Method of manufacture of water absorbing laminar material
33 claims: 9 independent, 24 dependent
- 1Sposób wytwarzania absorbującego wodę arkusza materiału znamienny tym, że obejmuje:a) wytwarzanie arkusza materiału inicjującego polimeryzacje poprzez kontaktowanie podłoża będącego sorbentem cieczy lub materiału stosowanego do wytworzenia podłoża będącego sorbentem cieczy z inicjatorem lub katalizatorem polimeryzacji;a następnie b) osadzanie na co najmniej części grubości arkusza materiału inicjującego polimeryzację zawiesiny polimeryzacyjnej zawierającej glinę, polimeryzowalny monomer, oraz wodę w ilości mniejszej niż 50% wagowych zapewniając dokładny kontakt z katalizatorem lub inicjatorem polimeryzacji;i następnie c) poddawanie tego arkusza materiału polimeryzacji in situ z wytworzeniem polimeru osadzonego w arkuszu materiału i unieruchomionego w arkuszu materiału.
- 2Sposób według zastrz. 1, znamienny tym, że zawierająca glinę zawiesina zawiera dodatkowo inicjator polimeryzacji i środek sieciujący polimer.
- 3Sposób według zastrz. 1 albo 2, znamienny tym, że katalizator lub inicjator polimeryzacji wprowadza się do arkusza materiału lub materiału zawartego w arkuszu materiału przed osadzeniem zawiesiny w arkuszu materiału.
- 4Sposób według zastrz. 1, znamienny tym, że zawiesina zawiera środek alkaliczny zobojętniający monomer lub wytwarzany polimer. PL 212 989 B1
- 5Sposób według zastrz. 4, znamienny tym, że alkaliczny środek zobojętniający monomer lub wytwarzany polimer wprowadza się do arkusza materiału w ilości odpowiedniej do zobojętnienia 65-85% molowych polimeru.
- 6Sposób według zastrz. 4 albo 5, znamienny tym, że zawierająca glinę zawiesina zawiera glinę w ilości od 50% wagowych do 80% wagowych w przeliczeniu na masę gliny i zobojętnionego monomeru.
- 7Sposób według zastrz. 1, znamienny tym, że zawiesina jest wolna od katalizatora lub inicjatora polimeryzacji a zawiera środek sieciujący polimer.
- 8Sposób według zastrz. 7, znamienny tym, że zawiesina polimeryzacyjna zawiera nośnik wybrany z grupy składającej się z wody, rozpuszczalnika organicznego.
- 9Sposób według zastrz. 1 albo 7, znamienny tym, że przed osadzeniem monomeru w arkuszu materiału do arkusza materiału lub materiału zawartego w arkuszu materiału wprowadza się oprócz katalizatora lub inicjatora polimeryzacji środek sieciujący i środek zobojętniający monomer.
- 10Sposób według zastrz. 9, znamienny tym, że środek zobojętniający wprowadza się do arkusza materiału w ilości odpowiedniej do zobojętnienia polimeru w 50-100% molowych.
- 11Sposób według zastrz. 9 albo 10, znamienny tym, że środek zobojętniający wprowadza się do arkusza materiału w ilości odpowiedniej do zobojętnienia polimeru w 65-85% molowych.
- 12Sposób według zastrz. 1-11, znamienny tym, że dla spolimeryzowania monomeru w arkuszu materiału i odparowania wody z arkusza materiału j arkusz materiału podczas polimeryzacji i sieciowania polimeru ogrzewa się do temperatury co najmniej 100°C.
- 13Sposób według zastrz. 12, znamienny tym, że dla spolimeryzowania monomeru i usieciowania wytwarzanego polimeru In situ arkusz materiału przepuszcza się przez piec o temperaturze od 100°C do 288°C.
- 14Sposób według zastrz. 13, znamienny tym, że dla spolimeryzowania monomeru i usieciowania wytwarzanego polimeru in situ arkusz materiału przepuszcza się przez piec o temperaturze od 177°C do 288°C.
- 15Sposób według zastrz. 14, znamienny tym, że piec ma temperaturę w zakresie od 204°C do 260°C.
- 16Sposób według zastrz. 14, znamienny tym, że piec ma temperaturę w zakresie od 232°C do 260°C.
- 17Sposób według zastrz. 1-16, znamienny tym, że stosuje się zawiesinę polimeryzacyjną zawierającą glinę w ilości od 5% wagowych do 95% wagowych, w przeliczeniu na całkowitą masę gliny i monomeru.
- 18Sposób według zastrz. 1-17, znamienny tym, że glina obejmuje pęczniejącą w wodzie glinę smektytową.
- 19Sposób według zastrz. 18, znamienny tym, że pęczniejąca w wodzie glina smektytową obejmuje sodową glinę smektytową.
- 20Sposób według zastrz. 19, znamienny tym, że sodowa glina smektytową jest wybrana z grupy składającej się z montmorylonitu sodowego, bentonitu sodowego i ich mieszanin.
- 21Sposób według zastrz. 20, znamienny tym, że sodową glinę smektytową otrzymuje się na drodze wymiany jonowej jonów sodu z jonami wapnia w wapniowej glinie smektytowej.
- 22Sposób według zastrz. 1-21, znamienny tym, że zawiesina polimeryzacyjna zawiera od 20% wagowych do 50% wagowych wody, w przeliczeniu na całkowitą masę zawiesiny polimeryzacyjnej.
- 23Sposób według zastrz. 22, znamienny tym, że zawiesina polimeryzacyjna zawiera od 30% wagowych do 50% wagowych wody, w przeliczeniu na całkowitą masę zawierającej glinę zawiesiny polimeryzacyjnej.
- 24Sposób według zastrz. 23, znamienny tym, że zawiesina polimeryzacyjna zawiera od 35% wagowych do 45% wagowych wody, w przeliczeniu na całkowitą masę zawierającej glinę zawiesiny polimeryzacyjnej.
- 25Sposób według zastrz. 24, znamienny tym, że zawiesina polimeryzacyjna zawiera od 35% wagowych do 40% wagowych wody, w przeliczeniu na całkowitą masę zawierającej glinę zawiesiny polimeryzacyjnej.
- 26Sposób według zastrz. 23, znamienny tym, że zawiesina polimeryzacyjna zawiera od 30% wagowych do 40% wagowych wody, w przeliczeniu na całkowitą masę zawierającej glinę zawiesiny polimeryzacyjnej. PL 212 989 B1
- 27Sposób według zastrz. 1-26, znamienny tym, że glina zawiera pęczniejącą w wodzie glinę smektytową w ilości co najmniej 50% wagowych, w przeliczeniu na całkowitą masę zawiesiny polimeryzacyjnej.
- 28Sposób według zastrz. 1-27, znamienny tym, że glina zawiera 50-100% gliny smektytowej, w przeliczeniu na całkowitą masę gliny w zawiesinie polimeryzacyjnej.
- 29Sposób według zastrz. 1-28, znamienny tym, że stosunek wagowy monomeru do gliny mieści się w zakresie od około 1:19 do około 19:1
- 30Sposób według zastrz. 29, znamienny tym, że stosunek wagowy monomeru do gliny mieści się w zakresie od 1:1 do 1:5.
- 31Sposób według zastrz. 30, znamienny tym, że stosunek wagowy monomeru do gliny mieści się w zakresie od 1:1 do 1:4.
- 32Sposób według zastrz. 31, znamienny tym, że stosunek wagowy monomeru do gliny mieści się w zakresie od 1:2 do 1:4.
- 33Sposób według zaostrz. 1-28, znamienny tym, że polimeryzację w etapie c) prowadzi się poprzez ogrzewanie osadzonego arkusza materiału w temperaturze umożliwiającej spolimeryzowanie monomeru i odparowanie co najmniej części wody z zawiesiny wytwarzając sorbujący wodę polimer związany wraz z gliną w arkuszu materiału.
Independent claims33
92 paragraphs in 3 sections, as filed
The present invention relates to a method for producing a water-absorbent sheet of material, in particular a continuous method for producing a water-absorbing sheet of material.
Published International Application WO 00/72958 A1 ('958) describes a porous substrate, such as a geotextile lining, containing a polymer such as polyacrylamide and / or poly (acrylic acid) that is partially neutralized (e.g. poly (acrylic acid) and polyacrylate. sodium), preferably also clay. This polymer is produced mostly in situ, while the monomer with the clay is embedded in the geotextile to obtain a hydraulic barrier which has extremely low hydraulic conductivity and which, as an active barrier material, is much lighter than the active barrier material in standard geosynthetic linings disclosed in in the description of the invention WO 00/72958. Moreover, as disclosed in WO 00/72958, some synergism may be observed for the combination of a polymerizable monomer such as acrylic acid with clay due to the inclusion of the monomer between the clay lamellae and the incidence of inclusion when mixing the monomer with the clay to form a slurry to suspend it in the clay. geotextile and / or when depositing the slurry in the geotextile.
It has also been found that the production of the article disclosed in WO 00/72958 provides a product with a high water content, which in turn makes it difficult to apply it to a surface protected against water ingress, as well as significantly compromising product shipping and limiting the benefits of its light weight and cost savings. the presence of less active barrier material in the geotextile. Moreover, according to WO 00/72958 A1, the aqueous polymerization solution, the polymerization catalyst and the crosslinker are premixed and deposited in a porous substrate. At the same time, it has been found that during continuous production, only small amounts of polymerizable monomer can be produced as the polymerizable monomer begins to polymerize before being deposited on the porous substrate, deteriorating the fluid barrier properties and reducing the solids retention capacity.
In accordance with the process of the present invention, it has been found that by using a polymerization catalyst or a polymerization initiator directly on a substrate adsorbing a liquid monomer or a substrate absorbing a liquid monomer (hereinafter collectively referred to as "liquid sorbent"), a substrate, preferably a porous geotextile, is produced in the form of a sheet of material for providing a polymerization initiating substrate or sheet of material.
Accordingly, the present invention relates to a method of making a water-absorbent sheet material which comprises:
a) forming a sheet of a polymerization initiating material by contacting the liquid sorbent substrate or the material used to form the liquid sorbent substrate with a polymerization initiator or catalyst; and then
b) depositing a polymerization initiator material containing a polymerization slurry containing clay, polymerizable monomer, and water in an amount of less than 50% by weight over at least a portion of the sheet thickness to ensure intimate contact with the catalyst or polymerization initiator; and next
c) subjecting the sheet of material to in situ polymerization to form a polymer embedded in the sheet of material and fixed to the sheet of material.
Preferably, the clay-containing slurry further comprises a polymerization initiator and a polymer crosslinker.
Equally preferably, the catalyst or polymerization initiator is introduced into the sheet of material or material contained in the material sheet prior to deposition of the slurry in the material sheet.
According to a preferred embodiment of the process according to the invention, the suspension comprises a neutralizing monomer or a polymer to be prepared, an alkaline agent, which is preferably introduced into the material sheet in an amount sufficient to neutralize 65-85 mol% of the polymer. Even more preferably the clay-containing slurry comprises clay in an amount of from 50% by weight to 80% by weight based on the weight of the clay and the neutralized monomer.
In a preferred embodiment of the process according to the invention, the slurry is free of catalyst or polymerization initiator and contains a polymer crosslinker, preferably said polymerization slurry comprises a carrier selected from the group consisting of water and an organic solvent.
In a further advantageous embodiment of the method according to the invention, before the monomer is deposited in the material sheet, it is introduced into the material sheet or the material contained in the material sheet.
In addition to the catalyst or polymerization initiator, the crosslinker and the neutralizing agent of the monomer are preferably in an amount sufficient to neutralize the polymer to 50-100 mol%. Equally preferably, the neutralizing agent is introduced into the material sheet in an amount sufficient to neutralize the polymer to 65-85 mole percent.
In a preferred embodiment of the process according to the invention, to polymerize the monomer in the material sheet and to evaporate the water from the material sheet, the material sheet is heated to a temperature of at least 100 ° C during polymerization and cross-linking of the polymer. Preferably, to polymerize the monomer and cross-link the produced polymer in situ, the sheet of material is passed through an oven at a temperature of 100 ° C to 288 ° C, more preferably 177 ° C to 288 ° C even more preferably 204 ° C to 260 ° C or 232 ° C. C to 260 ° C.
According to a preferred embodiment of the invention, a polymerization suspension containing clay in an amount of from 5% by weight to 95% by weight, based on the total weight of clay and monomer, is used.
Preferably the clay comprises water-swellable smectite clay, more preferably sodium smectite clay, with even more preferably sodium smectite clay selected from the group consisting of sodium montmorillonite, sodium bentonite and mixtures thereof, where preferably sodium smectite clay is obtained by ion exchange with sodium ions with calcium ions in calcium smectite clay.
In a preferred embodiment of the process according to the invention, the polymerization suspension comprises from 20% by weight to 50% by weight of water, based on the total weight of the polymerization suspension, more preferably from 30% by weight to 50% by weight of water, based on the total weight of the clay-containing polymerization suspension, even more preferably. from 35% by weight to 45% by weight of water, based on the total weight of the clay-containing polymerization suspension, even more preferably from 35 wt% to 40 wt% water, based on the total weight of the clay-containing polymerization suspension, and most preferably from 30 wt% to 40 wt% water, based on the total weight of the clay-containing polymerization suspension.
According to a preferred embodiment of the process of the invention, the clay comprises the water-swellable smectite clay in an amount of at least 50% by weight, based on the total weight of the polymerization suspension.
It is also preferred that the clay comprises 50-100% smectite clay, based on the total weight of the clay in the polymerization suspension.
Preferably, the weight ratio of monomer to clay is in the range of about 1:19 to about 19: 1, more preferably in the range of 1: 1 to 1: 5, even more preferably in the range of 1: 1 to 1: 4 and most preferably in the range of 1: 2 to 1: 4.
Preferably, in the process of the invention, the polymerization in step c) is carried out by heating the deposited sheet of material at a temperature that allows the monomer to polymerize and evaporating at least a portion of the water in the slurry to produce a water-absorbing polymer bound with the clay in the sheet of material.
The present inventors have found that complete polymerization of the monomer in contact with the polymerization initiating substrate gives the best results in terms of retaining embedded and interwoven polymer solids.
By using the method disclosed herein, the aqueous polymerization solution containing the polymerizable monomer but not containing the polymerization catalyst or polymerization initiator can be mixed in large amounts that will not polymerize prematurely before being deposited on the sorbent liquid substrate. In addition, the use of a substrate retaining and containing a monomer, polymerization catalyst or polymerization initiator allows the efficient polymerization solution to be applied to the substrate with a minimum amount of a carrier such as water and / or an organic solvent. wherein the monomer-containing polymerization solution is readily deposited on the substrate containing the catalyst and / or polymerization initiator, thereby reducing drying time and cost of the solvent itself.
By the method for producing a water-absorbent sheet of material according to the invention, a hydraulic barrier can be obtained from a sheet of material containing a liquid polymer sorbent and a liquid clay absorbent. The polymer and clay are structurally reinforced with a sheet of material, in particular with a fibrous sheet of material such as a woven or non-woven geotextile containing a liquid polymer sorbent and a liquid clay absorbent, in a polymer / clay weight ratio ranging from 1:19 to 19 : 1, preferably from 1: 1 to 1: 5, more preferably from 1: 1 to 1: 4,
Most preferably from 1: 2 to 1: 4. The polymerization catalyst or polymerization initiator is first introduced into the geotextile or into the fibers used to manufacture the geotextile, and then the high-viscosity suspension containing one or more polymerizable monomers and the liquid clay absorbent are introduced into the substrate initiating the polymerization of the liquid sorbent, while the polymerization of the monomer does not will begin before contacting the monomer with the polymerization initiating medium, wherein the monomer is substantially completely in situ polymerized to fix the position of the polymer and clay in the layer material. In a preferred embodiment of the present invention, the polymer is sufficiently cross-linked, i.e. with regard to water insolubility and water absorption rate. Sufficient cross-linking is achieved by the use of at least about 0.1% by weight, and more preferably at least 0.1% by weight, of cross-linking agent, based on the amount of the polymerizable monomer. The monomer crosslinker may be included, based on the monomer content, in an amount ranging from about 1: 100 to about 1: 1000; more particularly in the range of from about 1: 250 to 1: 750; especially in the range of from about 1: 400 to about 1: 600.
The liquid sorbent base is deposited in about 20 wt% to about 50 wt% monomer and about 50 wt% to about 80 wt% clay based on the total amount of monomer and clay in the monomer / clay slurry. Such polymerization solution has a weight ratio of clay to water ranging from about 2: 8 to about 8: 2, more preferably from 3: 2 to 2: 3, most preferably about 1: 1. The monomer is polymerized by evaporating while the water is evaporated to form a substrate containing less than about 15% by weight of water, more preferably less than about 12% by weight of water.
The above and other advantages, uses and advantages of the inventive method as well as the disclosed articles obtained using the inventive method will become clear and understandable from the following detailed description of the invention and the accompanying drawings.
The figure is a schematic diagram of a preferred method of making a sheet of polymer-containing material.
The present invention will be better understood by reference to the following detailed description of the invention and the examples provided therein. It is understood that the present invention is not limited to those particular embodiments and the indicated ingredients, products, methods and / or conditions which may be modified without departing from the spirit of the present invention. It is also understood that the terms used herein describe only particular embodiments of the invention and should not be used to limit its scope in any way.
Ranges indicated herein as "about" or "approximately" refer to one particular value, and / or "up to about" or "approximately" refer to another particular value. Likewise, when values are approximated, by the use of the preceding "about" the value is assumed to constitute another embodiment of the invention.
With reference to the drawing, the invention relates to the material of the hydraulic partition 10. In one embodiment of the present invention, the hydraulic barrier material is a braided matrix comprising a water-absorbent organic polymer and a water-absorbent clay bonded to a substrate and a liquid monomer-absorbing substrate or to a liquid monomer-adsorbing substrate in which the polymer is formed in situ (it is the polymerization product of one or several monomers), during the manufacture of the hydraulic barrier, it is in contact with the substrate to be woven into the substrate by polymer and clay. In a preferred embodiment of the present invention, the hydraulic barrier material 10 is an interwoven matrix of organic polymer particles, embedded polymer clay, polymer embedded clay tacttoids, chipped clay lamellae and fibrous substrate fibers 12, preferably with fibrous substrate fibers 12, preferably non-woven geotextile. The preferred inorganic polymer is a water-absorbing polymer preferably containing a mixture of alkali metal salts of poly (acrylic acid) (50-90 mol% - corresponding to 50-90 mol% of acrylic acid neutralization) and poly (acrylic acid) (10-50 mol%). It has been found that the interweaving of the organic polymer, clay ttoids into the intervening polymer, and clay platelets into the substrate 12 provides a hydraulic barrier material 10 with relatively low water permeability while at the same time containing a relatively low amount of organic polymer.
Moreover, it has been found that the hydraulic partition material 10 reduces the water permeability per unit weight of the hydraulic partition material as compared to conventional linings or plumbing baffles, in particular geosynthetic clay (GCL) liners (GCL for "geosynthetic clay lines"). In particular, the material 10 of the hydraulic partition has been found to have a hydraulic conductivity of 1 × 10<sup>-9</sup> cm / s or less. Moreover, the material of the hydraulic partition was found to be
PL 212 989 B1 is thinner and lighter in weight, and has better water impermeability compared to conventional ones
GCL. The hydraulic partition material 10 may be particularly suitable for geo-environmental applications such as water absorption, containment and isolation. For example, the hydraulic partition material may be used in underground garages, shopping promenades, and the like to prevent water ingress; for leveling the site with garbage; in artificial water reservoirs; and for those geoenvironmental applications where a low permeability hydraulic partition is used. In a preferred embodiment of the present invention, the organic polymer is produced during the polymerization of an organic monomer embedded in clay, preferably a water-swellable clay. The method of producing the hydraulic barrier material comprises the steps of depositing a polymerizable organic monomer in a liquid sorbent substrate, wherein the polymerization catalyst or polymerization initiator is first introduced into the liquid sorbent substrate or into one or more components of the liquid sorbent substrate, e.g., geotextile fibers during geotextile fabrication. and the in situ polymerization of the polymerizable monomer was performed to form the hydraulic barrier material.
The polymerizable monomer is applied to a polymerization initiating substrate from a polymerization solution which is a suspension of a polymerizable organic monomer and a water swellable clay such as sodium smectite clay, in particular sodium montmorillonite or sodium bentonite clay, to form a slurry 14 which is embedded in a porous substrate 12 that have previously been treated, for example contacted, dipped or sprayed to obtain sufficient organic monomer polymerization catalyst or polymerization initiator to completely polymerize the monomer thereafter deposited. In a preferred embodiment of the present invention, at least 5% by weight of the polymerization initiator or polymerization catalyst, based on the total amount of polymerizable monomer then embedded in the substrate, the polymerization solution (polymerization suspension), is applied to the substrate 12. More preferably, at least 10% by weight of the polymerization initiator and / or polymerization catalyst, based on the total amount of polymerizable monomer subsequently deposited, is applied to the substrate 12.
The polymerizable monomer 6 is preferably mixed with water 2 and contains a neutralizing agent 8 such as sodium hydroxide, preferably prior to the addition of the clay 9, to form a slurry polymerization solution 14 to facilitate neutralization of at least part of the polymerizable organic monomer (most preferably neutralizing 65). -85 mole%) before introducing the clay and the subsequent addition to the clay of the partially neutralized polymerizable organic monomer. Preferably, the polymerization solution also comprises a crosslinker 11 for the polymer, after polymerization the partially neutralized monomer molecules are sufficiently crosslinked to obtain water insolubility and water absorbance. Preferably, the polymerizable monomer, water, crosslinker and neutralizing agent are mixed together to form a homogeneous solution prior to introducing the clay to form a polymerization solution or suspension to obtain the desired consistency and homogeneity of the inclusion into the clay. In a preferred embodiment of the present invention, the step of mixing the solution is performed so as to obtain a substantially homogeneous polymer solution.
The step of introducing the clay into the monomer solution to form the polymerization solution or polymerization slurry 14 may be performed by any method that will introduce the desired amount of clay and monomer to form a relatively viscous slurry 14, which, however, may be sent to the polymerization initiating substrate 12 for deposition. In addition, the clay-containing polymerization solution is preferably sheared during mixing and / or is sheared when depositing the slurry in a liquid sorbent substrate or porous substrate to insert a portion of the polymerizable monomer between the clay plates prior to embedding the slurry 14 in the substrate 12, and preferably to partially exfoliate the plaques. clays before or simultaneously with contacting substrate 12 with the polymerization solution.
The degree of mixing of the slurry 14 will vary depending on the desired properties of the slurry 14. For example, the clay may simply be mixed with the polymerization solution, regardless of the degree of mixing or the homogeneity of the resulting slurry 14. The mixing step is preferably performed so that the slurry 14 is mixed before the next settling. slurries 14 in substrate 12 containing a catalyst or initiator. In a preferred embodiment of the present invention, the mixing step in preparing the slurry is performed so that the slurry 14 is substantially homogeneous.
PL 212 989 B1
Any mixer 16 and mixing method that can mix the clay and monomer to achieve the desired properties of the slurry 14 can be used. Thus, in a preferred embodiment of the present invention, any mixer 16 and mixing method that can mix the clay with the polymerization solution to obtain a slurry can be used. 14, which is substantially homogeneous. Preferably a minimum amount of water is used, sufficient to obtain a homogeneous suspension that can be mechanically transferred or pumped into the substrate 12 for the purpose of deposit the slurry in the substrate. As shown in Fig. 1, a preferred embodiment of the invention employs a piston 32 from the piston assembly 30 to transfer the viscous slurry to the liquid sorbent substrate for the settling step. If the slurry is too viscous for pumping, a conveyor belt is used to transfer the slurry to the substrate 12 for deposition, preferably having a covered width equal to that of the substrate 12, and may be used to transfer the slurry to the substrate 12.
As noted above, the step of depositing the monomer comprises mixing a slurry of polymerizable organic monomer and clay with the substrate 12.
In one embodiment of the present invention, slurry 14 is embedded in a catalyst-containing liquid sorbent substrate 12 at a slurry viscosity of from about 30 to 80 kg m / s ((30,000 cps) to about (80,000 cps)), particularly from about 40 to about 60 kg m / s ((40,000 cP) to about (60,000 cP)) for the absorption and / or adsorption of the slurry 14 into and / or between the components of the substrate 12. The slurry 14 penetrates at least a portion of the thickness of the substrate 12. Any amount or degree of embedding of the slurry 14 in or between portions of the substrate 12 is acceptable as long as the deposition of the monomer allows the monomer and clay to be mixed and sorbed between the components and / or in part of the components, e.g. to produce the hydraulic barrier material. Further, the degree and amount of deposition is sufficient if it allows the obtained absorbent polymer and clay to be bonded or woven over at least part of the thickness of the substrate 12.
Preferably, the deposition step comprises the step of combining the substrate 12 with the slurry 14 so that the slurry 14 is evenly distributed over at least parts of the thickness of the substrate 12. The slurry 14 is preferably mixed thoroughly, and more preferably is substantially homogeneous whereby joining the slurry 14 to the substrate 12 also causes separation monomer, clay entwined with monomer and exfoliated clay plates over the entire desired thickness with the substrate 12. More preferably, the slurry is distributed over the entire thickness of the porous substrate 12 to facilitate the production of relatively uniform hydraulic barrier material 10.
As discussed previously, porous substrate 12 may be any porous liquid-absorbent or liquid-adsorbent material, or a substance miscible with the monomer and any other ingredients contained in the polymerization suspension 14, if any. Any liquid sorbent substrate can be used that can receive and retain at least a portion of both the polymerization catalyst and polymerization initiator, and then the polymerizable monomer / monomers and clay to form the hydraulic barrier material after polymerization of the monomer. More preferably, substrate 12 comprises a fibrous substrate 12 having a plurality of fibers. Any fibrous substrate 12 that can form the hydraulic barrier material 10 upon polymerization of the monomer can be used.
In another embodiment of the present invention, the substrate 12 is a geotextile material. Any woven or non-woven geotextile material may be used, preferably a non-woven material. In addition, the geotextile material may be in any form compatible with the manufacture of the desired plumbing barrier material 10. However, in a preferred embodiment, the fibrous substrate 12 is a substantially flat plate comprising at least one layer of geotextile materials.
In another embodiment of the present invention, the settling step comprises depositing a slurry 14, having a water content of less than 50% by weight, as well as monomer and clay, between the fibers of the substrate 12 containing the initiator or catalyst. The deposition step may be performed by any means and with any apparatus, yielding, after deposition, a highly viscous slurry 14 absorbed between and / or in portions of the component, for example in the fibers of the substrate 12. In other words, the slurry 14 may be embedded in or directed to the interstitial spaces or interstitial voids or voids with fibers between and / or absorbed by the fibers of the fibrous substrate 12, and / or may be absorbed by the fibers of the substrate 12. The slurry 14 may, for example, be deposited. between the fibers of the fibrous substrate 12 by means of vacuum, rinsing, rolling, hydraulic loading, pressure filtration or spraying. If the fibers themselves absorb water, the monomer will also be absorbed into the fibers.
PL 212 989 B1
In yet another embodiment of the present invention, at least a portion of the slurry 14 is deposited between the fibers of the interstitial space or between the voids. Any remaining slurry 14 that has not been deposited may be dispersed or distributed between the fibers of the fibrous substrate 12, or distributed over the fibers or around the fibers to form a layer or coating of the slurry 14. Any sufficient amount or degree of embedding of the slurry 14 between the fibers of the substrate 12 is acceptable to allow subsequent polymerization of the monomer.
In accordance with a further embodiment of the present invention, the major part of the slurry 14 is embedded in the substrate 12, while a minor portion of the slurry 14 may optionally be dispersed or distributed over the surface of the substrate 12. Preferably, any slurry 14 that can be broken on the surface of substrate 12 has a thickness less than about 2.0 mm, more preferably less than about 1.0 mm, most preferably less than about 0.50.
Moreover, in another embodiment of the present invention, the slurry 14 is deposited between the fibers of the substrate 12 by applying a compressive force to the fibrous substrate 12. The compressive force is preferably applied in a direction substantially perpendicular to the plane of the fibrous substrate 12, as discussed below. The compressive force may be applied by any means and by any method or device that achieves a favorable degree or amount of deposited slurry 14 between the fibers of the fibrous substrate 12.
For example, a compressive force may be applied to the fibrous substrate 12 using a pair of pressing rollers 18 as shown in Fig. 1. Further, a compressive force may be applied to the fibrous substrate 12 by using a vacuum.
After the deposition step, the method comprises a step of polymerizing the monomer to produce the hydraulic barrier material 10. The polymerization of the monomer may be performed by any method suitable for polymerizing the monomer to produce the hydraulic barrier material 10 with the desired properties and characteristics. Preferably, the polymerization of the monomer is performed by heating the monomer in a continuous oven after the settling step. Preferably, the heating step is sufficient to dry the plumbing barrier to a moisture content of less than about 15% by weight, more preferably about 7-12% by weight, based on the dry weight of the plumbing barrier 10.
The heating step may be performed at any temperature above the boiling point of water to polymerize the monomer and form the hydraulic barrier material 10. The temperature of the heating stage may vary depending on the desired characteristics and properties of the obtained hydraulic barrier material 10. It has been found that slurry 14 is preferably heated to a temperature of at least 100 ° C (212 ° F), more preferably from about 140 ° C to about 288 ° C, most preferably from about 177 ° C to about 288 ° C. and particularly preferably from about 204 ° C to about 260 ° C. In the most preferred embodiment of the present invention, the slurry was heated to about 232 ° C to about 260 ° C.
Any heater suitable for heating the slurry 14, and hence the monomer, to the desired temperature may be used in order to polymerize the monomer deposited in the substrate 12 without melting or otherwise degrading the substrate 12. In addition, the heating step may be performed for any time sufficient to produce the hydraulic partition material 10 with the advantageous properties of the hydraulic partition. For example, the heating step may be performed for about 30 seconds to about 2 hours. The amount of monomer polymerized during heating may vary depending on the time and temperature of the heating step, which affects the properties and characteristics of the resultant hydraulic barrier material 10. Moreover, it was found that the polymerization reaction time or duration of the heating step is inversely proportional to the polymerization temperature.
According to an important advantage of the preferred embodiment of the production process disclosed in the present invention, no substantial polymerization of the monomer takes place prior to the deposition of the polymerization slurry on the substrate 12, with the major part of the polymerization taking place during said polymerization step or heating step, the polymerization catalyst or polymerization initiator being recovered from monomer after embedding the monomer in the substrate 12. Thus, in a preferred embodiment of the present invention, there is no substantial polymerization of the monomer prior to depositing the slurry 14 with the fibers of the fibrous substrate 12 containing the initiator or catalyst. Thus, the monomer does not polymerize in the monomer embedded in the substrate containing the initiator or catalyst prior to the heating step. The inhibition of the polymerization of the monomer prior to the settling step is an important advantage of the disclosed production method. Depending on the application
In particular, the cover layer 24 preferably extends along at least one side of the substrate 12, which is a geotextile in the preferred geotextile material 10. variety.
In a preferred embodiment of the present invention, substrate 12 may be any water-absorbing or water-adsorbing sheet material. Moreover, the substrate 12 is preferably a fibrous substrate having a plurality of fibers. More preferably, the fibrous substrate 12 is a geotextile. Any geotextile, both woven and non-woven, of any weight and made of any polymerization temperature resistant material, which is compatible with the intended use of the plumbing barrier material, and which provides the plumbing barrier material 10 with the desired water barrier properties, can be used. However, it is preferred that the geotextile has a basis weight of from about 0.05 to about 0.80 kg / m2<sup>2</sup>, more preferably from 0.10 to 0.40 kg / m2<sup>2</sup>, most preferably from 0.10 to 0.20 kg / m2<sup>2</sup>.
In addition, the geotextile may be of any shape suitable to provide the desired hydraulic barrier material of any size or shape to be protected from substantial contact with water. In a preferred embodiment of the invention, the fibrous substrate 12 is a substantially planar layer comprising at least one layer of geotextile. Thus, as discussed above, the preferred monomer depositing step applies a compressive force in a direction substantially perpendicular to the plane of the geotextile 12. In a preferred embodiment of the present invention, the fibrous substrate 12 comprises a geotextile layer such as PETROMAT 4597, PETROMAT 4551 or PETROMAT 4506 manufactured by Amoco or more preferably GEO-4-REEMAY 60 polyester manufactured by Foss, Inc., 2 mm thick; or other 25WN040-60 polyester, manufactured by CUMULUS Corporation, 5mm thick.
In a preferred embodiment of the present invention, the aqueous polymerization solution comprises water and an amount of a polymerizable organic monomer. Any organic monomer which, when polymerized, produces a water-absorbent organic polymer can be used. However, preferably the organic monomer has the following structural formula:
H2C = CH-COR where R is selected from the group consisting of alkali metal, H, CH3, CH2CH3, CH (CH3) 2; and mixtures thereof.
In a preferred embodiment of the present invention, the monomer is selected from the group consisting of acrylic acid, alkali metal acrylate, for example sodium acrylate, and in particular mixtures thereof containing 50-90 mole% alkali metal acrylate and 10-50 mole% acrylic acid, more preferably about 65-85 mole%. The mole% alkali metal acrylate and 25-35 mole% acrylic acid, based on the total number of moles polymerizable acrylic acid monomer.
It has been found that the weight ratio of the organic monomer (or polymer) to clay embedded in the substrate is sufficient to very efficiently produce the desired plumbing barrier material 10, with almost no drying required after polymerization of the monomer, it should be in the range of 1: 1 to 1: 5. preferably from 1: 1 to 1: 4, most preferably from 1: 2 to 1: 4, based on the total weight of the monomer, neutralized monomer and clay slurry.
The disclosed invention is suitable for producing any sorbent substrate, in particular a sheet of material, with a monomer suspension in clay, wherein the polymer is polymerized in situ after pre-introducing a sufficient amount of polymerization catalyst and / or polymerization initiator into the porous substrate to completely polymerize the polymerizable monomer or monomers. in contact with the substrate 12, without prematurely polymerizing the monomer.
The polymerization solution preferably also contains a monomer crosslinker. Any cross-linker which is compatible with the organic monomer and suitable for cross-linking the organic monomer can be used. The crosslinker is preferably selected from the group consisting of phenol-formaldehyde resin, terephthalaldehyde and N, N'-methylenebisacrylamide (MBA) and mixtures thereof. In a preferred embodiment of the invention, the cross-linker is N, N'-methylenebisacrylamide.
Any amount of crosslinker, or any ratio of crosslinker to monomer sufficient to sufficiently crosslink the monomer, can be used. However, as noted above, the actual amount or ratio of the cross-linking compound will vary depending, among other things, on the desired characteristics or properties of the hydraulic barrier material 10, including its water-absorbing capacity (WAC) (WAC for "water-absorbing capa city"). For example, it has been found that water solubility is increased as the ratio of crosslinker to monomer increases
The obtained absorbent polymer decreases. However, in addition, when the ratio of crosslinker to monomer is increased, the obtained water absorption capacity also increases. In addition, however, as the ratio of cross-linker to monomer is increased, the WAC value of the obtained absorbent polymer is decreased. Thus, a desired balance must be achieved between the WAC and the water solubility of the absorbent polymer comprising the hydraulic barrier material. In one embodiment of the present invention, the weight ratio of the suspension agent 14 is in the range of less than 1: 100, preferably in the range of about 1: 1000 to about 1: 100, more preferably in the range of about 1: 750 to 1: 250, most preferably in the range of about 1: 1000 to about 1: 250. range from 1: 600 to 1: 400.
Furthermore, the polymerization solution or suspension is preferably an acidic solution. In particular, the polymerization solution preferably has a pH below 7. The pH of the polymerization solution can be adjusted in any way with any substance or compound that can give an acidic solution and that is miscible with the components of the polymerization solution. However, the polymerization solution preferably further comprises a sufficient amount of an alkali to neutralize preferably 50-100 mole%, more preferably 50-90 mole% of a monomer, for example acrylic acid, which forms the neutralized polyacrylate, in situ, most preferably 65-85 mole%.
Any alkaline compound that is capable of at least partially neutralizing the monomer or the produced polymer can be used. Preferably, the alkaline compound is selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide, and mixtures thereof. Preferably, the alkaline compound is sodium hydroxide.
As stated previously, an amount of the water-swellable clay may be introduced into the polymerization solution to form a slurry 14. Any clay may be incorporated, upon hydration, into the polymerizable solution and mixed with the polymerization solution to form a slurry 14, as above. Preferred water-swellable clays are smectite clays selected from the group consisting of montmorillonite, saponite, nontronite, laponite, beidelite, iron saponite, hectorite, sauconite, stevensite and mixtures thereof. The preferred clays are smectite clays, preferably sodium smectite clay, especially montmorillonite and sodium bentonite. Other water-resistant clays or fillers may be incorporated into the polymerization solution, such as calcium carbonate, talc, mica, vermiculite, kaolin, titanium dioxide, silicon dioxide, and the like, the polymerization solution (in this clay variant) containing at least about 5% of the water-swellable clay, preferably at least about 20% by weight of the water-swellable clay. The particular weight ratio or relative amounts of the organic monomer may preferably be selected in the range of from about 20% by weight to about 50% by weight of the monomer (including neutralizing agent) and from about 50% by weight to 80% by weight of clay based on the total weight of the monomer, neutralized. monomer and clay in the polymerization suspension.
The polymerization slurry 14 should contain less than about 50 wt.% Water, preferably less than about 40 wt.% Water, based on the total weight of the slurry 14. Preferably, the slurry 14 contains from about 30 wt.% To about 50 wt.% Water by weight of the total slurry. 14. In a preferred embodiment, the slurry 14 from about 35 wt.% To about 45 wt.% Water, based on the total weight of the slurry 14, to allow pumping through the piston 32. A slurry containing only about 20% by weight of water can be transferred to the substrate 12 for embedding in the substrate using a transporter (not shown) while providing sufficient water to uniformly distribute the monomer throughout the mass of clay and substrate 12.
Based on the drawing, a device and a continuous method of producing the hydraulic partition material were developed.
First, a geotextile layer containing a fibrous substrate 12 was introduced through a bath containing a polymerization catalyst or polymerization initiator 20 and then passed through a pair of wring rolls 22 to remove excess catalyst and / or initiator.
Alternatively, the polymerization catalyst and / or the polymerization initiator can be sprayed onto the substrate 12 by means of spray nozzles 31. In a preferred embodiment of the present invention, the substrate is impregnated with the polymerization catalyst and / or the polymerization initiator, then a vacuum is applied to the lower surface 33 of the saturated substrate 12 by means of a vacuum device 35 in contact with the lower surface 33 of the saturated substrate 12 to remove excess polymerization catalyst. and / or a polymerization initiator or their recycling. The fibrous substrate 12 containing the catalyst and initiator, after removal of excess catalyst and / or initiator, was then fed under a guide roller 24 and between a pair of horizontally arranged embedding rollers 18, where
The slurry 14 was pressed (compressed) into the region of the trough 39 for the substrate 12 containing the polymerization catalyst and / or the polymerization initiator.
The slurry 14 is mixed in a slurry container 26 in which the components of the slurry 14 are mixed with a mixer 16. After mixing and preferably after shearing in a slurry container 26 in which the polymerization solution comprises water-swellable clay, the mixer is lifted from the container 26 and slides along the tracks 28 so that the container 26 is immediately below the piston pump assembly 30 which includes a vertically sliding high pressure piston 32. The piston 32 then moves downward in the container 26 to convey the high viscosity and low water slurry 14 through a 20.32 cm (8 inch) diameter flexible conduit 29 to introduce the slurry into the region of the trough 39 for receiving a shaped slurry. V between the extrusion rollers 18. The viscous slurry 14 is difficult to convey through the narrow conduit, and therefore a conduit with a diameter of at least about 10.16 cm (4 inches) is used. Between the squeezing rollers, the slurry 14 is applied to a layer of fibrous substrate 12 of the geotextile containing the polymerization initiating catalyst and / or initiator, the substrate 12 passing between the squeezing rolls 18. Squeezing rollers 18 force the slurry 14 into the substrate 12 at a pressure sufficient to deposit the slurry 14 on it. the entire thickness of the substrate 12. As shown in Fig. 1, the geotextile 12 containing the polymerization catalyst and / or the polymerization initiator is in contact with the depositing rollers 18, the compression force forcing the deposited suspension 14 between the fibers of the fibrous substrate 12.
The compressed geotextile with the slurry 14 deposited thereon then passes through a heater or furnace 34 to polymerize the monomer and weave the resulting polymer and clay into the substrate 12. The polymerization entwines the produced polymer and clay with the geotextile fibers. The result is a hydraulic barrier material. If preferred, the hydraulic partition material 10 can be additionally dried, then rolled up and packaged.
The material of the hydraulic partition expands on contact with water. It has been found that upon contact with water, the unfilled voids or interstitial spaces of the fibrous substrate 12 are first filled with the hydrated polymer gel. Further hydration of the polymer gel causes the entire hydraulic barrier material to expand. Subsequently, it was found that under the standard effective tensile load of 20 kPa, the hydraulic conductivity of the described hydraulic barrier material is less than or equal to approximately 1 x 10<sup>-9</sup> cm / s. In addition, it has generally been found that the hydraulic conductivity decreases with increasing standard effective load.
Examples
The polymerization slurry containing 354 lb. (11.91%) acrylic acid was stirred; 37.65 wt.% (1119 pounds) sodium montmorillonite clay; (314 lb. 50% NaOH solution), 15.28 wt.% Active NaOH; 45.12 by weight (1184 lb) of water together with water introduced with NaOH and 0.03% by weight (0.072 lb) of methylene bisacrylamide (MBA) crosslinker. The introduced NaOH is sufficient to neutralize 80 mol% of acrylic acid.
The suspension was embedded in the polyester fabric GE0-4-REEMAY 60 by Foss Inc., with a thickness of 2 mm and a basis weight of 1.66 kg / m<sup>2</sup> (0.34 lb / ft<sup>2</sup>), which for standard effective tensile load was pre-dipped in a polymerization initiator (sodium persulfate solution containing 16-30% active sodium persulfate) to fully saturate the sheet material such that the fabric, after <sub>2</sub> After removing excess initiator under vacuum, 2.8 g sodium persulfate initiator per 0.093 m<sup>2</sup> (per square foot) of the fabric before depositing the slurry thereon. In a preferred embodiment of the present invention, 4 to 14 g of an aqueous solution of sodium persulfate at a concentration of 28% are applied to the fabric.<sub>2</sub> by weight of active substance per 0.093 m<sup>2</sup> (per square foot) of fabric up to a total of 2.8 g <sub>2</sub> sodium persulfate per 0.093 m<sup>2</sup> (per square foot) and then the polymerization initiator fabric <sub>2</sub> it is deposited with acrylic acid taken in an amount of 28 g per 0.093 m<sup>2</sup> (per square foot). A preferred wet-applied amount of the polymerization solution is 232 g of slurry per<sub>2</sub>
0.093 m<sup>2</sup> (per square foot) of the fabric. Five different samples were prepared, each containing different amounts of slurry, and each polymerized in situ at different oven temperatures. The data presented in Table 1 show that at temperatures lower than 191 ° C to 232 ° C, better results were obtained in the impermeability test both in demineralized water (DI Perm) as well as in water containing 3.5% salt (3.5% Salt Perm).
PL 212 989 B1
Table 1
<td>a sample</td><td>Oven temperature, ° C</td><td>Quantity kg / m<sup>2 </sup>(lb / ft<sup>2</sup>).</td><td>free swelling (wet weight / dry weight)</td><td>Permeability DI cm / s</td><td>Salt permeability 3.5% cm / s</td>
<td> 1</td><td> 191</td><td> 1,3505 (0,2766)</td><td> 13,307</td><td>7.80x10<sup>10</sup></td><td>1.70x10<sup>10</sup></td>
<td> 2</td><td> 204</td><td> 1,447 (0,2959)</td><td> 12,004</td><td>9.06x10<sup>10</sup></td><td>2.40x10<sup>10</sup></td>
<td> 3</td><td> 218</td><td> 1,3783 (0,2823)</td><td> 13,510</td><td>1.20x10<sup>10</sup></td><td>2.9x10<sup>10</sup></td>
<td> 4</td><td> 232</td><td> 1,2147 (0,2488)</td><td> 14,362</td><td>8.40x10<sup>10</sup></td><td>2.6x10<sup>10</sup></td>
<td> 5</td><td> 246</td><td> 1,4047 (0,2877)</td><td> 14,318</td><td>8.30x10<sup>10</sup></td><td>6.00x10<sup>10</sup></td>
Table 2
Comparative trial according to the prior art ST Bentomat Hydraulic Barrier
<td>The amount of clay</td><td>DI transmittance</td><td>Salt water permeability, cm / s</td>
<td>4.15 kg / m<sup>2</sup> (0.85 lb / ft<sup>2</sup>)</td><td>2.60x10<sup>9</sup>cm / s</td><td>5.0x10<sup>6</sup> cm / s</td>
Comparison of the permeability obtained for hydraulic barriers according to the invention (Table 1) with a typical barrier according to the prior art ST Bentonite Hydraulic Barrier (Table 2) shows the surprisingly low water permeability of the hydraulic barriers manufactured according to the present invention, in particular for salt contaminated water. Prior art hydraulic break compositions with three times the clay content allow about 3000 times the amount of salt contaminated water to pass through compared to the loading of the compositions in the present invention. For demineralized water, the prior art hydraulic barrier composition contains three times the amount of clay compared to the amount of clay in the compositions described in the inventive process allows 3 times more demineralized water to pass through the composition than the hydraulic barrier compositions disclosed herein.
Contents3
1 sheet
Sheet 1
13 members in 7 offices
Priority claims3
| Document | Office | Kind | Date |
|---|---|---|---|
| 25473402 | United States of America | A | |
| 10254734 | – | – | – |
| US20020254734 | – | – | – |
Members13
| Document | Office | Kind | |
|---|---|---|---|
| NO20034258D0 | Norway | D0 | |
| US2004058077A1 | United States of America | A1 | |
| NO20034258L | Norway | L | |
| EP1402945A2 | European Patent Office (EPO) | A2 | |
| KR20040027374A | Republic of Korea | A | |
| PL362420A1 | Poland | A1 | |
| AU2003236447A1 | Australia | A1 | |
| CN1497018A | China | A | |
| US6783802B2 | United States of America | B2 | |
| EP1402945A3 | European Patent Office (EPO) | A3 | |
| AU2003236447B2 | Australia | B2 | |
| NO332662B1 | Norway | B1 | |
| PL212989B1This record | Poland | B1 |
Numbers
- Publication
- 212989
- Publication, DOCDB
- 212989
- Publication, EPODOC
- PL212989B
- Application
- 362420
- Application, DOCDB
- 36242003
- Application, EPODOC
- PL20030362420
Titles2
- English
- Method of manufacture of water absorbing laminar material
- Polish
- Sposób wytwarzania absorbujacego wode arkusza materialu
Classification
- CPC, 6
- C08J5/00
- B01J20/261
- B01J20/267
- B01J20/28026
- B01J20/3206
- Y02P20/582
- IPC, 10
- B01J20 32
- C08J5 18
- B01J20 12
- B01J20 26
- B01J20 28
- B01J20 30
- B32B27 04
- C08J5 00
- D06M14 00
- E02D19 18
