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
  • B32B27/32—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
  • B32B27/06—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
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
  • B32B27/20—Layered products comprising a layer of synthetic resin characterised by the use of special additives using fillers, pigments, thixotroping agents
• • 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
  • B32B7/027—Thermal properties
• • 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
  • B32B2264/00—Composition or properties of particles which form a particulate layer or are present as additives
  • B32B2264/10—Inorganic particles
  • B32B2264/102—Oxide or hydroxide
  • B32B2264/1021—Silica
• • 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
  • B32B2323/00—Polyalkenes
  • B32B2323/10—Polypropylene
• • 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
  • B32B2435/00—Closures, end caps, stoppers
  • B32B2435/02—Closures, end caps, stoppers for containers

Definitions

• the present invention relates to a laminated sealant film that has excellent bag-making properties, low-temperature bag-making properties, and excellent seal strength.
• Packaging materials have been developed to suit the contents of many products, including food, beverages, pharmaceuticals, and chemicals. Packaging materials are used in a variety of forms, such as pillow packaging, gusset packaging, and three-sided sealed packaging, and the sealant films used in packaging materials also have the functions required for their use.
• Sealant films are particularly suitable for automatic bag making processing into pillowcase bags, gusset bags, or three-sided sealed bags while packaging the contents, and the lower the temperature at which heat sealing can be performed, the lower the electricity bill will be, and the easier the work will be, as there will be less risk of burns.
• the ability to heat seal at low temperatures will increase the speed of packaging and bag making, reduce the loss of packaging materials, and result in a neater finished packaging bag.
• a sealant film is required to have various functions, such as smooth packaging and bag-making processes, and good airtightness and seal strength of the resulting packaging bags.
• the seal strength is sufficient even immediately after heat sealing when the resin of the sealant film is in a molten state, and that the seal does not peel off even when subjected to the impact of pressure that occurs when filling the bag with heavy contents.
• the object of the present invention is to provide a sealant film containing propylene-based resin and polyethylene-based resin that has excellent low-temperature bag-forming properties and burst strength.
• the laminated sealant film according to the present invention has the following configuration.
• a laminated sealant film that satisfies all of the following requirements 1) to 9). 1) It includes at least a laminate layer and a seal layer. 2) The laminate layer is made of a resin composition containing a polypropylene-based resin as a main component. 3) The sealing layer is made of a resin composition containing as a main component a mixture of a polypropylene-based resin and a polyethylene-based resin. 4) The sealing layer contains 1% by weight or more and 95% by weight or less of polypropylene resin and 5% by weight or more and 99% by weight or less of polyethylene resin, based on 100% by weight of the mixture of polypropylene resin and polyethylene resin constituting the sealing layer.
• the polyethylene resin constituting the sealing layer contains 90% by weight or more of linear low-density polyethylene resin.
• the difference in melting point between the polypropylene resin and the linear low-density polyethylene resin in the sealing layer is 15° C. or more.
• the ratio of the melt flow rate of the polypropylene resin to the melt flow rate of the linear low density polyethylene resin in the sealing layer is 0.8 or more and 2.0 or less.
• the melt flow rate of the polypropylene resin and linear low-density polyethylene resin in the sealing layer is 9 g/10 min (load 2.16 kg) or less.
• the tensile modulus in the longitudinal direction is 500 MPa or less.
• the laminated sealant film of the present invention has excellent low-temperature bag-making properties, making it suitable as a packaging material for many products, such as food, beverages, pharmaceuticals, and chemicals. It is particularly suitable for automatic bag-making processing into pillow packaging bags, gusset packaging bags, and three-sided seal packaging bags while packaging the contents.
• the laminated sealant film of the present invention includes at least a laminate layer and a seal layer.
• the laminate layer and seal layer will be described in detail below.
• the sealing layer in the present invention is made of a resin composition containing as a main component a mixture of a polypropylene-based resin and a polyethylene-based resin.
• the term "main component” means that the mixture of polypropylene-based resin and polyethylene-based resin accounts for 90% by mass or more in the resin composition, but it is more preferable that it is 95% by weight or more, even more preferable that it is 97% by weight or more, and even more preferable that it is 99% by weight or more.
• the polypropylene-based resin in the seal layer is a resin containing propylene as a main component, and examples thereof include propylene homopolymers, random copolymers and block copolymers of propylene and ⁇ -olefins such as ethylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, and octene-1.
• the term "main component" means that the proportion of propylene in the polypropylene resin is 90% by mass or more, more preferably 95% by weight or more, even more preferably 97% by weight or more, and even more preferably 99% by weight or more.
• Polypropylene-based resins have a higher melting point and are more transparent than polyethylene-based resins.
• the polypropylene-based resin constituting the sealing layer preferably has a melt flow rate of 0.1 g/10 min or more and 9 g/10 min or less, more preferably 0.5 g/10 min or more and 8 g/10 min or less, and even more preferably 1 g/10 min or more and 7 g/10 min or less.
• the polypropylene resin constituting the seal layer preferably has a melting point of 120° C. or higher, more preferably 125° C. or higher and 150° C. or lower, and even more preferably 130° C. or higher and 140° C. or lower.
• the seal layer has excellent heat resistance, such as retort resistance, and self-supporting properties.
• the polypropylene resin is preferably 1% by weight or more and 95% by weight or less, and more preferably 5% by weight or more and 90% by weight or less, relative to 100% by weight of the mixture of polypropylene resin and polyethylene resin that constitutes the sealing layer. If the polypropylene resin is 1% by weight or more, it will have excellent slip properties and will be less likely to have variation in the heat seal strength achieved.
• the polyethylene resin in the sealing layer is mainly composed of linear low-density polyethylene.
• linear low density polyethylene for example, at least one ethylene homopolymer selected from the group consisting of high pressure low density polyethylene, medium density polyethylene and high density polyethylene can be used.
• random or block copolymers mainly made of ethylene and copolymerized with other monomers such as ⁇ -olefins such as propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, and octene-1, vinyl acetate, (meth)acrylic acid, and (meth)acrylic acid esters, or mixtures thereof can be used. These may be crystalline, low-crystalline, or non-crystalline.
• the polyethylene resin constituting the sealing layer has a melt flow rate of 0.1 g/10 min or more and 9 g/10 min or less, preferably 0.5 g/10 min or more and 8 g/10 min or less, and more preferably 1 g/10 min or more and 7 g/10 min or less.
• the polyethylene resin constituting the sealing layer has a melting point of 100°C or higher and 140°C or lower, preferably 10°C or higher and 135°C or lower, and more preferably 110°C or higher and 130°C or lower.
• the melting point of a polyethylene resin may show two or more melting endothermic peaks, and the peak with the highest melting temperature was determined as the main peak.
• the polyethylene resin constituting the sealing layer preferably contains 90% or more by weight of straight-chain linear polyethylene resin, more preferably 95% or more by weight, even more preferably 97% or more by weight, and even more preferably 99% or more by weight.
• the polypropylene resin is preferably 1% by weight or more and 95% by weight or less, and the polyethylene resin is preferably 5% by weight or more and 99% by weight or less, more preferably 20 to 90% by weight, based on 100% by weight of the mixture of polypropylene resin and polyethylene resin constituting the seal layer. If the polypropylene resin is less than 1% by weight, delamination with the laminate layer is likely to occur, and the burst strength and seal strength are likely to vary. If an intermediate layer is present between the laminate layer and the seal layer, delamination with the intermediate layer is likely to occur, and the burst strength and seal strength are likely to vary.
• the difference in melting point between the polypropylene-based resin and the polyethylene-based resin constituting the seal layer is preferably 15° C. or more, more preferably 16° C. or more, even more preferably 17° C. or more, even more preferably 18° C. or more, and particularly preferably 19° C. or more.
• the difference in melting point between the polypropylene-based resin and the polyethylene-based resin is 15° C. or more, the low-temperature bag-forming property is improved, the polypropylene-based resin and the polyethylene-based resin are well mixed, and the variation in burst strength and seal strength is reduced.
• the difference in melting point between the polypropylene-based resin and the polyethylene-based resin constituting the seal layer is preferably 50° C.
• the upper limit of the melting point difference is preferably 50° C. or less, more preferably 40° C. or less, even more preferably 30° C. or less, and most preferably 25° C. or less.
• the difference in melting point between the polypropylene-based resin and the polyethylene-based resin constituting the seal layer is 50° C. or less, phase separation or peeling is unlikely to occur in the seal layer, and variations in burst strength and seal strength are reduced.
• the arithmetic average melting point of the polypropylene resin and polyethylene resin constituting the seal layer is preferably 100°C or more, more preferably 112°C or more, even more preferably 116°C or more, even more preferably 116°C or more, and particularly preferably 121°C or more.
• the arithmetic average melting point of the polypropylene resin and polyethylene resin is 100°C or more, the heat resistance of the packaging material obtained by processing the laminated sealant film is improved.
• the boiling suitability is improved
• the semi-retort suitability is improved
• when it is 116°C or more the retort suitability is improved
• when it is 121°C or more the high retort suitability is improved.
• the resin composition of the seal layer preferably contains an antiblocking agent, and examples of the antiblocking agent include particles made of silica such as synthetic silica, inorganic particles such as diatomaceous earth, talc and mica, and organic particles such as silicone particles, acrylic particles, nylon particles and polyethylene particles. It is more preferable to contain silica particles or polyethylene particles. In particular, it is preferable to contain silica particles and polyethylene particles.
• the average particle size of the particles used in the present invention is preferably 2 ⁇ m or more, more preferably 3 ⁇ m or more, and even more preferably 5 ⁇ m or more, and is preferably 20 ⁇ m or less, more preferably 15 ⁇ m or less, and even more preferably 10 ⁇ m or less.
• the particle content in the resin composition in the sealing layer is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, and even more preferably 0.4% by weight or more, relative to the sealing layer of the film. Also, 2% by weight or less is preferable, more preferably 1.5% by weight or less, and even more preferably 1.0% by weight or less is preferable. If the amount of particles added is less than 0.1% by weight, it becomes difficult to achieve a surface roughness Ra of 0.1 ⁇ m or more on at least one surface layer, making it difficult to obtain anti-blocking properties and slip properties. Also, if the amount of particles added is more than 2% by weight, the number of surface protrusions increases, resulting in poor appearance and poor abrasion resistance.
• the resin composition in the seal layer preferably contains 0.01% by weight or more and 2.0% by weight or less of fatty acid amide as an organic lubricant, more preferably 0.05% by weight or more and 1.5% by weight or less, and particularly preferably 0.1% by weight or more and 1.0% by weight or less.
• fatty acid amide is 0.01% or more, blocking between films is small, and the handling of the film is easily satisfied.
• fatty acid amide is 2.0% by weight or less, the seal strength is not easily reduced.
• fatty acid amides include erucic acid amide, ethylene bis oleic acid amide, behenic acid amide, etc., and these may be used in combination.
• erucic acid amide has a low melting point, is easy to bleed, and is easy to impart lubricity.
• the sealing layer contains a combination of silica particles as an antiblocking agent and erucamide as an organic lubricant. More preferably, the sealing layer contains a combination of polyethylene particles as an antiblocking agent and erucamide as an organic lubricant. More preferably, the sealing layer contains silica particles and polyethylene particles as an antiblocking agent in combination with erucamide as an organic lubricant.
• the ratio of the melt flow rate of the polypropylene resin to the melt flow rate of the linear low density polyethylene resin in the seal layer is 0.8 or more, preferably 0.9 or more, more preferably 1.0 or more, even more preferably 1.1 or more, even more preferably 1.2 or more, and particularly preferably 1.4 or more.
• the ratio of the melt flow rate of the polypropylene resin to the melt flow rate of the linear low density polyethylene resin in the seal layer is 2.0 or less, preferably 1.8 or less, more preferably 1.7 or less, and particularly preferably 1.6 or less.
• the laminated sealant film is less likely to cause appearance defects such as misalignment, blemishes, and unevenness.
• the laminate layer in the present invention is made of a resin composition containing a polypropylene-based resin as a main component.
• the "main component” means that the proportion of polypropylene resin in the resin composition is 90 mass% or more, more preferably 95 weight% or more, even more preferably 97 weight% or more, and even more preferably 99 weight% or more.
• the polypropylene resin in the laminate layer is a resin containing propylene as a main component, and examples thereof include propylene homopolymers, random copolymers and block copolymers of propylene and ⁇ -olefins such as ethylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, and octene-1.
• random copolymers and/or block copolymers of propylene and ⁇ -olefins such as ethylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, and octene-1 are preferred.
• the term "main component" means that the proportion of propylene in the polypropylene resin is 90% by mass or more, more preferably 95% by weight or more, even more preferably 97% by weight or more, and even more preferably 99% by weight or more.
• the polypropylene resin constituting the laminate layer preferably has a melt flow rate (JIS K7112) of 0.1 g/10 min or more and 9 g/10 min or less, more preferably 0.5 g/10 min or more and 8 g/10 min or less, and even more preferably 1 g/10 min or more and 7 g/10 min or less.
• JIS K7112 melt flow rate
• the upper limit of the melting point (JIS K7121) of the polypropylene resin constituting the laminate layer is preferably 150° C., more preferably 145° C. or less, and even more preferably 140° C.
• the melting point (JIS K7121) of the polypropylene resin constituting the laminate layer is 150° C. or less, the tensile modulus of the laminate sealant film is easily set to 500 MPa or less.
• the lower limit of the melting point (JIS K7121) of the polypropylene resin constituting the laminate layer is preferably 120°C, more preferably 125°C, and even more preferably 130°C.
• the laminate sealant film is less likely to wrinkle when, for example, retorted, and transparency is easily maintained.
• a packaging bag made of the same material can be obtained, and the film can be used in applications that could not be handled by sealant films made of polyethylene resins. It is useful as a so-called mono-material film.
• the resin composition of the laminate layer may contain, for example, at least one ethylene homopolymer selected from the group consisting of high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene.
• ethylene homopolymer selected from the group consisting of high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene.
• random or block copolymers in which ethylene is the main component and other monomers such as propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, and octene-1 are copolymerized with vinyl acetate, (meth)acrylic acid, and (meth)acrylic acid esters, or mixtures thereof can be used.
• the content of these polymers other than polypropylene-based resins in the laminate layer is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less.
• the polyethylene resin constituting the laminate layer preferably has a melt flow rate (JIS K7112) of 0.1 g/10 min or more and 9 g/10 min or less, more preferably 0.5 g/10 min or more and 8 g/10 min or less, and even more preferably 1 g/10 min or more and 7 g/10 min or less.
• the polyethylene resin constituting the laminate layer preferably has a melting point (JIS K7121) of 100°C or more and 140°C or less, more preferably 105°C or more and 135°C or less, and even more preferably 110°C or more and 130°C or less.
• the melting point of a polyethylene resin may show two or more melting endothermic peaks, and the peak with the highest melting temperature was determined as the main peak.
• the resin composition of the laminate layer preferably contains an antiblocking agent, and examples of such agents include particles made of silica such as synthetic silica, inorganic particles such as diatomaceous earth, talc and mica, and organic particles such as silicone particles, acrylic particles, nylon particles and polyethylene particles. It is more preferable to contain silica particles or polyethylene particles. In particular, it is preferable to contain silica particles and polyethylene particles.
• the average particle size of the particles used in the present invention is preferably 2 ⁇ m or more, more preferably 3 ⁇ m or more, and even more preferably 5 ⁇ m or more, and is preferably 20 ⁇ m or less, more preferably 15 ⁇ m or less, and even more preferably 10 ⁇ m or less.
• the particle content in the resin composition in the laminate layer is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, and even more preferably 0.4% by weight or more, relative to the sealing layer of the film. Also, it is preferably 2% by weight or less, more preferably 1.5% by weight or less, and even more preferably 1.0% by weight or less. Also, if the amount of particles added is 2% by weight or less, there will not be too many protrusions on the surface, and poor appearance and abrasion resistance will be less likely to occur.
• the resin composition in the laminate layer preferably contains 0.01% by weight or more and 2.0% by weight or less of fatty acid amide as an organic lubricant, more preferably 0.05% by weight or more and 1.5% by weight or less, and particularly preferably 0.1% by weight or more and 1.0% by weight or less.
• fatty acid amide is 0.01% by weight or more, blocking between films is not too strong, and the handling of the film is easily satisfied.
• it is 2.0% by weight or less the seal strength is not easily reduced.
• the fatty acid amide include erucic acid amide, ethylene bis oleic acid amide, and behenic acid amide, and these may be used in combination.
• the ratio of the melt flow rates of the raw resins mixed in the seal layer is preferably 0.5 or more and 2.0 or less, more preferably 0.8 or more and 1.8 or less, and even more preferably 1.0 or more and 1.6 or less. If the melt flow rate ratio is within this range, it is less likely to cause appearance defects such as layer misalignment, spots, and unevenness.
• the laminate sealant film of the present invention may include an intermediate layer between the laminate layer and the seal layer.
• the intermediate layer in the present invention is made of a resin composition containing a polypropylene-based resin as a main component.
• main component means that the proportion of the polypropylene resin in the resin composition is 90% by mass or more, preferably 95% by weight or more, even more preferably 97% by weight or more, and even more preferably 99% by weight or more.
• the polypropylene-based resin in the intermediate layer is a resin containing propylene as a main component, and examples thereof include propylene homopolymers, random copolymers and block copolymers of propylene and an ⁇ -olefin such as ethylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, octene-1, etc.
• random copolymers of propylene and an ⁇ -olefin such as ethylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, octene-1, etc. are preferred.
• the term "main component" means that the proportion of propylene in the polypropylene resin is 90% by mass or more, preferably 95% by weight or more, even more preferably 97% by weight or more, and even more preferably 99% by weight or more.
• the polypropylene-based resin constituting the intermediate layer preferably has a melt flow rate of 0.1 g/10 min or more and 9 g/10 min or less, more preferably 0.5 g/10 min or more and 8 g/10 min or less, and even more preferably 1 g/10 min or more and 7 g/10 min or less.
• the upper limit of the melting point (JIS K7121) of the polypropylene resin constituting the intermediate layer is preferably 150° C., more preferably 145° C. or less, and even more preferably 140° C. When the melting point (JIS K7121) of the polypropylene resin constituting the laminate layer is 150° C. or less, the tensile modulus of the laminate sealant film is easily set to 500 MPa or less.
• the lower limit of the melting point (JIS K7121) of the polypropylene resin constituting the intermediate layer is preferably 120° C., more preferably 125° C., and even more preferably 130° C.
• the laminated sealant film is less likely to wrinkle when, for example, retorted, and transparency is easily maintained.
• the laminated sealant film can be laminated with an OPP (oriented polypropylene) film to form a mono-material film, and can be used in applications that could not be handled by a sealant film made of a polyethylene resin.
• the resin composition for the intermediate layer may be, for example, at least one ethylene homopolymer selected from the group consisting of high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene.
• ethylene is the main component and other monomers such as propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, and octene-1 are copolymerized with vinyl acetate, (meth)acrylic acid, and (meth)acrylic acid esters, or mixtures thereof can be used.
• the content of these polymers other than polypropylene-based resins in the laminate layer is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, and particularly preferably 5% by mass or less.
• the polyethylene resin constituting the intermediate layer preferably has a melt flow rate of 0.1 g/10 min or more and 9 g/10 min or less, more preferably 0.5 g/10 min or more and 8 g/10 min or less, and even more preferably 1 g/10 min or more and 7 g/10 min or less.
• the polyethylene resin constituting the intermediate layer preferably has a melting point of 100°C or more and 140°C or less, more preferably 105°C or more and 135°C or less, and even more preferably 110°C or more and 130°C or less.
• the melting point of a polyethylene resin may show two or more melting endothermic peaks, and the peak with the highest melting temperature was determined as the main peak.
• the resin composition of the intermediate layer may contain an antiblocking agent, and examples of such agents include particles made of silica such as synthetic silica, inorganic particles such as diatomaceous earth, talc and mica, and organic particles such as silicone particles, acrylic particles, nylon particles and polyethylene particles. It is more preferable to contain silica particles or polyethylene particles. It is particularly preferable to contain silica particles and polyethylene particles.
• the resin composition in the intermediate layer may contain inorganic particles such as synthetic silica, diatomaceous earth, talc, and mica, and organic particles such as silicone particles, acrylic particles, nylon particles, and polyethylene particles.
• the average particle size of the particles used in the present invention is preferably 2 ⁇ m or more, more preferably 3 ⁇ m or more, and even more preferably 5 ⁇ m or more.
• the average particle size is preferably 20 ⁇ m or less, more preferably 15 ⁇ m or less, and even more preferably 10 ⁇ m or less.
• the particle content in the resin composition in the intermediate layer is preferably 2% by weight or less, more preferably 1.5% by weight or less, and even more preferably 1.0% by weight or less, relative to the sealing layer of the film.
• the resin composition in the intermediate layer may contain a fatty acid amide, preferably at 2.0% by weight or less, more preferably at 1.5% by weight or less, particularly preferably at 1.0% by weight or less.
• a fatty acid amide include erucic acid amide, ethylene bis oleic acid amide, and behenic acid amide, and these may be used in combination.
• the ratio of the melt flow rates of the raw resins mixed in the sealing layer is preferably 0.5 to 2.0, more preferably 0.8 to 1.8, and even more preferably 1.0 to 1.6. If the melt flow rate ratio is within this range, it is less likely to cause appearance defects such as layer misalignment, spots, and unevenness.
• the layer structure of the laminated sealant film of the present invention may be laminate layer/seal layer, laminate layer/intermediate layer/seal layer, or laminate layer/intermediate layer 1/intermediate layer 2/seal layer. It is preferable to provide an intermediate layer between the laminate layer and the seal layer because peeling between the laminate layer and the seal layer is unlikely to occur and recycled raw materials can be easily used, and the raw material composition of the intermediate layer is preferably intermediate between the laminate layer and the seal layer in order to make peeling between the laminate layer and the seal layer unlikely to occur.
• the thickness of the laminate layer is preferably 3 ⁇ m or more, more preferably 5 ⁇ m or more.
• the thickness of the seal layer is preferably 3 ⁇ m or more, more preferably 5 ⁇ m or more.
• the thickness of the intermediate layer is preferably 3 ⁇ m or more, more preferably 5 ⁇ m or more, even more preferably 10 ⁇ m or more, particularly preferably 15 ⁇ m or more.
• the thickness of the laminate layer is preferably 12 ⁇ m or less, more preferably 10 ⁇ m or less, and even more preferably 8 ⁇ m or less.
• the thickness of the seal layer is preferably 12 ⁇ m or less, more preferably 10 ⁇ m or more, and even more preferably 8 ⁇ m or less.
• the thickness of the intermediate layer is preferably 30 ⁇ m or less, more preferably 25 ⁇ m or less, and even more preferably 20 ⁇ m or less.
• the ratio of the thickness of the intermediate layer to the thickness of the laminate layer is preferably 1.0 or more, more preferably 1.5 or more, and even more preferably 2.0 or more.
• the ratio of the thickness of the seal layer to the thickness of the laminate layer is preferably 0.3 to 1.5, more preferably 0.5 to 1.2.
• the ratio of the thickness of the intermediate layer to the thickness of the sealing layer is preferably 1.0 or greater, more preferably 1.5 or greater, and even more preferably 2.0 or greater.
• the ratio of the melt flow rates of the raw resins of adjacent layers is preferably 0.5 or more and 2.0 or less. When the melt flow rate ratio is within this range, poor appearance such as layer misalignment, blemishes, and unevenness is unlikely to occur.
• the main peak of the melting point of the laminated sealant film of the present invention is preferably 121° C. or higher, more preferably 130° C. or higher, and even more preferably 140° C. or higher. When the main peak of the melting point of the film is 121° C. or higher, the high retort suitability is further improved.
• the method for producing the laminated sealant film of the present invention will be described in detail below, but the present invention is not limited thereto.
• the resin compositions for the laminate layer, intermediate layer, and seal layer may be prepared by blending the above-mentioned resin raw materials and, if necessary, various additives in a mixer such as a Henschel mixer, a Banbury mixer, or a tumbler mixer, and then pelletizing the mixture into a film using a single-screw or twin-screw extruder. Alternatively, the components may be blended together and fed to a film-forming machine.
• the mixed resin composition is melted under conditions of, for example, a resin temperature of 110 to 300° C., melt-extruded into a sheet from, for example, a T-shaped die, cast onto a cooling roll, and cooled and solidified to obtain an unstretched sheet.
• a specific method for this is preferably casting onto a cooling roll.
• a multi-layering device such as a multi-layer feed block, a static mixer, a multi-manifold die, etc., can be used.
• there is a method in which resins discharged from different flow paths using two or more extruders are laminated into multiple layers using a multi-layer feed block or a multi-manifold die.
• Examples of the method include a method in which a melt-kneaded laminated resin composition sheet is melt-extruded and then formed into a film by a T-die method or an inflation method, and the T-die method is particularly preferred because it allows the melting temperature of the resin to be increased.
• the lower limit of the cooling roll temperature is preferably 10°C. If it is less than the above, not only may the crystallization suppression effect become saturated, but also problems such as condensation may occur, which is not preferable.
• the upper limit of the cooling roll temperature is preferably 70°C or less. If it exceeds the above, crystallization proceeds and transparency deteriorates, which is not preferable.
• the temperature of the cooling roll is in the above range, it is preferable to lower the humidity of the environment near the cooling roll to prevent condensation.
• the surface of the chill roll rises in temperature because the hot resin comes into contact with it.
• chill rolls are cooled by running cooling water through piping inside, but it is necessary to reduce the temperature difference across the width of the chill roll surface by ensuring a sufficient amount of cooling water, devising an appropriate piping layout, and performing maintenance to prevent sludge from adhering to the piping.
• the thickness of the unstretched sheet is preferably in the range of 3 ⁇ m to 200 ⁇ m, and the thickness of the film is preferably in the range of 5 ⁇ m to 100 ⁇ m, more preferably 10 ⁇ m to 80 ⁇ m.
• the resulting unstretched sheet may be stretched, but since stretching it more than twice will cause the tensile modulus to exceed 500 MPa, it is preferable to stretch it less than twice.
• the "longitudinal direction” is the direction corresponding to the flow direction in the film manufacturing process
• the "width direction” is the direction perpendicular to the flow direction in the film manufacturing process.
• the "longitudinal direction” may be abbreviated to the "MD direction”
• the "width direction” may be abbreviated to the "TD direction”.
• the upper limit of the tensile modulus in the longitudinal direction of the laminated sealant film of the present invention is preferably 500 MPa, more preferably 480 MPa, even more preferably 460 MPa, even more preferably 440 MPa, particularly preferably 420 MPa, and most preferably 400 MPa.
• the lower limit of the tensile modulus in the longitudinal direction of the laminated sealant film of the present invention is preferably 200 MPa, more preferably 250 MPa, even more preferably 300 MPa, and even more preferably 325 MPa.
• the upper limit of the tensile modulus in the width direction of the laminated sealant film of the present invention is preferably 550 MPa, more preferably 530 MPa, even more preferably 500 MPa, even more preferably 480 MPa, and particularly preferably 440 MPa.
• the lower limit of the tensile modulus in the width direction of the laminated sealant film of the present invention is preferably 200 MPa, more preferably 250 MPa, even more preferably 300 MPa, and even more preferably 325 MPa.
• the tensile modulus in the width direction is 200 MPa or more, bag-making processing is easier to carry out.
• the upper limit of the sum of the tensile modulus in the longitudinal direction and the tensile modulus in the transverse direction of the laminated sealant film of the present invention is preferably 1050 MPa, more preferably 1000 MPa, even more preferably 950 MPa, even more preferably 900 MPa, particularly preferably 850 MPa, and most preferably 800 MPa.
• the tensile modulus in the longitudinal direction is 1050 MPa or less, the low-temperature sealing effect at the sealing start temperature is improved.
• the lower limit of the sum of the tensile modulus in the longitudinal direction and the tensile modulus in the transverse direction of the laminated sealant film of the present invention is preferably 400 MPa, more preferably 500 MPa, even more preferably 600 MPa, and even more preferably 650 MPa.
• the sum of the tensile modulus in the longitudinal direction and the tensile modulus in the transverse direction is 400 MPa or more, bag making is easier to carry out.
• the upper limit of the average of the tensile modulus in the longitudinal direction and the tensile modulus in the transverse direction of the laminated sealant film of the present invention is preferably 500 MPa, more preferably 480 MPa, even more preferably 460 MPa, even more preferably 440 MPa, and particularly preferably 420 MPa.
• the average of the tensile modulus in the longitudinal direction and the tensile modulus in the transverse direction is 500 MPa or less, the low-temperature sealing effect at the sealing start temperature is improved.
• the lower limit of the average of the tensile modulus in the longitudinal direction and the tensile modulus in the transverse direction of the laminated sealant film of the present invention is preferably 200 MPa, more preferably 250 MPa, even more preferably 300 MPa, and even more preferably 325 MPa.
• the tensile modulus in the longitudinal direction is 200 MPa or more, bag-making processing is easier to carry out.
• the haze of the laminated sealant film of the present invention is preferably 10% or less, more preferably 9% or less, even more preferably 8% or less, even more preferably 7% or less, and particularly preferably 5% or less. If the haze exceeds 10%, the film often has streaks or scratches, and it becomes difficult to visually recognize the contents.
• the haze of the laminate sealant film of the present invention is preferably 1% or more, more preferably 2% or more, and even more preferably 3% or more. When the haze is 1% or more, the coefficient of friction is unlikely to increase.
• the laminated sealant film of the invention has better appearance unevenness, particularly when the melt flow rates of the raw resins of the resin composition constituting the seal layer are closer, and the more widely separated they are, the more likely uneven appearance will occur.
• the delamination of the laminated sealant film of the present invention means, for example, a case where delamination occurs between the seal layer and the intermediate layer when the flat seal initiation temperature, the hermetic seal initiation temperature, or the burst strength is measured. If this delamination occurs, it becomes difficult to remove the contents, so it is preferable that delamination does not occur. Delamination is likely to occur when the components or component ratios of the resin compositions of the seal layer and the intermediate layer and/or the intermediate layer and the laminate layer are significantly different.
• the flat seal initiation temperature of the laminated sealant film of the present invention is preferably 60°C or higher and 150°C or lower, more preferably 70°C or higher and 140°C or lower, and even more preferably 80°C or higher and 130°C or lower. It is preferable that the flat seal initiation temperature has a lower limit of a temperature that is 30°C or more lower than the lowest melting point of the polyethylene-based resin and/or polypropylene-based resin of the seal layer, and an upper limit of a temperature that is 10°C or more higher than the highest melting point of the polyethylene-based resin and/or polypropylene-based resin of the laminate layer.
• the low-temperature sealing effect of the flat seal initiation temperature is evaluated based on the degree of decrease in the flat seal initiation temperature, using the flat seal initiation temperature in Comparative Example 1 described later as a reference.
• the low-temperature sealability of the flat seal initiation temperature is preferably 5° C. or higher, more preferably 10° C. or higher, even more preferably 15° C. or higher, even more preferably 20° C. or higher, particularly preferably 25° C. or higher, and most preferably 27° C. or higher.
• the sealing initiation temperature of the laminated sealant film of the present invention is preferably 60°C or higher and 150°C or lower, more preferably 70°C or higher and 140°C or lower, and even more preferably 80°C or higher and 130°C or lower. It is preferable that the lower limit of the sealing initiation temperature is a temperature that is 30°C or more lower than the lowest melting point of the polyethylene-based resin and/or polypropylene-based resin of the seal layer, and the upper limit is a temperature that is 10°C or more higher than the highest melting point of the polyethylene-based resin and/or polypropylene-based resin of the laminate layer.
• the low-temperature sealing effect of the hermetic seal start temperature is evaluated based on the degree of decrease in the hermetic seal start temperature, using the hermetic seal start temperature in Comparative Example 1 described below as a reference.
• the low-temperature sealability of the hermetic seal start temperature is preferably above 10°C, more preferably 11°C or higher, even more preferably 12°C or higher, particularly preferably 15°C or higher, and most preferably 20°C or higher.
• the hot tack property of the laminated sealant film of the present invention is desirably such that the peel distance of the tack is 20 mm or less at a lower temperature.
• the hot tack property is said to be good when the seal strength between the sealant films is sufficient even when the resin of the sealant film is in a molten state.
• the low-temperature sealing effect of the hot tack property is evaluated based on the degree of reduction in the hot tack temperature, based on the hot tack temperature in Comparative Example 1 described later.
• the low-temperature sealing effect of the hot tack property is preferably 5° C. or higher, more preferably 10° C. or higher, even more preferably 15° C. or higher, even more preferably 18° C. or higher, and particularly preferably 20° C. or higher.
• the sealing properties of the present invention are such that, in order to achieve low-temperature sealing compared to conventional technology, the sealing layer contains an ethylene-based resin with a low melting point, and is a mixture with a polypropylene-based resin to prevent delamination between the sealing layer and the adjacent layer, while the laminate layer and intermediate layer are primarily composed of a propylene-based resin to maintain the heat resistance of the laminated sealant film.
• the impact strength of the laminated sealant film of the present invention is preferably less likely to decrease even at a low temperature of 5° C. or less than the impact strength at room temperature.
• the higher the mixing ratio of the polyethylene resin constituting the seal layer the less likely the impact strength at low temperatures is to decrease.
• the cold resistance improvement of the impact strength of the laminated sealant film of the present invention is evaluated by the difference from the impact strength at 5° C. in Comparative Example 1 described later as a standard.
• the cold resistance improvement of the impact strength is preferably 0.05 J or more, more preferably 0.10 J or more, even more preferably 0.15 J or more, even more preferably 0.20 J or more, and particularly preferably 0.25 J or more.
• the burst strength of the laminated sealant film of the present invention is evaluated using a bag made from the laminated sealant film.
• the burst strength is preferably 20 kPa or more, more preferably 30 kPa or more, and even more preferably 35 kPa or more. It has been confirmed that the laminated sealant film of the present invention achieves low-temperature sealing effects in terms of flat seal initiation temperature, hermetic seal initiation temperature, and hot tack temperature by optimizing the melting point of the seal layer and the elastic modulus of the film, and also improves its burst strength. This is thought to be due to the fact that the bag becomes easier to deform by optimizing the elastic modulus in particular, improving the burst strength.
• the static and dynamic friction coefficients between the sealing layer surfaces of the laminated sealant film of the present invention are preferably 2.0 or less, more preferably 1.0 or less, and even more preferably 0.5 or less, when a load of 0.5 kgf is applied. If the static and/or dynamic friction coefficients are 2.0 or more, the slipperiness between the films becomes insufficient, and the handling properties as a packaging material are not satisfactory.
• the melting point of the resin was measured in accordance with JIS K7121 using a differential scanning calorimeter (Seiko Instruments Inc., DSC60). Specifically, about 5 mg of the sample was packed in an aluminum pan, heated from room temperature to 200° C. at a rate of 10° C./min, held at 200° C. for 3 minutes, cooled to 23° C., held at 23° C. for 3 minutes, and then heated again to 200° C. The melting point was determined to be the maximum melting endothermic peak temperature. When there were two or more melting endothermic peaks, the highest melting endothermic peak was determined to be the melting point.
• Inorganic particles or polyethylene particles were dispersed in ion-exchanged water stirred at a predetermined rotation speed (about 5000 rpm) using a high-speed stirrer, and the dispersion was added to isotone (physiological saline) and further dispersed using an ultrasonic disperser, after which the particle size distribution was obtained by the Cole counter method and calculated as the volume average particle size.
• the refractive index was 1.30 for physiological saline, 1.457 for synthetic silica and diatomaceous earth, and 1.54 for polyethylene.
• the heat-sealed sample was cut into a strip with a heat seal width of 15 mm, and set in a universal material testing machine (Instron Japan Company Limited, 68TM-5 model), and the maximum strength at which the seal layers were peeled off at a speed of 200 mm/min was measured (n number: 3), and the heat seal strength and heat seal temperature at each temperature were plotted.
• the heat seal temperature at which the strength reached 4.9 N/15 mm was read from a graph connecting each plot with a straight line, and this was taken as the flat seal initiation temperature.
• a laminate of a laminated sealant film and a biaxially oriented polypropylene film (manufactured by Toyobo Co., Ltd., Pylen (registered trademark), P2161, 20 ⁇ m) was prepared as follows.
• a dry lamination adhesive (Toyo-Morton Co., Ltd., TM569, CAT-10L) was applied to the corona surface of the biaxially oriented polypropylene film so as to give a solid content of 3 g/ m2 , and after the solvent was volatilized and removed in an oven at 80°C, the corona surface of the laminated sealant film and the adhesive-coated surface were nipped and laminated with a temperature-controlled roll at 60°C. This laminated laminated sealant film was left to stand at 40°C for 2 days.
• This laminated laminate sealant film was made into a bag using a horizontal pillow packaging machine (FUJIKIKAI Co., Ltd., FW3301 II/B BD100). The conditions were set to a cut length of 250 mm, height of 45 mm, and rotation speed of 40 rpm, and a sponge scrubber (KIKURON Co., Ltd., KIKURON A (size: 75 x 115 x 36 mm)) was used as the content. The center seal part and the end seal part were kept at the same temperature, and the temperature was lowered from 160°C in 5°C intervals. For the evaluation, first, one bag was cut into two so that two complete end seal parts were obtained.
• the laminated sealant films were placed one on top of the other with the sealant surfaces facing each other, and heat sealed for 1 second at temperatures of 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, and 160°C under a pressure of 2 kg/cm2, and then a load of 46 g was applied to measure the distance the seal peeled off.
• the device used was a HEAT SEAL TESTER, TP-701-B, manufactured by Tester Sangyo Co., Ltd.
• the temperature at which the peel distance of the sealed portion was 20 mm or less was defined as the hot tack temperature.
• the measurement was carried out in accordance with JIS K7127 under the following conditions.
• the tensile modulus of the laminated sealant film in the machine direction (MD) and the direction perpendicular to the film machine direction (TD) was measured three times with a sample length of 100 mm, a sample width of 15 mm, a chuck distance of 20 mm, and a speed of 200 mm/min, and the average value of each measurement was recorded as the tensile modulus in each direction.
• the interlayer delamination of the laminated sealant film of the present invention means the case where delamination occurs between the seal layer and the intermediate layer and/or between the intermediate layer and the laminate layer when the flat seal initiation temperature, the hermetic seal initiation temperature or the burst strength is measured.
• the appearance unevenness of the laminated sealant film of the present invention was evaluated by visually checking the presence or absence of appearance defects called layer misalignment, spots, and unevenness, which are not uniform in appearance of the film.
• the impact strength was measured under the following conditions in accordance with ASTM D3420.
• the laminated sealant film was cut out so that an outer diameter of 100 mm was ensured, and the laminated sealant film was left standing at a measurement temperature of 23°C or 5°C for one day and night. Then, a test piece with a diameter of 80 mm was measured five times, and the average value was taken as the impact strength.
• the impact strength was measured using a film impact tester (Yasuda Seiki Seisakusho Co., Ltd.) placed at the same measurement temperature as the film.
• the laminated sealant film was measured in accordance with JIS K8701 using a turbidity meter (manufactured by Nippon Denshoku Industries Co., Ltd., model: ZE2000).
• the static friction coefficient and the dynamic friction coefficient were determined under the following conditions in an environment of 23° C. and 65% RH: the load was 0.5 kgf, and the tensile speed was 200 mm/min.
• the measurement surfaces of the laminated sealant film itself were the opposing seal layer surface and seal layer surface (B/B) or the seal layer surface and laminate layer surface (F/B).
• the laminated laminate sealant film was formed by opposing the sealing layer surfaces of the laminate sealant film (CP/CP) or by opposing the laminate layer surface of the laminate sealant film and the biaxially oriented polypropylene film (OP/CP).
• the apparatus used was TENSILON, Toyo Baldwin Co., Ltd., STM-T-50BP.
• butene polymer BL2491M (manufactured by Mitsui Chemicals, Inc., Toughmer (registered trademark), butene resin, melting point 100°C, melt flow rate 4.0g/10min, tensile modulus 260MPa)
• Ultra-high molecular weight polyethylene particle master batch Ultra-high molecular weight polyethylene particles (Mipelon PM200, average particle size 10 ⁇ m, manufactured by Mitsui Chemicals, Inc.) were mixed with Noblen (registered trademark) FL6745A manufactured by Sumitomo Chemical Co., Ltd. to prepare a master batch containing 10% by weight of ultra-high molecular weight polyethylene particles.
• Erucamide master batch Erucamide was mixed with Noblen (registered trademark) FL6745A manufactured by Sumitomo Chemical Co., Ltd. to prepare a master batch containing 5% by weight of erucamide.
• Behenic acid amide master batch Behenic acid amide was mixed with Noblen (registered trademark) FL6745A manufactured by Sumitomo Chemical Co., Ltd. to prepare a master batch containing 2% by weight of behenic acid amide.
• Examples 1 to 12 The laminate layer and the intermediate layer were made of FL6745A.
• the seal layer was made of the resins and additives shown in Tables 1 and 2, and the resins and additives were melted at 240°C in each of three extruders, filtered through a sintered filter with a filtering accuracy of 60 ⁇ m, and then co-extruded from a T-die into a sheet.
• the laminate layer, intermediate layer, and seal layer were melt-extruded so that the thickness ratio was 20:60:20 vol.%, cooled and solidified with a cooling roll at 30°C, and then wound up into a roll at a speed of 20 m/min to obtain a laminate sealant film with a total thickness of 30 ⁇ m (laminate layer thickness 6 ⁇ m, intermediate layer thickness 12 ⁇ m, seal layer thickness 6 ⁇ m) and a wet tension of the laminate layer of 45 mN/m.
• the content ratio of polypropylene-based resin and polyethylene-based resin in each layer is based on the total of polypropylene-based resin and polyethylene-based resin.
• the evaluation results are shown in Tables 1 and 2.
• Example 13 A laminated sealant film was obtained in the same manner as in Example 5, except that the laminate layer was made of FL8115A.
• the laminated sealant films obtained in Examples 1 to 13 had a high low-temperature sealing effect at the flat seal start temperature due to the low melting point of the seal layer, an excellent low-temperature sealing effect at the hermetic seal start temperature due to the low elastic modulus, and further showed excellent impact strength due to the inclusion of a polyethylene resin, and showed sufficiently low static and dynamic friction coefficients and good appearance due to the inclusion of a suitable antiblocking agent and organic lubricant. Of course, there was no problem with film formation processability, and sufficient burst strength was obtained.
• the film obtained in Comparative Example 1 was a single polypropylene resin film, and had poor low-temperature sealing effect with respect to the flat seal initiation temperature and the hermetic seal initiation temperature.
• the films obtained in Comparative Examples 2 to 7 are inferior in low-temperature sealing effect at the sealing initiation temperature.
• the film obtained in Comparative Example 8 was inferior in low-temperature sealing effect at the sealing initiation temperature, and delamination was observed between the sealing layer and the intermediate layer.
• the tensile modulus of the film is high, and the low-temperature sealing effect, particularly the sealing initiation temperature, is poor.
• Comparative Examples 9 to 16 A laminate sealant film was obtained in the same manner as in Example 1, except that a master batch was appropriately used for the laminate layer, intermediate layer and seal layer, so that the resin and additives shown in Table 4 were used as raw materials. The evaluation results are shown in Table 4.
• the film obtained in Comparative Example 9 was a single polypropylene resin film, and had poor low-temperature sealing effect in terms of the flat seal initiation temperature and the hermetic seal initiation temperature.
• the films obtained in Comparative Examples 10 to 15 are inferior in low-temperature sealing effect at the sealing initiation temperature. In the film obtained in Comparative Example 16, delamination was observed between the seal layer and the intermediate layer.
• Comparative Examples 17 to 22 A laminate sealant film was obtained in the same manner as in Example 1, except that a master batch was appropriately used for the laminate layer, intermediate layer and seal layer, so that the resin and additives shown in Table 5 were used as raw materials. The evaluation results are shown in Table 5.
• the films obtained in Comparative Examples 17 to 22 had a large melt flow rate ratio between the propylene-based copolymer and the ethylene-based polymer in the seal layer, and had uneven lamination and poor appearance.
• Comparative Example 23 A laminate sealant film was obtained in the same manner as in Example 1, except that a master batch was appropriately used for the laminate layer, intermediate layer and seal layer, so that the resin and additives shown in Table 5 were used as raw materials. The evaluation results are shown in Table 5.
• the film obtained in Comparative Example 23 had a high tensile modulus of elasticity and was poor in low-temperature sealing effect at the sealing initiation temperature.
• Comparative Example 24 A laminate sealant film was obtained in the same manner as in Example 1, except that a master batch was appropriately used for the laminate layer, intermediate layer and seal layer, so that the resin and additives shown in Table 5 were used as raw materials. The evaluation results are shown in Table 5.
• the film obtained in Comparative Example 24 is a polyethylene film, which has a low tensile modulus and is poor in handleability and self-supporting property as a packaging material.
• the film obtained in Comparative Example 24 has a low melting point of the film and the melting point of the sealing layer, and is prone to wrinkles and adhesion to each other during retort treatment.
• Comparative Example 25 A laminate sealant film was obtained in the same manner as in Example 1, except that a master batch was appropriately used for the laminate layer, intermediate layer and seal layer, so that the resin and additives shown in Table 5 were used as raw materials. The evaluation results are shown in Table 5.
• the film obtained in Comparative Example 25 was a film made of linear low-density polyethylene resin, and the melting points of the film and the sealing layer were low, so that wrinkles were likely to occur during retort treatment, and there was a risk of the films sticking to each other.
• Comparative Examples 26 and 27 A laminate sealant film was obtained in the same manner as in Example 1, except that a master batch was appropriately used for the laminate layer, intermediate layer and seal layer, so that the resin and additives shown in Table 5 were used as raw materials. The evaluation results are shown in Table 5.
• the films obtained in Comparative Examples 26 and 27 had a large ratio of the melt flow rate of the polypropylene resin to the melt flow rate of the linear low-density polyethylene resin in the seal layer, and were prone to causing misalignment of the layers of the laminated sealant film and poor appearance such as spots and unevenness.
• the laminated sealant film of the present invention has excellent low-temperature bag-forming properties and is therefore suitable as a packaging material for many products such as food, beverages, medicines, and chemicals.
• it can be suitably used as a material for automatically forming pillow packaging bags, gusset packaging bags, three-sided seal packaging bags, etc. while packaging the contents.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Laminated Bodies (AREA)
• Wrappers (AREA)
• Bag Frames (AREA)

Priority Applications (2)

Applications Claiming Priority (4)

Publications (1)

Family

ID=90737718

Family Applications (1)

Country Status (4)

Cited By (2)

Citations (7)

Family Cites Families (4)

• 2023
  • 2023-09-18 TW TW112135448A patent/TW202421437A/zh unknown
  • 2023-09-29 WO PCT/JP2023/035779 patent/WO2024084928A1/ja not_active Ceased
  • 2023-09-29 JP JP2024502706A patent/JPWO2024084928A1/ja active Pending
  • 2023-09-29 KR KR1020257010827A patent/KR20250092175A/ko active Pending

Patent Citations (7)

Also Published As

Similar Documents

Legal Events