SU1368663A1 - Method of determining coating ability of pigmented materials - Google Patents

Abstract

The invention relates to non-destructive methods of quality control of materials, in particular to colorimetry, and can be used in the manufacture and use of various pigments and pigmented materials. The purpose of the invention is to reduce the number of: trial; paints while improving the accuracy of determining the covering power of pigments. To do this, the OT-I reflective coefffindants of the convoluted and / or liquid film of an unpainted substrate and stained with a known amount of pigment of one susbstrate film on two different substrates measured at several wavelengths are known, and the optical absorption constants and the scattering of the light of the substrate and pigment according to the equation, then according to this equation, select such a thickness of the substrate layer or the concentration of pigment in the substrate, at which the color difference is pigmented A bath material on an ideally black substrate would constitute one conventional unit in the color space of the MKO 1976. 1 tab. (L CO O5 00 O5 O5 CO

Description

one

The invention relates to non-destructive methods of quality control of materials, in particular to colorimetry, and can be used in the production and application of various pigments and pigmented materials: paints, enamels, artificial leather, polymer films, etc.

The purpose of the invention is to reduce the labor intensity by reducing the number of openings of paints while at the same time improving the accuracy of determining the covering power of pigments.

686632

The method is carried out as follows.

Measured at several wavelengths. The reflection coefficients of two different substrates. Then at the same wavelengths - the reflection coefficients on these substrates of one liquid or hardened paint of pigmented material with a known pigment content. The optical constants of absorption and scattering of the light of the pigmented material are determined by the following expressions for each wavelength:

R -n-U l ilinjra-bctMbSl}. .

  a (m, k + l) - (m, + k) + b (l-m, k) cth (bSl).

R (, i,) 2 iZStIS I.bcthibSllJ

  a (mik-H) - (m ,, + k) + b (l-mjk) cth (bSl) L

where R, and R, are the reflection coefficients of the pigmented material at a given wavelength, on the first and second substrates, respectively,

k (- g) is the Fresnel coefficient;

n is the refractive index of the substrate of the pigmented material;

t, k + (l-k) Rn,;

m.

 k + (l-k) R

ni

hi ni, the reflection coefficients of the first and second substrates, respectively, at a given wavelength;

b (a -1) and K / S + 1;

K, S are the optical constants of the absorption and scattering of light of the pigmented material, respectively, at a given wavelength; 1 is the coating thickness of the pigmented material,

then, using expressions (1) and (2), setting RHI 1.0 at all wavelengths (perfectly white substrate) and, 0 at all wavelengths (ideally black substrate), select the coating thickness of the pigmented material 1, at which it color difference on such substrates is 1 conventional units.

five

Example 1. There are six pigments of different colors, a polyurethane-5 new (PU) solution with a refractive index of 1.5 and two different substrates.

The reflection coefficients R and R „of the substrates are measured at 16 wavelengths 0 in the range of 400-700 nm through 20 nm.

 For each pigment, a PU film is prepared, which is colored with a pigment according to the recipe, wt.

PU solution 100 Pigment0,1

The thickness of the dried films (temperature for 3 hours) of the colored solutions, 25 mm. Films are measured at the same wavelengths on two 0 substrates.

For each pigment at each wavelength from equation (1) and (2), the optical absorption and scattering constants of the pigmented material are found:

K (a-l) -S; (3)

S arccth (A / b), ()

b (a - 1); (5) 0 YiXi - YiX ,.

 x; FG-x, F,

AF, - Yi

x

X, (l-k), - R, (l-m, k); (8).

5 Xi (l-k) rai - RZ (l-mjk); (9)

Y, R, (m, + k) + (l-k); (10)

Y, R, (m, + k) + (l-k); (11)

Ф, R, (pl., K + l) + (l-k) m,; (12)

(m5k -fO + d-k) m, j; (13)

A

(6) (7)

m, k + (1) К „,; m, k + (1-К) К „,,

where R pg is the reflection coefficient

the first and second subclauses, respectively;

R ilill ik lJ a; bcth bSll f a (l + k-k + k3) - (l + k2) + b (l-k + k k) cth (bSl)

a equation (2) for ideally black,

R ", 0:

R IlkUlbcthibslll,

 a (l + k) -2k + b (l-k) cth (bsl)

where R g and R are calculated film coefficients on perfectly white and ideally black substrates, respectively.

Varying the value of 1, find, according to (16) and (17), such R, so that the color difference between them is according to the formula for bd 1976. there would be 1 usd.

According to the obtained 1, the covering ability (consumption) of the pigmented material (pigment) is found:

B., (, S,

where p is the density of pigmented

material, c - pigment concentration,%.

EXAMPLE 2. Same as prior 1, however, the colored films are not dried before measurement and their thickness 1 is 1 mm.

EXAMPLE 3. Same as example 1, however, one film of dried unpainted PU solution is additionally prepared, with a thickness of 0.25 mm. The film is measured at the same wavelength on two substrates.

For the substrate (PU), at each wavelength from equations (1) and (2), optical constants and g of absorption and scattering of light are found:

/ 5 (a - 1) - g; (19)

rrr arccth (A / b),

(20)

where the values of A, B, and a are determined by formulas (5) - (15) and in this case R, and R, 2 are the reflection coefficients of the substrate film on the first and second substrates, respectively.

The optical absorption and scattering constants of each pigment at each wavelength are found:

R, R are the reflection coefficients, and no film on the first and second substrates, respectively.

Write equation (I) for an ideally white substrate, R, l:

d

 K -).

;, S)

(21) (22)

0

o

five

about

five

five

0

g

Then, using equations (16) and (17), we learn that

K o / C + / 5 (1-C);, (23)

S (C + g (1st), (24)

find such a concentration of pigment C, so that the color difference between R .. and R would be 1 conventional units.

about l

Example4. Same as example 3, however, the PU film of the solution with a thickness of 1 I mm is not dried.

The obtained D values for six pigments are shown in the table.

As can be seen from the table, the obtained values of the covering power of the pigments do not depend on the state of the substrate.

Claims (1)

Invention Formula A method for determining the covering power of pigmented materials, including making test stacks of pigmented material, measuring their reflection coefficients at different wavelengths on two different substrates, and determining the consumption of pigmented material corresponding to the color difference of the coating of this pigmented material on these substrates in 1 used units. in the color space L 1976, characterized in that, in order to reduce labor intensity by reducing the number of paints, while improving the accuracy of determining the covering power of the pigmented material, the reflectances of the substrates are measured at various wavelengths, then The reflection coefficients on these substrates are single pigmented. 513686636 optical material with a known pigmented material content by the pigment, the optical expressions (1) and (2) are determined for each absorption constant and the scatter of the wavelength ., .., v5 l-mj, a-bcth bSlp   a (m, k + Tb (m, Tk) + b (T m7kJcth (bSlT p "n-k iZSlLSlbcth bSliJ oN    a (m, k-H) - (m, + k) + b () ctMbSr) where R and RJ are the reflection coefficients of the pigmented material at a given wavelength, on the first and second substrates, respectively; 10 I 15 k (-77) is the Fresnel coefficient;  n + b (a -) "; and K / S + 1; K, S - optical constants respectively, the absorption and scattering of the light of the pigmented material at a given wavelength; 1 is the coating thickness of the pigmented material, then, by expressions (1) and (2), set, k + (1 - k) Kn; nov R,; i 1.0 at all wavelengths and mk + (1 - k) Rf, j; RP 0.0 and at all wavelengths, selects P1 n reflection coefficients 25 of the thickness of the pigmented coating of the first and second base material 1, at which its color corresponds to the color difference on such wavelength substrates; is 1 unit n is the indicator of the protrusion of the substrate of the pigmented: - ivanny material; 20 Titanium dioxide, thyl Bb1neral rich red 5LGG Paliogen red 3910 Paliogen red 4470 Heliogen blue 7080 Heliogen green 8720 VNIIPI Order 279/40 Random polygons pr-tie, Uzhgorod, st. Project, 4 10 I 39.5 53,8 68.5 44.1 115.3 78.0 38,2638.25 52,8.452,86 67.9567.94 42.1542.17 111,73111,75 77.4877.47 Circulation 499 Subscription