JPS60238375A - Aqueous ink composition for ball-point pen - Google Patents

Abstract

PURPOSE:The titled aqueous ink composition providing ink with sufficient lubricating properties, improving excellently writing performance of ball-point pen, writing at high speed, preventing scratchy lines and skipping phenomena, comprising a dithiophosphate, etc. as essential components. CONSTITUTION:The desired component obtained by blending essential components of (A) a dithiophosphate (e.g., ammonium diethyl dithiophosphate, etc.) shown by the formula (R is H, lower alkyl, or alicyclic hydrocarbon; X is alkali metal, alkaline earth metal atom, ammonium, N-substituted ammonium or piperidinium), (B) a colorant, a lubricant (e.g., metallic salt of naphthenic acid, etc.), surface active agent, etc. Most preferably an amount of the component A is 0.1-5wt% in ink and an amount of the component B is 2-15wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION The present invention relates to a water-based ink for ballpoint pens. For details,
It reduces wear on the ball and part of the ball holder without causing handwriting to smear or inability to write due to ink dropback when the product is left upright (with the tip facing upward). It smooths out the ink flow, extends the effective writing distance, and also improves the line skipping phenomenon during high-speed writing (because the ball does not rotate smoothly, the ink supply is interrupted, and as a result, the writing line This invention relates to a water-based ink for ballpoint pens that prevents the phenomenon of discontinuity of

Water-based ink has extremely low lubricity compared to oil-based ink, so when applied to a ballpoint pen, the ball does not rotate smoothly, especially during high-speed writing.

It has drawbacks such as line skipping, the rotation of the ball becoming irregular due to abrasion of a part of the ball holder, and furthermore, the ink becoming impossible to write on before it is fully consumed. Ta.

Various proposals have been disclosed in the past in an attempt to solve these drawbacks. For example, in JP-A-52-8880, water-soluble silicone resin is used, and in JP-A-54-8880,
JP-A-81817 describes ink compositions each containing a water-soluble cutting oil. However, both of them significantly reduce the surface tension of the ink9.
Inability to write due to bleeding on paper, ink scattering due to falling, or ink dropback when left upright (leaving with tip facing upward) (swallowing phenomenon)
It had the disadvantage of causing problems such as

Structure of the Invention The present invention does not cause the various defects described above by incorporating a dithiophosphate.

It provides sufficient lubricity to the ink and significantly improves the writing performance of ballpoint pens. The dithiophosphate used in the present invention is represented by the following general formula.

General formula % Formula % Here, R represents an H atom, a lower alkyl group or an alicyclic hydrocarbon group, and X represents an alkali metal atom, an alkaline earth metal atom, ammonium, N-substituted ammonium or piperidium, respectively.

Specifically, lithium, sodium, potassium, calcium, barium, ammonium, and monoalkylammonium of dithiophosphoric acid, dimethyldithiophosphoric acid, diethyldithiophosphoric acid, dipropyldithiophosphoric acid, and dicyclohexyldithiophosphoric acid.

dialkylammonium, trialkylammonium,
It is a salt of N-alkanolamine, piperidine, etc.,
The effective amount of these compounds in the ink is 0.
．． If the blending amount is less than 0.05% by weight, the lubricating effect will be poor, and if it exceeds 8% by weight, the viscosity of the ink will increase, and the ink flow in the ink guiding section will be deteriorated.
Ink followability is inhibited. It can be used in an amount of 0.05 to 8% by weight, but it is more preferably added in an amount of 0.1 to 5% by weight.

Furthermore, in addition to these dithiophosphates, conventionally known lubricants 9 such as naphthenic acid metal salts, dithiocarba Enates, or phosphoric acid monoesters or diesters of polyoxyethylene alkyl ethers or alkylaryl ethers and their By using a phosphate ester surfactant selected from salts, the writing performance can be further improved.

The colorant used in the aqueous ink of the present invention is a dye or pigment that is dissolved or dispersed in an aqueous medium, and examples of the dye include eosin (C9I).

45880), acidphloxin (J 1..454)
10), erythrosine ((3,1,45480), tartrazine CC, 1,19140), sunset yellow FOF (J 1.15985).

Acid Rhodamine (0,1,45100), Acid Violet 6B (0,1,42640), Brilliant Blue FCF (C91,42090), Nigrosine N
Acidic dyes such as B (C1I, 50420), Direct Fast Yellow GC (0,1,29000), Violet B B (C!.

1.27905), Direct Sky Blue 5B<q,
i, 24400), Black G (C, j185255)
or rhodamine B (C, 1,451
70), Rhodamine 6GDN (C, I, 45160),
Examples include basic dyes such as methyl violet (C, 1, 42585) and Victoria Blue BOH (0, I, 42595), and pigments include carbon black, azo, anthraquinone, condensed polyazo, thioinsico, and metals. Examples include f1M salt-based, phthalocyanine-based, perinone/perylene-based, dioxane-based, and quinacridone-based organic pigments. These colorants are used in the ink in an amount of 1 to 25% by weight, preferably 2 to 15% by weight.

Ethylene glycol and diethylene glycol are also used for the purpose of suppressing ink drying at the pen tip, imparting water resistance to handwriting, or as a solubilizing agent for the dye.

Propylene glycol, butylene glycol, thiodiethylene glycol, glycerin, ethylene glycol monomethyl ether, polyethylene glycol (molecular weight 2
00 to 1000), N-methyl-2-pyrrolidone, 2
- Using pyrrolidone, triethanolamine, etc., improving the fluidity of the ink, or as a dispersant for the pigment,
Various surfactants, polyvinyl pyrrolidone, as an agent for preventing handwriting from bleeding and improving water resistance, or as a protective colloid for the pigments.
Polyvinyl alcohol, water-soluble acrylic resin, arapia gum. Water-soluble resins such as casein, sugars such as glucose and sucrose to impart appropriate viscosity to the ink, and preservatives such as phenol, sodium tehydroacetate and sodium benzoate may be used.

Next, specific examples of the water-based ink of the present invention will be explained. The parts in the following formulations indicate parts by weight.

Example 1 Ink composition Water Black 100-L (C, 1,85255) 80.0 parts Ethylene glycol 1000 parts Glycerin 10.0 parts Sucrose 5.0 parts Nonionic surfactant (polyoxyethylene phenol ether) 0.2 Diisopropyldithiophosphate diethylammonium salt
0.5 parts Phenol 0.5 parts Water 43.8 parts The above components were mixed and dissolved with stirring while heating to about 70°C to obtain a black ink.

Example 2 Ink composition Victoria Blue BOH (C11,42595) 2.
5 parts Methyl violet (C, 1,42585) 0.8 parts Diethylene glycol 10.0 parts Polymer glycol monomethyl ether 3.0 parts 1.3 Butylene gelicol 8.0 parts Polyvinyl alcohol 1.0 parts Ionic surfactant (polyoxyethylene oleyl ether) 0.8 parts Dicyclohexyl dithiophosphoric acid monoethanolamine salt 1.0 parts Sodium benzoate 0.5 parts Water 77.9 parts The above components were mixed and heated at about 60°C. The mixture was stirred and dissolved while heating to obtain a blue ink.

Example 3 Ink composition Acid Phloxin (0,1,45410) 1.5 parts Eosin GH (C01,45880) 3.0 parts Sunset Yellow FOF (C!, I, 15985)
0.5 parts polyethylene glycol (molecular weight approximately 200) to, o
parts Propylene glycol 10.0 parts Glucose 3.0 parts Cobalt naphthenate 0.1 parts Ammonium diethyldithiophosphate 1.0 parts Sodium tehydroacetate 1.0 parts Water 69.9 parts The above ingredients were mixed and heated to about 70°C. The mixture was stirred and dissolved while heating to obtain red ink.

Example 4 Ink composition Brilliant Blue FC! F 2.0 parts Acid Violet 5B 2.0 parts Set Yellow FCF 2.0 parts Triethanolamine 3.0 parts Diethylene glycol 15.0 parts Polyvinylpyrrolidone (K-80) 1.0 parts Potassium diethyldithiocarbamate 0 .5 parts Lithium dimethyldithiophosphate 1.5 parts Phenol 0.4 parts Water 62.6 parts The above components were mixed and dissolved with stirring while heating to about 70°C to obtain a black ink.

Example 5 Ink composition Victoria Blue Lake (blue pigment C9■.

44045) 7.0 parts Nonionic surfactant (polyoxyethylene lauryl ether) 2.0 parts Glycerin 10.0 parts Polymer gelicol 10.0 parts.

Polyvinylpyrrolidone (K-80)2. (1) Diethyldithiophosphoric acid monoethanolamine salt 0.5 parts Sodium debidroacetate 1.0 parts Water 67.5 parts The pigment was added to a medium in which the entire amount of surfactant was dissolved in 21 parts of water and kneaded to form a homogeneous mixture. A dispersion was prepared. Separately, a vehicle was prepared by dissolving the remaining components in the remaining amount of water, and the dispersion was added to the vehicle while stirring, and stirring was continued to obtain a homogeneous blue ink. In order to confirm the effects of the example ink, a zero-order comparative ink was prepared.

Comparative Example 1 A black ink was obtained in the same manner as in Example 1 except that the same amount of water was used to replace the diethylammonium diisoprobil dithiophosphate in the ink components.

Comparative Example 2 A blue ink was obtained in the same manner as in Example 2, except that dicyclohexyl dithiophosphate monoethanolamine salt in the ink components was replaced with the same amount of water.

Comparative Example 8 The same amount of silicone X-
22-851 (manufactured by Shin-Etsu Chemical, polyether-modified silicone resin) and in the same manner as above, a red ink was obtained.

Comparative Example 4 A black ink was obtained in the same manner by replacing potassium diethyldithiocarbamate and lithium dimethyldithiophosphate in the ink components of Example 4 with the same amount of Nijiroken CE-360 (manufactured by Yushiro Chemical ■, water-soluble cutting oil). Ta.

The effects of the invention were obtained by a prescription that exceeded the effects of the invention. Examples 1 to 5 and Comparative Example 1
A predetermined amount of the ink No. 4 was filled into a ballpoint pen of the type in which a metal tip equipped with a cemented carbide ball with a diameter of 0.7fl and an ink storage body in the shaft were connected by a fiber bundle processed core. Outline of the test method (1) Effective writing distance and effective ink consumption rate Writing speed 4 m
The sample ballpoint pen was used to write on a rotating circular writing tester adjusted to a writing angle of 70 degrees, a writing load of 100 F, and a writing angle of 70 degrees. The effective writing distance was determined by setting the point at which the value became 60η/10om or less as the end point.

Further, the effective ink consumption rate is expressed by a linear equation.

×100 C) High-speed followability After writing with the sample ballpoint pen continuously for 800 m using the writing tester described above, an X-Y plotter (manufactured by Shinki Iwasaki, 5
R-6602), 280 straight lines with a length of 85.71 were written at a writing speed of 203/sec, and the ink followability in high-speed writing (presence or absence of line skipping) and the state of the written lines (bleeding, shading, We investigated the presence or absence of

] 3) Swallowing test After assembling 50 ballpoint pens for each sample ink and confirming that they can write normally, cap them and hold them in an upright position (tip facing upward) for 20 days, then conduct a writing test. Table 1 examining the number of writing defects (swallowing) due to ink dropback As seen in Table 1 above, the ink containing the dithiophosphate compound of the present invention does not cause blurring or swallowing defects in handwriting. This significantly increases the effective writing distance and the amount of ink effectively consumed by water-based ballpoint pens.
It also prevents the line skipping phenomenon during high-speed writing. Furthermore, by using a lubricant such as a metal naphthenate or a dithiocarbamate, the writing performance can be further improved.

Claims (1)

[Claims] A dithiophosphate 1 represented by the following general formula as an essential component:
A water-based ink composition for a ballpoint pen containing a colorant and water. General formula % formula % Here, 几 represents an atom, a lower alkyl group or an alicyclic hydrocarbon group, and X represents an alkali metal atom, an alkali metal atom, ammonium, N-substituted ammonium or piperidinium, respectively.