JPH01254580A - Compound of heating agent and vessel for heating foodstuff - Google Patents

Abstract

PURPOSE:To promote a rapid exothermic hydration reaction and not to leave non-reactive CaO and to prevent blowing out of excess water, which does not pertain to the exothermic reaction, by mixing specified volume of a water- absorptive material with a material generating heat upon reaction with a specified volume of water. CONSTITUTION:A vessel for heating foodstuffs comprises a vessel 2 filled with foodstuffs 1, a compound 4 of heating agent, a sealed water vessel 6 with inside water 5 and a vessel 3 containing these 3, 4, 5, 6. When unsealing the vessel 6, the compound 4 of exothermic agent reacts with the water. The compound 4 is a mixture of 100 parts in weight of the material generating heat upon reaction with water and 1-50 parts in weight of a hygroscopic material. The material generating heat upon reaction with water may be a material chiefly composed of ordinary CaO. The hygroscopic material is something like synthetic or natural zeolite, induced material from hydrophilic starch and cellulose or polyvinylalcohol copolymer. When unsealing the water vessel to discharge water, the hygroscopic material catches excess water to hold thereby and water and lime are prevented from blowing out of the vessel for heating foodstuffs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a heating agent used to heat food by reacting with water and generating heat, and a heated food container using this heating agent. [Prior Art] In recent years, heated food containers have been widely used that store food and heat it when necessary without using any other heating means to bring the food to a temperature suitable for eating and drinking. This container brings water into contact with a substance that generates heat when it reacts with water (hereinafter referred to as "exothermic agent"), and utilizes the heat of reaction. As exothermic agents, quicklime CaO or those whose main component is CaO are most often used, and the reaction between it and water produces the following: Ca Q + 820 1 + Ca (OH) 2 + 15.2 Kcal! /mo
f! It is. The theoretically necessary water for this hydration reaction is 18 g of H2O for 56 g of caO.
Using this equivalent amount of water should provide the best heating efficiency. This is because adding extra water consumes heat to heat it up and evaporate some of it. However, depending on the structure of the heated food container, it may be better to generate a small amount of water vapor and use that to heat the food, but excess water will blow out of the heated food container along with CaO during the reaction, resulting in waste. Instead, it poses a danger. ,
However, even if an equivalent or near equivalent amount of water is supplied,
Uniform contact between CaO and H2O cannot be achieved due to the way water is applied to the heating agent, the permeability of water in CaO, etc., and unreacted CaO remains. For this reason, actual heated food containers contain 20 to 30% more water than the theoretical amount.
0%, sometimes even more. Therefore, it is possible to carry out the hydration reaction without leaving any unreacted CaO and to ensure that the temperature of the food increases at the desired rate, while using the minimum amount of water necessary. desirable. [Problems to be Solved by the Invention] In view of the above, an object of the present invention is to rapidly advance the hydration exothermic reaction, leave no unreacted CaO, and furthermore, eliminate excess water that does not participate in the exothermic reaction, such as blowing out. An object of the present invention is to provide a heated food container capable of preventing the above-mentioned heating, and a heating agent composition used therein. [Means for Solving the Problems] The heating agent composition of the present invention contains a substance 1 that generates heat by reacting with water.
00 parts by weight and 1 to 50 parts by weight of a water-absorbing substance are mixed therein. The substance that generates heat when reacting with water may be a commonly used substance containing CaO as a main component. Examples of water-absorbing substances include synthetic or natural inorganic porous materials such as zeolite, derivatives of starch or cellulose that have been modified to make them more hydrophilic, or polyvinyl alcohol copolymers, such as copolymers of vinyl alcohol and acrylic acid. Polymer water-absorbing agents mainly composed of polymers are useful. It is preferable that the particle size of the pyrogenic substance and the particle size of the water-absorbing substance be approximately the same, so that they can be mixed uniformly. Both have a particle size of 0.5 to 5. OrIIM level is advantageous for water penetration. As a typical example is shown in the drawing, the heated food container of the present invention includes a container (outer container in the illustrated example) 2 filled with food 1;
A heating agent 4 that reacts with water and emits water 5 is added and sealed.
For example, it is composed of a plastic water container 6 and a container (in this case, an inner container) 3 containing these, and an unsealing means 7 for unsealing the container 6 and causing the water and the exothermic agent to react, for example, an axially stretched film. A heated food container equipped with a traction tape adhered to the lid is characterized in that the heating agent composition 4 consisting of the above-mentioned exothermic substance 41 and water-absorbing substance 42 is used as the exothermic agent. As shown in the figure, it is recommended that a water-absorbing sheet-like material, for example, water-absorbing cardboard 8, be provided at the bottom of the container 3 containing the exothermic composition 4 and the water container 6. As such water-absorbing cardboard, use may be made of A corrugated cardboard, A/B corrugated cardboard, E/A/B corrugated cardboard, etc., with NC liner paper or the like having good water absorption attached to the surface thereof. As means for opening the water container, in addition to the illustrated traction tape, means such as piercing or tearing pins or cutters can be used. (Function) As mentioned above, in heated food containers, 20 to 30% or more water than the theoretical amount is contained in the container, and there is surplus water that does not participate in exothermic reactions.Use surplus water. This is absolutely necessary in order to allow water to penetrate throughout the exothermic agent in a short period of time.According to the present invention, when the water container is opened and the water is released,
The water-absorbing material in the heating agent composition captures and retains this excess water, preventing water and lime from escaping from the heated food container, eg, through a steam outlet. If a water-absorbing sheet-like material is provided at the bottom of the container containing the exothermic agent and water container, even if there is excess water that falls downward without contacting the water-absorbing material, this will absorb and retain it. The effect of this will be ensured. Zeolite, which is a typical water-absorbing substance, does not participate in the exothermic hydration reaction, but it also releases heat of adsorption when capturing water, so heating excess water actually lowers the heat generation efficiency compared to theory. This can be prevented to a large extent. As a result, the food heats up more quickly. The action of the heating agent composition of the present invention, in which the heating agent contains an appropriate amount of a water-absorbing substance, is as described above. The amount of water-absorbing substance is appropriately determined depending on the size of the container, the temperature at which the food is heated, the difficulty of heating, and the amount of surplus water provided by other factors, but generally, as mentioned above, 100 parts by weight of the heating agent is used. 1 to 50 parts by weight. If the amount is less than 1 part by weight, it will not be able to be uniformly dispersed in the exothermic agent to produce a sufficient water absorption effect, while if the amount is more than 50 parts by weight, the heating agent will be diluted and the calorific value will increase accordingly. This will result in a decline. According to the provisions of the Fire Service Act, there is a limit to the storage amount of quicklime, which is a typical heat generating agent, if it has a concentration exceeding 80%.For this reason, in heating food containers, quicklime is often diluted with kansui stone, etc. to reduce the CaO content. 80% or less. Mere dilution only causes a decrease in calorific value, but according to the present invention, this regulation can be advantageously cleared. [Example and Comparative Example] Using a container with the structure shown in the drawings, the container was heated at 10°C for 1 hour instead of food.
The heating effects of various heating agents were measured using 80 d of water as the object to be heated. The heating agent composition used and the measurement results are shown below. Nα1 to Nα3 are examples using the heating agent of the present invention, and Nα4 to Nα6 are comparative examples using only a conventional heating agent. Soyu Cab Nia 0g Jukan Suiseki: 20g + Zeolite: g Water = 27g Reached temperature: 50℃ Bubble: None 2 Cab: 60g Jukan Suiseki: 20g + Polyvinyl alcohol water absorbent [Aqua Reserve AP-62J [Nippon Gosei Chemical Industry] ■Product]: 59 Water: 27 tJ Reached temperature: 50°C Bubble-free Kodan Cab: 45g Jugaruyaki dolomite (inorganic porous water absorbing agent,
CaO content 55%): 45g Water: 279 Reached temperature: 53℃ Blowout: None Nα4 Cab Ni 0g Jukan Suiseki: 20g Water = 279 Reached temperature = 45℃ Blowout: Yes Nα5 CaO Ni 0g Jukan Suiseki: 20g Water: 22g Reached temperature = 44℃ No blowout Nα6 Cab near 0g Water = 273 Reached temperature: 46℃ Blowout: Yes As is clear from the above results, the heating agent of the present invention efficiently heats the contents. There is no gushing or leakage of water or lime. [Effects of the Invention] The heated food container using the heating agent composition of the present invention can safely and efficiently heat foods such as sake, coffee, tea, shiruko (shiruko), soup, and oden. There is no danger of lime, lime, or leakage.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view for explaining an example of the heated food container of the present invention. 1... Heated food 2... Outer container 3... Inner container 4... Heating agent composition 41... Exothermic agent 42... Water absorbing substance 5...
・Water 6...Water container 7...Container opening means 8...Water-absorbing sheet-like product Patent applicant: Dainippon Printing Co., Ltd. Representative Patent attorney: Souo Suga

Claims (3)

[Claims] (1) A heating agent composition prepared by mixing 1 to 50 parts by weight of a water-absorbing substance with 100 parts by weight of a substance that generates heat by reacting with water. (2) Claim 1 in which a synthetic or natural zeolite, a hydrophilic starch or cellulose derivative, or a polyvinyl alcohol copolymer is used as the water-absorbing substance.
The heating agent composition described in . (3) Consists of a container filled with food, a heating agent that reacts with water to generate heat, a water container filled with water and sealed, and a container that houses these. In a heated food container equipped with an opening means for causing a reaction,
A heated food container characterized in that the heating agent composition according to claim 1 or 2 is used as a heating agent.