DD209470A5 - WAESSED PLASTIC DISPERSION COLOR WITH BUNTPIGMENT - Google Patents

Abstract

The invention relates to an aqueous plastic emulsion paint with colored pigment. It has been found that excellent color stability and resistance to discoloration can be obtained by using Manganese (II, III) oxide fume dust as a colored pigment. This pigment is superior to the hitherto conventional synthetic iron oxide pigments, especially in the Faerbtoenen of Beige to reddish brown and dark brown. Mntief 3 Otief 4 smoke dust is obtained as waste product from the exhaust gases of metallurgical furnaces for ferromanganese production.

Description

The invention relates to a paint which is prepared as an aqueous dispersion and contains a new colored pigment. The new colored pigment leads to an increased color stability of the paint.

Characteristic of known technical solutions The known aqueous emulsion paints are prepared by dispersing one or more pigments in water containing additives such as surfactants, stabilizers, dispersants, thickeners and the like. It is then mixed with a film former, such as an emulsion of acrylic polymers or copolymers. The most important requirement for a pigment is that it produce a certain and pleasing color in the paint, alone or together with other pigments. In addition, the pigment must be stable, so that the coloration is maintained for a long time. Another important requirement is a very fine particle size, generally less than ten microns. Due to the fine particle size its dispersibility is favored in the preparation of the paint mixture and the paint can be applied evenly in a thin layer without streaks or other errors occur. The last requirement is particularly important if the emulsion paint is

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Rolling or spraying is applied.

Aim of the invention

It is an object of the invention to provide an improved color pigment for aqueous KunststQff-Uispersipnsfarben. Further, it is an object to provide a dispersion color having good color stability and relatively high resistance to bleaching by exposure to sunlight.

Explanation of the essence of the invention

These problems of improving aqueous emulsion paints are achieved according to the invention by the use of a colored pigment consisting of manganese (II, II) oxide dust (Mn ₃ O ₄ ) or a material containing MngO 2 smoke dust as the principal constituent. The Mn ^ O ^ smoke dust pigment is first dispersed in the water, the wetting agent, dispersants, desliming agents, extenders, stabilizers, glycols and the like. and then pinged into an aqueous acrylic emulsion which may contain acrylic polymers or copolymers. The proportion of Mn.O. smoke dust pigment may be about 5 to 50% by volume of the non-volatile portion of the emulsion paint component system.

The accompanying drawing shows a graphical representation of the particle size distribution for a Mn 0 dust vapor material to be used with preference in accordance with the invention. ,

The Frfindunq is based on the finding that dail · Mn-sO, smoke dust or a material containing predominantly this smoke dust, in finely divided or powdered state, a new and ideal color pigment for

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Represents formulations of a variety of aqueous emulsion paints. The Μη, Ο, smoke dust color pigment is particularly advantageous for applications in which iron oxide pigments have hitherto been used. It became 7.B. also found that finely divided Mn ^ O. Rauchstaub as a colored pigment leads to a dark brown or deep reddish brown color, which is similar, but still slightly different from the brown colorations that are produced by various synthetic iron oxide pigments, for example by yellow, yellowish brown and red iron oxide pigments. It has also been found that ΜηοΟ-smoke dust pigment at high temperatures up to about 600 ⁰ C is resistant, while the usual yellow or yellow-brown iron oxide pigments when heated to about 177 ° C to convert into red iron oxide. The Mn.O. smoke dust color pigments can be prepared in a wide range of particle sizes closely related to the particle size of conventional iron oxide pigments. As mentioned, it is desirable for various reasons that a color pigment be used in very finely divided particles, in particular because of the even distribution in the paint system during its production. In general, the Μη, Ο ,, Rauchstaijb pigment should have a particle size below about 10 microns.

The colored pigment to be used in the present invention is MnoCL smoke or a composition containing a predominant content of Mn.sub.2 O.sub.8 smoke dust, i. greater than about 60% by weight.

The Mn.RTM. Smoke dust to be used in the present invention is easily and favorably obtained by blowing a stream of oxygen through a molten bath of ferromanganese or over the surface thereof. Normally, forromania contained in the blast furnace or in the electrometallurgical furnace and the like. at 1200 ⁰ C or higher temperatures is generated, up to

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6 or more % carbon. The carbon content is usually reduced, eg, down to about 1.5 % , by blowing oxygen or a mixture of oxygen and air into the ferromanganese melt or over the surface thereof. This is done in a separate container containing cfie freshly tapped melt, at 1000 ⁰ C or higher temperatures, preferably at about 1300 ⁰ C or even higher.

A method of reducing the carbon content of molten ferromanganese is described in US Pat. No. 3,305,352 issued 2I February 1967. In this preferred method for obtaining the MnoO * smoke dust to be used in the present invention, the ferromanganese is transferred from the electric furnace in which it was produced to a treatment vessel such as a pan or oven having a temperature of about 1300 ^° C. or higher converted. Slag is preferably removed. Then, oxygen is blown against the surface of the molten bath by any known means. For example, lances may be used that are held about 2.54 cm above the surface and emit one or more streams of oxygen that impact the surface of the molten bath at a pressure of about 7.7 to 10.5 kg / cm. The amount of oxygen used is about 1.8 to 2.3 kg per minute for a melt of 227 kg in a pan of 76.2 cm in height and 50.8 cm in inner diameter. Of course, this process can also be carried out with larger amounts. The resulting exhaust gases contain very finely divided particles of MngO.-smoke dust. These have a spherical shape and can be easily separated with conventional facilities.

The ΜηοΟ, smoke dust to be used according to the invention can be used as a by-product of the process according to US Pat. No. 3,305,352 for reducing the carbon content.

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content of ferromanganese melts. Here, the melt at a temperature of about 1250 ⁰ C is maintained and is reduced, the oxygen is blown in such a manner that on 17OQ ⁰ C, it heats the molten bath before "the carbon content of the melt to 1.5%. The bubbles of the oxygen is - As described in the patent continued until the temperature of the molten bath has reached 1750 ⁰ C. The MngO ^ -Frauchstaub is obtained by conventional methods from the exhaust gas.

The terms Mn ₃ O ₄ smoke dust and manganese (II, III) oxide smoke dust used in this description and claims, respectively, refer to finely divided, spherical particles of smoke dust which is obtained during oxygen blowing of a melt of ferromanganese.

Subsequently, some typical properties of Mn.RTM. Smoke dust obtained as described above are given. The smoke dust consists mainly of Mn ₃ O ₄ . Typical are 90 to 95 and more% by weight. The remainder is a mixture containing calcium oxide, magnesium oxide, potassium oxide, silicon oxide and less than about 1% by weight of free manganese metal.

Chemical analysis (% by weight): 65.27 Mn, 2.03 Fe, 0.029 Al, 0.28 Si, 0.17 C, 0.040 P, 0.045 As, 0.46 Ca, 1. 43 life, 0.072 K , 0.023 Cr, 0.002 Pb.

Bulk density: 0.78 to 3.04 g / cm ³ . Moisture: 0.22% (1 hour at 170 ⁰ C).

Particle size: 98 % below about 10 microns (99 % pass through a 325 mesh Tyler screen).

pH: 9 to 13 (50 % Mn ₃ O ₄ in distilled water). Particle shape: .sphärisch.

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Specific gravity: 4.6 to 4.75 g / cm.

Thermal resistance: No action up to 60O ⁰ C.

Today's coating technology requires the use of very fine particle size color pigments for. Purposes of increasing the coloring effect or opacity, the suspension properties and the even distribution of the pigment in the paint system. It has been found that these conditions are very well met with MngG smoke dust whose particle size is less than 10 microns. In the case of Mn ^ O smoke dust obtained as described above, it may contain about 1.0 to 2.0% of particles larger than about 10 microns. In certain cases, therefore, it may be desirable or necessary to remove these larger particles. For this one can use the usual classification technique or crushing methods, e.g. Ball mills, apply. Fumigant dust, which by classification or milling is brought to a particle size of 99.5% below 10 microns, can be removed by conventional dispersion equipment, e.g. with a Cowless dissolver, easily dispersed in the component mixture. Formulations containing MOgO 2 smoke dust in the range of this particle size can generally be applied to the surfaces to be coated without streaks or other defects.

A typical distribution curve for the particle size of ΜποΟ, smoke dust to be used according to the invention is shown in the drawing. From the curve it is seen that in the case of klassiertem ^ Mn O. flue dust, the mean particle size is about 0.68 \ im.

A typical formulation for disperse dyes composed according to the invention is given below.

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ingredients Wt.% 65 latex 40 12 thickener 0,5 - 2.0 Dispersant / stabilizer 0,2 - 2.0 wetting agent 0,2 - 1.0 defoamers 0.1 - 6.0 coalescent 0,3 - 1.5 preservative 0.1 - 15.0 extender 0,0 - Ingredients. Wt.% 30 MngO ₄ smoke tower 5,0 - 25.0 TiO ₂ ·, 0,0 - 8.0 Antifreeze 0,0: - 10.0 Alkyd resin or vegetable oil 0,0 - Water '^; ·· "':: , -.: -''}'' -, /. U -,' rest

Aqueous dispersion paints according to the invention having a colored pigment in the form of MngO 3 smoke dust can be prepared by customary known methods. For example, First, an aqueous dispersion of the additives such as dispersants, thickeners, protective colloids, defoamers, surfactants, etc. is prepared. Then, the pigment is dispersed with a draw or bulking agent by using a shearing dispersing aggregate such as a Cowles dissolver or a ball mill so that the fine particles of the pigment and filler are brought into a uniform suspension. The dispersion thus prepared is mixed with a latex, a coalescing agent and the remaining components. Then, the physical properties and the color characteristic become

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tested and, if necessary, regulates the surface tension, the pH, the viscosity and the dispersion. Of course, other methods and devices known in the art can be used with equal success.

The latex to be used in the present invention may be an acrylic-based film-forming latex (acrylic polymers or copolymers) common in the paint industry. Typical examples of many commercially available emulsions useful for the purposes of the invention are the latexes Rhoplex'507, Rhoplex MV 9 and Rhoplex MV 23 from Rohm and Haas Co. and UCAR 336, UCAR 515, UCAR 4341 and UCAR 4358 from Union Carbide Corp.

Thickeners and protective colloids are used to achieve the desired consistency and viscosity. Consistency and viscosity should be adjusted so that the paint can be easily applied to the surface to be coated and forms a uniform film in the desired thickness. Protective colloids also include additives which protect against coagulation and extenders in the presence of electrolytes or excessive shear. Thickeners in combination with surfactants keep the pigments in suspension and stabilize the viscosity of the paint. The selection of the particular thickener is dependent on a number of factors, e.g. the type of emulsion, the bulk concentration of the pigment and the coating rheology.

Usable according to the invention are the usual in the paint industry thickeners of the cellulose type or salts of polyacrylic acids. Purpose-

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moderate thickeners are e.g. Salts of polycarboxylic acids, such as Acrysol G-110 from Rohm and Haas Co., or cellulose thickeners, such as QP 4400 from Union Carbide Corp. Other thickeners are Thickener 845, Thickener 4358 and Thickens E 845 from Rohm and Haas Co.

Also useful is a combined dispersing stabilizer agent for the purpose of completely uniform dispersion of the totality of the pigments and other ingredients in the paint mixture. Various anionic, nonionic and polymeric dispersants can be used for this purpose, e.g. Tamol 731 and Tamol 850 from Rohm and Haas Co., further alkylarylphenoxypolyethoxyethanols (Triton X-1.Ö0), alkylaryl ether sulfate (Triton X-301) and alkylaryl polyether alcohol (Triton X-405). (All Triton preparations from Rohm and Haas Co.)

The formulations for emulsion paints according to the invention may also contain various other ingredients which are not commonly used in the paint industry. For example, a defoamer such as Nopco NDW from Nopco Chemical Company. If the formulation contains an alkyd resin, conventional driers may be added, e.g. Cobalt and zirconium driers. As a coalescing agent, 2,2,4-trimethyl-1,3-pentadiol monoisobutyrate (Texanol from Eastman Kodak) can be used. Other known components such as antioxidants, preservatives, antifreeze agents (e.g., ethylene glycol) may be included in the formulation at the discretion of the person skilled in the art.

Experiments have shown that Mn ₃ O ₄ smoke dust can be combined with common pigments such as titanium dioxide (TiO ₂ ) to produce different hues. For example, in a series of experiments Mn-O ^ -

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- ίο -

Smoke dust mixed with different amounts of TiOp. The resulting different shades were found. For comparison, samples were prepared containing as pigment 100 % Mn ₃ O. Rauchstaub or TiOp. It has been found that the film at 100% TiO ₂ (0% Mn ₃ O ₄₎ pure white, at 10% Mn ₃ 0 * -Rauchstaub (90% TIOP) light brown or beige, at 40% Mn ₃ 0 ₄ -Rauchstaub (60 % TiO ₂ ) medium brown and 100 % Mn ₃ O ₄ smoke dust (0 % TiO ₂ ) dark brown or deep reddish brown.

The color of the film can be specified by the method of "Munsell Book of Color" (Munsell Color Company, Baltimore, Maryland). According to this known Munsell system, hue, luminosity and chroma were determined for each film. The results are shown in Table 1, in the column labeled "Munsell No" the first number and letter refers to the hue, the next number to the luminosity and the last number to the saturation.

% TiO ₂

Table 1 Munsell N No. 5 / color definition YR 9th 2.8 Mn ₃ O ₄ smoke dust 5 YR 5.2 0 7.5 YR _Φ 3.4 10 5 40 100

100

From the Munsell No. Table 1 shows that the Mn ₃ O ₄ smoke dust pigment according to the invention exerts a coloring and modifying effect on other pigments, such as TiO ₂ , giving defined hues such as iron oxide yellow, yellow yellow, chrome oxide green, phthalocyanine black and phthalocyanine green.

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1 -

To further illustrate the invention, examples follow.

example 1

An aqueous dispersion paint was prepared using rutile titanium dioxide as a white pigment. First mixed together: 60.0 g rutile titanium dioxide,

70.0 g of thickener (Thichenor 745, Rohm and Haas Co.) as a 20% aqueous solution of pH 9.7,

2.0 g of dispersant / stabilizer (Tamol 850, Rohm and Haas Co.), 10.0 g of alkylacrylphenoxypolyehtoxyethanol (Triton 100, Rohm and Haas Co.), 1.5 g of defoamer (Hevi-Duty AF Agent, Interstab Chemicals Inc.). 2.0 g of polypropylene glycol, 20.0 g of coalescing agent (Butyl Carbitol, Union Carbide Corp.),

2.0 g of 28% ammonium hydroxide and 87.5 g of water.

After thorough mixing, 622 g of latex (UCAR 4358, Union Carbide Corp.) was added.

The paint thus prepared was sprayed on the surface of several test panels. The test panel η consisted of bare aluminum and had the dimensions of about 7.6 × 22.7 cm with a thickness of about 0.25 mm. For curing, the coated test panels were left at room temperature for about one week. Then they were subjected to the exposure test under laboratory conditions with ultraviolet light. For this test, the coated test panels were mounted on racks and exposed continuously to a constant source of ultraviolet light, according to the ASTMG 25-70 Fadeometer Test protocol. The test panels were periodically examined for color stability and discoloration or fading for up to 1000 hours. For the degree of fading became the following

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Rating scale, established:

10 no change

9 very small change

8 ^ slight change

7 medium +

6 medium.

5 medium -

4 slightly bad

3 bad

2 very bad

1 partial failure

0 failure.

The results of the staining test are shown in Table 2. The numerals for Examples 2 to 4 are the rating grades according to the above scale. The TiOp causes a substantially white pigmentation which remains pale even after long exposure to ultraviolet light. For the example with TiO ₂ , therefore, the abbreviation Bl is used instead of a rating note.

Example 2

There was prepared an aqueous dispersion paint from the same components as in Example 1 with the exception that 57.0 g of leached ΜποΟ, smoke dust were used instead of the 60.0 g of TiOp. The leaching of the smoke dust was done by means of hydrochloric acid. Further, in this example, as the thickener, 73.0 g of polycarboxylic acid (Tichener 485, Rohm and Haas Co.) and 480.0 g of latex (UCAR 4358, Union Carbide Corp.) were used in place of 622.0 g of Example 1. The paint was sprayed on test panels as in Example 1 and subjected to the discoloration test.

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worfen. The film had a dark brown or deep reddish brown color. The results are shown in Table 2.

/.

Example 3

To prepare the emulsion paint, rich alkyd resin (Aroplaz 1271, Spencer Kellog Co.) containing cobalt and zirconium driers was dispersed in water. In the dispersion of 350 g of alkyd resin were

4.0 g of cellulose thickener (QP 4400, Union Carbide Corp.), 8.0 g of anionic dispersant (Tolol 850, Rohm and Haas Co.), 5.0 g of alkylaryl ether as nonionic surfactant (Triton CF-10,

Rohm and Haas Co.),

5 defoamers (Hevi-Duty AF Agent) and 20.0 g of ethylene glycol mixed together. Then there were added: 150 g of synthetic red iron oxide, 35.0 g of filler pigment (Mica 325, English Mica Company), 75.0 g of CaCO ₃ , 50.0 g of antirust pigment in the form of a modified barium metaborate

(Busan 11-M-1, Buckman Labs., Inc.).

The dispersion was carried out in a Cowles dissolver. After thorough mixing, 500 g of latex of a styrene-acrylic copolymer (UCAR 4341, Union Carbicle Corp.) and a coalescing agent were added. As in the previous examples, this emulsion paint was sprayed onto bare aluminum test panels in a film thickness of 0.25 mm. The test was carried out as described above, the results are shown in Table 2.

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Example 4

An emulsion paint was prepared from an acrylic emulsion (Rhoplex MV 23, Rohm and Haas Co.) and MngO ₄ smoke dust. The composition was as follows:

59 g of water. . ' ,

25.0 g of 20% polyacrylate thickener (Tickener E 845, Rhohm and Haas Co.), 17.6 g of 40% dispersant (QR 681 40%, Rohm and Haas Co.),

2.0 g wetting agent in the form of ßenzylether of Oktylphenelethyleiioxid-

Adduct (Triton CF-IO, Rohm and Haas CoJ, 28.0 g ethylene glycol, 5.7 g defoamer (Foamester NDW, Diamond Shamrock Co.), 12.0 g zinc oxide pigment (AZO 77, American Zinc Co.), 53, 0 g CaCO ₃ ,

2.1 g of 2-n-octyl-4-isothiozolin-3-one (Skane M-8, Rohm and Haas Co.) as

Bioeid and

151 g Mn, 0 ₄ smoke dust

 After thorough mixing, 667.0 g of acrylic latex (Rhoplex MV 23, Rohm and Haas Co.), 7.0 g of 28% ammonium hydroxide and, as coalescing agent, 5.7 g of 2,2,4-trimethyl-1,3- pentanediol monoisobutyra.t (Texanol, Eastman

Kodak Co.)

mixed. The further treatment and testing took place as in the previous examples. The applied film had a dark brown or deep reddish brown color. There was basically no difference in the color of leached and non-leached MngO ^ smoke dust. The results of the staining test are shown in Table 2.

table

fs)

Example pigment

50

Discoloration test (hours)

100 200 300 400 500 600 750 1000

1 TiO ₂ Smoke, leached bl CVJ dust .Iron-'" 8th 3 red oxide -Smoke- 10 4 Mn ₃ O ₄

dust

Bl Bl Bl Bl Bl Bl Bl

cn ro cn

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The results of the staining test as shown in Table 2 show that aqueous dispersion paints which contain MngO.RTM. Smoke dust as a colored pigment according to the present invention have color stability and discoloration resistance which are familiar to known emulsion paints Color pigments equal and superior in higher or longer use. In particular, it should be noted that the emulsion paints of Examples 2 and 4 containing Mn.O. smoke dust as a colored pigment have only a slight degree of fading, while the dispersion paint of Example 3 with red iron oxide as a pigment shows a much higher degree of fading, namely from the mark 10 after 50 hours exposure time to the mark 3 after 1000 hours. A further comparison shows that the dispersion paint with titanium dioxide as a white pigment already after 50 hours exposure to ultraviolet light has a bleaching. It also shows that the MngO 2 smoke dust pigment can be used in wide variations of color formulations. In the formulations can be used as a variety of components, such as thickeners, dispersants, stabilizers, defoamers, preservatives, preservatives, etc., without showing any adverse effect on BeschicMjng. The test results also show that the formulations with leached MngO 2 smoke dust do not result in such consistent coatings as we do with non-leached MnO 4 smoke dust. On the other hand, however, the use of leached Mn ₃ 0 ₄ smoke dust results in a higher color fastness than the conventional synthetic red iron oxide pigment.

Claims (5)

1 · Aqueous color paint plastic paint with high color stability and resistance to discoloration, in which the main components are an acrylic emulsion, a thickener, a dispersant and a colored pigment, characterized in that in the formulation as a colored pigment finely divided manganese (II, III) oxld smoke dust (Mn ^ O.) Is included. 2. Aqueous dispersion paint according to item 1, characterized by a LinoOz smoke dust pigment having the following properties: '''ΐ'::'\' · '; · ·'';·; .. - ': ' ^{'-':;::: ':} .. · -''' a) a chemical composition with at least about 90% by weight of MhoO ., The remainder containing calcium oxide, magnesium oxide, silicon oxide and less than about 1% by weight free manganese metal,. b) a particle size of 98 % less than about 10 microns. 3 · Y / aqueous emulsion paint according to item 1 or 2, characterized by the following general formula: Plastic latex about 40 to 65 wt.% Thickener about 0.5 to 12% by weight Dispersant about 0.2 to 2.0% by weight surface-active agent about 0.2 to 2.0% by weight Defoamer about 0.1 to 1.0% by weight Coalescent about 0.3 to 6.0% by weight Protective or preservative about 0.1 to 1.5 Gev /.% Fillers or extenders about 0.0 to 15 wt.% JiIn ₃ O ₄ smoke dust about 5.0 to 30 wt%  TiOp pigment. about 0.0 to 25 wt.% balance of water. .247525 1 -t- 4. Aqueous emulsion paint according to item 1, 2 or 3, characterized by a content of 0 to about 8 wt.% Of an antifreeze. 5 * Aqueous dispersion paint according to item 1, 2 ", 3 or 4, characterized by a content of 0 to about 10 of an alkyd resin. For this 1 page drawings