JPH01198652A - Production of film for agricultural use - Google Patents

Abstract

PURPOSE:To obtain an agricultural film having excellent anticlouding and antifogging property and suitable for horticulture under structure house for e.g. season-off culture of crops, by compounding a specific fluorine compound and a specific sorbitan fatty acid ester at specific ratios. CONSTITUTION:A vinyl chloride resin is compounded with (A) a fluorine compound of formula I [A is polyhydric alcohol residue; R1 and R2 are H or methyl (R1 and R2 are not H at the same time); m and n are integers of >=1; m+n is 2-20; x is number of OH groups of the polyhydric alcohol; l is 1-(x-l); B is group of formula II (Rf is 4-10C perfluoroalkyl)] and (B) a sorbitan fatty acid ester produced by reacting 1mol. of sorbitol with 1-1.5mol. of a 16-18C higher fatty acid at a weight ratio (A:B) of 50:50-10:90. The amount of A+B is 1-5wt.% based on the vinyl chloride resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an agricultural film used for out-of-season growth of agricultural crops.

More 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 in agricultural greenhouses or tunnels, or from the crops will condense on the film surface and adhere as water droplets.
This results in a significant clouding of the film surface without exhibiting any so-called wetting phenomenon.

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

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

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

However, agricultural greenhouses with the above-mentioned anti-fogging agent added.

It has good penetration of sunlight and has an excellent temperature-raising effect.”
The disadvantage is that fog tends to form inside the house. 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 inside visibility 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 fog formation in 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 morning fog occurs when water vapor that evaporates from the ground surface inside the greenhouse comes into contact with the cold air above the greenhouse and condenses into water droplets, forming fog. Further, 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.

One reason is the presence of condensation nuclei within the house. It is surmised that the water vapor rising from the ground surface of the greenhouse is accelerated 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 film surface within the greenhouse has an influence. That is, it is considered that the following three phenomena are constantly occurring on the film surface.

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

The degree of hydrophilicity of the film surface is considered to be largely involved in how these phenomena are balanced, and is estimated to be an important factor determining the amount of fog generation.

Conventionally, various methods have been used to suppress the formation of fog, such as reducing the temperature difference between the inside and outside of the house through ventilation, raising the saturated water vapor pressure by heating the house, and using colored films. Various measures have been taken, but none of them have been 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 However, there are still drawbacks such as a reduction in the long-term antifogging effect that is basically required for commercial films.

[Problem that the invention seeks to solve]

As a result of our earnest efforts, the present inventors aimed to produce an agricultural film that prevents the formation of fog in agricultural greenhouses (fog-proofing properties) and exhibits excellent anti-fogging properties over a long period of time. This has led to the present invention.

[Means for solving problems]

The present invention combines a fluorine compound represented by the following formula [I] and a sorbitan fatty acid ester [11] into (1):
] = 50:50 to 10:90 weight ratio to vinyl chloride resin in a weight ratio of 1 to 5% by weight, which relates to a method for producing an agricultural film with excellent antifogging and fogging properties. It is.

-Formula [I]: R,R.

[However, A is a polyhydric alcohol residue, R3 and R8 are hydrogen atoms or methyl groups (however, both R8 and R1 are not methyl groups), m and n are integers of 1 or more, and m + n = An integer of 2 to 20, χ is the number of OH groups in the polyhydric alcohol, Q is an integer of 1 to (χ-first t), B is OH (however, Rf is a perfluoroalkyl group having 4 to 10 carbon atoms) ] The following is a detailed explanation of the present invention.

The vinyl chloride resin used in the present invention includes geothermal vinyl of vinyl chloride homopolymer, vinyl acetate and its ester, acrylic acid and its ester, methacrylic acid and its ester, ethylene, propylene, vinylidene chloride, maleic acid, Contains copolymers such as fumaric acid,
Among them, vinyl chloride resin is preferred.

The fluorine compound represented by formula (1) used in the present invention is an ether compound obtained by adding ethylene oxide to a polyhydric alcohol, or an ether compound obtained by adding ethylene oxide and propylene oxide to a polyhydric alcohol. It is obtained by subjecting an ether compound obtained by subjecting an α-olefin oxide having the following structure (R represents a perfluoroalkyl group having 4 to 10 carbon atoms) to a ring-opening addition reaction.

Polyhydric alcohols include glycerin, diglycerin,
Among sorbitol, sorbitan, and pentaerythritol, it is particularly preferable to use glycerin and sorbitol from the viewpoint of antifogging and antifogging properties, which are the gist of the present invention.

In addition, the number of moles of alkylene oxide added to polyhydric alcohol is on average in the range of 2 to 20 moles per ○H group of polyhydric alcohol, but when only ethylene oxide is added, 2 to 20 moles are added to polyhydric alcohol. A range of 5 moles is effective in terms of fog prevention properties, and when ethylene oxide and propylene oxide are added, ethylene oxide is added in a range of 5 to 15 moles, and propylene oxide is added in a range of 1 to 5 moles. give favorable results.

The method of adding ethylene oxide and propylene oxide is the same in terms of effectiveness, whether block or random.

If the average number of moles of alkylene oxide added to one OH group of the polyhydric alcohol exceeds 20 moles,
In particular, the antifogging durability becomes poor, which is not preferable, and if the number of moles of alkylene oxide added is less than 2 moles, both the fogproofing property and the antifogging property become poor.

The above-obtained alkylene oxide adduct of polyhydric alcohol (hereinafter referred to as polyoxyalkylene polyhydric alcohol ether) is reacted with the above-mentioned α-olefin oxide to obtain the compound of formula [I] according to the present invention. However, the reaction of α-olefin oxide with polyoxyalkylene polyhydric alcohol ether is such that 1 mol or more of α-olefin oxide is used per 1 mol of polyoxyalkylene polyhydric alcohol ether, and one OH group of the polyoxyalkylene polyhydric alcohol ether is used. It is preferable to carry out the reaction within the above range.

More preferably, in the case of polyoxyalkylene polyhydric alcohol ether derived from glycerin, α-
In the case of polyoxyalkylene polyhydric alcohol ethers derived from diglycerin, sorbitan, and pentaerythritol, α-olefin oxide is added per 1 mol of polyoxyalkylene polyhydric alcohol ether. in the range of 2 to 3 moles, and in the case of polyoxyalkylene polyhydric alcohol ether derived from sorbitol, α-
It is effective to react the olefin oxide in a range of 2 to 4 moles.

In addition, sorbitan fatty acid ester used in the present invention [
[Il is obtained by dehydrating 1 mole of sorbitol and 1 to 1.5 moles of higher fatty acids having 16 to 18 carbon atoms in a conventional manner, and the higher fatty acids having 16 to 18 carbon atoms include palmitic acid, , stearic acid is preferable in terms of effectiveness.9 The number of moles of higher fatty acid per mole of sorbitol is 1 to 1.
The amount is in the range of 1.5 mol, and if it exceeds 1.5 mol, the antifogging property will be poor, which is not preferable.

In the present invention, when the compound represented by formula [+1] and sorbitan fatty acid ester [11] according to the present invention are each added alone to a vinyl chloride resin, -
The compound of formula (11) exhibits no effect at all in both anti-fog and anti-fog properties, and the compound of formula (Ill.
Although it exhibits an anti-fog effect, it does not have anti-fog properties and cannot be put to practical use.

However, by using a compound of the formula (Il) and a specific sorbitan fatty acid ester ([[]) together in a specific ratio, an agricultural film exhibiting excellent fog-proofing and anti-fogging properties, which is the gist of the present invention, can be produced. It is.

The reason why the combination of the compound of the general formula [Il and a specific sorbitan fatty acid ester Hihichi exhibits excellent fog-proofing and anti-fogging properties useful as an agricultural film has not yet been elucidated; It can be thought of as a combined effect when used together.

In addition, the total amount of the compound of general formula [1] and sorbitan fatty acid ester (1) added to the vinyl chloride resin is 1
Preferably, the amount is between 5% and 5% by weight, and addition of more than 5% by weight does not significantly improve performance 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.

[Effects of the Invention] The present invention provides an agricultural film that has both excellent anti-fogging properties and anti-fog properties by blending and using a specific fluorine compound and a specific sorbitan oil anti-acid ester in a specific ratio. It is something.

In other words, by using the agricultural film of the present invention, it is possible to completely prevent the formation of fog, which is often observed in greenhouses from late autumn to winter, and eliminate the above-mentioned adverse effects caused by fog formation.

At the same time, the agricultural film of the present invention exhibits excellent antifogging properties over a long period of time, making it very effective for facility cultivation such as out-of-season cultivation of crops.

〔Example〕

Next, the present invention will be explained with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 100 parts by weight of 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 dihydride Stearylamide 0.
5 parts by weight and 2 parts by weight of the composition A of the present invention Composition A of the present invention; Reaction product of 1 mole and 2 moles of 36 moles of ethylene oxide added to sorbitol [1]...20 parts by weight Sorbitan palmitylic acid (1,2 mol) ester [0]...
...80 parts by weight were mixed and a 100 micron film was prepared using a calendar roll.

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

The fog generation situation was observed and the corrosion resistance was evaluated using the following method.

Fog observation method Tests began in late October. The water temperature in the aquarium set up in the experimental greenhouse was increased to 40°C in the morning and evening when the temperature drops.
The fog generation and drying conditions inside the greenhouse were 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.

◎・・・・・・No fog generation was observed.

Oo: Slight occurrence of fog is observed.

Δ: Formation of fog is observed.

×: Significant fog formation is observed.

Method for evaluating anti-fogging property Along with the observation of fog, the corrosion resistance of the inner surface of the film placed in the experimental greenhouse was periodically observed over a period of 10 months.

Antifogging properties were evaluated based on the following criteria.

◎・・・・・・Status where no water droplets are observed○・
...Status where a slight amount of water droplets are observed Δ...Situation where water droplets are observed ×...
・Condition where a considerable amount of water droplets are observed XX...Condition where water droplets are attached over the entire surface The results are shown in Table 1, and the film containing Composition A according to the present invention has excellent fog-proofing properties. It can be seen that it exhibits anti-fog properties.

Examples 2 to 7 Films containing Compositions B to G according to the present invention listed in Table 1 were prepared in the same manner as in Example 1 to obtain Examples 2 to 7. (Results are shown in Table 2) Comparative Example 1' Comparative Example 1 was obtained by producing a film in which the amount of composition A added was 0.5 parts by weight in the same manner as in Example 1.

Comparative Example 2 A fluorine compound according to the present invention [
Comparative Example 2 was prepared by adding composition B' in which the blending ratio of N and sorbitan fatty acid ester [II] was outside the range of the present invention.

Composition B': Fluorine compound (I) of Example 2...5% by weight Example 2
Sorbitan fatty acid ester (II)...95% by weight Comparative Examples 3 to 6 The following compositions H to other than the present invention were prepared in the same manner as in Example 1.
Films to which Composition K was added were created to obtain Comparative Examples 3 to 6.

Composition H: Reaction product of 1 mol of 36 mol adduct of ethylene oxide of sorbitol and 6 mol 20 parts by weight Sorbitan stearic acid (1.2 mol) ester 80 parts by weight Composition Materials: Reaction product of 21 moles of propylene oxide added to glycerin, 1 mole and 1.5 moles...25 parts by weight Sorbitan balmitic acid (1.5 moles) ester... 7
5 parts by weight Composition J: Reaction product of 1 mol and 3 mol of 150 mol of ethylene oxide of sorbitol... 30 parts by weight Sorbitan stearic acid (1.2 mol) ester... 70 parts by weight of the composition: Reaction product of 1 mol and 2 mol of random addition molar dispersion of 40 mol of ethylene oxide and 12 mol of propylene oxide of sorbitan...15 parts by weight of sorbitan lauric acid (1,4 Mol) Ester...82 parts by weight The results of the comparative example are shown in Table 2.

As is clear from Table 2, it is clear that the agricultural film containing the composition of the present invention exhibits excellent anti-fog and anti-fog properties.

Patent applicant: Toho Chemical Industry Co., Ltd. Procedural amendment (voluntary) June 16, 1988 Director General of the Patent Office Kunio Ogawa 1, Indication of the case 1988 Patent Application No. 161208 2, Title of the invention 3, Amendment Relation to the case of a person who makes a claim Patent applicant Column 5 of “Claims” and “Detailed Description of the Invention” Contents of amendments (1) As per the attached appendix to the scope of claims "Q is an integer between 1 and (χ-Q)" in lines 4 and 5 on page 8 of the Explanatory Specification is corrected to "Q is an integer between 1 and (χ-1)."

[11 and below - Dilation [! ] Fluorine compound and sorbitan fat axy, -? k (+1) tt (
1) : (II) =50 : 50-10 :
A method for producing an agricultural film with excellent electrical resistance and fog resistance, characterized by adding 1 to 5% by weight of vinyl chloride resin at a weight ratio of 90+71.

[However, A is a polyhydric alcohol residue, R1 and R2 are hydrogen atoms or methyl groups (however, R and R are not methyl groups), m and n are integers of 1 or more, and m+n=2 An integer of ~20, χ is o of the polyhydric alcohol
The number of H groups, Q, is an integer greater than or equal to "Y".

B represents (where Rf is a perfluoroalkyl group having 4 to 10 carbon atoms)](2) Claim (1) wherein the polyhydric alcohol is glycerin, diglycerin, sorbitol, sorbitan, or pentaerythritol A method for producing the agricultural film described.

(3) A method for producing an agricultural film according to claim (1), wherein the sorbitan fatty acid ester is obtained by reacting 1 mole of sorbitol with 1 to 1.5 moles of higher fatty acid having 16 to 18 carbon atoms. Procedural amendment (November 1988) 5th Director General of the Patent Office Yoshi 1) Takeshi Moon 1, Indication of the case Patent Application No. 161208 of 1988 2, Name of the invention Process for manufacturing agricultural film 3, Person making the amendment Relationship to the case Patent applicant November 1, 1988 5. Target of amendment Column (2) of the contents of the amendment in the "procedural amendment (voluntary)" submitted on June 16, 1988 6. Contents of the amendment (2) Correct “Q is an integer from 1 to (X-fl)” in lines 5 and 6 on page 8 of the detailed description of the invention to “Q is an integer from 1 to (x-1)” .

Claims (1)

[Claims] A fluorine compound represented by the following general formula [I] and a sorbitan fatty acid ester [II] [I]:[II]=50
1 to vinyl chloride resin at a weight ratio of 50 to 10:90.
A method for producing an agricultural film with excellent anti-fog and anti-fog properties, characterized by adding ~5% by weight. General formula [I]: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [However, A is a polyhydric alcohol residue, R_1 and R_
2 is a hydrogen atom or a methyl group (however, R_1, R_
2 are both methyl groups), m and n are integers of 1 or more, m + n = integer of 2 to 20, x is the number of OH groups of the polyhydric alcohol, l is an integer of 1 to (x-l) , B represents a ▲ group with numerical formulas, chemical formulas, tables, etc. (however, R_f is a perfluoroalkyl group having 4 to 10 carbon atoms). (2) The method for producing an agricultural film according to claim (1), wherein the polyhydric alcohol is glycerin, diglycerin, sorbitol, sorbitan, or pentaerythritol. (3) The sorbitan fatty acid ester is a mixture of 1 mole of sorbitol and carbon. A method for producing an agricultural film according to claim (1) obtained by reacting 1 to 1.5 moles of higher fatty acids of numbers 16 to 18.