DE2329378C3 - Curable mixtures of substances based on an aqueous solution of water glass containing lithium aluminum silicate - Google Patents

Description

The invention relates to curable compositions which can be used as binders, adhesives and / or coating materials suitable.

Water glass, such as sodium silicate, is generally an excellent inorganic binder known, but it has the disadvantage that it is not resistant to moisture. Numerous efforts were therefore aimed at imparting water resistance to the binder.

From US-PS 32 22 197 inorganic coating agents are already known which are composed of alkali silicates and Lithium aluminum silicates exist as pigments, with water serving as a dispersing medium. This However, coating agents still have considerable disadvantages, since they are used as coating material the applied layers both with prolonged treatment with water at room temperature and dissolved and peeled from the surface after treatment with warm water for only a few hours became.

Surprisingly, it has now been found that these disadvantages eliminated and products of high Hardness, water resistance, incombustibility and fire resistance can be obtained if as Lithium aluminum silicate natural petalite or spodumene modified by heat treatment or whose mixture is used.

The invention thus provides suitable hardenable mixtures of substances as binders, adhesives and / or coating materials based on an aqueous solution of water glass containing lithium aluminum silicate, which are characterized in that they are powdery petalite and / or spodumene fired ^{at temperatures above 1000 ° C. as lithium aluminum silicate} contain.

The compounds petalite and spodumene commonly found in nature have the following Key figures:

Spodumene is mostly obtained in nature as ^ -Spodumene. It will be at a temperature above 1000 C

roasted, the conversion into / J-spodumene takes place. Petalite turns into a mixture of /? - spodumene and SiO ₂ when it is fired at temperatures above 1000 C. The compounds obtained by firing petalite and Λ-spodumene at temperatures above 1000 ^{c C}

fertilize are as hardness components of the invention Mixtures of substances effective.

The water glass used in the present invention is not limited, but are generally aqueous solutions of alkali silicates, such as

Sodium silicate, potassium silicate or lithium silicate, preferably in a molar ratio of SiO ₂ to alkali metal oxide of 2: 1 to 4: 1. The concentration of the alkali silicate solution can be in a wide range, because the viscosity of the water glass by

Changing the molar ratio of SiO ₂ to alkali metal is greatly changed, but for ease of handling the solution preferably contains the alkali silicate in an amount of 20 to 50 percent by weight, calculated as the solids content.

Petalite and spodumene are the more reactive the smaller their particle size is, but one becomes Particle size of not more than 100 μ is preferred, since with particle sizes over 100 μ the reactivity is a little lower. The lower limit is

, 50 about 1μ.

In the substance mixtures according to the invention, the water glass and the petalite and / or spodumene have preferably the following proportions:

»5 water glasses (50% aqueous solution) 100 parts

Petalite and / or spodumene 300 bis

10 parts

lio The substance mixtures gradually harden by themselves normal temperature, but they are preferably subjected to a heat treatment at 100 to 300 ° C, thereby giving them excellent water resistance.

The mixtures of substances according to the invention can be used as film-forming compounds or embedding compounds will. When used as a coating material, such as Üoerzugssassen and paints, these

adjusted to an optimal viscosity by adding water and then by methods such as Spray, roll, brush or trowel applied. In this case, the mixtures of substances can contain fillers may be added to improve the properties of the paint film.

The compositions of matter according to the invention have excellent adhesion to the material to be coated Underlay and form a dense and strong film. You can use a wide variety of materials, such as aluminum, iron, wood. Synthetic resin or ceramic.

The mixtures of substances according to the invention can also be used as binders for aggregates during manufacture used by refractory bricks and insulating blocks will. In this case, the aggregate whose grain size has been adjusted becomes a A suitable amount of the mixture of substances is added, whereupon the mixture is pressed and the pellets longer than 30 minutes to temperatures above 200 "C, whereby a rigid, hard, water-resistant Product is obtained which can be used directly as an unfired brick. the Mixtures of substances according to the invention can also be used as binders for gluing, for example Asbestos sheets, concrete or various stone materials can be used.

example 1

Natural petalite and natural spodumene were held for 4 hours at 1100 C and ^c aui a particle size of less than 74 μ milled. The powder was mixed with water glass in the following proportions, whereby the substance mixtures (A) and (B) were obtained:

Mixture of substances (A)

Na ₂ O 3SiO ₂ (40% aqueous solution

suns) 100 parts

Petalite, fired at 1100 ° C

100 parts

Mixture of substances (B)

Na ₂ O · 3SiO.> (40% strength aqueous solution) 100 parts

Spodumene, 100 parts fired ^{at HOO 0 C}

These mixtures were applied to glass plates, baked 60 minutes at 100 ~ C and 30 minutes at 200 ^c C. The films obtained were homogeneous ceramic films with no bubbles or cracks. They have been tested for water resistance. The results are given below.

Stuffed Treatment Film after the treatment mixture conditions Status Pencil- of the film would have Films

(A) 30 Taee in water normal 9 H (20 ^c C)

4 hours in normal 9H

hot water

(8O = C)

(B) 30 days in water normal 9 H (2O ⁰ C)

4 hours in normal 9H

hot water

(8O ⁰ C)

Example 2

110 parts of quartz sand with a grain size of 2.0 to 5.0 mm and 20 parts of that prepared according to Example 1 Mixture A were mixed. The mixture became a cylinder 3 cm in diameter and 3 cm high.

The molding was held for 60 minutes at 100 "C and then dried for 30 minutes at 200 ⁰ C to form a cured molded article was obtained, the 30 days was kept in water at 20 ° C, where it does not coincide, and showed excellent water resistance.

The pencil hardness mentioned in the examples were made according to the scratch test described in Japanese Industrial Standard JIS K 54C0 with pencils using the scoring tool described in Japanese Industrial Standard JIS K 5401 for Scratch test determined with pencils.

Comparison tests

Mixtures of 100 parts of Na _s O 3SiO ₂ (solids content 40%) and the hardness components listed in the table below in the amounts specified there were applied as a coating material to a glass plate, then at 100 ° C. for 60 minutes

dried and finally heat-treated at 200 ° C. for 30 minutes. The tested water resistance each sample is also mentioned in the table.

The compositions of matter according to the invention are because of their water resistance and resistance as well as their Fire resistance as a binder, adhesive and / or coating material ideally suited and can be used for various purposes.

5 Mixture of substances 100 parts si 100 parts (f
H in Wassei from
80 "C for 4 hours Water glass 23 29 378 Wasserbesländigkejt the dipped the same the same in water of
20 ⁰ C for 30 days no ver
modification sample Na ₂ O-3SiO ₂
Solids content submerged 40% the same Hardness component desgi. no
modification the same the same According to the
invention the same Burned petalite
at 1100 ° C the same the same Shift was
solved and the same the same the same peeled off According to the the same Burned spodumene the same the same the same invention the same at 1100 ^° C the same comparison the same the same unfired
Petalite the same the same the same the same Shift was
solved and
peeled off comparison the same unfired
Snodumene the same the same the same U.S. PS
32 22 197 the same ZrSiO ₄ U.S. PS the same ZrO ₂ the same the same the same 32 22 197 the same U.S. PS the same Al ₂ O ₃ 50 parts the same the same 32 22 197 the same the same 10 parts U.S. PS CaSiO ₃ the same the same 32 22 197 the same the same U.S. PS the same TiO ₂ no ver
modification 32 22 197 the same comparison Si comparison Na ₂ SiF ₆

Claims (3)

Patent claims: 1. As a binder, adhesive and / o
Layering material suitable curable
Mixtures based on an aqueous solution of water glass containing lithium aluminum silicate, characterized in that they contain, as lithium aluminum silicate, pulverulent petalite and / or spodumene which are fired ^{at temperatures above 1000 ° C.} 2. Mixtures of substances according to claim 1, characterized by a proportion in parts of Water glass to petalite and / or spodumene in the range from 100: 300 to 100: 10. 3. Mixtures of substances according to claim 1 or 2, characterized by petalite and / or spodumene powder with grain sizes from 1 to 100 μ. 23 29 378 2 Li, O content General Shape! 3.5 to 4.5%
4.0 to 7.5% Li ₂ OAl ₂ O
Li ₂ OAl ₂ O ■ ₃ -8Si0,
3 · 4SiO ₂ the loading
Sloff- 5 Petalite
Spodumene For example, petalite has the following chemical composition: LuO ⁴ - ²⁷ % Al ₂ O ₃ ¹ week SiO ₂ 76.16% Fe ₂ O ₃ 0.04% Na ₂ O 0-53% K, 0 0.62% CaO 0.21% MgO °> ²⁴ %