Classifications

• • 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
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
• • 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
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
  • C08J3/22—Compounding polymers with additives, e.g. colouring using masterbatch techniques
  • C08J3/226—Compounding polymers with additives, e.g. colouring using masterbatch techniques using a polymer as a carrier
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82B—NANOSTRUCTURES FORMED BY MANIPULATION OF INDIVIDUAL ATOMS, MOLECULES, OR LIMITED COLLECTIONS OF ATOMS OR MOLECULES AS DISCRETE UNITS; MANUFACTURE OR TREATMENT THEREOF
  • B82B3/00—Manufacture or treatment of nanostructures by manipulation of individual atoms or molecules, or limited collections of atoms or molecules as discrete units
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/48—Polymers modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
• • 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
  • C08J2377/00—Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers
• • 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
  • C08J2477/00—Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers

Definitions

• the present invention relates to a method for producing polyamide nanocomposites from polyamides and phyllosilicates in accordance with the preamble of independent claim 1.
• Polyamide nanocomposites produced according to the present method according to the invention can be used to produce transparent packaging materials, in particular packaging materials with high UV absorption, and improved gas and aroma barriers can be used.
• the polyamide nanocomposites produced according to the invention offer the possibility of producing shaped bodies, hollow bodies, semi-finished products, plates, tubes, etc., even with greater thickness or wall thickness.
• nanocomposite materials are polymer formulations which have finely dispersed layered silicates, for example clay or clay minerals, within the polymer matrix.
• Nanocomposites have also found their way into the packaging sector.
• the exfoliated clay minerals cause an inhibited diffusion of gas molecules such as oxygen, carbon dioxide or aromatic substances through the packaging material.
• Polyamides have been established as preferred thermoplastic polymer materials in the packaging sector for years.
• One of the main reasons for this is the property profile of this material class, such as good barrier properties against oxygen and carbon dioxide, and the excellent mechanical properties of the packaging films made from polyamide.
• aliphatic polyamides as a matrix for nanocomposite materials, a reduction in transparency can be observed, since these nanocomposite fillers can increase the crystallization of the aliphatic polyamides, which in turn can severely impair the transparency of such products.
• a targeted goal in the packaging sector is to use the polyamide nanocomposite as part of multilayer films in combination with other polymers such as polyolefins.
• Multi-layer films which are made up of different types of polymer with poor mutual adhesion can be firmly bonded by means of suitable adhesion-promoting layers. From such additional Layered films can be used to produce a wide variety of packaging products, such as containers, bottles, bags, thermoformable products, tubes, etc.
• the products can be colored, translucent or transparent.
• the presentation of these products to buyers plays an increasingly important role. So that customers can see what is in the packaging, the transparency is of crucial importance.
• Many suitable barrier materials consist of aliphatic polymers. Such • compounds usually crystallize during the cooling process and give packaging materials with reduced transparency. The reduction of transparency through the crystallization process can be eliminated by using amorphous, partially aromatic polyamides.
• the shelf life of packaged perishable food and other products is mainly determined by the oxygen barrier of a packaging.
• the UV barrier also plays a decisive role in numerous other packaging applications, since UV rays can also damage sensitive foods (similar to oxygen).
• sensitive food e.g. Meat products in the refrigerated counters of the large distributors are often subject to damaging UV rays, since many of the light sources used also emit in the UV spectrum.
• the invention is therefore based on the object of proposing a process for the production of polyamide nanocomposites with which, inter alia, transparent and clear packaging material or packaging material with high mechanical properties, high barrier action against oxygen and carbon dioxide can be produced, which at the same time also increases Have protection against UV rays.
• this object is achieved in accordance with the features of independent claim 1.
• this object is achieved according to the features of claim 13. Additional inventive features result from the dependent claims.
• the polyamide nanocomposite materials are produced by admixing an organically modified layered silicate in a compounding process, using a twin-screw extruder (for example using a “WP ZSK 25” from Werner & Pfleiderer).
• a twin-screw extruder for example using a “WP ZSK 25” from Werner & Pfleiderer.
• FN film grade
• a flat film is extruded from the granulate, for example with a Plasti-Corder from Brabender.
• the film is guided past an optical system that detects the contaminants in the film, counts (given per m 2 ) and determines their size.
• Such an optical system with evaluation program is sold by the company OCS GmbH Witten under the name "Foil Test FT4".
• the impurities are divided into 10 size classes (see Table 2). These classes are weighted with different weight factors. Table 2:
• the film grade is calculated according to the following formula by adding the sum of the weighted impurities per size class and dividing by 1000.
• Layered silicates in the sense of the invention are understood to mean 1: 1 and 2: 1 layered silicates.
• layers of SiO 4 tetrahedra are regularly linked with those of M (O, OH) 6 octahedra.
• M stands for metal ions such as Al, Mg, Fe.
• a tetrahedron and an octahedron layer are connected to each other. Examples of this are kaolin and serpentine minerals.
• Examples of 2: 1 layered silicates are talc, mica, vermiculite, illite and smectite, the smectites, which include montmorillonite and hectorite, being easily swellable with water due to their layered charge. Furthermore, the cations are easily accessible for exchange processes.
• the layer thicknesses of the layered silicates are usually 0.5 nm to 2.0 nm before swelling, very particularly preferably 0.8 nm to 1.5 nm (distance of the upper layer edge to the following upper layer edge). It is possible to further increase the layer spacing by using the layered silicate, for example, with polyamide monomers, e.g. B. at temperatures from 25 ° C to 300 ° C, preferably from 80 ° C to 280 ° C and in particular from 80 ° C to 160 ° C over a residence time of usually 5 to 120 minutes, preferably from 10 to 60 minutes , implements (swelling).
• polyamide monomers e.g. B. at temperatures from 25 ° C to 300 ° C, preferably from 80 ° C to 280 ° C and in particular from 80 ° C to 160 ° C over a residence time of usually 5 to 120 minutes, preferably from 10 to 60 minutes , implements (swelling).
• the layer spacing is additionally increased by 1 nm to 15 nm, preferably by 1 nm to 5 nm.
• the length of the platelets is usually up to 800 nm, preferably up to 400 nm or prepolymers that build up generally also contribute to the swelling of the layered silicates.
• the swellable layered silicates are characterized by their ion exchange capacity CEC (meq / g) and their layer spacing d. Typical values for CEC are 0.7 to 0.8 meq / g.
• the layer spacing for a dry untreated montmorillonite is 1 nm and increases to values of up to 5 nm due to swelling with water or coating with organic compounds.
• Examples of cations that can be used for exchange reactions are ammonium salts of primary amines with at least 6 carbon atoms such as hexanamine, decanamine, dodecanamine, stearylamines, hydrogenated fatty acid amines or quaternary ammonium compounds and ammonium salts of ⁇ -, ⁇ -amino acids with at least 6 carbon atoms. Chlorides, sulfates or phosphates are suitable as anions. In addition to ammonium salts, sulfonium or phosphonium salts such as tetraphenyl or tetrabutylphosphonium halides can also be used.
• adhesion promoters can also be used to treat the minerals. Titanates or silanes such as ⁇ -aminopropyltriethoxysilane are suitable here.
• polyamide nanocomposite formulations were produced with additions of 5% by weight and 8% by weight of organically modified layered silicates.
• a PA 6 which is commercially available under the name "Grilon F 40 NL", from EMS-CHEMIE AG, was produced with 5% by weight of modified layered silicate.
• the polyamide nanocomposite was produced by adding special modified layered silicate.
• layer silicates which have been modified, for example, with onium ions can thus be used according to the invention.
• modified layered silicates are commercially available from several companies, for example Südchemie (D), Southern Clay Products (USA), Nanocor (USA), CO-OP (J).
• the modified layered silicates used for the comparative examples and examples according to the invention are quaternary ammonium ions treated montmorillonite.
• the nitrogen ligands are methyl, hydroxyethyl and hydrogenated tallow or non-hydrogenated tallow.
• the compounded material was then granulated and dried in vacuo at 90 ° C. for 24 hours.
• the compounded polyamide layered silicate materials were placed on a cast film system from Dr. Collin GmbH, extruder type "3300 D30x25D", trigger type "136/350", processed into foils in the following way.
• the granules were melted in a conventional screw, 3 heat zone extruder, with a temperature profile of 250 ° C to 260 ° C.
• the melt was drawn off through a slot die with a die gap of 0.5 mm directly on a cooling roll at a take-off speed of 8 m / min and at a set temperature of 130 ° C.
• the Oxygen Transmission Rate was measured using a Mocon measuring device type "Oxtrans 100" at 23 ° C and at 0% relative Humidity and relative humidity at 85% ( “RH”. See Table 5) gemes ⁇ sen.
• the UV absorption values were determined using a Perkin-Elmer Lambda "15 UV / VIS" spectrophotometer. The measurements were carried out in a wavelength range from 200 nm to 400 nm. The light transmission was recorded in the measured wavelength range on a scale between 0% and 100%. The improvement in the UV barrier was assessed by comparing the areas under the absorption curves of the various films, experimental example III, which only contained Grivory G21 without layered silicate addition, being set as 100.
• aromatic group-containing polyamides used already have a good UV barrier effect, although these polyamides also have high transparency.
• the addition of a layered silicate to these special polyamides further increases the good UV barrier without significantly impairing the excellent transparency of these products.
• PA 6I / 6T was used as base polymer A in each case. Switching to another screw improves the film quality in Comparative Example 5 to such an extent that a film grade can be determined. A foil grade around 10 is not enough. Only by combining all of the measures according to the invention (cf. Examples 1 to 4) can the film grade be greatly improved.
• Base polymer B (Table 5):
• PA 6 / PA 6I / 6T blend was used as base polymer B.
• Comparative Example 7 the division of the base polymer B into two parts and the metering of the same at different points bring about an improvement in the film quality.
• the determination of a film grade is only possible if the screw geometry is also changed. Again, a very strong improvement in the film note is achieved only by combining all of the measures according to the invention (cf. Examples 5 to 7).
• PA MXD6 / MXDI was used as base polymer C.
• Comparative Example 11 too, an improvement in the film quality is achieved by dividing the base polymer into two parts and metering them at different points on the extruder. The determination of a foil note will but also only possible if the screw geometry is also changed. Depending on the layered silicate used, only a further change in the screw geometry and the combination of all the measures according to the invention (cf. Examples 8 to 10) achieve a strong improvement in the film grade.
• Layered silicate G montmorillonite, modification: quaternary ammonium compound with methyl, bis-hydroxyethyl, hydrogenated tallow;
• H montmorillonite, modification quaternary ammonium compound with methyl, bis-hydroxyethyl, tallow; Snails: D Dosage of the modified layered silicate in the melt not possible;
• Film grade very poor film quality: the film grade cannot be determined.
• the best film quality is achieved when a small part A (preferably 8 to 15% by weight, particularly preferably 10 to 12% by weight) of the granules of the base polymer in the Feed metered in, but the main part B is added later via a side feeder.
• the modified layered silicate preferably 2 to 8% by weight, particularly preferably 2 to 5% by weight, very particularly preferably 2.5 to 5% by weight
• All data in% by weight refer to the total of the recipe components of 100% by weight.
• the extrusion parameters (low temperature profile, high speed, high throughput) and the screw geometry are preferably selected so that a high shear is achieved.
• the speed of the screw is preferably more than 200 revolutions per minute (rpm). A speed of at least 300 rpm is particularly preferred, a speed of 400 rpm is very particularly preferred.
• the screw geometry is also important. There is a good melting of the granulate fraction A, e.g. by kneading blocks before the layered silicate is added. After adding it and before the side feeder, a good mixing effect is necessary again. After the side feeder, sufficient kneading and mixing action must be provided. Measures that increase the dwell time also have a positive effect on the result, but must not lead to excessive degradation of the base polymer.
• the screw geometries used are summarized in Table 1.
• the screw should preferably be designed in such a way that a vacuum can be applied in front of the nozzle for degassing. A pressure or vacuum of less than 200 mbar is preferred; a pressure or a vacuum of less than 50 mbar is particularly preferred.
• High throughput is also preferred.
• WP ZSK 25 twin screw extruder
• a throughput of 20 kg / h in combination with these formulations is the maximum.
• work should always be carried out in the upper quarter of the throughput and speed range of the extruder used, preferably the upper one Throughput and speed limit.
• the throughput limit is determined by the maximum possible torque at the desired low temperatures.
• temperatures set on the extruder should be chosen rather low. Temperatures that are 10 ° C to 20 ° C lower than when incorporating other fillers are preferred. In the case of amorphous base polymers, temperatures of 10 ° C. to 40 ° C., preferably 20 ° C. to 40 ° C., lower (based on the entire T-profile on the extruder) are usually useful.
• the following temperature profile was set for the processing of PA 6I / 6T, PA 6 / PA 6I / 6T - Blends and PA MXD6 / MXDI: intake 10 ° C, increasing temperature from 220 ° C to 240 ° C, nozzle temperature 240 ° C. The work was carried out at a screw speed of 400 rpm.
• the polyamide nanocomposites produced according to the invention can be processed into a wide variety of articles by means of conventional plastics processing methods, e.g. Foils, tubes, bags, bottles and containers. These can be produced either by monoextrusion or coextrusion methods. Suitable plastic processing methods Blown or flat film processes, extrusion blow molding processes, injection stretch blow molding processes, injection blow molding processes, pipe extrusion processes and laminate processes.
• Shaped bodies hollow bodies, semi-finished products, plates, pipes, etc. also with larger wall thicknesses.
• Preferred processing methods known per se include injection molding, internal gas pressure and profile extrusion methods and blow molding by means of standard extrusion, 3D extrusion and suction blow molding methods.
• Shaped bodies include, for example, cooler pipes, cooler water tanks, expansion tanks and other media (in particular media with a higher temperature) carrying pipes and containers, such as those used in the production of means of transport such as cars, airplanes, ships etc.
• the packaging articles can be in the form of monolayer or multilayer packaging, in the case of multilayer packaging the polyamide nanocomposite material can be used as an outer layer, as an intermediate layer or as an innermost layer in direct contact with the packaged product.
• Another form of the invention also relates to the combination of these polyamide nanocomposites together with a multilayer composite.
• layered silicates in a barrier layer, the barrier effect of this layer is further improved. This makes it possible to reduce the layer thickness of the barrier layer in order to achieve a specific, required barrier effect.
• the barrier material in multi-layer composites is usually the most expensive component of packaging, the entire packaging system can be made cheaper in this way.
• Another cheaper option for the packaging is the excellent UV barrier effect of the partially aromatic polyamide nanocomposites.
• the use of the expensive, special, organic UV absorbers can be reduced or eliminated entirely, which can save further costs for the required packaging system.
• Organic UV absorbers are also subject to a certain amount of migration, which can lead to problems with the food suitability of packaging materials.
• Examples of possible applications of the present invention in the packaging sector are, for example, packaging of semi-finished products and products, such as food, meat products, cheese or milk products, toothpastes, cosmetic products, beverages, paints, varnishes or cleaning agents ,
• packaging includes toothpaste tubes, tubes for cosmetic products and food, packaging for cosmetic products, personal care, cleaning agents, beverages, food products etc.
• polyamides which are called matrix polyamides
• Polyamides which contain aromatic components are suitable.
• Suitable polyamides of this type can contain PA 61 / 6T, PA 6 / PA 61 / 6T blends or copolyamides made from HMDA and / or MXDA and aliphatic and / or aromatic dicarboxylic acids.
• lactams lactam-6, -11, -12
• Packaging produced by using the method according to the invention ensures that perishable packaging goods, which are sensitive to the permeability of the packaging casings to gases, in particular to oxygen and carbon dioxide, have an extended shelf life.
• Such packaging also shows an improved barrier effect against spices and flavorings such as essential oils.
• the packaging also shows an unexpected reduction in the transmission of UV light.

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• 2003
  • 2003-01-30 KR KR1020047011764A patent/KR100909924B1/ko active IP Right Grant
  • 2003-01-30 EP EP20030700793 patent/EP1470179A1/de not_active Withdrawn
  • 2003-01-30 CN CNB038069504A patent/CN1300224C/zh not_active Expired - Fee Related
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