DE10153980A1 - Biodegradable polyurethane composition for stabilizing soil, e.g. in tunnel building, contains natural organic material with isocyanate-reactive groups, e.g. lignin, and polyisocyanate component - Google Patents

Abstract

A polyurethane-type composition (I) for stabilizing soil, in which one component (A) is a naturally-occurring organic material containing groups which are reactive towards isocyanate groups and the other (B) is a conventional polyisocyanate. Independent claims are also included for (a) a method for the production of (I) by mixing components (A) and (B); (b) a method for stabilizing soil by injecting (I) into the soil.

Description

BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION

The present invention relates to a composition for solidifying Soil and a method for soil consolidation, in particular a composition for Consolidation and stabilization of soils, especially flexible ground, such as Topsoil, loose rock, etc., as well as a method for consolidating the soil.

2. DESCRIPTION OF THE PRIOR ART

So far, the construction of a tunnel, especially in soft underground, has been so executed that in the front part of the tunnel ceiling at the upper end portion of the working joint an opening was broken in the tunnel and one by mixing two liquids obtained curable composition of urethane was pressed into the opening so that the Composition penetrates the floor and hardens it and thus the ceiling of the Work impact in the tunnel could no longer fall. After hardening and solidification desi reason at the front end portion of the work joint then the solid soil on excavated the front end section of the tunnel front.

However, the disposal of the excavated soil causes a strain on the Environment because it contains polyurethane foam that is not degradable in a natural environment. Therefore, the excavated soil must be disposed of without breaking down urethane foam unacceptable. Such protection of the environment when the excavated soil is disposed of However, it has the disadvantage that special processes are used to break down the polyurethane foam are required, which results in higher costs with shorter dismantling times. The result was the pronounced desire for a composition for soil stabilization, which in the Soil that is to be excavated is easily biodegradable.  

SUMMARY OF THE INVENTION

As a result of intensive research to develop a biologically extremely easy degradable soil stabilization composition has been found to be possible with the combination of a composition of polyisocyanate and a natural occurring organic material with one for reaction with the isocyanate group suitable reactive group that is derived from the naturally occurring organic material structure originating in the basic structure of the reaction of the reactive group of naturally occurring organic material with the isocyanate group of the polyisocyanate Incorporation of the polyurethane compound obtained that the obtained therefrom Polyurethane compound in the natural environment of microorganisms living in the soil can be broken down and that, moreover, with remarkably high efficiency biodegradable.

The present invention is therefore based on the object To provide soil consolidation composition, which in the excavated soil is easily biodegradable.

To achieve the object, the invention provides a widely degradable Soil stabilization composition, which is a naturally occurring organic material (component A) with one for reaction with an isocyanate group qualified reactive group and a polyisocyanate compound (component B).

A further object of the invention is a method for the preparation of a soil stabilization composition for use in a To provide solidification of the soil and a method for solidification of the soil with the widely degradable composition for soil consolidation.

To achieve these additional objects, the invention provides, as described above, a method of making a soil consolidation composition, which mixing a solution containing component A, component A being itself from a naturally occurring organic material with one to react with one  Isocyanate group capable reactive group with a component B containing solution, wherein component B consists of a polyisocyanate compound composed, includes.

In addition, the present invention provides a method for solidifying the Soil available in which the composition for soil consolidation a solution containing component A, wherein component A consists of a naturally occurring organic material with one to react with one Isocyanate group capable reactive group, and a component B containing solution, wherein component B consists of a polyisocyanate compound composed, includes.

DETAILED DESCRIPTION OF THE PREFERRED INVENTION EMBODIMENTS

The soil consolidation composition according to the invention comprises a naturally occurring organic compound with a for reaction with an isocyanate Group enabled reactive group (component A) and a polyisocyanate compound (Component B).

As a naturally occurring organic material (component A), any Compound with a reactive with the isocyanate group of the polyurethane compound reactive group (e.g. a hydroxyl or a carboxyl group). exemplary for this are both lignin, molasses, saccharides, such as. B. mono-, di- and oligosaccharides and polysaccharides such as e.g. B. starch, cellulose and hemicellulose as well as their Denaturation. These materials can be used individually or in combination of two or more can be used. Of these materials, lignin, Molasses, starch or denatured starch products are used.

Any product can be used as lignin, provided that it is the main component of a product woody representative is used, such as. B. wood, straw, etc. Such lignin can e.g. B. Kraft lignin, solvolysed lignin, ligninsulfonic acid, ligninsulfonates, etc. The Molasses are not limited to any particular one, provided they are only from sugar cane,  Sugar beets, etc. are made and they can e.g. B. from unrefined molasses, refined molasses, refined molasses slits, accrued after refining Molasses residues, etc. Any polysaccharide in which can be used as starch Glucose is polymerized and which in large quantities in the roots of cereals, plants etc. are included. Linear amylose and branched amylopectin are examples of starches etc. called. As a special kind of naturally occurring organic material (Component A) can also denatured products of lignin, molasses, starches, etc. be used.

It is preferred according to the invention that the naturally occurring organic material in liquid state. To dissolve the naturally occurring natural Any means which is the naturally occurring material is suitable for a solution Can convert material to the liquid state. As such an agent is preferred an organic compound capable of reacting with the polyisocyanate compound used. As such an organic compound, an organic one is preferably used Compound with at least two active hydrogen atoms used in the basic structure, especially a polyol. As polyfunctional and active hydrogen-containing organic Examples of compounds are ethylene glycol, polyethylene glycol, propylene glycol, Polypropylene glycol, trimethylolethane, trimethylolpropane, hexylene glycol, an alkylene glycol castor oil, glycerin, sorbitol, sucrose, ethylenediamine, diethanolamine, triethanolamine etc. called. The polyfunctional and active hydrogenated organic Connections can be used individually or in combination of two or more become. It is also possible to use a polyether-polyol compound that is manufactured can be by using an alkylene oxide, such as. B. ethylene oxide or propylene oxide, one Ring opening and polymerization are subjected. This connection can also be made individually or used in combination of two or more.

Should the naturally occurring organic material in a solution with the polyfunctional and active hydrogen containing compound (the organic Reagent), such as polyol or the like., The material with the organic Reagent in the ratio of preferably 10:90 to 90:10 (material: organic Reagent), particularly preferably 20:80 to 80:20, especially if biodegradability should be considered.  

For setting the start-up time for the foaming of the polyisocyanate compound component A is preferably prepared using an amine catalyst. As such Examples of amine catalysts are triethylenediamine, bis (dimethylaminoethyl) ether, Tetramethylhexamethylene diamine, tetramethyl propane-1,3-diamine, Pentamethyldiethylenetriamine, bis (dimethylmethylaminoethyl) ether, Trimethylaminoethylpiperazine, 1-methylimidazole, 1-isobutyl-2-methylimidazole, etc. specified. Examples include a metal, such as. B. containing lead, tin or the like Urethane catalyst listed, such a urethane catalyst such. B. Can be dibutyltin dilaurate, etc. These amine catalysts can also be used individually or in A combination of two or more can be used.

So that an effect is achieved by the addition of the amine catalyst, the Amine catalyst preferably with the naturally occurring organic material and of the polyfunctional and active hydrogen containing compound in an amount of 0.1 to 5 parts by weight, particularly preferably with 0.1 to 2 parts by weight based on 100 parts by weight Parts of the naturally occurring organic material and the polyfunctional active Compound containing hydrogen can be prepared.

Component A can also contain a foam stabilizer, fire-retardant material, contain a viscosity reducing agent, etc. The foam stabilizer can for example a polyoxyalkylene-dimethylpolysiloxane copolymer, an organopolysiloxane, an oxyethylated higher alcohol, etc. These foam stabilizers can be used individually or can be used in combination with two or more. The fire retardant material can e.g. B. Tris-chloropropyl phosphate, Tris-β-chloropropyl phosphate, etc. and that Fire retardant material can also be used alone or in combination of two or more be used. Furthermore, the viscosity reducing agent z. B. Propylene carbonate (PC), a methyl ester of an aliphatic acid, etc. and that Viscosity reducing agents can be used singly or in combination of two or more be used.

The viscosity of one of the special types of natural discussed above occurring organic material (component A) containing solution should  Range of preferably 5 to 500 cps / 20 ° C can be set, particularly preferably to the range from 35 to 200 cps / 20 ° C. If the viscosity of the solution was below 5 cps / 20 ° C, the content of the viscosity reducing agent, e.g. H. the content of low molecular weight components become too large, so that the solidified material obtained would become brittle. On the other hand, if the solution viscosity increases above 500 cps / 20 ° C If it were to lie, the extent of penetration into the soil could increase would be small.

There is no particular one for the type of polyisocyanate compound (component B) Restriction and any conventional connection, such as. B. a Polyisocyanate from an aromatic group, a polyisocyanate from an aliphatic Use group and the like. Specific examples of such a polyisocyanate are Diphenylmethane 4,4'-diisocyanate (MDI), polymeric MDI (crude MDI: C-MDI), Toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), Xylene diisocyanate (XDI) and its denatured derivatives. These polyisocyanates can be used individually or used in combination of two or more. Of these polyisocyanate Compounds MDI, C-MDI and their denatured derivatives are preferably used, especially when particular emphasis is placed on working conditions and the economy.

Component B can also be a viscosity reducing agent along with the Contain polyisocyanate compound. The polyisocyanate compound is said to be in an amount of preferably 50% by weight, particularly preferably 80% by weight, can be added, based on the total amount of component B. The viscosity for the polyisocyanate Compound Component B (in the dissolved state) is said to be in the range of preferably 5 to 500 cps / 20 ° C., particularly preferably 25 to 200 cps / 20 ° C. be of particular importance to the mixing process and penetration into the earth is laid. If the viscosity were to be below 5 cps / 20 ° C, on the one hand, the degree of solidification of the solidified material becomes too low. If, on the other hand, the If the viscosity were to be above 500 cps / 20 ° C, the degree of penetration into the soil would be small become.

In the following, the method for consolidating the soil with the Composition according to the invention for soil consolidation described.  

To the composition according to the invention for soil consolidation for the Using solidification of the soil becomes a solution containing component A. A and a solution B containing component B are prepared separately.

The solution A containing component A comprises component A and a organic reagent for dissolving component A, such as. B. a glycol or the like. In addition to component A and the organic reagent, solution A can be a contain auxiliary components usually used for a specific purpose, for example a foaming agent (e.g. water), a urethane-forming catalyst (e.g. an amine catalyst), a foam stabilizer, a viscosity reducing agent or The like. All of these auxiliary components can be those that are usually used in the Urethane foam production are used and which according to the invention Auxiliary components to be used can suitably be made from these in the prior art known auxiliary components are selected.

Although the solution B containing component B typically consists only of itself of component B in the liquid state, it can be a suitable one if necessary Contain an amount of an adjuvant commonly used in the art. As Auxiliary components come, for example, a viscosity-reducing agent, a non-reactive organic solvent or the like.

Then solution A is typically mixed with solution B and the mixed solution obtained injected into the soil as a substrate to be solidified or this admixed. This allows components A and B in the mixed solution with each other react to a polyurethane with one made from the biodegradable and natural occurring organic material to form biodegradable structure.

The weight ratio of solution B to solution A should be in the range of typically 0.5: 6, preferably 1: 3, based on the weight fraction of solution A.  

After preparation of the mixed solution containing components A and B existing composition can be on site or in the process described above the components A and B and the auxiliary components in the polyol or the like. existing organic reagent are mixed together.

The composition according to the invention should preferably be prepared in such a way that the volume increase when foaming typically in the range of 1.5 to 6 times is preferably 2 to 6 times if it is made using the sand column method (standard Test method; Geofront Kenkyukai) was determined. On the one hand, cheat the Volume increase when foaming less than 1.5 times would be the impact on the consolidation of the soil less and a larger amount of the composition to be pressed, which would lead to higher costs. On the other hand the volume increase when foaming over 6 times, it can be shown that the The extent of the consolidation of the soil tends to be smaller.

The composition of the invention should also be prepared so that a Sample containing sand has a monoaxial compressive strength in the range of preferably 0.5 to 20 MPa, particularly preferably 1 to 10 MPa, after having as above described, has been tested according to the sand pillar method. Would be the one monoaxial compressive strength of the specimen less than 0.5 MPa, the strength of the Solidification of the soil is less. On the other hand would be the monoaxial Compressive strength of the specimen greater than 20 MPa would be the strength of the solidification of the Soil too high, so that it takes a long time to excavate the solidified soil and would have to spend higher costs.

The soil consolidation composition of the present invention may preferably be used for reforming flexible soil (topsoil, boulders, etc.) to solid Be used underground. In addition, the composition can also be used as Fastening means for fastening bolts to rocks, for fastening bolts to normal surfaces, etc. are used.

The present invention is explained in more detail with reference to the drawings. in the The starting materials used in the examples are described below.  

KL-P33: A solution of Kraft lignin with one equivalent of hydroxyl groups of 7.0 meq / g dissolved in polyethylene glycol (PEG-200; molecular weight: 200) (Concentration of Kraft lignin: 33% by weight).

MP-33: A solution of molasses with one equivalent of hydroxyl groups from 11.5 meq / g dissolved in polyethylene glycol (PEG-200; molecular weight: 200) (concentration molasses: 33% by weight).

SL-33: A solution of solvolysed lignin with one equivalent Hydroxyl groups of 7.0 meq / g dissolved in polyethylene glycol (PEG-200; molecular weight: 200) (concentration of solvolysed lignin: 33% by weight).

LSMe: A 50% aqueous solution of lignosulfonic acid (Ca or Na salt) dissolved in Water.

Amine Catalyst 1: A solution of triethylene diamine in dipropylene glycol (Product name: KAOLYSER No. 31).

Amine catalyst 2: a solution of N, N, N ', N' ', N' '' - pentamethyldiethylenetriamine (Product name: KAOLYSER No. 3).

Foam stabilizer: silicone surfactant (Nippon Uniker K.K., Product name: L-5421).

Fire retardant: Tris-β-chloropropyl phosphate (Daihachi Kagaku Kogyo K.K., Product name: TMCPP).

Viscosity reducing agent: polycarbonate (PC).

Polyisocyanate: C-MDI (BASF INOAC, product name: Luplanat MB-5S).  

Examples 1-5 and Comparative Example 1

A solution A was obtained from the components with those in Table 1 below reproduced amounts and one composed of the above polyisocyanate Solution B prepared. It should be pointed out here that in Example 5, that from 50 Parts by weight of MP-33 composite solution A after pressing in 50 Parts by weight of LsMe was pressed. In each example, solutions A and B - as shown in Table 1 below - based on their properties according to standardized Evaluation procedure assessed.

Start time (CT): period for the foaming of the mixed solutions A and B after End of the mixing process immediately before the expansion of the mixed solution begins a milk-colored creamy liquid.

Swelling time (RT): The measurement takes place over the period that is required until the creamy liquid has turned into a foam and the expansion has ended.

Volume increase when foaming: 50 g each of solution A and solution B were poured into a 1 liter jar and and with a stirrer at 1000 rpm for 10 seconds long stirred while the temperature for the reaction of solution A with solution B in the Mixed solution was kept at 20 ° C. To determine the volume increase after the reaction the height of the foam was measured.

Exothermic maximum temperature: A temperature sensor was placed in the 1 liter container installed and the released maximum temperature measured and with a Recorder recorded.

Fire resistance: The fire resistance was determined according to the standard test procedure determined according to JIS K 7201. The measurement was carried out in such a way that solution A and solution B in one predetermined mixing ratio was mixed and the mixed solution up to 4 times Volume enlargement was foamed. Then the fire resistance was called Determined oxygen index of the foam obtained.  

Table 1

Biodegradability: One with the predetermined mixing ratio of Solution A becomes solution B with a foam from a soil sample extracted liquid mixed and the mixture stirred. Then the extent of Weight loss of the foamed material measured to the degree of biological Determine degradability. Biodegradability was rated as good (0) if the weight of the foamed material has increased by more than 10% by weight over 6 months or lost more. On the other hand, the biological Degradability rated as not good (X) when the weight of the foamed material had decreased by less than 10% by weight over 6 months.

As can be seen from Table 1 above, in all of Examples 1 to 5 examined samples found that they showed better biodegradability than that Sample examined in Comparative Example 1. Furthermore, all of the samples in Examples 1 to 5 showed generally just as good properties of the urethane as in Comparative Example 1.

It was further found that each of the samples used in Examples 1 to 5 had a slightly higher viscosity than the sample used in Comparative Example 1 and that However, they have approximately the same viscosity as that of solution B (Luplanat MB-65) alone. It has therefore been found that the composition according to the invention posed practically no problems with regard to viscosity.

Then the investigations for the pressing and the monoaxial Compressive strength for each of those used in Examples 1 to 5 and Comparative Example 1 Samples according to the sand pillar method (Geofront Kenkyukai: Urethane Injection Offer Bowling technology paints; Standard test procedure). The results are below reproduced in Table 2.

Penetration studies

270 g of a commercially available quartz sand (No. 4) were poured into a tube Filled with acrylic resin, the surface of which had previously been lubricated, and water infused. After the tube was shaken, excess water became removed and the sand heaped to a height of 14 to 15 cm. Then one became  predetermined amount of (in Examples 1 to 5 and in Comparative Example 1) Composition entered in the heaped sand and the mixture to Mixing the composition with the sand stirred. Then the depth of penetration, the measure of solidification and volume increase when foaming in the sand measured.

Test for monoaxial compressive strength

A test piece taken from the ground became a columnar sample shaped (diameter: 40 mm; height: 80 mm) and the density measured. Then the Sample according to a test for monoaxial compressive strength according to the standard test method Subjected to JIS K 1216. The test results are shown in Table 2 below played.

Table 2

As can be seen from the test results shown in Table 2 above, show all of the compositions prepared according to Examples 1 to 5 essentially that same penetration behavior and the same compressive strength as that according to Comparative Example 1 manufactured composition. From this it can be concluded that all of the compositions  of Examples 1 to 5 produced products as soil stabilizers for consolidation of soil are suitable.

MEANING OF THE INVENTION

As described above, the composition of the invention settles Solidification of soil from a polyisocyanate compound and a natural one occurring organic material with an isocyanate group of polyisocyanate Compound reacting reactive group together. Therefore the reactive group reacts of the naturally occurring organic material with the isocyanate group Polyisocyanate compound to form the backbone of the obtained polyurethane, in which is the structure derived from the naturally occurring organic material can be installed. The polyurethane obtained can be found in the soil Degrade microorganisms and shows a high degree of biodegradability.

By adjusting the viscosity of solutions A and B to a specific one Range, the penetration behavior of the composition according to the invention greatly improve and bring the composition into any type of floor.

The mixture of solution A with solution B to form foamed Polyurethane with a predefined range for the oxygen index up to 4 times Foamed volume increase, the polyurethane foam obtained can also be a have a particularly high degree of fire resistance.

In addition, the composition according to the invention has soil stabilization good penetration behavior suitable for a soil stabilizer, in particular if the composition is up to a predetermined one according to the sand pillar method Volume enlargement is foamed.

Furthermore, the composition according to the invention has for the consolidation of soil a compressive strength to be required for a soil stabilizer, especially if the sand-containing composition after tests according to the sand pillar Method has a monoaxial compressive strength in the predetermined range.

Claims (13)

1. Composition for the consolidation of soil, which is a component A, the itself from a naturally occurring organic material with one to react with an isocyanate group capable reactive group, and one from one Component B composed of polyisocyanate compound. 2. A composition for the consolidation of soil according to claim 1, in which the naturally occurring organic material of component A at least one compound which is selected from the group consisting of lignin, molasses, starch and denatured products the same. 3. Soil consolidation composition according to claim 1 or 2, in which a mixture of component A with component B a liquid with a Viscosity at 20 ° C is in the range of 5 cps to 500 cps. 4. A soil consolidation composition according to claim 3, in which the Viscosity of a mixture of component A with component B a viscosity at 20 ° C. in the range of 35 to 200 cps. 5. Composition for the consolidation of soil according to one of claims 1 to 4, in which by foaming the mixture of component A with the Component B compound liquid obtained with a 4-fold increase in volume Foam fire retardancy, expressed as an oxygen index, in the range of 22 or greater having. 6. Composition for the consolidation of soil according to one of claims 1 to 5, in which by foaming the mixture of component A with the Component B composite liquid obtained foam up to 1.5 to 6 times Volume increase, measured according to the sand column method, is foamed.   7. Composition for solidifying soil according to claim 6 with a 2.0 to 6.0 times volume increase when foaming. 8. A soil consolidation composition according to claim 7, in which a foamed material and material containing sand when determined according to Sand column process a monoaxial compressive strength in the range of 0.5 to 20 MPa having. 9. Soil consolidation composition according to claim 8, in which a foamed material and material containing sand when determined according to Sand column process a monoaxial compressive strength in the range of 1.0 to 10 MPa having. 10. Process for the preparation of a composition for the consolidation of soil, which is the mixing of a component A resulting from a naturally occurring organic material with a reactive capable of reacting with an isocyanate group Group composed with one composed of a polyisocyanate compound Component B comprises. 11. The method of claim 10, in which the naturally occurring organic Material of component A comprises at least one compound which is selected from the Group of lignin, molasses, starch and denatured products thereof. 12. Process for solidifying soil, which involves the entry of a A composition according to any one of claims 1 to 9 in the soil. 13. A method of solidifying soil according to claim 12, in which the Composition for consolidating soil comprises a solution which is a Component A contains, which consists of a naturally occurring organic material is composed of a reactive group capable of reacting with an isocyanate group, and a solution comprising a polyisocyanate compound Component B contains.