Novel bleach activator compounds derived from the reaction of isocyanic acid with selected nucleophiles

Laundry detergents commonly contain bleach activators that react with the perhydroxy anion produced from perborate or percarbonate anions to form activated peroxy compounds; these enhance bleaching and stain removal capacity especially at lower temperatures, hydrogen peroxide being an inefficient bleach below 60°C. The most commonly used activators are N, N, N′, N′-tetraacetylethylenediamine (TAED) and sodium nonanoyloxybenzenesulphonate (SNOBS) the former being used across Europe whereas the latter is used widely in the United States and Japan. This research studies the preparation of novel activator compounds which are carbamylated derivatives of selected nucleophiles using either solid or aqueous reactions of nucleophilic carboxylate anions with the highly reactive isocyanic acid entity derived from the acidification of sodium cyanate. The novel activator compounds were then assessed as bleach activators by testing against tea and bilberry-stained cotton reference fabrics at 40°C in the presence of hydrogen peroxide at pH values ranging from 4 to 10; bleaching efficiency was assessed visually and colorimetrically. Results showed that all of the synthesised compounds were more effective bleach activators across the pH range tested than the standard TAED system.     

废纸脱墨浆H_2O_2漂白的影响因素

研究了脱墨浆过氧化氢漂白特性。研究结果表明 ,脱墨浆采用过氧化氢漂白时 ,过氧化氢的无效分解的程度大。脱墨浆采用过氧化氢漂白时 ,过氧化氢同氢氧化钠用量比为 1∶0 .6,漂白反应时间为 2h ,漂白反应温度为 70℃ ,浆浓为 1 0 %比较合适     

Two-Stage Peroxide Bleaching of Eucalypt-SGW with Chromium Catalysts

The addition of chromium nitrate to a two-stage hydrogen peroxide bleach of Eucalypt SGW can enhance the brightness of the pulp. It is proposed that radicals produced in the catalytic decomposition of hydrogen peroxide by chromium under acidic conditions participate in reactions which render the chromophores more susceptible to bleaching in the alkaline stage. This two-stage process, under optimised conditions, consumes no more peroxide than a traditional single stage alkaline bleach and allows the pulp to be bleached to a given brightness in a shorter time. Enhanced bleaching response was also observed for a two-stage acid/alkali peroxide bleaching sequence without the addition of chromium, and we have attributed this effect to catalytic effects of transition metal ions which occur naturally in the pulp.     

Strategies to reduce the brightness reversion of industrial ECF bleached Eucalyptus globulus kraft pulp

BACKGROUND: Brightness stability is a key property of bleached chemical pulps and is primarily determined by wood species and bleaching process conditions. Eucalyptus globulus is becoming a very important raw material for hardwood pulp production. In spite of this importance, there is a relative lack of systematic studies in the literature dealing with the subject. This research aims to study the effect of some of the foremost bleaching parameters of a DEDD bleaching sequence as well as the effect of a final P stage (DEDP instead of DEDD) in the brightness stability of bleached E. globulus kraft pulps. RESULTS: The increase of the D₀ stage temperature from 55 °C to 90 °C caused an increase in brightness stability. Increasing the ClO₂ charges from 2.8% to 3.2% also improved significantly the brightness stability. A high H₂SO₄ charge in the D₀ stage (10 kg tonne^?1 pulp) diminished the brightness stability. The combination of H₂O₂ addition to the E stage and ClO₂ reduction in the two final D stages does not affect brightness reversion. Raising the D₂ stage temperature from 65 °C to 82 °C decreased the brightness reversion, while an increase was obtained when the temperature rose above 82 °C. Substitution of the last ClO₂ stage in the DEDD sequence by a H₂O₂ stage (DEDP) significantly reduced the brightness reversion. CONCLUSION: For an existing pulp mill in which the implementation of new technologies to improve brightness reversion is considered, the results obtained showed that brightness stability can be improved without any significant capital investment. Copyright © 2007 Society of Chemical Industry     

An international inter-laboratory trial of the proposed ISO 105-C08 test procedure: a single wash test protocol using a detergent incorporating a lowtemperature bleach activator

A new single wash test procedure, ISO 105-C08, has been developed using a reference detergent, perborate and TAED (a low-temperature bleach activator) in order to better reflect domestic practice. Following an international trial, the procedure has been shown to be fully acceptable for the purpose of inter-laboratory comparisons.     

废报纸脱墨浆甲脒亚磺酸单段漂白工艺研究

主要研究废报纸脱墨浆甲脒亚磺酸(FAS)单段漂白工艺及影响因素,探讨了FAS用量、NaOH用量、温度、时间对纸浆白度的影响。结果表明,废报纸脱墨浆FAS单段漂白的适宜工艺条件为:FAS用量1.4%(对绝干浆),NaOH用量0.7%(对绝干浆),浆浓10%,漂白温度70℃,时间40 min,在此条件下漂后浆白度可达到59%(ISO)。     

漆树漆酶催化甘蔗渣纸浆漂白的研究

利用漆树漆酶在无介体存在条件下对甘蔗渣纸浆进行生物漂白,初步探索了反应时间、漆树漆酶用量、温度及酸度对甘蔗渣纸浆白度的影响。结果表明,在浆浓为3%,漆树漆酶用量1.6 mL/g(对干浆),漂白时间20 min,反应温度20~50℃,pH值为6.1~8.1时,甘蔗渣纸浆白度可提高4%~5%ISO。     

新型洗涤助剂简述——适应环保要求的层状硅酸钠——多功能的漂白活化剂(英文)

4A沸石作为STPP的替代品 ,功能上有一些缺点 ,并在废水处理中有欠缺。层状硅酸盐与洗衣粉中的其他成分相容性很好 ,并显示出杰出的有效性。层状硅酸钠可以在下水道中水解 ,释放出硅酸和钠离子而不会造成固体沉积。主要用于粉状洗涤剂的层状硅酸钠有望扩大其应用领域。基于它能够使玻璃免受腐蚀的杰出能力 ,它还可以用做自动洗碗机洗涤粉中的多功能原料。过硼酸钠的有效性和合理的价格使其成为粉状洗涤剂中一广为应用的原料。由于过硼酸钠在低温下活性较低 ,而现代的许多纤维要求较低的洗涤温度。一些研究者试图用其他活性氧化物如过碳酸钠代替过硼酸钠 ,而另一些研究者则建议用金属螯合剂作为过硼酸钠的催化剂。这两种方法都未能真正有效。第三种方法 ,是通过使用第二种化学物质与过硼酸钠形成中间体 ,而降低其分解所需的较高的活化能 ,已被证明是有效的。在各种化合物中 ,TAED (四乙酰基乙二胺 )赢得了最大的市场。TAED在 1999年的消费量已达至 75 0 0 0t。TAED不仅被用于纺织品洗涤剂中 ,也用于自动洗碗机洗涤剂、清洁剂以及其他产品中。TAED的主要作用是作漂白活化剂 ,它的辅助作用消毒和去味作用将使其仍保持市场的领导地位     

废报纸脱墨浆两段漂白工艺研究

研究了废报纸脱墨浆过氧化氢―过氧化氢(PP)、过氧化氢―甲脒亚磺酸(PF)两段漂白工艺。结果表明,废报纸脱墨浆PP漂白中第二段过氧化氢漂白的适宜工艺条件为:浆浓20%,漂白时间2.5 h,温度60℃,乙二胺四乙酸(EDTA)用量0.2%,硫酸镁用量0.05%,硅酸钠用量0.5%,过氧化氢用量4%,氢氧化钠用量0.5%,漂后浆白度71.5%(ISO);PF漂白中第二段甲脒亚磺酸漂白的适宜工艺条件为:漂白温度60℃,漂白时间40 min,浆浓10%,甲脒亚磺酸(FAS)用量1.6%,NaOH用量0.8%,漂后浆白度68%(ISO)。     

非硅过氧化氢稳定剂在桉木TMP浆漂白过程中的应用研究

以桉木热磨机械浆(TMP浆)为研究对象, 探讨了非硅过氧化氢漂白稳定剂G1、G56替代硅酸钠用于桉木TMP浆漂白的可行性, 并对漂白工艺条件进行了优化。结果表明:桉木TMP浆过氧化氢漂白采用稳定剂G1、G56替代硅酸钠是可行的。在浆浓(质量分数)20%、H₂O₂用量9.0%(以绝干浆质量计,下同)条件下优化的漂白工艺条件为:G1用量0.5%, G56用量0.5%, NaOH用量5.85%, 温度90 ℃和时间30 min。在此工艺条件下桉木TMP浆单段过氧化氢漂白后, 浆的白度达到77.47% (ISO), 比原浆白度高38.89个百分点, 比2%硅酸钠用量下漂后浆的白度高1.75个百分点, 与2%硅酸钠和2%DTPA同时用作稳定剂的白度(79.88%(ISO))相当。     

过硼酸钠漂白剂研究进展

论述了四水合过硼酸钠单水合过硼酸钠和液态过硼酸钠等3种形态产品的性能特点及制备方法，以及漂白激活剂的研究进展。     

洗衣用漂白剂和漂白活化剂的研究进展

介绍了织物漂白剂的原理。论述了活化剂对过氧盐的激活机理和漂白活化的研究进展。     

Synthesis of N‐[4‐(dimethylalkylammoniomethyl) benzoyl]caprolactam chlorides as cationic bleach activators for low‐temperature bleaching of cotton fabric under near‐neutral pH conditions

Low‐temperature bleaching of cotton fabric can be achieved by incorporating a so‐called bleach activator into an aqueous solution of hydrogen peroxide. In this study, a series of N‐[4‐(dimethylalkylammoniomethyl)benzoyl]caprolactam chlorides were synthesised for use as cationic bleach activators with various alkyl chain lengths. All these synthesised cationic bleach activators were confirmed by ¹H and ¹³C nuclear magnetic resonance spectroscopy and mass spectroscopy. Bleaching experiments revealed that these synthesised bleach activators were effective for bleaching of cotton fabric at 50 °C under near‐neutral pH conditions, but the alkyl chain lengths had a great influence on their bleaching performance. Increasing the alkyl chain length from 2 to 6 carbon atoms could slightly enhance bleaching performance, while increasing the alkyl chain length from 8 to 16 carbon atoms markedly reduced bleaching performance.     

Enhanced PAA bleaching of cotton by incorporating a cationic bleach activator

Peracetic acid is a well-known alternative to hydrogen peroxide as a bleaching agent for cotton. In this study, a novel cationic bleach activator, N -[4-(triethylammoniomethyl)benzoyl]butyrolactam chloride, was used in combination with peracetic acid to investigate the enhancement of cotton bleaching efficiency. The effects of temperature, pH and concentrations of activator and peracetic acid on the bleaching performance were studied using a statistical design of experiment. Adding activator to a peracetic acid bleaching bath improved the resultant whiteness of the substrate and at optimal conditions produced less fibre damage than when peracetic acid was used alone. In addition, the bleaching performance of both peracetic acid and hydrogen peroxide in the presence of activator was compared. In the absence of activator, the peracetic acid performance was considerably superior to a conventional hydrogen peroxide bleach system in which no bleach activator is present. However, addition of activator to the hydrogen peroxide bath increased the whiteness to a level comparable to peracetic acid.     

TCF BLEACHED PULPS FROM MISCANTHUS SINENSIS BY THE IMPREGNATION RAPID STEAM PULPING (IRSP) PROCESS

ABSTRACT

The production of bleached cellulose pulps from elephant grass (Miscanthus sinensis) via a two-stage soda pulping process and a TCF bleaching sequence is evaluated in this work. The impregnation rapid steam pulping process (IRSP) involves impregnating of the lignocellulosic material with the pulping liquor, withdrawing the excess liquor and rapidly steaming the impregnated material at 180–200°C for a short time. In this paper the process variables and their effect on the kappa number, yield and viscosity of the unbleached pulps are discussed. Bleaching by an ozone-based TCF sequence was tested, and the papermaking properties of the bleached pulp were determined. A kappa number of 19 was obtained by impregnating at an alkali charge of 30 + 0.1% anthraquinone carboxylic acid (AQCA) and pulping at 180°C for only 15 min. Kappa was reduced to 16 by extending pulping time to 26 min. The alkali consumption during impregnation and pulping was 10.2 g NaOH/100 g of dry Miscanthus. Screened pulp yield, viscosity and brightness for this pulp were 54.6%, 913 mL/g and 37.3%, respectively. After bleaching, the pulp had an ISO brightness of 87.4% and a viscosity of 700 mL/g. Refining in a PFI mill provided optimal strength properties of the bleached pulp at 4500 revolutions (71°SR): breaking length 7.2 km, tensile index 72 N m/g, and burst index 4.3 kN/g. Tear index was 7.9 mN m²/g at this degree of refining.     

Synthesis of novel bleaching catalyst containing macrocyclic manganese complexes and potential applications in laundry detergent

A bleaching catalyst based on manganese complexes, consisting of meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane and racemic-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane ligands, was synthesized and applied at 25°C to cotton fabrics stained with tea, coffee, curry, and sugar beet to examine the bleaching properties. The bleaching performance of this novel catalyst was higher than that of the conventional activator, tetraacetyl ethylenediamine (TAED). Dye and fabric damage were also examined for six differently dyed test fabrics under stressed conditions over 30 wash cycles. The dye damage induced by the catalyst was significantly less than that induced by TAED in direct black 22, reactive blue 225, reactive red 158, and sulfur blue 19. Tensile strength loss measurement, which represents fabric damage, showed less damage for the catalyst in direct black 22, direct blue 71, reactive red 158, and sulfur blue 19. The results indicate that this new bleaching catalyst could potentially be employed for low-temperature bleaching.     

MgO替代NaOH的杨木PRC-APMP过氧化氢漂白

针对NaOH作为碱源的预处理盘磨化学处理碱性过氧化氢机械浆(PRC-APMP)漂白过程中存在的一些问题,考察了使用MgO在二段化学预浸段和高浓停留段以不同比例替代NaOH进行漂白后对浆张白度、抗张指数以及漂后废液中化学需氧量(CODCr)含量的影响。实验结果表明:在杨木PRC-APMP过氧化氢漂白过程中采用不同比例的MgO替代NaOH,漂后的浆张白度与未替代相比变化不大;抗张指数随替代比例的增加呈下降趋势;二段化学预浸段和高浓停留段废液中CODCr含量随MgO替代NaOH比例的增加呈下降趋势。     

Combination of Surfactant Action with Peroxide Activation for Room-Temperature Cleaning of Textiles

Room-temperature cleaning of textiles is commonly practiced in many countries for energy saving as well as custom in daily life, but not very effective for removing colored contaminants. In this work, it was proposed to combine surfactant action (SA) with peroxide activation (PA) in a peroxide activator to enable cleaning of textiles at room temperature. N-[4-(alkyldimethylammoniomethyl)benzoyl]lactam chloride was designed and synthesized as a prototype of the proposed peroxide activator, in which the alkyl chain with a carbon atom number of n was responsible for surfactant action and the N-benzoyllactam with a carbon atom number of m in the lactam ring was responsible for peroxide activation. Such a peroxide activator was hereby referred to as SAPA_m-n. The room-temperature cleaning performance of SAPA_m-n was examined by cotton fabrics contaminated with morin and waste engine oil, respectively. It was found that SAPA_m-n was able to activate hydrogen peroxide released from sodium perborate so as to effectively bleach the morin-contaminated cotton fabric at room temperature. Though extending the alkyl chain length of SAPA_m-n resulted in no apparent effect on the room-temperature bleaching performance, it enhanced the surfactant action which contributed to removing oily contaminants from textiles. Color-safe performance of SAPA_m-n was evaluated by cleaning a dyed cotton fabric at room temperature. It was found that the peroxide bleach activated by SAPA_m-n resulted in no apparent color change of the dyed cotton fabric. The results of this study provide new insights on textile cleaning at room temperature for the purpose of energy saving.     

Bleaching of cotton with activated peroxide systems

The bleaching performance of a novel cationic bleach activator, N -[4-(triethylammoniomethyl)benzoyl]-caprolactam chloride, was compared to that of nonanoyloxybenzene sulphonate, a commercially available anionic bleach activator. The whiteness of bleached cotton fabric was used as a measure of the performance. Comparison of bleach performance and the effect of key variables were evaluated using a central composite experimental design. The performances of both activators increased with temperature and sodium hydroxide concentration. Also, the performance of the cationic bleach activator increased with activator concentration, while an increase in the concentration of nonanoyloxybenzene sulphonate gave an adverse effect on the performance. It was found that the cationic bleach activator was superior to the anionic activator in the hot bleaching of cotton under the conditions studied.     

Terpyridine-manganese complexes: A new class of bleach catalysts for detergent applications

Oxidation catalysis is one approach used to improve the performance of hydrogen peroxide in laundry bleach applications. We introduce herein a new class of bleach catalysts based on the ligand 2,2′∶6′,2″ terpyridine. A set of manganese complexes of substituted terpyridines was investigated with respect to their physicochemical properties and bleach performance. Introduction of electron-donating hydroxy and amine substituents in the 4-position of the individual pyridine rings improves the bleach performance in model experiments with morin (2′,3,4′,5,7-pentahydroxyflavone) in solution as well as on tea-stained cotton fabrics. All the catalysts show excellent bleach performance at 40 and 25°C under European washing conditions. Performance is superior to that of the activator tetraacetyl ethylenediamine (TAED) but depends critically on the substitution pattern. Dye damage caused by the catalysts is similar to that of TAED, proving that catalytic bleach systems with high performance and low damage are indeed feasible. Model experiments revealed that the complexes are highly stable under aqueous alkaline conditions in the presence of hydrogen peroxide. The optimal pH for catalytic activity is about 10. For a catalyst to have a high bleach performance, it must possess a sufficiently low activity to catalyze disproportionation of hydrogen peroxide, which is a major side reaction of catalytic bleach with manganese complexes. All the catalysts showed a similar affinity for the cotton fabric, suggesting that differences in bleach activity of complexes are not caused by differences in the fabric affinity.