Accurate evaluation analysis of pigment in the ink quality features

Accurate evaluation of pigment in the ink quality, for paint and ink workers is a very important work.

1 organic pigments, printing inks application performance evaluation due to the way of printing, printing materials, printing ink varieties and types of many, the link types, etc Can there is a big difference, therefore, the evaluation of a paint quality whether meet the requirements of the ink must first from the view of practical application to determine the application of paint System type, according to different links of system to select the corresponding performance evaluation methods, so as to more accurately grasp the application of the paint performance.

(1) four-color offset printing ink pigment application performance evaluation

At present, the main use in four-color offset printing ink rosin modified phenolic resin, in the process of production of the resin has been given, such as water resistance, film strength And adhesion, and paint the wettability of various problems, so the application performance of such paint will revolve around the physical and chemical performance of the adhesive ink links Correct evaluation, that is to choose the corresponding test methods. Such as for dry powder paint, ink can be made from three roll grinding method to detect pigments in all kinds of quality Quantity index, and can accurately evaluate the dispersion.

For some special filter cake, you can directly made ink commutation method squeeze water base ink to evaluation.

(2) solvent ink pigment application performance evaluation

Because the links made of resin and solvent feeding system of the physical and chemical performance difference is bigger, pigment for solvent printing inks evaluation need more targeted. by In the links of different solvent ink material has different properties, so the links should be based on different material system to select different application performance of the paint.

Water-based ink quality requirements of pigment in is much more strict than other types of solvent-based inks, mainly embodied in the pigments of water-based ink rheological properties The effect. At present, water-based ink generally use acrylic resin emulsion system, due to the particularity of the system, some applications in other system performance Good pigment varieties in water-based ink link material in the system may not be able to use. For example, the widely used azo lake red PR57:1 pigment, ordinary varieties used in water base Ink often caused when the viscosity is too high, and the longer the storage time, ink is thick, the serious influence its printing eligibility. To solve this problem, should adopt the necessary surface Processing technology and methods of mixed color lake to improve them.

In addition, the solvent resistance transference of ink on the substrate, the boiling resistance requirements also have to pay attention to, the chemical structure of organic pigment, molecular weight , crystal particle size, polarity and the kinds of surface treatment agent used in the manufacturing process, etc., are likely to impact on it.

2 paints, printing inks physical and chemical properties analysis

Data from the application of performance evaluation is printing inks paint quality characteristics of a form. But decided this is the manifestation of the internal factors Physical and chemical properties. The fact that the physical and chemical properties of organic pigments analysis and application of performance assessment, can act as both alone cannot achieve the effect of the evaluation .

Using the instrument analysis evaluation of physical and chemical characteristics of organic pigment is a kind of efficient and fast method. Organic pigments of instrument analysis mainly includes the following two parties Aspects, to the chemical molecular structure and the determination of elements. Among them, the latter of organic pigment in the ink is more important to evaluate the performance of practical application. Among them, The latter performance of organic pigments used in printing ink that strong. Commonly used organic pigment chemical analysis instrument meter has the following kinds: (1) particle size distribution. Size distribution apparatus (PSDA) can be used to measure the particle size and distribution of pigment particles dispersed state region. Ideally, the more concentrated the particle size distribution, the better, to Maximum guarantee clear of pigment, transparency and tinting strength, light fastness and dispersion stability, etc.