Dispersion useful in heat-sealable coating systems suitable for the sealing of aluminum against aluminum

Abstract

The present invention is directed to a film-forming dispersion, comprising a polyester or polyester mixture as polymer type A, a poly methyl methacrylate as polymer type B, optionally a graft copolymer of polymer type A and polymer type B as polymer type AB, a polyolefin or a polyolefin mixture as polymer type C, and a graft copolymer as polymer type CD, composed of polymer type C and polymer type D, polymer type D comprising units derived from methyl methacrylate and butyl methacrylate as monomers, said dispersion comprises of from 35 % to 65 % by weight of a solvent mixture comprising ethyl acetate, propyl acetate, heptane, and iso-octane or t-butyl acetate, based on the total weight of the dispersion, to a process for the sealing of various types of substrates, characterized in that a foil is coated with a coating system comprising the film-forming dispersion and to a heat-sealable coating system suitable for the sealing of various types of substrates, comprising the film-forming dispersion.

Description

[0001] 202400146 Foreign Filing 1

[0002] Dispersion useful in heat-sealable coating systems suitable for the sealing of aluminum against aluminum

[0003] Field of the invention

[0004] The present invention is directed to a film-forming dispersion, comprising a polyester or polyester mixture as polymer type A, a poly methyl methacrylate as polymer type B, optionally a graft copolymer of polymer type A and polymer type B as polymer type AB, a polyolefin or a polyolefin mixture as polymer type C, and a graft copolymer as polymer type CD, composed of polymer type C and polymer type D, polymer type D comprising units derived from methyl methacrylate and butyl methacrylate as monomers, said dispersion comprises of from 35 % to 65 % by weight of a solvent mixture comprising ethyl acetate, propyl acetate, heptane, and iso-octane ort-butyl acetate, based on the total weight of the dispersion, to a process for the sealing of various types of substrates, characterized in that a foil is coated with a coating system comprising the film-forming dispersion and to a heat-sealable coating system suitable for the sealing of various types of substrates, comprising the film-forming dispersion.

[0005] Prior art

[0006] Traditionally aluminum lids are used for closure of plastic containers in food technology, in particular in the case of dairy products, examples being yoghurt pots. When these lids are used for closure, they have a sealable coating which at the same time provides the aroma barrier for the food with respect to the foil material.

[0007] EP 1 366128 B1 describes a hot sealing system used to coat an aluminum foil which is sealed to a plastic selected from the group of the following plastics: polypropylene, polyethylene, polystyrene, polyester or polyvinylchloride. The hot sealing system comprised of an olefin polymer or of an olefin polymer A, of a methacrylate polymer B, of a graft polymer A-X consisting of the above-mentioned constituents and of a solvent or solvent mixture. The hot sealing system is characterized by having a high thermal stability and short sealing times. As solvent mixture a mixture comprising ethyl acetate, isooctane, and propyl acetate is used.

[0008] EP 1 891 174 B1 describes a heat-sealing system consisting of an olefin polymer or olefin copolymer A, a methacrylate copolymer B, a graft polymer AB that is composed of the aforementioned components, a polyester C and an optional polymer D or an optional polymer blend DA, in addition to a solvent or solvent mixture L. The heat-sealing system is characterized by a high heat resistance, excellent barrier properties and short sealing times in relation to various plastics and aluminum foil or PET film. As solvent mixture a mixture comprising ethyl acetate, iso-octane, and propyl acetate is used. With this heat-sealing system an aluminum foil or a polyester film can be coated and is then sealed to a plastic selected from the group of the plastics polypropylene, polyethylene, polystyrene, polyester and polyvinyl chloride.

[0009] EP 1 989258 B1 describes a heat-sealable coating system suitable for the sealing of various types of substrate and comprising a film-forming dispersion, characterized in that a polymer type A is present and is a polyester or a polyester mixture, a polymer type B is present and is a (meth)acrylate homo- or / and copolymer, containing standard methacrylates and / or standard acrylates, and a polymer type AB is202400146 Foreign Filing 2

[0010] present and is a graft copolymer composed of polymer type A and polymer type B, and if appropriate a polymer type C is present and is an olefin polymer or is an olefin copolymer, and a polymer type CB is present and is a graft polymer composed of polymer type C and polymer type B, and also if appropriate a polymer type D and / or a polymer type DA is present. As solvent mixture a mixture comprising ethyl acetate, iso-octane, and propyl acetate is used. With this heat-sealing system an aluminum foil or a polyester film can be coated and is then sealed to a plastic selected from the group of the plastics polypropylene, polyethylene, polystyrene, polyester and polyvinyl chloride.

[0011] Coffee brewing might be seen as to be an extraction process of daily practice. In our day very often special coffee systems or hot beverage systems are used as special coffeemaker. The extraction of coffee is carried out in a special disposable capsule-shaped-brewing-container. Each brewing container has one serving of coffee, tea, milk, and / or other ingredients in it. This makes it easy to make coffee, espresso, etc. The process is very clean and convenient.

[0012] In such a closed disposable brewing container the capsule body and the lidding foil (antagonist foil) are connected by means of a heat-seal lacquer which often provides also the inner coating of the capsule.

[0013] WO 2015 / 180960 A1 (Amcor Flexibles) concerns such a disposable beverage-brewing container comprising a body, with the beverage-forming ingredients and an antagonist foil connected to the body, by means of a heat-seal lacquer for closing it. In general, reaching higher pressures in the disposable beverage-brewing container causes a greater transport of flavors from the ingredients, intended for the formation of the beverage, into the injected liquid and therefore a beverage of higher quality. However, these higher pressures may cause a leakage or rupture at the level of the seal between the body and the antagonist foil and thus do not allow an optimal retaining of the liquid inside the container. Consequently, on the one hand the used heat-seal system must provide a stable closing of the beverage container. However, on the other hand said heat-seal system should not be environmental problematical or critical concerning food-safety. Unfortunately, this is often difficult to combine with the needed strong closing properties because the typically used heat seal lacquers normally need (in order to perform well) such critical components, like polyvinylchloride.

[0014] WO 2023 / 241929 A1 (Actega Rhenania GmbH) describes an extraction process carried out in a container C in which at least a portion of at least one transition component is separated from a carrier by a solvent, the container C comprises a lidding foil and a body defining a receiving space which contains the carrier, the lidding foil and the body are connected to one another with a heat-sealed seam, where the heat-sealed seam contains a heat-seal lacquer provided by a coating composition comprising 55 - 100 wt.% of a mixture of polyester resins, wherein the wt.% is relative to the total weight of the composition and wherein at least 20 wt.% of the mixture of the polyester resins is a polyester resin A1 having a Tg higher than 50 °C and at least 40 wt.% of the mixture of polyester resins is a polyester resin A2 having a Tg below 25 3. In a preferred embodiment the heat-sealing lacquer contains no polyvinylchloride. While the description gives many resources for obtaining polyester resins of type A1 , only two sources of polyester resins of type A2 are given.202400146 Foreign Filing 3

[0015] Object

[0016] It was therefore an object of the present invention to provide a sealing system that does not need the use of a polyester resin of type A2.

[0017] Other objects not explicitly mentioned will be apparent from the entirety of the description, claims, and examples below.

[0018] Achievement of objects

[0019] Surprisingly the inventors found that this object can be achieved by a film-forming dispersion, comprising a polyester or polyester mixture as polymer type A, a poly methyl methacrylate as polymer type B, optionally a graft copolymer of polymer type A and polymer type B as polymer type AB, a polyolefin or a polyolefin mixture as polymer type C, and a graft copolymer as polymer type CD, composed of polymer type C and polymer type D, polymer type D comprising units derived from methyl methacrylate and butyl methacrylate as monomers, said dispersion comprises of from 35 % to 65 % by weight of a solvent mixture comprising ethyl acetate, propyl acetate, heptane, and iso-octane ort-butyl acetate, based on the total weight of the dispersion.

[0020] The present invention is therefore directed to a film-forming dispersion, comprising a polyester or polyester mixture as polymer type A, a poly methyl methacrylate as polymer type B, optionally a graft copolymer of polymer type A and polymer type B as polymer type AB, a polyolefin or a polyolefin mixture as polymer type C, and a graft copolymer as polymer type CD, composed of polymer type C and polymer type D, polymer type D comprising units derived from methyl methacrylate and butyl methacrylate as monomers, said dispersion comprises of from 35 % to 65 % by weight of a solvent mixture comprising ethyl acetate, propyl acetate, heptane, and iso-octane ort-butyl acetate, based on the total weight of the dispersion, as claimed.

[0021] The present invention is further directed to a process for the sealing of various types of substrates, characterized in that a foil is coated with a coating system comprising the film-forming dispersion according to the invention and to a heat-sealable coating system suitable for the sealing of various types of substrates, comprising the film-forming dispersion of the invention.

[0022] The use of the film forming dispersion according to the invention has the advantage that no critical components, like polyvinylchloride are needed for sealing the container.

[0023] The dispersion according to the invention has the further advantage that no polyesters need to be used, that have a glass transition temperature of below 25 °C.

[0024] The dispersion according to the invention and the coating system of the invention can be used to produce sealings, especially sealing of aluminum foil against aluminum capsules as used in food packaging industry.202400146 Foreign Filing 4

[0025] The heat-sealing coating system of the invention has the advantage, that it can be used without the need for addition of plasticizer.

[0026] The film forming dispersion and the heat-sealing coating system of the invention has the further advantage that it allows a very tight sealing allowing the use of high pressure and high temperature when extracting tea or coffee from the sealed containers (capsules).

[0027] The products, processes, and uses (methods to use) according to the invention are described by way of example hereinafter, without any intention that the invention be restricted to these illustrative embodiments. When ranges, general formulae or classes of compounds are specified below, these are intended to encompass not only the corresponding ranges or groups of compounds which are explicitly mentioned but also all subranges and subgroups of compounds which can be obtained by leaving out individual values (ranges) or compounds. Where documents are cited in the context of the present description, their content shall fully form part of the disclosure content of the present invention, particularly in respect of the matters referred to. Percentages specified hereinbelow are by weight unless otherwise stated. Where average values are reported hereinafter, these are the numerical average, unless stated otherwise. Where properties of a material are referred to hereinafter, for example viscosities or the like, these are the properties of the material at 25 °C, unless stated otherwise. Where chemical (empirical) formulae are used in the present invention, the specified indices may be not only absolute numbers but also average values.

[0028] The film forming dispersion according to the invention comprises

[0029] a polyester or polyester mixture as polymer type A,

[0030] a poly methyl methacrylate as polymer type B,

[0031] optionally a graft copolymer of polymer type A and polymer type B as polymer type AB,

[0032] a polyolefin or a polyolefin mixture as polymer type C, and

[0033] a graft copolymer as polymer type CD, composed of polymer type C and polymer type D, polymer type D comprising units derived from methyl methacrylate and butyl methacrylate as monomers,

[0034] wherein the dispersion comprises of from 35 % to 65 % by weight, preferably of from 40 to 60 % by weight, and more preferably of from 45 to 55 % by weight of a solvent mixture (L) comprising ethyl acetate, propyl acetate, heptane, and iso-octane ort-butyl acetate, based on the total weight of the dispersion, and wherein said dispersion comprises of

[0035] from 10 to 20 % by weight of units based on polyester(s),

[0036] from 10 to 30 % by weight of units based on methyl methacrylate,

[0037] from 40 to 60 % by weight of units based on polyolefin(s), and

[0038] from 5 to 15 % by weight of units based on butyl methacrylate,

[0039] based in each case on the total mass of the polymer types A, B, C, AB, and CD.

[0040] In a preferred embodiment of the invention the afore mentioned amounts of units are to be understood as part by weight instead of % by weight.202400146 Foreign Filing 5

[0041] It might be advantageous if the polymer type A is a mixture of two polyesters and / or, preferably and, polymer type C is a mixture of two polyolefines.

[0042] The polymer type AB is preferably a graft copolymer with a polyester main chain and poly methyl methacrylate side chains. Preferred film forming dispersions according to the invention comprise at least one polymer type AB.

[0043] For the avoidance of doubt said solvent mixture (L) according to the invention comprises ethyl acetate, propyl acetate, heptane, and iso-octane or ethyl acetate, propyl acetate, heptane, and t-butyl acetate. More preferably said solvent mixture comprises of from 50 to 70 parts by weight, preferably 55 to 65 parts by weight of propyl acetate, of from 25 to 40 parts by weight of ethyl acetate, of from 2.5 to 7.5 parts by weight, preferably 4.0 to 6.0 parts by weight of heptane, and of from 2.5 to 7.5 parts by weight of isooctane or tert.-butyl acetate, preferably tert. -butyl acetate. Most preferably said solvent mixture comprises or preferably consists of from 50 to 70 % by weight, preferably 55 to 65 % by weight of propyl acetate, of from 25 to 40 % by weight of ethyl acetate, of from 2.5 to 7.5 % by weight, preferably 4.0 to 6.0 % by weight of heptane, and of from 2.5 to 7.5 % by weight of iso-octane or tert.-butyl acetate, preferably tert.-butyl acetate, based on the total weight of the solvent mixture.

[0044] The dispersion according to the invention preferably has a dynamic viscosity of from 200 to 10000 mPas, more preferably of from 500 to 7500 mPas, and most preferably 1000 to 6000 mPas, as determined by the method given in the example section. An inventive film-forming dispersion having a dynamic viscosity in the preferred range have the advantage that they can easily be processed when used in a heat sealing system.

[0045] The polymer type A

[0046] A person skilled in the art is in principle easily capable of selecting the polyesters of the polymer type A that are suitable for the coating composition of the invention. Avery wide range of polyesters can be used here. Selection criteria available to the person skilled in the art are particularly the solubility of the polyester in the respective solvent and - for food-contact applications - the appropriate approval of said component under food legislation.

[0047] The polyester used in a or for the preparation of a dispersion according to the present invention may comprise the reaction product of a polyacid and a polyol. "Polyacid" and like terms as used herein, refers to a compound having two or more carboxylic acid groups, such as two, three or four acid groups, and includes an ester of the polyacid (wherein one or more of the acid groups is esterified) or an anhydride. The polyacid is suitably an organic polyacid. The carboxylic acid groups of the polyacid may be connected by a bridging group selected from: an alkylene group, an alkenylene group, an alkynylene group, or an arylene group. Suitable examples of polyacids include, but are not limited to the following: maleic acid, fumaric acid, adipic acid, azelaic acid, succinic acid, sebacic acid, glutaric acid, decanoic diacid, dodecanoic diacid, phthalic acid, isophthalic acid, 5-tert-butylisophthalic acid, tetrachlorophthalic acid, tetrahydrophthalic acid, trimellitic acid, naphthalene dicarboxylic acid, naphthalene tetracarboxylic acid, terephthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, dimethyl terephthalate,202400146 Foreign Filing 6

[0048] cyclohexane dicarboxylic acid, chlorendic anhydride, 1 ,3-cyclohexane dicarboxylic acid, 1 ,4-cyclohexane dicarboxylic acid, tricyclodecane polycarboxylic acid, endomethylene tetrahydrophthalic acid, endoethylene hexahydrophthalic acid, cyclohexanetetra carboxylic acid, cyclobutane tetracarboxylic, esters and anhydrides of all the aforementioned acids and combinations thereof.

[0049] The polyester used in a or for the preparation of a dispersion according to the present invention may be formed from any suitable polyol. "Polyol" and like terms, as used herein, refers to a compound having two or more hydroxyl groups, such as two, three or four hydroxyl groups. The hydroxyl groups of the polyol may be connected by a bridging group selected from: an alkylene group; an alkenylene group; an alkynylene group; or an arylene group. Preferably the the polyol is an organic polyol.

[0050] Suitable examples of polyols include, but are not limited to the following: alkylene glycols, preferably ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, hexylene glycol, polyethylene glycol, polypropylene glycol, or neopentyl glycol, hydrogenated bisphenol A, cyclohexanediol, propanediols, preferably 1 ,2-propanediol, 1 ,3-propanediol, butyl ethyl propanediol, 2-methyl-1 ,3-propanediol, or 2-ethy l-2-butyl-1 ,3-propanediol, butanediols, preferably 1 ,4-butanediol, 1 ,3-butanediol, or 2-ethyl-1 ,4-butanediol, pentanediols, preferably trimethyl pentanediol or 2-methylpentanediol, cyclohexanedimethanol, hexanediols, preferably 1 ,6-hexanediol, caprolactonediol (for example, the reaction product of epsilon-capro lactone and ethylene glycol), hydroxyalkylated bisphenols, polyether glycols, preferablypoly(oxytetramethylene) glycol, trimethylol propane, pentaerythritol, dipentaerythritol, trimethylol ethane, trimethylol butane, dimethylol cyclohexane, glycerol and the like or combinations thereof.

[0051] Preferably the polyester used in a or for the preparation of a dispersion according to the present invention may be formed from comprise polymers or copolymers formed from the reaction of diols and diacids. Suitable examples of diacids include, but are not limited to the following: phthalic acid, isophthalic acid, terephthalic acid, 1,4 cyclohexane dicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid, 2,6-naphthalene dicarboxylic acid, orthophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, maleic anhydride, succinic anhydride, diester materials, such as dimethyl ester derivatives for example dimethyl isophthalate, dimethyl terephthalate, dimethyl 1 ,4-cyclohexane dicarboxylate, dimethyl 2,6-naphthalene di carboxylate, dimethyl fumarate, dimethyl orthophthalate, dimethylsuccinate, dimethyl glutarate, dimethyl adipate, esters and anhydrides of all the aforementioned acids, and mixtures thereof. Most preferably the polyester used in a or for the preparation of a dispersion according to the present invention may be formed from terephthalic acid, isophthalic acid, sebacic acid or combinations thereof. Suitable examples of diols include, but are not limited to the following: ethylene glycol, 1,2-propane diol, 1 ,3-propane diol, 1 ,2-butandiol, 1 ,3-butandiol, 1 ,4-butandiol, but-2-ene 1 ,4-diol, 2,3-butane diol, 2-methyl 1,3-propane diol, 2,2'-dimethyl 1 ,3-propanediol (neopentyl glycol), 1,5 pentane diol, 3-methyl 1,5-pentanediol, 2,4-diethyl 1,5-pentane diol, 1,6-hexane diol, 2-ethyl 1,3-hexane diol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 2,2,4-trimethyl pentane 1 ,3-diol, 1,4 cyclohexane dimethanol, tricyclodecane dimethanol, 2,2,4,4-tetramethyl cyclobutane 1 ,3-diol, isosorbide, 1 ,4-cyclohexane diol, 1 ,1'-isopropylidene-bis (4-cyclohexanol), and mixtures thereof. Most preferably the polyester used in a or for the preparation of a dispersion according to the present invention may be202400146 Foreign Filing 7

[0052] formed from 2,2'-dimethyl 1 ,3-propanediol (neopentyl glycol), 1 ,4-butandiol, 2-methyl 1 ,3-propanediol, ethylene glycol, 1 ,6-hexanediol or combinations thereof.

[0053] Materials that can preferably be used as polyesters (polymer type A) in the invention are polyesters which are free from monomers comprising polymerizable double bonds, e.g. itaconic acid and similar polyacids or polyols.

[0054] The polyesters (polymer type A) used in or for the production of the dispersion according to the invention can be produced by using known methods for (poly)condensation reactions as for example described in EP 3318337 A1.

[0055] Suitable commercially available polyesters are sold under the trade name URALAC and URADIL by DSM, ITALKID and ITALESTER by Galstaff-Multiresine, DOMOPOL by Helios, and DYNAPOL® by Evonik Operations GmbH. Preferred commercially available polyesters are DYNAPOL® L 206, DYNAPOL® L 411 , and DYNAPOL® L 658 from Evonik Operations GmbH.

[0056] The polyester or polyester mixture (polymer type A) preferably comprises polyester(s) based on fatty acids or polyester(s) based on di- and / or polycarboxylic acids selected from adipic acid, dimethyl adipate, sebacic acid, dimethyl sebacate, phthalic acid, isophthalic, acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, trimellitic acid, ester derivatives thereof and anhydrides thereof, and on mono- or polyhydric alcohols selected from ethylene glycol, 1,2-propanediol, 1 ,3-propanediol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, neopentyl glycol, butylethyl-1 ,3-propanediol, methyl-1 ,3-propanediol, methylpentanediols, cyclohexanedimethanols, tricyclo[2.2.1]decanedimethanol, isomers of limonenedimethanol, trimethylolpropane and mixtures thereof.

[0057] Preferably at least one of the polyesters has a molecular mass of from 10,000 to 30.000 g / mol.

[0058] Preferred dispersions according to the invention comprise at least one polyester having a glass transition temperature TG of higher than 30 °C, preferably of from 40 to 70 °C, determined by the method given in the example section.

[0059] Preferred dispersions according to the invention comprise at least one polyester having an OH value of from 3 to 10 mg KOH / g, preferably 5 to 8 mg KOH / g, determined by the method given in the example section.

[0060] Preferred dispersions according to the invention comprise at least one polyester having an acid value of from 1 to 5 mg KOH / g, preferably 2 to 4 mg KOH / g, determined by the method given in the example section.

[0061] Most preferred dispersion according to the invention comprise at least one polyester having a molecular mass of from 10,000 to 30.000 g / mol, a glass transition temperature TG of higher than 30 °C, preferably of from 40 to 70 °C, an OH value of from 3 to 10 mg KOH / g, preferably 5 to 8 mg KOH / g, and an acid202400146 Foreign Filing 8

[0062] value of from 1 to 5 mg KOH / g, preferably 2 to 4 mg KOH / g, all values determined by the methods given in the example section.

[0063] The polymer type C

[0064] The polyolefin or polyolefin mixture (polymer type C) that can be used in the invention, are known per se. Preferably these polyolefins are selected from EPM, hydrogenated polybutadienes, or copolymers of ethylene and of an a-olefin having from 4 to 12 carbon atoms, in particular of ethylene and butene or / and octene, and / or hexene. More preferably the polyolefines are selected from ethylene-butylene-copolymers. The weight-average molecular weight Mw of polymer type C is preferably of from 10 000 to 250000, more preferably from 50 000 to 230 000.

[0065] EPM is the abbreviation for ethylene-propylene copolymers. Distribution here can be substantially random, but it is also advantageously possible to use sequential polymers having ethylene blocks. The ethylene: propylene monomer ratio can vary within certain limits, which can be set at about 95 mol-% for ethylene and about 95 mol-% for propylene, as upper limit. Examples of suitable EPMs are described by way of example in the laid-open German specifications DE-A 1644 941 , DE A 1769834, DE- A 1939 037, DE-A 1963 039, and DE A 20 59 981. The EPDMs likewise described in those references are markedly less suitable in the invention, because these can increase the opacity of the coating.

[0066] More preferably at least one polyolefin comprises a proportion of from 60 to 90 %, preferably of from > 70 to 85 by weight of repeating ethylene units, and its weight-average molecular weight Mw is from 10 000 to 350 000, as determined by the method given in the example section.

[0067] It might be advantageous if a polyolefin or a polyolefin mixture is used as polymer type C where from 1 % to 20 %, preferably 2.5 % to 16 % of the carbons of the main chain of the polymer type C, are tertiary carbon atoms. By using such a kind of polymer as polymer type C a better flexibility of the coating can be achieved resulting in a smoother sealing. The ratio of tertiary carbon atoms in the main chain can be determined by the method giving in the example section.

[0068] Most preferably polymer type C comprises a proportion of from 60 to 90%, preferably of from > 70 to 85 by weight of repeating ethylene units, and from 1 % to 20 %, preferably 2.5 % to 16 % of the carbons of the main chain of the polymer type C are tertiary carbon atoms, and the weight-average molecular weight Mw of polymer type C is from 10 000 to 350 000.

[0069] Polyolefins, especially ethylene-butylene-copolymers, that can be used as polymer type C can be purchased for example from Dow Plastics under the trade name ENGAGE, preferably the products ENGAGE 7447 or 7387 HM, or from Mitsui Chemicals Group under the tradename TAFMER, preferably the product TAFMER DF 940.

[0070] The polymer types B and D202400146 Foreign Filing 9

[0071] The polymer type B might be formed alongside the graft copolymer AB during the production of the dispersion of the invention. The description below also applies to the composition of the B chains in the product constituent AB:

[0072] Polymer type and chain segment B are defined as being composed of methyl methacrylate. The polymer B is generally composed of standard methyl methacrylate (MMA) and optionally further (meth)acrylates. Polymer type B preferably only consists of units based on MMA.

[0073] The polymer type D might be formed alongside the graft copolymer CD during the production of the dispersion of the invention. The description below also applies to the composition of the D chains in the product constituent CD:

[0074] Polymer type and chain segment D are defined as being composed of methyl methacrylate and butyl methacrylate. The polymer D is generally composed of standard methyl methacrylate (MMA) and butyl methacrylate (BMA) and optionally further (meth)acrylates. Other suitable monomers for the polymer type B can be found by way of example in EP 1 989258, where the functional monomers likewise listed in that reference are restricted in the invention to OH functionalities, acid functionalities, and silyl functionalities. Polymer type D preferably only consists of units based on MMA and BMA.

[0075] In order to produce the graft copolymers AB and CD, grafting of polymer type B onto polymer type A and of polymer type D onto polymer type C might be carried out simultaneously. The polymer type B and D might have different compositions or have the same composition. Preferably polymer type B and polymer type D have a different composition.

[0076] The polymer type AB

[0077] Production of the graft polymers AB

[0078] The process of the invention for the production of a graft copolymer AB features reaction of a suitable initiator described at a later stage below with graftable groups, in particular with double bonds of repeating itaconic acid units in the polymer of the type A, to form reactive centers for free-radical polymerization of (meth)acrylates. The expression “reactive centers” means polymer chains which comprise one or more initiator units for free-radical polymerization. These initiator units can be formed simultaneously or else at different times. It is thus also very possible that itaconic acid units are activated only after other free radicals formed at other itaconic acid units have been deactivated by termination reactions.

[0079] The graft polymer AB is generally produced by grafting on the component A, under reaction conditions suitable for this purpose, monomers that lead to the component B. Correspondingly, the polymer type AB is preferably a graft copolymer having a polyester main chain and a poly(meth)acrylate side chain.

[0080] By way of example, a solution of from 10 to 65% by weight, preferably of from 30 to 45% by weight based on the total weight of the solution, of an itaconic-acid-containing polyester in a suitable solvent, the solvent being inert under polymerization conditions, and which normally has a boiling point above the process temperature is produced. Examples of solvents that can be used are acetic esters such as ethyl,202400146 Foreign Filing 10

[0081] propyl, or butyl acetate, aliphatic solvents such as isooctane, cycloaliphatic solvents such as cyclohexane, and carbonylic solvents such as butanone. Preferably ethyl acetate or cyclohexane, more preferably ethyl acetate is used as solvent. It might also be advantageous to use a mixture comprising or preferably consisting of ethyl acetate and cyclohexane.

[0082] The monomers that lead to the polymer type B are added to these polyester solutions, and polymerization is carried out with addition of one or more preferably peroxidic free-radical initiators preferably at temperatures of from -10°C to 100°C within a period that is preferably of from 4 to 8 hours. It is desirable, as far as possible, to achieve complete conversion. It is preferable to use, as free-radical initiator, azo compounds such as AIBN, or peresters such as tert-butyl per-octoate. The initiator concentration depends on the number of desired grafting sites, and on the desired molecular weight of the segment B. The initiator concentration is generally from 0.1 to 3% by weight, based on the polymer.

[0083] It is also possible to make concomitant use of chain-transfer agents in order to establish the desired molecular weight of the segments B. Examples of suitable chain-transfer agents are sulfur chain-transfer agents, in particular chain-transfer agents comprising mercapto groups, e.g. the chain-transfer agents described in the section relating to polymer type B. The concentrations of chain-transfer agents are generally from 0.1% by weight to 1.0% by weight, based on the entire polymer.

[0084] The graft copolymers of the polymer type AB can be synthesized not only by the solution polymerization method described but also in bulk. For this, the polyesters are dissolved in the (meth)acrylic monomer mixture before the free-radical polymerization is initiated.

[0085] Free-radical initiator can alternatively also be used as initial charge in a melt of the polyester; the monomer mixture then being admixed therewith.

[0086] The polymer type CD

[0087] Production of the graft polymers CD

[0088] The graft polymer CD is generally produced by - optionally with the aid of a suitable

[0089] emulsifier - producing a dispersion of the component C and grafting onto this, under reaction conditions suitable for this purpose, monomers that lead to polymer type B and D, respectively. The processes for the production of suitable grafted polymers of the types CB and CD respectively are known per se: by way of example it is possible to proceed by the transfer grafting method: (cf. also Houben-Weyl, Methoden der Org. Chemie [Methods of organic chemistry], vol. 1411, p. 114, H.A.J. Battaerd, G.W. Tregear, Polymer Reviews, vol. 16, Interscience (1967)).

[0090] By way of example, a solution of from 10 to 50% by weight, preferably from 20 to 40% by weight based on the total weight of the solution, of a polyolefin of the polymer type C in a suitable solvent which is inert under polymerization conditions, and which normally has a boiling point above the process temperature is produced. Examples of solvents that can be used are butyl acetate, aliphatic, cycloaliphatic, and aromatic hydrocarbons, and also mixtures of these. The monomers in the desired ratios are added to these solutions, and polymerization is carried out with the addition of one or more preferably peroxidic free-202400146 Foreign Filing 11

[0091] radical initiators at temperatures of from 50°C to 120°C, usually within 4 to 8 hours. It is desirable, as far as possible, to achieve complete conversion. It is preferable to use peresters such as tert-butyl peroctoate. The initiator concentration depends on the number of desired grafting sites, and on the desired chain lengths of the segments D. The initiator concentration is generally from 0.2 to 3.0% by weight, based on the polymer.

[0092] It is also possible to make concomitant use of chain-transfer agents in order to establish the desired molecular weight of the segments D. Examples of suitable chain-transfer agents are sulfur chain-transfer agents, in particular chain-transfer agents comprising mercapto groups, e.g. the chain-transfer agents listed in the section relating to polymer type B. The concentrations of chain-transfer agents are generally from 0.1% by weight to 1.0% by weight, based on the entire polymer. Another method for the production of the graft polymers CD provides the hydroperoxidation of a polyolefin as first step. The hydroperoxide groups thus formed, located in the chain, can initiate graft polymerization of the vinyl monomers in a following stage, (cf. H.A.J. Battaerd, G.W. Tregear, Polymer Reviews loc. cit.).

[0093] It might be preferably if the grafting of polymer type B onto polymer type A and of polymer type D onto polymer type C takes place simultaneously, in order to produce the graft copolymers AB and CD. The (statistical) composition of the side chains B and D here is identical. In the invention the resultant homopolymers are counted with polymer type B.

[0094] Alternatively, it is also possible to blend the polymer types AB and CD, preference being given here to simultaneous synthesis, since the dispersion thus produced has greater stability. The problem of phase separation can be reduced when comparison is made with simple blending.

[0095] In a third alternative, the polymer type AB is synthesized in the presence of the already grafted polymer type CD, of the ungrafted (non-grafted) polymer type C, and of the polymer type B formed during the synthesis of polymer type CD. This procedure can lead to formation of additional side chains on polymer type CD and to formation of additional polymers CD. Indeed, it is thus possible that polymer type CD having side chains D of different composition is present.

[0096] It is also possible to synthesize the polymer type CD analogously, and with analogous effects, in the presence of the polymer types AB, A, and B.

[0097] The dispersion of the invention can also comprise, alongside the polymer types A, B, AB, C and CD described, other components such as adhesion promoters, stabilizers, abrasion improvers, or antioxidants. An example of these additional materials based on polymers is the polymer type EA.

[0098] Polymer type EA can optionally be added in order to reduce possible abrasion during processing. By way of example, it is possible to use a polyamide, e.g. of the VESTOSINT ® 2159 (Evonik Operations GmbH) type. The proportion of polymer type EA in the dispersion is preferably from 0.1 to 10% by weight, preferably from 0.1 to 5% by weight, based on the total mass of the dispersion.202400146 Foreign Filing 12

[0099] Other materials that can moreover be added to the dispersion or the heat-sealable coating system suitable for the sealing of various types of substrates are, as described, the auxiliaries and additives usually used for heat-sealing.

[0100] Another constituent of the present invention, alongside the coating composition described, is a process for the sealing of two materials with the aid of the coating composition of the invention.

[0101] Production of the dispersion

[0102] Synthesis with the polymer types A - D

[0103] A dispersion or, given suitable polymer compatibility, a homogeneous solution, preferably a dispersion, of the components A and C in the solvent mixture (L) is produced, and monomers that lead to the component B (and D respectively) are simultaneously added under suitable reaction conditions to the reaction mixture comprising the components A and C. The ratios by weight of the proportions of A and B are preferably from 1 :5 to 5:1. The ratio by weight of A to C is preferably from 1 :5 to 5:1 , more preferably from 1:3 to 3:1. The production of the dispersion or homogeneous solution, preferably dispersion, might be supported by addition of a suitable emulsifier to the reaction mixture.

[0104] The total polymer content, based on the entire dispersion, is from 35% by weight to 65% by weight, normally from 40% by weight to 60% by weight.

[0105] The process according to the invention provides dispersions, that can be used as or for the production of heat-sealable coating systems, which have adequate stability for the processing method. The dispersions are stable for at least a plurality of days, normally a plurality of weeks to months.

[0106] In the inventive process for the sealing of various types of substrates, a foil is coated with a coating system comprising a dispersion according to the invention, the coating is dried at a temperature of from 150 to 220°C, preferably at a temperature of from 170 to 190 °C, and the coated side of the foil is placed onto the material to be sealed, and is sealed at a temperature of from 150 to 220°C, preferably at a temperature of from 170 to 190°C and with a pressure of from 0.2 to 1.0 MPa, preferably 0.4 to 0.8 MPa, over a period of from 0.1 to 10 seconds, preferably of from 0.5 to 2.5 seconds. The foil and the material to be sealed, both coming in to contact with the coating system, are preferably made from aluminum. The drying of the coating might be achieved at sub-atmospheric pressure, preferably at a temperature above the highest boiling point of the components of the solvent system / liquid phase.

[0107] The heat-sealable coating system according to the invention can be used for the sealing of various types of substrates and in different sealing processes. The heat-sealable coating system according to the invention is especially suitable for sealing aluminum against aluminum, aluminum against polypropylene (PP), aluminum against poly butylene terephthalate (PBT), polyethylene terephthalate (PET) against PP, and PET against PET, Possible end uses / products are coffee capsules or blisters for medicine (pills). Preferably the heat-sealable coating system according to the invention can be used for the sealing of aluminum foil against aluminum, especially to produce aluminum capsules, preferably filled aluminum capsules, more preferably filled with coffee powder or coffee extract / concentrate.202400146 Foreign Filing 13

[0108] Even without further exposition it is believed that a person skilled in the art will be able to make the widest use of the above description. The preferred embodiments and examples are therefore to be understood merely as a descriptive disclosure which is not in any way intended to be limiting.

[0109] The present invention will now be described more particularly with reference to examples. The examples given below illustrate the present invention in more detail, without restricting the invention to the features disclosed therein. Alternative embodiments of the present invention are obtainable analogously.

[0110] Examples:

[0111] Test methods:

[0112] Solid Content (SC) of the heat-sealable coating system:

[0113] Solid content (SC) was determined in a drying oven by drying the heat-sealable coating system for 1 h at 105°C. The weight of the sample was measured before and after the drying the solid content in % by weight is calculated according to the following formula:

[0114] (weight before drying -weight after drying) / weight before drying * 100

[0115] Dynamic viscosity:

[0116] Dynamic viscosity was determined with a Brookfield LVDV-ll+Pro viscosimeter at 23°C with spindle II at 6 rpm.

[0117] Molecular weight:

[0118] Molecular weight of the polymer was determined by gel permeation chromatography based on: DIN 55672-1 "Gel permeation chromatography, Part 1 : Tetrahydrofuran as eluent”.

[0119] Columns:

[0120] PSS SDV precolumn, 5 pm, 5 cm, 8 mm

[0121] PSS SDV 103, 5 pm, 30 cm, 8 mm

[0122] PSS SDV 105, 5 pm, 30 cm, 8 mm

[0123] PSS SDV 106, 5 pm, 30 cm, 8 mm

[0124] PSS SDV 107, 5 pm, 30 cm, 8 mm

[0125] Manufacturer: PSS Polymer Standard-Service, Mainz

[0126] Eluent: tetra hydrofuran (THF), stabilized with 250 ppm BHT (2,6-di-tert.butyl-4-methylphenol) Flow: 1 .0 mL / min

[0127] Oven temperature: 35 °C (air)

[0128] Sample solvent: tetra hydrofuran (THF), stabilized with 1000 ppm BHT (2,6-di-tert.-butyl-4-methylphenol), BHT serves as internal standard

[0129] Sample concentration: 2.5 g solids / 1 (weight 37.5 mg per 15 ml THF)

[0130] Dissolve while stirring at RT for at least 16 hours (overnight), filter via disposable filter M&N Chromafil organic type 0-45 / 25

[0131] Injection volume: 100 pl

[0132] Detection: Rl (refractive index)202400146 Foreign Filing 14

[0133] Runtime: 35 min, with staggered injection 35 min

[0134] Calibration standards: Polystyrene

[0135] Evaluation software: PSS WinGPC

[0136] Result: polystyrene or PMMA molecular weight equivalents.

[0137] PMMA molecular weight equivalents by universal calibration using the Mark-Houwink Constant for PS: a=0.714 I K=0.01363; for PMMA: a=0.688 I K=0.01298

[0138] Mw(PS or PMMA), Mn(PS or PMMA), Mp(PS or PMMA), Polydispersity D=Mw / Mn

[0139] The molecular mass of the polyesters is calculated based on contents of hydroxyl- and carboxyl- end groups.

[0140] Glass transition Temperature (TG):

[0141] The glass transition temperature of the polyester(s)s was determined using the DSC method (differential scanning calorimetry) according to ASTM D6604-00(2013) ("Standard Practice for Glass Transition Temperatures of Hydrocarbon Resins by Differential Scanning Calorimetry". Heat-flux differential scanning calorimetry (DSC), sample pans: aluminum, reference: blank, calibration: indium and mercury, sample weight: 10mg, heating rate: 20°C / min). The values stated are taken from a second heating cycle.

[0142] OH value (hydroxyl value):

[0143] The Hydroxy value (number, OHN) is determined in accordance with DIN 53240-2. Approximately 3 g of polyester are dissolved in dichloromethane. The OH groups contained in the solution are esterified at room temperature with acetic anhydride, 4,4-dimethyl amino-pyridine being used as a catalyst. Following the hydrolysis of the anhydride, the titration is made using 0.5 N methanolic KOH solution.

[0144] Acid value

[0145] The acid value (number) is determined according to DIN EN ISO 2114. Approximately 4 g of polyester are dissolved in 50 ml of tetrahydrofuran. A titration is made with 0.1 N methanolic KOH with phenolphthalein as indicator.

[0146] NMR spectroscopy:

[0147] The samples were dissolved at 120 °C in tetrachloroethane-d2 (TCE) and 13C-NMR spectra included DEPT135 were measured.

[0148] Instrument: Bruker Avance 500 III HD, with cryogenic probe head

[0149] Software for evaluation: Bruker Topspin 3.5

[0150] The evaluation is based on suitable literature spectra:

[0151] NMR Spectra of Polymers and Polymer Additives, Anita J. Brandolini, Deborah D. Hills, Marcel Dekker Inc., New York, 2000202400146 Foreign Filing 15

[0152] Particle Size Distribution:

[0153] The particle size was determined by measurements with a Coulter LS 13320 with Polarization Intensity Differentia Scattering (PI DS) in a range of 0.4 to 2000 pm. The polymer samples were dispersed with Butyl acetate (technical grade).

[0154] Software: Beckman Coulter LS, Vers. 6.03, Nov. 2009

[0155] Evaluation: Fraunhofer-Evaluation Model (Theory) (https: / / www.beckman.de / en / resources / technologies / laser-diffraction)

[0156] Materials used:

[0157] A foil of 38pm thickness made of soft aluminum alloy 8011 from SYMETAL was used as foil material. A soft aluminum alloy 8011 with a thickness of 90 pm from SYMETAL (abbreviation: AI90) was used as (Cup) sheet material.

[0158] TRIGONOX® 21 S, a tert-Butyl peroxy-2-ethylhexanoate initiator purchased from Nouryon.

[0159] DYNAPOL® L 658, a saturated, high molecular, branched copolyester having molecular mass of 20,000 g / mol, a TG of 40 °C, an OH value of 8 and an acid value of 4, available from Evonik Operations GmbH. DYNAPOL® L 206, a polyester resin having molecular mass of 20,000 g / mol, a TG of 67 °C, an OH value of 5 and an acid value of 2, available from Evonik Operations GmbH.

[0160] DYNAPOL® L 411, a polyester resin available having molecular mass of 16,000 g / mol, a TG of 47 °C, an OH value of 5 and an acid value of 2, from Evonik Operations GmbH.

[0161] TAFMER DF 110, DF 605, and DF 940 are ethylene based a-olefin elastomers and can be purchased from Mitsui Chemicals Group.

[0162] ENGAGE™ 7447 a high flow, low density Ethylene-butene (EB) polyolefin elastomer that can be purchased from DOW Plastics.

[0163] DUTRAL® CO 043, an Ethylene - Propylene polymer produced by suspension polymerisation using a Ziegler-Natta Catalyst comprising a non-staining antioxidant added during the production process that can be purchased from VERSALIS S.p.A.

[0164] The poly-olefine sample ENGAGE 7447 was dissolved in tetrachloroethane-d2 (TCE) at 120 °C and13C-NMR spectra including DEPT were measured. The sample shows a copolymer consisting of ethylene (C2) and butene-1 (C4). The ratio for this sample is: 83 mol% (71 wt.%) C2 and 17 mol% (29 wt.%) C4. TAFMER DF 940 was dissolved in tetrachloroethane-d2 (TCE) at 120 °C and13C-NMR spectra including DEPT was measured. The sample shows a copolymer consisting of ethylene (C2) and butene-1 (C4). The ratio for this sample is: 84 wt.% C2 and 16 wt.% C4.

[0165] Production of the heat-sealing coating systems

[0166] Inventive example 1

[0167] 73 g DUTRAL® CO 043, 540 g n-Propyl acetate and 95 g isooctane were used as initial charge in a pressure vessel with attached thermostat, blade stirrer, and internal thermometer, and stirred at 85°C until the material had dissolved. Afterwards 0.62 g of t-butyl peroxy-2-ethylhexanoate and 10.0 g ethyl acetate were added. After 10 minutes stirring at 85 °C, a mixture of 142,4 g of methyl methacrylate and 142,4 g of butyl methacrylate, with admixed 1.8 g of tert butylperox-2-ethylhexanoate was metered into the system by means of a metering pump over a period of 1.5 h at 85°C. The reaction mixture was stirred for a202400146 Foreign Filing 16

[0168] further 5 h at 85 °C and then cooled down to room temperature. 147,5 g propyl acetate, 25,81 g n-heptane and 250,3 g TAFMER™DF 110 were added and stirred at 93 °C for five hours until the material had dissolved. At a reaction temperature of 85 °C and a stirring speed of 250 rpm, 199.3 g of a 40 wt.% solution of DYNAPOL ® L 206 in ethyl acetate was added via a funnel. After a short homogenization, 68.25 g of methyl methacrylate, dissolved in 8.4 g of ethyl acetate, were added to the reaction mixture via a funnel. At a reaction temperature of 85°C, the reaction was started by adding 0.73 g tertiary-butyl-2-ethylperoxyhexanoate dissolved in 5 g ethyl acetate to the reaction vessel. A slight exothermic reaction was observed. After one hour of reaction time at 85 °C and a stirring speed of 250 rpm, another 0.192 g of peroxide was added. After another 2 hours under the same conditions, another 0.192 g tertiary-buty I-2-ethylperoxyhexanoate was added to reduce the residual monomers. In the next step, a post-reaction time of a total of 5 hours took place at 85 °C. The product was filtered with a 125 pm filter sieve and filled into a glass bottle. A weak nitrogen stream is directed into the flask during the entire reaction time in order to achieve a saturated nitrogen atmosphere.

[0169] Comparative example 1

[0170] 73 g DUTRAL CO 043, 540 g n-Propyl acetate and 95 g isooctane were used as initial charge in a pressure vessel with attached thermostat, blade stirrer, and internal thermometer, and stirred at 85°C until the material had dissolved. Afterwards 0.62 g of t-butyl peroxy-2-ethylhexanoate and 10.0 g ethyl acetate were added. After 10 minutes stirring at 85 °C, a mixture of 142,4 g of methyl methacrylate and 142,4 g of butyl methacrylate, with admixed 1.8 g of tert butylperox-2-ethylhexanoate was metered into the system by means of a metering pump over a period of 1.5 h at 85°C. The reaction mixture was stirred for a further 5 h at 85 °C and then cooled down to room temperature. 114,7 g propyl acetate, 20,1 g iso octane, 38,4 g ethyl acetate and 250,3 g TAFMER™DF 110 were added and stirred at 85 °C for five hours until the material had dissolved. At a reaction temperature of 85 °C and a stirring speed of 250 rpm, 199.3 g of a 40 wt.% solution of DYNAPOL L 206 in ethyl acetate was added via a funnel. After a short homogenization, 68.25 g of methyl methacrylate, dissolved in 8.4 g of ethyl acetate, were added to the reaction mixture via a funnel. At a reaction temperature of 85°C, the reaction was started by adding 0.73 g tertiary-butyl-2-ethylperoxyhexanoate dissolved in 5 g ethyl acetate to the reaction vessel. A slight exothermic reaction was observed. After one hour of reaction time at 85 °C and a stirring speed of 250 rpm, another 0.192 g of peroxide was added. After another 2 hours under the same conditions, another 0.192 g tertiary-butyl-2-ethylperoxyhexanoate was added to reduce the residual monomers. In the next step, a post-reaction time of a total of 5 hours took place at 85 °C. The product was filtered with a 125 pm filter sieve and filled into a glass bottle. A weak nitrogen stream is directed into the flask during the entire reaction time in order to achieve a saturated nitrogen atmosphere.

[0171] Inventive example 2

[0172] 73 g DUTRAL® CO 043, 540 g n-Propyl acetate and 95 g isooctane were used as initial charge in a pressure vessel with attached thermostat, blade stirrer, and internal thermometer, and stirred at 85°C until the material had dissolved. Afterwards 0.62 g of t-butyl peroxy-2-ethylhexanoate and 10.0 g ethyl acetate were added. After 10 minutes stirring at 85 °C, a mixture of 142,4 g of methyl methacrylate and 142,4 g of butyl methacrylate, with admixed 1.8 g of tert butylperox-2-ethylhexanoate was metered into the system by means of a metering pump over a period of 1.5 h at 85°C. The reaction mixture was stirred for a202400146 Foreign Filing 17

[0173] further 5 h at 85 °C and then cooled down to room temperature. 147,5 g propyl acetate, 25,81 g n-heptane and 125,2 g TAFMER™ DF 110 and 125,2 g TAFMER™ DF 605 were added and stirred at 93°C for five hours until the material had dissolved. At a reaction temperature of 85 °C and a stirring speed of 250 rpm, 199.3 g of 40 wt.% solution of DYNAPOL® L 206 in ethyl acetate was added via a funnel. After a short homogenization, 68.25 g of methyl methacrylate, dissolved in 56,4 g of ethyl acetate, were added to the reaction mixture via a funnel. At a reaction temperature of 85 °C, the reaction was started by adding 0.73 g tertiary-butyl-2-ethylperoxyhexanoate dissolved in 5 g ethyl acetate to the reaction vessel. A slight exothermic reaction was observed. After one hour of reaction time at 85 °C and a stirring speed of 250 revolutions / minute, another 0.192 g of peroxide was added. After another 2 hours under the same conditions, another 0.192 g tertiary butyl-2-ethyl-peroxyhexanoate was added to reduce the residual monomers. In the next step, a post-reaction time of a total of 5 hours took place at 85 °C. The product was filtered with a 125 pm filter sieve and filled into a glass bottle. A weak nitrogen stream is directed into the flask during the entire reaction time in order to achieve a saturated nitrogen atmosphere.

[0174] Inventive example 3

[0175] 75 g ENGAGE™ 7447, 533 g n-Propyl acetate, and 87 g tert-butyl acetate as initial charge in a pressure vessel with attached thermostat, blade stirrer, and internal thermometer, and stirred at 85°C until the material had dissolved. Afterwards 0.62 g oft-butyl peroxy-2-ethylhexanoate and 10.0 g ethyl acetate were added. After 10 minutes stirring at 85 °C, a mixture of 147 g of methyl methacrylate and 147 g of butyl methacrylate, with admixed 1.8 g oft-butyl perox-2-ethylhexanoate was metered into the system by means of a metering pump over a period of 1.5 h at 85°C. The reaction mixture was stirred for a further 5 h at 85 °C and then cooled down to room temperature. 147,5 g n-propyl acetate, 25,81 g n-heptane and 250,3 g TAFMER ™ DF 940 were added and stirred at 93 °C for five hours until the material had dissolved. At a reaction temperature of 85 °C and a stirring speed of 250 rpm, 199.3 g of 40 wt.% solution of DYNAPOL ® L 206 in ethyl acetate was added via a funnel. After a short homogenization, 68.25 g of methyl methacrylate, dissolved in 8,42 g of ethyl acetate, were added to the reaction mixture via a funnel. At a reaction temperature of 85 °C, the reaction was started by adding 0.73 g tertiary-butyl-2-ethylperoxyhexanoate dissolved in 5 g ethyl acetate to the reaction vessel. A slight exothermic reaction was observed. After one hour of reaction time at 85 °C and a stirring speed of 250 rpm, another 0.192 g of peroxide was added. After another 2 hours under the same conditions, another 0.192 g tertiary butyl-2-ethyl-peroxyhexanoate was added to reduce the residual monomers. In the next step, a post-reaction time of a total of 5 hours took place at 85°C. The product was filtered with a 125 pm filter sieve and filled into a glass bottle. A weak nitrogen stream is directed into the flask during the entire reaction time in order to achieve a saturated nitrogen atmosphere.

[0176] Inventive example 4

[0177] 75 g ENGAGE™ 7447, 533 g n-Propyl acetate, and 87 g tert-butyl acetate as initial charge in a pressure vessel with attached thermostat, blade stirrer, and internal thermometer, and stirred at 85°C until the material had dissolved. Afterwards 0.62 g oft-butyl peroxy-2-ethylhexanoate and 10.0 g ethyl acetate were added. After 10 minutes stirring at 85 °C, a mixture of 147 g of methyl methacrylate and 147 g of butyl methacrylate, with admixed 1.8 g oft-butyl perox-2-ethylhexanoate was metered into the system by means of a metering pump over a period of 1.5 h at 85°C. The reaction mixture was stirred for a further 5202400146 Foreign Filing 18

[0178] h at 85 °C and then cooled down to room temperature. 147,5 g n-propyl acetate, 25,81 g n-heptane and 250,3 g TAFMER ™ DF 940 were added and stirred at 96°C for five hours until the material had dissolved. At a reaction temperature of 85 °C and a stirring speed of 250 rpm, 199.3 g of 40 wt.% solution of DYNAPOL ® L 658 in ethyl acetate was added via a funnel. After a short homogenization, 68.25 g of methyl methacrylate, dissolved in 8,42 g of ethyl acetate, was added to the reaction mixture via a funnel. At a reaction temperature of 85 °C, the reaction was started by adding 0.73 g tertiary-butyl-2-ethylperoxyhexanoate dissolved in 5 g ethyl acetate to the reaction vessel. A slight exothermic reaction was observed. After one hour of reaction time at 85 °C and a stirring speed of 250 rpm, another 0.192 g of peroxide was added. After another 2 hours under the same conditions, another 0.192 g tertiary butyl-2-ethyl-peroxyhexanoate was added to reduce the residual monomers. In the next step, a post-reaction time of a total of 5 hours took place at 85 °C. The product was filtered with a 125 pm filter sieve and filled into a glass bottle. A weak nitrogen stream is directed into the flask during the entire reaction time in order to achieve a saturated nitrogen atmosphere.

[0179] Inventive example 5

[0180] 75 g ENGAGE™ 7447, 533 g n-Propyl acetate, and 87 g tert-butyl acetate as initial charge in a pressure vessel with attached thermostat, blade stirrer, and internal thermometer, and stirred at 85°C until the material had dissolved. Afterwards 0.62 g oft-butyl peroxy-2-ethylhexanoate and 10.0 g ethyl acetate were added. After 10 minutes stirring at 85 °C, a mixture of 147 g of methyl methacrylate and 147 g of butyl methacrylate, with admixed 1.8 g oft-butyl perox-2-ethylhexanoate was metered into the system by means of a metering pump over a period of 1.5 h at 85°C. The reaction mixture was stirred for a further 5 h at 85 °C and then cooled down to room temperature. 147,5 g n-propyl acetate, 25,81 g n-heptane and 250,3 g TAFMER ™ DF 940 were added and stirred at 96°C for five hours until the material had dissolved. At a reaction temperature of 85 °C and a stirring speed of 250 rpm, 199.3 g of a 40 wt.% solution of DYNYPOL ® L 411 in ethyl acetate was added via a funnel. After a short homogenization, 68.25 g of methyl methacrylate, dissolved in 8,42 g of ethyl acetate, were added to the reaction mixture via a funnel. At a reaction temperature of 85°C, the reaction was started by adding 0.73 g tertiary-butyl-2-ethylperoxyhexanoate dissolved in 5 g ethyl acetate to the reaction vessel. A slight exothermic reaction was observed. After one hour of reaction time at 85 °C and a stirring speed of 250 rpm, another 0.192 g of peroxide was added. After another 2 hours under the same conditions, another 0.192 g tertiary butyl-2-ethyl-peroxyhexanoate was added to reduce the residual monomers. In the next step, a post-reaction time of a total of 5 hours took place at 85 °C. The product was filtered with a 125 pm filter sieve and filled into a glass bottle.

[0181] A weak nitrogen stream is directed into the flask during the entire reaction time in order to achieve a saturated nitrogen atmosphere.

[0182] Inventive example 6: Scale up of inventive sample 5

[0183] The synthesis of the inventive example 6 was performed analogous to the synthesis of inventive example 5, but with the difference of the reactor size / batch size. The batch was 3.5 times larger and was also carried out in 3 reaction steps under nitrogen in a 5-litre Belatec apparatus.

[0184] Inventive example 7: Scale up of inventive sample 4202400146 Foreign Filing 19

[0185] The synthesis of the inventive example 7 was performed analogous to the synthesis of inventive example 4, but with the difference of the reactor size / batch size. The batch was 3.5 times larger and was also carried out in 3 reaction steps under nitrogen in a 5-litre Belatec apparatus.

[0186] Inventive example 8

[0187] 75 g ENGAGE™ 7447, 533 g n-Propyl acetate, and 87 g tert-butyl acetate as initial charge in a pressure vessel with attached thermostat, blade stirrer, and internal thermometer, and stirred at 85°C until the material had dissolved. Afterwards 0.62 g oft-butyl peroxy-2-ethylhexanoate and 10.0 g ethyl acetate were added. After 10 minutes stirring at 85 °C, a mixture of 147 g of methyl methacrylate and 147 g of butyl methacrylate, with admixed 1.8 g oft-butyl perox-2-ethylhexanoate was metered into the system by means of a metering pump over a period of 1.5 h at 85°C. The reaction mixture was stirred for a further 5 h at 85 °C and then cooled down to room temperature. 147,5 g n-propyl acetate, 25,81 g n-heptane and 166,89g TAFMER ™ DF 940 and 83,45 g TAFMER ™ DF 110 were added and stirred at 96°C for five hours until the material had dissolved. At a reaction temperature of 85 °C and a stirring speed of 250 rpm, 199.3 g of 40 wt.% solution of DYNAPOL ® L 206 in ethyl acetate was added via a funnel. After a short homogenization, 68.25 g of methyl methacrylate, dissolved in 8,42 g of ethyl acetate, were added to the reaction mixture via a funnel. At a reaction temperature of 85°C, the reaction was started by adding 0.73 g tertiary-butyl-2-ethylperoxyhexanoate dissolved in 5 g ethyl acetate to the reaction vessel. A slight exothermic reaction was observed. After one hour of reaction time at 85 °C and a stirring speed of 250 rpm, another 0.192 g of peroxide was added. After another 2 hours under the same conditions, another 0.192 g tertiary butyl-2-ethyl-peroxyhexanoate was added to reduce the residual monomers. In the next step, a post-reaction time of a total of 5 hours took place at 85°C. The product was filtered with a 125 pm filter sieve and filled into a glass bottle. A weak nitrogen stream is directed into the flask during the entire reaction time in order to achieve a saturated nitrogen atmosphere.

[0188] Inventive example 9

[0189] 75 g ENGAGE™ 7447, 533 g n-Propyl acetate, and 87 g tert-butyl acetate as initial charge in a pressure vessel with attached thermostat, blade stirrer, and internal thermometer, and stirred at 85°C until the material had dissolved. Afterwards 0.62 g oft-butyl peroxy-2-ethylhexanoate and 10.0 g ethyl acetate were added. After 10 minutes stirring at 85 °C, a mixture of 147 g of methyl methacrylate and 147 g of butyl methacrylate, with admixed 1.8 g oft-butyl perox-2-ethylhexanoate was metered into the system by means of a metering pump over a period of 1.5 h at 85°C. The reaction mixture was stirred for a further 5 h at 85 °C and then cooled down to room temperature. 147,5 g n-propyl acetate, 25,81 g n-heptane and 125,17 g TAFMER ™ DF 940 and 125,17 g TAFMER ™ DF 110 were added and stirred at 96°C for five hours until the material had dissolved. At a reaction temperature of 85 °C and a stirring speed of 250 rpm, 119,6 g of DYNAPOL ® L 206 and 79,7 g ethyl acetate was added via a funnel. After a short homogenization, 68.25 g of methyl methacrylate, dissolved in 8,42 g of ethyl acetate, were added to the reaction mixture via a funnel. At a reaction temperature of 85 °C, the reaction was started by adding 0.73 g tertiary-butyl-2-ethylperoxyhexanoate dissolved in 5 g ethyl acetate to the reaction vessel. A slight exothermic reaction was observed. After one hour of reaction time at 85 °C and a stirring speed of 250 rpm, another 0.192 g of peroxide was added. After another 2 hours under the same conditions, another 0.192 g tertiary butyl-2-ethyl-peroxyhexanoate was added to reduce the residual monomers. In the next202400146 Foreign Filing 20

[0190] step, a post-reaction time of a total of 5 hours took place at 85°C. The product was filtered with a 125 pm filter sieve and filled into a glass bottle. A weak nitrogen stream is directed into the flask during the entire reaction time in order to achieve a saturated nitrogen atmosphere.

[0191] Experimental results

[0192] Some properties of the binders obtained in inventive examples 1 to 9 can be found in table 1 below.

[0193] Table 1: properties of the binder

[0194] d10 d50 d90

[0195] dyn. vise. (Vol) (Vol) (Vol) Example SC [%] [mPas] appearance [pm] [pm] [pm]

[0196] 1 50.8 5700 white, disperse 0.3 1.2 6.3

[0197] 2 48.3 1600 white, disperse 0.6 2.2 38.4

[0198] 3 50.2 1300 white, disperse 1.1 2.1 3.7

[0199] 4 50.5 3000 white, disperse 1.1 1.6 2.3

[0200] 5 50.3 3200 white, disperse 1.3 1.9 2.6

[0201] 6 50.6 2700 white, disperse 2.6 3.8 5.0

[0202] 7 50.6 2400 white, disperse 3.0 4.0 5.2

[0203] 8 49,9 620 white, disperse 1,4 2,5 4,7

[0204] 9 49,5 600 white, disperse 3,7 5,3 5,3

[0205]

[0206] SC: solid content in % by weight

[0207] dyn. vise.: dynamic viscosity in mPas

[0208] All the inventive examples exhibit solids-viscosity ratios that ensure processability for users and meet the requirement to achieve the highest possible solid contents. Comparative example 1 did not result in a (stable) organic dispersion / solution. Therefore, neither binder properties nor heat-sealing properties could be determined.

[0209] Laboratory application of the heat-sealing coating systems

[0210] The heat-sealing coating systems obtained in inventive examples 1 to 9 were tested by applying the coating systems by drawing on a K hand coater 30 p onto an aluminum foil of 38 pm thickness made from 8011 aluminum alloy (available from SYMETAL ALUMINIUM FOIL INDUSTRY SINGLE MEMBER S.A., Greece). Dry layers having a thickness of 10 pm were thus obtained.

[0211] Laboratory drying of the coated foils

[0212] After a short period of air-drying (from 5 to 10 minutes), the foils were dried in a convection oven at from 180°C for 15 seconds.

[0213] Heat-sealing and determination of heat seal strength and seal seam strength202400146 Foreign Filing 21

[0214] Heat-sealing equipment (HSG-C) from Brugger was used to carry out the sealing processes. The cup sheet material used was a soft aluminum alloy 8011 with a thickness of 90 pm from SYMETAL (abbreviation: AI90).

[0215] Sealing conditions:

[0216] Temperature: 200°C

[0217] Pressure: 0.6 MPa

[0218] Time: 1.0 sec.

[0219] Heat seal strength (HSS) was determined by cutting samples into strips of width 15 mm and using a tensile tester from ZwickRoell, model zwickiLine Z0.5TN material testing machine (with an Xforce HP force transducer box, nominal force 100N) to subject same to tension at velocity 100 mm / min. Care was taken that during the peel test the angle between the foil parts already separated and the as yet unstressed remainder were 90° and additional 180°. The results are given in table 2 below.

[0220] Table 2: Heat-sealing properties

[0221] Material HSS Appearance of Breaking

[0222] Example Material lid

[0223] cup [N / 15mm] seal point

[0224] 1 aluminum AI90 23.0 uniform cohesion

[0225] 2 aluminum AI90 17.7 uniform cohesion

[0226] 3 aluminum AI90 21.9 uniform cohesion

[0227] 4 aluminum AI90 18.4 uniform cohesion

[0228] 5 aluminum AI90 21.6 uniform cohesion

[0229] 6 aluminum AI90 19.2 uniform cohesion

[0230] 7 aluminum AI90 18.2 uniform cohesion

[0231] 8 aluminum AI90 20,7 uniform cohesion

[0232] 9 aluminum AI90 14,2 uniform cohesion

[0233]

[0234] With samples from examples 1 to 9 a test for heat resistance was performed. All examples passed the test for heat resistance [1.5 kg].

[0235] Test for Heat Resistance

[0236] Two aluminum foils, each coated with 10 pm, are used: one capsule aluminum (90pm) and one lid aluminum (38pm). A strip was sealed with a width of 15mm, lacquer against lacquer, at 200°C, for 1 second, at 0.6 MPa. One end is folded back 180° and fixed in the upper area of a heated drying oven. A weight of 100 g is attached to the other end, and the time is recorded.

[0237] The test ends when:

[0238] A) 30 minutes of standing time in the drying oven have passed; in this case, the still intact seal seam is measured and reported in millimeters, or

[0239] B) The weight falls off due to the completely opened seal seam before the end of the 30

[0240] minutes; in this case, the time is noted. The test results are given in table 3 below.202400146 Foreign Filing 22

[0241] Test for AI-AI Blocking Temperature

[0242] To test the blocking temperature of heat seal lacquers, two films of 20 x 10 cm (Al foil of 38 pm thickness) were coated with 6 g of lacquer each. The drying of the films occurs after a short ventilation time (~1 min) individually for 15 seconds at 180 °C in a convection oven. The block strength test was done with a Brugger HSG / ETK, where the lower sealing jaw made of steel is replaced with an elastic sealing jaw with a silicone rubber surface. Only the upper jaw was heated. The temperature was gradually increased in steps of 5 °C. The block point is defined as the temperature at which the sample (coating against coating) no longer falls apart on its own. The sealing pressure was 0.1 MPa, and the sealing time was 30 seconds. The test results are given in table 3 below.

[0243] Table 3:

[0244] Heat resistance at

[0245] Example AI-AI Blocking temperature 100 °C 110 °C 120 °C 130 °C 140 °C 10 mm 1 75 °C 0 mm 0 mm 0 mm 0 mm

[0246] (22 min) 10 mm 2 70-75 °C 0 mm 0 mm 0 mm 0 mm

[0247] (11 min) 10 mm 3 75 °C 0 mm 0 mm 1 mm 9 mm

[0248] (9 min) 10 mm

[0249] 5 75 °C 0 mm 0 mm 4 mm n.d.

[0250] (24 min)

[0251] 10 mm

[0252] 6 70 °C 0 mm 2 mm 4 mm n.d.

[0253] (20 min)

[0254] 10 mm

[0255] 7 65 °C 0 mm 1 mm 0 mm n.d.

[0256] (15 min)

[0257] 10 mm 10 mm 8 70 °C 0 mm 0 mm 0 mm

[0258] (25 min) (6 min)

[0259] 10 mm 9 70 °C 0 mm 0 mm 0 mm 5 mm

[0260] (18 min)

[0261]

[0262] n.d.: not determined

Claims

202400146 Foreign Filing 23PATENT CLAIMS1. A film-forming dispersion, comprisinga polyester or polyester mixture as polymer type A,a poly methyl methacrylate as polymer type B,optionally a graft copolymer of polymer type A and polymer type B as polymer type AB, a polyolefin or a polyolefin mixture as polymer type C, anda graft copolymer as polymer type CD, composed of polymer type C and polymer type D, polymer type D comprising units derived from methyl methacrylate and butyl methacrylate as monomers, characterized in that said dispersion comprises of from 35 % to 65 % by weight of a solvent mixture comprising ethyl acetate, propyl acetate, heptane, and iso-octane ort-butyl acetate, based on the total weight of the dispersion, and wherein said dispersion comprises offrom 10 to 20 % by weight of units based on polyester(s),from 10 to 30 % by weight of units based on methyl methacrylate,from 40 to 60 % by weight of units based on polyolefin(s), andfrom 5 to 15 % by weight of units based on butyl methacrylate,based in each case on the total mass of the polymer types A, B, C, AB, and CD.

2. The dispersion as claimed in claim 1 , characterized in that said solvent mixture comprises of from 50 to 70 parts by weight of propyl acetate, of from 25 to 40 parts by weight of ethyl acetate, of from 2.5 to 7.5 parts by weight of heptane, and of from 2.5 to 7.5 parts by weight of iso-octane or tert.-buty I acetate, based on the total weight of the solvent mixture.

3. The dispersion as claimed in at least one of claims 1 or 2, characterized in that the polyolefin or polyolefin mixture comprises an EPM, a hydrogenated polybutadiene, or a copolymer of ethylene and of an a-olefin having from 4 to 12, preferably 4 to 6 carbon atoms.

4. The dispersion as claimed in at least one of claims 1 to 3, characterized in that at least one polyolefin comprises a proportion of from 60 to 90 % by weight, preferably of from > 70 to 85 % by weight of repeating ethylene units, and its weight-average molecular weight Mwis from 10000 to 350000 g / mol.

5. The dispersion as claimed in at least one of claims 1 to 4, characterized in that the dispersion has a dynamic viscosity of from 200 to 10000 mPas, preferably of from 500 to 7500 mPas, and more preferably 1000 to 6000 mPas, as determined by the method given in the description.

6. The dispersion as claimed in at least one of claims 1 to 5, characterized in that the polyester or polyester mixture comprises polyester(s) based on fatty acids or polyester(s) based on di- and / or polycarboxylic acids selected from adipic acid, dimethyl adipate, sebacic acid, dimethyl sebacate, phthalic acid, isophthalic, acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, trimellitic acid, ester derivatives thereof and anhydrides thereof, and on mono- or polyhydric alcohols selected from ethylene glycol, 1 ,2-propanediol, 1 ,3-propanediol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol,202400146 Foreign Filing 24neopentyl glycol, butylethyl-1 ,3-propanediol, methyl-1 ,3-propanediol, methylpentanediols, cyclohexanedimethanols, tricyclo[2.2.1]decanedimethanol, isomers of limonenedimethanol, trimethylolpropane and mixtures thereof.

7. The dispersion as claimed in at least one of claims 1 to 6, characterized in that at least one of the polyesters has a molecular mass of from 10,000 to 30.000 g / mol.

8. The dispersion as claimed in at least one of claims 1 to 7, characterized in that at least one of the polyesters has glass transition temperature TG of higher than 30 °C, preferably of from 40 to 70 °C.

9. The dispersion as claimed in at least one of claims 1 to 8, characterized in that at least one of the polyesters has an OH value of from 3 to 10 mg KOH / g, preferably 5 to 8 mg KOH / g.

10. The dispersion as claimed in at least one of claims 1 to 9, characterized in that at least one of the polyesters has an acid value of from 1 to 5 mg KOH / g, preferably 2 to 4 mg KOH / g.

11. The dispersion as claimed in at least one of claims 1 to 10, characterized in that at least one of the polyesters has a molecular mass of from 10,000 to 30.000 g / mol, a glass transition temperature TG of higher than 30 °C, preferably of from 40 to 70 °C, an OH value of from 3 to 10 mg KOH / g, preferably 5 to 8 mg KOH / g, and an acid value of from 1 to 5 mg KOH / g, preferably 2 to 4 mg KOH / g.

12. A process for the sealing of various types of substrates, characterized in that a foil is coated with a coating system comprising a dispersion as claimed in any of claims 1 to 11 , the coating is dried at a temperature of from 150 to 220°C, preferably at a temperature of from 170 to 190 °C, and the coated side of the foil is placed onto the material to be sealed, and is sealed at a temperature of from 150 to 220°C, preferably at a temperature of from 170 to 190°C and with a pressure of from 0.2 to 1.0 MPa, preferably 0.4 to 0.8 MPa, over a period of from 0.1 to 10 seconds, preferably of from 0.5 to 2.5 seconds.

13. A process according to claim 12, characterized in that the foil and the material to be sealed, both coming into contact with the coating system, are made from aluminum.

14. A heat-sealable coating system suitable for the sealing of various types of substrates, comprising a film-forming dispersion as claimed in any of claims 1 to 11.

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