Thermal recording materials

Thermal recording materials consist of a heat-sensitive layer made by dispersing a leuco triphenylmethane dye and a phenol in a binder where the 

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Dextrin is extensively used in the manufacture of photosensitive materials (developers, thermal recording materials, optical information recording media, and photohardenable printing and transfers). Among other uses, dextrin diminishes the absorptivity and flabbiness of diazo copying... 

Inclusion of l,2-bis(l,3,5-thiadiazin-3-yl)- and l,2-bis(l,3,5-thiadiazin-5-yl)-ethanes is reported to improve the stability of thermal recording materials <86JAP(K)61202885>. 3,5-Dialkyl-5,6-dihydro-2/f-l,3,5-thiadiazine-4(3//)-thiones (251) have been used as rubber antiozonants <88EUP278890>. 

Benzofuranone (238) is part of a color developer for thermal recording materials which colors at higher temperature and are particularly good for multicolor recording. The compound is an alter-... 

Arai, N. Thermal recording material. Jpn. Kokai Tokkyo JP 61092892, 1986 Chem. Abstr. 1987,106, 11257. 

Usami, T. Shimomura, T. Thermal recording material containing dye-precursor-incorporated microcapsules and a dispersion of color developing base. Jpn. Kokai Tokkyo Koho JP 01145190, 1989 Chem. Abstr. 1990,112, 169163. 

Photocrosslinkable resins Thermal recording material Moldings, coatings, and adhesives Coatings, adhesives... 

Abe, Y Tsuchida, T. Omura, H. Thermal recording materials containing tetrazolium leuco dyes, reducing agents, and salts of basic organic compounds. Jpn. Kokai Tokkyo Koho. JP 04270684, 1992 Chem. Abstr. 1993, 118, 158046. 

Kanda, N. Nakamura, M. Thermal recording materials colored with specific colorant. Jpn. Kokai Tokkyo Koho JP 06092027, 1994 Chem. Abstr. 1994, 121, 145456. 

Mitsubishi Paper Mills, Ltd. Multicolor thermal recording materials. Jpn. Tokkyo Koho JP 55036519,1980. 

For thermographic recording materials, thermochromic properties of the spiroindolino- and spirobenzothiazolino-benzopyrans have been utilized. As an example, thermal paper patented by National Cash Register38 can be cited. In this paper, the colored merocyanine form is fixed by reacting with phenols or metallic salts.2... 

Research on liquid crystalline polymers(LCP) is a fashionable subject with the goal of developing speciality polymers of superior mechanical and thermal properties. Besides these properties, other interesting properties of LCP have not been fully utilized. We are trying to use thermotropic LCP for photon-mode image recording material. 

The simplest recording medium is a bilayer structure. It is constructed by first evaporating a highly reflective aluminum layer onto a suitable disk substrate. Next, a thin film (15-50 nm thick) of a metal, such as tellurium, is vacuum deposited on top of the aluminum layer. The laser power required to form the mark is dependent on the thermal characteristics of the metal film. Tellurium, for example, has a low thermal diffusivity and a melting point of 452 °C which make it an attractive recording material. The thermal diffusivity of the substrate material should also be as low as possible, since a significant fraction of the heat generated in the metal layer can be conducted to the substrate. For this reason, low cost polymer substrates such as poly (methylmethacrylate) or poly (vinyl chloride) are ideal. 

The great merit of thermal irreversibility is the permanent nature of the states. Therefore, fulgides have long been viewed as potential candidates for photon-mode optical recording materials. In addition, fulgides have been used as prototypes to demonstrate their potential applicability as photoswitchable functional materials. Those switch models that had appeared up until the end of 1999 are described in this chapter. 

Fulgides and related diarylethenes have been investigated extensively because of the long-term thermal stability of their photocyclized colored forms, which could lead to this application in erasable optical recording materials and photoswitchable optical elements. The entrapment of these photochromic molecules in polymer films is necessary for these practical applications. Picosecond laser photolysis was employed to study the electrocyclic reaction of a furylfulgide (18, Figure 8) in polymer solids and revealed that the colored structure was formed with a time constant of ca. lOps irrespective of the nature of the polymer matrix.49... 

Differential thermal analysis (DTA) is a thermal technique in which the temperature of a sample, compared with the temperature of a thermally inert material, is recorded as a function of the sample, inert material, or furnace temperature as the sample is heated or cooled at a uniform rate. Temperature changes in- the sample are due to endothermic or exothermic enthalpic transitions or reactions such as those caused by phase changes, fusion, crystalline structure inversions, boiling, sublimation, and vaporization, dehydration reactions, dissociation or decomposition reactions, oxidation and reduction reactions, destruction of crystalline lattice structure, and other chemical reactions. Generally speaking, phase transitions, dehydration, reduction, and some decomposition reactions produce endothermic effects, whereas crystallization, oxidation, and some decomposition reactions produce exothermic effects. 

Phthalide derivatives are of major importance in the dye industry, particularly in the area of recording material color formers. Pressure-sensitive carbonless copy paper and thermal recording paper are typical applications. Five principal structural classes have been developed extensively the xanthene dyes (fluorans (208)), 3,3-diarylphthalides (209), spirofluorenes (210), 3,3-bis(di-arylethylene)phthalides (211), and 3-substituted phthalides <84Mi 208-03>. Some of these structures are common to many familiar acid/base indicators, dyes, biological stains, or laser dyes such as fluorescein (212) and phenolphthalein (213) ,... 

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