JPH0120268B2 - - Google Patents

Description

[Detailed description of the invention]

In general, durable flame-retardant processing of fabric is done by impregnating the flame-retardant with a processing solution containing a combination of an initial condensate of a thermosetting resin and a catalyst, drying it, and then heat-treating it to fix the agent to the fabric. A method is being used to make it flame retardant. Although this method can impart durable flame retardancy to the fabric, free formaldehyde may be detected in the fabric after processing due to the resin used in combination.
It also has the disadvantage of being stiffer than unprocessed fabric. This is not a big problem in the case of interior decoration items such as curtains and yutan, but in the case of clothing materials that are used in direct proximity to or contact with the skin, there are concerns about wearability and clothing damage. It is desired that free formaldehyde is not detected and that the fabric does not become stiff and has a good feel. Conventionally, the method of applying vinyl phosphonate oligomer as a flame retardant processing agent uses N-methylolacrylamide as a resin used in combination, and the fixing method by heat treatment uses potassium persulfate as a catalyst and processes in the state of an aqueous solution. Furthermore, in a fixing method using an electron beam, a method in which N-methylolacrylamide is used and processed in a non-aqueous solvent such as alcohol has been reported. However, since both methods use N-methylol acrylamide, it has been pointed out that there are problems such as a considerable amount of free formaldehyde being detected in the processed fabric and a stiff texture. The method of the present invention is a method in which a single aqueous solution of flame retardant is impregnated without using resin or the like, and after drying, it is irradiated with an electron beam to fix it. Therefore, the vinylphosphonate oligomer is directly grafted onto the hydroxyl groups of the fiber. Polymerizes to form strong chemical bonds. Therefore, the fabric after processing has the following characteristics: (1) free formaldehyde is not detected, (2) the fabric does not become stiff, and (3) a flame-retardant fabric with extremely high durability can be obtained. In addition, this method involves impregnating the fabric with vinylphosphonate oligomer in the form of an aqueous solution and irradiating it with an electron beam after drying, so all operations other than the electron beam irradiation step should be performed in the same manner as the conventional method. It has the advantage of being able to Note that a method of irradiating radiation other than electron beams has the same effect. The contents will be explained below using some examples. Example 1 20% and 25 of vinylphosphonate oligomers
% aqueous solution with and without addition of N-methylol acrylamide at 5% and 10%, impregnated it on a cotton cloth, squeezed it 100%, dried it, and exposed it to an electron beam of 6 megarads (hereinafter referred to as Mrad). Irradiated.

【table】

[Table] The electron beam irradiation method was 175KV.3mA, and the electron beam dose was adjusted by the moving speed of the irradiated cloth. The irradiation was performed in a nitrogen atmosphere, and the oxygen concentration was 300 ppm.
The following was made. Even if N-methylol acrylamide is not used as shown in Table 1, the amount of vinyl phosphonate oligomer used (in this case, the aqueous solution concentration is 25%)
can provide excellent flame retardancy. Example 2 The amount of vinylphosphonate oligomer used was 25% of the cotton cloth, and when N-methylol acrylamide was used in combination, the effect of the amount used on the amount of residual free formaldehyde was measured. The experimental method was almost the same as in Example 1. As shown in Table 2, when N-methylolacrylamide is used, the amount of residual free formaldehyde cannot be reduced to zero even after the soaping step after processing. However, if it is unused, it will not be detected.

【table】

[Table] Example 3 The amount of vinyl phosphonate oligomer used was 25% of the cotton fabric, and it was measured how the amount of N-methylolacrylamide used in combination affected the stiffness of the fabric after processing. The measurement was based on the bending resistance test JIS L 1004 slide method. As shown in Table 3, as the amount of N-methylolacrylamide used increases, the bending resistance value increases.
It is the smallest when not in use.

[Table] Id Method Example 4 The amount of vinyl phosphonate oligomer used was 25% for cotton cloth, and a test was conducted to examine how the dose of irradiated electron beam affected the evaluation results of the flammability test. As shown in Table 4, there is not much of a difference in flammability for items that have been soaped after processing, but when looking at the flammability test results after 30 repeated washings, it appears that the magnitude of the electron beam affects the results; This indicates that the carbonized area is smaller and the processing effect lasts longer.

[Table] Oxygen flow rate Limiting oxygen index =

Claims (1)

[Claims] 1 Impregnating vinylphosphonate oligomer in an aqueous solution into clothing materials made of cellulose fibers and cellulose fibers mixed with polyester fibers,
Thoroughly dry the fibers and thoroughly flush nitrogen during electron beam irradiation to reduce the oxygen concentration in the nitrogen atmosphere.
A method for obtaining a durable flame-retardant fabric that does not detect free formaldehyde by irradiating it with an electron beam at a concentration of 300 ppm or less.