WO2024048096A1 - Film de revêtement formant barrière contre les gaz - Google Patents

Film de revêtement formant barrière contre les gaz Download PDF

Info

Publication number
WO2024048096A1
WO2024048096A1 PCT/JP2023/026207 JP2023026207W WO2024048096A1 WO 2024048096 A1 WO2024048096 A1 WO 2024048096A1 JP 2023026207 W JP2023026207 W JP 2023026207W WO 2024048096 A1 WO2024048096 A1 WO 2024048096A1
Authority
WO
WIPO (PCT)
Prior art keywords
film
gas barrier
coating layer
less
coating
Prior art date
Application number
PCT/JP2023/026207
Other languages
English (en)
Japanese (ja)
Inventor
徹 今井
健介 種木
敦史 山崎
充裕 柏
Original Assignee
東洋紡株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 東洋紡株式会社 filed Critical 東洋紡株式会社
Publication of WO2024048096A1 publication Critical patent/WO2024048096A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties

Definitions

  • the present invention relates to a gas barrier coated film. More specifically, the present invention relates to a gas barrier coated film that has low environmental impact upon disposal and has both excellent gas barrier performance and adhesive strength sufficient as a packaging material.
  • Monomaterialization means that when various films are laminated to form a packaging material, each film is made into a single material, which has the advantage that the packaging material itself can be chemically recycled.
  • the sealant film constituting the packaging material is generally made of polypropylene or polyethylene, it is also common to use polypropylene or polyethylene as the base film. It is known that polypropylene film can be biaxially stretched during the manufacturing process to provide sufficient strength and heat resistance as a base film, and is widely used. On the other hand, biaxially stretched polyethylene film is technically difficult and has not yet been put into practical use. If a polyethylene film such as linear low density polyethylene film (LLDPE) is used as a sealant film, the surface substrate In the case of polypropylene, it is an olefin-based monomaterial and cannot be chemically recycled as polypropylene or polyethylene in some cases.
  • LLDPE linear low density polyethylene film
  • films in which polyethylene films are laminated with polymeric resin compositions that are generally said to have relatively high oxygen barrier properties such as polyvinyl alcohol, ethylene vinyl alcohol copolymers, polyvinylidene chloride resins, and polyacrylonitrile, have been used.
  • polymeric resin compositions that are generally said to have relatively high oxygen barrier properties, such as polyvinyl alcohol, ethylene vinyl alcohol copolymers, polyvinylidene chloride resins, and polyacrylonitrile
  • gas barrier coated films made using the above-mentioned polymeric resin compositions of polyvinyl alcohol and ethylene vinyl alcohol copolymers are highly dependent on humidity, and therefore, a decrease in gas barrier properties was observed under high humidity conditions.
  • a gas barrier coated film As a method of improving the humidity dependence of vinyl alcohol resin, a gas barrier coated film has been proposed in which a coating layer of vinyl alcohol resin mixed with a silane crosslinking agent is laminated.
  • the vinyl alcohol resin since the vinyl alcohol resin is crosslinked with silanol groups, it has low humidity dependence and exhibits good gas barrier properties (see, for example, Patent Documents 4 and 5).
  • these gas barrier coated films require sufficient heat treatment to crosslink, and if the base material is polyethylene film, the mechanical properties deteriorate and wrinkles due to heat during processing may cause the properties to be insufficient for use as a packaging material. In addition to this, a large amount of thermal energy is required during heat treatment during processing, which is not desirable from the standpoint of environmental impact. Furthermore, the water vapor barrier performance was still insufficient.
  • the inorganic layered particles are often not uniformly dispersed in the coating film, which may result in impaired adhesion to the base film, resulting in a decrease in laminate strength.
  • sufficiently satisfactory performance was not obtained in terms of improving both oxygen barrier properties and water vapor barrier properties.
  • barrier coat layers In order for all of the above-mentioned barrier coat layers to exhibit sufficient barrier performance, it was necessary to laminate them to a thickness of at least 0.5 ⁇ m or more. If the coating layer is thick (a large amount is attached), recycling may become difficult. It was also unfavorable from the viewpoint of monomaterialization using a single material. Furthermore, in processing steps such as printing, there is also the problem of printing defects due to coating irregularities and unevenness.
  • the object of the present invention is to provide a gas barrier coating that is composed of a substantially single type of resin that has a low environmental impact, mainly consisting of polyethylene film, and that has the necessary performance such as gas barrier properties, adhesiveness, and processability required for packaging materials.
  • the goal is to provide film.
  • the present inventors completed the present invention by discovering that by laminating a predetermined coating layer tailored to the required performance on a polyethylene film, it was possible to greatly improve gas barrier performance and provide a film with less environmental impact. I ended up doing it.
  • the present invention consists of the following configuration.
  • a gas barrier coated film characterized by: (a) The base film is a biaxially stretched film containing a polyethylene resin.
  • a gas barrier coated film that has the necessary performances such as gas barrier properties, adhesive properties, and processability required for packaging materials, and has a low environmental impact and is made of a single resin type mainly composed of polyethylene resin. can do.
  • a biaxially stretched polyethylene film is used as the base film of the present invention.
  • the raw materials and mixing ratio of the biaxially oriented polyethylene film are not particularly limited, but may be one selected from polyethylene homopolymers (ethylene homopolymers), ⁇ -olefins containing ethylene as the main component, such as propylene, butene, pentene, hexene, etc. It may be a random copolymer or block copolymer of two or more types, or a mixture of two or more of these polymers.
  • known additives such as antioxidants, antistatic agents, and plasticizers may be added for the purpose of improving physical properties, and for example, petroleum resins and terpene resins may be added.
  • the biaxially oriented polyethylene film used as the base film of the present invention may be a single layer film, or may be a laminated film in which a plurality of resin films including the biaxially oriented polyethylene film are laminated.
  • the type of laminate, the number of layers, the lamination method, etc. are not particularly limited, and can be arbitrarily selected from known methods depending on the purpose.
  • the lower limit of the melt flow rate (MFR) (190°C, 2.16 kgf) of the polyethylene resin used as the raw material for the biaxially stretched polyethylene film used as the base film of the present invention is preferably 0.5 g/10 minutes.
  • the lower limit of MFR is more preferably 0.8 g/10 minutes, still more preferably 1.2 g/10 minutes, particularly preferably 1.5 g/10 minutes.
  • the upper limit of MFR is preferably 15 g/10 minutes.
  • the upper limit of MFR is more preferably 10 g/10 minutes, still more preferably 8 g/10 minutes.
  • the biaxially stretched polyethylene film used as the base film of the present invention is preferably a biaxially stretched film consisting of a longitudinal direction (MD direction) and a transverse direction (TD direction) from the viewpoint of rigidity and heat resistance.
  • MD direction longitudinal direction
  • TD direction transverse direction
  • the stretching method include simultaneous biaxial stretching, sequential biaxial stretching, etc., but sequential biaxial stretching using a tenter method is particularly preferable, and improves flatness, thermal dimensional stability, tensile strength, thickness unevenness, etc. can be considered good.
  • polyethylene resin is heated and melted in a single-screw or twin-screw extruder at a resin temperature of 180 ° C. or higher and 280 ° C. or lower, and then formed into a sheet using a T-die.
  • An unstretched sheet is obtained by extruding onto a chill roll at a temperature of 10° C. or higher and 40° C. or lower.
  • the temperature is 3.0 times or more and 8.0 times or less (preferably 4.1 times or more and 7.0 times or less).
  • heat setting treatment is performed while relaxing 1% to 8% (preferably 3% to 7%) at a temperature of 100°C to 150°C (preferably 110°C to 130°C). It can be performed.
  • the biaxially oriented polyethylene film used as the base film of the present invention preferably contains particles to form protrusions on the film surface in order to impart handling properties (for example, winding properties after lamination).
  • particles to be included in the film include inorganic particles such as silica, kaolinite, talc, calcium carbonate, zeolite, and alumina, and heat-resistant polymer particles such as acrylic, PMMA, nylon, polystyrene, polyester, and benzoguanamine/formalin condensate. It will be done. From the viewpoint of transparency, the content of particles in the film is preferably small, for example, preferably 1 ppm or more and 1000 ppm or less.
  • particles having a refractive index similar to that of the resin used are preferable to select particles having a refractive index similar to that of the resin used.
  • antioxidants ultraviolet absorbers, antistatic agents, pigments, lubricants, nucleating agents, adhesives, antifogging agents, flame retardants, and antiblocking agents.
  • an inorganic or organic filler, etc. may be included.
  • the biaxially oriented polyethylene film used as the base film of the present invention is designed to improve mechanical properties and adhesion with the ink layer and adhesive layer laminated on the gas barrier coating layer, which impairs the purpose of the present invention.
  • Resins other than the polyethylene resins may be contained within the range not limited thereto. Examples include polyethylene resins different from those mentioned above, random copolymers that are copolymers of propylene and ethylene and/or ⁇ -olefins having 4 or more carbon atoms, and various elastomers.
  • the thickness of the biaxially stretched polyethylene film used as the base film of the present invention is arbitrarily set according to each application, but the lower limit is preferably 2 ⁇ m or more, more preferably 3 ⁇ m or more, and still more preferably 4 ⁇ m or more.
  • the upper limit of the thickness is preferably 300 ⁇ m or less, more preferably 250 ⁇ m or less, even more preferably 200 ⁇ m or less, particularly preferably 100 ⁇ m or less.
  • the thickness is thin, handling properties tend to be poor.
  • the thickness is large, not only is there a problem in terms of cost, but also when the film is wound into a roll and stored, poor flatness due to curling tends to occur.
  • the upper limit of the longitudinal heat shrinkage rate of the biaxially stretched polyethylene film used as the base film of the present invention after heat treatment at 90°C for 5 minutes is preferably 8%, more preferably 7%, and still more preferably 6%. be. Further, the upper limit of the heat shrinkage rate in the width direction of the biaxially stretched polyethylene film after heat treatment at 90° C. for 5 minutes is preferably 8%, more preferably 7%, and even more preferably 6%. On the other hand, the lower limit of the heat shrinkage rate in the longitudinal direction and the width direction after heat treatment at 90° C. for 5 minutes is preferably -5%, more preferably -3%. If the heat shrinkage rate is high, wrinkles will occur when the base film is coated with the gas barrier coating layer and wound up into a roll, making it impossible to obtain a film roll with a good appearance.
  • the heat shrinkage rate of the biaxially stretched polyethylene film used as the base film of the present invention 8.0% or less after heat treatment at 90°C for 5 minutes in the longitudinal direction and width direction
  • film formation can be carried out by the sequential biaxial stretching method using the above-mentioned tenter method.
  • Thermal shrinkage rate is caused by relaxation of the stretched polymer chains, so it can be reduced by increasing the relaxation rate after the lateral stretching step.
  • the temperature during stretching to a high temperature, the degree of tension in the molecular chains can be reduced and the thermal shrinkage rate can be reduced.
  • the ratio of heat shrinkage ratio (width direction/longitudinal direction) after heat treatment at 90°C for 5 minutes in the width direction to the longitudinal direction is preferably 1.47 to 1.88 times, more preferably It is 1.49 to 1.80 times, more preferably 1.51 to 1.70 times.
  • the lower limit of the longitudinal tensile strength at break of the biaxially stretched polyethylene film used as the base film of the present invention is preferably 80 MPa, more preferably 90 MPa, and even more preferably 100 MPa. Further, the lower limit of the tensile strength at break in the width direction of the biaxially stretched polyethylene film is preferably 80 MPa, more preferably 90 MPa, and still more preferably 100 MPa. On the other hand, there is no particular upper limit for the tensile strength at break in the longitudinal and width directions, but since it is usually difficult to produce a biaxially oriented polyethylene film with a strength exceeding 250 MPa, it is preferably 250 MPa or less, more preferably 230 MPa or less, and even more preferably It is 210 MPa or less.
  • the base film will not be able to withstand the tension when the base film is coated with a gas barrier coating layer and wound into a roll, and breaks will occur frequently. Industrial production becomes difficult.
  • the above-mentioned polyethylene resin is used as a raw material and the above-mentioned tenter method is applied.
  • An example of this method is to form a film using a sequential biaxial stretching method.
  • the tensile strength at break can be increased by oriented crystallization of the polymer chains by longitudinal and lateral stretching.
  • the tensile strength at break can be increased by increasing the stretching ratio. When increasing the stretching ratio, setting a high stretching temperature improves stretchability and allows a film of good quality to be obtained.
  • the ratio of tensile strength at break in the width direction to the longitudinal direction is preferably 1.47 to 2.50 times, more preferably 1.60 to 2.40 times, More preferably, it is 1.70 to 2.20 times.
  • the upper limit of the haze of the biaxially stretched polyethylene film used as the base film of the present invention is preferably 1.48%, more preferably 1.45%, and still more preferably 1.40%. On the other hand, there is no particular lower limit to haze, but it is usually 0.50%.
  • the biaxially oriented polyethylene film used as the base film of the present invention may be subjected to corona discharge treatment, glow discharge treatment, flame treatment, or surface roughening treatment, as long as the purpose of the present invention is not impaired.
  • Known anchor coating treatment, printing, decoration, etc. may be applied.
  • a resin other than polyolefin, such as polyurethane or polyester, for the anchor coat it is preferable not to perform the anchor coat treatment from the viewpoint of monomaterials.
  • gas barrier coated film In the gas barrier coated film of the present invention, a coating layer having excellent gas barrier properties is laminated on a base film for the purpose of improving gas barrier performance and adhesion.
  • a coating layer having excellent gas barrier properties is laminated on a base film for the purpose of improving gas barrier performance and adhesion.
  • the amount of the coating layer deposited in the present invention is preferably 0.10 to 0.60 (g/m 2 ).
  • gas barrier properties and coat appearance can be improved by keeping the coating amount within the above-mentioned specific range. , can achieve both adhesion and recyclability. This allows the coating layer to be uniformly controlled during coating, resulting in a film with less coating unevenness and defects. Furthermore, since the coating layer is thin, it can contribute to reducing foreign matter during recycling.
  • the lower limit of the amount of adhesion of the coating layer is preferably 0.15 (g/m 2 ), more preferably 0.20 (g/m 2 ), and still more preferably 0.25 (g/m 2 ), and the upper limit is is preferably 0.45 (g/m 2 ), more preferably 0.40 (g/m 2 ), and even more preferably 0.35 (g/m 2 ). If the coating weight exceeds 0.60 (g/m 2 ), the gas barrier properties will improve, but the cohesive force inside the coating layer will be insufficient and the uniformity of the coating layer will also deteriorate, resulting in poor coat appearance. Gas barrier properties and adhesion properties may not be fully developed due to unevenness (increased haze, whitening) and defects.
  • the resin composition used for the coating layer of the gas barrier coated film of the present invention contains a polyvinyl alcohol polymer.
  • Polyvinyl alcohol-based polymers have vinyl alcohol units as their main constituents, and can be expected to significantly improve barrier performance due to high cohesiveness due to hydrogen bond structures.
  • the degree of polymerization and saponification of the polyvinyl alcohol polymer are determined based on the desired gas barrier properties and the viscosity of the aqueous coating solution. Regarding the degree of polymerization, coating is difficult due to the high viscosity of the aqueous solution and the tendency to gel, so a degree of polymerization of 2,600 or less is preferable from the viewpoint of workability of coating.
  • the degree of saponification is preferably 90 to 99.7%, more preferably 93 to 99.7%.
  • various copolymerized or modified polyvinyl alcohol polymers such as polyvinyl alcohol polymers copolymerized with ethylene and polyvinyl alcohol polymers modified with silanol, are also used within the range that does not impair processability or productivity. can.
  • the resin composition used for the coating layer of the gas barrier coated film of the present invention contains an inorganic layered compound.
  • an inorganic layered compound By containing the inorganic layered compound, a labyrinth effect can be expected when gas permeates through the coating layer, and gas barrier properties are improved.
  • the inorganic layered compound include clay minerals (including synthetic products thereof) such as smectite, kaolin, mica, hydrotalcite, and chlorite.
  • scaly silica or the like can be used as an inorganic layered compound. These may be used alone or in combination of two or more.
  • smectite is particularly preferred because it has a high effect of improving water vapor barrier properties.
  • the inorganic layered compound one in which metal ions having redox properties, particularly iron ions, are present is preferable.
  • montmorillonite which is a type of smectite, is preferred from the viewpoint of coating suitability and gas barrier properties.
  • known ones that have been conventionally used in gas barrier agents can be used. Examples include those of the following general formula: (X, Y) 2 ⁇ 3 Z 4 O 10 (OH) 2 ⁇ mH 2 O ⁇ (W ⁇ ) (In the formula, X represents Al, Fe(III), or Cr(III). Y represents Mg, Fe(II), Mn(II), Ni, Zn, or Li. Z represents Si , or Al.
  • W represents K, Na, or Ca.
  • H 2 O represents interlayer water.
  • m and ⁇ represent positive real numbers.)
  • W in the formula is Na are preferred because the inorganic layered compound is easily cleaved between layers to become fine and dispersed in an aqueous medium.
  • the size and shape of the inorganic layered compound are not particularly limited, but the particle diameter (length) is preferably 5 ⁇ m or less, more preferably 4 ⁇ m or less, and still more preferably 3 ⁇ m or less.
  • the particle diameter is larger than 5 ⁇ m, the dispersibility is poor, and as a result, the coatability of the coating layer and the appearance of the coat may deteriorate.
  • the aspect ratio is preferably 50 to 5,000, more preferably 100 to 4,000, and even more preferably 200 to 3,000.
  • the blending ratio of the polyvinyl alcohol copolymer and the inorganic layered compound (polyvinyl alcohol copolymer/inorganic layered compound) of the resin composition used for the coating layer of the gas barrier coated film of the present invention is 75/25 to 35/65. (% by mass), more preferably from 70/30 to 40/60 (% by mass), even more preferably from 65/35 to 45/55 (% by mass). If the blending ratio of the inorganic layered compound is less than 25% by mass, the barrier performance may be insufficient. On the other hand, if the blending ratio of the inorganic layered compound is more than 65% by mass, the dispersibility will be poor and there is a risk of deterioration of coatability and adhesion.
  • the ratio (P1/P2) of (P2) must be within the range of 3.0 to 25.0. It is preferably in the range of 3.5 to 24.0, more preferably in the range of 4.0 to 23.0.
  • the peak at 1040 ⁇ 10 cm ⁇ 1 is a peak derived from the silica molecular structure, and serves as an indicator of the amount of silica bonding derived from the inorganic layered compound in the coating layer.
  • the peak at 3300 ⁇ 10 cm ⁇ 1 is a peak derived from hydroxyl groups, and serves as an indicator of the amount of hydroxyl groups in the coating layer.
  • (P1/P2) represents the ratio of silica bonds to hydroxyl groups, and when this ratio is within the above range, silica particles are arranged in the film without inhibiting the hydrogen bonds of hydroxyl groups, resulting in improved gas barrier performance. maximized.
  • adhesion can also be developed at the same time.
  • (P1/P2) is less than 3.0, the amount of silica bonding in the coating layer is small and a labyrinth effect cannot be obtained, so that it may be difficult to obtain satisfactory gas barrier properties.
  • the arithmetic mean roughness of the coating layer surface of the gas barrier coated film of the present invention at a viewing angle of 2 ⁇ m square using an atomic force microscope is 2.0 nm or more and 8.0 nm or less. This allows the coating layer to maintain uniformity and exhibit stable gas barrier performance, as well as improve adhesiveness and anti-blocking properties due to the formation of surface irregularities mainly derived from the coordination of the inorganic layered compound.
  • the arithmetic mean roughness is preferably 2.5 nm or more, more preferably 3.0 nm or more, even more preferably 3.5 nm or more, and preferably 7.5 nm or less, more preferably 7.0 nm or less, even more preferably It is 6.5 nm or less.
  • the arithmetic mean roughness exceeds 8.0 nm, the surface becomes too rough and the uniformity of the coating layer decreases, causing spots and defects in the coat appearance, which may reduce printability, adhesion, and gas barrier properties. There is. On the other hand, if the arithmetic mean roughness is less than 2.0 nm, the surface will be too flat, and there is a risk that adhesiveness, ink transferability during printing, etc. will be reduced. In addition, the blocking resistance, which will be described later, is also deteriorated, and blocking may occur when the film is wound into a roll.
  • the above-mentioned materials are used to achieve the predetermined coating amount, the mixing ratio of the materials is set to the appropriate range, and the coating method described below is applied. It is necessary to combine this with the dilution conditions of the industrial solution and the drying and heat treatment conditions.
  • the coating layer of the gas barrier coated film of the present invention may contain various crosslinking agents for the purpose of improving the cohesive force and moist heat resistant adhesiveness of the film, as long as it does not impair gas barrier properties or productivity.
  • the crosslinking agent include silicon-based crosslinking agents, oxazoline compounds, carbodiimide compounds, epoxy compounds, and isocyanate compounds.
  • silicon-based crosslinking agents are particularly preferred from the viewpoint of improving water-resistant adhesion to the inorganic thin film layer.
  • an oxazoline compound, a carbodiimide compound, an epoxy compound, etc. may be used in combination. However, if recyclability is important, it is preferable not to include a crosslinking agent.
  • the haze of the gas barrier coated film of the present invention (after lamination of the coating layer) is preferably 20% or less, more preferably 18% or less, still more preferably 16% or less. . If the haze is greater than 20%, in addition to greatly deteriorating transparency, there is a concern that surface irregularities may be affected, which may lead to poor appearance in subsequent printing steps and the like.
  • the lower limit of haze is not particularly limited, but is usually 3% or more, preferably 5% or more. Note that the haze can be adjusted by changing the composition ratio, solvent conditions, film thickness, etc. of the coating layer.
  • the haze was evaluated in accordance with JIS K7136 using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., NDH2000).
  • the method for laminating the coating layer is to disperse the resin composition containing the polyvinyl alcohol copolymer and inorganic layered compound in a solvent to make a coating solution, and apply the coater to the biaxially stretched polyethylene film as the base material.
  • Preferred is a method in which lamination is carried out by coating the film and then drying it.
  • As the solvent an aqueous solvent prepared by mixing water and alcohol is preferable from the viewpoint of dispersibility, environment, and hygiene.
  • the coating method of the resin composition for the coating layer is not particularly limited, and for example, ordinary coating methods such as gravure coating, reverse roll coating, wire bar coating, die coating, etc. can be employed.
  • Pre-drying temperature is preferably 80 to 110°C, more preferably 85 to 105°C, still more preferably 90 to 100°C. If the pre-drying temperature is less than 80°C, there is a risk that the coating layer will be insufficiently dried. Furthermore, if the pre-drying temperature is higher than 110° C., drying will proceed before the coating layer is wetted and spread, which may result in poor appearance.
  • the main drying temperature is preferably 110 to 140°C, more preferably 115 to 135°C, and even more preferably 120 to 130°C. If the main drying temperature is less than 110° C., the film formation of the coating layer will not proceed, resulting in a decrease in cohesive force and adhesiveness, and as a result, there is a possibility that the barrier properties will also be adversely affected. If the temperature exceeds 140° C., too much heat is applied to the film, making it brittle, and there is a risk that wrinkles due to heat shrinkage will increase.
  • the preferred drying time for pre-drying is 3.0 to 10.0 seconds, more preferably 3.5 to 9.5 seconds, even more preferably 4.0 to 9.0 seconds. Further, the preferred drying time for the main drying is 3.0 to 10.0 seconds, more preferably 3.5 to 9.5 seconds, and still more preferably 4.0 to 9.0 seconds. However, care must be taken as the drying conditions vary depending on the heating medium type and the intake and exhaust conditions of the drying oven. In addition to drying, additional heat treatment for 1 to 4 days at as low a temperature as possible, specifically in the temperature range of 40 to 60°C, is also more effective in promoting the formation of the coating layer. be.
  • the gas barrier coated film of the present invention preferably has an oxygen permeability of 50 ml/m 2 ⁇ day ⁇ MPa or less under conditions of 23° C. and 65% RH in order to exhibit good gas barrier properties. Furthermore, by controlling the above-mentioned coating layer components, adhesion amount, etc., it is possible to make it preferably 40 ml/m 2 ⁇ day ⁇ MPa or less, more preferably 30 ml/m 2 ⁇ day ⁇ MPa or less. When the oxygen permeability exceeds 50 ml/m 2 ⁇ day ⁇ MPa, it becomes difficult to support applications requiring high gas barrier properties.
  • the oxygen permeability is less than 1 ml/m 2 ⁇ day ⁇ MPa, the barrier performance is excellent, but it becomes difficult for the residual solvent to permeate to the outside of the bag, and there is a risk that the amount transferred to the contents will increase relatively. I don't like it because it is.
  • a preferable lower limit of the oxygen permeability is 1 ml/m 2 ⁇ day ⁇ MPa or more.
  • the gas barrier coated film of the present invention preferably has a water vapor permeability of 4.9 g/m 2 ⁇ day or less under conditions of 40° C. and 90% RH in order to exhibit good gas barrier properties. Furthermore, by controlling the above-mentioned coating layer components and adhesion amount, the coating layer can be preferably 4.7 g/m 2 ⁇ day or less, more preferably 4.5 g/m 2 ⁇ day or less. When the water vapor permeability exceeds 4.9 g/m 2 ⁇ day, it becomes difficult to support applications requiring high gas barrier properties.
  • water vapor permeability is less than 0.1 g/m 2 ⁇ day, the barrier performance is excellent, but it becomes difficult for the residual solvent to permeate to the outside of the bag, and there is a risk that the amount transferred to the contents will increase relatively. I don't like it because it is.
  • a preferable lower limit of water vapor permeability is 0.1 g/m 2 ⁇ day or more.
  • the gas barrier coated film of the present invention When the gas barrier coated film of the present invention is used as a packaging material, it is preferable to form a laminate in which a heat sealing resin layer (sealant layer) called a sealant is laminated on at least one side of the gas barrier coated film.
  • the sealant layer is usually laminated on the coating layer of the gas barrier coat film, but it can also be laminated on the outside of the base film layer (the surface opposite to the surface on which the coating layer is formed).
  • the sealant layer is usually formed by extrusion lamination or dry lamination.
  • the thermoplastic polymer forming the sealant layer may be one that can sufficiently exhibit heat-sealing properties, but polyethylene resins such as HDPE, LDPE, and LLDPE, polypropylene resins, and ethylene-vinyl acetate copolymers may be used. , ethylene- ⁇ -olefin random copolymer, ionomer resin, etc. can be used, but in the present invention, polyethylene resin is preferable in order to make it into a monomaterial that can be easily recycled. LLDPE is particularly preferred from the viewpoints of durability, seal strength, and cost.
  • the thickness of the sealant layer is preferably 20 to 100 ⁇ m, more preferably 30 to 90 ⁇ m, and still more preferably 40 to 80 ⁇ m.
  • the thickness is less than 20 ⁇ m, sufficient sealing strength may not be obtained, and the seal may not have a firm feel and may be difficult to handle. On the other hand, if the thickness exceeds 100 ⁇ m, the bag will have a stiff feel and will not be easy to handle as a bag, and may also be expensive.
  • a general-purpose laminating adhesive can be used as the adhesive layer used when laminating the sealant film on the gas barrier coated film by the dry lamination method.
  • a general-purpose laminating adhesive can be used.
  • Solvent-based, water-based, or hot-melt type adhesives whose main component is a wax-based adhesive, a wax-based adhesive, a casein-based adhesive, or the like can be used.
  • polyurethane-based or polyester-based materials are preferred in consideration of heat resistance and flexibility that can follow dimensional changes of each base material.
  • laminating methods for the adhesive layer include direct gravure coating, reverse gravure coating, kiss coating, die coating, roll coating, dip coating, knife coating, spray coating, fontaine coating, and others.
  • the coating amount after drying is preferably 1 to 8 g/m 2 in order to develop sufficient adhesion. More preferably 2 to 7 g/m 2 , still more preferably 3 to 6 g/m 2 . If the coating amount is less than 1 g/m 2 , it becomes difficult to bond the entire surface, and the adhesive strength decreases. Moreover, when it exceeds 8 g/m 2 , it takes time to completely cure the film, unreacted substances tend to remain, and adhesive strength decreases.
  • the gas barrier coated film of the present invention when used as a packaging material, at least one printed layer or other plastic base material and/or paper base material is provided between the base film layer and the sealant layer or on the outside thereof. It may be laminated.
  • aqueous and solvent-based resin-containing printing inks can be preferably used.
  • resins used in the printing ink include acrylic resins, urethane resins, polyester resins, vinyl chloride resins, vinyl acetate copolymer resins, and mixtures thereof.
  • the printing ink contains known antistatic agents, light blocking agents, ultraviolet absorbers, plasticizers, lubricants, fillers, colorants, stabilizers, lubricants, antifoaming agents, crosslinking agents, anti-blocking agents, antioxidants, etc. It may also contain additives.
  • the printing method for providing the printed layer is not particularly limited, and known printing methods such as offset printing, gravure printing, and screen printing can be used.
  • known drying methods such as hot air drying, hot roll drying, and infrared drying can be used.
  • the laminate of the gas barrier coated film and the sealant layer (sealant film) of the present invention preferably has a lamination strength of 1.0 N/15 mm or more, more preferably 1.0 N/15 mm or more under 23°C x 65% RH conditions. .2N/15mm or more, more preferably 1.5N/15mm or more. If the laminate strength is less than 1.0 N/15 mm, peeling may occur due to bending load or heat during sealing, and there is a risk that barrier properties may deteriorate or contents may leak. Furthermore, there is also a possibility that the ease of cutting by hand may deteriorate.
  • the upper limit is not particularly limited, but is usually 3.0 N/15 mm or less, preferably 2.5 N/15 mm or less.
  • Heat shrinkage rate Measured according to JIS Z 1712 by the following method. The film was cut to a width of 20 mm and a length of 200 mm in the longitudinal direction and the width direction, respectively, and was hung in a hot air oven at 90° C. and heated for 5 minutes. The length after heating was measured, and the heat shrinkage rate was calculated as the ratio of the shrunk length to the original length.
  • Arithmetic mean roughness of the surface of the coating layer The surface roughness of the film on which the gas barrier coating layer is laminated is measured using a scanning probe microscope (SPM) ("SPM9700" manufactured by Shimadzu Corporation) (cantilever: Olympus Observation mode: phase mode) was used. Specifically, SPM images were obtained at a viewing angle of 2 ⁇ m square on the film surface. In the obtained image, the inclination correction in the X direction, Y direction, and Z direction was performed using the inclination correction function of the software attached to the SPM, and then the value of the arithmetic mean roughness was calculated.
  • SPM scanning probe microscope
  • Arithmetic mean roughness is calculated by extracting only a reference length in the direction of the average line from a roughness curve obtained by removing surface waviness components longer than a predetermined wavelength from the cross-sectional curve using a high-pass filter, and calculating the roughness by extracting only a reference length in the direction of the average line of the sampled part.
  • the value obtained by the following formula is taken as a two-dimensional expanded value. (In the formula, L: standard length)
  • Oxygen permeability In each example and comparative example, a film in which a gas barrier coating layer was laminated on a base film was used as a sample, and an oxygen permeability measuring device (manufactured by MOCON, Inc. Oxygen permeability was measured in an atmosphere with a temperature of 23° C. and a humidity of 65% RH using OX-TRAN (registered trademark) 1/50”). The oxygen permeability was measured in the direction in which oxygen permeated from the base film side to the coating layer side.
  • OX-TRAN registered trademark
  • Lamination strength A test piece was prepared by cutting out a laminate of a sealant film and a film with a gas barrier coating layer laminated by the method described below into a test piece with a width of 15 mm and a length of 200 mm, and the test piece was prepared at a temperature of 23°C and a relative humidity of 65% Below, the laminate strength (normal state) was measured using a Tensilon universal material testing machine ("Tensilon UMT-II-500 model" manufactured by Toyo Baldwin Co., Ltd.). The laminate strength was measured by peeling the sealant film and the film laminated with the gas barrier coating layer obtained in Examples and Comparative Examples at a peeling angle of 90 degrees at a tensile speed of 200 mm/min. It was measured.
  • Coating solutions 1 to 4 prepared below were coated on the corona-treated surface of the prepared biaxially stretched polyethylene film by a gravure roll coating method. Main drying was performed for ⁇ 4 seconds to obtain a coating layer. The amount of adhesion after drying was 0.40 g/m 2 (Dry). Thereafter, a post-heating treatment was performed at 40° C. for 2 days.
  • gas barrier coated films were produced in the same manner as in Example 1 using the coating liquid, coating layer composition, coating amount, and drying conditions shown in Table 2.
  • Inorganic layered compound dispersion (B) 5 parts by mass of montmorillonite (trade name: Kunipia F, manufactured by Kunimine Kogyo Co., Ltd.), which is an inorganic layered compound, was added to 95 parts by mass of purified water with stirring, and sufficiently dispersed using a homogenizer at 1500 rpm. Thereafter, the mixture was kept at 23° C. for 1 day to obtain an inorganic layered compound dispersion having a solid content of 5%.
  • montmorillonite trade name: Kunipia F, manufactured by Kunimine Kogyo Co., Ltd.
  • a coating liquid (resin composition for coating layer) was prepared by mixing each material in the following blending ratio.
  • the unit is "mass %”.
  • Comparative Examples 1 and 2 the drying conditions after coating with the coating solution were weak, so that solvent volatilization of the coating layer was insufficient, and the appearance of the surface of the coating layer was also poor. Comparative Example 3 had poor oxygen barrier properties, transparency, and surface smoothness because the drying conditions after coating with the coating solution were too strong.
  • Example 2 The resulting film was coated with the coating liquid in the same manner as in Example 1, dried under the same conditions as in Example 1 where the solvent was sufficiently dried, and then wound up into a roll. A coated film worthy of evaluation could not be obtained because it did not cut and broke. Since no coated film was obtained in Comparative Example 5, the column for the amount of coating layer adhered in Table 2 listed the target amount of adhered layer.
  • Comparative Examples 6 to 8 In coating the coating layer, a laminate of a gas barrier coated film and a sealant film was prepared in the same manner as in Example 1, except that the above coating solutions 5, 6, and 7 were used as shown in Table 2. Created. The gas barrier coated films of Comparative Examples 6 to 8 had poor oxygen gas barrier properties.
  • the gas barrier coated film of the present invention can form a heat-sealable laminate with low environmental impact that is composed of almost a single type of resin, mainly polyethylene resin, and also has the gas barrier properties and adhesive properties required for packaging materials. Therefore, it can be widely used as packaging materials for foods and industrial products.

Landscapes

  • Laminated Bodies (AREA)

Abstract

La présente invention concerne un film de revêtement formant barrière contre les gaz qui est principalement composé d'un film de polyéthylène et est généralement conçu à partir d'un seul type de résine avec un faible impact environnemental et qui a les propriétés nécessaires requises pour des matériaux d'emballage, tels que des propriétés de barrière contre les gaz, l'adhésivité et l'aptitude au traitement.　Le film de revêtement formant barrière aux gaz est un film multicouche qui est obtenu en fournissant une couche de revêtement qui comprend un copolymère d'alcool polyvinylique et un composé stratifié inorganique sur au moins une surface d'un film de matériau de base ; et le film multicouche satisfait aux exigences décrites ci-dessous. (a) : Le film de matériau de base est un film étiré biaxialement qui contient une résine de polyéthylène. (b) : Par rapport au spectre d'absorption infrarouge à réflexion totale du film multicouche, le rapport (P1/P2) de l'intensité de pic (P1) ayant une absorption maximale dans la région de 1 040 ± 10 cm-1 à l'intensité de pic (P2) ayant une absorption maximale dans la région de 3 300 ± 10 cm-1 est dans la plage de 3,0 à 25,0. (c) : La rugosité moyenne arithmétique dans une zone carrée de 2 µm de la surface de la couche de revêtement est de 2,0 nm à 8,0 nm.
PCT/JP2023/026207 2022-09-02 2023-07-18 Film de revêtement formant barrière contre les gaz WO2024048096A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022140348 2022-09-02
JP2022-140348 2022-09-02

Publications (1)

Publication Number Publication Date
WO2024048096A1 true WO2024048096A1 (fr) 2024-03-07

Family

ID=90099463

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/026207 WO2024048096A1 (fr) 2022-09-02 2023-07-18 Film de revêtement formant barrière contre les gaz

Country Status (1)

Country Link
WO (1) WO2024048096A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11151786A (ja) * 1997-11-20 1999-06-08 Toray Ind Inc ガスバリアフィルム及び包装材料
JP2001009983A (ja) * 1999-06-30 2001-01-16 Toray Ind Inc ガスバリアフィルム
JP2003268183A (ja) * 2002-03-18 2003-09-25 Kuraray Co Ltd 樹脂組成物および用途
JP2005225140A (ja) * 2004-02-13 2005-08-25 Tokuyama Corp ガスバリア性フィルム
WO2022030361A1 (fr) * 2020-08-06 2022-02-10 東洋紡株式会社 Film stratifié et matériau d'emballage

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11151786A (ja) * 1997-11-20 1999-06-08 Toray Ind Inc ガスバリアフィルム及び包装材料
JP2001009983A (ja) * 1999-06-30 2001-01-16 Toray Ind Inc ガスバリアフィルム
JP2003268183A (ja) * 2002-03-18 2003-09-25 Kuraray Co Ltd 樹脂組成物および用途
JP2005225140A (ja) * 2004-02-13 2005-08-25 Tokuyama Corp ガスバリア性フィルム
WO2022030361A1 (fr) * 2020-08-06 2022-02-10 東洋紡株式会社 Film stratifié et matériau d'emballage

Similar Documents

Publication Publication Date Title
CN108463347A (zh) 具有良好密封性能的双取向的空化线性低密度膜
KR20140133841A (ko) 폴리비닐알코올계 증착 필름
JP3892246B2 (ja) ガスバリア性フィルムの製造方法
JP2023171764A (ja) 積層フィルム
WO2010016403A1 (fr) Pellicule de protection de surface
JP4529100B2 (ja) 表面保護フィルム
KR20040067917A (ko) 산소차단성이 개선된 폴리(ｍ-크실렌아디프아미드) 함유외층을 갖는 폴리에스테르 필름, 그 제조방법 및 용도
WO2022030361A1 (fr) Film stratifié et matériau d'emballage
JP2001121659A (ja) ガスバリア性フィルム
WO2024048096A1 (fr) Film de revêtement formant barrière contre les gaz
WO2023127594A1 (fr) Matériau d'emballage
WO2024048097A1 (fr) Film de polyéthylène pour film de revêtement formant une barrière aux gaz
JP7238938B1 (ja) 積層フィルム及び包装材料
WO2022224647A1 (fr) Film stratifié et matériau d'emballage
JP2019155845A (ja) ラミネート積層体
WO2022131266A1 (fr) Film stratifié et matériau d'emballage
KR20240073888A (ko) 적층 필름 및 포장 재료
WO2023037917A1 (fr) Corps en couches stratifié
WO2024058167A1 (fr) Matériau d'emballage
WO2022153965A1 (fr) Corps d'emballage imprimé au laser
WO2022196397A1 (fr) Corps d'affichage stratifié imprimé au laser
JP2001009979A (ja) 積層フィルム
JP2004323616A (ja) ポリエステルフィルム
JP2004243562A (ja) ２軸延伸積層ｅｖｏｈフィルム

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23859866

Country of ref document: EP

Kind code of ref document: A1