CS252686B1 - Ice and snow removal agent with long-lasting de-icing and inhibitory effect - Google Patents

Abstract

The solution relates to a preparation for removing frost, ice and snow with a long-term deicing and inhibiting effect. Its essence lies in the fact that it contains compounds from the group of aliphatic polyhydric alcohols in 60 to 95 parts by weight, an additive for adjusting physical-mechanical and chemical properties in an amount of 1 to 20 parts by weight, optionally supplemented with an additive of surfactants up to 0.3 parts by weight, thickeners up to 1 part by weight, inhibitors up to 0.1 part by weight and a solvent in an amount of 4 to 39 parts by weight.

Description

The invention relates to a preparation for removing and preventive protection against icing of vehicles and equipment in demanding conditions, especially in aviation operations.

De-icing agents are substances or mixtures of substances, or their concentrated solutions, which form mixtures with frost, snow or ice with a freezing point significantly lower than the freezing point of water, usually releasing certain amounts of thermal energy.

By sprinkling solid salts or spraying concentrated solutions, it is possible to achieve quick and labor-saving removal of snow, ice and frost from the treated surfaces. The appropriate type of deicing agent is also selected depending on the type of equipment. Effective and economically favorable agents based on inorganic salts of mineral acids (mainly chlorides of alkali metals or corrosive earth metals) are, despite high additions of inhibitory additives, only suitable for sprinkling roads.

Their intense effect on the corrosion of light metals does not allow this type to be used for aviation technology or airport surfaces, and they are not desirable from an environmental point of view.

Among the more accessible substances of organic origin, urea is recommended, for example. ČS A.O.

184 118 describes a liquid deicing agent for airport surfaces with a composition of 25% urea, % ethyl alcohol, 0.4% zinc fluoride, 0.1% sodium hexamethyl phosphate and 49.5% water. This type is also not recommended for direct application to delicate mechanics, as it is very aggressive to magnesium alloys.

Another group of substances for the formulation of deicing fluids are aliphatic monohydric alcohols. They are characterized by minimal hygiene of harmfulness, fast and reliable function. The disadvantage of these substances is a relatively short-term effect, which is given by their higher evaporation rate, and an unfavorable assessment from the point of view of fire safety, since they are liquids of the I. flammability class.

The last type - the most widely used in aviation practice - are deicing additives based on polyhydric aliphatic alcohols, such as ethylene glycol, propylene glycol and their polymers. They represent a certain balanced compromise between the decisive evaluation criteria - i.e. functional efficiency, availability of raw materials, environmental impact, fire safety aspects and low corrosion effect on the materials of the treated equipment. Current preparations of this type are complex systems containing, in addition to the carrier functional compound, a whole range of additives affecting the physical and mechanical properties of the protective film of the deicing agent, such as thickness, viscosity, surface tension and the like.

An illustrative example can be the Austrian patent OE 314 702, which is a protected mixture consisting of 50 to 90% ethylene or propylene glycol or glycerin, 10 to 50% water, 0.1 to 1% polyethylene glycol ether diisoalkylphenol, 0.5 to 5% copolymers of acrylic or methacrylic acid with alkyl esters of these acids and a corrosion inhibitor. Such mixtures respect almost all the requirements imposed on deicing fluids. A certain disadvantage can be the problem of corrosion inhibition, since additives for adjusting physical and mechanical properties can adversely affect the aggressiveness of the preparation, at least for some construction materials, especially light metals and paints.

Given that current aircraft equipment is constructed from a variety of completely diverse materials, including primarily light alloys of aluminum and magnesium with special surface treatments, as well as steel, non-ferrous metals, protective galvanically deposited layers of zinc and cadmium, various types of paints, synthetic materials and sealing materials, the selection of inhibitor additives that would reliably protect such a wide range of materials without stimulating any type of corrosion is quite challenging. Usually, a mixture of several types of inhibitors is proposed for this purpose, the selection of which must be the result of extensive long-term experiments in the interest of the safety of the operation of the treated equipment, not only in the working concentration preparation but also in significantly more diluted solutions, since the concentration of active substances is greatly reduced when the preparation is applied to ice or when operating under adverse weather conditions.

The above disadvantages of the necessity of a complex selection of effective inhibitory additives for such unfavorable conditions during application are eliminated by the preparation according to the invention, the essence of which lies in the fact that it contains an additive for adjusting the physical-mechanical properties and chemical properties of the preparation in an amount of 1 to 20 parts by weight of alkali metal salts of aliphatic mono- or polycarboxylic acids with a number of carbon atoms of 10 to 30, preferably potassium salt of abietic acid contained in natural rosin, mono- or polyterpenic carboxylic acids with alkali metals or with alkaline amines or with alkanolamines, or mixtures of these substances.

The advantages of thickening surfactants with anti-corrosion effects can be further enhanced by significantly smaller proportions of substances used for this purpose, e.g. carboxymethyl cellulose, polyvinyl alcohol, copolymers of acids with acrylic acid esters, common surfactants of the non-ionic type, e.g. alkyl polyglycol ether alcohols, alkyl polyglycol ether phenols, copolymers of ethylene oxide and propylene oxide, or inorganic corrosion inhibitors based on combinations of phosphorus and silicon, or organic substances from the group of aliphatic amines, nitrogen heterocycles or their benzo- or naphtho-derivatives, e.g. 2-hydroxybenzotriazole. The composition of the preparation can be further adjusted as necessary with suitable solvents, e.g. aliphatic monohydric alcohols, water or mixtures of these substances.

The basic idea of the new solution is to use such additives to the usual functional components, i.e. aliphatic polyhydric alcohols, which would combine in their function both a thickening additive to achieve a longer-lasting deicing effect, and the function of a surfactant for more perfect wetting of the treated surface, and at the same time the function of an anti-corrosion inhibitor, sufficiently effective in wide concentration limits for all used equipment materials.

The preparation according to the invention shows several times longer functional efficiency (2 to 7 times) and at the same time reduced aggressiveness towards the most sensitive materials - compared to existing products reduced by 40 to 220%. Thanks to the higher content of the polyfunctional additive even in diluted solutions, it guarantees sufficient anti-corrosion protection of all materials.

>example of implementation to l/a-d· í % wt diethylene glycol 88 potassium stearate 4 ethyl alcohol 3 octadecylamine 0.05 water to 100 k 1 and d 2 % wt monopropylene glycol 75 potassium salt of abietic acid 0.25 water to 100 : k 1 and d 3 % wt monoethylene glycol 73.4 dihydroxyabietic acid potassium salt 2.5 cetyl octadecyl glycol ether alcohol 0.1 sodium stearate 2 water to 100

Example 4 wt.%

triethylene glycol 66 sodium sebacate 7 'sodium methacrylate 1 sodium silicate 0.1

2-hydroxybenztriazole 0.05 water to 100% wt.

Example 5* glycerin 77.3 triethanolamine salt of abietic acid 11 carboxylmethylcellulose 0.5 sodium pyrophosphate 0.2 water to 100

Claims (4)

SUBJECT OF THE INVENTION 1. Long-term de-icing, ice-and-snow-removing agent based on aliphatic polyhydric alcohols in an amount of 60 to 95 parts by weight and a solvent from the group of aliphatic monovalent alcohols, for example ethyl alcohol, water or a mixture thereof by containing in an amount of 1 to 20 parts by weight of an alkali metal salt of an aliphatic mono- or polycarboxylic acid having a carbon number of 10 to 30, for example a potassium salt of an acid contained in natural rosin, and / or an alkali metal mono- or polyterpenic carboxylic acid; with alkali amines or alkanolamines, for example sodium lauryl, or mixtures thereof. 2. A composition according to claim 1 comprising up to 1 wt. % of a supplementary thickening agent, e.g. soluble cellulose derivatives, preferably carboxymethylcellulose, or polymers of unsaturated aliphatic alcohols, e.g. polyvinyl alcohol, or soluble derivatives of acrylic acid or mixtures thereof. 3. A composition according to claim 1 and / or 2, characterized in that it contains up to 0.3 wt. % of a surfactant such as non-ingenic alkyl polyglycol ether alcohol type alcohols, alkyl polyglycol ether phenols or ethylene oxide-propylene oxide copolymers such as cetyl decaloglycol ether phenol. 4. A composition according to claim 1 and / or 2 and / or 3, characterized in that it contains up to 0.1 wt. Inhibitors such as phosphorus compounds such as sodium pyrophosphate, silicon compounds such as sodium silicate, aliphatic amines such as hexadecylamine, or nitrogen heterocycles and their benzo- or naphtho-derivatives.