JPH0472341A - Antifogging agent for agricultural synthetic resin covering material - Google Patents

Abstract

PURPOSE:To provide the subject antifogging agent singly giving an antifogging property to films by compounding a specific fluorine-containing urethane compound as an active ingredient. CONSTITUTION:The objective antifogging agent contains a fluorine-urethane compound represented by formula I [X is the residue of a di- or higher-hydric alcohol; Y is di- or higher-valent organic group; Z is di valent organic group; R1, R2 are H, methyl, but not simultaneously methyl; R3 id H, alkyl, group of formula II (R4 is alkyl); m, n, a, b, p, q are >=1, (a+b) is the valency of the polyhydric alcohol; (p+q) is the valency of an organic group Y; Rf is 1-20C polyfluoroalkyl] and having polyfluoroalkyl groups, polyoxyalkylene groups and urethane bonds as an active ingredient, such as a group of formula III.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an anti-fog and anti-fog agent for agricultural synthetic resin coating materials. More specifically, the present invention relates to a compound that independently imparts anti-corrosion properties and anti-dew properties.

[Prior Art] In recent years, crop cultivation in greenhouses and tunnels has been widely practiced for the purpose of forced cultivation and out-of-season cultivation of agricultural and horticultural crops. Plastic films such as polyethylene film and polyvinyl chloride film are used as covering materials for these facilities, and the latter is mainly used because of its excellent light transmittance, heat retention, and weather resistance. .

However, since the surface of a polyvinyl chloride resin film is hydrophobic, water vapor condenses on the film when it is stretched, covering the surface and causing cloudiness. This not only reduces the transmittance of sunlight but also causes problems such as damage to crops due to falling water droplets. Conventionally, a method for solving such problems has been to add an antifogging agent (for example, sorbitan fatty acid ester, glycerin fatty acid ester) to vinyl chloride resin to impart hydrophilicity. As a result, the condensed water droplets are diffused onto the film surface, uniformly wetting the film, and flowing down, so that the surface can be maintained in a transparent state.

However, under a coating material containing such an antifogging agent, the temperature difference between the inside and outside of the coating material becomes large, so that a phenomenon in which fog is generated near the inner surface of the coating material is often observed. The causes of this fog phenomenon, which often occurs from late autumn to winter, are not clear, but include the temperature and humidity inside the house or tunnel, the temperature and moisture content of the soil inside the house or tunnel, the solar radiation to the house or tunnel, The degree of hydrophilicity on the inside of the sheathing material subtly influences each other, so that the moisture inside the house or tunnel smoothly adheres to the surface of the sheathing material due to temperature changes, and the phenomenon in which it does not flow away occurs, and some moisture is removed. It is presumed that this is due to the formation of mist near the inner surface of the coating material.

In order to suppress such fog generation phenomenon, Japanese Unexamined Patent Publication No. 55-9
There have been proposals for adding organic siloxane surfactants as described in JP-A No. 1663 and fluorine-based surfactants as described in JP-A-57-14648 into the film, but none of them are effective in suppressing fog generation. It has the disadvantage that it is insufficient, and even if it has a fog-proofing effect, it cannot be used unless it is used in combination with other base-preventing agents.

[Problems to be Solved by the Invention] Therefore, the present invention prevents the generation of dew in agricultural greenhouses (dew-proofing properties) and prevents fogging of vinyl films (anti-fogging properties) by adding a single compound. This invention relates to an effective anti-fog and anti-fog agent for synthetic resins.

[Means for Solving the Problems] The present inventors provide an agricultural synthetic resin coating material that has both anti-fog and dew-proof properties by adding a single compound as described above. As a result of research aimed at this purpose, it was discovered that a special fluorine-containing compound whose structure is completely different from those proposed in the past is extremely effective, leading to the completion of the present invention.

That is, the present invention does not use conventional antifogging agents in combination by adding at least one type of fluorine-containing urethane compound having a polyfluoroalkyl group, a polyoxyalkylene group, and a urethane bond represented by the following general formula [I]. It has now become possible to impart anti-fog and fog-proof properties to agricultural synthetic resin coating materials.

However, in the above-mentioned bottom, X is a polyhydric alcohol residue with a valence of 2 or more, Y is an organic group with a valence of 2 or more, 2 is a divalent organic group, and R,, R, are hydrogen atoms or methyl groups (however, R,,
R3 is a hydrogen atom or an alkyl group, or m and n, a and s, p and q are integers of 1 or more, a+b is the valence of the polyhydric alcohol, p+q represents the valence of the organic group Y. Rf represents a polyfluoroalkyl group having 1 to 20 carbon atoms, and is a perfluoroalkyl group in which all hydrogen atoms of a linear or branched alkyl group are replaced with F atoms, or a F atom of a perfluoroalkyl group. Examples include those in which some of the atoms have changed to H atoms or C1 atoms.

Specific examples of the fluorine-containing urethane compound represented by the general formula [I] of the present invention include the following.

Although the method for synthesizing the compound represented by bottom [I] is not limited in any way, it can be produced as follows. That is, alcohols containing polyfluoroalkyl groups (for example, C,F,,C2H,OH,C,F,,CH20H
etc.) and polyvalent isocyanates of divalent or higher valence (for example, 1
．． Aliphatic diisocyanates such as 6-hexamethylene diisocyanate and isophorone diisocyanate, aromatic diisocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate, and polyfunctional polymers in which 3 moles of tolylene diisocyanate are added to 1 mole of trimethylolpropane. The desired fluorine-containing urethane can be produced by reacting a polyol (for example, a polyhydric alcohol such as glycerin or ethylene glycol with ethylene oxide or propylene oxide alone or in a mixture) with a reaction product with cyanate (for example, cyanate). compound can be obtained. The fluorine-containing urethane compound obtained above can exhibit the desired anti-fogging performance and anti-fog performance, either alone or in combination of two or more.

The synthetic resin material constituting the agricultural synthetic resin coating material of the present invention generally includes film-forming thermoplastic synthetic resins. Specifically, homopolymers of monomers such as vinyl chloride, ethylene, propylene, acrylic esters, methacrylic esters, or copolymers of these monomers,
Or a small amount of these monomers (both one type and other copolymerizable monomers (e.g. vinyl acetate, vinylidene chloride, etc.)
Examples include copolymers with, fluorine-containing resins, polyesters, polyamides, etc., and blends of these polymers. Among these, vinyl chloride resins and ethylene resins are preferred from the viewpoints of weather resistance, light transmittance, economic efficiency, and strength, and polyvinyl chloride is most advantageous.

The amount of the fluorine-containing urethane compound added to the synthetic resin coating material in the present invention can be varied over a wide range depending on the type of fluorine-containing urethane compound to be blended, the type of the base synthetic resin, etc. - For boat fishing, 100 parts by weight of base synthetic resin (
However, additives such as plasticizers, antifogging agents, and stabilizers are not included.

The upper limit of the amount can be at least 0.01 part by weight (the same applies hereinafter), and the upper limit of the amount is not strictly limited, but if it is added in too much, there is a risk of bleed-out or clouding, so it is usually 2.0 parts by weight or less is sufficient. The preferred range of blending amount is base synthetic resin 100
It is 0.02 to 1.0 parts by weight per part by weight.

The synthetic resin base material constituting the agricultural covering material according to the present invention may also contain various conventional additives, such as plasticizers, lubricants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments,
Dyes and the like can be included in conventional amounts.

For example, regarding the soft vinyl chloride resin suitable for the present invention, 30 to 70 parts by weight of a plasticizer can be blended with 100 parts by weight of polyvinyl chloride having a degree of polymerization of 1000 to 2000.

Suitable plasticizers to be used include phthalic acid derivatives such as di-n-octyl phthalate, di-2-ethylhexyl phthalate, dibenzyl phthalate, diisodecyl phthalate, didodecyl phthalate, diisodecyl phthalate, di-n-butyl adipate, dioctyl adipate. adipic acid derivatives such as di-n-butyl maleate, citric acid derivatives such as tri-n-butyl citrate, itaconic acid derivatives such as monobutyl itaconate, oleic acid derivatives such as butyl oleate,
Others tricresyl phosphate, epoxidized soybean oil,
Examples include epoxy resin plasticizers.

Examples of the lubricant and heat stabilizer contained in the synthetic resin base material include polyethylene wax, bisamide, stearic acid, zinc stearate, barium stearate, calcium stearate, and barium ricinoleate. Examples of the ultraviolet absorber include benzotriazole-based, benzoate-based, benzophenone-based, cyanoacrylate-based, and phenylsalicylate-based ultraviolet absorbers. Examples of pigments and dyes include titanium oxide, silica, ultramarine blue, and phthalocyanine blue.

These resin additives are contained in a usual amount, for example, in a small amount of 5 parts by weight or less per 100 parts by weight of the synthetic resin base material.

In order to incorporate various resin additives such as fluorine-containing urethane compounds into the synthetic resin that serves as the base material, ordinary compounding techniques, mixing techniques,
For example, this can be done by mixing with a ribbon blender, Banbury mixer, super mixer, or other blender or mixer, and then forming the mixture into a film.

In order to form a film from synthetic resin, methods known per se,
For example, a melt extrusion method, a solution casting method, a calender method, etc. may be employed.

If the thickness of the agricultural synthetic resin covering material according to the present invention is too thin, the strength will be insufficient, which is undesirable.On the other hand, if it is too thick, it will be difficult to form a film, and the subsequent handling (cutting the film and joining it into a house shape) 0.01 to 0.5.
It is preferable to set it in the range of mm.

[Example] Below, production examples and examples of the fluorine-containing urethane compound having a polyfluoroalkyl group, a polyoxyalkylene group, and a urethane bond of the present invention are shown.

<Production Example 1> 84 g (0.5 mol) of HMDI (hexamethylene diisocyanate) and 0.63 g (0,001 mol) of dibutyltin dilaurate were placed in a 1 liter four-loaf flask and gently stirred at room temperature. While flowing dry nitrogen, add dehydrated C3Fl tc2 from a dropping funnel with a side tube.
464 g of a 50% butyl acetate solution of H30H was added dropwise over 3 hours.

After confirming by gas chromatography that the reaction rate of C, F, C2) 140H was 95% or more, 500 g (o, s mol) of polyethylene glycol 1000 was added, the temperature was raised to 60°C, and the reaction was carried out for 5 hours. . Infrared spectrum (
After confirming that the absorption of incyanate at a wave number of 2250 cm-' disappeared using IR), the solvent, butyl acetate, was distilled off under reduced pressure to obtain 790 g of a fluorine-containing urethane compound. (
Yield 97%) <Production Example 2> 88.8 g (0.4 mol) of IPDI (inphorone diisocyanate) and 05 g (0,0008 mol) of dibdeltin dilaurate were placed in a 2-liter four-loaf flask, and the mixture was homogenized at room temperature. After stirring, add the dehydrated CnFzn-+ from the dropping funnel with a side tube while flowing dry nitrogen.
50 of C2H4OH (n is a mixture of 6 to 18, average 9)
% butyl acetate solution was added dropwise over 3 hours. By gas chromatography, C,,F2. ,. , C
, 8, 0) After confirming that the reaction rate of 1 was 95% or more, 700 g of polyol with a molecular weight of 3500 was added by adding ethylene oxide and propylene oxide to 1 mole of glycerin at a ratio of 80 = 20 (weight ratio). 0.2 mol) and reacted at 60'C for 5 hours. Wave number 2 in IR
After confirming that the absorption of the isocyanate group at 250 cm-' had disappeared, the butyl acetate solvent was distilled off under reduced pressure to obtain 975 g of a fluorine-containing urethane compound. (Yield 98%) <Example> Several types of fluorine-containing urethane compounds having a polyfluoroalkyl group, a polyoxyalkylene group, and a urethane bond were produced by the method shown in the production example, and a synthetic resin film to which these were added was produced. was prepared and evaluated.

Film composition Polyvinyl chloride (degree of polymerization = 1300) 100 parts by weight Dioctyl phthalate 45 Tow cresyl phosphate 3 Ba-Zn liquid stabilizer 2 Ba-Zn powder stabilizer l Fluorine-containing urethane compound l
〃The mixture having the above composition was kneaded at 160 to 170°C, and about 1
A 50 micron thick film was made.

◇Anti-fogging evaluation In a room at 25°C, add 3 (10l) ml of 75°C warm water.
Place in a 11l beaker and seal the opening of the beaker with the film described above. Observe the surface condition of the inner surface of the film after 5 minutes have elapsed. The evaluation criteria were the following five levels.

1. Water adheres to the film surface in the form of a film.

2. There are large water droplets in some parts.

3. There are large and small water droplets, but there are also film-like parts.

4. Large and small water droplets are present, and there is no film-like part.

5. - Small water droplets adhere to the surface and the bottom of the beaker cannot be seen.

◇ Fog-proof evaluation A fog observation box with wooden boards on all sides, the water surface of an aquarium on the bottom, and a sloping ceiling covered with a test film was left on top of an aquarium with a water temperature of 40°C at a room temperature of 25°C for 48 hours. do. Water temperature 40℃
The room temperature was lowered to 5° C. while maintaining the temperature at 5° C., and after 1 hour, the state of fog generation near the film surface on the water tank side was visually observed.

The evaluation criteria were the following four levels.

A: No fog was observed at all.

B: A very small amount of fog was observed.

Generation of C1 fog is observed.

D: An extremely large amount of fog is observed.

[Effects of the Invention] The agricultural synthetic resin coating material containing the anti-fogging and dew-preventing agent according to the present invention exhibits the following remarkable effects, and its industrial utility value is extremely large.

The present invention has performance that conventional additives cannot achieve.

That is, by adding a single compound (without adding an anti-base agent for fL), it is possible to impart excellent anti-fogging and dew-proofing properties to the agricultural synthetic resin coating material.

Claims (1)

[Claims] (1) Antifogging for agricultural synthetic resin coating materials characterized by containing as an active ingredient a fluorine-containing urethane compound having a polyfluoroalkyl group, a polyoxyalkylene group, and a urethane bond represented by the following general formula [I] Anti-fog agent. ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] However, in the above general formula, , R_1 and R_2 are hydrogen atoms or methyl groups (however, R
There is no case where both _1 and R_2 are methyl groups), R_
3 is a hydrogen atom, an alkyl group, or ▲Numerical formula, chemical formula, table, etc.▼R_4 (R_4 is an alkyl group). Further, m and n, a and b, p and q are integers of 1 or more, a+b indicates the valence of the polyhydric alcohol, and p+q indicates the valence of the organic group Y. Rf represents a polyfluoroalkyl group having 1 to 20 carbon atoms.