HK1181006B - Materials for producing transparent heat protection elements and light protection elements produced using such materials, and method for the production thereof - Google Patents
Materials for producing transparent heat protection elements and light protection elements produced using such materials, and method for the production thereof Download PDFInfo
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Description
The invention relates to silicate-based materials for the manufacture of light-transmitting thermal insulators with at least two carrier elements and a protective layer between the carrier elements and a method for the manufacture of thermal insulators incorporating such a protective layer.
The above-mentioned thermal insulation elements are known in various forms and are used as building elements, among others. The most commonly used as supporting elements are glass panes, but other light-transmitting materials such as plastics are also used. Particularly high requirements for thermal insulation are placed on components which are used in the form of glazing for facades and as boundaries of interior spaces such as partitions and doors, or on board and offshore.
In the manufacture of thermal insulating composite glass, either a thin layer of alkaline silicate is applied to one side of a glass plate in liquid form and then dried by removing the excess water, for example by thermal action, or an alkaline silicate is cured with an acidic component, e.g. silica (EP 0 620 781).
WO 2007/060203 describes two processes for the production of thermal insulation elements with a low water content in the protective layer: one process involves partial drying of an aqueous solution or a salt containing an alkalilicate, and the other process involves the hardening of such a solution or a salt by the addition of colloidal silicon dioxide.
The curing of SiO2 pyrogen stabilised with a polyol by algae, e.g. KOH, is also known (see DE 197 20 269).
The pre-treatment of the glass pane with a primer which promotes the detachment of the fireproof glass pane from the protective layer and thus prevents the protective layer from breaking off, leading to better performance in the fire test, is also known.
US 5.508.321 describes a silicone rubber that forms a foam layer and includes expandable foaming material, polyorganosiloxane, hydrated alkali metal silicate and silicone-based elastomeric binder.
DE 10 2004 031 785 and WO 2006/002773 respectively describe dispersions containing SiO2, in particular pyrogenic SiO2, and their manufacture.
US 3.655.578 describes stabilized silica salt with a surface area of 500-1500 m2/g. Stabilization is performed by a stabilizer system consisting of a base and a non-aromatic organic compound consisting of hydrogen, carbon and oxygen, having at least 2 OH or ether groups and good water solubility.
WO 2008/090333 was published after the priority date of the present invention and describes a flame retardant coating containing aluminosilicate which is cured by drying and contains a highly boiling organic compound, e.g. a silicone oil, to prevent a powdery state after drying. WO 2008/091129 is also a post-priority date document which describes a flame retardant coating of foamed resins, such as polystyrene, based on alkalilicate and in the alkaline range soluble SiO2 powder This basic component may contain sugar or modified starch and/or silicone oil and/or organos and/or boric acid or boric acid.
US 4.162.169 describes inorganic binders obtained by mixing alkalilicate with SiO2 hydrogel and a silicone oil and US 5.137.573 reveals a coating mass comprising colloidal silicon dioxide, an organohydroxylane and a solvent containing ethylene glycol monobutylether.EP 1 561 728 describes hydrophobic precipitating sulphuric acids and their production.
Although the known light-transmitting thermal insulation elements already meet high requirements in terms of heat and fire protection, they are still unsatisfactory in terms of processing and/or production costs and/or fire performance and other thermal insulation materials have no or no light-transmittance or transparency.
The purpose of the invention is therefore to create a light-permeable thermal insulation, which has a protective layer with high resistance to aging, which can be produced in a preferred embodiment by casting and without drying, and which has good intrinsic strength and optimized adhesion to the adjacent supporting elements.
Both the casting and drying and the casting and subsequent hardening conditions require that the starting mass for the protective layer must be fluid and, in the case of hardening, also fit for ingestion in cavities, have a sufficient potting time and, after coating or filling, still harden rapidly to a protective layer with good fire protection properties.
The present invention overcame a prejudice that, due to the other (particle) properties, such as higher OH group densities in the sol and/or on the surface and less homogeneous particle sizes of the primary particles, precipitating sulphuric acid and/or silica salt could not be used for OH curing, but this assumption has now been shown to be incorrect.
As mentioned above, the use of precipitating sulphuric acid instead of pyrogenic SiO2 had been considered impossible before this invention due to the different material properties. Surprisingly, it has now been shown that the other material properties, in particular the increased proportion of Si-OH groups on the surface of the particles and the possibly more heterogeneous particle size distribution, do not have an adverse effect on the finished protective layer.
The advantage of using precipitated sulphuric acid is, among other things, the significantly lower price, but the production of a homogeneous dispersion has presented problems.
Only after several attempts to produce a stable dispersion in which the SiO2 particles are present in a stable state by polyol and KOH was an addition process found which yields suitable dispersions.
An amorphous precipitating sulphuric acid suitable for the production of a fire-retardant layer has a SiO2 content of at least 98.5% by weight, preferably at least 98.8% by weight, and in particular at least 99.1% by weight, and a BET surface area of about 20 to about 100 m2/g. For dispersions with SiO2 content of about 35 to about 42% by weight, a BET of 80 to 100 m2/g may be used, for higher concentrated dispersions a BET of 20 to 80 m2/g. The mean primary size is usually 10 to 70 nm, in particular 20 to 40 nm, with larger mean primary size sizes being used, provided that the pressure is not increased rapidly after all the particles within the dispersion are within the range of the maximum pressure distribution (O2).
The starting material for the protective layer may be a de-foaming agent, an inner primer and, where appropriate, an additive such as ammonia, which improves the appearance and/or the viscosity of the dispersion or the curing of the protective layer and/or prolongs its potting time. The de-foaming agent causes the degassing of the protective layers to occur more rapidly during manufacture and after pouring on a glass pane or filling the space between two glass panes and/or causes the bubbles to be so small that they disappear during the drying or scrubbing process, i.e. no longer visible. A primer reduces the current protection layer on the glass pane to such an extent that it avoids a large fire when the glass pane is replaced by a fireproof glass pane, thus avoiding a large loss of protection from the fire.
The use of an internal primer makes it possible to avoid the need for the glass panes to be treated with a primer.
Surprisingly, it has now been found that certain silicon-containing compounds in protective coating compounds act as defoamers and primers without adversely affecting the final properties of the protective coating.
In particular, such compounds are polymonoalkylsiloxane or polydialkylsiloxane with short alkyl groups, e.g. linear or branched C1 to C4 alkyl groups, with 5 to 350 monomer units, preferably 15 to 350 monomer units, in particular 90 to 350 units, whereby in the case of linear siloxanes the polymer chain may be substituted at one or both ends (in the α and/or ω positions) with alkyl groups, in particular methyl groups, or where appropriate with other organic residues. A particularly preferred primer is polydimethylsiloxane (also known as Poly[oxydimethylsiloxane] GmbH or α-Trimethylsiloxane) or polydimethylsiloxane (also known as polydimethylsiloxane) with a molecular weight of 0.00 to 0.00 g/cm3 (MW) at one or both ends (in the α and/or ω positions) and a specific weight of 0.00 to 0.00 to 0.00 g/cm3, e.g. in the USA, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Germany, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy, Italy
The present invention includes the ammonium salts of polysiloxane, together with free ammonia, as appropriate.
The defoaming effect of such compounds is known, e.g. from medicine, but their applicability as defoamers in compositions suitable for the manufacture of protective coatings, let alone their simultaneous effect as an internal primer, is not known.
It is assumed, without the applicant being bound by any theory, that the effect as an internal primer is at least partly due to the known affinity of glass surfaces to siloxanes, so that the siloxanes are concentrated on the glass surface as a result of diffusion and, as a result of the siloxan groups, reduce the concentration of the surface groups responsible for the adhesion of the protective layer and, respectively, promote displacement in the event of fire. In addition, the foaming properties in the area near the protective layer promote the escape of gas (e.g. the evaporation effect of water formed in the glass due to heat) so that this buildup occurs between the glass curve and the protective layer and further promotes displacement.
Protective layer compositions to which a defoamer and/or primer can be added as described above are SiO2 dispersions of claim 1 which can be solidified with KOH.
The hardened protective coatings also have improved fire performance compared to analogue protective coatings without siloxane.
The preferred protective coatings have a molar ratio of silicon dioxide to alkali metal oxide greater than 4:1 in the tempered state. This ratio may be used to characterize a polysilicate or a mixture of polysilicates with nanoscale silicon dioxide particles, i.e. invisible to the eye, contained in them. The water content of such solidified coatings is preferably in the range of 35% to 60% by weight, the silicon dioxide content in the range of 30 to 55% by weight and the content of alkali metal oxide (M2O) selected from the group consisting of sodium oxide, potassium oxide, Lumo oxides and mixtures of these is not more than 16% by weight.
The stabilization of pyrogenic or precipitated silica and/or silica salt is carried out by polyoles such as ethylene glycol, propylene glycol and glycerol.
Such stabilised silica acids can be solidified by addition of lye, e.g. NaOH, KOH, etc., with KOH being preferred to NaOH.
The siloxane can be added to either the silicate or silicon dioxide component or the hardening component, the potassium eye. The hardening component is defined as compounds or compounds which, after addition, cause the layer to solidify. Since it is advantageous to degase them when using SiO2 particle dispersions, siloxane is preferably added to the SiO2 dispersion. Similarly, but at least for the time being, it would not be preferable to add siloxane during the mixing of the dispersion with the hardening component.
The amount of siloxane added is approximately 0.1 to 10% by weight for transparent glass, in particular 0.5-3% by weight, preferably 0.5 to 2.5% by weight depending on the mass of the hardened layer.
A suitable SiO2 dispersion for solidification by addition of lye consists of:
35-52% by weight of SiO230-50% by weight of water0.5-0.7% by weight of KOH0-13 by weight of alkyl siloxane0-6 by weight of ammonia (32% aqueous solution) Remaining glycerol and/or ethylene glycol, e.g. 47.0-48.5% by weight of SiO233.8-30.9% by weight of water0.6 ± 0.1% by weight of KOH0-10 by weight of alkyl siloxane0-2.5 by weight of ammonia solution (32% by weight in water) Rest glycerol and/or ethylene glycol containing at least 5% by weight of glycerol and/or ethylene glycol.
Currently preferred dispersions include:
47.0% by weight of SiO232.8% by weight of water0.6% by weight of KOH0.5-3% by weight of alkyl siloxan, especially polydimethyl siloxan,0-0.5% by weight of ammonia (32% aqueous solution) Remaining glycerin and/or ethylene glycol or 48.2% by weight of SiO230.9% by weight of water0.5% by weight of KOH0.5-3% by weight of alkyl siloxan, especially polydimethyl siloxan,0-0.5% by weight of ammonia (32% aqueous solution) Remaining glycerin and/or ethylene glycol.
The polyol, especially glycerol and ethylene glycol, and KOH are used to stabilize the SiO2 particles in the dispersion and to lower the freezing point.
Due to its stabilizing function, the polyol should be present in amounts of at least 5% by weight, preferably at least 8% by weight, and preferably at levels of 10 to 20% by weight.
A SiO2 content of 45 to 50% by weight has proved advantageous, since at such a level a sufficient amount of KOH can be added as a solution and still highly concentrated protective layers are available.
Ammonia may be added to the protective layer in absolute amounts (i.e. calculated as 100% NH3) of approximately 0,1 to a maximum of 2% by weight, preferably a maximum of 0,8 to 0,9% by weight of dispersion and/or hardener, partially or fully bound to the polysiloxane, if appropriate, to improve, for example, the properties.
In the SiO2 dispersion, amounts up to about 6% w/w aqueous ammonia solution (32% w/w), in particular up to about 2.5% w/w aqueous ammonia solution (32% w/w), and minimum amounts of 0.1% w/w, preferably 0.5% w/w aqueous ammonia solution (32% w/w), have been shown to be appropriate.
A differentiated time and temperature profile is well suited for the production of the dispersion, comprising:
(i) presentation of water, at least part of the KOH and at least part of the polyolsii) continuous addition of SiO2.
Since the dispersion rapidly loses its processing capability during dispersion at temperatures above 40°C, cooling to < 40°C is recommended.
The following means and procedure have been found to be well suited for the large-scale production of a dispersion according to the invention:
1) Double-walled vacuum-tight stirring container with a cooling coating and stirrer, e.g. a slow-spinning anchor stirrer with a 2 to 10 kW stirring motor, adjustable to speeds of 1 to 85 rpm.2) Coating cooling, e.g. cooling unit.3) Coating heating, e.g. hot water or steam generator.4) Vacuum pump, in particular, capable of generating a vacuum up to about 100 mbar, preferably < 100 mbar, in particular ≤ 70 mbar. e.g. water ring pump, oil slide pump or vacuum venturi pump.5) For the injection unit, in particular inline homogeniser with a powder intake for a nanotube or nanotube, with a liquid flow, vacuum supply and RSETA®.
In case an inline homogeniser is used, an additional nanosphere mill may be inserted into the dispersion circuit.
For a 200 1 volume stirring tank, a 50 1 volume double coat and a heating or cooling flow rate of 40 1/min are suitable.
Heat the container to approximately 40°C and mix the contents, for example at 50 U/min for approximately 10 minutes, then pump the liquid phase into the circulation by stirring it through a dispersing device, in particular an inline homogeniser or, where appropriate, a nanobubble. The dispersing device is preferably designed so that the addition of SiO2 is continuous through this dispersing device, in particular by continuously drawing pulse into the liquid stream through a side channel and continuously doubling the pulse with the dispersing device (the final dispersant is then pumped into the circulation device after the dispersing device has been selected or the homogeniser is placed in the dispersing device)The temperature of the reactor is maintained at approximately 40 °C during the final spraying by cooling, until the current intake is constant, usually at about 35 A. The temperature is increased by the energy input, and the dispersion is then stirred under vacuum, for example for 2 to 4 hours at 40 °C at 5 U/min, depending on the concentration of the dispersion. The reactor is then cooled down to 20 °C and the pH is adjusted to about 10,5 - 10,9 with KOH if necessary. The dispersion can be filled, preferably by subtraction by a 100 μm bag filter, especially in plastic-bound IBC-bound bags.
Degassing the dispersion is not absolutely necessary, but it optimizes the quality of the dispersion for storage and further processing.
A dispersion with reduced viscosity is obtained when the glycerin is added in two portions, one before the introduction of SiO2 and one after dispersion. It also follows that the amount of glycerin in the dispersion can be varied in certain areas without compromising the manufacturability. For example, the amount of polyol can be reduced in favour of siloxane, with a minimum amount of polyol of 5% by weight, preferably 8% by weight, and in particular 10 to 20% by weight if a dispersion of SiO2 particles is used.
A further or additional way of reducing viscosity and, where appropriate, increasing the potting time is the addition of ammonia and/or silica.
A dispersion with optimized particle sizes can be obtained by using, for example, a nanosphere mill within the dispersion cycle, either in the SiO2 mixing range or in the mixing range switched on and/or off.
Pre-processing preferably involves storing a suitable dispersion for up to 14 days at 20 to 25°C. This storage results in better-defined materials. What exactly happens during storage is not clear. Without a theory, homogenization of the SiO2 particles could occur, according to which dispersions usually grow larger particles at the expense of smaller particles, but probably a reduction in active radicals and a shift in the ratio of siloxan to silanol groups.
Such dispersion can be cured by adding KOH, for example at 70-80°C for 8-10 hours.
The manufacture of the protective layer dispersion and curing can be carried out with the following parameters:
The test chemical is used to determine the concentration of the test substance in the test medium.
The test chemical is a mixture of the following:
The dispersion is introduced into the reactor and the stirrer is switched on, for example at about 50 R/min. The potassium eye is added under stirring, creating a highly viscous, creamy mass. During stirring, a temperature rise occurs, preferably to 45-60°C, especially to about 55°C. If the heat of mixing is not sufficient, it can be actively heated. When the maximum temperature is reached (usually about 45 to 60°C after about 15 min; if the exothermia of the mixing process is not sufficient, it can be heated), this temperature is maintained for 15-45 min until the viscosity decreases, usually to about 50 m. Then it is cooled to 40 - 45 °C.
The reaction is then closed tightly and a vacuum is applied, preferably a vacuum of < 100 mbar, in particular about 50 to 90 mbar absolute, the temperature is kept at boiling temperature, in the upper vacuum range of about 42 to 45 °C, so that the mixture boils and air bubbles are forcefully pushed to the surface and explode. The viscosity increases to about 150 to 250 mPa. During degassing, the stirring speed is reduced, usually to about 5 rpm. The boiling temperature is kept under vacuum for a sufficiently long period of time, usually 15 to 45 min, so that the reactor boils and the material contained in the air is expelled as a gas blown out.The reaction is then cooled to 20-25 °C with cooling water as quickly as possible to avoid unnecessary shortening of the processing time. The rapid cooling allows for a processing time of about 3 hours (at 55°C about 2 to 2.5 hours) and preferably for about 1 hour to 1.5 hours under stirring at 20-25 °C at 5 U/min to ensure no bubbles. The stirrer and vacuum pump are then switched off, after which the reactor can be vented, emptied and preferably cleaned immediately.
This layer dispersion produced, after curing, clear, bubble-free protective layers with excellent fire performance.
An analogous solution of silica may be used, which may need to be concentrated by water removal depending on the initial concentration.
A suitable manufacturing process based on silica includes the following steps:
If a higher concentration of SiO2 is desired, the mixture may be stirred to about 45-60 °C, e.g. 45-50 °C, vacuum (preferably about 50-90 mbar) and the desired amount of water removed from the mixture by boiling under vacuum. The mixture containing the silica is then added and the resulting mixture stirred while it reacts to a highly viscous cream. The reaction raises the temperature to about 45-50 °C.The viscosity drops to about 20 - 50 mPa after about 15 - 30 min. After about 15 - 45 min, the reaction flask is cooled to about 40 - 45 °C (appropriate stirring rate about 10 U/min), the reaction flask is vacuum sealed and a vacuum of < 100 mbar is applied. For a vacuum of about 50 - 90 mbar, a temperature of 40 - 45 °C is suitable to ensure that the reactor contents boil.The vacuum is maintained at 20-25°C for approximately 60 min to ensure bubble-free flow. The viscosity rises again, usually to about 50-100 mPa. At the end of the reaction, the agitator and vacuum pump are switched off and the reaction flask is vented.
The initial viscosity of 50-100 mPa increases slowly over time, so the potting time is limited to about 6 h.
The use of a siloxane with a defoaming effect (reducing surface tension) and a primer effect, which also does not affect the optical properties, together with ammonia, where appropriate, can increase the workability and quality of the protective layer, whether it is made from a dispersion or from a pebble salt.
The above-described dispersions and brine can also be used in combination. Depending on the solid content in the brine and the particle size of the brine, the properties of the protective layer can be controlled. For example, pure silica brine (e.g. 50m2/g, 50% SiO2 content) has a deep viscosity, which is very good for processing, it gives a good processing time (pot time) but too little fire resistance time.
For example, the potting time can vary widely depending on the ratio of silica dispersion to silica salt. For a composition of precipitation silica dispersion as described above and alkaline stabilized silica salt (50 m2/g, 50% by weight SiO2 content), a prolongation of the potting time with increasing silica content was found (see Table 1).
Other Tabelle 1
| Dispersion aus Fällungskieselsäure [%] | Topfzeit bei 55°C [Std.] | |
| 0 | 100 | >6 |
| 25 | 75 | 5-6 |
| 50 | 50 | 5 |
| 75 | 25 | 4 |
| 100 | 0 | 2-2.5 |
A mixture of precipitated sulphuric acid dispersion and silica salt has the further advantage of being degassed more quickly and/or in a smaller vacuum than a pure precipitated sulphuric acid dispersion. In particular, degassing of the dispersion before mixing with the potassium eye can also be avoided. The degassing behaviour is further enhanced by the addition of the defroster of the invention, in particular PDMS.
The properties of a silica salt, such as its solidification by gel formation, are highly dependent on the particle size, so silica with a large surface area is more rapidly gelidified by electrolyte addition than silica with a smaller surface area.
In order to obtain the desired processing and finishing properties, it may therefore be advantageous to use mixtures of pebbles with different surfaces, in particular stability greens, as pebbles with larger surfaces are less concentrated than those with smaller surfaces.
Commercially available silica salts, such as Levasil by Fa. H. C. Starck in Leverkusen, Germany, are acid or alkaline stabilised to achieve the desired stability and are more or less highly concentrated, depending on the particle size. In particular, the application concerns alkaline stabilised silica salts, in particular those stabilised with KOH and/or ammonia where appropriate. Since highly concentrated dispersions or salts are essential for the purposes of the present invention, the commercial salts must be concentrated in most cases. This can be done, as described above, for example by adding polyols such as glycerin and ethyl chloride to further stabilise the solvent, which is concentrated and evaporated by water and concentrated on the solvent.
A dispersion from a SiO2 particle, e.g. precipitating sulphuric acid, containing dispersion and silica, can be produced by mixing the two dispersions at temperatures below 60 °C and at high shear and stirring rates, e.g. in a dispersion device.
The method for producing a light-transmitting thermal insulation using a dispersion and/or a sol, as described above, is characterised by the dispersion or sol being dispersed and solidified with a solution of potassium hydroxide. The solidification is preferably done without draining water. In this case, the dispersion is introduced into a mould cavity after dispersing with a potassium eye and then cured to a solid protective layer, preferably at elevated temperature, while maintaining the water content. The ratio of silicon dioxide to alkali metal oxides in the protective layer is preferably greater than 4:1.
The method of the invention thus makes it possible to directly produce connecting elements consisting of several supporting elements, e.g. glass panes, placed at a distance from each other. In particular, to achieve higher thermal resistance values, heat-protecting elements can be directly formed, in which the heat-protecting element consists of several protective layers placed between two supporting elements and the supporting elements and the protective layers form a connecting element. In this case, two supporting elements are connected at a distance from each other so that a desired intermediate space is defined. This separation can be achieved, for example, by means of a butyl and silicone mesh, a polysulphite, a polymer or a hot-hardened rubber, whereby a suitable distance is measured between the protective element and the required protective layer.
Preferably, the protective layer mass is degassed before processing, ensuring that no gas is present in the hardened protective layer that could interfere with the optical quality of the thermal insulation according to the invention.
To increase the quality of the protective layer, a siloxane is added to either the silicon dioxide or silicate composition and/or to the hardener before the protective layer mass is mixed, which can avoid pre-treating the carrier elements with a primer. However, for the purpose of this invention, it is appropriate to use an external primer in addition to the use of an internal primer or instead of an internal primer (e.g. if the defoamer does not develop or poorly develops an internal primer effect or if no primer is added at all). Such an (external) primary layer is referred to as an auxiliary layer for the purpose of the present invention.
The carrier elements for the light-transmitting thermal insulation of the invention are not only glass elements, especially glass plates, but also other materials with the desired optical properties, provided that they meet the technical and physical requirements, for example, for heat resistance. The resistance of the thermal insulation is in any case improved by a high water content and the siloxane.
The hardened protective layers are of high optical quality and permeability and have good ageing resistance and fire protection properties.
The following examples illustrate the present invention.
Effect of glycerin addition on the viscosity of a dispersion
The composition:
48.2% by weight of SiO219.6% by weight of Glycerin31.6% by weight of Water0.6% by weight of KOH
Manufacture Approach 1 (approximately 20 litres):1 Prepare municipal water and glycerine2 Stir potassium foam3 Stir SiO2 (falling sulphuric acid)4 Homogenise with Turrax 3 min (IKA 10'000UPM)5 Fill over 5 μm filter bag6 Draw standard samples
The manufacturer shall provide the following information:
Temperature during mixing and dispersion: 25°C.Dispersion time, in the circulation system: 60 min.Time between dispersion and degassing: 5 min.Coat temperature during degassing: 40°C.
Duration of degassing: 20 min.Pressure during degassing: 50 mbarCooling after degassing to: 10°C Filtering by the smallest filter possible
The manufacturer shall provide the following information:
1 Municipal water and glycerin quantity I2 Add potassium ions3 Add SiO2 (falling sulphuric acid) 4 Add glycerin quantity II5 Homogenise with Turrax 3 min (IKA 10'000UPM) 6 Fill with 5 μm filter bag7 Draw standard samples
| Stadtwasser | 9.60 | 33.07 | 9.60 | 32.99 | 33.07 | |
| Glycerin | Menge I | 5.63 | 19.39 | 2.20 | 19.52 | 19.41 |
| Menge II | --- | 3.48 | ||||
| Kalilauge | 0.30 | 1.03 | 0.30 | 1.03 | 0.99 | |
| 13.50 | 46.50 | 13.52 | 46.46 | 46.53 | ||
| Glührückstand [Gew.-%] | 45.5 | 45.3 | 48.3 | |||
| pH-Wert (Original) | 10.6 | 10.6 | 10.8 | |||
| Viskosität (Brookfield), 20°C [mPas] | 205 | 140 | 233 | |||
| Dichte (20°C) [g/ml] | 1.4203 | 1.4195 | 1.450 | |||
| Trockensubstanz (105°C) [Gew.-%] | 62.1 | 61.3 | 65.0 | |||
| Messung mit RFA [Gew.-%] (Schmelzaufschluss) | SiO2 | 45.0 | 44.7 | 47.9 | ||
| K2O | 0.3 | 0.3 | 0.4 | |||
Manufacture of dispersion from precipitated sulphuric acid
General equipment needed:
Double-walled vacuum-tight stirring tank with a cooling jacket and stirrer, e.g. slow-spinning anchor stirrer with a 5 to 10 kW stirring power motor Cooling unit for cooling the reactor jacket Heating water or steam generator for heating the reactor jacket Vacuum pump capable of producing a vacuum up to about 100 mbar, preferably < 100 mbar, e.g. water ring pump oil slide pump or vacuum venturi pump Inline homogeniser and/or ball mill
The double-coat is used for the flow of heating/cooling water and holds a volume of about 50 litres of cooling water in a 200-litre tank to allow for rapid cooling. The stirring unit consists of a slow-spinning anchor stirrer, adjustable to a speed of 1 - 85 rpm. The stirring unit was driven by a 2.2 kW motor.
To observe the individual changes and conditions, a stirring vessel with a view window and lighting was selected.
The heating unit consisted of a flow heater with a power of 21 kW and a flow rate of 40 1/min.
The cooling unit consisted of a 25 kW flow cooler and a 125 litre cold water tank to allow very rapid cooling of the reactor medium.
The vacuum pump was selected, which operates on a compressed air basis with a venturi system, which allows a very large (air volume-related) and very high vacuum level of about 70 mbar to be achieved.
An inline homogeniser with a powder inlet, e.g. a disperser from Fa. Ystral GmbH, Wettelbrunner Str. 7, D-79282 Ballrecht-Dottingen, type Conti TDS 2, with a power of 5.5 to 6.5 kW, a working speed of 6000 rpm, a working temperature of up to 70°C and a maximum concentration of insoluble solids of 60%, or a nanomill/ball mill, e.g. the ZETA@ RS nanomill from Netzsch, was used. An MS splitting ball mill 18 or MS 32 or MS 50 from FrymaKoruma would also be suitable.
30.9% by weight of water demineralized < 10 μS Conductivity 19.6% by weight of glycerol (anhydrous) 48.2% by weight of SiO2 Powder BET 50-60 m2/g Primary particles 40 nm0.5% by weight of KOH (50% by weight of water demineralized < 10 μS Conductivity) 0.8% by weight of polydimethylsiloxane
Water, glycerin, siloxane and KOH were introduced into the mixer, resulting in a pH > 10.5 The mixer was heated to 40°C. The mixture was stirred at 50 U/min for about 10 min. The liquid phase was then pumped into the circulation by stirring it through a dispersing apparatus, adding SiO2 continuously via an inline homogenizer or a nanomill/ball mill, continuously drawing the powder into the liquid stream through a side channel and infusing it with the disperser (disperser in the disperser or balls) under the mill. The final concentration was dispersed in the circulation until the pulse was completely homogeneous, which was achieved in the particle size.During the final dispersion, the current intake of the dispersant was increased and the temperature increased. The temperature was kept at about 40°C by cooling. The current intake was kept constant at about 35 A, which was taken as a measure for a homogeneous dispersion. The mass was then stirred for 2 hours under vacuum at 40 °C at 5 U/min. The reactor was then cooled down to 20 °C and, if necessary, the pH value was set with KOH to about 10.5 - 10.9. The dispersion was filled under filtration by a 100 μm bag filter in 1000 1 plastic binders, especially IBC.
A sample was taken as a residue sample and for analysis and the stirring container was cleaned.
Manufacture of a protective layer from the dispersion, as shown in example 2
The dispersion described above was mixed with KOH (50% by weight in demineralized water of conductivity < 10 μS) to form a protective layer dispersion of the composition:
Other
| 34.52 Gew.-% | |
| 36.99 Gew.-% | |
| Glycerin: | 14.39 Gew.-% |
| KOH: | 13.71 Gew.-% |
| Dimethylpolysiloxan: | 0.58 Gew.-% |
Stir-fryer vacuum-tight with a cooling/heating mantle
Heating unit for heating the reactor mantle
Refrigeration unit for cooling the reactor mantle
Vacuum pumps capable of producing a vacuum < 100 mbar
Other, of a kind used for the manufacture of motor vehicles
50% KOH50 % water demineralized < 10 μS
The reactor was cooled to 40-45°C, vacuum sealed and a vacuum of about 50 to 90°C. The temperature was maintained at a very low temperature in the specified upper vacuum range of about 45 to 40°C, so that the mixture could be cooled and air blows used to disperse the air. The vacuum was maintained for about 45 to 30 minutes and the mixture was then cooled to 60 to 60°C. The heat was maintained for about 30 minutes to achieve a very fast reaction rate, thus ensuring that the mixture could be re-mixed at about 5 to 30 mbar.
This protective layer was used to produce fire-test glasses with dimensions of 120 cm x 220 cm and a 5 mm ESG/6 mm ESG/5 mm ESG lens.
Further process for the manufacture of a fireproof coating of precipitated sulphuric acid according to the invention
(a) Silica dispersion consisting of:
47% by weight (solid) SiO219,6% by weight of glycerol0,5% by weight of siloxane 0,6% by weight of KOH32,3% by weight of water demineralized conductivity < 10 μSb) Kalilages consisting of:50% by weight of KOH50 by weight of water demineralized < 10 μSb
The mixture was presented with 73.45% SiO2 dispersion. The stirrer was turned on and set to about 50 U/min. Then 26.55% potassium eye was added at 50% (lasting about 5 min). The SiO2 and the potassium eye reacted to a highly viscous cream under stirring. After about 15 min a maximum temperature of about 50 - 60 °C should have been reached. If this temperature was not reached by the exothermia of the mixture, it was heated. The viscosity in this interval decreases to about 50 mPa.
The reactor was then vacuum sealed and the vacuum pump was switched on. At a pressure of 50 to 90 mbar, a stirring rate of 5 U/min and a temperature of 40-45 °C, the reactor contents were kept boiling for 15-45 min, so that the air in the material was expelled by means of gas bubbles.
After about 15-45 min, the reactor was cooled to 20-25 °C with cooling water as quickly as possible to slow down the solidification reaction and achieve a processing time of 3 h. The vacuum was maintained for about 60-90 min at a temperature of 20-25 °C and a stirring rate of 5 U/min to ensure bubble-free.
The resulting mixture was well suited to the production of fire-resistant elements.
This protective layer was used to produce fire-test glasses with dimensions of 120 cm x 220 cm and a 5 mm ESG/6 mm ESG/5 mm ESG lens.
Further process for the production of a fireproof coating of precipitated sulphuric acid with the addition of ammonia according to the invention
Silica dispersion consisting of: 47% (solid content) SiO219,6 % Glycerin0,5 % PDMS0,6 % KOH32,3 % Water demineralized by conduction < 10 μS
50% KOH50 % water demineralized < 10 μS
32 % NH368 % water demineralized < 10 μS
A mixture of 73% w/o2 dispersion and 0.5% w/o ammonia solution was introduced into a reactor at 32% and the stirrer was switched on and adjusted to about 50 U/min. Then 26.5% w/o potassium eye was added at 50%. This mixture reacted to a highly viscous cream under stirring. After about 15 min a maximum temperature of about 45-50°C was reached. Under heating the mixture was brought to 50-60°C; the viscosity dropped to about 50 mPa. This process of mixing and heating without vacuum should take about 15-45 min.The mixture was then cooled very quickly to 20-25°C to slow the curing reaction and achieve a processing time of 3 h. The vacuum was maintained for about 60 min at a stirring speed of 5 U/min to ensure bubble-free. The viscosity now reached about 150-250 mPa, but increased slowly over time. The mixture was suitable for disposal of fuel elements.
Surprisingly, the addition of ammonia solution after applying a vacuum was found to reduce bubbles on the surface of the mixture and to reduce boiling compared to the mixture without ammonia, thus reducing process time and increasing efficiency while improving optics.
This protective layer was used to produce fire-test glasses with dimensions of 120 cm x 220 cm and a 5 mm ESG/6 mm ESG/5 mm ESG lens.
Manufacture of a protective layer using a pebble salt.
500 ml round flask, fitted with a magnetic stirrer as a reaction vessel.
Heated and cooled water bath.
Glass circulator, attached to the cylinder and fitted with a 500 ml cylinder as a receptacle.
Vacuum pump connected to the reaction cylinder.
The vacuum pump used was compressed air based with a venturi system, which would achieve a very large (air volume-related) and very high vacuum level of about 70 mbar.
Silica salt consisting of:50% by weight (solids) SiO2 BET 50 m2/g and a primary particle size of 55 nm50 by weight of water demineralized conductivity < 10 μS,
For example, it is available from Fa Obermeier under the name Levasil 50/50
Other, of a kind used for the manufacture of motor vehicles
50% by weight of KOH50 by weight of demineralized water < 10 μS
Siloxane: Polydimethylsiloxane (PDMS), 50/50 aqueous emulsion (i.e. 50% by weight of polydimethylsiloxane and 50% by weight of water)
A magnetic stirrer was turned on and stirred for about 5 min to obtain a homogeneous liquid. A water bath was heated to about 45-50 °C under stirring, the vacuum pump was turned on and a vacuum of 50-90 mbar was generated. The mixture was then removed by boiling 17.1% water. The water loss was determined by condensing the water vapor in the return cooler and collecting it as water in a round column.
The silica-containing mixture and the potassium eye reacted to a highly viscous cream under stirring. After about 15 min, a maximum temperature of about 45-50 °C was reached. Under heating, the mixture was brought to 50-60 °C and the viscosity decreased to 50 m after about 15-30 min. This process of mixing and heating without vacuum was to take about 15-45 min.The temperature of 40-45 °C was maintained at a vacuum of about 50-90 mbar for 15-30 min, so that the reactor contents settled and the air in the material was expelled by means of gas bubbles. It was found that under these conditions gas bubbles were forcefully pushed to the surface and exploded.The stirrer was turned off, the vacuum pump was turned off and the reaction pump was vented.
The initial viscosity of 150-250 mPa gradually increased over time.
These results were confirmed in a 20 litre reactor and a sample disc measuring 50 cm x 50 cm was produced for fire tests.
This sample of glass, measuring 50 cm x 50 cm and with a glass structure of 5 mm ESG/6mm protective layer/5mm ESG, was subjected to a fire test according to EN 1363 and 1364 respectively.
The results of the analysis shall be presented in the form of a statistical analysis of the chemical composition of the product.
Manufacture of silicon dioxide dispersion containing precipitated silica
32.3% by weight of demineralized water < 10 μS Conductivity 19.6% by weight of glycerol (anhydrous) 47.0% by weight of SiO2 powder BET 50-60 m2/g; primary particles average about 40 nm0.6% by weight of KOH0.5% by weight of defoamer (polydimethylsiloxane)
The water, glycerin, de-foaming agent and KOH were introduced into a clean stirring vessel. A pH of > 10.5 was obtained. The mixture was stirred at 50 U/min for about 10 min. Then SiO2 was added via an inline homogenizer or a nanomill/ball mill and continued continuously while the mixture was pumped into the circulation. The current intake of the disperser device increased to about 35 A and the energy temperature also increased through the KOe inlet. Therefore, the reactor temperature was kept at about 40 °C by cooling. The material was passed through the disperser in the circulation until the current intake was constant.
If desired, the product can be filled in a storage container by filtration with a 100 μm bag filter, preferably with a sample taken as a residue sample and for analysis.
The empty stirring container should preferably be cleaned immediately.
Manufacture of striped glycerin-containing pebble salt
100 % Silica (levasil 50/50 of the company with a BET of 50 m2/g and a mean primary particle size βe of 55 nm)
in relation to the 100% solvent sample:
Glycerin (excluding glycerol)
The silica (levasil 50/50), glycerin and polymethylsiloxane were placed in a clean stirring vessel or reactor, heated to 60-70°C and stirred at 50 U/min for about 15 min. The reactor and column were then vacuumed (preferably < 100 mbar). The distillation column was set without feedback and 17.1% of the water in the solvent sample was evaporated. The vacuum was removed, the reactor was relaxed and cooled to 20 °C.
The pH was adjusted to about 10.5 - 10.9 by KOH if necessary, and a sample is usefully taken as a residue sample and for analysis.
If desired, the product can be filled in a 50 μm bag filter in a storage tank or left in the reactor for direct processing (see example 7C).
If the mixing tank is emptied, it is preferable to clean it immediately.
Preparation of a dispersion containing silica salt and precipitating sulphuric acid of a composition of 47,0% SiO2 19,6% Glycerine
50 per cent modified silica salt as described in example 7B50 per cent silica dispersion as described in example 7A
The modified silica salt produced in accordance with example 7B and the silica acid dispersion produced in accordance with example 7A were presented in the stirring vessel and circulated through the dispersion apparatus at 50 U/min for 1 h, maintained at a temperature of about 40°C.
Preferably a sample is taken as a back-up sample and for analysis.
The dispersion was filled into a storage container, e.g. an IBC container, under filtration by a 50 μm bag filter.
Silica dispersion as described in Example 7A and modified silica salt as described in Example 7B as specified in Table 2 and containing 0,5% by weight of PDMS each
7.4 kg of KOH (50% by weight in water)
As described in example 7C, further mixtures with different proportions of precipitated sulphuric acid dispersion to silica salt were produced in accordance with Table 2 and, after addition of the 7.4 kg KOH, used for the manufacture of protective layers or fire glass (type EI 30 120 x 220 cm 5mm ESG 6mm IL).
No further water was added and curing took place over 8 hours at 80°C. The visual assessment of the cured glass and the results of the fire tests are summarised in Table 2.
| 0.0 kg = 0% | 4.85 kg = 25 % | 9.75 kg = 50 % | 14.55 kg =75 % |
| 19.5 kg = 100% | 14.55kg = 75 % | 9.75 kg = 50% | 7.85 kg = 25 % |
| 19.8°C | 20,7°C | 19.2°C | 19.2°C |
| OK keine Blasen | OK keine Blasen | OK keine Blasen | OK kleine Blasen verschwinden nach 3-5 Tagen |
| sehr gut füllbar | sehr gut füllbar | sehr gut füllbar | sehr gut füllbar |
| Topfzeit 6 h | Topfzeit 5.5 h | Topfzeit 5 h | Topfzeit 4 h |
| 15 Min. | 30 Min. | 33 Min. | 34 Min. |
While the present application describes preferred embodiments of the invention, it is clear that the invention is not limited to these and can be implemented in other ways within the scope of the following claims.
Claims (15)
- Method for producing a protection layer of translucent heat-protection elements, characterised in that(a) a SiO2-dispersion stabilized with glycerine and/or ethylene glycol and KOH of(i) precipitated silica or(ii) pyrogenic (fumed) silica and/or precipitated silica and silica sol and(b) caustic potashare mixed with one another.
- Method according to claim 1, characterized in that the SiO2-dispersion stabilized with glycerine and KOH is a dispersion of pyrogenic silica and/or precipitated silica and silica sol.
- Method according to claim 1 or 2, characterized in that the SiO2-dispersion and/or the caustic potash contains alkylsiloxane in such amounts that the entire amount in the protection layer is between 0.1 and 10 % by weight, the alkylsiloxane being chosen from polymonoalkylsiloxanes and polydialkylsiloxanes and their mixtures, wherein the alkyl groups are linear and/or branched C1-C4-alkyl groups.
- Method according to claim 3, characterized in that the alkylsiloxane is polydimethylsiloxane.
- Method according to claim 3 or 4, characterized in that the alkylsiloxane has a molecular weight (Mw) in the range of 1000 to 25000.
- Method according to one of the preceding claims, characterized in that the SiO2-dispersion and/or the caustic potash contains ammonia in an amount corresponding to an amount of 0.1 to 6 % by weight of a 32 % by weight aqueous ammonia solution, particularly 0.5 to 2.5 % of a 32 % by weight aqueous ammonia solution.
- Method according to one of the preceding claims, characterized in that the SiO2-dispersion is a dispersion of precipitated silica and silica sol.
- Method according to one of the preceding claims, characterized in that the SiO2-dispersion has the following composition:35-52 % by weight SiO230-50 % by weight water0.6 ± 0.1 % by weight KOH0-13 % by weight alkylsiloxanethe rest glycerine and/or ethylene glycol, wherein at least 5 % by weight glycerine and/or ethylene glycol are contained, and wherein the alkylsiloxane is chosen of polymonoalkylsiloxanes and polydialkylsiloxanes and their mixtures, and wherein the alkyl groups are linear and/or branched C1-C4-alkyl groups.
- Method according to claim 8, characterized in that the SiO2-dispersion has the following composition:47.0-48.5 % by weight SiO233.8-30.9 % by weight water0.6 ± 0.1 % by weight KOH0-10 % by weight alkylsiloxanethe rest glycerine and/or ethylene glycol, wherein at least 5 % by weight glycerine and/or ethylene glycol are contained.
- Method according to claim 8 or 9, characterized in that the dispersion contains 0.5 to 0.8 % by weight alkylsiloxane .
- Method according to one of the preceding claims, characterized in that(a) the SiO2-dispersion stabilized with glycerine and KOH and(b) the caustic potashare mixed with one another in amounts corresponding to 70 and 75 % by weight of a dispersion of one of the claims 8 to 10 and 25 and 30 % by weight of caustic potash (50 % by weight), particularly preferred in amounts corresponding to 73.45 % by weight of a dispersion of one of the claims 8 to 10 and 26.55 % by weight caustic potash (50 % by weight).
- Use of a silica sol stabilized with KOH and polyol for producing a protection layer of a heat-protection element.
- Aqueous dispersion containing silicon dioxide, characterized in that it contains (i) pyrogenic silica and/or precipitated silica and (ii) silica sol and in that it is stabilized by addition of polyol and alkaline hydroxide, particularly potassium hydroxide.
- Method for producing a stable and concentrated silica sol, characterized in that polyol is added to an alkali-stabilized silica sol, whereafter it is concentrated by water evaporation.
- Translucent heat-protection element with at least a carrier element and a protection layer, characterized in that the protection layer is an aqueous silicate composition, obtainable from alkali metal oxide and SiO2 by the method according to one of the claims 1 to 11.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| WOPCT/CH2008/000292 | 2008-06-26 | ||
| PCT/CH2008/000292 WO2009155714A1 (en) | 2008-06-26 | 2008-06-26 | Materials for producing transparent heat protection elements and light protection elements produced using such materials and also processes for producing them |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| HK11102952.9A Addition HK1148712B (en) | 2008-06-26 | 2009-06-19 | Materials for producing transparent heat protection elements and light protection elements produced using such materials, and method for the production thereof |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| HK11102952.9A Division HK1148712B (en) | 2008-06-26 | 2009-06-19 | Materials for producing transparent heat protection elements and light protection elements produced using such materials, and method for the production thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| HK1181006A1 HK1181006A1 (en) | 2013-11-01 |
| HK1181006B true HK1181006B (en) | 2014-03-21 |
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