WO2018016617A1 - Fluorine-containing agricultural laminated film and agricultural covering material using same - Google Patents

Abstract

The present invention provides: a fluorine-containing agricultural laminated film that allows a sufficient amount of light into a protected horticulture greenhouse while enabling the light to be softened by scattering, and that provides excellent workability during deployment thereof; and an agricultural covering material using same. This fluorine-containing agricultural laminated film is provided with a thermoplastic resin layer on one surface of a fluorine-based resin layer, has unevenness on the surface of the thermoplastic resin layer, and is provided with an anti-stick layer on the uneven surface.

Description

Fluorine-containing laminated film for agriculture and agricultural coating material using the same

The present invention relates to an agricultural fluorine-containing laminated film, more specifically, an agricultural fluorine-containing laminated film having light scattering properties, and an agricultural covering material using the same.

In horticultural house cultivation, it is known that the light transmittance into the house has a significant effect on the growth of the crop, and it is given to the crop depending on whether the contribution of parallel light or scattered light in the total transmitted light is large. The impact is different. In addition, when the crops are exposed to intense light during the summer heat, problems such as sunburn and poor coloring occur.

In response to such problems, attempts have been made to scatter light such as sunlight by a house covering material such as a film to reduce shadows in the community of cultivated plants and to prevent sunburn. By scattering light rays such as sunlight, light can easily enter the corners of the house and the bottom of the crop, which is beneficial to the cultivation environment and crop growth. In addition, since the light in the house becomes softer than the transparent type film due to the scattering of sunlight, it is possible to prevent leaf burning and actual burning of crops and further improve the working environment. As a method for scattering light, it is possible to cover the house with a covering material using a film containing substances having different refractive indexes of light.

For example, Patent Document 1 states that at least one surface of a polyolefin resin film is formed with a coating derived from a matte composition mainly composed of a thermoplastic resin binder and inorganic and / or organic particles. A characteristic matt polyolefin resin coating material has been proposed.

Patent Document 2 discloses an agricultural film comprising a layer containing linear low-density polyethylene, a layer containing ethylene-vinyl acetate copolymer, and a layer containing polyethylene. Agricultural films have been proposed in which either or both of a layer containing density polyethylene and a layer containing ethylene-vinyl acetate copolymer contain mica.

Also, coating materials such as satin film may be used for scattering.

Patent Document 3 proposes a single-layer fluororesin film in which unevenness processing is performed on a fluororesin film in which the ratio of scattered light with a scattering angle of 5.5 to 10 ° is 5% or more with respect to the total transmitted light. ing.

Japanese Patent Laid-Open No. 11-137095 JP 2014-195424 A International Publication No. 2010/047338

However, in Patent Document 1, when a stretch test is performed for a long period of time, the adhesion between the polyolefin resin film and the acrylic resin coating film deteriorates with time, and the acrylic resin gradually becomes exposed while being exposed outdoors for a long time. There was a problem that the resin layer was peeled off and the durability was poor.

Moreover, in the film obtained by patent document 2, in order to obtain the target scattered light performance, you have to increase the addition amount of a light-scattering agent, and also reduce the transmission amount of the light ray from sunlight in that case. Therefore, problems such as poor growth of crops may occur.

Since the film proposed in Patent Document 3 uses a hard fluororesin such as ETFE (ethylene-tetrafluoroethylene) which is not compatible with other resins, it is very difficult to laminate with other resins. In addition, since the flexibility is low, the workability of the extension is poor and the cost is high, and there is a problem that the facility horticulture house that can be constructed is limited.

The present invention has been made in view of the above circumstances, and it is possible to soften light by scattering while taking a sufficient amount of light into a facility horticultural house, and to use an agricultural fluorine-containing laminated film excellent in spreading workability and the same. It aims at providing the covering material for agriculture which becomes.

According to some embodiments of the present invention, a thermoplastic resin layer is provided on one surface of the fluororesin layer, the surface of the thermoplastic resin layer has irregularities, and the droplet layer is formed on the irregular surface. An agricultural fluorine-containing laminated film comprising:

As a result of intensive studies by the present inventors, a thermoplastic resin layer is disposed on one surface of a fluorine-based resin layer excellent in weather resistance, and a specific uneven shape is formed on the surface of the thermoplastic resin. It has been found that it has high light transmittance and moderate light scattering properties while maintaining the properties of a fluororesin excellent in weather resistance, and is excellent in stretch workability.

Hereinafter, various embodiments of the present invention will be exemplified. The following embodiments can be combined with each other.

Preferably, the droplet layer contains a layered silicate, a polymer binder, and a light stabilizer.
Preferably, the thermoplastic resin layer is a resin layer composed of a single layer or multiple layers.
Preferably, the arithmetic average roughness Ra of the unevenness formed on the surface of the thermoplastic resin layer is 1.4 μm ≦ Ra ≦ 3.2 μm, and the average length RSm of the roughness curve element is 25 μm ≦ RSm ≦ 120 μm. It is.
Preferably, the thermoplastic resin layer contains a light scattering agent.
Preferably, in the agricultural fluorine-containing laminated film, the ratio of scattered light having a scattering angle of 5 to 15 ° is 10% or more with respect to the total transmitted light.

According to another aspect of the present invention, there is provided an agricultural covering material using the above-mentioned agricultural fluorine-containing laminated film.

The agricultural fluorine-containing laminated film of the present invention is a laminated film having a fluorine-based resin layer having excellent weather resistance that can be used as a covering material for a facility or horticultural house. Can be relieved and has excellent workability.

It is a figure explaining the test method (in-house method) for evaluating the drip property using a water bath.

The agricultural fluorine-containing laminated film of the present invention comprises a thermoplastic resin layer on one surface of a fluorine-based resin layer, has an uneven surface on the surface of the thermoplastic resin layer, and a droplet layer on the uneven surface. Is provided.
Hereinafter, embodiments of the present invention will be described in detail.

<Fluorine resin layer>
A film made of a fluororesin is used as the fluororesin layer as a laminating film capable of imparting antifouling performance to an agricultural film. As the fluororesin constituting the fluororesin layer, polyvinylidene fluoride resin (PVDF) is particularly preferable because it is required to have good compatibility with other resins and high flexibility.

The polyvinylidene fluoride resin is preferably a copolymer containing vinylidene fluoride as a main component and other fluorine-containing monomer as a monomer unit in consideration of flexibility for stretching work. A copolymer obtained by copolymerizing another fluorine-containing monomer in a range of up to 50% by mass as a body unit may be used. Examples of the fluorine-containing monomer that forms a copolymer with vinylidene fluoride include known fluorine-containing monomers such as hexafluoropropylene, tetrafluoroethylene, hexafluoroisobutylene, and various fluoroalkyl vinyl ethers. Since it can be increased, hexafluoropropylene is preferable as the fluorine-containing monomer to be copolymerized with vinylidene fluoride. In the case of a vinylidene fluoride-hexafluoropropylene copolymer, the proportion of monomer units based on vinylidene fluoride is 80 to 90% by mass, and the unit of monomers based on hexafluoropropylene is 10 to 20% by mass. It is more preferable that it is a copolymer contained in More preferably, the vinylidene fluoride-hexafluoropropylene copolymer is a random copolymer. The polyvinylidene fluoride resin may be composed of only one kind of copolymer, or may be a mixture of two or more kinds of copolymers.

The thickness of the fluororesin layer is preferably in the range of 5 to 120 μm, more preferably 5 to 100 μm. If it is less than 5 μm, the weather resistance may be insufficient. Moreover, when it becomes thicker than 120 micrometers, it is unpreferable also from a cost surface.

For example, titanium oxide, zinc oxide, cesium oxide, iron oxide, and many other types of ultraviolet blocking agents to be added to the fluororesin layer can be used. Among these, it is preferable to use titanium oxide which is difficult to elute.

The addition amount of the ultraviolet blocking agent is preferably in the range of 1 to 5 parts by mass with respect to 100 parts by mass of the resin component, for example, polyvinylidene fluoride resin. If the addition amount is less than 1 part by mass, the ultraviolet shielding effect may be lowered, and if it exceeds 5 parts by mass, the transparency of the film may be lost.

In addition to UV blockers, fluorine-based resin layers include stabilizers, dispersants, antioxidants, matting agents, surfactants, antistatic agents, fluorine-based surface modifiers, and processing aids as necessary. It is also possible to add various additives such as those as long as their dispersibility is not impaired.

<Thermoplastic resin layer>
A known thermoplastic resin can be used for the thermoplastic resin layer. For example, polyolefin, polymethacrylic ester resin, polystyrene, ABS resin, AS resin, polyamide, polyimide, polyester, etc. are mentioned. Among them, polyolefin from the viewpoint of film forming property and flexibility, or polymethacrylic acid from the point of weather resistance Ester resins can be used preferably.

Polyolefins include α-olefin homopolymers, copolymers with different monomers based on α-olefins, and polyunsaturations such as conjugated or non-conjugated dienes based on α-olefins. For example, high density, low density or linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-4-methyl-1-pentene. Examples thereof include a copolymer, an ethylene-vinyl acetate copolymer, and an ethylene-acrylic acid copolymer. Among these, low density polyethylene having a density of 0.890 to 0.935 is preferable from the viewpoint of transparency, weather resistance, and price.

As polymethacrylate resin, in addition to homopolymer of methyl methacrylate (polymethyl methacrylate), methyl methacrylate as the main component, acrylic acid ester and methacrylic acid ester other than methyl methacrylate are less than 50% by mass. Examples thereof include a copolymer to be contained, and a mixture of two or more of these polymers. Examples of the acrylate ester include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, and examples of methacrylic acid esters other than methyl methacrylate include ethyl methacrylate and propyl methacrylate. it can. Further, the copolymer is not limited to a random copolymer, and for example, a graft copolymer or the like is used. A copolymer obtained by graft polymerization of a monomer mainly composed of methyl methacrylate on an acrylic saturated crosslinked rubber is also preferably used. Among these polymethacrylic acid ester resins, polymethyl methacrylate is particularly preferably used.

For the thermoplastic resin layer, a stabilizer, a dispersant, an antioxidant, a matting agent, a surfactant, an antistatic agent, a fluorine-based surface modifier and a processing aid, an ultraviolet blocker and an ultraviolet ray as necessary. It is also possible to add various additives such as an absorbent as long as their dispersibility and transparency as a film are not impaired.

The thermoplastic resin layer may be a single layer or a laminated structure, and may have a thermoplastic adhesive resin layer. The resin used for the adhesive resin layer may be any resin as long as it can adhere the fluorine-based resin layer and other layers contained in the thermoplastic resin layer, and various conventionally known ones can be used. Examples thereof include acid-modified polyolefin resins including unsaturated carboxylic acid modification, chlorinated polyolefin resins, thermoplastic elastomers, and the like.

The thickness of the adhesive resin layer is preferably in the range of 5 to 20 μm, more preferably 10 to 20 μm from the viewpoint of providing sufficient adhesive force.

In the adhesive resin layer, various additives such as stabilizers, antioxidants, processing aids, UV blockers and UV absorbers are added to the adhesive resin layer as necessary, as long as their dispersibility and transparency as a film are not impaired. It is also possible to add at.

<Flowing layer>
The droplet layer is formed by applying a colloidal layered silicate and a droplet agent containing a polymer binder, a light stabilizer or an ultraviolet absorber. The droplet agent for forming the droplet layer is preferably transparent without becoming cloudy. A transparent coating film can be formed by using a droplet having a layered silicate dispersed colloidally and a colloid of nanometer size. The particle size of the layered silicate is usually 10 to 1000 nm, preferably 10 to 100 nm.

The layered silicate is at least one selected from, for example, mica and smectite. Examples of mica include vermiculite. Examples of the smectite include montmorillonite, iron montmorillonite, beidellite, saponite, nontronite, hectorite, stevensite, and socosite. The layered silicate is preferably a synthetic layered silicate, particularly preferably a synthetic smectite.

The polymer binder is not particularly limited as long as it is transparent when mixed with the above-mentioned layered silicate and can stably fix the droplet layer on the film, but is alcohol-soluble nylon resin, acrylic resin phenol resin Etc., and preferably an alcohol-soluble nylon resin. When these polymer binders are used, it is possible to form a droplet layer that is not easily peeled off even by friction by a stretching operation while ensuring transparency.

The mixing ratio of the layered silicate and the polymer binder is not particularly limited as long as transparency and fixing stability are ensured, but 2 to 60 parts by weight of the layered silicate with respect to 100 parts by weight of the polymer binder. It can be contained in an amount of preferably 5 to 20 parts by mass. When the amount is less than 2 parts by mass, the contact angle of water becomes high and the dropping property is low, and when it exceeds 60 parts by mass, the transparency is lowered.

In order to provide weather resistance to the droplet layer, it is preferable to blend a light stabilizer, and known ones can be used. As the light stabilizer, one that captures the active species at the start of photodegradation in the resin and prevents photooxidation can be used. Specifically, one or a combination of two or more selected from hindered amine compounds, hindered piperidine compounds, and the like can be used. Among these, it is preferable to use a hindered amine compound. These light stabilizers do not easily become emulsions and are excellent in coating film workability.

The thickness of the droplet layer is preferably 0.2 to 0.8 μm, and more preferably 0.4 to 0.6 μm. When the film thickness of the droplet layer is less than 0.2 μm, the droplet droplet performance is poor, and when it is thicker than 0.8 μm, the droplet droplet performance itself is not affected but the productivity may be inferior.

<Fluorine-containing laminated film for agriculture>

In the agricultural fluorine-containing laminated film of the present invention, as a form for scattering the light transmitted through the film, at least one of the resin layers constituting the film is formed with irregularities, and at least the resin layer constituting the film The form in which the light-scattering agent is contained in one and the form which compounded them are mentioned. Preferably, irregularities are formed on the surface of the resin layer on which the droplet layer is provided, that is, the outermost surface of the laminated film, and the droplet layer is provided on the surface of the resin layer on which the irregularities are formed.
In an exemplary embodiment of the present invention, the agricultural fluorine-containing laminated film includes a thermoplastic resin layer on one surface of the fluororesin layer, and does not face the fluororesin layer of the thermoplastic resin layer. The surface of the thermoplastic resin layer which is a surface and is the outermost surface of the agricultural fluorine-containing laminated film has irregularities, and a drip layer is provided on the surface having the irregularities.

In the agricultural fluorine-containing laminated film of the present invention, the ratio of scattered light of 5 to 15 ° of scattered light is 10% or more, preferably 15% or more, more preferably 25% or more with respect to the total transmitted light. If the ratio of the scattered light of 5 to 15 ° of scattered light is 8% or more with respect to the total transmitted light, it is possible to reduce the leaf burn and actual burn of the crop. However, the scattered light in this invention shows the light which permeate | transmitted and scattered through the film.

Further, the arithmetic average roughness Ra of the irregularities formed on the surface of the thermoplastic resin layer is preferably 1.4 to 3.2 μm, and more preferably 2.5 to 3.2 μm. If Ra is 1.4 or more, it is likely to be an agricultural fluorine-containing laminated film having the desired scattered light. On the other hand, if Ra is 3.2 or more, the ratio of scattered light having a scattering angle exceeding 15 ° increases, and transmitted light is scattered too much, so that sufficient light cannot reach the crop.

The arithmetic average roughness Ra is obtained by extracting only the reference length (L) from the roughness curve in the direction of the average line, and setting the X axis in the direction of the average line of the extracted portion and the Y axis in the direction perpendicular to the X axis. When the roughness curve is expressed by Y = f (X), the value obtained by the following equation (1) is expressed in μm.

Further, the average length RSm of the roughness curve element is preferably 25 μm to 120 μm, and more preferably 30 μm to 100 μm. When RSm is in the range of 25 μm to 120 μm, the ratio of scattered light having a scattering angle of 5 to 15 ° in the total transmitted light can be increased, and high transparency can be maintained.

For the average length RSm of the roughness curve element, only the reference length (L) is extracted from the roughness curve in the direction of the parallel line, and the average length of the contour curve elements within the range is calculated by the following equation (2). It is determined and expressed in μm units.

The arithmetic average roughness Ra of the surface irregularities and the average length RSm of the roughness curve elements are obtained according to JIS B 0601-2001.

As an example of the method for bringing the surface roughness of the agricultural fluorine-containing multilayer film of the present invention into a predetermined range, a metal cooling roll and a rubber roll whose surface was processed to be uneven at the time of taking were arranged and extruded from the lip mouth of a T-shaped die. There is a method of transferring the convex portion and / or concave portion to the surface of the film while pinching the molten resin between the rolls and solidifying by cooling.

The agricultural fluorine-containing laminated film of the present invention may contain a light scattering agent. The light scattering agent may be contained in the fluororesin layer, the thermoplastic resin layer, or any resin layer. As the light scattering agent, for example, mica, silica, talc and the like can be used as appropriate.

The average particle diameter of the light scattering agent used in the present invention is preferably 2 to 40 μm, more preferably 2 to 25 μm. If the particle diameter of the light scattering agent is smaller than 2 μm, the ratio of scattered light tends to be small, and if the particle diameter is larger than 40 μm, the total light transmittance of the film tends to be small.

The agricultural fluorine-containing laminated film of the present invention preferably has a total thickness in the range of 40 to 150 μm, more preferably 50 to 130 μm. If the total thickness is too thin, the desired long-term stretchability may not be ensured when used as a covering material for a greenhouse. On the other hand, if the total thickness is too thick, the handling property at the time of stretching is poor and the cost is increased.

As long as the effect of the present invention is not impaired, a mode in which a laminate film is formed by making two or more layers of a fluororesin layer or a thermoplastic resin layer itself between a fluororesin layer and a thermoplastic resin layer, It is included in the scope of the present invention.

The dynamic elastic modulus of the agricultural fluororesin film of the present invention is preferably in the range of 150 to 750 MPa, more preferably 200 to 700 MPa, and further preferably 220 to 550 MPa. When the dynamic elastic modulus is smaller than 150 MPa, the film does not have a proper waist and is very difficult to stretch. When the tensile modulus is greater than 750 MPa, the film is hard and cannot be applied well when it is stretched in the house.

<Method for producing fluorine-containing laminated film for agriculture>
Next, the manufacturing method of the agricultural fluorine-containing laminated | multilayer film of this invention is demonstrated.

First, a laminated film in which a thermoplastic resin layer is laminated on a fluorine resin layer via an adhesive resin layer can be produced by a conventionally known method. For example, each layer is formed separately in advance and laminated, or thermocompression-pressing, a laminated film of a fluororesin layer and an adhesive resin layer is formed in advance, and a thermoplastic resin is formed on the surface of the adhesive resin layer Examples thereof include a method of coating and laminating layers, and a method of laminating and forming each resin layer by a coextrusion method. Of these, the production by the coextrusion method is most preferable from the viewpoint of economy and production stability.

By applying the above-mentioned liquid drop agent on the surface of the laminated film thus obtained on the thermoplastic resin layer side and drying, the agricultural fluorine-containing laminated film of the present invention having the liquid drop layer is obtained.

A well-known method can be used for the method of applying the droplet layer. Examples thereof include coat coating, roller coating, hand coating, spin coating, coating by various printing methods, bar coating, die coating, spray coating, and the like.

When forming the droplet layer, applying a surface treatment to the surface of the laminated film on the thermoplastic resin layer side not only improves the applicability, but also improves the adhesion of the droplet layer. preferable. As the surface treatment method, various methods such as corona discharge treatment, plasma treatment, and high-frequency sputter etching treatment are used.

The heating temperature and time for drying are not particularly limited. The heating temperature can be, for example, 50 to 90 ° C. The time can be, for example, 1 to 60 minutes. The heating temperature and time are preferably set in consideration of the heat resistance temperature of the object to be coated.

<Agricultural coating materials>
The agricultural covering material of the present invention uses the agricultural fluorine-containing laminated film of the present invention. The agricultural fluorine-containing laminated film of the present invention softens the light introduced into the house, prevents leaf burning without impeding crop growth, suppresses temperature rise in the house, and is excellent in weather resistance and spreading workability. The agricultural covering material according to the present invention using can be suitably used as a covering material for a green house.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In addition, the raw material used in the Example is as follows.

[Raw materials]
<Fluorine resin layer>
(Fluorine resin)
・ Vinylidene fluoride-hexafluoropropylene copolymer “Kyner Flex 2800-20” (manufactured by Arkema Co., Ltd .: hexafluoropropylene / vinylidene fluoride = 10/90)
-Vinylidene fluoride homopolymer "Kyner K720" (manufactured by Arkema Co., Ltd.)
・ Ethylene-tetrafluoroethylene copolymer "Fluon ETFE C-88AX" (Asahi Glass Co., Ltd.)

(UV blocker)
Titanium oxide "TTO-55 (D)" (Ishihara Sangyo Co., Ltd.)

<Thermoplastic resin layer>
(Polymethacrylate resin)
“HI-PET HBS000” (manufactured by Mitsubishi Rayon Co., Ltd.) A polymethacrylate resin containing a rubber component of butyl acrylate (n-BA) and butyl methacrylate (BMA). MFR (230 ° C, 3.8kg load) 4-7 (g / 10min)

(Acid-modified polyolefin resin)
“Admer SE810” (manufactured by Mitsui Chemicals), MFR (conditions: 230 ° C., 3.8 kg load) 7.3 (g / 10 min)

(Polyolefin resin)
Special LLDPE resin “NC566A” (manufactured by Nippon Polyethylene Co., Ltd.) Density 0.918 g / cm ³ , MFR (conditions: 230 ° C., 3.8 kg load) 3.8 (g / 10 min)

(Light scattering agent)
“Mica A-21S” (manufactured by Yamaguchi Mica Co., Ltd.) average particle size 23 μm, aspect ratio 70

<Drip agent>
“Rakulein B1” manufactured by Daiwa Steel Co., Ltd. (containing synthetic smectite as colloidal layered silicate and methoxymethylated nylon as polymer binder, containing 10 parts by weight of layered silicate with respect to 100 parts by weight of polymer binder) And a light stabilizer (hindered amine light stabilizer).

<Example 1>
Using the raw material vinylidene fluoride-hexafluoropropylene copolymer as the fluorine resin layer and the polymethacrylic acid ester resin as the thermoplastic resin layer, each using a single screw extruder of φ40 mm, feed block Fluorine-based resin layer (thickness: 90 μm) by using a metal cooling roll that has been co-extruded by the method, and surface unevenness on the metal cooling roll is pressed against the thermoplastic resin layer, and thermoplastic resin A laminated film laminated in the order of layers (thickness 10 μm) was obtained.
Next, after corona treatment was applied to the surface of the laminated film on which the irregular shape on the thermoplastic resin layer side was formed, a drop agent was applied to produce a laminated film having a droplet layer (thickness 0.5 μm). .

Various evaluations of agricultural fluorine-containing laminated films were performed by the following methods. The results are shown in Table 1.

(1) Optical properties (total light transmittance)
The agricultural fluorine-containing laminated film was cut into 5 cm square, and measured using “NDH7000” manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with JIS K 7361.

(HAZE)
The HAZE value was measured using “NDH7000” manufactured by Nippon Denshoku Industries Co., Ltd. in accordance with JIS K 7136 after cutting out an agricultural fluorine-containing laminated film into a 5 cm square.

(Measurement of outgoing distribution of transmitted light)
The outgoing distribution of transmitted light is 0-60 ° relative to the outgoing distribution when light is incident perpendicularly to the film surface with “Automatic Variable Angle Photometer GP-200” manufactured by Murakami Color Research Co., Ltd. It calculated by measuring every 0.5 degrees in the range.

(2) Surface roughness (arithmetic average roughness Ra, average length RSm of roughness curve elements)
The arithmetic average roughness Ra of the surface irregularities and the average length RSm of the roughness curve element were measured using an ultra-deep shape measurement microscope “VK-8510” (manufactured by Keyence Corporation), and the objective lens × 20 times and the measurement interval Under a measurement condition of 0.5 μm, a roughness curve Y = f (X) with a reference length (L) = 900 μm is measured along the longitudinal direction of the multilayer film, and is defined in JIS B 0601-2001 from the curve. It was measured based on the calculation formula (the above formulas (1) and (2)).

(3) Drip characteristics (in-house method)
As shown in FIG. 1, in the evaluation of the drip property, the surface of the laminated film 3 having a drip layer at the opening of the water bath 1 in which 50 ° C. hot water 2 is circulated has a gradient of 15 ° with respect to the water surface. The film appearance after 6 months was visually observed and evaluated as follows. In this embodiment, the “surface to be evaluated” is a surface provided with a droplet layer.
Excellent: There is no adhesion of water droplets, and the film is uniformly wet.
Good: Water droplets adhere to an area of less than 25% of the entire film.
Good: Water droplets adhere to an area of 25% or more and less than 75% of the entire film.
Impossible: Water droplets adhere to an area of 75% or more of the entire film.

(4) Stretching workability The stretching workability was evaluated as follows as the degree of difficulty of construction in which a film is stretched and fixed to a frame using a fixing part.
Excellent: Easy to install.
Impossible: Construction is possible, but the work is hard and poor in workability, and wrinkles tend to occur on the film.

<Examples 2 to 7>
A laminated film having a fluidized droplet layer (thickness 0.5 μm) was prepared and evaluated in the same manner as in Example 1 except that the surface roughness was changed as shown in Table 1. The results are shown in Table 1.

<Example 8>
A thermoplastic resin layer is prepared by blending with a tumbler together with 2 parts by weight of the light scattering agent with respect to 100 parts by weight of the polymethacrylic ester resin used as a raw material, and kneading with a φ30 mm twin screw extruder. A compound for was obtained. A laminated film having a flow droplet layer (thickness: 0.5 μm) was prepared and evaluated in the same manner as in Example 1 except that the compound was used as the thermoplastic resin layer. The results are shown in Table 1.

<Example 9>
The raw material vinylidene fluoride-hexafluoropropylene copolymer as the fluorine-based resin layer, the above-mentioned acid-modified polyolefin resin as the first thermoplastic resin layer, and the above-mentioned polyolefin-based material as the second thermoplastic resin layer By using a resin, a fluorine resin layer and a first thermoplastic resin layer, respectively, using a φ40 mm single screw extruder and a second thermoplastic resin layer using a φ65 mm single screw extruder, by a feed block method. By co-extrusion and pulling with the metal cooling roll so that the surface irregularities on the metal cooling roll are pressed against the second thermoplastic resin layer, the fluororesin layer (thickness 70 μm), the first thermoplastic resin layer (thickness 10 μm) ), A laminated film laminated in the order of the second thermoplastic resin layer (thickness 20 μm) was obtained.
Next, in the same manner as in Example 1, a laminated film having a droplet layer (thickness: 0.5 μm) on the surface of the laminated film on which the concave and convex shape on the second thermoplastic resin layer side was formed was evaluated. The results are shown in Table 1.

<Examples 10 to 15>
A laminated film having a droplet layer (thickness 0.5 μm) was prepared and evaluated in the same manner as in Example 9 except that the surface roughness was changed as shown in Table 1. The results are shown in Table 1.

<Example 16>
Blended with a tumbler together with 2 parts by mass of the light scattering agent with respect to 100 parts by mass of the polyolefin resin as a raw material, kneaded by a twin screw extruder with a diameter of 30 mm for the second thermoplastic resin layer I got a compound. A laminated film having a flow droplet layer (thickness 0.5 μm) was prepared and evaluated in the same manner as in Example 9 except that the above compound was used as the thermoplastic resin layer. The results are shown in Table 1.

<Comparative Example 1>
A laminated film was prepared and evaluated in the same manner as in Example 1 except that the droplet layer was not provided. The results are shown in Table 1. In this comparative example, the “surface to be evaluated” in the evaluation of the droplet property is a surface on which the droplet layer is provided in Example 1, that is, a surface having irregularities.

<Comparative example 2>
Using the above-mentioned raw material vinylidene fluoride homopolymer as the fluorine-based resin layer, extrusion was performed using a single-screw extruder of φ40 mm, and an unevenness was formed on one surface by pulling with a metal cooling roll subjected to surface unevenness processing. A single layer film of a fluororesin layer (thickness 100 μm) was obtained.
Next, a corona treatment is applied to the surface of the above-mentioned raw material vinylidene fluoride homopolymer monolayer film on which the concavo-convex shape is formed, and then a dropping agent is applied to have a dropping layer (thickness 0.5 μm). A single layer film was prepared and evaluated. The results are shown in Table 1.

<Comparative Example 3>
A single layer having a droplet layer (thickness 0.5 μm) was prepared in the same manner as in Comparative Example 2 except that the raw material ethylene-tetrafluoroethylene copolymer was used instead of the vinylidene fluoride homopolymer as the fluorine resin fat layer. A layer film was prepared and evaluated. The results are shown in Table 1.

1: Water bath 2: Hot water 3: Film

Claims (7)

An agricultural fluorine-containing laminated film comprising a thermoplastic resin layer on one surface of a fluorine-based resin layer, irregularities on the surface of the thermoplastic resin layer, and a droplet layer on the irregular surface. 2. The agricultural fluorine-containing laminated film according to claim 1, wherein the droplet layer contains a layered silicate, a polymer binder, and a light stabilizer. The agricultural fluorine-containing laminated film according to claim 1 or 2, wherein the thermoplastic resin layer is a resin layer composed of a single layer or multiple layers. The arithmetic average roughness Ra of the irregularities formed on the surface of the thermoplastic resin layer is 1.4 μm ≦ Ra ≦ 3.2 μm, and the average length RSm of the roughness curve element is 25 μm ≦ RSm ≦ 120 μm The agricultural fluorine-containing laminated film according to any one of claims 1 to 3, wherein: The agricultural fluorine-containing laminated film according to any one of claims 1 to 4, wherein the thermoplastic resin layer contains a light scattering agent. The agricultural fluorine-containing laminated film according to any one of claims 1 to 5, wherein the ratio of scattered light having a scattering angle of 5 to 15 ° is 10% or more with respect to the total transmitted light. . An agricultural covering material using the agricultural fluorine-containing laminated film according to any one of claims 1 to 6.

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