Market Expansion and Technical Development of Water-based Ink(I)

　　 As early as the 1960s, people started the research and application of water-based inks. Due to environmental protection requirements and the shortage of petroleum raw materials, some developed countries have gradually banned the use of petroleum products for the manufacture of printing inks. As a result, people started to study non-organic solvent-based inks, making water-based inks have made great progress and development. Initially, water-based inks mainly used binders such as dextrin, shellac, casein, and sodium natrium as water-based inks. The prepared aqueous ink is mainly used for printing some low-grade products.

By the end of the 1960s, with the development of materials science, the synthetic technology of rosin and maleic acid modified resins succeeded, replacing casein, shellac and other materials, becoming the main material of water-based inks, and basically meeting the printing needs at that time. However, these primary products still have some drawbacks, such as poor gloss, poor water resistance, poor adhesion and foaming, and poor storage stability. Later, people called the water-based ink produced at this stage the first-generation product.

In the 1970s, due to the oil crisis, raw materials for inks were once again very tense. At the same time, the governments of various developed countries have legislation to control air quality and limit the emission of organic volatiles (VOC) to the atmosphere. They have strict requirements for food, beverages, and pharmaceuticals. Packaging and printing products (heavy metals, residual volume, etc.) are packaged. Ink research and development personnel from various countries have continued to conduct in-depth research to produce a solution-type styrene-acrylic copolymer resin as the second generation of water-based ink connection material, this product makes up for the first generation of water-based ink water resistance and poor storage stability. However, there is still a gap between gloss and printability compared with solvent inks. To this end, ink developers based on the second generation of water-based ink, the introduction of monomers such as acrylic acid and styrene polymerization, developed a polymer emulsion resin with a core-shell structure and a network structure, the series of resins has been greatly improved The luster and dryness of the ink promote the development of water-based inks, and the competition between water-based inks and solvent-based inks continues to widen the application fields. Water-based ink has entered a new period of development.

China's water-based inks were first produced in the Tianjin Ink Factory. At that time, gravure printing services were mainly used. At that time, gravure printing inks were improved from benzene solvents to gasoline-based solvents. Although the toxicity was lower than that of benzene inks, they were flammable. Sex did not improve. Therefore, it was proposed that the gravure printing ink be further improved to a non-toxic, non-flammable water-based ink, which was called water-concave ink at that time. Since the ink is made of a rosin acid amine salt as a main binder. The connecting material is not stable in an aqueous medium, so the ink is easily lost in storage, depleted, poor drying, poor water resistance, easy to cause paper shrinkage and other defects, so that China's gravure printing and flexographic printing is limited The use of high-grade water-based inks with high import prices has inevitably increased the printing costs and limited the development of the printing industry in China.

At the end of 2003, Wuhan Modern Industrial Technology Research Institute developed a series of water-based ink products that are non-toxic, non-irritant, non-corrosive, non-flammable, non-explosive, and safe to use. The new ink series production technology can be widely used in gold, silver cardboard, coated paper, white paper, corrugated paper, adhesive paper, cartons, paper bags and books and magazines. In early 2004, Shanghai Meide Fine Chemical Co., Ltd. recently launched a full-water low-temperature thermosetting ink. The formaldehyde content of the product is less than 15ppm, in line with the environmental protection requirements of Japan and Germany textile printing and dyeing. MD-1002 water-based low-temperature thermosetting ink has a high hiding power, delicate texture, can over 250 mesh screen, not blocking the network, easy operation, ink color can be their own deployment. The ink is odorless and is a high quality, environmentally friendly product. Since the past plastisol inks must be baked at high temperatures, they often cause discoloration and deformation of the fabric. This all-hydraulic low-temperature thermosetting ink completely avoids the above phenomenon. Generally, the heat treatment of the finished product can be baked at 120° C. for 1-2 minutes just like ordinary paste printing. The ink has excellent stretchability to the knitted fabric, and the water washing and the dry friction are up to 4 grades, and the holding period in the sealed cool place can reach 5 years. Its biggest advantage is to save electricity costs, which greatly reduces production costs. This product can be widely used in all kinds of fabrics such as cotton, chemical fiber, etc. except waterproof nylon cloth.

The demand for water-based inks is promising

The main application fields of environment-friendly water-based inks are flexographic printing and gravure printing. Most of the products of these two printing methods are packaging products, and food packaging, tobacco packaging, and children's toy packaging occupy a considerable proportion.

In recent years, flexographic printing has developed rapidly around the world and is considered to be “the best and most promising printing method on the planet” in developed countries in Europe and America. U.S. 95% of flexographic prints and 80% of gravure prints use aqueous inks. Flexographic printing is still in its infancy in China and currently accounts for only about 3% of the printing industry. In the flexo package printing, the vast majority of domestic and foreign water-based ink printing. At present, 40% of U.S. plastic printing uses water-based inks. Other developed countries, such as Japan, Germany, France, etc., are also increasingly using water-based inks in plastic film printing. The United Kingdom also enacted legislation in June 2003 prohibiting the use of solvent-based inks to print films for food packaging.

With the rapid development of our country’s economy, people’s awareness of packaging aesthetics and environmental awareness have continued to increase. From 1995 to the end of 1998, China has introduced more than 130 modular flexo lines in just a few years. It is distributed in more than 20 provinces and cities across the country, 90% of which are narrow-format flexo presses. Nowadays, the domestic market is narrow and flexible. There are nearly 200 print production lines. Now it is increasing at a rate of about 30 units per year, and there are also many imported high-end three-color and four-color water-based ink printing slot machines for color printing of corrugated paper.

There are more than 1,000 carton factories in each province in China. If 10% of water-based inks are used to print high-grade cartons, each household ink will have a tonnage of 10 tons. Each province needs about 1,000 tons of water-based ink every year. This does not include inks used in other printing and packaging products for flexo and gravure printing (currently, 100% of domestic flexographic printing uses water-based ink, and 80% of gravure printing uses water-based ink). It is imperative to vigorously develop, develop and produce high-grade water-based inks. The product can be widely used in gold and silver cardboard, coated paper, whiteboard, plastic film, corrugated paper, self-adhesive paper, carton, paper packaging, books and magazines. Etc. Flexo and gravure printing fields.

Although flexographic printing is still in its infancy in China, it currently accounts for only about 3% of the printing industry. However, with the increasing popularity of environmentally-friendly packaging, many tobacco companies, wineries, pharmaceutical companies, cosmetics factories, and children's toy companies are ready to adopt it. Flexographic printing product packaging, the proportion of flexographic printing in the printing field will gradually increase, especially in the field of packaging and printing. It is estimated that by 2010, the flexographic printing market will reach a share of about 15%, and annual demand for water-based ink will be more than 100,000 tons.

Therefore, it is imperative to vigorously develop, develop, and produce high-grade water-based inks, and the market has great potential. The product can be widely used in flexo and gravure printing fields such as gold and silver cardboard, coated paper, white board, plastic film, corrugated paper, self-adhesive paper, carton, paper packaging, books and magazines.

Advantages and disadvantages of water-based ink

Researchers in various countries are stepping up the development of environmentally friendly inks. At present, there are three major categories of environmental protection inks: water-based inks, UV inks, and water-based UV inks. Water-based inks (Water-based inks) are simply called ink inks and are produced by compound grinding of water-soluble resins, organic pigments, surfactants, and related additives.

Due to the absence of volatile organic solvents, water-based inks greatly reduce the emission of organic volatiles (VOCs, the same below), thereby reducing air pollution, improving the environment for printing operators, and contributing to the health of employees. It can completely eliminate certain toxic and harmful substances in solvent-based inks, eliminate the harm to human body and the pollution of packaged goods, and improve the overall environmental quality. It is especially suitable for tobacco, wine, food, beverages, medicines, children's toys and other health Conditions require strict packaging and printing products. In addition, it can not only reduce the risk of fire and hidden dangers caused by static electricity and flammable solvents, but also reduce the toxicity of printed surface residues, and it is convenient for cleaning printing equipment.

Whether it is imported water-based ink or domestic water-based ink, the printing performance and quality cannot reach the standard of solvent-based gravure ink. At present, water-based inks have drawbacks such as non-alkali resistance, non-anti-ethanol and water resistance, slow drying, poor glossiness, and easy paper shrinkage. This is mainly due to the higher surface tension of water (72 dynes/cm), which makes the ink difficult to wet and dry slowly. In order to use water-based inks in gravure printing machines, not only inks and resins require advanced technology, but also gravure printing equipment needs improvement. For example, changing an etching drum with a groove depth of about 38-42 μm to a laser pattern making drum with a groove depth of about 24-28 μm also requires more effective and more powerful drying equipment and components such as rollers, pumps, and doctor blades made of corrosion-resistant materials. Because all these require a lot of investment, water-based gravure inks are still not widely available in Europe and the United States. Ink is difficult to wet and print on substrates such as polyethylene; drying time is still the most important issue for ink applications, unless the press is equipped with enough drying equipment, or the printing speed is affected; water-based gloss Lower than the solvent-based ink, greatly limiting the use of ink in places with high gloss requirements.

Since water-based gravure inks are not yet fully capable of replacing toluene inks, the ink industry has been working hard to develop environmentally acceptable alcohol-soluble inks. Alcohol-soluble ink can help us to solve the health problems caused by toluene ink and solvent residues affect the quality of packaged foods and other issues. In Europe and the United States, this development has become a trend. To achieve alkali resistance, ethanol resistance, water resistance, and gloss enhancement, only flexographic UV inks are used. This not only increases the printing cost but also increases the printing process. If there is an automatic packaging line for beer packaging, the use of alkaline lubricants, the PH value of 9-10, water-based ink can not bear, touch it on the fade. There is also summer when the South sells beer, not only to enter the refrigerator, and some are still immersed in icy water for a long time, and water-based ink cannot withstand it.