WO2012048985A1 - Particules d'oxyde de fer enrobées - Google Patents

Particules d'oxyde de fer enrobées Download PDF

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Publication number
WO2012048985A1
WO2012048985A1 PCT/EP2011/066203 EP2011066203W WO2012048985A1 WO 2012048985 A1 WO2012048985 A1 WO 2012048985A1 EP 2011066203 W EP2011066203 W EP 2011066203W WO 2012048985 A1 WO2012048985 A1 WO 2012048985A1
Authority
WO
WIPO (PCT)
Prior art keywords
particles
iron oxide
coated iron
mixture
oxide particles
Prior art date
Application number
PCT/EP2011/066203
Other languages
German (de)
English (en)
Inventor
Stipan Katusic
Peter Kress
Harald Herzog
Nuh Yilmaz
Frank Minister
Mario Scholz
Original Assignee
Evonik Degussa Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE201010042505 external-priority patent/DE102010042505A1/de
Priority claimed from DE201110003502 external-priority patent/DE102011003502A1/de
Application filed by Evonik Degussa Gmbh filed Critical Evonik Degussa Gmbh
Publication of WO2012048985A1 publication Critical patent/WO2012048985A1/fr

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/02—Oxides; Hydroxides
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/02—Oxides; Hydroxides
    • C01G49/06—Ferric oxide [Fe2O3]
    • 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
    • C09C1/22—Compounds of iron
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/10—Particle morphology extending in one dimension, e.g. needle-like
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
    • C01P2004/82—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases
    • C01P2004/84—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases one phase coated with the other
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/80—Compositional purity

Definitions

  • the invention relates to iron oxide particles coated with a metal oxide, their preparation and use.
  • the invention further relates to a silicone rubber containing these particles.
  • the inductive heating of composites containing magnetic particles is a promising way for a rapid and gentle curing of adhesive bonds or for the crosslinking of polymers. It has proven to be advantageous to use coated magnetic particles.
  • the shell is attributed the function, on the one hand to improve the incorporation into the networks and on the other to prevent unwanted growth of the magnetic phases.
  • such particles can be solvent-based
  • WO 2010/063557 can be maintained and at the same time significantly increase the heating rate in inductive heating over the prior art.
  • the invention is partially or completely enveloped
  • Iron oxide particles which are needle-shaped, comprising a maghemite and magnetite-comprising core and a shell comprising a metal oxide or metalloid oxide.
  • the detection of the iron oxide modifications maghemite and magnetite, as well as hematite can preferably be carried out by means of X-ray structure analysis.
  • the coated iron oxide particles preferably have a length of 0.2 to 5.0 ⁇ m and a width of 0.1 to 3 ⁇ m, with a length / width ratio of 2: 1 to 20: 1.
  • the particles according to the invention have little or no porosity and the BET surface area is generally 1 to 50 m 2 / g, preferably 5 to 20 m 2 / g.
  • the shell material is firmly and irreversibly connected to the iron oxide. It may be present in the form of isolated and / or aggregated, largely spherical particles on the needle-shaped FeOOH particles (schematically in FIG. 1A). It is also possible that the isolated and / or aggregated, largely spherical particles are surrounded by a matrix of the enveloping material (schematically in FIG. 1B). Under matrix is a
  • the average diameter of the largely spherical particles may preferably be 2 to 50 nm.
  • the thickness of the shell may be 2 to 100 nm, with a thickness of 5 to 50 nm being particularly preferred.
  • shell material for example, silica, alumina,
  • the shell material may comprise a mixed oxide, for example silicon-aluminum mixed oxide.
  • the shell material comprises or consists of silica, alumina, ceria, titania or zirconia.
  • silica is particularly preferred.
  • the core of the particles according to the invention comprises maghemite and magnetite.
  • the proportions of these components can be variably adjusted.
  • the particles according to the invention can have a maghemite / magnetite ratio of 99: 1 to 1:99, preferably 50:50 to 20:80.
  • the core may also contain hematite. This proportion can be up to 60%, based on the sum of magnetite, maghemite and hematite, all calculated as Fe 2 03. In general, the proportion is 5 to 40%.
  • X-ray iffractometry determined proportion of magnetite 20 to 80%, at
  • the particles according to the invention may contain up to 2% by weight, but generally less than 1% by weight of alpha-iron.
  • the coated iron oxide particles according to the invention should have at least a proportion of iron oxide, calculated as Fe 2 O 3 , of more than 50% by weight.
  • the proportion of iron oxide is preferably 60 to 95% by weight and more preferably 80 to 90% by weight.
  • the data are to be understood so that the difference to 100 wt .-% corresponds to the proportion of Hüllstoffes.
  • the particles according to the invention have not more than 1% by weight, preferably not more than 500 ppm, of chloride. Lower chloride values are achieved, for example, when low-chlorine or chlorine-free starting compounds are used in the preparation. In these cases, the content of chloride is usually less than 100 ppm.
  • the particles according to the invention have a largely or completely closed shell.
  • a method can be used, in which one at
  • Another object of the invention is a process for the preparation of the coated iron oxide particles in which
  • the temperature is preferably 300 to 800 ° C, more preferably 550 ° C to 750 ° C and most preferably 600 to 700 ° C, one or more Hüllstoff- output compounds added are,
  • Hüllstoff starting compounds according to b) are used, wherein the sum of the Hüllstoffpumble and the Hüllstoff- starting compounds, calculated as metal oxide or metalloid oxide, the amount of metal oxide or metalloid oxide, as present in the later coated iron oxide particles, wherein the iron oxide content calculated as Fe 2 03 is
  • the oxygen-containing gas mentioned under a) is used in the
  • the feature c) which states that the filler particles are used in the aerosol and / or shell-starting compounds, is to be understood as meaning that the later silicon dioxide content in the particles according to the invention is
  • the high temperature zone may, for example, take the form of an external
  • high-temperature zone represents a flame which is formed by igniting a mixture of a hydrogen-containing fuel gas, preferably hydrogen, and an oxygen-containing gas, preferably air, in a reaction space spatially separate from the aerosol.
  • a hydrogen-containing fuel gas preferably hydrogen
  • an oxygen-containing gas preferably air
  • FIG. 2A schematically shows an arrangement in which the high-temperature zone is formed by a flame which is formed by igniting a mixture of a hydrogen-containing fuel gas and an oxygen-containing gas in a reaction space spatially separated from the aerosol.
  • A needle-shaped FeOOH particles, optionally shell particles, and
  • the mean residence time in the high-temperature zone is preferably 0.5 seconds to 1 minute, preferably 5 to 20 seconds. It is marked with ti in FIG. 2A. It refers to the zone in which the aerosol is reacted in the reducing gas atmosphere.
  • the invention also provides a further process for the preparation of particles according to the invention, in which
  • oxygen-containing gas preferably air
  • excess hydrogen-containing fuel gas preferably hydrogen
  • the filler particles in the aerosol according to a) and / or Hüllstoff starting compounds according to c) are used, wherein the sum of the Hüllstoffpumble and the Hüllstoff- starting compounds, calculated as metal oxide or metalloid oxide, the amount of metal oxide or metalloid oxide, as present in the later coated iron oxide particles, wherein the iron oxide content as Fe 2 03 is calculated,
  • Figure 2B shows an arrangement in which the aerosol is reacted in the presence of a flame formed by reacting a hydrogen-containing fuel gas with an oxygen-containing gas.
  • A needle-shaped FeOOH particles, optionally hüllstoffp microparticle, and
  • Excess hydrogen-containing fuel gas is to be understood as meaning that the ratio of hydrogen-containing fuel gas to the sum of oxygen in the oxygen-containing gas and FeOOH particles, in mol / mol, is greater than 1, preferably from 1:01 to 10 and particularly preferably from 2 to 5 ,
  • An excess of oxygen-containing gas is to be understood as meaning that the ratio of oxygen in the oxygen-containing gas used to the conversion of the hydrogen-containing fuel gas and the resulting from the reducing treatment iron compounds
  • the mean residence time of the substance mixture, which comprises the acicular FeOOH particles and possibly the filler particles containing aerosol, the oxygen-containing gas and excess hydrogen-containing fuel gas may be 0.5 seconds to 1 minute, preferably 5 to 20 seconds. It is marked with ti in FIG. 2B.
  • the mean residence time of the substance mixture, which can be reacted in the flame can be 0.5 to 30 seconds, preferably 1 to 10 seconds, in both processes according to the invention. It is marked with t 2 in FIGS. 2A and 2B.
  • the calculation of t 2 should be based on the ignition of the flame until the supply of water and / or air for cooling.
  • the aerosol used in the method according to the invention is
  • the dispersion is usually an aqueous dispersion having a content of FeOOH particles of preferably 5 to 25 wt .-%.
  • the dispersion may contain dispersing additives, typically in a concentration of 0.05 to 2.00% by weight, based on the dispersion, such as polyacrylic acid and salts thereof.
  • dispersions in the alkaline range, in particular with pH values of 8 to 11, are preferably used in this case.
  • the needle-shaped FeOOH particles used may be doped with at least one element selected from the group consisting of P, Si, Al, Mg, Co, K and Cr. Such dopants are usually added in small amounts in the course of the synthesis of the oxides to be doped with at least one element selected from the group consisting of P, Si, Al, Mg, Co, K and Cr. Such dopants are usually added in small amounts in the course of the synthesis of the oxides to
  • the filler particles used in the process according to the invention are metal oxides or metalloid oxides. This may be preferred.
  • silica particles are particularly preferred. These may be colloidal or pyrogenic silica particles. In general, the primary particle diameter is 5 to 50 nm, preferably 10 to 30 nm.
  • Reaction conditions are converted into metal oxide or metalloid oxide. They can be used as such in the form of a liquid, in the form of a solution or in the form of steam. With particular preference, they are used in the vapor state. The dosage can be done for example by means of a nozzle.
  • shell-starting compounds SiCl 4 H 3 SiCl, H 2 SiCl 2 , HSCl 3, CH 3 SCl 3 , (CH 3 ) 2 SiCl 2 , (CH 3 ) 3 SiCl and / or (nC 3 H 7 ) SiCl 3 are suitable. Particularly preferred is Si (OC 2 H 5 ) 4 .
  • a further subject is silicone rubber containing coated iron oxide particles according to the invention.
  • the proportion of the particles according to the invention is preferably 0, 1 to 10 wt .-% and particularly preferably 1 to 6 wt .-%, each based on the silicone rubber.
  • Silicone rubber may be HTV silicone rubber, LSR silicone rubber or RTV1 -K silicone sealant. Preferred is an HTV silicone rubber.
  • Silicone rubber crosslinkers fillers, catalysts, color pigments,
  • Another object of the invention is the use of the
  • coated iron oxide particles according to the invention as a constituent of
  • Rubber compounds being part of polymer preparations, as Component of adhesive compositions, as part of welding in electromagnetic alternating field available
  • the present invention provides particles which are ideally suited for inductive heating.
  • the metal oxide shell is a chemical shielding of the magnetic portion of a particle of other magnetic particles, so that agglomeration of the particles can be largely or completely avoided.
  • Silica dispersion It becomes NexSil 12 TM, NYACOL, an aqueous dispersion of colloidal silica particles containing 30% by weight of S1O2, a pH of 10 and a BET surface area of 227 m 2 / g used.
  • Aluminum oxide dispersion It is NYACOL AL20 ®, from NYACOL, an aqueous dispersion of colloidal alumina particles with a content of Al2O3 of 20 wt .-%, a pH of 4 and a particle size of 50 nm..
  • Dispersions AE With stirring, first NexSil 12 TM and K 2 HPO 4 , in the case of dispersion E, and subsequently the FeOOH particles are added to water. In the case of dispersion C, CH 3 OH is subsequently added.
  • Dispersion F With stirring, first NYACOL AL20 and subsequently the FeOOH particles are added to water.
  • Example 1 1000 g / h of dispersion A are atomized with 4.0 Nm 3 / h of nitrogen.
  • the aerosol is mixed with 1, 1 Nm 3 / h of hydrogen (H 2 -1).
  • This mixture of substances is heated externally.
  • the heat source used is a flame obtained by ignition of a second mixture of 19.0 Nm 3 / h of air (air-2) and 5.0 Nm 3 / h of hydrogen (H 2 -2).
  • air-2 19.0 Nm 3 / h of air
  • H 2 -2 5.0 Nm 3 / h of hydrogen
  • the product deposited on a filter.
  • the product consists of silica particle coated needles of iron oxide.
  • iron oxide modifications magnetite, maghemite and hematite, in a composition calculated as Fe 2 O 3 , respectively, of 55: 14:31 are detected.
  • the ratio Fe 2 O 3 / SiO 2 is 90:10.
  • the BET surface area is 10 m 2 / g.
  • the leach test gives a value of 26 ppm Fe in solution and indicates a dense silica shell.
  • the heating rate is determined in a silicone composition.
  • the silicone composition is obtained by mixing 33 g ELASTOSIL ® E50, Fa. Momentive Performance Materials, 13 g of silicone oil type M 1000, Fa. Momentive Performance Materials, 4 g of Aerosil ® 150, Fa.
  • Example 2-5 are carried out analogously to Example 1. Starting materials and operating conditions are given in Table 2. The physicochemical properties of the products obtained are shown in Table 3.
  • Example 6 2000 g / h of the dispersion B are atomized with 4.0 Nm 3 / h of nitrogen.
  • the aerosol is mixed with 7.0 Nm 3 / h of hydrogen and 3.3 Nm 3 / h of air (air-1) and ignited. After a mean residence time of 6.4 s, 15.0 Nm 3 / h of air (air-2) are added.
  • the resulting mixture reacts at a temperature of 1057 ° C and a mean residence time of 2.2 s.
  • the resulting mixture is subsequently cooled and the product is deposited on a filter.
  • the product consists of silica particle coated needles of iron oxide. Magnetite, maghemite and hematite, in a composition calculated as Fe 2 O 3 , of 32:15:53, respectively, are detected as iron oxide modifications. The ratio Fe 2 0 3 / Si0 2 is 90:10. The BET surface area is 18 m 2 / g. The leach test gives a value of 35 ppm Fe in solution and indicates a dense silica shell.
  • the heating rate is determined as described in Example 1.
  • Examples 7-9 are carried out analogously to Example 6. Starting materials and operating conditions are given in Table 2. The physical Chemical properties of the products obtained are shown in Table 3.
  • Example 10 2000 g / h of dispersion E are atomized with 4.0 Nm 3 / h of nitrogen.
  • the aerosol is mixed with 3.0 Nm 3 / h of hydrogen (H 2 -1) and this first mixture of substances is heated externally.
  • the heat source used is a flame obtained by ignition of a second mixture of 14.6 Nm 3 / h of air (air-2) and 3.0 Nm 3 / h of hydrogen (H 2 -2).
  • air-2 3.0 Nm 3 / h of hydrogen
  • After a mean residence time of 4, 1 s the resulting from the first and second mixture mixture derived products are combined at an available temperature of 585 ° C and a mean residence time of 2.6 s.
  • the product consists of silica particle coated needles of iron oxide.
  • iron oxide modifications magnetite, maghemite and hematite, in a composition, calculated in each case as Fe 2 O 3, of 65:22:13 detected.
  • the Fe 2 O 3 / SiO 2 ratio is 85: 15.
  • the BET surface area is 9 m 2 / g.
  • the leach test gives a value of 8 ppm Fe in solution and indicates a dense silica shell.
  • the heating rate of silicone rubber is determined as described in Example 1.
  • Examples 1 1 -12 are carried out analogously to Example 10. Starting materials and operating conditions are given in Table 2. The physicochemical properties of the products obtained are shown in Table 3.
  • Examples 13-14 are carried out analogously to Example 10, but using the dispersion A and those mentioned in Table 2 Amounts of starting materials.
  • the physico-chemical properties of the products obtained are shown in Table 3.
  • Example 15 is carried out analogously to Example 1, but using dispersion F instead of A.
  • Starting materials and amounts of starting material are reproduced in Table 2.
  • the physico-chemical properties of the products obtained are shown in Table 3.
  • FIG. 3 shows the heating curve of various compressed powders brought about by induction at 40 kHz.
  • the x-axis shows the induction time in s
  • the y-axis the temperature in ° C. 1 is the particles according to the invention from example 3, 2 and 3 are commercially available powders. It turns out that with the particles according to the invention the highest temperatures and the best heating rates can be achieved. Also noteworthy is the stability with a longer induction time.
  • silicone rubber formulations are prepared at 6 phr, Example 16-6, and 9 phr, Example 16-9. As a comparison serves a formulation without particles, Example 16-0.
  • Particles according to the invention reaches a temperature of 120 ° C in the high frequency range after about 2 seconds.
  • the particles according to the invention are also distinguished by their heat-stabilizing properties

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Compounds Of Iron (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

L'invention concerne des particules d'oxyde de fer enrobées, en forme d'aiguilles, qui présentent un noyau comprenant de la maghémite et de la magnétite et un enrobage comprenant un oxyde de métal ou de métalloïde. Elles sont préparées en faisant réagir, dans une zone à haute température, un aérosol contenant des particules de FeOOH en forme d'aiguilles et, éventuellement, des particules de substance d'enrobage dans une atmosphère gazeuse réductrice, puis en amenant le mélange de substances obtenu en contact avec un volume d'un gaz contenant de l'oxygène, suffisant pour oxyder complètement le mélange de substances; éventuellement en ajoutant plusieurs composés de départ de la substance d'enrobage; ensuite en refroidissant le mélange de substances et en séparant le solide. L'invention concerne également un caoutchouc de silicone contenant les particules d'oxyde de fer enrobées.
PCT/EP2011/066203 2010-10-15 2011-09-19 Particules d'oxyde de fer enrobées WO2012048985A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE102010042505.2 2010-10-15
DE201010042505 DE102010042505A1 (de) 2010-10-15 2010-10-15 Umhüllte Eisenoxidpartikel
DE102011003502.8 2011-02-02
DE201110003502 DE102011003502A1 (de) 2011-02-02 2011-02-02 Umhüllte Eisenoxidpartikel

Publications (1)

Publication Number Publication Date
WO2012048985A1 true WO2012048985A1 (fr) 2012-04-19

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TW (1) TW201231401A (fr)
WO (1) WO2012048985A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014023540A1 (fr) 2012-08-07 2014-02-13 Evonik Industries Ag Particules d'oxyde de fer et de silicium ayant une vitesse d'échauffement améliorée
DE102013215498A1 (de) 2013-08-07 2015-02-12 Evonik Industries Ag Eisenoxid und Siliciumdioxid enthaltende Kern-Hülle-Partikel mit verbesserter Aufheizgeschwindigkeit

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108217750B (zh) * 2018-03-09 2020-02-28 东北大学 一种α-Fe2O3/FeOOH复合功能材料及其制备方法和应用

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4267207A (en) * 1977-03-16 1981-05-12 Fuji Photo Film Co., Ltd. Process for producing cobalt-containing ferromagnetic iron oxide powder
US5531922A (en) * 1992-08-04 1996-07-02 Toda Kogyo Corporation Granulated particles for magnetic particles for magnetic recording, and process for producing the same
US5626962A (en) * 1994-03-04 1997-05-06 Toda Kogyo Corporation Co-coated acicular magnetite particles and process for producing the same
WO2010063557A1 (fr) 2008-12-05 2010-06-10 Evonik Degussa Gmbh Particules d'oxyde de fer-silicium dotées d’une structure de type cœur-écorce

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4267207A (en) * 1977-03-16 1981-05-12 Fuji Photo Film Co., Ltd. Process for producing cobalt-containing ferromagnetic iron oxide powder
US5531922A (en) * 1992-08-04 1996-07-02 Toda Kogyo Corporation Granulated particles for magnetic particles for magnetic recording, and process for producing the same
US5626962A (en) * 1994-03-04 1997-05-06 Toda Kogyo Corporation Co-coated acicular magnetite particles and process for producing the same
WO2010063557A1 (fr) 2008-12-05 2010-06-10 Evonik Degussa Gmbh Particules d'oxyde de fer-silicium dotées d’une structure de type cœur-écorce

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HANEDA ET AL.: "magnetite to maghemite transformation in ultrafine particles", JOURNAL DE PHYSIQUE, vol. 38, no. supplément au n°4, April 1977 (1977-04-01), pages C1-321 - C1-323, XP002665344 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014023540A1 (fr) 2012-08-07 2014-02-13 Evonik Industries Ag Particules d'oxyde de fer et de silicium ayant une vitesse d'échauffement améliorée
DE102012213986A1 (de) 2012-08-07 2014-05-15 Evonik Industries Ag Eisen-Silicium-Oxidpartikel mit verbesserter Aufheizgeschwindigkeit
CN104520241A (zh) * 2012-08-07 2015-04-15 赢创工业集团股份有限公司 具有改善的加热速率的铁-硅氧化物颗粒
US10204723B2 (en) 2012-08-07 2019-02-12 Evonik Degussa Gmbh Iron-silicon oxide particles having an improved heating rate
DE102013215498A1 (de) 2013-08-07 2015-02-12 Evonik Industries Ag Eisenoxid und Siliciumdioxid enthaltende Kern-Hülle-Partikel mit verbesserter Aufheizgeschwindigkeit

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