Yamamoto Chemicals, Inc.

Sayuri Wada

Shigeo Fujita

Yojiro Kumagae

Mansuke Matsumoto

Keiki Chichiishi

Nobuaki Sasaki

Shuuichi Hashimoto

Shuichi Hashimoto

Hiroyuki Sasaki

Toshihiro Masaoka

Bunji Sawano

Jun-ichi Taniguchi

Shinzo Nawamoto

The invention provides novel compounds useful as intermediates for the production of polymethine compounds containing a desired counter ion with high purity and in high yields. Thus provided are polymethine ether compounds of the general formula (I) given below and a method of producing polymethine compounds which comprises bringing those compounds into contact with an acid. In the above formula, R represents an alkyl group, an alkoxyalkyl group or an aryl group which may optionally be substituted, Rand Reach independently represents a hydrogen atom, halogen atom, nitro group, alkyl group, alkoxyalkyl group, alkoxy group or alkoxyalkoxy group and Rand Rmay be bound to each other to form a ring; Rrepresents an alkyl group, which may optionally be substituted; L is an alkylene group required for the formation of a ring structure; and X represents a hydrogen atom, halogen atom, alkoxy group, aryloxy group, alkylthio group, arylthio group or substituted amino group.

Polymethine ether compounds

A novel nonsolvate-form crystal of polymethine compound is provided which has good stability in solution, shows a high gram extinction coefficient, is excellent in storage stability, is easy to handle and is highly sensitive to general-purpose semiconductor lasers. Thus is provided a nonsolvate-form crystal of polymethine compound of the formula (I) given below as well as a process for producing the nonsolvate-form crystal of polymethine compound of formula (I) which comprises reacting a polymethine ether compound of the formula (II) given below with hydrochloric acid or hydrobromic acid. (In the above formula, X represents Cl or Br.) (In the above formula, R represents an alkyl group, an alkoxyalkyl group or an optionally substituted aryl group.)

Nonsolvate-form crystal of polymethine compound and process for producing the same

Polymethine ethers

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

The improved two types of crystal modification of 2-m-toluidino-3-methyl-6-di-n-butylaminofluoran, as well as the crystalline toluene adduct thereof have high solubility in inner-phase solvent(s). Recording materials that use those compounds as electron donating color formers exhibit particularly good performance in various characteristics such as whiteness of the background, its storage stability, color rendition, sensitivity for color formation and image storage stability.

Crystal modifications of

The improved .beta.-type crystal modification of 2-(3-methylanilino)-3-methyl-6-diethylaminofluoran has high solubility in inner-phase solvents. The compound is very useful as a color former for pressure-sensitive recording materials and thermal recording materials. Recording materials that use this compound as color former exhibit good performance in various characteristics such as whiteness of the background, its storage stability, color rendition, sensitivity for color formation and color fastness of image.

Crystal modification of

The improved two types of crystal modification of 2-n-toluidino-3-methyl-6-di-n-butylaminofluoran, as well as the crystalline toluene adduct thereof have high solubility in inner-phase solvent(s). Recording materials that use those compounds as electron donating color formers exhibit particularly good performance in various characteristics such as whiteness of the background, its storage stability, color rendition, sensitivity for color formation and image storage stability.

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Osaka, Japan

Sayuri Wada