JPH05277415A - Method and apparatus for producing film member - Google Patents

Abstract

PURPOSE:To obtain a magnetic recording medium rich in surface smoothness at a low cost by providing a coating process applying paint to a support, a smoothing process applying smoothing treatment to a coating layer and an ultrasonic vibration process allowing ultrasonic vibration to act. CONSTITUTION:Magnetic paint 3 is thinly and uniformly applied to one surface of the base film sent from a supply roll 4 at a high speed by the gravure roll 2 arranged to a backup roll 1 and the coated magnetic paint is subjected to smoothing treatment after gravure coating. This smoothing treatment is performed by the roll 6 arranged to the surface on the side opposite to the magnetic film layer of the base film and the flexible sheet 7 arranged in opposed relation to the roll 6. At this time, ultrasonic vibration is applied to the roll 6 from an ultrasonic oscillator and, by this ultrasonic vibration, the leveling of the paint constituting the film layer is performed and smoothing effect is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method and a manufacturing apparatus for a coated body such as a magnetic recording medium or a thermal transfer ribbon.

[0002]

BACKGROUND OF THE INVENTION For example, a magnetic recording medium such as a magnetic tape or a magnetic disk generally has a magnetic coating material obtained by kneading a magnetic powder, a binder, other various additives and a solvent, and a base film such as a polyester film. (Non-magnetic support)
It is manufactured through various processes such as coating, smoothing, orientation, drying and cutting. A means such as a gravure coater is used for applying the magnetic paint. That is, the magnetic coating is thin on the base film by the gravure roll arranged with respect to the backup roll, and
It is applied uniformly at high speed. Then, smoothing is performed after this gravure coating.

By the way, depending on the gravure roll, smoothing treatment may not be performed effectively, and the gravure pattern may not disappear. Further, there is a problem that the production yield is lowered due to the formation of streak patterns along the longitudinal direction of the tape.

[0004]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a technique in which smoothing is effectively carried out and the production yield of a coating film body is high. The object of the present invention is to perform a coating process of coating a coating material on a support, a smoothing process of smoothing a coating layer formed by coating, and an ultrasonic vibration process of applying ultrasonic vibration in this smoothing process. It is achieved by a method for producing a coated film characterized by comprising:

Further, it is provided with a coating device for coating the support with a coating material, a smoothing device for smoothing a coating layer formed by coating, and an ultrasonic vibration device for applying ultrasonic vibration to the smoothing device. It is achieved by an apparatus for producing a coating film body characterized by the above. Hereinafter, the present invention will be described in detail with a magnetic recording medium as a typical example.

As the magnetic powder used for the paint (magnetic paint), ferromagnetic iron oxide, ferromagnetic chromium dioxide, ferromagnetic alloy powder, etc. can be used. A divalent metal may be added to the ferromagnetic iron oxide. Cr, M as the divalent metal
There are n, Co, Ni, Cu, Zn and the like, which can be added in the range of, for example, 1 to 10 atomic% with respect to the iron oxide. Ferromagnetic chromium dioxide is CrO ₂ and Na, K, T
i, V, Mn, Fe, Co, Ni, Tc, Ru, Sn,
A metal such as Ce or Pb, a semiconductor such as P, Sb or Te, or Cr containing 0 to 20% by weight of an oxide of these metals added.
0 ₂ can be used. In particular, in the above-mentioned ferromagnetic iron oxide and ferromagnetic chromium dioxide, the acicular ratio is 2/1 to 20 /
1 or more, preferably 5/1 or more, and the average length is 0.1 to 2.
Those of 0 μ can be used. The above ferromagnetic alloy powder has a metal content of 75 wt% or more, and 80 wt% or more of the metal content is at least one ferromagnetic metal (for example, Fe, Co, Ni, Fe-Co, Fe-Ni, Co
-Ni, Fe-Co-Ni), wherein the metal content is 20% by weight or less, and preferably 0.5 to 5% by weight is Al,
Si, S, Sc, Ti, V, Cr, Mn, Cu, Zn,
Y, Mo, Rh, Pd, Ag, Sn, Sb, Te, B
a, Ta, W, Re, Au, Hy, Pb, Bi, La,
It may have a composition such as Ce, Pr, Nd, B and P. This ferromagnetic alloy powder has a major axis of 0.5μ.
It is preferable that the particle size is m or less. Further, barium ferrite in the form of a small flat plate and part of its Fe atoms are Ti and C.
It is also possible to use magnetic powders substituted with one kind or two kinds or more of o, Zn, V, Nb and the like.

As a binder (binder) used in the construction of the coating layer (magnetic coating layer), a thermoplastic resin, a thermosetting resin, a reactive resin or a mixture thereof can be used in combination. For example, as the thermoplastic resin, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-
Vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, acrylic acid ester-acrylonitrile copolymer, acrylic acid ester-vinylidene chloride copolymer, acrylic acid ester-styrene copolymer, methacrylic acid ester-acrylonitrile copolymer , Methacrylic acid ester-vinylidene chloride copolymer, methacrylic acid ester-styrene copolymer, urethane elastomer, polyvinyl fluoride, vinylidene chloride-acrylonitrile copolymer, butadiene-acrylonitrile copolymer, polyamide resin, polyvinyl butyral, cerose Derivatives (cellulose acetate butyrate, cellulose diacetate, cellulose triacetate, cellulose propionate, nitrocellulose, etc.), styrene-butadiene copolymer, polyester Fat, thermoplastic resins a synthetic rubber type (polybutadiene, polychloroprene, polyisoprene, styrene - butadiene copolymer), and mixtures thereof. As the thermosetting resin or reactive resin, phenol / formalin-novolak resin, phenol / formalin / resole resin, phenol / furfural resin, xylene / formaldehyde resin, urea resin, melamine resin, drying oil modified alkyd resin, carboxylic acid modified resin Alkyd resin, maleic acid resin-modified alkyd resin, unsaturated polyester resin, epoxy resin and curing agent (polyamine, acid anhydride, polyamide resin, etc.), terminal isocyanate polyester moisture curing type resin, terminal isocyanate polyether moisture curing type resin, Polyisocyanate prepolymer (compound having three or more isocyanate groups in one molecule obtained by reacting diisocyanate with low molecular weight triol, trimer and tetramer of diisocyanate), po Isocyanate prepolymer and resin having active hydrogen (polyester polyol, polyether polyol, acrylic acid copolymer, maleic acid copolymer, 2-hydroxyethyl methacrylate copolymer, parahydroxystyrene copolymer, etc.), and these A mixture etc. are mentioned. These binder resin components are used in an amount of about 10 to 100 parts by weight, preferably 5 to 30 parts by weight, based on 100 parts by weight of the magnetic powder.

In the coating layer (magnetic coating layer), in addition to the above-mentioned components, as additives usually used in the field of magnetic recording media, dispersants, lubricants, abrasives, antistatic agents, rust preventives, A fungicide or the like may be added. The dispersant has 12 to 12 carbon atoms.
18 fatty acids (R ₁ COOH, R ₁ has 11 to ₁ carbon atoms
7 alkyl or alkenyl groups), a metal soap composed of the above-mentioned fatty acid alkali metal (Li, Na, K, etc.) or alkaline earth metal (Mg, Ca, Ba, etc.), and the above-mentioned fatty acid ester fluorine. Examples thereof include compounds, amides of the above fatty acids, polyalkylene oxide alkyl phosphates, lecithin, and trialkylpolyolefinoxy quaternary ammonium salts (alkyl has 1 to 5 carbon atoms, olefin has ethylene, propylene, etc.) and the like. In addition to these, there are higher alcohols having 12 or more carbon atoms, sulfuric acid esters and the like. These dispersants may be added in an amount of 10 parts by weight or less based on 100 parts by weight of the magnetic powder.

As the lubricant, the above-mentioned dispersant is also effective, but dialkyl polysiloxane (where the alkyl group has 1 carbon atom)
~ 5), dialkoxy polysiloxane (alkoxy group has 1 to 4 carbon atoms), monoalkyl monoalkoxy polysiloxane (alkyl group has 1 to 5 carbon atoms, alkoxy group has 1 to 4 carbon atoms), phenyl Polysiloxane, fluoroalkylpolysiloxane (alkyl group has 1 to 5 carbon atoms
Individual) silicone oil, conductive fine powder such as graphite, inorganic fine powder such as molybdenum disulfide and tungsten disulfide, plastic fine powder such as polyethylene, polypropylene, polyethylene-vinyl chloride copolymer, polytetrafluoroethylene, etc. α-Olefin polymer, unsaturated aliphatic hydrocarbon which is liquid at room temperature, fatty acid ester consisting of monobasic aliphatic having 12 to 20 carbon atoms and monohydric alcohol having 3 to 12 carbon atoms, fluorocarbons, etc. Is mentioned. These lubricants are added in the range of 0.1 to 15 parts by weight with respect to 100 parts by weight of the magnetic powder.

Examples of the abrasive include fused alumina, silicon carbide, chromium oxide (Cr ₂ O ₃ ), corundum, artificial corundum, diamond, artificial diamond, garnet, emery (main components: conradam and magnetite). As these abrasives, those having a Mohs hardness of 5 or more and an average particle diameter of 0.05 to 5 μm are used, and particularly preferably 0.1 to 2 μm. And, these abrasives are 0.5 to 1 with respect to 100 parts by weight of the magnetic powder.
It is added in the range of 5 parts by weight.

As the antistatic agent, conductive fine powder such as carbon black, natural surfactant such as saponin, nonionic surfactant such as alkylene oxide type, glycerin type and glycidol type, higher alkylamines, quaternary ammonium Salts, pyridine and other heterocycles, cation surfactants such as phosphonium or sulfonium, anionic surfactants containing carboxylic acid, sulfonic acid, phosphoric acid, sulfuric acid ester group, acid group such as phosphoric acid ester group, amino acids, amino sulfone Examples thereof include amphoteric activators such as acids and sulfuric acid or phosphoric acid esters of amino alcohols. Such conductive fine powder is added in the range of 0.01 to 10 parts by weight with respect to 100 parts by weight of magnetic powder. You may add the said surfactant individually or in mixture. Although these are used as antistatic agents, they are sometimes used for other purposes such as dispersion, improvement of magnetic properties, improvement of lubricity, and coating aid.

As the rust preventive agent, phosphoric acid, sulfamide, guanidine, pyridine, amine, urea, zinc chromate, calcium chromate, strontium chromate and the like can be used, but especially dicyclohexylamine nitrite, cyclohexylamine chromate, diisopropylamine nitrite, Volatile rust inhibitors such as diethanolamine phosphate, cyclohexylammonium carbonate, hexamethylenediamine carbonate, propylenediamine stearate, guanidine carbonate, triethanolamine nitrite, morpholine stearate (inorganic acid salts or organic acids of amines, amides or imides) Use of (salt) improves the rust prevention effect. These rust preventives are 0.0 per 100 parts by weight of the ferromagnetic fine powder.
It is used in the range of 1 to 20 parts by weight.

Antifungal agents include saltylanilide, bis (tributyltin oxide), mercury phenyloleate, copper naphthenate, zinc naphthenate, mercury naphthenate, pentachlorophenol, trichlorophenol, p-dinitrophenol, sorbic acid, There are butyl p-oxybenzoate, dihydroacetate and the like, and they are used in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the binder.

Materials for the non-magnetic support used in the magnetic recording medium include polyesters such as polyeletin terephthalate and polyethylene-2,6-naphthalate, polyolefins such as polyethylene and polypropylene, cellulose triacetate and cellulose diacetate. Cellulose derivatives such as cellulose acetate butyrate and cellulose acetate propionate, vinyl resins such as polyvinyl chloride and polyvinylidene chloride, plastics such as polycarbonate, polyimide and polyamide-imide, paper, baryta or polyethylene, polypropylene, ethylene- Papers such as papers coated or laminated with α-polyolefins having 2 to 10 carbon atoms such as butene copolymers can also be used. These non-magnetic supports may be transparent or opaque depending on the purpose of use.

Solvents used for the production of paints (magnetic paints) include acetone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, glycol acetate monoethyl ether, etc. Ester-based solvent,
Ether, glycol dimethyl ether, glycol monoethyl ether, glycol ether type solvents such as dioxane, tar type (aromatic hydrocarbon type) solvents such as benzene, toluene, xylene, methylene chloride, ethylene chloride, carbon tetrachloride, chloroform, A chlorinated hydrocarbon solvent such as ethylene chlorohydrin or dichlorobenzene can be appropriately selected and used.

Magnetic powder, binder and the like are kneaded to form a magnetic coating material. At the time of kneading, the magnetic powder and the above-mentioned components are all introduced into the kneader at the same time or individually. In kneading and dispersing this magnetic coating material, various kneading machines such as a two-roll mill, a three-roll mill, a ball mill, a pebble mill, a tron mill, a sand glider,
Szegvari Attritor, High Speed Impeller Disperser, High Speed Stone Mill, High Speed Impact Mill, Disperser,
It is carried out with a kneader, high speed mixer, homogenizer, ultrasonic disperser or the like.

A gravure coater as shown in FIG. 1 is used to apply the magnetic paint onto the non-magnetic support.
That is, as shown in FIG. 1, the magnetic coating material 3 is thinly and uniformly applied at a high speed on one surface of the base film fed from the supply side roll 4 by the gravure roll 2 arranged with respect to the backup roll 1. Is applied. The magnetic coating film 5 applied after the gravure coating is smoothed. This smoothing treatment is performed by the roll 6 and the roll 6 arranged on the surface of the base film opposite to the magnetic coating layer.
And the flexible sheet 7 that is disposed so as to face the above. That is, the sheet 7 in which the magnetic coating layer of the magnetic coating 5 traveling between the roll 6 and the sheet 7 is in surface contact
Smoothed by. At this time, ultrasonic vibration (frequency is, for example, about 10 to 200 KH) from an ultrasonic oscillator (not shown) (for example, the ultrasonic oscillator is built in the roll 6 or attached to the side surface of the roll 6).
z) has been added to roll 6. In the present invention, it is considered that the reason why the ultrasonic vibration is applied to the coating film during the smoothing treatment gives a preferable result is as follows. That is, when ultrasonic vibration is applied to the coating film during smoothing treatment, the amplitude of the ultrasonic vibration is extremely small, but it is repeated a huge number of times in a short time. It is considered that the smoothing effect is enhanced by leveling the coating material that constitutes the film layer. In addition, dust is prevented from adhering, and the formation of streaks in the longitudinal direction is also prevented.

After this smoothing treatment, the magnetic coating film 5
Is subjected to an orientation process and a drying process, and is taken up by the take-up roll 8. Then, a magnetic recording medium such as a magnetic tape or a magnetic disk is obtained by cutting into a desired shape and further cleaning. The present invention will be specifically described below with reference to examples.

[0019]

【Example】

[Example 1] 100 parts by weight of metal magnetic powder, vinyl chloride
Vinyl acetate copolymer resin 9 parts by weight, polyurethane resin 9 parts by weight, polyisocyanate compound 4 parts by weight, α-alumina 10 parts by weight, butyl stearate 2 parts by weight, palmitic acid 1 part by weight, carbon black 2 parts by weight, and methyl ethyl ketone. A magnetic paint composed of 400 parts by weight of a mixed solvent of Cyclohexanone and 400 parts by weight of 9.2 μm thick
Figure 1 on a 0 m long polyethylene terephthalate film
A gravure coater as shown in (3) is used to apply 3.2 μm thickness at a coating speed of 60 m / min.

After that, smoothing is performed by a smoother as shown in FIG. Roll 6 is SUS30
A Langevin type vibrator (frequency 60 KHz, output 1.5 KW) is attached to the side surface of the roll 6, and the roll 6 is constantly subjected to ultrasonic vibration. Then, the magnetic tape was manufactured through a normal process.

[Comparative Example 1] The same procedure as in Example 1 was performed except that the power switch of the Langevin type vibrator was turned off. [Characteristics] With respect to the magnetic tapes obtained in each of the above examples, the surface roughness (center line average roughness Ra) of the magnetic coating layer and the streak pattern were not formed, and the production yield of usable products was examined. Shown in 1.

Table 1 Ra (nm) Manufacturing yield (%) Example 1 52 95 Comparative Example 1 274 79 Further, a three-dimensional diagram of the magnetic tape obtained in each of the above examples by a non-contact optical interference method is shown in FIG. Example 1) and FIG. 3 (Comparative Example 1) show that, in the example, the waviness of the coating film surface is extremely small, whereas in the comparative example, the waviness of the coating film surface is large. It can be seen that the eyes of the gravure roll remain.

[0023]

[Effect] A magnetic recording medium having a high surface smoothness can be efficiently obtained at low cost.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an apparatus for manufacturing a magnetic recording medium of the present invention.

FIG. 2 is a three-dimensional view of a magnetic tape obtained by the present invention by a non-contact optical interference method.

FIG. 3 is a three-dimensional view of a magnetic tape obtained by a comparative example by a non-contact optical interference method.

[Explanation of symbols]

 1 Backup roll 2 Gravure roll 3 Magnetic paint 5 Magnetic coating 6 Roll 7 sheet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G11B 5/84 A 7303-5D

Claims (2)

[Claims] 1. A coating process for coating a coating on a support,
A method for producing a coating film body, comprising: a smoothing process of smoothing a coating film layer formed by coating; and an ultrasonic vibration process of applying ultrasonic vibration in the smoothing process. 2. A coating device for coating a coating material on a support,
An apparatus for producing a coating film, comprising: a smoothing device for performing a smoothing treatment on a coating layer having a coating structure; and an ultrasonic vibration device for applying ultrasonic vibration to the smoothing device.