HU209963B - Process for producing of porous materials from closed gascell graired silicates - Google Patents

Abstract

0-90 vol.% of a mixt. of water soluble silicates, heat softening/hardening silicates or non-silicate based industrial binder, resins, metal alloys, natural or synthetic glue, ceramic oxides, clay, fire resistant paint and mortar is mixed with the closed gas cellular granules. The mixt. is bound together either chemically, or thermally or by pressure.

Description

FIELD OF THE INVENTION The present invention relates to a process for producing porous materials from closed gaseous particulate silicates having excellent thermal and acoustic, heat-resistant and refractory properties and extremely low bulk density. The porous materials of the present invention can be advantageously used in many fields of industry and public use as good sound and heat insulating materials of reduced density (mortar, clay, ramming, ceramic, plastic, resin, rubber, refractory paint, paste, etc.). ).

It is known that the best thermal and acoustic insulation properties are provided by materials (natural or synthetic) which do not have a homogeneous structure but contain gas inclusions and gas bubbles in the form of closed pores. Of particular interest are those sound and heat insulating materials which are generally considered to be of general application, particularly for use in thermal applications, which in practice means that the sound and heat insulating properties of the material are practically independent of the thermal effects of the environment. Solutions that utilize the poor thermal conductivity of glass or glass-like materials, natural silicates, e.g. they prefer to use basalt, glass or asbestos thermal insulation. Thermal insulation up to a certain temperature can also be achieved using plastic foams (eg polyurethane foams, polystyrene foams)

- and, in the case of the latter, adequate sound insulation

- to reach. However, the design of complex substructures precludes the use of most insulating materials, particularly at higher temperatures and higher quality requirements.

It is well known that many other solutions are used primarily in the construction industry (eg so-called, lightweight concrete or lightweight masonry units), but these are only temporary solutions. They alleviate wall loads to some extent, but they also result in a reduction in the sound and heat insulation properties of the product due to the high amount of binder required by the technology.

Perlite is the most well-known additive in this category of insulation and masonry materials, for which many products are used. Such a product is described, for example, in U.S. Patent No. 2,703,342. U.S. Patent No. 4,400,111, which relates to mortars for the application of thermal insulating sheets, which may contain, in addition to hydraulic binders, fillers, cellulose derivatives, alkali-resistant plastics, surfactant protective colloids, perlite. Perlite natural is a perlite mineral swollen by conventional technology.

However, a major disadvantage with conventionally swollen perlite is the fact that the granular material almost explodes during the swelling process during swelling, and therefore has open pores resembling porcine, with consequently reduced thermal and acoustic properties, and it will be highly hydrophilic and absorbent. As a result, the thermal and acoustic insulation properties of the expanded perlite continue to deteriorate from the moment of installation.

In the known manufacturing technologies, commercially available open-pore, expanded pearlite (e.g., Pl, P2, P3, Pálháza) is commonly used. Due to the open structure of the expanded perlite, it is only able to reduce the bulk density of the particular binder (gypsum, cement, vinyl, polystyrene, PVC, etc.) in this product, since the binder penetrates into the open pores of the perlite particles. the binder content will be high. The absorbent property of the initial swollen perlite also limits the amount of perlite additive that can be mixed. so e.g. In the case of hydraulic binders (gypsum, cement, lime, or mortar), the maximum amount of perlite that can be mixed is 15-17% by volume. (For example, in Albafal ^R formulations, perlite content of 5-10% and high water content is not advantageous for masonry interiors.) Open porous, expanded pearlite particles have low intrinsic strength, due to amorphous particle structures. This fact also greatly limits the possible perlite content of a given mixture.

It is an object of the present invention to overcome the above disadvantages by providing low density, excellent heat and sound insulation porous materials which are versatile.

The present invention is based on the discovery that by using a closed-cell gas-cellular perlite (silicate) instead of open-pore perlite particles to produce the aforementioned materials, a material with a much more advantageous property can be created since the closed gas cell structure of perlite prevents granules and displace the gas needed to reduce the bulk density.

The amount of mixed gas cellular perlite that can be mixed in the product according to the invention can also be significantly higher (up to 90%) than that of open-pore perlite, and thus the higher perlite content advantageously influences the properties of the resulting product. so e.g. the volume of the binder is significantly reduced, its thermal, acoustic and electrical insulating properties are increased, and the fire and flammability properties of the product are significantly improved (especially for plastic-based binders). Closed gas cell particles are close to spherical in shape and have considerable intrinsic strength, so a larger proportion can be applied to a particular composition without weakening the structural member. SUMMARY OF THE INVENTION The present invention relates to a process for preparing porous products from particulate silicates and binders by mixing, homogenizing, hydraulically bonding the starting materials or optionally heat treating and / or pressing; ben formatting or shaping, which. characterized in that the hydrophilic or hydrophobic closed gas-cellular particulate silicate, preferably perlite, having a bulk density of 0.05-0.20 kg / l, a particle size range of 0.01-9.00 mm and a strength of 1.5-50 kp / cm 2,

- with hydraulic binders in an amount of between 5% and 90% by volume,

with plastic based binders in quantities of 1 to 90% by volume, or

mixed with other binders (such as clay, ramming material) in an amount of 10-60% by volume and optionally 1-50% by volume with additives, fillers and / or propagating agents.

The closed gas cellular silica silicate used in the process of the invention, preferably perlite, is prepared by pre-treating the natural silicate with an initial particle size of 2-1500 μιη, preferably 300 μιη at 50-800 ° C and optionally chemically treating it at the specified temperature. within a range of limits, directly and / or directly heated to a heat treatment space of 800-5000 ° C, preferably 800-3000 ° C, with a discharge temperature of 800-2000 ° C, uniform, 0.1-1200 kg / h / m ³ , preferably 0.5 to 500 kg / h / m ³ , to form a closed gas cellular material having a density of 0.12 to 2.7 g / cm ³ and a volume of 0.05 to 1.6 kg / l it is collected, collected, removed from the heat treatment space and, if desired, surface treated. By this method, the density of the final product can be adjusted to the desired and required value within the specified density range or bulk density range. The surface of the granules may be regarded as a chemically inert melt, the physicochemical properties of which may be adjusted, if necessary, by prior and / or subsequent surface treatment. For example, the particles can be made hydrophobic by treatment with, for example, silicone oil.

In the process according to the invention, a closed gas cellular particulate material, preferably perlite, prepared as described above, is used as starting material, the main parameters of which are as follows:

- bulk density

- particle size range

- strength

0.05-0.20 kg / l 0.01-9.00 mm 1.5-30 kp / cm ²

- heat and refractory properties

- nature

It softens at 800-1000 ° C, is hydrophilic without melting, can be made more hydrophilic by treatment.

Because of its closed gas cell structure, the above perlite can be well mixed with hydrophilic or hydrophobic materials in a hydrophilic version. It has a shrinkage coefficient below C of the order of magnitude of the shrinkage coefficient of the glass.

The binders used in the process of the invention may be hydraulic binders such as cement, gypsum, lime, mortar; plastic-based binders such as resins, synthetic resins, thermoplastic materials, thermosetting plastics;

raul volume%, preferably in the case of materials is from 1 to 4% by volume, other types of rope by volume, preferably from 20 to 50% by volume.

The production of cellular products for builders _ _ _h plastic industry, ceramic industry, etc. known technologies.

It is preferred that the resulting product be formed at the same time as the bonding and consolidation. A target 15 is also the solution when the product is formed after the bonding. It may be advantageous to carry out the process wherein the resulting product is surface-treated and / or coated after bonding, consolidation.

In the case of hydraulic binders, the product of the process (with or without suitable element forms) can be advantageously used as masonry material, partition walls, air walls, lightweight partitions, slab insulations, exterior and interior cladding, various applications, tampons, etc. making. Swabs are consistent versions of the exemplary products that fill the available space before solidification.

If plastic binders are used, the plastic may be maintained as a continuous phase. By using up to 65-70% by volume of particulate silicate, the plastic is thus lightened and, at the same time, its impact and wear resistance (mechanical strength) is increased. By using a higher filler content (6535 90% v / v), the original properties of the closed gas cell particles become dominant, i.e. the silicate character of the lighter system becomes dominant.

In our experience, the most commonly used thermoplastic plastics (eg PVC, Polyethylene, Po40 Purifier, etc.) are capable of absorbing up to 65-90% by volume of closed gas cellular particulate material while maintaining the plastic phase. If the bulk density of the enclosed bubble particulate material is 0.061.0 g / l, the original density of the plastics 45 g (0.91 to 1.45 g / cm ³ ) may be reduced by 10-70%. depending on the quantity. The flammability of plastics can also be significantly reduced.

The same is true for clays (kaolinite, vermiculite, nontronite, illite, montmorillonite, etc.), which have a medium density of 2.40 g / cm ³ , with a mixture of 10-60% v / v of a closed gaseous particulate material of 1 g / cm ^3. can be reduced below this value without degrading the strength and firing properties and greatly improving the insulation (thermal and acoustic) properties.

If clay, clay minerals or other materials (for example, ramming or alumina) are used above 45% by volume, the continuous phase will be the clay or ceramic phase, while 5 to 30% by volume of clay will be used.

HU 209 963 Β will be a consolidation function, and the properties of the closed gas-cell particles will dominate the character of the product.

With clay, clay minerals, ramming masses, etc. In the case of mixing, when the proportion of the closed gaseous particulate material in the mixture is in the range of 10-60% by volume, preferably 1045% by volume, rams, mortars, special heat-resistant masses, heat-resistant paints, heat-resistant pastes, etc. have very advantageous properties. which can be produced by molding, casting, mixing, patching, etc. By burning such masses, excellent thermal insulation coatings and other products can be produced, which have the great advantage of low weight (low bulk density), good strength and good thermal insulation.

The resulting products may, if desired, be pre-treated and / or coated before and / or after bonding, consolidation.

Various additives, fillers, and propagating materials can be mixed in amounts of from 1 to 50% by volume with the above granular and binder blends to increase the strength, impact resistance and abrasion resistance of the porous products of the present invention. As additives, in particular glass fibers, graphite, graphite fibers, plastic fibers, metal fibers, netting thereof, fabrics or various particulate materials such as rock chips, ceramic chips etc. we can use it.

The porous materials containing the closed gaseous particulate silicate produced by the process of the present invention have the following advantages:

- self-supporting and capable of being shaped by solidification, pre-consolidation or subsequent low-energy mechanical processing;

- excellent thermal, acoustic and electrical insulating properties;

- closed pores have very low moisture absorption capacity;

- putty, paintable, with spreading materials, foils, etc. they have a coating that allows for additional wrapping solutions;

- they have a low bulk density and are therefore ideal for, for example, airplanes;

- their surface can be made more hydrophobic by suitable treatment.

Further advantages of using a closed gas cellular particulate material are that

- Provides favorable physical properties of the product, even at high admixture ratios, against previously known insulating and filler materials;

- improves the heat resistance and reduces the thermal conductivity of the product in the case of plastic and clay binders; significantly increases both strength and wear resistance in plastics and rubbers; improves the drying and firing properties of clay and special masses;

miscible with both hydrophilic and hydrophobic binders;

- the closed gas cellular material is made from domestic raw material and its use is economical due to the favorable physical parameters obtained with its help;

- the technology for implementing the process can be easily implemented and incorporated into the technologies already known.

The invention is illustrated by the following non-limiting examples.

A) Manufacture of products containing hydraulic binders

EXAMPLE 1 85% vol. 0.08 kg / l closed gas cell perlite was mixed with Portland cement at a volume of 2.7 kg / l. The mixture is homogenized and then added with the amount of water known in the art and in the literature to hydraulically cement the cement and allowed to solidify under atmospheric conditions. Curing can be accelerated by evaporation. The product will have a bulk density of 0.47 kg / l, lightweight and good heat and heat insulator. Its thermal conductivity is λ = 0.045 kcal / mh ° C.

Example 2

For construction gypsum, 50% v / v of a closed gas cell stock having a volume of 0.08 kg / l, this mixture is homogenized, then the amount of water corresponding to the gypsum is added to the system and allowed to solidify as desired. The material thus obtained will be 40% less by volume than the starting gypsum.

Instead of forming, the homogenized aqueous mixture may be applied.

Example 3

In the case of mortars, when the requirement for the mortar to be applied is low volume, for example half of the original mortar, to mix a known volume and a conventional mortar with 65% by volume of closed-cell perlite of 0.06 kg / l, homogenize and apply to the desired surface in the usual manner. The resulting mortar has a 48% increase in thermal insulation capacity and a 50% reduction in volume compared to the original mortar.

Example 4

When using a water-soluble silicate binder, add 5-10% v / v sodium metasilicate, traditionally water glass with a SiO ₂ content of 25% v / v, to 0.05 kg / l closed gas cell perlite and homogenize the mixture. , optionally, and allow to stand for 30 hours while the product solidifies. The cure time can be reduced by injecting carbon dioxide gas into the system. The material thus obtained is not only excellent insulating material, but can also be used at high temperatures (600-700 ° C).

(B) Process for the manufacture of products based on plastic-based binders

Example 5

A volume of 0.08 kg / l of perlite in a closed gas cell is added in an amount of v / v to a two-component, room temperature-curing, 1.3 kg / l volume of epoxy resin such as araldite. This, after homogenization, gives a low bulk density material with a high impact and abrasion resistance of 35% lower by volume compared to the resin used.

Example 6

In the case of thermoplastic (thermoplastic) plastics, for example, prior to the process, to a granular polyethylene having a density of 0.98 g / cm ³ , 70% by volume of a closed gas cellular material with a volume of 0.06 kg / l is homogenized and then at elevated temperature. (about 80 ° C) and pressurized.

The product obtained has a bulk density of 0.5 kg / l and has significantly higher impact strength, abrasion resistance and significantly lower flammability than the original polyethylene.

Example 7

In the case of the use of thermosetting plastics as binders, for example, a volume of 0.055 kg / l of closed gas cellular perlite is added to 45% by volume of commercial bakelite powder. After homogenization, the system is solidified using the generally known technology for solidifying the vinyl powder using the appropriate temperature (200-250 ° C) and pressure. The material thus obtained will have a volumetric mass of 35% less than that of the original vinyl record, and its heat resistance will be considerably higher.

Example 8

1.1 kg / l PVC is mixed with 5% v / v of 0.05 kg / l closed gas cell perlite. After homogenization, the mixture is liquefied under appropriate temperature and pressure and then solidified.

The resulting product has a bulk density of 1.04 kg / l and does not ignite below 250 ° C.

(C) Process for the manufacture of products made with other binders

Example 9 45

When using a clay binder, the clay is mixed with 55% (v / v) 0.08 kg / l of closed gas cell perlite, homogenized according to known procedures and then, after desiccation, consolidated by heat treatment (800-1200 ° C). The resulting brick has a bulk density of 1.1-1.25 t / m ³ . Even at 30% vol / vol closed gas cell perlite, the brick had a flexural strength of 148 kg / cm ² , which is well above the class I brick strength requirement (100 kg / cm ² ). And its heat-insulating properties are close to those of commercially available expanded perlite.

Example 10

Rammering masses containing 8-95% A1 ₂ O ₃ 60

bv ____ runk e », produced by Ma _fc .

sonmagyaróvár), also containing additives gat weight, closed gas cell sc.

homogenize, then formatting, experience, spray, etc. put on the.

and consolidation by desiccation and / or heat treatment.

The heat-insulating capacity of the material thus obtained is increased by 35% and the volume by 40% relative to the original material.

Example 11

For example, in the production of oxide ceramics, 50% v / v of closed gas cell perlite (0.05 kg / l) is added to pure alumina powder, the mixture is homogenized, and after molding is fired at 2000-2050 ° C. The resulting material will have a bulk density of 2.0-2.2 kg / l as opposed to an original volume of 4.0 kg / l.

D) Preparation of Porous Materials Containing Additive

EXAMPLE 12 50% vol. 1.8 kg / l ceramic flour was added as an additive to a closed gas cellular particulate material having a volume of 0.08 kg / l and Portland cement at a volume of 40% by volume, 2.7 kg / l. After homogenization and addition of the required amount of water, allow to solidify. The product obtained has a mass of 2.0 kg / volume.

Example 13 10% by volume of a 1.5 kg / l volume of epoxy resin, preferably araldite, was mixed with v / v of closed gas cellulite with a volume of 0.05 kg / l and glass fiber with a volume of 2% by volume of 2.2 kg / l. Upon curing, a non-flammable material having a volume of 0.22 kg / l is produced which has the thermal insulation properties of commercial perlite. λ = 0.04.

EXAMPLE 14 20% by volume of rock slurry, followed by 35% by volume of 1.3 kg / l of epoxy resin, preferably araldite, are mixed as a growth additive to a closed gas-cellular particulate material of a volume of 0.05 kg / l. After curing, the resulting product weighed 0.90 kg / l.

Claims (5)

PATENT CLAIMS A process for preparing porous products from particulate silicates and binders by mixing, homogenizing, hydraulically bonding or optionally heat treating and / or pressing the starting materials and optionally shaping or shaping the hydrophilic or hydrophobic closed gas cell. particulate silicate, preferably perlite, having a bulk density HU 209 963 Β 0.05-0.20 kg / l, grain size range 0.019.00 mm, strength 1.5-30 kp / cm ² , - with hydraulic binders in an amount of between 5% and 90% by volume, plastics - based binders in quantities of 10% to 90% by volume, or - mixed with other binders in an amount of 10-60% by volume, and optionally in an amount of 1-50% by volume with additives, fillers and / or propagating agents. Process according to claim 1, characterized in that the hydraulic binder is Portland cement, gypsum, lime, mortar or water-soluble silicate. The process according to claim 1, wherein the plastic-based binder is selected from the group consisting of epoxy resin, polyethylene, polystyrene, PVC, resin, synthetic resin and vinyl. The process of claim 1, wherein the other binder is clay, metal oxide based ramming compound, alumina or clay mineral. 5. A process according to claim 1, wherein the additive, filler, propagating material is ceramic powder, metal, graphite, glass, plastic fiber, mesh, fabric or stone chips or ceramic powder.