JPH01168997A - Paper for developing watermark - Google Patents

Abstract

PURPOSE:To obtain the title paper resistant to yellowing and blotting, capable of developing a watermark by printing at a small lot and low cost and useful for preventing the forgery of merchandise bond, securities, etc., by adding a fluorescent brightener for paper-making use to a printing paper or a coating layer of a paper. CONSTITUTION:A fluorescent brightener is added to a paper for watermark printing or to a coating layer of a paper to obtain the objective paper having stable quality. When the paper is printed with a clear ink, the ink is impregnated into the paper or the coating layer to develop a watermark while keeping the surface of the paper or the coating layer from covering or masking. Light transmits through the transparent ink even if a part of the component constituting the transparent ink is colored to yellow color and, accordingly, the yellow visual appearance is eliminated to give a white paper.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is applicable to paper and paperboard widely used for packaging, printing, writing, etc., as well as securities such as gift certificates, cash certificates such as gift certificates, stock certificates, etc. The present invention relates to a watermark pattern-producing paper for printing a watermark pattern on paper used to prevent forgery in a small loft and at low cost.

(Prior art) Conventionally, a watermark pattern has been applied to paper by using a dandy roll on a wire part during paper making, but small-lot production is difficult, and the watermark pattern cannot be added to the final product as desired. Therefore, recently, a method of creating a watermark pattern using a transparent watermark printing ink whose main ingredients are resin, oil, fat, synthetic rubber, synthetic resin, surfactant, etc. has been developed. However, depending on the composition of watermark printing ink, yellowing of the ink may occur over time, resulting in a significant loss of commercial value.

(The problem that the invention seeks to solve) In addition to the above-mentioned yellowing, the important quality items of watermark printing are
It prevents "bleeding" and clearly expresses the pattern. It is not easy to satisfy all three items at the same time using ink alone.

Especially when printing watermarks using offset printing,
In addition to this, it is necessary to prevent ink misting. Misting is a phenomenon in which ink adhering to the high-speed rotating ink roll of an offset printing machine is dispersed in the air as a mist due to centrifugal force. When misting occurs, it not only contaminates indoor equipment and products, but also deteriorates the working environment and makes it difficult to continue working. In other words, in order to prevent "bleeding" and maintain the delicate watermark pattern, it is best to minimize the use of oil or fat, or use an appropriate amount of resin with good drying properties, but this may cause the resin film to dry. If a resin such as that used in forming ink is used, the ink will harden while remaining on the paper surface and will not penetrate into the paper or the coating layer, so a sufficient watermark pattern will not appear.

Yellowing mainly comes from the oils and fats used. Oil-soluble modified resins, varnishes, and boiling oils are used for Auf Sesoto ink in order to improve its printability, that is, to prevent misting and promote the ink's penetration into paper waste and coating layers, but these are drying oils. It consists mainly of linseed oil, which oxidizes and turns yellow when stored for a short period of time. [In order to prevent bleeding and yellowing, it is better not to use oil or fat, but this will result in insufficient pattern development. Is there any yellowing?

Alternatively, if a small amount of castor oil or epoxidized soybean oil is used, "bleeding" will increase over time, significantly reducing the product value. As described above, the characteristics required for watermark printing are in a contradictory relationship with each other, and it is difficult to satisfy all of these characteristics using ink alone.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems, namely, yellowing caused by resins, oils, and other additives used in watermark printing inks, and fluorescent whitening of the paper and coating layer. It is intended to be prevented by adding an agent. In particular, the present invention is effective for offset inks for watermark printing. Gravure ink has a low ink viscosity, so it is relatively easy for the ink to penetrate inside the paper layer, and there is no misting, so the use of oil-denatured resins and vegetable oils can be kept to a small amount, making it easy to prevent yellowing problems. However, offset ink for watermark printing has a high viscosity, and in order to penetrate the ink into one paper layer and form a good watermark pattern, it is necessary to add varnish made of vegetable oil such as linseed oil, boiled oil, etc. is necessary. Also.

Since the offset ink for watermark printing permeates into one paper layer and improves pattern development, the base resin should be a liquid resin that does not form a resin film even when left at room temperature or heated and dried. Although it is good to use such resins, they penetrate into the paper and give good pattern development.
The bonding force and cohesive force between resin molecules are low, and the stringiness is high, so the centrifugal force of the numerous rolls of the printing machine
A phenomenon called misting occurs in which ink scatters in the air.

To improve misting, it is effective to add resins such as oil-soluble modified phenols and alkyds, varnishes, boiled oil, etc. However, these additions can cause further yellowing due to oxidation over time. Make it bigger. In other words, the countermeasures taken to improve one property required of watermark printing inks have a negative effect on other properties, resulting in the above-mentioned trade-off.

(Means for Solving the Problems) The present invention is thus an attempt to solve problems that are difficult to solve using ink alone, from the perspective of paper. That is, without removing the vegetable oil that causes yellowing from the composition of the ink for watermark printing, fluorescent whitening is added to the paper used for printing or to the material coating layer to improve whiteness, which is generally used for paper manufacturing. As a result of intensive research, it was discovered that adding a chemical agent has a remarkable effect on preventing yellowing of ink.

(Function) As mentioned above, optical brighteners are widely used in paper as agents to improve the paper's apparent whiteness.
It is excited by so-called ultraviolet rays of 00 to 400 millimicrons, absorbs the ultraviolet energy, and develops color as near-ultraviolet light of 400 to 500 millimicrons of visible light, that is, blue-violet light energy. Yellow, which is the opposite color of blue-violet, appears yellow because the reflectance of light with a wavelength of 400 to 500 millimicrons is low, and by supplementing the light energy of this wavelength with a fluorescent whitening agent, Visually, it loses its yellow tinge and appears white.

When watermark printing is performed on the surface of paper waste or coating layer to which a fluorescent brightener has been added, the transparent ink penetrates into the paper or coating layer to create a watermark pattern, but it does not print on the paper or coating like normal ink. Because it does not cover or hide the surface of the layer,
Even if a part of the watermark ink turns yellow, light rays pass through the transparent ink, and the above-mentioned function prevents the watermark from yellowing.

(Example) The present invention will be explained by examples.

Example 1 Paper having the composition shown in Table 1 is made.

Table 1 Softwood bleached kraft pulp 30% Hardwood bleached kraft pulp 70 Sizing agent 1 Pulp solids band 4 8% solution polyacrylamide as ^l 1 Pulp solids optical brightener
0.05 Same as above Note 1 The ratios in the above table are expressed in weight%.

The pulp is beaten in a conventional manner to a freeness of approximately 350c.
, c, (JIS P-8121), then add chemicals below the sizing agent.

Using a Fourdrinier paper machine, 20 g/♂ of a 3% solution of equal amounts of oxidized starch and polyvinyl alcohol was prepared using a size press coater.
A paper having a basis weight of 65 g/m' was obtained by coating.

As a paper for Comparative Example 1, a paper similar to that of Example 1 was made except that the optical brightener was excluded from the formulation in Table 1, and the paper in Table 3. Note 2: Print one character or pattern using offset ink for watermark printing with a composition of 2°, perform a yellowing acceleration deterioration test for a specified number of days in a thermostat at 60°C, and visually check the degree of yellowing. Results of the follow-up survey 1 As shown in Table 3, Example 1, in which a fluorescent brightener was added, did not yellow after 9 weeks, while Comparative Example 1 showed significant yellowing after 4 weeks. Good results were obtained compared to .

Example 2 On the paper that did not contain the fluorescent dye used in Comparative Example 1 of Example 1,
5g solid content per side of coachive paint shown in Table 2.
/♂ coating and use it as a material for Example 2.

As Comparative Example 2, the same composition as shown in Table 2 except for the optical brightener was coated on the paper used in Comparative Example 1, which did not contain the optical brightener, at a solid content of 5 g/male per side.

The letters 4f were printed on the above paper using offset ink for watermark printing in the same manner as in Example 1, and a 60°C yellowing accelerated deterioration test was performed.The results are shown in Table 1. Although no yellowing was observed after the elapse of time, the coated paper of Comparative Example 2, which did not contain a fluorescent whitening agent, turned yellow after 3 weeks.

Table 2 Composition of paint for coated paper Kaolinite clay 45 parts Dry weight Domestic clay 45 Lucium carbonate 10 Sodium polyacrylate 0.2 powder
5 Melamine formaldehyde resin 0.5MBR15 Note I MBR Methyl methacrylate phtadiene latex 2 Solid content concentration 60%! ! ! Viscosity: 1000 cps (Effects of the Invention) As described above, the present invention has been able to prevent yellowing, which significantly impairs the commercial value of watermarked paper, by adding a small amount of fluorescent dye to the paper or paint. It is.

As mentioned above, yellowing can be prevented by excluding the addition of vegetable oil, which is a drying oil, from the ink formulation used, or by using an oil that does not yellow due to oxidation, but if vegetable oil is not available, Non-drying oils, which have poor pattern development and little yellowing, will cause "bleeding" during long-term storage, which will reduce the commercial value of printed materials.

Yellowing occurs due to oxidation of fats and oils or ultraviolet rays, and it seems to be effective, but test results showed no effect at all.

The present invention addresses the characteristics required for watermark printing, which have been difficult to solve with ink alone, such as "bleeding", yellowing, etc.
This method aims to solve problems such as preventing misting and promoting pattern development from the perspective of the paper used for watermark printing.

By implementing the present invention, watermark printing of stable quality can be provided.

Patent applicant: Shintomi Paper Co., Ltd. Table 360℃ yellowing accelerated deterioration test Note 1. The evaluation symbols in the table above are as follows.

No yellowing 0 Slight yellowing Δ Yellowing × 2, Ink formulation polyisoprene used in Table 3 (Kuraprene IR-30)
65% fatty acid aluminum
1.5 extra varnish
5 length oil length alkyd
10 normal paraffin solvent
18.53. The offset ink for watermark printing made from this formulation does not cause streaking at a printing speed of 6000 sheets/hour, has excellent character and pattern expression, and does not cause "bleeding" during long-term storage.

Procedural amendment (voluntary) 1986 2
Month 3 Date l Display of the case 1986 Patent Application No. 326556 2 Name of the invention Sumoyo Hafugenyoushi watermark pattern expression sheet 3 Person making the amendment Relationship to the case Patent applicant Fuji Iriyamase Address 51141 Iriyama, Fuji City, Shizuoka Prefecture Shin Fuji Seishi Name Shintomi Paper Co., Ltd. /1z1.
Toshikazu Kishima (, g/
; f mochi, 2
Representative Director Shi Riwazu 4:r:', ν4 Subject of amendment Ming JIi! Column for detailed explanation of invention of F.

5. Contents of the amendment (1) The detailed description of the invention column in the description is amended as follows.

1) Delete "(the point at which the invention is trying to solve)" on page 4, line 7.

2) Page 8, line 2, ro, 05 Same as above” to “0.5
Corrected to “liquid”.

3) Corrected "dye" in the second line of page 9 to "brightener".

4) Page 9, line 166, 1 Table 2 "Formulation of paint for coated paper" to page 10, "Line 33 rMBR15" 1 Table 2 Formula of paint for coated paper Kaolinite clay 45 parts Dry weight Domestic clay
45 Same as above Lucium carbonate lO Same as above Sodium polyacrylate 0.2 Same as above Starch
5 Same as above Melamine formfludihyde resin 0, 5
Same as above MBR15 Same as above Fluorescent brightener 2 Corrected to "Liquid weight".

5) Page 12, Table 3. “Dye” in the notes column of Example 1 was changed to “
Corrected to "brightener".

6) Page 12, note 20. 2nd line “(...rR-30
)J is corrected to r (・t, rR-30)J.

7) Page 12, Note 3. , Correct "...stinging" in the second line to "...misting".

Claims (1)

[Claims] Addition of optical brightener to the paper layer or coating layer for printing, coating, and penetrating transparent ink made of resin, oil, fat, synthetic rubber, synthetic resin, surfactant, etc. to create a watermark pattern. Paper with a watermark pattern that prevents yellowing caused by ink composition materials.