FR2650836A1 - PROCESS FOR THE PREPARATION OF MIXTURES OF DISAZOIC PIGMENTS - Google Patents

Abstract

Process for preparing mixtures of disazo pigments from two or more different disazo pigments, of general formula: (CF DRAWING IN BOPI) Which differ by at least one of the substituents R ** 1, R ** 2 and R ** 3, by mixed coupling of a bis-diazotized diaminodiphenyl A of formula: (CF DRAWING IN BOPI) with a mixture B of at least two coupling components which are differentiated by at least one of the substituents R ** 1, R ** 2 and R ** 3, of formula: (CF DRAWING IN BOPI) The acidic aqueous solution of diaminodiphenyl is mixed continuously, in a molar ratio A: B of 1: 2.0-2.5 A bis-diazotized which is at a pH of at most 4 with the alkaline aqueous solution of mixture B of the two coupling components of formula III at least, the pH of which is at least 12, while maintaining the pH between 4 and 7 by adjusting the addition of the reaction components, which are left to react for an average time of 1 to 5 minutes.

Description

Process for the preparation of mixtures of disazo pigments

  The invention relates to a process for the preparation of mixtures of disazo pigments by copulation.

  of an acidic aqueous solution of a diaminodiphenyl bis-

  diazotized with the aqueous alkaline solution of a mixture of

  health of copulation. The pigment mixtures thus obtained are distinguished by their perfect pigment properties as well as an extraordinarily good rheological behavior. It has been known for a long time, as can be seen in the publication of JP Sho 48-26373, that a mixed copulation of bisdiazotized diaminodiphenyl derivatives with a mixture of acetoacetanilide derivatives results in mixtures of disazo pigment having better pigment properties than the corresponding individual products, and the aforementioned Japanese publication discloses a batch process of prepration of

  mixtures of disazo pigments with a modified crystalline structure

  by reacting an acidic aqueous suspension of a mixture of acetoacetyl-m-xylidide and a monosubstituted acetoacetamide

  with an acidic aqueous solution of o-dichlorobenzidine bis-

  diazotized. It has been found today that by copulating

  continuously an acidic aqueous solution of a diaminodiphenyl bis-

  diazotized with the aqueous alkaline solution of a mixture of

  acetanilides with different substituents, mixtures are obtained

  disazo pigments with perfect pigmentary properties.

  res and have a rheological behavior surprisingly good.

  The present invention thus relates to a process for preparing mixtures of disazo pigments from two or more different disazo pigments of general formula:

CH3 X X CH3

Co CO I

HC-NN N = N-CH

I 1

CO CO

y HN (I)

R1 R2

R2 R1

  R3R which are distinguished by at least one of substituents R1, R2 and R3, substituents which, independently of one another, denote hydrogen, halogen or a C1-C4 alkyl or alkoxy, X is a halogen or a C 1 -C 4 alkyl or alkoxy, and Y is hydrogen or halogen, by mixed coupling of a bis-diazotized diaminodiphenyl (A) of formula:

X X

H2

  y Y with a mixture (B) of at least two different coupling components with at least one of their substituents R1, R2 and R31 of the formula: CH3-Co CH2-CONHXR 3 (m), R2-3-process characterized in that the acidic aqueous solution of diaminodiphenyl (A) is continuously mixed in a molar ratio A: B of 1: 2.0-2.5, preferably 1: 2.1-2.3. ) bis-diazotized which is at a pH of at most 4 with the alkaline aqueous solution, whose pH is at least 12, of the mixture (B) of at least two coupling components of formula III, different'as it has been defined above, while maintaining the pH of the medium between 4 and 7,

  preferably between 5.5 and 6.5, by adjusting the addition of

  reactions which are allowed to react with an average residence time of 1 to 5 minutes, preferably 3 to 5 minutes,

  then the mixture of pigments formed is isolated by filtration.

  Halogens can be here for example the

  fluorine, but preferably bromine and in particular chlorine.

  C1-C4 alkyls can be methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, and C1-C4 alkoxy, methoxy,

  ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy or tert-

  butoxy. The mixture B will advantageously comprise two coupling components of formula III in a molar ratio.

  from 1 to 9 to 9 to 1, and especially from 1 to 4 to 4 to 1.

  It is preferable to use in the present process a bis-diazotized diaminodiphenyl of formula:

H2N NV2

  and a mixture of two different coupling components with at least one of their substituents R 1 and R 2 of the formula: ## STR2 ## R 2 and R 2 denoting, independently, one of the other, hydrogen,

  chlorine or the methyl or methoxy group.

  It is particularly preferable that the

  ge (B) coupling components is a mixture of two different components of formula V in which R1 and R2

  are the hydrogen or the methyl group.

  It is especially preferable that the

  mixture B is a mixture of 65 to 75 mol-% of the acetoacetyl-

  xylilide of formula: CH3-CO-CH2-CONH CH3 CH3 and from 35 to 35 mol-% of the acetoacetylanilide of formula:

CH3- COCH, - CON /

  In the case of diaminodiphenyls of

  mule II and acetacetylanilides of formula III, it is generally known compounds and which are in major

part in the trade.

  It can be obtained by the general methods

  the solution of the diazo component (A), for example

  according to US Pat. Nos. 4,341,701 and 4,648,907.

  The solution of the mixture (B) of the compounds

  of copulation by mixing the two components of

  mule III in the desired proportions and dissolving the mixture, for example in a dilute or concentrated aqueous alkali liquor, advantageously in a sodium hydroxide or sodium hydroxide solution.

potash 30%.

potash 30%.

- 5--

  The two solutions above are diluted with water to the desired concentration, their concentration being

  preferably from 2 to 7% by weight, preferably from 4 to 5%.

  By "continuous mixing" it is meant that one

  The diazolic component is mixed with coupling components at substantially equal rates, preferably with a slight excess of the coupling component such that at the time the suspension leaves the reaction vessel the mixture and

  reaction are largely completed and that there is no

  pension a slight excess or even no excess of any of the components relative to a predetermined excess in any of the currents. To perform copulation under conditions

  the solution of the dia-

  zotation and the solution of the coupling components, by two individual pipes adapted to regulate the arrival of the two currents, in a reactor with a single compartment of a volume

  corresponding to the average desired residence time, and it is

  to mix solutions in an intense, pre-emptive way.

  under high turbulence, and when the residence time has elapsed the suspension formed leaves the container and is isolated by

filtering the mixture of pigments.

  To ensure intense mixing, it is necessary to

  a high shearing agent, for example the commercial apparatus called Turrax (R) (Janke und Kunkel KG, Staufen, BRD), which subjects the reaction partners to strong shearing action during their mixing and reaction , and to produce a strong turbulence in the union of the two solutions one can use very efficient agitators which

  commercially available, for example

  Turrax- (R) (Janke und Kunkel KG, Staufen, BRD), Ystral (R)

  (Ystral GmbH, Ballrechten-Dottingen, BRD), Polytron (R) (Kinema-

  tic, Kriens-Luzern, CH) and (R) Silverson Mach Ltd., Cheshem / UK), or the Chemcol (R) -Mischer (Chemiecolor AG,

Kilchberg-Ztrich, CH).

- 6 -

  It is not essential to grind or pulverize

  the particles of the product because the quick and intimate mixture

  in a relatively narrow reaction zone is normally sufficient

  to ensure the formation of a finely divided homogeneous product.

  The arrival of reagents can be regulated

  for example by means of measuring pumps or current meters, and their coupling reaction can also be adjusted in an appropriate manner with an auto-analyzer, for example as described in US Pat. No. 4,159,264, which guarantees the course

  of the reaction a minimal excess of the copulation components.

  The characteristics of the products obtained, for example filterability and dyeing and application properties, can be optimized during the

  preparation by controlling and adjusting the pH of the reaction mixture

  tional control that can easily be achieved in the process

  of this invention. Depending on the case, the pH can be adjusted by adding

  acid or alkali, the additions of which may be

  can be controlled by a pH electrode, for example by means of a brushed electrode, mounted in or next to the starting line, but pH control can also be

  do in the copulation reactor itself.

  Ordinary copulation will usually be performed

  temperatures from 0 to 50 C, preferably from 15 to 30 C.

  The properties of the pigment mixtures obtainable by the present process may be further improved by known conditioning methods as described, for example, in US Pat. Nos. 4,341,701.

4,648,907 and 4,729,796.

  The following examples explain the present invention. - 7 -

Example 1

  a) Preparation of the solution of the bis-diazotized component In a 5-liter beaker, it is suspended

  420 g (1.2 mol) 3,3'-dichloro-4,4'-diamino dihydrochloride

  diphenyl (about 72%, 3,3'-dichlorohydrochloride

  benzidine) in 431.2 g (3.78 mol) of technical hydrochloric acid

  at 32%, the suspension is cooled to between -10 and -15 ° C. with an ice bath by adding ice directly, then, while stirring constantly, 320 ml (2.46 mol) of a solution are added in 1 to 3 minutes. 40% sodium nitrite, while maintaining

  the temperature of the suspension below 5 C by an additive

  ice, and for about 30 minutes there must be a clear excess of nitrite. After the reaction, the excess nitrite is destroyed by adding 20 ml of a 15% solution of sulfamic acid, then 4.2 g of activated charcoal and 4.4 g of kieselguhr are added, the mixture is stirred for a further 10 minutes between 0 and 5 C and filtered, and wear clear red-brown solution

  at 7800 g with ice and water.

  b) Preparation of the solution of the copulation components In a 10-liter beaker 344.4 g (1.68

  mol) of 100% acetacetylxylidide, 127.6 g (0.72 mol) of

  tylanilide and 331.0 g (2.48 mol) of a 30% aqueous solution of sodium hydroxide, the mixture is heated to 7800 g with deionized water and then stirred at room temperature with

  a magnetic stirrer until it has formed a

  colorless, slightly cloudy, which takes about an hour. c) Copulation reaction In a one-liter to one-compartment reactor, with 3 separate feed lines and a feed line each provided with a suitable pump and equipped with a high-efficiency stirrer, the feed is continuous under

  constant agitation and strong turbulence 368.0 g / min of the solu-

  of the bis-diazotized component prepared above in a) by one of the introduction lines and 404.8 g / min of the solution of coupling components prepared in b) by a second

2650 & 36

  The reaction mixture is stirred and allowed to react at 20-25 ° C. with an average residence time of 1.25 minutes. By means of a pH regulator placed at the mouth in the starting line, the pH is maintained at the constant value of 6.2 by a possible adjustment of the reagents and / or by adding by the third introduction line a

  10% aqueous solution of sodium hydroxide. The suspension of the.

  a mixture of pigments which forms during the inde-

  The column is removed continuously by the starting line and the pigment mixture is filtered off, washed with water and dried, giving a yield of 96-98% of the theoretical yield, based on 3, 3'dichloro-4,4'-diaminodiphenyl. In the mixture leaving the reactor it is always possible with a probe to detect the presence of a trace of the components of

  copulation, but not the bis-diazotized compound.

  The yellow pigment thus obtained, incorporated by a common method into an oil-based printing color, shows, with good unchanged pigmentary properties, a good

  much better rheological behavior than a compositional pigment

  identical preparation which has been prepared by a known method (C.I.

Pigment Gelb 188-21094).

Example 2

  Proceeding as in Example 1 above, with the sole exception that acetacetylxylidide is replaced by the equivalent amount of acetacetyl-2,5-dimethoxy-4-chloroanilide, a yellow pigment is also obtained. 'as good

  characteristics than that of Example 1.

Example 3

  Also proceeding as in Example 1

  except that 3,3'-dichloro-4,4'-dihydrochloride is substituted for

  diaminodiphenyl by the equivalent amount of 3,3'-dimethoxy-4,4'-diaminodiphenyl dihydrochloride, an orange-colored pigment having as good characteristics as

that of Example 1.

  EXAMPLE 4 (Complementary treatment) In a 3-liter flask fitted with a stirrer is added an aqueous 10% solution of sodium hydroxide at 1420.0 g of the suspension obtained in Example 1 c) evacuated. to pH 7.0, then a solution of 70 C of 2 g of abietic acid (Staybelite Rein (R)) in 250 ml of water is added immediately.

  containing 6.0 g of sodium hydroxide.

  The mixture is heated for one hour at 95 ° C.

  then the pH is adjusted to 6.0 with hydrochloric acid

  The mixture is stirred for a further hour at 95 ° C., the temperature is then lowered to 70 ° C. by adding cold water and the pigment is filtered off, washed with water and dried. Incorporated into oil-based print colors, this pigment shows even better behavior than

  that of Example 1, with regard to both its properties and

  pigmentary tones as its rheological behavior.

Claims (6)

  1. Process for the preparation of pigment mixtures   from two different disazo pigments   or more, of general formula: X X co co HC-N = N N N - CH i i CO CO I HN HN ( y y () RS '<+ R R R1   R3 which are distinguished by at least one of substituents R1, R2 and R3, substituents which, independently of each other, denote hydrogen, halogen or a C1-C4 alkyl or alkoxy, X is a halogen or a C 1 -C 4 alkyl or alkoxy, and Y is hydrogen or halogen, by mixed coupling of a bis-diazotized diaminodiphenyl (A) of formula: D; X H35 NH2   with a mixture (B) of at least two different coupling components by at least one of their substituents R1, R2 and R3, of formula: R1 R3 IG 0 CH3-CO-CH2-CONH R3 (II),   Characterized in that the aqueous acidic solution of bis-diazotized diaminodiphenyl (A) is mixed continuously in a molar ratio A: B of 1: 2-, 0-2.5, which is at a pH of at most 4 with the alkaline aqueous solution, whose pH is at least 12, of the mixture (B) of at least two coupling components of formula III, different as defined above, while maintaining the pH of the medium between 4 and 7 by controlling the addition of the reaction components, which is allowed to react with a   average residence time of 1 to 5 minutes, then isolated by   tration the pigment mixture formed.   2. Method according to claim 1, characterized   in that the mixture (B) consists of two copula components   formula III in a molar ratio of 1 to 9: 9 to 1.   3. Process according to claim 1, characterized in that a bis-diazotized diaminodiphenyl of formula H2N NH2 (I) -   and a mixture of two copulation components that differ   by at least one of their substituents R1 and R2, of mule: CH3-COCH, -CONH R2 (V), R1   R 1 and R 2 each independently of one another   chlorine or the methyl or methoxy group.   4. Method according to claim 3, characterized   in that the mixture (B) of copula components   a mixture of two components of formula V are   at least one of their substituents R 1 and R 2, each of which independently of one another is hydrogen or the methyl group.   5. Process according to claim 3, characterized in that a mixture of 65 to 75 mol% of acetoacetyl xylilide of formula: CH-CO-CH 2 -CONH CH 3   CH 3 and from 25 to 35 mol% of the acetoacetylanilide of formula: CH3- CO- CH - CONH   6. Method according to claim 1, characterized   in that the molar ratio A: B is 1: 2.1-2.3.