Mitsui Toatsu Chemicals, Incorporated

Yamamoto Chemicals, Inc.

Mitsui Chemicals, Inc.

Hideki Umehara

Kenichi Sugimoto

Takeshi Tsuda

Sumio Hirose

Tsutami Misawa

Keisuke Takuma

Taizo Nishimoto

Yuji Inatomi

Hisato Itoh

Takahisa Oguchi

Ryu Oi

Tadashi Koike

Masatoshi Yanagimachi

Yoshiteru Taniguchi

Shin Aihara

Hisashi Tsukahara

Tomoyoshi Sasakawa

Kimiteru Tagawa

Jun Tokuhiro

Shigeo Kiba

Fujio Hayashi

Seiichi Takahashi

Satoru Suda

Noritoshi Utsuno

An optical information recording medium is here disclosed which comprises a transparent substrate, a recording layer comprising an organic dyestuff on which information can be written by a laser beam, a reflective layer and a protective layer formed in this order on the substrate, the aforesaid optical information recording medium being characterized by containing a pit-edge control agent for the formation of recording pits, particularly a dyestuff thermal decomposition accelerator in the recording layer. By the addition of the pit-edge control agent, deviation properties and jitter properties can be remarkably improved, whereby a CD-R medium having a low error rate and good recording properties can be provided. In consequence, stable compatibility with a commercial CD player can be secured.

Optical information recording medium and composition for optical information recording film

An optical recording medium having at least a recording layer and a reflective layer on a substrates, the said recording layer contains a dipyrromethene metal chelate compound obtained from a dipyrromethene compound represented by the general formula (1) and a metal ion: ##STR1## wherein R.sup.1 to R.sup.7 are defined in the specification.

Dipyrromethene metal chelate compounds

An optical recording medium having at least a recording layer and a reflective layer on a substrate. The recording layer contains a dipyrromethene metal chelate compound obtained from a dipyrromethene compound represented by the general formula (1) and a metal ion: ##STR1## wherein R.sup.1 to R.sup.7 are defined in the specification.

Optical recording medium

An optical information recording medium is here disclosed which comprises a transparent substrate, a recording layer comprising an organic dyestuff on which information can be written by a laser beam, a reflective layer and a protective layer formed in this order on the substrate, the aforesaid optical information recording medium being characterized by containing a pit.multidot.edge control agent for the formation of recording pits, particularly a dyestuff thermal decomposition accelerator in the recording layer. By the addition of the pit.multidot.edge control agent, deviation properties and jitter properties can be remarkably improved, whereby a CD-R medium having a low error rate and good recording properties can be provided. In consequence, stable compatibility with a commercial CD player can be secured.

Optical information recording medium and composition for optical

An optical recording medium comprising a recording layer, a light interference layer, a reflective layer and a protective layer that are laminated on a substrate, characterized in that said recording layer and said light interference layer comprise at least one organic dye, and that a light absorbent and/or a thermal decomposition promoter are/is added to said light interference layer, wherein the optical recording medium has compatibility that allows good recording and/or reproduction by using lasers of different two wavelength ranges and has good recording properties.

A phthalocyanine represented by the formula (1) ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is independently an alkyl group substituted by 0 to 5 halogen atoms and having 1 to 20 carbon atoms, an alkenyl group substituted by 0 to 5 halogen atoms and having 2 to 20 carbon atoms or an alkynyl group substituted by 0 to 5 halogen atoms and having 2 to 20 carbon atoms, and at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is substituted by the halogen atom; X is a halogen atom; each of k, l, m and n is independently a value of from 0 to 3; each of o, p, q and r is independently a value of 0, 1 or 2, and all of them are not 0 simultaneously; each sum of k and o, l and p, m and q, and n and r is independently in the range of from 0 to 4; Met is two hydrogen atoms, a di, monosubstituted tri, disubstituted ter metal atom or an oxymetal atom. The above phthalocyanins can be used to provide optical recording medium.

Phthalocyanine compound and optical recording medium containing it

Provided is an optical recording medium in which per-pits in a ROM area have a depth of 250 nm or more and 350 nm or less; pre-grooves between the pre-pits have a depth of 30 nm or more and 170 nm or less; wobbling tracks have an amplitude of 25 nm or more and 110 nm or less; the product of the depth of the pre-grooves between the pits and the wobble amplitude of the track is 3100 or more; and pre-grooves in a RAM area have a depth of 130 nm or more and 250 nm or less. The optical recording medium is a hybrid disk having such good signal characteristics as satisfying the Orange Book standards.

Optical recording media

The present invention relates to an optical recording medium having a recording layer, a reflective layer and a protective layer on a substrate, wherein a quinophthalone compound represented by the following formula (1) is contained in the above recording layer. The use of the quinophthalone compound or a mixture of the quinophthalone compound and a photoabsorbing compound having an absorption maximum in a wavelength falling in a range of 550 to 900 nm in the recording layer makes it possible to provide an interchangeable optical recording medium not only capable of recording and reproducing with a laser having a wavelength falling in a range of 480 to 600 nm, but is also capable of recording and reproducing with red lasers having wavelengths of 630 nm and 680 nm and a near infrared laser having a wavelength of 780 nm. ##STR1##

An optical recording medium has a recording layer, a reflective layer and a protective layer, all of which are arranged on a substrate. The recording layer contains a porphyrin compound represented by the following formula (1): ##STR1## wherein R.sub.1 to R.sub.8 independently represent a hydrogen atom, an alkyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylthio group or a halogen atom, R.sub.9 to R.sub.12 independently represent a hydrogen atom or an alkyl group, and X.sup.- represents an anion.

A phthalocyanine represented by the formula (1) ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is independently an alkyl group substituted by 0 to 5 halogen atoms and having 1 to 20 carbon atoms, an alkenyl group substituted by 0 to 5 halogen atoms and having 2 to 20 carbon atoms or an alkynyl group substituted by 0 to 5 halogen atoms and having 2 to 20 carbon atoms, and at least one of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 is substituted by the halogen atom; X is a halogen atom; each of k, l, m and n is independently a value of from 0 to 3; each of o, p, q and r is independently a value of 0, 1 or 2, and all of them are not 0 simultaneously; each sum of k and o, l and p, m and q, and n and r is independently in the range of from 0 to 4; Met is two hydrogen atoms, a divalent metal atom, a trivalent mono-substituted metal atom, a tetravalent di-substituted metal atom or an oxy-metal atom; an optical recording medium formed by adding this phthalocyanine to a recording layer; and a near infra-red absorbing agent comprising the phthalocyanine. The above-mentioned phthalocyanine can be used to provide the optical recording medium having excellent characteristics of reflectance, sensitivity, recording properties, stability to reproduction light, shelf stability and the like.

There is provided with an optical recording medium comprising at least a dye-containing recording layer and a reflective layer laminated on a transparent substrate in this order which has a reflectance of 65% or higher, measured through the substrate, to a light beam having a selected wavelength (.lambda.1) of from 770 to 830 nm and has a reflectance of 15% or higher to a light beam having a selected wavelength (.lambda.2) of from 630 to 690 nm and which is recordable and reproducible with a laser beam having the wavelength of .lambda.1 and being reproducible with a laser beam having the wavelength of .lambda.2. In addition, the recording layer has a dye A having the absorption maximum at the wavelength shorter than 630 nm mixed with a dye B having the absorption maximum at the wavelength of from 630 to 900 nm. Alternatively, an interference layer is provided along with the recording and reflective layers. The recording layer is based on a phthalocyanine dye while the interference layer is based on an inorganic dielectric, a polymer, or an azo dye. The requirements for the interference layer are also provided.

Optical recording media and a method of recording and reproducing

An optical information recording medium is here disclosed which comprises a transparent substrate, a recording layer comprising an organic dyestuff on which information can be written by a laser beam, a reflective layer and a protective layer formed in this order on the substrate, the aforesaid optical information recording medium being characterized by containing a pit.edge control agent for the formation of recording pits, particularly a dyestuff thermal decomposition accelerator in the recording layer. By the addition of the pit.edge control agent, deviation properties and jitter properties can be remarkably improved, whereby a CD-R medium having a low error rate and good recording properties can be provided. In consequence, stable compatibility with a commercial CD player can be secured.

The present invention provides a light-absorbing compound represented by the formula (I):

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Yokohama, Japan

Hideki Umehara