SU1208042A1 - Method of producing modified phenol-formaldehyde resin - Google Patents

Description

The invention relates to the production of modified phenol-formaldehyde resins, which can be used as adhesives and bonds for the manufacture of plywood, fibreboard and particle boards and other adhesives from wood.

The purpose of the invention is to reduce the free formaldehyde content in the resin and increase the water resistance of wood products based on it.

Example 1. For the preparation of modified phenol-formaldehyde resins, LSChT lignosulfonates are produced according to TU 13-04-602-81, which are ammonium salts of lignosulfonic acids with admixture of reducing and mineral substances and are characterized by the following properties:

Appearance Uniform guta liquid dark brown Mass fraction,% dry matter, at least 50 ner acTBOpHMjix in water, not more than 1.0.

ash, not more than 2, 0 reducing substances, not

 more than 12

pH of a 20% aqueous solution of lignosulfonate, not less than 4.5. Viscosity conventional for VZ-4 s, not more than 50

In the 5.5-m reactor, equipped with a stirrer, a jacket, and a cooler, 85 wt.h. phenol, 15 May. including lignosulfonates and 0.5 wt.h. bottoms of phenol-acetone production. The reaction mixture is heated to 50 ° C., held for 15 minutes, and cooled to. Then 210 math. Are introduced. water, taking into account the water loaded with raw materials, 24.5 ma.ch. ca. sodium hydroxide and at a reaction temperature of 26 ° C were introduced 92 mas. formaldehyde. When this happens, the reaction temperature increases and the temperature starts to rise and reaches 080422

 mark the beginning of exposure. Exposure at 44-50 ° is carried out for 100 minutes. After the completion of the reaction, the reaction mixture is heated to boiling and allowed to stand for 30 minutes. Then it is cooled until 10.5 ma.h are introduced. caustic soda, eneva heated before and hold for 30 minutes. At the end of the condensation, the resulting emola is cooled and 10 is given and drained.

The resulting resin has the following characteristic: Mass fraction,%

free

15phenol0,013

free

formaldehyde is missing

non-volatile substances46,320 viscosity

(according to VZ-4), p20

Example2. In the reactor, equipped with a stirrer, a jacket and a refrigerator, load 72.5 wt.h. Phenol 25, 27 ppm, lignosulphonates and 5 ppm, cubes of phenol-acetone production, kept for 40 minutes, cooled to 27 seconds. Then 30,200 math. Hours are introduced. water, 22 mach. caustic soda and at ZO C, 83.5 ma.ch. formaldehyde. During the exothermic effect of the reaction, the temperature of the reaction chamber is assessed. At 65-70 ° C, it is kept for 3 min for 70 minutes, then heated to boiling and held for 22 minutes. Then the reaction is cooled. up to 70 ° C, 13.25 math are introduced. caustic soda, again 40 is heated to 82 ° C and held at this temperature for 17 minutes. At the end of condensation, emolu is cooled and drained.

: The resulting resin has the following j characteristic:

Mass dol,% free

phenol0.01

free

formaldehyde sandals

nonvolatile

substances 50,4

Viscosity

(on OT-4), p. 24

Example 3. In the reactor load 60 MAH. phenol, 40 math. lignoyl sulfonates, 2.75 wt.h. residual phenol-acetone production

50

55

properties, maintained at in flow. 27 minutes, cooled down to ZZ C. The reaction mixture was introduced 190 parts by weight. water, 19.5 wt.h. caustic soda and when 75 wt.h. formaldehyde. The mixture is heated and held at 55-60 ° C for 85 minutes. The mixture is then heated to boiling and held for 15 minutes. At the end of the boiling period, the reaction mixture is cooled to 16 wt.h. caustic soda, then heated to and incubated for 5 minutes. At the end of the condensation, the resin is cooled and drained.

The resulting resin has the following characteristic:

Mass fraction,% free phenol

free formaldehyde non-volatile substances

Viscosity

(on VZ-4), with

For the manufacture of plywood, to the image of the resins, obtained by the known and proposed methods in accordance with the examples given, add chalk and wood flour in the following ratio, parts by weight:

Resin100

Mel10

Wood

flour3

Based on the obtained adhesive, the production of plywood samples was carried out as follows.

A glue sheet of 1.5 mm with a thickness of 1.5 mm, intended for the inner layer of plywood, is applied at the rate of 125 g / m. From a single sheet with an applied adhesive layer and two sheets without an adhesive, designed for the outer layers of plywood, a three-layer bag is assembled with mutually perpendicular arrangement of the fibers. Of the three three-layer packets, one common packet, pre-subres, 014

Missing 48.2 27

1208042.

They put it in a cold press at a specific pressure of 10 kgf / cm for 10 minutes and then pressed at 125 +, specific pressure 5-20 kgf / cm and a pressing time of 9 minutes.

Table 1 presents the results of testing samples of plywood obtained on the basis of resins according to the proposed and known methods.

 Resin samples obtained according to the following examples, after dilution with water, are also used in the manufacture of solid fiberboard. Chip Content

wood species: softwood 8%, leaf1 92%.

 Table 2 presents the results of tests of fiberboard produced on the basis of resins according to the known and proposed methods.

The resin obtained by the proposed method contains almost no free formaldehyde, which improves the conditions for its further processing in the production of plywood and fibreboard and their subsequent operation.

As can be seen from the tables, the obtained resin provides an increase in the water resistance of wood products, which is characterized: for plywood, with an increased value of breaking voltage when the adhesive layer is peeled off after one hour of boiling in water, which, in accordance with GOST 20907-75, must be at least 1.47 MPa (the known resin is not suitable for the production of plywood due to its low water resistance), for fibreboard - by reducing the water absorption by 12-25

and swelling by 32-45%.

Taking into account the fact that lignosulfonates and bottoms of phenol-acetone production are cheaper than phenol, the cost of the finished resin is significantly reduced.

T a b l and c a 1

Plywood Performance

Famous Suggested by examples

1 2 3,

Breaking stress specimens 1.96 1.67

after boiling, wrinkling of the adhesive layer

water in currents 1 h, MPakleevo well layer

Ii juii

Wood Fiber Resin Based Plate Performance

Famous Offered by

examples

1 I 2 I 3 Density, 1007-1044 909. 1047 958

Destructive stress at static bending, MPa 42.5-43.3 46.1 51.7

Water absorption.

24 hours 24.4-25.2 19 18.3 21.8

Swelling by

thickness in 24 hours 16.8-17.7 10.8 9.6 11.3

Compiled by B. Grishin Editor N. Kishtulinets Tekhred O. Vashchishina Corrector L. Pilipenko

Order 175/32 Circulation 471 Subscription

VNISHI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch ShSh Patent, Uzhgorod, st. Project, 4

Claims (1)

METHOD FOR PRODUCING A MODIFIED PHENOFORM FORMAN-DEHYDE RESIN by condensation of a phenol-containing agent, formaldehyde and a modifying agent based on ammonium salts of lignosulfonic acids with a viscosity of BZ-4 no more than 50 s in the presence of caustic sodium upon heating, which is different in that the form .15-40 parts by weight ammonium salts of lignosulfonic acids, a mixture of 60 85 parts by weight phenol and 0.5-5.0 parts by weight ; bottoms of phenolacetone production, containing, wt. X: Phenol 2-10 Cumylphenol 23-50 Dimethylphenylcarbinol 2-20 Acetophenone * 6-Methylstyrene Resinous Βε 1, 5-25 0.05-6.0 The rest of the substance is maintained at 40-50 ° C for 1540 minutes, cooled to 20-35 ° C, 190-210 parts by weight are added. water, 19.5) May 24.5. including caustic soda, 75 92'm.h. formaldehyde, the resulting mixture is heated to 44-70 ° C and held for 70-100 minutes, heated to boiling and held for 15-30 minutes, cooled to 65-70 ° C, add 10.5-16 wt.h. caustic soda, heated to 75-88 ° C and incubated for 330 minutes so