JPS5947649B2 - Method for making hard urethane foam nonflammable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a treatment method for making rigid urethane foam non-flammable, and in particular, it is intended to make flame-retardant rigid urethane foam even more non-flammable.

In general, rigid urethane foam is used in large quantities as building materials and other members because it has excellent heat insulation and sound absorption properties and is lightweight.

However, since rigid urethane foam is easily flammable, once a fire occurs, it can easily spread and cause the fire to spread. Therefore, the development of flame retardant rigid urethane foam has been in progress for a long time, and many methods have been studied. That is, a flame retardant material such as a phosphoric acid ester such as tricresyl phosphate or a halogen ester is added to a rigid urethane foam, or bromine, chlorine, phosphorus, etc. are added to a polyol molecule and polymerized to make it flame retardant. There are isocyanurate foams that are used either as raw materials or as trimerized tolylene diisocyanate through special treatment. However, if the flame-retardant rigid urethane foam obtained by the first two methods is ignited, although it may impart flame retardancy, it cannot prevent the spread of fire.

Although the latter isocyanurate foam has a superior flame retardant effect than the former, it has the disadvantage that when ignited, flames travel along its surface. As described above, in the conventional method, even if rigid urethane foam could be made flame retardant, it was not possible to make it nonflammable. Therefore, there has been a demand for a nonflammable rigid urethane foam. The present invention was discovered as a result of intensive research in response to such demands.

That is, the present invention is a method for making a rigid urethane foam nonflammable, which is characterized by applying a mixture of rubber latex and metal hydroxide to the surface of the rigid urethane foam. The gist of the present invention is to use a mixed liquid of rubber latex and metal hydroxide, and the rubber latex includes:
Either natural rubber or synthetic rubber latex may be used. The metal hydroxide is not particularly limited, but aluminum hydroxide, barium hydroxide, and the like having water of crystallization are preferred. There are no particular limitations on the blending ratio of rubber latex and metal hydroxide, but it is desirable to blend 300 parts by weight or more of metal hydroxide to 100 parts by weight of rubber latex, but less than 300 parts by weight. In this case, the nonflammability effect is weak. In the present invention, the above-mentioned liquid mixture may be applied to the surface of a rigid urethane foam at room temperature or heated, and then dried.

In this case, the rigid urethane foam may be any rigid urethane foam obtained by any method, but it is particularly desirable to use isocyanurate foam. Next, examples of the present invention will be described.

Example 1 Mix and foam the raw materials with the following composition to determine the specific gravity. An isocyanurate form of 0.031 was obtained.

A mixture of 100 parts by weight of neoprene latex and 500 parts by weight of aluminum hydroxide was applied to the surface of the above-mentioned isocyanurate foam at room temperature, and this was dried to obtain a nonflammable hard urethane foam. When this foam was brought into contact with the flame of a gas burner, no smoke or flame was emitted.

When the above-mentioned isocyanurate foam was brought into contact with a gas spanner, a flame suddenly ran across the surface and the foam was carbonized. As described above, according to the method of the present invention, (1) hard urethane foam can be made nonflammable.

(Z No smoke is generated even if flame comes into contact with it.

(3) Since the noncombustible material is coated only on the surface, it does not interfere with the properties of the hard urethane foam.

It has particularly excellent effects and is extremely useful as a building material and other uses.

Claims (1)

[Claims] 1. A method for making rigid urethane foam nonflammable, which comprises applying a mixture of rubber latex and metal hydroxide to the surface of the rigid urethane foam.