環保弱溶劑墨水中的色料之探討與分析

數位噴墨印刷技術不斷進步，選擇良好的墨水，將有利於維持印刷品質，也可以保證產品的成功率以及綠色環保的要求，其中色料是墨水的關鍵成分，用量必須嚴格控制，當使用量在某一含量範圍時，會使光學密度提高較快，超過這個範圍時光學密度則升高的較慢，因此這個轉折點即為最佳用量，而色料又分為顏料及染料。　　初步發現白色墨水與其他顏色墨水有所不同，判斷原因是白色墨水色料是顏料，而有顏色墨水色料則是染料，進一步本實驗透過薄層色譜及UV-Vis光譜分別測定白色墨水與紅藍黃黑四種顏色墨水，得知色料在墨水中約占5%，並得知黑色可能是由藍色、紅色、黃色混合組成，利用IR光譜確認白色墨水中的顏料是二氧化鈦，利用TGA得知樹脂在墨水中約占15%及二氧化鈦約占5%，最後利用掃描電子顯微鏡觀察到顏料的分散性良好及有較小的粒徑。

關鍵字

環保弱溶劑墨水；顏料；染料；薄層色譜；紫外光/可見光吸收光譜；紅外線吸收光譜

並列摘要

As the constant progression of digital ink-jet technology, the selection of good quality inks would not only favor the maintenance of printing quality but also the success rate of the printing products and meet the pursuits of Environmental protection. Also color materials play an important role in the production of inks. The usage of colors should be strictly controlled. When the dosage of colors within the specific range, it would make the elevation of the optical density faster. When the dosage of colors above the specific range, it would make the elevation process slower. Therefore the turning point would be the best dosage. Meantime, color materials can be divided into types, the pigment and the dye. In this research it was found that the white ECO-solvent ink was the difference with the color ECO-solvent inks. The white ink was made of pigments while the color inks were made of dyes. By using thin-layer chromatography and ultraviolet–visible spectroscopy, the white, red, blue, yellow and black inks were analyzed and the results were around 5% of the dye (or pigment) in the inks and the black ink was the mixture of blue, red and yellow inks. By using infrared spectroscopy, it was found that titanium dioxide is the pigment of the white ink. By using TGA (Thermo gravimetric analysis), the results were about 15% of resin in the inks and 5% of titanic dioxide in the white ink. At last using electron microscope, these results were found that the dispersibility of pigments in the white ink was satisfactory and the particle size was relatively smaller as well.