RU2683320C1 - Double polycylacate of alkali metal and organic base - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to chemistry of silicates. Disclosed is a double polysilicate of an alkali metal and an organic base of formula (I) (4-12)SiO₂∙M₂O∙(0.5-0.05)(N_1-2R₄ ^1,2,3,4)₂O∙(10-60)H₂O, where M is an alkali metal cation, N_1-2R₄ ^1,2,3,4 – organic base – polymer based on oxyalkylated amine or diamine. Disclosed double polysilicate is in form of particles with specific surface area of 340–740 m²/g; surface of particles contains polycation of organic base in amount of 0.1–0.2 nitrogen functional groups per 10 nm². Obtained double polysilicates have characteristic absorption bands of infrared spectrum in regions of 1,026–1,121 cm^-1 and 1,634–1,651 cm^-1.

EFFECT: disclosed double polysilicate can be obtained from available crude components and can be used as binder for producing thin coatings on metal, plastic and other materials, components of heat-resistant paints, adhesives used in various fields of engineering.

1 cl, 3 dwg, 2 tbl, 5 ex

Description

The invention relates to the chemistry of silicates, in particular to a double alkali metal polysilicate and an organic base, which can be used as a binder to obtain thin coatings on metal, plastic and other materials, to obtain adhesives, components of heat-resistant paints used in various fields of technology.

The level of technology.

The need to improve some properties of composite materials, such as water resistance and thermal properties, led to the development of "high-modulus liquid glasses" - alkali metal polysilicates. Polysilicates include alkali metal silicates (silicate module from 4 to 25), which are a transition region of compositions from liquid glasses to silicas stabilized with alkali. Polysilicates are characterized by a wide range of degree of polymerization of anions and are dispersions of colloidal silica in an aqueous solution of alkali metal silicates [1].

A relatively new area of the science of water-soluble silicates, which has now found a significant practical solution, is the silicates of organic bases. The synthesis of this class of compounds is based on the ability of silica to dissolve in the region of pH above 11.5 in organic bases of various nature, primarily in Quaternary ammonium bases. Quaternary ammonium bases are strong enough bases for dissolving silica in them. Water-soluble silicates of this class — quaternary ammonium silicates — are characterized by the general formula [N (R ¹ , R ² , R ³ , R ⁴ )] ₂ O⋅nSiO ₂ , where R ¹ , R ² , R ³ , R ⁴ is H, alkyl -, aryl - or alkanol groups [2, 3, 4].

Quaternary ammonium silicate solutions are usually highly silica lyophilic stable disperse systems in which silica is present both in colloidal forms and in forms characteristic of true solutions. They are often produced in cases where the sodium or potassium analogues of such systems turn out to be insufficiently stable [5]. The dissolved silica in such systems is oligomers with a degree of polymerization of 10–25, the particle size of colloidal silica increases from 2 to 100 nm depending on the value of the silicate module of the system within n = 2–12. Lower alkyl and alkanol derivatives - tetrabutylammonium silicate, tetraethylammonium silicate, tetraethanolammonium silicate found the greatest practical application.

где М - представляет собой по меньшей мере один щелочной металл; X - составляет от около 0,5 до 1,5; n - указывает количество атомов азота и представляет собой небольшое целое число менее 10; R - представляет собой органический радикал, который образует основание NR, выбранное из группы, состоящей из алкиламинов, алканоламинов, гетероциклических аминов и циклических аминов, которые продуцируют растворы с рН не менее 9; р - равно числу R-групп и составляет не менее 4 и до 4 n; s - целое число от 1 до р, указывающее количество различных типов R групп; Y - от 2 до 10; Z - составляет от 1 до 40.US 3,239,549 (Alkali metal and quaternary ammonium double salts of silicic acid. Weldes Helmut Hans Wilhelm, PQ Corp., 1960-08-22) describes a compound having the formula:

where M - represents at least one alkali metal; X is from about 0.5 to 1.5; n - indicates the number of nitrogen atoms and is a small integer less than 10; R - is an organic radical that forms an NR base selected from the group consisting of alkyl amines, alkanolamines, heterocyclic amines and cyclic amines, which produce solutions with a pH of at least 9; p is equal to the number of R-groups and is at least 4 and up to 4 n; s is an integer from 1 to p indicating the number of different types of R groups; Y - from 2 to 10; Z - is from 1 to 40.

где М - представляет собой по меньшей мере один щелочной металл; X - составляет от около 0.5 до 1,5; n - указывает количество атомов азота и представляет собой небольшое целое число менее 10; R - представляет собой органический радикал, который образует основание NR, выбранное из группы, состоящей из алкиламинов, алканоламинов, гетероциклических аминов и циклических аминов, которые продуцируют растворы с рН не менее 9; р - равно числу R-групп и составляет не менее 4 и до 4n; s - целое число от 1 до р, указывающее количество различных типов групп R; Y - находится между 2 и 10; Z - составляет от 1 до 40; который включает взаимодействие гидроксида четвертичного аммония, имеющего рН по меньшей мере 9, с силикатом щелочного металла, кристаллизацией и извлечением кристаллизованного продукта. В качестве гидроксида четвертичного аммония могут использоваться соединения: гидроксид тетраэтаноламмония, гидроксид тетраметиламмония, 2-тетрагидроксиэтилпиперазинийгидроксид, гидроксид N,N'-бис-бета-гидроксиэтилморфолиния.US Pat. No. 3,383,386 (Process for making alkali metal quaternary ammonium silicates Weldes Helmut Hans Wilhelm, PQ Corp, priority 1960-08-22) describes a process for preparing compounds having the formula:

where M - represents at least one alkali metal; X - is from about 0.5 to 1.5; n - indicates the number of nitrogen atoms and is a small integer less than 10; R - is an organic radical that forms an NR base selected from the group consisting of alkyl amines, alkanolamines, heterocyclic amines and cyclic amines, which produce solutions with a pH of at least 9; p is equal to the number of R-groups and is at least 4 and up to 4n; s is an integer from 1 to p indicating the number of different types of R groups; Y - is between 2 and 10; Z - is from 1 to 40; which comprises reacting a quaternary ammonium hydroxide having a pH of at least 9 with an alkali metal silicate, crystallizing and recovering a crystallized product. The following compounds can be used as quaternary ammonium hydroxide: tetraethanolammonium hydroxide, tetramethylammonium hydroxide, 2-tetrahydroxyethylpiperazinium hydroxide, N, N'-bis-beta-hydroxyethylmorpholine hydroxide.

US 3,630,954 (Organic amine-strong base stabilized high surface area silica sols and method for preparing the same, EI du Pont de Nemours and Co) proposes colloidal silica stabilized with an organic base such as morpholine, cyclohexylamine having a surface area of 950 m or more ² / g to 1800 m ² / g, with a mass fraction of SiO ₂ from 10% to 30%, with a ratio of SiO ₂ : Na ₂ O in the range from 7: 1 to 20: 1, due to the presence of an organic base from 0.05 up to 2.0 moles per kilogram of composition.

Closest to the proposed invention in technical essence are double silicates, which are described in patent US 3769309 (Process for alkali metal and quaternary nitrogen compound double salts of silicic acid. 1968-11-15) containing sodium silicate, potassium, lithium and quaternary ammonium silicate which have the formula: M ₂ O⋅X (N _n R _p ^S ) ₂ O⋅YSiO ₂ ZH ₂ O, where M - represents at least one alkali metal; X is from about 0.5 to 1.5; n - indicates the number of nitrogen atoms and is a small integer less than 10; R - is an organic radical that forms the base NR selected from the group consisting of alkylamines, alkanolamines, which produce solutions with a pH of at least 9; p is equal to the number of R-groups and is at least 4 and up to 4n; s is an integer from 1 to p indicating the number of different types of R groups; Y - from 2 to 10; Z - is from 1 to 40.

The objective of the present invention is to expand the range of double silicates with the aim of using them as a binder to obtain thin coatings on metal, plastic and other materials, to obtain adhesives, components of heat-resistant paints used in various fields of technology.

The technical problem is solved by a new chemical compound, which is a double alkali metal polysilicate and an organic base of the formula

- органическое основание - полимер на основе оксиалкилированного амина или диамина, R¹, R², R³, R⁴ - Н, алкил -, арил - или алканолгруппы. Двойной полисиликат находится в форме частиц с удельной поверхностью 340-740 м²/г, поверхность частиц содержит поликатион органического основания в количестве 0,1-0,2 функциональных групп азота на 10 нм². Двойные полисиликаты характеризуется ИК-спектрами пропускания, представленными в описании.where M is an alkali metal cation,

- the organic base is a polymer based on an oxyalkylated amine or diamine, R ¹ , R ² , R ³ , R ⁴ - H, alkyl -, aryl - or alkanol groups. The double polysilicate is in the form of particles with a specific surface area of 340-740 m ² / g, the surface of the particles contains a polycation of the organic base in the amount of 0.1-0.2 nitrogen functional groups per 10 nm ² . Binary polysilicates are characterized by the IR transmission spectra presented in the description.

The double polysilicate has a molar ratio of SiO ₂ to M ₂ O, where M is an alkali metal ion (for example, Li, Na, K,), the range of values is from 4: 1 to 12: 1.

The double polysilicate of an alkali metal and an organic base has a pH in the range of at least 10.0 and can reach 11.5 pH units. The determination is carried out using a pH meter-ionomer.

The double polysilicate of an alkali metal and an organic base has a silica content in the range of 20 to 75 wt. % A silica content in the range of 60 to 75% is preferable in order to simplify transportation and reduce transportation costs. Before using the double polysilicate of alkali metal and organic base, it is necessary to dilute to significantly lower concentrations of silicon dioxide. When the content of silicon dioxide in the range from 60 to 75%, the double polysilicate of an alkali metal and an organic base is a white powder, readily soluble in water.

The viscosity of solutions of a double alkali metal polysilicate and an organic base with a silicon dioxide content of 15% to 25% has a value in the range of 1.5 to 25 cps. Viscosity can be measured using known methods, for example, using viscometers in accordance with GOST 33-2000.

The double polysilicate of an alkali metal and an organic base of the present invention is a stable product, when stored for six months at 20 ° C in a sealed package, there is no delamination of the system, precipitation is whiter than 0.1%, no significant change in specific surface area, viscosity increase less than 5 cps.

The specific surface can be measured by titration with NaOH in a known manner, for example, as described by Sears in Analytical Chemistry 28 (1956): 12, p. 1981-1983, the specific surface is the surface of silica-based particles present in a double polysilicate and is expressed in square meters per gram of silica.

The new compound is formed due to the cooperative interaction of sodium polysilicate particles with polyamines by means of hydrogen bonds passing into ionic bonds and the subsequent formation of covalent bonds. The resulting double polysilicate of an alkali metal and an organic base after drying has the ability to dissolve well in water.

The double polysilicate of an alkali metal and an organic base in accordance with the present invention can be obtained in aqueous media from a reaction mixture prepared from sources of silicon dioxide, an alkali metal or ammonium and an organic polybase.

Sources of silica are precipitated silica, colloidal silica, alkali metal silicates and polysilicates.

Organic base sources include tertiary amines, poloxamers, ethylene diamine-based alkylene oxide block copolymers, hydroxypropylated ethylene diamines, alkoxylated diamines, quaternary ammonium bases.

Sources of alkali metal or ammonium are hydroxides, silicate salts of the corresponding alkali metals. Potassium, sodium, lithium can be used as an alkali metal.

Substances used to produce double alkali metal polysilicate and an organic base: liquid sodium glass in accordance with GOST 13078-81, liquid potassium glass in accordance with GOST 18958-73, silicate-containing products of the Silin brand in accordance with TU 2145-014-13002578-2008, and silica sols of the brand " Lakesil »TU 2145-012-618001487-2014 and similar products, lithium hydroxide, potassium hydroxide, hydroxyalkylated amines, hydroxypropylated ethyleneamine, poloxamines, ethylene oxide-based ethylene oxide and propylene oxide block copolymers, quaternary ammonium bases of polyamines, poly ( iallildimetilammony) hydroxide.

The molecular weight of the organic base is at least 1000, the upper limit of the molecular weight is usually up to 5000 g / mol.

A double polysilicate of the specified formula is obtained by reacting a starting material containing silicon dioxide with an alkali metal alkali solution and using an organic base as a reagent, the reaction temperature is 50-160 ° C, the reaction time is from 30 minutes to 8 hours, use less than 8 hours.

After the heat treatment step, the double polysilicate can be concentrated. Concentration is carried out by known methods osmotic methods, evaporation and drying. Concentration is carried out in order to achieve a mass content of silicon dioxide of at least 20% and up to 60%.

Double silicate is in the form of particles with a specific surface area of 340-740 m ² / g, the surface of the particles is coated with an organic polybase, in the amount of 0.1-0.2 functional groups of nitrogen per 10 nm ² .

Binary polysilicates are characterized by infrared transmission spectra, which are indicated in the description.

The invention is illustrated by the following examples.

Example 1

500 g of sodium polysilicate of the brand Silin BH-M with a molar ratio of 5.0 and a SiO content _of 20.3% are diluted with distilled water to 1000 g. Then, with vigorous stirring, an organic base — an aqueous solution of an ethylene oxide block copolymer — is introduced into an aqueous solution of sodium polysilicate and propylene oxide (BS EO / PO) with a molecular weight of 5000 at a concentration of 10% in an amount of 25 g with a dosing rate of 1 dm ³ / hour.

After that, the resulting solution is heated at a temperature of 90 ° C for 5.0 hours, then concentrated to a SiO ₂ content _of 21.5%, the product is cooled to 20 ° C. The resulting product is a double polysilicate of sodium and an organic base of the formula 5.0 SiO ₂ ⋅ Na ₂ O ⋅ 0.05 (N ₂ R ₄ ^1,2,3,4 ) ² O ⋅ 60 H ₂ O and has physico-chemical characteristics presented in table 2.

Example 2

600 g of an aqueous solution of potassium hydroxide with a concentration of 7% with stirring is mixed with 600 g of an aqueous solution of a hydrosol of silicon dioxide with a density of 1200 kg / m ³ with a content of SiO _{2 of} 30.0% and heated to a temperature of 80 ° C with stirring for 1 hour, after when the solution becomes transparent with stirring, an organic base is introduced into the resulting aqueous solution of potassium polysilicate, an aqueous solution of hydroxypropylated ethylene amine (OD EDA) with a molecular weight of 1000 at a concentration of 10% in an amount of 125 g with a dosing rate of 1 dm ³ / hour.

After that, the resulting solution was heated at a temperature of 120 ° C for 3.0 hours, then concentrated to a SiO ₂ content _of 25%, the product was cooled to 20 ° C. The resulting product is a double polysilicate of potassium and an organic base of the formula 8 SiO ₂ ⋅K ₂ O⋅0.5 (NR ₄ ^1,2,3,4 ) ₂ O⋅45H ₂ O and has physicochemical characteristics shown in table 2 .

Example 3

600 g of an aqueous solution of lithium hydroxide with a concentration of 3% with stirring is mixed with 600 g of an aqueous solution of a hydrosol of silicon dioxide with a density of 1200 kg / m ³ with a content of SiO _{2 of} 30.0% and heated to a temperature of 60 ° C with stirring for 1.5 hours , after the solution becomes transparent, with stirring, an organic base is introduced into the obtained potassium polysilicate aqueous solution - an aqueous solution of poly (diallyldimethylammonium) hydroxide (PDADMAG) with a molecular weight of 2500 at a concentration of 10% in an amount of 50 g with a dosing rate of 1 dm ³ / h.

After that, the resulting solution is heated at a temperature of 160 ° C for 0.5 hours, then it is concentrated to a SiO2 content of 45%, and the product is cooled to 20 ° C. The resulting product is a double lithium polysilicate and an organic base of formula ₂ 12SiO2⋅Li O⋅0,2 (NR ₄ ^1,2,3,4) O⋅24H ₂ O ₂ and has the physicochemical characteristics listed in Table 2.

Example 4

600 g of an aqueous solution of sodium silicate with a concentration of 6% are mixed with an organic base with stirring - an aqueous solution of ethoxylated alkylamine (OE AA) with a molecular weight of 2400 at a concentration of 10% in an amount of 80 g with a dosing rate of 1 dm ³ / h, then 600 g are introduced an aqueous solution of a hydrosol of silicon dioxide with a density of 1200 kg / m ³ with a SiO ₂ content _of 30.0%. After that, the resulting solution is heated at a temperature of 50 ° C for 8.0 hours, then concentrated to a SiO2 content of 65%, the product is cooled to 20 ° C. The resulting product is a double sodium polysilicate and an organic base of formula 4SiO ₂ ⋅Na ₂ O⋅0,1 (NR ₄ ^{1,2,3, 4)} O⋅10N ₂ O ₂ and has the physicochemical characteristics listed in Table 2.

The ratio of components, the operating conditions for the production of double alkali metal polysilicates and an organic base are given in table. 1. Physico-chemical characteristics and formulas of the obtained products are presented in table.2.

The concentration of silicon dioxide in the double polysilicate is determined by the method described in the monograph (Euler R. Chemistry of silica M .: Mir, 1982, part 1, p. 265).

The elemental composition of the obtained double polysilicates of an alkali metal and an organic base is determined using physicochemical methods of analysis:

- the mass concentration of alkali metal ions is determined by acidimetric titration of solutions of double polysilicates;

- the mass concentration of silicon dioxide SiO ₂ is determined by the gravimetric method by converting silicon oxide into volatile silicon tetrafluoride by reaction with hydrofluoric acid;

- the mass concentration of the functional groups of nitrogen of the organic base is determined by non-aqueous titration with perchloric acid in dioxane or isopropyl alcohol.

As can be seen from examples of specific performance and data on the elemental composition, a colloidal double polysilicate has the structural formula:

where M is an alkali metal cation.

The resulting double polysilicate can be used as a binder to obtain thin coatings on metal, plastic and other materials, to obtain adhesives, components of heat-resistant paints used in various fields of technology.

Example 5 for use.

An aqueous solution of sodium double polysilicate and an organic base prepared in accordance with Example 1 was applied to steel plates. After drying for 5 hours at room temperature, adhesion was determined. The adhesion of films on metal plates was determined in accordance with GOST 31149-2014. Paintwork materials. Determination of adhesion by trellised notch. The adhesion of the film of the starting sodium polysilicate is 4 points, the adhesion of the film of the double sodium polysilicate obtained in accordance with example 1 is 1 point.

Thus, a double polysilicate can be used as a binder for thin coatings on metal.

A brief description of the drawings.

The accompanying description of the drawings shows:

FIG. 1 - IR transmission spectrum of a sample of double sodium polysilicate and an organic base synthesized in accordance with example 1.

FIG. 2 - IR transmission spectrum of a sample of a double potassium polysilicate and an organic base synthesized in accordance with example 2.

FIG. 3 - IR transmission spectrum of a sample of lithium double polysilicate and an organic base synthesized in accordance with example 3.

IR spectra were recorded on a Vector-22 IR Fourier spectrometer. The range of the spectrometer is the average infrared region of 4000-400 cm ^-1 . The transmission spectra were recorded in the form of press-ons in potassium bromide.

Bibliography:

1 Ayler R. Chemistry of Silica. In 2 vols. M: Mir, 1982.

2 Figovsky O., Beilin D. Advanced Polymer Concretes and Compounds, 2013, 267 P.

3 Korneev V.I., Danilov V.V. Soluble and liquid glass. St. Petersburg: Stroyizdat, St. Petersburg, 1996.

4 Porter M.R. Handbook of Surfactants. Blackie, Glasgow (UK), 1994.

5 Figovsky O.L., et al. Advances in the Use of Nanotechnology in Building Materials, Nanobuild, v. 3, 2012. p. 6-21.

Claims (3)

A double polysilicate of an alkali metal and an organic base having the formula

where M denotes an alkali metal cation,

- organic base - a polymer based on oxyalkylated amine or diamine, while the double polysilicate is in the form of particles with a specific surface area of 340-740 m ² / g, the surface of the particles contains a polycation of the organic base in the amount of 0.1-0.2 nitrogen functional groups per 10 nm ² and has characteristic absorption bands of the infrared spectrum in the regions of 1026-1121 cm ^-1 , 1634-1651 cm ^-1 .

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