JP2010006935A - Coating film and vapor-deposited film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating film for vapor deposition, which is excellent in oxygen- and water-vapor-barrier properties, particularly the water-vapor-barrier property, and is excellent in water resistance. <P>SOLUTION: The coating film has a coating layer which is obtained through a step of unidirectionally stretching an unstretched film made of a polymer resin composition, subsequently applying a water dispersion coating liquid of a polyurethane resin composition having a urethane ligand, a urea ligand and an acid group to the obtained stretched film and subsequently stretching the stretched film coated with the coating liquid in a direction perpendicular to the first stretching direction and a heat-treatment step. The coating layer has a water contact angle within the range of 50-100° and a three-dimensional surface roughness SRa of ≤0.040 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coating film used in the packaging field of foods, non-foods, and pharmaceuticals, and particularly relates to a film suitable for a film for vapor deposition.

Packaging materials used for foods, non-foods, and pharmaceuticals 1) Inhibit oxidation of proteins and oils 2) Maintain taste and freshness 3) Property to block oxygen, water vapor and other gases to maintain the efficacy of pharmaceuticals That is, it is required to have gas barrier properties.
Therefore, a polymer resin generally known to have a relatively high gas barrier property such as polyvinyl alcohol (hereinafter referred to as PVA), ethylene vinyl alcohol copolymer (EVOH), or polyvinylidene chloride resin (hereinafter referred to as PVDC). Films laminated with compositions have been used as packaging materials. In addition, films in which a metal such as aluminum is vapor-deposited on a film of a suitable polymer resin composition and those in which an inorganic oxide such as alumina or silica is vapor-deposited are generally used as packaging materials.
However, since the gas barrier laminate film using the above-described PVA and EVOH polymer resin composition has large temperature dependency and humidity dependency, the gas barrier property is lowered at high temperature or high humidity. In addition, since PVDC contains a large amount of chlorine in the coating, there is a problem in terms of waste treatment such as incineration and recycling.
In addition, the above-mentioned metal-deposited films and films deposited with inorganic oxides such as alumina and silica have very different physical properties such as mechanical properties, chemical properties, and thermal properties between the deposits and the resin films. For this reason, the inorganic thin film used for the gas barrier layer lacks portability and is vulnerable to manipulation and bending. Moreover, since the adhesiveness with a base material is bad, handling is required and there exists a problem which a crack generate | occur | produces at the time of post-processing of packaging materials, such as printing, a laminate, and a bag making, and gas barrier property falls remarkably. Furthermore, since the apparatus is formed by using a vacuum process, the apparatus is expensive, locally high temperature is formed in the forming process, the base material is damaged, additives such as low molecular weight parts or plasticizers are decomposed, degassed, etc. As a result, defects, pinholes, etc. may occur in the deposited layer. That is, conventional vapor deposition films have problems that they cannot achieve high gas barrier properties and are expensive in cost.
Moreover, on the coating film which consists of an anionic self-emulsification type polyurethane resin which contains the polyurethane resin which has the high density | concentration of urethane group and urea group and has an acid group, and (ii) polyamine compound in the base material. A gas barrier material formed by forming an inorganic vapor deposition layer has been proposed (see, for example, Patent Document 1), but further improvement in barrier properties is required.
JP-A-2005-139435

  An object of this invention is to provide the coating film for vapor deposition excellent in oxygen and water vapor | steam barrier property, especially water vapor | steam barrier property, and excellent in water resistance.

  In view of the above problems, the inventors have intensively studied to arrive at the present invention. That is, in the present invention, an unstretched film made of a polymer resin composition is stretched in one direction, and then an aqueous dispersion coating liquid of a polyurethane resin composition having urethane bond groups, urea bond groups, and acid groups is applied to the stretched film. After coating, it has a coating layer obtained through a step of stretching the stretched film coated with the coating solution in the previous stretching direction and the orthogonal direction and a heat treatment step, and has a thickness of 0.10 to 0.50 μm. The coating film is characterized in that the coating layer is laminated, the water contact angle of the coating layer is in the range of 50 ° to 100 °, and the three-dimensional surface roughness SRa is 0.040 μm or less.

  In this case, it is preferable that the temperature of the heat treatment step is in a range of 205 to 240 ° C.

  Furthermore, in this case, it is preferable that an inorganic thin film layer is deposited on the coating layer of the coating film.

Furthermore, in this case, it is preferable that the vapor transmission film has an oxygen permeability of 7 ml / m ² · day · MPa or less and a water vapor permeability of 1.0 g / m ² · day or less.

  In addition, as a method for producing a coated film of the present invention, after stretching an unstretched film made of polyethylene terephthalate in one direction, an aqueous dispersion coating liquid of a polyurethane resin composition having a urethane bond group, a urea bond group, and an acid group is used. After applying to the stretched film, it is preferable to stretch the stretched film coated with the coating solution in the previous stretching direction and the orthogonal direction, and then heat-treat at 220 to 240 ° C.

  By this invention, it is excellent in oxygen barrier property, water vapor | steam barrier property, especially water vapor | steam barrier property, and shows the outstanding water resistance, It can use as a coating film for vapor deposition.

  Hereinafter, embodiments of the gas barrier film of the present invention will be described.

[Base material layer]
The base material layer used in the present invention is, for example, a film obtained by melt-extruding an organic polymer and stretching, cooling, and heat setting in the longitudinal direction and / or the width direction as necessary. Polyamide represented by nylon 4,6, nylon 6, nylon 6,6, nylon 12, etc., polyester represented by polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6 mononaphthalate, polyethylene, polypropylene, polybutene, etc. In addition to the polyolefins represented by (1), polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, wholly aromatic polyamide, polyamideimide, polyimide, polyetherimide, polysulfone, polystyrene, polylactic acid and the like can be mentioned.
The base material layer in the present invention may be a laminated film. There are no particular limitations on the type of laminate, the number of laminations, the lamination method, and the like in the case of a laminated film, and any one of known methods can be selected according to the purpose.
Fine particles such as silica can be added to the film. About the manufacturing method of a base material layer, the existing methods, such as a co-extrusion method and a casting method, can be used.

[Coating layer]
A specific coating layer is laminated on at least one surface of the above-described base material layer.
As the specific coating layer, a polyurethane resin having excellent film strength and water resistance and excellent adhesion to the inorganic thin film layer is preferable.

The polyurethane resin used for the coating layer having the above-mentioned characteristics is a polyurethane resin having a high total concentration of urethane groups and urea groups and having an acid group as an essential component. Such a polyurethane resin can be obtained by reaction using the following various (A) polyisocyanate compounds, (B) polyol compounds, (C) polyhydroxy acids, and (D) chain extenders.
In particular, in order to increase the film strength and increase the water resistance, the polyurethane resin is dispersed in water or water with the (C) polyhydroxy acid, or with the (C) polyhydroxy acid or (D) chain extender, It is effective to make the polyurethane resin three-dimensional (crosslinked).
In particular, the (C) polyhydroxy acid is effective for heating after coating on a film, and is effective for making an aqueous or water-dispersible polyurethane resin.

  From the viewpoint of gas barrier properties, the total concentration of urethane groups and urea groups (urea groups) in the polyurethane resin is about 15 to 60% by mass, preferably about 25 to 60% by mass, and more preferably about 35 to 55% by mass. . The urethane group concentration and the urea group concentration are the molecular weight of the urethane group (59 g / equivalent) or the molecular weight of the urea group (primary amino group (amino group): 58 g / equivalent, secondary amino group (imino group): 57 g / Equivalent) is a value obtained by dividing the molecular weight of the repeating structural unit structure. In the case of using a mixture, the concentration of the urethane group and urea group can be calculated based on the charge base of the reaction components, that is, the use ratio of each component.

  Examples of the acid group of the polyurethane resin include a carboxyl group. The acid group may be located at the terminal or side chain of the polyurethane resin. This acid group is usually neutralizable with a neutralizing agent (base) and may form a salt with the base.

  The acid value of the polyurethane resin can be selected within a range where water solubility or water dispersibility can be imparted, and is usually 5 to 100 mgKOH / g, preferably 10 to 70 mgKOH / g (for example, 10 to 60 mgKOH / g), and more preferably 15 It is about -60 mgKOH / g (for example, 16-50 mgKOH / g).

  The repeating structural unit of the polyurethane resin of the present invention is derived from a polyisocyanate component, a polyhydroxy acid component, a polyol component or a chain extender component, and contains hydrocarbon rings (aromatic and non-aromatic hydrocarbon rings). . The ratio of the hydrocarbon ring unit in the repeating unit of the polyurethane resin is 10 to 70% by mass, preferably 15 to 65% by mass, and more preferably about 20 to 60% by mass.

  The number average molecular weight of the polyurethane resin can be selected from the range of about 800 to 1,000,000, preferably 800 to 200,000, more preferably about 800 to 100,000.

The polyurethane resin may be crystalline in order to enhance gas barrier properties. Moreover, the glass transition point of a polyurethane resin is about 100-200 degreeC, Preferably it is about 110-180 degreeC, More preferably, it is about 120-150 degreeC.
Other urethane resin components are not particularly limited as long as they do not impair the object of the present invention.

(A) Polyisocyanate compound The polyisocyanate compound includes aromatic polyisocyanate, araliphatic diisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, aliphatic polyisocyanate and the like. As the polyisocyanate compound, a diisocyanate compound is usually used.

  Examples of the aromatic diisocyanate include tolylene diisocyanate (2,4- or 2,6-tolylene diisocyanate or a mixture thereof) (TDI), phenylene diisocyanate (m-, p-phenylene diisocyanate or a mixture thereof), 4,4. -Diphenylcyisocyanate, 1,5-naphthalene diisocyanate (NDI), diphenylmethane diisocyanate (4,4'-, 2,4'-, or 2,2'-diphenylmethane diisocyanate or mixtures thereof) (MDI), Examples include 4,4′-toluidine diisocyanate (TODI) and 4,4′-diphenyl ether diisocyanate.

  Examples of the araliphatic diisocyanate include xylylene diisocyanate (1,3- or 1,4-xylylene diisocyanate or a mixture thereof) (XDI), tetramethylxylylene diisocyanate (1,3- or 1,4-tetramethyl). Examples thereof include xylylene diisocyanate or a mixture thereof (TMXDI) and ω, ω′-diisocyanate-1,4-diethylbenzene.

  Examples of the alicyclic diisocyanate include 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate), 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (iso Holo isocyanate, IPDI), methylene bis (cyclohexyl isocyanate) (4,4 ′, 2,4′- or 2,2′-methylene bis (cyclohexyl isocyanate)) (hydrogenated MDI), methylcyclohexane diisocyanate (methyl-2,4- Cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate), bis (isocyanate methyl) cyclohexane (1,3- or 1,4-bis (isocyanate) Netomechiru) cyclohexane or mixtures thereof) (hydrogenated XDI) and the like.

  Examples of the aliphatic diisocyanate include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate), hexamethylene. Examples thereof include diisocyanate, pentamethylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl caffeate.

As the polyisocyanate compound (A), it is preferable to use a polyisocyanate compound containing a compound having a hydrocarbon ring. Examples of such compounds include aromatic, araliphatic and alicyclic polyisocyanates (particularly diisocyanates).
More specifically, among the diisocyanate components, the aromatic diisocyanate is preferably TDI, MDI, NDI, the araliphatic diisocyanate is preferably XDI, TMXDI, and the alicyclic diisocyanate is IPDI, hydrogenated. XDI, hydrogenated MDI and the like are preferable.
From the viewpoint of film coating properties, araliphatic diisocyanates (XDI, TMXDI, etc.) and alicyclic diisocyanates (IPDI, hydrogenated XDI, hydrogenated MDI, etc.) are preferred, and XDI, hydrogenated XDI, etc. are particularly preferred. . These polyisocyanate compounds can be used alone or in combination of two or more.

In particular, the xylylene group-containing urethane resin used in the present invention is preferably produced by using xylylene diisocyanate (XDI) and hydrogenated xylylene diisocyanate (hydrogenated XDI) as a polyisocyanate compound which is one of raw materials. . Thereby, oxygen barrier property and water vapor barrier property can be improved.
The xylylene group contained in xylylene diisocyanate (XDI) and hydrogenated xylylene diisocyanate (hydrogenated XDI) is a functional group having a high packing property, and as self-crosslinking progresses, it becomes a denser structure, thus improving barrier properties. It is estimated that it contributes to.
The combined use of xylylene diisocyanate and hydrogenated xylylene diisocyanate has the advantage of increasing the acid value and facilitating self-crosslinking.
The ratio of the total amount of xylylene diisocyanate (XDI) and hydrogenated xylylene diisocyanate (hydrogenated XDI) can usually be selected from a range of 10 to 100% by mass with respect to the whole polyisocyanate compound (A), and usually 20 to 100 mass% is preferable, More preferably, it is 25-100 mass%, Most preferably, it is 30-100 mass%.
The ratio of xylylene diisocyanate (XDI) and hydrogenated xylylene diisocyanate (hydrogenated XDI) is preferably 20% by mass or more of hydrogenated xylylene diisocyanate (hydrogenated XDI), based on the total of these. Preferably it is 40 mass% or more, Most preferably, it is 60% or more.

(B) Polyol compound As the polyol component (particularly the diol component), low molecular weight glycols to oligomers can be used, but usually from the viewpoint of gas barrier properties, alkylene glycol (for example, ethylene glycol, propylene glycol, trimethylene glycol). , 1,3-butanediol, 1,4-butanediol, pentanediol, hexanediol, neopentyl glycol, heptane diol, linear or branched _C 2 _{-C l0} alkylene glycols such as octanediol), (poly ) oxy C ₂ -C ₄ alkylene glycol (diethylene glycol, triethylene glycol, tetraethylene glycol, low molecular weight glycols such as dipropylene glycol, etc.) are used. Preferred glycol components are C ₂ -C ₈ polyol components [eg C ₂ -C ₆ alkylene glycol (especially ethylene glycol, 1,2- or 1,3-propylene glycol, 1,4-butanediol, 1,6 - hexanediol, 3-methyl-1,5-pentanediol), etc.], a di- or Toriokishi _C 2 -C ₃ alkylene glycol (diethylene glycol, triethylene glycol, dipropylene glycol, etc.), particularly preferred diol component _{C 2} - C ₈ is alkylene glycols (especially _C 2 -C ₆ alkylene glycol).

These diol components can be used alone or in combination of two or more. Further, if necessary, aromatic diols (for example, bisphenol A, bisbidoxetyl terephthalate, catechol, resorcin, hydroquinone, 1,3- or 1,4-xylylenediol or a mixture thereof), alicyclic diols Low molecular weight diol components such as hydrogenated bisphenol A, hydrogenated xylylene diol, cyclohexanediol, cyclohexane, dimethanol, etc. may be used in combination.
Furthermore, if necessary, a tri- or higher functional polyol component, for example, a polyol component such as glycerin, trimethylolethane, or trimethylolpropane can be used in combination.
Does the polyol component contain at least a C2-C8 polyol component? ? ? ? ? Preferred from the viewpoint of, further preferably includes a C2-C6 alkylene glycol, in particular including the _C 2 -C ₄ alkylene glycol preferred.
The ratio of the C ₂ -C ₈ polyol component to the entire polyol component can be selected from the range of about 50 to 100% by mass, and is usually 70% by mass or more and 100% by mass or less, preferably 80% by mass or more and 100% by mass or less. More preferably, it is 90 mass% or more and 100 mass% or less.

(B) Polyhydroxy acid As polyhydroxycarboxylic acid (particularly dihydroxycarboxylic acid), dihydroxy C ₂ -C ₁₀ alkane-carboxylic acid such as dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolhexanoic acid, etc. , alkane dihydroxy _C 4 _{-C 10,} such dioxy maleic acid - alkene polycarboxylic acids or dihydroxy _C 4 _{-C 10} - polycarboxylic acids, arene dihydroxy _C 6 _{-C 10,} such as 2,6-dihydroxybenzoic acid -A carboxylic acid etc. can be illustrated. These polyhydroxy acids can be used alone or in combination of two or more. Preferred polyhydroxy acids are polyhydroxyalkanecarboxylic acids, in particular dihydroxyalkanoic acids, for example dihydroxy C ₂ -C ₈ alkane-carboxylic acids.

  The polyhydroxy acid may be used in the form of a salt. Examples of polyhydroxy acid salts include ammonium salts, amine salts (such as trialkylamine salts), metal salts (such as sodium salts), and the like.

(D) Chain extender A polyamine can be used as the chain extender, and usually a nitrogen-containing compound having an active hydrogen atom, particularly a diamine is used.

Examples of the diamine component as a chain extender include aliphatic amines (for example, ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4 , 4-trimethyl hexamethylene diamine, etc. _{C 2-10} alkylenediamine such as octamethylenediamine), aromatic amines (e.g., m- or p- phenylene diamine, 1,3- or 1,4-xylylenediamine or its Mixtures), alicyclic amines (such as hydrogenated xylylenediamine, bis (4-aminocyclohexyl) methane, isophoronediamine, bis (4-amino-3-methylcyclohexyl) methane), hydroxyl group-containing diamines (2 -[(2-amino Ethyl) amino] ethanol, 2-aminoethylaminopropanol, amino C _2-6 alkylamino C _2-3 alkyl alcohols such as 3-aminopropylaminoethanol), acid group-containing diamines (for example, 3,4-diaminobenzoic acid) Diamino aromatic carboxylic acid such as acid, diaminosulfonic acid such as 1,3-phenylenediamine-4,6-disulfonic acid, 2,4-diaminotoluene-5-sulfonic acid, and the like.

Among these chain extenders, from the viewpoint of gas barrier properties, a chain extender having 8 or less carbon atoms (C ₂ -C ₈ ) is usually preferable in terms of facilitating self-crosslinking, and further C ₂ -C _6. low molecular weight chain extenders, for example, diamines (e.g., ethylene diamine, tetramethylene diamine, pentamethylene diamine, alkylenediamines C ₂ -C ₆ such as hexamethylenediamine, 2-amino-ethylamino ethanol, xylylenediamine) Are preferable, and those of C ₂ -C ₄ are particularly preferable. In addition, the chain extender can use a polyamine component more than trifunctional together as needed.

If necessary, in the preparation of a polyurethane resin, a compound having a reactive group with respect to an isocyanate group, such as an acid anhydride (for example, maleic anhydride, phthalic anhydride, succinic anhydride, trimellitic anhydride, Obtained by the reaction of a compound having a reactive group with respect to an isocyanate group (dihydroxy compound such as diol, diamine, etc.) or a compound having a carboxyl group, or a compound having these carboxyl groups. Oligoester polyols; oxysulfonic acid (for example, 2-oxyethanesulfonic acid, phenolsulfonic acid, etc.), sulfocarboxylic acid (for example, sulfobenzoic acid, sulfosuccinic acid, 5-sulfoisophthalic acid, etc.), amino group-containing sulfonic acid (For example, sulfanilic acid Etc.) compound having a sulfonic acid group, such as, or a compound oligoester polyols obtained by copolymerizing with these sulfonic acid groups; polyoxy C ₂ -C ₄ alkylene compound containing a reactive group to isocyanate group (e.g., A compound containing 30% by mass or more of an ethylene oxide unit and having a number average molecular weight of about 300 to 10,000) or an oligoester ether polyol obtained by copolymerizing these polyoxyalkylene compounds may be used.

Since the above-mentioned polyurethane resin prepares an aqueous solution in which the polyurethane resin is dissolved or an aqueous dispersion in which the polyurethane resin is dispersed in water, the acid groups of the polyurethane resin are neutralized with a neutralizing agent or a base. Neutralizing agents include conventional bases such as organic bases [eg, tertiary amines (tri-C ₁ -C ₄ alkylamines such as trimethylamine and triethylamine, dimethylethanolamine, methyldiethanolamine, triethanolamine, triethanolamine, Alkanolamines such as isopropanolamine, heterocyclic amines such as morpholine)], inorganic bases [ammonia, alkali metal hydroxides (lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.), alkaline earth metal hydroxides (Magnesium hydroxide, calcium hydroxide, etc.), alkali metal carbonates (sodium carbonate, potassium carbonate, etc.)]. These bases can be used alone or in combination of two or more.

In particular, from the viewpoint of coating properties and barrier properties after inorganic deposition, volatile bases, for example, tri-C ₁ -C ₃ alkylamines such as triethylamine, alkanolamines such as dimethylethanolamine, and ammonia are preferable. When a volatile base (such as a base selected from ammonia and amines) is used as a neutralizing agent, crosslinking of the polyurethane resin can be promoted by the polyamine compound (ii), which is useful for improving the barrier properties after inorganic vapor deposition. is there.

  The degree of neutralization with the neutralizing agent may be, for example, 30 to 100%, preferably 50 to 100%, particularly about 75 to 100%.

  The aqueous polyurethane resin composition is usually composed of the polyurethane resin, a neutralizing agent, and an aqueous medium. Examples of the aqueous medium include water, water-soluble or hydrophilic solvents (for example, alcohols such as ethanol and isopropanol; Examples thereof include ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; cellosolves; carbitols; nitriles such as acetonitrile), or a mixed solvent thereof. The aqueous medium is usually water or an aqueous solvent containing water as a main component.

  The polyurethane resin may be in any form of an aqueous solution dissolved in an aqueous medium or an aqueous dispersion dispersed in an aqueous medium. In the aqueous dispersion, the particle diameter of the dispersed particles (polyurethane resin particles) is not particularly limited, and may be, for example, an average particle diameter of 20 to 500 nm, preferably 25 to 300 nm, more preferably about 30 to 200 nm.

  The production method of the polyurethane resin or the composition thereof is not particularly limited, and the polyurethane resin can be prepared by using a usual polyurethane water-based technology such as an acetone method or a prepolymer method. In the urethanization reaction, a urethanization catalyst such as an amine catalyst, a tin catalyst, or a lead catalyst may be used as necessary. For example, in an inert solvent (a ketone such as acetone, an ether such as tetrahydrofuran, a nitrile such as acetonitrile, etc.), a polyisocyanate compound (A) and a polyhydroxy acid (B) and, if necessary, a polyol component (C) and / or Alternatively, the polyurethane resin can be prepared by reacting with the chain extender component (D). More specifically, a polyisocyanate compound (A), a polyhydroxy acid (B), and a polyol component (C) are reacted in an inert organic solvent (particularly, a hydrophilic or water-soluble organic solvent) to form a terminal isocyanate group. The aqueous polyurethane resin is produced by adding a chain extender component (D) and reacting it by removing the organic solvent after neutralizing with a neutralizer and dissolving or dispersing in an aqueous medium. Can be prepared.

  The ratio of the polyisocyanate compound (A) to the total amount of the polyhydroxy acid (B), the polyol component (C) and the chain extender component (D) can be selected within a range that does not impair the gas barrier properties. The total amount of active hydrogen atoms of each component (B), (C) and (D) is 0.5 to 1.5 mol, preferably 0.7 to 1.3 mol, more preferably 1 mol of the isocyanate group of Is about 0.8 to 1.2 mol. Further, among the compounds (B), (C) and (D), the ratio (molar ratio) of the hydroxyl group of the polyhydroxy acid (B) to the hydroxyl group of the polyol component (C) is the former / the latter = 100 / It is 0-5 / 95, preferably 80 / 20-5 / 95, more preferably about 60 / 40-10 / 90. The ratio (molar ratio) between the total hydroxyl groups of the polyhydroxy acid (B) and the polyol component (C) and the active hydrogen atoms (particularly amino groups) of the chain extender component (D) is the former / the latter = 100/0 to 10 / 90, preferably 100/0 to 25/75, more preferably about 95/5 to 40/60.

  Further, if necessary, it is optional to add various known inorganic and organic additives such as an antistatic agent, a slip agent, and an antiblocking agent to the coating layer as long as the present invention is not hindered. .

As a method of forming the coating layer on the substrate, a method of coating the substrate with an aqueous solution is usually employed as described above. The coating method is selected according to the coating amount and viscosity of the coating liquid to be used, and may be adopted from the fountain bar coating method or the like.
Although the preferable coating method is mentioned below, it is not limited to this.

As a solvent for the coating liquid, it is preferable to use 100% water or a water / lower alcohol mixed solvent from the viewpoint of solubility of the polyurethane resin. The lower alcohol is an alcoholic compound having a linear or branched aliphatic group having 1 to 3 carbon atoms, and specific examples include methyl alcohol, ethyl alcohol, ethylene glycol, n- or iso-propyl alcohol. It is done. Isopropyl alcohol is particularly preferable. The total solid concentration of the coating liquid of the present invention is preferably 2 to 35% by mass, and usually 5 to 30% by mass.
By using a water / lower alcohol mixed solvent, the dispersibility of the polyurethane resin, the uniformity of the coat, and the safety during production can be satisfied.

The conditions of drying and heat treatment during coating depend on the thickness of the coating layer and the conditions of the equipment, but after applying the coating solution after the stretching process in the running direction of the film, it is immediately sent to the stretching process in the perpendicular direction. By drying in the preheating zone and the stretching zone in the perpendicular stretching process and further heating in the heat treatment process, self-crosslinking can proceed simultaneously with the surface orientation and crystallization of the urethane resin containing metaxylylene groups and hydrogenated xylylene groups. preferable.
For this reason, the temperature of the normal preheating zone is 50 to 100 ° C., 105 to 140 ° C. in the stretching zone, and 205 to 240 ° C. in the heat treatment step.

  In addition, it is effective to improve the barrier property, particularly the water vapor barrier property, by setting a high temperature condition for drying and heat treatment after applying the coating liquid after the stretching process in the running direction of the film. In particular, it is preferable to set the temperature condition of the heat setting zone high. The temperature conditions for drying and heat treatment are formed on the substrate made of the polymer resin composition by an in-line coating method, and therefore must be within the range of the substrate temperature condition of the polymer resin composition. In the case of temperature conditions that have a large adverse effect such as a decrease in strength of the base material made of the molecular resin composition, oxygen barrier properties and water vapor barrier properties will not be fully developed, so care must be taken not to raise the temperature too high. It is.

In the case of producing a coating film for vapor deposition using a metaxylylene group and a hydrogenated xylylene group-containing urethane resin as a coating layer, a specific example using a polyethylene terephthalate resin composition as a polymer resin composition for a base film will be described. By setting the temperature condition of the heat setting zone high, sufficient heat is applied and the self-crosslinking of the urethane resin containing the metaxylylene group and hydrogenated xylylene group of the coating layer proceeds sufficiently, and the surface adsorbs less water. Since it becomes hydrophobic, the water contact angle of the coating layer is in the range of 50 ° to 100 °, water resistance is improved, and oxygen barrier properties and water vapor barrier properties are improved. Preferably it is the range of 50 degrees-70 degrees.
However, if the temperature condition of the heat setting zone is too high, the strength of the base material made of the polymer resin composition is significantly reduced, resulting in surface roughness on the base material, and the coating layer is also affected, resulting in surface roughness. To do. Therefore, the water contact angle of the coating layer is less than 50 °, and the oxygen barrier property and the water vapor barrier property are deteriorated.
On the other hand, if the temperature condition of the heat setting zone is low, the surface is rough because the heat is not sufficiently applied and the self-crosslinking of the metaxylylene group and hydrogenated xylylene group-containing urethane resin of the coating layer does not proceed sufficiently and the reaction is insufficient. Will occur. Further, since the heat is not sufficiently applied, the surface becomes hydrophilic while the amount of adsorbed water on the surface remains large, and the contact angle of water of the coating layer is less than 50 °, so that the oxygen barrier property and the water vapor barrier property are deteriorated.
If the water contact angle of the coating layer exceeds 100 °, the hydrophobicity of the coating layer surface becomes too strong, and sufficient adhesion to the inorganic vapor deposition layer cannot be obtained.
Further, the three-dimensional surface roughness SRa of the surface of the coating layer needs to be 0.040 μm or less, and if it exceeds 0.040 μm, the surface transparency becomes poor and the surface of the coating layer becomes rough, and after the deposition It will adversely affect the barrier properties. Preferably, it is 0.035 μm or less.
From the viewpoint of handleability of the coating film, it is preferably 0.010 μm or more.
Therefore, the temperature range of the heat setting zone is preferably set to 205 to 240 ° C, more preferably 220 to 238 ° C, and particularly preferably 231 to 237 ° C.

  If necessary, the base film may be subjected to an anchor treatment using a corona discharge treatment, other surface activation treatment or a known anchor treatment agent before forming the coating layer.

  The thickness of the coating layer is required to be 0.10 to 0.50 [mu] m, particularly preferably 0.10 to 0.30 [mu] m, from the viewpoint of gas barrier properties and economy. When the thickness of the coating layer is less than 0.10 μm, the coating layer is too thin, so that the oxygen barrier property, particularly the water vapor barrier property, is not sufficiently exhibited. On the other hand, when the thickness of the coating layer exceeds 0.50 μm, heat is not sufficiently applied, and the self-crosslinking of the metaxylylene group and hydrogenated xylylene group-containing urethane resin of the coating layer does not proceed sufficiently, resulting in insufficient reaction and surface roughness. It will occur. Further, not only the gas barrier property is lowered, but also the production cost is increased and the economy is deteriorated.

[Inorganic thin film deposition layer]
An inorganic thin film layer is deposited on the coating layer as described above. This inorganic thin film layer improves the gas barrier property, and as the material of the inorganic thin film, metals such as Al, Si, Ti, Zn, Zr, Mg, Sn, Cu, Fe, oxides of these metals, nitriding And specific examples include SiOx (x = 1.0 to 2.0), alumina, magnesia, zinc sulfide, titania, zirconia, cerium oxide, or a mixture thereof. Is done. The inorganic thin film layer may be a single layer or a laminate of two or more layers.
The film thickness of the inorganic thin film layer is preferably 10 to 5000 mm, more preferably 50 to 2000 mm. A film thickness of less than 10 mm is not preferred because sufficient gas barrier properties may not be obtained. On the other hand, if it exceeds 5,000 mm, the corresponding effect is not achieved, the bending resistance is lowered, and the manufacturing cost is disadvantageous, which is not preferable.
As a method for depositing the inorganic thin film layer, a known method, for example, a physical vapor deposition method such as a vacuum deposition method, a sputtering method or an ion plating method, a chemical vapor deposition method such as PECVD, or the like is employed.

  In the vacuum deposition method, metals such as aluminum, silicon, titanium, magnesium, zirconium, cerium, and zinc are used as the deposition material, and SiOx (x = 1.O to 2.0), alumina, magnesia, zinc sulfide, titania, Compounds such as zirconia and mixtures thereof are used. As the heating method, resistance heating, induction heating, electron beam heating or the like is employed. Alternatively, reactive vapor deposition using oxygen, nitrogen, hydrogen, argon, carbon gas / water vapor, or the like as a reactive gas, ozone addition, ion assist, or the like may be employed. Further, a method such as applying a bias to the base material, heating or cooling may be employed. The vapor deposition material, reaction gas, bias application, heating / cooling can also be employed in the sputtering method and the CVD method.

It is preferable that the thickness of the coating film and vapor deposition film of this invention is normally used with a packaging material, and it is preferable that it is 5-50 micrometers. Desirably, the thickness of a coating film and a vapor deposition film is 10-30 micrometers. The gas barrier film produced in this way is very excellent in oxygen barrier property and water vapor barrier property. The oxygen permeability is 7 ml / m ₂ · day · MPa or less, and the water vapor permeability is 1.0 g / m ² · day or less.

  In addition, since the coating film for vapor deposition and vapor deposition film of this invention are normally used as a packaging material, the heat-sealable resin layer called a sealant is often formed on an inorganic thin film layer. The heat-sealable resin layer is usually formed by an extrusion lamination method or a dry lamination method. The thermoplastic polymer that forms the heat-sealable resin layer may be any one that can sufficiently exhibit sealant adhesion, such as polyethylene resins such as HDPE, LDPE, and LLDPE, PP resin, ethylene-vinyl acetate copolymer, An ethylene-α olefin random copolymer, an ionomer resin, or the like can be used.

  The following examples illustrate the present invention in more detail. The characteristics shown in the examples were measured by the following methods.

1) Oxygen permeability About the oxygen permeability of the created film, after adjusting the temperature and humidity for 3 hours under the conditions of 23 ° C and 85% RH, use an oxygen permeability measuring device (OX-TRAN100 manufactured by Modern Controls). It was measured.

2) Water vapor transmission rate The water vapor transmission rate of the prepared film was adjusted for 3 hours under conditions of 40 ° C. and 90% RH, and then a measuring device (PARMATRAN-W) manufactured by Mocon, USA was used. Measured.

3) Measurement of contact angle Water is deposited on the coating layer of the coating film of the present invention with a contact angle meter (model: CAM200, sales company: Altec Alto Corporation, manufacturing company: KSV Instruments, Philland), and the contact angle is measured. Was measured. The contact angle was read at 5 seconds after water was deposited. As the analysis software, FAMAS (Kyowa Interface Science Co., Ltd.) was used. Detailed conditions for the measurement are shown below.
Temperature and humidity: 23 ° C, 35%
Measuring method: Liquid method (■ / 2 method)
Droplet size: 7.0 μL
Needle thickness: 22G, inner diameter 0.4mm

4) Intrinsic Viscosity of PET Phenol / 1, 1, 2, 2-tetrachloroethane (60) according to “Plastics—Determination of viscosity of polymer diluted solution using capillary viscometer” described in JIS K 7367-5 / 40; parts by mass) was measured at 30 ° C.

Example 1
[Manufacture of coating liquid]
MXDI (metaxylylene diisocyanate) 45.59, hydrogenated XDI (1,3-bis (isocyanatomethyl) cyclohexane) 93.9 g, ethylene glycol 24.8 g, dimethylolpropionic acid 13.4 g and methyl ethyl ketone 80.2 g as solvent Were mixed and reacted at 70 ° C. for 5 hours under a nitrogen atmosphere. Next, this carboxyl group-containing urethane prepolymer solution was neutralized with 9.6 g of triethylamine at 40 ° C. This polyurethane prepolymer solution was dispersed in 624.8 g of water with a homodisper, subjected to a chain extension reaction with 21.1 g of 2-[(2-aminoethyl) amino] ethanol, and methyl ethyl ketone was distilled off to obtain a solid content. An aqueous dispersion type polyurethane resin A having 25% by mass and an average particle diameter of 90 nm was obtained. The acid value of this resin is 26.9 mgKOH / g, and the total of the urethane group concentration and the urea group concentration is 39.6% by mass. This was diluted with water to obtain a coating solution having a solid content of 30% by mass.

[Manufacture of coated film]
PET containing an intrinsic viscosity of 0.62 and 700 ppm of finely divided silica is pre-crystallized and then dried, extruded at 280 ° C. using an extruder having a T-die, and rapidly cooled and solidified on a drum having a surface temperature of 40 ° C. A regular sheet was obtained. Next, the obtained sheet was stretched 4.0 times at 100 ° C. in the longitudinal direction between the heating roll and the cooling roll.
On the other hand, the coating liquid containing the metaxylylene group and hydrogenated xylylene group-containing urethane resin was put into a temperature control tank connected with a fountain for discharging the liquid onto the film surface and controlled at 25 ° C. while stirring. A clean liquid obtained by separating foreign substances through a 30p-hole polypropylene capsule filter was coated with the fountain on one side of the obtained uniaxially stretched film under the condition of a discharge amount of 0.028 m ³ / min. . Thereafter, a smooth bar having a diameter of 14 mm was applied to the liquid surface, the coating liquid was scraped off, and coating was performed so that the thickness of the coating layer after stretching was 0.20 μm. The coating speed (film forming speed) is 150 m / min. Next, the film was led to a drying zone (tenter), and the solvent was volatilized and dried at a preheating temperature of 100 ° C. Then, the film was stretched 4.0 times in the transverse direction at a temperature of 120 ° C., and while performing relaxation in the transverse direction of 6%, the temperature of the heat setting zone was set to 225 ° C. to perform heat setting treatment. The treatment time at each temperature was 3 seconds at a preheating temperature of 100 ° C., 5 seconds at a stretching temperature of 120 ° C., and 8 seconds at a heat fixing treatment temperature of 225 ° C. Thereafter, the mixture was cooled to obtain a biaxially stretched polyester film having a thickness of 12 μm.
After cooling, both edges were cut and removed, thereby continuously forming a biaxially stretched polyester film having a thickness of 12 μm over 1000 m to produce a mill roll. The obtained mill roll was slit into a width of 400 mm and a length of 1000 m, and wound around a 3-inch paper tube to obtain a coated film of the present invention.

[Manufacture of evaporated film]
Next, using this film roll for vapor deposition, various metals or metal oxides were vapor-deposited on the coated surface side of the film.
As a deposition source, particulate SiO ₂ (purity 99.99%) and Al ₂ O ₃ (purity 99.9%) having a size of 3 to 5 mm are used, and the film roll for deposition obtained as described above is covered. On the layer surface side, a mixed thin film of aluminum oxide and silicon dioxide was formed by electron beam evaporation. The vapor deposition material was divided into two without being mixed. An EB gun was used as a heating source, and each of Al ₂ O ₃ and SiO ₂ was heated in a time-sharing manner. Each material was heated so that the emission current of the EB gun at that time was 1.2 A and the composition ratio of Al ₂ O ₃ and SiO ₂ was 45:55. The film feed rate was 30 m / min, and a 20 nm thick film was formed. Moreover, the pressure at the time of vapor deposition was adjusted to 1 × 10 ⁻² Pa. Moreover, the temperature of the roll for cooling the film at the time of vapor deposition was adjusted to -10 degreeC.
About these, the oxygen permeability, the water vapor permeability, and the contact angle of water were measured by the methods and conditions shown at the beginning of the examples. Table 1 shows the evaluation results.

(Example 2)
After coating the coating liquid of Example 1, the film was led to a drying zone (tenter), and the solvent was volatilized and dried at a preheating temperature of 100 ° C. Then, the film was stretched 4.0 times in the transverse direction at a temperature of 120 ° C., and while performing relaxation in the transverse direction of 6%, the temperature of the heat setting zone was set to 205 ° C. to perform heat setting treatment. The treatment time at each temperature was 3 seconds at a preheating temperature of 100 ° C., 5 seconds at a stretching temperature of 120 ° C., and 8 seconds at a heat fixing treatment temperature of 205 ° C., but is not limited to this treatment time. Thereafter, the mixture was cooled to obtain a biaxially stretched polyester film having a thickness of 12 μm.
A sample was prepared and evaluated in the same procedure as in Example 1 except that the temperature of the heat setting zone was changed. Table 1 shows the evaluation results.

(Example 3)
After coating the coating liquid of Example 1, the film was led to a drying zone (tenter), and the solvent was volatilized and dried at a preheating temperature of 100 ° C. Then, the film was stretched 4.0 times in the transverse direction at a temperature of 120 ° C., and while performing relaxation of 6% in the transverse direction, the temperature of the heat setting zone was set to 215 ° C. to perform heat setting treatment. The treatment time at each temperature was 3 seconds at a preheating temperature of 100 ° C., 5 seconds at a stretching temperature of 120 ° C., and 8 seconds at a heat fixing treatment temperature of 215 ° C., but is not limited to this treatment time. Thereafter, the mixture was cooled to obtain a biaxially stretched polyester film having a thickness of 12 μm.
A sample was prepared and evaluated in the same procedure as in Example 1 except that the temperature of the heat setting zone was changed. Table 1 shows the evaluation results.

Example 4
After coating the coating liquid of Example 1, the film was led to a drying zone (tenter), and the solvent was volatilized and dried at a preheating temperature of 100 ° C. Then, the film was stretched 4.0 times in the transverse direction at a temperature of 120 ° C., and while performing relaxation of 6% in the transverse direction, the temperature of the heat setting zone was set to 235 ° C. to perform heat setting treatment. The treatment time at each temperature was 3 seconds at a preheating temperature of 100 ° C., 5 seconds at a stretching temperature of 120 ° C., and 8 seconds at a heat setting treatment temperature of 235 ° C., but is not limited to this treatment time. Thereafter, the mixture was cooled to obtain a biaxially stretched polyester film having a thickness of 12 μm.
A sample was prepared and evaluated in the same procedure as in Example 1 except that the temperature of the heat setting zone was changed. Table 1 shows the evaluation results.

(Example 5)
The coating was performed so that the thickness of the coating layer of Example 1 was 0.10 μm.
Samples were prepared and evaluated in the same procedure as in Example 1 except that the thickness of the coating layer was changed. Table 1 shows the evaluation results.
(Example 6)
The coating was performed so that the thickness of the coating layer of Example 1 was 0.50 μm.
A sample was prepared and evaluated in the same procedure as in Example 1 except that the thickness of the coating layer was changed. Table 1 shows the evaluation results.

(Comparative Example 1)
Samples were prepared and evaluated in the same procedure as in Example 1 except for the absence of the coating layer. Table 1 shows the evaluation results.
(Comparative Example 2)
The coating solution was coated with water-soluble polymer polyvinyl alcohol (PVA).
A sample was prepared and evaluated in the same procedure as in Example 1 except that the coating solution was changed. Table 1 shows the evaluation results.

(Comparative Example 3)
After coating the coating liquid of Example 1, the film was led to a drying zone (tenter), and the solvent was volatilized and dried at a preheating temperature of 100 ° C. Then, the film was stretched 4.0 times in the transverse direction at a temperature of 120 ° C., and while performing relaxation of 6% in the transverse direction, the temperature of the heat setting zone was set to 200 ° C. to perform heat setting treatment. The treatment time at each temperature was 3 seconds at a preheating temperature of 100 ° C., 5 seconds at a stretching temperature of 120 ° C., and 8 seconds at a heat fixing treatment temperature of 200 ° C. Thereafter, the mixture was cooled to obtain a biaxially stretched polyester film having a thickness of 12 μm.
A sample was prepared and evaluated in the same procedure as in Example 1 except that the temperature of the heat setting zone was changed. Table 1 shows the evaluation results.

(Comparative Example 4)
After coating the coating liquid of Example 1, the film was led to a drying zone (tenter), and the solvent was volatilized and dried at a preheating temperature of 100 ° C. Then, the film was stretched 4.0 times in the transverse direction at a temperature of 120 ° C., and while performing relaxation in the transverse direction of 6%, the temperature of the heat setting zone was set to 243 ° C. to perform heat setting treatment. The treatment time at each temperature was 3 seconds at a preheating temperature of 100 ° C., 5 seconds at a stretching temperature of 120 ° C., and 8 seconds at a heat setting treatment temperature of 240 ° C. Thereafter, the mixture was cooled to obtain a biaxially stretched polyester film having a thickness of 12 μm.
A sample was prepared and evaluated in the same procedure as in Example 1 except that the temperature of the heat setting zone was changed. Table 1 shows the evaluation results.

(Comparative Example 5)
The coating was performed so that the thickness of the coating layer of Example 1 was 0.05 μm.
Samples were prepared and evaluated in the same procedure as in Example 1 except that the thickness of the coating layer was changed. Table 1 shows the evaluation results.
(Comparative Example 6)
The coating was performed so that the coating layer of Example 1 had a thickness of 0.55 μm.
Samples were prepared and evaluated in the same procedure as in Example 1 except that the thickness of the coating layer was changed. Table 1 shows the evaluation results.

  According to the present invention, a film for vapor deposition that is extremely excellent in oxygen barrier properties and water vapor barrier properties, is excellent in water resistance, and does not contain dioxin and hydrogen chloride gas in incineration exhaust gas, and is effective for environmental conservation economically. Can be provided. The vapor deposition film using the coating film of the present invention can be widely used as a packaging material for foods, electronic materials and the like, and greatly contributes to the industry.

Claims (5)

  After stretching an unstretched film made of a polymer resin composition in one direction, after applying an aqueous dispersion coating solution of a polyurethane resin composition containing a urethane bond group, a urea bond group, and an acid group to the stretched film, A coated film obtained by subjecting a stretched film coated with the coating solution to a stretching process and a heat treatment process in a stretching direction and a perpendicular direction, and a water contact angle of the coating layer in a range of 50 ° to 100 °. And a three-dimensional surface roughness SRa of 0.040 μm or less.   It is a coating film of Claim 1, Comprising: The temperature of the said heat processing process is the range of 205-240 degreeC, The coating film characterized by the above-mentioned.   A vapor deposition film, wherein an inorganic thin film layer is vapor-deposited on the coating layer of the coating film according to claim 1. It is the vapor deposition film of Claim 3, Comprising: The oxygen permeability of the said vapor deposition film is 7 ml / m < ² > * day * MPa or less, Water vapor | steam permeability is a value of 1.0 g / m < ² > * day or less, It is characterized by the above-mentioned. Vapor deposition film.   After stretching an unstretched film made of polyethylene terephthalate in one direction, a water-dispersed coating liquid of a polyurethane resin composition having a urethane bond group, a urea bond group, and an acid group is applied to the stretched film, and then the coating liquid is used. A method for producing a coated film, wherein the applied stretched film is stretched in the previous stretching direction and the orthogonal direction and then heat-treated at 205 to 240 ° C.