RU2563477C2 - Method of producing organophilic bentonite - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to methods of producing organophilic sheet silicates, simultaneously having high heat resistance and structure-forming properties, which can be used as polymer material filler, structuring-forming agents for oil-based drilling mud, in the production of construction materials, in the paint industry etc. The organophilic bentonite is obtained by mixing bentonite with a quaternary ammonium salt, followed by drying. The method includes homogenising the bentonite and a quaternary ammonium salt solution - dialkylbenzylmethylammonium chloride with C₁₄-C₂₂ alkyl radicals in a low-molecular weight alcohol with weight ratio of bentonite to the salt of 10:4.5-10:6.5. The mixture is then stirred at 60-80°C for 30 minutes.

EFFECT: novel organobentonite has a system of useful properties: improved structure-forming properties and heat resistance, high electrical and thermal stability of emulsions based on said organobentonite, which is used as a primary emulsifier in invert-emulsion drilling mud, low consumption of the structure-forming agent in the drilling mud formulation.

5 cl, 3 tbl, 3 ex

Description

The invention relates to methods for producing organophilic layered silicates having both high heat resistance and structure-forming properties that can be used as fillers for polymeric materials, oil-based drilling fluids, in the manufacture of building materials, in the paint and varnish industry, etc.

It is known that organically modified layered silicates are effective structural agents in hydrocarbon media, which allows the use of these compounds in the oil industry. By varying the concentration of organoclay in the hydrocarbon-based drilling fluid formulation, its rheological parameters can be easily controlled. However, we have to admit that today there is a limited number of organically modified clays of domestic production that satisfy the requirements for such compounds, namely: high structure-forming properties and high thermal stability.

A known method of producing organobentonite (RU No. 2393185, IPC C09C 1/42, C09C 3/08, priority date 09/29/2008), comprising reacting bentonite powder with a quaternary ammonium salt (HOUR) at room temperature for 12 hours, drying. The disadvantages of this method are the duration of the process, as well as the inability to use the resulting product as an effective structural agent in emulsion drilling fluids.

The closest analogue is the method for producing organophilic bentonite (RU No. 2176983, IPC C01B 33/40, priority date 12/20/2001), including mixing bentonite powder with a quaternary ammonium salt (HOUR). Salts of the type dialkyl dimethylammonium chloride with long alkyl hydrocarbon radicals C ₁₆ -C ₁₈ are used as HOUR. HOUR additionally contains isopropyl alcohol and water. The disadvantages of the method are: the need to use low pressure (0 <P _cm <1 ATM), as well as insufficient structure-forming properties of the resulting organobentonite.

The objective of the proposed technical solution is to create an effective organobentonite with a characteristic set of properties:

- high structure-forming properties;

- high heat resistance;

- high electrical and thermal stability of emulsions obtained using this organobentonite;

- the possibility of use as a primary emulsifier in drilling fluids based on inverse emulsions.

The technical result is achieved by the fact that the method of producing organophilic bentonite is carried out by mixing bentonite with a quaternary ammonium salt, followed by drying, while homogenizing bentonite and a solution of the quaternary ammonium salt - dialkylbenzylmethylammonium chloride with C ₁₄ -C ₂₂ alkyl hydrocarbon radicals in low molecular weight alcohol bentonite and salt 10: 4.5-10: 6.5 and subsequent stirring of the mixture at a temperature of 60-80 ° C for 30 minutes.

The technical result of the claimed technical solution is the creation of a new organobentonite with a set of useful properties: high structure-forming properties and heat resistance, high electrical and thermal stability of emulsions based on this organobentonite, used as a primary emulsifier in drilling fluids based on inverse emulsions, reducing the consumption of structure former in the formulation drilling fluid, and therefore increasing the economic benefits of using this fluid.

The presence in the HOUR molecule of two alkyl and one benzyl radicals makes it possible to increase the steric factor and also increase the hydrophilicity of the resulting organobentonite; moreover, the introduction of an aromatic radical into the molecule of the quaternary ammonium salt affects the thermal stability of the resulting organobentonite. This phenomenon can be explained by the shielding effect of the aromatic residue, which can accumulate energy coming from outside. Modification of bentonite in a homogeneous or pasty form can increase the uniformity of the distribution of the excess molecules of the organic modifier on the surface of bentonite. In addition, the use of these surfactants as surface modifiers for clay allows the use of layered silicates with a cation exchange capacity of less than 100 mg * equiv / 100 g as raw materials.

The implementation of the invention

Organomodification of bentonite according to the claimed invention is carried out by homogenizing at room temperature a bentonite powder or bentonite paste and a 70-85% solution of a quaternary ammonium salt - dialkylbenzylmethylammonium chloride with alkyl hydrocarbon radicals C ₁₄ -C ₂₂ in low molecular weight alcohol (methanol, ethanol, propanol , butanol, etc.) with a mass ratio of bentonite and salt of 10: 4.5-10: 6.5, stirring for 30 minutes at a temperature of 60-80 ° C, drying organobentonite and grinding it.

The quaternary ammonium salt is added to the bentonite paste, which is an aqueous suspension of montmorillonite (bentonite powder - 20%; water - 80%), for 5-10 minutes, in order to evenly distribute the organ modifier molecules on the clay surface. It is necessary that the quaternary ammonium salt used additionally contains low molecular weight alcohol, which allows accelerating the process of interaction of the quaternary ammonium salt with bentonite paste.

The inventive method for producing organophilic bentonite by mixing quaternary ammonium salts with bentonite clay powder or paste is completely waste-free and allows you to get an effective structure-forming agent for hydrocarbon-based drilling fluids.

The inventive method for producing organophilic bentonite was tested in laboratory conditions.

The resulting organobentonite was tested as a builder in a hydrocarbon-based emulsion drilling fluid.

Below are examples of the implementation of the proposed technical solution.

Example 1

50 g of bentonite paste with a humidity of 80% was homogenized with 7.5 g of a quaternary ammonium salt - benzylmethyl dihydrogenated tall ammonium chloride. The reaction mass was stirred for 30 minutes at T = 60 ° C, after which it was removed from the reactor and placed in an oven (T = 80-90 ° C) for drying to a moisture content of not more than 2%. Humidity was determined according to GOST 14870-77. After drying, organobentonite was ground. The product is a cream to gray powder.

Example 2

10 g of dry clay was homogenized with 13 g of a 50% quaternary ammonium salt of benzylmethyl dihydrogenated tall ammonium chloride. The reaction mass was stirred for 30 minutes at 60 ° C, after which it was placed in a furnace T = 80-90 ° C for drying to a moisture content of not more than 2%. Humidity was determined according to GOST 14870-77. After drying, organobentonite was ground. The product is a cream to gray powder.

Example 3

Using a multimixer (mixing speed 11000 rpm), emulsion drilling fluids were prepared using organobentonites obtained (examples 1-2) as a structurant. The composition, order of input of the components of the drilling fluid and the mixing time of the components are shown in table 1.

The rheological parameters of the prepared solutions (table 2) were measured using an OFITE 900 rotational viscometer at room temperature according to API 13 B-2 method after 1 hour and 16 hours after solution preparation. As reference samples, commercially available organobentonites VG + ”(MISwaco) and Organobentonite“ 881-A ”(QingHong) were used, which were also used in the preparation of drilling mud formulation 1. Table 3 presents comparative data of a 7 and 10% suspension of organobentonite according to example 1 of this patent with similar parameters of the closest analogue (RU No. 2176983 C1, C01B 33/40, 12/20/2001), and also a comparison of the sedimentation stability of these organobentonites. Sedimentation stability was measured according to TU 39-0148052-001-90 (in toluene).

As can be seen from the data of tables 2 and 3, the proposed method for producing organobentonite allows to achieve better results compared to existing commercially available organobentonites, as well as the closest analogue.

Quaternary ammonium salts are used in the claimed technical solution for a new purpose - as organic surface modifiers of the layered silicate.

From the studied prior art it is known that ammonium salts that do not contain two “long” lipophilic and one benzyl in their structure do not allow organically modified clays with high structure-forming properties and high thermal stability, while quaternary ammonium salts of the formula with two alkyl and one benzyl radicals allow to solve this problem.

Studied by the applicant prior art at the filing date of the application materials did not reveal the presence in the prior art similar to the claimed technical solution.

The claimed technical solution meets the criterion of "novelty" presented to the invention, since the investigated prior art has not identified technical solutions characterized by the indicated features, leading to the implementation of the claimed technical results of the claimed technical solution.

The claimed technical solution meets the criterion of "inventive step", as it is not obvious to specialists in this field of technology.

The claimed technical solution meets the criterion of "industrial applicability", as it can be implemented at any specialized enterprise using standard equipment, well-known materials and technologies.

Claims (5)

1. A method of producing organophilic bentonite by mixing bentonite with a quaternary ammonium salt, followed by drying, characterized in that the bentonite and a solution of a quaternary ammonium salt - dialkylbenzylmethylammonium chloride with alkyl hydrocarbon radicals C ₄ -C ₂₂ are homogenized in a low molecular weight alcohol with bentonite mass 10: 4.5-10: 6.5 and subsequent stirring of the mixture at a temperature of 60-80 ° C for 30 minutes. 2. The method according to p. 1, characterized in that the bentonite is used in powder form. 3. The method according to p. 1, characterized in that the bentonite is used in the form of a bentonite paste. 4. The method according to p. 1, characterized in that the addition of a solution of the Quaternary ammonium salt of dialkylbenzylmethylammonium chloride with C ₁₄ -C ₂₂ alkyl hydrocarbon radicals in low molecular weight alcohol to bentonite for homogenization is carried out for 5-10 minutes. 5. The method according to p. 1, characterized in that after drying, grinding of organophilic bentonite is carried out.