JPH02202968A - Intumescent coating - Google Patents

Abstract

PURPOSE:To prepare an intumescent coating capable of forming an incombustible transparent film by mixing a soln. contg. a specific resin precondensate and a polysaccharide with a soln. contg. a precondensate of a carbamic acid- modified urea resin and a silicon resin. CONSTITUTION:At least one compd. selected from the group consisting of ethanolamine and urea derivs. is reacted with formaldehyde in an aq. soln. to give a reaction product comprising a precondensate or mixture thereof selected from the group consisting of a urea resin precondensate, a melamine resin precondensate, a urea-melamine resin precondensate and mixtures thereof. Said reaction product is then mixed with at least one polysaccharide as a carbonizing component to give a soln. (A). Separately, formaldehyde, a carbamate ester and at least one polysaccharide are mixed, reacted, mixed with at least one compd. selected from the group consisting of urea and its derivs., and reacted to give a precondensate of a carbamic acid-modified urea rein, which is then mixed with a silicone resin to give a soln. (B). Solns. A and B are mixed to give the desired intumescent coating.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a fireproofing paint, and more particularly to a foamable fireproofing paint capable of forming a nonflammable transparent film.

``Prior art'' The foaming component is a substance that generates a large amount of ammonia or nitrogen when heated, such as melamine, dicyandiamide, urea, guanidine, organic amine, inorganic ammonium salt, etc., and the carbonization material is polysaccharide, monosaccharide, pentaerythritol, etc. Foaming fireproofing paints that use phosphorous compounds as a carbonized layer formation aid and dehydrating agent have been known for a long time.

Since the materials for the above-mentioned foamable fireproof paints are all soluble in water, they have the disadvantage that the water resistance of the paint film is poor.

In order to improve such drawbacks, a methylolated product or an initial condensate is produced by the reaction of the foaming component compound with medium luminaldehyde, and then a carbonized component such as sugars and polyhydric alcohols and a phosphorus compound are added and condensed into water. Many proposals have been made for creating insoluble foamable materials and dispersing them in liquids or for foaming fire prevention paints.

These foaming fire prevention paints with improved water resistance are generally cloudy and opaque because each component is dispersed in the liquid.
It is not suitable when it is desired to make use of the background of the surface to be painted, or when a coloring pigment is added, the hue becomes cloudy and it is difficult to color it like a normal colored paint. Therefore, several proposals have been made regarding foamable fireproofing paints with transparent coating films.

For example, ``a fire-retardant paint whose main components are a foaming component made by blending a resin obtained from a guanidine compound and formaldehyde, pentaerythritol, and phosphoric acid, and an amino resin'' is described in JP-A-49-126775. has been done.

Foaming fireproofing paints made only of organic substances as mentioned above are classified as J.
Although it complies with the flame retardant materials specified by the IS regulations and can withstand high temperatures below 1000°C, it is not effective at high temperatures above 51000°C, especially above 1500°C as the foamed film will burn.

In order to withstand high temperatures of too many degrees Celsius or higher, for example, as in the invention described in JP-A-51-80336,
Since the main ingredients are sodium silicate and inorganic fine powder, it must form an enamel foam film when heated.

However, since silicates are water-soluble, the coating film does not have water resistance.
Although 0 parts by weight is added to impart water resistance, the resulting coating film is opaque.

[Problem to be solved] In order to improve water resistance, conventional foaming fireproofing paints have made their components insoluble in water, making it impossible to obtain a transparent film and causing turbidity in the colored hue, which limits heat resistance. In addition, the problem that only opaque films can be obtained with those that are immersed in heat resistance is an obstacle to the widespread practical application of foamable fireproofing paints.

The present invention solves these problems and provides a foamable fireproofing paint that forms a foamed layer that can withstand high temperatures of 1500° C. or higher and provides a transparent, water-resistant film.

"Means for Solving the Problem" The foamable fireproofing paint of the present invention has a foaming component as its main component (A
) and (B), the main components of which are film-forming components.

Liquid (A) is produced by reacting one or more compounds selected from formaldehyde, ethanolamine, urea, and urea derivatives to form an initial condensate, which is then combined with IN selected from polysaccharides or two or more compounds selected from polysaccharides. prepared by adding a compound.

The liquid (B) is made by reacting one or more compounds selected from formaldehyde, carbamate esters, and one or more compounds selected from polysaccharides to form an initial condensate, and then melamine. The mixture is added and reacted to produce an initial condensate of carbamic acid-modified melamine urea resin, which is then prepared by adding a silicone resin.

The carbamate ester used in the present invention is a group of compounds generally called urethanes, including methyl carbamate,
Ethyl carbamate, (urethane in a narrow sense), butyl carbamate, etc. can be used.

Suitable urea derivatives used as the foaming component are compounds having an amino group that reacts with formaldehyde, such as guanidine, dicyandiamide (cyanoguanidine), and melamine.

As the polysaccharide used as the carbonization component, water-soluble compounds such as glucose, monosaccharide, and sucrose are suitable.

A water-based emulsion is suitable for silicone resin.

"Function" The foamable fireproofing paint of the present invention contains 35 to 60% silicone resin.
When heated and foamed, the silicon in the silicone resin forms a ceramic-like film, forming a completely non-flammable carbonized layer that does not change in quality even when exposed to high-temperature flames of 1500℃ or higher, and also contains silicone resin. A transparent film is obtained.

The present invention will be explained below with reference to Examples.

"Example 1" 39 parts by weight of melamine was added to 100 parts by weight of a 37% formaldehyde aqueous solution to make I)H8,O~9.0 by adding ethanolamine, and heated under reflux at 70 to 80°C with stirring to obtain a transparent Make a solution. Boric acid and ammonium phosphate are added to this solution to make a buffer solution and adjust the pH to 7.5-8.
5, and add and dissolve 10 parts by weight of starch to prepare solution (A).

On the other hand, 30 parts by weight of urethane (ethyl carbamate) and 10 parts by weight of crushed sucrose were added to 37% formaldehyde aqueous solution 'ti, ioo, stirred and heated under reflux at 70-80°C to obtain a transparent solution, and then 30 parts by weight of melamine was added. 1 part and heated under reflux at 70-80°C with stirring to obtain a clear solution.

220 parts by weight of an aqueous silicone resin emulsion having a solid content of 40% was added to this solution to prepare liquid (B).

The above liquids (A) and (B) were mixed at a ratio of 1:1 to obtain a paint solution.

This paint solution was applied to a plywood board with a thickness of 5111111 to form a transparent coating film about 200μ thick, and when the flame of a propane/butane torch was directly applied to the coating film, it carbonized to a thickness of about 2cm in about 20 seconds. The film bulges, and even after one hour has passed, the temperature on the back side of the plywood remains at about 180 to 200 degrees Celsius.
Complete nonflammability was confirmed.

"Example 2" 3 made alkaline by adding 5 parts by weight of ethanolamine
37 parts by weight of urea is added to 100 parts by weight of a 7% formaldehyde aqueous solution, and heated under reflux to 80 to 90°C while stirring.

After about 60 minutes, heating was stopped, the mixture was cooled to room temperature, boric acid and ammonium phosphate were added to adjust the temperature to 88.0 to 8.5 (I), and 15 parts by weight of glucose was added and dissolved (A).
A liquid was prepared.

On the other hand, 25 parts by weight of methyl carbamate (urethane) and 10 parts by weight of starch are added and heated under reflux at 75 to 85°C with stirring to obtain a transparent solution. This solution has a solid content of 40
4% silicone resin 240wt 1 part aqueous emulsion
0 parts of heavy equipment were added and stirred to prepare solution (B).

The above liquids (A) and (B) were mixed at a ratio of 1:1 to obtain a fire-retardant paint solution.

This paint solution is applied to the surface of vinyl cloth and dried to form a fire-retardant paint film approximately 150μ thick.The vinyl cloth is pasted onto plywood using water-based cloth glue, and after drying, a propane/butane torch is applied. When directly exposed to flame, approx.
A carbonized layer with a thickness of about 1 CI11 rose in 5 seconds, the vinyl cloth did not burst into flames even after about 1 hour, and the surface temperature of the back side of the plywood was 170 to 190°C.

"Example 3" 37 with 17.5 to 8.5 by adding ethanolamine
% formaldehyde in water tLxo.

Add 50 parts by weight of dicyandiamide to the parts by weight and heat under reflux at 70 to 80°C while stirring to obtain a transparent solution, then add boric acid and ammonium phosphate to pH 7.5 to 8.
．． 0 and added sucrose to parts by weight to prepare solution (A).

On the other hand, 25 parts by weight of butyl carbamate (urethane) was added to 100 parts by weight of a 37% formaldehyde aqueous solution, and the mixture was heated under reflux at 70 to 80°C with stirring to obtain a transparent solution.

Next, add 40 parts by weight of urea and reduce to 75 to 85 parts by weight while stirring.
A clear aqueous solution was obtained by heating to reflux at °C. To this solution was added 300 parts by weight of aqueous emulzidine, a silicone resin with a solid content of 40%, to prepare liquid (B).

The foamable fireproofing paint of the present invention was prepared by mixing the above (A'')'/fL and (B) solution in a ratio of 1:1.

Apply this fire protection paint to a 5sa+ thick cardboard paper.
It was dried to form a coating film with a thickness of about 250 microns. When the flame of a propane/butane torch was directly applied to this painted surface, a carbonized layer with a thickness of about 2.5 cm was formed in about 30 seconds, and although the flame was continued to be applied for several hours, the surface temperature of the back side of the cardboard remained The temperature did not rise above 180-200°C, confirming complete nonflammability.

Claims (2)

[Claims] (1) A urea resin initial condensate, a melamine resin initial condensate, or a urea-melamine initial condensate obtained by reacting formaldehyde, ethanolamine, and one or more selected from urea or urea derivatives, and a polysaccharide. A solution (A) containing one or more selected compounds, one or more compounds selected from formaldehyde and carbamate esters, and one or two selected from urea or urea derivatives. One or two selected from the carbamic acid-modified urea resin initial condensate obtained by reacting the above compounds with silicone resins and polysaccharides.
A foamable fire-retardant paint formed by mixing a solution (B) containing at least one compound. (2) A urea resin initial condensate, a melamine resin initial condensate, or a urea-melamine resin initial condensate obtained by reacting one or more compounds selected from formaldehyde, ethanolamine, and urea or urea derivatives in an aqueous solution. A solution (A) is prepared by producing a species or a mixture of two or more species, and then adding one or more compounds selected from polysaccharides as a carbonization component, and separately from formaldehyde, a carbamate ester, and a polysaccharide. Mixing and reacting one or more selected saccharides, then adding and reacting one or more compounds selected from urea or urea derivatives to produce an initial condensate of a carbamic acid-modified urea resin; Add and mix silicone resin to form a solution (B
2. The method for producing a foamable fireproofing paint according to claim 1, which comprises preparing a solution (A) and a solution (B).