JPS61164680A - Formation of multi-layered film - Google Patents

Abstract

PURPOSE:To make it possible to efficiently use energy, by simultaneously coat ing a continuously running flexible support with two or more of non-aqueous layers in a multilayered form and irradiating the formed coating layers with electron beam to cure or thicken the same before drying. CONSTITUTION:Two or more kinds of non-aqueous coating solutions are supplied to a coating head 1 from liquid tanks by quantitative liquid supply pumps P1, P2 or P1, P2, P3 to be applied to a web 3 continuously running through an extrusion bead part 2. A least one kind coating solution of two or more kinds of the non-aqueous coating solutions contains 2-30wt% of an electron curable compound on the basis of the solid thereof. The multilayered coating layer is irradiated with electron beam at an electron beam irradiation speed capable of preventing the generation of the convection in the coating film in a first stage electron beam irradiation apparatus 11 to thicken the coating film. Subse quently, electron beam is allowed to irradiate the coating film by a second stage electron beam irradiation apparatus 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for forming a multilayer coating film, and more particularly, the present invention relates to a method for forming a multilayer coating film, and more particularly, the present invention relates to a method for forming a multilayer coating film, and more particularly, the present invention relates to a method for forming a multilayer coating film. The present invention relates to a method of forming a coating film by applying multiple layers of a non-aqueous coating liquid to prevent mutual diffusion and mixing between the layers.

[Prior art]

Conventionally, when a slide hopper type coating device or an extrusion hopper type coating device was used to simultaneously apply multiple layers of organic solvent-based coating liquid and dry it, the coating liquid had a low surface tension, and aqueous solution Due to simultaneous multi-layer coating and the absence of a different schizol-gel conversion process, diffusion mixing between layers tends to occur in the beat area, during coating and drying, and it is extremely difficult to obtain a coating film with each layer separated. It is known to be difficult. For this reason, a method has been used to form organic solvent-based multilayer coatings by sequentially repeating coating and drying for each seven layers.

Sequential coating and drying methods include a method of winding up after each coating and drying, and a method of providing multiple coating and drying sections and coating and drying continuously, but the former method takes a lot of manufacturing time and requires a large amount of time. Therefore, a large amount of manufacturing cost is required, and the latter method requires coating sections and drying sections equal to the number of layers, and requires extremely expensive manufacturing equipment, resulting in a large manufacturing cost.

Incidentally, in recent years, several coating film forming methods have been proposed that utilize the phenomenon of curing of coating films by electron beam irradiation. Tokuko Akira! ≠−lrit22 layer publication and Japanese Patent Application Publication No. 2003-1993-3 are the above-mentioned method for a single layer coating film, and
/A-Hiro No. 03 and JP-A-5R-24T3R are the above-mentioned methods for multilayer coatings, but even though the coating is multilayer, the coatings are applied sequentially and actinic rays are sequentially irradiated. Therefore, the above-mentioned problems cannot be fundamentally solved.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a coating film forming method that is extremely low cost compared to the conventional high cost non-aqueous multilayer coating film forming method.

Another object of the present invention is to provide a method for forming a multilayer coating without interlayer mixing even in thin layers.

Still another object is to provide a non-aqueous coating film forming method that eliminates the use of energy that interferes with the formation of multilayer coatings and enables efficient energy use.

[Means for solving problems]

The above object of the present invention is to provide a coating composition in which at least seven of the non-aqueous layers on a single-layer board contain an electron beam curable resin, and two or more layers are coated on a continuously running flexible support. In a method of forming a coating film by simultaneously applying multiple layers of the non-aqueous I-, irradiating it with an electron beam, curing or thickening the coating layer, and then drying it, the electron beam irradiation rate in the electron beam irradiation is This is achieved by a method of forming a multilayer coating, which is characterized in that the coating layer increases successively in the longitudinal direction of the flexible support.

As the electron beam curable compound that can be contained in the non-aqueous coating liquid in the present invention, various known compounds that are cured by -electron beam irradiation can be used.

Among these compounds, particularly preferred compounds have an unsaturated bond or an epoxy group that can be polymerized by electron beams, such as a compound having seven vinyl or vinylidene carbon-carbon double bonds or an epoxy group, preferably one or more. compounds containing acryloyl groups, acrylamide groups, allyl groups, vinyl ether groups, vinyl thioether groups, etc., and compounds such as unsaturated polyesters and epoxy resins.

Particularly preferred compounds are those having the above-mentioned unsaturated bonds, and are compounds having acryloyl or methacryloyl groups at both ends of the linear chain, and these include A, Vranc
ken Fatipec Congress'/I
Quoted in /ri (lri 7). For example, the polyester skeleton of the exemplified compound may be a polyurethane skeleton, an epoxy resin skeleton, a polyether skeleton, a polycarbonate skeleton, or a mixture thereof. Moreover, the terminal of the illustrated compound may be a methacryloyl group. The molecular weight is preferably about 100-20,000.

Among these compounds, commercially available ones include:
There are Aroex M≦700°M7100 made by Toagosei.

Furthermore, a seven-carbon compound having a carbon-carbon unsaturated bond in its molecule
is also preferable. Such monomers include, for example, acrylic acid, methacrylic acid, itaconic acid, methyl acrylate and its homologues, acrylic acid alkyl esters, methyl methacrylate and its homologs, methacrylic acid alkyl esters, styrene and its homologs. Examples include α-methylstyrene, β-chlorostyrene, acrylonitrile, methacrylate, acrylamide, methacrylamide, vinyl acetate, vinyl zolopionate, and the like. There may be two or more unsaturated bonds in the molecule. An example of such a compound is the "Photosensitive Resin Data Collection"
■Comprehensive Chemical Research Institute, Showa 4C3, monthly publication -2j j-
Examples include compounds listed on page J J J. In particular, unsaturated esters of polyols, such as -monohydroxyethyl acrylate, co-hydroxyethyl methacrylate, ethylene glycol diacrylate, phthoxyethyl acrylate, l,≠-butanediol diacrylate, 'tj-hexanediol acrylate, stearyl acrylate , coethylhexyl acrylate, tetrahydrofurfuryl methacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, tetraethylene glycol diacrylate, neopentyl glycol dimethacrylate, neointhyl glycol diacrylate, glycerol trimethacrylate, trimethylol zolo/montriacrylate, Preferred are pentaerythritol triacrylate, ethylene glycol dimethacrylate, hantaerythritol tetramethacrylate, dipentaerythritol hexaacrylate, and glycidyl methacrylate having an epoxy ring.

The flexible support used in the present invention includes paper, plastic film, metal, resin coated paper, synthetic paper and the like. Examples of the material of the plastic film include polyolefins such as polyethylene and polypropylene, vinyl polymers such as polyvinyl acetate, polyvinyl chloride, and polystyrene, polyamides such as 4, J-nylon, and T-nylon, polyethylene terephthalate, and polyethylene-2°. Polyester such as t-su7 tallate, polycarbo $-), -1! :, I+/low triacetate, cellulose acetate such as cellulose diacetate, etc. are used. Further, the resin used for resin coachitic paper is typically polyolefin such as polyethylene, but is not necessarily limited thereto.

The present invention includes at least one of two or more non-aqueous coating liquids containing an electron beam curable compound, and after applying the coating liquid in multiple layers, irradiation with an electron beam is performed by sequentially increasing the irradiation speed. This is a characteristic feature.

The electron beam irradiation rate means the amount of electron beam irradiation that an irradiated object receives per unit time, and is also referred to as irradiation intensity or dose rate.

The transition of the degree of mixing between the coated layers with respect to the electron beam irradiation time is shown in FIG. In FIG. 3, the dot-dash dots indicate the change in the degree of mixing between layers when the electron beam irradiation rate is large, the dotted line shows the change in the degree of mixing between the layers when the electron beam irradiation rate is small, and the solid line shows the changes in the degree of mixing between the layers when the electron beam irradiation rate is small. The graph shows the change in the degree of mixing between the layers.

If the electron beam irradiation rate is high, not only will there be a large loss of electron beam energy, but also rapid evaporation of the solvent will occur, especially at the beginning of the electron beam irradiation process, and the heat of evaporation and the heat of the electron beam energy will increase. As a result of the temperature rise caused by the conversion, convection occurs in the coating film, making it impossible to obtain a coating film with the desired layer separation. On the other hand, if a small value is adopted as the electron beam irradiation rate to avoid the above-mentioned phenomenon, the curing or thickening of the electron beam-curable compound-containing layer will be slow.
, or it does not occur, and diffusion mixing occurs between the multiple coating layers, and the desired coating film is not formed.

The method of the present invention can be carried out using an apparatus as shown in FIG. However, the present invention is not limited to such extrusion bead coating, and can also be carried out by slide bead coating, hollow-slide coating, curtain coating, etc.

From a liquid tank (not shown in FIG. 1), a non-aqueous coating liquid of 7 or more types is supplied to the coating head l by metering liquid pumps P1, P2 or P1, P2, P3, etc. At , it is applied to the continuously running web 3. ! is the application part packing roll, A, 7
, r is the pass roll. In addition, ≠ is a decompression chamber or a vacuum pump (not shown) to make the bead stable. /l is the first stage electron beam irradiation device, /J is the first stage electron beam irradiation device. The first stage is an electron beam irradiation device, and 13 is a drying device.

In the present invention, at least '
411 types contain electron beam curable compounds. The content is not particularly limited, but is generally appropriate to be about λ~30% by weight based on the solid content of the coating liquid. Further, the viscosity of the coating liquid used in the present invention is not particularly limited.

At the extrusion bead part λ, the multi-layered coating layers are simultaneously coated with electron beams at a low electron beam irradiation rate that can prevent the generation of convection in the coating film in the first stage electron beam irradiation device. Ray irradiation is performed to thicken the coating film to a viscosity that can prevent the occurrence of convection, and then in the second stage electron beam irradiation device/J, the electron beam irradiation rate is higher than the first stage electron beam irradiation rate. When irradiated with an electron beam, the layer containing the electron beam curable compound is hardened or thickened while preventing the occurrence of convection in the multilayer coating, and diffusion mixing between the multilayer coatings is suppressed. , furthermore, a drying device/
3 to form the desired multilayer coating.

Although FIG. 1 shows an example in which the electron beam irradiation rate changes in λ steps, it may change in three or more steps.

The method of the invention is used to produce multilayer coating materials having at least two non-aqueous coating layers on a flexible support. Such multilayer coating materials include, but are not limited to, various multilayer photographic materials, multilayer analytical materials, and the like. For example, as a specific example of a photosensitive material for a lithographic printing plate having at least multiple non-aqueous coating layers, of which at least seven layers are photosensitive layers, which is suitable for production by the method of the present invention, there are Publication No. 1022, Special Publication Shoj
The one having an 0-quinonediazide photosensitive layer and a resin layer described in G-JIAIjt publication, JP-A-1T-IA
The one having a λ layer of the 0-quinonediazide photosensitive layer described in the trzt publication, JP-A-Sho #/-tt3iλ! The one having the 0-quinonediazide photosensitive layer and the azide compound photosensitive layer described in the Japanese Patent Publication No. Sho J7-//! Examples include those having a photosensitive material layer and an organic resin layer as described in Publication No. II, and those having an 0-quinonediazide photosensitive layer and an electrophotographic photosensitive layer as described in Japanese Patent Application Laid-Open No. 7-206. It will be done.

〔Example〕

Using the apparatus shown in FIG. 1, 1 joule of the coating liquid having the composition and physical properties shown in Table 1 was applied to a polyethylene terephthalate film having a width of -00 μm and an upper layer of 1 j CC/m2 and a lower layer/O
Multi-layer coating was applied with a coating amount of CC/7X 2, and the acceleration voltage was 2j OKv at the point where / seconds had passed after coating.

The first stage of electron beam irradiation was performed in the electron beam irradiation device/l so that the irradiation amount/Mrad and the irradiation speed were □Mrad 7 seconds, and the acceleration voltage λJ-OKV.

After performing the second stage of electron beam irradiation in the electron beam irradiation device/λ so that the irradiation amount was 2 Mrad and the irradiation speed was 4 A□ Mrad 7 seconds, the drying device 13 was used to perform I? It was heated and dried at 00C.

Table 1 [Comparative Example] Multi-layer coating was performed using the same equipment, coating solution, film, and coating amount as in the example, and after coating (acceleration voltage KO! OKv at the second point, irradiation amount J Mrad, irradiation speed 11 & OMrad/ After electron beam irradiation was carried out in the electron beam irradiation device// so that the temperature was 2 seconds, the film was heated and dried in the drying device/3 at a low QoC.

The buffy coat obtained in Examples and Comparative Examples was subjected to ESCA (Elec
tron 5pectroscopy iorCh
Chlorine in the cresol resin detected in the upper layer while scraping was analyzed using a chemical analysis method. The distribution of the detected amount is shown in FIG. In FIG. 1, the solid line shows the sample measurement results of the example, and the dotted line shows the sample measurement results of the comparative example. As a result, in this example, since the electron beam irradiation speed changed in the longitudinal direction of the support and increased sequentially, the obtained sample was as shown by the solid line in Figure 2.
It turned out that cresol resin remained unevenly distributed,
On the other hand, in the comparative example, it was found that the cresol resin was distributed throughout the entire layer of the obtained sample due to mixing, as shown by the dotted line. As described above, in the method of the present invention, the cresol resin was found to be unevenly distributed in the original layer, clearly demonstrating the effects of the present invention.

〔Effect of the invention〕

According to the present invention, as confirmed in the above examples, in non-aqueous multilayer coating, diffusion mixing between layers is suppressed and a multilayer coating film is formed, which simplifies the process and reduces costs. . Further, according to the present invention, it is possible to form a multilayer coating film without interlayer mixing even if it is a thin layer. Furthermore, according to the present invention, it is possible to eliminate the use of energy that would interfere with the formation of a multilayer coating film, making it possible to use energy efficiently.

[Brief explanation of drawings]

FIG. 1 is a side view of an apparatus for carrying out the method for forming a portal membrane according to the present invention, and FIG. 1 is a characteristic diagram showing the effects of the present invention. FIG. 3 is a characteristic diagram showing the principle of the present invention. L...Coating head C...Extrusion bead part 3...Web /C...First stage electron beam irradiation device /C...Second stage electron beam irradiation device
/3... Drying device patent applicant Fuji Photo Film Co., Ltd. Figure 2 Figure 3 Date of March 1985 -

Claims (2)

[Claims] (1) At least one of the two or more nonaqueous layers is a coating composition containing an electron beam curable resin, and the two or more nonaqueous layers are coated on a continuously running flexible support. In a method in which a coating film is formed by simultaneously applying multiple layers, irradiating the coating layer with an electron beam, curing or thickening the coating layer, and then drying, the electron beam irradiation speed in the electron beam irradiation is A method for forming a multilayer coating film that changes in the longitudinal direction of the body. (2) The method for forming a multilayer coating film according to claim 1, wherein the electron beam irradiation rate in the electron beam irradiation increases sequentially in the longitudinal direction of the flexible support.