Mitsubishi Paper Mills Limited

Kirin Brewery Company, Limited

Yutaka Shimura

Shigetoshi Hiraishi

Mamoru Ishiguro

Susumu Yamanobe

Toshimitsu Nakajima

Naomu Ishiwaki

Microorganism cells such as Saccharomyces or Candida yeast cells are treated with an alkaline aqueous solution with heating and stirring or with a cell wall dissolving enzyme such as glucanase or mannase to obtain cells that function as microcapsules by rapidly taking up a large amount of hydrophobic liquid. Treatment with an alkaline aqueous solution is preferably carried out at a pH of at least 8 for at least 1 hour at a temperature of 20.degree.-100.degree. C. A preferred embodiment of enzyme treatment is with .beta.-1,3-glucanase for about 30 minutes to 5 hours at pH 4-9 at a temperature of 30.degree.-60.degree. C. The treatments dissolve cell walls of the yeast such that the walls still have sufficient strength for enclosing hydrophobic liquids.

Process for treating yeast with B-1, 3-glucanase to produce

There is disclosed a heat sensitive recording material comprising a color-forming agent consisting of an aromatic isocyanate compound and an imino compound, and a phenol compound; said recoridng material being excellent in storability of image and storability of non-image area as well.

Heat-sensitive recording material

The present invention provides a heat sensitive recording material which is less in fog in background area and has superior color toning effect with high image storage stability which contain a fluoran compound represented by the following formula in addition to an aromatic isocyanate compound and an imino compound having at least one &gt;C.dbd.NH group which forms color upon application of heat: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 each represents a hydrogen atom, a lower alkyl group, a cyclohexyl group or an allyl group and R.sub.4 and R.sub.5 each represents a hydrogen atom, a lower alkyl group, a phenyl group, a cyclohexyl group or an aralkyl group. This heat sensitive recording material may further contain a heat fusible substance and/or a phenol compound to further improve heat responsivity or anti-fogging properties of background portion.

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Tokyo, Japan

Yutaka Shimura