Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
  • A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
  • A01G9/14—Greenhouses
  • A01G9/1438—Covering materials therefor; Materials for protective coverings used for soil and plants, e.g. films, canopies, tunnels or cloches
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
  • Y02A40/10—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in agriculture
  • Y02A40/25—Greenhouse technology, e.g. cooling systems therefor

Definitions

• the present invention relates to a method of coating polymeric sheets or films and glass which enables the substrate to convert any incident light radiation in the UV region to visible light on transmission therethrough thus making it suitable for enhancing growth and as protective coverings for growing plants.
• polymeric materials such as polyvinyl chloride (PVC) or polyethylene may be treated with substances such as scintillators which alter certain of the wave lengths or the light transmitted by the material.
• PVC polyvinyl chloride
• scintillators which alter certain of the wave lengths or the light transmitted by the material.
• the overall effect is to increase the total visible component of the transmitted light.
• Films containing such scintillators find particular application in covering or glazing materials for greenhouses or cloches, whereby its use forces growth of plants, e.g. fruit or vegetables placed under it.
• the polymeric material may be treated by direct compounding of the substance in the polymer composition to produce the sheet or film.
• the wavelength shifting characteristics of the treated polymer is not permanent and decays with time, e.g. over a period of several months.
• the short life of the active substance necessitates the replacement of the inactive sheet or film with a fresh sheet or film for continuity of effectiveness. This is however a very expensive method even for substances which maintain their activity as long as the plant mrowing season lasts.
• the present invention is a method of improving the transmissibility of polymer substrates as hereinafter defined to visible light comprising coating the polymer substrate with an aqueous emulsion or dispersion containing an ultraviolet-absorbing scintillator, which is capable of drying in air at ambient temperatures to produce a transparent film coating.
• polymer substrates as used here and used throughout the specification applies to all physical forms of polymeric material including glass, which are transparent or translucent to visible and/or ultraviolet light and is particularly applicable to sheets or films of such polymeric material.
• any of the conventional UV absorbing scintillators may be used, the only limitation being that the scintillator must be readily soluble in the dispersed phase. Scintillators which fluoresce in the region of 0.41 - 0.47 ⁇ m are particularly preferred.
• scintillators examples include : 2,5-di-(5-tert-butyl-2-benzoxazolyl)-thiophene (BBOT) ; 1,4-di-(2-phenyloxazolyl) benzene (POPOP) ; dimethyl POPOP which is 1,4-di-[2-(4-methyl-5-phenyloxazolyl)]-benzene ; and BIS-MSB which is 1,4-di-(2-methylstyryl)-benzene. Since the coatings may be reapplied when the sointillator has decayed below a useful level, this method of application is not limited to the use of long life sointillators as in the case where they are incorporated in the bulk polymer film.
• the aqueous emulsion or dispersion of the scintillator may be prepared by any of the conventional techniques using well known emulsifying or dispersing agents.
• the water content of such emulsions or dispersions is suitably at least 30% by the total weight of the emulsion or dispersion (including the weight of the solids) and preferably between 50 and 90% by the total weight.
• the amount of scintillators employed is usually such as to provide from about 0.01 to 0.5% by weight of the scintillator based on the weight of the polymer substrate.
• Suitable polymeric substrates are, for example, polyethylene, ethylene copolymers such as ethylene-vinyl acetate copolymers, polyvinylchloride, polyvinylfluoride, polyesters such as polyethylene terephthalates and polymethylmethaorylates. and glass,
• the paraffin wax, oleic acid and the scintillator were mixed together at 90°C.
• the water and morpholine were mixed at 90°C.
• the aqueous solution was added to the wax solution and the mixture stirred for 45 seconds in a Silverson mixer. The resulting emulsion was rapidly cooled to room temperature.
• the emulsion was coated onto a transparent substrate using a Sagola paint spray.
• a Sagola paint spray For high transparency coatings the emulsions were sprayed at a temperature of 30 to 40°C.
• the emulsion was prepared as in Example 1 except that the stirring time was 30 seconds. Coatings were produced by spraying.
• the emulsion was prepared as in Example 1. Coatings were produced by spraying.
• the emulsion was prepared as in Example 1. Coatings were produced by spraying.
• the two emulsions were stirred together using a spatula for about 15 seconds. Coatings were produced by spraying.
• Vulcastab and the polyvinyl alcohol were dissolved in the water.
• the scintillator was dissolved in the vinyl acetate. These two solutions were mixed together and shaken to form an emulsion.
• the mixture was transferred to a heating vessel and the ammonium persulphate and the sodium metabisulphate added.
• the mixture was stirred and heated to 50°C.
• the polymerisation of the vinyl acetate occurred at a temperature of 50°C to 60°C over a period of 1 hour. Coatings were produced by spraying.
• the scintillator was dissovled in the toluene.
• the toluene solution was added to the commercial acrylic emulsion and the mixture stirred on a Silverson mixer for 30 seconds at room temperature. Coatings were produced by spraying.

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• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Soil Sciences (AREA)
• Environmental Sciences (AREA)
• Protection Of Plants (AREA)
• Measurement Of Radiation (AREA)
• Greenhouses (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=10280186

Family Applications (1)

Country Status (1)

Cited By (5)

Citations (5)

• 1978
  • 1978-07-05 EP EP78300118A patent/EP0000431A1/fr not_active Withdrawn

Patent Citations (5)

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