RU2526980C1 - Fire-protecting composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: fire-protecting composition for covering glass-reinforced plastics includes perchlorovinyl resin, as organic solvent, mixture of butylacetate and acetone in ratio 1:1, as expansion agent, phosphorus-boron-nitrogen-containing oligomer, preliminarily obtained as a result of interaction of methylphosphite borate, epoxy resin ED-20 and aniline in weight ratio 2.5:1:2.5.

EFFECT: invention makes it possible to provide high fire protection for glass-reinforced plastic coatings.

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Description

The invention relates to the field of production of flame retardant coatings based on a polymer binder and may find application in shipbuilding, military industry, and transport.

Known fire retardant composition containing perchlorovinyl resin, solvent, a condensation product of formaldehyde, dicyandiamide, sorbitol, oxalic acid. (Pat. 2185408 Russia, C09D 127/24, C09D 5/18; Published on July 20, 2002).

This fire-retardant composition has high foaming and heat-insulating properties, but it has a more complex composition, the production technology is multi-stage and requires the maintenance of strictly defined temperature conditions, long exposure time after application is required.

Known composition intended for protective and decorative coatings of wood. The composition contains perchlorovinyl resin PSX-LS, the filler is titanium dioxide, pigment and solvent. As a solvent, it contains ethyl acetate or dichloromethylene and ethyl acetate, or dichloromethylene and acetone (Pat. 2265633 Russia, C09D 127/06, C08F 14/06, C08F 114/06; Publ. 10.12.05).

However, this composition is intended to protect wood materials.

Closest to the invention (prototype) in technical essence is fire retardant enamel. The composition contains a chlorinated derivative of polyvinyl chloride (perchlorovinyl resin), an organosilicon resin, a pentaphthalic resin, an epoxy resin, a pigment, a solvent, low-molecular and polymeric phosphorus-containing compounds, oxidized graphite as an intumescent additive (US Pat. 2177973/2404, Russia, C09, 0909 04, C09D 5/18, C09D 127/24; Publ. 10.01.02).

This fire retardant composition has a more complex composition and is intended for fire protection of metal and wooden structures.

Objective: obtaining a flame retardant composition based on perchlorovinyl resin for fiberglass.

The technical result is the provision of high fire protection coatings for fiberglass.

The technical result is achieved in that the flame retardant composition for coating fiberglass, including perchlorovinyl resin, an organic solvent, an intumescent additive, and it contains as a solvent a mixture of butyl acetate and acetone in a ratio of 1: 1 and as an intumescent additive is a phosphorus-boron-containing oligomer previously obtained in the result of the interaction of methylphosphite borate, epoxy resin ED-20 and aniline in a mass ratio of 2.5: 1: 2.5, in the following ratio of components, parts by weight : perchlorovinyl resin - 15.0; indicated organic solvent - 85.0; said phosphorus-boron-containing oligomer - 2.5-7.5.

CPVC brand perchlorvinyl resin (OST 6-01-37-88, amend. 1.2) is used in the production of adhesives, coatings as a polymer binder.

Butyl acetate (GOST 8981-78) is used as a solvent.

Acetone (GOST 2603-79) is used as a solvent.

As an intumescent additive, a phosphorus-borazo-containing oligomer (FEDA) is used, previously obtained as a result of the interaction of methylphosphite borate, ED-20 epoxy and aniline in a mass ratio of 2.5: 1: 2.5. Methyl phosphite borate was previously used for flame retardant modification of cellulosic materials (US Pat. RF 2254341 C1, C08B 15/05, publ. 06/20/05). To prepare the FEDA, the required amount of ED-20 epoxy and aniline are loaded into the mixer, mixed until a homogeneous mass is obtained. Then, the calculated amount of methylphosphite borate is slowly added dropwise, preventing the reaction mass from heating above 25 ° C. The synthesis is carried out with constant stirring. FEDA preparation time is 2.5-3 hours. Some physical properties of the oligomer are presented in table 1.

Table 1 Physical properties Value Relative density, g / cm ³ 1.4914-1.5478 Refractive index 1,461-1,496

The presence of phosphorus, boron and nitrogen atoms in the phosphorus-boron-containing oligomer, which are inhibitors of the combustion and oxidation processes, makes the composition based on perchlorovinyl resin fire resistant. In addition, a significant content of phosphorus and boron in the structure of the substance helps to achieve the maximum result without resorting to the use of large concentrations.

This composition allows to obtain coatings based on perchlorovinyl resin with increased fire protection. The use of 15% solutions of perchlorovinyl resin is most optimal. With increasing concentration, the viscosity of the solutions increases, which creates technological difficulties in the application of coatings and leads to a deterioration in the fire retardant properties of the coating.

The use of solutions of lower concentration leads to an increase in the volume of compositions to obtain a coating of the required thickness. A decrease in the content of FEDA leads to a decrease in fire resistance, and an increase in its content contributes to an increase in the curing time of the composition.

Fire retardant composition is prepared as follows.

Perchlorvinyl resin, together with a mixture of solvents, is loaded into the mixer and mixed until completely dissolved. Then the introduction of intumescent additives - FEDA. The total cooking time is 0.5-1 hours.

The invention is illustrated by the following example.

FEDA is introduced into a flask containing a solution of perchlorovinyl resin and the contents are mixed for 3-5 minutes until a homogeneous mass is obtained.

Get compositions 1-3, the compositions of which are shown in table 2.

The composition is a white liquid. It is well applied on the surface of fiberglass.

The various contents of the FEDA intumescent additive have been investigated. The research results are shown in table 3.

The declared limits of the FEDA are due to the fact that with an increase or decrease in the indicated dosages, the coefficient of expansion increases and, therefore, the fire protection decreases.

In order to determine the effectiveness of the developed flame retardants, coatings were tested by exposing the treated specimen to fiberglass to an open flame source. The test setup is assembled on the basis of a laboratory chemical tripod and installed in a well-ventilated room. Samples for measurements have the following dimensions: length - 50 mm, width - 50 mm, thickness - 1.8-2 mm. The thickness of the fire retardant coating is 1.0 mm. The claimed coating thickness is explained by the fact that with a decrease in the coating thickness the necessary fire retardant properties are not achieved, and an increase in the coating thickness leads to an increase in the curing time of the composition. Before measurements, the coated samples are dried at room temperature for at least two days. The sample prepared for testing is fixed vertically in a tripod. Use a universal gas burner Bunsen equipped with a nozzle with a hole diameter of 7 mm. A gas burner (using household gas), which is in a horizontal position at a distance of at least 200 mm from the sample, is ignited and adjusted so that the flame height is 150-180 mm. The flame is directed exactly to the center of the fixed fiberglass specimen. The air supply is regulated until the yellow tip of the flame disappears.

Temperature measurements are carried out by the device - S-300.3 pyrometer (GOST 28243-96 "Pyrometers. General technical requirements"). The principle of operation of the pyrometer is based on measuring the thermal radiation power of the measurement object mainly in the ranges of infrared radiation and visible light.

Using a pyrometer, a temperature change is recorded on the unheated surface of the prototype over time until the limit state of the fiberglass prototype is reached. For the limiting state of the material, the appearance of a black spot on the unheated side of the prototype was taken - loss of integrity of the material. Next, measure the height of the formed coke by changing the thickness of the sample before and after the test and calculate the coefficient of expansion.

As a result of the tests, it was found that the achieved expansion coefficient of the order of 5.55-6.47 significantly reduced the weight loss of the sample from 24.7% to 6.2-8.6%, and the time to reach the limit state of the experimental samples increases by 1.7 -2.0 times.

table 2 Component The content of components, parts by weight, in the composition one 2 3 Perchlorovinyl Resin 15.0 15.0 15.0 Organic solvent (1: 1 mixture of butyl acetate and acetone) 85.0 85.0 85.0 FEDA Intumescent 2,5 5,0 7.5

Table 3 Test Metric for composition No intumescent one 2 3 Expansion coefficient 1.55 6.0 5.55 6.47 Mass loss% 24.7 8.6 6.4 6.2 Time to reach limit state, s 29th 52 57 63 The temperature of the unheated side of the substrate at the time of the start of expansion of the coating, ° C 98.1 68,4 62.8 60,4 The temperature of the unheated side of the substrate after 25 s, ° C 126.2 81.3 79.5 78.6

A study of resistance to fire shows that the introduction of an FEDA intumescent additive into the composition contributes to the formation of a significant layer of coke, a decrease in the weight loss of the sample, and high fire resistance of the coating.

The technical and economic effect obtained from the use of this composition is that its use can significantly increase the fire resistance of fiberglass.

Claims (1)

A flame retardant composition for coating fiberglass, including perchlorovinyl resin, an organic solvent, an intumescent additive, characterized in that it contains a 1: 1 mixture of butyl acetate and acetone as an organic solvent and a phosphorus borane-containing oligomer previously obtained as a result of the interaction of borate methylphosphite, epoxy resin ED-20 and aniline in a mass ratio of 2.5: 1: 2.5, in the following ratio of components, parts by weight:
Perchlorovinyl Resin 15.0 Specified Organic Solvent 85.0 The specified phosphorus-boron-containing oligomer 2.5-7.5