JPS5951582B2 - Manufacturing method of foaming flame retardant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for preparing an aqueous foaming flame retardant solution that provides a transparent coating.

Conventionally, water-soluble flame retardants such as ammonium phosphate, borax, boric acid, ammonium sulfamate, ammonium bromide, urea, and sodium silicate have been used as flame retardants for wood, fibers, paper, paints, etc. It is being

However, these have the disadvantage that they are hygroscopic and have poor water resistance, and that when applied to a material to be treated, the chemicals are exposed on the surface, impairing its aesthetic appearance. i Recently, in addition to these flame retardants, condensed phosphoric acid compounds have been used, and many methods of manufacturing and using them have been reported (Japanese Patent Application Laid-Open No. 48-400
No., JP-A-49-8498, JP-A-49-30356
No., Japanese Patent Publication No. 45-434 and Japanese Patent Publication No. 49-74768
(Refer to each specification).

They are condensed phosphoric acid compounds with a degree of condensation n of 20 or more that is poorly soluble or insoluble in water and insoluble in organic solvents, and cannot be mixed into plywood adhesives, kneaded into plastics or chips, or mixed into paints. It is used by means such as mixing when adding a heater to paper. However, when used by applying it to the surface of the material to be treated, there is still a drawback that the color of the chemical is exposed and the aesthetic appearance is impaired, and the range in which it can be used is limited. The present inventors conducted research on improving the properties of such condensed phosphoric acid compounds with n of 20 or more, which are sparingly soluble or insoluble in water and insoluble in organic solvents. It has been found that by making the compound water-soluble, the above-mentioned compound, which could not be applied transparently by any conventional method, can be transparently adhered to the object to be treated. The present invention is based on this knowledge, and is based on the general formula (wherein n
is a number of 20 or more, Al, A2 and A3 may be the same or different and mean H, NH4 or CONH2, provided that
100 parts by weight of a condensed phosphoric acid compound (except when Al, A2 and A3 are simultaneously H) and 20 to 3 parts by weight of water
Add 60 to 200 parts by weight of guanidine salt to 50 parts by weight,
This is a method for producing a foamable flame retardant aqueous solution, which is characterized by converting a condensed phosphoric acid compound into a guanidine salt by reacting at 10 to 80°C.

Furthermore, the present invention provides a general formula (wherein n is a number of 20 or more, Al, A2 and A3 may be the same or different and mean H, NH4 or CONH2,
However, 60 to 200 parts by weight of guanidine salt is added to 100 parts by weight of a condensed phosphoric acid compound represented by (Al, A2 and A3 are H at the same time) and 20 to 350 parts by weight, and the mixture is reacted at 10 to 80°C. This is a process for producing a foamable flame retardant aqueous solution, which is characterized by converting a condensed phosphoric acid compound into a guanidine salt, which is then treated with 1 to 00 parts by weight of formaldehyde at 20 to 90°C to form methylol. .

Foaming flame retardants are those that exhibit the performance stipulated in the Fire and Disaster Management Agency Notification No. 63 dated September 3, 1975.
Refers to a flame retardant used in foaming fire retardant liquid, and is mainly applied to existing wood, boards, plywood, walls, etc., and the coating film of the fire retardant liquid is heated to 700 to 800 degrees Celsius or more during a fire. Sometimes it foams to form a strong carbonized layer, and this carbonized layer prevents the spread of fire and suppresses smoke generation.

Representative examples of the sparingly soluble or insoluble condensed phosphoric acid compound of Formula 1 used in the present invention include ammonium polyphosphate, ammonium carbamyl polyphosphate, and carbamyl polyphosphoric acid. Typical examples of guanidine salts include guanidine carbonate, guanidine phosphate, guanidine sulfate, and guanidine sulfamate, with guanidine carbonate and guanidine phosphate being particularly preferred. When carrying out the present invention, 20 to 350 parts by weight of water, preferably 10
100 parts by weight of a condensed phosphoric acid compound is added to 0 to 250 parts by weight, and further 60 to 200 parts by weight, preferably 100 to 180 parts by weight, of a guanidine salt are added and reacted at 10 to 80°C, preferably 50 to 80°C.

This reaction produces a compound in which any one of A1, A2, and A3 of Formula 1 (7) is substituted with guanidine, and its main component is a compound of the following formula (G in the formula means guanidine). Conceivable.

In addition, depending on the amount of guanidine salt used in the reaction, formula 1
A compound in which some of the n A3's are substituted with guanidine is also produced. In this case, if the amount of water is less than 20 parts by weight, the reaction becomes non-uniform and unreacted substances remain, making it impossible to obtain an aqueous flame retardant solution that provides a transparent coating.

Although there is no strict upper limit to the amount of water, if it exceeds 350 parts by weight, the concentration of the aqueous solution obtained will be too dilute and the effect will be low even if applied as is, and it will be inconvenient to apply it repeatedly or concentrate it. . If the amount of guanidine salt is less than 60 parts by weight, all of the condensed phosphoric acid compound cannot be made water-soluble, and the resulting aqueous flame retardant solution will not provide a transparent coating.

Moreover, when it reaches 200 parts by weight, unreacted guanidine salt remains in the aqueous solution, deteriorating the transparency of the coating. In addition, if the reaction temperature is lower than 10℃, the reaction will be difficult to proceed, and 80℃
If the reaction rate is higher than that, the reaction rate is high, and ammonia etc. may be generated rapidly.

These products are foaming flame retardants as defined above and are present in the reaction mixture as an aqueous solution.

The resulting reaction mixture is generally a clear viscous liquid with a pH of 6 to 9, and can be applied directly as a fire retardant solution. The presence of small amounts of unreacted daanidine salt does not interfere. Isolation of the flame retardant is thus generally not necessary, but it can be purified by conventional means, such as distillation of water from the reaction mixture, precipitation with organic solvents, etc. When formaldehyde is applied to the flame retardant obtained in this way, the amino group of guanidine is methylolated, and the solubility in water is further improved, and the compatibility with the resin used in combination is also improved.

This methylolation is carried out by adding formaldehyde to the above reaction mixture in a conventional manner at 20-90°C, preferably at 60-90°C.
It is carried out at a temperature of 70°C. Formaldehyde is preferably used in the reaction in the form of an aqueous solution, and the amount used is from 1 to 100 parts by weight, preferably from 20 to 50 parts by weight, as HCHO, per 100 parts by weight of the compound of formula I. If this amount is less than 1 part by weight, little effect will be produced. If the amount exceeds 100 parts by weight, unreacted formaldehyde will remain in the aqueous solution, and irritating formaldehyde vapor will be generated during drying after coating, which is undesirable. Methylolated products are thought to be mainly compounds of the following formula.

The methylolated product can also be isolated by conventional methods, and the reaction mixture can be used as it is as a fire prevention chemical solution. The amount of water present during the reaction with the guanidine salt and also during the methylolation reaction is not critical.

This is because the resulting reaction mixture can be adjusted to a viscosity (solid content) suitable for use by adding or removing water as necessary. The flame retardant compound (guanidine salt of the compound of formula I and its methylol compound) obtained according to the present invention has a film-forming ability and gives a transparent coating film from an aqueous solution alone, but it is not commonly used as a water-based flame retardant paint. The resins used can also be used in combination with water-soluble or water-emulsifiable or dispersible resins, such as those listed below.

The combination with urea formaldehyde resin, urea melamine formaldehyde resin, melamine formaldehyde resin or phenolic resin improves the flame resistance and increases the gloss and strength of the coating film. The combined use with vinyl acetate resin, acrylic resin, vinyl acetate acrylic copolymer resin or vinyl chloride resin also improves the gloss and strength of the coating. Note that polyphosphoric acid (A, A in formula I).

and A. is H at the same time) cannot be used for the purpose of the present invention because it is easily hydrolyzed by water, its molecular weight decreases, and it becomes orthophosphoric acid due to excess water. The reaction mixture obtained by reacting polyphosphoric acid with a guanidine salt in a similar manner gives a white opaque coating after application and drying. In the Examples below, transparency was determined by the following method.

According to the Fire and Disaster Management Agency notification, the minimum amount of fire prevention chemicals to be applied is 350g/m2 or more, so based on this amount, it is best to use something that will make all the print on the newspaper readable when 350g/m2 is applied to the newspaper. A case where uppercase or lowercase letters cannot be distinguished at all is considered bad. % in examples is weight %
It is.

Example 1 Ammonium polyphosphate (P-0
N.H.

98%) and 200 g of water are mixed, heated to 60° C., and 157 g of daanidine phosphate are gradually added.

Next, it was held at 65-70°C for 15 minutes and then allowed to cool, resulting in a solid content of 56%, pH of 6.5, and viscosity of 1000 cp (20
℃), 454 g of a transparent and viscous liquid (aqueous solution) with a P content of 13.5% and a N content of 12.2% was obtained. This liquid was applied to various processed products at a rate of 350 g/m, and after drying at room temperature for one day, the appearance and flame retardancy were examined. The flame resistance test was conducted in accordance with the provisions of the Ministry of Construction's Guidance No. 3415 (the same applies below).
The results are shown in Table 1. Example 2 Average degree of condensation approximately 10
Ammonium carbamyl polyphosphate (P-0NH4
Mix 200 g of water with 100 g of P-0C0NH2 (about 86% and about 14% of P-0C0NH2) and heat to 60°C.
Gradually add 80 g.

Next, it was held at 65-70°C for 10-15 minutes and then allowed to cool, resulting in a solid content of 57%, pH 8.5, and viscosity 3000-4.
000cP (20℃), P content 6.7%, N content 2
A 0.4% clear and viscous liquid is obtained. This was applied at 350 g/M2 to various processed products, dried at room temperature for one day, and then examined for appearance and flame retardancy. The results are shown in Table 2. Example 3 200 g of water is mixed with 120 g of ammonium polyphosphate (P10NH4 about 94%) having an average degree of condensation of about 30, heated to 60° C., and 170 g of guanidine phosphate is gradually added.

Then, at 50-60°C, 37% formaldehyde aqueous solution 8
1 g was added and held at this temperature for 20-30 minutes; then allowed to cool, solids content 57%, TfI 6.5, viscosity 700.
CP (20°C), P content 12.8%, N content 11.
560 g of a 1% clear, viscous liquid is obtained. This was applied at 350 g/M2 to various processed products, dried at room temperature for one day, and then examined for appearance and flame retardancy. The result. It is shown in Table 3. In this example, when formaldehyde is not used, the viscous liquid and the transparency of the coating film thereof are slightly inferior, but this is not a problem for practical purposes.

In addition, products using formaldehyde are generally better in compatibility with resins. Same ammonium polyphosphate 110 as used in Example 4 and Reference Example Example 1
g and 180 g of water, heated to 75°C, gradually added 160 g of guanidine phosphate, stirred for 30 minutes, cooled to 37°C, and mixed with 90 g of 37% formaldehyde aqueous solution.
was added, held at this temperature for 20 to 30 minutes, and then allowed to cool, resulting in a solid content of 56%, 1116.8, and a viscosity of 800 cP (
20° C.), 530 g of a transparent and viscous liquid with a P content of 13.9% and a N content of 12.1% was obtained.

For reference, the viscous liquid thus obtained was mixed with urea resin (
1:1 with urea melamine resin (Mitsui Toatsu, Euroid 344), 7:3 with polyvinyl acetate (XB2l3l, manufactured by Toa Paint), and acrylic resin ( 4) Made by Hon Carbide, Nikazo Nore FX329) were mixed uniformly at a ratio of 7:3. These liquids were applied to natural grain decorative plywood (5.5 mm) at 350 g/m, and after drying at room temperature for one day, the appearance and flame resistance were examined.

The results are shown in Table 4. Comparative Example 100 g of water was added to 100 g of each of the same condensed phosphoric acid compounds (all white powders) used in Examples 1 to 3, and to this was added (a) urea resin (
(manufactured by Marutomo Chemical Co., Ltd., T-562) 200 g or (b) polyvinyl acetate (manufactured by Toa Paint Co., Ltd., XB-2131) 100 g
Each of the resulting suspensions was applied at a rate of 350 g/m on natural-look decorative plywood, dried for one day at room temperature, and then examined for appearance and flame retardancy.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc.
(except when A_1, A_2 and A_3 are H at the same time)
0 parts by weight and 20 to 350 parts by weight of water to 60 parts by weight of guanidine salt
A method for producing a foamable flame retardant aqueous solution, which comprises converting a condensed phosphoric acid compound into a guanidine salt by adding ~200 parts by weight and reacting at 10 to 80°C. 2 General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, n is a number of 20 or more, A_1, A_2, and A_3 may be the same or different.
(except when A_1, A_2 and A_3 are H at the same time)
00 parts by weight and 20 to 350 parts by weight of water to 6 parts of guanidine salt.
The condensed phosphoric acid compound is converted into a guanidine salt by adding 0 to 200 parts by weight and reacting at 10 to 80°C, and then methylolated by reacting 1 to 100 parts by weight of formaldehyde at 20 to 90°C. A method for producing an aqueous foaming flame retardant solution.