【発明の詳細な説明】[Detailed description of the invention]
本発明は、酸素と接触することにより、酸素を
吸収し発熱する組成物の改良に関するものであ
る。
本発明の発熱組成物は金属粉として従来用いら
れている金属鉄、アルミニウム、銅、錫等の中か
ら、発熱性能が優れ、安価で、入手が容易な金属
鉄を使用し、反応助剤としてはハロゲン化金属の
中で最も品質が安定で、手軽さ、経済性が良く、
毒性面で安全性の高い塩化ナトリウムを使用し、
かつ特定量の水およびケイ酸ナトリウム含水塩を
使用したものであり、これにより初期発熱性能が
優れ、長期間安定した発熱が得られ、使用中内容
物の固化がなく、保存中水素の発生がなく、また
流動性が良く製造工程上の充填効率のすぐれた発
熱組成物を提供するものである。
一方、従来の発熱組成物は、鉄、アルミニウム
等の金属又は硫化ソーダとハロゲン化金属、水、
活性炭等を混合して発熱組成物を製造し、化学カ
イロとして使われている。
しかしながら、これら従来のものは遊離水のみ
を使用しているため、使用時、使用初期には水の
供給が過剰で、異常な高温となつたり、逆に全く
発熱しないことが生じる欠点がある。又、初期に
は発熱したが、使用途中より水の供給が不足して
くると、急激に温度が下がり、安定したカイロと
して適当な温度を維持できない欠点がある。その
ために、カイロ使用者は、使用初期にはカイロを
布等で巻きつけ温度を下げ、又使用途中では布を
はずしたり、発熱組成物の反応を促進するために
カイロを揉む等の必要がある。さらに遊離の水を
含むため、発熱組成物全体が均一なものとなりに
くく、その為発熱にむらを生じ、使用途中でもむ
必要がある。また遊離水のみを使用しているため
に、水が揮散しやすくカイロの長期保存中に発熱
組成物内の水が揮散して失なわれ、使用者が使用
しても目的とする発熱が得られない欠点もある。
さらに、鉄と遊離水を共存させると長期保存中
に金属鉄の酸化が生じて水素が発生し、保存袋の
膨張、破損を生じ、また引火爆発の恐れもある。
さらに従来のものは、使用途中で発熱組成物が固
まり身体に異和感を与えた。又、前述の発熱組成
物では多量の遊離水を含有させるため、粉体の流
動性が悪く、自動製袋充填機で高速充填できず、
極めて能率の悪いものである。また、金属鉄、珪
酸および／または珪酸ナトリウム含水塩およびハ
ロゲン化金属を含有する発熱組成物も知られてい
るが、この組成物は初期発熱性能が悪いという欠
点を有している。
本発明者らは、前述の種々の欠点を克服するた
めに研究を進めた結果、本発明に到達したもので
ある。即ち、本発明は(a)金属鉄、(b)塩化ナトリウ
ム、(c)水および(d)ケイ酸ナトリウム含水塩を含有
してなる発熱組成物であつて、該組成物における
(c)水および(d)ケイ酸ナトリウムのそれぞれの含有
量が発熱組成物の重量を基準にして、(c)が10〜25
重量％、(d)が0.5〜15重量％の範囲内にあること
を特徴とするものである。本発明における金属鉄
は還元粉、電解粉、噴霧粉等の粉末状のものがよ
く、通常10メツシユより小さく、50メツシユより
小さいものが好ましい。その量は発熱組成物中、
45〜60重量％、好ましくは50〜55重量％が望まし
い。塩化ナトリウムは１〜10重量％が好ましく、
水は10〜25重量％、好ましくは15〜20重量％が望
ましい。
発熱組成物の初期発熱性能を発現させるために
は、ある程度の量の自由水を配合することは必須
であり、これをケイ酸ナトリウム含水塩の結晶水
で完全に代用することはできない。そして自由水
は含有の保管中に徐々に蒸発するので製造時10重
量％以上配合することが必要であり、また25重量
％以上配合すると組成物がべたつき、流動性が低
下し、使用性、製造工程上の問題がある。又、ケ
イ酸ナトリウム含水塩には種々のものが使用でき
る。例えば、Na2SiO3・4H2O・Na2SiO3・
5H2O，Na2SiO3・9H2Oがあるが、これらの中間
的含水塩でもよく、又必ずしもここに挙げた例に
限られるものではない。ケイ酸ナトリウム含水塩
は、組成物の保存中、金属鉄と自由水との反応に
よる水素の発生を抑制し、発熱開始後結晶水を
徐々に遊離し、安定した温度を維持し、使用中内
容物の固化を防止し、また自由水の量を低減する
ことができるので流動性がよく製造工程上の充填
効率を良くする等の効果をもたらす。本発明に用
いるケイ酸ナトリウム含水塩の量は発熱体組成物
中の量は0.5〜15重量％、好ましくは１〜10重量
部が適当である。0.5重量％未満では水素の発生
を完全に押えられず、また使用中に安定した温度
を維持する面で少し劣り、使用中に内容物が固ま
るのを防げない。一方、15重量％を越えると、発
熱組成物の初期発熱が低下するので好ましくな
い。なおこのケイ酸ナトリウム含水塩の添加方法
としては、粉体まま他の発熱組成物の原料と混合
してもよく、また水に添加して溶解するか、又は
懸濁状態のまま他の発熱組成物の原料と混合して
もよい。さらに本発明の組成物には必要に応じて
充填剤を添加することができる。充填剤としては
金属鉄、塩化ナトリウムおよびケイ酸ナトリウム
含水塩に対して化学的に不活性な無機物、有機物
を用いることができ、特に水に不溶性また難溶性
のものが望ましい。この様なものとして活性炭、
ケイソウ土、酸性白土、硫酸カルシウム、ゼオラ
イト等のものがあり、特に活性炭、ケイソウ土が
好ましい。しかし、これら上記のものに限定され
るものではない。又充填剤の量としては10〜40重
量％、好ましくは20〜30重量％が望ましい。
本発明の発熱組成物は10〜25重量％の遊離水が
配されているため、発熱組成物の初期発熱性能が
極めて優れており、発熱組成物の含水量が減少す
ると、自然に結晶水を放出する性質を有するケイ
酸ナトリウム含水塩の水が作用するために安定し
た温度を維持でき、使用途中で発熱組成物が固ま
らず、またケイ酸ナトリウム含水塩の作用で保存
中の経時変化も極めて少なく、水素の発生もゼロ
ないし、通常のガスバリア性包装材の水素透過性
との関係において何ら問題とならない程度のもの
である。
さらに本発明の発熱組成物は従来のものと比較
して流動性が良いので、自動製袋充填機で高速充
填ができ、極めて有用な発明である。
又、本発明の発熱組成物は単に酸素又は空気と
接触させるのみで発熱することから化学カイロ、
温湿布などの人体の保温、防寒あるいは加温材と
して利用し得るものである。しかし、これらの目
的には、酸素または空気との接触でスムースな発
熱が起り、所定の温度に一定時間保つためにその
酸素又は空気の供給量をコントロールすることが
必要である。本発明の組成物には、これを収納す
る袋の性能としては、片面又は両面に多数の通気
孔を設け、最も近い通気孔間の距離が３cm以下に
なるように通気孔を配置するか、あるいは片面又
は両面に中央部又は中心を通る帯状に部分的な通
気孔を配置し、かつ、酸素通気性が0.1〜５c.c.／
cm2、分、気圧である通気性材料で被覆することが
望ましい。
以下実施例を掲げて本発明を詳述する。
実施例１〜10および対照例１〜３の原料組成を
表１に示す。
(イ) 試料の作製
外面に不織布と内面にポリプロピレンフイル
ムよりなる有効寸法８cm×12cmの角形扁平な袋
を作製し、直径0.5mmの針孔を袋の両面に開け、
窒素雰囲気下で十分に混合粉砕して得た第１表
に示す実施例および対照例の発熱組成物を60ｇ
ずつ封入し、これを更にガスバリヤー製の外袋
内に封入して試料とした。
(ロ) 発熱性能の測定
試料を外袋より取り出し厚さ18mmの木台上で
試料の下部にはネル１枚を、試料の上部にはネ
ル２枚で保温し、試料下部の中央部の温度を経
時的に測定した。なお外袋より内袋を取り出し
た時刻を基点とし、環境温度20℃で測定した。
(ハ) 試料の経時変化および水素の発生の有無。
試料をガスバリヤー製の外袋内に封入し、40
℃の条件下に置き、30日後に袋の膨張より水素
発生の有無を調べ、また発熱性能を測定し、製
造直後のものと比較した。
(ニ) 使用中の発熱組成物の固まり調査
試料を外袋より出し、下着１枚を介して身体
で使用した時の発熱組成物の固まりを調査し
た。
(ホ) 測定結果
試験結果を第１図及び第１表に示した。
The present invention relates to an improvement in a composition that absorbs oxygen and generates heat when it comes into contact with oxygen. The heat-generating composition of the present invention uses metal iron, which has excellent heat-generating performance, is inexpensive, and is easily available, from among metal powders conventionally used such as metal iron, aluminum, copper, and tin, and uses metal iron as a reaction aid. is the most stable quality among metal halides, easy to use, and economical.
Using sodium chloride, which is highly safe in terms of toxicity,
Moreover, it uses a specific amount of water and sodium silicate hydrate, which has excellent initial heat generation performance, provides stable heat generation over a long period of time, does not solidify the contents during use, and does not generate hydrogen during storage. In addition, the present invention provides a heat-generating composition that has good fluidity and excellent filling efficiency in the manufacturing process. On the other hand, conventional exothermic compositions include metals such as iron and aluminum or sodium sulfide and metal halides, water,
A heat-generating composition is produced by mixing activated carbon, etc., and is used as a chemical body warmer. However, since these conventional devices use only free water, there is a drawback that an excessive amount of water is supplied at the beginning of use, resulting in an abnormally high temperature, or conversely, no heat is generated at all. In addition, although it generates heat initially, when the supply of water becomes insufficient during use, the temperature drops rapidly, and it has the disadvantage that it cannot maintain an appropriate temperature as a stable body warmer. For this reason, the user of the warmer needs to wrap the warmer in cloth etc. to lower the temperature at the beginning of use, and during use, remove the cloth or knead the warmer to promote the reaction of the heat generating composition. . Furthermore, since it contains free water, it is difficult for the entire heat-generating composition to be uniform, resulting in uneven heat generation and the need to mash it during use. In addition, since only free water is used, the water tends to evaporate and the water in the exothermic composition evaporates and is lost during long-term storage of the body warmer, meaning that even if the user uses it, the desired heat generation cannot be achieved. There are also disadvantages that cannot be avoided. Furthermore, if iron and free water coexist, the metal iron will oxidize during long-term storage and hydrogen will be generated, causing expansion and damage to the storage bag, and there is also a risk of ignition and explosion.
Furthermore, in the conventional products, the exothermic composition solidified during use, giving the body a strange feeling. In addition, since the above-mentioned exothermic composition contains a large amount of free water, the powder has poor fluidity and cannot be filled at high speed with an automatic bag-filling machine.
This is extremely inefficient. Heat-generating compositions containing metallic iron, silicic acid and/or hydrated sodium silicate, and metal halides are also known, but these compositions have the drawback of poor initial heat-generating performance. The present inventors conducted research in order to overcome the various drawbacks mentioned above, and as a result, they arrived at the present invention. That is, the present invention provides an exothermic composition comprising (a) metallic iron, (b) sodium chloride, (c) water, and (d) sodium silicate hydrate, which
The respective contents of (c) water and (d) sodium silicate are based on the weight of the exothermic composition, and (c) is 10 to 25
The weight percent (d) is in the range of 0.5 to 15 weight percent. The metal iron used in the present invention is preferably in powder form such as reduced powder, electrolytic powder, spray powder, etc., and is usually smaller than 10 meshes, preferably smaller than 50 meshes. The amount in the exothermic composition,
45-60% by weight, preferably 50-55% by weight. Sodium chloride is preferably 1 to 10% by weight,
The amount of water is preferably 10 to 25% by weight, preferably 15 to 20% by weight. In order to develop the initial exothermic performance of the exothermic composition, it is essential to incorporate a certain amount of free water, and this cannot be completely substituted with crystal water of sodium silicate hydrate. Free water gradually evaporates during storage, so it is necessary to add 10% by weight or more during manufacturing.Additionally, if it is added over 25% by weight, the composition becomes sticky and fluidity decreases, resulting in poor usability and manufacturing. There is a problem with the process. Moreover, various kinds of sodium silicate hydrate salts can be used. For example, Na 2 SiO 3・4H 2 O・Na 2 SiO 3・
Examples include 5H 2 O and Na 2 SiO 3 .9H 2 O, but intermediate hydrated salts thereof may also be used, and the examples are not necessarily limited to those listed here. Sodium silicate hydrate suppresses the generation of hydrogen due to the reaction between metal iron and free water during storage of the composition, gradually releases crystal water after the start of heat generation, maintains a stable temperature, and maintains the content during use. Since it can prevent solidification of substances and reduce the amount of free water, it has good fluidity and has the effect of improving filling efficiency in the manufacturing process. The appropriate amount of the sodium silicate hydrate used in the present invention in the heating element composition is 0.5 to 15% by weight, preferably 1 to 10 parts by weight. If it is less than 0.5% by weight, it will not be possible to completely suppress the generation of hydrogen, and it will be slightly inferior in maintaining a stable temperature during use, and it will not be possible to prevent the contents from solidifying during use. On the other hand, if it exceeds 15% by weight, the initial heat generation of the exothermic composition decreases, which is not preferable. The sodium silicate hydrate salt may be added as a powder by mixing it with the raw materials for other exothermic compositions, or by adding it to water and dissolving it, or adding it to other exothermic compositions while in a suspended state. May be mixed with other raw materials. Furthermore, a filler can be added to the composition of the present invention if necessary. As the filler, inorganic or organic substances that are chemically inert to metallic iron, sodium chloride, and hydrated sodium silicate can be used, and those that are insoluble or sparingly soluble in water are particularly desirable. Activated carbon,
Examples include diatomaceous earth, acid clay, calcium sulfate, and zeolite, with activated carbon and diatomaceous earth being particularly preferred. However, it is not limited to these above. The amount of filler is preferably 10 to 40% by weight, preferably 20 to 30% by weight. Since the exothermic composition of the present invention contains 10 to 25% by weight of free water, the initial exothermic performance of the exothermic composition is extremely excellent, and when the water content of the exothermic composition decreases, crystallization water is naturally released. Due to the action of water in sodium silicate hydrate, which has the property of releasing water, a stable temperature can be maintained, and the exothermic composition does not harden during use, and due to the action of sodium silicate hydrate, it is extremely resistant to changes over time during storage. There is no hydrogen generation, and the hydrogen permeability of ordinary gas barrier packaging materials is such that it does not cause any problems. Furthermore, since the exothermic composition of the present invention has better fluidity than conventional compositions, it can be filled at high speed with an automatic bag making and filling machine, making it an extremely useful invention. In addition, since the exothermic composition of the present invention generates heat simply by contacting with oxygen or air, it can be used as a chemical body warmer,
It can be used as a heat-insulating, cold-protecting, or warming material for the human body, such as a hot compress. However, for these purposes, it is necessary to smoothly generate heat upon contact with oxygen or air, and to control the amount of oxygen or air supplied in order to maintain a predetermined temperature for a certain period of time. The performance of the bag storing the composition of the present invention is as follows: A large number of ventilation holes are provided on one or both sides of the composition, and the ventilation holes are arranged so that the distance between the closest ventilation holes is 3 cm or less. Alternatively, partial ventilation holes are arranged in the center or in a band shape passing through the center on one or both sides, and the oxygen permeability is 0.1 to 5 c.c./
It is desirable to cover it with a breathable material that is permeable to cm 2 , minutes, and atmospheric pressure. The present invention will be described in detail below with reference to Examples. Table 1 shows the raw material compositions of Examples 1 to 10 and Control Examples 1 to 3. (b) Preparation of sample A square flat bag with effective dimensions of 8 cm x 12 cm was made of nonwoven fabric on the outside and polypropylene film on the inside, and needle holes with a diameter of 0.5 mm were punched on both sides of the bag.
60 g of the exothermic compositions of Examples and Control Examples shown in Table 1 obtained by thorough mixing and pulverization in a nitrogen atmosphere.
This was further sealed in an outer bag made of gas barrier and used as a sample. (b) Measurement of heat generation performance Take the sample out of the outer bag and place it on a wooden stand with a thickness of 18 mm.Insulate it with one piece of flannel on the bottom of the sample and two pieces of flannel on the top of the sample, and measure the temperature at the center of the bottom of the sample. was measured over time. The measurements were taken at an environmental temperature of 20°C, starting from the time when the inner bag was removed from the outer bag. (c) Changes in the sample over time and the presence or absence of hydrogen generation. The sample was sealed in an outer bag made of gas barrier, and
After 30 days, the bags were placed under conditions of ℃ and the presence or absence of hydrogen generation was examined by checking the bag's expansion.The heat generation performance was also measured and compared with that immediately after production. (d) Investigation of the clumping of the heat-generating composition during use A sample was taken out of the outer bag, and the clumping of the heat-generating composition when used on the body through a piece of underwear was investigated. (e) Measurement results The test results are shown in Figure 1 and Table 1.
【表】【table】
【表】
＊ 活性炭が発熱組成物の重量を基準にして３％、残
部は木粉
以上の結果から、本発明の発熱組成物、即ち実
施例１，２，３，４，５，６，７，８および９は
使用中の固まりの発生がなく、水素の発生テスト
においても水素の発生が認められなかつた。
又、40℃の温度に30日間保存してその間の変化
を調査したところ、初期の発熱にも全く変化が認
められなかつた。
一方、ケイ酸ナトリウム含水塩が0.5重量部未
満の対照例１では水素の発生が認められ、ケイ酸
ナトリウム含水塩を含まない対照例３，４，５で
は、使用中固まりができ、また水素の発生が認め
られた。
また自由水の量が10重量部以下の対照例６では
初期発熱性能が悪くそして自由水の量が25重量部
以上の対照例７の場合は、組成物がべたつき、ま
た初期発熱性能も悪い。[Table] *Activated carbon is 3% based on the weight of the heat-generating composition, and the remainder is wood flour.From the above results, the heat-generating composition of the present invention, that is, Examples 1, 2, 3, 4, 5, 6, and 7 , 8 and 9 did not form lumps during use, and no hydrogen generation was observed in the hydrogen generation test. Furthermore, when the sample was stored at a temperature of 40°C for 30 days and changes during that time were investigated, no change was observed in the initial heat generation. On the other hand, in Control Example 1 containing less than 0.5 parts by weight of sodium silicate hydrate, generation of hydrogen was observed, and in Control Examples 3, 4, and 5, which did not contain sodium silicate hydrate, agglomeration occurred during use, and hydrogen generation was observed. Occurrence was observed. Further, in the case of Control Example 6, in which the amount of free water was 10 parts by weight or less, the initial heat generation performance was poor, and in the case of Control Example 7, in which the amount of free water was 25 parts by weight or more, the composition was sticky and the initial heat generation performance was also poor.
【図面の簡単な説明】[Brief explanation of drawings]
第１図は本発明の発熱組成物および対照例の試
料を40℃の条件下に30日間置いた後、20℃の条件
下で表面温度を測定した結果である。
FIG. 1 shows the results of measuring the surface temperature of the exothermic composition of the present invention and a control sample at 20°C after being placed at 40°C for 30 days.