Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/10—Coatings without pigments
  • D21H19/14—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12
  • D21H19/16—Coatings without pigments applied in a form other than the aqueous solution defined in group D21H19/12 comprising curable or polymerisable compounds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/36—Coatings with pigments
  • D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
  • D21H19/56—Macromolecular organic compounds or oligomers thereof obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H19/60—Polyalkenylalcohols; Polyalkenylethers; Polyalkenylesters
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
  • D21H21/16—Sizing or water-repelling agents
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/10—Packing paper

Definitions

• the invention relates to a paper or cardboard packaging from mineral oil loaded, recycled paper with a barrier layer, which can be prepared by applying an aqueous polymer dispersion containing a copolymer which can be prepared by emulsion polymerization of C1 to C4 alkyl (meth) acrylates, acid monomers and optionally acrylonitrile and other monomers, wherein the glass transition temperature of the copolymer is in the range of +10 to +45 ° C.
• the barrier layer may be on one of the packaging surfaces or form one of several layers of a multilayer packaging coating.
• Cardboard packaging is usually made from recycled paper.
• the recycled paper may contain residual mineral oil from printing inks commonly used for newspaper printing. Even at room temperature, volatiles of these residues evaporate and, in the case of food packaging, beat on the box-packed foodstuffs, e.g. Noodles, grits, rice or cornflakes down. Also, most of the inner bag made of polymer films used today do not provide adequate protection. Studies by the Cantonal Laboratory of Zurich have revealed significant levels of residual oil in food packaged in recycled paper packaging.
• the volatile mineral oil constituents are predominantly health-hazardous paraffin and naphthenic hydrocarbons and aromatic hydrocarbons, in particular those having 15-25 C atoms.
• Mineral oil contamination means that the paper contains detectable amounts of volatile hydrocarbons by conventional analytical methods, in particular volatile paraffins, volatile naphthenes and / or volatile aromatic hydrocarbons having up to 25 carbon atoms. Volatile hydrocarbons are those having up to 25 C atoms, e.g. from 5 to 22 carbon atoms.
• the mineral oil load is derived from printing inks and includes volatile paraffins, volatile naphthenes and / or volatile aromatic hydrocarbons.
• the polymer dispersions to be used according to the invention are dispersions of polymers in an aqueous medium.
• This may be, for example, completely desalinated water or mixtures of water and a miscible solvent such as methanol, ethanol or tetrahydrofuran.
• a miscible solvent such as methanol, ethanol or tetrahydrofuran.
• no organic solvents are used.
• the solids contents of the dispersions are preferably from 15 to 75 wt .-%, preferably from 40 to 60 wt .-%, in particular greater than 50 wt.%.
• the solids content can be adjusted, for example, by appropriate adjustment of those used in the emulsion polymerization Amount of water and / or the amount of monomers done.
• the mean particle size of the polymer particles dispersed in the aqueous dispersion is preferably less than 400 nm, in particular less than 300 nm. Particularly preferably, the mean particle size is between 70 and 250 nm or between 80 and 150 nm.
• the average particle size is the d 50 value Understood particle size distribution, ie 50 wt .-% of the total mass of all particles have a smaller particle diameter than the d 50 value.
• the particle size distribution can be determined in a known manner with the analytical ultracentrifuge ( W. Gurchtle, Macromolecular Chemistry 185 (1984), page 1025-1039 ).
• the pH of the polymer dispersion is preferably adjusted to pH greater than 4, in particular to a pH of between 5 and 9.
• the copolymers to be used according to the invention are emulsion polymers preparable by emulsion polymerization of free-radically polymerizable monomers.
• the copolymer is formed from one or more major monomers (a) selected from the group consisting of C1 to C4 alkyl (meth) acrylates.
• the main monomers (a) are preferably at least 70% by weight, preferably at least 75% by weight, e.g. from 79.5 to 99.5 wt.%, Based on the sum of all monomers used.
• Particularly preferred main monomers (a) are selected from the group consisting of methyl acrylate, methyl methacrylate, ethyl acrylate and n-butyl acrylate.
• the copolymer is formed from one or more acid monomers (b).
• Acid monomers are ethylenically unsaturated, radically polymerizable monomers having at least one acid group, e.g. Monomers with carboxylic acid, sulfonic acid or phosphonic acid groups. Preferred are carboxylic acid groups. Called z. For example, acrylic acid, methacrylic acid, itaconic acid, maleic acid or fumaric acid.
• the acid monomers (b) are selected from acrylic acid and methacrylic acid.
• the acid monomers (b) are used at 0.1 to 5 wt.%, Preferably at 0.5 to 5 wt.%, Based on the sum of all monomers.
• the copolymer can optionally be formed as further monomer (c) to 0 to 20 wt.%, Based on the sum of all monomers, of acrylonitrile. In one embodiment of the invention, the copolymer is formed to 1-20 wt%, preferably 2-20 wt% of acrylonitrile.
• the copolymer may optionally be formed from other monomers (d) other than the monomers (a) to (c).
• the amount of further monomers (d) is 0 to 10 wt.% Or 0 to 5 wt.%, Based on the sum of all monomers. In one embodiment, 0.1 to 10 wt.% Or 0.1 to 5 wt.% Of further monomers (d) are used. In another embodiment, no further monomers other than monomers (a) to (c) are used.
• the further monomers (d) can be selected from the group consisting of C 5 -C 20 -alkyl (meth) acrylates, vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinylaromatics having up to 20 carbon atoms, ethylenically different from acrylonitrile unsaturated nitriles, vinyl halides, vinyl ethers of alcohols containing 1 to 10 carbon atoms, aliphatic Hydrocarbons having 2 to 8 carbon atoms and one or two double bonds or mixtures of these monomers.
• Examples include (meth) acrylic acid alkyl esters having a C 5 -C 10 alkyl radical, such as 2-ethylhexyl acrylate.
• mixtures of (meth) acrylic acid alkyl esters are also suitable.
• Vinyl esters of carboxylic acids having 1 to 20 carbon atoms are, for. As vinyl laurate, vinyl stearate, vinyl propionate, vinyl versatate and vinyl acetate.
• Suitable vinylaromatic compounds are vinyltoluene, ⁇ - and p-methylstyrene, ⁇ -butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene and preferably styrene.
• Example of nitriles is methacrylonitrile.
• the vinyl halides are chloro, fluoro or bromo substituted ethylenically unsaturated compounds, preferably vinyl chloride and vinylidene chloride.
• vinyl ethers are, for.
• Vinyl ether is preferably from 1 to 4 C-containing alcohols.
• hydrocarbons having 4 to 8 carbon atoms and two olefinic double bonds may be mentioned butadiene, isoprene and chloroprene.
• Preferred further monomers (d) are the C 5 - to C 10 -alkyl acrylates and -methacrylates and vinylaromatics, in particular styrene and mixtures thereof.
• Further monomers (d) are z.
• hydroxyl-containing monomers in particular C 1 -C 10 hydroxyalkyl (meth) acrylates and (meth) acrylamide.
• monomers (d) which may also be mentioned are phenyloxyethylglycol mono- (meth) acrylate, glycidyl acrylate, glycidyl methacrylate, amino (meth) acrylates such as 2-aminoethyl (meth) acrylate.
• Other monomers (d) which may also be mentioned are crosslinking monomers.
• Type and amounts of the monomers of the copolymer are adjusted so that the glass transition temperature of the emulsion polymer in the range of +10 to +45 ° C, preferably from +15 to +40 ° C.
• the glass transition temperature can be determined by differential scanning calorimetry (ASTM D 3418-08, so-called "midpoint temperature").
• the preparation of the copolymers can be carried out by emulsion polymerization, it is then an emulsion polymer.
• ionic and / or nonionic emulsifiers and / or protective colloids or stabilizers are generally used as surface-active compounds in order to assist in the dispersion of the monomers in the aqueous medium.
• Protective colloids are polymeric compounds which upon solvation bind large quantities of water and are capable of stabilizing dispersions of water-insoluble polymers. In contrast to emulsifiers, they usually do not lower the interfacial tension between polymer particles and water.
• Suitable protective colloids can be found in Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, Macromolecular Materials, Georg Thieme Verlag, Stuttgart, 1961, pages 411-420 , Suitable as protective colloids z.
• amphiphilic polymers ie polymers with hydrophobic and hydrophilic groups. They may be natural polymers such as starch or synthetic polymers.
• Suitable emulsifiers are both anionic and nonionic surfactants whose number average molecular weight is usually below 2000 g / mol or preferably below 1500 g / mol, while the number average molecular weight of the protective colloids is above 2000 g / mol, for example 2000th to 100,000 g / mol, in particular from 5000 to 50,000 g / mol.
• Anionic and nonionic emulsifiers are preferably used as surface-active substances.
• Suitable emulsifiers are, for example, ethoxylated C 8 - to C 36 fatty alcohols having a degree of ethoxylation of 3 to 50, ethoxylated mono-, di- and tri-C 4 - to C 12 -alkylphenols having a degree of ethoxylation of 3 to 50, alkali metal salts of dialkyl esters of Sulfosuccinic acid, alkali metal and ammonium salts of C 8 - to C 12 -alkyl sulfates, alkali metal and ammonium salts of C 12 - to C 18 -alkylsulfonic acids and alkali metal and ammonium salts of C 9 - to C 18 -alkylarylsulfonic acids.
• emulsifiers and / or protective colloids are used as auxiliaries for dispersing the monomers, the amounts used thereof are, for example, from 0.1 to 5% by weight, based on the monomers.
• Trade names of emulsifiers are z. Dowfax® A1, Emulan® NP 50, Dextrol® OC 50, Emulsifier 825, Emulsifier 825 S, Emulan® OG, Texapon® NSO, Nekanil® 904 S, Lumiten® I-RA, Lumiten E 3065, Lumiten® ISC , Disponil® NLS, Disponil LDBS 20, Disponil FES 77, Lutensol AT 18, Steinapol VSL, Emulphor NPS 25.
• the surfactant is usually used in amounts of 0.1 to 10 wt .-%, based on the monomers to be polymerized.
• the emulsion polymerization is generally carried out at 30 to 130, preferably 50 to 90 ° C.
• the polymerization medium may consist of water only, as well as of mixtures of water and thus miscible liquids such as methanol. Preferably, only water is used.
• the emulsion polymerization can be carried out both as a batch process and in the form of a feed process, including a stepwise or gradient procedure. Preferably, the feed process in which one submits a portion of the polymerization, heated to the polymerization, polymerized and then the rest of the polymerization, usually over several spatially separate feeds, one or more of which monomers in pure or in emulsified form, continuously or gradually supplied.
• the customary and known auxiliaries such as water-soluble initiators and regulators can be used.
• Water-soluble initiators for the emulsion polymerization are, for example, ammonium and alkali metal salts of peroxodisulfuric acid, eg. For example, sodium peroxodisulfate, hydrogen peroxide or organic peroxides, z. B. tert-butyl hydroperoxide.
• so-called reduction-oxidation (red-ox) initiator systems are so-called reduction-oxidation (red-ox) initiator systems.
• the redox initiator systems consist of at least one mostly inorganic reducing agent and one inorganic or organic oxidizing agent.
• the oxidation component is z. B.
• the reduction components are, for. B. to alkali metal salts of sulfurous acid, such as.
• alkali metal salts of sulfurous acid such as.
• the red-ox initiator systems can be used with the concomitant use of soluble metal compounds whose metallic component can occur in multiple valence states. Usual Red Ox initiator systems are z.
• the individual components eg. As the reduction component, mixtures may also be z.
• the compounds mentioned are usually used in the form of aqueous solutions, the lower concentration being determined by the amount of water acceptable in the dispersion and the upper concentration by the solubility of the compound in question in water.
• the concentration is 0.1 to 30 wt .-%, preferably 0.5 to 20 wt .-%, particularly preferably 1.0 to 10 wt .-%, based on the solution.
• the amount of initiators is generally 0.1 to 10 wt .-%, preferably 0.5 to 5 wt .-%, based on the monomers to be polymerized. It is also possible to use a plurality of different initiators in the emulsion polymerization. To remove the residual monomers, initiator is usually also added after the end of the actual emulsion polymerization.
• polymerization regulators can be used, for. B. in amounts of 0 to 0.8 parts by weight, based on 100 parts by weight of the monomers to be polymerized, whereby the molecular weight is reduced.
• Suitable z. B. Compounds having a thiol group such as tert-butyl mercaptan, mercaptoethyl propionate, 2-ethylhexyl thioglycolate, thioglycolic acid ethyl ester, mercaptoethanol, mercaptopropyltrimethoxysilane, n-dodecyl mercaptan, or tert-dodecyl mercaptan.
• regulators without a thiol group can be used, e.g. Terpinolene.
• the emulsion polymer is prepared using from 0.05 to 0.5% by weight, based on the amount of monomer, of at least one molecular weight regulator.
• the polymer dispersion used for the coating of the packagings can consist solely of the emulsion polymer dispersed in water for the use according to the invention. However, it may also contain other additives, e.g. Fillers, antiblocking agents, dyes, leveling agents or thickeners.
• the at least one copolymer is used in combination with up to 1 part by weight of platelet-shaped pigments, based on 1 part by weight of copolymer.
• platelet-shaped pigments are talc, clay or mica (mica). Preference is given to talc.
• Preferred form factors (length to thickness ratio) are greater than 10.
• the polymer dispersion forms a barrier layer after coating the substrate.
• a barrier layer is particularly present when a copolymer is used which causes a coating with the copolymer to have a permeability to gaseous n-hexane less than 50 g / m 2 d, preferably less than 10 g / m 2 d, more preferably less than 5 g / m 2 d or less than 1 g / m 2 d at 23 ° C and a weight of 20-25 g / m 2 on paper (see measuring method in the examples below).
• the content of the at least one copolymer in the dispersion used for the coating is preferably at least 1 wt .-%, in particular at least 5 wt .-% and up to 60 or up to 75 wt.%.
• the content of the at least one copolymer in the aqueous dispersion is 15 to 75% by weight, or 40 to 60% by weight.
• Preferred aqueous dispersions of the copolymers have a viscosity of 10 to 150,000 mPas, or 200 to 5000 mPas (measured with a Brookfield viscometer at 20 ° C., 20 rpm, spindle 4) at a pH of 4 and a temperature of 20 ° C. ).
• the mean particle size of the copolymer particles dispersed in the aqueous dispersion is, for example, from 0.02 to 100 ⁇ m, preferably from 0.05 to 10 ⁇ m. You can z. Example by means of optical microscopy, light scattering or freeze-fracture electron microscopy.
• the carrier substrates are coated with an aqueous dispersion of at least one of the copolymers described above.
• Suitable substrates are in particular paper and cardboard.
• the dispersions used for coating may contain other additives or adjuvants, e.g. Thickener for adjusting the rheology, wetting aids or binders.
• the application can be carried out, for example, on coating machines in such a way that the coating composition is applied to paper or board. If web-shaped materials are used, the polymer dispersion is usually applied from a trough over an applicator roll and leveled with the aid of an air brush. Other ways of applying the coating succeed, for example. with the aid of the reverse gravure method, with a spray method or with a roller blade or with other coating methods known to the person skilled in the art.
• the carrier substrate is coated on at least one side, i. it can be coated on one side or on both sides.
• Preferred application methods for paper and board are curtain coating, air knife, bar brushing or knife coating.
• Preferred application methods for film coating are doctor blade, wire bar, air brush, reverse roll coating method, countergraduate coating, pouring head or die.
• the amounts applied to the sheet-like materials are preferably 1 to 10 g (polymer, solids) per m 2 , preferably 2 to 7 g / m 2 for films, or preferably 5 to 30 g / m 2 for paper or board.
• the solvent or water is evaporated.
• the material can pass through a dryer channel, which can be equipped with an infrared irradiation device. Thereafter, the coated and dried material is passed over a cooling roll and finally wound up.
• the thickness of the dried coating is preferably at least 1 ⁇ m, in particular 1 to 50 ⁇ m, particularly preferably 2 to 30 ⁇ m or 5 to 30 ⁇ m.
• the barrier layer may be located on at least one of the packaging surfaces. It may also form at least one of several layers of a multilayer packaging coating.
• the barrier coating may be applied directly to a surface of the substrate, however, other layers may be present between the substrate and the barrier coating, e.g. B. primer layers, other barrier layers or colored or black and white ink layers.
• the barrier layer is preferably located on the inner, the packaged goods facing side of the package.
• the inner bag is preferably made of a polymer film.
• the material of the inner bag is preferably selected from polyolefins, preferably polyethylene or oriented polypropylene, which polyethylene may have been produced by both high pressure and low pressure polymerization of ethylene.
• the carrier film may be previously subjected to a corona treatment.
• suitable carrier films are, for example, films of polyester, such as polyethylene terephthalate, films of polyamide, polystyrene and polyvinyl chloride.
• the support material is biodegradable films, e.g.
• Suitable copolyesters are e.g. formed from alkanediols, in particular C 2 to C 8 alkanediols, e.g. 1,4-butanediol, from aliphatic dicarboxylic acids, in particular C 2 to C 8 dicarboxylic acids, such as e.g. Adipic acid and from aromatic dicarboxylic acids such as e.g. Terephthalic acid.
• the thickness of the carrier films is generally in the range of 10 to 200 ⁇ m.
• the coated substrates In order to obtain special surface or coating properties of the films and packaging materials, for example a good printability, even better barrier or blocking behavior, good water resistance, it may be advantageous to coat the coated substrates with cover layers which additionally impart these desired properties or the barrier coating subject to a corona treatment.
• the substrates precoated according to the invention show good overcoatability. It may be overcoated again according to a method mentioned above or in a continuous process without intermediate winding and unwinding e.g. the film or paper are coated at the same time several times, e.g. using a curtain coater.
• the barrier layer according to the invention is located inside the system, the surface properties are then determined by the cover layer.
• the cover layer has good adhesion to the barrier layer.
• the invention also provides a process for producing a packaging, wherein a composition in the form of an aqueous polymer dispersion described above is provided and applied to a packaging substrate and dried, wherein the aqueous polymer dispersion contains at least one of the above-described copolymers.
• the invention also provides the use of an aqueous polymer dispersion comprising at least one of the copolymers described above for producing a barrier layer against volatile mineral oil constituents, in particular for producing packaging, in particular packaging for foodstuffs.
• coated substrates according to the invention show an excellent barrier effect against volatile mineral oil constituents.
• the coated substrates can be used as such as packaging.
• the coatings have very good mechanical properties, and show e.g. good block behavior.
• the indication of a content refers to the content in aqueous solution or dispersion.
• the experimental system was stored at 60 ° C and examined by periodically cutting a strip of the acceptor sheet, extracting with n-hexane 2h / 25 ° C, and measuring the content of 15-25 carbon number mineral oil ingredients by on-line HPLC-GC. It was the breakthrough time for the breakthrough of mineral oil components by the barrier material certainly.
• the breakthrough time is the time after which mineral oil constituents above the detection limit are detected for the first time in the extract.
• Table 1 Barrier effects of certain polymers polymer Test fat / oil fat barrier mineral oil barrier aromatic / aliphatic, amorphous polyester-polyurethane DINP + no penetration - breakthrough ⁇ 4d aliphatic, partially crystalline polyester-polyurethane DINP + no penetration - breakthrough ⁇ 4d MMA / MA / AS Copolymer Tg about 50 ° C DINP oleic acid - Partially greased area + no penetration aromatic / aliphatic, partially crystalline polyester-polyurethane DINP + no penetration - breakthrough ⁇ 4d polyethylene film DINP oleic acid + no penetration - breakthrough ⁇ 1d S / nBA / AN / AS copolymer, Tg 5 ° C oleic acid + no penetration - breakthrough ⁇ 4d S / butadiene / AS copolymer, Tg 20 ° C oleic acid - Fully greased - no hexane barrier (test 2)

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• Paper (AREA)
• Laminated Bodies (AREA)
• Wrappers (AREA)
• Paints Or Removers (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
• Packages (AREA)

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Applications Claiming Priority (3)

Publications (2)

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• 2012
  • 2012-05-23 EP EP12722163.8A patent/EP2714990B1/de active Active
  • 2012-05-23 MX MX2013013615A patent/MX2013013615A/es unknown
  • 2012-05-23 TR TR2018/15930T patent/TR201815930T4/tr unknown
  • 2012-05-23 ES ES12722163T patent/ES2698846T3/es active Active
  • 2012-05-23 BR BR112013030513A patent/BR112013030513A2/pt not_active Application Discontinuation
  • 2012-05-23 PT PT12722163T patent/PT2714990T/pt unknown
  • 2012-05-23 CA CA2835273A patent/CA2835273A1/en not_active Abandoned
  • 2012-05-23 CN CN201280024647.7A patent/CN103547735B/zh active Active
  • 2012-05-23 RU RU2013158460/05A patent/RU2013158460A/ru not_active Application Discontinuation
  • 2012-05-23 JP JP2014513122A patent/JP6214525B2/ja not_active Expired - Fee Related
  • 2012-05-23 PL PL12722163T patent/PL2714990T3/pl unknown
  • 2012-05-23 AU AU2012264927A patent/AU2012264927A1/en not_active Abandoned
  • 2012-05-23 WO PCT/EP2012/059551 patent/WO2012163749A2/de active Application Filing
• 2013
  • 2013-12-20 ZA ZA2013/09722A patent/ZA201309722B/en unknown

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