CS235887B1 - Core anticorrosive pigment and its production method - Google Patents

Abstract

Core anti-corrosion pigment based on inorganic pigments and fillers, consisting by weight of 70 to 92.5% of a titanium white core, iron pigments, aluminum and alkaline earth silicates, barium sulfate, silicon dioxide, mica, zinc white, lithopone, alkaline earth and magnesium carbonates, talc, foliated hematite and 2.5 to 30% of a coating consisting of zinc, calcium, magnesium, tin, manganese and aluminum phosphates. The coating is precipitated onto the surface from soluble or insoluble salts with alkaline phosphate or ammonium phosphate and phosphoric acid at pH 6 to 7. After precipitation, the product is filtered, washed, dried at a temperature of 110 to 160 °C and ground. This core pigment has an increased inhibitory effect, especially in the initial and final stages of corrosion, and significantly reduced raw material costs during production, and can be used in all types of anti-corrosion coatings.

Description

The invention relates to a core anti-corrosion pigment based on zinc phosphate containing calcium, magnesium, manganese and aluminum phosphates.

This new type of highly effective core anti-corrosion pigment was developed based on the experience with the development of core anti-corrosion pigment with zinc phosphate according to Qubomktlo ***&· * usm-a , *>/ c· , core anti-corrosion pigment with manganese phosphate according to 40 and AG 184 170 Inhibitory pigments based on zinc phosphates.

The core pigment with zinc phosphate has good inhibitory properties*. However, it is characterized by less activity in the initial and final phases of the protective system.

The best solution is to combine zinc phosphate with selected more soluble and less soluble phosphates of calcium, magnesium, manganese and aluminum.

In the initial phase of protective action, calcium phosphates CaHPG^.SHgO, magnesium MgHPO^.2B^G, for permanent action, proved to be good, and in the late phase of protective action, less soluble manganese phosphates In^/PG^/g^Ig® and aluminum AlP©^ proved to be more advantageous.

The most effective inhibitory properties were shown by core anticorrosive pigments treated with a mixture of zinc, calcium and manganese phosphate. However, it is possible to partially or completely replace calcium phosphate with magnesium phosphate and manganese phosphate with aluminum phosphate while maintaining good inhibitory properties.

The carriers forming the core of the anti-corrosion pigment are inorganic pigments and fillers, for example titanium dioxide, iron oxide, silicon dioxide, zinc oxide, lithopone, aluminum silicates, alkaline earth metals, alkali metals, calcium carbonates, magnesium carbonates and mixtures thereof.

- 2,235,887

The essence of the invention lies in the surface treatment of inorganic pigments and fillers with zinc phosphate containing calcium, magnesium, manganese and aluminum phosphates with the composition ZnO 40%, CaO or MgO 16%, MnO or ^Á Í2°3 4 ?2θ5 40%. This composition corresponds to the molar ratio of the components 1 PgO^ ^{: 1} ' ^{8 ZnO} θ ^{1 1} GaO ^netia : 0.2 MnO or Al^O^. The significantly increased inhibitory efficiency of the above-mentioned mixed phosphates precipitated on the surface of the carrier substance in comparison with the surface treatment: zinc phosphate alone is not given only by the above-mentioned ratio, but ranges within a wider range of molar ratios 1 ^2^5 ^: 2.8 ZnO : 0.3 to 2.8 CaO or MgO : 0.05 to 0.5 MnO or AlgGy. The total amount of precipitated anticorrosive substances on the surface of the carrier substance is 5 to 30%, preferably 10 to 15% by weight of the core pigment.

The production process is relatively simple and, depending on the chemicals used, there are basically two technological processes to choose from!

a/ The Bbs substance is dissolved in water at a temperature of 50 to 50°C to a concentration of 50 to 300 g/l. An aqueous solution of zinc, calcium or magnesium, and manganese or aluminum salts is measured into the suspension, then an equivalent amount of solution of sodium phosphate or phosphoric acid and alkali hydroxide is dosed over a period of 60 to 90 minutes at a constant temperature to a pH of 6.5 to 7.5. After 30 minutes, the suspension is filtered, washed, dried at a temperature of up to 160°C and ground.

b/ A suspension of a weighed amount of zinc oxide, calcium hydroxide or magnesium carbonate, and manganese carbonate or aluminum oxyhydrate is measured into the dissolved suspension of the carrier substance according to procedure a/. Then, an equivalent amount of 40% phosphoric acid is dosed into the suspension over 120 minutes at a temperature of 80 to 90°C with intensive stirring. The final pH is adjusted to a value of 6.5 to 7.5. The further procedure is the same as in point a/.

The progress achieved by the invention is mainly in that the inhibitory effect of the core anti-corrosion pigment with zinc phosphate is increased, especially in the initial and final stages of corrosion, and the costs of raw materials in its production are reduced. The invention can be applied to practically all types of coatings. Compared to classic inhibitory pigments based on lead oxides, chromates and zinc phosphate, it is possible to save 50 to 80% of anti-corrosion substances.

- 3 Example 1

235,887

100 g of anatase titanium white is melted with stirring at a temperature of 60°C to a volume of 330 ml in demineralized water and 13-1.6 ml of zinc sulfate solutionMsc with a concentration of 100 g ZnSO^/l, 131.1 ml of calcium chloride solution with a concentration of 50 g CaGlg/l and 12.1 ml of manganese sulfate with a concentration of 100 g MnSO^/l are added. Then, 451.2 ml of the solution is dosed uniformly over 60 minutes into sodium phosphate decahydrate with a concentration of 10Q g la^PO^ . 12H ₂ Q/l. After the final dosing, the suspension is stirred for another 15 minutes, then filtered, washed with demineralized water, dried at a temperature of up to 160¾ and ground. White anti-corrosion pigment contains 9.75% Zh^/PO^/g · 211.0,

4.32% CaHPO ₄ . 2^0 and 0.93% Mn ₃ /PQ ₄ / ₂ . 3^0.

Example 2

100 g of thermal iron red is dissolved with stirring at a temperature of 60^0 to a volume of 330 ml in demineralized water and a suspension containing 6.63 g of zinc oxide, 2.19 g of calcium hydroxide and 0.77 g of manganese carbonate is added. The suspension is heated to 80¾ and stirred for 15 minutes. Then it is dosed uniformly over 90 minutes

17.3 ml of 40% phosphoric acid. After the end of the dosing, the suspension is stirred for another 15 minutes, adjusted to pH 7 with alkaline hydroxide, the product is filtered, washed well with demineralized water, dried at a temperature of up to 160°C and ground.

The colored anti-corrosion pigment contains 9.75% Zn^/PQ^g · 2^0,

4.32% CaHPO ₄ . 2^0 and 0.93% Mn ₃ /P0 ₄ / ₂ . 3^0»

Example 3

100 g of kaolin is melted with stirring at a temperature of 60'°C to a volume of 330 ml in demineralized water, a suspension containing 6.63 g of zinc oxide, 2.8 g of magnesium carbonate and 0.46 g of aluminum oxide is added, the suspension is heated to 80'°C and stirred for 15 minutes. Then 18.8 ml of 40% phosphoric acid are dosed uniformly over 90 minutes. After the dosing is complete, the suspension is stirred for another 15 to 20 minutes and adjusted with alkaline hydroxide to pH 6.5 to 7.5, then filtered, washed in demineralized water, dried at a temperature of up to 160/C and ground.

The anticorrosive pigment contains 9.75% Zn ₃ /P0 ₄ / ₂ · 2^0, 4.32% MgSP0 ₄ . 2 Hgo _{and 0>93} % AlPO ₄ .

- 4 Example 4

The procedure is as in Example 1, except that barium sulfate is used.

235 887 that instead of titanium white

White anti-corrosion pigment contains 9.75% Zn^/PO^/^ · 21^0,

4.32% CaHPO ₄ . 2^0 and 0.93% Mn ₃ /PO ₄ / ₂ . 3H ₂ 0.

Example 5

The procedure is as in Example 2, except that instead of thermal red oxide, silicon dioxide is used.

White anti-corrosion pigment contains 9.75% Zn^/PQ^^ . 2^0,

4.32% CaHPO ₄ . 2^0 and 0.93% MnyTO^g . 3^0.

Example 6

The procedure is as in Example 3, except that mica is used instead of kaolin.

The anticorrosive pigment contains 9.75% Zn ₃ /P0 ₄ / ₂ · 2H ₂ 0, 4.32% . 2H ₂ oa and 0.93% AlPO ₄ .

Example 7

The procedure is as in Example 1, except that zinc white is used instead of titanium white.

White anti-corrosion pigment contains 9.75% Zn ₃ /PO ₄ / ₂ . 2H ₂ 0,

4.32% CaHPQ ₄ . 2^0 and 0.93% Mn ₃ /P0 ₄ / ₂ . IHgO.

Example 8

The procedure is as in Example 1, except that lithopone is used instead of titanium white.

White anti-corrosion pigment contains 9.75% Zn ₃ /PO ₄ / ₂ . 21^0,

4.32; % CaOPO ₄ . 21^0 and 0.93% Mn ₃ /PO ₄ / ₂ . 3H ₂ 0.

Example 9

The procedure is as in Example 1, except that chalk is used instead of titanium white.

White anti-corrosion pigment contains 9.75% Zn ₃ /P0 ₄ / ₂ . 2H ₂ 0,

4.32% CaBP0 ₄ . 2^0 and 0.93% phon ₃ /PO ₄ / ₂ . 3^0.

Example 10

The procedure is the same as in Example 2, except that instead of the red hot iron, talc is used.

Anti-corrosion pigment contains 9.75% Zn ₃ /P0 ₄ / ₂ .21^0 ,

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4.32% _Ca0PO4 . 2^0 and 0.93% Mn^P0 ₄ / ₂ . 31^0.

Example 11

The procedure is as in Example 3, except that hematite is used instead of kaolin.

The anti-corrosion pigment contains 9.75% Zh^/PO^g . 2H^0,

4.32% MgHPO ₄ .. 2H ₂ O and 0.93% Α1Ρ0 ₄ ·

Corrosion tests were performed in an aqueous extract of a paint film with pentaerythritol alkyd binder GHSP - L65, modified with 65% linseed oil with a volume concentration of 30% OKP, for a period of 10 days.

The test results are shown in the table in comparison with pure zinc phosphate, the alkyd binder used and water. As can be seen from the table, pigments and fillers treated with mixed zinc, calcium, manganese, magnesium and aluminium phosphates have a very good inhibitory effect.

Table.

Example Pigment ▼ filler phosphate corrosion inhiZn Ca Mg fe AI ní bic o- losses effect ¹⁰ Aim/year %

1 titanium white 9.75 4.32 - 0.93 - 1.1 97.39 2 thermal _in iron June 9.75 4.32 «» 0.93 - 1.2 97.15 3 kaolin 9.75 - 4.32 - - 0.93 1.3 96.91 4 barium sulfate 9.75 4.32 - 0.93 - 1.6 96.20 5 silicon dioxide 9.75 4.32 - 0.93 - 1 .0 97.62 6 mica 9.75 - 4.32 - 0.93 0.9 97.86 7 zinc white 9.75 4.32 «Ν» 0.93 «> 1.0 97.62 8 lithopone 9.75 4.32 - 0.93 - 1.2 97.15 9 chalk 9.75 4.32 - 0.93 - 1.3 96.91 10 talc 9.75 4.32 - 0.93 1 ,2 97.15 11 hematite 9.75 4.32 M» 0.93 0.9 97.86 «Η» zinc phosphate 1.9 95.49 - alkyd 35.8 14.96 - water 42.1 -

Claims (5)

1, core anticorrosive and fillers, characterized in that it consists of a core> β £ 43ΐ £ & 4-titanium bélobyl, iron oxide pigments, aluminum silicates and alkali ickýdi earth sulfate Burma 'silica slídiA, zinc Belot, lithopone ₈ carbonates, alkaline earth and magnesium, talc, and flaky hematite coating composed of zinc phosphate, calcium and / or magnesium, manganese and / or aluminum constituting by weight 2.5 to 30%, preferably 10 to 15% of the total weight of the core pigment, zaiimolárníha 1 ratio _of P ₅ 0: 0.2 to 2.8 ZnO: 0.2 to 2.8 CaO, MgO: 0.2 to 0.5 MnO, Al ^, preferably 1 ^ 2 ^ 5 ^{^ -NO:} ΜηΟ, Α ^Ο · 2. A process according to claim 1, wherein an aqueous solution of zinc sulfate, magnesium sulfate and / or calcium chloride and aluminum sulfate is added to the aqueous suspension 6 at a concentration of 50 to 300 g / l with stirring over 5 to 10 minutes. - and / or manganese sulphate at a concentration of 50 to 100 g / l, the suspension is heated to 60 ° C and an equivalent amount of an alkaline or ammonium phosphate solution of 50 to 100 g / l and the treated product is uniformly dosed within 60 to 90 minutes The mixture is filtered, washed, dried at a temperature of up to 110 ° C and ground. 3. A process for the production of a core anticorrosive pigment e. Filler according to claim 1, characterized in that the aqueous suspension is iD-W. 50 to 300 g / l, with agitation for 5 to 10 minutes, add an aqueous solution of magnesium sulphate, zinc sulphate and aluminum sulphate at a concentration of 50 to 100 g / l; An equal amount of an alkaline or ammonium phosphate solution having a concentration of 50-100 g / l is uniformly metered in and the treated product is filtered, washed, dried at a temperature of 110 DEG C. and ground. 4. A method according to claim 1, wherein a suspension of zinc oxide, calcium hydroxide and manganese carbonate at a concentration of 50 to 300 g / l is added to the aqueous suspension at a concentration of 50-300 g / l with stirring over a period of 5-10 minutes. 100 g / l, the suspension is heated to 80 ° C and an equivalent amount of 40% phosphoric acid is added uniformly over a period of 120 to 180 minutes, and the suspension is stirred for 30 minutes after cooling to 50 ° _C. The treated product is filtered, washed and dried at a temperature of up to 7235,887 110 ° Gaa ground. 5. A process according to any one of Claims 4 to 4, characterized in that: the calcium phosphate is at least partially replaced by magnesium phosphate and the manganese phosphate is at least partially replaced by aluminum phosphate.