JPH10283628A - Magnetic recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent magnetic recording medium having magnetic recording layers provided with sure magnetic input/output performance and transparency in combination. SOLUTION: At least one layer on the magnetic recording layer side of the magnetic recording medium having at least one layer of the magnetic recording layers contg. magnetic material particles on a base contains inorg. particles and/or org. resin particles. The surface roughness of the magnetic recording layers is specified to >=5 to <=30 nm in Rq. The number of surface projections consisting of particles exclusive of the magnetic particles per 100 μm<2> of the magnetic recording layers is specified to >=30 pieces and the haze degree to <90%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a transparent magnetic recording medium free from magnetic input / output errors.

[0002]

2. Description of the Related Art The magnetic recording layer of a magnetic recording medium such as an audio tape, a video tape, and a floppy disk is
The high magnetic material content (coating amount) provides high magnetic output, but lacks light transmission.
A magnetic recording layer cannot be provided on a photographic film.
U.S. Pat. No. 5,491,051 describes photographic elements having excellent magnetic and photographic properties which can be used repeatedly. However, this photographic element incorporates various information such as shooting date and time, weather, lighting conditions, shooting conditions such as reduction / enlargement ratio, the number of reprints, a portion to be zoomed, a message, etc. developing,
There is a drawback that input / output of magnetic recording information such as printing conditions is not always reliable.

[0003]

In fact, even if an abrasive is used in accordance with the prior art, such as the primary particle size and the amount of magnetic particles, the effect of preventing and removing dirt from being transferred to the magnetic head is not sufficient. Simply increasing the amount of abrasive used or increasing the particle size of the abrasive encounters the problem of extremely low transparency of the medium itself and the problem of reduced magnetic output due to space loss, making it virtually transparent and reliable. Development of a magnetic recording medium capable of magnetic input / output and design of an optimal surface shape of the medium for that purpose have been issues. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a durable transparent magnetic recording medium free of magnetic errors that can reliably input and output various magnetic information even when used repeatedly.

[0004]

According to the present invention, there is provided a magnetic recording medium having a magnetic recording layer containing at least one magnetic particle on a support, wherein at least one layer on the magnetic recording layer side is made of inorganic particles or / and / or the like. And the magnetic recording layer has a surface roughness Rq (root mean square roughness) of 5 nm or more and 30 or more.
nm or less, and the number of surface projections composed of particles other than magnetic particles per 100 μm ^{2 of the} magnetic recording layer is 30 or more, and the haze degree is less than 9%. Is provided. In the present invention, the transparent magnetic recording medium refers to a recording medium having a transparent magnetic recording layer described later.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inorganic particles used in the present invention include aluminum oxide (α-alumina, γ-alumina, corundum, etc.), chromium oxide (Cr ₂ O ₃ ), and iron oxide (α-Fe ₂ O _3). ), Oxides such as silicon dioxide, colloidal silica, titanium dioxide, zinc oxide and tin oxide, carbides such as silicon carbide (SiC), silicon carbide and titanium carbide, fine powders such as diamond, calcium carbonate, aluminum hydroxide, Examples include barium sulfate, strontium barium sulfate, and manganese colloid. Examples of the organic polymer particles include resin particles and starch such as polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropyl methacrylate, polymethyl acrylate, and polyethylene carbonate, and pulverized and classified products thereof. .

Also, acrylic esters, methacrylic esters, itaconic diesters, crotonic esters, maleic diesters, phthalic diesters, styrene derivatives, vinyl esters, acrylamides, vinyl ethers, allyl compounds, vinyl ketones, vinyl diesters Monomers such as articulated compounds, allyl compounds, acrylonitrile, methacrylonitrile, polyfunctional monomers, etc.
The polymer compound of a kind or two or more kinds of polymers may be formed into particles by various means such as a suspension polymerization method, a spray drying method, or a dispersion method. other,
Examples include a siloxane resin and a benzoguanamine resin.

The preferred surface morphology of the present invention, which can be obtained by incorporating these particles in the back layer, will be described below. The surface roughness of the back layer is 5 nm or more and 30 in Rq.
nm or less, preferably 10 nm or more and 25 nm or less. After satisfying the above surface roughness, the number of surface protrusions is 30 per 100 μm ² in order to instantly remove dirt on the magnetic head and trap dirt adhering to the medium side between the protrusions and not transfer them to the magnetic head. It is necessary.

[0008] In order to achieve the above surface shape, the particles are preferably contained in the transparent magnetic recording layer or / and the layer adjacent to the transparent magnetic recording layer. Even if the particles are used alone, a sufficient effect can be seen, but the particles contain at least two kinds (including the case where the same kind of material has a different particle diameter), and the average primary particle diameter of at least one of the particles is 0.2%. ~
Preferably, the average primary particle diameter of at least one particle is 0.01 to 0.15 μm. More preferably, the average primary particle diameter of at least one particle is 0.2 to 0.3 μm, and the average primary particle diameter of at least one particle is 0.01 to 0.10 μm. More preferably, the hardness of the former particles is 7 or more and the Mohs hardness of the latter particles is 7 or less. As particles having a Mohs hardness of 7 or more, for example, silicon dioxide,
There are zirconium oxide, chromium oxide, aluminum oxide, diamond, silicon carbide, titanium carbide, tungsten carbon, titanium nitride, and the like. For details, see, for example, “Ha
ndbookof Chemistry & Phys
s. 62 edition ". Among them, it is preferable that α-alumina having a Mohs' hardness of 9 is contained in that the magnetic head can be sufficiently polished. More preferably, the former particles are α-alumina and the latter particles are metal oxides having a Mohs hardness of 7 or less.

When the large particles come into contact with the magnetic head, they have the function of polishing the head to remove dirt.
The small particles are present between the large particles and have the effect of trapping fine dirt on the medium and not transferring this to the magnetic head. Particularly in the case of a transparent magnetic recording medium having a silver halide emulsion layer accompanied by development processing, thirst of the processing solution (dirt)
Is finely dispersed (trapped) between the projections of the small particles, and the function of preventing the magnetic head from contacting the dirt with the large particles is clearly exhibited. The amount of these particles used is such that the total of the large particles and the small particles is 1 wt. % Or more and 20 wt. %
It is desirable that: The ratio of large particles to small particles is such that the weight ratio of large particles to small particles is usually 1: 0.1 to 1: 100,
Preferably it is 1: 0.2 to 1:30, more preferably 1: 0.3 to 1:10.

Although the use of the above particles slightly lowers the transparency as compared with the case where they are not used, if the magnetic recording medium of the present invention is provided on a photographic film, the haze of all the back layers is reduced. The degree is required to be 9% or less from the viewpoint of photographic performance, and more preferably 7% or less. The average primary particle diameter of the particles used is 0.01 μm
Those having a size of at least 0.4 μm or less are easily available and have a uniform particle size, which is preferable for obtaining the fine surface morphology of the present invention. At this time, the particles (2
(Including secondary particles) is preferably 0.7 μm or less. The magnetic head can be extremely uniformly contacted, and a post-process such as calendering (mirror finishing) is not required. Such particles are preferably slurried singly or in a plurality, and added and mixed with the coating solution of the layer to be incorporated, since the stability of the coating solution and the like are preferably widened.

The transparent magnetic recording layer refers to a magnetic recording layer having a degree of transparency that does not substantially affect photographic image quality.
0 to 0.2, preferably 0, in blue filter transmission density
To 0.15, more preferably 0 to 0.10.

The magnetic particles contained in the transparent magnetic recording layer used in the present invention include ferromagnetic iron oxide (FeOx, 4/3 <x ≦ 3/2) such as γ-Fe ₂ O ₃ , -Fe ₂ O
₃ or other Co-coated ferromagnetic iron oxide (FeOx, 4/3 <x ≦
3/2), Co-coated magnetite, other Co-containing ferromagnetic iron oxide, Co-containing magnetite, ferromagnetic chromium dioxide, ferromagnetic metal, ferromagnetic alloy, and other ferrites such as hexagonal Ba ferrite, Sr Ferrite, Pb ferrite, Ca ferrite, or a solid solution or ion substitute thereof can be used.

The shape of the ferromagnetic material may be any of a needle shape, a rice grain shape, a spherical shape, a cubic shape, a plate shape, and the like, but a needle shape is preferable in terms of electromagnetic conversion characteristics. The specific surface area of the particles is 20 m ^{2 in} SBET.
/ G or more, more preferably 30 m ² / g or more. When the particle size is needle-shaped, the major axis is 0.01 to 0.1.
8 μm, the short axis is 0.005 to 0.4 μm, and the ratio of the long axis to the short axis is preferably 100: 1 to 2: 1.
4 to 0.4 μm, the short axis is more preferably 0.01 to 0.1 μm, and the ratio of the long axis to the short axis is more preferably 100: 1 to 3: 1. It is preferable that the particle size distribution of the magnetic material be as sharp as possible.

The saturation magnetization (σs) of the ferromagnetic material is 50 emu / g
It is more preferably 70 emu / g or more. Also,
The squareness ratio (σr / σs) of the ferromagnetic material is preferably 40% or more, more preferably 45% or more. Coercive force (Hc) is 200 Oe
Not less than 3000 Oe, preferably not less than 500 Oe and not more than 20
00 Oe or less.

These ferromagnetic particles are described in, for example,
Surface treatment may be carried out with silica and / or alumina, such as those described in 9-23505 and JP-A-4-096052. Further, Japanese Patent Application Laid-Open Nos. 4-195726 and 4-1
92116, 4-259911, 5-081652
A surface treatment with an inorganic and / or organic material as described above may be performed. Further, the surface of these ferromagnetic particles may be treated with a silane coupling agent or a titanium coupling agent. Examples of the coupling agent include 3-mercaptopropyl trimethoxysilane, 3
-Isocyanylpropyl methyldimethoxysilane, 3
-(Poly (degree of polymerization 10) oxyethynyl) oxypropyl trimethoxysilane, 3-methoxy (poly (degree of polymerization 6) oxyethynyl) oxypropyl trimethoxysilane, decyltrimethoxysilane and the like are used. The addition amount of these silane coupling agents and titanium coupling agents to the magnetic particles is 1.0 to 200% by weight. Preferably it is 1 to 75% by weight, more preferably 2 to 50% by weight. These silane coupling agents and titanium coupling agents are treated by a direct treatment method for magnetic particles or an integral blending method, and the direct methods include a dry method, a slurry method, and a spray method. In the dry method, for example, magnetic particles and a small amount of water, or an organic solvent, or an organic solvent containing water and a coupling agent are mixed and stirred with an open kneader to remove water and the organic solvent, and then finely dispersed. Is preferred.

The method of dispersing the magnetic material in a binder described later is preferably a kneader, a pin mill, an annular mill, or the like, and more preferably a kneader and a pin mill, or a combination of a kneader and an annular mill. Examples of the kneader include an open type (open), a closed type, a continuous type, and a kneader such as a three-roll mill and a Labo Plast mill.

The thickness of the magnetic recording layer is 3 μm or less, preferably 2 μm or less, more preferably 1.5 μm or less. The weight ratio of magnetic particles to binder is preferably 0.5: 10
0-60: 100, more preferably 1: 100
３０30: 100. The coating amount as a magnetic material is 0.0
05-0.3 g / m ² , preferably 0.01-0.15 g / m
m ² , more preferably 0.02 to 0.1 g / m ² . The coercive force of the film with the magnetic recording layer is 500 O
e to 3000 Oe, preferably 800 Oe to 1
It is 500 Oe or less.

The magnetic recording layer can be provided on the entire surface of the photographic support or in the form of stripes. If necessary, the magnetic recording layer applied on the support is subjected to a process of immediately orienting the magnetic material in the layer while drying, and then the formed magnetic recording layer is dried. There is a method using a permanent magnet or a solenoid coil to orient the magnetic material. The strength of the permanent magnet is preferably 2000 Oe or more, and particularly preferably 3000 Oe or more. In the case of a solenoid, it may be 500 Oe or more. The timing of orientation during drying is desirably at a point where the residual solvent in the magnetic recording layer is 5% to 70%.

The magnetic recording layer has improved lubricity, curl control,
Functions such as antistatic, antiadhesion, head polishing, and dust adhesion prevention may be combined.

The binder for the magnetic recording layer and the like used in the present invention is a thermoplastic resin, a thermosetting resin, a reactive resin, an acid,
Alkali or biodegradable polymers, natural polymers (cellulose derivatives, sugar derivatives, etc.) and mixtures thereof can be used. Preferred Tg of the above resin is-
40 ° C. to 300 ° C., weight average molecular weight: 2,000 to 100
And more preferably 50,000 to 300,000.

As the above thermoplastic resin, vinyl chloride
Vinyl acetate copolymer, vinyl chloride, copolymer of vinyl acetate and vinyl alcohol, maleic acid and / or acrylic acid, vinyl chloride / vinylidene chloride copolymer, vinyl chloride / acrylonitrile copolymer, ethylene / vinyl acetate copolymer Vinyl copolymers such as polymers, nitrocellulose, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, hydroxypropylcellulose, ethylcellulose, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, acetyldibutylacetate, triacetate Cellulose derivatives such as propionyl acetate, didodecyl acetate, acrylic resin, polyvinyl acetal resin, polyvinyl butyral resin, polyether Rubber resins such as terpolyurethane resin, polyether polyurethane, polycarbonate, polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, styrene butadiene resin, butadiene acrylonitrile resin, silicone resin, and fluorine resin. it can.

The thermosetting resin or the reactive resin is, for example, a phenol resin, a phenoxy resin, an epoxy resin,
Curable polyurethane resin, urea resin, melamine resin, alkyd resin, silicone resin, acrylic reaction resin, epoxy-polyamide resin, nitrocellulose melamine resin, mixture of high molecular weight polyester resin and isocyanate prepolymer, urea formaldehyde resin, low molecular weight glycol / High molecular weight diol / polyisocyanate mixtures, polyamine resins, and mixtures thereof.

Further, among the binders constituting the magnetic recording layer, cellulose esters having a substitution degree of 1.7 to 2.9 are preferably used. Particularly preferred are cellulose diacetate, cellulose acetate butyrate, and cellulose acetate propionate.

In the binders listed above, polar groups (epoxy group, CO ₂ M, OH, NR ₂ , NR ₃ X, SO ₃
M, OSO ₃ M, PO ₃ M ₂ , OPO ₃ M ₂ , where M
Is hydrogen, an alkali metal or ammonium, and when there are a plurality of M in one group, they may be different from each other, and R is hydrogen or an alkyl group).

The above binders are used alone or in a mixture of several kinds, and may contain an epoxy-based, aziridine-based, or isocyanate-based crosslinking agent. By using a cross-linking agent, the adhesion between layers can be enhanced. The isocyanate-based crosslinking agent is a polyisocyanate compound having two or more isocyanate groups, such as tolylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluidine diisocyanate, isophorone diisocyanate, and triphenylmethane. Isocyanates such as diisocyanates, and reaction products of these isocyanates with polyalcohols (for example, 3 mol of tolylene diisocyanate and 1 mol of trimethylolpropane
1) and polyisocyanates formed by condensation of these isocyanates. Particularly preferred among the above crosslinking agents are isocyanate-based crosslinking agents represented by the following general formula (1). General formula (1):

[0026]

Embedded image

N is preferably in the range of 0 to 50, more preferably 0 to 30, and still more preferably 0 to 10.
The number n does not need to be single and may have a distribution. m is an integer of 1-2. R ₁ , R ₂ , and R ₃ represent H, an alkyl group (C ₁ or more), or an aryl group (C
₆ or more). The preferred viscosity of such a crosslinking agent is 50
(CP / 25 ° C.) to 1000 (cP / 25 ° C.).
The preferred NCO content of such a crosslinking agent is 20 to
40%. More preferably, it is 25 to 35%. Commercial products of such a crosslinking agent include “Millionate MT” and “Millionate MR” manufactured by Nippon Polyurethane Co., Ltd.
-100 "," Millionate MR-200 "," Millionate MR-300 "," Millionate MR-40 "
0 "and" Sumijur 44V10 "(all of which are trade names) manufactured by Sumitomo Bayer Urethane Co., Ltd. The coating amount of the crosslinking agent is 3 mg / m ² or more and 1000
mg / m ² or less, more preferably 5 mg / m ² or more and 500 mg / m ² or less,
More preferably, it is 10 mg / m ² or more and 300 mg / m ^2.
It is as follows. In order for such a cross-linking agent to sufficiently perform cross-linking, at 50 ° C. or more, preferably 70 ° C. or more, for 1 minute to 72 ° C.
It is preferable to heat and dry for a long time.

When using the crosslinking agent used in the present invention,
By simultaneously using at least one or more of tertiary amine, metal salt, and DBU (1,8-diaza-bicyclo [5,4,0] undecene-7) compounds, the magnetic recording layer itself can be used. Alternatively, the rate of the crosslinking reaction between the magnetic recording layer and the base / magnetic recording layer can be accelerated, and the time of the crosslinking reaction for improving the durability can be shortened. For tertiary amines, for example, Bruins et al.
ane Technology "P.25, Interscience (1960), such as tetramethylbutanediamine and 1,4-
Examples include diazabicyclo [2,2,2] octane and triethylamine. In the case of metal salts, for example, dibutyltin dilaurate, tin octoate, cobalt naphthenate, stannous chloride, tetra-n-butyltin, stannic chloride, trimethyltin hydroxide, dimethyl 2
Tin chloride and the like. Such a compound is, for example, added to the coating solution of the magnetic recording layer or a layer adjacent thereto together with the crosslinking agent of the present invention, and then coated, or / and the coating solution of the lower layer or / and the upper layer of the above layer Alternatively, the compound may be added to the layer to utilize the diffusion of the compound into the layer for improving the durability.

The film support used in the present invention includes triacetyl cellulose (TAC), polyamide, polycarbonate, polyester and the like, with polyester being preferred. The preferred average molecular weight range for these polyesters is from about 5,000 to 200,000. The polyester used in the present invention has a Tg of 70 to 200 ° C, preferably 90 to 180 ° C. Specifically, the following compound examples can be shown.

P-1: [terephthalic acid (TPA) / ethylene glycol (EG)) (100/100)] (PET) Tg = 80 ° C. P-2: [2,6-naphthalenedicarboxylic acid (NDCA) / ethylene Glycol (EG) (100/100)] (PEN) Tg = 119 ° C P-3: 2,6-NDCA / TPA / EG (50/50/100) Tg = 92 ° C P-4: PEN / PET ( 60/40) Tg = 95 ° C P-5: PEN / PET (80/20) Tg = 104 ° C

Preferred among the polyesters is 2,6-
A polyester containing naphthalenedicarboxylic acid, wherein 2,6-naphthalenedicarboxylic acid is included in all dicarboxylic acids.
It is a polyester containing 0 mol% or more. Among them, polyethylene-2,6-naphthalenedicarboxylate is particularly preferred. The thickness of the support is 80 to 115 μm.
And particularly preferably from 85 to 105 μm.
Further, the polyester support is heated to 40 ° C. before coating the photosensitive layer.
When the heat treatment is performed at a temperature equal to or lower than the glass transition temperature for 0.1 to 1500 hours, it is possible to make the roll-shaped photosensitive material hard to curl.

For the TAC support, a plasticizer such as triphenyl phosphate, biphenyl diphenyl phosphate, dimethyl ethyl phosphate or the like is usually added. The support may contain a dye for the purpose of neutralizing the base color, preventing light piping, preventing halation, and the like. In order to firmly adhere a photographic layer (for example, a photosensitive silver halide emulsion layer, an intermediate layer, a filter layer, a magnetic recording layer, and a conductive layer) on these supports, a chemical treatment,
Mechanical treatment, corona discharge treatment, flame treatment, UV treatment,
After performing a surface activation treatment such as a high-frequency treatment, a glow discharge treatment, an active plasma treatment, a laser treatment, a mixed acid treatment, and an ozone oxidation treatment, a photographic emulsion may be directly applied to obtain an adhesive force, or the surface of these may be temporarily treated. After the treatment or without the surface treatment, an undercoat layer may be provided, and a photographic emulsion layer may be coated thereon.

In the back layer of the present invention,
It can contain dyes, surfactants and the like. As the slipping agent used for the back layer, for example, a higher fatty acid ester (an ester of a fatty acid having 10 to 24 carbon atoms and an alcohol having 10 to 60 carbon atoms) is preferable. The use amount of the slip agent is preferably 0.001 to 0.1 g / m ² , and more preferably 0.005 to 0.05 g / m ² .

The magnetic recording material of the present invention may contain a polymer latex in the constituent layers. In the case of a photosensitive material, in order to improve poor adhesion under high temperature and high humidity, it is preferable to provide irregularities on the surface, and a rough surface is more preferable.

The preferred projections are within the range having the average height of the projections of the present invention. For example, when the projections are formed with a spherical or irregular matting agent, the content is 0.5 to 600.
a mg / m ^2, and more preferred is 1 to 400 mg / m ^2. At this time, the matting agent to be used is not particularly limited in its composition, and may be an inorganic or organic substance, or a mixture of two or more kinds. The particles used in the present invention may be particles remaining in the light-sensitive material even after the development processing, but may be dissolved in a processing solution, and in such a case, it is desirable to include a group which is alkaline and soluble.

The inorganic compound and the organic compound of the matting agent of the present invention include, for example, fine powders of inorganic substances such as barium sulfate, manganese colloid, titanium dioxide, strontium barium sulfate, and silicon dioxide. Examples thereof include silicon dioxide such as synthetic silica obtained by gelling an acid, and titanium dioxide (rutile type or anatase type) generated by titanium slug and sulfuric acid. It can also be obtained by pulverizing an inorganic substance having a relatively large particle size, for example, 20 μm or more, and then performing classification (vibration filtration, wind classification, etc.). Other examples include pulverized and classified organic polymer compounds such as polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethylene carbonate, and starch. Alternatively, a polymer compound synthesized by a suspension polymerization method, a spherical polymer compound by a spray drying method, a dispersion method, or the like, or an inorganic compound can be used.

In addition, one of the monomer compounds described below
A polymer compound of a kind or two or more kinds of polymers may be formed into particles by various means. The polymer may be formed from a single monomer, or may be used as particles of a copolymer obtained by polymerizing a plurality of monomers. Among the monomer compounds, acrylates, methacrylates, vinyl esters, styrenes, and olefins are preferably used. Also, the present invention relates to JP-A-62-14647 and JP-A-62-17744.
And particles having a fluorine atom or a silicon atom as described in JP-A-62-17743.

Among these, the particle compositions preferably used are polystyrene, polymethyl (meth) acrylate, polyethyl acrylate, poly (methyl methacrylate / methacrylic acid = 95/5, or 50/50 (molar ratio), poly (styrene / Styrenesulfonic acid = 95 /
5, or 60/40 (molar ratio), polyacrylonitrile, poly (methyl methacrylate / ethyl acrylate / methacrylic acid = 50/40/10), silica and the like. These matting agents preferably have an average particle size of 0.01 to 25 μm,
0.1-20 μm is more preferred. The layer containing the matting agent is not particularly limited, but is preferably an emulsion protective layer, a back layer, and a back protective layer. Among them, the emulsion and the back protective layer are preferred, and the thickness of the protective layer is 0.05 to 6 μm, more preferably 0.15 to 5 μm.

Particularly preferred examples of the magnetic recording medium of the present invention include a color reversal film and a color negative film including a silver halide photosensitive layer. In particular, general-purpose color negative films are preferable. As the silver halide emulsion, usually, those subjected to physical ripening, chemical ripening and spectral sensitization are used. The effect of the present invention is particularly noticeable when an emulsion sensitized with a gold compound and a sulfur-containing compound is used. Additives used in such a process are Research Disclosure Nos. 17643 and 18
716, and the relevant portions are described later.

Known photographic additives which can be used in the present invention are also described in the above two Research Disclosures, and the relevant portions are shown in the following table. Additive type RD17643 RD18716 1 Chemical sensitizer page 23, page 648, right column 2 Sensitivity enhancer Same as above 3 Spectral sensitizer, page 23-24, page 648 right column-supersensitizer 649, right column 4 Brightening agent 24 Page 5 Antifoggant 24 to 25 page 649 right column and stabilizer 6 Light absorber, page 649 right column Filter dye, 25 to 26 page 650 page left column Ultraviolet absorber 7 Stain inhibitor 25 page right column 650 Page left to right column 8 Dye image stabilizer page 25 9 Hardening agent page 26 651 page left column 10 Binder page 26 Same as above 11 Plasticizer, lubricant 27 page 650 page left column 12 Coating aid, pages 26 to 27 650 Right column Surfactant

In the present invention, APS (Advanced Ph) is used.
In the case of a patrone with a built-in color sensitive material, the total weight of the plastic used for the patrone and the patrone case is usually 1 g or more and 25 g or less,
Preferably it is 5 g or more and 15 g or less. For APS,
Since the roll width of the film is 24 mm, the size of the patrone can be reduced. The patrone of the present invention is not particularly limited in its form. The stored photographic film may be a so-called raw film before development or a photographic film that has been subjected to development processing. Also, the raw film and the developed photographic film may be stored in the same new patrone,
Another patrone may be used.

[0042]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 (Preparation of sample 1-A) 1) First layer A UV-irradiation (UV) treatment was applied to both sides of a polyethylene naphthalate support having a thickness of 90 μm, and then the following composition was adhered to the back side. Layers were provided. In addition, the application amount was 10.4 cc /
It was m ^2. Irradiation with ultraviolet rays was carried out by the method as shown in Examples of JP-B-45-3828. Gelatin 0.9 parts by weight Distilled water 0.9 parts by weight Acetic acid 0.9 parts by weight Methanol 46.7 parts by weight Ethylene dichloride 46.7 parts by weight p-chlorophenol 3.7 parts by weight

2) Second layer 230 parts by weight of stannic chloride hydrate and antimony trichloride 2
3 parts by weight were dissolved in 3000 parts by weight of ethanol to obtain a homogeneous solution. To this solution, a 1N aqueous solution of sodium hydroxide was added dropwise until the solution reached pH 3 to obtain a coprecipitate of colloidal stannic oxide and antimony oxide. The obtained coprecipitate was left at 50 ° C. for 24 hours to obtain a red-brown colloidal precipitate. The reddish brown colloidal precipitate was separated by centrifugation.
Water was added to the precipitate to remove excess ions, and the precipitate was washed with water by centrifugation. This operation was repeated three times to remove excess ions. 200 parts by weight of the colloidal precipitate from which excess ions had been removed were redispersed in 1500 parts by weight of water and sprayed into a baking furnace heated to 500 ° C. to give a bluish average particle size of 0.005 μm.
Of stannic oxide / antimony oxide composite oxide was obtained. The resistivity of the fine particle powder was 25 Ω · cm. A mixture of 40 parts by weight of the fine powder and 60 parts by weight of water was adjusted to pH 7.0.
After coarse dispersion with a stirrer, the residence time is 30 in a horizontal sand mill (Dynomill, manufactured by Willy A. Backfen AG).
To prepare a dispersion in which the primary particles partially aggregate to 0.05 μm as secondary aggregates.

A solution having the following formulation was applied so as to have a dry film thickness of 0.3 μm, and dried at 110 ° C. for 30 seconds. 10 parts by weight of the conductive fine particle dispersion (SnO ₂ / Sb ₂ O ₃ composite oxide, 0.15 μm) 1 part by weight of gelatin 27 parts by weight of water 60 parts by weight of methanol 2 parts by weight of resorcinol polyoxyethylene Nonyl phenyl ether (degree of polymerization 10) 0.01 parts by weight

3) Third layer Co-coated γ-Fe ₂ O ₃ magnetic material (Hc: 831 Oe, σs: 7)
7.1 emu / g, σr: 37.4 emu / g, SBET
: 38.7 m ² / g) 1100 parts by weight, water 220 parts by weight and a silane coupling agent [3- (poly (polymerization degree 1
0) Oxyethynyl) oxypropyl trimethoxysilane] 165 parts by weight, and add 3 with an open kneader.
Kneaded well for a good time. This roughly dispersed viscous liquid is
After drying at ℃ for 24 hours to remove water, the coating was heated at 110 ° C. for 1 hour to carry out treatment to produce surface-treated magnetic particles.

Further, the mixture was kneaded again with an open kneader for 4 hours according to the following formulation. The above-mentioned surface-treated magnetic particles 855 g Diacetyl cellulose 25.3 g Methyl ethyl ketone 136.3 g Cyclohexanone 136.3 g

Further, a sand mill (1/1 /
(4G sand mill) at 2,000 rpm for 4 hours. As the medium, glass beads having a diameter of 1 mm were used. The above kneading liquid 45 g Diacetyl cellulose 23.7 g Methyl ethyl ketone 127.7 g Cyclohexanone 127.7 g

Further, a third layer coating solution was prepared according to the following formulation. Preparation of Intermediate Solution Containing Magnetic Material 48.4 g of the above fine dispersion liquid 1917.1 g (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) These were stirred and mixed with a disper, A magnetic substance-containing intermediate liquid "was produced.

Preparation of Particle Dispersion A sand mill (1/4 G sand mill in which the inside of the vessel and the rotating disk are ceramic-coated) has the following formulation.
At 2000 rpm for 5 hours. As the media, zirconia beads having a diameter of 1 mm were used. AKP50 37 g (α-alumina, manufactured by Sumitomo Chemical Co., Ltd., average primary particle diameter 0.19 μm) Silane coupling agent 2.6 g [3- (poly (degree of polymerization 10) oxyethynyl) oxypropyl trimethoxysilane] diacetylcellulose solution 330 0.4 g (solid content 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1)

Preparation of Third Layer Coating Solution The above magnetic substance-containing intermediate solution 3500 g Diacetyl cellulose solution 198 g (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) AKP50 particle dispersion 89 g Crosslinking agent [1]: Millionate MR-400 15.8 g (manufactured by Nippon Polyurethane Co., Ltd.) Methyl ethyl ketone 31 g Cyclohexanone 31 g

This coating solution was applied with a wire bar to a coating amount of 2
Coating was performed so as to be 9.3 cc / m ² . 110 for drying
C. was performed. AKP50 was coated with 60 mg / m ^2.

4) Fourth Layer Preparation of Dispersion Solution of Slip Agent The following solution a was heated and dissolved at 90 ° C., added to solution b, and dispersed with a high-pressure homogenizer to prepare a stock solution of a slip agent. a liquid compound 0.75 part by weight of _{C 6 H 13 CH (OH)} (CH 2) 10 COOC 40 H 61 compound 0.75 part by weight of _{n-C 50 H 101 O (} CH 2 CH 2 O) 16 H Xylene 2. 11 parts by weight Propylene glycol-monomethyl ether 0.08 parts by weight Solution b Cyclohexanone 96.3 parts by weight Preparation of coating solution for fourth layer The following binder and solvent were added to 482 g of the above-mentioned slip dispersion stock solution to prepare a coating solution. Hydroxypropylcellulose 0.96 g (Nippon Soda Co., Ltd., trade name HPC-SL) Isopropyl alcohol 3243 g Methanol 114.55 g Cyclohexanone 144 g Compound 0.73 g C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) (CH ₂ CH) _{2 O) 4 (CH 2)} 4 SO 3 Na polyester modified silicone solution 2.88 g (BYK chemi Japan Co., Ltd., trade name BYK310, 25% solids content)

The above sliding layer coating solution was applied at a coating amount of 10.4 cc / m ² . Drying was performed at 110 ° C.

Next, the evaluation of the sample will be described.

A) Measurement of Haze A haze meter “VGS-1001D” manufactured by Nippon Denshoku Industries Co., Ltd.
The degree of haze was measured using "P". At this time, the measurement was performed so that light was incident from the back layer side. The haze of the medium is 9
% Or less, and 9% or more of the samples were judged as x (NG). The haze degree is defined as follows.

T = D + PT PT: Parallel transmittance H = (D / T) × 100 (%) T: Total transmittance D: Diffusion H: Haze (turbidity)

B) Surface Roughness Measurement The surface roughness (Rq) was measured under the following conditions using a contact type three-dimensional surface roughness meter “Surfcom 570A-3DF” manufactured by Tokyo Seimitsu Co., Ltd. Scan speed: 0.15 mm / sec Cut-off value: 0.25 mm Measurement area: 1 mm × 0.5 mm Needle: 90 ° 2 μmR Diamond needle

C) Evaluation of Number of Surface Protrusions Scanning electron microscope "ESM-3200" (ELIONI)
X (manufactured by X Corporation).
The photograph was taken at a magnification of × 1 to × 10000, and the number of surface protrusions per 100 μm ² was determined while distinguishing the particles from magnetic particles.

D) Measurement of the particle size of the particles dispersed in the coating layer In order to determine the particle size (average secondary particle size) of the particles dispersed in the coating layer of the prepared sample, the following procedure was performed. . The binder covering the particles is removed using a low-temperature incinerator (plasma reactor PR-503, manufactured by Yamato Scientific Co., Ltd.). The surface of the sample after removing the binder covering the surface of the particles is photographed with a scanning electron microscope “ESM-3200” at a magnification of 5,000 to 10,000. Using a digitizer, the equivalent circle diameter was determined for each particle in the photograph. The circle equivalent diameter is referred to as "particle size of particles dispersed in the coating layer".
And

E) Evaluation of magnetic input / output performance A prepared sample slit to a width of 24 mm and a length of 200 m was
At a conveying speed of 100 mm / sec, a 6 kHz FM
Magnetic recording with signal, gap 5μm, number of turns 2000
The recording signal was reproduced by a turn general-purpose magnetic reproducing head using an amplifier having a gain of about 95 dB, each of the reproduced signals was examined as follows, and the magnetic input / output performance was evaluated. A medium in which dirt present on the medium back surface is transferred to the surface of the magnetic head was employed because the signal amplitude was reduced due to space loss and the number of dropouts increased. When the magnitude of each reproduction signal becomes 35% or less of the average magnitude of the ideal reproduction signal when the magnetic head is free from dirt, it is defined as "dropout", and the number of dropouts is 10 times. × (NG) Dropout is 5 times or more and less than 10 times △ (NG) Dropout is 3 times or more and less than 5 times ○ Dropout is 1 time or more and less than 3 times Time ○○ When there is no dropout, it was judged as ○○○.

(Preparation of Samples 1-B to D and Comparative Samples 1-E to G) Except for changing the coating amount of alumina AKP50 contained in the back third layer of Sample 1-A as shown in Table 1,
It was produced in exactly the same way as Sample 1-A. This is called Sample 1
B to D and Comparative Samples 1 to EG.

[0063]

[Table 1]

As can be seen from Table 1, in order to achieve a reliable magnetic input / output property, even if Rq exceeds 30 nm, the number of surface projections must not be less than 30/100 μm ² .

(Preparation of Comparative Sample 1-H) Sample 1-A was prepared in exactly the same manner as Sample 1-A except that one layer was provided between the third back layer and the fourth back layer according to the following formulation. . This is designated as Comparative Sample 1-H. Diacetyl cellulose 4 g Methyl ethyl ketone 498 g Cyclohexanone 498 g This was applied at a coating amount of 10.4 cc / m ² .

As can be seen from the results shown in Table 1, even when the number of surface protrusions exceeds 30/100 μm ² , it is understood that if Rq is less than 5 nm, the magnetic input / output performance deteriorates.

(Samples 1-I, M, L Comparative samples 1-J,
Preparation of K) Sample 1-A was prepared in exactly the same manner as Sample 1-A except that the formulation of the back third layer was changed as follows. Samples 1-I, M, L Comparative samples 1-J, K
And

Third layer Co-coated γ-Fe ₂ O ₃ magnetic material (Hc: 831 Oe, σs: 7)
7.1 emu / g, σr: 37.4 emu / g, SBET
: 38.7 m ² / g) 1100 parts by weight, water 220 parts by weight and a silane coupling agent [3- (poly (polymerization degree 1
0) Oxyethynyl) oxypropyl trimethoxysilane] 165 parts by weight, and add 3 with an open kneader.
Kneaded well for a good time. This roughly dispersed viscous liquid is
After drying at ℃ for 24 hours to remove water, the coating was heated at 110 ° C. for 1 hour to carry out treatment to produce surface-treated magnetic particles.

Further, the mixture was kneaded again in the open kneader for 4 hours according to the following formulation. The above-mentioned surface-treated magnetic particles 855 g Diacetyl cellulose 25.3 g Methyl ethyl ketone 136.3 g Cyclohexanone 136.3 g

Further, a sand mill (1/1 /
(4G sand mill) at 2,000 rpm for 4 hours. As the medium, glass beads having a diameter of 1 mm were used. The above kneading liquid 45 g Diacetyl cellulose 23.7 g Methyl ethyl ketone 127.7 g Cyclohexanone 127.7 g

Further, a third layer coating solution was prepared according to the following formulation. Preparation of Intermediate Solution Containing Magnetic Material 48.4 g of the above fine dispersion liquid 1917.1 g (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) These were stirred and mixed with a disper, A magnetic substance-containing intermediate liquid "was produced.

Preparation of Particle Dispersion Under the following formulation, while cooling with ice using an ultrasonic disperser, 5
Fine dispersion was performed at 0 Hz for 30 minutes. Sample 1-I 0.3 μm silica: 10 g of sea hoster KEP30 (Comparative sample 1-J 0.5 μm silica: 10 g of sea hoster KEP50) (Comparative sample 1-K 1.0 μm silica: 10 g of sea hoster KEP100 10 g) (Sample 1-L 0.2 μm (Melamine resin: Eposta S 10 g) <All manufactured by Nippon Shokubai Co., Ltd.> (Sample 1-M 0.3 μm siloxane resin: Tospearl 103 10 g) <Made by Toshiba Silicone Co., Ltd.>

The following are added to the above powder: 90 g of diacetyl cellulose solution (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1)

Preparation of Third Layer Coating Solution The above magnetic substance-containing intermediate solution 3500 g Diacetyl cellulose solution 198 g (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) The above silica fine dispersion sample 1-I 44.5 g (44.5 g for Comparative Sample 1-J) (3.0 g for Comparative Sample 1-K) (44.5 g for Sample 1-L) (44.5 g for Sample 1-M) Crosslinking Agent [1]: Millionate MR-400 15.8 g (manufactured by Nippon Polyurethane Co., Ltd.) Methyl ethyl ketone 31 g Cyclohexanone 31 g

This coating solution was applied with a wire bar at a coating amount of 2
Coating was performed so as to be 9.3 cc / m ² . 110 for drying
C. was performed.

As can be seen from the results in Table 1, similar results were obtained using inorganic or organic particles other than AKP50.

Example 2 (Preparation of Sample 2-A) Sample 1-A was prepared in exactly the same manner as Sample 1-A except that the formulation of the third layer was changed as follows. This is designated as Sample 2-A. Third layer Co-coated γ-Fe ₂ O ₃ magnetic material (Hc: 831 Oe, σs: 7)
7.1 emu / g, σr: 37.4 emu / g, SBET
: 38.7 m ² / g) 1100 parts by weight, water 220 parts by weight and a silane coupling agent [3- (poly (polymerization degree 1
0) Oxyethynyl) oxypropyl trimethoxysilane] 165 parts by weight, and add 3 with an open kneader.
Kneaded well for a good time. This roughly dispersed viscous liquid is
After drying at ℃ for 24 hours to remove water, the coating was heated at 110 ° C. for 1 hour to carry out treatment to produce surface-treated magnetic particles.

Further, the mixture was kneaded again in an open kneader for 4 hours according to the following formulation. The above-mentioned surface-treated magnetic particles 855 g Diacetyl cellulose 25.3 g Methyl ethyl ketone 136.3 g Cyclohexanone 136.3 g

Furthermore, a sand mill (1/1 /
(4G sand mill) at 2,000 rpm for 4 hours. As the medium, glass beads having a diameter of 1 mm were used. The above kneading liquid 45 g Diacetyl cellulose 23.7 g Methyl ethyl ketone 127.7 g Cyclohexanone 127.7 g

Further, a coating solution for the third layer was prepared according to the following formulation. Preparation of Intermediate Solution Containing Magnetic Material 48.4 g of the above fine dispersion liquid 1917.1 g (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) These were stirred and mixed with a disper, A magnetic substance-containing intermediate liquid "was produced. Preparation of Particle Dispersion A sand mill (1/4 G sand mill in which the inside of the vessel and the rotating disk are ceramic-coated) with the following formulation
At 2000 rpm for 5 hours. As the media, zirconia beads having a diameter of 1 mm were used. HIT100 37 g (α-alumina, manufactured by Sumitomo Chemical Co., Ltd., average primary particle diameter 0.10 μm) Silane coupling agent 8.4 g [3- (poly (degree of polymerization 10) oxyethynyl) oxypropyl trimethoxysilane] diacetyl cellulose solution 324 0.6 g (solid content 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) Preparation of back third layer coating solution 3500 g of magnetic substance-containing intermediate solution 287 g of HIT100 fine dispersion 287 g Crosslinking agent [1]: Millionate MR-400 15.8 g (manufactured by Nippon Polyurethane Co., Ltd.) Methyl ethyl ketone 31 g Cyclohexanone 31 g

This coating solution was applied with a wire bar at a coating amount of 2
Coating was performed so as to be 9.3 cc / m ² . 110 for drying
C. was performed.

[0082]

[Table 2]

As can be seen from the results in Table 2, even when HIT100, which is α-alumina having an average particle diameter of 0.2 μm or less, a magnetic recording medium having good magnetic input / output properties was obtained.

Example 3 (Preparation of Sample 3-A) The sample of Example 1-A was prepared in exactly the same manner as Sample 1-A except that the dispersion time of alumina AKP50 was extended from 5 hours to 10 hours. This is designated as Sample 3-A. The sample 1-A and the sample 3-A were measured for the particle diameter of AKP50 particles dispersed in the coating layer.
Below, whereas Sample 3-A contained 0.7 μm
m or less particles were contained at 95% or more. As can be seen from the results in Table 2, when the coating layer contains 95% or more of particles of 0.7 μm or less, the magnetic input / output characteristics are further improved.

Example 4 (Preparation of Samples 4-A, B, C, D, and E) In Sample 1-A, except that the formulation of the third layer was changed as follows:
It was produced in exactly the same way as. This is referred to as Samples 4-A, B,
C, D, and E. Third layer Co-coated γ-Fe ₂ O ₃ magnetic material (Hc: 831 Oe, σs: 7)
7.1 emu / g, σr: 37.4 emu / g, SBET
: 38.7 m ² / g) 1100 parts by weight, water 220 parts by weight and a silane coupling agent [3- (poly (polymerization degree 1
0) Oxyethynyl) oxypropyl trimethoxysilane] 165 parts by weight, and add 3 with an open kneader.
Kneaded well for a good time. This roughly dispersed viscous liquid is
After drying at ℃ for 24 hours to remove water, the coating was heated at 110 ° C. for 1 hour to carry out treatment to produce surface-treated magnetic particles.

Further, the mixture was kneaded again with an open kneader for 4 hours according to the following formulation. The above-mentioned surface-treated magnetic particles 855 g Diacetyl cellulose 25.3 g Methyl ethyl ketone 136.3 g Cyclohexanone 136.3 g

Further, a sand mill (1/1 /
(4G sand mill) at 2,000 rpm for 4 hours. As the medium, glass beads having a diameter of 1 mm were used. The above kneading liquid 45 g Diacetyl cellulose 23.7 g Methyl ethyl ketone 127.7 g Cyclohexanone 127.7 g

Further, a third layer coating solution was prepared according to the following formulation. Preparation of Intermediate Solution Containing Magnetic Material 48.4 g of the above fine dispersion liquid 1917.1 g (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) These were stirred and mixed with a disper, A magnetic substance-containing intermediate liquid "was produced.

Preparation of Particle Dispersion (1) Preparation of Particle 1 Dispersion A sand mill (1/4 G sand mill in which the inside of a vessel and a rotating disk are ceramic-coated) is prepared according to the following formulation.
At 2000 rpm for 5 hours. As the media, zirconia beads having a diameter of 1 mm were used. AKP50 37 g (α-alumina, manufactured by Sumitomo Chemical Co., Ltd., average primary particle diameter 0.10 μm) Silane coupling agent 2.6 g [3- (poly (degree of polymerization 10) oxyethynyl) oxypropyl trimethoxysilane] diacetyl cellulose solution 330 0.4 g (solid content 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1)

(2) Preparation of Particle 2 Dispersion Part 1 Under the following formulation, while cooling on ice with an ultrasonic disperser,
Fine dispersion was performed at 0 Hz for 30 minutes. Sample 4-A 0.1 μm silica: Seahosta KEP10 10 g Nippon Shokubai Co., Ltd. (Sample 4-B 0.14 μm calcium carbonate: Homocal D 10 g Shiraishi Kogyo Co., Ltd.) Add the following to the above powder 90 g diacetyl cellulose solution (Solid content 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) Part 2 A particle dispersion was prepared according to the following formulation.

Sample 4-D The HIT100 (0.10 μm) dispersion used for Sample 2-A was used. Preparation of Third Layer Coating Liquid (Preparation of Sample 4-A) Above-mentioned magnetic substance-containing intermediate liquid 3500 g Diacetyl cellulose solution 109 g (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) AKP50 particle dispersion liquid 89 g Seahoster KEP10 dispersion 89 g Crosslinking agent [1]: Millionate MR-400 15.8 g (manufactured by Nippon Polyurethane Co., Ltd.) Methyl ethyl ketone 31 g Cyclohexanone 31 g

This coating solution was applied with a wire bar at a coating amount of 2
Coating was performed so as to be 9.3 cc / m ² . 110 for drying
C. was performed.

(Preparation of Sample 4-B) 3500 g of the above magnetic substance-containing intermediate solution 109 g of diacetyl cellulose solution (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) AKP50 particle dispersion 89 g Homocal D dispersion 89 g Crosslinking agent [1]: Millionate MR-400 15.8 g (manufactured by Nippon Polyurethane Co., Ltd.) Methyl ethyl ketone 31 g Cyclohexanone 31 g

This coating solution was applied with a wire bar at a coating amount of 2
Coating was performed so as to be 9.3 cc / m ² . 110 for drying
C. was performed.

(Preparation of Sample 4-C) The above-mentioned magnetic substance-containing intermediate liquid 3500 g Diacetyl cellulose solution 99 g (solid content: 4.5%, solvent: methyl ethyl ketone / cyclohexanone = 1/1) AKP50 particle dispersion 89 g MIBK silica sol dispersion ( 0.015 μm Silica sol Solid content 30% Nissan Chemical Co., Ltd. 99 g Crosslinking agent [1]: Millionate MR-400 15.8 g (Nippon Polyurethane Co., Ltd.) Methyl ethyl ketone 31 g Cyclohexanone 31 g

This coating solution was applied with a wire bar at a coating amount of 2
Coating was performed so as to be 9.3 cc / m ² . 110 for drying
C. was performed.

(Preparation of Sample 4-D) The above-mentioned magnetic substance-containing intermediate liquid 3500 g AKP50 particle dispersion liquid 89 g HIT100 dispersion liquid 198 g Crosslinking agent [1]: Millionate MR-400 15.8 g (manufactured by Nippon Polyurethane Industries, Ltd.) Methyl ethyl ketone 31 g Cyclohexanone 31g

This coating solution was applied with a wire bar at an amount of 2
Coating was performed so as to be 9.3 cc / m ² . 110 for drying
C. was performed.

(Preparation of Sample 4-E) 3500 g of the above magnetic substance-containing intermediate liquid Sample 1-I particle dispersion (as particle 1; Seahosta KEP30 10% fine dispersion) 89 g Sample 2-A particle dispersion (as particle 2) HIT100 10% fine dispersion 198 g Crosslinking agent [1]: Millionate MR-400 15.8 g (manufactured by Nippon Polyurethane Co., Ltd.) Methyl ethyl ketone 31 g Cyclohexanone 31 g

This coating solution was applied with a wire bar at a coating amount of 2
Coating was performed so as to be 9.3 cc / m ² . 110 for drying
C. was performed.

As can be seen from the results in Table 2, the inorganic particles
More than one kind, when the average primary particle diameter of at least one particle is 0.2 to 0.4 μm or less and the average primary particle diameter of at least one particle is 0.15 μm or less, more favorable magnetic input / output characteristics Can be produced.

Example 5 The following sample 5-A was prepared in the same manner as in sample 1-A.

With respect to a polyethylene naphthalate support having a thickness of 90 μm, a processing atmosphere pressure of 0.2 Torr, a partial pressure of H ₂ O in an atmosphere gas of 75%, a discharge frequency of 30 kHz, an output of 2500 W and a processing strength of 0. 5
Glow discharge treatment was performed at kV · A · min / m ² . On this support, the first layer was not provided, and as a second layer, a coating solution having the following composition was applied at a coating amount of 5 cc / m ² by using a bar coating method described in Japanese Patent Publication No. 58-4589.

Conductive Fine Particle Dispersion (SnO ₂ / Sb ₂ O ₅ Particle Concentration 50 Parts by Weight 10% Aqueous Dispersion. Secondary Aggregate with Primary Particle Diameter of 0.005 μm and Average Particle Diameter of 0.05 μm) Gelatin 0.5 parts by weight Water 49 parts by weight Polyglycerol polyglycidyl ether 0.16 parts by weight Poly (degree of polymerization 20) oxyethylene 0.1 parts by weight Sorbitan monolaurate

Further, after coating the second layer of the back,
cm stainless steel core, 110 ℃ (PEN
(Tg of the support: 119 ° C.), and heat-treated for 48 hours to make a thermal history. Then, the support was sandwiched, and a coating solution of the following composition was formed as an undercoat layer on the side opposite to the back layer side by a bar coating method.
Coating was performed at a coating amount of cc / m ² .

Gelatin 1.01 part by weight Salicylic acid 0.30 part by weight Resorcin 0.40 part by weight Poly (degree of polymerization 10) oxyethylene nonylphenyl ether 0.11 part by weight Water 3.53 parts by weight Methanol 84.57 parts by weight n -Propanol 10.08 parts by weight Further, similarly to Sample 1-A, the third and fourth layers are coated on the second layer side, and then the photosensitive layers described below are coated, and silver halide is coated. A magnetic recording medium with an emulsion layer was produced.

(Coating of photosensitive layer) JP-A-7-287345
No. 5-A, which is a multilayer color negative photosensitive material described in Example 1 of the publication, was prepared. Further, the following development processing was performed on Sample 5-A before reading the magnetic signal. (Development processing of photographic film)
Development processing was performed according to the CN-16X chemical prescription of Fuji Photo Film. As a developing machine, a cine-type automatic developing machine FNCP-900 manufactured by Fuji Photo Film Co., Ltd. was used.

The magnetic output performance of Sample 5-A after the development was as excellent as Sample 1-A and Sample 5-A before the development. In addition, when the above-mentioned Example sample and Comparative example sample were examined in the same manner as Sample 5-A (coating and developing of the emulsion layer), the same results were obtained for the magnetic input / output performance. Obtained.

Example 6 (Preparation of Sample 6-A) In Sample 5-A, the emulsion layer was
In the same manner as in the case of sample 101 of Example 1 as a reversal color emulsion layer in JP-A-2-854 Example 1,
854 Except for performing the development process for a color reversal photosensitive material as shown in Example 1, the same procedure as in the preparation of sample 5-A was carried out, and the same result as that of sample 5-A was obtained. As a result, a magnetic recording medium having a silver halide emulsion layer was obtained, which was compatible with both properties and magnetic input / output properties.

Example 7 (Preparation of Samples 7-A and B) The solvent of the back third layer of Sample 1-A was changed from MEK (50%) cyclohexanone (50%) to MEK (50%) cyclohexanone (10%). Samples only changed to acetone (40%) were sample 7-A, M
A sample obtained by changing only EK (50%) cyclohexanone (10%) and methyl acetate (40%) is referred to as a sample 7-B.
Both Samples 7-A and 7-B were no different from Sample 1-A in terms of performance, and on the other hand, the drying speed was faster, so that the coating speed could be increased, and thus the production cost could be reduced, and thus it was a preferable sample. . Note that the samples prepared in Examples 1 to 7 are all transparent.

[0111]

According to the present invention, it is possible to provide a transparent magnetic recording medium having a durable magnetic recording layer having both reliable magnetic input / output performance and transparency even when used repeatedly.

Claims (8)

[Claims] 1. A magnetic recording medium having a magnetic recording layer containing at least one magnetic particle on a support, wherein at least one layer on the magnetic recording layer side contains inorganic particles and / or organic resin particles, The surface roughness of the magnetic recording layer is 5n at Rq
m or more and 30 nm or less and 10% of the magnetic recording layer.
A transparent magnetic recording medium characterized in that the number of surface projections made of particles other than magnetic particles per 0 μm ² is 30 or more, and the haze degree is less than 9%. 2. The transparent magnetic recording medium according to claim 1, wherein the transparent magnetic recording layer and / or the layer adjacent to the transparent magnetic recording layer contains inorganic particles and / or organic polymer particles. . 3. The method according to claim 1, wherein at least one of the inorganic particles comprises:
3. The transparent magnetic recording medium according to claim 1, wherein the medium is α-alumina having an average primary particle diameter of 0.4 μm or less. 4. Inorganic particles having different average primary particle diameters and / or
And two or more kinds of organic polymer particles, at least one of the particles has an average primary particle diameter of 0.2 to 0.4 μm, and at least one of the particles has an average primary particle diameter of 0.01 to 0.
4. The transparent magnetic recording medium according to claim 1, wherein the thickness is 15 μm. 5. Inorganic particles having different average primary particle diameters and / or
And two or more kinds of organic polymer particles, at least one of the particles has an average primary particle diameter of 0.2 to 0.4 μm, Mohs hardness of 7 or more, and at least one of the particles has an average primary particle diameter of 0. The Mohs hardness is not more than 7 in the range of 0.01 to 0.15 [mu] m.
The transparent magnetic recording medium according to the above. 6. At least one particle containing at least two kinds of inorganic particles having different average primary particle diameters, wherein at least one particle is α-alumina having an average primary particle diameter of 0.2 to 0.4 μm. Has an average primary particle diameter of 0.01 to
6. The transparent magnetic recording medium according to claim 1, wherein the transparent magnetic recording medium is a metal oxide having a Mohs hardness of 7 or less, which is 0.15 μm. 7. The method according to claim 1, wherein 95% or more of said inorganic particles and organic resin particles dispersed in the coating layer have a size of 0.7 μm or less. Transparent magnetic recording medium. 8. The transparent magnetic recording medium according to claim 1, further comprising at least one silver halide emulsion layer sandwiched between a support and the opposite side to the back layer. 8. A transparent magnetic recording medium with a silver halide emulsion layer according to 4, 5, 6, or 7.