Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/46—Applications of disintegrable, dissolvable or edible materials

Definitions

• This invention relates to a water soluble or water dispersible package containing an agrochemical, eg a pesticidal composition, and to a process for producing such a package.
• an agrochemical eg a pesticidal composition
• Agrochemicals include pesticides, e.g. herbicides, which are often potentially harmful materials and are commonly produced as a concentrated solution or dispersion in an organic liquid, as a gel or in solid form. Such chemicals are typically supplied in a metal or blow-moulded plastics container.
• chemical pesticides e.g. herbicides
• a quantity of the pesticide is measured out of the container in concentrated form and then mixed with a large volume of water before being sprayed onto a locus to be treated or onto plants.
• concentrated materials are frequently highly toxic so great care must be taken in measuring and mixing them to avoid spillage and to avoid human or animal contact with the concentrated pesticide.
• DE-A-1,287,502 discloses a package according to the preamble to claim 1
• the present invention provides a package containing an agrochemical, eg a pesticidal composition, which package comprises a first sheet of non-planar water soluble or water dispersible material and a second sheet of water soluble or water-dispersible material superposed on the first sheet and sealed to it by a single continuous closed water soluble or water dispersible heat seal not comprising any angular intersection with itself, the seal being along a continuous region of the superposed sheets.
• the continuous region of the superposed sheets is preferably substantially planar.
• the invention further provides a process for producing a package containing an agrochemical which package comprises a first sheet of non-planar water soluble or water dispersible material and a second sheet of water soluble or water dispersible material superposed on the first sheet and sealed to it by a single continuous closed water soluble or water dispersible heat seal, the seal being along a continuous region of the superposed sheets which process comprises:
• the agrochemical may be, for example, a plant protection agent, a plant growth regulator or a plant nutrient.
• a plant protection agent is a pesticide (such as an insecticide, fungicide, herbicide, acaricide or nematocide).
• the agrochemical composition may be in liquid form, or solid form, or gel form. It may comprise any conventional carrier or diluent or surfactant. Where the composition is in liquid form it may be in the form of a solution or of a dispersion in an organic liquid. e.g. an emulsion or a suspension. Similarly in gel form, the composition may contain pesticide either dissolved or dispersed in the substantially dry medium.
• the packages of the present invention generally contain from 0.1 grams to 7kg, preferably 1g to 5kg, where the composition is in solid form. Where the composition is in liquid or gel form, the package typically contains from 1ml to 10 litres, preferably from 0.5 to 5 litres (0.1 litres to 1.5 litres is especially preferred); on a smaller scale a range of 5ml to 1 litre is also useful.
• the package will contain at least a small amount of space, eg at least about 5% by volume, so as to minimise the likelihood of spillage of the composition during the production of the package.
• the package produced is evacuated of air or the contents are under reduced pressure.
• the package thus produced has a number of advantages, for example substantially increased resistance to shock.
• a powder or granules in such a package is compacted and is, effectively, skin-packaged within the film. Compaction of the product makes the package more likely to sink when dropped into water and the package occupies less space during storage.
• the advantages of packaging under reduced pressure include:
• the two sheets of water soluble or water dispersible material are of the same material, but they may be different.
• One sheet of the water soluble or water dispersible material may be easy to print upon.
• the water soluble or water dispersible material When the agrochemical composition is in liquid or gel form and comprises an organic solvent the water soluble or water dispersible material will be one which is insoluble in the organic solvent.
• Suitable water soluble or dispersible materials are polyethylene oxide and methyl cellulose. More preferably a polyvinyl alcohol (PVOH) film is used. Such a PVOH film may be a partially or fully alcoholised or hydrolysed e.g.40-99%, preferably 70-92% alcoholised or hydrolysed, polyvinyl acetate film. The film may be a cast film or, more preferably, a blown or extruded film.
• PVOH polyvinyl alcohol
• the polyvinyl alcohol film may be unoriented, mono-axially oriented or bi-axially oriented.
• Water soluble materials are preferred since they provide less disposal problems.
• the materials used will generally be cold water soluble; cold water soluble polyvinyl alcohol is preferred. It will be understood that other materials may be used when the package is to be dissolved or dispersed in water or hot water. Generally the water soluble or water dispersible material will be flexible.
• the maximum tensile strength of the material of the envelope is preferably at least 20, more preferably from 30 to 80, N/mm 2 and may be as much as 200N/mm 2 or more; and the elongation at break is preferably 200 to 380%, more preferably from 220 to 350% and may be as much as 500 per cent or more. Testing for these values is generally carried out at 23°C and 50% relative humidity.
• the water soluble or water dispersible material When the agrochemical composition is in liquid or gel form it is particularly important to avoid pinholes in the package through which leakage of the composition may occur.
• the water soluble or water dispersible material will typically be a laminate, generally of two layers of different or preferably the same water soluble or water dispersible material, as pinholes are unlikely to coincide in two layers of material.
• the laminates will consist of 2 layers of thickness from 20 ⁇ m to 1mm, preferably about 40 ⁇ m, each. Generally however the thickness of the layers will be kept to the minimum needed to prevent rupture of the package, so that the water soluble or dispersible material is dissolved or dispersed as quickly as possible and the pesticide then released.
• the sheets of water soluble or water dispersible material typically comprise a single layer of material.
• the material will generally be from 20 to 500 ⁇ m, preferably 30 to 100 ⁇ m, thick.
• a laminate material of the type described above may be used.
• the thickness of the water soluble dispersible material will generally be kept to a minimum in packages containing solid compositions.
• the thickness of the first sheet will generally not be less than 20 ⁇ and (to maintain ease of processing) generally not more than 1 mm.
• a preferred range is from 80-400 ⁇ , eg 100-400 ⁇ , most preferably about 250 ⁇ .
• the thickness of the second sheet may be less than that of the first sheet as the second sheet will not generally be thermoformed so that localised thinning of the sheet will not occur.
• the thickness of the second sheet will generally not be less than 10 ⁇ , preferably not less than 20 ⁇ .
• the film will generally not be more than 1 mm thick, a preferred range being from 20 ⁇ to 250 ⁇ , most preferably about 150 ⁇ .
• the package is provided with a region which will more readily dissolve in water than the rest of the package.
• This offers advantages, for example by speeding up the dispersion of the agrochemical contained in the package.
• the region may be provided for example by making one sheet of the water-soluble or water dispersible material thinner than the other, or by making one portion of the package thinner than the rest.
• the package does not possess a seam running down the centre of one of the faces of the package. This offers advantages over known packages, for example by reducing the likelihood of failure occurring in the package when it is subjected to shock, because packages having a seam running down the centre of one of the faces of the packages necessarily have a point at which two or more seals intersect which will be more likely to fail under shock than the equivalent package not having this point of intersection.
• the two water soluble or water dispersible sheets in the packages are sealed together by a closed continuous heat seal.
• the seal is water soluble and does not suffer from leakage, it is a single continuous seal and has no geometrical discontinuities, i.e. it does not comprise any angular intersections with itself. Therefore the heat seal will usually be curved, at least in portions, for instance at the corners of the package: the radius of curvature of the heat seal will generally not be less than 1mm, preferably not less than 5mm, and not more than half the width of the package.
• Suitable pesticides which may be used in the package of the present invention include fungicides, insecticides and herbicides (for example hydroxybenzonitrile herbicides, e.g. bromoxynil or ioxynil or derivatives thereof such as salts or esters, e.g. heptanoates or octanoates).
• Molluscicides suitable for addition to, for example, ponds or streams may also be employed.
• Agrochemicals which can be used in the invention include:
• petroleum based solvents e.g. petroleum ethers, mineral oils, aliphatic or aromatic hydrocarbons, e.g. hexane, octane, cyclohexane, benzene, xylene and naphthalene, halogenated aliphatic or aromatic hydrocarbons, e.g. carbon tet
• cyclohexanone 1-methyl-2-pyrrolidinone (NMP), ethers, or a higher alcohol (lower alcohols may migrate through the water soluble or water dispersible materials described above: this can result in product appearing on the outside of the envelope).
• NMP 1-methyl-2-pyrrolidinone
• mixtures of solvents e.g. mixtures of a hydrocarbon solvent with another solvent such as a ketone or a higher alcohol, may also be used.
• the organic liquid must be reasonably dry and typically contains less than 2 to 3% of water to ensure that it does not leak prematurely from the package.
• compositions may comprise, in addition to, or in some cases instead of, an organic solvent as a carrier or diluent, a surfactant, which is reasonably dry in that it contains less than 2 to 3% water.
• a surfactant may be of the ionic or non-ionic types: for example sulphoricinoleates, quaternary ammonium derivatives, products based on condensates of ethylene oxide with alkyl and polyaryl phenols, e.g.
• nonyl- or octyl-phenols or carboxylic acid esters of anhydrosorbitols which have been rendered soluble by etherification of the free hydroxy groups by condensation with ethylene oxide, alkali and alkaline earth metal salts of sulphuric acid esters and sulphonic acids such as dinonyl- and dioctyl-sodium sulphonosuccinates and alkali and alkaline earth metal salts of high molecular weight sulphonic acid derivatives such as sodium and calcium lignosulphonates and sodium and calcium alkylbenzene sulphonates, and block ethylene oxide/propylene oxide copolymers.
• alkali and alkaline earth metal salts of sulphuric acid esters and sulphonic acids such as dinonyl- and dioctyl-sodium sulphonosuccinates and alkali and alkaline earth metal salts of high molecular weight sulphonic acid derivatives such
• the agrochemical composition may comprise up to 10%, e.g. from 0.05% to 10% of surfactant but, if desired, it may comprise higher proportions of surfactant for example up to 15% in liquid emulsifiable suspension concentrates and up to 25% in water soluble concentrates.
• the contents of the package may be thickened or rendered thixotropic to provide a gel.
• An increased viscosity in the contents can reduce the likelihood of rupture if the package is subjected to mechanical shock.
• the contents of the package may be rendered more viscous or thixotropic by the inclusion of additives, for example, a modified organophile, or bentonite, lecithin, polymethylene oxide or silica gel.
• concentrations of agrochemical dissolved or dispersed in the organic liquid or in the gel will generally be those conventionally used: in order to reduce the bulk of each package, however, concentrations may be increased.
• Each package will preferably contain 100ml to 1.5 litres, preferably at least about 500 ml and will preferably contain a convenient standard volume, for example 500 ml or 1 litre, although it will be appreciated that any convenient standard volume may be chosen.
• the agrochemical composition when in solid form then it may comprise any conventional carrier or diluent which is reasonably dry, in that it contains less than 2 to 3% of moisture.
• suitable solid diluents or carriers are aluminium silicate, talc, calcined magnesia, kieselguhr, tricalcium phosphate, powdered cork, adsorbent carbon black and clays such as kaolin and bentonite.
• Solid compositions may comprise surfactants, such as dispersing agents, for example those surfactants previously mentioned. In some cases such surfactants may also be used as diluents or carriers.
• concentrations in the solid agrochemical compositions may be as conventionally used: concentrations may however be increased to reduce the bulk of the package.
• the agrochemical compositions used in the package of the present invention may be prepared by conventional means.
• the packages of the present invention may be inside an additional outer container.
• a container may provide additional strength and if water resistant may serve to protect the package of the present invention from accidental exposure to water.
• the outer container is preferably sealed to avoid exposing the package of the present invention to undue moisture.
• the package of the present invention may comprise more than one compartment containing the same or different agrochemical compositions.
• Such multi-compartment packages are particularly useful where a combination of components are to be employed together and where the components are incompatible for a prolonged period, for instance if they react chemically.
• the packages according to the invention should release their contents in less than about 10 minutes.
• the packages will be placed in the spray tank of a conventional sprayer.
• the tank will generally be partly filled with water, and the package added.
• the tank is provided with means to agitate the water the contents of the bag will be released more rapidly. It is preferred that release should take place in less than about a minute, for example in 30 to 40 seconds. It will be understood that the time taken to release the pesticide will depend upon a number of factors apart from the nature of the bag, including the temperature of the water and the level of agitation.
• the packages of the present invention may be obtained by first deforming a sheet of water soluble or dispersible material so as to form a recess adapted to retain a agrochemical composition. This may be achieved for example by vacuum forming where the sheet is deformed to conform to the shape of a suitable mould and may, if desired, be a thermoforming process to cause the sheet to retain its shape after release from the mould.
• the mould may be equipped with pinholes through which the space between the mould and the sheet can be evacuated.
• the sheet may be driven against the mould by vacuum forming, or by applying a superatmospheric pressure to the other side of the sheet (this may be effected using an operating pressure of, for example 41 ⁇ 2 to 6 bar) or by mechanical displacement of the sheet (plug forming).
• Thermoforming will generally be carried out using a temperature not less than 40°C and not more than 110°C. A temperature from 70-110°C is preferred, most preferably about 90°C.
• the agrochemical composition is placed in the recess formed by the deformation, and a second substantially planar sheet of water soluble or water dispersible material is then placed across the recess.
• the two sheets of water soluble or water dispersible material are then heat sealed so as to form a continuous closed heat seal.
• the width of the heat seal itself is preferably 1-10 mm, preferably about 5 mm.
• the dwell time for heat sealing will depend upon, for example, the material used, its thickness and the heat seal temperature. A dwell time of about 3 seconds is generally suitable when the thickness of the material is about 80 ⁇ . A sealed compartment is thus formed.
• the heat sealing is generally carried out at 15 to 25°C and 15 to 85% relative humidity (RH).
• the relative humidity is preferably 35 to 55%.
• Some routine experimentation may be required to obtain a suitable heat seal depending on the package material, e.g. the particular grade and thickness of PVOH chosen.
• the quality of the seal can be checked, for example by visual inspection for areas of opacity or for bubbles. Imperfections in the seal may give rise to a lack of water solubility or water dispersibility of the seal.
• the heat sealing process can be carried out on conventional heat sealing equipment which permits control variation of the sealing jaw temperature, jaw pressure and dwell time.
• a first sheet of polyvinyl alcohol (Vinex 2144: thickness 225 ⁇ ) is heated at 90°C and then thermoformed into a mould, the draw depth being 80 mm, with a forming time of 6 seconds.
• the product to be packaged is placed in the recess thus formed.
• a second sheet of polyvinyl alcohol (Solublon KA40/KA40, a laminate of two layers each of 40 ⁇ thickness: total thickness 80 ⁇ ) is placed across the recess thus formed and heat sealed using a sealing temperature of 180°C with a dwell time of 8 seconds.
• the operating air pressure of the thermoforming apparatus is 4.5 bar.
• the tensile strength of the seal in the water-soluble bags thus produced is 32.4 N (mean).
• the production of the water-soluble bags is carried out at 21°C (room temperature) and a relative humidity of 38%.
• a first sheet of polyvinyl alcohol (Vinex 2144: thickness 225 ⁇ ) is heated at 90°C and then thermoformed into a mould, the draw depth being 80 mm, with a forming time of 6 seconds.
• the product to be packaged is placed in the recess thus formed.
• a second sheet of polyvinyl alcohol (Vinex 2144: thickness 75 ⁇ ) is placed across the recess thus formed and heat sealed using a sealing temperature of 200°C with a dwell time of 6 seconds.
• the operating air pressure of the thermoforming apparatus is 4.5 bar.
• the tensile strength of the seal in the water-soluble bags thus produced is 28.7 N (mean).
• the production of the water-soluble bags is carried out at 21°C (room temperature) and a relative humidity of 38%.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Wrappers (AREA)
• Packages (AREA)
• Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
• Cultivation Of Plants (AREA)
• Catching Or Destruction (AREA)
• Laminated Bodies (AREA)

Priority Applications (2)

Applications Claiming Priority (5)

Related Child Applications (1)

Publications (2)

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ID=26298687

Family Applications (2)

Family Applications Before (1)

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• 1992
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  • 1992-04-03 PT PT100349A patent/PT100349A/pt not_active Application Discontinuation
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• 1993
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• 1997
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• 2001
  • 2001-07-23 JP JP2001221715A patent/JP2002128138A/ja active Pending
• 2003
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