Abstract: A method for forming a protective barrier layer between the active dye layer and the disc substrate during production of an optical memory disc is provided wherein a pre-treatment/pre-coat solution is applied to the disc substrate. This pre-treatment/pre-coat solution includes a surface modifier having an index of refraction approximately equal to that of the disc substrate. Surface modifiers utilized in this pre-treatment/pre-coat solution include poly vinyl alcohol, poly alpha methyl styrene, cellulose acetate, poly vinyl butyral and nitrocellulose.

Abstract: The invention pertains to an optical recording medium comprising a homeotropically oriented liquid crystalline polymer film having a T.sub.g between 75-100.degree. C. and a T.sub.c between 110-140.degree. C. and comprising at least one dichroic dye. This homeotropic orientation along with the presence of dichroic dye makes it possible to employ a different technique for writing out and reading data. For, in this case contrast is obtained by the dichroic dye contained in the film being aligned in the same direction as the mesogenic groups of the liquid crystalline polymer. In a virgin film the mesogenic groups, and hence the dichroic dye molecules, are oriented perpendicular to the film's surface, and there is only low absorption of the incident light by these molecules. By local heating or irradiation of the film (e.g., with a laser) the homeotropic orientation is converted to an isotropic one.

Abstract: An optical information recording medium provided on a substrate with a recording layer including a dye layer; wherein the dye layer contains a cyanine dye; and the recording layer enables a recording and reproducing to be effected with a laser beam having a wavelength falling within a range of 620 nm to 690 nm; a refractive index "n" of the recording layer being in a range of 1.6 to 4.0 and an extinction coefficient "k" of the a recording layer being in a range of 0.01 to 0.45 when the laser beam having the wavelength is applied thereto; and the recording layer exhibiting a maximum absorption peak wavelength and a second largest absorption peak wavelength falling within a range of 500 nm to 655 nm as measured by means of a visible ultraviolet spectrometer. The dye may be a trimethine-base cyanine dye.

Abstract: In the optical recording medium including a substrate having pregrooves, and a metal recording layer, a buffering layer, a reflecting layer and a protecting layer which are sequentially stacked on the substrate, wherein the buffering layer is formed of an organic material having a low light absorption with respect to a laser beam of 600.about.800 nm, such that light absorption (k) is less than or equal to 1.0 at 650 nm and the light absorption (k) is less than or equal to 0.1 at 780 nm. Therefore, the optical recording medium can be compatible with a compact disc (CD) and have a high reflectivity at longer wavelength than 600 nm.

Abstract: A dye composition for use in optical recording media, comprising at least one cyanine dye having an anion selected from the group consisting of thiocyanate, lactate, hypophosphite, tetracyanonickelate, selenocyanate, trifluromethanesulfonate, ferricyanide, 4-hydroxybutyrate, nitrite, 2-(3',5'-dimethyl-2'-hydroxyphenyl)-2H-benztriazole-4-sulfonate, 1,2-napthoquinone-2-diazide-5-sulfonate and picrate and preferably dissolved in ethyl lactate.

Abstract: A writable compact disk has a plastic substrate, a recording layer, a reflecting layer, and a protective overcoat, the reflecting layer is comprised of a silver-palladium alloy, a silver-copper alloy, or a silver-palladium-copper alloy. By maintaining the palladium component of the alloy less that 15 at. % and the copper component of the alloy less than 30 at. %, the reflectance of the reflecting layer can be similar to the typical gold reflecting layer while jitter and NORP levels can be reduced for illumination power levels exceeding the power normally used to write on the recording layer.

Abstract: 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.

Abstract: A metallic backing layer such as steel covered by a functional layer of AlSn, AlPb, CuPb, CuSn or CuZn, applied by spraying in air, and a softer covering layer applied to the functional layer by chemical or electrolytic deposition exhibits improved corrosion resistance, running-in behavior and conformability.

Abstract: An optical information recording medium which records at shorter laser wavelengths and has excellent light resistance and archival stability includes a supporting substrate and a recording layer coated on the substrate. The recording layer includes a metal chelated azo compound, the azo compound having the general formula (I): ##STR1## wherein X is NR.sup.6 group, oxygen or sulphur, wherein R.sup.6 is hydrogen or alkyl; Y is hydroxy, carboxy, or carbamoyl; each of R.sup.1 -R.sup.5 is independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted alkenyl, alkoxy, amino, halogen, nitro, cyano, trifluoromethyl, or carboxy, with the proviso that all of R.sup.1 -R.sup.5 are not simultaneously hydrogen; and the metal is a metal ion of Groups 3-12 of the Periodic Table.

Abstract: The present invention discloses an optical recording element having, in the following order, a transparent substrate, a recording layer and a light reflecting layer wherein the recording layer(A) has a real refractive index (N) at 780 nm not less than 1.8 and an imaginary part (k) is not greater than 0.15;(B) comprises a polymeric cyanine dye that (i) has both a weight-average molecular weight greater than 50,000 and a glass transition temperature (Tg) of less than 150.degree. C.; or (ii) has either (a) a weight-average molecular weight greater than 50,000 or (b) a glass transition temperature (Tg) of less than 150.degree. C.; and(C) a thickness greater than 200 nm.

Abstract: The present invention is in the field of optical recording media, and is directed to an optical recording medium which comprises the following layers;a) a grooved transparent substrate (1), superposed byb) a recording layer comprising a partial mirror (2) of a material having a high complex index of refraction which is not within the pentagon defined by the vertices 7.15 - i3.93, 7.15 - i5.85, 8.96 - 6.28, 9.56 - i5.90, and 8.14 - i3.77 in the n,k plane, superposed by a buffer layer (3) comprising a nonliquid-crystalline high-molecular weight material and optionally a dye, superposed by a thick reflective layer (4), together forming a Fabry-Perot wherein the thickness (d) of the buffer layer within the grooves is set so that the reflection of the medium is in the high reflective state, optionally superposed byc) a protective coating (5).By virtue of the partial mirror, the buffer layer, and the thick reflective layer a Fabry-Perot etalon is created.

Abstract: An optical recording element is disclosed. The element has a transparent substrate and on the surface of said substrate, a recording layer and a light reflecting layer wherein recording layer comprises a mixture of a metallized formazan dye and cyanine dye and the unrecorded layer is such that the real part of the refractive (n) at 780 nm is greater than 1.8 and the imaginary part (k) is less than 0.15. The metallized formazan dye has a k value of 0.03 to 0.07.

Abstract: An electrical conductor has a copper base substrate coated with a tin base coating layer. To inhibit the diffusion of copper from the substrate into the coating layer and the consequential formation of a brittle tin/copper intermetallic, a barrier layer is interposed between the substrate and the coating layer. This barrier layer contains from 20% to 40%, by weight, of nickel and is preferably predominantly comprised of copper. In one embodiment, an intermetallic layer selected from the group (Cu--Ni).sub.3 Sn, (Cu--Ni).sub.6 Sn.sub.5, Cu.sub.3 Sn, Cu.sub.6 Sn.sub.5 is disposed between the barrier layer and the tin base coating layer.

Abstract: An information recording medium, a storage case for storing an information recording medium, or a sheet for use with an information recording medium, has a light-emitting area coated with a phosphorescent paint, and a luminous paint area coated with a luminous paint for emitting exciting light to stimulate the light-emitting area to emit light, the luminous paint area being disposed adjacent to or on the light-emitting area.

Abstract: The present invention relates to a recording member having an inherent optical absorption wavelength range and a property of changing optical absorption spectral characteristics before and after the absorption of light to record informations by absorbing a light within the optical absorption wavelength range. In order to shift the wavelength range of this optical absorption spectrum toward longer wavelengths, at least one kind of substituents having a .pi. electron system, an electron donative property or an electron acceptive property is used as a substituent of a molecule constructing the recording member in an optical recording material. Such an optical recording material can be used in memories in the computer system and the like.

Abstract: A desired writable optical data recording medium has a transparent substrate 1 where a side wall of a recess is connected to a land surface by a curved surface. A data recording portion of a dye material may be placed only in recesses of a pre-formatted pattern on a transparent substrate, and a reflective layer may be formed on the data recording portion and on the exposed land area between neighboring recesses. The medium can show reflectivity of not less than 65% on reproduction and reduce the cost for manufacturing thereof.

Abstract: A recordable optical disk including a transparent substrate; a recording layer formed over the substrate; a reflective layer formed over the recording layer; and a thin metallic interlayer formed on the recording layer at the interface between the reflective layer and the recording layer wherein the thin metal interlayer includes materials selected from the group consisting of Pd, Ni, Sn, Au, In, Te, Si, Ge, and alloys thereof, the interlayer being selected so as to improve the optical disk recording stability without significantly affecting the reflection of a recording light beam passing through the substrate and the recording layer and which is reflected by the reflective layer.

Abstract: An optical information recording medium includes a substrate, and a light absorption layer formed thereon which includes a phthalocyanine compound (I) having a thermal decomposition temperature in a range of 250.degree. C. to 350.degree. C., measured by thermogravimetry with a temperature elevation rate of 10.degree. C. and a phthalocyanine compound (II) having a thermal decomposition temperature in a range of 350.degree. C. to 450.degree. C., measured by thermogravimetry with a temperature elevation rate of 10.degree. C. This optical information recording medium can be produced by providing the light absorption layer, directly or via an intermediate layer, on a substrate with information pits and/or guide grooves being on the surface thereof by film formation coating, providing a light reflection layer, directly or via an intermediate layer, on the light absorption layer by vacuum film formation, and providing a protective layer on the light reflection layer.

Abstract: A recordable optical disk including a transparent substrate; a recording layer formed over the substrate; a reflective layer formed over the recording layer; and a thin dielectric interlayer formed on the recording layer at the interface between the reflective layer and the recording layer wherein the thin dielectric interlayer includes materials selected from the group consisting of Ge--C--H, Si--N and InSnSb--O, the interlayer being selected so as to improve the optical disk recording stability without significantly affecting the reflection of a recording light beam passing through the substrate and the recording layer and which is reflected by the reflective layer.

Abstract: An information recording medium composed of 1) a transparent support, 2) a recording layer which is composed of an organic dye and an organic oxidizing agent having a reduction potential on the side nobler than -0.2, and 3) a light-reflecting layer on the recording layer shows improved light-resistance and endurance as well as good recording and reproducing characteristics.

Abstract: 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.

Abstract: A dye mixture having, at 780 nm, a real refractive index not less than 1.8, and an imaginary part not greater than 0.15 and comprising (a) a tetra dye having a metallized azo dianionic dye with a cationic dye counterion and (b) at least one other dye having the structure according to formula I: ##STR1## wherein: A may be equal to or different from A.sup.1, in which each represents an aryl group having 6 to 10 carbon atoms;B may be equal to or different from B.sup.1, in which each ##STR2## R and R.sup.1 represent an alkyl group of C.sub.1 -C.sub.10 or an aryl group having 6 to 10 carbon atoms; andX represents halide, ClO.sub.4, BF.sub.4, PF.sub.6, tosylate and RCOO.

Abstract: An optical recording medium comprising a substrate, a reflecting layer and a recording layer, which recording layer consists essentially of one or more than one dye of formula (I) or chlorination or bromation products thereof ##STR1## wherein R.sub.1 and R.sub.2 are each independently of the other C.sub.1 -C.sub.8 alkyl or C.sub.2 -C.sub.8 alkenyl;R.sub.3, R.sub.6, R.sub.9 and R.sub.12 are hydrogen, halogen, CN, CHO, C.sub.1 -C.sub.8 alkyl or unsubstituted or substituted C.sub.6 -C.sub.14 aryl;R.sub.4, R.sub.5, R.sub.7, R.sub.8, R.sub.10 and R.sub.11 are hydrogen, halogen, NO.sub.2, CHO, COOR.sub.13, CONR.sub.14 R.sub.15, CN or unsubstituted or substituted C.sub.1 -C.sub.8 alkyl or C.sub.2 -C.sub.8 alkenyl;or R.sub.4 and R.sub.5, R.sub.7 and R.sub.8 and/or R.sub.10 and R.sub.11 together are an unsubstituted or substituted 1,4-buta-1,3-dienylene, 2-buten-1,4-diylidene, 1,3-propylene or 1,4-butylene bridge, so as to form, optionally together with the shared C--C or C.dbd.

Abstract: Disclosed are a composite material having an anti-wear property and a process for producing the same. The composite material includes a matrix of a low melting point Sn alloy having a melting point of from 80.degree. to 280.degree. C., and metallic dispersing particles dispersed in the matrix in an amount of from 10 to 50% by volume. When the composite material is utilized to make a rough mold for preparing a prototype, it sharply improves the anti-wear property of the rough mold, and it can be re-used for a plurality of times without adversely affecting the sharply improved anti-wear property. The composite material provides the advantages effect best when the metallic dispersing particles are Fe-C alloy dispersing particles and/or Fe-W-C alloy dispersing particles which were subjected to a surface treatment including an Sn or Ni electroplating followed by a ZnCl.sub.2 .cndot.NH.sub.4 Cl flux depositing.

Abstract: 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.

Abstract: The invention relates to an optical recording medium comprising a substrate, a reflecting layer and a recording layer, which recording layer consists essentially of a dye of the formula (I), ##STR1## in which R.sub.1 and R.sub.6 are hydrogen or unsubstituted or substituted alkyl, alkenyl, alkynyl, aralkyl or aryl,R.sub.6 and R.sub.7 are unsubstituted or substituted alkyl, alkenyl, alkynyl, aralky or aryl,R.sub.3, R.sub.4, R.sub.8 and R.sub.9 are hydrogen, halogen, OR.sub.17, SR.sub.17, NR.sub.18 R.sub.19, NO.sub.2, alkyl, alkenyl or Alkynyl,R.sub.5 and R.sub.10 are hydrogen, halogen, OR.sub.17, SR.sub.17, NO.sub.2, NR.sub.18 R.sub.19 or unsubstituted or substituted alkyl, alkenyl, alkynyl or aralkyl, andR.sub.11 is hydrogen, (CH.sub.2).sub.1-10 COO.sup.-, (CH.sub.2).sub.1-10 COOR.sub.

Abstract: A recordable compact disc comprises a 0.6 millimeter clear plastic or glass substrate on which is grown a thin-film image layer having several distinct recording planes. Each recording plane is separated from the next by a clear plastic layer. Each recording plane includes an organic dye layer in combination with another clear layer that has a different index of refraction. Different color dyes are used for each recording plane.A method for storing and reading data to and from a multilayer recordable compact disc with different color dye layers uses high powered color lasers to write each recording plane and low powered monochromatic reading lasers that are sensitive to the constructive and destructive light interference effects caused by micron variations in the clear plastic layers in each recording plane. The micron variations used for each recording plane are unique and chosen along with the monochromatic reading laser colors to have minimal crosstalk between recording-plane data channels.

Abstract: The present invention is relative to an optical information recording medium having a reflective layer for reading out information signals by an optical technique. The optical information recording medium is formed as a plastic substrate. According to the present invention, the substrate is colored by admixture of a dyestuff for enabling instant judgment by the visual sense of the operator as to the contents of the optical information recording medium, for example, as to if the contents of the recording medium is a game program or the music information. If impurities such as dyestuffs are admixed, the optical system of the readout device is usually affected thus raising readout difficulties. Such ill effects on the optical system may be eliminated by setting the particle size of the dyestuff so as to be 50 .mu.m or less.

Abstract: This invention provides a rust-proofed steel sheet for a fuel tank including an alloy layer containing at least one of Ni, Fe, Zn and Sn and deposited on the surface of a steel sheet to a thickness of 2 .mu.m per surface, and a Sn--Zn alloy plating layer consisting of 40 to 99 wt % of Sn and the balance of iron, containing not greater than 20 crystals/0.25 mm.sup.2 of zinc crystals having a major diameter of not greater than 250 .mu.m and deposited on the alloy layer to a thickness of 2 to 50 .mu.m per surface. The to-be-plated steel sheet to which the plating layer is applied has a composition consisting of C.ltoreq.0.1%, Si.ltoreq.0.1%, Mn: 0.05 to 1.2%, P.ltoreq.0.040%, Al<0.1% and if necessary, at least one of B, Ti, Nb and Cr, and the balance of Fe and unavoidable impurities. This invention provides also a production method of a rust-proofing steel sheet for a fuel tank comprising the steps of applying Ni--Fe type pre-plating to an annealed steel sheet in a quantity of 0.1 to 3.0 g/m.sup.

Abstract: There is disclosed a recordable optical element that includes a polymeric dye. The element has a transparent substrate and on the surface of the substrate, a polymeric dye containing recording layer and a light reflective layer. The improvement is that polymeric dyes are used in the element, which improve the recording layer's cohesion and the adhesion to the substrate and the reflective layer.

Abstract: An optical recording material of the following formula (1) and an optical recording medium excellent in recording sensitivity, light resistance and durability, having a recording layer containing the material,the formula (1), ##STR1## wherein each of X.sub.1 to X.sub.4 is a hydrogen atom, an alkyl group, an aryl group, an alicyclic residue, an aralkyl group, a heterocyclic ring, an alkoxy group, an aryloxy group or an alkylthio group, each of Y.sub.1 to Y.sub.4 is a hydrogen atom, a halogen atom, a nitro group, a phthalimidemethyl group or a sulfoneamide group, each of R.sub.1 and R.sub.2 is a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkylamino group, a dialkylamino group, an arylamino group or a diarylamio group, M is Al, Ga, In, Si, Ge or Sn, Z is an azo compound, an anthraquinone compound or a metal complex compound, n.sub.1 to n.sub.4 are 1 to 4, m.sub.1 to m.sub.

Abstract: The surface of a lining member 3 is formed with a multiplicity of uneven surfaces 3a. The entire surface of the lining member 3 is coated by an intermediate layer 4 which comprises Ni. The surface of the intermediate layer 4 is additionally coated by an overlay layer 5 which comprises an Sn alloy. The lining member 3 has a surface roughness t.sub.1, as a result of forming the uneven surfaces 3a, which is chosen to be in a range from 2 to 8 .mu.mRz, and a thickness t.sub.2 of the intermediate layer 4 is chosen to be in a range from 0.01 to 0.6 .mu.m. When a sliding bearing 1 is heated, the overlay layer 5 and the intermediate layer 4 chemically react with each other to produce an Sn--Ni compound. As the overlay layer 5 becomes abraded, the Sn--Ni compound 6 will be exposed on the sliding contact surface. However, the described choice prevents the Sn--Ni compound from being exposed across the entire region of the sliding contact surface, thus improving the anti-seizure resistance of the sliding bearing 1.

Abstract: The present invention is directed to a dye composition for use in CD-R recording media and having reduced wavelength dependence of the dye layer absorption, comprising:(1) a first cyanine dye having a peak absorption wavelength in the solid film form in the range of about 690 nm to about 730 nm, the amount of said first cyanine dye is about 90% to about 30% by weight, based on the total weight of the solid components in said dye composition; and(2) at least one noncyanine dye having a peak absorption wavelength in the range of about 900 nm to about 1200 nm, each noncyanine dye having an absorption coefficient greater than 30,000 cm.sup.-1 and said amount of noncyanine dye is about 10% to about 40% by weight, based on the total weight of the solid components in said dye composition. The invention is also directed to a recordable medium coated with the above dye composition, and a recording mechanism implementing the above dye composition.

Abstract: It is an object of the present invention to increase an amount of information recorded on an optical disk having at least two information recording layers. An optical disk having a plurality of information recording layers according to the present invention includes a transparent substrate, a transparent layer and at least two information recording layers formed on the transparent substrate. The information recording layers are provided so as to sandwich the transparent layer. At least one of the information recording layers has a transmittance varying layer. The transmittance varying layer is made of a material whose transmittance is changed at a predetermined temperature as a threshold value. The transmittance varying layer is made of a phase change material. The threshold value is within the temperature range from 700.degree. to 500.degree.. Crystallization speed of the transmittance varying layer is equal to or slower than 500 ns.

Abstract: There is disclosed a recordable optical element that includes a polymeric dye. The element has a transparent substrate and on the surface of the substrate, a polymeric dye containing recording layer and a light reflective layer. The improvement is that polymeric dyes are used in the element, which improve the recording layer's cohesion and the adhesion to the substrate and the reflective layer.

Abstract: A composite copper alloy bearing is provided with a backing metal layer, an intermediate layer of Cu--Pb alloy, and a surface layer of Al--Sn alloy. A thickness of the surface layer is not less than either larger value selected between 0.06 mm and a value 0.2 times the sum of thicknesses of the intermediate layer and the surface layer but not more than a value 0.5 times the sum of the thicknesses of the intermediate layer and the surface layer. With this construction, the surface layer exhibits excellent sliding properties while the intermediate layer maintains high conformability, and therefore there can be provided the composite copper alloy bearing which has high fatigue strength particularly even in a case where a shaft susceptible to misalignment is used.

Abstract: An optical recording medium has deposited on a substrate a recording layer incorporating therein a cyanine dye, preferably an indoline dye, and optionally incorporating therein an autoxidizable compound or a thermoplastic resin and/or a singlet oxygen quencher.

Abstract: A mixture of low k metallized formazan dye with symmetrical and unsymmetrical cyanine dyes is disclosed. The mixture is useful in optical recording layers of optical recording elements.

Abstract: In a recordable/replayable optical recording medium having a thin metal recording layer and an optical recording method therefor, the optical recording medium includes a substrate, a thin metal film formed on the substrate, a reflective layer arranged on the thin metal film, a buffering layer interposed between the thin metal film deformed by heat, and a protecting layer for protecting the deposited layers. Recording is facilitated by adopting a buffering layer and compatibility with conventional CD players is possible. Since expensive organic dyes are not necessary, manufacturing costs can be reduced and productivity can be greatly improved.

Abstract: A ship that is partially hot-tin-plated with at least one metallic coating track extending in longitudinal direction on or both of its upper and lower surfaces and/or along one or both side edges. An intermetallic phase exists between the ship material and the coated track. In order to satisfy the many uses for partially tin-plated ships in the electronics and electrotechnical fields and for the manufacture of semiconductor elements, the track, viewed in longitudinal direction, is interrupted according to the invention at regular and/or irregular spacings (A.sub.1, A.sub.2, A.sub.3 . . . ).

Abstract: To provide a reversible multi-color thermal recording medium or a reversible multi-color optical recording medium which uses novel urea and thiourea derivatives and has excellent heat resistance.A reversible multi-color thermal recording medium having an irreversible thermal composition containing a colorless or pale basic achromatic dye and an organic color developer as main components and a reversible thermal composition containing a colorless or pale basic achromatic dye and an organic color developer as main components laminated on a support, the organic color developer contained in the irreversible thermal composition being an irreversible heat-resistant color developer and the organic color developer contained in the reversible thermal composition being a reversible heat-resistant color developer.

Abstract: Chemical substances are provided which exhibit thermally induced spin transitions between two stable spin states at ambient temperature, said transitions being associated with a hysteresis phenomenon and resulting in an abrupt variation of the color of the molecules for realizing a medium for storing, processing and/or displaying information by way of thermal writing, optical reading and thermal erasing, a particular embodiment of such a medium comprising at least a layer of chemical substances including a lattice with a molecule comprising a metallic element Fe.sub.(II), or Fe.sub.(III) or Co.sub.(II) associated with at least one ligand chosen from the substituted triazoles which are defined by the formula: ##STR1## in which R is H or an alkyl C.sub.n H.sub.2n+1 or R is an amine group NL.sub.2 where L is H and an alkyl radical, said molecule also comprising one or several anions chosen, for example, from BF.sub.4.sup.-, ClO.sub.4.sup.-, Br.sup.-, Cl.sup.

Abstract: An optical information medium providing a protective layer above an optically transparent substrate to protect a recording part, and can record information which is optically readable by means of laser beam. An aqueous printing ink-fixable, hydrophilic resin film is formed on the protective layer. Given letters and patterns can be printed easily and satisfactorily. Such letters and patterns are printable by means of, for example, an ink jet printer.

Abstract: An optical recording medium of a multi-layer type comprises; a single or plural spacer layers each carrying pits and/or grooves; a single or plural reflective layers layered on the spacer layers; and a silane coupling treatment layer formed between the reflective layer and the spacer layer adjacent to each other.

Abstract: A composite magneto-optical information recording medium comprising a substrate (1) and a composite magneto-optical recording layer deposited on said substrate. The composite magneto-optical recording layer comprises a magneto-optical layer (2), a metallic layer (3) and an electron transition layer (4) which exhibits transition of electrons in a wavelength range of a laser beam used for recording and/or regenerating information, the three layer being layered successively in this order so that said laser beam (L) impinges on the side of said magneto-optical layer (2).

Abstract: An optical disk records digital information in optically-reflective layers that each vary in thickness between constructive interference of a monochromatic light and destructive interference of the said monochromatic light. The difference in the intensity of a reflected light beam subjected to interferometric constructive and destructive interference is used to communicate digital data from the optically-reflective layers and a detector. The optical disk provides for multiple layers of digital information that are tuned for interferometric response at correspondingly different monochromatic wavelengths of light. Another embodiment of the present invention is a mass-production process for making such an interferometric optical disk. Another embodiment of the present invention is a variation that includes layers that are emitting or absorbing depending on dopants.

Abstract: A mixture of symmetrical and unsymmetrical nickel formazan dyes is disclosed. Optical recording elements containing the mixture are also disclosed.

Abstract: A near infrared light-absorbing dye comprising phthalocyanine compounds represented by the following formula (2): ##STR1## wherein in formula (2), M is two hydrogen atoms, a divalent metallic atom, a trivalent monosubstituted metallic atom, a tetravalent disubstituted metallic atom or an oxymetal atom, and L.sup.1, L.sup.2, L.sup.3 and L.sup.4 are each independently formula (a) or (b), ##STR2## in the formula (a) or (b), R.sup.1 and R.sup.3 are each a substituted or unsubstituted alkyl group, and R.sup.2 is a straight chain or branched halogenated alkyl or alkenyl group having 3 to 10 carbon atoms,X is a chlorine, bromine or iodine atom, and m is an integer of 1 to 12, provided that formula (2) represents a mixture of L.sup.1 =L.sup.2 =L.sup.3 =L.sup.4 =formula (a), L.sup.1 =L.sup.2 =L.sup.4 =formula (a) and L.sup.3 =formula (b), L.sup.1 =L.sup.4 =formula (a) and L.sup.2 =L.sup.3 =formula (b), L.sup.1 =L.sup.3 =formula (a) and L.sup.2 =L.sup.4 =formula (b), L.sup.1 =formula (a) and L.sup.2 =L.sup.3 =L.sup.

Abstract: A recording layer contains a dye A having a complex index of refraction at 780 nm whose real part n is 1.8-2.8 and imaginary part k is up to 0.15 and forming a thin film exhibiting an absorption spectrum whose half-value width is up to 170 nm and a dye B having a complex index of refraction at 630 nm or 650 nm whose real part n is 1.8-2.8 and imaginary part k is up to 0.2. An optical recording medium capable of writing and reading in a conventional wavelength region of about 780 nm and a shorter wavelength region of about 630 to 680 nm is obtained.

Abstract: An optical element is provide which has a durability enhancing layer. There is provided an optical disk comprising a support having on one surface thereof, in order:a) a recording layer such that said recording layer does not cover the entire surface of said disk but leaves an annular portion at the outer diameter;b) a reflective layer such that said reflective layer does not cover the entire surface of said disk but leaves an annular portion at the outer diameter;c) a first protective layer having a thickness between about 2-20 .mu.m, said protective layer being of a material having good adhesion to said support and covering a portion of the surface of said disk having said reflective layer, including at least a portion of said annular portion;d) a second protective layer having a thickness of at least about 3 .mu.m, said second layer covering at least the area of said surface having the reflective layer and having good adhesion to said first protective layer.