JPS6230181A - Heat-generation composition for heating vessel - Google Patents

Abstract

PURPOSE:To provide the titled composition composed of light burned quicklime and a compound containing water of crystallization, capable of generating heat safely and quickly without causing the deformation or breakage of the vessel, having easily controllable heat quantity, useful for the heating of a food or drink and contained in an essentially sealed state. CONSTITUTION:The objective composition can be produced by granulating or pulverizing (A) light burned quicklime (preferably the consumption of 4N-HCl of the lime is >=600ml after 5min by coarse particle titration) and (B) a compound containing water of crystallization reactive with the component A, releasing the water of crystallization at an elevated temperature (preferably at about >=40 deg.C) and melting by the heat of the reaction [preferably KAl(SO4)2.12H2O and/or NH4Al(SO4)2.12H2O], and charging the granules or powder in an essentially closed heating vessel. The amount of the component B is preferably adjusted to release 0.5-2mol of water participating in the hydration reaction per 1mol of the component A.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat generating composition for a heating container that utilizes the heat of hydration reaction of quicklime.

Conventional technology It is well known that the hydration reaction of quicklime is used as a heat generating composition for food heating, controlled release of insecticides, body warmers, etc., and crystalline water-containing compounds are used as a water supply means. Compositions containing a mixture of these are also known.

For example, in JP-A-56-147882, Nazsi 03・9H20, Na BO2・4
H20, Na H8O4・H20゜Na 2 HPO4-2H20, ZnSo4・7H20
,Na2HPO3・5H20,CO(CH3C0
0) 2 ・4H20°Na 3PO4
・12H20, Zn (NO3)2・6Hz 0S
Ca SO4-2H20, P-toluenesulfone 1S1
A method of generating heat by heating a mixture of crystal water-containing compounds such as 11-hydrate, (Co○H)2 2H20, gallic acid hydrate, and quicklime to 50°C or higher in a water bath was introduced. ing.

Problems to be Solved by the Invention However, depending on the selection of quicklime and the selection of compounds containing water of crystallization even if quicklime is fixed, the reaction rate can be reduced by WJ.
It was difficult to reconcile. In other words, it could not be said to be a sufficient technique to complete the reaction in a short period of time, such as when heating food and beverages. Furthermore, when a heat-generating composition containing quicklime and a compound containing water of crystallization is stored in a substantially sealed heating container, the heating container may be deformed or ruptured due to volumetric expansion of the composition, resulting in leakage of the heated material. There were concerns about this.

However, the present inventors have found that the reaction is completed in a short time (e.g., 5 minutes), which is particularly suitable for heating food and drinks, and that the heating container is hardly deformed in a substantially sealed heating container. We have now invented a heat-generating composition that suppresses volumetric expansion.

A means for solving the problem, that is, the present invention is to provide a method of producing a method of producing a crystalline water containing soft calcined quicklime and water of crystallization which reacts with the soft calcined quicklime, releases crystallized water at an elevated temperature, and melts at the reaction temperature. This is a heat-generating composition for a substantially sealed heating container, the main component being

The soft calcined quicklime used in the present invention was determined to have 4N-HC after 5 minutes in the coarse particle titration method ([Stonestone Handbook] edited by the Digypsum Lime Society, pages 186-187) to measure the digestion rate.
This is quicklime with a consumption rate of about 500 ml or more. Such quicklime is usually obtained by calcining at a relatively low temperature of about 900 to 1200°C, and may contain other substances to the extent that they do not substantially inhibit the hydration reaction between quicklime and water. .

In the coarse particle titration method, if the amount of 4N-HCI consumed after 5 minutes does not reach 500 ml, it is difficult to finish heating the object in a short time (within about 10 minutes).

Furthermore, if the object to be heated is heated within 5 minutes, turn off the 4N-HCI after 5 minutes! If the volume is 600 m 1 or more,
This is preferable since the composition has a faster heating rate.

Next, the crystal water-containing compounds used in the present invention will be explained. These compounds release crystal water at elevated temperatures and are thermally melted by the heat of reaction with soft calcined lime.

When a mixture of soft calcined quicklime and a compound containing water of crystallization is used for heating purposes, it may be exposed to temperatures close to 40°C during storage or transportation, so the water of crystallization must be easily removed at room temperature or around 30°C. Those that are emitted cannot serve their purpose at the time of need. Therefore, a water-of-crystal-containing compound that releases water of crystallization at least about 40° C. or higher is used. Also, about 40
It has been discovered that even if the composition releases water of crystallization at temperatures above ℃, the heat generation and volumetric expansion of the composition are extremely small when the composition is thermally melted by the heat of reaction with soft calcined lime. In addition,
Thermal melting may be either the crystal water-containing compound or the compound after releasing the crystal water reaching the melting point and melting, or the crystal water compound dissolving in the crystal water released and generating heat r' * wl. .

It is not clear why the volume M of the exothermic composition using a crystal water-containing compound that is thermally melted W:' t) is small, but the heat-molten crystal water-containing compound flows to the bottom, and then the volume increases. This is thought to be due to the formation of voids that can absorb expansion.

Specifically, such crystal water-containing compounds include KAI (
804) 2 ・12H20゜NHa At (SO
a) 2.12Hz O.

KCr (804)2 ・12HzO.

Inorganic compounds such as K2 Go (304)2 ・12H20, CH3CO2Na ・3H20゜(CH3CO2
)2 Pb ・3H20゜(C6Hs○7)2Ca3
- Examples include organic compounds such as 4-day 20.

Among the crystal water-containing compounds of the present invention, KAI (SOa) 2 121-1z OtoNH
4Δ1(304)2 .12H201 is particularly preferable because the exothermic composition has extremely small volumetric expansion and is easily available.

The soft calcined lime and the compound containing water of crystallization of the present invention are in the form of granules or powders, and the particle sizes used range from about 5 InIll to about 100 mμ. That is,
If the particle size is too large, there will be many voids between the particles, resulting in poor thermal efficiency, and if the particle size is too small, the particles may become lumpy, making it difficult to mix uniformly.

The ratio of the soft burnt lime and the compound containing water of crystallization in the exothermic composition of the present invention is such that the crystal water of the compound containing water of crystallization reacts with the soft burnt lime to give the composition of the present invention a desired calorific value. υj are mixed together.

If the crystal water-containing compound is used at a rate that is too small to supply water in an amount that is too small compared to the stoichiometric amount that causes the hydration reaction with the soft calcined lime used, the hydration reaction will generally be difficult and the calorific value will be low. The utilization rate of soft-burned quicklime is also low, which is undesirable. In addition, if the crystal water-containing compound is supplied at a rate that is too large than the stoichiometric amount of water that causes a hydration reaction with the soft calcined lime used, a large amount of steam will be generated and the heat of vaporization will be taken away. This is not desirable because the amount of heat generated is small.

According to the research of the present invention, the exothermic composition of the present invention that provides the desired exothermic properties contains water of crystallization in such a manner that water that can undergo a hydration reaction with quicklime is 0.2 to 3 moles per mole of quicklime. Preferably, the compounds are formulated. That is, if it is less than 0.2 mol, a large amount of unreacted quicklime remains, and if it exceeds 3 mol, not only will the amount of exothermic composition required for heating increase, but also steam will protrude during the reaction, making it dangerous to handle. Particularly preferably 0
．． It was prepared in a range of 5 to 2 moles.

The substantially sealed heating container of the present invention is an object to be heated that has a sufficient degree of sealing to prevent moisture absorption during storage, and has a structure that functions as a water supply or a vent for steam, etc. during use. Aluminum is usually used as the material for the container, which is either pre-assembled in the container or cartridge type, due to its ease of processing and good heat conduction.

The exothermic composition for a heating container of the present invention does not react at room temperature, but if a heat source sufficient to start the reaction is applied to a part of the exothermic composition, the exothermic composition will react one after another due to heat accumulation due to the hydration reaction. continues. For example, a heat source such as pine or explosives may be used to release water of crystallization from a compound containing water of crystallization to initiate a reaction with the soft calcined lime, or a small amount of water may be poured to water some of the soft calcined lime. A sum reaction can occur and the reactions can be continued one after the other.

Function: The heating container heat-generating composition of the present invention can safely heat the heating container at a desired time without deforming or rupturing the heating container. Further, since heating is completed in a short time and the amount of heat generated can be easily adjusted to a desired value, it can be used for heating and keeping food and drinks warm, thawing frozen foods, etc.

Example EXAMPLES The present invention will be specifically described below with reference to Examples.

A cylindrical container with a bottom of diameter 5 (lnm, height 50 mm) (thickness 0
．． Pour the exothermic composition into a 5mm aluminum tube to a height of 45mm, press it lightly with absorbent cotton, and
Aluminum M (thickness 0.51
1Il) to form a heat generating container.

Next, put 20℃ of water into the plastic beaker of 3001.
01, and when the heat generating container is submerged in water to a depth of 45 mm, it is fixed. (Put the holed lid up.) Stir the water in the plastic beaker with a magnetic stirrer, and use a syringe to inject 1 c of water into the heating container through the hole in the lid.
Inject the water in step c and allow the exothermic composition to react.

For evaluation as a heating element, changes in temperature of water and the heating composition, volumetric expansion of the heating container after reaction, and deformation of the container were investigated.

Examples 1 to 3 Soft calcined quicklime was crushed and sieved into powder having a size of about 30 to 80 tiles. As a result of analyzing the quicklime using a coarse particle titration method, the amount of 4N-HCI consumed after 5 minutes was 527 ml.

Next, as shown in Table 1 below, the compound containing water of crystallization was pulverized and sieved to about 10 to 100 tile mesh, and the mixture was uniformly mixed with the soft calcined quicklime to conduct an experiment.

Comparative Example 1 Fe 804 was used as the crystal water-containing compound in Example 2.
- 7H20 was used.

Comparative Example 2 In Example 2, reagent 1 @ quicklime was used instead of soft burnt quicklime. In addition, as a result of analysis of reagent grade 1 quicklime by coarse particle titration method, 4N-HCl after 5 minutes was 120 ml T
” Atta.

Figure 1 shows the temperature changes of the exothermic compositions in Examples 1 to 3 and Comparative Examples 1 and 2, and the 15 Gj filtrate in Example 2 and Comparative Example 2.

Table 1 Examples 4 to 6 Soft calcined quicklime was ground and sieved to about 10 to 20 mesh pieces. The quicklime was analyzed by coarse particle titration, and the amount of 4N-1-ICI quenched after 5 minutes was 780 ml.

Next, as shown in Table 2 below, the compound containing water of crystallization was pulverized and sieved into a powder of approximately 10 to 20 tiles, and the mixture was uniformly mixed with the soft calcined quicklime to conduct an experiment.

Comparative Example 3 M! J CO3
- 3+-120 was used.

The temperature changes of the exothermic compositions in Examples 4 to 6 and Comparative Example 3 and of the water in Example 5 are shown in FIG.

As explained above in Table 2, the heat-generating composition of the present invention reaches a high temperature in a relatively short period of time, and has a small volume per shadow, making it an extremely useful composition in practice. suitable for use.

[Brief explanation of the drawing]

FIGS. 1 and 2 are graphs showing the exothermic temperatures of the exothermic compositions of Examples and Comparative Examples and the temperature of water heated thereby. Patent applicant Asahi Kasei Industries Co., Ltd. Agent Patent attorney Hide Komatsu Agent Patent attorney Koga Asahi 1 Illustration 2

Claims (3)

[Claims] (1) Main ingredients are soft-burned quicklime and a compound containing crystallization water that reacts with the soft-burned quicklime, releases crystallization water at elevated temperatures, and melts thermally through the reaction. A heat generating composition for a substantially sealed heating container. (2) Soft calcined lime is 4N after 5 minutes in coarse particle titration method.
- The exothermic composition for a heating container according to claim (1), which has an HCl consumption of 600 ml or more. (3) The exothermic composition for a heating container according to claim (1), wherein the crystal water-containing compound is potassium alum, ammonium alum, or a mixture thereof.