Syntheses of polymeric dispersants for pigmented ink‐jet inks

Drop‐on‐demand ink‐jet inks made from dyes usually show poor light fastness and poor water fastness. Therefore, many researchers have introduced pigments into ink‐jet inks to overcome the defects of dye‐based ink. Pigmented ink needs sophisticated technology which disperses the pigments stably in low viscosity. Thus, adequate dispersants are essential to achieve stable dispersions of pigments for ink‐jet inks. This study describes syntheses of dispersants, properties of formulations and comparisons of performance with an existing ink to assess their suitability for commercial application.     

Preparation of pigmented ink‐jet ink by a combination of surface treatments and synthetic dispersant

Drop‐on‐demand ink‐jet inks prepared from dyes usually show inadequate light and water fastness. Thus, in our previous paper, we studied black pigmented ink‐jet inks with the aim of overcoming the drawbacks of dye‐based ink by employing a variety of synthetic dispersants with gas black. In this study, pigmented ink‐jet inks were prepared by a combination of the synthetic dispersant and the surface treatments of a furnace black that is more common than gas blacks. The results of this study show that the surface treatment of the furnace black and the use of the synthetic dispersant are useful in the preparation of ink‐jet inks and endow them with properties that are comparable with those of commercial ink‐jet inks.     

Ink‐jet printing of cotton with natural dyes

Four natural dyes, annatto, cutch, pomegranate fruit rind, and golden dock, were used as colorants for the preparation of water‐based ink‐jet inks for digital textile printing. The physical and rheological properties (pH, conductivity, surface tension, and viscosity) of the inks were measured over a period of 90 days for the evaluation of ink stability and suitability for ink‐jet printing. The inks were found to be suitable and were used for the digital printing of cotton fabrics. The prints were subjected to wash, light, and rub fastness tests and colour measurements. Colour consistency and fastness results, especially after fixation, are comparable with those of synthetic dyes, which paves the way for the production of environmentally friendly ink‐jet inks using natural dyes for the digital printing of cotton through the formulation of suitable printing techniques.     

Disperse ink‐jet inks: properties and application to polyester fibre

Water‐based ink‐jet inks were prepared using press cake samples of two commercially available azo disperse dyes. The suitability of the inks for printing polyester fabric was evaluated via measurement of surface tension, conductivity, viscosity, pH and particle size distribution. Inks prepared by the proposed method fulfill most requirements for an ink‐jet ink depending on the colorant structure, the dispersing agent and the alcohol used. The inks were applied to polyester fabric by both printing and dyeing and the fastness of the ensuing coloured samples was assessed. The fastness properties of the dyed and printed polyester samples were found to be very good to excellent and generally meet accepted customer requirements. Oil‐in‐water microemulsions containing the same colorants were also prepared. Their properties, which are crucial to the suitability for ink‐jet ink, were compared with those of the conventionally prepared inks and were found to be improved, with the exception of conductivity, while surface tension remained within acceptable values.     

Surface-modified and micro-encapsulated pigmented inks for ink jet printing on textile fabrics

Surface-modified and micro-encapsulated pigment dispersions were formulated into pigmented ink jet inks and their properties were analyzed. The changes in viscosity, and particle size distribution, and ink stability were observed every week for 12 weeks at ambient temperature. All the ink jet ink properties were in the operational range. As for appearance and color, the surface-modified pigmented inks printed on a silk fabric yielded higher optical densities, better tone reproduction, wider color gamut, and a larger gamut volume than the micro-encapsulated pigmented inks. For permanence and usability, the micro-encapsulated pigmented inks gave better fastness; the wear comfort of the printed silk fabric, evaluated by the bending stiffness, indicated a negative effect on the pre-treatment of the fabric. Surface pre-treatment of the textile fabrics affected color, appearance, permanence and usability. Despite almost equal numbers of threads, the fabric bending strength in the weft direction was much stronger than that in the warp direction.     

Single‐phase ink‐jet printing onto cotton fabric

The current commercial application of ink‐jet reactive inks to cotton fabrics requires pretreating with pad liquor containing a thickener, urea and alkali prior to printing. In this study, attempts have been made to develop a reactive ink‐jet print in a single‐phase process by adding an organic salt to the ink formulation and hence removing the need to pretreat fabrics. This approach utilises inks containing both a reactive dye, in this case Procion Red H‐E3B, and an organic salt such as sodium formate, sodium acetate, sodium propionate or tri‐sodium citrate. The behaviour of a novel reactive ink formulation for ink‐jet printing on to cotton fabric was evaluated at different pH vlaues. The results at optimum pH indicated that printed non‐pretreated fabrics with ink containing organic salts exhibited a higher level of reactive dye fixation than printed pretreated fabric containing no organic salt ink. The yielded prints demonstrate excellent colour fastness to washing and dry/wet crocking properties. The light fastness of the printed fabrics was improved by adding an organic salt to the ink formulation.     

Synthesis,stability and printing properties of a novel 2‐sulphophenoxy‐4‐chloro‐s‐triazine reactive dye for ink‐jet printing of wool

We report here the synthesis and characterisation of a new medium‐reactivity reactive dye containing 2‐sulphophenoxy‐4‐chloro‐s‐triazine, having enhanced the activity of the chlorine atom for further substitution by the functional groups carried by wool fibre. In addition, a dichloro‐s‐triazine dye was also synthesised for the purpose of comparison. The progress of synthesis reactions and purity of the dyes were determined using capillary electrophoresis and thin layer chromatography. The molecular structure and the chemical compositions of the synthesised dyes were confirmed using Fourier Transform–infrared spectral data and elemental analyses. The inks containing the synthesised dyes were formulated and ink‐jet‐printed onto wool fabrics and then the printed fabrics were steamed at 102°C. Compared with the dichloro‐s‐triazine dye, superior performance in terms of ink stability, K/S and dye fixation was observed for the new 2‐sulphophenoxy‐4‐chloro‐s‐triazine dye. In addition, the light fastness of the fabric printed with the inks containing the new dye was 0.5‐grade greater than that of the fabric printed with the inks containing the dichloro‐s‐triazine dye, and no changes in shade and staining were observed following wash fastness tests of the fabrics printed with the inks containing the new dye.     

水性油墨连接料的新进展

本文综述了水性油墨高分子连接料的发展动态。在环境保护压力的推动下，油墨逐渐向水性化方向发展，水性连接料一直存在着复溶性与耐水性的矛盾，为适应油墨分散介质的改变，连接料从与溶剂型同系物最接近的碱可溶乳液发展为复合型、反应型乳液。水性油墨连接料的许多性能比相应的溶剂型同系物有一定差距，水性高分子结构与性能的研究及在水性油墨中的应用是水性油墨发展的关键。     

喷墨打印机颜料型油墨的最新进展

喷墨打印技术是一种非接触式的数字印刷技术,它将数码技术与传统的印刷技术合二为一。用于喷墨印刷的染料型墨水通常表现出差的耐光性和耐水性,因此将颜料引进到喷墨油墨中以克服染料型墨水的缺点是必然趋势。为了在低粘度下保持颜料稳定的分散,性能优异的合成分散剂对于获得稳定的颜料分散体是必不可少的。本文介绍了水性喷墨油墨的组分及各组分作用,对喷墨油墨的生产技术、发展前景进行了展望。     

Properties of ink‐jet printed,ultraviolet‐cured pigment prints in comparison with screen‐printed,thermo‐cured pigment prints

A collection of printed fabrics for men’s shirts was designed and prepared using computer‐aided design/computer‐aided manufacturing technology. The colours for designs were ink‐jet printed on cotton fabrics with pigments and ultraviolet‐cured. These prints represented the target colours for subsequent flat‐screen printing, which was performed using pigment printing pastes and thermal curing. For an exact transfer of colours of the ink‐jet‐printed standard into the screen‐printing process, a computer recipe prediction method was used. A comparison of colorimetric parameters of fabrics printed with both printing techniques shows minimal and acceptable differences in the CIELab colour values. A comparison of colour fastness properties proves that very good colour fastness is achieved on the pigment‐printed fabrics produced with both printing techniques. The flat‐screen‐printed fabrics show better colour fastness to washing, perspiration and rubbing, while ink‐jet‐printed fabrics show better colour fastness to dry‐cleaning and light. The fabrics printed with both printing techniques have high rigidity and non‐elastic properties. The mechanical and physical parameters are strongly dependent upon the amount of the dry substance of the printing media applied on the cotton fabric surface, which is higher on screen‐printed fabrics. The ink‐jet‐printed fabrics show better air permeability than flat‐screen‐printed fabrics.     

A custom ink‐jet printing system using a novel pretreatment method

A low‐cost and environmental‐friendly direct dye‐based ink‐jet printing system was developed. A novel ink‐jet pretreatment method was employed, in which the cationic fixing agent, Matexil FC‐ER, was applied as the colourless fixing ink and applied only on image areas of the fabric by ink‐jet printer. It was found that this new pretreatment method could more effectively enhance the colour strength and improve the wash fastness (greyscale ≥ 3) when compared with traditional exhaust application. The cross‐staining of non‐image areas of fabric was also apparently decreased using this new method. The light fastness of ink‐jet pretreated samples was slightly reduced as the presence of Matexil FC‐ER made dyes more sensitive to light.     

喷墨打印用墨水的发展现状

本文介绍了喷墨打印用墨水的发展现状，提供了具有优秀色彩输出的墨水配方，从染料结构、溶剂及添加剂等方面提出了提高染料的耐水、耐光牢度及打印品质的方法。     

Pretreatment of silk fabric surface with amino compounds for ink jet printing

This research studied pretreatments of silk fabric with amino compounds for ink jet printing. The pre-treating solutions were serine, glycine, aspartic acid, sericin, chitosan, and a commercial pre-treating chemical called Sanfix 555. Both untreated and treated fabrics were printed with in-house formulated pigmented inks and later steamed to fix the ink on the fabric surface. The pretreatments containing the amino compounds improved hydrophilicity of the silk fabric with the exception of chitosan. The color gamut from sericin, chitosan, and Sanfix 555 pretreatments was wider than that from the amino acid pretreatments. The chroma of the cyan color was most improved. The fabric, after pretreatment with sericin, showed a significant improvement in dry crock fastness while wet crock fastness was improved by serine and glycine. The chitosan slightly improved both dry and wet crock fastness. Wash fastness of all pretreated and printed fabrics including untreated and the printed fabrics was excellent because the pigmented ink was formulated with pigment and binder. Bending stiffness of the silk fabrics after chitosan pretreatment was significantly higher than those with other pretreatments. The ink penetration in sericin and chitosan padded layers was shallower than those for amino acids, enhancing ink deposition on the fabric surface. The amino compound pretreatments held and fixed additional ink on the fabric surfaces resulting in a wider color gamut of the inks.     

Digital and conventional printing and dyeing with the natural dye annatto: optimisation and standardisation processes to meet future demands

The plant colorant annatto was investigated to determine its potential use as a natural dye for conventional and novel textile applications. Alum was selected as a mordant. Different techniques of mordanting and a broad set of variations in the dyeing recipes were applied to achieve optimisation and an improvement in colour fastness properties. Quality control of all dyeings was performed using standard fastness tests and colour measurements. Printing of cotton fabrics was also achieved with annatto using the flatbed screen‐printing technique. Measurement of the rheological and physical properties of the annatto printing paste confirmed its stability and suitability for conventional printing. Fastness properties of the conventionally printed annatto fabric were also measured. A novel water‐based digital printing ink using annatto was prepared and applied to cotton fabric using a digital printing application. The physical properties of the annatto ink‐jet ink were also measured. Wash, light and rub fastness properties of the annatto digitally printed fabric were determined and compared with those of conventional printing methods. The results were promising for annatto as a natural colorant, which possibly paves the way for the development of a new range of natural environmentally friendly dyes.     

Rheological Characterization of Aqueous 3Y‐TZP Inks Optimized for Direct Thermal Ink‐Jet Printing of Ceramic Components

Aqueous 3Y‐TZP inks with solid contents of 22 and 27 vol% were used for fabricating three‐dimensional ceramic components by the direct ink‐jet printing process (DIP). The DIP fabrication was realized using a thermal ink‐jet (TIJ) printing system. Despite the different physical properties of the inks, both inks were successfully ejected and deposited. To define the optimum window of the ink properties required for a stable printing operation, both ceramic inks as well as a typical TIJ ink were characterized in terms of particle size distribution, zeta potential, viscosity, surface tension, and the inverse Ohnesorge number (Oh^?1). Moreover, single drops of all inks were deposited and analyzed by scanning electron microscopy (SEM) to examine the form and integrity of the ejected drops. Demonstration objects (a base with curved channels and a sample molar tooth) were DIP fabricated using both of the ceramic inks. These objects show the potentials of the DIP process for ceramics manufacturing particularly by using TIJ printing systems.     

Syntheses of new black dyes for ink-jet inks

Drop-on-demand ink-jet inks made from dyes generally show poor light and wet fastness. A number of studies have been carried out previously to improve the fastness of such inks by introducing novel dyes and new additives. Based on the research results, use of fast dyes could give ink-jet inks with good properties. This study describes new black dyes for aqueous ink-jet inks, which show better light and wet fastness and print quality, compared to an analogous ink formulated from CI Food Black 2.     

Photorealistic ink‐jet digital printing – factors influencing image quality,image stability and print durability

Digital cameras have now replaced film‐based cameras as the most popular method of still image capture. As a consequence, there has been a rise in growth of the photo‐realistic digital‐printer market as many amateur and professional photographers choose to produce their own hard copy images. The most popular digital printing technology for producing photo‐realistic images is currently drop‐on‐demand ink jet. There has been much research into key factors influencing the quality, stability and durability of images produced using this, and other, digital printing technologies. A key area of study in achieving photo‐realistic images from digital printing systems has been ink‐receivable layers and dye/pigment colorants, and most importantly compatibility between the two. As with any new technology it is important to achieve an acceptable standard of performance and, to this end, research work has been instigated by the International Standards Institute since the mid‐1990s, to achieve a set of standards appertaining to areas such as light fastness, water fastness, thermal stability, humidity fastness and pollution susceptibility. This paper reviews the current state regarding the aforementioned areas with respect to their influence on print quality, stability and durability.     

Green synthesis of reactive dye for ink‐jet printing

Chloropyrimidine‐based reactive dyes are reported as well suited to textile printing; however, nucleophilic aromatic substitution of chloropyrimidines with amino‐containing chromophores is slow and often suffers from poor yields. In this study, a novel and simple method was developed for the synthesis of chloropyrimidine‐based reactive dye under microwave irradiation. In addition, the dye was also synthesised by conventional heating for comparison, which took both the reaction time and yield into account. The progress of the synthesis reactions concerned were monitored using capillary electrophoresis and the purity of the dye obtained was assessed by thin‐layer chromatography. The structure of the synthesised trichloropyrimidine dye was confirmed by Fourier Transform–infrared spectroscopy and elemental analysis. It was found that the reaction rate of the nucleophilic aromatic substitution carried out under microwave irradiation was 4‐fold faster than that carried out under conventional heating, although the enhancement in product yield was modest. These results suggest that microwave irradiation is an effective technique for the synthesis of chloropyrimidine‐based reactive dyes. The synthesised chloropyrimidine dye was formulated into an ink and applied onto a wool fabric by ink‐jet printing. The printed fabrics were steamed at 102°C for 5‐25 minutes at 5‐minute intervals. Good K/S and rate of dye fixation were obtained, both of which improved with increasing steaming time. The prints obtained exhibited reasonably good light and wash fastness properties.     

Titanium dioxide grafted with silane coupling agents and its use in blue light curing ink

To improve the properties of titanium dioxide particles and realise their firm anchorage in blue light curing film, three modified titanium dioxide particles were prepared by grafting 3‐(trimethoxysilyl)propyl methacrylate, 3‐aminopropyltriethoxysilane and hexadecyltrimethoxysilane. The surface changes of titanium dioxide particles after modification were characterised. The dispersion stability, photo‐polymerisation, rheological and mechanical properties of modified titanium dioxide blue light curing inks were investigated. Results showed that compared with native titanium dioxide, modified titanium dioxide particles were more appropriate for blue light curing ink. The particle sizes of the three modified titanium dioxide particles became smaller, their surfaces exhibited hydrophobicity, and the viscosity of the modified titanium dioxide inks decreased slightly. Of the three modified titanium dioxide particles, 3‐(trimethoxysilyl)propyl methacrylate‐ and hexadecyltrimethoxysilane‐modified titanium dioxide particles exhibited better dispersion stability in blue light curing ink. In particular, 3‐(trimethoxysilyl)propyl methacrylate‐modified titanium dioxide blue light curing ink showed the best photo‐polymerisation and mechanical properties, which indicated the participation of the pigment grafted by double bonds in the blue light curable polymerisation. Using modified titanium dioxide in blue light curing ink, the dry/wet rubbing fastness of the printed fabrics improved.     

Ionic liquids as performance additives for water‐based printing inks

For the first time, the use of ionic liquids as additives for printing inks in order to improve the wettability of the printing base by the ink is presented. The aim of this work was to study the influence of ionic liquids on the selected properties of water‐based printing ink and the prints. The contact angles of the printing inks on the printing base were measured. Modified flexographic inks were laboratory printed on polypropylene plastic film. The impact of small amounts of various ionic liquids on printing ink colour was examined in terms of the optical density of the full‐tone area, the colour parameters (L*, a*, b*, CIE), the total colour difference, and the gloss of the dried ink film. The influence of ionic liquids on the ink contact angle, the optical density, and the L*a*b* coordinates is discussed. In general, the investigated ionic liquids improve the wettability of water‐based flexographic printing ink, with an acceptable total colour difference. The optical density is increased for printing inks containing ionic liquids in comparison with the original flexographic printing ink, Process.