Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/14—Compounds of lead
  • C09C1/20—Lead chromate
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C3/00—Treatment in general of inorganic materials, other than fibrous fillers, to enhance their pigmenting or filling properties
  • C09C3/06—Treatment with inorganic compounds
  • C09C3/063—Coating

Definitions

• the invention relates to improved chrome yellow and molybdate red pigments and, in particular, to the lead chromate pigments based on the products declared according to the Color Index, 3rd edition 1971
• the precipitation of silica or silicate and / or a wide variety of insoluble metal hydroxides can improve weather and light fastness.
• a particularly significant improvement in the light and weather fastness of chrome yellow and molybdate red pigments is achieved by the precipitation of trivalent antiiron oxide as described in DE-PS 12 24 858.
• the use of the trivalent antimony compound results in a partial reduction of chromium (VI) to chromium (III) on the surface of the pigment particles, which obviously leads to a stabilization of the pigment surface and an improvement in the light and weather fastness of such pigments. It is disadvantageous that the color brilliance is reduced by the formation of the trivalent green chrane compound.
• DE-PS 12 53 384 antimony 3 compounds and soluble salts of silicic acid or water-soluble salts containing antimony III ions, fluorine ions and silications are proposed as stabilizing components to improve the resistance of molybdate red or molybdate orange pigments to improve against sulphurous acid.
• DE-PS 27 06 545 and 27 35867 deal with the improvement of the SO 2 resistance of lead bleach pigments by the precipitation of zinc metaphosphate or cermetaphosphate, an SO 2 resistance according to DIN 50 018 (Kesternich) of max. 5 cycles is achieved.
• pigments reduced with antimony, tin or manganese compounds are proposed for coating with dense amorphous silica and murninium oxide, end products being obtained with very good lightfastness and temperature resistance.
• the disadvantage of these pigments is that the reduction in color, ie partial conversion of Cr (VI) to Cr (III), means that they have clearly lost their color brilliance.
• the US-PS 40 17 328 provides the addition of small amounts of SiO 2 and metal hydroxide before the actual precipitation and coat these base pigments according to known methods (US-PS 33 70 971) with a coating of dense amorphous silica and aluminum oxide.
• the pigments obtained in this way are said to have good lightfastness, chemical resistance and temperature resistance; in order to stabilize the base pigment according to US Pat. No. 4,017,328, antimony is also recommended in addition to the hydroxides of other metals.
• antimony (III) compounds are used to produce the so-called pre-darkened chromate pigments.
• the reduction results in dirty and not color-clear chromate pigments from the start, which leads to an impairment of the color brilliance of these pigments.
• the object of the invention is therefore the production of temperature-stable and brilliantly colored chrome yellow and molybdate red pigments, especially lead chromate and lead molybdate pigments with very high fastness properties when exposed to temperature, light, acids and alkalis and also with extremely low acid-soluble lead components according to DIN / ISO 6713 of ⁇ 0.5%.
• this object could be achieved in that the chrome yellow or molybdate red pigments, in particular those at the beginning by the CI or CONST. No. defined pigments, after stabilization with small amounts of alkali silicate and / or metal hydroxide on the basis of the metals aluminum, titanium, manganese, cerium or other suitable metals, initially using known processes, as described in US Pat. Nos.
• Silicate / metal / silicate layers causes, which has an advantageous effect on the resistance of the cladding components against external influences.
• the filtration properties of the pigments are also improved by this aftertreatment.
• the process according to the invention makes it possible to produce temperature-stable and brilliantly colored chrome yellow and molybdate red pigments, in particular lead chromate, lead sulfochromate and molybdate red pigments, which are distinguished by very high fastness properties and resistance to the action of heat, weather, light, acids and alkalis.
• the taiperat resistance to the products obtained according to US Pat. Nos. 36 39 133, 37 98 045 and 4017328 and 4059459 could be considerably improved.
• these pigments, with their improved temperature resistance are distinguished by high color brilliance, which is otherwise not present in lead chloride ⁇ -pigments stabilized with antimony oxides.
• the acid solubility according to DIN / ISO 6713 could be reduced to ⁇ 0.5% Pb by the process according to the invention.
• the pigments prepared according to the invention achieved up to more than 10 cycles without the color tone of a Mkyd melamine coating noticeably changing.
• the pigments produced according to US Pat. Nos. 36 39 133, 39 29500, 37 98 045 and 40 17328 and 4059 459 only 3-4 cycles without color change (DE ⁇ 3, see Table 1) could be achieved.
• Pigment particles with the usual SiO 2 coating The treatment according to the invention apparently has a synergistic effect.
• a lead sulfochromate pigment corresponding to CI Pigment Yellow 34, CONST. NO. 77 603, which has been stabilized in a conventional manner, for example in accordance with US Pat. No. 3,370,971 with small amounts of alkali silicate and / or metal oxides, are slurried in 3 l of water and 20 g of sodium water glass with 21% SiO 2 (1:10 in water) in a high pressure homogenizer to break up the
• Soda water glass with 21% SiO 2 (1:10 in water) was run in, a pH of 7.5 being established.
• the aftertreatment is carried out using a solution of 17 g of barium chloride (1:20 in water) and subsequent addition of 8 g of a chain-shaped condensed soluble polyphosphate (1:10 in water).
• the final pH should be 7.5.
• the coated pigment is worked up by filtration, washing free from salt, drying at 100 ° C. and grinding with the customary grinding units.
• Example 2 The same lead sulfochromate pigment as in Example 1 in an amount of also 200 g was treated in the same manner as described in Example 1, the stabilization with antimony oxide being modified in the following manner. 12 g of a 25% by weight antimony chloride solution were added to the suspension, which had been adjusted to pH 8, a pH of 6 being maintained by adding sodium carbonate solution. After 30 minutes of stirring, the addition of 2 g of sodium water glass in 20 ml of water to pH 7.3 (ie half the amount as in Example 1). The process was then carried out in a second stage with equal amounts of antimony chloride solution and
• Temperature-stable chrome yellow pigments were obtained with high color brilliance, very low acid-soluble lead components according to DIN / ISO 6713 and very high other fastness properties.
• Red 104 (CONST. NO. 77 605) is first stabilized with alkali silicate and / or metal oxide in the usual known manner (US Pat. No. 4,059,459 or German Pat. No. 12 24 858). The mixture was then filtered and washed free of salt. The salt-free pigment slurry is slurried in 3 liters of water and submerged
• the pH is adjusted to 8.0 with dilute sulfuric acid (1:50) and 24 g of a 25% by weight antimony chloride solution are added, the pH being kept at 6.0 with sodium carbonate solution (1:10) becomes. After stirring for 30 minutes, the pH is adjusted to 7.5 with a solution of 4 g of sodium silicate (1:10) and 7 g of aluminum sulfate (1:10) are added.
• the usual work-up was carried out by filtration, salt-free washing, drying at 100 ° C. and grinding with the usual grinding units.
• the molybdate red pigment obtained was characterized by temperature resistance up to 320 ° C., high color brilliance, very low acid-soluble lead components according to DIN / ISO 6713 and very high other fastness properties.
• the molybdate red pigment (01) produced according to the invention was compared with the following pigments using the test parameters listed according to Examples 1 and 2:

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 1988
  • 1988-02-26 DE DE3806214A patent/DE3806214C1/de not_active Expired
• 1989
  • 1989-02-23 DE DE8989904808T patent/DE58903668D1/de not_active Revoked
  • 1989-02-23 AU AU34463/89A patent/AU3446389A/en not_active Abandoned
  • 1989-02-23 EP EP89904808A patent/EP0372028B1/de not_active Revoked
  • 1989-02-23 HU HU892580A patent/HU204545B/hu not_active IP Right Cessation
  • 1989-02-23 ZA ZA891423A patent/ZA891423B/xx unknown
  • 1989-02-23 WO PCT/EP1989/000167 patent/WO1989008131A1/de not_active Ceased
  • 1989-02-24 DD DD89325999A patent/DD283639A5/de not_active IP Right Cessation
  • 1989-02-25 ES ES8900689A patent/ES2012666A6/es not_active Expired - Lifetime

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