Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/10—Materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K3/1006—Materials in mouldable or extrudable form for sealing or packing joints or covers characterised by the chemical nature of one of its constituents
  • C09K3/1021—Polyurethanes or derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/10—Materials in mouldable or extrudable form for sealing or packing joints or covers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/10—Materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2003/1087—Materials or components characterised by specific uses
  • C09K2003/109—Crown caps
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2200/02—Inorganic compounds
  • C09K2200/0204—Elements
  • C09K2200/0213—Metals
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2200/06—Macromolecular organic compounds, e.g. prepolymers
  • C09K2200/0615—Macromolecular organic compounds, e.g. prepolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C09K2200/0617—Polyalkenes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2200/06—Macromolecular organic compounds, e.g. prepolymers
  • C09K2200/0615—Macromolecular organic compounds, e.g. prepolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C09K2200/0617—Polyalkenes
  • C09K2200/062—Polyethylene
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2200/06—Macromolecular organic compounds, e.g. prepolymers
  • C09K2200/0615—Macromolecular organic compounds, e.g. prepolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C09K2200/0622—Polyvinylalcohols, polyvinylacetates
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2200/06—Macromolecular organic compounds, e.g. prepolymers
  • C09K2200/0615—Macromolecular organic compounds, e.g. prepolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C09K2200/0632—Polystyrenes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
  • C09K2200/06—Macromolecular organic compounds, e.g. prepolymers
  • C09K2200/0642—Copolymers containing at least three different monomers

Definitions

• the present invention relates to a method for producing metallic closures for tightly closing packaging containers, in which a sealing compound is applied to the inside of the closures, which are punched out of a metal sheet coated with at least one plastic film.
• the invention also relates to closures for packaging containers in which a sealing compound has been applied to the inside of the closures, as well as packaging containers with these closures.
• the purpose of the various packaging materials is to hermetically seal the contents from the environmental influences, even under extreme conditions such as those e.g. prevail in the heat sterilization of food. In order to isolate the filling
• Lids and closures with which the packaging container is closed are introduced with suitable sealing compounds.
• sealants made of plasticized PVC plastisols are usually used for closures and lids of packaging made of glass and metal, as are described in the case of closures for glasses, for example in DE-AS 2003693.
• the PVC plastisols used as sealing compound generally consist of a paste-formable polyvinyl chloride, which is characterized in particular by a defined swelling capacity in the plasticizer, one or more plasticizers and, if appropriate, fillers, stabilizers, pigments and polyvinyl chloride Processing aids.
• plasticizer-containing PVC plastisol The formulation of plasticizer-containing PVC plastisol, its production and processing is largely in K. Weinmann, coating with lacquers and plastics, 1967, publisher W.A. Colomb, Stuttgart.
• PVC granules in suspension form are also used in sealing compounds. It is known that in the case of such PVC sealing aids, under the influence of the filling goods, in particular by greasy and oily substances and under thermal stress (pasteurization, sterilization), there is basically a migration of plasticizer from the sealing compound and also a dissolving and swelling of the sealing compound cannot be prevented in the case of fillings containing solvents. The size of the plasticizer migration can exceed current food law regulations that are currently under discussion. Furthermore, the migration of plasticizer may cause a loss of vacuum in pasteurized and sterilized packaging and a loss of solvents due to an increased gas permeability in the case of technical packaging.
• sealing compounds based on polyurethane are also known.
• sealing compounds based on polyurethane are also known.
• sealing compounds based on polyurethane are also known.
• sealing compounds for packaging containers which contain - optionally blocked - polyisocyanate prepolymers and carbon dioxide-blocked amines as crosslinking agents.
• Sealants are known from DE-OS 1957827 and DE-OS 2203730, which contain hydroxyl-containing polymers and polyisocyanates or blocked prepolymers and an activator with hydroxyl-containing polymers and aluminum silicate compounds.
• Sealing compounds for closures of packaging ters based on di- and polyisocyanates and di- and polyamines are known from DE-OS 4025327 and DE-OS 3905545.
• a disadvantage of the sealing compounds described above is that they are applied to a metal sheet which has to be coated beforehand with a so-called adhesive lacquer. This adhesive varnish ensures the adhesion between the metal sheet and the sealing compounds and protects the metal sheet from occurring corrosion.
• Solvent-based paints based on epoxy-phenolic resin are usually used as adhesive paints,
• WO 90/9280 discloses laminates made of co-extruded plastic films and metal sheets, which can be formed as closures, for example lids, of packaging containers. A sealant based on a PVC plastisol is applied to the closures, ie to the foils laminated onto the metal sheet.
• the coextruded films used according to WO 90/9280 consist, for example, of an acid-modified polyolefin layer and maleic anhydride-vinyl acetate-ethylene terpolyers, polyvinylidene chloride or non-plasticized PVC.
• a disadvantage of the closures produced in accordance with WO 90/9280 is that in the sealing compounds used based on PVC plastisols under the influence of the filling goods, in particular by greasy and oily substances and under thermal stress (pasteurization, sterilization) sation) a migration of plasticizer from the sealant as well as a loosening and swelling of the sealant cannot be prevented in the case of fillings containing solvents.
• the size of the plasticizer migration can exceed currently valid food law regulations that are under discussion.
• the plasticizer migration may result in a vacuum loss in pasteurized and sterilized packaging and a loss in solvents due to an increased gas permeability in the case of technical packaging.
• Another disadvantage is that the disposal of waste containing PVC is becoming increasingly problematic and costly.
• the present invention was therefore based on the object of an environmentally friendly, ie. H. to provide a solvent-free method for the production of closures for tightly closing packaging containers, in which the sealants applied to the inside of the closures do not contain any plasticizers compared to the sealants commonly used based on PVC plastisols Have migration, ie the sealants should be halogen-free and have the lowest possible migration rate compared to solvent-based and / or fat-containing products. In addition, the sealing compounds should also have the lowest possible migration of other components of the sealing material into the
• the sealing compound should be stable, in particular under the conditions of sterilization and pasteurization, and should not migrate into the contents.
• the adhesive varnish normally used in the closures should be replaced by solvent-free single or multi-layer plastic films.
• the adhesion between the sealant and the metal sheet should be excellent.
• the method for producing the closures should be as simple as possible and with only a slight be feasible.
• this object is achieved by a method for producing metallic closures for tightly closing packaging containers, in which a sealant is applied to the inside of the closures, which are punched from a metal sheet coated with at least one plastic film, which is characterized in this way that a halogen-free, solvent-free sealing compound is melted and applied to the inside of the closures.
• the sealants used are produced by mixing the individual components of the sealants and then dispersing the insoluble constituents with the dispersing units customary in the plastics industry.
• the sealants produced in this way generally have Shore A hardnesses (DIN 53 505) between 20 and 90, preferably between 25 and 85.
• the sealing compounds used are preferably extruded and applied to the inside of the closures.
• the sealing compounds used in the method according to the invention are processed in machines known for such processing purposes, that is to say, for example, in machines for internally coating crown caps.
• the sealing compounds usually first enter an extruder, in which they are homogenized with thorough kneading. They leave the outlet opening of the extruder as plastic strands which are immediately cut into individual lumps behind the outlet opening. These cut strands, each weighing about 150-400 mg, are transferred to the inside of the metallic closures in the molten state.
• a possibly cooled form stamp the still plastic polymer mass distributed on the inner surface of the closures.
• the closures thus produced for packaging containers are ready for use after the sealing compounds have solidified and can be stored until use.
• the metallic closures are punched from metal-plastic film laminates.
• the sealing compounds are then applied to these metal-plastic film laminates, these being applied to the plastic films laminated onto the metal sheet.
• care must be taken that the plastic films are selected in such a way that they ensure good adhesion to the sealing compound used.
• the adhesion of the plastic film to the metal sheet must of course also be excellent.
• Metal sheets with a thickness of 0.04-1 mm are suitable as metal sheets. They can consist of black plate, tin plate, aluminum and various iron alloys, which may be provided with a passivation layer based on nickel, chrome and zinc compounds.
• the metal sheets are coated with one or more thermoplastic plastic films.
• the plastic films used are manufactured, for example, by extrusion (for example blowing, chill-roll, etc.) from granules of the plastics.
• the plastic films can also be composite films and films (composite film and composite films), which are obtained, for example, by extruding various thermoplastic materials together Plastics.
• a solvent-based or aqueous adhesive is used, or an adhesion-promoting plastic (adhesion promoter) is coextruded together with the plastic that is to be used for the plastic film.
• an adhesion-promoting plastic adhesion promoter
• the bonding of a plastic film to a metal sheet by means of an adhesive is known, for example, from EP-A-199228.
• the polymers used as adhesion promoters or adhesives for producing the metal-plastic film laminates can be copolymers, terpolymers, graft copolymers and ionomers with the proviso that they contain carboxyl or anhydride groups or groups which can be hydrolyzed to carboxyl groups are.
• Suitable copolymers or terpolymers can be prepared by copolymerizing, for example, ethylene or propylene with ⁇ , 3-ethylenically unsaturated carboxylic acids, such as Acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and fumaric acid, the corresponding anhydrides or the corresponding esters or half-esters with 1 - 8 carbon atoms in the alcohol residue.
• carboxylic acids such as Acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid and fumaric acid, the corresponding anhydrides or the corresponding esters or half-esters with 1 - 8 carbon atoms in the alcohol residue.
• the corresponding salts of the carboxylic acids listed can also be used.
• the carboxylic acids and their anhydrides are preferably used.
• the amounts of the monomers used are chosen so that the resulting polymer is one
• Polymers suitable for producing the adhesion promoter layer or the adhesive layer are also graft copolymers which can be produced by grafting at least one polymer from the group of the polyolefins with up to 10% by weight, based on the total weight of the monomers, of at least one monomer from the group of the ⁇ , / 3-ethylenically unsaturated carboxylic acids, their anhydrides, their esters or salts in the presence or absence of peroxides.
• the ionomers used as an adhesion promoter layer or adhesive layer can be prepared by the copolymerization of ethylene or propylene and possibly further monomers with salts, ⁇ , 3-ethylenically unsaturated carboxylic acids already described above, or by partial neutralization of the carboxylic acid-containing Co already described above -, Ter and graft polymers with salts, oxides and hydroxides of sodium, potassium, lithium, magnesium, calcium, zinc and ammonium.
• Suitable adhesion promoters are described, for example, in DE-OS 3929942.
• the plastics which are suitable for producing the plastic film which is laminated onto the metal sheet are preferably polyolefins, polyesters, polyamides and polyurethanes. Films and films made from these plastics are known and are available in a large number on the market.
• Low density polyethylene (PE-LD), medium density (PE-MD), high density (PE-HD), linear low and linear very low density polyethylene (PE-LLD, PE-VLD), polypropylene are suitable for the production of the plastic films , their copolymers with ethylene and other monomers, and the copolymers of ethylene and propylene with one or more comonomers from the group of the vinyl esters, vinyl alkyl ethers, unsaturated mono- and dicarboxylic acids, their salts, anhydrides and esters.
• polyolefins are commercially available, for example, under the following brand names: Escorene, Lupolen, Lotader, Laqctene, Orevac, Dowlex, Pri acor, Surlyn, Admer, Sclair, Stamylan.
• polyamide plastics examples include polyamide 6 (polyamide, made from .amino-caproic acid), polyamide 6.6 (polyamide, made from hexamethylene diamine and sebacic acid), polyamide 66.6 (mixed polyamide, made from polyamide 6 and polyamide 6.6), polyamide 11 (polyamide, made from lu-aminoundecanoic acid) and polyamide 12 (polyamide, made from D-aminolauric acid or from lauryl lactam). Examples of commercial products are Grilon, Sniamid and Ultramid.
• polyester plastics are polyethylene terephthalate and polybutylene terephthalate as well as other polyesters based on terephthalic acid, isophthalic acid and phthalic acid and various polyols, such as e.g. Polyethylene glycol and Polytetra ethlenglycole different degrees of polymerization.
• suitable commercial products are Hostaphan, Melinex and Hostadur.
• closures are punched from the metal-plastic film laminates described above, on the inside of which the sealing compound is applied in a second step.
• the procedure is such that the halogen-free, solvent-free sealing compounds are melted and onto the inside of the closures, ie onto the thermoplastic plastic films which are glued to the metal sheet are applied.
• sealing compounds are the polymer compounds known from DE-OS-3620690.
• a method according to the invention is preferred in which the plastic film brought into contact with the sealing compound essentially consists of ethylene homopolymers, ethylene copolymers or polyesters and the sealing compound
• Suitable ethylene homopolymers are the above-described high, medium and low density polyethylenes which are available, for example, on the market under the trade name LupolenS '(BASF AG). Suitable polyethylenes are, for example, known from DE-A-25 24 274, DE-A-26 17 411, DE-A-34 04 744, DE-A-34 44 096, DE-A-38 44 047 and US-PS 3,969,434.
• Suitable ethylene copolymers are copolymers of ethylene with up to 15% by weight, based on the total weight of monomers, of ⁇ -01efins.
• Suitable comonomers are ⁇ , 3-ethylenically unsaturated carboxylic acids, their anhydrides, their esters or half-esters with 1-10 carbon atoms in the alcohol radical, vinyl acetate and vinyl propionate.
• thermoplastic plastic films Suitable polyesters have already been described in the description of the thermoplastic plastic films.
• the ethylene and / or ethylene copolymers used in the sealing compound can be the same ones which have already been described above for the production of the plastic film. This also come
• Ethylene graft copolymers in question which, based on the graft base composed of ethylene homopolymers and / or copolymers, contain 0.01 to 0.5% by weight of an ⁇ , 3-ethylenically unsaturated carboxylic acid and / or an ⁇ , 3-ethylenically unsaturated comonomer .
• Such graft polymers are described, for example, in DE-A-36 39 564 and DE-A-36 39 566.
• the sealing compounds styrene-butadiene-styrene block copolymers SBS rubber
• SIS rubber styrene-isoprene-styrene block copolymers
• Suitable SBS rubbers and SIS rubbers are described, for example, in DE-A-1692059 and US Pat 3,779,965. These are block copolymers of the ABA type which contain polystyrene as block A and polybutadiene or polyisoprene as block B.
• Suitable SBS rubbers consist, for example, of 30-60% polystyrene end segments and 70-40% central segments, selected from polybutadiene or polyisoprene.
• Suitable styrene-butadiene-styrene block copolymers and styrene-butadiene copolymers are available, for example, under the trade name Finaprene (Fina).
• Ethylene-vinyl acetate copolymers are used as component c). A large number of these are commercially available and can be obtained, for example, under the trade name Escorene (Exxon Chemicals).
• component a), 20-35% by weight of component b) and 20-40% by weight of component c) are particularly preferred, the sum of the parts by weight of components a), b) and c) 100% by weight is used.
• a method according to the invention for producing closures is particularly preferred, in which the plastic film brought into contact with the sealing compound consists essentially of propylene homopolymers, propylene copolymers or propylene block copolymers and the sealing compound applied thereon
• Polypropylenes and the polypropylenes used for the production of component a) of the sealing compounds can be the same or different; these are commercially available propylene homopolymers, propylene random copolymers and propylene block copolymers, which are available, for example, under the trade name Novolerr ⁇ (BASF AG). Such polypropylene are described, for example, in DE-A-37 30 022.
• component a 20-40% by weight of component a), 20-35% by weight of component b) and 20-40% by weight of component c) are particularly preferred, in each case based on the sum of the parts by weight of a ), b) and c) used.
• a method according to the invention is also preferred, in which the plastic film brought into contact with the sealant consists essentially of propylene copolymers, propylene copolymers or propylene block copolymers and the sealant applied thereon a) 0-100% by weight of ethylene homo- and / or ethylene copolymers and / or ethylene graft copolymers,
• An acid-modified polypropylene is used as component d), which can be prepared, for example, by copolymerizing propylene with ⁇ ,? -Ethylenically unsaturated carboxylic acids, the corresponding anhydrides or the corresponding esters or half-esters with 1-8 carbon atoms in the alcohol radical.
• Suitable carboxylic acids or their anhydrides are acrylic acid, methacrylic acid, crotonic acid, itaconic acid, aconitic acid, maleic acid, maleic anhydride, citraconic acid or their anhydride.
• Suitable copolymerizable esters are esters of ⁇ ,,-ethylenically unsaturated carboxylic acids having 1 to 8 carbon atoms in the alcohol radical, and the acid concentration is usually in the range from 5 to 15%.
• Acid-modified polypropylenes and processes for their preparation are described, for example, in EP-A-312302 ben.
• Further suitable acid-modified polypropylenes are propylene graft copolymers which can be prepared by grafting ethylenically unsaturated carboxylic acids or their anhydrides, such as maleic anhydride, onto polypropylene in conventional mixers or extruders.
• the monomers to be grafted are generally used in a concentration range of 0.01-0.5% by weight, based on the polymer mixture.
• Polypropylenes grafted with ethylenically unsaturated carboxylic acids or carboxylic acid anhydrides are described, for example, in EP-A-385645, US Pat. No. 4,957,820, US Pat. No. 4,980,210, EP-A-312306 and DE-A-36 39 564.
• the base polypropylenes onto which grafting is carried out are customary propylene homopolymers, propylene-random-co- ⁇ polymers, propylene-block copolymers or propylene-random block copolymers.
• Propylene random copolymers are to be understood as meaning statistical copolymers of propylene with about 1 to 10% by weight of comonomers.
• Suitable comonomers are C, - to C 12 ⁇ ⁇ ⁇ monoolefins.
• 20 to 40% by weight a), 20 to 35% by weight b), 20 to 40% by weight c) and 2 to 5% by weight d) are particularly preferred, in each case based on the sum of the parts by weight of components a), b), c) and d) used.
• Plastic film used a polyurethane film, in which case a mass of sealant applied thereon
• thermoplastic polyurethane a) 0-100% by weight of thermoplastic polyurethane, b) 0 to 75% by weight of styrene-butadiene-styrene block polymers and / or styrene-butadiene copolymers and / or styrene-isoprene-styrene block copolymers and / or styrene-isoprene copolymers,
• thermoplastic polyurethane plastics used to produce the polyurethane film and to produce component a) are commercially available. They are preferably produced by chain extension of prepolymers having isocyanate groups. These prepolymers containing isocyanate groups are prepared by reacting polyols with a hydroxyl number of 10-1800, preferably 50-1200 mg KOH / g, with excess polyisocyanates at temperatures of up to 150 ° C. in organic solvents. The polyols used to prepare the prepolymers can be of low molecular weight and / or high molecular weight.
• a high proportion of a predominantly linear polyol with a preferred OH number of 30-150 mg KOH / g should be added.
• Up to 97% by weight of the total polyol can consist of saturated and unsaturated polyesters and / or polyethers.
• the selected polyether diols should not introduce excessive amounts of ether groups.
• Polyester diols are obtained by esterification of organic dicarboxylic acids or their
• Anhydrides made with organic diols or deviated from a hydroxycarboxylic acid or a lactone can be used to produce branched polyester polyols.
• polyols or polycarboxylic acids with a higher valency can be used to a small extent.
• Aliphatic, cycloaliphatic and / or aromatic polyisocyanates with at least 2 isocyanate groups per molecule are used as typical multifunctional isocyanates.
• the polyisocyanate component used to form the prepolymer can also contain a proportion of higher quality polyisocyanates.
• Products which have been found to be useful as triisocyanates are those which result from trimerization or oligomerization of diisocyanates or from the reaction of diisocyanates with compounds containing polyfunctional OH or NH groups.
• the isocyanate groups still present in the prepolymer are reacted with a modifier. This reaction leads in particular to a further linkage and an increase in the molecular weight.
• Preferably used as modifiers for the reaction with the prepolymer are di-, particularly preferably tri- and / or polyols.
• the polyolefins used as component d) are, for example, ethylene homopolymers, propylene homopolymers, ethylene copolymers, propylene copolymers, propylene block copolymers, ethylene block copolymers, propylene graft copolymer polymers and ethylene graft polymers.
• sealants used in the process according to the invention preferably contain up to 15% by weight, based on the total weight of the finished products Sealant, paraffinic oils, for example refined, essentially paraffinic white oils according to DAB 8 or DAB 9.
• the sealants used may contain up to 25% by weight, based on the total weight of the sealants, pigments and / fillers, for example titanium dioxide, synthetic iron oxides, organic pigments, for example phthalocyanines, tartrazines, ultramarine blue, pigment yellow 83 , Pigment orange 43, pigment orange 5, pigment red 4 and magnesium and aluminum silicates, amorphous and pyrogenic silicas, barium sulfate, carbon black, talc, kaolin and chalk.
• pigments and / fillers for example titanium dioxide, synthetic iron oxides, organic pigments, for example phthalocyanines, tartrazines, ultramarine blue, pigment yellow 83 , Pigment orange 43, pigment orange 5, pigment red 4 and magnesium and aluminum silicates, amorphous and pyrogenic silicas, barium sulfate, carbon black, talc, kaolin and chalk.
• sealants can still up to 8
• auxiliaries and additives based on the total weight of the finished sealants.
• auxiliaries and additives examples of this are lubricants for setting the correct torque values for closures that have to be screwed on or unscrewed.
• Suitable lubricants are fatty acids such as stearic and oleic acid, silicone oils such as dimethylpolysiloxane and methylhydrogenpolysiloxane.
• Further examples are waxes and silicas to achieve certain flow behavior and, in the case of foamed sealants, blowing agents, e.g. Azodicarbonamides or sulfohydrates.
• blowing agents e.g. Azodicarbonamides or sulfohydrates.
• Other examples are solid acid esters and fatty acid amides, e.g. Erucic acid amide.
• the sealing compounds used according to the present invention are melted and homogenized in an extruder.
• the sealing compounds leave the outlet opening of the extruder as plastic strands which are immediately cut into individual strands behind the outlet opening. These cut strands are still in a plastic state on the Applied on the inside of the punched closures.
• the present invention also relates to packaging containers with a metallic closure, the closure being produced by the method according to the invention.
• the closure to be coated with the sealing compound is understood to mean all parts of the packaging material which are connected to the body of the packaging, e.g. Bottle caps, e.g. in the case of beer, fruit juice and lemonade bottles, metallic closures for bottles and glasses as well as other metallic closures for cans, buckets, barrels, etc., which are common in the packaging industry.
• Bottle caps e.g. in the case of beer, fruit juice and lemonade bottles
• metallic closures for bottles and glasses as well as other metallic closures for cans, buckets, barrels, etc.
• cans e.g.
• a closures e.g. in the case of beer, fruit juice and lemonade bottles
• metallic closures for bottles and glasses as well as other metallic closures for cans, buckets, barrels, etc.
• cans e.g.
• cam twist closures e.g. in the case of beer, fruit juice and lemonade bottles
• CRIMP closures e.g. in the case of beer, fruit
• the closures produced by the process according to the invention have the particular advantage that the sealing compounds are halogen-free compared to the conventional PVC sealing aids, have no plasticizer migration and good resistance to solvents and chemicals, good resistance under the conditions of Pasteurization and sterilization as well as good adhesion to the substrates coated with the plastic films.
• the method according to the invention is particularly advantageous from an environmental point of view, since the sealing compounds contain no harmful substances, in particular no halogen-containing constituents and no low-molecular-weight plasticizers containing ester groups, and it is a largely solvent-free process for producing closures of packaging containers.
• the fact that the closures are punched out of metal-plastic film laminates means that the solvent-based adhesive lacquer that is usually used can be dispensed with.
• the thermoplastic plastic films provide excellent protection for the metal sheet used against corrosion.
• the fact that it is a solvent-free process for the manufacture of closures of packaging containers means that complex processes for hardening and exhaust air purification are not necessary.
• a sealing compound is produced from the following components by mixing, dispersing and extruding:
• crown cork punch type PTC27 manufacturer Sacmi, I ola, Italy, sheets laminated on one side and on both sides with a polypropylene film are processed to crown corks. Ready-to-use crown caps are manufactured with the following parameters on a system for introducing the sealant, manufacturer Sacmi, Imola, Italy, type PM 1200 and 250:
• the crown caps show good adhesion between the metal sheet and the sealing compound in laboratory tests.
• the sealing compounds have good resistance under pasteurization and sterilization conditions.
• one-sided and two-sided aluminum sheet coated with polypropylene hoopolymer are manufactured using rotary locks and in a system for introducing the
• the screw caps produced show excellent tightness, the adhesion between the aluminum sheet and the sealing compound is excellent. The resistance under pasteurization and sterilization conditions is good.
• a sealant is prepared from 32.0 parts of an SBS rubber (Finaprene 417, Fina), 6 parts of white oil DAB 9, 30 parts of an ethylene-vinyl acetate copolymer, 30 parts of a polyethylene homopoly resin, 0.8 parts Titanium dioxide, 1.0 part of a fatty acid ester and 0.2 part of erucic acid amide.
• Crown caps are punched from sheet metal coated with polyethylene homopolymer, as described in Example 1, and the sealing compound is introduced. The finished crown caps have a very good seal and an excellent adhesion between the sheet and the sealing compound.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
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• Organic Chemistry (AREA)
• Laminated Bodies (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Sealing Material Composition (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 1992
  • 1992-09-08 DE DE19924229923 patent/DE4229923A1/de not_active Withdrawn
• 1993
  • 1993-09-01 BR BR9307016A patent/BR9307016A/pt not_active Application Discontinuation
  • 1993-09-01 WO PCT/EP1993/002359 patent/WO1994005739A1/de not_active Application Discontinuation
  • 1993-09-01 EP EP93920689A patent/EP0663940A1/de not_active Withdrawn
  • 1993-09-01 CA CA002144054A patent/CA2144054A1/en not_active Abandoned
• 1995
  • 1995-03-07 NO NO950875A patent/NO950875D0/no unknown

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