Anti-fog coating composition and its uses

Abstract

To provide a coating composition, which is a coating composition that can form an anti-fogging coating on a heat-fusible polymer-containing film surface or the like, and can form a film in which anti-fogging property, heat seal strength (easy seal-open property), and low blocking property are balanced at a high level.SOLUTION: Provided is a coating composition in which the ratio (P4 / P2) of the absorption peak height (P2) at 1730 cm-1±30 cm-1 and the absorption peak height (P4) at 1560±30 cm-1 is 0.08 or more and 1.80 or less in reflection IR spectrum measurement.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a coating composition, and more specifically to a coating composition capable of forming a coating layer having an excellent balance of anti-fogging properties, easy-open properties, and low blocking properties, and uses thereof. [Background technology]

[0002] Polymer films are widely used for food packaging containers due to their excellent formability, safety, quality retention, etc. Water vapor from the contents of food packaging containers may adhere to the surface of the container as water droplets. In this case, the contents (food) of the food packaging container may become invisible, or the food may deteriorate due to the falling of the adhered water droplets. Therefore, anti-fogging agents are used to impart anti-fogging properties to polymer films for food packaging. For example, a coating composition containing a specific hydrophilic (meth)acrylic resin, an antifogging agent, and a hydrophilic polymer has been proposed as an antifogging agent having excellent antifogging and oil resistance (see, for example, Patent Document 1).

[0003] When a coating agent is applied to the surface of a polymer film, the surface condition changes, which can result in changes in blocking properties and heat-sealing properties. Heat-sealable polymer films used as lids for food packaging containers, etc., are required to have low blocking properties during storage and appropriate heat-sealing strength when opened. Therefore, there is a strong demand for a coating agent that can form a coating layer that has an excellent balance of anti-fogging properties, heat-sealing strength (easy opening), and low-blocking properties without adversely affecting the blocking properties and heat-sealing properties of the heat-sealable layer of the polymer film. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-94422 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above technical background, an object of the present invention is to provide a coating composition capable of forming an anti-fog coating on the surface of a film containing a heat-fusible polymer, and capable of forming a film having a high level of balance among anti-fog properties, heat seal strength (easy opening), and low blocking properties. [Means for solving the problem]

[0006] As a result of extensive research, the present inventors have found that by applying a composition having a specific reflected infrared spectral peak to a heat-sealable polymer film, the anti-fogging properties can be significantly improved without substantially impairing the heat seal strength (easy opening property) and low blocking properties of the polymer film, and have thus completed the present invention. That is, the present invention provides: [1] In the reflection IR spectrum measurement, 1730 cm -1 ±30cm -1 The absorption peak height (P2) is 1560±30cm -1 The coating composition has a ratio (P4 / P2) of absorption peak heights (P4) of 0.08 or more and 1.80 or less.

[0007] The following [2] to

[11] are all preferred aspects or embodiments of the present invention. [2] In the reflection IR spectrum measurement, 1730 cm -1 ±30cm -1 The absorption peak height (P2) is 1630±30cm -1 The coating composition according to [1], wherein the ratio (P3 / P2) of the absorption peak height (P3) to the absorption peak height (P2) is 0.03 or more and 0.60 or less. [3] In the reflection IR spectrum measurement, 1730 cm -1 ±30cm -1 The absorption peak height (P2) is 3400±30cm -1The coating composition according to [1] or [2], wherein the ratio (P1 / P2) of the absorption peak height (P1) to the absorption peak height (P2) is 0.10 or more and 0.58 or less. [4] The coating composition according to any one of [1] to [3], which has a melting point peak at 35±25°C in DSC measurement. [5] The coating composition according to [4], further having melting point peaks at 15.3±5°C and 118±15°C in DSC measurement. [6] The coating composition according to any one of [1] to [5], comprising (a) a low molecular weight surfactant and (b) a polymer surfactant. [7] The coating composition according to [6], wherein (a) the low molecular weight surfactant comprises a nonionic surfactant. [8] (b) The coating composition according to [6] or [7], wherein the polymer surfactant includes an acrylic surfactant. [9] An easily openable film comprising a heat-sealable layer (A), an intermediate layer (B), and a laminate layer (C) laminated in this order, and having a coating layer formed from the coating composition according to any one of [1] to [8] on the heat-sealable layer (A).

[10] The easy-open film according to [9], wherein the heat-sealing layer (A) contains at least one of polyethylene terephthalate, an ethylene-based (co)polymer, and a propylene-based (co)polymer.

[11] [9] or

[10] . An easy-open package comprising a lid material having the easy-open film according to [9] or

[10] and a container. [Effects of the Invention]

[0008] The coating composition of the present invention can form a coating layer on a substrate such as a heat-sealable film, which combines highly practical properties such as anti-fogging property, heat seal strength (easy opening), and low blocking property at a high level that exceeds the limits of conventional technology. The coating composition can be suitably used in a variety of applications, including as a lid material for easy-open plastic containers that store various products such as food, where visibility of the contents is required. [Brief explanation of the drawings]

[0009] [Figure 1] (a) is a schematic diagram of the evaluation criteria for anti-fogging properties, and (b) is a photograph of an actual example of anti-fogging evaluation. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention provides the following in reflectance IR spectrum measurement: In the reflection IR spectrum measurement, 1730 cm -1 ±30cm -1 The absorption peak height (P2) is 1560±30cm -1 The coating composition has a ratio (P4 / P2) of absorption peak heights (P4) of 0.08 or more and 1.80 or less. By having absorption peaks in the above wavelength ranges at the above intensity ratios, the coating composition of the present invention can significantly improve anti-fogging properties without substantially impairing the heat seal strength (easy opening property) and low blocking property of the heat-sealable layer of the polymer film substrate. The reflection IR spectrum of the coating composition of the present invention can be measured by a method commonly used in the art, for example, by applying the coating composition to a film made of a synthetic resin such as polyethylene terephthalate, drying it by heating to form a coating layer with a thickness of about 2 μm, and measuring it by total reflection absorption infrared spectroscopy. More specifically, the measurement can be performed by the method described in the examples of the present application.

[0011] In the reflection IR spectrum measurement, 1730 cm -1 ±30cm -1The absorption peak height (P2) is 1560±30cm -1 The mechanism by which the coating composition of the present invention can achieve the above-mentioned effects by having the ratio (P4 / P2) of the absorption peak height (P4) to the absorption peak height (P2) of 0.08 or more and 1.80 or less is not entirely clear, but -1 , and 1560 cm -1 ±30cm -1 The absorption peaks within this range correspond to ester groups and carbanions, respectively. The presence of these groups and ions at levels observable by IR reflectance spectroscopy is presumed to be somehow related to the ability of these groups and ions to impart anti-fogging properties to the substrate through their surfactant action.

[0012] 1560cm -1 Plus or minus 30cm -1 The intensity of the absorption peak P4 within 1730 cm -1 Plus or minus 30cm -1 Based on the intensity of the absorption peak within the range, it is preferably 0.1 to 1.7 times, and more preferably 0.15 to 1.5 times that value. That is, (P4 / P2) is preferably 0.1 or more and 1.7 or less, and more preferably 0.15 or more and 1.5 or less. The peak intensity P4 on the reflection IR spectrum measured above was obtained by infrared total reflection measurement (ATR method). From the obtained infrared absorption spectrum, the absorption peak height was calculated by the following procedure (4) and used as the peak intensity. (4) 1,530 m -1 and 1780cm -1 The absorbance baselines of the 1560cm -1 Draw a line (R) vertically from the absorbance peak of the sample, and measure the length of the line (R) from the intersection of line (R) and line (P) to the peak. -1 The peak intensity is 1560cm -1 Plus or minus 30cm -1The intensity of the absorption peak within the range can be increased by adding a compound having a carbanion and increasing the amount of the compound added, for example, by using a quaternary ammonium salt or a carboxylate and increasing the amount of the compound added.

[0013] The peak intensity P2 on the reflection IR spectrum measured above is obtained by infrared total reflection measurement (ATR method). From the obtained infrared absorption spectrum, the absorption peak height is calculated using the following procedure (2), and this is used as the peak intensity. (2) 1530cm -1 and 1780cm -1 The absorbance baselines of the -1 Draw a line (R) vertically from the absorbance peak of the sample, and measure the length of the line (R) from the intersection of line (R) and line (P) to the peak. -1 The absorption peak intensity is 1730cm -1 Plus or minus 30cm -1 The intensity of the absorption peak within the range can be increased by adding a compound having an ester group and increasing the amount of the compound added. For example, it can be increased by using a (co)polymer of a (meth)acrylic monomer and increasing the amount of the compound added.

[0014] 3400cm -1 Plus or minus 30cm -1 There is no particular limitation on the intensity P1 of the absorption peak within 1730 cm -1 Plus or minus 30cm -1 Based on the intensity of absorption peak P2 within the range, it is preferably 0.15 to 0.55 times, more preferably 0.20 to 0.50 times, and even more preferably 0.25 to 0.48 times that intensity. In other words, (P1 / P2) is preferably 0.1 or more and 0.55 or less, and more preferably 0.2 or more and 0.5 or less. The peak intensity P1 on the reflection IR spectrum measured above is obtained by infrared total reflection measurement (ATR method). From the obtained infrared absorption spectrum, the absorption peak height is calculated by the following procedure (1), and this is used as the peak intensity. (1) 3040m -1 and 3800 cm -1 Connect the absorbance baselines of the -1 Draw a line (O) vertically from the absorbance peak of the sample, and measure the length of the line (O) from the intersection of line (N) and line (O) to the peak. -1 The peak intensity is 3400cm -1 Plus or minus 30cm -1 The intensity of the absorption peak within the range can be increased by adding a compound having an OH group, an NH group, and / or a COOH group and by increasing the amount of the compound added. For example, the intensity can be increased by using a glycerin fatty acid ester as the (a) low-molecular-weight surfactant described below and by increasing the amount of the glycerin fatty acid ester used.

[0015] 1630cm -1 Plus or minus 30cm -1 There is no particular limitation on the intensity P3 of the absorption peak within 1730 cm -1 Plus or minus 30cm -1 Based on the intensity P2 of the absorption peak within the range, it is preferably 0.03 to 0.60 times, more preferably 0.05 to 0.6 times, and particularly preferably 0.1 to 0.55 times. That is, (P3 / P2) is preferably 0.03 or more and 0.60 or less, preferably 0.1 or more and 0.55 or less, and more preferably 0.2 or more and 0.5 or less. Regarding the peak intensity P3, the corresponding peak on the reflection IR spectrum measured above is obtained by infrared total reflection measurement (ATR method). From the obtained infrared absorption spectrum, the absorption peak height is calculated by the following procedure (3), and this is used as the peak intensity. (3) 1,530 m -1 and 1780cm -1 The absorbance baselines of the 1630cm-1 Draw a line (R) vertically from the absorbance peak of the sample, and measure the length of the line (R) from the intersection of line (R) and line (P) to the peak. -1 The absorption peak height is taken as the peak intensity. 1630cm -1 Plus or minus 30cm -1 The intensity of the absorption peak within the range can be increased by adding a compound having an amide group and increasing the amount of the compound added, for example, by using a quaternary ammonium salt and increasing the amount of the compound added.

[0016] The coating composition of the present invention preferably has a melting point peak at 35±25° C. in DSC measurement. Here, the melting point peak in DSC measurement refers to an endothermic peak observed during the second heating process in DSC measurement under the following thermal history conditions: the coating composition is vacuum dried at 100°C for 7 hours, the first heating is 30 to 150°C at a heating rate of 10°C / min, and held for 1 minute after heating; then a cooling step (150 to -100°C, cooling rate of 10°C / min, and held for 1 minute after heating); and the second heating is -100 to 150°C at a heating rate of 10°C / min, and held for 1 minute after heating. By having a melting point peak at 35±25°C, i.e., by containing a component having a melting point peak at 35±25°C, the coating composition of the present embodiment can impart anti-fogging properties to a polymer film or the like having heat-fusible properties without impairing the properties, particularly heat-sealing performance, of the film. As the component having a melting point peak of 35±25° C., (a) a low molecular weight surfactant, which will be described later, can be preferably used, and more preferably, a glycerin fatty acid ester can be used.

[0017] The coating composition of the present invention preferably has a melting point peak at 15.3±5° C. in DSC measurement. By having a melting point peak at 15.3±5°C, i.e., by containing a component having a melting point peak at 15.3±5°C, the coating composition of the present embodiment can impart anti-fogging properties without impairing the properties of the heat-fusible polymer film, in particular, heat sealability, easy opening, sealability, transparency, etc. As the component having a melting point peak of 15.3±5° C., (a) a low molecular weight surfactant, which will be described later, can be preferably used, and more preferably diglycerin monolaurate can be used.

[0018] The coating composition of the present invention preferably has a melting point peak at 118°C ± 15°C in DSC measurement. By having a melting point peak at 118°C ± 15°C, i.e., by containing a component having a melting point peak at 118°C ± 15°C, the coating composition of the present embodiment can impart anti-fogging properties without impairing the properties of a heat-fusible polymer film, in particular low blocking properties, slip properties, transparency, etc. As the component having a melting point peak of 118°C ± 15°C, the polymer surfactant (b) described below can be preferably used, and more preferably an acrylic surfactant can be used.

[0019] The coating composition of the present invention may have any constituents as long as the reflected IR spectrum has an absorption peak with the above-mentioned intensity ratio, but preferably contains (a) a low-molecular-weight surfactant and (b) a polymeric surfactant. The inclusion of (a) a low-molecular-weight surfactant can impart anti-fogging properties to a heat-sealable polymeric film or the like without impairing its properties, particularly heat-sealing performance, easy opening, sealability, transparency, etc. The inclusion of (b) a polymeric surfactant can impart anti-fogging properties to a heat-sealable polymeric film or the like without impairing its properties, particularly low blocking, slip properties, transparency, etc.

[0020] (a) Low molecular weight surfactants There are no particular limitations on the (a) low-molecular-weight surfactant used in the coating composition of this embodiment, and any low-molecular-weight compound that exhibits surface-active properties can be used as the (a) low-molecular-weight surfactant. Here, "low molecular weight" means a molecular weight of 5,000 or less. (a) The molecular weight of the low molecular weight surfactant is preferably 3,000 or less, and particularly preferably 1,500 or less. (a) The low molecular weight surfactant may be any of an anionic low molecular weight surfactant, a cationic low molecular weight surfactant, and a nonionic low molecular weight surfactant. From the viewpoint of the stability and anti-fogging properties of the coating composition, nonionic low-molecular surfactants are preferred, and fatty acid ester low-molecular surfactants are particularly preferred.

[0021] Preferred examples of the anionic low-molecular-weight surfactant include alkyl sulfates such as sodium lauryl sulfate, triethanolamine lauryl sulfate, and potassium lauryl sulfate; alkylaryl sulfonic acids such as lignin sulfonates, alkylbenzene sulfonates, and alkylnaphthalene sulfonates, and salts thereof; sulfosuccinates such as polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylaryl ether sulfates, disodium lauryl sulfosuccinate, disodium polyoxyethylene alkyl lauryl sulfosuccinate, and dioctyl sodium sulfosuccinate; lauryl phosphoric acid; polyoxyethylene alkyl ether phosphates; polyoxyethylene alkylaryl ether phosphates; and polyoxyethylene styrenated phenol ether sulfates.

[0022] Preferred examples of cationic low-molecular-weight surfactants include alkyltrimethylammonium halide salts such as lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, lauryltrimethylammonium bromide, and stearyltrimethylammonium bromide; alkyldimethylbenzylammonium halide salts such as lauryldimethylbenzylammonium chloride, stearyldimethylbenzylammonium chloride, stearyldimethylbenzylammonium chloride, and tri(polyoxyethylene)stearylammonium chloride; stearylpentaethoxyammonium chloride; and chloro-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethylcellulose.

[0023] Preferred examples of the nonionic low-molecular surfactant include alkylolamides such as lauric acid diethanolamide, lauric myristic acid diethanolamide, myristic acid diethanolamide, and polyoxyethylene stearic acid amide; polyoxyethylene alkylphenyl ethers such as polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, and polyoxyethylene dinonylphenyl ether; polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene cetyl ether, and polyoxyethylene stearyl ether; polyethylene glycol fatty acid esters such as polyethylene glycol monooleate, polyethylene glycol dioleate, polyethylene glycol monostearate, and polyethylene glycol distearate; decaglycerin monocaprylate, glycerin monostearate, sorbitan monocaprylate, sorbitan monolaurate, and sorbitan monopalmitate; Examples of the sorbitan fatty acid esters include sorbitan monostearate, sorbitan distearate, sorbitan trioleate, sorbitan sesquioleate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan trioleate; sorbit fatty acid esters such as polyoxyethylene sorbit monooleate and polyoxyethylene sorbit tetraoleate; polyoxyethylene polyoxypropylene alkyl ethers (blocked), polyoxyethylene polyoxypropylene glycol, and ethylenediaminetetrapolyoxyethylene polyoxypropylene; polyoxyethylene alkylaryl ethers; polyoxyethylene styrenated phenol ethers; polyoxyethylene alkyl esters; and polyoxyethylene styrenated phenol ether polymers. Among these, fatty acid esters are preferred, polyhydric alcohol fatty acid esters are more preferred, and glycerin fatty acid esters are particularly preferred. More specifically, glycerin monostearate, glycerin monolaurate, diglycerin monostearate, diglycerin monolaurate, decaglycerin oleate, decaglycerin laurate, etc. can be particularly preferably used.

[0024] (b) Polymer surfactants There are no particular limitations on the polymer surfactant (b) used in this embodiment, and any polymer compound that exhibits surface activity can be used as the polymer surfactant (b). Here, "polymer" means a molecular weight of at least 5000. The molecular weight of (b) the polymer surfactant is preferably 10,000 to 1,000,000, and particularly preferably 10,000 to 500,000.

[0025] The (b) polymer surfactant is preferably water-soluble. There are no particular limitations on the structure of the (b) polymer surfactant, but it is desirable for the polymer surfactant to have a structure that exhibits water solubility as a whole by having a water-insoluble polymer main chain and water-soluble groups in its side chains. (b) The polymer surfactant may be any of anionic polymer surfactants, cationic polymer surfactants, and nonionic polymer surfactants. Which of these it is usually depends on the type, number, proportion, etc. of the side chain groups. (b) The polymer surfactant may be any of a natural polymer surfactant, a semi-synthetic polymer surfactant, and a synthetic polymer surfactant, but from the viewpoints of control of the structure and physical properties and ease of availability, a synthetic polymer surfactant is preferable.

[0026] Preferred examples of the anionic polymer surfactant include (co)polymers of (meth)acrylic acid, maleic acid, etc., carboxymethyl cellulose, carboxy starch, (meth)acrylic acid grafted starch, sodium alginate, sodium pectinate, xanthan gum, etc. Among these, acrylic polymer surfactants, that is, (co)polymers of (meth)acrylic monomers are preferably used.

[0027] Examples of the (meth)acrylic monomer used in the (co)polymer of a (meth)acrylic monomer include a (meth)acrylic monomer having a hydroxy group, a (meth)acrylic monomer having a carboxy group, a (meth)acrylic acid ester monomer, a (meth)acrylic monomer having a silyl group, and a (meth)acrylic monomer having an isocyanate group.

[0028] The (meth)acrylic monomer having a hydroxy group is not particularly limited, but examples thereof include 2-hydroxyethyl (meth)acrylate (HEMA), 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, 2,3-dihydroxypropyl (meth)acrylate, etc. Of these, it is preferable to use 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate, and 2-hydroxypropyl acrylate.

[0029] The (meth)acrylic monomer having a carboxy group is not particularly limited, and examples thereof include unsaturated monocarboxylic acids such as (meth)acrylic acid, ((meth)acryloyloxy)acetic acid, 2-carboxyethyl (meth)acrylate, 3-carboxypropyl (meth)acrylate, 1-[2-((meth)acryloyloxy)ethyl] succinate, 1-(2-(meth)acryloyloxyethyl) phthalate, 2-((meth)acryloyloxy)ethyl hydrogen hexahydrophthalate, and lactone-modified products thereof; and carboxy group-containing polyfunctional (meth)acrylates obtained by reacting unsaturated dicarboxylic acids (maleic acid, etc.) or acid anhydrides (succinic anhydride, maleic anhydride, etc.) with hydroxy group-containing polyfunctional (meth)acrylates (pentaerythritol triacrylate). Among these, from the viewpoint of ease of adjusting the acid value, it is preferable to use methacrylic acid, (acryloyloxy)acetic acid, 2-carboxyethyl acrylate, and 3-carboxypropyl acrylate, and it is more preferable to use methacrylic acid.

[0030] The (meth)acrylic acid ester monomer is not particularly limited, but examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-pentafluoropropyl (meth)acrylate, perfluorocyclohexyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, β-(Perfluorooctyl)ethyl (meth)acrylate, Glycidyl (meth)acrylate, Allyl glycidyl ether, 2-Hydroxyethyl (meth)acrylate, 2-Hydroxypropyl (meth)acrylate, Polyethylene glycol mono(meth)acrylate, Glycerol mono(meth)acrylate, Aminoethyl (meth)acrylate, N-Monoalkylaminoalkyl (meth)acrylate, N,N-Dialkylaminoalkyl (meth)acrylate, 2-Aziridinylethyl (meth)acrylate, Dicyclopentenyl (meth)acrylate, Allyl (meth)acrylate, Acetoacetoxyethyl (meth)acrylate, Ethylene glycol di(meth)acrylate, 1,6-Hexanediol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, Trimethylolpropane tri(meth)acrylate Examples of the di(meth)acrylate include polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and allyl (meth)acrylate.

[0031] The (meth)acrylic monomer having a silyl group is not particularly limited, but examples thereof include γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, and γ-(meth)acryloxypropyltriisopropoxysilane.

[0032] The (meth)acrylic monomer having an isocyanate group is not particularly limited, but examples thereof include (meth)acryloyl isocyanate, and phenol or methyl ethyl ketoxime adducts of (meth)acryloyl isocyanate ethyl.

[0033] Furthermore, the other monomer is not particularly limited, but examples thereof include vinyl esters, vinyl ethers, nitrile group-containing ethylenically unsaturated monomers, vinyl compounds having an aromatic ring, polymerizable monomers containing a methylolamide group or an alkoxylated thereof, silyl group-containing polymerizable monomers, oxazoline group-containing polymerizable monomers, amide group-containing polymerizable monomers, carbonyl group-containing polymerizable monomers, and other compounds. When other monomers are used, the proportion of the structural units derived from the other monomers in the acrylic polymer surfactant is preferably 10 to 90 mol %, and particularly preferably 30 to 70 mol %.

[0034] Commercially available acrylic polymer surfactants that can be used in the present invention include, for example, Dexnol RS-811 (manufactured by Nippon Nyukazai Co., Ltd.), BYK-3441 (manufactured by BYK Japan KK), BYK-350 (manufactured by BYK Japan KK), BYK-381 (manufactured by BYK Japan KK), and Elecut C048 (manufactured by Takemoto Yushi Co., Ltd.).

[0035] Other preferred examples of the anionic polymer surfactant include polyvinylpyridine, polyvinylpyrrolidone, polyethyleneimine, cationic starch, and chitosan.

[0036] Preferred examples of nonionic polymer surfactants include polyoxyethylene-polyoxypropylene, polyvinyl alcohol, polyvinyl ether, polyacrylamide, ethylene oxide adducts of alkylphenol formaldehyde condensates, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, corn starch, and various starches.

[0037] Further, more specific examples of suitable polymer surfactants include the following: (1) Poly(4-vinylpyridine)-type cationic surfactants (2) Graft copolymers of cationic derivatives of linear polysaccharides and olefin monomers (3) Copolymers of cationic monomers and nonionic monomers (e.g., copolymers of alkylvinylpyridinium and alkylene oxide adducts of alkylvinyl alcohol). (4) Poly(2-hydroxy-3-methacryloyloxypropyltrimethylammonium chloride) (5) Polydimethylaminoethyl methacrylate (6) Salts of acrylic acid polymers with alkali metals, amines, and ammonia (7) Copolymers of maleic anhydride and acrylic acid and their salts with alkali metals, amines, and ammonia (8) Copolymers of itaconic acid and acrylic acid and their salts with alkali metals, amines, and ammonia (9) Alkali metal salts of sulfonated styrene-maleic anhydride copolymer (10) Alkali metal salts of polyvinyl sulfonic acid (11) Alkali metal salts of polystyrene sulfonic acid (12) Polymethacryloyloxypropylsulfonic acid (13) Alkali metal salts of polyepoxysuccinic acid (14) Formalin condensate of sodium naphthalenesulfonate (15) Melamine-sulfonic acid formalin condensate (16) Copolymer of alkylaminoalkyl(meth)acrylamide and alkylacrylamide(meth)acrylate or acrylonitrile (17) Fatty acid dextrin (18) Carboxymethylcellulose (19) Polyvinyl alcohol (20) Polyoxyethylene (hereinafter abbreviated as POE)-polyoxypropylene (hereinafter abbreviated as POP) block polymer (21) Ethylenediamine-POE·POP Block Polymer (22) POE-POP triblock polymer

[0038] solvent The coating composition may contain a solvent such as water or an organic solvent, if necessary. The solvent is not particularly limited, but water, a water-soluble solvent, a non-water-soluble solvent, etc. can be preferably used. Here, the term "water-soluble solvent" refers to a solvent that, when gently stirred with an equal volume of pure water at 1 atmosphere and 20°C, has a uniform appearance after the flow has subsided. On the other hand, the term "non-aqueous solvent" refers to a solvent that, when gently stirred with an equal volume of pure water at 1 atmosphere and 20°C, does not have a uniform appearance after the flow has subsided.

[0039] The water-soluble solvent is not particularly limited, but preferred examples thereof include alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol methyl ether, and diethylene glycol methyl ether; ketones such as acetone; and ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether.

[0040] Preferred examples of the non-water-soluble solvent include ketones such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; hydrocarbons such as hexane, heptane, and octane; aromatics such as benzene, toluene, xylene, and cumene; and esters such as ethyl acetate and butyl acetate.

[0041] These solvents may be used alone or in combination of two or more. There is no particular limitation on the amount of solvent used, but in the above embodiment, when the entire coating composition is taken as 100 parts by mass, it is preferable to use an amount such that the total amount of (a) the low-molecular-weight surfactant and (b) the polymer surfactant is 0.1 to 15 parts by mass, and it is particularly preferable to use an amount such that 0.1 to 5.0 parts by mass.

[0042] Other ingredients The coating composition may contain additives other than (a) the low-molecular-weight surfactant, (b) the polymer surfactant, and the solvent, as needed. The additives are not particularly limited, but examples include anti-fogging aids, slip agents (such as silicone emulsions containing polydimethylsiloxane as a main component), antistatic agents, antioxidants, antibacterial agents, ultraviolet absorbers, etc. These additives may be used alone or in combination of two or more.

[0043] Applications of coating compositions The form of use of the coating composition is not particularly limited, but it is preferable to apply it to a film substrate such as a heat-sealable film to form a coating layer. The coating method is not particularly limited, but preferred examples include a spray coater, a roll coater, a gravure roll coater, a knife coater, an air knife coater, a rotor dampening, and an applicator system.

[0044] In forming the coating layer, heating and drying may be carried out after coating. There are no particular limitations on the drying temperature either, but when coating on a heat-fusible polymer film, it is preferable to dry at a temperature not exceeding the glass transition temperature (Tg) of the film. The drying time is not particularly limited, but is preferably 0.01 to 10 minutes, and more preferably 0.05 to 3 minutes.

[0045] There are no particular restrictions on the thickness of the coating layer, but it is preferably 0.2 to 0.005 μm, and particularly preferably 0.1 to 0.005 μm. In addition, when specifying the coating amount (mass) of the coating layer, from the viewpoint of not impairing the function of the substrate film, the coating amount of the coating layer is 0.2 g / m after drying. 2 It is preferable that: On the other hand, in order to fully realize the effect of the coating, the coating amount of the coating layer is set to 0.005 g / m after drying. 2 It is preferable that this is equal to or greater than this. The coating weight of the coating layer after drying is 0.2 to 0.005 g / m 2 More preferably, it is 0.1 to 0.005 g / m 2 It is particularly preferred that: The amount of coating layer applied can be calculated from the difference in mass between the heat-sealable film before and after the coating layer is formed, and the area of ​​the heat-sealable film.

[0046] polymer film Although there are no particular limitations on the substrate to which the coating composition of the present invention is applied, it is preferable to apply it to a polymer film having heat-sealing properties. In this case, it is possible to form a coating layer that is excellent in balance between anti-fogging properties, heat-sealing strength (easy opening), and low blocking properties without adversely affecting the blocking properties and heat-sealing properties of the polymer film having heat-sealing properties (heat-sealing layer). The heat-fusible polymer film in this embodiment preferably contains at least one of polyester, ethylene-based (co)polymer, and propylene-based (co)polymer, and particularly preferably contains at least one of polyethylene terephthalate, ethylene-based (co)polymer, and propylene-based (co)polymer. When the coating composition of the present invention is applied to a heat-fusible polymer film containing any of these, it can form a coating layer that has an excellent balance of anti-fogging properties, heat seal strength (easy opening), and low blocking properties.

[0047] polyester The polyester contained in the polymer film of this embodiment is preferably amorphous (non-crystalline) or low-crystalline from the viewpoint of realizing excellent heat-sealing properties. The polyester may contain, as a dibasic acid component, a component selected from phthalic acid, terephthalic acid, isophthalic acid, adipic acid, sebacic acid, naphthalenedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-phenylenedioxydiacetic acid, and their structural isomers, dicarboxylic acids or derivatives thereof such as malonic acid, succinic acid, and adipic acid, p-hydroxybenzoic acid, p-hydroxybenzoic acid esters, and oxyacids or derivatives thereof such as glycolic acid, and ethylene glycol as a glycol component. The dibasic acid component and the glycol component can be subjected to a transesterification reaction or an esterification reaction, followed by a melt polycondensation reaction, to obtain a product which can be used.

[0048] Lactic acid polymers can also be used as polyesters, and examples thereof include, but are not limited to, poly(D-lactic acid), poly(L-lactic acid), copolymers of D-lactic acid and L-lactic acid, copolymers of D-lactic acid and other hydroxycarboxylic acids, copolymers of L-lactic acid and other hydroxycarboxylic acids, blends of these, and copolymers of polyester components obtained by esterifying dicarboxylic acids and diols with lactic acid components. Among these, polylactic acid whose main structural unit is L-lactic acid is particularly preferred from the viewpoint of film formation stability.

[0049] Examples of the hydroxycarboxylic acid, diol, and dicarboxylic acid include hydroxycarboxylic acids such as hydroxycaproic acids such as glycolic acid, hydroxybutyric acid, and hydroxycaproic acid, and cyclic lactones such as caprolactone, butyrolactone, lactide, and glycolide; aliphatic diols such as ethylene glycol, propylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; and aliphatic dicarboxylic acids such as succinic acid, adipic acid, suberic acid, and sebacic acid.

[0050] The polyester used in this embodiment is preferably polyethylene terephthalate, and an amorphous copolymerized polyethylene terephthalate resin having a glass transition temperature Tg of about -20 to 90°C, preferably -15 to 85°C, which is a combination of a dibasic acid component and a glycol component, is particularly suitable.

[0051] Ethylene (co)polymer The polymer film in this embodiment preferably contains an ethylene-based (co)polymer in the heat-sealable layer, more preferably in an amount of 1 to 99 mass % based on the mass of the heat-sealable layer. When the content of the ethylene-based (co)polymer is 10% by mass or more, heat fusion bonding property is exhibited, which contributes to realizing the effects of the present embodiment. The content of the ethylene-based (co)polymer is more preferably 18% by mass or more, and particularly preferably 47% by mass or more. When the content of the ethylene-based (co)polymer is 90% by mass or less, the easy-open property is exhibited, which contributes to realizing the effect of the present embodiment. The content of the ethylene-based (co)polymer is preferably 85% by mass or less, and particularly preferably 80% by mass or less.

[0052] The type of ethylene-based (co)polymer is not particularly limited, and may be either a homopolymer of ethylene or a copolymer of ethylene and a monomer other than ethylene. In the case of a copolymer of ethylene and a monomer other than ethylene, the proportion of ethylene-derived structural units exceeds 50 mol%. When the proportion of ethylene-derived structural units exceeds 50 mol%, the ethylene-based (co)polymer is distinguished from the propylene-based (co)polymers described below. The proportion of ethylene-derived structural units is preferably 55 mol% or more, and particularly preferably 60 mol% or more.

[0053] The ethylene-based (co)polymer may be used alone or in combination of two or more kinds. From the viewpoint of controlling the heat-sealing property of the polymer film, it is preferable to use two or more types in combination. 3 More than 960kg / m 3 and an ethylene polymer having a density of 900 kg / m 3 It is particularly preferable to use these in combination with a propylene-based (co)polymer, a tackifying resin, etc., which will be described later.

[0054] Density is 900 kg / m 3 More than 960kg / m 3 The following ethylene (co)polymers (i): The polymer film in this embodiment has a density of 900 kg / m 3 More than 960kg / m 3 It is preferable to contain the following ethylene (co)polymer (hereinafter also referred to as ethylene (co)polymer (i)), more preferably in an amount of 1 to 50 mass %. It is preferable that the ethylene (co)polymer (i) is contained in an amount of preferably 1% by mass or more from the viewpoints of heat-sealing properties, easy opening properties, sealability, and the like. The content of the ethylene (co)polymer (i) of 50% by mass or less improves impact resistance, contributing to realizing the effects of the present embodiment. The content of the ethylene (co)polymer (i) is preferably 45% by mass or less, and particularly preferably 35% by mass or less.

[0055] The ethylene (co)polymer (i) has a ratio of structural units derived from ethylene of 50 mol % or more, and therefore a ratio of structural units derived from propylene of less than 50 mol %, and is therefore distinguishable from propylene polymers in this respect. 3 The density described below is 900 kg / m or more. 3 It is distinguished from ethylene-α-olefin copolymers (ii) below.

[0056] The ethylene (co)polymer (i) has a density of 900 to 960 kg / m 3 , preferably 905 to 930 kg / m 3 , more preferably 908 to 920 kg / m 3 is in the range. The density of the ethylene (co)polymer (i) can be measured by Method D (density gradient tube method) of JIS K 7112 using a sample treated with boiling water for 30 minutes. The density of the ethylene (co)polymer (i) can be adjusted by a conventionally known method. For example, the density can be reduced by increasing the amount of copolymerization components other than ethylene or by increasing the amount of branches by a high-pressure method.

[0057] The ethylene (co)polymer (i) may be a homopolymer of ethylene, or a copolymer of ethylene with other copolymerization components such as an α-olefin having 3 to 10 carbon atoms. As the other copolymerization component, as described above, it is preferable to use an α-olefin having 3 to 10 carbon atoms, such as propylene, 1-butene, 1-heptene, 1-hexene, 1-octene, or 4-methyl-1-pentene, but the present invention is not limited thereto, and other copolymerization components such as polyenes such as dienes, polar monomers, etc. When the ethylenic (co)polymer (i) is a copolymer, it may be either a random copolymer or a block copolymer, but is preferably a random copolymer. The content of the structural units derived from other copolymerization components may be less than 50 mol %, but is usually 30 mol % or less, and particularly preferably 20 mol % or less.

[0058] In terms of polymer classification, suitable examples of ethylene (co)polymers (i) include ethylene homopolymers or ethylene-α-olefin copolymers called high-pressure low-density polyethylene (HP-LDPE), linear or straight-chain low-density polyethylene (L-LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE). Details of these suitable polymers are as follows: 3 More than 960kg / m 3 As long as the following conditions are met, it is similar to what is conventionally known in the art.

[0059] Density is 900 kg / m 3 More than 960kg / m 3 The following ethylene (co)polymers (i) may be used singly or in combination of two or more.

[0060] Density is 900 kg / m 3 More than 960kg / m 3 The melt flow rate (MFR) (ASTM D1238, 190°C, 2160 g load) of the following ethylene (co)polymer (i) is not particularly limited as long as it has film-forming ability when used alone or mixed with other components, but is usually in the range of 0.01 to 100 g / 10 min, preferably 0.1 to 70 g / 10 min. The melt flow rate of the ethylene (co)polymer (i) can be adjusted by a method conventionally used in the art. For example, the melt flow rate can be increased by decreasing the molecular weight or increasing the molecular weight distribution.

[0061] The molecular weight distribution (M) of ethylene-based (co)polymers (i) measured by gel permeation chromatography (GPC) w / M n ) is usually in the range of 1.5 to 4.0, preferably 1.8 to 3.5. The ethylene (co)polymer (i) also preferably has one or more sharp endothermic peaks determined from an endothermic curve measured with a differential scanning calorimeter (DSC) at a heating rate of 10°C / min, and the maximum temperature of the peak, i.e., the melting point, is usually in the range of 50 to 130°C, preferably 60 to 120°C.

[0062] The ethylene (co)polymer (i) described above can be prepared by a conventionally known production method using a multi-site catalyst, typically a Ziegler catalyst, or a single-site catalyst, typically a metallocene catalyst. For example, linear low-density polyethylene (LLDPE), which is preferably used as the ethylene (co)polymer (i), can be prepared using a catalyst containing a transition metal metallocene compound. This meta-octene catalyst is preferably formed from (a) a transition metal meta-octene compound, (b) an organoaluminum oxy-compound, and (c) a support, and may further be formed from these components and (d) an organoaluminum compound and / or an organoboron compound, as necessary. Olefin polymerization catalysts containing such metallocene compounds and methods for preparing linear low-density polyethylene (LLDPE) using the catalyst are described, for example, in JP-A-8-269270.

[0063] Density is 900 kg / m 3 Ethylene-α-olefin copolymers (ii) The polymer film in this embodiment has a density of 900 kg / m 3 More than 960kg / m 3In addition to or instead of the following ethylene (co)polymer (i), 3 It is preferable that the copolymer contains an ethylene-α-olefin copolymer of less than 100% by weight (hereinafter also referred to as ethylene-α-olefin copolymer (ii)).

[0064] Ethylene-α-olefin copolymer (ii) has a ratio of ethylene-derived structural units of 50 mol% or more, and therefore a ratio of propylene-derived structural units of less than 50 mol%, and is therefore distinguishable from propylene-based (co)polymers in this respect. Also, the density is 900 kg / m 3 Density less than 900 kg / m 3 It is distinguished from the above ethylene (co)polymer (i). Density is 900 kg / m 3 The ethylene-α-olefin copolymer (ii) having a molecular weight of less than 10 ...

[0065] The ethylene-α-olefin copolymer (ii) may be a single copolymer or a combination of two copolymers. A suitable example of the latter is a material with a density of 860 to 895 kg / m 3 and (ii-1) an ethylene-α-olefin random copolymer having at least one α-olefin having 4 to 10 carbon atoms, and a density of 865 to 875 kg / m 3 Examples of the resin composition include an ethylene-propylene random copolymer (ii-2) having a molecular weight of 1000 or more and a molecular weight of 1000 or more. Furthermore, a resin composition can be used that is preferably composed of 10 to 90 parts by mass, particularly preferably 30 to 90 parts by mass, of an ethylene-α-olefin random copolymer (ii-1) and 90 to 10 parts by mass, particularly preferably 70 to 10 parts by mass, of an ethylene-propylene random copolymer (ii-2) (where (ii-1) + (ii-2) = 100 parts by mass).

[0066] The ethylene-α-olefin random copolymer (ii-1) is preferably a polymer having at least one of the following physical properties [ii-1a] to [ii-1c]. [ii-1a] Ethylene content is 85 to 93 mol% [ii-1b] The degree of crystallinity by X-ray is 7-30% [ii-1c] The melting point determined from the endothermic curve measured by a differential scanning calorimeter (DSC) at a heating rate of 10°C / min is in the range of 60-90°C.

[0067] That is, as the ethylene-α-olefin random copolymer (ii-1), an ethylene-α-olefin random copolymer having the physical properties of [ii-1a], [ii-1b], or [ii-1c] is preferred, an ethylene-α-olefin random copolymer having the physical properties of [ii-1a] and [ii-1b], the physical properties of [ii-1a] and [ii-1c], or the physical properties of [ii-1b] and [ii-1c] is more preferred, and an ethylene-α-olefin random copolymer having the physical properties of [ii-1a], [ii-1b], and [ii-1c] is particularly preferred.

[0068] Similarly, the ethylene-propylene random copolymer (ii-2) is preferably a polymer having at least one of the following physical properties [ii-2a] and [ii-2b]. [ii-2a] Ethylene content is 75 to 85 mol% [ii-2b] Amorphous or slightly crystalline with a crystallinity of less than 5% by X-ray That is, as the ethylene-propylene random copolymer (ii-2), an ethylene-propylene random copolymer having the physical properties of [ii-2a] or [ii-2b] is preferred, and an ethylene-propylene random copolymer having the physical properties of [ii-2a] and [ii-2b] is particularly preferred.

[0069] Among these copolymers, in consideration of the heat-sealing properties of the resulting heat-sealable film, compositions (mixtures) consisting of low-crystalline ethylene-α-olefin random copolymers (ii-1) having an ethylene content of 85 to 93 mol%, a crystallinity of 7 to 30% as determined by X-ray analysis, and a melting point in the range of 60 to 90°C as determined from an endothermic curve at a heating rate of 10°C / min by differential scanning calorimetry (DSC), and amorphous or slightly crystalline ethylene-propylene random copolymers (ii-2) having an ethylene content of 75 to 85 mol% and a crystallinity of less than 5% as determined by X-ray analysis, are particularly suitable for use as the ethylene-α-olefin copolymer (ii).

[0070] The density that can be used for the polymer film in this embodiment is 900 kg / m 3 The ethylene-α-olefin copolymer (ii) having a melt flow rate (MFR) (ASTM D1238, 190°C, 2160 g load) of less than 0.01 g / 10 min is not particularly limited as long as it has film-forming ability when used alone or when mixed with other components to form an olefin polymer composition. However, in consideration of the processability, oil resistance, etc. of the olefin polymer composition, the melt flow rate (MFR) (ASTM D1238, 190°C, 2160 g load) is preferably in the range of 0.01 to 20 g / 10 min, more preferably 0.1 to 10 g / 10 min. The density that can be used for the polymer film in this embodiment is 900 kg / m 3 The ethylene-α-olefin copolymer (ii) having a molecular weight of less than 1000 can be obtained, for example, by copolymerizing ethylene with an α-olefin or the like using a catalyst comprising a transition metal compound catalyst component, such as a vanadium compound or a zirconium compound, and an organoaluminum compound catalyst component.

[0071] Propylene (co)polymer The polymer film in this embodiment preferably contains a propylene-based (co)polymer in the heat-sealable layer, more preferably in an amount of 10 to 70% by mass relative to the total mass of the heat-sealable layer. When the content of the propylene-based (co)polymer is 10% by mass or more, the heat-sealing property and rigidity are obtained, which contributes to realizing the effects of the present embodiment. The content of the propylene-based (co)polymer is more preferably 30% by mass or more, and particularly preferably 35% by mass or more. When the content of the propylene-based (co)polymer is 70% by mass or less, the package has easy-open properties, which contributes to realizing the effects of the present embodiment. The content of the propylene-based (co)polymer is preferably 65% ​​by mass or less, and particularly preferably 60% by mass or less.

[0072] Propylene-based (co)polymers are resins generally manufactured and sold under the name of polypropylene, and usually have a density of 890 to 930 kg / m 3 It is a propylene homopolymer or a propylene copolymer, that is, a copolymer comprising propylene and at least one comonomer selected from other α-olefins in small amounts. The copolymer may be a random copolymer or a block copolymer, but a random copolymer is particularly preferred. Examples of other α-olefins in this propylene copolymer include ethylene and α-olefins having about 4 to 20 carbon atoms, such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, and 4-methyl-1-pentene. These other α-olefins may be copolymerized either alone or in combination with two or more α-olefins. The presence of comonomers other than α-olefins is not excluded.

[0073] Propylene-based (co)polymers are distinguished from ethylene-based (co)polymers and the like by having a proportion of propylene-derived structural units of 50 mol % or more. The proportion of propylene-derived structural units is preferably 60 mol % or more, and particularly preferably 70 mol % or more. Since the proportion of propylene-derived structural units is 50 mol% or more, the proportion of comonomer-derived structural units is less than 50 mol%. In ordinary polypropylene, the proportion of comonomer-derived structural units is often 25 mol% or less. In the case of a random copolymer, it is preferably 10 mol% or less, and particularly preferably 5 mol% or less. In the case of a block copolymer, it is preferably 20 mol% or less, and particularly preferably 15 mol% or less.

[0074] Among these propylene (co)polymers, propylene-α-olefin random copolymers having a melting point measured by a differential scanning calorimeter (DSC) in the range of 110 to 145°C, particularly 115 to 140°C, are preferred in terms of the balance between heat-sealability and heat resistance of the resulting heat-sealable film.

[0075] The melt flow rate (MFR) (ASTM D1238, 230°C, 2160 g load) of the propylene (co)polymer is not particularly limited as long as it has film-forming ability either alone or in a state where it is mixed with other components that constitute a polymer film, such as an ethylene (co)polymer or a tackifying resin. From the viewpoint of extrusion processability, however, it is usually in the range of 0.01 to 100 g / 10 min, preferably 0.1 to 70 g / 10 min.

[0076] In the polymer film, two or more kinds of propylene-based (co)polymers can be used in combination as the propylene-based (co)polymer.

[0077] Propylene (co)polymers can be produced by various known production methods, specifically, using olefin polymerization catalysts such as Ziegler-Natta catalysts and single-site catalysts. In particular, they can be produced using single-site catalysts. Single-site catalysts are catalysts with uniform (single-site) active sites, such as metallocene catalysts (so-called Kaminsky catalysts) and Brookhart catalysts. The metallocene catalyst is a catalyst comprising a metallocene transition metal compound and at least one compound selected from the group consisting of organoaluminum compounds and compounds that react with the metallocene transition metal compound to form an ion pair, and may be supported on an inorganic material.

[0078] tackifying resin Tackifying resins that can be used in the polymer film of the present embodiment are known resins that are manufactured and sold as tackifying agents, and specific examples include aliphatic hydrocarbon resins, alicyclic hydrocarbon resins, aromatic hydrocarbon resins, polyterpene resins, rosins, styrene resins, and coumarone-indene resins.

[0079] Examples of aliphatic hydrocarbon resins include resins obtained by polymerizing a fraction containing at least one mono- or diolefin having 4 to 5 carbon atoms, such as 1-butene, isobutene, butadiene, 1,3-pentadiene, and isoprene. Examples of alicyclic hydrocarbon resins include resins obtained by cyclodimerizing and then polymerizing diene components in spent C4-C5 fractions, resins obtained by polymerizing cyclic monomers such as cyclopentadiene, and resins obtained by intranuclear hydrogenation of aromatic hydrocarbon resins. Examples of aromatic hydrocarbon resins include resins obtained by polymerizing fractions containing at least one C8 to C10 vinyl aromatic hydrocarbon such as vinyltoluene, indene, and α-methylstyrene, and resins obtained by copolymerizing these fractions with the above-mentioned aliphatic hydrocarbon fractions.

[0080] Examples of polyterpene resins include α-pinene polymers, β-pinene polymers, dipentene polymers, terpene-phenol copolymers, α-pinene-phenol copolymers, and hydrogenated versions of these. Rosins include gum rosin, wood rosin, tall oil rosin, and modified products thereof, and examples of modified products include those that have been subjected to modifications such as hydrogenation, disproportionation, dimerization, and esterification. Examples of styrene hydrocarbon resins include low molecular weight resinous polymers obtained by polymerizing one or more styrene monomers such as highly pure styrene, vinyltoluene, α-methylstyrene, and isopropyltoluene.

[0081] When the polymer film having heat-sealing properties of this embodiment is used as an easy-open material for packaging food and beverages, taking into consideration odorlessness, food hygiene, miscibility with other components, etc., it is preferable to use a resin obtained by intranuclearly hydrogenating an aromatic hydrocarbon resin or a polyterpene resin as the tackifying resin.

[0082] The composition of the resin constituting the heat-sealable polymer film of this embodiment is not particularly limited, but the above-mentioned density of 900 kg / m 3 It is preferable that the ethylene-α-olefin copolymer (ii) and / or tackifying resin (d) are contained in a total amount of 1 to 50 mass % or less. In this case, as long as the total content of the ethylene-α-olefin copolymer (ii) and / or tackifying resin is 1 to 50 mass %, the ethylene-α-olefin copolymer (ii) alone may be contained, the tackifying resin alone may be contained, or both the ethylene-α-olefin copolymer (ii) and the tackifying resin may be contained.

[0083] When the total content of the ethylene-α-olefin copolymer (ii) and / or tackifying resin is 1% by mass or more, the pouch has heat-sealing properties and is easy to open, which contributes to realizing the effects of the present embodiment. The total content of the ethylene-α-olefin copolymer (ii) and / or tackifying resin is more preferably 5% by mass or more, and particularly preferably 10% by mass or more. By having the total content of the ethylene-α-olefin copolymer (ii) and / or tackifying resin be 99% by mass or less, the film has heat-sealing properties, easy-opening properties, and impact resistance, contributing to realizing the effects of the present embodiment. The total content of the ethylene-α-olefin copolymer (ii) and / or tackifying resin is more preferably 95% by mass or less, and particularly preferably 90% by mass or less.

[0084] The heat-sealable film of this embodiment may contain, in addition to the polyesters, ethylene-based (co)polymers, and propylene-based (co)polymers described above, various additives and fillers, such as heat stabilizers, antioxidants, light stabilizers, antistatic agents, antiblocking agents, lubricants, nucleating agents, flame retardants, pigments, dyes, calcium carbonate, barium sulfate, magnesium hydroxide, mica, talc, clay, antibacterial agents, antifogging agents, etc. Furthermore, other thermoplastic resins, thermoplastic elastomers, rubbers, etc. may also be blended in so far as the object of the present invention is not adversely affected.

[0085] Easy-to-open film The heat-sealable film of this embodiment is a polymer film having the above-mentioned heat-sealable properties and a coating layer formed on the surface thereof, and can be used alone as a heat-sealable film. However, the heat-sealable film of this embodiment may also be used as a heat-sealable layer in combination with other layers to form a laminated film. A laminated film formed by using the heat-sealable film of this embodiment as a heat-sealable layer (A) and laminating this with an intermediate layer (B) and a laminate layer (C) can be preferably used as an easy-open film, etc. That is, an easy-open film formed by laminating, in this order, a heat-sealable layer (A) made of the heat-sealable film of this embodiment, an intermediate layer (B), and a laminate layer (C) is one particularly preferred embodiment of the present invention. Heat-sealing layer (A) The heat-sealable layer (A) constituting the easy-open film of this embodiment is made of the heat-sealable film of the above embodiment, in which a coating layer is formed on the surface of a heat-sealable polymer film. Therefore, the details of the heat-sealable layer (A) are the same as those described above for the heat-sealable film of the above embodiment, and the details of the polymer film and coating layer constituting the heat-sealable layer (A) are also the same as those described above for the above embodiment.

[0086] The heat-sealable layer (A) can be arranged on the packaging container body side and fused to the packaging container body when the easy-open film of the present embodiment is used, for example, as a lid material for a packaging container for food, etc. The heat-sealable layer (A) can be suitably used in such a usage form because the use of the heat-sealable film of the above embodiment provides excellent anti-fogging properties, easy-open properties, low blocking properties, etc.

[0087] There are no particular restrictions on the thickness of the heat-sealable layer (A), but from the viewpoint of sealing properties, it is preferably 1.5 μm or more, and particularly preferably 2 μm or more. On the other hand, from the viewpoint of ease of opening, etc., the thickness is preferably 15 μm or less, and particularly preferably 10 μm or less.

[0088] Middle layer (B) The components of the intermediate layer (B) constituting the easy-open film of this embodiment are not particularly limited, but from the viewpoint of the strength, transparency, lightness, etc. of the easy-open film, it is preferable that it contains a polyolefin, and it is particularly preferable that it contains an ethylene (based) copolymer or a propylene (based) copolymer. Details of the ethylene (based) copolymer and propylene (co)polymer are the same as those described above with respect to the polymer film constituting the heat-sealable film of the above embodiment. In addition, from the viewpoint of adhesion to the heat-sealing layer (A) and the laminate layer (C), the film may contain an acid-modified polyolefin resin, and more preferably an acid-modified polyethylene resin.

[0089] In the intermediate layer (B), ethylene-based (co)polymers can also be preferably used, and preferred examples thereof include polyethylene resins such as very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), linear medium density polyethylene (LMDPE), and medium density polyethylene (MDPE), as well as ethylene-vinyl acetate copolymers (EVA), which can be used alone or in combination of two or more. Among these, LLDPE is preferred because of its good film-forming properties. Preferred examples of acid-modified polyolefins include modified polymers obtained by copolymerizing (e.g., graft-copolymerizing) polyolefins with unsaturated carboxylic acids or their derivatives. Examples of polyolefins include homopolymers of olefins, mutual copolymers (between olefins), and copolymers with other copolymerizable monomers (e.g., other vinyl monomers). Specific examples include polyethylene (LDPE, LLDPE, etc.), polypropylene, polybutene, mutual copolymers thereof, ionomer resins, ethylene-acrylic acid copolymers, and ethylene-vinyl acetate copolymers. Examples of unsaturated carboxylic acids or derivatives thereof include unsaturated carboxylic acids such as maleic acid and fumaric acid, their acid anhydrides, their esters, and their metal salts. Among these, maleic acid-modified polyolefins are preferred. The additives and the like that can be used in the intermediate layer (B) are the same as those explained above in relation to the polymer film used in the heat-sealable layer (A).

[0090] Of the layers constituting the easy-open film of this embodiment, it is preferable that the heat-sealing layer (A) is designed to obtain appropriate sealing properties, etc., and it is preferable that the laminate layer (C) is designed taking into consideration the lamination strength between the base film, etc., while it is preferable that the intermediate layer (B) is designed to obtain adhesion between the heat-sealing layer (A) and the laminate layer (C).

[0091] The thickness of the intermediate layer (B) is preferably 2 μm or more, particularly preferably 3 μm or more. On the other hand, the thickness of the intermediate layer (B) is preferably 45 μm or less, and particularly preferably 43 μm or less.

[0092] Laminate layer (C) The laminate layer (C) constituting the easy-open film of the present embodiment can be laminated with other layers such as the substrate film described below, as necessary or desired. Therefore, it is preferable to design the laminate layer (C) taking into consideration the lamination strength between the laminate layer (C) and other layers, such as the base film. For example, it is preferable to use the same material as the base film and other layers, and therefore it is preferable to use a polyolefin-based material, which is preferably used for the base film. Depending on the type of base material, polyester-based materials such as PET and polyamide-based materials such as nylon can also be used. In addition, in order to further improve the laminate strength between the substrate and the like, the surface of the (C) laminate layer (the surface opposite to the surface to be laminated with the (B) intermediate layer) may be subjected to treatment such as corona treatment or roughening treatment.

[0093] On the other hand, from the viewpoint of improving the lamination strength with the (B) intermediate layer, it is also preferable to use the same type of material as the (B) intermediate layer, more specifically polyolefin, more preferably ethylene polymer. The additives and the like that can be used in the laminate layer (C) are the same as those explained above in relation to the polymer film used in the heat-sealable layer (A).

[0094] When the intermediate layer (B) contains an ethylene-based polymer, the laminate layer (C) preferably also contains an ethylene-based polymer from the viewpoint of lamination strength with the intermediate layer (B). It is particularly preferred that the laminate layer (C) contains a linear low-density polyethylene. There is no particular restriction on the content, but the content of the ethylene polymer in the (C) laminate layer is preferably 50% by mass or more, more preferably 60 to 99.9% by mass, and particularly preferably 80 to 99.9% by mass.

[0095] From the viewpoint of preventing blocking during storage of the easy-open film of this embodiment, the laminate (C) layer may contain an anti-blocking agent. As the anti-blocking agent, powdered silica, preferably synthetic silica, etc., can be suitably used. From the viewpoint of uniformly dispersing the powdered silica in the laminate layer (C), the powdered silica may be dispersed in a resin having excellent miscibility with the material constituting the laminate layer (C), for example, in low-density polyethylene, to form a masterbatch, and then the masterbatch may be added to the material constituting the laminate layer (C).

[0096] There are no particular restrictions on the thickness of the (C) laminate layer, but from the viewpoint of lamination strength, etc., it is preferably 1.5 μm or more, and particularly preferably 2 μm or more. The thickness of the (C) laminate layer is preferably 20 μm or less, and particularly preferably 15 μm or less.

[0097] As described above, the easy-open film of this embodiment has the heat-sealing layer (A), the intermediate layer (B), and the laminate layer (C). In the laminate film of this embodiment, the laminate layer (C) and the heat-sealing layer (A) are preferably laminated via the intermediate layer (B), but other layers may be present, and for example, an adhesive layer may be interposed between the heat-sealing layer (A) and the intermediate layer (B).

[0098] The easy-open film of this embodiment can be produced by various known film forming methods, for example, a method in which films to be the laminate layer (C), the intermediate layer (B), and the heat-sealing layer (A) are formed in advance, and then a coating layer is formed on the heat-sealing layer (A), and these films are bonded together to form a laminated film; a method in which a multilayer film consisting of the intermediate layer (B) and the heat-sealing layer (A) is obtained using a multilayer die, and then the laminate layer (C) is extruded onto the surface of the intermediate layer (B) to form a laminated film, and then a coating layer is formed on the heat-sealing layer (A); a method in which a multilayer film consisting of the laminate layer (C) and the intermediate layer (B) is obtained using a multilayer die, and then the heat-sealing layer (A) is extruded onto the surface of the intermediate layer (B) to form a laminated film, and then a coating layer is formed on the heat-sealing layer (A); or a method in which a laminated film consisting of the laminate layer (C), the intermediate layer (B), and the heat-sealing layer (A) is obtained using a multilayer die, and then a coating layer is formed on the heat-sealing layer (A).

[0099] As the film forming method, various known film forming methods, specifically, a T-die cast film forming method, an inflation film forming method, etc. can be used. The easy-open film of the embodiment and each layer constituting the film may be a non-stretched film (unstretched film) or a stretched film.

[0100] The thickness of the easy-open film of the present embodiment is not particularly limited, but from the viewpoint of ensuring practical strength, etc., it is usually 10 μm or more, preferably 15 μm or more, and more preferably 20 μm or more. On the other hand, from the viewpoint of maintaining practical flexibility even after being laminated with, for example, a base film, etc., it is usually 100 μm or less, preferably 80 μm or less, and more preferably 70 μm or less.

[0101] The easy-open film of the present embodiment may be a stretched film or a non-stretched film, but from the viewpoint of improving mechanical properties, it is preferably a stretched film, and particularly preferably a biaxially stretched film. As the biaxial stretching method, a method such as sequential biaxial stretching, simultaneous biaxial stretching, or multi-stage stretching is suitably adopted. The conditions for biaxial stretching may be the same as those for producing known biaxially stretched films, for example, in the case of a sequential biaxial stretching method, the longitudinal stretching temperature is 100°C to 145°C, the stretching ratio is in the range of 4 to 7 times, and the transverse stretching temperature is 150 to 190°C, and the stretching ratio is in the range of 8 to 11 times.

[0102] Base film If desired, the easy-open film of this embodiment can be laminated with a base film, preferably at its laminating layer (C).

[0103] There are no particular limitations on the base film, and for example, films that are normally used for plastic packaging can be suitably used. Preferred materials for the substrate film include plastic films made of thermoplastic resins such as polyolefins such as crystalline polypropylene, crystalline propylene-ethylene copolymer, crystalline polybutene-1, crystalline poly-4-methylpentene-1, low-, medium-, or high-density polyethylene, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA), and ionically crosslinked olefin copolymers (ionomers); aromatic vinyl copolymers such as polystyrene and styrene-butadiene copolymer; halogenated vinyl polymers such as polyvinyl chloride and vinylidene chloride resin; nitrile polymers such as acrylonitrile-styrene copolymer and acrylonitrile-styrene-butadiene copolymer; polyamides such as nylon 6, nylon 66, and para- or meta-xylylene adipamide; polyesters such as polyethylene terephthalate (PET) and polytetramethylene terephthalate; various polycarbonates; and polyacetals such as polyoxymethylene. Furthermore, if the contents to be packaged are oxygen-sensitive, the above film may be coated with a film vapor-deposited with a metal oxide or the like, or a film coated with an organic compound, or a layer made of ethylene vinyl alcohol copolymer (EVOH) resin. Plastic films made of these materials are used in an unstretched, uniaxially stretched, or biaxially stretched state.

[0104] As the base film, these plastic films can be used as a single layer or as a laminate of two or more types, and they can also be constructed by laminating one or two or more types of these plastic films with metal foil such as aluminum, paper, cellophane, etc. Preferred substrate films include, for example, single-layer films made of stretched nylon film or stretched polyester film, two-layer films made by laminating a polyolefin film such as low-density polyethylene or polypropylene with PET, and three-layer films made by laminating PET / nylon / polyethylene. When producing these laminated films, adhesives or anchoring agents can be interposed between the layers as needed. An ink layer for displaying a design can also be provided.

[0105] There are no particular limitations on the method for laminating the base material layer to the laminate layer (C), etc., but for example, the base material film can be directly laminated to the laminate layer (C) by extrusion lamination, etc. Alternatively, the base material film may be laminated to the laminate layer (C) via an adhesive by dry lamination, etc. As the adhesive, a conventional adhesive such as a urethane-based adhesive, an acid-modified polyolefin-based adhesive, a polyester-based adhesive, a polyether-based adhesive, or a polyamide-based adhesive can be used. The thickness of the substrate film can be set arbitrarily, but can usually be selected within the range of 7 to 500 μm, preferably 7 to 50 μm.

[0106] The laminated film obtained by laminating a substrate film to the laminate layer (C) of the easy-open film of this embodiment is preferably used in various applications, and is particularly suitable for use as a packaging material such as an easy-open film. A preferred example of such a packaging material is a lid material. That is, a laminated film obtained by laminating a base film on the laminate layer (C) of the easy-open film of the present embodiment can be used as a lid material for a container in which the heat-sealable layer (A) is used as the innermost layer on the container side, taking advantage of its easy-open properties, etc. When used as a container lid material, the heat-sealable film of the present invention may be used as the lid material as it is, or may be printed before use. Furthermore, it may be laminated to a printed or unprinted base film to form a lid material. Depending on the application, it may also be cut in advance to fit the shape of the container to form a lid material. When used as a container lid material, it is preferable to laminate it to a base film. By combining a lid material having the above-mentioned easy-open film with a container, an easy-open package can be formed.

[0107] In the easy-open film of the embodiment, a heat-sealable layer can be formed by heat-sealing the heat-sealable layer (A) to various adherends. Examples of such adherends include propylene polymers, polystyrene, polyester, polycarbonate, polyvinyl chloride, etc. These adherends can be in various shapes, such as films, sheets, trays, cups, and bottles. Among these, polyester is particularly preferred as the adherend because the heat-sealable layer has excellent sealing properties, easy opening properties, heat resistance, oil resistance, etc.

[0108] There are no particular restrictions on the items to be stored in the packaging container, but it can be preferably used for packaging foods, medicines, medical instruments, daily necessities, miscellaneous goods, etc. Taking advantage of the excellent visibility, anti-fogging properties, heat seal strength (easy opening), and low blocking properties of the heat-sealable film of the present invention, it is particularly suitable for use as a packaging container for prepared foods, salads, fruits, etc. [Example]

[0109] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples in any sense.

[0110] The physical properties and characteristics in the examples and comparative examples were evaluated by the following methods. (Reflective IR spectrum) The coating composition was applied to a 12 μm-thick polyethylene terephthalate film and dried by heating at 80° C. for 20 seconds to produce a sample with a coating of approximately 2 μm thickness after drying. The reflection IR spectrum of the coated surface was measured using an IRT-5200 device manufactured by JASCO Corporation under the following conditions. Measuring cell: Ge Incident angle: 45° Resolution: 4cm -1 Accumulation count: 100 times

[0111] (melting point peak) The endothermic peak in the second temperature rise of the coating composition was measured according to the usual melting point measurement method using DSC. The equipment and measurement conditions are shown below. Equipment: X-DSC7000 manufactured by SII (Seiko Instruments Inc.) First temperature rise: Raise the temperature from room temperature of 30°C to 150°C at a rate of 10°C / min. Hold: Hold at 150°C for 1 minute. Cooling: Cool down to -100°C at 10°C / min. Hold for 1 min. Second temperature increase: Increase the temperature to 150°C at a rate of 10°C / min and hold for 1 min.

[0112] (coating amount) The coating weight of the coating layer was evaluated by gravimetric measurement. The sample on which the coating layer was formed was cut into a 10cm x 10cm piece and its weight was measured. The coated surface was then cleaned using a Kimwipe dampened with ethanol. The weight of the sample after cleaning was measured, and the difference in weight before and after cleaning was taken as the coating amount. The weight difference was divided by the area to give the weight in g / m 2 Convert to units.

[0113] (Anti-fogging) 30 mL of purified water was placed in a transparent beaker, covered with the sample film with the measurement surface (coated surface) facing inward (water side), and stored in a refrigerator (set at approximately 5°C). After 24 hours of storage, the film was removed from the refrigerator and the degree of cloudiness of the film immediately after removal was visually observed and rated on a 5-point scale, with 5 points for no cloudiness and 1 point for cloudy and opaque. Figure 1(a) shows a schematic diagram of the evaluation criteria, and (b) shows a photograph of an actual anti-fogging evaluation example.

[0114] (Blocking strength) Two sample films were stacked with the coated and uncoated surfaces in contact, and stored at 40°C under a pressure of 4 kg for 24 hours. The peel strength (N / 5.2 cm) of the two sample films was then measured using a universal tensile tester (manufactured by A&D Co., Ltd.). 2 ) was measured.

[0115] (Heat seal strength) The coated side of the sample film was placed on an A-PET sheet (softening point 77°C, crystallization temperature 126°C) for heat-sealable substrate 1, and a PP sheet (main melting point 162.9°C, sub-melting point 107.5°C) for heat-sealable substrates 2 and 3. The sample was heat-sealed for 1.0 second using a precision heat sealer (Tester Sangyo) at temperatures between 120°C and 180°C, a pressure of 0.2 MPa, and a 5mm-wide seal bar. The sample was then allowed to cool. 15mm-wide test pieces were then cut from the heat-sealed samples and peeled off in an 180° direction using a universal tensile tester (A&D Co., Ltd.) at a tensile speed of 300mm / min in a constant temperature room at 23°C and 50% RH, and the maximum load was measured (unit: N / 15mm).

[0116] Details of the materials / components used in the examples / comparative examples are as follows: Heat-adhesive base material

[0117] ·Thermal adhesive base material 1 A three-layer laminated film with a thickness of 30 μm, consisting of a heat-sealing layer, an intermediate layer, and a laminate layer with thicknesses of 5.1 μm, 6.3 μm, and 18.6 μm, respectively, was used as the substrate film. The resins constituting each layer were as follows: Heat-sealed layer Polyethylene terephthalate resin (Tg: 73°C, density: 1340 kg / m 3 ) Middle class Polyolefin resin (MFR (2.16 kg 190°C): 5.6 g / 10 min, density: 903 kg / m 3 ) Laminate layer Polyethylene resin (MFR (2.16 kg 190°C): 3 g / 10 min, density: 928 kg / m 3 , melting point: 114℃)

[0118] ·Heat adhesive base material 2 A laminated film having a three-layer structure and a thickness of 30 μm, consisting of a heat-sealable layer / intermediate layer / laminate layer having thicknesses of 3.6 μm / 21.9 μm / 4.5 μm, respectively, was used as the heat-sealable substrate 2 . The resins constituting each layer were as follows: Heat-sealed layer Melt blend resin of ethylene copolymer + propylene random copolymer + tackifier Density: 925kg / m 3 Melting point: 123.1℃ (main), 143.0℃, 98.7℃, 85.2℃ (sub) Middle class Propylene homopolymer MFR(2.16kg230℃):7g / 10min Density: 910kg / m 3 Melting point: 161°C Laminate layer Linear low-density polyethylene MFR(2.16kg190℃):3.6g / 10min Density: 909kg / m 3 Melting point: 115℃

[0119] ·Thermal adhesive base material 3 A laminated film having a three-layer structure and a thickness of 30 μm, consisting of a heat-sealable layer / intermediate layer / laminate layer having thicknesses of 3.3 μm / 23.4 μm / 3.3 μm, respectively, was used as the heat-sealable substrate 3 . The resins constituting each layer were as follows: Heat-sealed layer Melt blend resin of ethylene copolymer + propylene random copolymer + tackifier Density: 920kg / m 3 Melting point: 126.2℃ (main) 142.6℃ (sub) ℃ Middle class The same resin as that used for the heat-sealing layer was used. Laminate layer Propylene random copolymer MFR(2.16kg230℃):7.3g / 10min Density: 910kg / m 3 Melting point: 143°C

[0120] Polymer surfactants An acrylic polymer surfactant 1 (aqueous solution with a 15% solid content, an acrylic polymer containing a quaternary ammonium salt, a molecular weight of approximately 26,000, an acid value of 1.0, and a melting point of 118° C.) was used.

[0121] low molecular weight surfactants A low molecular weight surfactant 1 (diglycerin monolaurate, molecular weight: 349) was used.

[0122] Preparation and evaluation of coating compositions (Comparative Example 1) Low molecular weight surfactant 1 was dispersed in a solvent (a mixed solvent of isopropanol and water) to prepare a coating composition with a concentration of 2% by mass. The reflective IR spectrum and melting point peak of the coating composition were evaluated according to the above-mentioned methods, and the results are shown in Table 1.

[0123] (Examples 1 to 4) Low molecular weight surfactant 1 and polymeric surfactant 1 were mixed in the mass ratio shown in Table 1 and dispersed in a solvent (a mixed solvent of isopropanol and water) to prepare a coating composition with a concentration of 2 mass %. The reflective IR spectrum and melting point peak of the coating composition were evaluated according to the above-mentioned methods, and the results are shown in Table 1. [Table 1]

[0124] Coating Application and Evaluation (Blank 1) For comparison, the heat-fusible substrate 1 that had not been coated was evaluated for anti-fogging properties, blocking strength, and heat seal strength according to the above methods. The results are shown in Table 2. Because no coating was applied, the anti-fogging properties were poor.

[0125] (Comparative Test 1-1) The coating composition of Comparative Example 1 was applied to the heat-sealable layer side of the heat-sealable substrate 1 using a bar coater, and dried for 1 minute in a thermostatic chamber adjusted to 80°C to obtain a film in which a coating layer was formed on the heat-sealable layer of the heat-sealable substrate 1. The coating amount was calculated from the mass after drying and was found to be 0.2 g / m 2 It was. The obtained film was evaluated for anti-fogging property, blocking strength, and heat seal strength according to the methods described above. The results are shown in Table 2. The anti-fogging properties were excellent and the heat seal strength was adequate, but blocking occurred.

[0126] (Tests 1-1 to 1-8, Comparative Test 1-2) The coating compositions of Examples 1 to 3 and Comparative Example 2 shown in Table 1 were applied to the heat-sealable layer side of the heat-sealable substrate 1 using a bar coater so as to obtain the coating amounts shown in Table 1, and then dried for 1 minute in a thermostatic oven adjusted to 80°C to obtain a film in which a coating layer was formed on the heat-sealable layer of the substrate film. The obtained film was evaluated for anti-fogging property, blocking strength, and heat seal strength according to the methods described above. The results are shown in Table 2. When the coating composition of each Example was used, the anti-fogging property, heat sealability, and blocking resistance were all good. When the coating composition of Comparative Example 2 was used, the heat seal strength was insufficient. [Table 2]

[0127] (Blank 2) For comparison, the anti-fogging property and blocking strength of the uncoated heat-sealable substrate 2 were evaluated according to the above methods. The results are shown in Table 3. Because no coating was applied, the anti-fogging properties were poor.

[0128] (Comparative Test 2-1) The coating composition of Comparative Example 1 was applied to the heat-sealable layer side of the heat-sealable substrate 2 using a bar coater, and dried for 1 minute in a thermostatic chamber adjusted to 80°C to obtain a film in which a coating layer was formed on the heat-sealable layer of the heat-sealable substrate 2. The coating amount was calculated from the mass after drying and was found to be 0.050 g / m 2 It was. The anti-fogging properties and blocking strength of the obtained film were evaluated according to the methods described above, and the results are shown in Table 3. In comparison with any of Test Examples 2-1 to 2-4 described later, at least one of the anti-fogging property and the blocking resistance was inferior.

[0129] (Tests 2-1 to 2-3, Comparative Test 2-2) A film in which a coating layer was formed on the heat-fusible layer of the heat-fusible substrate 2 was obtained in the same manner as in Comparative Test 2-1, except that the coating composition of Comparative Example 1 was changed to the coating compositions of Examples 1 to 3 and Comparative Example 2 shown in Table 3. The coating amount was calculated from the mass after drying and was found to be 0.050 g / m 2 It was. The anti-fogging properties and blocking strength of the obtained film were evaluated according to the methods described above, and the results are shown in Table 3. When the coating composition of each Example was used, the balance of anti-fogging property, heat sealability, and blocking resistance was excellent compared to Comparative Test 2-1. When the coating composition of Comparative Example 2 was used, the anti-fogging property was insufficient. [Table 3]

[0130] (Blank 3) For comparison, the anti-fogging property and blocking strength of the uncoated heat-fusible substrate 3 were evaluated according to the above methods. The results are shown in Table 4. Because no coating was applied, the anti-fogging properties were poor.

[0131] (Tests 3-1 and 3-2) The coating composition of Example 2 was applied to the heat-sealable layer side of the heat-sealable substrate 3 using a bar coater so as to obtain the coating amount shown in Table 4, and the coating was dried for 1 minute in a thermostatic oven adjusted to 80°C, thereby obtaining a film in which a coating layer was formed on the heat-sealable layer of the heat-sealable substrate 1. The anti-fogging properties and blocking strength of the obtained film were evaluated according to the methods described above, and the results are shown in Table 4. The film had an excellent balance of anti-fogging properties, heat sealing properties, and blocking resistance. [Table 4] [Industrial Applicability]

[0132] The coating composition of the present invention can form a coating layer that combines highly practically valuable properties, such as anti-fogging properties, heat seal strength (easy opening), and low blocking properties, at a level that exceeds the limits of conventional technology.The coating composition of the present invention can be suitably used in a variety of applications, including as a lid material for easy-open plastic containers that store various products, such as food, that require visibility of the contents, and has high applicability in various fields of industries such as food processing, distribution, retail, and restaurant services.

Claims

1. A composition comprising (a) a low molecular weight surfactant and (b) a polymeric surfactant, In the reflection IR spectrum measurement, 1730 cm －１ ±30cm －１ The absorption peak height (P2) is 1560 ± 30 cm －１ the ratio (P4 / P2) of the absorption peak height (P4) is 0.08 or more and 1.80 or less, A coating composition having a ratio (P3 / P2) of an absorption peak height (P2) at 1730 cm −1 ±30 cm −1 to an absorption peak height (P3) at 1630 cm −1 ±30 cm −1 of 0.03 or more and 0.60 or less.

2. In the reflection IR spectrum measurement, 1730 cm －１ ±30cm －１ The absorption peak height (P2) is 3400 ± 30 cm －１ 2. The coating composition according to claim 1, wherein the ratio (P1 / P2) of the absorption peak height (P1) to the absorption peak height (P2) is 0.10 or more and 0.58 or less.

3. 3. The coating composition according to claim 1, which has a melting point peak at 35±25°C in DSC measurement.

4. The coating composition according to claim 3, further having melting point peaks at 15.3±5°C and 118±15°C in DSC measurement.

5. The coating composition of claim 1 , wherein (a) the low molecular weight surfactant comprises a nonionic surfactant.

6. The coating composition according to claim 1 or 5, wherein the polymer surfactant (b) comprises an acrylic surfactant.

7. 7. An easily openable film comprising a heat-sealable layer (A), an intermediate layer (B), and a laminate layer (C) laminated in this order, and having a coating layer formed from the coating composition according to claim 1 on the heat-sealable layer (A).

8. The easy-open film according to claim 7, wherein the heat-sealable layer (A) contains at least one of polyethylene terephthalate, an ethylene-based (co)polymer, and a propylene-based (co)polymer.

9. An easy-open package comprising a lid material having the easy-open film according to claim 7 or 8, and a container.

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