RU2777340C1 - Composition for hydrophobization and preservation of wood - Google Patents

Abstract

FIELD: woodworking industry.

SUBSTANCE: invention relates to the field of woodworking industry, in particular to compositions for hydrophobization and preservation of wood and products of wood. The composition for hydrophobization and preservation of wood includes used vegetable sunflower oil containing unsaturated fatty acids: oleic, stearic, linolenic, linoleic, palmitic, a hydrophobic agent – siccative, and coniferous wood flour, at the following ratio of components of the composition, wt. %: used vegetable sunflower oil – 95, siccative – 1-4, coniferous wood flour – 1-4.

EFFECT: reliability of protection of wood from water and moisture is increased.

1 cl, 6 tbl

Description

The invention relates to the field of woodworking industry and can be used for hydrophobization and conservation of wood and wood products.

Wood is a complex natural polymeric material that is exposed to water and moisture due to the presence of a large number of hydroxyl groups in its structure. As a result of the impact of water, there is a change in the physical and mechanical properties of wood, a decrease in dimensional stability and, as a result, a reduction in the service life of wood products. In addition, the impact of water and moisture significantly increases the possibility of the formation of wood-destroying fungi and microorganisms, which significantly reduce the integrity of the wood structure.

Traditionally, wood hydrophobization is carried out by blocking hydroxyl groups by filling the capillary-porous structure of wood. Therefore, one of the possible ways to eliminate these shortcomings of wood as a structural material is its impregnation with special composite water-repellent compositions.

A composite composition for wood hydrophobization is known (Pat. RF No. 2729741; IPC B27K 3/34; publ. 08/11/2020), including petroleum bitumen, used motor mineral oil obtained from base distillate oil, technical paraffin.

This composite composition has a relatively high depth of impregnation of wood, provides high water resistance, gives resistance to the main types of wood-destroying fungi and microorganisms. However, this composition has a significant drawback: it contains used motor mineral oil, which makes it possible to significantly increase the depth of impregnation, but the use of this component does not allow the use of the resulting products in residential premises, which significantly narrows the scope of the composition.

Known water-repellent composition (Pat. RF No. 2621116; IPC C09K 3/18, B27N 1/00, B27N 3/00, C04B 24/38, C08L 61/06, C08L 91/06, C08L 97/00, C08L 97/02 , C09D 7/12, D21C 9/00, D21H 21/16; publ. 05/31/2017), consisting of lignosulfonic acid and its salt, hydrophobizing agent, liquid medium. The hydrophobizing agent of the composition includes rosin, paraffin oils and other components. The present invention makes it possible to reduce the absorption of water and to impart dimensional stability to the compressed wood.

A significant disadvantage of this hydrophobizing composition is its multicomponent nature, which complicates

production process for its production. In addition, the composition of this composition includes organic compounds (isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol) having a third hazard class and high flammability, which affects the environmental friendliness and fire resistance of the composition.

A known method of impregnating wood and timber under pressure (Pat. RF No. 2414346; IPC B27K 3/08, B27K 3/34, B27K 3/50, C09D 15/00; publ. 20.03.2011) crude vegetable tall oil, resin and/ or fatty acids isolated from it.

The disadvantages of this method are the use of crude vegetable tall oil, resulting in a low ability of the impregnating composition to protect the wood from decay, as well as its unpleasant odor, which occurs during acid treatment. Another disadvantage of this method is the significant seepage of the impregnating composition through the surface of the wood, which adversely affects the ease of use.

A preservative for wood is known (Pat. RF No. 2422265; IPC B27K 3/50, B27K 3/34, B27K 3/52, C11B 13/00; publ. 06/27/2011), including vegetable oil containing unsaturated fatty acids: oleic, stearic, linolenic, linoleic, palmitic. As a vegetable oil, vegetable tall oil is used after the removal of neutral components from it, which act as a source of nutrition for putrefactive fungi, and compounds that cause the passage of esterification reactions. Taken as a prototype.

This impregnating composition, due to the removal of sources for nutrient media of wood-destroying microorganisms, is an effective water repellent (antiseptic), however, in the process of extracting neutral components, useful substances (monoterpenes, diterpenes, phenols) are also removed, which can give wood resistance to putrefactive microorganisms. Also, at the saponification stage, when removing neutral components, alkali solutions (KOH, NaOH, LiOH) are used, which are removed as waste after saponification, which reduces the economic feasibility of the process. The multi-stage purification process is carried out at relatively high temperatures (up to 200°C), which further complicates the process of obtaining purified vegetable tall oil for wood impregnation.

The inventive composite composition for hydrophobization and preservation of wood is obtained by mixing the main components of the composition without further purification. The ease of obtaining and using the composite composition expands the scope of its possible application.

The aim of this invention is to develop a composite composition for water repellency and preservation of wood, providing high levels of water resistance and moisture resistance, as well as low values of kinematic viscosity during impregnation, positively affecting the impregnation of wood.

This is achieved by the fact that the composite composition for hydrophobization and preservation of wood, including vegetable oil containing unsaturated fatty acids: oleic, stearic, linolenic, linoleic, palmitic, according to the invention, additionally contains a hydrophobizing agent - a desiccant, for example, NF-1, and flour coniferous wood, used vegetable sunflower oil is used as vegetable oil, with the following ratio of the components of the composition, wt. %: waste vegetable sunflower oil - 95, desiccant - 1-4, softwood flour - 1-4.

The presence of a desiccant, for example, NF-1, which has a hazard class of 4, in the composite composition accelerates the process of its drying, increases the adhesion of the composition to wood, and also improves the decorative properties of the resulting products. The desiccant is mixed with spent vegetable sunflower oil, thus forming a homogeneous mixture. Coniferous wood flour increases the water-repellent properties of the composition due to the presence of resin acids, and also makes it possible to provide the necessary kinematic viscosity to the composite composition.

Wood impregnation was carried out in a hot bath at a wood moisture content of not more than 25% (GOST 20022.6-93). Samples of birch wood with the size (GOST 16483.20-72) required for testing for water, moisture absorption and swelling in the tangential and radial directions were placed in the impregnating liquid heated to a temperature of 115–125°C and kept for 20 minutes. The impregnating composition was evaluated according to the following parameters: water absorption for 30 days in distilled water (GOST 16483.20-72), swelling in the tangential and radial directions, volumetric swelling (GOST 16483.35-88), moisture absorption (GOST 16483.19-72). At least 5 samples were used to determine each of the indicators. The kinematic viscosity was determined on a VPZh-4 viscometer (GOST 33768-2015) at temperatures of 20 and 120°C. The wetting angle of wood with distilled water was measured by the sessile drop method on a goniometer assembled in the laboratory using the HIview 10 program. A drop of distilled water was applied to the wood surface with a 0.01 ml microsyringe. The image was recorded using a portable microscope camera Digital Microscope (Ruihoge, China) and fixed for 1, 30, 60, and 90 s.

The examples given show various options for obtaining the claimed composite composition for hydrophobization and wood preservation. In all described examples, the composite composition includes waste vegetable sunflower oil containing unsaturated fatty acids (oleic, stearic, linolenic, linoleic, palmitic), hydrophobizing agent - NF-1 desiccant and softwood flour.

Example 1

The composition contains, wt. %:

Waste vegetable sunflower oil - 95;

Desiccant - 1;

Softwood flour - 4.

The presence in the composition of a larger amount of coniferous wood flour makes it possible to provide acceptable indicators of water resistance with high dimensional stability, as well as to reduce the consumption of the impregnating composition by increasing its kinematic viscosity.

Example 2

The composition contains, wt. %:

Waste vegetable sunflower oil - 95;

Desiccant - 2;

Softwood flour - 3.

An increase in the percentage of desiccant has a positive effect on water-resistant performance, while increasing the hydrophobization of the treated wood surface. However, at the same time, there is a slight decrease in dimensional stability due to a decrease in the concentration of softwood flour.

Example 3

The composition contains, wt. %:

Waste vegetable sunflower oil - 95;

Desiccant - 3;

Softwood flour - 2.

In this example, the composition contains 3 wt. % desiccant, which significantly increases the content of the impregnating composition in wood relative to examples 1 and 2, and also increases the water resistance of wood.

Example 4

The composition contains, wt. %:

Waste vegetable sunflower oil - 95;

Desiccant - 4;

Softwood flour - 1.

The largest amount of desiccant in the composite composition has a positive effect on its content relative to examples 1-3, and also increases the dimensional stability of the impregnated wood. At the same time, due to a smaller amount of coniferous wood flour, there is a decrease in kinematic viscosity and an increase in the contact angle of wetting wood with water.

Indicators of wood impregnated with the claimed composite composition for hydrophobization and wood preservation, for examples 1-4 are presented in tables 1-6.

The developed composite composition for hydrophobization and preservation of wood mainly consists of a cheap component - waste vegetable sunflower oil, which contains unsaturated fatty acids (oleic, stearic, linolenic, linoleic, palmitic), which makes it possible to give wood high levels of water and moisture resistance, shape stability . The introduction of a desiccant into the composite composition accelerates the drying process of the composition, increases the adhesion of the composition to wood. Impregnation with this composite composition will reliably protect wood from water and moisture, which will expand the possibilities of using wood materials in conditions of negative environmental impact and use the resulting products in residential premises.

Claims (1)

Composite composition for hydrophobization and preservation of wood, including vegetable oil containing unsaturated fatty acids: oleic, stearic, linolenic, linoleic, palmitic, characterized in that it additionally contains a hydrophobizing agent - a desiccant, for example, NF-1, and softwood flour, used vegetable sunflower oil is used as vegetable oil, with the following ratio of the components of the composition, wt. %: waste vegetable sunflower oil - 95, desiccant - 1-4, softwood flour - 1-4.