MXPA01006784A - Poly(ethylene oxide) and organically modified clay compositions having reduced melt viscosity and improved stability to aqueous fluids and a one-step process for making the same - Google Patents

Abstract

The present invention discloses water-responsive with improved stability to aqueous fluids comprising water or water vapor, processes for enhancing the stability of water-responsive compositions and processes for making such compositions. The compositions of the present invention comprise a water-responsive polymer and organically modifiedclay particles. In one embodiment, the water-responsive polymer is a polymer of ethylene oxide, specifically poly(ethylene oxide) and specific graft copolymers of poly(ethylene oxide). Films of the present invention are water-responsive and breathable and are especially useful for personal care applications including disposable diapers, feminine pads, pantiliners and training pants. Advantageously, compositions of the present invention have reduced melt viscosity and are more easily melt processed into films, fibers and other articles.

Description

COMPOSITIONS OF ORGANICALLY MODIFIED CLAY AND POLY (ETHYLENE OXIDE) THAT HAVE A VISCOSITY OF CAST REDUCED AND IMPROVED STABILITY TO AQUEOUS FLUIDS AND A PROCESS OF A STEP TO MAKE THE SAME CROSS REFERENCES TO RELATED REQUESTS This application claims the benefits of the provisional patent application of the United States of America No. 60 / 114,312, filed on December 31, 1998, and the provisional patent application of the United States of America.

No. 60 / 114,333, filed on December 31, 1998.

FIELD OF THE INVENTION The present invention relates to compositions comprising clay and polymer particles that respond to water. Particularly the present invention relates to compositions comprising a mixture of a water-responsive polymer, which is optionally environmentally degradable, and organically modified particles selected from the group consisting of organically modified clays, organically modified silicates and mixtures thereof and processes for making such compositions. In one embodiment, the polymer that responds to water is a polymer of ethylene oxide. In another embodiment, the polymer that responds to water is a graft copolymer of ethylene oxide.

BACKGROUND OF THE INVENTION Disposable personal care products such as liners, diapers, caps, etc. They are of great convenience. Disposable products provide the benefit of sanitary use at one time and are convenient, and quick and easy to use. However, the disposition of the products is a concern. Incineration of products is undesirable because concerns increase about air quality and costs and the difficulty associated with separating incinerable products from non-incinerable products. Throwing away products is also very desirable due to the concerns of limited land fill space and increased land cost. As a result, there is a need for a disposable product which has been discarded quickly and conveniently without being thrown on the land or incinerated.

It has been proposed to dispose of these products in municipal and private drainage systems. Ideally, these products will be disposable with water discharge and desirably biodegradable in conventional drainage systems. Articles suitable for disposal in drainage systems that can be discharged with water discharge in conventional toilets can be discarded with water discharges in conventional toilets are called "disposable co-discharge water." Disposal by disposal of water discharge provides the benefit of providing simple, convenient and sanitary means of disposal.

Disposable products with water discharge may have sufficient strength under the conditions in which they will be used. Therefore, it is desirable that the disposable personal care products withstand the high temperature and humidity conditions encountered during use, but that lose their integrity in contact with water in the toilet. It is also desirable that these personal care products are disposable with water discharge in order to avoid the accumulation of perspiration and increase the comfort level of the consumers of these products. Thus, a breathable material having a mechanical integrity with a capacity to breathe that has a mechanical integrity when dry and that disintegrates easily with immersion in water is highly desirable.

Due to its unique interaction with body fluids and water, poly (ethylene oxide) hereinafter PEO) is currently being considered as a component material for water sensitive compositions. Pol (ethylene oxide) - (CH-CH20h-) is a commercially available water-soluble polymer that can be produced from a ring-opening polymerization of ethylene oxide O / \ CH2-CH2 Due to its solubility in water and its ability to breathe, polyethylene oxide is desirable for personal care and disposable applications. Although conventional polyethylene oxide films are not as stable to the fluid as are desired for many personal care applications and are difficult to process using conventional processing techniques, modified polyethylene oxide compositions are being developed in such a way that are applicable to the conventional fading process. There is still a need to further improve the stability in the liquid of water-degradable and water-responsive polymer compositions.

Many have tried to overcome these difficulties. The patent of the United States of America No. 4. 902,553 issued to Hwang et al. Describes disposable articles comprising a vapor-permeable and liquid-impermeable film. The vapor permeable and liquid impermeable film described by Hwang et al. Comprises a stretchable and crystallizable polyolefin-based film and a noise-reducing additive which may be poly (ethylene oxide). However, the liquid-permeable and vapor-permeable films of U.S. Patent No. 4,902,553 require at least one nucleating agent which may be talc or calcium carbonate and the stretch to achieve the capacity for breathe. The amounts of the nucleating agent are limited to very small amounts, from 0.05 to 5 percent by weight. These amounts of inorganic nucleating agent are insufficient to be defined as fillers. In addition, stretching is required to generate the porosity and therefore the ability to breathe and the subsequent bleaching of the noise reducing agent is desired. In contrast, the films of the present invention do not require stretch for breathability and do not necessarily require a nucleating agent or a crystallizable polyolefin. Normally, the vision of the inorganic filler to a polymer without stretching to create gaps does not increase the ability of the polymer to breathe. Conventional fillers such as mica, calcium carbonate and kaolin are not expandable. Many of these conventional fillers are plate-like in shape and provide barriers to the diffusion of air and vapors.

U.S. Patent No. 3,895,155 describes coated transparent plastic articles. The clear plastic can comprise poly (ethylene oxide). An organic protective coating is applied as a separate layer on the transparent plastic article to improve the surface hardness, increase the resistance to stretching, and facilitate non-clouding. The inorganic protective coating may comprise several metal oxides. However, the coating forms a glass-like layer and is separated from the transparent plastic article and the resulting coating on the articles is not breathable and is not disposable with water discharge.

U.S. Patent Nos. 5,075,153, 5,244,714 and 5,672,424 to Malhotra et al. Describe coated or multi-layered recording sheets designed for electrostatic printing processes. The recording or recording sheets comprise a base sheet with an unsightly layer which can be made of poly (ethylene oxide). The recording sheets comprise an additional toner receiving layer which comprises inorganic oxides such as silicon dioxide, titanium dioxide, calcium carbonate, or the like.

The poly (ethylene oxide) and the inorganic oxides are contained in separate layers, the antistatic layer and the toner receiving layer respectively. The sheets for recording have no capacity to breathe nor are they disposable with water discharge.

The patent No. 4,276,339 issued to Stoveken describes a laminated product comprising a paper layer and a foamed layer. Poly (ethylene oxide) is described as one of many possible components of an aqueous latex dispersion from which the foamed layer is made. Inorganic fillers such as clay or silica are suggested as possible additions to the aqueous dispersion of the latex in order to increase the solids content and the density of the aqueous dispersion of the latexes. The aqueous dispersion from which the foamed layer is made must be capable of being foamed and requires foaming in order to be able to breathe.

The water-degradable, breathable compositions currently available are not stable when in contact with aqueous fluids as desired for many personal care applications. There is a need in the art to provide compositions that respond to water with controlled stability in aqueous fluids and a means to improve the stability of resins that respond to water in contact with aqueous fluids. What is required in the art is a method for making and controlling the stability and degradability of resins that respond to water when in contact with aqueous fluids and to their method for improving the processing of compositions that respond to water, degradable and with ability to breathe.

SYNTHESIS OF THE INVENTION The present invention provides compositions that respond to water with improved stability in aqueous fluids and a method for producing compositions with controlled mechanical and / or structural stability when in contact with aqueous fluids. The compositions of the present invention comprise a mixture of at least two components: (1) a polymer that responds to water and (2) organically modified clay particles and / or silicate particles in organically modified layers. Polymers that respond to water include polymer and copolymers of ethylene oxide and other polar polymers whose properties degrade when exposed to water and aqueous solutions. Suggested water-responsive polymers include polar polymers with ester groups including polyesters and degradable polylactides. Desirably, the polymer that responds to water is biologically degradable in a particular and environmentally degradable manner. Organically modified clays include the organically modified clays of the smectite group such as montmorillonites and bentonites. The compositions, films, fibers and articles made by the method of the present invention have controlled degradation and improved stability when contacted with aqueous liquids, fluids and droplets. In addition, the compositions of the present invention provide improved mechanical stability when exposed to aqueous fluids, including liquids and vapors. These improvements make the compositions of the present invention more suitable for applications on films, fibers and disposable articles with water discharge. An unexpected benefit of the addition of organically modified clay to poly (ethylene oxide) is the improved melt processability. of poly (ethylene oxide).

Surprisingly, the addition of the organically modified arcill or the silicate particles in layer to the poly (ethylene oxide) improves the melt processability of the poly (ethylene oxide). Normally, the unmodified poly (ethylene oxide) reams are not extrudable especially at high and ultra high molecular weights, including up to 8,000,000 grams per mole of viscosity average molecular weight. The grammatical improvements in the melt processing of poly (ethylene oxide) are observed with the addition of organically modified clay particles to the poly (ethylene oxide) resin having average molecular weights of 1,000,000 grams per mole to 8,000. .000 grams per mole The compositions, films and fibers made from the present invention are especially useful for the manufacture of personal care articles with potential disposable and compostable applications or environmentally degradable, such as diapers, feminine pad, panty liners, underpants pair training, and other environmentally degradable and disposable components and compositions with water discharge. Other suggested uses for the compositions, films and fibers of the present invention include the manufacture of articles for health care, such as bandages, gowns and wound dressings.

In the key variables affecting the fluid stability of the compositions of the present invention, they include, but are not limited to filler type, filler particle size and distribution size, filler expansion and swelling efficiency, interaction of filler with the polymer and the associated water, and the molecular weight and filler selection and swelling efficiency, interaction of filler with the polymer and the associated water, and the molecular weight and selection of the polymer components respond to water. In an embodiment of the present invention, the filling particles desirably have an average particle size which is not more than about 50 microns. More desirably, the filler particles have an average particle size that is no more than about 10 microns. Even more desirably, the filler particles have an average particle size that is no more than about 5 microns. The reduced particle sizes provide improved dispersion and processing.

BRIEF DESCRIPTION OF THE FIGURE Figure 1 is an X-ray diffraction pattern of unmodified clay.

Figure Ib is an X-ray diffraction pattern of an unmodified clay compound and poly (ethylene oxide).

Figure 2 is an X-ray diffraction pattern of an organically modified clay compound and poly (ethylene oxide).

Figure 3 is an SEM image of a cross section of a film comprising a mixture of poly (ethylene oxide) and organically modified clay particles.

Figure 4 is a bar graph illustrating the dramatic reduction in water permeability of poly (ethylene oxide) that can be achieved by the incorporation of organically modified clay into poly (ethylene oxide).

Figure 5 is a bar graph illustrating the relative water permeabilities of three examples of poly (ethylene oxide) and organically modified clay compositions of a particular molecular weight against the same molecular weight, of poly (ethylene oxide) not filled and of a compound of the same molecular weight of poly (ethylene oxide) an unmodified clay.

Figure 6 is a bar graph illustrating the effect of the molecular weight of poly (ethylene oxide) on the permeability of water.

Figure 7 is a bar graph illustrating the effect of the concentration of the organically modified clay in the clay / poly (ethylene oxide) monocomposites on the water permeability.

Figure 8 is a bar graph illustrating the effect of the optional addition of the water repellent additives to a clay / poly (ethylene oxide) nanocomposite on the permeability of water.

Figure 9 is a bar graph illustrating the effect of organically modified clay composition on the nanoco position of clay / poly (ethylene oxide) on the permeability of water.

DETAILED DESCRIPTION OF THE INVENTION The compositions of the present invention comprise at least two components: (1) a polymer which responds to water and (2) organically modified particles such as organically modified clays, silicates and layers and mixtures thereof. In an example embodiment, the polymer that responds to water is an ethylene oxide polymer. The addition of organically modified layer silicate particles and / or the organically modified arcill particle to the water soluble ethylene oxide polymers provides controlled degradation and improves the mechanical and structural stability of the polymers in contact with liquids. watery Significantly and unexpectedly, the addition of the organically modified clays or the layered silicate particles improves the melt processing of the ethylene oxide polymers, particularly the high and ultra high molecular weight ethylene oxide polymers., for example from 1,000,000 to 8,000,000 average molecular weight grams / mol. The compositions and methods described herein are useful for making both environmentally degradable and disposable items with breathable water discharge such as disposable diapers, women's pads, panty liners, etc. specifically, the compositions and methods described herein are useful for producing films, fibers and articles employing standard extrusion processes which have improved stability to aqueous liquids and which are disposable with water discharge and optionally are environmentally degradable. Additionally, the compositions and processes described herein can be used for non-disposable applications with water discharge such as the manufacture of biodegradable materials and biodegradable films with a controlled immobilization of fluids and materials with a controlled interfacial behavior and surface properties.

The process for making films, fibers of other articles according to the present invention includes the preparation of a nanocomposite having a unique micro structure and is formed by melt mixing, particularly extrusion, of a polymer that responds to water organically and organically modified clay particles or silicate particles in organically modified layers or mixtures including such particles. The polymer component of the nanocomposite forms the matrix of the resulting compound. Although the present invention is demonstrated in the following examples by the use of poly (ethylene oxide), other known degradable polymers and other water-responsive polymers can be used as the polymer component that responds to the water in the mixture. Suggested water-responsive polymers include but are not limited to ethylene oxide polymers, particularly homopolymers, modified polymers and graft copolymers of ethylene oxide; the vinyl alcohol polymers, the polylactides and the mixtures and combinations thereof. Desirably, the water-responsive polymer is a copolymer or polymer that responds to the water of ethylene oxide, more desirably, a homopolymer or a graft copolymer of ethylene oxide. As used herein, the term "polymer" includes homopolymers, copolymers, terpolymers and modifications thereof.

The selection of the degradable polymer of the water-responsive polymer is based on consideration of key variables such as water solubility, biodegradability, controlled molecular weight, melt processing, strength and ductility. In the following examples, several commercially available resins of poly (ethylene oxide) (sometimes abbreviated as PEO) were selected as the polymer component of the mixtures of the present invention. However, the scope of the present invention is not limited to poly (ethylene oxide) and can be expanded to other polar or ionic polymers, to other water-soluble or water-degradable polymers and to other degradable polymers which can be interspersed with the clay particles. Additionally, if poly (ethylene oxide) is selected as the base ream of poly (ethylene oxide) it can be chemically modified by grafting, reactive extrusion, block or branching polymerization to improve its melt processability and performance in a solid state. The poly (ethylene oxide) resins can be modified by reactive extrusion or grafting as described in the co-pending application of the United States of America Series No. 09/002/197, which was incorporated herein by reference in its entirety Optionally, the polymer that responds to water is dispersible in water or soluble in water. The polymer that responds to water, for example poly (ethylene oxide) can be mixed with other polymers that respond to water and environmentally biodegradable polymers.

As used herein, the term "water dispersible 2" refers to the ability of a polymer, composition, film, article, etc. to dissolve or break into smaller pieces of 20 Maya after being submerged in water for approximately 30 minutes. The term "water-disintegrable" refers to the ability of a polymer, composition, film, article, etc. to break into multiple pieces within 30 minutes of the investment in water, where some of the pieces are trapped by a 20 mesh grid without the slipping in the same way as a thread through the needle blade The term "water weakening" refers to the ability of a polymer composition, film, article, etc. to remain in a piece, but weaken and lose stiffness after 20 minutes of immersion in water and become drapeable, for example, bend an external force applied to it when it remains on one side in a position horizontal ion The term "stable in water" refers to a polymer, composition, film, article, etc. which does not become drapeable after 30 minutes of immersion in water and remains in one piece after the water response test. Here, the term "responsive to water" refers to compositions, films, articles, etc., which are water-soluble, water-dispersible, water-insoluble or water-weakening. "Environmentally degradable," as used herein in relation to a composition or article means that the composition or article is degradable under the action of water, heat or naturally occurring microorganisms so that the significant change in the structure of the material, including a reduction in molecular weight or a change in a chemical structure or a significant loss of properties such as mechanical integrity, mechanical strength, stiffness or elasticity mode, fragmentation occur.

The polymers that respond to water and the compositions of the present invention are desirably environmentally degradable. More desirably, the polymers compositions corresponding to the water of the present invention are also melt extrudable. The polymers that respond to water and the compositions of the present invention may include compositions that respond to water, mixtures and combinations that incorporate such polymers. The degradable polymers and the compositions of the present invention should be desirably melt extrudable so that the polymer can be extruded and processed into films. The term "melt extrudable" as applied herein to the polymer and compositions means that the polymer and composition is a thermoplastic material having a melt flow rate (MFR) value of not less than about 0.2 gram per gram. minutes, based on the ASTM DL1238 standard. More particularly, the melt flow rate value of melt extrudable polymers ranges from about 0.2 grams per 10 minutes to about 100 grams per 10 minutes. Desirably, the melt flow rate value of suitable melt-extrudable polymers ranges from about 0.4 grams per 10 minutes to about 50 grams per 10 minutes, and desirably, varies from about 0.8 grams per 10 minutes to about 20 grams per 10 minutes to provide the desired levels of processability.

Desirably, the polymer that responds to water is permeable to water vapor when it is in the form of a film. Suitable water-responsive polymers are characterized by being water-dispersible soluble in water or by having tensile properties, such as tensile strength and stress modulus, which essentially fall when the polymer, in the form of a film, and moistened with water. When dry, however, the polymer that responds to water maintains its shape and integrity with a film. Polymers that respond to the desired water include water-soluble and water-dispersible polymers which disintegrate in water. Desirably, polymers that respond to water disintegrate in water for less than about 5 minutes. Suitably, water-responsive polymers include polyethylene oxide, ethylene oxide and polypropylene oxide copolymer, other ethylene oxide copolymers that respond to water, mix that respond to polyethylene oxide water, classes that respond to water of polyvinyl alcohol, polyvinyl alcohol mixtures, of poly (vinyl pyrrolidone) polyetheloxazole to branched water-degradable polyesters and copolyesters in water, water-dispersed polyurethanes, water-degradable acrylic acid base copolymers, polyvinyl methyl ether dispersible in water water, cellulose derivatives such as methyl cellulose, hydroxypropyl cellulose, methylated hydroxypropyl cellulose, hydroxypropyl ethyl cellulose and ethyl celluloses and the like.

Suitable biologically degradable polymers are characterized by being degraded in the presence of naturally occurring micro organisms so that the films break into smaller pieces or significantly lose the strength so that if the film is placed in a biologically active environment, For example, co-positioning and sludge digestion, the film will break. Biologically degradable polymers useful in the present invention include, but are not limited to polycaprolactone, polybutylene succinate, poly (butylene-adipate succinate) poly (lactic acid), polyhydroxybutyrate-co-valerate, polyethylene adipate, propylene succinate, copolymers of polylactic acid-poly (ethylene oxide), and mixtures and combinations thereof. The biologically degradable polymers can be blended or otherwise combined with water-responsive polymers or water-soluble polymers, to improve the water response of the overall composition. Specific examples of the biodegradable resins useful in the present invention include, but are not limited to, the polycarprolactone resin TONE5 P-787 from Union Carbide, and the BIONELLE * 1 1003, 3001 and 3003 resins from Showa Highpolymer, Japan.

The polymer that responds to the water illustrated in the examples to make a polymer film that responds to water is poly (ethylene oxide). Poly (ethylene oxide) grafted or chemically modified is also suitable. The poly (ethylene oxide) chemically modified or grafted resins and their methods for making them are described in the applications of the United States of America Patent No. 09/001. 0c, 09 / 001,831 and 09 / 002,197, whose descriptions of which are incorporated herein in their entirety The suggested modified and unmodified poly (ethylene oxide) resins useful as the water-responsive polymer component of the present invention desirably have molecular weights ranging from about 1000 grams per mole at about 8. OCO grams per mole (hereinafter abbreviated as g / mole) More desirably, the modified and unmodified poly (ethylene oxide) ends useful as the water-responsive component of the present The invention should have molecular weights ranging from about 400,000 grams per mole to about 4,000,000 grams per mole. Poly (higher molecular weight) ethylene oxide reams These ranges are desirable to increase liquid stability, increased mechanical strength and ductility.

While the reams of poly (ethylene oxide) of lower molecular weight provide better flow and film forming properties. Taking these factors into consideration, an even more desirable range of molecular weights of the poly (ethylene oxide) as the water soluble polymer component is from 200,000 grams per mole to about 2,000. OCO grams per mole.

A commercial supplier of poly (ethylene oxide) resins is Union Carbide Chemicals and Plastics Company, Inc. Examples of suitable available poly (ethylene oxide) caries of carbide bonding include, but are not limited to, the reams sold under the following trade designations reported average molecular weights: POLYOX - WSR N-80, a polyethelene oxide of 200,000 grams per mole, POLYOX® WSR N-750, or poly (ethylene oxide 300,000 grams per mole; the POLYOX® WS N-3000, a poly (ethylene oxide) of 400,000 grams per mole, POLYOX® WSR 205, a poly (ethylene oxide) of 600,000 grams per mole, POLYOX® WSRN-12K a poly (oxide of ethylene) of 1,000,000 grams per mole, POLYOX® WSR N-60K a poly (ethylene oxide) of 2,000,000 grams per mole, POLYOX ® WSR N-301 a poly (ethylene oxide of 4,000,000 grams per mole) and POLYOX® WSRN-308 a poly (ethylene oxide) of 8,000,000 grams per mole. (See also POLYOX® water-soluble reams, from Union Carbide Chemical & Plástic Company, Inc. 1991 which is incorporated by reference herein in its entirety). All reams of poly (ethylene oxide) are provided in powder form by Union Carbide. Both the poly (ethylene oxide) powder and the poly (ethylene oxide) pellets can be used in the present invention.

The water-repelling polymer reams employed in and compositions, films and articles of the present invention may optionally contain various additives such as plasticizers, processing aids, solid state modifiers, rheology modifiers, antioxidants, ultraviolet light stabilizers, pigments, dyes, slide additives, antiblock agents, polymer emulsions, etc. These additives can be added before, during or after the mixing of the filler particles and the ream that responds to water. For example, water repellent additives of various compositions such as fluorosilicones, organosilicones, other fluorochemicals, and waxes especially, may be added to the compositions of the present invention to further increase the liquid stability of the compositions. Desirably, the water repellent additives can be added to the compositions of the present invention in amounts ranging from about 0.5 percent to about 10 percent by weight of the composition based on the sum of the weights of the polymer that responds to water and the particle filler material. More desirably, the water repellent additives can be added in the range of from about 1 percent to about 5 percent by weight of the composition. Commercial examples of the water-repellent additives include but are not limited to the fluorochemical FX-1801 supplied by 3M and the fluorinated melt additive TLF-3860 supplied by DuPont. Additionally, various surfactants can be added to the ream of polymer that responds to water before, during or after combination with the inorganic filler to control the interaction of the control resin with the inorganic filler and to improve the dispersion of the filler.

The present invention is demonstrated in the following examples by the use of various kinds of poly (ethylene oxide) that respond to water. The examples use poly (ethylene oxide) resins with reported average molecular weights ranging from as low as about 200,000 grams per mole to as high as about 8,000,000 grams per mole. Normally, the ultra high molecular weight classes polyethylene oxide, from about 1,000,000 to about 8,000,000 grams per mole, are not easily extruded and degraded under conventional extrusion conditions. Surprisingly the addition of the clay filler particles to the poly (ethylene oxide) resins lowers the melt viscosities of the resins and thus facilitates the processing and extrusion of the melt of the resins. The reduction of the surprising melt viscosity and the improvement in the melt influx properties is particularly important in the process of melting ultra high molecular weight polyethylene oxide resins and facilitates melt processing and extrusion of the Poly (ethylene oxide) resins of high ultra high molecular weight. Films, fibers and other articles can be processed directly from poly (ethylene oxide) powders without the need for auxiliary or additional processing steps. Advantageously, the reduction of fluid viscosity and the improvement in the melt flow properties brought about by the addition of the organically modified clay filler allow the high and ultra high molecular weight poly (ethylene oxide) reams to be pelletized. These same benefits have been observed with the grafting of poly (ethylene oxide) and are discussed in the co-pending application mentioned above which describes the grafted poly (ethylene oxide). However, unlike grafted poly (ethylene oxide) compositions, the poly (ethylene oxide) -filled compositions filled with clay of the present invention are not believed to have significantly altered molecular weights and significantly altered molecular weight distributions.

The inorganic filler component or components of the compositions of the present invention form the dispersed phase of the compound. Desirably, at least one of the fillers is an organically modified clay or an organically modified layered silicate. The selection of filler material is based on consideration of key parameters including, but not limited to, particle size, expansion and swelling efficiency and interaction with the polymer. Smectite group clays, such as the various forms of montmopillonites and bentonites are desirable for the present invention. In an embodiment of the present invention, the silicat filler layered with the clay desirably has an average particle size which is not more than about 5 microns. More desirably, the average particle size is not more than about 10 microns, and even more desirably, the average particle size is no more than about microns to provide improved dispersion and procesability. Also desirably, the stuffing particles comprise bunches or small fin sheaths which are polar. The term "polar dion" as used herein applies the inserts and means that the inserts have different charges on the flat surfaces, desirably positive charge are on the edges of the inserts and the negative charges are on the flat surfaces of the inserts. Bunches and plate herds desirably have high aspect ratios. The aspect ratio of a plaquit is the ratio of the surface width of a particle to the thickness of the particle. The aspect ratio is desirably not less than about 3: 1. More desirably, the aspect ratio is not less than about 5: 1 and more desirably is not less than about 10: 1. In other aspects of the present invention, the aspect ratio is not more than about 15,000: 1, more desirably no more than about 5,000: 1 and even more desirably no more than about 2,000: 1.

Smectite group clays, such as montmorillonites and bentonites are suggested for the present invention. The sodium cation in the spaces between layers of montmorillonites can be exchanged with organic cations to give organically modified montmorillonites with a spacing of between expanded layer and an interaction made with a polymer resin. Such organically modified clays are more organophilic than the unmodified clays. The organic cations may contain reactive groups thereby providing inorganic / organic nanomers, for example nanosized particles capable of reacting with the polymer matrix and having the potential for polymerization and / or grafting to the matrix polymer. Alternatively, the clay filler can be modified with intercalary organic polar polymers that do not have intercalating cations. Such polar polymers can be used individually to modify the clays or in combination with the polar polymers containing the intercalating cations. Organic polar polymers can be interspersed in the spaces between layers of a clay to produce an organically modified clay. Unmodified smectites as well as organically modified and expanded ones can also be incorporated into the compositions of the present invention. Organically modified clays provide much better dispersion in water-responsive polymers and greater mechanical and structural stability during exposure to aqueous liquids compared to unmodified clays as a result of an elaborate polymers silicate interaction, a greater basal spacing and a controlled hydrophobicity. Also during the melt processing of organically modified clays these can provide improved dispersion during the melt processing of the individual fine modified clay plates and of the bundles and modified clay plate sheds in the water-responsive polymer matrix.

Other particulate fillers may also be incorporated into the compositions of the present invention. These other particulate fillers include, but are not limited to, calcium carbonate, karate to kaolin, talc to titanium dioxide, etc., which can be subjected to surface treatment with various coatings and surfactants to impart an affinity to the polymer ream and make the properties water repellent. However, such fillers can be significantly less efficient in controlling the sensitivity of a polymer that responds to water to aqueous liquids compared to less effective organically modified clay fillers to improve melt processability.

Examples of the commercially available clay materials usable in the present invention include but are not limited to one or more of the following: Polargel NF T clay, a highly efficient form of commercially available white bentonite available from the Kraft Chemical Company of Melrose Park, Illinois; Polargel NF clay, a highly purified bentonite commercially available from Kraft Chemical Company of Melrose Park, Illinois; Suspengel Ultra clay, a highly purified bentonite commercially available from Cimber. Performance Minerals of Cartersville, Georgia; Betonite clay H, a highly activated montmopillonite, commercially available from Southern Clay Products, Inc., of Gonzales, Texas. Examples of the commercially available synthetic clays usable in the present invention include various kinds of laponite, a colloidal synthetic layered silicate from Southern Clay Products, Inc.

Clay particles having a pretreated or organically modified surface typically absorb or interact with organic substances more readily and are desirable as the organically modified clay component of the present invention. Clay particles having a pretreated or organically modified surface are generally preferred as the organoclays. The organoclays exhibit increased compatibility with polymers that respond to water. The organically treated treated or modified clays mcluyen, but are not limited to one or more of the following. Organoarcilla Claytone APA, dimethylbenzyl ammonium bentonite ^ tallow hydrogenated) of free activator; bentonite modified quaternary ammonium compound, free activator Claytone HY; ammonium bentonite (hydrogenated tallow) dimethyl bis Claytone 40; and the organically modified clays SCPX-1121, SCPX-1122, SCPX-1123 obtained from Southern Clay Products, Inc., of Gonzales, Texas.

Although the organically modified clay particles and the layered silicate particles have a stronger affinity for the polymers that respond to water and are required to improve the stability of the compositions of the present invention during exposure to aqueous fluids, the Additional conventional fillers can be added to the compositions of the present invention to modify and control the porosity. In addition to the organically modified clay and / or the layered silicate component of the compositions, conventional fillers can be added to the compositions of the present invention in order to change the appearance, opacity or softness of the compositions and are also considered within of the scope of the present invention. Conventional fillers include, but are not limited to, calcium carbonate and titanium dioxide. The calcium carbonate filler employed in the examples is SUPERMITE® calcium carbonate filler, which is commercially available from ECC International of Sylacauga, Alabama. The calcium carbonate filler particles can be surface modified with a surface modifying agent, such as a silicon glycol copolymer to reduce the surface tension of the particles and improve the interaction with the fluids. It is possible to modify the surface of the filling particles with a surface modifying agent having a hydrophilic / lipophilic balance number (hereinafter abbreviated as HLB) ranging from 0 to about 15, desirably having a hydrophilic balance number -lipophilic from about 6 to about 13. Liquid organosilicones suitable as surface modifying agents are generally available from Dow Corning of Midland, Michigan. The particulate filler material including the organically modified clay is suitably present in the composition of the present invention in an amount of from about 1 percent to about 70 percent by weight relative to the sum of the weight of the polymer that responds to the water and particulate filler material. Desirably, the amount of the filler material is from about 5 percent to about 60 percent by weight and even more desirably is from about 10 percent to about 50 percent by weight of the filler in relation to the sum of the weight of the polymer that responds to water and the particulate filler material.

The polymer component employed in the compositions of the present invention can be suitably intermixed with the filler in pellet powder form otherwise combined using conventional mixing and blending techniques. Desirably, the water-responsive polymer component is mixed with the inorganic filler or fillers prior to melting. The mixture is then mixed with melt in a suitable apparatus such as a mixer, a single screw extruder, a twin screw extruder, etc. In the following examples, the processes for mixing the water-responsive polymer and the inorganic filler are demonstrated on a laboratory-scale twin screw extruder obtained from Haake, of Paramus, New Jersey. However, other types of apparatus suitable for mixing inorganic polymers and fillers can be used to produce the compositions according to the present invention. Films or sheets of the compositions can be manufactured by convenient techniques such as compression molding and / or extrusion setting.

The selection of the processing equipment for the preparation of the compositions and films of the following examples is based on the main requirements such as high-cut melt processing, sufficient residence time for mixing and the potential for rate processing high. Desirably, the component materials, the poly (ethylene oxide) resin and the inorganic particle filler, are suitably intermixed before the melt. However, the components of the compositions of the present invention can be supplied separately in the melt processing apparatus. Conventional extruders have separate feeders and are suitable for preparing the compositions of the present invention.

The process for preparing the compositions is demonstrated in a laboratory scale Haake twin screw extruder described herein. The Haake twin screw extruder comprises a pair of taper screws tailored to provide a high melting cut and increased residence time. A general description of the twin screw extruder Haake is provided as follows. The twin screw extruder Haake comprises six sections. Section 1 comprises a double-section forward pumping section having a large screw forward inclination and a high helix angle. Section 2 comprises a double-section forward pumping section having a screw inclination that is smaller than the screw inclination of section 1. Section 3 comprises a double-section forward pumping section having a screw inclination. which is smaller than the screw inclination of section 2. Section 4 comprises a section of reverse pumping with notches and double section having a complete section with notches. Section 5 comprises a front pumping section with double-section notches having two complete sections. Section 6 comprises a double-section forward pumping section having an intermediate screw pitch between the screw inclination of section 1 and the screw inclination of section 2. The Haake twin screw extruder has three heated extrusion zones with air cooling. The supply section of the extruder is water cooled to prevent premature melting of the polymer resin. At the end of the extruder, a yarn array with two holes, each 3 millimeters in diameter, was fitted to the extruder to produce the extruded yarns of the compound. The extruded yarns are cooled on a conveyor belt cooled by a fan and then pelletized.

Dry blends of polymer pellets responsive to water or water-responsive polymer powders and filler are prepared with filler filler levels in a range of from about 10 to about 50 percent by weight. filler to the weight of the polymer resin and filler material. Desirably, the fill level of the filler is less than about 80 percent by weight of the filler to the weight of the polymer resin. The dry mixes are fed with flooding inside the twin screw extruder operating at a rate in the range of about 45 to 55 revolutions per minute. For examples comprising poly (ethylene oxide) POLYOX® WSR N-80, the extruder temperatures are set at 120 ° C, 150 ° C, 150 ° C and 150 ° C for the first, second heating zone and third and matri respectively. For the examples comprising the higher weight POLYOX® WSR N-12K and WSR N-308 resins, the extruder temperatures are set at 170 ° C, 180 ° C, 180 ° C and 180 ° C for the first heating zone , second and third and for the matrix, respectively. After extrusion, the filled poly (ethylene oxide) compositions are pelleted and fed through the extruder a second time. During the second extrusion, the extruder operates at a higher rate of about 75 to 95 revolutions per minute. The second extrusion produces uniform threads that have smooth surfaces. The processing design described above allows the processing of poly (ethylene oxide) and clay compounds or high cut conditions and a sufficient residence time using the extruder at a short laboratory scale. Although the compositions of the present invention are prepared by multiple extrusion, it is understood that a second extrusion is not necessary to produce the compositions of the present invention.

Disposable water-discharge and breathable films can be manufactured from poly (ethylene oxide) compositions using conventional filmmaking techniques such as compression molding and extrusion-setting without stretching, foaming or phase separation techniques. In the examples, the films are prepared from the previously extruded poly (ethylene oxide) pellets filled with clay using the Haake laboratory scale extruder described herein. The Haak extruder has a shorter processing time and a shorter processing and combining time than desired. It is understood that films having an increased liquid stability can be formed directly from organically modified clay filler particles and from a polymer that responds to water using a larger extruder that is capable of mixing the components and, optionally, setting a film of the mixture of the components in one step. Such an extruder is available from American Leistritz Extruder, Inc. of Somerville, New Jersey. Advantageously, breathable and disposable films with water discharge can be melted and processed directly from a dry blend of the components in the processing step without pelleting, stretching, foaming or phase separation techniques or other additional processing. Even more advantageously, resins that respond to high and ultra high molecular weight water, for example, poly (ethylene oxide) with average molecular weights of up to about 8,000,000 grams per mole, can be processed in a processing step from a mixture dry that comprises organically modified clay and resin that responds to water. The addition of organically modified clay to resins that respond to high and ultra high molecular weight water can dramatically improve melt flow characteristics, reduce melt viscosity, and reduce melt fracture of resins that respond to water. The addition of the modified clay to the high and ultra high molecular weight poly (ethylene oxide) provides a method for producing yarns and articles having smooth uniform surfaces directly from high molecular weight and ultra high molecular weight poly (ethylene oxide) resins without the addition of plasticizers or other processing additives.

A unique structural arrangement has been discovered in the poly (ethylene oxide) and organically modified clay compositions of the present invention. X-ray, SEM and TEM measurements revealed that the clay plates and the clays or bunches of clay plates in the compositions of the present invention are dispersed in the poly (ethylene oxide) matrix. In contrast, the X-ray measurement of an unmodified montmorillonite clay illustrated in FIG. 1 provides a repeating unit, spacing d, of 12.51 angstroms and an X-ray measurement of an unmodified clay compound and poly ( ethylene oxide) shown in Figure Ib provides a repeating unit, a spacing d of 18.34 angstroms. The same X-ray measurement of an organically modified clay compound and poly (ethylene oxide) shown in Figure 2 did not detect d clay reflections. The same X-ray measurement of an organically modified arcill compound and poly (ethylene oxide) shown in Figure 2 did not detect clay reflections in the small angle scattering region of values of 2 theta below 8 degrees. This suggests that the clay chips in a melt-processed composition, eg, extruded, water-responsive polymer and organically modified clay are not assembled in the form of a crystal with the distinguishing repeat unit or spacing d compared to the poly (ethylene oxide) compositions containing only unmodified clays.

The X-ray measurements were made with the X-Ray Siemens D5000 diffractometer equipped with a K-alpha radiation source. These observations indicate the formation of a molecular compound in the compositions of organically modified clay and poly (ethylene oxide). These observations also indicate that organically modified clay particles in the poly (ethylene oxide) and organically modified clay compound either expand to a spacing value d, higher than is detectable with the instrument configuration used or the Amorphous dispersion of the clay plates is achieved in the poly (ethylene oxide) compound and the organically modified clay.

Figure 3 is a SEM micrograph of a poly (ethylene oxide) and organically modified clay composite according to the present invention. The SEM measurement indicates a wavy nanodispersion shape of the clay inserts and d the clays and bundles of clay inserts in the poly (ethylene oxide) and organically modified clay compositions of the present invention is achieved. The micrograph indicates a nanodispersion of fine bundles of clay plates with a thickness of about 10 nanometers and a dimension d surface on the order of 0.5 to 2 microns is achieved in the composite shown in Figure 3. The separation between the wavy plates it is observed with a separation in the rang from several hundred angstroms to hundreds of nanometers. The unique amorphous nanoscale dispersion of the organically modified arcill plates and the organically modified clay plates and bundles in the poly (ethylene oxide) matrix as demonstrated by the X-rays and the SEM analysis, achieved as a result of a specific interaction between the modified clay plates and the poly (ethylene oxide) molecules. It is believed that this strong specific interaction between the poly (ethylene oxide) ream molecules that responds to water and the organically modified clay particles provides improved stability and controlled degradability of the ream that responds to the water when in contact with it. with fluids and aqueous fluids, including vapors. The mechanical stability and increased structure of the poly (ethylene oxide) and of the organically modified clay compositions in contact with the aqueous fluids is also related to the penetration rate of the aqueous fluids within the structure comprising the poly (ethylene oxide). ethylene) and organically modified clay.

The stability of the compositions of the present invention in contact with aqueous fluids and a fluid penetration rate can be characterized as a penetration rate of liquid fall through the films of the compositions of the present invention. The fluid penetration rate measured as the penetration rate of liquid fall through a film was measured as follows. The liquid penetration rate is estimated using drops of distilled water of 10 microliters and 20 microliters in volume. The average rates of liquid penetration rate through the films of the various poly (ethylene oxide) compositions of a given thickness are presented in Figures 4 and 5. Figures 4 and 5 demonstrate the reduction in permeability of water of the organically modified clay and poly (ethylene oxide) compositions (column 2 of figure 4 and columns 1, 2 and 3 of figure 5). A dramatic reduction of the penetration rate is observed for the poly (ethylene oxide) and for the organically modified clay hybrids of both low and high molecular weights in comparison to the unfilled poly (ethylene oxide) resins and the conventional compositions of poly (ethylene oxide) and calcium carbonate. Figures 4 and 5 also illustrate the effect of the selection of the filler type on the water permeability. A polyethylene oxide compound and Claytone APA organoclay provided the lowest water penetration rate, about 0.01 mils / second compared to 0.05 mils / second for unfilled poly (ethylene oxide) shown in figure 5.

Method and Test of Aqua Penetration Rate To determine the resistance of the compositions according to the present invention to the permeation of liquid water, the water penetration rates of the films of various poly (ethylene oxide) and organically modified clay compositions were measured using a Ring Barrier. The tests were carried out by preparing samples of 3-inch by 3-inch square film. Each film sample was placed on a layer of a pH paper and sealed in a sample holder. The pH paper indicated the presence of water by a change in color. The specimen holder comprises a metal ring with an inner diameter of 5.6 centimeters and a height of 2.5 centimeters. The support, film and paper were grasped with the paper side down to a flat transparent base plate of about 15 centimeters by 15 centimeters with a metal crossbar and with two wing nuts and a pair of bolts. Then, 10 milliliters of distilled water were then poured into the ring and onto the film as fast as possible. The time it took for water or moisture to penetrate through the film and discolor the pH paper below was measured. The rate for water / moisture penetration of a film was calculated by dividing the thickness of the film by the penetration time. A similar procedure was used to evaluate the moisture or water penetration rate through the films of the present invention when the small 10 microliter and 20 microliter water droplets were placed on the film surface.

Example 1 A film according to the present invention was produced from 50 parts by weight of poly (ethylene oxide) resin POLYOX® WSR 308 and 50 parts by weight of Claytone APA organoclay filler. The poly (ethylene oxide) resin POLYOX® WSR 308 was reported as an average molecular weight of about 8,000,000 grams per mole and was supplied as a powder.

The two components, the poly (ethylene oxide) powder and the clay particles, were mixed dry and the resulting dry mixture was supplied with flood in a Haake twin screw extruder as described above. To form a mixture of the combination, the extruder was drilled at a rate e the range of about 40 to 50 revolutions per minute and temperatures of 170 ° C, 180 ° C, 180 ° C and 180 ° C for the first, second and third heating zones and for the matrix respectively. After extrusion, the mixture of poly (ethylene oxide) and clay was cooled. Surprisingly, the dry mix of the higher molecular weight poly (ethylene oxide) powder and the clay filler was easily extruded and produced yarns of a mixture. uniform if previous treatment. The yarns produced by this first extrusion were observed as having smooth surfaces, an indication of the improved melt processability provided by adding the clay filler to poly (ethylene oxide). Ordinarily, poly (ethylene oxide) of this molecular weight is not extrudable without prior treatment, for example, the grafting of poly (ethylene oxide).

The threads were pelleted and molded into 13 mil thick films using a Carver laboratory hot press set at 140 ° C. The film was tested for water penetration using the Ring Barrier Test method described above. The moisture penetration rate for the 13 mil film was around 0.008 mils per second. A localized film hydration was observed for this film, but the film did not fall during the water penetration test.

Example 2 A film of 50 parts by weight of the poly (ethylene oxide) powder POLYOX® WSR 301 and 50 parts by weight of Claytone APA organoclay filler was produced in the same manner as detailed in Example 1 given above. Again, surprisingly, the dry mixture of the clay and the high molecular weight poly (ethylene oxide) was easily extruded and produced uniform poly (ethylene oxide) threads filled with clay. The yarns were observed visually as having very smooth surfaces, an indication of the processability with improved melting. The moisture penetration rate for the film of 13 thousandths of an inch over 4,000,000 grams per mole of poly (ethylene oxide) was about 0.0083 thousandths of an inch per second. A localized film hydration was observed for this film, but the film did not fall during the water penetration test.

The poly (ethylene oxide) resin POLYOX® WSR 301 used in this example had a reported average molecular weight of about 4,000,000 grams per mole and was supplied and used in powder. Not all commercially available higher molecular weight poly (ethylene oxide) resins can be pelletized and provided in powder form. In contrast, the improved melt processability observed in the compositions described herein allows the pelletization of poly (ethylene oxide) reams of higher weight that are not normally pelletable.

Example 3 A film of 50 parts by weight of poly (ethylene oxide) POLYOX® WSR N-60K powder and 50 parts by weight of Claytone APA organo clay filler was produced in the same manner as detailed in Example 1 given above. Again, the dry mixture of clay and poly (ethylene oxide) of high molecular weight was easily extruded and produced uniform threads of the mixture of poly (ethylene oxide) and clay. Additionally, the mixed compound demonstrated high strength and ductility. The poly (ethylene oxide) POLYOX® WSR N-60K ream used in this example was provided and used as a powder and had a reported average molecular weight of approximately 2,000,000 grams per mole. The humidity penetration rate for the film of 10 thousandths of an inch over 2,000,000 grams per mole of poly (ethylene oxide) was about 0.0088 thousandths of an inch per second. A localized film hydration was observed for this film, but the film did not fall during the water penetration test.

Example 4 A film of 50 parts by weight poly (ethylene oxide) powder POLYOX® WSR N-12K and 50 parts by weight Claytone APA organo clay filler was produced in the same manner as detailed in Example 1 given above. Again, the dry mixture of clay and high molecular weight poly (ethylene oxide) was easily extruded and produced uniform threads. The poly (ethylene oxide) POLYOX® WSR N-12K resin used in this example was provided and used as a powder and had a reported average molecular weight of approximately 1,000,000 grams per mole. The moisture penetration rate for the 10 mil film based on 1,000,000 grams per mole of poly (ethylene oxide) of this example was about 0.01 mils per second. A localized film hydration was observed for this film, but the film did not fail during the water penetration test.

Comparative Example A A film of a poly (ethylene oxide) powder POLYOX® WSR N-12K was produced in the same manner as Examples 1-4 given above, but without the addition of the organically modified clay particles. The extruder was operated at the same speed and temperatures. The unfilled, high molecular weight poly (ethylene oxide) was not easily extruded and produced extremely non-uniform yarns. Extruded wires exited the extruder with very rough surfaces indicating a significant melt fracture during extrusion processing. A 7 mil thick film was molded from the poly (ethylene oxide) resin not filled in the use of the same hot press and the same process as described above. The water penetration rate was tested using the apparatus and the method as indicated above. The moisture penetration rate for the unfilled film of 10 mils was about 0.04 mils per second, four times higher than the moisture penetration rate of the filled poly (ethylene oxide) film based on the same poly (ethylene oxide) of molecular weight. More importantly, the dramatic film failure was observed in the formation of numerous macroscopic gaps for this film during the water penetration test. The dramatic film failure was not observed for the films of the present invention, demonstrating the improved stability to liquid penetration of the films of the compositions of the present invention. Improved stability is desirable for personal care applications and allows films and other articles made from the compositions to be handled by the consumer with wet hands before use or otherwise exposed to small amounts of liquid without failure the movies the articles.

Example 5 Measurement and Method of Melting Remorse To further demonstrate the improved processability of the compositions according to the present invention, the melting rheologies of the higher molecular weight organically modified clay poly (ethylene oxide) compositions of Examples 1-4 were measured. Additionally, the melting rheologies of other unfilled poly (ethylene oxide), 2,000,000 grams per mole of poly (ethylene oxide) POLYOX® WSR N-60K were employed in Example 3 and were measured (Comparative Example B). The fusion rheologies were measured using analysis software. A transducer with a pressure of 2000 bars with a capillary matrix with round holes of 30 / 1.0 / 180 was used. The melt viscosities in units of seconds Paséales were measured at 180 ° C and cut-off rates of 50, 100, 200, 1000 and 2000 l / seconds. Measurements of the melting rheologies of the compositions of Examples 1-4 and Comparative Examples A and B are reported in Table 1 given below.

Table 1 FUSION RHEOLOGIES OF TOP MOLECULAR WEIGHT POLY (ETHYLENE OXIDE) RESINS FILLED AND NOT FILLED The observed data reported in Table 1 demonstrate the improved processability, particularly the melt processability of the poly (ethylene oxide) resins filled with organically modified clay against the unfilled poly (ethylene oxide) resins of the same weight molecular. The comparisons of Example 4 with Comparative Example A and Example 3 with unfilled polyYoX® WSR N-60K polyethylene oxide (Comparative Example B), clearly demonstrate that the addition of the organically modified clay to the poly (oxide) of ethylene) significantly reduces the viscosity of poly (ethylene oxide) over a wide range of cutting rates.

Additionally, the stability of the poly (ethylene oxide) hybrids to the aqueous fluids was measured as a rate of fluid penetration through hybrid films compression-molded of controlled thicknesses. The results are presented in figures 6-9. A penetration rate was measured for a controlled volume of liquid on the surface of the film with the volume of the liquid corresponding to 10 microliters, 20 microliters and 10 milliliters. In the latter case, the liquid covered 10 square centimeters of the area of the film with the head of about 1 centimeter. The molecular ultrahigh molecular poly (ethylene oxide) and the organically modified clay hybrids demonstrated a dramatic improvement in liquid stability compared to the unfilled poly (ethylene oxide) resin of average molecular weight of 200,000 as illustrated in Figure 6. The dramatic film failure included the formation of holes and macroscopic voids that were observed for the poly (ethylene oxide) film not filled when the film was in contact with the water. In contrast, only localized hydration and no failure or formation of the hollow film or holes were observed in the case of Claytone APA organoarcilla hybrids and poly (ethylene oxide) hybrids. This indicates that the mechanical and structural stability of the films of the present invention when exposed to aqueous fluids, (such as water) were dramatically increased.

The dramatically increased mechanical and structural stability of the compositions responsive to the water of the present invention in contact with aqueous liquids, including fluids and fluid droplets, is related to the reduced sensitivity and controlled degradability in the water of the ream that it responds to the water of the compositions including the organically modified clay. The increased structural and mechanical stability is also related to the significantly reduced rates of moisture and / or water penetration within the composite structure. In poly (ethylene oxide) films comprising organically modified clay particles, the water penetration rate was reduced by a factor of six and greater, compared to the ream of poly (ethylene oxide) N-80 not carried (see Figure 6). Referring to Figure 6, some increase in the water penetration rate for larger volumes of water did not change the general trend for the reduction of water penetration rate. The level of stability to the liquid can be controlled by the organoclay load as illustrated in Figure 7. The significant improvement in liquid stability of the films in both water and salt water was observed for Claytone APA organoarcilla hybrids. / poly (ethylene oxide) N-80 with the increase of organically modified clay content. With 40 percent Claytone APA organoarcilla, the liquid penetration rate can be reduced by a factor of 5.

Further improvements in structural and mechanical stability during exposure to aqueous liquids can be achieved by modifying the poly (ethylene oxide) / organoclay compositions with the use of water repellent additives. In Figure 8, the effect of the fluorochemical additives on the liquid stability of the hybrid poly (ethylene oxide) / Claytone APA (60/40) hybrid film is illustrated. The addition of 1.5 percent FX-1801 fluorochemical water repellent additive reduces the liquid penetration rate by a factor of 10 compared to the unfilled poly (ethylene oxide) N-80 resin. Even better results are expected for the organoarcilla and poly (ethylene oxide) ultra high molecular weight hybrids. The degradability and sensitivity of poly (ethylene oxide) and organoclay hybrids with aqueous fluids can also be controlled by the composition of the organoclay. In Figure 9, the effect of the organoclay composition on the water penetration rate is illustrated. The effect on the hydrophilicity of the organoclays used in this figure and the accompanying experiment is as follows: the organoclay SCPX-1123 is more hydrophobic than the organoclay SCPX-1122 which is more hydrophobic than the organoclay SCPX-1121. The organoclay, SCPX-1123 is the most hydrophobic and has the greatest effect on water permeability. The more hydrophobic clays provide lower water penetration rates, which may be related to the improved interaction of a more hydrophobic clay modified with poly (ethylene oxide) and a reduced affinity of the modified clay to water. Preliminarily, the data indicate a significant improvement in a structural and mechanical stability of the threads and filaments of the poly (ethylene oxide) / organoclay compositions when they are exposed to the aqueous fluids and liquids compared to the poly resin threads. simple ethylene oxide).

According to certain aspects of the present invention, films capable of breathing can be formed if drawn or foamed. The capacity to breathe of the films can be characterized by the water vapor transmission rate (WVTR). The greater the rate of water vapor transmission of a material, the greater is the ability to breathe of the material. The water vapor transmission rates of more than 500 grams per square meter per 24 hours per one thousandth of an inch of film thickness are considered to be capable of breathing for the purposes of the present invention. In particular aspects of the present inventionThe water vapor transmission rate is at least d around or more than 500 grams per square meter / 2 hours / thousandth of an inch (grams per square meter per 24 hours per 0.001 inches of film thickness). Desirably, the water vapor transmission rate is at least about 2,000 grams per square meter per 24 hours per thousandth of an inch.

Test and Method of Water Steam Transmission To determine the ability to breathe of the compositions of the present invention, the water vapor transmission rates of the poly (ethylene oxide) and clay films were measured in accordance with the standard ASTM standard E96-80 . Circular samples measuring 3 inches in diameter were cut from each of the tested materials as well as a standard control material, CELGARD® 2500 microporous film, available from Hoechst Celanese Corporation. individual samples of test materials and control material were placed through the open top parts of the individual Vapometer rates, each Vapometer cup contained 100 milliliters of distilled water. The bolted flanges of the Vapometer rates were tightened to form a seal along the edges of the cup. The sealed cups were placed in a convection oven set at 100 ° F. The. Relative humidity inside the oven was not specifically controlled.

The cups were first weighed (previous weight) and then placed immediately in the oven. After 24 hours, the cups were removed from the oven and weighed again (later weight). The base water vapor transmission rate of each material was calculated on the weight loss (? W) and reported in grams per square meter per 24 hours. The base rate was normalized to the water vapor transmission rate of the control standard, CELGARD® 2500, by multiplying the base rate by a correction factor (CF): Water Vapor Transmission Rate = Base Rate x Correction Factor The correction factor CF was calculated assuming the water vapor transmission rate of the CELGARD® 2500 micropores film as being 5000 grams per square meter per 24 hours under predetermined established conditions: Correction Factor = 5000 / base rate of CELGARD® 2500 The water vapor transmission rate adjusted to the film thickness was calculated by multiplying the water vapor transmission rate by the film thickness in thousandths of an inch (adjusted water vapor transmission rate) and reported in grams / square meter for 24 hours / 1 thousandth of an inch.

The method and the resulting measurements were normalized against a one-thousand-inch film of CELGARD® 2500 as a control standard. The data was adjusted to the 1-mil film thickness, assuming an inverse proportionality of the water vapor transmission rate to the film thickness. The films comprising a mixture of 70 percent by weight of poly (ethylene oxide) resin POLYOX® N-80 and 30 percent by weight of Claytone APA organically modified clay, ranging in thickness from about 2.2 to about 2.7 thousandths of an inch were measured to have an average water vapor transmission rate of 33.30 grams per square meter per 24 hours per thousandth of an inch.

The dry stress properties of poly (ethylene oxide) resins can also be improved by the addition of the organoclays to the poly (ethylene oxide) resins. The increases in voltage modules in the tensile strength have also been shown. Specifically, higher molecular weight poly (ethylene oxide) resins can be more easily processed with the addition of an organoclay filler to make articles with improved strength and ductility compared to poly (ethylene oxide) resins. filled. In summary, the methods of the present invention can be used to produce polymer compositions with unique morphology and performance and can also be used to increase the stability of polymers that respond to water in highly humid environments, reduce penetration rates of the liquids in the polymers that respond to water, improve the thermal stability of the polymers, increase the strength including the modulus of tension and the bending modulus of the polymers and can further be used to modify the hydrophobic and hydrophilic properties of the various polymers described herein. The present invention allows the development of higher molecular weight and higher ultrasuperior poly (ethylene oxide) compositions with organically modified clay which can be advantageously used to produce stronger, more ductile, and more liquid stable compositions than clay and sugar compositions. poly (ethylene oxide) of low molecular weight.

It should be understood that the examples given above are illustrative embodiments and that the present invention should not be limited by any of the examples or details in the description. Rather, the clauses should be considered broadly within the scope and spirit of the present invention. Particularly, it should be understood that the present invention includes films, multi-layer films and articles in which the claimed compositions are employed.

Claims (57)

R E I V I N D I C A C I O N S

1. A composition of matter comprising an extruded mixture with melting of a polymer responsive to water and more than 5 percent by weight of filler particles modified organically in relation to the sum of the weight of the water sensitive polymer and of the organically modified filler particles , wherein the organically modified filler particles are selected from the group consisting of organically modified clay particles, silicate particles in organically modified layers and mixtures thereof.

2. The composition as claimed in clause 1, characterized in that the polymer that responds to water is a polymer of ethylene oxide.

3. The composition as claimed in clause 1, characterized in that the water-responsive polymer has a melt viscosity which is reduced by the addition of the organically modified clay particles.

4. The composition as claimed in clause 1, characterized in that the water-responsive polymer is a graft copolymer of poly (ethylene oxide) and at least one polar vinyl monomer.

5. The composition as claimed in clause 4, characterized in that the graft copolymer of poly (ethylene oxide) and at least one vinyl monomer is formed by the graft polymerization of from about 0.1 to about 20. percent by weight of polar vinyl monomer or a mixture of polar vinyl monomers in relation to the total weight of the poly (ethylene oxide) and the polar vinyl monomer or mixture of polar vinyl monomers with poly (ethylene oxide).

6. The composition as claimed in clause 5, characterized in that the polar vinyl monomer is selected from the group consisting of 2-hydroxyethyl methacrylate, poly (ethylene glycol) methacrylates and poly (ethylene glycol) ethyl ether methacrylates.

7. The composition as claimed in clause 2, characterized in that the ethylene oxide polymer has a molecular weight in the range of from about 1000 grams per mole to about 8,000,000 grams per mole.

8. The composition as claimed in clause 3, characterized in that the ethylene oxide polymer has a molecular weight in the range of about 200,000 grams per mole to about 4,000,000 grams per mole.

9. The composition as claimed in clause 1, characterized in that the composition comprises more than 5 percent by weight of organically modified clay filler particles in relation to the sum of the weight of the polymer responsive to water and the particles of organically modified clay filler and silicate particles in organically modified layers.

10. The composition as claimed in clause 2, characterized in that the composition comprises more than 5 percent by weight of the organically modified clay filler particles in relation to the sum of the weight of the water-responsive polymer and of the organically modified clay filler particles and the organically modified layered silicate particles.

11. The composition as claimed in clause 10, characterized in that the organically modified clay filler particles comprise organically modified smectite clay filler particles.

12. The composition as claimed in clause 10, characterized in that the organically modified clay filler particles comprise organically modified montmorillonite clay particles or comprise organically modified bentonite clay particles.

13. The composition as claimed in clause 1, characterized in that the organically modified clay filler particles comprise organically modified sodium bentonite clay particles.

14. A disposable film with water discharge comprising the coition as claimed in clause 1.

15. The film as claimed in the clause 14, characterized in that said film has the capacity to breathe.

16. An article that responds to water made by understanding the coition as claimed in clause 1.

17. A coition of matter comprising a molten mixture of a polymer responsive to ethylene oxide water having an average molecular weight in the range of about 100,000 grams per mole to about 8,000,000 grams per mole and more than 5 percent by weight of organically modified clay filler particles, silicate particles in organically modified layers or a mixture thereof in relation to the sum of the weight of the polymer that responds to the water of ethylene oxide, of the organically modified clay particles and of the silicate particles in organically modified layers.

18. The coition as claimed in clause 17, characterized in that the polymer that responds to the water of ethylene oxide is a graft copolymer of ethylene oxide homopolymer and at least one polar vinyl monomer.

19. The coition as claimed in clause 18, characterized in that the polymer which responds to the water of ethylene oxide is formed by the graft polymer of from about 0.1 to about 20 weight percent of the polar vinyl monomer or a mixture of polar vinyl monomers to the total weight of the ethylene oxide homopolymer and of a polar vinyl monomer or mixture of polar vinyl monomers with the ethylene oxide homopolymer.

20. The coition as claimed in clause 19, characterized in that the polar vinyl monomer is selected from the group consisting of 2-hydroxyethyl methacrylate, poly (ethylene glycol) methacrylates and poly (ethylene glycol) ethyl ether methacrylates.

21. The coition as claimed in clause 14, characterized in that the water-responsive polymer of ethylene oxide has an average molecular weight in the range of from about 200,000 grams per mole to about 4,000,000 grams per mole.

22. The coition as claimed in clause 21, characterized in that the polymer that responds to water of ethylene oxide has an average molecular weight in the range of from about 200,000 grams per mole to about 1,000,000 grams per mole.

23. The coition as claimed in clause 22, characterized in that the mixture comprises more than percent of organically modified bentonite clay particles in relation to the sum of the weight of the polymer which corresponds to the water of ethylene oxide, the particles of organically modified arcill and silicate particles in organically modified layers.

24. The coition as claimed in clause 14, characterized in that the organically modified clay particles and the organically modified layered silicate particles essentially consist of particles with an average particle size of no more than about 10 microns.

25. A coition of matter comprising a mixture of a) a polymer that responds to ethylene oxide water having a molecular weight in the range of from about 100,000 grams per mole to about 8,000,000 grams per mole; Y b) from about 5 weight percent to about 45 weight percent organically modified clay particles, organically modified layered silicate particles or from a mixture of organically modified clay and organically modified layered silicate particles based on the sum of the weight of polymer that responds to water, organically modified clay particles and organically modified layered silicate particles.

26. The coition as claimed in clause 25, characterized in that the polymer that responds to the water of ethylene oxide has a molecular weight in the range of from about 200,000 grams per mole to about 2,000,000 grams per mole and the particles of organically modified clay comprise organically modified sodium montmorillonite.

27. A process for making a composition comprising: a) combining a polymer powder responsive to the agu and more than 5 percent by weight of organically modified arcill particles in relation to the sum of the weight of the polymer and the organically modified clay, wherein the organically modified clay is selected from the group q consists of organically modified clays and organically modified silicates and layers; Y b) melt processing the dry mixture of the polymer which responds to the water and the organically modified clay particles under sufficient cutting and melting conditions to produce an extrudable compound with melt with a nanometer dispersion of the clay particles.

28. The process as claimed in clause 27, characterized in that the powder is melted before being combined with the particles of the organically modified clay.

29. The process as claimed in clause 27, characterized in that the powder of the polymer and the particles of an organically modified clay are continuously fed to a melt processing apparatus.

30. The process as claimed in the clause 27, characterized in that the polymer is selected from the group consisting of ethylene oxide and degradable polyesters mixtures thereof.

31. The process as claimed in the clause 28, characterized in that the polymer that responds to water is a graft copolymer of ethylene oxide.

32. The process as claimed in the clause 27, characterized in that the water-responsive polymer is a graft copolymer of poly (ethylene oxide) and at least one polar vinyl monomer.

33. The process as claimed in the clause 32, characterized in that the graft copolymer of poly (ethylene oxide) and at least one polar vinyl monomer is formed by the graft polymerization of from about 0.1 to about 20 weight percent of polar vinyl monomer or a mixture of polar vinyl monomers in relation to the total weight of the poly (ethylene oxide) and the polar vinyl monomer or a mixture of polar vinyl monomers with the poly (ethylene oxide).

34. The process as claimed in the clause 33, characterized in that the polar vinyl monomer is selected from the group consisting of 2-hydroxyethyl methacrylate, poly (ethylene glycol) acrylates and poly (ethylene glycol) ethyl ethacrylates.

35. The process as claimed in the clause 28, characterized in that the ethylene oxide polymer has a molecular weight in the range of about 100,000 grams per mole to about 8,000,000 grams per mole.

36. The process as claimed in the clause 35, characterized in that the ethylene oxide polymer has a molecular weight in the range of about 200,000 grams per mole to about 4,000,000 grams per mole.

37. The process as claimed in the clause 27, characterized in that the composition comprises more than 10 percent by weight of organically modified clay particles in relation to the sum of the weight of the polymer responsive to water and of the organically modified clay particles.

38. The process as claimed in clause 30, characterized in that the composition comprises more than 20 percent by weight of organically modified clay particles in relation to the sum of the weight of the water-responsive polymer and the modified clay particles. organically.

39. The process as claimed in clause 37, characterized in that the organically modified clay filler particles comprise organically modified smectite clay particles.

40. The process as claimed in clause 37, characterized in that the organically modified clay filler particles comprise organically modified montmorillonite clay or organically modified bentonite clay particles.

41. The process as claimed in clause 40, characterized in that the organically modified clay filler particles comprise organically modified sodium bentonite particles.

42. A film made by the process as claimed in clause 27.

43. The film as claimed in the clause 42, characterized in that the film is disposable with water discharge.

44. A multi-layer film comprising a layer made by the process as claimed in clause 27.

45. An article made by the process as claimed in clause 27.

46. A process for making a film comprising or mixing with a melt of a polymer responsive to ethylene oxide water having an average molecular weight within the range of from about 100,000 grams per mole to about 8,000,000 grams per mole and more than 10 percent by weight d filler particles of organically modified clay, organically modified layered silicate particles or a mixture thereof in relation to the sum of the weight of the polymer that responds to the water of ethylene oxide, the organically modified clay particles and the organically modified silicate particles and layers.

47. The process as claimed in clause 46, characterized in that the polymer that responds to the water of ethylene oxide has an average molecular weight in the range of from about 200,000 grams per mole to about 4,000,000 grams per mole.

48. The process as claimed in clause 27, characterized in that the polymer that responds to the water of ethylene oxide has an average molecular weight in the range of from about 200,000 grams per mole to about 1,000,000 grams per mole.

49. The process as claimed in clause 49, characterized in that the molten mixture comprises more than 20 percent by weight of organically modified bentonite clay particles in relation to the sum of the weight of the polymer that responds to the water of ethylene oxide. , the organically modified clay particles and the organically modified layered silicate particles.

50. The process as claimed in clause 46, characterized organically modified clay particles and organically modified layered silicate filler particles essentially consist of particles with average particle size of no more than about 10 microns.

51. The process as claimed in clause 46, characterized in that the polymer that responds to the water of ethylene oxide is a graft copolymer of ethylene oxide homopolymer and at least one polar vinyl monomer.

52. The process as claimed in clause 51, characterized in that the polymer which responds to the water of ethylene oxide is formed by the graft polymerization of from about 0.1 to about 20 weight percent of polar vinyl monomer or a mixture of polar vinyl monomers in relation to the total weight of an ethylene oxide homopolymer and a polar vinyl monomer or mixture of polar vinyl monomers with the ethylene oxide homopolymer.

53. The process as claimed in clause 50, characterized in that the polar vinyl monomer is selected from the group consisting of 2-hydroxyethyl methacrylate, poly (ethylene glycol) methacrylates and poly (ethylene glycol) ethyl ether methacrylates.

54. A process for making a composition comprising: a) creating a dry blend of a poly (ethylene oxide) powder and more than about 10 percent by weight of organically modified clay particles or organically modified layered silicate particles, wherein the average particle size of the particles of organically modified clay or organically modified layered silicate particles is no more than about 10 microns; Y b) Extrude with fusion of the dry mixture.

55. The process as claimed in the clause 54, characterized in that the poly (ethylene oxide) has an average molecular weight of greater than about 1,000,000 grams per mole and the organically modified clay particles comprise organically modified sodium montmorillonite.

56. A manufacturing of a composition that responds to water, the process comprises: supplying a polymer responsive to ethylene oxide water, an organically modified clay, a polar vinyl monomer and an initiator in a twin screw extruder; Y melting and mixing the polymer that responds to the ethylene oxide water, the organically modified clay, the polar vinyl monomer and the initiator to produce a molten mixture of polar graft copolymer of ethylene oxide and the organically modified clay.

57. A process to control the stability of the composition that responds to water in aqueous liquids, the process comprises: supplying a polymer that responds to water and an organically modified clay to a twin screw extruder; and melting and mixing the modified organic clay that responds to the water to produce a molten mixture and the organically modified clay. SUMMARY The present invention describes compositions that respond to water with improved stability to aqueous fluids comprising water or water vapor, processes to increase the stability of water-responsive compositions and processes for making such compositions. The compositions of the present invention comprise a polymer that responds to water and organically modified clay particles. In one embodiment, the polymer that responds to water is a polymer of ethylene oxide, specifically poly (ethylene oxide), and specifically graft copolymers of poly (ethylene oxide). The films of the present invention respond to water and are breathable and are especially useful for personal care applications including disposable diapers, women's pads, pant lining and training underpants. Advantageously, the compositions of the present invention have a reduced melt viscosity and are easier to process with melting in films, fibers and other articles.