Emulsion compositions for coatings, coating films, and heat-shrinkable films

Abstract

To provide an emulsion composition for coating, capable of forming a coating film that has a low coefficient of kinetic friction, excellent abrasion resistance, and can reduce the occurrence of static electricity (antistatic properties).SOLUTION: An emulsion composition for coating comprises a matrix resin that comprises a neutralization reactant of an acrylic polymer comprising an acid radical and an amine, a wax lubricant, and water. The emulsion composition is applied onto a coated target such as a substrate film, followed by heating and drying, which can easily form a coating film having excellent wear resistance and antistatic properties.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an emulsion composition for coating, a coating film, and a heat-shrinkable film.

Background Art

[0002] Conventionally, synthetic resin containers such as polyethylene terephthalate have been used as containers for storing soft drinks and the like. A label formed from a heat-shrinkable film made of a synthetic resin such as polyethylene terephthalate is attached to the outer peripheral surface of the container.

[0003] This heat-shrinkable film has a problem in that its abrasion resistance is low, and the surface of the label may be worn or torn due to the impact during transportation.

[0004] Therefore, in order to prevent abrasion and tearing of the label, a coating composition containing a wax-based lubricant is applied to the label surface to reduce the frictional resistance of the label surface.

[0005] As such a coating composition containing a wax-based lubricant, Patent Document 1 discloses an aqueous resin emulsion for plastic coating containing an emulsion obtained by polymerizing an ethylenically unsaturated monomer (A) with a water-soluble polyester or a water-dispersible polyester as a protective colloid and a lubricant (B).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the above-mentioned aqueous resin emulsion for plastic coating has the problem of easily generating static electricity and becoming charged, which can cause poor runability during label processing or in processed products using the labels, and attract dust and other debris to the label surface, resulting in poor quality of the labels and processed products.

[0008] The present invention provides a coating emulsion composition that can form a coating film having a low coefficient of dynamic friction, excellent wear resistance, and the ability to reduce the generation of static electricity (antistatic properties). [Means for solving the problem]

[0009] The coating emulsion composition of the present invention contains a matrix resin containing a neutralization reaction product of an acrylic polymer containing acid groups and amines, a wax-based lubricant, and water.

[0010] [A matrix resin containing a neutralization reaction product of an acrylic polymer containing acid groups and amines] The coating emulsion composition of the present invention contains a matrix resin comprising a neutralization reaction product of an acrylic polymer (A) containing acid groups and amines. The inclusion of a neutralization reaction product between the acrylic polymer (A) containing acid groups and amines imparts excellent hydrophilicity (water absorption) to the coating film formed from the coating emulsion composition (hereinafter sometimes simply referred to as the "coating film"). Therefore, the coating film has excellent electrical conductivity due to the high electrical conductivity of moisture, and even if the coating film becomes charged, the charge can be attenuated, resulting in excellent antistatic properties. In this invention, "antistatic properties" are intended to include not only complete prevention of charging but also reduction of charging.

[0011] In the matrix resin, the content of the neutralization reaction product between the acrylic polymer (A) containing acid groups and amines is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. In the matrix resin, the content of the neutralization reaction product between the acrylic polymer (A) containing acid groups and amines is preferably 95% by mass or less, and more preferably 90% by mass or less. When the content of the neutralization reaction product between the acrylic polymer (A) containing acid groups and amines is 60% by mass or more, the antistatic properties of the coating film are improved. When the content of the neutralization reaction product between the acrylic polymer (A) containing acid groups and amines is 60% by mass or more, the mechanical strength of the coating film is improved.

[0012] Acrylic polymer (A) containing acid groups has a polymer containing acrylic monomer units as its main chain, and acid groups as side chains on this main chain. In this invention, "main chain" refers to the longest molecular chain in the molecule, and the length of the molecular chain is determined by the number of atoms that make up the molecular chain; the more atoms there are, the longer the molecular chain is considered to be.

[0013] The acrylic monomers are not particularly limited and include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate [dodecyl (meth)acrylate], and stearyl. Examples include alkyl(meth)acrylates such as (meth)acrylate; alicyclic(meth)acrylates such as cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, dicyclopentanyl(meth)acrylate, and adamantanyl(meth)acrylate; nitrogen-containing(meth)acrylic monomers such as (meth)acrylonitrile, (meth)acrylamide, and diacetone(meth)acrylamide; acrylic acid; and methacrylic acid. Note that (meth)acrylate means acrylate or methacrylate. (Meth)acrylic means acrylic or methacrylic. Acrylic monomers may be used alone or in combination of two or more.

[0014] The acrylic polymer (A) containing an acid group preferably contains (meth)acrylic acid units and (meth)acrylate units, more preferably contains (meth)acrylic acid units and alkyl (meth)acrylate units, and even more preferably contains methacrylic acid units and alkyl (meth)acrylate units.

[0015] The content of acrylic monomer units in the acrylic polymer (A) containing acid groups is preferably 50% by mass or more, more preferably 60% by mass or more, and more preferably 70% by mass or more, as it suppresses the occurrence of cracks in the coating film when stress such as tensile stress is applied to the coating film, maintains a low coefficient of dynamic friction of the coating film, and maintains excellent wear resistance. The content of acrylic monomer units in the acrylic polymer (A) containing acid groups is preferably 90% by mass or less, and more preferably 85% by mass or less, as it improves the film-forming properties of the coating emulsion composition, improves the surface smoothness of the coating film, maintains a low coefficient of dynamic friction of the coating film, and maintains excellent wear resistance.

[0016] The number of carbon atoms in the alkyl(meth)acrylate alkyl group is preferably 4 or more, more preferably 5 or more, and more preferably 6 or more, as it can improve the water resistance of the coating film while maintaining the antistatic properties of the coating film. The number of carbon atoms in the alkyl(meth)acrylate alkyl group is preferably 15 or less, more preferably 12 or less, and more preferably 10 or less, as it improves the dispersion stability of the coating emulsion composition.

[0017] The alkyl (meth)acrylate preferably contains 2-ethylhexyl (meth)acrylate, more preferably contains 2-ethylhexyl acrylate or 2-ethylhexyl methacrylate, and even more preferably contains 2-ethylhexyl acrylate and 2-ethylhexyl methacrylate.

[0018] The total content of alkyl (meth)acrylate units in the acrylic polymer (A) containing acid groups is preferably 30% by mass or more, and more preferably 40% by mass or more, as this improves the abrasion resistance and water resistance of the coating film. The total content of alkyl (meth)acrylate units in the acrylic polymer (A) containing acid groups is preferably 60% by mass or less, more preferably 55% by mass or less, more preferably 50% by mass or less, and more preferably 45% by mass or less, as this improves the dispersion stability of the coating emulsion composition.

[0019] Since the total content of (meth)acrylic acid units in the acrylic polymer (A) containing an acid group improves the dispersion stability of the coating emulsion composition, it is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more. Since the total content of (meth)acrylic acid units in the acrylic polymer (A) containing an acid group can improve the water resistance of the coating film while maintaining the antistatic property of the coating film, it is preferably 50% by mass or less, and more preferably 45% by mass or less.

[0020] The acrylic polymer (A) containing an acid group preferably contains a styrene monomer unit. When the acrylic polymer (A) containing an acid group contains a styrene unit, the adhesion to the base film is improved, which is preferable. In particular, when a coating film formed from the coating emulsion composition is laminated and integrated on a heat-shrinkable base film to form a heat-shrinkable film, even after the heat-shrinkable film is heat-shrunk, the coating film can be stably adhered and laminated integrally on the heat-shrinkable base film.

[0021] Examples of the styrene monomer include styrene, α-methylstyrene, p-methylstyrene, methylstyrene, tert-butylstyrene, chlorostyrene, vinyltoluene, etc. Styrene is preferable because the adhesion to the heat-shrinkable base film is improved. The styrene monomer may be used alone or in combination of two or more.

[0022] Since the content of the styrene monomer unit in the acrylic polymer improves the adhesion to the heat-shrinkable base film, it is preferably 10% by mass or more, and more preferably 15% by mass or more. Since the content of the styrene monomer unit in the acrylic polymer improves the flexibility of the coating film and the adhesion to the base film, it is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0023] In the acrylic polymer (A) having an acid group, the acid group is not particularly limited, and examples thereof include a carboxy group (-COOH), a sulfonic acid group (-SO3H), a phosphoric acid group (-PO4H2), etc., and a carboxy group is preferred.

[0024] The acrylic polymer (A) containing an acid group preferably contains a monomer unit containing an acid group, preferably contains an ethylenically unsaturated bond-containing monomer unit containing an acid group, and more preferably contains an ethylenically unsaturated double bond-containing monomer unit containing an acid group.

[0025] The monomer unit containing an acid group is not particularly limited, and examples thereof include carboxy group-containing acrylic monomers such as acrylic acid, methacrylic acid, β-carboxyethyl acrylate, β-carboxyethyl methacrylate, etc., carboxy group-containing monomers such as itaconic acid, crotonic acid, maleic acid, fumaric acid, (anhydrous) maleic acid, (anhydrous) citraconic acid, etc.; sulfonic acid group-containing acrylate monomers such as sulfoethyl acrylate, sulfoethyl methacrylate, sulfopropyl acrylate, sulfopropyl methacrylate, sulfobutyl acrylate, sulfobutyl methacrylate, 3-acryloxy-2-hydroxypropanesulfonic acid, 3-methacryloxy-2-hydroxypropanesulfonic acid, 3-acryloxy-1-hydroxypropane-2-sulfonic acid, 3-methacryloxy-1-hydroxypropane-2-sulfonic acid, etc.; phosphoric acid group-containing acrylate monomers such as acid phosphooxyethyl acrylate, acid phosphooxyethyl methacrylate, mono(2-hydroxyethyl acrylate) phosphate, mono(2-hydroxyethyl methacrylate) phosphate, etc., and ethylenically unsaturated double bond-containing monomers containing an acid group. As the monomer containing an acid group, a carboxy group-containing acrylic monomer is preferred, (meth)acrylic acid is more preferred, and methacrylic acid is more preferred.

[0026] In the acrylic polymer (A) containing acid groups, the content of monomer units containing acid groups is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more, as this improves the antistatic properties of the coating film. The content of (meth)acrylic acid units in the acrylic polymer (A) containing acid groups is preferably 50% by mass or less, and more preferably 45% by mass or less, as this improves adhesion to the heat-shrinkable substrate film.

[0027] As a method for producing an acrylic polymer (A) containing acid groups, known methods can be used. For example, (1) a method for producing an acrylic polymer (A) containing acid groups (carboxyl groups) by suspension polymerization in water of a monomer composition containing a carboxyl group-containing monomer and an acrylic monomer, preferably a styrene monomer, in a known manner; and (2) a method for producing an acrylic polymer (A) containing acid groups (sulfonic acid groups) by suspension polymerization in water of a monomer composition containing a sulfonic acid group-containing monomer and an acrylic monomer, preferably a styrene monomer, in a known manner. In addition, acid groups such as carboxyl groups and sulfonic acid groups may be introduced into the acrylic polymer in a general manner. The water used for suspension polymerization may, if necessary, contain alcohol (methanol, ethanol, propyl alcohol, etc.).

[0028] The coating emulsion composition contains a neutralization reaction product of an acrylic polymer (A) containing acid groups and amines. That is, the acrylic polymer (A) containing acid groups forms a neutralization reaction product through a neutralization reaction with amines at some or all of its acid groups. The amines only need to have an amino functional group in their molecule that can react with the acid groups of the acrylic polymer (A), and they form a salt with the acid groups of the acrylic polymer (A), thereby imparting antistatic properties to the coating film produced from the coating emulsion composition and reducing the generation of static electricity on the coating film. The amino functional group includes 1- to 3-valent nitrogen-containing substituents of -NH2, =NH [formula (1)], and ≡N [formula (2)].

[0029] [ka]

[0030] The amines are not particularly limited and include, for example, monoethanolamine, aminoethylethanolamine, monoisopropanolamine, N-(2-hydroxypropyl)-ethylenediamine, 2-amino-1-butanol, 2-amino-2-methyl-1-propanol, 3-amino-1-propanol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, tris(hydroxyethyl)-aminomethane, and other primary alkanolamines; diethanolamine, methylethanolamine, b Examples include secondary alkanolamines such as ethylmethanolamine, N-acetylethanolamine, and diisopropanolamine; tertiary alkanolamines such as triethanolamine, methyldiethanolamine, dimethylethanolamine, diethylethanolamine, ethyldiethanolamine, and triisopropanolamine; primary alkylamines such as methylamine, ethylamine, isobutylamine, t-butylamine, and cyclohexylamine; secondary alkylamines such as dimethylamine, diethylamine, and diisopropylamine; and tertiary alkylamines such as trimethylamine. These amines may be used individually or in combination of two or more.

[0031] The amines preferably contain alkanolamines, and more preferably contain tertiary alkanolamines. The alkanolamine content in the amines is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and more preferably 100% by mass.

[0032] Amines are 1.013 × 10 3It is preferable to include amines with a boiling point (hereinafter sometimes simply referred to as "boiling point") of 300°C or higher at hPa (1 atmosphere). Examples of amines with a boiling point of 300°C or higher include triethanolamine (335°C) and triisopropanolamine (305°C). 1.013 × 10 of the amines 3 The boiling point at hPa (1 atmosphere) is preferably 500°C or lower.

[0033] In the process of producing a coating film from a coating emulsion composition, the coating emulsion composition is heated and dried. Meanwhile, the neutralization reaction products in the coating emulsion composition are salts formed by the electrical attraction between the acid groups of the acrylic polymer (A) and amines. When the coating emulsion composition is heated and dried, the thermal energy applied causes some of the salts between the acid groups of the acrylic polymer (A) and amines to decompose, releasing the amines. Amines with a boiling point below 300°C may volatilize outside the coating emulsion composition once released. As a result, the amount of neutralization reaction products between the acrylic polymer (A) containing acid groups and amines in the coating emulsion composition and the coating film produced from it may decrease, potentially reducing the antistatic properties of the coating film.

[0034] On the other hand, in the case of a neutralization reaction product between amines with a boiling point of 300°C or higher and an acrylic polymer containing acid groups, even if the neutralization reaction product decomposes during the heating and drying process of the coating emulsion composition and the amines are released into the coating emulsion composition, the volatilization of the amines outside the coating emulsion composition is reduced, and they remain in the coating emulsion composition. The coating film produced from this coating emulsion composition contains a sufficient amount of the neutralization reaction product between the acrylic polymer (A) containing acid groups and the amines, and has excellent antistatic properties.

[0035] The acrylic polymer (A) containing acid groups may have some of its acid groups neutralized with ammonia to form a neutralization product. That is, the neutralization product may be a neutralization product produced by the neutralization reaction of the acrylic polymer (A) containing acid groups with amines and ammonia. When the neutralization product includes the neutralization product of the acrylic polymer (A) containing acid groups with amines and ammonia, the dispersibility of the matrix resin in the coating emulsion composition is improved. Because the matrix resin is dispersed substantially uniformly in the coating emulsion composition, the coating film produced from the coating emulsion composition has the wax-based lubricant described later uniformly dispersed in the matrix resin, and has excellent antistatic and abrasion-resistant properties.

[0036] The glass transition temperature Tg of the neutralization reaction product of an acrylic polymer (A) containing acid groups and amines is preferably -10°C or higher, and more preferably -5°C or higher. The glass transition temperature Tg of the neutralization reaction product of an acrylic polymer (A) containing acid groups and amines is preferably 45°C or lower, more preferably 40°C or lower, more preferably 35°C or lower, and more preferably 30°C or lower. In this invention, the glass transition temperature Tga of the polymer is the temperature calculated based on Fox's formula. Specifically, when the polymer is composed of n types of monomer units M1, M2...Mn, the glass transition temperatures Tg [K (Kelvin)] of the homopolymers of each monomer unit M1, M2...Mn are Tg1 and Tg2...Tgn, respectively, and the content (content ratio) of each monomer unit M1, M2...Mn is C1 and C2...Cn, respectively, the glass transition temperature Tga of the polymer is expressed by the following Fox formula. However, C1 + C2 + ... + Cn = 1.

[0037]

number

[0038] As described above, the coating emulsion composition contains a neutralization reaction product between an acrylic polymer (A) containing acid groups and amines, but it may also contain amines that exist in a free state without undergoing a neutralization reaction with the acrylic polymer (A) containing acid groups.

[0039] When a coating emulsion composition contains an acrylic polymer (A) containing acid groups and a neutralization reaction product of amines and ammonia, it may also contain amines and ammonia that exist in a free state without undergoing a neutralization reaction with the acrylic polymer (A) containing acid groups.

[0040] The content of amines with a boiling point of 300°C or higher in the amines is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, and more preferably 100% by mass.

[0041] In a coating emulsion composition, the ratio of the total number of moles of amino functional groups in amines that form a neutralization reaction product with an acrylic polymer containing acid groups and amines that exist in a free state and are capable of reacting with the acid groups of the acrylic polymer (A) (hereinafter sometimes simply referred to as "total number of moles of amino functional groups of amines") to the total number of moles of acid groups that form a neutralization reaction product in the acrylic polymer (A) (acid groups undergoing neutralization) and free acid groups (total number of moles of amino functional groups / total number of moles of acid groups) (hereinafter sometimes referred to as "moles of amino functional groups / molar ratio of acid groups") is preferably 0.5 or higher, more preferably 0.6 or higher, and even more preferably 0.7 or higher. When the "moles of amino functional groups / molar ratio of acid groups" is 0.5 or higher, the antistatic properties of the coating film are improved.

[0042] In a coating emulsion composition, the ratio of the total number of moles of amino functional groups (hereinafter sometimes simply referred to as "total number of moles of amino functional groups of amines") that are reactable with the acid groups of the acrylic polymer (A) and have amines that are in a free state, to the total number of moles of acid groups (total number of moles of amino functional groups / total number of moles of acid groups) that are reacting with the acid groups of the acrylic polymer (A) and have amines that are in a free state, is preferably 1.5 or less, more preferably 1.25 or less, and most preferably 1.0 or less. When the "amino functional group mole / acid group mole ratio" is 1.5 or less, the water resistance of the coating film can be improved while maintaining the antistatic properties of the coating film.

[0043] When the neutralization reaction product contained in the coating emulsion composition includes a neutralization reaction product of an acrylic polymer (A) containing acid groups, amines, and ammonia, the ratio of the total number of moles of amino functional groups in the coating emulsion composition that are reactable with the acid groups of the acrylic polymer (A) and the amines present in a free state, to the total number of moles of ammonia contained in the coating emulsion composition (total number of moles of amino functional groups of amines / total number of moles of ammonia) (hereinafter sometimes referred to as the "amino functional group mole / ammonia molar ratio") is preferably 0.25 or higher, more preferably 0.5 or higher, more preferably 0.8 or higher, and more preferably 1.0 or higher. When the "amino functional group mole / ammonia molar ratio" is 0.25 or higher, the antistatic properties of the coating film are improved.

[0044] When the neutralization reaction product contained in the coating emulsion composition includes a neutralization reaction product of an acrylic polymer (A) containing acid groups, amines, and ammonia, the ratio of the total number of moles of amino functional groups that can react with the acid groups of the acrylic polymer (A) and the amines that are in a free state to the total number of moles of ammonia contained in the coating emulsion composition (total number of moles of amino functional groups of amines / total number of moles of ammonia) is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less. When the "amino functional group mole / ammonia mole ratio" is 2.0 or less, the dispersibility of the matrix resin in the coating emulsion composition is improved, and the coating film has excellent antistatic and abrasion resistance, with the wax-based lubricant described later uniformly dispersed in the matrix resin.

[0045] Furthermore, when calculating the "moles of amino functional groups / moles of acid groups" and the "moles of amino functional groups / moles of ammonia," if an amine has multiple amino functional groups (n groups, where n is a natural number greater than or equal to 2) that can react with the acid groups of the acrylic polymer (A), the number of moles of amino functional groups in the amine is calculated as multiple times (n times) the number of moles of the amine.

[0046] The method for producing a neutralization reaction product of an acrylic polymer (A) containing acid groups and amines is not particularly limited. For example, one method involves supplying amines to water in which the acrylic polymer (A) containing acid groups is dispersed, maintaining the temperature at a predetermined level, and neutralizing the acid groups of the acrylic polymer (A) with the amines.

[0047] The matrix resin may contain polymers that can constitute the matrix of the coating film, in addition to the neutralization reaction product of an acrylic polymer (A) containing acid groups and amines. Examples of such polymers include polymers that do not have acid groups. Polymers that do not have acid groups are not particularly limited and include, for example, acrylic resins, polyester resins, and styrene resins that do not have acid groups, with acrylic resins that do not have acid groups being preferred. The polymers may be used individually or in combination of two or more.

[0048] As the above-mentioned acrylic resin (B) that does not have an acid group, a polymer containing acrylic monomer units that do not have an acid group is preferred. The acrylic monomer that does not have an acid group is not particularly limited, and for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate [dodecyl (meth)acrylate Examples include alkyl(meth)acrylates such as stearyl(meth)acrylate; alicyclic(meth)acrylates such as cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, dicyclopentanyl(meth)acrylate, and adamantanyl(meth)acrylate; and nitrogen-containing(meth)acrylic monomers such as (meth)acrylonitrile, (meth)acrylamide, and diacetone(meth)acrylamide. Acrylic monomers without acid groups may be used alone or in combination of two or more.

[0049] In the acrylic resin (B) that does not have acid groups, the content of acrylic monomer units that do not have acid groups is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 100% by mass.

[0050] Acrylic resin (B) without acid groups may contain monomer units without acid groups that can copolymerize with acrylic monomers without acid groups. Such monomer units without acid groups are not particularly limited and include, for example, the styrene monomers mentioned above.

[0051] In the above, the matrix resin was described as comprising a neutralization reaction product of an acrylic polymer (A) containing acid groups and amines, and optionally a polymer without acid groups. However, the matrix resin is preferably particulate, more preferably a core-shell type particle comprising a core portion and a shell portion covering the core portion, more preferably a core-shell type particle in which the neutralization reaction product of an acrylic polymer (A) containing acid groups and amines constitutes the shell portion, and more preferably a core-shell type particle in which a polymer without acid groups constitutes the core portion and the neutralization reaction product of an acrylic polymer (A) containing acid groups and amines constitutes the shell portion.

[0052] When the matrix resin is in the form of particles, during the application of the coating emulsion composition, the wax-based lubricant is interposed between the matrix resin particles. In this state, the matrix resin melts and forms a coating film, allowing for the formation of a coating film with the wax-based lubricant dispersed almost uniformly, and enabling the wax-based lubricant to be exposed as much as possible on the surface of this coating film. Therefore, the resulting coating film has excellent abrasion resistance and antistatic properties.

[0053] The average particle diameter of the matrix resin particles is preferably 50 nm or more, and more preferably 80 nm or more. The average particle diameter of the matrix resin particles is preferably 1000 nm or less, more preferably 500 nm or less, more preferably 400 nm or less, more preferably 300 nm or less, more preferably 200 nm or less, and more preferably 150 nm or less. When the average particle diameter of the matrix resin particles is 50 nm or more, the water resistance of the coating film can be improved while maintaining the antistatic properties of the coating film. When the average particle diameter of the matrix resin particles is 1000 nm or less, the film-forming properties of the coating emulsion composition are improved, the surface smoothness of the coating film is improved, and the dynamic friction coefficient of the coating film can be kept low, thus maintaining excellent abrasion resistance. The average particle diameter of the matrix resin particles refers to the particle diameter D50 at which the cumulative frequency from the smallest particle diameter in the volume-based particle size distribution measured by laser diffraction is 50% by mass. The average particle size of the matrix resin particles can be measured using a measuring device, for example, one commercially available from Horiba, Ltd. under the product name "Laser Diffraction / Scattering Particle Size Distribution Analyzer LA-950V2".

[0054] The matrix resin particles are preferably core-shell type particles, and it is more preferable that the shell portion is composed of a neutralization reaction product of an acrylic polymer (A) containing acid groups and amines. In core-shell type particles, if the shell portion is composed of a neutralization reaction product of an acrylic polymer (A) containing acid groups and amines, the surface area of ​​the neutralization reaction product of the acrylic polymer (A) containing acid groups and amines on the core portion can be increased, improving the hydrophilicity of the coating film and improving the antistatic properties of the coating film.

[0055] The glass transition temperature Tg of the polymer constituting the shell portion in the core-shell type matrix resin particles is preferably -10°C or higher, and more preferably -5°C or higher. The glass transition temperature Tg of the polymer constituting the shell portion in the core-shell type matrix resin particles is preferably 45°C or lower, more preferably 40°C or lower, more preferably 35°C or lower, and more preferably 30°C or lower. When the glass transition temperature Tg of the polymer constituting the shell portion in the core-shell type matrix resin particles is within the above range, the matrix resin can be melted to form a coating film with a good interposition of the wax-based lubricant between the matrix resin particles, and a coating film can be produced with the wax-based lubricant dispersed substantially uniformly. Therefore, the resulting coating film has excellent abrasion resistance and antistatic properties.

[0056] The method for producing core-shell type matrix resin particles is not particularly limited, and for example, they may be produced in the following manner.

[0057] For example, a monomer composition containing an acrylic monomer and a monomer containing an acid group is polymerized in water to produce an acrylic polymer (A) containing an acid group. Then, the acid group of this acrylic polymer (A) is neutralized with an amine to produce a neutralization reaction product of the acrylic polymer (A) containing an acid group and the amine, which constitutes the shell portion. Next, in the presence of the obtained neutralization reaction product, monomers constituting the core portion are polymerized in water to generate the core portion, and the surface of this core portion is coated with the shell portion to produce particles of a core-shell type matrix resin.

[0058] [Wax-based lubricant] The coating emulsion composition contains a wax-based lubricant. The presence of the wax-based lubricant on the surface of the resulting coating film reduces the coefficient of dynamic friction of the coating film, thereby providing the coating film with excellent wear resistance. Furthermore, reducing the coefficient of dynamic friction of the coating film reduces the frictional force generated on the surface of the coating film, thereby reducing static charge on the coating film.

[0059] The wax-based lubricant is not particularly limited and includes, for example, polyethylene wax, polypropylene wax, their oxides, modified derivatives thereof with carboxyl groups, paraffin wax, microcrystalline wax, carnauba wax, etc., dispersed in water, or self-emulsifying or emulsion-type waxes forcibly emulsified with emulsifiers.

[0060] The wax-based lubricant is preferably in particulate form. When the wax-based lubricant is in particulate form, it can be scattered on the surface of the coating film at appropriate intervals, exposing the wax-based lubricant, thereby creating appropriate slipperiness on the coating film, reducing the coefficient of dynamic friction on the surface of the coating film, and providing the coating film with excellent wear resistance.

[0061] On the other hand, the coefficient of dynamic friction on the surface of the coating film is reduced to an extent that does not reduce it too much, but rather to an extent that provides wear resistance. Therefore, in subsequent processes such as the processing, transport, and use of the film on which the coating film is formed, an appropriate amount of friction is generated on the surface of the coating film, allowing the subsequent processes of the film to be carried out smoothly without any problems.

[0062] The average particle size of the wax-based lubricant is preferably 0.01 μm or more, more preferably 0.05 μm or more, more preferably 0.1 μm or more, and more preferably 0.15 μm or more. The average particle size of the wax-based lubricant is preferably 0.5 μm or less, more preferably 0.4 μm or less, more preferably 0.3 μm or less, and more preferably 0.2 μm or less. When the average particle size of the wax-based lubricant is 0.01 μm or more, the wax-based lubricant can be appropriately exposed on the surface of the coating film, reducing the dynamic friction coefficient of the coating film and improving wear resistance. When the average particle size of the wax-based lubricant is 0.5 μm or less, the wax-based lubricant can be appropriately finely dispersed on the surface of the coating film, reducing the dynamic friction coefficient of the coating film and improving wear resistance. The average particle size of the wax-based lubricant refers to the particle size D50 at which the cumulative frequency from the smallest particle size in the volume-based particle size distribution measured by laser diffraction is 50% by mass.

[0063] In a coating emulsion composition, the ratio of the matrix resin content to the wax-based lubricant content (parts by mass of matrix resin / parts by mass of wax-based lubricant) is preferably 1 or more, more preferably 3 or more, and even more preferably 5 or more. The ratio of the matrix resin content to the wax-based lubricant content (parts by mass of matrix resin / parts by mass of wax-based lubricant) is preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less. When the ratio of the matrix resin content to the wax-based lubricant content (parts by mass of matrix resin / parts by mass of wax-based lubricant) is within the above range, the coating film has excellent abrasion resistance and antistatic properties.

[0064] In addition to the matrix resin and wax-based lubricant, the coating emulsion composition may also contain additives such as film-forming aids, provided that these additives do not impair the effectiveness of the coating emulsion composition.

[0065] The film-forming aid is not particularly limited and includes, for example, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and n-propyl alcohol; polyhydric alcohols such as propylene glycol and glycerin; ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, and ethyl carbitol; and cellosolve-based solvents such as methyl cellosolve, ether cellosolve, propyl cellosolve, butyl cellosolve, and butyl cellosolve acetate. The film-forming aid may be used alone or in combination of two or more types.

[0066] As film-forming aids, ethers and cellosolve-based solvents are preferred due to their excellent film-forming properties, with propylene glycol monomethyl ether, butyl cellosolve, and butyl cellosolve acetate being more preferred.

[0067] The content of the film-forming aid in the coating emulsion composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and more preferably 3 parts by mass or more, per 100 parts by mass of the total amount of the matrix resin and wax-based lubricant. The content of the film-forming aid in the coating emulsion composition is preferably 15 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of the total amount of the matrix resin and wax-based lubricant.

[0068] The coating emulsion composition is composed of a matrix resin, a wax-based lubricant, and, if necessary, additives such as film-forming aids, dispersed in water. The matrix resin contains a neutralization reaction product of an acrylic polymer (A) containing acid groups and amines, which is uniformly dispersed in water, and the wax-based lubricant is also uniformly dispersed in water due to the action of the neutralization reaction product. Therefore, a homogeneous coating film can be easily produced using this coating emulsion composition.

[0069] The method for producing a coating emulsion composition is not particularly limited, and examples include (1) a method of producing a coating emulsion composition by supplying a matrix resin, a wax-based lubricant, and, if necessary, additives such as a film-forming aid, into water, mixing and dispersing them, and (2) a method of producing a coating emulsion composition by supplying a wax-based lubricant and, if necessary, additives such as a film-forming aid, to a reaction solution obtained by producing a matrix resin, i.e., a dispersion in which the matrix resin is dispersed in water, and mixing them uniformly, with (2) being preferred.

[0070] The water content in the coating emulsion composition is preferably 100 to 500 parts by mass per 100 parts by mass of the total amount of the matrix resin and wax-based lubricant.

[0071] The procedure for using the coating emulsion composition is described below. The coating emulsion composition can be applied to a base film, such as a heat-shrinkable base film, in a general manner, and then heated and dried so that the matrix resin melts and integrates, thereby forming a coating film on the base film with excellent abrasion resistance and antistatic properties.

[0072] The coating film produced from the coating emulsion composition is firmly laminated and integrated onto the substrate film. Therefore, during processing treatments such as stretching applied to the substrate film, the coating film does not peel off from the substrate film, and the laminated and integrated state is well maintained. Furthermore, even in the case of heat-shrinkable films, such as heat-shrinkable substrate films, where the coating film is formed on the surface and then heat-shrinked, the coating film does not peel off from the surface of the heat-shrinkable substrate film after heat shrinkage, and the laminated and integrated state is well maintained.

[0073] The heat-shrinkable film comprises a heat-shrinkable base film and a coating film formed from a coating emulsion composition laminated and integrated on the heat-shrinkable base film.

[0074] The method for manufacturing a heat-shrinkable film is not particularly limited, and for example, (1) a method for manufacturing a heat-shrinkable film in which a coating emulsion composition is applied to a base film, and then the coating film is laminated and integrated by heating and drying to produce a laminated film, and then the laminated film is subjected to stretching treatment such as uniaxial stretching or biaxial stretching to make the base film a heat-shrinkable base film, and a coating film is laminated and integrated on this heat-shrinkable base film, (2) a heat-shrinkable base film is manufactured by subjecting the base film to stretching treatment such as uniaxial stretching or biaxial stretching, and then the heat shrink (3) A method for producing a heat-shrinkable film is to apply a coating emulsion composition to a heat-shrinkable base film, then heat and dry it to laminate and integrate the coating film; (4) A method for producing a heat-shrinkable film is to apply a stretching treatment such as uniaxial stretching or biaxial stretching to a base film, then apply a coating emulsion composition to the base film, heat and dry it, and then apply another stretching treatment such as uniaxial stretching or biaxial stretching to the base film to make the base film a heat-shrinkable base film, on which a coating film is laminated and integrated. The stretching treatment of the laminated film is not particularly limited, and known stretching methods such as tubular stretching, tenter stretching, and roll stretching can be used.

[0075] The base film can be any film that can be given heat shrinkability by stretching, but it is preferable that the surface of the base film on which the coating film is laminated and integrated contains a polyester resin or a polystyrene resin. The base film may also be a multilayer film formed by laminating and integrating multiple films.

[0076] As a polyester resin, for example, a resin obtained by polycondensation of a dicarboxylic acid and a diol can be used.

[0077] Examples of dicarboxylic acids used to obtain the above-mentioned polyester resins include o-phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, itaconic acid, decamethylenecarboxylic acid, their anhydrides, and lower alkyl esters.

[0078] Examples of diols used to obtain the above-mentioned polyester resins include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, and 2-ethyl-1,3-hexanediol; and alicyclic diols such as 2,2-bis(4-hydroxycyclohexyl)propane, alkylene oxide adducts of 2,2-bis(4-hydroxycyclohexyl)propane, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol.

[0079] Examples of the polystyrene resins mentioned above include aromatic vinyl hydrocarbon-conjugated diene copolymers, mixed resins of aromatic vinyl hydrocarbon-conjugated diene copolymers and aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymers, and rubber-modified impact-resistant polystyrene.

[0080] Examples of the above aromatic vinyl hydrocarbons include styrene, o-methylstyrene, and p-methylstyrene, while examples of conjugated dienes include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene.

[0081] Examples of the above-mentioned conjugated dienes include 2-methyl-1,3-butadiene (isoprene).

[0082] Examples of the above-mentioned aliphatic unsaturated carboxylic acid esters include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate.

[0083] The above-mentioned rubber-modified impact-resistant polystyrene is based on a structure consisting of, for example, a continuous phase composed of a terpolymer of styrene, alkyl methacrylate, and alkyl acrylate, and a dispersed phase composed mainly of rubber components consisting of conjugated dienes. Examples of alkyl methacrylates forming the continuous phase include methyl methacrylate and ethyl methacrylate, while examples of alkyl acrylates include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate.

[0084] The thickness of the heat-shrinkable base film is preferably 10 to 100 μm, more preferably 20 to 80 μm, and even more preferably 25 to 70 μm.

[0085] The thickness of the coating film formed on the heat-shrinkable substrate film is preferably 160 nm or more, and more preferably 165 nm or more. The thickness of the coating film formed on the substrate film is preferably 260 nm or less, more preferably 250 nm or less, and more preferably 240 μm or less. When the thickness of the coating film is 160 nm or more, the ratio of matrix resin on the surface of the coating film can be appropriately increased, improving the antistatic properties of the coating film. When the thickness of the coating film is 260 nm or less, the wax-based lubricant can be appropriately exposed on the surface of the coating film, appropriately increasing the ratio of the wax-based lubricant, and improving the abrasion resistance of the coating film.

[0086] The heat-shrinkable film manufactured as described above has a printed layer formed on its surface as needed, and after being attached to a container for soft drinks or the like, it is heated and heat-shrinks to conform to the shape of the container.

[0087] A coating film is formed on the surface of the heat-shrinkable base film that constitutes the heat-shrinkable film, and this coating film has excellent antistatic properties. Therefore, it is possible to reduce the generation of static electricity on the film surface and the adhesion of dust and other debris during the transport and processing of the laminated film that forms the base material for the heat-shrinkable film, as well as the heat-shrinkable film itself, thereby enabling smooth film processing. Furthermore, even when using the heat-shrinkable film, it is possible to reduce the generation of static electricity on the film surface and the adhesion of dust and other debris, allowing it to be used in a beautiful condition.

[0088] Furthermore, even when heat-shrinkable films rub against each other or against other objects during use, the coating film of the heat-shrinkable film has excellent abrasion resistance, so the frictional force applied to the heat-shrinkable film is reduced, and damage to the heat-shrinkable film due to friction can be largely prevented. [Effects of the Invention]

[0089] The coating emulsion composition of the present invention can easily produce a coating film with excellent abrasion resistance and antistatic properties by being applied to a substrate film or other object to be coated, followed by heating and drying. [Modes for carrying out the invention]

[0090] The present invention will be described in more detail below using examples, but the present invention is not limited thereto. Specific numerical values ​​such as blending ratios (content), physical properties, and parameters used in the following description may be replaced with the corresponding upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to") of the blending ratios (content), physical properties, and parameters described in the "Means for Solving the Problem." [Examples]

[0091] The following compounds were used in the examples and comparative examples. [Synthesis of the matrix resin that constitutes the shell] [monomer] ·styrene • Alkyl (meth)acrylates [methyl methacrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl methacrylate (dodecyl methacrylate)] Methacrylic acid (neutralized species) • Amines [Alkanolamines (triethanolamine, ethyldiethanolamine)] ·ammonia

[0092] [Synthesis of the matrix resin constituting the core] [monomer] • Alkyl (meth)acrylates [methyl methacrylate, i-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate]

[0093] [Fabrication of core-shell type particles of matrix resin] (Fabrication of the matrix resin that constitutes the shell) In a reaction apparatus equipped with a stirrer, reflux condenser, thermometer, dropping device, and nitrogen gas inlet tube, predetermined amounts of water shown in Table 1, ammonium salt of polyoxyethylene lauryl ether phosphate (manufactured by Daiichi Kogyo Seiyaku, trade name "Prysurf A219B") as an emulsifier, styrene, alkyl (meth)acrylate, methacrylic acid, and n-dodecyl mercaptan as a chain transfer agent were supplied and stirred to prepare an emulsion mixture (1) containing monomers constituting the shell.

[0094] After replacing the air in the reactor with nitrogen gas, the emulsion mixture (1) in the reactor was heated to 88°C while being stirred to initiate radical polymerization. Next, 3 parts by mass of ammonium persulfate (APS) was added to the reactor as a polymerization catalyst. 1 hour and 30 minutes after adding the ammonium persulfate, 0.2 parts by mass of ammonium persulfate was added, and then 0.2 parts by mass of sodium bisulfite was supplied after another hour. 1 hour after supplying the sodium bisulfite, the temperature of the emulsion mixture (1) was cooled to 45°C. Ammonia water (25% by mass), ethyldiethanolamine, and triethanolamine were supplied to the reactor in the molar ratios shown in Table 1, and a neutralization reaction was carried out for 30 minutes to obtain an acrylic polymer (A) containing acid groups and milky white aqueous emulsions (A-1 to A-6) containing the neutralization reaction products of amines and ammonia.

[0095] Table 1 shows amines and ammonia at 1.013 × 10 3 The boiling point (°C) at hPa is shown.

[0096] Table 1 lists the viscosity of emulsions (A-1 to A-6). The viscosity of emulsions (A-1 to A-6) was measured in accordance with JIS K5600-2-3 (2014).

[0097] The "Molar Ratio of Amines" in Table 1 represents the total number of moles of amino functional groups present in the amines that can react with the acidic groups of the acrylic polymer (A), converted proportionally to 100 moles of carboxyl groups present in methacrylic acid.

[0098] The "Molar Ratio of Ammonia" in Table 1 represents the number of moles of ammonia, calculated by proportionally converting the number of moles of ammonia to 100 moles, with the carboxyl groups of methacrylic acid being 100 moles.

[0099] (Preparation of the matrix resin that constitutes the core) The monomer compositions constituting the core were prepared by mixing the predetermined amounts of alkyl (meth)acrylate shown in Table 2 and stirring uniformly. An aqueous solution of ammonium persulfate (APS) was prepared by dissolving 2 parts by mass of ammonium persulfate (APS) in 75 parts by mass of water.

[0100] Next, predetermined amounts of aqueous emulsions (A-1 to A-6) shown in Table 2 were heated to 93°C in the reaction apparatus. Then, the monomer composition and the ammonium persulfate aqueous solution were added dropwise to the aqueous emulsion over 3 hours and 3 hours and 30 minutes, respectively. The aqueous emulsion was then maintained at 93°C for 2 hours to carry out a radical polymerization reaction. After that, the reaction solution was cooled to room temperature to obtain aqueous emulsions (B-1 to B-6) containing core-shell type particles of the matrix resin. Note that the parts by mass of the aqueous emulsions (A-1 to A-6) shown in Table 2 represent the total parts by mass of water and solids (non-volatile content). The amount of solids (non-volatile content) of the aqueous emulsion was measured in accordance with JIS K5601-1-2 (2008).

[0101] Table 2 shows the viscosity and solid content (non-volatile content) concentration (mass%) of the obtained aqueous emulsions (B-1 to B-6). The viscosity of the aqueous emulsions (B-1 to B-6) was measured in accordance with JIS K5600-2-3 (2014).

[0102] Table 3 shows the glass transition temperature (Tg) of the polymers constituting the core and shell portions, as well as the average particle size, for the core-shell type particles of the obtained matrix resin.

[0103] (Examples 1-8, Comparative Example 1) A coating emulsion composition was prepared by mixing the predetermined amounts of emulsions (B-1 to B-6) shown in Table 3, polyethylene wax emulsion (manufactured by Mitsui Chemicals, trade name "Chemipearl WF4002", solids (non-volatile content): 40% by mass, melting point: 110°C, average particle size: 0.2 μm), and butyl cellosolve with water for concentration adjustment. Note that the parts by mass of emulsions (B-1 to B-6) and polyethylene wax shown in Table 3 refer to the parts by mass of solids (non-volatile content).

[0104] The coefficient of dynamic friction and surface resistivity of the obtained coating emulsion composition were measured according to the following procedure, and the results are shown in Table 3.

[0105] Table 3 shows the "moles of amino functional groups / moles of acidic groups" and "moles of amino functional groups / moles of ammonia" for the obtained coating emulsion compositions.

[0106] (Coefficient of kinetic friction) A polyethylene terephthalate film was prepared as the base film. After heating the base film to 40°C, the coating emulsion composition was uniformly coated onto the base film. The coating emulsion composition coated onto the base film was dried at 110°C for 30 seconds, and a coating film having the thickness shown in Table 3 was laminated and integrated onto the base film to obtain a laminated film.

[0107] The laminated film was heated to 90°C and then uniaxially stretched to a stretching ratio of 5 times by the tenter stretching method to obtain a heat-shrinkable base film with a thickness of 35 μm. A coating film was then laminated and integrated onto this heat-shrinkable base film to obtain a heat-shrinkable film.

[0108] The coefficient of dynamic friction of the coating film of the obtained heat-shrinkable film was measured using a measuring device commercially available from Shimadzu Corporation under the product name "Autograph AGS-X," and evaluated based on the following criteria. A was 0.25 or less. B... The value was greater than 0.25 and less than or equal to 0.3. C... exceeded 0.3.

[0109] (Surface resistivity) A heat-shrinkable film was prepared using the same procedure as when measuring the coefficient of dynamic friction. The surface resistivity (23°C) of the coating film of the obtained heat-shrinkable film was measured using a measuring device commercially available from Nitto Seiko Analytech Co., Ltd. under the product name "Highresta UX-MCP-HT800," and evaluated based on the following criteria. A···1×10 12 It was less than or equal to Ω / □. B···1×10 12 Exceeding Ω / □ and 1 × 10 13 It was less than or equal to Ω / □. C···1×10 13 It exceeded Ω / □.

[0110] [Table 1]

[0111] [Table 2]

[0112] [Table 3]

Claims

1. A matrix resin containing a neutralization reaction product of an acrylic polymer containing acid groups and amines, a wax-based lubricant, and water, The matrix resin described above is a core-shell type particle in which the shell portion is formed by the neutralization reaction product of the acrylic polymer containing the acid group and the amines described above. A coating emulsion composition characterized in that an acrylic resin without acid groups constitutes the core portion of the core-shell type particles.

2. The coating emulsion composition according to claim 1, characterized in that the acrylic polymer containing an acid group contains an ethylenically unsaturated bond-containing monomer unit containing an acid group.

3. The coating emulsion composition according to claim 1 or 2, characterized in that the neutralization reaction product is the product of the neutralization reaction between an acrylic polymer containing an acid group, amines, and ammonia.

4. Amines are 1.013 × 10 3 A coating emulsion composition according to any one of claims 1 to 3, characterized in that it contains amines having a boiling point of 300°C or higher under hPa.

5. A coating emulsion composition according to any one of claims 1 to 3, characterized in that the ratio of the total number of moles of amino functional groups that have amines (including amines that form a neutralization reaction product with an acrylic polymer containing acid groups) and are reactable with the acid groups of the acrylic polymer to the total number of moles of acid groups that form a neutralization reaction product in the acrylic polymer and free acid groups (total number of moles of amino functional groups / total number of moles of acid groups) is 0.5 or more.

6. The coating emulsion composition according to claim 3, characterized in that the ratio of the total number of moles of amino functional groups that amines (including amines that form a neutralization reaction product with an acrylic polymer containing an acid group) have and that are reactable with the acid group of the acrylic polymer to the total number of moles of ammonia contained in the coating emulsion composition (total number of moles of amino functional groups of amines / total number of moles of ammonia) is 0.25 to 2.

0.

7. The coating emulsion composition according to claim 1, characterized in that the glass transition temperature of the shell portion in core-shell type particles is -10 to 45°C.

8. A coating film characterized by being produced from the coating emulsion composition of claims 1 to 7.

9. The coating film according to claim 8, characterized in that the thickness of the coating film is 160 to 260 nm.

10. A heat-shrinkable film comprising a heat-shrinkable base film and a coating film according to claim 8 or 9 laminated and integrated on the heat-shrinkable base film.

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