Research on the Manufacturing Method of Solvent-based Plastic Surface Printing Ink Paste (Part One)

Abstract: Wax is one of the key additives in plastic intaglio printing inks, especially in the solvent-based plastic film gravure printing inks for polyamide resins and nitrocellulose (nitrocellulose) systems. The printability and adhesion fastness of the system have a very important role; For the compatibility and miscibility of various common waxes for the ink system, it can be foretold that the polyamide system plastic table intaglio printing plate using the wax additive The quality of the ink. The analysis and introduction of the special waxes used for this solvent printing ink in the system, as well as the intermediate products in the use of these waxes and solvent-based plastic printing inks. ---- The wax, vowing will allow more readers and ink manufacturers to understand it more comprehensively, and then to choose it, and even well apply it. Here, I hope that readers can benefit from reading this article and realize some inspiration, without losing the article here.

Keywords: Solvent-based plastic gravure printing ink, polyethylene wax, influence, research, application.

Foreword

Solvent-based plastic intaglio printing inks are often applied to an auxiliary, it is often referred to as wax, wax made of pulp is also the intermediate of ink production ---- wax, professional professionals say Kang Bang (English for Compound). Among the large family of waxes, polyethylene wax is the most widely used type of solvent-based polyamide system plastic gravure printing ink. Waxes can be divided into natural waxes and synthetic waxes. There are animal waxes (such as beeswax), plant waxes (such as cane wax), mineral waxes (such as paraffin wax and montan wax), and synthetic waxes (Fischer wax). , polyethylene wax, polytetrafluoroethylene wax, fatty acid amide wax, copolymer wax and so on. In this paper, only the polyethylene wax in the synthetic wax is used as the standard, and some experimental data and ink applications are used as examples to discuss some characteristics of polyethylene synthetic wax in solvent-based plastic surface gravure printing inks, and through the use of polyethylene wax. The effect of physical properties on the quality and performance of solvent-coated intaglio printing inks, some researches on the manufacturing methods of solvent-based intaglio printing ink special waxes, summarizing some empirical theories and the effects of practical use, for everyone to discuss and discuss. .

principle

Polyethylene wax used in solvent-based plastic gravure printing inks, the most important role is to improve the ink adhesion to the plastic surface of the ink film friction resistance; because it can be in the ink dry film surface to form "prominent" smooth particles, Improves the feel smoothness of the film surface of the surface printing ink, enhances the water resistance and scratch resistance of the ink film, makes the surface of the printing ink highly resistant to abrasion, prevents adhesion during printing and winding; and the wax can also improve the solvent ink system The liquidity and anti-precipitation properties also prevent the solvent-based gravure inks from being printed on the plate due to fatigue, so polyethylene synthetic waxes are very important for polyamide-based solvent-based plastic gravure printing inks. One of the indispensable special additives.

However, not all synthetic polyethylene waxes can be applied to solvent-based plastic intaglio printing inks for polyamide systems. We have found that through continuous extensive experimentation and practical production experience, we can use polyamide waxes in solvent-based inks for polyamide systems. Ethylene wax, the general physical properties are:

Melting point: 80----130°C;
Molecular weight: 1500---4500;
Particle size: 5 --- 25 microns;
Density: 0.8---1.5 g/cc;

Because this synthetic polyethylene wax is almost insoluble in any organic solvent at room temperature, it can fully embody the performance of the wax in a solvent-based plastic intaglio printing ink. However, even if it is a polyethylene wax that meets the above specifications, factors such as different melting points, different molecular weights, different particle sizes, different densities, and different wax formulation designs will affect the use of wax as an additive in solvent-based plastic surface printing. Various properties of use in gravure inks. The performance of waxes used in inks includes ink fineness, dispersibility, stability, ink film drying, glossiness, rubbing resistance of ink film, etc.; of course, a deeper consideration is the size distribution of the wax, wax particles, The influence of factors such as the shape of the wax and the surface treatment of wax particles on the wax in the ink system, due to experimental conditions and space limitations, will not be further described in this article.

There are two methods for using polyethylene wax in solvent-based plastic surface gravure printing inks. One is to add wax powder directly to the ink formulation; the other is to add wax powder to the wax before adding it to the ink. The first method has the advantages of reducing the process of the ink production process and optimizing the process; the disadvantage is that the wax powder is not completely dispersed in the ink, the particles are coarse, and the ink film surface gloss of the surface printing plastic ink is reduced. Although the second method has a wax wax slurry process, it can make the wax powder well dispersed in the ink system, and has a good effect on the fluidity and anti-precipitation properties of the ink system. The ink film after drying the ink has a rather high gloss. Current ink manufacturers generally use the second method to add wax additives in solvent-based ink manufacturing processes.

experiment

A semi-finished wax slurry is first prepared using a polyethylene wax powder and added to the ink formulation during the production of the solvent-based intaglio printing ink to complete the use of the wax in the ink. Today's ink manufacturers use polyethylene wax to formulate semi-finished waxes. In general, the main body of the ink is mixed with the resin liquid and organic solvent. We use domestic low-molecular-weight polyethylene waxes, solvent-based plastic inks for printing inks, and organic solvents for inks. For raw materials, a series of analysis conditions were tested.

Experimental operation:

In the first step, the experimental wax powder is first made into a test wax slurry with a host resin solution and an organic solvent. The equipment used is a high-speed disperser, and the three are mixed at high speed and can be mixed uniformly. The test formula is as follows:

Experimental polyethylene wax 20---60%
Ink base resin liquid 10--30%
Organic mixed solvent (according to the test proportion) 70---10%
Test wax 100%

In the second step, the prepared wax is slowly added to the ink semi-finished product that has been ground to a fine quality and has not been added with any wax additive. The semi-finished ink is made of blue ink, and it is best to use a disperser. Adding slowly while stirring, while mixing can also observe the ease of dispersion of the wax slurry in the ink system, the dispersion performance of polyethylene wax powder in the ink system can be obtained; according to the solvent type plastic gravure The general addition amount of wax powder in the table printing ink, when we prepare the test blue ink, the addition amount of the test wax slurry is generally 2---5% of the blue ink, and the prepared test ink is placed well, and further performance is required for other properties. Experimental evaluation.