RU2057773C1 - Composition for splint-slab plates - Google Patents

Abstract

FIELD: wood working industry. SUBSTANCE: composition has, mas. p.: wood chips 100; sodium water glass (as measured dry glass matter 40-60 of water content) 80-120; hardening agent - sodium hexafluorosilicate, di-(2-benzthiazolyl)-disulfide or its salt with toluenesulfoacid 1.2-4.2 and polyalkyl-(aryl)-alkoxysilane of the formula (I) or (II) given in description 0.6-2.0. EFFECT: enhanced quality of composition. 3 tbl

Description

 The invention relates to the production of compositions used for the manufacture of building boards operating in conditions of increased fire hazard.

Known composition, including, by weight. including phenol-formaldehyde resin 80.0-95.0; alkali metal hydride 1.0-5.0 and water 0.8-1.6, in which to increase the physicomechanical properties of particle boards, water glass (3.0-12.0) and aluminum oxide ( 0.2-0.8) [1]
However, wood-particle boards obtained from such adhesive compositions with improved physical and mechanical characteristics have reduced water and fire resistance.

Closest to the proposed technical essence is a composition for chipboards, containing, by weight wood chips 100; liquid Na-glass: dry matter of glass 15-60; 30-120 contained water and hardener sodium hexafluorosilicate 1.05-4.2 [2]
However, particle boards obtained from this composition have insufficiently high strength properties.

 The aim of the invention is to increase the strength properties of particle boards.

RSiO

(OR′)

, (I) где х=0-3,0; n=1-8;
R арил, алкил С₁-С₉, R_'=-CH₃; -C₂H₅, -C₃H₇, -C₄H₉, или формулы II
R₁O

Si

O

R₁ (II), где n=1-8; R и R_' указаны выше R_" имеют указанные значения для R, причем R, R_" могут быть одинаковые или различны, а в качестве отвердителя состав содержит гексафторсиликат натрия, ди(2-бензотиазолил)ди-сульфид или его сель с толуолсульфокислотой.This goal is achieved by the fact that the composition for chipboards, including these components in the indicated amounts, additionally contains 0.6-2.0 wt.h. polyalkyl (aryl) alkoxysiloxane of the formula I

RSiO

(OR ′)

, (I) where x = 0-3.0; n is 1-8;
R aryl, alkyl C ₁ -C ₉ , R _' = —CH ₃ ; —C ₂ H ₅ , —C ₃ H ₇ , —C ₄ H ₉ , or formula II
R ₁ O

Si

O

R ₁ (II), where n = 1-8; R and R _' above R _" have the indicated meanings for R, and R, R _" may be the same or different, and as a hardener, the composition contains sodium hexafluorosilicate, di (2-benzothiazolyl) di-sulfide or its silane with toluenesulfonic acid.

 As a wood filler, waste from sawmilling, plywood, furniture, woodworking industries, firewood, wood chips, shavings, shelled, planed, veneer, etc. can be used.

As a binder, an aqueous solution of liquid sodium glass according to GOST 13078-81 with a silicate module of 3.2, a density of 1.41 g / cm ³ , with a basic substance content (dry residue) of 33.2 wt.

As a liquid glass hardener, sodium hexafluorosilicate (Na ₂ SiF ₆ according to TU 6-09-1461-76) or altax (TU 6-09-107-78) (or altax salt with toluenesulfonic acid, obtained at a component ratio of 1: 1 (in moles).

C-S-S-C

Соль альтакса с толуолсульфокислотой -3-толуолсульфо-ди-(2-бензтиазолил)ди- сульфид

C-S-S-C

, получаемый при взаимодействии ди(2-бензтиазолил)дисульфида с толуолсульфокислотой при соотношении 1:1 (в молях) по следующей методике.Altax-di (2-benzthiazolyl) disulfide

CSSC

Altax salt with toluenesulfonic acid -3-toluenesulfo-di- (2-benzthiazolyl) disulfide

CSSC

obtained by the interaction of di (2-benzthiazolyl) disulfide with toluenesulfonic acid at a ratio of 1: 1 (in moles) according to the following procedure.

161.3 g (0.5 mol) of di (2-benzthiazolyl) disulfide, 50 g of water are charged into a reactor equipped with a stirrer, dropping funnel, thermometer, reflux condenser and a solution of 86.1 g (0.5 mole) toluenesulfonic acid in 200 g of water to obtain 50% by weight of the solution. The reaction temperature is regulated at a level of 20 + 30 ^about With dropping speed. The mixture is then stirred for 1 h at this temperature and evacuated at 1 mm Hg. and a temperature of 70 ^about With water removed.

 As alkoxysilanes and polyalkoxysiloxanes used compounds of the claimed formulas obtained by esterification of the corresponding alkyl (aryl) trichlorosilanes, dialkyl or alkyl, aryl or diaryl chlorosilanes or bottoms of the rectification column with their lower (methyl, ethyl, propyl, butyl) alcohols of various concentrations ( from 100 to 80% by volume).

 Of the claimed series of compounds in industry, the products of the esterification of phenyltrichlorosilane with ethyl alcohol (various concentrations) under the name modifier 113-63 (TU 6-02-995-75) and modifier 113-65 (TU 6-02-995-75 )

 The physicochemical constants of the used alkoxysilanes and polyalkoxysiloxanes are given in Table 1.

Using the proposed composition allows to increase the strength properties of products due to the occurrence of a number of chemical reactions between water glass, modifier and wood filler according to the scheme
≡ Si-ONa + Na ₂ SiF ₆ _ → ≡ Si-OH + 6NaF +.

≡ Si-O-Si ≡
(2)
≡ Si-OH+R′O-Si ≡

≡ Si-O-Si ≡
(3)
≡ Si-OR′+HO-

≡ Si-O-

(4) Используемые алкоксисиланы и алкоксисилоксаны, вступая в химическую реакцию с выделившейся кремневой кислотой (схема 1) или продуктом ее конденсации (схема 2), по реакции (3) или с древесным наполнителем по реакции (4), увеличивают как расстояние между формирующимися узлами пространственной сетки (т. е. пластифицируют межузловые сшивки), так и обеспечивают химическую связь на наполнитель, что в конечном счете, снижает внутренние напряжения, возникающие в системе при отверждении жидкого стекла (особенно при использовании упругого целлюлозосодержащего наполнителя), и способствует повышению прочностных характеристик готовых изделий.(one)
≡ Si-OH + HO-Si ≡

≡ Si-O-Si ≡
(2)
≡ Si-OH + R′O-Si ≡

≡ Si-O-Si ≡
(3)
≡ Si-OR ′ + HO-

≡ Si-O-

(4) Used alkoxysilanes and alkoxysiloxanes, entering into a chemical reaction with the liberated silicic acid (Scheme 1) or its condensation product (Scheme 2), by reaction (3) or with a wood filler by reaction (4), increase as the distance between the forming nodes spatial network (i.e., plasticizing the interstitial crosslinking), and provide a chemical bond to the filler, which ultimately reduces the internal stresses that occur in the system when curing liquid glass (especially when using elastic cellulose containing filler), and helps to increase the strength characteristics of finished products.

In the table. 1 shows a number of compounds illustrating examples of the claimed invention:
Products 1-3 characterize the limiting and average values of the claimed series in terms of x and n. (It is not practical to use products with n> 8 due to the high viscosity and limited compatibility with liquid glass);
Products 2, 4, 5, 6 are representatives of compounds characterized by the different nature of the alkoxy radical;
products 2, 7, 8 are representatives of the claimed series of compounds that differ in the nature of the radical at the silicon atom;
product 9 is a representative of ethanol-treated (96% concentration by volume) bottoms of the phenyltrichlorosilane rectification column;
products 10-16 are representatives of difunctional alkoxy compounds of the claimed series, differing in molecular weight (or degree of polycondensation n), type of radical at the silicon atom, nature of the alkoxy group.

 It is not practical to use linear alkoxysiloxanes with n> 8 because of their limited compatibility with liquid glass and a decrease in the strength properties of the material.

As the bottom residue of the phenyltrichlorosilane rectification column, the product was used with the following indicators: appearance is a dark, mobile liquid smoking in air without mechanical impurities and gels
n $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = 1.5763,
d $\genfrac{}{}{0ex}{}{\text{20}}{\text{4}}$ = 1.1063, kinematic viscosity at 20 C ^of 12 cSt, Cl content ^- 20.2 wt ion.

For the preparation of samples of wood-particle boards used coniferous wood chips fraction 10/5 with a moisture content of 4 wt. The estimated density of the plate is 700 kg / m ³ . Single-layer plates with a thickness of 16 mm and a plan size of 40x40 cm were made.

 In all cases, a binder is preliminarily prepared by thoroughly homogenizing the prescription amount of marketable liquid glass, hardener and modifying additive (alkoxysiloxane) for 5 minutes. Then, the prepared binder is added to the calculated amount of wood particles in a laboratory mixer with stirring, and the mixture is homogenized for 10 minutes.

From the chip sized package weight is formed, it is carried out degassing and hot pressing is carried out at ¹⁰⁰ ° C, specific pressure of 4.0 MPa for 2 hours. Examples of specific implementation are presented in Table 2.

 Test samples of plates according to the indicators given in table 3, carried out 24 hours after manufacture. Example 1 in the tables corresponds to the composition of the prototype.

Claims (1)

 COMPOSITION FOR WOOD AND PARTICLE BOARDS, including, parts by weight Wood shavings 100
Liquid Na-Glass
dry matter of glass 40 60
the water it contains 80 120
Hardener 1.2 4.2
characterized in that, in order to increase the strength properties of particle boards, the composition additionally contains 0.6 to 2.0 wt.h. polyalkyl (aryl) alkoxysiloxane of the general formula

where x 0 3;
n 1 8;
R aryl, C ₁ C ₉ alkyl;
R ′ = CH ₃ , C ₂ H ₅ , C ₃ H ₇ , C ₄ H ₉ ,
or general formula
R′O (RR ″ SiO) _n R ′,
where n, R and R ′ have the indicated meanings;
wherein R and R ′ ′ may be the same or different,
and as a hardener, the composition contains sodium hexafluorosilicate, di (2-benzthiazolyl) di-sulfide or its salt with toluenesulfonic acid.

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