JPH0358389B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an aggregated low crystallinity form of crude quinacridones.
The pigmentary form is then converted into a pigmentary form in the presence of a recoverable organic liquid.

As-synthesized quinacridones, known as crude quinacridones, are generally unsuitable for use as pigments and may be further processed to obtain the required pigmentary properties, such as particle size, particle shape, crystalline structure. It is well known in the industry that coloring strength, hue, etc. must be developed. The most commonly used process to convert crude quinacridones into pigmentary form is to mill the crude quinacridones with large amounts of inorganic salts and then
including extracting the resulting ground powder.
Although this salt grinding operation can produce pigments that are satisfactory for some applications, it has two weight disadvantages. First, it requires the use of large amounts of salt, which severely limits the amount of pigment that can be charged to the mill, and the salt must be disposed of; second, the resulting pigment The particles are often acicular, creating rheological problems in end uses such as high solids acrylic paints for automobiles.

Various attempts have been made to avoid the use of salt in grinding crude quinacridone. For example, in US Pat. No. 2,857,400, the crude pigment is ground in a ball mill and then homogenized in acetone and recovered from the acetone. In U.S. Pat. No. 3,017,414, the crude pigment is pre-milled in a ball mill and then treated with an organic liquid such as an emulsion of chlorobenzene in water.
Recover from emulsion. As with salts, disposal of organic liquids presents problems.

Another method of producing pigmentary quinacridone from crude quinacridone is disclosed in U.S. Pat. After heating to 150-300℃ under pressure. Special equipment is required for heating at high temperatures and pressures.

In another method (US Pat. No. 4,094,699) that eliminates the use of organic liquids, pre-milled quinacridone is ripened in an aqueous base in the presence of both cationic and nonionic surfactants.
Some surfactant remains on the surface of the pigment, which can cause compatibility problems in some end applications.

The present invention involves converting crude quinacridone into an aggregated low crystallinity form and then grinding in the presence of an organic liquid to convert this aggregated low crystallinity quinacridone into easily dispersible pigmentary quinacridone. include.

The method of the present invention provides quinacridone pigments of essentially any desired particle size and thus allows parameters that influence the rheological properties of the pigmented product, with or without particle size growth inhibitors. It gives an opportunity to control one of the Even small amounts of 2-phthalimidomethylquinacridone have a significant effect on the particle size of the resulting product. This particle size growth inhibitor can be incorporated during the milling step with the liquid or during the pre-milling step prior to this step. The efficiency of the growth inhibiting action is enhanced if it is incorporated during the pre-grinding operation.

Control of the particle size of solid solution quinacridone pigments is difficult with prior art dispersion milling processes, such as those described in U.S. Pat. This is because it relies on ripening and extraction steps in dilute sulfuric acid, which are relatively ineffective at growing particles from low crystallinity materials. Additional milling cannot be used to correct this, as it would result in a product exhibiting incomplete solid solution formation. According to the conditions of the present invention, complete solid solution is usually achieved in the particles of the final pigment product as having particle sizes of various sizes. The method of the present invention allows for a wide range of applications, either by incorporating particle size growth inhibitors or by modifying the organic liquid used to control the effect on the particular quinacridone used. The conditions necessary to obtain a pigment of desired particle size over a range of particle sizes are provided.
Thus, the method of the present invention allows relatively large particle size pigments to have a high tinctorial strength, such as that normally exhibited by small particle size pigments, yet has a higher tinctorial strength than that of larger particle size pigments. It can be used to produce products that exhibit excellent light-fastness.

Another advantage of the present invention is that it avoids the need to use interfering surfactants depending on the end use.

In a preferred embodiment of the invention, the component that becomes part of the final pigment, whether it is a single quinacridone component or a binary, ternary or quaternary solid solution, In order to avoid the possibility of explosion of the powder produced, the material is ground together in a conventional ball mill with about 8-10% inorganic salt, e.g. sodium sulfate, based on the pigment, and the material is aggregated into a low-crystalline powder. Grind to a high degree of material. The addition of sodium sulfate is not essential as the product is highly aggregated and not dusty. The resulting ground powder is then ground in an easily recoverable organic liquid in the presence or absence of a particle size growth inhibitor.

Any organic liquid can be used that has an effective wetting action on the pigment particles and is capable of growing these particles from an aggregated low crystallinity material into a pigmentary material. Furthermore, the organic liquid must be sufficiently volatile, either by steam distillation or direct distillation, and must not corrode the mill and grinding parts. A wide range of organic liquids are suitable, and suitable organic liquids will vary depending on the nature and solubility of the pigment.

Alcohols such as methanol and isopropanol, ketones such as acetone and methyl ethyl ketone, and hydrocarbons such as chlorinated hydrocarbons such as carbon tetrachloride, tetrachlorethylene and 0-dichlorobenzene may be used. The choice of organic liquid will depend on the particular pigment being produced and will be influenced by the organic liquid's cost, ease of recovery, and hazards of use. High boiling liquids are generally more difficult to recover by steam distillation and therefore more expensive. other liquids,
For example, chlorinated hydrocarbons are toxic and therefore undesirable. On the other hand, low boiling point liquids, such as acetone, tend to be easily flammable, but are otherwise desirable for reasons such as their low cost, non-toxicity, and ease of distillation. The advantage of acetone and low-boiling alcohols is that they are miscible with water, and therefore their ability to grow pigment particles can be modified by dilution with water during the grinding process with organic liquids. It is possible. Dilution with water yields a product with smaller particle size.

The objects of the present invention are achieved by first converting the crude quinacridone pigment into an aggregated, low crystallinity material. This can be done by grinding the crude pigment or pigments in the dry state in a grinding device that applies shear and abrasion to the aggregated low crystallinity product.

The pre-grinding used in the present invention refers to a state in which no liquid is present, or when a liquid is used, a phase directing solvent or a surfactant, etc. Alternatively, it means that the resin is present in such a small amount that it retains its powder properties, and that it is ground in such a state that it has such properties.

As a variant, the aggregated low crystallinity quinacridone pigment can be prepared by dissolving the crude quinacridone in concentrated sulfuric acid;
Obtained by drowning the solution in a large amount of cold water. In both cases, highly aggregated pigments with low crystallinity are affected by friction (by
rubout) The color strength is weak and it is not that valuable.

A preferred method for use in the present invention is to ball mill the crude quinacridone or quinacridones in the dry state in a conventional manner and then ball mill the ground powder in sufficient organic liquid to provide a fluid slurry.・Includes milling.

The quinacridone pigments to which the present invention applies generally have the formula or expression quinacridone, or a mixture thereof; and 0 to 75% by weight and 15% by weight of unsubstituted quinacridone,
Preferably up to 5% by weight of the formula quinacridone, in which R ¹ ,
R ² is fluorine, chlorine, bromine, methyl or methoxy; R ³ , R ⁴ , R ⁵ and R ⁶ are hydrogen, fluorine, chlorine, bromine, methyl or methoxy; R ⁷ , R ⁹ and R ¹⁰ is hydrogen or chlorine, R ⁸ is hydrogen, chlorine, bromine, nitro, an alkyl group of 1 to 5 carbon atoms, an alkoxy group of 1 to 2 carbon atoms, or benzoylamino,
and m will consist essentially of an integer from 1 to 4.

The phrase "consisting essentially" is not intended to exclude the presence of small amounts of other substances, such as dihydroquinacridone stabilizers, but to ignore other substances that would impair the pigmentary properties of the quinacridone pigment. It is intended to exclude the existence of quantities that cannot be used.

It is not possible to give a limit on the length of the milling step in the liquid, as it will vary depending on the particular quinacridone or mixture of quinacridones being treated, the mill charge and the type of mill used. In order to establish the optimal time for milling a particular pigment under a given set of conditions, the present invention can be practiced varying both milling times, and samples of the resulting product can be It is recommended to compare with a standard sample showing a certain degree of pigment quality. Typically, commercial scale mills require a minimum of 4 to 6 hours of grinding, but this may extend to 12 to 18 hours or even longer. For laboratory-scale or intermediate-scale mills, considerable time is required. Generally, grinding in liquid is 10 to 60
℃, preferably 20-50℃.

Following the milling operation, the quinacridone pigment is usually extracted in hot dilute acid, such as 1.5% sulfuric acid, to remove any metals that may have entered the pigment during milling. Following the extraction process, the pigment is dried.

While normally produced quinacridone pigments are often acicular in shape, the pigment particles produced by the present invention are generally tabular in shape. The quinacridone pigments produced by the method of the present invention are much better dispersible than conventional quinacridone pigments, and due to their tabular shape and controllability of particle size, the quinacridone pigments produced by the method of the present invention The resulting pigments have improved rheological properties compared to previous quinacridone pigments. This is due to the dark color type of new high solids thermosetting acrylic paints developed for automotive applications.
styings) are most obvious. The quinacridone pigments prepared in accordance with the present invention are useful in these systems, whereas conventional quinacridone pigments of all sizes could not be practically used in these systems due to their high viscosities. The product also exhibits improved rheological properties in conventional thermoset and thermoplastic systems.

Hitherto, it has been difficult to obtain a satisfactory 2,9-dichloroquinacridone pigment or its solid solution with quinacridone for the dark type of high solids paints. By practicing the invention, 75% 2,9-dichloroquinacridone and 25%
Solid solutions of quinacridone or satisfactory pigments of 100% dichloroquinacridone are readily prepared for use in new high solids coatings. Attractive 2,9-dimethylquinacridone pigments or their solid solutions with quinacridone can be prepared in a similar manner.

The use of particle growth inhibitors results in products with smaller particle sizes and, when properly dispersed in either thermosetting paints or thermoplastic lacquers for automatic topcoating, provides increased strength and mechanical properties. A result of geometric mesomerism (commonly referred to as the so-called "seatone" effect or flip-flop) is obtained. This latter property is particularly relevant to artistic value, manifesting itself in changes in color depth and sometimes hue depending on the viewing angle. This effect is observed by gently rotating a flat panel covered with a metallic finish from vertical to an obtuse angle. Increasing the sheet tone increases the depth of the color as you change the viewing angle from vertical to either direction. The greater "seatone" effect observed in product particles aged in the presence of 2-phthalimidomethylquinacridone
This is due to the creation of pigments with smaller particle sizes, which when properly dispersed exhibit less light scattering and an increased "seatone" effect. The greater the degree of "seat tone" achieved with the pigments produced by this method, the better they are than products containing no or only small amounts of pigment growth inhibitors, as can also be confirmed by X-ray measurements. are also shown to have effective smaller particle sizes.

The products obtained by treatment with aluminum quinacridone sulfonate give pigments with a large "two-tone" and therefore artistic appearance in thermoset acrylic coating systems, as well as significantly improved rheological properties.

In the following examples, all parts are by weight.

EXAMPLE Two laboratory scale ball mills each had 1500 1/2 inch diameter steel balls and 150 roofing nails.
1 part, 45 parts of 2,9-dimethylquinacridone, 5 parts of quinacridone, and 5 parts of anhydrous sodium sulfate. The mill is driven to a "critical speed" (critical speed is when the centrifugal force overcomes the gravity of the grinding media).
Rotate for 96 hours at a speed of approximately 74% of the speed at which the elements) become held against the outside wall of the mill. Open the mill and remove the steel balls and nails through a sieve to remove its contents.

Next, the obtained powder (12 parts) was mixed with a diameter of 3.2 mm (1/8
Each of four laboratory-scale ball mills containing 600 parts of steel shot (1 inch) and 79 parts of acetone were charged. Run the mill at approximately 74% of its critical speed for 72 hours. Remove the contents of the mill and use a sieve to remove the steel pellets. Wash the shotgun with acetone to ensure that essentially all the pigment slurry is collected. Steam is passed through the slurry until a temperature of 95°C is reached. Acetone is completely removed by holding at a temperature of 95°C for 10 minutes. Cool the slurry to 85°C and add 104 parts of 33% sulfuric acid aqueous solution to it. 1. Heat the slurry to 80-85℃.
Hold time. Collect the product by filtration, wash with water until acid free, and dry at 80°C to obtain 43.2 parts of pigment. When tested by friction in lithographic varnish,
This product is superior in masstone to commercially available 2,9-dimethylquinacridone.
similar in size and at least 10% larger in coloration intensity.

After adding 104 parts of 33% sulfuric acid aqueous solution, the temperature was increased to 80
This example is repeated except that the temperature is held at ~85°C for half an hour, then 1.5 parts of 2-phthalimidomethylquinacridone is added as an aqueous dispersion and heating is continued at 80-85°C for an additional half hour. Collect the product through filtration, wash with water until acid free, and dry at 80°C. This product shows particularly good rheological properties and very good coloring properties when tested in thermosetting automotive paints. The kneading base material (millbase) of the created automobile mochi has a food cup viscosity of 34.
2,9-dimethylquinacridone has a Ford Cup viscosity ranging from 44 to 61 seconds. This has clear advantages in terms of handling of the kneaded substrate and in the finishing of the final vehicle.

EXAMPLE The present invention demonstrates the effect on particle size of partitioning the conversion of 2-phthalimidomethylquinacridone by adding it in part during the co-milling step with acetone.

“Cyl-Pebs” for intermediate scale ball mills,
1000 cylinders made of steel, approximately 1.27 cm (1/2 inch) in diameter and approximately 1.27 cm (1/2 inch) long;
penny”, i.e. 100 pieces of 10 cm (4 inch) needles, 2,
Charge 40 parts of 9-dimethylquinacridone and 4 parts of anhydrous sodium sulfate. Rotate the mill at 40 rpm (approximately 74% of critical speed) for 48 h at 55-60 °C. Open the mill, take out the contents, and remove the "Cyl-Pebs" and nails with a sieve.

Then, a part (0.029 part) of the obtained crushed powder was
1.32 parts of 3.2 mm (1/8 inch) diameter steel shotgun, 2
- Charge two laboratory scale ball mills containing 0.00026 parts of phthalimidomethylquinacridone and 0.17 parts of acetone. Run the mill at approximately 74% of its critical speed for 72 hours. Remove the contents of the mill onto a sieve to remove the steel pellets. The shot is washed with acetone so that essentially all the pigment is collected as a slurry. Steam is passed through the slurry until the temperature reaches 95°C. Holding the temperature at 95°C for 10 minutes will completely remove the acetone. 85 slurry
Cool to ℃ and add 0.11 parts of 33% sulfuric acid to it. The slurry is held at 80-85°C for half an hour and then treated with 0.00052 parts of 2-phthalimidomethylquinacridone. Continue heating at 80-85°C for another half hour. Collect the product through filtration, wash with water until the acid is gone, and heat at 80°C.
Dry with. When tested by rubbing in lithographic varnish, the product is noticeably darker (smaller particle size) in masstone, but 2-
It is exactly the same strength in tint as a similar product treated with all of the phthalimidomethylquinacridone added in the extraction step only.

The "two-tone" nature of the product with its small particle size gives it a more metallic finish, making it highly valued for automotive finishing applications.

Examples Examples of the present invention have remarkable rheological properties,
1 illustrates the production of a 2,9-dichlorocyclidone solid solution pigment.

Three laboratory-scale mills with a diameter of 1.27 cm (1/2
1500 parts of steel balls (inch), 150 parts of roofing needles, coarse 2.9
- Charge 37.5 parts of dichloroquinacridone, 12.5 parts of crude gamma-quinacridone, and 5 parts of anhydrous sodium sulfate. The mill is run for 96 hours at approximately 75% of critical speed. The steel balls and needles are removed through a sieve and the dry ground powder is recovered. A separate laboratory scale mill is charged with 4800 parts of 3.2 mm (1/8 inch) diameter steel shot, 120 parts of the above ground powder, and 790 parts of acetone. The mill is run for 72 hours at approximately 75% of its critical speed.
Remove the contents of the mill onto a sieve to remove the steel pellets.
Acetone is added to clean the steel shot and capture essentially all the pigment slurry from the mill. temperature
Steam is passed through the slurry until it reaches 95°C. After holding the temperature at 95°C for 10 minutes, the acetone is completely removed and the steam is turned off. Cool the slurry to 85°C, add 261 parts of 33% sulfuric acid aqueous solution and 24 parts of alum.
and heat the slurry at 80-85°C for half an hour. It is then treated with an aqueous slurry containing 5 parts of quinacridone monosulfonic acid for half an hour to precipitate 4.7% aluminum quinacridone sulfonate onto the surface of the pigment. Continue heating at 80-85°C for another half hour. The product is isolated by filtration and washed with hot water until acid free. Recover 130 parts of pigment.

Although the particle size of this product is slightly larger than the commercially available counterpart, its rheological properties are better than expected. The product is particularly suitable for high solids paint systems and exhibits extremely attractive rheological properties.
When tested as a compound base for automotive high solids, thermoset paints, this compound base material showed a 4.3 times greater reduction in viscosity compared to a smaller particle size product with a wider particle size distribution. show.
This advantage is particularly important in styling solid reds for automotive topcoats.

EXAMPLE This example describes another method for obtaining aggregated low crystallinity quinacridone prior to milling with an organic liquid.

Add 37.5 parts of crude 2,9-dichloroquinacridone and 12.5 parts of crude quinacridone to 552 parts of concentrated sulfuric acid with stirring at a temperature below 30°C.As this material did not go into solution, add 184 parts of 100% sulfuric acid. Add while keeping the temperature below 30°C. After stirring for 15 minutes, all materials went into solution. The resulting solution is 2000
of water and ice over a period of 1.5 hours with stirring, during which time the resulting slurry was maintained at 0-10°C. The product was isolated by filtration, washed with water until acid free, and dried. Obtain 48.5 parts of dry product.

When this product is ball milled in acetone essentially as in the example, the product obtained is virtually equivalent to that obtained in the example; The coloring strength was weaker and less clear than the product.

EXAMPLE This example illustrates the effect of 2-phthalimidomethylquinacridone on the particle size of the products described in the example.

Dry grinding is carried out exactly as described in the examples.

The resulting ground powder is ground in acetone in the presence of 2-phthalimidomethylquinacridone as follows.

3.2 mm (1/8 inch) steel balls in a laboratory-scale mill
600 parts, 13.2 parts of the pulverized powder of the example, 0.24 parts of 2-phthalimidomethylquinacridone, and 79 parts of acetone. The mill is run for 72 hours at a speed of approximately 75% of its critical speed. The acetone is distilled off with steam and the product is extracted with dilute aqueous sulfuric acid and treated with 4.3% aluminum quinacridone sulfonate as described in the examples. 12 parts of pigment are recovered. Comparing the degree of reduction with the example product in the lithographic varnish, the masstone is clearly darker and therefore has a smaller particle size, but the color strength is comparable to the example product.

Example This example describes the production of a 2,9-dimethylquinacridone solid solution pigment.

1500 parts of 1/2 inch diameter steel balls, 150 parts of roofing nails, 37.5 g of crude gamma-quinacridone, and crude 2,9-dimethylquinacridone in a laboratory scale mill.
Charge 12.8 parts and 5 parts of anhydrous sodium sulfate. This last is added as an explosion suppressant in ground powder, but can be omitted when working on a laboratory scale. mill about 75% of its critical speed
Rotate at a speed of 96 hours. Separate the steel balls and nails with a sieve and collect the dry crushed powder.

600 parts of 3.2 mm (1/8 inch) diameter steel shot in a laboratory scale ball mill with the ground powder described above.
Charge 13.2 parts and 79 parts of acetone. The mill is run at approximately 75% of critical speed for 72 hours. The contents of the mill are taken out onto a sieve to separate the steel shot. The steel shot is cleaned with acetone to collect essentially all the pigment slurry from the mill. Pass steam through the slurry to reach a temperature of 95°C. Temperature to 95℃
After keeping for 10 minutes, the acetone is completely removed and the water vapor is stopped. The slurry is cooled to 85°C, acidified with 26.1 parts of a 33% aqueous sulfuric acid solution, held at about 85°C for 1 hour, and the product is isolated by filtration, followed by washing with water and drying.

The product is a complete solid with a relatively large particle size and exhibits significant thermal stability in high density polyethylene, significantly more thermally stable than a product of the same composition but produced using a dispersion milling technique. Highly sexual. The dispersion-pulverized product clearly shows a blue color change at 260°C (500°), but the product of this example shows better thermal stability at 316°C (600°).

Example In this example, the particle size was determined when 2-phthalimidomethyquinacridone was introduced into the grinding operation in acetone during the production of a solid solution of quinacridone-based 2,9-dichloroquinacridone. Show the effect of changing.

1500 parts 1/2 inch diameter steel balls, 150 parts roofing nails, 37.5 parts crude gamma-quinacridone, and 2,9-dichloroquinacridone crude in a laboratory-scale mill.
Charge 12.5 parts and 5 parts of anhydrous sodium sulfate. The mill is run for 96 hours at a speed of approximately 75% of its critical speed. Separate the steel balls and nails with a sieve and collect the dry crushed powder.

A laboratory-scale ball mill with a diameter of 3.2 mm (1/8
600 parts of steel shot (inch), crushed powder of the above 13.2
79 parts of acetone and 0.48 parts of 2-phthalimidomethylquinacridone in the first and second
Prepare 0.24 parts. The mill is run for 72 hours at a speed of approximately 75% of its critical speed. The contents of the mill are taken out onto a sieve to separate out the steel shot. The steel shot is washed with acetone to collect essentially all the pigment slurry from the mill. Steam is passed through the slurry to reach a temperature of 95°C. Holding the temperature at 95°C for 10 minutes will remove all the acetone and stop the steam. The slurry is cooled to 85°C, acidified with 26.1 parts of a 33% aqueous sulfuric acid solution, and kept at 85°C for 1 hour. It is then treated with an aqueous slurry containing 0.5 parts of quinacridone monosulfonic acid for half an hour to precipitate 4.3% aluminum quinacridone sulfonate on the surface of the pigment. 80-85
Continue heating at ℃ for another half hour. The product is isolated by filtration, washed acid-free with hot water and dried.

The resulting product containing 4% 2-phthalimidomethylquinacridone has a significantly smaller particle size than the product containing 2% 2-phthalimidomethylquinacridone. Their color strength in thermoset acrylic paints is essentially the same, but they differ in their "two-tone" effect in metallic finishes, with products containing 4% 2-phthalimidomethylquinacridone "Two-tone" exhibits a larger and therefore more attractive appearance. Furthermore, this latter product exhibits substantially better rheological properties in thermoset coating systems when compared to commercially available products of similar color and "two-tone" effect.

EXAMPLE This example describes curing to change particle size by introducing 2-phthalimidomethylquinacridone during the milling operation in acetone during the preparation of a solid solution of quinacridone 2,9-dimethylquinacridone.

Dry pre-milling is carried out as reported in the examples, but in the one case 2% of 2-phthalimidomethylquinacridone, based on the charge pigment, and in the other case 4% of its additives, in acetone. Add to the grinding process. All other steps are carried out as described in the examples, but with additions of approximately 4.3%
of aluminum quinacridone sulfonate precipitates on the pigment surface.

The resulting product containing 4% additives is
The particle size is significantly smaller than the product with 2% additive, and the latter has a smaller particle size than the product without additive. As lithographic varnishes or thermoset acrylic paints, their strength is essentially the same, but the color tone in bulk is different. The darker the mass tone, the more desirable the product is for use in metal-like automotive finishes.

Example In this example, two
-Explain the effects of phthalimidomethylquinacridone. The dry milling is carried out as reported in the examples, except that 1.5 parts of 2-phthalimidomethylquinacridone in addition to other ingredients are also charged into the mill followed by dry milling.The finish and surface treatment are exactly the same as reported in the examples. It is. This product is essentially the same as the product prepared in the Examples containing 4% 2-phthalimidomethylquinacridone.

EXAMPLE This example describes the production of a golden solid solution pigment consisting primarily of quinacridonequinone.

Using the mill and grinding media of the example, 43.7 parts of quinacridonequinone, 6.3 parts of anilinoacridone,
Grind 0.1 part of quinacridone and 5 parts of anhydrous sodium sulfate. Conditions are as reported in the Examples. The resulting ground powder is ground in acetone and purified as reported in the examples, but the resulting product is kept as a pressed mass and then the salt is precipitated on top of the pigment dispersed in water. Increase the volume with 5% basic nickel carbonate. The resulting solid solution product was golden in color and was subjected to high turbulence acid drowning as described in U.S. Patent Application No. 153,208, filed May 27, 1980.
It is very compatible with automotive acrylic paints made from the same ingredients.

Example XI This example describes the preparation of an orange solid solution quinacridone pigment.

Using the mill and grinding operations described in the examples,
21 parts of γ-quinacridone, 14.5 parts of 4,11-dichloroquinacridone, 9.5 parts of quinacridonequinone, 6,
5.0 parts of 13-dihydroquinacridone and 5 parts of anhydrous sodium sulfate are mixed and ground. The dry grinding conditions used were as reported in the Examples. The resulting pulverized powder is pulverized in acetone and purified by the method shown in the example with the addition of treatment with aluminum quinacridonesulfonic acid.

Although this product is comparable in X-ray diagram and color to commercial grade products of similar composition, the masstone is lighter in color as a result of the larger particle size.

Inclusion of 3% 2-phthalimidomethylquinacridone on a total pigment basis in the milling process in acetone closely approximates commercial grade products in masstone depth, but in thermosetting acrylic paints. A product is obtained which exhibits an improved viscosity after dispersion.

Example XII This example illustrates the effect of changing the properties of the organic liquid on a 40/60 2,9-dimethylquinacridone/quinacridone solid solution pigment.

Using the mill and grinding operations described in the examples,
30 parts of crude γ-quinacridone, 20 parts of crude 2,9-dimethylquinacridone, and 5 parts of anhydrous sodium sulfate.
The resulting ground powder is divided into three parts and ground in an organic liquid as described in the separate examples. The first implementation (a) uses acetone as the organic liquid, the second implementation (b) uses methanol as the organic liquid, and the third implementation (c) uses isopropanol as the organic liquid. Purification and surface treatment were as described in the Examples. The resulting products have different particle sizes, with (c) being the smallest particle size;
Therefore, it is the darkest color and mass tone is the most transparent. Product (b) has intermediate particle size and product (a)
has the largest grain size and is the lightest color, while masstone is the most opaque. In terms of color, all three products are substantially the same. Therefore, products with different particle sizes can be made by varying the organic liquid in the second milling step.

EXAMPLE This example illustrates the effect of water used in combination with a water-miscible organic liquid on the particle size of the product described in Example XII.

Using the ground powder produced in the dry grinding step of Example XII, (d) 100% acetone (e) 78.5% acetone + 21.5% water (f) 50% acetone + 50% water (g) 100% isopropanol (h) Grinding in an organic liquid is carried out according to the procedure of the example using 50% isopropanol + 50% water.

Purification and surface treatment were as described in the Examples.

The resulting pigment was tested by rubbing in lithographic varnish and is very similar to what can be expected in some automotive finishes. Regarding masstone, product (e) is slightly darker and more transparent than product (d), and product (f) is slightly darker than products (e) or (d). Product (h) is slightly darker than products (f) and (g). In this way, particle size control can be achieved during the milling step in an organic liquid by diluting the organic liquid with water.

EXAMPLE This example describes the preparation of pigmentary unsubstituted quinacridones.

Using the mill and grinding media of the example, (l) 50 parts of γ-quinacridone and (m) 50 parts of β-quinacridone are both dry milled for 96 hours.

The ground powder thus produced is ground with an organic liquid by the operations described in the examples and purified as reported in the same examples.

(n) (comparative product) 13.2 parts (l) (o) 13.2 parts (l) + 2% phthalimidomethylquinacridone (p) 13.2 parts (l) + 4% phthalimidomethylquinacridone (q) (comparative product) 13.2 parts (m) (r) 13.2 parts (m) + 2% phthalimidomethylquinacridone (s) 13.2 parts (m) + 4% phthalimidomethylquinacridone Products (n), (o) and (p) are α - Quinacridone.

When tested by friction in lithographic ink, the product
(n) exhibits very light masstones and weak tones. Product (o) is darker in mass tone;
In this respect, it is on the same level as pigment products. Product (q) is darker in mass tone than product (o).

Products (q), (r) and (s) are β-quinacridone with some α-quinacridone. Product (q) is very light in mass tone and has a weak tone. Product (r) is substantially more intense in tone and darker in mass tone, comparable to the commercial product. Product (s) is darker in mass tone than product (r) of comparable color strength, but the bulk crystallography of α-quinacridone is slightly yellow due to impurities.

Claims (1)

[Claims] 1 formula or quinacridone, or mixtures thereof, and formulas containing from 0 to 75% by weight and up to 15% by weight of unsubstituted quinacridone quinacridone, in which R ¹ ,
R ² is fluorine, chlorine, bromine, methyl or methoxy; R ³ , R ⁴ , R ⁵ and R ⁶ are hydrogen, fluorine, chlorine, bromine, methyl or methoxy; R ⁷ , R ⁹ and R ¹⁰ is hydrogen or chlorine; and R ⁸ is hydrogen, chlorine, bromine, nitro, 1
From a crude quinacridone consisting essentially of an alkyl group of ~5 carbon atoms, an alkoxy group of 1 to 2 carbon atoms, or a benzoylamino; and m is an integer from 1 to 4; ) The crude quinacridone is milled in a milling device that provides shear and friction, or the crude quinacridone is dissolved in concentrated sulfuric acid, the solution is drowned in a large volume of cold water, and the product is Separate and
After converting the crude quinacridone to an aggregate form of low crystallinity, (b) treating the resulting quinacridone with an alcohol, ketone, hydrocarbon, or halogenated hydrocarbon effective to improve the crystallinity of the quinacridone particles; A process for producing pigmentary quality quinacridone by grinding in some water-miscible organic liquid and then recovering the pigmentary product. 2. The method according to claim 1, wherein the grinding device is a ball mill, and the grinding is carried out in a dry state. 3. The method according to claim 1, comprising:
A method in which the liquid is a lower alcohol or ketone containing up to an equal amount of water. 4. A method according to claim 3, comprising:
The method wherein the organic liquid is acetone. 5. The method according to claim 4, comprising:
A method in which the quinacridone is 2,9-dimethylquinacridone and up to 5% by weight of phthalimidomethylquinacridone. 6. The method according to claim 4, comprising:
A method wherein said quinacridone consists essentially of 2,9-dimethylquinacridone containing up to 5% by weight of phthalimidomethylquinacridone. 7. The method according to claim 4, comprising:
A method wherein the quinacridone is a solid solution consisting essentially of 2,9-dichloroquinacridone, quinacridone and up to 5% by weight of phthalimidomethylquinacridone. 8. The method according to claim 4, comprising:
A method wherein the quinacridone is a solid solution consisting essentially of 2,9-dimethylquinacridone, quinacridone and up to 5% by weight of phthalimidomethylquinacridone. 9. The method according to claim 4, comprising:
A method wherein the quinacridone is a solid solution consisting essentially of quinacridone, dihydroquinacridone, 4,11-dichloroquinacridone, and quinacridonequinone. 10. The method of claim 4, wherein the quinacridone is a solid solution consisting essentially of quinacridonequinone and anilinoacridone.