JP2006298968A - Moistureproofing coating agent, moistureproof composition, moistureproof film, and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moistureproofing coating agent which imparts moistureproofness to various substrates and to provide an article which uses the coating agent, is made moistureproof by a method advantageous in economy and resource saving, and copes with practical and environmental problems. <P>SOLUTION: The moistureproofing coating agent is one comprising a urethane, a wax, and a liquid medium, wherein 10 to 1,000 pts.mass wax is contained per 100 pts.mass urethane. The waterproofing composition is the coating agent devoid of the liquid medium. The moistureproof processed article or the moistureproof film is obtained by applying this to a substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a moisture-proof coating agent imparting excellent moisture-proof property, a moisture-proof composition obtained by coating the moisture-proof coating agent, a moisture-proof film obtained by laminating the moisture-proof composition on a film, and a moisture-proof film excellent in productivity. It relates to a manufacturing method.

  Thermoplastic resin films such as polyethylene terephthalate (hereinafter abbreviated as “PET”) and nylon 6 (hereinafter abbreviated as “Ny6”) are excellent in mechanical properties and optical properties. Widely used as packaging film. In such an application, when packaging a product that dislikes moisture, a process of imparting moisture resistance to the film is performed.

  As a method for imparting moisture resistance to a film, a method of adding a wax to a resin as a base material to form a film is known (Patent Document 1). However, this method has a problem in that film properties such as mechanical properties and solvent resistance are impaired because a large amount of wax is mixed with the base material.

  In addition, a technology to develop moisture resistance and pinhole resistance by applying a coating agent containing urethane resin, vinyl chloride-vinyl acetate copolymer and polyethylene wax to the outer surface of polyamide film provided with an inorganic oxide vapor deposition layer Is disclosed (Patent Document 2). However, in this technique, improvement in moisture resistance is achieved by the inorganic vapor deposition film, and the coating agent containing wax is used for the purpose of protecting pinholes in the inorganic vapor deposition film and preventing blocking of the film surface. Therefore, the added amount of wax in the coating agent was extremely low.

  Furthermore, for the purpose of imparting moisture resistance and blocking resistance to a biaxially stretched polypropylene film, it is disclosed that a topcoat agent comprising a vinylidene chloride copolymer to which liquid paraffin or paraffin wax is added on both sides of the film is disclosed. (Patent Document 3). In this technology, liquid paraffin or paraffin wax becomes a lamellar dispersion in a vinylidene chloride copolymer, and moisture resistance is expressed with a small amount of wax. This method is not applicable to chemicals, and since this method contains vinylidene chloride, harmful gas may be generated during incineration, which is not preferable from the viewpoint of the environment.

  On the other hand, as a technique for forming a coating film containing a urethane resin on the polyamide film surface, after applying a liquid containing a urethane resin, a melamine resin, and a crosslinking catalyst, the film is stretched to impart easy adhesion to the film ( Patent Document 4) and a slippery layer made of a blend of a polyurethane copolymer and an acrylic polymer and a polyolefin wax are laminated on a polyamide film to impart slipperiness in a high humidity atmosphere. (Patent Document 5) is not intended to express moisture resistance, and the latter technique is intended for easy slipping, and the amount of wax added is small. .

JP-A-9-194706 JP 2001-205761 A JP-A-8-134242 JP 11-34259 A JP-A-9-248886

  Under the background as described above, the present invention applied a moisture-proof coating agent capable of imparting moisture resistance by a method with excellent productivity without impairing the properties of the substrate, and this moisture-proof coating agent. An object is to provide a moisture-proof composition, a moisture-proof film, and a method for producing the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors applied a moisture-proof coating agent containing a urethane resin, a wax and a liquid medium to the substrate, thereby preventing moisture-proofing without impairing the properties of the substrate. Based on this finding, the present invention was reached.

That is, the gist of the present invention is as follows.
(1) A moisture-proof coating agent containing 100 parts by mass of a urethane resin, 10 to 1000 parts by mass of a wax, and a liquid medium.
(2) The moisture-proof coating agent according to (1), further comprising at least one compound selected from the group consisting of melamine compounds, isocyanate compounds, oxazoline group-containing compounds and epoxy compounds.
(3) The moisture-proof coating agent according to (1) or (2), wherein the liquid medium is water or an aqueous medium.
(4) The moisture proof according to any one of (1) to (3), wherein at least one selected from the group consisting of candelilla wax, paraffin wax, microcrystalline wax and Fischer-Tropsch wax is used as the wax. Coating agent.
(5) A liquid medium is removed from the moisture-proof coating agent according to any one of (1) to (4), and the water vapor transmission coefficient at 40 ° C. and 100% RH is 200 g · μm / m ² / day or less. A moisture-proof composition characterized by being.
(6) A moisture-proof processed product provided with a layer of the moisture-proof composition according to (5) on the surface of the substrate.
(7) A moisture-proof processed product obtained by impregnating a substrate with the moisture-proof composition according to (5).
(8) A moisture-proof film provided with the layer of the moisture-proof composition according to (5) on the surface of a thermoplastic resin film.
(9) The moisture-proof film according to (8), wherein the moisture-proof composition layer has a thickness of 0.01 to 5 μm.
(10) The moisture-proof film according to (8) or (9), wherein the thermoplastic resin is polyamide.
(11) A method for producing a moisture-proof film, wherein the coating agent according to any one of (1) to (4) is applied to at least one surface of an unstretched film and then dried at a temperature equal to or higher than the melting point of the wax.
(12) A method for producing a moisture-proof film, wherein the coating agent according to any one of (1) to (4) is applied to at least one surface of an unstretched film and then simultaneously biaxially stretched.
(13) A moisture-proof film characterized in that, after longitudinally stretching an unstretched film, the coating agent according to any one of (1) to (4) is applied to at least one surface of the longitudinally stretched film and then laterally stretched. Production method.

  According to the moisture-proof coating agent of the present invention, it is possible to provide moisture-proof properties to various substrates in an economically and resource-saving manner, and to produce a moisture-proof composition and a moisture-proof film that are practical and environmentally friendly. Can do. Further, by using a polyamide resin film as a base material, moisture resistance can be imparted while taking advantage of mechanical properties such as puncture resistance, pinhole resistance, and impact resistance of the polyamide resin film. Furthermore, when the moisture-proof layer is formed, the moisture-proof property can be effectively expressed by drying at a temperature equal to or higher than the melting point of the wax.

  Hereinafter, the present invention will be described in detail.

  The moisture-proof coating agent of the present invention comprises a urethane resin, a wax and a liquid medium.

  The urethane resin used in the present invention is a polymer containing a urethane bond in the main chain, and is obtained, for example, by a reaction between a polyol compound and a polyisocyanate compound. In the present invention, the structure of the polyurethane resin is not particularly limited, but from the viewpoint of blocking resistance, the glass transition temperature is preferably 30 ° C. or higher, more preferably 50 ° C. or higher, and particularly preferably 60 ° C. or higher.

  The polyol component constituting the urethane resin is not particularly limited, and examples thereof include water, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,2-propanediol, 1 , 3-propanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, methyl-1,5-pentanediol, 1,8-octanediol, 2-ethyl-1,3-hexane Low molecular weight glycols such as diol, diethylene glycol, triethylene glycol and dipropylene glycol, low molecular weight polyols such as trimethylolpropane, glycerin and pentaerythritol, polyols having ethylene oxide and propylene oxide units Compounds, polyether diols, high molecular weight diols such as polyester diols, bisphenols such as bisphenol A, bisphenol F, dimer diol or the like carboxyl group was converted to a hydroxyl group of the dimer acid.

  As the isocyanate component, one or a mixture of two or more known polyisocyanates of aromatic, aliphatic and alicyclic groups can be used. As the polyisocyanate, trifunctional or higher functional polyisocyanates such as triphenylmethane triisocyanate and polymethylene polyphenyl isocyanate and diisocyanates can be used, and diisocyanates are preferably used. Specific examples of the diisocyanate include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthylene diisocyanate, isophorone diisocyanate, dimaryl diisocyanate, lysine. Examples thereof include diisocyanate, hydrogenated 4,4′-diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, dimerized isocyanate obtained by converting a carboxyl group of dimer acid to an isocyanate group, and adducts, biurets, and isocyanurates.

  Moreover, the molecular weight of a urethane resin can also be adjusted suitably using a chain length extension agent. Examples of such compounds include compounds having two or more active hydrogens such as amino groups and hydroxyl groups capable of reacting with isocyanate groups. For example, diamine compounds, dihydrazide compounds, and glycols can be used.

  Examples of the diamine compound include ethylenediamine, propylenediamine, hexamethylenediamine, triethyltetramine, diethylenetriamine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, and the like. Other examples include diamines having a hydroxyl group such as N-2-hydroxyethylethylenediamine and N-3-hydroxypropylethylenediamine, and dimer diamine obtained by converting the carboxyl group of dimer acid into an amino group. Furthermore, diamine type amino acids such as glutamic acid, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid and diaminobenzenesulfonic acid are also included.

  Dihydrazide compounds include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacin dihydrazide, etc., saturated aliphatic dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, etc. And unsaturated dihydrazides such as itaconic acid dihydrazide and phthalic acid dihydrazide, carbonic acid dihydrazide, carbodihydrazide, and thiocarbodihydrazide.

  As glycols, they can be appropriately selected from the aforementioned polyols.

  Specific examples of the wax used in the present invention include 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, paraffin Examples thereof include petroleum waxes such as wax and microcrystalline wax, and synthetic waxes such as Fischer-Tropsch wax and polyethylene wax. Of these, candelilla wax, carnauba wax, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax are preferred because they exhibit excellent moisture resistance when mixed with urethane. Paraffin wax, candelilla wax, microcrystalline wax, and Fischer-Tropsch wax are preferred. Is more preferable. The melting point of the wax is preferably 50 ° C. or higher, more preferably in the range of 80 to 100 ° C.

  The blending ratio of the urethane resin and the wax in the moisture-proof coating agent of the present invention is such that the wax is 10 to 2000 with respect to 100 parts by mass of the urethane resin in order to maintain the expression of moisture resistance and the transparency and strength of the moisture-proof composition layer. It is necessary to set it as a mass part, Preferably it is 20-500 mass parts, More preferably, it is 30-150 mass parts. If it is less than 10 parts by mass, the moisture resistance is not sufficiently exhibited. On the other hand, when the amount of the wax exceeds 2000 parts by mass, the moisture-proof composition layer becomes cloudy or brittle, and the adhesion with the substrate is lowered. In some cases, moisture resistance may deteriorate.

  The liquid medium of the moisture-proof coating agent of the present invention is not particularly limited, and may be an organic solvent or water or a mixture of water and a hydrophilic solvent, but is liquid at room temperature and normal pressure, Those which volatilize by heating or reduced pressure are preferred. Examples of organic solvents include diethyl ketone (3-pentanone), methyl propyl ketone (2-pentanone), methyl isobutyl ketone (4-methyl-2-pentanone), 2-hexanone, 5-methyl-2-hexanone, and 2-to. Ketones such as butanone, 3-heptanone, 4-heptanone, cyclopentanone, cyclohexanone, aromatic hydrocarbons such as toluene, xylene, benzene, Solvesso 100, Solvesso 150, butane, pentane, hexane, cyclohexane, heptane , Aliphatic hydrocarbons such as octane and nonane, ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, diethyl carbonate , Γ-butyrolactone, isophorone, etc. S, and the like hydrophilic organic solvent to be described later in addition.

  The liquid medium is preferably an aqueous medium from the standpoints of storage stability, ease of handling, environmental protection, resource saving, regulation of dangerous goods by the Fire Service Act, and workplace environment improvement. An aqueous medium is a medium composed of a liquid mainly composed of water. As the solvent other than water, a hydrophilic organic solvent is preferably used, and specific examples thereof include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n -Amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether , Alcohols such as ethylene glycol monopropyl ether and ethylene glycol monobutyl ether, ethers such as tetrahydrofuran and 1,4-dioxane, acetone, methyl ethyl ketone, etc. Tons, methyl acetate, n-propyl acetate, isopropyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate, dimethylformamide, dimethylacetamide, diacetone alcohol, acetonitrile, etc. Including ammonia, diethylamine, triethylamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N-diethanolamine, 3-methoxypropylamine, 3-diethylaminopropylamine, dimethylaminopropylamine And organic amine compounds such as

  The state in which urethane and wax are contained in the above liquid medium is a state in which both components are dissolved in the liquid medium, either component is dispersed in the liquid medium as fine particles, and the other is dissolved in the liquid medium. State in which both components are dispersed as fine particles in a liquid medium, and any state may be taken depending on the combination of urethane, wax, and liquid medium, but storage stability and easy handling For reasons such as environmental protection, a so-called aqueous dispersion state in which both urethane and wax are dispersed as fine particles in water or an aqueous medium is particularly preferable. Such an aqueous dispersion can be easily obtained by preparing an aqueous dispersion of each component of the urethane resin and wax, and mixing them in a predetermined blending amount. For mixing, a liquid / liquid mixing apparatus is appropriately used. Since the dispersibility is good, a simple mixing operation can be performed for a very short time.

  In order to dissolve or disperse a urethane resin in an aqueous medium, an anionic group such as a carboxyl group or a sulfonic acid group, a nonionic group such as a silanol group or a hydroxyl group, or a cationic group such as an amino group is introduced into the urethane resin. It is preferable to do. In this way, a water-soluble urethane or a self-emulsifying urethane aqueous dispersion can be obtained. Moreover, it can also be set as the forced emulsification type urethane aqueous dispersion using an emulsifier. Furthermore, an aqueous urethane dispersion having a self-crosslinking functional group can also be used. From the viewpoint of handling of the coating liquid and water resistance of the coating film, it is preferable to use a self-emulsifying urethane aqueous dispersion.

  Urethane resin aqueous dispersions can also be obtained as commercial products, such as Superflex 150, 300, 420, 460, 500, 550, 600, 830, E-4500, etc. manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. Takeda Chemical Co., Ltd. bamboo racks W-615, W-6010, W-6020, W-6061, W-7004, W-605, WS-7000, WS-5000, WS-5100, WS-4000, etc. Ink Chemical Industries, Ltd., Hydran HW-340, HW-150-140, AP-30, AP-40F, Boncoat CG-5000, etc. are mentioned. In addition, the solid content density | concentration of a commercially available urethane resin aqueous dispersion is 25-50 mass% normally.

  Methods for preparing an aqueous dispersion of wax include a method using an anionic dispersion stabilizer, and a method in which dispersion is stabilized by partially neutralizing acidic groups with a basic compound without using a dispersion stabilizer. The following two types can be exemplified. In general, the former method can be employed when the acid value of the wax is less than 5 mgKOH / g, and the latter method can be employed when the acid value is 5 mgKOH / g or more.

  When an aqueous dispersion of wax is prepared using an anionic dispersion stabilizer, a known aqueous method such as a phase inversion emulsification method may be used. For example, the wax is dissolved in an organic solvent, or By melting and liquefying, adding water with an anionic dispersion stabilizer added, and stirring with a general-purpose dispersion device such as a homomixer, homodisper, homogenizer, colloid mill, pebble mill, ultrasonic disperser, etc. It can be made aqueous.

  The addition amount of the dispersion stabilizer is preferably 0.001 to 20 parts by mass, more preferably 0.01 to 10 parts by mass, and particularly preferably 0.01 to 7 parts by mass with respect to 100 parts by mass of the wax. When the addition amount of the dispersion stabilizer exceeds 20 parts by mass, the water resistance of the resulting coating film may be lowered.

  Examples of the dispersion stabilizer include sulfate esters of higher alcohols, higher alkyl sulfonates, higher carboxylates, alkyl benzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, vinyl sulfosuccinates, etc. Can be mentioned.

  An aqueous wax dispersion not containing a dispersion stabilizer can be prepared by heating and stirring a wax, a basic compound, and an aqueous medium in a sealable container. According to this method, a stable aqueous dispersion can be obtained without using a high-speed stirring device such as a generally used homogenizer or homomixer. As the production apparatus, a known solid / liquid stirring apparatus or emulsifier can be used, and an apparatus capable of pressurization of 0.1 MPa or more is preferably used. The stirring method and the rotation speed of stirring are not particularly limited, but may be stirring at a low speed that allows the resin to float in the medium.

  Specifically, raw materials such as wax, basic compound, and aqueous medium are charged into the above apparatus, and then the temperature in the tank is 45 to 200 ° C, preferably 60 to 150 ° C, more preferably 80 to 120 ° C. While maintaining the temperature, preferably the wax is sufficiently dispersed by continuing stirring until coarse particles disappear (for example, 5 to 120 minutes), and then preferably cooled to 40 ° C. or lower with stirring, A dispersion can be obtained. 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.

  As specific examples of the basic compound, ammonia or an organic amine compound having a boiling point of 250 ° C. or lower is preferably used. Examples of organic amine compounds include diethylamine, triethylamine, diethanolamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N-diethanolamine, 3-methoxypropylamine, 3-diethylaminopropylamine, Examples thereof include dimethylaminopropylamine, morpholine, N-methylmorpholine, N-ethylmorpholine. It is particularly preferable to use triethylamine or morpholine because of excellent dispersion stability.

  An aqueous dispersion of wax is also available as a commercial product. For example, EMUSTAR-0135, 0443, 0413, 0454, 1055, 2090, 3085, 3115, 3115B, 5390, 5501, 5555, manufactured by Nippon Seiwa Co., Ltd., AQADISPA- 7415 etc. are mentioned.

  The moisture-proof coating agent of the present invention preferably contains a crosslinking agent in order to improve performance such as solvent resistance and adhesion to a substrate. The blending ratio of the cross-linking agent is preferably in the range of 0.1 to 50 parts by mass, more preferably in the range of 0.1 to 30 parts by mass with respect to 100 parts by mass of the urethane resin. When the addition amount is less than 0.1 parts by mass, the effect of addition is small, and when it exceeds 50 parts by mass, the adhesion with the film tends to be reduced. The crosslinking agent used in the present invention can be appropriately selected from the viewpoints of drying conditions and the storage stability of the coating agent. For example, isocyanate compounds, melamine compounds, urea compounds, epoxy compounds, carbodiimide compounds, oxazoline group-containing compounds, zirconium A salt compound or the like can be used. These crosslinking agents may be used alone or in combination of two or more. Methylolated melamine compounds such as trimethylol melamine and hexamethylol melamine, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether in terms of adhesion between the moisture-proof layer and the substrate film Glycidyl ether type epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, tolylene diisocyanate, diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, dicyclohexylmethane diisocyanate, etc. Isocyanate compounds are preferred . The isocyanate compound may be biuret type, adduct type or isocyanurate type, and may be used as a blocked isocyanate from the viewpoint of storage stability of the liquid. These cross-linking agents are preferably used in an aqueous medium from the standpoints of environmental protection, resource conservation, dangerous goods regulations by the Fire Service Act, workplace environment improvement, etc., and nonionics such as ethylene glycol and polyethylene glycol are used as necessary. Hydrophilic groups can also be introduced. Trimethylol melamine, hexamethylol melamine, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, polyethylene glycol diglycidyl ether, isophorone diisocyanate, hexamethylene diisocyanate, xylene diisocyanate are particularly preferred.

  Furthermore, in the moisture-proof coating agent of the present invention, organic and inorganic fillers, plate pigments, inorganic layered compounds, pigments, pigment dispersants, wetting agents, antifoaming agents, thickeners, as long as the characteristics are not impaired. Freezing and thawing stabilizer, coating film forming aid, preservative, antifungal agent, anticorrosive agent, plasticizer, antioxidant, ultraviolet absorber, radical scavenger, weathering agent, flame retardant, leveling agent, anti-waxing agent, etc. Can be added.

  The solid content concentration of the moisture-proof coating agent of the present invention is preferably in the range of 5 to 60% by mass, more preferably 5 to 50% by mass, and particularly preferably 5 to 40% by mass. If it is 5% by mass or less, it becomes difficult to coat a layer having a sufficient thickness to exhibit moisture resistance, and a problem that a long time is required in the subsequent drying step tends to occur. On the other hand, if it exceeds 60% by mass, there may be a problem in mixing operation and storage stability. The solid content concentration can be adjusted appropriately by distilling off or diluting the aqueous medium. Further, an organic solvent such as a low-boiling point alcohol (for example, ethanol) may be added in order to improve the coating performance and the mixing stability.

  Since the moisture-proof coating agent of the present invention is excellent in coating properties to various substrates, paper, synthetic paper, thermoplastic resin film, plastic product, metal such as steel plate and aluminum foil, wood, woven fabric, It can be applied to knitted fabrics, non-woven fabrics, gypsum boards, wooden boards, etc., and it can be applied to various substrates by laminating or impregnating the substrate with a moisture-proof composition obtained by removing the liquid medium from the coating agent. Moisture-proof processing can be applied.

  If a film is used for the substrate, a moisture-proof film can be obtained. Examples of the base film include PET, polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polyester resins such as polybutylene naphthalate, polyhydroxycarboxylic acids such as polyglycolic acid and polylactic acid, Polyurethane resins represented by aliphatic polyester resins such as poly (ethylene succinate) and poly (butylene succinate), polyamide resins such as nylon 6, nylon 66 and nylon 46, polyolefin resins such as polypropylene and polyethylene, polyimide resins, A film made of a thermoplastic resin such as a polyarylate resin or a mixture thereof or a laminate thereof can be mentioned. Among them, a film made of polyester or polyamide can be preferably used. When the film is pierced and strong, pinhole resistance and impact resistance are required, a polyamide film can be preferably used. A moisture-proof film using a polyamide film is suitable for a packaging bag of contents containing moisture.

  The base film may be an unstretched film or a stretched film, and its production method is not limited, and may be a so-called shrink film that shrinks by heating. 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. Usually, a packaging film having a thickness of 5 to 30 μm is preferably used. Moreover, it is preferable that the base film is subjected to corona discharge treatment. Moreover, silica, alumina, etc. may be vapor-deposited and other layers, such as a gas barrier layer, may be laminated | stacked.

  When the moisture-proof composition of the present invention is laminated on a substrate film to form a moisture-proof film, the moisture-proof composition is laminated on the surface of the substrate film, so that moisture resistance is not impaired without impairing the mechanical properties (for example, bending pinhole resistance) of the entire substrate. Sex can be imparted.

  Paper, synthetic paper, plastic products, steel plates and the like can be further laminated on the moisture-proof film. The surface on which these layers are laminated may be the moisture-proof composition side or the base film side of the moisture-proof film. Moreover, you may provide an adhesive layer as needed.

  As a method for producing a base film, for example, a thermoplastic resin is heated and melted with an extruder and extruded from a T die, and cooled and solidified with a cooling roll to obtain an unstretched film, or extruded from a circular die. Solidified by water cooling or air cooling to obtain an unstretched film. In the case of producing a stretched film, a method in which an unstretched film is once wound or continuously stretched by a simultaneous biaxial stretching method or a sequential biaxial stretching method is preferable. From the viewpoint of film mechanical properties and uniform thickness performance, a method of combining a flat film forming method using a T die and a tenter stretching method is preferable.

  When the moisture-proof coating agent is applied to the substrate prior to stretching, it is first applied to an unstretched film and dried, and then supplied to a tenter-type stretching machine to simultaneously stretch the film in the running direction and the width direction (simultaneously). (Biaxial stretching), heat treatment, or stretching in the running direction of the film using a multi-stage heat roll or the like, coating, drying, and stretching in the width direction with a tenter type stretching machine (sequential biaxial stretching) May be. It is also possible to combine stretching in the running direction and stretching with a tenter. Since the amount of heat for stretching the film can be used for drying and crosslinking of the coating agent, a moisture-proof film having excellent productivity can be obtained. Moreover, a thin film can be easily obtained by extending | stretching after application | coating.

  In order to improve the adhesion between the base film and the moisture-proof composition layer, the surface of the base film may be subjected to corona discharge treatment or anchor coating treatment.

  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.

  After the moisture-proof coating agent of the present invention is applied to the substrate, it is preferable to perform heat treatment. As the heat treatment method, a known method such as a non-contact type heat treatment device such as a hot air dryer, a vacuum dryer or an infrared heater or a contact type heat treatment device such as a hot roll or a heat press machine can be used. It can also be used in combination. Although the heat treatment temperature varies depending on the thermal efficiency of the apparatus used, it is preferable to perform the heat treatment at a temperature equal to or higher than the melting point of the wax contained in the moisture-proof coating agent. Further, in order to shorten the heat treatment time, heat treatment is preferably performed at 130 ° C. or higher, and heat treatment is preferably performed at 150 ° C. or higher. The heat treatment time is usually 1 second or longer, preferably 3 seconds or longer. If the heat treatment temperature is too low or the heat treatment time is too short, the moisture resistance may be insufficient.

  The thickness of the moisture-proof composition layer in the present invention is desirably at least 0.05 μm in order to sufficiently improve the moisture-proof property. From the viewpoint of moisture resistance, it is better that the moisture-proof composition layer is thick. However, since the feature of the present invention is to exhibit moisture resistance even if the moisture-proof composition layer is thin, it is not necessary to make it thick. The thickness of the preferable moisture-proof composition layer considering moisture resistance and economy is 0.05 to 5 μm, more preferably 0.1 to 2 μm, and particularly preferably 0.1 to 1 μm.

  In the present invention, another method (for example, laminating a moisture-proof film prepared in advance on a substrate) is performed by a method of forming a moisture-proof composition layer by applying a coating agent as described above. Compared to the above, a moisture-proof composition layer having a thickness of 5 μm or less can be formed on the substrate very easily.

The moisture resistance of the moisture-proof composition layer of the present invention can be evaluated by a water vapor transmission coefficient described later, and the value thereof is 200 g · μm / m ² / day or less. This value, for use in applications such as packaging material, preferably ^{100g · μm / m 2 / day} , 50g · μm / m , more preferably ^{2 / day, 20g · μm /} m 2 / day or less are more It is preferably 10 g · μm / m ² / day or less.

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) Thickness of moisture-proof composition layer It calculated | required by subtracting the thickness of a base film from the whole thickness of the moisture-proof processed film which laminated | stacked the moisture-proof composition layer on the film surface.
(2) Bend-resistant pinhole resistance A rectangular film of 20.3 mm × 27.9 mm conditioned under conditions of 20 ° C. and 65% RH is attached to a gelbo flex tester (manufactured by Rigaku Corporation). It rotated 440 degrees during 9 mm straight travel, and further traveled 6.4 mm straight, and then the movement until returning to the original position in the reverse stroke was counted as one time, and 10,000 bending tests were performed. With respect to the film after the bending test, a colored liquid (ageless seal check manufactured by Mitsubishi Gas Chemical Co., Inc.) was applied to one side of the film, and the number of penetrating liquids on the opposite side was measured as the number of pinholes (measurement area was 497 mm ² ).
(3) water vapor permeability, the water vapor permeability coefficient MOCON Co. of moisture permeability measuring device (PERMATRAN-W3 / 31MW), 40 ℃, measure the water vapor permeability of the moisture-proof processed film in 100% RH, and a _{Q F} . On the other hand, to measure the water vapor permeability of the base film, and the Q _B. Next, the thickness of the moisture-proof composition layer was determined from the difference in average thickness between the moisture-proof processed film and the base film, and was taken as L. It was calculated water vapor permeation coefficient P _C of the moisture-proof composition layer by the following equation from the above values.

_{1 / Q F = 1 / Q} B + L / P C
However, Q _F : Water vapor transmission rate of moisture-proof processed film (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)
Incidentally, _{Q B} of the PET film used as the substrate _{Q B} of ^59g / m 2 / day, Ny6 film was 603g ^/ m 2 ^/ day.

Reference example 1
(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, melting point 71) using a stirrer equipped with a heat-resistant 1 L glass container with a heater. ℃), 8.6 g (2.5 times equivalent of the amount required for complete saponification of wax) and 151.4 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
The candelilla wax dispersion W-1 is blended so that the wax component is 50 parts by mass with respect to 100 parts by mass of the resin component of the urethane aqueous dispersion (Mitsui Takeda Chemicals, Takelac WS-5100) U-1. A moisture-proof coating agent J-1 was obtained.

  After applying the obtained water-based moisture-proof coating agent J-1 to a film applicator (manufactured by Yasuda Seiki Seisakusho Co., Ltd., 542-AB) on one side of the base film, it is dried at 140 ° C. for 60 seconds. Thus, a moisture-proof film was prepared and evaluated for moisture-proof property, coating thickness, and resistance to bending pinholes. As the base film, a biaxially stretched Ny6 film (Emblem ON15 manufactured by Unitika Ltd.) having a thickness of 15 μm was used.

Example 2
A coating agent and a coated film were obtained in the same procedure as in Example 1, except that the base film was changed to a PET film (manufactured by Unitika Ltd., Emblet PET 12, thickness 12 μm).

Examples 3 and 4
In the preparation of the aqueous moisture-proof coating agent of Example 1, the addition amount of the candelilla wax dispersion W-1 is 20 parts by mass and 100 parts by mass of the wax component with respect to 100 parts by mass of the resin component of the urethane aqueous dispersion U-1. Except for blending so as to be parts, aqueous moisture-proof coating agents J-2 (Example 3) and J-3 (Example 4) were obtained in the same manner as Example 1. Various physical properties were evaluated using these.

Example 5
A Fischer-Tropsch wax dispersion (manufactured by Nippon Seiwa Co., Ltd., EMUSTAR-3085, containing an anionic surfactant, hereinafter abbreviated as “3085”, the melting point of the wax is 85 ° C.) is used as an aqueous wax resin dispersion. Using Daiichi Kogyo Seiyaku Co., Ltd. Superflex 460 (hereinafter abbreviated as “U-2”) as a body, blended with 100 parts by mass of the urethane resin component so as to be 50 parts by mass of the wax component, and further crosslinked. As an agent, 10 parts by mass of isocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Aquanate AQ100) was added to obtain an aqueous moisture-proof coating agent J-4. A moisture-proof film was produced in the same manner as in Example 1 except that this coating agent was used, and various physical properties were evaluated.

Example 6
As a wax dispersion, an aqueous microcrystalline wax dispersion (manufactured by Nippon Seiwa Co., Ltd., EMUSTAR-2090, containing an anionic surfactant, hereinafter abbreviated as “2090”, the melting point of the wax is 88 ° C.), an aqueous urethane dispersion As a hydran AP40 (hereinafter abbreviated as “U-3”) manufactured by Dainippon Ink & Chemicals, Inc., 100 parts by mass of the urethane resin component is blended so as to be 50 parts by mass of the wax component, and further a crosslinking agent. 10 parts by mass of melamine (manufactured by Mitsui Cytec Co., Ltd., Cymel 327) was added to obtain an aqueous moisture-proof coating agent J-5. A moisture-proof film was produced in the same manner as in Example 1 except that this coating agent was used, and various physical properties were evaluated.

Example 7
As a wax dispersion, an aqueous paraffin wax dispersion (manufactured by Nippon Seiwa Co., Ltd., EMUSTAR-0135, containing an anionic surfactant, hereinafter abbreviated as “0135”, the melting point of the wax is 61 ° C.) is used as an aqueous urethane dispersion. F-8583D (hereinafter abbreviated as “U-4”) manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd. is used and blended so that the wax component is 50 parts by mass with respect to 100 parts by mass of the resin component of the urethane resin, and further crosslinked. As an agent, 10 parts by mass of an epoxy compound (Nagase Kasei Kogyo Co., Ltd., Denacol EX313) was added to obtain an aqueous moisture-proof coating agent J-6. A moisture-proof film was produced in the same manner as in Example 1 except that this coating agent was used, and various physical properties were evaluated.

Example 8
Nylon 6 resin (Unitika Ltd., Unitika Nylon 6, A1030BRL) was used with an extruder equipped with a T die (slow compression type single screw with a 75 mm diameter and L / D of 45). Extruded into a sheet form at a temperature of 270 ° C., brought into close contact with a cooling roll adjusted to a surface temperature of 10 ° C., and rapidly cooled to obtain an unstretched film having a thickness of 150 μm.

  Subsequently, the unstretched film was led to a gravure roll type coater, and the coating agent J-1 shown in Example 1 was coated so that the coating thickness after drying was 7 μm (thickness after stretching 0.7 μm). It dried for 30 second in the hot air dryer of degreeC. Next, the film was supplied to a tenter simultaneous biaxial stretching machine, preheated at a temperature of 100 ° C. for 2 seconds, and then stretched at 170 ° C. at a magnification of 3 times in the machine direction and 3.5 times in the transverse direction. Next, heat treatment was performed at 200 ° C. for 15 seconds with a transverse relaxation rate of 5%, and a biaxially stretched film having a thickness of 15 μm was wound up.

Example 9
Except for using J-4 as the moisture-proof coating agent, a moisture-proof film was prepared in the same manner as in Example 8, and various physical properties were evaluated.

Example 10
In the preparation of the water-based moisture-proof coating agent of Example 5, the added amount of the Fischer-Tropsch wax dispersion W-1 is 120 parts by mass of the wax component with respect to 100 parts by mass of the resin component of the urethane aqueous dispersion U-1. It mix | blended and it was set as the water-based moisture-proof coating agent J-7. A moisture-proof film was prepared in the same manner as in Example 8 except that this coating agent was used, and various physical properties were evaluated.

Example 11
Except for using J-5 as the moisture-proof coating agent, a moisture-proof film was prepared in the same manner as in Example 8, and various physical properties were evaluated.

Example 12
An aqueous Fischer-Tropsch wax dispersion (manufactured by Nippon Seiwa Co., Ltd., EMUSTAR-3115, containing an anionic surfactant, hereinafter abbreviated as “3115”, the melting point of the wax is 115 ° C.) is used as the wax dispersion. As a cross-linking agent, 10 parts by mass of an epoxy compound (manufactured by Nagase Kasei Kogyo Co., Ltd., Denacol EX313) is added to 100 parts by mass of the urethane resin component. Thus, an aqueous moisture-proof coating agent J-8 was obtained.

  Nylon 6 resin was extruded into a sheet form at a cylinder temperature of 260 ° C and a T-die temperature of 270 ° C using an extruder equipped with a T-die (slow compression type single screw with a 75 mm diameter and L / D of 45), and the surface temperature It was made to contact | adhere on the cooling roll adjusted to 25 degreeC, and it cooled rapidly, and it was set as the unstretched film of thickness 155 micrometers.

  Subsequently, the unstretched film was longitudinally stretched 2.8 times at a temperature of 55 to 62 ° C. by a longitudinal stretching machine composed of a group of heating rollers having different peripheral speeds to obtain a longitudinally stretched film. Next, the moisture-proof coating agent J-8 was applied to one side of the longitudinally stretched film using a Mayer bar coater so that the thickness of the coated product after lateral stretching was 0.7 μm. Next, it is led to a tenter and treated in a preheating section at 60 ° C. for 5.3 seconds to substantially dry the water in the aqueous dispersion to form a coating film and preheat, and at 90 ° C. to 3.7 times The film was stretched horizontally and heat-set at 210 ° C. to obtain a moisture-proof coated film having a thickness of 15 μm. Various physical properties were evaluated.

Examples 13-14
In the preparation of the aqueous moisture-proof coating agent of Example 1, the addition amount of the candelilla wax dispersion W-1 was changed to 500 parts by mass of the wax component with respect to 100 parts by mass of the resin component of the urethane aqueous dispersion U-1. Example 13) A water-based moisture-proof coating agent J-9-11 was prepared and evaluated for various physical properties in the same manner as in Example 1 except that the amount was 1000 parts by mass (Example 14).

  The measurement results and the like obtained in Examples 1 to 14 are collectively shown in Table 1.

Comparative Example 1
In the preparation of the aqueous moisture-proof coating agent of Example 1, an aqueous moisture-proof coating agent H-1 was prepared in the same manner as in Example 1 except that the candelilla wax dispersion W-1 was not added, and various physical properties were evaluated. went.

Comparative Example 2
In preparing the aqueous moisture-proof coating agent of Example 1, the aqueous moisture-proof coating agent H was used in the same manner as in Example 1 except that a modified polyolefin aqueous dispersion (Unitika Ltd., Arrow Base SB-1200) was used as the resin aqueous dispersion. -2 was produced and various physical properties were evaluated.

Comparative Example 3
In the preparation of the water-based moisture-proof coating agent of Example 1, the addition amount of the candelilla wax dispersion W-1 is such that the wax component is 2000 parts by mass with respect to 100 parts by mass of the resin component of the urethane aqueous dispersion U-1. A water-based moisture-proof coating agent H-3 was prepared in the same manner as in Example 1 except that it was blended, and various physical properties were evaluated.

  The measurement results and the like obtained in Comparative Examples 1 to 3 are shown in Table 1.

  Regardless of the type of the base film from Examples 1 and 2, films excellent in moisture resistance and transparency were obtained.

  Even if the compounding ratio of urethane and wax was changed from Examples 1, 3, 4, 13, and 14, a product excellent in moisture resistance and bending pinhole resistance was obtained.

  From Examples 1, 5, 6, and 7, even when the types of the wax and the cross-linking agent were changed, those having excellent moisture resistance and bending pinhole resistance were obtained.

  From Examples 8, 9, 10, and 11, a moisture-proof film excellent in moisture resistance and bending pinhole property was obtained even when a moisture-proof coating agent was applied to an unstretched film and then biaxially stretched.

  From Example 12, a moisture-proof film excellent in moisture resistance and bending pinhole resistance was obtained even by a sequential biaxial stretching method in which a moisture-proof coating agent was applied after longitudinal stretching of the film and then stretched in the transverse direction.

On the other hand, Comparative Example 1 did not express moisture resistance because no wax was blended. Further, in Comparative Example 2, since the amount of the wax added was outside the range of the present invention, the coating film was cracked and the gas permeability could not be evaluated. In Comparative Example 3, the resin was outside the scope of the present invention and the moisture resistance was poor.

Claims (13)

A moisture-proof coating agent containing 100 parts by mass of a urethane resin, 10 to 1000 parts by mass of a wax, and a liquid medium. Furthermore, the moisture-proof coating agent of Claim 1 containing the at least 1 sort (s) of compound chosen from the group which consists of a melamine compound, an isocyanate compound, an oxazoline group containing compound, and an epoxy compound. The moisture-proof coating agent according to claim 1 or 2, wherein the liquid medium is water or an aqueous medium. The moisture-proof coating agent according to any one of claims 1 to 3, wherein at least one selected from the group consisting of candelilla wax, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax is used as the wax. A liquid medium is removed from the moisture-proof coating agent according to any one of claims 1 to 4, and a water vapor transmission coefficient at 40 ° C and 100% RH is 200 g · µm / m ² / day or less. Moisture-proof composition. A moisture-proof processed article, wherein the layer of the moisture-proof composition according to claim 5 is provided on the surface of the substrate. A moisture-proof processed product obtained by impregnating a substrate with the moisture-proof composition according to claim 5. A moisture-proof film provided with the layer of the moisture-proof composition according to claim 5 on the surface of a thermoplastic resin film. The moisture-proof film according to claim 8, wherein the moisture-proof composition layer has a thickness of 0.01 to 5 μm. The moisture-proof film according to claim 8 or 9, wherein the thermoplastic resin is polyamide. A method for producing a moisture-proof film, wherein the coating agent according to any one of claims 1 to 4 is applied to at least one surface of an unstretched film and then dried at a temperature equal to or higher than the melting point of the wax. A method for producing a moisture-proof film, wherein the coating agent according to any one of claims 1 to 4 is applied to at least one surface of an unstretched film and then simultaneously biaxially stretched. A method for producing a moisture-proof film, comprising: stretching a non-stretched film longitudinally, applying the coating agent according to any one of claims 1 to 4 to at least one surface of the longitudinally stretched film, and then stretching the film in the transverse direction.