JPS6238156B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image recording material, and more particularly to a novel recording method that uses light energy such as laser light or xenon flash light to directly produce a white or near-white record on a colored support. It's about materials.

Conventionally, various materials have been proposed as recording media using laser light, such as a recording material with a heat-softening layer containing a foaming agent on a support (Japanese Patent Publication No. 27187/1973), and white foaming using laser light. Recording Law (Special Publication No. 27187), Cloudy Recording Law (Special Publication No. 27187)
19329, Special Publication No. 43-19330), recording materials provided with metal thin films (for example, Special Publication No. 2774, Special Publication No. 1972-1974)
-7581, etc.), recording materials using chalcogen (e.g., JP-A-50-42849, JP-A-51-7928, etc.), recording materials using organic halogen compounds and leuco dyes, or organic halogen compounds and N-vinyl compounds. Recording materials (Special Publication No. 50-21807) or ink compositions that can be erased by laser light (Special Publication No. 48
-32201) and a method of decolorizing dye pigments using laser light (Japanese Patent Application Laid-open No. 79351/1983) are already known.

However, some of these do not necessarily have sufficient storage stability, and some of them develop or fade during long-term storage.

For example, the storage conditions for thermal recording paper are usually below 60°C.
Humidity is 80% RH or less, and the same applies to storage after recording. If the thermal recording paper after recording is stored at a temperature of 60°C or higher and humidity of 80% RH or higher, or if it comes into contact with organic solvents, areas other than the image will develop color, making the recorded image illegible.

The present invention is a novel recording material in which a layer consisting of a binder and a substance that is photothermally decomposed by light energy such as laser light or xenon flash light to produce a white or nearly white compound is provided on a colored support. Compared to conventional products, it has better storage stability with respect to temperature, humidity, organic solvents, etc., both in unrecorded and recorded states.

Further, the present invention is well suited to devices using energy sources such as laser light or xenon flash light that apply high energy in a short period of time and convert into heat, and can produce clear and sharp recorded images.

Specific examples of compounds that give a white or nearly white color with light energy used in the present invention include (1) metal salts of nitric acid, zinc nitrate, aluminum nitrate, cerous nitrate, ceric/ammonium nitrate, and nitric acid; 1 Cerium/ammonium, bismuth nitrate, barium nitrate, calcium nitrate, magnesium nitrate (2) Metal salts of organic carboxylic acids Zinc formate, calcium formate, magnesium formate, barium formate, cadmium formate, aluminum formate, zinc acetate, calcium acetate, acetic acid Barium, stannous acetate, bismuth acetate, cadmium acetate, zinc oxalate, calcium oxalate, barium oxalate, stannous oxalate, aluminum oxalate, titanyl oxalate, zirconium oxalate, aluminum ammonium oxalate,
Aluminum/potassium oxalate, zinc/potassium oxalate, antimony/potassium oxalate, titanium/ammonium oxalate, barium hydrogen oxalate, barium succinate, calcium succinate, magnesium succinate, barium oxal-succinate, citric acid Zinc, calcium citrate, bismuth citrate, barium citrate, magnesium citrate, aluminum citrate, bismuth ammonium citrate, zinc salicylate, barium salicylate, cadmium salicylate, bismuth salicylate, zinc tartrate, stannous tartrate, bismuth tartrate , antimony tartrate, antimonyl potassium tartrate, zinc propionate, magnesium propionate, calcium propionate, zinc benzoate, magnesium benzoate, bismuth benzoate, zinc maleate, calcium maleate, zinc lactate, barium lactate, calcium malonate , barium palmitate, zinc acrylate, zinc methacrylate, calcium methacrylate, zinc lactate, barium lactate, calcium malate, etc., but are not limited to these.

The above metal salt of nitric acid becomes a corresponding white or nearly white metal oxide when exposed to laser light or xenon flash light. Metal salts of organic carboxylic acids become white or nearly white carbonates or metal oxides depending on the energy content.

The binder that can be used in the present invention may be either water-soluble or organic solvent-soluble, such as polyvinyl alcohol, gelatin, casein, starch, starch derivatives, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, gum arabic, polyvinylpyrrolidone,
Water-soluble binders such as polyvinyl acetate, polyvinyl chloride, polyacrylic ester, styrene-butadiene copolymer, styrene-acrylic ester copolymer, vinyl acetate-ethylene copolymer, etc. emulsion, natural rubber latex or resins soluble in organic solvents such as polyvinyl acetate, polyvinyl chloride, polystyrene, polyvinyl butyral, epoxy resins, alkyd resins, terpene resins, ketone resins, urethane resins, ethyl cellulose, cellulose acetate, nitrocellulose, etc. A blade on the surface of a support colored with a paint consisting of one or more binders and one or more of the metal salts of nitric acid and metal salts of organic carboxylic acids,
Apply with various coating machines such as applicators and wire bars.

As the colored support, carbon black, paper coated or impregnated with dyes or colored pigments, colored heat-resistant plastic film, etc. can be used.

Next, the present invention will be explained with reference to comparative examples and examples.

Comparative example 1 10g of carbon black, polyvinyl alcohol
100 g of a 20% aqueous solution, 0.1 g of funnel oil as a dispersant, and 50 g of water were placed in a ball mill and dispersed for 5 hours. To 150 g of this dispersion, 10 g of a 20% glyoxal aqueous solution was added and thoroughly mixed, and the paint was applied to 60 g/m ² of high-quality paper at a dry coating weight of 4 g/m ² .

A pattern cut out from aluminum foil in the form of a figure is superimposed on this recording paper, and xenon flash light (resource xenofax FX-) is applied from the pattern side.
150), a slightly graphical record was obtained, but the contrast density was low. This recording paper was measured with a Macbeth densitometer and had a density of 2.02 before recording and a density of 1.63 after recording, with a contrast density difference of 0.39.

Example 1 When 10 g of titanium/potassium oxalate was added to 50 g of a 20% polyvinyl alcohol aqueous solution and stirred, the titanium/potassium oxalate was completely dissolved to become a transparent solution. This solution was applied onto the black recording paper used as Comparative Example 1 so that the dry coating amount was 3 g/m ² . When this recording paper was used for recording in the same manner as in Comparative Example 1, a clear white image with high contrast was obtained. The density of this recording paper before recording is
2.04, the density after recording is 0.61 and the contrast density is
It was 1.43. Furthermore, when the recorded sample of this example and the thermal recording using leuco dye were left in an oven at 100°C for 3 hours, the entire surface of the thermal recording paper developed color, but the sample of this example showed no change at all. Ta.

Example 2 A paint obtained by dissolving 10 g of zinc nitrate in 10 g of water and adding 50 g of 20% polyvinyl alcohol and thoroughly mixing the mixture was applied onto the recording paper of Comparative Example 1 so that the dry coating amount was 5 g/ ^m2 . . When this recording paper was recorded in the same manner as in Comparative Example 1, an image with high contrast was obtained.

The density of this recording paper before recording was 2.10, the density after recording was 0.73, and the contrast density was 1.37.

As described above, the present invention utilizes laser light, xenon
This relates to a new photothermal recording material that can produce a clear white image with high contrast on a colored support using light energy such as flash light, and has better storage stability than conventional materials. There is no need to pay close attention to this, and it is easy to handle.

Claims (1)

[Claims] 1. A layer consisting of a binder and one or more of metal salts of nitric acid and metal salts of organic carboxylic acid, which produce a white or nearly white compound when photothermally decomposed, is provided on the colored light absorption heat conversion layer. A photothermal recording material characterized by: