Vegetable inks

Although the application history of vegetable oil-based printing inks in China has been a long time, due to the many defects caused by its backward production process and technical level, petroleum-based inks with quick-drying properties quickly replaced vegetable oil-based inks. For a time, vegetable oils The research and application of base printing inks are in a downturn.

The global oil crisis that took place in 1979 led to the continuous rise of oil prices at that time, affecting related industries including the printing industry. To alleviate the impact of the oil crisis, the American Press Association of the Newspapers (ANPA), now the American Press Association (NAA), has stepped up efforts to develop non-oil-based printing inks. After years of experimenting with a variety of vegetable oil formulations, the final choice was to use soybean oil for vegetable ink formulation and in 1987 a press printing test was successful. In the first year when soybean ink was put into the market, only six newspapers were used. Nowadays, one-third of the more than 10,000 newspapers in the United States have used soy ink, especially since its effect has been affirmed by the larger 1300 daily newspapers. Its usage also increased from the initial 45 tons to 41,000 tons in 2000. In Japan, the application of soy ink has just started. There are hundreds of ink factories that produce soy inks. There are nearly 200 printing plants in use. In 1998, the consumption was about 859 tons. Soybean ink meets the requirements of Japan's emphasis on environmental protection, and future usage will double. Soybean ink applications are also being promoted in Europe, Australia, South Korea and other countries and regions. In China, there are few research work in this area, and only some preliminary experiments on the synthesis of vegetable oil-based ink binders have been conducted.

The vegetable oil-based inks that have been developed include: black and colored inks suitable for lithography and letterpress printing using alkali-based soybean oil, Canola oil, cottonseed oil, sunflower oil, and safflower oil as raw materials. The 100% vegetable oil-based ink removes hydrocarbon resin, reduces the amount of pigment, provides a competitive price, can be used as a substitute for petroleum-based inks; synthetic alkyd resin modified with rapeseed oil and sunflower oil Thermosetting and fast-drying offset inks, which use vegetable oil-derived fatty acid methyl esters instead of mineral oils, but thermosetting offset inks have poor performance; there are also many lithographic, gravure inks based on vegetable oils. In these products, vegetable oil or modified as a resin, or as a solvent, effectively reduces the VOC content, but in order to ensure printing performance still contains a certain amount of petroleum resin or solvent. I believe that with the improvement of environmental awareness, the development and use of vegetable oil-based inks will increase.

First, the benefits of using vegetable inks

The use of vegetable inks is more advantageous than the use of traditional petroleum-based inks, mainly in the following aspects:

1. Vegetable inks have excellent environmental protection. Traditional petroleum-based inks usually contain a large amount of volatile organic compounds that are harmful to the human body. When inks are manufactured, printed, or dried, or when equipment is washed and waste inks are processed, a large amount of organic components are volatilized, which not only seriously harms the health of production operators. , And cause great damage to the environment, the current evaporation of VOC in printing ink has become an important source of environmental pollution. The PAHs in the plant inks are low in content and do not emit VOCs when used. They do not harm the environment and are beneficial to the health of manufacturers and users. At the same time, the oil that traditional inks rely on is a non-renewable resource, and it is increasingly depleted with a large number of uses. The energy crisis has become the biggest problem faced by mankind, and many industries have turned their attention to renewable plant resources such as biodiesel. The soybean oil in vegetable inks is derived from natural, can be infinitely regenerated, and can be biodegraded. It has the unparalleled advantages of traditional inks both in terms of resource utilization and environmental protection.

2. Vegetable inks have excellent rub resistance and light and heat resistance. Traditional petroleum-based inks have poor print rub resistance and are easily stained by black readers' hands. Soybean inks are more resistant to friction than traditional inks, freeing newspaper readers from the darkness of hand-smearing and without the unpleasantly pungent odors. In addition, the boiling point of vegetable inks is much higher than that of petroleum volatiles. When heated on a laser printer or copier, it does not stick to paper due to volatilization. Therefore, vegetable inks have unparalleled advantages over conventional inks in this regard and will be welcomed by consumers.

3. The use of vegetable inks is cheaper for integrated printing. It was found that vegetable inks are easier to deink than traditional inks, and that paper fibers have less damage and good quality recycled paper. The use of this characteristic of vegetable inks results in less wasted waste and less recycling costs in waste paper recycling. Waste ink residue after deinking treatment is more likely to be degraded, which facilitates wastewater treatment and controls the quality of discharged water. Soybean inks have a wide range of colors, rich colors and bright colors. A small amount of ink can exhibit the effects that a large number of traditional inks can exhibit. In addition, because traditional inks contain organic compounds and substances, in order to avoid causing environmental pollution, its disposal has become a problem that plagues ink manufacturers and printers. However, soy inks can be backfilled with new inks for mixing, which is not only conducive to environmental protection, but also reduces production costs.

4. The use of vegetable inks complies with industrial policies. China is a large agricultural country and the main producer of soybean in the world. The development of vegetable oil-based inks represented by soybean ink not only conforms to the national energy industry development policy, but also promotes the development of the domestic vegetable oil industry and expands the application of vegetable oils. , And can reduce the consumption and import of non-renewable oil for the country to save foreign exchange, but also in line with rural industrial policies, benefit the country and the people, the overall benefits unmatched.

Second, the development of vegetable oil-based inks existing problems

Although the history of vegetable inks has been for several centuries and has many excellent features, the main factors used in our country today are oil-based inks. The main reasons for this are as follows:

1. The price. Vegetable oil based inks are somewhat more expensive than petroleum based inks, and price factors have limited the incentive for some manufacturers to use vegetable oil based inks.

2. Drying speed is slow. With current technology, petroleum distillates in ink formulations cannot be completely replaced with vegetable oils due to limitations in the drying properties of vegetable oil based inks. Therefore, the primary purpose of research and development in this area is to ensure the maximum content of vegetable oils in printing inks that meet high quality and performance.

3. The application is narrow. Not all types of printing inks can be applied well to vegetable oil based inks. For volatile dry inks, because the binders are required to be volatile, the vegetable oil-based inks have a high boiling point and are non-volatile solvents, limiting the use of vegetable inks. Therefore, how to expand the application range of vegetable oil-based ink is also an urgent problem to be solved.

4. other factors. The people's awareness of green production is not strong, they do not have enough enthusiasm for green products, the state's support for green production companies is not enough, and there is no corresponding policy tilt measures, making some manufacturers less active in producing green ink.

Third, the application prospects of vegetable ink

In recent years, environmental protection and health have become global issues. People have realized that traditional production models that disregard environmental considerations cannot sustain development and are harmful to the long-term interests of mankind. Human society has initially entered the “protection of nature, nature, and promotion of nature”. Sustainable development is the core green age. It is believed that under the call of the era, the development and application of "green ink" represented by plant ink will set off the climax of material application reform.

Source: 21st Century Fine Chemicals Network