JPH01176325A - Magnetic recording paper - Google Patents

Abstract

PURPOSE:To shield a magnetic recording layer with an arbitrary color, to attain a printing to a magnetic recording surface and to enlarge information quantity by providing a pigment coating layer, which is composed of the white pigment of a >=1.58 refractive index, a colored pigment and adhesive agent, on a magnetic recording layer. CONSTITUTION:A magnetic recording paper has the magnetic recording layer, which has magnetic powder and the adhesive agent as a main component, on the side surface of an original paper and a water pigment coating layer is provided on the magnetic recording layer. In such a case, the main component of the water pigment coating layer is composed of the white pigment of the >=1.58 refractive index, the colored pigment and adhesive agent. As the original paper, the high quality paper of basis weight 40-300g/m<2> and a converting paper, etc., can be used, however, it is not especially limited. Thus, the lowering of the effective magnetic characteristic of the magnetic recording layer is suppressed as much as possible and the hue of the magnetic powder itself is completely shielded with the arbitrary color. Then, the magnetic recording paper can be obtained to have enough printing aptitude in the magnetic recording surface.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to magnetic recording paper. In particular, it relates to a magnetic recording paper in which an aqueous pigment coating layer having an arbitrary color is provided on a magnetic recording layer.

(B) Conventional technology Conventional magnetic recording paper, which has a magnetic recording layer on one side of base paper, is processed in vending machines due to the large information storage capacity of the magnetic recording layer, the ease and accuracy of reading written information, etc. It is widely used for train tickets, commuter passes, parking tickets, expressway passes, etc., as it can save labor. Recently, it has also come to be used for cards such as prepaid cards. On the other hand, other necessary visible information is printed directly on the opposite side of the magnetic recording layer, or by thermal transfer recording method, chelate recording method, thermosensitive recording method, etc. Among these, the structure of the recording device , thermal recording methods are frequently used due to their ease of handling and maintenance.

However, most of the magnetic recording layers of conventional magnetic recording paper have a hue due to the magnetic powder itself, that is, a dark hue such as brownish-brown or blackish-brown, which impairs the aesthetic appearance and design, and also makes it difficult to print on the magnetic recording surface. However, no consideration was given to printability. Therefore,
As a method to solve these problems, when forming the magnetic recording layer, there is a method of adding a coloring pigment to the magnetic paint to color the magnetic recording layer, and a method described in Japanese Patent Application Laid-Open No. 62-20499.
No. 1 proposes a method of applying a white pigment paint onto a magnetic recording layer.

(C) Problems to be Solved by the Invention However, in the conventional method of adding colored pigments to magnetic paint, since the magnetic particles themselves are strongly colored in a dark color, it is difficult to color the magnetic recording layer in a bright hue. This is impossible, and all images are colored in dark hues with low brightness and saturation.

Furthermore, if a large amount of colorant is added, the original function of the magnetic recording layer will be impaired.

On the other hand, in the method of applying a white pigment paint onto the magnetic recording layer, the hue is only white or pale yellow, and it is necessary to increase the amount of paint applied in order to obtain sufficient hiding power.

In other words, the problem of deterioration of magnetic properties remained.

(D) Means for Solving the Problems As a result of intensive research to solve the above problems, the present invention provides a magnetic recording layer mainly composed of magnetic powder and adhesive on one side of base paper, and furthermore, In magnetic recording paper provided with an aqueous pigment coating layer, the effective magnetism of the magnetic recording layer is improved by using a white pigment with a refractive index of 1.58 or more, a colored pigment, and an adhesive as the main components of the aqueous pigment coating layer. It was discovered and completed that it is possible to obtain magnetic recording paper that suppresses the deterioration of characteristics as much as possible, completely hides the hue of the Kazumagnetic powder itself with any color, and has a magnetic recording surface with sufficient printability. .

The technical matters of the present invention will be explained in detail below.

First, as the base paper, high-quality paper with a tsubo f of 140 to 300 g/nr, processed base paper, etc. can be used, but there is no particular limitation. The magnetic recording layer provided on the base paper contains magnetic powder and adhesive as main components, and the magnetic powder may be γ-iron oxide, cobalt-modified γ-iron oxide, barium ferrite, chromium oxide, or the like. Adhesives include water-soluble adhesives such as polyvinyl alcohol and casein, latex emulsions such as styrene-butadiene copolymers, acrylic resins, and vinyl acetate resins, polyurethane resins, vinyl chloride resins, and polyester resins. can be used. Magnetic paints containing these magnetic powders and adhesives as main components are prepared either in an aqueous system or an organic solvent system, but an aqueous system is more economical and preferable. Toluene, xylene, butanol, etc. can be used as the organic solvent.

The magnetic paint thus prepared is applied to a base paper using an air knife coater, roll coater, bar coater, etc. to form a magnetic recording layer.

Next, in providing the aqueous pigment coating layer of the present invention on the magnetic recording layer, the white pigment with a refractive index of 1.58 or more used is titanium oxide (anatase type refractive index 2.55, rutile type refractive index 2. .62), fired ray (refractive index 1.62),
Plastic pigment (refractive index 1.59), zinc oxide (refractive index 2°00), barium sulfate (refractive index 1.64)
, magnesium oxide (refractive index 1.74), zircon oxide (refractive index 2.40), part of calcium carbonate (refractive index 1
．． 58 to 1.66), and two or more types may be used in combination. By using these white pigments, high hiding power and sufficient printability can be obtained. on the other hand,
Pigments with a refractive index of less than 1.58, such as clay (refractive index of 1.58).
56), talc (refractive index 1.54), silica (refractive index 1
．． 48), a part of calcium carbonate (refractive index 1.48-1
．． 57) etc., the magnetic recording layer has low hiding power and requires a large coating amount, resulting in a loss of magnetic properties.

Furthermore, the coloring pigment has the effect of improving the hiding power of the magnetic recording layer, the effect of improving the aesthetic appearance and design, and the effect of increasing the printing effect.

Specifically, carbon black, acetylene black,
Black pigments such as lamp black, bone black, graphite, iron black, mineral black, aniline black, cyanine black; yellow lead, zinc yellow, barium chromate, cadmium yellow, yellow iron oxide, ocher, titanium yellow, lead cyanamide, lead Calcium acid, Naphthol Yellow S, Hansa Yellow 10G1 Hansa 10-5G, Hansa Yellow 3G, Hansa Yellow G, Hansa Yellow GR, Hansa Yellow A, Hansa Yellow RN, Hansa Yellow R1 Pigment Yellow, Benzidine Yellow, Benzidine Yellow G, Penzidine Yellow GR, Permanent Yellow N CG, Pal Can Fast Yellow 5G, Palcan Fast Yellow R1 Tartrazine Lake, Quinoline Yellow Lake, Anthragen Erotic
Yellow pigments such as 6G L, Permanent Yellow FGL, Permanent Yellow HIOG, Permanent Yellow HR, Anthrapyridine Yellow; Red Yellow Pigment, Chrome Vermilion, Sudan ■, Permanent Orange, Lysol Fast Orange, Permanent Orange GTR.

Orange pigments such as Hansa Yellow 3R, Palkan Fast Orange GG, Benzidine Orange G, Belsian Orange, Pink Slen Brilliant Orange GK, Pink Slen Brilliant Orange RK, Pink Slen Brilliant Orange; Brown pigments such as amber, permanent brown, and para brown; Red pepper, red lead, silver vermilion, -cadmium red, cadmium mercury red, antimony vermilion, permanent red 4R, para red, fire red, parachlororthonitroaniline red, resol fast scarlet G, prillian fast scarlet, vermilion, brilliant carmine BS , Permanent Red F2R, Permanent Red F4 R, Permanent Red FRL, Permanent Red FRLL
, Permanent Red F4RH, Fast Scarlet VD, Palkan Fast Lupine B1 Palkan Fast Pink G1 Light Fast Red Toner B1 Light Fast Red Toner R, Permanent FB, Pyrazolone Red, Lysol Red, Lake Red C Luki Red D1 Anthosine B, Brilliant Scarlet G
1 Resor Pulvin G K, Permanent Red F
5 R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2R, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B1 Rhodamine Lake Y1 Alizarin Lake, Thioindigolet B
, Thioindigoletone, Permanent Red FGR1
Red pigments such as PV Carmine HR, Monolite Fast Red YS, Permanent Bordeaux L; Violet pigments such as Cobalt Purple, Manganese Purple, Fast Violet B1 Methyl Violet Lake, Dioxine Violet; Ultramarine,
Navy Blue, Cobalt Blue, Cerulean Blue, Gosu, Alkaline Blue Lake, Peacock Blue Lake, Peaco Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Pink Suren Blue RS, Pink Suren Blue BC, Indigo, etc. Blue pigments: chrome green, zinc green, chromium oxide, pyridian, emerald green, cobalt green, pigment green B, naphthol green B, green gold, acid green lake, malachite green lake, phthalocyanine green, polychlorobrome, copper phthalocyanine, etc. There are green pigments, etc., and one type or two or more types can be used as necessary.

Furthermore, adhesives include polyvinyl alcohol, starch and its derivatives, cellulose derivatives such as methoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose, polysodium acrylate, polyvinylpyrrolidone, acrylic acid amide-acrylic ester copolymer, Water-soluble adhesive of acrylic acid amide-acrylic ester-methacrylic acid copolymer, styrene-maleic anhydride copolymer alkali salt, isobutylene-maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, etc. agents, polyvinyl acetate, polyurethane, styrene-butadiene copolymer, polyacrylic acid, polyacrylic acid ester, vinyl chloride-vinyl acetate copolymer,
Latex emulsions such as polybutyl methacrylate, ethylene-vinyl acetate copolymer, styrene-butadiene-acrylic copolymer, etc. can be used.

Such a water-based pigment paint containing a white pigment, a colored pigment, and an adhesive as main components is sufficiently dispersed and prepared using various mixers commonly used in water-based paper coating methods. At this time, dispersants, lubricants, waterproofing agents, antifoaming agents, paint viscosity modifiers, and the like can be appropriately blended as auxiliary agents.

The water-based pigment paint thus prepared is applied onto the magnetic recording layer provided on the base paper using an air knife, blade coater, roll coater, gravure coater, etc., and dried.
An aqueous pigment coating layer is provided. Furthermore, in order to smoothen the pigment coating layer, it is effective to perform gloss calendering or supercalendering to further improve printability.

It is necessary that the pigment coating layer does not reduce the magnetic properties of the magnetic recording layer, but since the water-based pigment coating of the present invention has excellent hiding properties, even with a small coating amount, it can produce vivid colors with sufficient printability. A colored coating layer is obtained. The coating amount is 2 to 20 g/1rI2, preferably 3 to 10 g/1rI2.
m'', but no deterioration in magnetic properties is observed at coating amounts within this range.

Furthermore, on the other side of the base paper, on which a magnetic recording layer and an aqueous pigment coating layer are provided, if necessary, there is a heat-sensitive recording layer or chelate layer containing, for example, a colorless leuco dye and a color developer that develops the colorless leuco dye in its infancy. A recording layer may also be provided.

(E) Examples The present invention will be further explained in more detail with reference to Examples. Note that "parts" in the examples indicate "parts by weight."

Example 1 [Magnetic paint composition] γ-iron oxide IOO part 10% polyvinyl alcohol aqueous solution 100 parts Styrene-butadiene latex (solid content 48%) 52 parts Melamine-formaldehyde resin (solid content 40%) 12.5 parts [aqueous Pigment paint composition] Titanium oxide (anatase type) 100 parts Phthalocyanine green 30 parts 10% sodium hexametaphosphate aqueous solution 3 parts 20% phosphate ester modified starch aqueous solution 75 parts Styrene-butadiene latex (solid content 48%) 31 parts Calcium stearate Dispersion (solid content 40%) 5 parts Melamine-formaldehyde resin (solid content 40%) 5 parts A magnetic paint was prepared with the above magnetic paint composition, and the weight was 157 g/tr.
A magnetic recording layer having a coating weight of 40 g/m 2 was obtained by coating onto I2 processed base paper.

Next, a water-based pigment paint was prepared with the above-mentioned water-based pigment paint composition and coated on the magnetic recording layer to provide a green colored pigment coating layer with a coating amount of 10 g/i to obtain the magnetic recording paper of the present invention.

Example 2 A water-based pigment paint was prepared by replacing phthalocyanine green with benzidine yellow in the water-based pigment paint composition of Example 1, and coated on the magnetic recording layer to apply a yellow pigment at a coating amount of 10 g/m''. A magnetic recording paper of the present invention was obtained by providing layers.

Example 3 A water-based pigment paint was prepared by replacing the titanium oxide in the water-based pigment paint composition of Example 1 with fired ray, and applied it on the magnetic recording layer to produce a green colored pigment with a coating amount of 10 g/lr+''. A coating layer was provided to obtain the magnetic recording paper of the present invention.

Example 4 A water-based pigment paint was prepared by replacing phthalocyanine green with benzidine yellow in the water-based pigment paint composition of Example 3, and coated on the magnetic recording layer at a coating amount of 10 g/Tn'.
A yellow pigment coating layer was provided to obtain a magnetic recording paper of the present invention.

Comparative Example 1 A water-based pigment coating was prepared by replacing titanium oxide with kaolin in the water-based pigment coating composition of Example 1, and coated on the magnetic recording layer to form a green colored pigment coating layer with a coating amount of 10 g/Tr1''. A magnetic recording paper was obtained.

Comparative Example 2 The water-based pigment paint of Comparative Example 1 was applied onto the magnetic recording layer at a coating amount of 3.
A magnetic recording paper was obtained by providing a pigment coating layer colored green so as to have a concentration of 0 g/i.

Comparative Example 3 A water-based pigment paint was prepared by replacing titanium oxide with talc in the water-based pigment paint composition of Example 1, and coated on the magnetic recording layer, and colored green with a coating amount of 10 g/tn. A pigment coating layer was provided to obtain magnetic recording paper.

Comparative Example 4 The water-based pigment paint of Comparative Example 3 was applied onto the magnetic recording layer at a coating amount of 3.
A magnetic recording paper was obtained by providing a pigment coating layer colored green so as to have a weight of 0 g/tn.

Comparative Example 5 Table 1 shows the quality evaluation results of the magnetic recording papers obtained in Examples 1 to 4 and Comparative Examples 1 to 5, in which the aqueous pigment coating layer of the present invention was not provided in Example 1. As shown in Table 1, in the magnetic recording paper of the present invention, the magnetic recording layer was completely hidden by the colored pigment coating layer, and the magnetic properties were not impaired. Furthermore, there was no problem with the suitability for printing on magnetic surfaces with general printing inks and suitability for issuing tickets.

(F) Effects of the Invention As is clear from the examples, the magnetic recording paper of the present invention is capable of providing a pigment coating layer on the magnetic recording layer consisting of a white pigment with a refractive index of 1.58 or more, a colored pigment, and an adhesive. Therefore, the magnetic recording layer can be hidden with any color, resulting in a beautiful appearance. It also makes it possible to print on a magnetic recording surface, increasing the amount of information. Moreover, the effective magnetic properties of the magnetic recording layer are hardly affected, and a magnetic recording paper suitable for issuing tickets, etc., can be obtained.

(Margin below) Table 1 0 good Δ possible × Not possible

Claims (1)

[Claims] In a magnetic recording paper in which a magnetic recording layer mainly composed of magnetic powder and adhesive is provided on one side of a base paper, and an aqueous pigment coating layer is further provided on the magnetic recording layer, the main component of the aqueous pigment coating layer has a refractive index. 1. Magnetic recording paper characterized by comprising a white pigment of 1.58 or more, a colored pigment, and an adhesive.