Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
  • B41M5/333—Colour developing components therefor, e.g. acidic compounds
  • B41M5/3333—Non-macromolecular compounds
  • B41M5/3335—Compounds containing phenolic or carboxylic acid groups or metal salts thereof
  • B41M5/3336—Sulfur compounds, e.g. sulfones, sulfides, sulfonamides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
  • B41M5/337—Additives; Binders
  • B41M5/3375—Non-macromolecular compounds

Definitions

• the present invention relates to a heat-sensitive recording sheet which is superior in writability when using an oily ink.
• a heat-sensitive recording sheet is generally prepared by applying to the surface of a support such as paper, synthetic paper, film, plastic, etc., a coating composition which is obtained by finely grinding and dispersing a colorless chromogenic substance and a color developing agent, mixing the dispersions obtained and adding one Binder, filler, sensitizer, lubricant and other auxiliaries. Under the influence of heat from the thermal spring, thermal head, thermal stamp, laser beam, etc., an instantaneous chemical conversion takes place, which leads to the recording.
• heat-sensitive recording sheets include their use in technical recording devices, computer terminal printers, printers for facsimile machines, automatic ticket machines, printers for bar code papers, etc. Recently, much higher and more varied requirements have been placed on recording devices, which is why a high quality of the Record sheet required. For example, in the case of rapid recording heat sensitive recording sheet have a clear high density recording image even with little heat input, and it is said to have further superior resistance to the effects of light, climate and oils.
• the heat sensitive recording sheets have been widely used, so that the description is often made with oily ink.
• the color of the ink on the heat-sensitive recording sheet has changed because the color of the ink mixes with the color developed by the heat-sensitive recording sheet.
• the red of an oily ink used to write a heat-sensitive recording sheet forming a black color mixes with the black of the recording sheet so that the pure red color is not found.
• the present invention is therefore based on the object of providing a heat-sensitive recording sheet with improved writability.
• the color formation layer 4-hydroxy-4'-n-propoxydiphenylsulfone as an organic color developing agent and at least one sensitizer from the group 1,2-di (3-methylphenoxy) ethane, di (p-methylbenzyl) oxalate, p- Contains benzylbiphenyl, ⁇ -benzyloxynaphthalene and 4-biphenyl-p-tolyl ether.
• the basic colorless or slightly colored chromogenic dyes which are suitable according to the invention are dyes of the triphenylmethane, fluorane, azaphthalide and fluorene series, for example of the following type: Triphenylmethane series leuco dye 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide (crystal violet lactone) Fluorine series leuco dye 3-diethylamino-6-methyl-7-anilinofluoran, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluoran, 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7- (o, p-dimethylanilino) fluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran,
• Azoaphthalide series leuco dye 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2- methylindol-3-yl) -7-azaphthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-octyl-2-methylindol-3-yl) -4-azaphthalide, 3- (4-Cyclohexyl-N-methylamino-2-methoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide.
• Fluorene series leuco dye 3,6,6′-tris (dimethylamino) spiro [fluorene-9,3′-phthalide] 3,6,6′-tris (diathylamino) spiro [fluorene-9,3′-phthalide].
• At least one sensitizer from the group consisting of 1,2-di (3-methylphenoxy) ether, di (p-methylbenzyl) oxalate, p-benzylbiphenyl, ⁇ -benzyloxynaphthalene and 4-biphenyl-p-tolyl ether are used according to the invention used.
• This sensitizer is effective for the purpose of the invention.
• the following stabilizers can also be added to the color development layer according to the invention: 4,4'-butylidene (6-t-butyl-3-methylphenol), 2,2'-di-t-butyl-5,5-dimethyl-4,4 ' sulfonyldiphenol, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 1,1,3- Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane and so on.
• applicable binder include completely saponified polyvinyl alcohol (polymerization degree: 200-1900), partially saponified (polyvinyl alcohol, carboxylated polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-polyvinyl alcohol, butyralmod er polyvinyl alcohol, other modified polyvinyl alcohols, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, styrene-maleic anhydride copolymers, styrene -Butadiene copolymers, cellulose derivatives such as ethyl cellulose and acetyl cellulose, polyvinyl chloride, polyvinyl acetate, polyacrylamide, polyacrylic acid esters, polyvinyl butyral, polystyrene, copolymers of the above compounds, polyamide resins, silicone resins, petroleum synthetic resins, terpene resins, ketone resins and co-molecular resins dissolved
• binders can be used in combination depending on the purpose.
• Both inorganic and organic fillers can be used as fillers according to the invention.
• Typical examples of the fillers according to the invention are silicon dioxide, calcium carbonate, kaolin, baked kaolin, diatomaceous earth, talc, titanium oxide and aluminum hydroxide.
• Release agents such as metal salts of fatty acids, lubricants such as waxes, UV absorbers of the benzophenone and triazone series, water-proofing agents such as glyoxal etc., dispersants, anti-foaming agents and the like can also be used.
• the type and the amount of the organic color developing agent according to the invention, the basic colorless dye according to the invention and the other constituents, which are determined depending on the desired effect and suitability for recording purposes, are not particularly limited. It is generally advantageous to add 1-8 parts by weight of the organic color developing agent according to the invention and 1-20 parts by weight of filler, based on 1 part by weight of the basic colorless dye according to the invention use, and 10-25 parts by weight of binder, based on the total content.
• the heat-sensitive recording sheet of the present invention is produced by applying a coating composition of the above composition on a support such as paper, synthetic paper, film, plastic, etc.
• a top layer e.g. from a polymer, are applied to the color development layer.
• the above organic color developing agent according to the invention, the colorless basic chromogenic dye and optionally the other additives are ground to a particle size of several microns or smaller by means of a grinding device such as a ball mill, attritor, sand grinder etc. or by means of a suitable emulsifying device.
• a grinding device such as a ball mill, attritor, sand grinder etc. or by means of a suitable emulsifying device.
• Various additives are added to produce the coating composition of the invention.
• a rear coating layer for example made of a polymer containing the filler, can be applied further under the color development layer
• the color developing agent, the leuco dye and the sensitizer of the heat-sensitive color-developing layer are dissolved in the organic solvent contained in the ink. After volatilization of the solvent, a color developing composition consisting of the color developing agent, the leuco dye and the sensitizer is formed at the description point. For example, when using a red ink, the red color and the color developed by the composition mentioned are mixed, thereby forming a dark descriptive color.
• the heat-sensitive recording sheet of the present invention comprises 4-hydroxy-4'-n-propoxydiphenylsulfone as a special color developing agent, a leuco dye and a special sensitizer. These materials have very low solubility in the solvent and they form practically no color developing composition upon volatilization of the solvent, so that there is no color change when using an oily ink.
• the color developing agents and the dye used according to the invention have a higher solution diffusion rate and very high solubility in the sensitizer.
• the sensitizer and the leuco dye undergo a physico-chemical reaction in the heat, a color developing composition is rapidly formed, so that a colored image having a high density is obtained.
• the sensitizer according to the invention has the property that when it is dissolved in the organic solvent contained in the oily ink and after the solvent has volatilized, it crystallizes only with difficulty. Therefore, white crystals are not formed in the description with the oily ink.
• Parts by weight means “parts”.
• Solution A color developer dispersion
• 4-hydroxy-4'-n-propoxyphenylsulfone 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts water 11.2 parts
• Solution B die dispersion
• 3-N-n-dibutylamino-6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts water 2.6 parts
• Solution C sensitizer dispersion
• Table 1 sensitizer 4.0 parts 10% aqueous solution of polyvinyl alcohol 5.0 parts water 3.0 parts
• This coating composition was applied in a coating amount of 6.0 g / m2 on a base paper with a weight of 50 g / m2, dried and supercalendered to achieve a smoothness of 200-600 seconds.
• a black color developing heat sensitive recording sheet was obtained.
• Solution E color developer dispersion
• Color developing agents in Table 1 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts water 11.2 parts
• Solution B die dispersion
• 3-N-n-dibutylamino-6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts water 2.6 parts
• a heat-sensitive recording sheet was obtained in the same manner as in Example 1.
• Solution A color developer dispersion
• 4-hydroxy-4'-n-propoxyphenylsulfone 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts water 11.2 parts
• Solution B die dispersion
• 3-N-n-dibutylamino-6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts water 2.6 parts
• Solution F sensitizer dispersion
• Table 1 sensitizer 4.0 parts 10% aqueous polyvinyl alcohol solution 5.0 parts water 3.0 parts

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Heat Sensitive Colour Forming Recording (AREA)

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Publications (3)

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Citations (6)

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• 1989
  • 1989-10-13 JP JP1267590A patent/JPH0745266B2/ja not_active Expired - Lifetime
• 1990
  • 1990-10-01 US US07/590,807 patent/US5118656A/en not_active Expired - Lifetime
  • 1990-10-11 CA CA002027362A patent/CA2027362C/fr not_active Expired - Lifetime
  • 1990-10-12 DE DE59005918T patent/DE59005918D1/de not_active Expired - Lifetime
  • 1990-10-12 EP EP90119625A patent/EP0422680B1/fr not_active Expired - Lifetime

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