JP2020188734A - Agricultural resin film - Google Patents

Abstract

To provide an agricultural resin film having excellent workability in performing ventilation operation while maintaining high transparency.SOLUTION: An agricultural resin film including transparent fine particles and base resin, in which a difference between the refractive index of the transparent fine particles and the refractive index of the base resin is 0.02 or less.SELECTED DRAWING: None

Description

The present invention relates to an agricultural resin film. More specifically, the present invention relates to an agricultural resin film having excellent transparency and flexibility, less likely to adhere to each other when the films are overlapped with each other, and having good workability.

Traditionally, farmers cultivating useful crops have widely used a method of spreading transparent film materials in greenhouses (agricultural greenhouses), tunnels, etc. and cultivating crops in them for the purpose of promoting crop cultivation. It has been adopted.
Conventionally, as such an agricultural film, a soft and hard transparent film such as a vinyl chloride resin film, a polyethylene resin film, a polyethylene terephthalate resin film, and a fluorine resin film has been used. Such films are required to be transparent in consideration of the influence on crops, and in recent years, development of films that can be used for long-term extension such as 3 years or more is also active.

However, since these resin films are soft and elastic, they can be stretched easily in any shape of house, but on the other hand, they have the property of adhering to each other when they overlap (called stickiness). There is a drawback that it occurs. This drawback is the ventilation work of the film (the operation of winding and unwinding the film on the side of the house, or the operation of hoisting and lowering the film of the tunnel in order to adjust the temperature inside the house or tunnel. ), It takes a lot of time and effort. In particular, when the films are overlapped in a wet state due to rainfall or humidity, the degree of adhesion is strong, which may cause a big problem.

In order to solve such a drawback, Patent Document 1 proposes a method of adding a specific amide compound and a specific inorganic fine powder, but the film on the outer surface is significantly contaminated and the ventilation workability is sufficiently satisfied. It wasn't possible. Further, there is a drawback that the transparency is impaired by the addition of the inorganic fine powder.

Further, Patent Document 2 proposes a soft vinyl chloride resin film for agriculture in which specific inert solid fine particles are added to form an acrylic resin film on one side of the film. Further, Patent Document 3 proposes an agricultural side covering material in which a synthetic resin layer such as an acrylic resin is formed on at least one side of a vinyl chloride resin film having a thickness of 0.20 mm or more.
However, due to the effect of the acrylic film, the stains on the film are easily washed away by rainfall, etc., which is improved. There was a drawback.

JP-A-58-69240 Japanese Unexamined Patent Publication No. 62-178341 Japanese Unexamined Patent Publication No. 8-205689

An object of the present invention is to provide an agricultural resin film having good workability during ventilation work while maintaining high transparency.

That is, the present invention
[1] An agricultural resin film containing transparent fine particles and a base resin, wherein the difference between the refractive index of the transparent fine particles and the refractive index of the base resin is 0.02 or less. Agricultural resin film.
[2] The agricultural resin film according to [1], wherein the difference between the refractive index of the transparent fine particles and the refractive index of the base resin is 0.01 or less.
[3] The transparent fine particles are contained in an amount of 0.2 parts by weight to 1.0 part by weight with respect to 100 parts by weight of the thermoplastic resin constituting the base resin, and the average particle size of the transparent fine particles is 200 nm or more and 30 μm or less. The agricultural resin film according to [1] or [2].
[4] The agricultural resin film according to any one of [1] to [3], wherein the transparent fine particles are organic fine particles containing an acrylic resin as a main component.
[5] The agricultural resin film according to any one of [1] to [4], wherein the thermoplastic resin constituting the base resin is a vinyl chloride resin.
Regarding.

By using the agricultural film of the present invention, it is possible to achieve both workability and transparency, which have been problems in the past. Therefore, it becomes easier to visually check the growing state of the crop from the outside of the film, or it is possible to reduce the burden on the farmer during the ventilation work.

Hereinafter, the present invention will be described in detail, but the present invention is not limited to such aspects.

The agricultural resin film in the present invention is applied to either a so-called exterior agricultural film used by spreading and covering an agricultural house (greenhouse) or a tunnel, or a lining agricultural film further spread in a house or a tunnel. You may.
The agricultural film of the present invention is a film made of a base resin in which an additive is mixed with a thermoplastic resin, but the agricultural film of the present invention may be a single layer or a multi-layered film.

In the present invention, it is important to contain transparent fine particles having a refractive index very close to that of the base resin as a matrix, which makes it possible to improve workability while being transparent as an agricultural film. Become.

The transparent fine particles in the present invention are not particularly limited as long as they have a refractive index close to that of the base resin described later, but for example, inorganic fine particles such as silica silica sol and / or alumina sol, or a polymethylmethacrylate. Examples thereof include organic fine particles such as polystyrene, nylon 12, silicone, and copolymers thereof.
Of these, the latter organic fine particles are preferably used. This is because the organic fine particles soften with temperature during film production and thus do not easily damage the production equipment, and are hard during use, so that workability can be improved at the same time.
Further, as the organic fine particles, the organic fine particles containing an acrylic resin as a main component are particularly preferable because they are suitable for transparency and thermal properties and the refractive index can be easily adjusted. Here, the fact that the acrylic resin is the main component means that the main skeleton of the organic fine particles is composed of fine particles made of acrylic resin, and it is copolymerized with an arbitrary resin in order to match the refractive index with the thermoplastic resin. A polymer may be formed.

The transparent fine particles are preferably selected from a range in which the primary average particle size is 200 μm to 30 μm, preferably 1 μm to 20 μm, and in this range, two or more kinds of transparent fine particles having different average particle sizes are selected. It may be used in combination. If the average particle size is too large, the particles are likely to be detached during use, and if the average particle size is too small, the particles may be easily damaged from the interface between the particles and the resin. It is not preferable because it becomes difficult to put out and sufficient workability cannot be obtained.

As the transparent fine particles, the difference in refractive index from the base resin is preferably in the range of 0.02 or less, preferably 0.01 or less. If the difference in refractive index is greater than or equal to the range, sufficient transparency cannot be obtained, which is not preferable.

The content of the transparent fine particles in the agricultural resin film is 0.2 parts by weight to 1.0 parts by weight, preferably 0.3 parts by weight to 0 parts by weight with respect to 100 parts by weight of the thermoplastic resin constituting the base resin. 0.8 parts by weight. When the content of the transparent fine particles is 1.0 part by weight or less, the film is less likely to be damaged from the interface between the particles and the base resin, and the film is not fragile. Further, when the content of the transparent fine particles is 0.2 parts by weight or more, the particles are easily exposed and sufficient workability can be obtained, which is preferable.

In the present invention, the base resin refers to a resin composition (also referred to as "base resin composition") in which an additive is added to a thermoplastic resin.
The thermoplastic resin constituting the base resin of the present invention includes a vinyl chloride resin usually used for agricultural films, a polyolefin resin such as polyethylene and an ethylene-vinyl acetate copolymer, and a polyester resin such as polyethylene terephthalate. Examples thereof include resins, but in the present invention, it is particularly preferable to use vinyl chloride-based resins. This is because the vinyl chloride resin is excellent in transparency and flexibility, but has the property of easily adhering when the films overlap each other.
The vinyl chloride-based resin refers to a copolymer containing vinyl chloride as a main component in addition to polyvinyl chloride. Examples of the monomer compound that can be copolymerized with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itaconic acid, acrylic acid, methacrylic acid, and vinyl acetate. These vinyl chloride resins may be produced by any of conventionally known production methods such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, and a bulk polymerization method.
Thermoplastic resins include known plasticizers, lubricants, heat stabilizers, organic phosphates or metal salts, antistatic agents, fungicides, fungicides, UV absorbers, and light, known as agricultural films. Stabilizers, colorants, stabilizers, antioxidants, inorganic fillers, antistatic agents, heat insulating agents, fungicides, algae-proofing agents and the like can be blended.

Examples of the plasticizer include phthalic acid derivatives such as gyn-octylphthalate, di-2-ethylhexylphthalate, dibenzylphthalate and diisodecylphthalate; isophthalic acid derivatives such as dioctylphthalate; gyn-butyl adipate, dioctyl adipate and the like. Adipic acid derivative; maleic acid derivative such as di-n-butylmalate; citric acid derivative such as trin-butylcitrate; itaconic acid derivative such as monobutylitaconate; oleic acid derivative such as butyloleate; glycerin monolithinolate And other ricinolic acid derivatives; other examples include epoxidized large oils and epoxy resin plasticizers. Further, in order to impart flexibility to the resin film, the resin film is not limited to the above-mentioned plasticizer, and for example, a thermoplastic polyurethane resin, polyvinyl acetate, or the like can be used.

As lubricants or heat stabilizers, fatty acid-based lubricants, fatty acid-amide-based lubricants, ester-based lubricants, polyethylene waxes, liquid paraffins, killer such as organic phosphite compounds, phenols, β, which are generally used for agricultural films. -Diketone compounds and the like can be mentioned.

Organic phosphates include triisopropylphenyl phosphate, isodecyldiphenyl phosphate, tris (isopropylphenyl) phosphate, tributyl phosphate, triethyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, octyldiphenyl phosphate, and trixylenyl. Phosphate and the like can be mentioned, but among them, tricresyl phosphate and trixylenyl phosphate are particularly preferable.

Examples of the antistatic agent include polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene alkyl ether, glycerin fatty acid ester, sorbitan fatty acid ester and the like.
Examples of the antifogging agent include nonionic surfactants, and specific examples thereof include sorbitan-based, glycerin-based, polyethylene glycol-based surfactants, and alkylphenol alkylene oxide adducts.
Examples of the anti-fog agent include fluorine-based surfactants and silicone-based surfactants.

Examples of the ultraviolet absorber include ultraviolet absorbers such as benzoate type, salicylic acid type, cyanoacrylate type, benzophenone type, benzotriazole type and triazine type (triaryltriazine type). Above all, it is desirable to use a benzophenone-based ultraviolet absorber or a benzotriazole-based ultraviolet absorber. One or two or more of these ultraviolet absorbers may be used in combination, and the amount used is 0.01 to 5 parts by weight, preferably 0.05 to 2 parts by weight, per 100 parts by weight of the thermoplastic resin.

Examples of the light stabilizer include 4-cyclohexinoyloxy-2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4- (o-chlorobenzoyloxy)-. Examples thereof include hindered amine compounds such as 2,2,6,6-tetramethylpiperidine.

Examples of the antioxidant include phenol-based, thiodipropionic acid ester, aliphatic sulfide and disulfide-based antioxidants, and specific examples thereof include 2,6-di-tert-butyl-4-methylphenol. , 2,2'-Methylenebis (6-tert-butyl-4-ethylphenol), dilaurylthiodipropionate and the like.

Examples of the inorganic filler include oxides such as calcium, magnesium and aluminum, hydroxides, carbonates, silicates and the like, and composites thereof.
Examples of the heat insulating agent include inorganic compound particles that absorb light rays in the far infrared region of 4000 nm to 25000 nm, and examples thereof include magnesium oxide, calcium oxide, aluminum oxide, silicon oxide, lithium hydroxide, magnesium hydroxide, and calcium hydroxide. Aluminum hydroxide, magnesium carbonate, calcium carbonate, calcium sulfate, magnesium sulfate, aluminum sulfate, lithium phosphate, calcium phosphate, magnesium silicate, calcium silicate, aluminum silicate, calcium aluminate, magnesium aluminate, sodium aluminosilicate, potassium aluminosilicate, Calcium alminosilicate, kaolin, clay, talc, mica, zeolite, hydrotalcite compounds, lithium-aluminum composite hydroxide, aluminum-lithium-magnesium composite carbonate compound, aluminum-lithium-magnesium composite silicate hydroxide, magnesium -Aluminum-silicon composite hydroxide, magnesium-aluminum-silicon composite sulfate compound, magnesium-aluminum-silicon composite carbonate compound, metal composite hydroxide salt containing multiple anions, and the like can be mentioned.

Anti-adhesive agents include at least one mixture selected from methylene bisstearoamide, ethylene bislauryl amide, N, N'-diorail adipamide, N, N'-distearyl adipamide. ..
Lubricants or heat stabilizers include fatty acid lubricants, fatty acid amide lubricants, ester lubricants, polyethylene waxes, liquid paraffins, killer such as organic phosphite compounds, phenols, β, which are generally used for agricultural films. − Examples include diketone compounds. As the β-diketone compound, dibenzoylmethane, methoxybenzoyl / benzoylmethane, chlorbenzoyl / benzoylmethane, palmitylbenzoylmethane and the like are suitable.

In the agricultural film of the present invention, in order to blend various additives, the required amount is weighed, and a blender such as a ribbon blender, a Banbury mixer, a Henschel mixer, a super mixer, a single-screw or twin-screw extruder, or a roll is used. A kneader or other conventionally known compounding machine or mixer may be used. In order to form the resin composition thus obtained into a film, a method known per se, for example, melt extrusion molding method (including T-die method and inflation method), calendar processing, roll processing, extrusion molding processing, etc. Methods such as blow molding, inflation molding, melt casting, pressure molding, paste processing, and powder molding can be preferably used.

The agricultural film thickness of the present invention is preferably in the range of 0.01 to 1 mm, more preferably 0.05 to 0.5 mm, and even more preferably 0.05 to 0. In terms of strength and cost. It is 2 mm. If it is less than this range, there is a problem in strength, and if it exceeds this range, molding is difficult and there is a problem in extension workability.
As the agricultural film of the present invention, a film in which an antifogging coating film is further applied to the inside during house expansion may be used. Further, a dust-proof coating film may be formed on the outer surface when the agricultural film is coated on the house.

Examples of the antifogging coating film include a composition containing a binder resin such as an inorganic colloidal sol and / or a thermoplastic resin as a main component. Preferably, an antifogging coating film containing an inorganic colloidal substance and a hydrophilic organic compound as main components or an antifogging coating film containing an inorganic colloidal substance and an acrylic resin as main components can be used. Further, the binder resin may not be added, and an inorganic substance such as colloidal silica or colloidal alumina may be laminated. The antifogging coating film that can be formed in the present invention is described in, for example, Japanese Patent Application Laid-Open No. 2008-067645.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded.

[Examples 1 to 7, Comparative Examples 1 to 4]
(1) Production of vinyl chloride-based resin film Polyvinyl chloride (polymerization degree = 1300) 100 parts by weight Di-2-ethylhexyl phthalate 45 parts by weight Tricresyl phosphate 5 parts by weight Epoxy resin (trade name "EP-828") 1 .5 parts by weight Ba-Zn-based liquid stabilizer 1 part by weight barium stearate 0.2 parts by weight zinc stearate 0.4 parts by weight sorbitan monopalmitate 1.5 parts by weight β-diketone compound (dibenzoylmethane) 0.1 By weight benzotriazole-based ultraviolet absorber 0.04 parts by weight (trade name "TINUVIN-P")
Fluorine-based surfactant (trade name "Unidyne DS-401") 0.2 parts by weight

The resin raw materials and resin additives mentioned above were weighed, and a predetermined amount of particles having the characteristics shown in Table 1 was further added thereto. These were stirred and mixed with a super mixer for 10 minutes and then kneaded on a roll heated to 165 ° C. to produce a transparent vinyl chloride resin film having a thickness of 0.075 mm by an L-shaped calendar device. The refractive index of the base resin in the state where the particles shown in Comparative Example 1 are not added is 1.53. The amount of the fine particles added in Table 1 is an amount added with the total weight of the vinyl chloride resin film as 100 parts by weight.

(2) Evaluation of film The performance of the film was evaluated by the following method, and the results are shown in Table 1.
(I) Optical characteristics The films prepared in Examples and Comparative Examples were measured for haze with a haze meter TC-HIIIDPK / II manufactured by Tokyo Denshoku Co., Ltd.
The evaluation criteria are as follows.
Straight light transmittance ◎… Haze is less than 2.0%.
○… Haze is 2.0% or more and less than 4.0%.
Δ: Haze of 4.0% or more and less than 10.0%.
×… Haze is 10.0% or more.

(Ii) Workability Tensile properties: The films obtained in Examples and Comparative Examples were evaluated by a method according to JIS K-6732 Annex Stickiness Test Method. The width of the material piece was 3 cm, the load cell capacity was 1 kg, the test speed (peeling speed) was 100 mm per minute, and the chart speed was 50 mm per minute.
The evaluation criteria are as follows.
Workability ◎… Peeling force is less than 40gf / 3cm.
◯: The peeling force is 40 gf / 3 cm or more and less than 50 gf / 3 cm.
Δ: A peeling force of 50 gf / 3 cm or more.

From the results of Examples and Comparative Examples, it can be said that the agricultural resin film in the present invention has good workability during ventilation work while maintaining high transparency.

Claims (5)

An agricultural resin film containing transparent fine particles and a base resin, wherein the difference between the refractive index of the transparent fine particles and the refractive index of the base resin is 0.02 or less. the film. The agricultural resin film according to claim 1, wherein the difference between the refractive index of the transparent fine particles and the refractive index of the base resin is 0.01 or less. Claim 1 in which 0.2 parts by weight to 1.0 part by weight of transparent fine particles are contained with respect to 100 parts by weight of the thermoplastic resin constituting the base resin, and the average particle size of the transparent fine particles is 200 nm or more and 30 μm or less. Or the agricultural resin film according to 2. The agricultural resin film according to any one of claims 1 to 3, wherein the transparent fine particles are organic fine particles containing an acrylic resin as a main component. The agricultural resin film according to any one of claims 1 to 4, wherein the thermoplastic resin constituting the base resin is a vinyl chloride resin.