CA1097618A

CA1097618A - Modification of a disazo pigment

Info

Publication number: CA1097618A
Application number: CA315,730A
Authority: CA
Inventors: Paul Muller
Original assignee: Ciba Geigy Investments Ltd
Current assignee: BASF Schweiz AG
Priority date: 1977-11-04
Filing date: 1978-11-02
Publication date: 1981-03-17
Also published as: FR2407959B1; IT7829447A0; GB2007699B; IT1100683B; GB2007699A; DE2847661A1; FR2407959A1; BR7807213A; CH629529A5; JPS5473830A

Abstract

Abstract of the Disclosure Disazo pigment of the formula

Description

The pr~sent invention relates to the new brown ~-modification of a disazo pigment. Wher~as in the range of blue, green and red pigment dyes, organic pigments satisfying the most stringent requirements with respect to fastness properties had been discovered relatively early9 a much longer time was needed before organic brown pigments having very good fastness properties were able to be produced. This became possible ? as is shown for example from the two Swiss Patent Specifications Nos.
434,520 and 561,258, by virtue of the use of diazotised nitrochloro- or trichloroanilines as diazo components.
Pigments of this type, which in themselves are doubtlessly of a very high quality, have however, in view of the environmental protection regulations now in force, a serious disadvantage as a result of the manner in which they are produced: nitrochloro- and trichloroanilines can be diazotised only by the use of nitrosylsulfuric acid or glacial acetic acid, a procedure with which are associa~ed considerable ecological problems, which can be overcome only witl grea~ difficulty and by very expensive means. Furthermore, the pigments produced with nitrochloroanilines tend to deflagrate when being ground.
In the German Offenlegungsschrift No. 2,361,433, is described in Example 1 the production of a reddish-brown ', 7~ 1 ~

disazo pigment of the formula (I3 Cl Cl ~ H ~ (I) by condensation of the azocarboxylic acid chloride of the formula (II) Cl N~l -~ COCl (II), in the molar ratio o 2:1, with 1,5-diaminonaphthalene in o-dichlorobenzene, in which process the 1,5-diamino-naphthalene, dissolved in o-dichlorobenzene, is added to a solution at 110C of the carboxylic acid chloride of the formula (II) in o-dichLorobenzene; and the mixture is subsequently heated for 18 hours at 145C. The resulting dyeg in the production of which the aforementioned ecological difficulties do not occur, has indeed good fas~ness properties, but is of little colouristic interest on account of its dull shade. The X ray diffracti.on diagram of this pigment, which is ~o be denoted in the ollowing as the a~modification, is characterised by the following lines:

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Tnterplanar spacing or Intensity of the d-value in ~ line . . . _ 10.8 very strong 9.5 medi~m 6.9 medium 4-9~ strong 4.74 medium 4.32 strong D*
4.09 medium D*
3.67 medium 3.23 very strong 3.14 medium * D = diffused, and in the range of 11.0 to 3.1 ~ there occ~ur further -~ weak lines, namely at the following d-values:
7.8 4.0 3.95 3.87 3.73 3.63 3.33 and 3.17 ~ .
It has now been found that there is surprisingly obtained a new valuable, deeply coloured, neutral-.brown crystal modifi.cation of the dye of the formula (I), called the ~-modification, the X~ray diffraction spectrum of which is characterised by the following lines:-InterplanarOspacing or Intensity of the line lO.S very strong 6.5 medium : 6.2 very strong 5.24 medium 4.78 medium 4.33 medium 4.14 medium 3.67 s~rong 3-45 strong 3.38 strong ~7~ 8 3.30 very strong 3.26 medium 3.16 medium and in the range of 11.0 to 3.1 ~ there appear further weak lines, namely at the following d-values:
` 17.2 3.5 and 3.22 ~ , by a process comprising adding undissolved 1,5-di~mino-naphthalene, optlonally together with a catalytic amount of a tertiary amine, especially pyridine, at room temperature to a suspension of the carboxylic acid chloride of the formula (II) in an inert organic solvent, heating the mixture obtained, and completing the condensation reaction at elevated temperature.
An improvement in the fastness to migration is obtained by the addition o catalytic amounts of pyridine.
It was also found that, surprisingly, the same new crystal modification, called ~-modification, is obtained by heating the a-modification of the pigment of the formula (I) in an inert high-boiling organic solvent.
Organic solvents boiling above 200C are preerred, par~icularly nitrobenzene.
The X-ray diffraction diagrams were obtained by a customary powder method, whereby the diffraction pat~ern was recorded on films. A Guinier-DeWolff No. 2 camera with CuKa radiation (~ = 1.5418 R) was employed The cali-bration substance used was a-~quartz with d-values from the ASTM File No. 5-0490. The intensity was estimated visually and dlvided into four steps: very strong /
strong / medium / weak.
The new pigment modification is suitable, in the inely dispersed form, for dyeing high-molecular, organic - ~ :
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material of natural or synthetic origin. The materials can be for example natural resins, drying oils or rubber. They can however be modified natural substances, for example chlorinat~d rubber, oil-modified alkyd resins or viscose, or cellulose derivatlves such as cellulose acetate and nitrocellulose, and particularly fully synthetic organic polyplasts, i~e. plastics produced by polymerisation, polycondensation and poly-addition. Examples which may be mentioned of this class of plastics are in particular the following: polyethylene, polypropylene, polyisobutylene, polystyrene, polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, poly-acrylates and polymethacrylates; polyesters, especially high-molecular esters of aromatic polycarboxylic acids with polyfunctional alcohols; polyamides; the condensation products of formaldehyde with phenols, the so-called phenoplasts, and the condensation products of formaldehyde with urea, thiourea and melamine, the so-called amino-plasts; the polyesters used as lacquer resins, that is both saturated resins, for example alkyd resins, and unsaturated resins, for example maleic resins, and also the polyaddition or polyco~densation products of epichloro-hydrin with polyols or polyphenols~ known under the name of "epoxide resins'l; and also the so-called thermoplasts, i.e. the thermoplastic polyplasts. It is to be emphasised that not only the homogeneous compounds but also mi~tures of polyplasts, as well as co~condensates and co-polymerisates, for example those based on butadiene, can be pig~ented with the pigment modification according ~o the invention.
It is in this respect irrelevant whether or not ~he high-molecular compounds mentioned are in the form of plastic mi~tures or of melts, or in the form of spinning 7 ~ ~

solutions, lacquers, coating materials or prin~ing inks or pastes. Depending on the purpose of application, it proves advantageous to use the pigment modification according to the invention either as a toner or in the form of preparations.
The pigment modification according to the invention is distinguished by its depth of colour, by good fastness to heat, light, weather, overlacquering, rubbing, solvents and migration, and by good dispers-ibility.
Except where otherwise stat~d in the following Examples, the term 'parts' signifies parts by weight7 percentages are per cent by weight, and the temperature values are given in degrees Centigrade.

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Flxample 1 72.2 parts o~ the azo dye obtained by coupling cliazotised l-amino-2,5-dichlorobenzene with 2,3-hydroxynaphthoic acid are heated, finely dispersed in admixture with 520 parts of o-dichlorobenzene, with stirring to 85. There is subsequently added dropwise at 80-90, in the course of 10 minutes, 32.7 parts of thionyl chloride, and the reaction mixture is further heated and held at 115-120 for 60 minutes. It is cooled to 20, and the azo dye carboxylic acid chloride, which has precipitated in crystalline form, is isola~ed by filtration, washed with a small amount of o-dichloro-benzene and then with petroleum ether, and dried at 70 in vacuo.
37095 parts of the azo dye carboxylic acid chloride thus obtained are stirred with 650 parts of anhydrous o-dichlorobenzene at 20-25 for 15 minutes. To the fine suspension are added 2.5 parts of pyridine and 7.9 parts of l,5~naphthylene diamine, and the mixture is heated and stirred for 15 hours at 140-145. The condensation product which has precipitated is filtered off at 100, and washed firstly with o-dichlorobenzene at 100, then with methanol at 20 and subsequently with water at 80.
It is finally dried in vacuo at 100 to yield 39.4 parts (93~ % of theory) of the pigment dye of the formula (I), of which the X-ray diffraction spectrum is identical to that which in the specification characterises the ~-modification. The resulting pigment dye of the ~-modifi-cation is a brown powder very difficultly soluble in organic solvents. It dyes PVC and lacquers in neutral, deeply coloured shades of brown which have very good fastness ta migration, light, weather, overlacquering and heat.

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Elementary~ nalysis of the pigment dye obtained C H Cl N 0 % found: 62.3 3.2 17.0 9.8 7.5 % calculated: 62.5 3.1 16.~ 9.9 7.6 Example 2 (Direct process) 36.1 parts of the azo dye obtained by coupling diazotised l-amino-2,5-dichlorobenzene with 2,3-hydroxy-naphthoic acid are heated, finely dispersed in admixture with 700 parts of anhydrous o-dichlorobenzene, with stirring to 85. There is subsequently added dropwise at 80-90, in the course of 10 minutes, 16.4 parts of thionyl chloride. The reaction mixture is heated and held at 115-120 for 60 minutes. The unreacted thionyl chloride, together with 50 parts of o-dichlorobenzene, is then distilled of under a slight vacuum. The azo dye carboxylic acid chloride which has formed is cooled to 20~ and 2.5 parts of pyridine and 7.9 parts of 1,5-naphthylenediamine are immediately added. The red sus-pension is heated and stirred at 140-145 for 15 hours.
The bro~n pigment which has formed is filtered off at lOQ, and processed as described in Fxample 1 to yield 40,3 parts (95.6 % of theory) of the pigment dye of the formula (I), of which,the ~-modifica~ion (characterised ~y X-ray diffrac~ion spec~rum), the shade of colour and the fastness properties are ~he same as those o the pigment dye of Example,l. ' ' ' , ..

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Example 3 Conversion of the ~-modification into the ~-modification . _ Five parts of the disazo pigment, obtained according to Example 1 of the German Offenlegungsschrift No.

2,361,433 by condensation of the azo dye carboxylic acid chloride, in the molar rato of 2.2 : 1, with 1,5-naphthylenediamine on o-dichlorobenzene, are boiled in 180 parts of nitrobenzene with stirring for 3 hours.
After cooling to 100, the pigment is filtered off, and washed firstly with a small amount of nitrobenæene at 100, then with methanol at 20 and dried at 100 in vacuo.
The yield is 4.6 parts of a brown soft pigment powder corresponding to the ~-modification. The pigment is converted by grinding or salt kneading into a form favourable for application, and in this form dyes polyvinyl chloride sheets in brown shades; it has the properties mentioned in Example 1. A longer treatment with nitro-benzene does not lead to any modification change. The ~-modification is therefore stable. For the conlersion into the ~-form, it is also possible to use other solvents boiling above 200, such as l-chloronaphthalene.
Example 4 65 parts of polyvinyl chloride, 35 parts of dioctyl-phthalate and 0.2 part of the pigment obtained according to Example 1 are mixed ~ogether, and then rolled backwards and forwards for 7 minutes at 140 on a two-roller calender to obtain a neutral brown-dyed sheet which has a deep shade of colour and very good fastness to light, weather, migration and overlacquering.

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, ~ . . , Example 5 40 parts of a nitrocellulose lacquer, 2.375 parts of titanium dioxide and 0.125 part o~ the pigment obtained in Example 1 are ground for 16 hours in a bar mil].
The lacquer resulting is applied in a thin layer to an aluminium sheet. A neutral brown lacquer coating having excellent fas~ness properties is obtained.
Example 6 A mixture of 25 parts of the pigment obtained according to Example 1, 25 parts of cellulose acetate (34.5% of bound acetic acid), lOO parts of sodium chlori~e and 50 parts of diacetone alcohol is treated in a kneader, with cooling, until the desired degree of fineness of the pigment is achieved. An addition of 25 parts of water is subsequently made and kneading is continued until a fine-granular mixture has been formed.
This is transferred to a suction filter and washed with water until no further chlorine ions are detectable in the ~iltrate. The material is dried at 85 in vacuo and afterwards ground in a hammer mill.
1.33 par~s of the pigment preparation obtained are added to an acetate rayon spinning solution consisting of 100 parts of cellulose acetate and 376 parts of acetone. Stirring is maintained for 3 hours to effect the complete dispersion of the dye. The filament obtained from this solu~ion in the usual way after the drying operation displays a neutral brown dyeing having very good fastness properties.

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Example 7 0.25 part of the dye according to Example 1 is ground with 40 parts of an alkyd-melamine stoving lacquer, which contains 50%of so~ds,and 4.75 parts of titanium dioxide for 24 hours in a bar mill. The lacquer obtained is applied in a thin layer to an aluminium sheet, and stoved for one hour at 120. The result is a brown lacquer coating having good fastness to light and to weather.
~xample 8 4.8 parts of the dye according to Example 1 are ground with 4.8 parts of the sodium salt of 1,1'-dinaphthylmethane-2,2'-disulfonic acid and 22.1 parts of water in a customary colloidal mill until all pigment particles are smaller than 1 ~. The resulting pigment suspension has a pigment content of about 15%.
If this aqueous suspension is added to the viscose spinning solution, there is obtained by the usual spinning process a cellulose filament which is dyed neutral brown and which has very good fastness properties.

Example 9 A stabîlised mixture of 100 g of a suspension polyvinyl chloride ("Hostalit C 260", Hoechst AG, K value = 60~, 1.5 g of a complex formed from barium salts and cadmium salts of higher fatty acids, complexing agents and antioxidants, as stabiliser ('IAdvastab B C 26", CIBA-GEIGY AG, Basle)~ 0.5 g of a co-stabiliser based on organic phosphite compounds (~'Advastab CH 300", CIBA-GEIGY AG, B~sle), 3.0 g of an epoxidised soyabean oil ("Advaplas~ 29", CIBA-GEIGY AG, Basle), 0.5 g of a lubricant ~, ("E-Wachs", BASF AG, Ludwigshafen)~ 2.0 g of titani~n dioxide KRONUS Cl 220", Titangesellschaft GmbH~ Lever-kusen) and ~.1 g of the pigment according to Example 1 is processed for 8 minutes at 180 on mixing rolls with a roll velocity of 20:24 (friction 1:1.2) and a roll gap of 0.3 mm, and subsequently moulded to form a 1 mm plastics sheet. The brown dyeing of the rigid polyvinyl chloride sheet has excellent fastness to rubbing, heat, migration, light and weather.
Exampl.e 10 A printing ink is ob~ained from 10 g of the pigment according to Example 1, 30 g of aluminium hydroxide and 60 g of a lithographic varnish produced on a linseed~
- oil/stand oil base, using a three-roll mill.
The printings obtained therewith in the letterpress printing process are distinguished by a beautiful bro~rn shade`having excellent fastness to light and very good fastness to solvents and to overlacquering.
_am~le 11 A stabilised mixture of 65 g of an emulsion polyvinyl chlo;ide having a K value of 72-74 ("Lonza GD", Lcnza AG, Basle), 32 g of dioctylphthalate, 3 g of an epoxidised soyabean oil as pla.sticiser ("Advaplast 39", Ciba Geigy ~G, Basle), 1.5 g of a complex, formed from~fatty-acid ~ barium salts and cadmium salts, complexing agents and antioxidants, as stabiliser ('`Advastab B C 26", CIBA-GEI~Y
AG, Basle), 0.5 g of a co-s~abiliser based on organic phosphite compounds ("Advastab CH 300", Ciba Geigy AG, Basle), 5 g of titanium dioxide ("Titandioxid KRONUS RN
56", Titangesellschaft GmbH, Leverkusen) and 0.5 g of the . pigme~t according to Example 1 is processed for 8 minutes ;iK ~ 0/ ,~, at 160 on mixing rolls with a roll velocity of 20:24 (friction 1:1.2) and a roll gap of 0.3 mm. The brown dyeing of the soft polyvinyl chloride sheet obtained in this manner has very good fastness to migration, rubbing, heat and light.
Example 1.2 A stoving lacquer formed from 20 g of titanium dioxide (for example "Titandioxid KRONUS RN 57", Titangesellschaft GmbH, Leverkusen), 40 g of a 60%
solution of a coconut oi~ alkyd resin (copolycondensate from coconut oil fatty acid, phthalic acid and pentaery-thritol) in xylene, 24 g of a 50% solution of a melamine B resin (for example "Superbeckamin 852", Reichhold-Chemie, - Hamburg) in butanol, 8 g of xylene, 7 g of ethylene gl.ycol monomethyl ether and 1 g o~ the pigment according to Ex~mple 1 is finely ground in a ball mill; it is then sprayed onto an aluminium sheet, allowed to dry and subsequently stoved at 120 for 30 minutes. The brown dyeing has very good fastness to weather, overlacquering - and heat.

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Claims

1. A disazo pigment of the formula (I) in its new .beta.-modification, characterised by an X ray diffraction diagram which shows on an interplanar spacing of 3.30, 6.2 and 10.5 .ANG. lines of very strong intensity;
at 3.38, 3.45 and 3.67 .ANG. lines of strong intensity; at 3.16, 3.26, 4.14, 4.33, 4.78, 5.24 and 6.5 .ANG. lines of medium intensity; and at 3.22, 3.50 and 17.2 .ANG. lines of weak intensity.

2. A process for producing the new .beta.-modification of the disazo pigment of the formula (I) by condensation of a carboxylic acid halide of the formula (II), in which "Hal" denotes a halogen atom, with 1,5-diamino-naphthalene in the molar ratio of 2:1, which process comprises adding the undissolved 1,5-diaminonaphthalene, optionally together with a catalytical amount of a tertiary amine, especially pyridine, at room temperature to a suspension of the acid chloride of the formula (II) in an inert organic solvent, heating the mixture obtained, and completing the condensation reaction at elevated temperature.

3. A process according to Claim 2, wherein the inert organic solvent used is a chlorinated benzene.

4. A process according to Claim 3, wherein o-dichloro-benzene is used.

5. A process according to Claim 2, wherein the conden-sation reaction is performed at temperatures between 100 and 180°C.

6. A process for producing the .beta.-modification of the disazo pigment of the formula (I) according to Claim 1, wherein the .beta.-modification of the pigment of the formula (I) is heated in an inert high-boiling organic solvent.

7. A process according to Claim 6, wherein the high-boiling organic solvent used is an organic solvent boiling above 200°C.

8. A process according to Claim 7, wherein the organic solvent used is nitrobenzene.

9. A process for pigmenting high-molecular organic material, wherein the .beta.-modification of the disazo pigment of the formula (L) is used.

10. Dyed high molecular organic material containing as pigment the .beta.-modification of the disazo pigment of the formula (I).