JPH07172040A - Ink-jet magnetic composite recording sheet - Google Patents

Abstract

PURPOSE:To provide an ink-jet recording sheet which is excellent in coloring, absorptive properties of ink and surface strength and is capable of also recording magnetic information. CONSTITUTION:This sheet possesses a substrate, an ink receptive coating layer which is formed on one surface of the substrate and contains amorphous fine powder silica and a binder resin as main components and a magnetic recording layer which is formed on the opposite surface of the substrate and consists mainly of a magnetic powder and a binder resin, Gurley stiffness of the substrate to be regulated by the JAPAN TAPPI No.40 is within a range of 1000-3000mgf and a thickness of the substrate is within a range of 200-350mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material, and more specifically, it is used for various automatic system cards such as coupon tickets, gift certificate cards, prepaid cards, highway cards, etc. The present invention relates to an inkjet magnetic composite recording sheet that can be visualized by printing with an inkjet printer.

[0002]

2. Description of the Related Art The performance of ink jet printers using water-based inks, especially the improvement in printing speed, resolution, saturation, etc., enables high-speed absorption even on recording materials,
Higher characteristics such as high absorption capacity and regular ink bleeding are required, and so-called coated paper having an ink-receptive coating layer on the surface has been developed.

For example, Japanese Unexamined Patent Publication (Kokai) No. 62-158084 discloses a method for producing an ink jet recording medium having high water-based ink absorbency, color reproducibility and color density by using fine particle synthetic silica. That is, in order to meet the above-mentioned required characteristics, it is usually practiced to provide a coating layer containing a white pigment having excellent liquid absorption property such as fine particle synthetic silica as a main component on the surface of a base paper containing cellulose pulp as a main component. Has been done.

On the other hand, in recent years, with the rapid spread of telephone cards and orange cards, prepaid cards have been attracting a lot of attention, and their practical application is rapidly spreading in the fields of various distribution service industries including transportation. The widespread use of such magnetic recording cards is that the information storage capacity of the magnetic recording layer is large, that written information can be easily and accurately read, and that they can be easily processed by an automatic ticket gate or a vending machine. The reason is that it is possible and that it can process fractional amounts and is effective for labor saving.

As a balance display system for prepaid cards,
Conventionally, various methods such as a punch hole method, an electrophotographic method, an electrostatic recording method, a printing method using ink, a diazo copying method, and a thermal recording method have been adopted. The punch hole method has the disadvantages that the usage history is not clear and the punch waste is accumulated in the reader / writer since the accurate balance cannot be grasped only by the card. In addition, any recording method other than the heat-sensitive recording method requires development and fixing steps, and thus has problems such as an increase in size of the printing apparatus and high cost. On the other hand, the heat-sensitive recording method does not require these steps, so that the apparatus can be downsized and labor-saving, but there are problems such as storability and defective printing due to the sticking phenomenon of the thermal head. Therefore, a new recording method that solves these problems has been desired.

[0006]

SUMMARY OF THE INVENTION The present invention provides an ink jet magnetic composite recording sheet capable of recording magnetic information and capable of printing a high quality image at high speed using an ink jet printer using an aqueous ink. It is the one we are trying to provide.

[0007]

SUMMARY OF THE INVENTION The present inventors have conducted diligent research in order to achieve the above object in view of the present situation, and as a result, J
APAN TAPPI No. The Gurley stiffness specified in 40 is 1000 to 3000 mgf and the thickness is 200 to
By providing an ink-receptive coating layer containing amorphous fine powder silica and a binder resin as main components on one surface of the support in the range of 350 μm and providing a magnetic recording layer on the opposite surface,
It was found that printing with an ink jet method can provide a high-quality and highly colored image, and magnetic information recording is also possible, and completed the present invention.

That is, the ink jet magnetic composite recording sheet according to the present invention comprises a support and an ink receptive coating layer formed on one surface of the support and containing amorphous fine powder silica and a binder resin as main components. And a magnetic recording layer formed on the opposite surface of the support and containing magnetic powder and a binder resin as main components.
PAN TAPPI No. The Gurley rigidity defined by 40 is in the range of 1000 to 3000 mgf, and the thickness of the support is in the range of 200 to 350 μm.

As a support for the ink jet magnetic composite recording sheet of the present invention, neutral or acidic high-quality paper mainly containing natural pulp, medium-quality paper, recycled paper coated paper, art paper, etc., calcium carbonate, A uniaxially or biaxially stretched multi-layered thermoplastic resin film containing 8 to 65% of an inorganic fine pigment such as calcined clay, diatomaceous earth, talc, or silica. Axis or 2
In addition to the three-layer structure in which the axially stretched paper-like layers are bound, depending on the application, the paper-like layer and the base material layer may have, for example, four or more layers including a surface layer for the purpose of improving whiteness. A biaxially stretched multi-layered polyolefin sheet containing an inorganic fine powder pigment, and synthetic paper manufactured from opaque paper to semi-transparent trace paper depending on the amount and type of pigment added is used.

As the thermoplastic resin for this film, a polyolefin resin such as polyethylene, polypropylene, ethylene-propylene copolymer or ethylene-vinyl acetate copolymer is the main component, but in addition, polystyrene or acrylic ester is used. It is used by mixing a thermoplastic resin such as a copolymer. In addition, synthetic and natural resin films can be used. The basis weight of the sheet-like support is determined by the final use of the recording sheet and is preferably 100 to 300 g / m ² , but is not particularly limited.

JAPAN of the support used in the present invention
TAPPI No. The Gurley stiffness specified in 40 is
It is 1000 to 3000 mgf. Gurley stiffness 10
If it is less than 00 mgf, it is not suitable as a recording sheet because it is weak in elasticity and may be bent or bent when used as a card, and may not function as a recording card.
On the other hand, when the amount exceeds 3000 mgf, there are no problems such as folding endurance and bending endurance, but the running property during printing is impaired, and problems such as printing defects and running properties are also unsuitable.

The thickness of the base paper used in the present invention is 200
Is in the range of to 350 μm. If the thickness is less than 200 μm, it may be easily bent or bent during use, failing to function as a card, while if it exceeds 350 μm, paper running trouble may occur during printing.
High cost and unsuitable. Further, the ink jet magnetic composite recording sheet of the present invention can be printed with various pictures and characters according to the application, but the operability at that time is deteriorated, which is also unsuitable.

The amorphous finely divided silica used in the present invention is
The manufacturing method is roughly classified into a wet method and a dry method. The wet method can be obtained by using sodium silicate as a raw material and neutralizing with an acid to precipitate silica.
Further, it is divided into a sedimentation method and a gelation method. The dry method can be obtained by using silicon tetrachloride as a raw material and burning it with hydrogen and oxygen to precipitate silica. It is usually called white carbon, and is known as silicic acid anhydride, silicic acid hydrate, and the like. Moreover, these silicic acids are also utilized as aluminum silicate and magnesium silicate depending on the case.

The amorphous fine silica powder used in the present invention preferably has an average particle size of 0.5 to 15 μm. Further, for the purpose of absorbing ink, it is desirable that the oil absorption of synthetic silica is high and 100 to 400 ml /
100 g is preferred.

The pigment used in the present invention may be used in combination with other pigments, if necessary, in addition to the above-mentioned synthetic silica. Examples thereof include zeolite, calcium carbonate, diatomaceous earth, kaolin, calcined clay, talc, aluminum hydroxide, Pigments generally used for paper coating such as organic pigments (plastic pigments) can be used. The blending amount of such a pigment is preferably 30 to 80% by weight based on the total solid content of the coating layer. If it is less than 30% by weight, the ink absorbency becomes insufficient, and 80% by weight
If it exceeds, there is a concern that the strength of the coating layer may decrease, and it is not suitable because it is used for prepaid cards etc. unlike ordinary ink jet recording paper, because it is rough in use and print recording cannot be performed due to scratches, rubbing, etc. .

Examples of the binder resin of the present invention include polyvinyl alcohol and its derivatives, proteins such as casein, starch, and its starch derivatives, styrene-butadiene copolymers, methyl methacrylate-butadiene copolymers and other conjugated diene-based polymers. Latex, acrylic polymer latex such as polymers or copolymers of acrylic acid ester and methacrylic acid ester, vinyl polymer latex such as ethylene-vinyl acetate copolymer, or carboxyl group or cation of these various polymers Modified polymer latex containing functional groups such as functional groups, synthetic resin binder resins such as thermosetting resins such as melamine resins and urea resins, maleic anhydride copolymer resin resins, polyacrylamide resins, polymethylmethacrylate resins, polyurethane resins Series, unsaturated polyester Polymers such as fat-based, polyvinyl butyral-based, synthetic resin-based binder resins such as alkyd resin-based, which have good adhesiveness with pigments and good affinity with ink, improve liquid absorption, and therefore are preferred. Used.

The proportion of the binder resin used in the ink-receptive coating layer is 20 to 70% by weight of the total solid content of the coating layer,
It is preferably 25 to 60% by weight. If it is less than 20%, the adhesive strength will be insufficient, and there is a concern that the strength of the coating layer will decrease.
It is unsuitable because defects in the recording layer due to scratches, rubbing, etc. occur, making printing and recording impossible. On the other hand, when it exceeds 70%, the adhesiveness is increased, but the use ratio of the pigment is lowered, and as described above, there is a problem in the ink absorbency, which is not suitable.

In the ink jet magnetic composite recording sheet of the present invention, a magnetic recording layer is formed on the opposite surface with the support in between. This magnetic recording layer contains magnetic powder and a binder resin. As the magnetic powder, γ-iron oxide, cobalt-modified γ-iron oxide, barium ferrite, chromium oxide or the like can be used. As the binder resin, polyvinyl alcohol and its derivatives, proteins such as casein, styrene-butadiene copolymer, methylmethacrylate-butadiene copolymer, styrene-butadiene-methylmethacrylate copolymer, acrylic resin, vinyl acetate Latex or emulsion of resin, polyurethane resin, vinyl chloride resin,
A polyester resin, a vinyl chloride-vinyl acetate copolymer or the like can be used.

The magnetic paint containing these magnetic powder and binder resin as main components is prepared by using either an aqueous system or an organic solvent system, but the aqueous system is more economical and preferable. As the organic solvent, toluene, xylene, methyl ethyl ketone or the like can be used. Known coating equipment such as a bar coater, a roll coater and an air knife coater is applied to the coating for forming the ink-receptive coating layer and the magnetic recording layer of the present invention. The sheet provided with the ink-receptive coating layer on the support can be used as it is as the recording sheet of the present invention, but it should be treated with, for example, a super calender or a gloss calender to give the surface smoothness. Is also possible.

The coating amount of the ink absorptive coating layer obtained in the present invention is determined by the end use, and need not be unnecessarily increased as long as the ink absorptivity, recording characteristics, storage stability, opacity and the like are satisfied. It is used by appropriately selecting from the range of 3 to ²⁰ g / m ² . Ink-receptive coating layer is 3g / m
If it is less than ² , the ink absorption capacity is insufficient in many cases, and the image runs out, color bleeding occurs, the image becomes blurry, the drying is slow, and the ink is attached to the roll of the printer, hands, etc. and it becomes dirty. . However, 20 g /
When the ink-receptive coating layer having a thickness of more than m ² is provided, the coating layer is thick and the adhesion to the support is weakened, which often causes problems such as clogging of the head nozzle, which is also expensive. Will be things.

The coating amount of the magnetic recording layer obtained by the present invention is
It is determined according to the end use, and used by appropriately selecting from the range of 25 to 40 g / m ² .

[0022]

The present invention will be described in more detail with reference to the following examples, but of course the present invention is not limited thereto. In the following, parts and% mean parts by weight and% by weight.

Example 1 20 parts of light calcium carbonate was added to a slurry of 100 parts of bleached hardwood kraft pulp, 2 parts of cationic starch and 0.3 part of an alkenylsuccinic anhydride neutral sizing agent were added, and the mixture was thoroughly mixed. Mix and use as raw material for papermaking, using a Fourdrinier multi-cylinder paper machine to dry the water to 10%, and apply a 7% solution of oxidized starch with 4 g / m ² on both sides with a size press and dry to a water content of 7%. It was dried to produce a woodfree paper having a weight of 200 g / m ² . The Gurley stiffness of the obtained fine paper is 1240 mg.
f, the thickness was 210 μm. Paint on one side of the obtained fine paper using a test bar coater in a laboratory-1
At a rate of 11 g / m ² and dried to form an ink-receptive coating layer.
An ink jet magnetic composite recording sheet was manufactured by coating and drying at a rate of 0 g / m ² to form a magnetic recording layer.

Paint-1 Fine particle silicic acid 100 parts (Fineseal: Tokuyama Soda) Polyvinyl alcohol 40 parts (R-1130: Kuraray) Paint-2 γ-iron oxide 100 parts Polyvinyl alcohol 20 parts Styrene-butadiene latex 15 parts

Example 2 Multi-layer synthetic paper YUPO FPG-300 containing an inorganic pigment
(Gurley stiffness 2830 mgf, thickness 300 μm, made by Oji Oka Kasei Synthetic Paper Co., Ltd.) In a laboratory, using a test bar coater, paint-1 was applied at a rate of 12 g / m ² , and dried to obtain an ink receptive coating layer. Then, coating material-2 was coated on the opposite surface at a rate of 30 g / m ^{2 in} the same manner and dried to form a magnetic recording layer, thereby manufacturing an inkjet magnetic composite recording sheet.

Comparative Example 1 The woodfree paper obtained in Example 1 was machine calendered in the laboratory to give a Gurley stiffness of 870 mgf and a thickness of 185.
A fine paper of μm was prepared. Paint-1 was applied to one side of the obtained high-quality paper in a laboratory using a test bar coater.
It is applied at a rate of g / m ² and dried to form an ink-receptive coating layer, and subsequently 35 g / g of paint-2 is similarly applied to the opposite surface.
A magnetic recording layer was formed by coating at a ratio of m ² and drying to produce an inkjet magnetic composite recording sheet.

Comparative Example 2 20 parts of light calcium carbonate was added to a slurry of 100 parts of hardwood bleached kraft pulp, 2 parts of cationic starch and 0.25 part of an alkyl ketene dimer neutral sizing agent were added and mixed thoroughly. As a raw material for papermaking, a test paper machine was used to produce a high-quality paper of 350 g / m ² of tsubo. The quality paper obtained has a Gurley stiffness of 3200 mgf and a thickness of 395μ.
It was m. On one side of the obtained high-quality paper, a paint-1 was applied at a rate of 9 g / m ^{2 in} a laboratory using a test bar coater, and dried to form an ink-receptive coating layer, and then the other surface was similarly processed. The coating material-2 was applied at a rate of 30 g / m ² and dried to form a magnetic recording layer, and an inkjet magnetic composite recording sheet was manufactured.

Table 1 shows the evaluation results of these recording sheets. The inkjet recording characteristics and card suitability were evaluated by the following methods. Using an inkjet printer (BJC-820J: manufactured by Canon Inc.), ink absorbency, vividness of color development, and paper running property were measured. To evaluate the ink absorbency, the number of seconds until the printed ink dries was measured. 5 seconds or less is ○, 6 to 10 seconds is △,
11 seconds or more is shown by x. For the vividness of color development, the color development of each ink of black, yellow, magenta and cyan was visually evaluated. Good color development is indicated by O, insufficient color development is indicated by Δ, and defective color is indicated by X.

Regarding the paper running property, 10 sheets of paper were put in the sheet stack of the printer, and the state of paper feeding was examined without any human intervention. All of the 10 sheets were fed without problems, and those of 6 to 9 sheets were fed were marked with Δ, and those of which only 5 sheets were fed were marked with x. The card suitability evaluation was performed on the surface strength and the folding endurance. The evaluation of the surface strength is indicated by ◯ when it was rubbed with a nail and did not come off, Δ when it was slightly scraped on the surface, and x when it was completely peeled off. For the folding endurance evaluation, the number of times until the recording sheet was broken was measured using an MIT type folding endurance tester specified in JIS-P-8115. 10 ⁵ or more times ○ 10 ³
The number of times equal to or more than 10 ⁵ times was Δ, and the number less than 10 ³ times was X.

[0030]

[Table 1]

As can be seen from Table 1, the ink jet recording sheets obtained from the examples are equivalent in ink absorbency, color vividness and surface strength to those of the comparative example, but are suitable for cards (folding resistance). Strength, runnability)
The examples of the present invention are superior to the comparative examples.

[0032]

EFFECT OF THE INVENTION Since the ink jet printer recording paper of the present invention is excellent in ink absorption, color development, surface strength and folding endurance, it enables ink jet printing suitable for special applications such as prepaid cards. Is.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication D21H 19/38

Claims (1)

[Claims] 1. A support, an ink-receptive coating layer formed on one surface of the support and containing amorphous fine powder silica and a binder resin as main components, and formed on the opposite surface of the support. And a magnetic recording layer containing magnetic powder and a binder resin as main components,
APPI No. Gurley stiffness specified in 40 is 10
An ink jet magnetic composite recording sheet, wherein the thickness is in the range of 00 to 3000 mgf and the thickness of the support is in the range of 200 to 350 μm.