Synthesising polymeric dispersants to apply to carbon black pigmented mill bases for use in ink‐jet inks

Dyes are an important component of drop‐on‐demand ink‐jet inks and are commonly used in desktop printers. While they offer bright, vivid colour, these dyes exhibit poor light and water fastness. To combat this, researchers have started using pigmented ink‐jet inks instead of dye‐based inks to improve light and water fastness, but the pigments are insoluble in ink vehicles. To use pigments, dispersants must be applied; however, this is a delicate process because the properties of the dispersant substantially affect how the pigmented mill base must be prepared. In this study, polymeric dispersants are synthesised based on the properties and ratios of monomers and the molecular weights of polymers. In total, 14 types of polymeric dispersants are synthesised and examined, with special attention paid to the dispersing properties of particle size reduction and the stability of the pigmented mill base used to prepare drop‐on‐demand ink‐jet inks. This study describes the synthesis of the dispersants in terms of 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.     

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.     

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.     

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.     

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.     

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.     

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.     

Synthesis of ZnS–Mn nano-luminescent pigment for ink applications

In the present study, ZnS–Mn nano-luminescent pigments were synthesized, using co-precipitation method. Polyvinylpyrrolidine (PVP) surface modifier and Mn dopant concentrations were considered as affecting parameters. The luminescent ink was loaded with two different concentrations of pigments. The obtained ink was silk-screened on different types of fabrics mainly treated cotton, cotton and nylon. Structure, microstructure, luminescent properties of nano-pigments, inks and fabrics and also rheological properties of the inks were investigated. The results showed that the ceramic ink prepared with nano-luminescent pigment had high photoluminescence (PL) intensity. Moreover, the optimum concentrations of Mn and PVP for obtaining maximum PL intensity were found as 2 and 5 wt%, respectively. SEM images of fabrics indicated that nanoparticles were loaded, nonuniformly, on the fibers. The treated linen and nylon fabrics showed maximum and minimum PL intensity, respectively, due to ink penetration depth in the fabrics. Furthermore, washing fastness estimated for all fabrics was in the proper range.     

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.     

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.     

喷墨打印和喷墨印花用染料和有机颜料的进展

本篇是关于喷墨打印和喷墨印花用染料和有机颜料的综述文章。主要论述了用于纸张打印水性墨水的颜料和染料、纤维素纤维喷墨印花用活性染料、丝绸喷墨印花用酸性染料以及聚酯纤维喷墨印花用分散染料的进展情况。给出了组成各种墨水的典型配方。并预测了未来可能的发展趋势。     

Improved chemical resistance of ink‐jet printed micropatterns on glass by using dual‐functional compositions

UV curable and UV/moisture dual‐functional oligomers were synthesized by grafting trimethoxysilane and methacrylate segments on the polyimide oligomer chains. These oligomers and a dual‐functional monomer were used as ink compositions to enhance the chemical resistance of ink‐jet printed LCD color filter micropatterns, without sacrificing jetting performance. The molecular structure and molecular weight of the oligomers were altered to adjust the solubility of oligomer in monomers, together with jetting trajectory, drop size uniformity, and deposition accuracy of the ink‐jet inks. The chemical resistance, optical property, and mechanical property of the printed patterns depend on the oligomer structure, the arrangement of trimethoxysilane groups, and the molecular chain length. Straight lines and uniform dot arrays with excellent chemical resistance can be achieved. Dot patterns made of polymer‐silica hybrid materials and pigments remain unchanged after being immersed in γ‐butyrolactone for 200 min. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2049–2055, 2013     

Influence of chitosan posttreatment parameters on the fixation of pigment‐based inks on ink‐jet‐printed cotton fabrics

Cotton fabrics were digitally printed with pigment‐based black ink with an HP Desk‐Jet 880C printer. These ink‐jet‐printed fabrics were posttreated with chitosan samples for the fixation of the pigment‐based ink on the cotton. The influence of various parameters, including the molecular weight (MW), application method (pad–dry–cure vs pad–batch), concentration, and pH, on the degree of fixation (DF) of the pigment‐based inks was examined. The chitosan‐posttreated cotton samples were evaluated for their color strength, DF, color difference, and whiteness index values and their colorfastness properties. Chitosan samples with MWs of 150,000 and greater than 375,000 showed 100% (complete) fixation of the pigment‐based inks on the cotton fabrics. DF drastically decreased in the chitosan with an MW of less than 5000. Both the pad–dry–cure and pad–batch methods were found to be suitable for chitosan application onto ink‐jet‐printed fabrics. Chitosan with an MW of 150,000 showed 100% fixation at concentrations ranging from 0.3 to 1%. A further decrease in the concentration significantly decreased the fixation. High fixation values were achieved at acidic pH, whereas a neutral to alkaline pH resulted in poor fixation. The colorfastness properties for each parameter studied are also discussed. The posttreatment of the digitally printed cotton with chitosan was found to be very effective in fixing the pigment‐based inks. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of process conditions on the properties of surface‐modified organic pigments encapsulated by UV‐curable resins

Aqueous dispersions of nanoscale organic pigments were successfully prepared via ball milling and ultrasonication. The dispersed organic pigments were encapsulated into UV‐curable resins via a mini‐emulsion technique. Critical factors that affected the dispersion and encapsulation stability were investigated. The encapsulated organic pigments were characterised with transmission electron microscopy, thermogravimetric analyses, Fourier Transform‐infrared spectra and zeta potential. The results clarified that the type of dispersing agent plays an important role in achieving maximal dispersion stability. Encapsulated organic pigments showed greater dispersion stability, and better wettability than the original pigments. Polyester tetra‐acrylate oligomer can stabilise the mini‐emulsion from diffusion degradation and inhibit phase separation with time. 1,6‐Hexandiol dimethacrylate was the monomer of choice for ink‐jet printing inks. Furthermore, it was found that monomer/oligomer and pigment/resin ratios were more influential and needed to be optimised. Thermal analysis, ultracentrifuge sedimentation and morphologies provided supporting evidence for the encapsulation of organic pigments into UV‐curable resins.     

Ink‐jet printing of nylon fabric using reactive dyestuff

This study discusses ink‐jet printing of nylon fabric with reactive dyestuff. Specifically, this paper investigates the impact of the concentration levels of pretreatment paste on fabric permeability, and examines the influence of various acid agents, hygroscopic agents and different processing conditions on colour yield. Results show that ink‐jet printing displayed excellent wet fastness in repeated wash testing. This study used four reactive dyestuffs, cyan, magenta, yellow and black, all of which achieved both wash fastness and crock fastness of grade 4.     

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。