RU2491312C2 - Bituminous varnish with improved characteristics - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to varnish-and-paint material, modified by nano-dispersive layered silicates, dispersed in solution of highly molecular compound by means of ultrasonic processing. Varnish is applied for procession of products and constructions from concrete, metal, wood, bricks and other materials. Varnish base represents bitumen of brand G and solvent, which represents mixture of xylene and white spirit in ratio 1:1. Bituminous varnish additionally contains organophilic nano-dispersive layered silicates, distributed in solution of bituminous resin. Ratio of bitumen of brand G, xylene, white spirit and organophilic nano-dispersive layered silicates constitutes respectively 1-1.12:0.58-0.65 0.58-0.65:0.03.

EFFECT: modified in such way varnish-and-paint material has improved characteristics, in particular, increased moisture-protecting properties, and this does not require fundamental changes of the technological process of its production.

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Description

The present invention relates to a method for modifying paints and varnishes with nanodispersed layered silicates dispersed in a solution of a high molecular weight compound using ultrasonic treatment. Modified by the claimed method, the paint and varnish material has improved moisture-proofing properties, and no fundamental changes in the technological process of its manufacture are required.

Bitumen varnish is a ready-to-use mortar prepared using certain brands of bitumen, various additives and an organic solvent. Bitumen varnish is widely used for processing (for a variety of purposes) products and structures made of concrete, metal, wood, brick and some other materials.

The industrially produced bitumen varnishes have insufficient resistance to the action of adverse external conditions (humidity, temperature changes, acid effect).

In the literature there is information about the modification of bitumen varnishes with synthetic rubbers. The composition presented in [1] has improved moisture resistant properties compared to the industrially produced bitumen varnish, has a wide range of applications, but it cannot be used at elevated temperatures, has low frost resistance and requires preliminary processing of the painted surface. A waterproofing coating, including bitumen, synthetic rubber, plasticizer and solvent, [2] has increased heat resistance and wear resistance, but its properties are highly dependent on the original organic synthetic rubber modifier and the accuracy of the process of their preliminary mixing.

Known bitumen-polymer composition [3], which includes, in addition to a solution of bitumen in methylene chloride, an epoxy oligomer and an amine or polyamide hardener. The specified composition has barrier properties that exceed the properties of industrially produced bitumen varnish, but the coating film obtained during polymerization is inelastic, it may crack, in addition, the protective composition must be applied only with the use of a preliminary primer. A serious drawback of the composition is also its limited shelf life.

As a prototype of the invention adopted bitumen based on bitumen and solvent, which is a mixture of xylene and white spirit in a ratio of 1: 1 [4]. The disadvantage of this bitumen varnish is that the paint coating based on bitumen is characterized by insufficient moisture resistance and low resistance to aggressive environments.

The technical result of the claimed invention is bitumen varnish with improved characteristics. The technical result is achieved due to the fact that bitumen grade G is used as a bitumen and additionally contains organophilic nanodispersed layered silicates distributed in a solution of bitumen resin, and the ratio of grade G bitumen, xylene, white spirit and organophilic nanodispersed layered silicates is 1-1, respectively 12: 0.58-0.65: 0.58-0.65: 0.03.

The figure 1 presents a schematic representation of the structure of the modified bitumen varnish, showing the mechanism of action of the protective coating.

An advantage of the invention is to increase the moisture-proof properties of bitumen varnish, in the absence of the need for significant changes in the technological process of its manufacture.

The essence of the invention lies in the fact that layered silicates modified with quaternary amines, due to ion-exchange reactions occurring on the surface of silicate plates and the addition of bulk ammonium ions, in contrast to modified layered silicates, have pronounced organophilic properties, which allows dispersion particles of modified layered silicates in organic solvents. Under the influence of ultrasound on a mixture of an organic solvent with a certain amount of modified layered silicates introduced, a gradual separation of the layered silicates particles occurs with the introduction of solvent molecules into the interlayer space of the particles due to ionic interaction with amine cations. The introduction of bitumen into the mixture, with continued ultrasonic treatment, allows to achieve a completely exfoliated structure of the layered silicate particles, which is preserved even after the mixture ceases to sound, which does not occur when the particles of layered silicates are directly introduced into the bitumen varnish.

To confirm the claimed result, a modified bitumen varnish was made according to the following procedure. The layered silicates modified with a quaternary ammonium base (the ready-made commercially available Benton-32 was taken as an example) were dispersed in a solvent on an ultrasonic disperser like UZD 1-0,063 / 22 for 10 minutes under normal conditions. This mode ensured the complete separation of the layered silicate plates. As a solvent, a mixture of xylene and white spirit in a ratio of 1: 1 was used. The volume of the voiced mixture was 0.5 l, the concentration of layered silicates in the solvent was 16 mass%. With continued ultrasonic treatment, a mixture of grade G bitumen and solvent in a ratio of 1: 1.12-0.89 was introduced into the solvent mixture with organophilic nanodisperse layered silicates, the ratio of bitumen, xylene, white spirit, layered silicates being 1-1.12, respectively : 0.58-0.65: 0.58-0.65: 0.03. Ultrasonic treatment of the mixture was carried out for 10 minutes on an ultrasonic disperser type UZD1-0,063 / 22.

The finished product is a modified bitumen varnish with the content of organophilic nanosized layered silicates in an amount of 1.5% wt.

The principle of the protective effect of the inventive bitumen varnish is shown in the diagram (see figure 1), which shows the winding path 1 of the diffusive passage of water molecules through exfoliated plates of modifier 2 in the thickness of the polymer film 3.

The mechanical properties of the obtained modified bitumen varnish are in accordance with GOST 312-79. [four]

The resistance of the claimed bitumen varnish in hydrochloric acid compared with the industrially produced bitumen varnish BT-5100 increased by 50%.

The moisture resistance of the inventive bitumen varnish compared with the commercially available bitumen varnish BT-5100 increased by 50%.

Test results confirm the claimed result.

Information sources

1. TU 38.302-16-385-91. Mastic automobile bituminous and rubber.

2. RF patent No. 2140953 dated 03/18/1998, IPC C09D 195/00, publ. November 10, 1999

3. RF patent No. 2002778 dated 06/28/1991, IPC 5/08, C09D 163/02, C09D 195/00, publ. November 15, 1993

4. GOST 312-79 Varnish BT-5100. Technical conditions

Claims (1)

Bitumen based on bitumen and solvent, which is a mixture of xylene and white spirit in a 1: 1 ratio, characterized in that grade G bitumen is used, and additionally contains organophilic nanodisperse layered silicates distributed in a solution of bitumen resin, and the ratio bitumen grade G, xylene, white spirit and organophilic nanosized layered silicates is respectively 1-1.12: 0.58-0.65: 0.58-0.65: 0.03.

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