KR100560240B1 - Method for Manufacturing Highly Reinforced Anti-soiling Banknote Paper - Google Patents

Abstract

The present invention relates to a method for manufacturing a banknote paper with enhanced stain resistance, and to a method for enhancing paper contamination resistance in a manufacturing process of a banknote paper. The method of manufacturing a banknote paper according to the present invention is characterized in that when the paper is manufactured, the contamination resistance of the paper is enhanced by adding the stain resistant surface treatment agents of the first and second steps.

Banknote paper, stain resistance, thickener, water and oil repellent, first and second surface treatment solution

Description

Method for manufacturing highly resistant banknote paper {Method for Manufacturing Highly Reinforced Anti-soiling Banknote Paper}

The present invention relates to a method of manufacturing a banknote paper with enhanced stain resistance, and more particularly, has a surface treatment process divided into a first stage surface treatment and a two stage surface treatment, and a thickener is applied during the two stage surface treatment. The present invention relates to a method of manufacturing a banknote paper with enhanced stain resistance that can effectively increase the stain resistance of paper by using a functional additive effective for expression of stain resistance at the first and / or second stage surface treatment.

In general, as a raw material for manufacturing banknote paper, non-wood pulp such as cotton fiber (seaweed noodles, imported cotton pulp), flax, hemp, jute fiber, rice straw pulp, and abaca is used as the main material. Chemicals that prevent paper from being easily soaked in water), dry strength enhancers (chemicals that maintain strength when paper is dry), wet strength enhancers (chemicals that maintain constant strength when paper is wet), and other specialty A chemical used for the purpose is added. The chemicals added for this purpose are added in a dilute state of 0.2 to 2% by weight, preferably 0.1 to 1% by weight, respectively, when preparing the base paper, and then considerably dehydrated, pressed and dried. This results in the loss of many drugs.

Therefore, in order to maintain the strength of paper and the performance of special chemicals, the method of treating chemicals directly on the already formed paper is appropriate. Therefore, most paper mills perform surface treatment (or surface sizing) or coating treatment.

Conventionally, gelatin or polyvinyl alcohol or the like has been used as a surface treatment agent of the produced original paper in order to improve distribution durability and general physical properties when manufacturing banknote paper.

Gelatin is a kind of animal protein extracted from animal bones and the like, and is used in the manufacture of paper for special purposes to improve the durability of paper. In other words, it is used as a surface treatment agent when manufacturing papers requiring distribution durability, such as banknote paper, but when the surface treatment is made with gelatin, the paper is very thin and the quality is degraded. There is a risk of this happening. In addition, the surface treatment with gelatin requires a step of curing the gelatin with formaldehyde, etc. At this time, formaldehyde gas generated from the chemical is a very dangerous carcinogen with irritating odor, which brings a lot of risks to the safety of the operator. The trend is to avoid gelatin surface treatment.

Polyvinyl alcohol, which is used as a substitute for gelatin, is a low-toxic polymer, which is less than gelatin for surface treatment, but has a disadvantage in that paper is thinner, printability is lower, and distribution durability is lower than that in gelatin treatment.

As described above, conventional surface treatment agents have been used for the purpose of improving the strength and surface properties of paper, but banknote papers require stain resistance in addition to the strength characteristics for long-term distribution.

According to data released by central banks, the biggest cause of the collection and disposal of banknotes in circulation is pollution. The contamination of banknotes, which have a significant effect on the life of banknotes, is because banknote paper is a porous material, and its surface roughness is weaker than film or metal, and thus the resistance to contamination is weak.

In order to solve this problem, in Switzerland and the Netherlands, varnish is applied to the surface of banknotes to improve the shelf life by 10 to 30%. Plastic banknotes such as Australian polymer banknotes have a four times longer life than paper banknotes.

Recently, some suppliers have developed durable papers by coating stain-resistant materials on both sides of the paper in lieu of polymer banknotes.

International Publication No. 2000-00679 discloses a security paper that improves the stain resistance of a banknote paper by coating a surface of the paper with an acrylate or a polymer having a high acrylate content. In the patent, the coating on one side of the security paper, the coating is a method of improving the fouling resistance of the banknote by coating a composition comprising a binder made of acrylate or a polymer of high acrylate content without filler. However, this method involves the problem of adding additional equipment such as coating equipment to the existing security paper manufacturing process.

Accordingly, an object of the present invention is to solve the problems of the prior art, and to improve the fouling resistance without adding additional coating equipment and without deteriorating the physical properties of important banknote papers such as the paper's theft and tensile strength. It is to provide a method of manufacturing this enhanced banknote paper.

In order to achieve the above object, a method of manufacturing a pollution-resistant reinforcement banknote paper according to the present invention may be obtained by hardening and refining non-wood pulp to obtain a pulp having less microfiber, and then adding an additive containing a wet paper strength enhancer. Providing a; Impregnating the base paper with a polyvinyl alcohol aqueous solution of 3 to 4% by weight, which is a first surface treatment solution, to surface-treat and passing the press roll press to remove excess aqueous solution; And impregnating the raw paper, which has passed the removing step, into a second surface treatment solution and subjecting it to a surface treatment and drying and humidity treatment by passing the press roll press.

Hereinafter, the present invention will be described in more detail.

As described above, the manufacturing method of the banknote paper according to the present invention is characterized in that it comprises a surface treatment step consisting of two steps to improve the stain resistance.

First, in order to manufacture a banknote paper according to the present invention, by beating and refining the non-wood pulp to obtain a pulp with less microfiber, an additive containing a wet paper strength enhancer is added to provide a base paper. For a method of manufacturing such paper, for example, reference may be made to Korean Patent Application No. 2001-88765 filed with the present applicant.

Examples of the non-wood pulp container include cotton fiber (cooked cotton, imported cotton pulp), flax, hemp, jute fiber, rice straw pulp, abaca and the like. By beating and refining such non-wood pulp to obtain a stock, it is possible to participate in a small amount of additives such as inorganic fillers. In addition, 0.1 to 1.5% by weight of a wet strength enhancer is added and reacted to the reactants, followed by dehydration, pressing, and drying to obtain a base paper.

The base paper thus obtained was impregnated in an aqueous solution of 3 to 4% by weight of polyvinyl alcohol, which is the first surface treatment solution, to be surface treated, and passed through a compression roll press to remove excess first surface treatment solution. The concentration of the polyvinyl alcohol aqueous solution indicates the content of polyvinyl alcohol with respect to water by weight. In addition, the conditions for preparing the aqueous solution may be carried out at 90 ~ 100 ℃. It is possible to further add a small amount of additives such as urea, gelatin, and starch to the polyvinyl alcohol aqueous solution.

Subsequently, the base paper having passed through the removal step is impregnated into the second surface treatment solution and subjected to a surface treatment, and passed through a compression roll press to dry at 50 to 120 ° C, preferably 70 to 120 ° C. In addition, the second surface treatment solution may be prepared at 90 to 100 ° C.

The second surface treatment solution contains 1 to 10% by weight glycerin, 1 to 5% by weight borax, 1 to 10% by weight thickener and the remaining water, and the thickener is 1 to 3% by weight carboxymethyl cellulose and / or 1 to 10% by weight of polyurethane resin. When the content of the carboxymethyl cellulose and / or the polyurethane resin used as the thickener is included in the above range, it is possible to give the optimum semi-coating effect to improve the paper's stain resistance. In addition, examples of the polyurethane resin include SNOTEX CHT 200 and 300 of Daeyoung Chemical.

In addition, when the content of the glycerin and borax is out of the above range, there may be a problem in that the physical properties such as theft resistance decrease or printability deteriorates.

In the present invention, in order to maximize the degree of contamination resistance of the paper, 0.5 to 2% by weight of the water and oil repellent agent may be further added in the first and second surface treatment steps, and the water and oil repellent agent may be a silicone compound or a fluorine compound. to be.

That is, as a water- and oil-repellent agent widely used to improve pollution resistance, the silicone-based water-repellent agent has excellent hydrophobicity but weak oil resistance, but the fluorine-based compound has strong plasticity against the permeability of water and oil.

The silicone compound may be a compound in which a functional group such as methyl group, phenyl group, vinyl group and alkyl group is substituted in the siloxane chain as a skeleton, and these functional groups may be converted into other functional groups by various chemical reactions. These silicone-based compounds may exhibit different physical properties in various forms depending on the chain length and degree of crosslinking, impart soft touch and water repellency, and do not deteriorate whiteness even after treatment.

Fluorine-based compounds generally have a structure in which part or all of hydrogen (H) in the molecular structure of aliphatic hydrocarbons such as polyethylene and polypropylene are substituted with fluorine (F), and have characteristics such as wear resistance, chemical resistance, and stain resistance. Has

As described above, according to the method according to the present invention, unlike the prior art, by performing a two-stage surface treatment of a process consisting of a one-stage surface treatment and a two-stage surface treatment without additional coating equipment, by applying a thickener in two stages By giving a semi-coating effect, it is possible to improve the contamination resistance of the paper.

The present invention will be described in more detail with reference to the following examples and comparative examples, but the scope of the present invention is not limited thereto.

Evaluation of the pollution resistance of the paper produced according to the present invention is largely by the wet and dry method, the wet method averages the difference between the whitemess and yellownes before and after the pollution, in the dry method the whiteness after contamination To assess the degree of contamination. In the present invention, the degree of contamination by the dry method was measured.

Preparation Example 1

The paper was prepared by beating the bleached cotton fibers with a calcination up to 28 ° SR at a concentration of 3.5% by weight and then refining them in a refiner to 55 ° SR. 6.5 wt% of inorganic filler and 0.5 wt% of wet strength enhancer (polyamideamine-epichlorohydrin (PAE), kymene 557H, manufactured by Hercules) were added to the dry weight of the pulp to form a paper. The wetland was prepared while diluting to 0.2% by weight to continuously introduce into the cylinder vat. The wetland was compressed and dried under 100 ° C. conditions to produce raw paper.

Examples 1-12

4 wt% aqueous polyvinyl alcohol solution (PVA), 0.5 wt% wet strength enhancer (polyamideamine-epichlorohydrin (PAE), kymene 557H, manufactured by Hercules) and urea dissolved at a temperature of 95 ° C. according to Table 1 below. To prepare a first surface treatment solution by mixing.

In addition, glycerin, borax, carboxymethyl cellulose (CMC), urethane-based thickeners and fluorine compounds were prepared in accordance with Table 1 below to prepare a second surface treatment solution with the composition and content shown in Table 1 below.

The base paper prepared in Preparation Example 1 was impregnated into the surface treatment solution of the first step, and then passed through a pressing roll press to remove excess surface treatment agent. Thereafter, the base paper was immersed in the second step surface treatment agent, and the excess was removed in the same manner as in the first step, followed by drying to prepare a surface treated banknote paper.

Comparative Example 1

Table 1 was prepared in the same manner as in Example 1, except that the thickener and water- and oil-repellent agent were not added, to prepare a banknote paper.

1st step surface treatment (wt%) 2 stage surface treatment (% by weight) PVA PAE Element additive borax glycerin additive additive Comparative Example 1 4 0.5 2.5 - 2.5 3 - - Example 1 4 0.5 2.5 - 2.5 3 SNO ^{* 3} 5 - Example 2 4 0.5 2.5 - 2.5 3 CMC ^{* 4} 2 - Example 3 4 0.5 2.5 - 2.5 3 CMC 4 - Example 4 4 0.5 2.5 - 2.5 3 CMC 4 SNO One Example 5 4 0.5 2.5 - 2.5 3 CMC 4 AG One Example 6 4 0.5 2.5 AG ^{* 1} One 2.5 3 CMC 4 AG One Example 7 4 0.5 2.5 F420 ^{* 2} One 2.5 3 CMC 4 AG One Example 8 4 0.5 2.5 - 2.5 3 CMC One AG 0.5 Example 9 4 0.5 2.5 F420 One 2.5 3 CMC One AG 0.5 Example 10 4 0.5 2.5 F420 One 5 3 CMC One AG 0.5 Example 11 4 0.5 2.5 F420 One 2.5 3 CMC One SNO One Example 12 4 0.5 2.5 F420 One 2.5 3 CMC 2 AG 0.5

^* 1: Fluorine-based water and oil repellent, Asahigard, AG 7605

^* 2: Fluorine-based water and oil repellent, Acechem, F420

^* 3: Polyurethane thickener, Daeyoung Chem, SNOTEX CHT-200

^* 4: carboxymethyl cellulose, KOJE, KCA 8060

Test Example

The banknote paper prepared in Examples 1 to 7 and Comparative Example 1 described above was subjected to a humidity treatment for 24 hours at 20 ° C. and 65%, and then measured for tensile strength and tear resistance based on KS M 7014 and KS M 7068. Based on the dry stain resistance measurement method used in Thailand, the stain resistance of the paper was measured and shown in Table 2 below. The greater the value of the fouling resistance, the higher the fouling resistance.

Rosette, km Internal Theft, Time (MD) Pollution degree dry Wetting Comparative Example 1 8.5 3.0 4651 22.19 Example 1 8.9 2.9 4421 39.36 Example 2 9.7 3.1 3945 33.84 Example 3 9.5 3.2 4235 62.28 Example 4 9.6 3.4 4766 65.49 Example 5 9.9 3.1 4412 67.92 Example 6 9.2 3.2 4124 66.74 Example 7 9.2 3.2 5905 61.91 Example 8 9.8 2.8 4479 45.50 Example 9 10.0 2.7 3732 51.79 Example 10 10.2 2.9 3285 47.10 Example 11 9.9 2.8 4369 60.71 Example 12 10.6 3.2 4473 72.45

As can be seen from Table 2, compared with the case where the additive for improving the stain resistance is not applied and the surface treatment of only one step, the stain resistance was increased in the embodiment according to the present invention. When water- and oil-repellent agent is added together, the stain resistance was maximized. In addition, despite the increase in contamination resistance, the physical properties of the paper were not affected or rather increased.

As can be seen from the above examples and comparative examples, the manufacturing method according to the present invention is carried out a surface treatment process consisting of a one-step surface treatment and a two-step surface treatment, without further investment of additional equipment, and also two steps By applying a thickening agent to the surface treatment, it is possible to treat the paper by giving a semi-coating effect, thereby improving the contamination resistance of the paper without deteriorating the physical properties of the paper. In addition, a small amount of water- and oil-repellent agent can be applied to the first or second surface treatment to maximize the paper's contamination resistance.

Claims (5)

Hardening and refining the non-wood pulp to obtain pulp with less microfiber, and then adding an additive including a wet strength enhancer to provide a base paper; Impregnating the base paper with a polyvinyl alcohol aqueous solution of 3 to 4% by weight, which is a first surface treatment solution, to surface-treat and passing the press roll press to remove excess aqueous solution; And Impregnating the raw paper, which has passed the removing step, into a second surface treatment solution and subjecting it to a surface treatment, and drying and humidifying by passing the press roll press; The manufacturing method of the banknote paper with enhanced pollution resistance comprising a. According to claim 1, wherein the second surface treatment solution contains 1 to 10% by weight of glycerin, 1 to 5% by weight of borax, 1 to 10% by weight of thickener and the remaining water resistant banknotes characterized in that Method of manufacturing paper. The method according to claim 2, wherein the thickener is 1-3 wt% of carboxymethyl cellulose, 1-10 wt% of polyurethane resin, or a mixture thereof. The method of claim 1, further comprising adding 0.5 to 2% by weight of a water and oil repellent agent in the first and second surface treatment steps. The method of claim 4, wherein the water / oil repellent agent is a silicon compound or a fluorine compound.