JPH04145064A - Method for preventing yellowing of thiourea dioxide - Google Patents
Method for preventing yellowing of thiourea dioxideInfo
- Publication number
- JPH04145064A JPH04145064A JP26641990A JP26641990A JPH04145064A JP H04145064 A JPH04145064 A JP H04145064A JP 26641990 A JP26641990 A JP 26641990A JP 26641990 A JP26641990 A JP 26641990A JP H04145064 A JPH04145064 A JP H04145064A
- Authority
- JP
- Japan
- Prior art keywords
- thiourea dioxide
- thiourea
- reaction
- yellowing
- dioxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- RYYXDZDBXNUPOG-UHFFFAOYSA-N 4,5,6,7-tetrahydro-1,3-benzothiazole-2,6-diamine;dihydrochloride Chemical compound Cl.Cl.C1C(N)CCC2=C1SC(N)=N2 RYYXDZDBXNUPOG-UHFFFAOYSA-N 0.000 title claims abstract description 46
- 238000004383 yellowing Methods 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims description 33
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 29
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 13
- 238000003860 storage Methods 0.000 abstract description 9
- 239000011882 ultra-fine particle Substances 0.000 abstract description 5
- 239000002245 particle Substances 0.000 abstract description 2
- 239000004615 ingredient Substances 0.000 abstract 1
- 238000002156 mixing Methods 0.000 abstract 1
- 230000002265 prevention Effects 0.000 abstract 1
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 description 30
- 238000006243 chemical reaction Methods 0.000 description 27
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 26
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 22
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 15
- 239000006227 byproduct Substances 0.000 description 13
- 239000000243 solution Substances 0.000 description 11
- BWGNESOTFCXPMA-UHFFFAOYSA-N Dihydrogen disulfide Chemical compound SS BWGNESOTFCXPMA-UHFFFAOYSA-N 0.000 description 8
- 239000000047 product Substances 0.000 description 7
- 239000000835 fiber Substances 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 239000003125 aqueous solvent Substances 0.000 description 4
- 239000007795 chemical reaction product Substances 0.000 description 3
- 238000000354 decomposition reaction Methods 0.000 description 3
- -1 first Chemical compound 0.000 description 3
- 230000007774 longterm Effects 0.000 description 3
- 230000001603 reducing effect Effects 0.000 description 3
- 238000007086 side reaction Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- 239000004952 Polyamide Substances 0.000 description 2
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000007844 bleaching agent Substances 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 229920002647 polyamide Polymers 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 2
- 239000000984 vat dye Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- DNIAPMSPPWPWGF-GSVOUGTGSA-N (R)-(-)-Propylene glycol Chemical compound C[C@@H](O)CO DNIAPMSPPWPWGF-GSVOUGTGSA-N 0.000 description 1
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- 102000011782 Keratins Human genes 0.000 description 1
- 108010076876 Keratins Proteins 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 239000002738 chelating agent Substances 0.000 description 1
- 239000012459 cleaning agent Substances 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000000986 disperse dye Substances 0.000 description 1
- 150000002019 disulfides Chemical class 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 230000009965 odorless effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 239000002685 polymerization catalyst Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical group [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 210000001685 thyroid gland Anatomy 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は二酸化チオ尿素の黄変化を防止する方法に関す
るもので、更に詳しくは、貯蔵期間中に二酸化チオ尿素
の黄変化を防止する方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for preventing yellowing of thiourea dioxide, and more particularly, to a method for preventing yellowing of thiourea dioxide during storage. It is something.
（従来の技術とその課！り
二酸化チオ尿素は下記の構造式をとり、酸化性も還元性
も無い、無臭、白色の粉末であるが、水に溶解すると還
元性を有する。(Prior art and its issues!) Thiourea dioxide has the following structural formula and is an odorless, white powder with no oxidizing or reducing properties, but it has reducing properties when dissolved in water.
二酸化チオ尿素は、従来の還元剤の欠点とされている、
貯蔵期間中の不安定性並びに危険性、及び亜硫酸ガスの
発生がなく、使用に際しては、アルカリ性水溶液中で高
い還元電位を有し、更に水溶液中の安定性が優れている
ので、微少量でその使用目的を達成し得る特徴がある。Thiourea dioxide is considered to be a drawback of conventional reducing agents.
There is no instability or danger during storage and no generation of sulfur dioxide gas, and when used, it has a high reduction potential in alkaline aqueous solutions and is excellent in stability in aqueous solutions, so it can be used in very small amounts. It has characteristics that allow it to achieve its purpose.
従って、その用途分野は、バット染料及び硫化バット染
料の染色用還元剤、分散染料で染色した繊維の還元洗浄
剤、ケラチン！！ｌ維の防縮加工剤、蛋白質！１維及び
ポリアミド繊維の漂白剤、ポリアクリロニトリル繊維及
びポリビニールアルコール繊維の製造工程での脱色剤等
の繊維工業分野への応用、並びにパルプの漂白剤、有機
アミンの酸化防止剤、重合触媒、写真工業等その応用分
野は多岐にわたっている。Therefore, its fields of application are reducing agents for dyeing vat dyes and sulfurized vat dyes, reducing cleaning agents for fibers dyed with disperse dyes, keratin! ! l fiber shrink-proofing agent, protein! Applications in the textile industry, such as bleaching agents for polyamide fibers and polyamide fibers, decolorizing agents in the manufacturing process of polyacrylonitrile fibers and polyvinyl alcohol fibers, bleaching agents for pulp, antioxidants for organic amines, polymerization catalysts, and photographs. Its application fields are wide-ranging, including industry.
しかし、二酸化チオ尿素は安定な化合物といえども、長
期間にわたって貯蔵すると、二酸化チオ尿素中に含まれ
る微量の副反応生成物が、徐々に分解して黄色に着色し
、純分の低下を招くと共に商品価値を著しく低下させる
欠点がある。However, even though thiourea dioxide is a stable compound, when stored for a long period of time, trace amounts of side reaction products contained in thiourea dioxide gradually decompose and turn yellow, resulting in a decrease in purity. At the same time, it also has the disadvantage of significantly lowering the product value.
二酸化チオ尿素は工業的に、過酸化水素とチオ尿素の反
応により製造されているが、この反応機構が複雑で、数
多くの副生成物が生成し、この副生成物の二酸化チオ尿
素への混在により黄変化現象が顕在化すると考えられて
いる。Thiourea dioxide is industrially produced by the reaction of hydrogen peroxide and thiourea, but this reaction mechanism is complex and many by-products are produced, and these by-products are mixed into thiourea dioxide. It is believed that this causes the yellowing phenomenon to become apparent.
主たる黄変化の原因物質はジスルフィッドの硫酸塩と考
えられている。ジスルフィッドの硫酸塩の生成は、先ず
、チオ尿素と過酸化水素との反応により生成した二酸化
チオ尿素が、更に過酸化水素と反応し硫酸を副生ずる。The main substance responsible for yellowing is thought to be disulfide sulfate. In the production of disulfide sulfate, first, thiourea dioxide produced by a reaction between thiourea and hydrogen peroxide further reacts with hydrogen peroxide to produce sulfuric acid as a by-product.
この硫酸の生成により反応液のｐＨが低下すると、チオ
尿素の過酸化水素による酸化は二酸化チオ尿素の中間体
であるジスルフィッドで止まり、二酸化チオ尿素まで酸
化されない。ここで生成したジスルフィッドは副生じた
硫酸と反応して、ジスルフィッドの硫酸塩が生成すると
考えられている。When the pH of the reaction solution decreases due to the production of sulfuric acid, the oxidation of thiourea by hydrogen peroxide stops at disulfide, which is an intermediate of thiourea dioxide, and thiourea dioxide is not oxidized. It is thought that the disulfide produced here reacts with the by-produced sulfuric acid to produce a sulfate of disulfide.
二酸化チオ尿素の黄変化を防止する方法として、黄変化
の原因となるジスルフィッドの硫酸塩の含有量の少ない
、高純度の二酸化チオ尿素の製造方法が提案されている
。As a method for preventing yellowing of thiourea dioxide, a method for producing highly purified thiourea dioxide with a low content of disulfide sulfate, which causes yellowing, has been proposed.
例えば反応温度をある一定の範囲内に保つ方法、チオ尿
素と過酸化水素のフィード方法を改良した方法、反応液
中のチオ尿素と過酸化水素のモル比をある一定の範囲内
に管理する方法、反応液のｐＨを保つ方法等である。For example, a method of keeping the reaction temperature within a certain range, a method of improving the feeding method of thiourea and hydrogen peroxide, and a method of controlling the molar ratio of thiourea and hydrogen peroxide in the reaction solution within a certain range. , a method of maintaining the pH of the reaction solution, etc.
これらの方法で使用される溶媒の種類は、非水系溶媒と
水溶媒に大別し得る。The types of solvents used in these methods can be broadly classified into non-aqueous solvents and aqueous solvents.
四塩化炭素、クロロホルム等の塩素系溶媒並びに低級脂
肪族アルコール等の非水系溶媒中で、チオ尿素と過酸化
水素とを反応させて二酸化チオ尿素を製造する方法に関
しては、ドイツ特許第９１７．５５３号、イタリー特許
第５７９．１１９号及びフランス特許第２．０４０．７
９７号で提案されている。German Patent No. 917.553 describes a method for producing thiourea dioxide by reacting thiourea and hydrogen peroxide in a chlorinated solvent such as carbon tetrachloride or chloroform, or a non-aqueous solvent such as a lower aliphatic alcohol. Italian Patent No. 579.119 and French Patent No. 2.040.7
Proposed in No. 97.
これらの方法の場合、チオ尿素と過酸化水素との反応が
不均一系反応であるために副生成物の生成量が多く、又
、この生成した副生成物が溶媒に溶解しないため、製品
二酸化チオ尿素に混入し、製品の黄変化を招く欠点があ
る。In the case of these methods, since the reaction between thiourea and hydrogen peroxide is a heterogeneous reaction, a large amount of by-products are produced, and since the generated by-products are not dissolved in the solvent, the product dioxide It has the disadvantage that it mixes with thiourea and causes yellowing of the product.
一方、水溶媒中で二酸化チオ尿素を製造する場合は原料
であるチオ尿素が水によく溶解し、均一相を形成するの
で副反応生成物の生成量が少な（、比較的純度の高い、
二酸化チオ尿素が得られる利点があり、現在、もっばら
この方法が工業的に採用されており、この方法に関する
改良方法について研究がなされている。On the other hand, when producing thiourea dioxide in an aqueous solvent, the raw material thiourea dissolves well in water and forms a homogeneous phase, so the amount of side reaction products produced is small (relatively pure,
This method has the advantage of yielding thiourea dioxide, and is currently widely used industrially, and research is being conducted to improve this method.
米国特許第２．７８３．２７２号においては、反応液中
の未反応チオ尿素を０５〜１．０％に保ち、反応液のｐ
Ｈを一定範囲内に保ち副反応生成物の生成量を低減する
方法を提案している。In U.S. Pat. No. 2.783.272, unreacted thiourea in the reaction solution is maintained at 0.5% to 1.0%, and the pH of the reaction solution is
We have proposed a method to maintain H within a certain range and reduce the amount of side reaction products produced.
しかし、この方法では二酸化チオ尿素を高純度で製造し
得ない。即ち、チオ尿素と過酸化水素との反応が極めて
早く、且つ多量の反応熱を発生するため、局部での副生
成物の発生は避けられず、この副生成物により二酸化チ
オ尿素の分解が時間と共に進み、硫酸が生成して反応液
のｐＨを低下させ、この反応液のｐＨの低下により副生
成物の１種であるジスルフィッドを生成する。このジス
ルフィッドは副生硫酸と溶解の低い塩を形成し、製品二
酸化チオ尿素に混入して製品純度の低下を招く欠点があ
る。However, this method cannot produce thiourea dioxide with high purity. That is, since the reaction between thiourea and hydrogen peroxide is extremely rapid and generates a large amount of reaction heat, local generation of by-products is unavoidable, and these by-products slow down the decomposition of thiourea dioxide. As the reaction progresses, sulfuric acid is produced and the pH of the reaction solution is lowered, and disulfide, which is a type of by-product, is produced by this decrease in the pH of the reaction solution. This disulfide forms a salt with low solubility with the by-product sulfuric acid, which is mixed into the product thiourea dioxide, resulting in a decrease in product purity.
米国特許第３．３５５．４８６号ではチオ尿素と過酸化
水素の反応時間を７分り内にして、副生成物である硫酸
の生成を出来得る限り少なくし、硫酸が生成する息前に
反応を完結し、反応液のｐＨを３〜７に留める方法を提
案している。しかし反応時間を短くしても、上記の通り
チオ尿素と過酸化水素との反応は極めて早く、且つ多量
の反応熱を発生するため、局部での副生成物の発生は避
けられない。In U.S. Pat. No. 3,355,486, the reaction time of thiourea and hydrogen peroxide is reduced to within 7 minutes to minimize the production of sulfuric acid as a by-product, and the reaction is started before sulfuric acid is produced. The authors propose a method to complete the process and keep the pH of the reaction solution between 3 and 7. However, even if the reaction time is shortened, as mentioned above, the reaction between thiourea and hydrogen peroxide is extremely rapid and generates a large amount of reaction heat, so the generation of by-products locally is unavoidable.
特公昭４５−１７６６５号においては、反応終了後結晶
を分離した反応液をアルカリ土類金属の炭酸塩或は水酸
化物で処理し、反応を阻害する硫酸を除去し、これを次
の反応液として再使用する事を提案しているが、特開昭
５０−６２９３４号の中で、前記特公昭の方法では製品
純度の低下をきたす事を指摘している。In Japanese Patent Publication No. 45-17665, after the completion of the reaction, the reaction solution from which the crystals have been separated is treated with an alkaline earth metal carbonate or hydroxide to remove sulfuric acid that inhibits the reaction, and this is used as the next reaction solution. However, in JP-A-50-62934, it is pointed out that the method of JP-Ko-Sho causes a decrease in product purity.
特公昭５８−３９１５５号においては、チオ尿素と過酸
化水素の反応時に連続的に重炭酸アンモニウムを添加し
て副生する硫酸を中和除去する方法を提案している。こ
の方法は副生ずる硫酸を逐次中和除去するため、反応液
中に硫酸が蓄積する事がな（、二酸化チオ尿素中のジス
ルフィッド硫酸塩による汚染はかなり改善されるが、こ
の方法をもってしても、長期間貯蔵による製品の黄変化
は避けられない。Japanese Patent Publication No. 58-39155 proposes a method of neutralizing and removing by-product sulfuric acid by continuously adding ammonium bicarbonate during the reaction of thiourea and hydrogen peroxide. This method eliminates by-product sulfuric acid by successive neutralization, so there is no accumulation of sulfuric acid in the reaction solution (contamination by disulfide sulfate in thiourea dioxide is considerably improved, but even with this method, , Yellowing of the product due to long-term storage is inevitable.
従って、従来の方法では二酸化チオ尿素の長期間貯蔵に
よる黄変化防止は難しく、不満足な場合が多い。Therefore, with conventional methods, it is difficult to prevent thiourea dioxide from yellowing due to long-term storage, and is often unsatisfactory.
又、特公昭５２−２０９７１号においては、二酸化チオ
尿素にキレート剤を添加することにより、二酸化チオ尿
素の保存期間中の黄変化を防止する方法を提案している
。しかしこの方法においても満足いく黄変化を防止する
ことはできない。Furthermore, Japanese Patent Publication No. 52-20971 proposes a method of preventing thiourea dioxide from yellowing during storage by adding a chelating agent to thiourea dioxide. However, even with this method, yellowing cannot be satisfactorily prevented.
本発明の目的は二酸化チオ尿素のより有効な黄変化防止
法を提供することにある。An object of the present invention is to provide a more effective method for preventing yellowing of thiourea dioxide.
（課題を解決するための手段）
上記した如き従来技術に鑑み本発明者等はチオ尿素と過
酸化水素との反応方法を改善することにより二酸化チオ
尿素の貯蔵期間中の黄変化を防止することば困難と考え
、二酸化チオ尿素に添加剤を添加して黄変化を防止する
方法について種々研究した結果、二酸化チオ尿素に超微
粒子シリカを添加することにより、二酸化チオ尿素のＦ
？蔵蔵開間中黄変化を効果的に防止することができるこ
とを発見した。(Means for Solving the Problems) In view of the prior art as described above, the present inventors have developed a method for preventing yellowing of thiourea dioxide during storage by improving the reaction method between thiourea and hydrogen peroxide. As a result of various research into methods of adding additives to thiourea dioxide to prevent yellowing, we found that by adding ultrafine silica to thiourea dioxide, the F of thiourea dioxide could be prevented.
? It has been discovered that yellowing can be effectively prevented during storage.
即ち本発明は二酸化チオ尿素に超微粒子シリカを添加す
ることを特徴とする二酸化チオ尿素の黄変化防止方法で
ある。That is, the present invention is a method for preventing yellowing of thiourea dioxide, which is characterized by adding ultrafine silica particles to thiourea dioxide.
本発明で用いる超微粒子シリカとしてはハロゲン化珪素
を熱水分解し得られる乾式法の超微粒子シリカと、珪酸
ソーダを酸分解して得られる湿式法の超微粒子シリカ等
がある。超微粒子シリカの平均粒子径は通常２０μ以下
、好ましくは５μ以下である。The ultrafine particle silica used in the present invention includes dry process ultrafine silica obtained by hydrothermal decomposition of silicon halide, and wet process ultrafine silica obtained by acid decomposition of sodium silicate. The average particle diameter of ultrafine silica particles is usually 20 μm or less, preferably 5 μm or less.
超微粒子シリカの添加量は二酸化チオ尿素の重量に対し
て００１〜１０％、好ましくは０．０５〜０５％であり
、通常粉末状の二酸化チオ尿素に超微粒子シリカを添加
し均一に混合する。The amount of ultrafine silica added is 0.01 to 10%, preferably 0.05 to 05%, based on the weight of thiourea dioxide.Ultrafine silica is usually added to powdered thiourea dioxide and mixed uniformly.
かくして得られる二酸化チオ尿素粉末は長期間保存して
も黄変化を顕著に防止することができる。The thus obtained thiourea dioxide powder can significantly prevent yellowing even after long-term storage.
次に実施例を示す。下記の実施例は本発明の態様を示す
ものであって、本発明を限定するものではない。Next, examples will be shown. The following examples are illustrative of embodiments of the invention and are not intended to limit the invention.
（実施例）
下記の表は超微粒子シリカを添加した二酸化チオ尿素を
６ケ月、４０℃で保存し二酸化チオ尿素の白色度及び黄
色着色度を測定した結果を示すものである。(Example) The table below shows the results of storing thiourea dioxide to which ultrafine silica was added at 40° C. for 6 months and measuring the degree of whiteness and yellow coloring of thiourea dioxide.
白色度は熊谷理科工業■製の白色度針（モデルＫＲ−Ｉ
）で、黄色着色度（ｂ値）は日本主色工業■製の色差計
（モデアエロジル−２００：
日本アニロジル■製乾式法超徹粒子ンリカサイロイド−
２４４：
富士デヴイソン化学■製湿式法超微粒子シリカ
上記から微粒子シリカの少量添加により二酸化チオ尿素
の黄色化が効果的に防止されることがわかる。The whiteness is measured using a whiteness needle (model KR-I) manufactured by Kumagai Rika Kogyo ■.
), and the degree of yellow coloration (b value) was measured using a color difference meter (Modeaerosil-200) manufactured by Nippon Shinshoku Kogyo ■: Dry method super-penetration Nrika Thyroid manufactured by Nippon Anilosil ■.
244: Wet method ultrafine particle silica manufactured by Fuji Davison Chemical ■ It can be seen from the above that yellowing of thiourea dioxide can be effectively prevented by adding a small amount of fine particle silica.
Claims (1)
特徴とする二酸化チオ尿素の黄変化防止方法。 ２、超微粒子シリカの添加量が、二酸化チオ尿素の重量
に対し、０．０１〜１．０％である請求項１記載の二酸
化チオ尿素の黄変化防止方法。[Claims] 1. A method for preventing yellowing of thiourea dioxide, which comprises adding ultrafine silica particles to thiourea dioxide. 2. The method for preventing yellowing of thiourea dioxide according to claim 1, wherein the amount of ultrafine silica added is 0.01 to 1.0% based on the weight of thiourea dioxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2266419A JP2984940B2 (en) | 1990-10-05 | 1990-10-05 | Prevention of yellowing of thiourea dioxide. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2266419A JP2984940B2 (en) | 1990-10-05 | 1990-10-05 | Prevention of yellowing of thiourea dioxide. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04145064A true JPH04145064A (en) | 1992-05-19 |
| JP2984940B2 JP2984940B2 (en) | 1999-11-29 |
Family
ID=17430673
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2266419A Expired - Fee Related JP2984940B2 (en) | 1990-10-05 | 1990-10-05 | Prevention of yellowing of thiourea dioxide. |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2984940B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0959175A1 (en) * | 1998-05-20 | 1999-11-24 | Degussa-Hüls Aktiengesellschaft | Compositions comprisisng formamidinesulfinic acid |
| CN106349135A (en) * | 2016-07-29 | 2017-01-25 | 濮阳宏业环保新材料股份有限公司 | Kaolin stabilizer capable of increasing stability of thiourea dioxide and application method of kaolin stabilizer |
-
1990
- 1990-10-05 JP JP2266419A patent/JP2984940B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0959175A1 (en) * | 1998-05-20 | 1999-11-24 | Degussa-Hüls Aktiengesellschaft | Compositions comprisisng formamidinesulfinic acid |
| US6319288B1 (en) | 1998-05-20 | 2001-11-20 | Degussa Ag | Formamidinesulfinic-acid compositions |
| AU748246B2 (en) * | 1998-05-20 | 2002-05-30 | Wego Chemical And Mineral Corp. | Formamidinesulfinic-acid blends II |
| CN106349135A (en) * | 2016-07-29 | 2017-01-25 | 濮阳宏业环保新材料股份有限公司 | Kaolin stabilizer capable of increasing stability of thiourea dioxide and application method of kaolin stabilizer |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2984940B2 (en) | 1999-11-29 |
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