JPS6225145A - Polyvinyl chloride film for agricultural use - Google Patents

Abstract

PURPOSE:To provide a polyvinyl chloride film for agricultural use effective to suppress the generation of fog and prevent the drop of water-droplets, by adding specific amounts of an antifogging agent, a perfluoroacrylate and a plasticizer to a base resin. CONSTITUTION:100pts.(wt.) of a vinyl chloride resin is compounded with (A) 30-70pts. of a plasticizer (e.g. phthalic acid ester), (B) 1-3pts. of an anti-fogging agent (e.g. polyethylene glycol monostearate) and (C) 0.01-0.5pts., preferably 0.03-0.3pts. of a perfluoroacrylate, and the mixture is formed in the form of film.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to agricultural polyvinyl chloride films. More specifically, it relates to an agricultural polyvinyl chloride film that suppresses the generation of fog (also called mist) and is excellent in preventing water droplets from falling (hereinafter referred to as droplets).

[Conventional technology] Agricultural polyvinyl chloride film is weather resistant and transparent to light! It has excellent A rate and heat retention, and is widely used in agriculture and horticulture in the form of greenhouses, frames, tents, tunnels, gangs, shades, etc. In such a cultivation house or tunnel, etc., water vapor generated from the cultivated soil or crops is inside or near the inner surface of the film or sheet (hereinafter referred to as film, etc.), causing the greenhouse or tunnel (hereinafter referred to as house, etc.) to It is cooled by the colder air outside and adheres to the inner surface of the house etc. as water droplets, causing cloudiness and reducing the light transmittance of the film etc.
It absorbs infrared rays from sunlight, slowing down the rise in temperature inside greenhouses, etc., and has a negative impact on crop growth.

Conventional methods have been used to prevent water droplets from adhering to the inner surface of the film or the like of such houses. That is, in order to impart wood-philicity to the surface of a vinyl chloride resin film, etc., a film produced by adding an antifogging agent to a vinyl chloride resin is used to improve the wettability of the film with water droplets. , the water droplets adhering to the inner surface of the film, etc. are made to adhere to each other, the water droplets are developed into a film, and the water film is removed by dripping along the surface of the film, etc., to improve the translucency of the film, etc. Measures have been taken to prevent this decline.

Examples of the antifogging agents mentioned above include 7-ion surfactants such as alkyl sulfosuccinates, alkylnaphthalene sulfonates, alkylaryl sulfonates, and alkyl sulfates, and higher fatty acid esters such as polyethylene glycol, polyglycerol, sorbitan, and sorbitol. , polyoxyethylene alkyl ether.

Nonionic surfactants such as polyoxyethylene alkylamino ether, cationic surfactants such as alkyldimethylbenzylammonium salts, alkyltrimethylammonium salts, alkyloylimidazolinium ammonium salts, alkylamidopropyldimethylammonium salts,
Alternatively, there are amphoteric surfactants such as alkylamidopropyldimethylpentine, which are used by being added to vinyl chloride resins.

However, in cultivation plants using vinyl chloride resin films to which the above-mentioned antifogging agent is added, the problem of water droplets adhering to the greenhouse has been solved, but on the other hand, fog can form inside the greenhouse. It tends to be easy.

The above-mentioned fog that occurs in greenhouses, etc. for gardening tends to cause diseases such as gray mold and sclerotium to occur in the crops grown in the greenhouses, etc. As a result, the yield of crops is reduced and the quality of the crops is deteriorated. I will invite you.

In order to suppress the generation of such fog, attempts have been made to add an organic siloxane surfactant or a fluorine surfactant to the above-mentioned vinyl chloride resin.

However, although agricultural vinyl films obtained by molding polyvinyl chloride compositions containing these surfactants are effective in suppressing the generation of fog, they are highly wood-friendly and cannot be used as droplets. Water droplets attached to the inner surface of the house will no longer flow down along the film after long-term use.
This method has the disadvantage of causing water droplets to fall. The droplets cause the rotting of young crop buds and the occurrence of various diseases, and similar to the harmful effects of fog, they affect the yield range of crops.
This results in quality deterioration.

[Object of the Invention] The present inventors have conducted extensive research to solve the above-mentioned problems regarding agricultural polyvinyl chloride films.

As a result, a film made of a polyvinyl chloride resin composition containing an antifogging agent, perfluoroacrylate, and a plasticizer, which has been commonly used in the past, suppresses fog generation and reduces droplets when used as an agricultural film. The present invention was completed based on the discovery that the present invention has the following effects.

As is clear from the above description, an object of the present invention is to provide such a film and a method of using the same, in which the problems of the prior art are solved.

[Structure and effects of the invention] The present invention has the following configuration.

A resin composition containing 100 parts by weight of a vinyl chloride resin, 30 to 70 parts by weight of a plasticizer, 1.0 to 3.0 parts by weight of an antifog agent, and 0.01 to 0.5 parts by weight of a fluoride surface modifier. Agricultural polyvinyl chloride film consisting of.

Examples of vinyl chloride resins used in the invention include vinyl chloride homopolymers, copolymers of vinyl chloride with vinyl acetate, vinylidene chloride, ethylene, propylene, etc., or mixtures of two or more of these.

Further, examples of the plasticizer used in the present invention include phthalic acid esters, fatty acid esters, epoxidized fatty acid esters, phosphoric acid esters, polyglycol esters, and mixtures of two or more of these. The amount of the plasticizer added is preferably 30 to 70 parts by weight per 100 parts by weight of the vinyl chloride resin.

If the amount of plasticizer is less than 30 parts by weight, the resulting film will be too hard and unsuitable for use as an agricultural film, and the film may be torn, especially at low temperatures, which is undesirable.
Moreover, if the amount of plasticizer exceeds 70 parts by weight, the film obtained will be too soft, and the film will become sticky, particularly in summer, resulting in a decrease in workability and antifogging effect, which is undesirable.

As the antifogging agent used in the present invention, any antifogging agent that has been conventionally incorporated into agricultural coating films may be used. For example, polyethylene glycol alkyl esters such as polyethylene glycol monostearate and polyethylene glycol dibehenate, sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monooleate, and polyoxyethylenes such as polyoxyethylene lauryl ether. Examples include fatty acid ethers, glycerin fatty acid ethers such as glycerin behenyl ether, and fatty acid alkylolamine condensates such as jetanolamine stearate, and these may be used alone or in combination of two or more.

The amount of the antifogging agent added is in the range of 1.0 to 3.0 parts by weight per 100 parts by weight of the vinyl chloride resin. ) If the amount of the nuclear antifogging agent added is less than 1.0 parts by weight, the period during which water droplets can be prevented from adhering to the surface of the film when formed into a film is short; If the amount exceeds 100%, it becomes difficult to uniformly disperse the resin in the vinyl chloride resin, and the transparency and mechanical strength of the resulting film decreases, which is undesirable and uneconomical.

Furthermore, the amount of perfluoroacrylate used in the present invention is 0 parts by weight per 100 parts by weight of vinyl chloride resin.
．． 01 to 0.5 parts by weight, preferably 0.03 to 0.3 parts by weight. If the amount added is less than 0.01 part by weight, there is no effect of preventing fog generation, and if it exceeds 0.5 part by weight, the thermal stability and weather resistance of the resulting film will decrease, which is not preferable.

Furthermore, in the resin composition for agricultural polyvinyl chloride film according to the present invention, various additives can be used as in general resin compositions for film production. Stabilizers such as stabilizers and organotin stabilizers can be used alone or in combination of two or more. Furthermore, antioxidants, ultraviolet absorbers, organic chelator-1 pigments, lubricants, bactericidal agents, etc. can also be used.

The agricultural polyvinyl chloride film of the present invention can be produced as follows. That is, vinyl chloride resin, a certain amount of plasticizer, and various stabilizers.

Silicone oil and fluorine-based surfactants are applied using conventional equipment such as the Hensel mixer (trade name).

After stirring and mixing with a super mixer etc., use a calender roll at a roll temperature of 160 to 200℃, preferably 18
It is obtained by melt-kneading and forming a film at 0°C.

The polyvinyl chloride film of the present invention thus obtained is
When the film was spread on a greenhouse, etc., it was found that no fog was generated inside the greenhouse, and the film was found to be excellent in preventing lint from falling off, confirming the remarkable effects of the present invention.

The present invention will be explained below with reference to Examples and Comparative Examples. In addition, the following method was used to evaluate the occurrence of fog and the falling of slag in the Examples and Comparative Examples.

(1) Evaluation of true occurrence In the greenhouse where the agricultural polyvinyl chloride film produced in the Examples and Comparative Examples was spread, 2:00 am and 5:00 pm
The concentration of the fog was evaluated based on the visibility of a sign with a black circle with a diameter of 5 cm on a white background 10 m ahead according to the following criteria.

5: No occurrence of %i.

4: ji occurs faintly, but the sign is clearly visible.

3: There is fog, and the signs look blurry.

2: s occurs considerably, the sign is faintly visible 61: N occurs severely, the sign cannot be seen.

(2) Three months after spreading the drop-off film, the state of water droplet adhesion on the inner surface of the film at the bottom part was observed and evaluated according to the following criteria.

5: No water droplets attached 4: Slight water droplets attached Water droplets attached to some parts of 3D 2: Considerable amount of water droplets attached l: Water droplets attached all over the surface Examples 1-6. Comparative examples 1 to 4 Ioom i part of polyvinyl chloride with an average degree of polymerization of 1300.

Dioctyl phthalate (DOP) 45 parts by weight, tricresyl phosphate 5 parts by weight, epoxy resin type 2 part,
1.5 parts by weight of Ba-Zn-based liquid composite stabilizer, Ba
-1 part by weight of Zn-based metal soap, 0.
After mixing 2 parts by weight of the sorbitan antifogging agent, 2 parts by weight of the sorbitan antifogging agent, and the parts of each additive shown in Table 1 using a Hensel mixer (trade name), the mixture was melt-kneaded using a 28-inch inverted calendar roll. A film with a thickness of 0.1 mm was molded at 180°C.

In addition, as Comparative Examples 1 to 4, 100 parts by weight of the same polyvinyl as in Examples 1 to 6, 45 parts by weight of DOP, 5 parts by weight of tricresyl phosphate, 2 parts by weight of epoxy resin,
1.5 parts by weight of 13a-Zn-based liquid composite stabilizer.

1 part by weight of Ba-Zn metal soap, 0.2 parts by weight of methylene bisamide, 2 parts by weight of sorbitan antifogging agent, and the number of parts of additives shown in Table 1 were mixed in the same manner as in Examples 1 to 6. A film having a thickness of 0.1 mm was obtained by molding in the same manner as in 1 to 6.

The film thus obtained was spread in a semi-cylindrical house with a width of 5 m, a height of 2 m, and a length of 10 m, and the presence or absence and degree of fog generation in the house, as well as the amount of dripping, were observed and evaluated.

These results are summarized in Table 1.

Claims (1)

[Claims] Agriculture consisting of a resin composition containing 100 parts by weight of a vinyl chloride resin, 30 to 70 parts by weight of a plasticizer, 1.0 to 3.0 parts by weight of an antifog agent, and 0.01 to 0.5 parts by weight of perfluoroacrylate. PVC film for use.