SU994262A1 - Composition for protecting wood - Google Patents

Description

The invention relates to compositions used to protect wood from cracking and rotting, and can be used in forestry. the woodworking industry and other branches of the national economy that use wood. A known composition for the protection of wood, including rezol phenol maldehyde resin tlT. The disadvantage of the composition is that, in order to form a protective coating, it is necessary to pre-apply on the reediators, which doubles the labor costs in its application. Opening the composition into cold (at a temperature below 15 ° C) and wet weather does not occur. This makes it difficult to use it in the early spring period, when large stocks of winter-felling timber are stored in warehouses and protective treatment is especially necessary. Composition known To protect wood, including phenolic-phenol-formaldehyde resin and ethyl alcohol {23. However, bakelite lacquer has several disadvantages. The coating formed from it does not have sufficient ductility and cracks when the wood is wet deformed in atmospheric conditions after 2-3 months, and in the case of high-temperature drying in a shorter time, it ages and collapses. In addition, bakelite lacquers used for wood preservation contain up to 12% free phenol, which adversely affects health. working. The purpose of the invention is to improve the quality of wood protection and reduce the content of free phenol. The goal is achieved by the fact that the proposed composition additionally contains a wood tar drink and an acetal alcohol solvent in the following ratio of components, Resole phenol formaldehyde resin 12-30 Ethyl alcohol 8-20 Wood tar peck-19-30 Acetal alcohol solvent31-50 The invention is illustrated with the following examples. The composition in laboratory conditions is made by mixing tank

lbs lacquer lbs-1, containing: 60 wt.% resin of phenol-formaldehyde resole type and 40 wt.% ethyl alcohol, and a solution containing 38% pitch of wood tar Nogo and 62% acetal alcohol alcohol ratio of wood preservative composition

In the recipe in the ratio of recipes - 1-50: 50, And - 30:70 and W - 20:80.

The ratio of the components listed in the table. one.

Table 1

Fe noloformaldehyde resin rezol type

Alcohol

20 ethyl

Wood tar pitch19

Acetal alcohol rast31

The main indicators characterizing the properties of the obtained SIAstav on the properties of the compositions for the protection of wood

Conditional viscosity according to VZ-4 at + 20 + 1®С, s

nineteen

The content of free phenol, wt.%

As can be seen from the table. 2, the introduction of the wood-pitch dissolved in the acetal alcohol solvent into the composition makes it possible to reduce its

12

18

12

thirty

26

50

44

Compared with the well-known table. 2

table 2

17

15

90

$ 0

viscosity and thereby make it possible to mechanize its application. At the same time, the decrease in the content of phenol-formaldehyde resin with

60% to 12-30% leads to a decrease in the content of free phenol from 10 to 2-5%. This significantly reduces the toxicity of the composition to humans.

Determination of the protective properties of the coatings, forming during the application of the compositions, is carried out according to the generally accepted method. Samples of beech wood with a size of 50x50x50 m with a moisture content of about 60% are coated with formulations made according to 1-Ш recipes and a known composition - bakelite lacquer, after which they are subjected to atmospheric drying in laboratory conditions for 30

Loss of moisture by protected samples,% to initial mass of samples

After 10 days of drying

After 20 days of drying

After 30 days of drying

Absolute humidity of samples after 30 days of drying,% As can be seen from the table. 3, the evaporation of moisture from samples protected by the composition (), with atmospheric drying is less, and the final moisture content of the samples is higher than when using the known bakelite lacquer. The coatings formed by the l-Iil composition are not destroyed by the deformation of the samples as a result of drying, under the action of water and high temperature. At the same time, on the coatings formed by the known bakelite lacquer, as a result of atmospheric drying, minor disturbances were formed, and after dipping samples into water, 10-15% of the surfaces of the coatings were completely destroyed and peeled off, which

days at air temperature 20-24 С and relative air humidity 80-90%. Samples are weighed, and the loss of moisture and their final moisture is judged on the vapor permeability of coatings. To determine the effect of liquid moisture on coatings, atmospheric dried protected samples are dipped into water for 24 hours. The effect of high temperature is determined by placing the protected samples for 8 hours in an oven at 100 + 1 ° C. Data moisture loss samples after 10.20 and 30 days of atmospheric drying and the final moisture content of the samples are given in table. 3

Wood protection table

8.6 9.2 10.6 13.8

12.3 13.3 16.0 20.4

15.4 16.5 20.5 24.1

Claims (2)

44.0. 38.0 35.3 29.4 led to the formation of cracks in the wood. Thus, the introduction of wood tar pitch dissolved in acetal alcohol solvent into the composition makes it possible not only to reduce its harmfulness and, as a result of a decrease in viscosity, to mechanize its application, as well as to improve the quality of protection. The invention Composition for the protection of wood, including resol phenol-formaldehyde resin and ethyl alcohol, O TL and 7 9942628 due to the fact that, for the purpose of Sources of Information, increase the quality of protection wood-Bd attention during examination and reduce the content of free phenol, the composition additionally contains1. USSR author's certificate wood tar pitch and acetalespir - No. 315604, cl. In 27 K 3/12, 1970. solvent at the next co 2. Karasev B.C. Bakelite varnish the ratio of components, wt.%: for protection of furniture roughs from phenol forgings against cracking. Abstracts dokmal {1hidna resin 12-30ladov scientific and technical conference Ethyl alcohol 8-20 Achievement of technology and technology of wood-based pitch 19-30 wood-processing industry, Acetal alcohol 1 Kiev, UkrNIIMOD, 1975, pp.62-63 solvent 31-50 (prototype).