Antimicrobial composite material (Machine-translation by Google Translate, not legally binding)

专利摘要:
Antimicrobial composite material. Activated and ground sodium hexametaphosphate frit particles and antimicrobial composite material comprising said activated and ground sodium hexametaphosphate frit particles embedded in a thermoplastic polymer such as low density polyethylene (LDPE). The invention also includes the process for obtaining the composite material of the invention and a method of thermal activation of a sodium hexametaphosphate salt to give rise to activated and ground sodium hexametaphosphate frit particles. The antimicrobial material of the invention is preferably used in the food industry. (Machine-translation by Google Translate, not legally binding)
公开号:ES2734497A1
申请号:ES201830547
申请日:2018-06-05
公开日:2019-12-10
发明作者:Lozano José Francisco Fernandez；Reinosa Julián Jimenez；Arroyo Alberto Moure；Medina José Javier Menendez
申请人:Encapsulae S L；Consejo Superior de Investigaciones Cientificas CSIC；
IPC主号:

专利说明:

[0001] Antimicrobial composite material
[0002]
[0003] Field of the Invention
[0004]
[0005] The present invention is related to the area of antimicrobial materials. More specifically the present invention is related to the area of antimicrobial composites.
[0006]
[0007] Background of the invention
[0008]
[0009] At present, microbial infections still account for a quarter of the deaths produced worldwide. This situation is aggravated if the increase in antibiotic resistance by microorganisms is taken into account. Many substances can be described as antimicrobials for example disinfectants, antibiotics and, of course, antimicrobial agents. However, many of these compounds may present toxicity or be harmful to humans.
[0010]
[0011] The Kenawy et al. [AND. Kenawy, SD Worley and R. Broughton. The Chemistry and Applications of Antimicrobial Polymers: A State-of-the-Art Review. Biomacmmolecules, 85, 1359-1384 (2007)] proposes the use of polymers to improve the efficacy of some antimicrobial agents. In particular, Kenawy et al. propose the introduction of antimicrobial functional groups in polymeric molecules giving rise to antimicrobial polymers. In this way the residual toxicity of said functional groups is reduced and their efficiency, selectivity and their useful life are increased. However, attempts to reduce the toxicity of these antimicrobial agents are far from guaranteeing their use in areas as susceptible as food and medical applications among others.
[0012]
[0013] In the food industry, sodium hexametaphosphate is used as a synthetic stabilizer and acidity corrector. It can be applied in meat and fish to improve its water retention capacity and to prevent the oxidation of fats. In emulsions, it increases viscosity and prevents product precipitation by improving the texture and color of food products. For these reasons, it is usually found in processed meats, chewing gum, sugary drinks, precooked and dairy foods, such as lactose-free milk or various types of cheeses, sauces, fruit jelly, frozen desserts, salad dressing, breakfast cereal, ice cream , beer and bottled drinks between others. For example, CN104542895A describes a water soluble polymeric composite for use as a pork preservative. Said polymeric material includes in its composition a commercial sodium hexametaphosphate salt in a proportion between approximately 15-25% by weight to preserve moisture in the meat. Furthermore, by adding specific natural bactericidal agents such as grapefruit skin polysaccharides, a bactericidal effect is generated in the polymeric material described herein. The polymeric material described in CN104542895A is used as a preservative although due to its water-soluble nature, it would be limited to certain applications and, for example, could not be used for food packaging.
[0014]
[0015] In the scientific literature, the indirect nature of phosphate salts as preservatives or inhibitors of the growth of microorganisms has been described. Tompkin's document [RB Tompkin, Indirect antimicmbial effects in foods: phosphates. Journal of Food Society 6 (1983) 13-17] describes the inhibitory mechanism produced by said phosphate salts due to interference with the metabolism of the divalent cations of microorganisms by producing a deficiency, mainly of magnesium, that inhibits cell division and It causes the loss of the cell wall. The document by Akhtar et al. [S. Akhtar, D. Paredes-Sabja, MR Sarker. Inhibitory effects of polyphosphates on Clostridium perfringens growth, sporulation and spore outgrowth. Food Microbiology 25.6 (2008) 802-808] describes bacterial growth inhibition processes for a relevant number of bacteria for concentrations of polyphosphate salts commonly used in the food industry, that is, 0.2-0.8 % in weigh. However, the efficacy of such polyphosphate salts as antimicrobial agents described in the state of the art is very limited and does not allow their use in a large number of bacteria. Another difficulty in using polyphosphate salts as antimicrobial agents is their slow dissolution in aqueous media. In addition, so far, a simultaneous antimicrobial effect of polyphosphate salts in gram-positive and gram-negative bacteria has not been demonstrated.
[0016]
[0017] Therefore, there is a need for new composite materials that show antimicrobial activity against different bacteria, high efficiency and that do not present the inconveniences related to toxicity phenomena.
[0018]
[0019] Brief Description of the Invention
[0020] The authors of the present invention have developed a composite material comprising activated and ground sodium hexametaphosphate frit particles and a polymer matrix with antimicrobial properties.
[0021]
[0022] Therefore, a first aspect of the invention relates to a composite material comprising:
[0023] a) activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation procedure comprising the steps of: i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0024] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0025] iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles; Y
[0026] b) a polymer matrix;
[0027] wherein said activated and ground sodium hexametaphosphate frit particles are embedded in said polymer matrix.
[0028]
[0029] A second aspect of the present invention is directed to a use of the composite material of the present invention as an antimicrobial agent; preferably as an antibacterial agent; more preferably as an antibacterial agent against gram positive bacteria and gram negative bacteria.
[0030]
[0031] A third inventive aspect is directed to a process for obtaining the composite material of the present invention comprising the steps of
[0032] i) provide
[0033] a) activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation process comprising the steps of:
[0034] i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0035] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0036] iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles; Y
[0037] b) a polymer matrix; Y
[0038] ii) embedding said activated and ground sodium hexametaphosphate frit particles in said polymer matrix.
[0039]
[0040] An additional inventive aspect is directed to activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation process comprising the steps of:
[0041] i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0042] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0043] iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles.
[0044]
[0045] Finally, a last inventive aspect of the present invention is directed to a method of thermal activation of a sodium hexametaphosphate salt to give rise to the activated and ground sodium hexametaphosphate frit particles as defined above comprising the stages of
[0046] i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0047] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0048] iii) grind the sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles.
[0049] Figures
[0050] Figure 1: Raman spectra obtained for (a) the activated and ground sodium hexametaphosphate frit particles (solid line) and for (b) the ground sodium hexametaphosphate salt (discontinuous line).
[0051]
[0052] Figure 2: Enlargement of Raman spectra obtained for (a) the activated and ground sodium hexametaphosphate frit particles (solid line) and for (b) the ground sodium hexametaphosphate salt (dashed line).
[0053]
[0054] Figure 3: Thermogravimetric curves corresponding to the sodium hexametaphosphate salt (solid line Figure 3a), the milled sodium hexametaphosphate salt (dashed line Figure 3a), the activated sodium hexametaphosphate frit particles (continuous line Figure 3b) and the activated and ground sodium hexametaphosphate frit particles (dashed line Figure 3b).
[0055]
[0056] Figure 4: Conductivity values (mS / cm) versus time for milled sodium hexametaphosphate salt (square symbol) and for activated and milled sodium hexametaphosphate frit particles (circular symbol).
[0057]
[0058] Figure 5: Image of confocal microscopy of a particle of activated and ground sodium hexametaphosphate frit (1) embedded in low density polyethylene (2).
[0059]
[0060] Figure 6: Conductivity values (^ S / cm) versus time for activated and ground sodium hexametaphosphate frit particles embedded in low density polyethylene.
[0061]
[0062] Figure 7: (a) Image of confocal optical microscopy that a particle of activated and ground sodium hexametaphosphate frit (4) embedded in low density polyethylene (2) together with a drop of water (3) after immersion of the compound in water for 15 minutes and subsequent drying at 60 ° C for 1 hour. (b) Representative Raman spectra corresponding to the image of the LDPE polymer matrix (2), water drop (3) stabilized on the surface of the compound in the vicinity of a particle of activated and ground sodium hexametaphosphate frit (4) .
[0063]
[0064] Figure 8: Micrographs at different magnifications (a) and (b), of the surface of the polymeric film formed by the composite material comprising activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix according to example 6. Said film was exposed to ambient humidity for 60 days and dried in an oven at 60 ° C for 1 hour.
[0065]
[0066] Detailed description of the invention
[0067]
[0068] Unless stated otherwise, all the scientific terms used here have the meaning that is commonly understood by the person skilled in the art to which this description is directed. In the present invention, the singular forms include the plural forms unless otherwise indicated.
[0069]
[0070] Composite and activated and ground sodium hexametaphosphate frit particles
[0071]
[0072] The main aspect of the present invention is to provide a composite material comprising:
[0073] a) activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation procedure comprising the steps of: i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0074] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0075] iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles; Y
[0076] b) a polymer matrix;
[0077] wherein said activated and ground sodium hexametaphosphate frit particles are embedded in said polymer matrix.
[0078]
[0079] The term "composite material" refers to combinations of at least two types of materials to achieve the combination of properties that is not possible to obtain in the original materials. Generally, the composite materials have a continuous matrix and a discrete load The composite material of the present invention comprises a continuous matrix which is preferably a hydrophobic or hydrophobic polymer matrix, and a discrete charge comprising activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation procedure as described above. previously mentioned.
[0080] The authors of the present invention have surprisingly found an antimicrobial behavior in the composite material of the present invention.
[0081]
[0082] An inventive aspect of the present invention is directed to activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation process comprising the steps of:
[0083] i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0084] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0085] iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles.
[0086]
[0087] In the present invention, the activated and ground sodium hexametaphosphate frit particles are obtainable by a thermal activation process comprising step (i) of heating a sodium hexametaphosphate salt until melted so that a molten salt is obtained of sodium hexametaphosphate.
[0088]
[0089] In the context of the present invention, the term "sodium hexametaphosphate" refers to a chemical compound formed by a mixture of linear polyphosphate polymers with general formula (NaPO3) n. Said chemical compound may also be referred to as "Graham salt", Calgon S, vitreous sodium, sodium tetraphosphate, sodium metaphosphate, sodium polymetaphosphate, sodium polyphosphate, hexasodium metaphosphate, hexasodium salt, metaphosphoric acid and the like
[0090]
[0091] In the context of the present invention, the term "sodium hexametaphosphate salt" refers to a sodium hexametaphosphate salt generated by heating sodium dihydrogen phosphate (NaH2PO4), dihydrogen disodium pyrophosphate (Na2H2P2O7) or NaH (NH4) PO4.4H2O or other salt or sodium salts to its melting point and then, when cooled rapidly ( quenching).
[0092]
[0093] In the context of the present invention the term "fried" refers to an inorganic compound that has no long-term crystalline order or vitreous or liquid compound. subcooled The frit is in the form of irregular fragments, scales or granules obtained from the melting at elevated temperatures of a starting material, which has the same chemical composition as the initial material, and rapid cooling.
[0094]
[0095] In the context of the present invention, the expression "activated and ground sodium hexametaphosphate frit particles" refers to particles obtainable from a sodium hexametaphosphate salt by a thermal activation process comprising the steps of:
[0096] i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0097] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0098] iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles.
[0099]
[0100] In the context of the present invention, the term "thermal activation process" is a process not related to a chemical reaction such as the synthesis of a material other than the precursor, but rather a procedure related to a modification of the characteristics and / or properties of the material that are acquired through a process that requires a heat treatment as defined in the present invention carried out with the means known to the person skilled in the art. In the present invention said process further comprises a milling step that can be performed by methods known to those skilled in the art.
[0101]
[0102] In the context of the present invention, the term "heating a sodium hexametaphosphate salt until melted" is related to a sufficient heating so that the sodium hexametaphosphate salt changes from physical state so that it passes from a solid state to a solid state. liquid state by the action of heat. Said heating can be produced by any means known to the person skilled in the art; for example, by heating in an oven.
[0103]
[0104] In a particular embodiment, step (i) of the activation procedure of the activated sodium hexametaphosphate frit particles of the present invention comprises heating said sodium hexametaphosphate salt of step (i) at a temperature between 630 ° C and 1000 ° C; preferably between 650 and 900 ° C; more preferably between 660 and 800 ° C.
[0105]
[0106] In a particular embodiment, step (i) of the activation procedure of the activated sodium hexametaphosphate frit particles of the present invention comprises heating said sodium hexametaphosphate salt of step (i) for at least 30 minutes; preferably for at least 1 hour; more preferably for a period of time between 1 hour and 5 hours.
[0107]
[0108] In a particular embodiment, step (i) of the activation procedure of the activated sodium hexametaphosphate frit particles of the present invention comprises heating for at least 30 minutes at a temperature between 650 and 900 ° C.
[0109]
[0110] In the present invention, the activated and ground sodium hexametaphosphate frit particles are obtainable by a thermal activation process comprising step (ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in a dry medium to obtain activated sodium hexametaphosphate frit particles.
[0111]
[0112] In a particular embodiment, step (ii) of the activation procedure of the activated sodium hexametaphosphate frit particles of the present invention comprises pouring said molten salt of sodium hexametaphosphate obtained in step (i) onto a metal plate; preferably on a bronze or stainless steel plate; preferably bronze.
[0113]
[0114] In a particular embodiment, step (ii) of the activation process of the activated sodium hexametaphosphate frit particles of the present invention comprises pouring said molten salt of sodium hexametaphosphate obtained in step (i) onto a fritter; preferably a dry fritter.
[0115]
[0116] In the context of the present invention, the term "dry fritter" is related to a frying equipment of those commonly known to the person skilled in the art, preferably, to a frying mill laminator to which a device is applied to have a final temperature of the controlled and stable frit particles.
[0117] In a particular embodiment, step (ii) of the activation procedure of the activated sodium hexametaphosphate frit particles of the present invention comprises pouring said molten salt of sodium hexametaphosphate obtained in step (i) onto a metal plate; wherein said metal plate is at a temperature between 15 and 50 ° C: preferably at room temperature.
[0118]
[0119] In a particular embodiment, step (ii) of the activation procedure of the activated sodium hexametaphosphate frit particles of the present invention comprises pouring said molten salt of sodium hexametaphosphate obtained in step (i) onto a metal plate; wherein said metal plate is cooled by means of a water coil or by means of an air current.
[0120]
[0121] In the context of the present invention, the term "room temperature" refers to a temperature between 15 and 35 ° C.
[0122]
[0123] In the context of the present invention, the expression "suddenly" referred to the cooling of said molten salt of sodium hexametaphosphate obtained in step (i), refers to a reduction in the temperature of said molten salt of sodium hexametaphosphate from its melt temperature to a temperature below 500 ° C in less than one minute, that is, with a cooling rate greater than 200 ° C / min.
[0124]
[0125] In a particular embodiment, step (ii) of the activation procedure of the activated sodium hexametaphosphate frit particles of the present invention comprises a cooling rate greater than 200 ° C / min, preferably greater than 300 ° C / min .
[0126]
[0127] In the context of the present invention, the expression "in dry medium" referring to the cooling of said molten salt of sodium hexametaphosphate obtained in step (i), refers to rapidly cooling said molten salt without the aid of a liquid medium, such as water, using the means commonly known to the person skilled in the art.
[0128]
[0129] Additionally, the authors of the present invention have found that surprisingly, the thermally activated sodium hexametaphosphate frit particles of the present invention have a greater capacity and dissolution rate than the sodium hexametaphosphate salt.
[0130] Without being linked to a particular theory, the authors of the present invention have found that by using a cooling in dry medium, costs are saved in the conditioning of the frit particles of the present invention associated with the formation of joints between said particles during drying. In addition, an increase in yield expressed in kilos per hour of frit produced has been observed by dry cooling.
[0131]
[0132] In a particular embodiment, the activated sodium hexametaphosphate frit particles are formed by a vitreous material.
[0133]
[0134] In a more particular embodiment, the activated and ground sodium hexametaphosphate frit particles are formed of a vitreous material.
[0135]
[0136] In the context of the present invention, the term "vitreous material" refers to an inorganic material that has an atomic arrangement that does not show an ordered structure of long range unlike in the crystalline state.
[0137]
[0138] In a particular embodiment, the activated and ground sodium hexametaphosphate frit particles possess a Raman spectrum with a redshift in a manner corresponding to the symmetrical stretching of the terminal oxygen in the PO2 units formed by chains of tetrahedra type Q2 that the salt of sodium hexametaphosphate.
[0139]
[0140] In a particular embodiment, the activated and ground sodium hexametaphosphate frit particles comprise a mass percentage of water absorbed in its composition greater than 2.5%, preferably greater than 5%, more preferably greater than 10%.
[0141]
[0142] In a particular embodiment, the activated sodium hexametaphosphate frit particles are hydrophilic.
[0143]
[0144] In a more particular embodiment, the activated and ground sodium hexametaphosphate frit particles are hydrophilic.
[0145]
[0146] In a particular embodiment, the activated sodium hexametaphosphate frit particles have a higher dissolution rate than the sodium hexametaphosphate salt.
[0147] In a more particular embodiment, the activated and ground sodium hexametaphosphate frit particles have a higher dissolution rate than the sodium hexametaphosphate salt.
[0148]
[0149] In a particular embodiment, the activated sodium hexametaphosphate frit particles are irregularly shaped; preferably it is in the form of a granule or scale; more preferably flake.
[0150]
[0151] In a more particular embodiment, the activated and ground sodium hexametaphosphate frit particles are irregularly shaped; preferably they are in the form of granule or scale; more preferably flake.
[0152]
[0153] In a particular embodiment, the activated and ground sodium hexametaphosphate frit particles are transparent.
[0154]
[0155] In a particular embodiment, the activated and ground sodium hexametaphosphate frit particles have a refractive index value between 1.3 and 1.7; preferably between 1.4 and 1.6.
[0156]
[0157] In the context of the present invention the expression "particle size" refers to the activated sodium hexametaphosphate frit particles of step (ii) or the activated and ground sodium hexametaphosphate frit particles of step (iii), refers to the particle size distribution or granulometric curve that is determined statistically and is characterized by parameters d50 and d90. In the context of the present invention the expressions "parameter d50" and "parameter d90" refer to the equivalent size that corresponds to 50% and 90% respectively, of the cumulative distribution of particle size or granulometric curve.The equivalent size refers to the diameter of the sphere that has the same specific area as the specified particle population.
[0158]
[0159] In a particular embodiment, the activated sodium hexametaphosphate frit particles of the present invention have a d90 parameter of less than 5 cm, preferably less than 2 cm, more preferably less than 1 cm.
[0160]
[0161] In a particular embodiment, the activated and ground sodium hexametaphosphate frit particles of the present invention have a d90 parameter of less than 100 microns, preferably less than 50 microns, more preferably less than 20 microns; even more preferably less than 10 microns.
[0162]
[0163] In a particular embodiment, the activated and ground sodium hexametaphosphate frit particles of the present invention are micrometric particles; preferably with an average diameter between 0.5 and 100 microns, more preferably between 1 and 50 microns, even more preferably between 1 and 10 microns.
[0164]
[0165] In a preferred embodiment, the activated sodium hexametaphosphate frit particles of the present invention have less than 50% of their particles with at least one of their dimensions less than 100 nm.
[0166]
[0167] In the present invention, the activated and ground sodium hexametaphosphate frit particles are obtainable by a thermal activation process comprising step (iii) milling the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain Sodium hexametaphosphate frit particles activated and ground.
[0168]
[0169] In the context of the present invention, the term "activated and ground sodium hexametaphosphate frit particles" refers to activated sodium hexametaphosphate frit particles that have undergone a milling and / or crushing process or a combination of grinding or crushing to select a certain range of sizes. Said milling and / or crushing process can be selected from any of those known to a person skilled in the art. Non-limiting examples of such milling processes are those performed by mills such as planetary or jaw mills. Non-limiting examples of mills suitable for milling the present invention are ring mills such as tungsten carbide ring mills, air jet mills ( jet milli) or ball mills or microballs, among others.
[0170]
[0171] In a particular embodiment, the milling of step (iii) comprises at least one dry milling in a planetary mill; preferably at least one dry milling; preferably a dry milling in a planetary mill; more preferably in a planetary mill with alumina or zirconia balls.
[0172] In a particular embodiment, the milling of step (iii) comprises at least one dry milling; preferably a dry milling in a jaw mill; preferably at least one dry milling in a jaw mill with tungsten rings.
[0173]
[0174] In a particular embodiment, the milling of step (iii) comprises at least one dry milling; wherein said dry milling comprises several grinding stages.
[0175]
[0176] In a particular embodiment, the activated and ground sodium hexametaphosphate frit particles are a white or transparent powdery material; preferably transparent.
[0177]
[0178] In the context of the present invention, the parameters defining the size distribution of activated sodium hexametaphosphate frit particles or activated and ground sodium hexametaphosphate frit particles can be measured by methods known to the person skilled in the art. the matter, for example, via dry using a laser analyzer of particle size distribution as a MASTERSIZER 2000 of the signature MALVERN. Parameter d90 is determined statistically from the equivalent size corresponding to 90% by weight of the population of the cumulative distribution of the particle size distribution or granulometric curve. In turn, parameter d50 is determined statistically from the equivalent size corresponding to 50% by weight of the population of the cumulative distribution of the particle size distribution or particle size curve. In turn, in the context of the present invention, the "equivalent size" refers to the diameter of the sphere having the same specific area as the specified particle population.
[0179]
[0180] In the context of the present invention, the term "embedding" relative to activated and ground sodium hexametaphosphate frit particles refers to introducing or incorporating said particles into a polymer matrix by processes of the polymer industry known to a person skilled in the art. In the context of the present invention the term "embedded" or "embedded" relative to activated and ground sodium hexametaphosphate frit particles refers to said particles being found, either dispersed or agglomerated or aggregated, completely surrounded by the polymer matrix.
[0181] Without being linked to a particular theory, the authors of the present invention have observed that, by reducing the size of activated and ground sodium hexametaphosphate frit particles below d90 corresponding to 50 microns, preferably below 20 microns , and with special preference below 10 microns, and since these particles are embedded in a polymer matrix, their dispersion in the composite material is improved and the flow lines in the composite material are reduced.
[0182]
[0183] In a particular embodiment the composite material of the present invention comprises a polymeric matrix wherein the polymeric matrix comprises at least one thermosetting polymer, at least one thermoplastic polymer, at least one elastomeric polymer or combinations thereof; preferably at least one thermosetting polymer, at least one thermoplastic polymer or combinations thereof; more preferably at least one thermoplastic polymer; even more preferably a thermoplastic polymer; even more preferably a hydrophobic thermoplastic polymer.
[0184]
[0185] In the context of the present invention, the term "thermoplastic polymer" refers to a polymeric material that at relatively high temperatures, becomes deformable or flexible, melts when heated and hardens in a glass transition state when it cools. sufficient; preferably hydrophobic or hydrophobic.
[0186]
[0187] In a particular embodiment, the composite material of the present invention comprises a polymeric matrix, wherein said polymeric matrix comprises at least one thermoplastic polymer; preferably at least one thermoplastic polymer selected from polyetheretherketone, polyethylene terephthalate (PET), polyethylene (PE), high density polyethylene (HDPE), low density polyethylene (LDPE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene ( ); vinylidene polyfluoride, methyl polymethacrylate, polytetrafluoroethylene (PTFE), cellulosic polymers and derivatives, polyamide (PA), acrylonitrile butadiene styrene, polycarbonates; polyacetals, fluoroplastics and combinations thereof.
[0188]
[0189] In a preferred embodiment, the composite material of the present invention comprises a polymer matrix selected from polyethylene terephthalate (PET), high density polyethylene (HDPE), polyvinyl chloride (PVC), low density polyethylene (LDPE), polypropylene (PP ), polystyrene (PS), methyl polymethacrylate, polytetrafluoroethylineo, polyamide (PA), ABS resin, cellulose derivatives such as cellophane, polycarbonates, polyacetals and fluoroplastics.
[0190] In a more preferred embodiment, the composite material of the present invention comprises a polymer matrix of low density polyethylene (LDPE) or polypropylene (PP).
[0191]
[0192] In a particular embodiment, the composite material of the present invention comprises a polymer matrix; wherein the polymeric matrix comprises at least one thermostable polymer; preferably at least one thermostable polymer selected from phenolic, epoxy, amino urea, formaldehyde, polyurethane, polyester, vinyl ester, polyamide, silicone, nitrile, RTM6 or Hexcel 8852 resins.
[0193]
[0194] In the context of the present invention, the term "thermosetting polymer" refers to an infusible and insoluble polymeric material, preferably hydrophobic or hydrophobic.
[0195]
[0196] In a particular embodiment, the composite material of the present invention comprises a polymeric matrix wherein the polymeric matrix comprises at least one elastomeric polymer; preferably at least one elastomer polymer selected from natural rubber, polyisoprene, polychloroprene, polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene rubber, polychloroprene, neoprene, polyester, polysulfite, polyurethane and silicone.
[0197]
[0198] In a particular embodiment, the composite material of the present invention comprises a polymer matrix with a refractive index value between 1.3 and 1.7; preferably between 1.4 and 1.6.
[0199]
[0200] In a particular embodiment, the composite material of the present invention comprises a hydrophobic or hydrophobic polymer matrix; preferably hydrophobic.
[0201]
[0202] In a more preferred embodiment, the composite material of the present invention comprises a polymer matrix of a hydrophobic or hydrophobic polymer; preferably hydrophobic.
[0203]
[0204] In the context of the present invention the expression "hydrophobic surface" refers to a surface of a water repellent material.
[0205]
[0206] In the context of the present invention the terms "hydrophobic" and "hydrophilic" are antonyms and are related to the tendency of a material to interact with water.
[0207] In the context of the present invention the term "hydrophobic" refers to a material or substance that repels water or with low affinity for water and will be used in the sense of hydrophobic. In the context of the present invention the term "hydrophilic" refers to a material with affinity for water.
[0208]
[0209] In a more preferred embodiment, the composite material of the present invention can be formed by one or more conventional forming processes in the plastics industry, such as in conventional forming processes of thermoplastic or thermosetting materials. Non-limiting examples of forming processes are extrusion, pressure molding, blow molding, rotation molding, calendering, vacuum molding and the like.
[0210]
[0211] In a particular embodiment, the composite material of the present invention comprises activated and ground sodium hexametaphosphate frit particles in a mass percentage of less than 60%; preferably less than 40%; more preferably between 0.1% and 40%; even more preferably between 0.5 and 30%.
[0212]
[0213] In a particular embodiment, the composite material of the present invention comprises activated and ground sodium hexametaphosphate frit particles in a mass percentage of less than 6%; preferably between 0.1% and 5%; more preferably between 0.5 and 2.5% by mass.
[0214]
[0215] The composite material of the present invention comprises activated and ground sodium hexametaphosphate frit particles wherein said particles are embedded in said polymer matrix.
[0216]
[0217] In a particular embodiment, the composite material of the present invention retains water; preferably retains water; more preferably it retains water in a humid environment.
[0218]
[0219] In a particular embodiment, the composite material of the present invention comprises hydrophobic and hydrophilic areas on its surface.
[0220]
[0221] The authors of the present invention have observed that the composite material of the present invention has antimicrobial properties.
[0222] In a preferred embodiment, the composite material of the present invention has antibacterial properties.
[0223]
[0224] In a preferred embodiment, the composite material of the present invention has an antimicrobial response; preferably an antibacterial response; more preferably an antibacterial response against gram positive and gram negative bacteria; even more preferably against Staphylococcus aureus, Listeria innocua and Escherichia coli.
[0225]
[0226] In a preferred embodiment, the composite material of the present invention has an antimicrobial response; preferably an antibacterial response; more preferably an antibacterial response comprising reduction values of the population of bacteria (R) greater than 2; preferably greater than 3.
[0227]
[0228] In a preferred embodiment, the composite material of the present invention has an antimicrobial response in a moist environment; preferably an antibacterial response in moist environment.
[0229]
[0230] In a preferred embodiment, the composite material of the present invention has an antibacterial response comprising reduction values of the population of bacteria (R) greater than 2 for a time greater than 24 hours; preferably greater than 3 for a time greater than 24 hours.
[0231]
[0232] In a preferred embodiment, the composite material of the present invention has an antibacterial response comprising reduction values of the population of bacteria (R) greater than 2 for a period greater than 1 month; preferably reduction values of the population of bacteria (R) greater than 3 for a period greater than 1 month.
[0233]
[0234] In the context of the present invention the expression "reduction value of the population of bacteria (R)" is expressed by the formula:
[0235] R = Ut - At
[0236] where:
[0237] R: reduction of the population of bacteria (R) or reduction of bacterial activity or log reduction ( log reduction);
[0238] Ut: average of the logarithms of the bacterial count, in the control samples (without antimicrobial treatment), after 24 hours of incubation; Y
[0239] > 4t: average of the logarithms of the bacterial count, in the samples with antimicrobial treatment, after 24 hours of incubation.
[0240]
[0241] Therefore, in the context of the present invention, the number expressed as a reduction in the population of bacteria (R) is the ability to remove logarithmically, within 24 hours, of the bacteria that are in contact with the surface . The higher the R factor, the more effective is the ability of the treated material to eliminate the test microorganisms.
[0242]
[0243] In a particular embodiment, the composite material of the present invention prevents the formation of bio-films of bacteria or organized microbial ecosystems; preferably it comprises surfaces that prevent the formation of bio-films of bacteria or organized microbial ecosystems.
[0244]
[0245] In a particular embodiment, the composite material of the present invention is an antifouling material.
[0246]
[0247] In a particular embodiment, the composite material of the present invention comprises functionalized surfaces; preferably with polyethylene glycol (PEG) or with oligoethylene glycol.
[0248]
[0249] Without being linked to a particular theory, the authors of the present invention have observed that, by embedding the activated and ground sodium hexametaphosphate frit particles of the present invention in a polymer matrix to give rise to a composite material, it is obtained surprisingly a composite material with antimicrobial properties. Furthermore, it has been observed that said antimicrobial properties are maintained for a long time and work on different types of bacteria. Surprising surface characteristics have also been surprisingly observed.
[0250]
[0251] In a particular embodiment, the composite material of the present invention is in the form of a sheet or film; preferably in the form of translucent sheet or film; more preferably in the form of a colorless and translucent film sheet.
[0252]
[0253] In a particular embodiment, the composite material of the present invention is in the form of a film with a thickness between 1 and 1000 microns, preferably between 10 and 500 microns, more preferably between 20 and 200 microns.
[0254] In a particular embodiment, the composite material of the present invention is in the form of a film having a smooth surface; preferably with a roughness of less than 2 m, more preferably less than 1 m.
[0255]
[0256] In a particular embodiment, the composite material of the present invention is in the form of pellets.
[0257]
[0258] In the context of the present invention, the term "pellet" refers to a solid granulate form that can be taken by the composite material of the present invention for better handling and transport. Non-limiting examples of pellet are crystalline, amorphous agglomerates, (spherulites), small macaroni-type cylinders or vitreous-looking pearls.
[0259]
[0260] In a particular embodiment, the composite material of the present invention has a low toxicity.
[0261]
[0262] In a particular embodiment, the composite material of the present invention is non-toxic.
[0263]
[0264] In the context of the present invention, the term "toxicity" refers to a substance that can produce detrimental effects on a living being upon contact with it.
[0265]
[0266] In a particular embodiment, the composite material of the present invention comprises activated and ground sodium hexametaphosphate frit particles that may be dispersed or agglomerated in the polymer matrix.
[0267]
[0268] In a particular embodiment, the composite material of the present invention comprises activated and ground sodium hexametaphosphate frit particles dispersed in the matrix.
[0269]
[0270] In a particular embodiment the composite material of the present invention comprises activated and ground sodium hexametaphosphate frit particles uniformly dispersed in the matrix.
[0271]
[0272] Without being linked to a particular theory, the authors of the present invention have observed that the antimicrobial properties of the antimicrobial composite material are not affected by the state of the sodium hexametaphosphate frit particles activated and milled embedded in the polymer matrix are already dispersed or agglomerated.
[0273]
[0274] The composite material of the present invention comprises activated and ground sodium hexametaphosphate frit particles embedded in said polymer matrix.
[0275]
[0276] In a particular embodiment, the composite material of the present invention increases the dissolution time of the activated and ground sodium hexametaphosphate frit particles.
[0277]
[0278] In a particular embodiment, the composite material of the present invention comprises standardized conductivity values per gram of activated and ground sodium hexametaphosphate frit particles and per milliliter of water after 15 minutes in aqueous solution less than 0.7 mS.cm -1.g.ml-1.
[0279]
[0280] Furthermore, without being linked to a particular theory, the authors of the present invention have observed that the activated and ground sodium hexametaphosphate frit particles embedded in the polymer matrix have a conductivity value per gram in aqueous solution lower than the same particles. without embedding in the polymer matrix.
[0281]
[0282] In a particular embodiment, the composite material of the present invention further comprises at least one antimicrobial, antibiotic, antifungal, antiparasitic, antiviral or antiseptic additive; preferably an antimicrobial additive.
[0283]
[0284] In a particular embodiment, the composite material of the present invention further comprises at least one antimicrobial additive; preferably at least one antimicrobial additive selected from silver derivatives, copper derivatives, zinc derivatives, phenolic biocides, quaternary ammonium compounds, titanium oxides, fungicides such as thiabendazole, antimicrobial glasses and combinations thereof.
[0285]
[0286] In the context of the present invention, the term "antimicrobial" refers to substances that demonstrate the ability to eliminate, inhibit their growth or reduce the presence of microorganisms, such as bacteria, fungi or parasites and comprise antibiotic, antifungal, antiparasitic, antiviral substances. or antiseptics.
[0287] In a particular embodiment, the composite material of the present invention comprises silver derivatives; preferably positive silver ions (Ag +).
[0288]
[0289] In a particular embodiment, the composite material of the present invention further comprises at least one additive selected from plasticizers, stabilizers, lubricants, extenders, humectants, pore formers, impact modifiers, flame retardants, foaming agents, fillers, pigments, dyes , antistatic agents, adhesion promoters, reinforcers, antiwear agents and combinations thereof.
[0290]
[0291] In a particular embodiment, the composite material of the present invention comprises at least one additional layer comprising a material other than that of the composite material of the present invention.
[0292]
[0293] In a particular embodiment, the composite material of the present invention comprises organic functional groups; preferably organic functional groups with antibacterial properties.
[0294]
[0295] Applications
[0296]
[0297] A further aspect of the present invention is directed to the use of the composite material of the present invention as an antimicrobial agent; preferably as an antibacterial agent; more preferably as an antibacterial agent against gram positive bacteria and gram negative bacteria.
[0298]
[0299] In a particular embodiment, the use of the composite material of the present invention is in the cosmetic, medical and food industry; particularly in the food industry.
[0300]
[0301] In a more particular embodiment, the use of the composite material of the present invention is as a protective film in the food industry; preferably as an antibacterial contact film.
[0302]
[0303] In a particular embodiment, the use of the composite material of the present invention takes place in the industrial sector, in construction, in the packaging industry, in agriculture and in consumer industries.
[0304] In a particular embodiment, the use of the composite material of the present invention is in the form of containers, food packaging, bags and packaging, greenhouse plastics, raffia, irrigation pipes, films, cutlery, utensils, household appliances, personal hygiene products and personal care.
[0305]
[0306] Procedure for obtaining the composite material
[0307]
[0308] An inventive aspect is directed to a process for obtaining the composite material as defined above comprising the steps of:
[0309] i) provide
[0310] a) activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation process comprising the steps of:
[0311] i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0312] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0313] iii) grind the active sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles; Y
[0314] b) a polymer matrix; Y
[0315] ii) embedding said activated and ground sodium hexametaphosphate frit particles in said polymer matrix.
[0316]
[0317] In a particular embodiment, step (ii) of the process for obtaining the composite material of the present invention comprises embedding said activated sodium and hexametaphosphate frit particles in said polymer matrix; wherein said activated and ground sodium hexametaphosphate frit particles are completely coated by the polymer matrix.
[0318]
[0319] In a particular embodiment, step (ii) of the process for obtaining the composite material of the present invention comprises incorporating the activated and ground sodium hexametaphosphate frit particles into said polymer matrix by processes known to those skilled in the art; preferably mixing, melting and extrusion processes.
[0320] Thermal activation procedure
[0321]
[0322] Finally, a last inventive aspect of the present invention is directed to a method of thermal activation of a sodium hexametaphosphate salt to give rise to the activated and ground sodium hexametaphosphate frit particles as defined above comprising the stages of
[0323] i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
[0324] ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
[0325] iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles.
[0326]
[0327] The composite material, the method of obtaining said composite material and the method of activating a sodium hexametaphosphate salt to give rise to the activated and ground sodium hexametaphosphate frit particles of the present invention comprises all the features described for activated and ground sodium hexametaphosphate frit particles of the present invention in any of its particular embodiments.
[0328]
[0329] In addition, the process for obtaining the composite material of the present invention comprises all the features described for the composite material of the present invention in any of its particular embodiments.
[0330]
[0331] Examples
[0332]
[0333] The invention is described below by the following examples, which should be considered as merely illustrative and in no case limiting the scope of the present invention.
[0334]
[0335] Example 1: Obtaining activated sodium hexametaphosphate frit particles.
[0336]
[0337] Activated sodium hexametaphosphate frit particles were obtained as follows. 200 grams of sodium hexametaphosphate salt were heated with chemical formula (NaPO3) 6 in an alumina crucible of 600 ml capacity at 10 ° C / min to a temperature of 800 ° C that was maintained for 1 hour. Subsequently, the molten sodium hexametaphosphate salt was poured onto a bronze plate that was at room temperature. Thus, said molten salt was suddenly cooled to a temperature <300 ° C in a time of less than 1 minute forming irregular fragments in the form of transparent scales or granules, that is, particles of activated sodium hexametaphosphate frit.
[0338]
[0339] Example 2: Obtaining activated and ground sodium hexametaphosphate frit particles.
[0340]
[0341] Activated sodium hexametaphosphate frit particles were obtained according to example 1 which were subsequently milled according to two milling processes I and II at different sizes as described below. The particle sizes were determined from parameters d50 and d90 (also called mass medium diameters) of the particles that were determined dry using a laser analyzer of particle size distribution MASTERSIZER 2000 of the signature MALVERN. The particle size distribution or granulometric curve was statistically determined and characterized by parameters d50 and d90 defined as the equivalent size corresponding to 50% and 90% by weight respectively of the population of the accumulated distribution. The equivalent size refers to the diameter of the sphere that has the same specific area as the specified particle population.
[0342]
[0343] Milling Procedure I
[0344]
[0345] The transparent irregular fragments obtained in example 1 were manually crushed to obtain activated sodium hexametaphosphate frit with a size less than 1 cm.
[0346]
[0347] The sodium hexametaphosphate frit was ground dry in a 1000 ml laboratory planetary mill with 14-20 mm alumina balls for 30 minutes resulting in an activated and milled sodium hexametaphosphate frit with size distribution particle characterized by d50 parameters of d90 of 16.8 and 80.5 ^ m respectively. A second milling stage using 425 grams of zirconia stabilized micro-balls with itria sizes ranging from 0.6-1.5 mm in a 400 ml dry planetary laboratory mill and 100 grams of previously ground milled sodium hexametaphosphate frit , for 30 minutes produced particle sizes with parameters d50 and d90 of 11.3 and 52.85 ^ m respectively. An additional equivalent milling with zirconia stabilized micro-balls with itria sizes ranging from 0.3-0.6 mm, produced an activated and ground sodium hexametaphosphate frit with an average d50 size of d90 of 8.5 and 44.3 ^ m which was later characterized in examples 3-5.
[0348]
[0349] Milling Procedure II
[0350]
[0351] Alternatively, the activated sodium hexametaphosphate frit particles according to example 1 were milled by an alternative milling process as follows. The transparent irregular fragments obtained in Example 1 were fractionated using a tungsten carbide jaw mill to obtain fragments smaller than 200 m. These fragments were milled in a tungsten carbide ring mill for 1 minute. The result of the milling was activated and ground sodium hexametaphosphate frit particles with a particle size characterized by a d50 of 4.2 ^ m and a d90 of 8.3 ^ m which were subsequently characterized in Examples 3-6.
[0352]
[0353] Comparative example 3: structure of the particles of the activated and ground sodium hexametaphosphate frit and the sodium hexametaphosphate salt.
[0354]
[0355] For comparative purposes, the structure of the activated and ground sodium hexametaphosphate frit particles of Example 2 and the sodium milled salt also ground in the same way was evaluated.
[0356]
[0357] The structure of the samples was studied by Raman spectroscopy using an i-Raman 785S device from the BWTEK house with a 785 nm laser. Figure 1 shows the Raman spectra obtained for (a) the activated and ground sodium hexametaphosphate frit particles (solid line) and for (b) the ground sodium hexametaphosphate salt (dashed line). The main Raman modes characteristic of the structure of sodium hexametaphosphate were present in the two samples as follows: vibrational modes of symmetric stretching of bridge oxygen between POP tetrahedra located ca. 683 cm "1, symmetrical stretching of terminal oxygens in PO2 units that are doubly connected forming chains of tetrahedra type Q2 to ca. 1163 cm" 1 and symmetrical stretching of terminal oxygens P = O found in three-dimensional networks of tetrahedrons type Q3 located ca. 1280cm-1 The vibration modes located below 400 cm-1 correspond to bending modes of the tetrahedron chain network.
[0358]
[0359] Figure 2 shows an enlarged sample of the Raman spectra obtained for (a) the activated and ground sodium hexametaphosphate frit particles (solid line) and for (b) the ground sodium hexametaphosphate salt (broken line). Structurally, the main difference between milled sodium hexametaphosphate salt and activated and milled sodium hexametaphosphate frit particles consisted of a smaller redshift of the Raman mode corresponding to the symmetrical stretching of the terminal oxygen in PO2 units formed by chains of type Q2 tetrahedra that reduces from a Raman displacement value for the milled salt to 1163 cm-1 to a value of 1161.5 cm-1 for the milled frit (Figure 2). This lower Raman shift value for activated and ground sodium hexametaphosphate frit particles is associated with a lower force constant of said bond or a longer bond length. Therefore, the Q2 tetrahedra network in the milled frit has a more open network compared to the starting material of the sodium hexametaphosphate salt.
[0360]
[0361] Comparative Example 4: Water absorption capacity of the particles of the activated and ground sodium hexametaphosphate frit and of the milled sodium hexametaphosphate salt.
[0362]
[0363] For comparative purposes, the water absorption capacity of: the starting sodium hexametaphosphate salt, the ground starting sodium hexametaphosphate salt, the activated sodium hexametaphosphate frit particles and the fused hexametaphosphate frit particles were evaluated. activated and milled sodium of Example 3.
[0364]
[0365] The samples were exposed to an ambient humidity of 40-45% for 48 hours and the water absorption capacity was studied by means of thermogravimetric curves recorded in a TGA Q50 unit of the TA Instruments house.
[0366]
[0367] Figure 3 shows the comparative thermogravimetric curves corresponding to the starting sodium hexametaphosphate salt (solid line Figure 3a), the ground sodium hexametaphosphate salt (dashed line Figure 3a), the activated sodium hexametaphosphate frit particles ( solid line Figure 3b) and the activated and ground sodium hexametaphosphate frit particles (dashed line Figure 3b). The main differences observed between the samples consist of the% loss of weight and the temperatures at which said weight losses take place. The starting sodium hexametaphosphate salt suffered a mass loss at 600 ° C of 2.5% by weight while for the activated sodium hexametaphosphate frit particles said loss was 5.3% by weight and for the Sodium hexametaphosphate frit particles activated and ground was 12.8% by weight.
[0368]
[0369] Comparative example 5: dissolution rate of the particles of the activated and ground sodium hexametaphosphate frit and of the milled sodium hexametaphosphate salt particles.
[0370]
[0371] For comparative purposes, the dissolution rate of the milled sodium hexametaphosphate salt and the activated and milled sodium hexametaphosphate frit particles of Example 3 with an average d50 size of d90 of 8.5 and 44.3 ^ m was evaluated . For this, the conductivity variation was determined in a suspension of 0.5 grams of the product to be evaluated in 50 ml of deionized water whose conductivity value is 12.6 ^ S / cm.
[0372]
[0373] Figure 4 shows the conductivity values (mS / cm) versus time for the milled sodium hexametaphosphate salt (square symbol) and for the activated and milled sodium hexametaphosphate frit particles (round symbol). Although in both cases the maximum conductivity achieved was the same (Figure 4), of 3.83 mS / cm, in the frit particles this value was reached at 200 seconds, while the salt requires more time to reach that value , about 450 seconds. The values obtained for the activated and ground sodium hexametaphosphate frit particles with a particle size characterized by a d50 of 4.2 ^ m and a d90 of 8.3 ^ m of Example 2 were similar to those of the activated particles and milled with an average d50 size of d90 of 8.5 and 44.3 ^ m. Therefore, the particles of the activated and ground sodium hexametaphosphate frit have a faster dissolution rate than the initial ground sodium hexametaphosphate salt.
[0374]
[0375] Example 6: encapsulation of the particles of the activated sodium hexametaphosphate frit in a polymer matrix to give a composite material.
[0376]
[0377] The activated and ground sodium hexametaphosphate frit particles with a particle size characterized by a d50 of 4.2 ^ m and a d90 of 8.3 ^ m of Example 2 were incorporated into low density polyethylene, LDPE (acronym of the name in English).
[0378] First the particles were incorporated into a pellet of LDPE polymer resulting in a concentrated product or masterbach. For this, the activated sodium hexametaphosphate frit particles were dried at a temperature between 80-160 ° C. Next, the activated and ground sodium hexametaphosphate frit particles were incorporated into the polymer in a weight percentage of 20% by polymer mixing, melting and extrusion processes. In a first stage the polymer was melted or heated to a visco-elastic state, mixed with the activated and ground sodium hexametaphosphate frit particles. Then the molten polymer (or visco-elastic state) was forced to pass through a die also called a head, by means of the thrust generated by the rotating action of a spindle that rotates concentrically and is passed through a mold in charge of give the desired shape in a twin-screw extruder in a temperature range between 160-205 ° C obtaining the masterbach or concentrated material of activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix.
[0379]
[0380] By adding LDPE pellets to the concentrated product or masterbach described above and by a new mixing, melting and extrusion process, a composite material with a mass percentage of activated and ground sodium hexametaphosphate frit particles embedded in the film was obtained polymeric of 2% and a thickness of 80 ± 4 ^ m. Said composite material has a uniform appearance and high transparency thanks to the values of the refractive indexes of the 1.48 frit particles and the LDPE with a value of 1.51. The percentage of activated and ground sodium hexametaphosphate frit particles that are incorporated into the polymer matrix of LDPE from 0.1 to 5% by mass was observed, observing similar results.
[0381]
[0382] The same process of obtaining a concentrated composite material and obtaining a composite material with concentrations from 0.1% to 5% by weight of activated sodium hexametaphosphate frit particles was repeated using polypropylene (PP). In addition, the process was also repeated to obtain the corresponding composite materials of hexametaphosphate salt particles.
[0383]
[0384] Example 7: Characterization of activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix.
[0385]
[0386] The composite material described in Example 6 with 2% particles of activated and ground sodium hexametaphosphate frit was characterized by microscopy Confocal Raman (WITEC Alfa 500). Figure 5 shows a Raman image where in each pixel the image corresponds to a Raman spectrum. The activated and ground sodium hexametaphosphate frit particles are embedded in isolation (with a darker color and contour and marked with (1)) isolated in the continuous matrix of LDPE polymer (lighter in color and marked with (2) ). Figure 5 shows activated and milled frit particles that are inside the LDPE film with particle size values less than 15 microns.
[0387]
[0388] Example 8: dissolution rate of the particles of the activated sodium hexametaphosphate frit, milled and encapsulated in a polymer matrix.
[0389]
[0390] The dissolution rate of the activated, milled and encapsulated sodium hexametaphosphate frit particles was evaluated in an LDPE polymer matrix of Example 6. The conductivity variation of 0.056 g of a composite film containing 2% was determined. by weight of activated and ground sodium hexametaphosphate frit, to be evaluated in 100 ml of deionized water whose conductivity value is 3.3 ^ S.cm-1. Figure 6 shows the conductivity values (^ S / cm) versus time for activated and ground sodium hexametaphosphate frit particles embedded in low density polyethylene. The conductivity achieved by the composite material at around 900 seconds was 5.5 ^ S.cm-1 since the conductivity of the water was 3.3 ^ S.cm-1, the sodium hexametaphosphate frit particles activated encapsulated in the polymer contributed 2.2 ^ S.cm-1 to the conductivity of water. The normalized value of conductivity given per unit of gram of salt and milliliter of water after 15 minutes corresponded to 0.196 mS.cm-1g.ml-1 which is a value clearly lower than the values reached by the "free" particles of frit of sodium hexametaphosphate activated and milled at the same time as in example 5 corresponding to 0.766 mS.cm-1g.ml-1, thus dissolving the activated and ground sodium hexametaphosphate frit particles embedded in a polymer in an aqueous solution, it is significantly reduced so that the time of availability of inorganic particles in the polymer matrix is increased.
[0391]
[0392] Example 9: surface characterization of the composite material comprising activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix.
[0393] The surface of a film formed by the composite material comprising activated and ground sodium hexametaphosphate frit particles encapsulated in a polymeric matrix according to example 6 was characterized.
[0394]
[0395] Said film was immersed in water for at least 15 minutes. It was then extracted, dried in an oven at 60 ° C for 1 hour and again observed by Confocal Raman Microscopy. Figure 7a shows a confocal optical image showing the presence of small drops of liquid (3) on the surface of the polymer (2) that are in the vicinity of the frit particles (4). That is, said areas of the surface of the composite material near a particle of activated sodium hexametaphosphate frit act as hydrophilic zones and the rest of the surface acts as hydrophobic zones.
[0396]
[0397] Figure 7b shows the characteristic Raman spectra of the main elements (4), (3) and (2) shown in Figure 7a. An analysis by Raman spectroscopy of the nature of the spherical drops of liquid (3) confirmed that these drops contain water by the presence of a Raman band located in the region of 3000-3500 cm "1 and structural units of sodium hexametaphosphate similar to those present in dispersed and encapsulated activated sodium hexametaphosphate frit particles (4) in the polymeric film (2) The liquid drops are therefore stabilized by the presence of sodium hexametaphosphate structural units, in particular by the presence of bridge oxygen between PO-tetrahedra that are strongly displaced towards blue and symmetrical stretching modes of terminal oxygen in PO2 units that are displaced towards red.These structural modifications are indicative of the presence of units of depolymerized phosphorus tetrahedra. Raman spectra also demonstrated that Sodium hexametaphosphate frit particles activated and milled encapsulated in the polymer matrix (4) have water inside the polymer film after immersion in water. To a lesser extent, active, milled and dispersed frit particles inside the polymer undergo a depolymerization process after immersion in water. The presence of drops containing water and depolymerized phosphorus tetrahedra units allow the coexistence of polymeric regions with hydrophobic characteristics together with hydrophilic regions related to the presence of activated frit particles of sodium hexametaphosphate, milled and incorporated into the polymer matrix.
[0398] Figure 8 shows the surface of the polymeric film formed by the composite material comprising activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix according to example 6. Said film was exposed to ambient humidity for 60 days and observed by scanning electron microscopy (FESEM Hitachi S-4700). The film was observed after drying in an oven at 60 ° C for 1 hour and after depositing a layer of gold <100 nm on its surface The film shows the presence of multiple drops of liquid distributed on the surface of the polymeric film (Figure 8b ). The distances between adjacent drops of liquid observed on the surface of the composite material are less than 10 ^ m, presenting regions where the distance between drops is even less than 1 ^ m. These drops are generated by the existence of a vacuum in the observation chamber of the electron microscope and indicate the positions where there are particles of milled frit dispersed in the polymer matrix. This arrangement of hydrophilic regions on a hydrophobic surface represents an unexpected aspect of encapsulation of the milled frit particles in the present invention. These surfaces are characteristic of antifouling surfaces that are usually designed from hydrophobic and hydrophilic polymer blends.
[0399]
[0400] Example 10: Antimicrobial test of the surface of the composite material comprising activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix.
[0401]
[0402] The antibacterial tests performed were based on the “ISO 22196: 2011 standard. Measurement of antibacterial activity on plastics and other nonporous surfaces ”.
[0403]
[0404] Antimicrobial assays were performed on 8 samples consisting of a colorless and translucent polymeric sheet. Two types of polymers: low density polyethylene (LDPE) and polypropylene (PP) were studied. Four samples were tested for each polymer: a polymer sheet; a polymer sheet incorporating 1% by weight of hexametaphosphate salt; a polymer sheet and incorporating 0.5% by weight of activated and ground sodium hexametaphosphate frit microparticles; and a polymer sheet incorporating 1% by weight of activated and ground sodium hexametaphosphate frit microparticles. In both cases, the plastic films were cut into 5 x 5 cm pieces before the test was carried out.
[0405]
[0406] The following microorganisms were used to perform the test:
[0407] - Gram positive bacteria: Staphylococcus aureus and Listeria innocua; Y
[0408] - Gram negative bacteria: Escheríchia coli
[0409]
[0410] The test microorganisms were pre-incubated and cultured according to the requirements of ISO 22196. After reconstitution, an inoculum at a concentration of 106 cfu / ml was prepared for each of the microorganisms.
[0411]
[0412] The samples (polymer sheets) were placed in sterile plates and each was inoculated with aliquots of the prepared suspension of the test microorganism used in each case, according to the surface size, as indicated by ISO 22196. Subsequently, a sterile plastic film was deposited on each aliquot so that a thin layer of the suspension was generated under the film and in contact with the antibacterial surface of the sample. After inoculation the count of microorganisms on 3 samples was performed to determine the amount of microorganisms recovered before incubation. For this, the inoculated samples were introduced in a Stomacher® bag to which 10 ml of culture broth (Agar with Lecithin, Polysorbate SCDLP) is added. The sample and film were washed so that the microorganisms present are recovered in the broth. With the resulting solution, the microorganisms were counted in Plate Count Agar ( PCA) culture medium , at an incubation temperature of 35 ± 1 ° C for 48 hours.
[0413]
[0414] After inoculation of the remaining samples, incubation was carried out for 24 ± 1h at 35 ± 1 ° C and a minimum relative humidity of 90%. After the incubation period, and following the procedure indicated previously, the samples were counted, in order to determine the antibacterial activity value of the test materials.
[0415]
[0416] From the results obtained, the antibacterial activity that will be expressed by the reduction value of the population of bacteria (R) defined as follows was calculated:
[0417] R = Ut - At
[0418] Where:
[0419] R: reduction of the population of bacteria (R) or reduction of bacterial activity or log reduction ( log reduction );
[0420] Ut: average of the logarithms of the bacterial count, in the control samples (without antimicrobial treatment), after 24 hours of incubation; Y
[0421] At: mean of the logarithms of the bacterial count, in the samples with antimicrobial treatment, after 24 hours of incubation.
[0422] The number expressed as a value of reduction of the population of bacteria (R) is the ability to eliminate on a logarithmic basis, within 24 hours, the bacteria that are in contact with the surface treated with the antibacterial agent. The higher the R factor, the more effective is the ability of the treated material to eliminate the test microorganisms.
[0423]
[0424] The tests were repeated in cultures maintained for one month under the incubation conditions.
[0425]
[0426] Table 1. Results of antimicrobial tests.
[0427]
[0428]
[0429]
[0430]
[0431] R values correspond to an effective antimicrobial product for both types of bacteria, gram positive and gram negative bacteria. Table 1 shows the results of the antimicrobial tests performed on the different samples studied. It should be noted that while the control samples and samples of a polymeric material comprising initial sodium hexametaphosphate salt have not given any R value, samples of a composite material comprising activated and milled sodium hexametaphosphate frit particles encapsulated in a polymer matrix gave values of R higher than 2 and in most of the tests, R> 3 values are recorded. Therefore, Table 1 demonstrates the antimicrobial effect of activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix.
[0432]
[0433] In addition, R values in times greater than 24 hours should be noted for composite materials comprising 0.5 to 1% by mass of activated and ground frit particles.
[0434]
[0435] Example 11: Antimicrobial test of the surface of the composite material comprising activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix.
[0436]
[0437] The antimicrobial capacity of a polymeric sheet of the composite material comprising activated and ground sodium hexametaphosphate frit particles encapsulated in a polymer matrix was studied. For this purpose, the developed Clean TraceTM technique, surface Total ATP, was used to evaluate the load of microorganisms with an ATP marker.
[0438]
[0439] A gram negative bacterium, Proteus mirabilis , was used to perform the test . This bacterium was diluted in water in a 1/100 ratio, leaving an initial load of 4365 URLs (relative units of light). After 24 h, the bacterial load in said aqueous solution was measured resulting in 1995 URL (Table 2).
[0440]
[0441] The samples evaluated as polymeric sheets are: the composite material comprising activated and ground sodium hexametaphosphate frit particles encapsulated in an LDPE polymer matrix with a 1% by weight charge of frit particles against the same product without said particles. In addition, in the same test, a polymeric LDPE sheet comprising a load of 1.6% by weight of a soluble silver antimicrobial glass was also evaluated. You took the samples were the same size, mass and thickness.
[0442]
[0443] The results were collected in URL (relative units of light), which determine the presence of bacteria in the water, using ATP, which is a measure of energy and marks the presence of bacteria.
[0444] Table 2. Antimicrobial assays by ATP marker.
[0445]
[0446]
[0447]
[0448]
[0449] Table 2 shows the results of the antimicrobial tests performed on the different samples studied. In the tests carried out, it was demonstrated that the antimicrobial capacity studied by the ATP test shows a greater reduction of relative light units for a composite material comprising activated and molded sodium hexametaphosphate frit particles encapsulated in a polymer matrix, than for a polymer matrix. composite material comprising a standard glass-based antimicrobial additive comprising positive silver ions (Ag +).
[0450]
[0451] Once the nature of the present invention has been sufficiently described, as well as at least one way of putting it into practice, it only remains to be added that, as a whole and its parts, it is possible to introduce changes in form, materials and arrangement as long as said alterations do not substantially vary said invention.

权利要求:
Claims (17)
[1]
1. Composite material comprising:
a) activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation procedure comprising the steps of: i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles; Y
b) a polymer matrix;
wherein said activated and ground sodium hexametaphosphate frit particles are embedded in said polymer matrix.
[2]
2. The composite material according to claim 1, wherein the activated and ground sodium hexametaphosphate frit particles have a d90 parameter of less than 10 microns.
[3]
3. The composite material according to any one of claims 1 or 2, wherein the activated and ground sodium hexametaphosphate frit particles comprise a mass percentage of absorbed water greater than 2.5%.
[4]
4. The composite material according to any of claims 1-3, wherein the activated and ground sodium hexametaphosphate frit particles have refractive index values between 1.4 and 1.6
[5]
5. The composite material according to any one of claims 1-4, wherein said composite material comprises the sodium hexametaphosphate frit particles activated and ground in a mass percentage of less than 60%.
[6]
6. The composite material according to any one of claims 1-5, wherein said composite material comprises activated and ground sodium hexametaphosphate frit particles in a mass percentage comprised between 0.1 and 5%.
[7]
7. The composite material according to any of claims 1-6, wherein the polymer matrix is hydrophobic.
[8]
8. The composite material according to any of claims 1-7, wherein the polymeric matrix comprises at least one thermosetting polymer, at least one thermoplastic polymer or combinations thereof.
[9]
9. The composite material according to any one of claims 1-8, comprising conductivity values normalized per gram of frit particles and milliliters of water of sodium hexametaphosphate frit particles activated and milled after 15 minutes in aqueous solution less than 0.700 mS.cm "1.g.ml" 1.
[10]
10. The composite material according to any of claims 1-9, which comprises hydrophobic and hydrophilic areas on its surface.
[11]
11. The composite material according to any of claims 1-10, comprising at least one antimicrobial additive.
[12]
12. The composite material according to claim 11, wherein said at least one antimicrobial additive is selected from silver derivatives, copper derivatives, zinc derivatives, phenolic biocides, quaternary ammonium compounds, titanium oxides, fungicides such as thiabendazole, antimicrobial glasses and combinations thereof.
[13]
13. Use of the composite material defined in any one of claims 1 to 12 as an antimicrobial agent.
[14]
14. Use of the composite material according to claim 13 as an antibacterial agent against gram positive and gram negative bacteria.
[15]
15. Method of obtaining the composite material defined in any one of claims 1 to 12 comprising the steps of:
i) provide
a) activated and ground sodium hexametaphosphate frit particles obtainable by a thermal activation process comprising the steps of:
i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles; Y
b) a polymer matrix; Y
ii) embedding said activated and ground sodium hexametaphosphate frit particles in said polymer matrix.
[16]
16. Activated and milled sodium hexametaphosphate frit particles obtainable by a thermal activation process comprising the steps of:
i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles.
[17]
17. Method of thermal activation of a sodium hexametaphosphate salt to give rise to the activated and ground sodium hexametaphosphate frit particles defined in claim 16 comprising the steps of:
i) heating a sodium hexametaphosphate salt until melted so that a molten salt of sodium hexametaphosphate is obtained;
ii) cooling the molten sodium hexametaphosphate salt obtained in step (i) suddenly in dry medium to obtain activated sodium hexametaphosphate frit particles; Y
iii) grind the activated sodium hexametaphosphate frit particles obtained in step (ii) to obtain activated and ground sodium hexametaphosphate frit particles.

类似技术:

---

公开号 | 公开日 | 专利标题

---

Kanmani et al.2014|Physical, mechanical and antimicrobial properties of gelatin based active nanocomposite films containing AgNPs and nanoclay

---

Hajji et al.2017|Nanocomposite films based on chitosan–poly | and silver nanoparticles with high antibacterial and antioxidant activities

---

Sani et al.2019|Preparation of chitosan/zinc oxide/Melissa officinalis essential oil nano-composite film and evaluation of physical, mechanical and antimicrobial properties by response surface method

---

Ghadetaj et al.2018|Development and characterization of whey protein isolate active films containing nanoemulsions of Grammosciadium ptrocarpum Bioss. essential oil

---

Divsalar et al.2018|Characterization of cellulosic paper coated with chitosan-zinc oxide nanocomposite containing nisin and its application in packaging of UF cheese

---

Espitia et al.2016|Zinc oxide nanoparticles for food packaging applications

---

Cha et al.2002|Antimicrobial films based on Na-alginate and κ-carrageenan

---

Sayanjali et al.2011|Evaluation of antimicrobial and physical properties of edible film based on carboxymethyl cellulose containing potassium sorbate on some mycotoxigenic Aspergillus species in fresh pistachios

---

Incoronato et al.2010|Active systems based on silver-montmorillonite nanoparticles embedded into bio-based polymer matrices for packaging applications

---

Azlin-Hasim et al.2016|The potential application of antimicrobial silver polyvinyl chloride nanocomposite films to extend the shelf-life of chicken breast fillets

---

Amna et al.2015|Electrospun antimicrobial hybrid mats: Innovative packaging material for meat and meat-products

---

Lomate et al.2018|Development of antimicrobial LDPE/Cu nanocomposite food packaging film for extended shelf life of peda

---

Pandit et al.2017|Enhanced antimicrobial activity of the food-protecting nisin peptide by bioconjugation with silver nanoparticles

---

Eskandarabadi et al.2019|Active intelligent packaging film based on ethylene vinyl acetate nanocomposite containing extracted anthocyanin, rosemary extract and ZnO/Fe-MMT nanoparticles

---

WO2017106984A1|2017-06-29|Degradable packaging film for fruit and vegetables

---

Shin et al.2013|Physical properties of a barley protein/nano‐clay composite film containing grapefruit seed extract and antimicrobial benefits for packaging of A garicus bisporus

---

Barani et al.2018|Increasing the shelf life of pikeperch | fillets affected by low-density polyethylene/Ag/TiO2 nanocomposites experimentally produced by sol-gel and melt-mixing methods

---

Ghamari et al.2021|Physical, mechanical, and antimicrobial properties of active edible film based on milk proteins incorporated with Nigella sativa essential oil

---

Deng et al.2019|Nano-silver-containing polyvinyl alcohol composite film for grape fresh-keeping

---

Mousavi et al.2016|Investigation into shelf life of fresh dates and pistachios in a package modified with nano-silver

---

Seray et al.2021|Kinetics and mechanisms of Zn2+ release from antimicrobial food packaging based on poly | and zinc oxide nanoparticles

---

Gupta et al.2019|Bicompartmental microparticles loaded with antibacterial agents for prolonging food shelf life

---

ES2734497B2|2021-07-22|Antimicrobial composite material

---

Singh et al.2015|Comparative study on antimicrobial efficiency of AgSiO2, ZnAg, and Ag-Zeolite for the application of fishery plastic container

---

Gendaszewska et al.2018|Antimicrobial Activity of Monolayer and Multilayer Films Containing Polyhexamethylene Guanidine Sulphanilate

同族专利:

---

公开号 | 公开日

---

EP3816126A1|2021-05-05|

---

ES2734497B2|2021-07-22|

---

EP3816126A4|2022-03-02|

---

CL2020003150A1|2021-06-11|

---

WO2019234276A1|2019-12-12|

---

US20210214223A1|2021-07-15|

引用文献:

---

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

---

WO2011129982A2|2010-04-14|2011-10-20|Avery Dennison Corporation|Methods for increasing effectiveness of antimicrobial agents in polymeric films|

---

EP2886520A1|2013-12-19|2015-06-24|Nanobiomatters Bactiblock, S.L.|Antibacterial glass|

---

CN104542895B|2014-12-12|2018-03-06|仲恺农业工程学院|A kind of composite cold fresh-keeping agent for meat and preparation method thereof|

---

CN104961469A|2015-07-03|2015-10-07|江苏脒诺甫纳米材料有限公司|Whitening agent for ceramic blank body and preparation method thereof|

---

法律状态:
2019-12-10| BA2A| Patent application published|Ref document number: 2734497 Country of ref document: ES Kind code of ref document: A1 Effective date: 20191210 |

---

2021-07-22| FG2A| Definitive protection|Ref document number: 2734497 Country of ref document: ES Kind code of ref document: B2 Effective date: 20210722 |

优先权:

---

申请号 | 申请日 | 专利标题

---

ES201830547A|ES2734497B2|2018-06-05|2018-06-05|Antimicrobial composite material|ES201830547A| ES2734497B2|2018-06-05|2018-06-05|Antimicrobial composite material|

---

US15/734,264| US20210214223A1|2018-06-05|2019-06-04|Antimicrobial composite material|

---

PCT/ES2019/070378| WO2019234276A1|2018-06-05|2019-06-04|Antimicrobial composite material|

---

EP19815098.9A| EP3816126A4|2018-06-05|2019-06-04|Antimicrobial composite material|

---

CL2020003150A| CL2020003150A1|2018-06-05|2020-12-03|Antimicrobial composite material|