Nanotechnology tradition and digital printing applications

I. Introduction

The development and evolution of printing technology, the content is from symbols through text to black and white to color; manuscripts from analog to digital; production methods from manual to mechanical and then computer automation; and ink from water, oily up to the current nano level Printing ink. While developing digital inkjet printing globally, its core technology is not only focusing on how to develop high-speed, high-volume, low-cost machines, but also on inkjet and laser consumables research and development. In particular, the current major nanopigment or functional colorant is most suitable for wide color gamut, water resistance, weather resistance, low cost, high value, and applicable to a variety of substrates. At present, the application opportunities of nanopigments lie in the traditional printing ink and ink jet printing, which all have room for development. What is the ideal colorant property:

1. Fresh 2. Good penetration 3. High color intensity 4. Lightfastness 5. Water resistance 6. Durability

In general, dyes have the advantages of fresh color, naturalness and good penetration, and problems of being resistant to water, light resistance, and poor tolerance. Usually applies to textiles, wood and indoor printing, etc.; while traditional pigments have the advantages of water resistance, light resistance, and weather resistance, but there are shortcomings of insufficient color, saturation, poor color strength. Suitable for printing, coating, outdoor printing. With the nanoscale pigments that have been developed in the current laboratory, the main difference lies in the size of the particle particles. The average particle size of conventional pigments varies from 100 to several micrometers (um), while the definition of nano-grade pigments can be said to be less than 100 nm. The current appearance of nano-scale products is mostly darker than the original color. The reason is that the particles become smaller and the body surface area becomes larger. As the light penetrates the pigment, the small particles continuously scatter when the light travels through the paint, and the light emitted is less. As a result, the reflectivity drops and the optical characteristics change, so that it looks a little darker. The viscosity also varies from hundreds of thousands to tens of thousands of lower viscosity (about less than 20 cps).

two. Industry entry point:

1. Development of digital inkjet stations and ink heads: Digital ink jet printers and their consumables are currently in low demand in the market. They are mainly based on water-based pigments and dyes; they may also involve the development of patents by other companies. , it can be another quick-drying or hardening of the machine and the ink head in two aspects.

2. Preparation of Pigment Dispersed Color Masterbatch: At present, it is a technical cooperation between Japan and other countries, and it is necessary to develop its own technology so that the upstream and downstream industries can be connected and not limited to others.

3. Traditional ink formulation technology: When the pigment reaches the nano-particles, the particles are easy to aggregate, so the particle stabilization technology is the primary condition.

4. Digital inkjet formulation technology: Various types of water-based inkjet inks (table, wide and industrial), UV-curable inkjet applications. Its main niche point depends on the following four points:

1. Replace imported products 2. Establish new product technologies 3. Reduce costs 4. Diffusion application technology

three. Nano pigments for inkjet printing applications:

1. Digital ink jet or traditional color filter

2. Desktop/Industrial/Commercial/Wide/Photo Inkjet Printers

3. UV Curing Ink Jet Ink to Large Signage/Posters

four. What is nano?

Nanometers are descriptions of the physical scale, 1 nanometer (nm) is 10-9 meters in length. At the nanometer scale, generally referred to as being between 1 nm and 100 nm, the material properties do not belong to the macroscopic (macroscopic) field of vision of classical physics, nor do they belong to the microscopic behavior of quantum physics, but to the so-called so-called microscopic behavior. Mesoscopic phenomena. Nanomaterials means that atomic clusters (including grains or phases) form at least one dimension in the range of 1 nm to 100 nm, so they include nanoparticle, fiber, particle film, multilayer film, or nanophase material composed of clusters of atoms. (1nm = 10-9 m). The scientific dimensions of nanometers are: m -100 m mm --10-3 m micron --10-6 m nano --10-9 m five. Difficulties and technical bottlenecks of pigment nephronization: Today's pigments are generally aggregated macroparticles of several micrometers to submicron units, and now have a specific surface area of ​​1 unit to achieve nanometer-sized particle sizes (< 30 nm). It becomes 100 units, and Van de Waal force will be greater than 100. At this time, its most important problem lies in the two aspects of grinding dispersion technology and inkjet formulation and colloid dispersion stability technology.

1. Grinding and dispersing technology:

In the process of pigment pulverization, the grinding method is mainly based on wet grinding and dispersion. The method is to impact and grind with high energy dispersant and high collision frequency (20~30m/s). Here are the two main parts of the grinder and the grinding material.

A. Grinding machine:

(a). Traditional grinding machines: There are two vertical and horizontal types. Nowadays, horizontal bead mills are generally used. The disadvantages are the complex system design, difficult maintenance, and expensive grinding media (>0.25 mm). The vertical bead mill is rarely used due to the large weight of the ball and its concentration in the bottom of the machine, resulting in uneven grinding.

(b) Nano-scale dispersion equipment: The Institute of Chemical Industry has developed a new grinding media separation system to improve the existing equipment. It is a material manufacturing equipment that can wear, high heat transfer effect, can use ultra-fine media (<100 um) grinding process, increase the speed of the blade (> 15 ~ 30m / s) machine.

B. Grinding medium: The current grinding material is mostly lanthanum or zirconium material, and the traditional grinding material is 0.30-1.0 mm, while the real good material is less than 0.1 mm (ultra fine media). It can increase the collision point between particles and increase the effective shear surface.

2. Ink-jet formula and colloidal dispersion stabilization technology: To prevent the cohesion between particles from affecting its stability, dispersants or surfactants can be used. The principle is to add the dispersant or surfactant to make the surface of the particles charged. Based on the principle of same-sex repulsion, the particles will not attract and accumulate to each other, so as to achieve stability.

six. Application of Nanopigment / Market:

Application content characteristics related to the industrial market value (100 million yuan) ink color quality wide color gamut 20 (2~3%) coating color quality wide color gamut 300 (2~3%) Ink Jet ink color quality color gamut wide 4 (20~ 30%) LCD Light Transmittance Enhances Color Gamut Color Quality 6 (20~30%) Textile Printing Color Quality Gamut Wide>10

Seven. Conclusion:

The technology of nanopigment can be widely applied to every kind of technology, such as in the aspect of traditional printing ink, can increase the color saturation and reduce the number of color matching masterbatch; on the ink jet printer can increase the color gamut 1 times and Durability; In the display, can increase the color gamut and light penetration force more than 10%; In the textile inkjet, there can be a small amount of diverse fabric inkjet and environmental protection and low pollution advantages ... ... and so on, even medical Use and special cosmetics can be used for effective use. At the same time, two things to note: cost and effectiveness. If the product developed has a high unit cost, it may be difficult to popularize and the market may not accept it. In addition, if the effect is not as expected or if the difference between the original process and product is not significant, the same is true. Will affect the follow-up research power. Therefore, nanopigment is a new development trend in the future, but we are not sticking to the size of the particle size, but focusing on the benefits of miniaturization, so as to increase the added value of products and enhance the competitiveness of the industry. We are pursuing the true purpose of the new technology.