TWI596166B - Laminated film and packaging materials - Google Patents

Description

Laminated film and packaging materials

The present invention relates to a laminated film which can have heat resistance or good package suitability even if an extended substrate having heat resistance is not attached.

In the past, from the viewpoint of protecting contents, packaging materials are required to have high heat seal strength, pinhole resistance, low temperature impact resistance, and the like. Moreover, from the viewpoint of automatic packaging by a packaging machine, it is preferable that the difference between the melting point of the sealing rod contacting the heat source and the sealing layer on the inner surface side sealed by thermal fusion is larger. Moreover, because the high-rigidity film with toughness can be easily and easily installed in the packaging machine, the operator is easy to operate, and from these viewpoints, heat resistance is generally used. Extensible base film such as biaxially oriented polypropylene (OPP), biaxially stretched polyester (OPET), and biaxially stretched polyamide (OPA), which are excellent in high rigidity, and non-stretched polyethylene excellent in sealing or adhesion ( A laminated film obtained by laminating a PE or a film of a non-stretched polypropylene (CPP) with an adhesive.

However, from the viewpoint of environmental protection in recent years, the volume of the packaging material to be used is reduced by the thinning of the packaging material, and the lamination method is used to reduce the lamination step, and the organic solvent or the adhesive itself used for the adhesive is reduced. The use of non-use, etc., is gradually gaining importance among users or end consumers.

In view of the above-mentioned requirements, the inventors of the present invention have proposed to use a high-melting-point polypropylene having heat resistance as a surface resin layer and a resin layer mainly composed of an olefin-based resin having a lower melting point than the polypropylene. Heat sealing layer and laminating, thereby being able to obtain without using an extended substrate A coextruded multilayer film which is excellent in suitability and excellent in pinhole resistance, and a packaging material comprising the film (for example, see Patent Document 1).

However, in response to the demand for cost reduction in the market, we are striving to increase production speed and look forward to further improving heat resistance.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-234660

The object of the present invention is to provide a laminated film which is excellent in surface heat resistance and which can be used in the form of a monomer which does not utilize an extended substrate, and which is manufactured in view of the above problems. A method of laminating a film, and providing a packaging material using the laminated film.

In addition, the object of the present invention is to provide a laminated film which is excellent in the suitability of the packaging machine and which has excellent adhesion strength between the heat-resistant coating layer and the olefin-based film.

In order to solve the above problems, the inventors of the present invention have found that by providing a heat-resistant coating composed of a cellulose acetate-based coating agent on a resin substrate having a heat-sealable thermoplastic resin layer, the surface heat resistance can be effectively improved. The ability to achieve the desired heat sealability is achieved by the completion of the present invention.

That is, the present invention provides a laminated film having a heat-resistant coating on a resin substrate and a packaging material using the laminated film; the laminated film is characterized by a heat-resistant layer of the resin substrate The surface layer of the different surface is composed of a heat-sealable thermoplastic resin layer; the heat-resistant coating layer is a layer composed of a cellulose acetate-based coating agent.

The heat-resistant thermoplastic laminated film of the present invention can have extremely high heat resistance by a simple structure by having a heat-resistant coating layer composed of a cellulose acetate-based coating agent, so that even a thinned structure can The heat sealing at a high heat sealing temperature greatly expands the temperature range of the sealable, and thus contributes greatly to an increase in production efficiency or a reduction in manufacturing cost. Further, it is easily obtained by applying a heat-resistant coating agent to a resin substrate having a heat-sealable thermoplastic resin layer. The design of the multilayer film can be easily changed depending on the desired performance (transparency, rigidity, workability, etc.) or use (packaging materials, posters, labels, etc.), and the versatility is excellent.

The present invention relates to a laminated film having a heat-resistant coating on a resin substrate; and a surface layer having a heat-resistant layer on the surface of the resin substrate is made of a heat-sealable thermoplastic resin layer; A layer composed of a cellulose acetate coating agent.

[Resin substrate]

The resin substrate used in the present invention is a resin substrate composed of a heat-sealable thermoplastic resin layer (hereinafter referred to as a heat-sealable thermoplastic resin layer (A1)). In the laminated film of the present invention, the surface composed of the heat-sealable thermoplastic resin layer is a surface layer on one surface, and the surface on the other surface is a surface composed of a heat-resistant coating layer.

The heat-sealable thermoplastic resin layer (A1) used in the present invention is a layer containing a heat-sealable thermoplastic resin (hereinafter referred to as a heat-sealable thermoplastic resin (a1)) as a main component. As the heat-sealable thermoplastic resin, a heat-sealable thermoplastic resin used for a packaging material or the like can be used, and a polyolefin-based resin, a polyester-based resin, or a polystyrene-based resin can be preferably used. Among them, in particular, a polyolefin-based resin can be preferably used from the viewpoint of low cost and easy availability of desired heat sealability.

The polyolefin-based resin which can be used here may, for example, be a homopolymer or a copolymer of an α-olefin having 2 to 6 carbon atoms. The copolymerized form may be a block copolymer or a random copolymer. In addition, as the polyolefin resin, from the viewpoint of maintaining the appearance at the time of secondary molding and suppressing the warpage of the film itself, it is preferred to use a melting point of 100 ° C or higher.

As the polyolefin-based resin, for example, any of known ones such as a polypropylene-based resin, a polyethylene-based resin, and a cyclic olefin-based resin can be used. For example, examples of the polypropylene-based resin include a propylene homopolymer, a propylene-ethylene copolymer, a propylene-butene-1 copolymer, a propylene-ethylene-butene-1 copolymer, and an ethylene-propylene block copolymer. , metal aromatic catalyst is polypropylene. These may be used alone or in combination of two or more. When the obtained heat-resistant olefin-based multilayer film is wound into a roll shape and stored for a long period of time, a crystalline propylene-based resin is preferably used from the viewpoint of avoiding adhesion. Further, in the present case, the crystallinity means a peak having a peak of 0.5 J/g or more in the range of 95 to 250 ° C in DSC (differential scanning calorimetry).

Further, the polypropylene resin is preferably a melt flow rate (hereinafter referred to as "MFR at 230 ° C"; and a value measured at 230 ° C and 21.18 N in accordance with JIS K7210: 1999) is 0.5 to 30.0 g/10 In minutes, the melting point is 120 to 165 ° C, more preferably 230 ° C MFR is 2.0 ~ 15.0 g / 10 minutes, the melting point of 125 ~ 162 ° C. When the MFR and the melting point are in this range, the film shrinks less when the secondary molding such as heat molding is performed after the multilayering, so that the appearance can be maintained without causing warpage of the medium itself, and also as a total Film formation properties when extruding a multilayer film. Further, the density is preferably from 0.890 to 0.910 g/cm ³ , more preferably from 0.895 to 0.905 g/cm ³ .

In addition, when a propylene-ethylene block copolymer is used as the heat-sealable thermoplastic resin (a1), the surface is modified into a satin shape, and wrinkles when the multilayer film is wound into a roll shape can be suppressed. The production, in turn, can reduce the adhesion when stored in a roll shape. Here, the propylene-ethylene block copolymer-based propylene and ethylene block-polymerized resin may, for example, be a polymerization of ethylene in the presence of a propylene homopolymer or a propylene obtained by polymerizing ethylene and propylene. Ethylene block copolymer and the like.

Moreover, when a mixed resin of a crystalline propylene resin and an ethylene-propylene rubber (hereinafter referred to as "EPR") is used, the surface of the layer (A1) can be easily changed into a satin shape. As the crystal used at this time The propylene-based resin is preferably a versatile propylene homopolymer. On the other hand, as the EPR used at this time, from the viewpoint of forming irregularities on the surface of the film and modifying the surface into a satin shape, it is preferable that the weight average molecular weight is in the range of 400,000 to 1,000,000. It is in the range of 50 to 800,000. Further, from the viewpoint that the surface of the film can be homogeneously modified into a satin shape, the content of EPR in the mixed resin is preferably in the range of 5 to 35% by mass. The MFR (230 ° C) of the mixed resin of the crystalline propylene polymer and EPR is preferably in the range of 0.5 to 15 g/10 min from the viewpoint of easy extrusion processing. Further, the weight average molecular weight of the EPR is determined by calculation of a component obtained by cross-fractionation at 40 ° C using o-dichlorobenzene as a solvent by GPC (gel permeation chromatography). Further, the content ratio of EPR in the mixed resin was determined by extracting the amount of EPR extracted by cross-fractionation at 40 ° C using o-dichlorobenzene as a solvent.

The method for producing the mixed resin of the crystalline propylene-based resin and the EPR is not particularly limited, and specific examples thereof include a Ziegler-type catalyst by using a propylene homopolymer and an ethylene-propylene rubber, respectively. After the solution polymerization method, the slurry polymerization method, the gas phase polymerization method, or the like, the two are mixed by a mixer, or the two-stage polymerization method is used to form a propylene homopolymer in the first stage, and then in the second stage. A method of producing EPR in the presence of the polymer in the section, and the like.

The above-mentioned Ziegler-type catalyst, that is, the Ziegler-Natta catalyst, may be, for example, a transition metal compound containing a titanium compound or the like, or a carrier supported by a magnesium compound or the like. A carrier-supporting catalyst obtained by a transition metal compound is combined with a promoter of an organometallic compound such as an organoaluminum compound.

The polyethylene-based resin is preferably a vinyl-based resin having a density of 0.900 g/cm ³ or more and less than 0.970 g/cm ³ . Specific examples of the resin include ultra low-density polyethylene. (VLDPE), linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE) and other polyethylene Resin, or ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene - an ethylene-based copolymer of ethylene acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), etc.; An ionic polymer of an acrylic copolymer, an ionic polymer of an ethylene-methacrylic acid copolymer, or the like. Among these, from the viewpoint of good pinhole resistance, LDPE, LLDPE, LMDPE, and MDPE are preferable.

The density of the ethylene-based resin as described above is preferably 0.900 g/cm ³ or more, less than 0.970 g/cm ³ , more preferably 0.905 g/cm ³ or more, and less than 0.965 g/cm ³ . As long as the density is satisfied, two or more kinds of polyethylene resins may be blended. The density is less than 0.900 g/cm ³ , and the rigidity is lowered and the packaging mechanical properties are deteriorated. On the other hand, when it is 0.970 g/cm ³ or more, the pinhole resistance is deteriorated. When the density is in this range, it has moderate rigidity, and is excellent in mechanical strength such as pinhole resistance, and film formability and extrusion suitability are improved. Further, the melting point is preferably in the range of 95 to 130 ° C, more preferably 100 to 125 ° C. When the melting point is in this range, when the heat-resistant coating is applied or heated during secondary molding, since the shrinkage of the film is small, the appearance of the film can be maintained and the warpage of the film itself can be suppressed. Moreover, when this multilayer film is used as a packaging bag, the adhesiveness in the case where the layer (A1) is heat-sealed inside is also excellent. These may be used alone or in combination of two or more.

Examples of the cyclic polyolefin-based resin include a norbornene-based polymer, a vinyl alicyclic hydrocarbon-based polymer, and a cyclic conjugated diene polymer. Among these, a decene-based polymer is particularly preferable. In addition, examples of the norbornene-based polymer include a ring-opening polymer of a norbornene-based monomer (hereinafter referred to as "COP"), and a homopolymer of a norbornene-based monomer and an olefin such as ethylene. A decene-based copolymer (hereinafter referred to as "COC") or the like. Furthermore, hydrides of COP and COC are particularly desirable. Further, the weight average molecular weight of the cyclic olefin resin is preferably 5,000 to 500,000, more preferably 7,000 to 300,000.

The norbornene-based monomer which is a raw material of the above-described norbornene-based polymer is an alicyclic monomer having a norbornene ring. Examples of such a decene-based monomer include norbornene, tetracyclododecene, ethylene norbornene, vinyl norbornene, and ethylene tetracyclododecene. Ethylidene tetracyclododecene), dicyclopentadiene, dimethano tetrahydrofluorene, phenyl norbornene, methoxycarbonyl norbornene, methoxycarbonyl tetracyclododecene, and the like. These decene-based monomers may be used singly or in combination of two or more.

The norbornene-based copolymer is obtained by copolymerizing a norbornene-based monomer with an olefin copolymerizable with a norbornene-based monomer. Examples of such an olefin include olefins having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene; and cyclic olefins such as cyclobutene, cyclopentene, and cyclohexene; A non-conjugated diene such as hexadiene. These olefins may be used alone or in combination of two or more.

As a commercially available product of the cyclic polyolefin-based resin (a), a ring-opening polymer (COP) which is a norbornene-based monomer, for example, "ZEONOR" manufactured by Zeon Co., Ltd., may be mentioned. (ZEONOR), etc., as the decene-based copolymer (COC), for example, "Apel" manufactured by Mitsui Chemicals Co., Ltd., "TOPAS (TOPAS)" manufactured by Polyplastics Co., Ltd., and the like.

From the viewpoint of further improving the processing stability or the workability when co-extruding with other resin layers, the MFR (190 ° C, 21.18 N) of the polyethylene resin is preferably 2 to 20 g/10 min. Good for 3~10g/10 minutes.

The heat-sealable thermoplastic resin (a1) which is the heat-sealable thermoplastic resin layer (A1) used in the present invention is preferably used alone or in combination with a polyester resin or a polyester resin or a polystyrene resin. It can also be used in combination with most resins. In the heat-sealable thermoplastic resin used for the heat-sealable thermoplastic resin layer (A1), it is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more. Good is 90% by mass or more.

In the case where the obtained film is used as a package, the heat-sealable thermoplastic resin layer (A1) is described in JP-A-2006-213065: containing 1-butene and propylene as necessary A 1-butene-based copolymer composed of a component and a heat-sealing layer of a copolymer obtained by using propylene and ethylene as essential components can be used as an easy-opening bag.

In the heat-sealable thermoplastic resin layer (A1), components other than the heat-sealable thermoplastic resin (a1) may be added as needed within the range not impairing the object of the present invention: other resin components, and prevention A component such as an aerosol, an antistatic agent, a heat stabilizer, a nucleating agent, an antioxidant, a lubricant, an anti-blocking agent (ANTIBLOCKING AGENT), a release agent, a UV absorber, a colorant, and the like. In particular, in order to impart processing suitability at the time of film formation or packaging suitability in the case of a packaging material, the friction coefficient of the surface is 1.5 or less, and particularly preferably 1.0 or less. Therefore, it is desirable to appropriately add a lubricant or an anti-blocking agent. , antistatic agent. In the case of containing an additive such as the above-mentioned lubricating material or an antistatic agent, it is preferably 10 parts by mass or less, more preferably 0.1% by mass based on 100 parts by mass of the resin component contained in the heat-sealable thermoplastic resin layer (A1). 5 parts by mass.

The heat-sealable thermoplastic resin layer (A1) may be a single layer or a multilayer structure having two or more layers. From the viewpoint of further improvement in rigidity, heat resistance, and transparency, a film having a single layer or a multilayer structure mainly composed of a polypropylene resin is preferable.

The resin substrate used in the present invention may have a structure in which the heat-sealable thermoplastic resin layer (A1) is provided on the surface layer, and may be a resin substrate obtained only from the heat-sealable thermoplastic resin layer (A1). A resin substrate obtained by laminating a heat-sealable thermoplastic resin layer (A1) and others may be used. When the resin substrate is formed only of the heat-sealable thermoplastic resin layer (A1), it is possible to reduce the volume of the packaging material by reducing the thickness of the obtained laminated film, or to greatly reduce the manufacturing cost. Contribution is therefore ideal. Further, in order to enhance various effects, a resin substrate obtained by laminating another layer can be preferably used.

As the other layer laminated on the heat-sealable thermoplastic resin layer, for example, an anchor coating layer for improving the adhesion of the heat-resistant coating layer can be preferably exemplified. The tackifying coating layer is not particularly limited as long as it can improve the adhesion of the heat-resistant coating layer, and a tackifying coating layer composed of various tackifying agents or resin films can be used.

In particular, it is preferable to provide a layer containing an acid-modified olefin-based resin as a tackifying coating layer on the surface of the resin substrate provided with a heat-resistant coating layer (hereinafter referred to as a layer containing an acid-modified olefin-based resin (A2). )). The layer containing the acid-modified olefin-based resin is particularly excellent in the coatability of the cellulose acetate-based coating agent or the heat-resistant coating layer composed of the coating agent, and particularly preferably suppresses secondary processing. The impact (friction, heating, etc.) causes peeling and the like.

The olefin component which is a main component of the acid-modified polyolefin resin (hereinafter referred to as the acid-modified olefin resin (a2)) used for the layer (A2) containing the acid-modified olefin resin is not particularly limited, but is preferably A mixture of carbon atoms of 2 to 6 such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene or 1-hexene may be used. Among them, an olefin having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene or 1-butene is more preferable, and ethylene or propylene is more preferable, and ethylene is most preferable. Further, the acid-modified polyolefin resin (a2) is required to contain a (meth) acrylate component. Examples of the (meth) acrylate component include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (methyl). Hexyl acrylate, octyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, (meth) acrylate Octadecyl ester and the like. From the viewpoint of ease of availability and adhesion, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl acrylate, and more preferably methyl acrylate are preferred. , ethyl acrylate. Further, the (meth) acrylate component may be copolymerized with the olefin component, and is not limited thereto. Examples of the state of copolymerization include random copolymerization, block copolymerization, and graft copolymerization. Branch modified) and so on. (Further, "(meth)acrylic acid ~" means "acrylic acid ~ or methacrylic acid ~"). Specifically, for example, as an ethylene-(meth)acrylate copolymer, there are Elvaloy (trade name: manufactured by Du Pont-Mitsui Polychemicals Co., Ltd.), Acryft (trade name: manufactured by Sumitomo Chemical Co., Ltd.), and the like. . These may be used alone or in combination of two or more.

Further, the acid-modified polyolefin resin (a2) may be an acid-modified one using an unsaturated carboxylic acid component. Examples of the unsaturated carboxylic acid component include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, and crotonic acid, and unsaturated dicarboxylic acid. Acidic half esters, hemi-amines, and the like. Among them, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferred, and acrylic acid and maleic anhydride are particularly preferred. Further, the unsaturated carboxylic acid component may be copolymerized with the olefin component, and is not limited thereto. Examples of the state of the copolymerization include random copolymerization, block copolymerization, and graft copolymerization (graft modification). Quality). Specifically, for example, as the ethylene-acrylic acid copolymer, NUCREL (trade name: manufactured by Du Pont-Mitsui Polychemicals Co., Ltd.) or the like can be mentioned. The ethylene-(meth)acrylate-maleic anhydride copolymer may, for example, be BONDINE (trade name: manufactured by Tokyo Materials Co., Ltd.). These may be used alone or in combination of two or more.

The acid modification ratio of the acid-modified olefin-based resin (a2) is suppressed from the adhesion to the cellulose acetate-based coating agent described later, and the adhesion of the wound multilayer film is suppressed and suppressed. It is preferable to use 3 to 40%, more preferably 7 to 35%, and most preferably 10 from the viewpoint of excellent balance of appearance defects such as wrinkles of the film in the drying step after application of the coating agent. ~30%.

The layer (A2) containing the acid-modified polyolefin resin may be used in combination with the other resin in addition to the acid-modified olefin-based resin (a2). In particular, from the viewpoint of being mixed with the acid-modified olefin-based resin (a2) and being easily coextruded with the heat-sealable thermoplastic resin layer (A1), it is preferred to use a polyolefin-based resin in combination.

The content of the acid-modified polyolefin resin (a2) in the layer (A2) containing the acid-modified polyolefin resin is preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass. the above.

As the polyolefin-based resin, any of the heat-sealable thermoplastic resins (a1) used in the layer (A1) can be preferably used. At this time, the thermoplastic resin used for the layer (A1) and the layer (A2) may be the same or different. Further, the polyolefin-based resin used as the layer (A2) may be a single one or a mixture of a plurality of types of users.

In the layer (A2), a polyolefin-based resin other than the acid-modified polyolefin resin (a2) is preferably used in combination. As the polyolefin-based resin, a polyolefin-based resin exemplified as the resin (a1) used in the layer (A1) can be preferably used. The content of the polyolefin resin other than the resin (a2) in the resin component contained in the layer (A2) is preferably less than 90% by mass, more preferably less than 80% by mass.

In addition to the polyolefin-based resin other than the acid-modified polyolefin resin (a2) and the acid-modified polyolefin resin (a2), the resin component used in the layer (A2) may contain any other resin, but The content of the other resin component other than the polyolefin resin is preferably less than 30% by mass in the resin component.

In the layer (A2) containing the acid-modified polyolefin resin, an antifogging agent, an antistatic agent, a heat stabilizer, a nucleating agent, an antioxidant, a lubricant, and the like may be added as long as the object of the present invention is not impaired. An anti-blocking agent, a release agent, a UV absorber, a colorant, and the like. Especially, in order to impart a film The processing suitability at the time of molding or the packaging suitability in the case of a packaging material, the friction coefficient of the surface is 1.5 or less, and particularly preferably 1.0 or less. Therefore, it is preferably in a resin layer corresponding to the surface layer of the multilayer film. Add lubricant or anti-blocking agent or antistatic agent. In the case of containing an additive such as the above-mentioned lubricating material or an antistatic agent, it is preferably 10 parts by mass or less, more preferably 100 parts by mass or less, based on 100 parts by mass of the resin component contained in the layer (A2) containing the acid-modified polyolefin resin. It is 0.1 to 5 parts by mass.

The thickness of the resin substrate used in the present invention can be appropriately set depending on the use of the film. For example, it is 20 to 70 μm in the case of a packaging material (bag or cover), and 70 to 70 in the case of a label or a poster. A range of 1000 μm.

As the resin substrate, the resin substrate in which the heat-sealable thermoplastic resin layer (A1) and the layer (A2) containing the acid-modified polyolefin resin are laminated, in particular, only the layer (A1) and the layer (A2) are used. In the case of the resin substrate to be formed, the ratio of the thickness of the layer (A2) to the total thickness of the layers (A1) and (A2) is preferably 5~ from the viewpoint of particularly easily ensuring adhesion to the heat-resistant coating layer. The range of 50% is preferably in the range of 2 to 40 μm as the thickness of the layer (A2).

As a method of laminating the heat-sealable thermoplastic resin layer (A1) and the layer (A2) containing an acid-modified polyolefin resin, it is preferred to laminate the layer (A1) adjacent to the layer (A2). Extrusion lamination molding. By using the co-extrusion method, the steps of coating or lamination can be omitted, and the effect of reducing the environmental load or reducing the time or cost of manufacturing is also practical, and the utility is extremely high.

As a co-extrusion method, for example, a layer (A1) and a layer are melted in a melted state by various coextrusion methods such as a co-extrusion multilayer molding method using a two-stage extrusion machine and a feed module method. (A2) After lamination, inflation, T mode. A method of processing a long roll film by a method such as a chill roll method is particularly preferable, and a co-extrusion method using a T die is most preferable.

The surface layer obtained by the present invention having a surface layer different from the surface having the heat-resistant layer, which is a layer composed of a heat-sealable thermoplastic resin layer, may be a non-stretched film or a stretched film.

The extension may also be a uniaxial extension extending only in the longitudinal direction (MD direction) or the lateral direction (TD direction), or may be a biaxial extension of bidirectional extension. In the stretching step, when a film having a surface layer composed of a heat-sealable thermoplastic resin layer is formed, a heat-resistant coating or the like is applied after stretching, or a resin substrate is used. The surface of the heat-resistant layer is a laminated film in which the surface layer of the different surface is a layer composed of a heat-sealable thermoplastic resin layer, and then stretched.

When the multilayer sheet is extended in the longitudinal direction (MD direction), the stretching ratio is preferably 2 to 10 times. If it is less than 2 times, the mechanical strength or moisture resistance effect by the extension is insufficient, and more than 10 times. The reduction in the tear strength of the obtained stretched film is not preferable.

When extending in the transverse direction (TD direction), the stretching ratio is preferably 2 to 20 times. If it is less than 2 times, the mechanical strength or moisture resistance of the stretching is insufficient. If it exceeds 20 times, the stretching film has a local thickness. Deviation, etc., is not ideal.

The extension temperature affects the characteristics of each resin, so the extension temperature is not limited, but the extension temperature is 60 to 180 ° C, more preferably 80 to 160 ° C. After the extension is completed, it is preferred to perform heat fixation. The heat setting can be carried out by a known method at preferably 80 to 170 ° C, more preferably 100 to 160 ° C.

Further, in the production of the multilayer film, the surface of the layer (A2) containing the acid-modified polyolefin resin may be subjected to surface treatment continuously using a corona discharge or a plasma discharge under heating or a passive gas atmosphere. .

The resin base material used for the laminated film of the present invention may suitably use a layer other than the above layer (A1) or (A2) for the purpose of use. For example, when it is used as a covering material, it can be made into a multi-layer structure as described in the Unexamined-Japanese-Patent No. 2004-75181 or the Unexamined-Japanese-Patent No. 2008-80543. In addition, when the cyclic polyolefin resin described in JP-A-2010-234660 is used as one layer in a multilayer structure, it can be made into a film having easy tearability, and it is preferable to use various types depending on the application. Multi-layer structure.

The resin substrate used in the laminated film of the present invention, especially on the side of the heat-resistant coating provided on the resin substrate The surface may be provided with a decorative layer such as a character, a figure, or a mark by printing or the like. The decorative layer may be provided on a part of the surface of the resin substrate, or may be provided in a comprehensive manner, or a plurality of decorative layers may be laminated. As a method of providing the decorative layer, the printing method is preferred because it is simple, and examples of the printing method include a screen printing method, a screen printing method, a gravure printing method, and a flexographic printing coating method. Thermal transfer printing method, etc.

As the ink used in the screen printing method or the screen printing method, various inks which can be used for printing of a film can be used, and a solvent-based or UV-curing system can be used. In particular, the solvent-based ink is preferably used to dry the solvent in a drying furnace, and it is preferably used without requiring a device such as a UV irradiation device to perform printing at low cost. As the ink used in the thermal transfer method, a resin type or a wax type can be used. Among them, the resin type is excellent in weather resistance, and therefore it is preferably used.

[heat resistant coating]

The heat-resistant coating layer (hereinafter referred to as heat-resistant coating layer (B)) used in the present invention is a heat-resistant coating layer composed of a cellulose acetate-based coating agent (hereinafter referred to as a cellulose acetate-based coating agent (b)). The heat-resistant coating layer (B) imparts extremely high heat resistance to the heat-sealable laminate film. Further, with the heat-resistant coating (B) used in the present invention, it is desirable to improve wear resistance or pinhole resistance.

The thickness of the heat-resistant coating layer (B) maintains a practical level of heat resistance or transparency, and maintains good production efficiency, preferably in the range of 0.2 μm to 50 μm, in consideration of sticking to the sealing rod, and The coating film strength of the heat-resistant coating layer (B) is more preferably in the range of 0.5 μm to 30 μm.

The cellulose acetate coating agent (b) used for the heat resistant coating layer (B) is a coating agent containing at least cellulose acetate, a crosslinking agent, and an organic solvent, and the cellulose acetate coating agent (b) is coated. After the resin substrate is placed on the resin substrate, the organic solvent contained in the cellulose acetate coating agent (b) is volatilized, whereby a heat resistant coating layer can be formed.

The cellulose acetate-based coating agent (b) is not particularly limited and may be appropriately selected depending on the drying speed or heat resistance of the coating. In particular, in the present invention, from the viewpoint of forming a coating layer on the aforementioned resin substrate, there is a need to provide a coating having high heat resistance, transparency, and packaging mechanical properties. Want.

The cellulose acetate used in the cellulose acetate-based coating agent (b) which can be easily imparted with such a performance is a semi-synthetic polymer obtained by acetate-forming a cellulose which is a natural polymer. Cellulose is a polymer having dehydrated glucose as a repeating unit, and each repeating unit has three hydroxyl groups, and cellulose acetate resins having different properties can be obtained depending on the degree of esterification (degree of substitution). The degree of substitution is expressed by the index of the so-called degree of acetylation. The degree of acetylation of the three hydroxy groups, that is, triacetyl cellulose, was 62.5%. The degree of acetylation of the cellulose acetate used in the present invention is preferably 40 to 70%, more preferably 43 to 62%. Further, as the average degree of polymerization, it is preferably from about 100 to about 400.

The content of the cellulose acetate in the cellulose acetate-based coating agent (b) is preferably 5% by mass or more, more preferably 10% by mass or more, based on the solid content of the organic solvent.

The cellulose acetate-based coating agent (b) may further contain a crosslinking agent such as an isocyanate compound reactive with the unsubstituted hydroxy group in order to further increase heat resistance, adhesion, and surface hardness.

As the polyisocyanate (b-1) used in the production of the cellulose acetate-based coating agent (b) used in the present invention, various types can be used. For example, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,12-dodecyl diisocyanate, cyclohexane- can be used. 1,3 or 1,4-diisocyanate, 1-isocyanate-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (alias isophorone diisocyanate; IPDI), Cyclohexylmethane-4,4'-diisocyanate (alias hydrogenated MDI), 2- or 4-isocyanate cyclohexyl-2'-isocyanate cyclohexylmethane, 1,3- or 1,4-bis-(isocyanate methyl) - cyclohexane, bis-(4-isocyanate-3-methylcyclohexyl)methane, 1,3- or 1,4-α,α,α',α'-tetramethylxylene diisocyanate, 2, 4- or 2,6-diisocyanate toluene, 2,2'-, 2,4'- or 4,4'-diisocyanate diphenylmethane (MDI), 1,5-naphthalene diisocyanate, p- or - Phenyl diisocyanate, xylene diisocyanate or diphenyl-4,4'-diisocyanate, and the like.

In the case where the mechanical strength or the like is particularly considered, it is preferable to use an aromatic diisocyanate, and in particular, in consideration of durability or light resistance, etc., it is preferred to use an aliphatic or alicyclic group. Isocyanate compound. Moreover, it is easy to obtain the ideal adhesion to the printed layer. In particular, when an aromatic diisocyanate is used and a cellulose acetate-based coating agent (b) is applied onto a printing layer, it is particularly preferable to use an MDI-based polyisocyanate.

Further, in order to further improve the heat resistance of the heat-resistant coating layer (B) obtained from the cellulose acetate-based coating agent (b), an amine resin, an epoxy compound, an aziridine compound, or a carbon dioxide may be used without any problem. Imine compound, A crosslinking agent such as an oxazoline compound. Among them, in particular, the point of rapid reactivity is preferably an amine resin or an isocyanate compound represented by a melamine crosslinking agent. Further, two or more kinds of crosslinking agents may be used in combination, or an appropriate amount of a curing accelerator may be used in combination.

The amount of the crosslinking agent to be added is preferably 1 to 20 parts by mass, more preferably 3 to 10 parts by mass, per 100 parts by mass of the solid content of the cellulose acetate coating agent (b). In this range, the adhesion resistance, heat resistance, moist heat resistance, and solvent resistance of the formed coating layer (B) can be improved without impeding the application of printing or the like on the coating layer (B). In particular, when an isocyanate-based crosslinking agent is used as the crosslinking agent, the isocyanate-based crosslinking agent is preferably a coating agent (b) based on 100 parts by mass of the solid content of the cellulose acetate-based coating agent (b). The solid content is used in an amount of 5 parts by mass or more.

When the organic solvent used in the production of the cellulose acetate-based coating agent (b) is used, it is preferable to use an organic solvent having a boiling point of 150 ° C or less in consideration of removing the residual solvent contained in the coating layer.

The organic solvent having a boiling point of 150 ° C or less may, for example, be MEK (methyl ethyl ketone), benzene, toluene, ethyl acetate, acetone, methyl ethyl ketone, diethyl ether, tetrahydrofuran, methyl acetate, acetonitrile. , chloroform, dichloromethane, etc. These may be used singly or in combination. Among them, acetone, methyl ethyl ketone, toluene, and ethyl acetate are particularly preferable as the highly soluble solvent of the cellulose acetate-based coating agent (b).

The cellulose acetate-based coating agent (b) may contain cellulose acetate and may also contain nitrocellulose, a vinyl chloride-vinyl acetate copolymer, a vinyl chloride-vinyl acetate-vinyl alcohol copolymer, An organic polymer such as a urethane resin, a fluorine resin, an acrylic resin, an epoxy resin, or a polybutyral resin. Furthermore, it is also possible to add anthrone oil, fluorine oil, and high fat as needed. Various lubricant components such as acid, paraffin wax, and fatty acid esters.

Further, the cellulose acetate-based coating agent (b) may contain a synthetic rubber resin such as an acrylic resin, a polyester resin or SBR, insofar as it does not impair transparency and heat resistance. The solid content ratio of the resins in the coating agent is preferably 30% or less, particularly preferably 10% or less.

Further, in the cellulose acetate-based coating agent (b), inorganic fine particles (colloidal cerium oxide) for improving the blocking resistance or the sliding resistance may be blended as needed to improve the moisture permeability. An antistatic agent and other additives.

Further, the cellulose acetate coating agent (b) preferably has a minimum film forming temperature of 50 ° C or lower, and more preferably 30 ° C or lower. In this range, coating can be performed without forming pinholes which are likely to occur at the time of film formation.

[Laminated film]

The laminated film of the present invention comprises a heat-resistant coating (B) comprising the cellulose acetate-based coating agent (b) on a resin substrate having the heat-sealable thermoplastic resin layer (A1). In the structure, the surface of one surface of the laminated film is the surface of the heat-resistant coating layer (B), and the surface of the other surface is the surface of the heat-sealable thermoplastic resin layer (A1). The laminated film of the present invention can achieve extremely high heat resistance by the simple structure without impairing the packaging mechanical suitability, so that the adhesion of the surface layer to the sealing rod does not occur during heat sealing at a high temperature, and it is desirable to suppress Deterioration of the appearance of the seal rod due to dirt or wrinkles of the seal portion. Therefore, in the thinned structure, heat sealing can be appropriately performed at a high heat sealing temperature, which can greatly contribute to reduction in manufacturing cost, and can also be used in the form of a monomer that does not utilize the extended substrate.

The thickness of the laminated film of the present invention may be appropriately adjusted depending on the intended use, and when it is used in various packaging materials or the like, it is preferable that the thickness is 15 to 150 μm, and the heat sealability or workability is good.

The laminated film of the present invention can be applied to the resin substrate by drying the cellulose acetate coating agent (b) to an arbitrary resin concentration, and then dried, and hardening such as heat hardening is required. Processed for manufacturing. The method of applying the cellulose acetate-based coating agent (b) to the resin substrate is not particularly limited, and for example, an air knife coater, a blade coater, and a roll coater are used. The method of a coater such as a cloth coater, a gravure coater, a comma coater, or a gate roll coater is simple.

The method of volatilizing the medium contained in the coating agent after applying the cellulose acetate coating agent (b) to the film is not particularly limited, and for example, a method of drying by a dryer is generally used. The drying temperature may be a temperature in which the medium is volatilized and does not adversely affect the substrate.

In the production of the multilayer film, the surface to which the heat-resistant coating is applied may be continuously subjected to surface treatment using a corona discharge or a plasma discharge or the like under heating or a passive gas atmosphere.

According to the heat-resistant thermoplastic laminated film of the present invention, a multilayer film having substantially no elongation can be obtained by the above-described production method, so that deep drawing by vacuum forming, foil stamping, and pressing can be performed. Secondary forming such as flower processing.

The laminated film of the present invention may be provided with a decorative layer of characters, figures, marks, or the like by printing or the like on the heat-resistant coating layer (B). The method of providing the decorative layer is preferable because the printing method is simple, and examples of the printing method include a screen printing method, a screen printing method, a gravure printing method, a thermal transfer printing method, and the like. .

When the heat-resistant coating layer (B) is subjected to printing or the like, in order to improve the adhesion to the printing ink, etc., it is preferable to apply a surface treatment to the resin substrate layer. Examples of such surface treatment include surface oxidation treatment such as corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, ozone treatment, ultraviolet treatment, or surface unevenness treatment such as sand blasting, and preferably corona treatment. deal with.

The laminated film of the present invention has desirable heat sealability and high heat resistance, and thus is ideally applied to various packaging materials. Examples of the packaging material include a packaging bag, a container, and a lid material for use in foods, pharmaceuticals, industrial parts, miscellaneous goods, magazines, and the like. Especially ideally It is used in medicines or industrial parts that are filled, packaged, and sealed at high speed, or foods or snacks that are stored at room temperature, chilled, frozen, etc.

The packaging material is preferably a heat sealable layer of the heat-sealable thermoplastic resin layer (A1) of the laminated film of the present invention, and the layers (A1) are superposed on each other to be heat-sealed, or the layer (A1) and the heat-resistant coating layer ( B) It is preferable to form a packaging bag by superposing heat sealing, whereby the layer (A1) is formed inside. For example, the two sheets of the multilayer film are cut out of the size of the desired packaging bag, and the three sides are heat-sealed and formed into a bag shape, and then the contents are filled from one side without heat sealing, and then sealed by heat sealing. This can be used as a packaging bag. Further, the roll-shaped film can be made into a cylindrical shape by an automatic packaging machine, and the end portion can be sealed, and then the package can be formed by sealing the upper and lower sides.

Moreover, the package can be formed by heat-sealing the heat-sealable thermoplastic resin layer (A1) with other heat-sealable films, sheets, and containers. container. The lid of the container. In this case, a film or sheet using a thermoplastic resin such as a polyethylene resin, a polypropylene resin, or a polyester resin can be used as the other film to be used.

The packaging material using the heat-resistant olefin-based multilayer film of the present invention can form a V groove, an I groove, a perforation, and a microporous in the sealing portion in order to reduce the initial tear strength and improve the opening property. Wait for the tear start.

Further, in the laminated film of the present invention, the pressure-sensitive adhesive layer may be provided on the heat-sealable thermoplastic resin layer (A1), and the laminated film or the other resin film of the present invention may be laminated and heat-sealed to be resealed. Sex bag.

The type of the adhesive is not particularly limited, and examples thereof include a natural rubber type, a synthetic rubber type, an acrylic type, a urethane type, a vinyl ether type, a polyoxymethylene type, a guanamine type, and a styrene type adhesive. A styrene-based elastomer, an olefin-based elastomer, or the like. In the above-mentioned adhesive layer, it is necessary to incorporate a suitable adhesion-imparting agent for the purpose of controlling adhesion characteristics, etc., for example, α-pinene or beta-pinene polymer, diterpene Ene polymer, α-pinene (pinene). An oxime resin such as a phenolic copolymer, an aliphatic or aromatic system, or an aliphatic group. Hydrocarbon resin such as aromatic copolymer, other pine A scented resin or a coumarone indene resin, an (alkyl) phenol resin or a xylene resin. In particular, when the layer (A1) and the layer (A2) to be described later are laminated by a co-extrusion method, the adhesive layer layer is coextruded on the layer (A1) opposite to the layer (A2). The method is preferred over the manufacturing cycle.

[Examples]

The present invention will be specifically described below by way of examples and comparative examples, but the present invention is not limited thereto. In addition, the parts and % in the examples are based on the quality unless otherwise specified.

[Preparation Example 1 of Cellulose Cellulose Coating Agent (b-1)]

250 parts of acetone and 600 parts of toluene were placed in a container equipped with a stirrer, and then 100 parts of cellulose acetate (L-20 manufactured by Daicel Co., Ltd.; 55% acetylation degree, 5% viscosity 50 mPa.s) was simultaneously placed. Stir to completely dissolve. Here, 25 parts of TDI-based polyisocyanate (Hardener No. 50 manufactured by DIC Co., Ltd.; 50% nonvolatile matter) was placed and completely dissolved to prepare a cellulose acetate coating agent (b-1) (not Volatile content 11.5%).

[Preparation Example 2 of cellulose acetate coating agent (b-2)]

300 parts of acetone and 600 parts of toluene were placed in a container equipped with a stirrer, and then 100 parts of cellulose acetate (L-20 manufactured by Daicel Co., Ltd.; 55% acetylation degree, 5% viscosity 50 mPa.s) was placed. Stir to completely dissolve. Here, 35 parts of MDI polyisocyanate (Hardener No. 10 manufactured by DIC Co., Ltd.; 60% nonvolatile matter) was placed and completely dissolved to prepare a cellulose acetate coating agent (b-2) (No Volatile content 11.5%).

[Preparation Example 3 of Cellulose Cellulose Coating Agent (b-3)]

300 parts of acetone, 600 parts of toluene, and 300 parts of N-methyl-2-pyrrolidone were placed in a container equipped with a stirrer, and then cellulose acetate (L-70 manufactured by Daicel Co., Ltd.; 60% degree of acetylation) was placed. 6% viscosity 50 mPa.s) 100 parts and stirred to completely dissolve. Here, 35 parts of MDI polyisocyanate (Hardener No. 10 manufactured by DIC Co., Ltd.; 60% nonvolatile matter) was placed and completely dissolved to prepare a cellulose acetate coating agent (b-2) (No Volatile content 11.5%).

(Example 1)

A propylene-ethylene copolymer [MFR: 8 g/10 min (230 ° C, 21.18 N), melting point: 138 ° C; hereinafter referred to as "COPP") was used as the resin for the resin layer (A1). Further, a vinyl-(meth)acrylic acid methyl ester copolymer [density: 0.940 g/cm ³ , MA content 18%; hereinafter referred to as "MA1") was used as the resin for the resin layer (A2). These resins are respectively supplied to an extruder (caliber 50 mm) for the resin layer (A1) and an extruder (caliber 50 mm) for the resin layer (A2), and melted at 200 to 250 ° C, and then melted. The resin is separately supplied to a co-extruded multilayer film manufacturing apparatus (feed module and T-die temperature: 250 ° C) having a T-die ‧ chill roll method with a feed module to perform co-melt extrusion to obtain a layer structure of the film In the two-layer structure of (A1)/(A2), the thickness of each layer was 45 μm/5 μm (total 50 μm) of the coextruded multilayer film. The surface of the (A2) layer of the support was subjected to a corona discharge treatment to have a wetting tension of 40 mN/m, and then the cellulose acetate coating obtained in Preparation Example 1 was applied so that the film thickness after drying became 2 μm. The agent (b-1) was prepared into the heat-resistant olefin-based laminated film of Example 1.

(Example 2)

The cellulose acetate-based coating agent (b-1) of Example 1 was replaced with the cellulose acetate-based coating agent (b-2) obtained in Preparation Example 2, and was produced in the same manner as in Example 1. A heat resistant olefin-based laminated film.

(Example 3)

The acid-modified olefin-based resin of the resin layer (A2) of Example 1 was replaced with an ethylene-acrylic acid methyl copolymer [MA content 12%, density: 0.933 g/cm ³ ; hereinafter referred to as "MA2"], A heat-resistant olefin-based laminated film was produced in the same manner as in Example 1 except that the cellulose acetate-based coating agent (b-1) was applied so that the film thickness after drying was 0.5 μm.

(Example 4)

The acid-modified olefin-based resin of the resin layer (A2) of Example 1 was replaced with an ethylene-methyl methacrylate copolymer [density: 1.00 g/cm ³ , copolymer content: 15%; A heat-resistant olefin-based laminated film was produced in the same manner as in Example 1 except for MA3".

(Example 5)

In addition to replacing the resin MA1 for the resin layer (A2) of Example 2 with the resin MA1 50% and the propylene-ethylene copolymer [density: 0.900 g/cm ³ , MFR: 7 to 9 g/10 min (230 ° C, 21.18 N) In the same manner as in Example 2, a heat-resistant olefin-based laminated film was produced in the same manner as in Example 2 except that the melting point was 150 ° C and the blend described below as "COPP" was 50%.

(Example 6)

A heat-resistant olefin-based laminated film was produced in the same manner as in Example 1 except that the resin MA1 for the resin layer (A2) of Example 2 was replaced with a blend of resin MA 120% and COPP 80%.

(Example 7)

The COPP of the resin layer (A1) of Example 5 was replaced with a high-density polyethylene [density: 0.93 g/cm ³ , MFR: 5 g/10 min (190 ° C, 21.18 N), melting point 120 ° C; A heat resistant olefin-based laminated film was produced in the same manner as in Example 5 except for MDPE.

(Example 8)

In addition to replacing the COPP of the resin layer (A1) of Example 5 with a linear low-density polyethylene [density: 0.905 g/cm ³ , MFR: 5.0 g/10 min (190 ° C, 21.18 N), melting point 100 ° C; In the following, the thickness of each layer of the layer structure (A1)/(A2) of the film is 25 μm/5 μm (total 30 μm), and the thickness of the film after drying is 5 μm. A heat-resistant olefin-based laminated film was produced in the same manner as in Example 5 except that the cellulose-based coating agent (b-1) was used.

(Example 9)

Except that the acrylic modified resin of Example 1 was replaced with an ethylene-(meth)acrylic acid copolymer [density: 0.940 g/cm ³ , acid modification rate 12%; hereinafter referred to as "MA4"), and Example 2 In the same manner, a heat-resistant olefin-based laminated film was produced.

(Embodiment 10)

The thickness of each layer of the layer structure (A1)/(A2) of the film of Example 1 was set to 114 μm/6 μm (total 120 μm), and acetic acid was applied so that the film thickness after drying became 2 μm. A heat-resistant olefin-based laminated film was produced in the same manner as in Example 1 except that the cellulose-based coating agent (b-1) was used.

(Example 11)

The thickness of each layer of the layer structure (A1)/(A2) of the film of Example 1 was set to 90 μm/30 μm (total 120 μm), and the cellulose acetate coating was applied so that the film thickness after drying became 2 μm. A heat-resistant olefin-based laminated film was produced in the same manner as in Example 1 except for the cloth (b-1).

(Embodiment 12)

An olefin-based single-layer film composed of the resin layer (A1) was produced in the same manner as in Example 1 except that the resin layer (A2) of Example 1 was not extruded. One side of the support was subjected to a corona discharge treatment so that the wetting tension became 40 mN/m, and then the cellulose acetate-based coating agent obtained in Preparation Example 3 was applied so that the film thickness after drying became 2 μm. -3) The heat resistant olefin-based laminated film of Example 12 was produced.

(Comparative Example 1)

An olefin-based laminated film was produced in the same manner as in Example 1 except that the cellulose acetate-based coating agent (b-1) was not applied.

The following evaluations were performed on the films obtained in the above Examples 1 to 12 and Comparative Example 1. The results obtained are shown in the table below.

[Evaluation of coatability of cellulose acetate coating agent]

The coating agent was applied to a film of A4 size by a bar coater so as to be 1.5 g/m ² to visually measure the number of pits.

○: No pits.

╳: There are more than one pit.

[Evaluation of heat resistance of film]

The appearance of the film when it was dried at 80 ° C for 2 minutes after application of the coating agent was visually evaluated.

○: There were almost no appearance defects such as bending, wrinkles, and deformation of the film.

△: Some defects such as bending, wrinkles, and deformation of the film were observed.

╳: Apparent defects such as obvious bends, wrinkles, and deformation of the film are observed.

[Evaluation of adhesion of coating]

A cellophane tape (manufactured by Nichiban) peeling test was carried out, and the evaluation was carried out visually.

○: Peeling without coating.

╳: Peeling of the coating.

[Packaging Machinery Adaptability]

The film prepared in the examples and the comparative examples was subjected to the following vertical pillow type packaging by an automatic packaging machine to form a bag, and the following evaluation was carried out.

Packaging machine: Rationalized Technology Research Co., Ltd. UniPacker NUV472

Horizontal seal: speed 30 bags / minute, vertical heat sealing temperature 150 ° C, barometer pressure 4kg / cm ² , the horizontal heat sealing temperature from 140 ° C to 200 ° C every 10 ° C change while sealing the resin layer (B) . It is made into a flat bag with a length of 200mm × a width of 150mm.

(shrinkage-wrinkle test)

The sealing portion of the flat bag which was subjected to the horizontal (closed palm) sealing and the longitudinal sealing was observed by the appearance, and the state of shrinkage, film adhesion to the heat sealing bar, and wrinkles were evaluated.

○: shrinkage without sealing parts, adhesion to sealing rods, wrinkles, etc.

△: There are some shrinkage of the sealing part, adhesion to the sealing rod, wrinkles, etc.

╳: shrinkage of the sealing part, adhesion to the sealing rod, wrinkles, etc.

(horizontal adhesion)

After the film which was bag-formed under the above conditions was naturally cooled at 23 ° C, a test piece of a strip shape of 15 mm width was cut out. The test piece was used in an oven at 23 ° C, 50% RH in an extension tester (A&D) Co., Ltd.), 90° peeling was performed at a speed of 300 mm/min, and the heat seal strength was measured. From the value of the obtained heat seal strength, the heat sealability was evaluated in accordance with the following criteria.

○: The heat seal strength is 300g/15mm or more

╳: The heat seal strength is less than 300g/15mm wide, or the film melts. Shrinkage is too large to measure

(Example 13)

A propylene-ethylene copolymer [MFR: 8 g/10 min (230 ° C, 21.18 N), melting point: 138 ° C; hereinafter referred to as "COPP") was used as the resin for the resin layer (A1). Further, a vinyl-(meth)acrylic acid methyl ester copolymer [density: 0.940 g/cm ³ , MA content 18%; hereinafter referred to as "MA1") was used as the resin for the resin layer (A2). These resins are respectively supplied to an extruder (caliber 50 mm) for the resin layer (A1) and an extruder (caliber 50 mm) for the resin layer (A2), and melted at 200 to 250 ° C, and then melted. The resin is separately supplied to a co-extruded multilayer film manufacturing apparatus (feed module and T-die temperature: 250 ° C) of a T-die ‧ chill roll method with a feed module to perform co-melt extrusion to obtain a layer structure of the film In the two-layer structure of (A1)/(A2), the thickness of each layer was 45 μm/5 μm (total 50 μm) of the coextruded multilayer film. The surface of the (A2) layer of the support was subjected to a corona discharge treatment to have a wetting tension of 40 mN/m, and then the cellulose acetate coating obtained in Preparation Example 1 was applied so that the film thickness after drying became 1 μm. The agent (b-1) is dried to form a coating. After drying, the nitrocellulose was printed on the coating in such a manner that the film thickness became 1 μm. The amine ester-based ink (c-1) (ULTIMA NT507 primary color blue manufactured by Di-Aisheng Co., Ltd.) was prepared into a heat-resistant olefin-based laminated film of Example 13.

(Example 14)

In addition to the nitrocellulose in Example 13. The urethane ink (c-1) is replaced by nitrocellulose. A heat-resistant olefin-based laminated film was produced in the same manner as in Example 13 except that the polyamine-based ink (c-2) (Grossa 507 primary color blue manufactured by Di Aisin Co., Ltd.) was used.

(Example 15)

In addition to the nitrocellulose in Example 13. The amine ester ink (c-1) was replaced with an amine ester ink (c-3) (Yunibia NT R507 primary color blue K-1 manufactured by Di Ai Sheng Co., Ltd.), and heat resistance was carried out in the same manner as in Example 13. An olefin-based laminated film.

(Embodiment 16)

Except that the cellulose acetate-based coating agent (b-2) obtained in Preparation Example 2 of the cellulose acetate-based coating agent (b-1) of Example 13 was used, the same procedure as in Example 13 was carried out. A heat resistant olefin-based laminated film was produced.

(Example 17)

In addition to the nitrocellulose in Example 16. The amine ester ink (c-1) is replaced by nitrocellulose. A heat-resistant olefin-based laminated film was produced in the same manner as in Example 16 except that the polyamine-based ink (c-2) (Grossa 507 primary color blue manufactured by Di Aisin Co., Ltd.) was used.

(Embodiment 18)

In addition to the nitrocellulose in Example 16. The amine ester ink (c-1) was replaced with an amine ester ink (c-3) (Yunibia NT R507 primary color blue K-1 manufactured by Di Ai Sheng Co., Ltd.), and heat resistance was carried out in the same manner as in Example 16. An olefin-based laminated film.

(Embodiment 19)

In the same manner as in Example 13, except that the cellulose acetate-based coating agent (b-1) of Example 13 was replaced with the cellulose acetate-based coating agent (b-3) obtained in Preparation Example 3, A heat resistant olefin-based laminated film.

(Embodiment 20)

In addition to the nitrocellulose in Example 19. The amine ester ink (c-1) is replaced by nitrocellulose. A heat-resistant olefin-based laminated film was produced in the same manner as in Example 19 except that the polyamine-based ink (c-2) (Grossa 507 primary color blue manufactured by Di Aisin Co., Ltd.) was used.

(Example 21)

In addition to the nitrocellulose in Example 19. The amine ester ink (c-1) was replaced with an amine ester ink (c-3) (Yunibia NT R507 primary color blue K-1 manufactured by Di Ai Sheng Co., Ltd.), and heat resistance was carried out in the same manner as in Example 19. An olefin-based laminated film.

The following evaluations were carried out for the films obtained in the above Examples 13 to 21. The results obtained are shown in the table below.

[Applicability evaluation of printing ink]

On the coating, an ink was applied to the A4-size film by a bar coater so as to be 1.5 g/m ² to visually measure the number of pits of the ink.

○: No pits.

╳: There are more than one pit.

[Evaluation of heat resistance of film]

The appearance of the film when the printed film was dried at 80 ° C for 2 minutes was visually evaluated.

○: There were almost no appearance defects such as bending, wrinkles, and deformation of the film.

△: Some defects such as bending, wrinkles, and deformation of the film were observed.

╳: Apparent defects such as obvious bends, wrinkles, and deformation of the film are observed.

(Example 22)

A propylene-ethylene copolymer [MFR: 8 g/10 min (230 ° C, 21.18 N), melting point: 138 ° C; hereinafter referred to as "COPP") was used as the resin for the resin layer (A1). Further, a vinyl-(meth)acrylic acid methyl ester copolymer [density: 0.940 g/cm ³ , MA content 18%; hereinafter referred to as "MA1") was used as the resin for the resin layer (A2). These resins are respectively supplied to an extruder (caliber 50 mm) for the resin layer (A1) and an extruder (caliber 50 mm) for the resin layer (A2), and melted at 200 to 250 ° C, and then melted. The resin is separately supplied to a co-extruded multilayer film manufacturing apparatus (feed module and T-die temperature: 250 ° C) of a T-die ‧ chill roll method with a feed module to perform co-melt extrusion to obtain a layer structure of the film In the two-layer structure of (A1)/(A2), the thickness of each layer was 45 μm/5 μm (total 50 μm) of the coextruded multilayer film. The surface of the (A2) layer of the support was subjected to corona discharge treatment so that the wetting tension became 40 mN/m, and the nitrocellulose was printed so that the film thickness after drying became 1 μm. Amine ester ink (c-1) (ULTIMA NT507 primary color blue manufactured by Di Ai Sheng Color Co., Ltd.). The cellulose acetate-based coating agent (b-1) obtained in Preparation Example 1 was applied to the obtained printing surface so that the film thickness after drying became 1 μm, and then dried to prepare the heat-resistant olefin of Example 22. A laminated film.

(Example 23)

In addition to the nitrocellulose in Example 22. The amine ester ink (c-1) is replaced by nitrocellulose. Polyamide ink (c-2) (Grossa 507 primary color blue manufactured by Di Ai Sheng Color Co., Ltd.) and Example 22 In the same manner, a heat-resistant olefin-based laminated film was produced.

(Example 24)

In addition to the nitrocellulose in Example 22. The amine ester ink (c-1) was replaced with an amine ester ink (c-3) (Yunibia NT R507 primary color blue K-1 manufactured by Di Ai Sheng Co., Ltd.), and heat resistance was carried out in the same manner as in Example 22. An olefin-based laminated film.

(Embodiment 25)

The heat treatment was carried out in the same manner as in Example 22 except that the cellulose acetate coating agent (b-1) of Example 22 was replaced with the cellulose acetate coating agent (b-2) obtained in Preparation Example 2. A olefin-based laminated film.

(Example 26)

In addition to the nitrocellulose in Example 25. The amine ester ink (c-1) is replaced by nitrocellulose. A heat-resistant olefin-based laminated film was produced in the same manner as in Example 25 except that the polyamine-based ink (c-2) (Grossa 507 primary color blue manufactured by Di Aisin Co., Ltd.) was used.

(Example 27)

In addition to the nitrocellulose in Example 25. The amine ester ink (c-1) was replaced with an amine ester ink (c-3) (Yunibia NT R507 primary color blue K-1 manufactured by Di Ai Sheng Co., Ltd.), and heat resistance was carried out in the same manner as in Example 25. An olefin-based laminated film.

(Embodiment 28)

The heat treatment was carried out in the same manner as in Example 22 except that the cellulose acetate coating agent (b-1) of Example 22 was replaced with the cellulose acetate coating agent (b-3) obtained in Preparation Example 3. A olefin-based laminated film.

(Example 29)

In addition to the nitrocellulose in Example 28. The amine ester ink (c-1) is replaced by nitrocellulose. Polyamide ink (c-2) (Grossa 507 primary color blue manufactured by Di Ai Sheng Color Co., Ltd.) and Example 28 In the same manner, a heat-resistant olefin-based laminated film was produced.

(Embodiment 30)

In addition to the nitrocellulose in Example 28. The amine ester ink (c-1) was replaced with an amine ester ink (c-3) (Yunibia NT R507 primary color blue K-1 manufactured by Di Ai Sheng Co., Ltd.), and heat resistance was carried out in the same manner as in Example 28. An olefin-based laminated film.

The following evaluations were carried out for the films obtained in the above Examples 22 to 30. The results obtained are shown in the table below.

[Evaluation of coatability of cellulose acetate coating agent]

The coating agent was applied to the A4 size film on a printing surface by a bar coater so as to be 1.5 g/m ² to visually measure the number of pits.

○: No pits.

╳: There are more than one pit.

[Evaluation of heat resistance of film]

After the application of the coating agent, the evaluation was visually performed on the appearance of the film when dried at 80 ° C for 2 minutes.

○: There were almost no appearance defects such as bending, wrinkles, and deformation of the film.

△: Some defects such as bending, wrinkles, and deformation of the film were observed.

╳: Apparent defects such as obvious bends, wrinkles, and deformation of the film are observed.

From the above-mentioned table, the laminated film of the present invention of Examples 1 to 12 is excellent in surface heat resistance and has an excellent packaging mechanical suitability. On the other hand, the laminated film of Comparative Example 1 which does not have a heat-resistant coating layer has low heat resistance, and the packaging mechanical property at a heat sealing temperature of a high temperature is inferior. Further, as shown in Examples 13 to 21, the laminated film of the present invention can be printed on various types of inks on a heat-resistant coating layer, and has an excellent printability. Further, as shown in Examples 22 to 30, when a resin film having a surface of a printing layer is used, a laminated coating layer is also preferable, and in particular, a laminate of Examples 23 to 24, 26 to 27, and 28 to 29 is used. The film is particularly excellent for the adhesion of the coating.

Claims (11)

A laminated film comprising a heat-resistant coating layer on a resin substrate, wherein a surface layer different from a surface of the resin substrate having a heat-resistant layer is composed of a heat-sealable thermoplastic resin layer. The heat resistant coating layer is a layer composed of a cellulose acetate coating agent; the cellulose acetate coating agent contains cellulose acetate, a crosslinking agent, and an organic solvent, and the cellulose acetate has a degree of acetylation of 40~ 70%. The laminated film of claim 1, wherein the organic solvent is an organic solvent having a boiling point of 150 ° C or less. The laminated film of claim 1 or 2, wherein the heat resistant coating has a thickness of 0.1 to 10 μm. The laminated film of claim 1 or 2, wherein the resin substrate is composed of a heat-sealable thermoplastic resin layer. The laminated film according to claim 1 or 2, wherein the resin substrate has a heat-sealable thermoplastic resin layer and a layer containing an acid-modified olefin-based resin. The laminated film of claim 5, wherein the resin substrate is formed by co-extruding a heat-sealable thermoplastic resin and an acid-modified olefin-based resin. The laminated film of claim 1 or 2, wherein the heat resistant coating has a printed layer thereon. The laminated film according to claim 1 or 2, wherein the resin substrate is a resin substrate having a printing layer on a surface layer having a heat resistant coating layer. A packaging material characterized by using the laminated film according to any one of claims 1 to 8. The packaging material of claim 9, wherein the laminated film is used in a monomer form. The packaging material according to claim 9 or 10, which is obtained by forming a side surface of the heat-sealable thermoplastic resin layer of the laminated film as an inner surface.