KR19990085465A - Ink composition for aqueous ballpoint pen - Google Patents

Abstract

The present invention relates to an ink composition for an aqueous ballpoint pen, particularly a composition of medium viscosity ink having a viscosity of about 1,000 to 5,000 m Pa.s (cp). In the addition of an appropriate amount of a polymer substance as a thixotropic agent, the polymer substance is poly-N-vinylacetamide, and the amount of the polymer substance is 0.1 to 5.0% by weight based on the total amount. Type Viscometer, ROTOR N0.3 At 6 rpm, 25 ℃, it becomes 1,000 ~ 5,000mPa.s (cp), so that ink does not settle during long-term storage and seamless writing when writing You can get ink as much as possible.

Description

Ink composition for aqueous ballpoint pen

TECHNICAL FIELD The present invention relates to a composition of an ink used in an aqueous ballpoint pen, in particular, a medium viscosity ink whose viscosity is usually about 1,000 to 5,000 m Pa · s (cp).

This conventional ink is used in conjunction with a high viscosity backflow preventer in a transparent tube of a ballpoint pen and when the ink is reduced in the tube due to its use, the reduced portion of the tube should be kept clean and in some cases the ink therein. Not only is the appearance unclean due to the crack phenomenon, but the writing line concentration is not constant at the time of writing, and in severe cases, the tip of the ink is blocked to stop the writing during writing.

As a result, the present inventors made a lot of efforts to determine the cause of the conventional water-based pen ink, xanthan gum, which is generally a polymer material, is generally used to provide water-dispersible thixotropy. (See Patent Publication No. 2626 / Publication No. 92-623) This is caused by lack of safety with colorant, especially when fluorescent pigment is used as colorant. It was found that due to the swelling dispersion instability of the gum, a small amount of water was separated and condensed due to precipitation of the contents.

In order to solve the conventional problems as described above, the solution of the interaction between ink compositions providing the cause of the problem, that is, the composition of the xanthan gum and the colorant, which is a thixotropic agent, must be solved.

To this end, while examining various polymer materials, poly-N-vinylacetamide (P0LY-N-VINYL ACETAMIDE) is used as a thixotropic agent and the ink composition has a viscosity of 1,000 to 5,000 mPas (cp). It is an object of the present invention to provide an ink composition that can solve all of the above problems, such as not being precipitated or aggregated, and capable of writing seamlessly during writing.

1 is a cross-sectional view of a writing instrument showing an example of an aqueous ballpoint pen using the ink composition of the present invention

Explanation of symbols on the main parts of the drawings

1. Ball pen 2. Resin tube 3. Ink 4. Backflow preventer

5. Ballpoint pen tip 6. Holder 7. Ball

The present invention was found to show excellent results as a result of performing long-term preservation promotion test at 50 ° C. for 12 weeks using poly-N-vinylacetamide (POLY-N-VINYL ACETAMIDE) as a thixotropic agent. Further, addition of a small amount of ordinary xanthan gum to 0.1% by weight or less of the poly-N-vinylacetamide polymer material of the present invention did not have any negative effect on the effect of the present invention.

In addition, the ink of the present invention is a B-type viscometer Rhoda (ROTOR). When measuring the viscosity at 20 ℃, the viscosity was 1,000 to 5,000 mPa.s (cp) at 6 rpm, which is sufficient for the purpose of preventing sedimentation during long-term storage. .

These results indicate that in xanthan gum, the molecular weight is about 2 million to 15 million macromolecules, so it is difficult to swell sufficiently in water, and this material is a macromolecule material cultivated by microorganisms. It is very difficult to represent.

Therefore, in the present invention, the structure of the polymer is the same as the chemical formula below, and has an acetamide group (ACETAMIDbase) in the structure, so that it can thicken well in a polar solvent, that is, water, and control the molecular weight by monomer (M0N0MER) polymerization. This is possible and no dispersion of viscosity occurs

In the present invention, the colorant may be a pigment or a dye, and in particular, an acid dye or a direct dye may be used in the dye, and the amount may be 1 to 50% by weight.

In the ink of the present invention, 10 to 70% by weight of water is used, and a wetting agent of polyalcohol is used in order to suppress evaporation of foreign matters. OLY (PR0PYLENEGLYCOL), Glycerine, Urea, U, BUTYLENE GLYCOL, 1,4-Butanediol, 2,3 Butylenediol, Neopentylglycool NEOPENTHYLGLYC0L), HEXYLENE GLYCOL, N-methyl-2-pyrrolidone, thiodiglycool (THI0DIGLYC0L), 2-pyrrolidone (PYRR0LID0NE), trimethylolpropane (TRIMETHYL0LPR0PANE), sorbitol , Diglycerin (DIGYLCERIN), dimethylformamide (DIMETHYLFORMAMIDE) and the like, the amount is 5 to 50% by weight based on the total amount.

In the present invention, the ink of the present invention is completed by adding a lubricant, an antiseptic, an antirust agent, an acidity regulator, and the like, which are usually used in the ink.

And the ink 3 of the present invention is stored in the transparent synthetic resin tube 2 of the aqueous ballpoint pen 1, and the high viscosity backflow prevention material 4 moving together with the consumption of the ink 3 is stored at the rear end thereof. One side of the resin tube 2 is equipped with a ballpoint pen tip 5 and a connecting holder 6 so that the ink 3 passes through the holder 6 in the resin tube 2 and the ball 7 at the tip 5 of the tip 5. It is a structure that can be guided to writing.

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

Example 1

POLY-N-VINYL ACETAMIDE 1.0 wt%

(Brand name GX-205 of SH0WA DENK0 KK)

37.2 wt% of ion-exchanged water

GLYCERIN 20.0 wt%

PROXEL XL-2 0.3 wt%

FRYSURF AL 0.5 wt%

BENZOTRIAZOL 1.0 wt%

Direct black 154 (15% solids solution) 40.0 wt%

This compound was dispersed and dissolved at 60 DEG C for 2 hours to obtain a black ink having a viscosity of 3,000 cps.

Example 2

POLY-N-VINTY ACETAMIDE 1.5 wt%

(Japan KK)

37.1 wt% of ion-exchanged water

GLYCERINE 20.0 wt%

PROXEL XL-2 0.3 wt%

FLUORAD FC-430 0.1 wt%

BENZOTRIAZOL 1.0 wt%

Direct black 154 (15% solids solution) 40.0 wt%

The compound was dispersed and dissolved for 2 hours at 60 DEG C to obtain a black ink having a viscosity of 3,500 cps.

Example 3

P0LY-N-VINTY ACETAMIDE 1.5% by weight

(Brand name GX-205 of SH0WA DENK0 KK)

36.7% by weight of ion-exchanged water

GLYCERINE 20.0 wt%

PROXEL XL-2 0.3 wt%

SC0AR0L # 900 0.5 wt%

BENZ0TRIAZ0L 1.0 wt%

LUMIKOL NKW-2105 (Japan Fluorescent Agent) 40.0 wt%

This compound was dispersed and dissolved for 2 hours at 60 ° C. to obtain a fluorescent yellow ink having a viscosity of 3,000 cps.

Example 4

POLY-N-VINTY ACETAMIDE 1.0 Weight%

(Brand name GX-205 of SHOWA DENKO KK)

XANTHAN GUM (大 日本 純 藥) 0.1 wt%

37.1 wt% of ion-exchanged water

GLYCERINE 20.0 wt%

PROXEL XL-2 0.3 wt%

FRYSURF AL 1.0 wt%

BENZOTRIAZOL 1.0 wt%

C.I Acid blue 90 (Solid 13% Solution) 40.0 wt%

This compound was dispersed and dissolved for 2 hours at 60 ° C to obtain a blue ink having a viscosity of 3,000 cps.

Comparative Example 1

XANTHAN GUM 0.4 wt%

(KELCO Corporation)

37.8% by weight of ion-exchanged water

GLYCERINE 20.0 wt%

PROXEL XL-2 0.3 wt%

FRYSURF AL 0.5 wt%

BENZOTRIAZOL 1.0 wt%

Direct black 154 (15% solids solution) 40.0 wt%

This compound was dispersed and dissolved for 2 hours at 60 ° C. to obtain a black ink having a viscosity of 3,200 cps.

Comparative Example 2

XANTHAN GUM 0.8 wt%

(大 日本 製藥 株)

37.8% by weight of ion-exchanged water

GLYCERINE 20.0 wt%

PROXEL XL-2 0.3 wt%

FLUORAD FC-430 0.1 wt%

BENZOTRIAZOL 1.0 wt%

Direct black 19 (Solid 15% solution) 40.0 wt%

This compound was dispersed and dissolved for 2 hours at 60 DEG C to obtain a black ink having a viscosity of 3,300 cps.

Comparative Example 3

XANTHAN GUM 0.4 wt%

(KELC0 company)

37.8% by weight of ion-exchanged water

GLYCERINE 20.0 wt%

PROXEL XL-2 0.3 wt%

SC0AR0L # 900 0.5 wt%

BENZOTRIAZOL 1.0 wt%

LUMIKOL NKW-2105 (Japan Fluorescent Agent) 40.0 wt%

This compound was dispersed and dissolved for 2 hours at 60 ° C. to obtain a fluorescent yellow ink having a viscosity of 3,000 cps.

Comparative Example 4

XANTHAN GUM (大 日本 純 藥) 0.8% by weight

37.4 wt% of ion-exchanged water

GLYCERINE 20.0 wt%

PROXEL XL-2 0.3 wt%

FRYSURF AL 0.5 wt%

BENZOTRIAZOL 1.0 wt%

C.I Acid blue 90 (Solid 13% Solution) 40.0 wt%

This compound was dispersed and dissolved for 2 hours at 60 ° C to obtain a blue ink having a viscosity of 3,000 cps.

Fill the 0.8-ml ink with MY-GEL PEN refills of Dong-A, which is on the market, and store 10 copies of each tip up and down for 12 weeks in a 50 ° C long-term preservation test. The results of testing the pencil writing, continuous writing, and refill appearance are summarized in Table 1 below.

Pencil Writing: ○-Smooth ink from the pencil

△-Ink is normally written within 3cm

Continuous handwriting: ○-Good writing line △-Breaking out

Refill Appearance: ○-Good appearance △-Some cracking phenomenon

×-The appearance of cracking is clearly visible (severe)

As shown in the results of Table 1 above, the ink of the example had no change in viscosity and was clearly different from the comparative example in the writing and continuous writing properties of the pencil, and particularly, the cracking phenomenon was not seen in the refill appearance, and thus showed excellent results.

(Note 1)

* Writable pencil: 12 weeks at 50 ° C for up to 12 copies of the tip of the sample kept in the top and open the cap to see if you can write smoothly and seamlessly when you start writing the spiral.

(Note 2)

* Continuous handwriting: At the end of 12 weeks at 50 ° C, open the cap of the sample for 10 copies up and down for 12 weeks, and then write 100m continuously with a writing load of 100g, a writing angle of 65 °, and a writing speed of 4.2m / min. See the break in the writing line while writing.

(Note 3)

* Appearance: Observe the external appearance of the specimens stored at each tip for 10 weeks at 50 ℃ for up to 12 weeks to visually check for cracking, clumping and separation of ink inside the refill.

The ink composition of the present invention uses poly-N-vinylacetamide as a thixotropic agent to ensure stability with the colorant, and in particular, when a fluorescent pigment is used as the colorant, the pigment as the colorant does not disperse, so that no aggregation of particles occurs. Even if it is stored for a long time, no settling of the ink composition occurs, and even if the ink is reduced due to the use of a writing instrument user, the transparent synthetic resin tube (2) of the reduced portion is intact, that is, there is no cracking of ink therein. In addition, the appearance is not only clean, but the concentration of the line of sight is constant during writing, so that writing can be performed without interruption, and there is no blocking of the ink of the tip.

Claims (2)

In a well-known method of adding an appropriate amount of a polymer substance as a thixotropic agent to an ink as a colorant, a polyhydric alcohol for preventing evaporation of water and water, the polymer substance as a thixotropic agent is poly-N-vinylacetamide, and the amount of the polymer is 0.1 to the total. To 5.0% by weight of the ink composition for an aqueous ballpoint pen. The aqueous ballpoint pen according to claim 1, wherein the ink has a viscosity of 1,000 to 5,000 mPa.s (cp) when the measurement conditions are set to a type B viscometer, a rho-da- (R0T0R) No. 3, 6 rpm, and 20 ° C. Ink composition.