Advanced Materials Research Vol. 380

Abstract: Edible ink-jet ink is environmental friendly and all of its materials reach the food sanitation standards, so it can be directly printed on the surface of food, medicine and packaging in the way of non-contact ink-jet printing. Due to the acid and alkaline of food surface are different, and the food may experience low or high temperatures and long time exposure in the preserved process, so the stability of the ink is of vital important. Edible ink-jet ink has been prepared through choosing reasonable materials. And then, the performances of the ink such as viscosity, surface tension and pH value have been tested. Finally, the best formula of ink has been determined by evaluating the influence of the ink performances to the ink-jet printing quality. We prepared ink sample based on the best formula and stored it in normal temperature environment which is closed to outside, and evaluated the stability of the ink performance through regularly checking its performance; we evaluated the stability of the ink color under different PH value through adding a little acid-base regulator in it; we also evaluated the stability of the ink color to temperature and light through putting the coating sample in the environment with alternate high and low temperature and in the environment with strong light. The result shows that the stability of the ink is fine, and it can be preserved a month at least without any food preservative. The pH value, temperature and light have no influence to the ink color. So it has a favorable color performance and can be printed on the surface of food.

Abstract: With the development of fluorescent technology, the application area of fluorescent material is expanding, which includes the fields of traffic, national defence, architecture, detection, decoration etc. In the field of printing, whether in the value of utility or view and admire, fluorescent adds tremendous energies. However, a majority of fluorescent materials used nowadays contain radioelement, which will do harm to human health. This paper considers the needs of fluorescent map printing, according to the defects of traditional fluorescent material such as low brightness, short duration time, strong radioactivity, limitation to spot color printing etc. It improves the capability of long fluorescent lag material and makes red, blue, green and yellow long fluorescent lag materials. Meanwhile, it tests the influence of ink thickness, illumination time and granule size etc. on irradiance capability. The thicker the ink is, the longer of the lag time will be. The bigger the granule size is, the lag time will be. It also tests its radioactivity extent, which is in the safety range and reaches the standard of environmental protection. According to the special requirement of map printing, this paper brings forward the technique scheme of the application of long fluorescent lag ink in map printing,which realizes the color fluorescent map printing.

Abstract: There is more and more wide application of UV offset ink in green printing and packaging areas. The offset ink is emulsified inevitably and it will cause a great influence on the ink properties. UV offset ink samples prepared with different prepolymers. Base on the measurements of flow curve, thixotropy and dynamic viscoelastic properties under different emulsification ratio to explore the influence of emulsification on the rheological properties of UV offset ink as well as the effect on the rheological properties with different prepolymers at maximum emulsification ratio. The results indicated that the ink viscosity, thixotropy and dynamic viscoelastic properties decline as the increase of emulsification ratio. Compared with polyester prepolymer ink sample that the emulsified ink sample with epoxy prepolymer shows a faster declined in viscosity, lower thixotropy and larger G’ value. This variation trends relate to the viscosity and net structure of the emulsified ink system.

Abstract: With the aim to study the effect of prepolymer on performance of UV ink-jet yellow ink , prepare UV ink-jet yellow ink color paste by change prepolymer and pigment/binder , test it’s particle size and distribution, explore the effect of different prepolymers and pigment/binder on the dispersion property; make ink color good dispersion paste into ink by using different film forming prepolymers, test the surface tension , viscosity , and curing speed, explore the effect of different prepolymers on the performance of UV ink-jet ink. The results indicate that, prepolymer on the dispersion property has great influence, color paste prepared by prepolymer CN2303 at pigment/binder for 2:1 has minimum particle size, and has good dispersion, film forming prepolymers has great influence on viscosity and curing speed of ink, has little effect on the surface tension of ink.

Abstract: Synthesis and fluorescent properties of rare earth Rare earth complexes ultraviolet photochromic materials such as ternary and quaternary europium complexes were synthesized in this,we selected the high luminescent β-diketones such as α-thenoyltrifluoroacetone(HTTA),fine fragrant carboxylic acid and o-phenanthroline as ligands. The structure of the ternary and quaternary europium complexes were studied by IR spectrum, indicated that these complexes have bonded with the ligands. The fluorescent properties were studied systematically by fluorescence spectrophotometer, relative fluorescence intensity of the ternary and quaternary europium complexes were quantitative determinated ,these europium complexes showed invisible in the visible light and showed obvious red fluorescence under ultraviolet light. This study of the rare earth europium photochromic materials have theoretical and practical application guidance to security printing ink and packing. Experiment shows, The fluorescence properties of Eu(BA)₃Phen and Eu(BA)(TTA)₂Phen indicated that two excitation spectrum are banded spectrum, the energy which the ligands have absorbed transmitted effectively to europium ion. The fluorescence emission bands of Eu(BA)₃Phen and Eu(BA)(TTA)₂Phen are similar, but the relative fluorescence intensity of ⁵D₀→⁷F₂ of Eu(BA)(TTA)2Phen is far bigger than Eu(BA)₃Phen. The two complexes have the low symmetry, have the good monochromaticity.

Abstract: pH value of fluorescent ink-jet ink has an obvious influence on fluorescent powder, high or low pH value could cause some problems, such as fluorescence quenches, fluorescent quantum yield decreased, and so on. And these factors make against fluorescent ink-jet ink luminous properties reach the best result. This article is to design fluorescent ink-jet ink formula when it is exposured to deep Ultraviolet light to display green, and a series of ink samples were prepared. pH regulator was used to regulate pH value of green fluorescent ink-jet ink system. This paper discusses the effects of pH value on luminous intensity, fluorescent quantum yield. The results indicated that triethanolamine can regulate pH value of fluorescent ink-jet ink, when pH value increases from 8.70 to 11.20, luminous intensity, fluorescent quantum yield have a decrease tendency.

Abstract: The photo-initiator has a crucial role in the curing system of water-base UV varnish. The formulation of water-base UV varnish was designed and 4 different photo-initiators were chosen to make samples to study the effect of photo-initiator on the curing system of varnish. The curing results were tested and were compared. The results showed that the type and proportion of photo-initiator has great effects on the curing rate of water-base UV varnish, the best photo-initiator is 907. The mixed photo-initiators 907, TPO and ITX have been designed and the samples were prepared using the way of a formulation experiment. The result indicated that the curing rate of complex photo-initiator was lower than the curing rate of photo-initiator 907. The curing effect of the varnish samples is the best when the quantity of photo-initiator 907 is 6%。

Abstract: In order to obtain good watermark on paper by printing, vegetable oil system and UV light-curing system watermark varnish were prepared by changing the type of vegetable oil, prepolymer and monomer, then test its permeability and refractive index, study the effects of these components on the performance of watermark varnish. Print watermark varnish by screen printing to examine the watermark. The results show that watermark varnish prepared with different type of vegetable oil has different permeability, but refractive index is very close. Adding prepolymer can improve permeability and refractive index of vegetable oil system watermark varnish. If the specific gravity of prepolymer and monomer is greater, permeability of UV curing system watermark varnish is higher. If refractive index of prepolymer and monomer is bigger, refractive index of varnish is bigger. Printing effect of UV curing system watermark varnish is better than vegetable oil system watermark varnish.

Abstract: With the development of the green inks, UV ink has been applicated wider and wider in the printing, packaging and the electronics industry. Based on the UV inks and screen printing process, this paper has investigated the influnce of mesh count, screen ruling, printing materials and ink viscosity on print quality by measuring the printing dot gain experimentally. The results show that the higher mesh count and more smooth printing material can induce the better dot, tone reproduction and higher printing precision. The more serious dot gain and the worse tone reproduction will induced by lower ink viscosity. The higher screen ruling cause the bigger dot gain value. Bigger rate of mesh count with screening ruling can reduce the moire phenomena.

Abstract: Quaternary europium complex EuxGd_(1-x)(POA)(TTA)₂Phen were synthesized by doping no-fluorescent inert ions Gd³⁺ with ligands of POA, α-thenoyltrifluoroacetone (TTA), and o-phenanthroline(Phen).IR spectra was studied , indicate that these complexes have similar structures, have bonded with the ligands.The fluorescent properties,the influence of fluorescent property by doping ions Gd³⁺ were studied. The results showed that the doping ions Gd³⁺ can enhance the fluorescence intensities, the best mole ratio of europium to gadolinium is 6：4.