KR910002888B1 - Water swellable clay composition - Google Patents

Abstract

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Description

Water swellable clay composition and its manufacturing method

1 is a schematic diagram of a device used in the manufacture of the compositions and products of the present invention.

2 is a perspective view of the composition of the present invention molded into an elongated rectangular shape.

3 is a perspective view of a rectangular block of the present invention composition just before hydration.

4 is a perspective view showing the composition block of FIG. 3 after hydration;

FIG. 5 is a partially exploded perspective view of the device and composition used to manufacture the product of FIG. 6. FIG.

6 is a partially exploded perspective view of the sheet product of the present invention.

* Explanation of symbols for main parts of the drawings

14: Sigma Blender 16: Extruder

20: die hole 22: rope

24: conveyor 30: release paper

32: Take upside down.

The present invention is a tacky, fully expandable, non-hydrated bentonite composition that can expand under hydration from all water contact surfaces to a new and improved method while maintaining the tack integrity of the bentonite composition. It is about

More particularly, the present invention provides a non-aqueous bentonite composition that can form a particularly useful shape as a water barrier, in one embodiment with unhydrated bentonite in intimate contact with polypropene, polybutene or mixtures thereof. It is composed.

Bentonite compositions can be extruded in the form of ropes, rods, sheets, etc. and have sufficient viscosity for adhesion to walls, conduits, floors or loops in the potential flow zone to prevent leakage through the bentonite compositions.

In one embodiment, the bentonite composition comprises an elastomer, such as a butting rubber, that has sufficient elasticity to expand the expanding bentonite under hydration and to assist in maintaining structural integrity and tackiness of the composition. Many attempts have been made to provide bentonite compositions with sufficient adhesion and structural integrity to provide consistency such as modeling clay or putty.

These bentonite compositions are easy to handle so that the desired amount can be applied at selected locations for leak control.

It can be in the form of a paste or putty. The main problem associated with attempting to provide bentonite compositions with consistency, such as paste (or putty), to provide the desired ease of handling is that many additives used to provide such consistency interfere with the swelling capacity of bentonite. One attempt to provide a bentonite composition with a consistency such as putty is described in Bechtner's US Pat. No. 2,277,286, where water was added to bentonite to hydrate a portion of bentonite to achieve the desired consistency. The resultant composition is a sufficiently sticky putty-like material as a result of partial swelling of bentonite, and the swelling properties of bentonite have been sufficiently delayed because potentyl absorption and swelling properties of about 70-80% are maintained.

Furthermore, the Bechtner material will adhere to the surface as long as moisture is maintained. The addition of a non-aqueous liquid, as described in the assignee's prior patent 4,279,547 and McGroati's patent 4,316,833, maintains the ease of handling in the form of a paste (or putty) while maintaining the complete swelling properties of bentonite. There has been another attempt to provide bentonite compositions having.

Generally, adding liquid organic additives to bentonite suppresses the swelling capacity of bentonite to varying degrees depending on the nature of the organic additives, in particular on the polarity of the organic additives. Attempts by McGroati's patent 4,316,833 provide adhesive bentonite compositions having a paste-like consistency without hydrating bentonite by addition of an adhesive, such as a hydrocarbon resin.

According to McGroati's Patent No. 4,316,833, when the adhesive penetrates bentonite, the swelling capacity of bentonite is destroyed, thereby destroying algebra.

In an attempt to prevent adhesive penetration, McGroati's bentonite is first saturated with liquid fluidizing agents, such as mineral spirts, and prevents the adhesive from penetrating bentonite particles after saturation.

The assignee's prior art patent 6,279,547 does not saturate bentonite with organics that inhibit bentonite by adding bentonite to the gel to prevent bentonite saturation without hydrating bentonite and forming a gel and maintaining its swelling properties. Another attempt is described to provide bentonite compositions having a consistency that is easy to handle, such as hard putty.

Ishido Patent No. 4,366,284 describes bentonite compositions having 10-40% of rubber, 10-40% of plasticizer and siliceous layered agent.

At least 10% by weight siliceous layer is a threshold for swelling. According to one embodiment of the present invention, the composition of the present invention is capable of achieving increased swelling, as long as the composition does not necessarily contain a silicate filler.

The compositions described in the assignee's prior patents 4,279,547 and McGroati patents 4,316,833 generally suppress swelling of bentonite by the swelling composition consistency and retention.

According to the present invention, bentonite intimately mixed with polypropene, polybutene or a mixture thereof has the same consistency as the paste (or putty); Bentonite compositions with sufficient adhesion to the extent that they are attached to walls, floors, loops, conduits and the like are formed, and the swelling capacity of bentonite is increased to the most controversial and unexpected degree. Briefly, the present invention relates to an unhydrated bentonite composition, which in one embodiment consists of an intimate mixture of polypropene, polybutene or a mixture thereof and bentonite clay.

In another embodiment of the present invention, elastomers such as partially crosslinked butyl rubber are included in the clay composition. The elastomer has sufficient elasticity to swell the hydration difference of bentonite and add structural integrity to the bentonite composition.

With and without elastomer, the compositions of the present invention comprise at least 10% by weight of polypropene or polybutene to provide more swelling capacity than that of bentonite alone.

After forming an intimate mixture of polypropene, polybutene or a mixture thereof and bentonite, additional additives such as a tackifier, a viscosity modifier, a thickening agent, a cooperative agent, and the like are added. Polypropene and / or polybutene give the bentonite composition a tacky adhesion and remove the moisture of the clay under initial intimate mixing to prevent the bentonite inhibitor additive from inhibiting the swelling properties of bentonite.

Moreover, the polypropene and / or polybutene components of the compositions of the present invention do not dry out over a period of time other than to provide an increase in swelling capacity of the new and improved bentonite.

In addition, the capacity of polypropene and polybutene for water removal of bentonite allows the formation of bentonite compositions containing 85-90% bentonite with l0-l5% polypropylene and / or bolibuten. The sticky handling of the composition is maintained.

According to another embodiment of the present invention, the composition comprises water swellable clay such as bentonite, an elastomer such as partially crosslinked butyl rubber, and a plasticizer that does not react with the elastomer. The elastomer can stretch the clay under hydration.

It is therefore an object of the present invention to provide an unhydrated tacky bentonite composition containing bentonite clay, polypropene and / or polybutene having a novel and improved swelling capacity.

Yet another object is to provide a process for the preparation of unhydrated tacky bentonite compositions containing bentonite clay, polypropene and / or polybutene with new and improved swelling capacity.

Yet another object is to provide new and improved structural integrity of unhydrated sticky bentonite compositions for the production of ropes or other desired forms comprising bentonite, polypropene and / or polybutene and elastomers.

Yet another object is to provide a process for the preparation of unhydrated sticky bentonite compositions with new and improved structural integrity for the production of ropes or other desired forms comprising bentonite, polypropene and / or polybutene and elastomers. .

Another object is to provide a product consisting of 35-90% by weight bentonite, 10-65% by weight polypropene, polybutene or mixtures thereof.

Still another object is to provide a bentonite elastomer composition and a process for producing a bentonite elastomer composition comprising bentonite, an elastomer and a plasticizer that does not react with the elastomer (which results in a composite product having extremely good structural integrity where water swellable clay is hardly inhibited from swelling). It is.

According to the present invention, water-swellable clays intimately mixed with polypropene, polybutene or mixtures thereof have a desired consistency ranging from liquids such as scoops to cohesive solids such as relatively hard putty and are novel and improved. Provided is a bentonite composition having a swelling capacity.

Water swellable clays such as bentonite are included in the composition in an amount of about 35-90% by weight, and polypropene and / or polybutene are included in the composition in an amount of about 10-65% by weight.

In order to achieve the full advantage of the present invention, the composition should contain at least 15% by weight of polypropene, polybutene or mixtures thereof. Additional tackifiers that do not react with polypropene or polybutene may be included for additional tack as long as polypropene, polybutene or a mixture thereof is included in at least 10% by weight of the composition.

The tackifiers include, for example, aliphatic petroleum hydrocarbon resins such as polyisobutylene, polyterpenes, hydrogenated resins and mixed olefins. In general, aromatic tackifiers are inadequate because they leak and separate on the surface of the composition, thereby reducing ease of handling and consistency of the composition.

Other additives such as viscosity modifiers, fillers, tackifiers and the like are added in total amounts of up to about 20% by weight of the bentonite composition to impart the desired physical properties to the clay composition.

However, it was found that the addition of a silicate filler, i.e., silicic acid or calcium silicate, reduced the water swellability of the clay composition of the present invention.

Therefore, the silicate filler does not necessarily need to be added to the composition. When only 1% by weight of siliceous filler is added to the composition, the water swellability of the composition is reduced by about 10%.

When 5% by weight of silicate filler is added to the composition, the water swellability of the composition is reduced by about 20%.

In order to achieve the full advantage of the present invention, the silicate filler may be within 1% by weight of the water-swellable clay composition layer.

Medium solvents, such as inorganic spirits, are added to the compositions of the present invention for adjuvant mixing, but it is preferred to combine the clay composition components without such solvents.

In any case, polypropene, polybutene or mixtures thereof should be present in the final composition in an amount of at least 10% by weight after evaporation of the solvent which can volatilize under ambient conditions.

According to an important feature of the present invention, the additives can be used to remove the water of bentonite in an amount of up to about 90% by weight bentonite without inhibiting the swelling properties of bentonite. It is not necessary to protect the swellable clay, polypropene and / or polybutene compositions.

Unexpectedly, the polypropene and / or polybutene component increases the swelling capacity of bentonite, while imparting sufficient fixation to allow the composition to easily settle on almost any surface over an extended period of time.

The water swellable cladding clays used in the present invention are all water swellable colloidal clays that can hydrate in the presence of water, ie, swell in the presence of water.

According to one important embodiment of the invention, the colloidal clay is bentonite. Bentonite is preferably sodium bentonite, a form of water-soluble montmorillonite clay found generally in the Black Hills region of Saud Dagota and Wyoming. This clay has sodium as its main exchange ion. However, the bentonite used by this embodiment of the present invention also contains magnesium and the resulting cations.

Here, montmorillonite, which is the major calcium ion, can be converted into a high swelling sodium variant through known "peptizing" methods. The colloidal clay used in the present invention is at least one peptized bentonite. Colloidal clays are also members of dioctahedral or trioctahedral smectite groups or mixtures thereof. Examples are Weidelite, nontronite, hectorite and saponite.

In general, colloidal clay, that is, bentonite, is finely divided into 150-350 mesh, as used in water barrier panels and the like.

By the principles of the present invention, the polybutenes used generally consist of (C ₄ H ₈ ) _n , where n is about 3-45, with an average molecular weight of about 300-2500.

Commercially useful polybutenes consist primarily of high molecular weight mono-olefins and comprise 100% polybutene or up to about 10% isoparaffin. Polybutenes are chemically stable fluids, and their adhesion increases with increasing molecular weight.

The viscosity of the polybutenes ranges from the consistency of the diesel to the highly viscous fluids having a viscosity of about 25-4,000 centipoise.

Low viscosity polybutenes can be combined with water swellable clays to provide compositions that are highly tacky and have a scoop-like consistency that is difficult to handle depending on the amount of bentonite contained in the compositions of the present invention.

Polypropenes useful by the principles of the present invention generally consist of (C ₃ H ₆ ) _n , where n is about 7-60, having a molecular weight of about 300-2,500.

The commercially available polypropenes of the present invention are generally amorphous and may be combined with up to about 10% by weight of a suitable treating solvent such as liroin, and moreover, polypropenes are readily free from bentonite at elevated temperatures, i.e. at 200 ° C, without solvents. Sometimes mixed.

In order to achieve significant swelling of the composition of the present invention, polypropene or polybutene or mixtures thereof should be present in the composition in an amount of about l5-30% by weight of the total composition. In the test to determine whether polypropene and polybutene inhibit the swelling properties of water swellable clay, two compositions were prepared according to the present invention, the first containing approximately 78% bentonite and 22% polybutene and the second side about 78 It contains% bentonite and 22% plypropene.

For comparison, 1 g of bentonite is left in the first meter cylinder and 1 g of the two compositions of the present invention are left in a second and third meter cylinder.

Wet each composition and allow it to swell for about 48 hours. After complete swelling the bentonite swelled to a volume of about 9 ml and the two compositions of the invention containing polypropene or polybutene swelled to a volume of 10 ml.

According to another important feature of the present invention, the addition of the elastomer in an amount of about 1-20% based on the total weight of the bentonite composition of the present invention increases the ease of handling the composition without disturbing its swelling properties. .

In order to achieve the full benefit of this embodiment of the present invention, the elastomer should be included in an amount of about 2-10% by weight based on the total weight of the composition.

Surprisingly, the mastication containing water-swellable clays such as bentonite, polypropene and / or polybutene and elastomers (ie, in sigma branders) swell in greater amounts than bentonite clay alone; And it was found that the capacity of the composition was increased to swell a greater amount of bentonite, polypropene / polybutene composition bob than without elastomer. In the swelling test of the bentonite compositions of the present invention comprising an elastomer, the two compositions prepared above (polybutene and polypropene) were separately mixed in a sigma blender containing 4.95% of partially crosslinked butyl rubber. The butyl rubber is completely soaked with the composition to form two uniform blenders.

Each composition lg containing 4.95% butyl rubber, 75.25% bentonite clay and 19.8% polybutene or polypropene is left in two meter cylinders and soaked in water for approximately 48 hours to confirm that the composition is fully swelled. When fully swollen, 1 g of each composition containing butyl rubber swelled approximately 13-14 ml, ie the swelling caused by 1 gh of bentonite, greater than the swelling caused by bentonite / polypropene or bentonite / polybutene composition, and moreover. These compositions contained more bentonite without elastomers.

Compositions containing butyl rubber could be easily handled and extruded into the desired shape and retained its shape when attached to a surface for leak control.

According to an important feature of the present invention, all elastomers having at least 100% elongation and at least 500% elongation can be used in the bentonite compositions of the present invention to improve handling, adhesiveness and structural integrity of the composition.

While it has been found that partially crosslinked elastomers are most suitable for improving the consistency, ease of handling and structural integrity of products requiring these properties, uncrosslinked elastomers are also useful, in particular the polymers in Sigma blenders in the USSR. It can be cross-linked slightly when subjected to what has happened in and can be mixed with other clay composition components.

In general, fully crosslinked elastomers are not suitable for binding to the compositions of the present invention because their elongation is insufficient to allow full expansion of bentonite upon hydration.

However, all elastomers having at least 100% elongation are described in the present invention and are included within the scope of the present invention.

In order to achieve the full advantage of the present invention, the elastomers are at least to allow for the novel and improved clay swelling found by the principles of the inventive embodiments relating to intimate contact of bentonite with polypropene and / or polybutene. Has an elongation of 500%. Another elastomer includes polyisobutylene.

Suitable elastomers for bonding to the composition are styrene-butadiene, synthetic and natural rubber, ethylene-propylene copolymers and terpolymers, butyl halide rubbers, and divinyls added to form terpolymers for the purpose of imparting a degree of "curing". Partially crosslinked butyl rubber with benzene. The elastomer may be torn by bentonite and polypropene and / or polybutene to reduce the mixing time prior to the Soviet Union, but the tearing process of the elastomer is unnecessary.

Soviet and homogeneous flow of the elastomer through the bentonite composition can be achieved using the elastomer in a sigma blender in the desired form, ie in the annular form. According to another important feature of the present invention, bentonite compositions may include additives capable of forming the epidermis in the composition, such as a copolymer of vegetable dry oil and vinyltoluene.

Compositions comprising the epidermis are useful where the composition does not require tack to hold the composition in place. If tack is required, all suitable tackifier surface coatings are applied on the epidermis.

According to another embodiment of the present invention, a water swellable composition is provided, which composition is based on the total weight of the composition, 35-90% by weight of bentonite, 1-20% by weight of the elastomer, and the elastomer without reacting with the elastomer. 2-50% by weight of plasticizer which can be plasticized.

The plasticizer improves the processability of the elastomer, elongates the elastomer and repositions the elastomer itself by expansion of the water-swellable clay when the clay is wetted so that the elastomer wets the bentonite surface to accommodate up to about 90% bentonite, and the composition To provide a uniform bentonite distribution through the elastomer.

It has been found that bentonite is fully expanded under water contact by an elastomer having at least 100% elongation, as long as the elastomer comprises at least 2% plasticizer based on the weight of the composition. Elastomers provide exceptional structural integrity to the composition without exceptionally inhibiting swelling of the clay.

Elastomers are partially crosslinked and include butyl rubber, styrene-butadiene, other synthetic and natural rubber, ethylene-propylene copolymers, ethylene and propylene terpolymers.

Suitable plasticizers include epoxidized oils such as epoxidized soybean oil; Alkyl mono esters such as butyl oleate; Long-chain moiety esters such as butyl cellosolve oleate; Relatively low polar plasticizers comprising long chain alkyl diesters such as dioctyl adipate and dioctyl phthalate; Aromatic naphthenic oils; Naphthene-aromatic oils; Plasticizers prepared from petroleum such as naphthene-paraffinic oil and paraffinic oil.

In order to achieve the full advantage of this embodiment of the present invention, the plasticizer is included in the composition in an amount of at least 10% by weight of the composition to plasticize the elastomer and completely remove the moisture of the bentonite. Plasticizers generally comprise 10-30%.

Referring to the drawings, the apparatus of FIGS. 1-5 shows a schematic diagram of extruding the composition of the present invention into rod and sheet form.

In one embodiment, the bentonite composition 12 consisting of an intimate mixture of polypropene and / or polybutene and bentonite, or in another embodiment a plasticizer and an intimate mixture of bentonite, is butyl rubber in a sigma blender 14. The elastomer is completely crushed to blend completely with an elastomer such as to provide a uniform bentonite composition in the extruder 16. The auger 18 of the extruder 16 forces the bentonite composition through the die hole 20 of the desired shape, such as the rod shape shown in FIG. 2, to form a rectangular rope. The rope 22 is sent on the conveyor 25, which can be driven at a predetermined speed by the conveyor motor 26.

By varying the speed of the conveyor 24 relative to the speed of the extrusion rope 22 exiting the die hole 20, the rope can be squeezed lightly to change the size of the extruded clay composition.

Conveyor 24 is conveyed onto a conveyor belt 28 for contact with a suitable conveyor belt 28 and the surface of the rope 22 that is extruded through the die hole 20 of the extruder 16. ) Continuous feed. The rope is wound around the take roll 32 as it is extruded onto the release sheet to provide the composition in the form of a perforated rope.

Similarly, as shown in FIG. 5, the extruder 16 may include a die hole 34 elongated to provide a composition of sheet form 22a as shown in FIG. It is cut to length at a suitable cutting station or formed of a sheet coil as shown in FIG. As shown in FIG. 5, the conveyor includes a second continuous feed of release paper 36 to insert bentonite sheets between the upper and lower release sheets.

Second release paper feed 36 is particularly preferred for compositions that do not include elastomers and compositions that have low tack and structural integrity.

3 and 4 show a portion of the rope 22 of FIG. 2 composed of bentonite, polypropene and / or polybutene, and an elastomer before and after hydration.

As a totally unexpected fact, the rectangular three-dimensional block of FIG. 3, when hydrated, is self-remanufactured outward along all surfaces resulting in a central core or block of approximately the size shown in FIG.

That is, it is surrounded by six additional blocks 40 of the same size. The dose of such bentonite compositions containing polypropene and / or polybutene to maintain outward swelling capacity on all surfaces is a new and improved result in the manipulation of water seal compositions, the composition being an elastomeric material. It is particularly useful when it contains.

Elastomeric materials with at least 100% modulus may expand and expand the expanding clay to form enclosed, individually swollen bentonite structures with relatively good structural safety that can resolve any gaps or structural damage that seal the potential leak path. Can be.

Claims (26)

35-90% by weight of water swellable clay; A water-swellable clay composition consisting of 10-65% by weight of polypropene, polybutene or mixtures thereof and free of siliceous fillers. The water-swellable clay composition according to claim 1, wherein the polypropene, polybutene or a mixture thereof is comprised of 15-30% by weight. The water swellable clay composition of claim 1, wherein the water swellable composition consists of 50-80 wt% bentonite. A water swellable clay composition consisting of 35-90 weight percent water swellable clay, 10-65 weight percent polypropene, polybutene or mixtures thereof. The water-swellable clay composition according to claim 4, wherein the polypropene, polybutene or a mixture thereof is comprised of 15-30% by weight. The water-swellable clay composition according to claim 1 comprising 1-20% by weight of elastomer. The method of claim 6, wherein the clay is 50-80% by weight of bentonite; The elastic body is composed of 2-10% by weight; Wherein said polypropene, polybutene or mixtures thereof is comprised of at least 16% by weight. 8. The water swellable clay composition of claim 7, wherein the elastomer has an elastic modulus of at least 500%. 9. The water swellable clay composition of claim 8, wherein the rubber consists of partially crosslinked butyl rubber. 36-90% by weight of water swellable clay; 1-20% by weight of elastomer; A water-swellable composition comprising 2-50% by weight of a plasticizer capable of dispersing the elastic body and free of silicic acid fillers. 11. The process of claim 10, wherein the clay consists of 50-80% by weight of bentonite; The elastic body is composed of 2-10% by weight; The water swellable composition, wherein the plasticizer comprises at least 10% by weight. 35-90% by weight of water swellable clay; A water-expandable product consisting of 10-65% by weight of polypropene, polybutene, or mixtures thereof, suitable for attachment to substrate surfaces for control of leaks extruded to a desired shape. 13. The water-expandable extruded article of claim 12 comprising 1-20% by weight of an elastomer without silicate filler. 35-90% by weight of water swellable clay; 1-20% by weight of elastomer; A water-expandable product formed of 2-50% by weight of a plasticizer capable of stretching the elastic body to form a shape without silicate filler extruded in a predetermined form. Intimate contact of water swellable clay with polypropene, polybutene or mixtures thereof to form a clay composition comprising 35-90 wt% clay, 10-65 wt polypropene, polybutene or mixtures thereof A method for producing a water swellable clay composition, wherein the water swellable clay composition is free. The method of claim 15, wherein the elastomer is uniformly mixed with the intimately contacted bentonite composition to make 35-90% by weight of clay; 10-64% by weight of polypropene, polybutene or mixtures thereof; A method of making a water swellable clay composition comprising providing a clay comprising 1-20% by weight of an elastomer. 17. The method of claim 16 wherein said clay consists of benzoite and said polypropene, polybutene or mixtures thereof is at least 16% by weight. The method of producing a water swellable clay composition according to claim 16, comprising molding the composition into a predetermined shape. 19. The method of claim 18, wherein the composition is molded by extruding through a die hole and comprising conveying the extruded bentonite onto a traveling conveyor having a variable speed that can be adjusted to size the extruded clay composition. Process for preparing swellable clay composition. 17. The method of claim 16, wherein the clay composition is deposited on release paper and the composition is curled on the release paper in a rope form. A water-swellable composition comprising 35-90% by weight of water swellable clay, 1-20% by weight of elastomer having at least 100% elongation, and 2-50% by weight of plasticizer that does not react with the elastomer. 21. The water swellable clay composition according to claim 20, wherein said elastomer is a partially crosslinked butyl rubber and said plasticizer contains 10-30% by weight. The plasticizer of claim 20, wherein the plasticizer is an epoxidized oil; Alkyl monoesters; Long-chain (8-20 carbon) alkyl diesters; aromatic-naphthene oils; Naphthene-aromatic oils; Naphthene-paraffin oil; A water swellable clay composition selected from the group consisting of paraffin flow paths. 35-90% by weight of water swellable clay composition; 1-20% by weight of elastomer; A water swellable composition composed of 2-50% by weight of a plasticizer capable of stretching the elastic body. 25. The water swellable composition of claim 24, wherein said plasticizer consists of polypropene, polybutene or mixtures thereof. 35-90% by weight of water swellable smectite clay; 1-20% by weight of elastomer; A water swellable composition consisting of 2-50% by weight of polypropene, polybutene or mixtures thereof.

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