WO2023170215A1

WO2023170215A1 - Improved control of radiation in agriculture

Info

Publication number: WO2023170215A1
Application number: PCT/EP2023/056027
Authority: WO
Inventors: Luc Michiels; Koen STRIJCKMANS; Katrien MICHIELS
Original assignee: Michiels Group
Priority date: 2022-03-09
Filing date: 2023-03-09
Publication date: 2023-09-14

Abstract

Disclosed is the use of a composite of a transparent support further comprising at least one dichroic filter (DF) which composite exhibits, established in accordance with Industry Standard NEN-EN 410, a transmittance ratio of T_IR / T_ sol of at most 120%, wherein T_IR is the near-infrared transmittance in the wavelength range from 900 to 1000 nm and wherein T_ sol is the solar direct transmittance, whereby the use is in agriculture for the control of solar radiation that is allowed into an agricultural enclosure, and/or for the reduction of the radiation emitted from the enclosure towards its environment. The improvements comprise the adjustment of the incoming solar radiation to the needs of the living species underneath, animal and/or vegetal, in accordance with the particular plant species and its stage of development.

Description

Improved Control of Radiation in Agriculture

FIELD OF THE INVENTION

The present invention relates to the field of agriculture. More particularly, the invention provides an improvement in the control and/or household of radiation in agriculture by adjusting the incoming solar radiation in an agricultural enclosure to the specific needs of what the enclosure is protecting and/or the control of the radiation leaving the enclosure. This may apply as well to the harvesting of crops as to the rearing and management of livestock. Benefits may thus also be obtained by controlling the outgoing radiation from the agricultural enclosure, primarily the radiation of heat.

BACKGROUND OF THE INVENTION

Agricultural research is facing a major problem. By 2050 the world population is expected to increase by another 2 billion people, up to a total count of about 10 billion. That population is expected to require 50% more food than today. At the same time, climate change is leading to more volatile weather and generally warmer conditions, which is expected to cause a loss of 17% of our annual harvest from our four key crop groups. The combination of population growth and a fixed footprint of arable land translates into a 20% reduction in the available arable land per person by 2050.

The prime question to be resolved therefore has become “How are we going to feed 10 billion people by 2050 while combating and mitigating the effects of global climate change?” The world will need to double annual yield of crops, meat and eggs to give everyone food security and enable a sustainable industrial base. And all this will have to happen in a sustainable way. An optimal use of our natural resources has therefore never been as important as today. There is not only the need to increase plant and livestock growth, and egg production, but also to have better control over water consumption. Water shortages are increasingly common. Many countries are expected to face more severe water stress in the upcoming future. Its high consumption of renewable water resources puts the agricultural sector in the spotlight. Agriculture is also often reported as a main contributor to the environmental impact of mankind due to leaching or discharge of e.g. nutrients, manure and plant protection products to surface and ground waters. Especially in regions with ample surface water this is already for some years under the attention of governmental bodies and research. In regions with less surface water there is a growing awareness and concern about pollution of (drinking) water sources. Inefficient water management in agriculture is therefore considered as being among the major factors contributing to water scarcity and related environmental problems.

US 3857804 discloses the use of a flexible film of synthetic thermoplastic material having particular transmittance characteristics as a mulching foil through openings of which the desired (cultivated) fruit, vegetable and other plant is grown by obtaining sufficient warming of the soil to promote growth of the desired plant, without at the same time increasing moisture loss or promoting infesting growth. For this purpose the film should have a percentage total transmittance ranging between 0 and 10% for sunlight with a wavelength between 300 and 500 mp (= nm), of 0 to 35% between 500 and 750 nm, from 0 to 90% between 750 and 900 nm, and from 60 to 90% for sunlight with a wavelength above 900 nm. These mulching films may be used in horticulture and floriculture in open air, in greenhouses, in tunnels, etc.

For the harvesting of crops, greenhouses instead of “open ground” agriculture has become mankind’s first and so far prime response to these problems. The surface covered by greenhouses in any shape or form has multiplied by more than six times in recent decades. European and North American agriculture already rely heavily on greenhouses, primarily on the more initial investment intensive glass greenhouses, and the use thereof is also growing in China. Plastic greenhouses, the lower investment alternative also known as “polytunnels”, are increasingly used in Mediterranean countries, and are worldwide becoming increasingly popular for large-scale commercial agriculture. An even simpler form of such greenhouse or polytunnel may be an open-field canopy, i.e. a kind of tent that is sufficiently lightweight that it may be moved by simple means, such as by manpower, from one location in an agricultural field to another location, possibly in the same field.

The greenhouses bring significant improvements in the water management, but the temperature management has remained a major problem, as explained in more detail further below in this document.

Glass greenhouses are high energy-consuming and anti-seasonal production facilities. They are characterized by high energy requirements due to the HVAC (i.e. “Heating, Ventilation and Air Conditioning”) installations that are required to heat and/or cool the greenhouses. In some cases, energy consumption in glass greenhouses accounts for 50% of the cost of greenhouse production. The energy consumption is considered a major factor hindering the development of glass greenhouses. The increase it brings in “carbon footprint” is another drawback in view of the global climate change challenge. Furthermore, the heat build-up (“the greenhouse effect”) affects the crop growth in a negative way and also increases the water consumption substantially. The greenhouse inner temperature has to be managed to be as constant as possible, in order not to become too high or too low to damage the crops or seeds and to obtain a maximum profit. Conventional means to control the greenhouse microclimate, apart from the control of irrigation, are provided by adjusting the ventilation of the greenhouse, often fully automated, which during heat waves may be supplemented by a temporary white coating of the greenhouse roof with a shading agent that reflects high levels of the incident solar energy. But because the coating also reflects much of the useful radiation, it should be removed again when the extreme conditions are expected to have ended.

US 2012/0174477 A1 discloses a transparent greenhouse covering comprising a fluoropolymer foil. The foils that are used admit passage of up to 97% of the entire luminous flux. There is thus no control of any significance of the radiation that is entering or leaving the agricultural enclosure. Inside the greenhouse at least a part of the direct sunlight is by means of light gathering optics concentrated on a fluid filter. The light gathering optics may be provided such that they allow for passage of the entire spectrum or of a part of the entire spectrum, which may be chosen, to be admitted to the plants. The fluid filter can be disposed in the focal lines of focal points of the light gathering optics. The fluid filter should admit passage of the PAR range, but the rest, about 90% of the radiation, must be absorbed and converted into heat. The document also discloses a two-stage filter system wherein the first spectral range reflector filters and reflects a range of the PAR spectrum to the secondary reflector, residual light being admitted through the reflector to a plant area. The filtered and reflected light is directed from the secondary reflector to the plant area. The spectral range reflector should be transparent up to 500 nm, reflecting between 500 and 580 nm and again be transparent above 580 nm. This filter may be a dichroic filter inclined at an angle of 45°.

The heat build-up inside the plastic greenhouses, primarily used in the warmer climates like the Mediterranean areas, is enormous. Ventilation control means are however rather limited. The prevailing crop production strategy so far has been to adapt the crops to sub-optimal climates, meaning a rather limited choice of suitable crops and resulting in lower yields and often limited quality.

To grow and develop optimally, all organisms need to perceive and process the information that it is able to capture from both their biotic and abiotic surroundings. A particularly important environmental cue is light, to which organisms respond in many ways. Because they are photosynthetic and non-motile, plants need to be especially plastic in response to their light environment.

Plants do respond to the photoactive radiation spectrum of the electromagnetic radiation to which they are exposed. Dr. Keith J. Me Cree suggested in the 1970s that the relevant spectrum of wavelengths ranges from 350 to 750 nanometres (nm), and developed his “quantum yield” curve showing a spectral response in function of the wavelength of the incident radiation. This curve is however a generalized light absorption curve that was based on 22 different plant species. It missed the difference between various plant species, e.g. the difference between leafy green pants such as lettuce and chard which prefer more blue light, while flowering and fruiting plants such as tomatoes, cucumbers, chili peppers and paprika prefer more red light. The later developed DIN standard 5031 -10 curve, which is used in horticultural industry, is somewhat more refined, but still not perfect.

An improved promotion of plant development is more recently expected from following the Photosynthetically Active Radiation (PAR) range of the radiation spectrum or PAR curve, because this curve closely follows the combined absorbance for the combination of the most important pigments in plants: the chlorophylls a and b of which both absorbance spectra are showing one peak in the blue and one in the red wavelength region, p- carotene of which the absorbance shows two peaks in the blue region of which one tails into the green region, and the phytochromes for red light (“Pr”) and for far red lignt (“Pf r”) of which the absorbance spectra show a peak respectively in the red and in the far red wavelength region. The PAR curve shows a clear dip in the green range of the visible light (500-600 nm), meaning that plants use only a small portion of the photons in that range.

In addition, negative effects of radiation on the plants should be avoided. The wavelength range below ultraviolet A radiation is known to harm the cell development severely or even could kill cell structures. The wavelength range from far-red till and including infra-red does harm plants also, because it produces only heat. If the leaf temperature of a plant raises, it may in a first stage respond by increased transpiration, and in a further stage by entering into necrosis, meaning that the plant abandons a part, usually first showing up at the extremities of the plant, which turn brown and die off.

Such negative effects are highly undesired because they usually turn the plant from a potential commercial product into waste that needs to be disposed of.

In the rearing and management of livestock, the use of shelters, stables and other suitable agricultural enclosures has also become very widespread as the industry intensified.

A prime example is the farming of poultry, which covers the raising of domesticated birds such as chickens, ducks, turkeys and geese to produce meat or eggs for food. Poultry - primarily chickens - are farmed in great numbers. More than 60 billion chickens are killed for consumption annually. According to the World Watch Institute, 74 percent of the world's poultry meat, and 68 percent of eggs are produced intensively, meaning the animals are farmed using a higher stocking density than the so- called “free-range” farming, hence typically the animals are almost exclusively enclosed in some kind of agricultural enclosure, typically called “stables”, and this in a quite high population density.

The comfort level experienced by the animals living in such environments is important, because it will affect the ultimate yield of meat and/or eggs. High stress levels are known to affect the behaviour of chickens and pigs to the extent that the animals become aggressive towards each other, and injure each other. The animals should preferably experience the cycle of night and day, and temperature and humidity levels should remain within comfortable boundaries. Visible light entrance is therefore a must, conventional wisdom suggests that the more is the better, and it may go as far as suggesting that any reduction in the visible light entrance has a reducing effect on the species underneath. Overheating of the atmosphere in the shelter and/or stable should however be avoided, because that raises the stress level experienced by the animals. Also the exposure to UV radiation should remain limited, because of the harmful effects that this could cause.

Most of the intensive livestock rearing has already become anti-seasonal, meaning many of the stables have heating equipment and some even air conditioning for during the hot seasons or in the hotter regions of the world.

The solar radiation at sea level typically has the following energy distribution:

The ultraviolet range is often further split into UVa (315-380 nm) and UVb (300-315nm). The sun also emits UVc radiation, in the range of 200-300 nm, but that range is in most areas already completely filtered out by the earth atmosphere and therefore does in the areas of interest for agriculture typically not reach the earth surface. UVb radiation, in the range of 300-315 is mostly (but not necessarily fully) blocked by traditional float glass that is used to make windows and greenhouses, as well as by some polymer films, such as polyethylene terephthalate (PET), but this does not necessarily apply to some other polymers, such as polyethylene (PE), which is a popular polymer for making polytunnels.

Full infra-red (IR) radiation is defined as the radiation in the wavelength range from 780 nm up to 1 mm. This wide range is conveniently further divided into IR-A (780-1400 nm), IR-B (1400-3000 nm) and IR-C (3000 nm - 1 mm). Another convenient split is to divide the IR radiation range into near-infrared (N-IR or NIR, for the range from 780 up to 2500 nm), and-far infrared or long-infrared (L-IR or LIR), for anything above 2500 nm. The radiation in this long-infrared range is the heat that we feel from a fire or a heat source.

The energy distribution of the solar radiation has shown that by far most of its non-visible radiation energy is with wavelengths in the NIR range, whereby the IR-A range prevails. The wavelength range of 780- 1400 nm, or the what narrower range of 780-1 100 nm, is thus particularly important. The energy in sunlight at sea level tapers down with increasing wavelengths and hardly contains any energy contribution anymore in the wavelength above 2500 nm. It remains however also important to consider the radiation in the UV wavelength range, at the opposite side of the solar spectrum. The radiation in this range is particularly energy intensive, and some of this radiation may be particularly harmful, as explained herein above.

There remains a need for an improved control of the microclimate inside agricultural enclosures, such as stables, animal shelters, and greenhouses, as well in polytunnels, open-field canopies, as in glass greenhouses.

FR 3019883 discloses a greenhouse with PMMA walls inside of which are provided a plurality of opaque photovoltaic (PV) solar panels, the orientation thereof being electronically controlled in order to obtain a global brightness underneath that is fairly constant throughout the day. The radiation that is entering or leaving the agricultural enclosure remains uncontrolled. The PV panels are provided in an enclosure that is transparent to solar radiation. On the one hand the PV panels produce electric energy and on the other hand they also heat up the air inside the enclosure by direct physical contact with the panels. In an embodiment the lower part of the enclosure containing the PV panels is covered with a solar filter or a dichroic solar filter which has the property of transmitting a part of the solar spectrum and which reflects the other part of the solar spectrum, preferably this latter part being reflected towards the solar PV panels. The document is in particular concerned with the growth of micro-algae, which require a brightness that is rather weak and preferably fairly constant over time.

Visible light entrance is considered a must in all circumstances. Conventional wisdom suggests that any reduction in the visible light entry has a reducing effect on the species underneath, in particular with plants. The industry has already developed solutions in order to bring benefits in this area.

In moderate climate areas like The Netherlands, the lack of sunlight radiation during the darker periods of the year is often supplemented by additional artificial light for specific anti-seasonal crop growth, e.g. for boosting long stemmed red rose supply in the middle of the winter season, e.g. by Valentine’s day (February 14). These developments are increasingly using LED-lighting, whereby the wavelength of the LEDs are chosen in function of the plant species and if possible also in function of the particular development stage that it is in. A major drawback of this approach is that it further increases the investment cost and the energy consumption, as well as the carbon footprint of the activity. Another drawback is that this approach only provides a means to supplement solar radiation, but provides no increase in the protection against the negative parts of solar radiation. During heat waves, there remains the need for the white coating, which is non-selective in reflecting radiation and thus also reflects part of the useful sunlight that plants need for their development. There therefore remains a need for improving the microclimate inside agricultural enclosures by providing a protection against the wavelength ranges in sunlight that are harmful to and/or represent the major cause of heat input towards the inside of the enclosure, and preferably in combination with for plants an improved alignment of the wavelengths of the radiation in the photo active radiation (PAR) that is allowed to reach the plants with the specific needs of the plant, more preferably the specific needs during the particular development stage that the plant is in. At the same time should be avoided the high investment and operating costs, and the environmental and/or climate effects that are associated with the protection and control options that are currently known in the art.

The present invention aims to obviate or at least mitigate the above described problem and/or to provide improvements generally.

SUMMARY OF THE INVENTION

According to the invention, there is provided a use as defined in any of the accompanying claims.

In an embodiment, the present invention provides for the use of a composite of a transparent support further comprising, adhered to one side of the transparent support, at least one dichroic filter (DF) whereby the filter comprises at least one metal layer that is sandwiched in between two layers of dielectric metal oxide, dielectric compound, organic or inorganic, or dielectric salt, and whereby the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410, • a transmittance ratio of T_IR / T soi of at most 120%, wherein T_IR is the near-infrared transmittance in the wavelength range from 900 to 1000 nm, with the relative spectral distribution of the global solar radiation used as weighting function and whereby the weighting factors were normalised over the specified wavelength range, and wherein T soi is the solar direct transmittance, characterised in that the use is in agriculture and for the control of solar radiation that is entering an agricultural enclosure, and/or for the reduction of the radiation emitted from the enclosure towards its environment.

In an embodiment, the present invention provides for a process for incorporating into elements of an agricultural enclosure selected from the ceiling and the walls of the enclosure a composite of a transparent support further comprising, adhered to one side of the transparent support, at least one dichroic filter (DF) whereby the filter comprises at least one metal layer that is sandwiched in between two layers of dielectric metal oxide, dielectric compound, organic or inorganic, or dielectric salt, and whereby the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

• a transmittance ratio of T_IR / T soi of at most 120%, wherein T_IR is the near-infrared transmittance in the wavelength range from 900 to 1000 nm, with the relative spectral distribution of the global solar radiation used as weighting function and whereby the weighting factors were normalised over the specified wavelength range, and wherein T soi is the solar direct transmittance.

We have found that the use of the composite as defined as part of the present invention in agriculture is able to bring a high number of advantages and the use may therefore be for obtaining of at least one and preferably a plurality of technical effects.

The applicants have found that a major advantage brought by the composite according to the present invention is a significant reduction of the transmittance of the part of the solar radiation that only contributes to the generation of heat inside the enclosure underneath the composite. This part of the solar radiation is primarily situated in the near infrared region of the solar radiation spectrum.

The composite that is used in accordance with the present invention comprises at least one dichroic filter (DF). Such a filter is characterised by a transmittance spectrum that exhibits a downward slope with increasing wavelengths in the infrared region, i.e. above 780 nm, and which spectrum continues to slope down all throughout the infrared region. We have seen above that half of the energy in the solar radiation at sea level comes with radiation in the near infrared wavelength range. We have also seen above that animals, crops and plants make no significant use of the radiation in that wavelength range, but that this radiation is the major contributor of heat generated by solar radiation. The applicants submit that therefore a reduction of the radiation in the near infrared wavelength range is a very important and desired property of any object that has the intention of affecting the solar radiation that is passing through it. It is therefore also a prime target property to be provided by the composite that is used according to the present invention. The applicants have found that the transmittance performance in the infrared wavelength range at large, and of the transmittance in the near infrared wavelength range in particular, of the composite that is used according to the present invention, may conveniently be represented by the transmittance in the wavelength range from 900 to 1000 nm, which is in this document conveniently defined as “TJR”. The advantage is that the transmittance in the range from 900 to 1000 nm is readily measurable by simple equipment, such as for instance by the Solar Spectrum Transmittance Meter model # SS2450 from the company EDTM from Ohio, USA. Because of the continuing downward slope of the transmittance curve of a composite containing at least one dichroic filter with increasing wavelengths in the near infrared wavelength and beyond, the applicants have found that the T_IR is an excellent indicator for the transmittance performance of the composite over the entire infrared wavelength range at large, and in the near infrared wavelength range in particular.

The applicants prefer to use as the most relevant parameter the ratio of T_IR / T soi, i.e. the ratio of the transmittance observed in the infrared wavelength range, represented in this document by the T_IR for the range 900-1000 nm, over the solar direct transmittance, i.e. the average transmittance that is observed over the entire range of solar radiation that is ranging from 300 to 2500 nm as wavelength. The applicants point out, because both parameters in this ratio are normalised over their own wavelength range and that these ranges are different, that this ratio may thus be higher than 1 as a fraction or over 100% when expressed as a percentage.

For these reasons, the applicants have found that the T IR / T sol is a very convenient parameter for characterizing the composite that is used as part of the present invention in agriculture. The applicants have found that the composite as specified is excellently suitable for a use for the conditioning of solar radiation incident on crops, such as in agricultural enclosures dedicated for crops or plant development, such as greenhouses in any suitable form or shape, including glass greenhouses, a open-field canopies and polytunnels, but also for the conditioning of solar radiation entering an animal shelter or stable.

The applicants have found that the limited T_IR of the composite that is used according to the present invention brings significant advantages to the user.

Thanks to the dichroic filter in the composite, much less heat is generated upon impact of the filtered solar radiation on anything inside the enclosure, such as on plants and soil, and on other objects inside a shelter, stable, greenhouse or polytunnel. This reduces in the first place the requirements for ventilation, and where the suitable equipment is available also for air conditioning, i.e. the conventional measures known for keeping lower the temperature on and around the livestock or plants that are kept or cultivated underneath the composite. The present invention is thus able to bring a reduction in the energy consumption associated with ventilation and air conditioning in agriculture. And a lower energy consumption brings a reduced carbon footprint to the operation. The present invention therefore represents a contribution to the global climate change challenge.

A better control of the temperature inside an animal shelter or stable brings the advantage that the animals experience less stress. This has as a result that the animals feed better and hence develop faster and stronger. It also has the result that the animals develop less aggression, which reduces the rate of occurrence of injuries inflicted by one animal to another one, such as picking wounds observed with poultry, or tails that are being bitten of by pigs under stress. The reduced injury rate reduces the need for the use of antiseptic treatments and/or the inclusion of antibiotics into the animal feeds. This reduces the occurrence of traces of those chemicals, in particular of antibiotics, in the meat and eggs obtained from the animals.

In botany, a stoma (plural “stomata”), also called a stomate (plural “stomates”) is a pore, found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange, what is often called “the stomatai conductance”. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatai opening.

The term is usually used collectively to refer to the entire stomatai complex, consisting of the paired guard cells and the pore itself, which is referred to as the stomatai aperture. Air enters the plant through these openings by gaseous diffusion and contains carbon dioxide which is used in photosynthesis and oxygen which is used in respiration. Oxygen produced as byproduct of photosynthesis diffuses out to the atmosphere through these same openings. Also, water vapour diffuses through the stomata into the atmosphere in a process called transpiration.

The present invention also keeps lower the temperature of the different parts of the cultivated plants, such as the stem and the leaves. A plant reacts to excessive heat in the first place by extra transpiration, i.e. by further opening the stomata on the plant surfaces such that more water is able to evaporate and extract the heat for that evaporation from the plant. Most of this extra water vapour inside the greenhouse typically leaves via the ventilation system. It is lost to the environment and needs to be replenished by irrigation. The present invention is therefore able to bring the advantage of a reduced water loss, and hence a reduction in the water consumption in agriculture.

When a plant is exposed to more than comfortable levels of heat, the plant goes into stress mode. It puts more, and eventually all, of its efforts into survival, and this comes at the expense of biomass growth, impacts on the flowering, and an impairment of the setting and development of fruit. By the protection against overheating, the present invention brings the benefit of increased biomass growth, and with fruit-bearing crops an increased number and weight of fruits.

When the temperature on the surfaces of the plant stem and leaves raises further and the transpiration of the plant is unable to control the temperature rise, the plant moves into a kind of traumatic response, a process that may be called “necrosis”. The plant starts to sacrifice cells, usually at leave edges or shoot tips. Cell walls rupture and the content of the cell is released, which results in premature death of the cells. Because the dead cells have lost their chlorophyll pigments, their colour turns brown. The appeal of the plant as a commercial product is quickly gone. The plant has become unsaleable. If the stress continues, the plant eventually dies off completely. As soon as the plant has lost its appeal, the commercial product has turned into an unsaleable waste that needs to be removed from the soil and disposed of, and the soil may even need to be cleaned and/or replaced, and its fertilizer content should be brought up again. The operating costs already spent on seeds, fertilizer, irrigation, ventilation and HVAC are wasted, and the return on the investment in the greenhouse is reduced. In addition comes the cost for returning the soil into again arable surface for a new crop. What was intended as a commercial product and a source of income has converted into an extra cost burden for the crop grower.

The composite as part of the use brings the advantage that a significant part of the solar radiation that forms the main contributor to the heat that is generated inside an agricultural enclosure underneath the composite is not transmitted, and therefor does not reach the plant, nor any other internal object or surface. The present invention was found to strongly reduce the occurrence that plants that are protected by the composite against solar radiation move into necrosis. The applicants have found that the present invention provides an excellent protection against excessive heating of the protected plants, against the stress that is associated with such excessive heating, against the risk and occurrence of necrosis. Because this brings a strong reduction in the loss of commercial products, the present invention brings the benefit of a higher yield

The applicants have found that the use of the composite according to the present invention brings yet another significant benefit that is not related to the solar radiation. Heat is emitted by radiation by most common objects. This heat radiation is almost exclusively in the form of radiation in the Long Infared (LIR) range, i.e. radiation with a wavelength from 2500 nm up to as high as 1 millimetre (mm). Soil and plants, like all other objects, also participate in this phenomenon and are sources of radiation in this wavelength range. And so is every other surface on the inside of enclosures like a greenhouse or a polytunnel. The applicants have found that when an agricultural enclosure sees little or no sunlight, which is primarily the case at night, but also in the twilight periods of the day, i.e. during dawn and dusk, high amounts of energy may escape by radiation from the enclosure towards the environment through the roof and the walls of the enclosure.

The applicants have also found that plants may come under stress when the ambient temperature drops too low. The plant is brought outside its comfort zone, and also this reduces the rates of biomass growth, flowering and the setting and development of fruit. It is therefore important to minimize or avoid the exposure of plants to temperatures that are below its range of comfort. This may be important during the normal growing season of the plant, during nights, dawn and dusk, and during cloudy and colder days, but it is even much more important in anti-seasonal plant cultivation. Many of the glass greenhouses in North-Western Europe are for this reason equipped with heating facilities in order to avoid or at least minimize the negative consequences of such exposure.

The applicants have found that the composite that is used in accordance with the present invention is an excellent reflector for heat radiation. Radiation in the long infrared wavelength range (2500 nm and above) is almost totally reflected by the at least one dichroic filter (DF) in the composite. Towards the inside of an enclosure that is properly equipped with the composite, the filter forms some kind of a (radiative) “heat trap”. The so-called “low-E” versions of such a composite are even more effective and approach almost a complete reflection of the L-IR radiation. This means that during colder days of the growing season, or in anti-seasonal cultivation, less heating must be provided in order to maintain the temperature in the enclosure above the lower limit of what is experienced as comfortable by the plants. This means that the present invention again brings energy savings and a reduction of the “carbon footprint”, hence that it makes another contribution of the present invention to the global climate change challenge. Another advantage is that the atmosphere in an unheated agricultural enclosure remains warmer at night or during colder days during the growing season. This is particularly advantageous for agricultural enclosures that have no external heating installation, such as a polytunnel or an open-field canopy.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the transmittance spectrum curves for three 1 FD composites for use in accordance with the present invention, whereby the composites comprise a metal layer made of pure silver.

Figure 2 shows the transmittance spectrum curves for three 2 FD composites for use in accordance with the present invention, whereby the composites comprise a metal layer made of pure silver.

Figure 3 shows the transmittance spectrum curves for three more composites for use in accordance with the present invention, two 1 FD composites and one 2FD composite, whereby the composites are made using other metals than only silver.

Figures 4 and 5 show the transmittance spectrum curves for 1 DF composites made with different rates of water addition covering a wide range of water presence.

DETAILED DESCRIPTION

The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims.

Several documents are cited throughout the text of this specification. Each of the documents herein (including any manufacturer's specifications, instructions etc.) are hereby incorporated by reference; however, there is no admission that any document cited is indeed prior art to the present invention.

The detailed description serves the purpose of describing preferred embodiments of the present invention and is not intended for being a limited representation of the only embodiments in which the present invention may occur or may be applied. The description attempts the clarify the functionalities and the steps that are required for creating the invention and to reduce it to practice. It should be understood that the same or equivalent functionalities and parts may be obtained in or with other embodiments and that also those are intended to be comprised in the scope of the present invention.

The present invention will hereinafter be described in particular embodiments, and with possible reference to particular drawings. The invention is however not limited thereto, it is only limited by the claims. Any drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions in the drawings do not necessarily correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than those described and/or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein may operate in other orientations than described or illustrated herein.

By using words for orientation such as “atop”, “on, “uppermost”, “underlying”, and the like for the location of various elements in the disclosed coated articles, we refer to the relative position of an element with respect to a horizontally-deposed, upwardly-facing support. It is not intended that the films or articles should have any particular orientation in space during or after their manufacture.

The verb "to comprise", as used in the claims in its various grammatical forms, should not be considered as being limited to the elements that are listed in context with it. It does not exclude that there are other elements or steps. It should be considered as the presence provided of these features, integers, steps or components as required, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the volume of "an article comprising means A and B" may not be limited to an object which is composed solely of agents A and B. It means that A and B are the only elements of interest to the subject matter in connection with the present invention. In accordance with this, the terms "comprise" or "embed" enclose also the more restrictive terms "consisting essentially of" and "consist of". By replacing "comprise" or "include" with "consist of" these terms therefore represent the basis of preferred but narrowed embodiments, which are also provided as part of the content of this document with regard to the present invention.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

Similarly it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the claims, any one of the claimed embodiments can and may be used in any combination.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only. Each and every claim is incorporated into the specification as an embodiment of the present invention. Thus, the claims are part of the description and are a further description and are in addition to the preferred embodiments of the present invention. Every one of the claims sets out at least one particular embodiment of the invention. The following terms are provided solely to aid in the understanding of the invention.

Unless specified otherwise, all ranges provided herein include up to and including the endpoints given, and the values of the constituents or components of the compositions are expressed in weight percent or % by weight of each ingredient in the composition.

As used herein, "weight percent," "wt-%," "percent by weight," "% by weight,", “ppmwt”, “ppm by weight”, “weight ppm” or “ppm” and variations thereof refer to the concentration of a substance as the weight of that substance divided by the total weight of the composition and multiplied by 100 or 1000000 as appropriate, unless specified differently. It is understood that, as used here, "percent," "%," are intended to be synonymous with "weight percent," "wt-%," etc., unless otherwise specified.

It should be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. Thus, for example, reference to a composition containing "a compound" includes a composition having two or more compounds. It should also be noted that the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise.

Additionally, each compound used herein may be discussed interchangeably with respect to its chemical formula, chemical name, abbreviation, etc..

In the context of the present invention, an interference filter is an optical filter that reflects one or more spectral bands or lines and transmits others, while maintaining a low coefficient of absorption for all wavelengths of interest.

An interference filter consists at least of multiple thin layers of dielectric material having different refractive indices. The filter according to the present invention also further comprises at least one metal layer. Interference filters are wavelength-selective by virtue of the interference effects that take place between the incident and reflected waves at the thin-film boundaries.

Interference filters are also called dichroic filters. In the context of this document, the terms are used as synonym of each other. In the context of the present invention, a dichroic filter, also known as a thin-film filter, or often also called an interference filter or a thin-film interference filter, is a wavelength range (or “colour”) filter used to selectively pass light of a smaller range of wavelengths compared to what is available, while reflecting other wavelengths. In the context of the present invention, the terms dichroic filter and interference filter are used interchangeably and as synonyms of each other. This document does not follow the more narrow definition in some handbooks in which a dichroic filter is defined as a multilayer structure of high and low index materials. Dichroic filters use the principle of thin-film interference, and produce colours in the same way as oil films on water. Dichroic filters that do not comprise a metal layer do exist, but are considered not to be part of the present invention. An example of such a non-metallic dichroic filter is as follows. When light strikes an oil film at an angle, some of the light is reflected from the top surface of the oil, and some is reflected from the bottom surface where it is in contact with the water. Because the light reflecting from the bottom travels a slightly longer path, some light wavelengths are reinforced by this delay, while others tend to be cancelled, producing the colours seen. Dichroic filters are sometimes also named Fabry-Perot interference filters, or Fabry-Perot (FP) filters, because they are based on the thin film light interference principle that was discovered by Fabry and Perot and which was used to develop the so-called Fabry-Perot interferometer.

In an embodiment according to the present invention wherein the dichroic filter comprises a metal layer, the metal layer contains at least one metal selected from the group consisting of silver (Ag), titanium (Ti), copper (Cu), gold (Au), platinum (Pt), palladium (Pd), aluminium (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), vanadium (V) or stainless steel. The applicants have found that represents a highly convenient embodiment of the composite for use in accordance with the present invention.

In the context of the present invention, parameters reflecting a percent (%) transmittance always relate to a particular wavelength range. The percent transmittance is reflecting the amount of radiation energy within that wavelength range that is able to pass through an object, usually the object being the composite comprising the at least one dichroic filter (DF) or a derivative thereof, relative to the amount of radiation in that same wavelength range that is reaching the object on the impact side of the radiation. In order to keep the different values for % transmittance comparable with each other, the measured transmittance values must be weighted using a selected weighting function and be normalised over the selected wavelength range.

A weighting function used in the context of the present invention is for instance the weighting function for the illuminant D65 reference, to be used as explained in the Industry Standard NEN-EN 410 (2011 , English version) and for which the weighting factors are given in Table 1 of the standard. This weighting function is used for instance in determining the % Visible Light Transmittance or “%VLT” of an object. It already gives normalised weighting factors for the transmittance as measured for wavelength increments each having a width of 10 nm wide over the range from 380 to 780 nm.

The visible light transmittance (VLT, usually expressed in %) or Tv (expressed as a fraction) of a transparent object is thus calculated in accordance with NEN-EN 410 using the following formula (formula 1 from the standard):

Z780 nm

D_AT(A)V(A)AA A=380 nm Tv ^v = - ^-,780 nm

) D_XV(A)AA 4— =380 nm

Whereby in this formula,

Tv is the spectral transmittance of the object, expressed as a fraction,

D_A is the relative spectral distribution of illuminant D65 (available in the industry standard as part of the products of (DA V(A) AA . 10²) from Table 1 , hence expressed in percent),

V(A) is the spectral luminous efficiency for photocopic vision defining the standard observer for photometry, i.e. values that reflect the visual sensitivity of a theoretical human eye, and

AA is the wavelength interval

The parameter VLT, expressed in percent, is then the Tv multiplied by 100.

Another weighting function used in the context of the present invention is for instance the weighting function for the LIV wavelength range, to be used as explained in the Industry Standard NEN-EN 410 (201 1 , English version) and for which the weighting factors are given in Table 3 of the standard. The table gives already normalised weighting factors for the transmittance as measured for wavelength increments each having a width of 5 nm wide over the range from 300 to 380 nm. The formula for calculating the transmittance in the LIV range in accordance with NEN-EN 410 may be shown as follows (formula 25 from the standard):

Whereby in this formula,

Tuv is the UV transmittance of the object to be calculated, as a fraction, T(A) is the spectral direct transmittance of the object, expressed as a fraction, UA is the relative distribution of the UV part of global solar radiation (available in Table 3 as the products of UA with AA),

AA is the wavelength interval.

The parameter T UV, expressed in percent, is then the Tuv multiplied by 100.

For other transmittance values in the context of the present invention, the applicants prescribe that these may be weighted using the weighting factors for the global solar radiation and which should, if not already available as normalised, be normalised over the specified wavelength range. The applicants use the set of normalised weighting factors for the global solar radiation for wavelength increments each having a width in the range of 20 nm to 100 nm wide over the range from 300 to 2500 nm as given in Table 2 of Industry Standard NEN-EN 410, and which is believed to reflect the solar radiation energy, at sea level and with the sun in the zenith position, presumably including both direct and diffuse solar radiation. Where the percent transmittance in a specific subrange thereof is calculated, the weighting factors from this table for that subrange should again be normalised in order to keep the percent transmittance values comparable to each other.

For the total solar direct transmittance of an object, the following formula should be used in accordance with NEN-EN 410 (formula 10 from the standard as published):

Whereby in this formula,

T_e is the solar direct transmittance of the object to be calculated, as a fraction, T(A) is the spectral transmittance of the object, expressed as a fraction,

SA is the relative spectral distribution of the solar radiation (available in Table2 as the product of SA with AA),

AA is the wavelength interval.

The parameter T soi, expressed in percent, is then the T_e multiplied by 100.

For the other transmittance parameters used in the context of the present invention, i.e. TJR, T blue, T red, T far red and T PAR, which all relate to only a particular part of the global solar radiation in terms of their wavelength range, the applicants apply the above formula (10) for T soi, but then only for the specific wavelength range that is selected for that specific parameter. The parameter in percent is than the result of the value, calculated using the appropriate formula in terms of wavelength range, multiplied by 100.

As already stated elsewhere in this document, the visible light transmittance of the composite, i.e. the energy transmittance in the visible light range, may be directly measurable. More difficult but also directly measurable is the visible light reflectance. From these two measurements, the compliment may be calculated which represents the % of visible light that is absorbed. Radiation energy that is absorbed leads to a heating up of the composite, which causes an increased transfer of heat from the composite to its surroundings, both by radiation and by thermal conduction.

Such radiation of heat from construction materials, such as internals of vehicles and buildings, occurs mostly in the high infrared wavelength region, i.e. at wavelengths of 8000 nm and higher, almost exclusively in the long-infrared wavelength range. It is yet another benefit of the composites produced according to the present invention that they exhibit almost full reflection in this L-IR wavelength range. Because this is the range in which objects inside buildings and vehicles emit their heat radiation. By reflecting substantially all of this heat back towards the inside of buildings and vehicles, the composites produced according to the present invention bring the extra benefit of keeping energy inside buildings and vehicles instead of losing that energy as heat radiation through the windows towards the outside.

The low transmittance of most of the heat from the sun towards the internal of buildings and vehicles, which is radiated in the N-IR range, helps to avoid a possible overheating of the inside of buildings and vehicles and hence saves on the burden of any air conditioning systems installed to keep those insides cool, primarily during summer time. The almost full reflection in the L-IR range strongly reduces the loss of heat by radiation from the inside towards the outside of buildings and vehicles, and hence saves on the burden of any heating systems installed to keep those insides warm, primarily during winter times.

In an embodiment, the composite that is used in accordance with the present invention exhibits, in accordance with Industry Standard NEN-EN 410, a transmittance ratio T IR / T sol, of at most 118%, preferably at most 115%, 113%, 1 10%, 108%, 105%, 103%, 100%, or even at most 98%, more preferably at most 95%, 93%, 90%, 88%, 85%, 83%, 80%, 77%, 75% or even at most 73%, even more preferably at most 70%, 68%, 64%, 62%, 60%, 58%, 56%, 54%, 52% or even at most 50%, yet more preferably at most 48%, 46%, 44%, 42%, 40%, 38%, 36%, 34%, 32% or even at most 30%, and even more preferably at most 28%, 26%, 24%, 22%, 20%, 18%, 16%, 14%, 12% or even at most 10%. The applicants have found that the T_IR is a very important parameter in the context of the present invention. The applicants have found that the ratio T_IR / T soi is a very suitable and convenient representative of how the present invention is able to affect the transmittance through the composite of the radiation in the infrared wavelength range as a whole, and in the near-infrared wavelength range in particular, and this relative to the solar direct transmittance, i.e. the average transmittance over the entire range of the solar radiation spectrum. The applicants have found that the present invention is quite successful in reducing the transmittance in this wavelength range and that this reduction is highly beneficial in the uses as claimed in the attached claim set. The benefit brought by the ratio T_IR / T soi as specified, as compared to a situation that does not offer the selective filtering of radiation in the infrared wavelength range as a whole, and in the near-infrared in particular, is an improved household of the energy levels underneath the composite, and the associated effects on the ambient temperature and on the behaviour of living organisms in that situation. The applicants have found that a further reduction in the TJR, in particular when the solar direct transmittance is reduced less than the transmittance in the specific range of 900-1000 nm, and thus when the ratio TJR / T soi is reduced even stronger, corresponds in the context of the present invention to an improved environment underneath the composite. The applicants have found that the advantages brought by the present invention become more pronounced as the TJR, and in particular if also the ratio T JR / T soi is further reduced.

But the applicants have also found that this logic is not unlimited, which will be reflected in what follows.

In an embodiment of the present invention, the TJR / T soi is at least 5%, preferably at least 10%, more preferably at least 15% and even more preferably at least 20%, preferably at least 25%, more preferably at least 30% and even more preferably at least 35%, preferably at least 40%, more preferably at least 45% and even more preferably at least 50%, preferably at least 55%, more preferably at least 60% and even more preferably at least 65%, preferably at least 70%, more preferably at least 75% and even more preferably at least 80%. The applicants have found that it is preferred in the context of the present invention for allowing some, but limited, transmittance in the infrared wavelength range, in particular in the near infrared range, which the applicants consider as being appropriately represented by the parameter TJR in the ratio TJR / T_sol. The applicants have found, due to the general shape of a transmittance spectrum curve for a typical dichroic filter, that a reduction of the ratio TJR / T soi for the composite into extremely low values may bring an undesired effect on the transmittance in the red and far red wavelength range, i.e. on a part of the radiation that is desired and that may even be required by many species, if not all plants. In order to limit the effect on this red and far red light transmittance, the applicants prefer to respect the lower limit for the ratio TJR / T soi as prescribed in this paragraph.

In an embodiment of the present invention, the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

• a visible light transmittance (“VLT”), weighted as for the illuminant D65 reference, of at least 50%, preferably at least 52%, 55%, 57%, 60%, 62%, 65%, 67%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81 %, 82%, 83%, 84%, 85%, 86%, 87%, 88% or even at least 89%.

The applicants have found that living creatures underneath and protected from solar radiation by the composite are more comfortable, experience less stress, and thrive much better if the composite exhibits a visible light transmittance (“VLT”) that complies with the lower limit as specified. The applicants have for instance found, when too much of the visible light was withheld from reaching plants in a greenhouse, that those plants have a tendency for developing stretched stems and less leaves, for showing premature ageing, and even for premature flowering. For several species such as leafy plants or green vegetables, e.g. lettuce, such a development reduces the commercial value of the crop. By complying with this condition, the present invention is therefore able to cause a higher yield in greenhouses, open-field canopies and/or polytunnels.

The applicants have found that composites that comply with this lower limit as specified should preferably be used in moderate climate zones, such as for agriculture in areas that are located on earth in the range of at least +/-40 degrees latitude, more preferably at least +/-45°degrees, even more preferably at least +/-50 degrees and yet more preferably at least +/- 55 degrees latitude. Such composites may be preferred in those particular circumstances and locations because these may not call for very reduced transmissions in the wavelength ranges that are potentially harmful and possibly even lethal for living creatures, such as near-infrared and/or ultraviolet.

In an embodiment of the present invention, the visible light transmittance (“VLT”) is at most 85%, preferably at most 84%, 83%, 82%, 81%, 80%, 79%, 78%, or even at most 77%, more preferably at most 76%, 75%, 74%, 73%, 72%, 71 %, 70%, 69% or even at most 68%, even more preferably at most 66%, 64%, 62%, 60%, 58%, 56% or even at most 54%.

The applicants have surprisingly found that living creatures underneath and protected from solar radiation by the composite may still be able to feel comfortable, thrive well, experience less stress, and develop excellently, when a part of the visible light of the solar radiation is not passing the composite. This is surprising, because it teaches against conventional wisdom which was preaching, e.g. in greenhouse cultures, that every percent of visible light that was withheld from reaching the plants represented a reduction in crop yield. The applicants have surprisingly found, even in a moderate climate zone, that crop yield losses because of insufficient visible light may still remain absent underneath a composite that complies with this upper limit.

A benefit of a composite that complies with this upper limit is that such a composite offers more freedom for also having a reduced transmission in the wavelength ranges that are potentially harmful and possibly even lethal for living creatures. A lower VLT brings the advantage that at the same time also the T_IR and/or the T_UV of that same composite may be reduced further, which is a combination of properties that may be highly preferred in particular circumstances.

The applicants have thereby found that composites that comply with this upper limit as specified should preferably be used in the hotter climate zones, such as for agriculture in areas that are located on earth in the range of at most +/-55 degrees latitude, more preferably at most +/- 50°degrees, even more preferably at most +/-45 degrees and yet more preferably at most +/-40 degrees latitude.

• a transmittance ratio of VLT / T soi of at least 50%, wherein VLT is the average visible light transmission calculated in accordance with NEN-EN 410, weighted for the relative spectral distribution of illuminant D65 and the weighting factors normalised over the specified wavelength range, and wherein the T soi is the solar direct transmittance.

In an embodiment, the composite that is used in accordance with the present invention exhibits, in accordance with Industry Standard NEN-EN 410, a transmittance ratio VLT / T sol, of at least 55%, preferably at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, or even at least 95%, more preferably at least 100%, 105%, 1 10%, 1 15%, 120%, 125%, 130%, 135%, 140% or even at least 145%, even more preferably at least 150%, 155%, 160%, 164%, 168%, 170%, 172%, 174%, 176% or even at least 178%, yet more preferably at least 180%, 182%, 184%, 186%, 188%, 190%, 192%, 194%, 196% or even at least 198%, and even more preferably at least 200%, 202%, 204%, 206%, 208%, 210%, 212%, 214%, 216%, 218% or even at least 220%.

The higher the ratio of VLT / T soi, the less the naked eye of a human observer is noticing any effect of the composite that would be experienced as some kind of “shading”, in spite of the fact that part of the solar direct transmittance is reduced by the presence of the composite. The applicants have found, particularly in the colder and the more moderate climate belts of the world, that compliance with this lower limit as specified may bring more comfort to living creatures underneath the composite, including humans, animals and plants.

In an embodiment of the present invention, the VLT / T soi is at most 250%, preferably at most 245%, 240%, 235%, 230%, 225%, 220%, 215%, 210%, 205%, or even at most 200%, more preferably at most 195%, 190%, 185%, 180%, 175%, 170%, 165%, 160% or even at most 155%, even more preferably at most 150%, 145%, 140%, 135%, 130%, 125% or even at most 120%.

The applicants have found that it may be advantageous to comply with the upper limit as specified for the ratio VLT / T soi, because the applicants have surprisingly found, contrary to conventional wisdom, when a composite is used that significantly reduces the direct solar transmittance (T soi), that the VLT may readily and simultaneously also be reduced significantly without negatively affecting the living creatures underneath the composite. The applicants however prefer that the VLT is not reduced to the same degree as the T soi, and that hence the ratio VLT / T soi preferably also complies with the lower limit, as specified hereinabove.

• a transmittance ratio of T PAR / T soi of at least 120%, wherein T PAR is the average transmission in the Photosynthetically Active Radiation (PAR) wavelength range from 400 to 700 nm, weighted for the relative spectral distribution of the global solar radiation and the weighting factors normalised over the specified wavelength range, and wherein the T soi is the solar direct transmittance.

In an embodiment, the composite that is used in accordance with the present invention exhibits, in accordance with Industry Standard NEN-EN 410, a transmittance ratio T PAR / T soi, of at least 122%, preferably at least 124%, 126%, 128%, 130%, 132%, 134%, 136%, or even at least 138%, more preferably at least 140%, 142%, 144%, 146%, 148%, 150%, 152%, 154%, 156% or even at least 158%, even more preferably at least 160%, 162%, 164%, 166%, 168%, 170%, 172%, 174%, 176% or even at least 178%, yet more preferably at least 180%, 182%, 184%, 186%, 188%, 190%, 192%, 194%, 196% or even at least 198%, and even more preferably at least 200%, 202%, 204%, 206%, 208%, 210%, 212%, 214%, 216%, 218% or even at least 220%.

The higher the ratio of T PAR / T soi, the less a plant will be noticing any effect of the composite that would be experienced as some kind of “shading”, in spite of the fact that part of the solar direct transmittance is reduced by the presence of the composite. The applicants have found, particularly in the colder and the more moderate climate belts of the world, that compliance with this lower limit as specified may bring more comfort to plants, cause less tendency for developing stretching stems, less leaves, premature ageing and/or premature flowering, and hence a higher crop yield.

The applicants have found that composites that comply with this lower limit as specified should preferably be used in moderate climate zones, such as for agriculture in areas that are located on earth in the range of at least +/-40 degrees latitude, more preferably at least +/-45°degrees, even more preferably at least +/-50 degrees and yet more preferably at least +/- 55 degrees latitude. Such composites may be preferred in those particular circumstances and locations because these may not call for very reduced transmissions in the wavelength ranges that are potentially harmful and possibly even lethal for living creatures, such as near-infrared and/or ultraviolet. In an embodiment of the present invention, the T PAR / T soi is at most 240%, preferably at most 235%, 230%, 225%, 220%, 215%, 210%, 205%, or even at most 200%, more preferably at most 195%, 190%, 185%, 180%, 175%, 170%, 165%, 160% or even at most 155%, even more preferably at most 150%, 145%, 140%, 135%, 130%, 125% or even at most 120%.

The applicants have found that it may be advantageous to comply with the upper limit as specified for the ratio T PAR / T soi, because the applicants have surprisingly found, contrary to conventional wisdom, when a composite is used that significantly reduces the direct solar transmittance (T soi), that the transmission in the PAR wavelength range may readily and simultaneously also be reduced significantly without negatively affecting the living creatures underneath the composite. The applicants however prefer that the T PAR is not reduced to the same degree as the T soi, and that hence the ratio T PAR / T soi preferably also complies with the lower limit, as specified hereinabove.

In an embodiment of the present invention, the composite exhibits the following emissivity characteristics established in accordance with Industry Standard EN 12898-2001 ,

• a total corrected emissivity E at 283 K of at most 0.95, preferably at most 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30 or at most 0.25.

The emissivity of the surface of a material is its effectiveness in emitting energy as thermal radiation. Except from very hot objects, thermal radiation is not visible to human eyes, and it has for unheated surfaces its wavelength in the long infrared range, typically above 2500 nm. Quantitatively, emissivity is the ratio of the thermal radiation from a surface to the radiation from an ideal black surface at the same temperature as given by the Stefan-Boltzmann law. The ratio varies from 0 to 1 .

Warm surfaces are usually cooled directly by air, but they also cool themselves by emitting thermal radiation. This second cooling mechanism is important for simple glass windows, which typically have an emissivity that is close to the maximum possible value of 1 .0. "Low-E windows" with transparent low-emissivity coatings emit less thermal radiation than ordinary windows. In winter, these coatings can halve the rate at which a window loses heat compared to an uncoated glass window.

The near normal emissivity should be determined in accordance with EN 12898, as specified. The value should best be quoted to two decimal places. The corrected emissivity (E) is determined from the near normal emissivity in accordance with A.2 of EN 673.

The applicants prefer to use a composite of which the emissivity is reduced as compared to plain float glass. This brings the advantage that heat losses by thermal radiation in the long infrared wavelength range is reduced, which reduces any heating requirements for the inside space, and reduces the carbon footprint. These advantages have been explained in more detail elsewhere in this document.

In order to obtain a composite having a low emissivity in compliance with the upper limit as specified, the applicants prefer to provide on top of the dichroic filter a layer by means of a sol-gel technique, preferably the sol-gel process that is described in WO 2017/097779 A1 , which is able to bring the additional benefits of high hardness and good scratch resistance to the composite.

In an embodiment, the total corrected emissivity £ at 283 K is at least 0.05, preferably at least 0.10, 0.15, 0.20, 0.25 or even 0.30.

The applicants prefer to comply with the lower limit specified for the emissivity because of the technical challenges that have to be overcome in achieving very low emissivity properties. The applicants have found that compliance with the lower limit as specified brings an improved cost/burden ratio for the production process of the composite.

• a transmittance ratio of T_UV / T soi of at most 75%, wherein T_UV is the transmittance in the UV wavelength range from 300 to 380 nm using the relative spectral distribution for the specified part of the global solar radiation as weighting function and the weighting factors normalised over the specified wavelength range, and wherein T soi is the solar direct transmittance.

Preferably the ratio T_UV / T soi is at most 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30% or at most 25%.

Radiation in the range below LIV-A is certainly capable of harming the cell development severely or even killing cell structures. Indeed, plants may be affected as a result of the direct absorption of UV-B by a range of important molecules, including proteins, nucleic acids, and auxins. Consequently, UV-B has the potential to cause significant damage to a plant cell. Although the radiation of the sun in the UV range represents only 5% of the total energy in the full spectrum, the photons in this wavelength range represent a much more concentrated form of energy, which gives this wavelength range extra importance.

A reduction of the exposure to UV radiation as a whole should therefore be beneficial in plant growth, because UV radiation is normally blocking biological life activities and thus affects as well the growth of plants in general.

The applicants have selected the parameter T_UV, in the wavelength range from 300 to 380 nm, as a suitable parameter for representing the transmittance of UV radiation as a whole. For relating the property in the UV range to the performance relative to the full solar radiation, the applicants prefer to specify this performance as the ratio T_UV / T soi as specified.

The applicants have found that a reduction in the T_UV by the composite in the use according to the present invention, due to the general shape of the transmittance curve of a dichroic filter, brings a strong reduction of the transmittance in the UVb wavelength range, which is even more harmful than UVa radiation because it may cause colour loss in plants. In glass greenhouses, the UVb radiation is already mostly kept out because it is almost completely blocked by traditional float glass that is typically omnipresent in the roof and walls of the greenhouse. The same may apply with some polymer materials, such as PET. In other enclosures that do not use float glass or a polymer that blocks UV radiation, this extra effect on UVb transmittance through the composite may be a very important extra benefit, such as with PE films that are popular materials for building polytunnels and open-field canopies, because the composite may be the only significant hurdle for incoming UVb radiation.

The applicants have found that the composite according to the present invention is capable of strongly reducing the exposure of plants to UV radiation, and that this does have a significant and positive effect on leaf formation and an the increase of biomass in the plants in particular, and on plant growth and development in general.

In an embodiment of the present invention, the ratio T_UV / T soi is at least 0.5%, 1 .0%, or even 2.0%, preferably at least 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%, more preferably at least 11 %, 12%, 13%, 14%, 15%, 17.5%, 20%, 23%, 25%, 27% or even at least 30%, even more preferably at least 35%, 40%, 45%, 50% or even at least 55%.

Part of the UV radiation, in the range of UV-A, is beneficial and even needed for the photosynthesis, and hence for plant growth and development. The applicants have therefore found that it is preferable to maintain some but limited transmittance in the UVa wavelength range from 350 to 380 nm. The general shape of the transmittance spectrum of a composite in the use according to the present invention means that the transmittance in the range of 380-400 nm is even and usually significantly higher than this in the UV- A ranges. The wavelength range of 380-400 nm is the start of the visible part of the spectrum and it is also where the absorption of energy by the chlorophyll pigment starts, and hence also the production of biomass from carbon dioxide. The applicants have found that complying with the lower limit for the ratio T_UV / T soi is by this effect in the wavelength range of 350-380 nm beneficial for secondary effects described elsewhere in this document, and in the range of 380-400 nm also beneficial for the development of biomass by plants. A compliance with this lower limit for T LIV / T soi brings a further advantage for fruit-bearing crops that need pollination by insects. The light in this range is not noticed by the human eye, but will be captured for instance by bees. These bees may be necessary to assure the pollination of the flowers of the crops which need to develop into the useful products. Having some UVa radiation available, as inherent with the lower limit on the ratio T LIV / T soi, will further enhance the comfort level of bees underneath the composite, such that these insects are more comfortable and active in the performance of their pollination task.

In an embodiment, the use according to the present invention is for obtaining at least one of the following effects:

• an improved maintenance of a comfortable temperature inside an agricultural enclosure in which animals, crops or plants are kept or grown under the exposure to solar radiation,

• a reduced variation of the temperature inside an agricultural enclosure in which animals, crops or plants are kept or grown under the exposure to solar radiation,

• a reduction of the energy consumption associated with maintaining, inside an agricultural enclosure, of a temperature that is convenient for the animals, crops or plants inside the enclosure,

• a reduction of the consumption and/or increasing the efficiency of the water that is administered for the development of crops or plants,

• the promotion of the growth of biomass in, and/or the growth in general of crops and/or plants under the exposure to solar radiation, e.g. by obtaining a longer and more effective photosynthesis,

• an improvement in the effectiveness and efficiency of photosynthesis,

• the stimulation of stomata aperture in plants, e.g. by extending the opening of the stomata, resulting in an improved photosynthesis,

• the reduction of the crop cycle in plant cultivation,

• the reduction of stress experienced by animals, crops and/or plants in an agricultural enclosure, • the reduction of the risk for the burning of crops and/or plants under the exposure to solar radiation, preferably the reduction of the risk that crops and/or plants exhibit necrosis,

• an improved maintenance of a lower leaf temperature, lower leaf evapotranspiration and/or improved stomatai conductance,

• the reduction of the radiation energy that is directly reaching animals, crops and/or plants under the exposure to solar radiation,

• reducing the direct exposure of animals, crops and/or plants to the near infrared radiation under the exposure to solar radiation, wherein near infrared is the radiation in the wavelength range from 780 up to 2500 nm,

• reducing the direct exposure of animals, crops and/or plants to the harmful part of UV A and/or UV B radiation under the exposure to solar radiation, wherein UV A is the radiation in the wavelength range from 315 to 380 nm, and UV B is the radiation in the wavelength range from 300 to 315 nm, and

• an increase of carbon storage in crops and/or plants, primarily due to the increased growth in biomass.

The applicants have found that the reduction of transmittance brought by the composite comprising the at least one dichroic filter, which may be made quite selective with respective to particular wavelength ranges of interest, is able to bring significant advantages when used in agriculture, especially when used as an element in the construction of an agricultural enclosure such as an animal shelter or stable, or of a greenhouse such as a glass greenhouse, an open-field canopy or a polytunnel. A prime benefit is brought by the reduction of near infrared radiation that is able to reach the inside of the enclosure. A second and also important benefit is brought by the reduction of the UV radiation that is allowed to enter the enclosure. These properties of the composite bring in the context of the use according to the present invention at least one, typically several, and ideally all of the advantageous effects listed above.

In an embodiment of the present invention, the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410, • a transmission ratio of T Far Red / T Red of at most 100%, wherein “T Red” is the weighted average transmittance in the red wavelength range from 600 to 700 nm, weighted for the relative spectral distribution of the global solar radiation and the weighting factors normalised over the specified wavelength range, and “T Far Red” is the weighted average transmittance in the far red wavelength range from 700 to 760 nm, weighted for the relative spectral distribution of the global solar radiation and the weighting factors normalised over the specified wavelength range.

Preferably the ratio of (T Far Red / T Red) in the transmittance spectrum of the composite is at most 99%, 95%, 90%, 85%, 80% or even at most 75%. For some plants, it may be preferable that the ratio is even lower, such as at most 70%, 65%, 60%, or at most 55%, more preferably at most 50%, 45%, 40%, 35%, 30%, 25% or even at most 20%.

The applicants have found that the present invention brings an advantage relative to greenhouses where additional light is provided in selected wavelength ranges, such as by artificial lighting using light emitting diodes (LED). The applicants have found that the present invention is able to improve the behaviour of plants relative to an alternative using the alternative of LED lighting, that radiation in the far red wavelength range remains available in the enclosure that is protected by the composite in accordance with the present invention.

The applicants have found that the present invention is able to provide a ratio (T Far Red / T Red) that may fall in a quite wide range, and may be adapted to the requirements of the environment and the content thereof that is protected by the composite, and if necessary even to the particular stage of development that the content may at particular times be in. The present invention allows for adapting the presence of far red radiation, relative to the availability of red light radiation, to the specific species underneath the composite and even to the specific timing during the development process of that species.

Phytochromes are a class of photoreceptors in plants used to detect light. Phytochrome B1 and B2 are sensitive to light respectively in the red and far-red region of the visible spectrum. They are molecular isomers (cis and trans forms of the same molecule). They control the biological clock of the plant, and let it grow towards light if it experiences shade. Phytochrome B1 absorbs best at 660 nm in the red light range, and the energy of the absorbed photons make it convert into the higher energy level isomer phytochrome B2. Daylight contains lots of red light, so during the day a lot of phytochrome B2 is produced in the plant, and usually it becomes the more prominent of the two phytochromes. Phytochrome B2 slowly returns into B1 , but this process is slow. It takes about 2.5 hours for half of the phytochrome 2 to convert. The high presence of red light as part of daylight assures that at the end of the day the phytochrome B2 level is high. During the night, when the incoming red light radiation is low or absent, the phytochrome B2 continues its slow conversion back into phytochrome B1 , such that at dawn, it is phytochrome B1 that is the more prominent one present. This phenomenon results in a daily phytochrome cycle, and this cycle also reflects the changes in the length of day and night during the 24 hours periods of time.

Phytochrome B2 also converts into phytochrome B1 upon absorption of light of about 730 nm, i.e. in the far red light range. During sundown there is more far-red than red light, and this thus stimulates the return of phytochrome B2 back into B1 .

The combined availability of far red light and red light therefore promote the cycle of these two phytochromes, which is beneficial for the development in the plant during particular phases of its growth cycle.

Many flowering plants react by blooming on the changes in the length of the day according to the different seasons. Long-day plants bloom in spring and summer, short-day plants start blooming when the days become shorter and when a particular length of day has been reached. Day-neutral plants bloom when a particular sum of cold or heat has been reached. Blooming comes for short-day plants when the concentrations of phytochrome B2 are low and those of phytochrome B1 are high, e.g. under a short day of 10 hours and long nights of 14 hours. The plants develop buts and those develop into flowers. Long-day plants on the contrary bloom when the concentrations of phytochrome B2 are higher and those of phytochrome B1 are lower, e.g. when the day counts 14 hours and the night only 10 hours. It therefore appears as that the length of the night determines when a plant is flowering. A similar story applies to the setting of fruit with the appropriate plant species.

Also flowers may react to the phytochrome cycle explained above. Flower buds may open during the day under influence of sunlight or they may only open in the evening hours.

The applicants have found that the composite used in accordance with the present invention may be made to transmit more or less far-red radiation, relative to the radiation in the red light range. The composite performance may therefore be tuned such that the transmitted radiation also affects the phytochrome cycle.

The composite may be made such that its transmittance spectrum shows a ratio of the transmittances in the red light range relative to this in the far red range, here represented by the parameter “T Far Red / T Red”, that complies with the upper limit as specified above. Compliance with this prescription brings the advantage that the light in the far- red range may be limited relative to the radiation in the red light range. Further below it is explained that the present invention may also offer the opposite, i.e. that the radiation in the red light range is more reduced relative to far red, and that this parameter is increased to above a specified lower limit.

By changing the ratio of far red light relative to red light, the applicants have found that it is possible to influence the daily phytochrome cycle in the plant, and thereby change the perception by the plant of the length of the day and night during the 24 hours periods of time. A plant may therefore be made to behave during longer days in a way that it would normally behave during shorter days, or the opposite. And it is possible to combine different light treatments during the same growing season for a particular plant. The applicants have surprisingly found that these effects may already start to show after a relatively short period of time of exposure to the new environment, sometimes even within a few days.

This feature, possibly in combination with or as alternative to other features offered by the present invention, may be used for bringing advantageous effects. In an embodiment, this feature offered by the composite is used to bring a plant into full and simultaneous blooming, e.g. at a time when the fully bloomed plant is in strong demand. For instance, chrysanthemums sometimes called mums or chrysanths, may be controlled to only start blooming in the autumn season and then to bloom with all the flowers at the same time. This may be achieved by making the plant believe that the longer day period extends longer during late summer, by reducing the far red light availability as compared to red light, resulting in a prolongation of the biomass growth and postponing the flower or bud setting, followed during autumn with a change of the ratio in the available light to more far red as compared to red light, such that the plant quickly reverts to flower setting and blooming, eventually resulting in a fully developed and fully blooming plant ready for market, e.g. by the end of October. This may be achieved for instance by keeping the plants in one greenhouse offering the lower ratio T Far Red / T Red during late summer and moving the plants to another greenhouse that is offering the higher ratio T Far Red / T Red at the start of autumn. These effects are currently achieved by means of additional LED lighting during particular periods of the growth season. The present invention is able to bring this effect without the extra energy consumption associated with the LED lighting alternative.

In another embodiment, the present invention is used to have a plant species flower off season. One suitable example is the culture of Phalaenopsis, a commonly known as moth orchids, a genus of about seventy species of plants in the family of orchids. These orchids normally bloom in autumn, when the start of their blooming coincides with a temperature drop from about 28°C to less than 20°C. By exposing these orchids to light having a higher ratio T Far Red / T Red, the plants may be made to initiate bud setting and show flowering off season.

In an embodiment of the present invention, the ratio of (T Far Red / T Red) is at least 10%, preferably at least 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% or at least 70%, more preferably at least 75%, 80%, 85%, 90%, 95% or 100%. As already stated elsewhere, when compared to the use of LEDs in the management of greenhouses, the present invention brings the effect that radiation in the far red wavelength range remains available. Therefore the beneficial effects that may be associated with the availability of radiation in the far red wavelength range become or remain available, and they should be more pronounced if the ratio (T Far Red / T Red) is higher.

In an embodiment of the present invention, this feature may be used in the culture of roses, where it may contribute in the prevention of the outgrowth of shoots so that roses do not produce empty branches. The feature may thus also bring the advantage of creating a larger flower bud at the end of a single erect flowering branch, which for a rose is by far the preferred form as a cut flower.

In another embodiment, this feature may be used to lower the total weight of the flower branches, for example for the Alstroemeria species, commonly called “the Peruvian lily” or “lily of the Incas”. This effect brings a significant effect because it is able to reduce the costs of shipping the flowers.

The applicants have found that the composite used as part of the present invention may affect the availability of radiation in the far red wavelength range relative to the radiation in the red wavelength range. This effect may be brought relative to the availability of these radiations in unfiltered sunlight, but it may also be brought relative to an availability of a radiation spectrum that may already have passed through a medium that has changed that availability of sunlight or that is brought by other means, including artificial means, such as by artificial lighting, e.g. LED lighting.

The applicants have found that this effect may be brought temporarily, such as during particular parts of the day, or of the 24 hours period of one or more days, or during particular development stages of the species that are developing inside the enclosure where the composite may bring protection. The composite may e.g. be used as part of screens that may be brought in place to bring its protection temporarily during one or more periods of the day or one or more periods of a growing season, such as for inducing blooming, fruit setting and/or fruit ripening. This feature, possibly in combination with or as alternative to other features offered by the present invention, may also be used for shaping plants into their habitus.

In an embodiment of the present invention, one may expose plants to more blue light such that more compact plants are created, or more dwarf plants may form.

In another embodiment of the present invention, one may expose plants to more red light and less far red light, thereby turning plants into taller specimens or more erected plants.

• a transmission ratio of T BIue / T Red of at least 10%, wherein “T Red” is the weighted average transmittance in the red wavelength range from 600 to 700 nm, weighted for the relative spectral distribution of the global solar radiation and the weighting factors normalised over the specified wavelength range, and “T BIue” is the weighted average transmittance in the blue wavelength range from 400 to 460 nm, weighted for the relative spectral distribution of the global solar radiation and the weighting factors normalised over the specified wavelength range.

Preferably the ratio of (T BIue / T Red) is at least 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or even 95%. More preferably this ratio is at least 100%, 105%, 1 10%, 1 15%, 120%, 130%, 140%, 150%, 160%, 170% or 175%.

The applicants have found that particular plant species develop better under more blue light, while they appear to make less use from red light. The applicants have found that in particular the growth of biomass may be promoted by complying with the lower limit as specified above for the blue light relative to the red light. This is particularly beneficial for leafy and/or green vegetables, such as lettuce, endive, spinach and/or chard. This feature may also be used to make plants to produce more leaves and to remain compact in growth. Such an effect may for instance be welcome for increasing the commercial value of ornamental indoor plants, because it results in a more desired appearance in the market of potted houseplants.

In an embodiment of the present invention, the ratio of T_Blue / T_Red is at most 200%, preferably at most 190%, 180%, 170%, 160%, 150%, 140%, 130%, 120%, 1 10%, 105% or at most 100%. More preferably this ratio is at most 95%, 90%, 85%, 80%, 70%, 60%, 50%, 40%, or at most 30%.

Some crops have a higher preference for red light than for blue light, at least during a particular part of their growth season. In particular crops that need flowering and fruit setting in order to produce their fruits, in particular when those fruits are commercial products, develop better when under more red light, and hence when the ratio complies with the upper limit as specified. Red light promotes the formation of flower buds and flower induction. For those plants, such as tomatoes and similar blooming crops, in particular once the plant is not in need for more biomass growth in stems and leaves but rather should start blooming and developing fruit, the compliance with the upper limit as specified is found to be beneficial. For tomatoes, once the fruits have reached their full size, need some light at wavelengths in the range of 570-600 nm, which triggers the generation of p-carotene and thereby the start of the ripening of the fruits. The applicants have found, as the ratio for the composite complies with the ratio as specified and thanks to the typical shape of the transmittance spectrum of a dichroic filter, that the plant underneath will also receive more light in the range of 570-600 nm, which should be beneficial for the yield of saleable fruits from the plant.

The applicants have surprisingly found that these effects relating to a changed ratio T BIue / T Red, whether it is an increase or a decrease of the ratio and bringing the ratio within compliance with at least one of the prescribed ranges, may already start to show after a relatively short period of time of exposure to the new environment, sometimes even within a few days.

In an embodiment, the use according to present invention is of the composite, either solely as, or in combination with, a cover for use in agriculture that allows the transmittance of part of the solar radiation, preferably as a component of the cover of an enclosure such as an animal shelter or stable, a greenhouse, an open-field canopy or a polytunnel structure. The enclosure may also be used only temporarily, for instance for triggering, for kicking off the start and/or for promoting a particular stage in the full development cycle of a plant.

In an embodiment, the use according to present invention is for obtaining at least one of the following effects:

• an improved growth of biomass, for instance with leafy and/or green vegetables

• an increase in leave count and/or leave compactness in a plant, such as with potted houseplants or ornamental indoor plants, e.g. for obtaining an improved appearance and/or appeal of the plant,

• preventing the outgrowth of shoots and/or the production of empty branches, an improved bud setting and/or blooming of a flowering plant or crop, the promotion of a larger flower bud, the production of a single erect flowering branch, the flowering of a plant off season, postponing the flowering of a plant species, obtaining full blooming status of a plant at a particular moment in time, reducing the weight of the flower branches in a plant, an improved setting of fruits with a crop, an improved development of fruits with a crop, an improved ripening of fruits with a crop, the triggering of a particular stage in the development of a plant or crop, for instance the bud setting, the fruit setting and/or the ripening of the fruit, the creation of more compact plants and/or dwarf plants the creation of taller plant specimens and/or erected plants. an increase of carbon storage in crops and/or plants.

In an embodiment, the use according to present invention is for limiting the average global horizontal irradiation (GHI) to at most 7.4 kWh/m²/day or 2701 kWh/m²/year, preferably at most 6.5, 6.0, 5.5, 5.0, 4.5, 4.0, 3.5, 3.0 or 2.5 kWh/m²/day. Global horizontal irradiation (GHI) is defined as the total irradiance from the sun on a horizontal surface on earth. It is the sum of direct irradiance (after accounting for the solar zenith angle of the sun z, hence equal to (DNI x cos (z)) plus the diffuse horizontal irradiance (DHI), whereby DNI stands for the direct normal irradiation (DNI) or “beam radiation”, i.e. the power of radiation per unit area of incident sunlight coming directly from the sun disk on a horizontal surface, and DHI is the diffuse horizontal irradiance, i.e. the radiation energy coming from all else except this from the sun disk.

The applicants have found that the composite in the use according to the present invention may bring the benefit of a reduction in general of the total amount of energy that an object or a living creature such as a plant underneath the composite is exposed to. While this advantage may be less important in a moderate climate belt, it may bring major benefits in warmer climate zones, such as the Mediterranean countries, and other regions in the Australian, African, American and/or Asian continent.

The applicants have found that the use according to the present invention may bring more of the benefits described in this document in the climate zones that are characterised by a moderate or warmer climate, because it is in those climate zones that the negative effects of sunlight may be more pronounced and the protection provided by the use according to the present invention may be most beneficial.

In an embodiment of the present invention, the composite is used for reducing the energy consumption associated with controlling the microclimate inside a greenhouse, such as reducing the energy consumption associated with the load for heating, ventilation and air conditioning (HVAC) of the greenhouse, preferably bringing this effect throughout the year.

In an embodiment of the present invention, the at least one layer of the transparent support of the composite, preferably the layer that is facing the plants and/or crops, exhibits the following reflectance characteristics established in accordance with Industry Standard NEN-EN 410, • a visible light reflection (“VLR”), weighted as for the illuminant D65 reference, of at least 5%, preferably at least 10%. The applicants have found, when the at least one dichroic filter (DF) is coated on the support, that the uncoated side of the support of this assembly may exhibit a higher reflection for all wavelengths in general than float glass. When the composite is based on a flexible support and the composite is fixed against the internal side of the roof of a greenhouse, it will typically be the uncoated side of the support that is facing the inside of the greenhouse. Also when the composite is used in constructing a polytunnel or an open-field canopy, it may be arranged that the uncoated side of the support is facing the inside of the polytunnel or open-field canopy. In all those cases, the composite used in accordance with the present invention brings the benefit of providing a higher reflection of radiation that originates from underneath the composite. This may apply for any artificial light, such as LED lights, that is lit underneath the composite, but it may also apply for heat radiation originating from objects, plants or animals underneath the composite. The use according to the present invention may therefore also bring the benefit of a more efficient use of LED lighting in agriculture, as well as all the other benefits explained elsewhere in this document relating to keeping more heat inside the enclosure protected by the composite.

In the present invention, the composite includes, adhered to one side of a transparent support, at least one dichroic filter (DF) which filter comprises at least one metal layer that is sandwiched in between two layers of dielectric metal oxide, dielectric compound, organic or inorganic, or dielectric salt. The applicants have found that this type of dichroic filter is highly convenient for use in the composite that is used in accordance with the present invention.

In the present invention the dichroic filter comprises different layers, and in an embodiment thereof the layers of the dichroic filter are deposited sequentially onto the transparent support using sputter-deposition in at least one sputtering chamber. The applicants have found that represents a highly convenient embodiment of the composite for use in accordance with the present invention.

In an embodiment according to the present invention wherein a dielectric layer is sputtered, the process for the production of the composite comprises, in the sputtering chamber where the at least one of the dielectric layers is sputtered, the introduction of at least one inert gas and water. The applicants have found that this embodiment is able to bring particular beneficial effects, in particular with respect to the optical properties of the dielectric layer and of the dichroic filter as a whole. More details about those effects are explained in the patent application with attorney docket PAT2607598PC00, filed by the same applicant and on the same day as this application and which should have claimed the priority of the European patent application having the reference EP-A-22 161 187.4.

In an embodiment according to the present invention wherein a dielectric layer is sputtered, in the sputtering chamber in which the at least one of the dielectric layers is sputtered, a partial pressure of water is maintained in the range of at least 0.00001 mbar and 0.0015 mbar. The applicants have found that this condition provides optimal conditions for achieving the advantages targeted by the present invention, in particular when the dielectric layer is sputtered in the presence of water.

In an embodiment according to the present invention wherein the dielectric layer is sputtered in the presence of water, the molar flow of the water that is introduced into the sputtering chamber is in the range of 1% to 30% relative to the total molar flow of inert gas that is introduced into the same sputtering chamber. The applicants have found that this condition is preferred for obtaining the advantages brought by the use of water during the sputtering of the dielectric layer of the DF in the composite.

In an embodiment according to the present invention wherein a dielectric layer is sputtered, into the sputtering chamber in which the at least one of the dielectric layers is sputtered, oxygen is introduced as a reactive gas. The oxygen addition may be used without or together with the addition of water during the sputtering. The oxygen may bring the benefit of providing an improved dielectric layer, because it may provide a better basis for subsequently adding the following layer of the dichroic filter.

In an embodiment according to the present invention wherein a dielectric layer is sputtered and oxygen is used during that sputtering, the molar flow of the oxygen that is introduced is controlled in the range of 0.1% to 20% relative to the total molar flow of inert gas that is introduced into the same sputtering chamber. The applicants have found these conditions bring a better embodiment of the composite for use in accordance with the present invention.

In the present invention the dichroic filter comprises at least one metal layer that is sandwiched in between two layers of dielectric inorganic metal oxide, compound or salt, and in an embodiment thereof the dichroic filter further comprises at least one intermediate layer located between the dielectric layer and the metal layer, preferably the filter comprising one intermediate layer on both sides of the metal layer. This embodiment brings the advantage of a much more stable metal layer.

In an embodiment according to the present invention wherein the dichroic filter comprises at least one intermediate layer, the intermediate layer comprises at least one of the metals or alloys from the group consisting of gold, silver, palladium, platinum, palladium, ruthenium or another precious or platinum group metal, nickel, nickel alloyed with chromium, indium, gallium, antimony, arsenic, aluminium, antimony and/or arsenic together with indium and/or gallium, indium antimonide, gallium antimonide, indium gallium antimonide, indium arsenide, gallium arsenide, indium gallium arsenide and indium aluminium arsenide. Preferably the applicants use a composite as described in WO 2021/080951 A1 .

In the present invention the dichroic filter comprises a dielectric layer. In an embodiment of the present invention, the dielectric layer comprises at least one non-metallic material that is transparent to both visible and infrared radiation. These materials include inorganic oxides but other materials such as organic polymer may be included. Suitable organic dielectric material are e.g. described in US 9034459 B2. Preferably the dielectric layer comprises materials having an index of refraction in the range of 1 .4 to 2.7, preferably in the range of 1 .75 to 2.25. Preferably the dielectric layer is made of an inorganic dielectric compound. More preferably the dielectric compound comprises at least one compound selected from metallic and semimetallic oxides, for example lead oxide, bismuth oxide, zinc oxide, indium oxide, tin oxide, titanium dioxide, silicon oxide, silicon dioxide, bismuth oxide, chromium oxide, tungsten oxide, indium titanium oxide, indium tungsten tin oxide, copper(l) oxide, fluorine doped tin oxide (FTO), niobium oxide, lithium doped nickel oxide (L-NiO), barium tin oxide, zinc magnesium beryllium oxide, as well as other inorganic metal compounds and salts, such as zinc sulphide, aluminium fluoride and magnesium fluoride and mixtures thereof. Of these materials, preference is given to zinc oxide, indium oxide, tin oxide, and mixtures thereof, and titanium dioxide. Most preferred is titanium dioxide (TiO2), preferably the dielectric layer is all titanium dioxide (TiO2), or at least a form of TiOx that approaches the formula of titanium dioxide, as explained elsewhere in this document. Other suitable inorganic dielectrics are listed in sources such as Musikant, Optical Materials, Marcel Dekker, New York, 1985, pp. 17-96.

The applicants prefer by far to use inorganic oxides, preferably metal oxides, for the dielectrics as part of the interference filters for the composites produced according to the present invention, because of their high refractive index. A higher refractive index material needs a lower layer thickness for obtaining the same effect.

Layers of metal oxides may also be formed by sputtering. Sputtering is performed in a sputtering chamber in which typically a vacuum is installed of 0.1 Pa up to 10 Pa (typically a few millitorr (mTorr) up to 100 mTorr). A gas may be introduced into the sputtering chamber, often an inert gas such as argon. Oxygen gas may also be used, alone or in addition to an inert gas, for instance when the purpose is to deposit on the substrate a metal oxide such as Ti©2 from a target of titanium metal or from a target made of titanium oxide. The use of a reactive gas, e.g. oxygen, during sputtering, may be addressed as “reactive sputtering”.

Preferred dielectric materials are metal oxides, particularly oxides of metals that readily reduce and become “sub- stoichiometric”, i.e. oxides that readily form vacancies in the solid oxide structure. Examples of very suitable metal oxides are indium tin oxide (ITO) and titanium dioxide (TiO2).

The material preferred by the inventors for forming the dielectric layer(s) in the dichroic stack is comprising titanium dioxide (TiO2), preferably titanium dioxide being the major component in the dielectric layers. The high refractive index of titanium dioxide allows the layers thereof to be thinner than with other materials for obtaining the target effect and required performance. As explained above, such titanium dioxide layer is usually obtained by reactive sputtering of a titanium oxide target, whereby usually oxygen gas is added to the sputtering gas to assure the deposited layer is sufficiently rich in oxygen.

Although the transmission characteristics of a perfect dichroic filter may possibly be predicted by theory and by calculations, the applicants submit that this does not apply to industrially produced dichroic filters. In practice and in particular with sputter deposition, it remains impossible to predict the exact transmission performances of the dichroic filter that is produced. It takes a high level of experience in the art, combined with further trial and error, especially with respect to the various apparatus settings such as pressures, flows, power settings and processing speeds, to obtain a dichroic filter that is exhibiting or at least approaching the transmission performances that are desired.

As already alluded to earlier in this document, e.g. in the Summary of the Invention, the applicants have found that the method according to the present invention is an enabler for producing composites that offer superior transmittance characteristics, as compared to the same method that is not using any water at all during the sputtering of the at least one dielectric layer, or not using water as it is prescribed as part of the present invention. The applicants submit that the present invention further broadens the already wide range of capabilities of a particular sputter deposition apparatus because it offers extra methods that open product possibilities that were not existing or much more difficult to obtain without it. The applicants have found that the method according to the present invention therefore brings the capability to produce composites showing a combination of transmission characteristics that are very difficult to obtain otherwise. The applicants submit that these extra capabilities become possible thanks to the effect that is offered by the method according to the present invention, i.e. the capability to shift the transmittance spectrum to the left, i.e. towards lower wavelength ranges. The present invention thus offers an extra parameter for the sputtering operation, and also this parameter may be varied within a wide range meaning that its level of contribution to the transmission characteristics may also be controlled.

The applicants have further found that the method according to the present invention is particularly suitable for producing composites showing combinations of transmission characteristics that are highly desirable, and which composites may turn out to be highly suitable for use in particular end-use applications.

Because of the complexity of the sputtering process, the wide range of options available for the choice of metals and alloys for the metal layer, including silver but also e.g. copper and aluminium, the wide range of choices for the metals, alloys and compounds in the so-called seed and/or blocker layer, and the wide selection if dielectric materials, all having been discussed elsewhere in this document, and the limited predictability of the transmission characteristics obtained, it remains impossible to prescribe the set of materials, operating conditions, or the ranges of the operating parameters, that inevitably would lead to the desired combination of transmission characteristics. The applicants have found however that the composites as described further in this document are obtainable thanks to the availability of the present invention, and that this capability is illustrated by the examples.

In an embodiment of the present invention, preferably but not only wherein the transparent support has a shear modulus at room temperature of a flexible material, the process for the production of the composite further comprises the step of applying directly on the dichroic filter a protecting film consisting of another flexible film, an acrylate wet coating or a wet coating applied by a method comprising the application of a sol-gel technique, preferably the method and sol-gel technique that are described in WO 2017/097779 A1 for producing a product having low emissivity properties, or by laminating on the interference filter another flexible film, preferably a film comprising a flexible material selected from a polymer, preferably a polymer selected from polycarbonate, poly(meth)acrylate and polyester, such as polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), cellulose triacetate (TCA or TAC), and polyurethane (PU), preferably the other flexible film being a film having a thickness in the range of 5 to 50 micrometre (gm), typically 25 pm.

The protecting film brings the advantage of providing protection to the materials used in the composite, in particular of the metals, alloys and dielectric materials that compose the different layers of the dichroic filter or filters. This brings the advantage that the filter is more stable and is able to provide its shielding properties over a longer period of time.

The protecting film provided by means of the solgel technique brings the advantage that the film applied by that technique may be made to exhibit a very low absorbance in the long-infrared wavelength range, which may bring the advantage that the composite produced according to the present invention may be characterised by a low emissivity (“low-E”). Such a low-E property on the side of the composite that is facing the inside of an enclosure protected by the composite improves the reflection towards the inside of the L-IR radiation, thereby further improving the capability of the composite to represent a “heat trap” by reflecting most of the long-infrared radiation back towards the inside space protected by the composite, bringing and/or further improving the extra advantages explained elsewhere in this document.

In an embodiment of the present invention, preferably but not only wherein the transparent support has a shear modulus at room temperature of a flexible material as discussed further below, the process for the production of the composite further comprises the step of providing an adhesive layer on at least one side of the transparent support of the composite, preferably on the side that has been coated with the dichroic filter, preferably the adhesive layer being provided by lamination, preferably the adhesive layer comprising a dry adhesive, more preferably a dry adhesive selected from a clear dry adhesive (CDA) and a pressure sensitive adhesive (PSA), preferably an adhesive derived from acrylic acid and/or methacrylic acid, preferably the adhesive layer having a thickness in the range of 0.5 to 5 pm, typically 1 .5 pm, whereby on top of the adhesive layer is preferably also provided a release liner for providing protection until the composite is going to be glued to another substrate, preferably the release liner being a PET film having a thickness of about 25 pm. In many applications, it may be advantageous to glue the composite produced according to the present invention to another support, usually a more rigid support in order to give the composite structural support and the assembly with the other support becoming suitable as a construction element.

In an embodiment of the present invention wherein the transparent support has a shear modulus at room temperature typical of a flexible material, the method further comprises the step of providing a hardcoat layer on one side of the transparent support. The hardcoat layer brings extra physical protection to the composite, such as scratch resistance. The hardcoat typically has a lower thickness as compared to the films that are used as transparent support of the composite, or as protecting film for the dichroic filter. The hardcoat may also be made of low absorbance material, e.g. material that is highly transparent for mid-to-long-infrared radiation in the range of 5000 to 25000 nm.

In one embodiment, the hardcoat layer may be provided on the side of the support that is carrying the dichroic filter, also known as the coated side of the transparent support. This brings the advantage that the hardcoat layer brings the extra physical protection on the side where the dichroic filter is residing, and this without the drawbacks brought by an extra protecting film in between the dichroic filter and the hardcoat. These embodiments may for instance be more suitable for use in the inside of an isolating glass unit (IGU), where there is less risk for deterioration because of wear.

In another embodiment, the hardcoat layer is provided on the side opposite of the side that has been coated with the dichroic filter. This may be convenient if the composite is intended for sticking it by means of an adhesive layer directly with the side carrying the dichroic filter onto a transparent support, such as a glass plane, e.g. the inside surface of a single glass window, or of an insulating glass unit, of which one desires to improve the transmission characteristics. This embodiment brings the benefit that the overall solution may count one less organic layer, such as the protecting layer, often a PET layer. There is therefore less material present on the side of the dichroic filter that is exposed to the sunlight, such that less of the energy may be absorbed and converted into heat, such that less heat is dissipating and/or radiated out again. Such composites may thus also qualifty as “low-E” films or foils.

Preferably the hardcoat layer is applied by lamination, preferably the hardcoat comprising an acrylate wet coating or a wet coating applied by a method comprising the application of a sol-gel technique, preferably the method and sol-gel technique that are described in WO 2017/097779 A1 for producing a product having low emissivity properties.

The applicants prefer to provide this hardcoat because of the scratch resistance properties that it provides. The applicants have found that scratches or defects that are caused during the transport, the handling and the fixing of the composite are able to reduce the aesthetic appeal and also the technical performances of the product that is comprising the composite as produced according to the present invention in its target position. The hardcoat brings the advantage that the risk for scratches of other similar defects is minimized.

The hardcoat layer may also be applied when the support is qualified as being “rigid”.

In an embodiment of the present invention, the transparent support has a shear modulus at room temperature of at least 0.5 GPa and at most 80 GPa, meaning the support is qualified as being “rigid”.

The applicants have found that in an embodiment of the use according to the present invention, the transparent support may be a rigid material characterised by the material having a shear modulus at room temperature of at least 0.5 GPa, preferably at least 0.6 GPa, more preferably at least 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1 .00, 1 .1 , 1 .2, 1 .3, 1 .4 or 1 .5 MPa. Using a rigid material for the transparent support brings the advantage that the composite itself may bring mechanical strength and that therefore the composite itself may be used as a construction element. There is thus no need to provide an extra mechanical support for supporting the dichroic filter, which is advantageous because all suitable transparent materials do bring their own effects on the transmittance spectrum of the assembly with the composite produced according to the present invention. This embodiment thus brings the advantage that the transmittance spectrum of the composite allows to also fairly correctly predict or derive the spectrum of the radiation that is expected to pass through the ultimate construction element that is intended to contain the composite.

The applicants have found that many materials are suitable as a rigid transparent support. Preferably the transparent support is comprising a material selected from glass, suitable forms of polyester, including polyethylene terephthalate (PET) and polyethylene naphthalene (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), polyethyl methacrylate (PEMA), and other acrylic plastics, polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polyphenyl ether (PPE), polyamide, such as nylon 1 1 or polyamide 11 (PA11 ), combinations and copolymers of some of these polymers such as PET/PMMA, PET/coPMMA, PVDF/PMMA, PVDF/coPMMA, PEN/PMMA, PEN/coPMMA, PEN/coPE, PEN/sPS, PEN/coPET and PEN/PETG, whereby PETG refers to polyethylene terephthalate glycol-modified. Preferably the glass is selected from float glass and curved glass, preferably the transparent support being one layer of laminated glass.

The applicants have found that the composite produced according to the present invention and having a rigid support may bring its target beneficial technical effects into practice in many applications. One of those highly suitable applications is as an element in so-called “laminated glass”, in which the term “glass” should be understood much broader because it may include other suitable polymers such as polycarbonate, PMMA or another acrylic plastic.

In an embodiment of the present invention wherein the transparent support is one glass layer of laminated glass, the method further comprising the assembly of the laminated glass. This assembly may comprise a sequence of steps. In one embodiment, the assembly may comprise the application of the precursor composition of the intermediate plastic or polymer adhesive layer of the laminated glass onto the interference filter. Alternatively the assembly may comprise the steps of applying the dichroic filter onto the layer of precursor composition or on the adhesive layer that has already been formed on a glass layer, positioning a second glass layer of the laminated glass onto the intermediate plastic layer, on the dichroic filter or on a second intermediate layer of either precursor composition or on an adhesive layer that was coated on top of the dichroic filter. The assembly may then further comprise the step of bonding the layers together by cross-linking the intermediate plastic layer under pressure and/or temperature, preferably the intermediate plastic layer comprising polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), at least one ionoplast polymer, cast in place (CIP) liquid resin, or thermoplastic polyurethane (TPU), more preferably the intermediate plastic layer being an elastic material such as EVA, TPU or “acoustic PVB”.

The uses of laminated glass are plenty, and the composite produced according to the present invention may bring benefits in almost all of them.

In an embodiment of the present invention wherein the transparent support is one layer of laminated glass, the laminated glass is used in the construction of a building, in a greenhouse, an animal shelter or stable.

In an embodiment of the present invention, the transparent support has a shear modulus at room temperature typical of a flexible material, meaning that the shear modulus is in the range of at most 0.5 GPa and at least 0.1 MPa.

The applicants have found that in an embodiment of the use according to the present invention, the transparent support may be a flexible material characterised by the material having a shear modulus at room temperature of at most 0.2 GPa, preferably at most 0.1 MPa, more preferably at most 750, 600, 500, 400, 250, 100, 75, 50, 25, 10, 5.0, 1.0, 0.5 or 0.15 MPa.

Preferably the transparent support comprising a flexible material selected from a polymer, preferably a polymer selected from polycarbonate, poly(meth)acrylate, another acrylate polymer, and polyester, such as polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), cellulose triacetate (TCA or TAC), and polyurethane (PU), further possibilities being suitable forms of polyester, including polyethylene terephthalate (PET) and polyethylene naphthalene (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), polyethyl methacrylate (PEMA), and other acrylic plastics, polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), polyphenyl ether (PPE), polyamide, such as nylon 11 or polyamide 11 (PA1 1 ), combinations and copolymers of some of these polymers such as PET/PMMA, PET/coPMMA, PVDF/PMMA, PVDF/coPMMA, PEN/PMMA, PEN/coPMMA, PEN/coPE, PEN/sPS, PEN/coPET and PEN/PETG, whereby PETG refers to polyethylene terephthalate glycol-modified.

In an embodiment of the present invention the transparent support is a film having a thickness in the range of at least 5 and at most 50 micrometre (pm), preferably at least 10, 15, 20 or 25 pm and optionally at most 45, 40, 35, 30, 25, or 20 pm.

In an embodiment of the present invention, the dichroic filter is coated on a temporary support, which may be rigid, e.g. one of the suitable rigid materials listed elsewhere in this document, but preferably is flexible, e.g. one of the suitable flexible materials listed elsewhere in this document, and which has first been coated with a first adhesive layer. This first adhesive layer may e.g. be applied by a conventional coating technique, such as described elsewhere in this document, and the temporary support carrying the first adhesive layer may then be subjected to the sputter-deposition treatment as specified as part of the method according to the present invention for applying the layers of the dichroic filter. Alternatively the first adhesive layer may be applied by an extra sputtering step, possibly performed upstream of the sputtering-deposition applying the layers of the dichroic filter. The dichroic filter is thus applied after, and preferably atop the first adhesive layer. The adhesive layer should be transparent, hence the process of applying the dichroic filter is still complying with the prescriptions of the method according to the present invention.

This intermediate film may be convenient for storing and transporting the dichroic filter to where it is brought into its final position. Later, before bringing the dichroic filter into its ultimate position, a second adhesive layer may be applied onto the side of the dichroic filter opposite the side with the first adhesive layer. This second adhesive layer may be applied using any conventional coating technique, such as evaporation or chemical vapour deposition (CVD), but may also be applied using sputtering. Before or after applying this second adhesive layer, the temporary support may be removed and the dichroic filter, sandwiched between the two adhesive layers, may then be glued in between two transparent supports. In the case of laminated glass, at least one and preferably both of these two transparent supports is glass or a suitable alternative listed elsewhere in this document. It is quite common that the assembly comprises a suitable treatment step to make the two adhesive layers stick to the transparent supports, typically by causing cross-linking in and/or of the adhesive layers. This may be performed by exposure to pressure and/or temperature, or by the treatment by means of an E-beam crosslinking apparatus.

In this embodiment of the process, the temporary support may but must not necessarily be transparent. The composite of the method according to the present invention is thus obtained in all the embodiments. When the temporary support is non-transparent, this composite is certainly and possibly again obtained after the temporary support has been removed. The temporary support thus acts as a temporary carrier layer that is not functional in the end-use application, but is only needed for allowing the application of the layers of the dichroic filter specified as part of the composite that is the ultimate product of the method according to the present invention.

In an embodiment of the present invention wherein the transparent support has a shear modulus at room temperature of a flexible material, the method further comprises the step of providing an adhesive layer on at least one side of the transparent support, preferably on the side that has been coated with the dichroic filter, preferably the adhesive layer being provided by lamination, preferably the adhesive layer comprising a dry adhesive, more preferably a dry adhesive selected from a clear dry adhesive (CDA) and a pressure sensitive adhesive (PSA), preferably an adhesive derived from acrylic acid and/or methacrylic acid, preferably the adhesive layer having a thickness in the range of 0.5 to 5 pm, typically 1 .5 pm, whereby on top of the adhesive layer is preferably also provided a release liner for providing protection until the composite is going to be glued to another substrate, preferably the release liner being a PET film having a thickness of about 25 pm. In many applications, it may be advantageous to glue the composite produced according to the present invention to another support, usually a more rigid support in order to give the composite structural support and the assembly with the other support becoming suitable as a construction element. This embodiment brings the advantage that the composite contains only one layer of transparent support, typically thus only the one layer on which the dichroic filter has been deposited, and therefore exhibits a very low absorbance in the long-infrared wavelength range compared to composites containing two layers of the support type, in many cases both being PET films. This brings the advantage that the composite produced according to the present invention may be characterised by a low emissivity (“low-E”). Such a low-E property of the composite is important when the composite is protecting an enclosure or inside space from heat input from the outside. This is because there is less material available for absorbing radiation energy, in particular on the side of the dichroic filter that is facing the outside of the enclosure. This results in a lower heating up of the construction element of which the composite has become a part, which means that the construction element will thus emit less radiation in the L-IR wavelength range, and thus less heat, to its surroundings, importantly also towards the inside of the enclosure.

The applicants have found that the composite based on a flexible support may form an excellent start for producing a product that is highly suitable in particular applications.

In one embodiment of the present invention, the transparent support comprises a plastic film or foil and the composite is attached to a surface of a glass plate that is comprised as part of a glass greenhouse. Preferably the composite is attached to the inner surface of the glass plate. Preferably the composite is attached to the glass surface by a layer of adhesive.

In another embodiment, the transparent support comprises a glass plate and the composite itself is comprised as part of a glass greenhouse. In yet another embodiment, the transparent support comprises a plastic film or foil and the composite is used as part of a plastic greenhouse or so-called polytunnel, or even an open-field canopy.

In an embodiment, the composite is part of a temporary cover that is mobile and may be used during only a part of the growth season of a plant or crop. This embodiment is particularly suitable for impacting at a particular moment or during a particular part of the growth cycle of the plant or crop.

In an embodiment of the present invention, the composite is used in at least one of the following forms:

• With two adhesive layers, one on the side of the dichroic filter and one on the opposite side, sandwiched in between two transparent plates, thereby forming an assembly,

• With one adhesive layer glued to one side of a transparent plate such as a glass plate, thereby forming an assembly, by means of the adhesive layer that is provided directly on the dichroic filter or alternatively on the opposite side of the composite,

• With a protective film stretched in between surfaces 2 and 3 of insulating glass, thereby forming an assembly,

• With a protective film sandwiched between two layers of intermediate plastic that are sandwiched between the two rigid transparent plates, together forming an assembly.

In the art of insulating glass units, it is industry practice to number the surfaces starting with giving the exterior surface of the glass unit the number 1 (one), and sequentially increasing the number for the subsequent surfaces that are encountered when one is counting towards the interior surface of the glass unit.

The applicants have found that these forms as listed are highly suitable for obtaining the effects that are achievable by means of the present invention.

In an embodiment of the present invention, the composite is used as an element of a greenhouse, a polytunnel, an open-field canopy, an animal shelter or a stable. The applicants have found that the uses as listed are highly suitable for bringing the effects achievable with the present invention.

EXAMPLES

PRODUCTION METHOD OF THE COMPOSITE.

These examples are using composites of which the dichroic filters (DF) were coated onto a film or foil made of polyethylene terephthalate (PET).

The composites were produced using a sputtering apparatus that is comprising five (5) vacuum chambers in series. Vacuum chamber 1 is the unwinding chamber and vacuum chamber 5 is the winding chamber, although these functions may in certain embodiments be switched as explained further below. The three intermediate vacuum chambers are sputtering chambers, chambers 2 and 4 for sputtering in each one a dielectric layer and the middle chamber 3 for sputtering at least the metal layer, and if appropriate also a seed layer and/or a blocking layer. Middle chamber 3 is subdivided into three subchambers numbered 3.1 , 3.2 and 3.3. Subchambers 3.1 and 3.3 are provided for sputtering respectively a seed layer and/or a blocking layer, subchamber 3.2 is for sputtering a metal containing layer.

The flexible substrate is unwound from a roll placed in the unwinding chamber, passes successively through the three sputtering chambers, and is wound again into a roll in the winding chamber. The substrate is passing from one chamber to the next through a slit that is made as narrow as possible but sufficiently large for letting the substrate pass without creating any impediment or hinder to the movement of the substrate.

The apparatus is thus equipped for coating onto the substrate in one pass of the substrate one full sequence of layers necessary for forming a stack that may correspond to one complete dichroic filter. The symmetrical arrangement, if the apparatus is also equipped for operating in the reverse direction, may allow for subsequently returning the substrate with its first dichroic filter again in the opposite direction through the same apparatus and coating on top of the first filter the extra layers that are needed for forming a second dichroic filter, and this preferably without having to open the apparatus. Alternatively for obtaining a two dichroic filter product, after having coated the first dichroic filter, the apparatus may be opened and the roll of foil with the first dichroic filter on it may be physically moved from the winding chamber to the unwinding chamber. The apparatus may then be closed again and brought under the required deep vacuum, after which the second dichroic filter may be coated on top of the first one during a second pass that the product is making through the entire apparatus.

Each one of the 5 vacuum chambers is connected with the vacuum pumping system that is provided for pulling and maintaining the required vacuum throughout the entire apparatus. The middle chamber is provided with 5 turbo high vacuum pumps arranged in parallel, the other four main chambers with 4 of such vacuum pumps each, also in parallel. The outlet of these 21 pumps come together into one common manifold, in which during operation a vacuum pressure is maintained in the range of about 0.01 mbar to 0.1 mbar by means of a vacuum pumping system comprising a sequence of first and upstream a roots vacuum pump followed in series downstream by a rotation vacuum pump which delivers into the atmosphere. Three of such vacuum pumping systems are provided in parallel, of which all three are used during start-up and only two are sufficient during normal operation.

The slits connecting chamber 3 with chambers 2 and 4 are both equipped with a transit chamber consisting of a widening of the slit. Each one of these transit chambers is preferably also connected via at least one dedicated connection with the vacuum system.

A controlled supply of inert gas is provided individually to each one of vacuum chambers 2 and 4, and to subchambers 3.1 , 3.2 and 3.3, by means of mass flow meters. Vacuum chambers 2 and 4 are further provided with a controlled supply of oxygen gas, also via mass flow meters. Vacuum chambers 2 and 4 are also equipped with a controlled supply of water vapour, each time by being connected to two side chambers for containing an amount of liquid water below an amount of water-containing vapour phase, each connection through a dedicated control valve. These side chambers preferably have transparent walls and may be disconnected from the vacuum chamber upstream of the control valve, such that the liquid in the chamber may be replenished.

In the winding chamber 5, upstream of the winding roll, is provided a measurement device for measuring the transmittance spectrum of the coated PET film over the wavelength range of 320 to 1050 nm.

EXAMPLE 1 - Silver based 1 DF and 2DF composites using oxygen

A roll of plastic foil with a width of 2 meters and a thickness of 50 pm was installed in vacuum chamber 1. The foil, in this document also called the plastic film, was made of polyethylene terephthalate (PET). The available end of the foil was brought from the unwinding roll through the entire apparatus, over every guiding roll and windlass and passing close to each one of the sputtering targets as well as the transmittance spectrum measurement device, and was finally attached to the winding roll in the winding chamber 5. The apparatus was closed and a vacuum between 1 . 10^-4 millibar (mbar), i.e. 0.01 Pa, was installed in vacuum chambers 2 and 4, while a vacuum of about 1 . 10^-5 mbar (i.e. 0.001 Pa) was installed in vacuum chamber 3, including in all the three subchambers thereof. After having established these vacuum pressures in the different vacuum chambers, the following flows of argon were installed, expressed as standard cubic centimetres per minute (seem):

These numbers for the inert gas flows were calculated starting from the weight flow that is read from the mass flow meters, converted first into a molar flow using the known molecular weight of the inert gas composition, and subsequently converting the molar flow into a standard volumetric flow using the known conversion factor from moles to gas volumes at the standard conditions of atmospheric pressure and 0°C.

Vacuum chambers 2 and 4 were each provided with a suboxide TiOx sputtering target in which “x” was in the range of 1 .6 to 1 .9. In vacuum chamber 3 were provided a sequence of 3 sputtering targets: target 2 made of silver, targets 1 and 3 were alloys made of 80%wt of nickel with 20%wt of chromium.

Before starting the production run, the apparatus is closed, and the vacuum systems are started up in the following sequence: the 3 rotating pumps are started first and able together to tighten all the seals and fully closing each one of the vacuum chambers. The roots pumps are commissioned subsequently until the pressure in the common manifold reaches its target. Then the turbo vacuum pumps are commissioned. Once the target deep vacuum is reached, the vacuum system is kept operating for another 9 hours before the production run is started.

The PET film movement was started from the unwinding roll to the winding roll, at a speed of 75 cm per minute. The sputtering targets were powered sequentially from sputtering chamber 2 over subchambers 3.1 , 3.2 and 3.3 up to chamber 4. The magnetrons in the vacuum chambers were provided with the following powers, expressed in kilowatt (kW). The magnetrons in chambers 2 and 4 were AC magnetrons, the magnetrons in chamber 3 were all DC magnetrons.

Once the target vacuum pressures were obtained and stable, towards each one of vacuum chambers 2 and 4 was installed a flow of oxygen of 18 seem. After 4 hours of operation the transmittance spectrum 200923C51 of Figure 1 was registered. The production run was continued until the PET film was completely unwound from the unwinding roll in the unwinding chamber, and wound in the winding chamber.

After the first production run, the coated film was rewound back onto the unwinding roll and the film was passed a second time through the same apparatus using slightly different conditions.

The second production run commenced after reclosing the apparatus, the starting up thereof and after a period of 9 hours of vacuum pumping in order to assure stable pressure conditions.

During this second pass, the following powers were provided to the respective magnetrons in the corresponding vacuum chambers and subchambers:

The same oxygen addition was applied as during the first production run, such that a 2DF composite was formed in which the dielectric layers were deposited under similar conditions in the atmospheres in vacuum chambers 2 and 4. This second production run resulted in a product of which the transmittance spectrum 20024C50 shown in Figure 1 was registered.

For the spectra 200923C51 and 20024C50 were calculated the %VLT using the weighting as specified in NEN-EN 410 for the illuminant D65 reference, the %T_sol using the weighing as specified in NEN- EN 410 for the global solar radiation, and, this time using the weighting as specified in NEN-EN 410 for the global solar radiation and normalised for the specified wavelength range, the % transmittance in the range 300-380 nm (T_UV), in the range 400-460 nm (T blue), in the range 600-700 nm (T red), in the range 720-760 nm (T far red), in the range 400-700 nm (T_PAR) and in the range 900-1000 nm (TJR). The results are shown in Table 1. Also the colour difference from the colour of the illuminant D65 was calculated in accordance with ISO 11664-4: 2008 in the CIE L*a*b colour space. Table 1

The results in Table 1 show that the 1 DF composite may already achieve a significant reduction in the transmittance of radiation in the near-infrared range (T_IR), in the ultraviolet range (T_UV) and in the solar direct transmittance (T soi), while the composite still shows a very high VLT, meaning that the human eye would not at all notice the presence of the composite, and a high T PAR, meaning that plants and/or crops would still receive the portion of the solar spectrum that is beneficial for their growth and evolution. The 2DF composite shows that the transmittance properties TJR, T IIV and T soi are more strongly reduced, while still maintaining a fairly high VLT and a high T PAR. The applicants have found that also the presence of the 2DF composite would still pass as good as unnoticed for the human eye.

The colour transmittance ratios T blue / T red in Table 1 show that the 1 DF composite only slightly enhances the red over the blue contribution, while the 2DF composite enhances the red contribution to a much larger extent. The colour transmittance ratios T far red / T red show that the contribution of far red light relative to the red light for the 1 DF composite remained unchanged, while the 2DF composite only moderately reduces the far red light contribution relative to the red light contribution in the transmitted radiation.

The results for the colour differences for the two composites demonstrate that the transmitted radiation shows a minor colour deviation for the 1 DF composite and a more noticeable visible colour deviation for the 2DF composite. The applicants have observed that only the 1 DF composite would be experienced by the human eye as being fully “colour neutral” in its transmittance. This means that such composites would not exhibit any colour deviation that would divulge the presence of the composite to a human observer. This further confirms that the naked eye of a human observer would not notice the presence of the 1 DF composite.

This example demonstrates that the present invention is able to change the relative importance of blue and/or far red light in the transmitted spectrum relative to the red light contribution therein. These parameters are considered to be of relevance in particular in the growing of particular crops or plants, as explained elsewhere in this document.

EXAMPLE 2 - Silver-based 1 DF and 2DF composites using water

The same apparatus and method as in Example 1 was used, except for the changes described in this section. The same flows of argon as in Example 1 were installed, and the same targets were used in all the sputtering chambers. Also the same power levels were provided to the magnetrons as in Example 1 .

Once the target vacuum pressures were obtained and stable, towards each one of vacuum chambers 2 and 4 was installed a flow of water vapour, which resulted in an increase of the pressure in the particular vacuum chamber, which is believed to correspond to the rate of addition of water towards the chamber. The flow of water was controlled such that in each chamber a pressure increase of 3 . 10^-4 mbar was obtained, which is believed to be partial pressure of water that has become established in each chamber.

The flow of water was controlled by a manual dosing valve with a digital position indication. The position indication corresponds to a volumetric gas flow number by means of an air flow curve that is provided by the supplier of the dosing valve for a pressure difference of 1 bar, and which may be converted to the actual gas flow by correcting the air flow at 1 bar for the actual pressure drop over the dosing valve. The digital position indication was set at 700 which corresponds to a water vapour flow in the range of 50-150 seem towards each of the vacuum chambers 2 and 4.

After 4.5 hours of operation producing this 1 DF composite, the transmittance spectrum 200923C85 of Figure 1 was registered.

The first production run in this example was also continued until the PET film was completely unwound from the unwinding roll in the unwinding chamber, and wound in the winding chamber. The coated film was also again rewound back onto the unwinding roll and the film was passed a second time through the same apparatus to produce a corresponding 2DF composite. The second run for producing the 2DF composite commenced after reclosing the apparatus, the starting up thereof and a period of 9 hours of vacuum pumping in order to assure stable pressure conditions. During the second pass, the same powers as in Example 1 were provided to the respective magnetrons in the corresponding vacuum chambers and subchambers:

The same water addition rates were applied as during the first production run of this example 2, such that a 2DF composite was formed in which both sets of layers in the composite were deposited under similar conditions in the atmospheres in vacuum chambers 2 and 4. The production run resulted in a 2DF composite product of which the transmittance spectrum 20024C84 shown in Figure 1 was registered. For the spectra 200923C85 and 20024C84 were calculated the same parameters as for the other spectra in example 1 . These results are shown in Table 2.

Table 2

The results in Table 2 show that the 1 DF composite may already achieve a significant reduction in the transmission of radiation in the near-infrared range (TJR), in the ultraviolet range (T UV) and in the solar direct transmittance (T soi), while the composite still shows an extremely high VLT, meaning that the human eye would not at all notice the presence of the composite, and an extremely high T PAR, meaning that plants and/or crops would still receive the portions of the solar spectrum that are beneficial and/or needed for their growth and evolution. The 2DF composite shows extremely strongly reduced parameters TJR, T LIV and T soi, while VLT and a high T PAR remain high. The applicants have surprisingly found that also the presence of the 2DF composite produced in this way would still pass unnoticeable for the human eye.

The colour transmission ratios T blue / T red as given in Table 2 show that the 1 DF composite only slightly enhances the red light over the blue light contribution in the transmitted spectrum, while the 2DF composite enhances the red light contribution to a larger extent relative to the blue light. The colour transmittance ratios T far red / T red show that the far red towards the red light contribution for the 1 DF composite has hardly changed, while with the 2DF composite the far red light contribution reduces relative to the red light contribution.

The results for the colour difference for the two composites demonstrate that the transmitted radiation shows only a negligible colour deviation that would not be noticeable to the human eye, meaning that both the transmitted light and the light reflected by the composite would be experienced by the human eye as being fully “colour neutral”. This means that the composites would not exhibit any colour deviation that would divulge the presence of the composite to a human observer. This further confirms that the naked eye of a human observer would not notice the presence of the composite.

This example demonstrates that the present invention is able to change the relative importance of blue and/or far red light in the transmitted spectrum relative to the red light contribution, and this without even having to incur a change in the colour aspects of the composite. These parameters may e.g. be important in the growing of particular crops or plants, as explained elsewhere in this document.

EXAMPLE 3 - Silver-based 2DF composite with more oxygen The same apparatus and method as in Example 1 was used, except for the changes described in this section. The same flows of argon as in Example 1 were installed, and the same targets were used in all the sputtering chambers. The magnetrons in the vacuum chambers were provided with the following powers, expressed in kilowatt (kW).

Once the target vacuum pressures were obtained and stable, towards each one of vacuum chambers 2 and 4 was installed an oxygen flow of 24 seem per chamber. The transmittance spectrum of the composite under production was not registered.

After the first production run in this example 3, the coated film was rewound back onto the unwinding roll and the film was passed a second time through the same apparatus using slightly different conditions.

During this second run, the oxygen additions were raised to 30 seem to each of the vacuum chambers 2 and 4. The production run resulted in a 2DF composite product with reference 210715C164, of which the transmission spectrum with that reference shown in Figure 3 was registered. For the spectrum of composite 210715C164 were calculated the same parameters as for the other spectra in example 1 . These results are shown in Table 3.

Table 3

The results in Table 3 show that this 2DF composite may achieve an extremely high reduction in the transmission of radiation in the near-infrared range (TJR), in the ultraviolet range (T_UV) and in the solar direct transmittance (T soi), while the composite still shows a reasonably high VLT, meaning that the human eye would not readily notice the presence of the composite, and a reasonable T PAR, meaning that plants and/or crops would still receive the portion of the solar spectrum that is beneficial and needed for their growth and evolution.

Considering the colour transmission ratios T blue / T red in Table 3, this 2DF composite only slightly enhances the red over the blue light contribution. The colour transmission ratio T far red / T red shows that the far red towards the red light contribution is reduced.

The results for the colour difference of this composite demonstrate that the transmitted radiation shows only a minor colour deviation. This composite would thus be experienced by the human eye as being almost “colour neutral” in transmittance. This means that the composites would not exhibit any colour deviation that would divulge the presence of the composite to a human observer. This further confirms that the naked eye of a human observer would hardly notice the presence of the composite.

EXAMPLE 4 - Silver based 1 DF composite without oxygen

The same apparatus and method as in Example 1 was used, except for the changes described in this section. Vacuum chambers 2 and 4 were each provided again with a suboxide TiOx sputtering target in which X was in the range of 1 .6 to 1 .9.

In vacuum chamber 3 were provided a sequence of 3 sputtering targets: target 1 was an alloy made of 80%wt of nickel with 20%wt of chromium, target 2 was made of silver and target 3 was an alloy made of 50%wt of indium with 50%wt of antimony. The magnetrons in the vacuum chambers were provided with the following powers, expressed in kilowatt (kW).

No additional flow of oxygen was installed towards the vacuum chamber 2 and towards the vacuum chamber 4.

The production run thus resulted in a 1 DF composite product with reference 200128C1510, of which the transmittance spectrum that is shown in Figures 1 and 3 was registered.

For the spectrum of composite 200128C1510 were again calculated the same parameters as for the other spectra in example 1 . These results are shown in Table 4.

Table 4

The results in Table 4 show that this Ag -based

1 DF composite may achieve a high reduction in the transmission of radiation in the near-infrared range (TJR), in the ultraviolet range (T JV) and in the solar direct transmittance (T soi). In spite of these properties, the composite has still a high VLT, meaning that the human eye is expected to not notice the presence of the composite, and also the T PAR remains high which makes the composite especially of interest for plants and/or crops in moderate climate bands.

The colour transmission ratios T blue / T red in Table 4 show that this Ag-based 1 DF composite only slightly enhances the red over the blue light contribution. The colour transmission ratio T far red / T red shows that the far red towards the red contribution is somewhat reduced.

The results for the colour difference of this composite demonstrate that the transmitted radiation shows only a very small colour deviation. This is expected to be experienced by the human eye as being a neutral colour in transmittance. This further confirms that the naked eye of a human observer is not expected to notice the presence of the composite.

EXAMPLE 5 - Copper/silver based 1 DF composite with oxygen

In vacuum chamber 3 were provided a sequence of only 2 sputtering targets: target 2 was made of silver and target 1 was made of copper. The magnetrons in the vacuum chambers were provided with the following powers, expressed in kilowatt (kW).

Once the target vacuum pressures were obtained and stable, towards the vacuum chamber 2 was installed a flow of oxygen of 20 seem and towards the vacuum chamber 4 was installed a flow of oxygen of 15 seem. The production run thus resulted in a 1 DF composite product with reference 210217C96, of which the transmittance spectrum that is shown in Figure 3 was registered.

For the spectrum of composite 210217C96 were again calculated the same parameters as for the other spectra in example 1 . These results are shown in Table 5.

Table 5

The results in Table 5 show that this Cu/Ag - based 1 DF composite may achieve an extremely high reduction in the transmission of radiation in the near-infrared range (TJR), in the ultraviolet range (T_UV) and in the solar direct transmittance (T soi). The composite also shows a quite strong reduction in VLT, meaning that the human eye is expected to readily notice the presence of the composite, and also the T PAR is strongly reduced which make the composite especially of interest for plants and/or crops in very sunny regions and hot climate bands.

The colour transmission ratios T blue / T red in Table 5 show that this Cu-Ag 1 DF composite strongly enhances the red over the blue light contribution. The colour transmission ratio T far red / T red shows that the far red towards the red contribution is somewhat reduced.

The results for the colour difference of this composite demonstrate that the transmitted radiation shows a major colour deviation. This is expected to be experienced by the human eye as being a red colour in transmittance. This further confirms that the naked eye of a human observer is definitely expected to notice the presence of the composite.

EXAMPLE 6 - Aluminium-based 1 DF composite using oxygen

In vacuum chamber 3 was provided only one sputtering target which was made of aluminium.

The magnetrons in the vacuum chambers were provided with the following powers, expressed in kilowatt (kW).

Once the target vacuum pressures were obtained and stable, towards the vacuum chambers 2 and 4 was installed a flow of oxygen of 24 seem each.

The production run resulted in a 1 DF composite product with reference 211005C131 of which the transmittance spectrum was registered and shown under that reference in Figure 3. For the spectrum 211005C131 were again calculated the same parameters as for the other spectra in example 1 . These results are shown in Table 6.

Table 6

The results in T able 6 show that this Al-based 1 DF composite may achieve a high reduction in the transmission of radiation in the near-infrared range (TJR), in the ultraviolet range (T JV) and in the solar direct transmittance (T soi). The composite shows still a reasonable high VLT, meaning that the human eye will not readily notice the presence of the composite. The T PAR is somewhat reduced which make the composite of particular interest for growing plants and/or crops in sunny regions.

The colour transmittance ratios T blue / T red in Table 6, this Al-based 1 DF composite strongly enhances the blue over the red light contribution. The colour transmission ratio T far red / T red shows that the far red towards the red light contribution is only moderately reduced.

The results for the colour difference of this composite demonstrates that the transmitted radiation shows a colour deviation. This is expected to be experienced by the human eye as being a blue colour in transmittance. This further confirms that the naked eye of a human observer would be expected to notice the presence of this composite.

EXAMPLE 7: GREENHOUSE TEST UNDER CLEAR GLASS.

A full roll of a 1 DF composite obtained as a result of a full production run operating under the conditions as explained in Example 4 above with reference 200128C1510 was produced. It therefore should be exhibiting the transmittance spectrum shown in Figure 1 and 3 under that reference. That 1 DF composite was used in a greenhouse test for growing lettuce. The composite was for that purpose by lamination further provided with an adhesive layer having a thickness of about 1 .5 pm on top of the coated side of the PET film. This adhesive layer was further protected with a release liner. As release liner was used a PET film having a thickness of about 25 pm (“1 mil” or 1 /1000^th of an inch in US units) carrying a silicone release coating made from a tin catalysed silicone release agent and showing a release characteristic of about 10 grams per inch. At the other side of the coating, the PET film was protected by a hardcoat, having a thickness in the range of 5 to 10 pm, to improve the scratch resistance of the composite. The hardcoat was applied using a conventional reverse gravure coating technique.

The adhesive used for the adhesive layer was a Clear Dry Adhesive (CDA) made from (meth)acrylic acid obtained under the tradename Loctite DURO-TAK 109A from the company Henkel (DE). The CDA contained benzotriazole as UV absorber in order to provide protection of the adhesive layer against deterioration cause by sunlight. For the hardcoat was used a urethane (meth)acrylate compound available under the tradename Shiko UV-6300B from the company Nippon Synthetic Chemical Industry Co., Ltd (JP) and a hardcoat agent obtainable under the tradename PET-D31 from the company Dainichiseika Kogyo Co., Ltd (JP). The test of the composite occurred in a glass greenhouse in The Netherlands. A series of three adjacent and further identical greenhouses (numbered 1 , 2 and 3) were dedicated to the test. The greenhouses had each a floor area of 525 m², their roof consisted of clear flat glass having a thickness of 4 mm. For ventilation of the greenhouse and as part of the temperature control, roof windows could be opened by the fully automated building control system. Monitoring included the measurement of temperature, humidity and other conditions in the greenhouse, such as concentrations of water and CO2. Other measuring equipment available and used included a Licor 6800 Portable Photosynthesis System, a Licor Li-180 Spectrometer (380 nm - 780 nm), a Licor LI-190R Quantum Sensor (400 nm - 700 nm), and Apogee UV-A SU-200-SS UV Sensor (300 nm - 400 nm) and a set of Apogee PQ-141 PAR-FAR Sensors (389 nm - 692 nm, 702 nm - 761 nm).

The 1 DF composite was installed in greenhouse #3 by removing the release liner and fixing the composite by means of its adhesive layer against the entire inner surface of the flat glass roof of the greenhouse.

The optical parameters given in Table 7 were determined for the composite as this was used in the test. The VLT reported in Table 7 is slightly lower than of the composite as produced in Example 4 because of the extra adhesive layer and hardcoat that had been added, and which were not yet present when the spectrum in Example 4 and shown in Figure 1 and 3 was registered.

Table 7

Lettuce was selected as the test crop, because lettuce can grow very quickly and without much extra handling. The species tested was Appia, a large lettuce with tender leaves for the whole season. Pots having a diameter of 19 cm and a height of 20 cm were filled with identical potting soil prepared by mixing together 0.55 m³ of Baltic white peat “fine”, 0.40 m³ of frozen black peat, 0.05 m³ of perlite 2, 4.70 kg of lime, 1 .00 kg of T ref Base Fertilizer (TBF) and 0.25 kg of a water retention agent. The TBF fertilizer was obtained as TBF 17-10-14-4, thus comprising about 17% nitrogen, 10% phosphorus as P2O5, 14% potassium as K₂O, supplemented with 4% magnesium oxide, from the company Agro Imperium (Romania), and the water retention agent as granulate wetting agent Fiba Zorb from the company T urftech (UK).

To exclude any influence from soil or seed in the used samples, the samples were germinated from the same batch of seeds, sown at the same time, on 2 July, in identical pots with identical soil, grown the first days in the nursery on site, split and planted at the same time, on 13 July, in identical pots with identical soil, grown further some days in the nursery, and moved to the greenhouses at the same time, i.e. on 17 July. The lettuce test samples were watered every day.

Greenhouse #2 was used as is. Greenhouse #1 was used as one extra comparable case. Due to the high temperatures experienced during part of testing period in the summer of the test, the roof of this greenhouse had been temporarily coated with a white coating, Redusol, a shading agent that reflects high levels of solar energy, in order to reduce the heat inside the greenhouse. This coating was removed on August 20. The conditions in greenhouses 1 and 2 are considered to be quite standard conditions in The Netherlands.

After installing the composite in greenhouse #3, 45 lettuce labelled test samples were put into each of the 3 greenhouses. The samples were located in the middle of each greenhouse (15 pieces), and on 2 locations (2 x 15 pcs) near the south fagade of each greenhouse, where the sun radiation could be captured in the early morning till late in the afternoon. The greenhouse environment was characterised by that no cooling or heating was made available, none of the shading screens were active, and by that the opening of the windows was steered by the automated control system in function of the attempt to maintain the temperatures in the 3 greenhouses within the same limits.

The exposure in the greenhouses thus started on 17 July. The test was continued up to 30 September, when a part of the plants were harvested for crop dimensioning, and further continued up to 12 October, when further crop dimensioning was performed. End of July and up to about the middle of August, a heat wave hit The Netherlands, during which the outside temperature at the test site reached 30°C or more. Due to these high temperatures, a lot of plants were burned by the radiation in the reference greenhouse 2.

A clear effect could already be observed when comparing the minimum, maximum and average temperatures and relative humidity values registered for the three greenhouses over the day of 13 August, i.e. during the heat wave, as shown on Table 8.

Table 8

The measurements show that the temperature in greenhouse #3 (with the optical filter according to the invention) was lower than in the greenhouse #2 without any optical filter or shading agent. The temperature in greenhouse #3 was typically slightly higher than in the greenhouse #1 with the white coating. This lower temperature was even obtained with less opening of the windows on hot days. This observation already allows to conclude that in case of a cooled greenhouse, the owner could save substantial amounts of cooling energy by using the composite in accordance with the present invention.

In the greenhouse #1 covered with the white coating, we could observe that up to the removal of the shading agent only diffuse light was reaching the lettuce in the pots. Furthermore, it could be observed that the growth of leaves showed a good leaf setting, but less and limp leaf production in comparison to the transparent greenhouse #2 and to the greenhouse #3 with the composite according to the present invention. The leaves showed already within a period of 10 days a change into a darker green colouration, which clearly indicated a shift of the production of initially more chlorophyll A to more chlorophyll B production, and this at an early age stage. This indicates that the plants were early in coming into a more mature phase of their development. Furthermore, we could observe already after 20 days that the first plants were showing a tendency to produce flower stems, meaning they were stretching in an attempt to seek more light. This further extended at the third week of naked eye observation into nearly all plants flowering. For lettuce as a commercial product, the light green colour of Chlorophyll A is by far preferred over the darker green, and the plant should not yet have started flowering.

In the reference greenhouse #2 with transparent single float glass, we could observe a high radiation damage on the plants. Many lettuces in pots showed necrosis and even completely dried leaves. Most of the plants died due to extreme radiation and the existing high temperature inside, which went many times above the 40°C according to the greenhouse air temperature readings. Only few plants remained alive and showed still growth. The colour of the remaining leaves of all lettuce plants was bright green, indicating primarily chlorophyll A production. In addition, we noticed at about 20 days into the test period strong signs of maturity because of increased chlorophyll B production in the leaves and raising stems that eventually resulted in flower stems.

Inside the greenhouse #3 equipped with the composite according to the present invention the visual observation was characterized by a neutral bright light, slightly dimmed as compared with greenhouse #2 as a result of the 77% visible light transmittance (VLT). The lettuce plants in the pots all thrived very well from the germination till full grown plants and continued to show a healthy and light green leaf colouration. This means that chlorophyll A production remained predominant in the leaves at least during the full first 20 days and the leaves developed in an optimal condition. Remarkable was that the leaves all showed a large size dimension and resulted in a significantly higher yield of biomass production, clearly visible in the production of the total leaf amount and the size of all lettuce plants in comparison with both other greenhouses. After 20 days the plants started to show the first signs of flowering as could be observed in more erect stem formations that eventually turned into flower heads.

The success in greenhouse #3 is surprising in view of the conventional wisdom that for obtaining sufficient photosynthesis the plants need to see as much as possible of the visible light that is available, while the VLT in greenhouse #3 was below 80%, which is a reduction that is not negligible.

In greenhouse #1 , with the shading agent, the plants showed clear signs of stretching. These plants were clearly searching for more light energy. In greenhouse #2, many plants showed very clear signs of ageing and often also necrosis. In a commercial setting, the plants showing necrosis would have completely lost their commercial value.

In addition to above visual observations, some of the test results were also quantified by crop dimensioning. With lettuce the most important parameter is biomass generation, and the amount of biomass generated by an individual plant may be expressed in two ways: as the total weight of biomass gained over a particular time interval, and/or as the amount of total produced leaf area.

The comparison was limited to greenhouses #2 and #3. Greenhouse #1 was excluded from the plant dimensioning because the shading agent had been removed after the heat wave, so the plants had been exposed to two different conditions.

For the biomass tests, two plants were selected as being most representative specimen for all the lettuce plants in each greenhouse. The plants were selected amongst those still in the vegetative growth phase and thus suitable for a comparison of biomass production and total leaf area. Tests were performed on plants selected on 30 September and on 12 October. The results are summarized in Table 9. Measured were the number of leaves, of each leave the surface area expressed in square cm. The sum of all leave area for each lettuce plant is shown in Table 9, as well as the number of leaves counted. Further measured for the first harvest was the weight of biomass of the entire plant.

Table 9

The results of the early test show not yet a significant difference. The results of the later test however show a significant increase by more than 50% of the leaf area in favour of the present invention.

Spectrometer measurements showed a number of other remarkable differences: The composite according to the present invention (in Greenhouse #3) is able to reduce the exposure to UV-radiation down to 4% of what it was in the comparative test (Greenhouse #2). The blocking of infrared radiation by the composite according to the present invention was considered almost complete, resulting in that the radiation in that wavelength range adds hardly any heat generation inside the greenhouse and hence does hardly add to the plant stress. These spectrometric observations were supported by no occurrence of any leaf burning or sings of necrosis in greenhouse #3, while many plants in greenhouse #2 had been affected severely.

The following conclusions could thus be drawn from this greenhouse test as benefits that are brought by the composite according to the present invention: • much easier temperature control inside the greenhouse during very hot seasons. The (temporary) use of a shading agent may be dispensed with, which brings further benefits because the associated improved quality and quantity of light exposure is able to bring a significant leaf area production, as evidence with the lettuce model. Also the negative effects of a shading agent, i.e. the risk for plant stretching and premature aging and flowering, may be avoided.

• Less cooling of greenhouses is required, which brings energy savings and a reduction in carbon footprint.

• A reduced water consumption. The plants in the greenhouse with the composite according to the present invention need much less evapotranspiration in order to keep cool, and hence have a lower water demand during their nursing and development.

• Photosynthesis was apparently improved, as witnessed by the leaf area increase - and hence crop production increase - using the lettuce model.

• Leaf temperature measurements showed no stress in the plants underneath the film coated glass roof. Many plants positioned underneath the non-coated glass roof showed clear signs of necrosis as a result of extreme heat exposure. This benefit in a commercial setting would directly convert into a much higher yield of commercially useful products, thanks to the protection brought by the extra film coating containing the dichroic filter(s).

EXAMPLE 8: GREENHOUSE TEST UNDER DIFFUSED GLAZING.

A second greenhouse test was arranged in a town in the northern half of Germany. Dedicated for the tests were 2x2 greenhouse chambers. Two chambers (#4 and #5) had single non-flat diffused glazing of the puckered type, thickness 4 mm. These chambers were equipped with a cooling system having a limited capacity. Its windows could be opened as needed by the automated building control system. These chambers were used for Example 8A. Two other chambers (#6 and #7) had double flat diffused glazing. It also had a cooling system, this time with a higher capacity. This cooling system was however only used during a few days at the start of the test. It was switched off during the rest of the test period. These chambers were used for Example 8B. All chambers were provided with shading screens and were controlled by the building automation system.

A full roll of a 2DF composite obtained as a result of a full production run operating under the conditions as explained in Example 2 above with reference 200924C84 was produced. The composite that was used in this Example 8 exhibited the properties listed in Table 10. It was further equipped and subsequently fixed against the roof of the greenhouse chamber in the same way as in Example 7.

Table 10

The same lettuce crop as in Example 7 was used in Example 8. As soil was used standard soil ED73 with slow release fertilizer known as the fine substrate or “Lents substrate”, which is obtainable under the reference “ED73” from the company Lentse Potgrond BV (NL). The test period went from August until November.

The greenhouse chamber environment in Example 8A was characterised by limited adiabatic cooling with opening of the windows when the temperature became too high inside the chamber. The shading greens were kept inactive. The building automation system controlled and steered cooling and opening of the windows in function of the attempt to maintain the temperatures in the 2 chambers within the same limits. To exclude any influence from soil or seed in the used samples, also in the experiments of Example 8A the samples were germinated from the same batch of seeds, sown at the same time, on 4 August, in identical pots with identical soil, grown the first days in the nursery on site, split and planted at the same time, on 14 August, in identical pots with identical soil, grown further some days in the nursery, and moved to the two chambers at the same time, i.e. on 3 September. The lettuce test samples were watered every day.

Ten (10) lettuce test samples were put on a mobile table in the middle of both greenhouse chambers (20 in total). The chambers lay at the south side of the greenhouse complex, so that the test samples could enjoy sun radiation from early in the morning until late in the afternoon.

For Example 8B the greenhouse environment was characterised by no active cooling. The shading greens were again kept inactive. The building automation system controlled and steered the opening of the windows in function of the attempt to maintain the temperatures in the 2 chambers within the same limits. Adjacent to these greenhouse chambers were other chambers connected and equipped with artificial additional lighting. The test samples were positioned as far as possible from this artificial lighting in order to prevent any impact thereof. The chambers lay at the south side of the greenhouse complex, so that the test samples could enjoy sun radiation from early in the morning until late in the afternoon.

To exclude any influence from soil or seed in the used samples, also in the experiments of Example 8B the samples were germinated from the same batch of seeds, sown at the same time, on 4 August, in identical pots with identical soil, grown the first days in the nursery on site, split and planted at the same time, on 14 August, in identical pots with identical soil, grown further some days in the nursery, and moved to the two chambers at the same time, i.e. on 4 September. The lettuce test samples were watered every day.

In addition to the lettuce plants, in this Example 8B Soybean plants were placed next to the lettuce plants, and exposed to identical nursing conditions as the lettuce plants. In Example 8, also energy consumption measurements were made during four 10-day periods. During September and October cooling appeared necessary, and in November heating proved necessary. Over the full day of October 13, the comparative greenhouse chamber consumed 7.674 kW for cooling, while the greenhouse with the composite according to the present invention consumed only 4.575 kW. This represents an energy saving of 40% in favour of the present invention. The applicants believe that this is a clear demonstration of the effect brought by the present invention in that the composite according to the present invention is effective in reflecting the heat intensive part of solar radiation, which is primarily situated in the near infrared radiation, but for a part also in the ultraviolet range, and hence reducing the heat input by the incidence of solar radiation into the greenhouse, thereby significantly reducing the energy required for keeping the inside or the greenhouse cooler and thereby more convenient for the crops growing in it.

Over a full 24 hour period from 5 to 6 November, the comparative greenhouse chamber consumed 8.485 kW for heating, while the greenhouse with the composite according to the present invention consumed only 3.581 kW. This represents an energy saving of 58% in favour of the present invention. The applicants believe that this is a clear demonstration of the effect brought by the present invention in that the composite according to the present invention is effective in also reflecting the long infrared radiation. This means that heat radiation originating from inside the greenhouse, which is primarily of the long infrared wavelength, is kept inside the greenhouse rather than lost into the (usually night) environment, thereby significantly reducing the energy required for keeping the inside or the greenhouse warmer during cold, cloudy and/or winter periods, and thereby more convenient for the crops that are being cultivated inside of it.

In Example 8A, all lettuce plants showed a normal growth, but two weeks into the greenhouse chamber the lettuce plants in the chamber with the composite had produced more leaves having a healthy light green appearance. In Example 8B, under the double glass roofs, all plants also showed a normal growth pattern and the leaves had a light green appearance, indicating that Chlorophyll A was predominant. The lettuce plants in the greenhouse chamber with the composite showed a significant increase in leaf development and a larger size of leaves in general.

The soybean plants in Example 8B in the chamber with the composite showed a visibly larger leaf size distribution on all plants, as well as more leaves produced in the same period as compared to the reference plants in the other chamber. The findings on lettuce therefore appear to be more generic and are expected to be applicable to other plant species.

Also crop dimensioning was performed on the lettuce plants grown in Example 8. Four plants were selected as representative samples of the group and still in their vegetative growth phase. For Example 8A the results are given in Table 1 1 .

Table 11

The results show in favour of the present invention a 23% increase in biomass production, a 34% increase in leaf number, and a 23% increase in total leaf area. This represents a significantly better crop yield.

Table 12

For Example 8B the results are given in Table 12. The results show again in favour of the present invention a 37% increase in biomass production, a 33% increase in leaf development, and a 65% increase in leaf area. This again represents a significantly better crop yield.

Spectrometer readings indicated that throughout all tests and in all chambers there was sufficient photo active radiation (PAR) light to enable an optimal photosynthesis in the lettuce crops. However, both the Photosynthesis System readings and the UV sensor readings indicated a lower exposure to UV-A radiation underneath the composite as compared to the reference chamber, and this in both Examples 8A and 8B. This may suggest that the observed differences in performance may be also at least partially due by the UV blocking by the composite according to the present invention.

The readings of the PAR-FAR Sensors confirm that the composite is bringing a reduction to the exposure in the far red till infrared wavelength region and an almost a high protection against the infra-red radiation. This inevitably brings that leaf surfaces reach less extreme temperatures, and it is believed that this does benefit the growth of cell structures.

The spectrometer readings registered an UV radiation of 0.24 pmol m^-2 s^-1 in the reference chamber and at the same moment only 0.05 pmol m^-2 s^-1 in the chamber equipped with the composite. The composite therefore reduces the UV radiation by as much as a factor of 4. In the far red wavelength region (702 nm - 761 nm) the unfiltered radiation was measured as 2.73 pmol m^-2 s^-1 while in the chamber with the composite at the same moment this had been reduced to 1 .76 pmol m^-2 s ¹.

Even more convincing were the comparative spectra that could be registered almost simultaneously by means of the Licor 180 for the exterior of the greenhouse chambers, the chamber 6 without the extra filter, and the chamber 7 with the optical filter. It could be clearly observed that the radiation spectrum available inside chamber 6 was almost unaltered compared to the exterior, while the radiation in chamber 7 showed quite noticeable reductions in the UV wavelength range, and starting in the red light region but becoming more important in the far red till infrared wavelength region.

EXAMPLE 9 - 1 DF composite produced with different levels of water present

The procedure for producing a 1 DF composite from Example 2 was repeated several times, with the following changes. The PET foil of which a roll was installed in vacuum chamber 1 had a thickness of only 23.4 pm. The available end of the foil was brought from the unwinding roll through the entire apparatus and finally attached to the winding roll in the winding chamber 5. The same sputtering targets as in Example 2 were installed in the same locations. After having established the same vacuum pressures as in Example 2, the same flows of argon were installed as in Example 2. The same start-up procedure as in Example 2 was used, and once the target deep vacuum had been reached, the vacuum system was also kept operating for another 12 hours before the production run was started.

The PET film movement was started from the unwinding roll to the winding roll, at a speed of 82.5 cm per minute. The sputtering targets were powered sequentially from sputtering chamber 2 over subchambers 3.1 , 3.2 and 3.3 up to chamber 4. The magnetrons in the vacuum chambers were provided with the following powers, expressed in kilowatt (kW). The magnetrons in chambers 2 and 4 were AC magnetrons, the magnetrons in chamber 3 were all DC magnetrons.

Under the continued admission of Ar, the pressure stabilised at a pressure of about 2 . 10³ mbar. After pressure stabilisation the respective water vapour additions were opened towards the two vacuum chambers 2 and 4, by varying the precision dosing valves in the connections between the respective vacuum chamber and the associated side chamber from the position indication of 400 up to 900. By calibration measurements, this range of valve settings was known to correspond with a flow of water vapour in the range of from 1 .5 up to 660 seem. Relative to the 750 seem of argon (Ar) that still continued to be supplied to each one of the respective vacuum chambers 2 and 4, the water vapour flows thus represented a ratio that was corresponding to the range of from 0.2% up to 88%. The installation of the water vapour flows was such that in each chamber a partial pressure from 5 . 10^-5 mbar to 1 . 10^-3 mbar of water was established in both vacuum chambers 2 and 4 over the previously stabilised pressure in the respective vacuum chambers. After 10 minutes of operation with a water vapour flow of 1 .5 seem, the corresponding transmittance spectrum of Figure 4 was registered. Subsequently the water vapour flow was raised to 8 seem, and after 10 minutes of operation, the corresponding transmittance spectrum of Figure 4 was registered. In the same way, after intervals of 10 minutes and raising the water vapour flow to respectively 32 seem, 100 seem, 275 seem and 660 seem, the corresponding transmittance spectra of Figures 4 and 5 were registered.

For the six 1 DF composites were calculated, based on the collected spectra, the %VLT using the weighing as specified in NEN-EN 410 for the illu minant D65 reference, and, this time using the weighing as specified in NEN-EN 410 for the global solar radiation and normalised for the specified wavelength range, the % transmittance in the range 400-460 nm (T blue), in the range 600-700 nm (T red), and in the range 900-1000 nm (TJR). The results are shown in Table 3. Also the colour differences from the colour of the illuminant D65 was calculated in accordance with ISO 1 1664-4: 2008 in the CIE L*a*b colour space.

The six transmittance spectra ranging from 1.5 seem (230221 C36) to 660 seem (230221 C68), thus using increasing water levels and no oxygen, show in the drawings that the water presence caused significant changes to the transmittance spectrum of the coated PET film. This is also clearly shown by the numbers in Table 3. The transmittance in the NIR range (above 780 nm) significantly increases up to a water vapour flow of 100 seem above of which it again decreases. The transmittance in the visible range (range 380-780 nm) was increasing up to a water vapour flow of 100 seem (Figure 4) above of which it remained practically constant (Figure 5). In the blue range (380-500 nm), the transmittance increases up to a water vapour flow of 100 seem, while in the red range (620-780 nm) the transmittance increases up to a water vapour flow of 100 seem above of which it remains practically constant, and transmittance in the UV range (below 380 nm) increases with increasing the water vapour flow.

Table 3 - 1 DF composite made with increasing water levels

A comparison of the series of numerical results starting from spectrum 230221 C36 (1.5 seem) and up to spectrum 230221 C68 (660 seem) shows that the increase in the water flow addition gave some beneficial effects up to a water vapour flow of about 100 seem. An increasing effect in the near infrared region (TJR), the VLT, T blue and T red is noted up to a water flow of 100 seem. This possible drawback in some applications, i.e. an increased TJR, is however compensated by an almost equivalent increase in the VLT. Above 100 seem of water, the T JR reduces again while the VLT remained very high. The major effect observed is the increase of the colour deviation from the D65 illuminant, which may be less desired in particular enduses. The use of water vapour from 230221 C36 up to 230221 C58 (100 seem) results in a good colour neutrality as illustrated with the very small colour difference with the D65 standard. Higher additions of water, as compared with the addition of 1.5 up to 100 seem, appears to deliver a less good colour neutrality while maintaining a high VLT.

The different transmission spectra as obtained in this example are shown in Figures 4 and 5. Different from Figures 1 -3, the ordinate scales in Figures 4 and 5 are now only showing the range of 50-85%.

In Figure 4 are shown the spectra for the water flows starting from 1.5 seem up to 100 seem (composites 230221 C36 up to 230221 C52). In Figure 5 are shown the spectra for the water flows of 100 seem and higher (composites 230221 C58 through 230221 C68). The observations that are made above based on the numerical results are all clearly illustrated in Figure 4 and Figure 5.

Figure 4 shows that the 100 seem composite (230221 C58) provides significant gains over the composites (230221 C36 up to 230221 C52) that were made with less water, in the transmittance in the range of 600-700 nm (i.e. the red light range). This result may be particularly desired in greenhouse agriculture, e.g. for improving the rates of biomass growth, flowering and the setting and development of fruit. The increased transmittance in that same range also brings as associated effect a reduced reflection of the red light, such that the composite gives a reflection that is less red, an effect that may be desired in other applications such as buildings and vehicles. Table 3 also shows that the colour difference hardly changes and remains about unchanged, and hence fully neutral, for the composites in this range.

Figure 5 illustrates that, as the water flow is further increased above 100 seem (up to 30% and above, expressed as a molar ratio relative to the inert gas flow), that the T_IR becomes reduced, but the transmission in the LIV range (below 380 nm) is raised further. These two observations are again a reflection of the “shifting to the left” of the transmission spectrum, now by an increased presence of water, in this example as part of a no-oxygen comparison. While the VLT as a global parameter is maintained high at the higher water levels of 100 seem or above, the spectra demonstrate, in spite of the further gain in the UV range, a significant drop of the transmission in the blue range (below 500 nm), which was already observed in the numbers for T blue and its ratio to the T red in Table 3, which is then compensated by further gains in the higher visible wavelengths of green-yellow light, an effect that appears to have disappeared and reversed when one moves further up into the far red light range (700-780 nm), where the transmission is actually reduced. This last effect may be desired in some applications, such as in agriculture, because of the possible harm that the far red light may bring. Figure 5 thus in a way also shows, as the amount of water is further increased above 30% relative to the inert gas flow, that the composite starts to develop a colour which may show up primarily in the reflected light, noticeable in some applications, but possibly also in the transmitted light, which may thus cause significant effects in other applications, such as in agriculture.

Having now fully described this invention, it will be appreciated by those skilled in the art that the invention can be performed within a wide range of parameters within what is claimed, without departing from the scope of the invention, as defined by the claims.

Claims

1. Use of a composite of a transparent support further comprising, adhered to one side of the transparent support, at least one dichroic filter (DF) whereby the filter comprises at least one metal layer that is sandwiched in between two layers of dielectric inorganic metal oxide, compound or salt, and whereby the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

• a transmittance ratio of T_IR / T soi of at most 120%, wherein T_IR is the near-infrared transmittance in the wavelength range from 900 to 1000 nm, with the relative spectral distribution of the global solar radiation used as weighting function and whereby the weighting factors were normalised over the specified wavelength range, and wherein T soi is the solar direct transmittance, characterised in that the use is in agriculture for the control of solar radiation that is allowed into an agricultural enclosure, and/or for the reduction of the radiation emitted from the enclosure towards its environment.

2. The use according to claim 1 wherein the metal layer contains at least one metal selected from the group consisting of silver (Ag), titanium (Ti), copper (Cu), gold (Au), platinum (Pt), palladium (Pd), aluminium (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), vanadium (V) or stainless steel.

3. The use according to claim 1 or 2 wherein the ratio T_IR / T soi is at least 5%.

4. The use according to any one of the preceding claims wherein the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

• a visible light transmittance (“VLT”), weighted as for the illuminant D65 reference, of at least 50%.

5. The use according to the preceding claim wherein the visible light transmittance (“VLT”) is at most 85%.

6. The use according to any one of the preceding claims wherein the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

7. The use according to the preceding claim wherein the VLT / T soi is at most 250%.

8. The use according to any one of the preceding claims wherein the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

9. The use according to the preceding claim wherein the T PAR / T soi is at most 214%.

10. The use according to any one of the preceding claims wherein the composite exhibits the following emissivity characteristics established in accordance with Industry Standard EN 12898- 2001 ,

• a total corrected emissivity £ at 283 K of at most 0.90.

11 . The use according to the preceding claim wherein the total corrected emissivity £ is at least 0.05.

12. The use according to any one of the preceding claims wherein the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

13. The use according to the preceding claim wherein the ratio T_UV / T soi is at least 2%.

14. The use according to any one of the preceding claims for obtaining at least one of the following effects:

• a reduction of the energy consumption associated with maintaining, inside an agricultural enclosure, of a temperature within a range that is convenient for the animals, crops or plants inside the enclosure,

• an improvement in the effectiveness and efficiency of photosynthesis,

• the reduction of the crop cycle in plant cultivation,

• the reduction of stress experienced by animals, crops and/or plants in an agricultural enclosure,

• the reduction of the risk for the burning of crops and/or plants under the exposure to solar radiation, preferably the reduction of the risk that crops and/or plants exhibit necrosis,

• the reduction of the radiation energy that is directly reaching animals, crops and/or plants under the exposure to solar radiation, • reducing the direct exposure of animals, crops and/or plants to the near infrared radiation under the exposure to solar radiation, wherein near infrared is the radiation in the wavelength range from 780 up to 2500 nm,

• reducing the direct exposure of animals, crops and/or plants to the harmful part of UV A and/or UV B radiation under the exposure to solar radiation, wherein UV A is the radiation in the wavelength range from 315 to 380 nm, and UV B is the radiation in the wavelength range from 280 to 315 nm, and

• an increase of carbon storage in crops and/or plants.

15. The use according to any one of the preceding claims wherein the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

• a transmission ratio of T Far Red / T Red of at most 100%, wherein “T Red” is the weighted average transmittance in the red wavelength range from 600 to 700 nm, weighted for the relative spectral distribution of the global solar radiation and the weighting factors normalised over the specified wavelength range, and “T Far Red” is the weighted average transmittance in the far red wavelength range from 700 to 760 nm, weighted for the relative spectral distribution of the global solar radiation and the weighting factors normalised over the specified wavelength range.

16. The use according to any one of the preceding claims wherein the ratio of (T Far Red / T Red) is at least 10%.

17. The use according to any one of the preceding claims wherein the composite exhibits the following transmittance characteristics established in accordance with Industry Standard NEN-EN 410,

18. The use according to any one of the preceding claims wherein the ratio of T BIue / T Red is at most 200%.

19. The use according to any one of the preceding claims of the composite, either solely as, or in combination with, a cover for use in agriculture that allows the transmittance of part of the solar radiation, preferably as a component of the cover of an enclosure such as an animal shelter or stable, a greenhouse or a polytunnel structure.

20. The use according to any one of the preceding claims for obtaining at least one of the following effects:

21. The use according to any one of the preceding claims for limiting the average global horizontal irradiation (GHI) from the sun to at most 7.4 kWh/m²/day or 2701 kWh/m²/year.

22. The use according to any one of the preceding claims wherein at least one layer of the transparent support of the composite, preferably the layer that is facing the plants and/or crops, exhibits the following reflectance characteristics established in accordance with Industry Standard NEN-EN 410

• a visible light reflection (“VLR”), weighted as for the illuminant D65 reference, of at least 5%, preferably at least 10%.

23. The use according to the preceding claim wherein the layers of the dichroic filter are deposited sequentially onto the transparent support using sputter-deposition in at least one sputtering chamber.

24. The use according to the preceding claim wherein the process for the production of the composite comprises, in the sputtering chamber where the at least one of the dielectric layers is sputtered, the introduction of at least one inert gas and water.

25. The use according to the preceding claim wherein, in the sputtering chamber in which the at least one of the dielectric layers is sputtered, a partial pressure of water is maintained in the range of at least 0.00001 mbar and 0.0015 mbar.

26. The use according to the preceding claim wherein the molar flow of the water that is introduced into the sputtering chamber is in the range of 1% to 30% relative to the total molar flow of inert gas that is introduced into the same sputtering chamber.

27. The use according to any one of claims 23-26, wherein, into the sputtering chamber in which the at least one of the dielectric layers is sputtered, oxygen is introduced as a reactive gas.

28. The use according to the preceding claim wherein the molar flow of the oxygen that is introduced is controlled in the range of 0.1% to 20% relative to the total molar flow of inert gas that is introduced into the same sputtering chamber.

29. The use according to the any one of the preceding claims wherein the dichroic filter further comprises at least one intermediate layer located between the dielectric layer and the metal layer, preferably the filter comprising one intermediate layer on both sides of the metal layer.

30. The use according to the preceding claim wherein the intermediate layer comprises at least one of the metals or alloys from the group consisting of gold, silver, palladium, platinum, palladium, ruthenium or another precious or platinum group metal, nickel, nickel alloyed with chromium, indium, gallium, antimony, arsenic, aluminium, antimony and/or arsenic together with indium and/or gallium, indium antimonide, gallium antimonide, indium gallium antimonide, indium arsenide, gallium arsenide, indium gallium arsenide and indium aluminium arsenide.

31. The use according to any one of the preceding claims wherein the dielectric layer comprises at least one non- metallic material that is transparent to both visible and infrared radiation.

32. The use according to any one of the preceding claims wherein the process for the production of the composite further comprises the step of applying directly on the dichroic filter a protecting film consisting of another flexible film, an acrylate wet coating or a wet coating applied by a method comprising the application of a sol-gel technique.

33. The use according to the preceding claim wherein the process for the production of the composite further comprises the step of providing an adhesive layer on at least one side of the transparent support of the composite.

34. The use according to any one of the preceding claims wherein the process for the production of the composite further comprises the step of providing a hardcoat layer on one side of the transparent support.

35. The use according to any one of the preceding claims wherein the transparent support has a shear modulus at room temperature of at least 0.5 GPa and at most 80 GPa, meaning the support is qualified as being “rigid”.

36. The use according to the preceding claim wherein the transparent support is one glass layer of laminated glass, the method further comprising the assembly of the laminated glass.

37. The use according to the preceding claim wherein the laminated glass is used in the construction of a building, in a greenhouse, an animal shelter or stable.

38. The use according to any one of claims 1 - 34 wherein the transparent support has a shear modulus at room temperature typical of a flexible material, meaning that the shear modulus is in the range of at most 0.5 GPa and at least 0.1 MPa.

39. The use according to any one of the preceding claims wherein the composite is used in at least one of the following forms:

40. The use according to any one of the preceding claims wherein the composite is used as an element of a greenhouse, a polytunnel, an open-field canopy, an animal shelter or a stable.