SU1214420A1 - Method of modifying wood - Google Patents

Description

one

The invention relates to a method for manufacturing a modified wood and can be used in the woodworking industry.

The purpose of the invention is to improve form stability, reduce water and moisture absorption of modified wood, reducing the energy intensity of the method of its production.

It is known that in the acylation of wood with acid anhydrides, the process of replacing the hydrogen atoms of the hydroxyl groups of the components of the woody substance by acylated groups takes place.

Use as an acylating agent reagent benzoyl chloride having the structural formula

°

leads to the addition of a more bulky and hydrophobic benzoyl group to the composition of the macro ™ molecules of the wood components, which significantly reduces the water absorption of acylated wood, improves its form stability, diffusion processes of water penetration into microfibrillar and amorphous wood thing. At the same time, the introduction of the benzoyl group leads to a decrease in the polarity of the wood components, which also reduces the diffusion of water.

In addition, acid chlorides, which include benzoyl chloride, due to the high mobility of the chlorine atom, are more reactive compounds with relatively simple anhydrides, which are as follows: 144202

It makes it possible to reduce the temperature of the modification method,

The technological process of the method is as follows.

;; For all examples (see Table 1)

birch blanks with a moisture content of 6–8%, a density of 600–620 hg / m, and dimensions of 20 ”20” 10 and 22.5 mm were used (the latter size

10 along the fibers).

Benzoyl chloride was used to carry out the process. The wood blanks were evacuated at a residual pressure of 10–16 mm Hg.

13 for 20 minutes, soaked with benzoyl chloride, its excess was removed, and the samples were kept in air at 55-75 ° C for

20 6-10 h.

Modes of wood modification are given in table.1.

Properties of modified wood are presented in table 2,

23

t

Thus, the modified wood obtained by the proposed method has a moisture absorption of 28–39% less by 48–72%, while the shape stability of the samples improves in the rational and tangential directions by 26–35 and 20-28% at a decrease in temperature of 35 treatment at 45 -55 ° C. The energy intensity of the method is reduced 1.5-2.0 times.

The economic effect is achieved by increasing the durability of products operating under conditions of variable humidity, and the use of such a relatively inexpensive large-tonnage reagent, such as benzoyl chloride.

Table 1

thirty

40

Temperature, ° С Time, h

120-125 8-10

455565 7585

1210884

Table 2

Claims (1)

METHOD OF MODIFICATION OF WOOD, including its evacuation, impregnation with an acylating reagent and subsequent heat treatment, characterized in that, in order to reduce water and moisture absorption, increase the form stability of modified wood and reduce the energy intensity of the method, benzoyl chloride is used as an acylating reagent, heat treatment is carried out at 55-75 ° C for 6-10 hours