WO1996003029A1 - Multilayer polymeric body with interference effect - Google Patents
Multilayer polymeric body with interference effect Download PDFInfo
- Publication number
- WO1996003029A1 WO1996003029A1 PCT/EP1995/002786 EP9502786W WO9603029A1 WO 1996003029 A1 WO1996003029 A1 WO 1996003029A1 EP 9502786 W EP9502786 W EP 9502786W WO 9603029 A1 WO9603029 A1 WO 9603029A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- polymeric
- polymeric body
- light
- multilayer reflective
- polymeric materials
- Prior art date
Links
- 230000000694 effects Effects 0.000 title description 9
- 239000000463 material Substances 0.000 claims abstract description 17
- 230000005855 radiation Effects 0.000 claims abstract description 14
- 230000008635 plant growth Effects 0.000 claims abstract description 12
- 230000019552 anatomical structure morphogenesis Effects 0.000 claims abstract description 8
- 238000012216 screening Methods 0.000 claims abstract description 7
- 229920000642 polymer Polymers 0.000 claims description 7
- 239000000049 pigment Substances 0.000 claims description 5
- 230000001681 protective effect Effects 0.000 claims description 3
- 239000006057 Non-nutritive feed additive Substances 0.000 claims 1
- 239000003795 chemical substances by application Substances 0.000 claims 1
- 239000000975 dye Substances 0.000 claims 1
- 239000000945 filler Substances 0.000 claims 1
- 239000013538 functional additive Substances 0.000 claims 1
- 239000010410 layer Substances 0.000 description 25
- 241000196324 Embryophyta Species 0.000 description 15
- 239000004417 polycarbonate Substances 0.000 description 11
- 229920000515 polycarbonate Polymers 0.000 description 11
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 10
- 239000004926 polymethyl methacrylate Substances 0.000 description 10
- 238000001228 spectrum Methods 0.000 description 9
- 239000002362 mulch Substances 0.000 description 7
- 229920003023 plastic Polymers 0.000 description 4
- 239000004033 plastic Substances 0.000 description 4
- 241000227653 Lycopersicon Species 0.000 description 3
- 235000007688 Lycopersicon esculentum Nutrition 0.000 description 3
- 239000008199 coating composition Substances 0.000 description 3
- -1 for example Polymers 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 230000012010 growth Effects 0.000 description 3
- 229920001684 low density polyethylene Polymers 0.000 description 3
- 239000004702 low-density polyethylene Substances 0.000 description 3
- 239000002985 plastic film Substances 0.000 description 3
- 229920006255 plastic film Polymers 0.000 description 3
- 239000005995 Aluminium silicate Substances 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 241000723353 Chrysanthemum Species 0.000 description 2
- 235000007516 Chrysanthemum Nutrition 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 235000012211 aluminium silicate Nutrition 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 239000005038 ethylene vinyl acetate Substances 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000029553 photosynthesis Effects 0.000 description 2
- 238000010672 photosynthesis Methods 0.000 description 2
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229920001897 terpolymer Polymers 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 240000008415 Lactuca sativa Species 0.000 description 1
- 235000003228 Lactuca sativa Nutrition 0.000 description 1
- 229920002319 Poly(methyl acrylate) Polymers 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 235000004789 Rosa xanthina Nutrition 0.000 description 1
- 241000109329 Rosa xanthina Species 0.000 description 1
- 239000012963 UV stabilizer Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910000323 aluminium silicate Inorganic materials 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 235000010216 calcium carbonate Nutrition 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 244000038559 crop plants Species 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 229920002313 fluoropolymer Polymers 0.000 description 1
- 239000004811 fluoropolymer Substances 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 239000004009 herbicide Substances 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000008121 plant development Effects 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000307 polymer substrate Polymers 0.000 description 1
- 229920000193 polymethacrylate Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 239000005033 polyvinylidene chloride Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000000985 reflectance spectrum Methods 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- 235000012222 talc Nutrition 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 239000012780 transparent material Substances 0.000 description 1
- 244000045561 useful plants Species 0.000 description 1
- 235000013311 vegetables Nutrition 0.000 description 1
- 229940117958 vinyl acetate Drugs 0.000 description 1
- 229920001567 vinyl ester resin Polymers 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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 multilayer polymeric film with interfer ⁇ ence effect. More particularly, the present invention relates to an agricul- tural film for the screening of solar radiation with the aim of influencing plant growth and the morphogenesis.
- Plants in a greenhouse, for example, will not grow so well if the tempera ⁇ ture variation between day and night is large due to a big difference in visible light and NIR radiation impact.
- the photosynthetically active radiation is only desired while other parts of the solar light should be screened be ⁇ cause they have mainly a negative influence on the microclimate.
- the intensive ir ⁇ radiation by sunlight in particular by NIR radiation needs to be screened, in order to avoid too high temperatures within the enclosed area.
- the incoming light beams are to be scattered in order to prevent burnings on plants.
- heat within the area is to be stored at night.
- Mulch films are used in agriculture to improve the growing condi ⁇ tions of the useful plants and to minimize the use of chemical herbicides. For certain crop growers want to intervene in the plant morphogenesis. Morphogenesis is the influence of environmental factors on the shape and appearance of the plant. One of these factors is the spectral energy distri ⁇ bution.
- Greenhouses made of glass already fulfil some of the above-mentioned conditions by virtue of the inherent physical properties of inorganic glasses. Furthermore, constructive measures, for example knurled glass or shadow cloth are known.
- the enclosing material is plastic, such as, for example, polyethylene, polyethylene/vinyl acetate copolymers, poiyvinyl chloride, polycarbonate or polyacrylate, it is much more difficult to meet these requirements.
- plastic such as, for example, polyethylene, polyethylene/vinyl acetate copolymers, poiyvinyl chloride, polycarbonate or polyacrylate.
- the high transparency of many plastics for IR radiation results in good heat transmission which, in the case of films, is additionally assisted by the low film thickness.
- a polymethyl methacrylate glazing material for buildings and vehicles containing an interference pigment for the screening of NIR radiation of a wave length between 800 and 1500 nm is disclosed in DE 2,544, 245.
- the pigment used has a blue-red colour and the light transmitted through the glazing material has a yellow-green colour.
- this glazing material has the disadvantage that portions of visible light which cannot be utilized by the plant are transmitted and, on the other hand, the red portion of visible light which can be utilized by the plant is screened off by said glazing material. Furthermore, the transmitted green portion has the additional disadvantage that it contributes to heating of the greenhouse by virtue of its conversion into long wave light.
- EP-A 0,428,937 describes a grey-white coating composition for green ⁇ houses consisting of a polymer substrate and reflecting particles sus ⁇ pended therein. These particles are aluminium platelets or mica platelets coated with titanium dioxide.
- the coating composition is used for tempo ⁇ rary coatings in extreme weather conditions (summer). In winter, it can again be removed by washing it off with a water jet. More details regarding the pigment used are not given.
- the coating composition has the disadvantage that not only the IR beams but also a substantial portion of the visible light which can be utilized by the plant are reflected by the metal particles. The green portion of the transmitted light cannot be utilized by the plant and contributes to heating of the greenhouse.
- EP-A-03 98243 describes polymeric mulch sheets and mulch films for use in agriculture which have a green absorption colour and contain a UV stabilizer.
- the green sheets and films absorb a large part of the solar ra ⁇ diation which promotes photosynthesis and plant development (PAR), and transmits enough solar radiation so as to heat the soil beneath such films and sheets.
- PAR photosynthesis and plant development
- Such mulch films and sheets reduce weed growth but they have the disadvantage that the photosynthetically active radiation is ab ⁇ sorbed and is lost for the useful plant.
- L.M. Mortensen and E. Stromme describe in Scientia Horticulturae 33 (1987), 27-36 the effects of light quality on some greenhouse crops. Dif ⁇ ferent light qualities were established in growth chambers placed outdoors by selective screening of the natural light spectrum in the chambers.
- the PAR level was the same at all light qualities. Blue light containing a high red/far-red ratio reduced the dry weight compared to natural (N), green, yellow and red light in chrysanthemum, tomato and lettuce. Plant height in chrysanthemum and tomato was strongly reduced by blue compared to N light, and strongly increased by green and yellow light.
- WO 94/05727 discloses a composite material for the selective screening of radiation comprising a polymer and an interference pigment.
- the com ⁇ posite material can be employed in form of films, sheets and webs as cov ⁇ ering for greenhouses, for the influencing of plant morphogenesis and for mulching purposes.
- a multilayer reflective polymeric body of at least first and second diverse generally transparent polymeric mate ⁇ rials, arranged in a sufficient member of alternating layers of said first and second polymeric materials such that a definite part of the light incident on said body is reflected wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 can be employed for the screening of solar radiation with the aim of influencing plant growth and the morphogenesis.
- the polymeric body can be used in the form of a film, sheet or web.
- Multilayer reflective polymeric bodies and their manufacture are well known and described in US patents Nos. 2408398, 2790202, 2 820249, 2 902 754, 3 024494, 3 147 515, 3 308 508, 5 217794 and 5234 729 and in Polymer Engineering and Science 1969, Vol. 9, No. 6, pages 400-404 under the title "Physical Optics of Iridescent Multilayered Plastic Films” by T. Alfrey, E.F. Gurnee and W.J. Schrenk, in a brochure of The Dow Chemical Company titled "Coextrusion of Blown Multilayer Plastic Films" by "J. Schrenk and T. Alfrey, and in Journal of Plastic Film & Sheeting 1994, Vol.
- said polymeric body has an iridescent or silvery appearance but by keeping definite tolerances of the layer thickness of about 5 nm it is possible to reflect a definite part of the light incident on the body. In this case the polymeric body appears in a definite color in the reflected light and in the complementary color in the transmitted light.
- layer thickness By variation of layer thickness, number of the alternating layers and the polymeric material the desired color can be adjusted. That means the re ⁇ flecting band can intensionally be shifted in the spectrum of the sunlight.
- the polymeric material used for the preparation of the composite materials are transparent materials like polyolefins, cc- or terpolymers, for example low-density polyethylene (LDPE), vinylester copolymers like ethylene- vinylacetate copolymer (EVA), fluoropolymers, co- or terpolymers and polyvinylidene chloride (PVDC), polyvinyl chloride (PVC), polycarbonate (PC), polymethylacrylate (PMMA), polystyrene (PS), polyesters (PET, PBTE) or mixtures of transparent polymers.
- LDPE low-density polyethylene
- EVA ethylene- vinylacetate copolymer
- PVDC polyvinylidene chloride
- PVC polyvinyl chloride
- PC polycarbonate
- PMMA polymethylacrylate
- PS polystyrene
- polyesters PET, PBTE
- the polymeric material has to be choosen so that the difference in refrac ⁇ tive index is bigger than .03.
- multilayer reflective polymeric body includes noncontinuous lay ⁇ ers of films, such as lamellar or paniculate structures incorporated into a polymer matrix.
- the protective skin layer improves the mechanical, optical and application properties such as weather resistance, UV stability, and non-drop behav ⁇ ior.
- the number of alternating layers of the polymeric body can be varied be ⁇ tween 30 and 3000, preferably between 50 and 1000.
- the total number of layers for the desired effect depends on the difference of refractive indi ⁇ ces. The smaller the difference the higher the total number of layers.
- PC refractive index n D 1,587
- the spectrum shows that the film is transparent below 700 nm and reflects with a maximum around 740 nm.
- This film therefore is suitable for influencing of the growth of plants, such as vegetables and tomatoes, so that this plants become more compact.
- the background for this photomorphogenetic effect is the change of the red to far red ratio for the phytochrome.
- Fig. 2 shows the refractive spectrum of a polymeric multilayer film which consists of alternating layers of PC and PMMA.
- the total number of layers is 100 and the layer thickness is 100 nm for a PC layer resp. 115 nm for PMMA layer.
- This film is transparent below 620 nm and above 700 nm and shows re ⁇ flection inbetween. This film is suitable for influencing the growth of plants, when slender plants are desired, such as for roses.
- Fig. 3 shows the reflective spectrum of a polymeric multilayer film which consists of alternating layers of PC and PMMA.
- the total numbers of lay- ers is 50 and the layer thickness is 70 nm for PC resp. 105 nm for PMMA.
- This film reflects the green light around 540 nm that cannot be utilized for the growth of plants (minimum of PAR). It is therefore suitable for green ⁇ house films.
- Fig. 4 shows the reflective spectrum of a polymeric multilayer film which consists of alternating layers of PC and PMMA.
- the total number of layers is 500 and the layer thickness is (70 + 0.05 n) nm for PC and (75 + 0.0533 n) nm for PMMA, n indicating the number of layer.
Landscapes
- 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)
- Laminated Bodies (AREA)
Abstract
The invention relates to a multilayer reflective polymeric body of at least first and second diverse generally transparent polymeric materials, arranged in a sufficient member of alternating layers of said first and second polymeric materials such that a definite part of the light incident on said body is reflected, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 for the screening of solar radiation with the aim of influencing plant growth and the morphogenesis.
Description
Multilayer polymeric body with interference effect
The present invention relates to a multilayer polymeric film with interfer¬ ence effect. More particularly, the present invention relates to an agricul- tural film for the screening of solar radiation with the aim of influencing plant growth and the morphogenesis.
It is necessary for a controllable growth of plants to set up special light conditions to affect plant growth and morphogenesis. Special light condi- tions for plant growth, for example, within a greenhouse or under a mulch film include some which are of particular interest. The temperature within the enclosed area as well as the light intensity and the spectral distribution of the incoming light are important factors for the plant growth.
Plants in a greenhouse, for example, will not grow so well if the tempera¬ ture variation between day and night is large due to a big difference in visible light and NIR radiation impact.
From this it follows that the plants stay back in growth. Thus, for the pho- tosynthesis in greenhouses the photosynthetically active radiation (PAR) is only desired while other parts of the solar light should be screened be¬ cause they have mainly a negative influence on the microclimate. There¬ fore the following objectives have to be achieved: Firstly, the intensive ir¬ radiation by sunlight in particular by NIR radiation needs to be screened, in order to avoid too high temperatures within the enclosed area. Sec¬ ondly, the incoming light beams are to be scattered in order to prevent burnings on plants. Thirdly, heat within the area is to be stored at night.
However, in case of mulch films the opposite effect is desired. The PAR should be screened and all other parts of the solar light should be trans¬ mitted. Mulch films are used in agriculture to improve the growing condi¬ tions of the useful plants and to minimize the use of chemical herbicides.
For certain crop growers want to intervene in the plant morphogenesis. Morphogenesis is the influence of environmental factors on the shape and appearance of the plant. One of these factors is the spectral energy distri¬ bution.
Raviv and Allingham describe in "Plastic Culture", No. 59, September 1989, pp. 3 to 12, that diffuse light is favourable for a steady growth of plants. Furthermore, it turned out that diffuse light has the advantage of a more uniform illumination and that it does not damage the plants as much as direct radiation. Hancock describes in "Plastic Culture", No. 79, 1988, pp. 4 to 14, that special additives in LDPE have a favourable effect on the microclimate in greenhouses because of the generation of diffuse light and the creation of a favourably thermic effect in the greenhouses. Suitable additives are aluminosilicate in the form of kaolin, calcium carbonate, talc and kaolin clay.
Greenhouses made of glass already fulfil some of the above-mentioned conditions by virtue of the inherent physical properties of inorganic glasses. Furthermore, constructive measures, for example knurled glass or shadow cloth are known.
If the enclosing material is plastic, such as, for example, polyethylene, polyethylene/vinyl acetate copolymers, poiyvinyl chloride, polycarbonate or polyacrylate, it is much more difficult to meet these requirements. The high transparency of many plastics for IR radiation results in good heat transmission which, in the case of films, is additionally assisted by the low film thickness.
A polymethyl methacrylate glazing material for buildings and vehicles containing an interference pigment for the screening of NIR radiation of a wave length between 800 and 1500 nm is disclosed in DE 2,544, 245.
The pigment used has a blue-red colour and the light transmitted through the glazing material has a yellow-green colour. When used in green¬ houses, this glazing material has the disadvantage that portions of visible light which cannot be utilized by the plant are transmitted and, on the other hand, the red portion of visible light which can be utilized by the plant is screened off by said glazing material. Furthermore, the transmitted green portion has the additional disadvantage that it contributes to heating of the greenhouse by virtue of its conversion into long wave light.
EP-A 0,428,937 describes a grey-white coating composition for green¬ houses consisting of a polymer substrate and reflecting particles sus¬ pended therein. These particles are aluminium platelets or mica platelets coated with titanium dioxide. The coating composition is used for tempo¬ rary coatings in extreme weather conditions (summer). In winter, it can again be removed by washing it off with a water jet. More details regarding the pigment used are not given.
The coating composition has the disadvantage that not only the IR beams but also a substantial portion of the visible light which can be utilized by the plant are reflected by the metal particles. The green portion of the transmitted light cannot be utilized by the plant and contributes to heating of the greenhouse.
EP-A-03 98243 describes polymeric mulch sheets and mulch films for use in agriculture which have a green absorption colour and contain a UV stabilizer. The green sheets and films absorb a large part of the solar ra¬ diation which promotes photosynthesis and plant development (PAR), and transmits enough solar radiation so as to heat the soil beneath such films and sheets. Such mulch films and sheets reduce weed growth but they have the disadvantage that the photosynthetically active radiation is ab¬ sorbed and is lost for the useful plant.
L.M. Mortensen and E. Stromme describe in Scientia Horticulturae 33 (1987), 27-36 the effects of light quality on some greenhouse crops. Dif¬ ferent light qualities were established in growth chambers placed outdoors by selective screening of the natural light spectrum in the chambers. The PAR level was the same at all light qualities. Blue light containing a high red/far-red ratio reduced the dry weight compared to natural (N), green, yellow and red light in chrysanthemum, tomato and lettuce. Plant height in chrysanthemum and tomato was strongly reduced by blue compared to N light, and strongly increased by green and yellow light.
WO 94/05727 discloses a composite material for the selective screening of radiation comprising a polymer and an interference pigment. The com¬ posite material can be employed in form of films, sheets and webs as cov¬ ering for greenhouses, for the influencing of plant morphogenesis and for mulching purposes.
Surprisingly, it has been found that a multilayer reflective polymeric body of at least first and second diverse generally transparent polymeric mate¬ rials, arranged in a sufficient member of alternating layers of said first and second polymeric materials such that a definite part of the light incident on said body is reflected wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 can be employed for the screening of solar radiation with the aim of influencing plant growth and the morphogenesis.
The polymeric body can be used in the form of a film, sheet or web.
Multilayer reflective polymeric bodies and their manufacture are well known and described in US patents Nos. 2408398, 2790202, 2 820249, 2 902 754, 3 024494, 3 147 515, 3 308 508, 5 217794 and 5234 729 and in Polymer Engineering and Science 1969, Vol. 9, No. 6, pages 400-404 under the title "Physical Optics of Iridescent Multilayered Plastic Films" by T. Alfrey, E.F. Gurnee and W.J. Schrenk, in a brochure of The Dow Chemical Company titled "Coextrusion of Blown Multilayer Plastic Films" by "J. Schrenk and T. Alfrey, and in Journal of Plastic Film & Sheeting 1994, Vol. 10, pages 78-79 by J.A. Wheatley and W.J. Schrenk.
Normally, said polymeric body has an iridescent or silvery appearance but by keeping definite tolerances of the layer thickness of about 5 nm it is possible to reflect a definite part of the light incident on the body. In this case the polymeric body appears in a definite color in the reflected light and in the complementary color in the transmitted light.
By variation of layer thickness, number of the alternating layers and the polymeric material the desired color can be adjusted. That means the re¬ flecting band can intensionally be shifted in the spectrum of the sunlight.
The polymeric material used for the preparation of the composite materials are transparent materials like polyolefins, cc- or terpolymers, for example low-density polyethylene (LDPE), vinylester copolymers like ethylene- vinylacetate copolymer (EVA), fluoropolymers, co- or terpolymers and polyvinylidene chloride (PVDC), polyvinyl chloride (PVC), polycarbonate (PC), polymethylacrylate (PMMA), polystyrene (PS), polyesters (PET, PBTE) or mixtures of transparent polymers. The term "polymer" may in¬ clude mixtures of polymers.
The polymeric material has to be choosen so that the difference in refrac¬ tive index is bigger than .03.
The term multilayer reflective polymeric body includes noncontinuous lay¬ ers of films, such as lamellar or paniculate structures incorporated into a polymer matrix.
The protective skin layer improves the mechanical, optical and application properties such as weather resistance, UV stability, and non-drop behav¬ ior.
The number of alternating layers of the polymeric body can be varied be¬ tween 30 and 3000, preferably between 50 and 1000. The total number of layers for the desired effect depends on the difference of refractive indi¬ ces. The smaller the difference the higher the total number of layers.
The entire disclosure of all applications, patents and publications, cited above and below are hereby incorporated by reference.
In order that the invention may be more readily understood, reference is made to the following example, which is intended to be illustrative of the invention, but is not intended to be limiting in scope.
Example 1
Fig. 1 shows the reflectance spectrum of a polymeric multilayer film which consists of alternating layers of polycarbonate (PC refractive index nD = 1,587) and polymethacrylate (PMMA, n0 = 1,491). The total numbers of layers is 100 and the layer thickness is 100 nm for a PC layer resp. 140 nm for PMMA layer.
The spectrum shows that the film is transparent below 700 nm and reflects with a maximum around 740 nm.
This film therefore is suitable for influencing of the growth of plants, such as vegetables and tomatoes, so that this plants become more compact. The background for this photomorphogenetic effect is the change of the red to far red ratio for the phytochrome.
Example 2
Fig. 2 shows the refractive spectrum of a polymeric multilayer film which consists of alternating layers of PC and PMMA. The total number of layers is 100 and the layer thickness is 100 nm for a PC layer resp. 115 nm for PMMA layer.
This film is transparent below 620 nm and above 700 nm and shows re¬ flection inbetween. This film is suitable for influencing the growth of plants, when slender plants are desired, such as for roses.
The background here is the opposite effect of Example 1.
Example 3
Fig. 3 shows the reflective spectrum of a polymeric multilayer film which consists of alternating layers of PC and PMMA. The total numbers of lay- ers is 50 and the layer thickness is 70 nm for PC resp. 105 nm for PMMA.
This film reflects the green light around 540 nm that cannot be utilized for the growth of plants (minimum of PAR). It is therefore suitable for green¬ house films.
Example 4
Fig. 4 shows the reflective spectrum of a polymeric multilayer film which consists of alternating layers of PC and PMMA. The total number of layers is 500 and the layer thickness is (70 + 0.05 n) nm for PC and (75 + 0.0533 n) nm for PMMA, n indicating the number of layer.
This spectrum is similar to the reflection spectrum in T. Alfrey, jr. et al. Polym. Eng. Sci. 9 (1969), 400-404. This film reflects nearly the total PAR spectrum and therefore suitable for mulch foils.
Claims
1. A multilayer reflective polymeric body of at least first and second di¬ verse generally transparent polymeric materials, arranged in a suffi- cient member of alternating layers of said first and second polymeric materials such that a definite part of the light incident on said body is reflected, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 for the screening of solar radiation with the aim of influencing plant growth and the morphogenesis.
2. The multilayer reflective polymeric body of claim 1 wherein said polymeric body is in the form of a film, sheet or web.
3. The multilayer reflective polymeric body of claim 1 wherein said polymeric body includes a protective skin layer on at least one major surface thereof.
4. The multilayer reflective polymeric body of claims 1 to 3 wherein said protective skin layer contains pigments, dyes, fillers, antidrop agents and functional additives and processing aids necessary for the par¬ ticular polymer.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU31117/95A AU3111795A (en) | 1994-07-21 | 1995-07-15 | Multilayer polymeric body with interference effect |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP94111390.4 | 1994-07-21 | ||
EP94111390 | 1994-07-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1996003029A1 true WO1996003029A1 (en) | 1996-02-08 |
Family
ID=8216134
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP1995/002786 WO1996003029A1 (en) | 1994-07-21 | 1995-07-15 | Multilayer polymeric body with interference effect |
Country Status (2)
Country | Link |
---|---|
AU (1) | AU3111795A (en) |
WO (1) | WO1996003029A1 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5922021A (en) * | 1996-04-26 | 1999-07-13 | Jang; G. David | Intravascular stent |
US7081130B2 (en) | 1996-04-26 | 2006-07-25 | Boston Scientific Scimed, Inc. | Intravascular Stent |
US7169222B2 (en) * | 1996-05-09 | 2007-01-30 | Merck Patent Gmbh | Multilayer interference pigments |
US7326241B2 (en) | 1996-04-26 | 2008-02-05 | Boston Scientific Scimed, Inc. | Intravascular stent |
US8562665B2 (en) | 1998-02-02 | 2013-10-22 | Boston Scientific Scimed, Inc. | Tubular stent consists of chevron-shape expansion struts and contralaterally attached diagonal-connectors |
WO2015052319A1 (en) | 2013-10-11 | 2015-04-16 | A. Schulman Plastics | Use of particulate titanium dioxide for reducing the transmission of near-infrared radiation |
US9445926B2 (en) | 1996-04-26 | 2016-09-20 | Boston Scientific Scimed, Inc. | Intravascular stent |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
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US3147515A (en) * | 1961-04-07 | 1964-09-08 | Owens Illinois Glass Co | Apparatus for extruding tubing |
DE2544245A1 (en) * | 1975-10-03 | 1977-04-14 | Roehm Gmbh | INFRARED REFLECTIVE GLAZING MATERIAL |
WO1986007235A1 (en) * | 1985-06-04 | 1986-12-18 | Philippe Gravisse | Method and active filter element for preventing the development of plants |
EP0298942A1 (en) * | 1987-07-09 | 1989-01-11 | Teno AB | Plastic foil |
US4920692A (en) * | 1986-08-06 | 1990-05-01 | Sumitomo Chemical Company, Limited | Mulching film for repelling insect pests |
EP0398243A1 (en) * | 1989-05-17 | 1990-11-22 | Ginegar Plastic Products | Plastic sheets for use in agriculture |
EP0428937A1 (en) * | 1989-11-20 | 1991-05-29 | State of Israel Ministry of Defense Armaments Development Authority, Rafael | Coatings for greenhouses and the like |
EP0455942A2 (en) * | 1990-05-08 | 1991-11-13 | Firma Carl Freudenberg | Utilisation of a photo-selective nonwoven fabric or sheeting for bleaching living plants |
WO1994005727A2 (en) * | 1992-09-09 | 1994-03-17 | Hyplast N.V. | Composite material for the screening of radiation |
-
1995
- 1995-07-15 WO PCT/EP1995/002786 patent/WO1996003029A1/en active Application Filing
- 1995-07-15 AU AU31117/95A patent/AU3111795A/en not_active Abandoned
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3147515A (en) * | 1961-04-07 | 1964-09-08 | Owens Illinois Glass Co | Apparatus for extruding tubing |
DE2544245A1 (en) * | 1975-10-03 | 1977-04-14 | Roehm Gmbh | INFRARED REFLECTIVE GLAZING MATERIAL |
WO1986007235A1 (en) * | 1985-06-04 | 1986-12-18 | Philippe Gravisse | Method and active filter element for preventing the development of plants |
US4920692A (en) * | 1986-08-06 | 1990-05-01 | Sumitomo Chemical Company, Limited | Mulching film for repelling insect pests |
EP0298942A1 (en) * | 1987-07-09 | 1989-01-11 | Teno AB | Plastic foil |
EP0398243A1 (en) * | 1989-05-17 | 1990-11-22 | Ginegar Plastic Products | Plastic sheets for use in agriculture |
EP0428937A1 (en) * | 1989-11-20 | 1991-05-29 | State of Israel Ministry of Defense Armaments Development Authority, Rafael | Coatings for greenhouses and the like |
EP0455942A2 (en) * | 1990-05-08 | 1991-11-13 | Firma Carl Freudenberg | Utilisation of a photo-selective nonwoven fabric or sheeting for bleaching living plants |
WO1994005727A2 (en) * | 1992-09-09 | 1994-03-17 | Hyplast N.V. | Composite material for the screening of radiation |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5922021A (en) * | 1996-04-26 | 1999-07-13 | Jang; G. David | Intravascular stent |
US7081130B2 (en) | 1996-04-26 | 2006-07-25 | Boston Scientific Scimed, Inc. | Intravascular Stent |
US7326241B2 (en) | 1996-04-26 | 2008-02-05 | Boston Scientific Scimed, Inc. | Intravascular stent |
US9078778B2 (en) | 1996-04-26 | 2015-07-14 | Boston Scientific Scimed, Inc. | Intravascular stent |
US9445926B2 (en) | 1996-04-26 | 2016-09-20 | Boston Scientific Scimed, Inc. | Intravascular stent |
US7169222B2 (en) * | 1996-05-09 | 2007-01-30 | Merck Patent Gmbh | Multilayer interference pigments |
US8562665B2 (en) | 1998-02-02 | 2013-10-22 | Boston Scientific Scimed, Inc. | Tubular stent consists of chevron-shape expansion struts and contralaterally attached diagonal-connectors |
WO2015052319A1 (en) | 2013-10-11 | 2015-04-16 | A. Schulman Plastics | Use of particulate titanium dioxide for reducing the transmission of near-infrared radiation |
Also Published As
Publication number | Publication date |
---|---|
AU3111795A (en) | 1996-02-22 |
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