Patentamt 0 081 840 JEuropàischesEuropean Patent Office ® Publication number: B1 Office européen des brevets

® EUROPEAN PATENT SPECIFICATION

® Date of publication of patent spécification: 29.10.86 © Int. Ci.4: C 09 B 67/16 (à) Application number: 82111576.3 ® Dateoffiling: 14.12.82

1

(54) Copper phthalocyanine pigment process.

(30) Priority: 14.12.81 US 330333 @ Proprietor: TOYO INK Manufacturing Co., Ltd. No. 3-13, Kyobashi 2-chome Chuo-ku Tokyo (JP) (§) Date of publication of application: 22.06.83 Bulletin 83/25 @ Inventor: Fitzgerald, Patrick Henry 640 Howard Avenue ® Publication ofthe grant of the patent: Pitman New Jersey 08071 (US) 29.10.86 Bulletin 86/44

® Representative: Abitz, Walter, Dr.-lng. et al (M) Designated Contracting States: Abitz, Morf, Gritschneder, Freiherr von DE FR GB IT Wittgenstein Postfach 86 01 09 D-8000 Munchen 86 (DE) (§) References cited: GB-A-2043 094 US-A-3 051 720 US-A-4 289 698 BERICHTE DER BUNSENGESELLSCHAFT FUR PHYSIKALISCHE CHEMIE, vol. 71, no. 3, 1967, pages 239-342, Weinheim, DE., B. HONIGMANN: "Physikalische Grundlagen der anwendungstechnischen Eigenschaften von Pigmenten"

The file contains technical information submitted after the application was filed and not included in this specification Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed untîl the opposition fee has been paid. (Art. 99(1 ) European patent convention). Courier Press, Leamington Spa, England. sulfonated semichloro copper phthalocyanine in the initial slurry being at least 4.5, stirring in the Background of the Invention initial slurry being at least 4.5, stirring the slurry The present invention relates to a process for while maintaining its temperature at from 50° to converting crude semichlorinated copper 85°C for from 1/2 to 4 hours, diluting the slurry phthalocyanine or crude partially sulfonated with water to less than 35 weight percent sulfuric semichlorinated copper phthalocyanine into a acid in water, stirring the diluted slurry at from 60° highly transparent pigment of high tinctorial to 95°C for from 1/2 to 4 hours and recovering strength. pigmentary grade semichloro copper phthalo- In the past crude copper phthalocyanine has cyanine or partially sulfonated semichloro copper been converted to pigmentary grade material by phthalocyanine. solvent milling as disclosed in U.S. 2,799,594 and U.S. 2,799,595 or by acid pasting as disclosed in Detailed Description U.S. 3,024,247. The products produced in this The premilling step of the present invention is manner do not exhibit high transparency, and that conventionally used for ball milling opera- encapsulation in polymers, such as disclosed in tions. Thus the charge of grinding media will U.S. 3,806,464, has been used to improve trans- occupy about half of the volume of the mill anti parency. The process of the present invention the copper phthalocyanine being ground will involves an acid treatment of a preground semi- essentially occupy the voids between these chlorinated copper phthalocyanine pigment, media. It is quite possible to increase the charge which is lower in cost than either acid pasting or with some increase in milling time. The choice of solvent milling and produces highly transparent these conditions is well within the skill of one products without the complication of added versed in this type of operation. The preferred polymeric resins. grinding media in the mill is the rod type, which The effect of contact with sulfuric acid solutions may vary in size; but it is quite possible to use of various concentrations on the crystal phase of ordinary round steel balls varying from 1/8 inch copper phthalocyanine and monochloro copper (0.32 cm) in diameter up to 1/2 inch (1.27 cm) in phthalocyanine has been described by B. Honig- diameter or more in the operation. When round mann et al Zeitschrift fur Kristallographic 122, pp balls are used there is a marked tendency for the 185-205 (1965) and B. Honigmann, Berichte der charge to cake in the mill, under some conditions, Bundesgesellschaft, 71 (1967). which tendency generally can be avoided by the U.S. 3,051,720 discloses a process for the com- addition of materials of an irregular shape, such minution of crude phthalocyanine pigment which as nails, to the charge. The use of the rod type comprises in a preferred embodiment the follow- grinding media usually avoids this caking. ing steps. A phthalocyanine is dry ground for For use in the present invention ball milling is about 6 hours in a conventional manner in a ball preferred over sand milling or salt milling. mill in the absence of any grinding aid. After the It is impossible to set up limits as to the length discharge of the dry pigment from the mill, it is of the milling cycle, since it will vary with the mill slurried in 3-4 parts of sulfuric acid of about loading and the type of mill being used. In order 65-85% concentration, and after complete wet- to establish the optimum length of time for the ting, it is allowed to stand in contact with the acid milling, it is recommended that the invention be for about one hour at about room temperature, run with variations in the milling time and the e.g. in the range of 10-30°C. The slurry is then samples evaluated for the best balance of rapidly diluted with a relatively large amount of properties such as color strength, intensity, dis- water, heated for a short time near the boiling persibility and transparency. A minimum of 4-6 point, and then filtered, washed free of soluble hours is usually required, and this may be ex- salts and dried in a conventional manner to give a tended to as much as 12-18 hours or even more pigment of superior tinctorial properties. How- on a commercial scale mill. Considerably longer ever the product of this process is not completely times are required when using a semi-works or satisfactory regarding transparency and rheo- laboratory scale mill. logical properties. After the premilling step the pigment is in the form of a highly agglomerated material of low Summary of the Invention crystallinity which is of little value as a pigment. The present invention relates to a process In accordance with the present invention after comprising premilling a crude semichloro copper the premilling step the premilled semichloro cop- phthalocyanine or a crude partially sulfonated per phthalocyanine is contacted with aqueous semichloro copper phthalocyanine, forming a sulfuric acid. In the case of semichloro copper slurry of the premilled material in an aqueous phthalocyanine the sulfuric acid concentration solution of sulfuric acid of elevated temperature should be from 50 to 60% by weight and prefer- and of 50 to 60 percent by weight strength in the ably from 55 to 59% by weight. In the case of case of semichloro copper phthalocyanine or of partially sulfonated semichloro copper phthalo- 50 to 61 percent by weight strength in the case of cyanine the sulfuric acid concentration should be partially sulfonated semichloro copper phthalo- from 50 to 61 % by weight with from 58 to 61 % by cyanine, the weight ratio of aqueous solution of weight being preferred. If an acid concentration sulfuric acid to partially sulfonated or un- below 50% is used the premilled powder is not sufficiently deaggregated and a weak, dull pro- Examples duct with a milky scatter in metallic finishes will In the following examples all "parts" are by result. If acid greater than 60% (61% in the case of weight. partially sulfonated semichloro copper phthalo- cyanine) the product will have the less desirable Example I greener weaker all phase and will be less trans- Preparation of the Mill Powders parent. Forty-eight parts of the crude copper phthalo- The weight ratio of sulfuric acid solution to pre- cyanine (as described in a or b below) was rolled milled pigment is at least 4.5 and is preferably at 70% of critical speed (critical speed is the speed 4.5-5.5 to 1. At lower levels the pigment is at which centrifugal force overcomes the force of moderately wet and does not give a stirrable gravity so that the grinding elements are retained mass. Larger amounts of sulfuric acid can be used against the outer wall of the mill) with 1000 parts but are undesirable for economic reasons. The of 5/8" (1.6 cm) x 1" (2.54 cm) steel rods for 6 acid is at an elevated temperature when added to hours and discharged through a screen. the pigment. The resulting slurry is stirred at 50° a. The crude copper phthalocyanine used to 85°C for from 1/2 to 4 hours. This slurry is then for the milling contained about 4.0% chlorine as diluted to less than 35 wt % sulfuric acid in the obtained by isolating the product of the reaction aqueous phase and stirred at 60° to 95°C for 1/2 to 4-chlorophthalic acid and phthalic anhydride with 4 hours. The pigment is then isolated in the urea and copper chloride in kerosene and in the conventional manner, such as by filtering and presence of ammonium molybdate. drying. Surfactants and/or other treating agents b. The crude copper phthalocyanine used for may be added during either stage of the process. the milling contained about 4.0% chlorine and As used herein semichloro copper phthalo- 0.27% sulfur as obtained by isolating the product cyanine means copper phthalocyanine containing of the reaction of 4-chlorophthalic acid, 4-sulfo- from 3 to 5 percent by weight chlorine. As used phthalic acid and phthalic anhydride with urea herein partially sulfonated semichloro copper and copper chloride in kerosene and in the pre- phthalocyanine means semichloro copper sence of ammonium molybdate. phthalocyanine in which up to 15% of the semi- chloro copper phthalocyanine molecules contain Example II a sulfonic group derived from 4-sulfophthalic To a solution of 6 parts dicocodimethyl- anhydride or 4-sulfophthalic acid during syn- ammonium chloride and 285 parts 96% sulfuric thesis of the semichloro copper phthalocyanine. acid in 179 parts water at 70°C is added 100 parts The products of the present invention are ex- of the mill powder from Example 1a. The slurry is ceptionally transparent in automotive acrylic stirred at 70 ± 2°C for 2 hours. Then the slurry is lacquers and enamels. This is especially impor- diluted with 958 parts water and is stirred at tant in the case of automotive enamels and 92-94°C for 2 hours. Then the pigment is isolated lacquers based upon solvent solutions of acrylic by filtration, water washing at 50°C and drying at polymers and containing metal particles, i.e., 80°C in the normal manner. The product is a dark aluminum flake, to provide a metallized or "poly- red shade blue pigment which is strong and chromatic" finish. These finishes provide rich, intense when compared to that prepared by a glamorous, decorative effects due to their conventional solvent method. apparent enhancement of curvature. The phenomenon is known as geometric meta- Example III merism, but more commonly is referred to in the The process is identical to that of Example II, automotive industry as "two-tone" effect or "flip- except that after 1-1/2 hours of stirring at flop." It is observable as a change in color depth, 92-94°C, the slurry is cooled to below 85°C and a and often hue, as a function of viewing angle. This solution of 5.3 parts of CPC-monosulfonic acid in is apparent on an automobile by comparing the 66 parts of 96% sulfuric acid is added. Then the appearance of different body contours. On a flat slurry is stirred a further 1/2 hr. at 92-94°C and surface, the effect may be observed by slowly the product isolated as in Example II. The product rotating a paint panel from a normal to an obtuse is strong, intense and has superior rheological angle. The color should increase in depth as the properties in acrylic enamels when compared to viewing angle changes in any direction from the products from a conventional acetone milling normal. In any case the effect, which is caused by process. specular reflection of the flake pigment, is diminished if the colored pigment scatters light Example IV diffusely. The so-called "transparent" pigments, To a solution of 291 parts of 96% H2SO4 in 182 then, are those which are free from particles large parts of water at 68-72°C is added 100 parts of enough to cause diffuse scattering. To be suitably mill powder from Example I-b. The slurry is transparent an organic pigment should generally stirred at 68-72°C for 1-1/2 hours and then is have crystallite sizes less than 0.1 u and should diluted with 820 parts water and stirred at resist particle agglomeration during the various 70-75°C for 1-1/2 hours. The pigment is then phases of pigment manufacture and during isolated as in Example II in the normal manner. formation of the finish itself. The product is strong, intense and very trans- parent in acrylic dispersion lacquer. It gives better rheological properties and gasoline resistance in 2. The process of Claim 1 wherein semichloro lacquer systems than polymer encapsulated pig- copper phthalocyanine is being treated. ment such as prepared by the process of U.S. 3. The process of Claim 2 wherein the aqueous 3,806,464 while providing equal or better "flip- slurry is formed using from 55 to 59 percent by flop." The remaining examples are to illustrate weight sulfuric acid. the process limits. 4. The process of Claim 3 wherein the initial sulfuric acid slurry is maintained at from 65° to Example V 75°C. Three solutions of 287.5 parts of 96% sulfuric 5. The process of Claim 4 wherein the weight acid in 188 parts water were prepared and ratio of the aqueous solution of sulfuric acid to brought to temperature. semichloro copper phthalocyanine in the initial slurry is from 4.5 to 5.5/1. 6. The process of Claim 1 wherein partially sulfonated semichloro copper phthalocyanine is being treated. 7. The process of Claim 6 wherein the aqueous To each was added 100 parts of the mill powder slurry is formed using from 58 to 61 percent by from I-a and each was stirred 1-1/2 hours at weight sulfuric acid. temperature. Then each was diluted with 860 8. The process of Claim 7 wherein the initial parts water and heated to 92-94°C and stirred for sulfuric acid slurry is maintained at 65° to 75°C. 1-1/2 hours. The products were isolated as in 9. The process of Claim 8 wherein the weight Example II. The product of V-a was very weak, ratio of the aqueous solution of sulfuric acid to dull, and opaque compared to that of V-b. The partially sulfonated semichloro copper phthalo- product of V-b was very weak, dull, and opaque cyanine is from 4.5 to 5.5/1. compared to that of V-c.

Example VI The process was run like that in Example V-c, except that the product was isolated as in 1. Verfahren umfassend das Vormahlen eines Example immediately after dilution, without any rohen Semichlorkupferphthalocyanins oder eines heat up or stir period. The product was opaque rohen, teilweise sulfonierten Semichlorkupfer- and very weak to that of V-c. phthalocyanins, Bilden einer Aufschlämmung des vorgemahlenen Materials in einer wässrigen Example VII Schwefelsäurelösung von erhöter Temperatur To a solution of 291 parts 96% H2SO4 in 1000 und einer Konzentration von 50 bis 60 Gew.-% im parts water (21.7% acid) was added 100 parts of Fall von Semichlorkupferphthalocyanin, oder von the mill powder from I-a. The slurry was heated to 50 bis 61 Gew.-% im Fall von teilweise sulfonier- 92-94°C and stirred for 1-1/2 hours. Then the tem Semichlorkupferphthalocyanin, wobei das product was isolated as in Example II. Gewichtsverhältnis der wässrigen Schwefel- The product was extremely dull and opaque säurelösung zu teilweise oder nicht sulfoniertem and extremely weak to that of Example V-c. Semichlorkupferphthalocyanin in der anfäng- lichen Aufschlämmung mindestens 4, 5 beträgt, Rühren der Aufschlämmung unter Aufrechterhal- tung einer Temperatur von 50 bis 85°C während 1. A process comprising premilling a crude einer Zeitdauer von 1/2 bis 4 Stunden, Verdünnen semichloro copper phthalocyanine or a crude der Aufschlämmung mit Wasser bis zu einer partially sulfonated semichloro copper phthalo- Schwefelsäurekonzentration von weniger als 35 cyanine, forming a slurry of the premilled Gew.-% in Wasser, Rühren der verdünnten Auf- material in an aqueous solution of sulfuric acid of schlämmung bei einer Temperatur von 60 bis elevated temperature and of 50 to 60 percent by 95°C während einer Zeitdauer von 1/2 bis 4 Stun- weight strength in the case of semichloro copper den und Gewinnung von Semichlorkupfer- phthalocyanine or of 50 to 61 percent by weight phthalocyanin bzw. teilweise sulfoniertem Semi- strength in the case of partially sulfonated semi- chlorkupferphthalocyanin zu pigmentüblicher chloro copper phthalocyanine, the weight ratio of Qualität. aqueous solution of sulfuric acid to partially 2. Verfahren nach Anspruch 1, bei welchem sulfonated or unsulfonated semichloro copper Semichlorkupferphthalocyanin behandelt wird. phthalocyanine in the initial slurry being at least 3. Verfahren nach Anspruch 2, bei welchem die 4.5, stirring the slurry while maintaining its wässrige Aufschlämmung unter Verwendung von temperature at from 50° to 85°C for from 1/2 to 4 Schwefelsäure einer Konzentration von 55 bis 59 hours, diluting the slurry with water to less than Gew.-% gebildet wird. 35 weight percent sulfuric acid in water, stirring 4. Verfahren nach Anspruch 3, bei welchem die the diluted slurry at from 60° to 95°C for from 1/2 anfängliche Schwefelsäureaufschlämmung auf to 4 hours and recovering pigmentary grade einer Temperatur von 65 bis 75°C gehalten wird. semichloro copper phthalocyanine or partially 5. Verfahren nach Anspruch 4, bei welchem das sulfonated semichloro copper phthalocyanine. Gewichtsverhältnis von wässriger Schwefel- säurelösung zu Semichlorkupferphthalocyanin in dant 1/2 heure à 4 heures, la dilution de la bouillie der anfänglichen Aufschlämmung 4, 5 bis 5, 5/1 avec de l'eau à moins de 35% en poids d'acide beträgt. sulfurique dans l'eau l'agitation de la bouillie 6. Verfahren nach Anspruch 1, bei welchem teil- diluée entre 60 et 95°C pendant 1/2 heure à 4 weise sulfoniertes Semichlorkupferphthalocyanin heures et le recueil de phtalocyanine de cuivre behandelt wird. semi-chlorée ou de phtalocyanine de cuivre semi- 7. Verfahren nach Anspruch 6, bei welchem die chlorée partiellement sulfonée de qualité pigmen- wässrige Aufschlämmung mit Schwefelsäure taire. einer Konzentration von 58 bis 61 Gew.-% gebil- 2. Un procédé selon la revendication 1, dans det wird. lequel on traite de la phtalocyanine de cuivre 8. Verfahren nach Anspruch 7, bei welchem die semi-chlorée. anfängliche Schwefelsäureaufschlämmung auf 3. Un procédé selon la revendication 2, dans einer Temperatur von 65 bis 75°C gehalten wird. lequel on forme la bouillie aqueuse en utilisant de 9. Verfahren nach Anspruch 8, bei welchem das 55 à 59% en poids d'acide sulfurique. Gewichtsverhältnis der wässrigen Lösung von 4. Un procédé selon la revendication 3, dans Schwefelsäure zu teilweise sulfoniertem Semi- lequel la bouillie initiale à l'acide sulfurique est chlorkupferphthalocyanin im Bereich von 4, 5 bis maintenue entre 65 et 75°C. 5, 5/1 liegt. 5. Un procédé selon la revendication 4, dans lequel le rapport en poids de la solution aqueuse d'acide sulfurique à la phtalocyanine de cuivre semi-chlorée dans la bouillie initiale est compris 1. Un procédé comprenant un broyage pré- entre 4, 5 et 5, 5 pour 1. alable d'une phtalocyanine de cuivre semi- 6. Un procédé selon la revendication 1, dans chlorée brute ou d'une phtalocyanine de cuivre lequel on traite de la phtalocyanine de cuivre semi-chlorée partiellement sulfonnée brute, la semi-chlorée partiellement sulfonée. formation d'une bouillie de la matière pré-broyée 7. Un procédé selon la revendication 6, dans dans une solution aqueuse d'acide sulfurique à lequel on forme la bouillie aqueuse en utilisant de température élevée et d'un titre de 50 à 60% en 58 à 61 % en poids d'acide sulfurique. poids dans le cas de phtalocyanine de cuivre 8. Un procédé selon la revendication 7, dans semi-chlorée ou de 50 à 61 % en poids dans le cas lequel la bouillie initiale à l'acide sulfurique est de phtalocyanine de cuivre semi-chloré4 partielle- maintenue entre 65 et 75°C. ment sulfonée, le rapport en poids de la solution 9. Un procédé selon la revendication 8, dans aqueuse d'acide sulfurique à la phtalocyanine de lequel le rapport en poids de la solution aqueuse cuivre semi-chlorée partiellement sulfonée ou d'acide sulfurique à la phtalocyanine de cuivre non-sulfonée dans la bouillie initiale étant d'au semi-chlorée partiellement sulfonée est compris moins 4, 5 l'agitation de la bouillie tandis qu'on entre 4, 5 et 5, 5 pour 1. maintient sa température entre 50 et 85°C pen-