JP3022142B2 - Strips with pearl luster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pearlescent strip used for anti-counterfeit paper and design paper. For more information,
Pearls with pearl luster on the surface of the paper are distributed over the entire surface or in part, and are especially used for anti-counterfeiting paper with anti-counterfeiting ability by color copiers and design paper with excellent design properties And a strip having:

[0002]

2. Description of the Related Art The accuracy of recent copying machines has been remarkably improved, and in particular, electrophotographic color copying machines have facilitated forgery of various securities. Therefore, various counterfeiting prevention means have been considered, one of which utilizes a current copying machine having a brilliant property, for example, utilizing the inability to reproduce a metal color or an interference color.

For example, there is a paper proposed in Japanese Utility Model Application Laid-Open No. 58-168754, in which a bright plate such as aluminum foil having a remarkable metallic color is provided on a base paper to make copying impossible. When this is copied by a copying machine, the character pattern applied to the paper is copied because the entire surface of the paper is darkened due to the glitter of the foil surface, and cannot be read. However, this paper has the drawback that the bright plate area is large and the metal color is emphasized, which makes it uncomfortable and inevitably increases the cost. There is also a problem that it becomes difficult to recover the used paper from the viewpoint of reuse.

[0004]

SUMMARY OF THE INVENTION The present inventors have filed Japanese Patent Application No.
Japanese Patent No. -1140909 proposed a forgery prevention paper which solved the above problem. The gist of the present application is a forgery-prevention paper in which glittering strips are ubiquitously present on the surface of a base paper, wherein the strips have a performance capable of adhering to the base paper in a paper making process. It is prevention paper. This forgery prevention paper uses a binder or film having a hot water dissolving temperature of 60 to 80 ° C. as one of the constituent elements of the strip in order to be able to adhere to the base paper during the paper making process. Since these are easily dissolved at the time of processing waste paper or waste paper, there is an advantage that the papermaking fibers can be easily collected.

[0005] In this application, the present inventors have proposed that a paint comprising a pearl pigment and a binder be applied to the surface of a base paper, and that it be fragmented and ubiquitously applied to the base paper surface. Strips using pearl pigment as a glittering substance emit a gentle glitter, so they do not feel uncomfortable even when mixed into paper, have excellent design, and the color is not reproduced with a color copier, so it is an excellent counterfeit Has preventive ability. The present inventors have further studied forgery prevention paper and design paper using this pearl pigment, and have disclosed in Japanese Patent Application Nos. 5-218161 and 5-2617.
No. 69, Japanese Patent Application No. 5-317396, Japanese Patent Application No. 5-343
No. 106 etc. was filed.

[0006] As described in the above-mentioned application, as described in the above-mentioned application, the flakes obtained by applying a paint comprising a pearl pigment and a binder to the surface of a base paper are used. It is necessary to dissolve by the heat of the drying zone. This allows the strip to adhere firmly to the paper.

As a result of the study by the present inventors, it has been found that the adhesiveness and the glitter have an inverse correlation. In order to improve the adhesiveness, it is necessary to increase the compounding ratio of the binder, which inevitably reduces the ratio of the pearl pigment and decreases the glitter. Conversely, in order to improve the glitter, it is necessary to lower the compounding ratio of the binder, and the adhesion is reduced. An object of the present invention is to solve these problems. Specifically, it is an object to obtain a strip having excellent glitter and excellent adhesiveness.

[0008]

Means for Solving the Problems The pearl pigment coating layer is intended to be a formulation with as high a glitter as possible, that is, a formulation in which the ratio of the pearl pigment added is high, but the minimum coating layer strength is satisfied. It is necessary. The results examined by the present inventors show that when the amount of the binder is reduced to a level that satisfies the minimum coating layer strength, the adhesive strength between the strip and the base paper in the drying zone of the paper machine is significantly reduced. Was.

The present inventors have further studied. As a result, a strip having a two-layer coating layer was developed, in which a transparent binder coating layer was further provided on a pearl pigment coating layer in which the pearl pigment addition ratio was increased. The gist of the present invention is that 85 to 50 parts by weight of pearl pigment (all parts by weight used in the present invention indicate dry parts by weight, hereinafter the same) on both sides of base paper, insoluble in cold water and in hot water A pearl pigment coating layer mainly composed of 15 to 50 parts by weight of a soluble binder is provided, and a binder coating layer insoluble in cold water and soluble in hot water is further provided thereon to be fragmented to increase pearl luster. The purpose of the present invention is to obtain a strip having the same.

Next, the present invention will be described in detail. The base paper used in the present invention is softwood bleached kraft pulp (NBKP),
It mainly consists of wood pulp such as hardwood bleached kraft pulp (LBKP), bast fiber such as mulberry and mitsumata, and paper pulp such as cotton pulp and bamboo pulp. Wet paper strength enhancers such as resins, sizing agents such as rosin, fluorescent whitening agents such as diaminostilbene disulfonic acid derivatives, fixing agents, etc. are used in combination as appropriate, and usually have a freeness of 550 to 250 ml.
C. S. F. The paper is usually made with a basis weight of 25 to 70 g / m ² using a known paper machine such as a fourdrinier paper machine or a round paper machine.

According to the results of various studies conducted by the present inventors, the use of a polyolefin synthetic pulp in combination with the production of base paper
It has been found that there is an advantage that the life of a punching blade or a cutter blade when manufacturing a strip can be extended. Usually, 2 to 30 parts by weight of a polyolefin-based synthetic pulp is used in combination with 98 to 70 parts by weight of paper pulp. If the amount is less than 2 parts by weight, the effect of extending the life of the blade is not recognized, and if it exceeds 30 parts by weight, it becomes difficult to make a base paper and the strength is reduced. Considering the balance of blade life, ease of making base paper, and strength, the polyolefin-based synthetic pulp is most preferably 5 to 20 parts by weight.

When the binder used in the present invention is dissolved in the wet part of a paper machine, the pearl pigment coating layer and the binder coating layer are eluted. Is required to have the property of swelling or dissolving due to the heat and firmly adhering to the base paper. In the present invention,
Various water-soluble binders such as starch-based, methylcellulose-based, carboxylated cellulose-based, hydroxyethylcellulose-based, polyvinyl alcohol (hereinafter referred to as PVA)
), Polyvinylpyrrolidone, vinyl ethyl ether-maleic anhydride copolymer, polyacrylic acid, polyethylene oxide, etc., which are insoluble in cold water and soluble in hot water.

As the binder, it is preferable to use a PVA-based binder because it is relatively inexpensive and readily available, has an appropriate physical strength, and is excellent in transparency. PVA
The solubility in water is largely controlled by the degree of polymerization and the degree of saponification, especially the degree of saponification. For example, if the saponification degree is 88% or less, about 20%
It is completely dissolved in water of 、 C and has a saponification degree of 97%.
With hot water at ℃, those completely saponified dissolve at about 80 ℃ for the first time.

When a binder having a hot water dissolution temperature of less than 60 ° C. is used, the binder tends to excessively swell or dissolve in the drying zone of the papermaking process, and the pearl pigment coating layer cannot maintain a good shape. And the melting temperature is 80
If the temperature exceeds ℃, it is difficult and dangerous to raise the slurry to this temperature when recovered as waste paper or waste paper. Therefore, the melting temperature is preferably 60 to 80 ℃.

As the pearl pigment used in the present invention, known pearl pigments such as natural pearl essence, mica powder, titanium oxide-coated mica powder, basic carbonate and fish scale foil can be used.
These production methods are described in JP-B-35-5367 and JP-B-39-2.
8885, JP-B-47-29569, JP-B-48-
23179, JP-B-53-47375, JP-B-56
-39669, JP-B-58-7767, JP-B1-
Any of the techniques described in Japanese Patent No. 22873 and Japanese Patent Publication No. 4-48812 can be used.

Some pearl pigments emit an iris color,
The feature is that the hue changes depending on the viewing angle. As the pearl pigment used in the present invention, it is particularly preferable to use the pearl pigment which emits this iris color, since the pearl pigment is excellent in the design property and the anti-counterfeiting ability is enhanced. For example, if strips that emit green, red, and blue irises are separately manufactured, and paper is manufactured using these three types of strips, the iris colors that are independent of the three colors can be visually recognized. The prevention ability can be further improved. Also, if the iris color of one side of the pearl pigment coating layer is made different from the iris color of the other side, when the fine pieces are sprinkled on the base paper, there is a probability that which side will come to the surface. / 2
There is also an advantage that the labor of separately manufacturing different color strips can be omitted.

In the present invention, pearl pigments 85-85 are provided on both sides of the base paper.
A pearl pigment coating layer mainly comprising 50 to 50 parts by weight of a binder such as a PVA-based binder which is insoluble in cold water and soluble in hot water is provided. When the pearl pigment exceeds 85 parts by weight, the glittering property is excellent, but the strength of the pearl pigment coating layer becomes insufficient, and when it is less than 50 parts by weight, the glittering property becomes insufficient. If necessary, auxiliary materials such as a dispersant, an antifoaming agent, a coloring dye, and a fluorescent whitening agent can be used in the coating liquid as long as the object of the present invention is not impaired. This pearl pigment coating layer is usually provided using a known coating machine such as an air knife coater or a roll coater in an amount of ^{2 to} 10 g / m ² (dry weight, hereinafter the same) per one side of the base paper.

In the present invention, it is necessary to provide a binder coating layer such as a PVA-based binder which is insoluble in cold water and soluble in hot water, on the coating layer. Strips without this layer are:
In the drying zone of the papermaking process, it does not adhere strongly to the base paper.
This coating layer is usually formed using a known coating machine such as an air knife coater or a roll coater, usually at a rate of 2 to 10 g / one side.
provided on both sides with m ^2.

The thus-obtained raw material for strips may be further subjected to means for preventing forgery such as microprinting or the like, as appropriate. As described above, a raw material for manufacturing a strip is completed, and the strip is manufactured using this. In the present invention, as the shape of the strip, any shape such as a circle, an ellipse, a square, a rectangle, a triangle, a pentagon, a star, and a crescent can be selected. As the method, an arbitrary method such as a method of punching using a tooth profile having the above shape, a method of slitting a raw material with a microslitter and cutting the material can be adopted. The size of the strip is usually 0.2-1
It is about 0 mm.

The strips are made so as to be ubiquitous near the entire surface of the base paper at the time of forming the base paper, or so as to be ubiquitous in the form of a streak to produce a design paper or a forgery prevention paper. As a method of arranging the strips ubiquitously, the present inventors have disclosed a method disclosed in Japanese Patent Application No. Hei.
No. 3,173,395, using a device as proposed in Japanese Patent Application No. Hei.
As proposed in U.S. Pat. No. 2,617,695, a method of making a paper by including a strip in the outermost layer of the multilayer paper may be employed.
As a method of ubiquitous streaks, Japanese Patent Application No. 5-34
An apparatus such as that proposed in No. 3106 can be employed.

The paper web can be colored to enhance its design and anti-counterfeiting ability, can have a see-through pattern, and can be embossed. The paper web thus formed is heated and dried in a drying zone of a paper machine such as a cylinder drier or a Yankee drier. In the initial stage of drying, the paper web contains a large amount of water, so hot water also comes into contact with the strips, and the hot water-soluble binder swells or dissolves only a small part of it, and eventually adheres firmly to the paper by drying I do.

[0022]

EXAMPLE 1 20 parts by weight of softwood bleached kraft pulp (NBKP) and 80 parts by weight of hardwood bleached kraft pulp (LBKP) were 350 m
IC · S. F. And a paper strengthening agent (trade name “Polystron 191”, manufactured by Arakawa Chemical Industry Co., Ltd.) 0.3
1.0 part by weight of a sizing agent (trade name “Size Pine E” manufactured by Arakawa Chemical Industry Co., Ltd.) and an appropriate amount of a sulfuric acid band to prepare a paper stock, and using a fourdrinier paper machine to obtain a basis weight of 35 g / the base paper of m ² and papermaking. 85 parts by weight of a pearl pigment emitting a red iris color (trade name “Marine Raster Pigments, Highlight Super Red 9430Z”, manufactured by Marl Corporation) on both sides of the base paper, hot water solubility 6
A 20% by weight aqueous paint composed of 15 parts by weight of PVA (manufactured by Kuraray Co., Ltd.) at 0 ° C. was applied at a rate of 2 g / m ² per side using an air knife coater to form a pearl pigment coating layer. Further, a coating consisting of a 7% by weight aqueous solution of PVA (same as above) was applied on both sides at a rate of 2 g / m ² per side using an air knife coater to form a binder coating layer.
Then, it was punched into a rectangle of 3 mm × 4 mm using a punching machine to produce strips.

Example 2 A pearl pigment coating layer was coated with 50 parts by weight of pearl pigment and PVA.
A strip was produced in the same manner as in Example 1 except that the amount was 50 parts by weight, the coating amount was 5 g / m ² , and the coating amount of the binder coating layer was 5 g / m ² .

Example 3 19 parts by weight of NBKP, LBKP
79 parts by weight of polyethylene synthetic pulp (trade name "S
WP ", manufactured by Mitsui Petrochemical Industry Co., Ltd.)
The same strip as in Example 1 was produced except that the coating amount of the pearl pigment coating layer was 5 g / m ² and the coating amount of the binder coating layer was 5 g / m ² .

Example 4 The pulp used for the base paper was 20 parts by weight of NBKP and LBKP
A strip was prepared in the same manner as in Example 2 except that 40 parts by weight, 40 parts by weight of a polyethylene-based synthetic pulp (same as above), and the coating amount of the pearl pigment coating layer were 2 g / m ² .

Comparative Example 1 90 parts by weight of pearl pigment, PVA
The same strip as in Example 1 was produced except that the amount was 10 parts by weight and the coating amount of the binder layer was 5 g / m ² .

Comparative Example 2 40 parts by weight of pearl pigment, PVA
A strip was produced in the same manner as in Example 1 except that the amount was 60 parts by weight and no binder layer was provided.

Using the strips described above, anti-counterfeit paper was manufactured. 20 parts by weight of NBKP and 80 parts by weight of LBKP were added to 350 ml C.S. F. 10 parts by weight of clay, 0.3 parts by weight of paper strength agent (trade name "Polystron 191", manufactured by Arakawa Chemical Industries, Ltd.), and a sizing agent (trade name "Size Pine E" Arakawa Chemical) 1.0 part by weight (manufactured by Kogyo Co., Ltd.) and an appropriate amount of a sulfuric acid band were added to prepare a stock. When making a base paper having a basis weight of 110 g / cm ² using a Fourdrinier paper machine, each of the above strips is applied to a paper sheet immediately after slicing, as disclosed in Japanese Patent Application No. 5-31739.
Sprinkle evenly using the apparatus described in 5. The sprinkler was adjusted so that the distribution density of the strips was 30 to 40 per 10 × 10 cm ² of paper. Thereafter, drying was performed using a multi-cylinder cylinder dryer according to a conventional method.

Table 1 shows the evaluation results of the examples and comparative examples.

[0030]

[Table 1]

The evaluation was performed by the method described below. The results are evaluated by a five-point method, and five points are the best, one point is the worst, and three or more points are practically usable. 1) Pearl pigment coating layer strength: The paper after the papermaking was applied to an offset printing machine, and the strip was peeled between the pearl pigment coating layers, and evaluated by the amount taken on a blanket. 2) Sharpness and punching suitability: Strips were manufactured with a guillotine cutter and a punching machine, and evaluated for blade durability. 3) Glitter: The glitter of the strips contained in the paper after papermaking was visually evaluated. 4) Adhesive strength to base paper: The paper after the papermaking was applied to an offset printing machine, and the evaluation was made based on the amount of strips taken on a blanket.

Further, 5 parts by weight of the paper of the example and the comparative example, 95 parts by weight of water, and 0.1 part by weight of caustic soda were charged into a high-concentration pulper and rotated while blowing live steam to raise the temperature to 60 ° C. The paper and the strips were easily disintegrated, and the papermaking pulp could be easily collected.

[0033]

As described above, the strip of the present invention is constituted and has remarkable effects as described below. 1) The strip has an advantage of being excellent in glitter and not giving a sense of incongruity, and is excellent in design. 2) Even if copying is attempted with a color copying machine, the glitter of the strips cannot be reproduced, so that it is possible to immediately determine whether or not the paper is forged. 3) When the coating layer has a two-layer structure, that is, a configuration of a pearl pigment coating layer and a binder layer, contradictory properties such as glitter and adhesiveness can be simultaneously improved. 4) If necessary, by using a polyolefin-based synthetic pulp in combination with the base paper, the cutting properties are improved, and strips with improved durability of the guillotine cutter and the blade of the punching machine can be manufactured. 5) Papermaking fibers can be easily recovered from waste paper or waste paper. 6) Taking advantage of such characteristics, strips of the present invention can be used as check paper, stock paper, bond paper, banknote paper, gift certificate paper, passport paper, various ticket papers, counterfeit prevention papers such as a ticket, posters, It can be suitably used for design papers such as brochures, greeting cards, envelope paper, and labels.

Continued on the front page (56) References JP-A-4-263697 (JP, A) JP-A-4-97900 (JP, U) JP-A-5-66085 (JP, U) (58) Fields surveyed (Int) .Cl. ⁷ , DB name) D21H 17/00-27/42

Claims (5)

(57) [Claims] 1. A pearl pigment of 85 to 50 parts by weight on both sides of a base paper, a binder 15 to 50 insoluble in cold water and soluble in hot water.
A pearl pigment coating layer consisting mainly of parts by weight was provided, and further a binder coating layer insoluble in cold water and soluble in hot water was further provided thereon to give a pearl luster characterized by being fragmented. Strips. 2. The pulp constituting the base paper is pulp for papermaking.
8 to 70 parts by weight, polyolefin synthetic pulp 2-3
The pearlescent strip according to claim 1, characterized in that it is 0 parts by weight. 3. The pearlescent strip according to claim 1, wherein the pearl pigment is an pearl pigment emitting iris color. 4. The pearl luster strip according to claim 1, wherein the pearl pigment coating layer has a different iris color on both sides. 5. The pearlescent strip according to claim 1, wherein the binder is insoluble in cold water and has a hot water dissolution temperature of 60 to 80 ° C.