RU2408639C1 - Adhesive composition (and versions thereof) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: adhesive compositions (versions thereof) contain amorphous silica with dispersion of 1-5 mcm, 1-200 mcm, silica-containing aggregate with SiO₂ content not less than 60%. In one version, the aggregate can be sand. In another version, the aggregate is granite powder. In one version, the adhesive composition contains sodium silicofluoride and possibly a plasticiser. In other versions, the composition contains an alkali-containing component in form of a hydrate of sodium oxide or caustic soda. All compositions are hardened with water. One of the versions of the adhesive composition uses silica-containing binder with initial density of 1.5-1.7 g/cm³, which is increased to 1.34-1.36 g/cm³.

EFFECT: obtaining compositions which are insoluble in water, are water resistant, alkali- and acid-resistant and have good strength properties.

5 cl, 1 tbl

Description

The invention relates to adhesives and can be used in the chemical industry and the building materials industry, in particular when gluing ceramic tiles, or of natural stone, or other facing materials to concrete and plaster surfaces of walls, ceilings, floors, with interior and exterior decoration of housing and public buildings, as well as for decorative finishing and corrosion protection of various surfaces.

Numerous adhesive compositions and compositions for coatings based on liquid glass (sodium silicates or potassium silicates) are known, containing various fillers and other target additives used for gluing parts made of metals, ceramics, glass (Petrova A.P. Heat-resistant adhesives. - M .: Chemistry, 1977, p. 160-161).

Adhesive compositions containing alkali metal silicates are known. So, the composition according to the patent of the Russian Federation No. 2088622, C09J 1/02, C04B 28/26, 1997, includes, wt.%: Water glass 11-35, fine quartz sand 31-60, aggregate 10-50, graphite or sulfur 2- 6. This material has insufficient strength and water resistance.

Known mineral glue for ceramic products, containing, wt.%: Water glass 45-55; kaolin 5-35; porcelain powder 10-25 and alumina - the rest.

However, this glue is used mainly in the electronics industry in the manufacture of glued ceramic products and includes high-temperature processing of products, which results in high strength properties (firing at 900-1380 ° C), (SU 1481223, 05.23.1989).

From SU 1728277, 04/23/1992, an adhesive composition based on 60-80 wt.% Sodium liquid glass with a density of 1.1-1.2 g / cm ³ and a module of 2.0-2.5 as an active filler of 20-40 wt. .% clay diatomite Vorotan deposits with a specific surface area of 2400 cm ² / g

However, to ensure the water resistance of the adhesive joint, heat treatment at 200 ° C is necessary.

From RU 2280057, a composition for bonding lightweight concrete is known, including liquid sodium glass, a polymer additive - divinyl styrene latex, a hardener - sodium remnefluoride and a finely divided powder filler, while it contains hydrolyzed lignin powder as a finely divided powder filler.

However, this composition is prone to premature coagulation, resulting in a weakening of the adhesive properties of the composition.

So, from RU 2131447, 06/10/1999, an adhesive composition is known, including liquid sodium glass of 38-42 wt.% As a binder, filler - marble flour 34-36 wt.%, Sodium sulfide 2 wt.% And talc - the rest. This adhesive composition glues a wide range of materials, such as metal, wood, ceramic tiles, silicate glass, linoleum.

This adhesive composition using liquid glass as a binder has a number of significant disadvantages:

low water resistance, as upon curing of sodium liquid glass, water-soluble compounds are formed;

low stability of viscous and adhesive properties during storage. This is due to the use of sodium sulfide in the composition, which, during prolonged storage of the adhesive composition under conditions of fluctuating temperatures, initiates the crystallization process, as a result of which the viscosity of the composition increases, and its separation into liquid (liquid glass) and solid (marble flour) phases occurs. This circumstance leads to a violation of the reproducibility of the strength properties of the adhesive joint.

From the prior art it is known to improve the adhesive and other physico-chemical and physico-mechanical properties of the silicate binder by varying the introduction of various target additives in the adhesive silicate binder during its preparation and in the composition based on it.

So, from SU 1156809, 05.23.1985, a composition is known comprising liquid glass, mainly sodium glass with a silicate module of 2.6-3.0 and a density of 1470-1500 kg / m ³ , silica gel (a waste product of superphosphate containing 5-6 wt. .% alumina, 0.7-0.8 wt.% iron oxide, 2-3 wt.% aluminum fluoride, silicon dioxide - the rest), inorganic pigment (lead oxide or titanium dioxide) and a surface additive from the group comprising aluminum powder, fine carbon, bentonite, asbestos. The introduction of silica gel helps to prevent cracking of the film and to reduce the duration of the curing of the composition, however, the resulting film does not have water resistance and is washed off with water for 30 seconds. This composition is mainly used to restore the tightness of porous castings from ferrous and non-ferrous metals.

Another composition is known from SU 1422641, 01/10/1996, including liquid sodium glass with a density of 1.25-1.28 g / cm ³ - 25.0-30.0 wt.%, Aerosil - 0.1-1.0 wt. %, carboxymethyl cellulose 0.5-1.5 wt.% and zinc powder 67.5-74.4 wt.%. The known composition is intended to obtain an anti-corrosion coating for the protection of various metal structures and relates to the so-called zinc protective coatings. The composition cures for a long time (within 7 days) after processing the applied composition with a hardener with a solution of calcium chloride.

It is known to improve the water and weather resistance of a film formed from a composition based on a silicate binder (liquid glass) with a module of 2.8 and a specific gravity of 1.18-1.2 g / cm ³ by introducing aluminosilicate-perlite and oligomethyl hydridesiloxane GKZh- 94M and lead oppression in the following ratio of components, wt.%:

Liquid sodium glass 100.0 Lead Depression 0.5-1.5 1 Perlite-80 one hundred; Oligomethyl Hydride Siloxane 2-3

(SU 1773923 A1, 11/07/1992)

The composition is prepared by sequential mixing of the components: first, perlite is mixed with lead oppression, then the mixture is closed with liquid glass, and GKZh-94M hydrophobizing organosilicon liquid is added. The composition when applied has good adhesion to concrete and forms a fairly waterproof coating, but is not used as an adhesive and its main high physical and mechanical properties are ensured through the use of a large amount of perlite (aluminosilicate) and organosilicon liquid.

Known adhesive composition EP 0041212, 12/09/1981, comprising an aqueous solution of sodium silicate with a mass ratio of SiO ₂ / Na ₂ O (mass module) of 2.6-3.9: 1 and / or an aqueous solution of potassium silicate with a mass ratio of SiO ₂ / K ₂ O (mass module) 2-2.6: 1, as well as 25-50 wt.% Finely dispersed (1 to 45 μm) crystalline calcium carbonate in the form of metamorphic calcite, 2-10 wt.% Quartz flour with a particle size up to 15 microns and a developed specific surface area of at least 3.5 m ² / g. Additionally, the adhesive composition contains up to 24 wt.% 50% stable aqueous dispersion of an organic polymer selected from the range of acrylate, styrene acrylate and / or styrene butadiene. To improve water resistance, up to 2 wt.% Lithium hydroxide is added to this adhesive composition.

This adhesive composition is mainly used in industry for gluing mineral fiber tiles and has a number of significant disadvantages:

- low adhesive strength (at the level of 0.5-0.6 MPa);

- low viability and stability during storage. Calcium carbonate in the environment of aqueous solutions of sodium and / or potassium silicates exhibits high reactivity, which leads to thickening and subsequent curing of the adhesive composition. All this violates the stability of viscous and adhesive properties for a short time after the manufacture of the adhesive composition, and therefore, complicates its use during prolonged storage;

- toxicity of the components of the adhesive composition. This is because organic polymer dispersions (acrylic, styrene, styrene acrylic, butadiene) contain monomer residues (1-2%) and synthesis catalysts (0.1%), stabilizers (0.5%), and organic solvents (2- 5%);

- low heat resistance. This is due to the fact that even at temperatures of 300-400, calcium carbonate decomposes with the release of calcium oxide and carbon dioxide, which leads to the destruction of the adhesive.

Many of these disadvantages are deprived of the known adhesive compositions described in US 3721574, 08/06/1968 and RU 2205851, 10.06.03.

US 3721574 describes a composition intended for the manufacture of adhesive coatings that dry in air and have increased water resistance, chemical resistance, and corrosion resistance due to the use as a silicate binder of a binder consisting of a combination of an aqueous solution of alkali metal silicate (lithium, sodium or potassium) and colloidal silicon dioxide in the form of an aqueous dispersion of a silicate salt, mainly an aluminum salt or in the form of a solution of metasilicic acid, which ensures a certain pH of it (pH 10-11) and elations SiO _2: Me ₂ O in the final binder (from 5: 1 to 6.5: 1). In order to improve certain properties of coating films based on this binder, various target additives are introduced into the composition, for example, polytetrafluoroethylene (for chemical resistance), zinc powder is used to obtain corrosion-resistant coatings, various organosilanes (difunctional and trifunctional), for example, dimethyldimethoxysilane, are introduced to increase hydrophobicity. arylalkoxysilanes and others. To prepare the binder, alkali metal silicate with a silicate module of 3.5-4.0 is used.

RU 2205851 describes an adhesive composition that contains as a binder the product of the interaction of an aqueous solution of potassium silicate and anhydrous lithium hydroxide in a mixture with di- or trihydric alcohol or a mixture thereof, wollastonite, talc and inorganic pigment, while the initial potassium silicate is used with a density 1.30-1.37 g / cm ³ , with a molar silicate module 3.4-3.7, the initial wollastonite - with a particle size of 150 μm or less and a length to diameter ratio of 5-3: 1, in the following ratio starting components, wt.%:

The above wollastonite - 38.0-45.0

Talc - 8.0-12.0

Anhydrous lithium hydroxide - 1.0-1.5

Di-, trihydric alcohol or a mixture thereof - 3.0-5.0

Inorganic pigment - 3.0-5.0

The above potassium silicate solution is the rest.

Thus, the silicate binder in this known composition is a complex product of the interaction of an aqueous solution of potassium silicate with anhydrous lithium hydroxide in a mixture with its constituent components.

The binder and composition are prepared as follows. In a first step, anhydrous lithium hydroxide is added in portions to an aqueous solution of potassium silicate. Stirring of each portion is carried out until the lithium hydroxide particles are completely dissolved (disappeared) and an interaction product is obtained into which di- or trihydric alcohol or a mixture thereof (for example, ethylene glycol, glycerin) is introduced in portions and a mixture of the first stage product with alcohols is obtained. Then, a portion of wollastonite and a portion of talc are simultaneously introduced in portions into this mixture simultaneously and mixing is carried out until a homogeneous product is obtained. In the last step, an inorganic pigment is introduced. The adhesive composition is poured and stored in sealed containers.

This well-known adhesive composition can significantly expand the range of glued materials, for example concrete, ceramics wood (oak, beech, conifers), marble, steel, glass, as well as their various combinations with the formation of a durable and waterproof adhesive joint, however, it has a number of significant disadvantages :

limited water resistance, as the binder contains a di-, trihydric alcohol or a mixture thereof, which is highly soluble during prolonged exposure to water;

- low level of strength (not more than 0.87 MPa of adhesive bonding to certain types of surfaces (wood, glass, steel);

- low stability during prolonged storage due to sedimentation of fillers, which leads to separation into liquid and solid phases, which in turn leads to a violation of the reproducibility of the strength properties of the adhesive joint;

- low thermal stability due to volatility and decomposition at 300-400 ° C,

used in binder organic alcohols.

The practical use of this adhesive composition is very limited due to the use of only potassium silicate as a binder, which is 3-4 times more expensive than the corresponding sodium silicate, and also due to the use of specific wollastonite with a strictly regulated particle size of 150 microns and a ratio of length to diameter of 5 -3: 1.

The technical task of the claimed invention is to improve the water, acid and alkali resistance of the composition, expanding technological capabilities in the field of its application and expanding the range of production of inexpensive adhesive products for widespread use in industry.

The stated technical problem is achieved by the claimed group of inventions relating to the options for adhesives based on amorphous silicon

Thus, the stated technical problem is achieved by the adhesive composition containing a binder (binder) based on amorphous silica with a dispersion of 1-200 μm, a silica-containing aggregate with a SiO ₂ content _of at least 60%, an alkali-containing component, a crystallizer - sodium silicofluoride, possibly superplasticizer and water in the following the ratio of the starting components in wt.%:

amorphous silica 18.5-41.2 specified silica-containing aggregate 41.2-73.9 alkali-containing component 1,5-5,0 sodium silicofluoride 0.05-1.0 superplasticizer 0-0.5 water rest

the ratio between the silica-containing aggregate and amorphous silica is 1: 1-1: 4.

As a superplasticizer, the composition contains, in particular, a C-3 superplasticizer based on sodium naphthalenesulfonates.

The technical task is also achieved by the adhesive composition containing a dry mixture consisting of amorphous silica with a particle size of 1-5 μm, dried granite powder with a moisture content of 3-4% and a particle size of 5-20 μm, a dry alkali-containing component in the form of sodium hydroxide or caustic soda, and water for mixing the dry mixture in the following ratio of starting components in wt.%:

Amorphous silica 41.0-41.5 the above granite powder 41.0-41.5 alkali-containing component 1.0-1.3 water rest

In addition, the technical task is also achieved by another variant of the adhesive composition and the method of obtaining it included in the claimed group of inventions, namely, an adhesive composition containing a silica binder with an initial density of 1.5-1.7 g / cm ³ and module 2 , 7-3,2, amorphous silica with a dispersion of 1-5 microns, sand with a dispersion of 40-60 microns in the following ratio of the starting components in wt.%:

Specified silica binder 21.0-22.0 Specified Amorphous Silica 26.0-26.5 Sand 52.0-52.5

As well as a method for producing an adhesive composition, including diluting with water a silica binder with an initial density of 1.5-1.7 g / cm ³ to a density of 1.34-1.36 g / cm ³ and introducing it into a pre-prepared homogeneous mixture containing amorphous silica with a dispersion of 1-5 microns and sand with a dispersion of 40-60 microns, their subsequent mixing until a homogeneous pasty mass to a certain consistency with a spreadability of 60-80 mm

To obtain the adhesive composition according to the above variant of the claimed group of the invention, a silica-containing binder (binder) is used as a silica binder, for example, obtained and described in RU 2283818, 09/20/2006, which is obtained from a mixture containing an inorganic binder, a silica-containing component and water with intensive mixing in a high-speed mixer with a stirring speed of 1500-2500 rpm, an oscillation frequency of the mixed particles of 2000-35000 Hz, heating to 80-90 ° C and then cooling it stirring at from 40 to 100 rev / min for 10-12 hours at 15-25 ° C. As well as a silica binder, obtained and described in RU 2236374, 09/20/2004 based on an inorganic binder, silica-containing raw materials and water by mixing them. In this case, a silicate bond or an alkali metal or ammonium hydroxide is used as an inorganic binder, a silica-containing raw material with a moisture content of not more than 6%, with a content of SiO ₂ > 50 wt.% With a particle size of from 0.5 to 2.0 is used as a silica-containing material. mm or pre-crushed to a particle size of 40 A to 50 μg, fresh water, marine or mineralized, is used as water, while mixing is carried out in a high-speed mixer with a stirring speed of at least 2000 rpm, a count frequency REPRESENTATIONS stirred particles 3500-30000 Hz and the mixing time from 20 minutes to 10 hours to a density of 1.2-2.2 g / cm ^3, with the following component ratio of the initial mixture, wt.%:

The above silica-containing raw materials 15-65

Silicate bond or alkali metal or ammonium hydroxide 5-30

Fresh water, sea or mineralized 30-62.5.

As a silica-containing binder in the adhesive composition according to the 3rd embodiment of the claimed group, a silica-containing binder can be used, for the preparation of which a separate application No. 2009121120 of 03.06.2009 has been submitted.

This binder is obtained on the basis of an inorganic binder, a silica-containing component, and water with vigorous stirring in the presence of hydrofluoric acid salt (in an amount of from 0.5 to 10.0 wt.%) Per mixture.

As an inorganic binder, an alkali metal hydroxide, or ammonium, or a silicate binder is used, as a silica-containing component, a silica-containing component with a particle size of from 0.2 to 20.0 mm or pre-crushed to a particle size of from 40 A to 60 μm, selected from of a group including quartz sand or quartz flour with a moisture content of not more than 4%, quarry clays with a moisture content of more than 10%, burnt clays, loams, sandy loams, loess deposits, silica fume obtained from ferroalloy production wastes c, stone processing waste obtained during sawing or grinding, for example, granite, or in the production of crushed granite, hydromica, such as that used in the production of vermiculite or expanded perlite, while intensive mixing is carried out in a high-speed mixer with a stirring speed of 1500-6000 rpm , the vibration frequency of the mixed particles 2000-45000 Hz at 80-90 ° C or when exposed to an electric field with a voltage of 15-40 W and a current strength of 60 A, and mixing is carried out for a period of time from 10 min to 12 aces depending on the dispersion of the silica-containing component, after which the mixture is cooled with constant stirring at a speed of 40 to 100 rpm at 15-25 C for 10-12 hours or using air aeration at 10-20 ° C for 6 -11 hours to obtain a binder with a density of 1.3-2.4 g / cm ³ and a silicate module of 15-30 with the following ratio of components of the initial mixture in wt.%:

the above inorganic ligament 5.0-30.0 the above silica-containing component 15.0-65.0 hydrofluoric acid salt 0.5-10.0 water rest.

So, according to the first embodiment of the claimed group of the invention, the adhesive composition is prepared as follows.

So, the adhesive composition consists of a silica-containing component (aggregate) with a SiO ₂ content _of at least 60%, a fraction of 1.0-60.0 microns, amorphous silica (natural minerals, for example tripoli, flasks or industrial wastes, for example silica fume - metallurgy waste) an alkaline component, for example sodium hydroxide and water.

The ratio of aggregate and amorphous silica is in a ratio of 1: 1-1: 4. The alkaline element is introduced in an amount of from 0.5 to 5 wt.%, Water - 12-20 wt.%. To reduce water consumption, you can enter up to 1 wt.% Plasticizer, for example C-3. To accelerate the setting, 0.2-1 wt.% Of the mold is introduced into the adhesive, Na ₂ SiF _6, or the surface of the glued product is heat treated at a temperature of 45-100 ° C for 1.5-3 hours. The resulting adhesive composition has a density of 1.62-1.64 g / cm ³ . As a silica-containing aggregate, the composition contains, for example, a waste of processing granite with a fineness of 5.0-20.0 microns.

According to a second embodiment of the claimed group of the invention, the adhesive composition is prepared as follows.

The dry adhesive mixture has, for example, the following composition:

Dried granite powder, waste grinding granite slabs, fractions 5-20 microns, 41.2 wt.%;

Amorphous silica, for example, industrial silica fume fractions 1-5 microns, 41.2 wt.%

Dry alkali-containing component, for example caustic soda, 1.2 wt.%.

The components are mixed dry and packaged, for example, in paper bags with a polyethylene liner or in plastic containers with a tightly fitting lid.

Before starting work, the dry mixture is closed with 16.4 wt.% Water and mixed mechanically, for example in a mortar mixer, until a homogeneous pasty consistency is obtained. Let the mass stand for 10-20 minutes, then mix again. The adhesive is ready to go. It has the same properties as that made on the basis of a silica binder, according to one of the variants of the claimed group of the invention.

According to a third embodiment of the claimed group of the invention, the adhesive composition is prepared as follows. The composition is prepared using a silica binder (binder) obtained according to the specified well-known patent RU 2283818.

The binder is adjusted to a density of 1.35 g / cm ³ by diluting it with water.

Dry components: sand, fractions of 50 microns, 52.2 wt.% And amorphous silica, for example tripoli, fractions of 1-5 microns, 26.1 wt.%, Are mixed, for example, in a planetary mixer, until a homogeneous mass is obtained. A binder, 21.7 wt.%, Is introduced into it. Mixing is carried out until a homogeneous pasty consistency with a spreadability of 60-80 mm is obtained. The finished adhesive is packaged in a plastic container, for example tubes or faith with a volume, for example from 0.5 to 5 liters, with tightly fitting lids. Shelf life, in containers without air access - 1 year. Before starting work, the adhesive composition is mixed and applied to one of the surfaces to be glued with a layer of 3-4 mm. The seam thickness is 1-2 mm. The setting time of the composition is 3-4 hours, the complete crystallization of the adhesive for 7 days at a temperature of 18-25 ° C. To accelerate full crystallization, the surface of the glued product, such as ceramic wall tiles, is subjected to heat treatment of 45-100 ° C, for example, an air heat gun, 1.5-3 hours. After this time, the complete crystallization of the adhesive composition will occur and it becomes insoluble water, acid and alkali resistant.

All adhesive compositions (options) for this claimed invention are obtained using inexpensive and non-deficient raw materials. All of them have sufficiently high water resistance properties (insoluble in water), alkali resistant, acid resistant. They have good strength properties.

The table below shows examples of adhesive compositions according to the invention and their properties.

Adhesive compositions according to the invention and their properties. Name of components, properties The content of the components of the composition according to examples 1 Amorphous silica with dispersion (tripoli) - 40-50 microns 20,0 - - - 1-5 microns - 41.2 26.1 - 100-200 microns - - 2 Alkali-containing component - sodium oxide hydrate 2.0 1,2 - 3 Silica-containing aggregate with a content of SiO ₂ not less than 60% 40,0 - - 4 Silica-containing binder with an initial density of 1.7 g / cm ³ - -one 21.7 5 Quartz sand with a dispersion of 40-60 microns - - 52,2 6 Granite powder with a moisture content of 4% and a fineness of 10-20 microns - 41.2 - 7 Sodium silicofluoride 0.5 - - 8 Superplasticizer C-3 0.2 - - 9 Water Rest Rest Rest Adhesive Properties: - viability min. 90 90 90 - adhesion, MPa 1.2 1.2 1.2 - water absorption% 6 6 6 - frost resistance F100 F100 F100 - shelf life month eighteen eighteen eighteen - mark on mobility P3 P3 P3 - compressive strength M150 M150 M150

Claims (4)

1. An adhesive composition containing a binder (binder) based on amorphous silica with a fineness of 1-200 μm, a silica-containing aggregate with a content of SiO _{2 of} at least 60%, an alkali-containing component, a sodium silicofluoride crystallizer, possibly superplasticizer and water in the following ratio of the starting components in wt. .%:
Amorphous silica 18.5-41.2 Specified Silica Aggregate 41.2-73.9 Alkali-containing component 1,5-5,0 Sodium silicofluoride 0.05-1.0 Superplasticizer 0,0-0,5 Water rest 2. An adhesive composition containing a dry mixture consisting of amorphous silica with a particle size of 1-5 μm, a dried powder with a moisture content of 3-4% and a particle size of 5-20 μm, a dry alkaline component in the form of caustic soda or caustic soda, and water for mixing dry mix in the following ratio of starting components in wt.%:
The above amorphous silica 41.0-41.5 The above granite powder 41.0-41.5 Alkali-containing component 1.0-1.5 Water rest 3. An adhesive composition containing a silica binder with an initial density of 1.5-1.7 g / cm ³ and a module of 2.7-3.2, amorphous silica with a dispersion of 1-5 microns, sand with a dispersion of 40-60 microns in the following the ratio of the starting components in wt.%:
Specified silica binder 1.0-22.0 Specified Amorphous Silica 6.0-26.5 Sand 2.0-52.5 4. The method of obtaining the adhesive composition according to claim 3, comprising diluting with water a silica binder with an initial density of 1.5-1.7 cm ³ to a density of 1.34-1.36 g / cm ³ and introducing it into a previously prepared homogeneous mixture, containing amorphous silica with a dispersion of 1-5 microns and sand with a dispersion of 40-60 microns, their subsequent mixing to obtain a homogeneous pasty mass to a certain consistency with a spreadability of 60-80 mm.