KR19990079152A - Record keeping ink composition and its manufacturing method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a recording storage ink composition for writing and stamping inks which does not cause discoloration or fading even after long term storage.

According to the present invention, the hydrogen ion concentration index is 7.0 or higher, light resistance is higher than grade 4 (Gray Scale), and 30-50 parts by weight of distilled water having excellent heat resistance, water resistance, oil resistance, alcohol resistance, acid resistance, alkali resistance and bleaching resistance, ink absorption 10-20 parts by weight of accelerator, 3-7 parts by weight of water-soluble binder, 3-8 parts by weight of anti-corrosive agent, 5-15 parts by weight of fibrin bond aid, 10-20 parts by weight of dye, 3-7 parts by weight of dye binder and viscosity modifier 3 There is provided a recording composition ink composition comprising -7 parts by weight.

The new ink composition for recording preservation according to the present invention is excellent in light resistance, heat resistance, water resistance, oil resistance, alcohol resistance, acid resistance, alkali resistance, bleaching resistance, and the like. It is also applicable to counterfeit prevention by discoloration or fading of ink like securities.

Description

Record keeping ink composition and its manufacturing method

The present invention relates to a recording composition ink composition. More particularly, the present invention relates to a recording storage ink composition which does not cause discoloration or fading even after long term storage.

Currently used writing and stamping ink can be roughly divided into oil-based ink using an organic solvent and water-soluble ink using water. Oil-based ink is not easily erased in water and has excellent merit of writing color. However, the organic solvents used are relatively harmful to human body and are not satisfactory.

On the other hand, the water-soluble ink is relatively harmless to the human body, but has the advantage of low production cost, but has a disadvantage inferior to oil-based ink in terms of quality, such as water resistance, weather resistance.

In particular, the preservation of the ink is an important factor in the important documents that need to be preserved for a long time, and when the recording is discolored or faded, a serious problem arises.

Accordingly, it is an object of the present invention to provide a recording preservation ink composition which is not only discolored or faded even after long-term preservation after recording, but also made harmless to the human body.

The inventor has already filed a patent as "Invariant Ink Composition", which is the basis of the inventors' ink-keeping ink composition, and is registered in Korean Patent No. 18229.

The "Invariant Ink Composition" of Korean Patent No. 18229 is made of insoluble dyes by adding dextrin to dyes in order to solve the defects of the conventional modified ink so that the ink molecules are chemically bonded by dye molecules and fiber molecules of the transfer body. .

Furthermore, in order to impart light resistance and invariability, acid ink was added to benzoic acid to form a metal salt of monobasic acid, thereby making a constant ink having excellent light resistance and invariability.

The present invention is to provide a constant ink composition that satisfies the recording storage properties such as light resistance, heat resistance, water resistance, oil resistance, alcohol resistance, acid resistance, alkali resistance and bleaching resistance as well as invariance which is an advantage of the prior art.

According to the present invention, 30-50 parts by weight of distilled water, 10-20 parts by weight of ink absorption accelerator, 3-7 parts by weight of water-soluble binder, 3-8 parts by weight of anti-corrosive agent, 5-15 parts by weight of fibrin bond aid, 10-20 parts by weight of dye It provides a water-soluble ink composition for recording preservation comprising 3-7 parts by weight of the dye binder and 3-7 parts by weight of the viscosity modifier.

More specifically, 30-50 parts by weight of distilled water according to the present invention; 10-30 parts by weight of an ink absorption accelerator selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and glycerin; 3-7 parts by weight of a dye binder selected from the group consisting of amylodextrin, erythrodextrin, acrodextrin and malodextrin; 3-15 parts by weight of a viscosity modifier selected from the group consisting of ethyl alcohol, methyl alcohol and isopropyl alcohol; 3-8 parts by weight of at least one anti-corruption agent selected from the group consisting of phenol, salicylic acid and tannic acid; 3-7 parts by weight of a water-soluble binder selected from the group consisting of shellac, water-soluble acrylic resin, water-soluble urethane resin, water-soluble epoxy resin and modified resin thereof; There is provided an ink composition for recording preservation, which comprises 5-15 parts by weight of a cellulose-bonding aid comprising cellulose ester and benzoic acid and 10-20 parts by weight of a dye.

In addition, according to the present invention 1) the step of heating 10-30 parts by weight of alcohol selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol at least 50 ℃;

2) dispersing 10-20 parts by weight of the dye and 3-7 parts by weight of dextrin selected from the group consisting of amylodextrin, erythrodextrin, acrodextrin and malodextrin to the alcohol;

3) increasing the temperature of 30-50 parts by weight or more at 60 ° C. apart from steps 1) and 2);

4) adding 3-8 parts by weight of at least one acid selected from the group consisting of phenol, salicylic acid and tannic acid to the distilled water of step 3) to dissolve and slowly cool to room temperature;

5) mixing the dispersion prepared in step 2) and the solution prepared in step 4);

6) 3-7 parts by weight of the resin selected from the group consisting of shellac, water-soluble acrylic resin, water-soluble urethane resin, water-soluble epoxy resin and modified resin thereof and 5-15 parts by weight of cellulose ester are added to the mixture prepared in step 5). To 50 ° C. or higher; And

7) There is provided a method for preparing a recording composition ink by cooling the reaction product of step 6) to room temperature and adding 3-15 parts by weight of alcohol selected from the group consisting of ethyl alcohol, methyl alcohol and isopropyl alcohol.

The dispersion of step 2) is preferably prepared by reacting the ink absorption promoter at a temperature of 100 ° C. or more for a predetermined time and then cooling the mixture, followed by filling with a dye and a dye binder and dispersing the same using a sand mill or a ball mill.

The solution of step 4) is preferably prepared by dissolving a fiber binding aid in distilled water, and then dissolving the solution in step 2) by mixing a dispersion solution with a water-soluble binder to solve ink fading and reacting at a predetermined time and a predetermined temperature. . A water-soluble ink composition for recording preservation of the present invention is prepared by adding an appropriate amount of a viscosity control agent for the purpose of viscosity adjustment to improve writing feeling when using an ink composition and an anti-corruption agent for preventing corruption during long-term storage.

The ink absorption accelerator used in the present invention is preferably selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and glycerin. The composition ratio of the ink absorption accelerator should be selected by varying the composition according to the application object such as writing and stamping, but the preferred composition ratio is 10-20 parts by weight. When the composition ratio of the ink absorption accelerator is 10 parts by weight or less, absorption on the absorbing surface is slow, and the ink drying speed is slowed, making continuous writing and stamping difficult. On the contrary, when the composition ratio of the ink absorption accelerator is 20 parts by weight or more, the ink absorption speed to the absorption surface becomes very fast, so that the ink staining occurs on the back side of the absorption surface, and the ink transition occurs to the back side, making the ink use impossible.

As a dye used in the ink production of the present invention, it is preferable to use the black dye in the group consisting of carbon black, udai black, ivory black, direct black, and sirius supra brown, and in the case of blue dye, phthalic acid Cyanine Blue, Navy Blue, Navy Blue, Navy Blue, Cobalt Blue, Soluble Blue, Brilliant Blue, Acid Bio 6, Methylene Blue, Victoria Blue are recommended for use. It is preferable to select and use from the group which is Ga, silver, podium, cadmium red, antimony red, and scarlet.

The composition of the dye used should be selected differently depending on the required color, but the composition of 10-20 parts by weight is most preferred. When the amount of dye used is less than 10 parts by weight, the ink concentration is lowered, so that the color is blurred after writing, and the reading becomes difficult.

Dextrin is suitable as the dye binder used to impart the preservation of the ink. In particular, it is most preferable to select from the group consisting of amylodextrin, erythrodextrin, acrodextrin, malodextrin. The composition ratio of the dye binder is most preferably 3-7 parts by weight. When the amount of the dye binder is 3 parts by weight or less, dextrin becomes impossible to bind with the dye, which makes it difficult to impart invariability of the dye, and when the amount of the dye binder exceeds 7 parts by weight, the optimum amount of the dye binder is exceeded, and dextrin remains an impurity ink. It will adversely affect the physical properties.

Distilled water used in the present invention is preferably selected from distilled water distilled by a distilled water maker or pure water fine-filtered by reverse osmosis or membrane method. If distilled water or pure water is not used, the ink composition may be rotted and odors may be difficult to use.

The composition of the distilled water used is preferably 30-50 parts by weight. If the amount of distilled water is 30 parts by weight or less, the solution used in place of distilled water is replaced by a solvent, and eventually, the environmental friendliness is lost. At 50 parts by weight or more, distilled water lowers the absorption power of the absorbing surface, thereby slowing the drying speed of the ink. In addition, the water resistance is also reduced, making it impossible to use.

As the water-soluble binder used to impart the preservation of the ink, water-soluble natural and synthetic resins are used. The water-soluble binder is preferably selected from the group consisting of shellac resin, water-soluble acrylic resin, water-soluble urethane resin, water-soluble epoxy resin and modified resin thereof. The amount of the water-soluble binder used varies depending on the adhesive strength of the resin to be used, but the amount of the water-soluble binder is preferably 3-7 parts by weight. When the amount of the water-soluble binder is 3 parts by weight or less, the adhesive strength with the dye is lowered to obtain ink retention. When the amount of the water-soluble binder is 7 parts by weight or more, the adhesive strength with the dye becomes strong, but the ink adhesion becomes high, which makes the use of the ink uncomfortable.

It is preferable to select and use a combination of phenol, salicylic acid and tannic acid as the anti-corrosive agent used for anti-corruption during the use of the water-soluble ink for recording preservation. The amount of anti-corruption agent is preferably added to 3-8 parts by weight. If the anti-corrosive agent is added in 3 parts by weight or less, the anti-corruption effect cannot be exerted, and the rot phenomenon occurs when preserving the ink, and when it is added in an amount of 8 parts by weight or more, the anti-corrosive effect is the same. Ink quality is reduced.

It is preferable to use a combination of benzoic acid and cellulose ester as a fiber binding aid used to dye the dye component in the ink composition into the fiber of the paper absorbing surface, which is a transcript, and to be colored with a strong preservative ink by the action of basic acid. . It is preferable to use 5-15 weight part of addition amounts of a cellulose bond aid. If the fiber binding aid is used in an amount of 5 parts by weight or less, the binding force into the fiber is lowered, and thus the preservation of the ink is lowered. Since it spreads over the absorbing surface, ink bleeding occurs, which makes it impossible to use ink.

In order to improve the handwriting of the water-soluble ink for recording retention, viscosity control of the ink composition is required, and alcohols are used as the viscosity control agent used herein. As the alcohols to be used, those selected from the group of relatively harmless alcohols such as ethyl alcohol, methyl alcohol and isopropyl alcohol are preferably used. If the viscosity modifier is used in 3 parts by weight or less, the viscosity of the ink composition is high, which is inconvenient to use, and the quality of the product is deteriorated. This makes ink use impossible.

Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1

The stamp ink composition of the water-soluble ink for recording preservation was prepared as follows, and the mixing ratio of the ink composition is shown in Table 1.

First, 15 parts by weight of propylene glycol was charged into a 2,000 ml three-necked glass flask equipped with a stirrer, and 18 parts by weight of dye and 5 parts by weight of dextrin were added to the contents kept at 100 ° C. for 80 minutes at 80 ° C. Use to disperse the contents. After filling 35 parts by weight of distilled water in a 3,000 ml three-necked glass flask equipped with a separate stirrer and heating it at 100 ° C., 2 parts by weight of tannic acid, 2 parts by weight of phenol, and 3 parts by weight of benzoate were added to dissolve and then cooled to room temperature. Cool slowly.

Thereafter, 5 parts by weight of the dispersion prepared by milling, 5 parts by weight of the water-soluble acrylic binder and 5 parts by weight of the cellulose ester are added, and gradually heated to 60 ° C. for 3 hours, followed by slow cooling at room temperature. As a final step, 10 parts by weight of isopropyl alcohol is added to the reaction product to adjust the viscosity of the ink composition, and then preparation is completed.

Composition and Compounding Ratio of Recordable Ink Composition Compounding ratio (part by weight) Stamp For writing Example 1 Example 2 Example 3 Example 4 Water Soluble Acrylic Binder 5 5 - - Water Soluble Urethane Binder - - 5 5 Propylene glycol 15 15 15 20 Cellulose esters 5 5 2 5 Benzoic acid 3 3 3 3 Tannin 2 2 3 2 Coal mountain 2 2 3 3 Dye 18 20 15 20 dextrin 5 2 5 5 Isopropyl Alcohol 12 5 11 7 Distilled water 35 43 40 32 system 102 102 102 102

Example 2

The stamp ink composition of the recording preservation ink was prepared as follows, and the mixing ratio of the ink composition is shown in Table 1 above.

First, a ball mill or sand mill was charged by adding 20 parts by weight of dye and 2 parts by weight of dextrin to the contents of a 2,000 ml three-necked glass flask equipped with a stirrer, filled with 15 parts by weight of propylene glycol and cooled to 60 ° C. at 100 ° C. for 80 minutes. Use to disperse the contents. After filling 43 parts by weight of distilled water in a 3,000 ml three-necked glass flask equipped with a separate stirrer and heating it to 100 ° C., 2 parts by weight of tannic acid, 2 parts by weight of phenol and 3 parts by weight of benzoic acid were added to dissolve and then cooled to room temperature. Cool slowly.

Thereafter, 5 parts by weight of the dispersion prepared by milling, 5 parts by weight of a water-soluble acrylic binder and 5 parts by weight of cellulose ester were added thereto, and gradually heated to 60 ° C. for 3 hours, followed by slow cooling at room temperature. In the final step, 3 parts by weight of isopropyl alcohol is added to the reaction product to adjust the viscosity of the ink composition, and then the preparation is completed.

Example 3

The writing ink composition of the recording preservation ink was prepared as follows, and the mixing ratio of the ink composition is shown in Table 1 above.

First, a ball mill or sand mill was charged by adding 15 parts by weight of propylene glycol to a 2,000 ml three-necked glass flask equipped with a stirrer and adding 10 parts by weight of dye and 5 parts by weight of dextrin to the contents kept at 60 ° C. for 80 minutes at 100 ° C. Use to disperse the contents. Fill a 3,000 ml three-necked glass flask equipped with a separate stirrer with 40 parts by weight of distilled water and heat it to 100 ° C. Then, dissolve by adding 3 parts by weight of tannic acid, 3 parts by weight of phenol, and 3 parts by weight of benzoic acid, respectively. Cool slowly until.

Thereafter, 5 parts by weight of the dispersion prepared by milling, 5 parts by weight of a water-soluble urethane binder and 2 parts by weight of cellulose ester were added thereto, and gradually heated to 60 ° C. for 3 hours, followed by slow cooling at room temperature. As a final step, 10 parts by weight of isopropyl alcohol is added to the reactants to adjust the viscosity of the ink composition, and then preparation is completed.

Example 4

The writing ink composition of the recording preservation ink was prepared as follows, and the mixing ratio of the ink composition is shown in Table 1 above.

First, 20 parts by weight of propylene glycol was charged into a 2,000 ml three-necked glass flask equipped with a stirrer, and 20 parts by weight of dye and 5 parts by weight of dextrin were added to the contents kept at 60 ° C. for 80 minutes at 100 ° C. Use to disperse the contents. After filling 32 parts by weight of distilled water in a 3,000 ml three-necked glass flask equipped with a separate stirrer and heating it to 100 ° C, 2 parts by weight of tannic acid, 3 parts by weight of phenol, and 3 parts by weight of benzoate were added and dissolved, followed by room temperature. Cool slowly until.

Thereafter, 5 parts by weight of the dispersion prepared by milling, 5 parts by weight of a water-soluble urethane binder and 5 parts by weight of cellulose ester were added thereto, and gradually heated to 60 ° C. for 3 hours, followed by slow cooling at room temperature. In the final step, 5 parts by weight of isopropyl alcohol is added to the reactants to adjust the viscosity of the ink composition, and then the preparation is completed.

Test Example

The characteristic test of the water-retaining ink for recording and storage prepared in Examples 1 to 4 was evaluated based on the preservation writing ink (inner) and preservation stamp ink (inner) of the standard specification of preservation office supplies. The evaluation results are shown in Table 2.

The specific characteristic test evaluation method is as follows.

(1) Specimen manufacturing method (writing, stamping)

1 g of ink was collected on a glass plate, uniformly embedded in a rubber roller (40 mm in diameter, 900 mm in length), and then 3-4 sheets of test paper were stacked on top of each other, and 180 kg of square paper KS M 7108 A1 having 5 cm side. Reciprocate the roller once over the lead. The ink on a glass plate is affixed to a roller every one time of this operation | movement, and reciprocally transfers a total of 10 times 5 times in each crosswise direction, and consumes 1 g of ink. After this is done, it is allowed to stand for 30 minutes at room temperature before use as a specimen.

(2) Smear resistance test method (for writing and stamping)

Using a writing instrument, measure the line butterfly of the test piece which was written about 20 mm thick on the test paper with a measuring microscope after writing. After leaving for 48 hours in a room of 30 ± 5 ℃, measure the line butterfly again. Examine the increase rate (%).

(3) Hydrogen ion concentration index (pH) test method (for writing)

The hydrogen ion concentration of the aqueous ink sample is measured directly without pretreatment using a pH meter.

(4) Hydrogen ion concentration index (pH) test method (for stamps)

100 times of water (weight ratio) is added, the ink sample is heated for 10 minutes, cooled to room temperature, and separated by filter paper, and the filtrate is measured with a pH meter.

(5) Light resistance test method (for writing and stamping)

Using the tester specified in KS K 0700 or a similar fading tester, the specimen is irradiated for 48 hours under constant conditions (temperature 65 ℃, relative humidity: 50%) to investigate the fading state of the handwriting.

(6) Heat resistance test method (for writing and stamping)

Put the specimen uniformly coated on paper with a writing instrument in an incubator at 80 ° C and take it out every 25 and 50 hours to examine the condition of the handwriting.

(7) Water resistance test method (for writing and stamping)

The specimen is immersed in distilled water for 24 hours at room temperature and then dried to examine the state of the handwriting.

(8) Oil resistance test method (for writing and stamping)

Drop a drop of castor oil on the specimen, dropping it in moderation for three days, and examine the condition of the writing line.

(9) Alcohol resistance test method (for writing and stamping)

After leaving the specimen at room temperature for 1 hour, the specimen was immersed in 95% alcohol solution for 10 minutes and dried to examine the comparable state.

(10) Acid resistance test method (for writing and stamping)

The specimen is left to stand at room temperature for 1 hour, immersed in 10% hydrochloric acid solution for 24 hours, washed with distilled water for 10 minutes, dried and examined for comparable state.

(11) Alkali resistance test method (for writing and stamping)

The specimens were left at room temperature for 1 hour, immersed in 10% ammonia solution for 24 hours, washed with distilled water for 10 minutes and dried to investigate the comparable state.

(12) Test method for bleach resistance (for writing and stamp)

After leaving the specimen at room temperature for 1 hour, the specimen was immersed in a saturated solution of sodium hypochlorite (NaClO) for 5 minutes, and then dried to examine a comparable state.

Example 1 shows an example of a preferable composition ratio of the water-soluble ink for recording and storage for the staff to prepare an ink composition, and the evaluation results of the characteristics are shown in Table 2.

As can be seen from Table 2, the recording composition for preservation ink composition prepared in the compounding ratio of Example 1 shows excellent results for the recording preservation of ink such as light resistance, heat resistance, water resistance, oil resistance, alcohol resistance, acid resistance, alkali resistance and bleach resistance. As a result, it can be seen that discoloration or fading does not occur after writing even in actual application.

In Example 2, as the amount of distilled water was increased, 43 parts by weight of distilled water was increased for physical property comparison, and 3 parts by weight of isopropyl alcohol was reduced to control the viscosity of the final ink composition. In addition, in order to know the effect of the dye binder, the addition amount of dextrin was reduced to 3 parts by weight, and the other components were prepared in the same composition as in Example 1, the ink composition was prepared, and the results of the characterization are shown in Table 2. As can be seen from the results of Example 2, it can be seen that the water resistance and the heat resistance decrease as the amount of distilled water increases. In addition, it can be seen that the light resistance is decreased by reducing the amount of the dye binder dextrin.

Example 3 showed one example of the preferable composition ratio in the composition of the writing-recording recording ink, and the characteristics evaluation results are shown in Table 2. As can be seen from the results of Example 3, it can be seen that the ink composition prepared with the exemplified composition is excellent in the recording and storage properties of the ink such as light resistance, heat resistance, water resistance, oil resistance, alcohol resistance, acid resistance, alkali resistance and bleach resistance.

In Example 4, the amount of distilled water was reduced by 32 parts by weight, the amount of dye was added by 20 parts by weight, and the viscosity of the final ink composition was adjusted in order to compare the molarity of the water-soluble ink composition for writing and recording recording as the amount of distilled water decreased. In order to reduce the addition amount of isopropyl alcohol by 5 parts by weight to prepare an ink composition, the results of the characterization are shown in Table 2.

As can be seen from the results of Example 4, the recording retention of the ink with the addition amount of distilled water was the same as that of Example 3. On the other hand, the writing feeling, which is the largest item in terms of the actual use of the writing ink, was slightly lower in terms of handwriting because the results of Example 4 were superior to those of Example 3.

Evaluation result of preservation of water-soluble ink composition for record keeping Category Stamp For writing Remarks Example 1 Example 2 Example 3 Example 4 pH 7.3 7.2 7.8 7.9 7.0 or higher Light resistance 4-5 3-4 4-5 4-5 Be at least level 4 Heat resistance 25 hours ◎ ○ ◎ ◎ No bleeding and color change 50 hours ◎ ○ ◎ ◎ ″ Water resistance ◎ ○ ◎ ◎ ″ Oil resistance ◎ ◎ ◎ ◎ ″ Alcohol resistance ◎ ◎ ◎ ◎ ″ Acid resistance ◎ ◎ ◎ ◎ ″ Alkali resistance ◎ ◎ ◎ ◎ ″ Bleach resistance ◎ ◎ ◎ ◎ ″ Handwriting ◎ ○ ◎ ○ Good writing feeling

(Legend: ◎ very good ○ excellent △ normal × poor)

As described above, the novel water soluble ink composition for recording preservation according to the present invention is excellent in light resistance, heat resistance, water resistance, oil resistance, alcohol resistance, acid resistance, alkali resistance, bleach resistance, and the like and requires long-term recording retention as an important government record document. In addition to the intended use, such as securities can be applied to the anti-counterfeiting by the discoloration or fading of the ink.

Claims (2)

30-50 parts by weight of distilled water; 10-30 parts by weight of an ink absorption accelerator selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and glycerin; 3-7 parts by weight of a dye binder selected from the group consisting of amylodextrin, erythrodextrin, acrodextrin and malodextrin; 3-15 parts by weight of a viscosity modifier selected from the group consisting of ethyl alcohol, methyl alcohol and isopropyl alcohol; 3-8 parts by weight of at least one anti-corruption agent selected from the group consisting of phenol, salicylic acid and tannic acid; 3-7 parts by weight of a water-soluble binder selected from the group consisting of shellac, water-soluble acrylic resin, water-soluble urethane resin, water-soluble epoxy resin and modified resin thereof; An ink composition for recording preservation, comprising 5-15 parts by weight of a cellulose bond aid comprising cellulose ester and benzoic acid and 10-20 parts by weight of a dye. 1) heating 10-30 parts by weight of an alcohol selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol to 50 ° C. or more; 2) dispersing 10-20 parts by weight of the dye and 3-7 parts by weight of dextrin selected from the group consisting of amylodextrin, erythrodextrin, acrodextrin and malodextrin to the alcohol; 3) increasing the temperature of 30-50 parts by weight or more at 60 ° C. apart from steps 1) and 2); 4) adding 3-8 parts by weight of at least one acid selected from the group consisting of phenol, salicylic acid and tannic acid to the distilled water of step 3) to dissolve and slowly cool to room temperature; 5) mixing the dispersion prepared in step 2) and the solution prepared in step 4); 6) 3-7 parts by weight of the resin selected from the group consisting of shellac, water-soluble acrylic resin, water-soluble urethane resin, water-soluble epoxy resin and modified resin thereof and 5-15 parts by weight of cellulose ester are added to the mixture prepared in step 5). To 50 ° C. or higher; And 7) A method of preparing an ink composition for recording preservation by cooling the reaction product of step 6) to room temperature and adding 3-15 parts by weight of alcohol selected from the group consisting of ethyl alcohol, methyl alcohol and isopropyl alcohol.