JPH0473378B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a heat insulating material with excellent flame retardancy and waterproof properties. (Conventional technology) Phenol resin foam (phenol foam)
It has particularly excellent flame retardancy compared to urethane foam and styrene foam, and has other features such as heat resistance and low smoke emission. Recently, the certification of quasi-noncombustible materials has become stricter by the Ministry of Construction, and an additional test (large-scale combustion test) is required in addition to the conventional combustion test.
The conventional urethane foam and styrene foam cannot be certified as semi-flammable, and it is now expected that organic foams will only pass the test if they are phenol foam or isocyanurate foam. In addition to adding a flame retardant, these foams may also require a laminated structure with a metal surface material such as iron or aluminum, or an inorganic material such as gypsum board or calcium silicate board. However, phenol foam has higher water absorption than urethane foam or styrene foam, and absorbing water increases thermal conductivity and reduces heat insulation performance. Furthermore, when used as a heat insulating material in a cold region, dew condensation may occur depending on the conditions of use.
In addition, in the case of an insulating board, where the water vapor impermeable surface material and backing material are integrally bonded to the foam, water absorption and moisture absorption from the surface of the board can be prevented, but absorption from the cross section (edge) of the board may occur. It is considered a problem. (Problems to be Solved by the Invention) An object of the present invention is to provide a heat insulating material with excellent flame retardancy and waterproof properties. Another object of the present invention is to provide a heat insulating material having a coating film on its surface that has excellent workability and adhesive properties. (Means for Solving the Problems) The present invention relates to a noncombustible heat insulating material characterized in that a resorcinol adhesive is applied to the surface of a phenolic resin foam. The phenolic resin foam used in the present invention is one made as follows. The raw material phenolic resin is obtained by the reaction of phenols and aldehydes, and depending on the type of synthesis catalyst, resol type, benzyl ether type and novolak type can be obtained. Among these, liquid resol type and benzyl ether type are preferred. A foaming agent, a foam stabilizer, a curing catalyst, etc. are mixed with this phenolic resin to obtain a foamed molded product. Petroleum ether as a blowing agent;
Hydrocarbons such as n-pentane and halogenated hydrocarbons such as methylene chloride and trichlorotrifluoroethane are generally used, but powdered blowing agents that generate carbonized gas or nitrogen gas may also be used. As the foam stabilizer, for example, all nonionic, anionic, and cationic foam stabilizers can be used, but among the nonionic foam stabilizers, it is preferable to mainly use silicone foam stabilizers. For the curing catalyst, mineral acids and aromatic sulfonic acids are preferred for resol type and benzylic ether type, and hexamethylenetetramine and the like are generally preferred for novolac type. These components are mixed and a foam molded product is obtained using various devices such as a laminator. The density of the foam is preferably about 20 to 200 Kg/m ³ , and the denser the bubble size, the better. The resorcinol adhesive used in the present invention is preferably an aqueous solution type from the viewpoint of safety and hygiene, but is not particularly limited. Resorcinol adhesives are obtained by heating and polymerizing resorcinol and formalin using a conventional method.In addition to resorcinol, phenol,
A third component such as cresol may be copolymerized. As a curing agent, hexamethylenetetramine or the like is generally used. In addition to these components, fillers and other additives may also be mixed. The heat insulating agent of the present invention can be obtained by coating the surface of a phenolic resin foam with the above resorcinol adhesive. It is preferable to apply the coating to the entire surface of the foam, but it is also possible to apply the coating only to necessary areas, such as only the end of a board with an impermeable surface material. The coating thickness is usually about 10 to 500μ
is preferable, and it is suitable to apply it about 1 to 3 times. Application can be carried out by conventional methods such as brush, roller, spray, etc. Curing can be performed by room temperature curing or heat curing.
In the case of heat curing, a temperature in the range of about 50 to 150°C is generally preferred. The curing time is generally within several hours after application, and the shorter the time, the better the workability. The heat insulating material of the present invention is, for example, a heat insulating base material for buildings,
It can be used as interior materials and various heat insulating materials, especially in applications that require highly flame retardant and waterproof properties. (Effects of the Invention) The heat insulating material of the present invention has the following effects. (1) It is flame retardant. Resorcinol resin has a similar structure to phenolic resin, and like phenolic resin, the coating film does not burn even when exposed to a burner, and does not impede the flame retardant performance of phenolic foam. (2) Excellent waterproofness. Resorcinol resin has low water absorption, and when applied to phenol foam, a waterproof layer is formed, reducing the water absorption of the foam. (3) Good adhesion to foam. The adhesion of the resorcinol coating to the phenol foam is good, and the foam will break if peeled off. (Example) The present invention will be described below with reference to Examples and Comparative Examples. In addition, parts indicate parts by weight. Example 1 100 parts of liquid phenolic resin, 15 parts of trichlorotrifluoroethane, silicone foam stabilizer SH-193
(manufactured by Toray Silicone) and 20 parts of a 65% phenolsulfonic acid aqueous solution as a hardening agent were mixed and stirred.
The mixture was poured into a 300 x 25 mm mold and left in an atmosphere of 70°C for 10 minutes to obtain a phenol foam. 100 x 100 x 25 mm from the center of the resulting foam
Cut out a test piece, apply a room temperature curing resorcinol coating agent to the test piece, and
The water absorption was measured according to A9514-1975, and the adhesion and flammability of the coating were also measured at the same time. Results first
Shown in the table. Comparative Examples 1 to 5 Comparative Examples 1 to 5 were conducted in the same manner as in Example 1, except that various cold-curable coating materials shown in Table 1 were used. The results are shown in Table 1. As is clear from Table 1, the heat insulating material of the present invention satisfies the properties of water absorption, adhesion, and flame retardancy and is optimal. 【table】

Claims (1)

[Claims] 1. A noncombustible heat insulating material characterized by applying a resorcinol adhesive to the surface of a phenolic resin foam.