JPS6289785A - Anti-snow melting and freezing agent - Google Patents

Abstract

PURPOSE:To provide the titled agent of great effectiveness, with little chemical hazard to plants, consisting mainly of calcium chloride, magnesium chloride and magnesium sulfate, also with its line of equal temperature rise falling in specific region. CONSTITUTION:The objective agent free from sodium chloride, consisting mainly of calcium chloride, magnesium chloride and/or magnesium sulfate, whose composition falls in such a region that the line of equal temperature rise in the figure represents >=3 deg.C. Furthermore, said agent is pref. such that the heat-developing efficiency in the figure falls in a region representing >=80%.

Description

DETAILED DESCRIPTION OF THE INVENTION (4) Fields of application of fresh produce The present invention is applicable to frozen or snow-covered roads, roofs, roads,
The present invention relates to a snow melting agent and an antifreeze agent for effectively preventing or removing snow from accumulating on farmland, etc., and in particular to a snow melting and antifreezing agent that has great snow melting and antifreezing effects and has almost no phytotoxicity to plants.

10) Conventional techniques (・shi) Snow and ice are distributed over wide areas of the earth during the winter, not only congesting traffic in the area and causing serious traffic accidents, but also making it difficult to carry out agricultural work. Particularly in areas with heavy snowfall, transportation disruptions and congestion can lead to high prices, high snow removal costs for removing snow from roads and roofs, and even traffic accidents and houses caused by snow accumulation and ice. The collapse of buildings and the loss of human life due to avalanches cause great damage both physically and mentally, and in turn impede the economic development of these regions.

As a countermeasure against the above-mentioned snow and freezing, the most widely used method is to use the FiK method to prepare crude U-scale hycalcium produced as a by-product by the Solve method (ammonia sorter method).
It is to rli, but this o It piJj,! !
Calcium chloride contains at most over 70% calcium chloride, so its anti-freezing and snow-melting effects are relatively low, and it is not effective unless it is sprayed frequently.Moreover, spraying in large quantities can cause phytotoxicity to plants and freshwater fish and shellfish. It causes For this reason, in practice, calcium chloride is only sprayed at m points on main roads, etc., but it is still applied to median strips and roadside areas (where chemical damage to trees is high).
The only way to reduce this chemical damage is to thoroughly wash the plants with water in early spring, before the grass begins to grow. Such a thing is practically impossible due to the cost of water use and other reasons. As a result, road managers are forced to spend huge amounts of money every year to replace dead trees.

The drawbacks of known snow-melting agents have been outlined above, focusing on the phytotoxicity they cause to plants, but the known snow-melting agents also have another drawback that cannot be overlooked, which is that they tend to cause rust. However, if a vehicle has been driven on a road surface coated with snow melting agents, if it is not thoroughly washed with water afterwards, the number of vehicles used will significantly decrease due to rust formation. This too.

In terms of trouble and cost, it is difficult for vehicle users! This is the cause of 8.

(c) The problem to be solved by the invention, the present invention fundamentally changes the Al composition of the conventional snow melting agent (hereinafter referred to as "snow melting agent" together with the antifreeze agent) mainly composed of calcium chloride. The main object of the present invention is to provide a novel snow-melting agent that has a large anti-freezing effect and is free from phytotoxicity to plants by improving the structure. The purpose of the present invention is to provide a snow-melting agent that does not easily cause rust on metals such as iron, is highly durable, and also helps the growth of cultivated JQ plants.

The present invention is January calcium, +1! A composition that is substantially free of food 1.11 and is composed of a compound selected from magnesium chloride and/or magnesium sulfate as a main component, and the Ml composition is as shown in Figure 1 of Appendix A1. Snow melting and c1! is characterized by being formulated in the specific 'L'i11 combination shown. Regarding anti-caking agents.

(5) Means for Solving Problem 1 The present inventor has discovered the known 11! In view of the shortcomings of calcium chloride-based snow melting agents, we conducted intensive research into improving them, and found that although calcium chloride itself has almost no negative effects on plants, the conventional calcium chloride method naturally It was confirmed that the positive heat of dissolution absorbed by this food has a harmful effect even when calculated in terms of the overall calorific value. Therefore, the heat of dissolution is approximately twice as large as that of calcium chloride. Magnesium chloride (approximately 36 kcal/mol/800-Thr20)
and the heat of solution is almost the same as U-order Hika calcium (about 20
Regarding magnesium sulfate, which has a kca of 11 mol/800 mol + 120), a two-component system Allll antipyrolysis in which both components are mixed in various proportions is performed. Inspection 8
・The heat generated when 1 mole of each component is dissolved in 800 moles of water (temporarily referred to as "theoretical calorific value") is ft1 C or less) and each component or its B? There is a large difference between the actual exothermic length when dissolved in water at 2% of the compound, and the percentage value obtained by multiplying the actual exothermic length by the theoretical calorific value by 100. (Hereafter referred to as "heat generation efficiency")
discovered that the proportions of each component vary over a considerable range.

Figure 1 plots the upper A temperature (difference between the water temperature before dissolution and the highest water temperature after dissolution) of the water temperature by mixing the above three components in various proportions, and the one isothermal upper A line (isothermal Fig. 2 is a similar graph showing the heat generation efficiency at each plot point in Fig. 1. According to these, it is inferred that the following tendency exists. 1 or can be confirmed.

■ The height of the temperature rise generally depends on the blending ratio of magnesium chloride (see Figure fli1).

■ However, the 1st isotherm is not necessarily proportional to the amount of magnesium chloride, and varies in the range of 10 to 20% of the amount (11th, the difference in the content of magnesium chloride is 10 to 2%)
Even if the temperature fluctuates by 0%, similar heat generation may occur. ) (ibid.), especially as the proportion of magnesium sulfate increases, the heat of solution increases.

■ As the content of magnesium chloride increases, the exothermic efficiency tends to decrease (see Figure 2).

■ Heat generation efficiency is 80% or more and temperature rise is 3°5℃
A suitable Ml composition that exceeds magnesium chloride and il
It is found in the area mainly composed of magnesium chloride, and 11! (If the amount of hicalcium exceeds half L1 of the total Ml composition, both the exothermic efficiency and the temperature increase tend to decrease (see Figures 1 and 2, 1111).

■ A preferable range with a good balance in both heat generation efficiency and upper temperature is approximately 20 to 40% calcium chloride, 30 to 50% magnesium chloride, and 20 to 20% magnesium sulfate.
Found in a ternary system consisting of 50% (total 100%) (
).

■ If only the exothermic efficiency is considered, a highly efficient Ml composition exists in a region containing calcium chloride or calcium sulfate alone or mainly composed of calcium chloride or calcium sulfate (tl'L2
Figure #ilr, 1. ).

(2) In order for the upper H temperature to exceed 3°C, it is necessary to use a two-component system in which magnesium chloride is blended with at least calcium chloride or magnesium sulfate (see IT diagram).

The present invention is based on the above findings.

(Specific Structure of the Invention) Therefore, the present inventors have proceeded to develop compositions mainly containing the various above-mentioned salts shown in Tables 1 and 2.

Daikon radish seedlings as test 44 $4 these 1! ! As a result of investigating the effects on plants such as
'lA), 11! Even if magnesium chloride or magnesium sulfate is mixed with calcium chloride, there is little effect on plants (trials $lC, F, G, Fuki 1.J).

N, O, P, P-2, Q, n), especially advance loans, are suitable B1.
In this case, we found that it actually has the effect of promoting plant growth (tests $I J and N).The present inventor further investigated the effects of potassium chloride and phosphates in the coexistence with magnesium chloride and magnesium sulfate. The latter has the effect of promoting plant growth (sample 0), and the latter has the effect of significantly suppressing rust caused by calcium chloride and potassium chloride, as shown in Table 4. I discovered that.

The present invention is based on the above findings + 7, and uses calcium chloride.

An M1 composition free of magnesium chloride and magnesium sulfate, characterized in that the composition is given a composition whose isothermal rise line in the attached Figure 1 belongs to a region of 3°C or higher. , 1J! Preferably, the composition of the snow melting agent includes soluble potassium salts and/or phosphates as optional auxiliary ingredients.

Food +1 for real quality! Calcium 441, which does not contain 1, is found in limestone, which is abundant throughout the world, and 1! It can be easily produced using engineered acid as the original material according to the chemical equation below.

CaCO2" 21 [1-CaCl2 + 1120
+ CO2↑According to the above formula, U-order hycalcium should theoretically be obtained in the form of a -hydrate salt, but in reality, due to the large amount of water coexisting with hydrochloric acid, it is obtained in the form of a polyhydrate such as a hexahydrate salt. Obtained in salt form. Therefore, in order to use it in the present invention, it is necessary to heat and dehydrate it, preferably to an anhydrous state, or at most to the level of dihydrate. In the case of hexahydrate, it becomes more endothermic when dissolved)fp +; -1-r;;
喰／Th ln ding (1; '!!+l+ MH
l lik ++f Fusuma Jll-'s small 14 impurities, such as iron, magnesium, aluminum, etc. are 11! They elute in the form of compounds, but the presence of these impurities
There is no problem in practical use.

Substantially non-edible magnesium sulfate can be obtained in the laboratory by dissolving metallic magnesium in sulfuric acid, but it can be obtained industrially by dissolving magnesium metal in sulfuric acid. (MgS
O4 71120) or as a by-product of the rock salt industry 11)
Kieserite (MgSO4,1+120) is red hot.

It can be produced economically by dehydration. However, since Kieserei itself generates a considerable amount of heat of melting, it can be used as a substitute for unmanned cars in practical terms. Incidentally, even when natural Kainai (KCI.Mg5Oa.31120) is heated and dehydrated, it can be obtained in the form of a mixture with potassium chloride, which can also be advantageously used as a component of the composition of the present invention.

Magnesium 11X (anhydrous u-technique), which is one of the main components in the snow melting agent of the present invention, generates about 36 kcal of heat of dissolution when 1 mole thereof is dissolved in 800 moles of water.

Magnesium sulfate, another main component, has a strong exothermic value of 1 ba (approximately 2'0 kca 11 mol) and 1. As mentioned above, Li has the effect of promoting plant growth. Furthermore, calcium j43, which is one of the main components (
)! Water I! 1) generates a heat of solution of about 18 kcal when 1 mole of it is dissolved in 800 moles of water, and its mixture with snow or ice does not freeze up to -45°C, and this product is 11! Calcium chloride increases the exothermic efficiency when present in a ratio of 1:11 in the total Allium composition. Therefore, in the present invention, it is preferable to use magnesium chloride, magnesium sulfate, and/or calcium chloride as a major component, and to add soluble potassium salts and/or phosphates as minor components or auxiliary components. Examples of phosphates include sulfuric acid salts such as potassium phosphate, potassium hydrogen phosphate, sodium phosphate, and sodium hydrogen phosphate, as well as alkali metals such as metaphosphoric acid, pyrophosphoric acid, trimetaphosphoric acid, and polyphosphoric acid.
H; and soluble potassium ILs, for example, 4
! Examples include potassium dioxide, potassium sulfate, potassium nitrate, etc., but are of course not limited to these. Furthermore, the above potassium phosphoric acid j! Type 1 naturally also serves as soluble potassium jL.

The blending ratio of each of the above components can vary widely depending on the purpose. However, as is clear from Figures 1 and 2, it seems that the actual usage conditions are close (however, assuming the specific gravity of snow as 0.1) as a 2% solution, the magnesium chloride content is the same < 20% or more 65 % or less, magnesium sulfate is 2
The region of 0% to 50% and half or less of the calcium chloride Ml composition, especially the shaded region in the attached Figure 2, seems to be optimal in terms of the balance between main temperature and heat generation efficiency. It looks like. Of course, frL area A in the same figure.

As B and C, there are preferable points in areas outside of the second preferable conditions, so which composition to adopt in practice depends on the price of raw materials, ease of acquisition, and other related products. balance of,
It should be determined in consideration of various factors such as the amount of heat generated and the effect on plants and rust. However, if the vinegar content of magnesium 13ide and magnesium sulfate is too high, there is a risk of phytotoxicity to plants and the antifreeze effect will decrease, as well as phosphorus. ! Since it is difficult to prevent rust even if using similar substances, in practice, each component is increased or decreased within a range of ±10% based on a mixture of approximately equal amounts of magnesium chloride, magnesium sulfate, and calcium chloride. would be suitable.

Phosphoric acids, especially alkali metal salts of phosphoric acid, have the effect of improving acidic soil through their buffering action, and at the same time work to weaken the soil acidification effect of the main ingredient, magnesium sulfate. In addition, phosphates are useful components for road snow melting agents because they suppress the rusting of vehicles due to their antirust action.Suitable phosphates The amount of is preferably about 5% of the total composition for agricultural use, but since it causes eutrophication of water quality, for general use or roads, it is preferable to use an amount of 1, for example 2%, sufficient to prevent fA. should be kept in small amounts.

Soluble potassium Ii! Class 1 For example, potassium chloride.

Although it may be present in an amount of 10% or more in the total composition, since it absorbs heat when dissolved in water, its presence in large quantities deteriorates the original performance of the snow melting agent. Therefore, one ingredient is 5% of the total composition.
% or less.

Iron salts should be added to old water that has been reduced to less than 1% of the total amount, unless added for a special purpose such as replenishing iron to prevent yellowing disease. No.1
Il is sufficient.

Other trace elements necessary for plant growth 1. For example, copper.

However, manganese, zinc, boron, etc. may also be added in small amounts in a soluble form such as copper sulfate, bunganese chloride, zinc chloride, boric acid or borax, if necessary.

These trace elements are universally present in trace amounts required by 1 gram of plants in the soil, so they do not necessarily have to be included in this snow melting agent. The trace elements do not absolutely have to be added as water-soluble salts, but even if they are insoluble in water, such as dibasic or cupric hydroxide, they may be added with chelators such as ethylenediaminetetraacetic acid. - Substance or metaphosphoric acid U! Like 2n 11! It can be solubilized by the coexistence of forming molecules.

In addition to the above ingredients, auxiliary ingredients include nitric acid, ammonium j1! Examples include ammonium lf, ureido, cyanamide, ammonium sulfate, ammonium chloride, calcium cyanamide, and urea. These compounds are used in fertilizers as nitrogen sources for plants.
Because of its effectiveness, it is useful as an auxiliary ingredient in snow-melting agents for farmland.

In addition to the above components, reactive components such as aluminum chloride, lime, and iron powder may also be added as desired.

These components are useful components as they react with oxygen or water and generate a large amount of heat of reaction, but they also react with water to generate hydrochloric acid like aluminum chloride, or leave a white residue like lime. Its disadvantage is that it creates things. However, 1! due to aluminum chloride! ! The generation of acids can be prevented by adding lime, and the formation of residues (calcium hydroxide) due to lime can also be prevented.

Soluble potassium j1! 31! Combines with magnesium chloride hexahydrate to form the mineral carnalite. The roasted product is a mixture of magnesium chloride and potassium chloride rum, which contains a considerable amount of magnesia.
If the amount is small enough not to form magnesia cement,
It may also be added to the Mt composition.

The composition according to the present invention may further contain inexpensive radiant heat absorbers such as coal shell powder, smoky charcoal powder, charcoal powder, various pigments or face paints, etc., if desired. These colored granules allow sprayers to visually measure the amount of spraying and average the amount of spraying, and also have the advantage of absorbing far more radiant heat than white granules alone, promoting the melting of remaining snow. Examples of typical inorganic pigments include moxibustion lead, zinc yellow, cadmium yellow, navel yellow, euchi (more yellow), Bengara, red lead, cadmium red, vermilion (more red), Mars purple. , Nuremberg purple, cobalt purple (more than purple (more than blue), chromium green, chromium oxide, cobalt violet, peacock powder (more than green), etc., and many organic dyes such as auramine, Persian orange, niosin, rhodamine, Methyl violet, malachite green, Victoria
Dye substances such as blue can also be used as water-soluble colorants as they are, or can be used as insoluble colorants by forming lakes.In the present invention, these pigments or dyes can be freely selected depending on the purpose. However, due to toxicity and carcinogenicity considerations, it is wise to avoid toxic heavy metals such as lead and cadmium, and azo dyes.

The composition according to the present invention may be in crystalline or powdered form, but
Granular compositions are preferable in order to increase sustainability. Although granular compositions are somewhat inferior in immediate effect, they are persistent, so if sprayed before snowfall or freezing, it will last for a long time. '4A Prevent snow or ice. In other words, when this granular snow-melting agent is sprayed on a snow-covered or frozen surface, it melts and generates heat and sinks into the snow or water, but since the specific heat of snow and ice is small, the amount of heat is conserved and it lasts for a long time. It has a snow-melting or ice-melting effect. The size of the granules is usually selected from a range of 1 to 8 mm in diameter, but a mixture of various particle sizes with different average particle sizes is particularly suitable as a product that has both immediate and long-lasting properties. Become.

On the other hand, flake-like products with a thickness of about 0.5 to 2 cm can be used for 1M roots, slopes, etc. It is suitable for application to slopes and is much more durable than simple powder or crystalline products.

A small amount of binder (sizing agent) may be added to the above granular or flaky Ut composition as necessary. The binder is preferably an inexpensive material such as starch paste, soybean whey or milk whey elite, sulfite valve waste liquid, hydroxyethyl cellulose, methyl cellulose, blackstrap molasses or dextrin. The amount of water should be kept as small as possible to avoid hydrochlorination of the ingredients. In addition, when shaping water-reactive components such as aluminum chloride or lime into granules or flakes, a 41 solvent-soluble sizing agent such as methyl cellulose with a degree of methoxylation of 38 to 43% is used. The use of this non-aqueous solvent is also recommended during general granulation in order to avoid water content.

1 e) Example scrap marble and 1! ! Calcium chloride made from acid 2
00g (1st class reagent, same below), Magnesium chloride 4
00g, magnesium sulfate 400g, potassium chloride 5θg, sodium hydrogen phosphate 25g, 13
Add 5 g of ferrous tetrahydride and Ig of malachite green lake, and pulverize thoroughly using a small trommel in dry air.
Mixed.

The above mixed powder was placed in a small onion-shaped granule making machine, and a total amount of 2201 5z hydroxyethyl cellulose solution was gradually added dropwise while blowing dry warm air, while rotating and drying to obtain a granular product of 1050 g. ft(lta.

Then, the mixed granules obtained as described above are mixed with l+am
The mixture was sieved using 6 sieves of 5a+m to obtain 1000 g of a mixed granular product having a diameter of 1II11 or more and 5 mm. This product is a beautiful green granule that has more than twice the calorific value compared to conventional calcium chloride-based snow melting agents, is easy to measure and handle as it is, and has both immediate and delayed effects. It is a snow melting agent with excellent pyrotoxicity, but by further classifying it, it can be made into particles with an appropriate particle size depending on the purpose.

Incidentally, one or more of the products are unsuitable for application to farmland or fields immediately before sowing, but they have a remarkable growth promoting effect on young seedlings once they have germinated, especially on the stems of seedlings. It is characterized by a marked increase in diameter. Therefore, as a snow melting agent for fields of wintering crops such as wheat, it has a remarkable effect as a fertilizer. Furthermore, it is an excellent long-lasting snow melting agent for roads that does not cause any danger of killing planted trees or rusting vehicles.

As explained above, the present invention has important significance in the public interest in that it can be used for snow melting and antifreeze protection.

[Brief explanation of drawings]

Figure 1 is a triangular graph showing the rise in water temperature when a ternary MIJ compound consisting of magnesium 111 oxide, magnesium sulfate, and calcium chloride is dissolved in water at a rate of 2%.
FIG. 2 is a triangular graph showing the heat generation efficiency (actual temperature increase/theoretical temperature increase x 100%) at each of the thirteenth measurement points.

Claims (7)

[Claims] (1) A composition containing salts selected from calcium chloride, magnesium chloride, and magnesium sulfate as a main component and substantially free of common salt, and the composition has a temperature rise line in the attached Figure 1. A snow melting and antifreezing agent, characterized in that it has a composition that belongs to a temperature range of 3°C or higher. (2) The agent belongs to the region where the isothermal rise line in attached Figure 1 is 3°C or higher, and the exothermic efficiency in attached Figure 2 is 80%.
A snow melting and antifreezing agent according to claim 1, which has a composition falling within the above range. (3) The snow melting and antifreezing agent according to claim 1 or 2, wherein the agent contains phosphates and/or soluble potassium salts as an auxiliary component. (4) Claim 1 in which the agent is in the form of granules or tablets
The snow melting and antifreezing agent according to any one of Items 3 to 3. (5) The snow melting and antifreezing agent according to claim 4, wherein the agent is a mixture of several types of granules or tablets having different average particle sizes. (6) The snow melting and antifreezing agent according to any one of claims 1 to 3, wherein the agent is in the form of flakes. (7) The snow melting and antifreezing agent according to any one of claims 1 to 6, wherein the agent is colored.