SU1182014A1 - Method of water-repellency treatment of heat-insulating materials - Google Patents

Description

The invention relates to the manufacture of insulating materials based on dispersed fibers, in particular to the manufacture of materials with hydrophobic properties.

The purpose of the invention is to improve the conditions of hydrophobization, preservation of the original physico-mechanical properties of the material and increase heat resistance.

Treatment with methyltrimethoxysilane vapor (MTMS), dimethyldimethoxysilane (DMDMS) or an arbitrary mixture is most conveniently carried out at room temperature, since these modifiers are easily volatile and the reaction proceeds for 3-16 hours, depending on the nature of the material, but when heated, this process runs faster.

The effectiveness of each of the two silanes is the same; therefore, their ratio in the mixture can be arbitrary, i.e. correspond to the following ratio, ob.h .: MTMS 0.1-99.9;

DMDMS 99.9-0.1.

G'pdrofobizatsiya thermal insulating fibrous materials in laboratory conditions produced as follows.

A sample of the material was placed in the reactor and treated with water vapor> with or without heating, for which an open container with water was placed inside the reactor.

The amount of adsorbed moisture was determined by the weight gain of the sample.

Next, in the same reactor was injected a pair of MTMS, DMDMS, or their mixture, for which an open container with modificato, ·

rum or their mixtures were placed in a reactor.

The reaction is carried out with or without heating to a temperature not exceeding the boiling temperature of individual modifiers and mixtures thereof (T _ILC MTMS 102-104 ° C, DMDMS _bp 82-84 ° C).

The hydrophobicity of the obtained product was estimated by the amount of adsorption of water vapor at P / P _d = 1 (saturation pressure) and moisture absorption of the samples when immersed in water and kept in it for 24 hours.

The presence of a chemically grafted layer of water-repellent agent was judged by the weight gain of the sample after heat treatment for organic materials at 300 ° С, for inorganic materials at 450 ° С for- ^! 8 hours

14 2

Determination of tensile strength (breaking load) was determined <

in accordance with GOST 15902.3-79.

The conditions for carrying out specific processes in the test results of the obtained samples are given in the table ^

These tables show that the activation of water vapor leads to an increase in the weight of the grafted water-repellent agent. For organic materials, this can be seen from a comparison of sample 10, obtained without prior treatment with water vapor (5% is the normal moisture content of the material), with samples 1–9.

Hydrophobization by this method leads to a weighting of the material by 2-3% and allows to reduce water absorption by more than 1000 times compared to the original untreated sample - (11) and 300 times compared to the sample that did not pass the pre-activation (10). The amount of moisture absorption practically does not change after heat treatment for 8 hours at 300 ° C (heat resistance of the starting material).

For inorganic materials (TZMK), the hydrophobization according to this method allows to obtain a hydrophobic coating resistant at 450 ° C, slightly weighting material (2%), to reduce moisture absorption by more than 600 times compared to the original sample (cf. 17 with 13-15) and more than 100 times compared to the non-activated sample (cf. 17 and 16). From a comparison of sample 13 with samples 14-15, it can be seen that an increase in moisture content above 20% does not lead to a significant change in property. The sample treated with the prototype (18) retains its hydrophobic properties up to 400 ° C, and as can be seen from the table after treatment for 8 hours at 450 C, it almost completely loses them. Processed prototype sample of organic material (12) deteriorated the strength properties of 9-10 times, lost elasticity, became brittle.

Thus, the proposed method allows you to hydrophobize both inorganic and organic materials without the use of toxic activators, while ensuring the safety of the physicomechanical properties of the organic material and increasing the heat resistance of the hydrophobic layer.

W 182014 4

coating on an inorganic material. The proposed method can be

rial. In addition, the advantage applied to the hydrophobization of the proposed method is possible organic and inorganic materials.

it can be carried out without heating materials with a porous structure, and also

material. 5 for the hydrophobization of dispersed mothers, al.

Sample Material Hydrophobic conditions Properties gidrofobizirovannyh samples Humidity, 2 Modifier The ratio of components Adsorption of water vapor at p / p ₅ = 1, mmol / g Moisture absorption, 2 one ATM-15 sixteen MTMS 100 0.34 0.65 2 ATM-15 15 DMDS 100 0.37 0.7 3 ATM-15 16.2 MTMS 50 0.36 0.68 DMDS 50 four ATM-15 14 MTMS 0.1 0.38 0.71 DMDS 99.1 five ATM-15 15 MTMS 99.1 0.36 0,69 DMDS 0.1 6 ATM-16 20.5 MTMS 100 0.42 0.8 7 ATM-19 13.5 MTMS 100. 0.33 0.62 eight Arimts-T 14 MTMS 100 0.35 0.65, 9 TerloP 12 mgms 100 0.33 0.63 ten . ATM-15 five MTMS 100 0.42 14 1.1 ATM-15 6 - - - 900 12 ATM-15 Prototype - - 13 TZMK 26 MTMS 100 0.52 1.1 14 TZMK 20' MTMS 50 0.56 1.2 - DMDS 50 • 15 , TZMK ten DMDS 100 0.54 1.14 sixteen TZMK 2 mgms 100 0.72 28 17 TZMK - - - 2.46 800 18 TZMK (prototype) ‘By 'prototype 0.56 1.2

VO About

I 'Oh ί: · / In

VO v- O O ·.: ·

n>: · '· _; ; H:

-

 · O n; ΟΒ,

O ' ^: Β ^; · ο ν ^: Ί ') 1 ίΟ O /! VOV VO, · About in; in..

• ΒΒ.ΟΒΒΟΒ! -at

Claims (1)

METHOD OF HYDROPHOBIZATION OF HEAT-INSULATING MATERIALS based on dispersed fibers, including activation of the surface of the material and treatment with silane vapors, characterized in that, in order to improve the conditions of hydrophobization, preserve the original physicomechanical properties of the material and increase heat resistance, hydroactivation is carried out to a moisture content of 3-25% , and methyltrimethoxysilane or dimethyldimethoxysilane or their mixture is used as silane vapor. 3 ί 11