LV15084B - Composition of concrete coating for floors and method of its production - Google Patents

Description

Description of the Invention

The present invention relates to construction, in particular to technologies for the production of floor self-leveling compounds or floor coatings and methods of obtaining them.

Known state of the art

Currently, various thin layers, which are applied on a fresh or hardened concrete layer, are widely used in the production of self-leveling floors. Thin layers based on polyurethane are often used (US4273912, EP0677494, KR100732124, CN102167544, RU2139897). Thin layers include sand or pebbles (GB2240977) to increase mechanical strength, but such coatings have a thickness not exceeding 1 to 5 mm and lack sufficient mechanical strength and durability. Moreover, applying them to freshly poured concrete is a technologically demanding task. In addition, it should be noted that such thin layers are not suitable for repairing old concrete floors because they have cracks and pits.

Polyurethane-based concrete is also widely used for floor coatings, which enables coatings with a thickness of 10 to 12 mm. Such flooring compositions are manufactured, for example, by TROEGER GmbH, BASF AG, FLOWCRETE UK Ltd and RESDEV Ltd. Of the known compositions, the closest to the application is a polyurethane-based concrete flooring composition containing cement, quartz sand, gravel, water, a polyol component and a polyisocyanate. For the composition, cement and sand are mixed with polyol and then polyisocyanate is added (Ohama Y. Perfomance of Building Materials Using Polyurethane (Part 3). Annual Report of BRI (Kenchiku-Kenkyusho Nempo) April 1968-March 1969. 1969, p. 605 -619). Such floors have high thermal resistance at temperatures from -40 ° C to +130 ° C, high chemical resistance and increased mechanical strength.

The polyol component uses petrochemical feedstocks, but there are several disadvantages to petroleum derived components, such as compound and simple polyester polyols. The use of such compound polyols or simple polyesters contributes to the depletion of oil (non-renewable) resources. In addition, the extraction of polyols is extremely energy intensive, considering that oil must first be extracted (and thus drilled), pumped and transported to a refinery for the production of distilled and purified hydrocarbons, which are subsequently converted into alkoxides and finally into polyols. As the public is increasingly concerned about the environmental impact of this production chain, there is a demand for increased production of eco-friendly products. To reduce oil depletion while meeting these increasing consumer demand, it would be advantageous to partially or fully replace oil-derived simple or compound polyester polyols used in the production of polyurethane elastomers and foams with more universal renewable and environmentally acceptable components (Saunders Д., Фриш Химия полиуретанов (M. Химия, 1968). The use of natural oils, which are mainly used in the food industry, in the production of polyurethane-based concrete increases the cost of the final product. In addition, natural oils have limited resources and require complex pre-treatment operations to purify them.

Purpose and substance of the invention

The object of the present invention is to expand the range of raw materials for floor self-leveling compounds, while limiting the use of polyols derived from vegetable raw materials, and to reduce the cure time of the mixture applied to the floor to be restored.

The objective is achieved by using a mixture of tall oil ester and castor oil in a ratio of 1: 4 to 1 as the polyol in the composition applied as a coating on concrete floors ш containing cement, slaked lime, quartz sand, gravel, water, polyol and polyisocyanate. : 6.

The composition of the concrete floor coating is obtained by a manufacturing process which successively involves the mixing of the mineral components and the addition of the polyurethane-forming components and is characterized by the prior preparation of a mixture of castor oil and tall oil ester, which subsequently forms an emulsion in water. The mineral component group consists of cement, quartz sand, slaked lime and gravel with a particle size of 2 to 8 mm, while the polyurethane-forming components are castor oil, tall oil ester and polyisocyanate.

Tall oil is a dark-colored liquid organic compound with a pungent odor, mainly a mixture of unsaturated resin acids and fatty acids, obtained as a by-product of the sulphate process of cooking cellulose.

Tall oil ester is a liquid with an acid number of 2 to 5 mg KOH / g, a hydroxyl number of 140 to 360 mg KOH / g and a dynamic viscosity of 160 to 200 cP.

DETAILED DESCRIPTION OF THE INVENTION

The content by weight of the components of the self-leveling screed is as follows:

• cement - 10 to 14% • quartz sand - 30 to 35% • slaked lime - 4.5 to 6.0% • gravel with a particle size of 2 to 8 mm - 32 to 33%, • Castor oil - 4.6 to 7% • Tall oil ester - 0.8 to 1.5% • Polyisocyanate - 9 to 11% • Water - 2.3 to 2.8%.

The composition for coating concrete floors is obtained by a process comprising the following sequential steps: emulsifying a mixture of castor oil and tall oil ester in water, mixing the resulting emulsion with a polysocyanate, mixing the resulting mixture in a pre-prepared mixture of cement, quartz sand and slaked lime. The resulting composition is applied to the floor within 8 to 10 minutes, smoothed by frequency.

Table 1 below lists the optimum concentrations of the ingredients for the three different formulations, while Table 2 lists the composition characteristics as compared to the well-known analogue formulation manufactured by FLOWCRETE UK Ltd (for formulations with lower concentrations).

Table 1

Composition,% by weight Composition 1 Composition 2 Composition 3 Cement 11.1 13.1 11.0 Quartz Sand 32.0 30.8 31.7 Slaked lime 4.7 5.9 4.7 Gravel with a particle size of 2 to 8 mm 33.6 32.3 33.3 Castor oil 4.7 4.6 6.0 Tall oil ester 1.0 0.9 1.5 Polyisocyanate 10.3 9.9 9.7 Water 2.6 2.5 2.2

Table 2

Characteristic Composition 1 Composition 2 Composition 3 Flowcrete HF The composition Time at 20 ° C (pot life) min 10th 10th 8th 15th Time at 20 ° C to walk on material surface, h 8th 8th 6th 24th Time at 20 ° C to allow passage of material surface, h 24th 24th 16th 48 Compressive strength, MPa 50.5 42.4 38.7 > 50 Bending strength, MPa 12.6 14.6 10.8 12-20 Adhesion strength, MPa > 1.5 > 1.5 > 1.5 > 1.5

It can be concluded that the physical properties of the offered composition are comparable to the widely used composition of FLOWCRETE UK Ltd, and due to the use of tall oil ester, the composition hardening time has been reduced by 3 to 4 times.

Claims (4)

Claims Composition of a concrete floor covering comprising cement, slaked lime, quartz sand, gravel, water, polyol and polyisocyanate, characterized in that a mixture of castor oil and tall oil ester is used as polyol in a ratio of 4: 1 to 6: 1. Composition according to claim 1, characterized in that its content by weight is as follows: • cement 10 to 14% • quartz sand 30 to 35% • slaked lime 4.5 to 6.0% • gravel 32 to 33% • castor oil 4.6 to 4% 7%, • Tall oil oil ester, 0.8 to 1.5%, • Polyisocyanate, 9 to 11%, • Water, 2.3 to 2.8%. Composition according to claims 1 and 2, characterized in that the gravel particles have a size of 2 to 8 mm. A process for preparing a concrete floor coating composition according to any one of claims 1 to 3, which comprises sequentially mixing the mineral components and adding a previously obtained mixture of polyurethane-forming components to the mixture of mineral components, characterized in that emulsion of water, castor oil and tall oil ester.