JPS63113930A - Magnetic paper and its production - Google Patents

Abstract

PURPOSE:To obtain magnetic paper having uniform quality by integrating core paper contg. fine magnetic powder and at least front paper to form the magnetic paper. CONSTITUTION:The front paper 2 and rear paper 3 are provided on both faces of the core paper 1 contg. the fine magnetic powder. The front paper 2 and rear paper 3 are prepd. as a raw material A by adding a neutral type cationic urea resin at 3% of the bone dry ratio of pulp to the raw materials formed by beating 75% N-BKP pulp and 25% L-BKP pulp in order to prevent the oxidation of the paper quality. The core paper 1 is prepd. as a raw material B by beating 85% N-BKP pulp, adding 15% ferrite of 0.8pH value and adding 1% a synthetic high polymer, i.e., carboxy methyl cellulose at 1% by the weight of the paper stock thereto in order to uniformize the fractions of the ferrite. The paper stock A is supplied as the material for the front paper 2 and rear paper 3 into a laid mold tank of a triple type paper machine. The paper stock B is supplied as the material for the core paper 1 into a short laid mold tank. Three layers are then made simultaneously to the paper, by which the magnetic paper is prepd. The stable magnetic paper which is uniformly dispersed with the magnetic powder and is integrally made of the three layers 1, 2, 3 is thus obtd.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to magnetic paper and a method for manufacturing the same, and more specifically, to magnetic paper used as recording paper, and
It relates to its manufacturing method. [Prior art l] Magnetic paper has recently been widely used in the information processing field, and magnetic materials such as ferric oxide (acicular FezO5), triiron tetroxide (FesO4), chromium dioxide, etc.
A magnetic paint is obtained by using fine powder of about 1 μm in size and a resin such as vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, acrylic, polyurethane, etc., and this is used to coat and form a base. Coating machines equipped with knife coaters, reverse roll coaters, application rolls, etc. are used for these operations, and the base material taken out from the unwinding machine is coated with a magnetic layer in the coating process, and the magnetic particles are separated by an orienting magnet. The particles are rotated or oriented in the longitudinal direction of the particles parallel to the base surface, dried in a dryer, and then wound up. The resin film, which is the base material that was removed, is
The surface of the magnetic layer of the paper is smoothed using a calender or the like. After surface treatment, the magnetic base film or paper is left at room temperature for several days or placed in a constant temperature bath for curing. The cured base film or paper is cut into a predetermined size and shape using a slitter, wound up, and commercialized. Problem 1 to be Solved by the Invention The technique of coating a magnetic layer on a resin film or paper as described above is difficult to obtain a uniform coated magnetic layer. Small resin filters require paper, making it impossible to increase the coating area.
It had the disadvantage of extremely low productivity. [Means for solving the problem] Therefore, the present invention provides an electronic calculation program card,
Mini computer program card, now available on J1! The purpose is to produce 1q of magnetic paper that can be used for magnetic recording paper that belongs to the classification of special cards such as management cards, parking ticket cards, time notes, airline tickets, etc., and core paper containing magnetic fine powder.
This magnetic paper is characterized by having at least a surface paper integrated therein. In addition, raw material pulp is added to the A stock of N, BKP pulp and L, BKP pulp, and the pulp is adjusted and disintegrated, treated to prevent paper oxidation and made water resistant, and then stocked.
The B stock of the P pulp was adjusted to a freeness of about 50''SR, transferred to a conditioning beater using a pulp pump, magnetic metal fine powder was added to distribute it uniformly in the pulp, and the paper stock was further made to adhere. Then, stock A is supplied to the circular mesh sifting tank, and stock B is supplied to the short mesh sifting tank. It is characterized in that it is made into paper together with the B paper stock using a three-layer paper machine or a two-layer paper machine, followed by drying, nine windings, and cutting steps to obtain magnetic paper.

【Example】

The magnetic paper according to the present invention will be described below along with its manufacturing method. First, Fig. 1 is an enlarged sectional view showing a three-layer magnetic paper, and Fig. 2 is an enlarged cross-sectional view showing a two-layer magnetic paper, where 1 is a core paper containing magnetic fine powder, and 2 is a surface paper. 3 indicates the back paper. The front paper indicated by the symbol 82 in FIGS. 1 and 2 is N, BK.
Consists of 75% P pulp, 25% L and BKP pulp,
First, add 1,000 yen of water to Hydrapalpa. Inject 9 g into this, add 9 to raw material pulp 50, adjust the concentration to 5%, and add 60
1 q of raw material A is obtained by disaggregating for 1 minute. The disintegrated raw material A is passed through a refiner, adjusted to a freeness of 40'SR1, using a freeness meter (Shopper Rigler type), transferred to a raw material chest, and adjusted using a pulp pump.
Transfer to a refining machine. To prevent paper oxidation, 3% neutral cationic urea resin is added to the absolute dry ratio of the pulp, and the pH is adjusted to 7 with sulfuric acid.
, 0 to 7.5, increase wet strength, impart water resistance, and transfer to raw material chest for stock. In addition, raw material B is 85% N, BKP pulp that is treated in the same way as raw material A, adjusted to a degree of freeness of about 50°SR, transferred to a raw material chest, adjusted with a pulp pump, and transferred to a beating machine. do. Compressed density 2.80g/cn+3, NoJ density 0.55
(1/cm'. Average particle size 0.64μ, moisture 0.10wt%, PHHO
Add 15% of magnetic metal fine powder (ferrite) of No. 28 to the adjusting beating machine, and adjust the FJ4 for about 30 minutes until the magnetic metal fine powder is uniformly dispersed in the N, BKP pulp, in order to completely adhere the magnetic fine powder to the surface paper. By adding 1% of synthetic polymer carboxymethyl cellulose to the paper stock, the paper stock is made to adhere, and is further treated with the same wet strength enhancement and water resistance treatment as raw material A, and then transferred to the raw material B chest for stock. do. Next, the paper stock adjusted to the above conditions is passed from the △ raw material chest to a pulp pump, and then sieved into two yen PJA. Supply to C. The raw material for the magnetic core paper is supplied from the raw material chest B to the short screen sieving tank (flow box) B by a pulp pump. The paper making conditions are: paper density of the paper stock for the front and back paper is 3%;
, paper density of magnetic core paper stock 2.5%, paper width 100
0mm, paper making speed 5m/min, and dryer vapor pressure 3kg/Cm2. In addition, the rice weight of the front and back papers using raw material A is 43 to 9/m
2. The thickness is 0.055mm, and the weight of the core paper is 34
ko/m2 and a thickness of 0.04 mm. Paper making is circular! Each type has one independent tank, and as shown in Figure 4, a circular mesh is rotated in the liquid tank, and the white water in the circular mesh is drained at an appropriately adjusted flow rate. A water level difference is created between the inside and outside of the cylinder, and water pressure is applied to the part of the cylinder that is immersed in the papermaking solution, causing the water on the outside to flow into the inside, and the paper stock on the screen becomes m When the mesh is removed from the stock liquid, the mesh is covered with a layer of wet paper that constitutes a papery texture. Then, the lower felt 2 or the pick-up felt 22 sequentially passes through the top of the circular mesh in the circular mesh sifting tank to pick up the paper layer, and the wet paper that has been papered comes into close contact with the pick-up felt 22 and transfers to a short screen. Next, the paper stock is passed through a short screen wire to form a paper web, and the water contained in the paper stock is sucked in a suction box, and the wet paper from which the water has been removed adheres to the wet paper on the surface paper using a short screen couch roll. It is further adsorbed to felt to form C double-layer wet paper, wet paper is formed in cylinder sifting tanks A and C, and it adheres to the two-layer wet paper (1) and (2>) to form three-layer wet paper. Formed, suction box 2
The magnetic powder is rotated or oriented in the length direction of the particles by an orientation magnet and guided to the felt, brought into contact with the surface of the dryer, and then the paper The water is evaporated and dried to 6-10%. The dried paper passes through a polisher, maintains a certain level of smoothness, and is wound up with a reel winder. In addition, rewinding is performed using the winder part if necessary. The paper that composes the three layers obtained through the above process is 120g
/ m2, thickness 0.15n+m, density o, 8g /c
A paper containing magnetic metal fine powder inside the three-layer structure of m3 is obtained, and it can be wound into a size according to the purpose and cut into a predetermined size using a cutting machine. The paper with the three-layer structure obtained through the above process,! Magnetic paper having a permanent magnet can be obtained by magnetizing it using an i-field generator. In addition, as shown in Fig. 2, using the above-mentioned raw materials, supplying the paper stock A to the circular mesh screening tank A, and supplying the paper stock B to the short mesh screening tank B, under the above papermaking conditions. A magnetic paper having a two-layer structure with the same paper quality A on the front side and paper quality containing magnetic metal fine powder on the back side is obtained. The resulting two-layered magnetic paper is used as a recording paper, and its recording density is adjusted to below low-density recording (210 BPI). Characters, designs, etc. are printed on the front surface, and the magnetism on the back side is applied to significantly increase the commercial value. It becomes possible to use it as a recording base paper that can be improved. (Effects of the Invention 1 As is clear from the above explanation, the magnetic paper and the method for manufacturing the same of the present invention have the following effects. (1) By magnetizing the core paper, Magnetic paper with permanent magnets can be obtained. (2) Since the magnetic powder is uniform, magnetic paper with uniform quality can be obtained. (3) As it is an application of papermaking technology, the thickness can be easily controlled. (4) Since it is based on pulp, it has higher heat resistance than plastic films. (5) To prevent counterfeiting, use a dandy roll equipped with a highly precise punching die to record one character with the desired white punching or black punching. Magnetic paper with a pattern is obtained.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of magnetic paper, and Figure 3 is magnetic paper! l
Fig. 4 is an explanatory diagram of a cylinder paper making tank, Fig. 5 is an explanatory diagram of a short paper making tank, and Fig. 6 is an explanatory diagram of a short paper machine. 1... Core paper 2... Front page 3... Back paper

Claims (2)

[Claims] (1) Magnetic paper that integrates a core paper containing magnetic fine powder and at least a surface paper. (2)N. BKP pulp and L. Raw material pulp is added to stock A of BKP pulp, adjusted, and disintegrated to treat the paper to prevent oxidation and provide water resistance. Adjust the B paper stock of BKP pulp to a beating degree of about 50° SR, transfer it to the adjusting beater using a pulp pump, add magnetic metal fine powder and distribute it uniformly in the pulp, and further, make the paper stock sticky. The paper stock A is supplied to the circular mesh sifting tank, the stock B is supplied to the short mesh sifting tank, and the paper stock A made here is fed to the paper stock B that is made in the short mesh sifting tank.
A method for producing magnetic paper, which comprises making paper together with paper stock in a three-layer paper machine or a two-layer paper machine, and then obtaining magnetic paper through the steps of drying, winding, and cutting.