WO1996038396A1

WO1996038396A1 - Agent for impregnating stone and shaped stonework or for the production of modelable compounds and compounds containing said agent and mineral solids

Info

Publication number: WO1996038396A1
Application number: PCT/AT1996/000101
Authority: WO
Inventors: Adolf Goll
Original assignee: Stonetec Anstalt/Stonetec Establishment
Priority date: 1995-06-02
Filing date: 1996-06-03
Publication date: 1996-12-05
Also published as: AU5805296A

Abstract

The proposal concerns an aqueous agent for impregnating and preserving stonework which contains at least one inorganic silicon compound and, according to the invention, consists of a water-based electrolyte-containing, acid alkaline metasilicate solution. Preference is given to sodium metasilicate and above all potassium metasilicate. The agent contains alkaline metal salts or ammonium salts as the electrolyte. The acid is a strong one, preferably hydrosilicofluoric acid. The pH is preferably raised to up to 2.5 by the addition of ammonia solution. To construct mineral-based mouldings, granular and powdered mineral solids are added to a corresponding solution and made into a compound which slowly hardens on being left to stand.

Description

Means for impregnating stone and shaped bodies made of stone or for producing modeling clay and modeling clay which contains this agent and mineral solids

The present invention relates to an agent for the impregnation or preservation of stone and of shaped articles made of stone, in particular plastic stone formations which are exposed to the weather, or a means for producing modeling clay for building shaped articles on a mineral basis, which agent comprises one or contains several inorganic silicon compounds.

In particular, it is an object of the present invention to provide a means with which both protection of new stone structures and preservation of existing, possibly already attacked stone structures is achieved.

Another object of the present invention is a modeling clay for the restoration of stone material, with the aid of which moldings based on minerals can be built up or additions made to stone moldings. For both hobbyists and artists, this modeling clay is used to create a material that is suitable for repairing existing moldings as well as for putting creative ideas into practice.

Means of the type mentioned above as well as kneading compounds for the stated purposes have already been proposed.

Water glass solutions, aqueous solutions of fluates (= salts of fluorosilicic acid) and solutions of organic silicic acid esters for the preservation of stone material exposed to the weather have already been described and used.

Water glass is a relatively inexpensive material based on alkali metal orthosilicates, which is converted into SiO 2 and alkali carbonate after application by the carbon dioxide in the air. The resulting silica gel surrounds the stone surface and provides protection against further attack by the atmospheres. However, the conversion reaction mentioned proceeds very quickly, so that there is no great depth of penetration of the solution into the stone material. This is partly due to the high viscosity of the water glass solutions. The surface protection is therefore only noticeable to a depth of a few millimeters. The alkali carbonates formed at the same time are formed in relatively large quantities and represent a water-soluble undesirable by-product. Overall, the methods for stone preservation with the aid of water glass solutions were classified as inadequate decades ago.

As far as fluorosilicic acid and its salts are concerned, the magnesium salt MgSiFg, which has been mainly used up to now, also supplies silica gel, for example in limestone preservation, with calcium fluoride, magnesium fluoride and CO2 as by-products arise. There is no positive assessment of this salt as a stone preservative in the literature.

Preservation with silica esters is used most frequently nowadays, and it is stated that they also disintegrate to form silica gel SiO 2, the alcohols bound as esters being formed as harmless, soluble by-products. The poor depth of penetration observed in water glass solutions and the formation of by-products which damage the building structure - salts - are avoided with this process. Nevertheless, this method is not necessarily recommended by the experts, since a surface seal is created which prevents any breathing of the underlying material. A surface layer forms with the hydrophobic material, which subsequently shows even greater abrasion than before. Preservation over a period of more than about 20 years is not possible in this way.

In the course of diverse research, a new agent for the impregnation or preservation of stone material or for the production of modeling clay, which according to the present invention is characterized in that it consists of an electrolyte-containing, acidic alkali metal silicate solution on an aqueous basis, has now been found.

This agent is primarily suitable for the impregnation of silicate stone materials, although the treatment of lime materials such as marble is also possible.

The agent according to the invention is colorless and has a surprisingly high penetration depth of up to 3-4 cm. The pore compaction achieved and the associated surface compaction result in an excellent weather resistance on a stone surface treated with the agent according to the invention, which was not previously achievable. Even after a long time, no microcracks are formed, so that the preservation is extremely effective over long periods.

As alkali metasilicate, the agent primarily contains sodium metasilicate and / or potassium metasilicate, the formulas of which are given as Na2Siθ3 or ^ SK ^. The concentration of the alkali metal silicate is preferably 0.02-0.05 molar.

A mixture of sodium and potassium metasilicate has proven to be favorable for the impregnating agent.

Fluorosilicic acid, sulfuric acid, hydrochloric acid, nitric acid or formic acid is usually used as the acid.

The preferred acid for use in the agent of the invention is fluorosilicic acid.

The pH of the resulting solution is generally in the range from 1 to 4, the acidic ranges 1 to 2.5, preferably 1.5 to 2.2 being preferred for certain purposes, but in other cases the values being 2 to 4, especially 2 to 3 lead to better results. The new agent preferably contains one or more alkali salts, for example rock salt, or salts as the electrolyte, which originate from the fact that alkali carbonates or ammonia are added to raise the pH. In other embodiments, the agent contains copper sulfate in addition to or instead of alkali salts. The electrolyte concentration is advantageously 0.02-0.1, preferably 0.02-0.08, normal.

According to a particularly advantageous embodiment of the invention, the new agent is formed by mixing the following three batches in a volume ratio of approximately 1: 1: 1:

Approach 1: Aqueous solution of a strong acid with a normality of 0.4-0.5.

Batch 2: Aqueous solution of alkali metasilicate with a molarity of 0.09 - 0.13.

Batch 3: Aqueous solution of one or more alkali carbonates with a concentration of 1 g / 1 to 2 g / 1 and / or copper sulfate with a concentration of 1 g / 1 to 2 g / 1.

In some cases, batch 3 can be made from a rock salt solution with e.g. There are 8 - 12 g rock salt per liter of water.

For the impregnation or preservation of stone and moldings made of stone, the agent according to the invention is preferably formed by mixing the following batches in a volume ratio of 1: 1: 0.2: 0.8:

Approach 1: Aqueous solution of a strong acid with a normality of 0.4 to 0.5.

Batch 2: Aqueous solution of alkali metasilicate with a concentration of 5 to 15 g / 1.

Batch 3: Aqueous solution of copper sulfate with a concentration of 5 g / 1 to 10 g / 1 and / or potassium carbonate with a concentration of 5 g / 1 to 10 g / 1.

Batch 4: A: Aqueous solution of metasilicate, preferably potassium metasilicate with a concentration of up to about 11.5 g / 1 or

B: Aqueous silica gel solution with a concentration of 1.2 to 10 g / 1.

Batch 2 preferably consists of a sodium metasilicate solution.

To produce a modeling clay, batch 3 preferably consists of an aqueous solution of copper sulfate with a concentration of 1 g / 1 to 2 g / 1 and / or potassium carbonate with a concentration of 1 g / 1 to 2 g / 1.

The agent according to the invention preferably contains fluorosilicic acid, in particular in an amount of 28-34 g / 1, ideally about 31 g / 1.

Batch 2 preferably contains about 14 g / 1 sodium metasilicate.

It has been shown that applying the impregnating agent according to the invention not only provides protection for the surface, but also that the green algae, which practically always adhere to a stone material exposed to the weather and are at least as responsible for the destruction of the stone as the acid rain, the exhaust fumes etc. die off due to the action of the agent according to the invention and are subsequently washed away from the stone surface.

A major problem with stone renovation is not only the impregnation and preservation, but above all the build-up of plastic stone formations or the production of additions to them, since often smaller or larger parts of the stone structure are missing and must be replaced during restoration .

The invention therefore also relates to a plasticine for the construction of moldings on a mineral basis, which according to the invention consists of an agent mentioned above in a mixture with the following solid constituents:

65-80% by weight of granular material with a grain size of 0 to 2 mm, consisting of quartz sand and / or lime sand,

20 - 35% by weight of powdery material, consisting of quartz powder, limestone powder, powdered Jurassic lime, spade, diatomaceous earth, trass and possibly up to 10% by weight of cement.

If cement is added, the amount of sands is reduced by the amount of cement, the ratio of the sands to one another remaining the same.

Margaretener Sand has proven to be extremely cheap as a component of the granular material. Margaretener Sand is a material that occurs naturally in St. Margareten, Burgenland, Austria.

Preferably, a modeling clay for building shaped bodies on a mineral basis for hobbyists and artists consists of an above-mentioned agent in a mixture with the following solid components: about 2 parts by weight of granular material with a grain size up to 1 mm, consisting of lime sand, quartz sand and margareten sand and about 1 part by weight of floury material consisting of quartz powder, lime powder, flour from Jurakalk, heavy spar, diatomaceous earth, trass and cement.

Another preferred modeling clay for producing a stone substitute that can be modeled consists of an agent mentioned above in a mixture with the following solid components:

50 to 70% by weight of a granular material of grain size up to 2 mm consisting of lime and quartz,

5 to 10 wt .-% of a granular material with a grain size up to 1 mm consisting of Margaret sand and

20 to 30% by weight of floury material consisting of quartz powder, lime powder, flour from Jurakalk, heavy spar, diatomaceous earth, trass and cement.

Another preferred modeling clay consists of an agent mentioned above in a mixture with the following solid constituents: about 50 to 70% by weight of lime sand with a grain size of up to 2 mm, 5 to 10% by weight of margareten sand with a grain size of up to 1 mm,

20 to 30% by weight of floury material consisting of lime powder, flour from Jurassic lime, heavy spar, diatomaceous earth, trass and cement.

The sands preferably have a grain size of 0-2 mm, or 0-1 mm, in particular 0.5-1.5 mm.

The ratio of grain size 0-1 mm to grain size 0-2 mm is preferably about 1: 1, but any other mixing ratios can be selected depending on the requirements.

If appropriate, the modeling clay according to the invention can also contain about 2.5% by weight of water glass. However, it is emphasized that the stone moldings obtained from the modeling clay according to the invention are not cement-bound material, as is understood in the construction industry.

To produce the modeling clay, the liquid agent mentioned is processed with the solids in a weight ratio of about 1 part solution to about 4 to 6 parts solids. Depending on the composition, however, a different weight ratio may also be required in order to produce a kneadable mass from which stone structures can be formed or which can be used to build up and supplement missing stone parts. After shaping, the products can be placed outdoors after a short time to let them dry, where they slowly petrify. The increase in strength lasts for many weeks and reaches its maximum depending on the composition, sometimes only after one to two years. It can be beneficial to moisten the stone products temporarily or occasionally in the first period after shaping.

The solids advantageously contain 36-66% by weight of lime sand with a grain size of 0 to 2, 25-28% by weight of quartz sand with a grain size of 0 to 2, 4.5 to 6% by weight of quartz powder, 7 to 13% by weight of lime powder, 1.5 to 2.0% by weight Jurassic lime powder, 2.0 to 2.3% by weight spade powder, 2.2 to 2.8% by weight diatomaceous earth powder, 1.2 to 1.7% by weight % Trass powder, 5 to 9% by weight margareten sand 0-1 mm and optionally 2 to 10% by weight cement.

For indoor use only, in some cases where faster curing is desired, it may be beneficial to extend the aqueous solution up to about a quarter by an aqueous solution of sodium water glass and / or potassium water glass containing 3 - 3, 6% by weight of sodium water glass and 3 - 3.6% by weight) of potassium water glass.

The modeling clay according to the invention was deformed into numerous larger and smaller test specimens, left to harden and analyzed with regard to the mechanical properties which formed. It was found that the bodies formed had an extraordinarily high strength and that they gave a visual impression of natural stone, which suggests that stone blocks were produced in a similar way in prehistoric times. In this way, many puzzles with regard to the origin and transport of stone blocks among the indigenous peoples for whom no clarification has yet been found. Due to the slow hardening, there is no tendency to crack during petrification. This property is particularly important in the production of very large stone blocks and was extremely unexpected. In this way, blocks weighing several tons can be produced without any difficulties arising during curing.

The moldings obtained in this way are waterproof and can also be used under water after curing. They can be processed, sanded and cut with the appropriate tools and, depending on the choice of the starting material, have a shade of gray to warm yellow.

The following examples serve to illustrate the invention without restricting it:

Stone hardening agent:

Batch 1: 100 g of 34% by weight commercially available fluorosilicic acid ^ SiF ^ are added to 1 liter of water. The solution is stable and can remain as an approach.

Batch 2: 5 to 15 g of commercially available alkali metal silicate are dissolved in 1 liter of water. 14 g of sodium metasilicate are preferably added to 1 liter of water.

Batch 3: 1-2 g of copper sulfate and 1-2 g of potassium carbonate are dissolved in 200 ml of water.

Batch 4: up to 9 g of metasilicate, preferably potassium metasilicate, are dissolved in 800 ml of water or up to 9 g of silica gel, preferably as a silica gel solution, are dissolved in 800 ml of water.

These batches are mixed together in a volume ratio of 1: 1: 0.2: 0.8 and result in a durable, clear, colorless solution which is mixed with up to 40 ml of basic solution per liter of liquid to increase the pH. For example, an ammonia solution (12.5%, 0.29 N) is used as such. For example, 14 to 18 ml of this solution was added to achieve a pH of 2.02 to 2.13. However, a smaller amount of 25% by weight ammonia solution can also be used.

The resulting solution serves as an impregnating agent for the preservation or consolidation of stone formations.

Liquid for producing a modeling clay:

Batch 1: 100 g of fluorosilicic acid (34%) in 1 liter of water.

Batch 2: 14 g of sodium metasilicate in 1 liter of water.

Batch 3: 1-2 g of copper sulfate and 1-2 g of potassium carbonate in 1 liter of water. The pH increase can be carried out in a manner similar to that of the stone consolidation agent mentioned above.

A preferred solid mixture for producing a modeling clay has the following composition:

Lime sand 0-2 385 g

Quartz sand 0-2 275 g

Quartz flour 87 g

Lime flour 60 g

Jurassic lime 70 g

Spat 40 g

Diatomaceous earth 22 g

Draw 26 g

Margaret sand 0-1 15 g

Cement 20 g

In some cases it turned out to be advantageous to add up to 17 g of dry water glass to an above solid mixture.

About 1 part by weight of the above mixed solution from batches 1 to 3 was added to about 4-6 parts by weight of this solid mixture. Processing takes place by stirring and kneading until a plastically deformable mass is obtained.

The test specimens made from this modeling clay quickly become harder at first, but often reach their maximum strength after months or years.

The strength measurements initially showed values of up to 8 N / mm, which rose over time (after more than about 2 years) to 25 to 30 N / mm ".

In certain cases, the plasticine can contain marble as part of the granular material.

It preferably contains 2 to 10% by weight of cement and / or approximately 2.5% by weight of water glass.

For the modeling clay according to the invention, 1 part of solution with 4 to 6 parts of solids is processed.

The solids can preferably contain 36-66% by weight »lime sand 0-2.

In other compositions, the solids can contain 25-28% by weight quartz sand 0-2.

Likewise, the solids can contain 4.5 to 6% by weight of quartz powder and / or 7 to 13% by weight of lime powder and / or 2 to 4% by weight of Jurassic lime powder and or 2.0 to 2.3% by weight of spar powder , preferably feldspar or heavy spar and / or 2.2 to 2.8% by weight diatomaceous earth and / or contain 1.2 to 1.7% by weight of trass powder and / or 5 to 9% by weight of margareten sand 0-1.

Ash or oxidic pigments may be included to achieve color.

For indoor use, the aqueous solution can be up to about a quarter in size by a solution of sodium water glass and / or potassium water glass with a content of 3 - 3.6% by weight sodium water glass and 3 - 3.6% by weight potassium water glass be replaced.

Claims

claims

1.Means for impregnation or preservation of stone and moldings made of stone, in particular plastic stone formations which are exposed to the weather, or means for the production of modeling clay for building moldings on a mineral basis, which means contains one or more inorganic silicon compounds, since ¬ characterized in that it consists of an electrolyte-containing, acidic alkali metasilicate solution on an aqueous basis.

2. Composition according to claim 1, characterized in that it contains sodium metasilicate Na2Siθ3 and / or potassium metasilicate ^ SiO ^ as alkali metasilicate.

3. Composition according to claim 1 or 2, characterized in that the alkali metal silicate concentration is 0.02 - 0.05 molar.

4. Agent according to one of claims 1 to 3, characterized in that it contains fluorosilicic acid, sulfuric acid, hydrochloric acid, nitric acid and / or formic acid as the acid.

5. Composition according to one of claims 1 to 4, characterized in that it contains fluorosilicic acid as the acid.

6. Composition according to one of claims 1 to 5, characterized in that its pH is 1 to 4, preferably 1.5 to 2.2.

7. Composition according to one of claims 1 to 5, characterized in that its pH is 2 to 4, preferably 2 to 3.

8. Composition according to one of claims 1 to 7, characterized in that it contains one or more alkali salts and / or copper sulfate and ammonium salts as the electrolyte.

9. Composition according to one of claims 1 to 8, characterized in that the Elektro¬ lyt concentration is 0.02 - 0.1 normal, preferably 0.02 to 0.08 normal.

10. Composition according to one of claims 1 to 9, characterized in that it is formed by mixing the following three batches in a volume ratio of about 1: 1: 1:

Approach 1: Aqueous solution of a strong acid with a normality of 0.4 to 0.5.

11. Agent according to one of claims 1 to 9 for the impregnation or preservation of moldings made of stone, characterized in that it is formed by mixing the following batches in a volume ratio of 1: 1: 0.2: 0.8:

Approach 1: Aqueous solution of a strong acid with a normality of 0.4 to 0.5.

B: Aqueous silica gel solution with a concentration of 1.2 to 10 g / 1.

12. Composition according to claim 11, characterized in that it contains as an approach 2 an aqueous sodium metasilicate solution.

13. Composition according to one of claims 1 to 10 for the production of a moldable modeling clay, characterized in that batch 3 from an aqueous solution of copper sulfate with a concentration of 1 g / 1 to 2 g / 1 or an aqueous solution of copper sulfate and potassium carbonate with the concentration of 1 g / 1 to 2 g / 1 each.

14. Composition according to one of claims 1 to 13, characterized in that the approach 1 contains fluorosilicic acid, sulfuric acid, hydrochloric acid, nitric acid, formic acid as a strong acid.

15. Composition according to one of claims 1 to 14, characterized in that the approach 1 contains fluorosilicic acid as a strong acid.

16. Composition according to one of claims 1 to 15, characterized in that the batch 1 contains fluorosilicic acid in an amount of 28-34 g / 1, preferably about 31 g / 1.

17. Composition according to one of claims 1 to 16, characterized in that the batch 2 contains about 14 g / 1 sodium metasilicate.

18. Agent according to one of claims 1 to 17, characterized in that to achieve a pH of> 2 the addition of an aqueous ammonia solution, preferably an ammonia solution with 12 wt .-% to 25 wt .-% , contains.

19. Plasticine for the construction of moldings on a mineral basis or for the restoration of moldings made of stone, characterized in that it consists of an agent according to one of claims 1 to 11 and 13 to 18 in a mixture with the following solid components:

65 - 80% by weight) of granular material with a grain size of 0-2 mm, consisting of quartz sand and / or lime sand,

20-35% by weight of powdery material consisting of quartz powder, limestone powder, powdered Jurassic lime, spade, diatomaceous earth and / or trass and possibly up to 10% by weight of cement.

20. Plasticine for building moldings on a mineral basis for hobbyists and artists, characterized in that it consists of an agent according to one of claims 1 to 11 and 13 to 18 in a mixture with the following solid components: about 2 parts by weight of granular material with a grain size from 0 to 1 mm, consisting of lime sand, quartz sand and margareten sand and about 1 part by weight of floury material consisting of quartz powder, lime powder, flour from Jurassic lime, heavy spar, diatomaceous earth, trass and cement.

21. Plasticine for producing a stone substitute that can be modeled, characterized in that it consists of an agent according to one of claims 1 to 11 and 13 to 18 in admixture with the following solid constituents:

22. modeling clay for the production of a modelable stone substitute, characterized gekenn¬ characterized in that it consists of an agent according to any one of claims 1 to 11 and 13 to 18 in a mixture with the following solid components: about 50 to 70 wt .-% lime sand with a grain size up to 2 mm, 5 to 10% by weight of margareten sand with a grain size of up to 1 mm, 20 to 30% by weight of floury material consisting of lime powder, flour from Jurassic lime, heavy spar, diatomaceous earth, trass and cement.

23. Plasticine according to one of claims 19 to 22, characterized in that it contains marble as part of the granular material.

24. Plasticine according to one of claims 19 to 23, characterized in that it contains 2 to 10% by weight of cement and / or about 2.5% by weight of water glass.

25. Plasticine according to one of claims 19 to 24, characterized in that it contains the agent according to one of claims 1 to 11 and 13 to 18 and the solids mentioned in one of claims 19 to 24 in a weight ratio of approximately 1 part solution to 4 contains up to 6 parts of solids.

26. Plasticine according to one of claims 19 to 25, characterized in that the solids contain 36-66% by weight of lime sand 0-2.

27. Plasticine according to one of claims 19 to 26, characterized in that the solids contain 25-28% by weight of quartz sand 0-2.

28. Plasticine according to one of claims 19 to 27, characterized in that the solids contain 4.5 to 6% by weight of quartz powder.

29. Plasticine according to one of claims 19 to 28, characterized in that the solids contain 7 to 13% by weight of lime powder.

30. Plasticine according to one of claims 19 to 29, characterized in that the solids contain 2 to 4% by weight of Jurassic lime powder.

31. Plasticine according to one of claims 19 to 30, characterized in that the solids contain 2.0 to 2.3% by weight of spar powder, preferably feldspar or heavy spar.

32. Plasticine according to one of claims 19 to 31, characterized in that the solids contain 2.2 to 2.8% by weight of diatomaceous earth.

33. Plasticine according to one of claims 19 to 32, characterized in that the solids contain 1.2 to 1.7% by weight of trass powder.

34. Plasticine according to one of claims 19 to 33, characterized in that the solids contain 5 to 9 wt.% Margaretener Sand 0-1.

35. Plasticine according to one of claims 19 to 34, characterized in that ash or oxidic pigments are included to achieve coloring. _

36. Plasticine according to one of claims 19 to 35, characterized in that for indoor use, the aqueous solution to an extent up to about a quarter by a solution of sodium water glass and / or potassium water glass with a content of 3 - 3.6 wt. % Sodium water glass and 3 - 3.6% by weight potassium water glass is replaced.