JPS62131053A - Flame-retardant phenolic resin foam - Google Patents

Abstract

PURPOSE:To provide a phenolic resin foam having high flame retardance, excellent processability, physical properties, etc. and suitable for use as a ceiling material, a heat insulating material, etc., containing a phosphorus compd. and aluminum salt of a strong acid in combination as flame retarders. CONSTITUTION:A phosphorus compd. (e.g., ammonium phosphate or phosphoric acid) and aluminum salt of a strong acid having pKa<=2.5 (e.g., aluminum sulfate or aluminum chloride) are added to a phenolic resin. Further, additives such as a blowing agent, a foam stabilizer, a curing catalyst, etc. are added thereto and the mixture is expanded by heating to obtain the desired flame-retardant phenolic resin foam. Under high-temperature conditions, the phosphorus compd. is self-condensed to form water, whereby heat generation during combustion is inhibited. At the same time, the carbonization of the resin foam proceeds and a high flame retardance imparting effect can be exhibited by the synergism of the carbonization of the foam and the carbonization promoting effect of the aluminum salt of the strong acid.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a 7-element foam (resin foam) that has particularly high flame retardancy, and is used for construction panels, boards, etc. such as ceiling materials and wall materials. It is useful as a highly flame-retardant heat-insulating building material such as.

(Prior art) Phenolic resin foam itself is highly flame retardant, but when used alone, it is not suitable for applications that require high flame retardancy, such as Class 2 flame retardancy and Class 2 outdoor fire retardancy as stipulated by the Building Standards Act. It is extremely difficult to pass the exam.

Therefore, efforts have been made to improve flame retardancy by adding various organic and non-synthetic flame retardants.

For example, aluminum hydroxide, halogen compounds, heptimony compounds (Jin Nishizawa, Flame Retardant of Polymers, Taiseisha 19
79), silicon compounds, phosphorus compounds, boron compounds (Japanese Patent Application Laid-Open No. 60-81244), etc., have been studied, but they have not shown sufficient effects.

In other words, when manufacturing phenolic resin foam, if we tried to improve the flame retardance by using a conventionally used general flame retardant in order to pass the flame retardant and fire protection test, it would be difficult to make it 7 ohm. Or, even if the resistance is 7 ohm, it is often impossible to obtain any properties as a heat insulating material (for example, 7 ohm strength, thermal conductivity, etc.).

However, since the phenolic resin foam itself has high flame retardancy, inorganic flame retardants are considered to be more effective than organic flame retardants. We have focused on the fact that the strong dehydration effect of phosphorus compounds during combustion accelerates the carbonization of phenolic resin foams, and have investigated flame retardants with a focus on phosphorus compounds. Among them, we found that phosphoric acid is an excellent flame retardant in terms of both flame retardancy and processability.

However, although phosphorus compounds are effective in improving flame retardancy, they are limited by 7 ohm processability and physical properties, and are limited to a maximum of 50 parts by weight. Furthermore, it has been found that a more effective flame retardant is required in order to achieve high flame retardancy.

(Problems to be Solved by the Invention) An object of the present invention is to provide a phenolic resin foam that has extremely high flame retardancy and is also excellent in processability of 7 ohms, physical properties, etc.

(Means for Solving the Problems) The present invention relates to a flame-retardant phenolic resin foam containing a phosphorus compound and 1) an aluminum salt of a strong acid with Kll≦2.5.

The phenol resin used in the present invention is obtained by reacting phenols and aldehydes in the presence of a conventional catalyst, and any of the resol type, pentric ether type, and novolak type can be used for heavy duty. . Examples of phenols include phenol, cresol, alkyl 7-ethyl, bisphenol, etc., and examples of aldehydes include formaldehyde, 7cetaldehyde, furfural, etc. Catalysts include sodium hydroxide, calcium hydroxide, barium hydroxide, zinc acetate,
Examples include hydrochloric acid. Additives such as a foaming agent, foam stabilizer JIIq, flame retardant, and curing catalyst are mixed with this phenolic resin to obtain a foamed molded product. As blowing agents, hydrocarbons such as H oil ether and n-pentane, and halogenated hydrocarbons such as methylene chloride and trichlorofluoroethane are generally used, but powders that generate carbonate and nitrogen are generally used. It is also possible to use foaming agents. Nonionic, anionic, and cationic foam stabilizers can all be used, but among nonionic foam stabilizers, silicone foam stabilizers are preferably used. As the curing catalyst, mineral acids, aromatic sulfonic acids, etc. are used.

The flame retardants used in the present invention are phosphorus compounds as well as aluminum salts of strong acids. As phosphorus compounds, phosphoric acid,
Phosphorous acid, hypophosphorous acid, birophosphoric acid, tripolyphosphoric acid,
Examples include condensed phosphoric acids such as polyphosphoric acid, salts such as ammonium phosphate and ammonium polyphosphate, organic phosphoric acids such as phenylphosphonic acid and phenylphosphinic acid, and acidic phosphoric acid esters. C) may be used in combination with tm or two or more thereof. The amount added is phenolic resin 1
It is preferable to use 1 part by weight of 5 to 75 mff, preferably 20 to 50 parts by weight per 1 part of 00 mff.

As the aluminum salt of a strong acid with pKa≦2゜5 used in combination with a phosphorus compound, for example, aluminum chloride '7A
5 (n Examples include aluminum halide, aluminum sulfate, and aluminum phosphate.

An aluminum salt of an acid with a pKa of more than 2.5 has extremely weak action as a Lewis acid and loses its flame retardant effect. The amount added is 1 part per 100 parts by weight of phenolic resin.
~40 parts by weight, preferably 3 to 20 parts by weight.

In the present invention, flame retardants other than those mentioned above, such as general flame retardants such as aluminum hydroxide, halogen compounds, antimony compounds, and boron compounds, may be used simultaneously.

In the present invention, the flame retardant may be added to any of the phenol (fat, foaming agent, and curing agent).

The 72/-l resin foam of the present invention can be obtained by a conventional method except for using the above-mentioned flame retardant, that is, by blending the above-mentioned components to prepare a stock solution for phenolic resin foam, and A foam of 7 ohm can be obtained by pouring it into a mold or the like and heating it to room temperature to 200''C.

(Effects of the Invention) Originally, phenolic resin foam itself has its own characteristics due to the following reasons. Highly flammable. When heated, the phenolic resin foam is gradually oxidized at 200° C. or higher to form carbonized WI (amorphous carbon phase). This layer has combustion inhibiting properties,
Prevents the spread of fire inside. At higher temperatures, this amorphous phase transforms into a graphite phase, making it more difficult to burn.

Also in the present invention, the phosphorus compound self-condenses at high temperature to generate water and suppress heat generation during combustion, while at the same time promoting carbonization of the phenolic resin foam as a dehydrating agent.

Furthermore, when aluminum salts such as aluminum sulfate, aluminum chloride, and aluminum phosphate are used together in the present invention, the latent heat of vaporization due to crystallization water suppresses the heat generation during combustion of the phenolic resin foam, and at high temperatures, active oxygen is released as a Lewis acid. , extracts active hydroxyl groups and promotes carbonization of the 7 er/- ole fat foam, and the synergistic effect when used in combination is extremely large.

(Example) The present invention will be described below with reference to Examples and Comparative Examples. In addition, parts indicate parts by weight.

Examples 1 to 6 Formaldehyde 1,
Mixed in a ratio of 8IIIol, 3% by weight relative to phenol
A resol type 7-el resin having a viscosity of 6000 cps was obtained by a conventional synthesis method using sodium hydroxide as a catalyst. This liquid phenol O (100 parts fat, 15 parts trichlorotrifluoroethane, silicone MW foam cutting 5H-19
3 (made by Toshi Silicone) 1 part, the compound listed in Table 1 as a flame retardant was added in the proportion listed in the table, and 65% was added as a hardening agent.
Mix and stir 20 parts of 3% phenol sulfonic acid aqueous solution,
The mixture was poured into a 00X 300X 25 (+n111) mold and heated in an atmosphere of 70°C for 15 minutes to obtain a phenol resin foam.

Regarding flame retardancy, calorific value was measured by differential scanning calorimetry (DSC), and thermal balance analysis (TGA) was conducted at 500°C.
Weight reduction up to 72/ of 200
- The resin foam sample is heated from the back side with a burner.
Evaluation was made from the back side temperature in a horizontal flame retardant test heated to 150°C and the 7 ohm state after combustion. The results are shown in Table 1.

Comparative Examples 1 to 7 Phenol resin foams were obtained in the same manner as in Examples, except that the flame retardants shown in Table 2 were used. The flame retardancy of the obtained phenolic resin foam was evaluated in the same manner as in the examples.

All six examples showed high flame retardancy, and Comparative Example 3 was one in which up to 50 parts of phosphoric acid, which is known for its high flame retardant effect, was added. It is shown that all have higher flame retardancy than Comparative Example 3.

7 ether tM III obtained by this flame retardant treatment
The foam should not be penetrated by a flame of 1150°C (Bunsen burner flame) for more than 30 minutes, and the back side temperature should not exceed 160°C.
I was able to reduce it to a phrase.

(that's all)

Claims (1)

[Claims] (1) A flame-retardant phenolic resin foam containing a phosphorus compound and an aluminum salt of a strong acid with pKa≦2.5.