JPH0583208B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to agricultural vinyl chloride resin films,
This invention relates to an agricultural vinyl chloride resin film that has excellent antifogging properties at low temperatures, especially when used in regions with severe winter temperatures. [Prior Art] In recent years, greenhouse horticulture has been on the rise due to its ability to increase profits through forced cultivation or controlled cultivation of useful plants. The covering materials used for this greenhouse horticulture include:
Polyethylene film, ethylene-vinyl acetate copolymer film, polycarbonate film, methyl methacrylate resin film, acrylic resin film, vinyl chloride resin film, glass, etc. are used. Among them, agricultural vinyl chloride resin films containing a large amount of plasticizer are widely used because they have superior light transmittance, heat retention, mechanical strength, and weather resistance compared to other synthetic resin films. . By the way, since the surface of a vinyl chloride resin film is hydrophobic, when it is spread in a house, water vapor generated inside the house becomes water droplets and condenses on the inner surface of the film. For this reason, the condensed water droplets not only significantly reduce light transmission and block sunlight from irradiating the cultivated crops, but also fall onto the cultivated crops, damaging the crops and, in some cases, causing disease. Conventionally, in order to solve this problem, we imparted hydrophilicity to vinyl chloride resin so that the water droplets that condensed on the surface flowed down while uniformly wetting it, in order to prevent the occurrence of fogging due to dew condensation on the inner surface of the film. Antifogging agents have been incorporated into vinyl chloride resin compositions before film molding. Antifogging agents generally include sorbitan surfactants such as sorbitan monostearate, sorbitan monopalmitate, and sorbitan monobenzoate, and glycerin surfactants such as glycerin monolaurate, diglycerin monopalmitate, and glycerin monostearate. Active agents, polyethylene glycol-based surfactants such as polyethylene glycol monostearate and polyethylene glycol monopalmitate, and esters of condensates of sorbitan and glycerin with organic acids are known, and these surfactants can also be used alone. or a combination of two or more types. However, although these commonly used antifogging agents have antifogging properties at low temperatures when used in normal warm regions, their antifogging properties at low temperatures are insufficient when used in regions with severe winter temperatures. It was hot. In order to further improve hydrophilicity and speed up the flow time of condensed water, surfactants with alkylene oxide, especially ethylene oxide added to the above surfactants are used to address these problems, but performance improvements at low temperatures are still insufficient. Furthermore, since the hydrophilicity was improved, the long-lasting effect as an antifogging agent was reduced. To deal with this, it is possible to have a lasting effect by increasing the amount of antifogging agent added, but if a large amount of antifogging agent is used, the antifogging agent will bleed over time and the film will become sticky. Furthermore, there is a problem that the film itself whitens, and no film has yet been found that has both antifogging properties and durability at low temperatures. [Problems to be Solved by the Invention] An object of the present invention is to provide an agricultural vinyl chloride resin film that has excellent antifogging properties at low temperatures and has a sustained antifogging effect. [Means for Solving the Problems] In order to achieve the above object, the present inventors have made extensive studies and have found that an alkylene oxide adduct of a nonylphenol formalin condensate and a sorbitan ester are used together in a specific weight ratio. The present inventors have discovered that an agricultural vinyl chloride resin film having excellent low-temperature antifogging properties and maintaining antifogging properties over a long period of time can be obtained by using the above method, and has arrived at the present invention. That is, the present invention contains a total of 0.5 to 4 parts by weight of a compound obtained by adding 1 to 30 moles of alkylene oxide to a nonylphenol formalin condensate and a sorbitan ester, per 100 parts by weight of a vinyl chloride resin, and The mixing ratio of the alkylene oxide adduct of the nonylphenol/formalin condensate and the sorbitan ester is 1/9 to 5/5 by weight.
This is an agricultural vinyl chloride resin film characterized by the following: As the vinyl chloride resin used in the present invention, not only polyvinyl chloride but also copolymers containing vinyl chloride as a main component can be used. Monomers that can be copolymerized with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, vinyl acetate, maleic acid, itaconic acid,
Examples include acrylic acid and methacrylic acid. In the present invention, a compound obtained by adding an alkylene oxide to a nonylphenol/formalin condensate and a sorbitan ester are used in combination. The nonylphenol-formalin condensate, which is the raw material for the compound obtained by adding an alkylene oxide to the nonylphenol-formalin condensate, which is the active ingredient of the present invention, can be prepared using known techniques such as mixing nonylphenol and formalin in a solvent, using an acid or alkali catalyst. It can be obtained by condensation by heating in the presence of The degree of condensation is preferably 2 to 10, and those having a degree of condensation of 3 to 7 are particularly preferable from the viewpoint of long-lasting performance of the antifogging agent. Note that the degree of condensation corresponds to the number of nonylphenols in one condensate. Further, the compound obtained by adding alkylene oxide to the nonylphenol/formalin condensate is one in which ethylene oxide and/or propylene oxide is added to the formalin condensate. Addition of alkylene oxide to the nonylphenol-formalin condensate is carried out using known techniques, for example, by adding alkylene oxide to the condensate under heating in the presence of an alkali catalyst. The amount of alkylene oxide added is preferably 1 to 30 moles when only ethylene oxide is added. In particular, when the addition rate is 1 to 15 moles, the antifogging effect is long-lasting. The effective antifogging agent composition in the present invention is a combination of 1 to 30 moles of alkylene oxide adduct of the nonylphenol-formalin condensate and sorbitan ester, and these may be used in combination. As the sorbitan ester, sorbitan stearate or sorbitan palmitate is preferred. Esters of fatty acids with fewer than 15 carbon atoms have good initial effects, but lack sustainability. On the other hand, esters of fatty acids with a carbon number greater than 19 have good sustainability, but the initial effect is poor. The mixing ratio of the alkylene oxide adduct of the nonylphenol/formalin condensate and the sorbitan ester is preferably 1/9 to 5/5, more preferably 2/8 to 4/6, by weight. 1/
If it is smaller than 9, the initial effect will be inferior, and 5/
If it is greater than 5, the lasting effect will be poor. The amount of the antifogging agent added is preferably 0.5 to 4 parts by weight, more preferably 1 to 3 parts by weight per 100 parts by weight of the vinyl chloride resin. If the amount added is less than 0.5 part by weight, the antifogging performance will be poor, which is not preferable.
On the other hand, if the amount is more than 4 parts by weight, the film becomes sticky or whites easily due to bleeding, and the commercial value decreases. The film according to the present invention may contain other resin additives, such as plasticizers, lubricants, heat stabilizers, antioxidants, ultraviolet absorbers, pigments, dyes, etc., as necessary. Examples of the plasticizer include phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate, ditridecyl phthalate, and diundecyl phthalate; isophthalic acid derivatives such as diisooctyl isophthalate; Adipic acid derivatives such as di-n-butyl adipate and dioctyl adipate, maleic acid derivatives such as di-n-butyl maleate, citric acid derivatives such as tri-n-butyl citrate, itaconic acid derivatives such as monobutyl itaconate, butyl oleate, etc. Examples include oleic acid derivatives and ricinoleic acid derivatives such as glycerin monolysylate. The above plasticizers may be used alone or in combination of two or more, and the amount used is usually 30 to 60 parts by weight per 100 parts by weight of the vinyl chloride resin. Examples of the phosphoric acid ester plasticizer include tricresyl phosphate and tricylenyl phosphate. The use of a phosphoric acid ester plasticizer is preferred from the viewpoint of improving weather resistance, and the appropriate amount is usually 1 to 10 parts by weight per 100 parts by weight of the vinyl chloride resin. Epoxy compounds include epoxidized soybean oil,
Ester such as epoxidized linseed oil, epoxidized tall oil fatty acid ester, epoxidized tallow oil, epoxidized polybutadiene, epoxidized methyl stearate, epoxidized butyl stearate, epoxidized 2-ethylhexyl stearate, epoxidized stearyl stearate, Tris (epoxypropyl) isocyanurate, epoxidized castor oil, epoxidized safflower oil, epoxidized linseed oil fatty acid butyl, 3-(2-xenoxy)-1,2
-Epoxypropane, bisphenol A diglycidyl ether, vinylcyclohexene diepoxide, dicyclopentene diepoxide, 3,4
-epoxy-6-methylcyclohexylmethyl,
Examples include 3,4-epoxy-6-methylcyclohexanecarboxylate. The appropriate amount of these epoxy compounds to be used is usually 0.5 to 7 parts by weight per 100 parts by weight of the vinyl chloride resin. Examples of lubricants and heat stabilizers include polyethylene wax, liquid paraffin, stearic acid, zinc stearate, aliphatic alcohol, calcium stearate, barium stearate, barium ricinoleate, dioctyltin dilaurate, dioctyltin malate, and phenols. , organic phosphite compounds, β-diketone compounds, and the like. Examples of UV absorbers include hydroquinone-based UV absorbers, salicylic acid-based UV absorbers, benzophenone-based UV absorbers, and benzotriazole-based UV absorbers. It may be desirable to use a UV absorber in combination. The basic vinyl chloride resin composition is a mixture of vinyl chloride resin, alkylene oxide adduct of nonylphenol/formalin condensate, sorbitan ester, and other resin additives, and is used in ribbon blenders, Banbury mixers, and super mixers. , by mixing with a Henschel mixer or the like. The film according to the present invention is produced from the above composition by a known film forming technique. Known film forming techniques include calendar molding, T-die extrusion, inflation molding, and solution casting. If the thickness of the film according to the present invention is too thin, the strength will be insufficient, so it is not preferable.On the other hand, if it is too thick, it will be difficult to make the film into a film, and other handling (cutting the film and joining it into a house shape) will be required.
Usually 0.03~0.3mm, preferably 0.05~0.
0.2mm is appropriate. Further, the film of the present invention may be coated with a resin such as acrylate resin or polyvinylidene fluoride to impart dustproof properties. [Example] The present invention will be explained below with reference to Examples. Examples 1 to 6, Comparative Examples 1 to 6 The type and amount of antifogging agent shown in Table 2 was added to the basic formulation shown in Table 1 below, and the mixture was mixed with a Henschel mixer.
After mixing for 10 minutes and roll kneading at 165°C, an agricultural vinyl chloride resin film (hereinafter abbreviated as agricultural vinyl) having a thickness of 0.10 mm was produced using an L-shaped calender.

【table】

【table】

〔Effect of the invention〕

As is clear from the above examples, the film using the antifogging agent of the present invention has better effects at low temperatures (flow start time, surface condition) than conventional antifogging agents, and has a sustained effect. It is also excellent. On the other hand, when the amount of the antifogging agent of the present invention added exceeds 4 parts by weight, the low-temperature antifogging property, surface condition, and durability are good, but the gushing phenomenon is likely to occur. Furthermore, if the amount of the antifogging agent of the present invention added is less than 0.5 parts by weight, the antifogging performance will be less effective. The agricultural vinyl chloride resin film according to the present invention has the following effects and greatly contributes to greenhouse horticulture. Since it has good anti-fog properties at low temperatures, it exhibits sufficient anti-fog effects even in extremely cold regions. Since it has a good anti-fog effect, it is possible to secure a sufficient amount of light even in the winter when there are few hours of sunlight, creating a favorable environment for crop cultivation. Because of its good sustainability, it can prevent water droplets from falling over a long period of time, and it can also ensure a sufficient amount of light until the crop is harvested, so it can be expected to improve the quality and yield of crops. Because the inner surface is in good condition, a uniform beam of light can be obtained, and the inside of the house can be easily observed from the outside.

Claims (1)

[Scope of Claims] 1. Contains a total of 0.5 to 4 parts by weight of a compound obtained by adding 1 to 30 moles of alkylene oxide to a nonylphenol formalin condensate and sorbitan ester per 100 parts by weight of a vinyl chloride resin, and ,
An agricultural vinyl chloride resin film characterized in that a mixing ratio of the alkylene oxide adduct of the nonylphenol formalin condensate and the sorbitan ester is from 1/9 to 5/5 by weight. 2. The agricultural vinyl chloride resin film according to claim 1, wherein the alkylene oxide is ethylene oxide and/or propylene oxide. 3. The agricultural vinyl chloride resin film according to claim 1, wherein the sorbitan ester is sorbitan stearate and/or sorbitan palmitate.