JPH02202574A - Anti-freezing agent - Google Patents

Abstract

PURPOSE:To provide an anti-freezing agent having an excellent anti-freezing effect, an improved metal corrosion-preventing property and an improved harmless property for plants and human bodies, comprising an inorganic acid alkali(ne earth) metal salt, etc., and methylglucoside. CONSTITUTION:The objective anti-freezing agent comprises (A) at least one selected from a group comprising inorganic acid alkali(ne earth) salts (preferably sodium chloride), alkaline earth metal salts and ammonium salts and (B) methylglucoside. The agent further contains preferably adipic acid, glutaric acid or benzoic acid.

Description

[Detailed description of the invention] [Industrial application field] TECHNICAL FIELD The present invention relates to an antifreeze agent used for road surfaces and the like.

More specifically, the present invention relates to a novel antifreeze agent that prevents metal corrosion and improves phytotoxicity to animals and plants.

[Conventional technology]

Conventionally, various measures have been considered to prevent road surfaces from freezing, but one method is generally to spray antifreeze agents whose main ingredients are salts of inorganic acids such as calcium chloride and sodium chloride. ing. However, such conventional anti-freeze agents have the disadvantage that they are highly corrosive to metal parts of automobiles and the like, cause damping of plants, and are harmful to humans and animals. Therefore, in conventional products, it was necessary to mix phosphoric acid-based or amine-based rust preventive agents in order to reduce metal corrosion.

Furthermore, various methods have been proposed to improve the above-mentioned antifreeze agents. For example, JP-A-48-6848
Publication No. 1 discloses that corrosion of metal parts of automobiles and the like and phytotoxicity to animals and plants can be reduced by using an antifreeze agent containing urea and an ammonium salt of an inorganic acid. Furthermore, JP-A-62-89785 discloses that the composition is composed mainly of salts selected from calcium chloride, magnesium chloride, and magnesium sulfate, is substantially free of salt, and has an isothermal rise line of 3°C or more. A snow melting and antifreezing agent with a specific composition belonging to this patent is disclosed, and it is described that it has a large snow melting and antifreezing effect, and can almost eliminate phytotoxicity to plants.

[Problem to be solved by the invention]

However, the previously proposed antifreeze agents mentioned above cannot be said to have a sufficiently satisfactory improvement effect on metal corrosion in automobiles, etc. and chemical damage to animals and plants, and furthermore, there are no excellent improvement effects on such adverse effects. It is hoped that an antifreeze agent will emerge that has the following properties.

The purpose of the present invention is to solve the above-mentioned problems in the prior art, and to provide an antifreeze agent with excellent effects that improves corrosion of metals such as automobiles on roads and chemical damage to plants and animals. It's about making suggestions.

[Means to solve the problem]

As a result of intensive research into the above-mentioned problems with antifreeze agents, the present inventors have developed a new antifreeze agent that has excellent antifreeze effects and is also effective in preventing metal corrosion and chemical damage to animals and plants. The present inventors have discovered that it can be obtained with a specific composition, and have completed the present invention.

That is, the present invention is an antifreeze agent comprising (A) at least one salt selected from the group consisting of alkali metal salts, alkaline earth metal salts, and ammonium salts of inorganic acids, and (B) methyl glucoside.

Hereinafter, the antifreeze agent according to the present invention will be specifically explained.

Specific examples of the alkali metal salt of an inorganic acid used as a component of the antifreeze agent according to the present invention include sodium chloride (rock salt), potassium chloride, sodium sulfate, and sodium phosphate. As alkaline earth metal salts,
Examples include calcium chloride and magnesium chloride. Further, as the ammonium salt of an inorganic acid, for example, ammonium sulfate, ammonium nitrate, etc. are used.

As the antifreeze agent according to the present invention, one kind selected from the above-mentioned alkali metal salts, alkaline earth metal salts, and ammonium salts of inorganic acids can be used alone or in combination of two or more kinds.

However, if the above-mentioned salts of inorganic acids are used as antifreeze agents, problems such as corrosion of metals such as automobiles and chemical damage to animals and plants will inevitably occur. It is known that this problem is especially serious when an antifreeze agent containing calcium chloride is used.

In order to solve the above problems, the antifreeze agent according to the present invention is characterized by using methyl glucoside as a main component. Methyl glucoside is produced from corn starch or the like as a raw material, so it is highly safe as it is not corrosive to metals or harmful to animals or plants. In particular, calcium chloride contained in conventional anti-freeze agents is known to cause metal corrosion and significant phytotoxicity to animals and plants, but by using calcium chloride and methyl glucoside together as in the anti-freeze agent of the present invention, Such salt damage can be improved.

Methyl glucoside has two types of optical isomers, α and β, and is usually produced as a mixture of the two, but any content ratio can be used. Furthermore, the solubility of methyl glucoside in water is 100 g or more per 100 g of water, so it dissolves well. therefore,
It also has excellent solubility and fast-acting properties, which are necessary properties as an antifreeze agent.

Regarding the antifreeze effect of methyl glucoside, for example, the content of methyl glucoside required to lower the freezing temperature to -5"C by dissolving methyl glucoside in water, that is, the concentration of the aqueous solution is 8% (by weight), and this value is This shows that it has a very superior antifreeze effect compared to sodium chloride 8% (weight) and calcium chloride 6.7% (weight).

The mixing ratio of inorganic acid salts and methyl glucoside used in the antifreeze agent according to the present invention is expressed in weight%, and is usually 20% by weight.
It is in the range of ~25775-78.

This value indicates that if the amount of inorganic acid salts exceeds the above range, metal corrosion and phytotoxicity to animals and plants will increase, while if the proportion of methyl glucoside increases, metal corrosion and phytotoxicity will decrease, but the antifreeze effect will decrease slightly.

In the antifreeze agent according to the present invention, it is preferable to add and mix at least one of adipic acid and glutaric acid as a subcomponent in order to prevent metal corrosion.
The amount of adipic acid used is usually 0.4 to 0.4 to the total amount of ingredients.
0.6% by weight, and glutaric acid preferably in the range of 0.8 to 1.0% by weight. Furthermore, it is desirable to use benzoic acid as a stabilizer for the antifreeze agent of the present invention in a range of usually 0.2 to 0.4% by weight based on the total amount of components. Other additives commonly used in antifreeze agents can also be used in combination, if necessary. For example, radiant heat absorbers such as coal shell powder and charcoal powder, various inorganic and organic colorants, etc. can be used.

The antifreeze agent according to the present invention is prepared by mixing the above-mentioned components, that is, inorganic acid salts, methyl glucoside, adipic acid, glutaric acid, benzoic acid, and other additives using a conventionally known mixer such as a blender or tumbler. Manufactured.

The obtained mixture can be used as it is as powder or granules, but depending on the purpose of use, the mixed powder or granules may be molded into granules using a press molding machine or the like. Such a granular antifreeze agent is easy to handle and can be used as a preferable product depending on the application, as the antifreeze effect is more durable. It can also be used as an aqueous solution with an appropriate concentration depending on the purpose.

As described above, the antifreeze agent of the present invention has an excellent antifreeze effect by containing methyl glucoside produced from corn starch as a main ingredient, and has no corrosion of metals or chemical harm to humans, animals, or plants, and has been previously used. It is particularly safe compared to other antifreeze agents. In particular, calcium chloride used in conventional anti-freeze agents is problematic in that it is corrosive to metals and highly harmful to animals and plants. It is possible to reduce salt damage and produce an excellent antifreeze agent.

Therefore, the antifreeze agent according to the present invention can be safely used as a snow melting agent and an antifreeze agent in a wide range of places such as roads, general workplaces, farms, and homesteads.

〔effect〕

Since the antifreeze agent according to the present invention uses methyl glucoside as the main component, it has an excellent antifreeze effect and
It has particularly excellent characteristics in terms of safety, such as no metal corrosiveness and no phytotoxicity to humans, animals, or plants. Therefore, it has many practical advantages, such as being usable in a wide range of locations and being easy to store, transport, and handle.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 25 g sodium chloride, 73 g methyl glucoside, 0.6 g adipic acid, 1.0 g glutaric acid and 0 benzoic acid.
．． 4 g was uniformly mixed for about 15 minutes using a Henschel mixer to obtain the mixture of the present invention. The following tests were conducted using this mixture.

Melting Water Amount Test 2501 d of tap water was placed in a 500 series hollow beaker and left in a -5°C freezer for 24 hours to form ice. Next, the above mixture 20 at a temperature of 0°C is placed on the water surface.
g was evenly dispersed and then left in a -5°C freezer. After a predetermined period of time after spraying, the beaker was taken out and the weight of the liquid produced when the ice melted was measured. Each measurement was the average of three tests. The results are shown in Table 1.

Corrosion Test A 3% aqueous solution of the above mixture was prepared, and a steel SS41 test piece was immersed in this aqueous solution and left in a constant temperature room at 20°C. This test piece was immersed for one day, then taken out and left at room temperature for one day, and the cycle was continued. After 7 days, the weight change of the test piece taken out was measured to determine the corrosion rate (mdd). The results are shown in Table 2.

Plant test A 35% aqueous solution of the above mixture was prepared, and this aqueous solution was sprayed using a watering can on each of the growing daikon radish, daikon radish, and spinach twice a day for 4 days, and changes in condition were observed. did. The results are shown in Table 3.

Hazardous Substance Test Using a 35% aqueous solution of the above mixture, the content of harmful substances to human health was measured according to the JIS KOIO2 test method. Examples 2 to 4 The results are shown in Table 4 In Example 1, calcium chloride (Example 2) and a mixture of calcium chloride and magnesium chloride (mixing weight ratio 50:50) (Example 3) were used instead of sodium chloride. ) or ammonium sulfate (Example 4), the melt water amount test, corrosion test, and plant test were conducted in the same manner as in Example 1. The respective results are shown in Tables 1, 2 and 3.

Comparative Example 1 Corrosion test, plant test, and harmful substance M were carried out in the same manner as in Example 1, except that only sodium chloride, a conventional antifreeze agent, was used instead of the mixture of sodium chloride and methyl glucoside. The test was conducted. The results are shown in Tables 2, 3 and 4, respectively.

Comparative Examples 2 to 5 In Comparative Example 1, calcium chloride (Comparative Example 2), a mixture of calcium chloride and magnesium chloride (mixing weight ratio 50:50 (Comparative Example 3), or ammonium sulfate (Comparative Example 4)) was used instead of sodium chloride. A corrosion test and a plant test were carried out in the same manner as in Comparative Example 1 except that the following was used.

Further, a similar corrosion test was conducted using only tap water (Comparative Example 5).

The results are shown in Tables 2 and 3.

Table 1: Melt water volume test, where mdd is 1 drrr of the test piece, a unit of corrosion rate that indicates the amount of weight change in mg per day.

Table 3 Plant test However, the unit of melt water value is duram (g) Table 2 Corrosion test However, the evaluation criteria is ○...no abnormality Δ...partial abnormality x...overall Abnormal Occurrence Table 4 Hazardous Substance Test The above results show that the antifreeze agent of the present invention has excellent antifreeze effect, and is superior to conventional products in preventing metal corrosion and being harmless to plants and the human body. It can be seen that it has excellent characteristics.

Claims (1)

[Scope of Claims] 1) An antifreeze agent consisting of (A) at least one salt selected from the group consisting of alkali metal salts, alkaline earth metal salts, and ammonium salts of inorganic acids, and (B) methyl glucoside 2) The antifreeze agent according to claim 1, characterized in that it contains at least sodium chloride as the alkali metal salt of an inorganic acid. 3) The antifreeze agent according to claim 1 or 2, which contains at least one selected from the group of adipic acid, glutaric acid, and benzoic acid.