Mitsubishi Gas Chemical Company, Inc.

Hoya Corporation

Shigeki Shimokawa

Yoshio Maeda

Yasuo Sugihara

Yoshitsugu Minamikawa

Seishi Murakami

Proposed is an improvement in a method for the preparation of an enriched and purified aqueous hydrogen peroxide solution from a crude aqueous hydrogen peroxide solution comprising the steps of evaporating the crude aqueous hydrogen peroxide solution in an evaporator into vapor with accompanying liquid in the form of a mist, separating the vapor from the mist of liquid in a gas-liquid separator and subjecting the vapor to fractionating distillation in a fractionating distillation column in order to greatly upgrade the product solution relative to the impurity content. The improvement is achieved by subjecting the crude aqueous hydrogen peroxide solution, prior to introduction into the evaporator, to a contacting treatment with a porous synthetic adsorbent resin to remove organic impurities from the crude aqueous hydrogen peroxide solution to such an extent that the crude aqueous hydrogen peroxide solution after the contacting treatment contains organic impurities in an amount not exceeding 50 ppm by weight calculated as organic carbon. Although the mechanism is not well understood, the preliminary removal of organic impurities from the crude aqueous hydrogen peroxide solution has an effect of greatly increasing the efficiency of gas-liquid separation of the vapor accompanied by a mist of liquid in the gas-liquid separator to decrease the amount of contaminant impurities introduced into the distillation column as carried by the mist.

Method for enrichment and purification of aqueous hydrogen peroxide

The peeling solution for photo- or electron beam-sensitive resin according to the present invention consists of an aqueous solution comprising hydrogen peroxide and a compound represented by the general formula (I) ##STR1## wherein R.sub.1 is H or an alkyl group of 1-2 carbon atoms, R.sub.2 is H or an alkyl group of 1-3 carbon atoms, and R.sub.3 is H or an alkyl group of 1-3 carbon atoms. The process for peeling off a photo- or electron beam-sensitive resin according to the present invention comprises a step of treating a photo- or electron beam-sensitive resin-coated substrate with a peeling solution for photo- or electron beam-sensitive resin cnsisting of an aqueous solution comprising hydrogen peroxide and a compound represented by the above general formula (I).

Peeling solution for photo- or electron beam-sensitive resin and process

The peeling solution for photo- or electron beam-sensitive resin according to the present invention consists of an aqueous solution consisting of hydrogen peroxide and a compound represented by the general formula (I) ##STR1## wherein R.sub.1 is H or an alkyl group of 1-2 carbon atoms, R.sub.2 is H or an alkyl group of 1-3 carbon atoms, and R.sub.3 is H or an alkyl group of 1-3 carbon atoms.

Peeling solution for photo- or electron beam-sensitive resin

A method for purifying an impure aqueous hydrogen peroxide solution, which comprises passing an impure aqueous hydrogen peroxide solution through

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Yokkaichi, Japan

Shigeki Shimokawa