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
  • B41M5/32—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers one component being a heavy metal compound, e.g. lead or iron

Definitions

• the invention relates to a heat-sensitive recording sheet which has a superior stability of the color image and the whiteness of the background to hair oil, grease, oil, etc.
• a heat-sensitive recording sheet using a heat color reaction between a basic colorless or lightly colored chromogenic dye and an organic color developing agent such as a phenolic substance or an organic acid is disclosed in Japanese Patent Publication Nos. 4160/1968 and 14039 / 1970, and described in Japanese Patent Laid-Open No. 27736/1973. It has many practical uses.
• a heat-sensitive recording sheet is generally prepared by applying a coating composition to the surface of the support such as paper, film, etc., which can be finely divided by individually grinding and dispersing a colorless chromogenic dye and a color developing material such as phenolic substances into fine particles dispersions obtained and by adding a binder, filler, sensitizer, lubricant and other auxiliaries.
• the oily materials are the color-forming layer consisting of a basic colorless chromogenic dye of fine particles and an organic color developing agent of fine particles, or the color-forming reaction product which is made of a basic colorless chromogenic Dye and an organic color developing agent is formed, partially dissolve or destabilize.
• the heat-sensitive recording sheets using 4-hydroxybenzoic acid ester or 4-hydroxyphthalic acid diester are generally satisfactory, but in terms of oily stability, the heat-sensitive recording sheets in which bisphenol compounds are used as color developing agents are used in previous heat-sensitive recording sheets inferior.
• the invention has for its object to provide a heat-sensitive recording sheet in which the recording image is very stable against the action of oily materials.
• R 1 is preferably a CH 3 , C 2 H 5 , C 3 H 7 , iso-C 3 H 7 , tert-C 4 H 9 9 C 5 H 11 or C 6 H 13 group; if R 29 R 3 and / or R 4 represent an alkyl group, this is preferably a methyl or ethyl group.
• halogen substituents these are preferably F, Cl and Br atoms, in particular Cl atoms.
• the amount and kind of the color developing agent to be used in the present invention are not particularly limited, but the effects of this invention are significant when monophenolic 4-hydroxyphenyl compounds and / or phthalic acid monoesters are used as the color developing agent because they are essential for improving the quality of the heat-sensitive recording sheets contribute; e.g. clear recording with high image density, no residue adhering to the thermal head, no sticking of the heat-sensitive recording sheet to the thermal head, superior recording suitability, less color formation of the background over time, etc.
• Examples of monophenolic 4-hydroxyphenyl compounds are 4-hydroxybenzoic acid esters, for example 4-hydroxybenzoic acid propyl ester, 4-hydroxybenzoic acid isopropyl ester, 4-hydroxybenzoic acid butyl ester, 4-hydroxybenzoic acid isobutyl ester, 4-hydroxybenzoic acid benzyl ester, 4-hydroxybenzyl ester; 4-hydroxyphthalic diesters, for example dimethyl 4-hydroxyphthalate, diisopropyl 4-hydroxy phthalate, dibenzyl 4-hydroxy phthalate, di-4-hydroxy phthalate, etc .; 4-hydroxyacetophenone; p-phenylphenol; Benzyl 4-hydroxyphenylacetate; p-benzylphenol; 4-hydroxyphenyl-4'-n-sulfone, 4-hydroxyphenyl-4'-n-butyloxyphenyl sulfone, 4-hydroxyphenyl-4'-n-hexyloxy-phenyl sulfone, 4-hydroxyphenyl-4'-n-
• phthalic acid monoesters are phthalic acid monophenyl ester, phthalic acid monobenzyl ester, phthalic acid monocyclohexyl ester, phthalic acid monomethylphenyl ester, phthalic acid monoethylphenyl ester, phthalic acid monoalkylbenzyl esters, phthalic acid monohalobenzyl esters, phthalic acid monoalkoxybenzyl esters and the like.
• bisphenol compounds examples include 4,4'-isopropylidene diphenol (bisphenol A), 4,4 '(1-methyl-n-hexylidene) diphenol, 4,4'-cyclohexylidene diphenol, 4,4'-thiobis-4-tert-butyl -3-methylphenol and the like. These color developing agents used in combination are unsatisfactory in stability against oily materials.
• colorless or slightly colored chromogenic dyes are useful for the invention and are not particularly limited.
• thermochromic phenomenon occurs in which the color image is extinguished immediately or slowly. Therefore, these dyes cannot be used in heat-sensitive recording sheets.
• this thermochromic phenomenon is eliminated by using the metal salts of the phthalic acid monoesters as stabilizers, which means that the above basic colorless dyes can be used.
• metal salts according to the invention of the phthalic acid monoesters of the general formula I are metal salts of phthalic acid monophenyl ester, phthalic acid monobenzyl ester, phthalic acid monocyclohexyl ester, phthalic acid monomethylphenyl ester, phthalic acid monophenyl ester, phthalic acid monoalkylbenzyl ester, phthalic acid mono ester benzyl ester, phthalic acid monoalkoxy benzyl ester, 4-methyl phthalic acid monobenzyl ester, 3-methyl phthalic acid monobenzyl ester, 5-methyl phthalic acid monobenzyl ester, 4-methyl phthalic acid monocyclohexyl ester, 5-methyl phthalic acid monobenzyl ester, and the like, methyl mono cyclohexyl ester,
• metals e.g. polyvalent metals, such as zinc, calcium, magnesium, barium and lead, preferably zinc, calcium and magnesium.
• These stabilizers can be used individually or in a mixture.
• the above-mentioned organic color developing agent, the above-mentioned organic colorless chromogenic dye and the metal salt derivative of the phthalic acid monoester are ground to a particle size of several microns or smaller by means of a grinder such as a ball mill, grinder, sand grinder, etc. or by means of a suitable emulsifying machine.
• a grinder such as a ball mill, grinder, sand grinder, etc. or by means of a suitable emulsifying machine.
• additives are added to this, depending on the intended use, in order to produce the coating color.
• the additives which can be used according to the invention are, for example, the following: binders, such as polyvinyl alcohol, are more modified Polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, starch, styrene-maleic anhydride copolymers, vinyl acetate-maleic anhydride copolymers, styrene-butadiene copolymers, etc .; inorganic or organic fillers such as kaolin, baked kaolin, diatomaceous earth, talc, titanium dioxide, calcium carbonate, magnesium carbonate, aluminum hydroxide, etc .; Release agents such as metal salts of fatty acids; Lubricants such as waxes; UV absorbers of the benzophenone and triazole series; waterproofing agents such as glyoxal, etc .; Dispersing agents, anti-foaming agents, etc.
• the amount of the metal salt derivatives of the phthalic acid monoester according to the invention and the type and the amount of the other constituents which are determined depending on the desired effect and the suitability for recording purposes are not particularly limited.
• Solution B (dispersion of a color developing agent): benzyl p-hydroxybenzoate
• the image density of the unrecorded part is left under strong conditions of 60 ° C and 45% RH for 24 hours, and then measured with a Macbeth densimeter.
• the examples according to the invention in which metal derivatives of phthalic acid monoester were used as stabilizer, gave a very good recording image even after standing for 7 days after being contaminated with castor oil, i.e. good stabilization was achieved, which is expressed in a residual image density of more than 70%.
• the stabilizers according to the invention have superior effects even when using phthalic acid monobenzyl ester as color developing agent.

Applications Claiming Priority (2)

Publications (2)

Family

ID=15554599

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (5)

Citations (1)

Family Cites Families (5)

• 1983
  • 1983-08-24 JP JP58153083A patent/JPS6046293A/ja active Granted
• 1984
  • 1984-08-21 US US06/642,788 patent/US4590500A/en not_active Expired - Lifetime
  • 1984-08-23 DE DE8484110091T patent/DE3468196D1/de not_active Expired
  • 1984-08-23 EP EP84110091A patent/EP0137982B1/fr not_active Expired

Patent Citations (1)

Also Published As

Similar Documents

Legal Events