JPS63182363A - Production of agricultural film having excellent fog-proofness and anti-clouding property - Google Patents

Abstract

PURPOSE:To produce an agricultural film which prevents fogging of green houses and can exhibit excellent anti-clouding properties over a long period of time, by blending several compds. each having a specified sorbitan ring in a specified ratio. CONSTITUTION:1-5wt.% in total of a sorbitan fatty acid ester and/or a poly oxyalkylenesorbitan fatty acid ester (A) and a sorbitan perfluoroalkyl methylcarboxylate and/or a polyoxyalkylensolbitan perfluoroalkyl methylcarboxylate (B) in a weight ratio of A to B of 95:5-60:40 is added to a vinyl chloride resin to produce the title film. When the agricultural film is used, fogging from the end of the fall to the winter can be completely prevented and excellent anti-clouding properties can be exhibited over a long period of time.

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, R'llL does not generate fog in agricultural greenhouses and exhibits excellent anti-fog properties over a long period of time.
It is related to a film for use. [Prior Art] In recent years, crop cultivation in agricultural greenhouses, tunnels, etc. using synthetic resin films has been widely practiced for the purpose of early growth or out-of-season growth of 111 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. The surface of the film becomes significantly cloudy without exhibiting the so-called wetting phenomenon. For two reasons, 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 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. . However, the above-mentioned anti-fogging agent is added to a commercial greenhouse. Although it allows good sunlight to pass through and has an excellent temperature-raising effect, it has 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.
As a result, visibility inside the house is extremely poor, resulting in disadvantages such as reduced work efficiency. The second fog phenomenon is often observed from late autumn to winter when the outside temperature is low in the mornings and evenings. The direct cause of such n generation in an agricultural greenhouse is that the water vapor pressure 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 brings disadvantages such as extremely poor visibility inside the greenhouse and reduced work efficiency. This fog formation phenomenon is often observed during the period from late autumn to winter when the outside temperature is low in the morning and evening.2The direct cause of such fog formation in agricultural greenhouses is that the difference in temperature inside and outside the greenhouse causes The water vapor reaches the saturated vapor pressure or higher. In other words, early morning fog evaporates from the ground surface inside the greenhouse. When the water vapor comes into contact with the cold air above the greenhouse, it condenses into water droplets and becomes fog.Evening fog is caused by the nearly saturated water vapor inside the greenhouse condensing as the temperature above the greenhouse falls, turning into water droplets and becoming fog. Furthermore, the amount of fog and factors that promote fog generation will be considered. One of them is the presence of condensation tuberculosis within the house. It is inferred that the water vapor rising from the ground surface of the house promotes condensation II (generation of fl) using dust etc. inside the house as nuclei. This varies depending on the location and environment of the house. It is also thought that the degree of hydrophilicity of the film surface inside 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 the collision of water vapor evaporated from the ground surface of the greenhouse, one is the rebound of the collided water vapor into the inside of the house, and the other is the flow of water down the film surface. This is a re-evaporation phenomenon of water inside 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 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, increasing the saturated water vapor pressure by heating the house, and using colored films. However, all of these methods had drawbacks and were not satisfactory. In addition, the method of adding an organic siloxane surfactant described in JP-A No. 55-91663 and the method of adding an organic siloxane surfactant described in JP-A No.
Although methods such as adding a certain type of fluorine-based surfactant described in Publication No. 7-14648 have been proposed, none of them completely suppresses the generation of fog, and even if they have an anti-fog effect, There are still drawbacks, such as a reduction in the long-term antifogging effect that is basically required for agricultural films. (The problem that IA Ming tried to solve) The present inventors have developed 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. The present invention was achieved as a result of diligent efforts aimed at producing sorbitan fatty acid esters.

[1] and/or polyoxyalkylene sorbitan fatty acid ester [
1゛] and sorbitan perfluoroalkyl carboxylic acid ester [0] and/or polyoxyalkylene sorbitan perfluoroalkyl carboxylic acid ester [n''] ((11+(1')) : ((LmJ
0'l) -95: Production of an agricultural film with excellent anti-fog and anti-fog properties characterized by adding 1 to 5% by weight of vinyl chloride resin at a weight ratio of 5 to 60:40. It is about the method. The present invention will be explained in detail below. In addition to vinyl chloride homopolymer, vinyl chloride resins used in the present invention include vinyl chloride and vinyl acetate and their esters, acrylic acid and its esters, methacrylic acid and its esters, ethylene, propylene, vinylidene chloride, and maleic acid. . Copolymers such as fumaric acid are included, and vinyl chloride resin is preferred among them. The sorbitan fatty acid ester used in the present invention consists of 1 mole of sorbitol and a higher fatty acid having 12 to 18 carbon atoms] ~1.
It is obtained by a dehydration reaction of 5 mol with a conventional method,
Examples of higher fatty acids having 12 to 18 carbon atoms include coconut fatty acid, lauric acid, myristic acid, palmitic acid, stearic acid, and cape oleic acid, but palmitic acid and stearic acid are preferable in terms of effectiveness. The number of moles of fatty acid is in the range of 1 to 1.5 moles, and if it exceeds 1.5 moles, the antifogging properties will be poor, which is not preferable. In addition, the polyoxyalkylene sorbitan fatty acid ester used in the present invention contains 1 mole of sorbitol and 12 to 12 carbon atoms.
It is obtained by adding 1 to 20 moles of ethylene oxide or 0.5 to 5 moles of propylene oxide by a conventional method to 1 mole of fatty acid ester obtained by reacting 1 to 2 moles of higher fatty acid No. 18. Therefore, partic acid and stearic acid are preferred as higher fatty acids.The number of moles of higher fatty acids per mole of sorbitol may be in the range of 1 to 2 moles, and if it exceeds 2 moles, the antifogging property becomes poor and is not preferred. Further, the number of moles of ethylene oxide added is preferably in the range of 3 to 20 moles when used in combination with the sorbitan fatty acid ester, and preferably in the range of 1 to 2 moles when used alone with the polyoxyalkylene sorbitan fatty acid ester. Give results. The number of moles of propylene oxide added is 0, including when used in combination with the sorbitan fatty acid ester.
．． The range of 5 to 1 mol is particularly preferable from the viewpoint of antifogging effect;
Addition of more than a molar amount is not preferable because fog prevention properties become poor. Further, the sorbitan perfluoroalkyl carboxylic acid ester used in the present invention contains 1 mole of sorbitol and 5 to 9 carbon atoms.
It is obtained by dehydrating 1 to 2 moles of perfluoroalkylcarboxylic acid in a conventional manner, and when used alone without using in combination with polyoxyalkylene sorbitan perfluoroalkylcarboxylic acid ester, per mole of sorbitol. The range of 1 to 1.5 moles of perfluoroalkyl carboxylic acid is preferable from the viewpoint of antifogging effect. The polyoxyalkylene sorbitan perproloalkyl carboxylic acid ester used in the present invention has 1 mole of sorbitol and a carbon number of 5 to 9. It is obtained by adding 1 to 50 moles of ethylene oxide and/or 0.5 to 10 moles of propylene oxide to 1 mole of perfluoroalkyl carboxylic acid ester by a conventional method, and is obtained by adding 0.5 to 10 moles of ethylene oxide and/or propylene oxide to 1 mole of perfluoroalkyl carboxylic acid ester. The number of moles of ethylene oxide added is preferably in the range of 1 to 30 moles (when polyoxyethylene sorbitan perfluoroalkyl carboxylic acid ester to which only ethylene oxide is added) is in the range of 1 to 30 moles. Although there is no problem with the anti-fog property, the long-term anti-fog property is particularly poor. The number of moles of propylene oxide added is 0, including when it is used in combination with the sorbitan perfluoroalkyl carboxylic acid ester (when using polyoxypropylene sorbitan perproloalkyl carboxylic ester to which only propylene oxide is added).
．． A range of 5 to 1 mole is effective. Further, when both ethylene oxide and propylene oxide are added, preferably the addition is carried out in the range of ethylene oxide:propylene oxide #3:1 to 5:1 (molar ratio). The effect of adding ethylene oxide and propylene oxide is the same whether it is added in blocks or randomly. In the present invention, (1) according to the present invention and [! When the compounds (1) and (I') are added alone to a vinyl chloride resin, the compounds (1) and (I') exhibit an antifogging effect, but the compounds (II) and [n'] exhibit antifogging effects. There are very few (
The compounds n) and [■'] have insufficient fog-proofing properties and anti-fogging properties and cannot be put to practical use. However, the compound (1) and l or [I'] and (n
) and l or [■'] in a specific ratio, an agricultural film exhibiting excellent anti-fogging and fog-proofing properties, which is the gist of the present invention, can be produced. . A compound of (1) and l or [I'] having a sorbitan ring and CI+) and l or [■'
The present inventors have based on the knowledge obtained from many years of research experience on antifogging agents for agricultural films as the reason why the combination of two and two compounds exhibits mutually excellent antifogging and antifogging properties. The following considerations were made. In other words, considering the fog generation mechanism mentioned above, in order to suppress fog generation, it is essential to keep the water vapor concentration above the inside of the house below the saturated vapor pressure at all times. To achieve this, the key is how quickly the water vapor that collides with the inner surface of the film can be condensed, diffused, and flowed down onto the film surface. The factor that determines the speed of the water vapor from impact to flow down is the degree of expansion of the water droplets condensed on the film surface. The second degree of expansion is determined by the degree of hydrophilicity of the anti-fog layer formed on the film surface by the anti-fog agent, and the more stable the anti-fog agent, which is a surfactant, transfers hydrophilic groups to the air layer. It can be said that the more oriented it is, the larger it is. The compound (1) and l or (bi) according to the present invention and (
It is considered that by using compound II) and l or [n'] in combination, an antifogging layer with excellent water droplet expansion is formed. In addition, the reason for the excellent anti-fogging durability has not been elucidated yet, but compounds that have a sorbitan ring and perfluoroalkyl groups [11] and [D'] are involved. it is conceivable that. Further, the total amount of the compound (1) and/or [■'] and the compound (II) and l or [■'] added to the vinyl chloride resin is preferably 1 to 5% by weight, and preferably exceeds 5% by weight. Addition does not provide much improvement in 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 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. 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-fog and anti-fog properties by blending and using several types of compounds having specific sorbitan rings in specific proportions. . That is, by using the agricultural film of the present invention, it is possible to completely prevent the occurrence of fog, which is often observed in greenhouses from late autumn to winter. The above-mentioned adverse effects caused by fog generation can be eliminated. At the same time, the agricultural film of the present invention exhibits excellent antifogging properties over a long period of time, so it is very effective for facility cultivation such as out-of-season cultivation of a single crop. [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. Example 1 Vinyl chloride resin (degree of polymerization 1100) 10.0 parts by weight,
45 parts by weight of dioctyl phthalate, 2 parts by weight of epoxidized soybean oil
Parts by weight, 5 parts by weight of tricresyl phosphate, Ba-Z
1 part by weight of n-type metal soap, 0.5 part by weight of methylene bis stearylamide and 2 parts by weight of composition A of the present invention Composition A of the present invention: 1 mole of sorbitol and 1.2 moles of valmitic acid were mixed in a conventional manner. 75 parts by weight of sorbitan balmitic acid (1.2 mol) ester (1) obtained by dehydrating 2 mol of sorbitol and 1 mol of sorbitol and tridecafluoroheptanoic acid (C, F,
, C00H) and 2 moles of sorbitan tridecafluorohebutanoic acid (1,
Polyoxyethylene (10 moles) sorbitan obtained by adding 10 moles of ethylene oxide to 1 mole of ester (1.5 moles) of ester (n) and sorbitan tridecafluorohebutanoic acid (1.5 moles) by a conventional method. Tridecafluorohebutanoic acid (1,5 mol) ester (
II') Composition consisting of 15 parts by weight [((1)')
: (,[I]] +(II')) -75:
25 (weight ratio)) to prepare a 100 micron film using a calendar roll. An experimental greenhouse was created by placing this film on a frame assembled over an outdoor temperature-controlled aquarium, and the following methods were used to observe the fog formation and evaluate the anti-fogging properties. Examinations began in late October. The water temperature in the water tank provided in the experimental greenhouse was set to 40° C. in the morning and evening when the temperature was decreasing, and the occurrence of fog in 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 regularly until March. The degree of fog occurrence was expressed using the following criteria: 0: No fog was observed at all. 0: Slight fog was observed. Δ...Fog formation is observed.×...Fog formation is significantly observed.Method for evaluating anti-fog properties.In parallel with fog observation, the anti-fog properties of the inner surface of a film placed in an experimental greenhouse were tested for 10 months. It was observed regularly. The anti-fogging property was evaluated based on the following criteria: 0: No water droplets observed at all 0: Slight water droplets observed Δ: Water droplets Condition in which adhesion of water is observed ×゛...Condition in which considerable amount of water droplets are observed to adhere ××・
The results are shown in Table 1, in which water droplets were attached over the entire surface, and it can be seen that the film to which Composition A according to the present invention was added exhibited excellent fog-proofing properties and anti-fogging properties. Examples 2 to 6 Films to which the following compositions B to F according to the present invention were added were prepared in the same manner as in Example 1 to obtain Examples 2 to 6. The results are shown in Table 1. Composition B: Polyoxyethylene (1 mol) Sorbitan stearic acid (1,2 mol) ester [■゛]...90 parts by weight Sorbitan nonafluoropentanonic acid (1,2 mol) ester (II) ...10 parts by weight* (1')
: (n) ■90 : 10 (Heavy beam part) Composition C
: Sorbitan balmitic acid (1,5) ester N)...
...60 parts by weight polyoxyethylene (15 mol) sorbitan palmitic acid (2 mol) ester [I']... 5 parts by weight polyoxyethylene (20 mol) sorbitan to butadecafluorononanoic acid ( 1,8 mol) ester [n']...
...35 parts by weight* ([1]+ (1')): ((n')) Otori 65
: 35 (parts by weight) Composition D = Polyoxypropylene (1 mol) Sorbitan stearic acid (1.2 mol) Ester (I') Old... 95 parts by weight Polyoxypropylene (2 mol) Polyoxyethylene (
8 mol) sorbitan tridecafluorohebutanoic acid (1,
5 moles) ester [■']... 5 parts by weight IN')
: (■') m95: 5 parts by weight Composition E: Sorbitan myristic acid (1.4 mol) ester H)
...85 heavy plate polyoxypropylene (1 mol) sorbitan to butadecafluorononanoic acid (1.2 mol) ester [n']...
...15 parts by weight H): [II') 85: 15 parts by weight Composition F: Sorbitan palmitic acid (1.2 mol) ester (13
...65 parts by weight Polyoxyethylene (18 moles) Sorbitan lauric acid (1.5 moles) ester [■'] ...15 parts by weight Polyoxyethylene (25 moles) Sorbitan nonafluoropetane Nonacid (2 mol) ester [■']...
・20 parts by weight ((1) 10 (1')):
((11'))-80:20 parts by weight Comparative Example 1 Comparative Example 1 was obtained by creating 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 In the same manner as in Example 2, the composition of Composition B was [I']:
Comparative Example 2 was obtained by creating a film to which Composition G having (IT) = 30 near 0 (weight ratio) was added. Comparative Examples 3 to 7 The following compositions other than the present invention H-L were prepared in the same manner as in Example 1.
Comparative Examples 3 to 7 were prepared by creating films to which the composition was added.
I got it. Composition H: Sorbitan palmitic acid (1,2 mol) Composition I: Sorbitan tridecafluorohebutanoic acid (1,5 mol)
Ester composition J: polyoxyethylene (15 mol) sorbitan tridecafluorohebutanoic acid (2 mol) ester composition: sorbitan stearic acid (1.2 mol) ester...
... 60 parts by weight Polyoxyethylene (10 mol) Sorbitan palmitic acid (1.5 mol) Ester 20 parts by weight Polyoxyethylene (60 mol) Sorbitan nonafluorohebutanoic acid ((,5 mol) ) Ester...20 parts by weight Composition L: Sorbitan palmitic acid (2.5 mol) ester...
...75 parts by weight Polyoxyethylene (25 mol) Sorbitan nonafluorohebutanoic acid (2 mol) ester...25 parts by weight The results of the comparative example are also listed in Table 1, but the composition of the present invention It is clear that the film exhibits excellent anti-fog and anti-fog properties. Patent applicant: Toho Chemical Industry Co., Ltd. Procedure No. 117 (spontaneous) June 23, 1985 2. Title of the invention 3. Relationship with the case of the person making the amendment "Scope of claims" in the patent applicant's specification ``Perfluoroalkylcarboxylic acid'' in the column ``Invention 5, Contents of the amendment [Claims''] and ``Detailed Description of the Invention'' column ■, the page and line shown below are replaced with ``Perfluoroalkylmethyl Carboxylic acid” is corrected. 1) Page 8, lines 2-3 2) Lines 4-5 of the same page 3) Page 10, 1lN, line 12 4) Line 13 of the same page 5) Lines 15-16 of the same page 6) Lines 17-18 of the same page 7) Line 20 of the same page to line 1 of page 11 8) Line 2 of page 11 9) Line 6 of the same page 10) Lines 9 to 10 of the same page 11) Lines 14 to 15 of the same page ■, 13 of page 10 line and page 11, lines 1-2, “carbon number 5~
9" is corrected to "carbon number 6~IOJ. m, page 16 lines 5-6, same page 7-8 lines, and same page 12~
In line 13, ``rtridecafluorobutanoic acid'' is corrected to ``tridecafluorooctanoic acid''. mV, page 16, line 6, rC,F,,C00HJ is corrected to rC,F,,CH,C0OH. (2) Correct ``r-nonafluoropentanonic acid'' to ``r-nonafluorohexanoic acid'' on page 18, line 14 and page 23, lines 1-2. ■, "heptadecafluorononanoic acid" in lines 2-3 of page 19 and lines 17-18 of the same page is corrected to "heptadecafluorodecanonic acid J." ■, lines 11-1 of the same page Correct "fluorohebutanoic acid" to "fluorooctanoic acid". ■, p. 20, lines 6-7, "r nonafluoropetanoic acid" is corrected to "nonafluorohexanoic acid". ■, p. 21, line 6, and p. 21, lines 9-10. Corrected to "tridecafluorohbutanoic acid" and "tridecafluorooctanoic acid." X, on the same page, lines 16-17, "nonafluorohexanoic acid ((,5 mol) ester" is corrected to "nonafluorohexanoic acid (1,5 mol) ester". Attachment Claims "(1) ) Sorbitan fatty acid ester [I]/or polyoxyalkylene sorbitan fatty acid ester [■°] and sorbitan perfluoroalkyl indigenous carboxylic acid ester [nl and/or polyoxyalkylene sorbitan perfluoroalkylmethyl carboxylic ester [n']
] and ([1] + [bi1): ([[ko+[11'1
) = 95:5 to 60:40 weight ratio of vinyl chloride resin to vinyl chloride resin at a weight ratio of 1 to 5% by weight (2) ) Sorbitan fatty acid ester has 1 mole of sorbitol and 12 carbon atoms.
A method for producing a film for industrial use according to claim (1), which is obtained by reacting 1 to 1.5 moles of higher fatty acids of 1 to 18. (3) Polyoxyalkylene sorbitan fatty acid ester contains 1 mol of sorbitol and 1 higher fatty acid having 12 to 18 carbon atoms.
The method for producing an agricultural film according to claim (1), wherein 1 to 20 moles of ethylene oxide and/or 0.5 to 5 moles of propylene oxide are added to 1 mole of the fatty acid ester obtained by the reaction. . (4) Sorbitan perfluoroalkylmethylcarboxylic acid ester is obtained by reacting 1 mole of sorbitol with 1 to 2 moles of perfluoroalkylmethylcarboxylic acid having a carbon number of 10. Film manufacturing method. (5) Polyoxyalkylene sorbitan perfluoroalkylmethylcarboxylic acid ester contains 1 mole of sorbitol and 1 perfluoroalkylmethylcarboxylic acid having 6 to 10 carbon atoms.
1 to 50 moles of ethylene oxide and/or 0.0 moles of propylene oxide per mole of perfluoroalkylmethylcarboxylic acid ester obtained by reacting ~2 moles of ethylene oxide.
The method for producing an agricultural film according to claim (1), wherein 5 to 10 moles are added. ”

Claims (5)

[Claims] (1) Sorbitan fatty acid ester [I] and/or polyoxyalkylene sorbitan fatty acid ester [
I ′] and sorbitan perfluoroalkyl carboxylic acid ester [II] and/or polyoxyalkylene sorbitan perfluoroalkyl carboxylic acid ester [II ′] ([ I ] ten [ I ′]): ([II] + [ II′〕)=9
A method for producing an agricultural film with excellent antifogging and antifogging properties, characterized by adding 1 to 5% by weight of vinyl chloride resin at a weight ratio of 5:5 to 60:40. (2) 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 a higher fatty acid having 12 to 18 carbon atoms. (3) Polyoxyalkylene sorbitan fatty acid ester contains 1 mol of sorbitol and 1 higher fatty acid having 12 to 18 carbon atoms.
1 to 20 moles of ethylene oxide and 0.5 to 5 moles of 1 or propylene oxide are added to 1 mole of fatty acid ester obtained by the reaction of ~2 moles.The method for producing an agricultural film according to claim (1). (4) The agricultural film according to claim (1), wherein the sorbitan perfluoroalkyl carboxylic acid ester is obtained by reacting 1 mole of sorbitol with 1 to 2 moles of perfluoroalkyl carboxylic acid having 5 to 9 carbon atoms. manufacturing method (5) Polyoxyalkylene sorbitan perfluoroalkyl carboxylic acid ester contains 1 mole of sorbitol and 5 carbon atoms.
1 to 50 moles of ethylene oxide and/or 1 mole of perfluoroalkyl carboxylic acid ester obtained by reacting 1 to 2 moles of perfluoroalkyl carboxylic acid of No.
Or the method for producing an agricultural film according to claim (1), in which 0.5 to 10 moles of propylene oxide are added.