DE4114456A1 - New N-amino pyridone dyestuff cpds. - used in transfer to plastics-coated paper by diffusion or sublimation and for dyeing polyamide, polyester, etc. - Google Patents

Abstract

New 4-alkyl-N-amino-3-cyano-5-(het)arylimino- or -5-(het)arylmethylene-pyrid-2,6-dione dyestuffs (I) are of the formula (I) where R1 is 1-4C alkyl; R2 is H, pyridylcarbonyl, 5-7C cyclohexyl or an opt. substd. 1-12C alkyl, phenyl, pyridyl, 1-12C alkanoyl, 1-12 C alkoxycarbonyl, 1-12 C alkylsulphonyl, phenylsulphonyl, pyridylsulphonyl or benzoyl gp.; X is CH or N; R3 is an aromatic carbocyclic or heterocyclic gp. (I) can be prepd. (not claimed) by standard methods, e.g. as described in the text and examples (see below). USE/ADVANTAGE - (I) are claimed for use in diffusion or sublimation transfer from a substrate to plastics-coated paper, using an energy source. They can be transferred to all heat-resistant plastics with an affinity for (I), e.g. modified polycarbonates or polyesters. (I) are also suitable for dyeing synthetic materials, e.g. polyesters, polyamides or polycarbonates. Cf. the dyestuffs normally used in colour transfer printing, (I) have better resistance to migration at room temp., thermal transfer property, thermal and photochemical stability, resistance to moisture and chemicals or solubility, are more readily available, have higher colour strength and purity or a more favourable absorption band for subtractive colour mixing. .

Description

The present invention relates to new pyridone dyes of the formula I.

in the
R¹ C₁-C₄ alkyl,
R² is hydrogen, optionally substituted C₁-C₁₂ alkyl, optionally substituted phenyl, optionally substituted pyridyl, optionally substituted C₁-C₁₂ alkanoyl, C₁-C₁₂ alkoxycarbonyl, optionally substituted C₁-C₁₂ alkylsulfonyl, optionally substituted phenylsulfonyl, optionally substituted pyridylsulfonyl, optionally substituted benzoyl, pyridylcarbonyl or C₅-C₇-cyclohexyl,
X CH or nitrogen and
R₃ is an aromatic carbocyclic or heterocyclic radical
and a method for their thermal transfer.

Pyridone dyes are already known from EP-A-4 16 434. It has however, showed that the prior art dyes still lacked in have their application properties.

The object of the present invention was therefore to develop new N-aminopyridone dyes Provide substances that are advantageous for thermal Transfer.

Accordingly, the pyridone dyes specified in the introduction of Formula I found.

Aromatic carbocyclic or heterocyclic radicals R ^{3 are} derived, for example, from the aniline, aminonaphthalene, indole, quinoline, benzoxazine or aminothiazole series.

Pyridone dyes of the formula I are preferred in which
R² is a radical of the formula

means what
R⁴ for hydrogen, methyl, methoxy, C₁-C₄-alkylsulfonylamino, C₁-C₄- mono- or dialkylaminosulfonylamino or the radical -NHCOR⁹ or -NHCO₂R⁹, where R⁹ is phenyl, benzyl, tolyl or C₁-C₈- alkyl, which optionally is interrupted by one or two oxygen atoms in ether function,
R⁵ represents hydrogen, methyl, methoxy or ethoxy,
R⁶ and R⁷ are the same or different and are each independently hydrogen, C₁-C₈-alkyl, which is optionally substituted and can be interrupted by one or two oxygen atoms in ether function, or C₅-C₇-cycloalkyl and
R⁸ represents hydrogen, halogen, C₁-C₆-alkyl, optionally substituted phenyl, optionally substituted benzyl, cyclohexyl, thienyl, hydroxy or C₁-C₈-monoalkylamino and
R¹ has the meaning given above.

All that occur in the formula of the pyridone dyes according to the invention Alkyl groups can be either straight-chain or branched.

If substituted alkyl groups occur in the formula of the pyridone dyes according to the invention, z. B. cyano, phenyl, tolyl, C ₁ -C ₆ alkanoyloxy, C ₁ -C ₄ alkoxycarbonyl or C ₁ -C ₄ alkoxycarbonyl oxy, in the latter case the alkoxy group being substituted by phenyl or C ₁ -C ₄ alkoxy can be considered.

If substituted phenyl or pyridyl groups occur in the formula of the pyridone dyes according to the invention, substituents such as. B. C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy come into consideration.

R¹, R², R⁶, R⁷, R⁸ and R⁹ are z. B. methyl, ethyl, propyl, isopropyl, Butyl, isobutyl or sec-butyl.

Suitable radicals R², R⁶, R⁷, R⁸ and R⁹ are also z. B. pentyl, isopentyl, Neopentyl, tert-pentyl, hexyl or 2-methylpentyl.

R², R⁶, R⁷ and R⁹ are still z. B. heptyl, octyl, isooctyl or 2-ethylhexyl.

Residues R² are still z. B. nonyl, isononyl, decyl, isodecyl, undecyl or dodecyl (The above terms isooctyl, isononyl or isodecyl are trivial names and derive from those obtained after oxo synthesis Alcohols - cf. also Ullmann's encyclopedia of technical chemistry, 4th edition, volume 7, pages 215 to 217, and volume 11, pages 435 and 436.), phenyl, 2-, 3- or 4-methylphenyl, 2-, 3- or 4-methoxyphenyl, Pyridyl, 2-, 3- or 4-methylpyridyl, 2-, 3- or 4-methoxypyridyl, Formyl, acetyl, propionyl, butyryl, isobutyryl, pentanoyl, hexanoyl, Heptanoyl, octanoyl, 2-ethylhexanoyl, methoxycarbonyl, ethoxycarbonyl, Propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, methylsulfonyl,  Ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, phenylsulfonyl, Tolylsulfonyl, pyridylsulfonyl, benzoyl or 2-, 3- or 4-methylbenzoyl.

R⁶, R⁷ and R⁹ are still z. B. 2-methoxyphenyl, 2- or 3-methoxypropyl, 2-ethoxyethyl, 2- or 3-ethoxypropyl, 2-propoxyethyl, 2- or 3-propoxypropyl, 2-butoxyethyl, 2- or 3-butoxypropyl, 3,6-dioxaheptyl or 3,6-dioxaoctyl.

R², R⁶ and R⁷ are still z. B. 2-cyanoethyl, 2- or 3-cyanopropyl, 2-acetyloxyethyl, 2- or 3-acetyloxypropyl, 2-isobutyryloxyethyl, 2- or 3-isobutyryloxypropyl, 2-methoxycarbonylethyl, 2- or 3-methoxycarbonylpropyl, 2-ethoxycarbonylethyl, 2- or 3-ethoxycarbonylpropyl, 2-methoxycarbonyloxyethyl, 2- or 3-methoxycarbonyloxypropyl, 2-ethoxycarbonyloxyethyl, 2- or 3-ethoxycarbonyloxypropyl, 2-butoxycarbonyloxyethyl, 2- or 3-butoxycarbonyloxypropyl, 2- (2-phenylethoxycarbonyloxy) ethyl, 2- or 3- (2-phenylethoxycarbonyloxy) propyl, 2- (2-ethoxyethoxycarbonylloxy) ethyl, 2- or 3- (2-ethoxyethoxycarbonyloxy) propyl, benzyl, 2-methylbenzyl, 1- or 2-phenylethyl, cyclopentyl, cyclohexyl or cycloheptyl.

R⁴ are z. B. methylsulfonylamino, ethylsulfonylamino, propylsulfonylamino, Isopropylsulfonylamino, butylsulfonylamino, mono- or dimethylaminosulfonylamino, Mono- or diethylaminosulfonylamino, mono- or Dipropylaminosulfonylamino, mono- or diisopropylaminosulfonylamino, Mono- or dibutylaminosulfonylamino or (N-methyl-N-ethylaminosulfonyl) - amino.

R⁸ are still z. B. phenyl, 2-methylphenyl, 2,4-dimethylphenyl, 2-methoxyphenyl, 2,4-dimethoxyphenyl, benzyl, 2-methylbenzyl, 2,4-dimethylbenzyl, 2-methoxybenzyl, 2,4-dimethoxybenzyl, methylamino, ethylamino, Propylamino, isopropylamino, butylamino, pentylamino, hexylamino, Heptylamino, octylamino or 2-ethylhexylamino.

Dyes of the formula I in which R ^{3 is} a radical of the formula IIa, IIc, IIj or IIn are particularly preferred, a radical of the formula IIa or IIj being particularly mentioned.

Particularly noteworthy are dyes of the formula IIIa

in the
X CH or nitrogen,
L¹ C₁-C₈-alkyl, phenyl, tolyl, C₁-C₈-alkylcarbonyl, C₁-C₈-alkylsulfonyl, phenylsulfonyl, tolylsulfonyl, pyridylsulfonyl, benzoyl, methylbenzoyl or pyridylcarbonyl,
L² is hydrogen, methyl, methoxy or the radical -NHCOR⁹ or -NHCO₂R⁹, where R⁹ is phenyl, benzyl, tolyl or C₁-C₈-alkyl, which is optionally interrupted by one or two oxygen atoms in ether function, and
L³ and L⁴ independently of one another are hydrogen, C₁-C₈-alkyl, 2-cyanoethyl, benzyl, C₁-C₄-alkanoyloxy-C₁-C₄-alkyl, C₁-C₄-alkoxycarbonyl-C₁-C₄- alkyl or C₁-C Alk-alkoxycarbonyloxy-C₁ -C₄-alkyl mean.

Dyes of the formula IIIb are also particularly noteworthy

in the L⁵ C₁-C₆ alkyl, phenyl, tolyl, benzyl, cyclohexyl or thienyl means and X, L¹, L² and L³ each have the meaning given above.

The pyridone dyes of the formula I according to the invention can per se known methods are produced.

For example, one can formyl (X = CH) or nitroso (X = N) Formula IV

R³-X = O (IV),

in which R³ has the meaning given above, with a pyridone Formula V

in which R¹ and R² each have the meaning given above, condense.

It is also possible to use amines of the formula VI

R³-NH₂ (VI),

in which R ^{3 has} the abovementioned meaning to be oxidatively coupled with pyridones of the formula V (see, for example, US Pat. No. 4,695,287).

Another object of the present invention was to develop a new ver drive to provide for the thermal transfer of dyes.

In the thermal transfer printing process, a transfer sheet containing a ther mix transferable dye in one or more binders, ge if necessary, together with suitable aids, on a carrier holds with an energy source, e.g. B. with a heating head or a laser, by short heating impulses (duration: fractions of a second) from the back side heated, causing the dye to migrate from the transfer sheet and diffuse into the surface coating of a recording medium dated. The main advantage of this method is that the Control of the amount of dye to be transferred (and thus the color dev gradation) by setting the energy to be delivered by the energy source is easily possible.

Generally, the color record is made using the three subtractive ones Primary colors yellow, magenta, cyan (and possibly black) carried out.

In order to enable optimal color recording, the dyes have the following properties:

• - easy thermal transferability,
• - low migration within or from the surface coating of the Recording medium at room temperature,  
• - high thermal and photochemical stability and resistance to Moisture and chemical substances,
• - have suitable shades for subtractive color mixing,
• have a high molar absorption coefficient,
• - Do not crystallize out when storing the transfer sheet.

Experience has shown that these requirements are very difficult at the same time fulfill.

Therefore, most correspond to the known ones for thermal transfer printing dyes did not meet the required profile.

It has now been found that the transfer of pyridone dyes from a carrier on a plastic coated paper with the help of a Energy source succeeds advantageously when using a carrier on which is one or more dyes of the above formula I.

Compared to the dyes used in the known processes stand out the dyes transferred in the inventive method of formula I in general by improved migration properties in Recording medium at room temperature, easier thermal transfer speed, higher thermal and photochemical stability, lighter tech niche accessibility, better resistance to moisture and chemical Fabrics, higher color strength, better solubility or better suitability for the subtractive color mixture (higher color purity, cheaper form of Absorption band).

To produce the color required for the process according to the invention The dyes are supported in a suitable organic solution medium or in mixtures of solvents with one or more bin demitteln, if necessary with the addition of auxiliaries, to a pressure color processed. This contains the dye preferably in molecular dispersed solution. The printing ink can be applied to the inert carriers are applied and the color is dried in air.

Suitable organic solvents for the dyes I are e.g. B. such in which the solubility of the dyes I at a temperature of 20 ° C. is greater than 1% by weight, preferably greater than 5% by weight.  

Examples include ethanol, propanol, isobutanol, tetrahydrofuran, Methylene chloride, methyl ethyl ketone, cyclopentanone, cyclohexanone, toluene, Chlorobenzene or mixtures thereof called.

All resins or polymer materials are suitable as binders, which are soluble in organic solvents and the dye on the are able to bind inert carriers in an abrasion-resistant manner. Such a bandage preferred, which the dye after drying the ink on the Absorb air in the form of a clear, transparent film without this a visible crystallization of the dye occurs.

Such binders are, for example, in the older German patent application P 40 04 612.5 or in the corresponding patent cited there called registrations.

Preferred binders are ethyl cellulose, ethyl hydroxyethyl cellulose, Polyvinyl butyrate, polyvinyl acetate or cellulose propionate.

The weight ratio of binder: dye is generally 1: 1 to 10: 1.

As aids come e.g. B. separating agent into consideration, as in the older German patent application P 40 04 612.5 or the corresponding Patent applications cited there are mentioned. In addition, be to mention especially organic additives, which crystallize the Ver transfer dyes during storage or when the ribbon is heated prevent e.g. B. cholesterol or vanillin.

Suitable inert carriers are e.g. B. in the older European patent application 91 101 435.5 or in the corresponding patent cited therein registrations described. The thickness of the dye carrier is in generally 3 to 30 µm, preferably 5 to 10 µm.

In principle, all temperature-stable come as the dye receiver layer Plastic layers with affinity for the dyes to be transferred considered, e.g. B. modified polycarbonates or polyester. Further Details can z. B. from the older European patent application 91 101 435.5 or the corresponding patent applications cited therein be removed.  

The transmission takes place by means of an energy source, e.g. by means of a Laser or a thermal head, the latter to a temperature of 300 ° C must be heatable so that the dye transfer in the time range t: 0 <t <15 ms can take place. The dye migrates from the Transfer sheet and diffuses into the surface coating of the Recording medium.

The dyes according to the invention are also advantageously suitable for Dyeing synthetic materials e.g. B. of polyesters, polyamides or Polycarbonates.

The following examples are intended to explain the invention in more detail.

Manufacture of dyes example 1

13.1 g of 3-acetylamino-N, N-dibutylaniline were in an aqueous hydrochloric acid medium nitrosed with sodium nitrite. After adding 20% by weight ammonia water up to a pH of 8 the compound of formula

taken up in methylene chloride. The organic phase was in the separatory funnel separated and with a solution of 15.5 g of the pyridone

combined in 30 ml acetic anhydride.  

After the methylene chloride had been distilled off, the mixture was briefly heated to 90.degree and then cooled to room temperature. Then 100 ml Iso propanol and 50 ml of methanol are added and the dye is added by adding about 5 ml of water precipitated. After vacuuming and thorough washing with Methanol was spectrally 18.1 g (64% of theory) of the above dye get pure form.

Mp = 170 to 174 ° C
λ _max (tetrahydrofuran): 590 nm
(Methylene chloride): 598 nm.

Example 2

15.5 g of the pyridone described in Example 1 were mixed with 15.1 g 2- (N-butyl-N-ethylamino) -4-phenyl-5-formylthiazole, 0.5 g β-alanine and 2.0 g of p-toluenesulfonic acid in 65 ml of ethyl acetate for 3.5 hours at room temperature stirred. The mixture was then heated to 50 ° C. for 30 minutes. To Cooling to room temperature, the dye was suctioned off with little Methanol and water washed neutral and at 95 ° C under reduced Pressure dried. The yield of spectrally pure product was 17.6 g (63% of theory).

Mp = 141 ° C
λ _max (tetrahydrofuran): 532 nm
(Methylene chloride): 537 nm.

The dyes listed in Tables 1 to 3 below are obtained in an analogous manner. The names mentioned under the substituent R ³ refer to the names of the formulas in the description.

Table 1

Table 2

Table 3

Transfer of the dyes

The quantitative and simple transfer behavior of the dyes To be able to check the thermal transfer with large-area heating jaws carried out, the transfer temperature in the range 50 ° C <T <120 ° C. varied and the transfer time was set to 2 minutes.

α) General recipe for coating the carrier with dye

1 g of binder was in 8 ml of toluene / ethanol (8: 2 v / v) at 40 to 50 ° C solved. A solution of 0.25 g of dye in 5 ml of tetra was added hydrofuran stirred in and possibly of insoluble residue filtered off. The printing paste thus obtained was applied using an 80 μm doctor blade peeled off on a polyester film (thickness: 6 to 10 µm) and with a Dried hair dryer.

β) Testing for thermal transferability

The dyes used were tested in the following way:
The polyester film (donor) containing the dye to be tested in the coating composition (front side) was placed with the front side on commercially available (recipient) and pressed on. The encoder / receiver was then wrapped with aluminum foil and heated between two heated plates at different temperatures T (in the temperature interval 50 ° C <T <120 ° C). The amount of dye diffused into the glossy plastic layer of the receiver is proportional to the optical density (= extinction A). The latter was determined photometrically. If one plots the logarithm of the extinction A of the colored recipient papers measured in the temperature interval between 50 and 120 ° C against the associated reciprocal absolute temperature, straight lines are obtained, from whose slope the activation energy ΔE _{T is} calculated for the transfer experiment:

For complete characterization, the orders were also added the temperature T × [° C] taken at which the absorbance A of stained recipient papers reached the value 1.  

The dyes listed in Table 4 below were processed according to α) and the resulting, dye-coated supports according to β) tested for the transfer behavior. The table shows the thermal transfer parameters T and ΔE _T , respectively.

Hitachi Color Video Print Paper from the Grade VY-S. Vylon® 290 from Toyobo was used as the binder.

Table 4

Claims (3)

1. Pyridone dyes of the formula I. in the
R¹ C₁-C₄ alkyl,
R² is hydrogen, optionally substituted C₁-C₁₂ alkyl, optionally substituted phenyl, optionally substituted pyridyl, optionally substituted C₁-C₁₂ alkanoyl, C₁-C₁₂ alkoxycarbonyl, optionally substituted C₁-C₁₂ alkylsulfonyl, optionally substituted phenylsulfonyl, optionally substituted pyridylsulfonyl, optionally substituted benzoyl, pyridylcarbonyl or C₅-C₇-cyclohexyl,
X CH or nitrogen and
R₃ is an aromatic carbocyclic or heterocyclic radical. 2. pyridone dyes according to claim 1, characterized in that
R³ is a radical of the formula means what
R⁴ for hydrogen, methyl, methoxy, C₁-C₄-alkylsulfonylamino, C₁-C₄-mono- or dialkylaminosulfonylamino or the rest -NHCOR⁹ or -NHCO₂R⁹, where R⁹ is phenyl, benzyl, tolyl or C₁-C₈-alkyl, which optionally is interrupted by one or two oxygen atoms in ether function,
R⁵ represents hydrogen, methyl, methoxy or ethoxy,
R⁶ and R⁷ are the same or different and are each independently hydrogen, C₁-C₈-alkyl, which is optionally substituted and can be interrupted by one or two oxygen atoms in ether function, or C₅-C₇-cycloalkyl and
R⁸ represents hydrogen, halogen, C₁-C₆-alkyl, optionally substituted phenyl, optionally substituted benzyl, cyclohexyl, thienyl, hydroxy or C₁-C₈-monoalkylamino and
R¹ has the meaning given in claim 1. 3. Process for transferring pyridone dyes from a support a paper coated with plastic by diffusion or sublimation tion with the help of an energy source, characterized in that one uses a carrier on which one or more dyes of Formula I according to claim 1.