China is Going Green in Sheetfed Offset Inks

By Jack Baarends, Bloit Printing Ink | 01.20.11

China has been very active in developing clean energy

For decades, China’s development has centered on GDP growth, with industrialized countries being the role model. It’s time to stop doing that and to check a new path and pace of growth.Nowadays, China wants to succeed in balancing their economical growth with ecological conservation and people’s well-being.

China dominated the world’s clean energy market in 2009, and is poised for further growth. That precisely is why the world is looking at China to take steps that can really change the game. What the world needs now are major shifts, not marginal changes. China has been very active in developing clean energy. Chinese Premier Wen Jiaboa and chief climate envoy Huang Huikang have reiterated the country’s determination to go green. China pushes to develop a green economy and wants to become the leading country in “green” developments. The government has initiatives for clean energy, reduction of emissions, pollution and waste, and development of clean technologies, for example.

In printing and printing ink. the government has taken several initiatives, e.g. to reduce or even to ban toluene for flexo and gravure inks.Additionally, it made a list of 17 chemicals that are permitted at very low levels (ppm) in inks and overprints for cigarettes packaging. This means that styrene and styrene acrylics are out, and acrylics could be phased out as well.

In offset printing, the government had encouraged the use of soya-based inks for a long time.Soya-based inks are thought of as being “green,” and inks possessing a minimum level of soya content can get the Soy label, as they have in the U.S. To have the Soy Label in China, sheetfed inks have to contain > 20 % soya bean oil. For heatset inks, this is >7 % and for coldset inks> 30 %.

However, soya inks cannot be considered as really green, as they contain petroleum distillates and phenolic modified resins. In China, soya-based inks are dying not only because they are not truly environmentally friendly, but also their performance is not that great. Soy inks have normally rather high tack and are slower in setting.

Additionally, ink companies are working on products with low or no VOCs. The non-VOC inks are taking off in China, but the same can be said for these inks as is said about the soy-containing inks.They are a lower performance product with slower setting and higher tack values. These inks are also based on phenolic modified resins to obtain sufficient performance.

Why do I mention phenolic modified resins?

Bloit Ink took the initiative to develop the greenest inks possible for sheetfed printing. Working with five of the green principals, new sheetfed inks have now been developed. Why are they “the greenest”?

• Non-VOC:No mineral distillate has been used. As “solvents,” only vegetable oils and ester-solvents have been used. During printing there was an obvious improved smell and odor of the ink and in the printing house. Less eye irritation for the people around the printing press has been observed.

• Very High BRC (Bio-Renewable Content):A maximum of 75 to 80% BRC (depending on the color of the ink) has been reached. As much as possible, raw materials from renewable resources have been used. Vegetable oils, fatty acids and rosin (from gum or tall oil) are renewable and used in the alkyd resins.

• Phenolic-/Formaldehyde-Free Resins: Alkylphenols, such as nonylphenol – and formaldehyde – are hazardous chemicals used in resins, the so-called phenolic modified resins. Phenolic modified resins are considered safe by consumer standards, but they are not clean from a chemistry supply chain perspective.

• Improved Degradation and De-inking: By using rosin resins that are non-phenolic modified, better biodegradability and improved recycling of printed paper can be achieved.

• Cobalt-Free Driers: Cobalt driers have been replaced by cobalt-free driers. To make these inks even “Super Green,” other “hazardous” additives are not used. For example, to increase open time of the inks, hydroquinone is typically used.We achieve open time without using hydroquinone, nor any hazardous alternatives to hydroquinone.

During the development of these inks, performance targets were set in the following areas: tack, yield value, flow, setting, gloss, color density and emulsification behaviour.It was expected that our inks should meet at least the same values as mineral oil-containing inks based on phenolic modified resins. Bloit Ink has succeeded in developing inks with low tack, high yield value, high flow, fast setting, high gloss, high color density and excellent water balance. Here is an overview on the comparative ink properties (Table 1).

Ink PropertiesOur “Green” Conventional
Ink MagentaInk Magenta

Tack 9.89.5-10
Viscosity1.4 Pa.sAbt. 40 Pa.s
Yield Value 515 Pa >300 Pa
Shortness Ratio 10.8> 7.5
Flow37 mm35-38 mm
Setting 5’6-8’
Gloss67.6> 65
Color Density2.392.35
Rub resistanceGoodGood

Table 1: Overview on comparative ink properties between Bloit Ink and conventional ink.
This shows that the high performance of our inks is similar to that of conventional inks. Press trials showed excellent press performance.

The authorities are very pleased with this initiative. When we talk with them, they are very enthusiastic about the “green” initiatives we have taken.Their goal is to have all schoolbooks printed with the greenest ink within three years from now, starting with one-third of the books every year. Printers in China have shown great interest in this and are looking for greener inks.

China will continue to “go green” and Bloit Ink is very pleased to contribute to a cleaner sky, cleaner earth and healthier people.

Jack F. J. Baarends is a consultant for and served as technical director for Bloit Ink, Suzhou, China. He has more than 41 years of experience in polymer (resin, varnish, compound) technology and in the graphic arts industry. During his career, Mr. Baarends has been director of technical marketing, director of global technology and marketing, senior VP of global technology, technical director of research and development and commercial director for Asia-Pacific. He worked for Hexion Specialty Chemicals (before known as Lawter International, Eastman and Resolution Specialty Materials) and for Akzo Nobel Inks. Mr. Baarends has a degree in organic chemistry and in process chemistry.

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