JPS5836032B2 - 100% off - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water evaporation inhibitor characterized by mixing a long chain vinyl polymer with an aliphatic alcohol or its ethylene oxide low addition reaction product.

Conventionally known water evaporation inhibitors contain substances such as linear aliphatic alcohols, their ethylene oxide or propylene oxide low adducts, and paraffinic hydrocarbons as active ingredients, and many contain various surfactants. Alternatively, it is used as an emulsion by adding a protective colloid as an auxiliary agent.

The present inventors conducted research separately from known evaporation inhibitors and arrived at the present invention.

The present invention is directed to an ether bond in which not more than 3 moles of ethylene oxide is added to a linear saturated aliphatic alcohol having 12 to 18 carbon atoms or a linear saturated aliphatic alcohol having 16 to 22 carbon atoms, as shown in the following general formula. The present invention relates to a water evaporation inhibitor characterized in that the active ingredient is a long-chain vinyl polymer mixed at a ratio of 1/20 to 1/2.

In the general formula, R represents a straight chain saturated hydrocarbon group having 11 to 21 carbon atoms, R' represents a straight chain saturated hydrocarbon group having 12 to 22 carbon atoms, and n represents 120 to 480.

The linear saturated aliphatic alcohol having 12 to 18 carbon atoms used in the present invention is a single substance or a mixture thereof, such as lauryl alcohol, myristyl alcohol, cetyl alcohol, and stearyl alcohol.

In addition, ether bonds in which 3 moles or less of ethylene oxide are added to a straight chain saturated aliphatic alcohol having 16 to 22 carbon atoms are mono-, di- or trioxyethylenecetyl alcohol, 7-no, di- or trioxyethylene stearyl alcohol, No, di, or trioxyethylene icosanol, mono, di, or trioxyethylene docosanol, etc. may be used alone or as a mixture.

The long-chain vinyl polymers used in the present invention include polyvinyl laurate, polyvinyl myristate, polyvinyl balmitate, polyvinyl stearate, polyvinyl arachinate, polyvinyl behenate, polylauryl acrylate, polymyristyl acrylate, and polyacrylic. Cetyl acid, polystearyl acrylate, poly icosyl acrylate, poly docosyl acrylate, poly lauryl methacrylate, poly myristyl methacrylate, poly cetyl methacrylate, polystearyl methacrylate, poly icosyl methacrylate, polymethacrylate Single substance or mixture such as docosyl acrylate.

However, poly represents a polymer having an average degree of polymerization of 120 to 480.

To use the evaporation inhibitor of the present invention, first melt the pre-mixed effective amount and mix until homogeneous.
It can be cooled and pulverized to form a fine powder and then directly sprayed on the water surface, or it can be melted and mixed, emulsified into fine particles in water, and then sprayed and sprayed.

At this time, mechanical emulsification is also possible, but usually emulsification with a carbon number of 1
Surfactants such as sodium or potassium salts of straight chain saturated fatty acids having 6 to 22 carbon atoms, sodium or potassium salts of straight chain saturated aliphatic alcohol sulfates having 16 to 22 carbon atoms, or sodium or potassium salts of carboxymethyl cellulose or alginic acid. A protective colloid agent such as the following can be used as an emulsification aid and diluted to an appropriate concentration before being sprayed.

The amount of water evaporation inhibitor used in the present invention is determined based on the theoretical amount of monomolecular film formation (calculated from the area occupied by one molecule of the active ingredient necessary for forming a monomolecular film) in order to increase the durability of the thin film spread on the water surface. It is appropriate to use 10 to 100 times the amount).

The performance of the water evaporation inhibitor of the present invention will be explained with reference to the drawings. Surface pressure of the molecular film F, (Surface pressure corresponds to the difference in surface tension between the clean water surface and the water surface where the monomolecular film has spread, and is the two-dimensional pressure that causes the monomolecular film to spread further. ) and the molecular occupied area A in the monolayer
In the relationship curve (FA curve).

The evaporation inhibitor (c) of the present invention is stearyl alcohol (a
) and polyvinyl stearate (b) alone, resulting in a more densely packed condensed film with a lower compressibility and higher collapse pressure.

This indicates that the membrane has a greater effect of suppressing the permeation of water molecules and is mechanically strong, and indicates that the mixture has a synergistic effect.

Since the effect of long-chain vinyl polymer alone on suppressing evaporation is relatively low, it is practical to aim for a synergistic effect of suppressing evaporation, and to obtain a high effect on the durability of the spread film and the resilience of the spread film when it is broken. According to research by the present inventors, the mixing ratio of long chain vinyl polymer should be 1/20 to 1/20.
2 is appropriate.

The following two development methods were adopted to measure the effects of the present invention.

(1) Dissolve the sample mixed in various ratios in benzene in advance to make a developing solution with a concentration of 0.05 to 1.0 or more per 1 i of water surface. When about 100ml of the solution is dropped, the solution immediately swells and spreads, and after a few minutes, the solvent evaporates and a monomolecular film of the sample is formed.

(2) 0.05 μm of solid sample finely powdered to a diameter of 50μ or less
~0.25 g/m2 (20 to 100 times the amount required for theoretical monomolecular film formation) is sprayed on the water surface.

After 10 to 60 minutes, a monomolecular film exhibiting an effective evaporation suppressing effect is formed.

The water tank used for this measurement is a moss-shaped tank consisting of a square part and a circular part, and is melt-coated with purified paraffin.

This water tank is filled with water, and the water surface is swept with a partition plate coated with purified paraffin to keep it clean.

The surface pressure was measured using the hanging plate method in a rectangular area whose area could be changed using a partition plate, and the evaporation suppression rate was measured in a circular area.

The water tank under measurement was placed in a thermostatic chamber at a constant temperature, and was further placed in the thermostatic chamber.

The evaporation suppression rate is approximately 211% above the water surface covered with a monomolecular film.
It is calculated by comparing the weight increase due to evaporation of water of the moisture absorbent lithium chloride (placed in a circular container with a Tetron-lined bottom) suspended at the position and the weight increase at the free water surface as a control.

The evaporation suppression rate (A) is the amount of moisture evaporated from the free water surface (
B) and the amount of water evaporation from the chemically treated water surface (Q) as a percentage of the ratio of the difference between the amount of water evaporated from the water surface treated with chemicals to the amount of evaporation from the free water surface.

A2 Lower X 100 (%) Next, examples of the present invention will be described.

Example 1 Polyvinyl stearate (hereinafter referred to as P) with an average degree of polymerization of 350
vS) and cetyl alcohol (hereinafter referred to as CA).
and stearyl alcohol (hereinafter referred to as SA) in various ratios, each as a 0.20% benzene solution as described above, and i.p. per door of the water surface. oy expanded.

After benzene was evaporated and a monomolecular film was formed, the developed area was compressed using a partition plate, and the evaporation suppression rate was measured at a predetermined surface pressure, and the results shown in Tables 1 and 2 were obtained.

For example, in the columns of PVS/CA or PVS/SA ratios in Tables 1 and 2, 1:20 means 1 part PVS and 20 parts PVS.
A drug prepared by mixing CA or SA in the drug contains pv
This indicates that s is 1/21, and CA or SA is 2 0/2 1.

The same will be displayed below.

As seen in Tables 1 and 2, the evaporation suppression rate is greater when a long chain vinyl polymer such as polyvinyl stearate is used in combination to some extent than when alcohol is used alone.

In addition, the collapse pressure of the unfolded membrane in mixtures with long-chain vinyl polymers is higher than that in the case of alcohol alone, and the viscosity is also significantly higher and remarkable elasticity is observed, resulting in greater mechanical strength. It appears that the durability of the membrane and its ability to recover when it is torn have been significantly improved.

Example 2 Docosanol was charged in an autoclave, potassium hydroxide corresponding to 0.1 of the docosanol was added as a catalyst, and ethylene oxide was injected at a ratio of 1.0 mol to 1.0 mol of docosanol at 160 to 170°C. After injection, 6
The reaction was completed by maintaining the temperature for 0 minutes.

Thereafter, the reaction product was neutralized with phosphoric acid to remove the catalyst and filtered through a furnace to obtain monooxyethylene docosanol.

Monooxyethylene docosanool (hereinafter referred to as OED-1) obtained in this manner was mixed with polystearyl acrylate (hereinafter referred to as PSA) with an average degree of polymerization of 480 in various proportions as samples for measuring the evaporation inhibition rate. Example 1
The results shown in Table 3 were obtained using the same method as above.

Example 3 Based on the average molecular weight of a mixed alcohol consisting of 25 parts docosanol, 65 parts icosanol, and 10 parts stearyl alcohol, 2.0 moles of ethylene oxide was added in the manner described in Example 2 for <1.0 mole. Dioxyethylene mixed alcohol (hereinafter referred to as OEA-2) obtained by the reaction was mixed with polycetyl acrylate (hereinafter referred to as PCA) having an average degree of polymerization of 120 in various weight ratios, and each was mixed with about 80%
Melt the mixture by heating to ℃, mix uniformly, and let it cool to form a white solid, which is then ground into a fine powder.

It was spread on a clean water surface at a rate of 8011197 m2 and developed, and the results shown in Table 4 were obtained.

Example 4 A product obtained by reacting 1.0 mole of ethylene oxide with 1.0 mole based on the average molecular weight of a mixed alcohol consisting of 30 parts of docosanol, 65 parts of icosanol, and 5 parts of stearyl alcohol by the method described in Example 2. A mixture of oxyethylene mixed alcohol (hereinafter referred to as OED-3) and polystearyl methacrylate (hereinafter referred to as PSMA) having an average degree of polymerization of 500 in various proportions was treated in the same manner as in Example 3 to form a fine powder.

It was sprayed on the surface of clean water at a rate of 100 .mu./l and allowed to develop, and the surface pressure and evaporation suppression rate were measured, and the results shown in Table 5 were obtained.

The evaporation inhibitor of the present invention is used to suppress the evaporation of water in rice fields, simultaneously raise the water temperature to promote rice growth, suppress the evaporation of water in reservoirs, dams, etc. to alleviate water shortages, and suppress the drying of soil, cement, etc. .

Furthermore, it is expected to be applied to paddy rice seedlings, rapeseed, fruit trees, lumber, tobacco seedlings, etc. to suppress transpiration from the surface and prevent wilting during transplanting.

[Brief explanation of the drawing]

The drawing shows an example of the effect of the evaporation inhibitor of the present invention, which is obtained by mixing stearyl alcohol (a), polyvinyl stearate (b), and 3.4 parts, ■, and O parts of each of them. This is a relationship curve between the surface pressure F measured after spreading the evaporation inhibitor (C) as a monomolecular film on the water surface and the molecular occupied area A in the monomolecular film, and the water evaporation inhibitor of the present invention. This proves the synergistic effect of

Claims (1)

[Scope of Claims] 1. The following for an ether bond in which 3 moles or less of ethylene oxide is additionally bonded to a linear saturated aliphatic alcohol having 12 to 18 carbon atoms or a linear saturated aliphatic alcohol having 16 to 22 carbon atoms. The long chain vinyl polymer shown in the general formula is 1/
A water evaporation inhibitor characterized in that the effective precept is a mixture of 20 to 1/2. However, in the formula, R is a linear saturated hydrocarbon group having 11 to 21 carbon atoms, R' is a linear saturated hydrocarbon group having 12 to 22 carbon atoms, and n is 120 to 480.