JPH11346574A - Antifogging cover film for farming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover film for farming that manifests good antifogging properties, when it is used, and can suppress the occurrence of hazardous gases on its incineration disposal. SOLUTION: This anti-fogging covering film is obtained formulating (A) a fluorine-containing surfactant, (B) a nonionic surfactant other than the fluorine- containing surfactant, (C) an inorganic powder containing alkali metals and/or alkaline earth metals as constituent elements and (D) iron oxide particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-fog agricultural coating film, and more particularly, to an anti-fog agricultural film which is less likely to generate toxic gas due to a fluorine-based surfactant when incinerated after use. The present invention relates to an agricultural covering film.

[0002]

2. Description of the Related Art In recent years, forcing cultivation of various vegetables and fruits in a greenhouse using a coated film made of synthetic resin, or
Suppression cultivation is being carried out. And with this cultivation technique,
Various agricultural products can be distributed throughout the four seasons. One of the problems that has conventionally been encountered in greenhouse and tunnel cultivation using a synthetic resin-coated film is a fog generation phenomenon. This is because fog is generated in the morning and evening when the temperature difference between the inside and outside of the coating material increases inside a house or tunnel coated with a synthetic resin coating material containing an antifogging agent. This phenomenon often appears particularly in winter. The fog generated inside the houses and tunnels wets the cultivated crops, causing disease and reducing the yield and quality of the crops.

Under such circumstances, Japanese Patent Application No. 55-87249 proposes a synthetic resin film for coating having a function of suppressing generation of fog, and has been put to practical use. This is to mix a synthetic resin with a fluorine-based surfactant as an anti-fog agent and a non-ionic surfactant other than the fluorine-based surfactant as an anti-fog agent. Although many other proposals have been made, the use of a fluorine-based surfactant as an antifog agent has become mainstream.

As described above, a synthetic resin film for coating using a fluorine-based surfactant has a function of greatly reducing the generation of fog in a house or a tunnel. Not only is there a problem that toxic fluorine-based gas is generated due to a fluorine-based surfactant such as hydrogen hydride, but also there is a concern that dioxins are generated due to incomplete combustion. This tendency was feared as a more serious problem when a vinyl chloride resin was used as the synthetic resin.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances. In other words, it provides a good fog generation suppression function when used, and provides an agricultural coating film that generates less toxic gas and has less danger of generating dioxins even when incineration is used at the time of disposal. The purpose is to do.

[0006]

Means for Solving the Problems The present inventors have made intensive studies. As a result, the present inventors have found that the above-mentioned problems can be solved by further blending a specific inorganic powder and a specific iron-containing component with a conventional formulation of a mist-proof agricultural covering film, and have accomplished the present invention. That is, according to the present invention, (A) a fluorine-based surfactant, (B) a nonionic surfactant other than a fluorine-based surfactant, (C) an alkali metal, and / or an alkali The present invention provides a mist-proof agricultural coating film characterized by comprising an inorganic powder containing an earth metal as a constituent element and (D) iron oxide particles. Further, the thermoplastic synthetic resin comprises (A) a fluorine-based surfactant, (B) a nonionic surfactant other than the fluorine-based surfactant, (C) an alkali metal, and / or an alkaline earth metal. Inorganic powder containing as element, (D)
A multilayer film comprising iron oxide particles,
Of the layers constituting the multilayer film, the layer located on the crop side during use is (A) a fluorine-based surfactant,
(B) A fog-proof agricultural coating film characterized by containing at least a nonionic surfactant other than a fluorine-based surfactant. Still more preferably, any one of the above fog-proof agricultural covering films is provided, wherein the thermoplastic synthetic resin is selected from polyolefin-based synthetic resins.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. As the thermoplastic synthetic resin used in the present invention, those generally used as agricultural coating films can be used. For example, vinyl chloride resins represented by vinyl chloride; polyethylene, polypropylene, ethylene-
Polyolefin resins represented by acetic acid copolymers; polyesters, polyamides, and the like can be used, and these can be used in combination of two or more as long as they have good compatibility. Among these, a polyolefin resin containing no halogen and having good moldability is most preferable.

In the present invention, the fluorine-based surfactant used as an antifog agent includes polyethylene glycol-perfluoroalkylesteramide, perfluoroalkylsulfonate, perfluoroalkylcarboxylate, and perfluoroalkyltrimethylammonium. Salts, perfluoroalkyl phosphates, and the like. Further, a reaction product of a polyoxyalkylene polyol or a polyoxyalkylene polyamine in which a hydroxyl group terminal of the polyoxyalkylene polyol is substituted with an amino group and a reactive polyfluoro compound as disclosed in Japanese Patent No. 2637736. There may be. The amount of the fluorinated surfactant to be used is preferably 0.01 to 3 parts by weight, more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the thermoplastic synthetic resin.
02 to 1 part by weight. If the amount is less than 0.01 part by weight, sufficient anti-fog properties cannot be obtained, and if the amount exceeds 3 parts by weight, the appearance of the film, particularly the transparency, becomes poor.

On the other hand, nonionic surfactants other than the fluorine surfactant used as the antifogging agent in the present invention include, for example, sorbitan monostearate, sorbitan monopalmitate, sorbitan monooleate, sorbitan monooleate Sorbitan-based surfactants such as acrylates, glycerin-based surfactants such as glycerin monolaurate, diglycerin monopalmitate and glycerin monostearate, and polyethylene glycol-based surfactants such as polyethylene glycol monostearate and polyethylene glycol monopalmitate Agents, trimethylolpropane surfactants such as trimethylolpropane monostearate, pentaerythritol surfactants such as pentaerythritol monopalmitate, and ethylene oxide Obtained by adding propylene oxide, and the like. Of these, sorbitan ester surfactants, glycerin ester surfactants, and the like are preferable. The compounding amount of the antifogging agent is 100% of thermoplastic synthetic resin.
It is 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on parts by weight. If the amount is less than 0.05 part by weight, a good antifogging effect does not appear, which is not preferable. On the other hand, if the amount exceeds 5 parts by weight, the film becomes sticky and dust tends to adhere, which is not preferable. .

On the other hand, the inorganic powder used in the present invention containing an alkali metal and / or an alkaline earth metal as a constituent element includes hydrotalcite, talc, kaolin, calcium carbonate, magnesium oxide, potassium titanate, clay And the like. These inorganic powders act as a supply source of components for generating halogens and salts such as fluorine, impart an anti-blocking property to the film, and improve nighttime heat retention by an infrared absorption effect. It is used for the purpose. The compounding amount of the inorganic powder is appropriately determined depending on whether the thermoplastic synthetic resin contains a halogen, in addition to the compounding amount of the fluorine-based surfactant, but when a resin containing no halogen is used as the thermoplastic synthetic resin. Is 0.1 parts by weight with respect to 100 parts by weight of the thermoplastic synthetic resin.
Generally, it is used in an amount of 10 to 10 parts by weight, more preferably 0.5 to 5 parts by weight.

[0011] As the iron oxide particles used in the present invention, hydrous ferric oxide, ferric oxide, ferric oxide, ferrous oxide and the like can be used without particular limitation. Is preferred in terms of price and effect. In the present invention, the iron oxide particles exhibit a unique auxiliary combustion effect and a halogen fixing effect. The mechanism of these effects is not clear, but it is presumed that the following reactions occur. Regarding the combustion-assisting effect Iron atoms on the surfaces of the ferric hydroxide particles and the iron oxide particles are stabilized by surface hydroxyl groups formed by dissociation and adsorption of water. Unsaturated iron and oxygen ions are formed. Next, the coordinatively unsaturated active sites generated in this manner exhibit catalytic activity in a series of processes such as activation of oxygen by oxygen adsorption generated in the combustion process and dehydrogenation reaction from organic matter, and promote combustion. The effect is shown. About halogen fixation effect First, iron oxide particles are reduced in a reducing atmosphere at the beginning of combustion,
Then, the produced hydrogen halide reacts with the reduced iron oxide particles to produce an iron halide, which is further decomposed at a high temperature and in the presence of oxygen and water to cause the active halogenation. The hydrogen halide reacts with the inorganic powder containing the alkali metal and / or the alkaline earth metal as a constituent element, which becomes the original iron oxide and releases the hydrogen halide, thereby fixing the hydrogen halide. You. The amount of the iron oxide particles is 0.01 to 3 parts by weight, based on 100 parts by weight of the thermoplastic synthetic resin.
More preferably, it is 0.05 to 1 part by weight. If the amount of the iron oxide particles is less than 0.01 parts by weight, the object of the present invention cannot be sufficiently achieved. Conversely, if it exceeds 3 parts by weight, not only the effect corresponding to the compounding amount cannot be increased, but also the film tends to be colored.

In the present invention, in addition to the above-mentioned composition, known heat insulating agents such as silica, anti-blocking agents, lubricants, ultraviolet absorbers, light stabilizers, antioxidants, coloring agents and plasticizers are commonly used. It can be blended in an amount.

Further, the fog-proof agricultural covering film of the present invention is not limited to a single-layer structure, but is also applicable to a multi-layer structure. In this case, at the time of use, the layer (inner layer) located on the crop side contains at least (A) a fluorinated surfactant and (B) a nonionic surfactant other than the fluorinated surfactant. And the inner layer,
And / or (C) an alkali metal in a layer other than the inner layer,
And / or an inorganic powder containing an alkaline earth metal as a constituent element, and (D) iron oxide particles may be contained. Naturally, (A) the fluorinated surfactant and (B) the nonionic surfactant other than the fluorinated surfactant may be blended not only in the inner layer but also in other layers. When the mist-proof agricultural covering film of the present invention has a multilayer structure as described above, it is blended in each layer (A) to (D).
The total amount of each component may be within the above-mentioned range.

The composition described above constitutes the mist-proof agricultural covering film of the present invention. Known methods such as an inflation extrusion molding method, a T-die extrusion molding method, and a calendar molding method are used to produce the mist-proof agricultural covering film. Further, when the mist-proof agricultural covering film has a multilayer structure, an inflation type coextrusion method and a T-die type coextrusion method are used. Also, (A) a fluorine-based surfactant,
(B) a nonionic surfactant other than a fluorine-based surfactant, (C) an inorganic powder containing an alkali metal and / or an alkaline earth metal as a constituent element, and (D) iron oxide particles, respectively. Alternatively, it is preferable to melt-knead a plurality of kinds with a thermoplastic synthetic resin at a time to form a master batch, and further (C) an alkali metal, and / or
Alternatively, inorganic powder containing an alkaline earth metal as a constituent element, and (D) iron oxide particles may be surface-treated with a known dispersant such as a silane coupling agent or a titanate coupling agent.

[0015]

The present invention will be described in more detail with reference to the following examples. The measurement of the generation amount of the fluorine-based gas was performed according to the following procedure. <Fluorine gas generation amount analysis method> Combustion pyrohydrylosis method A film is burned in a steam stream under an oxidizing atmosphere.
The generated fluorine-based gas is absorbed in alkaline water, and the fluorine ion concentration is determined with a fluorine ion electrode. Then the ratio of the amount of detected fluorine to the weight of the original film: R
(Wt%) is calculated. It can be said that the smaller this value is, the less the fluorine-based gas generated from the film is.

The evaluation of the anti-fog performance was performed according to the following procedure. <Evaluation method for anti-fog performance> A test film was placed on the inclined surface of the fog observation frame surrounded by plywood on all sides, and placed on a water bath maintained at a water temperature of about 40 ° C.
Leave for 24 hours in a constant temperature room kept at 5 ° C. Next, the temperature of the constant temperature chamber is reduced to 5 ° C. without changing the temperature of the water bath. Then, the state of fog generation near the inner surface of the sample film is visually observed for about 2 hours.

Further, in the following Examples, Comparative Examples and Reference Examples, the following synthetic resins and additives were used. Synthetic resin 1: Linear low-density polyethylene (Sumikasen FZ-101, manufactured by Sumitomo Chemical Co., Ltd.): Abbreviated as LLDPE. -Synthetic resin 2: ethylene-vinyl acetate copolymer (Evatate H-2020, manufactured by Sumitomo Chemical Co., Ltd.) ... EVA
Abbreviated. -Fluorosurfactant: (Surflon KC-40 manufactured by Asahi Glass Co., Ltd., fluorine content: 33 wt%)-Nonionic surfactant other than fluorosurfactant (referred to as anti-fogging agent): diglycerin-fatty acid Ester-based iron oxide particles: hydrous ferric oxide particles (average particle size 0.5μ)
m) ・ Inorganic powder: Hydrotalcite (Kyowa Chemical Industry Co., Ltd., DHT-4A)

[Examples 1 and 2, Comparative Examples 1 to 3 and Reference Examples] A φ55 having a φ120 die was prepared so that the ratio of each component in the finally obtained film was as shown in Table 1.
Inflation molding by extruder, about 100μ thickness
m was obtained. The two types of surfactants, iron oxide particles, and inorganic powder were processed in advance into a masterbatch based on the synthetic resin used in each of Examples and Comparative Examples. Next, the obtained film was evaluated for fog resistance and the amount of fluorine-based gas generated from the film during combustion by the above-described method. The results are shown in Table 1.

[0019]

[Table 1]

As is clear from Table 1, the films of Examples 1 and 2 containing the components as disclosed in the present invention not only have good anti-fog properties, but also have a low R value. It is clear that the generation of fluorine-based gas during combustion is greatly reduced. On the other hand, in the compositions of Comparative Examples 1 to 3 not containing any of the iron oxide particles, or the inorganic powder containing the alkali metal and / or the alkaline earth metal as a constituent element, the value of R was high, It is clear that a large amount of fluorine-based gas is generated.

Example 3 A three-layer extruder (φ120) equipped with a φ120 three-layer die was prepared so that the proportion of each component in each layer constituting the finally obtained film was as shown in Table 2.
40 extruder × 3) to give a three-layer film having a thickness of about 100 μm and a thickness ratio of 1/2/1. The two types of surfactants, iron oxide particles, and inorganic powder were processed in advance into a masterbatch based on the synthetic resin used in each of Examples and Comparative Examples. Next, the obtained film was evaluated for fog resistance and the amount of fluorine-based gas generated from the film during combustion by the above-described method. As a result, the obtained film showed good anti-fog properties. And the value of R was 0.01 wt%.

[0022]

[Table 2]

Comparative Example 4 A film having a thickness of about 100 μm was prepared in the same manner as in Example 3 except that the proportion of each component in each layer constituting the finally obtained film was as shown in Table 3.
Thus, a three-layer film having a thickness composition ratio of 1/2/1 was obtained. Subsequently, the obtained film was evaluated for its anti-fog properties and the amount of generated fluorine-based gas. As a result, the obtained film showed good anti-fog properties. And the value of R was 0.06 wt%.

[0024]

[Table 3]

As is evident from the comparison of the results of Example 3 and Comparative Example 4, the film containing the components as disclosed in the present invention not only has good anti-fog properties, but also has a multilayer structure. It is clear from the low value of R that the generation of fluorine-based gas during combustion is significantly reduced.

[0026]

As described above, according to the present invention, there is provided an anti-fog agricultural covering film which is excellent in preventing fog and reduces the amount of toxic gas generated even after incineration after use. Provided. In addition, it is considered that the effect of promoting the combustion of the iron oxide particles has a good effect on suppressing the generation of dioxins during incineration. Thus, it can be said that the fog-proof agricultural covering film provided by the present invention is useful from the viewpoint of global environmental protection.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 27/28 101 B32B 27/28 101 27/32 27/32 C C08J 5/18 CES C08J 5/18 CES

Claims (3)

[Claims] 1. A thermoplastic synthetic resin comprising (A) a fluorinated surfactant, (B) a nonionic surfactant other than a fluorinated surfactant, (C) an alkali metal, and / or an alkaline earth Inorganic powder containing metal as a constituent element, (D)
An anti-fog agricultural coating film comprising iron oxide particles. 2. A thermoplastic synthetic resin comprising: (A) a fluorine-based surfactant, (B) a nonionic surfactant other than a fluorine-based surfactant, (C) an alkali metal, and / or an alkaline earth Inorganic powder containing metal as a constituent element, (D)
A multilayer film containing iron oxide particles, wherein, among the layers constituting the multilayer film, the layer located on the crop side during use is (A) a fluorinated surfactant, (B)
A fog-proof agricultural covering film comprising at least a nonionic surfactant other than a fluorine-based surfactant. 3. The mist-proof agricultural covering film according to claim 1, wherein the thermoplastic synthetic resin is selected from a polyolefin-based synthetic resin.