KR20040012361A - Ink-Jet Ink Composition Include Extracted Tannin from Persimmon - Google Patents

Abstract

PURPOSE: An inkjet-printer ink composition containing tannin extracted from persimmon which can substitute most of imported conventional tannin, thereby being able to reduce the production cost and secure a stable supply source domestically is provided. CONSTITUTION: The inkjet-printer ink composition containing various components containing deionized water, organic solvent which is soluble in water or miscible with water, coloring agent, tannin, and the like, comprises tannin component extracted from persimmon by means of a solvent extraction method. Specifically, the tannin component extracted from persimmon is gallic acid, ellagic acid, and catechin.

Description

Ink-Jet Ink Composition Include Extracted Tannin from Persimmon}

The present invention relates to tannins contained in inkjet ink compositions, and more particularly, to inkjet ink compositions in which tannins extracted from persimmons are used to smoothly supply and receive tannins contained in inkjet inks.

As is well known, inks constructed in a wide variety of ways with respect to ink for ink jet recording have been reported.

In particular, in recent years, detailed research and development has been carried out by accessing various research fields such as composition and physical properties so that excellent recording can be made on plain paper such as copy paper, recording paper, notebook or letter paper commonly used in offices. It is done.

That is, ink jet printer inks include water-soluble inks in which water-soluble pigments are dissolved in water and pigment-dispersible inks prepared by dispersing water-insoluble pigments in water. In the case of water-soluble inks, dyes as pigments have water-soluble substituents in the molecular structure. Therefore, it is difficult to improve water resistance or light resistance inherently.

Therefore, in order to improve water resistance and light resistance after printing, a pigment dispersion method for producing an ink by dispersing a pigment having good water resistance and light resistance in water has attracted attention.

As the ink manufacturing method using the pigment dispersion method, hundreds of inkjet printers have been applied since 1984 by Canon Corporation (US Pat. No. 4,597,794) and Dupont Corporation (USP 5026427) in 1988. Patents relating to methods and compositions for preparing inks have been filed.

Commercially, since Hewlett-Packard Co., Ltd. was first applied to HP Deskjet since 1996, it has been applied to DeskJet by US company Lexmark, etc., and is increasing in Japanese Canon. .

However, in the case of pigment-dispersible inks, since pigments are inherently water insoluble, a problem arises in that the pigment concentrations may or may not be settled in the cartridge over time even if the pigment particles do not sink.

That is, the settling of the pigment particles causes a problem of clogging of the nozzle during printing, and the difference in concentration of the pigments hinders the uniformity of the printing quality.

In the inkjet inks classified as described above, the ink for an inkjet printer is generally referred to as a dye type ink composed of a water-soluble medium and a dye.

However, this dye-type ink has the disadvantage that the water-soluble dye has inherent properties, namely, water and heat resistance, as described above.

In order to solve this problem, a method of producing an ink using a pigment instead of a dye has been proposed.

On the other hand, inks for inkjet printers typically require the following physical properties.

First of all, long-term storage should not change the physical properties and there should be no clogging of the nozzle.

In addition, high-resolution image output should be possible and should have basic physical properties such as water resistance and light resistance.

In particular, pigmented inks require high storage stability. In other words, the pigment dispersion should be maintained even in long-term storage, and nozzle clogging should not occur even when a new printout is performed for a long period of time during printing.

Ink compositions used in inkjet printers requiring such physical properties generally include various compositions such as deionized water, water soluble or organic solvents that can be mixed with water, and colorants, wherein soluble dyes are used as colorants. have.

However, inks containing soluble dyes have many problems such as poor water-sticking, poor light-sticking, solvent evaporation and solidification of the flushing channel resulting in changes in the solubility of the dye, crystallization of the dye, ink Problems such as poor print quality, poor thermal stability, chemical instability, and easy oxidation, including smearing and feathering of ink (smearing ink into feathers).

Many of these problems can be overcome by replacing the water soluble dye used in the ink formulation with an insoluble pigment.

That is, pigments have superior properties when compared to dyes, especially in terms of water-stick, light-fix, thermal stability, oxidative stability, and compatibility with coated / treated and flat paper.

However, new problems arise because the pigments are insoluble in the ink composition and therefore must be included in a dispersed state.

The stability of the ink is very important in two respects, keeping the properties homogeneous and ensuring that the pigment does not solidify the inkjet when the use is suspended.

Of course, the ideal in terms of stability and reasonable cost would be to use the minimum amount of pigment required for the ink composition.

However, reducing the amount of pigment in the ink composition can cause poor optical density of the image.

Furthermore, due to the equilibrium of the composition required to ensure the required stability, the composition has a suitable viscosity for use in an inkjet printer, as well as good printing properties such as good water-stick, light-stick, and application to paper. It is also important to ensure that it has minimized operation and feathering when done.

It has been very difficult to develop ink formulations that optimize all these properties. The general approach has been to adjust the dispersant and solvent system of the ink composition in an attempt to balance and optimize these sometimes competing properties.

In such an inkjet ink composition requiring various compositions, a tannin component (hereinafter referred to as tannin), which is a water-soluble polymer, is contained in the ink composition.

Here, the tannin is a polyhydric phenol compound which forms gallic acid by hydrolysis and is widely contained in natural plants.

In general, tannins are classified into two types, hydrolysis type and condensation type, and since both are natural compounds, many tannins having different structures exist.

As described above, tannin is a compound widely contained in natural plants, and thus it can be easily assumed that tannin is partially different in chemical structure.

That is, the tannins are a large group of water-soluble complex organic compounds naturally present in the leaves, twigs, bark, wood and fruits of many plants and are generally obtained by extraction from plants.

The composition and structure of the tannin will vary depending on the source and extraction method, but the general empirical formula is represented by C ₇₆ H ₅₂ O ₄₆ .

Such tannins are industrially used in various aspects, and as described above, they are used for inks, medical hemostatic agents, tanning agents for leathers, and colorants for dyes.

At this time, the polyhydric phenol compound having a dyeing effect and a tanning effect on leather is called "synthetic tannin".

And tannins are well soluble in water and lower alcohols, and thus can be used in the form of high concentration solutions.

Tannin having such characteristics is used as a composition of the ink as described above, in the present case, in our country, tannin used as an ink composition is extracted and used in the Indonesian alder fruit.

However, in the case of extracting tannin from the Indonesia alder fruit and using it as an ink composition as described above, the manufacturing cost of ink may increase due to the supply and demand imbalance due to the import instability of the alder fruit and the price increase due to the import There is concern and we can expect a shortage of products.

In this regard, the present invention has been made as one of the alternatives to the above problems, and the present invention focuses on the fact that tannin is a naturally occurring water-soluble complex organic compound extracted from a plant and contains a large amount of tannin in our country. By extracting tannin from persimmon, a fruit of persimmon cultivated a lot, and using it as an ink composition, tannin extracted from persimmon can be used to lower the cost of ink production because it can supply raw materials smoothly while bringing import substitution effect. The object is to provide an inkjet ink composition.

The present invention for achieving the above object is achieved by extracting, separating and purifying the tannin and polyphenol components contained in persimmon by a solvent extraction method, and then using them as ink compositions.

Here, in order to extract tannin for use in the ink composition according to the invention from the persimmon tannin component and polyphenol components of the persimmon extraction and separation using an organic solvent and water, purified by column chromatography, HPLC, ₁ The process of analyzing the structure by performing H-NMR, ₁₃ C-NMR and molecular weight spectrum will be described.

At this time, persimmons used in the present invention were collected around September, TLC (Thin Layer Chromatography) was used Kieselgel 60F ₂₅₄ plate (Merck).

As the mobile phase, n-BuOH: acetic acid: H2O (4: 1: 1), ethyl acetate: hexane (1: 1), methylene chloride: methanol MeOH (9: 1), methylene chloride: methanol (3: 1) ), Chloroform: Methanol (3: 1), Chloroform: Methanol (9: 1), Chloroform: Methanol (20: 1), Chroform: Methanol (2: 1), Chroform: Methanol (4: 1) and the like were used.

Detection of developed components was performed using 10% Phosphomolybdic acid-EtOH and 1% FeCl ₃ -EtOH reagents, and in the case of Phosphomolybdic acid-EtOH reagents. The TLC plate was immersed in the detection solution, taken out, and baked in an oven. In the case of 1% FeCl ₃ -EtOH reagent, the TLC plate was sprayed and dried.

HPLC was performed using Dionex-system and analyzed by gradient conditions.

Each peak isolated was identified by comparison with the retention time of the standard, and the analysis conditions were as follows.

HPLC analysis conditions

Analyzer: Dionex Dual Pump DX-500

Detector: Dionex UV Detector

Column: Cosmosil packed column (4.6 × 150 ㎜, 5ph Type)

μ-Bondapak C18 reverse-phase column (4.6 × 150 mm)

Mobile phase: Water (0.025% Phosphoric acid),

Methanol (0.025% Phosphoric acid)

Flow rate: 1 ml / min

Record system: Shimadzu integrator recorder (C-R7A)

Resins used for Gel Filtration Chromatography were Sephadex LH-20 and MCI-gel CHP-20P. The eluted mobile phases were distilled water and methanol.

Example 1 Extraction, Separation, Purification and Structural Analysis of Tannin and Polyphenol Components of Persimmon

Step 1: Extract and Separate

Persimmon used in this step (Diospyros kaki Thunberg) was collected in September before maturation was confirmed to taste directly, and stored in -70 ℃ freezer was used.

After cutting 5 kg of persimmons, the extracts were repeatedly extracted twice at room temperature for 3 weeks with 70% acetone and filtered through filter paper.

At this time, since the extract of persimmon contains a large amount of sugar (sugar), it took a lot of time to filter the high viscosity.

Acetone was removed under reduced pressure and the crude extracts were examined by TLC (n-BuOH: Acetic acid: H ₂ O = 4: 1: 1, Ethyl acetate: Hexane = 1: 1).

The aqueous layer was placed in a round bottom flask to remove all of the water to obtain a solid substance, which was transformed into an insoluble substance that did not dissolve in any solvent, so that no more water could be blown out. It was taken in and extracted with organic solvent.

Second Step: Purification by Column Chromatography

In this step, the weight of the organic solvent extracted from persimmon was measured, and then column chromatography was performed.

The Sehpadex LH-20 resin to be filled in the column was previously swelled in MeOH solvent for 1 day, and then swelled in the column, and the methanol solvent was continued to flow.

The sample was completely dissolved in a small amount of methanol, filtered through filter paper and then loaded.

After this loading, the mixture was eluted under isocratic conditions using methanol solvent.

Then, after confirming the components of the eluted solution by TLC (Chloroform: MeOH = 3: 1, Chloroform: MeOH = 20: 1), and collected by fractions to remove all the solvent under reduced pressure, the weight was measured.

Sephadex LH-20 was swelled in MeOH for one day in order to perform column chromatography with gradient, then packed into a column under concentration gradient (100% MeOH → 80% MeOH → 60% MeOH → 40% MeOH → 20% MeOH → distilled water).

In addition, the fractions separated under the same conditions were dissolved in methanol again, placed in a column, and eluted under a concentration gradient condition (distilled water → 20% MeOH → 40% MeOH → 60% MeOH → 80% MeOH → 100% MeOH).

After each fraction was collected by an automatic fractional collector, the separation of each component was confirmed by TLC (Chloroform: MeOH = 3: 1, Chloroform: MeOH = 20: 1).

If spot separation was insufficient by TLC, column chromatography was repeated using MCI-gel CHP-20P under a single solvent condition and a gradient condition.

Step 3: HPLC Analysis

The HPLC analyzer was a DIONEX system and the detector chose 254 nm because most tannins have aromatic rings.

The solvent condition of the mobile phase was a concentration gradient, and the sample to be separated was completely dissolved in methanol and injected.

The concentration gradient conditions of the mobile phase solvent were set in the direction of increasing the methanol containing 0.025% H3PO4 to 64% from the initial concentration of 10% to 18 minutes using the μ-Bondapak C18 reverse-phase column. The conditions were set in the direction of increasing to 100% by minute and decreasing to the initial concentration of 10% again by 30 minutes.

When using a Cosmosil packed column, methanol containing 0.025% H ₃ PO ₄ was increased from 10% to 18% to 64%, up to 22 minutes to 100% and then to 27 minutes Only methanol which was the same solvent was sent out.

When analyzing the aqueous phase of the persimmon mobile phase conditions were carried out by applying a μ-Bondapak C ₁₈ reverse phase column.

Cosmosil packed column conditions were analyzed by HPLC for the analysis of the samples fractionated with organic solvent and the organic solvent extract separation of persimmon after column chromatography treatment.

As a result, it was found that the jutannin component of persimmon was gallic acid.

In particular, a large amount of gallic acid was found in the ethyl acetate layer among the various organic solvents of the second step, and also a large amount of moline was also found.

Comparative analysis of the C ₁₈ -reverse HPLC with the standard resulted in 7.6 g of gallic acid and 4.5 g of moline per 5 kg persimmon.

This is summarized in Table 1. Therefore, the tannin component and the polyphenol component of the persimmons extracted with the organic solvent in the first step were confirmed. The yields of the fractions obtained by sequentially sequencing with ether, Ether, EtOAc, and BuOH are summarized, which shows the amount of fractions fractionated per liter of aqueous layer remaining after acetone was blown off.

That is, among the fractions, the ethyl acetate layer contained a large amount of tannic gallic acid, while the polyphenol compound contained a small amount.

In addition, in the ether fraction, although a small amount, many polyphenol compounds, such as flavonol, morphine, naringenin, and quercetin, and tannin, such as gallic acid, ellagic acid, and catechin, were detected.

Table 1

The amount of tannins and other polyphenol compounds in persimmons (g / 500g)

Garlic acid 7.60 g Maureen 4.50 g Flavonol 3.72g Naringenin 2.84 g Ellagic acid 2.44 g Quercetin 2.40 g Catechin 1.12 g

Table 2

Organic Solvent Extraction Yield of Persimmon

Sample Yield (g / L) PET ether ether fraction 0.6g Ether fraction 1.6 g Ethyl acetate fraction 3.0 g Butanol fraction 1.0 g

Step 4: Structural Analysis

Gallic acid among the components analyzed by HPLC was separated into single components by repeated gel filtration chromatography and recrystallization, and its structure was confirmed by IR spectrum, ₁ H-NMR, and ₁₃ C-NMR. .

Experimental results, gallic acid as colorless needle-like crystals showed a blue color in test FeCl _3, from 3496cm _-1 in the IR spectrum was found phenol sanim show the absorption band due to OH groups in the COO, 1668cm _{-1, 1} H-NMR spectrum Shows a singlet signal by galloyl corresponding to hydrogen integration value of 2H at δ7.05 ppm. In ₁₃ C-NMR spectrum, C-3 at δ110.3, C-4 at δ146.4, C-4, δ170. Carbonyl signal by COOH group at 4 was observed.

As described above, according to the present invention, since persimmon contains a large amount of tannin components, it will be said that it has a sufficient value as a resource for securing tannin components included in the ink composition.

Therefore, if tannin component is extracted from persimmon, a perennial or cultivated persimmon fruit grown in Korea, and used in ink production, it is possible to replace the import of Indonesian alder fruit, which is imported for extracting tannin component. And it is possible to smoothly secure the tannin component required for ink manufacturing has the effect of lowering the ink manufacturing cost through such a smooth supply of raw materials.

Claims (2)

In inkjet ink compositions comprising a variety of compositions, such as organic solvents, colorants and tannin components, which are typically deionized water, water soluble or mixed with water, An inkjet ink composition comprising tannin extracted from persimmon, wherein the tannin component is extracted from a persimmon which is persimmon fruit through a solvent extraction method and used as an ink composition. The method of claim 1, Tannin component extracted from the persimmon is an inkjet ink composition comprising tannin extracted from the persimmon, characterized in that the gallic acid, ellagic acid, catechin.