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
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • 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
  • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (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
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • 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
  • B32B27/36—Layered products comprising a layer of synthetic resin comprising polyesters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/40—Applications of laminates for particular packaging purposes
• • 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
  • B32B2250/00—Layers arrangement
  • B32B2250/24—All layers being polymeric
• • 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
  • B32B2255/00—Coating on the layer surface
  • B32B2255/10—Coating on the layer surface on synthetic resin layer or on natural or synthetic rubber layer
• • 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
  • B32B2255/00—Coating on the layer surface
  • B32B2255/20—Inorganic coating
• • 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
  • B32B2255/00—Coating on the layer surface
  • B32B2255/20—Inorganic coating
  • B32B2255/205—Metallic coating
• • 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
  • B32B2255/00—Coating on the layer surface
  • B32B2255/26—Polymeric coating
• • 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
  • B32B2255/00—Coating on the layer surface
  • B32B2255/28—Multiple coating on one surface
• • 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
  • B32B2272/00—Resin or rubber layer comprising scrap, waste or recycling material
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
  • B32B2307/306—Resistant to heat
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
  • B32B2307/308—Heat stability
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
  • B32B2307/31—Heat sealable
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/514—Oriented
  • B32B2307/518—Oriented bi-axially
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
  • B32B2307/7244—Oxygen barrier
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
  • B32B2307/7246—Water vapor barrier
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/732—Dimensional properties
  • B32B2307/734—Dimensional stability
  • B32B2307/736—Shrinkable
• • 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
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/732—Dimensional properties
  • B32B2307/737—Dimensions, e.g. volume or area
  • B32B2307/7375—Linear, e.g. length, distance or width
  • B32B2307/7376—Thickness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
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  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/748—Releasability
• • 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
  • B32B2439/00—Containers; Receptacles
• • 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
  • B32B2439/00—Containers; Receptacles
  • B32B2439/02—Open containers
  • B32B2439/06—Bags, sacks, sachets
• • 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
  • B32B2439/00—Containers; Receptacles
  • B32B2439/70—Food packaging
• • 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
  • B32B2439/00—Containers; Receptacles
  • B32B2439/80—Medical packaging
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/80—Packaging reuse or recycling, e.g. of multilayer packaging

Definitions

• the present invention relates to a laminated film used in the packaging field of foods, pharmaceuticals, industrial products, etc. More specifically, it is a laminated laminate formed by laminating a sealant layer on a laminated film having an inorganic thin film layer and a protective layer in this order on a base film layer using a polyester resin recycled from a PET bottle.
• the present invention relates to a laminated film having excellent barrier properties and adhesiveness, and having excellent recyclability, capable of easily separating the film from the laminated laminate.
• the performance required for the above-mentioned environmentally friendly packaging materials is that they are made of recycled materials, have gas barrier performance that can block various gases and extend the expiration date, and do not use materials with a low environmental load (for example, do not use harmful organic solvents). And the amount of material used is small).
• Polyester resin recycled from PET bottles is known as a typical recycled material, and polyester resin derived from PET bottles with a low oligomer content is used for bodyband labels that have less trouble due to static electricity without impairing productivity and quality.
• a technique for making a polyester film is known (see, for example, Patent Document 1). Demand for such film applications is expected to grow due to heightened environmental regulations in the future.
• a metal thin film made of aluminum or the like and an inorganic oxide such as silicon oxide or aluminum oxide are formed on the surface of a base film made of plastic.
• a gas barrier laminate having a thin film formed is generally used.
• those in which a thin film (inorganic thin film layer) of an inorganic oxide such as silicon oxide, aluminum oxide, or a mixture thereof is formed do not need to use an aluminum foil, and are transparent and the contents can be confirmed. Therefore, it is widely used.
• a water-soluble polymer, an inorganic layered compound, and a metal alkoxide or a hydrolyzate thereof are coated on an inorganic thin film, and a composite of the inorganic substance containing the inorganic layered compound and the water-soluble polymer on the inorganic thin film by the sol-gel method.
• examples thereof include a method of forming the above, and a laminate in which a metalxylylene group-containing polyurethane is coated on an inorganic thin film (see, for example, Patent Document 4).
• Patent Document 2 the gas barrier property and adhesiveness after harsh wet heat treatment were not examined.
• Patent Documents 3 and 4 the recyclability of the laminated laminate after use has not been examined.
• Patent Document 5 the barrier property and the adhesive property after the wet heat treatment have not been studied.
• the present invention has been made against the background of the problems of the prior art. That is, a laminate laminate formed by laminating a sealant layer on an environment-friendly laminated film having an inorganic thin film layer and a protective layer in this order on a base film layer using a polyester resin recycled from a PET bottle. It is an object of the present invention to provide a laminated laminate capable of easily separating a laminated film which is a body and has excellent barrier properties and adhesiveness even after harsh wet heat treatment and also has excellent recyclability after use and disposal.
• the present inventors used a polyester resin derived from a PET bottle, which has a low environmental load, as a base material, and made a structure having a specific barrier protective layer having excellent flexibility and adhesiveness to an inorganic thin film layer before treatment. It has been found that the gas barrier performance of the above can be improved and the barrier property and adhesiveness can be maintained even after a harsh wet heat treatment. Furthermore, they have found that the laminated film can be easily peeled off from the laminated laminate by utilizing the property that the protective layer dissolves when immersed in a specific solvent, and completed the present invention.
• the present invention has the following configuration.
• a laminated laminate having an inorganic thin film layer on at least one side of a base film and a sealant layer laminated on one side of a laminated film having a protective layer on the inorganic thin film layer. Is a laminated laminate characterized in that the following (a) to (d) are satisfied.
• the base film contains 10% by weight or more of a polyester resin recycled from a PET bottle.
• the protective layer of the laminated film contains a urethane resin, and the surface free energy of the surface of the protective layer is 45 to 60 mN / m.
• the laminate strength of the laminated laminate is 1.5 N / 15 mm or more, and the laminate strength after being immersed in 1-methoxy-2-propanol for 40 ° C. ⁇ 72 hours is 1.0 N / 15 mm or less.
• the laminate strength of the laminate laminate after the 90 ° C. ⁇ 30 minute boil sterilization treatment is 1.5 N / 15 mm or more.
• the coating layer has a coating layer between the base film layer and the inorganic thin film layer, and the coating layer contains a resin having an oxazoline group or a carbodiimide group as a constituent component in either (1) or (2).
• the present invention it is possible to provide a laminated laminate having excellent barrier properties and adhesiveness even after a harsh wet heat treatment while using a recycled material, and the laminated film can be easily peeled off from the laminated laminate. It has become possible to provide a laminated laminate in which a film having excellent properties can be easily separated.
• the base film is a mixed resin of recycled polyester resin and virgin raw material, that is, non-recycled resin, and the ultimate viscosity of the resin constituting the film is the limit of the mixed resin constituting these films. It means that it is a value obtained by measuring the viscosity.
• the lower limit of the ultimate viscosity of the resin constituting the film obtained by measuring the base film is preferably 0.58 dl / g, more preferably 0.60 dl / g. If it is less than 0.58 dl / g, most of the recycled resins made of PET bottles have an ultimate viscosity of more than 0.68 dl / g, and if the viscosity is lowered when producing a film using it, the thickness unevenness becomes poor. It is not preferable because there is. In addition, the film may be colored, which is not preferable.
• the upper limit is preferably 0.70 dl / g, more preferably 0.68 dl / g. If it exceeds 0.70 dl / g, it becomes difficult to discharge the resin from the extruder and the productivity may decrease, which is not preferable.
• the lower limit of the thickness of the base film is preferably 8 ⁇ m, more preferably 10 ⁇ m, and even more preferably 12 ⁇ m. If it is less than 8 ⁇ m, the strength of the film may be insufficient, which is not preferable.
• the upper limit is preferably 200 ⁇ m, more preferably 50 ⁇ m, and even more preferably 30 ⁇ m. If it exceeds 200 ⁇ m, it may become too thick and difficult to process. Further, increasing the thickness of the film is not preferable in terms of environmental load, and it is preferable to reduce the volume as much as possible.
• the lower limit of the refractive index in the thickness direction of the base film is preferably 1.4930, more preferably 1.4940. If it is less than 1.4930, the orientation may not be sufficient and the laminate strength may not be obtained.
• the upper limit is preferably 1.4995, more preferably 1.4980. If it exceeds 1.4995, the orientation of the surface may be lost and the mechanical properties may be insufficient, which is not preferable.
• the lower limit of the heat shrinkage rate of the base film by treatment at 150 ° C. for 30 minutes in the vertical direction (sometimes referred to as MD) and the horizontal direction (sometimes referred to as TD) is preferably 0.1%, which is more preferable. Is 0.3%. If it is less than 0.1%, the effect of improvement is saturated and it may become mechanically brittle, which is not preferable.
• the upper limit is preferably 3.0%, more preferably 2.5%. If it exceeds 3.0%, pitch deviation may occur due to dimensional changes during processing such as printing, which is not preferable. Further, if it exceeds 3.0%, shrinkage in the width direction may occur due to a dimensional change during processing such as printing, which is not preferable.
• a recycled polyester resin made of a PET bottle containing an isophthalic acid component As a raw material for the base film, it is preferable to use a recycled polyester resin made of a PET bottle containing an isophthalic acid component as an acid component. Crystallinity is controlled in the polyester used for PET bottles in order to improve the appearance of the bottle, and as a result, polyester containing 10 mol% or less of an isophthalic acid component may be used. .. Since the crystal structure of polyester is disrupted by containing isophthalic acid, it contributes to the flexibility of the base material, and by controlling this, it is possible to make a surface on which an inorganic thin film can be easily laminated.
• the lower limit of the amount of the terephthalic acid component in the total dicarboxylic acid component constituting the polyester resin contained in the base film is preferably 95.0 mol%, more preferably 96.0 mol%, and further preferably 96.5 mol%. Yes, especially preferably 97.0 mol%. If it is less than 95.0 mol%, the crystallinity is lowered, so that the heat shrinkage rate may be high, which is not very preferable.
• the upper limit of the amount of the terephthalic acid component of the polyester resin contained in the film is preferably 99.5 mol%, more preferably 99.0 mol%. Many recycled polyester resins made of PET bottles have a dicarboxylic acid component other than terephthalic acid represented by isophthalic acid. Therefore, if the terephthalic acid component constituting the polyester resin in the film exceeds 99.5 mol%, it is recycled. As a result, it becomes difficult to produce a polyester film having a high proportion of resin, which is not very preferable.
• the amount of the isophthalic acid component in the total dicarboxylic acid components constituting the polyester resin contained in the base film in order to impart flexibility for developing the barrier performance.
• the lower limit is preferably 0.5 mol%, more preferably 0.7 mol%, still more preferably 0.9 mol%, and particularly preferably 1.0 mol%. Since some recycled polyester resins made of PET bottles contain a large amount of isophthalic acid components, the fact that the isophthalic acid component constituting the polyester resin in the film is less than 0.5 mol% means that the ratio of the recycled resin is high in the polyester film. As a result, the production becomes difficult, which is not very preferable.
• the upper limit of the amount of the isophthalic acid component in the total dicarboxylic acid components constituting the polyester resin contained in the film is preferably 5.0 mol%, more preferably 4.0 mol%, and further preferably 3.5 mol%. Yes, especially preferably 3.0 mol%. If it exceeds 5.0 mol%, the crystallinity decreases, so that the heat shrinkage rate may increase, which is not very preferable. Further, if the base material becomes too soft, the inorganic thin film cannot follow the change and the barrier performance may deteriorate.
• the surface becomes a surface on which the inorganic thin film layer is easily deposited due to the softening effect of the surface of the base material, and as a result, good barrier properties can be exhibited.
• the upper limit of the ultimate viscosity of the recycled resin made of PET bottles is preferably 0.90 dl / g, more preferably 0.80 dl / g, still more preferably 0.77 dl / g, and particularly preferably 0.75 dl / g. .. If it exceeds 0.9 dl / g, it may be difficult to discharge the resin from the extruder and the productivity may decrease, which is not very preferable.
• the lower limit of the content of the polyester resin recycled from the PET bottle with respect to the film is 10% by weight, preferably 50% by weight, more preferably 65% by weight, and further preferably 75% by weight. If it is less than 10% by weight, the content of the recycled resin is poor and it is not very preferable in terms of contributing to environmental protection. In addition, the amount of the isophthalic acid component is reduced, and there is a possibility that the flexibility superior to the lamination of the inorganic thin film layer cannot be exhibited.
• the upper limit of the content of the polyester resin recycled from the PET bottle is not particularly limited, but is preferably 95% by weight, more preferably 90% by weight, and further preferably 85% by weight.
• a polyester resin recycled from a PET bottle can also be used as a master batch (high-concentration-containing resin) used when a lubricant such as inorganic particles or an additive is added to improve the function of the film.
• lubricant type in addition to inorganic lubricants such as silica, calcium carbonate and alumina, organic lubricants are preferable, and silica and calcium carbonate are more preferable. With these, transparency and slipperiness can be exhibited.
• the average particle size of the lubricant particles is preferably in the range of 0.05 to 3.0 ⁇ m as measured by a Coulter counter.
• the lower limit of the lubricant content in the base film is preferably 0.01% by weight, more preferably 0.015% by weight, and even more preferably 0.02% by weight. If it is less than 0.01% by weight, the slipperiness may decrease.
• the upper limit is preferably 1% by weight, more preferably 0.2% by weight, and even more preferably 0.1% by weight. If it exceeds 1% by weight, the transparency may decrease, which is not very preferable.
• the method for producing the base film used for the laminated film of the present invention is not particularly limited, but for example, the following production method is recommended. It is important to set the temperature for melting and extruding the resin in the extruder.
• the basic idea is that (1) the polyester resin used for PET bottles contains an isophthalic acid component, so while suppressing deterioration by extruding at the lowest possible temperature, (2) extreme viscosity and fine high crystals. In order to sufficiently and uniformly melt the sex portion, it is necessary to have a portion that melts at a high temperature or high pressure. The content of the isophthalic acid component lowers the stereoregularity of the polyester, leading to a lower melting point.
• the melt viscosity is significantly lowered or deteriorated due to heat, the mechanical strength is lowered, and the deteriorated foreign matter is increased. Further, simply lowering the extrusion temperature does not allow sufficient melt-kneading, which may cause problems such as increased thickness unevenness and foreign matter such as fish eyes.
• the recommended manufacturing methods include, for example, using two extruders in tandem, increasing the pressure in the filter section, and using a screw with strong shearing force as part of the screw configuration. Can be mentioned.
• the lower limit of the set temperature of the resin melting part in the extruder (excluding the maximum set temperature of the compression part of the screw in the extruder) is preferably 270 ° C, and the upper limit is preferably 290 ° C. Extrusion is difficult below 270 ° C, and deterioration of the resin may occur above 290 ° C, which is not very preferable.
• the lower limit of the maximum set temperature of the compression part of the screw in the extruder is preferably 295 ° C.
• Polyester resins used in PET bottles often have crystals with a high melting point (260 ° C to 290 ° C) from the viewpoint of transparency.
• additives, crystallization nucleating agents, etc. are added, and there are variations in the fine melting behavior in the resin material. If the temperature is lower than 295 ° C, it becomes difficult to sufficiently melt them, which is not very preferable.
• the upper limit of the maximum set temperature of the compression part of the screw in the extruder is preferably 310 ° C. If the temperature exceeds 310 ° C, the resin may deteriorate, which is not very preferable.
• the lower limit of the time for the resin to pass through the region of the highest set temperature of the compression part of the screw in the extruder is preferably 10 seconds, more preferably 15 seconds. If it is less than 10 seconds, the polyester resin used for the PET bottle cannot be sufficiently melted, which is not very preferable.
• the upper limit is preferably 60 seconds, more preferably 50 seconds. If it exceeds 60 seconds, the resin tends to deteriorate, which is not very preferable.
• the resin melted in this way is extruded into a sheet on a cooling roll and then biaxially stretched.
• a simultaneous biaxial stretching method may be used, but a sequential biaxial stretching method is particularly preferable. These make it easy to meet the productivity and the quality required for the present invention.
• the method of stretching the film is not particularly limited, but the following points are important.
• the magnification and temperature of longitudinal (MD) stretching and transverse (TD) stretching are important. If the MD stretching ratio and temperature are not appropriate, the stretching force may not be applied uniformly, the orientation of the molecules may be insufficient, the thickness unevenness may increase, and the mechanical properties may be insufficient.
• the film may be broken or an extreme increase in thickness unevenness may occur in the next TD stretching step.
• the stretching may not be uniform, the vertical and horizontal orientation balance may be poor, and the mechanical properties may be insufficient.
• the process proceeds to the next heat fixing step in a state where the thickness unevenness is large or the molecular chain orientation is insufficient, it cannot be uniformly relaxed, and the thickness unevenness is further increased and the mechanical properties are insufficient.
• a roll stretching method and an IR heating method are preferable.
• the lower limit of the MD stretching temperature is preferably 100 ° C, more preferably 110 ° C, and even more preferably 120 ° C. If the temperature is lower than 100 ° C., even if a polyester resin having an ultimate viscosity of 0.58 dl / g or more is stretched and molecularly oriented in the longitudinal direction, the film may be broken or an extreme thickness defect may occur in the next transverse stretching step. It is not preferable because it does.
• the upper limit is preferably 140 ° C, more preferably 135 ° C, and even more preferably 130 ° C. If the temperature exceeds 140 ° C., the orientation of the molecular chain becomes insufficient and the mechanical properties may become insufficient, which is not very preferable.
• the lower limit of the MD draw ratio is preferably 2.5 times, more preferably 3.5 times, and even more preferably 4 times. If it is less than 2.5 times, even if a polyester resin having an ultimate viscosity of 0.58 dl / g or more is stretched and molecularly oriented in the longitudinal direction, the film may be broken or an extreme thickness defect may occur in the next transverse stretching step. It is not so preferable.
• the upper limit is preferably 5 times, more preferably 4.8 times, and even more preferably 4.5 times. If it exceeds 5 times, the effect of improving mechanical strength and thickness unevenness may be saturated, which is not very significant.
• the MD stretching method may be the above-mentioned one-step stretching, but it is more preferable to divide the stretching into two or more steps. By dividing into two or more stages, it is possible to satisfactorily stretch a polyester resin made of a recycled resin containing isophthalic acid, which has a high ultimate viscosity, and has good thickness unevenness, laminate strength, mechanical properties, and the like.
• the lower limit of the MD stretching temperature of the first stage is preferably 110 ° C, more preferably 115 ° C. If the temperature is lower than 110 ° C., heat will be insufficient, sufficient longitudinal stretching will not be possible, and flatness will be poor, which is not preferable.
• the upper limit of the MD stretching temperature of the first stage is preferably 125 ° C., more preferably 120 ° C. If the temperature exceeds 125 ° C, the orientation of the molecular chains becomes insufficient and the mechanical properties may deteriorate, which is not very preferable.
• the lower limit of the preferred first-stage MD stretching ratio is 1.1 times, more preferably 1.3 times. If it is 1.1 times or more, the polyester resin having an ultimate viscosity of 0.58 dl / g or more can be sufficiently longitudinally stretched to increase the productivity by performing the weak stretching in the first stage.
• the upper limit of the MD stretching ratio of the first stage is preferably 2 times, more preferably 1.6 times. If it exceeds 2 times, the orientation of the molecular chains in the vertical direction becomes too high, which may make it difficult to stretch the second and subsequent stages and may result in a film having poor thickness unevenness, which is not very preferable.
• the lower limit of the MD stretching temperature of the second stage (or the final stage) is preferably 110 ° C, more preferably 115 ° C.
• the upper limit is preferably 130 ° C, more preferably 125 ° C. If the temperature exceeds 130 ° C., crystallization is promoted, lateral stretching may become difficult, and thickness unevenness may increase, which is not very preferable.
• the lower limit of the MD stretching ratio of the second stage (or the final stage) is preferably 2.1 times, more preferably 2.5 times. If it is less than 2.1 times, even if a polyester resin having an ultimate viscosity of 0.58 dl / g or more is stretched and molecularly oriented in the longitudinal direction, the film may be broken or an extreme thickness defect may occur in the next transverse stretching step. It is not so preferable.
• the upper limit is preferably 3.5 times, more preferably 3.1 times. If it exceeds 3.5 times, the vertical orientation becomes too high, so that the second and subsequent stages cannot be stretched, or the film may have a large thickness unevenness, which is not very preferable.
• the lower limit of the TD stretching temperature is preferably 110 ° C, more preferably 120 ° C, and even more preferably 125 ° C. If the temperature is lower than 110 ° C., the stretching stress in the lateral direction becomes high, the film may be broken, and the thickness unevenness may become extremely large, which is not very preferable.
• the upper limit is preferably 150 ° C, more preferably 145 ° C, and even more preferably 140 ° C. If the temperature exceeds 150 ° C., the orientation of the molecular chains does not increase, so that the mechanical properties may deteriorate, which is not very preferable.
• the lower limit of the lateral (TD) draw ratio is preferably 3.5 times, more preferably 3.9 times. If it is less than 3.5 times, the molecular orientation is weak and the mechanical strength may be insufficient, which is not very preferable. Further, the orientation of the molecular chains in the vertical direction is large, and the balance between the vertical and horizontal directions becomes poor, so that the thickness unevenness becomes large, which is not very preferable.
• the upper limit is preferably 5.5 times, more preferably 4.5 times. If it exceeds 5.5 times, it may break, which is not very preferable.
• a polyester film containing a recycled resin made of a PET bottle containing isophthalic acid has lower crystallinity than a normal polyethylene terephthalate film containing no isophthalic acid, is easily melted to a very small size, and has mechanical strength. Low. Therefore, if the film is suddenly exposed to high temperature under tension after the end of stretching, or if it is cooled under sudden tension after the end of high-temperature heat fixation, the tension balance in the width direction is disturbed due to the unavoidable temperature difference in the width direction of the film.
• the method is not limited to this method, for example, a method of controlling the film tension according to the speed of hot air in the tenter and the temperature of each zone, and a heat treatment at a relatively low temperature in which the furnace length is sufficient after the stretching is completed. And a method of relaxing with a heating roll after the heat treatment is completed.
• Heat fixing 1, 2, and 3 are arranged in order from the upstream side in the film flow direction of the heat fixing zone in the tenter.
• the lower limit of the temperature of the heat fixation 1 is preferably 160 ° C, more preferably 170 ° C. If the temperature is lower than 160 ° C., the heat shrinkage rate will eventually increase, which may cause misalignment or shrinkage during processing, which is not very preferable.
• the upper limit is preferably 215 ° C, more preferably 210 ° C. If the temperature exceeds 215 ° C., a high temperature is suddenly applied to the film, which may increase the thickness unevenness or break the film, which is not very preferable.
• the lower limit of the time for heat fixing 1 is preferably 0.5 seconds, more preferably 2 seconds. If it is less than 0.5 seconds, the film temperature may not rise sufficiently.
• the upper limit is preferably 10 seconds, more preferably 8 seconds. If it exceeds 10 seconds, productivity may decrease, which is not very preferable.
• the lower limit of the temperature of the heat fixing 2 is preferably 220 ° C, more preferably 227 ° C. If the temperature is lower than 220 ° C., the heat shrinkage rate becomes large, which may cause deviation or shrinkage during processing, which is not very preferable.
• the upper limit is preferably 240 ° C, more preferably 237 ° C. If the temperature exceeds 240 ° C., the film may melt, and even if it does not melt, it may become brittle, which is not very preferable.
• the lower limit of the heat fixing 2 time is preferably 0.5 seconds, more preferably 3 seconds. If it is less than 0.5 seconds, it may easily break during heat fixing, which is not very preferable.
• the upper limit is preferably 10 seconds, more preferably 8 seconds. If it exceeds 10 seconds, slack or the like may occur and uneven thickness may occur, which is not very preferable.
• the lower limit of the temperature when the heat fixing 3 is provided is preferably 205 ° C, more preferably 220 ° C. If the temperature is lower than 205 ° C., the heat shrinkage rate becomes large, which may cause deviation or shrinkage during processing, which is not very preferable.
• the upper limit is preferably 240 ° C, more preferably 237 ° C. If the temperature exceeds 240 ° C., the film will melt, and even if it does not melt, it may become brittle, which is not very preferable.
• the lower limit of the time when the heat fixing 3 is provided is preferably 0.5 seconds, more preferably 3 seconds. If it is less than 0.5 seconds, it may easily break during heat fixing, which is not very preferable.
• the upper limit is preferably 10 seconds, more preferably 8 seconds. If it exceeds 10 seconds, slack may occur and uneven thickness may occur, which is not very preferable.
• TD relaxation can be performed at any location where heat is fixed.
• the lower limit is preferably 0.5% and more preferably 3%. If it is less than 0.5%, the heat shrinkage rate in the lateral direction becomes particularly large, which may cause deviation or shrinkage during processing, which is not very preferable.
• the upper limit is preferably 10%, more preferably 8%. If it exceeds 10%, slack may occur and uneven thickness may occur, which is not very preferable.
• the lower limit of the slow cooling temperature after TD heat fixing is preferably 90 ° C, more preferably 100 ° C. If the temperature is lower than 90 ° C., the film contains isophthalic acid, so that the film may have a large thickness unevenness or breakage due to shrinkage due to a sudden temperature change, which is not very preferable.
• the upper limit of the slow cooling temperature is preferably 150 ° C, more preferably 140 ° C. If the temperature exceeds 150 ° C, a sufficient cooling effect may not be obtained, which is not very preferable.
• the lower limit of the slow cooling time after heat fixing is preferably 2 seconds, more preferably 4 seconds. If it is less than 2 seconds, a sufficient slow cooling effect may not be obtained, which is not very preferable.
• the upper limit is preferably 20 seconds, more preferably 15 seconds. If it exceeds 20 seconds, it tends to be disadvantageous in terms of productivity, which is not very preferable.
• the upper limit of the haze per thickness of the base film layer in the present invention is preferably 0.66% / ⁇ m, more preferably 0.60% / ⁇ m, and further preferably 0.53% / ⁇ m.
• the base film layer in the present invention may be subjected to corona discharge treatment, glow discharge treatment, flame treatment, surface roughening treatment, as long as the object of the present invention is not impaired, and a known anchor coat may be applied. It may be processed, printed, decorated, etc.
• a layer of another material may be laminated on the base film layer in the present invention, and as a method thereof, the base film layer can be bonded after production or during film formation.
• the gas barrier laminated film of the present invention has an inorganic thin film layer on the surface of the base film layer.
• the inorganic thin film layer is a thin film made of a metal or an inorganic oxide.
• the material for forming the inorganic thin film layer is not particularly limited as long as it can be made into a thin film, but from the viewpoint of gas barrier properties, inorganic oxidation such as silicon oxide (silica), aluminum oxide (alumina), and a mixture of silicon oxide and aluminum oxide Things are preferred.
• the mixing ratio of silicon oxide and aluminum oxide is preferably in the range of 20 to 70% by mass of Al in terms of the mass ratio of the metal content. If the Al concentration is less than 20% by mass, the water vapor barrier property may be lowered.
• the inorganic thin film layer tends to be hard, and the film may be destroyed during secondary processing such as printing or laminating, and the gas barrier property may be lowered.
• the Al concentration 100% by mass, the water vapor barrier performance is good, but since it is a single material, the surface tends to be smooth, the slipperiness is poor, and processing defects (wrinkles, acne, etc.) occur. It is easy to occur.
• the silicon oxide referred to here is various silicon oxides such as SiO and SiO 2 or a mixture thereof
• aluminum oxide is various aluminum oxides such as AlO and Al 2 O 3 or a mixture thereof.
• the film thickness of the inorganic thin film layer is usually 1 to 100 nm, preferably 5 to 50 nm. If the film thickness of the inorganic thin film layer is less than 1 nm, it may be difficult to obtain a satisfactory gas barrier property. On the other hand, even if the thickness exceeds 100 nm, the corresponding improvement effect of the gas barrier property can be obtained. This is not possible, and it is rather disadvantageous in terms of bending resistance and manufacturing cost.
• the method for forming the inorganic thin film layer is not particularly limited, and is known, for example, a physical vapor deposition method (PVD method) such as a vacuum vapor deposition method, a sputtering method, or an ion plating method, or a chemical vapor deposition method (CVD method).
• PVD method physical vapor deposition method
• CVD method chemical vapor deposition method
• the method may be adopted as appropriate.
• a typical method for forming the inorganic thin film layer will be described by taking a silicon oxide / aluminum oxide thin film as an example.
• a mixture of SiO 2 and Al 2 O 3 or a mixture of SiO 2 and Al is preferably used as the vapor deposition raw material.
• Particles are usually used as these vapor deposition raw materials, but at that time, it is desirable that the size of each particle is such that the pressure at the time of vapor deposition does not change, and the particle size is preferably 1 mm to 5 mm.
• heating methods such as resistance heating, high frequency induction heating, electron beam heating, and laser heating can be adopted.
• oxygen, nitrogen, hydrogen, argon, carbon dioxide gas, water vapor or the like as the reaction gas, or to adopt reactive vapor deposition using means such as ozone addition and ion assist.
• the film forming conditions can be arbitrarily changed, such as applying a bias to the film to be vapor-deposited (laminated film to be subjected to vapor deposition) or heating or cooling the film to be vapor-deposited.
• a bias to the film to be vapor-deposited (laminated film to be subjected to vapor deposition) or heating or cooling the film to be vapor-deposited.
• Such vapor deposition material, reaction gas, bias of the vapor deposition body, heating / cooling, and the like can be similarly changed when the sputtering method or the CVD method is adopted.
• a coating layer can be provided between the base film layer and the inorganic thin film layer for the purpose of ensuring gas barrier properties and lamination strength after retort treatment.
• the resin composition used for the coating layer provided between the base film layer and the inorganic thin film layer includes urethane-based, polyester-based, acrylic-based, titanium-based, isocyanate-based, imine-based, polybutadiene-based resins, and epoxy. Examples thereof include those to which a curing agent such as a system, an isocyanate system, a melamine system, an oxazoline system, or a carbodiimide system is added.
• the resin composition used for these coating layers preferably contains a silane coupling agent having at least one type of organic functional group.
• organic functional group include an alkoxy group, an amino group, an epoxy group, an isocyanate group and the like.
• the resin compositions used for the coating layer it is preferable to use a resin containing an oxazoline group or a carbodiimide group, and it is more preferable to use a mixture of an acrylic resin and a urethane resin in addition to these.
• These functional groups have a high affinity with the inorganic thin film, and can react with the oxygen-deficient portion of the inorganic oxide generated during the formation of the inorganic thin film layer and the metal hydroxide, and have strong adhesion to the inorganic thin film layer. Is shown. Further, the unreacted functional group existing in the coating layer can react with the carboxylic acid terminal generated by hydrolysis of the base film layer and the coating layer to form a crosslink.
• the amount of adhesion of the coating layer is preferably 0.010 to 0.200 (g / m 2).
• the coating layer can be uniformly controlled, and as a result, the inorganic thin film layer can be densely deposited.
• the cohesive force inside the coating layer is improved, and the adhesion between each layer of the base film-coating layer-inorganic thin film layer is also increased, so that the water resistance and adhesion of the coating layer can be enhanced.
• the adhesion amount of the coating layer is preferably 0.015 (g / m 2 ) or more, more preferably 0.020 (g / m 2 ) or more, and further preferably 0.025 (g / m 2 ) or more.
• the coating layer is preferably 0.190 (g / m 2 ) or less, more preferably 0.180 (g / m 2 ) or less, and even more preferably 0.170 (g / m 2 ) or less. If the amount of adhesion of the coating layer exceeds 0.200 (g / m 2 ), the cohesive force inside the coating layer becomes insufficient, and good adhesion may not be exhibited. In addition, since the uniformity of the coating layer is also lowered, defects may occur in the inorganic thin film layer, and the gas barrier property may be lowered. Further, if the coating layer is thick, the softening effect of the base material is weakened, which leads to deterioration of the gas barrier property. Moreover, the manufacturing cost becomes high, which is economically disadvantageous. On the other hand, if the film thickness of the coating layer is less than 0.010 (g / m 2 ), the substrate may not be sufficiently coated, and sufficient gas barrier properties and interlayer adhesion may not be obtained.
• the method for forming the coating layer is not particularly limited, and a conventionally known method such as a coating method can be adopted.
• the offline coating method and the inline coating method can be mentioned as preferable methods.
• the conditions of drying and heat treatment at the time of coating depend on the coating thickness and the conditions of the apparatus, but immediately after coating, they are sent to the stretching process in the perpendicular direction. It is preferable to dry in the preheating zone or the stretching zone of the stretching step, and in such a case, the temperature is usually preferably about 50 to 250 ° C.
• solvent examples include aromatic solvents such as benzene and toluene; alcohol solvents such as methanol and ethanol; ketone solvents such as acetone and methyl ethyl ketone; ethyl acetate and butyl acetate.
• Etc. examples thereof include polyhydric alcohol derivatives such as ethylene glycol monomethyl ether.
• a protective layer is provided on the inorganic thin film layer.
• the metal oxide layer is not a completely dense film, but is dotted with minute defects.
• the resin in the protective layer resin composition permeates the defective portion of the metal oxide layer.
• the effect of stabilizing the gas barrier property can be obtained.
• the gas barrier performance of the laminated film is greatly improved.
• the laminated laminate after use can be easily separated by utilizing the fact that the protective layer easily swells in a specific solvent.
• a resin having a urethane skeleton is used as the resin composition used for the protective layer formed on the surface of the inorganic thin film layer of the laminated film of the present invention.
• the urethane resin content has barrier performance due to the high cohesiveness of the urethane bond itself, as well as the polar groups interacting with the inorganic thin film layer and having flexibility due to the presence of amorphous parts, so when a bending load is applied. It is also preferable because it can suppress damage to the inorganic thin film layer.
• urethane resin has the property of swelling and solubility in alcohol-based solvents due to its solubility parameter, a laminated laminate is used using an alcohol-based solvent, which is an inexpensive organic solvent with a relatively small environmental load. The laminated film can be easily peeled off from the solvent. Since each peeled film is a single material, it can be recycled.
• the surface free energy of the protective layer in the present invention is preferably 45 to 60 mN / m. It is more preferably 46 to 59 mN / m, still more preferably 47 to 58 mN / m or more.
• the protective layer By setting the surface free energy within the above range, it has good gas barrier properties and adhesiveness before and after moist heat treatment such as boiling, and at the same time, the protective layer easily swells and easily peels off when immersed in alcohol. Can be done.
• it When it is 45 mN / m or less, it becomes a hydrophobic protective layer, so that the moisture and heat resistance is improved, but the alcohol swelling property is inferior.
• the alcohol swelling property is excellent, but the moisture and heat resistance may decrease.
• urethane resin From the viewpoint of improving the gas barrier property, it is more preferable to use a urethane resin containing an aromatic or aromatic aliphatic diisocyanate component as a main component. Among them, it is particularly preferable to contain a tolylene diisocyanate or a metaxylylene diisocyanate component.
• the cohesive force of the urethane bond can be further enhanced by the stacking effect of the aromatic rings, and as a result, a good gas barrier property can be obtained. Further, the cohesive force of the urethane bond is composed of hydrogen bonds, and when exposed to a highly permeable alcohol-based solvent, the bonds are dissociated and easily swell.
• the adhesive strength of the protective layer is reduced, and the film can be easily peeled off by using the protective layer as a trigger.
• the alcohol solvent include ethanol, 2-propanol, 1-methoxy-2 propanol and the like. These solvents have a solubility parameter SP value (Solubility parameter) of 9 to 13, which is close to the SP value of a general urethane resin, which is around 10, so that they are easily mixed, swollen, and easily mixed.
• SP value solubility parameter
• 1-methoxy-2 propanol is suitable because its SP value is around 10, which is almost the same as urethane.
• the ratio of aromatic or aromatic aliphatic diisocyanate in the urethane resin is preferably in the range of 50 mol% or more (50 to 100 mol%) in 100 mol% of the isocyanate component.
• the ratio of the total amount of the aromatic or aromatic aliphatic diisocyanate is preferably 60 to 100 mol%, more preferably 70 to 100 mol%, still more preferably 80 to 100 mol%. If the proportion of the total amount of aromatic or aromatic aliphatic diisocyanates is less than 50 mol%, good gas barrier properties may not be obtained.
• the urethane resin used in the present invention preferably has a glass transition temperature (Tg) of 10 ° C. or higher, more preferably 20 ° C. or higher, and even more preferably 30 ° C. or higher, from the viewpoint of improving the barrier property due to the cohesive force.
• the glass transition temperature (Tg) is preferably 140 ° C. or lower, more preferably 130 ° C. or lower, still more preferably 120 ° C. or lower. If Tg is out of the above range, cohesive force and flexibility / swelling property cannot be achieved at the same time, barrier property or adhesion may be poor, and easy peeling by immersion in an alcohol solvent is also obtained. I can't.
• the amount of the protective layer adhered is 0.10 to 0.40 (g / m 2 ).
• the protective layer can be uniformly controlled during coating, resulting in a film having less coating unevenness and defects.
• the cohesive force of the protective layer itself is improved, and the adhesion between the inorganic thin film layer and the protective layer is also strengthened.
• the amount of the protective layer adhered is preferably 0.13 (g / m 2 ) or more, more preferably 0.16 (g / m 2 ) or more, and further preferably 0.19 (g / m 2 ) or more.
• It is preferably 0.37 (g / m 2 ) or less, more preferably 0.34 (g / m 2 ) or less, and even more preferably 0.31 (g / m 2 ) or less.
• the amount of adhesion of the protective layer exceeds 0.400 (g / m 2 )
• the gas barrier property is improved, but the cohesive force inside the protective layer is insufficient and the uniformity of the protective layer is also lowered, so that the appearance of the coat is improved. In some cases, unevenness or defects may occur, or gas barrier properties and adhesiveness may not be sufficiently exhibited.
• the film thickness of the protective layer is less than 0.10 (g / m 2 ), sufficient gas barrier properties and interlayer adhesion may not be obtained.
• the coating method of the resin composition for the protective layer is not particularly limited as long as it is a method of coating the film surface to form a layer.
• ordinary coating methods such as gravure coating, reverse roll coating, wire bar coating, and die coating can be adopted.
• the drying temperature at that time is preferably 110 to 190 ° C, more preferably 130 to 185 ° C, still more preferable. Is 150 to 180 ° C. If the drying temperature is less than 110 ° C., the protective layer may be insufficiently dried, or the protective layer may not be formed and the cohesive force and water-resistant adhesiveness may be lowered, resulting in a decrease in barrier property and hand-cutting property. There is.
• the film may be overheated and the film may become brittle, resulting in a decrease in piercing strength or shrinkage, resulting in poor workability.
• the film formation of the protective layer progresses effectively, and the adhesive area between the resin of the protective layer and the inorganic thin film layer becomes larger, so that the water resistance is improved. can do.
• the protective film is particularly preferable when the solvent is first volatilized under relatively low temperature conditions of 90 ° C. to 110 ° C. and then dried at 150 ° C. or higher because a uniform film can be obtained. Further, apart from drying, applying an additional heat treatment in a low temperature region as much as possible is more effective in advancing the film formation of the protective layer.
• the heat-sealing resin layer is usually provided on the inorganic thin film layer, but may be provided on the outside of the base film layer (the surface opposite to the coating layer forming surface).
• the heat-sealing resin layer is usually formed by an extrusion laminating method or a dry laminating method.
• the thermoplastic polymer that forms the heat-sealable resin layer may be any as long as it can sufficiently exhibit sealant adhesiveness, and is a polyethylene resin such as HDPE, LDPE, LLDPE, a polypropylene resin, or an ethylene-vinyl acetate copolymer.
• the thickness of the sealant layer is preferably 20 to 100 ⁇ m, more preferably 30 to 90 ⁇ m, and even more preferably 40 to 80 ⁇ m. If the thickness is thinner than 20 ⁇ m, sufficient sealing strength may not be obtained, and there is a possibility that it is difficult to handle because there is no feeling of stiffness. On the other hand, if the thickness exceeds 100 ⁇ m, the feeling of waist is strong and the handleability as a bag is deteriorated, and the price may be high.
• Adhesive layer As the adhesive layer used in the present invention, a general-purpose adhesive for laminating can be used. For example, poly (ester) urethane type, polyester type, polyamide type, epoxy type, poly (meth) acrylic type, polyethylene imine type, ethylene- (meth) acrylic acid type, polyvinyl acetate type, (modified) polyolefin type, polybutagen.
• a solvent-based (non-) solvent-based, water-based, or heat-melting type adhesive containing a system, a wax system, a caseine system, or the like as a main component can be used.
• urethane-based or polyester-based materials are preferable in consideration of moisture and heat resistance that can withstand retort treatment and flexibility that can follow dimensional changes of each base material.
• the method for laminating the adhesive layer include a direct gravure coating method, a reverse gravure coating method, a kiss coating method, a die coating method, a roll coating method, a dip coating method, a knife coating method, a spray coating method, a fonten coating method, and the like.
• the coating amount after drying is preferably 1 to 8 g / m 2 because it can be applied by the method described in the above method and exhibits sufficient adhesiveness even after moist heat treatment.
• the coating amount is less than 1 g / m 2 , it becomes difficult to bond the entire surface, and the adhesive strength is lowered. On the other hand, if it exceeds 8 g / m2, it takes time to completely cure the film, unreacted substances are likely to remain, and the adhesive strength is lowered.
• At least one layer of a printing layer or another plastic base material and / or a paper base material is provided between or outside the inorganic thin film layer or the base film layer and the heat-sealing resin layer.
• the above may be laminated.
• water-based and solvent-based resin-containing printing inks can be preferably used.
• the resin used for the printing ink include acrylic resins, urethane resins, polyester resins, vinyl chloride resins, vinyl acetate copolymer resins, and mixtures thereof.
• Known printing inks include antistatic agents, light blocking agents, UV absorbers, plasticizers, lubricants, fillers, colorants, stabilizers, lubricants, antifoaming agents, cross-linking agents, blocking agents, antioxidants and the like. Additives may be included.
• the printing method for providing the print layer is not particularly limited, and known printing methods such as an offset printing method, a gravure printing method, and a screen printing method can be used.
• known drying methods such as hot air drying, hot roll drying, and infrared drying can be used.
• the laminate of the present invention has good gas barrier properties when the oxygen permeability under the conditions of 23 ° C. ⁇ 65% RH before and after the boiling treatment at 90 ° C. ⁇ 30 minutes is 20 ml / m 2 ⁇ d ⁇ MPa or less. It is preferable in that it is expressed. Further, by controlling the above-mentioned inorganic thin film layer component / adhesion amount, it can be preferably 15 ml / m 2 ⁇ d ⁇ MPa or less, more preferably 10 ml / m 2 ⁇ d ⁇ MPa or less. If the oxygen permeability exceeds 20 ml / m2 ⁇ d ⁇ MPa, it becomes difficult to meet applications requiring high gas barrier properties.
• the oxygen permeability before and after the retort treatment is less than 1 ml / m 2 ⁇ d ⁇ MPa, the barrier performance is excellent, but the residual solvent is difficult to permeate to the outside of the bag, and the residue is relatively transferred to the contents. It is not preferable because the amount of migration may increase.
• the preferable lower limit of oxygen permeability is 1 ml / m 2 ⁇ d ⁇ MPa or more.
• the laminate strength of the laminate of the present invention is preferably 1.5 N / 15 mm or more, more preferably 1.8 N / 15 mm, under the conditions of 23 ° C. ⁇ 65% RH before and after the boiling treatment at 90 ° C. ⁇ 30 minutes. Above, more preferably 2.0 N / 15 mm or more. If the laminate strength is less than 1.5 N / 15 mm, peeling may occur due to a bending load or the liquid content, which may deteriorate the barrier property or leak the content. Further, the hand-cutting property may be deteriorated.
• the laminate of the present invention preferably has a laminate strength of 1.0 N / 15 mm or less, more preferably 0.9 N, after being immersed in 1-methoxy-2-propanol, which is an alcohol solvent, at 40 ° C. for 72 hours. / 15 mm or less, more preferably 0.8 N / 15 mm or less. If the laminate strength exceeds 1.0 N / 15 mm, it becomes difficult to easily peel it off from the laminate laminate, and there is a concern that the recyclability is inferior. By raising the temperature at the time of immersion or lengthening the time, further reduction in the lamination strength can be expected, and the peeling can be performed more easily.
• the preferred temperature for solvent immersion in the present invention is 10 to 60 ° C, more preferably 15 to 55 ° C, and even more preferably 20 to 50 ° C. If the temperature is lower than 10 ° C., it becomes difficult for the solvent to be immersed in the laminate, and there is a risk that the solvent cannot be easily peeled off. On the other hand, when the temperature is higher than 60 ° C., 1-methoxy-2-propanol may be volatilized and the immersion liquid may be reduced, which is not preferable in terms of economy and safety.
• the humidity at the time of solvent immersion in the present invention is not particularly limited, but is preferably 10 to 80% RH, more preferably 15 to 75% RH, and even more preferably 20 to 70% RH under a general environment.
• Humidity control equipment is required to create a humidity environment of less than 10% RH or greater than 80% RH, which may increase management and processing costs.
• the preferable solvent immersion time in the present invention is 12 to 72 hours. It is more preferably 24 to 60 hours, still more preferably 36 to 48 hours. If the immersion time is less than 12 hours, the solvent may not sufficiently penetrate into the laminate and may not be easily peeled off. On the other hand, if it exceeds 72 hours, the processing time becomes too long, which may not be an effective method in terms of efficiency.
• the ratio of the recycled PET resin (referred to as the recycling ratio) to the total weight of the laminate is preferably 3% or more. It is more preferably 5% or more, still more preferably 10% or more. If the recycling ratio is less than 3%, the recycling resin usage rate is low, and it may not be possible to say that the film has a small environmental load.
• the laminated laminate of the present invention is a film having excellent barrier properties and adhesiveness even after harsh moist heat treatment and having excellent recyclability that allows the laminated film to be easily peeled off from the laminated laminate while using a recycled material. Can be provided.
• Thickness of base film The thickness of the base film was measured using a dial gauge in accordance with the JIS K7130-199 A method.
• each laminated film obtained at the stage of laminating the protective layer on the base film was used as a sample, and a 100 mm ⁇ 100 mm test piece was cut out from this sample.
• the protective layer was wiped with dimethylformamide, and the amount of adhesion was calculated from the change in mass of the film before and after wiping.
• a polyurethane-based adhesive (TM569 manufactured by Toyobo Co., Ltd.) was applied to the protective layer surface of the laminated films obtained in Examples and Comparative Examples so that the thickness after drying at 80 ° C. was 3 ⁇ m, and then linear low density.
• a polyethylene film (L4102 manufactured by Toyobo; thickness 40 ⁇ m; LL) is dry-laminated on a metal roll heated to 60 ° C. and aged at 40 ° C. for 4 days to evaluate a laminated gas barrier laminate (hereinafter referred to as LL). (Sometimes referred to as "laminated laminate a”) was obtained.
• laminated laminate b A polyurethane-based adhesive (TM569 manufactured by Toyo Morton Co., Ltd.) was applied to the protective layer surface of the laminated films obtained in Examples and Comparative Examples so that the thickness after drying at 80 ° C. would be 3 ⁇ m, and then a non-stretched polypropylene film (Non-stretched polypropylene film).
• Toyobo P1176; thickness 70 ⁇ m; CPP) is dry-laminated on a metal roll heated to 60 ° C. and aged at 40 ° C. for 4 days to evaluate a laminated gas barrier laminate (hereinafter referred to as “laminate laminate”). (Sometimes referred to as body b) was obtained.
• Oxygen Permeability Evaluation Method For the laminated laminate produced in the above [Preparation of Laminate Laminate], an oxygen permeability measuring device (MOCON's "OX-TRAN (registered trademark)" is applied according to the JIS-K7126 B method. ) 1/50 ”) was used to measure the normal oxygen permeability in an atmosphere of a temperature of 23 ° C. and a humidity of 65% RH. The oxygen permeability was measured in the direction in which oxygen permeated from the base film side of the laminated laminate to the heat-sealing resin layer side.
• the laminated laminate prepared in the above [Preparation of laminated laminate] is subjected to a wet heat treatment for holding it in hot water at 90 ° C. for 30 minutes, and dried at 40 ° C. for 1 day (24 hours) to obtain the obtained product.
• the oxygen permeability (after boiling) was measured in the same manner as above for the laminated laminate after the moist heat treatment.
• the laminated laminate produced above was boiled for 30 minutes while being kept in pressurized hot water at a temperature of 90 ° C., and immediately after the obtained laminated laminate after the retort treatment, the same as above was applied.
• the test piece was cut out and the laminate strength (after boiling treatment) was measured in the same manner as described above.
• Carbodiimide-based cross-linking agent (A) As a carbodiimide-based cross-linking agent, a commercially available "carbodilite (registered trademark) SV-02" manufactured by Nisshinbo Holdings Co., Ltd .; solid content 40%) was prepared.
• Resin having an oxazoline group (B) As a resin having an oxazoline group, a commercially available water-soluble oxazoline group-containing acrylate (“Epocross (registered trademark) WS-300” manufactured by Nippon Shokubai Co., Ltd .; solid content 10%) was prepared. The amount of oxazoline groups in this resin was 7.7 mmol / g.
• acrylic resin (C) As the acrylic resin, a 25% by mass emulsion of a commercially available acrylic acid ester copolymer (“Mobile (registered trademark) 7980” manufactured by Nichigo Vinyl Co., Ltd.) was prepared.
• urethane resin (D) As the urethane resin, a commercially available polyester urethane resin dispersion (“Takelac (registered trademark) W605” manufactured by Mitsui Chemicals, Inc .; solid content 30%) was prepared. The glass transition temperature (Tg) measured by DSC was 100 ° C. The ratio of aromatic or aromatic aliphatic diisocyanate to the total isocyanate component measured by 1H-NMR was 55 mol%.
• Silane Coupling Agent (E) As a silane coupling agent, a commercially available "(registered trademark) KBM903" manufactured by Shin-Etsu Chemical Co., Ltd .; 100% solid content) was prepared. At the time of use, it was diluted with water to make a 2% aqueous solution.
• urethane resin (F) As the urethane resin, a commercially available polyester urethane resin dispersion (“Takelac (registered trademark) WPB341” manufactured by Mitsui Chemicals, Inc .; solid content 30%) was prepared. The glass transition temperature (Tg) measured by DSC was 130 ° C. The ratio of aromatic or aromatic aliphatic diisocyanate to the total isocyanate component measured by 1H-NMR was 85 mol%.
• urethane resin (G) As the urethane resin, a commercially available polyester urethane resin dispersion (“AP201” manufactured by DIC Corporation; solid content 23%) was prepared. The glass transition temperature (Tg) measured by DSC was 10 ° C. The ratio of aromatic or aromatic aliphatic diisocyanate to the total isocyanate component measured by 1H-NMR was 100 mol%.
• Gas barrier vinyl alcohol resin (H) As a vinyl alcohol-based resin having a gas barrier property, a commercially available water-soluble vinyl alcohol resin (“Nichigo G-Polymer (registered trademark) OKS-8049” manufactured by Nippon Synthetic Chemical Industry Co., Ltd .; powder) is dissolved in water and has a solid content of 5%. An aqueous solution was prepared.
• Gas barrier protective layer solution (coating liquid 6)
• the solution was prepared as a gas barrier protective layer solution (coating liquid 6).
• Coating liquid 1 used for coating layer Each material was mixed at the following blending ratio to prepare a coating liquid (resin composition for coating layer).
• Coating liquid 2 used for coating layer Each material was mixed at the following blending ratio to prepare a coating liquid (resin composition for coating layer).
• Coating liquid 3 used for coating the protective layer The following coating agents were mixed to prepare a coating liquid 3. Water 30.00% by mass Isopropanol 30.00% by mass Urethane resin (F) 40.00% by mass
• coating liquid used for coating the protective layer 4 The following coating agents were mixed to prepare a coating liquid 4. Water 17.83% by mass Isopropanol 30.00% by mass Urethane resin (G) 52.17% by mass
• Coating liquid 5 used for coating the protective layer The following coating agents were mixed to prepare a coating liquid 5.
• Coating liquid 7 used for coating the protective layer The following coating agents were mixed to prepare a coating liquid 7.
• Coating liquid 8 used for coating the protective layer The following coating agents were mixed to prepare a coating liquid 8. Water 22.00% by mass Isopropanol 30.00% by mass Acrylic resin (C) 48.00% by mass
• polyester recycled raw material was obtained by filtering with a filter having the smallest opening size of 50 ⁇ m for the third time.
• the melt extruded from the T-die was brought into close contact with a cooling roll to form an unstretched sheet, which was subsequently heated to 118 ° C. and stretched 1.41 times in the longitudinal direction with a roll having a peripheral speed difference (MD1). Further, it was stretched 2.92 times (MD2) in the longitudinal direction with a roll heated to 128 ° C. and having a difference in peripheral speed.
• MD1 peripheral speed difference
• MD2 peripheral speed difference
• the vertically stretched sheet was guided to a tenter, and the coating liquid 1 was coated on one side of the film by the fountain bar coating method. It was led to a tenter while drying, preheated at 121 ° C., and then laterally stretched 4.3 times at 131 ° C. As heat fixation, 180 ° C.
• the continuous vacuum deposition machine is depressurized to 10-4 Torr or less, metallic aluminum having a purity of 99.99% is loaded into an alumina crucible from the lower part of the cooling drum, the metallic aluminum is heated and evaporated, and oxygen is contained in the vapor. Was supplied and deposited on the film while undergoing an oxidation reaction to form an aluminum oxide film having a thickness of 10 nm.
• the above-prepared coating liquid was applied onto the inorganic thin film layer of the obtained vapor-deposited film by a gravure roll coating method, pre-dried at 110 ° C., and then main-dried at 180 ° C. to obtain a protective layer.
• the coating amount after drying was 0.30 g / m 2 (Dry).
• heat treatment was performed after 2 days at 40 degreeC.
• the coating liquid constituting the protective layer was changed as shown in Table 1 in each Example and Comparative Example.
• a polyester resin derived from a PET bottle having a low environmental load is used as a base material, and a structure having a specific coating layer or a specific barrier protective layer having excellent flexibility and adhesiveness to an inorganic thin film layer is formed. It has been found that the gas barrier performance before treatment can be improved and the barrier property and adhesiveness can be maintained even after harsh wet heat treatment. Furthermore, they have found that the laminated film can be easily peeled off from the laminated laminate by utilizing the property that the protective layer dissolves when immersed in a specific solvent, and completed the present invention. Since the laminated laminate of the present invention can be easily manufactured with few processing steps and is also excellent in recyclability, it is excellent in both economic efficiency and production stability, and it is possible to provide a gas barrier film having uniform characteristics. ..

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• 2021
  • 2021-04-07 US US17/996,067 patent/US20230191763A1/en not_active Abandoned
  • 2021-04-07 WO PCT/JP2021/014776 patent/WO2021210466A1/ja not_active Ceased
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  • 2021-04-07 EP EP21789090.4A patent/EP4137310A4/en not_active Withdrawn
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