Yamamoto Chemicals, Inc.

Jun-ichi Taniguchi

Yojiro Kumagae

Shigeo Fujita

Hiroyuki Sasaki

Toshihiro Masaoka

Sayuri Wada

Bunji Sawano

Hiroshi Terao

Shinzo Nawamoto

A photothermal conversion material showing high sensitivity to the light of a semiconductor laser having an emission frequency band of 750 nm.about.900 nm with a high photothermal conversion efficiency and a planographic original plate fabricated by using the transducer are provided. This photothermal conversion material comprises a phthalocyanine compound of the following general formula (I) ##STR1## wherein R.sub.1 .about.R.sub.8 each represents alkyl or alkoxyalkyl; X.sub.1 .about.X.sub.8 each represents sulfur or NR.sub.9, where R.sub.9 is hydrogen or alkyl.

Photothermal conversion material

A phthalide compound of general formula (I) and a near infrared absorber and a recording material each utilizing the phthalide compound are disclosed. ##STR1## wherein ring A represents a substituent group of the following formula ##STR2## where the other substituents are as defined in the disclosure. The near infrared absorber and the recorded image on the recording material absorb strongly the near infrared region with no appreciable absorption in the visible region of the spectrum. The near infrared absorber is colorless or pale in color and yet highly capable of absorbing near infrared radiation. The recorded image on the recording material can hardly be read with the eye but can be read with the OCR. Moreover, the effect on the developed shade of any concomitant color former in a recording material is minimal.

Phthalide compound and a near infrared absorber and a recording material

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Osaka, Japan

Jun-ichi Taniguchi