JP4550449B2 - Moisture-proof coating agent and moisture-proof processed product coated with the same - Google Patents

Description

  The present invention relates to a moisture-proof coating agent that has good transparency and can impart excellent moisture-proof properties and heat-sealing properties, and a moisture-proof processed product to which the moisture-proof coating agent is applied.

  Conventionally, packaging containers for various foods and medicines have been produced by molding and processing thermoplastic resin films such as polyethylene terephthalate (PET), nylon 6 (Ny6), and propylene (PP). . When packing products that dislike moisture in these packaging containers, it is necessary to perform moisture-proofing.

  As a moisture-proof processing method, there are a method of melting a moisture-proof material and laminating it on a substrate, and a method of applying (or impregnating) a coating liquid containing a moisture-proof material. The latter is more advantageous because it is easy. In the latter, in recent years, the use of organic solvents tends to be restricted from the standpoints of environmental protection, resource conservation, dangerous goods regulations under the Fire Service Act, workplace environment improvement, etc., and the use of aqueous media has spread. .

  As a material having moisture resistance, a composition comprising a combination of a polyolefin resin and a wax is known. For example, Patent Documents 1 and 2 disclose hot melt type compositions for moisture-proof paper made of polyolefin resin and wax.

  Patent Document 3 discloses an aqueous coating agent comprising an aqueous binder, a wax, and a polyolefin resin.

JP-A-9-316252 JP 2003-96689 A JP-A-10-53996

  However, none of the inventions described in Patent Documents 1 to 3 have sufficient moisture resistance, and in Patent Documents 1 and 2, heating to a temperature higher than the melting point of the resin composition is required for application to the substrate. In addition, a special coating apparatus and a complicated coating process are required.

  Furthermore, each of the above inventions is primarily intended for moisture-proof processing on paper, so the transparency of the moisture-proof layer is not considered, and for food packaging films where transparency after moisture-proof processing is important There were cases where it could not be used.

  Moreover, it does not meet the purpose of further stacking the moisture-proof layer on the upper surface of the moisture-proof layer to make the moisture-proof processed product more multifunctional, and lacks the heat-sealability of the moisture-proof layer required for multilayering. It was.

  The present invention solves the above-mentioned problems, provides an aqueous moisture-proof coating agent that has an excellent moisture-proof property, and can easily form a moisture-proof layer having both transparency and heat sealability, and this moisture-proof coating agent. It aims at providing the moisture-proof processed product which apply | coated.

  As a result of intensive studies to solve the above problems, the present inventors have found that a moisture-proof composition layer formed from a coating agent containing a specific proportion of a polyolefin resin and a natural wax in a specific ratio is more than the other combinations. As a result, the present inventors have found that the moisture-proof effect is specifically improved and that other performances are remarkably excellent.

That is, the gist of the present invention is as follows.
(1) Copolymerized unsaturated hydrocarbon having 3 to 6 carbon atoms, ethylene component, and unsaturated carboxylic acid unit, and 50 to 99.5 mass of the unsaturated hydrocarbon having 3 to 6 carbon atoms. % seen containing a polyolefin resin acid number of 5~100mgKOH / g (a), the mass ratio of the natural wax (B) contained in an aqueous medium, (a) and (B) (a) / (B) The moisture-proof coating agent whose 99.5 / 0.5-60 / 40 is.
(2) The moisture-proof coating agent according to (1), wherein the unsaturated hydrocarbon having 3 to 6 carbon atoms constituting the polyolefin resin (A) is propylene and / or butene.
( 3 ) A moisture-proof composition obtained by removing the medium from the moisture-proof coating agent described in (1) or (2) .
( 4 ) The moisture-proof composition according to ( 3 ), wherein the water vapor transmission coefficient at 40 ° C. and 100% RH is 150 g · μm / m ² · day or less.
( 5 ) A moisture-proof processed product comprising a substrate and a moisture-proof layer comprising the moisture-proof composition according to ( 3) or (4 ).
( 6 ) The moisture-proof processed product according to ( 5 ), wherein the substrate is a thermoplastic resin film.
( 7 ) The moisture-proof processed product according to ( 6 ), wherein the haze is 10% or less.
( 8 ) The moisture-proof processed product according to ( 5 ), wherein the base material is paper.
( 9 ) The moisture-proof processed product according to any one of ( 5) to (8 ), which is further laminated on the moisture-proof layer.
( 10 ) The method for producing a moisture-proof coating agent according to ( 1 ), comprising a step of mixing an aqueous dispersion containing the polyolefin resin (A) and an aqueous dispersion of natural wax (B). .

  According to the moisture-proof coating agent of the present invention, it is possible to easily form a moisture-proof layer that is a thin film and excellent in moisture resistance with a simple apparatus. In addition, since this moisture-proof layer is also excellent in heat sealability, lamination for the purpose of further multifunctionalization can be easily performed. In addition, since this moisture-proof layer has high transparency, it does not impair the transparency even when applied to a transparent substrate such as a thermoplastic resin film, and is suitable as a film for packaging and packaging. is there. In addition, if an aqueous medium is used as the liquid medium of the coating agent of the present invention, it will be suitable for purposes such as environmental protection and compliance with dangerous goods regulations. In this case, the coating agent is a polyolefin resin. It can be most easily obtained by a method of mixing an aqueous dispersion and an aqueous dispersion of wax.

  Hereinafter, the present invention will be described in detail.

  The moisture-proof coating agent of the present invention contains a specific polyolefin resin (A) and natural wax (B) in a liquid medium.

  The liquid medium is not particularly limited as long as it is liquid at room temperature and normal pressure, such as organic solvent, water, but storage stability, ease of handling, and environmental protection, resource saving, regulations on dangerous goods by the Fire Service Act, etc. From the standpoint of improving the work environment, the use of an aqueous medium is preferable. What contains 50 mass% or more of water with an aqueous medium is preferable, More preferably, it is 80 mass% or more. The solvent other than water contained in the aqueous medium is preferably a hydrophilic organic solvent, and specific examples thereof include alcohols such as methanol, ethanol, isopropanol, n-propanol, ethylene glycol-ethyl ether, and ethylene glycol-n-butyl ether. , Ethers such as tetrahydrofuran and 1,4-dioxane, ketones such as acetone and methyl ethyl ketone, methyl acetate, acetic acid-n-propyl, isopropyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate Such as esters, acetonitrile and the like, those having solubility in water at 20 ° C. of preferably 10 g / L or more, particularly preferably 50 g / L or more are used. Further, ammonia and diethylamine, triethylamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N-diethanolamine, 3-methoxypropylamine, 3-diethylaminopropylamine, dimethylamino Examples include basic compounds such as organic amine compounds such as propylamine, morpholine, and methylmorpholine.

  Moreover, as a form in which the polyolefin resin (A) and the natural wax (B) are contained in the liquid medium, there is a form of a solution or a dispersion, but a dispersion is preferable, and storage stability and easy handling are possible. An aqueous dispersion is particularly preferred for reasons such as environmental protection.

  The polyolefin resin (A) must contain 50 to 99.5% by mass of an unsaturated hydrocarbon having 3 to 6 carbon atoms as a copolymerization component, and is 60 to 99% by mass from the viewpoint of moisture resistance. Is more preferable, 70 to 98% by mass is more preferable, and 80 to 98% by mass is further preferable. If the content of the unsaturated hydrocarbon having 3 to 6 carbon atoms is less than 50% by mass, the moisture-proof property is remarkably lowered, and if it exceeds 99.5% by mass, the mixing stability with the wax may be lowered. Examples of the unsaturated hydrocarbon having 3 to 6 carbon atoms include alkenes such as propylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene and 1-hexene. From the viewpoint of ease of resin production, ease of water treatment, moisture proofing, heat sealability, etc., it is preferably a propylene component or a butene component (1-butene, isobutene, etc.), and both are used in combination. You can also The polyolefin resin used in the present invention preferably further contains 2 to 50% by mass of an ethylene component in addition to the above-mentioned unsaturated hydrocarbon having 3 to 6 carbon atoms. By containing an ethylene component, it becomes easy to make the resin water-based, and moisture resistance and heat sealability at low temperatures are improved.

  In order to develop better moisture resistance and heat sealability, the polyolefin resin (A) is preferably a copolymer of propylene component, butene component, and ethylene component, and the ratio is When the total of the three components is 100 parts by mass, the propylene component is 9.5 to 90 parts by mass, the butene component is 9.5 to 90 parts by mass, and the ethylene component is 0.5 to 40 parts by mass.

  In the polyolefin resin (A), the copolymerization form of each component is not limited, and examples thereof include random copolymerization and block copolymerization. From the viewpoint of ease of polymerization, random copolymerization is preferable. Moreover, you may mix 2 or more types of polyolefin resin so that it may become the structural component ratio of this invention.

  In addition to the above components, other components may be contained in an amount of about 20% by mass or less, preferably 2 to 15% by mass of the whole polyolefin resin (A). Examples of other components include 1-octene, norbornenes and the like. Alkenes and dienes with more than 6 carbon atoms, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, (meth) (Meth) acrylic acid esters such as dodecyl acrylate, stearyl (meth) acrylate, dimethyl maleate, diethyl maleate, dibutyl maleate, dilauryl maleate, dioctyl maleate, didodecyl maleate, distearyl maleate, etc. Maleic acid esters, (meth) acrylic acid amides, methyl vinyl ether, ethyl vinyl ether Alkyl vinyl ethers such as ruthenium, vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl versatate, and vinyl alcohol obtained by saponifying vinyl esters with basic compounds, 2- Hydroxyethyl acrylate, glycidyl (meth) acrylate, (meth) acrylonitrile, styrene, substituted styrene, vinyl halides, halogenated vinylidenes, carbon monoxide, sulfur dioxide, and the like, and mixtures thereof can also be used. . Especially, it is more preferable that 0.1-15 mass% of (meth) acrylic acid ester of the whole polyolefin resin (A) is contained from the point of the ease of water-izing resin and heat-sealability, 0.5-15 mass% It is more preferable to contain, and it is especially preferable to contain 1-10 mass%. Specific examples of (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth ) Octyl acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like.

  The weight average molecular weight of the polyolefin resin (A) is preferably in the range of 10,000 to 150,000, more preferably from 20,000 to 120,000, more preferably from 20,000 to 100,000 from the viewpoint of water-based resin and heat sealability. More preferably, it is particularly preferably 30,000 to 90,000, most preferably 40,000 to 80,000. When the weight average molecular weight is less than 10,000, the heat sealability tends to decrease, or the obtained coating film tends to be brittle even if it is hard. When the weight average molecular weight exceeds 150,000, the viscosity of the coating agent becomes high and handling becomes difficult. In addition, the weight average molecular weight of resin can be calculated | required on the basis of polystyrene resin using a gel permeation chromatography (GPC).

  When an aqueous medium is used as the solvent, the acid value of the polyolefin resin (A) is preferably 5 to 100 mgKOH / g from the viewpoint of dispersibility. This range is more preferably 10 to 100 mg KOH / g, further preferably 10 to 90 mg KOH / g, particularly preferably 15 to 85 mg KOH / g, and most preferably 15 to 80 mg KOH / g. If the acid value is less than 5 mgKOH / g, it tends to be difficult to make the polyolefin resin water-based.On the other hand, if it exceeds 100 mgKOH / g, it becomes easy to make the resin water-soluble, but PET or PP There exists a tendency for the heat-sealing property with respect to materials, etc. to fall.

  Giving an acid value to the polyolefin resin (A) is achieved by copolymerizing unsaturated carboxylic acid units. The unsaturated carboxylic acid unit is introduced by unsaturated carboxylic acid or its anhydride. Specific examples include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, anhydrous In addition to aconitic acid, fumaric acid, crotonic acid, citraconic acid, mesaconic acid, allyl succinic acid, etc., at least one carboxyl group in the molecule (in the monomer unit) such as half ester or half amide of unsaturated dicarboxylic acid Alternatively, a compound having an acid anhydride group can be used. Of these, maleic anhydride, acrylic acid, and methacrylic acid are preferred, and maleic anhydride is more preferred from the viewpoint of ease of introduction into the polyolefin resin. The form of copolymerization is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. Incidentally, the acid anhydride unit introduced into the polyolefin resin tends to take an acid anhydride structure in a dry state, and in the aqueous medium containing the basic compound, part or all of the acid anhydride units are opened to form a carboxylic acid or It tends to be the salt structure.

  To graft copolymerize the unsaturated carboxylic acid to the polyolefin resin (A), for example, in the presence of a radical generator, a method in which the polyolefin resin and the unsaturated carboxylic acid are heated and melted to a temperature equal to or higher than the melting point of the polyolefin resin, An example is a method in which a polyolefin resin is dissolved in an organic solvent and then reacted by heating and stirring in the presence of a radical generator. Examples of the radical generator used for graft copolymerization include di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, tert-butyl cumyl peroxide, benzoyl peroxide, dilauryl peroxide, Examples thereof include organic peroxides such as cumene hydroperoxide, tert-butyl peroxybenzoate, ethyl ethyl ketone peroxide, and di-tert-butyl diperphthalate, and azonitriles such as azobisisobutyronitrile. These may be appropriately selected and used depending on the reaction temperature.

  The polyolefin resin (A) may be chlorinated in the range of 1 to 40% by mass.

  When an unsaturated carboxylic acid is introduced into the polyolefin resin (A), it is preferable to use a basic compound as the aqueous medium. A part of the carboxyl group is neutralized with a basic compound, and the dispersion stability of the resin is improved.

  As the natural wax (B) used in the present invention, plant wax such as candelilla wax, carnauba wax, rice wax, and wax, animal wax such as shellac wax and lanolin wax, mineral wax such as montan wax and ozokerite, Examples thereof include petroleum waxes such as paraffin wax and microcrystalline wax. Of these, candelilla wax, carnauba wax, and paraffin wax are preferable because they exhibit excellent moisture resistance, and candelilla wax and paraffin wax are particularly preferable.

  In the moisture-proof coating agent of the present invention, the mass ratio (A) / (B) of the polyolefin resin (A) and the natural wax (B) is 99.5 in order to maintain the transparency and heat sealability of the moisture-proof composition layer. /0.5 to 60/40, preferably 99/1 to 70/30, more preferably 97/3 to 75/25, which is preferable in terms of balance between content and moisture-proof efficiency. The range is more preferably 97/3 to 85/15, and 95/5 to 80/20 is particularly preferable depending on the application. When the wax content is less than 0.5% by mass, moisture resistance is not sufficiently exhibited, and a processed product coated with such a moisture-proof coating agent may not exhibit sufficient moisture resistance. On the other hand, when it is 40% by mass or more, the haze of the moisture-proof composition layer may increase or the heat sealability may decrease.

The water vapor transmission coefficient of the moisture-proof layer obtained from the moisture-proof coating agent of the present invention at 40 ° C. and 100% RH needs to be 150 g · μm / m ² · day or less, and is 120 g · μm / m ² · day or less. It is preferably 100 g · μm / m ² · day or less, more preferably 70 g · μm / m ² · day or less, and even more preferably 50 g · μm / m ² · day or less. Is particularly preferred. When the water vapor transmission coefficient exceeds 150 g · μm / m ² · day, the coating amount (thickness) increases to give a predetermined moisture resistance.

  In the moisture-proof coating agent of the present invention, the content of the surfactant generally used to disperse the hydrophobic compound in the aqueous medium is the solid content in the coating agent from the viewpoint of moisture-proof and heat-sealability. {Polyolefin resin (A) and natural wax (B)} It is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and further preferably 5 parts by mass or less with respect to 100 parts by mass. It is particularly preferable that it is not substantially contained (for example, 0.1 parts by mass or less). Since the surfactant is difficult to remove by heating or reduced pressure, it remains in the moisture-proof composition layer and may deteriorate the properties of the moisture-proof composition layer. Those which do not substantially contain a surfactant are excellent in coating film properties, particularly moisture resistance and heat sealability, and their performance hardly changes in the long term.

  Examples of the surfactant in the present invention include a cationic surfactant, an anionic surfactant, a nonionic (nonionic) surfactant, an amphoteric surfactant, a fluorosurfactant, and a reactive surfactant. In addition to those generally used for emulsion polymerization, emulsifiers are also included. For example, anionic surfactants include sulfates of higher alcohols, higher alkyl sulfonic acids and salts thereof, alkyl benzene sulfonic acids and salts thereof, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, vinyl sulfone salts. Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, ethylene oxide. -Compounds having a polyoxyethylene structure such as propylene oxide copolymer and sorbitans such as polyoxyethylene sorbitan fatty acid ester It includes conductors, and examples of the amphoteric surfactant, lauryl betaine, lauryl dimethyl amine oxide, and the like. Examples of reactive surfactants include alkylpropenylphenol polyethylene oxide adducts and their sulfate esters, allyl alkylphenol polyethylene oxide adducts and their sulfate esters, allyl dialkylphenol polyethylene oxide adducts and their sulfate esters, etc. A compound having a reactive double bond may be mentioned.

  The moisture-proof coating agent of the present invention may contain a crosslinking agent in order to improve performance such as solvent resistance. The blending ratio of the crosslinking agent is preferably in the range of 0.1 to 30 parts by mass and more preferably in the range of 0.1 to 20 parts by mass with respect to 100 parts by mass of the polyolefin resin (A). When the addition amount is less than 0.1 parts by mass, the effect of addition is small, and when it exceeds 30 parts by mass, the moisture resistance and heat sealability tend to decrease. As the crosslinking agent, a compound having a self-crosslinking property, a compound having a plurality of functional groups that react with a carboxyl group in the molecule, a metal salt having a polyvalent coordination site, and the like can be used. Melamine compounds, urea compounds, epoxy compounds, carbodiimide compounds, oxazoline group-containing compounds, zirconium salt compounds, silane coupling agents and the like are preferable. These crosslinking agents may be used alone or in combination of two or more.

  Furthermore, the moisture-proof coating agent of the present invention includes organic / inorganic fillers, plate pigments, inorganic layered compounds, pigments, pigment dispersants, wetting agents, antifoaming agents, and thickeners as long as the properties are not impaired. , Freeze / thaw stabilizer, coating aid, antiseptic, antifungal agent, anticorrosive agent, plasticizer, antioxidant, UV absorber, radical scavenger, weathering agent, flame retardant, leveling agent, anti-waxing agent Etc. can be added.

  The solid content in the moisture-proof coating agent of the present invention can be appropriately selected depending on the film forming conditions, the target coating amount and performance, etc., and is not particularly limited, but the viscosity of the coating composition is kept moderate, And 1-60 mass% is preferable at the point which expresses favorable coating-film formation ability, 3-50 mass% is more preferable, 5-45 mass% is further more preferable, 10-40 mass% is especially preferable.

  The production method for obtaining the moisture-proof coating agent of the present invention is not particularly limited as long as it is a method in which the polyolefin resin (A) and the natural wax (B) are uniformly mixed and dispersed or dissolved in a liquid medium. Although not intended, for example, there are two examples of manufacturing an aqueous dispersion type moisture-proof coating agent: (A) Aqueous dispersion of polyolefin resin (A) prepared in advance and natural A method of mixing an aqueous dispersion of wax (B); (A) a method of simultaneously dispersing aqueous dispersion of polyolefin resin (A) and natural wax (B). Among these, the method (a) is preferable because an aqueous moisture-proof coating agent comprising a combination of various natural waxes and polyolefin resins can be prepared more easily.

  The preparation method of the aqueous dispersion of the polyolefin resin (A) used in the method (a) includes (i) a method of preparing an aqueous dispersion such as a polyolefin resin by emulsion polymerization, and (ii) a molten state or solution of the polyolefin resin. And then emulsifying by dispersing in water in the presence of a surfactant and finely pulverizing with a shearing force of stirring. (Iii) Melting and kneading polyolefin resin, water, surfactant and / or carboxy-modified wax with an extruder And (iv) a method in which emulsification is performed by heating and stirring an aqueous medium containing a polyolefin resin, a basic compound, and the above-described water-soluble organic solvent in a sealed container under pressure. . Among these, the method (iv) is preferable because a surfactant is not required.

  As the method (iv) in the production method (a), it can be prepared by heating and stirring using a known solid / liquid stirring device, an emulsifier, etc., preferably a device capable of pressurization of 0.1 MPa or more. it can. The stirring method and the rotation speed of stirring are not particularly limited, but low-speed stirring that allows the resin to float in the medium may be used, and high-speed stirring (for example, 1,000 rpm or more) is not essential. Raw materials such as a polyolefin resin (A), a basic compound, and an aqueous medium are charged into such an apparatus, and then the temperature in the tank is 60 to 220 ° C, preferably 80 to 200 ° C, more preferably 100 to 190 ° C. Particularly preferably, the polyolefin resin is sufficiently aqueousized by continuing stirring until the coarse particles disappear (for example, 5 to 120 minutes) while maintaining the temperature at 100 to 180 ° C., and preferably under stirring. An aqueous dispersion can be obtained by cooling to 40 ° C. or lower. When the temperature in the tank is lower than 60 ° C., it becomes difficult to make the polyolefin resin aqueous. When the temperature in a tank exceeds 220 degreeC, there exists a possibility that the molecular weight of polyolefin resin may fall.

  The number average particle diameter of the resin particles in the aqueous dispersion of polyolefin resin is preferably 1 μm or less from the viewpoint of stability, and more preferably 0.5 μm or less from the viewpoint of moisture resistance, transparency of the coating film, and low-temperature film-forming properties. Preferably, it is 0.3 μm or less, more preferably 0.2 μm or less. When the number average particle diameter exceeds 1 μm, the stability of the coating agent is remarkably deteriorated, and the performance such as moisture resistance and transparency of the coating film is deteriorated. The volume average particle size is also preferably 2 μm or less, more preferably 1 μm or less, further preferably 0.5 μm or less, and further preferably 0.3 μm from the viewpoint of performance such as coating agent stability, moisture resistance, and transparency of the coating film. The following are particularly preferred: Further, although there is no lower limit to the particle diameter, the number average particle diameter and the volume average particle diameter in the dispersion achieved by various production methods described later are both about 0.01 μm. In addition, the number average particle diameter and volume average particle diameter of the polyolefin resin (A) are measured by a dynamic light scattering method that is generally used for measuring the particle diameter of fine particles.

  The aqueous dispersion of the natural wax (B) can be produced by using the natural wax (B), a basic compound, and an aqueous medium by the same apparatus and operation as in the above-mentioned aqueous polyolefin resin (iv). As production conditions, the temperature is kept at 45 to 200 ° C., preferably 60 to 150 ° C., more preferably 80 to 120 ° C., and stirring is preferably continued until coarse particles disappear (for example, 5 to 120 minutes). Thus, the wax can be sufficiently dispersed, and then cooled to 40 ° C. or lower, preferably with stirring, to obtain a dispersion. When the temperature in the tank is lower than 45 ° C., it is difficult to disperse the wax. A reaction in which the temperature in the tank exceeds 200 ° C. is not preferable because it is uneconomical.

  In the dispersion state of the aqueous dispersion of the natural wax (B) thus obtained, the number average particle diameter is preferably 0.5 μm or less from the viewpoint of the mixing property with the polyolefin resin (A). Is preferably 0.3 μm or less, and most preferably 0.2 μm or less from the viewpoint of the transparency and transparency of the coating film. Here, the number average particle diameter of the wax is measured by a dynamic light scattering method which is generally used for measuring the particle diameter of the fine particles.

  The solid content concentration of each aqueous dispersion obtained as described above can be appropriately adjusted by distilling off the aqueous medium (including stripping), diluting with an aqueous medium, or the like. In addition, any of the above-described methods for producing an aqueous dispersion does not require a surfactant for dispersion of polyolefin resin or candelilla wax, but in the case of dispersion of paraffin wax, as necessary. , And may be used within a range not exceeding the total amount described above.

  Next, the obtained aqueous dispersions of polyolefin and natural wax are mixed. In mixing, a known liquid / liquid mixing apparatus may be used as appropriate. Since the dispersion and mixing properties of the aqueous polyolefin resin dispersion and the aqueous natural wax dispersion are good, a simple mixing operation is possible for a very short time. Further, after mixing, the solid content concentration can be adjusted by the same method as described above.

  As the method (a) for producing the moisture-proof coating agent of the present invention, for example, the method (iv) in which a polyolefin resin and natural wax, a basic compound, and an aqueous medium are heated and stirred in a container can be employed. The raw material is charged into the apparatus, and then heated (for example, 45 to 200 ° C.), and preferably, the polyolefin resin and the natural wax are sufficiently dispersed by continuing to stir until coarse particles disappear (for example, 5 to 120 minutes). After that, the aqueous moisture-proof coating agent can be obtained by cooling to 40 ° C. or lower, preferably with stirring. Moreover, solid content concentration can be adjusted similarly to a manufacturing method (a).

  The moisture-proof coating agent of the present invention is excellent in coating properties on various substrates, paper, synthetic paper, thermoplastic resin film, plastic product, steel sheet, aluminum foil, wood, woven fabric, knitted fabric, non-woven fabric, gypsum It can be used for coating or impregnation on boards, wood boards, etc., and a moisture-proof coating layer can be laminated by removing the liquid medium. Especially, it is preferable to use for paper, a synthetic paper, and a thermoplastic resin film, and when using a thermoplastic resin film, since it can be set as a transparent moisture proof film, it is more preferable.

  Examples of thermoplastic resin films include polyester resins such as PET, polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, and polyhydroxycarboxylic acids such as polyglycolic acid and polylactic acid. Biodegradable resins represented by aliphatic polyester resins such as poly (ethylene succinate) and poly (butylene succinate), polyamide resins such as Ny6, nylon 66, nylon 46, PP, polyethylene, ethylene-vinyl acetate Examples thereof include films made of thermoplastic resins such as polyolefin resins such as copolymers, polyimide resins, polyarylate resins or mixtures thereof, and laminates thereof, among which polyester, polyamide, polyethylene Ethylene - vinyl acetate copolymer, consisting of polypropylene film can be suitably used. These base films may be unstretched films or stretched films, and the production method is not limited. Moreover, although the thickness of a base film is not specifically limited, Usually, what is necessary is just to be the range of 1-500 micrometers. Furthermore, you may perform what is called in-line coating which apply | coats the water-proof moisture-proof coating agent of this invention to an unstretched film, and extends | stretches the coat film.

  The thermoplastic resin film is preferably subjected to corona discharge treatment. Further, silica, alumina or the like may be deposited, and a gas barrier coat layer such as an oxygen gas barrier layer may be laminated.

  The moisture-proof film obtained by laminating the moisture-proof composition of the present invention has a haze of 10% or less. That is, it has very high transparency. The transparency of the moisture-proof composition layer varies depending on the ratio of the polyolefin resin (A) and the natural wax (B), but for applications such as packaging materials, the haze of the film is more preferably 8% or less, 6% The following is more preferable.

  When paper is used as the substrate, moisture-proof paper can be used. Examples of the base paper include craft paper, liner paper, art paper, coated paper, and carton paper.

  Further, when synthetic paper is used as the base material, it can be moisture-proof synthetic paper. The structure of the synthetic paper is not particularly limited. Therefore, it may be a single layer structure or a multilayer structure. As the multilayer structure, for example, a two-layer structure of a base material layer and a surface layer, a three-layer structure in which a surface layer exists on the front and back surfaces, and another resin film layer exists between the base material layer and the surface layer. A multilayer structure can be exemplified. Moreover, each layer may contain the inorganic or organic filler, and does not need to contain it. A microporous synthetic paper having a large number of fine voids can also be used.

  The method of applying the moisture-proof coating agent of the present invention to the substrate is not particularly limited, but gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dipping Coating, brushing, etc. can be employed. What is necessary is just to determine suitably the application quantity of a moisture-proof coating agent with a base material. When the base material is a thermoplastic resin film, the thickness of the moisture-proof composition layer in the present invention is desirably at least 0.1 μm in order to sufficiently improve the moisture-proof property. From the viewpoint of moisture resistance, it is better that the thickness of the moisture-proof composition layer is thicker, but the feature of the present invention is that the moisture-proof composition is exhibited even if the thickness of the moisture-proof composition layer is thin, and therefore the moisture-proof coating of the present invention. If an agent is used, moisture resistance can be improved while utilizing the characteristics of the substrate. Therefore, the thickness of the moisture-proof composition layer of the present invention is preferably 0.1 to 10 μm, more preferably 0.2 to 8 μm, and particularly preferably 0.3 to 7 μm.

In addition, when the base material is soaked with a moisture-proof coating agent such as paper, woven fabric, knitted fabric, non-woven fabric, etc., the coating amount is difficult to evaluate in terms of thickness. the amount may be in the range of 1-200 g / m ^2.

  In expressing the moisture-proof performance of the moisture-proof coating agent of the present invention, the drying temperature is preferably 50 to 240 ° C, more preferably 60 to 210 ° C, and still more preferably 70 to 200 ° C. When the drying temperature is less than 50 ° C., the aqueous medium cannot be sufficiently volatilized, or it takes time to volatilize, and it is difficult to develop good moisture-proof performance. On the other hand, when the drying temperature exceeds 240 ° C., the moisture-proof performance tends to decrease.

  In addition, the moisture-proof processed product (moisture-proof film, moisture-proof paper, moisture-proof synthetic paper, etc.) treated with the moisture-proof coating agent of the present invention has an excellent moisture-sealing property. Materials can be laminated. As a base material that can be combined, a thermoplastic resin film, paper, synthetic paper, wood, woven fabric, knitted fabric, non-woven fabric, etc., as well as the above-described base materials, metal foils such as aluminum, etc. are appropriately selected and used. Can be the same or different. Moreover, you may combine the moisture-proof processed goods of this invention.

  The moisture-proof processed product treated with the moisture-proof coating agent of the present invention can be used for various applications such as paper cups, moisture-proof corrugated cardboard, moisture-proof paper, moisture-proof film, etc. it can.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. Various physical properties were measured or evaluated by the following methods.
(1) Acid value of polyolefin resin Measured according to JIS K5407. The unit is mgKOH / g.
(2) Acid value and saponification value of wax These are values determined by titration with KOH according to JIS K-0070, and the unit is mgKOH / g.
(3) Structure of polyolefin resin other than unsaturated carboxylic acid unit ¹ H-NMR and ¹³ C-NMR analysis (manufactured by Varian, 300 MHz) at 120 ° C. in orthodichlorobenzene (d ₄ ) was obtained. ^{In 13} C-NMR analysis, measurement was performed using a gated decoupling method in consideration of quantitativeness.
(4) Weight average molecular weight of polyolefin resin Calibration curve prepared with polystyrene standard sample by dissolving the sample in tetrahydrofuran using GPC analysis (HLC-8020 manufactured by Tosoh Corporation, column is TSK-GEL) and measuring at 40 ° C. From this, the weight average molecular weight was determined.
(5) Solid Concentration of Aqueous Dispersion An appropriate amount of an aqueous dispersion of polyolefin resin or natural wax was weighed and heated at 150 ° C. until the mass of the residue (solid content) reached a constant weight. %).
(6) Dispersed particle diameter For the dispersed particles of polyolefin resin or natural wax in the aqueous dispersion, a Microtrac particle size distribution analyzer UPA150 (manufactured by Nikkiso Co., Ltd., MODEL No. 9340) was used, and the number average particle diameter (mn), volume The average particle size (mv) was measured.
(7) Pot life of moisture-proof coating agent The appearance when the prepared moisture-proof coating agent was allowed to stand at room temperature for 90 days was evaluated in the following two stages.
○: Solidification and aggregation were not observed ×: Solidification and aggregation were observed

  Hereinafter, in the evaluation of (8) to (11), as the biaxially stretched PET film, the Emblet PET12 (thickness 12 μm) manufactured by Unitika Ltd., and as the biaxially stretched Ny6 film, the emblem (15 μm thick) manufactured by Unitika Ltd. As the stretched PP film, OP U-1 (thickness 20 μm) manufactured by Tosero Corporation was used.

(8) Haze Based on JIS-K7361-1, the haze measurement of the moisture-proof processed film was performed using a turbidimeter (Nippon Denshoku Industries Co., Ltd., NDH2000), and transparency was evaluated. However, this evaluation value is the turbidity (biaxially stretched PET film: 3.6%, stretched Ny6 film: 3.1%, stretched PP film: 1.8%) of the base film used in each example. Contains.
(9) Water vapor transmission rate, water vapor transmission coefficient After coating a predetermined amount of coating agent using a film applicator (Yasuda Seiki Seisakusho, 542-AB) with a Mayer bar installed on the non-corona surface of various films. A moisture-proof composition layer was formed by drying at 100 ° C. for 2 minutes.
Next, the water vapor transmission rate of the moisture-proof processed film at 40 ° C. and 100% RH was measured by a moisture permeability measuring device (PERMATRAN-W3 / 31 MW) manufactured by Mocon Co., Ltd., and Q _F was obtained.
On the other hand, the water vapor transmission coefficient P _C of the moisture-proof composition layer is the above-mentioned Q _F , the water vapor permeability Q _{B of} the base film, and the thickness L of the moisture-proof composition layer (difference in average thickness between the moisture-proof processed film and the base film) And calculated based on the following relational expression. In addition, Q _B (thickness 12 μm) of the PET film was 60 g / m ² · day, Q _B of the PP film was 9.0 g / m ² · day, and Q _B of the Ny6 film was 600 g / m ² · day.

1 / Q _F = 1 / Q _B + L / P _C
However, Q _F : Water vapor permeability of moisture-proof processed product (g / m ² · day)
Q _B : Water vapor permeability of the substrate (g / m ² · day)
P _C : Water vapor transmission coefficient of moisture-proof composition layer (g · μm / m ² · day)
L: Moisture-proof composition layer thickness (μm)

(10) Heat-sealability (I): Heat-seal between coating surfaces Install a Meyer bar on a non-corona surface of various films with a film applicator (542-AB, manufactured by Yasuda Seiki Co., Ltd.). Then, after coating a predetermined amount, it was dried at 100 ° C. for 2 minutes. The film was pressed at 120 ° C. with a heat press (sealing pressure of 0.3 MPa for 10 seconds) so that the coating film of the obtained moisture-proof processed film was in contact. This sample is cut out with a width of 15 mm, and one day later, the peel strength of the coating film is measured at a pulling speed of 200 mm / min and a pulling angle of 180 degrees using a tensile testing machine (Intesco Precision Universal Material Testing Machine Model 2020). Thus, heat sealability (heat seal strength) was evaluated.
(11) Heat-sealing property (II): Heat-sealing between moisture-proof processed film and other materials The heat-sealing properties between the moisture-proof processed film and other materials were also examined. Apply to the heat press machine (sealing pressure of 0.3 MPa for 10 seconds) so that the coated surface of the moisture-proof film is in contact with the aluminum foil (Mitsubishi Aluminum Co., Ltd., thickness 15 μm) and A4 size high-quality paper (Daishowa Paper). And pressed at 120 ° C. This sample was cut out with a width of 15 mm, and one day later, using a tensile tester (precision universal material tester type 2020 manufactured by Intesco), the peel strength of the coating film was measured at a pulling speed of 200 mm / min and a pulling angle of 180 degrees. The heat sealability (heat seal strength) was evaluated.

(Production of polyolefin resin P-1)
280 g of propylene-butene-ethylene terpolymer (manufactured by Huls Japan Co., Ltd., Bestplast 708, propylene / butene / ethylene = 64.8 / 23.9 / 11.3% by mass), 4 pieces equipped with a stirrer, a condenser, and a dropping funnel After being melted by heating in a nitrogen atmosphere in a neck flask, 32.0 g of maleic anhydride as an unsaturated carboxylic acid and 6.0 g of dicumyl peroxide as a radical generator were maintained while maintaining the system temperature at 165 ° C. A 20 g solution of heptane was added over 1 hour, followed by reaction for 1 hour. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure in a vacuum dryer to obtain polyolefin resin P-1.

(Production of polyolefin resin P-2)
Propylene-butene-ethylene terpolymer (manufactured by Huls Japan, Bestplast 408, propylene / butene / ethylene = 12.3 / 82.2 / 5.5% by mass) is the same as the production of polyolefin resin P-1 Polyolefin resin P-2 was obtained by the method.

(Production of polyolefin resin P-3)
100 g of propylene-butene-ethylene terpolymer (manufactured by Huls Japan Co., Ltd., Bestplast 708, propylene / butene / ethylene = 64.8 / 23.9 / 11.3% by mass), 500 g of toluene, a stirrer, a condenser tube and a dropping funnel are attached. In a four-necked flask, the mixture was heated and melted under a nitrogen atmosphere, and a solution of 1.0 g of dicumyl peroxide as a radical generator in 20 g of heptane was added over 1 hour while maintaining the system temperature at 110 ° C. and stirring. Thereafter, 7.0 g of maleic anhydride, 10.0 g of octyl acrylate, and 10 g of heptane of 0.5 g of dicumyl peroxide were added dropwise as an unsaturated carboxylic acid over 1 hour, followed by reaction for 1 hour. After completion of the reaction, the reaction mixture was cooled to room temperature, and then the obtained reaction product was put into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted substances, and then dried under reduced pressure in a vacuum dryer to obtain polyolefin resin P-3. The weight average molecular weight of P-3 was 50,000, the acid value was 48 mgKOH / g, and the content of octyl acrylate in the resin was 6.5% by mass.

  Table 1 shows the characteristics of the polyolefin resins P-1 to P-3.

Reference example 1
(Preparation of aqueous polyolefin resin dispersion E-1)
60.0 g of polyolefin resin (P-1), 45.0 g of ethylene glycol-n-butyl ether (manufactured by Wako Pure Chemical Industries, Ltd.), 6 When 9 g of N, N-dimethylethanolamine (Wako Pure Chemical Industries, Ltd.) and 188.1 g of distilled water were charged into a glass container and stirred at a rotation speed of a stirring blade of 300 rpm, resin was precipitated at the bottom of the container. Was not observed and it was confirmed that it was floating. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 ° C. and further stirred for 60 minutes. Then, after cooling to room temperature (about 25 ° C.) while stirring with air rotation at 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) As a result, a milky-yellow uniform polyolefin resin aqueous dispersion E-1 was obtained. There was almost no residual resin on the filter. Various characteristics of the aqueous dispersion are shown in Table 2.

Reference example 2
(Preparation of aqueous polyolefin resin dispersion E-2)
Using a stirrer equipped with a 1 L glass container that can be sealed with a heater, 60.0 g polyolefin resin (P-2), 90.0 g n-propanol (manufactured by Wako Pure Chemical Industries, Ltd.), 7.8 g Triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 142.2 g of distilled water were charged into a glass container and stirred at a rotation speed of the stirring blade of 300 rpm. It was confirmed that Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 ° C. and further stirred for 60 minutes. Then, after cooling to room temperature (about 25 ° C.) while stirring with air rotation at 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) As a result, a milky-yellow uniform polyolefin resin aqueous dispersion E-2 was obtained. There was almost no residual resin on the filter. Various characteristics of the aqueous dispersion are shown in Table 2.

Reference example 3
(Preparation of aqueous polyolefin resin dispersion E-3)
Using P-3 as the polyolefin resin, a milky-yellow uniform polyolefin resin aqueous dispersion E-3 was obtained according to the method of Reference Example 2. Various characteristics of the aqueous dispersion are shown in Table 2.

Reference example 4
(Preparation of aqueous polyolefin resin dispersion E-4)
Except for adding 7 parts by mass of Neugen EA-190D (Daiichi Kogyo Seiyaku Co., Ltd., nonionic surfactant) as a surfactant with respect to 100 parts by mass of the solid content of the polyolefin resin when making the polyolefin resin aqueous. According to the method of Reference Example 1, a milky-yellow uniform polyolefin resin aqueous dispersion E-4 was obtained. Various characteristics of the aqueous dispersion are shown in Table 2.

Reference Example 5
(Preparation of aqueous polyolefin resin dispersion S-1)
An ethylene-acrylic acid ester-maleic anhydride copolymer {manufactured by Sumitomo Chemical Co., Bondine HX-8210, ethylene / ethyl acrylate / maleic anhydride = 91/6/3 (mass ratio)} was used as the polyolefin resin.
Using a stirrer equipped with a hermetic pressure-resistant 1 liter glass container with a heater, 60.0 g polyolefin resin (Bondaine HX-8210), 60.0 g isopropanol (manufactured by Wako Pure Chemical Industries, Ltd.), 3.9 g N, N-dimethylethanolamine (manufactured by Wako Pure Chemical Industries, Ltd.) and 176.1 g of distilled water were charged into a glass container and stirred at a rotation speed of a stirring blade of 300 rpm. It was not recognized and it was confirmed that it was floating. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 140 ° C. and further stirred for 60 minutes. Then, after cooling to room temperature (about 25 ° C.) while stirring with air rotation at 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) As a result, a milky white uniform polyolefin resin aqueous dispersion S-1 was obtained. Various characteristics of the aqueous dispersion are shown in Table 2.

Reference Example 6
(Preparation of aqueous polyolefin resin dispersion S-2)
As the polyolefin resin, an ethylene-acrylic acid copolymer {manufactured by Dow Chemical Company, Primacol 5980I, ethylene / acrylic acid = 80/20 (mass ratio)} was used.
Using a stirrer equipped with a heat-resistant 1-liter glass container with a heater, 60.0 g of polyolefin resin (Primacol 5980I), 17.7 g of triethylamine (manufactured by Wako Pure Chemical Industries, Ltd.), and 222.3 g Distilled water was charged into a glass container and stirred at a rotational speed of the stirring blade of 300 rpm. As a result, precipitation of resin particles was not observed at the bottom of the container, and it was confirmed that it was in a floating state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 120 ° C. and further stirred for 60 minutes. Then, after putting in a water bath and cooling to room temperature (about 25 ° C.) while stirring at a rotational speed of 300 rpm, pressure filtration (air pressure 0.2 MPa) with a 300 mesh stainless steel filter (wire diameter 0.035 mm, plain weave) As a result, a slightly cloudy aqueous dispersion S-2 was obtained. Various characteristics of the aqueous dispersion are shown in Table 2.

  The properties of the polyolefin resin dispersions E-1 to 4 and S-1 to 2 are shown in Table 2.

Reference Example 7
(Preparation of candelilla wax dispersion W-1)
40.0 g of Candelilla wax (manufactured by Toa Kasei Co., Ltd., acid value: 15.8, saponification value: 55.4), 8 .8 g (2.0 times equivalent of the amount required for complete neutralization and saponification of wax) and 151.2 g of distilled water were charged in a glass container, and the stirring blade was rotated. When the speed was stirred at 400 rpm, no resin precipitation was observed at the bottom of the container, confirming that it was in a floating state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. Then, the system temperature was kept at 100 ° C. and further stirred for 10 minutes. Then, after cooling to room temperature (about 25 degreeC), stirring by air cooling with a rotational speed of 600 rpm, the pale yellow uniform wax aqueous dispersion W-1 was obtained. The solid content concentration was 20.0% by mass, and the number average particle size was 0.27 μm.

Example 1
Aqueous polyolefin resin dispersion E-1 and natural wax aqueous dispersion W-1 were blended so as to be 87/13 (solid content mass ratio) to obtain an aqueous moisture-proof coating agent J-1. After applying a predetermined amount of the pot life of the water-based moisture-proof coating agent J-1 and J-1 to various substrate films and drying, the moisture resistance, the thickness of the coating, the transparency, and the heat sealability are evaluated. went.

Examples 2-4
Aqueous moisture-proof coating agent was prepared in the same manner as in Example 1 except that the ratio of polyolefin resin to natural wax was 97/3, 75/25, 65/35 (solid content mass ratio). Moisture-proof coating agents J-2 (Example 2), J-3 (Example 3), and J-4 (Example 4) were prepared, and various physical properties were evaluated.

Examples 5-7
In preparing the aqueous moisture-proof coating agent, water-based moisture-proof coating agents J-5 to J-7 were prepared in the same manner as in Example 1 except that E-2 to E-4 were used as the aqueous polyolefin resin dispersion. The physical properties were evaluated.

Example 8
In the preparation of the aqueous moisture-proof coating agent, an aqueous paraffin wax dispersion (manufactured by Nippon Seiki Co., Ltd., EMUATAR-0135, containing an anionic surfactant) was used as the wax dispersion. A moisture-proof coating agent J-8 was prepared, and various physical properties were evaluated.

  The results of Examples 1-8 are shown in Table 3.

Comparative Example 1
In preparing the aqueous moisture-proof coating agent, the candelilla wax dispersion W-1 was not added. That is, various physical properties were evaluated using the polyolefin resin aqueous dispersion E-1 alone.

Comparative Example 2
In the preparation of the aqueous moisture-proof coating agent, an aqueous moisture-proof coating agent H-2 was prepared in the same manner as in Example 1 except that the ratio of the polyolefin resin to the wax was 50/50 (solid content mass ratio). Various physical properties were evaluated.

Comparative Examples 3 and 4
In the preparation of the aqueous moisture-proof coating agent, the same procedure as in Example 1 was conducted except that S-1 (Comparative Example 3) and S-2 (Comparative Example 4) were used as aqueous polyolefin resin dispersions other than the polyolefin resin (A). Aqueous coating agents H-3 and H-4 were prepared and various physical properties were evaluated.

Comparative Example 5
Aqueous moisture-proof coating agent was prepared in the same manner as in Example 1 except that a polyethylene wax aqueous dispersion (manufactured by Nippon Seiki Co., Ltd., EMUATAR-0443, containing an anionic surfactant) was used as the wax dispersion. Coating agent H-5 was produced and various physical properties were evaluated.

Comparative Example 6
In preparation of water-based moisture-proof coating agent, NeoRez R-972 (manufactured by Enomoto Kasei Co., Ltd., acrylic resin aqueous dispersion, solid content concentration: 42.0% by mass) diluted twice with water as an aqueous resin dispersion A water-based moisture-proof coating agent H-6 was prepared in the same manner as in Example 1 except that was used, and various physical properties were evaluated.

  The results of Comparative Examples 1 to 6 are shown in Table 4.

  In Examples 1-8, what was excellent in moisture-proof property and transparency was obtained irrespective of the kind of base film. When the addition amount of the wax was small, there was a tendency for the moisture resistance to decrease (Example 2). However, the moisture resistance with no problem in practicality was observed when a very small amount was added. Moreover, the tendency for moisture-proof property to fall a little under the influence of surfactant used in the case of water-izing of polyolefin resin was recognized (Example 7). The heat sealability for various substrates was also good. Also in this case, the heat sealability tended to be slightly lowered due to the influence of the surfactant used in making the polyolefin resin aqueous (Example 7).

On the other hand, Comparative Example 1 did not express moisture resistance because it did not contain natural wax. In Comparative Example 2, the amount of natural wax added was outside the range of the present invention, so the moisture resistance was good but the transparency and heat sealability were poor. In Comparative Examples 3 and 4, since the polyolefin resin was outside the scope of the present invention, moisture resistance was hardly exhibited. In Comparative Example 5, since the wax used was different from the natural wax defined in the present invention, the moisture resistance was poor. In Comparative Example 6, since an acrylic resin outside the scope of the present invention was used as the resin, the moisture resistance was inferior and the heat sealability was hardly exhibited.

Claims (10)

Unsaturated hydrocarbons having 3 to 6 carbon atoms, and ethylene component becomes by copolymerizing an unsaturated carboxylic acid unit, 50 to 99.5 wt% unrealized unsaturated hydrocarbon of the 3 to 6 carbon atoms A polyolefin resin (A) having an acid value of 5 to 100 mgKOH / g and a natural wax (B) in an aqueous medium, and a mass ratio of (A) to (B) (A) / (B) Is a moisture-proof coating agent having 99.5 / 0.5 to 60/40.   The moisture-proof coating agent according to claim 1, wherein the unsaturated hydrocarbon having 3 to 6 carbon atoms constituting the polyolefin resin (A) is propylene and / or butene. Claim 1 or 2 moisture-proof composition obtained by removing the medium from the moisture-proof coating agent according. The moisture-proof composition according to claim 3, wherein the water vapor transmission coefficient at 40 ° C and 100% RH is 150 g · µm / m ² · day or less. A moisture-proof processed product comprising a substrate and a moisture-proof layer comprising the moisture-proof composition according to claim 3 . The moisture-proof processed product according to claim 5 , wherein the substrate is a thermoplastic resin film. The moisture-proof processed product according to claim 6 , wherein the haze is 10% or less. The moisture-proof processed product according to claim 5 , wherein the substrate is paper. The moisture-proof processed product according to any one of claims 5 to 8, which is further laminated on the moisture-proof layer. An aqueous dispersion containing the polyolefin resin (A), the method for producing a moisture-proof coating agent according to claim 1, comprising the step of mixing the aqueous dispersion of natural wax (B).