RU2645132C2 - Modified phenol-formaldehyde resin for the manufacture of wood glow materials and the method of manufacture of the modification - Google Patents

Abstract

FIELD: wood industry.

SUBSTANCE: modified phenol-formaldehyde resin includes components in the following ratio, wt %: Phenol-formaldehyde resin (70-95); as a modifier of pectol (5-30). To prepare pectol, chemicals are prepared: tall oil and pitch. Load chemicals into the emulsifier and cook with a continuous stirring mixture of 60% pitch of tallow with 40% tallow oil for 60 minutes when heated by steam to a temperature of at least 70°C.

EFFECT: improving the quality of phenol-formaldehyde adhesives, increasing the strength of the adhesive joint, improving the environmental friendliness of production through the use of sulphate-cellulose waste.

2 cl, 6 tbl

Description

Pectol modifier characteristic

Known modified phenol-formaldehyde resin, including SFL-3013 phenol-formaldehyde resin, and a modifier is an extract of bark of coniferous trees with water or 3-5% aqueous solution of sodium hydroxide, or 3-5% aqueous solution of isopropyl alcohol and paraforms (RU 2440890, publ. 01.27.2012 , Bull. No. 45 - prototype).

The disadvantages of the known modified phenol-formaldehyde resins are the toxicity of glues and plate materials made with their use, low adhesive strength, high water absorption and water swelling.

The technical task of the invention is to improve the quality of phenol-formaldehyde adhesives by reducing the toxicity of glues and finished products, increasing the strength of adhesive bonding, reducing the consumption of the main components, as well as improving the ecology of the production of glued materials through the use of waste sulphate-cellulose production.

The problem is achieved in that the phenol-formaldehyde adhesive includes phenol-formaldehyde resin SFZh 3013 and pectol.

Pectol is an intermediate product of the wood chemical production of the Bratsk Timber Industry. It is formed by mixing 60% tall pitch with 40% tall oil.

Pectol characteristic:

1. Appearance - a creamy dark liquid.

2. Acid number, mg KOH per 1 g of oil - 84.3.

3. Mass fraction of water,% - 0.3.

4. The number of saponification, mg KOH / 2 g - 99.1.

The technological process of cooking pectol consists of the following operations:

- preparation of chemicals;

- loading chemicals into the emulsifier;

- cooking.

A method of manufacturing a modifier is to maintain tall pitch and light tall oil in a molten state. Tall pitch is pumped into a vertical container with a volume of 4.8 m and a horizontal container with a volume of 6 m ³ located in the cooking compartment of the TsZ-1. To maintain tall pitch in the molten state, one of the tanks is constantly heated with steam coming from the heat point to the coil located at the bottom of the tank. Emulsification is carried out continuously, at least 60 minutes, until a stable concentration of pectol is obtained - 3-6%. Ready pectol is stored with constant stirring and a temperature of 60-70 ° C. Download components for cooking pectol are shown in table 1.

1268 kg of molten tall oil pitch, 1054 kg of light tall oil (up to the mark in the emulsifier) are fed into the emulsifier (V = 2.5 m) and the mixer is turned on. This chemical solution is heated by steam to a temperature of at least 70 ° C, which is supplied from the heat point to the coils located at the bottom of the emulsifier. When the desired temperature is reached, the steam supply is interrupted. Pectol temperature is determined by a thermometer.

The finished pectol is pumped to the supply tanks (V = 14 m ³ ), where it is stored with constant stirring and a temperature of 60-70 ° C (steam from the heat point is supplied to the coils located at the bottom of the tank). The resulting pectol has good adsorption properties, helps to reduce the content of free formaldehyde due to the chemical bonding of phenol-formaldehyde resin with resin acids of saponified tall oil pitch.

Tall oil light - an oily liquid or a mushy mass, practically insoluble in water, but soluble in organic solvents, slowly oxidized in air. Tall oil is produced in accordance with TU 13-0281078-100-90, table 2.

Light tall oil is a complex mixture of numerous compounds of various classes. The study and knowledge of the properties and composition of light oil makes it possible to reasonably approach the choice of a hydrocracking technological scheme. Studies of the physico-chemical properties and group composition of the oil were carried out according to the methods adopted for tall products. The results are presented in table 3.

Light tall oil dissolves pitch well and has a low viscosity (0.0263 n.sec / m ² ). The group composition of light tall oil is presented in table 4.

From table 4 it is seen that light oils consist of the same compounds as tall pitch. Their feature is a high content of neutral substances and low - oxidized. The composition of neutral substances is dominated by hydrocarbons (74.25%), of which 98.6% are aromatic.

The data from tables 3, 4 indicate that light oil, on the one hand, can serve as a diluent for pitch, on the other hand, light oils can be an additional source of aromatic hydrocarbons. During the distillation of tall oil, high boiling neutral substances remain in the bottom residue together with non-volatile and oxidized products - this residue is tall pitch.

Tall pitch has the following physicochemical parameters: softening point - 33 ° C, acid number - 39 mg KOH / g, saponification number - 105 mg KOH / g, mass fraction,%: saponified substances-25.7; oxidized substances - 17.1; resin acids - 24.4; fatty acids - 32.4; density - 1,038 g / cm ³ .

To check the quality of phenol-formaldehyde resin obtained with the modifier, the following adhesive recipes for the manufacture of plywood are presented, which are presented in table. 5.

Plywood glued with different recipes of the adhesive composition was tested for strength when sheared on the adhesive layer and the content of free formaldehyde was determined. The test data are given in table. 6.

Claims (3)

1. Modified phenol-formaldehyde resin, including phenol-formaldehyde resin and pectol, characterized in that the content of components in the resin can be as follows, wt.%: Phenol formaldehyde resin 70-95 Pectol 5-30 2. A method of producing a modifier consists in preparing chemicals, loading chemicals into an emulsifier and cooking while continuously mixing a mixture of 60% tall pitch with 40% tall oil for 60 minutes with steam heating to a temperature of at least 70 ° C.