WO2000026037A1 - Heat sensitive recording material - Google Patents

Heat sensitive recording material Download PDF

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Publication number
WO2000026037A1
WO2000026037A1 PCT/EP1999/007895 EP9907895W WO0026037A1 WO 2000026037 A1 WO2000026037 A1 WO 2000026037A1 EP 9907895 W EP9907895 W EP 9907895W WO 0026037 A1 WO0026037 A1 WO 0026037A1
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WO
WIPO (PCT)
Prior art keywords
methyl
anilinofluoran
bis
hydroxy
heat sensitive
Prior art date
Application number
PCT/EP1999/007895
Other languages
French (fr)
Inventor
Michael Heneghan
Roy Alan Kirk
James Philip Taylor
Original Assignee
Ciba Specialty Chemicals Holding Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9823753.0A external-priority patent/GB9823753D0/en
Priority claimed from GBGB9827566.2A external-priority patent/GB9827566D0/en
Application filed by Ciba Specialty Chemicals Holding Inc. filed Critical Ciba Specialty Chemicals Holding Inc.
Priority to AU64737/99A priority Critical patent/AU6473799A/en
Publication of WO2000026037A1 publication Critical patent/WO2000026037A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B67/00—Influencing the physical, e.g. the dyeing or printing properties of dyestuffs without chemical reactions, e.g. by treating with solvents grinding or grinding assistants, coating of pigments or dyes; Process features in the making of dyestuff preparations; Dyestuff preparations of a special physical nature, e.g. tablets, films
    • C09B67/0033—Blends of pigments; Mixtured crystals; Solid solutions
    • 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
    • B41M5/323—Organic colour formers, e.g. leuco dyes
    • 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
    • B41M5/323—Organic colour formers, e.g. leuco dyes
    • B41M5/327—Organic colour formers, e.g. leuco dyes with a lactone or lactam ring
    • B41M5/3275—Fluoran compounds
    • 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
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D493/00—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system
    • C07D493/02—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system in which the condensed system contains two hetero rings
    • C07D493/10—Spiro-condensed systems

Definitions

  • the present invention relates to heat sensitive recording materials. It more particularly relates to such recording material in the form of sheets coated with colour-forming systems comprising a colourless or pale coloured electron donative compound (colour forming compound) and an organic electron acceptor (developer).
  • colour-forming systems comprising a colourless or pale coloured electron donative compound (colour forming compound) and an organic electron acceptor (developer).
  • Heat sensitive recording has conventionally been used as a system for recording transferred information through the mediation of heat, by utilising a colour reaction between a colour forming compound and a developer.
  • the properties which are most desirable in a colour forming material, in addition to the effective development of colour, are thermal response, background whiteness and image stability, especially light fastness of the developed colour, heat fastness of the developed colour and water fastness of the developed colour.
  • the present invention is directed to heat sensitive recording material, comprising a) at least one colour forming compound selected from the group consisting of 3-diethylamino-6-methyl-7-(3-methylanilino) fluoran, 3-dibutylamino-6-methyl-7- anilinofluoran, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-propylamino)-6- methyl-7-anilinofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran and 3-(N-ethyl- N-isoamylamino)-6-methyl-7-anilinofluoran; or a monophase solid solution comprising at least two colour forming compounds; b) at least one sensitiser of the formula wherein R and R' are identical or different from each other and each represent C ⁇ -C 6 alkyl; and c) at least one developer.
  • R and R' are methyl, ethyl, n- or iso-propyl and n-, sec- or tert-butyl.
  • the substituents R and R' are identical or different from each other and each are preferably C C alkyl, especially methyl or ethyl, in particular ethyl.
  • Preferred sensitisers are those of the formula
  • sensitisers of the formula (3) are sensitisers of the formula (3).
  • the sensitisers of the formula (1) can also be used in admixture with other known sensitisers or other sensitisers of the above formula (1).
  • Preferred mixtures are those which contain more than one sensitiser of the above formula (1), especially a sensitiser of the formula (3) and a sensitiser of the formula (4).
  • mixtures of sensitisers contain preferably at least 40% by weight, especially 50% by weight, of sensitisers of the above formula (1). Highly preferred are mixtures which contain at least 60% by weight, especially 80% by weight, of sensitisers of the above formula (1).
  • Highly preferred as colour forming compound is 3-dibutylamino-6-methyl-7-anilinofluoran, especially in combination with a sensitiser of the formula (3).
  • colour forming compounds can be used singly or as a mixture with other colour forming compounds such as triphenylmethanes, lactones, fluorans, benzoxazines and spiropyrans in order to adjust the developed hue if desired; or they may also be used together with further black colour forming compounds.
  • other colour forming compounds such as triphenylmethanes, lactones, fluorans, benzoxazines and spiropyrans in order to adjust the developed hue if desired; or they may also be used together with further black colour forming compounds.
  • colour forming compounds which may be used as above, include but are not limited to; 3-diethylamino-6-methylfluoran, 3-dimethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3- diethylamino-6-methyl-7-(2,4-dimethylanilino) fluoran, 3-diethylamino-6-methyl-7- chlorofluoran, 3-diethylamino-6-methyl-7-(3-trifluoromethylanilino) fluoran, 3-diethylamino-6- methyl-7-(2-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-chloroanilino) fluoran, 3- diethylamino-6-methyl-7-(2-fluoroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-n-octylanilino) flu
  • Examples of such mixtures are a mixture of 3-diethylamino-6-methyl-7-anilino fluoran and 3- dibutylamino-6-methyl-7-anilinofluoran, a mixture of 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran and 3-dibutylamino-6- methyl-7-anilinofluoran, and a mixture of 3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofluoran and 3-dibutylamino-6- methyl-7-anilinofluoran.
  • mixtures of colour forming compounds contain preferably at least 40% by weight, especially at least 60% by weight, of the colour forming compounds given at the beginning under a) (3-diethylamino-6-methyl-7-(3-methylanilino) fluoran, 3-dibutylamino- 6-methyl-7-anilinofluoran, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-(N-methyl-N- propylamino)-6-methyl-7-aniIinofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran).
  • Highly preferred are mixtures which contain at least 80% by weight, especially at least 90% by weight, of the colour forming compounds given at the beginning.
  • a monophase (or single-phase or guest-host) solid solution possesses a crystal lattice which is identical with the crystal lattice of one of its components.
  • One component is embedded as the 'guest' in the crystal lattice of the other component, which acts as the 'host'.
  • the X-ray diffraction pattern of such a monophase solid solution is substantially identical to that of one of the components, called the 'host'. Within certain limits, different proportions of the components produce almost identical results.
  • a monophase (or single-phase or guest-host) solid solution possesses a crystal lattice which is identical with the crystal lattice of one of its components.
  • One component is embedded as the 'guest' in the crystal lattice of the other component, which acts as the 'host'.
  • the X-ray diffraction pattern of such a monophase solid solution is substantially identical to that of one of the components, called the 'host'. Within certain limits, different proportions of the components produce almost identical results.
  • a multiphase solid solution possesses no precise, uniform crystal lattice. It differs from a physical mixture of its components in that the crystal lattice of at least one of its components is partially or competely altered. In comparison to a physical mixture of the components, which gives an X-ray diffraction diagram that is additive of the diagrams seen for the individual components.
  • the signals in the X-ray diffraction diagram of a multiphase solid solution are broadened, shifted or altered in intensity. In general, different proportions of the components produce different results.
  • a mixed crystal (or solid compound type) solid solution possesses a precise composition and a uniform crystal lattice, which is different from the crystal lattices of all its components. If different proportions of the components lead, within certain limits, to the same result, then a solid solution is present in which the mixed crystal acts as a host.
  • amorphous structures and mixed aggregates consisting of different particles of different physical type, such as, for example, an aggregate of different components each in pure crystal modification.
  • Such amorphous structures and mixed aggregates cannot be equated with either solid solutions or mixed crystals, and possess different fundamental properties.
  • the monophase solid solutions comprise a plurality of colour compounds.
  • Suitable colour forming materials which may be included in the solid solutions according to the present invention, include but are not limited to; 3-diethylamino-6- methylfluoran, 3-dimethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7- anilinofluoran, 3-diethylamino-6-methyl-7-(2,4-dimethylanilino) fluoran, 3-diethylamino-6- methyl-7-chlorofluoran, 3-diethylamino-6-methyl-7-(3-trifluoromethylanilino) fluoran, 3- diethylamino-6-methyl-7-(2-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-(2-fluoroanilino) fluoran,
  • Preferred herein are monophase solid solutions containing, as one of the components, a fluoran compound such as 3-diethylamino-6-methylfluoran, 3-dimethylamino-6-methyl-7- anilinofluoran, 3-diethylamino-6-methyI-7-anilinofIuoran, 3-diethylamino-6-methyl-7-(2,4- dimethylanilino) fluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-6-methyl-7- (3-trifluoromethylanilino) fluoran, 3-diethylamino-6-methyl-7-(2-chloroanilino) fluoran, 3- diethylamino-6-methyl-7-(4-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-(2-fluoroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-chlor
  • Highly preferred monophase solid solutions are composed of at least two fluoran compounds of the general formula (5)
  • Ri and R 2 independently represent hydrogen; a straight or branched chain alkyl of 1-18 carbon, a secondary alkyl with respect to the carbon atom bonded to the nitrogen atom of 3-13 carbon atoms; a cycloalkyl of 4-8 carbon atoms or a phenyl, both of which may be substituted by at least one substituent selected from the group consisting of halogen atoms and alkyls having 1-4 carbon atoms, an aralkyl of 7-10 carbon atoms.
  • Ri and R 2 together with the adjacent nitrogen atom may form a heterocyclic ring.
  • R 3 is hydrogen; an alkyl of 1-4 carbon atoms; an alkoxy of 1-4 carbon atoms; a phenyl; a substituted phenyl or a halogen.
  • R 4 is an alkyl group of 1-18 carbon atoms; a carboxyalkyl of 1-18 carbon atoms; a carboxycycloalkyl of 4-8 carbon atoms; an alkylamino of 1-18 carbon atoms; a cycloalkylamino of 4-8 carbon atoms; a dialkylamino or dicycloalkylamino as previously defined; an arylamino; a substituted arylamino; an aralkylamino of 7-10 carbon atoms; a diaralkylamino as previously defined.
  • R 5 is an alkyl of 1-18 carbon atoms; a carboxy alkyl of 1-18 carbon atoms or a halogen.
  • the ratio of the components being in the range 0.1-99.9% by mole, especially 0.1-30%.
  • the first compound is in a molar ratio of 75 to 99.9% by mole
  • the second compound is in a ratio of 25 to 0.1% by mole.
  • Examples of monophase solid solutions comprising two components A and B in the stated ratios are: 3-dibutylamino-6-methyl-7-anilinofluoran (99.9%), 3-diethylamino-6-methyl-7- anilinofluoran (0.1%);
  • 3-diethylamino-6-methyl-7-anilinofluoran (90%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (10%); 3-diethylamino-6-methyl-7-anilinofluoran (80%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (20%);
  • 3-dibutylamino-6-methyl-7-anilinofluoran (90%), mixture of 2-phenyl-4-(4- diethylaminophenyl)-4-(4-methoxyphenyl)-6-methyl-7-dimethylamino-3,1 -benzoxazine and 2- phenyl-4-(4-diethylaminophenyl)-4-(4-methoxyphenyl)-8-methyl-7-dimethylamino-3,1- benzoxazine(10%);
  • 3-dibutylamino-6-methyl-7-anilinofluoran (80%), mixture of 2-phenyl-4-(4- diethylaminophenyl)-4-(4-methoxyphenyl)-6-methyl-7-dimethylamino-3,1 -benzoxazine and 2- phenyl-4-(4-diethylaminophenyl)-4-(4-methoxyphenyl)-8-methyl-7-dimethylamino-3,1- benzoxazine(20%);
  • the monophase solid solutions can be used singly or as a mixture with other colour forming compounds such as triphenylmethanes, lactones, fluorans, benzoxazines and spiropyrans in order to adjust the developed hue if desired; or they may also be used together with further black colour forming compounds. Examples of such other colour forming compounds are given hereinbefore.
  • the monophase solid solutions can be prepared by a variety of methods.
  • One such method is the recrystallisation method wherein a physical mixture of the desired components is dissolved, with or without heating, in a suitable solvent or solvent mixture.
  • suitable solvents include but are not limited to toluene, benzene, xylene, dichlorobenzene, chlorobenzene, 1 ,2-dichloroethane, methanol, ethanol, iso-propanol, n-butanol, acetonitrile, dimethylformamide or mixtures of these solvents with each other and with water.
  • the monophase solid solution is then isolated by crystallisation from the solvent or solvent mixture.
  • monophase solid solutions can be prepared from mixtures of the appropriate starting materials.
  • the technique can be used to produce mixtures of two or more fluorans or phthalides.
  • mixtures of two fluorans are produced by replacing a single starting material with two analogous materials to the same total molar concentration in the reaction.
  • these starting materials are derivatives of amino phenols, phthalic anhydrides, keto acids and diphenylamines.
  • the first method of preparation uses the reaction of an appropriate mixture of keto acids of formula (6) and compounds of formula (7) to give the desired monophase solid solution.
  • R r R 5 have the meanings given previously and R 6 is hydrogen or alkyl of 1-4 carbon atoms.
  • a two component monophase solution consisting of two compounds of general formula (5) may be prepared by reaction of;
  • the monophase solid solutions can be prepared by reaction between keto acid(s) of formula (6) and compound(s) of formula (7) in the presence of a dehydrating condensation agent, for example, concentrated sulphuric acid, oleum - concentrated sulphuric acid mixtures, polyphosphoric acid, phosphorous pentaoxide or anhydrous aluminium chloride, and mixtures thereof, preferably concentrated sulphuric acid or oleum-concentrated sulphuric acid mixtures, and thereafter bringing the reaction mixture to an alkaline pH in the presence or absence of organic solvent.
  • a dehydrating condensation agent for example, concentrated sulphuric acid, oleum - concentrated sulphuric acid mixtures, polyphosphoric acid, phosphorous pentaoxide or anhydrous aluminium chloride, and mixtures thereof, preferably concentrated sulphuric acid or oleum-concentrated sulphuric acid mixtures, and thereafter bringing the reaction mixture to an alkaline pH in the presence or absence of organic solvent.
  • the solvent may be exemplified by aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzenes, trichlorobenzenes or bromonapthalenes, halogenated aliphatic hydrocarbons such as dichloroethane, trichloroethane or tetrachloroethane, aliphatic hydrocarbons such as hexane, heptane, octane or n-decane and alicyclic hydrocarbons such as cyclohexane or methylcyclohexane.
  • aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes
  • halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzenes, trichlorobenzenes or bromon
  • alcohols such as amyl alcohol, 2-ethylhexanol or octyl alcohol, ethers such as isopropyl ether, or ketones such as cyclohexanone.
  • the solvent may be used singly or as a mixture.
  • the condensation reaction is generally carried out at from 0 to about 100°C preferably from about 10 to about 60°C for several to 100 hours.
  • the reaction temperature is preferably in the range from 0 to about 50°C.
  • the reaction time depends upon the selected reaction temperature and hence the reaction is conducted for a sufficient time to permit the reaction to go to completion. Completion of reaction is determined using standard analytical techniques, including but not limited to, thin layer chromatography, gas chromatography and liquid chromatography.
  • the alkali treatment may be carried out by addition of the reaction mass to a stirred mixture of base, water and organic solvent.
  • Suitable bases include, for example, potassium hydroxide, lithium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, lithium carbonate, ammonia or organic bases such as triethylamine and mixtures thereof.
  • the preferred bases for use in the process are sodium hydroxide and potassium hydroxide.
  • Suitable solvents include toluene, xylene, halogenated aromatic solvents such as chlorobenzene, esters, ketones, alcohols such as 2-ethylhexanol and mixtures thereof. Additional base may be added as required to achieve an alkalinity within the pH range of 9-12.
  • the treatment may be conducted in a temperature of from 0°C to the boiling point of the solvent or solvent mixture in use, preferably 50 -100°C.
  • the monophase solid solution according to the present invention may be precipitated from the reaction media.
  • the crystalline precipitate may then be isolated by filtration from the reaction liquors.
  • the monophase solid solution may be washed as desired with water and/or an organic solvent.
  • the solvent may be exemplified by aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzenes, trichlorobenzenes or bromonapthalenes, halogenated aliphatic hydrocarbons such as dichloroethane, trichloroethane or tetrachloroethane, aliphatic hydrocarbons such as hexane, heptane, octane or n-decane and alicyclic hydrocarbons such as cyclohexane or methylcyclohexane.
  • aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes
  • halogenated aromatic hydrocarbons such as chlorobenz
  • alcohols such as methanol, ethanol, isopropanol, butanol, amyl alcohol, 2- ethylhexanol or octyl alcohol, ethers such as isopropyl ether, or ketones such as cyclohexanone.
  • the solvent may be used singly or as a mixture.
  • reaction mass may be quenched into a stirred water-solvent mixture at from 0 to about 100°C, preferably 60-90°C.
  • the solvent used is not specifically limited provided that it is insoluble or only slightly soluble in water.
  • the solvent may be exemplified by aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzenes, trichlorobenzenes or bromonapthalenes, halogenated aliphatic hydrocarbons such as dichloroethane, trichloroethane or tetrachloroethane, aliphatic hydrocarbons such as hexane, heptane, octane or n-decane and alicyclic hydrocarbons such as cyclohexane or methylcyclohexane.
  • aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes
  • halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzenes, trichlorobenzenes or bromon
  • alcohols such as amyl alcohol, 2-ethylhexanol or octyl alcohol, ethers such as isopropyl ether, or ketones such as cyclohexanone.
  • the solvent may be used singly or as a mixture.
  • Sufficient base for example potassium hydroxide, lithium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, lithium carbonate, ammonia or organic bases such as triethylamine and mixtures thereof, is then added to provide an organic-aqueous phase separation. The aqueous layer may then be separated if desired.
  • reaction mass is stirred at from 0 to about 100°C, preferably 60-90°C, in order to complete cyclisation to the fluoran product.
  • the reaction mass is then adjusted to 25°C and the precipitated crystalline product may then be isolated by filtration as discussed hereinbefore.
  • the reaction product is isolated by filtration from the reaction liquors as the crystal of the invention. After isolation, the crystal may be washed with water and/or an organic solvent as defined previously. In this manner is isolated the monophase solid solution.
  • This recrystallised crystalline product may then be dried by a usual method, such as at a raised temperature, below the melting point of the crystal, under vacuum, to obtain the monophase solid solutions.
  • the composition of the monophase solid solution obtained is dependant upon the relative amounts of starting materials used.
  • a third method of preparation is to prepare a mixed keto acid intermediate of general formula (6) from the reaction of aminophenols of general formula (8) with phthalic anhydrides of general formula (9).
  • R,, R 2 and R 5 are as hereinbefore detailed.
  • a mixed keto acid intermediate consisting of two compounds of general formula (6) may be prepared by reaction of:
  • Amino phenols of formula (8) are exemplified by, but not limited to: N,N-dimethyl aminophenol, N,N-diethyl aminophenol, N,N-di-n-propyl aminophenol, N,N-di- n-butyl aminophenol, N,N-di-n-pentyl aminophenol, N,N-di-n-hexyl aminophenol, N,N- diisopropyl aminophenol, N,N-disecbutyl aminophenol, N,N-diisobutyl aminophenol, N,N- diisoamyl aminophenol, N-methyl-N-cyclohexyl aminophenol, N-methyl-N-phenyl aminophenol, N-methyl-N-(2-methylphenyl) aminophenol, N-methyl-N-(3-methylphenyl) aminophenol, N-methyl-N-(4-methylphenyl) aminophenol, N-methyl-N-propyl aminophenol, N-methyl-N
  • phthalic anhydride terephthalic anhydride, 3-methylphthalic anhydride, 3-nitrophthalic anhydride, 3- hydroxyphthalic anhydride, 3-chlorophthalic anhydride, 3-fluorophthalic anhydride, 4- methylphthalic anhydride, 4-t-butylphthalic anhydride, 4-chlorophthalic anhydride, 4- bromophthalic anhydride, 4-fluorophthalic anhydride, 3,6-dichlorophthalic anhydride, 3,6- dimethylphthalic anhydride, 3,6-difluorophthalic anhydride, 4,5-difluorophthalic anhydride, 4,5-dichlorophthalic anhydride, 1 ,2-napthoic anhydride, 2,3-napthoic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, tetraiod
  • the latter is usually used in an amount of 0.5-2.0 moles per total moles of the m-aminophenol derivatives.
  • the ratio of solvent to m-aminophenol derivatives may be between 0 and 20 parts by weight.
  • the quantity of solvent chosen is dependant on the nature of the m-aminophenol derivatives.
  • the amount of solvent used is determined so that the reaction mass remains mobile throughout the course of the reaction.
  • the product is precipitated during the reaction.
  • the reaction is effected at an elevated temperature, preferably in the range of 60-120°C for a period of 3-40 hours.
  • reaction time, solvent ratio and temperature are chosen so as to achieve a suitable balance between length of reaction and the amount of rhodamine type side products that are produced.
  • the amount of rhodamine produced increases at higher temperatures.
  • the reaction mixture is cooled to 0-60°C, most preferably 20-40°C. Dependant on the viscosity of the reaction mixture at this stage, a secondary solvent may be added to the reaction mixture to maintain mobility.
  • an aromatic hydrocarbon of 6-10 carbon atoms such as benzene, toluene or xylene
  • an aliphatic hydrocarbons of 5-12 carbons such as pentane, octane, isooctane, or decane
  • a halogenated aliphatic, cycloaliphatic or aromatic hydrocarbon of 2-8 carbons such as perclene, chlorobenzene or dichlorobenzene
  • ethers such as tetrahydrofuran, dibutyl ether or diphenylether
  • alcohols such as methanol, ethanol, propanols such as isopropanols or butanols such as n-butanol.
  • the crude keto acid derivative may be recovered from the reaction mixture by filtration, or by diluting the mixture with a solvent in which the derivative is barely soluble and recovering the precipitated derivative by filtration, or by extracting the derivative with an aqueous alkaline solution and precipitating it with acid, or by forming the sodium salt of the derivative, isolating the salt and precipitating it with acid.
  • the organic solvents when used include, for example, an aromatic hydrocarbon of 6-10 carbon atoms such as benzene, toluene or xylene, an aliphatic hydrocarbon of 8-12 carbons such as octane, isooctane, or decane, a halogenated hydrocarbon of 2-8 carbons, aliphatic, cycloaliphatic or aromatic, such as perclene, chlorobenzene or dichlorobenzene, ethers such as tetrahydrofuran, dibutyl ether or diphenylether, among which are especially preferred aromatic hydrocarbons or ethers.
  • an aromatic hydrocarbon of 6-10 carbon atoms such as benzene, toluene or xylene
  • an aliphatic hydrocarbon of 8-12 carbons such as octane, isooctane, or decane
  • a halogenated hydrocarbon of 2-8 carbons aliphatic, cycloaliphatic or
  • the mixture of keto acids of general formula (6) thus isolated can then be reacted with a diphenylamine of general formula (7), as described previously, to produce a monophase solid solution of formula (5).
  • the composition of the monophase solid solution isolated is determined by the ratio of the amino phenols used.
  • the solid solution may be further purified by precipitation from an organic solvent or from a organic solvent -water mixture, for example, toluene, benzene, xylene, methanol, ethanol, iso-propanol, n-butanol, acetonitrile, dimethylformamide or mixtures of these solvents.
  • the crystal may be dissolved by heating to a temperature range of from room temperature to the boiling point of the chosen solvent, or above it under pressure in an autoclave. After complete dissolution the crystal may be precipitated with stirring or on standing.
  • All of the methods of preparation as hereinbefore described can be used to produce the monophase solid solutions of two or more fluoran compounds. Whether or not a monophase solid solution has been formed may be judged by powder X-ray diffraction analysis using K-Cu ⁇ rays.
  • a powder X-ray diffraction pattern of a monophase solid solution is substantially identical to that of one of the components, the 'host'. In general the 'host' is the compound forming the greater part of the mixture.
  • a monophase solid solution may also demonstrate a different melting point to that of an equivalent physical mixture. However, a change in melting point may also indicate a mixed crystal has been formed, thus melting point should only be considered in conjunction with powder X-ray diffraction when assessing whether or not a monophase solid solution has been formed.
  • Preferred developers are 4,4'-cyclohexylidene bisphenol, 4,4'-isopropylidene bisphenol, 2,2- bis-(4-hydroxyphenyl)-4-methylpentane, 2,2-dimethyl-3,3-di(4-hydroxyphenyl)butane, 1 - phenyl-1 ,1-bis(4-hydroxyphenyl)butane, 4-phenyl-2,2-bis(4-hydroxyphenyl)butane, 1-phenyl- 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4'-hydroxy-3'-methylphenyl)-4-methylpentane, 2,2- bis(4'-hydroxy-3'-tert-butyllphenyl)-4-methylpentane, 4,4'-sec-butylidene-bis (2- methylphenol), 4,4'-isopropylidene-bis (2-tert-butylphenol), 2,2-bis(4'-hydroxy-3'- isopropylpheny
  • Highly preferred developers are 4,4'-isopropylidene bisphenol, 2,2-bis-(4-hydroxyphenyl)-4- methylpentane, 2,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-diallyldiphenyl sulfone, 4,4'-bis (p-toluenesulphonylaminocarbonylamino) diphenylmethane, N-p-toluenesulphonyl-N'-phenyl urea and bis(1 ,2-dihydro-1 ,5-dimethyl-2- phenyl-3H-pyrazol-3-one-O)bis(thiocyanato-N) zinc and mixtures thereof.
  • the heat sensitive recording material of the invention can contain a stabiliser.
  • Suitable stabilisers for use in heat sensitive recording materials include 2,2'- methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis(4-ethyl-6-tert-butylphenol), 4,4'-butylidene-bis(3-methyl-6-tert-butylphenol), 4,4'-thio-bis(2-tert-butyl-5-methylphenol), 1 ,1 ,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1 ,1 ,3-tris(2-methyl-4-hydroxy-5- cyclohexylphenyl) butane, bis (3-tert-butyl-4-hydroxy-6-methylphenyl) sulfone, bis (3,5- dibromo-4-hydroxyphenyl) sulfone, 4,4'-sulfinyl bis (2-tert-butyl-5-methylphenol), 2,2'- methylene bis (4,6
  • Preferred stabilisers are 4,4'-butylidene-bis(3-methyl-6-tert-butylphenol), 4,4'-thio-bis(2-tert- butyl-5-methylphenol), 1 ,1 ,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1 ,1,3-tris(2- methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4-benzyloxy-4'-(2-methylglycidyloxy) diphenyl sulfone and mixtures thereof.
  • the heat sensitive recording material of the invention can be prepared according to conventional methods. For example, at least one colour forming compound, at least one developer and at least one sensitiser are pulverised separately in water or a suitable dispersing medium, such as aqueous polyvinyl alcohol, to form an aqueous or other dispersion. If desired a stabiliser is treated in the same manner.
  • the fine particle dispersions thus obtained are combined and then mixed with conventional amounts of binder, filler and lubricant.
  • binders used for the heat sensitive recording material includes polyvinyl alcohol (fully and partially hydrolysed), carboxy, amide, sulfonic and butyral modified polyvinyl alcohols, derivatives of cellulose such as hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, carboxymethyl cellulose and acetyl cellulose, copolymer of styrene-maleic anhydride, copolymer of styrene-butadiene, polyvinyl chloride, polyvinyl acetate, polyacrylamide, polyamide resin and mixtures thereof.
  • Exemplary fillers which can be used include calcium carbonate, kaolin, calcined kaolin, aluminium hydroxide, talc, titanium dioxide, zinc oxide, silica, polystyrene resin, urea- formaldehyde resin, hollow plastic pigment and mixtures thereof.
  • Representative lubricants for use in heat sensitive recording materials include dispersions or emulsions of stearamide, methylene bisstearamide, polyethylene, carnauba wax, paraffin wax, zinc stearate or calcium stearate and mixtures thereof.
  • Other additives can also be employed, if necessary.
  • Such additives are for example fluorescent whitening agents and ultraviolet absorbers.
  • the coating liquid so obtained can be applied to a suitable substrate such as paper, plastic sheet and resin coated paper, and used as the heat sensitive recording material.
  • a suitable substrate such as paper, plastic sheet and resin coated paper
  • the system of the invention can be employed for other end use applications using colour forming materials, for example, a temperature indicating material.
  • the quantity of the coating is usually 2 to 10 g/m 2 .
  • thermosensitive colouring layer can in addition contain a protective layer and, if desired, an undercoat layer.
  • the undercoat layer may be interposed between the substrate and the thermosensitive colouring layer.
  • the protective layer usually comprises a water-soluble resin in order to protect the thermosensitive colouring layer. If desired, the protective layer may contain water-soluble resins in combination with water-insoluble resins.
  • resins conventional resins can be employed.
  • polyvinyl alcohol starch and starch derivatives
  • cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose and ethylcellulose
  • sodium polyacrylate polyvinyl pyrrolidone
  • polyacrylamide/acrylic acid ester copolymers acrylamide/acrylic acid ester/methacrylic acid copolymers
  • alkali metal salts of styrene/maleic anhydride copolymers alkali metal salts of isobutylene/maleic anhydride copolymers
  • polyacrylamide sodium alginate; gelatin; casein; water-soluble polyesters and carboxyl-group-modified polyvinyl alcohols.
  • the protective layer may also contain a water-resisting agent such as a polyamide resin, melamine resin, formaldehyde, glyoxal or chromium alum. Typical amounts of water-resisting agents in the protective layer are 0.2 to 1.0 part by weight.
  • the protective layer may contain fillers, such as finely-divided inorganic powders, e.g. of calcium carbonate, silica, zinc oxide, titanium oxide, aluminium hydroxide, zinc hydroxide, barium sulphate, clay, talc, surface-treated calcium or silica, or a finely- divided organic powder of, e.g., a urea-formaldehyde resin, a styrene/ methacrylic acid copolymer or polystyrene.
  • fillers such as finely-divided inorganic powders, e.g. of calcium carbonate, silica, zinc oxide, titanium oxide, aluminium hydroxide, zinc hydroxide, barium sulphate, clay, talc, surface-treated calcium or silica, or a finely- divided organic powder of, e.g., a urea-formaldehyde resin, a styrene/ methacrylic acid copolymer or poly
  • the undercoat layer usually contains as its main components a binder resin and a filler.
  • binder resins for use in the undercoat layer are: polyvinyl alcohol; starch and starch derivatives; cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose and ethylcellulose; sodium polyacrylate; polyvinyl pyrrolidone; polyacrylamide/acrylic acid ester copolymers; acrylamide/acrylic acid ester/methacrylic acid copolymers; alkali metal salts of styrene/maleic anhydride copolymers; alkali metal salts of isobutylene/maleic anhydride copolymers; polyacrylamide; sodium alginate; gelatin; casein; water-soluble polymers such as water-soluble polyesters and carboxyl-group-modified polyvinyl alcohols; polyvinyl acetate; polyurethanes; styrene/butadiene copolymers; polyacrylic acid; polyacrylic acid esters; vinyl chloride/vinyl
  • fillers for use in the undercoat layer are: finely-divided inorganic powders, e.g. of calcium carbonate, silica, zinc oxide, titanium oxide, aluminium hydroxide, zinc hydroxide, barium sulphate, clay, talc, surface-treated calcium or silica, and finely-divided organic powders of, e.g., urea-formaldehyde resins, styrene/methacrylic acid copolymers and polystyrene.
  • finely-divided inorganic powders e.g. of calcium carbonate, silica, zinc oxide, titanium oxide, aluminium hydroxide, zinc hydroxide, barium sulphate, clay, talc, surface-treated calcium or silica
  • finely-divided organic powders e.g., urea-formaldehyde resins, styrene/methacrylic acid copolymers and polystyrene.
  • the undercoat layer may contain a water-resisting agent. Examples of such agents are given above.
  • Dispersions A to C were prepared by grinding the compositions shown below in an attritor until an average particle size of 1 -1.5 ⁇ was attained.
  • Dispersion A (Colour Former) 3-dibutylamino-6-methyl-7-anilinofluoran 3.01 parts Polyvinyl alcohol (10% aqueous solution) 10.50 parts Water 6.49 parts
  • a thermal coating mixture was then prepared by combining together the following components: parts by weight Dispersion A 6.6
  • Tinopal® ABP-X fluorescent whitening agent 0.12 Water 2.48
  • This coating mixture was applied on one side of a base paper weighing 50 g/m 2 in a coating weight of about 5.0 g/m 2 and then dried.
  • the resulting sheet was calendered by means of a laboratory calender to produce a recording sheet with excellent background whiteness.
  • the heat sensitive recording paper obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water. Additionally, the recording paper obtained shows a high dynamic sensitivity.
  • Evaluation of water resistance was conducted by immersing a facsimile image in de-ionised water for 24 hours at room temperature and then observing the remaining image density. Evaluation of sensitivity was done using an Infotec fax machine 3301 at pulse widths of 0.30, 0.50, 0.68 and 1.00 milliseconds.
  • Evaluation of post application was conducted by observing the whiteness of the paper.
  • Evaluation of light resistance was conducted by inspecting the degree of yellowing of the uncoloured portion of the paper after exposure to 120 hours of artificial daylight.
  • Evaluation of heat and moisture resistance was conducted by examining the soiling of the uncoloured portion of paper after storage at 60°C and 50% relative humidity for one hour.
  • a heat sensitive recording material was prepared by the method described in example 1 with 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran being used as the colour former in place of 3-dibutylamino-6-methyl-7-anilinofluoran.
  • the heat sensitive recording paper thus obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water.
  • a heat sensitive recording material was prepared by the method described in example 1 with a monophase solid solution of 3-dibutylamino-6-methyl-7-anilinofluoran (9 parts) and 3- diethylamino-6-methyl-7-anilinofluoran (1 part) being used as the colour former in place of 3- dibutylamino-6-methyl-7-anilinofluoran in dispersion A.
  • sensitiser a mixture of 90 parts 1 ,4-diproprionyloxybenzene and 10 parts 1 ,4 diacetoxybenzene was used in place of 1,4- diproprionyloxybenzene in dispersion C.
  • the heat sensitive recording paper thus obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water.
  • a heat sensitive recording material was prepared by the method described in example 1 with a mixture of 90 parts 1 ,4-diproprionyloxybenzene and 10 parts 1,4 diacetoxybenzene being used as sensitiser in place of 1 ,4-diproprionyloxybenzene in dispersion C.
  • the heat sensitive recording paper thus obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water.
  • the following Table 1 shows the colour former/developer/sensitiser combinations that were used in each example.
  • the heat sensitive recording material was prepared by the method described in example 1. In all cases, the heat sensitive recording paper thus obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water.

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Abstract

A heat sensitive recording material, comprising a) at least one colour forming compound selected from the group consisting of 3- diethylamino- 6-methyl- 7-(3- methylanilino) fluoran, 3- dibutylamino- 6-methyl- 7-anilinofluoran, 3- dipentylamino-6- methyl-7- anilinofluoran, 3-(N- methyl-N- propylamino)-6- methyl-7- anilinofluoran, 3- (N-ethyl-p- toluidino)- 6-methyl-7- anilinofluoran and 3-(N- ethyl-N- isoamylamino)-6-methyl- 7-anilinofluoran; or a monophase solid solution comprising at least two colour forming compounds; b) at least one sensitiser of formula (1), wherein R and R' are identical or different from each other and each represent C1-C6alkyl; and c) at least one developer.

Description

Heat Sensitive Recording Material
The present invention relates to heat sensitive recording materials. It more particularly relates to such recording material in the form of sheets coated with colour-forming systems comprising a colourless or pale coloured electron donative compound (colour forming compound) and an organic electron acceptor (developer).
Heat sensitive recording has conventionally been used as a system for recording transferred information through the mediation of heat, by utilising a colour reaction between a colour forming compound and a developer.
The properties which are most desirable in a colour forming material, in addition to the effective development of colour, are thermal response, background whiteness and image stability, especially light fastness of the developed colour, heat fastness of the developed colour and water fastness of the developed colour.
A need exists to improve the above properties and to improve the archival capabilities of such recording materials. It is an object of the present invention to provide heat sensitive recording materials with improved properties, especially water fastness.
The present invention is directed to heat sensitive recording material, comprising a) at least one colour forming compound selected from the group consisting of 3-diethylamino-6-methyl-7-(3-methylanilino) fluoran, 3-dibutylamino-6-methyl-7- anilinofluoran, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-propylamino)-6- methyl-7-anilinofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran and 3-(N-ethyl- N-isoamylamino)-6-methyl-7-anilinofluoran; or a monophase solid solution comprising at least two colour forming compounds; b) at least one sensitiser of the formula
Figure imgf000004_0001
wherein R and R' are identical or different from each other and each represent Cι-C6alkyl; and c) at least one developer.
Examples of R and R' are methyl, ethyl, n- or iso-propyl and n-, sec- or tert-butyl.
The substituents R and R' are identical or different from each other and each are preferably C C alkyl, especially methyl or ethyl, in particular ethyl.
Highly preferred are sensitisers wherein R and R' are identical.
Preferred sensitisers are those of the formula
Figure imgf000004_0002
wherein R and R' are as defined above, especially those of the formula
Figure imgf000005_0001
Figure imgf000005_0002
Of particular interest are sensitisers of the formula (3).
The sensitisers of the formula (1) can also be used in admixture with other known sensitisers or other sensitisers of the above formula (1). Preferred mixtures are those which contain more than one sensitiser of the above formula (1), especially a sensitiser of the formula (3) and a sensitiser of the formula (4).
If mixtures of sensitisers are used these contain preferably at least 40% by weight, especially 50% by weight, of sensitisers of the above formula (1). Highly preferred are mixtures which contain at least 60% by weight, especially 80% by weight, of sensitisers of the above formula (1).
It is preferred to use at least one colour forming compound selected from the group consisting of 3-dibutylamino-6-methyl-7-anilinofluoran, 3-dipentylamino-6-methyl-7-anilinofluoran and 3- (N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran, especially at least one colour forming compound selected from the group consisting of 3-dibutylamino-6-methyl-7-anilinofluoran and 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran. Highly preferred as colour forming compound is 3-dibutylamino-6-methyl-7-anilinofluoran, especially in combination with a sensitiser of the formula (3).
All of the above colour forming compounds can be used singly or as a mixture with other colour forming compounds such as triphenylmethanes, lactones, fluorans, benzoxazines and spiropyrans in order to adjust the developed hue if desired; or they may also be used together with further black colour forming compounds. Other colour forming compounds which may be used as above, include but are not limited to; 3-diethylamino-6-methylfluoran, 3-dimethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3- diethylamino-6-methyl-7-(2,4-dimethylanilino) fluoran, 3-diethylamino-6-methyl-7- chlorofluoran, 3-diethylamino-6-methyl-7-(3-trifluoromethylanilino) fluoran, 3-diethylamino-6- methyl-7-(2-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-chloroanilino) fluoran, 3- diethylamino-6-methyl-7-(2-fluoroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-n-octylanilino) fluoran, 3-diethylamino-7-(4-n-octylanilino) fluoran, 3-diethylamino-7-(n-octylamino) fluoran, 3-diethylamino-6-methyl-7-(dibenzylamino) fluoran, 3-diethylamino-7-(dibenzylamino) fluoran, 3-diethylamino-6-chloro-7-methylfluoran, 3-diethylamino-7-t-butylfluoran, 3- diethylamino-7-carboxyethylfluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-diethylamino- 6-methyl-7-(3-methylanilino) fluoran, 3-diethylamino-6-methyl-7-(4-methylanilino) fluoran, 3- diethylamino-6-ethoxyethyl-7-anilinofluoran, 3-diethylamino-7-methylfluoran, 3-diethylamino- 7-chlorofluoran, 3-diethylamino-7-(3-trifluoromethylanilino) fluoran, 3-diethylamino-7-(2- chloroanilino) fluoran, 3-diethylamino-7-(2-fIuoroanilino) fluoran, 3-diethylamino-benzo[a] fluoran, 3-diethylamino-benzo[c] fluoran, 3-dibutylamino-6-methyl fluoran, 3-dibutylamino-6- methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-(2,4-dimethylanilino) fluoran, 3- dibutylamino-6-methyl-7-(2-chloroanilino) fluoran, 3-dibutylamino-6-methyl-7-(4-chloroanilino) fluoran, 3-dibutylamino-6-methyl-7-(2-fluoroanilino) fluoran, 3-dibutylamino-6-methyl-7-(3- trifluoromethylanilino) fluoran, 3-dibutylamino-6-ethoxyethyl-7-anilinofluoran, 3-dibutylamino- 6-chloro-anilinofluoran, 3-dibutylamino-6-methyl-7-(4-methylanilino) fluoran, 3-dibutylamino- 7-(2-chloroanilino) fluoran, 3-dibutylamino-7-(2-fluoroanilino) fluoran, 3-dipentylamino-6- methyl-7-anilinofluoran, 3-dipentylamino-6-methyl-7-(2-chloroanilino) fluoran, 3- dipentylamino-7-(3-trifluoromethylanilino) fluoran, 3-dipentylamino-6-chloro-7-anilinofluoran, 3-dipentylamino-7-(4-chloroanilino) fluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 3- piperidino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-propylamino)-6-methyl-7-anilinofluoran, 3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-cyclohexylamino)-6- methyl-7-anilinofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N- isoamylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-isoamylamino)-6-chloro-7- anilinofluoran, 3-(N-ethyl-N-tetrahydrofurfurylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N- isobutylamino)-6-methyl-7-anilinofluoran, 3-(N-butyl-N-isoamylamino)-6-methyl-7- anilinofluoran, 3-(N-isopropyl-N-3-pentylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N- ethoxypropylamino)-6-methyl-7-anilinofluoran, 3-cyclohexylamino-6-chlorofluoran, 7-methyl- 3-p-(p-dimethylaminophenyl)aminoanilinofluoran, 7-methoxy-3-p-(p- dimethylaminophenyl)aminoanilinofluoran, 7-chloro-6-methyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 7-diethylamino-3-p-(p- dimethylaminophenyl)aminoanilinofluoran, 7-phenyl-3-methyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 7-benzyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 6-methyl-3-p-(p- dimethylaminophenyl)aminoanilinofluoran, 3-diethylamino-6-p-(p- diethylaminophenyl)aminoanilinofluoran, 3-diethylamino-6-p-(p- dibutylaminophenyl)aminoanilinofluoran, 2,4-dimethyl-6-[(4-dimethylamino)anilino] fluoran, 3,6,6'-tris(dimethylamino)spiro[fluorene-9,3'-phthalide], 3,6,6'- tris(diethylamino)spiro[fluorene-9,3'-phthalide], 3,3-bis(p-dimethylaminophenyl)-6- dimethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, 3,3-bis-[2-(p- dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl-4,5,6,7-tetrabromophthalide, 3,3-bis-[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl-4,5,6,7-tetrachlorophthalide, 3,3-bis[1 ,1-bis(4-pyrrolidinophenyl)ethylene-2-yl]-4,5,6,7-tetrabromophthalide, 3,3-bis-[1 -(4- methoxyphenyl)-1-(4-pyrridinophenyl)ethylene-2-yl]-4,5,6,7-tetrachlorophthalide, 3-(4- diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(4- diethylamino-2-ethoxyphenyl)-3-(1-octyl-2-methylindole-3-yl)-4-azaphthalide, 3-(4- cyclohexylethylamino-2-methoxyphenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3,3- bis(1-ethyl-2-methylindole-3-yl) phthalide, 3,3-bis(1-octyl-2-methylindole-3-yl) phthalide, mixture of 2-phenyl-4-(4-diethylaminophenyl)-4-(4-methoxyphenyl)-6-methyl-7- dimethylamino-3, 1 -benzoxazine and 2-phenyl-4-(4-diethylaminophenyl)-4-(4- methoxyphenyl)-8-methyl-7-dimethylamino-3,1 -benzoxazine, 4,4'-[ 1 - methylethylidene)bis(4,1-phenyleneoxy-4,2-quinazolinediyl)]bis[N,N-diethylbenzenamine], bis(N-methyldiphenylamine)-4-yl-(N-butylcarbazole)-3-yl-methane and mixtures thereof.
Examples of such mixtures are a mixture of 3-diethylamino-6-methyl-7-anilino fluoran and 3- dibutylamino-6-methyl-7-anilinofluoran, a mixture of 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran and 3-dibutylamino-6- methyl-7-anilinofluoran, and a mixture of 3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofluoran and 3-dibutylamino-6- methyl-7-anilinofluoran.
If mixtures of colour forming compounds are used these mixtures contain preferably at least 40% by weight, especially at least 60% by weight, of the colour forming compounds given at the beginning under a) (3-diethylamino-6-methyl-7-(3-methylanilino) fluoran, 3-dibutylamino- 6-methyl-7-anilinofluoran, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-(N-methyl-N- propylamino)-6-methyl-7-aniIinofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran). Highly preferred are mixtures which contain at least 80% by weight, especially at least 90% by weight, of the colour forming compounds given at the beginning.
It is also possible to use so-called monophase solid solutions comprising at least two colour forming compounds.
A monophase (or single-phase or guest-host) solid solution possesses a crystal lattice which is identical with the crystal lattice of one of its components. One component is embedded as the 'guest' in the crystal lattice of the other component, which acts as the 'host'. The X-ray diffraction pattern of such a monophase solid solution is substantially identical to that of one of the components, called the 'host'. Within certain limits, different proportions of the components produce almost identical results.
In the literature, the definitions by the various authors, such as, G.H.Van't Hoff,
A.I.Kitaigorodsky and A.Whitacker for solid solutions and mixed crystals are often contradictory, (cf, e.g. 'Analytical Chemistry of Synthetic Dyes', Chapter 10/page 269, Editor
K.Venkataraman, J.Wiley, New York, 1977).
The term 'monophase solid solution' or 'multiphase solid solution' or mixed crystal', as define herein, therefore, should be taken from the following definitions, which have been adapted to the current improved state of knowledge of such systems:
A monophase (or single-phase or guest-host) solid solution possesses a crystal lattice which is identical with the crystal lattice of one of its components. One component is embedded as the 'guest' in the crystal lattice of the other component, which acts as the 'host'. The X-ray diffraction pattern of such a monophase solid solution is substantially identical to that of one of the components, called the 'host'. Within certain limits, different proportions of the components produce almost identical results.
A multiphase solid solution possesses no precise, uniform crystal lattice. It differs from a physical mixture of its components in that the crystal lattice of at least one of its components is partially or competely altered. In comparison to a physical mixture of the components, which gives an X-ray diffraction diagram that is additive of the diagrams seen for the individual components. The signals in the X-ray diffraction diagram of a multiphase solid solution are broadened, shifted or altered in intensity. In general, different proportions of the components produce different results.
A mixed crystal (or solid compound type) solid solution possesses a precise composition and a uniform crystal lattice, which is different from the crystal lattices of all its components. If different proportions of the components lead, within certain limits, to the same result, then a solid solution is present in which the mixed crystal acts as a host.
For the avoidance of doubt it may also be pointed out that, inter alia, there may also be amorphous structures and mixed aggregates consisting of different particles of different physical type, such as, for example, an aggregate of different components each in pure crystal modification. Such amorphous structures and mixed aggregates cannot be equated with either solid solutions or mixed crystals, and possess different fundamental properties.
As hereinbefore detailed, the monophase solid solutions comprise a plurality of colour compounds. Suitable colour forming materials which may be included in the solid solutions according to the present invention, include but are not limited to; 3-diethylamino-6- methylfluoran, 3-dimethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7- anilinofluoran, 3-diethylamino-6-methyl-7-(2,4-dimethylanilino) fluoran, 3-diethylamino-6- methyl-7-chlorofluoran, 3-diethylamino-6-methyl-7-(3-trifluoromethylanilino) fluoran, 3- diethylamino-6-methyl-7-(2-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-(2-fluoroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-n- octylanilino) fluoran, 3-diethylamino7-(4-n-octylanilino) fluoran, 3-diethylamino-7-(4-n- octylamino) fluoran, 3-diethylamino-6-methyl-7-(dibenzylamino) fluoran, 3-diethylamino-7- (dibenzylamino) fluoran, 3-diethylamino-6-chloro-7-methylfluoran, 3-diethylamino-7-t- butylfluoran, 3-diethylamino-7-carboxyethylfluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-diethylamino-6-methyl-7-(3-methylaniIino) fluoran, 3-diethylamino-6-methyl-7-(4- methylanilino) fluoran, 3-diethylamino-6-ethoxyethyl-7-anilinofluoran, 3-diethylamino-7- methylfluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-7-(3-trifluoromethylanilino) fluoran, 3-diethylamino-7-(2-chloroanilino) fluoran, 3-diethylamino-7-(2-fluoroanilino) fluoran, 3-diethylamino-benzo[a] fluoran, 3-diethylamino-benzo[c] fluoran, 3-dibutylamino-6-methyl fluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-(2,4- dimethylanilino) fluoran, 3-dibutylamino-6-methyl-7-(2-chloroanilino) fluoran, 3-dibutylamino- 6-methyl-7-(4-chloroanilino) fluoran, 3-dibutylamino-6-methyl-7-(2-fluoroanilino) fluoran, 3- dibutylamino-6-methyl-7-(3-trifluoromethylanilino) fluoran, 3-dibutylamino-6-ethoxyethyl-7- anilinofluoran, 3-dibutylamino-6-chloro-anilinofluoran, 3-dibutylamino-6-methyl-7-(4- methylanilino) fluoran, 3-dibutylamino-7-(2-chloroanilino) fluoran, 3-dibutylamino-7-(2- fluoroanilino) fluoran, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-dipentylamino-6-methyl-7- (2-chloroanilino) fluoran, 3-dipentylamino-7-(3-trifluoromethylanilino) fluoran, 3- dipentylamino-6-chloro-7-anilinofluoran, 3-dipentylamino-7-(4-chloroanilino) fluoran, 3- pyrrolidino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7-anilinofluoran, 3-(N-methyl-N- propylamino)-6-methyl-7-anilinofluoran, 3-(N-methyl-N-cyclohexylamino)-6-methyl-7- anilinofluoran, 3-(N-ethyl-N-cyclohexylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-p- toluidino)-6-methyI-7-anilinofluoran, 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran, 3- (N-ethyl-N-isoamylamino)-6-chloro-7-anilinofluoran, 3-(N-ethyl-N-tetrahydrofurfurylamino)-6- methyl-7-anilinofluoran, 3-(N-ethyl-N-isobutylamino)-6-methyl-7-aniIinofluoran, 3-(N-butyl-N- isoamylamino)-6-methyl-7-anilinofluoran, 3-(N-isopropyl-N-3-pentylamino)-6-methyl-7- anilinofluoran, 3-(N-ethyl-N-ethoxypropylamino)-6-methyl-7-anilinofluoran, 3- cyclohexylamino-6-chlorofluoran, 7-methyl-3-p-(p-dimethylaminophenyl)aminoanilinofluoran, 7-methoxy-3-p-(p-dimethylaminophenyl)aminoanilinofluoran, 7-chloro-6-methyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 7-diethylamino-3-p-(p- dimethylaminophenyl)aminoanilinofluoran, 7-phenyl-6-methyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 7-benzyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 3-methyl-6-p-(p- dimethylaminophenyl)aminoanilinofluoran, 3-diethylamino-6-p-(p- diethylaminophenyl)aminoanilinofluoran, 3-diethylamino-6-p-(p- dibutylaminophenyl)aminoanilinofluoran, 2,4-dimethyl-6-[(4-dimethylamino)anilino] fluoran, 3,6,6'-tris(dimethylamino)spiro[fluorene-9,3'-phthalide], 3,6,6'- tris(diethylamino)spiro[fluorene-9,3'-phthalide], 3,3-bis(p-dimethylaminophenyl)-6- dimethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, 3,3-bis-[2-(p- dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl-4,5,6,7-tetrabromophthalide, 3,3-bis-[2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl-4,5,6,7-tetrachlorophthalide, 3,3-bis[1 ,1 -bis(4-pyrrolidinophenyl)ethylene-2-yl]-4,5,6,7-tetrabromophthalide, 3,3-bis-[1 -(4- methoxyphenyl)-1-(4-pyrridinophenyl)ethylene-2-yl]-4,5,6,7-tetrachlorophthalide, 3-(4- diethylamino-2-ethoxyphenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3-(4- diethyiamino-2-ethoxyphenyl)-3-(1-octyl-2-methylindole-3-yl)-4-azaphthalide, 3-(4- cyclohexylethylamino-2-methoxyphenyl)-3-(1-ethyl-2-methylindole-3-yl)-4-azaphthalide, 3,3- bis(1-ethyl-2-methylindole-3-yl) phthalide, 3,3-bis(1-octyl-2-methylindole-3-yl) phthalide, mixture of 2-phenyl-4-(4-diethylaminophenyl)-4-(4-methoxyphenyl)-6-methyl-7- dimethylamino-3, 1 -benzoxazine and 2-phenyl-4-(4-diethylaminophenyl)-4-(4- methoxyphenyl)-8-methyl-7-dimethylamino-3,1 -benzoxazine, 4,4'-[1 - methylethyIidene)bis(4,1-phenyleneoxy-4,2-quinazolinediyl)]bis[N,N-diethylbenzenamine], bis(N-methyldiphenylamine)-4-yl-(N-butylcarbazole)-3-yl-methane.
Preferred herein are monophase solid solutions containing, as one of the components, a fluoran compound such as 3-diethylamino-6-methylfluoran, 3-dimethylamino-6-methyl-7- anilinofluoran, 3-diethylamino-6-methyI-7-anilinofIuoran, 3-diethylamino-6-methyl-7-(2,4- dimethylanilino) fluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-6-methyl-7- (3-trifluoromethylanilino) fluoran, 3-diethylamino-6-methyl-7-(2-chloroanilino) fluoran, 3- diethylamino-6-methyl-7-(4-chloroanilino) fluoran, 3-diethylamino-6-methyl-7-(2-fluoroanilino) fluoran, 3-diethylamino-6-methyl-7-(4-n-octylanilino) fluoran, 3-diethylamino -7-(4-n- octylanilino) fluoran, 3-diethylamino-7-(n-octylamino) fluoran, 3-diethylamino-6-methyl-7- (dibenzylamino) fluoran, 3-diethylamino-7-(dibenzylamino) fluoran, 3-diethylamino-6-chloro- 7-methylfluoran, 3-diethylamino-7-t-butylfluoran, 3-diethylamino-7-carboxyethylfluoran, 3- diethylamino-6-chloro-7-anilinofluoran, 3-diethylamino-6-methyl-7-(3-methylanilino) fluoran, 3-diethylamino-6-methyl-7-(4-methylanilino) fluoran, 3-diethylamino-6-ethoxyethyl-7- anilinofluoran, 3-diethylamino-7-methylfluoran, 3-diethylamino-7-chlorofluoran, 3- diethylamino-7-(3-trifluoromethylanilino) fluoran, 3-diethylamino-7-(2-chloroanilino) fluoran, 3-diethylamino-7-(2-fluoroanilino) fluoran, 3-diethylamino-benzo[a] fluoran, 3-diethylamino- benzo[c] fluoran, 3-dibutylamino-6-methyl fluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-(2,4-dimethylanilino) fluoran, 3-dibutylamino-6-methyl-7-(2- chloroanilino) fluoran, 3-dibutylamino-6-methyl-7-(4-chloroanilino) fluoran, 3-dibutylamino-6- methyl-7-(2-fluoroanilino) fluoran, 3-dibutylamino-6-methyl-7-(3-trifluoromethylanilino) fluoran, 3-dibutylamino-6-ethoxyethyl-7-anilinofluoran, 3-dibutylamino-6-chloro-anilinofluoran, 3-dibutylamino-6-methyl-7-(4-methylanilino) fluoran, 3-dibutylamino-7-(2-chloroanilino) fluoran, 3-dibutylamino-7-(2-fluoroanilino) fluoran, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-dipentylamino-6-methyl-7-(2-chloroanilino) fluoran, 3-dipentylamino-7-(3- trifluoromethylanilino) fluoran, 3-dipentylamino-6-chloro-7-anilinofluoran, 3-dipentylamino-7- (4-chloroanilino) fluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 3-piperidino-6-methyl-7- anilinofluoran, 3-(N-methyl-N-propylamino)-6-methyl-7-anilinofluoran, 3-(N-methyl-N- cyclohexylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-cyclohexylamino)-6-methyl-7- anilinofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran, 3-(N-ethyI-N-isoamylamino)- 6-methyl-7-anilinofluoran, 3-(N-ethyl-N-isoamylamino)-6-chloro-7-anilinofluoran, 3-(N-ethyl- N-tetrahydrofurfurylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-isobutylamino)-6-methyl- 7-anilinofluoran, 3-(N-butyl-N-isoamylamino)-6-methyl-7-anilinofluoran, 3-(N-isopropyl-N-3- pentylamino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-ethoxypropylamino)-6-methyl-7- anilinofluoran, 3-cyclohexylamino-6-chlorofluoran, 7-methyl-3-p-(p- dimethylaminophenyl)aminoanilinofluoran, 7-methoxy-3-p-(p- dimethylaminophenyl)aminoanilinofluoran, 7-chloro-6-methyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 7-diethylamino-3-p-(p- dimethylaminophenyl)aminoanilinofluoran, 7-phenyl-6-methyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 7-benzyl-3-p-(p- phenylaminophenyl)aminoanilinofluoran, 3-methyl-6-p-(p- dimethylaminophenyl)aminoanilinofluoran, 3-diethylamino-6-p-(p- diethylaminophenyl)aminoanilinofluoran, 3-diethylamino-6-p-(p- dibutylaminophenyl)aminoanilinofluoran, 2,4-dimethyl-6-[(4-dimethylamino)anilino] fluoran.
Highly preferred monophase solid solutions are composed of at least two fluoran compounds of the general formula (5)
Figure imgf000013_0001
wherein, Ri and R2 independently represent hydrogen; a straight or branched chain alkyl of 1-18 carbon, a secondary alkyl with respect to the carbon atom bonded to the nitrogen atom of 3-13 carbon atoms; a cycloalkyl of 4-8 carbon atoms or a phenyl, both of which may be substituted by at least one substituent selected from the group consisting of halogen atoms and alkyls having 1-4 carbon atoms, an aralkyl of 7-10 carbon atoms. Alternatively, Ri and R2, together with the adjacent nitrogen atom may form a heterocyclic ring. R3 is hydrogen; an alkyl of 1-4 carbon atoms; an alkoxy of 1-4 carbon atoms; a phenyl; a substituted phenyl or a halogen. R4 is an alkyl group of 1-18 carbon atoms; a carboxyalkyl of 1-18 carbon atoms; a carboxycycloalkyl of 4-8 carbon atoms; an alkylamino of 1-18 carbon atoms; a cycloalkylamino of 4-8 carbon atoms; a dialkylamino or dicycloalkylamino as previously defined; an arylamino; a substituted arylamino; an aralkylamino of 7-10 carbon atoms; a diaralkylamino as previously defined. R5 is an alkyl of 1-18 carbon atoms; a carboxy alkyl of 1-18 carbon atoms or a halogen.
The ratio of the components being in the range 0.1-99.9% by mole, especially 0.1-30%.
Of particular interest are the following monophase solid solutions:
3-dibutylamino-6-methyl-7-anilinofluoran and 3-diethylamino-6-methyl-7-anilinofluoran;
3-dibutylamino-6-methyl-7-anilinofluoran and 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran;
3-dibutylamino-6-methyl-7-anilinofluoran and 3-N-cyclohexyl-N-methylamino-6-methyl-7- anilinofluoran;
3-N-isoamyl-N-ethylamino-6-methyl-7-anilinofluoran and 3-diethylamino-6-methyl-7- anilinofluoran;
3-diethylamino-6-methyl-7-anilinofluoran and 3-N-propyl-N-methylamino-6-methyl-7- aniiinofluoran; 3-diethylamino-6-methyl-7-(3-tolyl)aminofluoran and 3-diethylamino-6-methyl-7- anilinofluoran;
3-dibutylamino-6-methyl-7-anilinofluoran and 3,3-bis(1 -octyl-2-methylindol-3-yl)phthalide;
3-dibutylamino-6-methyl-7-anilinofluoran and mixture of 2-phenyl-4-(4-diethylaminophenyl)-4-
(4-methoxyphenyl)-6-methyl-7-dimethylamino-3,1 -benzoxazine and 2-phenyl-4-(4- diethylaminophenyl)-4-(4-methoxyphenyl)-8-methyl-7-dimethylamino-3,1 -benzoxazine;
3-dibutylamino-6-methyl-7-anilinofluoran and 4,4'-[1-methylethylidene)bis(4,1-phenyleneoxy-
4,2-quinazolinediyl)]bis[N,N-diethylbenzenamine].
In the above monophase solid solutions the first compound is in a molar ratio of 75 to 99.9% by mole, the second compound is in a ratio of 25 to 0.1% by mole.
Examples of monophase solid solutions comprising two components A and B in the stated ratios are: 3-dibutylamino-6-methyl-7-anilinofluoran (99.9%), 3-diethylamino-6-methyl-7- anilinofluoran (0.1%);
3-dibutylamino-6-methyl-7-anilinofluoran (99%), 3-diethylamino-6-methyl-7-anilinofluoran
(1%);
3-dibutylamino-6-methyl-7-anilinofluoran (95%), 3-diethylamino-6-methyl-7-anilinofluoran
(5%);
3-dibutylamino-6-methyl-7-anilinofluoran (90%), 3-diethylamino-6-methyl-7-anilinofluoran
(10%);
3-dibutylamino-6-methyl-7-anilinofluoran (85%), 3-diethylamino-6-methyl-7-anilinofluoran
(15%);
3-dibutylamino-6-methyl-7-anilinofluoran (80%), 3-diethylamino-6-methyl-7-anilinofluoran
(20%);
3-dibutylamino-6-methyl-7-anilinofluoran (95%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (5%);
3-dibutylamino-6-methyl-7-anilinofluoran (90%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (10%);
3-dibutylamino-6-methyl-7-anilinofluoran (80%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (20%);
3-dibutylamino-6-methyl-7-anilinofluoran (90%), 3-N-cyclohexyl-N-methylamino-6-methyl-7- anilinofluoran (10%);
3-diethylamino-6-methyl-7-anilinofluoran (90%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (10%); 3-diethylamino-6-methyl-7-anilinofluoran (80%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (20%);
3-diethylamino-6-methyl-7-anilinofluoran (20%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (80%);
3-diethylamino-6-methyl-7-anilinofluoran (10%), 3-N-isoamyl-N-ethylamino-6-methyl-7- anilinofluoran (90%);
3-diethylamino-6-methyl-7-anilinofluoran (90%), 3-N-propyl-N-methylamino-6-methyl-7- anilinofluoran (10%);
3-diethylamino-6-methyl-7-anilinofluoran (80%), 3-N-propyl-N-methylamino-6-methyl-7- anilinofluoran (20%);
3-diethylamino-6-methyl-7-anilinofluoran (20%), 3-N-propyl-N-methyIamino-6-methyl-7- anilinofluoran (80%);
3-diethylamino-6-methyl-7-anilinofluoran (10%), 3-N-propyl-N-methylamino-6-methyl-7- anilinofluoran (90%);
3-diethylamino-6-methyl-7-anilinofluoran (10%), 3-diethylamino-6-methyl-7-(3- tolyl)aminofluoran (90%);
3-diethylamino-6-methyl-7-anilinofluoran (20%), 3-diethylamino-6-methyl-7-(3- tolyl)aminofluoran (80%);
3-dibutylamino-6-methyl-7-anilinofluoran (90%), 3,3-bis(1 -octyl-2-methylindol-3-yl)phthalide
(10%);
3-dibutylamino-6-methyl-7-anilinofluoran (80%), 3,3-bis(1 -octyl-2-methylindol-3- yl)phthalide(20%);
3-dibutylamino-6-methyl-7-anilinofluoran (90%), mixture of 2-phenyl-4-(4- diethylaminophenyl)-4-(4-methoxyphenyl)-6-methyl-7-dimethylamino-3,1 -benzoxazine and 2- phenyl-4-(4-diethylaminophenyl)-4-(4-methoxyphenyl)-8-methyl-7-dimethylamino-3,1- benzoxazine(10%);
3-dibutylamino-6-methyl-7-anilinofluoran (80%), mixture of 2-phenyl-4-(4- diethylaminophenyl)-4-(4-methoxyphenyl)-6-methyl-7-dimethylamino-3,1 -benzoxazine and 2- phenyl-4-(4-diethylaminophenyl)-4-(4-methoxyphenyl)-8-methyl-7-dimethylamino-3,1- benzoxazine(20%);
3-dibutylamino-6-methyl-7-anilinofluoran (90%), 4,4'-[1 -methylethylidene)bis(4,1 - phenyleneoxy-4,2-quinazolinediyl)]bis[N,N-diethylbenzenamine](10%);
3-dibutylamino-6-methyl-7-anilinofluoran (80%), 4,4'-[1 -methylethylidene)bis(4,1 - phenyleneoxy-4,2-quinazolinediyl)j3is[N,N-diethylbenzenamine] (20%). Of particular interest are monophase solid solutions wherein the ratio of the colour forming compounds given at the beginning under a) is preferably 70 to 99.9% by mole, especially 80 to 99.9% by mole.
The monophase solid solutions can be used singly or as a mixture with other colour forming compounds such as triphenylmethanes, lactones, fluorans, benzoxazines and spiropyrans in order to adjust the developed hue if desired; or they may also be used together with further black colour forming compounds. Examples of such other colour forming compounds are given hereinbefore.
The monophase solid solutions can be prepared by a variety of methods. One such method is the recrystallisation method wherein a physical mixture of the desired components is dissolved, with or without heating, in a suitable solvent or solvent mixture. Suitable solvents include but are not limited to toluene, benzene, xylene, dichlorobenzene, chlorobenzene, 1 ,2-dichloroethane, methanol, ethanol, iso-propanol, n-butanol, acetonitrile, dimethylformamide or mixtures of these solvents with each other and with water. The monophase solid solution is then isolated by crystallisation from the solvent or solvent mixture. This can be brought about by cooling, standing, addition of a further solvent to promote crystallisation or concentration by standard means such as distillation, steam distillation and vacuum distillation. When the monophase solid solution is isolated by concentration it may be advantageous to do so in the presence of a small amount of base, to improve the visual aspect of the isolated product.
Alternatively, monophase solid solutions can be prepared from mixtures of the appropriate starting materials. The technique can be used to produce mixtures of two or more fluorans or phthalides. For example, mixtures of two fluorans are produced by replacing a single starting material with two analogous materials to the same total molar concentration in the reaction. In the case of fluorans, these starting materials are derivatives of amino phenols, phthalic anhydrides, keto acids and diphenylamines.
The first method of preparation uses the reaction of an appropriate mixture of keto acids of formula (6) and compounds of formula (7) to give the desired monophase solid solution. Rr R5 have the meanings given previously and R6 is hydrogen or alkyl of 1-4 carbon atoms.
Figure imgf000017_0001
For instance, a two component monophase solution consisting of two compounds of general formula (5) may be prepared by reaction of;
i.Two different keto acids of general formula (6) with a single compound of general formula (7). ii.Two different compounds of general formula (7) with a single keto acid of formula
(6).
Compounds of general formula (6) are exemplified by, but not limited to; 2-hydroxy-4-N,N-di- methyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N,N-di-ethyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N,N-di-n-propyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N,N-di-n-butyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N,N-di-n-pentyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N,N-di-n-hexyi amino-2'- carboxybenzophenone, 2-hydroxy-4-N,N-diisopropyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N,N-disecbutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N,N-diisobutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N,N-diisoamyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N,methyl-N-cyclohexyl amino-2' -carboxybenzophenone, 2-hydroxy-4-N-methyl-N-phenyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N- (2-methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N-(3-methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N-(4-methylphenyl) amino-2'- carboxybenzophenone, 2-hydroxy-4-N-methyl-N-propyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-methyl-N-isopropyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N- butyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N-isobutyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-methyl-N-secbutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N-pentyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N-1 - methylbutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N-isoamyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-methyl-N-1 -methylpentyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-methyl-N-hexyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-methyl-N-tetrahydrofurylmethyl amino-2'-carboxybenzophenone, 2-hydroxy-4- N-methyl-N-ethoxypropyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N- cyclohexylmethyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-methyl-N-phenethyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-cyclohexyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-phenyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-ethyl-N-(2-methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl- N-(3-methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-(4- methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-propyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-isopropyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-ethyl-N-butyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-isobutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-secbutyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-pentyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-ethyl-N-1 -methylbutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N- isoamyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-1 -methylpentyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-hexyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-ethyl-N-tetrahydrofurylmethyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N- ethyl-N-ethoxypropyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N- cyclohexylmethyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-ethyl-N-phenethyl amino- 2'-carboxybenzophenone, 2-hydroxy-4-N-propyl-N-cyclohexyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-propyl-N-phenyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-propyl-N-(2-methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N- propyl-N-(3-methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-propyl-N-(4- methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-propyl-N-isopropyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-propyl-N-butyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-propyl-N-isobutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-propyl-N- secbutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-propyl-N-pentyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-propyl-N-1 -methylbutyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-propyl-N-isoamyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-propyl-N-1 -methylpentyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-propyl- N-hexyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-propyl-N-tetrahydrofurylmethyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-propyl-N-ethoxypropyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-propyl-N-cyclohexylmethyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-propyl-N-phenethyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N-cyclohexyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N- phenyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N-(2-methylphenyl) amino-2'- carboxybenzophenone, 2-hydroxy-4-N-butyl-N-(3-methylphenyl) amino-2'- carboxybenzophenone, 2-hydroxy-4-N-butyl-N-(4-methylphenyl) amino-2'- carboxybenzophenone, 2-hydroxy-4-N-butyl-N-propyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-butyl-N-isopropyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N- isobutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N-secbutyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-butyl-N-pentyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-butyl-N-1 -methylbutyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N- isoamyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N-1 -methylpentyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-butyl-N-hexyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-butyl-N-tetrahydrofurylmethyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N- butyl-N-ethoxypropyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N- cyclohexylmethyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-butyl-N-phenethyl amino- 2'-carboxybenzophenone, 2-hydroxy-4-N-phenyl amino-2'-carboxybenzophenone, 2-hydroxy- 4-N-(2-methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-(3-methylphenyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-(4-methylphenyl) amino-2'- carboxybenzophenone, 2-hydroxy-4-N-cyclohexyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-pyrrolidinyl amino-2'-carboxybenzophenone, 2-hydroxy-4-N-(2- methylpyrrolidinyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-(3-methylpyrrolidinyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-morpholinyl amino-2'- carboxybenzophenone, 2-hydroxy-4-N-piperidinyl amino-2'-carboxybenzophenone, 2- hydroxy-4-N-(2-methylpiperidinyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-(3- methylpiperidinyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-(4-methylpiperidinyl) amino-2'-carboxybenzophenone, 2-hydroxy-4-N-(4-Dimethylaminophenyl) amino-2'- carboxybenzophenone, 2-hydroxy-3,5-dimethyl-2'-carboxybenzophenone.
Compounds of formula (7) are exemplified by, but not limited to; 3-methoxy toluene, 3- methylphenol, 4-methoxy toluene, 4-methylphenol, 2,4-dimethylanisole, 2,4-dimethylphenol, 4-methoxy-2-methyl diphenylamine, 4-hydroxy-2-methyl diphenylamine, 4-methoxy-2,2',4'- trimethyl diphenylamine, 4-hydroxy-2,2',4'-trimethyl diphenylamine, 2-chloro-5-methoxy toluene, 2-chloro-5-hydroxy toluene, 4-methoxy-2-methyl-3'-trifluoromethyl diphenylamine, 4- hydroxy-2-methyl-3'-trifluoromethyl diphenylamine, 4-methoxy-2-methyl-2'-chloro diphenylamine, 4-hydroxy-2-methyl-2'-chloro diphenylamine, 4-methoxy-2-methyl-4'-chloro diphenylamine, 4-methoxy-2-methyl-2'-fluoro diphenylamine, 4-hydroxy-2-methyl-2'-fluoro diphenylamine, n-octyl-p-anisidine, N-n-octyl-p-aminophenol, 2-dibenzylamino-5-methoxy- toluene, 4-dibenzylamino-3-methylphenol, 4-methoxy-2-chloro diphenylamine, 4-hydroxy-2- chloro diphenylamine, 4-methoxy-2,3'-dimethyl diphenylamine, 4-hydroxy-2,3'-dimethyl diphenylamine, 4-methoxy-2,4'-dimethyl diphenylamine, 4-hydroxy-2,4'-dimethyl diphenylamine, 3-chloroanisole, 3-chlorophenol, 1-napthol, 1-methoxy napthalene, 2-napthol, 2-methoxy napthalene, 4-methoxy-2-ethoxyethyl diphenylamine, 4-hydroxy-2-ethoxyethyl diphenylamine, 4-t-butyl phenol, 4-t-butyl anisole, 4-hydroxybenzoic acid, 4-methoxy benzoic acid, 4-hydroxybenzoic acid ethyl ester, 4-methoxy benzoic acid ethyl ester, 3-(p- dimethylamino)anilinoanisole, 3-(p-dimethylamino)anilinophenol.
Thus the monophase solid solutions can be prepared by reaction between keto acid(s) of formula (6) and compound(s) of formula (7) in the presence of a dehydrating condensation agent, for example, concentrated sulphuric acid, oleum - concentrated sulphuric acid mixtures, polyphosphoric acid, phosphorous pentaoxide or anhydrous aluminium chloride, and mixtures thereof, preferably concentrated sulphuric acid or oleum-concentrated sulphuric acid mixtures, and thereafter bringing the reaction mixture to an alkaline pH in the presence or absence of organic solvent. The solvent, if used, is not specifically limited provided that it is insoluble or only slightly soluble in water. Thus, the solvent may be exemplified by aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzenes, trichlorobenzenes or bromonapthalenes, halogenated aliphatic hydrocarbons such as dichloroethane, trichloroethane or tetrachloroethane, aliphatic hydrocarbons such as hexane, heptane, octane or n-decane and alicyclic hydrocarbons such as cyclohexane or methylcyclohexane. In addition to the above there may also be used alcohols such as amyl alcohol, 2-ethylhexanol or octyl alcohol, ethers such as isopropyl ether, or ketones such as cyclohexanone. The solvent may be used singly or as a mixture.
The condensation reaction is generally carried out at from 0 to about 100°C preferably from about 10 to about 60°C for several to 100 hours. When the reaction is carried out in concentrated sulphuric acid or oleum-concentrated sulphuric acid mixtures, the reaction temperature is preferably in the range from 0 to about 50°C. The reaction time depends upon the selected reaction temperature and hence the reaction is conducted for a sufficient time to permit the reaction to go to completion. Completion of reaction is determined using standard analytical techniques, including but not limited to, thin layer chromatography, gas chromatography and liquid chromatography.
After the dehydrating condensation reaction is completed the alkali treatment may be carried out by addition of the reaction mass to a stirred mixture of base, water and organic solvent. Suitable bases include, for example, potassium hydroxide, lithium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, lithium carbonate, ammonia or organic bases such as triethylamine and mixtures thereof. The preferred bases for use in the process are sodium hydroxide and potassium hydroxide. Suitable solvents include toluene, xylene, halogenated aromatic solvents such as chlorobenzene, esters, ketones, alcohols such as 2-ethylhexanol and mixtures thereof. Additional base may be added as required to achieve an alkalinity within the pH range of 9-12. The treatment may be conducted in a temperature of from 0°C to the boiling point of the solvent or solvent mixture in use, preferably 50 -100°C. During this process, the monophase solid solution according to the present invention may be precipitated from the reaction media. The crystalline precipitate may then be isolated by filtration from the reaction liquors.
After isolation, the monophase solid solution may be washed as desired with water and/or an organic solvent. The solvent may be exemplified by aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzenes, trichlorobenzenes or bromonapthalenes, halogenated aliphatic hydrocarbons such as dichloroethane, trichloroethane or tetrachloroethane, aliphatic hydrocarbons such as hexane, heptane, octane or n-decane and alicyclic hydrocarbons such as cyclohexane or methylcyclohexane. In addition to the above there may also be used alcohols such as methanol, ethanol, isopropanol, butanol, amyl alcohol, 2- ethylhexanol or octyl alcohol, ethers such as isopropyl ether, or ketones such as cyclohexanone. The solvent may be used singly or as a mixture.
Alternatively, after the dehydrating condensation, the reaction mass may be quenched into a stirred water-solvent mixture at from 0 to about 100°C, preferably 60-90°C. The solvent used is not specifically limited provided that it is insoluble or only slightly soluble in water. Thus, the solvent may be exemplified by aromatic hydrocarbons such as benzene, toluene, xylenes or trimethyl benzenes, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzenes, trichlorobenzenes or bromonapthalenes, halogenated aliphatic hydrocarbons such as dichloroethane, trichloroethane or tetrachloroethane, aliphatic hydrocarbons such as hexane, heptane, octane or n-decane and alicyclic hydrocarbons such as cyclohexane or methylcyclohexane. In addition to the above there may also be used alcohols such as amyl alcohol, 2-ethylhexanol or octyl alcohol, ethers such as isopropyl ether, or ketones such as cyclohexanone. The solvent may be used singly or as a mixture. Sufficient base, for example potassium hydroxide, lithium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, lithium carbonate, ammonia or organic bases such as triethylamine and mixtures thereof, is then added to provide an organic-aqueous phase separation. The aqueous layer may then be separated if desired. To the organic phase or biphasic mixture, containing the phthalide intermediate, is then added further base, as described hereinbefore, to pH>10. The reaction mass is stirred at from 0 to about 100°C, preferably 60-90°C, in order to complete cyclisation to the fluoran product. The reaction mass is then adjusted to 25°C and the precipitated crystalline product may then be isolated by filtration as discussed hereinbefore. The reaction product is isolated by filtration from the reaction liquors as the crystal of the invention. After isolation, the crystal may be washed with water and/or an organic solvent as defined previously. In this manner is isolated the monophase solid solution.
This recrystallised crystalline product may then be dried by a usual method, such as at a raised temperature, below the melting point of the crystal, under vacuum, to obtain the monophase solid solutions. The composition of the monophase solid solution obtained is dependant upon the relative amounts of starting materials used.
A third method of preparation is to prepare a mixed keto acid intermediate of general formula (6) from the reaction of aminophenols of general formula (8) with phthalic anhydrides of general formula (9). Wherein R,, R2 and R5 are as hereinbefore detailed.
Figure imgf000023_0001
For instance, a mixed keto acid intermediate consisting of two compounds of general formula (6) may be prepared by reaction of:
i.Two different amino phenols of general formula (8) with a single phthalic anhydride derivative of formula (9). ii.Two different phthalic anhydride derivatives if formula (9) with a single amino phenol of general formula (8).
Amino phenols of formula (8) are exemplified by, but not limited to: N,N-dimethyl aminophenol, N,N-diethyl aminophenol, N,N-di-n-propyl aminophenol, N,N-di- n-butyl aminophenol, N,N-di-n-pentyl aminophenol, N,N-di-n-hexyl aminophenol, N,N- diisopropyl aminophenol, N,N-disecbutyl aminophenol, N,N-diisobutyl aminophenol, N,N- diisoamyl aminophenol, N-methyl-N-cyclohexyl aminophenol, N-methyl-N-phenyl aminophenol, N-methyl-N-(2-methylphenyl) aminophenol, N-methyl-N-(3-methylphenyl) aminophenol, N-methyl-N-(4-methylphenyl) aminophenol, N-methyl-N-propyl aminophenol, N-methyl-N-isopropyl aminophenol, N-methyl-N-butyl aminophenol, N-methyl-N-isobutyl aminophenol, N-methyl-N-secbutyl aminophenol, N-methyl-N-pentyl aminophenol, N-methyl- N-1 -methylbutyl aminophenol, N-methyl-N-isoamyl phenol, N-methyl-N-1 -methylpentyl aminophenol, N-methyl-N-hexyi aminophenol, N-methyl-N-tetrahydrofurylmethyl aminophenol, N-methyl-N-ethoxypropyl aminophenol, N-methyl-N-cyclohexylmethyl aminophenol, N-methyl-N-phenethyl aminophenol, N-ethyl-N-cyclohexyl aminophenol, N- ethyl-N-phenyl aminophenol, N-ethyl-N-(2-methylphenyl) aminophenol, N-ethyl-N-(3- methylphenyl) aminophenol, N-ethyl-N-(4-methylphenyl) aminophenol, N-ethyl-N-propyl aminophenol, N-ethyl-N-isopropyl aminophenol, N-ethyl-N-butyl aminophenol, N-ethyl-N- isobutyl aminophenol, N-ethyl-N-secbutyl aminophenol, N-ethyl-N-pentyl aminophenol, N- ethyl-N-1 -methylbutyl aminophenol, N-ethyl-N-isoamyl phenol, N-ethyl-N-1 -methylpentyl aminophenol, N-ethyl-N-hexyl aminophenol, N-ethyl-N-tetrahydrofurylmethyl aminophenol, N-ethyl-N-ethoxypropyl aminophenol, N-ethyl-N-cyclohexylmethyl aminophenol, N-ethyl-N- phenethyl aminophenol, N-propyl-N-cyclohexyl aminophenol, N-propyl-N-phenyl aminophenol, N-propyl-N-(2-methylphenyl) aminophenol, N-propyl-N-(3-methylphenyl) aminophenol, N-propyl-N-(4-methylphenyl) aminophenol, N-propyl-N-isopropyl aminophenol, N-propyl-N-butyl aminophenol, N-propyl-N-isobutyl aminophenol, N-propyl-N-secbutyl aminophenol, N-propyl-N-pentyl aminophenol, N-propyl-N-1 -methylbutyl aminophenol, N- propyl-N-isoamyl phenol, N-propyl-N-1 -methylpentyl aminophenol, N-propyl-N-hexyl aminophenol, N-propyl-N-tetrahydrofurylmethyl aminophenol, N-propyl-N-ethoxypropyl aminophenol, N-propyl-N-cyclohexylmethyl aminophenol, N-propyl-N-phenethyl aminophenol, N-butyl-N-cyclohexyl aminophenol, N-butyl-N-phenyl aminophenol, N-butyl-N- (2-methyIphenyl) aminophenol, N-butyl-N-(3-methylphenyl) aminophenol, N-butyl-N-(4- methylphenyl) aminophenol, N-butyl-N-propyl aminophenol, N-butyl-N-isopropyl aminophenol, N-butyl-N-isobutyl aminophenol, N-butyl-N-secbutyl aminophenol, N-butyl-N- pentyl aminophenol, N-butyl-N-1 -methylbutyl aminophenol, N-butyl-N-isoamyl phenol, N- butyl-N-1 -methylpentyl aminophenol, N-butyl-N-hexyl aminophenol, N-butyl-N- tetrahydrofurylmethyl aminophenol, N-butyl-N-ethoxypropyl aminophenol, N-butyl-N- cyclohexylmethyl aminophenol, N-butyl-N-phenethyl aminophenol, N-phenyl aminophenol, N- 2-methylphenyl aminophenol, N-3-methylphenyl aminophenol, N-4-methylphenyl aminophenol, N-cyclohexyl aminophenol, 3-N-pyrrolidinyl phenol, 3-N-(2-methylpyrrolidinyl) phenol, 3-N-(3-methylpyrrolidinyl) phenol,3-N-morpholinyl phenol, 3-N-piperidinyl phenol, 3- N-(2-methylpiperidinyl) phenol, 3-N-(3-methylpiperidinyl) phenol, 3-N-(4-methylpiperidinyl) phenol.
Compounds of formula (9) are exemplified by, but not limited to: phthalic anhydride, terephthalic anhydride, 3-methylphthalic anhydride, 3-nitrophthalic anhydride, 3- hydroxyphthalic anhydride, 3-chlorophthalic anhydride, 3-fluorophthalic anhydride, 4- methylphthalic anhydride, 4-t-butylphthalic anhydride, 4-chlorophthalic anhydride, 4- bromophthalic anhydride, 4-fluorophthalic anhydride, 3,6-dichlorophthalic anhydride, 3,6- dimethylphthalic anhydride, 3,6-difluorophthalic anhydride, 4,5-difluorophthalic anhydride, 4,5-dichlorophthalic anhydride, 1 ,2-napthoic anhydride, 2,3-napthoic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, tetraiodophthalic anhydride, tetrafluorophthalic anhydride, tetraphenylphthalic anhydride, tetramethylphthalic anhydride.
For the reaction of the mixtures of m-aminophenol derivatives, as above mentioned, with phthalic anhydrides, the latter is usually used in an amount of 0.5-2.0 moles per total moles of the m-aminophenol derivatives. The ratio of solvent to m-aminophenol derivatives may be between 0 and 20 parts by weight. The quantity of solvent chosen is dependant on the nature of the m-aminophenol derivatives. The amount of solvent used is determined so that the reaction mass remains mobile throughout the course of the reaction. Preferably, the product is precipitated during the reaction. The reaction is effected at an elevated temperature, preferably in the range of 60-120°C for a period of 3-40 hours. The reaction time, solvent ratio and temperature are chosen so as to achieve a suitable balance between length of reaction and the amount of rhodamine type side products that are produced. The amount of rhodamine produced increases at higher temperatures. After the reaction, the reaction mixture is cooled to 0-60°C, most preferably 20-40°C. Dependant on the viscosity of the reaction mixture at this stage, a secondary solvent may be added to the reaction mixture to maintain mobility.
There may be used as the secondary solvent, for example, an aromatic hydrocarbon of 6-10 carbon atoms such as benzene, toluene or xylene, an aliphatic hydrocarbons of 5-12 carbons such as pentane, octane, isooctane, or decane, a halogenated aliphatic, cycloaliphatic or aromatic hydrocarbon of 2-8 carbons, such as perclene, chlorobenzene or dichlorobenzene, ethers such as tetrahydrofuran, dibutyl ether or diphenylether, alcohols such as methanol, ethanol, propanols such as isopropanols or butanols such as n-butanol. There may also be used a mixture of the alcohol with water or a mixture of the alcohol with a hydrocarbon solvent.
The crude keto acid derivative may be recovered from the reaction mixture by filtration, or by diluting the mixture with a solvent in which the derivative is barely soluble and recovering the precipitated derivative by filtration, or by extracting the derivative with an aqueous alkaline solution and precipitating it with acid, or by forming the sodium salt of the derivative, isolating the salt and precipitating it with acid.
The organic solvents when used include, for example, an aromatic hydrocarbon of 6-10 carbon atoms such as benzene, toluene or xylene, an aliphatic hydrocarbon of 8-12 carbons such as octane, isooctane, or decane, a halogenated hydrocarbon of 2-8 carbons, aliphatic, cycloaliphatic or aromatic, such as perclene, chlorobenzene or dichlorobenzene, ethers such as tetrahydrofuran, dibutyl ether or diphenylether, among which are especially preferred aromatic hydrocarbons or ethers. The mixture of keto acids of general formula (6) thus isolated can then be reacted with a diphenylamine of general formula (7), as described previously, to produce a monophase solid solution of formula (5). In this instance the composition of the monophase solid solution isolated is determined by the ratio of the amino phenols used.
If desired, the solid solution, suitably isolated by any of the aforementioned methods, may be further purified by precipitation from an organic solvent or from a organic solvent -water mixture, for example, toluene, benzene, xylene, methanol, ethanol, iso-propanol, n-butanol, acetonitrile, dimethylformamide or mixtures of these solvents. The crystal may be dissolved by heating to a temperature range of from room temperature to the boiling point of the chosen solvent, or above it under pressure in an autoclave. After complete dissolution the crystal may be precipitated with stirring or on standing.
All of the methods of preparation as hereinbefore described can be used to produce the monophase solid solutions of two or more fluoran compounds. Whether or not a monophase solid solution has been formed may be judged by powder X-ray diffraction analysis using K-Cuα rays. A powder X-ray diffraction pattern of a monophase solid solution is substantially identical to that of one of the components, the 'host'. In general the 'host' is the compound forming the greater part of the mixture. A monophase solid solution may also demonstrate a different melting point to that of an equivalent physical mixture. However, a change in melting point may also indicate a mixed crystal has been formed, thus melting point should only be considered in conjunction with powder X-ray diffraction when assessing whether or not a monophase solid solution has been formed.
Representative examples of developers which are suitable for use in the heat sensitive recording material include 4,4'-isopropylidene bisphenol, 4,4'-sec-butylidene bisphenol, 4,4'- cyclohexylidene bisphenol, 2,2-bis-(4-hydroxyphenyl)-4-methylpentane, 2,2-dimethyl-3,3- di(4-hydroxyphenyl)butane, 2,2'-dihydroxydiphenyl, 1-phenyl-1 ,1-bis(4- hydroxyphenyl)butane, 4-phenyl-2,2-bis(4-hydroxyphenyl)butane, 1 -phenyl-2,2-bis(4- hydroxyphenyl)butane, 2,2-bis(4'-hydroxy-3'-methylphenyl)-4-methylpentane, 2,2-bis(4'- hydroxy-3'-tert-butyllphenyl)-4-methylpentane, 4,4'-sec-butylidene-bis (2-methylphenol), 4,4'- isopropylidene-bis (2-tert-butylphenol), 2,2-bis(4'-hydroxy-3'-isopropylphenyl)-4- methylpentane, allyl-4,4-bis (4'-hydroxyphenyl) pentanoate, propargyl-4,4-bis(4'- hydroxyphenyl) pentanoate, n-propyl-4,4-bis (4'-hydroxyphenyl) pentanoate, 2,4-bis (phenylsulfonyl) phenol, 2-(4-methylsulfonyl)-4-(phenylsulfonyl) phenol, 2-(phenylsulfonyl)-4- (4-methyIsulfonyl) phenol, 2,4-bis (4-methylphenylsulfonyl) phenol, pentamethylene-bis(4- hydroxybenzoate), 2,2-dimethyl-3,3-di(4-hydroxyphenyl)pentane, 2,2-di(4- hydroxyphenyl)hexane, 4,4'-dihydroxydiphenyl thioether, 1 ,7-di(4-hydroxyphenylthio)-3,5- dioxaheptane, 2,2'-bis(4-hydroxyphenylthio)diethyl ether, 4,4'-dihydroxy-3,3'-dimethylphenyl thioether; benzyl-4-hydroxybenzoate, ethyl-4-hydroxybenzoate, propyl-4-hydroxybenzoate, isopropyl-4-hydroxybenzoate, butyl-4-hydroxybenzoate, isobutyl-4-hydroxybenzoate, 4,4'- dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxy-4'-butoxydiphenyl sulfone, 4,4'- dihydroxy-3,3'-diallyldiphenyl sulfone, 3,4-dihydroxy-4'-methyldiphenyl sulfone, 4,4'- dihydroxy-3,3',5,5'-tetrabromodiphenyl sulfone, 4,4'-bis (p- toluenesulphonylaminocarbonylamino) diphenylmethane, N-p-toluenesulphonyl-N'-phenyl urea, dimethyl 4-hydroxyphthalate, dicyclohexyl 4-hydroxyphthalate, diphenyl 4- hydroxyphthalate, 4-[2-(4-methoxyphenyloxy)ethyloxy] salicylate, 3,5-di-tert-butylsalicylic acid, 3-benzyl salicylic acid, 3-(α-methylbenzyl) salicylic acid, 3-phenyl-5-(α,α- dimethylbenzyl) salicylic acid, 3,5-di-α-methylbenzyl salicylic acid; metal salts of salicylic acid, 2-benzylsulfonylbenzoic acid, 3-cyclohexyl-4-hydroxybenzoic acid, zinc benzoate, zinc 4-nitrobenzoate, 4-(4'-phenoxybutoxy)phthalic acid, 4-(2'-phenoxyethoxy)phthalic acid, 4-(3'- phenylpropyloxy)phthalic acid, mono (2-hydroxyethyl) -5-nitro-isophthalic acid, 5- benzyloxycarbonyl isophthalic acid, 5-(1 '-phenylethanesulfonyl) isophthalic acid, bis(1 ,2- dihydro-1,5-dimethyI-2-phenyl-3H-pyrazol-3-one-O)bis(thiocyanato-N) zinc and mixtures thereof.
Preferred developers are 4,4'-cyclohexylidene bisphenol, 4,4'-isopropylidene bisphenol, 2,2- bis-(4-hydroxyphenyl)-4-methylpentane, 2,2-dimethyl-3,3-di(4-hydroxyphenyl)butane, 1 - phenyl-1 ,1-bis(4-hydroxyphenyl)butane, 4-phenyl-2,2-bis(4-hydroxyphenyl)butane, 1-phenyl- 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4'-hydroxy-3'-methylphenyl)-4-methylpentane, 2,2- bis(4'-hydroxy-3'-tert-butyllphenyl)-4-methylpentane, 4,4'-sec-butylidene-bis (2- methylphenol), 4,4'-isopropylidene-bis (2-tert-butylphenol), 2,2-bis(4'-hydroxy-3'- isopropylphenyl)-4-methylpentane, allyl-4,4-bis (4'-hydroxyphenyl) pentanoate, propargyl- 4,4-bis(4'-hydroxyphenyl) pentanoate, n-propyl-4,4-bis (4'-hydroxyphenyl) pentanoate, 2,4- bis (phenylsulfonyl) phenol, 2-(4-methylsulfonyl)-4-(phenylsulfonyl) phenol, 2- (phenylsulfonyl)-4-(4-methylsulfonyl) phenol, 2,4-bis (4-methylphenylsulfonyl) phenol, pentamethylene-bis(4-hydroxybenzoate), 2,2-dimethyl-3,3-di(4-hydroxyphenyl)pentane, 2,2- di(4-hydroxyphenyl)hexane, 4,4'-dihydroxydiphenyl thioether, 1 ,7-di(4-hydroxyphenylthio)- 3,5-dioxaheptane, 2,2'-bis(4-hydroxyphenylthio)diethyl ether, 4,4'-dihydroxy-3,3'- dimethylphenyl thioether, ethyl-4-hydroxybenzoate, propyl-4-hydroxybenzoate, isopropyl-4- hydroxybenzoate, butyl-4-hydroxybenzoate, isobutyl-4-hydroxybenzoate, 4,4'- dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxy-4'-butoxydiphenyl sulfone, 4,4'- dihydroxy-3,3'-diallyldiphenyl sulfone, 3,4-dihydroxy-4'-methyldiphenyl sulfone, 4,4'- dihydroxy-3,3',5,5'-tetrabromodiphenyl sulfone, 4,4'-bis(p- toluenesulphonylaminocarbonylamino) diphenylmethane, N-p-toluenesulphonyl-N'-phenyl urea, dimethyl 4-hydroxyphthalate, dicyclohexyl 4-hydroxyphthalate, diphenyl 4- hydroxyphthalate, 4-[2-(4-methoxyphenyloxy)ethyloxy] salicylate, 3,5-di-tert-butylsalicylic acid, 3-benzyl salicylic acid, 3-(α-methylbenzyl) salicylic acid, 3-phenyl-5-(α,α- dimethylbenzyl) salicylic acid, 3,5-di-α-methylbenzyl salicylic acid; zinc salicylate, 2- benzylsulfonylbenzoic acid, 3-cyclohexyl-4-hydroxybenzoic acid, zinc benzoate, zinc 4- nitrobenzoate, 4-(4'-phenoxybutoxy)phthalic acid, 4-(2'-phenoxyethoxy)phthalic acid, 4-(3'- phenylpropyloxy)phthalic acid, mono (2-hydroxyethyl)-5-nitro-isophthalic acid, 5- benzyloxycarbonyl isophthalic acid, 5-(1 '-phenylethanesulfonyl) isophthalic acid, bis(1 ,2- dihydro-1 ,5-dimethyl-2-phenyl-3H-pyrazol-3-one-0)bis(thiocyanato-N) zinc and mixtures thereof.
Highly preferred developers are 4,4'-isopropylidene bisphenol, 2,2-bis-(4-hydroxyphenyl)-4- methylpentane, 2,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-diallyldiphenyl sulfone, 4,4'-bis (p-toluenesulphonylaminocarbonylamino) diphenylmethane, N-p-toluenesulphonyl-N'-phenyl urea and bis(1 ,2-dihydro-1 ,5-dimethyl-2- phenyl-3H-pyrazol-3-one-O)bis(thiocyanato-N) zinc and mixtures thereof.
In addition, the heat sensitive recording material of the invention can contain a stabiliser.
Representative stabilisers for use in heat sensitive recording materials include 2,2'- methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-methylene-bis(4-ethyl-6-tert-butylphenol), 4,4'-butylidene-bis(3-methyl-6-tert-butylphenol), 4,4'-thio-bis(2-tert-butyl-5-methylphenol), 1 ,1 ,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1 ,1 ,3-tris(2-methyl-4-hydroxy-5- cyclohexylphenyl) butane, bis (3-tert-butyl-4-hydroxy-6-methylphenyl) sulfone, bis (3,5- dibromo-4-hydroxyphenyl) sulfone, 4,4'-sulfinyl bis (2-tert-butyl-5-methylphenol), 2,2'- methylene bis (4,6-di-tert-butylphenyl) phosphate and alkali metal, ammonium and polyvalent metal salts thereof, 4-benzyloxy-4'-(2-methylglycidyloxy) diphenyl sulfone, 4,4'- diglycidyloxydiphenyl sulfone, 1 ,4-diglycidyloxybenzene, 4-[α-(hydroxymethyl)benzyloxy]-4- hydroxydiphenyl sulfone, metal salts of p-nitrobenzoic acid, metal salts of phthalic acid mono benzyl ester, metal salts of cinnamic acid and mixtures thereof.
Preferred stabilisers are 4,4'-butylidene-bis(3-methyl-6-tert-butylphenol), 4,4'-thio-bis(2-tert- butyl-5-methylphenol), 1 ,1 ,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1 ,1,3-tris(2- methyl-4-hydroxy-5-cyclohexylphenyl) butane, 4-benzyloxy-4'-(2-methylglycidyloxy) diphenyl sulfone and mixtures thereof.
The heat sensitive recording material of the invention can be prepared according to conventional methods. For example, at least one colour forming compound, at least one developer and at least one sensitiser are pulverised separately in water or a suitable dispersing medium, such as aqueous polyvinyl alcohol, to form an aqueous or other dispersion. If desired a stabiliser is treated in the same manner. The fine particle dispersions thus obtained are combined and then mixed with conventional amounts of binder, filler and lubricant.
Representative binders used for the heat sensitive recording material includes polyvinyl alcohol (fully and partially hydrolysed), carboxy, amide, sulfonic and butyral modified polyvinyl alcohols, derivatives of cellulose such as hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, carboxymethyl cellulose and acetyl cellulose, copolymer of styrene-maleic anhydride, copolymer of styrene-butadiene, polyvinyl chloride, polyvinyl acetate, polyacrylamide, polyamide resin and mixtures thereof.
Exemplary fillers which can be used include calcium carbonate, kaolin, calcined kaolin, aluminium hydroxide, talc, titanium dioxide, zinc oxide, silica, polystyrene resin, urea- formaldehyde resin, hollow plastic pigment and mixtures thereof.
Representative lubricants for use in heat sensitive recording materials include dispersions or emulsions of stearamide, methylene bisstearamide, polyethylene, carnauba wax, paraffin wax, zinc stearate or calcium stearate and mixtures thereof. Other additives can also be employed, if necessary. Such additives are for example fluorescent whitening agents and ultraviolet absorbers.
The coating liquid so obtained can be applied to a suitable substrate such as paper, plastic sheet and resin coated paper, and used as the heat sensitive recording material. The system of the invention can be employed for other end use applications using colour forming materials, for example, a temperature indicating material.
The quantity of the coating is usually 2 to 10 g/m2.
The recording material containing such a thermosensitive colouring layer can in addition contain a protective layer and, if desired, an undercoat layer. The undercoat layer may be interposed between the substrate and the thermosensitive colouring layer.
The protective layer usually comprises a water-soluble resin in order to protect the thermosensitive colouring layer. If desired, the protective layer may contain water-soluble resins in combination with water-insoluble resins.
As such resins conventional resins can be employed. Specific examples are: polyvinyl alcohol; starch and starch derivatives; cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose and ethylcellulose; sodium polyacrylate; polyvinyl pyrrolidone; polyacrylamide/acrylic acid ester copolymers; acrylamide/acrylic acid ester/methacrylic acid copolymers; alkali metal salts of styrene/maleic anhydride copolymers; alkali metal salts of isobutylene/maleic anhydride copolymers; polyacrylamide; sodium alginate; gelatin; casein; water-soluble polyesters and carboxyl-group-modified polyvinyl alcohols.
The protective layer may also contain a water-resisting agent such as a polyamide resin, melamine resin, formaldehyde, glyoxal or chromium alum. Typical amounts of water-resisting agents in the protective layer are 0.2 to 1.0 part by weight.
Furthermore, the protective layer may contain fillers, such as finely-divided inorganic powders, e.g. of calcium carbonate, silica, zinc oxide, titanium oxide, aluminium hydroxide, zinc hydroxide, barium sulphate, clay, talc, surface-treated calcium or silica, or a finely- divided organic powder of, e.g., a urea-formaldehyde resin, a styrene/ methacrylic acid copolymer or polystyrene.
The undercoat layer usually contains as its main components a binder resin and a filler.
Specific examples of binder resins for use in the undercoat layer are: polyvinyl alcohol; starch and starch derivatives; cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose and ethylcellulose; sodium polyacrylate; polyvinyl pyrrolidone; polyacrylamide/acrylic acid ester copolymers; acrylamide/acrylic acid ester/methacrylic acid copolymers; alkali metal salts of styrene/maleic anhydride copolymers; alkali metal salts of isobutylene/maleic anhydride copolymers; polyacrylamide; sodium alginate; gelatin; casein; water-soluble polymers such as water-soluble polyesters and carboxyl-group-modified polyvinyl alcohols; polyvinyl acetate; polyurethanes; styrene/butadiene copolymers; polyacrylic acid; polyacrylic acid esters; vinyl chloride/vinyl acetate copolymers; polybutylmethacrylate; ethylen/vinylacetate copolymers and styrene/butadiene acrylic derivative copolymers.
Specific examples of fillers for use in the undercoat layer are: finely-divided inorganic powders, e.g. of calcium carbonate, silica, zinc oxide, titanium oxide, aluminium hydroxide, zinc hydroxide, barium sulphate, clay, talc, surface-treated calcium or silica, and finely-divided organic powders of, e.g., urea-formaldehyde resins, styrene/methacrylic acid copolymers and polystyrene.
In addition, the undercoat layer may contain a water-resisting agent. Examples of such agents are given above.
The following non-limiting examples, illustrate the novel materials of the present invention.
Preparation example 1
Preparation of a monophase solid solution from 2'-carboxy-4-dibutylamino-2- hydroxybenzophenone (90mol%) and 2'-carboxy-4-diethylamino-2-hydroxybenzophenone
(10mol%). To 249.5g of 98% sulphuric acid and 61.2g oleum was added, 78.97g of 2'-carboxy-4- dibutylamino-2-hydroxybenzophenone and 7.44g of 2'-carboxy-4-diethylamino-2- hydroxybenzophenone over about 2hr with the temperature being maintained below about 25°C by use of an ice-bath. Once in solution, 50.7g of 4-methoxy-2-methyldiphenylamine was added and the mixture was stirred for about 3hr at 30°C. The reaction mass was then added, over about 30 minutes with stirring, to a mixture of 135g toluene-45g water at 85°C. To this was then added, over 30 minutes, 135.7g water. Agitation was ceased and the separated aqueous phase was removed. To the remaining organic phase was added 244g sodium hydroxide 100°TW, 199g toluene and 387g water and the reaction was stirred for 2h at 85°C. The reaction was cooled to 25°C and the precipitated product was isolated by filtration. The product was washed with hot water (about 60°C) then methanol and dried to yield 106.2g of a monophase solid solution (melting point 179.9-181.4°C).
Example 1
Preparation of heat sensitive coating formulations containing 3-dibuty!amino-6-methyl-7- anilinofluoran.
Dispersions A to C were prepared by grinding the compositions shown below in an attritor until an average particle size of 1 -1.5μ was attained.
Dispersion A (Colour Former) 3-dibutylamino-6-methyl-7-anilinofluoran 3.01 parts Polyvinyl alcohol (10% aqueous solution) 10.50 parts Water 6.49 parts
Dispersion B (Colour Developer)
4,4'-isopropylidene bisphenol 7.5 parts
Polyvinyl alcohol (10% aqueous solution) 7.5 parts
Water 22.5 parts
Dispersion C (Sensitiser)
1 ,4-diproprionyloxybenzene 10.0 parts
Polyvinyl alcohol (10% aqueous solution) 10.0 parts Water 20.0 parts
A thermal coating mixture was then prepared by combining together the following components: parts by weight Dispersion A 6.6
Dispersion B 10.0
Dispersion C 6.0
Calcium Carbonate (25% aqueous dispersion) 12.0 Zinc stearate (33% aqueous dispersion) 0.9
Polyvinyl alcohol (10% aqueous solution) 4.5
Tinopal® ABP-X (fluorescent whitening agent) 0.12 Water 2.48
This coating mixture was applied on one side of a base paper weighing 50 g/m2 in a coating weight of about 5.0 g/m2 and then dried. The resulting sheet was calendered by means of a laboratory calender to produce a recording sheet with excellent background whiteness.
The heat sensitive recording paper obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water. Additionally, the recording paper obtained shows a high dynamic sensitivity.
Evaluation of water resistance was conducted by immersing a facsimile image in de-ionised water for 24 hours at room temperature and then observing the remaining image density. Evaluation of sensitivity was done using an Infotec fax machine 3301 at pulse widths of 0.30, 0.50, 0.68 and 1.00 milliseconds.
Evaluation of post application was conducted by observing the whiteness of the paper. Evaluation of light resistance was conducted by inspecting the degree of yellowing of the uncoloured portion of the paper after exposure to 120 hours of artificial daylight. Evaluation of heat and moisture resistance was conducted by examining the soiling of the uncoloured portion of paper after storage at 60°C and 50% relative humidity for one hour Example 2
Preparation of heat sensitive coating formulations containing 3-(N-ethyl-N-isoamylamino)-6- methyl-7-anilinofluoran.
A heat sensitive recording material was prepared by the method described in example 1 with 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran being used as the colour former in place of 3-dibutylamino-6-methyl-7-anilinofluoran.
The heat sensitive recording paper thus obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water.
Example 3
Preparation of heat sensitive coating formulations containing a monophase solid solution consisting of 3-dibutylamino-6-methyl-7-anilinofluoran and 3-diethylamino-6-methyl-7- anilinofluoran.
A heat sensitive recording material was prepared by the method described in example 1 with a monophase solid solution of 3-dibutylamino-6-methyl-7-anilinofluoran (9 parts) and 3- diethylamino-6-methyl-7-anilinofluoran (1 part) being used as the colour former in place of 3- dibutylamino-6-methyl-7-anilinofluoran in dispersion A. As sensitiser a mixture of 90 parts 1 ,4-diproprionyloxybenzene and 10 parts 1 ,4 diacetoxybenzene was used in place of 1,4- diproprionyloxybenzene in dispersion C.
The heat sensitive recording paper thus obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water.
Example 4
Preparation of heat sensitive coating formulations containing 3-dibutylamino-6-methyl-7- anilinofluoran. A heat sensitive recording material was prepared by the method described in example 1 with a mixture of 90 parts 1 ,4-diproprionyloxybenzene and 10 parts 1,4 diacetoxybenzene being used as sensitiser in place of 1 ,4-diproprionyloxybenzene in dispersion C.
The heat sensitive recording paper thus obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water.
Examples 5 to 14
The following Table 1 shows the colour former/developer/sensitiser combinations that were used in each example. The heat sensitive recording material was prepared by the method described in example 1. In all cases, the heat sensitive recording paper thus obtained demonstrates excellent background whiteness of paper after application of the coating liquid and in storage stability, i.e. resistance to light, heat and moisture, of uncoloured portion of the coated paper and excellent resistance of the image to water.
Table 1
Figure imgf000036_0001
Figure imgf000037_0001

Claims

Claims
1. A heat sensitive recording material, comprising a) at least one colour forming compound selected from the group consisting of 3-diethylamino-6-methyl-7-(3-methylanilino) fluoran, 3-dibutylamino-6-methyl-7- anilinofluoran, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-propylamino)-6- methyl-7-anilinofluoran, 3-(N-ethyl-p-toluidino)-6-methyl-7-anilinofluoran and 3-(N-ethyl- N-isoamylamino)-6-methyl-7-anilinofluoran; or a monophase solid solution comprising at least two colour forming compounds; b) at least one sensitiser of the formula
Figure imgf000038_0001
wherein R and R' are identical or different from each other and each represent CrC6alkyl; and c) at least one developer.
2. A heat sensitive recording material according to claim 1 comprising at least one colour forming compound selected from the group consisting of 3-dibutylamino-6-methyl-7- anilinofluoran, 3-dipentylamino-6-methyl-7-anilinofluoran and 3-(N-ethyl-N-isoamylamino)-6- methyl-7-anilinofluoran.
3. A heat sensitive recording material according to claim 1 or 2 comprising at least one colour forming compound selected from the group consisting of 3-dibutylamino-6-methyl-7- anilinofluoran and 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran.
4. A heat sensitive recording material according to any of claims 1 to 3 comprising 3-dibutylamino-6-methyl-7-anilinofluoran as colour forming compound.
5. A heat sensitive recording material according to claim 1 comprising a monophase solid solution comprising at least two colour forming compounds.
6. A heat sensitive recording material according to claim 1 comprising a mixture of 3-diethylamino-6-methyl-7-anilino fluoran and 3-dibutylamino-6-methyl-7- anilinofluoran, or a mixture of 3-(N-ethyl-N-isoamylamino)-6-methyl-7-anilinofluoran and 3-dibutylamino-6- methyl-7-anilinofluoran, or a mixture of 3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofluoran and 3-dibutylamino-6- methyl-7-anilinofluoran.
7. A heat sensitive recording material according to any of claims 1 to 6 comprising at least one sensitiser of the formula
Figure imgf000039_0001
wherein R and R' are as defined in claim 1.
8. A heat sensitive recording material according to any of claims 1 to 7 wherein R and R' are identical or different from each other and each represent d-C4aikyl.
9. A heat sensitive recording material according to any of claims 1 to 8 wherein R and R' independently from one another are methyl or ethyl, preferably ethyl.
10. A heat sensitive recording material according to any of claims 1 to 9 wherein R and R' are identical.
11. A heat sensitive recording material according to any of claims 1 to 6 comprising a sensitiser of the formula
Figure imgf000040_0001
12. A heat sensitive recording material according to any of claims 1 to 6 comprising a sensitiser of the formula
Figure imgf000040_0002
13. A heat sensitive recording material according to any of claims 1 to 6 comprising a sensitiser of the formula
Figure imgf000040_0003
together with a sensitiser of the formula
Figure imgf000041_0001
14. A heat sensitive recording material according to claim 11 comprising a sensitiser of the formula (3) and 6-dibutylamino-3-methyl-2-anilinofluoran as colour forming compound.
15. A heat sensitive recording material according to any of claims 1 to 14 comprising at least one developer selected from the group consisting of
4,4'-isopropylidene bisphenol, 4,4'-sec-butylidene bisphenol, 4,4'-cyclohexylidene bisphenol, 2,2-bis-(4-hydroxyphenyl)-4-methylpentane, 2,2-dimethyl-3,3-di(4-hydroxyphenyl)butane, 2,2'-dihydroxydiphenyl, 1-phenyl-1 ,1-bis(4-hydroxyphenyl)butane, 4-phenyl-2,2-bis(4- hydroxyphenyl)butane, 1 -phenyl-2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4'-hydroxy-3'- methylphenyl)-4-methylpentane, 2,2-bis(4'-hydroxy-3'-tert-butyllphenyl)-4-methylpentane, 4,4'-sec-butylidene-bis (2-methylphenol), 4,4'-isopropylidene-bis (2-tert-butylphenol), 2,2- bis(4'-hydroxy-3'-isopropylphenyl)-4-methylpentane, allyl-4,4-bis (4'-hydroxyphenyl) pentanoate, propargyl-4,4-bis(4'-hydroxyphenyl) pentanoate, n-propyl-4,4-bis (4'- hydroxyphenyl) pentanoate, 2,4-bis (phenylsulfonyl) phenol, 2-(4-methylsulfonyl)-4- (phenylsulfonyl) phenol, 2-(phenylsulfonyl)-4-(4-methylsulfonyl) phenol, 2,4-bis (4- methylphenylsulfonyl) phenol, pentamethylene-bis(4-hydroxybenzoate), 2,2-dimethyl-3,3- di(4-hydroxyphenyl)pentane, 2,2-di(4-hydroxyphenyl)hexane, 4,4'-dihydroxydiphenyl thioether, 1 ,7-di(4-hydroxyphenylthio)-3,5-dioxaheptane, 2,2'-bis(4-hydroxyphenylthio)diethyl ether, 4,4'-dihydroxy-3,3'-dimethylphenyl thioether; benzyl-4-hydroxybenzoate, ethyl-4- hydroxybenzoate, propyl-4-hydroxybenzoate, isopropyl-4-hydroxybenzoate, butyl-4- hydroxybenzoate, isobutyl-4-hydroxybenzoate, 4,4'-dihydroxydiphenyl sulfone, 2,4'- dihydroxydiphenyl sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 4-hydroxy-4'- isopropoxydiphenyl sulfone, 4-hydroxy-4'-butoxydiphenyl sulfone, 4,4'-dihydroxy-3,3'- diallyldiphenyl sulfone, 3,4-dihydroxy-4'-methyldiphenyl sulfone, 4,4'-dihydroxy-3,3',5,5'- tetrabromodiphenyl sulfone, 4,4'-bis (p-toluenesulphonylaminocarbonylamino) diphenylmethane, N-p-toluenesulphonyl-N'-phenyl urea, dimethyl 4-hydroxyphthalate, dicyclohexyl 4-hydroxyphthalate, diphenyl 4-hydroxyphthalate, 4-[2-(4- methoxyphenyloxy)ethyloxy] salicylate, 3,5-di-tert-butylsalicylic acid, 3-benzyl salicylic acid, 3-(α-methylbenzyl) salicylic acid, 3-phenyl-5-(α,α-dimethylbenzyl) salicylic acid, 3,5-di-α- methylbenzyl salicylic acid; metal salts of salicylic acid, 2-benzylsulfonylbenzoic acid, 3- cyclohexyl-4-hydroxybenzoic acid, zinc benzoate, zinc 4-nitrobenzoate, 4-(4'- phenoxybutoxy)phthalic acid, 4-(2'-phenoxyethoxy)phthalic acid, 4-(3'- phenylpropyloxy)phthalic acid, mono (2-hydroxyethyl) -5-nitro-isophthaIic acid, 5- benzyloxycarbonyl isophthalic acid, 5-(1'-phenylethanesulfonyl) isophthalic acid and bis(1 ,2- dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one-O)bis(thiocyanato-N) zinc.
16. A heat sensitive recording material according to any of claims 1 to 14 comprising at least one developer selected from the group consisting of 4,4'-isopropylidene bisphenol, 2,2- bis-(4-hydroxyphenyl)-4-methylpentane, 2,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'- isopropoxydiphenyl sulfone, 4,4'-dihydroxy-3,3'-diallyldiphenyl sulfone, 4,4'-bis (p- toluenesulphonylaminocarbonylamino) diphenylmethane, N-p-toluenesulphonyl-N'-phenyl urea and bis(1 ,2-dihydro-1 ,5-dimethyl-2-phenyl-3H-pyrazol-3-one-O)bis(thiocyanato-N) zinc and mixtures thereof.
17. A heat sensitive recording material according to any of claims 1 to 16 comprising at least one stabiliser.
18. A heat sensitive recording material according to any of claims 1 to 17 comprising at least one stabiliser selected from the group consisting of
4,4'-butylidene-bis(3-methyl-6-tert-butylphenol), 4,4'-thio-bis(2-tert-butyl-5-methylphenol), 1 ,1 ,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1 ,1 ,3-tris(2-methyl-4-hydroxy-5- cyclohexylphenyl) butane and 4-benzyloxy-4'-(2-methylglycidyloxy) diphenyl sulfone.
PCT/EP1999/007895 1998-10-30 1999-10-19 Heat sensitive recording material WO2000026037A1 (en)

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GBGB9823753.0A GB9823753D0 (en) 1998-10-30 1998-10-30 Heat sensitive recording material
GB9823753.0 1998-10-30
GBGB9827566.2A GB9827566D0 (en) 1998-12-16 1998-12-16 Heat sensitive recording material
GB9827566.2 1998-12-16

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WO2000026037A1 true WO2000026037A1 (en) 2000-05-11

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PCT/EP1999/007895 WO2000026037A1 (en) 1998-10-30 1999-10-19 Heat sensitive recording material

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WO (1) WO2000026037A1 (en)

Cited By (3)

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Publication number Priority date Publication date Assignee Title
US6217643B1 (en) 1999-02-16 2001-04-17 Esco Company Color former composition and microcapsules containing the composition
WO2003037846A1 (en) * 2001-10-26 2003-05-08 Ciba Specialty Chemicals Holding Inc. Production of keto acids
WO2015181291A1 (en) 2014-05-28 2015-12-03 Papierfabrik August Köhler Se Heat-sensitive recording material

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57133097A (en) * 1981-02-13 1982-08-17 Mita Ind Co Ltd Heat sensitive recording body and manufacture thereof
JPS5859098A (en) * 1981-10-05 1983-04-07 Fuji Photo Film Co Ltd Heat-sensitive recording material
EP0589427A2 (en) * 1992-09-22 1994-03-30 Dainippon Ink And Chemicals, Inc. Thermosensitive recording medium
JPH10138645A (en) * 1996-11-14 1998-05-26 Nippon Steel Chem Co Ltd Thermal recording material

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57133097A (en) * 1981-02-13 1982-08-17 Mita Ind Co Ltd Heat sensitive recording body and manufacture thereof
JPS5859098A (en) * 1981-10-05 1983-04-07 Fuji Photo Film Co Ltd Heat-sensitive recording material
EP0589427A2 (en) * 1992-09-22 1994-03-30 Dainippon Ink And Chemicals, Inc. Thermosensitive recording medium
JPH10138645A (en) * 1996-11-14 1998-05-26 Nippon Steel Chem Co Ltd Thermal recording material

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* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 006, no. 232 (M - 172) 18 November 1982 (1982-11-18) *
PATENT ABSTRACTS OF JAPAN vol. 007, no. 149 (M - 225) 30 June 1983 (1983-06-30) *
PATENT ABSTRACTS OF JAPAN vol. 1998, no. 10 31 August 1998 (1998-08-31) *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6217643B1 (en) 1999-02-16 2001-04-17 Esco Company Color former composition and microcapsules containing the composition
WO2003037846A1 (en) * 2001-10-26 2003-05-08 Ciba Specialty Chemicals Holding Inc. Production of keto acids
WO2015181291A1 (en) 2014-05-28 2015-12-03 Papierfabrik August Köhler Se Heat-sensitive recording material
US10160245B2 (en) 2014-05-28 2018-12-25 Papierfabrik August Kohler Se Heat-sensitive recording material

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