CS204497B1 - Method of spectrophotometric evaluation of phthalocyanine pigments in aqueous dispersion - Google Patents

Description

The invention relates to the evaluation and malting of color properties, in particular - expressed in color terms - by the clays, purity and color tone of phthalocyanine pigments in dispersions stabilized by dispersants. It consists in a process for preparing a stabilized dispersion in a form suitable for spectrophotometric measurement and in the subsequent objective evaluation of the pigment content and its color in the dispersion. The process is suitable for phthaloyanine pigments, raw, purified and for their commercial whiskers.

Research into phthalocyanine pigments in terms of synthesis, purification and conversion to commercial forms of desired application properties requires appropriate methods to allow the evaluation of the various synthesis, purification and finishing processes not only quantitatively but also qualitatively, especially with respect to color properties .

A non-metallic phthalocyanine of the formula CgHggNg, the metallic phthaloyanines derived therefrom of the formula CggHggNgMe, wherein Me is Cu, Ni, Fa, Co, Cr or other metal, and also phthalocyanine derivatives in which there are 1 to 16 hydrogen atoms by halogen (Cl or Br), always containing more or less impurities and by-products of synthesis or finishing.

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The impurity and impurities in the starting phthalocyanines affect the purity and color tone of the phthaloyanine pigments, impairing their coloristic properties and further processability. For example, iron phthalooyanine in copper phthalocyaninh shifts the hue to red and cloudy. Halogenation of phthalocyanine molecules causes shifts in purity and tone, for example, in phthalocyanines with the medium (blue) to blue-green to yellow-green shades depending on the number of atoms and type of halogen. The color tone of the pigment can also be influenced by the crystalline modification and particle size.

So far, the control of crude or purified phthalocyanines has focused only on the determination of phthalocyanine content or impurities, usually by conventional analytical methods, which either do not at all or only inadequately reflect the color properties. Even the quantitative results of these methods are not always reliable and depend to a large extent on the impurity content. Impurities can affect the determination of phthalocyanine content in a variety of ways.

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In the gravimetric determination by precipitation from a solution in sulfuric acid or by successive extraction with dilute acids, bases and organic solvents, some of the impurities remain undissolved and increase the content determined. The same is true, for example, in oxgdimetric assays (eerlmetriques, bichrematoaetrically), the errors are burdened by the tennogravimetric assays of phthalooyanim and the substances contained therein.

In the spectrophotometric determination of the sulfuric acid solutions used to date, phthalooyanine provides blue, yellow and green purplish solutions. Therefore, it is not possible to draw conclusions about the color of pigments from the color of the sulfuric acid solutions, since they are diametrically different. Some impurities dissolve in yellow-brown sulfuric acid and again affect the determination of the content similarly to other methods.

After the final treatment of the phthaloeyanin pigments, the evaluation of the phthaleyanin has a completely different character. With respect to the color properties, the coloristic evaluation is carried out by the methods used for pigments, while it is known that the original properties of phthalocyanines are largely deliberately influenced by the final treatment, which changes, for example, crystalline modification, particle size, etc. pigments applicable.

Until now, the overall evaluation of phthalnoyanine pigments has been possible by combining the content determination with one of these methods, monitoring the quantity and quality of impurities by other physico-haemoclimate methods (eg extract chromatography) and colorist evaluation in application form (oil coatings, PVC foils, printing etc.) power, tone and purity. Deficiencies of individual procedures and their combinations, their complexity and time demands are evident from the above.

This disadvantage eliminates and new possibilities for evaluating and monitoring color properties provide a method of sphtophotometric evaluation of phthalocyanine pigments in aqueous dispersion, wherein ee by introducing a solution of phthalocyanines in 90-100% sulfuric acid with a pigment concentration of 0.2-1.00 g / l into aqueous 1 to 3% of a dispersant solution, in particular a non-ionic solution.

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Au ”Αγ“ Δφ ( ² )

By multiplying this difference A _{D by the} transformation matrix W, vector B is calculated

B »W. A _q (2) whose individual elements allow to evaluate the difference between a sample and a type in three components · For example, the CIE space 1976, where the individual elements of vector A are defined as a color space

Α _χ »116 f ₂ and ₂ - 500 (f _x - ø ₂ ) and ₃ = 200 (ø ₂ - f ₃ ) where f ^ for i - 1, 2, 3 .... is defined

-> 8,856.10 ^-3

L

8.856.10 ^-3 (4) (5)

(6) (7) where T _ol are the trichromatic components of the contractual light in question and is an element of vector_T defined by (8) where P is a matrix of products of trichomatics and relative spectral composition for the selected contract light and selected wavelengths.

Similarly, the ANLAB color astronomer can be used, where vector A is defined

A = 'U. M (9) *

where the matrix U has elements

9.2 0 40 -40 0

16 -16

1, 2, 3, of vector M are approximated and elements i

^k i ^{2 T} i ⁺

204 497 q ₃ - 3,85238 q ₄ - -1,08541 vector T is defined by equation (8) and vector Τ _θ contains the trichroaatic components of contract light.

According to equations (3) to (8) for the CIE space 1976 or equations (9), (10) and (8) for the ANLAB space, the vector Ay and A _T is calculated.

For example, the matrix W can be selected as a diagonal matrix with unit elements.

In this case, the color difference in the components of the 1976 CIS pro rata or the ANLAB nspace is obtained from equation (2). If a color difference evaluation χ is required for terms close to the visual evaluation of force, purity and color tone ^, it is appropriate to base the matrix W on the assumption that the force axis has a slope given by the vector derivative intersects the CIE 1976 color space brightness axis, the color tan axis is perpendicular to both previous axes, with the center of the new system at the point of type. In this case, the individual elements of the matrix ff are calculated from the vector A _T and its derivative vector according to the concentration e and Αφ

D - - (11) d c according to equation _____

N ₂ - A, ² + D ² + D ¹

A _{T2 +} A _T3 Dg D ₃ '11. ^ ² -1 ² °. A _g3 D », ^D A

T2

N,

W,

Nff (12) (13) (14) (15) (16) (17) (18) (19)

204 497 '31 ^A T2 ^D 3 - ^A T3 ^D 2 * 1 * 2 ^D , ^(A T2 ^D 2 + ^A T3 ^D 3) * ^A T3 ^D l '(20) (21) ^D 1 * 1 * 2 ^P 2 ^(A T2 ^D 2 * ^A T3 ^P 3) 4- ^A T2 ^D 1 ^D 1 * 1 * 2 (22)

For Equations (12) to (22), the required elements of vector D are calculated according to Equation (11) from Equations (3) to (7) for OIE 1976, or Equations (9) and (10) for ANIAB, and equation (8) and from the Lambert-Beer law ejcp (-Ej c ln 10), J = 1,2 .... n (23) where is absorbptleate.

Use) »Flying W as defined in equations (12) to (22) in equation (2) yields an age t and r / b whose elements correspond to the visual color evaluation in order of purity, strength, color tone, and these values are in metric of the selected color space.

Calculation of the force in the usual expression as a hundred times the ratio of the number of parts of the sample to the number of parts of the type needed to obtain the perception of the same force Bg shall be performed according to

where Cy is the sample concentration, c _T is the type concentration and Bg is the element of vector B calculated from equation (2).

In order to further elucidate the invention, the following examples are provided:

Color variations - strength (content), purity and tone due to the addition of iron phthalocyanine in copper phthalocyanine are given in Example 2. Example 3 shows the variations in strength, purity and tone in the sequential chlorination of copper phthalocyanine.

Example 1

Weigh 0.050 g of pure nickel phthalooyllau (sample A) was dissolved in a 100 ml volumetric flask in 96% sulfuric acid, made up to volume with sulfuric acid after dissolution and tempering. Two ml of the solution was dropped from the burette into 30 ml of a 1% aqueous solution of a non-ionic dispersant presented in a 50 ml volumetric flask, allowed to equilibrate and supplemented with a diepergator solution. Crude nickel phthalocyanine dispersions were also prepared (samples B and C, estimated to be about 70 $>} from 0.070 g batches. The obtained phthalocyanine concentration dispersions, nickel about 0.020 g / l, were measured in 1 cm glass cells in the 400 to 70 range. From the values calculated on the table calculator trichromatic components and other quantities characterizing the type (A) and samples (B, C) were also prepared in the same way aqueous dispersions of sample A · concentration of 0.005 to 0.020 g / 1 (sample * 1 *

A), determined by absorption at 600 nm and calculated by linear / egression o (g / 1) => 0.019667 · AgOo

In which c is the concentration of nickel phthalocyanine X g / Ι »Ag _0Q is absorbanoe at 600 n« in 1 cm of rock. 24 The continuity is strictly linear at a regression coefficient R »0.9996. The nickel phthalocyanine content according to said linear regression was 65.8% for sample B and 64.4% for sample C.

For aqueous dispersions of samples B and C, strength (% content), purity deviation were calculated

(R) and tone (T) against the selected type A. Sample % power / 100 R T AND 100 ALIGN! 100 ALIGN! 0 0 (B) 62.5 159.9 - 2,00 - 5,64 C 60.7 164.8 - 2,63 - 6.39

In addition to the lower content of nickel phthalocyanine, the impurities in the synthesis resulted in turbidity (Oversea R) and a shift in the tone of the diisperation to green (negative T - CIS 1976). The difference in the determination of nickel phthalocyanine content at one wavelength (600 na) and from the objective evaluation, which includes the visible spectrum ^, is due to the presence of impurities in crude products B and C.

EXAMPLE 2 Weighed about 0.050 g of purified copper phthalocyanine (sample D), a stabilized aqueous dispersion having a concentration of about 0.010 g / l was prepared by the procedure of Example 1, measured in absorbances in the range of 400 to 700 nm (10 mra) and calculated. and T using a commercial copper phthalocyanine dispersion X-modification as type. A dispersion of 5% iron phthalocyanine-modified sample was prepared and processed (sample E).

Sample «5 strong type 100 ALIGN! 100 ALIGN! D 102.3 97.7 E 96.1 104.1

R T 0 0 0.06 - 0,32 0.46 + 1,35

The presence of iron phthalocyanine in copper phthalocyanine resulted in a marked shift in purity and dispersion tone (sample E hardened, redder, ie negative R and positive T - according to CIE 1976).

Example 3

Chlorine content was determined in copper phthalocyanine samples during chlorination. Solutions in 100% sulfuric acid with pigment concentrations of about 1.0 g / l were prepared, and dispersions of 0.050 g / l were prepared by introducing measured volumes of a 2% aqueous solution of a non-ionic dlspergate. The absorbance was measured by the dispersion in the eWr of 4 - 700nm (10 nm increments), the absorbance calculated for the force, the deviation of the purity (R) and the decay (T) of the counter-type of chlorinated copper phthalocyanine.

204 497 Sample % strong 47/1 110.3 90.7 47/2 106.6 93.8 47/3 106.0 94.3 47/5 104.1 96.1

R T % Cl - 3,26 13.65 39.4 - 0,73 6.16 45.5 - 0,13 2.42 46.8 0.51 - 0,09 47.7

In the course of chlorine, the purity of the pigment dispersion increases (R and positive values) and the tone deviation from the type decreases (sample 47/1 becomes opaque, bluer).

Claims (4)

SUBJECT OF THE INVENTION The method of spectrophotometric evaluation of phthalocyanine pigments in an aqueous dispersion prepared by introducing pigments solutions in concentrated 90-100% sulfuric acid into a dilute aqueous solution of a dlspergate, in particular non-ionic, by measuring the spectrum in the visible range, calculate only the pigment content on the basis of the validity of the Lnmbert-Beer law, then the trm-chromatic components T are calculated from the measured transmittances over the whole spectrum, and the vectors of Ay and A type samples in the selected color space are calculated. pattern and type A® “Ay” Αφ (1) and multiply by the regular matrix W ae multiplied by vector B B - WA _D. (2) whose components are three distinct characteristics of the difference between the sample and the type, Method according to claim 1, characterized in that the matrix V is selected as diagonal and unitary elements and the components of vector B calculated according to equation (2) correspond to the decomposition of the difference between the sample and the type into the principal axes of the selected color space. 3. The method of claim 1 wherein the matrix W is selected such that the force axis has a slope equal to the derivative of vector A ^ at the point of type, the axis of purity is perpendicular thereto and intersects the axis of brightness and the axis of color axis and perpendicular axes intersect at a point type, wherein the calculating the derivative _T a vector according to the concentration is used the Lambert-Beer law r ^ exp (-E j β 1 »10), j - 1,2 .... n ( 23), where r ^ is the measured traneaitanee, Ej absorptivity, c condensation, n the number of wavelengths as well as the wavelength index and the components of vector B, calculated according to equation (2), correspond to their meanings 4. Method according to claim 1, characterized in that from the value of the element B ^ of the vector B corresponding to the force, the force of the sample Β ^ * ν is calculated by the usual number of parts of the sample ^ 204 497 correspond to 100 parts of the type in order to obtain the same yield, according to the equation where Dj, Dg, D ^ are derivatives of the individual elements of the type vector in the selected color space according to concentration, the sample concentration and the type concentration.