JPH09290210A - Continuous production of coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly and thinly film-form a coating material having low viscosity level equal to that of water at high speed by extruding a coating composition having a specific viscosity at a specific temp. from a wide slit type discharge opening toward the surface of a traveling film base material to form a thin film having a specific thickness. SOLUTION: The coating composition having 0.1-100cp viscosity at 20 deg.C is extruded from the wide slit type discharge opening 2 toward the surface of the film base material 3 to form the thin film 4 having 0.1-20μm thickness. In such a case, the coating composition forms a gas barrier coating film and contains a vinylidene chloride resin. Since the low viscosity coating composition is continuously applied at high speed and receives no adverse effect caused by air or light before coating in this method, the method is suitable for the continuous coating of a hydrolyzing composition, an easily oxidizing composition or a photosetting composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing a coating film capable of continuously coating a low-viscosity coating composition as a uniform thin film on the surface of a film substrate at a high speed.

[0002]

2. Description of the Related Art Generally, a method of continuously forming a coating film on a film substrate is a roll coating method of coating a running film substrate through a roll,
It can be roughly divided into spray coating methods using a spray nozzle or the like. There are various roll coating methods, for example, a doctor blade coating method that controls the coating thickness using a doctor blade, an air knife coating method that controls the coating thickness with an air knife, and an engraved gravure roll. Direct gravure coating method,
Examples thereof include a reverse roll coating method using a number of counter-rotating rolls, a dip coating method in which a film is immersed in a coating liquid bath, a kiss coating, a squeeze coating, and the like.

In these roll coating methods, the coating material of relatively high viscosity is often applied directly onto the film substrate. On the other hand, when the viscosity of the coating material is relatively low, as shown in FIG. 3, a method of putting the coating liquid in a pan and applying the coating liquid to the film via an applicator roll is used.

[0004]

However, in the case of the method of putting the coating liquid in the pan, not all the coating liquid in the pan is coated, so that even if a gravure roll having a transfer rate of 90% is used, it is expensive. It is useless for a simple coating liquid. Further, there is a problem that the viscosity of an emulsion type coating liquid is too low and it is difficult to bring the coating liquid to the point of contact with the film by an applicator roll. Therefore, there is a method in which a viscosity modifier (leveling agent) is added to the coating liquid to increase the viscosity of the liquid until it becomes coatable. The use of the leveling agent is effective if the leveling agent does not adversely affect the properties of the obtained coating film, but when the dense gas barrier coating film is to be formed, the use of the leveling agent lowers the gas barrier property. May be invited. Furthermore, in the conventional coating method, the maximum coating speed for accurate coating is at most about 200 m / min, and a higher-speed coating method has been demanded.

In particular, when a gas barrier coating film is formed using an organometallic compound-based coating composition in which hydrolysis polycondensation proceeds due to moisture in the atmosphere, the roll is applied. Since the coating solution is always exposed to the atmosphere in the method, it cannot be adopted due to the disadvantages that the viscosity of the coating solution increases during coating, the solid content concentration changes, and gelation occurs. The spray coating method is a closed system and is effective when it is not necessary to form a dense film like an adhesive, but in order to form a gas barrier coating film, the uniformity of the obtained film
There was a problem of lack of continuity. This problem of inconvenience caused by exposure to the atmosphere also occurs in coating compositions that are easily oxidized and photocurable coating compositions.

Therefore, in the present invention, there is provided a method capable of uniformly thinning a low-viscosity coating material having the same level as that of water, and capable of continuously producing a coating material at a high speed even if the coating material causes inconvenience due to atmospheric exposure. Established as an issue.

[0007]

The method for continuously producing a coating film according to the present invention has a viscosity at 20 ° C. of 0.1-1.
The main point is that a coating composition of 00 cps is extruded from a wide slit-shaped discharge port toward the surface of a film substrate running to form a thin film of 0.1 to 20 μm. The method of the present invention is particularly effective when forming a gas barrier coating film in which a leveling agent cannot be used. The coating composition for forming a gas barrier coating film contains polyvinylidene chloride, or an organometallic compound-based composition, that is, an organometallic compound (I) represented by the following general formula and / or its hydrolysis. Those containing a condensate and a solvent R ¹ _m M (OR ² ) _n (I) (wherein M is a metal element, R ¹ may be the same or different, a hydrogen atom, a lower alkyl group, an aryl group) , A vinyl group or a mercapto group directly bonded to a carbon chain, or a (meth) acryloyl group, R ² may be the same or different, and represent a hydrogen atom, a lower alkyl group or an acyl group, and R ¹ and R ² may be substituted with any substituent, m is 0 or a positive integer, n is an integer of 1 or more, and m + n is the same as the valence of the metal element M).
Is preferably used. All or part of the organometallic compound (I) may be an organosilane compound having R ¹ substituted with an amino group.

When an organometallic compound-based coating composition is used, it is preferable to have an organic compound (II) having a primary and / or secondary amino group in the molecule in the composition. In particular, when the organic compound (II) is a polyethyleneimine, the obtained gas barrier coating film has excellent film-forming properties and other properties. At this time, the organometallic compound (I) may not have an amino group.

When the coating composition further contains a compound (III) having a functional group capable of reacting with an amino group (particularly an epoxy group) in the molecule, the film-forming property of the organometallic compound-based coating composition is obtained. The gas barrier property of the coating film and the coating film becomes excellent, which is a preferred embodiment. Further, when the compound (III) is a compound having a hydrolyzable group in addition to the functional group capable of reacting with the amino group, a higher performance gas barrier layer can be obtained.

The present invention also includes a coating film obtained by the continuous production method of the present invention. Especially for use as a gas barrier film, the oxygen permeability of the coating film is 20 ° C. and 80% RH,
It is preferably 20 cc / m ² · 24 hrs · atm or less.

It is also preferable that the coating film of the present invention has a surface smoothness of ± 25% or less. The surface smoothness is the degree of variation in the thickness (film thickness) of the coating film formed on the base material. This surface smoothness accuracy is within ± 25% means that when the film thickness is measured at multiple arbitrary points on the coating film and the average value is calculated, the measured values of the film thickness at each point are all average values. Is within the range of ± 25%, which is an index of the uniformity of the coating film thickness. In the case of ordinary use, if the surface smoothness is ± 25%, the uniformity of the coating film is sufficient. The coating film obtained by the continuous production method of the present invention exhibits excellent surface smoothness accuracy even if it is a thin film. Especially when used as an LCD display material, since the uniformity of the thickness of the coating film is important, it is recommended to use a coating film having a surface smoothness accuracy of within ± 10%, preferably within ± 3%.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The continuous production method of the present invention comprises applying a low-viscosity coating composition from a wide slit-shaped discharge port toward a film substrate surface running near the discharge port tip. It has a point in that it is extruded to form a film. When extruding, it is preferable to extrude while pressurizing by introducing a pump or nitrogen gas. 1 and 2 show side views for explaining the continuous manufacturing method of the present invention. In FIG. 1, the traveling direction of the film is from the bottom to the top of the drawing, and the ejection port is approached from just beside the film.
In FIG. 2, since the coating composition is discharged from the direction orthogonal to the tangent of the roll with which the film is in contact, the running direction of the film and the angle of the discharge port can be appropriately selected.

1 and 2, 1 is an extruder,
2 is a discharge port, 3 is a film base material, and 4 is a coating film. The extruding device 1 is not particularly limited, but for example, as a pressurizing means, a method of feeding an inert gas such as nitrogen gas or dry air containing no moisture with or without compression, a closed system or an open system. A method using a pump or the like can be adopted. In the case of an organometallic compound-based coating composition having a hydrolyzable group that easily reacts with moisture in the atmosphere, a coating composition that easily oxidizes, or a coating composition that cures when exposed to light, a sealed system extrusion It is recommended to use the device. 1 and 2, an example of a hermetically sealed system is shown as an extruder. Reference numeral 5 is a tank, and 6 is a gas introduction pipe. The width of the ejection port is appropriately selected according to the width of the film.

The coating composition used in the present invention has a low viscosity of 0.1 to 100 cps at 20 ° C. Even with such a low-viscosity composition, it is possible to obtain 0.1
A thin film in the range of up to 20 μm can be uniformly and accurately formed. The reason for setting the viscosity in the above range is 0.1
If it is lower than cps, it is difficult to form a uniform thin film even if the method of the present invention is applied, and if the viscosity is higher than 100 cps, another coating method can be applied. In order to effectively utilize the effect of the present invention that a low-viscosity composition can be applied uniformly and thinly, the composition has a viscosity of 1 to 50 cp.
It is preferably s. The more preferable upper limit of the viscosity is 2
0 cps. If the present invention is adopted, it is possible to improve the coating speed to a maximum level of 550 m / min. Usually, 10 to 550 m / min, preferably 30
~ 500 m / min, more preferably 50-450 m /
A coating speed of min is recommended.

Further, according to the method of the present invention, a desired amount of the coating material is directly placed on the film, and since it is not necessary to adjust the coating amount with a knife or a blade, the waste of the material is completely eliminated. Furthermore, if a sealing type extruder is used, the coating can be performed without being exposed to the atmosphere between the material tank and the discharge port. Therefore, the organometallic compound-based coating composition, the oxidizable coating composition or Even with a coating composition that is curable by light, continuous coating can be performed without the disadvantages of increasing the viscosity of the coating liquid, changing the solid content concentration, and gelling.

In the method of the present invention, the thickness of the coating film after drying depends on the solid content concentration of the coating composition, the running speed of the film substrate, the discharge port gap a, the film substrate and the discharge port tip. It is set appropriately according to the distance b. The preferable thickness of the coating film is 0.1 to 20 μm in a dry state.
It is. It is difficult to apply the coating thinner than 0.1 μm and uniformly, and pinholes are easily generated. On the other hand, it may be thicker than 20 μm, but cracks are likely to occur in the coating film. A more preferable lower limit value of the thickness is 0.5 μm,
The upper limit is 10 μm. 0 for gas barrier coatings.
The thickness is preferably 5 to 10 μm, more preferably 1
˜5 μm, more preferably 2 to 4 μm.

The coating film is dried by passing it through a heating furnace controlled to be heated at 40 ° C. or higher, following the coating process. The preferable heating temperature is appropriately set according to the heat resistance of the substrate film, but is usually 50
C. to 120C. When the coating material is an organometallic compound-based material, humidification of 5% RH or more is performed with or before heating in order to accelerate hydrolysis condensation polymerization of the coating film to form a dense film. It is preferable.

The material of the film substrate is not particularly limited, but for example, ethylene-vinyl alcohol copolymer; polyvinylidene chloride resin; polyolefin resin such as polyethylene and polypropylene; polyethylene terephthalate, polyethylene isophthalate, polyethylene-2. Polyester resins such as 1,6-naphthalate, polybutylene terephthalate and their copolymers; polyoxymethylene; polyamide resins; polystyrene, poly (meth) acrylic acid ester, polyacrylonitrile, polyvinyl acetate, polycarbonate, cellophane, polyimide , Thermoplastic resins such as polyetherimide, polyphenylene sulfone, polysulfone, polyether ketone, polyether sulfone, polyarylate, ionomer resin, fluororesin; Resins, thermosetting resins such as polyurethane resins, epoxy resins, phenol resins, unsaturated polyester resins, alkyd resins, urea resins, silicon resins, etc., which may contain known additives. It may be subjected to surface activation treatment such as treatment, or known anchor treatment such as urethane resin or polyethyleneimine. It is also possible to use paper.

The coating composition used in the method of the present invention is not limited to an aqueous solution type, an emulsion type, an organic solvent type and the like as long as it has a viscosity of 0.1 to 100 cps at 20 ° C. The type of coating composition is also not particularly limited, and has adhesiveness, magnetism, gloss, heat sealability,
It can be applied to various compositions for imparting various properties such as water resistance, chemical resistance, antistatic property, slipperiness, and releasability (release property), and various compositions such as undercoat agent. it can.

Particularly, the method of the present invention can be preferably used as a method for thinly and uniformly coating a relatively expensive gas barrier composition because the coating composition is not wasted and a uniform thin film can be continuously produced at high speed.

The composition for gas barrier is preferably selected from polyvinylidene chloride type, ethylene-vinyl alcohol copolymer type and organometallic compound type which have excellent gas barrier properties. The polyvinylidene chloride-based composition includes vinylidene chloride as a main component (60% by weight or more) and emulsion copolymerization of vinyl monomers such as acrylonitrile, (meth) acrylate, (meth) acrylic acid in the range of 40% by weight or less. Examples thereof include a polyvinylidene chloride latex type and a solvent type dissolved in an organic solvent.

Next, an organometallic compound-based gas barrier composition will be described. The organometallic compound-based composition for gas barrier includes an organometallic compound (I) represented by the following general formula and / or a hydrolyzed condensate thereof, R ¹ _m M (OR ² ) _n (I) (wherein M Represents a metal element, R ¹ may be the same or different and represents a hydrogen atom, a lower alkyl group, an aryl group, a vinyl group or a mercapto group directly bonded to a carbon chain, or a (meth) acryloyl group, and R ² is the same or They may be different and represent a hydrogen atom, a lower alkyl group or an acyl group, and R ¹ and R ² thereof may be substituted with any substituent, m is 0 or a positive integer, and n is 1 or more. And m + n is equal to the valence of the metal element M)
And a solvent as an essential constituent.

Since the organometallic compound can undergo hydrolysis polycondensation in the presence of water to form a dense coating film having a three-dimensional skeleton, it exhibits a gas barrier property equivalent to or higher than that of a polyvinylidene chloride gas barrier layer. However, since hydrolysis condensation polymerization can occur even with moisture in the air, the conventional open type roll coating method causes inconveniences such as change in solid content concentration and gelation. However, by adopting the continuous manufacturing method of the present invention, particularly by using a hermetically-type extrusion device, coating can be performed without being exposed to the atmosphere between the material tank and the discharge port, so that the above-mentioned inconvenience does not occur. It can continuously coat thin films.

Specific examples of the organometallic compound include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane and methyltributoxysilane. , Ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiisopropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane,
Diethyldiethoxysilane, diethyldiisopropoxysilane, diethyldibutoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltri Alkoxysilanes such as ethoxysilane, γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropyltriethoxysilane; acyloxysilanes such as tetraacetoxysilane and methyltriacetoxysilane; silanols such as trimethylsilanol; titanium tetra Titanium alkoxides such as ethoxide, titanium tetraisopropoxide, titanium tetrabutoxide; zirconium tetraethoxide, zirconium tet Isopropoxide, zirconium alkoxides such as zirconium tetrabutoxide;
One or more of aluminum alkoxides such as aluminum triethoxide, aluminum triisopropoxide, and aluminum tributoxide can be used.

Also included in the organometallic compound (I),
An organic silane compound having an amino group as an arbitrary substituent is preferably used because it has excellent film forming properties and forms a coating film having excellent gas barrier properties. Examples of the organic silane compound having an amino group include N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane and N-β- (Aminoethyl) -γ-aminopropyltriisopropoxysilane, N-β- (aminoethyl) -γ-aminopropyltributoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N- β- (aminoethyl) -γ
-Aminopropylmethyldiethoxysilane, N-β-
(Aminoethyl) -γ-aminopropylmethyldiisopropoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldibutoxysilane, N-β- (aminoethyl) -γ-aminopropylethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropylethyldiethoxysilane, N-β- (aminoethyl) -γ
-Aminopropylethyldiisopropoxysilane, N-
β- (aminoethyl) -γ-aminopropylethyldibutoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltributoxysilane, γ -Aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldiisopropoxysilane, γ-aminopropylmethyldibutoxysilane, γ
-Aminopropylethyldimethoxysilane, γ-aminopropylethyldiethoxysilane, γ-aminopropylethyldiisopropoxysilane, γ-aminopropylethyldibutoxysilane, γ-aminopropyltriacetoxysilane, γ- (2-ureidoethyl) ) Aminopropyltrimethoxysilane, γ- (2-ureidoethyl) aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, etc. And one or more of these can be used.

The organometallic compound (I) may be previously hydrolyzed and condensed in order to prevent evaporation during the drying after coating. When the amino group-containing organosilane compound is used as a part of the organometallic compound (I), it is preferable that the amino group-containing silane compound is previously hydrolyzed and condensed and then mixed with another organometallic compound. This is because the stability of the coating composition is improved. In addition, co-hydrolysis condensation may be carried out between the organometallic compound (I) and a compound having a hydrolyzable group among the compounds (III) described later.
These (co) hydrolysis condensation reactions can be carried out using a known catalyst, and it is advantageous to react in a solvent described later.

The organometallic compound-based coating composition may contain an organic compound (II) having a primary and / or secondary amino group in the molecule. Organic compound
(II) can reduce the amount of expensive organometallic compounds (especially amino group-containing silane compounds) used without deteriorating the gas barrier property, and can also form a film, flexibility of the coating, or other coating. It has the function of improving the physical properties of the film. Specifically, allylamine, diallylamine, isopropylamine, diisopropylamine, iminobispropylamine, ethylamine, diethylamine, 2-ethylhexylamine, 3-ethoxypropylamine, diisobutylamine, 3-diethylaminopropylamine, di-
2-ethylhexylamine, dibutylaminopropylamine, propylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, ethylenediamine, 1,4-diaminobutane, 1,2-diaminopropane, 1,3- Diaminopropane, hexamethylenediamine, ethanolamine,
Low-molecular-weight organic compounds such as diethanolamine; polyethyleneimines such as Epomin series manufactured by Nippon Shokubai Co., Ltd. (Epomin SP-003, Epomin SP-006, Epomin SP-012, Epomin SP-018, Epomin SP-
103, Epomin SP-110, Epomin SP-20
0, Epomin SP-300, Epomin SP-1000,
Epomin SP-1020 and the like); polyallylamines (for example, PAA-L and PAA-H manufactured by Nitto Boseki Co., Ltd.), amino group-containing (meth) such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate
Homopolymers of acrylates; or copolymers of these amino group-containing (meth) acrylates with other (meth) acrylates or (meth) acrylic acid, and high molecular weight organic compounds such as polyoxyethylene alkylamines.

Although ethanolamine and high molecular weight organic compounds are particularly excellent in gas barrier properties, it is advantageous to use high molecular weight organic compounds in order to improve film forming properties. Among the high molecular weight organic compounds, it is particularly preferable to use polyethyleneimines, which have good gas barrier properties and other properties of the resulting coating film. When a high molecular weight organic compound is used as the organic compound (II), the preferred molecular weight is 250 to
200,000. More preferably, it is in the range of 250 to 100,000. When the molecular weight is less than 250, the formed coating film may be inferior in flexibility, and conversely, when it is more than 200,000, transparency may be inferior.

The amount of the amino group-containing organic compound (II) used is
Although not particularly limited, it is preferably 2 times (weight) or less with respect to the organometallic compound (I). This is because if the amount of the organic compound (II) used exceeds twice, the gas barrier layer tends to have poor moisture resistance. More preferable amount of the organic compound (II) used is 1.5 with respect to the organometallic compound (I).
It is less than twice.

The organometallic compound-based coating composition may further contain an organic compound (III) having a functional group capable of reacting with the amino group of the organic compound (II). More preferably, the organic compound (III) has a hydrolyzable group such as an alkoxysilyl group. Compound (I
II) acts as a cross-linking agent, and it is possible to obtain a denser coating film having excellent gas barrier properties. The compound (III) is selected from compounds having an epoxy group, a carboxyl group, an isocyanate group, an oxazolinyl group, a hydroxyl group or the like as a functional group, and the functional group is preferably plural in the compound (III). The functional groups in this case may be the same or different. Of the above functional groups, the epoxy group has the highest reactivity with the amino group.

Further, the compound (III) may have a functional group capable of reacting with an amino group (epoxy group, carboxyl group, isocyanate group, oxazolinyl group, hydroxyl group) and a hydrolyzable alkoxysilyl group. . In this case, the compound (III) reacts with the amino group in the organic compound (II), and also causes a (co) hydrolysis polycondensation reaction alone or with the organometallic compound (I).
It is possible to form a dense and excellent gas barrier layer in which (I), (II) and (III) are combined. In order to further improve the water resistance of the coating film, the compound (III) preferably has an aromatic ring or its hydrogenated ring.

Specific examples of the compound (III) usable in the present invention include ethylene glycol diglycidyl ether,
Diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, nonaethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6- Aliphatic diglycidyl ethers such as hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and glycerol diglycidyl ether; glycerol triglycidyl ether;
Diglycerol triglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanurate,
Polyglycidyl ethers such as trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether; Aliphatic or aromatic diglycidyl esters such as adipic acid diglycidyl ester and o-phthalic acid diglycidyl ester; Bisphenol A diglycidyl ether, Resorcinol diglycidyl ether, hydroquinone diglycidyl ether, bisphenol S diglycidyl ether, bisphenol F diglycidyl ether, and compounds represented by the following formula

[0033]

Embedded image

Glycidyls having an aromatic ring such as or a hydrogenated ring thereof (including nuclear-substituted derivatives); or oligomers having a glycidyl group as a functional group (for example, in the case of bisphenol A diglycidyl ether oligomer, Can be represented);

[0035]

Embedded image

Isocyanates such as hexamethylene diisocyanate, tolylene diisocyanate, 1,4-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, tolidine diisocyanate, xylylene diisocyanate and dicyclohexylmethane diisocyanate;
Dicarboxylic acids such as tartaric acid and adipic acid; carboxyl group-containing polymers such as polyacrylic acid; oxazolinyl group-containing polymers and the like are mentioned as examples of the compound (III) having reactivity with an amino group. Alternatively, two or more kinds can be used. The compound (III) exemplified above
Among them, compounds having an aromatic ring or a hydrogenated ring thereof (including a nuclear-substituted derivative) have an effect of further improving the water resistance of the gas barrier layer.

Further, it has reactivity with both the amino group-containing organic compound (II) and -M (OR ² ) in the organometallic compound (I), that is, the functional group capable of reacting with the amino group and the hydrolyzability. Specific examples of the compound (III) having a group include β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriisopropoxysilane, β-
(3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ -Glycidoxypropyltriisopropoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, etc. (hereinafter sometimes abbreviated as epoxy group-containing silane coupling agent); γ -Isocyanopropyltrimethoxysilane, γ-isocyanopropyltriethoxysilane, γ-isocyanopropylmethyldimethoxysilane, γ-isocyanopropylmethyldiethoxysilane, etc. (hereinafter abbreviated as isocyanate group-containing silane coupling agent) Ah ) And the like, of these 1
Species or two or more can be used.

When the compound (III) is used, the functional group equivalent (Y) in the compound (III) is Y / X relative to the functional group equivalent (X) of the amino group in the organic compound (II). As 0.0
It is recommended to use it so as to be 1 to 1.0. Preferably, Y / X is in the range of 0.05 to 0.7, more preferably 0.05 to 0.3. If Y / X is less than 0.01, the flexibility of the coating film tends to be insufficient, and Y / X is 1.
If it exceeds 0, the gas barrier property and heat resistance may decrease.

The solvent that is essentially used in the organometallic compound coating composition is not particularly limited, but a solvent that can dissolve or disperse the components of the gas barrier composition is preferably selected. For example, methanol, ethanol, 2-propanol, butanol, alcohols such as ethylene glycol, acetone,
Ketones such as methyl ethyl ketone and methyl isobutyl ketone, aromatic hydrocarbons such as toluene, benzene and xylene, hydrocarbons such as hexane, heptane and octane,
Esters such as ethyl acetate and butyl acetate, and others, tetrahydrofuran, propyl ether, water and the like,
These 1 type, or 2 or more types can be mixed and used.

As described above, the organometallic compound-based coating composition used in the present invention contains the organometallic compound (I) and a solvent as essential components, and contains an amino group-containing organic compound (II) and an organic compound ( III) is included as needed. When the organic compound (III) has a hydrolyzable group together with a functional group capable of reacting with an amino group, the organic compound (III) may be previously (co) with the organometallic compound (I) or each alone.
It is recommended to allow the hydrolysis condensation reaction to proceed.
This is because if these compounds are made to have a high molecular weight by hydrolysis and condensation, the gas barrier layer can have good film-forming properties and the resulting coating film can have even more improved uniformity and smoothness.

The (co) hydrolytic condensation reaction proceeds even with water in the air, but it is preferable to carry out the reaction in the solvent as it can be directly used as a gas barrier composition in the coating step. The reaction may be performed by adding a known acid or base as a reaction catalyst. When the (co) hydrolysis reaction is carried out in advance, the molar ratio of water to the organometallic compound (I) (or compound (III) is included) is 0.01 to 3.0 (vs. the hydrolyzable compound). It is preferable. If it is less than 0.01 mol, cracks are likely to occur during the formation of the coating film, and it takes a long time to dry the film, making it meaningless to perform high-speed coating. The more preferable lower limit of the amount of water is 0.1 mol or more. Further, when the amount of water is too much, the hydrolysis reaction proceeds and the storage stability of the coating composition tends to be deteriorated. Therefore, the amount of water is 3.0 mol or less, preferably 2.0 mol or less, and more preferably 0 mol. It should be 8 mol or less.

The method for preparing the composition for gas barrier is not particularly limited, but when the compound (III) is used, the amino group of the organic compound (II) is reacted with the functional group in the compound (III) and then the organic compound (III) is reacted. Addition of the metal compound (I) or its hydrolytic condensate improves the stability of the composition. Compound
When (III) has a hydrolyzable group, it is advisable to carry out a (co) hydrolysis condensation reaction after the crosslinking reaction with the amino group and before or after the addition of the organometallic compound (I).

When the coating film obtained by the continuous production method of the present invention is coated with a vinylidene chloride resin or an organometallic compound-based gas barrier composition, the gas barrier property can be measured by the oxygen permeation of the coating film. 20 degrees at 20 ° C and 80% RH
It is preferably cc / m ² · 24 hrs · atm or less. A more preferable index of oxygen permeability is 20 ° C, 80%
The RH is 5 cc / m ² · 24 hrs · atm or less.

The surface smoothness of the coating film obtained by the continuous production method of the present invention is preferably within ± 25%. More preferable surface smoothness accuracy is within ± 10%,
More preferably within ± 3%. The surface smoothness is the degree of variation in the thickness (film thickness) of the coating film formed on the base material. This surface smoothness accuracy is within ± 25% means that when the film thickness is measured at multiple arbitrary points on the coating film and the average value is calculated, the measured values of the film thickness at each point are all average values. Is within the range of ± 25%, which is an index of the uniformity of the coating film thickness. In the case of ordinary use, if the surface smoothness is within ± 25%, the uniformity of the coating film is sufficient. When used as a base film for LCD display materials that require particularly high image quality, the uniformity of the thickness of the coating film is important, so the surface smoothness is within ± 10%,
It is recommended to use a coating film preferably within ± 3%.

In the above composition for gas barrier, various inorganic and organic additives such as a curing catalyst, a wettability improver, a plasticizer, a defoaming agent and a thickener are added to the extent that the effects of the method of the present invention are not impaired. You may add as needed. After coating these layers, layers having various functions can be coated by using the method of the present invention. Further, other layers may be laminated by other laminating means such as extrusion method, dry laminating, wet laminating, hot melt laminating, or the like, or vapor deposition may be performed after coating. In addition, when a water-soluble polymer such as polyvinyl alcohol or an ethylene-polyvinyl alcohol copolymer is added to an organometallic compound-based coating composition, the film-forming property is improved, and the uniformity and smoothness of the coating film are improved. Is improved, which is preferable.

The method for continuously producing a coating film of the present invention is not limited to vinylidene chloride resin, because a uniform thin film can be continuously produced at high speed without wasting the coating composition and continuous coating can be performed in a sealed system. However, coating compositions (organic metal compound-based compositions, oxidizable group-containing compositions, photocurable compositions, etc.) that may be adversely affected by atmospheric exposure or light, and other various coating compositions It can be preferably used as a thin and uniform continuous coating method.

[0047]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

Example 1 10 kg of polyvinylidene chloride latex (Saran latex L-502; manufactured by Asahi Kasei Co., Ltd.) having a viscosity of 10 cps at 20 ° C. was placed in the tank 5 of the hermetic extruder 1 shown in FIG. While adjusting a of 2 mm and b of 1 mm in the inside, nitrogen gas was introduced into the tank from the introduction pipe to extrude the polyvinylidene chloride latex, and 300 m / mi
A 12 μm polyethylene terephthalate film (hereinafter abbreviated as PET film) running at n was continuously applied. Subsequently, it was dried by passing through a drying oven at 100 ° C. to obtain a coating film. The physical properties of the obtained coating film are shown in Table 1.

Example 2 Example 1 except that the apparatus of FIG. 2 was used in place of the apparatus of FIG.
A coating film was produced in the same manner as in. The physical properties were evaluated and the results are shown in Table 1.

Comparative Example 1 The same polyvinylidene chloride latex as used in Example 1 was applied to a 12 μm PET film by the direct gravure coater method shown in FIG. The maximum speed at which uniform continuous coating was possible was 170 m / min. Table 1 shows the physical properties of the obtained film.

Example 3 7 kg of bisphenol A diglycidyl ether and 50 kg of methanol were added to 10 kg of γ-aminopropyltrimethoxysilane, and the mixture was stirred under a nitrogen atmosphere to give 7
The reaction was performed at 0 ° C. for 3 hours. After cooling to room temperature, water 0.2
kg was added, the mixture was stirred at room temperature for 2 hours, 10 kg of tetramethoxysilane was further added, and the mixture was stirred for 24 hours to obtain a coating composition. 2 of the obtained coating composition
The viscosity at 0 ° C. was 5 cps. Using this composition, coating and drying were carried out in the same manner as in Example 1 to produce a coating film. Table 2 shows the physical properties of the obtained film.
It was shown to.

Example 4 In a flask equipped with a stirrer, a thermometer and a condenser, Epomin SP-018 (polyethyleneimine manufactured by Nippon Shokubai) was used.
7.18 kg, γ-glycidoxypropyltrimethoxysilane 3.25 kg, and methanol 21.1 kg were charged, and the mixture was stirred under a nitrogen atmosphere at 65 ° C. for 3 hours, then cooled to room temperature, and water 0.1 kg and methanol 5 kg were added. The mixture was added dropwise over 15 minutes and stirred for 1 hour at room temperature. Then
To this reaction solution, a mixed solution of 52.0 kg of tetramethoxysilane and 15.4 kg of methanol was added and stirred at room temperature for 3 hours to obtain a coating composition. The viscosity of this composition at 20 ° C. was 7 cps. Using this composition, coating and drying were carried out in the same manner as in Example 2 to produce a coating film. Table 2 shows the physical properties of the obtained film.

Example 5 3 kg of tetraethoxysilane and 5 kg of methyltriethoxysilane, 50 kg of ethanol, 0.5 kg of water,
0.3 kg of 0.1N hydrochloric acid was added, and the mixture was stirred at room temperature for 48 hours to obtain a coating composition. The viscosity of the obtained coating composition at 20 ° C. was 5 cps or less (when the viscosity is 5 cps or less, the viscosity is too low to make accurate viscosity measurement possible). Using this composition, coating and drying were carried out in the same manner as in Example 1 to produce a coating film. The coating / drying rate was 300 m / min, the film thickness after drying was 2.0 μm, and the coating uniformity was ◯. No liquid dripping was observed during coating.

Comparative Examples 2-3 The coating compositions obtained in Examples 3-4 were coated in the same manner as in Comparative Example 1. After 1 to 2 hours, the coating composition had gelled, so that the coating could not be continued. Table 2 shows the physical properties of the film that can be produced before gelation.

The physical property evaluation methods are as follows. <Viscosity> It is a measured value at 20 ° C. measured by a B-type viscometer. <Thickness> This is the average value of the thickness of the coating film of the coating film after drying. <Liquid sagging> When the coating composition drops (drips) from the discharge port of the device and not all of the extruded coating composition is transferred to the film, x is defined, and there is no liquid sagging and 100% transfer. When it was possible, it was marked as ○.

<Coating Uniformity> 5 of Coating Film
The thickness of the coating film is measured every 00 m, and when all the film thicknesses are within ± 3% of the average value, it is ⊚, when it is within ± 25%, it is ○, and when it is out of ± 25%, it is ×. And <Oxygen permeability> 20 ° C, 80% RH by Mocon method
It measured on condition of.

[0057]

[Table 1]

[0058]

[Table 2]

Example 6 To 4 kg of tetraethoxysilane, 0.1 N hydrochloric acid was added.
After adding 8 kg and 13 kg of water and stirring at room temperature for 1 hour,
An aqueous solution of polyvinyl alcohol was added, and the mixture was further stirred for 30 minutes. The polyvinyl alcohol aqueous solution was added so that the polyvinyl alcohol (solid content) was 1: 1 (weight ratio) with respect to the value obtained by converting tetraethoxysilane into SiO ₂ . The viscosity of the obtained coating composition at 20 ° C. was 10 cps. Using this composition, coating and drying were carried out in the same manner as in Example 1 to produce a coating film. The coating / drying rate was 200 m / min, the film thickness after drying was 1.0 μm, and the coating uniformity was ◯. No liquid dripping was observed during coating. Oxygen permeability is 20
1.5 cc / m ² · 24hrs · a at ℃ and 80% RH
tm.

Example 7 A 15% aqueous solution of 30 L of soanol having a viscosity at 20 ° C. of 90 cps (ethylene-vinyl alcohol copolymer manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was used for coating and drying in the same manner as in Example 1, A coating film was produced. The coating / drying rate was 120 m / min, the film thickness after drying was 1.5 μm, and the coating uniformity was ◯. No liquid dripping was observed during coating. Oxygen permeability is 20c, 80% RH, 10c
It was c / m ² · 24 hrs · atm.

Example 8 10.4 kg of resorcinol diglycidyl ether and 50.0 kg of methanol were added to 45.4 kg of γ-aminopropyltrimethoxysilane, and the mixture was reacted at 70 ° C. for 3 hours while stirring under a nitrogen atmosphere. After cooling to room temperature, 35.9 kg of methanol was added, and then water 3.
A mixed liquid of 6 kg and 47.2 kg of methanol was added dropwise over 30 minutes. After stirring at room temperature for 1 hour, a mixed solution of 29.9 kg of M-silicate 51 (tetramethoxysilane oligomer manufactured by Tama Chemical Co., Ltd.) and 20.0 kg of methanol was added dropwise over 30 minutes, and further 5.5 kg of water and 74 of methanol were added. A mixture of 0.6 kg was added and stirred for 24 hours to obtain a coating composition. The viscosity of the obtained coating composition at 20 ° C. was 10 cps. Using this composition, coating and drying in the same manner as in Example 1,
A coating film was produced. Coating and drying speed is 1
The film thickness after drying at 50 m / min was 1.5 μm, and the coating uniformity was ◯. No liquid dripping was observed during coating. Oxygen permeability is 1.0cc at 20 ° C and 80% RH
/ M ² · 24 hrs · atm.

Example 9 A coating film was prepared by coating and drying in the same manner as in Example 1 except that the same polyvinylidene chloride latex as used in Example 1 was used and the coating speed was changed to 450 m / min. Manufactured. The film thickness after drying was 2.3 μm, and the coating uniformity was ◯. No liquid dripping was observed during coating. Oxygen permeability is 15c at 20 ° C and 80% RH
It was c / m ² · 24 hrs · atm.

Example 10 The procedure of Example 1 was repeated except that the coating composition obtained in Example 8 was used, the coating speed was 50 m / min, and the apparatus shown in FIG. 2 was used. This was applied to both sides of a polycarbonate film and dried to produce a coating film. The film thickness after drying is 1.
The coating uniformity was 0 μm and the coating uniformity was ⊚. No liquid dripping was observed during coating. Oxygen permeability is 20 ° C, 80%
The RH was 0.2 cc / m ² · 24 hrs · atm.

[0064]

EFFECTS OF THE INVENTION By adopting the continuous method for producing a coating film of the present invention, it is possible to continuously apply a low-viscosity coating composition at a high speed of 300 m / min or more. Further, since the coating composition is not adversely affected by the atmosphere and light before coating, it is suitable for continuous coating of a hydrolyzable composition, an easily oxidizable group-containing composition, a photocurable composition, and the like. There is. Further, as in the conventional roll coating method, the coating composition can be 100% transferred to the base film without being wasted, so that a relatively expensive gas barrier composition can be continuously applied uniformly. Is also useful as

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a method for producing a coating film of the present invention.

FIG. 2 is an explanatory view of another method for producing the coating film of the present invention.

FIG. 3 is an explanatory diagram of a coating method using a conventional direct gravure coater.

[Explanation of symbols]

 1 Sealing Extruder 2 Discharge Port 3 Film Substrate 4 Coating Film 5 Tank 6 Gas Introducing Tube 7 Die 8 Coating Composition

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location // C08L 27/08 LFU C08L 27/08 LFU C09D 127/08 PFE C09D 127/08 PFE

Claims (9)

[Claims] 1. The viscosity at 20 ° C. is 0.1 to 100 cps.
The coating composition as described above is extruded from the wide slit-shaped discharge port toward the surface of the film substrate running, and 0.1
A continuous production method of a coating film, which comprises forming a thin film of -20 μm. 2. The method for continuously producing a coating film according to claim 1, wherein the coating composition forms a gas barrier coating film. 3. The method for continuously producing a coating film according to claim 1, wherein the coating composition contains a vinylidene chloride resin. 4. The coating composition comprises an organometallic compound (I) represented by the following general formula and / or a hydrolyzed condensate thereof, R ¹ _m M (OR ² ) _n (I) (wherein M Represents a metal element, R ¹ may be the same or different and represents a hydrogen atom, a lower alkyl group, an aryl group, a vinyl group or a mercapto group directly bonded to a carbon chain, or a (meth) acryloyl group, and R ² is the same or They may be different and represent a hydrogen atom, a lower alkyl group or an acyl group, and R ¹ and R ² thereof may be substituted with any substituent, m is 0 or a positive integer, and n is 1 or more. And m + n is equal to the valence of the metal element M)
The method for continuously producing a coating film according to claim 1, which further comprises a solvent and a solvent. 5. The method for continuously producing a coating film according to claim 4, wherein all or part of the organometallic compound (I) is an organosilane compound having R ¹ substituted with an amino group. 6. The coating according to claim 4, wherein the coating composition has an organic metal compound (I) and an organic compound (II) having a primary and / or secondary amino group in the molecule. Continuous film manufacturing method. 7. The coating composition further comprises an organic compound (I) having in the molecule thereof a functional group capable of reacting with an amino group.
II) is contained, The continuous manufacturing method of the coating film of Claim 5 or 6 characterized by the above-mentioned. 8. The method according to any one of claims 1 to 7, wherein the oxygen permeability is 20.degree.
A coating film having a RH of 0% and 20 cc / m ² · 24 hrs · atm or less. 9. The surface smoothness of the coating film obtained by the continuous manufacturing method according to claim 1, and having a surface smoothness of ± 2.
A coating film characterized by being within 5%.