JPH0149828B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a flame retardant processing method for fibers. [Prior art] As a method for making fiber materials such as yarn and cloth flame retardant, there is a proban processing method using a condensate of urea with tetrakis(hydroxymethyl)phosphonium sulfate, etc., and N-methyloldimethylphosphonopropionamide. (Ciba Geigy's Pyrobatex CP) (hereinafter referred to as "Pyrobatex CP")
Conventionally, methods such as "CP method" have been used. [Problems to be solved by the invention] Among the above-mentioned methods, the proban processing method provides durability by forming a proban polymer in the fibrils of cotton fibers, so it has excellent washing resistance. However, since it requires special equipment for ammonia curing to form a polymer and an oxidation process using H ₂ O ₂ , the feel of the cotton fiber deteriorates. Moreover, since the dyed product changes color and its light fastness deteriorates, reactive dyes and the like cannot be used, and only expensive vat dyes can be used. Butt dyes also had the problem of poor color. On the other hand, in the Pyrobatex CP method, since trimethylolmelamine is used in combination, the strength of the fibers decreases, especially the tear strength, and the strength retention rate decreases to about 50% (Tokyo Metropolitan Textile Industry Research Institute Research Report No. 32) Issue p.51 (1984) Susumu Saito, Akiyama
There are problems such as those written by Katsuo. Tris (1-
There are methods using aziridinyl) phosphine oxide, and methods using tris(2,3-dibromopropyl) phosphate, bis(2,3-dibromopropyl) phosphate, etc. as a flame retardant for polyester fibers. The use of flame retardants is currently prohibited by the Ministry of Health and Welfare's ``Act on the Regulation of Household Products Containing Hazardous Substances.'' Moreover, polyester/cotton blend (hereinafter referred to as "E/
In the case of fabrics (denoted as "C"), melt dripping of the polyester fibers is prevented due to the so-called Scaf fold effect. Therefore, the flammability is
Compared to polyester fibers and cotton fibers alone, flame retardant processing becomes more difficult, and E/
Currently, there is no flame retardant agent with sufficient washing resistance for C fabrics etc. [Written by Shojiro Oe]
See Polymer Processing 23 , 76 (1976), Katsuura Yoshitsugu Kasei Monthly Report 12 (4), 58 (1974)]. [Means for solving the problem] In order to solve the above-mentioned problems, the present invention impregnates a raw material fiber with a flame retardant agent, dries it, and then cures it to make the raw material fiber flame retardant. In the method for flame retardant processing of fibers, the flame retardant is an aqueous solution consisting of an aminophosphazene derivative in which at least one hydrogen of the amino group of aminophosphazene is substituted with a methylol group or a methoxymethyl group, and an acid catalyst. The gist is a flame-retardant processing method for fibers that has certain characteristics. [Function] According to the method for flame retardant processing of fibers according to the present invention, the aminophosphazene derivative is crosslinked by cure, and the methylol group in the derivative is formed by the following formula, N-CH ₂ OH + HO- Cell acid catalyst――→ N-CH ₂ O-Cell + H ₂ O Reacts as shown. It also reacts in the same manner with fibers having -SH groups or amino groups. On the other hand, the methoxymethyl group is also hydrolyzed to become a methylol group and reacts in the same way. Due to the above reaction, it has excellent tear strength, wrinkle resistance,
In particular, flame-retardant fibers with improved moisture wrinkle resistance, soft texture, and excellent wash resistance can be obtained. Furthermore, since the fibers are crosslinked, shrink resistance is also improved. Moreover, since it is not necessary to use an ammonia cure method or an oxidation step using H ₂ O ₂ , problems such as discoloration of the reactive dye are eliminated. [Examples] The present invention will be described in detail below with reference to Examples. Aminophosphazene has the following general formula, It is a general term for those represented by the following, and trimers or tetramers in which n is 3 to 4 are generally used, but pentamers or more may also be used. Aminophosphazenes are methylolated, for example, by reacting with the required amount of formaldehyde. The detailed method is as follows. That is, for example, a required amount of 37% formaldehyde aqueous solution (formalin) is added to a reaction vessel (for example,
into a three-necked round-bottom flask). While stirring the formaldehyde aqueous solution, the pH is adjusted to 8 to 9 with a 5% sodium hydroxide aqueous solution, and the aminophosphazene aqueous solution is dropped into the reaction vessel. Thereafter, while maintaining the pH at 8 to 9, the mixture is heated to 50 to 60°C and stirred for 1 hour to react. After the reaction is completed, the solvent is distilled off using an evaporator or the like, and the reaction solution is poured into methanol to precipitate methylolated aminophosphazene. The number of methylol groups substituted for the hydrogen atoms of the amino groups of aminophosphazene is determined by the molar ratio of aminophosphazene and formaldehyde placed in the reaction vessel.
For example, two methylolated aminophosphazene trimers A and B obtained with a molar ratio of trimer and formaldehyde of 1:8 and 1:20 have the following numbers of methylol groups in one molecule, respectively. As shown in Table 1.

[Table] Shows the percentage by weight of carbon atoms in the aminophosphazene trimer. The number of groups (n) was calculated from the value of C element (%). Incidentally, in order to obtain a methylolated aminophosphazene trimer having 3 methylol groups, the molar ratio may be set to 1:3. On the other hand, for example, the methylolated aminophosphazene trimer obtained by the above method can be made weakly acidic with oxalic acid and refluxed in a large amount of methanol for about 1 hour to methoxymethylate the methylol groups. After the reaction is completed, the methoxymethylated aminophosphazene trimer can be obtained by neutralizing with sodium hydroxide and removing the produced sodium oxalate by filtration, and then distilling off the methanol in the filtrate using an evaporator or the like. . By the way, A in Table 1
When the methylolated aminophosphazene trimer was methoxymethylated, the number of methoxymethyl groups in the obtained methoxymethylated aminophosphazene trimer was 7.5 (calculated from C=32.16%). The flame retardant agent can be obtained by dissolving the aminophosphazene derivative obtained as described above in water together with an acid catalyst. The concentration of the aminophosphazene derivative in the aqueous solution is preferably about 5 to 50% by weight. If it is less than 5% by weight, there is a tendency that sufficient flame retardant effect cannot be obtained. If it exceeds 50% by weight, the flame retardant effect is sufficient, but the feel tends to be impaired. Examples of the acid catalyst include, but are not limited to, phosphoric acid, 2-amino-2-methylpropanol hydrochloride, ammonium chloride, zinc nitrate, magnesium chloride, and the like. The concentration of the aqueous solution of these acid catalysts is preferably about 0.1 to 10% by weight. When it is less than 0.1% by weight, the flame retardant effect and washing resistance tend to decrease. If it exceeds 10% by weight, there is a tendency for strength to decrease and discoloration to occur. Fibers that can be made flame retardant by the processing method of this invention are not particularly limited as long as they contain OH groups, SH groups, and amino groups, but examples include cotton, silk, linen, and rayon. , wool, etc. Generally, these fibers are subjected to flame retardant treatment in the form of fibrous materials such as threads and cloth. The fiber material may be a blended fiber or a mixed woven fabric. The steps of impregnation, drying, and curing are not particularly limited, but can be performed continuously using a normal pad-dry-cure method. The temperature during drying is preferably about 80 to 120°C.
If the temperature is below 80℃, drying time tends to be longer. The temperature during curing is preferably about 80 to 200°C.
If the temperature is lower than 80°C, the treatment time will be long and the flame retardant effect and washing resistance will tend to decrease. When the temperature exceeds 200℃, there is a tendency for strength to decrease and discoloration to occur. Next, examples will be described in detail. Example 1 300ml of 24.26g of 37% formaldehyde aqueous solution
The mixture was placed in a three-necked flask, and the pH was adjusted to 8 to 9 with a 5% aqueous sodium hydroxide solution. 10 g of aminophosphazene trimer aqueous solution dissolved in 50 ml of water,
It was added dropwise to the 37% formaldehyde aqueous solution with stirring. Furthermore, aminophosphazene trimer and 37
% formaldehyde aqueous solution is 1:8
It was hot. After dropping, keep the liquid temperature at 50-60℃ for 1 hour.
At the same time, the reaction was carried out while maintaining the pH at 8 to 9 to carry out methylolation. After the reaction was completed, the solvent of the solution in the three-necked flask was distilled off and concentrated using an evaporator, and then poured into methanol to precipitate the methylolated aminophosphazene trimer.
The yield of the obtained methylolated aminophosphazene trimer was 98%, and elemental analysis showed that C=19.85%,
H=5.09%, N=28.09%, and the number of methylol groups based on the C content was n=7.6. 30% by weight of the methylolated aminophosphazene trimer obtained by the above method was added to water and 2-
A treatment liquid was obtained by dissolving amino-2-methylpropanol hydrochloride to a concentration of 1.8% by weight. A cotton satin printed cloth was soaked in this treatment solution for 2 dips and 2 nips to impregnate the cloth with the treatment solution. After impregnation, 100℃
It was dried for 3 minutes. After drying, it was cured by heating at 160°C for 3 minutes, and then washed with hot water at 65°C for 5 minutes and dried to obtain a flame-retardant cotton satin printed fabric. The squeezing rate of the treatment liquid after impregnation is
It was 105%. Example 2 The methylolated aminophosphazene trimer obtained in Example 1 was placed in a large amount of methanol, made weakly acidic with oxalic acid, and refluxed for 1 hour to methoxylate the methylol groups. After refluxing, the solution was neutralized with a 5% aqueous sodium hydroxide solution to precipitate sodium oxalate, which was filtered. After filtration, methanol in the filtrate was distilled off using an evaporator to obtain a methoxymethylated aminophosphazene trimer. The yield is 22
%, and the number of methoxymethyl groups was n=7.5. A treatment solution was obtained by dissolving 30% by weight of the methoxymethylated aminophosphazene trimer obtained by the above method and 2.1% by weight of 2-amino-2-methylpropanol hydrochloride as an acid catalyst in water. I got it. After 2 dips and 2 nips of a cotton satin printed cloth were placed in this treatment solution, the cloth was dried at 100° C. for 3 minutes.
After drying, it was cured by heating at 160°C for 3 minutes, and then washed with hot water at 65°C for 5 minutes and dried to obtain a flame-retardant cotton satin printed fabric. The reduction rate of the treatment liquid after impregnation was 106%. Example 3 A methylolated aminophosphazene trimer was obtained in the same manner as in Example 1, except that the molar ratio of the aminophosphazene trimer and the 37% formaldehyde aqueous solution was 1:20. The yield of the methylolated aminophosphazene trimer obtained was ~100
%, the number of methylol groups is n=12.0 (C= in the molecule
24.70). A treatment solution was obtained by dissolving 30% by weight of the methoxymethylated aminophosphazene trimer obtained by the above method and 3.0% by weight of phosphoric acid as an acid catalyst in water. After 2 dips and 2 nips of a cotton satin printed cloth were placed in this treatment solution, the cloth was dried at 100° C. for 3 minutes. After drying, it was cured by heating at 160°C for 3 minutes, and then washed with hot water at 65°C for 5 minutes and dried to obtain a flame-retardant cotton satin printed fabric. The reduction rate of the treatment liquid after impregnation was 114%. Example 4 Cotton satin textile fabric subjected to flame retardant treatment in the same manner as in Example 3, except that 2-amino-2-methylpropanol hydrochloride was used as an acid catalyst and the concentration in the treatment liquid was 2.1% by weight. I got the cloth. The reduction rate of the treatment liquid after impregnation was 104%. Example 5 A cotton satin textile that was flame retardant treated in the same manner as in Example 2, except that the methylol group of the methylolated aminophosphazene trimer obtained in Example 3 was methoxylated in the same manner as in Example 2. I got the cloth. The reduction rate of the treatment liquid after impregnation was 108%. Example 6 A flame-retardant printed cotton satin fabric was obtained in the same manner as in Example 5, except that phosphoric acid was used as the acid catalyst and the concentration in the treatment liquid was 4.0% by weight. The reduction rate of the treatment liquid after impregnation was 106%. Example 7 A methylolated aminophosphazene trimer was obtained in the same manner as in Example 1, except that the molar ratio of the aminophosphazene trimer and the 37% formaldehyde aqueous solution was 1:3. The number of methylol groups in the obtained methylolated aminophosphazene trimer was n=3. Thereafter, a flame-retardant cotton satin printed fabric was obtained in the same manner as in Example 4. The reduction rate of the treatment liquid after impregnation was 114%. Example 8 Example 7 except that amnium chloride was used as the acid catalyst and the temperature in the treatment liquid was 3.0% by weight.
A flame-retardant cotton satin printed fabric was obtained in the same manner as above. The reduction rate of the treatment liquid after impregnation was 113%. Example 9 A cotton satin textile that was flame retardant treated in the same manner as in Example 2, except that the methylol group of the methylolated aminophosphazene trimer obtained in Example 7 was methoxylated in the same manner as in Example 2. I got the cloth. The reduction rate of the treatment liquid after impregnation was 109%. Example 10 A flame-retardant rayon muslin was obtained in the same manner as in Example 2, except that the cotton satin printed fabric was replaced with a rayon muslin. The reduction rate of the treatment liquid after impregnation was 106%. Example 11 A flame-retardant E/C broad was obtained in the same manner as in Example 2, except that the cotton satin printed fabric was changed to E/C (65/35) broad. The reduction rate of the treatment liquid after impregnation was 91%. Example 12 30% by weight of the methylolated aminophosphazene trimer obtained in Example 1 and 2-amino-2-methylpropanol hydrochloride as an acidic catalyst were added to water.
A treatment liquid was obtained by dissolving the solution to a concentration of 2.1% by weight.
Using the obtained treatment solution, a flame-retardant silk habutae was obtained in the same manner as in Example 1, except that silk habutae was made from cotton satin printed cloth. The reduction rate of the treatment liquid after impregnation was 121%. Example 13 A flame-retardant wool muslin was obtained in the same manner as in Example 2, except that the cotton sateen printed fabric was pretreated to improve permeability. The reduction rate of the treatment liquid after impregnation was 100%. Comparative Example 1 A flame-retardant printed fabric was obtained in the same manner as in Example 1, except that purified aminophosphazene that was not methylolated was used in place of the methylolated aminophosphazene trimer. Flame retardant adhesion rate, limiting oxygen index (LOI), and carbonized area by heating for 1 minute using a 45° microburner method for each fabric treated with flame retardant treatment obtained in Examples 1 to 13 and Comparative Example 1 above. , and the flame retardant adhesion rate, limiting oxygen index (LOI), and carbonized area after 1 minute heating using the 45° micro burner method after washing 5 times using the medium temperature (60°C) washer method. Shown in the table. Furthermore, the wrinkle resistance and shrinkage rate of the flame-retardant fabrics obtained in Example 1 and Comparative Example 1 were also investigated. The results are shown in Table 3 in comparison with the case of untreated cotton sateen cloth. The wrinkle resistance was determined using the Monsanto method, and the shrinkage rate was determined using the soap solution method.

【table】

〔Effect of the invention〕

Since the flame retardant processing method for fibers according to the present invention is configured as described above, it has excellent tear strength, wrinkle resistance, especially moisture wrinkle resistance, soft texture, and excellent washing resistance. Moreover, flame-retardant fibers with excellent shrink resistance can be obtained.

Claims (1)

[Scope of Claims] 1. A method for flame retardant processing of fibers in which raw fibers are impregnated with a flame retardant, dried and cured to make the raw fibers flame retardant, wherein the flame retardant is aminophosphazene. 1. A method for flame-retardant processing of fibers, comprising an aqueous solution comprising an aminophosphazene derivative in which at least one hydrogen of an amino group is substituted with a methylol group or a methoxymethyl group and an acid catalyst. 2. The fiber difficulty according to claim 1, wherein the acid catalyst is at least one selected from the group consisting of phosphoric acid, 2-amino-2-methylpropanol hydrochloride, ammonium chloride, zinc nitrate, and magnesium chloride. Fuel processing method. 3. The flame retardant processing method for fibers according to claim 1 or 2, wherein the treatment temperature during curing is 80 to 200°C. 4. The flame retardant processing method for fibers according to any one of claims 1 to 3, wherein the fibers are made of at least one selected from the group consisting of cotton, hemp, rayon, silk, and wool. .