JPH04153248A - Production of agricultural vinyl chloride film - Google Patents

Abstract

PURPOSE:To obtain an agricultural vinyl chloride film excellent in both antifogging and anticlouding properties by mixing a vinyl chloride resin with a specified fluorine compound and a sorbitan fatty acid ester in a specified ratio and forming the obtained mixture into a film. CONSTITUTION:A fluorine compound (A) of the formula (wherein R is 1-22C alkyl, alkenyl, nonylphenyl, octylphenyl or dinonylphenyl; R1 and R2 are each H or methyl; m and n are each 1 or greater; m+n=2-30; and Rf is 4-12C perfluoroalkyl) and a sorbitan fatty acid ester (B) prepared by reacting 1mol of sorbitol with 1-1.5mol of a 12-18C higher fatty acid (e.g. stearic acid) are prepared. A vinyl chloride resin is mixed with 1-5wt.% mixture of component A with component B in an A to B weight ratio of 20:80-5:95, and the obtained mixture is formed into an agricultural vinyl chloride film.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an agricultural film used for growing agricultural crops out of season. Specifically, the present invention relates to an agricultural film that does not generate fog in an agricultural greenhouse and exhibits excellent antifogging properties over a long period of time.

[Conventional technology]

In recent years, crop cultivation has been widely practiced in agricultural greenhouses, tunnels, etc. using synthetic resin films for the purpose of early or out-of-season cultivation of crops.

These synthetic resin films include polyethylene films and polyvinyl chloride films, and polyvinyl chloride films are mainly used.

However, since these synthetic resin films have a hydrophobic film surface, if they are used as is, water vapor evaporated from the ground surface or crop bodies in agricultural greenhouses or tunnels will only condense on the film surface and adhere as water droplets. Significant clouding of the film surface without showing any wetting phenomenon.

As a result, the penetration of sunlight becomes poor and the rate of temperature rise inside the heat insulation greenhouse decreases, significantly inhibiting the growth of crops.

To solve these problems, antifogging agents containing surfactants as a main component are added to agricultural films currently in use.

Agricultural films to which such antifogging agents have been added have a hydrophilic surface, and attached water droplets exhibit a wetting phenomenon, immediately expanding onto the film surface and flowing down, keeping the film surface transparent. It can be done.

However, agricultural greenhouses to which the above-mentioned antifogging agent has been added have good sunlight penetration and an excellent temperature-raising effect, but have the disadvantage that fog tends to form inside the greenhouse. When fog occurs inside a greenhouse, it wets the leaves, flowers, stems, etc. of cultivated crops, causing diseases such as gray mold and vine blight, resulting in a reduction in crop yield. The outlook is extremely poor, resulting in disadvantages such as reduced work efficiency.

This fog formation phenomenon is often observed from late autumn to winter when the outside temperature is low in the morning and evening.

The direct cause of such fog generation inside an agricultural greenhouse is that the water vapor inside the greenhouse reaches a saturated vapor pressure or higher due to the temperature difference between the inside and outside of the greenhouse. In other words, early fog is
Water vapor that evaporates from the ground surface inside the greenhouse comes into contact with the cold air above the greenhouse and condenses, turning into water droplets and becoming fog. Evening fog is caused by nearly saturated water vapor inside the house condensing as the temperature above the house falls, turning into water droplets and becoming fog. Furthermore, the amount of fog and factors that promote fog generation will be considered.6 One of them is the presence of condensation tubes within the greenhouse.

It is surmised that the water vapor rising from the ground surface of the greenhouse is promoted to condense (formation of fog) using dust etc. inside the greenhouse as a nucleus. This varies depending on the location and environment of the house. It is also thought that the degree of hydrophilicity of the ground surface of the greenhouse has an influence. That is, it is considered that the following three phenomena are constantly occurring on the film surface.

One is the flow of condensed water on the film surface due to collision of water vapor evaporated from the ground surface of the greenhouse and from the crop body, one is the rebound of the collided water vapor into the inside of the greenhouse, and one is the flow of water condensed on the film surface due to the collision of water vapor evaporated from the ground surface of the greenhouse and from the crop body. This is an phenomenon of re-evaporation of water flowing down into the house.

The balance between these phenomena is thought to be related to the degree of hydrophilicity of the film surface, which is presumed to be an important factor in determining the amount of fog generated.

Conventionally, various measures have been taken to suppress the formation of fog, such as reducing the temperature difference between the inside and outside of the house through ventilation, increasing the saturated water vapor pressure by heating the house, and using colored films. However, neither method was sufficient.

Also, the method of adding an organic siloxane surfactant described in JP-A No. 55-91663,
Methods such as adding a certain type of fluorine-based surfactant described in Publication No. 14648 have been proposed, but none of them completely suppresses the generation of fog, and even if they have a fog prevention effect, it is There still remain drawbacks such as a reduction in the long-term antifogging effect that is basically required for commercial films.

[Problem to be solved by the invention] The present inventors have solved the above-mentioned problem by preventing the generation of fog in an agricultural greenhouse (
The present invention was achieved as a result of intensive research aimed at producing an agricultural film that exhibits excellent anti-fog properties over a long period of time.

[Means for Solving the Problems] The present invention combines a fluorine compound represented by the following general formula [, I] and a sorbitan fatty acid ester [I[] into (1]:(1)
1) A method for producing agricultural vinyl chloride film with excellent anti-fog and anti-fogging properties, characterized by adding 1 to 5% by weight of vinyl chloride resin at a weight ratio of 20:80 to 5:95. It is related to.

General formula El) [However, R is an alkyl group having 1 to 22 carbon atoms, an alkenyl group, a nonylphenyl group, an octylphenyl group, or a dinonylphenyl group, and Ro and R□ are a hydrogen atom or methyl (where R, R.

Both are methyl groups), m and n are integers of 1 or more, and m0n is an integer of 2 to 30, and Rf has 4 to 4 carbon atoms.
12 perfluoroalkyl groups are shown. ] Sorbitan fatty acid ester [II] is obtained by reacting 1 mole of sorbitol with 1 to 1.5 moles of a higher fatty acid having 12 to 18 carbon atoms.

The present invention will be explained in detail below.

Vinyl chloride resins used in the present invention include geothermal vinyl of vinyl chloride homopolymer, vinyl acetate and its esters, acrylic acid and its esters, methacrylic acid and its esters, ethylene, propylene, vinylidene chloride, maleic acid, and fumaric acid. Copolymers such as acids are included, and vinyl chloride resin is preferred among them.

The fluorine compound represented by the general formula [I] used in the present invention includes 1 mol of perfluoroalkylethanol, an alcohol having 1 to 22 carbon atoms, nonylphenol, octylphenol, or dinonylphenol, and ethylene oxide alone or ethylene oxide and propylene. It is obtained by a ring-opening reaction with 1 mol of a compound represented by the following general formula (m), which has been added with an oxide and then converted into a glycidyl ether at the terminal end.

General formula [III] [However, R is an alkyl group having 1 to 22 carbon atoms, an alkenyl group, a nonylphenyl group, an octylphenyl group, or a dinonylphenyl group, and R1 and R8 are a hydrogen atom or a methyl group (however, R3 and R8 are both methyl group), m and n are integers greater than or equal to 1, and m+n=
An integer of 2 to 30, Rf represents a perfluoroalkyl group having 4 to 12 carbon atoms. ] In the general formula [1), Rf may be a perfluoroalkyl group having 4 to 12 carbon atoms, and a perfluoroalkyl group having 6 to 8 carbon atoms is particularly preferable from the viewpoint of fog-proofing properties.

In addition, in the compound represented by the general formula [II[], the number of moles of alkylene oxide added to alcohol having 1 to 22 carbon atoms, nonylphenol, octylphenol, or dinonylphenol is in the range of 2 to 30 moles, but methanol, In the case of alcohols with carbon atoms of 8 or less, such as ethanol and butanol, ■ 5 to 10 moles when adding ethylene oxide alone, ■ 5 to 15 moles of ethylene oxide, and propylene oxide when adding ethylene oxide and propylene oxide. 1~
A range of 3 moles is effective in terms of fog prevention properties.

In addition, decyl alcohol, dodecyl alcohol, stearyl alcohol, behenyl alcohol, etc. have 10 to 2 carbon atoms.
In the case of 2 higher alcohols or nonylphenol, octylphenol, dinonylphenol, etc., ■ 10 to 20 moles when adding ethylene oxide alone, ■ 12 to 22 moles of ethylene oxide, and propylene oxide when adding ethylene oxide and propylene oxide. Preferable results are obtained when the amount is in the range of 3 to 6 moles.

Incidentally, whether the method of adding ethylene oxide and propylene oxide is block or random, the effect remains the same.

In addition, sorbitan fatty acid ester [I
II] is obtained by reacting 1 mole of sorbitol with 1 to 1.5 moles of a higher fatty acid having 16 to 18 carbon atoms,
Valmitic acid is a higher fatty acid having 16 to 18 carbon atoms;
Stearic acid is preferred for its effectiveness. The number of moles of higher fatty acid reacted with respect to 1 mole of sorbitol is in the range of 1 to 1.5 moles, and if it exceeds 1.5 moles, the antifogging property becomes poor, which is not preferable.

In the present invention, when the compound represented by the general formula (11) and the sorbitan fatty acid ester (n) according to the present invention are each added alone to a vinyl chloride resin, the compound of the general formula [1] has anti-fog properties. , does not exhibit any antifogging effect, and sorbitan fatty acid ester [IIl] exhibits an antifogging effect but has no antifogging property, so it cannot be put to practical use.However, the compound of general formula [I] By using a specific sorbitan fatty acid ester [U] together in a specific ratio, an agricultural film that exhibits the excellent anti-fog and anti-fogging properties that are the gist of the present invention can be produced.

The reason why the combination of the compound of general formula [I] and the specific sorbitan fatty acid ester [II] exhibits excellent fog-proofing and anti-fogging properties useful as an agricultural film is not yet clear. It can be considered as a combined effect by using both together.

In addition, the total amount of the compound of general formula [I] and sorbitan fatty acid ester [n] added to the vinyl chloride resin is 1
The content is preferably 5% by weight, and adding more than 5% by weight does not improve performance much and is economically disadvantageous.

As is well known, the agricultural film of the present invention is made of soft vinyl chloride, and is usually made of 30 parts by weight per 100 parts by weight of vinyl chloride resin.
~70 parts by weight of a plasticizer is used as appropriate, and stabilizers, lubricants, ultraviolet absorbers, antioxidants, colorants, etc. are also used as necessary.

Thus, the vinyl chloride resin composition containing the above components is formed into a film by a known method such as a calendar method or a melt extrusion method.

[Examples] Next, the present invention will be explained by examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

100 parts by weight of lost Goso engineered vinyl chloride resin (degree of polymerization 1100), 45 parts by weight of dioctyl phthalate, 2 parts by weight of epoxidized soybean oil, 5 parts by weight of tricresyl phosphate, 1 part by weight of Ba-Zn metal soap, methylene Distearylamide 0.
5 parts by weight and 2 parts by weight of composition A of the invention Composition A of the invention: C,,H,5O(C,H9O),CHlCHCH,-C
,H,-C,F,.

H (adding 8 mol of ethylene oxide to 1 mol of dodecyl alcohol, then converting this terminal into a glycidyl ether,
10 parts by weight of a fluorine compound obtained by reacting this compound with 1 mol of C, F, C, H, OH) and 90 parts by weight of sorbitan balmitic acid (1.2 mol) ester (II) were mixed and calendered. A 100 micron film was created using a roll.

An experimental greenhouse was created by stretching this film onto a frame assembled above an outdoor temperature-controlled aquarium.

Observation of fog generation and evaluation of antifogging properties were performed using the following methods.

Tests began in late October. The water temperature in the aquarium set up for the experiment was raised to 40°C in the morning and evening when the temperature was low.
The occurrence of fog inside the greenhouse was observed for about 2 hours. The aquarium was left alone except for the time when the fog was observed.

This observation was carried out periodically until March.

The degree of fog generation was expressed using the following criteria.

O: No fog was observed at all.

O: Slight occurrence of fog is observed.

△・・・・・・Fog is observed. X: Significant fog formation is observed.

At the same time as the observation of fog, the heat protection properties of the inner surface of the film placed in the experimental greenhouse were periodically observed for 10 months.

Antifogging properties were evaluated based on the following criteria.

◎・・・・・・Status where no water droplets are observed○・
・・Slight adhesion of water droplets △・・・・
Condition X in which water droplets are observed to adhere: State in which a considerable amount of water droplets adhere to It can be seen that the film containing A exhibits excellent anti-fog and anti-fog properties.

Examples 2 to Stream Side 10 Films containing Compositions B to J according to the present invention listed in Table 1 were prepared in the same manner as in Example 1 to obtain Examples 2 to IO ( The results are shown in Table 2).

Comparative Example 1 Comparative Example 1 was obtained by producing a film containing 0.5 parts by weight of Composition A in the same manner as in Example 1.

The fluorine compound according to the present invention [
1] and sorbitan fatty acid ester [11] was added to composition B'', which was outside the range of the present invention, to obtain Comparative Example 2.

Composition B' Fluorine compound of Example 2 [1] ......
2% by weight Sorbitan fatty acid ester of Example 2 [nl.
......98% by weight Ratio 3 to Ratio 5 A film was prepared by adding one set of parabolic N to the following composition other than the present invention in the same manner as in Example 1, and a comparative example was prepared. Example 3~
Comparative Example 6 was obtained.

In the composition: C0)(□O(C,H,O)□CH,CHCH,-C,
H4~C@FI? H・・・・・・・・・・・・・・・10 parts by weight Sorbitan stearic acid (1.1 mol) ester・・・・・・
90 parts by weight Composition L: 1 5 parts by weight Composition M: 20 parts by weight Sorbitan stearic acid (1, 3 moles) ester...
......80 parts by weight Composition N: C4H□OCC,H,O), CII, CHCH.

C, H4 C, F□.

H ・・・・・・・・・・・・・・・・・・ 10 parts by weight Table 2 shows the results of the comparative example.

[Effects of the Invention] As seen in the Examples and Comparative Examples in Table 2, the agricultural film of the present invention is superior by blending and using a specific fluorine compound and a specific sorbitan fatty acid ester in a specific ratio. This made it possible to create an agricultural film that has both anti-fog and anti-fog properties.

In other words, it is possible to completely prevent the formation of fog, which is often observed in greenhouses from late autumn to winter, and the above-mentioned adverse effects caused by fog formation are eliminated, and at the same time, the agricultural film of the present invention has excellent anti-fog properties for a long period of time. Therefore, it is very effective for facility cultivation such as out-of-season cultivation of crops.

Patent applicant: Toho Chemical Industry Co., Ltd.

Claims (1)

[Claims] (1) A fluorine compound represented by the following general formula [I], 1 mol of sorbitol, and 1 to 18 higher fatty acids having 12 to 18 carbon atoms
Sorbitan fatty acid ester [II] obtained by reacting 1.5 mol of [I]:[II]=20:80 to 5:9
1. A method for producing an agricultural film having excellent anti-fog and anti-fogging properties, characterized by adding 1 to 5% by weight of vinyl chloride resin at a weight ratio of 5 to 5%. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [However, R is an alkyl group having 1 to 22 carbon atoms, an alkenyl group, a nonylphenyl group, an octylphenyl group, or a dinonylphenyl group, and R_1 and R_2 are hydrogen Atom or methyl group (however, R_1 and R_2 are not both methyl groups), m and n are integers of 1 or more and m+n = an integer of 2 to 30, Rf represents a perfluoroalkyl group having 4 to 12 carbon atoms . ]