High Light Fastness Research Articles

Stimuli-responsive luminescent coumarin thiazole hybrid dye: Synthesis, aggregation induced emission, thermochromism and DFT study

Novel coumarin thiazole hybrid dye with azomethine linkage was synthesized. The dye is very sparingly soluble in DMF and insoluble in other solvents. The dye shows 2 fold increase in emission enhancement on aggregation caused at 60% DMF-H2O mixture. Differential thermal analysis revealed a change from one polymorph to the other polymorph at 285 °C leading to emission in the red region. Excited State Intramolecular Proton Transfer takes place with thiazole nitrogen atom and not with N atom of azomethine linkage contrary to Pigment Yellow 101. High color value (K/S = 10.42) and light fastness (rating = 8) properties were found as compared to Pigment Yellow 101. The computed absorption and emission values were found closer to the experimental values. The pigment exhibits higher first and second order hyperpolarizabilities (24 times more α0, 248 times more β0 and 756 times more γ value than urea).

Preparation and characterization of conductive and antibacterial polyacrylonitrile terpolymer yarns produced by one-step organic coating

In this research work, electrically conductive PAN yarns were produced by coating with copper sulfide and, afterward, evaluated. PAN yarns were treated in a bath containing divalent copper ions, a reducing agent, which is capable of reducing the divalent copper ions to monovalent copper ions and a sulfur-containing compound for sulfidation of copper ions attached to the samples. A pH controlling agent (an organic acid) may be used to enhance the quality of copper sulfide adsorbed by the yarns which, in turn, improves the electrical conductivity of the samples. Using the results obtained from this study, we had to develop appropriate suitable formulation for application and optimization of copper sulfide coating of PAN-based materials. The copper coating of PAN yarns resulted in a reduction of electrical resistivity to 1 × 1010 that of an almost infinite resistance for the untreated yarns. The influence of linear density of the samples on the electrical conductivity and the mechanical properties of the copper-coated PAN yarns were evaluated. Copper-coated PAN yarns displayed very high light fastness and a washing fastness property to multiple washes in terms of electrical conductivity changes. The coating of PAN yarns with copper sulfide confers good antibacterial performance and the antibacterial activity of coated yarns against S. aureus after eight home laundering cycles was not significantly reduced. Results showed that coating PAN samples with copper sulfide can produce samples with good antistatic and antibacterial properties while, at the same time, retaining touch, washability, and other physical properties of the starting samples.

Performance evaluation of various natural agro fibres in carpet making and their costing

The growing concerns for environment and health hazards associated with the use of synthetic dyes, particularly in western countries gave fillip for cultivation and use of naturally coloured cotton, other minor fibres like banana, sisal, hemp etc. The popular belief is that the industrial practices and particularly the chemical industry have altered the natural balance in the world. There is a perception that chemistry is fiddling with the nature. This in turn, leads to returning to traditional or so called more natural way of life. As a part of this trend, there is a lobby for using natural colouring matters today. The reasons for increasing popularity of naturally colorued cotton and other agro fibres include that, these fibres are ecological and economical. In processing of white cotton the chemicals and dyes used and their effluents cause pollution directly or indirectly, the chlorinated products and bleaching agents employed for bleaching cause skin irritation. Dyes containing traces of heavy elements such as arsenic, lead, cadmium, cobalt, zinc and chromium are found skin irritants. The cost of dyeing cotton and other agro fibres economically and environmentally can be very high especially in the counties with strict pollution standards. The cost of naturally coloured cotton is 31 per cent less than the conventionally grown and dyed yarn. Further, the demand for organically produced agricultural products is on the rise. Dyeing uses up to 85 per cent of all the energy used to produce textiles and produces more pollution than any other phase of textile manufacturing. Natural coloured cotton has high quality light and wash fastness, saves resources and prevents pollution. When most textile materials are subjected to continuous rubbing forces, the result is broken threads or holes that we usually associate with wear and abrasion. However, when carpets undergo similar forces, the most obvious results are loss of pile height, gradual flattening of yarns, fuzzing and matting of the pile. Aiming at developing environmentally friendly products, naturally coloured cotton and many other agro fibres were used for making carpets and subjected to some important functional parameters assessed for durability of the newly designed carpets. The results of the study showed that, among the five different types of carpets, compression recovery of naturally coloured cotton carpets was higher followed by cotton carpets. Compression recovery of all the carpets was far less and the carpets did not recover more than 50 per cent. Among the ten different carpets sisal carpets were the costliest followed by banana carpets. The cost of these carpets was high due to cost of raw material i.e. yarn and is not easily available. Naturally coloured carpets were the cheapest or economical among all types of carpets. The cost of production totally depended on the complexity of the design and number of colours used in the design.

Chemical purity and toxicology of pigments used in tattoo inks.

The safety of tattoo inks has obviously increased in Europe since the existence of European Union Resolution ResAP(2008)1, which resulted in the improved quality control of pigment raw materials due to the definition of impurity limits that manufacturers can refer to. High-performance pigments are mostly used in tattoo inks, and these pigments are supposed to be chemically inert and offer high light fastness and low migration in solvents. However, these pigments were not developed or produced for applications involving long-term stay in the dermis or contact with bodily fluids. Therefore, these pigments often do not comply with the purity limits of the resolution; however, it is required that every distributed tattoo ink does not contain aromatic amines and not exceed the limits of heavy metals or polycyclic aromatic hydrocarbons. Current toxicity studies of pigments underline that no ecotoxicological threat to human health or to the environment should be expected. However, the pigment as well as its impurities and coating materials must be considered. In order to evaluate the safety of pigments according to their impurities, two different validated sample preparation methods are necessary: (1) simulation of their long-term stay in the bodily fluid of the dermis and (2) simulation of cleavage due to laser removal or ultraviolet exposure. The development of standardized, validated and well-adapted methods for this application has to be part of prospective efforts. Concerning legislation, it might be appropriate that the first regulative approaches be based on those of cosmetics.

Novel stilbene-triazine symmetrical optical brighteners: synthesis and applications.

A series of new high light fastness, hot pressing fastness optical brighteners was efficiently synthesized by a three-step approach involving the successive replacement of the three chloro groups of 2,4,6-trichloro-1,3,5-triazine under different conditions of temperature and pH. Thus, 2,4,6-trichloro-1,3,5-triazine was treated with different anilines and the resulting dichlorotriazinyl intermediates (3a-I) were further condensed with 4,4-diaminostilbene-2,2'-disulfonic acid to afford bis-monochlorotriazine (5a-I) followed by nucleophilic substitution with ethanolamine to furnish the final hybrid brighteners (7a-I). All of the newly synthesized compounds were characterized by Fourier-Transform Infrared (FT-IR), UV-visible absorption, NMR spectroscopy and the elemental analyses. The synthesized optical brighteners were also assessed for their efficacy as fluorescent brightening agents.

Synthesis and application of novel high light fastness red dyes for ultra high molecular weight polyethylene fibers

A new series of anthraquinoid red dyes were synthesized with 1-amino-2-bromo-4-hydroxyanthraquinone and nalkylphenols to dye UHMWPE fibers with high light fastness. Their dyeability was examined depending on the length of alkyl chains. As the length of alkyl substituents increases, the dyeability toward UHMWPE fibers improves rapidly from methyl to ethyl substituents and maintains almost same level of color strength, and then decreases from heptyl to octyl groups. The color strength of dyeings increased dramatically with the increase of dyeing temperature from 100 °C to 130 °C. The maximum build-up was shown at around 5 % owf dye amount. From the dyeing rate, equilibrium dyeing was achieved at around 5 h at 130 °C. All kinds of fastnesses were good enough showing higher than ratings 4-5 to washing and rubbing for the longer alkyl substituents. Especially, much improvement was achieved in light fastness showing ratings 4, which was higher than ratings 2 of the previous study.

Photoinduced refractive index changes of 3-phenyl-coumarin containing polymers for ophthalmic applications

A novel photorefractive polymer has been developed where 3-phenyl-coumarin (3PC) is attached via alkyl spacers to a methacrylate backbone. The 3PC is a fusion of the structural motives of coumarin and stilbene. In 3PC the E/Z-isomerization, known from stilbenes, is blocked and a more extended conjugated π-electron system than in coumarin is obtained. A methacrylate based polymeric material comprising 3PC in the side chain has been synthesized and its photorefractive properties have been studied. The initial refractive index is n633o=1.613 and the maximal light-induced change of the refractive index was found to be Δn633=−0.045 in spin-coated thin films as well as in bulk material. The glass transition temperature of about 37°C and the high lightfastness of the polymer make it a candidate material for intraocular lenses with photo-tunable refractive index properties.

PREPARATION OF AZO DISPERSE DYES FROM 1,4-DIAMINOBENZENE AND 4- AMINO-3-NITROTOLUENE AND THEIR APPLICATION ON POLYESTER FIBRE USING THE THERMOSOL AND AQUEOUS DYEING METHODS

The preparation and application of azo disperse dyes from 1, 4-diaminobenzene and 4-amino-3- nitrotoluene are described. The azo dye derivatives of these two compounds exhibited very high light fastness on polyester fabric when applied using the Thermosol process in comparison with the aqueous (carrier) dyeing method which gave moderate light fastness. The azo dyes were characterized by elemental, IR and UV analyses. The prepared azo dyes may find application in the dyeing and printing of upholstery materials that may be exposed to long periods of sunlight during usage.

Hydrophobic dye/polymer composite colorants synthesized by miniemulsion solvent evaporation technique

In the present study, the combined miniemulsion and solvent evaporation (MESE) method was employed to encapsulate solvent black B (SOB) dye in poly (methyl methacrylate) (PMMA) to produce dye/polymer composite colorants. Using dynamic light scattering tests, the effect of the formulation variables on the size and size distribution of the prepared nanoparticles was examined. Transmission electron microscopy, UV–visible spectrophotometry, X-ray photoelectron spectroscopy, and elemental analysis results indicate that SOB was successfully encapsulated in the PMMA matrix using the MESE method. The resulting composite colorant could be dispersed in water. It also exhibited high light fastness and water-fastness.

EFFECT OF SURFACTANTS ON KINETICS OF β-CAROTENE PHOTODEGRADATION IN EMULSIONS

The effect of surfactant type on photodegradation kinetics of β-carotene in oil-in-water emulsions has been investigated. The stabilized emulsions of lecithin, sodium stearoyl 2-lactylate (SSL), and polyoxyethylene sorbitan monolaurate (Tween-20) together with a β-carotene solution in corn oil were exposed to illumination. The rate of photochemical degradation was mathematically modeled by regression fitting. The lecithin-stabilized emulsion showed higher light fastness than the other samples. β-carotene photodegradation reaction followed a zero-order kinetic model for oil-based systems and lecithin emulsions, while β-carotene degraded by a first-order reaction in SSL and Tween-20 emulsions. Thermodynamic parameters revealed that water-based samples are more heat sensitive than oil-based samples. An isokinetic relationship was observed between the samples. Moreover, results indicated mixing of SSL and Tween-20 with lecithin leads to better protection of β-carotene than emulsions stabilized with SSL or Tween-20, separately.

UV Screen Printing Ink Consisting of Urethane Diacrylate Oligomer with High Light-fastness

UV Screen Printing Ink Consisting of Urethane Diacrylate Oligomer with High Light-fastness

Synthesis of azo pyridone dyes

Over 50% of all colorants which are used nowdays are azo dyes and pigments, and among them arylazo pyridone dyes (and pigments) have became of interest in last several decades due to the high molar extinction coefficient, and the medium to high light and wet fastness properties. They find application generally as disperse dyes. The importance of disperse dyes increased in the 1970s and 1980s due to the use of polyester and nylon as the main synthetic fibers. Also, disperse dyes were used rapidly since 1970 in inks for the heat-transfer printing of polyester. The main synthetic route for the preparation of azo dyes is coupling reaction between an aromatic diazo compound and a coupling component. Of all dyes manufactured, about 60% are produced by this reaction. Arylazo pyridone dyes can be prepared from pyridone moiety as a coupling component, where substituent can be on nitrogen, and diazonim salts which can be derived from different substituted anilines or other heterocyclic derivatives. In addition, arylazo dyes containing pyridone ring can be prepared from arylazo diketones or arylazo ketoesters (obtained by coupling ?-diketones or ?-ketoesters with diazonim salts) by condensation with cyanoacetamide. Disazo dyes can be prepared by tetrazotizing a dianiline and coupling it with a pyridone or by diazotizing aniline and coupling it with a dipyridone. Trisazo dyes can be also prepared by diazotizing of aniline and coupling it with a tripyridone or by hexazotizing a trianiline and coupling it with a pyridone. The main goal of this paper is to give a brief review on the synthesis of arylazo pyridone dyes due to the lack of such reviews. In addition, some properties of arylazo pyridone dyes as light fastness and azo-hydrazon tautomerism are disccused.

Relationship between photofading and chemical structure of disperse azo dyes on nylon fabric†

The initial rates of photofading for 30 disperse azo dyes on nylon fabric upon exposure to a carbon arc in air have been analysed by formulating a kinetic equation that describes azo scission via the disproportionation reactions and intramolecular H‐transfer by two kinds of hydrazinyl radicals and the conversion of a nitro group to a nitroso group via the disproportionation reaction of nitrosyl hydroxide radicals. The five reaction rate constants are discussed in terms of the heats of reaction by calculating the heats of formation for the reactants, intermediates and products of each reaction using the PM5 method. Phenylazo‐ and thiazoleazo‐N,N‐substituted anilines and phenylazo‐pyridones exhibited large rate constants of multiple terms, while phenylazo‐phenols had the highest light fastness and very small rate constants for the disproportionation reactions of hydrazinyl radicals. Photofading on nylon fabric was primarily controlled by the thermal reactions of photo‐induced monohydrogenated dye radicals, which occurred via one or two primary multiple routes.

Synthesis and application of yellow azo‐anthraquinone disperse dyes for polylactide fibres

1‐Phenyl‐3‐methyl‐5‐pyrazolonyl azo‐anthraquinone dyes having high light fastness on polylactide fibres were synthesised from 1‐aminoanthraquinone via a diazotisation‐coupling reaction with 1‐phenyl‐3‐methyl‐5‐pyrazolones. The structures of these new dyes were confirmed using mass spectrometry, infrared and proton nuclear magnetic resonance spectroscopy and combustion analyses. Their dyeing behaviour on polylactide fibres was also determined, whereupon it was found that the title dyes could be applied at a relatively low dyeing temperature and that the corresponding dyed fabrics had good fastness properties.

High light fastness disazo dyes for inkjet printing

Water-soluble dyes have good solubility, brightness and long shelf life, but higher penetration, poor water and light fastness compare with pigment colorant on printing paper. How to increase light fastness of dyes is always an important issue on inkjet printing for photo. Dye containing carboxyl groups could improve water fastness had been studied but lacked off light fastness information [1,2,3].In this paper, a series of disazo dyes which diazonium group contained carboxyl groups and methoxyl groups included navy blue, red and yellow components were synthesized and evaluated showing good light fastness and high color strength.These diazo compositions form deep black shade and have been approved with high color strength and light fastness performance compared with commercial market product. This range of product is easy dissolved in aqueous and has good printing performance on inkjet application.

Interpretation of the C1s XPS Signal in Copper Phthalocyanine for Organic Photovoltaic Device Applications

AbstractCopper phthalocyanine (CuPc) belongs to a class of small molecules offering particularly interesting advantages when employed in organic electronic devices. Because of its advantageous attributes like high thermal stability, inertness when exposed to acids or alkalis, relatively high electron conductivity, color and light fastness it has been employed in polymer photovoltaic devices as a unipolar dopants complementing the buckminsterfullerene (C60) acceptors and as a conductive buffer. Other organic applications include ambipolar OFETs and non-linear optics structures. X-ray photoelectron spectroscopy (XPS) has been commonly employed to monitor the quality of thin CuPc films. Although XPS analyses of CuPc have been done for over forty years there has not yet been agreement regarding interpretation of the major C1s signal, particularly in the case of non-stoichometric CuPc composition. This work presents systematic studies of the C1s signal of thin film deposits, fabricated using commercially available CuPc materials. It was found that composite C1s CuPc signal consists of five components: two related to the principal C positions within the CuPc macrocycle (C-C in 6-membered ring, C-C-N in 5-membered ring), two associated with shake-up transitions accompanying principal C transitions, and one due to mostly aliphatic impurities. Detailed analysis showed that the magnitude of shake-up peaks was approximately equal 10% to 12% of their principal transitions, in agreement with the theoretical calculations. Correspondingly, the C1s signal originating from the non-CuPc impurities quantitatively agreed with the IR attenuated total reflectance (ATR-IR) measurement of the C-H aliphatic vibrations originating from these impurities present within the CuPc layer. The proposed C1s interpretation has been successfully tested for a large number of commercial CuPc materials and provides a guideline for a routine XPS analysis of the CuPc in organic photovoltaic devices.

Synthesis of novel 1:2 Fe-complexed dye containing polyamine groups

A Fe-complexed dye containing crosslinkable polyamine groups was synthesized through diazotization and coupling reaction, chlorination, amination and metallization. The structure of the Fe-complexed crosslinking dye was characterized by FT-IR and Atomic Absorption Spectroscopic techniques. The dyeing and light fastness properties of the Fe-complex on silk and wool were tested, and the results showed that the novel Fe-complex exhibited both high fixation and good light fastness.

Characterization and Evaluation of the Levelness Parameters of Natural Dyes on Natural Fabrics

The objective of this paper is to establish a quantitative method to determine the levelness (L) of coloration by spectrophotometric measurements. Previously, the L of coloration is mainly evaluated by visual assessment. Hence, we are not able to produce quantitative L data because the visual evaluation of the same colored material obtained from different observers can be quite different. Color levelness is actually a description of the uniformity of color shade in different places of the fabric. It is a very important parameter for the quality of textile coloration, quality control, and communication between laboratories. Thus, this research work evaluates the L parameters by using different variables, including: a) three different natural fabrics; namely, wool, silk and cotton dyed with yellow natural dye from onion skins under the effect of different mordants, and b) three different natural dyes; namely, onion skins, turmeric and madder applied on wool fabric samples under the effect of different mordants. The obtained results show that dyed samples with the highest color strength (K/S) have the highest unlevelness (U) and the lowest color difference (ΔE) values (i.e. the highest light fastness). These results are obtained regardless of the fabric type or dye used.

Novel Black Dye Composition for Inkjet Application

There are certain performance requirements placed on dye-based colorants for inkjet ink applications. These include high color strength and bright shade, long-term storage stability, high light and water fastness. Moreover, metal-free derivatives are preferable from an environmental standpoint. Reactive dyes are intrinsically bright, with moderate fastness properties and are less harmful to human. However, this type of dye has poor long-term storage stability, owing to reactive group hydrolysis. This reaction causes dye precipitation, leading to clogging and damaging to print head and shade changes problems.Dye with carboxyl group have been studied have high water fastness performance [1,2]. In this paper, a series of black dye composition is discussed which navy component contains carboxyl groups and demonstrates improved water and light fastness. These compositions are readily soluble in aqueous solutions shows good printing performance.

インクジェットプリンティング用高耐久性染料の開発と工業的製造法の確立

Water-soluble novel cyan and magenta dyes, which show high light-fastness and ozone-fastness on porous photo media, have been invented for ink jet printing system. Control of dye energy levels, removal of sensitive groups towards ozone, and acceleration of copper-phthalocyanine complex (CuPc) aggregation were the dominant factors to improve both ozone-fastness and light-fastness significantly. For the development of the CuPc cyan skeleton, alkyl sulfonyl groups, all of which were located at beta positions on the CuPc skeleton, were effective to improve fastness. For the development of the magenta skeleton, the combination of aniline-substituted pyridine coupling component and pyrazole diazonium component was inherently important skeleton to improve fastness.Regarding the production process of the novel CuPc dye, solvent effect, control of pH and dehydration reagent such as an orthoester were the dominant parameters to improve cyclization yield. In the novel magenta dye, both introduction of plural functional groups at the same time and development of a highly regioselective reaction for sulfonation were key synthetic processes to establish a successful synthetic route.