JP2006095372A - Coating method and coating solution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating method for forming a coating film which imparts cissing resistance and has a flexible finish effect, a water repelling effect, an antistatic effect and a sterilization and disinfection effect, and a coating solution used therein. <P>SOLUTION: The coating solution 17 is obtained in a coating solution preparing process 16. The ratio (A/C) of the mol conentration A(mol/m<SP>3</SP>) of the anionic surfactant in the coating solution and mol concentration C(mol/m<SP>3</SP>) of the cationic surfactant therein is set to 3.6 or above and the mol concentration A of the anionic surfactant is set to 1.5 mol/m<SP>3</SP>or above. The dynamic surface tension of the coating solution 17 at the time of coating of a web 21 with the coating solution 17 becomes 40 mN/m or below and a film product 25 having cissing resistance and developing the flexible finish effect and the like can be obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coating method and a coating solution when various liquid compositions are coated on a long belt-like support (hereinafter referred to as a web).

  By applying various liquid compositions (hereinafter referred to as coating solutions) to the web, photographic film, photographic printing paper, printing photosensitive material, medical photosensitive material, photothermographic material, microfilm, magnetic recording tape Adhesive tape, pressure-sensitive recording paper, heat-sensitive recording paper, offset plate, liquid crystal screen material, flat panel material, ink jet printer image receiving material, sealing material and the like are manufactured.

  When the coating solution is applied on the web, the uniformity of the coating surface quality accounts for a very large proportion, and it is one of the most important qualities in the application of photographic materials and thin film. In forming a uniform coating film, the fact that the film repels in a crater form (hereinafter referred to as repelling) is a fatal problem. First, priority should be given to selecting coating conditions that do not generate repelling. I must. This repellency is triggered by impurities and micro mixing failure, and the higher the surface tension of the coating solution, the stronger the force to minimize the surface area of the coating solution, and the easier it will be. For this reason, in order to suppress repelling, generally, a method of applying in an environment in which the surface tension of the coating solution is lowered or contaminants are excluded is performed (for example, see Non-Patent Document 1). In order to reduce the surface tension of the coating solution, it is useful to add a surfactant to the surface of the coating solution that is in contact with the gas. Especially, it has excellent solubility and dynamics immediately after a new surface is formed. Aerosol OT (trade name), Triton X (trade name), fluorine-based anionic surfactants and the like having a high ability to reduce the surface tension are widely used.

In addition, a method in which an anionic, cationic, betaine, or nonionic surfactant is contained in a coating solution is known. In this case, it is known to contain the same amount of an anionic surfactant and a cationic surfactant (see, for example, Patent Document 1). Also known is a method in which the content of the cationic surfactant and the anionic surfactant is 1:10 to 10: 1, preferably 3: 7 to 7: 3, in terms of molar ratio (for example, patents). Reference 2). The total usage 0.0001g / m ² ~1.0g / m ² of anionic surfactants, preferably ^{0.0005g / m 2 ~0.3g / m 2} , more preferably 0.001 g / m ^{2 to} 0.15 g / m ² , and in this case also, it is known that a cationic surfactant (particularly a fluorosurfactant) can be mixed (for example, Patent Documents). 3).

Furthermore, Patent Document 4 and Patent Document 5 also describe a method in which a cationic surfactant and an anionic surfactant are mixed in a coating solution. Furthermore, when applying to a polyester film, in order to process aluminum oxide, 0.01 times-0.05 times of cationic surfactant and 0.01 times-0.05 times in solid content ratio. A method of containing an amount of an anionic surfactant is known (for example, see Patent Document 6).
Chemical Engineering Vol.67 (2003) p48 JP 10-319535 A Japanese Patent Laid-Open No. 5-265126 JP-A-8-069082 Japanese Patent Application Laid-Open No. 5-197068 JP-A-6-114329 JP-A-6-145390

  However, even a coating solution imparted repellency resistance with an anionic surfactant can be treated with a cationic surfactant as shown in “New Edition Surfactant Handbook” (Tokiyuki Yoshida et al., Engineering Book, published in 1987) p24. Even if an attempt is made to coexist with a cationic surfactant in order to utilize the soft finishing effect, water repellent effect, antistatic effect, bactericidal disinfection effect, etc. of the agent, as shown in p. Since an insoluble precipitate is formed with the agent, in general, it cannot be shared or may be shared depending on experimental conditions, but it is a very difficult problem to find the experimental conditions. Therefore, it is a very difficult problem to form a coating film by suppressing the repellency by using the flexible finishing effect, water repellency effect, antistatic effect, and sterilizing / disinfecting effect of the cationic surfactant.

  The method described in Patent Document 1 is a method using either an anionic surfactant or a cationic surfactant in the coating solution. Therefore, it is necessary to select either an imparting repelling property to the film with an anionic surfactant or a soft finishing effect to the film with a cationic surfactant. Moreover, although the method described in Patent Document 2 defines the addition ratio of the cationic surfactant and the anionic surfactant, its critical significance is not clear, and the effect is particularly referred to. Not. Furthermore, although the method described in Patent Document 3 is a method in which a preferable amount of an anionic surfactant is described, the addition ratio of the cationic surfactant is not particularly referred to, so that it is cationic. The effect produced when the surfactant is applied cannot be obtained.

  Further, the methods described in Patent Document 4 and Patent Document 5 are also effective when an anionic surfactant and a cationic surfactant are added to a coating solution, but the mixing ratio thereof is particularly referred to. However, there is a problem that one surfactant may reduce the effect of the other surfactant. Further, in the method described in Patent Document 6, the amount of the surfactant to be added is used for the treatment of aluminum oxide, and does not reduce the repellency of the coating film according to the present invention. This method is for stably dispersing aluminum oxide, and does not improve the wettability and repellency resistance of the coating film.

  In this way, an anionic surfactant is added to the coating solution to impart repellency resistance, and in order to impart a soft finishing effect, water repellency effect, antistatic effect, and sterilizing and disinfecting effect to the coating film, a cation is added to the coating solution. It is extremely difficult to add experimental surfactants to select experimental conditions.

  The present invention relates to a coating method for imparting repellency resistance and forming a coating film having a soft finishing effect, a water repellent effect, an antistatic effect, and a sterilizing and disinfecting effect, and a coating liquid used in the coating method.

The coating method of the present invention is the coating method in which the coating solution applied to the long web is a composition containing both an anionic surfactant and a cationic surfactant. The ratio R (= A / C) of the molar concentration A (mol / m ³ ) of all anionic surfactants to the molar concentration C (mol / m ³ ) of all cationic surfactants is 3. 6 ≦ R. Further, 5.0 ≦ R is more preferable.

The coating method of the present invention is a coating method in which the coating liquid to be applied to the long web is a composition containing both an anionic surfactant and a cationic surfactant. The ratio R (= A / C) of the molar concentration A (mol / m ³ ) of all anionic surfactants to the molar concentration C (mol / m ³ ) of all the cationic surfactants is R <1 It is.

The molar concentration A of the anionic surfactant is preferably 1.5 mol / m ³ or more. The dynamic surface tension of the coating solution at 100 msec is preferably 40 mN / m or less. It is preferable that the film thickness immediately after coating the coating solution on the web is 5 μm or more and 40 μm or less. It is preferable that the coating is a multilayer coating using a plurality of coating solutions, and the coating solution forms the uppermost layer. The multilayer coating is preferably a multilayer simultaneous coating. The coating is preferably a single layer coating. It is preferable that the coating liquid is applied to the web using a manifold die or a bar coater.

In the coating liquid of the present invention, the coating liquid applied to the long web is a composition containing both an anionic surfactant and a cationic surfactant. The ratio R (= A / C) of the molar concentration A (mol / m ³ ) of all anionic surfactants to the molar concentration C (mol / m ³ ) of all the cationic surfactants is 3.6. ≦ R. In addition, the coating liquid of the present invention contains a coating liquid that is applied to the long belt-like web, in which the coating liquid contains both an anionic surfactant and a cationic surfactant. The ratio R (= A / C) of the molar concentration A (mol / m ³ ) of all anionic surfactants to the molar concentration C (mol / m ³ ) of all cationic surfactants is R <1. The molar concentration A (mol / m ³ ) of the anionic surfactant is preferably 1.5 mol / m ³ or more. The dynamic surface tension of the coating solution at 100 msec is preferably 40 mN / m or less.

According to the coating method of the present invention, in the coating method in which the coating liquid applied to the long web is a composition containing both an anionic surfactant and a cationic surfactant, the coating liquid is The ratio R (= A / C) of the molar concentration A (mol / m ³ ) of all the anionic surfactants contained and the molar concentration C (mol / m ³ ) of all the cationic surfactants, Since 3.6 ≦ R or R <1, it is a coating method capable of forming a coating film having both repellency resistance and a soft finishing effect, a water repellent effect, an antistatic effect, and a sterilizing and disinfecting effect.

According to the coating liquid of the present invention, the coating liquid applied to the long belt-like web is a composition containing both an anionic surfactant and a cationic surfactant, and the coating liquid contains The ratio R (= A / C) of the molar concentration A (mol / m ³ ) of all anionic surfactants to the molar concentration C (mol / m ³ ) of all cationic surfactants is 3 Since .ltoreq.6.ltoreq.R or R <1, the coating solution is capable of forming a coating film that has repellency resistance and has a soft finishing effect, a water repellent effect, an antistatic effect, and a sterilizing and disinfecting effect.

  The coating method of the present invention will be described with reference to the process diagram of FIG. The coating liquid 17 is prepared by the coating liquid preparation process 16 using the solvent 11, the binder 12, the anionic surfactant 13, the cationic surfactant 14, and various additives 15 as desired. Next, the coating process 20 is performed. In the coating step 20, the coating liquid 17 is applied to the web 21 that is continuously conveyed using the coating device 22. The web to which the coating liquid 17 is applied is referred to as a coated web 23. The coated web 23 is dried to a desired level by a drying process 24 to become a product 25. The product 25 is wound up in a winding process 26. In addition, the product 25 may be cut and sequentially stored in a plate shape without performing the winding process 26.

[solvent]
The solvent may be a mixture instead of a pure substance. Moreover, you may add by solid content like a powder or a wax. In order to dissolve the chemicals in the surfactant solution, they may be heated to 30 ° C. to 100 ° C. or may be dispersed by applying ultrasonic waves. Further, they may be mixed after coarsely dispersing in advance with a disperser such as a dissolver.

[Binder]
In the coating solution, as a medium for forming a film after drying, polymers such as gelatin, cellulose, polyvinyl alcohol, and other natural polymers such as binder, synthetic polymers, silver halide, dispersion particles, latex, A solid content such as an emulsion is contained.

[Surfactant]
In the present invention, the term “surfactant” refers to a straight chain of carbon, a benzene ring, naphthalene, 2 or 3 as described in “New Edition Surfactant Handbook” (Tokiyuki Yoshida et al., Engineering Book 1987). A material having both a hydrophobic group mainly composed of a carbon chain branched into these groups and a combination thereof and a hydrophilic group such as carboxylic acid, sulfonic acid, and polyethylene oxide in the molecule. The molecular weight of the surfactant used in the present invention is not particularly limited as long as it has this characteristic, but a molecular weight of 1000 or less is preferable. An anionic surfactant means a surfactant that dissociates from a counter ion in a liquid and becomes an anion in the main chain. The cationic surfactant means a surfactant that dissociates from a counter ion in water and becomes a cation in the main chain. Here, the main chain indicates the side having a higher molecular weight after dissociation. A surfactant preferably used in the present invention is shown in Chemical Formula 1.

In order to calculate the addition ratio R of the present invention, the molar concentration of the surfactant is defined. When an anionic surfactant m _a (g) having _a molecular weight Mw (g / mol) was dissolved in a coating solution of V (m ³ ), the molar concentration A (mol / m ³ ) of the anionic surfactant was A = (m _a / Mw) / V. In the case of a cationic surfactant, the molar concentration C (mol / m ³ ) is represented by C = (m _c / Mw) / V.

  Anionic surfactants and cationic surfactants dissociate from counterions in the liquid. The counter ion is typified by sodium, potassium, calcium, magnesium, lithium, aluminum, chlorine, bromine, iodine, organic salt, and the like, but is not limited thereto. The molecular weight of this counter ion is also added to the molecular weight when calculating the molar concentration. In some cases, the surfactant has a molecular weight distribution. In this case, the molar concentration is calculated using the average molecular weight as the molecular weight. The molar concentration of the surfactant of the present invention is calculated based on the main chain regardless of the valence of the hydrophilic group or counter ion. As long as the definition of this surfactant is satisfied, elements such as fluorine, phosphorus, sulfur and chlorine may be contained in the molecule.

When a plurality of anionic surfactants or cationic surfactants of the present invention are used, the total molar concentration of the anionic surfactant is A (mol / m ³ ), and the total molar amount of the cationic surfactant is The concentration is calculated with C (mol / m ³ ) as C.

  For bipolar surfactants that dissociate from counterions in water and have both a cation and anion in the main chain, it is a question of whether or not aggregated nuclei with coexisting surfactants are generated. In the present invention, when the coexisting surfactant is an anionic surfactant, the amphoteric surfactant is cationic. When the coexisting surfactant is a cationic surfactant, the amphoteric surfactant is anionic. It is considered.

  In the present invention, the dynamic surface tension is a surface immediately after a liquid forms a new surface as shown in “Liquid Film Coating”, Ed by Kistler & Schweizer (Chapman & Hall) Chapter 4, p99 to p136. It is tension. The surface tension of the liquid containing the surfactant indicates a value measured on a new surface before the surface orientation of the surfactant reaches equilibrium. The measurement method includes the maximum bubble pressure method, vibration jet method, membrane destruction method, hanging drop method, Falling Meniscus method, drop weight method, etc. But you can.

[Additive]
As described above, various additives such as a pH adjuster, a preservative, and a thickener can be contained in addition to the surfactant for suppressing repelling.

[Coating solution]
The solvent main component of the coating liquid in the present invention is preferably water, but may contain preservatives, surfactants, thickeners, emulsions, antifreeze liquids, and liquids other than water may be used. It does not matter.

  In the present invention, when preparing the coating solution, either the anionic surfactant or the cationic surfactant may be added first, or both may be added after mixing in advance. Both anionic surfactants and cationic surfactants may be chemicals diluted in advance with a solvent such as water or methanol. It is preferable to add a preservative to the chemical. Physical properties such as pH, electric power and viscosity are not particularly limited.

[web]
For the web, paper, plastic film, resin-coated paper, synthetic paper or the like can be used. As the material of the plastic film, for example, a polyolefin such as polyethylene or polypropylene, or a vinyl polymer such as vinyl acetate, polyvinyl chloride, or polystyrene can be used. Polyamides such as nylon-66 and nylon-6, and polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate can also be used. Further, polycarbonate and the like can be used, and cellulose acetate such as cellulose triacetate (hereinafter also referred to as TAC) and cellulose diacetate can be used. In these webs, an undercoating layer such as gelatin is preferably formed on the surface of the web in order to improve the coating property. The resin used for the resin-coated paper is typically polyolefin such as polyethylene, but is not necessarily limited thereto.

[Coating process]
In the coating line shown in FIG. 2, the web 21 is sent out from the sending machine 31 and sent to the heating chamber 32. The web 21 is heated while being conveyed to heating rollers 33 provided in a large number in the heating chamber 32. Thereafter, it is sent to the cooling chamber 34. In the cooling chamber 34, the web 21 is cooled to a desired temperature by a plurality of cooling rollers 35. For example, when TAC is used for the web 21, the web 21 is heated at the outlet of the heating chamber 32 so that the temperature of the web 21 becomes 50 ° C. to 120 ° C., and the temperature of the web 21 at the outlet of the cooling chamber 34 becomes 10 ° C. to 40 ° C. It is preferable to cool so that. Thereby, the plastic deformation of the web 21 is recovered, and the coating liquid 17 is easily applied to the surface. In the present invention, it is not always necessary to heat and cool the web 21 in advance before applying the coating liquid 17.

  The web 21 is sent out from the cooling chamber 34 and then sent to the charging unit 40 while being conveyed by the roller 37. The charging unit 40 includes a charger 41 that charges the surface of the web 21 and a surface potential meter 42 that measures the surface potential. In order to make it easy to apply the coating liquid 17 on the surface of the web 21, it is preferable to set the surface potential to 150 V to 1500 V by the charger 41. In the present invention, it is not always necessary to charge the surface of the web 21 before applying the coating liquid 17 to the web 21.

  The web 21 conveyed from the charging unit 40 is coated with the coating liquid 17 by the coating device 22. The coating device 22 includes a coating roller 50, a back decompression chamber 51, a backup roller 52 that travels while winding the web 21, and a temperature controller 53 that is attached to the coating die 50 to adjust the temperature of the coating solution 17. I have. A coating film is formed from the coating solution coated on the web 21 by the coating device 22 to form a coated web 23. The product 25 is obtained by being conveyed by a roller 54 to a drying device (not shown). As the backup roller 52, it is preferable to use a metal roller or a roller that can be coated with a thin ceramic coating to prevent charge leakage as disclosed in JP-A-2-251266, but any known roller can be used. In the present invention, the back decompression chamber 51 and the temperature controller 53 are not necessarily attached to the coating device 22.

  The coating device 22 will be described in more detail with reference to FIG. The coating die 50 is provided with three die blocks 60, 61, and 62 as a single unit. A slide surface 63 is formed on the upper surface of the coating die 50. The slide surface 63 is inclined so as to become lower toward the backup roller 52. In the die blocks 60 to 62, three layers of coating liquids 17a, 17b, and 17c applied to the web 21 are supplied to the manifolds 67, 68, and 69 by liquid feeding pumps that can vary the amount of liquid feeding from respective coating liquid tanks (not shown). Supplied. The coating liquids 17a to 17c may be supplied from the center in the width direction of the manifolds 67 to 69, or may be supplied from one end of the manifolds 67 to 69. In the present invention, the manifolds 67 to 69 may have any known shape.

  The coating liquids 17a to 17c supplied to the manifolds 67 to 69 are pushed out to the slide surface 63 through the slots 70, 71, 72. The coating liquids 17a to 17c pushed out onto the slide surface 63 form a multilayer liquid film 73 on the slide surface 63, and then a coating bead 75 is formed from the lip 74, which is the tip of the coating die 50, and applied onto the web 21. Thus, the coated web 23 on which the coating film 76 is formed is obtained. In the present invention, the coating speed is not particularly limited, but is preferably 0.1 m / s to 10 m / s, more preferably 1 m / s to 4 m / s.

  The back surface decompression chamber 51 is attached in order to reduce the pressure applied to the web 21 of the formed application bead 75 (hereinafter referred to as the back surface). Generation | occurrence | production of an air entrainment phenomenon can be prevented by depressurizing the back surface of the formed application bead 75. In the present invention, the degree of vacuum is not particularly limited, but the difference (P0−Pb) between the atmospheric pressure P0 on the surface of the formed coating bead 75 and the pressure Pb on the back surface is preferably 300 Pa to 1000 Pa. More preferably, it is 400 Pa-700 Pa.

  As the coating die apparatus of the present invention, any one of a slide bead method, a slide curtain method, an extrusion bead method, an extrusion curtain method, a dip method, a bar coater method, a comma coater method, a combination thereof, a single layer coating, or a multilayer Application, simultaneous application, or successive multilayers may be used.

  Hereinafter, the present invention will be described more specifically with reference to Examples 1 to 5. The types of materials, their proportions, operations and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

Using a coating apparatus 22 shown in FIG. 2, a lower layer coating solution 17a (gelatin concentration: 4%, viscosity: 80 mPa · s, wet film thickness: 20 μm) is applied to a triacetylcellulose support (web) 21 subjected to gelatin undercoating. The intermediate layer coating solution 17b (gelatin concentration 8%, viscosity 150 mPa · s, wet film thickness 100 μm) and top layer coating solution 17c (gelatin concentration 6%, viscosity 40 mPa · s wet film thickness 10 μm) were used. The viscosity of each layer was adjusted by adding polyvinyl sulfonic acid. The pH of the coating liquids 17a, 17b, and 17c for each layer was adjusted to 5.5 to 7.0. The coating speed is 2 m / sec, the top layer coating solution 17c is 3.50 mol / m ³ of anionic surfactant A3 (see Chemical Formula 1), and 0.41 mol / cation of the cationic surfactant C1 (See Chemical Formula 1). m ³ was added. In this case, the addition ratio R (= anionic surfactant A / cationic surfactant C) was 10.1. The temperature of the web 21 was 30 ° C. to 45 ° C., the temperature of each coating liquid 17a to 17c was 40 ° C., and the degree of vacuum on the back surface was atmospheric pressure −500 Pa. The number of repellency of the coating film 76 was measured visually. The repelling effect is extremely effective for suppressing repelling when the repelling number is 5 / m ² or less (◎), and is effective for suppressing repelling when the repelling number is 300 / m ² or less (O), 300 / m ² Exceeding, it was carried out in three stages with no repelling effect (×). Furthermore, each experiment of Experiment 2 thru | or 4 was conducted changing the addition amount and addition ratio R of anionic surfactant A3. The experimental conditions and experimental results are summarized in Table 1.

In Experiment 5 of Example 2, anionic surfactant A2 (see Chemical Formula 1) was used in place of anionic surfactant A3. In Experiment 5, 2.50 mol / m ^{3 of} an anionic surfactant A2 and 0.41 mol / m ³ of a cationic surfactant C1 were added to the uppermost layer coating solution. The other experimental conditions were the same as those in Experiment 1 of Example 1. Further, Experiments 6 to 10 were performed by changing the addition amount and the addition ratio R of the anionic surfactant A2. The experimental conditions and experimental results are summarized in Table 2.

In Experiment 11 of Example 3, the anionic surfactants A2 and A3 of Chemical Formula 1 were used in combination, and the cationic surfactant C2 of Chemical Formula 1 (see Chemical Formula 1) was used. Adding a 2.5 mol / m ³ of anionic surfactants A2 and 2.5 mol / m ³ of anionic surfactant A3 and 0.5 mol / m ³ of cationic surfactants C2 in the top layer coating solution did. At this time, the addition ratio R {= (A2 + A3) / C2} was 9.96. The other experimental conditions were the same as those in Experiment 1 of Example 1.

  In Experiment 11, static surface tension and dynamic surface tension at 100 msec were measured. The static surface tension was measured with a Whilhelmy type surface tension meter (Surface Tensiomater CBVP-A3 type manufactured by Kyowa Interface Science Co., Ltd.), and the dynamic surface tension was measured using a maximum bubble pressure type surface tension meter (Kyowa Interface Science Co., Ltd.). BP-D3 type surface tension meter). Further, Experiment 12 was performed by changing the addition amount and addition ratio R of the anionic surfactants A2 and A3 and the cationic surfactant C2. The experimental conditions are summarized in Table 3, and the experimental results are summarized in Table 4.

From each experiment of Example 1 thru | or Example 3, it turned out that the repellency suppression effect improves, so that the addition ratio R is large. It was found that the effect was more pronounced (◯) when R was 3.6 or more, and very marked (◎) when R was 5.0 or more. Furthermore, when the concentration of the anionic surfactant added (the sum of a plurality of anionic surfactants as in Experiment 11) increases, the repellency suppressing effect is improved, and when it is 1.5 mol / m ³ or more, the effect is remarkably exhibited. I found out that

  From Experiment 11 and Experiment 12 of Example 3, the static surface tension does not correlate with the addition ratio or repellency suppression, but when the addition ratio R is large, the dynamic surface tension at 100 msec decreases and the cissing suppression effect is improved (◎). I found out that

In Experiment 13 of Example 4, 2.00 mol / m ^{3 of} an anionic surfactant A2 and 0.41 mol / m ³ of a cationic surfactant C1 were added to the top layer coating solution. At this time, the addition ratio R (= A / C) was 4.88. And it experimented on the same conditions as the experiment 1 of Example 1 except having experimented so that the top layer film thickness might be set to 40 micrometers (at the time of application | coating). Further, Experiments 14 to 18 were performed by changing the film thickness of the uppermost layer. The experimental conditions and results are summarized in Table 5.

  The repellency suppressing effect was manifested when the uppermost layer thickness was 5 μm or more (◯), and the effect appeared more markedly when the thickness was 20 μm or more (以上). As in Experiment 18, when the uppermost layer thickness was 80 μm, the coating film was unevenly dried, and the effect of suppressing repellency could not be confirmed.

  In Experiment 19 of Example 5, an anionic surfactant A1 (see Chemical Formula 1) and a cationic surfactant C1 (see Chemical Formula 1) were added to the uppermost layer coating solution. In this experiment, the addition amount of the surfactant was adjusted so that the cationic surfactant was excessive (that is, R <1). In this case, the addition ratio R was 0.16. The other experimental conditions were the same as those in Experiment 1 of Example 1. Further, Experiment 20 and Experiment 21 were performed by changing the addition amount and addition ratio R of the anionic surfactant A1. The experimental conditions and experimental results are summarized in Table 6.

  In Experiment 21 in which the addition ratio R was about 1, it was found that the repellency suppressing effect was difficult to be exhibited. That is, according to the present invention, when an anionic surfactant is added excessively (3.6 ≦ R, more preferably 5.0 ≦ R) and when a cationic surfactant is added excessively (R <1). ) Was found to be effective in suppressing repellency.

It is process drawing for enforcing the coating method of this invention. It is the schematic of the installation for enforcing the coating method of this invention. It is a principal part enlarged view of FIG.

Explanation of symbols

13 Anionic surfactant 14 Cationic surfactant 16 Coating liquid preparation step 17 Coating liquid 21 Web 22 Coating device 23 Coated web 76 Coating film

Claims (14)

In the coating method in which the coating liquid applied to the long belt-shaped web is a composition containing both an anionic surfactant and a cationic surfactant,
The ratio R (= A /) of the molar concentration A (mol / m ³ ) of all anionic surfactants contained in the coating liquid and the molar concentration C (mol / m ³ ) of all cationic surfactants. C)
3.6 ≦ R, a coating method characterized in that In the coating method in which the coating liquid to be applied to the long web is a composition containing both an anionic surfactant and a cationic surfactant,
The ratio R (= A /) of the molar concentration A (mol / m ³ ) of all anionic surfactants contained in the coating liquid and the molar concentration C (mol / m ³ ) of all cationic surfactants. C)
The coating method, wherein 5.0 ≦ R. In the coating method in which the coating liquid to be applied to the long web is a composition containing both an anionic surfactant and a cationic surfactant,
The ratio R (= A /) of the molar concentration A (mol / m ³ ) of all anionic surfactants contained in the coating liquid and the molar concentration C (mol / m ³ ) of all cationic surfactants. C)
A coating method, wherein R <1. The coating method according to claim 1, wherein the molar concentration A of the anionic surfactant is 1.5 mol / m ³ or more.   5. The coating method according to claim 1, wherein a dynamic surface tension of the coating solution at 100 msec is 40 mN / m or less.   The coating method according to any one of claims 1 to 5, wherein a film thickness immediately after coating the coating liquid on the web is set to 5 µm or more and 40 µm or less.   7. The coating method according to claim 1, wherein the coating liquid is a multilayer coating using a plurality of coating liquids, and the coating liquid forms an uppermost layer.   The coating method according to claim 7, wherein the multilayer coating is a multilayer simultaneous coating.   The coating method according to claim 1, wherein the coating is a single layer coating.   The coating method according to claim 1, wherein the coating liquid is applied to the web using a manifold die or a bar coater. In the coating liquid applied to the long belt-like web is a composition containing both an anionic surfactant and a cationic surfactant,
The molar concentration A (mol / m ³ ) of all anionic surfactants contained in the coating solution,
The ratio R (= A / C) to the molar concentration C (mol / m ³ ) of all cationic surfactants is
3.6 ≦ R, a coating liquid characterized by In the coating liquid applied to the long belt-like web is a composition containing both an anionic surfactant and a cationic surfactant,
The molar concentration A (mol / m ³ ) of all anionic surfactants contained in the coating solution,
The ratio R (= A / C) to the molar concentration C (mol / m ³ ) of all cationic surfactants is
A coating solution, wherein R <1. The coating liquid according to claim 11 or 12, wherein the molar concentration A (mol / m ³ ) of the anionic surfactant is 1.5 mol / m ³ or more. The coating liquid according to claim 11, wherein a dynamic surface tension of the coating liquid at 100 msec is 40 mN / m or less.

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