CA2130649A1 - De-icing and anti-freezing composition - Google Patents
De-icing and anti-freezing compositionInfo
- Publication number
- CA2130649A1 CA2130649A1 CA002130649A CA2130649A CA2130649A1 CA 2130649 A1 CA2130649 A1 CA 2130649A1 CA 002130649 A CA002130649 A CA 002130649A CA 2130649 A CA2130649 A CA 2130649A CA 2130649 A1 CA2130649 A1 CA 2130649A1
- Authority
- CA
- Canada
- Prior art keywords
- composition
- icing
- alkali metal
- composition according
- ice
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K3/00—Materials not provided for elsewhere
- C09K3/18—Materials not provided for elsewhere for application to surfaces to minimize adherence of ice, mist or water thereto; Thawing or antifreeze materials for application to surfaces
- C09K3/185—Thawing materials
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K3/00—Materials not provided for elsewhere
- C09K3/18—Materials not provided for elsewhere for application to surfaces to minimize adherence of ice, mist or water thereto; Thawing or antifreeze materials for application to surfaces
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Materials Applied To Surfaces To Minimize Adherence Of Mist Or Water (AREA)
Abstract
The present invention relates to a de-icing and anti-freezing composition for freeing surfaces from snow and ice and for protecting surfaces against the formation of ice. Liquid composition of the invention comprises an aqueous solution of from about 25 to 50% w/v of an alkali metal lactate, from about 2 to 4%
v/v of an alpha-thioacid of formula R-CH(SH)-COOH wherein R denotes hydrogen atom or a lower alkyl group, from about 0.2 to 0.8% w/v of calcium chloride and from about 0.2 to 0.8% v/v of silicone-based defoamer. Preferred alkali metal lactate is sodium lactate, while preferred alpha-thioacid is thiolactic acid. For road de-icing, the composition may be used in admixture with stone aggregate having particle size of from about 0.3 to 10 mm.
v/v of an alpha-thioacid of formula R-CH(SH)-COOH wherein R denotes hydrogen atom or a lower alkyl group, from about 0.2 to 0.8% w/v of calcium chloride and from about 0.2 to 0.8% v/v of silicone-based defoamer. Preferred alkali metal lactate is sodium lactate, while preferred alpha-thioacid is thiolactic acid. For road de-icing, the composition may be used in admixture with stone aggregate having particle size of from about 0.3 to 10 mm.
Description
DE-ICING AND ANTI-FREEZING COMPOSITION
Present invention relates to a de-icing and anti-freezing composition which is non-corrosive, environmentally safe and which is readily applicable using existing snow removal vehicles.
BACKGROUND OF THE INVENTION
Common salt (sodium chloride) has been used as a road de-icer throughout the world due to its availability in virtually unlimited quantities, low cost and ease of application. In colder climates, salt may be combined or completely replaced with calcium chloride, which further lowers the freezing point of water. Adverse impact of sodium chloride on the environment - corrosion of vehicles and road structures, damage of the road surfaces and surrounding concrete and brickwork as well as the detrimental action on ground water and plants - rises the overall societal costs of its implementation.
U.S. Environmental Protection Agency, for example, has estimated that overall costs amount to 14 times the direct cost of salt, while the Ontario Ministry of Transportation deems the overall cost to be 10-20 greater. This situation has, in the past 10-15 years, motivated researchers to investigate alternative de-icing materials.
Due to the fact that common industrial salt and some other alkali metal and alkaline earth metal chlorides are considerably cheaper than almost any alternative chemical, attempts were made at retaining sodium chloride as the major component of a de-icing composition while at the same time minimizing its adverse action.
Studies were conducted on a number of anti-corrosion additives, which were aimed at either changing the pH of a de-icing composition (buffers such as phosphates, borates, etc.), enhancing its penetration properties, or retaining the salt in a slurry which would be plowed from the road surface instead of forming a solution. U.S. patents Nos. 4,668,416 and 4,824,588, for example, propose the use of lignosulfonates as penetration enhancing additives, while U.S. patent No. 5,135,674 proposes the use of hydroxyethyl cellulose as a gelling agent. While additives could be beneficial in laboratory conditions and even offer some short-period advantages in the road tests, the problem of chlorides as principal agents causing corrosion and other environmental damage remains unsolved. Therefore, the research on additives has in most instances been abandoned.
Organic materials have been subject of extensive studies, as their corrosive action is more favourable and often negligible compared to industrial salt. Of particular interest were compositions containing lower alcohols, glycols and urea. Although non-corrosive, lower alcohols are highly volatile and could be toxic. The fire danger must be taken into consideration as well.
Glycols have been extensively used as anti-freezing agents in vehicle cooling systems, but should not be released into the environment in large quantities due to extremely low biodegradability.
While being inferior to common salt below -10C, urea also poses serious environmental problems, especially after being washed into rivers and lakes - its degradation product is ammonia which is toxic to the fish even in low concentrations, while its fertiliser properties may lead to eutrophication.
Compositions comprising mixtures of alkali metal chlorides and organic materials mentioned above have also been proposed (see e.g.
U.S. patent No. 4,960,531), but they are not likely to have better environmental properties than their constituents.
Major research effort in the past few years has therefore been oriented towards developing de-icers comprising alkali metal and/or alkaline earth metal salts of carboxylic acids. Organic acids in the free acid form were discussed as well (see e.g. Canadian Patent No. 1,179,840).
Among carboxylic acid salts, calcium magnesium acetate (CMA) appears to be the most promising de-icing material. Results of extensive road tests performed in Germany, Scandinavian countries, U.S.A. and Canada have proved CMA to be an efficient alternative to 21~0649 -industrial salt. Subject of a number of patent and non-patent references, CMA was also extensively investigated and marketed as a component of a special applications de-icer by author of the present invention (Yugoslav Patent Application P-1683/89). Apart from high costs (which would probably be reduced in the case of large-scale production), CMA seems to be less efficient than salt at the temperatures below -5C.
High costs of organic chemicals have caused some researchers to investigate the possibilities of using certain waste materials as de-icers. U.S. Patent 4,430,240 proposes the use of waste polysaccharide sources (e.g. sawdust), while U.S. Patent No.
4,676,918 describes a composition containing waste concentrate of alcohol distilling industry. Canadian Patent No. 1,260,696 utilizes "black liquor", waste effluent resulting from pulping operations.
While the usage of non-toxic waste materials is environmentally sound and should be encouraged whenever possible, uniformity of composition and purity might be difficult to attain and the available amounts may not be sufficient for large-scale applications such as road de-icing.
The de-icing composition of the present invention comprises alkali metal lactates, which are cited as possible components of a complex mixture in the Canadian Patent No. 1,260,696 (referred to as "pseudolactates"). The mixture of U.S. Patent 4,430,240 contains alkaline earth metal lactates. However, the present invention features a defined mixture wherein lactates are used as a major component in admixture with specific amounts of an alpha-thioacid and calcium chloride, to provide an anti-freezing and de-icing composition with greatly enhanced properties.
OBJECTS OF THE INVENTION
The principal object of the present invention is to provide a de-icing and anti-freezing composition which is superior to the prior art compositions in respect to various disadvantages discussed above, particularly the corrosive action on metals and road surfaces as well as the environmental impact such compositions exert both directly on plants surrounding roads and other surfaces, and indirectly through sewer systems and ground water.
The further object of the present invention is to provide an environmentally safe de-icing and anti-freezing composition which can be applied at costs comparable to overall direct, societal and environmental costs of applying traditional industrial salt based de-icers.
Another object of the present invention is to provide a de-icing and anti-freezing composition which is easy to produce, store and handle and which can be applied using existing snow and ice removal systems.
Yet another object of the present invention is to provide a de-icing and anti-freezing composition which is efficient at the temperatures lower than temperatures permitting an efficient use of industrial salt and/or CMA based de-icers.
Other objects and advantages of the present invention will become apparent from the detailed description of the invention and the preferred embodiments thereof.
DETAILED DESCRIPTION OF THE INVENTION
The inventor has carried out a comprehensive study of a wide range of organic materials in order to provide municipal authorities with an efficient, non-corrosive, ecologically safe and yet economically acceptable replacement for industrial salt based de-icers. The present invention is based upon the unexpected discovery that small amounts of an alpha-thioacid of formula R-CH(SH)-COOH wherein R denotes hydrogen atom or a lower alkyl group, and calcium chloride, when mixed with alkali metal lactates, provide compositions with greatly enhanced de-icing and anti-freezing properties.
Initial studies have identified alkali metal lactates aspotential constituents of a de-icing and anti-freezing composition.
Sodium lactate is a preferred member of this group. The results 21~0649 were promising at temperatures slightly below 0C (down to approximately -5C), but performance at lower temperatures was slow and often unreliable.
After numerous trials, it was established that addition of small amounts of an alpha-thioacid significantly broadens the temperature range of application. While the exact mechanism of alpha-thioacid action was not investigated, it is believed that SH
group disruption of hydrogen bonding plays a significant part.
Calcium chloride was introduced to promote faster penetration and to improve overall performance of the composition at extremely low temperatures (below -20C). Attempts to find environmentally more appropriate replacement, which would be efficient in aqueous systems, were not sucessful. However, as the adverse environmental impact of chlorides is well known, effort was made to minimize the amount of CaCl2.
Depending upon the prices of raw materials, in might be beneficial to manufacture the composition of the present invention starting from lactic acid and corresponding alkali metal carbonate.
The process involves a simple one-step procedure which will be obvious to a person skilled in the art.
Storing and handling large amounts of aqueous/organic liquid compositions may generally give rise to two problems - excessive foaming and microbial growth in barrels, tanks and other storage vessels. The composition of the present invention is not an exception. According to the invention, the problem of foaming is solved by supplementing the liquid composition with 0.2 to 0.8% v/v of a defoamer, preferably low temperature resistant silicone-based defoamer.
Microbial growth, on the other hand, requires no particular attention - any sludge formed will be simply skimmed off the surface of the liquid.
The liquid composition of the present invention, therefore, comprises an aqueous solution of from about 25 to 50% w/v of an alkali metal lactate, from about 2 to 4% v/v of an alpha-thioacid of formula R-CH(SH)-COOH wherein R denotes hydrogen atom or a Cl3alkyl group, from about 0.2 to 0.8% w/v of calcium chloride, and from about 0.2 to 0.8% v/v of silicone-based defoamer. Preferred alkali metal lactate is sodium lactate, while preferred alpha-thioacid is thiolactic acid.
The inventor's idea was to develop a multi-purpose product which can be used both for de-icing of roads and other traffic surfaces such as airport runways, pathways, etc., and for protecting various surfaces (lower parts of cars, trucks, streetcars, as well as aircraft surfaces, open decks, etc.) against the formation of ice.
The liquid composition in its original, undiluted form, may be conveniently used as an anti-freezing agent. It could be applied to the surface to be protected in any convenient way, for example by spraying.
For de-icing purposes, the liquid composition of the present invention is sprayed onto the road surface in the amount of l liter per 10-16 m2. The benefit of using a liquid form of the composition is in the ability to achieve uniform application at high vehicle speed of up to 50 km/h.
Alternatively, the composition of the present invention may be prepared in the solid de-icer/stone aggregate form, suitable for use in the same way as known salt/stone aggregate, CMA/stone aggregate or similar mixtures. Examples of suitable stone aggregate include limestone, perlite, basalt, etc. having particle size of from about 0.3 to 10 mm, preferably from about 1 to 4 mm.
Mixing could be performed in any convenient manner, for example in a concrete mixer. According to the invention, the mixture could be supplemented with small quantities of hydrated lime and crystalline sugar in order to achieve better wetting properties and the stability of the composition.
The preferred solid composition of the present invention comprises 1 m3 of said stone aggregate in admixture with about 90 to 130 liters of above liquid composition. This quantity may be supplemented with about 1 kg of hydrated lime and about 0.5 kg of crystalline sugar.
.
The following non-limiting Examples describe some of the preferred embodiments of the present invention.
Example 1 A sample of liquid composition according to the invention is obtained by diluting 60 litres of industrial grade sodium lactate solution (60% w/v) with 40 litres of water. 3 litres of thiolactic acid are mixed with the solution.
In a separate vessel, 0.5 kg of crystalline calcium chloride (in the form of monohydrate) is dissolved in 5 litres of water and the solution obtained is mixed with the above lactate/thiolactic acid solution.
The final liquid composition is obtained by adding a 30%
solution of silicone-based defoamer (e.g. Antifoam 1430 supplied by Dow Corning) and contains, in the volume of 108.5 litres, the following:
Sodium lactate 33.18% w/v Thiolactic acid 2.76% v/v Calcium chloride 0.39% w/v Defoamer 0.16% v/v The liquid composition of this example, when sprayed in the amount of 1 litre per 10-16 m2, readily penetrates the snow and leaves the surface, after plowing, wet and free from ice. In the absence of rain it remains active for 5-10 days, while in the conditions of rain or heavy snowfall the application should be repeated each 2-4 days. When the temperatures throughout the day remain lower than -16C, composition should be sprayed in the amount of 1 litre per 6 m2 of surface.
Example 2 23.62 kg sodium carbonate monohydrate (Na2CO3 x H20) are dissolved in 36.5 litres of lactic acid (80%) and 20 litres of water, and the mixture obtained is stirred at ambient temperature overnight. The resulting solution is allowed to settle and any insoluble material is separated.
The volume is adjusted to 100 litres with water and resulting solution is treated in the same manner as in Example 1 (3 litres of thiolactic acid, 5 litres of 10% w/v CaCl2, 0.5 litres of 30%
defoamer), so as to obtain 108.5 litres of liquid composition according to the invention.
Example 3 1 m3 of crushed limestone aggregate (particle size 1-4 mm) is mixed with 108.5 litres of liquid composition of Example 1 or 2, for example in a concrete mixer. The mix is supplemented with 1 kg of hydrated lime and 0.5 kg of crystalline suggar.
The composition obtained is used as a replacement for conventional salt/abrasive mixtures and can be efficiently employed in essentially same manner and quantities to achieve improved skid resistance and disbonding of ice from the road surfaces.
While specific embodiments of the invention have been discussed in the detailled description and Examples, it should be apparent that many modifications can be made without departing from the spirit and scope of the invention. Accordingly, the invention is limited only by the scope of the claims appended hereto.
Present invention relates to a de-icing and anti-freezing composition which is non-corrosive, environmentally safe and which is readily applicable using existing snow removal vehicles.
BACKGROUND OF THE INVENTION
Common salt (sodium chloride) has been used as a road de-icer throughout the world due to its availability in virtually unlimited quantities, low cost and ease of application. In colder climates, salt may be combined or completely replaced with calcium chloride, which further lowers the freezing point of water. Adverse impact of sodium chloride on the environment - corrosion of vehicles and road structures, damage of the road surfaces and surrounding concrete and brickwork as well as the detrimental action on ground water and plants - rises the overall societal costs of its implementation.
U.S. Environmental Protection Agency, for example, has estimated that overall costs amount to 14 times the direct cost of salt, while the Ontario Ministry of Transportation deems the overall cost to be 10-20 greater. This situation has, in the past 10-15 years, motivated researchers to investigate alternative de-icing materials.
Due to the fact that common industrial salt and some other alkali metal and alkaline earth metal chlorides are considerably cheaper than almost any alternative chemical, attempts were made at retaining sodium chloride as the major component of a de-icing composition while at the same time minimizing its adverse action.
Studies were conducted on a number of anti-corrosion additives, which were aimed at either changing the pH of a de-icing composition (buffers such as phosphates, borates, etc.), enhancing its penetration properties, or retaining the salt in a slurry which would be plowed from the road surface instead of forming a solution. U.S. patents Nos. 4,668,416 and 4,824,588, for example, propose the use of lignosulfonates as penetration enhancing additives, while U.S. patent No. 5,135,674 proposes the use of hydroxyethyl cellulose as a gelling agent. While additives could be beneficial in laboratory conditions and even offer some short-period advantages in the road tests, the problem of chlorides as principal agents causing corrosion and other environmental damage remains unsolved. Therefore, the research on additives has in most instances been abandoned.
Organic materials have been subject of extensive studies, as their corrosive action is more favourable and often negligible compared to industrial salt. Of particular interest were compositions containing lower alcohols, glycols and urea. Although non-corrosive, lower alcohols are highly volatile and could be toxic. The fire danger must be taken into consideration as well.
Glycols have been extensively used as anti-freezing agents in vehicle cooling systems, but should not be released into the environment in large quantities due to extremely low biodegradability.
While being inferior to common salt below -10C, urea also poses serious environmental problems, especially after being washed into rivers and lakes - its degradation product is ammonia which is toxic to the fish even in low concentrations, while its fertiliser properties may lead to eutrophication.
Compositions comprising mixtures of alkali metal chlorides and organic materials mentioned above have also been proposed (see e.g.
U.S. patent No. 4,960,531), but they are not likely to have better environmental properties than their constituents.
Major research effort in the past few years has therefore been oriented towards developing de-icers comprising alkali metal and/or alkaline earth metal salts of carboxylic acids. Organic acids in the free acid form were discussed as well (see e.g. Canadian Patent No. 1,179,840).
Among carboxylic acid salts, calcium magnesium acetate (CMA) appears to be the most promising de-icing material. Results of extensive road tests performed in Germany, Scandinavian countries, U.S.A. and Canada have proved CMA to be an efficient alternative to 21~0649 -industrial salt. Subject of a number of patent and non-patent references, CMA was also extensively investigated and marketed as a component of a special applications de-icer by author of the present invention (Yugoslav Patent Application P-1683/89). Apart from high costs (which would probably be reduced in the case of large-scale production), CMA seems to be less efficient than salt at the temperatures below -5C.
High costs of organic chemicals have caused some researchers to investigate the possibilities of using certain waste materials as de-icers. U.S. Patent 4,430,240 proposes the use of waste polysaccharide sources (e.g. sawdust), while U.S. Patent No.
4,676,918 describes a composition containing waste concentrate of alcohol distilling industry. Canadian Patent No. 1,260,696 utilizes "black liquor", waste effluent resulting from pulping operations.
While the usage of non-toxic waste materials is environmentally sound and should be encouraged whenever possible, uniformity of composition and purity might be difficult to attain and the available amounts may not be sufficient for large-scale applications such as road de-icing.
The de-icing composition of the present invention comprises alkali metal lactates, which are cited as possible components of a complex mixture in the Canadian Patent No. 1,260,696 (referred to as "pseudolactates"). The mixture of U.S. Patent 4,430,240 contains alkaline earth metal lactates. However, the present invention features a defined mixture wherein lactates are used as a major component in admixture with specific amounts of an alpha-thioacid and calcium chloride, to provide an anti-freezing and de-icing composition with greatly enhanced properties.
OBJECTS OF THE INVENTION
The principal object of the present invention is to provide a de-icing and anti-freezing composition which is superior to the prior art compositions in respect to various disadvantages discussed above, particularly the corrosive action on metals and road surfaces as well as the environmental impact such compositions exert both directly on plants surrounding roads and other surfaces, and indirectly through sewer systems and ground water.
The further object of the present invention is to provide an environmentally safe de-icing and anti-freezing composition which can be applied at costs comparable to overall direct, societal and environmental costs of applying traditional industrial salt based de-icers.
Another object of the present invention is to provide a de-icing and anti-freezing composition which is easy to produce, store and handle and which can be applied using existing snow and ice removal systems.
Yet another object of the present invention is to provide a de-icing and anti-freezing composition which is efficient at the temperatures lower than temperatures permitting an efficient use of industrial salt and/or CMA based de-icers.
Other objects and advantages of the present invention will become apparent from the detailed description of the invention and the preferred embodiments thereof.
DETAILED DESCRIPTION OF THE INVENTION
The inventor has carried out a comprehensive study of a wide range of organic materials in order to provide municipal authorities with an efficient, non-corrosive, ecologically safe and yet economically acceptable replacement for industrial salt based de-icers. The present invention is based upon the unexpected discovery that small amounts of an alpha-thioacid of formula R-CH(SH)-COOH wherein R denotes hydrogen atom or a lower alkyl group, and calcium chloride, when mixed with alkali metal lactates, provide compositions with greatly enhanced de-icing and anti-freezing properties.
Initial studies have identified alkali metal lactates aspotential constituents of a de-icing and anti-freezing composition.
Sodium lactate is a preferred member of this group. The results 21~0649 were promising at temperatures slightly below 0C (down to approximately -5C), but performance at lower temperatures was slow and often unreliable.
After numerous trials, it was established that addition of small amounts of an alpha-thioacid significantly broadens the temperature range of application. While the exact mechanism of alpha-thioacid action was not investigated, it is believed that SH
group disruption of hydrogen bonding plays a significant part.
Calcium chloride was introduced to promote faster penetration and to improve overall performance of the composition at extremely low temperatures (below -20C). Attempts to find environmentally more appropriate replacement, which would be efficient in aqueous systems, were not sucessful. However, as the adverse environmental impact of chlorides is well known, effort was made to minimize the amount of CaCl2.
Depending upon the prices of raw materials, in might be beneficial to manufacture the composition of the present invention starting from lactic acid and corresponding alkali metal carbonate.
The process involves a simple one-step procedure which will be obvious to a person skilled in the art.
Storing and handling large amounts of aqueous/organic liquid compositions may generally give rise to two problems - excessive foaming and microbial growth in barrels, tanks and other storage vessels. The composition of the present invention is not an exception. According to the invention, the problem of foaming is solved by supplementing the liquid composition with 0.2 to 0.8% v/v of a defoamer, preferably low temperature resistant silicone-based defoamer.
Microbial growth, on the other hand, requires no particular attention - any sludge formed will be simply skimmed off the surface of the liquid.
The liquid composition of the present invention, therefore, comprises an aqueous solution of from about 25 to 50% w/v of an alkali metal lactate, from about 2 to 4% v/v of an alpha-thioacid of formula R-CH(SH)-COOH wherein R denotes hydrogen atom or a Cl3alkyl group, from about 0.2 to 0.8% w/v of calcium chloride, and from about 0.2 to 0.8% v/v of silicone-based defoamer. Preferred alkali metal lactate is sodium lactate, while preferred alpha-thioacid is thiolactic acid.
The inventor's idea was to develop a multi-purpose product which can be used both for de-icing of roads and other traffic surfaces such as airport runways, pathways, etc., and for protecting various surfaces (lower parts of cars, trucks, streetcars, as well as aircraft surfaces, open decks, etc.) against the formation of ice.
The liquid composition in its original, undiluted form, may be conveniently used as an anti-freezing agent. It could be applied to the surface to be protected in any convenient way, for example by spraying.
For de-icing purposes, the liquid composition of the present invention is sprayed onto the road surface in the amount of l liter per 10-16 m2. The benefit of using a liquid form of the composition is in the ability to achieve uniform application at high vehicle speed of up to 50 km/h.
Alternatively, the composition of the present invention may be prepared in the solid de-icer/stone aggregate form, suitable for use in the same way as known salt/stone aggregate, CMA/stone aggregate or similar mixtures. Examples of suitable stone aggregate include limestone, perlite, basalt, etc. having particle size of from about 0.3 to 10 mm, preferably from about 1 to 4 mm.
Mixing could be performed in any convenient manner, for example in a concrete mixer. According to the invention, the mixture could be supplemented with small quantities of hydrated lime and crystalline sugar in order to achieve better wetting properties and the stability of the composition.
The preferred solid composition of the present invention comprises 1 m3 of said stone aggregate in admixture with about 90 to 130 liters of above liquid composition. This quantity may be supplemented with about 1 kg of hydrated lime and about 0.5 kg of crystalline sugar.
.
The following non-limiting Examples describe some of the preferred embodiments of the present invention.
Example 1 A sample of liquid composition according to the invention is obtained by diluting 60 litres of industrial grade sodium lactate solution (60% w/v) with 40 litres of water. 3 litres of thiolactic acid are mixed with the solution.
In a separate vessel, 0.5 kg of crystalline calcium chloride (in the form of monohydrate) is dissolved in 5 litres of water and the solution obtained is mixed with the above lactate/thiolactic acid solution.
The final liquid composition is obtained by adding a 30%
solution of silicone-based defoamer (e.g. Antifoam 1430 supplied by Dow Corning) and contains, in the volume of 108.5 litres, the following:
Sodium lactate 33.18% w/v Thiolactic acid 2.76% v/v Calcium chloride 0.39% w/v Defoamer 0.16% v/v The liquid composition of this example, when sprayed in the amount of 1 litre per 10-16 m2, readily penetrates the snow and leaves the surface, after plowing, wet and free from ice. In the absence of rain it remains active for 5-10 days, while in the conditions of rain or heavy snowfall the application should be repeated each 2-4 days. When the temperatures throughout the day remain lower than -16C, composition should be sprayed in the amount of 1 litre per 6 m2 of surface.
Example 2 23.62 kg sodium carbonate monohydrate (Na2CO3 x H20) are dissolved in 36.5 litres of lactic acid (80%) and 20 litres of water, and the mixture obtained is stirred at ambient temperature overnight. The resulting solution is allowed to settle and any insoluble material is separated.
The volume is adjusted to 100 litres with water and resulting solution is treated in the same manner as in Example 1 (3 litres of thiolactic acid, 5 litres of 10% w/v CaCl2, 0.5 litres of 30%
defoamer), so as to obtain 108.5 litres of liquid composition according to the invention.
Example 3 1 m3 of crushed limestone aggregate (particle size 1-4 mm) is mixed with 108.5 litres of liquid composition of Example 1 or 2, for example in a concrete mixer. The mix is supplemented with 1 kg of hydrated lime and 0.5 kg of crystalline suggar.
The composition obtained is used as a replacement for conventional salt/abrasive mixtures and can be efficiently employed in essentially same manner and quantities to achieve improved skid resistance and disbonding of ice from the road surfaces.
While specific embodiments of the invention have been discussed in the detailled description and Examples, it should be apparent that many modifications can be made without departing from the spirit and scope of the invention. Accordingly, the invention is limited only by the scope of the claims appended hereto.
Claims (8)
1. A de-icing and anti-freezing composition for freeing surfaces from snow and ice and for protecting surfaces against the formation of ice, said composition comprising an aqueous solution of from about 25 to 50% w/v of an alkali metal lactate, from about 2 to 4%
v/v of an alpha-thioacid of formula R-CH(SH)-COOH wherein R denotes hydrogen atom or a C1-3alkyl group, and from about 0.2 to 0.8% w/v of calcium chloride.
v/v of an alpha-thioacid of formula R-CH(SH)-COOH wherein R denotes hydrogen atom or a C1-3alkyl group, and from about 0.2 to 0.8% w/v of calcium chloride.
2. A composition according to claim 1, further comprising from about 0.2 to 0.8% v/v of silicone-based defoamer.
3. A composition according to claims 1 or 2, wherein alkali metal lactate is formed in situ by reacting lactic acid or the anhydride thereof, in an aqueous solvent, with a corresponding amount of an alkali metal carbonate.
4. A composition according to claims 1 to 3, wherein the alkali metal lactate is sodium lactate.
5. A composition according to claims 1 to 4, wherein the alpha-thioacid is thiolactic acid.
6. A de-icing composition for freeing surfaces from snow and ice, said composition comprising the liquid composition according to any one of claims 1 to 5, in admixture with stone aggregate having particle size of from about 0.3 to 10 mm.
7. A composition according to claim 6, wherein 1 m3 of said stone aggregate is admixed with about 90 to 130 liters of said liquid composition.
8. A composition according to claim 6 or 7, further comprising about 1 kg of hydrated lime and about 0.5 kg of crystalline sugar to 1 m3 of said stone aggregate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002130649A CA2130649A1 (en) | 1994-08-22 | 1994-08-22 | De-icing and anti-freezing composition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002130649A CA2130649A1 (en) | 1994-08-22 | 1994-08-22 | De-icing and anti-freezing composition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2130649A1 true CA2130649A1 (en) | 1996-02-23 |
Family
ID=4154216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002130649A Abandoned CA2130649A1 (en) | 1994-08-22 | 1994-08-22 | De-icing and anti-freezing composition |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2130649A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005121271A1 (en) * | 2004-06-11 | 2005-12-22 | Trading Company S.R.L. | Antifreeze liquid composition and use thereof |
| US7314577B2 (en) | 2004-01-21 | 2008-01-01 | Cargill, Incorporated | Deicer compositions including corrosion inhibitors |
-
1994
- 1994-08-22 CA CA002130649A patent/CA2130649A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7314577B2 (en) | 2004-01-21 | 2008-01-01 | Cargill, Incorporated | Deicer compositions including corrosion inhibitors |
| WO2005121271A1 (en) * | 2004-06-11 | 2005-12-22 | Trading Company S.R.L. | Antifreeze liquid composition and use thereof |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Discontinued |