In-line coated biaxially orientated polypropylene based antistatic multilayer films

[0001] The invention relates to the field of production and applications of plastics. More specifically, the invention relates to in-line coated or multilayer polyolefin films having improved surface properties, such as excellent anti-static, cold bonding, slipperiness, wetting voltage, printability and adhesion to various types of binders.

BACKGROUND OF THE INVENTION (BACKGROUND ART) It is known that many packaging materials of thermoplastic polymers, e.g. films, sheets, coatings, foams, etc. - showing adequate flexibility and mechanical strength, have a wide range of applications in the food and non-food industry, such as packaging food, agriculture, industrial wrapping, medicine, pharmacy, electrical and electronic materials industry etc.

[0003] These materials, especially packaging films, including bidirectional oriented polyolefin films, are required, among others, to: (1) had the required surface properties such as anti-static, wetting voltage, adequate adhesive and slipperiness during operation under various conditions, (2) retained their optical properties (fog, gloss, opacity, etc.) and thermal properties (weldability, etc.) (3) retained their tensile properties and mechanical properties required for specific applications.

[0004] Currently, antistatic films are made by incorporating additives as a masterbatch into the film during extrusion or by coating the film off-line after producing various types of organic antistatic additives such as ethoxylated amines, polyimines etc., containing positive ions in the particles to obtain conventional film-forming thermoplastic polymers, such as polyolefins, flexible poly (vinyl chloride), styrene polymers, polyesters, functional copolymers of α-olefins, etc.

[0005] There are a number of patent publications available for in-line coated thermoplastic films, antistatic thin polyolefin films, white cavitated sealable or non-heat sealable bidirectional oriented polypropylene films containing various types of organic and inorganic additives such as polyethylene glycol and its stearyl ether, monoester of fatty acid and polyhydric alcohol, fatty acid monoglyceride, alcohol esters and amides or metal salts of saturated or unsaturated monocarboxylic fatty acids, low and high molecular weight amine and imine compounds, inorganic fillers and pigments, silica and organic mold removal agents, etc. The conventional nonionic antistatic agents most commonly used in polyolefin film compositions are fatty acid esters, ethoxylated alkylamines, diethanolamides, and ethoxylated alcohol.

[0006] More specifically, a thermoplastic resin film laminate with anti-static properties, such as disclosed in US Patent 4605591, relates to a polyester film and a layer of polyester resin composition provided on at least one surface of the film, wherein the composition comprises (A) a water-insoluble polyester copolymer of a mixture of aliphatic or alicyclic dicarboxylic acids and their metal sulfonate derivatives (sulfophthalic acid and its iso-structural analogues) with C aliphatic glycols_2-8 and alicyclic glycols C_2-8 and (B) inert inorganic particles such as fine calcium carbonate, kaolin, bentonite, zeolite etc. (mass ratio (A) / (B) = 100 / 0.5-3.0); in terms of transparency and slipperiness, the use of natural and synthetic silicas is preferred in this invention. The composition also contained one or more ingredients selected from the group consisting of a water-soluble silicone, a multifunctional reactive compound, polyethylene glycol and its derivative (0.1-15 wt.%), And an antistatic agent. This film laminate is preferably produced by an in-line coating method.

[0007] This invention recommends the possibility of producing a laminate film using other non-polar thermoplastic polymers, especially polyolefins, but this method cannot be applied to polyolefins (polyethylene, polypropylene and α-olefin copolymers) because the surface of the films of said polymers is highly hydrophobic and the creation of thin coatings from the polar monomer system on their surface is not possible without preliminary surface treatment (corona discharge treatment, plasma, flame and chemical). The polyester film laminate of this invention is a hot stamped non-monolayer or multilayer, non-oriented or unidirectional oriented film, and the obtained laminate is then unidirectional or bi-directional oriented.

[0008] Patent EP 0505861 A2 discloses a laminated film comprising 3-300 pm polyester film and at least one 0.01-5.0 pm coating layer on one or both surfaces of this polyester film. The thin coating film contained (a) a polymer with a cationic nitrogen atom in the main chain, (b) a polymeric binder selected from the group consisting of polyesters, polyacrylates, polyurethanes, chlorine-containing polymers and mixtures thereof, (c) a material selected from the group consisting of particles, lubricants and mixtures thereof; and (d) a crosslinker selected from the group consisting of melamine or epoxy crosslinkers and mixtures thereof. The coating film was obtained by the in-line coating method. This laminated film is oriented in one or two directions, which is great for antistatic, adhesive and slippery properties. Patent EP 0172269 A2 discloses a thermoplastic resin copolyester film laminate comprising (A) a water-insoluble polyester copolymer which contained a mixture of a dicarboxylic acid component with a methanesulfonate group and a glycol component, and (B) inert particles; mass ratio (A) / (B) = 100 / 0.5-3.0. The film composition contained water-soluble silicone, a multi-functional reactive compound, polyethylene glycol and its derivative, and phosphoric (V) derivatives as anti-electrostatic agents. The copolyester film laminate is preferably made by in-line coating. According to patent EP 0362568A2, an antistatic polyester film is useful for various applications, such as magnetic information carriers, plastic arts, displays, packaging materials, building materials etc. Several patent publications concerned improving the adhesion between the surface of the base polymeric film and the surface of the coating by using different polymer compositions as coating solutions. Such coatings include compositions based on polyethyleneimine (US Patent 5,156,904), acrylic or methacrylic thermosetting plastics (US Patent 4,571,363), cross-linked styrene and maleic anhydride copolymer (US patent 4,410,600), vinylidene chloride copolymer (US patent 2,698,240), water dispersible copolymers (US Patent 5,156,904) and similar polymeric coatings. Of these coatings, polyethyleneimine is the most commonly used coating component between various ionomeric and non-ionomeric thermoplastic films, such as polyester or cellophane / polyethylene (US Patent No. 28554), polypropylene / other polymers (US Patent 4,139643) and similar polymeric systems. Oriented polymeric films, preferably polyethylene terephthalate, coated with polyethyleneimine and / or polyamide polyethyleneimine are disclosed in US patents 5,156,904 and 5,453,326, respectively, in which polyethyleneimine is applied in an in-line system, i.e. during the production process of the film, the polymer film before thermosetting of the foil. In-line coated films when used to prepare laminate with other polymers, such as polyethylene or ionomeric polymers, showed no signs of delamination of the base polymer film and extrusion coated polymer after 2 hours in 121 ° C water at 0 ° C , 1 N / mm² (US Patent 5,156,904 and EP Patent 0458147A2). Oriented polyethylene terephthalate film is coated in an in-line polyamide-polyethyleneimine system to improve the anti-static properties of the film and its use for other packaging applications (US Patent 5,453326). An in-line polyethyleneimine coated film is used to produce a laminate with another nonionic or ionomeric type of polymer, such as polyethylene or polyester, preferably polyethylene terephthalate (Patent EP 0458147A2). However, the above inventions relate to the preparation of a laminated film using only single-matrix matrix polymer film and a group of polymeric antistatic agents comprising cationic nitrogen-containing polymer complexes, preferably water-soluble polyethyleneimine, with HCl or HBr acids. However, it is well known that the use of inorganic acid components in polyethyleneimine complexes causes some difficulties during processing, such as corrosion of metal components of the devices and problems with environmental protection, because these components evaporate during the film making process.

[0009] It is well known that many acrylic and methacrylic polymers [Maltzer YL Water-soluble polymer, Noves Data Co .: New Jersey, USA, 1981] and copolymers of maleic anhydride and its isostructural analogues (anhydrides, amides, esters, and citraconic imides and itaconic) [Triverdi BC, Culberton BM Maleic anhydride, Plenum Press: New York, 1982; Rzaev ZMO Polymers and copolymers of maleic anhydride, Elm: Baku, 1984; Rzaev ZMO Prog. Polym. Sci., 2000; 25: 163; Rzaev Z. MO et al. Eur. Polym. J. 2002; 38: 2143] is commonly used as an effective ingredient in water-soluble or dispersed film-forming compositions that are also suitable for the production of surface coatings on various thermoplastic polymers, preferably on polar polymeric systems using in-line coating. For example, US Patent 4410600 discloses a bi-directionally oriented aromatic polyester film coated in an in-line process cross-linked poly (styrene maleic anhydride) functional copolymer prior to thermosetting; said coated copolymer film still requires corona discharge treatment through the converter before extrusion coating. A number of publications regarding the use of said water-soluble functional polymeric film-forming systems for coating the surface of a polyolefin film is severely limited to the use of (meth) acrylic type polymer compositions, while almost no publication, including patent publications, for anhydride-containing copolymers and their various compositions .

[0010] Several Japanese patent publications also concerned coated thermoplastic polymers, preferably polyester type polymers, in which an antistatic layer is applied to at least one surface of the base film. An anti-electrostatic resin obtained by copolymerization of the polyalkylene oxide component with a component containing a quaternary ammonium group was used. The antistatic coating is stressed at least in one direction (JP

2003- 136641). JP 2002-012858 discloses a method of improving the antistatic properties of a thermoplastic film by the use of an antistatic agent that inhibits the excellent antistatic behavior in low humidity conditions, capable of providing an electrostatic film excellent in terms of shade and antistatic film of the coating type, as well as a method of obtaining an antistatic film of the coating type by coating method in-line system. The antistatic agent contained (1) a compound containing sulfonic acid or a salt thereof and (2) a polymer containing a cationic group. The object of another patent (JP 2001-026088) is to improve adhesion, printability and other features by providing a layer of easily wettable coating film on one surface of a polyester film and setting the wetting voltage of the other surface of the polyester film to a certain value (45 mN / m or more). As a method of producing a coating film layer, an in-line coating method is given in which the coating agent is applied to the polyester film prior to orientation / crystallization and the coating layer is stretched at least in one direction to produce a coated film preferably 0.001-1.0 thick pm. Patent invention (JP

2004- 345298) discloses a polyester film for shrink packaging that is excellent in solvent binding properties and has sufficient solvent binding properties even after the application of an antistatic coating film in an in-line coating method. JP 5320391 relates to easily coated polyester with improved electrostatic properties and is characterized by the placement of a primer layer containing a composition containing (1) an easily adhesive polyester resin, (2) an antistatic agent containing in the molecule a sulfonic acid group and / or a group of its metal salt salt and (3) an acid compound with at least one carboxyl group or phenolic hydroxyl group on at least one side of the polyester film and a method of producing this film by a method in-line coating. The object of the invention JP 6293875 is to obtain a coating agent with excellent sliding properties and resistance to mutual sticking to a copolyester film, and showing adhesion to various coating materials by mixing a water-soluble copolyester and acrylic resin. This invention provides a polyester film coated with a coating agent dispersed in water and a method for producing this film by in-line technique. JP 6099559 has disclosed a polyester film useful as a base film for example a film coated product such as a magnetic information carrier, photographic x-ray film, telephone card, diaphragm microfilm, etc., with excellent adhesive properties, resistance to mutual sticking and smoothness. This polyester-based film consists of a coating layer made of dispersible or water-soluble acrylic resin, fine inorganic particles (size 0.2 pm). The coating layer of this film is obtained by in-line coating. Tsunashima et al. (Toray Ind.) (JP 11198228) developed an in-line coating method for water-soluble coating materials or the like, characterized by good performance and quality ensuring no thickness irregularities in the film making process, and also allowing bi-directional formation oriented film with an orientation speed of 10 ± 4% / min or more in both the longitudinal and transverse directions. The oriented film obtained by this method comprises a layer of 0.0050.5 pm thick coating material on the surface of the film.

[0011] However, these inventions mainly included polyester-type base polymers and adhesive polyester or acrylic resin, and the films obtained are not single-layer or multi-layer. No method, including those developed in the said patents, is suitable for hydrophobic polyolefin films, especially for single- or multi-layer and bidirectionally oriented polypropylene films. On the other hand, all patent information about polypropylene-based film laminates and acrylic compositions characterized by a combination of useful properties, such as excellent anti-electrostatic properties, facilitating separation of the mold from the mold, physical and mechanical properties and other important parameters are limited by information on the nature of proposals without detailed experimental results and technological research of prototypes.

[0012] As can be seen from the patent publications described above, there are a relatively small number of publications describing polyolefin-based films, especially in-line coated films. All patent publications have one or more of the following disadvantages: the film compositions are not single or multilayer, are not bi-directional oriented and based on polypropylene, are not weldable or cavitated or dyed with a combination of excellent anti-electrostatic properties facilitating the separation of the mold from the mold , slipperiness, improved wetting voltage, cold welding and sticking etc. that would be retained for a long time.

BRIEF DESCRIPTION OF THE DRAWINGS [0013]

FIG. 1 shows a scheme for the production of self-ordered hyperbranched macro-complexes with a positive charge as effective antistatic agents.

FIG. 2 shows a general diagram of the technology for the production and processing of the disclosed films with a changed and improved in-line chemical coating system.

SUMMARY OF THE INVENTION [0014] The object of the invention is to design and obtain a multilayer structure, preferably an A / B / C / D / E structure having at least a thin epidermal antistatic coating (A), two inner layers (B) and (D), a core layer (C) and the outer layer (E) for bi-directionally oriented polyolefin-based films, preferably polypropylene, exhibiting beneficial properties such as anti-electrostatic properties, facilitating mold separation, slipperiness, cavitation, heat sealability and improved wetting tension, compared to known and commercially available polypropylene based films of similar composition. In order to improve the antistatic properties of the film, the epidermal coating composition (A) contains a mixture of an acrylic polymer matrix or crosslinkable copolymers of maleic anhydride and its isostructural analogues, and an ionic antistatic agent based on complex two-component systems, such as linear or branched polyethyleneimine (PEI) / copolymers of oligo (acrylic) and (meth) acrylic acid or PEI / water-soluble copolymers of maleic anhydride [poly (MA-co-comonomer) with various comonomers, preferably with ethylene, propylene, N-isopropylacrylamide, N-vinyl-2-pyrrolidone and the like comonomers (Fig. 1), a polypropylene homopolymer, a donor-acceptor or hydrogen bond in the combination of two-component systems used in the composition of said layer provides a significant increase in the positive charge in the primary, secondary and tertiary amine groups, and thus exhibiting excellent anti-electrostatic properties. It is a known fact that copolymers containing hydrolyzed anhydride with a strong hydrogen bond structure easily form complex macrocomplexes with PEI through non-covalent -COO interaction^-- + NH- between free carboxyl groups of the acid part and PEI amino groups (Rzaev ZMO et al. J Appl. Polym. Sci. 2007; 102: 5841) The two inner layers (B) and (D) of said single or multilayer structure contain 100% polypropylene or a mixture of polypropylene with a poly (ethylene-co-propylene) copolymer or a poly (ethylene-co-propylene- co-butylene) or polypropylene, a TiO2 white masterbatch for producing white BOPP film, a slip / antistatic masterbatch and a CaCO3 masterbatch for producing white cavitated BOPP film. The core layer (C) of similar composition as layers (B) and (D) contains polypropylene or a slip / nonionic antistatic masterbatch and CaCO3 or TiO2 white masterbatch. The outer layer (E) contains polypropylene or poly (ethylene-co-propylene) copolymer or poly (ethylene-co-propylene-co-butylene) terpolymer, silica masterbatch and organic agent that facilitates mold separation and a non-ionic anti-electrostatic masterbatch . The outer layer (E) can be corona, plasma or flame treated, or it may not be processed depending on the end use of the film. The compositions of the compositions and layer components for the various types of polypropylene films coated with the invention are set forth in the examples and tables below.

[0015] Other polypropylene based multilayer films are known from WO 99/07553 and TR 2000 02164 A2.

[0016] The invention is a coated antistatic film that is multilayer, bi-directionally oriented and made of polyolefin, preferably polypropylene and poly (ethylene-co-propylene-co-butylene) terpolymers [poly (E-co-P-co-B) ] with different contents of E and B units. A thin coating with a thickness of about 0.05-2.0 pm is made of (a) a mixture of an acrylic polymer matrix or polyethylene glycol cross-linked (PEG) copolymers of maleic anhydride and its isostructural analogues and an ionic antistatic agent based on complex two-component systems, such as linear or branched polyethyleneimine (PEI) / copolymers of oligo (acrylic) and (meth) acrylic acid or PEI / water-soluble copolymers of maleic anhydride [poly (MA-co-comonomer) with various comonomers, preferably with ethylene, propylene, N-isopropylacrylamide, N-vinyl-2-pyrrolidone and the like, and (b) one of conventional acrylic adhesive compositions (Rogers Int. Inc., Greenville, SC, USA) modified with said two-component complex system as an antistatic agent. Antistatic coated multilayer films of the invention are made using improved in-line production, processing and coating technology. The invention is useful for food packaging and agricultural applications as well as for other general packaging applications and unconventional special applications.

[0017] The following are examples of the invention for the preparation of multilayer and antistatic coated polypropylene films of various compositions and properties.

EXAMPLE 1 [0018] The first example of an in-line multi-layer film (A / B / C / D / E) coated with excellent anti-electrostatic properties includes: (A) a 0.1 pm surface treated with corona discharge and applied in an in-line system 0.9 pm on the surface of the epidermal layer containing 90% by mass propylene homopolymer, 10% by mass mixtures of acrylic polymer matrix and ionic antistatic agent based on complex two-component systems, such as linear or branched polyethyleneimine PEI [LPEI or (BPEI) / oligo (acrylic acid)], (B) 2.0 pm inner layer containing 100% by mass polypropylene, (C)

22.0 pm core layer containing 100% mass polypropylene, (D) 2.0 pm inner layer containing 100 wt. polypropylene, (E) 1.0 pm outer layer with corona discharge surface, containing 98.5 mass% polypropylene. Before bidirectional stress and in-line coating, the epidermal layer (A) is corona or flame treated twice to ensure better adhesion of the polypropylene polymer matrix surface to the in-line acrylic coated system. The outer layer (E) is also corona or flame treated for later printing and labeling. The film is obtained by using a twin screw extruder system with a flat expander with excellent mixing and simultaneous or sequential tensioning function, equipped with a cooled corona discharge system and an improved in-line coating system for the effective modification / hydrophilization of the film surface, three or four satellite coextruding extruders, flat jaw, cooling drum and water evaporation and recycling lines.

EXAMPLE 2 [0019] A second example of an in-line multilayer film (A / B / C / D / E) coated with excellent anti-electrostatic properties includes: (A) a 0.1 pm surface treated with corona discharge and applied in an in-line system 0.9 pm on the surface of the epidermal layer containing 90% by mass propylene homopolymer or poly (ethylene-co-propylene-co-butylene) terpolymer, 10% by mass mixtures of acrylic polymer matrix and ionic antistatic agent based on complex two-component systems, such as linear or branched polyethyleneimines PEI [LPEI or (BPEI) / oligo (acrylic acid)], (B) 3.0 pm internal layer containing 85% by mass polypropylene, 15% by mass TiO white pigment₂, (C) 30 pm core layer containing 85 wt. polypropylene homopolymer, 15% by mass CaCO cavitation masterbatch₃, (D) 3.0 pm inner layer containing 95% by mass polypropylene, 5% by mass TiO white pigment₂ and (E) 1.0 pm outer layer treated with corona discharge, containing 100% by mass. polypropylene or poly (ethylene-co-propylene-co-butylene) terpolymer. Before bi-directional stress and in-line coating, the epidermal layer (A) is corona or flame treated twice to ensure better adhesion of the polypropylene polymer matrix surface to the in-line acrylic coated system. The outer layer (E) is also corona or flame treated for later printing and labeling. The film is obtained by using a twin screw extruder system with a flat expander with excellent mixing and simultaneous or sequential tensioning function, equipped with a cooled corona discharge system and an improved coating system in-line for the needs of effective modification / hydrophilization of the film surface, three or four satellite coextruding extruders, flat jaw, cooling drum and water evaporation and recycling lines.

EXAMPLE 3 [0020] A third example of an in-line multilayer film coated structure having the same composition and thickness as in Example 1 with the following changes: an in-line skin layer (A) 1.0 pm thick contains 10% mass mixtures of crosslinkable copolymers of maleic anhydride and an ionic antistatic agent based on complex two-component systems such as linear or branched polyethyleneimine (LPEI or BPEI / oligo (acrylic acid) with an average molecular weight (Mn) equal to or greater than 480 g / mol or 2000 g, respectively /moth.

EXAMPLE 4 [0021] A fourth example of an in-line multilayer film coated structure having the same composition and thickness as in Example 1 with the following changes: the in-line coated epidermal layer (A) contains 10 wt. mixtures of PEI / water-soluble maleic anhydride copolymers with an equivalent average molecular weight unit (M) / carboxylic acid ratio (M_n) equal to or greater than 10,000 g / mol.

EXAMPLE 5 [0022] A fifth example of an in-line multi-layer film contains a structure with the same composition and thickness as in Example 1 with the following changes: an in-line skin layer (A) 1.0 pm thick contains 10% mass mixtures of PEI / methacrylic copolymer with an equivalent ratio of amine unit / carboxylic acid with an average molecular weight (Mw) equal to or greater than 1500 g / mol.

EXAMPLE 6 [0023] A sixth example of an in-line multilayer film coated structure having the same composition and thickness as in Example 1 with the following changes: (A) 0.1 pm corona-treated surface and applied in an in-line system 0.9 pm on the surface of the epidermal layer containing 90% by mass n-propylene monopolymer, 10% by mass mixtures of acrylic polymer matrix and ionic antistatic agent based on complex two-component systems, such as linear or branched polyethyleneimine PEI [LPEI or (BPEI) / oligo (acrylic acid)], core layer (C) 24 pm thick contains 85% by mass propylene homopolymer and 15% by mass TiO white pigment₂. E) 1.0 pm outer layer with corona treatment surface contains 100% by mass. polypropylene or poly (ethylene-co-propylene-co-butylene) terpolymer.

COMPARATIVE EXAMPLE [0024] A comparative example of an in-line multilayer film (A / B / C / D / E) coated with excellent anti-electrostatic properties includes: (A) a 1.0 pm epidermal layer containing 98.5 wt. propylene homopolymer and 1.5% by mass

polypropylene masterbatch facilitating separation of the compact from the mold (containing 5% silica inorganic additive) (B) 2.0 pm inner layer containing 100% by mass. polypropylene, (C) 22.0 pm core layer containing 98 wt. polypropylene and 2% by mass anti-electrostatic polypropylene masterbatch (containing

15% additive - ethoxylated amine), (D) 2.0 pm inner layer containing

100% mass polypropylene, (E) 1.0 pm outer layer with corona treatment surface, containing 97.5 wt. polypropylene and 2.5% by mass polypropylene masterbatch to facilitate mold separation (containing 5% silica inorganic additive). Before bidirectional stress and in-line coating, the epidermal layer (A) is corona or flame treated twice to ensure better adhesion of the polypropylene polymer matrix surface to the in-line acrylic coated system. The outer layer (E) is also corona or flame treated for later printing and labeling. The film is obtained by using a twin-screw extruder system with a flat expander with excellent mixing and simultaneous or sequential tensioning function, equipped with a cooled corona discharge system and three or four satellite co-extruders, flat jaw, cooling drum and water evaporation and recycling lines.

TABLE 1

<td colspan="8">Composition of coated films in an in-line system according to the invention.</td>

<td rowspan="2">individual ingredients</td><td>Ex-1</td><td>Ex-2</td><td>Ex-3</td><td>Ex-4</td><td>Ex-5</td><td>Ex-6</td><td>Comparative foil</td>

<td>Content (mass%)</td><td>Content (mass%)</td><td>Content (mass%)</td><td>Content (mass%)</td><td>Content (mass%)</td><td>Content (mass%)</td><td>Content (mass%)</td>

<td>polypropylene isotactic (Homopolymer)</td><td> 99,635</td><td> 85,334</td><td> 99,635</td><td> 99,635</td><td> 99,635</td><td> 84,926</td><td> 99,745</td>

<td>Poly [ethylene-propylenoko (1,25,4%) - co-1-butene (2,814,6%)]</td><td> 0,000</td><td> 5,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 6,333</td><td> 0,000</td>

<td>Calcium carbonate - cavitation agent</td><td> 0,000</td><td> 8,289</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td>

<td>Titanium dioxide - a white pigment</td><td> 0,000</td><td> 1,105</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 8,400</td><td> 0,000</td>

<td>Tetrakismetane - an antioxidant</td><td> 0,004</td><td> 0,004</td><td> 0,004</td><td> 0,004</td><td> 0,004</td><td> 0,004</td><td> 0,004</td>

<td>Aryl phosphide - stabilizer</td><td> 0,004</td><td> 0,004</td><td> 0,004</td><td> 0,004</td><td> 0,004</td><td> 0,004</td><td> 0,004</td>

<td>Silica agent facilitating separation of the compact from the mold</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,007</td>

<td colspan="8">Composition of coated films in an in-line system according to the invention.</td>

<td>Additive based on ethoxylated amine</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,240</td>

<td>Coating Material 1</td><td> 0,357</td><td> 0,263</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,333</td><td> 0,000</td>

<td>Shell material 2</td><td> 0,000</td><td> 0,000</td><td> 0,357</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td>

<td>Shell material 3</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,357</td><td> 0,000</td><td> 0,000</td><td> 0,000</td>

<td>Shell material 4</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,000</td><td> 0,357</td><td> 0,000</td><td> 0,000</td>

<td colspan="8">Coating material 1: a mixture of acrylic polymer matrix and ionic antistatic agent based on complex two-component systems, such as linear or branched polyethyleneimine PEI [LPEI or (BPEI) / oligo (acrylic acid)] Shell material 2: a mixture of crosslinkable copolymers of maleic anhydride and an ionic antistatic agent based on complex two-component systems, such as linear or branched polyethyleneimine (LPEI or BPEI / oligo (acrylic acid) with average molecular weight (M_n) equal to or greater than 480 g / mol or 2000 g / mol, respectively. Coating material 3: a mixture of PEI / water soluble maleic anhydride copolymers with an equivalent average molecular weight (M) / carboxylic acid ratio (M_n) equal to or greater than 10,000 g / mol. Coating material 4: PEI / methacrylic copolymer mixture with an equivalent ratio of the amine unit / carboxylic acid average molecular weight (M_in) equal to or greater than 1500 g / mol.</td>

TABLE 2

<td colspan="8">Composition of layers included in various types of multilayer BOPP films according to the invention</td>

<td>layers</td><td>EXAMPLE 1 (28 pm) In-line non-welded BOPP film</td><td>EXAMPLE 2 (38 pm) In-line coated cavitated opaque BOPP film</td><td>EXAMPLE 3 (28 pm) In-line non-welded BOPP film</td><td>EXAMPLE 4 (28 pm) In-line non-welded BOPP film</td><td>EXAMPLE 5 (28 pm) In-line non-welded BOPP film</td><td>EXAMPLE 6 (30 pm) White heat-sealable BOPP film</td><td>FOIL COMPARATIVE (28 pm) Non-weldable BOPP film</td>

<td>Layer epidermal</td><td>homopolymer 90% Coating Material 1 10% (thickness: 1 pm)</td><td>90% terpolymer Coating Material 1 10% (thickness: 1 pm)</td><td>homopolymer 90% Shell material 2 10% (thickness: 1 pm)</td><td>homopolymer 90% Shell material 3 10% (thickness :) 1 pm)</td><td>homopolymer 90% Shell material 4 10% (thickness: 1 pm)</td><td>90% terpolymer Shell material 1 10% (thickness: 1 pm)</td><td>Homopolymer 98.5% The master batch making it easier to separate moldings from the mold 1.5% (thickness: 1 pm)</td>

<td>Layer inside</td><td>homopolymer 100% (thickness: 2 pm)</td><td>85% homopolymer White (TiOi) Masterbatch 15% (thickness: 3 pm)</td><td>homopolymer 100% (thickness: 2 pm)</td><td>homopolymer 100% (thickness: 2 pm)</td><td>homopolymer 100% (thickness: 2 pm)</td><td>homopolymer 100% (thickness: 2 pm)</td><td>100% homopolymer (thickness: 2 pm)</td>

<td>Layer core</td><td>homopolymer 100% (thickness: 22.0 P^m)</td><td>85% homopolymer Cavitation masterbatch (CaCO₃) 15% (thickness: 30 pm)</td><td>homopolymer 100% (thickness: 22.0 P^m)</td><td>homopolymer 100% (thickness: 22.0 P^m)</td><td>homopolymer 100% (thickness: 22.0 P^m)</td><td>homopolymer 85% White masterbatch (T1O2) 15% (thickness: 24.0 pm)</td><td>Homopolymer 98% Antistatic masterbatch 2% (thickness: 22.0 pm)</td>

<td colspan="8">Composition of layers included in various types of multilayer BOPP films according to the invention</td>

<td>Layer inside</td><td>homopolymer 100 % (thickness: 2 pm)</td><td>Homopolymer 95% White masterbatch (T1O2) 5% (thickness: 3 pm)</td><td>homopolymer 100% (thickness: 2 pm)</td><td>homopolymer 100% (thickness: 2 pm)</td><td>homopolymer 100% (thickness: 2 pm)</td><td>homopolymer 100% (thickness: 2 pm)</td><td>100% homopolymer (thickness: 2 pm)</td>

<td>Layer outside</td><td>homopolymer 100% (thickness: 1 pm) Surface treatment: corona discharge or flame</td><td>100% terpolymer (thickness: 1 pm) Surface treatment: corona discharge or flame</td><td>homopolymer 100% (thickness: 1 pm) Surface treatment: corona discharge or flame</td><td>homopolymer 100% (thickness: 1 pm) Surface treatment: corona discharge or flame</td><td>homopolymer 100% (thickness: 1 pm) Surface treatment: corona discharge or flame</td><td>100% terpolymer (thickness: 1 pm) Surface treatment: corona discharge or flame</td><td>Homopolymer 97.5% The master batch making it easier to separate the molded part from the mold 2.5% (thickness: 1 P^m)Surface treatment: corona discharge or flame</td>

[0025] The thickness of the epidermal surface layer coated in the in-line antistatic acrylic / maleic film system developed in the invention is equal to or greater than 0.8 pm, the thickness of the coating applied in the in-line system is equal to or less than 0.5 pm as in examples 1-6.

[0026] One aspect of this disclosure is the possibility of producing films in the form of uni- and bidirectionally oriented polyolefins, preferably uni- and bidirectionally oriented polypropylene films with at least one surface coated with an anti-electrostatic adhesive layer by using a combination of:

a) twin screw extruder system with flat expansion with excellent mixing and simultaneous or sequential tensioning function, one main extruder with three or four satellite co-extruders, flat jaw, cooling drum and water bath, machine and cross-orientation units, recycling line, recycling equipment corona discharge or flame treatment, winding device.

b) a built-in coating system equipped with tensioning pulleys, a coating roller, dual cooled corona discharge devices and a water evaporation line for effective surface modification / hydrophilization and to significantly improve the antistatic and wetting tension of the film.

[0027] The film extrusion line with flat expander is a line producing conventional bi-directionally oriented polypropylene films with industrially acceptable properties. However, this technology does not allow the production of films with improved and long-term slipperiness, anti-electrostatic properties, wetting voltage, optical properties, etc. When using a conventional traveling additive containing masterbatches, these properties change as a result of aging and exploitation. [0028] According to this disclosure, an improved version of the in-line coating system developed and embedded in a standard bi-directionally oriented polypropylene production and processing line on a flat expander serves to implement the following important changes in the in-line coating treatment:

1) Taking into account that the polypropylene surface is hydrophobic and has lower wetting voltage values ​​(29-31 dyne / cm) compared to the polyester surface, which has a higher wetting voltage value (40-42 dyne / cm) commonly used in in-line coating technology, dual cooled corona discharge devices are used in the in-line coating system to provide a level of wetting pressure on the polypropylene film surface sufficient to allow water-based coatings to adhere to the surface.

2) In standard BOPP production processes, the voltage between MDO and TDO is carefully controlled to avoid film breakage and poor product quality. In contrast, the in-line coating apparatus located between them causes an increase in stress and inaccurate voltage control. Therefore, the bearing system of the last MDO rollers was changed and a new control system was built into the system to obtain accurate voltage control.

3) It is well known that polypropylene elements have lower heat resistance compared to polyester elements. Therefore, in the BOPP film processing system for corona discharge, the heat generated during the discharge should be dissipated by the cooling rollers. Since the corona discharge power used in the in-line coating method is about 30-40 kW, the discharge rollers adapted to the in-line coating system are cooled with an additional cooling system to avoid film overheating.

4) It is also well known that the most important parameters in the in-line coating system include obtaining a homogeneous and even thickness distribution throughout the network, since MDO film must be tensioned TDO in a ratio of 1: 8 to 1:10, the thickness of the coating should be controlled in a very sensitive control device. Therefore, a new device is installed in the in-line coating system to control the thickness of the coating using a p-gauge or X-rays.

5) The coating roll pattern is different for the polyester substrate and different for the polypropylene substrate. In the case of the film of the invention, during coating in in-line systems a different production cell angle, linearity (number₂ socket / inch²) and the volume of the production well, depending on the composition and concentration of the coating material.

6) The dryer, in this case the TDO heating section, must have sufficient heat output to dry and remove water from the coated film. To achieve the desired drying temperature of 180-190 ° C (in the case of linear coating) instead of 160-170 ° C (in the standard production without coating), the heat efficiency of the TDO heating section is increased.

[0029] According to the disclosure, the technological aspects of the production and processing of said films are as follows:

a) bi-directional oriented monolayer or multilayer polypropylene film technology;

b) twin-screw extrusion system with flat expansion with excellent mixing and simultaneous or sequential tensioning function, one main extruder with three or four satellite co-extruders, flat jaw, cooling drum and water bath, machine and cross-orientation units, recycling line, recycling equipment corona discharge or flame treatment, winding device;

c) built-in coating system equipped with tensioning pulleys, coating roller, double cooled corona discharge devices and water evaporation line for the purpose of effective surface modification / hydrophilization and to significantly improve the antistatic and wetting tension of the film.

[0030] Alternatively, the outer layer (E) of the bi-directionally oriented films obtained may be treated by a known method such as plasma or flame or more preferably by an electric corona. A general diagram of the production technology and improved film processing is shown in Figure 2.

[0031] Another aspect of the invention is the use of new functional copolymer systems as base polymers, i.e. water-soluble anhydride-containing copolymers and their PEI macrocomplexes in coating compositions and polymeric anti-electrostatic agents; linear and branched PEIs have the following average parameters: average molecular weight M_n = 425 g / mol, viscosity η = 200 cP in ₃ temp. 25 ° C and density d = 1.07 g / cm (in the case of linear PEI) and M_n = 1800, M_in = ₃

2000 g / mol and density d = 1.08 g / cm (in the case of branched PEI). The copolymers containing anhydride and homo- and copolymers of (meth) acrylic acid are easily cross-linked with polyethylene glycol (PEG) in an aqueous medium at 85-110 ° C without any catalyst and at room temperature against a water-soluble carbamide type catalyst (as in Devrim Y., Rzaev ZMO et al. Macromol. Chem. Phys. 2007; 208: 175). The physical state of the PEG used varies from liquid to crystalline powder; having different molecular weights (M_n = 200, 420, 950 and 8000 g / mol) are used as a cross-linking agent whose intermolecular bonds also improve the antistatic properties of the film. Both of these cross-linkable copolymer systems as well as hyperbranched copolymer / PEI macrocomplexes (Figure 1) show better film-forming properties and excellent anti-electrostatic properties respectively. Conventional acrylic adhesives can also be used for the in-line coating process.

[0032] A further object of the invention is to broaden the field of application of said coated films useful for conventional applications, including in the food and non-food industry, such as food packaging, agriculture, industrial wrapping, medicine, pharmacy, electrical and electronic materials industry etc.

[0033] Some important properties of the films obtained according to the invention are summarized in Table 3.

Table3

<td colspan="15">Physical and mechanical parameters and surface properties of multilayer BOPP films according to the invention</td>

<td>Method test</td><td>parameters</td><td colspan="2">Unit</td><td colspan="2">EXAMPLE 1 (28 pm) Non-welded BOPP film coated in inline system</td><td colspan="2">EXAMPLE 2 (38 pm) In-line coated cavitated opaque BOPP film</td><td colspan="2">EXAMPLE 3 (28 pm) Non-welded BOPP film coated in inline system</td><td colspan="2">EXAMPLE 4 (28 pm) Non-welded BOPP film coated in inline system</td><td>EXAMPLE 5 (28 pm) Non-welded BOPP film coated in inline system</td><td>EXAMPLE 6 (30 pm) White Weldable BOPP film</td><td>COMPARATIVE FOIL (28 pm) Non-weldable BOPP film</td>

<td>ASTM D 374</td><td>Thickness</td><td colspan="2">pm</td><td colspan="2"> 28</td><td colspan="2"> 38</td><td colspan="2"> 28</td><td colspan="2"> 28</td><td> 28</td><td> 30</td><td> 28</td>

<td>ASTM D 4321</td><td>Performance</td><td colspan="2">m²/ kg</td><td colspan="2"> 39,2</td><td colspan="2"> 39,3</td><td colspan="2"> 39,2</td><td colspan="2"> 39,2</td><td> 39,2</td><td> 34</td><td> 39,2</td>

<td>ASTM D 1505</td><td>Density</td><td colspan="2">g / cm³</td><td colspan="2"> 0,91</td><td colspan="2"> 0,67</td><td colspan="2"> 0,91</td><td colspan="2"> 0,91</td><td> 0,91</td><td> 0,98</td><td> 0,91</td>

<td colspan="14">SURFACE AND OPTICAL PROPERTIES</td><td></td>

<td>ASTM D 2578</td><td colspan="2">Wetting voltage</td><td colspan="2">dynes / cm</td><td colspan="2"> 42</td><td colspan="2"> 42</td><td colspan="2"> 42</td><td> 42</td><td> 42</td><td> 42</td><td> 38</td>

<td>ASTM D257</td><td colspan="2">Static decay period</td><td colspan="2">s</td><td colspan="2"> 0*</td><td colspan="2"> 0*</td><td colspan="2"> 0*</td><td> 0*</td><td> 0*</td><td> 0*</td><td> 195**</td>

<td>ASTM D 1003</td><td colspan="2">fog</td><td colspan="2"> %</td><td colspan="2"> 0,4</td><td colspan="2"> -</td><td colspan="2"> 0,4</td><td> 0,4</td><td> 0,4</td><td> -</td><td> 1,6</td>

<td>ASTM D 2457</td><td colspan="2">Shine</td><td colspan="2"> %</td><td colspan="2"> 100</td><td colspan="2"> 90</td><td colspan="2"> 100</td><td> 100</td><td> 100</td><td> 55</td><td> 85</td>

<td>DIN 53146</td><td>Opacity</td><td colspan="2"> %</td><td> -</td><td> 75</td><td> -</td><td> -</td><td> -</td><td> 65</td><td> -</td>

<td>ASTM D 1746</td><td>Passage light</td><td colspan="2"> %</td><td> -</td><td> 30</td><td> -</td><td> -</td><td> -</td><td> 35</td><td> -</td>

<td colspan="10">MECHANICAL AND HEAT PROPERTIES</td><td></td>

<td rowspan="2">ASTM D 882</td><td rowspan="2">Tensile strength</td><td rowspan="2">N / mm²</td><td>MD</td><td> 165</td><td> 79</td><td> 173</td><td> 169</td><td> 172</td><td> 148</td><td> 166</td>

<td>TD</td><td> 298</td><td> 137</td><td> 287</td><td> 293</td><td> 305</td><td> 227</td><td> 306</td>

<td rowspan="2">ASTM D 882</td><td rowspan="2">Elongation at break</td><td rowspan="2"> %</td><td>MD</td><td> 155</td><td> 98</td><td> 167</td><td> 162</td><td> 174</td><td> 166</td><td> 159</td>

<td>TD</td><td> 58</td><td> 40</td><td> 62</td><td> 59</td><td> 55</td><td> 63</td><td> 59</td>

<td rowspan="2">ASTM D 2732</td><td rowspan="2">Contractility Thermal</td><td rowspan="2"> %</td><td>MD</td><td> 4</td><td> 3</td><td> 4</td><td> 4</td><td> 4</td><td> 3</td><td> 4</td>

<td>TD</td><td> 2</td><td> 1</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td><td> 2</td>

<td>ASTM F 88</td><td>Weldability Range</td><td>° C</td><td> -</td><td> -</td><td> -</td><td> -</td><td> -</td><td> -</td><td> 105-145</td><td> -</td>

<td colspan="11">* 0 means that the electrostatic charge on the surface of the coated film discharges immediately and does not accumulate on the surface. The same values ​​are measured after manufacture and after 10 days of aging. ** the comparative film contains a traveling antistatic agent and this value was measured after 10 days of aging.</td>

[0034] Examples and comparative film were tested for wetting tension and adhesion to water-based inks and ultraviolet inks, since both ink systems are widely used in the industry and ordinary BOPP films exhibit insufficient adhesion with these ink systems.

Table 4

Ink adhesion test results (ink adhesion: 1-5, with "5" being the best)

<td rowspan="2">Foil type</td><td colspan="2">WB FLEXO INK</td><td colspan="2">UV FLEXO INK</td>

<td>Immediately</td><td>After 24 hours</td><td>Immediately</td><td>After 24 hours</td>

<td>Examples 1, 2 and 6</td><td> 5</td><td> 5</td><td> 1</td><td> 1</td>

<td>Example 3</td><td> 4</td><td> 5</td><td> 1</td><td> 2</td>

<td>Example 4</td><td> 4</td><td> 5</td><td> 1</td><td> 1</td>

<td>Example 5</td><td> 4</td><td> 5</td><td> 1</td><td> 1</td>

<td>Comparative foil</td><td> 2</td><td> 3</td><td> 0</td><td> 0</td>

<td rowspan="2">Foil type</td><td colspan="2">UV OFFSET INK</td><td colspan="2">UV LETTERPRESS INK</td>

<td>Immediately</td><td>After 24 hours</td><td>Immediately</td><td>After 24 hours</td>

<td>Examples 1, 2 and 6</td><td> 4</td><td> 4,5</td><td> 3</td><td> 3,5</td>

<td>Example 3</td><td> 3</td><td> 4</td><td> 2</td><td> 2,5</td>

<td>Example 4</td><td> 4</td><td> 4</td><td> 3</td><td> 3</td>

<td>Example 5</td><td> 3</td><td> 3,5</td><td> 2</td><td> 3</td>

<td>Comparative foil</td><td> 1</td><td> 3</td><td> 1</td><td> 1,5</td>

[0035] Another aspect of the invention is the use of various combinations of organic and inorganic additives to enable the production of various types of bi-directional oriented and coated single- or multilayer polypropylene films, such as transparent non-heat sealable, transparent non-sealable for labels, white cavitated non-sealable, white welded cavitated etc. . using the above described improved version of the technology for the production and processing of single or multi-layer thin coated and antistatic foils, including chemical modification of the film surface by in-line coating.

[0036] The advantages of the acrylic / maleic antistatic films disclosed in this invention and their manufacturing and processing technologies are:

(1) the complex structure of macrocomplexes with a higher positive charge content in macromolecules provides excellent anti-electrostatic properties during long operation in combination with other important film properties, such as slippery, facilitating mold and mold separation, improved wetting tension, cold bonding adhesion and adhesion to different types of glues etc .;

(2) all disclosed components of functional polymers in coated compositions refer to a class of water-soluble bioengineered polymeric systems, whereby the technology of film production and processing is an ecological chemical technology;

(3) improved coating processing technology allows the use of this method to produce a wide range of monolayer or multilayer bi-oriented polyolefin films and their laminates with various polar thermoplastic and thermoset polymers, (4) the possibility of expanding the range of conventional applications. The disclosed films are also suitable for special applications as a new generation of anti-bacterial and anti-fog films due to the high positive charge of the film surface.

[0037] The acrylic / maleic anti-electrostatic film coated in-line developed in the invention may be antibacterial or antifog or biocidal or degradable or biodegradable or low SIT or combine these features. [0038] The developed acrylic / maleic anti-electrostatic film coated in-line can be a single-layer bi-oriented polypropylene (BOPP) film comprising: one layer of polypropylene or a mixture of polypropylene with a poly (ethylene-co-propylene) copolymer or poly (ethylene) terpolymer -co-propylene-cobutylene) and one thin surface antistatic layer applied in-line.