for illustration purposes and should not be construed as limiting the scope of the present invention. EXAMPLE 1

A film in the form of a roll is produced by laminating from two thinner films: the two films consist of a polyvinyl alcohol, produced by hydrolysis at 88% (soluble in cold water), each of these films having a thickness of 25 micrometers ; one has a plasticizer content of 17%, the other has a plasticizer content of 15%. The two films are sonicated to each other by heating (100% C) and underpressure to form a film of 50 microns thick.

This film is then used to produce 1-liter sachets containing a solvent-based liquid herbicide (mixture of ioxynyl and bromoxynyl esters) by means of "shaping and filling" processes. The herbicide is a solution in a mixture of C10 aromatic hydrocarbons as a solvent.

The film is placed on the machine so that the high plasticizer layer is produced on the outer side of the bags. The film is thus easy to process. 010559 9

No leakage is observed during the production, handling and transport of 500 bags. EXAMPLE 2

A gel is prepared by stirring at 50 ° C. with a mixture of: an active ingredient: isooctyl ester of 2,4-D-phenoxybenzoic acid: 64.8% of a solvent: an aromatic solvent having a flash point of 65 ° C: 24.2% of a surfactant: a mixture of an emulsifier consisting of a non-ionic emulsifier / suifonate mixture: 4% and a calcium alkylbenzene sulfonate: 1% of a gelling agent: a mixture of a dioctyl sulphosuccinate and sodium benzoate: 6%

The mixture is subjected to mechanical stirring and shaking until all components are dissolved or dispersed.

During the mechanical stirring, dissolution occurs and then gelation. Gelling is increased during cooling at room temperature (20 ° C).

The Brookfield viscosity of the gel is 3000 mPa.s. The stability of the emulsion is good in the above test. 1100 g of this gel are introduced into a 1 liter bag made of a polyvinyl alcohol film similar to the film of Example 1. The bag, which is almost full (about 95% v / v), is heat-welded. The densities of the gel of the bag containing the gel are equal to 1.1.

Then drop the bag 10 times on the ground, from a height of 1.2 m. No breaks or leaks are observed. 010559 10

Another bag produced in the same way as the previous bag is tested to determine protection against perforation. A needle (diameter: 0.6 mm) was passed through the bag. The formation of a small droplet is observed at the point where the needle was passed, but this droplet is small enough not to fall out of the bag and not to flow along the bag.

It goes without saying that the present invention has been described only for explanatory purposes, but in no way limiting, and that many modifications can be made without departing from its scope.

Claims (19)

010559 11 CLAIMS 1. Packaging, characterized in that it comprises a dangerous chemical substance dissolved or dispersed in a liquid or a gel placed in a container made of a water-soluble or dispersible laminated film in water. 2. Packaging according to claim 1, characterized in that the hazardous chemical substance is an agrochemical compound, a pesticide, a plant protection agent or a plant growth regulator. 3. Packaging according to claim 1 or 2, characterized in that the dangerous chemical substance is dissolved or dispersed in a liquid. 4. Packaging according to claim 1 or 2, characterized in that the dangerous chemical substance is dissolved or dispersed in a gel. 5. Packaging according to any one of the preceding claims, characterized in that the coated film has a thickness of 10 to 250 micrometers, preferably 15 to 80 micrometers. 6. Packaging according to any one of the preceding claims, characterized in that it has a dangerous chemical substance capacity of 0.2 to 12litres, preferably 0.45 to 6 liters. 7. Packaging according to any one of the preceding claims, characterized in that the water-soluble or water-dispersible layered film is insoluble in the liquid or gel used for the dissolution or dispersion of the dangerous chemical substance. 8. Packaging according to any preceding claim, characterized in thatat least one of the layers of the film is selected between polyethylene oxide, methylcellulose or polyvinyleagent acetate undergone an alcoholysis or partial hydrolysis or 1210 total. 9. Packaging according to claim 8, characterized in that said layer consists of polyvinyl acetate having undergone an alcoholysis or a hydrolysis of 40 5 to 99%, preferably 70 to 92%. 10. Packaging according to any one of the preceding claims, characterized in that at leasttwo layers of the laminated film consist of the same material. 11. Packaging according to any one of claims 1 to 9, characterized in that at least two layers of the laminated film consist of different materials. 12. Packaging according to any one of the preceding claims, characterized in that the laminated film consists essentially of two layers. 13. Packaging according to claim 12, characterized in that the ratio of the thicknesses of the two layers is a ratio of 0.1 to 10, preferably 0.5 to 2. 14. Packaging according to any one of claims 4 to 13, characterized in that the gel has a viscosity of 500 to 50,000 mPa.s, preferably from 1000 to 12 000 mPa.s. 15. Packaging according to any one of claims 4 to 14, characterized in that the gel has a phase difference (phi) between the controlled shear stress and the resulting shear deformation and that the tangent (phi) is lower or equal to 1.5, preferably less than or equal to 1.2. 16. Packaging according to any one of claims 4 to 15, characterized in that the gel has spontaneity (as defined) less than 75, preferably less than 25. 17. Process for the production of a packaging according to any one of the preceding claims, characterized in that it consists in laminating two or more layers to one another by compression, heating, crosslinking, melting or else medium of water to obtain the laminated film. 18.Conditioning according to claim 1, characterized in that it essentially meets the description-tion above. 19. The method of claim 17, character-ized in that it essentially meets the description 10 above