JPH0218358B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a body warmer that utilizes the heat generated when iron is oxidized in the air, such as a disposable body warmer. More specifically, it relates to a body warmer containing a sulfur-containing nitrogen-containing compound. In general, body warmers that utilize air oxidation of iron include:
Contains iron powder, water, neutral metal salts, carbonaceous substances, water retention agents, etc. However, since the reaction of air oxidation of iron is not inherently violent, it takes about 90 minutes to reach the temperature at which the heating effect begins (approximately 30 to 40 degrees Celsius), making it useless in emergency situations.
Furthermore, in cold regions, the rise in temperature at the start of heat generation becomes worse, and it may become unusable. Additionally, this type of body warmer is sealed in an oxygen-impermeable bag to block air to prevent oxidation reactions during storage. However, the reaction between iron and water is progressing, and hydrogen is being generated as a result. This generation of hydrogen poses a risk of explosion and causes the bags to bulge, creating major storage problems. In order to suppress the generation of hydrogen, alkaline substances such as sodium hydroxide and sodium carbonate have traditionally been added. However, the combination of such an alkaline substance is not preferable because it causes a slow rise at the start of heat generation. The inventors of the present invention have conducted intensive research to create a warmer that can improve the rise at the start of heat generation and also suppress the generation of hydrogen, and have found that when blending a sulfur-containing nitrogen-containing compound, the above purpose can be achieved. We have discovered what can be achieved and completed the present invention. Examples of the sulfur-containing nitrogen-containing compound used in the present invention include ammonium sulfide, ammonium thiosulfate, ammonium sulfate, ammonium sulfite, ammonium sulfamate, tetramethylthiuram disulfide, thiourea, and sodium diethyldithiocarbamate. Among them, ammonium sulfide, ammonium thiosulfate, ammonium sulfite, thiourea, sodium diethyldithiocarbamate, tetramethylthiuram disulfide, and the like are particularly excellent in both improving the rise and suppressing hydrogen gas generation. In the present invention, the sulfur-containing nitrogen-containing compound is iron.
30 parts or less per 100 parts (parts by weight, same hereinafter),
It is particularly preferable to blend 0.05 to 1.0 parts. Examples of the iron powder used include reduced iron powder and iron powder obtained by an atomization method. Among them, reduced iron powder is particularly preferred. Warmers that utilize the heat generated by air oxidation of iron contain ingredients such as water, neutral metal salts, carbonaceous substances, and water retention agents in addition to iron as described above. Similar ingredients are blended. Examples of neutral metal salts include sodium chloride, potassium chloride, calcium chloride, etc., but sodium chloride is preferred from the viewpoint of cost and other factors. The carbonaceous material is used as an oxidation catalyst, and, for example, activated carbon powder is preferred, but coconut shell charcoal powder or the like may be substituted as appropriate. Examples of water retention agents include wood chips, vermiculite, fiber powder, superabsorbent resins, or mixtures thereof. The mixing ratio of these is 100 parts of iron powder to 20 parts of water.
~70 parts, carbonaceous material 0.1~80 parts, metal neutral salt 1~
Preferably, the amount is 20 parts and the water retention agent is 1 to 500 parts. Further, if necessary, an appropriate amount of an oxidizing agent may be added. All the components may be mixed at once, but it is preferable to uniformly mix the iron powder and the sulfur-containing nitrogen compound first, and then mix this mixture with the other components. . The bag for enclosing the above-mentioned mixture is usually one consisting of a breathable inner bag and a non-breathable outer bag. There are no other restrictions on the outer bag used in the body warmer of the present invention as long as it is non-breathable, and may be laminated. Preferred materials include nylon, polyester, and polypropylene films treated with moisture-proof treatment such as OPP, CPP, and polyvinylidene chloride, as well as aluminum foil or plastic films coated with aluminum. The inner bag of this type of body warmer is usually made of nonwoven fabric, but any material that is breathable may be used, such as cloth or paper. Next, the body warmer of the present invention will be explained with reference to Examples, but the present invention is not limited to these Examples. Examples 1 to 13 and Comparative Examples 1 to 6 200 g of reduced iron powder was uniformly mixed with the compounds shown in Table 1 in the amounts shown in the table at 24 to 30°C. After thoroughly mixing 25 g of the obtained mixture with 10.5 g of water, 1.5 g of sodium chloride, and 10.5 g of wood chips, the mixture was sealed in an air-permeable bag, and the rising state of the mixture was examined. The bag used was an 80 mm x 120 mm bag made of polyethylene laminated on the inner surface of a nylon nonwoven fabric, with 330 perforations on one side (using needles with a diameter of 0.3 mm) at intervals of 4.3 mm in the center and 6 mm in width. Measurements were carried out in a room where the temperature was maintained at approximately 8°C by shaking the tube several dozen times immediately after sealing it, placing it on top of four blankets, and placing two blankets on top of the thermocouple. . The results are shown in Table 1.

【table】

[Table] Next, iron powder mixtures 30 obtained in Examples 1, 3, 7, 10, 11, and 13 and Comparative Examples 1, 2, and 6, respectively.
g, water 12g, sodium chloride 1.5g, vermiculite 2.5g, activated carbon (E-30, Takeda Pharmaceutical Co., Ltd.)
(manufactured by Sanyo Chemical Industries, Ltd.) 2.5 g, 7 g of coconut shell charcoal, and super absorbent resin (Sunwet IM-30, manufactured by Sanyo Chemical Industries, Ltd.)
After uniformly mixing all the components, 0.83 g was filled into a non-porous aluminum foil bag and vacuum-sealed, and the generation of hydrogen gas was examined. The obtained sealed body was heated in a drying oven at 88-89°C for 8 hours, and the degree of hydrogen gas generation was examined. 35 more
It was stored at ~40°C for 3 months and the degree of hydrogen gas generation was examined. The results are shown in Table 2. The degree of gas generation was visually evaluated using the following criteria. ◎: No change 〇: Almost no change ×: Bags swelled and some even burst.

【table】

[Table] As is clear from Tables 1 and 2, when a sulfur-containing nitrogen-containing compound is blended, the rise time can be halved, and hydrogen gas is not generated. On the other hand, when sodium sulfide, which is a sulfur-containing compound that does not contain a sulfur atom, was blended, although it was possible to suppress the generation of hydrogen gas, the rise was adversely affected; When urea was added, the rise was not improved and the generation of hydrogen gas could not be suppressed.

Claims (1)

[Claims] 1. A hand warmer that uses air oxidation of iron and is formulated with a sulfur-containing nitrogen-containing compound.