Method for production of additives enhancing water tightness of building materials

Abstract

The invention relates to an apparatus and a method for production of additives enhancing water tightness of structural and binding building materials. The method comprises the steps of: preparing a hydrophobing agent by esterifying 60-80 m % of vegetable oil by a mixture consisting of 20-40 m % ethyl alcohol and 0.1-5 m % of methyl alcohol of the whole mass of the agent, then adding 5-30 m % agent by spraying through nozzles and water to a body of burnt lime in a reactor, and prior to adding the agent and water a mixture of 2-8 m % ethyl alcohol and 0.1-1 m % of methyl alcohol of the whole mass of the body of burnt lime is added by spraying through nozzles, while the mixture is agitating mechanically till a homogeneous mixture is prepared, then adding 40-65 m % water to the mixture, and ceasing mechanical agitating after commencement of the fierce chemical reaction.

Claims

1. A method for producing additive material enhancing water tightness of structural and binding building materials comprising the steps of: preparing a hydrophobizing agent by esterification of vegetable oil such that mixing 20 to 28.9% by weight of ethanol and 0.1-5 w % methanol with 71-79.9 w % of a vegetable oil counted per total mass of the hydrophobizing agent; adding 5-30 w % of said hydrophobizing agent by spraying through jet nozzle to the quicklime, whereby the mixture is mechanically mixed until a homogeneous mixture was prepared, and then adding water 40 to 65 w % to the mixture, and breaking the mechanical mixing when a vigorous chemical reaction getting started, wherein prior to adding of said hydrophobizing agent, adding a mixture of 2-8 w % of ethanol and 0.1-1 w % of methanol, counted per mass of the quicklime, by fine spraying through jet nozzle to the quicklime, in order to decrease the value of surface tension of the burnt lime.

2. The method according to claim 1, characterized by esterifying of sunflower oil, rapeseed oil, or any mixture thereof.

3. The method according to claim 1, characterized by adding the hydrophobizing agent to the quicklime by 8 to 14 w % of the quicklime.

4. The method according to claim 1, characterized by making powdered additive material having an average particle size between 4 and 5 microns.

5. The method according to claim 1, characterized by coloring the additive material by conventional pigment.

Description

(1) The invention will be described in details by showing its preferred embodiments referring to the drawings as attached, where

(2) FIG. 1 is a perspective view of the powder mixing device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) Preparation of an additive material according to the invention is based on recognition that the burnt lime, as a conventional component of mortars in building industry the binding process of which takes place at the effect of the carbon dioxide in the air while forming CaCO.sub.3, can be mixed with an agent hydrophobic in itself by the use of a hydrophobic additive having low relative density. According to our researches the proper additives are vegetable oils such as sunflower oil, rapeseed oil, palm oil, etc.

(4) However, mixtures of vegetable oils and CaO and water form coarse dispersed systems not suitable for use in construction. Since the vegetable oils are fatty acid esters of glycerol, and the glycerol (or glycerin) is an alcohol containing three hydroxide groups, that is it is a tri-ol, in the fatty acid esters, in most cases, one fatty acid molecule blocks all three hydroxide groups of the glycerol, and properties of a glycerol ester is determined by the saturation and chain length of acids. Therefore, transformation (interesterification) of vegetable oils and fats by alcoholysis (transesterification) is a suitable means for improving the quality of flow and therefore also of dispersion properties of viscous vegetable oils and fats the of the dispersion.

(5) It has been found therefore that by means of alcoholic, preferably ethylenic and/or methylenic transesterification of said oils and then slaking the burnt lime added with transesterified oleic acids, a powdered additive material is obtained, which can be used more preferably in a wide range of constructional mortars due to its small particle size, favorable pH, highly preferred specific gravity, excellent water-repellent properties, it's very finely dispersed fraction and durable dyeability, than all known additive materials, since it does not impair their binding properties, while maintaining such favourable features like excellent water tightness and dyeability and perfectly miscible in these mortars in a homogeneous way.

(6) We have also discovered that the higher the ratio of unsaturated fatty acids in the raw material, the better the quality of resulting additive material. Especially cold-pressed vegetable oils meet this requirement.

(7) Additive material according to the present invention is produced by a hydrophobic agent consisting of transesterified vegetable oil, the composition of which (mass %, hereinafter referred to as wt %): Vegetable oil 60 to 80 wt %, Ethyl alcohol 20 to 40 wt % Methyl alcohol 0.1-5 wt %.

(8) Additive material according to the present invention can be prepared by a method according to the present invention using a powder mixing apparatus 1 consisting of a stationary drum or vessel C developed by the applicant. During the procedure CaO (quicklime) base material is charged into the drum of the powder mixing apparatus 1. Adding a mixture of 2-8 w % of ethanol and 0.1-1 w % of methanol to the quicklime, counted per mass of the quicklime, while the powder mixer apparatus 1 is in continuous operation. The alcohol mixture is supplied to the burnt lime by fine spraying. Alcohol decreases the value of surface tension of the burnt lime; the quicklime lumps disintegrate by this effect, thus contributing to increase the surface available for the reaction.

(9) Thereafter, the above-described hydrophobic agent is also introduced into the powder mixing apparatus 1 also by spraying. The amount of the hydrophobic agent is 5-30%, preferably 8-10% by weight of the amount of burnt lime base material. After the admixture is homogeneously mixed, water is added in a short time (a few seconds), which is 30 to 65 w % of the of burnt lime raw material. Based on the molar ratios for the reaction the amount of water theoretically required:
CaO+H.sub.2O.fwdarw.Ca(OH).sub.2

(10) 56 g/mol+18 g/mol.fwdarw.74 g/mol

(11) 75.6 wt % lime, and 24.4 wt % water,

(12) i.e. 32.2% of water is needed based on the mass of the burnt lime, but the lower limit of 30 wt % can be accounted for any contamination of the quicklime as well as the amount of hydrophobic agent, while a quantity of water supplied in excess can be explained by the optional need of reducing the temperature possibly affecting negatively to the structure of the powder mixing apparatus 1. The more water is added, the smaller the thermal stress applied to the powder mixing apparatus 1 would be, however, the particle size of the finished product would be higher, possibly a portion of the excess water does not vaporize, which latter increases the specific gravity of the finished product, and a subsequentand costlydrying procedure would be required. Consequently, the appropriate amount of water is 30-40 wt % of mass of the quicklime.

(13) After a violent chemical reaction started, the powder mixing apparatus 1 is stopped. Formation of hydrate of lime takes place within 2 minutes at a temperature between 100-200? C. (depending on the amount of water fed in excess and must be evaporated) and the excess water is removed as steam. When the reaction is calmed down, the powder mixing apparatus 1 is operated for a short time, and then 1 minute shutdown occurs. The finished hydrophobic additive material is discharged to a vessel. By 16-24 hours of rest, after cooling, the additive material powder can be used.

(14) Properties of the additive material made according to this invention are preferably as follow: PH 7-7.5 pH Specific gravity from 360 to 390 kg/m.sup.3 Compaction 4-5% Particle size: 4-5 microns Color: white.

(15) For making colored additive material according to the invention about 1% conventional pigment is to be admixed with the water.

(16) FIG. 1 is a perspective view of the powder mixing apparatus 1 according to the invention. Vessel C of the apparatus 1 is suspended on a foot 2 such that it is tiltable around an axis T as required by the need of feeding and discharge for example by means of a tipper motor M. A closeable feeding/dispensing opening A is formed on the vessel C, through which the materials required for achieving the process according to the invention can be delivered into the vessel C. On the bottom not shown in the FIGURE an electrically driven gear is mounted to rotate a mixing blade arranged inside the vessel C. Next to the opening A further opening G for venting steam formed by the process and an opening V for introducing water are arranged. Circumferentially on the upper part of the vessel C equally spaced nozzles F are incorporated. The mixture of ethyl alcohol and methyl alcohol as well as the hydrophobic agent can be sprayed through theses spraying nozzles F into the interior of vessel C. By the use of the apparatus 1 the sprayed in ethyl alcohol and methyl alcohol mixture as well as the hydrophobic agent are perfectly miscible with the burnt lime, in contrast to the rotary equipment conventionally used where the mixture of hydrophobic additive and the burnt lime generally adheres to the drum's wall, thereby an uneven mixing takes place, and only a portion of the materials are involved in the reactions.

Example 1

(17) 40 kg of CaO as base material is fed into the vessel C of a powder mixing apparatus 1, which is about 45 wt % of the ingredients used in the procedure. During operation of powder mixing device 1 that is by continuous mixing operation, a mixture of 2 wt % ethyl alcohol and 0.1 wt % methyl alcohol of the total mass of the quicklime fed was sprayed by nozzles F into the vessel C. Then, a hydrophobic agent is introduced into the vessel C also by fine spraying, which includes 12 wt % of the ingredients used in the process and having a composition as follows: 60 wt % sunflower oil, 39.9 wt % of ethyl alcohol, Methanol 0.1 wt %.

(18) After the admixtures have been homogeneously mixed 46 liters of water (instead of approx. 13 l) was added with stirring over a 2 to 3 sec, which includes about 52 wt % of the entire content of the vessel C (that is in a large stoichiometric excess). After the chemical reaction was started, the apparatus 1 is stopped. The forming reaction of hydrated lime took place at 100? C. about within 2 minutes, a portion of the excess water vented in the form of steam. After the reaction calmed down a short stirring for 1 minute and a stop occurred. Then the vessel C is tilted around the axis T, the apparatus 1 was operated again and the finished hydrophobic additive material emptied into a storage tank. Following a 24-hour rest and after cooling the additive material showed the following properties: pH 9 A specific gravity: 430 kg/m3 7% compaction Particle size: 7 microns Color: yellowish white.

Example 2

(19) 40 kg of CaO as base material is fed into the vessel C of a powder mixing apparatus 1, which is about 45 wt % of the ingredients used in the procedure. During operation of powder mixing device 1 that is by continuous mixing operation, a mixture of 3 wt % ethyl alcohol and 0.2 wt % methyl alcohol of the total mass of the quicklime fed was sprayed by nozzles F into the vessel C. Then, a hydrophobic agent is introduced into the vessel C also by fine spraying, which includes 8 wt % of the ingredients used in the process and having a composition as follows: 60 wt % sunflower oil, 38 wt % of ethyl alcohol, methanol 2 wt %.

(20) After the admixtures have been homogeneously mixed 12 liters of water was added with stirring over a 2 to 3 sec, which includes about 26 wt % of the entire content of the vessel C (that is fewer than stoichiometric ratio). After the fierce chemical reaction was started, the apparatus 1 is stopped. The forming reaction of hydrated lime took place at 190? C. about within 1 minutes, a small portion of the water vented in the form of steam. After the reaction calmed down a short stirring for 1 minute and a stop occurred. Then the vessel C is tilted around the axis T, the apparatus 1 was operated again and the finished hydrophobic additive material emptied into a storage tank. Following a 24-hour rest and after cooling the additive material showed the following properties: pH 8 A specific gravity: 440 kg/m3 8% compaction Particle size: 5 microns Color: white.

Example 3

(21) 40 kg of CaO as base material is fed into the vessel C of a powder mixing apparatus 1, which is about 45 wt % of the ingredients used in the procedure. During operation of powder mixing device 1 that is by continuous mixing operation, a mixture of 4 wt % ethyl alcohol and 0.3 wt % methyl alcohol of the total mass of the quicklime fed was sprayed by nozzles F into the vessel C. Then, a hydrophobic agent is introduced into the vessel C also by fine spraying, which includes 6 wt % of the ingredients used in the process and having a composition as follows: 60 wt % sunflower oil, 38 wt % of ethyl alcohol, methanol 2 wt %.

(22) After the admixtures have been homogeneously mixed 25 liters of water was added with stirring over a 2 to 3 sec, which includes about 35 wt % of the entire content of the vessel C (that is in more than stoichiometric). After the chemical reaction was started, the apparatus 1 is stopped. The forming reaction of hydrated lime took place at 150? C. about within 1 minutes, excess water vented in the form of steam. After the reaction calmed down a short stirring for 1 minute and a stop occurred. Then the vessel C is tilted around the axis T, the apparatus 1 was operated again and the finished hydrophobic additive material emptied into a storage tank. Following a 24-hour rest and after cooling the additive material showed the following properties: pH 7 A specific gravity: 390 kg/m3 7? A) compaction Particle size: 5 microns Color: white.

Example 4

(23) 40 kg of CaO as base material is fed into the vessel C of a powder mixing apparatus 1, which is about 45 wt % of the ingredients used in the procedure. During operation of powder mixing device 1 that is by continuous mixing operation, a mixture of 5 wt % ethyl alcohol and 0.5 wt % methyl alcohol of the total mass of the quicklime fed was sprayed by nozzles F into the vessel C. Then, a hydrophobic agent is introduced into the vessel C also by fine spraying, which includes 4 wt % of the ingredients used in the process and having a composition as follows: 57 wt % sunflower oil, 40 wt % of ethyl alcohol, methanol 3 wt %.

(24) After the admixtures have been homogeneously mixed 25 liters of water was added with stirring over a 2 to 3 sec, which includes about 35 wt % of the entire content of the vessel C (that is more than stoichiometric). After the chemical reaction was started, the apparatus 1 is stopped. The forming reaction of hydrated lime took place at 140? C. about within 1 minutes; excess water vented in the form of steam. After the reaction calmed down a short stirring for 1 minute and a stop occurred. Then the vessel C is tilted around the axis T, the apparatus 1 was operated again and the finished hydrophobic additive material emptied into a storage tank. Following a 24-hour rest and after cooling the additive material showed the following properties: pH 7 A specific gravity: 360 kg/m3 4% compaction Particle size: 4 microns Color: snow-white.

Example 5

(25) 40 kg of CaO as base material is fed into the vessel C of a powder mixing apparatus 1, which is about 45 wt % of the ingredients used in the procedure. During operation of powder mixing device 1 that is by continuous mixing operation, a mixture of 6 wt % ethyl alcohol and 0.6 wt % methyl alcohol of the total mass of the quicklime fed was sprayed by nozzles F into the vessel C. Then, a hydrophobic agent is introduced into the vessel C also by fine spraying, which includes 6 wt % of the ingredients used in the process and having a composition as follows: 57 wt % sunflower oil, 38 wt % of ethyl alcohol, methanol 5 wt %.

(26) After the admixtures have been homogeneously mixed 25 liters of water was added with stirring over a 2 to 3 sec, which includes about 35 wt % of the entire content of the vessel C (that is more than stoichiometric). After the chemical reaction was started, the apparatus 1 is stopped. The forming reaction of hydrated lime took place at 140? C. about within 1 minutes, a portion of the excess water vented in the form of steam. After the reaction calmed down a short stirring for 1 minute and a stop occurred. Then the vessel C is tilted around the axis T, the apparatus 1 was operated again and the finished hydrophobic additive material emptied into a storage tank. Following a 24-hour rest and after cooling the additive material showed the following properties: pH 7.5 A specific gravity: 480 kg/m3 5% compaction Particle size: 4 microns Color: white.

Example 6

(27) 40 kg of CaO as base material is fed into the vessel C of a powder mixing apparatus 1, which is about 45 wt % of the ingredients used in the procedure. During operation of powder mixing device 1 that is by continuous mixing operation, a mixture of 7 wt % ethyl alcohol and 0.7 wt % methyl alcohol of the total mass of the quicklime fed was sprayed by nozzles F into the vessel C. Then, a hydrophobic agent is introduced into the vessel C also by fine spraying, which includes 5 wt % of the ingredients used in the process and having a composition as follows: 57 wt % cold pressed sunflower oil, 40 wt % of ethyl alcohol, methanol 3 wt %.

(28) After the admixtures have been homogeneously mixed 25 liters of water was added with stirring over a 2 to 3 sec, which includes about 35 wt % of the entire content of the vessel C (that is more than stoichiometric). After the chemical reaction was started, the apparatus 1 is stopped. The forming reaction of hydrated lime took place at 140? C. about within 1 minutes; excess water vented in the form of steam. After the reaction calmed down a short stirring for 1 minute and a stop occurred. Then the vessel C is tilted around the axis T, the apparatus 1 was operated again and the finished hydrophobic additive material emptied into a storage tank. Following a 24-hour rest and after cooling the additive material showed the following properties: pH 7.5 A specific gravity: 490 kg/m3 5% compaction Particle size: 5 microns Color: snow-white.

Example 7

(29) 40 kg of CaO as base material is fed into the vessel C of a powder mixing apparatus 1, which is about 45 wt % of the ingredients used in the procedure. During operation of powder mixing device 1 that is by continuous mixing operation, a mixture of 8 wt % ethyl alcohol and 1 wt % methyl alcohol of the total mass of the quicklime fed was sprayed by nozzles F into the vessel C. Then, a hydrophobic agent is introduced into the vessel C also by fine spraying, which includes 5 wt % of the ingredients used in the process and having a composition as follows: 50 wt % cold pressed rape-seed oil, 47 wt % of ethyl alcohol, methanol 3 wt %.

(30) After the admixtures have been homogeneously mixed 25 liters of water was added with stirring over a 2 to 3 sec, which includes about 35 wt % of the entire content of the vessel C (that is more than stoichiometric). After the chemical reaction was started, the apparatus 1 is stopped. The forming reaction of hydrated lime took place at 140? C. about within 1 minutes, a portion of the excess water vented in the form of steam. After the reaction calmed down a short stirring for 1 minute and a stop occurred. Then the vessel C is tilted around the axis T, the apparatus 1 was operated again and the finished hydrophobic additive material emptied into a storage tank. Following a 24-hour rest and after cooling the additive material showed the following properties: pH 7.5 A specific gravity: 490 kg/m3 5% compaction Particle size: 5 microns Color: white.

(31) By using additive materials prepared according to the Examples 1-7 concrete specimens were made and tested according to the standard EN 12390-8: 2001 on 5 bar pressure for 72 hours. Specimens were also prepared by adding tile adhesive and wall plaster as well.

(32) Water penetration depth (watertight) of the concrete specimens treated with additive material according to Examples 2-7 met the requirements of HV3 (H) rating based on the standard, while a specimen treated by materials according to Example 1 has reached the rating HV-2 (H) as well. Cement-based wall-plasters and tile adhesives (colored or uncolored) treated by additive materials according to Examples 2-7 complete water tightness and excellent vapor diffusion effect and color retention were observed, particularly by additives made according to the Example 4.

(33) We have also found that any mixture of sunflower oil and rapeseed oil can equally be used for producing additive materials according to the invention.

(34) The additives according to the invention were tested in connection with adsorption of oil derivatives as well. Compared to adsorbents of the prior art we have found a specifically greater amount of oil adsorbed, particularly when using sunflower oil. Due to enormous specific surface of the additive resulting from its particle size of 4-5 microns, its extinguishing effect is remarkable, and doe to its low specific gravity it can preferably be used in dry-powder extinguishers, too.

(35) The main advantage of the powdered additive material of the present invention to be used in construction and structural binders, such as adhesives, mortars, wall plaster materials and cements is that enhances water tightness of structural and binding building materials compared to the additives of the prior art by excluding the moisture from the structure rather than binding it, as well as cheap to produce, has a low specific weight, and its use is harmless both to the environment and the user. Moreover, the additives of the present invention are chemically stable, and can be durably colored in itself. The additive material according to the invention can be produced simply and cheaply by the method and apparatus according to the invention, without a need of subsequent drying and pulverizing.