Film for agricultural structures

Abstract

To provide an improved film for covering agricultural structures that maintains excellent mechanical properties and recyclability while exhibiting low susceptibility to photodegradation in the presence of pesticides and good barrier properties against oxygen. [Solution] The present invention provides: (a) a polymer film having one or more layers, wherein at least one of the layers contains one or more UV stabilizers; and (b) a coating on at least one outer surface of the polymer film, wherein the film has a UV resistance of 500 ml / m² at 23°C and 0% relative humidity when measured according to EN ISO 15105-2. 2 The present invention relates to a film for covering agricultural structures, comprising a coating including at least one layer containing a polymer, having an oxygen permeability of less than / bar / day.

Description

[Technical Field]

[0001] The present invention relates to polymer films for covering agricultural structures and methods for producing such films. The present invention also relates to the use of a coating on at least one outer surface of a polymer film as a barrier against gases and water vapor, and for reducing the film's susceptibility to photodegradation in the presence of pesticides. [Background technology]

[0002] Agricultural structures are often covered with flexible films containing polymer materials for various purposes. For example, greenhouses can be covered with polymer films tailored to provide a favorable environment for cultivating crops and plants. Polymer films protect the crops grown beneath them from adverse weather conditions and create a greenhouse effect by selectively filtering solar radiation.

[0003] Polymeric materials used in films, such as copolymers of polyethylene, ethylene vinyl acetate (EVA), and ethylene butyl acrylate (EBA), absorb ultraviolet radiation, resulting in photodegradation of the film and thus shortening its lifespan. For this reason, ultraviolet (UV) stabilizers are usually added to polymeric film materials. UV stabilizers function by absorbing ultraviolet radiation and thereby preventing its absorption by the film's polymer (as UV absorbers), or by inhibiting chemical reactions that lead to photodegradation (as free radical scavengers).

[0004] UV absorbers have two drawbacks that prevent them from adequately protecting polymers: (a) UV absorbers are usually small molecules and gradually migrate to the film surface and are lost to the surroundings; (b) UV absorbers cannot adequately protect the film surface because, according to the laws of physics (Lambert-Beer's law), they require a certain depth to act as UV filters. For this reason, so-called HALS (hindered amine light stabilizers) have become popular as the main stabilizers for greenhouse films over the past 20 years. HALS are sterically hindered amine compounds that act as free radical scavengers, reacting with free radicals formed in polymers under the influence of oxygen, ultraviolet radiation, and heat. This stops the chemical reaction, otherwise leading to chain breakage or crosslinking of polymer molecules and degradation of the film's physical and optical properties.

[0005] HALS has proven to be a highly effective stabilizer in many applications. However, in the case of greenhouse films, there are serious limitations that lead to a reduction in its effectiveness: pesticides are widely used inside greenhouses for soil disinfection and plant protection. These pesticides decompose under the influence of heat and ultraviolet radiation, and further penetrate the film in gaseous or vaporous form, producing activating compounds that react with HALS and inactivate it. In particular, sulfur, as well as sulfur and chlorine-containing compounds, can lead to a very significant reduction in the lifespan of greenhouse films containing HALS, for example, from 3-5 years to 1-2 years in the Mediterranean.

[0006] In recent years, greenhouse film manufacturers and professional organizations (e.g., CEPLA, Spain) have imposed restrictions on the sulfur and chlorine content in films to ensure manufacturers' service life guarantees and prevent premature degradation. Nevertheless, the use of pesticides in greenhouses to prevent various crop diseases is unavoidable and even increasing, so the main challenge today in improving the quality of polymer films is to avoid premature degradation caused by pesticides.

[0007] Various solutions have been proposed to address this problem. One suggestion is to use a nickel complex that is completely resistant to sulfur as a stabilizer. However, this is sensitive to chlorine and gives the film a yellow color, which is undesirable as it reduces light transmission. Another proposed solution is to use an auxiliary stabilizer that reacts with and inactivates the active residue of the pesticide, but this has proven insufficient. A further solution is to use pesticide-resistant HALS, such as NOR HALS. Unfortunately, although these specific HALS are more resilient than general HALS, they do not fully solve the problem, and premature deterioration of greenhouse films due to the effect of pesticides on UV stabilizers is still observed.

[0008] Patent documents 1 and 2 disclose multilayer films including a polyamide co-extruded layer. The polyamide layer can act as a barrier layer to prevent the penetration of pesticides into the film in gaseous form. Unfortunately, this polyamide co-extruded layer has low elasticity and poor tear propagation strength, significantly reducing the mechanical strength of the film. In addition, the polyamide layer is highly susceptible to photodegradation, shortening the lifespan of the film. The polyamide layer also absorbs moisture (up to 9% of its mass), which often contains chemical residues, and this then diffuses throughout the entire mass of the film, destroying the stabilizers and / or the polymer itself. When the polyamide layer absorbs moisture, its permeability to gases also increases to a level where it can no longer prevent the penetration of pesticides into the film.

[0009] In the case of silage film, it is beneficial for the film to have low oxygen permeability to improve the anaerobic fermentation process, thus reducing mold loss and achieving better silage quality.

[0010] Multilayer silage films have been proposed, such as those described in Patent Document 3, that reduce oxygen permeability by using a co-extruded layer of polyamide (PA) or ethylene vinyl alcohol (EVOH) in the middle of the film. The drawback of these films is that their mechanical properties are inferior to those of polymer films that do not have a co-extruded layer of EVOH and / or PA. Impact resistance (dart test), which is important for this application, is particularly affected. In addition, the use of a co-extruded layer of EVOH or PA makes these films more difficult to recycle. Furthermore, the production of such films requires the use of a manufacturing machine capable of forming at least five layers of film, and the production process is very demanding and has a high scrap level.

[0011] Considering the above, there is an unmet need for improved films for covering agricultural structures that maintain excellent mechanical properties and recyclability while exhibiting low susceptibility to photodegradation in the presence of pesticides and good oxygen barrier properties. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] WO2009 / 060480 [Patent Document 2] EP1857272 [Patent Document 3] US6610377 [Overview of the project]

[0013] According to a first aspect of the present invention, a film for covering an agricultural structure is provided, the film being: (a) A polymer film having one or more layers, wherein at least one of the layers contains one or more UV stabilizers; and (b) A coating on at least one outer surface of a polymer film, wherein the film has a coating capacity of 500 ml / m² at 23°C and 0% relative humidity, as measured according to EN ISO 15105-2. 2 A coating comprising at least one layer containing a polymer to have an oxygen permeability of less than / bar / day; Includes.

[0014] The polymer coating on the surface of the polymer film provides the film with low oxygen permeability and therefore acts as an external gas barrier. As a result, the coating also acts as a barrier against gaseous pesticides or their derivatives, thereby preventing the deactivation of UV stabilizers in the film layer. Therefore, the film of the present invention has improved lifespan in the presence of pesticides because the polymer material of the film is less susceptible to photodegradation.

[0015] The low oxygen permeability of the film of the present invention is particularly advantageous for silage films because it promotes anaerobic fermentation, thereby reducing mold losses and achieving better silage quality.

[0016] As used herein, the term “coating” refers to one or more layers on the outer surface of a polymer film, each layer formed by depositing a solution. At least one layer of a polymer-containing coating is formed by depositing a polymer-containing solution. Thus, the coating forms the outer surface of the film and is not a layer within the polymer film. The coating according to the present invention is structurally different from the layers of film produced by co-extrusion. Because the coating is formed from a solution, the polymer is in the form of dispersed polymer chains, which deposit to form the coating. In contrast, a co-extruded layer is a continuous layer of plastics that have been molten together. Thus, the coating according to the present invention can be distinguished from a co-extruded layer of film by appropriate techniques. For example, the presence of a co-extruded layer in a film can be detected using infrared (IR) spectroscopy. Scanning electron microscopy (SEM) can be used to examine the surface of a film and identify the presence of a coating according to the present invention. Energy-dispersive X-ray spectroscopy (EDS) can be used to determine the elemental composition of the coating and thus identify the materials present in the coating.

[0017] Surprisingly, it has been found that using a barrier coating improves the mechanical properties compared to films containing a co-extruded barrier layer. Co-extruded barrier layers (e.g., those made from EVOH or polyamide) are rigid, and their presence reduces the elasticity and impact strength of the film. The barrier coating of the present invention does not suffer from these drawbacks.

[0018] In summary, by using a barrier coating on the surface of a polymer film, the film is provided with low oxygen permeability and reduced permeability to pesticides while maintaining excellent mechanical properties. Furthermore, the film of the present invention maintains excellent recyclability.

[0019] Furthermore, the inventors have found that the coating can enhance the hydrophilicity of the polymer film surface. This provides the film with highly desirable anti-drip properties for greenhouse covers (i.e., the film suppresses droplet formation on its surface).

[0020] According to another aspect of the present invention, the use of a coating on at least one outer surface of a polymer film is provided to reduce the susceptibility of the polymer film to photodegradation in the presence of a pesticide, wherein the coating comprises at least one layer containing a polymer, and the polymer film comprises one or more layers, at least one of which contains one or more UV stabilizers.

[0021] According to another aspect of the present invention, the use of a coating on at least one outer surface of a polymer film is provided to reduce the permeability of the polymer film to gas and / or water vapor, wherein the coating comprises at least one layer comprising a polymer, and the polymer film comprises one or more layers, at least one of which comprises one or more UV stabilizers.

[0022] According to another aspect of the present invention, an agricultural structure is provided, characterized in that at least a portion of the agricultural structure is covered with the film of the present invention.

[0023] According to another aspect of the present invention, a method for covering an agricultural structure is provided, which includes the step of covering at least a portion of the agricultural structure with a film according to the present invention.

[0024] According to another aspect of the present invention, a method is provided for producing a film for covering agricultural structures, the method comprising: (i) providing a polymer film comprising one or more layers, wherein at least one of the layers comprises one or more UV stabilizers; and (ii) depositing a coating on at least one outer surface of the polymer film, wherein the coating has a film thickness of 500 ml / m² at 23°C and 0% relative humidity, as measured according to EN ISO 15105-2. 2The step includes comprising at least one layer containing a polymer so as to have an oxygen permeability of less than / bar / day;

[0025] According to another aspect of the present invention, a film according to the present invention is provided that can be obtained by a method for producing the film according to the present invention. [Modes for carrying out the invention]

[0026] Polymer film The film of the present invention includes a polymer film having one or more layers.

[0027] The layers of the film can be made from any suitable polymer material known to those skilled in the art. Each of the layers of the polymer film may independently contain one or more polymers independently selected from the group including polyester, polyolefin, polyamide, and polyurethane. For example, each of the layers of the polymer film may independently contain one or more polymers independently selected from the group including low-density polyethylene (LDPE), low-density linear polyethylene (LLDPE), metallocene low-density linear polyethylene (MLLDPE), ethylene vinyl acetate copolymer (EVA), ethylene butyl acrylate copolymer (EBA), high-density polyethylene (HDPE), polypropylene (PP), thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide (PA), ethylene vinyl alcohol copolymer (EVOH), and combinations thereof.

[0028] At least one layer of the polymer film contains one or more UV stabilizers to provide the film with protection from UV radiation, i.e., to prevent photodegradation of the polymer material in the film, thereby extending the service life of the film. The UV stabilizers may be present in two or more layers of the polymer film or in all layers of the polymer film to provide a desired level of UV protection.

[0029] As used herein, "UV stabilizer" includes both a "UV absorber" that absorbs ultraviolet radiation and thereby prevents its absorption by the polymer of a polymer film, and a hindered amine light stabilizer that prevents chemical reactions that lead to photodegradation of the polymer.

[0030] Any suitable UV stabilizer can be used in the polymer film. One or more UV stabilizers may be independently selected from the group including hindered amine light stabilizers (HALS), UV absorbers, and nickel organic complexes (Ni quenchers).

[0031] In a preferred embodiment of the present invention, at least one layer of the polymer film contains a hindered amine light stabilizer (HALS).

[0032] Examples of HALS suitable for use in the present invention include: 1,3,5-triazine-2,4,6-triamine, N2,N2''-1,2-ethanediylbis[N2-[3-[[4,6-bis[butyl(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-triazine-2-yl]amino]propyl]-N', N''-dibutyl-N', N''-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-butanediic acid, 1,4-dimethyl ester, 4-hydroxy-2, These are polymers containing 2,6,6-tetramethyl-1-piperidineethanol; poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol-alt-1,4-butanediic acid); and poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]-1,6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino]]);

[0033] One or more UV stabilizers can be present in the film layer in any suitable amount based on the total weight of the layer, for example, 0.1 wt% to 20 wt%, preferably 0.1 wt% to 10 wt%, most preferably 0.1 wt% to 5 wt%, etc.

[0034] Each layer of the film may independently contain one or more additional components. For example, each or more layers of a polymer film may independently contain an IR absorber, an anti-fogging agent, an anti-drip agent, an anti-dust agent, an anti-algal agent, an adhesive agent, and / or a pigment.

[0035] As used herein, the term "IR absorber" refers to a substance that absorbs infrared radiation (IR).

[0036] As used herein, "water-repellent agent" refers to a substance that prevents water droplets from condensing, and "anti-fogging agent" refers to a substance that prevents the surface of a film from fogging up.

[0037] As used herein, "dustproof material" refers to a substance that repels dust from the surface of a film.

[0038] As used herein, "anti-algal material" refers to a substance that inhibits the growth of algae on a film.

[0039] As used herein, “adhesive material” refers to a substance that enhances the bonding of a coating on a film.

[0040] Suitable pigments that can be used in layers of polymer films include TiO2 and carbon black. Silage films typically have different colors on each side, for example, one side being black and the other white. It may be advantageous to have one side a lighter color (such as white) to reflect light and avoid overheating.

[0041] It is beneficial for greenhouse films to have high luminous transmittance to provide optimal light conditions inside the greenhouse for the cultivation of crops and plants. For example, the film of the present invention may have a luminous transmittance of at least 30%, preferably at least 50%, more preferably at least 75%, and most preferably at least 85%.

[0042] Furthermore, while it is sometimes preferable for greenhouse films to have low haze characteristics, this depends on the geographical location, as higher levels of haze may be desirable in certain regions of the world. Depending on the specific application, the films of the present invention may have haze levels ranging from 10% to 90%.

[0043] Haze and luminous transmittance can be measured according to the ASTM-D1003-92 standard test method for haze and luminous transmittance of transparent plastics. This test method encompasses the evaluation of specific light transmittance and wide-angle light scattering properties of planar surfaces of materials such as inherently transparent plastics. Procedures for measuring luminous transmittance and haze are provided. Materials with a haze value exceeding 30% are considered diffusive. In this test method, "haze" is defined as a cloudy or turbid appearance of an otherwise transparent sample caused by the scattering of light from within or on its surface. This is measured as the percentage of total transmitted light that deviates by an average of 0.044 rad (2.5°) or more from the incident beam through forward scattering as it passes through the sample. Luminous transmittance is the ratio of the light flux transmitted by an object to the light flux incident on it.

[0044] The film haze may be measured using a haze meter. Luminous transmittance can be obtained by placing a transparent sample away from the entrance of the integrating sphere.

[0045] The polymer film may have any suitable number of layers, such as 1 to 100 layers, preferably 3 to 11 layers. The film for covering agricultural structures may have any suitable total thickness and width, such as 25 μm to 500 μm and 1 m to 50 m or 1 to 60 m.

[0046] Polymer films can be manufactured by any suitable process known to those skilled in the art. Preferably, polymer films can be obtained by extrusion or co-extrusion, more preferably by extrusion or co-extrusion of blown film or cast film.

[0047] coating The film of the present invention is provided with a coating on at least one outer surface or side surface of a polymer film. This coating comprises at least one layer containing a polymer.

[0048] The coating acts as an external barrier on the polymer film, suppressing the permeation of gases such as oxygen and water vapor through the film. The coating has a viscosity of 500 ml / m², as measured according to EN ISO 15105-2 at 23°C and 0% relative humidity. 2 Less than / bar / day, preferably 200 ml / m³ 2 Less than / bar / day, more preferably 100 ml / m³ 2 The film provides oxygen permeability of less than / bar / day.

[0049] The coating is primarily responsible for the low oxygen permeability of the film. Preferably, an uncoated polymer film has an oxygen permeability of 500 ml / m² when measured according to EN ISO 15105-2 at 23°C and 0% relative humidity. 2 More than / bar / day, more preferably 1000ml / m³ 2 It has an oxygen permeability exceeding / bar / day.

[0050] The coating acts as a gas barrier, and therefore as a barrier against gaseous pesticides, preventing them from penetrating the polymer film layer and inactivating the UV stabilizers within it. By preventing the inactivation of UV stabilizers, the polymer material of the film is protected from photodegradation, extending the film's lifespan.

[0051] As will be understood by those skilled in the art, the term “pesticide” refers to chemical substances used in agriculture, such as pesticides, insecticides, fumigants, and fertilizers. As used herein, “pesticide” also includes sulfur and by-products produced by the decomposition of pesticides (e.g., under the influence of heat and UV radiation), such as compounds containing sulfur and chlorine.

[0052] When the film of the present invention is used to cover silage, low oxygen permeability promotes the anaerobic fermentation of silage. This results in less mold damage and better silage quality.

[0053] By utilizing an external barrier coating containing a polymer, the mechanical properties of the film are not impaired as compared to prior art films, for example, those containing a coextruded barrier layer. Coextruded barrier layers (such as those made of EVOH or polyamide, etc.) are rigid and have an adverse effect on the mechanical properties of the film. In prior art films, when a barrier material such as PA or EVOH is incorporated as a coextruded layer in the mass of the film, the flexibility of the coextruded barrier material is lower than that of other layers of the film (such as polyethylene, etc.), so the mechanical properties of the film are impaired. As such, the film of the present invention has improved mechanical properties, particularly impact resistance, which is particularly beneficial for silage films.

[0054] Also, the coating can provide the film with excellent abrasion resistance. Further, the coating can also enhance the hydrophilicity of the surface of the film. This provides the film with anti-droplet properties (i.e., suppresses droplet formation on the surface of the film). Since water droplets reduce light transmission by 15 - 30% and increase the incidence of certain diseases, this is particularly desirable for greenhouse films to prevent moisture condensation on the inner surface of the film, which can adversely affect the quality and growth of plants.

[0055] Also, this coating can provide the film with low permeability to water vapor, acting as a barrier to pesticides dissolved in water vapor. For example, the film may have a water permeability of less than 100 g / m 2 / day, preferably less than 50 g / m 2 / day, and most preferably less than 10 g / m 2 / day when measured according to standard ASTM E 96 at 38°C and 90% relative humidity.

[0056] The coatings described herein may be provided on one or both outer surfaces of a polymer film. The coatings on each outer surface of the polymer film may be the same or different. Accordingly, each coating may be determined independently as described herein.

[0057] Furthermore, the coating may consist of two or more layers, as long as at least one layer contains a polymer. Each layer of the coating may be the same or different. Alternatively, the coating may consist of only a single layer containing a polymer.

[0058] The coating covers substantially all of each outer surface of the polymer film to which the coating is provided. "Substantially all" means that at least 90%, preferably at least 95%, more preferably at least 98%, and most preferably at least 99% of the outer surface is covered by the coating.

[0059] Any suitable polymer can be used in the coating to provide the film with low oxygen permeability. In a preferred embodiment of the present invention, the polymer in the coating is a vinylidene chloride homopolymer or copolymer, or a vinyl alcohol homopolymer or copolymer.

[0060] When used in this specification, vinylidene chloride has the following structure:

[0061] [ka] It has.

[0062] As used herein, the term “homopolymer” refers to a polymer formed from the polymerization of essentially a single type of monomer or monomer species. Accordingly, the term “vinylidene chloride homopolymer” refers to a polymer formed from the polymerization of essentially only vinylidene chloride monomer. As such, a vinylidene chloride homopolymer contains at least 99 wt% vinylidene chloride monomer, based on the total weight of the homopolymer.

[0063] In this specification, references to the amount of vinylidene chloride monomer in a polymer refer to units derived from the polymerization of vinylidene chloride monomer, not to the monomer itself.

[0064] Vinylidene chloride homopolymer consists of the following repeating units:

[0065] [ka] It has such that, where "n" is the number of vinylidene chloride monomer units in the homopolymer.

[0066] As used herein, the term “copolymer” refers to a polymer formed from the polymerization of two or more types of monomers. Accordingly, the term “vinylidene chloride copolymer” refers to a polymer formed from the polymerization of vinylidene chloride monomer and one or more other monomers.

[0067] The vinylidene chloride copolymer may contain any suitable amount of vinylidene chloride monomer, as long as it contains at least one unit derived from another monomer.

[0068] To provide optimal barrier properties, it may be beneficial for the vinylidene chloride copolymer to contain at least 20 wt%, preferably at least 40 wt%, more preferably at least 50 wt%, more preferably at least 60 wt%, more preferably at least 70 wt%, and most preferably at least 80 wt%, based on the total weight of the copolymer, vinylidene chloride monomer.

[0069] Copolymerizing vinylidene chloride with one or more other monomers may be advantageous compared to using a homopolymer of vinylidene chloride. For example, the copolymer may have improved thermal stability. Therefore, in a preferred feature of the present invention, the coating comprises a vinylidene chloride copolymer. Preferably, the vinylidene chloride copolymer contains less than 95 wt%, preferably less than 90 wt%, of vinylidene chloride monomer, based on the total weight of the copolymer.

[0070] The vinylidene chloride copolymer may contain, based on the total weight of the copolymer, 20 wt% to 95 wt%, preferably 40 wt% to 95 wt%, more preferably 50 wt% to 95 wt%, more preferably 60 wt% to 95 wt%, more preferably 70 wt% to 95 wt%, and most preferably 80 wt% to 95 wt% of vinylidene chloride monomer.

[0071] Alternatively, the vinylidene chloride copolymer may contain 20 wt% to 90 wt%, preferably 40 wt% to 90 wt%, more preferably 50 wt% to 90 wt%, more preferably 60 wt% to 90 wt%, more preferably 70 wt% to 90 wt%, and most preferably 80 wt% to 90 wt%, of vinylidene chloride monomer, based on the total weight of the copolymer.

[0072] In one preferred embodiment of the present invention, the vinylidene chloride copolymer comprises at least 50 wt%, preferably 50 wt% to 95 wt%, and more preferably 50 wt% to 90 wt%, of vinylidene chloride monomer, based on the total weight of the copolymer.

[0073] When used in this specification, vinyl alcohol has the following structure:

[0074] [ka] It has.

[0075] As used herein, the term "vinyl alcohol homopolymer" refers to a polymer essentially formed from the polymerization of vinyl alcohol monomers. As such, a vinyl alcohol homopolymer contains at least 99 wt% vinyl alcohol monomer, based on the total weight of the homopolymer.

[0076] In this specification, references to the amount of vinyl alcohol monomer in a polymer refer to units derived from the polymerization of vinyl alcohol monomer, not the monomer itself. As will be correctly understood by those skilled in the art, polymers cannot actually be produced by polymerizing vinyl alcohol monomer. Typically, polyvinyl alcohol is produced by polymerizing vinyl acetate monomer to form polyvinyl acetate, which is then hydrolyzed. Alternatively, acetaldehyde (a tautomer of vinyl alcohol) monomer can be used.

[0077] Vinyl alcohol homopolymers consist of the following repeating units:

[0078] [ka] It has such that, where "n" is the number of vinyl alcohol monomer units in the homopolymer.

[0079] The term "vinyl alcohol copolymer" refers to a polymer formed from the polymerization of a vinyl alcohol monomer and one or more other monomers.

[0080] The vinyl alcohol copolymer may contain any suitable amount of vinyl alcohol monomer, as long as it contains at least one unit derived from another monomer.

[0081] When hydrolyzing polyvinyl acetate to produce polyvinyl alcohol, only partial hydrolysis is necessary. Therefore, vinyl alcohol copolymers may contain vinyl acetate monomers. Vinyl acetate has the following structure:

[0082] [ka] It has.

[0083] In other words, the vinyl alcohol copolymer may be a copolymer of vinyl alcohol and one or more further monomers, optionally including vinyl acetate as one or more further monomers.

[0084] To provide optimal barrier properties, it may be beneficial for the total amount of vinyl alcohol and vinyl acetate monomers in the vinyl alcohol copolymer to be at least 20 wt%, preferably at least 40 wt%, more preferably at least 50 wt%, more preferably at least 60 wt%, more preferably at least 70 wt%, and most preferably at least 80 wt%, based on the total weight of the copolymer.

[0085] Furthermore, the number of vinyl alcohol monomers in the copolymer is preferably at least 80%, preferably at least 95%, and most preferably at least 97%, of the total number of vinyl alcohol and vinyl acetate monomers. This optimizes the barrier properties of the copolymer and enhances its stability against humidity.

[0086] Naturally, vinyl acetate may not be present in the copolymer. In that case, the number of vinyl alcohol monomers is 100% of the total number of vinyl alcohol and vinyl acetate monomers, and the total amount of vinyl acetate and vinyl alcohol monomers corresponds to the amount of vinyl alcohol monomer in the copolymer.

[0087] Copolymerizing vinyl alcohol (and optionally vinyl acetate) with one or more other monomers may be advantageous compared to using vinyl alcohol and vinyl acetate alone. For example, it can improve the polymer's stability to humidity. Therefore, the total amount of vinyl alcohol and vinyl acetate monomers in a vinyl alcohol copolymer is preferably less than 95 wt%, and more preferably less than 90 wt%, based on the total weight of the copolymer.

[0088] The total amount of vinyl alcohol and vinyl acetate monomers in the vinyl alcohol copolymer may be 20 wt% to 95 wt%, preferably 40 wt% to 95 wt%, more preferably 50 wt% to 95 wt%, more preferably 60 wt% to 95 wt%, more preferably 70 wt% to 95 wt%, and most preferably 80 wt% to 95 wt%, based on the total weight of the copolymer.

[0089] Alternatively, the total amount of vinyl alcohol and vinyl acetate monomers in the vinyl alcohol copolymer may be 20 wt% to 90 wt%, preferably 40 wt% to 90 wt%, more preferably 50 wt% to 90 wt%, more preferably 60 wt% to 90 wt%, more preferably 70 wt% to 90 wt%, and most preferably 80 wt% to 90 wt%, based on the total weight of the copolymer.

[0090] In one preferred embodiment of the present invention, the total amount of vinyl alcohol and vinyl acetate monomers in the vinyl alcohol copolymer is at least 50 wt%, preferably 50 wt% to 95 wt%, and more preferably 50 wt% to 90 wt%, based on the total weight of the copolymer.

[0091] Vinyl alcohol homopolymers or copolymers may be modified. For example, one or more vinyl alcohol monomers may be modified by carboxylation, etherification, acetalization, carbamateization, amination, sulfation, or esterification. In this case, the hydroxyl group can be replaced with another functional group such as a carboxyl, ethylene oxide, acetyl, acetoacetyl, sulfonic acid, amino, or ammonium salt group.

[0092] One or more side chains can also be bonded to the vinyl alcohol monomer in the homopolymer or copolymer. Each side chain may be independently selected from polyethylene glycol, polyacrylic acid, polylactic acid, and amylose.

[0093] To improve its moisture resistance, the vinyl alcohol homopolymer or copolymer can be crosslinked. The vinyl alcohol homopolymer or copolymer can be crosslinked by heat, UV (ultraviolet radiation), and / or a crosslinking agent.

[0094] Any suitable crosslinking agent may be used. For example, the crosslinking agent may be selected from the group comprising alcohols, linear polyols, branched polyols, aldehydes, amines, polyamines, hydrazides, polyhydrazides, metal salts, acids, and organic acids. Preferably, the crosslinking agent is selected from the group comprising ethylene glycol, formaldehyde, acetaldehyde, glyoxal, malondialdehyde, succinidaldehyde, glutaraldehyde, metaxylenediamine, 1,3-bis(aminomethyl)cyclohexane, adipic acid dihydrazide, dodecanedihydrazide, polyol carbonyl adducts, sodium borate, zirconium ammonium carbonate, sodium glyoxylate, malonic acid, succinic acid, adipic acid, boric acid, and sulfosuccinic acid.

[0095] In the copolymers described herein, any suitable monomer, such as an ethylenically unsaturated monomer, can be copolymerized with vinylidene chloride, vinyl alcohol, and / or vinyl acetate. As used herein, "ethylenically unsaturated monomer" refers to a monomer containing a carbon-carbon double bond.

[0096] In one preferred feature of the present invention, the vinylidene chloride copolymer may be a copolymer of vinylidene chloride and one or more further monomers, and / or the vinyl alcohol copolymer may be a copolymer of vinyl alcohol, one or more further monomers, and optionally vinyl acetate. The one or more further monomers may be independently selected from the group consisting of alkenes, acrylic acids, vinyl halides, vinyl amides, styrenes, vinyl alcohols, vinyl esters, vinyl ethers, vinyl ketones, maleic acid or maleic acid esters, fumaric acid or fumaric acid esters, itaconic acid or itaconic acid esters, crotonic acid or crotonic acid esters.

[0097] For example, vinylidene chloride copolymer may be a copolymer of vinylidene chloride and one or more monomers of formula (I). Vinyl alcohol copolymer may be a copolymer of vinyl alcohol, one or more monomers of formula (I), and optionally vinyl acetate:

[0098] [ka] In the formula, each R 1 H, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C1-C 10 Alkoxy, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 Aryl, C1-C9 heteroaryl, nitrile, -OH, halo, -C(O)R 4 , -C(O)OR 4 -OC(O)R 4 -C(O)NHR 4 , and -NHC(O)R 4Selected independently from the group containing; Each R 2 H, halo, C1-C3 alkyl, -C(O)OR 5 , and -CH2C(O)OR 5 Selected independently from the group containing; Each R 3 H, -C(O)OR 5 , and independently selected from the group including C1-C3 alkyl groups; Each R 4 H, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 Independently selected from the group including aryls and C1-C9 heteroaryls; Each R 5 C1-C 10 Selected independently of alkyl; Each C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C1-C 10 Alkoxy, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 The aryl and C1-C9 heteroaryl groups are optionally and independently substituted with one or more substituents independently selected from -OH, oxo, -SO2H, -NO2, and halo.

[0099] Examples of monomers that can copolymerize with vinylidene chloride include: ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, acrylic acid, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methoxyethyl acrylate, chloroethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-pentyl methacrylate, methacrylate Examples include n-hexyl methacrylate, cyclohexyl methacrylate, n-heptyl methacrylate, n-octyl methacrylate, 2-ethylhexyl acrylate, phenyl methacrylate, methoxyethyl methacrylate, chloroethyl methacrylate, acrylonitrile, methacrylonitrile, methyl vinyl ketone, phenyl vinyl ketone, methyl vinyl ether, ethyl vinyl ether, divinyl ether, vinyl chloride, vinyl bromide, vinyl alcohol, vinyl acetate, vinyl propionate, vinyl chloroacetate, vinylnaphthalene, styrene, maleic acid, maleic anhydride, fumaric acid, dimethyl maleate, diethyl maleate, dimethyl fumarate, diethyl fumarate, crotonic acid, methyl crotonic acid, ethyl crotonic acid, n-propyl crotonic acid, n-butyl crotonic acid, itaconic acid, dimethyl itaconic acid, diethyl itaconic acid, dibutyl itaconic acid, acrylamide, methacrylamide, and vinylpyridine.

[0100] Preferably, the vinylidene chloride copolymer is a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being independently selected from the group consisting of ethene, propene, butene, acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, acrylonitrile, methacrylonitrile, vinyl chloride, styrene, methyl vinyl ketone, vinyl alcohol, vinyl acetate, and itaconic acid.

[0101] Examples of monomers that can copolymerize with vinyl alcohol and optionally with vinyl acetate include: ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, acrylic acid, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methoxyethyl acrylate, chloroethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n- Examples include pentyl, n-hexyl methacrylate, cyclohexyl methacrylate, n-heptyl methacrylate, n-octyl methacrylate, 2-ethylhexyl acrylate, phenyl methacrylate, methoxyethyl methacrylate, chloroethyl methacrylate, acrylonitrile, methacrylonitrile, methyl vinyl ketone, phenyl vinyl ketone, methyl vinyl ether, ethyl vinyl ether, divinyl ether, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl propionate, vinyl chloroacetate, vinylnaphthalene, styrene, maleic acid, maleic anhydride, fumaric acid, dimethyl maleate, diethyl maleate, dimethyl fumarate, diethyl fumarate, crotonic acid, methyl crotonic acid, ethyl crotonic acid, n-propyl crotonic acid, n-butyl crotonic acid, itaconic acid, dimethyl itaconic acid, diethyl itaconic acid, dibutyl itaconic acid, acrylamide, methacrylamide, and vinylpyridine.

[0102] Preferably, the vinyl alcohol copolymer is a copolymer of vinyl alcohol, optionally vinyl acetate, and one or more further monomers, the one or more further monomers being independently selected from the group comprising ethene, propene, butene, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, styrene, methyl vinyl ketone, and itaconic acid.

[0103] In preferred embodiments, the vinylidene chloride copolymer may be a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being selected from vinyl chloride, methyl acrylate, methyl methacrylate, hydroxyethyl acrylate, acrylonitrile, methacrylonitrile, vinyl alcohol, and vinyl acetate.

[0104] In another preferred embodiment, the vinylidene chloride copolymer may be a copolymer of vinylidene chloride, methyl acrylate, acrylonitrile, and hydroxyethyl acrylate.

[0105] In another preferred embodiment, the vinylidene chloride copolymer may be a copolymer of vinylidene chloride, methyl acrylate, and vinyl chloride.

[0106] In another preferred embodiment, the vinylidene chloride copolymer may be a copolymer of vinylidene chloride and vinyl chloride.

[0107] In another preferred embodiment, the vinylidene chloride copolymer may be a copolymer of vinylidene chloride and methyl acrylate.

[0108] In another preferred embodiment, the vinyl alcohol copolymer may be a copolymer of vinyl alcohol, optionally vinyl acetate, and one or more monomers, the one or more monomers being selected from ethene, propene, butene, methyl acrylate, methyl methacrylate, butyl acrylate, hydroxyethyl acrylate, vinyl chloride, and vinylidene chloride.

[0109] The total thickness of the coating on each outer surface of the polymer film may be independently 0.1 μm to 20 μm, preferably 0.1 μm to 10 μm.

[0110] At least one layer of the polymer-containing coating may have a thickness of 0.1 μm to 5 μm, preferably 0.3 μm to 1.5 μm. Alternatively, at least one layer of the polymer-containing coating may have a thickness of 0.1 μm to 5 μm, more preferably 0.2 μm to 2.0 μm, and most preferably 0.2 μm to 1.0 μm.

[0111] The coating may contain any suitable amount of polymer to provide low oxygen permeability to the film. When a vinyl alcohol homopolymer or copolymer is used as the polymer, at least one layer of the polymer-containing coating may contain at least 1 wt%, more preferably at least 3 wt%, and more preferably at least 6 wt%, of the polymer, based on the total dry weight of the at least one layer of the polymer-containing coating. When a vinylidene chloride homopolymer or copolymer is used as the polymer, at least one layer of the polymer-containing coating preferably contains at least 30 wt%, more preferably at least 50 wt%, and most preferably at least 70 wt%, of the polymer, based on the total dry weight of the at least one layer of the polymer-containing coating. "Dry weight" means the weight of the coating after the solvent has been removed.

[0112] By depositing a polymer solution, it is possible to form a very thin coating on the surface of a polymer film, thereby avoiding damage to the flexibility and mechanical properties of the polymer film. Co-extruded barrier layers are typically much thicker, which is detrimental to the flexibility and mechanical properties of the film. Furthermore, the weight of a thin barrier coating is negligible compared to the total weight of the film. Therefore, the small amount of coating material present does not significantly affect the recyclability of the film. Films with thicker co-extruded layers (such as EVOH and polyamide) are more difficult to recycle, and the recycled material produced from their scrap after the film's service life is of lower quality and has less commercial value than recycled polyethylene resin without such co-extruded layers (e.g., EVOH and polyamide).

[0113] In addition to the polymer, each coating may independently contain one or more further components.

[0114] For example, each coating is made of SiO 2、 Al2O 3、 TiO 2、 AlCl 3、 MgO, ZnO, CuO, Fe2O 3、 It may independently contain one or more inorganic particles independently selected from the group including clay and combinations thereof.

[0115] Each coating may independently contain one or more organic molecules independently selected from the group including acrylic resins, epoxy resins, polyurethanes, polyimines, polysiloxanes, surfactants, binders, and combinations thereof.

[0116] In a preferred embodiment of the present invention, the vinylidene chloride copolymer comprises at least 50 wt% vinylidene chloride monomer based on the total weight of the copolymer, and further, the copolymer is a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being independently selected from the group consisting of alkenes, acrylic acids, vinyl halides, vinyl amides, styrenes, vinyl esters, vinyl ethers, vinyl ketones, maleic acid or maleic acid esters, fumaric acid or fumaric acid esters, itaconic acid or itaconic acid esters, crotonic acid or crotonic acid esters.

[0117] In another preferred embodiment of the present invention, the vinylidene chloride copolymer comprises at least 50 wt% vinylidene chloride monomer based on the total weight of the copolymer, and further, the copolymer is a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being independently selected from the group comprising acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, vinyl chloride, styrene, methyl vinyl ketone, vinyl acetate, and itaconic acid.

[0118] In another preferred embodiment of the present invention, the vinylidene chloride copolymer comprises at least 50 wt% vinylidene chloride monomer based on the total weight of the copolymer, and further, the copolymer is a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being independently selected from the group comprising vinyl chloride, methyl acrylate, hydroxyethyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile, and vinyl acetate.

[0119] In another preferred embodiment of the present invention, the coating comprises a vinylidene chloride copolymer comprising 50 wt% to 95 wt% vinylidene chloride monomer based on the total weight of the copolymer, further comprising a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being independently selected from the group comprising vinyl chloride, methyl acrylate, hydroxyethyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile, and vinyl acetate.

[0120] In another preferred embodiment of the present invention, one or more UV stabilizers comprise a hindered amine light stabilizer, and further comprises a vinylidene chloride copolymer comprising at least 50 wt% vinylidene chloride monomer based on the total weight of the copolymer.

[0121] In another preferred embodiment of the present invention, one or more UV stabilizers comprise a hindered amine light stabilizer, and further, the vinylidene chloride copolymer comprises at least 50 wt% vinylidene chloride monomer based on the total weight of the copolymer, and further, the copolymer is a copolymer of vinylidene chloride and one or more monomers, and one or more monomers are independently selected from the group comprising alkenes, acrylic acids, vinyl halides, vinyl amides, styrenes, vinyl esters, vinyl ethers, vinyl ketones, maleic acid or maleic acid esters, fumaric acid or fumaric acid esters, itaconic acid or itaconic acid esters, crotonic acid or crotonic acid esters.

[0122] In another preferred embodiment of the present invention, one or more UV stabilizers comprise a hindered amine light stabilizer, and further, the vinylidene chloride copolymer comprises at least 50 wt% vinylidene chloride monomer based on the total weight of the copolymer, and further, the copolymer is a copolymer of vinylidene chloride and one or more monomers, one or more monomers independently selected from the group comprising acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, vinyl chloride, styrene, methyl vinyl ketone, vinyl acetate, and itaconic acid.

[0123] In another preferred embodiment of the present invention, one or more UV stabilizers comprise a hindered amine light stabilizer, and further, the vinylidene chloride copolymer comprises at least 50 wt% vinylidene chloride monomer based on the total weight of the copolymer, and further, the copolymer is a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being independently selected from the group comprising vinyl chloride, methyl acrylate, hydroxyethyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile, and vinyl acetate.

[0124] In another preferred embodiment of the present invention, one or more UV stabilizers comprise a hindered amine light stabilizer, and further comprising a vinylidene chloride copolymer comprising 50 wt% to 95 wt% vinylidene chloride monomer based on the total weight of the copolymer, wherein the copolymer is a copolymer of vinylidene chloride and one or more monomers, and the one or more monomers are independently selected from the group comprising vinyl chloride, methyl acrylate, hydroxyethyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile, and vinyl acetate.

[0125] In another preferred embodiment of the present invention, the number of vinyl alcohol monomers in the vinyl alcohol copolymer is at least 97% of the total number of vinyl alcohol and vinyl acetate monomers in the copolymer, and the vinyl alcohol copolymer is crosslinked with a crosslinking agent independently selected from the group consisting of glyoxal, glutaraldehyde, metaxylenediamine, 1,3-bis(aminomethyl)cyclohexane, adipic acid dihydrazide, dodecane dihydrazide, zirconium ammonium carbonate, sodium glyoxylate, boric acid, and sulfosuccinic acid.

[0126] In another preferred embodiment of the present invention, the vinyl alcohol copolymer is a copolymer of one or more monomers selected from vinyl alcohol, ethene and butyl acrylate, and optionally vinyl acrylate, wherein the number of vinyl alcohol monomers in the vinyl alcohol copolymer is at least 97% of the total number of vinyl alcohol and vinyl acetate monomers in the copolymer, and the copolymer is crosslinked with one or more crosslinking agents independently selected from the group including glyoxal, glutaraldehyde, metaxylenediamine, 1,3-bis(aminomethyl)cyclohexane, adipic acid dihydrazide, dodecane dihydrazide, zirconium ammonium carbonate, sodium glyoxylate, boric acid, and sulfosuccinic acid.

[0127] In another preferred embodiment of the present invention, the vinyl alcohol copolymer is a copolymer of one or more monomers selected from vinyl alcohol, ethene and butyl acrylate, and optionally vinyl acrylate, wherein the number of vinyl alcohol monomers in the vinyl alcohol copolymer is at least 97% of the total number of vinyl alcohol and vinyl acetate monomers in the copolymer, and the copolymer is crosslinked with one or more crosslinking agents independently selected from the group including glyoxal, glutaraldehyde, metaxylenediamine, 1,3-bis(aminomethyl)cyclohexane, adipic acid dihydrazide, dodecane dihydrazide, zirconium ammonium carbonate, sodium glyoxylate, boric acid, and sulfosuccinic acid, and the coating is SiO 2、 Al2O 3、 TiO 2、 AlCl 3、 MgO, ZnO, CuO, Fe2O 3、 It further comprises one or more inorganic particles independently selected from the group including clay.

[0128] In another preferred embodiment of the present invention, the number of vinyl alcohol monomers in the vinyl alcohol copolymer is at least 97% of the total number of vinyl alcohol and vinyl acetate monomers in the copolymer, one or more vinyl alcohol monomers in the copolymer are modified by carboxylation, etherification, acetalization, carbamateization, amination, sulfation, or esterification, and the copolymer is crosslinked with one or more crosslinking agents independently selected from the group consisting of glyoxal, glutaraldehyde, metaxylenediamine, 1,3-bis(aminomethyl)cyclohexane, adipic acid dihydrazide, dodecane dihydrazide, zirconium ammonium carbonate, sodium glyoxylate, boric acid, and sulfosuccinic acid.

[0129] In another preferred embodiment of the present invention, the number of vinyl alcohol monomers in the vinyl alcohol copolymer is at least 97% of the total number of vinyl alcohol and vinyl acetate monomers in the copolymer, one or more vinyl alcohol monomers in the copolymer are modified by carboxylation, etherification, acetalization, carbamateization, amination, sulfation, or esterification, the copolymer is crosslinked with one or more crosslinking agents independently selected from the group including glyoxal, glutaraldehyde, metaxylenediamine, 1,3-bis(aminomethyl)cyclohexane, adipic acid dihydrazide, dodecane dihydrazide, zirconium ammonium carbonate, sodium glyoxylate, boric acid, and sulfosuccinic acid, and the coating is SiO 2、 Al2O 3、 TiO 2、 AlCl 3、 MgO, ZnO, CuO, Fe2O 3、 The further comprises one or more inorganic particles independently selected from the group including clay.

[0130] In another preferred embodiment of the present invention, the number of vinyl alcohol monomers in the vinyl alcohol copolymer is at least 97% of the total number of vinyl alcohol and vinyl acetate monomers in the copolymer, one or more vinyl alcohol monomers in the copolymer are modified by carboxylation, etherification, acetalization, carbamateization, amination, sulfation, or esterification, the copolymer is crosslinked with one or more crosslinking agents independently selected from the group including glyoxal, glutaraldehyde, metaxylenediamine, 1,3-bis(aminomethyl)cyclohexane, adipic acid dihydrazide, dodecane dihydrazide, zirconium ammonium carbonate, sodium glyoxylate, boric acid, and sulfosuccinic acid, and the coating further comprises one or more organic molecules independently selected from the group including acrylic resins, epoxy resins, polyurethanes, polyimines, polysiloxanes, surfactants, and binders.

[0131] agricultural structures The film of the present invention is suitable for covering agricultural structures. As used herein, the term “agricultural structure” refers to a structure designed for agricultural purposes, such as a greenhouse, silage pit, or silage bunker.

[0132] As such, the present invention also includes an agricultural structure characterized in that at least a portion thereof is covered with the film of the present invention. Furthermore, the present invention includes a method for covering an agricultural structure, which includes the step of covering at least a portion of the agricultural structure with the film of the present invention.

[0133] In one embodiment, the film can cover substantially the entirety of the agricultural structure.

[0134] For example, the film of the present invention can be used to cover a greenhouse. The film can cover a greenhouse such that the "internal" surface of the polymer film (i.e., the inside of the greenhouse) has the coating described herein. Thus, the coating protects the layer of the polymer film from pesticides used inside the greenhouse.

[0135] The film of the present invention can also be used to cover silage. The film can cover silage such that the “external” surface of the polymer film (i.e., the surface of the film not in contact with the silage) or the “internal surface” (i.e., the surface of the film in contact with the silage) has the coating described herein. This coating acts as an external barrier, inhibiting oxygen permeation through the film and contact with the silage.

[0136] Method for producing the film of the present invention The film of the present invention can be produced by any suitable method known to those skilled in the art.

[0137] The film of the present invention can be produced, firstly, by providing a polymer film comprising one or more layers, wherein at least one of the layers comprises one or more UV stabilizers as described herein. Thereafter, either online during the production of the film or offline as a separate step, a coating as described herein is deposited on at least one outer surface of the polymer film, the coating comprising at least one layer comprising a polymer.

[0138] The method may include the step of producing a polymer film by extrusion or co-extrusion of a blown film or cast film.

[0139] Prior to coating deposition, the outer surface of the polymer film may be treated with corona and / or plasma. This can improve the adhesion of the coating to the outer surface of the polymer film.

[0140] Each layer of the coating is deposited as a solution containing the components of that layer. The first layer of the coating is deposited on the surface of the polymer film. Once the first layer of the coating dries, the second layer (if any) is deposited on top of the first layer. This process is continued to produce a coating with any number of layers.

[0141] At least one layer of the polymer-containing coating is deposited as a polymer-containing solution. Any suitable solvent, such as water, can be used. When vinylidene chloride homopolymer or copolymer is used as the polymer, the solution may contain 5%ww to 90%ww, preferably 20%ww to 70%ww, and most preferably 50%ww to 60%ww of the polymer. When vinyl alcohol homopolymer or copolymer is used as the polymer, the solution may contain 1%ww to 20%ww, preferably 2%ww to 10%ww, and most preferably 3%ww to 6%ww of the polymer.

[0142] The coating can be deposited by any suitable coating technique known to those skilled in the art. Preferably, the coating is deposited by dipping, spraying, flexographic printing, plasma, laser, gravure printing, reverse roll, roll-to-roll, knife overall, rod coater, jet printing, or slot die coating techniques.

[0143] Once deposited, the polymer film can be annealed and rapidly cooled to stabilize the coating. [Examples]

[0144] A transparent greenhouse film with a thickness of 180 μm and a width of 12 m was produced on a 7-layer blow film line using an 1800 mm die at an output of 1300 kg / h and a speed of 11 m / min. The composition of the layers of this film is shown in Table 1 below. This film was corona-treated, and a coating was formed on one side by spraying a 50% aqueous solution of a copolymer of vinylidene chloride, methyl acrylate, acrylonitrile, and hydroxyethyl acrylate (Solvay's Diofan 050). The thickness of the coating was 0.8 μm.

[0145] [Table 1] LDPE = Low-density polyethylene; LLDPE = Low-density linear polyethylene; MLLDPE = Metallocene low-density linear polyethylene; EVA = Ethylene vinyl acetate copolymer with a 14% vinyl acetate content; UV = UV masterbatch with a combination of UV stabilizers (UV20H with 20% HALS Chimassorb944); IR = IR masterbatch with an infrared absorber. [Examples]

[0146] A black / white silage film with a thickness of 100 μm and a width of 12 m was produced on a 7-layer blow film line using an 1800 mm die at an output of 1300 kg / h and a speed of 19 m / min. The composition of the layers of this film is shown in Table 2 below. The film was corona-treated and then immersed in a tank containing a 58% ww aqueous solution of vinylidene chloride copolymer (Solvay's Diofan 063) to form a polymer coating on one side of the film. The thickness of the coating was 1 μm. Immediately after immersion, the film was passed through a dryer to evaporate the moisture, cooled, and rolled.

[0147] [Table 2] White = a white masterbatch containing 70% titanium dioxide in the PE carrier; Black = a black masterbatch containing 40% carbon black in the PE carrier. The remaining abbreviations in Table 2 are defined as previously defined for Table 1.

[0148] Comparative Example 1 A 7-layer film with a thickness of 180 μm is described in Table 3 below.

[0149] [Table 3] The abbreviations in Table 3 have been defined previously.

[0150] Comparative Example 2 A 7-layer, 100 μm silage film has a 2.5 μm EVOH layer in the middle. The layer composition of this film is shown in Table 4 below.

[0151] [Table 4] Green = Green masterbatch with green pigment in a PE carrier; Silver = Silver masterbatch with aluminum pigment in a PE carrier; EVOH44% = 44% moles of ethylene vinyl alcohol; TIE = Tie Layer resin. The remaining abbreviations in Table 4 are defined previously.

[0152] Oxygen permeability The oxygen permeability of the film compared to the examples and comparative examples was determined according to the standard EN ISO15105-2(23 o Measurements were taken according to (C, 0%RH). The results are shown in Table 5 below.

[0153] [Table 5] The film of Example 1, which has a coating containing vinylidene chloride copolymer on its surface, has significantly lower oxygen permeability than Comparative Example 1, which does not have such a coating. This demonstrates that a coating containing vinylidene chloride homopolymer or copolymer provides low oxygen permeability to the film.

[0154] Permeability to pesticides Two identical metal structures (dimensions of the metal structures: 1850cm x 1100cm x 1000cm) were covered using the films of Example 1 and Comparative Example 1. Sulfur burners, which sublimate sulfur using infrared lamps, were suspended from the center of the roof of each metal structure (and at a distance of 40cm from there). The sulfur burners were operated for 30 minutes a day for a total of 3 days. The sulfur burners acted as a sulfur source inside the metal structures, simulating pesticides that decompose under the influence of heat and UV radiation, producing active compounds such as sulfur.

[0155] Subsequently, film samples were taken from both films located on the upper parts of the two structures. The film samples were mechanically scraped to remove sulfur from their surfaces, and then the sulfur concentration was measured using a Mitsubishi Chemical sulfur analyzer.

[0156] The results of the sulfur analysis are shown in Table 6 below. As can be seen, the sulfur content of the sample derived from the film of Example 1 is significantly lower than that of the sample derived from the film of Comparative Example 1. This demonstrates that the oxygen barrier coating on the outer surface of the polymer film of Example 1 reduces the film's permeability to sulfur, thereby reducing the inactivation of the UV stabilizer in the polymer film. Therefore, the film of the present invention demonstrates reduced susceptibility to photodegradation in the presence of pesticides.

[0157] [Table 6] Dart drop impact resistance The dart drop impact resistance of the films in Example 2 and Comparative Example 2 was measured according to the standard EN ISO 77651 standard. The results are shown in Table 7 below.

[0158] [Table 7] The film of Comparative Example 2 contains a co-extruded EVOH barrier layer in the middle of the film. As described above, this was 14 cm at 0.2 bar. 3 / cm 2 This provides the film with oxygen permeability of 1 / day. However, this co-extruded barrier layer negatively affects the mechanical properties of the film. For example, the dart drop impact resistance of the film in Comparative Example 2 is only 500g.

[0159] In contrast, the film of Example 2 was 15 cm at 0.2 bar. 3 / cm 2 It has a similarly low oxygen permeability of 900g / day, but possesses significantly superior dart drop impact resistance of 900g. Therefore, the barrier coating of Example 2 provides the film with low oxygen permeability, but provides the film with improved mechanical properties compared to the co-extruded barrier layer of Comparative Example 2.

[0160] This demonstrates that the film of the present invention has low permeability to oxygen gas while maintaining excellent mechanical properties (and therefore has reduced susceptibility to photodegradation in the presence of pesticides, as previously demonstrated in Example 1).

[0161] Permeability to water vapor The permeability of the films of Example 1 and Comparative Example 1 to water vapor was measured according to standard ASTM E96 (T=38°C, Δ(RH)=90%). The results are shown in Table 8 below.

[0162] [Table 8] Comparative Example 3 Co-extruded films were prepared using the compositions specified in Table 9 below.

[0163] [Table 9] The mechanical properties of this film are described in detail in Table 10 below.

[0164] [Table 10] IRT=infrared transmittance; GLT=global light transmittance; Diff.T.=diffuse transmittance.

[0165] Table 10 shows that the presence of a co-extruded layer containing polyamide in a film reduces its mechanical properties. The film of the present invention, which has a barrier coating, is not plagued by these problems. For example, the film of Comparative Example 3 has a dart drop impact resistance of only 550g, while the film of Example 2 of the present invention has a significantly higher dart drop impact resistance of 900g.

[0166] Numbered Embodiments of the Invention Embodiment 1: A film for covering agricultural structures, (a) A polymer film having one or more layers, wherein at least one of the layers contains one or more UV stabilizers, (b) A coating comprising a vinylidene chloride homopolymer or copolymer on at least one outer surface of the polymer film, A film containing this material.

[0167] Embodiment 2: The film according to Embodiment 1, wherein the coating has a thickness of 0.1 μm to 5 μm, preferably 0.3 μm to 1.5 μm.

[0168] Embodiment 3: The coating is SiO 2、 Al2O 3、 TiO 2、 AlCl 3、 MgO, ZnO, CuO, Fe2O 3、 A film according to Embodiment 1 or 2, comprising one or more inorganic particles independently selected from the group including and combinations thereof, and / or one or more organic molecules independently selected from the group including acrylic resin, epoxy resin, polyurethane, surfactant, and combinations thereof.

[0169] Embodiment 4: The vinylidene chloride copolymer comprises, based on the total weight of the copolymer, at least 20 wt%, preferably at least 40 wt%, more preferably at least 50 wt%, more preferably at least 60 wt%, more preferably at least 70 wt%, most preferably at least 80 wt%, of vinylidene chloride monomer, and / or The vinylidene chloride copolymer is a film according to any one of Embodiments 1 to 3, comprising less than 95 wt%, preferably less than 90 wt%, of vinylidene chloride monomer based on the total weight of the copolymer.

[0170] Embodiment 5: The vinylidene chloride copolymer is a copolymer of vinylidene chloride and one or more monomers of formula (I),

[0171] [ka] In the formula, each R 1 H, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C1-C 10 Alkoxy, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 Aryl, C1-C9 heteroaryl, nitrile, -OH, halo, -C(O)R 4 , -C(O)OR 4 -OC(O)R 4 -C(O)NHR 4 , and -NHC(O)R 4 Independently selected from the group containing, Each R 2 H, halo, C1-C3 alkyl, -C(O)OR 5 , and -CH2C(O)OR 5 Independently selected from the group containing, Each R 3 H, -C(O)OR 5 , and independently selected from the group including C1-C3 alkyl, Each R 4 H, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 Independently selected from the group including aryls and C1-C9 heteroaryls, Each R 5 C1-C 10 Selected independently of alkyl, Each C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C1-C 10 Alkoxy, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 The film according to any one of Embodiments 1 to 4, wherein the aryl and C1-C9 heteroaryl are optionally and independently substituted with one or more substituents independently selected from -OH, oxo, -SO2H, -NO2, and halo.

[0172] Embodiment 6: The vinylidene chloride copolymer is a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being independently selected from the group comprising alkenes, acrylic acid, vinyl halide, vinylamide, styrene, vinyl ester, vinyl ether, vinyl ketone, maleic acid or maleic acid ester, fumaric acid or fumaric acid ester, itaconic acid or itaconic acid ester, crotonic acid or crotonic acid ester, preferably the vinylidene chloride copolymer is a copolymer of vinylidene chloride and one or more monomers, the one or more monomers being independently selected from the group comprising acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, vinyl chloride, styrene, methyl vinyl ketone, vinyl acetate, and itaconic acid, the film according to any one of Embodiments 1 to 5.

[0173] Embodiment 7: A film according to any one of Embodiments 1 to 6, wherein the film comprises a coating on both outer surfaces of the polymer film, and each coating is independently one of those described in any one of Embodiments 1 to 6.

[0174] Embodiment 8: One or more layers of the polymer film independently contain one or more polymers independently selected from the group including low-density polyethylene (LDPE), low-density linear polyethylene (LLDPE), ethylene vinyl acetate copolymer (EVA), ethylene butyl acrylate copolymer (EBA), high-density polyethylene (HDPE), polypropylene (PP), thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide (PA), ethylene vinyl alcohol copolymer (EVOH), and / or combinations thereof, and / or The film according to any one of Embodiments 1 to 7, wherein at least one of the layers of the polymer film further comprises an IR absorber, an anti-fogging agent, an anti-drip agent, an anti-dust material, an anti-algal material, and / or a pigment.

[0175] Embodiment 9: One or more UV stabilizers are independently selected from the group comprising hindered amine light stabilizers (HALS), UV absorbers, and nickel organic complexes, and / or The film according to any one of Embodiments 1 to 8, wherein one or more UV stabilizers are present in an amount of 0.1 wt% to 20 wt%, preferably 0.1 wt% to 10 wt%, and most preferably 0.1 wt% to 5 wt%, based on the total weight of the layer.

[0176] Embodiment 10: The polymer film has 1 to 100 layers, preferably 3 to 11 layers, and / or Polymer films can be obtained by co-extrusion, preferably by co-extrusion of blown film or cast film, and / or The film has a total thickness of 25 μm to 500 μm and a total width of 1 m to 50 m, and / or The film has a viscosity of 500 ml / m² when measured according to ASTM D3985 at 23°C and 0% relative humidity. 2 Less than / day, preferably 100 ml / m² 2 A film according to any one of Embodiments 1 to 9, having an oxygen permeability of less than 1 / day.

[0177] Embodiment 11: Use of a coating comprising a vinylidene chloride homopolymer or copolymer on at least one outer surface of a polymer film, wherein the polymer film comprises one or more layers, and at least one layer comprises one or more UV stabilizers, thereby reducing the sensitivity of the polymer film to photodegradation in the presence of pesticides and / or reducing the permeability of the polymer film to gases and / or water vapor.

[0178] Embodiment 12: An agricultural structure characterized in that at least a portion of it is covered with the film described in any of Embodiments 1 to 10.

[0179] Embodiment 13: A method for covering an agricultural structure, comprising the step of covering at least a portion of the agricultural structure with a film according to any one of Embodiments 1 to 10.

[0180] Embodiment 14: A method for producing a film for covering an agricultural structure, comprising: (i) providing a polymer film comprising one or more layers, wherein at least one of the one or more layers comprises one or more UV stabilizers; (ii) depositing a coating comprising a vinylidene chloride homopolymer or copolymer on at least one outer surface of the polymer film; A method comprising the above steps.

[0181] Embodiment 15: The coating is deposited via dipping, spraying, flexographic printing, plasma, laser, gravure printing, reverse roll, roll-to-roll, knife over all, rod coater, jet printing, or slot die, and / or the outer surface of the polymer film is treated with plasma prior to the deposition of the coating, and / or The method further comprises producing the polymer film via blow or cast coextrusion, the method for producing a film according to Embodiment 14.

[0182] Embodiment 16: A film for covering an agricultural structure, comprising: (a) a polymer film having one or more layers, wherein at least one of the layers comprises one or more UV stabilizers; (b) a coating on at least one outer surface of the polymer film, the coating comprising at least one layer containing a polymer such that the film has an oxygen permeability of less than 500 ml / m 2 / bar / day at 23 °C and 0% relative humidity when measured according to EN ISO 15105-2; A film comprising the above components.

[0183] Embodiment 17: The film according to Embodiment 16, having an oxygen permeability of less than 200 ml / m 2 / bar / day, preferably less than 100 ml / m 2 / bar / day.

[0184] Embodiment 18: When measured according to ASTM E 96, at 38 °C and 90% relative humidity, less than 100 g / m 2 / day, preferably less than 50 g / m 2 / day, most preferably less than 10 g / m 2 / day, and has a water vapor permeability of the film according to Embodiment 16 or 17.

[0185] Embodiment 19: At least one layer of the coating containing the polymer has a thickness of 0.1 μm to 5 μm, preferably 0.1 μm to 2.0 μm, and most preferably 0.2 μm to 1.0 μm, and the film according to any one of Embodiments 16 to 18.

[0186] Embodiment 20: The coating is SiO 2、 Al2O 3、 TiO 2、 AlCl 3、 MgO, ZnO, CuO, Fe2O 3、 clay, and one or more inorganic particles independently selected from the group consisting of combinations thereof, and / or one or more organic molecules independently selected from the group consisting of acrylic resins, epoxy resins, polyurethanes, polyimines, polysiloxanes, surfactants, binders, and combinations thereof, and the film according to any one of Embodiments 16 to 19.

[0187] Embodiment 21: The polymer in the coating is a vinylidene chloride homopolymer or a vinylidene chloride copolymer, or a vinyl alcohol homopolymer or a vinyl alcohol copolymer, and the film according to any one of Embodiments 16 to 20.

[0188] Embodiment 22: The vinylidene chloride copolymer comprises, based on the total weight of the copolymer, at least 20 wt%, preferably at least 40 wt%, more preferably at least 50 wt%, more preferably at least 60 wt%, more preferably at least 70 wt%, most preferably at least 80 wt%, of vinylidene chloride monomer, and / or The film according to Embodiment 21, wherein the vinylidene chloride copolymer contains less than 95 wt%, preferably less than 90 wt%, of vinylidene chloride monomer based on the total weight of the copolymer.

[0189] Embodiment 23: The film according to Embodiment 21 or 22, wherein the vinyl alcohol copolymer is a copolymer of vinyl alcohol and vinyl acetate.

[0190] Embodiment 24: The total amount of vinyl alcohol and vinyl acetate monomers in the vinyl alcohol copolymer is, based on the total weight of the copolymer, at least 20 wt%, preferably at least 40 wt%, more preferably at least 50 wt%, more preferably at least 60 wt%, more preferably at least 70 wt%, most preferably at least 80 wt%, and / or The film according to any one of Embodiments 21 to 23, wherein the total amount of vinyl alcohol and vinyl acetate monomers in the vinyl alcohol copolymer is less than 95 wt%, preferably less than 90 wt%, based on the total weight of the copolymer.

[0191] Embodiment 25: The film according to any one of Embodiments 21 to 24, wherein the number of vinyl alcohol monomers in the vinyl alcohol copolymer is at least 80%, preferably at least 95%, and most preferably at least 97% of the total number of vinyl alcohol and vinyl acetate monomers.

[0192] Embodiment 26: The film according to any one of Embodiments 21 to 25, wherein one or more vinyl alcohol monomers in the vinyl alcohol homopolymer or vinyl alcohol copolymer are modified by carboxylation, etherification, acetalization, carbamateization, amination, sulfation, or esterification, and / or one or more vinyl alcohol monomers are bonded to the side chain.

[0193] Embodiment 27: The film according to any one of Embodiments 21 to 26, wherein the vinyl alcohol homopolymer or vinyl alcohol copolymer is crosslinked, preferably by heat, UV, and / or a crosslinking agent.

[0194] Embodiment 28: The film according to Embodiment 27, wherein the crosslinking agent is selected from the group comprising alcohols, linear polyols, branched polyols, aldehydes, amines, polyamines, hydrazides, polyhydrazides, metal salts, acids, and organic acids, and preferably the crosslinking agent is selected from the group comprising ethylene glycol, formaldehyde, acetaldehyde, glyoxal, malondialdehyde, succinidaldehyde, glutaraldehyde, metaxylenediamine, 1,3-bis(aminomethyl)cyclohexane, adipic acid dihydrazide, dodecanedihydrazide, polyol carbonyl adducts, sodium borate, zirconium ammonium carbonate, sodium glyoxylate, malonic acid, succinic acid, adipic acid, boric acid, and sulfosuccinic acid.

[0195] Embodiment 29: The vinylidene chloride copolymer is a copolymer of vinylidene chloride and one or more monomers of formula (I), and / or the vinyl alcohol copolymer is a copolymer of vinyl alcohol, optionally vinyl acetate, and one or more monomers of formula (I),

[0196] [ka] In the formula, each R 1 H, C1-C10 Alkyl, C3-C 10 Cycloalkyl, C1-C 10 Alkoxy, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 Aryl, C1-C9 heteroaryl, nitrile, -OH, halo, -C(O)R 4 , -C(O)OR 4 -OC(O)R 4 -C(O)NHR 4 , and -NHC(O)R 4 It was independently selected from the group that includes it. Each R 2 H, halo, C1-C3 alkyl, -C(O)OR 5 , and -CH2C(O)OR 5 It was independently selected from the group that includes it. Each R 3 H, -C(O)OR 5 , and independently selected from the group including C1-C3 alkyl, Each R 4 H, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 They were independently selected from the group including aryls and C1-C9 heteroaryls. Each R 5 C1-C 10 It is selected independently of alkyl groups. Each C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C1-C 10 Alkoxy, (C1-C5 alkyl)-O-(C1-C5 alkyl), C6-C 10 The film according to any one of embodiments 21 to 28, wherein the aryl and C1-C9 heteroaryl are optionally and independently substituted with one or more substituents independently selected from -OH, oxo, -SO2H, -NO2, and halo.

[0197] Embodiment 30: The film according to any one of Embodiments 21 to 29, wherein the vinylidene chloride copolymer is a copolymer of vinylidene chloride and one or more further monomers, and / or the vinyl alcohol copolymer is a copolymer of vinyl alcohol, optionally vinyl acetate, and one or more further monomers, wherein the one or more further monomers are independently selected from the group including alkenes, acrylic acids, vinyl halides, vinyl amides, styrene, vinyl alcohols, vinyl esters, vinyl ethers, vinyl ketones, maleic acid or maleic acid esters, fumaric acid or fumaric acid esters, itaconic acid or itaconic acid esters, crotonic acid or crotonic acid esters.

[0198] Embodiment 31: The film according to any one of Embodiments 21 to 30, wherein the vinylidene chloride copolymer is a copolymer of vinylidene chloride and one or more further monomers, the one or more further monomers being independently selected from the group comprising ethene, propene, butene, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, vinyl chloride, styrene, methyl vinyl ketone, vinyl alcohol, vinyl acetate, and itaconic acid.

[0199] Embodiment 32: The film according to any one of Embodiments 21 to 31, wherein the vinyl alcohol copolymer is a copolymer of vinyl alcohol, optionally vinyl acetate, and one or more further monomers, the one or more further monomers being independently selected from the group comprising ethene, propene, butene, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hydroxyethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, styrene, methyl vinyl ketone, and itaconic acid.

[0200] Embodiment 33: The film according to any one of Embodiments 16 to 32, wherein the coating comprises a vinylidene chloride homopolymer or a vinylidene chloride copolymer.

[0201] Embodiment 34: The film according to any one of Embodiments 16 to 33, wherein the coating comprises two or more layers, at least one of which comprises the polymer.

[0202] Embodiment 35: The film according to any one of Embodiments 16 to 33, wherein the coating comprises a single layer containing the polymer.

[0203] Embodiment 36: The film according to any one of Embodiments 16 to 35, wherein the polymer film comprises a coating on both outer surfaces, each coating being independently one of those described in any one of Embodiments 16 to 35.

[0204] Embodiment 37: Each of the one or more layers of the polymer film independently contains one or more polymers independently selected from the group including low-density polyethylene (LDPE), low-density linear polyethylene (LLDPE), metallocene low-density linear polyethylene (MLLDPE), ethylene vinyl acetate copolymer (EVA), ethylene butyl acrylate copolymer (EBA), high-density polyethylene (HDPE), polypropylene (PP), thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide (PA), ethylene vinyl alcohol copolymer (EVOH), and / or combinations thereof, and / or The film according to any one of embodiments 16 to 36, wherein at least one of the layers of the polymer film further comprises an IR absorber, an anti-fogging agent, an anti-drip agent, a dustproofing material, an anti-algal material, an adhesion aid, and / or a pigment.

[0205] Embodiment 38: The one or more UV stabilizers are independently selected from the group comprising hindered amine light stabilizers (HALS), UV absorbers, and nickel organic complexes, and / or The one or more UV stabilizers are present in an amount of from 0.1 wt% to 20 wt%, preferably from 0.1 wt% to 10 wt%, and most preferably from 0.1 wt% to 5 wt%, based on the total weight of the layer, of the film according to any one of embodiments 16 to 37.

[0206] Embodiment 39: The polymeric film has from 1 to 100 layers, preferably from 3 to 11 layers, and / or The polymeric film can be obtained by extrusion or co-extrusion, preferably extrusion or co-extrusion of a blown film or a cast film, and / or The film has a total thickness of from 25 μm to 500 μm and a total width of from 1 m to 60 m, of the film according to any one of embodiments 16 to 38.

[0207] Embodiment 40: Use of a coating on at least one outer surface of a polymeric film, wherein the coating comprises at least one layer comprising a polymer, the polymeric film comprises one or more layers, at least one layer comprises one or more UV stabilizers, for reducing the sensitivity of the polymeric film to photo-degradation in the presence of a pesticide, and / or for reducing the permeability of the polymeric film to gases and / or water vapor.

[0208] Embodiment 41: The coating reduces the oxygen permeability of the polymeric film to less than 500 ml / m 2 / bar / day at 23 °C and 0% relative humidity when measured according to EN ISO 15105-2, of the use according to embodiment 40.

[0209] Embodiment 42: An agricultural structure, characterized in that at least a part thereof is covered with the film according to any one of embodiments 16 to 39.

[0210] Embodiment 43: A method of covering an agricultural structure, comprising the step of covering at least a part of the agricultural structure with the film according to any one of embodiments 16 to 39.

[0211] Embodiment 44: A method for producing a film for covering an agricultural structure, comprising: (i) providing a polymer film comprising one or more layers, at least one of said layers comprising one or more UV stabilizers; (ii) depositing a coating on at least one outer surface of said polymer film, said coating comprising at least one layer comprising a polymer such that the film has an oxygen permeability of less than 500 ml / m 2 / bar / day at 23 °C and 0% relative humidity when measured according to EN ISO 15105-2; A method for producing a film, comprising the above steps.

[0212] Embodiment 45: The coating is deposited via dipping, spraying, flexographic printing, plasma, laser, gravure printing, reverse roll, roll-to-roll, knife over all, rod coater, jet printing, or slot die, and / or the outer surface of the polymer film is treated with corona and / or plasma prior to deposition of the coating, and / or The method for producing a film according to Embodiment 44 further comprises producing the polymer film via blow or cast extrusion or coextrusion.

[0213] Embodiment 46: A film according to any one of Embodiments 16 to 39, obtainable by the method according to Embodiment 44 or 45.

Claims

[Claim 1] A film for covering agricultural structures, (a) A polymer film having one or more layers, wherein at least one of the layers contains one or more UV stabilizers, (b) A coating on at least one outer surface of the polymer film, wherein the film has a density of 500 ml / m² at 23°C and 0% relative humidity when measured according to EN ISO 15105-2. ２ A coating comprising at least one layer containing a polymer, having an oxygen permeability of less than / bar / day, A film containing this material.

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