CA1126453A - Mineral substance based on a reversibly swellable tri-laminar mineral developed to be crystalline over a large area and having crystal layers separated from one another - Google Patents
Mineral substance based on a reversibly swellable tri-laminar mineral developed to be crystalline over a large area and having crystal layers separated from one anotherInfo
- Publication number
- CA1126453A CA1126453A CA307,094A CA307094A CA1126453A CA 1126453 A CA1126453 A CA 1126453A CA 307094 A CA307094 A CA 307094A CA 1126453 A CA1126453 A CA 1126453A
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- CA
- Canada
- Prior art keywords
- mineral
- particles
- tri
- laminar
- polar liquid
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/20—Silicates
- C01B33/26—Aluminium-containing silicates, i.e. silico-aluminates
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- A01N25/00—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests
- A01N25/08—Biocides, pest repellants or attractants, or plant growth regulators, characterised by their forms, or by their non-active ingredients or by their methods of application, e.g. seed treatment or sequential application; Substances for reducing the noxious effect of the active ingredients to organisms other than pests containing solids as carriers or diluents
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/02—Granular materials, e.g. microballoons
- C04B14/04—Silica-rich materials; Silicates
- C04B14/20—Mica; Vermiculite
- C04B14/204—Mica; Vermiculite expanded
Abstract
ABSTRACT OF THE DISCLOSURE
A reversibly swellable tri-laminar mineral is disclosed having a crystalline structure over a large area, with the crystal layers separated from one another. The process for production of the mineral from vermiculite, hydro-mica or mixed-layer mineral is also disclosed. The novel mineral is useful as a fire-proofing compound and as a plant protection agent.
A reversibly swellable tri-laminar mineral is disclosed having a crystalline structure over a large area, with the crystal layers separated from one another. The process for production of the mineral from vermiculite, hydro-mica or mixed-layer mineral is also disclosed. The novel mineral is useful as a fire-proofing compound and as a plant protection agent.
Description
~26~53 Vermiculite is a member of the mica-type earth minerals, which have an expansible crystal lattice, wherein the crystals are of parallel lamellar formation. It is closely related to the montmorillonite-saponite mineral group. The mineral belongs to the tri-laminar silicates and contains water intercalated between adjacent laminations. Because the laminations are not rigidly bonded to one another, vermiculite is subject to an intracrystal-line swelling ability, illustrated by the ability of vermiculite crystals to expand to about 30 times their original thickness in one direction on being quickly heated.
The structure and properties of vermiculite have been described in Romppls Chemie-Lexikon, Frankh'sche Verlagshandlung, Stuttgart, 7th Edition, heading 3000, as consisting of a composi-tion of the following formula: Mg3(Al,Si)4010(0H)2(H20)4. In addition vermiculite contains considerable quantities of combined iron (Fe).
"Hydro-micas" and "mixed-layer minerals" also have this ability to expand. The latter minerals also include those in which, for example, vermiculite laminations and mica laminations crystallize in alternating random sequence.
A description of the mineral starting material, vermicu-lite, can be found in "Mineralogical Tables", 5th Edition by Hugo Strunz (Leipzig 1970, Akademische Verlagsgesellschaft, Geest & Portig KG.) at page ~7.
A description of the mineral starting material, hydro-mica, can be found in "The Physical and Chemical Principles of Ceramics" by Salmang-Scholz (Springer Verlag, New York, 1968).
According to the present invention there is provided a reversibly swellable tri-laminar mineral which is crystalline over a large area, with the crystal layers separated from one another, characterized in that said tri-laminar mineral is produced from a ~Zt~53 fine-grain vermiculite, hydro-mica or mixed-layer mineral which incorporates non-swellable mica in intra-crystalline form between layers of said vermiculite or hydro-mica by swelling with a polar liquid and subsequent comminution into tabular particles; said mineral having more than 50 percent by weight of said tubular particles, having an extremely thin planar dimension with a thickness of from 0.5 to 10 microns and with surface dimensions corresponding to an equivalent diameter of from 10 to 200 microns and with a ratio between particle thickness and equivalent diameter equal to or smaller than 1:10, which particles are disposed substantially side by side in flat layers, and which particles demonstrate extensive plasticity when the water content of the mineral is from 35~ to 65~ by weight, said particles possessing hydrophilic properties on the planar surfaces thereof permitting the particles to quickly take up or give off polar liquids, and upon taking up a polar liquid, the particles swell, and upon giving off a polar liquid, the particles shrink, in a single direction which is perpendicular to the tubular plane of the particles.
The invention also provides a process for preparation of the mineral defined above, in which a fine-yrain vermiculite, hydro-mica or mixed-layer mineral is swelled with a polar liquid and subsequently meckanicallycomminuted, while preserving its structure, into extremely thin, uniformly planar, tubular particles.
The novel mineral according to the invention demonstrates various properties not found in the mineral starting compounds.
For example, the structure of the mineral results in strong adhesion and cohesion forces. The mineral exhibits a specific shrinkage behavior on being dried from a dispersion or upon being dried from moistenea or wetted dry mass. The surface dimensions , . .
~Z~4~3 of the tabular particles shrink in surface dimensions by 0.5 to 1.5% (length and breadth~ and in thickness by about 25% to 35%.
Generally the mineral when dried on a surface from a dispersion in a polar liquid, such as water, either by .itself or admixed with other substances, does not form any shrinkage cracks.
Many o~ the advantages of the mineral according to the - 2a -....
~Z64~53 invention are due to its inorganic composition and incombustibility. Among the technical advantages are included the use of the mineral as a binder in association with other substan oes. In such a mixture, the mineral has strong adhesion properties with a large specific surface of approximately 12 m2/g.
As a result, the mineral has utility as a component in various fields of application which are knc~n in the art. For exa~ple, the mineral is useful as a Eire-proofing compound, as its sintering point is in the region of 1260& while the melting point is in the region of 1350 C.
The mineral is also useful as a plant protection agent, and as a parting cc~pound.
This inccmbustible mineral is especially useful in the form of a film or coating. A property of the mineral is to form a film upon drying from a dispersion in a polar liquid, such as water. ~rying from a moistened or wetted dxy mass onto a surface results in a mass exhibiting dense particle packing and a small pore volume.
me naneral may also be used in expanded form, either as such or a~mixed with other substances. Various physical properties of the novel mineral are described hereinbelow, with referen oe to drawings which illus-trate these parameters.
Figure 1 is a graph of plasticity measurements, with curves drawn according to Pfefferkorn and Bcwmaker. The Gurves relate to (1) the mineral according to the invention in aqueous dispersion,
The structure and properties of vermiculite have been described in Romppls Chemie-Lexikon, Frankh'sche Verlagshandlung, Stuttgart, 7th Edition, heading 3000, as consisting of a composi-tion of the following formula: Mg3(Al,Si)4010(0H)2(H20)4. In addition vermiculite contains considerable quantities of combined iron (Fe).
"Hydro-micas" and "mixed-layer minerals" also have this ability to expand. The latter minerals also include those in which, for example, vermiculite laminations and mica laminations crystallize in alternating random sequence.
A description of the mineral starting material, vermicu-lite, can be found in "Mineralogical Tables", 5th Edition by Hugo Strunz (Leipzig 1970, Akademische Verlagsgesellschaft, Geest & Portig KG.) at page ~7.
A description of the mineral starting material, hydro-mica, can be found in "The Physical and Chemical Principles of Ceramics" by Salmang-Scholz (Springer Verlag, New York, 1968).
According to the present invention there is provided a reversibly swellable tri-laminar mineral which is crystalline over a large area, with the crystal layers separated from one another, characterized in that said tri-laminar mineral is produced from a ~Zt~53 fine-grain vermiculite, hydro-mica or mixed-layer mineral which incorporates non-swellable mica in intra-crystalline form between layers of said vermiculite or hydro-mica by swelling with a polar liquid and subsequent comminution into tabular particles; said mineral having more than 50 percent by weight of said tubular particles, having an extremely thin planar dimension with a thickness of from 0.5 to 10 microns and with surface dimensions corresponding to an equivalent diameter of from 10 to 200 microns and with a ratio between particle thickness and equivalent diameter equal to or smaller than 1:10, which particles are disposed substantially side by side in flat layers, and which particles demonstrate extensive plasticity when the water content of the mineral is from 35~ to 65~ by weight, said particles possessing hydrophilic properties on the planar surfaces thereof permitting the particles to quickly take up or give off polar liquids, and upon taking up a polar liquid, the particles swell, and upon giving off a polar liquid, the particles shrink, in a single direction which is perpendicular to the tubular plane of the particles.
The invention also provides a process for preparation of the mineral defined above, in which a fine-yrain vermiculite, hydro-mica or mixed-layer mineral is swelled with a polar liquid and subsequently meckanicallycomminuted, while preserving its structure, into extremely thin, uniformly planar, tubular particles.
The novel mineral according to the invention demonstrates various properties not found in the mineral starting compounds.
For example, the structure of the mineral results in strong adhesion and cohesion forces. The mineral exhibits a specific shrinkage behavior on being dried from a dispersion or upon being dried from moistenea or wetted dry mass. The surface dimensions , . .
~Z~4~3 of the tabular particles shrink in surface dimensions by 0.5 to 1.5% (length and breadth~ and in thickness by about 25% to 35%.
Generally the mineral when dried on a surface from a dispersion in a polar liquid, such as water, either by .itself or admixed with other substances, does not form any shrinkage cracks.
Many o~ the advantages of the mineral according to the - 2a -....
~Z64~53 invention are due to its inorganic composition and incombustibility. Among the technical advantages are included the use of the mineral as a binder in association with other substan oes. In such a mixture, the mineral has strong adhesion properties with a large specific surface of approximately 12 m2/g.
As a result, the mineral has utility as a component in various fields of application which are knc~n in the art. For exa~ple, the mineral is useful as a Eire-proofing compound, as its sintering point is in the region of 1260& while the melting point is in the region of 1350 C.
The mineral is also useful as a plant protection agent, and as a parting cc~pound.
This inccmbustible mineral is especially useful in the form of a film or coating. A property of the mineral is to form a film upon drying from a dispersion in a polar liquid, such as water. ~rying from a moistened or wetted dxy mass onto a surface results in a mass exhibiting dense particle packing and a small pore volume.
me naneral may also be used in expanded form, either as such or a~mixed with other substances. Various physical properties of the novel mineral are described hereinbelow, with referen oe to drawings which illus-trate these parameters.
Figure 1 is a graph of plasticity measurements, with curves drawn according to Pfefferkorn and Bcwmaker. The Gurves relate to (1) the mineral according to the invention in aqueous dispersion,
(2) fine grain vermiculite with a grain or particle size distribu-tion corresponding to composition (l) in aqueous dispersion,
(3) ]ean clay,
(4) fat clay.
Figuxe 2 is a graph of rheological properties of the mineral in aqueous dispersion at 20C, when measured by a rotary viscosimeter "Rheomat-15"* purchased from Contraves.
The procedure utilized for measuring plasticity is kncwn in the art, and described in the following literature:
*Trade mark 1~2ti453 DKG guiding principles, X/1969; definition, evaluation according to Pfefferkorn.
"Ceramics", Salmang/Scholze, pages 226-7: Principles of the rheology (5.2.1) pages 236/7: Methods of Pfefferkorn and of Bcwmaker.
The Bowm~ker curves which result are compared for the purpose of evaluating the results obtained by these measurements. A broad range of prac-tically constant plasticity exists if the Bowm~ker curve has a shallow path.
me range becomes narrower in proportion as each curve falls off more steeply.
Consequently, the steepness of the curve is a standard as regards the plasti-city; what is to be understood by "steepness" is the ratio between the differ-ence of the Bowmaker values and the difference of the water values x 1000.
Clays (3,4) provide a l-aw plasticity range. In aqueous dispersion, vermiculite (2) only shows a limited plasticity range under conditions of a very high water content. This large proportion of water leads to "bleeding"
fram the plastic mass.
The mineral according to the invention ll) exhibits a very broad plasticity range. m e water content is substantially smaller and the system is stable against ~leeding or exudation and sedimentation. For the m~neral according to the invention (1), the Bowmaker curve r~ns asymptotically with increase in water content. In the concentration range from 110 to 140 g H20/100 g of dry substanoe, the Bowmaker value is only changed frcm 8 to 6, corresponding to a steepness of 6.7.
The value for the starting material, vermiculite (2), in ~he same concentration range, shows a change in the Bowmaker value from 21.5 to 9, corresponding to a steepness of 417. With respect to plasticity then the parameters are very different for the startin~ material and for the new mineral according to the invention (1) which is produced therefrom. This difference is even greater when compared with the typical clays which were also measured in this way.
Figure 2 graphs the results upon measuring the rheological proper ~ ?
~6~.S3 ties of the mineral according to the invention in ccmparison with those of the starting material, vermiculite. Even with a low concentration of solids, the mineral according to the invention shows a high quasi-plastic capacity (see Salmang-Scholze, page 227). This is the reason why the mineral accord-ing to the invention only sediments slowly in contrast with the starting mate-rial, vermiculite, even when it contains a low con oentration of solids.
As an aqueous dispersion with a solids content of 20%, the mineral according to the invention shows a very steep curve of the shearing stress beyond the shearing speed D. When D = O sec 1, a shearing stress of ~ = 300 dyn/cm2 is produced. When D = 115 sec 1, the shearing stress reaches the value of ~ = 1000 dyn/cm2. The considerable value of ~ = 300 dyn/cm2 at the shearing stress D = O demonstrates the quasi-plastic properties of the sub-stance according to the invention.
Vermiculite, the starting material for the composition of curve 1 does not dem~nstrate these properties in an aqueous dispersion. With the same solids content of 20%, the function of ~ over D has a substantially m~re shallow curve. When D = O, ~ is likewise equal to O. It thus becomes clear that the vermi~ulite does not demonstrate any quasi-plastic behaviour. It is only when D = 700 sec that there is a shearing stress of ~ = 100 dyn/cm2.
The surprising rheological pr~perties of the new mineral according to the invention are the reason why this mineral, in the form of a paste and also in a flGwable form, is capable of being spread or sprayed to provide thin, uniform films. This potential is very suYprising in respect of an in-organic substan oe and is not obvious.
Wear resistance and adhesion strength of the dried mineral have ~264.~3 also been measured by the following procedure. The material to be investi-gated is applied from aqueous suspension onto a smooth surface, such as steel or window glass, and subsequently dried at 110C. In the dried state, the thickness o the layer or coating is 100 microns - 10%.
A cylindrical soft rubber element with a base area of 154 mm2, corresponding to a diameter of 1~ mm., is positioned on this coating. The rubber element is fixed to a metal rod. This is guided so that there is a slight degree of mobility in the perpendicular direction. The total load operating on the coating of substance to be tested amounts to 200 p., corres-ponding to a pressure of 130 p/cm2 The plate with the coating is shited backwards and forwards trans-versely of this load, always by 50 mm per second. Any possible change in the surface is ascertained after each displacement.
Measurement conditions:
Bearing pressure: 130 p/cm 2 Bearing area: soft rubber with 15~ mm Rubbing speed: 50 mm/sec.
Coating thickness: 100 microns - 10%
Support: bright steel sheet Table l _ Results Substance No. of rubbing Measurement investigated movements result p~ accor- 100 * No discoloration, .~P ; ding to the No wear, invention ~dried) good adhesion ~ermiculite 1 Discoloration, 16 coating completely worn away, defective adhesion Talcum l Discoloration, coating completely worn away, defective adhesion ~at clay 1 Discoloration, 29 coating completely worn away, defectlve adhesion 69~53 Table 1: _(continued) Lean clay O The film already lifts from the support with the drying, no adhesion.
*) The comparlson test was stopped after 100 rubbing movements. Up to this tin~e, no change on the surface and no decrease in weight ~ere detected.
Ater 100 rubbing movements, the substance according to the inven-tion does not show any discoloration or ~my visible or measureable signs of wear.
On the other hand, vermiculite, having the same grain particle size distribution, shows a strong discoloration and also a change in the surface after one rubbing move~nent. Ater 16 rubbing movements, the applied coating is already completely worn away.
n~
The ~YY~ H-}r~ according to the invention thus differs from the s~arting material as regards wear resistance as well as from other compari-son substances used industrially by virtue of an unexpected lac~ of disco-loration and also of the wear resistance found in practice and the good adhesion to the support.
Table 2: Results .
Measurement conditions: as with Table 1 Support: Window glass Substance No. of rubbing Measurement investigated movements result /~ih ~
ie~ according 100 * No discoloration, to the inven~ion no wear, good adhesion ~ermiculite 1 Discoloration, 19 Coating completely worn away, defective adhesion *) The comparison test was stopped aftar 100 rubbing movements. Up to ~his time, no change on the surface and no decrease in weight were detected.
The substance according to the invention, after 100 rubbing move-ments, shows the same, unaffected adhesion to the two chosen supports, namely, to the bright steel and to the clear glass. On the other hand, the starting vermiculite for production of the novel mineral according to the invention having the same grain or particle size distribution as the mineral of -the pre-sent invention/ shows a lack of adhesion after 19 rubbing movements on glass and with 16 rubbing movem~nts on steel, due to a wearing away frcm the support.
l'he difference in the resistance to wear is considerable. The new substance according to the invention shows practically no wear. On the other hand, the coating or layer of vermiculite is completely worn away after these ru~bing movements.
It is surprising that the new mineral according to the invention, as regards this parameter, presents entirely different properties from those of the starting material, vermiculite.
Further measurements of adhesion strength and wear resistance were carried out by the same procedure, but with the bearing pressure being successively increased until the applied coating or layer can be worn away with only one rubbing movement.
Table 3: Results Bearing Number of the rubbing movements until pressure the substance on the support is destroyed p/clr,2 _ Substance according Vermiculite to the invention .
After 100 rubbing movements, no deterioration in the adhesion of the mineral according to the invention to the support is found. This result is the same on bright steel as it is on glass.
With another series of measurements, using successively increased bearing pressure, no deterioration in the adhesion to the said supports was found with the nuneral according to the in-~ention, even with a bearing pres-sure of 1000 p/cm2 and 100 rubbing movements.
On the other hand, the starting material for the manufacture of -the mineral according to the invention, namely, vermic-~ite, practically the same with respect to grain or particle size distribution, is rubbed off after 16 rubbing movements on steel and after 19 rubbing movements on glass, with a bearing pL-essure of 130 p/cm in each case.
Vermiculite is rubbed off the support with the 4th rubbing ~ovement at a bearing pressure of 150 p/cm2, and with the first rubbiny movement at 200 p/cm .
The difference in the adhesion strength is considerable. The new mineral according to the invention shows a tight or firm adhesion to the selected support. This is still ~he case when the bearing pressure is in-creased by one power of ten.
On the contrary, the starting material for the production of the new mineral in accordance with the invention does not have any adhesion strenyth with the same support after only a few rubbing movem~nts with a low bearing pressure.
It is surprising that the new mineral according to the invention, as regards this parameter, shows entirely different properties from those of the starting material, which is vermiculite.
As confirmed by these comparative measurem~nts, the new nuneral according to the in~ention is different from its starting material, ~ermicu-lite, as rsgards the essential parameters of plasticity, the rheological pro-perties, the resistance to wear and the adhesion strength, when these p æ a-meters are tested using kncwn methods or usiny any defined method.
mis is applicable in like m~nner as regards hydro-mica, when used as starting material.
This discovery is based on the fact that the new mineral according to the invention has physical and chemical parameters which are different 2~53 ~n~a~
from those of the starting material from which this new c~mp~it-i-ff~ is produced in accordance with the process as disclosed or in accordance with other processes.
A preferred mineral ~ she~sn according to the invention does not form shrinkage cracks upon being dried onto a surface from a dispersion, either by itself or admixed Wit]l other substances, in a polar liquid~ The plasticity factor hl is 65.4393 - 1.32126.W ~ 1.03456. 10-2 w2 _ 2.80579.
10 5 W3 in the limits of 60 to 140 W, hl representing mm. in the Bowmaker scale and W representing g ~l20 / 100 g of dry weight. The shearing stress ~dyn/cm ) equals 277.861 + 16.7424D - 1.39397.10 D + 4.15845 D , and is an expression of its rheological properties in aqueous dispersion with a con-centration of 20% by weight at 20C., measured in a rotation viscosimeter, in the limits from zero to 140 D, D representing the shearing speed in sec 1, - 1 0 _
Figuxe 2 is a graph of rheological properties of the mineral in aqueous dispersion at 20C, when measured by a rotary viscosimeter "Rheomat-15"* purchased from Contraves.
The procedure utilized for measuring plasticity is kncwn in the art, and described in the following literature:
*Trade mark 1~2ti453 DKG guiding principles, X/1969; definition, evaluation according to Pfefferkorn.
"Ceramics", Salmang/Scholze, pages 226-7: Principles of the rheology (5.2.1) pages 236/7: Methods of Pfefferkorn and of Bcwmaker.
The Bowm~ker curves which result are compared for the purpose of evaluating the results obtained by these measurements. A broad range of prac-tically constant plasticity exists if the Bowm~ker curve has a shallow path.
me range becomes narrower in proportion as each curve falls off more steeply.
Consequently, the steepness of the curve is a standard as regards the plasti-city; what is to be understood by "steepness" is the ratio between the differ-ence of the Bowmaker values and the difference of the water values x 1000.
Clays (3,4) provide a l-aw plasticity range. In aqueous dispersion, vermiculite (2) only shows a limited plasticity range under conditions of a very high water content. This large proportion of water leads to "bleeding"
fram the plastic mass.
The mineral according to the invention ll) exhibits a very broad plasticity range. m e water content is substantially smaller and the system is stable against ~leeding or exudation and sedimentation. For the m~neral according to the invention (1), the Bowmaker curve r~ns asymptotically with increase in water content. In the concentration range from 110 to 140 g H20/100 g of dry substanoe, the Bowmaker value is only changed frcm 8 to 6, corresponding to a steepness of 6.7.
The value for the starting material, vermiculite (2), in ~he same concentration range, shows a change in the Bowmaker value from 21.5 to 9, corresponding to a steepness of 417. With respect to plasticity then the parameters are very different for the startin~ material and for the new mineral according to the invention (1) which is produced therefrom. This difference is even greater when compared with the typical clays which were also measured in this way.
Figure 2 graphs the results upon measuring the rheological proper ~ ?
~6~.S3 ties of the mineral according to the invention in ccmparison with those of the starting material, vermiculite. Even with a low concentration of solids, the mineral according to the invention shows a high quasi-plastic capacity (see Salmang-Scholze, page 227). This is the reason why the mineral accord-ing to the invention only sediments slowly in contrast with the starting mate-rial, vermiculite, even when it contains a low con oentration of solids.
As an aqueous dispersion with a solids content of 20%, the mineral according to the invention shows a very steep curve of the shearing stress beyond the shearing speed D. When D = O sec 1, a shearing stress of ~ = 300 dyn/cm2 is produced. When D = 115 sec 1, the shearing stress reaches the value of ~ = 1000 dyn/cm2. The considerable value of ~ = 300 dyn/cm2 at the shearing stress D = O demonstrates the quasi-plastic properties of the sub-stance according to the invention.
Vermiculite, the starting material for the composition of curve 1 does not dem~nstrate these properties in an aqueous dispersion. With the same solids content of 20%, the function of ~ over D has a substantially m~re shallow curve. When D = O, ~ is likewise equal to O. It thus becomes clear that the vermi~ulite does not demonstrate any quasi-plastic behaviour. It is only when D = 700 sec that there is a shearing stress of ~ = 100 dyn/cm2.
The surprising rheological pr~perties of the new mineral according to the invention are the reason why this mineral, in the form of a paste and also in a flGwable form, is capable of being spread or sprayed to provide thin, uniform films. This potential is very suYprising in respect of an in-organic substan oe and is not obvious.
Wear resistance and adhesion strength of the dried mineral have ~264.~3 also been measured by the following procedure. The material to be investi-gated is applied from aqueous suspension onto a smooth surface, such as steel or window glass, and subsequently dried at 110C. In the dried state, the thickness o the layer or coating is 100 microns - 10%.
A cylindrical soft rubber element with a base area of 154 mm2, corresponding to a diameter of 1~ mm., is positioned on this coating. The rubber element is fixed to a metal rod. This is guided so that there is a slight degree of mobility in the perpendicular direction. The total load operating on the coating of substance to be tested amounts to 200 p., corres-ponding to a pressure of 130 p/cm2 The plate with the coating is shited backwards and forwards trans-versely of this load, always by 50 mm per second. Any possible change in the surface is ascertained after each displacement.
Measurement conditions:
Bearing pressure: 130 p/cm 2 Bearing area: soft rubber with 15~ mm Rubbing speed: 50 mm/sec.
Coating thickness: 100 microns - 10%
Support: bright steel sheet Table l _ Results Substance No. of rubbing Measurement investigated movements result p~ accor- 100 * No discoloration, .~P ; ding to the No wear, invention ~dried) good adhesion ~ermiculite 1 Discoloration, 16 coating completely worn away, defective adhesion Talcum l Discoloration, coating completely worn away, defective adhesion ~at clay 1 Discoloration, 29 coating completely worn away, defectlve adhesion 69~53 Table 1: _(continued) Lean clay O The film already lifts from the support with the drying, no adhesion.
*) The comparlson test was stopped after 100 rubbing movements. Up to this tin~e, no change on the surface and no decrease in weight ~ere detected.
Ater 100 rubbing movements, the substance according to the inven-tion does not show any discoloration or ~my visible or measureable signs of wear.
On the other hand, vermiculite, having the same grain particle size distribution, shows a strong discoloration and also a change in the surface after one rubbing move~nent. Ater 16 rubbing movements, the applied coating is already completely worn away.
n~
The ~YY~ H-}r~ according to the invention thus differs from the s~arting material as regards wear resistance as well as from other compari-son substances used industrially by virtue of an unexpected lac~ of disco-loration and also of the wear resistance found in practice and the good adhesion to the support.
Table 2: Results .
Measurement conditions: as with Table 1 Support: Window glass Substance No. of rubbing Measurement investigated movements result /~ih ~
ie~ according 100 * No discoloration, to the inven~ion no wear, good adhesion ~ermiculite 1 Discoloration, 19 Coating completely worn away, defective adhesion *) The comparison test was stopped aftar 100 rubbing movements. Up to ~his time, no change on the surface and no decrease in weight were detected.
The substance according to the invention, after 100 rubbing move-ments, shows the same, unaffected adhesion to the two chosen supports, namely, to the bright steel and to the clear glass. On the other hand, the starting vermiculite for production of the novel mineral according to the invention having the same grain or particle size distribution as the mineral of -the pre-sent invention/ shows a lack of adhesion after 19 rubbing movements on glass and with 16 rubbing movem~nts on steel, due to a wearing away frcm the support.
l'he difference in the resistance to wear is considerable. The new substance according to the invention shows practically no wear. On the other hand, the coating or layer of vermiculite is completely worn away after these ru~bing movements.
It is surprising that the new mineral according to the invention, as regards this parameter, presents entirely different properties from those of the starting material, vermiculite.
Further measurements of adhesion strength and wear resistance were carried out by the same procedure, but with the bearing pressure being successively increased until the applied coating or layer can be worn away with only one rubbing movement.
Table 3: Results Bearing Number of the rubbing movements until pressure the substance on the support is destroyed p/clr,2 _ Substance according Vermiculite to the invention .
After 100 rubbing movements, no deterioration in the adhesion of the mineral according to the invention to the support is found. This result is the same on bright steel as it is on glass.
With another series of measurements, using successively increased bearing pressure, no deterioration in the adhesion to the said supports was found with the nuneral according to the in-~ention, even with a bearing pres-sure of 1000 p/cm2 and 100 rubbing movements.
On the other hand, the starting material for the manufacture of -the mineral according to the invention, namely, vermic-~ite, practically the same with respect to grain or particle size distribution, is rubbed off after 16 rubbing movements on steel and after 19 rubbing movements on glass, with a bearing pL-essure of 130 p/cm in each case.
Vermiculite is rubbed off the support with the 4th rubbing ~ovement at a bearing pressure of 150 p/cm2, and with the first rubbiny movement at 200 p/cm .
The difference in the adhesion strength is considerable. The new mineral according to the invention shows a tight or firm adhesion to the selected support. This is still ~he case when the bearing pressure is in-creased by one power of ten.
On the contrary, the starting material for the production of the new mineral in accordance with the invention does not have any adhesion strenyth with the same support after only a few rubbing movem~nts with a low bearing pressure.
It is surprising that the new mineral according to the invention, as regards this parameter, shows entirely different properties from those of the starting material, which is vermiculite.
As confirmed by these comparative measurem~nts, the new nuneral according to the in~ention is different from its starting material, ~ermicu-lite, as rsgards the essential parameters of plasticity, the rheological pro-perties, the resistance to wear and the adhesion strength, when these p æ a-meters are tested using kncwn methods or usiny any defined method.
mis is applicable in like m~nner as regards hydro-mica, when used as starting material.
This discovery is based on the fact that the new mineral according to the invention has physical and chemical parameters which are different 2~53 ~n~a~
from those of the starting material from which this new c~mp~it-i-ff~ is produced in accordance with the process as disclosed or in accordance with other processes.
A preferred mineral ~ she~sn according to the invention does not form shrinkage cracks upon being dried onto a surface from a dispersion, either by itself or admixed Wit]l other substances, in a polar liquid~ The plasticity factor hl is 65.4393 - 1.32126.W ~ 1.03456. 10-2 w2 _ 2.80579.
10 5 W3 in the limits of 60 to 140 W, hl representing mm. in the Bowmaker scale and W representing g ~l20 / 100 g of dry weight. The shearing stress ~dyn/cm ) equals 277.861 + 16.7424D - 1.39397.10 D + 4.15845 D , and is an expression of its rheological properties in aqueous dispersion with a con-centration of 20% by weight at 20C., measured in a rotation viscosimeter, in the limits from zero to 140 D, D representing the shearing speed in sec 1, - 1 0 _
Claims (16)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A reversibly swellable tri-laminar mineral which is crystalline over a large area, with the crystal layers separated from one another, characterized in that said tri-laminar mineral is produced from a fine-grain vermiculite, hydro-mica, or mixed-layer mineral which incorporated non-swellable mica in intra-crystalline form between layers of said vermiculate or hydro-mica by swelling with a polar liquid and subsequent comminution into tabular particles; said mineral having more than 50 percent by weight of said tabular particles, having an extremely thin planar dimension with a thickness of from 0.5 to 10 microns and with surface dimensions corresponding to an equivalent diameter of from 10 to 200 microns and with a ratio between particle thickness and equivalent diameter equal to or smaller than 1:10, which particles are disposed substantially side by side in flat layers, and which particles demonstrate extensive plasticity when the water content of the mineral is from 35% to 65% by weight, said particles possessing hydrophilic properties on the planar surfaces thereof permitting the particles to quickly take up or give off polar liquids, and upon taking up a polar liquid, the particles swell, and upon giving off a polar liquid, the particles shrink, in a single direction which is perpendicular to the tabular plane of the particles.
2. A process for preparation of the mineral of claim 1, in which a fine-grain vermiculite, hydro-mica or mixed-layer mineral is swelled with a polar liquid and subsequently mechanically comminuted, while preserving its structure, into extremely thin, uniformly planar, tabular particles.
3. A process according to claim 2, in which the polar liquid is water.
4. A mineral according to claim 1, in which the tabular particles constitute more than 75% by weight of the mineral.
5. A mineral according to claim 1, in which the tabular particles have a thickness of from 0.5 to 5 microns.
6. A mineral according to claim 1, in which the tabular particles have a ratio between particle thickness and equivalent diameter equal to or smaller than 1:20.
7. The reversibly swellable tri-laminar mineral of claim 1 having a plasticity factor h-1 of from about 65.4393-1.32126.
W+1.03456. 10-2W2-2.80579. 10-5W3 in the limits of from about 60 to about 140W with h1 representing mm. on the Bowmaker scale and W representing g H20/100g of dry substance.
W+1.03456. 10-2W2-2.80579. 10-5W3 in the limits of from about 60 to about 140W with h1 representing mm. on the Bowmaker scale and W representing g H20/100g of dry substance.
8. The reversibly swellable tri-alminar mineral of claim 1 having a shearing stress (dyn/cm ) equalling at least about 277.861 + 16.7424D - 1.39397.10-1D2 + 4.15845 D3, as an expression of the rheological properties thereof in aqueous dispersion at a concentration of about 20% by weight and at 20°C., measured by a rotation viscosimeter, in the limits from zero to 140 D with D
representing the shearing speed in sec-l.
representing the shearing speed in sec-l.
9. The reversibly swellable tri-laminar mineral of claim l which, following drying on the surfaces thereof from a dispersion in a polar liquid, does not show any shrinkage cracks.
10. The reversibly swellable tri-laminar mineral of claim 1 forming a mass with dense particle packing and a small pore volume upon drying of the surfaces thereof.
11. The reversibly swellable tri-laminar mineral of claim 1 wherein the ratio of particle thickness to equivalent diameter of said tabular particles is smaller than about 1:400.
12. The reversibly swellable tri-laminar mineral of claim 1 in the expanded state with further polar liquid.
13. The reversibly swellable tri-laminar mineral of claim 1 which, in the dry state, shows a shrinkage of the tabular particles with respect to the length and breadth thereof of from about 0.5 to about 1.5%, and with respect to the thickness thereof, of from about 25% to about 35%.
14. A process for preparing the mineral composition of claim 1 which comprises contacting a fine-grain crystalline mineral selected from the group consisting of vermiculite, hydro-mica and a mixed layer mineral, with a polar liquid to swell the mineral, and comminuting the swollen mineral under conditions preserving its crystalline structure to provide a mineral having substantially thin, uniformly planar, tabular particles, the plasticity h1 of said mineral being about 65.4393 - 1.32126. W + 1.03455. 10-2 W2 - 2.80579. 10-5 W3 in the limits of about 60 to about 140 W with h-1 representing mm.
on the Bowmaker scale and W representing g H20/100 g of dry substance.
on the Bowmaker scale and W representing g H20/100 g of dry substance.
15. The process of claim 14 wherein the polar liquid is water.
16. The process of claim 14 wherein the swollen mineral is comminuted to provide a mineral having a shearing stress (dyn/cm2) of at least about 277.861 + 16.742D - 1.39397. 10-1 D2 +
4.15845 D3 as an expression of the rheological properties thereof in aqueous dispersion at a concentration of about 20% by weight at 20°C. measurea by a rotation viscosimeter in the limits from 0 to 140 D with D representing the shearing speed in sec 1.
4.15845 D3 as an expression of the rheological properties thereof in aqueous dispersion at a concentration of about 20% by weight at 20°C. measurea by a rotation viscosimeter in the limits from 0 to 140 D with D representing the shearing speed in sec 1.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2731204A DE2731204C3 (en) | 1977-07-11 | 1977-07-11 | Reversibly swellable, large-area crystalline three-layer mineral with separated crystal layers and with strong adhesion and cohesion forces and process for its production |
| DEP2731204.5-41 | 1977-07-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1126453A true CA1126453A (en) | 1982-06-29 |
Family
ID=6013619
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA307,094A Expired CA1126453A (en) | 1977-07-11 | 1978-07-10 | Mineral substance based on a reversibly swellable tri-laminar mineral developed to be crystalline over a large area and having crystal layers separated from one another |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS585869B2 (en) |
| AT (1) | AT376415B (en) |
| BR (1) | BR7804458A (en) |
| CA (1) | CA1126453A (en) |
| DE (1) | DE2731204C3 (en) |
| ES (1) | ES471622A1 (en) |
| IT (1) | IT1105733B (en) |
| ZA (1) | ZA783956B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2849177C3 (en) * | 1978-11-13 | 1982-04-08 | Hans Kramer GmbH & Co KG, 4000 Düsseldorf | Process for the production of a reversibly swellable, large-area crystalline three-layer mineral with crystal layers separated from one another |
| US4239519A (en) * | 1979-03-26 | 1980-12-16 | Corning Glass Works | Inorganic gels and ceramic papers, films, fibers, boards, and coatings made therefrom |
| DE3029877C1 (en) * | 1980-08-07 | 1981-10-08 | Ekoperl Gmbh, 4600 Dortmund | Process for producing an O absorbent |
| JPS60175182U (en) * | 1984-04-06 | 1985-11-20 | 篠原 二郎 | pillow |
| EP0375693A1 (en) * | 1987-07-10 | 1990-07-04 | Raychem Limited | Chemically delaminated mica containing mineral |
| DE4231877C1 (en) * | 1992-09-23 | 1994-01-13 | Christian Klepsch | Temp.-resistant highly loadable lightweight building material prodn. - by mixing mica with small amt. of binder and solvent, moulding and drying, for use as fireproof roof bearer, door or panel or boat |
| GB9704560D0 (en) * | 1997-03-05 | 1997-04-23 | T & N Technology Ltd | Release agent |
| CN104505644B (en) * | 2014-12-08 | 2017-01-04 | 周口市凯旺电子科技有限公司 | A kind of high-speed transfer cylindrical connector |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2405576A (en) * | 1943-06-03 | 1946-08-13 | Integrated Mica Corp | Integrated mica and method of making the same |
| US3325340A (en) * | 1961-12-22 | 1967-06-13 | Commw Scient Ind Res Org | Suspensions of silicate layer minerals and products made therefrom |
| US3434917A (en) * | 1966-03-07 | 1969-03-25 | Grace W R & Co | Preparation of vermiculite paper |
| US3608835A (en) * | 1967-06-30 | 1971-09-28 | Josef Ruzicka | Ultradisintegration and agglomeration of minerals such as mica, products therefrom and apparatus therefor |
| JPS4851876A (en) * | 1971-11-01 | 1973-07-20 | ||
| JPS545398B2 (en) * | 1973-01-13 | 1979-03-16 | ||
| NO146134C (en) * | 1976-09-23 | 1982-08-04 | Ici Ltd | PROCEDURE FOR THE MANUFACTURE OF FORMED ARTICLES OF VERMICULITE |
-
1977
- 1977-07-11 DE DE2731204A patent/DE2731204C3/en not_active Expired
-
1978
- 1978-07-10 JP JP53083106A patent/JPS585869B2/en not_active Expired
- 1978-07-10 IT IT50227/78A patent/IT1105733B/en active
- 1978-07-10 CA CA307,094A patent/CA1126453A/en not_active Expired
- 1978-07-11 ES ES471622A patent/ES471622A1/en not_active Expired
- 1978-07-11 ZA ZA00783956A patent/ZA783956B/en unknown
- 1978-07-11 AT AT0499378A patent/AT376415B/en not_active IP Right Cessation
- 1978-07-11 BR BR7804458A patent/BR7804458A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| DE2731204A1 (en) | 1979-01-18 |
| JPS585869B2 (en) | 1983-02-02 |
| ATA499378A (en) | 1984-04-15 |
| IT1105733B (en) | 1985-11-04 |
| ZA783956B (en) | 1979-10-31 |
| DE2731204B2 (en) | 1980-07-31 |
| JPS5434323A (en) | 1979-03-13 |
| DE2731204C3 (en) | 1981-11-05 |
| AT376415B (en) | 1984-11-26 |
| BR7804458A (en) | 1979-05-02 |
| IT7850227A0 (en) | 1978-07-10 |
| ES471622A1 (en) | 1979-12-16 |
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