Oil-Based White Ink

An oil-based white ink for an inkjet formulation has been described with excellent storage stability (2). 

When a white ink is printed on a black or transparent recording material with low brightness, highly visible printed matter can be provided. The white ink is also effective for marking various products. When a color ink other than the white ink is printed on the recording material, a sharp printing cannot be reproduced due to the influence of a color of a substrate. In order to overcome this 

The resin is highly compatible with a glycol ether dialkyl ether. Thus, a mixed solution composed of the acrylic resin and the glycol ether can easily be prepared. The acrylic resin is produced from alkyl methacrylates, aralkyl methacrylates, alkoxyalkyl methacrylates, hydroxyalkyl methacrylates, methacrylic acid, or dialkyl-aminoalkyl methacrylates. A particularly preferred copolymer is a copolymer of methyl methacrylate and methacrylic acid. 

Preparation 5-1 A mixture of 198 g of methyl methacrylate, 2 of methacrylic add, and 8 y of ferf-butylperoxy-2-ethylhexanoate is added drop-wise to 300 g of diethylene glycol diethyl ether kept at 100°C over a period of 1.5 h. After the completion of the dropwise addition, a reaction is allowed to proceed at 100°C for 2 h. The reaction solution is then cooled to give a colorless and transparent solution of a copolymer of methyl methacrylate with methacrylic acid. The glass transition of the copolymer is 105°C. 

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