WO2013017719A1 - Procédé d'obtention d'une pellicule multicouche à effet de barrière élevé, pellicule, matière et utilisation dans des emballages, dans l'ingénierie tissulaire et dans un biopolyester - Google Patents

Procédé d'obtention d'une pellicule multicouche à effet de barrière élevé, pellicule, matière et utilisation dans des emballages, dans l'ingénierie tissulaire et dans un biopolyester Download PDF

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Publication number
WO2013017719A1
WO2013017719A1 PCT/ES2012/070580 ES2012070580W WO2013017719A1 WO 2013017719 A1 WO2013017719 A1 WO 2013017719A1 ES 2012070580 W ES2012070580 W ES 2012070580W WO 2013017719 A1 WO2013017719 A1 WO 2013017719A1
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Prior art keywords
multilayer film
coating
obtaining
inner layer
barrier
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PCT/ES2012/070580
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English (en)
Spanish (es)
Inventor
José María LAGARÓN CABELLO
Marta MARTÍNEZ SANZ
Amparo LÓPEZ RUBIO
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Consejo Superior De Investigaciones Científicas (Csic)
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Publication of WO2013017719A1 publication Critical patent/WO2013017719A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J7/00—Chemical treatment or coating of shaped articles made of macromolecular substances
    • C08J7/04—Coating
    • C08J7/043—Improving the adhesiveness of the coatings per se, e.g. forming primers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B33/00—Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
    • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
    • B65D65/38—Packaging materials of special type or form
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers

Definitions

  • the present invention relates to a process for obtaining a multilayer film comprising an inner layer of a polar substance with properties of high barrier to gases and / or vapors but sensitive to moisture, which is in turn coated, by techniques of stretched (spinning in English), by one or more outer layers of a hydrophobic substance and / or suitable to act as a moisture barrier.
  • Biodegradable polymers are compounds with great potential that have gained great importance in recent years because they allow reducing the environmental impact associated with the use of petroleum-derived plastic materials.
  • biodegradable thermoplastic biopolyesters such as polylactic acid (PLA), polyhydroxyalkanoates (PHA) and polycaprolactones (PCL) have the advantage of being processed using conventional plastics production techniques and also in some cases, such as those of PLA and PHA, are obtained from renewable sources but have relatively low barrier properties.
  • biodegradable polymeric compounds Although some biodegradable polymeric compounds are currently marketed, they have worse oxygen and / or water barrier properties compared to other substances currently used in packaging, such as polyolefins or polyethylene terephthalate (PET). Many applications, such as food packaging, require a high barrier to oxygen and water vapor, so the improvement of the properties of biopolyesters is necessary for these types of applications. Additionally, the oxygen barrier of non-biodegradable petroleum-derived polyesters such as PET and polyolefins are also worse than those of other polymers such as polyamides or copolymers of ethylene and vinyl alcohol.
  • a strategy for the improvement of the barrier properties of polyolefins, polyesters and biopolyesters consists in the formulation of nanocomposites.
  • cellulose crystals as reinforcing agents in nanocomposites has been greatly extended due to their excellent mechanical and barrier properties, low density and biodegradability. In addition to its application in nanocomposites, it is possible to obtain films from crystalline cellulose that have excellent gas barrier properties under conditions of low relative humidity.
  • TEMPO 2, 2, 6, 6-Tetramethylpiperidine-1-oxyl
  • Bioresources, 2011, 6, 1681-1695 used this technique to deposit ultra-thin layers of lignosulfonates on cellulose fibers and give them a hydrophobic character. In both cases, data relative to the contact angle were provided to demonstrate the hydrophobicization of the cellulose fibers, but data related to the barrier properties of films obtained from the modified fibers were not provided.
  • WO 2010 / 042162A1 describes a multilayer coating to improve the barrier properties of paper or cardboard.
  • This multilayer system can be formed by a first layer that is a barrier for water vapor, one or two layers of a biopolymer that is a barrier, and a last layer that is a barrier for water vapor.
  • the layer that is a barrier to water vapor comprises a derivative of latex and other additives (including cellulose or cellulose derivatives).
  • the biopolymer barrier is a barrier to oxygen.
  • This biopolymer can be starch, chitosan, polysaccharide, protein, gelatin, a biopolyester or mixtures.
  • the coatings are applied by a coating station by the curtain method.
  • WO 96/01736 describes a multilayer coating with the aim of improving the protective barrier against oxygen and moisture.
  • the multilayer system described herein is formed by a polymeric substrate (substrate to be coated), a first oxygen barrier comprising crosslinked polyvinyl alcohol, and a second moisture barrier comprising a cellulosic material, preferably paper, cardboard or fiber vulcanized, deposited on the outside of the protective barrier against oxygen.
  • the multilayer system includes a metallic layer. This document describes the use of lamination techniques and surface corona treatment to apply the successive layers.
  • the strategy proposed in this document is the production of a multilayer film with a high barrier to gases and vapors in which the inner layer comprising polar substances, such as cellulose nanocrystals, coated, by stretching techniques such as electro-stretching ( electrospinning) or blow spinning, by at least one coating of controlled thickness comprising a substance of hydrophobic nature and / or suitable to act as a water barrier, such as polyolefins, polyesters or biopolyesters.
  • polar substances such as cellulose nanocrystals
  • controlled thickness comprising a substance of hydrophobic nature and / or suitable to act as a water barrier, such as polyolefins, polyesters or biopolyesters.
  • the described process allows to improve the adhesion between the inner layer, of hydrophilic character with the layers of the hydrophobic coating in comparison with other methods of obtaining multilayer systems such as the combination of different layers by casting or by thermal compression.
  • the improvement of adhesion between the different layers and the possible nanostructuring of these layers results in a greater degree of improvement of the barrier properties as well as other physical properties including the multilayer film optics.
  • the present invention consists in obtaining new plastic materials that can be partially or completely renewable and biodegradable and that contain films of any moisture sensitive substance, with improved physical properties and in the description of a generic method for coating said films. with hydrophobic substances and / or with water barrier.
  • the present invention provides a process for obtaining a multilayer film comprising a) an inner layer comprising a polar substance and b) at least one coating comprising a hydrophobic substance and / or suitable to act as a water barrier, characterized in that said process it comprises coating the inner layer a) with at least one coating b), using a spinning technique.
  • the stretching technique (spinning in English) used in the process for obtaining the multilayer film object of the invention can be selected from the group consisting of electro-stretch, electro-spray, blow-stretch and blow-spray.
  • the process for obtaining a multilayer film of the present invention can be characterized in that the polar substance comprised in the inner layer a) can be a substance suitable for acting as a barrier to gases and / or vapors.
  • this polar substance is also characterized by being sensitive to moisture.
  • substance suitable for acting as a gas and / or vapor barrier means any substance with excellent gas and / or vapor barrier properties under conditions of low relative humidity.
  • the substance suitable for acting as a barrier to gases and / or vapors in the present invention can be characterized as having low gas permeability, preferably air and oxygen; and / or a low vapor permeability, preferably organic vapors.
  • substance suitable for acting as a gas and / or vapor barrier means any substance with a gas and / or vapor permeability lower than that of polylactic acid (PLA), more preferably equal to or less than that of PET, and even more preferably equal to or less than that of polyamides and EVOH's.
  • PVA polylactic acid
  • “substance suitable for acting as a barrier to gases and / or vapors” means any substance with a permeability to air, oxygen and / or organic vapors less than the permeability that it presents against any of these gases or Vapors the polylactic acid (PLA), more preferably equal to or less than the PET permeability value against these gases or vapors and typically equal to or less than the permeability values of polyamides and EVOH's.
  • PVA polylactic acid
  • the usual value of the permeability of the polylactic acid to oxygen is about 2-10 "18 m 3 m / m 2 s-Pa
  • the PET permeability is about 1
  • the permeability of EVOH ' s is usually less than 1 10 " 19 m 3 m / m 2 s-Pa.
  • the polar substance included in step a) of the present invention can also be characterized as being sensitive to moisture, so that its gas and / or vapor barrier properties, and physical properties in general, can be negatively affected by the presence of moisture, particularly in conditions of relative humidity greater than 40% RH. Specifically, it is considered a moisture-sensitive substance when an increase in oxygen permeability of at least 5 percent, preferably of several orders of magnitude, is observed when the relative humidity increases from 0% RH to 90% RH.
  • the polar substance suitable for acting as a barrier to gases and / or vapors that is sensitive to moisture may be a polysaccharide, a protein, a lipid, polyvinyl alcohol (PVOH), a copolymer of ethylene and vinyl alcohol (EVOH), a polyamide or a mixture of the above.
  • PVOH polyvinyl alcohol
  • EVOH copolymer of ethylene and vinyl alcohol
  • the polar substance comprised in the inner layer a) can be a protein.
  • the inner layer a) may comprise zein, collagen, wheat proteins, soy protein, whey proteins, pea protein, gelatin, keratin, albumins, globulins, caseins or amaranth protein.
  • the polar substance comprised in the inner layer a) can be a lipid.
  • the inner layer a) may comprise fatty acids, acylglycerols, paraffins or waxes.
  • the polar substance comprised in the inner layer a) can be a polysaccharide.
  • the inner layer a) may comprise cellulose, starch, pululane, chitosan, pectin, carrageenans, chitin or maltodextrins.
  • the process of obtaining a multilayer film of the present invention can be characterized in that the polar substance comprised in the inner layer a) can be a cellulose or a cellulose derivative.
  • the inner layer a) can comprise micro-structured or smaller sized cellulose fibers, more preferably it can comprise nanostructured cellulose fibers, even more preferably the inner layer a) can comprise nanocrystals or cellulose nano-needles and still more preferably can comprise nanocrystals or nano-needles of bacterial cellulose.
  • this inner layer a) can be obtained by a vacuum filtration method of a suspension in polar medium of cellulose or by pouring into a plate or impregnating the roller in coating and laminating processes of said solution and subsequent evaporation of the solvent.
  • an acid treatment step of the cellulose can be applied. This acid treatment can be by acid hydrolysis, since it favors the reduction of nanorefore size, which can be followed by neutralization. After several cycles of centrifugation and washing, a suspension of the nanorefolding in polar medium, preferably water, is obtained. The nanostructuring of the product leads to more transparent and resistant films and is therefore a preferred route.
  • the process for obtaining a multilayer film can be characterized in that the inner layer a), any coating b) or both can comprise one or more additives and / or additional nanoadditives.
  • this additive or nanoadditive can be, for example, an adhesive, a plasticizer, a crosslinker, a surfactant, an acid, a base, an emulsifier, an antioxidant, a general processing aid or any mixture thereof or others. that facilitate the formation and / or processing of films.
  • the additive is a plasticizer, being even more preferred that it is polyethylene glycol (PEG) or glycerol.
  • the process for obtaining a multilayer film of the present invention can be characterized in that the inner layer a), any coating b) or both can comprise one or more reinforcing agents of physical properties such as talc, zeolites , clays, nanomaterials in general such as nanosilice, nano-clays, nanotalco, mineral or organic nano-needles and nanomaterials carbonaceous such as fulerenes, nanotubes, carbon nanofibers and graphenes and their derivatives or other reinforcements or nanorefrests with organic or inorganic modification or organic / inorganic hybrid or without modification.
  • the inner layer a), any coating b) or both can comprise one or more reinforcing agents of physical properties such as talc, zeolites , clays, nanomaterials in general such as nanosilice, nano-clays, nanotalco, mineral or organic nano-needles and nanomaterials carbonaceous such as fulerenes, nanotubes, carbon nanofibers and graphenes and their derivative
  • the process for obtaining a multilayer film described in this patent application can be characterized in that the coating substance b) is a hydrophobic substance and is suitable to act as a water barrier.
  • “substance suitable to act as a water barrier” means any substance with a water permeability equal to or less than that of polylactic acid (PLA), that is, equal to or less than 2-10 "14 Kg-m / sm 2 Pa. More preferably the substance suitable to act as a water barrier may have a water permeability equal to or less than that of polyhydroxybutyrate (PHB), ie equal to or less than 1, 5-10 "15 m 3 m / m 2 s-Pa.
  • PHA polylactic acid
  • PHB polyhydroxybutyrate
  • the process for obtaining a multilayer film described in this patent application can be characterized in that the hydrophobic substance and / or suitable to act as a water barrier comprised in any coating b) can be selected within the group of thermoplastic plastics, thermoset plastics and elastomer plastics, more preferably polyolefins, thermosetting resins, polyurethanes, styrenic resins, polyesters, biopolyesters and mixtures thereof.
  • the thermosetting resins can be, for example, epoxy, phenolic or polyester resins.
  • the hydrophobic substance and / or suitable to act as a water barrier may be a thermoplastic biopolyester of renewable and / or biodegradable origin, and more preferably a biopolyester of renewable or preceding biomass origin which increases the renewable and / or biodegradable character of the multilayer formulation.
  • the process for obtaining a multilayer film object of this invention can be characterized in that the hydrophobic substance and / or suitable to act as a water barrier comprised in any coating b) is selected from the group consisting in polylactic acid, a polyhydroxyalkanoate, a polycaprolactone and mixtures thereof.
  • the hydrophobic substance and / or suitable to act as a water barrier is polylactic acid, polyhydroxybutyrate or polyhydroxybutyrate-valerate copolymers.
  • the present invention aims to provide a solution to the problem of the loss of the barrier properties of the substance comprised in the inner layer a) of the multilayer film, allowing to maintain a high barrier to gases and / or vapors even in conditions of high relative humidity. , thanks to the coating of the inner layer, by one or both sides, by a drawing technique, with at least one coating comprising a hydrophobic substance and / or suitable to act as a water barrier.
  • the present invention also serves to reciprocally solve the problem of the low gas barrier and organic vapors of water barrier polymers such as biopolyesters, polyolefins and polyesters. More specifically for multilayers to improve the gas and vapor barrier of biopolyesters.
  • the present invention is characterized by providing a method of obtaining a multilayer film as defined above characterized in that it comprises coating the inner layer a) with at least one coating b), using a drawing technique (spinning in English).
  • this technique can be selected from the group consisting of electro-stretched, electro-sprayed, blow-drawn and blow-sprayed.
  • electro-stretching or electrospraying refers to a technology based on the application of high electric fields to produce electrically charged fluids from viscoelastic polymer solutions, which when dried produce microfibers and nanofibers and nanoparticles, respectively.
  • blow stretch (blow spinning in English) and the spray blown (blow spraying in English), on the other hand use a fluid for the generation of fibers and particles of submicron size. Normally this fluid is a gas at high speed and pressure.
  • the procedure can be performed uniaxially or coaxially when it is desired to obtain a composite coating that has a core type structure -shell "in which a substance constitutes the interior (“ core ”) of the fiber or particle and another forms the walls (" shell ").
  • the coating techniques used in the process of obtaining a multilayer film as described in this patent application allow one or more coatings to be obtained with a thickness determined by modifying different parameters such as, for example, the deposition rate, deposition time and coil winding speed.
  • the process of obtaining a multilayer film as described in this patent application makes it possible to apply a coating b) on one or both sides of the inner layer a). Likewise, when the coating is applied on both sides of the inner layer a), it can be applied sequentially or simultaneously.
  • the additional interest of being able to apply several coatings lies in the need for an outer layer with, for example, printing properties (of special interest in packaging) or structural reinforcement or with adhesive or functional properties; While that the inner layers may be more desirable, for example, that they have heat sealing properties.
  • the process for obtaining a multilayer film object of this invention can be characterized in that it further comprises heating the multilayer film obtained after applying at least one coating b).
  • the heating step may or may not use another prior drying of layer a) by any known method.
  • this additional heating stage the coating is homogenized or cured, thus obtaining a transparent multilayer film or with optimized optical and physical properties.
  • this additional step comprises heating the multilayer film obtained by the process described in this patent application to a temperature above the glass or curing transition temperature, and which more typically will be slightly lower, equal to or greater than the temperature of fusion of the hydrophobic substance and / or suitable to act as a barrier to water comprised in any coating b).
  • the inner layer a) may be manufactured by dissolving or dispersing or suspending the polar substance in a polar or non-polar solvent and subsequently applying a vacuum filtration process or the direct application of the solution and subsequent evaporation of the solvent also known as casting or lamination.
  • the inner layer a) can be manufactured by plastics processing techniques such as, without limitation, extrusion, co-extrusion, extrusion lamination, blow extrusion, applied and curing, vulcanized, calendering, in-situ polymerization followed by processing to obtain sheet, reactive extrusion, blowing, thermoforming, rolling, etc.
  • the method of obtaining a multilayer film described in this patent application may comprise obtaining the inner layer a) by any known method of processing, coating or laminating plastics, paper or cardboard, or also by stretching methods (spinning) including processing methods from gels such as, for example, gel spinning .
  • the method of obtaining a multilayer film as described in this patent application can be characterized in that the technique used to coat the inner layer a) with at least one coating b) is The electro-stretched technique.
  • the electro-stretched coating can be performed at a distance between the capillary and the support between 0.1 and 200 cm, and more preferably between 5 and 50 cm.
  • electro-stretch coating can preferably be performed by applying a voltage between 0.1 and 1000 kV, and more preferably between 5 and 30 kV.
  • the variation of the above parameters allows obtaining, preferably by means of the electro-stretching technique, a coating with a determined morphology.
  • the use of this coating technique allows to modify the uniformity and / or diameter of the nanofibers or electro-stretched nanoparticles obtained.
  • the present invention also provides a multilayer film comprising a) an inner layer comprising a polar substance and b) at least one coating comprising a hydrophobic substance and / or suitable to act as a water barrier, characterized in that said multilayer film is obtained by the procedure described in this patent application.
  • the present invention also provides a multilayer film characterized in that it comprises a) an inner layer comprising a polar substance that is cellulose or a cellulose derivative, and b) at least one coating comprising a hydrophobic substance and / or suitable to act as water barrier that is selected within the group of thermoplastic plastics, thermoset plastics and elastomer plastics, more preferably polyolefins, thermostable resins, polyurethanes, styrenic resins, polyesters, biopolyesters and mixtures thereof.
  • the multilayer film object of this invention can be characterized in that it comprises a) an inner layer comprising a polar substance that can be nanocrystals or nano-needles of bacterial cellulose, and b) at least one coating comprising a hydrophobic substance and / or suitable to act as a water barrier that can be selected from the group consisting of polylactic acid, a polyhydroxyalkanoate, a polycaprolactone and mixtures thereof
  • the multilayer film object of this invention can also be characterized in that the inner layer a), any coating b) or both can comprise at least one additive and / or nanoadditive as defined in this patent application .
  • the multilayer film as defined in this patent application can be characterized in that the inner layer a), any coating b) or both can comprise one or more reinforcing agents of the physical properties of the multilayer as defined in this patent application.
  • the multilayer film defined in this patent application could, for example, be rolled to form a bovine or it could be laminated by any method of lamination to a more complex structure made by the same method or by a more conventional one, to form sheets of interest in oxygen and moisture barrier applications and that could be molded or postprocessed, for example by thermoforming, to obtain a final material.
  • the present invention also protects a material characterized in that it comprises the multilayer film as defined in this patent application.
  • said material can comprise a laminated structure with the multilayer film object of this invention covered with paper and / or cardboard, and can be flexible, semi-flexible or rigid.
  • the present invention also protects the use of the multilayer film defined in this patent application or the material comprising said multilayer film as defined above, for packaging or coating a product sensitive to oxidation and / or moisture.
  • a product sensitive to oxidation and / or moisture Preferably to package a food, pharmaceutical or electronic product; as well as for coating, containing or supporting an electronic product or, when the multilayer film comprises substances suitable for such uses, for coating a food or pharmaceutical product.
  • the present invention also protects the use of the multilayer film defined in this patent application, or of the material comprising said multilayer film as defined above, in tissue engineering. Another aspect of the present invention relates to the use of the multilayer film defined in this patent application, or of the material comprising said multilayer film as defined above, to increase the gas and vapor barrier of a biopolyester.
  • the areas of interest can be food containers for both flexible, semi-flexible and rigid, pharmaceutical, electronic (e.g. printed flexible electronics) or in tissue engineering applications or in coatings of materials such as food.
  • Fig. 1 It shows an image of Scanning Electron Microscopy (SEM) of the fracture section obtained after treating the bacterial cellulose nanocrystals layer with liquid nitrogen (cryofracture).
  • FIG. 2 Photographs of the nanocrystalline layers of bacterial cellulose (a) and their multilayers with PLA fibers (b) and PHBV12 fibers (c). These photographs show how the good transparency of the initial inner layer is maintained after coating it by the procedures described.
  • Fig. 3 It shows an image of Scanning Electron Microscopy (SEM) of the cryofracture section corresponding to the nanocrystalline layer of bacterial cellulose coated with PLA fibers.
  • the invention will now be illustrated by tests carried out by the inventors, which show the specificity and effectiveness of the Process of the invention for obtaining multilayer films that have excellent barrier properties thanks to the polar substance of the inner layer, while the outer coatings give the films a hydrophobic character.
  • the inner layer comprises nanocrystals of bacterial cellulose.
  • Example 1 Obtainment of multilayer films of bacterial cellulose nanocrystals coated with polylactic acid electro-stretched fibers
  • a specific application of the invention consists in obtaining films from nanocrystals of bacterial cellulose and coating them with electro-stretched polylactic acid (PLA) fibers.
  • PLA polylactic acid
  • the nanocrystals used to produce the film are extracted from bacterial cellulose by a treatment with sulfuric acid.
  • the bacterial cellulose in an amount such that the cellulose / acid ratio is 7g / l, is immersed in sulfuric acid of 301 ml / l concentration, applying a temperature of 50 ° C with continuous stirring.
  • the treatment is applied until a homogeneous solution is obtained, the time needed to obtain the nanocrystals of 3 days.
  • the solution obtained is subjected to four centrifugation cycles at 12,500 rpm, 15 ° C and 20 minutes, finally obtaining a precipitate with a pH close to 2.
  • Said precipitate is redispersed in water and neutralized with NaOH until a pH is reached. close to 7.
  • the solution is subjected to a new centrifugation cycle, obtaining the nanocrystals as a partially hydrated precipitate.
  • the acid treatment conditions previously described allow obtaining nanocrystal structures with diameters smaller than 100 nm.
  • an aqueous suspension of the cellulose nanocrystals in water is prepared, which will be used to obtain the films.
  • the Cellulose nanocrystals are added in 50 ml of water in a concentration of 0.5% w / v and dispersed by using an Ultra-Turrax homogenizer and subsequently, by applying ultrasound. Additionally, suspensions containing 20% by weight with respect to the cellulose of a plasticizer such as polyethylene glycol (PEG) can be prepared. These suspensions are subjected to a vacuum filtration process to remove water. In this process, the suspension is filtered through a Teflon filter (PTFE) with a pore size of 0.2 ⁇ and allowed to dry for several hours at room temperature.
  • PTFE Teflon filter
  • the cellulose layer obtained has a highly compact structure of nanocrystals as shown in Figure 1.
  • the oxygen permeability of this layer is approximately 7- 10 "22 m 3 rn / m 2 s Pa under conditions of 0% RH, while for 80% RH the permeability increases dramatically up to 6- 10 " 18 m 3 m / m 2 s Pa or even higher values, making the determination of permeability very difficult due to its high values.
  • the cellulose nanocnstal layer After obtaining the cellulose nanocnstal layer, it is coated with electro-stretched PLA fibers. The coating of the cellulose layer is carried out by the electro-stretching technique with a horizontal configuration.
  • a solution of the polymer in 1, 1, 1, 3,3,3-Hexafluoro-2-propanol (HFP) is prepared in a concentration of 8% w / v.
  • the solution is introduced into 5ml syringes connected through teflon tubes to a stainless steel needle with a diameter of 0.9 mm. The needle is connected to an electrode that in turn is connected to a 0-30 kV power supply.
  • a voltage between 10-12 kV is applied and the solution is pumped through said needle with a flow of 0.6 ml / h.
  • the counter electrode is connected to a plate (collector) in which the cellulose nanocrystal layer is fixed, the distance between needle and plate being about 6 cm.
  • the process is carried out at room temperature. In this way, a layer of cellulose nanoctals coated with 40-50% by weight of electro-stretched PLA fibers is obtained. After applying the coating, the film has an opaque and white appearance.
  • a heating step is applied at a temperature of 160 ° C to homogenize the PLA by softening or melting.
  • the film Prior to this heating stage, the film has been subjected to a drying stage at 60 ° C for one day. This results in a multilayer film formed by a layer of nanocrystals of bacterial cellulose coated on both sides with a coating of PLA fibers with a thickness between 5 and 8 micrometers, as shown in Figure 3.
  • the previously described process for obtaining multilayer films allows to reduce the oxygen permeability of the cellulose nanocrystal layers at high humidity by at least 97% and the water permeability by 66%, as shown in the Table one .
  • oxygen permeability is reduced by at least 74% at high humidity, while water permeability is reduced by 69%.
  • the multilayer film does not impair the transparency of the cellulose layer, as shown in Figure 2B.
  • Table 1 Oxygen permeability measured under 80% RH conditions and water permeability measured under 75% RH conditions.
  • Example 2 Obtaining multilayer films of bacterial cellulose nanocrystals coated with electro-stretched polyhydroxybutyrate-valerate fibers
  • a specific application of the invention consists in obtaining films from nanocrystals of bacterial cellulose and coating them with electro-stretched polyhydroxybutyrate-valerate fibers with a 12% valerate content (PHBV12).
  • the nanocrystals used to produce the inner layer of the multilayer film are extracted from bacterial cellulose by the treatment explained in the previous example.
  • the layers of bacterial cellulose nanocrystals are obtained by applying the same vacuum filtration procedure discussed in the previous example.
  • a PHBV12 fiber coating is applied on the bacterial cellulose nanocrystal layer by means of the electro-stretching technique with a horizontal configuration.
  • a solution of the polymer in 1, 1, 1, 3,3,3-Hexafluoro-2-propanol (HFP) is prepared in a concentration of 6% w / v.
  • the solution is introduced into 5ml syringes connected through teflon tubes to a stainless steel needle with a diameter of 0.9 mm.
  • the needle connects to an electrode that in turn it is connected to a 0-30 kV power supply.
  • a voltage between 10-12 kV is applied and the solution is pumped through said needle with a flow of 0.6 ml / h.
  • the counter electrode is connected to a plate (collector) in which the cellulose nanocrystal layer is fixed, the distance between needle and plate being about 6 cm.
  • the process is carried out at room temperature. In this way, a layer of cellulose nanocrystals coated with 40-50% by weight of electro-stretched fibers of PHBV12 is obtained.
  • the multilayer film After applying the coating, the multilayer film has an opaque and white appearance.
  • a heating step at a temperature of 160 ° C is applied to homogenize the PHBV12.
  • the film Prior to this heating stage, the film has been subjected to a drying stage at 60 ° C for one day. In this way, a multilayer film formed by a layer of nanocrystals of bacterial cellulose coated on both sides with a PHBV12 fiber coating with a thickness between 3 and 6 micrometers is obtained.
  • the multilayer films obtained by the previously described procedure allow a high reduction of the permeability to oxygen at high humidity as it is deduced from Table 2.
  • the film also maintains the transparency of the internal starting layer.
  • Table 2 Oxygen permeability measured under conditions of 80% RH.

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  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
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Abstract

L'invention concerne un procédé d'obtention d'une pellicule multicouche comprenant: a) une couche intérieure renfermant une substance polaire, et b) au moins un revêtement renfermant une substance hydrophobe et/ou appropriée pour agir comme barrière à l'eau. L'invention se caractérise en ce que ledit procédé consiste à revêtir la couche intérieure a) avec au moins un revêtement b), à l'aide d'une technique de filage. De préférence, la substance polaire de la couche intérieure a) est une substance appropriée pour agir comme barrière aux gaz et/ou aux vapeurs, et présente une sensibilité à l'humidité. L'invention concerne également la pellicule multicouche décrite, une matière la comprenant et diverses utilisations de cette pellicule multicouche ou de cette matière.
PCT/ES2012/070580 2011-08-01 2012-07-27 Procédé d'obtention d'une pellicule multicouche à effet de barrière élevé, pellicule, matière et utilisation dans des emballages, dans l'ingénierie tissulaire et dans un biopolyester WO2013017719A1 (fr)

Applications Claiming Priority (2)

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ES201131336A ES2401616B1 (es) 2011-08-01 2011-08-01 Procedimiento de obtención de una película multicapa con alta barrera
ESP201131336 2011-08-01

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WO2013017719A1 true WO2013017719A1 (fr) 2013-02-07

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ES (1) ES2401616B1 (fr)
WO (1) WO2013017719A1 (fr)

Cited By (1)

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ES2604054A1 (es) * 2015-09-02 2017-03-02 José Antonio PEDRO MONZONIS Procedimiento para el tratamiento de herramientas susceptibles de ser expuestas a partículas radiactivas y equipo para la puesta en práctica del mismo

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ES2770151A1 (es) * 2018-12-31 2020-06-30 Nastepur S L Envase biodegradable, su procedimiento de obtencion y su uso para contacto, transporte y/o almacenaje de productos perecederos
EP4314312A1 (fr) * 2021-03-26 2024-02-07 Cellugy ApS Suspensions de cellulose bactérienne

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JPH1025638A (ja) * 1996-07-10 1998-01-27 Asahi Chem Ind Co Ltd 多層構造糸条
CN101381904A (zh) * 2008-09-04 2009-03-11 东华大学 一种吸湿性共混纤维的制备方法
WO2009065983A1 (fr) * 2007-11-23 2009-05-28 Nanobiomatter, S.L. Procédé de fabrication d'emballages passifs à propriétés améliorées, actives, intelligentes et bioactives par incorporation de polymères obtenus au moyen de techniques d'électro-étirage
KR20120021734A (ko) * 2010-08-16 2012-03-09 주식회사 아모메디 플라즈마 처리에 의한 친수성 웨스턴 블롯용 멤브레인 및 그 제조방법

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Publication number Priority date Publication date Assignee Title
JPH1025638A (ja) * 1996-07-10 1998-01-27 Asahi Chem Ind Co Ltd 多層構造糸条
WO2009065983A1 (fr) * 2007-11-23 2009-05-28 Nanobiomatter, S.L. Procédé de fabrication d'emballages passifs à propriétés améliorées, actives, intelligentes et bioactives par incorporation de polymères obtenus au moyen de techniques d'électro-étirage
CN101381904A (zh) * 2008-09-04 2009-03-11 东华大学 一种吸湿性共混纤维的制备方法
KR20120021734A (ko) * 2010-08-16 2012-03-09 주식회사 아모메디 플라즈마 처리에 의한 친수성 웨스턴 블롯용 멤브레인 및 그 제조방법

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2604054A1 (es) * 2015-09-02 2017-03-02 José Antonio PEDRO MONZONIS Procedimiento para el tratamiento de herramientas susceptibles de ser expuestas a partículas radiactivas y equipo para la puesta en práctica del mismo
WO2017037314A1 (fr) * 2015-09-02 2017-03-09 Pedro Monzonis José Antonio Procédé pour le traitement d'outils susceptibles d'être exposés à des particules radioactives et équipement pour la mise en pratique dudit procédé

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ES2401616A2 (es) 2013-04-23
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