JPH04225903A - Soluble sash - Google Patents

Abstract

PURPOSE: To provide a new type of container system for agrochemicals that is easy to handle for the final user (farmer). CONSTITUTION: An agrochemical that is dissolved or dispersed in liquid or gel is contained in a water-soluble or water-dispersing laminating film (for example, a laminating film having at least one layer of polyethylene oxide, methyl cellulose or poly(vinyl alcohol) to prepare the objective packaging product.

Description

[Detailed description of the invention]

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

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

Hazardous compounds, particularly pesticide compounds, are formulated in a variety of ways. However, it is particularly desirable for farmers to have the compound in liquid form for handling reasons. This is because liquid compounds are easy to disperse. However, handling of liquids is difficult and has drawbacks. A hole in the container may allow liquid to spill or leak onto the ground. The container may even break due to physical impact.

It is thus difficult to devise a container system that is suitable for farmers, safe in terms of container handling, and safe for the environment.

It is known that pesticides can be contained in dissolvable bags or sachets made from films. However, the film can break or tear, allowing the contained pesticide to spill out. In fact, various imperfections in the film can lead to weak points in the film and, as a result, potential sources of leakage. Air bubbles, dust particles or other foreign objects, gel particles or thin areas on or within the film are all potential weak points. If a film with such a weak point is used repeatedly or subjected to physical impact, the film will tear at the weak point. This is a particular problem in the agrochemical industry where containers are handled roughly and without regard to safety by distributors or farmers.

[0006] The above-mentioned film weaknesses are more or less present in a particular type of film depending on the manufacturing method. When making a film by casting,
Although there are few pinholes, there are often many tiny pieces of gel inclusions. When films are made by extrusion, there are many pinholes.

An object of the present invention is to provide a new container system for agricultural chemicals that is safe to handle.

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

A further object of the invention is to provide a new container system for pesticides which reduces the risk of contamination 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. Although pinholes are generally rare, just one pinhole in thousands of containers can cause significant damage. This is because the liquid in the container will pass through the pinhole and contaminate the surrounding environment.

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

The container system of the invention is characterized in that the hazardous 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, for example an insecticide or a plant protection agent or a plant growth regulator.

Accordingly, the present invention provides a package comprising a water-soluble or water-dispersible laminate film containing a dangerous drug dissolved or dispersed in a liquid or gel.

[0015] As used herein, the term laminate film refers to a film made by bonding two or more originally separate layers. The layers are joined together to form a laminate using known methods. For example, layers or laminates may be joined using pressure, heat, crosslinking, melting, gluing, or a combination thereof. The layers can also be adhered using another adhesive or preferably water.

If a suitable water-soluble or water-dispersible layer is used, a particularly convenient method of making the laminate film is to use adhesive PVA (generally low molecular weight) and/or, more conveniently, by water. It is the gluing of separate layers.

[0017] Since more than one layer is used to produce the laminate film, the rate of pinhole formation in the film is reduced to almost zero. This is because even if there are two pinholes in different layers, there is no possibility that they will overlap. Furthermore, the tensile strength of multilayer (eg bilayer) films is better than that of similar films of the same thickness made from a single layer.

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

Materials that may 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 drug. Suitable materials include polyethylene oxide or methylcellulose, but the material may consist of or be derived from polyvinyl alcohol, i.e. partially or completely (e.g. 40-99%, preferably 70-92%) alcoholic. Preferred is a lysed or hydrolyzed polyvinyl acetate film.

The layers of the laminate film of the invention may be made from the same material or from different materials. Films made from layers of different materials can have beneficial properties. For example, the inner layer of the package may be made more resistant to the pesticides it contains. Additionally, the outer layer of the bag may be selected to have one or more of the following properties: i. faster dissolution (compared to inner layer or single layer packaging); ii. having improved mechanical properties, including improved resistance to mechanical damage; iii. having improved machinability; iv. less sensitive to relative humidity, v. Must be resistant to freezing and/or high temperatures.

A plasticizer may be included 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 prone to stretching. This allows the film to be more easily machined and sealed around hazardous 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 movement due to low temperatures or impact.

[0022] The layers of the laminate film can be made using a variety of methods, such as extrusion or casting. Laminates made from layers produced by different methods can have beneficial properties including greater flexibility, higher strength, and greater resistance to stretching. High strength and/or improved resistance to stretching is present in one direction of the film. The laminated film used in the present invention can be used to produce packages that prevent the time-consuming and dangerous consequences of traditional packages where defects in the film result in leaks during the encapsulation or subsequent handling steps. Ru.

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

According to a preferred feature of the invention, the gel is selected to have one or more of the following characteristics:*
The resulting gel forms a continuous system, * The resulting gel has a viscosity of 500 to 50,000 centipoise, more preferably 1000 to 12,000 centipoise.
These viscosities are Brookfield viscosities measured at room temperature using a flat 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 tg(φ) is 1.5 or less, preferably 1.2 or less. Tg(
φ) is the tangent of the angle φ (phase difference). φ is measured at room temperature by a rheometer with a fixed plate and a rotating cone on this plate, the angle between the plate and the cone being e.g.
It is less than 0°, preferably less than 4°. When the cone is rotated by a controlled speed motor, its rotation is sinusoidal, and the torque and angular displacement vary as a sinusoidal 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 of more than 1,
More preferably it has a density greater than 1.1.

*The gel has a molecular weight of less than 75, preferably 25
spontaneity (defined below) of less than or equal to

Spontaneity is evaluated according to the following method. A mixture of 1 ml of gel and 99 ml of water is placed in a 150 ml glass tube (diameter 22 mm), the tube is tightly stoppered, and the tube is inverted 180° (upside down). The number of times required to completely disperse the gel is referred to as spontaneity.

The term continuous system refers to a visually homogeneous material, ie, a material that has the appearance of a single physical phase. This does not exclude the case where solid particles are dispersed so long as they are small enough not to constitute an appreciably separate physical phase.

It is known that gels are generally colloids in which a dispersed layer combines with a continuous layer to produce a viscous jelly-like product. Gels are also generally dispersions of high molecular weight compounds or aggregates of small particles in very intimate association with a liquid.

[0031] To form the bag, the film must be formed (possibly partially sealed) and then filled with gel. Generally, gels have a high viscosity and therefore can flow at a slow rate. The containers used to house the gel cannot be easily emptied due to the high viscosity of the gel (which is why to this day it is not used in agriculture). Once filled, the bag must be sealed for final sealing, which is typically heat sealed.

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

[0033]

[Example] Example 1 A roll-shaped film is produced by laminating two thin films. Both films are each made from 88% hydrolyzed polyvinyl alcohol (soluble in cold water), 25 microns thick. One sheet contains an amount of plasticizer of 17%, the other one of an amount of 15%. The two films are laminated by heat (100°C) and pressure into a single film 50 microns thick.

This film was then used to form 1 liter sachets containing a solvent-based liquid herbicide (mixture of ioxynyl ester and bromoxynyl ester) using a "form and fill" method. Manufacture. The herbicide is a solution in a C10 aromatic hydrocarbon mixture as solvent.

The film was placed in the machine with the plasticizer rich layer on the outside of the sachet. Films can be easily produced in this way.

No leakage was observed during 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: Emulsifier for non-ionic/sulfonate blends
4%
Alkylbenzenesulfonic acid calcium salt
1% mixture Gelling agent: mixture of dioctyl sulfosuccinate and sodium benzoate: 6% or more mixture
A gel is prepared by stirring at 0°C.

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

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

The Brookfield viscosity of the gel is 3,00
It is 0 centipoise. The stability of the emulsion was good in the tests described above.

1100 grams of this gel are placed almost full (approximately 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 density of the bag containing the gel are 1.1.

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

Another bag made in a manner similar to that described above is tested for pinhole protection. Needle (diameter 0
．． 6mm) into the bag. A small droplet formed at the needle puncture site, but it was found that this droplet was small and did not spill out of or flow along the bag.

Claims (19)

[Claims] 1. A package comprising a water-soluble or water-dispersible laminate film containing a dangerous drug dissolved or dispersed in a liquid or gel. [Claim 2] Claim 1, wherein the dangerous drug is an agricultural chemical, an insecticide, a plant protection agent, or a plant growth regulator.
The packaging described in. 3. The package according to claim 1, wherein the dangerous drug is dissolved or dispersed in the liquid. 4. The package according to claim 1, wherein the dangerous drug is dissolved or dispersed in the gel. 5. Packaging according to claim 1, characterized in that the laminated film has a thickness of 10 to 250 microns, preferably 15 to 80 microns. 6. Package according to claim 1, characterized in that the content of hazardous chemicals is between 0.2 and 12 liters, preferably between 0.45 and 6 liters. 7. Claim 1, characterized in that the water-soluble or water-dispersible laminate film is insoluble in the liquid or gel used to dissolve or disperse the hazardous chemical.
The package according to any one of items 1 to 6. 8. At least one layer of the film is selected from polyethylene oxide, methylcellulose, or partially or completely alcoholized or hydrolyzed polyvinyl acetate.
7. The package according to any one of Item 7. 9. At least one layer of the film comprises 4
Packaging according to claim 8, characterized in that it is 0-99%, preferably 70-92% alcoholyzed or hydrolyzed polyvinyl acetate. Claim 10: At least two of the laminate films.
Claim 1 characterized in that the layers are made of the same material.
10. The package according to any one of 1 to 9. Claim 11: At least two of the laminate films.
Packaging according to any one of the preceding claims, characterized in that the layers are made of different materials. 12. Any one of claims 1 to 11, characterized in that the laminate film essentially consists of two layers.
Packages listed in section. 13. Claim 12, characterized in that the ratio of the thicknesses of the two layers is from 0.1 to 10, preferably from 0.5 to 2.
The packaging described in. Claim 14: The viscosity of the gel is 500 to 50,000.
Packaging according to any one of claims 4 to 13, characterized in that it is centipoise, preferably from 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, characterized in that: 16. Packaging according to claim 4, characterized in that the spontaneity of the gel is less than 75, preferably less than 25. Claim 17: To obtain a laminated film,
17. The method for producing a package according to claim 1, comprising laminating two or more layers by pressure, heating, crosslinking, melting, or water. 18. A package according to claim 1 substantially as hereinafter described. 19. The method of claim 17 substantially as hereinafter described.