JPS6347840B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a flame retardant for cellulosic materials,
In particular, it is possible to impart flame retardancy that combines excellent flame retardancy and high thermal stability (Hunter whiteness) without substantially adversely affecting the desirable properties of cellulosic materials, and further improves the properties of cellulosic materials. Along with improved strength, it can reduce or avoid rusting problems on metals when using flame retardant treatments or treated materials, and often shows excellent thermal stability improvement without increasing critical adhesion rate. Concerning a unique flame retardant for cellulosic materials. More specifically, the present invention relates to a flame retardant for cellulosic materials characterized by containing a melamine/dicyandiamide/aldehyde modified condensate containing a sulfonic acid group as an active ingredient. , relates to a flame retardant for cellulosic materials containing a guanylurea or ammonium salt flame retardant. Melamine/aldehyde-based or melamine/urea/aldehyde-based sulfonic acid group-containing modified condensates can be used alone or in combination with other additives as water reducers and other admixtures for cement and mortar.
It is known to be incorporated into mortars (for example, JP-B No. 43-21659, JP-B No. 49-44926, JP-B No. 39257-197, JP-B No. 52-13991, JP-B No. 52-Sho.
−36124, Special Publication No. 1983-28330, Special Publication No. 1973-
No. 22460, Special Publication No. 1984-27852, Special Publication No. 1984-43419
No., JP-A-50-29637, JP-A-51-144424,
JP-A-52-66529, JP-A-52-77126, JP-A-Sho
No. 53-145841, JP-A-54-139929, JP-A-53-
No. 13628, JP-A-52-27420, JP-A-50-21024
No., etc.). It is also known that such modified condensates containing sulfonic acid groups can be used as wet strength improvers for paper (US Pat. No. 2,863,842, US Pat.
No. 2949396). However, the latter proposal merely discloses that the sulfonic acid group-containing modified condensate is further converted into an acid colloid and used as a wet strength improver for paper; There is no mention of the use of a modified condensate containing a sulfonic acid group as a flame retardant or as a paper wet strength improver. Further, there is no disclosure whatsoever regarding a melamine/dicyandiamide/aldehyde-based sulfonic acid group-containing modified condensate and its use. The present inventors have been conducting research on improving flame retardants for cellulosic materials such as papers, cellulosic fibers, and the like. As a result, the conventional melamine/dicyandiamide/aldehyde sulfonic acid group-containing modified condensate
Its use as a flame retardant for cellulosic materials, which has never been proposed, shows unique performance as an agent that imparts flame retardancy to cellulosic materials, combining excellent flame retardancy and high thermal stability. I discovered that. Furthermore, the problem of rusting on metals during flame retardant treatment and use of treated materials can be overcome without substantially adversely affecting the desirable properties of cellulose-based materials, and furthermore, the problem of rusting on metals can be overcome without causing an increase in the critical adhesion rate. It has also been found that benefits such as excellent improvement in thermal stability can be achieved without the use of oxidation. Further, a more excellent treatment can be achieved by using the sulfonic acid group-containing modified condensate in combination with a known flame retardant based on acids such as guanidine, guanylurea or ammonium salts, particularly preferably in a combination mode in which both are treated simultaneously. I learned that it can be effective. It is therefore an object of the present invention to provide a new type of flame retardant for cellulosic materials. Another object of the present invention is to provide a method for flame retardant cellulosic materials using the above flame retardant. The above objects and many other objects and advantages of the present invention will become more apparent from the following description. The melamine/dicyandiamide/aldehyde sulfonic acid group-containing modified condensate of the present invention is, for example,
Preferably melamine:dicyandiamide=1:
It can be obtained by reacting melamine, dicyandiamide, aldehyde and sulfonating agent in an aqueous solvent in a reaction molar ratio such as 0.2-3. If the reaction molar ratio of melamine:dicyandiamide is too low, for example, less than 0.2 mol, the melamine/dicyandiamide of the present invention may be used.
When a highly concentrated aqueous solution of a dicyandiamide/aldehyde-based sulfonic acid group-containing modified condensate is produced, for example, a product having an aqueous concentration of about 50 to about 70% by weight, the product becomes extremely viscous over time and difficult to handle, which is not preferred. Further, if the amount of dicyandiamide is too excessive, exceeding 3 moles, the stability of the aqueous solution of the modified condensate of the present invention is poor and a precipitate is formed when left standing, which is also not preferred. Therefore, the reaction molar ratio of melamine:dicyandiamide is 1:0.2 to 3 as exemplified above.
A molar amount is preferably adopted, but 1:0.4 to 2
Mole is more preferred. The amount of aldehyde used to form the melamine/dicyandiamide/aldehyde sulfonic acid group-containing modified condensate of the present invention can be appropriately selected within a wide range, but is approximately 1 per mole of melamine and dicyandiamide in total. The amount used is preferably about 6 moles, more preferably about 2 to about 5 moles. When the amount of aldehyde is less than about 1 mole, the resulting condensate tends to be water-insoluble, and when it exceeds about 6 moles, not only does the amount of unreacted formaldehyde increase, but also the flame retardancy tends to decrease. Therefore, it is preferable to adopt the above-mentioned preferred amounts. The aldehyde used is usually an aqueous formaldehyde solution, but formaldehyde polymers such as paraformaldehyde and trioxymethylene can also be used. In addition, acetaldehyde, glyoxal, etc. can also be used as desired. The sulfonating agent used in the sulfonic acid group-containing modified condensate of the present invention can be appropriately selected in a wide range of amounts;
About 0.1 to about 1 mol is preferably used. More preferably, it is about 0.2 to 0.8 mol.
If the amount is too small, less than about 0.1 mole, the condensate formed tends to be water-insoluble, and even if water-soluble products are obtained, they tend to form unstable, water-insoluble precipitates. Furthermore, if the amount exceeds about 1 mol, a crystalline precipitate is formed, which is thought to be caused by the excess sulfonating agent, and the aqueous solution tends to turn yellow. It is best to use an appropriate amount. As the sulfonating agent, a water-soluble salt of sulfite and an alkali metal is usually preferably used, such as sodium metabisulfite,
Potassium metabisulfite, sodium bisulfite,
Preferred examples include potassium hydrogen sulfite.
If desired, ammonium hydrogen sulfite, Rongarit, etc. can also be employed. The melamine/dicyandiamide/aldehyde sulfonic acid group-containing modified condensate of the present invention can be produced by reacting melamine, dicyandiamide, aldehyde, and a sulfonating agent in an aqueous solvent. According to one embodiment, melamine, dicyandiamide, and aldehyde are reacted in advance in an aqueous solvent to produce a melamine/dicyandiamide/aldehyde condensate, and then a sulfonating agent is added to carry out the sulfonation reaction. You can get the desired object. According to this embodiment, for example, melamine, dicyandiamide, and aldehyde are mixed in an aqueous solvent under weakly acidic to weakly alkaline conditions, preferably at a pH of about 6 to about 9, at about 50°C to about 100°C. A melamine/dicyandiamide/aldehyde-based sulfonic group-containing modified condensate can be obtained by reacting at a temperature of about 100%. This condensate is usually obtained in the form of a mixture of various degrees or degrees of methylolation and/or condensation, and these degrees or degrees are:
It can be changed as appropriate by selecting reaction conditions such as PH conditions, reaction temperature, and reaction time. In the above embodiment, depending on the degree of methylolation and the degree of condensation, an aqueous solution of the condensate (for example, a concentration of about 30 to about 70
Preferably, the reaction conditions are selected such that a condensate is formed which is not substantially water-insoluble (% by weight). A sulfonating agent is added to the melamine/dicyandiamide/aldehyde condensate thus obtained, and the reaction is carried out at a temperature of about 50°C to about 100°C, for example, under conditions of a pH of about 9 to about 12. At least the object of the present invention can be obtained. Furthermore, according to another embodiment, the melamine/dicyandiamide/aldehyde-based modified condensate containing a sulfonic acid group of the present invention is prepared by introducing all raw materials of melamine, dicyandiamide, aldehyde, and sulfonating agent into an aqueous solvent and reacting them. It can also be produced by According to this embodiment, for example, melamine, dicyandiamide, aldehyde, and a sulfonating agent are mixed in an aqueous solvent under neutral to weakly alkaline conditions, preferably at a pH of about 7 to about 12, for example, at about 50°C to The object of the present invention can be obtained by reacting at a temperature of about 100°C. Even in the case of this embodiment, the target product is usually obtained in the form of a mixture with various degrees or degrees of methylolation and/or condensation, and these degrees or degrees are different from the PH It can be changed as appropriate by selecting reaction conditions such as reaction temperature, reaction time, etc. The aqueous solution of the melamine/dicyandiamide/aldehyde sulfonic acid group-containing modified condensate of the present invention thus obtained is preferably selected to have a concentration (solid content) of, for example, about 30 to about 70% by weight. The resulting aqueous solution of the sulfonic acid group-containing modified condensate has a pH of about 8 to about 12, but if desired, a suitable acid such as sulfuric acid, hydrochloric acid, acetic acid, oxalic acid, sulfamic acid, phosphoric acid, etc. The pH can be adjusted to about 6 to about 8 using an organic acid. Further, a portion (less than about 50% by weight, preferably less than about 40% by weight) of the above-mentioned melamine/dicyandiamide/aldehyde-based sulfonic acid group-containing modified condensate of the present invention is added to the above-mentioned known cements and mortars. It can be replaced with a sulfonic acid group-containing modified condensate of melamine/aldehyde type or melamine/urea/aldehyde type used as a water reducing agent and other admixtures. For example, the melamine/dicyandiamide/aldehyde sulfonic acid group-containing modified condensate of the present invention, which can be produced by the method exemplified above, can be used alone as a flame retardant for cellulosic materials, and can be used as a flame retardant for cellulosic materials. It exhibits unique performance as a flame retardant agent that combines excellent flame retardancy and high thermal stability. Furthermore, the sulfonic acid group-containing modified condensate can be treated in combination with known flame retardants based on acids such as guanidine, guanylurea or ammonium salts, particularly preferably in a combination mode in which both are treated simultaneously. Effects can be obtained. The processing effects of the above-mentioned combination mode will be explained below with reference to the drawings. In Figures 1 to 6, the horizontal axis shows the critical adhesion rate (minimum flame retardant adhesion rate, weight % that passes flame retardant class 2 specified in JIS Z-2150), and the vertical axis shows the thermal stability ( The graph shows the Hunter whiteness (Hunter whiteness) of flame retardant treated paper after being heated at 200°C for 5 minutes when flame retardant is applied at the limit adhesion rate. The test method was as follows. In addition, 65 g/m ² wallpaper base paper was used as the sample paper material. Critical adhesion rate: According to JIS Z-2150, measure the lowest flame retardant adhesion rate (dry pick-up on paper) that passes JIS flame retardant class 2 (charring length 10 cm or less). The smaller the value, the better the flame retardancy. Thermal stability: Treated paper to which the flame retardant limit has been deposited is kept in a hot air dryer at 200±1°C for 5 minutes, then taken out and Hunter whiteness is measured according to JIS P8123. The larger the value, the better the thermal stability. Usually, when flame retardant treatment of cellulosic materials is performed using two types of known flame retardants for cellulosic materials in combination,
For example, in Figure 1, in the combination system of (a) guanidine sulfamate (Comparative Example 4) and (b) ammonium sulfamate (Comparative Example 5), the performance as a flame retardant is set on the straight line E-E. It can be assumed that there is. However, in actual experiments, a [guanidine sulfamate: ammonium sulfamate =
50:50 (Comparative Example 8)] and b [guanidine sulfamate: ammonium sulfamate = 30:70
(Comparative Example 9)] was plotted below the straight line E, and the flame retardant performance in this combined system was set on the broken line E. As another example, in Figure 2, even in the combined system of (a) guanidine sulfamate (Comparative Example 7) and (ro) diammonium phosphate (Comparative Example 6), in actual experiments a[sulfamine Guanidine acid: diammonium phosphate = 50:50 (Comparative Example 10)]
and b [guanidine sulfamate: diammonium phosphate = 30:70 (Comparative Example 11)], the flame retardant performance of the combined system is as shown in Figure 1.
Broken line E-a-b- located below straight line E-ro
plotted on the screen. Therefore, when two types of commonly known flame retardants for cellulosic materials are used together, the performance is usually much higher than the straight line E-R connecting the flame retardant properties of each, as shown in Figures 1 and 2. It is normal for it to be below the target. However, regarding the flame retardant using the melamine/dicyandiamide/aldehyde sulfonic acid group-containing modified condensate of the present invention in combination with at least one acidic guanidine, guanylurea, or ammonium salt flame retardant, the above-mentioned Figures 1 and 2 When an experiment similar to 2 was conducted, it was surprisingly found that the flame retardant performance was superior to that of the straight E-ro. That is, for example, in Figure 3, (a) and (b') the sulfonic acid group-containing modified condensate of the present invention ((a) Example 1 and (a') Example 2) and (b) guanidine sulfamate. In the combined system with (Comparative Example 4), a (Example 7), b (Example 8),
As shown in c (Example 9) and d (Example 10), both are plotted above the straight line E or E'. Furthermore, in the example shown in Figure 4, the experimental results a( Example 12) and b (Example 13), in Figure 5, in the combined system of (a) the modified condensate containing a sulfonic acid group of the present invention (Example 1) and (b) ammonium sulfamate (Comparative Example 5). In the experimental results a (Example 11), Figure 6, (a) the sulfonic acid group-containing modified condensate of the present invention (example 1) and (b) ammonium sulfamate: ammonium phosphate =
Experimental results a (Example 14) and b (Example 15) for the combination system with 70:30 (weight ratio) (Comparative Example 7)
In each case, each of the two flame retardants is plotted so as to exceed the straight line E, which connects the flame retardant performance of the two flame retardants before they are used together. The reason for this is unknown, but
The unique performance of the sulfonic acid group-containing modified condensate of the present invention is derived from the fact that when used in combination with at least one acidic guanidine, guanylurea or ammonium salt flame retardant, it exhibits a previously unknown synergistic effect. It seems to be. As described above with reference to the accompanying drawings, in the present invention, at least one of a melamine/dicyandiamide/aldehyde-based sulfonic acid group-containing modified condensate and an acidic guanidine, guanylurea or ammonium salt-based known flame retardant is used. It can be seen that, according to the embodiment in which these are used in combination, a previously unknown mutual effect is exhibited. Preferred examples of the acids in the above-mentioned known flame retardants include acids selected from the group consisting of phosphoric acids, sulfuric acids, and water-ammonosulfuric acids. Examples of such acids include phosphoric acids such as orthophosphoric acid, phosphorous acid, hypophosphorous acid, metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, and other condensed phosphoric acids; sulfuric acid, sulfurous acid, hyposulfite, pyrosulfuric acid, etc. Examples include sulfuric acids; and water-ammonosulfuric acids such as sulfamic acid, imidodisulfonic acid, and nitrilosulfonic acid. The acidic guanidine, guanylurea, or ammonium salt-based known flame retardants as exemplified above can be used alone or in combination with the melamine/dicyandiamide/aldehyde-based sulfonic acid group-containing modified condensate of the present invention. As described above, the flame retardant for cellulosic materials of the present invention contains a melamine/dicyandiamide/aldehyde-based modified condensate containing a sulfonic acid group as an active ingredient. Furthermore, according to a preferred embodiment, as described above, at least one acidic guanidine, guanylurea or ammonium salt flame retardant can be further contained. The flame retardant for cellulosic materials of the present invention further comprises:
If desired, other additives such as surfactants, rust inhibitors, PH adjusting agents, moisture absorption inhibitors, sizing agents, etc. can be included. These additives can be used in any amount that does not substantially reduce the flame retardant performance, thermal stability and other desirable properties of the flame retardant of the present invention. The flame retardant for cellulosic materials of the present invention can be in any dosage form, such as powder, granules, pellets, lumps, aqueous liquid, or each active ingredient. Two-drug liquid-liquid type, solid-liquid type or solid-liquid type used together when using
It can also be in solid dosage form. According to a preferred embodiment of the present invention, the cellulosic material is treated with both a melamine/dicyandiamide/aldehyde modified condensate containing a sulfonic acid group and at least one of acidic guanidine, guanylurea or ammonium salt flame retardants. It is possible to provide a method for flame-retardant cellulose-based materials. The treatment can be carried out as long as the flame retardant of the present invention can be sufficiently applied to cellulosic materials such as paper, cotton, hemp, rayon, acetate, etc. or materials containing such materials in any shape, for example, by using an aqueous solution of these materials. It can be applied by any means such as dipping, spraying, sprinkling, roll coating, knife coating, etc. After the treatment, it can be dried to obtain the desired treated product. The flame retardant treatment is preferably carried out with an aqueous solution containing, for example, about 7 to about 60% by weight of the flame retardant of the present invention as a solid content (total solid content if used in combination), and the flame retardant treatment is preferably carried out with an aqueous solution containing about 7 to about 60% by weight of the flame retardant of the present invention. Preferably, the amount is from about 5 to about 40 parts by weight (as solids) per 100 parts by weight of the material. If desired, a squeezing step may be added to adjust the amount of impregnation, and drying may be performed at a temperature of, for example, about 80° C. to about 150° C. to obtain a dried product.
The pH of the treatment liquid is preferably weakly acidic or weakly alkaline, and it is generally preferable to adopt a pH condition of about 5 to about 8. Hereinafter, several embodiments of the flame retardant and flame retardant treatment method of the present invention will be further explained with reference to Examples. The test method is as follows: Solid content (%): Accurately weigh approximately 1 g of the reaction product aqueous solution in a weighing bottle, dry in a hot air dryer at 105 ± 1 ° C for 3 hours, and then calculate from the weight change. and ask. PH: The reaction product aqueous solution was measured at room temperature using a PH meter. Note that 30% sulfuric acid was used as the pH adjuster in this experiment. Solution state: Visually observe the state of the reaction product aqueous solution after pH adjustment. Foam viscosity: After the reaction, the aqueous solution of the reaction product is measured immediately after being cooled to room temperature, and after being left at room temperature for one month, using a foam viscometer. Critical adhesion rate: As mentioned above, according to JIS Z-2150, measure the lowest flame retardant adhesion rate (dry pick-up on paper) that passes grade 2. The smaller the value, the better the flame retardancy. Thermal stability: The whiteness of treated paper coated with flame retardant in the limit amount of adhesion before heat treatment and after heat treatment in a hot air dryer at 200±1°C for 5 minutes is measured as Hunter whiteness according to JIS P8123. The higher the value of Hunter whiteness after heat treatment, the better the thermal stability. Tear strength: For treated paper coated with flame retardant in the limit amount, under standard conditions (20±1℃, relative humidity 65℃)
48 hours at ±1%) and 3 at 200±1℃
Treated paper immediately after being held in a hot air dryer for a minute.
Measure tear strength according to JIS P8116. Rust test: Insect pins were immersed in acetone for at least 24 hours, degreased, washed, dried, and then five pins were immersed in a 30% aqueous solution of each flame retardant, and the time until rust appeared was measured. Example 1 357 g (4.4 mol) of 37% formalin, 126 g (1 mol) of melamine, and 84 g (1 mol) of dicyandiamide were charged into a three-necked glass flask equipped with a stirrer and a condenser (at that time).
PH6.8), and then the reaction is carried out for about 1 hour while keeping the internal temperature at 75 to 80°C and stirring, to obtain a colorless and transparent aqueous solution of the reaction product. After cooling to about 50℃, add 238 g (1.25 mol) of sodium pyrosulfite and water.
141 g of the mixture was added, and the internal temperature was raised again, maintained at 85 to 90°C, and the reaction was carried out for 2 hours with stirring. Then cool to room temperature. The resulting reaction product aqueous solution was clear, had a pH of 11.2, and a bubble viscosity of A to B. Adjust the pH with 30% sulfuric acid at room temperature to reach a pH of 7.5 and solid content.
60.3, and a melamine/dicyandiamide/aldehyde-based sulfonic acid group-containing modified condensate of the present invention having a bubble viscosity of A to B was obtained. The performance of the obtained product as a flame retardant is shown in Table-1. Example 2 37% formalin was used for the same reaction measurement as in Example 1.
405g (5 moles of formaldehyde) and 126 melamine
g (1 mol), dicyandiamide 84 g (1 mol)
and 238 g (1.25 moles) of sodium pyrosulfite.
and 127g of water, keeping the internal temperature at 85-90℃,
React for about 3 hours while stirring. After that, it is cooled to room temperature to obtain a clear aqueous solution with a pH of 10.8. Adjust the pH of this with 30% sulfuric acid at room temperature to PH7.6.
A sulfonic acid group-containing modified condensate of the present invention having a solid content of 59.3 and a bubble viscosity of A to B was obtained. The performance of the obtained product as a flame retardant is shown in Table-1. Examples 3 to 6 and Comparative Examples 1 to 2 In Example 1, the reaction raw materials were changed to the types and amounts listed in Table 1, and the amount of water added was adjusted, or the solid content was adjusted by using paraformaldehyde in formalin. The reaction was carried out in the same manner as in Example 1 to obtain an aqueous solution of the reaction product. The properties of the obtained aqueous solution and the performance of the product as a flame retardant are shown in Table-
Shown in 1. Comparative Example 3 The performance of the wallpaper base paper (65 g/m ² ) used alone to measure the performance of the reaction product as a flame retardant was measured and shown in Table 1. Examples 7 to 15 and Comparative Examples 4 to 11 Regarding the combination system of the melamine/dicyandiamide/aldehyde sulfonic acid group-containing modified condensate of the present invention and the acidic guanidine, guanylurea or ammonium salt flame retardant, the results are shown in Table 2. The flame retardant performance of each formulation was measured and shown in Table 2. For Comparative Examples 4 to 11, only the critical adhesion rate and thermal stability were measured. In addition, the drugs used are as follows. Guanidine sulfamate: Industrial grade, purity 95.3% Ammonium sulfamate: Industrial grade, purity 99.8
% diammonium phosphate: reagent grade 1

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【table】 [Brief explanation of drawings]

The accompanying drawings, FIGS. 1 to 6, are graphs showing the relationship between thermal stability and critical adhesion rate for examples of the present invention and several comparative examples.

Claims (1)

[Scope of Claims] 1. A flame retardant for cellulosic materials, characterized in that it contains a melamine/dicyandiamide/aldehyde-based modified condensate containing a sulfonic acid group as an active ingredient. 2. The flame retardant according to claim 1, further comprising at least one acidic guanidine, guanylurea or ammonium salt flame retardant as an active ingredient. 3. The flame retardant according to claim 2, wherein the acid is selected from the group consisting of phosphoric acids, sulfuric acids, and water-ammonosulfuric acids. 4 Melamine of the sulfonic acid group-containing modified condensate:
The flame retardant according to any one of claims 1 to 3, wherein the reaction molar ratio of dicyandiamide is 1:0.2 to 3 moles. 5. Flame retardant for cellulosic materials, which is characterized in that cellulosic materials are treated with both a melamine/dicyandiamide/aldehyde-based sulfonic acid group-containing modified condensate and at least one acidic guanidine, guanylurea, or ammonium salt-based flame retardant. method.