JP2004217453A

JP2004217453A - Calcium hypochlorite composition and method of manufacturing the same

Info

Publication number: JP2004217453A
Application number: JP2003005196A
Authority: JP
Inventors: Toshiyuki Yamashita; 敏幸山下; Kazumasa Takizawa; 一誠滝沢; Shoji Maruyama; 昭司丸山
Original assignee: Nippon Soda Co Ltd
Current assignee: Nippon Soda Co Ltd
Priority date: 2003-01-14
Filing date: 2003-01-14
Publication date: 2004-08-05

Abstract

<P>PROBLEM TO BE SOLVED: To provide a calcium hypochlorite composition having excellent preservation stability and capable of being safely handled. <P>SOLUTION: The substantially uniform calcium hypochlorite composition containing ≥50 wt.% Ca(OCl)<SB>2</SB>and 10-15 wt.% water is manufactured by separating a crystal from calcium hypochlorite reaction mother liquor and after pellelizing, drying. The composition attains the objective. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【発明の属する技術分野】
本発明は、安全性が高くしかも安定性に優れた次亜塩素酸カルシウム組成物及びその製造方法に関する。
【従来技術】
Ｃａ（ＯＣｌ）_２を５０重量％以上含有する次亜塩素酸カルシウム組成物はプール等の殺菌に大量に使用されている。しかし次亜塩素酸カルシウムは強力な酸化剤であり、その取り扱いを誤ると非常に危険なものである。そのため安全性を高めるため、種々の工夫がなされている。例えば、特公昭４８−３０７７号公報には、含水率が約４〜１５重量％の組成物が提案されている。又、特開昭５２−１１１４９７号公報には含水率が１６〜２２重量％の組成物と２重量％以下の組成物とを混合して含水率が５〜１１．５重量％の組成物を得ている。しかし前者は実質的に無水の次亜塩素酸カルシウム組成物に水を添加する方法で製造しているため、完全に均一な含水率になるとは限らない。また、一部水分が付着水として残存するため保存安定性の面で問題が残る。一方、後者は水分のほとんど結晶水として存在するため混合しても両者の含水率は変化せず、水分が２重量％以下の次亜塩素酸カルシウム組成物はそのまま存在し、高温にさらされたり外部から点火されるとこの実質的に無水の組成物を通して急激に連鎖的分解を起こす危険性があった。
【発明が解決しようとする課題】
本発明の目的は、安全性が高くしかも安定な次亜塩素酸カルシウム組成物を提供することである。
【課題を解決するための手段】
本発明は（１）Ｃａ（ＯＣｌ）_２を５０重量％以上含有し、かつ含水率がを１０〜１５重量％であることを特徴とする実質的に均一な次亜塩素酸カルシウム組成物（請求項１）、（２）次亜塩素酸カルシウム反応母液から結晶を分離し、造粒した後乾燥させることを特徴とするＣａ（ＯＣｌ）_２を５０重量％以上含有し、かつ含水率を１０〜１５重量％である実質的に均一な次亜塩素酸カルシウム組成物の製造方法（請求項２）、（３）次亜塩素酸カルシウム反応母液から結晶を分離した後、含水率が１６〜２５重量％になるまで乾燥させ、圧延造粒し、更に乾燥させる請求項２記載の製造方法（請求項３）、気流乾燥により含水率が１６〜２５重量％になるまで乾燥させる請求項２または３記載の製造方法（請求項４）次亜塩素酸カルシウム反応母液から結晶を分離し、押出し造粒した後乾燥させる請求項２記載の製造方法（請求項５）である。
【発明の実施の形態】
本発明に用いる反応母液は特に制限はなく通常の製法で製造した次亜塩素酸カルシウムの母液が使用出来る。結晶を分離する方法も特に制限はなく、遠心分離機等を使用してろ過を行えば良い。分離された結晶は通常３０〜４０重量％の水分を含んでいる。この結晶を造粒、乾燥して目的の次亜塩素酸カルシウム組成物を得るが、造粒を押出し造粒で行う場合は、この水分を３０〜４０重量％含有している結晶をそのまま造粒し、含水率が１０〜１５重量％になるまで乾燥させ目的物を得る。乾燥方法も特に制限はないが流動乾燥機等を使用して乾燥させるのが好ましい。造粒を圧延造粒で行う場合は、造粒時の含水率を１６〜２５重量％に制御することにより圧延造粒を効率的に行うことが出来るため、乾燥を２段に分けて行うことが好ましく、含水率３０〜４０重量％の結晶を含水率が一旦１６〜２５重量％になるまで乾燥させた後、造粒し更に乾燥させることにより目的の顆粒の次亜塩素酸カルシウム組成物を得ることができる。この方法においても乾燥方法に特に制限はないが、第１段の乾燥は気流乾燥が、第２段の乾燥は流動乾燥が好ましい。第２段の乾燥を流動乾燥で行った場合、含水率の低下を防ぐため、乾燥後、速やかに冷却することが好ましい。製品は顆粒状でありその粒径に特に制限はないが、通常０．３〜３．０ｍｍくらいである。また粒径を揃える場合は篩等をを用いることにより思い通りの粒径の製品をえることが出来る。
【実施例】
次に実施例、試験例を挙げ本発明を更に説明する。
実施例１
製品中の有効塩素濃度が７０％となるように調製された反応母液（次亜塩素酸カルシウム粗結晶を５〜６重量％含有）を遠心分離機で振り切り含水率が３５重量％の粗結晶を得た。この結晶を風量４８０ｍ／分の気流管内に９０〜１２０ｋｇ／分の割合で供給し、気流管入口の気流温度を８０〜９０℃に制御することにより含水率２４％の結晶を得た。この結晶を２軸ローラーで圧延した板状物を解砕しながら金網に擦り付けて整粒した。（金網の目開き３．２ｍｍ）この整粒した造粒物を乾燥用流動乾燥機に導入し、１００〜１１５℃のエアを流動乾燥機内に吹き込んで乾燥させた後、更に冷却用流動乾燥機に移して１５〜２０℃のエアを流動乾燥機内に吹き込んで冷却し、含水率１５重量％の次亜塩素酸カルシウム組成物を得た。この結晶を振動篩８メッシュＰＡＳＳ，４０メッシュＯＮで篩い分けして製品を得た。同様の方法で水含水率１０重量％、比較例として含水率量９重量％、５重量％及び１重量％のものを得た。
安全性試験
上記製造した次亜塩素酸カルシウムを用い、以下の試験を行った。結果を第１表に示す。
試験方法
▲１▼幅１０ｃｍ長さ５０ｃｍのブリキ板を折角９０度で縦長に折り曲げたＶ字型の桶を水平に設置
▲２▼含水率が異なる種々の次亜塩素酸カルシウム２００ｇを上記Ｖ字型桶に充填（充填にあたっては、長さ３０ｃｍと定め、桶の谷に水平になるように充填）
▲３▼充填した次亜塩素酸カルシウムの末端にマッチで添加
▲４▼分解が伝播するか否か及びその状況を観察

【発明の効果】
本発明の組成物は、上記安全性の試験からも明らかなように非常に安全で取り扱いが楽であるばかりでなく、安定であるので長期の保存に耐えるため、船等による海上輸送可能な組成物である。
【図面の簡単な説明】
【図１】第１図は、安全性試験に使用した装置の略図である。TECHNICAL FIELD OF THE INVENTION
The present invention relates to a calcium hypochlorite composition having high safety and excellent stability, and a method for producing the same.
[Prior art]
Calcium hypochlorite compositions containing 50% by weight or more of Ca (OCl) ₂ are used in large quantities for sterilizing pools and the like. However, calcium hypochlorite is a powerful oxidizing agent and is very dangerous if mishandled. Therefore, various devices have been devised to enhance safety. For example, Japanese Patent Publication No. 48-3077 proposes a composition having a water content of about 4 to 15% by weight. JP-A-52-111497 discloses that a composition having a water content of 5 to 11.5% by weight is mixed with a composition having a water content of 16 to 22% by weight and a composition having a water content of 2% by weight or less. It has gained. However, since the former is manufactured by adding water to a substantially anhydrous calcium hypochlorite composition, the water content is not always completely uniform. Further, a problem remains in terms of storage stability because a part of water remains as attached water. On the other hand, the latter contains almost no water as crystallization water, so that even if mixed, the water content of both does not change, and the calcium hypochlorite composition having a water content of 2% by weight or less exists as it is and is exposed to high temperatures. There was a risk of rapid chain degradation through this substantially anhydrous composition when ignited from the outside.
[Problems to be solved by the invention]
An object of the present invention is to provide a highly safe and stable calcium hypochlorite composition.
[Means for Solving the Problems]
The present invention provides (1) a substantially uniform calcium hypochlorite composition comprising Ca (OCl) _{2 in an amount} of 50% by weight or more and a water content of 10 to 15% by weight. Item 1), (2) Ca (OCl) ₂ characterized in that crystals are separated from the calcium hypochlorite reaction mother liquor, granulated and then dried, and contain 50% by weight or more and a water content of 10 to 10. A method for producing a substantially uniform calcium hypochlorite composition of 15% by weight (Claim 2), (3) after separating crystals from the calcium hypochlorite reaction mother liquor, the water content is 16 to 25% by weight. %, Dried and granulated, and further dried. 4. The method according to claim 2, wherein the water content is reduced to 16 to 25% by weight by flash drying. Method of producing (claim 4) calcium hypochlorite The crystals were separated from the beam reaction mother liquor, is a manufacturing method of claim 2, wherein the drying after extrusion granulation (claim 5).
BEST MODE FOR CARRYING OUT THE INVENTION
The reaction mother liquor used in the present invention is not particularly limited, and a calcium hypochlorite mother liquor produced by a usual production method can be used. The method for separating the crystals is not particularly limited, and the filtration may be performed using a centrifuge or the like. The separated crystals usually contain 30 to 40% by weight of water. The crystals are granulated and dried to obtain the desired calcium hypochlorite composition. However, when the granulation is performed by extrusion granulation, the crystals containing 30 to 40% by weight of the water are granulated as they are. Then, drying is performed until the water content becomes 10 to 15% by weight to obtain the desired product. The drying method is not particularly limited, but it is preferable to use a fluidized drier or the like. When the granulation is performed by rolling granulation, since the rolling granulation can be efficiently performed by controlling the water content at the time of granulation to 16 to 25% by weight, the drying is performed in two stages. Preferably, the crystals having a water content of 30 to 40% by weight are dried until the water content is once 16 to 25% by weight, then granulated and further dried to obtain the desired calcium hypochlorite composition of the granules. Obtainable. Although there is no particular limitation on the drying method in this method as well, flash drying is preferred for the first stage drying and fluidized drying is preferred for the second stage drying. When the second stage of drying is carried out by fluidized drying, it is preferable to cool immediately after drying in order to prevent a decrease in water content. The product is granular and its particle size is not particularly limited, but is usually about 0.3 to 3.0 mm. When the particle size is uniformed, a product having a desired particle size can be obtained by using a sieve or the like.
【Example】
Next, the present invention will be further described with reference to Examples and Test Examples.
Example 1
The reaction mother liquor (containing 5 to 6% by weight of calcium hypochlorite crude crystals) prepared so that the effective chlorine concentration in the product becomes 70% is shaken off by a centrifugal separator to remove the crude crystals having a water content of 35% by weight. Obtained. The crystals were supplied into an air flow pipe at a flow rate of 480 m / min at a rate of 90 to 120 kg / min, and the air flow temperature at the inlet of the air flow pipe was controlled at 80 to 90 ° C. to obtain crystals having a water content of 24%. The crystal was crushed by a biaxial roller to crush a plate-like material and rubbed against a wire net to regulate the size. (Aperture of wire mesh: 3.2 mm) The sized granules are introduced into a fluidizing dryer for drying, and air at 100 to 115 ° C is blown into the fluidizing dryer to be dried. Then, air at 15 to 20 ° C. was blown into the fluidized dryer to cool the product, and a calcium hypochlorite composition having a water content of 15% by weight was obtained. The crystals were sieved with a vibrating sieve 8 mesh PASS, 40 mesh ON to obtain a product. Water content of 10% by weight and water content of 9% by weight, 5% by weight and 1% by weight as comparative examples were obtained in the same manner.
Safety test The following test was performed using the calcium hypochlorite produced above. The results are shown in Table 1.
Test method (1) A V-shaped tub obtained by bending a tin plate of 10 cm in width and 50 cm in length vertically at a bending angle of 90 degrees is installed horizontally. (2) 200 g of various calcium hypochlorites having different water contents are V-shaped. Filling the tub (when filling, set the length to 30cm and fill the valley horizontally)
(3) Matching addition to the end of the filled calcium hypochlorite (4) Observation of whether or not decomposition propagates and its condition

【The invention's effect】
The composition of the present invention is not only very safe and easy to handle as evident from the above safety test, but also stable and can withstand long-term storage, so that it can be transported by sea, such as by ship. Things.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an apparatus used for a safety test.

Claims

A substantially uniform calcium hypochlorite composition comprising at least 50% by weight of Ca (OCl) ₂ and having a water content of 10 to 15% by weight.

The crystals are separated from the calcium hypochlorite-reacted mother liquor, granulated, and then dried, containing substantially 50% by weight or more of Ca (OCl) ₂ and having a water content of 10 to 15% by weight. A method for producing a calcium hypochlorite composition which is uniformly uniform.

3. The method according to claim 2, wherein the crystals are separated from the calcium hypochlorite reaction mother liquor, dried until the water content becomes 16 to 25% by weight, roll-granulated, and further dried.

The method according to claim 2 or 3, wherein drying is performed by flash drying until the water content becomes 16 to 25% by weight.

3. The method according to claim 2, wherein the crystals are separated from the calcium hypochlorite reaction mother liquor, extruded, granulated and dried.