RU2531825C1 - Soil reinforcement composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to compositions sued as binder for soil, and can be used in construction and mining. A two-component composition for reinforcing soil by injection contains as an isocyanate component polyphenylene polymethylene polyisocyanate containing 30-31% NCO groups, and as a hydroxyl component a homogenous mixture of alkoxylated alkanetriol with molecular weight of 370-500, ethylene glycol, a urethane-forming catalyst selected from a group comprising dimethylethanolamine and methyldiethanolamine, potassium acetate and a diluent selected from a group comprising chlorinated paraffin wax CP-470 and a mixture thereof with dibutyl phthalate, with content of the isocyanate and hydroxyl components in equal volumes.

EFFECT: invention enables to obtain a composition with low viscosity and no tendency to demixing, having a low reaction temperature and limited foaming.

2 tbl, 16 ex

Description

The invention relates to compositions used as binders for soil strengthening, and can be used in construction and mining.

There are various binders used to strengthen soils based on urea-formaldehyde resins (SU 790718, C08G 12/12, 1994; RU 2270840, C08G 12/12, 2006), acrylic oligomers and polymers (JP 62-22882, C08F 290/00, 1987; RU 2348792, E21B 33/38, C09K 8/508, 2009), polyurethane compositions (JP 2001-152155, C08G 18/10, 2001).

Closest to the proposed one is the known two-component composition for strengthening soils by injection, including the isocyanate and hydroxyl components, which as an isocyanate component contains a prepolymer of methylene diphenyl diisocyanate containing 18-24% NCO-groups, mainly obtained by the interaction of methylene diphenyl diisocyanate with linear dihydric alcohols (glycols) as the hydroxyl component, polyhydric alcohols, mainly containing at least 3 hydroxyl groups in the molecule, it is one of the components comprises a defoamer consisting of a nonionic surfactant and unsaponifiables (RU 2346958, C08G 18/10, C08G 18/28, C08G 18/48, C09J 175/06, 2009). The advantages of the composition are: low reaction temperature (less than 130 ° C), short polymerization time, limited foaming (no more than 5-fold increase in volume).

The disadvantages of the known composition are the high viscosity of the used isocyanate component, even in the presence of thinners (about 800 MPa · s), as well as the tendency of the hydroxyl component to delamination, due to the fact that it includes both high molecular weight (M≈3000) and low molecular weight (M = 280-450) polyether polyols having limited mutual solubility. When using the composition, these circumstances complicate its uniform distribution in the soil, which reduces the efficiency of use.

The problem solved by the invention is to increase the effectiveness of soil stabilization using polymer compositions for this purpose.

The technical result obtained by carrying out the invention is to obtain a composition with a low viscosity and lack of tendency to delamination while maintaining a low reaction temperature and limited foaming.

To achieve this result, a two-component composition for strengthening soils by injection is proposed, including equal amounts of isocyanate and hydroxyl components, characterized in that it contains polyphenylene-polymethylene-polyisocyanate containing 30-31% NCO groups, and a homogeneous mixture as a hydroxyl component alkoxylated alkanetriol with a molecular weight of 370-500, ethylene glycol, a urethane formation catalyst selected from the group consisting of dimethylethanolamine and methyld ethanolamine, potassium acetate and a diluent selected from the group comprising chloroparaffin HP-470 and its mixture with dibutyl phthalate, in the following ratio of ingredients in the composition of the hydroxyl component (parts by weight):

alkoxylated alkanetriol molecular weight 370-500 one hundred Ethylene glycol 1.6-3.6 urethane catalyst 1.9-4.7 potassium acetate 0.8-1.8 Diluent 40-110

It was unexpectedly discovered that a composition for strengthening soils that meets all the necessary requirements for compositions for this purpose and has useful properties that create its advantages over known compositions can be obtained on the basis of readily available raw materials.

The isocyanate component of the proposed composition, produced on a large industrial scale polyphenylene polymethylene polyisocyanate with a content of 30-31% NCO-groups, also known under the common name "polymer MDI", has a much lower viscosity (150-250 MPa · s) than the isocyanate component of the known composition .

The hydroxyl component of the composition consists of five ingredients. The first of these ingredients is an alkoxylated alkanetriol of molecular weight 370-500, which may be, for example, ethoxylated or propoxylated glycerol. The second ingredient is ethylene glycol. The urethane formation catalyst, which is always introduced into the composition of the hydroxyl components used to produce polyurethane foams, is selected from the catalysts commonly used for this purpose - dimethylethanolamine (DMEA) or methyldiethanolamine (MDEA). At the same time, as an additional catalyst providing the specific properties of the component, potassium acetate was introduced into its composition. Finally, the composition contains a diluent inert with respect to the reaction system, for which industrial chlorine paraffin HP-470 with or without dibutyl phthalate is used.

The combination of these ingredients allows you to create a hydroxyl component, which is completely not prone to delamination, is easily distributed in the soil to be strengthened, and reacts quite effectively with the selected isocyanate component, creating a rapidly solidifying polyurethane polymer of sufficient strength. At the same time, the temperature developing during the reaction of the components remains quite low - far, for example, from the ignition temperature of coal (300-325 ° C), which ensures the safety of the composition when strengthening the soil in coal mining.

The invention is illustrated by the following examples. Examples 1-10 illustrate the preparation and properties of a hydroxyl component, examples 11-20 illustrate the preparation and properties of a polyurethane polymer.

Examples 1-8. An alkoxylated alkantriol of molecular weight 370-500, ethylene glycol and a diluent are placed in the flask at room temperature. The ingredients are mixed with a mechanical stirrer until complete homogenization. A urethane formation catalyst and potassium acetate are then added. The solution is stirred for 30 minutes, the density, viscosity and hydroxyl number are determined, and then used as the hydroxyl component of the composition to strengthen the soil. Data on the composition and properties of the obtained hydroxyl component are shown in table 1.

Examples 9-16. Data on the process of interaction of the components of the proposed composition and the properties of the resulting polyurethane polymer are determined in model experiments. Equal volumes of polyphenylene-polymethylene-polyisocyanate (the content of NCO-groups 30-31%) and the hydroxyl component obtained in one of examples 1-8 are placed in a plastic beaker. The components are mixed with a high-speed mechanical stirrer and the setting time is noted (by the formation of a hard crust on the surface of the mass). After complete solidification, the resulting block is sawn and the Shore hardness (scale D) and apparent density are determined, based on which the foaming factor is calculated. The experimental results are shown in table 2.

Table 1 Obtaining a hydroxyl component Example Loading Density, g / cm ³ Hydroxyl number, mg KOH / g Viscosity at 25 ° C, MPa · s Alkoxylated Alcantriol Ethylene glycol, parts by weight Urethane Catalyst Potassium acetate, parts by weight KP-470, parts by weight DBP, parts by weight type of parts by weight type of parts by weight one Laprol 373 one hundred 3.6 DMEA 4.2 1.8 one hundred 0 1.12 260 440 2 Laprol 373 one hundred 3.2 DMEA 3.8 1,6 78.9 0 1.12 285 440 3 Laprol 373 one hundred 2.9 DMEA 3.4 1.4 67.8 31.3 1.10 255 240 four Laprol 373 one hundred 2.9 DMEA 3.4 1.4 78,4 20.7 1,11 255 310 5 Laprol 373 one hundred 2.0 DMEA 4.7 1,0 78.3 20.9 1,11 250 310 6 Laprol 373 one hundred 1,6 DMEA 1.9 0.8 76.3 31,4 1.10 235 310 7 Laprol 373 one hundred 3.6 MDEA 4.2 1.8 78.3 20.9 1,11 245 310 8 Laprol 503B one hundred 2.6 DMEA 3,1 1.3 44,2 0 1,11 340 250 Designations: Laprol 503B - polyoxypropylene triol M = 500 Laprol 373 - polyoxypropylene triol M = 370 DMEA - dimethylethanolamine MDEA - methyldiethanolamine DBP - Dibutyl Phthalate

table 2 Obtaining a polyurethane polymer Example Hydroxyl component according to an example NCO: OH, g-equiv / g-equiv Setting time, s Reaction temperature, ° C The apparent density of the foam, g / cm ³ Foaming factor Shore hardness, scale D 9 one 1.76 31 126 0.48 2,4 70 10 2 1,60 thirty 129 0.52 2.2 72 eleven 3 1.80 32 130 0.61 1.9 76 12 four 1.80 34 130 0.61 1.9 77 13 5 1.82 35 130 0.62 1.9 76 fourteen 6 1.96 fifty 130 0.67 1.7 78 fifteen 7 2.1 40 130 0.60 2.0 76 16 8 2.1 35 129 0.60 2.0 75

Claims (1)

A two-component composition for strengthening soils by injection, including equal amounts of isocyanate and hydroxyl components, characterized in that it contains polyphenylene-polymethylene polyisocyanate with a content of 30-31% NCO-groups, and a homogeneous mixture of alkoxylated alkane-triol with molecular as a hydroxyl component 370-500, ethylene glycol, a urethane formation catalyst selected from the group consisting of dimethylethanolamine and methyldiethanolamine, potassium acetate and a diluent selected from the group comprising chloroparaffin HP-470 and its mixture with dibutyl phthalate, in the following ratio of ingredients in the composition of the hydroxyl component, parts by weight:
alkoxylated alkanetriol molecular weight 370-500 one hundred ethylene glycol 1.6-3.6 urethane catalyst 1.9-4.7 potassium acetate 0.8-1.8 diluent 40-110