JP3018094B2 - Agricultural vinyl film manufacturing method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing a vinyl film for agricultural use, and more particularly, to a method for cultivating an agricultural house or a tunnel for the purpose of out-of-season cultivation of agricultural crops and the like. The present invention relates to a method for producing an anti-fogging polyvinyl chloride resin film used for the like.

[Conventional technology]

BACKGROUND ART As a covering material for agriculture such as an agricultural house or a tunnel, a polyvinyl chloride resin film is widely used for the purpose of keeping heat, and early or out-of-season growth of agricultural crops is performed.

When using polyvinyl chloride film as a coating material,
Since the film surface is hydrophobic, water vapor evaporated from the ground surface or crops in an agricultural house or tunnel is condensed on the film surface in the house and adheres in the form of mist to form a cloud on the film surface. For this reason, the penetration of sunlight is deteriorated, and the rate of temperature rise in the agricultural house is reduced, thereby significantly inhibiting the growth of the crop. In order to prevent water droplets from adhering to the film surface, conventionally, during the production of a polyvinyl chloride resin film, an antifogging agent has been added to hydrophilize the film surface to prevent water droplets from adhering. Conventionally, nonionic surfactants such as sorbitan fatty acid esters, glycerin fatty acid esters, diglycerin fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxypropylene sorbitan fatty acid esters have been exclusively used as antifoggants.

[Problems to be solved by the invention]

The anti-fog performance required for the above-mentioned agricultural vinyl film is as follows: (1) Even in winter when the temperature is low, no water droplets adhere to the film surface in the house and the film surface does not fog. (Low-temperature anti-fogging property) (2) The anti-fogging property is not impaired during the growing period of the crop,
In particular, although the antifogging property is maintained (sustainability) even when used from summer to winter, agricultural films that satisfy both low-temperature antifogging property and sustainability have been found with conventional antifogging agents. It has not been done yet. The present inventors have made intensive efforts on the above-mentioned agricultural vinyl chloride film having excellent low-temperature antifogging property and long-lasting property, and have reached the present invention.

[Means for solving the problem]

The present invention relates to a method in which 1 mol of a polyhydric alcohol (sorbitol, sorbitan, diglycerin) and 1 to 2 mol of a higher fatty acid having 12 to 22 carbon atoms are condensed with 1 mol of a polyhydric alcohol fatty acid ester obtained by 2 to 3 moles. -Epoxy-
The present invention relates to a method for producing a vinyl chloride film for agricultural use, which is excellent in both low-temperature antifogging property and durability, characterized by adding a compound obtained by adding 0.1 to 2 mol of 1-propanol.

 Hereinafter, the present invention will be described in detail.

Examples of the vinyl chloride resin used in the present invention include vinyl chloride homopolymer, vinyl chloride and vinyl acetate and its ester, acrylic acid and its ester, methacrylic acid and its ester, ethylene, propylene, vinylidene chloride, and maleic acid. , Fumaric acid and the like.

The compound according to the present invention, first, 1 to 2 moles of higher fatty acid having 12 to 22 carbon atoms to 1 mole of polyhydric alcohol such as sorbitol or sorbitan or diglycerin according to a conventional method such as sodium hydroxide, potassium hydroxide or potassium carbonate. A dehydration reaction (esterification reaction) is carried out in the presence of an alkali catalyst to obtain a higher fatty acid ester of a polyhydric alcohol. Then, 2,3-epoxy-1-propanol, 0.1 to 2 mol is added to 1 mol of the esterified product, It is obtained by an addition reaction in the presence of an acidic catalyst.

As the polyhydric alcohol to be used, sorbitol is particularly preferable in view of low-temperature antifogging property and economical efficiency, and has 12 to 22 carbon atoms.
Examples of higher fatty acids include coconut fatty acid, lauric acid, myristic acid, palmitic acid, stearic acid, etc., and most preferably, palmitic acid and stearic acid. The compounds according to the present invention derived from higher fatty acids having 12 to 14 carbon atoms have excellent low-temperature antifogging properties but are somewhat inferior in sustainability.

The number of moles of the higher fatty acid reacted with respect to 1 mole of the polyhydric alcohol is preferably in the range of 1 to 2 moles, particularly preferably 1 to 1.5 moles. If it exceeds 2 moles, the antifogging property becomes poor, which is not preferable.

Further, the number of moles of 2,3-epoxy-1-propanol reacted with respect to 1 mole of the higher fatty acid ester of polyhydric alcohol is preferably in the range of 0.1 to 2 moles, particularly preferably in the range of 0.5 to 1.0 mole. If it exceeds 2 mol, the durability is poor and it is not preferable.

Further, the amount of the compound of the present invention to be added to the vinyl chloride resin is usually preferably 1 to 5% by weight, and if it exceeds 5% by weight, the performance is not improved so much and it is economically disadvantageous.

The agricultural film of the present invention is, as is known, soft vinyl chloride, and usually 3 parts per 100 parts by weight of the vinyl chloride resin.
0 to 70 parts by weight of a plasticizer is appropriately used, and a stabilizer, a lubricant, an ultraviolet absorber, an antioxidant, a colorant and the like are used as needed.

Thus, the vinyl oxide resin composition containing the compound of the present invention is formed into a film by a known method such as a calendering method and a melt extrusion method.

〔Example〕

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

 1 shows a synthesis example of a compound according to the present invention.

(Synthesis Example 1) In a flask equipped with a thermometer, a nitrogen gas inlet tube, and a water sample tube, 260 g (1 mol) of a 70% sorbitol aqueous solution, an average molecular weight of 280 having a composition of 65% by weight of stearic acid and 35% by weight of palmitic acid. Charge 336 g (1.2 mol) of higher fatty acid and 1.2 g of 96% potassium hydroxide as a catalyst, gradually raise the temperature while introducing nitrogen gas with stirring, and perform a dehydration reaction (esterification reaction).
Started. Perform a dehydration reaction at 230 ° C for 6 hours, acid value 2.2,
A sorbitan higher fatty acid ester having a saponification value of 142 and a melting point of 55.0 ° C. was obtained.

Then, after the reaction product was cooled to 80 ° C.,
75 g (1 mol) of 3-epoxy-1-propanol is added to about 2
It took a long time and the solution was added dropwise while maintaining the temperature at 80 to 90 ° C.

After completion of the dropwise addition, the mixture was aged at the same temperature for 1 hour to obtain a 2,3-epoxy-1-propanol adduct of a sorbitan higher fatty acid ester.

This adduct was a solid having an acid value of 0.5, a saponification value of 120 and a melting point of 50.5 ° C.

(Synthesis Examples 2 to 10) In the same manner as in Synthesis Example 1, Synthesis Examples 2 to 2 shown in Table 1 were used.
The compound of Synthesis Example 8 according to the present invention was obtained.

(Example 1) 100 parts by weight of a 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, 0.5 parts by weight of methylenebisstearylamide and 2 parts by weight of the compound of Synthesis Example 1 of the present invention were mixed to prepare a 100-micron film using a calender roll.

This film was attached to a frame assembled on an outdoor water tank to form a greenhouse for experiments, and the antifogging property was evaluated by the following method.

Evaluation method of anti-fogging property The test was started from the middle of September.

During the time when the temperature in the morning and evening decreased, the antifogging property of the inner surface of the film stretched in the experimental greenhouse was periodically observed for 10 months.

 The antifogging property was evaluated according to the following criteria.

◎: State where no water droplets are observed at all ○: State where slight water droplets are observed…: State where water droplets are observed ×: State where considerable water droplets are observed ×: Whole surface The results are shown in Table 2, which shows that the film to which the compound of Synthesis Example 1 according to the present invention is added exhibits excellent low-temperature antifogging property and persistence.

(Examples 2 to 8) In the same manner as in Example 1, the above Synthesis Examples 2 to 2 according to the present invention.
Films to which the compound of Example 8 was added were prepared.
I got

 Table 2 shows the results.

At the same time, comparative compounds (compounds of Comparative Example 1 to compounds of Comparative Example 6) outside the present invention shown in Table 3 were also examined.

 The results are shown in Table 2 together with the examples.

〔The invention's effect〕

As shown in Table 2, the compounds of Synthesis Examples 1 to 8 according to the present invention have low-temperature antifogging properties and It is possible to demonstrate sustainability.

Continuation of the front page (56) References JP-A-52-69954 (JP, A) JP-A-60-120737 (JP, A) JP-A-62-220552 (JP, A) JP-A-64-6046 (JP) , A) JP-A-2-296849 (JP, A) JP-B-49-26503 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 27/06 C08K 5/10

Claims (1)

(57) [Claims] (1) 1,3-mol of polyhydric alcohol (sorbitol, sorbitan, diglycerin) and 1-2 mol of polyhydric alcohol fatty acid ester obtained by condensation reaction of 1 to 2 mol of higher fatty acid having 12 to 22 carbon atoms. A method for producing an agricultural vinyl film having an excellent antifogging effect, comprising adding a compound obtained by adding 0.1 to 2 mol of epoxy-1-propanol.